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 /* Free Page Internal flags: for internal, non-pcp variants of free_pages(). */
82 typedef int __bitwise fpi_t
;
84 /* No special request */
85 #define FPI_NONE ((__force fpi_t)0)
88 * Skip free page reporting notification for the (possibly merged) page.
89 * This does not hinder free page reporting from grabbing the page,
90 * reporting it and marking it "reported" - it only skips notifying
91 * the free page reporting infrastructure about a newly freed page. For
92 * example, used when temporarily pulling a page from a freelist and
93 * putting it back unmodified.
95 #define FPI_SKIP_REPORT_NOTIFY ((__force fpi_t)BIT(0))
98 * Place the (possibly merged) page to the tail of the freelist. Will ignore
99 * page shuffling (relevant code - e.g., memory onlining - is expected to
100 * shuffle the whole zone).
102 * Note: No code should rely on this flag for correctness - it's purely
103 * to allow for optimizations when handing back either fresh pages
104 * (memory onlining) or untouched pages (page isolation, free page
107 #define FPI_TO_TAIL ((__force fpi_t)BIT(1))
109 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
110 static DEFINE_MUTEX(pcp_batch_high_lock
);
111 #define MIN_PERCPU_PAGELIST_FRACTION (8)
113 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
114 DEFINE_PER_CPU(int, numa_node
);
115 EXPORT_PER_CPU_SYMBOL(numa_node
);
118 DEFINE_STATIC_KEY_TRUE(vm_numa_stat_key
);
120 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
122 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
123 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
124 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
125 * defined in <linux/topology.h>.
127 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
128 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
131 /* work_structs for global per-cpu drains */
134 struct work_struct work
;
136 static DEFINE_MUTEX(pcpu_drain_mutex
);
137 static DEFINE_PER_CPU(struct pcpu_drain
, pcpu_drain
);
139 #ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
140 volatile unsigned long latent_entropy __latent_entropy
;
141 EXPORT_SYMBOL(latent_entropy
);
145 * Array of node states.
147 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
148 [N_POSSIBLE
] = NODE_MASK_ALL
,
149 [N_ONLINE
] = { { [0] = 1UL } },
151 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
152 #ifdef CONFIG_HIGHMEM
153 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
155 [N_MEMORY
] = { { [0] = 1UL } },
156 [N_CPU
] = { { [0] = 1UL } },
159 EXPORT_SYMBOL(node_states
);
161 atomic_long_t _totalram_pages __read_mostly
;
162 EXPORT_SYMBOL(_totalram_pages
);
163 unsigned long totalreserve_pages __read_mostly
;
164 unsigned long totalcma_pages __read_mostly
;
166 int percpu_pagelist_fraction
;
167 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
168 #ifdef CONFIG_INIT_ON_ALLOC_DEFAULT_ON
169 DEFINE_STATIC_KEY_TRUE(init_on_alloc
);
171 DEFINE_STATIC_KEY_FALSE(init_on_alloc
);
173 EXPORT_SYMBOL(init_on_alloc
);
175 #ifdef CONFIG_INIT_ON_FREE_DEFAULT_ON
176 DEFINE_STATIC_KEY_TRUE(init_on_free
);
178 DEFINE_STATIC_KEY_FALSE(init_on_free
);
180 EXPORT_SYMBOL(init_on_free
);
182 static int __init
early_init_on_alloc(char *buf
)
187 ret
= kstrtobool(buf
, &bool_result
);
190 if (bool_result
&& page_poisoning_enabled())
191 pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, will take precedence over init_on_alloc\n");
193 static_branch_enable(&init_on_alloc
);
195 static_branch_disable(&init_on_alloc
);
198 early_param("init_on_alloc", early_init_on_alloc
);
200 static int __init
early_init_on_free(char *buf
)
205 ret
= kstrtobool(buf
, &bool_result
);
208 if (bool_result
&& page_poisoning_enabled())
209 pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, will take precedence over init_on_free\n");
211 static_branch_enable(&init_on_free
);
213 static_branch_disable(&init_on_free
);
216 early_param("init_on_free", early_init_on_free
);
219 * A cached value of the page's pageblock's migratetype, used when the page is
220 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
221 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
222 * Also the migratetype set in the page does not necessarily match the pcplist
223 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
224 * other index - this ensures that it will be put on the correct CMA freelist.
226 static inline int get_pcppage_migratetype(struct page
*page
)
231 static inline void set_pcppage_migratetype(struct page
*page
, int migratetype
)
233 page
->index
= migratetype
;
236 #ifdef CONFIG_PM_SLEEP
238 * The following functions are used by the suspend/hibernate code to temporarily
239 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
240 * while devices are suspended. To avoid races with the suspend/hibernate code,
241 * they should always be called with system_transition_mutex held
242 * (gfp_allowed_mask also should only be modified with system_transition_mutex
243 * held, unless the suspend/hibernate code is guaranteed not to run in parallel
244 * with that modification).
247 static gfp_t saved_gfp_mask
;
249 void pm_restore_gfp_mask(void)
251 WARN_ON(!mutex_is_locked(&system_transition_mutex
));
252 if (saved_gfp_mask
) {
253 gfp_allowed_mask
= saved_gfp_mask
;
258 void pm_restrict_gfp_mask(void)
260 WARN_ON(!mutex_is_locked(&system_transition_mutex
));
261 WARN_ON(saved_gfp_mask
);
262 saved_gfp_mask
= gfp_allowed_mask
;
263 gfp_allowed_mask
&= ~(__GFP_IO
| __GFP_FS
);
266 bool pm_suspended_storage(void)
268 if ((gfp_allowed_mask
& (__GFP_IO
| __GFP_FS
)) == (__GFP_IO
| __GFP_FS
))
272 #endif /* CONFIG_PM_SLEEP */
274 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
275 unsigned int pageblock_order __read_mostly
;
278 static void __free_pages_ok(struct page
*page
, unsigned int order
,
282 * results with 256, 32 in the lowmem_reserve sysctl:
283 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
284 * 1G machine -> (16M dma, 784M normal, 224M high)
285 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
286 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
287 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
289 * TBD: should special case ZONE_DMA32 machines here - in those we normally
290 * don't need any ZONE_NORMAL reservation
292 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
] = {
293 #ifdef CONFIG_ZONE_DMA
296 #ifdef CONFIG_ZONE_DMA32
300 #ifdef CONFIG_HIGHMEM
306 static char * const zone_names
[MAX_NR_ZONES
] = {
307 #ifdef CONFIG_ZONE_DMA
310 #ifdef CONFIG_ZONE_DMA32
314 #ifdef CONFIG_HIGHMEM
318 #ifdef CONFIG_ZONE_DEVICE
323 const char * const migratetype_names
[MIGRATE_TYPES
] = {
331 #ifdef CONFIG_MEMORY_ISOLATION
336 compound_page_dtor
* const compound_page_dtors
[NR_COMPOUND_DTORS
] = {
337 [NULL_COMPOUND_DTOR
] = NULL
,
338 [COMPOUND_PAGE_DTOR
] = free_compound_page
,
339 #ifdef CONFIG_HUGETLB_PAGE
340 [HUGETLB_PAGE_DTOR
] = free_huge_page
,
342 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
343 [TRANSHUGE_PAGE_DTOR
] = free_transhuge_page
,
347 int min_free_kbytes
= 1024;
348 int user_min_free_kbytes
= -1;
349 #ifdef CONFIG_DISCONTIGMEM
351 * DiscontigMem defines memory ranges as separate pg_data_t even if the ranges
352 * are not on separate NUMA nodes. Functionally this works but with
353 * watermark_boost_factor, it can reclaim prematurely as the ranges can be
354 * quite small. By default, do not boost watermarks on discontigmem as in
355 * many cases very high-order allocations like THP are likely to be
356 * unsupported and the premature reclaim offsets the advantage of long-term
357 * fragmentation avoidance.
359 int watermark_boost_factor __read_mostly
;
361 int watermark_boost_factor __read_mostly
= 15000;
363 int watermark_scale_factor
= 10;
365 static unsigned long nr_kernel_pages __initdata
;
366 static unsigned long nr_all_pages __initdata
;
367 static unsigned long dma_reserve __initdata
;
369 static unsigned long arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
] __initdata
;
370 static unsigned long arch_zone_highest_possible_pfn
[MAX_NR_ZONES
] __initdata
;
371 static unsigned long required_kernelcore __initdata
;
372 static unsigned long required_kernelcore_percent __initdata
;
373 static unsigned long required_movablecore __initdata
;
374 static unsigned long required_movablecore_percent __initdata
;
375 static unsigned long zone_movable_pfn
[MAX_NUMNODES
] __initdata
;
376 static bool mirrored_kernelcore __meminitdata
;
378 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
380 EXPORT_SYMBOL(movable_zone
);
383 unsigned int nr_node_ids __read_mostly
= MAX_NUMNODES
;
384 unsigned int nr_online_nodes __read_mostly
= 1;
385 EXPORT_SYMBOL(nr_node_ids
);
386 EXPORT_SYMBOL(nr_online_nodes
);
389 int page_group_by_mobility_disabled __read_mostly
;
391 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
393 * During boot we initialize deferred pages on-demand, as needed, but once
394 * page_alloc_init_late() has finished, the deferred pages are all initialized,
395 * and we can permanently disable that path.
397 static DEFINE_STATIC_KEY_TRUE(deferred_pages
);
400 * Calling kasan_free_pages() only after deferred memory initialization
401 * has completed. Poisoning pages during deferred memory init will greatly
402 * lengthen the process and cause problem in large memory systems as the
403 * deferred pages initialization is done with interrupt disabled.
405 * Assuming that there will be no reference to those newly initialized
406 * pages before they are ever allocated, this should have no effect on
407 * KASAN memory tracking as the poison will be properly inserted at page
408 * allocation time. The only corner case is when pages are allocated by
409 * on-demand allocation and then freed again before the deferred pages
410 * initialization is done, but this is not likely to happen.
412 static inline void kasan_free_nondeferred_pages(struct page
*page
, int order
)
414 if (!static_branch_unlikely(&deferred_pages
))
415 kasan_free_pages(page
, order
);
418 /* Returns true if the struct page for the pfn is uninitialised */
419 static inline bool __meminit
early_page_uninitialised(unsigned long pfn
)
421 int nid
= early_pfn_to_nid(pfn
);
423 if (node_online(nid
) && pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
430 * Returns true when the remaining initialisation should be deferred until
431 * later in the boot cycle when it can be parallelised.
433 static bool __meminit
434 defer_init(int nid
, unsigned long pfn
, unsigned long end_pfn
)
436 static unsigned long prev_end_pfn
, nr_initialised
;
439 * prev_end_pfn static that contains the end of previous zone
440 * No need to protect because called very early in boot before smp_init.
442 if (prev_end_pfn
!= end_pfn
) {
443 prev_end_pfn
= end_pfn
;
447 /* Always populate low zones for address-constrained allocations */
448 if (end_pfn
< pgdat_end_pfn(NODE_DATA(nid
)))
452 * We start only with one section of pages, more pages are added as
453 * needed until the rest of deferred pages are initialized.
456 if ((nr_initialised
> PAGES_PER_SECTION
) &&
457 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
458 NODE_DATA(nid
)->first_deferred_pfn
= pfn
;
464 #define kasan_free_nondeferred_pages(p, o) kasan_free_pages(p, o)
466 static inline bool early_page_uninitialised(unsigned long pfn
)
471 static inline bool defer_init(int nid
, unsigned long pfn
, unsigned long end_pfn
)
477 /* Return a pointer to the bitmap storing bits affecting a block of pages */
478 static inline unsigned long *get_pageblock_bitmap(struct page
*page
,
481 #ifdef CONFIG_SPARSEMEM
482 return section_to_usemap(__pfn_to_section(pfn
));
484 return page_zone(page
)->pageblock_flags
;
485 #endif /* CONFIG_SPARSEMEM */
488 static inline int pfn_to_bitidx(struct page
*page
, unsigned long pfn
)
490 #ifdef CONFIG_SPARSEMEM
491 pfn
&= (PAGES_PER_SECTION
-1);
493 pfn
= pfn
- round_down(page_zone(page
)->zone_start_pfn
, pageblock_nr_pages
);
494 #endif /* CONFIG_SPARSEMEM */
495 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
499 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
500 * @page: The page within the block of interest
501 * @pfn: The target page frame number
502 * @mask: mask of bits that the caller is interested in
504 * Return: pageblock_bits flags
506 static __always_inline
507 unsigned long __get_pfnblock_flags_mask(struct page
*page
,
511 unsigned long *bitmap
;
512 unsigned long bitidx
, word_bitidx
;
515 bitmap
= get_pageblock_bitmap(page
, pfn
);
516 bitidx
= pfn_to_bitidx(page
, pfn
);
517 word_bitidx
= bitidx
/ BITS_PER_LONG
;
518 bitidx
&= (BITS_PER_LONG
-1);
520 word
= bitmap
[word_bitidx
];
521 return (word
>> bitidx
) & mask
;
524 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
527 return __get_pfnblock_flags_mask(page
, pfn
, mask
);
530 static __always_inline
int get_pfnblock_migratetype(struct page
*page
, unsigned long pfn
)
532 return __get_pfnblock_flags_mask(page
, pfn
, MIGRATETYPE_MASK
);
536 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
537 * @page: The page within the block of interest
538 * @flags: The flags to set
539 * @pfn: The target page frame number
540 * @mask: mask of bits that the caller is interested in
542 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
546 unsigned long *bitmap
;
547 unsigned long bitidx
, word_bitidx
;
548 unsigned long old_word
, word
;
550 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
551 BUILD_BUG_ON(MIGRATE_TYPES
> (1 << PB_migratetype_bits
));
553 bitmap
= get_pageblock_bitmap(page
, pfn
);
554 bitidx
= pfn_to_bitidx(page
, pfn
);
555 word_bitidx
= bitidx
/ BITS_PER_LONG
;
556 bitidx
&= (BITS_PER_LONG
-1);
558 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page
), pfn
), page
);
563 word
= READ_ONCE(bitmap
[word_bitidx
]);
565 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
566 if (word
== old_word
)
572 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
574 if (unlikely(page_group_by_mobility_disabled
&&
575 migratetype
< MIGRATE_PCPTYPES
))
576 migratetype
= MIGRATE_UNMOVABLE
;
578 set_pfnblock_flags_mask(page
, (unsigned long)migratetype
,
579 page_to_pfn(page
), MIGRATETYPE_MASK
);
582 #ifdef CONFIG_DEBUG_VM
583 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
587 unsigned long pfn
= page_to_pfn(page
);
588 unsigned long sp
, start_pfn
;
591 seq
= zone_span_seqbegin(zone
);
592 start_pfn
= zone
->zone_start_pfn
;
593 sp
= zone
->spanned_pages
;
594 if (!zone_spans_pfn(zone
, pfn
))
596 } while (zone_span_seqretry(zone
, seq
));
599 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
600 pfn
, zone_to_nid(zone
), zone
->name
,
601 start_pfn
, start_pfn
+ sp
);
606 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
608 if (!pfn_valid_within(page_to_pfn(page
)))
610 if (zone
!= page_zone(page
))
616 * Temporary debugging check for pages not lying within a given zone.
618 static int __maybe_unused
bad_range(struct zone
*zone
, struct page
*page
)
620 if (page_outside_zone_boundaries(zone
, page
))
622 if (!page_is_consistent(zone
, page
))
628 static inline int __maybe_unused
bad_range(struct zone
*zone
, struct page
*page
)
634 static void bad_page(struct page
*page
, const char *reason
)
636 static unsigned long resume
;
637 static unsigned long nr_shown
;
638 static unsigned long nr_unshown
;
641 * Allow a burst of 60 reports, then keep quiet for that minute;
642 * or allow a steady drip of one report per second.
644 if (nr_shown
== 60) {
645 if (time_before(jiffies
, resume
)) {
651 "BUG: Bad page state: %lu messages suppressed\n",
658 resume
= jiffies
+ 60 * HZ
;
660 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
661 current
->comm
, page_to_pfn(page
));
662 __dump_page(page
, reason
);
663 dump_page_owner(page
);
668 /* Leave bad fields for debug, except PageBuddy could make trouble */
669 page_mapcount_reset(page
); /* remove PageBuddy */
670 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
674 * Higher-order pages are called "compound pages". They are structured thusly:
676 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
678 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
679 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
681 * The first tail page's ->compound_dtor holds the offset in array of compound
682 * page destructors. See compound_page_dtors.
684 * The first tail page's ->compound_order holds the order of allocation.
685 * This usage means that zero-order pages may not be compound.
688 void free_compound_page(struct page
*page
)
690 mem_cgroup_uncharge(page
);
691 __free_pages_ok(page
, compound_order(page
), FPI_NONE
);
694 void prep_compound_page(struct page
*page
, unsigned int order
)
697 int nr_pages
= 1 << order
;
700 for (i
= 1; i
< nr_pages
; i
++) {
701 struct page
*p
= page
+ i
;
702 set_page_count(p
, 0);
703 p
->mapping
= TAIL_MAPPING
;
704 set_compound_head(p
, page
);
707 set_compound_page_dtor(page
, COMPOUND_PAGE_DTOR
);
708 set_compound_order(page
, order
);
709 atomic_set(compound_mapcount_ptr(page
), -1);
710 if (hpage_pincount_available(page
))
711 atomic_set(compound_pincount_ptr(page
), 0);
714 #ifdef CONFIG_DEBUG_PAGEALLOC
715 unsigned int _debug_guardpage_minorder
;
717 bool _debug_pagealloc_enabled_early __read_mostly
718 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT
);
719 EXPORT_SYMBOL(_debug_pagealloc_enabled_early
);
720 DEFINE_STATIC_KEY_FALSE(_debug_pagealloc_enabled
);
721 EXPORT_SYMBOL(_debug_pagealloc_enabled
);
723 DEFINE_STATIC_KEY_FALSE(_debug_guardpage_enabled
);
725 static int __init
early_debug_pagealloc(char *buf
)
727 return kstrtobool(buf
, &_debug_pagealloc_enabled_early
);
729 early_param("debug_pagealloc", early_debug_pagealloc
);
731 void init_debug_pagealloc(void)
733 if (!debug_pagealloc_enabled())
736 static_branch_enable(&_debug_pagealloc_enabled
);
738 if (!debug_guardpage_minorder())
741 static_branch_enable(&_debug_guardpage_enabled
);
744 static int __init
debug_guardpage_minorder_setup(char *buf
)
748 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
749 pr_err("Bad debug_guardpage_minorder value\n");
752 _debug_guardpage_minorder
= res
;
753 pr_info("Setting debug_guardpage_minorder to %lu\n", res
);
756 early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup
);
758 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
759 unsigned int order
, int migratetype
)
761 if (!debug_guardpage_enabled())
764 if (order
>= debug_guardpage_minorder())
767 __SetPageGuard(page
);
768 INIT_LIST_HEAD(&page
->lru
);
769 set_page_private(page
, order
);
770 /* Guard pages are not available for any usage */
771 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
776 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
777 unsigned int order
, int migratetype
)
779 if (!debug_guardpage_enabled())
782 __ClearPageGuard(page
);
784 set_page_private(page
, 0);
785 if (!is_migrate_isolate(migratetype
))
786 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
789 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
790 unsigned int order
, int migratetype
) { return false; }
791 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
792 unsigned int order
, int migratetype
) {}
795 static inline void set_buddy_order(struct page
*page
, unsigned int order
)
797 set_page_private(page
, order
);
798 __SetPageBuddy(page
);
802 * This function checks whether a page is free && is the buddy
803 * we can coalesce a page and its buddy if
804 * (a) the buddy is not in a hole (check before calling!) &&
805 * (b) the buddy is in the buddy system &&
806 * (c) a page and its buddy have the same order &&
807 * (d) a page and its buddy are in the same zone.
809 * For recording whether a page is in the buddy system, we set PageBuddy.
810 * Setting, clearing, and testing PageBuddy is serialized by zone->lock.
812 * For recording page's order, we use page_private(page).
814 static inline bool page_is_buddy(struct page
*page
, struct page
*buddy
,
817 if (!page_is_guard(buddy
) && !PageBuddy(buddy
))
820 if (buddy_order(buddy
) != order
)
824 * zone check is done late to avoid uselessly calculating
825 * zone/node ids for pages that could never merge.
827 if (page_zone_id(page
) != page_zone_id(buddy
))
830 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
835 #ifdef CONFIG_COMPACTION
836 static inline struct capture_control
*task_capc(struct zone
*zone
)
838 struct capture_control
*capc
= current
->capture_control
;
840 return unlikely(capc
) &&
841 !(current
->flags
& PF_KTHREAD
) &&
843 capc
->cc
->zone
== zone
? capc
: NULL
;
847 compaction_capture(struct capture_control
*capc
, struct page
*page
,
848 int order
, int migratetype
)
850 if (!capc
|| order
!= capc
->cc
->order
)
853 /* Do not accidentally pollute CMA or isolated regions*/
854 if (is_migrate_cma(migratetype
) ||
855 is_migrate_isolate(migratetype
))
859 * Do not let lower order allocations polluate a movable pageblock.
860 * This might let an unmovable request use a reclaimable pageblock
861 * and vice-versa but no more than normal fallback logic which can
862 * have trouble finding a high-order free page.
864 if (order
< pageblock_order
&& migratetype
== MIGRATE_MOVABLE
)
872 static inline struct capture_control
*task_capc(struct zone
*zone
)
878 compaction_capture(struct capture_control
*capc
, struct page
*page
,
879 int order
, int migratetype
)
883 #endif /* CONFIG_COMPACTION */
885 /* Used for pages not on another list */
886 static inline void add_to_free_list(struct page
*page
, struct zone
*zone
,
887 unsigned int order
, int migratetype
)
889 struct free_area
*area
= &zone
->free_area
[order
];
891 list_add(&page
->lru
, &area
->free_list
[migratetype
]);
895 /* Used for pages not on another list */
896 static inline void add_to_free_list_tail(struct page
*page
, struct zone
*zone
,
897 unsigned int order
, int migratetype
)
899 struct free_area
*area
= &zone
->free_area
[order
];
901 list_add_tail(&page
->lru
, &area
->free_list
[migratetype
]);
906 * Used for pages which are on another list. Move the pages to the tail
907 * of the list - so the moved pages won't immediately be considered for
908 * allocation again (e.g., optimization for memory onlining).
910 static inline void move_to_free_list(struct page
*page
, struct zone
*zone
,
911 unsigned int order
, int migratetype
)
913 struct free_area
*area
= &zone
->free_area
[order
];
915 list_move_tail(&page
->lru
, &area
->free_list
[migratetype
]);
918 static inline void del_page_from_free_list(struct page
*page
, struct zone
*zone
,
921 /* clear reported state and update reported page count */
922 if (page_reported(page
))
923 __ClearPageReported(page
);
925 list_del(&page
->lru
);
926 __ClearPageBuddy(page
);
927 set_page_private(page
, 0);
928 zone
->free_area
[order
].nr_free
--;
932 * If this is not the largest possible page, check if the buddy
933 * of the next-highest order is free. If it is, it's possible
934 * that pages are being freed that will coalesce soon. In case,
935 * that is happening, add the free page to the tail of the list
936 * so it's less likely to be used soon and more likely to be merged
937 * as a higher order page
940 buddy_merge_likely(unsigned long pfn
, unsigned long buddy_pfn
,
941 struct page
*page
, unsigned int order
)
943 struct page
*higher_page
, *higher_buddy
;
944 unsigned long combined_pfn
;
946 if (order
>= MAX_ORDER
- 2)
949 if (!pfn_valid_within(buddy_pfn
))
952 combined_pfn
= buddy_pfn
& pfn
;
953 higher_page
= page
+ (combined_pfn
- pfn
);
954 buddy_pfn
= __find_buddy_pfn(combined_pfn
, order
+ 1);
955 higher_buddy
= higher_page
+ (buddy_pfn
- combined_pfn
);
957 return pfn_valid_within(buddy_pfn
) &&
958 page_is_buddy(higher_page
, higher_buddy
, order
+ 1);
962 * Freeing function for a buddy system allocator.
964 * The concept of a buddy system is to maintain direct-mapped table
965 * (containing bit values) for memory blocks of various "orders".
966 * The bottom level table contains the map for the smallest allocatable
967 * units of memory (here, pages), and each level above it describes
968 * pairs of units from the levels below, hence, "buddies".
969 * At a high level, all that happens here is marking the table entry
970 * at the bottom level available, and propagating the changes upward
971 * as necessary, plus some accounting needed to play nicely with other
972 * parts of the VM system.
973 * At each level, we keep a list of pages, which are heads of continuous
974 * free pages of length of (1 << order) and marked with PageBuddy.
975 * Page's order is recorded in page_private(page) field.
976 * So when we are allocating or freeing one, we can derive the state of the
977 * other. That is, if we allocate a small block, and both were
978 * free, the remainder of the region must be split into blocks.
979 * If a block is freed, and its buddy is also free, then this
980 * triggers coalescing into a block of larger size.
985 static inline void __free_one_page(struct page
*page
,
987 struct zone
*zone
, unsigned int order
,
988 int migratetype
, fpi_t fpi_flags
)
990 struct capture_control
*capc
= task_capc(zone
);
991 unsigned long buddy_pfn
;
992 unsigned long combined_pfn
;
993 unsigned int max_order
;
997 max_order
= min_t(unsigned int, MAX_ORDER
, pageblock_order
+ 1);
999 VM_BUG_ON(!zone_is_initialized(zone
));
1000 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
1002 VM_BUG_ON(migratetype
== -1);
1003 if (likely(!is_migrate_isolate(migratetype
)))
1004 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
1006 VM_BUG_ON_PAGE(pfn
& ((1 << order
) - 1), page
);
1007 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
1010 while (order
< max_order
- 1) {
1011 if (compaction_capture(capc
, page
, order
, migratetype
)) {
1012 __mod_zone_freepage_state(zone
, -(1 << order
),
1016 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
1017 buddy
= page
+ (buddy_pfn
- pfn
);
1019 if (!pfn_valid_within(buddy_pfn
))
1021 if (!page_is_buddy(page
, buddy
, order
))
1024 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
1025 * merge with it and move up one order.
1027 if (page_is_guard(buddy
))
1028 clear_page_guard(zone
, buddy
, order
, migratetype
);
1030 del_page_from_free_list(buddy
, zone
, order
);
1031 combined_pfn
= buddy_pfn
& pfn
;
1032 page
= page
+ (combined_pfn
- pfn
);
1036 if (max_order
< MAX_ORDER
) {
1037 /* If we are here, it means order is >= pageblock_order.
1038 * We want to prevent merge between freepages on isolate
1039 * pageblock and normal pageblock. Without this, pageblock
1040 * isolation could cause incorrect freepage or CMA accounting.
1042 * We don't want to hit this code for the more frequent
1043 * low-order merging.
1045 if (unlikely(has_isolate_pageblock(zone
))) {
1048 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
1049 buddy
= page
+ (buddy_pfn
- pfn
);
1050 buddy_mt
= get_pageblock_migratetype(buddy
);
1052 if (migratetype
!= buddy_mt
1053 && (is_migrate_isolate(migratetype
) ||
1054 is_migrate_isolate(buddy_mt
)))
1058 goto continue_merging
;
1062 set_buddy_order(page
, order
);
1064 if (fpi_flags
& FPI_TO_TAIL
)
1066 else if (is_shuffle_order(order
))
1067 to_tail
= shuffle_pick_tail();
1069 to_tail
= buddy_merge_likely(pfn
, buddy_pfn
, page
, order
);
1072 add_to_free_list_tail(page
, zone
, order
, migratetype
);
1074 add_to_free_list(page
, zone
, order
, migratetype
);
1076 /* Notify page reporting subsystem of freed page */
1077 if (!(fpi_flags
& FPI_SKIP_REPORT_NOTIFY
))
1078 page_reporting_notify_free(order
);
1082 * A bad page could be due to a number of fields. Instead of multiple branches,
1083 * try and check multiple fields with one check. The caller must do a detailed
1084 * check if necessary.
1086 static inline bool page_expected_state(struct page
*page
,
1087 unsigned long check_flags
)
1089 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1092 if (unlikely((unsigned long)page
->mapping
|
1093 page_ref_count(page
) |
1095 (unsigned long)page
->mem_cgroup
|
1097 (page
->flags
& check_flags
)))
1103 static const char *page_bad_reason(struct page
*page
, unsigned long flags
)
1105 const char *bad_reason
= NULL
;
1107 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1108 bad_reason
= "nonzero mapcount";
1109 if (unlikely(page
->mapping
!= NULL
))
1110 bad_reason
= "non-NULL mapping";
1111 if (unlikely(page_ref_count(page
) != 0))
1112 bad_reason
= "nonzero _refcount";
1113 if (unlikely(page
->flags
& flags
)) {
1114 if (flags
== PAGE_FLAGS_CHECK_AT_PREP
)
1115 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag(s) set";
1117 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
1120 if (unlikely(page
->mem_cgroup
))
1121 bad_reason
= "page still charged to cgroup";
1126 static void check_free_page_bad(struct page
*page
)
1129 page_bad_reason(page
, PAGE_FLAGS_CHECK_AT_FREE
));
1132 static inline int check_free_page(struct page
*page
)
1134 if (likely(page_expected_state(page
, PAGE_FLAGS_CHECK_AT_FREE
)))
1137 /* Something has gone sideways, find it */
1138 check_free_page_bad(page
);
1142 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
1147 * We rely page->lru.next never has bit 0 set, unless the page
1148 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
1150 BUILD_BUG_ON((unsigned long)LIST_POISON1
& 1);
1152 if (!IS_ENABLED(CONFIG_DEBUG_VM
)) {
1156 switch (page
- head_page
) {
1158 /* the first tail page: ->mapping may be compound_mapcount() */
1159 if (unlikely(compound_mapcount(page
))) {
1160 bad_page(page
, "nonzero compound_mapcount");
1166 * the second tail page: ->mapping is
1167 * deferred_list.next -- ignore value.
1171 if (page
->mapping
!= TAIL_MAPPING
) {
1172 bad_page(page
, "corrupted mapping in tail page");
1177 if (unlikely(!PageTail(page
))) {
1178 bad_page(page
, "PageTail not set");
1181 if (unlikely(compound_head(page
) != head_page
)) {
1182 bad_page(page
, "compound_head not consistent");
1187 page
->mapping
= NULL
;
1188 clear_compound_head(page
);
1192 static void kernel_init_free_pages(struct page
*page
, int numpages
)
1196 /* s390's use of memset() could override KASAN redzones. */
1197 kasan_disable_current();
1198 for (i
= 0; i
< numpages
; i
++)
1199 clear_highpage(page
+ i
);
1200 kasan_enable_current();
1203 static __always_inline
bool free_pages_prepare(struct page
*page
,
1204 unsigned int order
, bool check_free
)
1208 VM_BUG_ON_PAGE(PageTail(page
), page
);
1210 trace_mm_page_free(page
, order
);
1212 if (unlikely(PageHWPoison(page
)) && !order
) {
1214 * Do not let hwpoison pages hit pcplists/buddy
1215 * Untie memcg state and reset page's owner
1217 if (memcg_kmem_enabled() && PageKmemcg(page
))
1218 __memcg_kmem_uncharge_page(page
, order
);
1219 reset_page_owner(page
, order
);
1224 * Check tail pages before head page information is cleared to
1225 * avoid checking PageCompound for order-0 pages.
1227 if (unlikely(order
)) {
1228 bool compound
= PageCompound(page
);
1231 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
1234 ClearPageDoubleMap(page
);
1235 for (i
= 1; i
< (1 << order
); i
++) {
1237 bad
+= free_tail_pages_check(page
, page
+ i
);
1238 if (unlikely(check_free_page(page
+ i
))) {
1242 (page
+ i
)->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1245 if (PageMappingFlags(page
))
1246 page
->mapping
= NULL
;
1247 if (memcg_kmem_enabled() && PageKmemcg(page
))
1248 __memcg_kmem_uncharge_page(page
, order
);
1250 bad
+= check_free_page(page
);
1254 page_cpupid_reset_last(page
);
1255 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1256 reset_page_owner(page
, order
);
1258 if (!PageHighMem(page
)) {
1259 debug_check_no_locks_freed(page_address(page
),
1260 PAGE_SIZE
<< order
);
1261 debug_check_no_obj_freed(page_address(page
),
1262 PAGE_SIZE
<< order
);
1264 if (want_init_on_free())
1265 kernel_init_free_pages(page
, 1 << order
);
1267 kernel_poison_pages(page
, 1 << order
, 0);
1269 * arch_free_page() can make the page's contents inaccessible. s390
1270 * does this. So nothing which can access the page's contents should
1271 * happen after this.
1273 arch_free_page(page
, order
);
1275 if (debug_pagealloc_enabled_static())
1276 kernel_map_pages(page
, 1 << order
, 0);
1278 kasan_free_nondeferred_pages(page
, order
);
1283 #ifdef CONFIG_DEBUG_VM
1285 * With DEBUG_VM enabled, order-0 pages are checked immediately when being freed
1286 * to pcp lists. With debug_pagealloc also enabled, they are also rechecked when
1287 * moved from pcp lists to free lists.
1289 static bool free_pcp_prepare(struct page
*page
)
1291 return free_pages_prepare(page
, 0, true);
1294 static bool bulkfree_pcp_prepare(struct page
*page
)
1296 if (debug_pagealloc_enabled_static())
1297 return check_free_page(page
);
1303 * With DEBUG_VM disabled, order-0 pages being freed are checked only when
1304 * moving from pcp lists to free list in order to reduce overhead. With
1305 * debug_pagealloc enabled, they are checked also immediately when being freed
1308 static bool free_pcp_prepare(struct page
*page
)
1310 if (debug_pagealloc_enabled_static())
1311 return free_pages_prepare(page
, 0, true);
1313 return free_pages_prepare(page
, 0, false);
1316 static bool bulkfree_pcp_prepare(struct page
*page
)
1318 return check_free_page(page
);
1320 #endif /* CONFIG_DEBUG_VM */
1322 static inline void prefetch_buddy(struct page
*page
)
1324 unsigned long pfn
= page_to_pfn(page
);
1325 unsigned long buddy_pfn
= __find_buddy_pfn(pfn
, 0);
1326 struct page
*buddy
= page
+ (buddy_pfn
- pfn
);
1332 * Frees a number of pages from the PCP lists
1333 * Assumes all pages on list are in same zone, and of same order.
1334 * count is the number of pages to free.
1336 * If the zone was previously in an "all pages pinned" state then look to
1337 * see if this freeing clears that state.
1339 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1340 * pinned" detection logic.
1342 static void free_pcppages_bulk(struct zone
*zone
, int count
,
1343 struct per_cpu_pages
*pcp
)
1345 int migratetype
= 0;
1347 int prefetch_nr
= 0;
1348 bool isolated_pageblocks
;
1349 struct page
*page
, *tmp
;
1353 * Ensure proper count is passed which otherwise would stuck in the
1354 * below while (list_empty(list)) loop.
1356 count
= min(pcp
->count
, count
);
1358 struct list_head
*list
;
1361 * Remove pages from lists in a round-robin fashion. A
1362 * batch_free count is maintained that is incremented when an
1363 * empty list is encountered. This is so more pages are freed
1364 * off fuller lists instead of spinning excessively around empty
1369 if (++migratetype
== MIGRATE_PCPTYPES
)
1371 list
= &pcp
->lists
[migratetype
];
1372 } while (list_empty(list
));
1374 /* This is the only non-empty list. Free them all. */
1375 if (batch_free
== MIGRATE_PCPTYPES
)
1379 page
= list_last_entry(list
, struct page
, lru
);
1380 /* must delete to avoid corrupting pcp list */
1381 list_del(&page
->lru
);
1384 if (bulkfree_pcp_prepare(page
))
1387 list_add_tail(&page
->lru
, &head
);
1390 * We are going to put the page back to the global
1391 * pool, prefetch its buddy to speed up later access
1392 * under zone->lock. It is believed the overhead of
1393 * an additional test and calculating buddy_pfn here
1394 * can be offset by reduced memory latency later. To
1395 * avoid excessive prefetching due to large count, only
1396 * prefetch buddy for the first pcp->batch nr of pages.
1398 if (prefetch_nr
++ < pcp
->batch
)
1399 prefetch_buddy(page
);
1400 } while (--count
&& --batch_free
&& !list_empty(list
));
1403 spin_lock(&zone
->lock
);
1404 isolated_pageblocks
= has_isolate_pageblock(zone
);
1407 * Use safe version since after __free_one_page(),
1408 * page->lru.next will not point to original list.
1410 list_for_each_entry_safe(page
, tmp
, &head
, lru
) {
1411 int mt
= get_pcppage_migratetype(page
);
1412 /* MIGRATE_ISOLATE page should not go to pcplists */
1413 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
1414 /* Pageblock could have been isolated meanwhile */
1415 if (unlikely(isolated_pageblocks
))
1416 mt
= get_pageblock_migratetype(page
);
1418 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
, FPI_NONE
);
1419 trace_mm_page_pcpu_drain(page
, 0, mt
);
1421 spin_unlock(&zone
->lock
);
1424 static void free_one_page(struct zone
*zone
,
1425 struct page
*page
, unsigned long pfn
,
1427 int migratetype
, fpi_t fpi_flags
)
1429 spin_lock(&zone
->lock
);
1430 if (unlikely(has_isolate_pageblock(zone
) ||
1431 is_migrate_isolate(migratetype
))) {
1432 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1434 __free_one_page(page
, pfn
, zone
, order
, migratetype
, fpi_flags
);
1435 spin_unlock(&zone
->lock
);
1438 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
1439 unsigned long zone
, int nid
)
1441 mm_zero_struct_page(page
);
1442 set_page_links(page
, zone
, nid
, pfn
);
1443 init_page_count(page
);
1444 page_mapcount_reset(page
);
1445 page_cpupid_reset_last(page
);
1446 page_kasan_tag_reset(page
);
1448 INIT_LIST_HEAD(&page
->lru
);
1449 #ifdef WANT_PAGE_VIRTUAL
1450 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1451 if (!is_highmem_idx(zone
))
1452 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
1456 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1457 static void __meminit
init_reserved_page(unsigned long pfn
)
1462 if (!early_page_uninitialised(pfn
))
1465 nid
= early_pfn_to_nid(pfn
);
1466 pgdat
= NODE_DATA(nid
);
1468 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1469 struct zone
*zone
= &pgdat
->node_zones
[zid
];
1471 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
1474 __init_single_page(pfn_to_page(pfn
), pfn
, zid
, nid
);
1477 static inline void init_reserved_page(unsigned long pfn
)
1480 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1483 * Initialised pages do not have PageReserved set. This function is
1484 * called for each range allocated by the bootmem allocator and
1485 * marks the pages PageReserved. The remaining valid pages are later
1486 * sent to the buddy page allocator.
1488 void __meminit
reserve_bootmem_region(phys_addr_t start
, phys_addr_t end
)
1490 unsigned long start_pfn
= PFN_DOWN(start
);
1491 unsigned long end_pfn
= PFN_UP(end
);
1493 for (; start_pfn
< end_pfn
; start_pfn
++) {
1494 if (pfn_valid(start_pfn
)) {
1495 struct page
*page
= pfn_to_page(start_pfn
);
1497 init_reserved_page(start_pfn
);
1499 /* Avoid false-positive PageTail() */
1500 INIT_LIST_HEAD(&page
->lru
);
1503 * no need for atomic set_bit because the struct
1504 * page is not visible yet so nobody should
1507 __SetPageReserved(page
);
1512 static void __free_pages_ok(struct page
*page
, unsigned int order
,
1515 unsigned long flags
;
1517 unsigned long pfn
= page_to_pfn(page
);
1519 if (!free_pages_prepare(page
, order
, true))
1522 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1523 local_irq_save(flags
);
1524 __count_vm_events(PGFREE
, 1 << order
);
1525 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
,
1527 local_irq_restore(flags
);
1530 void __free_pages_core(struct page
*page
, unsigned int order
)
1532 unsigned int nr_pages
= 1 << order
;
1533 struct page
*p
= page
;
1537 * When initializing the memmap, __init_single_page() sets the refcount
1538 * of all pages to 1 ("allocated"/"not free"). We have to set the
1539 * refcount of all involved pages to 0.
1542 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
1544 __ClearPageReserved(p
);
1545 set_page_count(p
, 0);
1547 __ClearPageReserved(p
);
1548 set_page_count(p
, 0);
1550 atomic_long_add(nr_pages
, &page_zone(page
)->managed_pages
);
1553 * Bypass PCP and place fresh pages right to the tail, primarily
1554 * relevant for memory onlining.
1556 __free_pages_ok(page
, order
, FPI_TO_TAIL
);
1559 #ifdef CONFIG_NEED_MULTIPLE_NODES
1561 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1563 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
1566 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
1568 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
1569 struct mminit_pfnnid_cache
*state
)
1571 unsigned long start_pfn
, end_pfn
;
1574 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
1575 return state
->last_nid
;
1577 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
1578 if (nid
!= NUMA_NO_NODE
) {
1579 state
->last_start
= start_pfn
;
1580 state
->last_end
= end_pfn
;
1581 state
->last_nid
= nid
;
1586 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
1588 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1590 static DEFINE_SPINLOCK(early_pfn_lock
);
1593 spin_lock(&early_pfn_lock
);
1594 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1596 nid
= first_online_node
;
1597 spin_unlock(&early_pfn_lock
);
1601 #endif /* CONFIG_NEED_MULTIPLE_NODES */
1603 void __init
memblock_free_pages(struct page
*page
, unsigned long pfn
,
1606 if (early_page_uninitialised(pfn
))
1608 __free_pages_core(page
, order
);
1612 * Check that the whole (or subset of) a pageblock given by the interval of
1613 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1614 * with the migration of free compaction scanner. The scanners then need to
1615 * use only pfn_valid_within() check for arches that allow holes within
1618 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1620 * It's possible on some configurations to have a setup like node0 node1 node0
1621 * i.e. it's possible that all pages within a zones range of pages do not
1622 * belong to a single zone. We assume that a border between node0 and node1
1623 * can occur within a single pageblock, but not a node0 node1 node0
1624 * interleaving within a single pageblock. It is therefore sufficient to check
1625 * the first and last page of a pageblock and avoid checking each individual
1626 * page in a pageblock.
1628 struct page
*__pageblock_pfn_to_page(unsigned long start_pfn
,
1629 unsigned long end_pfn
, struct zone
*zone
)
1631 struct page
*start_page
;
1632 struct page
*end_page
;
1634 /* end_pfn is one past the range we are checking */
1637 if (!pfn_valid(start_pfn
) || !pfn_valid(end_pfn
))
1640 start_page
= pfn_to_online_page(start_pfn
);
1644 if (page_zone(start_page
) != zone
)
1647 end_page
= pfn_to_page(end_pfn
);
1649 /* This gives a shorter code than deriving page_zone(end_page) */
1650 if (page_zone_id(start_page
) != page_zone_id(end_page
))
1656 void set_zone_contiguous(struct zone
*zone
)
1658 unsigned long block_start_pfn
= zone
->zone_start_pfn
;
1659 unsigned long block_end_pfn
;
1661 block_end_pfn
= ALIGN(block_start_pfn
+ 1, pageblock_nr_pages
);
1662 for (; block_start_pfn
< zone_end_pfn(zone
);
1663 block_start_pfn
= block_end_pfn
,
1664 block_end_pfn
+= pageblock_nr_pages
) {
1666 block_end_pfn
= min(block_end_pfn
, zone_end_pfn(zone
));
1668 if (!__pageblock_pfn_to_page(block_start_pfn
,
1669 block_end_pfn
, zone
))
1674 /* We confirm that there is no hole */
1675 zone
->contiguous
= true;
1678 void clear_zone_contiguous(struct zone
*zone
)
1680 zone
->contiguous
= false;
1683 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1684 static void __init
deferred_free_range(unsigned long pfn
,
1685 unsigned long nr_pages
)
1693 page
= pfn_to_page(pfn
);
1695 /* Free a large naturally-aligned chunk if possible */
1696 if (nr_pages
== pageblock_nr_pages
&&
1697 (pfn
& (pageblock_nr_pages
- 1)) == 0) {
1698 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1699 __free_pages_core(page
, pageblock_order
);
1703 for (i
= 0; i
< nr_pages
; i
++, page
++, pfn
++) {
1704 if ((pfn
& (pageblock_nr_pages
- 1)) == 0)
1705 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1706 __free_pages_core(page
, 0);
1710 /* Completion tracking for deferred_init_memmap() threads */
1711 static atomic_t pgdat_init_n_undone __initdata
;
1712 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1714 static inline void __init
pgdat_init_report_one_done(void)
1716 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1717 complete(&pgdat_init_all_done_comp
);
1721 * Returns true if page needs to be initialized or freed to buddy allocator.
1723 * First we check if pfn is valid on architectures where it is possible to have
1724 * holes within pageblock_nr_pages. On systems where it is not possible, this
1725 * function is optimized out.
1727 * Then, we check if a current large page is valid by only checking the validity
1730 static inline bool __init
deferred_pfn_valid(unsigned long pfn
)
1732 if (!pfn_valid_within(pfn
))
1734 if (!(pfn
& (pageblock_nr_pages
- 1)) && !pfn_valid(pfn
))
1740 * Free pages to buddy allocator. Try to free aligned pages in
1741 * pageblock_nr_pages sizes.
1743 static void __init
deferred_free_pages(unsigned long pfn
,
1744 unsigned long end_pfn
)
1746 unsigned long nr_pgmask
= pageblock_nr_pages
- 1;
1747 unsigned long nr_free
= 0;
1749 for (; pfn
< end_pfn
; pfn
++) {
1750 if (!deferred_pfn_valid(pfn
)) {
1751 deferred_free_range(pfn
- nr_free
, nr_free
);
1753 } else if (!(pfn
& nr_pgmask
)) {
1754 deferred_free_range(pfn
- nr_free
, nr_free
);
1760 /* Free the last block of pages to allocator */
1761 deferred_free_range(pfn
- nr_free
, nr_free
);
1765 * Initialize struct pages. We minimize pfn page lookups and scheduler checks
1766 * by performing it only once every pageblock_nr_pages.
1767 * Return number of pages initialized.
1769 static unsigned long __init
deferred_init_pages(struct zone
*zone
,
1771 unsigned long end_pfn
)
1773 unsigned long nr_pgmask
= pageblock_nr_pages
- 1;
1774 int nid
= zone_to_nid(zone
);
1775 unsigned long nr_pages
= 0;
1776 int zid
= zone_idx(zone
);
1777 struct page
*page
= NULL
;
1779 for (; pfn
< end_pfn
; pfn
++) {
1780 if (!deferred_pfn_valid(pfn
)) {
1783 } else if (!page
|| !(pfn
& nr_pgmask
)) {
1784 page
= pfn_to_page(pfn
);
1788 __init_single_page(page
, pfn
, zid
, nid
);
1795 * This function is meant to pre-load the iterator for the zone init.
1796 * Specifically it walks through the ranges until we are caught up to the
1797 * first_init_pfn value and exits there. If we never encounter the value we
1798 * return false indicating there are no valid ranges left.
1801 deferred_init_mem_pfn_range_in_zone(u64
*i
, struct zone
*zone
,
1802 unsigned long *spfn
, unsigned long *epfn
,
1803 unsigned long first_init_pfn
)
1808 * Start out by walking through the ranges in this zone that have
1809 * already been initialized. We don't need to do anything with them
1810 * so we just need to flush them out of the system.
1812 for_each_free_mem_pfn_range_in_zone(j
, zone
, spfn
, epfn
) {
1813 if (*epfn
<= first_init_pfn
)
1815 if (*spfn
< first_init_pfn
)
1816 *spfn
= first_init_pfn
;
1825 * Initialize and free pages. We do it in two loops: first we initialize
1826 * struct page, then free to buddy allocator, because while we are
1827 * freeing pages we can access pages that are ahead (computing buddy
1828 * page in __free_one_page()).
1830 * In order to try and keep some memory in the cache we have the loop
1831 * broken along max page order boundaries. This way we will not cause
1832 * any issues with the buddy page computation.
1834 static unsigned long __init
1835 deferred_init_maxorder(u64
*i
, struct zone
*zone
, unsigned long *start_pfn
,
1836 unsigned long *end_pfn
)
1838 unsigned long mo_pfn
= ALIGN(*start_pfn
+ 1, MAX_ORDER_NR_PAGES
);
1839 unsigned long spfn
= *start_pfn
, epfn
= *end_pfn
;
1840 unsigned long nr_pages
= 0;
1843 /* First we loop through and initialize the page values */
1844 for_each_free_mem_pfn_range_in_zone_from(j
, zone
, start_pfn
, end_pfn
) {
1847 if (mo_pfn
<= *start_pfn
)
1850 t
= min(mo_pfn
, *end_pfn
);
1851 nr_pages
+= deferred_init_pages(zone
, *start_pfn
, t
);
1853 if (mo_pfn
< *end_pfn
) {
1854 *start_pfn
= mo_pfn
;
1859 /* Reset values and now loop through freeing pages as needed */
1862 for_each_free_mem_pfn_range_in_zone_from(j
, zone
, &spfn
, &epfn
) {
1868 t
= min(mo_pfn
, epfn
);
1869 deferred_free_pages(spfn
, t
);
1879 deferred_init_memmap_chunk(unsigned long start_pfn
, unsigned long end_pfn
,
1882 unsigned long spfn
, epfn
;
1883 struct zone
*zone
= arg
;
1886 deferred_init_mem_pfn_range_in_zone(&i
, zone
, &spfn
, &epfn
, start_pfn
);
1889 * Initialize and free pages in MAX_ORDER sized increments so that we
1890 * can avoid introducing any issues with the buddy allocator.
1892 while (spfn
< end_pfn
) {
1893 deferred_init_maxorder(&i
, zone
, &spfn
, &epfn
);
1898 /* An arch may override for more concurrency. */
1900 deferred_page_init_max_threads(const struct cpumask
*node_cpumask
)
1905 /* Initialise remaining memory on a node */
1906 static int __init
deferred_init_memmap(void *data
)
1908 pg_data_t
*pgdat
= data
;
1909 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1910 unsigned long spfn
= 0, epfn
= 0;
1911 unsigned long first_init_pfn
, flags
;
1912 unsigned long start
= jiffies
;
1914 int zid
, max_threads
;
1917 /* Bind memory initialisation thread to a local node if possible */
1918 if (!cpumask_empty(cpumask
))
1919 set_cpus_allowed_ptr(current
, cpumask
);
1921 pgdat_resize_lock(pgdat
, &flags
);
1922 first_init_pfn
= pgdat
->first_deferred_pfn
;
1923 if (first_init_pfn
== ULONG_MAX
) {
1924 pgdat_resize_unlock(pgdat
, &flags
);
1925 pgdat_init_report_one_done();
1929 /* Sanity check boundaries */
1930 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1931 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1932 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1935 * Once we unlock here, the zone cannot be grown anymore, thus if an
1936 * interrupt thread must allocate this early in boot, zone must be
1937 * pre-grown prior to start of deferred page initialization.
1939 pgdat_resize_unlock(pgdat
, &flags
);
1941 /* Only the highest zone is deferred so find it */
1942 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1943 zone
= pgdat
->node_zones
+ zid
;
1944 if (first_init_pfn
< zone_end_pfn(zone
))
1948 /* If the zone is empty somebody else may have cleared out the zone */
1949 if (!deferred_init_mem_pfn_range_in_zone(&i
, zone
, &spfn
, &epfn
,
1953 max_threads
= deferred_page_init_max_threads(cpumask
);
1955 while (spfn
< epfn
) {
1956 unsigned long epfn_align
= ALIGN(epfn
, PAGES_PER_SECTION
);
1957 struct padata_mt_job job
= {
1958 .thread_fn
= deferred_init_memmap_chunk
,
1961 .size
= epfn_align
- spfn
,
1962 .align
= PAGES_PER_SECTION
,
1963 .min_chunk
= PAGES_PER_SECTION
,
1964 .max_threads
= max_threads
,
1967 padata_do_multithreaded(&job
);
1968 deferred_init_mem_pfn_range_in_zone(&i
, zone
, &spfn
, &epfn
,
1972 /* Sanity check that the next zone really is unpopulated */
1973 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1975 pr_info("node %d deferred pages initialised in %ums\n",
1976 pgdat
->node_id
, jiffies_to_msecs(jiffies
- start
));
1978 pgdat_init_report_one_done();
1983 * If this zone has deferred pages, try to grow it by initializing enough
1984 * deferred pages to satisfy the allocation specified by order, rounded up to
1985 * the nearest PAGES_PER_SECTION boundary. So we're adding memory in increments
1986 * of SECTION_SIZE bytes by initializing struct pages in increments of
1987 * PAGES_PER_SECTION * sizeof(struct page) bytes.
1989 * Return true when zone was grown, otherwise return false. We return true even
1990 * when we grow less than requested, to let the caller decide if there are
1991 * enough pages to satisfy the allocation.
1993 * Note: We use noinline because this function is needed only during boot, and
1994 * it is called from a __ref function _deferred_grow_zone. This way we are
1995 * making sure that it is not inlined into permanent text section.
1997 static noinline
bool __init
1998 deferred_grow_zone(struct zone
*zone
, unsigned int order
)
2000 unsigned long nr_pages_needed
= ALIGN(1 << order
, PAGES_PER_SECTION
);
2001 pg_data_t
*pgdat
= zone
->zone_pgdat
;
2002 unsigned long first_deferred_pfn
= pgdat
->first_deferred_pfn
;
2003 unsigned long spfn
, epfn
, flags
;
2004 unsigned long nr_pages
= 0;
2007 /* Only the last zone may have deferred pages */
2008 if (zone_end_pfn(zone
) != pgdat_end_pfn(pgdat
))
2011 pgdat_resize_lock(pgdat
, &flags
);
2014 * If someone grew this zone while we were waiting for spinlock, return
2015 * true, as there might be enough pages already.
2017 if (first_deferred_pfn
!= pgdat
->first_deferred_pfn
) {
2018 pgdat_resize_unlock(pgdat
, &flags
);
2022 /* If the zone is empty somebody else may have cleared out the zone */
2023 if (!deferred_init_mem_pfn_range_in_zone(&i
, zone
, &spfn
, &epfn
,
2024 first_deferred_pfn
)) {
2025 pgdat
->first_deferred_pfn
= ULONG_MAX
;
2026 pgdat_resize_unlock(pgdat
, &flags
);
2027 /* Retry only once. */
2028 return first_deferred_pfn
!= ULONG_MAX
;
2032 * Initialize and free pages in MAX_ORDER sized increments so
2033 * that we can avoid introducing any issues with the buddy
2036 while (spfn
< epfn
) {
2037 /* update our first deferred PFN for this section */
2038 first_deferred_pfn
= spfn
;
2040 nr_pages
+= deferred_init_maxorder(&i
, zone
, &spfn
, &epfn
);
2041 touch_nmi_watchdog();
2043 /* We should only stop along section boundaries */
2044 if ((first_deferred_pfn
^ spfn
) < PAGES_PER_SECTION
)
2047 /* If our quota has been met we can stop here */
2048 if (nr_pages
>= nr_pages_needed
)
2052 pgdat
->first_deferred_pfn
= spfn
;
2053 pgdat_resize_unlock(pgdat
, &flags
);
2055 return nr_pages
> 0;
2059 * deferred_grow_zone() is __init, but it is called from
2060 * get_page_from_freelist() during early boot until deferred_pages permanently
2061 * disables this call. This is why we have refdata wrapper to avoid warning,
2062 * and to ensure that the function body gets unloaded.
2065 _deferred_grow_zone(struct zone
*zone
, unsigned int order
)
2067 return deferred_grow_zone(zone
, order
);
2070 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
2072 void __init
page_alloc_init_late(void)
2077 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
2079 /* There will be num_node_state(N_MEMORY) threads */
2080 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
2081 for_each_node_state(nid
, N_MEMORY
) {
2082 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
2085 /* Block until all are initialised */
2086 wait_for_completion(&pgdat_init_all_done_comp
);
2089 * The number of managed pages has changed due to the initialisation
2090 * so the pcpu batch and high limits needs to be updated or the limits
2091 * will be artificially small.
2093 for_each_populated_zone(zone
)
2094 zone_pcp_update(zone
);
2097 * We initialized the rest of the deferred pages. Permanently disable
2098 * on-demand struct page initialization.
2100 static_branch_disable(&deferred_pages
);
2102 /* Reinit limits that are based on free pages after the kernel is up */
2103 files_maxfiles_init();
2106 /* Discard memblock private memory */
2109 for_each_node_state(nid
, N_MEMORY
)
2110 shuffle_free_memory(NODE_DATA(nid
));
2112 for_each_populated_zone(zone
)
2113 set_zone_contiguous(zone
);
2117 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
2118 void __init
init_cma_reserved_pageblock(struct page
*page
)
2120 unsigned i
= pageblock_nr_pages
;
2121 struct page
*p
= page
;
2124 __ClearPageReserved(p
);
2125 set_page_count(p
, 0);
2128 set_pageblock_migratetype(page
, MIGRATE_CMA
);
2130 if (pageblock_order
>= MAX_ORDER
) {
2131 i
= pageblock_nr_pages
;
2134 set_page_refcounted(p
);
2135 __free_pages(p
, MAX_ORDER
- 1);
2136 p
+= MAX_ORDER_NR_PAGES
;
2137 } while (i
-= MAX_ORDER_NR_PAGES
);
2139 set_page_refcounted(page
);
2140 __free_pages(page
, pageblock_order
);
2143 adjust_managed_page_count(page
, pageblock_nr_pages
);
2148 * The order of subdivision here is critical for the IO subsystem.
2149 * Please do not alter this order without good reasons and regression
2150 * testing. Specifically, as large blocks of memory are subdivided,
2151 * the order in which smaller blocks are delivered depends on the order
2152 * they're subdivided in this function. This is the primary factor
2153 * influencing the order in which pages are delivered to the IO
2154 * subsystem according to empirical testing, and this is also justified
2155 * by considering the behavior of a buddy system containing a single
2156 * large block of memory acted on by a series of small allocations.
2157 * This behavior is a critical factor in sglist merging's success.
2161 static inline void expand(struct zone
*zone
, struct page
*page
,
2162 int low
, int high
, int migratetype
)
2164 unsigned long size
= 1 << high
;
2166 while (high
> low
) {
2169 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
2172 * Mark as guard pages (or page), that will allow to
2173 * merge back to allocator when buddy will be freed.
2174 * Corresponding page table entries will not be touched,
2175 * pages will stay not present in virtual address space
2177 if (set_page_guard(zone
, &page
[size
], high
, migratetype
))
2180 add_to_free_list(&page
[size
], zone
, high
, migratetype
);
2181 set_buddy_order(&page
[size
], high
);
2185 static void check_new_page_bad(struct page
*page
)
2187 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
2188 /* Don't complain about hwpoisoned pages */
2189 page_mapcount_reset(page
); /* remove PageBuddy */
2194 page_bad_reason(page
, PAGE_FLAGS_CHECK_AT_PREP
));
2198 * This page is about to be returned from the page allocator
2200 static inline int check_new_page(struct page
*page
)
2202 if (likely(page_expected_state(page
,
2203 PAGE_FLAGS_CHECK_AT_PREP
|__PG_HWPOISON
)))
2206 check_new_page_bad(page
);
2210 static inline bool free_pages_prezeroed(void)
2212 return (IS_ENABLED(CONFIG_PAGE_POISONING_ZERO
) &&
2213 page_poisoning_enabled()) || want_init_on_free();
2216 #ifdef CONFIG_DEBUG_VM
2218 * With DEBUG_VM enabled, order-0 pages are checked for expected state when
2219 * being allocated from pcp lists. With debug_pagealloc also enabled, they are
2220 * also checked when pcp lists are refilled from the free lists.
2222 static inline bool check_pcp_refill(struct page
*page
)
2224 if (debug_pagealloc_enabled_static())
2225 return check_new_page(page
);
2230 static inline bool check_new_pcp(struct page
*page
)
2232 return check_new_page(page
);
2236 * With DEBUG_VM disabled, free order-0 pages are checked for expected state
2237 * when pcp lists are being refilled from the free lists. With debug_pagealloc
2238 * enabled, they are also checked when being allocated from the pcp lists.
2240 static inline bool check_pcp_refill(struct page
*page
)
2242 return check_new_page(page
);
2244 static inline bool check_new_pcp(struct page
*page
)
2246 if (debug_pagealloc_enabled_static())
2247 return check_new_page(page
);
2251 #endif /* CONFIG_DEBUG_VM */
2253 static bool check_new_pages(struct page
*page
, unsigned int order
)
2256 for (i
= 0; i
< (1 << order
); i
++) {
2257 struct page
*p
= page
+ i
;
2259 if (unlikely(check_new_page(p
)))
2266 inline void post_alloc_hook(struct page
*page
, unsigned int order
,
2269 set_page_private(page
, 0);
2270 set_page_refcounted(page
);
2272 arch_alloc_page(page
, order
);
2273 if (debug_pagealloc_enabled_static())
2274 kernel_map_pages(page
, 1 << order
, 1);
2275 kasan_alloc_pages(page
, order
);
2276 kernel_poison_pages(page
, 1 << order
, 1);
2277 set_page_owner(page
, order
, gfp_flags
);
2280 static void prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
2281 unsigned int alloc_flags
)
2283 post_alloc_hook(page
, order
, gfp_flags
);
2285 if (!free_pages_prezeroed() && want_init_on_alloc(gfp_flags
))
2286 kernel_init_free_pages(page
, 1 << order
);
2288 if (order
&& (gfp_flags
& __GFP_COMP
))
2289 prep_compound_page(page
, order
);
2292 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
2293 * allocate the page. The expectation is that the caller is taking
2294 * steps that will free more memory. The caller should avoid the page
2295 * being used for !PFMEMALLOC purposes.
2297 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
2298 set_page_pfmemalloc(page
);
2300 clear_page_pfmemalloc(page
);
2304 * Go through the free lists for the given migratetype and remove
2305 * the smallest available page from the freelists
2307 static __always_inline
2308 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
2311 unsigned int current_order
;
2312 struct free_area
*area
;
2315 /* Find a page of the appropriate size in the preferred list */
2316 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
2317 area
= &(zone
->free_area
[current_order
]);
2318 page
= get_page_from_free_area(area
, migratetype
);
2321 del_page_from_free_list(page
, zone
, current_order
);
2322 expand(zone
, page
, order
, current_order
, migratetype
);
2323 set_pcppage_migratetype(page
, migratetype
);
2332 * This array describes the order lists are fallen back to when
2333 * the free lists for the desirable migrate type are depleted
2335 static int fallbacks
[MIGRATE_TYPES
][3] = {
2336 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
2337 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_TYPES
},
2338 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
2340 [MIGRATE_CMA
] = { MIGRATE_TYPES
}, /* Never used */
2342 #ifdef CONFIG_MEMORY_ISOLATION
2343 [MIGRATE_ISOLATE
] = { MIGRATE_TYPES
}, /* Never used */
2348 static __always_inline
struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
2351 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
2354 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
2355 unsigned int order
) { return NULL
; }
2359 * Move the free pages in a range to the freelist tail of the requested type.
2360 * Note that start_page and end_pages are not aligned on a pageblock
2361 * boundary. If alignment is required, use move_freepages_block()
2363 static int move_freepages(struct zone
*zone
,
2364 struct page
*start_page
, struct page
*end_page
,
2365 int migratetype
, int *num_movable
)
2369 int pages_moved
= 0;
2371 for (page
= start_page
; page
<= end_page
;) {
2372 if (!pfn_valid_within(page_to_pfn(page
))) {
2377 if (!PageBuddy(page
)) {
2379 * We assume that pages that could be isolated for
2380 * migration are movable. But we don't actually try
2381 * isolating, as that would be expensive.
2384 (PageLRU(page
) || __PageMovable(page
)))
2391 /* Make sure we are not inadvertently changing nodes */
2392 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
2393 VM_BUG_ON_PAGE(page_zone(page
) != zone
, page
);
2395 order
= buddy_order(page
);
2396 move_to_free_list(page
, zone
, order
, migratetype
);
2398 pages_moved
+= 1 << order
;
2404 int move_freepages_block(struct zone
*zone
, struct page
*page
,
2405 int migratetype
, int *num_movable
)
2407 unsigned long start_pfn
, end_pfn
;
2408 struct page
*start_page
, *end_page
;
2413 start_pfn
= page_to_pfn(page
);
2414 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
2415 start_page
= pfn_to_page(start_pfn
);
2416 end_page
= start_page
+ pageblock_nr_pages
- 1;
2417 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
2419 /* Do not cross zone boundaries */
2420 if (!zone_spans_pfn(zone
, start_pfn
))
2422 if (!zone_spans_pfn(zone
, end_pfn
))
2425 return move_freepages(zone
, start_page
, end_page
, migratetype
,
2429 static void change_pageblock_range(struct page
*pageblock_page
,
2430 int start_order
, int migratetype
)
2432 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
2434 while (nr_pageblocks
--) {
2435 set_pageblock_migratetype(pageblock_page
, migratetype
);
2436 pageblock_page
+= pageblock_nr_pages
;
2441 * When we are falling back to another migratetype during allocation, try to
2442 * steal extra free pages from the same pageblocks to satisfy further
2443 * allocations, instead of polluting multiple pageblocks.
2445 * If we are stealing a relatively large buddy page, it is likely there will
2446 * be more free pages in the pageblock, so try to steal them all. For
2447 * reclaimable and unmovable allocations, we steal regardless of page size,
2448 * as fragmentation caused by those allocations polluting movable pageblocks
2449 * is worse than movable allocations stealing from unmovable and reclaimable
2452 static bool can_steal_fallback(unsigned int order
, int start_mt
)
2455 * Leaving this order check is intended, although there is
2456 * relaxed order check in next check. The reason is that
2457 * we can actually steal whole pageblock if this condition met,
2458 * but, below check doesn't guarantee it and that is just heuristic
2459 * so could be changed anytime.
2461 if (order
>= pageblock_order
)
2464 if (order
>= pageblock_order
/ 2 ||
2465 start_mt
== MIGRATE_RECLAIMABLE
||
2466 start_mt
== MIGRATE_UNMOVABLE
||
2467 page_group_by_mobility_disabled
)
2473 static inline void boost_watermark(struct zone
*zone
)
2475 unsigned long max_boost
;
2477 if (!watermark_boost_factor
)
2480 * Don't bother in zones that are unlikely to produce results.
2481 * On small machines, including kdump capture kernels running
2482 * in a small area, boosting the watermark can cause an out of
2483 * memory situation immediately.
2485 if ((pageblock_nr_pages
* 4) > zone_managed_pages(zone
))
2488 max_boost
= mult_frac(zone
->_watermark
[WMARK_HIGH
],
2489 watermark_boost_factor
, 10000);
2492 * high watermark may be uninitialised if fragmentation occurs
2493 * very early in boot so do not boost. We do not fall
2494 * through and boost by pageblock_nr_pages as failing
2495 * allocations that early means that reclaim is not going
2496 * to help and it may even be impossible to reclaim the
2497 * boosted watermark resulting in a hang.
2502 max_boost
= max(pageblock_nr_pages
, max_boost
);
2504 zone
->watermark_boost
= min(zone
->watermark_boost
+ pageblock_nr_pages
,
2509 * This function implements actual steal behaviour. If order is large enough,
2510 * we can steal whole pageblock. If not, we first move freepages in this
2511 * pageblock to our migratetype and determine how many already-allocated pages
2512 * are there in the pageblock with a compatible migratetype. If at least half
2513 * of pages are free or compatible, we can change migratetype of the pageblock
2514 * itself, so pages freed in the future will be put on the correct free list.
2516 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
2517 unsigned int alloc_flags
, int start_type
, bool whole_block
)
2519 unsigned int current_order
= buddy_order(page
);
2520 int free_pages
, movable_pages
, alike_pages
;
2523 old_block_type
= get_pageblock_migratetype(page
);
2526 * This can happen due to races and we want to prevent broken
2527 * highatomic accounting.
2529 if (is_migrate_highatomic(old_block_type
))
2532 /* Take ownership for orders >= pageblock_order */
2533 if (current_order
>= pageblock_order
) {
2534 change_pageblock_range(page
, current_order
, start_type
);
2539 * Boost watermarks to increase reclaim pressure to reduce the
2540 * likelihood of future fallbacks. Wake kswapd now as the node
2541 * may be balanced overall and kswapd will not wake naturally.
2543 boost_watermark(zone
);
2544 if (alloc_flags
& ALLOC_KSWAPD
)
2545 set_bit(ZONE_BOOSTED_WATERMARK
, &zone
->flags
);
2547 /* We are not allowed to try stealing from the whole block */
2551 free_pages
= move_freepages_block(zone
, page
, start_type
,
2554 * Determine how many pages are compatible with our allocation.
2555 * For movable allocation, it's the number of movable pages which
2556 * we just obtained. For other types it's a bit more tricky.
2558 if (start_type
== MIGRATE_MOVABLE
) {
2559 alike_pages
= movable_pages
;
2562 * If we are falling back a RECLAIMABLE or UNMOVABLE allocation
2563 * to MOVABLE pageblock, consider all non-movable pages as
2564 * compatible. If it's UNMOVABLE falling back to RECLAIMABLE or
2565 * vice versa, be conservative since we can't distinguish the
2566 * exact migratetype of non-movable pages.
2568 if (old_block_type
== MIGRATE_MOVABLE
)
2569 alike_pages
= pageblock_nr_pages
2570 - (free_pages
+ movable_pages
);
2575 /* moving whole block can fail due to zone boundary conditions */
2580 * If a sufficient number of pages in the block are either free or of
2581 * comparable migratability as our allocation, claim the whole block.
2583 if (free_pages
+ alike_pages
>= (1 << (pageblock_order
-1)) ||
2584 page_group_by_mobility_disabled
)
2585 set_pageblock_migratetype(page
, start_type
);
2590 move_to_free_list(page
, zone
, current_order
, start_type
);
2594 * Check whether there is a suitable fallback freepage with requested order.
2595 * If only_stealable is true, this function returns fallback_mt only if
2596 * we can steal other freepages all together. This would help to reduce
2597 * fragmentation due to mixed migratetype pages in one pageblock.
2599 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
2600 int migratetype
, bool only_stealable
, bool *can_steal
)
2605 if (area
->nr_free
== 0)
2610 fallback_mt
= fallbacks
[migratetype
][i
];
2611 if (fallback_mt
== MIGRATE_TYPES
)
2614 if (free_area_empty(area
, fallback_mt
))
2617 if (can_steal_fallback(order
, migratetype
))
2620 if (!only_stealable
)
2631 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2632 * there are no empty page blocks that contain a page with a suitable order
2634 static void reserve_highatomic_pageblock(struct page
*page
, struct zone
*zone
,
2635 unsigned int alloc_order
)
2638 unsigned long max_managed
, flags
;
2641 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2642 * Check is race-prone but harmless.
2644 max_managed
= (zone_managed_pages(zone
) / 100) + pageblock_nr_pages
;
2645 if (zone
->nr_reserved_highatomic
>= max_managed
)
2648 spin_lock_irqsave(&zone
->lock
, flags
);
2650 /* Recheck the nr_reserved_highatomic limit under the lock */
2651 if (zone
->nr_reserved_highatomic
>= max_managed
)
2655 mt
= get_pageblock_migratetype(page
);
2656 if (!is_migrate_highatomic(mt
) && !is_migrate_isolate(mt
)
2657 && !is_migrate_cma(mt
)) {
2658 zone
->nr_reserved_highatomic
+= pageblock_nr_pages
;
2659 set_pageblock_migratetype(page
, MIGRATE_HIGHATOMIC
);
2660 move_freepages_block(zone
, page
, MIGRATE_HIGHATOMIC
, NULL
);
2664 spin_unlock_irqrestore(&zone
->lock
, flags
);
2668 * Used when an allocation is about to fail under memory pressure. This
2669 * potentially hurts the reliability of high-order allocations when under
2670 * intense memory pressure but failed atomic allocations should be easier
2671 * to recover from than an OOM.
2673 * If @force is true, try to unreserve a pageblock even though highatomic
2674 * pageblock is exhausted.
2676 static bool unreserve_highatomic_pageblock(const struct alloc_context
*ac
,
2679 struct zonelist
*zonelist
= ac
->zonelist
;
2680 unsigned long flags
;
2687 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->highest_zoneidx
,
2690 * Preserve at least one pageblock unless memory pressure
2693 if (!force
&& zone
->nr_reserved_highatomic
<=
2697 spin_lock_irqsave(&zone
->lock
, flags
);
2698 for (order
= 0; order
< MAX_ORDER
; order
++) {
2699 struct free_area
*area
= &(zone
->free_area
[order
]);
2701 page
= get_page_from_free_area(area
, MIGRATE_HIGHATOMIC
);
2706 * In page freeing path, migratetype change is racy so
2707 * we can counter several free pages in a pageblock
2708 * in this loop althoug we changed the pageblock type
2709 * from highatomic to ac->migratetype. So we should
2710 * adjust the count once.
2712 if (is_migrate_highatomic_page(page
)) {
2714 * It should never happen but changes to
2715 * locking could inadvertently allow a per-cpu
2716 * drain to add pages to MIGRATE_HIGHATOMIC
2717 * while unreserving so be safe and watch for
2720 zone
->nr_reserved_highatomic
-= min(
2722 zone
->nr_reserved_highatomic
);
2726 * Convert to ac->migratetype and avoid the normal
2727 * pageblock stealing heuristics. Minimally, the caller
2728 * is doing the work and needs the pages. More
2729 * importantly, if the block was always converted to
2730 * MIGRATE_UNMOVABLE or another type then the number
2731 * of pageblocks that cannot be completely freed
2734 set_pageblock_migratetype(page
, ac
->migratetype
);
2735 ret
= move_freepages_block(zone
, page
, ac
->migratetype
,
2738 spin_unlock_irqrestore(&zone
->lock
, flags
);
2742 spin_unlock_irqrestore(&zone
->lock
, flags
);
2749 * Try finding a free buddy page on the fallback list and put it on the free
2750 * list of requested migratetype, possibly along with other pages from the same
2751 * block, depending on fragmentation avoidance heuristics. Returns true if
2752 * fallback was found so that __rmqueue_smallest() can grab it.
2754 * The use of signed ints for order and current_order is a deliberate
2755 * deviation from the rest of this file, to make the for loop
2756 * condition simpler.
2758 static __always_inline
bool
2759 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
,
2760 unsigned int alloc_flags
)
2762 struct free_area
*area
;
2764 int min_order
= order
;
2770 * Do not steal pages from freelists belonging to other pageblocks
2771 * i.e. orders < pageblock_order. If there are no local zones free,
2772 * the zonelists will be reiterated without ALLOC_NOFRAGMENT.
2774 if (alloc_flags
& ALLOC_NOFRAGMENT
)
2775 min_order
= pageblock_order
;
2778 * Find the largest available free page in the other list. This roughly
2779 * approximates finding the pageblock with the most free pages, which
2780 * would be too costly to do exactly.
2782 for (current_order
= MAX_ORDER
- 1; current_order
>= min_order
;
2784 area
= &(zone
->free_area
[current_order
]);
2785 fallback_mt
= find_suitable_fallback(area
, current_order
,
2786 start_migratetype
, false, &can_steal
);
2787 if (fallback_mt
== -1)
2791 * We cannot steal all free pages from the pageblock and the
2792 * requested migratetype is movable. In that case it's better to
2793 * steal and split the smallest available page instead of the
2794 * largest available page, because even if the next movable
2795 * allocation falls back into a different pageblock than this
2796 * one, it won't cause permanent fragmentation.
2798 if (!can_steal
&& start_migratetype
== MIGRATE_MOVABLE
2799 && current_order
> order
)
2808 for (current_order
= order
; current_order
< MAX_ORDER
;
2810 area
= &(zone
->free_area
[current_order
]);
2811 fallback_mt
= find_suitable_fallback(area
, current_order
,
2812 start_migratetype
, false, &can_steal
);
2813 if (fallback_mt
!= -1)
2818 * This should not happen - we already found a suitable fallback
2819 * when looking for the largest page.
2821 VM_BUG_ON(current_order
== MAX_ORDER
);
2824 page
= get_page_from_free_area(area
, fallback_mt
);
2826 steal_suitable_fallback(zone
, page
, alloc_flags
, start_migratetype
,
2829 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
2830 start_migratetype
, fallback_mt
);
2837 * Do the hard work of removing an element from the buddy allocator.
2838 * Call me with the zone->lock already held.
2840 static __always_inline
struct page
*
2841 __rmqueue(struct zone
*zone
, unsigned int order
, int migratetype
,
2842 unsigned int alloc_flags
)
2848 * Balance movable allocations between regular and CMA areas by
2849 * allocating from CMA when over half of the zone's free memory
2850 * is in the CMA area.
2852 if (alloc_flags
& ALLOC_CMA
&&
2853 zone_page_state(zone
, NR_FREE_CMA_PAGES
) >
2854 zone_page_state(zone
, NR_FREE_PAGES
) / 2) {
2855 page
= __rmqueue_cma_fallback(zone
, order
);
2861 page
= __rmqueue_smallest(zone
, order
, migratetype
);
2862 if (unlikely(!page
)) {
2863 if (alloc_flags
& ALLOC_CMA
)
2864 page
= __rmqueue_cma_fallback(zone
, order
);
2866 if (!page
&& __rmqueue_fallback(zone
, order
, migratetype
,
2871 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2876 * Obtain a specified number of elements from the buddy allocator, all under
2877 * a single hold of the lock, for efficiency. Add them to the supplied list.
2878 * Returns the number of new pages which were placed at *list.
2880 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
2881 unsigned long count
, struct list_head
*list
,
2882 int migratetype
, unsigned int alloc_flags
)
2886 spin_lock(&zone
->lock
);
2887 for (i
= 0; i
< count
; ++i
) {
2888 struct page
*page
= __rmqueue(zone
, order
, migratetype
,
2890 if (unlikely(page
== NULL
))
2893 if (unlikely(check_pcp_refill(page
)))
2897 * Split buddy pages returned by expand() are received here in
2898 * physical page order. The page is added to the tail of
2899 * caller's list. From the callers perspective, the linked list
2900 * is ordered by page number under some conditions. This is
2901 * useful for IO devices that can forward direction from the
2902 * head, thus also in the physical page order. This is useful
2903 * for IO devices that can merge IO requests if the physical
2904 * pages are ordered properly.
2906 list_add_tail(&page
->lru
, list
);
2908 if (is_migrate_cma(get_pcppage_migratetype(page
)))
2909 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
2914 * i pages were removed from the buddy list even if some leak due
2915 * to check_pcp_refill failing so adjust NR_FREE_PAGES based
2916 * on i. Do not confuse with 'alloced' which is the number of
2917 * pages added to the pcp list.
2919 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
2920 spin_unlock(&zone
->lock
);
2926 * Called from the vmstat counter updater to drain pagesets of this
2927 * currently executing processor on remote nodes after they have
2930 * Note that this function must be called with the thread pinned to
2931 * a single processor.
2933 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
2935 unsigned long flags
;
2936 int to_drain
, batch
;
2938 local_irq_save(flags
);
2939 batch
= READ_ONCE(pcp
->batch
);
2940 to_drain
= min(pcp
->count
, batch
);
2942 free_pcppages_bulk(zone
, to_drain
, pcp
);
2943 local_irq_restore(flags
);
2948 * Drain pcplists of the indicated processor and zone.
2950 * The processor must either be the current processor and the
2951 * thread pinned to the current processor or a processor that
2954 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
2956 unsigned long flags
;
2957 struct per_cpu_pageset
*pset
;
2958 struct per_cpu_pages
*pcp
;
2960 local_irq_save(flags
);
2961 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
2965 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
2966 local_irq_restore(flags
);
2970 * Drain pcplists of all zones on the indicated processor.
2972 * The processor must either be the current processor and the
2973 * thread pinned to the current processor or a processor that
2976 static void drain_pages(unsigned int cpu
)
2980 for_each_populated_zone(zone
) {
2981 drain_pages_zone(cpu
, zone
);
2986 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2988 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2989 * the single zone's pages.
2991 void drain_local_pages(struct zone
*zone
)
2993 int cpu
= smp_processor_id();
2996 drain_pages_zone(cpu
, zone
);
3001 static void drain_local_pages_wq(struct work_struct
*work
)
3003 struct pcpu_drain
*drain
;
3005 drain
= container_of(work
, struct pcpu_drain
, work
);
3008 * drain_all_pages doesn't use proper cpu hotplug protection so
3009 * we can race with cpu offline when the WQ can move this from
3010 * a cpu pinned worker to an unbound one. We can operate on a different
3011 * cpu which is allright but we also have to make sure to not move to
3015 drain_local_pages(drain
->zone
);
3020 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
3022 * When zone parameter is non-NULL, spill just the single zone's pages.
3024 * Note that this can be extremely slow as the draining happens in a workqueue.
3026 void drain_all_pages(struct zone
*zone
)
3031 * Allocate in the BSS so we wont require allocation in
3032 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
3034 static cpumask_t cpus_with_pcps
;
3037 * Make sure nobody triggers this path before mm_percpu_wq is fully
3040 if (WARN_ON_ONCE(!mm_percpu_wq
))
3044 * Do not drain if one is already in progress unless it's specific to
3045 * a zone. Such callers are primarily CMA and memory hotplug and need
3046 * the drain to be complete when the call returns.
3048 if (unlikely(!mutex_trylock(&pcpu_drain_mutex
))) {
3051 mutex_lock(&pcpu_drain_mutex
);
3055 * We don't care about racing with CPU hotplug event
3056 * as offline notification will cause the notified
3057 * cpu to drain that CPU pcps and on_each_cpu_mask
3058 * disables preemption as part of its processing
3060 for_each_online_cpu(cpu
) {
3061 struct per_cpu_pageset
*pcp
;
3063 bool has_pcps
= false;
3066 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
3070 for_each_populated_zone(z
) {
3071 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
3072 if (pcp
->pcp
.count
) {
3080 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
3082 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
3085 for_each_cpu(cpu
, &cpus_with_pcps
) {
3086 struct pcpu_drain
*drain
= per_cpu_ptr(&pcpu_drain
, cpu
);
3089 INIT_WORK(&drain
->work
, drain_local_pages_wq
);
3090 queue_work_on(cpu
, mm_percpu_wq
, &drain
->work
);
3092 for_each_cpu(cpu
, &cpus_with_pcps
)
3093 flush_work(&per_cpu_ptr(&pcpu_drain
, cpu
)->work
);
3095 mutex_unlock(&pcpu_drain_mutex
);
3098 #ifdef CONFIG_HIBERNATION
3101 * Touch the watchdog for every WD_PAGE_COUNT pages.
3103 #define WD_PAGE_COUNT (128*1024)
3105 void mark_free_pages(struct zone
*zone
)
3107 unsigned long pfn
, max_zone_pfn
, page_count
= WD_PAGE_COUNT
;
3108 unsigned long flags
;
3109 unsigned int order
, t
;
3112 if (zone_is_empty(zone
))
3115 spin_lock_irqsave(&zone
->lock
, flags
);
3117 max_zone_pfn
= zone_end_pfn(zone
);
3118 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
3119 if (pfn_valid(pfn
)) {
3120 page
= pfn_to_page(pfn
);
3122 if (!--page_count
) {
3123 touch_nmi_watchdog();
3124 page_count
= WD_PAGE_COUNT
;
3127 if (page_zone(page
) != zone
)
3130 if (!swsusp_page_is_forbidden(page
))
3131 swsusp_unset_page_free(page
);
3134 for_each_migratetype_order(order
, t
) {
3135 list_for_each_entry(page
,
3136 &zone
->free_area
[order
].free_list
[t
], lru
) {
3139 pfn
= page_to_pfn(page
);
3140 for (i
= 0; i
< (1UL << order
); i
++) {
3141 if (!--page_count
) {
3142 touch_nmi_watchdog();
3143 page_count
= WD_PAGE_COUNT
;
3145 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
3149 spin_unlock_irqrestore(&zone
->lock
, flags
);
3151 #endif /* CONFIG_PM */
3153 static bool free_unref_page_prepare(struct page
*page
, unsigned long pfn
)
3157 if (!free_pcp_prepare(page
))
3160 migratetype
= get_pfnblock_migratetype(page
, pfn
);
3161 set_pcppage_migratetype(page
, migratetype
);
3165 static void free_unref_page_commit(struct page
*page
, unsigned long pfn
)
3167 struct zone
*zone
= page_zone(page
);
3168 struct per_cpu_pages
*pcp
;
3171 migratetype
= get_pcppage_migratetype(page
);
3172 __count_vm_event(PGFREE
);
3175 * We only track unmovable, reclaimable and movable on pcp lists.
3176 * Free ISOLATE pages back to the allocator because they are being
3177 * offlined but treat HIGHATOMIC as movable pages so we can get those
3178 * areas back if necessary. Otherwise, we may have to free
3179 * excessively into the page allocator
3181 if (migratetype
>= MIGRATE_PCPTYPES
) {
3182 if (unlikely(is_migrate_isolate(migratetype
))) {
3183 free_one_page(zone
, page
, pfn
, 0, migratetype
,
3187 migratetype
= MIGRATE_MOVABLE
;
3190 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
3191 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
3193 if (pcp
->count
>= pcp
->high
) {
3194 unsigned long batch
= READ_ONCE(pcp
->batch
);
3195 free_pcppages_bulk(zone
, batch
, pcp
);
3200 * Free a 0-order page
3202 void free_unref_page(struct page
*page
)
3204 unsigned long flags
;
3205 unsigned long pfn
= page_to_pfn(page
);
3207 if (!free_unref_page_prepare(page
, pfn
))
3210 local_irq_save(flags
);
3211 free_unref_page_commit(page
, pfn
);
3212 local_irq_restore(flags
);
3216 * Free a list of 0-order pages
3218 void free_unref_page_list(struct list_head
*list
)
3220 struct page
*page
, *next
;
3221 unsigned long flags
, pfn
;
3222 int batch_count
= 0;
3224 /* Prepare pages for freeing */
3225 list_for_each_entry_safe(page
, next
, list
, lru
) {
3226 pfn
= page_to_pfn(page
);
3227 if (!free_unref_page_prepare(page
, pfn
))
3228 list_del(&page
->lru
);
3229 set_page_private(page
, pfn
);
3232 local_irq_save(flags
);
3233 list_for_each_entry_safe(page
, next
, list
, lru
) {
3234 unsigned long pfn
= page_private(page
);
3236 set_page_private(page
, 0);
3237 trace_mm_page_free_batched(page
);
3238 free_unref_page_commit(page
, pfn
);
3241 * Guard against excessive IRQ disabled times when we get
3242 * a large list of pages to free.
3244 if (++batch_count
== SWAP_CLUSTER_MAX
) {
3245 local_irq_restore(flags
);
3247 local_irq_save(flags
);
3250 local_irq_restore(flags
);
3254 * split_page takes a non-compound higher-order page, and splits it into
3255 * n (1<<order) sub-pages: page[0..n]
3256 * Each sub-page must be freed individually.
3258 * Note: this is probably too low level an operation for use in drivers.
3259 * Please consult with lkml before using this in your driver.
3261 void split_page(struct page
*page
, unsigned int order
)
3265 VM_BUG_ON_PAGE(PageCompound(page
), page
);
3266 VM_BUG_ON_PAGE(!page_count(page
), page
);
3268 for (i
= 1; i
< (1 << order
); i
++)
3269 set_page_refcounted(page
+ i
);
3270 split_page_owner(page
, 1 << order
);
3272 EXPORT_SYMBOL_GPL(split_page
);
3274 int __isolate_free_page(struct page
*page
, unsigned int order
)
3276 unsigned long watermark
;
3280 BUG_ON(!PageBuddy(page
));
3282 zone
= page_zone(page
);
3283 mt
= get_pageblock_migratetype(page
);
3285 if (!is_migrate_isolate(mt
)) {
3287 * Obey watermarks as if the page was being allocated. We can
3288 * emulate a high-order watermark check with a raised order-0
3289 * watermark, because we already know our high-order page
3292 watermark
= zone
->_watermark
[WMARK_MIN
] + (1UL << order
);
3293 if (!zone_watermark_ok(zone
, 0, watermark
, 0, ALLOC_CMA
))
3296 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
3299 /* Remove page from free list */
3301 del_page_from_free_list(page
, zone
, order
);
3304 * Set the pageblock if the isolated page is at least half of a
3307 if (order
>= pageblock_order
- 1) {
3308 struct page
*endpage
= page
+ (1 << order
) - 1;
3309 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
3310 int mt
= get_pageblock_migratetype(page
);
3311 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
)
3312 && !is_migrate_highatomic(mt
))
3313 set_pageblock_migratetype(page
,
3319 return 1UL << order
;
3323 * __putback_isolated_page - Return a now-isolated page back where we got it
3324 * @page: Page that was isolated
3325 * @order: Order of the isolated page
3326 * @mt: The page's pageblock's migratetype
3328 * This function is meant to return a page pulled from the free lists via
3329 * __isolate_free_page back to the free lists they were pulled from.
3331 void __putback_isolated_page(struct page
*page
, unsigned int order
, int mt
)
3333 struct zone
*zone
= page_zone(page
);
3335 /* zone lock should be held when this function is called */
3336 lockdep_assert_held(&zone
->lock
);
3338 /* Return isolated page to tail of freelist. */
3339 __free_one_page(page
, page_to_pfn(page
), zone
, order
, mt
,
3340 FPI_SKIP_REPORT_NOTIFY
| FPI_TO_TAIL
);
3344 * Update NUMA hit/miss statistics
3346 * Must be called with interrupts disabled.
3348 static inline void zone_statistics(struct zone
*preferred_zone
, struct zone
*z
)
3351 enum numa_stat_item local_stat
= NUMA_LOCAL
;
3353 /* skip numa counters update if numa stats is disabled */
3354 if (!static_branch_likely(&vm_numa_stat_key
))
3357 if (zone_to_nid(z
) != numa_node_id())
3358 local_stat
= NUMA_OTHER
;
3360 if (zone_to_nid(z
) == zone_to_nid(preferred_zone
))
3361 __inc_numa_state(z
, NUMA_HIT
);
3363 __inc_numa_state(z
, NUMA_MISS
);
3364 __inc_numa_state(preferred_zone
, NUMA_FOREIGN
);
3366 __inc_numa_state(z
, local_stat
);
3370 /* Remove page from the per-cpu list, caller must protect the list */
3371 static struct page
*__rmqueue_pcplist(struct zone
*zone
, int migratetype
,
3372 unsigned int alloc_flags
,
3373 struct per_cpu_pages
*pcp
,
3374 struct list_head
*list
)
3379 if (list_empty(list
)) {
3380 pcp
->count
+= rmqueue_bulk(zone
, 0,
3382 migratetype
, alloc_flags
);
3383 if (unlikely(list_empty(list
)))
3387 page
= list_first_entry(list
, struct page
, lru
);
3388 list_del(&page
->lru
);
3390 } while (check_new_pcp(page
));
3395 /* Lock and remove page from the per-cpu list */
3396 static struct page
*rmqueue_pcplist(struct zone
*preferred_zone
,
3397 struct zone
*zone
, gfp_t gfp_flags
,
3398 int migratetype
, unsigned int alloc_flags
)
3400 struct per_cpu_pages
*pcp
;
3401 struct list_head
*list
;
3403 unsigned long flags
;
3405 local_irq_save(flags
);
3406 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
3407 list
= &pcp
->lists
[migratetype
];
3408 page
= __rmqueue_pcplist(zone
, migratetype
, alloc_flags
, pcp
, list
);
3410 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1);
3411 zone_statistics(preferred_zone
, zone
);
3413 local_irq_restore(flags
);
3418 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
3421 struct page
*rmqueue(struct zone
*preferred_zone
,
3422 struct zone
*zone
, unsigned int order
,
3423 gfp_t gfp_flags
, unsigned int alloc_flags
,
3426 unsigned long flags
;
3429 if (likely(order
== 0)) {
3431 * MIGRATE_MOVABLE pcplist could have the pages on CMA area and
3432 * we need to skip it when CMA area isn't allowed.
3434 if (!IS_ENABLED(CONFIG_CMA
) || alloc_flags
& ALLOC_CMA
||
3435 migratetype
!= MIGRATE_MOVABLE
) {
3436 page
= rmqueue_pcplist(preferred_zone
, zone
, gfp_flags
,
3437 migratetype
, alloc_flags
);
3443 * We most definitely don't want callers attempting to
3444 * allocate greater than order-1 page units with __GFP_NOFAIL.
3446 WARN_ON_ONCE((gfp_flags
& __GFP_NOFAIL
) && (order
> 1));
3447 spin_lock_irqsave(&zone
->lock
, flags
);
3452 * order-0 request can reach here when the pcplist is skipped
3453 * due to non-CMA allocation context. HIGHATOMIC area is
3454 * reserved for high-order atomic allocation, so order-0
3455 * request should skip it.
3457 if (order
> 0 && alloc_flags
& ALLOC_HARDER
) {
3458 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
3460 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
3463 page
= __rmqueue(zone
, order
, migratetype
, alloc_flags
);
3464 } while (page
&& check_new_pages(page
, order
));
3465 spin_unlock(&zone
->lock
);
3468 __mod_zone_freepage_state(zone
, -(1 << order
),
3469 get_pcppage_migratetype(page
));
3471 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1 << order
);
3472 zone_statistics(preferred_zone
, zone
);
3473 local_irq_restore(flags
);
3476 /* Separate test+clear to avoid unnecessary atomics */
3477 if (test_bit(ZONE_BOOSTED_WATERMARK
, &zone
->flags
)) {
3478 clear_bit(ZONE_BOOSTED_WATERMARK
, &zone
->flags
);
3479 wakeup_kswapd(zone
, 0, 0, zone_idx(zone
));
3482 VM_BUG_ON_PAGE(page
&& bad_range(zone
, page
), page
);
3486 local_irq_restore(flags
);
3490 #ifdef CONFIG_FAIL_PAGE_ALLOC
3493 struct fault_attr attr
;
3495 bool ignore_gfp_highmem
;
3496 bool ignore_gfp_reclaim
;
3498 } fail_page_alloc
= {
3499 .attr
= FAULT_ATTR_INITIALIZER
,
3500 .ignore_gfp_reclaim
= true,
3501 .ignore_gfp_highmem
= true,
3505 static int __init
setup_fail_page_alloc(char *str
)
3507 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
3509 __setup("fail_page_alloc=", setup_fail_page_alloc
);
3511 static bool __should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
3513 if (order
< fail_page_alloc
.min_order
)
3515 if (gfp_mask
& __GFP_NOFAIL
)
3517 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
3519 if (fail_page_alloc
.ignore_gfp_reclaim
&&
3520 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
3523 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
3526 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
3528 static int __init
fail_page_alloc_debugfs(void)
3530 umode_t mode
= S_IFREG
| 0600;
3533 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
3534 &fail_page_alloc
.attr
);
3536 debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
3537 &fail_page_alloc
.ignore_gfp_reclaim
);
3538 debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
3539 &fail_page_alloc
.ignore_gfp_highmem
);
3540 debugfs_create_u32("min-order", mode
, dir
, &fail_page_alloc
.min_order
);
3545 late_initcall(fail_page_alloc_debugfs
);
3547 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
3549 #else /* CONFIG_FAIL_PAGE_ALLOC */
3551 static inline bool __should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
3556 #endif /* CONFIG_FAIL_PAGE_ALLOC */
3558 noinline
bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
3560 return __should_fail_alloc_page(gfp_mask
, order
);
3562 ALLOW_ERROR_INJECTION(should_fail_alloc_page
, TRUE
);
3564 static inline long __zone_watermark_unusable_free(struct zone
*z
,
3565 unsigned int order
, unsigned int alloc_flags
)
3567 const bool alloc_harder
= (alloc_flags
& (ALLOC_HARDER
|ALLOC_OOM
));
3568 long unusable_free
= (1 << order
) - 1;
3571 * If the caller does not have rights to ALLOC_HARDER then subtract
3572 * the high-atomic reserves. This will over-estimate the size of the
3573 * atomic reserve but it avoids a search.
3575 if (likely(!alloc_harder
))
3576 unusable_free
+= z
->nr_reserved_highatomic
;
3579 /* If allocation can't use CMA areas don't use free CMA pages */
3580 if (!(alloc_flags
& ALLOC_CMA
))
3581 unusable_free
+= zone_page_state(z
, NR_FREE_CMA_PAGES
);
3584 return unusable_free
;
3588 * Return true if free base pages are above 'mark'. For high-order checks it
3589 * will return true of the order-0 watermark is reached and there is at least
3590 * one free page of a suitable size. Checking now avoids taking the zone lock
3591 * to check in the allocation paths if no pages are free.
3593 bool __zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
3594 int highest_zoneidx
, unsigned int alloc_flags
,
3599 const bool alloc_harder
= (alloc_flags
& (ALLOC_HARDER
|ALLOC_OOM
));
3601 /* free_pages may go negative - that's OK */
3602 free_pages
-= __zone_watermark_unusable_free(z
, order
, alloc_flags
);
3604 if (alloc_flags
& ALLOC_HIGH
)
3607 if (unlikely(alloc_harder
)) {
3609 * OOM victims can try even harder than normal ALLOC_HARDER
3610 * users on the grounds that it's definitely going to be in
3611 * the exit path shortly and free memory. Any allocation it
3612 * makes during the free path will be small and short-lived.
3614 if (alloc_flags
& ALLOC_OOM
)
3621 * Check watermarks for an order-0 allocation request. If these
3622 * are not met, then a high-order request also cannot go ahead
3623 * even if a suitable page happened to be free.
3625 if (free_pages
<= min
+ z
->lowmem_reserve
[highest_zoneidx
])
3628 /* If this is an order-0 request then the watermark is fine */
3632 /* For a high-order request, check at least one suitable page is free */
3633 for (o
= order
; o
< MAX_ORDER
; o
++) {
3634 struct free_area
*area
= &z
->free_area
[o
];
3640 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
3641 if (!free_area_empty(area
, mt
))
3646 if ((alloc_flags
& ALLOC_CMA
) &&
3647 !free_area_empty(area
, MIGRATE_CMA
)) {
3651 if (alloc_harder
&& !free_area_empty(area
, MIGRATE_HIGHATOMIC
))
3657 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
3658 int highest_zoneidx
, unsigned int alloc_flags
)
3660 return __zone_watermark_ok(z
, order
, mark
, highest_zoneidx
, alloc_flags
,
3661 zone_page_state(z
, NR_FREE_PAGES
));
3664 static inline bool zone_watermark_fast(struct zone
*z
, unsigned int order
,
3665 unsigned long mark
, int highest_zoneidx
,
3666 unsigned int alloc_flags
, gfp_t gfp_mask
)
3670 free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
3673 * Fast check for order-0 only. If this fails then the reserves
3674 * need to be calculated.
3679 fast_free
= free_pages
;
3680 fast_free
-= __zone_watermark_unusable_free(z
, 0, alloc_flags
);
3681 if (fast_free
> mark
+ z
->lowmem_reserve
[highest_zoneidx
])
3685 if (__zone_watermark_ok(z
, order
, mark
, highest_zoneidx
, alloc_flags
,
3689 * Ignore watermark boosting for GFP_ATOMIC order-0 allocations
3690 * when checking the min watermark. The min watermark is the
3691 * point where boosting is ignored so that kswapd is woken up
3692 * when below the low watermark.
3694 if (unlikely(!order
&& (gfp_mask
& __GFP_ATOMIC
) && z
->watermark_boost
3695 && ((alloc_flags
& ALLOC_WMARK_MASK
) == WMARK_MIN
))) {
3696 mark
= z
->_watermark
[WMARK_MIN
];
3697 return __zone_watermark_ok(z
, order
, mark
, highest_zoneidx
,
3698 alloc_flags
, free_pages
);
3704 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
3705 unsigned long mark
, int highest_zoneidx
)
3707 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
3709 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
3710 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
3712 return __zone_watermark_ok(z
, order
, mark
, highest_zoneidx
, 0,
3717 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
3719 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <=
3720 node_reclaim_distance
;
3722 #else /* CONFIG_NUMA */
3723 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
3727 #endif /* CONFIG_NUMA */
3730 * The restriction on ZONE_DMA32 as being a suitable zone to use to avoid
3731 * fragmentation is subtle. If the preferred zone was HIGHMEM then
3732 * premature use of a lower zone may cause lowmem pressure problems that
3733 * are worse than fragmentation. If the next zone is ZONE_DMA then it is
3734 * probably too small. It only makes sense to spread allocations to avoid
3735 * fragmentation between the Normal and DMA32 zones.
3737 static inline unsigned int
3738 alloc_flags_nofragment(struct zone
*zone
, gfp_t gfp_mask
)
3740 unsigned int alloc_flags
;
3743 * __GFP_KSWAPD_RECLAIM is assumed to be the same as ALLOC_KSWAPD
3746 alloc_flags
= (__force
int) (gfp_mask
& __GFP_KSWAPD_RECLAIM
);
3748 #ifdef CONFIG_ZONE_DMA32
3752 if (zone_idx(zone
) != ZONE_NORMAL
)
3756 * If ZONE_DMA32 exists, assume it is the one after ZONE_NORMAL and
3757 * the pointer is within zone->zone_pgdat->node_zones[]. Also assume
3758 * on UMA that if Normal is populated then so is DMA32.
3760 BUILD_BUG_ON(ZONE_NORMAL
- ZONE_DMA32
!= 1);
3761 if (nr_online_nodes
> 1 && !populated_zone(--zone
))
3764 alloc_flags
|= ALLOC_NOFRAGMENT
;
3765 #endif /* CONFIG_ZONE_DMA32 */
3769 static inline unsigned int current_alloc_flags(gfp_t gfp_mask
,
3770 unsigned int alloc_flags
)
3773 unsigned int pflags
= current
->flags
;
3775 if (!(pflags
& PF_MEMALLOC_NOCMA
) &&
3776 gfp_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
3777 alloc_flags
|= ALLOC_CMA
;
3784 * get_page_from_freelist goes through the zonelist trying to allocate
3787 static struct page
*
3788 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
3789 const struct alloc_context
*ac
)
3793 struct pglist_data
*last_pgdat_dirty_limit
= NULL
;
3798 * Scan zonelist, looking for a zone with enough free.
3799 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
3801 no_fallback
= alloc_flags
& ALLOC_NOFRAGMENT
;
3802 z
= ac
->preferred_zoneref
;
3803 for_next_zone_zonelist_nodemask(zone
, z
, ac
->highest_zoneidx
,
3808 if (cpusets_enabled() &&
3809 (alloc_flags
& ALLOC_CPUSET
) &&
3810 !__cpuset_zone_allowed(zone
, gfp_mask
))
3813 * When allocating a page cache page for writing, we
3814 * want to get it from a node that is within its dirty
3815 * limit, such that no single node holds more than its
3816 * proportional share of globally allowed dirty pages.
3817 * The dirty limits take into account the node's
3818 * lowmem reserves and high watermark so that kswapd
3819 * should be able to balance it without having to
3820 * write pages from its LRU list.
3822 * XXX: For now, allow allocations to potentially
3823 * exceed the per-node dirty limit in the slowpath
3824 * (spread_dirty_pages unset) before going into reclaim,
3825 * which is important when on a NUMA setup the allowed
3826 * nodes are together not big enough to reach the
3827 * global limit. The proper fix for these situations
3828 * will require awareness of nodes in the
3829 * dirty-throttling and the flusher threads.
3831 if (ac
->spread_dirty_pages
) {
3832 if (last_pgdat_dirty_limit
== zone
->zone_pgdat
)
3835 if (!node_dirty_ok(zone
->zone_pgdat
)) {
3836 last_pgdat_dirty_limit
= zone
->zone_pgdat
;
3841 if (no_fallback
&& nr_online_nodes
> 1 &&
3842 zone
!= ac
->preferred_zoneref
->zone
) {
3846 * If moving to a remote node, retry but allow
3847 * fragmenting fallbacks. Locality is more important
3848 * than fragmentation avoidance.
3850 local_nid
= zone_to_nid(ac
->preferred_zoneref
->zone
);
3851 if (zone_to_nid(zone
) != local_nid
) {
3852 alloc_flags
&= ~ALLOC_NOFRAGMENT
;
3857 mark
= wmark_pages(zone
, alloc_flags
& ALLOC_WMARK_MASK
);
3858 if (!zone_watermark_fast(zone
, order
, mark
,
3859 ac
->highest_zoneidx
, alloc_flags
,
3863 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
3865 * Watermark failed for this zone, but see if we can
3866 * grow this zone if it contains deferred pages.
3868 if (static_branch_unlikely(&deferred_pages
)) {
3869 if (_deferred_grow_zone(zone
, order
))
3873 /* Checked here to keep the fast path fast */
3874 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
3875 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
3878 if (node_reclaim_mode
== 0 ||
3879 !zone_allows_reclaim(ac
->preferred_zoneref
->zone
, zone
))
3882 ret
= node_reclaim(zone
->zone_pgdat
, gfp_mask
, order
);
3884 case NODE_RECLAIM_NOSCAN
:
3887 case NODE_RECLAIM_FULL
:
3888 /* scanned but unreclaimable */
3891 /* did we reclaim enough */
3892 if (zone_watermark_ok(zone
, order
, mark
,
3893 ac
->highest_zoneidx
, alloc_flags
))
3901 page
= rmqueue(ac
->preferred_zoneref
->zone
, zone
, order
,
3902 gfp_mask
, alloc_flags
, ac
->migratetype
);
3904 prep_new_page(page
, order
, gfp_mask
, alloc_flags
);
3907 * If this is a high-order atomic allocation then check
3908 * if the pageblock should be reserved for the future
3910 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
3911 reserve_highatomic_pageblock(page
, zone
, order
);
3915 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
3916 /* Try again if zone has deferred pages */
3917 if (static_branch_unlikely(&deferred_pages
)) {
3918 if (_deferred_grow_zone(zone
, order
))
3926 * It's possible on a UMA machine to get through all zones that are
3927 * fragmented. If avoiding fragmentation, reset and try again.
3930 alloc_flags
&= ~ALLOC_NOFRAGMENT
;
3937 static void warn_alloc_show_mem(gfp_t gfp_mask
, nodemask_t
*nodemask
)
3939 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
3942 * This documents exceptions given to allocations in certain
3943 * contexts that are allowed to allocate outside current's set
3946 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3947 if (tsk_is_oom_victim(current
) ||
3948 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
3949 filter
&= ~SHOW_MEM_FILTER_NODES
;
3950 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
3951 filter
&= ~SHOW_MEM_FILTER_NODES
;
3953 show_mem(filter
, nodemask
);
3956 void warn_alloc(gfp_t gfp_mask
, nodemask_t
*nodemask
, const char *fmt
, ...)
3958 struct va_format vaf
;
3960 static DEFINE_RATELIMIT_STATE(nopage_rs
, 10*HZ
, 1);
3962 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
))
3965 va_start(args
, fmt
);
3968 pr_warn("%s: %pV, mode:%#x(%pGg), nodemask=%*pbl",
3969 current
->comm
, &vaf
, gfp_mask
, &gfp_mask
,
3970 nodemask_pr_args(nodemask
));
3973 cpuset_print_current_mems_allowed();
3976 warn_alloc_show_mem(gfp_mask
, nodemask
);
3979 static inline struct page
*
3980 __alloc_pages_cpuset_fallback(gfp_t gfp_mask
, unsigned int order
,
3981 unsigned int alloc_flags
,
3982 const struct alloc_context
*ac
)
3986 page
= get_page_from_freelist(gfp_mask
, order
,
3987 alloc_flags
|ALLOC_CPUSET
, ac
);
3989 * fallback to ignore cpuset restriction if our nodes
3993 page
= get_page_from_freelist(gfp_mask
, order
,
3999 static inline struct page
*
4000 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
4001 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
4003 struct oom_control oc
= {
4004 .zonelist
= ac
->zonelist
,
4005 .nodemask
= ac
->nodemask
,
4007 .gfp_mask
= gfp_mask
,
4012 *did_some_progress
= 0;
4015 * Acquire the oom lock. If that fails, somebody else is
4016 * making progress for us.
4018 if (!mutex_trylock(&oom_lock
)) {
4019 *did_some_progress
= 1;
4020 schedule_timeout_uninterruptible(1);
4025 * Go through the zonelist yet one more time, keep very high watermark
4026 * here, this is only to catch a parallel oom killing, we must fail if
4027 * we're still under heavy pressure. But make sure that this reclaim
4028 * attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY
4029 * allocation which will never fail due to oom_lock already held.
4031 page
= get_page_from_freelist((gfp_mask
| __GFP_HARDWALL
) &
4032 ~__GFP_DIRECT_RECLAIM
, order
,
4033 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
4037 /* Coredumps can quickly deplete all memory reserves */
4038 if (current
->flags
& PF_DUMPCORE
)
4040 /* The OOM killer will not help higher order allocs */
4041 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
4044 * We have already exhausted all our reclaim opportunities without any
4045 * success so it is time to admit defeat. We will skip the OOM killer
4046 * because it is very likely that the caller has a more reasonable
4047 * fallback than shooting a random task.
4049 * The OOM killer may not free memory on a specific node.
4051 if (gfp_mask
& (__GFP_RETRY_MAYFAIL
| __GFP_THISNODE
))
4053 /* The OOM killer does not needlessly kill tasks for lowmem */
4054 if (ac
->highest_zoneidx
< ZONE_NORMAL
)
4056 if (pm_suspended_storage())
4059 * XXX: GFP_NOFS allocations should rather fail than rely on
4060 * other request to make a forward progress.
4061 * We are in an unfortunate situation where out_of_memory cannot
4062 * do much for this context but let's try it to at least get
4063 * access to memory reserved if the current task is killed (see
4064 * out_of_memory). Once filesystems are ready to handle allocation
4065 * failures more gracefully we should just bail out here.
4068 /* Exhausted what can be done so it's blame time */
4069 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
4070 *did_some_progress
= 1;
4073 * Help non-failing allocations by giving them access to memory
4076 if (gfp_mask
& __GFP_NOFAIL
)
4077 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
,
4078 ALLOC_NO_WATERMARKS
, ac
);
4081 mutex_unlock(&oom_lock
);
4086 * Maximum number of compaction retries wit a progress before OOM
4087 * killer is consider as the only way to move forward.
4089 #define MAX_COMPACT_RETRIES 16
4091 #ifdef CONFIG_COMPACTION
4092 /* Try memory compaction for high-order allocations before reclaim */
4093 static struct page
*
4094 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
4095 unsigned int alloc_flags
, const struct alloc_context
*ac
,
4096 enum compact_priority prio
, enum compact_result
*compact_result
)
4098 struct page
*page
= NULL
;
4099 unsigned long pflags
;
4100 unsigned int noreclaim_flag
;
4105 psi_memstall_enter(&pflags
);
4106 noreclaim_flag
= memalloc_noreclaim_save();
4108 *compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
4111 memalloc_noreclaim_restore(noreclaim_flag
);
4112 psi_memstall_leave(&pflags
);
4115 * At least in one zone compaction wasn't deferred or skipped, so let's
4116 * count a compaction stall
4118 count_vm_event(COMPACTSTALL
);
4120 /* Prep a captured page if available */
4122 prep_new_page(page
, order
, gfp_mask
, alloc_flags
);
4124 /* Try get a page from the freelist if available */
4126 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
4129 struct zone
*zone
= page_zone(page
);
4131 zone
->compact_blockskip_flush
= false;
4132 compaction_defer_reset(zone
, order
, true);
4133 count_vm_event(COMPACTSUCCESS
);
4138 * It's bad if compaction run occurs and fails. The most likely reason
4139 * is that pages exist, but not enough to satisfy watermarks.
4141 count_vm_event(COMPACTFAIL
);
4149 should_compact_retry(struct alloc_context
*ac
, int order
, int alloc_flags
,
4150 enum compact_result compact_result
,
4151 enum compact_priority
*compact_priority
,
4152 int *compaction_retries
)
4154 int max_retries
= MAX_COMPACT_RETRIES
;
4157 int retries
= *compaction_retries
;
4158 enum compact_priority priority
= *compact_priority
;
4163 if (compaction_made_progress(compact_result
))
4164 (*compaction_retries
)++;
4167 * compaction considers all the zone as desperately out of memory
4168 * so it doesn't really make much sense to retry except when the
4169 * failure could be caused by insufficient priority
4171 if (compaction_failed(compact_result
))
4172 goto check_priority
;
4175 * compaction was skipped because there are not enough order-0 pages
4176 * to work with, so we retry only if it looks like reclaim can help.
4178 if (compaction_needs_reclaim(compact_result
)) {
4179 ret
= compaction_zonelist_suitable(ac
, order
, alloc_flags
);
4184 * make sure the compaction wasn't deferred or didn't bail out early
4185 * due to locks contention before we declare that we should give up.
4186 * But the next retry should use a higher priority if allowed, so
4187 * we don't just keep bailing out endlessly.
4189 if (compaction_withdrawn(compact_result
)) {
4190 goto check_priority
;
4194 * !costly requests are much more important than __GFP_RETRY_MAYFAIL
4195 * costly ones because they are de facto nofail and invoke OOM
4196 * killer to move on while costly can fail and users are ready
4197 * to cope with that. 1/4 retries is rather arbitrary but we
4198 * would need much more detailed feedback from compaction to
4199 * make a better decision.
4201 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
4203 if (*compaction_retries
<= max_retries
) {
4209 * Make sure there are attempts at the highest priority if we exhausted
4210 * all retries or failed at the lower priorities.
4213 min_priority
= (order
> PAGE_ALLOC_COSTLY_ORDER
) ?
4214 MIN_COMPACT_COSTLY_PRIORITY
: MIN_COMPACT_PRIORITY
;
4216 if (*compact_priority
> min_priority
) {
4217 (*compact_priority
)--;
4218 *compaction_retries
= 0;
4222 trace_compact_retry(order
, priority
, compact_result
, retries
, max_retries
, ret
);
4226 static inline struct page
*
4227 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
4228 unsigned int alloc_flags
, const struct alloc_context
*ac
,
4229 enum compact_priority prio
, enum compact_result
*compact_result
)
4231 *compact_result
= COMPACT_SKIPPED
;
4236 should_compact_retry(struct alloc_context
*ac
, unsigned int order
, int alloc_flags
,
4237 enum compact_result compact_result
,
4238 enum compact_priority
*compact_priority
,
4239 int *compaction_retries
)
4244 if (!order
|| order
> PAGE_ALLOC_COSTLY_ORDER
)
4248 * There are setups with compaction disabled which would prefer to loop
4249 * inside the allocator rather than hit the oom killer prematurely.
4250 * Let's give them a good hope and keep retrying while the order-0
4251 * watermarks are OK.
4253 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
4254 ac
->highest_zoneidx
, ac
->nodemask
) {
4255 if (zone_watermark_ok(zone
, 0, min_wmark_pages(zone
),
4256 ac
->highest_zoneidx
, alloc_flags
))
4261 #endif /* CONFIG_COMPACTION */
4263 #ifdef CONFIG_LOCKDEP
4264 static struct lockdep_map __fs_reclaim_map
=
4265 STATIC_LOCKDEP_MAP_INIT("fs_reclaim", &__fs_reclaim_map
);
4267 static bool __need_fs_reclaim(gfp_t gfp_mask
)
4269 gfp_mask
= current_gfp_context(gfp_mask
);
4271 /* no reclaim without waiting on it */
4272 if (!(gfp_mask
& __GFP_DIRECT_RECLAIM
))
4275 /* this guy won't enter reclaim */
4276 if (current
->flags
& PF_MEMALLOC
)
4279 /* We're only interested __GFP_FS allocations for now */
4280 if (!(gfp_mask
& __GFP_FS
))
4283 if (gfp_mask
& __GFP_NOLOCKDEP
)
4289 void __fs_reclaim_acquire(void)
4291 lock_map_acquire(&__fs_reclaim_map
);
4294 void __fs_reclaim_release(void)
4296 lock_map_release(&__fs_reclaim_map
);
4299 void fs_reclaim_acquire(gfp_t gfp_mask
)
4301 if (__need_fs_reclaim(gfp_mask
))
4302 __fs_reclaim_acquire();
4304 EXPORT_SYMBOL_GPL(fs_reclaim_acquire
);
4306 void fs_reclaim_release(gfp_t gfp_mask
)
4308 if (__need_fs_reclaim(gfp_mask
))
4309 __fs_reclaim_release();
4311 EXPORT_SYMBOL_GPL(fs_reclaim_release
);
4314 /* Perform direct synchronous page reclaim */
4315 static unsigned long
4316 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
4317 const struct alloc_context
*ac
)
4319 unsigned int noreclaim_flag
;
4320 unsigned long pflags
, progress
;
4324 /* We now go into synchronous reclaim */
4325 cpuset_memory_pressure_bump();
4326 psi_memstall_enter(&pflags
);
4327 fs_reclaim_acquire(gfp_mask
);
4328 noreclaim_flag
= memalloc_noreclaim_save();
4330 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
4333 memalloc_noreclaim_restore(noreclaim_flag
);
4334 fs_reclaim_release(gfp_mask
);
4335 psi_memstall_leave(&pflags
);
4342 /* The really slow allocator path where we enter direct reclaim */
4343 static inline struct page
*
4344 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
4345 unsigned int alloc_flags
, const struct alloc_context
*ac
,
4346 unsigned long *did_some_progress
)
4348 struct page
*page
= NULL
;
4349 bool drained
= false;
4351 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
4352 if (unlikely(!(*did_some_progress
)))
4356 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
4359 * If an allocation failed after direct reclaim, it could be because
4360 * pages are pinned on the per-cpu lists or in high alloc reserves.
4361 * Shrink them and try again
4363 if (!page
&& !drained
) {
4364 unreserve_highatomic_pageblock(ac
, false);
4365 drain_all_pages(NULL
);
4373 static void wake_all_kswapds(unsigned int order
, gfp_t gfp_mask
,
4374 const struct alloc_context
*ac
)
4378 pg_data_t
*last_pgdat
= NULL
;
4379 enum zone_type highest_zoneidx
= ac
->highest_zoneidx
;
4381 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, highest_zoneidx
,
4383 if (last_pgdat
!= zone
->zone_pgdat
)
4384 wakeup_kswapd(zone
, gfp_mask
, order
, highest_zoneidx
);
4385 last_pgdat
= zone
->zone_pgdat
;
4389 static inline unsigned int
4390 gfp_to_alloc_flags(gfp_t gfp_mask
)
4392 unsigned int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
4395 * __GFP_HIGH is assumed to be the same as ALLOC_HIGH
4396 * and __GFP_KSWAPD_RECLAIM is assumed to be the same as ALLOC_KSWAPD
4397 * to save two branches.
4399 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
4400 BUILD_BUG_ON(__GFP_KSWAPD_RECLAIM
!= (__force gfp_t
) ALLOC_KSWAPD
);
4403 * The caller may dip into page reserves a bit more if the caller
4404 * cannot run direct reclaim, or if the caller has realtime scheduling
4405 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
4406 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
4408 alloc_flags
|= (__force
int)
4409 (gfp_mask
& (__GFP_HIGH
| __GFP_KSWAPD_RECLAIM
));
4411 if (gfp_mask
& __GFP_ATOMIC
) {
4413 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
4414 * if it can't schedule.
4416 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
4417 alloc_flags
|= ALLOC_HARDER
;
4419 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
4420 * comment for __cpuset_node_allowed().
4422 alloc_flags
&= ~ALLOC_CPUSET
;
4423 } else if (unlikely(rt_task(current
)) && !in_interrupt())
4424 alloc_flags
|= ALLOC_HARDER
;
4426 alloc_flags
= current_alloc_flags(gfp_mask
, alloc_flags
);
4431 static bool oom_reserves_allowed(struct task_struct
*tsk
)
4433 if (!tsk_is_oom_victim(tsk
))
4437 * !MMU doesn't have oom reaper so give access to memory reserves
4438 * only to the thread with TIF_MEMDIE set
4440 if (!IS_ENABLED(CONFIG_MMU
) && !test_thread_flag(TIF_MEMDIE
))
4447 * Distinguish requests which really need access to full memory
4448 * reserves from oom victims which can live with a portion of it
4450 static inline int __gfp_pfmemalloc_flags(gfp_t gfp_mask
)
4452 if (unlikely(gfp_mask
& __GFP_NOMEMALLOC
))
4454 if (gfp_mask
& __GFP_MEMALLOC
)
4455 return ALLOC_NO_WATERMARKS
;
4456 if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
4457 return ALLOC_NO_WATERMARKS
;
4458 if (!in_interrupt()) {
4459 if (current
->flags
& PF_MEMALLOC
)
4460 return ALLOC_NO_WATERMARKS
;
4461 else if (oom_reserves_allowed(current
))
4468 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
4470 return !!__gfp_pfmemalloc_flags(gfp_mask
);
4474 * Checks whether it makes sense to retry the reclaim to make a forward progress
4475 * for the given allocation request.
4477 * We give up when we either have tried MAX_RECLAIM_RETRIES in a row
4478 * without success, or when we couldn't even meet the watermark if we
4479 * reclaimed all remaining pages on the LRU lists.
4481 * Returns true if a retry is viable or false to enter the oom path.
4484 should_reclaim_retry(gfp_t gfp_mask
, unsigned order
,
4485 struct alloc_context
*ac
, int alloc_flags
,
4486 bool did_some_progress
, int *no_progress_loops
)
4493 * Costly allocations might have made a progress but this doesn't mean
4494 * their order will become available due to high fragmentation so
4495 * always increment the no progress counter for them
4497 if (did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
)
4498 *no_progress_loops
= 0;
4500 (*no_progress_loops
)++;
4503 * Make sure we converge to OOM if we cannot make any progress
4504 * several times in the row.
4506 if (*no_progress_loops
> MAX_RECLAIM_RETRIES
) {
4507 /* Before OOM, exhaust highatomic_reserve */
4508 return unreserve_highatomic_pageblock(ac
, true);
4512 * Keep reclaiming pages while there is a chance this will lead
4513 * somewhere. If none of the target zones can satisfy our allocation
4514 * request even if all reclaimable pages are considered then we are
4515 * screwed and have to go OOM.
4517 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
4518 ac
->highest_zoneidx
, ac
->nodemask
) {
4519 unsigned long available
;
4520 unsigned long reclaimable
;
4521 unsigned long min_wmark
= min_wmark_pages(zone
);
4524 available
= reclaimable
= zone_reclaimable_pages(zone
);
4525 available
+= zone_page_state_snapshot(zone
, NR_FREE_PAGES
);
4528 * Would the allocation succeed if we reclaimed all
4529 * reclaimable pages?
4531 wmark
= __zone_watermark_ok(zone
, order
, min_wmark
,
4532 ac
->highest_zoneidx
, alloc_flags
, available
);
4533 trace_reclaim_retry_zone(z
, order
, reclaimable
,
4534 available
, min_wmark
, *no_progress_loops
, wmark
);
4537 * If we didn't make any progress and have a lot of
4538 * dirty + writeback pages then we should wait for
4539 * an IO to complete to slow down the reclaim and
4540 * prevent from pre mature OOM
4542 if (!did_some_progress
) {
4543 unsigned long write_pending
;
4545 write_pending
= zone_page_state_snapshot(zone
,
4546 NR_ZONE_WRITE_PENDING
);
4548 if (2 * write_pending
> reclaimable
) {
4549 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
4561 * Memory allocation/reclaim might be called from a WQ context and the
4562 * current implementation of the WQ concurrency control doesn't
4563 * recognize that a particular WQ is congested if the worker thread is
4564 * looping without ever sleeping. Therefore we have to do a short sleep
4565 * here rather than calling cond_resched().
4567 if (current
->flags
& PF_WQ_WORKER
)
4568 schedule_timeout_uninterruptible(1);
4575 check_retry_cpuset(int cpuset_mems_cookie
, struct alloc_context
*ac
)
4578 * It's possible that cpuset's mems_allowed and the nodemask from
4579 * mempolicy don't intersect. This should be normally dealt with by
4580 * policy_nodemask(), but it's possible to race with cpuset update in
4581 * such a way the check therein was true, and then it became false
4582 * before we got our cpuset_mems_cookie here.
4583 * This assumes that for all allocations, ac->nodemask can come only
4584 * from MPOL_BIND mempolicy (whose documented semantics is to be ignored
4585 * when it does not intersect with the cpuset restrictions) or the
4586 * caller can deal with a violated nodemask.
4588 if (cpusets_enabled() && ac
->nodemask
&&
4589 !cpuset_nodemask_valid_mems_allowed(ac
->nodemask
)) {
4590 ac
->nodemask
= NULL
;
4595 * When updating a task's mems_allowed or mempolicy nodemask, it is
4596 * possible to race with parallel threads in such a way that our
4597 * allocation can fail while the mask is being updated. If we are about
4598 * to fail, check if the cpuset changed during allocation and if so,
4601 if (read_mems_allowed_retry(cpuset_mems_cookie
))
4607 static inline struct page
*
4608 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
4609 struct alloc_context
*ac
)
4611 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
4612 const bool costly_order
= order
> PAGE_ALLOC_COSTLY_ORDER
;
4613 struct page
*page
= NULL
;
4614 unsigned int alloc_flags
;
4615 unsigned long did_some_progress
;
4616 enum compact_priority compact_priority
;
4617 enum compact_result compact_result
;
4618 int compaction_retries
;
4619 int no_progress_loops
;
4620 unsigned int cpuset_mems_cookie
;
4624 * We also sanity check to catch abuse of atomic reserves being used by
4625 * callers that are not in atomic context.
4627 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
4628 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
4629 gfp_mask
&= ~__GFP_ATOMIC
;
4632 compaction_retries
= 0;
4633 no_progress_loops
= 0;
4634 compact_priority
= DEF_COMPACT_PRIORITY
;
4635 cpuset_mems_cookie
= read_mems_allowed_begin();
4638 * The fast path uses conservative alloc_flags to succeed only until
4639 * kswapd needs to be woken up, and to avoid the cost of setting up
4640 * alloc_flags precisely. So we do that now.
4642 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
4645 * We need to recalculate the starting point for the zonelist iterator
4646 * because we might have used different nodemask in the fast path, or
4647 * there was a cpuset modification and we are retrying - otherwise we
4648 * could end up iterating over non-eligible zones endlessly.
4650 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
4651 ac
->highest_zoneidx
, ac
->nodemask
);
4652 if (!ac
->preferred_zoneref
->zone
)
4655 if (alloc_flags
& ALLOC_KSWAPD
)
4656 wake_all_kswapds(order
, gfp_mask
, ac
);
4659 * The adjusted alloc_flags might result in immediate success, so try
4662 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
4667 * For costly allocations, try direct compaction first, as it's likely
4668 * that we have enough base pages and don't need to reclaim. For non-
4669 * movable high-order allocations, do that as well, as compaction will
4670 * try prevent permanent fragmentation by migrating from blocks of the
4672 * Don't try this for allocations that are allowed to ignore
4673 * watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen.
4675 if (can_direct_reclaim
&&
4677 (order
> 0 && ac
->migratetype
!= MIGRATE_MOVABLE
))
4678 && !gfp_pfmemalloc_allowed(gfp_mask
)) {
4679 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
4681 INIT_COMPACT_PRIORITY
,
4687 * Checks for costly allocations with __GFP_NORETRY, which
4688 * includes some THP page fault allocations
4690 if (costly_order
&& (gfp_mask
& __GFP_NORETRY
)) {
4692 * If allocating entire pageblock(s) and compaction
4693 * failed because all zones are below low watermarks
4694 * or is prohibited because it recently failed at this
4695 * order, fail immediately unless the allocator has
4696 * requested compaction and reclaim retry.
4699 * - potentially very expensive because zones are far
4700 * below their low watermarks or this is part of very
4701 * bursty high order allocations,
4702 * - not guaranteed to help because isolate_freepages()
4703 * may not iterate over freed pages as part of its
4705 * - unlikely to make entire pageblocks free on its
4708 if (compact_result
== COMPACT_SKIPPED
||
4709 compact_result
== COMPACT_DEFERRED
)
4713 * Looks like reclaim/compaction is worth trying, but
4714 * sync compaction could be very expensive, so keep
4715 * using async compaction.
4717 compact_priority
= INIT_COMPACT_PRIORITY
;
4722 /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
4723 if (alloc_flags
& ALLOC_KSWAPD
)
4724 wake_all_kswapds(order
, gfp_mask
, ac
);
4726 reserve_flags
= __gfp_pfmemalloc_flags(gfp_mask
);
4728 alloc_flags
= current_alloc_flags(gfp_mask
, reserve_flags
);
4731 * Reset the nodemask and zonelist iterators if memory policies can be
4732 * ignored. These allocations are high priority and system rather than
4735 if (!(alloc_flags
& ALLOC_CPUSET
) || reserve_flags
) {
4736 ac
->nodemask
= NULL
;
4737 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
4738 ac
->highest_zoneidx
, ac
->nodemask
);
4741 /* Attempt with potentially adjusted zonelist and alloc_flags */
4742 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
4746 /* Caller is not willing to reclaim, we can't balance anything */
4747 if (!can_direct_reclaim
)
4750 /* Avoid recursion of direct reclaim */
4751 if (current
->flags
& PF_MEMALLOC
)
4754 /* Try direct reclaim and then allocating */
4755 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
4756 &did_some_progress
);
4760 /* Try direct compaction and then allocating */
4761 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
4762 compact_priority
, &compact_result
);
4766 /* Do not loop if specifically requested */
4767 if (gfp_mask
& __GFP_NORETRY
)
4771 * Do not retry costly high order allocations unless they are
4772 * __GFP_RETRY_MAYFAIL
4774 if (costly_order
&& !(gfp_mask
& __GFP_RETRY_MAYFAIL
))
4777 if (should_reclaim_retry(gfp_mask
, order
, ac
, alloc_flags
,
4778 did_some_progress
> 0, &no_progress_loops
))
4782 * It doesn't make any sense to retry for the compaction if the order-0
4783 * reclaim is not able to make any progress because the current
4784 * implementation of the compaction depends on the sufficient amount
4785 * of free memory (see __compaction_suitable)
4787 if (did_some_progress
> 0 &&
4788 should_compact_retry(ac
, order
, alloc_flags
,
4789 compact_result
, &compact_priority
,
4790 &compaction_retries
))
4794 /* Deal with possible cpuset update races before we start OOM killing */
4795 if (check_retry_cpuset(cpuset_mems_cookie
, ac
))
4798 /* Reclaim has failed us, start killing things */
4799 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
4803 /* Avoid allocations with no watermarks from looping endlessly */
4804 if (tsk_is_oom_victim(current
) &&
4805 (alloc_flags
& ALLOC_OOM
||
4806 (gfp_mask
& __GFP_NOMEMALLOC
)))
4809 /* Retry as long as the OOM killer is making progress */
4810 if (did_some_progress
) {
4811 no_progress_loops
= 0;
4816 /* Deal with possible cpuset update races before we fail */
4817 if (check_retry_cpuset(cpuset_mems_cookie
, ac
))
4821 * Make sure that __GFP_NOFAIL request doesn't leak out and make sure
4824 if (gfp_mask
& __GFP_NOFAIL
) {
4826 * All existing users of the __GFP_NOFAIL are blockable, so warn
4827 * of any new users that actually require GFP_NOWAIT
4829 if (WARN_ON_ONCE(!can_direct_reclaim
))
4833 * PF_MEMALLOC request from this context is rather bizarre
4834 * because we cannot reclaim anything and only can loop waiting
4835 * for somebody to do a work for us
4837 WARN_ON_ONCE(current
->flags
& PF_MEMALLOC
);
4840 * non failing costly orders are a hard requirement which we
4841 * are not prepared for much so let's warn about these users
4842 * so that we can identify them and convert them to something
4845 WARN_ON_ONCE(order
> PAGE_ALLOC_COSTLY_ORDER
);
4848 * Help non-failing allocations by giving them access to memory
4849 * reserves but do not use ALLOC_NO_WATERMARKS because this
4850 * could deplete whole memory reserves which would just make
4851 * the situation worse
4853 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
, ALLOC_HARDER
, ac
);
4861 warn_alloc(gfp_mask
, ac
->nodemask
,
4862 "page allocation failure: order:%u", order
);
4867 static inline bool prepare_alloc_pages(gfp_t gfp_mask
, unsigned int order
,
4868 int preferred_nid
, nodemask_t
*nodemask
,
4869 struct alloc_context
*ac
, gfp_t
*alloc_mask
,
4870 unsigned int *alloc_flags
)
4872 ac
->highest_zoneidx
= gfp_zone(gfp_mask
);
4873 ac
->zonelist
= node_zonelist(preferred_nid
, gfp_mask
);
4874 ac
->nodemask
= nodemask
;
4875 ac
->migratetype
= gfp_migratetype(gfp_mask
);
4877 if (cpusets_enabled()) {
4878 *alloc_mask
|= __GFP_HARDWALL
;
4880 * When we are in the interrupt context, it is irrelevant
4881 * to the current task context. It means that any node ok.
4883 if (!in_interrupt() && !ac
->nodemask
)
4884 ac
->nodemask
= &cpuset_current_mems_allowed
;
4886 *alloc_flags
|= ALLOC_CPUSET
;
4889 fs_reclaim_acquire(gfp_mask
);
4890 fs_reclaim_release(gfp_mask
);
4892 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
4894 if (should_fail_alloc_page(gfp_mask
, order
))
4897 *alloc_flags
= current_alloc_flags(gfp_mask
, *alloc_flags
);
4899 /* Dirty zone balancing only done in the fast path */
4900 ac
->spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
4903 * The preferred zone is used for statistics but crucially it is
4904 * also used as the starting point for the zonelist iterator. It
4905 * may get reset for allocations that ignore memory policies.
4907 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
4908 ac
->highest_zoneidx
, ac
->nodemask
);
4914 * This is the 'heart' of the zoned buddy allocator.
4917 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
, int preferred_nid
,
4918 nodemask_t
*nodemask
)
4921 unsigned int alloc_flags
= ALLOC_WMARK_LOW
;
4922 gfp_t alloc_mask
; /* The gfp_t that was actually used for allocation */
4923 struct alloc_context ac
= { };
4926 * There are several places where we assume that the order value is sane
4927 * so bail out early if the request is out of bound.
4929 if (unlikely(order
>= MAX_ORDER
)) {
4930 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
4934 gfp_mask
&= gfp_allowed_mask
;
4935 alloc_mask
= gfp_mask
;
4936 if (!prepare_alloc_pages(gfp_mask
, order
, preferred_nid
, nodemask
, &ac
, &alloc_mask
, &alloc_flags
))
4940 * Forbid the first pass from falling back to types that fragment
4941 * memory until all local zones are considered.
4943 alloc_flags
|= alloc_flags_nofragment(ac
.preferred_zoneref
->zone
, gfp_mask
);
4945 /* First allocation attempt */
4946 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
4951 * Apply scoped allocation constraints. This is mainly about GFP_NOFS
4952 * resp. GFP_NOIO which has to be inherited for all allocation requests
4953 * from a particular context which has been marked by
4954 * memalloc_no{fs,io}_{save,restore}.
4956 alloc_mask
= current_gfp_context(gfp_mask
);
4957 ac
.spread_dirty_pages
= false;
4960 * Restore the original nodemask if it was potentially replaced with
4961 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
4963 ac
.nodemask
= nodemask
;
4965 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
4968 if (memcg_kmem_enabled() && (gfp_mask
& __GFP_ACCOUNT
) && page
&&
4969 unlikely(__memcg_kmem_charge_page(page
, gfp_mask
, order
) != 0)) {
4970 __free_pages(page
, order
);
4974 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
4978 EXPORT_SYMBOL(__alloc_pages_nodemask
);
4981 * Common helper functions. Never use with __GFP_HIGHMEM because the returned
4982 * address cannot represent highmem pages. Use alloc_pages and then kmap if
4983 * you need to access high mem.
4985 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
4989 page
= alloc_pages(gfp_mask
& ~__GFP_HIGHMEM
, order
);
4992 return (unsigned long) page_address(page
);
4994 EXPORT_SYMBOL(__get_free_pages
);
4996 unsigned long get_zeroed_page(gfp_t gfp_mask
)
4998 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
5000 EXPORT_SYMBOL(get_zeroed_page
);
5002 static inline void free_the_page(struct page
*page
, unsigned int order
)
5004 if (order
== 0) /* Via pcp? */
5005 free_unref_page(page
);
5007 __free_pages_ok(page
, order
, FPI_NONE
);
5010 void __free_pages(struct page
*page
, unsigned int order
)
5012 if (put_page_testzero(page
))
5013 free_the_page(page
, order
);
5014 else if (!PageHead(page
))
5016 free_the_page(page
+ (1 << order
), order
);
5018 EXPORT_SYMBOL(__free_pages
);
5020 void free_pages(unsigned long addr
, unsigned int order
)
5023 VM_BUG_ON(!virt_addr_valid((void *)addr
));
5024 __free_pages(virt_to_page((void *)addr
), order
);
5028 EXPORT_SYMBOL(free_pages
);
5032 * An arbitrary-length arbitrary-offset area of memory which resides
5033 * within a 0 or higher order page. Multiple fragments within that page
5034 * are individually refcounted, in the page's reference counter.
5036 * The page_frag functions below provide a simple allocation framework for
5037 * page fragments. This is used by the network stack and network device
5038 * drivers to provide a backing region of memory for use as either an
5039 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
5041 static struct page
*__page_frag_cache_refill(struct page_frag_cache
*nc
,
5044 struct page
*page
= NULL
;
5045 gfp_t gfp
= gfp_mask
;
5047 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
5048 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
5050 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
5051 PAGE_FRAG_CACHE_MAX_ORDER
);
5052 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
5054 if (unlikely(!page
))
5055 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
5057 nc
->va
= page
? page_address(page
) : NULL
;
5062 void __page_frag_cache_drain(struct page
*page
, unsigned int count
)
5064 VM_BUG_ON_PAGE(page_ref_count(page
) == 0, page
);
5066 if (page_ref_sub_and_test(page
, count
))
5067 free_the_page(page
, compound_order(page
));
5069 EXPORT_SYMBOL(__page_frag_cache_drain
);
5071 void *page_frag_alloc(struct page_frag_cache
*nc
,
5072 unsigned int fragsz
, gfp_t gfp_mask
)
5074 unsigned int size
= PAGE_SIZE
;
5078 if (unlikely(!nc
->va
)) {
5080 page
= __page_frag_cache_refill(nc
, gfp_mask
);
5084 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
5085 /* if size can vary use size else just use PAGE_SIZE */
5088 /* Even if we own the page, we do not use atomic_set().
5089 * This would break get_page_unless_zero() users.
5091 page_ref_add(page
, PAGE_FRAG_CACHE_MAX_SIZE
);
5093 /* reset page count bias and offset to start of new frag */
5094 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
5095 nc
->pagecnt_bias
= PAGE_FRAG_CACHE_MAX_SIZE
+ 1;
5099 offset
= nc
->offset
- fragsz
;
5100 if (unlikely(offset
< 0)) {
5101 page
= virt_to_page(nc
->va
);
5103 if (!page_ref_sub_and_test(page
, nc
->pagecnt_bias
))
5106 if (unlikely(nc
->pfmemalloc
)) {
5107 free_the_page(page
, compound_order(page
));
5111 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
5112 /* if size can vary use size else just use PAGE_SIZE */
5115 /* OK, page count is 0, we can safely set it */
5116 set_page_count(page
, PAGE_FRAG_CACHE_MAX_SIZE
+ 1);
5118 /* reset page count bias and offset to start of new frag */
5119 nc
->pagecnt_bias
= PAGE_FRAG_CACHE_MAX_SIZE
+ 1;
5120 offset
= size
- fragsz
;
5124 nc
->offset
= offset
;
5126 return nc
->va
+ offset
;
5128 EXPORT_SYMBOL(page_frag_alloc
);
5131 * Frees a page fragment allocated out of either a compound or order 0 page.
5133 void page_frag_free(void *addr
)
5135 struct page
*page
= virt_to_head_page(addr
);
5137 if (unlikely(put_page_testzero(page
)))
5138 free_the_page(page
, compound_order(page
));
5140 EXPORT_SYMBOL(page_frag_free
);
5142 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
5146 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
5147 unsigned long used
= addr
+ PAGE_ALIGN(size
);
5149 split_page(virt_to_page((void *)addr
), order
);
5150 while (used
< alloc_end
) {
5155 return (void *)addr
;
5159 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
5160 * @size: the number of bytes to allocate
5161 * @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP
5163 * This function is similar to alloc_pages(), except that it allocates the
5164 * minimum number of pages to satisfy the request. alloc_pages() can only
5165 * allocate memory in power-of-two pages.
5167 * This function is also limited by MAX_ORDER.
5169 * Memory allocated by this function must be released by free_pages_exact().
5171 * Return: pointer to the allocated area or %NULL in case of error.
5173 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
5175 unsigned int order
= get_order(size
);
5178 if (WARN_ON_ONCE(gfp_mask
& __GFP_COMP
))
5179 gfp_mask
&= ~__GFP_COMP
;
5181 addr
= __get_free_pages(gfp_mask
, order
);
5182 return make_alloc_exact(addr
, order
, size
);
5184 EXPORT_SYMBOL(alloc_pages_exact
);
5187 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
5189 * @nid: the preferred node ID where memory should be allocated
5190 * @size: the number of bytes to allocate
5191 * @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP
5193 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
5196 * Return: pointer to the allocated area or %NULL in case of error.
5198 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
5200 unsigned int order
= get_order(size
);
5203 if (WARN_ON_ONCE(gfp_mask
& __GFP_COMP
))
5204 gfp_mask
&= ~__GFP_COMP
;
5206 p
= alloc_pages_node(nid
, gfp_mask
, order
);
5209 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
5213 * free_pages_exact - release memory allocated via alloc_pages_exact()
5214 * @virt: the value returned by alloc_pages_exact.
5215 * @size: size of allocation, same value as passed to alloc_pages_exact().
5217 * Release the memory allocated by a previous call to alloc_pages_exact.
5219 void free_pages_exact(void *virt
, size_t size
)
5221 unsigned long addr
= (unsigned long)virt
;
5222 unsigned long end
= addr
+ PAGE_ALIGN(size
);
5224 while (addr
< end
) {
5229 EXPORT_SYMBOL(free_pages_exact
);
5232 * nr_free_zone_pages - count number of pages beyond high watermark
5233 * @offset: The zone index of the highest zone
5235 * nr_free_zone_pages() counts the number of pages which are beyond the
5236 * high watermark within all zones at or below a given zone index. For each
5237 * zone, the number of pages is calculated as:
5239 * nr_free_zone_pages = managed_pages - high_pages
5241 * Return: number of pages beyond high watermark.
5243 static unsigned long nr_free_zone_pages(int offset
)
5248 /* Just pick one node, since fallback list is circular */
5249 unsigned long sum
= 0;
5251 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
5253 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
5254 unsigned long size
= zone_managed_pages(zone
);
5255 unsigned long high
= high_wmark_pages(zone
);
5264 * nr_free_buffer_pages - count number of pages beyond high watermark
5266 * nr_free_buffer_pages() counts the number of pages which are beyond the high
5267 * watermark within ZONE_DMA and ZONE_NORMAL.
5269 * Return: number of pages beyond high watermark within ZONE_DMA and
5272 unsigned long nr_free_buffer_pages(void)
5274 return nr_free_zone_pages(gfp_zone(GFP_USER
));
5276 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
5278 static inline void show_node(struct zone
*zone
)
5280 if (IS_ENABLED(CONFIG_NUMA
))
5281 printk("Node %d ", zone_to_nid(zone
));
5284 long si_mem_available(void)
5287 unsigned long pagecache
;
5288 unsigned long wmark_low
= 0;
5289 unsigned long pages
[NR_LRU_LISTS
];
5290 unsigned long reclaimable
;
5294 for (lru
= LRU_BASE
; lru
< NR_LRU_LISTS
; lru
++)
5295 pages
[lru
] = global_node_page_state(NR_LRU_BASE
+ lru
);
5298 wmark_low
+= low_wmark_pages(zone
);
5301 * Estimate the amount of memory available for userspace allocations,
5302 * without causing swapping.
5304 available
= global_zone_page_state(NR_FREE_PAGES
) - totalreserve_pages
;
5307 * Not all the page cache can be freed, otherwise the system will
5308 * start swapping. Assume at least half of the page cache, or the
5309 * low watermark worth of cache, needs to stay.
5311 pagecache
= pages
[LRU_ACTIVE_FILE
] + pages
[LRU_INACTIVE_FILE
];
5312 pagecache
-= min(pagecache
/ 2, wmark_low
);
5313 available
+= pagecache
;
5316 * Part of the reclaimable slab and other kernel memory consists of
5317 * items that are in use, and cannot be freed. Cap this estimate at the
5320 reclaimable
= global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B
) +
5321 global_node_page_state(NR_KERNEL_MISC_RECLAIMABLE
);
5322 available
+= reclaimable
- min(reclaimable
/ 2, wmark_low
);
5328 EXPORT_SYMBOL_GPL(si_mem_available
);
5330 void si_meminfo(struct sysinfo
*val
)
5332 val
->totalram
= totalram_pages();
5333 val
->sharedram
= global_node_page_state(NR_SHMEM
);
5334 val
->freeram
= global_zone_page_state(NR_FREE_PAGES
);
5335 val
->bufferram
= nr_blockdev_pages();
5336 val
->totalhigh
= totalhigh_pages();
5337 val
->freehigh
= nr_free_highpages();
5338 val
->mem_unit
= PAGE_SIZE
;
5341 EXPORT_SYMBOL(si_meminfo
);
5344 void si_meminfo_node(struct sysinfo
*val
, int nid
)
5346 int zone_type
; /* needs to be signed */
5347 unsigned long managed_pages
= 0;
5348 unsigned long managed_highpages
= 0;
5349 unsigned long free_highpages
= 0;
5350 pg_data_t
*pgdat
= NODE_DATA(nid
);
5352 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
5353 managed_pages
+= zone_managed_pages(&pgdat
->node_zones
[zone_type
]);
5354 val
->totalram
= managed_pages
;
5355 val
->sharedram
= node_page_state(pgdat
, NR_SHMEM
);
5356 val
->freeram
= sum_zone_node_page_state(nid
, NR_FREE_PAGES
);
5357 #ifdef CONFIG_HIGHMEM
5358 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
5359 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
5361 if (is_highmem(zone
)) {
5362 managed_highpages
+= zone_managed_pages(zone
);
5363 free_highpages
+= zone_page_state(zone
, NR_FREE_PAGES
);
5366 val
->totalhigh
= managed_highpages
;
5367 val
->freehigh
= free_highpages
;
5369 val
->totalhigh
= managed_highpages
;
5370 val
->freehigh
= free_highpages
;
5372 val
->mem_unit
= PAGE_SIZE
;
5377 * Determine whether the node should be displayed or not, depending on whether
5378 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
5380 static bool show_mem_node_skip(unsigned int flags
, int nid
, nodemask_t
*nodemask
)
5382 if (!(flags
& SHOW_MEM_FILTER_NODES
))
5386 * no node mask - aka implicit memory numa policy. Do not bother with
5387 * the synchronization - read_mems_allowed_begin - because we do not
5388 * have to be precise here.
5391 nodemask
= &cpuset_current_mems_allowed
;
5393 return !node_isset(nid
, *nodemask
);
5396 #define K(x) ((x) << (PAGE_SHIFT-10))
5398 static void show_migration_types(unsigned char type
)
5400 static const char types
[MIGRATE_TYPES
] = {
5401 [MIGRATE_UNMOVABLE
] = 'U',
5402 [MIGRATE_MOVABLE
] = 'M',
5403 [MIGRATE_RECLAIMABLE
] = 'E',
5404 [MIGRATE_HIGHATOMIC
] = 'H',
5406 [MIGRATE_CMA
] = 'C',
5408 #ifdef CONFIG_MEMORY_ISOLATION
5409 [MIGRATE_ISOLATE
] = 'I',
5412 char tmp
[MIGRATE_TYPES
+ 1];
5416 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
5417 if (type
& (1 << i
))
5422 printk(KERN_CONT
"(%s) ", tmp
);
5426 * Show free area list (used inside shift_scroll-lock stuff)
5427 * We also calculate the percentage fragmentation. We do this by counting the
5428 * memory on each free list with the exception of the first item on the list.
5431 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
5434 void show_free_areas(unsigned int filter
, nodemask_t
*nodemask
)
5436 unsigned long free_pcp
= 0;
5441 for_each_populated_zone(zone
) {
5442 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
5445 for_each_online_cpu(cpu
)
5446 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
5449 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
5450 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
5451 " unevictable:%lu dirty:%lu writeback:%lu\n"
5452 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
5453 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
5454 " free:%lu free_pcp:%lu free_cma:%lu\n",
5455 global_node_page_state(NR_ACTIVE_ANON
),
5456 global_node_page_state(NR_INACTIVE_ANON
),
5457 global_node_page_state(NR_ISOLATED_ANON
),
5458 global_node_page_state(NR_ACTIVE_FILE
),
5459 global_node_page_state(NR_INACTIVE_FILE
),
5460 global_node_page_state(NR_ISOLATED_FILE
),
5461 global_node_page_state(NR_UNEVICTABLE
),
5462 global_node_page_state(NR_FILE_DIRTY
),
5463 global_node_page_state(NR_WRITEBACK
),
5464 global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B
),
5465 global_node_page_state_pages(NR_SLAB_UNRECLAIMABLE_B
),
5466 global_node_page_state(NR_FILE_MAPPED
),
5467 global_node_page_state(NR_SHMEM
),
5468 global_zone_page_state(NR_PAGETABLE
),
5469 global_zone_page_state(NR_BOUNCE
),
5470 global_zone_page_state(NR_FREE_PAGES
),
5472 global_zone_page_state(NR_FREE_CMA_PAGES
));
5474 for_each_online_pgdat(pgdat
) {
5475 if (show_mem_node_skip(filter
, pgdat
->node_id
, nodemask
))
5479 " active_anon:%lukB"
5480 " inactive_anon:%lukB"
5481 " active_file:%lukB"
5482 " inactive_file:%lukB"
5483 " unevictable:%lukB"
5484 " isolated(anon):%lukB"
5485 " isolated(file):%lukB"
5490 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5492 " shmem_pmdmapped: %lukB"
5495 " writeback_tmp:%lukB"
5496 " kernel_stack:%lukB"
5497 #ifdef CONFIG_SHADOW_CALL_STACK
5498 " shadow_call_stack:%lukB"
5500 " all_unreclaimable? %s"
5503 K(node_page_state(pgdat
, NR_ACTIVE_ANON
)),
5504 K(node_page_state(pgdat
, NR_INACTIVE_ANON
)),
5505 K(node_page_state(pgdat
, NR_ACTIVE_FILE
)),
5506 K(node_page_state(pgdat
, NR_INACTIVE_FILE
)),
5507 K(node_page_state(pgdat
, NR_UNEVICTABLE
)),
5508 K(node_page_state(pgdat
, NR_ISOLATED_ANON
)),
5509 K(node_page_state(pgdat
, NR_ISOLATED_FILE
)),
5510 K(node_page_state(pgdat
, NR_FILE_MAPPED
)),
5511 K(node_page_state(pgdat
, NR_FILE_DIRTY
)),
5512 K(node_page_state(pgdat
, NR_WRITEBACK
)),
5513 K(node_page_state(pgdat
, NR_SHMEM
)),
5514 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5515 K(node_page_state(pgdat
, NR_SHMEM_THPS
) * HPAGE_PMD_NR
),
5516 K(node_page_state(pgdat
, NR_SHMEM_PMDMAPPED
)
5518 K(node_page_state(pgdat
, NR_ANON_THPS
) * HPAGE_PMD_NR
),
5520 K(node_page_state(pgdat
, NR_WRITEBACK_TEMP
)),
5521 node_page_state(pgdat
, NR_KERNEL_STACK_KB
),
5522 #ifdef CONFIG_SHADOW_CALL_STACK
5523 node_page_state(pgdat
, NR_KERNEL_SCS_KB
),
5525 pgdat
->kswapd_failures
>= MAX_RECLAIM_RETRIES
?
5529 for_each_populated_zone(zone
) {
5532 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
5536 for_each_online_cpu(cpu
)
5537 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
5546 " reserved_highatomic:%luKB"
5547 " active_anon:%lukB"
5548 " inactive_anon:%lukB"
5549 " active_file:%lukB"
5550 " inactive_file:%lukB"
5551 " unevictable:%lukB"
5552 " writepending:%lukB"
5563 K(zone_page_state(zone
, NR_FREE_PAGES
)),
5564 K(min_wmark_pages(zone
)),
5565 K(low_wmark_pages(zone
)),
5566 K(high_wmark_pages(zone
)),
5567 K(zone
->nr_reserved_highatomic
),
5568 K(zone_page_state(zone
, NR_ZONE_ACTIVE_ANON
)),
5569 K(zone_page_state(zone
, NR_ZONE_INACTIVE_ANON
)),
5570 K(zone_page_state(zone
, NR_ZONE_ACTIVE_FILE
)),
5571 K(zone_page_state(zone
, NR_ZONE_INACTIVE_FILE
)),
5572 K(zone_page_state(zone
, NR_ZONE_UNEVICTABLE
)),
5573 K(zone_page_state(zone
, NR_ZONE_WRITE_PENDING
)),
5574 K(zone
->present_pages
),
5575 K(zone_managed_pages(zone
)),
5576 K(zone_page_state(zone
, NR_MLOCK
)),
5577 K(zone_page_state(zone
, NR_PAGETABLE
)),
5578 K(zone_page_state(zone
, NR_BOUNCE
)),
5580 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
5581 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)));
5582 printk("lowmem_reserve[]:");
5583 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
5584 printk(KERN_CONT
" %ld", zone
->lowmem_reserve
[i
]);
5585 printk(KERN_CONT
"\n");
5588 for_each_populated_zone(zone
) {
5590 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
5591 unsigned char types
[MAX_ORDER
];
5593 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
5596 printk(KERN_CONT
"%s: ", zone
->name
);
5598 spin_lock_irqsave(&zone
->lock
, flags
);
5599 for (order
= 0; order
< MAX_ORDER
; order
++) {
5600 struct free_area
*area
= &zone
->free_area
[order
];
5603 nr
[order
] = area
->nr_free
;
5604 total
+= nr
[order
] << order
;
5607 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
5608 if (!free_area_empty(area
, type
))
5609 types
[order
] |= 1 << type
;
5612 spin_unlock_irqrestore(&zone
->lock
, flags
);
5613 for (order
= 0; order
< MAX_ORDER
; order
++) {
5614 printk(KERN_CONT
"%lu*%lukB ",
5615 nr
[order
], K(1UL) << order
);
5617 show_migration_types(types
[order
]);
5619 printk(KERN_CONT
"= %lukB\n", K(total
));
5622 hugetlb_show_meminfo();
5624 printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES
));
5626 show_swap_cache_info();
5629 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
5631 zoneref
->zone
= zone
;
5632 zoneref
->zone_idx
= zone_idx(zone
);
5636 * Builds allocation fallback zone lists.
5638 * Add all populated zones of a node to the zonelist.
5640 static int build_zonerefs_node(pg_data_t
*pgdat
, struct zoneref
*zonerefs
)
5643 enum zone_type zone_type
= MAX_NR_ZONES
;
5648 zone
= pgdat
->node_zones
+ zone_type
;
5649 if (managed_zone(zone
)) {
5650 zoneref_set_zone(zone
, &zonerefs
[nr_zones
++]);
5651 check_highest_zone(zone_type
);
5653 } while (zone_type
);
5660 static int __parse_numa_zonelist_order(char *s
)
5663 * We used to support different zonlists modes but they turned
5664 * out to be just not useful. Let's keep the warning in place
5665 * if somebody still use the cmd line parameter so that we do
5666 * not fail it silently
5668 if (!(*s
== 'd' || *s
== 'D' || *s
== 'n' || *s
== 'N')) {
5669 pr_warn("Ignoring unsupported numa_zonelist_order value: %s\n", s
);
5675 char numa_zonelist_order
[] = "Node";
5678 * sysctl handler for numa_zonelist_order
5680 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
5681 void *buffer
, size_t *length
, loff_t
*ppos
)
5684 return __parse_numa_zonelist_order(buffer
);
5685 return proc_dostring(table
, write
, buffer
, length
, ppos
);
5689 #define MAX_NODE_LOAD (nr_online_nodes)
5690 static int node_load
[MAX_NUMNODES
];
5693 * find_next_best_node - find the next node that should appear in a given node's fallback list
5694 * @node: node whose fallback list we're appending
5695 * @used_node_mask: nodemask_t of already used nodes
5697 * We use a number of factors to determine which is the next node that should
5698 * appear on a given node's fallback list. The node should not have appeared
5699 * already in @node's fallback list, and it should be the next closest node
5700 * according to the distance array (which contains arbitrary distance values
5701 * from each node to each node in the system), and should also prefer nodes
5702 * with no CPUs, since presumably they'll have very little allocation pressure
5703 * on them otherwise.
5705 * Return: node id of the found node or %NUMA_NO_NODE if no node is found.
5707 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
5710 int min_val
= INT_MAX
;
5711 int best_node
= NUMA_NO_NODE
;
5713 /* Use the local node if we haven't already */
5714 if (!node_isset(node
, *used_node_mask
)) {
5715 node_set(node
, *used_node_mask
);
5719 for_each_node_state(n
, N_MEMORY
) {
5721 /* Don't want a node to appear more than once */
5722 if (node_isset(n
, *used_node_mask
))
5725 /* Use the distance array to find the distance */
5726 val
= node_distance(node
, n
);
5728 /* Penalize nodes under us ("prefer the next node") */
5731 /* Give preference to headless and unused nodes */
5732 if (!cpumask_empty(cpumask_of_node(n
)))
5733 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
5735 /* Slight preference for less loaded node */
5736 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
5737 val
+= node_load
[n
];
5739 if (val
< min_val
) {
5746 node_set(best_node
, *used_node_mask
);
5753 * Build zonelists ordered by node and zones within node.
5754 * This results in maximum locality--normal zone overflows into local
5755 * DMA zone, if any--but risks exhausting DMA zone.
5757 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int *node_order
,
5760 struct zoneref
*zonerefs
;
5763 zonerefs
= pgdat
->node_zonelists
[ZONELIST_FALLBACK
]._zonerefs
;
5765 for (i
= 0; i
< nr_nodes
; i
++) {
5768 pg_data_t
*node
= NODE_DATA(node_order
[i
]);
5770 nr_zones
= build_zonerefs_node(node
, zonerefs
);
5771 zonerefs
+= nr_zones
;
5773 zonerefs
->zone
= NULL
;
5774 zonerefs
->zone_idx
= 0;
5778 * Build gfp_thisnode zonelists
5780 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
5782 struct zoneref
*zonerefs
;
5785 zonerefs
= pgdat
->node_zonelists
[ZONELIST_NOFALLBACK
]._zonerefs
;
5786 nr_zones
= build_zonerefs_node(pgdat
, zonerefs
);
5787 zonerefs
+= nr_zones
;
5788 zonerefs
->zone
= NULL
;
5789 zonerefs
->zone_idx
= 0;
5793 * Build zonelists ordered by zone and nodes within zones.
5794 * This results in conserving DMA zone[s] until all Normal memory is
5795 * exhausted, but results in overflowing to remote node while memory
5796 * may still exist in local DMA zone.
5799 static void build_zonelists(pg_data_t
*pgdat
)
5801 static int node_order
[MAX_NUMNODES
];
5802 int node
, load
, nr_nodes
= 0;
5803 nodemask_t used_mask
= NODE_MASK_NONE
;
5804 int local_node
, prev_node
;
5806 /* NUMA-aware ordering of nodes */
5807 local_node
= pgdat
->node_id
;
5808 load
= nr_online_nodes
;
5809 prev_node
= local_node
;
5811 memset(node_order
, 0, sizeof(node_order
));
5812 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
5814 * We don't want to pressure a particular node.
5815 * So adding penalty to the first node in same
5816 * distance group to make it round-robin.
5818 if (node_distance(local_node
, node
) !=
5819 node_distance(local_node
, prev_node
))
5820 node_load
[node
] = load
;
5822 node_order
[nr_nodes
++] = node
;
5827 build_zonelists_in_node_order(pgdat
, node_order
, nr_nodes
);
5828 build_thisnode_zonelists(pgdat
);
5831 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5833 * Return node id of node used for "local" allocations.
5834 * I.e., first node id of first zone in arg node's generic zonelist.
5835 * Used for initializing percpu 'numa_mem', which is used primarily
5836 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
5838 int local_memory_node(int node
)
5842 z
= first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
5843 gfp_zone(GFP_KERNEL
),
5845 return zone_to_nid(z
->zone
);
5849 static void setup_min_unmapped_ratio(void);
5850 static void setup_min_slab_ratio(void);
5851 #else /* CONFIG_NUMA */
5853 static void build_zonelists(pg_data_t
*pgdat
)
5855 int node
, local_node
;
5856 struct zoneref
*zonerefs
;
5859 local_node
= pgdat
->node_id
;
5861 zonerefs
= pgdat
->node_zonelists
[ZONELIST_FALLBACK
]._zonerefs
;
5862 nr_zones
= build_zonerefs_node(pgdat
, zonerefs
);
5863 zonerefs
+= nr_zones
;
5866 * Now we build the zonelist so that it contains the zones
5867 * of all the other nodes.
5868 * We don't want to pressure a particular node, so when
5869 * building the zones for node N, we make sure that the
5870 * zones coming right after the local ones are those from
5871 * node N+1 (modulo N)
5873 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
5874 if (!node_online(node
))
5876 nr_zones
= build_zonerefs_node(NODE_DATA(node
), zonerefs
);
5877 zonerefs
+= nr_zones
;
5879 for (node
= 0; node
< local_node
; node
++) {
5880 if (!node_online(node
))
5882 nr_zones
= build_zonerefs_node(NODE_DATA(node
), zonerefs
);
5883 zonerefs
+= nr_zones
;
5886 zonerefs
->zone
= NULL
;
5887 zonerefs
->zone_idx
= 0;
5890 #endif /* CONFIG_NUMA */
5893 * Boot pageset table. One per cpu which is going to be used for all
5894 * zones and all nodes. The parameters will be set in such a way
5895 * that an item put on a list will immediately be handed over to
5896 * the buddy list. This is safe since pageset manipulation is done
5897 * with interrupts disabled.
5899 * The boot_pagesets must be kept even after bootup is complete for
5900 * unused processors and/or zones. They do play a role for bootstrapping
5901 * hotplugged processors.
5903 * zoneinfo_show() and maybe other functions do
5904 * not check if the processor is online before following the pageset pointer.
5905 * Other parts of the kernel may not check if the zone is available.
5907 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
5908 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
5909 static DEFINE_PER_CPU(struct per_cpu_nodestat
, boot_nodestats
);
5911 static void __build_all_zonelists(void *data
)
5914 int __maybe_unused cpu
;
5915 pg_data_t
*self
= data
;
5916 static DEFINE_SPINLOCK(lock
);
5921 memset(node_load
, 0, sizeof(node_load
));
5925 * This node is hotadded and no memory is yet present. So just
5926 * building zonelists is fine - no need to touch other nodes.
5928 if (self
&& !node_online(self
->node_id
)) {
5929 build_zonelists(self
);
5931 for_each_online_node(nid
) {
5932 pg_data_t
*pgdat
= NODE_DATA(nid
);
5934 build_zonelists(pgdat
);
5937 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5939 * We now know the "local memory node" for each node--
5940 * i.e., the node of the first zone in the generic zonelist.
5941 * Set up numa_mem percpu variable for on-line cpus. During
5942 * boot, only the boot cpu should be on-line; we'll init the
5943 * secondary cpus' numa_mem as they come on-line. During
5944 * node/memory hotplug, we'll fixup all on-line cpus.
5946 for_each_online_cpu(cpu
)
5947 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
5954 static noinline
void __init
5955 build_all_zonelists_init(void)
5959 __build_all_zonelists(NULL
);
5962 * Initialize the boot_pagesets that are going to be used
5963 * for bootstrapping processors. The real pagesets for
5964 * each zone will be allocated later when the per cpu
5965 * allocator is available.
5967 * boot_pagesets are used also for bootstrapping offline
5968 * cpus if the system is already booted because the pagesets
5969 * are needed to initialize allocators on a specific cpu too.
5970 * F.e. the percpu allocator needs the page allocator which
5971 * needs the percpu allocator in order to allocate its pagesets
5972 * (a chicken-egg dilemma).
5974 for_each_possible_cpu(cpu
)
5975 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
5977 mminit_verify_zonelist();
5978 cpuset_init_current_mems_allowed();
5982 * unless system_state == SYSTEM_BOOTING.
5984 * __ref due to call of __init annotated helper build_all_zonelists_init
5985 * [protected by SYSTEM_BOOTING].
5987 void __ref
build_all_zonelists(pg_data_t
*pgdat
)
5989 unsigned long vm_total_pages
;
5991 if (system_state
== SYSTEM_BOOTING
) {
5992 build_all_zonelists_init();
5994 __build_all_zonelists(pgdat
);
5995 /* cpuset refresh routine should be here */
5997 /* Get the number of free pages beyond high watermark in all zones. */
5998 vm_total_pages
= nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
6000 * Disable grouping by mobility if the number of pages in the
6001 * system is too low to allow the mechanism to work. It would be
6002 * more accurate, but expensive to check per-zone. This check is
6003 * made on memory-hotadd so a system can start with mobility
6004 * disabled and enable it later
6006 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
6007 page_group_by_mobility_disabled
= 1;
6009 page_group_by_mobility_disabled
= 0;
6011 pr_info("Built %u zonelists, mobility grouping %s. Total pages: %ld\n",
6013 page_group_by_mobility_disabled
? "off" : "on",
6016 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
6020 /* If zone is ZONE_MOVABLE but memory is mirrored, it is an overlapped init */
6021 static bool __meminit
6022 overlap_memmap_init(unsigned long zone
, unsigned long *pfn
)
6024 static struct memblock_region
*r
;
6026 if (mirrored_kernelcore
&& zone
== ZONE_MOVABLE
) {
6027 if (!r
|| *pfn
>= memblock_region_memory_end_pfn(r
)) {
6028 for_each_mem_region(r
) {
6029 if (*pfn
< memblock_region_memory_end_pfn(r
))
6033 if (*pfn
>= memblock_region_memory_base_pfn(r
) &&
6034 memblock_is_mirror(r
)) {
6035 *pfn
= memblock_region_memory_end_pfn(r
);
6043 * Initially all pages are reserved - free ones are freed
6044 * up by memblock_free_all() once the early boot process is
6045 * done. Non-atomic initialization, single-pass.
6047 * All aligned pageblocks are initialized to the specified migratetype
6048 * (usually MIGRATE_MOVABLE). Besides setting the migratetype, no related
6049 * zone stats (e.g., nr_isolate_pageblock) are touched.
6051 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
6052 unsigned long start_pfn
,
6053 enum meminit_context context
,
6054 struct vmem_altmap
*altmap
, int migratetype
)
6056 unsigned long pfn
, end_pfn
= start_pfn
+ size
;
6059 if (highest_memmap_pfn
< end_pfn
- 1)
6060 highest_memmap_pfn
= end_pfn
- 1;
6062 #ifdef CONFIG_ZONE_DEVICE
6064 * Honor reservation requested by the driver for this ZONE_DEVICE
6065 * memory. We limit the total number of pages to initialize to just
6066 * those that might contain the memory mapping. We will defer the
6067 * ZONE_DEVICE page initialization until after we have released
6070 if (zone
== ZONE_DEVICE
) {
6074 if (start_pfn
== altmap
->base_pfn
)
6075 start_pfn
+= altmap
->reserve
;
6076 end_pfn
= altmap
->base_pfn
+ vmem_altmap_offset(altmap
);
6080 for (pfn
= start_pfn
; pfn
< end_pfn
; ) {
6082 * There can be holes in boot-time mem_map[]s handed to this
6083 * function. They do not exist on hotplugged memory.
6085 if (context
== MEMINIT_EARLY
) {
6086 if (overlap_memmap_init(zone
, &pfn
))
6088 if (defer_init(nid
, pfn
, end_pfn
))
6092 page
= pfn_to_page(pfn
);
6093 __init_single_page(page
, pfn
, zone
, nid
);
6094 if (context
== MEMINIT_HOTPLUG
)
6095 __SetPageReserved(page
);
6098 * Usually, we want to mark the pageblock MIGRATE_MOVABLE,
6099 * such that unmovable allocations won't be scattered all
6100 * over the place during system boot.
6102 if (IS_ALIGNED(pfn
, pageblock_nr_pages
)) {
6103 set_pageblock_migratetype(page
, migratetype
);
6110 #ifdef CONFIG_ZONE_DEVICE
6111 void __ref
memmap_init_zone_device(struct zone
*zone
,
6112 unsigned long start_pfn
,
6113 unsigned long nr_pages
,
6114 struct dev_pagemap
*pgmap
)
6116 unsigned long pfn
, end_pfn
= start_pfn
+ nr_pages
;
6117 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
6118 struct vmem_altmap
*altmap
= pgmap_altmap(pgmap
);
6119 unsigned long zone_idx
= zone_idx(zone
);
6120 unsigned long start
= jiffies
;
6121 int nid
= pgdat
->node_id
;
6123 if (WARN_ON_ONCE(!pgmap
|| zone_idx(zone
) != ZONE_DEVICE
))
6127 * The call to memmap_init_zone should have already taken care
6128 * of the pages reserved for the memmap, so we can just jump to
6129 * the end of that region and start processing the device pages.
6132 start_pfn
= altmap
->base_pfn
+ vmem_altmap_offset(altmap
);
6133 nr_pages
= end_pfn
- start_pfn
;
6136 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
6137 struct page
*page
= pfn_to_page(pfn
);
6139 __init_single_page(page
, pfn
, zone_idx
, nid
);
6142 * Mark page reserved as it will need to wait for onlining
6143 * phase for it to be fully associated with a zone.
6145 * We can use the non-atomic __set_bit operation for setting
6146 * the flag as we are still initializing the pages.
6148 __SetPageReserved(page
);
6151 * ZONE_DEVICE pages union ->lru with a ->pgmap back pointer
6152 * and zone_device_data. It is a bug if a ZONE_DEVICE page is
6153 * ever freed or placed on a driver-private list.
6155 page
->pgmap
= pgmap
;
6156 page
->zone_device_data
= NULL
;
6159 * Mark the block movable so that blocks are reserved for
6160 * movable at startup. This will force kernel allocations
6161 * to reserve their blocks rather than leaking throughout
6162 * the address space during boot when many long-lived
6163 * kernel allocations are made.
6165 * Please note that MEMINIT_HOTPLUG path doesn't clear memmap
6166 * because this is done early in section_activate()
6168 if (IS_ALIGNED(pfn
, pageblock_nr_pages
)) {
6169 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
6174 pr_info("%s initialised %lu pages in %ums\n", __func__
,
6175 nr_pages
, jiffies_to_msecs(jiffies
- start
));
6179 static void __meminit
zone_init_free_lists(struct zone
*zone
)
6181 unsigned int order
, t
;
6182 for_each_migratetype_order(order
, t
) {
6183 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
6184 zone
->free_area
[order
].nr_free
= 0;
6188 void __meminit __weak
memmap_init(unsigned long size
, int nid
,
6190 unsigned long range_start_pfn
)
6192 unsigned long start_pfn
, end_pfn
;
6193 unsigned long range_end_pfn
= range_start_pfn
+ size
;
6196 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
6197 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
6198 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
6200 if (end_pfn
> start_pfn
) {
6201 size
= end_pfn
- start_pfn
;
6202 memmap_init_zone(size
, nid
, zone
, start_pfn
,
6203 MEMINIT_EARLY
, NULL
, MIGRATE_MOVABLE
);
6208 static int zone_batchsize(struct zone
*zone
)
6214 * The per-cpu-pages pools are set to around 1000th of the
6217 batch
= zone_managed_pages(zone
) / 1024;
6218 /* But no more than a meg. */
6219 if (batch
* PAGE_SIZE
> 1024 * 1024)
6220 batch
= (1024 * 1024) / PAGE_SIZE
;
6221 batch
/= 4; /* We effectively *= 4 below */
6226 * Clamp the batch to a 2^n - 1 value. Having a power
6227 * of 2 value was found to be more likely to have
6228 * suboptimal cache aliasing properties in some cases.
6230 * For example if 2 tasks are alternately allocating
6231 * batches of pages, one task can end up with a lot
6232 * of pages of one half of the possible page colors
6233 * and the other with pages of the other colors.
6235 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
6240 /* The deferral and batching of frees should be suppressed under NOMMU
6243 * The problem is that NOMMU needs to be able to allocate large chunks
6244 * of contiguous memory as there's no hardware page translation to
6245 * assemble apparent contiguous memory from discontiguous pages.
6247 * Queueing large contiguous runs of pages for batching, however,
6248 * causes the pages to actually be freed in smaller chunks. As there
6249 * can be a significant delay between the individual batches being
6250 * recycled, this leads to the once large chunks of space being
6251 * fragmented and becoming unavailable for high-order allocations.
6258 * pcp->high and pcp->batch values are related and dependent on one another:
6259 * ->batch must never be higher then ->high.
6260 * The following function updates them in a safe manner without read side
6263 * Any new users of pcp->batch and pcp->high should ensure they can cope with
6264 * those fields changing asynchronously (acording to the above rule).
6266 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
6267 * outside of boot time (or some other assurance that no concurrent updaters
6270 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
6271 unsigned long batch
)
6273 /* start with a fail safe value for batch */
6277 /* Update high, then batch, in order */
6284 /* a companion to pageset_set_high() */
6285 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
6287 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
6290 static void pageset_init(struct per_cpu_pageset
*p
)
6292 struct per_cpu_pages
*pcp
;
6295 memset(p
, 0, sizeof(*p
));
6298 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
6299 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
6302 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
6305 pageset_set_batch(p
, batch
);
6309 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
6310 * to the value high for the pageset p.
6312 static void pageset_set_high(struct per_cpu_pageset
*p
,
6315 unsigned long batch
= max(1UL, high
/ 4);
6316 if ((high
/ 4) > (PAGE_SHIFT
* 8))
6317 batch
= PAGE_SHIFT
* 8;
6319 pageset_update(&p
->pcp
, high
, batch
);
6322 static void pageset_set_high_and_batch(struct zone
*zone
,
6323 struct per_cpu_pageset
*pcp
)
6325 if (percpu_pagelist_fraction
)
6326 pageset_set_high(pcp
,
6327 (zone_managed_pages(zone
) /
6328 percpu_pagelist_fraction
));
6330 pageset_set_batch(pcp
, zone_batchsize(zone
));
6333 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
6335 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
6338 pageset_set_high_and_batch(zone
, pcp
);
6341 void __meminit
setup_zone_pageset(struct zone
*zone
)
6344 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
6345 for_each_possible_cpu(cpu
)
6346 zone_pageset_init(zone
, cpu
);
6350 * Allocate per cpu pagesets and initialize them.
6351 * Before this call only boot pagesets were available.
6353 void __init
setup_per_cpu_pageset(void)
6355 struct pglist_data
*pgdat
;
6357 int __maybe_unused cpu
;
6359 for_each_populated_zone(zone
)
6360 setup_zone_pageset(zone
);
6364 * Unpopulated zones continue using the boot pagesets.
6365 * The numa stats for these pagesets need to be reset.
6366 * Otherwise, they will end up skewing the stats of
6367 * the nodes these zones are associated with.
6369 for_each_possible_cpu(cpu
) {
6370 struct per_cpu_pageset
*pcp
= &per_cpu(boot_pageset
, cpu
);
6371 memset(pcp
->vm_numa_stat_diff
, 0,
6372 sizeof(pcp
->vm_numa_stat_diff
));
6376 for_each_online_pgdat(pgdat
)
6377 pgdat
->per_cpu_nodestats
=
6378 alloc_percpu(struct per_cpu_nodestat
);
6381 static __meminit
void zone_pcp_init(struct zone
*zone
)
6384 * per cpu subsystem is not up at this point. The following code
6385 * relies on the ability of the linker to provide the
6386 * offset of a (static) per cpu variable into the per cpu area.
6388 zone
->pageset
= &boot_pageset
;
6390 if (populated_zone(zone
))
6391 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
6392 zone
->name
, zone
->present_pages
,
6393 zone_batchsize(zone
));
6396 void __meminit
init_currently_empty_zone(struct zone
*zone
,
6397 unsigned long zone_start_pfn
,
6400 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
6401 int zone_idx
= zone_idx(zone
) + 1;
6403 if (zone_idx
> pgdat
->nr_zones
)
6404 pgdat
->nr_zones
= zone_idx
;
6406 zone
->zone_start_pfn
= zone_start_pfn
;
6408 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
6409 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
6411 (unsigned long)zone_idx(zone
),
6412 zone_start_pfn
, (zone_start_pfn
+ size
));
6414 zone_init_free_lists(zone
);
6415 zone
->initialized
= 1;
6419 * get_pfn_range_for_nid - Return the start and end page frames for a node
6420 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
6421 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
6422 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
6424 * It returns the start and end page frame of a node based on information
6425 * provided by memblock_set_node(). If called for a node
6426 * with no available memory, a warning is printed and the start and end
6429 void __init
get_pfn_range_for_nid(unsigned int nid
,
6430 unsigned long *start_pfn
, unsigned long *end_pfn
)
6432 unsigned long this_start_pfn
, this_end_pfn
;
6438 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
6439 *start_pfn
= min(*start_pfn
, this_start_pfn
);
6440 *end_pfn
= max(*end_pfn
, this_end_pfn
);
6443 if (*start_pfn
== -1UL)
6448 * This finds a zone that can be used for ZONE_MOVABLE pages. The
6449 * assumption is made that zones within a node are ordered in monotonic
6450 * increasing memory addresses so that the "highest" populated zone is used
6452 static void __init
find_usable_zone_for_movable(void)
6455 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
6456 if (zone_index
== ZONE_MOVABLE
)
6459 if (arch_zone_highest_possible_pfn
[zone_index
] >
6460 arch_zone_lowest_possible_pfn
[zone_index
])
6464 VM_BUG_ON(zone_index
== -1);
6465 movable_zone
= zone_index
;
6469 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
6470 * because it is sized independent of architecture. Unlike the other zones,
6471 * the starting point for ZONE_MOVABLE is not fixed. It may be different
6472 * in each node depending on the size of each node and how evenly kernelcore
6473 * is distributed. This helper function adjusts the zone ranges
6474 * provided by the architecture for a given node by using the end of the
6475 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
6476 * zones within a node are in order of monotonic increases memory addresses
6478 static void __init
adjust_zone_range_for_zone_movable(int nid
,
6479 unsigned long zone_type
,
6480 unsigned long node_start_pfn
,
6481 unsigned long node_end_pfn
,
6482 unsigned long *zone_start_pfn
,
6483 unsigned long *zone_end_pfn
)
6485 /* Only adjust if ZONE_MOVABLE is on this node */
6486 if (zone_movable_pfn
[nid
]) {
6487 /* Size ZONE_MOVABLE */
6488 if (zone_type
== ZONE_MOVABLE
) {
6489 *zone_start_pfn
= zone_movable_pfn
[nid
];
6490 *zone_end_pfn
= min(node_end_pfn
,
6491 arch_zone_highest_possible_pfn
[movable_zone
]);
6493 /* Adjust for ZONE_MOVABLE starting within this range */
6494 } else if (!mirrored_kernelcore
&&
6495 *zone_start_pfn
< zone_movable_pfn
[nid
] &&
6496 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
6497 *zone_end_pfn
= zone_movable_pfn
[nid
];
6499 /* Check if this whole range is within ZONE_MOVABLE */
6500 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
6501 *zone_start_pfn
= *zone_end_pfn
;
6506 * Return the number of pages a zone spans in a node, including holes
6507 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
6509 static unsigned long __init
zone_spanned_pages_in_node(int nid
,
6510 unsigned long zone_type
,
6511 unsigned long node_start_pfn
,
6512 unsigned long node_end_pfn
,
6513 unsigned long *zone_start_pfn
,
6514 unsigned long *zone_end_pfn
)
6516 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
6517 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
6518 /* When hotadd a new node from cpu_up(), the node should be empty */
6519 if (!node_start_pfn
&& !node_end_pfn
)
6522 /* Get the start and end of the zone */
6523 *zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
6524 *zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
6525 adjust_zone_range_for_zone_movable(nid
, zone_type
,
6526 node_start_pfn
, node_end_pfn
,
6527 zone_start_pfn
, zone_end_pfn
);
6529 /* Check that this node has pages within the zone's required range */
6530 if (*zone_end_pfn
< node_start_pfn
|| *zone_start_pfn
> node_end_pfn
)
6533 /* Move the zone boundaries inside the node if necessary */
6534 *zone_end_pfn
= min(*zone_end_pfn
, node_end_pfn
);
6535 *zone_start_pfn
= max(*zone_start_pfn
, node_start_pfn
);
6537 /* Return the spanned pages */
6538 return *zone_end_pfn
- *zone_start_pfn
;
6542 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
6543 * then all holes in the requested range will be accounted for.
6545 unsigned long __init
__absent_pages_in_range(int nid
,
6546 unsigned long range_start_pfn
,
6547 unsigned long range_end_pfn
)
6549 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
6550 unsigned long start_pfn
, end_pfn
;
6553 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
6554 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
6555 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
6556 nr_absent
-= end_pfn
- start_pfn
;
6562 * absent_pages_in_range - Return number of page frames in holes within a range
6563 * @start_pfn: The start PFN to start searching for holes
6564 * @end_pfn: The end PFN to stop searching for holes
6566 * Return: the number of pages frames in memory holes within a range.
6568 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
6569 unsigned long end_pfn
)
6571 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
6574 /* Return the number of page frames in holes in a zone on a node */
6575 static unsigned long __init
zone_absent_pages_in_node(int nid
,
6576 unsigned long zone_type
,
6577 unsigned long node_start_pfn
,
6578 unsigned long node_end_pfn
)
6580 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
6581 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
6582 unsigned long zone_start_pfn
, zone_end_pfn
;
6583 unsigned long nr_absent
;
6585 /* When hotadd a new node from cpu_up(), the node should be empty */
6586 if (!node_start_pfn
&& !node_end_pfn
)
6589 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
6590 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
6592 adjust_zone_range_for_zone_movable(nid
, zone_type
,
6593 node_start_pfn
, node_end_pfn
,
6594 &zone_start_pfn
, &zone_end_pfn
);
6595 nr_absent
= __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
6598 * ZONE_MOVABLE handling.
6599 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
6602 if (mirrored_kernelcore
&& zone_movable_pfn
[nid
]) {
6603 unsigned long start_pfn
, end_pfn
;
6604 struct memblock_region
*r
;
6606 for_each_mem_region(r
) {
6607 start_pfn
= clamp(memblock_region_memory_base_pfn(r
),
6608 zone_start_pfn
, zone_end_pfn
);
6609 end_pfn
= clamp(memblock_region_memory_end_pfn(r
),
6610 zone_start_pfn
, zone_end_pfn
);
6612 if (zone_type
== ZONE_MOVABLE
&&
6613 memblock_is_mirror(r
))
6614 nr_absent
+= end_pfn
- start_pfn
;
6616 if (zone_type
== ZONE_NORMAL
&&
6617 !memblock_is_mirror(r
))
6618 nr_absent
+= end_pfn
- start_pfn
;
6625 static void __init
calculate_node_totalpages(struct pglist_data
*pgdat
,
6626 unsigned long node_start_pfn
,
6627 unsigned long node_end_pfn
)
6629 unsigned long realtotalpages
= 0, totalpages
= 0;
6632 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6633 struct zone
*zone
= pgdat
->node_zones
+ i
;
6634 unsigned long zone_start_pfn
, zone_end_pfn
;
6635 unsigned long spanned
, absent
;
6636 unsigned long size
, real_size
;
6638 spanned
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
6643 absent
= zone_absent_pages_in_node(pgdat
->node_id
, i
,
6648 real_size
= size
- absent
;
6651 zone
->zone_start_pfn
= zone_start_pfn
;
6653 zone
->zone_start_pfn
= 0;
6654 zone
->spanned_pages
= size
;
6655 zone
->present_pages
= real_size
;
6658 realtotalpages
+= real_size
;
6661 pgdat
->node_spanned_pages
= totalpages
;
6662 pgdat
->node_present_pages
= realtotalpages
;
6663 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
6667 #ifndef CONFIG_SPARSEMEM
6669 * Calculate the size of the zone->blockflags rounded to an unsigned long
6670 * Start by making sure zonesize is a multiple of pageblock_order by rounding
6671 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
6672 * round what is now in bits to nearest long in bits, then return it in
6675 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
6677 unsigned long usemapsize
;
6679 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
6680 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
6681 usemapsize
= usemapsize
>> pageblock_order
;
6682 usemapsize
*= NR_PAGEBLOCK_BITS
;
6683 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
6685 return usemapsize
/ 8;
6688 static void __ref
setup_usemap(struct pglist_data
*pgdat
,
6690 unsigned long zone_start_pfn
,
6691 unsigned long zonesize
)
6693 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
6694 zone
->pageblock_flags
= NULL
;
6696 zone
->pageblock_flags
=
6697 memblock_alloc_node(usemapsize
, SMP_CACHE_BYTES
,
6699 if (!zone
->pageblock_flags
)
6700 panic("Failed to allocate %ld bytes for zone %s pageblock flags on node %d\n",
6701 usemapsize
, zone
->name
, pgdat
->node_id
);
6705 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
6706 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
6707 #endif /* CONFIG_SPARSEMEM */
6709 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
6711 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
6712 void __init
set_pageblock_order(void)
6716 /* Check that pageblock_nr_pages has not already been setup */
6717 if (pageblock_order
)
6720 if (HPAGE_SHIFT
> PAGE_SHIFT
)
6721 order
= HUGETLB_PAGE_ORDER
;
6723 order
= MAX_ORDER
- 1;
6726 * Assume the largest contiguous order of interest is a huge page.
6727 * This value may be variable depending on boot parameters on IA64 and
6730 pageblock_order
= order
;
6732 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6735 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
6736 * is unused as pageblock_order is set at compile-time. See
6737 * include/linux/pageblock-flags.h for the values of pageblock_order based on
6740 void __init
set_pageblock_order(void)
6744 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6746 static unsigned long __init
calc_memmap_size(unsigned long spanned_pages
,
6747 unsigned long present_pages
)
6749 unsigned long pages
= spanned_pages
;
6752 * Provide a more accurate estimation if there are holes within
6753 * the zone and SPARSEMEM is in use. If there are holes within the
6754 * zone, each populated memory region may cost us one or two extra
6755 * memmap pages due to alignment because memmap pages for each
6756 * populated regions may not be naturally aligned on page boundary.
6757 * So the (present_pages >> 4) heuristic is a tradeoff for that.
6759 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
6760 IS_ENABLED(CONFIG_SPARSEMEM
))
6761 pages
= present_pages
;
6763 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
6766 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6767 static void pgdat_init_split_queue(struct pglist_data
*pgdat
)
6769 struct deferred_split
*ds_queue
= &pgdat
->deferred_split_queue
;
6771 spin_lock_init(&ds_queue
->split_queue_lock
);
6772 INIT_LIST_HEAD(&ds_queue
->split_queue
);
6773 ds_queue
->split_queue_len
= 0;
6776 static void pgdat_init_split_queue(struct pglist_data
*pgdat
) {}
6779 #ifdef CONFIG_COMPACTION
6780 static void pgdat_init_kcompactd(struct pglist_data
*pgdat
)
6782 init_waitqueue_head(&pgdat
->kcompactd_wait
);
6785 static void pgdat_init_kcompactd(struct pglist_data
*pgdat
) {}
6788 static void __meminit
pgdat_init_internals(struct pglist_data
*pgdat
)
6790 pgdat_resize_init(pgdat
);
6792 pgdat_init_split_queue(pgdat
);
6793 pgdat_init_kcompactd(pgdat
);
6795 init_waitqueue_head(&pgdat
->kswapd_wait
);
6796 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
6798 pgdat_page_ext_init(pgdat
);
6799 spin_lock_init(&pgdat
->lru_lock
);
6800 lruvec_init(&pgdat
->__lruvec
);
6803 static void __meminit
zone_init_internals(struct zone
*zone
, enum zone_type idx
, int nid
,
6804 unsigned long remaining_pages
)
6806 atomic_long_set(&zone
->managed_pages
, remaining_pages
);
6807 zone_set_nid(zone
, nid
);
6808 zone
->name
= zone_names
[idx
];
6809 zone
->zone_pgdat
= NODE_DATA(nid
);
6810 spin_lock_init(&zone
->lock
);
6811 zone_seqlock_init(zone
);
6812 zone_pcp_init(zone
);
6816 * Set up the zone data structures
6817 * - init pgdat internals
6818 * - init all zones belonging to this node
6820 * NOTE: this function is only called during memory hotplug
6822 #ifdef CONFIG_MEMORY_HOTPLUG
6823 void __ref
free_area_init_core_hotplug(int nid
)
6826 pg_data_t
*pgdat
= NODE_DATA(nid
);
6828 pgdat_init_internals(pgdat
);
6829 for (z
= 0; z
< MAX_NR_ZONES
; z
++)
6830 zone_init_internals(&pgdat
->node_zones
[z
], z
, nid
, 0);
6835 * Set up the zone data structures:
6836 * - mark all pages reserved
6837 * - mark all memory queues empty
6838 * - clear the memory bitmaps
6840 * NOTE: pgdat should get zeroed by caller.
6841 * NOTE: this function is only called during early init.
6843 static void __init
free_area_init_core(struct pglist_data
*pgdat
)
6846 int nid
= pgdat
->node_id
;
6848 pgdat_init_internals(pgdat
);
6849 pgdat
->per_cpu_nodestats
= &boot_nodestats
;
6851 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6852 struct zone
*zone
= pgdat
->node_zones
+ j
;
6853 unsigned long size
, freesize
, memmap_pages
;
6854 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
6856 size
= zone
->spanned_pages
;
6857 freesize
= zone
->present_pages
;
6860 * Adjust freesize so that it accounts for how much memory
6861 * is used by this zone for memmap. This affects the watermark
6862 * and per-cpu initialisations
6864 memmap_pages
= calc_memmap_size(size
, freesize
);
6865 if (!is_highmem_idx(j
)) {
6866 if (freesize
>= memmap_pages
) {
6867 freesize
-= memmap_pages
;
6870 " %s zone: %lu pages used for memmap\n",
6871 zone_names
[j
], memmap_pages
);
6873 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
6874 zone_names
[j
], memmap_pages
, freesize
);
6877 /* Account for reserved pages */
6878 if (j
== 0 && freesize
> dma_reserve
) {
6879 freesize
-= dma_reserve
;
6880 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
6881 zone_names
[0], dma_reserve
);
6884 if (!is_highmem_idx(j
))
6885 nr_kernel_pages
+= freesize
;
6886 /* Charge for highmem memmap if there are enough kernel pages */
6887 else if (nr_kernel_pages
> memmap_pages
* 2)
6888 nr_kernel_pages
-= memmap_pages
;
6889 nr_all_pages
+= freesize
;
6892 * Set an approximate value for lowmem here, it will be adjusted
6893 * when the bootmem allocator frees pages into the buddy system.
6894 * And all highmem pages will be managed by the buddy system.
6896 zone_init_internals(zone
, j
, nid
, freesize
);
6901 set_pageblock_order();
6902 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
6903 init_currently_empty_zone(zone
, zone_start_pfn
, size
);
6904 memmap_init(size
, nid
, j
, zone_start_pfn
);
6908 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6909 static void __ref
alloc_node_mem_map(struct pglist_data
*pgdat
)
6911 unsigned long __maybe_unused start
= 0;
6912 unsigned long __maybe_unused offset
= 0;
6914 /* Skip empty nodes */
6915 if (!pgdat
->node_spanned_pages
)
6918 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
6919 offset
= pgdat
->node_start_pfn
- start
;
6920 /* ia64 gets its own node_mem_map, before this, without bootmem */
6921 if (!pgdat
->node_mem_map
) {
6922 unsigned long size
, end
;
6926 * The zone's endpoints aren't required to be MAX_ORDER
6927 * aligned but the node_mem_map endpoints must be in order
6928 * for the buddy allocator to function correctly.
6930 end
= pgdat_end_pfn(pgdat
);
6931 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
6932 size
= (end
- start
) * sizeof(struct page
);
6933 map
= memblock_alloc_node(size
, SMP_CACHE_BYTES
,
6936 panic("Failed to allocate %ld bytes for node %d memory map\n",
6937 size
, pgdat
->node_id
);
6938 pgdat
->node_mem_map
= map
+ offset
;
6940 pr_debug("%s: node %d, pgdat %08lx, node_mem_map %08lx\n",
6941 __func__
, pgdat
->node_id
, (unsigned long)pgdat
,
6942 (unsigned long)pgdat
->node_mem_map
);
6943 #ifndef CONFIG_NEED_MULTIPLE_NODES
6945 * With no DISCONTIG, the global mem_map is just set as node 0's
6947 if (pgdat
== NODE_DATA(0)) {
6948 mem_map
= NODE_DATA(0)->node_mem_map
;
6949 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
6955 static void __ref
alloc_node_mem_map(struct pglist_data
*pgdat
) { }
6956 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
6958 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
6959 static inline void pgdat_set_deferred_range(pg_data_t
*pgdat
)
6961 pgdat
->first_deferred_pfn
= ULONG_MAX
;
6964 static inline void pgdat_set_deferred_range(pg_data_t
*pgdat
) {}
6967 static void __init
free_area_init_node(int nid
)
6969 pg_data_t
*pgdat
= NODE_DATA(nid
);
6970 unsigned long start_pfn
= 0;
6971 unsigned long end_pfn
= 0;
6973 /* pg_data_t should be reset to zero when it's allocated */
6974 WARN_ON(pgdat
->nr_zones
|| pgdat
->kswapd_highest_zoneidx
);
6976 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
6978 pgdat
->node_id
= nid
;
6979 pgdat
->node_start_pfn
= start_pfn
;
6980 pgdat
->per_cpu_nodestats
= NULL
;
6982 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
6983 (u64
)start_pfn
<< PAGE_SHIFT
,
6984 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
6985 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
);
6987 alloc_node_mem_map(pgdat
);
6988 pgdat_set_deferred_range(pgdat
);
6990 free_area_init_core(pgdat
);
6993 void __init
free_area_init_memoryless_node(int nid
)
6995 free_area_init_node(nid
);
6998 #if !defined(CONFIG_FLAT_NODE_MEM_MAP)
7000 * Initialize all valid struct pages in the range [spfn, epfn) and mark them
7001 * PageReserved(). Return the number of struct pages that were initialized.
7003 static u64 __init
init_unavailable_range(unsigned long spfn
, unsigned long epfn
)
7008 for (pfn
= spfn
; pfn
< epfn
; pfn
++) {
7009 if (!pfn_valid(ALIGN_DOWN(pfn
, pageblock_nr_pages
))) {
7010 pfn
= ALIGN_DOWN(pfn
, pageblock_nr_pages
)
7011 + pageblock_nr_pages
- 1;
7015 * Use a fake node/zone (0) for now. Some of these pages
7016 * (in memblock.reserved but not in memblock.memory) will
7017 * get re-initialized via reserve_bootmem_region() later.
7019 __init_single_page(pfn_to_page(pfn
), pfn
, 0, 0);
7020 __SetPageReserved(pfn_to_page(pfn
));
7028 * Only struct pages that are backed by physical memory are zeroed and
7029 * initialized by going through __init_single_page(). But, there are some
7030 * struct pages which are reserved in memblock allocator and their fields
7031 * may be accessed (for example page_to_pfn() on some configuration accesses
7032 * flags). We must explicitly initialize those struct pages.
7034 * This function also addresses a similar issue where struct pages are left
7035 * uninitialized because the physical address range is not covered by
7036 * memblock.memory or memblock.reserved. That could happen when memblock
7037 * layout is manually configured via memmap=, or when the highest physical
7038 * address (max_pfn) does not end on a section boundary.
7040 static void __init
init_unavailable_mem(void)
7042 phys_addr_t start
, end
;
7044 phys_addr_t next
= 0;
7047 * Loop through unavailable ranges not covered by memblock.memory.
7050 for_each_mem_range(i
, &start
, &end
) {
7052 pgcnt
+= init_unavailable_range(PFN_DOWN(next
),
7058 * Early sections always have a fully populated memmap for the whole
7059 * section - see pfn_valid(). If the last section has holes at the
7060 * end and that section is marked "online", the memmap will be
7061 * considered initialized. Make sure that memmap has a well defined
7064 pgcnt
+= init_unavailable_range(PFN_DOWN(next
),
7065 round_up(max_pfn
, PAGES_PER_SECTION
));
7068 * Struct pages that do not have backing memory. This could be because
7069 * firmware is using some of this memory, or for some other reasons.
7072 pr_info("Zeroed struct page in unavailable ranges: %lld pages", pgcnt
);
7075 static inline void __init
init_unavailable_mem(void)
7078 #endif /* !CONFIG_FLAT_NODE_MEM_MAP */
7080 #if MAX_NUMNODES > 1
7082 * Figure out the number of possible node ids.
7084 void __init
setup_nr_node_ids(void)
7086 unsigned int highest
;
7088 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
7089 nr_node_ids
= highest
+ 1;
7094 * node_map_pfn_alignment - determine the maximum internode alignment
7096 * This function should be called after node map is populated and sorted.
7097 * It calculates the maximum power of two alignment which can distinguish
7100 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
7101 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
7102 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
7103 * shifted, 1GiB is enough and this function will indicate so.
7105 * This is used to test whether pfn -> nid mapping of the chosen memory
7106 * model has fine enough granularity to avoid incorrect mapping for the
7107 * populated node map.
7109 * Return: the determined alignment in pfn's. 0 if there is no alignment
7110 * requirement (single node).
7112 unsigned long __init
node_map_pfn_alignment(void)
7114 unsigned long accl_mask
= 0, last_end
= 0;
7115 unsigned long start
, end
, mask
;
7116 int last_nid
= NUMA_NO_NODE
;
7119 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
7120 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
7127 * Start with a mask granular enough to pin-point to the
7128 * start pfn and tick off bits one-by-one until it becomes
7129 * too coarse to separate the current node from the last.
7131 mask
= ~((1 << __ffs(start
)) - 1);
7132 while (mask
&& last_end
<= (start
& (mask
<< 1)))
7135 /* accumulate all internode masks */
7139 /* convert mask to number of pages */
7140 return ~accl_mask
+ 1;
7144 * find_min_pfn_with_active_regions - Find the minimum PFN registered
7146 * Return: the minimum PFN based on information provided via
7147 * memblock_set_node().
7149 unsigned long __init
find_min_pfn_with_active_regions(void)
7151 return PHYS_PFN(memblock_start_of_DRAM());
7155 * early_calculate_totalpages()
7156 * Sum pages in active regions for movable zone.
7157 * Populate N_MEMORY for calculating usable_nodes.
7159 static unsigned long __init
early_calculate_totalpages(void)
7161 unsigned long totalpages
= 0;
7162 unsigned long start_pfn
, end_pfn
;
7165 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
7166 unsigned long pages
= end_pfn
- start_pfn
;
7168 totalpages
+= pages
;
7170 node_set_state(nid
, N_MEMORY
);
7176 * Find the PFN the Movable zone begins in each node. Kernel memory
7177 * is spread evenly between nodes as long as the nodes have enough
7178 * memory. When they don't, some nodes will have more kernelcore than
7181 static void __init
find_zone_movable_pfns_for_nodes(void)
7184 unsigned long usable_startpfn
;
7185 unsigned long kernelcore_node
, kernelcore_remaining
;
7186 /* save the state before borrow the nodemask */
7187 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
7188 unsigned long totalpages
= early_calculate_totalpages();
7189 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
7190 struct memblock_region
*r
;
7192 /* Need to find movable_zone earlier when movable_node is specified. */
7193 find_usable_zone_for_movable();
7196 * If movable_node is specified, ignore kernelcore and movablecore
7199 if (movable_node_is_enabled()) {
7200 for_each_mem_region(r
) {
7201 if (!memblock_is_hotpluggable(r
))
7204 nid
= memblock_get_region_node(r
);
7206 usable_startpfn
= PFN_DOWN(r
->base
);
7207 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
7208 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
7216 * If kernelcore=mirror is specified, ignore movablecore option
7218 if (mirrored_kernelcore
) {
7219 bool mem_below_4gb_not_mirrored
= false;
7221 for_each_mem_region(r
) {
7222 if (memblock_is_mirror(r
))
7225 nid
= memblock_get_region_node(r
);
7227 usable_startpfn
= memblock_region_memory_base_pfn(r
);
7229 if (usable_startpfn
< 0x100000) {
7230 mem_below_4gb_not_mirrored
= true;
7234 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
7235 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
7239 if (mem_below_4gb_not_mirrored
)
7240 pr_warn("This configuration results in unmirrored kernel memory.\n");
7246 * If kernelcore=nn% or movablecore=nn% was specified, calculate the
7247 * amount of necessary memory.
7249 if (required_kernelcore_percent
)
7250 required_kernelcore
= (totalpages
* 100 * required_kernelcore_percent
) /
7252 if (required_movablecore_percent
)
7253 required_movablecore
= (totalpages
* 100 * required_movablecore_percent
) /
7257 * If movablecore= was specified, calculate what size of
7258 * kernelcore that corresponds so that memory usable for
7259 * any allocation type is evenly spread. If both kernelcore
7260 * and movablecore are specified, then the value of kernelcore
7261 * will be used for required_kernelcore if it's greater than
7262 * what movablecore would have allowed.
7264 if (required_movablecore
) {
7265 unsigned long corepages
;
7268 * Round-up so that ZONE_MOVABLE is at least as large as what
7269 * was requested by the user
7271 required_movablecore
=
7272 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
7273 required_movablecore
= min(totalpages
, required_movablecore
);
7274 corepages
= totalpages
- required_movablecore
;
7276 required_kernelcore
= max(required_kernelcore
, corepages
);
7280 * If kernelcore was not specified or kernelcore size is larger
7281 * than totalpages, there is no ZONE_MOVABLE.
7283 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
7286 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
7287 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
7290 /* Spread kernelcore memory as evenly as possible throughout nodes */
7291 kernelcore_node
= required_kernelcore
/ usable_nodes
;
7292 for_each_node_state(nid
, N_MEMORY
) {
7293 unsigned long start_pfn
, end_pfn
;
7296 * Recalculate kernelcore_node if the division per node
7297 * now exceeds what is necessary to satisfy the requested
7298 * amount of memory for the kernel
7300 if (required_kernelcore
< kernelcore_node
)
7301 kernelcore_node
= required_kernelcore
/ usable_nodes
;
7304 * As the map is walked, we track how much memory is usable
7305 * by the kernel using kernelcore_remaining. When it is
7306 * 0, the rest of the node is usable by ZONE_MOVABLE
7308 kernelcore_remaining
= kernelcore_node
;
7310 /* Go through each range of PFNs within this node */
7311 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
7312 unsigned long size_pages
;
7314 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
7315 if (start_pfn
>= end_pfn
)
7318 /* Account for what is only usable for kernelcore */
7319 if (start_pfn
< usable_startpfn
) {
7320 unsigned long kernel_pages
;
7321 kernel_pages
= min(end_pfn
, usable_startpfn
)
7324 kernelcore_remaining
-= min(kernel_pages
,
7325 kernelcore_remaining
);
7326 required_kernelcore
-= min(kernel_pages
,
7327 required_kernelcore
);
7329 /* Continue if range is now fully accounted */
7330 if (end_pfn
<= usable_startpfn
) {
7333 * Push zone_movable_pfn to the end so
7334 * that if we have to rebalance
7335 * kernelcore across nodes, we will
7336 * not double account here
7338 zone_movable_pfn
[nid
] = end_pfn
;
7341 start_pfn
= usable_startpfn
;
7345 * The usable PFN range for ZONE_MOVABLE is from
7346 * start_pfn->end_pfn. Calculate size_pages as the
7347 * number of pages used as kernelcore
7349 size_pages
= end_pfn
- start_pfn
;
7350 if (size_pages
> kernelcore_remaining
)
7351 size_pages
= kernelcore_remaining
;
7352 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
7355 * Some kernelcore has been met, update counts and
7356 * break if the kernelcore for this node has been
7359 required_kernelcore
-= min(required_kernelcore
,
7361 kernelcore_remaining
-= size_pages
;
7362 if (!kernelcore_remaining
)
7368 * If there is still required_kernelcore, we do another pass with one
7369 * less node in the count. This will push zone_movable_pfn[nid] further
7370 * along on the nodes that still have memory until kernelcore is
7374 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
7378 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
7379 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
7380 zone_movable_pfn
[nid
] =
7381 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
7384 /* restore the node_state */
7385 node_states
[N_MEMORY
] = saved_node_state
;
7388 /* Any regular or high memory on that node ? */
7389 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
7391 enum zone_type zone_type
;
7393 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
7394 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
7395 if (populated_zone(zone
)) {
7396 if (IS_ENABLED(CONFIG_HIGHMEM
))
7397 node_set_state(nid
, N_HIGH_MEMORY
);
7398 if (zone_type
<= ZONE_NORMAL
)
7399 node_set_state(nid
, N_NORMAL_MEMORY
);
7406 * Some architecturs, e.g. ARC may have ZONE_HIGHMEM below ZONE_NORMAL. For
7407 * such cases we allow max_zone_pfn sorted in the descending order
7409 bool __weak
arch_has_descending_max_zone_pfns(void)
7415 * free_area_init - Initialise all pg_data_t and zone data
7416 * @max_zone_pfn: an array of max PFNs for each zone
7418 * This will call free_area_init_node() for each active node in the system.
7419 * Using the page ranges provided by memblock_set_node(), the size of each
7420 * zone in each node and their holes is calculated. If the maximum PFN
7421 * between two adjacent zones match, it is assumed that the zone is empty.
7422 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
7423 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
7424 * starts where the previous one ended. For example, ZONE_DMA32 starts
7425 * at arch_max_dma_pfn.
7427 void __init
free_area_init(unsigned long *max_zone_pfn
)
7429 unsigned long start_pfn
, end_pfn
;
7433 /* Record where the zone boundaries are */
7434 memset(arch_zone_lowest_possible_pfn
, 0,
7435 sizeof(arch_zone_lowest_possible_pfn
));
7436 memset(arch_zone_highest_possible_pfn
, 0,
7437 sizeof(arch_zone_highest_possible_pfn
));
7439 start_pfn
= find_min_pfn_with_active_regions();
7440 descending
= arch_has_descending_max_zone_pfns();
7442 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
7444 zone
= MAX_NR_ZONES
- i
- 1;
7448 if (zone
== ZONE_MOVABLE
)
7451 end_pfn
= max(max_zone_pfn
[zone
], start_pfn
);
7452 arch_zone_lowest_possible_pfn
[zone
] = start_pfn
;
7453 arch_zone_highest_possible_pfn
[zone
] = end_pfn
;
7455 start_pfn
= end_pfn
;
7458 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
7459 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
7460 find_zone_movable_pfns_for_nodes();
7462 /* Print out the zone ranges */
7463 pr_info("Zone ranges:\n");
7464 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
7465 if (i
== ZONE_MOVABLE
)
7467 pr_info(" %-8s ", zone_names
[i
]);
7468 if (arch_zone_lowest_possible_pfn
[i
] ==
7469 arch_zone_highest_possible_pfn
[i
])
7472 pr_cont("[mem %#018Lx-%#018Lx]\n",
7473 (u64
)arch_zone_lowest_possible_pfn
[i
]
7475 ((u64
)arch_zone_highest_possible_pfn
[i
]
7476 << PAGE_SHIFT
) - 1);
7479 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
7480 pr_info("Movable zone start for each node\n");
7481 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
7482 if (zone_movable_pfn
[i
])
7483 pr_info(" Node %d: %#018Lx\n", i
,
7484 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
7488 * Print out the early node map, and initialize the
7489 * subsection-map relative to active online memory ranges to
7490 * enable future "sub-section" extensions of the memory map.
7492 pr_info("Early memory node ranges\n");
7493 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
7494 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
7495 (u64
)start_pfn
<< PAGE_SHIFT
,
7496 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
7497 subsection_map_init(start_pfn
, end_pfn
- start_pfn
);
7500 /* Initialise every node */
7501 mminit_verify_pageflags_layout();
7502 setup_nr_node_ids();
7503 init_unavailable_mem();
7504 for_each_online_node(nid
) {
7505 pg_data_t
*pgdat
= NODE_DATA(nid
);
7506 free_area_init_node(nid
);
7508 /* Any memory on that node */
7509 if (pgdat
->node_present_pages
)
7510 node_set_state(nid
, N_MEMORY
);
7511 check_for_memory(pgdat
, nid
);
7515 static int __init
cmdline_parse_core(char *p
, unsigned long *core
,
7516 unsigned long *percent
)
7518 unsigned long long coremem
;
7524 /* Value may be a percentage of total memory, otherwise bytes */
7525 coremem
= simple_strtoull(p
, &endptr
, 0);
7526 if (*endptr
== '%') {
7527 /* Paranoid check for percent values greater than 100 */
7528 WARN_ON(coremem
> 100);
7532 coremem
= memparse(p
, &p
);
7533 /* Paranoid check that UL is enough for the coremem value */
7534 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
7536 *core
= coremem
>> PAGE_SHIFT
;
7543 * kernelcore=size sets the amount of memory for use for allocations that
7544 * cannot be reclaimed or migrated.
7546 static int __init
cmdline_parse_kernelcore(char *p
)
7548 /* parse kernelcore=mirror */
7549 if (parse_option_str(p
, "mirror")) {
7550 mirrored_kernelcore
= true;
7554 return cmdline_parse_core(p
, &required_kernelcore
,
7555 &required_kernelcore_percent
);
7559 * movablecore=size sets the amount of memory for use for allocations that
7560 * can be reclaimed or migrated.
7562 static int __init
cmdline_parse_movablecore(char *p
)
7564 return cmdline_parse_core(p
, &required_movablecore
,
7565 &required_movablecore_percent
);
7568 early_param("kernelcore", cmdline_parse_kernelcore
);
7569 early_param("movablecore", cmdline_parse_movablecore
);
7571 void adjust_managed_page_count(struct page
*page
, long count
)
7573 atomic_long_add(count
, &page_zone(page
)->managed_pages
);
7574 totalram_pages_add(count
);
7575 #ifdef CONFIG_HIGHMEM
7576 if (PageHighMem(page
))
7577 totalhigh_pages_add(count
);
7580 EXPORT_SYMBOL(adjust_managed_page_count
);
7582 unsigned long free_reserved_area(void *start
, void *end
, int poison
, const char *s
)
7585 unsigned long pages
= 0;
7587 start
= (void *)PAGE_ALIGN((unsigned long)start
);
7588 end
= (void *)((unsigned long)end
& PAGE_MASK
);
7589 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
7590 struct page
*page
= virt_to_page(pos
);
7591 void *direct_map_addr
;
7594 * 'direct_map_addr' might be different from 'pos'
7595 * because some architectures' virt_to_page()
7596 * work with aliases. Getting the direct map
7597 * address ensures that we get a _writeable_
7598 * alias for the memset().
7600 direct_map_addr
= page_address(page
);
7601 if ((unsigned int)poison
<= 0xFF)
7602 memset(direct_map_addr
, poison
, PAGE_SIZE
);
7604 free_reserved_page(page
);
7608 pr_info("Freeing %s memory: %ldK\n",
7609 s
, pages
<< (PAGE_SHIFT
- 10));
7614 #ifdef CONFIG_HIGHMEM
7615 void free_highmem_page(struct page
*page
)
7617 __free_reserved_page(page
);
7618 totalram_pages_inc();
7619 atomic_long_inc(&page_zone(page
)->managed_pages
);
7620 totalhigh_pages_inc();
7625 void __init
mem_init_print_info(const char *str
)
7627 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
7628 unsigned long init_code_size
, init_data_size
;
7630 physpages
= get_num_physpages();
7631 codesize
= _etext
- _stext
;
7632 datasize
= _edata
- _sdata
;
7633 rosize
= __end_rodata
- __start_rodata
;
7634 bss_size
= __bss_stop
- __bss_start
;
7635 init_data_size
= __init_end
- __init_begin
;
7636 init_code_size
= _einittext
- _sinittext
;
7639 * Detect special cases and adjust section sizes accordingly:
7640 * 1) .init.* may be embedded into .data sections
7641 * 2) .init.text.* may be out of [__init_begin, __init_end],
7642 * please refer to arch/tile/kernel/vmlinux.lds.S.
7643 * 3) .rodata.* may be embedded into .text or .data sections.
7645 #define adj_init_size(start, end, size, pos, adj) \
7647 if (start <= pos && pos < end && size > adj) \
7651 adj_init_size(__init_begin
, __init_end
, init_data_size
,
7652 _sinittext
, init_code_size
);
7653 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
7654 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
7655 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
7656 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
7658 #undef adj_init_size
7660 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
7661 #ifdef CONFIG_HIGHMEM
7665 nr_free_pages() << (PAGE_SHIFT
- 10),
7666 physpages
<< (PAGE_SHIFT
- 10),
7667 codesize
>> 10, datasize
>> 10, rosize
>> 10,
7668 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
7669 (physpages
- totalram_pages() - totalcma_pages
) << (PAGE_SHIFT
- 10),
7670 totalcma_pages
<< (PAGE_SHIFT
- 10),
7671 #ifdef CONFIG_HIGHMEM
7672 totalhigh_pages() << (PAGE_SHIFT
- 10),
7674 str
? ", " : "", str
? str
: "");
7678 * set_dma_reserve - set the specified number of pages reserved in the first zone
7679 * @new_dma_reserve: The number of pages to mark reserved
7681 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
7682 * In the DMA zone, a significant percentage may be consumed by kernel image
7683 * and other unfreeable allocations which can skew the watermarks badly. This
7684 * function may optionally be used to account for unfreeable pages in the
7685 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
7686 * smaller per-cpu batchsize.
7688 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
7690 dma_reserve
= new_dma_reserve
;
7693 static int page_alloc_cpu_dead(unsigned int cpu
)
7696 lru_add_drain_cpu(cpu
);
7700 * Spill the event counters of the dead processor
7701 * into the current processors event counters.
7702 * This artificially elevates the count of the current
7705 vm_events_fold_cpu(cpu
);
7708 * Zero the differential counters of the dead processor
7709 * so that the vm statistics are consistent.
7711 * This is only okay since the processor is dead and cannot
7712 * race with what we are doing.
7714 cpu_vm_stats_fold(cpu
);
7719 int hashdist
= HASHDIST_DEFAULT
;
7721 static int __init
set_hashdist(char *str
)
7725 hashdist
= simple_strtoul(str
, &str
, 0);
7728 __setup("hashdist=", set_hashdist
);
7731 void __init
page_alloc_init(void)
7736 if (num_node_state(N_MEMORY
) == 1)
7740 ret
= cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC_DEAD
,
7741 "mm/page_alloc:dead", NULL
,
7742 page_alloc_cpu_dead
);
7747 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
7748 * or min_free_kbytes changes.
7750 static void calculate_totalreserve_pages(void)
7752 struct pglist_data
*pgdat
;
7753 unsigned long reserve_pages
= 0;
7754 enum zone_type i
, j
;
7756 for_each_online_pgdat(pgdat
) {
7758 pgdat
->totalreserve_pages
= 0;
7760 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
7761 struct zone
*zone
= pgdat
->node_zones
+ i
;
7763 unsigned long managed_pages
= zone_managed_pages(zone
);
7765 /* Find valid and maximum lowmem_reserve in the zone */
7766 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
7767 if (zone
->lowmem_reserve
[j
] > max
)
7768 max
= zone
->lowmem_reserve
[j
];
7771 /* we treat the high watermark as reserved pages. */
7772 max
+= high_wmark_pages(zone
);
7774 if (max
> managed_pages
)
7775 max
= managed_pages
;
7777 pgdat
->totalreserve_pages
+= max
;
7779 reserve_pages
+= max
;
7782 totalreserve_pages
= reserve_pages
;
7786 * setup_per_zone_lowmem_reserve - called whenever
7787 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
7788 * has a correct pages reserved value, so an adequate number of
7789 * pages are left in the zone after a successful __alloc_pages().
7791 static void setup_per_zone_lowmem_reserve(void)
7793 struct pglist_data
*pgdat
;
7794 enum zone_type j
, idx
;
7796 for_each_online_pgdat(pgdat
) {
7797 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
7798 struct zone
*zone
= pgdat
->node_zones
+ j
;
7799 unsigned long managed_pages
= zone_managed_pages(zone
);
7801 zone
->lowmem_reserve
[j
] = 0;
7805 struct zone
*lower_zone
;
7808 lower_zone
= pgdat
->node_zones
+ idx
;
7810 if (!sysctl_lowmem_reserve_ratio
[idx
] ||
7811 !zone_managed_pages(lower_zone
)) {
7812 lower_zone
->lowmem_reserve
[j
] = 0;
7815 lower_zone
->lowmem_reserve
[j
] =
7816 managed_pages
/ sysctl_lowmem_reserve_ratio
[idx
];
7818 managed_pages
+= zone_managed_pages(lower_zone
);
7823 /* update totalreserve_pages */
7824 calculate_totalreserve_pages();
7827 static void __setup_per_zone_wmarks(void)
7829 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
7830 unsigned long lowmem_pages
= 0;
7832 unsigned long flags
;
7834 /* Calculate total number of !ZONE_HIGHMEM pages */
7835 for_each_zone(zone
) {
7836 if (!is_highmem(zone
))
7837 lowmem_pages
+= zone_managed_pages(zone
);
7840 for_each_zone(zone
) {
7843 spin_lock_irqsave(&zone
->lock
, flags
);
7844 tmp
= (u64
)pages_min
* zone_managed_pages(zone
);
7845 do_div(tmp
, lowmem_pages
);
7846 if (is_highmem(zone
)) {
7848 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
7849 * need highmem pages, so cap pages_min to a small
7852 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
7853 * deltas control async page reclaim, and so should
7854 * not be capped for highmem.
7856 unsigned long min_pages
;
7858 min_pages
= zone_managed_pages(zone
) / 1024;
7859 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
7860 zone
->_watermark
[WMARK_MIN
] = min_pages
;
7863 * If it's a lowmem zone, reserve a number of pages
7864 * proportionate to the zone's size.
7866 zone
->_watermark
[WMARK_MIN
] = tmp
;
7870 * Set the kswapd watermarks distance according to the
7871 * scale factor in proportion to available memory, but
7872 * ensure a minimum size on small systems.
7874 tmp
= max_t(u64
, tmp
>> 2,
7875 mult_frac(zone_managed_pages(zone
),
7876 watermark_scale_factor
, 10000));
7878 zone
->watermark_boost
= 0;
7879 zone
->_watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + tmp
;
7880 zone
->_watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + tmp
* 2;
7882 spin_unlock_irqrestore(&zone
->lock
, flags
);
7885 /* update totalreserve_pages */
7886 calculate_totalreserve_pages();
7890 * setup_per_zone_wmarks - called when min_free_kbytes changes
7891 * or when memory is hot-{added|removed}
7893 * Ensures that the watermark[min,low,high] values for each zone are set
7894 * correctly with respect to min_free_kbytes.
7896 void setup_per_zone_wmarks(void)
7898 static DEFINE_SPINLOCK(lock
);
7901 __setup_per_zone_wmarks();
7906 * Initialise min_free_kbytes.
7908 * For small machines we want it small (128k min). For large machines
7909 * we want it large (256MB max). But it is not linear, because network
7910 * bandwidth does not increase linearly with machine size. We use
7912 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
7913 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
7929 int __meminit
init_per_zone_wmark_min(void)
7931 unsigned long lowmem_kbytes
;
7932 int new_min_free_kbytes
;
7934 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
7935 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
7937 if (new_min_free_kbytes
> user_min_free_kbytes
) {
7938 min_free_kbytes
= new_min_free_kbytes
;
7939 if (min_free_kbytes
< 128)
7940 min_free_kbytes
= 128;
7941 if (min_free_kbytes
> 262144)
7942 min_free_kbytes
= 262144;
7944 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
7945 new_min_free_kbytes
, user_min_free_kbytes
);
7947 setup_per_zone_wmarks();
7948 refresh_zone_stat_thresholds();
7949 setup_per_zone_lowmem_reserve();
7952 setup_min_unmapped_ratio();
7953 setup_min_slab_ratio();
7956 khugepaged_min_free_kbytes_update();
7960 postcore_initcall(init_per_zone_wmark_min
)
7963 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
7964 * that we can call two helper functions whenever min_free_kbytes
7967 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
7968 void *buffer
, size_t *length
, loff_t
*ppos
)
7972 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7977 user_min_free_kbytes
= min_free_kbytes
;
7978 setup_per_zone_wmarks();
7983 int watermark_scale_factor_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
);
7993 setup_per_zone_wmarks();
7999 static void setup_min_unmapped_ratio(void)
8004 for_each_online_pgdat(pgdat
)
8005 pgdat
->min_unmapped_pages
= 0;
8008 zone
->zone_pgdat
->min_unmapped_pages
+= (zone_managed_pages(zone
) *
8009 sysctl_min_unmapped_ratio
) / 100;
8013 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
8014 void *buffer
, size_t *length
, loff_t
*ppos
)
8018 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
8022 setup_min_unmapped_ratio();
8027 static void setup_min_slab_ratio(void)
8032 for_each_online_pgdat(pgdat
)
8033 pgdat
->min_slab_pages
= 0;
8036 zone
->zone_pgdat
->min_slab_pages
+= (zone_managed_pages(zone
) *
8037 sysctl_min_slab_ratio
) / 100;
8040 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
8041 void *buffer
, size_t *length
, loff_t
*ppos
)
8045 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
8049 setup_min_slab_ratio();
8056 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
8057 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
8058 * whenever sysctl_lowmem_reserve_ratio changes.
8060 * The reserve ratio obviously has absolutely no relation with the
8061 * minimum watermarks. The lowmem reserve ratio can only make sense
8062 * if in function of the boot time zone sizes.
8064 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
8065 void *buffer
, size_t *length
, loff_t
*ppos
)
8069 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
8071 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
8072 if (sysctl_lowmem_reserve_ratio
[i
] < 1)
8073 sysctl_lowmem_reserve_ratio
[i
] = 0;
8076 setup_per_zone_lowmem_reserve();
8080 static void __zone_pcp_update(struct zone
*zone
)
8084 for_each_possible_cpu(cpu
)
8085 pageset_set_high_and_batch(zone
,
8086 per_cpu_ptr(zone
->pageset
, cpu
));
8090 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
8091 * cpu. It is the fraction of total pages in each zone that a hot per cpu
8092 * pagelist can have before it gets flushed back to buddy allocator.
8094 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
8095 void *buffer
, size_t *length
, loff_t
*ppos
)
8098 int old_percpu_pagelist_fraction
;
8101 mutex_lock(&pcp_batch_high_lock
);
8102 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
8104 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
8105 if (!write
|| ret
< 0)
8108 /* Sanity checking to avoid pcp imbalance */
8109 if (percpu_pagelist_fraction
&&
8110 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
8111 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
8117 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
8120 for_each_populated_zone(zone
)
8121 __zone_pcp_update(zone
);
8123 mutex_unlock(&pcp_batch_high_lock
);
8127 #ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES
8129 * Returns the number of pages that arch has reserved but
8130 * is not known to alloc_large_system_hash().
8132 static unsigned long __init
arch_reserved_kernel_pages(void)
8139 * Adaptive scale is meant to reduce sizes of hash tables on large memory
8140 * machines. As memory size is increased the scale is also increased but at
8141 * slower pace. Starting from ADAPT_SCALE_BASE (64G), every time memory
8142 * quadruples the scale is increased by one, which means the size of hash table
8143 * only doubles, instead of quadrupling as well.
8144 * Because 32-bit systems cannot have large physical memory, where this scaling
8145 * makes sense, it is disabled on such platforms.
8147 #if __BITS_PER_LONG > 32
8148 #define ADAPT_SCALE_BASE (64ul << 30)
8149 #define ADAPT_SCALE_SHIFT 2
8150 #define ADAPT_SCALE_NPAGES (ADAPT_SCALE_BASE >> PAGE_SHIFT)
8154 * allocate a large system hash table from bootmem
8155 * - it is assumed that the hash table must contain an exact power-of-2
8156 * quantity of entries
8157 * - limit is the number of hash buckets, not the total allocation size
8159 void *__init
alloc_large_system_hash(const char *tablename
,
8160 unsigned long bucketsize
,
8161 unsigned long numentries
,
8164 unsigned int *_hash_shift
,
8165 unsigned int *_hash_mask
,
8166 unsigned long low_limit
,
8167 unsigned long high_limit
)
8169 unsigned long long max
= high_limit
;
8170 unsigned long log2qty
, size
;
8175 /* allow the kernel cmdline to have a say */
8177 /* round applicable memory size up to nearest megabyte */
8178 numentries
= nr_kernel_pages
;
8179 numentries
-= arch_reserved_kernel_pages();
8181 /* It isn't necessary when PAGE_SIZE >= 1MB */
8182 if (PAGE_SHIFT
< 20)
8183 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
8185 #if __BITS_PER_LONG > 32
8187 unsigned long adapt
;
8189 for (adapt
= ADAPT_SCALE_NPAGES
; adapt
< numentries
;
8190 adapt
<<= ADAPT_SCALE_SHIFT
)
8195 /* limit to 1 bucket per 2^scale bytes of low memory */
8196 if (scale
> PAGE_SHIFT
)
8197 numentries
>>= (scale
- PAGE_SHIFT
);
8199 numentries
<<= (PAGE_SHIFT
- scale
);
8201 /* Make sure we've got at least a 0-order allocation.. */
8202 if (unlikely(flags
& HASH_SMALL
)) {
8203 /* Makes no sense without HASH_EARLY */
8204 WARN_ON(!(flags
& HASH_EARLY
));
8205 if (!(numentries
>> *_hash_shift
)) {
8206 numentries
= 1UL << *_hash_shift
;
8207 BUG_ON(!numentries
);
8209 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
8210 numentries
= PAGE_SIZE
/ bucketsize
;
8212 numentries
= roundup_pow_of_two(numentries
);
8214 /* limit allocation size to 1/16 total memory by default */
8216 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
8217 do_div(max
, bucketsize
);
8219 max
= min(max
, 0x80000000ULL
);
8221 if (numentries
< low_limit
)
8222 numentries
= low_limit
;
8223 if (numentries
> max
)
8226 log2qty
= ilog2(numentries
);
8228 gfp_flags
= (flags
& HASH_ZERO
) ? GFP_ATOMIC
| __GFP_ZERO
: GFP_ATOMIC
;
8231 size
= bucketsize
<< log2qty
;
8232 if (flags
& HASH_EARLY
) {
8233 if (flags
& HASH_ZERO
)
8234 table
= memblock_alloc(size
, SMP_CACHE_BYTES
);
8236 table
= memblock_alloc_raw(size
,
8238 } else if (get_order(size
) >= MAX_ORDER
|| hashdist
) {
8239 table
= __vmalloc(size
, gfp_flags
);
8243 * If bucketsize is not a power-of-two, we may free
8244 * some pages at the end of hash table which
8245 * alloc_pages_exact() automatically does
8247 table
= alloc_pages_exact(size
, gfp_flags
);
8248 kmemleak_alloc(table
, size
, 1, gfp_flags
);
8250 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
8253 panic("Failed to allocate %s hash table\n", tablename
);
8255 pr_info("%s hash table entries: %ld (order: %d, %lu bytes, %s)\n",
8256 tablename
, 1UL << log2qty
, ilog2(size
) - PAGE_SHIFT
, size
,
8257 virt
? "vmalloc" : "linear");
8260 *_hash_shift
= log2qty
;
8262 *_hash_mask
= (1 << log2qty
) - 1;
8268 * This function checks whether pageblock includes unmovable pages or not.
8270 * PageLRU check without isolation or lru_lock could race so that
8271 * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable
8272 * check without lock_page also may miss some movable non-lru pages at
8273 * race condition. So you can't expect this function should be exact.
8275 * Returns a page without holding a reference. If the caller wants to
8276 * dereference that page (e.g., dumping), it has to make sure that it
8277 * cannot get removed (e.g., via memory unplug) concurrently.
8280 struct page
*has_unmovable_pages(struct zone
*zone
, struct page
*page
,
8281 int migratetype
, int flags
)
8283 unsigned long iter
= 0;
8284 unsigned long pfn
= page_to_pfn(page
);
8285 unsigned long offset
= pfn
% pageblock_nr_pages
;
8287 if (is_migrate_cma_page(page
)) {
8289 * CMA allocations (alloc_contig_range) really need to mark
8290 * isolate CMA pageblocks even when they are not movable in fact
8291 * so consider them movable here.
8293 if (is_migrate_cma(migratetype
))
8299 for (; iter
< pageblock_nr_pages
- offset
; iter
++) {
8300 if (!pfn_valid_within(pfn
+ iter
))
8303 page
= pfn_to_page(pfn
+ iter
);
8306 * Both, bootmem allocations and memory holes are marked
8307 * PG_reserved and are unmovable. We can even have unmovable
8308 * allocations inside ZONE_MOVABLE, for example when
8309 * specifying "movablecore".
8311 if (PageReserved(page
))
8315 * If the zone is movable and we have ruled out all reserved
8316 * pages then it should be reasonably safe to assume the rest
8319 if (zone_idx(zone
) == ZONE_MOVABLE
)
8323 * Hugepages are not in LRU lists, but they're movable.
8324 * THPs are on the LRU, but need to be counted as #small pages.
8325 * We need not scan over tail pages because we don't
8326 * handle each tail page individually in migration.
8328 if (PageHuge(page
) || PageTransCompound(page
)) {
8329 struct page
*head
= compound_head(page
);
8330 unsigned int skip_pages
;
8332 if (PageHuge(page
)) {
8333 if (!hugepage_migration_supported(page_hstate(head
)))
8335 } else if (!PageLRU(head
) && !__PageMovable(head
)) {
8339 skip_pages
= compound_nr(head
) - (page
- head
);
8340 iter
+= skip_pages
- 1;
8345 * We can't use page_count without pin a page
8346 * because another CPU can free compound page.
8347 * This check already skips compound tails of THP
8348 * because their page->_refcount is zero at all time.
8350 if (!page_ref_count(page
)) {
8351 if (PageBuddy(page
))
8352 iter
+= (1 << buddy_order(page
)) - 1;
8357 * The HWPoisoned page may be not in buddy system, and
8358 * page_count() is not 0.
8360 if ((flags
& MEMORY_OFFLINE
) && PageHWPoison(page
))
8364 * We treat all PageOffline() pages as movable when offlining
8365 * to give drivers a chance to decrement their reference count
8366 * in MEM_GOING_OFFLINE in order to indicate that these pages
8367 * can be offlined as there are no direct references anymore.
8368 * For actually unmovable PageOffline() where the driver does
8369 * not support this, we will fail later when trying to actually
8370 * move these pages that still have a reference count > 0.
8371 * (false negatives in this function only)
8373 if ((flags
& MEMORY_OFFLINE
) && PageOffline(page
))
8376 if (__PageMovable(page
) || PageLRU(page
))
8380 * If there are RECLAIMABLE pages, we need to check
8381 * it. But now, memory offline itself doesn't call
8382 * shrink_node_slabs() and it still to be fixed.
8389 #ifdef CONFIG_CONTIG_ALLOC
8390 static unsigned long pfn_max_align_down(unsigned long pfn
)
8392 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
8393 pageblock_nr_pages
) - 1);
8396 static unsigned long pfn_max_align_up(unsigned long pfn
)
8398 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
8399 pageblock_nr_pages
));
8402 /* [start, end) must belong to a single zone. */
8403 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
8404 unsigned long start
, unsigned long end
)
8406 /* This function is based on compact_zone() from compaction.c. */
8407 unsigned int nr_reclaimed
;
8408 unsigned long pfn
= start
;
8409 unsigned int tries
= 0;
8411 struct migration_target_control mtc
= {
8412 .nid
= zone_to_nid(cc
->zone
),
8413 .gfp_mask
= GFP_USER
| __GFP_MOVABLE
| __GFP_RETRY_MAYFAIL
,
8418 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
8419 if (fatal_signal_pending(current
)) {
8424 if (list_empty(&cc
->migratepages
)) {
8425 cc
->nr_migratepages
= 0;
8426 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
8432 } else if (++tries
== 5) {
8433 ret
= ret
< 0 ? ret
: -EBUSY
;
8437 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
8439 cc
->nr_migratepages
-= nr_reclaimed
;
8441 ret
= migrate_pages(&cc
->migratepages
, alloc_migration_target
,
8442 NULL
, (unsigned long)&mtc
, cc
->mode
, MR_CONTIG_RANGE
);
8445 putback_movable_pages(&cc
->migratepages
);
8452 * alloc_contig_range() -- tries to allocate given range of pages
8453 * @start: start PFN to allocate
8454 * @end: one-past-the-last PFN to allocate
8455 * @migratetype: migratetype of the underlaying pageblocks (either
8456 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
8457 * in range must have the same migratetype and it must
8458 * be either of the two.
8459 * @gfp_mask: GFP mask to use during compaction
8461 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
8462 * aligned. The PFN range must belong to a single zone.
8464 * The first thing this routine does is attempt to MIGRATE_ISOLATE all
8465 * pageblocks in the range. Once isolated, the pageblocks should not
8466 * be modified by others.
8468 * Return: zero on success or negative error code. On success all
8469 * pages which PFN is in [start, end) are allocated for the caller and
8470 * need to be freed with free_contig_range().
8472 int alloc_contig_range(unsigned long start
, unsigned long end
,
8473 unsigned migratetype
, gfp_t gfp_mask
)
8475 unsigned long outer_start
, outer_end
;
8479 struct compact_control cc
= {
8480 .nr_migratepages
= 0,
8482 .zone
= page_zone(pfn_to_page(start
)),
8483 .mode
= MIGRATE_SYNC
,
8484 .ignore_skip_hint
= true,
8485 .no_set_skip_hint
= true,
8486 .gfp_mask
= current_gfp_context(gfp_mask
),
8487 .alloc_contig
= true,
8489 INIT_LIST_HEAD(&cc
.migratepages
);
8492 * What we do here is we mark all pageblocks in range as
8493 * MIGRATE_ISOLATE. Because pageblock and max order pages may
8494 * have different sizes, and due to the way page allocator
8495 * work, we align the range to biggest of the two pages so
8496 * that page allocator won't try to merge buddies from
8497 * different pageblocks and change MIGRATE_ISOLATE to some
8498 * other migration type.
8500 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
8501 * migrate the pages from an unaligned range (ie. pages that
8502 * we are interested in). This will put all the pages in
8503 * range back to page allocator as MIGRATE_ISOLATE.
8505 * When this is done, we take the pages in range from page
8506 * allocator removing them from the buddy system. This way
8507 * page allocator will never consider using them.
8509 * This lets us mark the pageblocks back as
8510 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
8511 * aligned range but not in the unaligned, original range are
8512 * put back to page allocator so that buddy can use them.
8515 ret
= start_isolate_page_range(pfn_max_align_down(start
),
8516 pfn_max_align_up(end
), migratetype
, 0);
8521 * In case of -EBUSY, we'd like to know which page causes problem.
8522 * So, just fall through. test_pages_isolated() has a tracepoint
8523 * which will report the busy page.
8525 * It is possible that busy pages could become available before
8526 * the call to test_pages_isolated, and the range will actually be
8527 * allocated. So, if we fall through be sure to clear ret so that
8528 * -EBUSY is not accidentally used or returned to caller.
8530 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
8531 if (ret
&& ret
!= -EBUSY
)
8536 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
8537 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
8538 * more, all pages in [start, end) are free in page allocator.
8539 * What we are going to do is to allocate all pages from
8540 * [start, end) (that is remove them from page allocator).
8542 * The only problem is that pages at the beginning and at the
8543 * end of interesting range may be not aligned with pages that
8544 * page allocator holds, ie. they can be part of higher order
8545 * pages. Because of this, we reserve the bigger range and
8546 * once this is done free the pages we are not interested in.
8548 * We don't have to hold zone->lock here because the pages are
8549 * isolated thus they won't get removed from buddy.
8552 lru_add_drain_all();
8555 outer_start
= start
;
8556 while (!PageBuddy(pfn_to_page(outer_start
))) {
8557 if (++order
>= MAX_ORDER
) {
8558 outer_start
= start
;
8561 outer_start
&= ~0UL << order
;
8564 if (outer_start
!= start
) {
8565 order
= buddy_order(pfn_to_page(outer_start
));
8568 * outer_start page could be small order buddy page and
8569 * it doesn't include start page. Adjust outer_start
8570 * in this case to report failed page properly
8571 * on tracepoint in test_pages_isolated()
8573 if (outer_start
+ (1UL << order
) <= start
)
8574 outer_start
= start
;
8577 /* Make sure the range is really isolated. */
8578 if (test_pages_isolated(outer_start
, end
, 0)) {
8579 pr_info_ratelimited("%s: [%lx, %lx) PFNs busy\n",
8580 __func__
, outer_start
, end
);
8585 /* Grab isolated pages from freelists. */
8586 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
8592 /* Free head and tail (if any) */
8593 if (start
!= outer_start
)
8594 free_contig_range(outer_start
, start
- outer_start
);
8595 if (end
!= outer_end
)
8596 free_contig_range(end
, outer_end
- end
);
8599 undo_isolate_page_range(pfn_max_align_down(start
),
8600 pfn_max_align_up(end
), migratetype
);
8603 EXPORT_SYMBOL(alloc_contig_range
);
8605 static int __alloc_contig_pages(unsigned long start_pfn
,
8606 unsigned long nr_pages
, gfp_t gfp_mask
)
8608 unsigned long end_pfn
= start_pfn
+ nr_pages
;
8610 return alloc_contig_range(start_pfn
, end_pfn
, MIGRATE_MOVABLE
,
8614 static bool pfn_range_valid_contig(struct zone
*z
, unsigned long start_pfn
,
8615 unsigned long nr_pages
)
8617 unsigned long i
, end_pfn
= start_pfn
+ nr_pages
;
8620 for (i
= start_pfn
; i
< end_pfn
; i
++) {
8621 page
= pfn_to_online_page(i
);
8625 if (page_zone(page
) != z
)
8628 if (PageReserved(page
))
8631 if (page_count(page
) > 0)
8640 static bool zone_spans_last_pfn(const struct zone
*zone
,
8641 unsigned long start_pfn
, unsigned long nr_pages
)
8643 unsigned long last_pfn
= start_pfn
+ nr_pages
- 1;
8645 return zone_spans_pfn(zone
, last_pfn
);
8649 * alloc_contig_pages() -- tries to find and allocate contiguous range of pages
8650 * @nr_pages: Number of contiguous pages to allocate
8651 * @gfp_mask: GFP mask to limit search and used during compaction
8653 * @nodemask: Mask for other possible nodes
8655 * This routine is a wrapper around alloc_contig_range(). It scans over zones
8656 * on an applicable zonelist to find a contiguous pfn range which can then be
8657 * tried for allocation with alloc_contig_range(). This routine is intended
8658 * for allocation requests which can not be fulfilled with the buddy allocator.
8660 * The allocated memory is always aligned to a page boundary. If nr_pages is a
8661 * power of two then the alignment is guaranteed to be to the given nr_pages
8662 * (e.g. 1GB request would be aligned to 1GB).
8664 * Allocated pages can be freed with free_contig_range() or by manually calling
8665 * __free_page() on each allocated page.
8667 * Return: pointer to contiguous pages on success, or NULL if not successful.
8669 struct page
*alloc_contig_pages(unsigned long nr_pages
, gfp_t gfp_mask
,
8670 int nid
, nodemask_t
*nodemask
)
8672 unsigned long ret
, pfn
, flags
;
8673 struct zonelist
*zonelist
;
8677 zonelist
= node_zonelist(nid
, gfp_mask
);
8678 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
8679 gfp_zone(gfp_mask
), nodemask
) {
8680 spin_lock_irqsave(&zone
->lock
, flags
);
8682 pfn
= ALIGN(zone
->zone_start_pfn
, nr_pages
);
8683 while (zone_spans_last_pfn(zone
, pfn
, nr_pages
)) {
8684 if (pfn_range_valid_contig(zone
, pfn
, nr_pages
)) {
8686 * We release the zone lock here because
8687 * alloc_contig_range() will also lock the zone
8688 * at some point. If there's an allocation
8689 * spinning on this lock, it may win the race
8690 * and cause alloc_contig_range() to fail...
8692 spin_unlock_irqrestore(&zone
->lock
, flags
);
8693 ret
= __alloc_contig_pages(pfn
, nr_pages
,
8696 return pfn_to_page(pfn
);
8697 spin_lock_irqsave(&zone
->lock
, flags
);
8701 spin_unlock_irqrestore(&zone
->lock
, flags
);
8705 #endif /* CONFIG_CONTIG_ALLOC */
8707 void free_contig_range(unsigned long pfn
, unsigned int nr_pages
)
8709 unsigned int count
= 0;
8711 for (; nr_pages
--; pfn
++) {
8712 struct page
*page
= pfn_to_page(pfn
);
8714 count
+= page_count(page
) != 1;
8717 WARN(count
!= 0, "%d pages are still in use!\n", count
);
8719 EXPORT_SYMBOL(free_contig_range
);
8722 * The zone indicated has a new number of managed_pages; batch sizes and percpu
8723 * page high values need to be recalulated.
8725 void __meminit
zone_pcp_update(struct zone
*zone
)
8727 mutex_lock(&pcp_batch_high_lock
);
8728 __zone_pcp_update(zone
);
8729 mutex_unlock(&pcp_batch_high_lock
);
8732 void zone_pcp_reset(struct zone
*zone
)
8734 unsigned long flags
;
8736 struct per_cpu_pageset
*pset
;
8738 /* avoid races with drain_pages() */
8739 local_irq_save(flags
);
8740 if (zone
->pageset
!= &boot_pageset
) {
8741 for_each_online_cpu(cpu
) {
8742 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
8743 drain_zonestat(zone
, pset
);
8745 free_percpu(zone
->pageset
);
8746 zone
->pageset
= &boot_pageset
;
8748 local_irq_restore(flags
);
8751 #ifdef CONFIG_MEMORY_HOTREMOVE
8753 * All pages in the range must be in a single zone, must not contain holes,
8754 * must span full sections, and must be isolated before calling this function.
8756 void __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
8758 unsigned long pfn
= start_pfn
;
8762 unsigned long flags
;
8764 offline_mem_sections(pfn
, end_pfn
);
8765 zone
= page_zone(pfn_to_page(pfn
));
8766 spin_lock_irqsave(&zone
->lock
, flags
);
8767 while (pfn
< end_pfn
) {
8768 page
= pfn_to_page(pfn
);
8770 * The HWPoisoned page may be not in buddy system, and
8771 * page_count() is not 0.
8773 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
8778 * At this point all remaining PageOffline() pages have a
8779 * reference count of 0 and can simply be skipped.
8781 if (PageOffline(page
)) {
8782 BUG_ON(page_count(page
));
8783 BUG_ON(PageBuddy(page
));
8788 BUG_ON(page_count(page
));
8789 BUG_ON(!PageBuddy(page
));
8790 order
= buddy_order(page
);
8791 del_page_from_free_list(page
, zone
, order
);
8792 pfn
+= (1 << order
);
8794 spin_unlock_irqrestore(&zone
->lock
, flags
);
8798 bool is_free_buddy_page(struct page
*page
)
8800 struct zone
*zone
= page_zone(page
);
8801 unsigned long pfn
= page_to_pfn(page
);
8802 unsigned long flags
;
8805 spin_lock_irqsave(&zone
->lock
, flags
);
8806 for (order
= 0; order
< MAX_ORDER
; order
++) {
8807 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
8809 if (PageBuddy(page_head
) && buddy_order(page_head
) >= order
)
8812 spin_unlock_irqrestore(&zone
->lock
, flags
);
8814 return order
< MAX_ORDER
;
8817 #ifdef CONFIG_MEMORY_FAILURE
8819 * Break down a higher-order page in sub-pages, and keep our target out of
8822 static void break_down_buddy_pages(struct zone
*zone
, struct page
*page
,
8823 struct page
*target
, int low
, int high
,
8826 unsigned long size
= 1 << high
;
8827 struct page
*current_buddy
, *next_page
;
8829 while (high
> low
) {
8833 if (target
>= &page
[size
]) {
8834 next_page
= page
+ size
;
8835 current_buddy
= page
;
8838 current_buddy
= page
+ size
;
8841 if (set_page_guard(zone
, current_buddy
, high
, migratetype
))
8844 if (current_buddy
!= target
) {
8845 add_to_free_list(current_buddy
, zone
, high
, migratetype
);
8846 set_buddy_order(current_buddy
, high
);
8853 * Take a page that will be marked as poisoned off the buddy allocator.
8855 bool take_page_off_buddy(struct page
*page
)
8857 struct zone
*zone
= page_zone(page
);
8858 unsigned long pfn
= page_to_pfn(page
);
8859 unsigned long flags
;
8863 spin_lock_irqsave(&zone
->lock
, flags
);
8864 for (order
= 0; order
< MAX_ORDER
; order
++) {
8865 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
8866 int page_order
= buddy_order(page_head
);
8868 if (PageBuddy(page_head
) && page_order
>= order
) {
8869 unsigned long pfn_head
= page_to_pfn(page_head
);
8870 int migratetype
= get_pfnblock_migratetype(page_head
,
8873 del_page_from_free_list(page_head
, zone
, page_order
);
8874 break_down_buddy_pages(zone
, page_head
, page
, 0,
8875 page_order
, migratetype
);
8879 if (page_count(page_head
) > 0)
8882 spin_unlock_irqrestore(&zone
->lock
, flags
);