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/page_ext.h>
54 #include <linux/debugobjects.h>
55 #include <linux/kmemleak.h>
56 #include <linux/compaction.h>
57 #include <trace/events/kmem.h>
58 #include <trace/events/oom.h>
59 #include <linux/prefetch.h>
60 #include <linux/mm_inline.h>
61 #include <linux/migrate.h>
62 #include <linux/hugetlb.h>
63 #include <linux/sched/rt.h>
64 #include <linux/sched/mm.h>
65 #include <linux/page_owner.h>
66 #include <linux/kthread.h>
67 #include <linux/memcontrol.h>
68 #include <linux/ftrace.h>
69 #include <linux/lockdep.h>
70 #include <linux/nmi.h>
71 #include <linux/psi.h>
73 #include <asm/sections.h>
74 #include <asm/tlbflush.h>
75 #include <asm/div64.h>
79 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
80 static DEFINE_MUTEX(pcp_batch_high_lock
);
81 #define MIN_PERCPU_PAGELIST_FRACTION (8)
83 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
84 DEFINE_PER_CPU(int, numa_node
);
85 EXPORT_PER_CPU_SYMBOL(numa_node
);
88 DEFINE_STATIC_KEY_TRUE(vm_numa_stat_key
);
90 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
92 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
93 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
94 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
95 * defined in <linux/topology.h>.
97 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
98 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
99 int _node_numa_mem_
[MAX_NUMNODES
];
102 /* work_structs for global per-cpu drains */
105 struct work_struct work
;
107 DEFINE_MUTEX(pcpu_drain_mutex
);
108 DEFINE_PER_CPU(struct pcpu_drain
, pcpu_drain
);
110 #ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
111 volatile unsigned long latent_entropy __latent_entropy
;
112 EXPORT_SYMBOL(latent_entropy
);
116 * Array of node states.
118 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
119 [N_POSSIBLE
] = NODE_MASK_ALL
,
120 [N_ONLINE
] = { { [0] = 1UL } },
122 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
123 #ifdef CONFIG_HIGHMEM
124 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
126 [N_MEMORY
] = { { [0] = 1UL } },
127 [N_CPU
] = { { [0] = 1UL } },
130 EXPORT_SYMBOL(node_states
);
132 atomic_long_t _totalram_pages __read_mostly
;
133 EXPORT_SYMBOL(_totalram_pages
);
134 unsigned long totalreserve_pages __read_mostly
;
135 unsigned long totalcma_pages __read_mostly
;
137 int percpu_pagelist_fraction
;
138 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
141 * A cached value of the page's pageblock's migratetype, used when the page is
142 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
143 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
144 * Also the migratetype set in the page does not necessarily match the pcplist
145 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
146 * other index - this ensures that it will be put on the correct CMA freelist.
148 static inline int get_pcppage_migratetype(struct page
*page
)
153 static inline void set_pcppage_migratetype(struct page
*page
, int migratetype
)
155 page
->index
= migratetype
;
158 #ifdef CONFIG_PM_SLEEP
160 * The following functions are used by the suspend/hibernate code to temporarily
161 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
162 * while devices are suspended. To avoid races with the suspend/hibernate code,
163 * they should always be called with system_transition_mutex held
164 * (gfp_allowed_mask also should only be modified with system_transition_mutex
165 * held, unless the suspend/hibernate code is guaranteed not to run in parallel
166 * with that modification).
169 static gfp_t saved_gfp_mask
;
171 void pm_restore_gfp_mask(void)
173 WARN_ON(!mutex_is_locked(&system_transition_mutex
));
174 if (saved_gfp_mask
) {
175 gfp_allowed_mask
= saved_gfp_mask
;
180 void pm_restrict_gfp_mask(void)
182 WARN_ON(!mutex_is_locked(&system_transition_mutex
));
183 WARN_ON(saved_gfp_mask
);
184 saved_gfp_mask
= gfp_allowed_mask
;
185 gfp_allowed_mask
&= ~(__GFP_IO
| __GFP_FS
);
188 bool pm_suspended_storage(void)
190 if ((gfp_allowed_mask
& (__GFP_IO
| __GFP_FS
)) == (__GFP_IO
| __GFP_FS
))
194 #endif /* CONFIG_PM_SLEEP */
196 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
197 unsigned int pageblock_order __read_mostly
;
200 static void __free_pages_ok(struct page
*page
, unsigned int order
);
203 * results with 256, 32 in the lowmem_reserve sysctl:
204 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
205 * 1G machine -> (16M dma, 784M normal, 224M high)
206 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
207 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
208 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
210 * TBD: should special case ZONE_DMA32 machines here - in those we normally
211 * don't need any ZONE_NORMAL reservation
213 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
] = {
214 #ifdef CONFIG_ZONE_DMA
217 #ifdef CONFIG_ZONE_DMA32
221 #ifdef CONFIG_HIGHMEM
227 EXPORT_SYMBOL(totalram_pages
);
229 static char * const zone_names
[MAX_NR_ZONES
] = {
230 #ifdef CONFIG_ZONE_DMA
233 #ifdef CONFIG_ZONE_DMA32
237 #ifdef CONFIG_HIGHMEM
241 #ifdef CONFIG_ZONE_DEVICE
246 const char * const migratetype_names
[MIGRATE_TYPES
] = {
254 #ifdef CONFIG_MEMORY_ISOLATION
259 compound_page_dtor
* const compound_page_dtors
[] = {
262 #ifdef CONFIG_HUGETLB_PAGE
265 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
270 int min_free_kbytes
= 1024;
271 int user_min_free_kbytes
= -1;
272 #ifdef CONFIG_DISCONTIGMEM
274 * DiscontigMem defines memory ranges as separate pg_data_t even if the ranges
275 * are not on separate NUMA nodes. Functionally this works but with
276 * watermark_boost_factor, it can reclaim prematurely as the ranges can be
277 * quite small. By default, do not boost watermarks on discontigmem as in
278 * many cases very high-order allocations like THP are likely to be
279 * unsupported and the premature reclaim offsets the advantage of long-term
280 * fragmentation avoidance.
282 int watermark_boost_factor __read_mostly
;
284 int watermark_boost_factor __read_mostly
= 15000;
286 int watermark_scale_factor
= 10;
288 static unsigned long nr_kernel_pages __initdata
;
289 static unsigned long nr_all_pages __initdata
;
290 static unsigned long dma_reserve __initdata
;
292 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
293 static unsigned long arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
] __initdata
;
294 static unsigned long arch_zone_highest_possible_pfn
[MAX_NR_ZONES
] __initdata
;
295 static unsigned long required_kernelcore __initdata
;
296 static unsigned long required_kernelcore_percent __initdata
;
297 static unsigned long required_movablecore __initdata
;
298 static unsigned long required_movablecore_percent __initdata
;
299 static unsigned long zone_movable_pfn
[MAX_NUMNODES
] __initdata
;
300 static bool mirrored_kernelcore __meminitdata
;
302 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
304 EXPORT_SYMBOL(movable_zone
);
305 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
308 unsigned int nr_node_ids __read_mostly
= MAX_NUMNODES
;
309 unsigned int nr_online_nodes __read_mostly
= 1;
310 EXPORT_SYMBOL(nr_node_ids
);
311 EXPORT_SYMBOL(nr_online_nodes
);
314 int page_group_by_mobility_disabled __read_mostly
;
316 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
318 * During boot we initialize deferred pages on-demand, as needed, but once
319 * page_alloc_init_late() has finished, the deferred pages are all initialized,
320 * and we can permanently disable that path.
322 static DEFINE_STATIC_KEY_TRUE(deferred_pages
);
325 * Calling kasan_free_pages() only after deferred memory initialization
326 * has completed. Poisoning pages during deferred memory init will greatly
327 * lengthen the process and cause problem in large memory systems as the
328 * deferred pages initialization is done with interrupt disabled.
330 * Assuming that there will be no reference to those newly initialized
331 * pages before they are ever allocated, this should have no effect on
332 * KASAN memory tracking as the poison will be properly inserted at page
333 * allocation time. The only corner case is when pages are allocated by
334 * on-demand allocation and then freed again before the deferred pages
335 * initialization is done, but this is not likely to happen.
337 static inline void kasan_free_nondeferred_pages(struct page
*page
, int order
)
339 if (!static_branch_unlikely(&deferred_pages
))
340 kasan_free_pages(page
, order
);
343 /* Returns true if the struct page for the pfn is uninitialised */
344 static inline bool __meminit
early_page_uninitialised(unsigned long pfn
)
346 int nid
= early_pfn_to_nid(pfn
);
348 if (node_online(nid
) && pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
355 * Returns true when the remaining initialisation should be deferred until
356 * later in the boot cycle when it can be parallelised.
358 static bool __meminit
359 defer_init(int nid
, unsigned long pfn
, unsigned long end_pfn
)
361 static unsigned long prev_end_pfn
, nr_initialised
;
364 * prev_end_pfn static that contains the end of previous zone
365 * No need to protect because called very early in boot before smp_init.
367 if (prev_end_pfn
!= end_pfn
) {
368 prev_end_pfn
= end_pfn
;
372 /* Always populate low zones for address-constrained allocations */
373 if (end_pfn
< pgdat_end_pfn(NODE_DATA(nid
)))
377 * We start only with one section of pages, more pages are added as
378 * needed until the rest of deferred pages are initialized.
381 if ((nr_initialised
> PAGES_PER_SECTION
) &&
382 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
383 NODE_DATA(nid
)->first_deferred_pfn
= pfn
;
389 #define kasan_free_nondeferred_pages(p, o) kasan_free_pages(p, o)
391 static inline bool early_page_uninitialised(unsigned long pfn
)
396 static inline bool defer_init(int nid
, unsigned long pfn
, unsigned long end_pfn
)
402 /* Return a pointer to the bitmap storing bits affecting a block of pages */
403 static inline unsigned long *get_pageblock_bitmap(struct page
*page
,
406 #ifdef CONFIG_SPARSEMEM
407 return __pfn_to_section(pfn
)->pageblock_flags
;
409 return page_zone(page
)->pageblock_flags
;
410 #endif /* CONFIG_SPARSEMEM */
413 static inline int pfn_to_bitidx(struct page
*page
, unsigned long pfn
)
415 #ifdef CONFIG_SPARSEMEM
416 pfn
&= (PAGES_PER_SECTION
-1);
417 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
419 pfn
= pfn
- round_down(page_zone(page
)->zone_start_pfn
, pageblock_nr_pages
);
420 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
421 #endif /* CONFIG_SPARSEMEM */
425 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
426 * @page: The page within the block of interest
427 * @pfn: The target page frame number
428 * @end_bitidx: The last bit of interest to retrieve
429 * @mask: mask of bits that the caller is interested in
431 * Return: pageblock_bits flags
433 static __always_inline
unsigned long __get_pfnblock_flags_mask(struct page
*page
,
435 unsigned long end_bitidx
,
438 unsigned long *bitmap
;
439 unsigned long bitidx
, word_bitidx
;
442 bitmap
= get_pageblock_bitmap(page
, pfn
);
443 bitidx
= pfn_to_bitidx(page
, pfn
);
444 word_bitidx
= bitidx
/ BITS_PER_LONG
;
445 bitidx
&= (BITS_PER_LONG
-1);
447 word
= bitmap
[word_bitidx
];
448 bitidx
+= end_bitidx
;
449 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
452 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
453 unsigned long end_bitidx
,
456 return __get_pfnblock_flags_mask(page
, pfn
, end_bitidx
, mask
);
459 static __always_inline
int get_pfnblock_migratetype(struct page
*page
, unsigned long pfn
)
461 return __get_pfnblock_flags_mask(page
, pfn
, PB_migrate_end
, MIGRATETYPE_MASK
);
465 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
466 * @page: The page within the block of interest
467 * @flags: The flags to set
468 * @pfn: The target page frame number
469 * @end_bitidx: The last bit of interest
470 * @mask: mask of bits that the caller is interested in
472 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
474 unsigned long end_bitidx
,
477 unsigned long *bitmap
;
478 unsigned long bitidx
, word_bitidx
;
479 unsigned long old_word
, word
;
481 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
482 BUILD_BUG_ON(MIGRATE_TYPES
> (1 << PB_migratetype_bits
));
484 bitmap
= get_pageblock_bitmap(page
, pfn
);
485 bitidx
= pfn_to_bitidx(page
, pfn
);
486 word_bitidx
= bitidx
/ BITS_PER_LONG
;
487 bitidx
&= (BITS_PER_LONG
-1);
489 VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page
), pfn
), page
);
491 bitidx
+= end_bitidx
;
492 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
493 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
495 word
= READ_ONCE(bitmap
[word_bitidx
]);
497 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
498 if (word
== old_word
)
504 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
506 if (unlikely(page_group_by_mobility_disabled
&&
507 migratetype
< MIGRATE_PCPTYPES
))
508 migratetype
= MIGRATE_UNMOVABLE
;
510 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
511 PB_migrate
, PB_migrate_end
);
514 #ifdef CONFIG_DEBUG_VM
515 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
519 unsigned long pfn
= page_to_pfn(page
);
520 unsigned long sp
, start_pfn
;
523 seq
= zone_span_seqbegin(zone
);
524 start_pfn
= zone
->zone_start_pfn
;
525 sp
= zone
->spanned_pages
;
526 if (!zone_spans_pfn(zone
, pfn
))
528 } while (zone_span_seqretry(zone
, seq
));
531 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
532 pfn
, zone_to_nid(zone
), zone
->name
,
533 start_pfn
, start_pfn
+ sp
);
538 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
540 if (!pfn_valid_within(page_to_pfn(page
)))
542 if (zone
!= page_zone(page
))
548 * Temporary debugging check for pages not lying within a given zone.
550 static int __maybe_unused
bad_range(struct zone
*zone
, struct page
*page
)
552 if (page_outside_zone_boundaries(zone
, page
))
554 if (!page_is_consistent(zone
, page
))
560 static inline int __maybe_unused
bad_range(struct zone
*zone
, struct page
*page
)
566 static void bad_page(struct page
*page
, const char *reason
,
567 unsigned long bad_flags
)
569 static unsigned long resume
;
570 static unsigned long nr_shown
;
571 static unsigned long nr_unshown
;
574 * Allow a burst of 60 reports, then keep quiet for that minute;
575 * or allow a steady drip of one report per second.
577 if (nr_shown
== 60) {
578 if (time_before(jiffies
, resume
)) {
584 "BUG: Bad page state: %lu messages suppressed\n",
591 resume
= jiffies
+ 60 * HZ
;
593 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
594 current
->comm
, page_to_pfn(page
));
595 __dump_page(page
, reason
);
596 bad_flags
&= page
->flags
;
598 pr_alert("bad because of flags: %#lx(%pGp)\n",
599 bad_flags
, &bad_flags
);
600 dump_page_owner(page
);
605 /* Leave bad fields for debug, except PageBuddy could make trouble */
606 page_mapcount_reset(page
); /* remove PageBuddy */
607 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
611 * Higher-order pages are called "compound pages". They are structured thusly:
613 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
615 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
616 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
618 * The first tail page's ->compound_dtor holds the offset in array of compound
619 * page destructors. See compound_page_dtors.
621 * The first tail page's ->compound_order holds the order of allocation.
622 * This usage means that zero-order pages may not be compound.
625 void free_compound_page(struct page
*page
)
627 __free_pages_ok(page
, compound_order(page
));
630 void prep_compound_page(struct page
*page
, unsigned int order
)
633 int nr_pages
= 1 << order
;
635 set_compound_page_dtor(page
, COMPOUND_PAGE_DTOR
);
636 set_compound_order(page
, order
);
638 for (i
= 1; i
< nr_pages
; i
++) {
639 struct page
*p
= page
+ i
;
640 set_page_count(p
, 0);
641 p
->mapping
= TAIL_MAPPING
;
642 set_compound_head(p
, page
);
644 atomic_set(compound_mapcount_ptr(page
), -1);
647 #ifdef CONFIG_DEBUG_PAGEALLOC
648 unsigned int _debug_guardpage_minorder
;
649 bool _debug_pagealloc_enabled __read_mostly
650 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT
);
651 EXPORT_SYMBOL(_debug_pagealloc_enabled
);
652 bool _debug_guardpage_enabled __read_mostly
;
654 static int __init
early_debug_pagealloc(char *buf
)
658 return kstrtobool(buf
, &_debug_pagealloc_enabled
);
660 early_param("debug_pagealloc", early_debug_pagealloc
);
662 static bool need_debug_guardpage(void)
664 /* If we don't use debug_pagealloc, we don't need guard page */
665 if (!debug_pagealloc_enabled())
668 if (!debug_guardpage_minorder())
674 static void init_debug_guardpage(void)
676 if (!debug_pagealloc_enabled())
679 if (!debug_guardpage_minorder())
682 _debug_guardpage_enabled
= true;
685 struct page_ext_operations debug_guardpage_ops
= {
686 .need
= need_debug_guardpage
,
687 .init
= init_debug_guardpage
,
690 static int __init
debug_guardpage_minorder_setup(char *buf
)
694 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
695 pr_err("Bad debug_guardpage_minorder value\n");
698 _debug_guardpage_minorder
= res
;
699 pr_info("Setting debug_guardpage_minorder to %lu\n", res
);
702 early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup
);
704 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
705 unsigned int order
, int migratetype
)
707 struct page_ext
*page_ext
;
709 if (!debug_guardpage_enabled())
712 if (order
>= debug_guardpage_minorder())
715 page_ext
= lookup_page_ext(page
);
716 if (unlikely(!page_ext
))
719 __set_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
721 INIT_LIST_HEAD(&page
->lru
);
722 set_page_private(page
, order
);
723 /* Guard pages are not available for any usage */
724 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
729 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
730 unsigned int order
, int migratetype
)
732 struct page_ext
*page_ext
;
734 if (!debug_guardpage_enabled())
737 page_ext
= lookup_page_ext(page
);
738 if (unlikely(!page_ext
))
741 __clear_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
743 set_page_private(page
, 0);
744 if (!is_migrate_isolate(migratetype
))
745 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
748 struct page_ext_operations debug_guardpage_ops
;
749 static inline bool set_page_guard(struct zone
*zone
, struct page
*page
,
750 unsigned int order
, int migratetype
) { return false; }
751 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
752 unsigned int order
, int migratetype
) {}
755 static inline void set_page_order(struct page
*page
, unsigned int order
)
757 set_page_private(page
, order
);
758 __SetPageBuddy(page
);
762 * This function checks whether a page is free && is the buddy
763 * we can coalesce a page and its buddy if
764 * (a) the buddy is not in a hole (check before calling!) &&
765 * (b) the buddy is in the buddy system &&
766 * (c) a page and its buddy have the same order &&
767 * (d) a page and its buddy are in the same zone.
769 * For recording whether a page is in the buddy system, we set PageBuddy.
770 * Setting, clearing, and testing PageBuddy is serialized by zone->lock.
772 * For recording page's order, we use page_private(page).
774 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
777 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
778 if (page_zone_id(page
) != page_zone_id(buddy
))
781 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
786 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
788 * zone check is done late to avoid uselessly
789 * calculating zone/node ids for pages that could
792 if (page_zone_id(page
) != page_zone_id(buddy
))
795 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
802 #ifdef CONFIG_COMPACTION
803 static inline struct capture_control
*task_capc(struct zone
*zone
)
805 struct capture_control
*capc
= current
->capture_control
;
808 !(current
->flags
& PF_KTHREAD
) &&
810 capc
->cc
->zone
== zone
&&
811 capc
->cc
->direct_compaction
? capc
: NULL
;
815 compaction_capture(struct capture_control
*capc
, struct page
*page
,
816 int order
, int migratetype
)
818 if (!capc
|| order
!= capc
->cc
->order
)
821 /* Do not accidentally pollute CMA or isolated regions*/
822 if (is_migrate_cma(migratetype
) ||
823 is_migrate_isolate(migratetype
))
827 * Do not let lower order allocations polluate a movable pageblock.
828 * This might let an unmovable request use a reclaimable pageblock
829 * and vice-versa but no more than normal fallback logic which can
830 * have trouble finding a high-order free page.
832 if (order
< pageblock_order
&& migratetype
== MIGRATE_MOVABLE
)
840 static inline struct capture_control
*task_capc(struct zone
*zone
)
846 compaction_capture(struct capture_control
*capc
, struct page
*page
,
847 int order
, int migratetype
)
851 #endif /* CONFIG_COMPACTION */
854 * Freeing function for a buddy system allocator.
856 * The concept of a buddy system is to maintain direct-mapped table
857 * (containing bit values) for memory blocks of various "orders".
858 * The bottom level table contains the map for the smallest allocatable
859 * units of memory (here, pages), and each level above it describes
860 * pairs of units from the levels below, hence, "buddies".
861 * At a high level, all that happens here is marking the table entry
862 * at the bottom level available, and propagating the changes upward
863 * as necessary, plus some accounting needed to play nicely with other
864 * parts of the VM system.
865 * At each level, we keep a list of pages, which are heads of continuous
866 * free pages of length of (1 << order) and marked with PageBuddy.
867 * Page's order is recorded in page_private(page) field.
868 * So when we are allocating or freeing one, we can derive the state of the
869 * other. That is, if we allocate a small block, and both were
870 * free, the remainder of the region must be split into blocks.
871 * If a block is freed, and its buddy is also free, then this
872 * triggers coalescing into a block of larger size.
877 static inline void __free_one_page(struct page
*page
,
879 struct zone
*zone
, unsigned int order
,
882 unsigned long combined_pfn
;
883 unsigned long uninitialized_var(buddy_pfn
);
885 unsigned int max_order
;
886 struct capture_control
*capc
= task_capc(zone
);
888 max_order
= min_t(unsigned int, MAX_ORDER
, pageblock_order
+ 1);
890 VM_BUG_ON(!zone_is_initialized(zone
));
891 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
893 VM_BUG_ON(migratetype
== -1);
894 if (likely(!is_migrate_isolate(migratetype
)))
895 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
897 VM_BUG_ON_PAGE(pfn
& ((1 << order
) - 1), page
);
898 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
901 while (order
< max_order
- 1) {
902 if (compaction_capture(capc
, page
, order
, migratetype
)) {
903 __mod_zone_freepage_state(zone
, -(1 << order
),
907 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
908 buddy
= page
+ (buddy_pfn
- pfn
);
910 if (!pfn_valid_within(buddy_pfn
))
912 if (!page_is_buddy(page
, buddy
, order
))
915 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
916 * merge with it and move up one order.
918 if (page_is_guard(buddy
))
919 clear_page_guard(zone
, buddy
, order
, migratetype
);
921 del_page_from_free_area(buddy
, &zone
->free_area
[order
]);
922 combined_pfn
= buddy_pfn
& pfn
;
923 page
= page
+ (combined_pfn
- pfn
);
927 if (max_order
< MAX_ORDER
) {
928 /* If we are here, it means order is >= pageblock_order.
929 * We want to prevent merge between freepages on isolate
930 * pageblock and normal pageblock. Without this, pageblock
931 * isolation could cause incorrect freepage or CMA accounting.
933 * We don't want to hit this code for the more frequent
936 if (unlikely(has_isolate_pageblock(zone
))) {
939 buddy_pfn
= __find_buddy_pfn(pfn
, order
);
940 buddy
= page
+ (buddy_pfn
- pfn
);
941 buddy_mt
= get_pageblock_migratetype(buddy
);
943 if (migratetype
!= buddy_mt
944 && (is_migrate_isolate(migratetype
) ||
945 is_migrate_isolate(buddy_mt
)))
949 goto continue_merging
;
953 set_page_order(page
, order
);
956 * If this is not the largest possible page, check if the buddy
957 * of the next-highest order is free. If it is, it's possible
958 * that pages are being freed that will coalesce soon. In case,
959 * that is happening, add the free page to the tail of the list
960 * so it's less likely to be used soon and more likely to be merged
961 * as a higher order page
963 if ((order
< MAX_ORDER
-2) && pfn_valid_within(buddy_pfn
)
964 && !is_shuffle_order(order
)) {
965 struct page
*higher_page
, *higher_buddy
;
966 combined_pfn
= buddy_pfn
& pfn
;
967 higher_page
= page
+ (combined_pfn
- pfn
);
968 buddy_pfn
= __find_buddy_pfn(combined_pfn
, order
+ 1);
969 higher_buddy
= higher_page
+ (buddy_pfn
- combined_pfn
);
970 if (pfn_valid_within(buddy_pfn
) &&
971 page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
972 add_to_free_area_tail(page
, &zone
->free_area
[order
],
978 if (is_shuffle_order(order
))
979 add_to_free_area_random(page
, &zone
->free_area
[order
],
982 add_to_free_area(page
, &zone
->free_area
[order
], migratetype
);
987 * A bad page could be due to a number of fields. Instead of multiple branches,
988 * try and check multiple fields with one check. The caller must do a detailed
989 * check if necessary.
991 static inline bool page_expected_state(struct page
*page
,
992 unsigned long check_flags
)
994 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
997 if (unlikely((unsigned long)page
->mapping
|
998 page_ref_count(page
) |
1000 (unsigned long)page
->mem_cgroup
|
1002 (page
->flags
& check_flags
)))
1008 static void free_pages_check_bad(struct page
*page
)
1010 const char *bad_reason
;
1011 unsigned long bad_flags
;
1016 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1017 bad_reason
= "nonzero mapcount";
1018 if (unlikely(page
->mapping
!= NULL
))
1019 bad_reason
= "non-NULL mapping";
1020 if (unlikely(page_ref_count(page
) != 0))
1021 bad_reason
= "nonzero _refcount";
1022 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
1023 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
1024 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
1027 if (unlikely(page
->mem_cgroup
))
1028 bad_reason
= "page still charged to cgroup";
1030 bad_page(page
, bad_reason
, bad_flags
);
1033 static inline int free_pages_check(struct page
*page
)
1035 if (likely(page_expected_state(page
, PAGE_FLAGS_CHECK_AT_FREE
)))
1038 /* Something has gone sideways, find it */
1039 free_pages_check_bad(page
);
1043 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
1048 * We rely page->lru.next never has bit 0 set, unless the page
1049 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
1051 BUILD_BUG_ON((unsigned long)LIST_POISON1
& 1);
1053 if (!IS_ENABLED(CONFIG_DEBUG_VM
)) {
1057 switch (page
- head_page
) {
1059 /* the first tail page: ->mapping may be compound_mapcount() */
1060 if (unlikely(compound_mapcount(page
))) {
1061 bad_page(page
, "nonzero compound_mapcount", 0);
1067 * the second tail page: ->mapping is
1068 * deferred_list.next -- ignore value.
1072 if (page
->mapping
!= TAIL_MAPPING
) {
1073 bad_page(page
, "corrupted mapping in tail page", 0);
1078 if (unlikely(!PageTail(page
))) {
1079 bad_page(page
, "PageTail not set", 0);
1082 if (unlikely(compound_head(page
) != head_page
)) {
1083 bad_page(page
, "compound_head not consistent", 0);
1088 page
->mapping
= NULL
;
1089 clear_compound_head(page
);
1093 static __always_inline
bool free_pages_prepare(struct page
*page
,
1094 unsigned int order
, bool check_free
)
1098 VM_BUG_ON_PAGE(PageTail(page
), page
);
1100 trace_mm_page_free(page
, order
);
1103 * Check tail pages before head page information is cleared to
1104 * avoid checking PageCompound for order-0 pages.
1106 if (unlikely(order
)) {
1107 bool compound
= PageCompound(page
);
1110 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
1113 ClearPageDoubleMap(page
);
1114 for (i
= 1; i
< (1 << order
); i
++) {
1116 bad
+= free_tail_pages_check(page
, page
+ i
);
1117 if (unlikely(free_pages_check(page
+ i
))) {
1121 (page
+ i
)->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1124 if (PageMappingFlags(page
))
1125 page
->mapping
= NULL
;
1126 if (memcg_kmem_enabled() && PageKmemcg(page
))
1127 __memcg_kmem_uncharge(page
, order
);
1129 bad
+= free_pages_check(page
);
1133 page_cpupid_reset_last(page
);
1134 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
1135 reset_page_owner(page
, order
);
1137 if (!PageHighMem(page
)) {
1138 debug_check_no_locks_freed(page_address(page
),
1139 PAGE_SIZE
<< order
);
1140 debug_check_no_obj_freed(page_address(page
),
1141 PAGE_SIZE
<< order
);
1143 arch_free_page(page
, order
);
1144 kernel_poison_pages(page
, 1 << order
, 0);
1145 if (debug_pagealloc_enabled())
1146 kernel_map_pages(page
, 1 << order
, 0);
1148 kasan_free_nondeferred_pages(page
, order
);
1153 #ifdef CONFIG_DEBUG_VM
1154 static inline bool free_pcp_prepare(struct page
*page
)
1156 return free_pages_prepare(page
, 0, true);
1159 static inline bool bulkfree_pcp_prepare(struct page
*page
)
1164 static bool free_pcp_prepare(struct page
*page
)
1166 return free_pages_prepare(page
, 0, false);
1169 static bool bulkfree_pcp_prepare(struct page
*page
)
1171 return free_pages_check(page
);
1173 #endif /* CONFIG_DEBUG_VM */
1175 static inline void prefetch_buddy(struct page
*page
)
1177 unsigned long pfn
= page_to_pfn(page
);
1178 unsigned long buddy_pfn
= __find_buddy_pfn(pfn
, 0);
1179 struct page
*buddy
= page
+ (buddy_pfn
- pfn
);
1185 * Frees a number of pages from the PCP lists
1186 * Assumes all pages on list are in same zone, and of same order.
1187 * count is the number of pages to free.
1189 * If the zone was previously in an "all pages pinned" state then look to
1190 * see if this freeing clears that state.
1192 * And clear the zone's pages_scanned counter, to hold off the "all pages are
1193 * pinned" detection logic.
1195 static void free_pcppages_bulk(struct zone
*zone
, int count
,
1196 struct per_cpu_pages
*pcp
)
1198 int migratetype
= 0;
1200 int prefetch_nr
= 0;
1201 bool isolated_pageblocks
;
1202 struct page
*page
, *tmp
;
1206 struct list_head
*list
;
1209 * Remove pages from lists in a round-robin fashion. A
1210 * batch_free count is maintained that is incremented when an
1211 * empty list is encountered. This is so more pages are freed
1212 * off fuller lists instead of spinning excessively around empty
1217 if (++migratetype
== MIGRATE_PCPTYPES
)
1219 list
= &pcp
->lists
[migratetype
];
1220 } while (list_empty(list
));
1222 /* This is the only non-empty list. Free them all. */
1223 if (batch_free
== MIGRATE_PCPTYPES
)
1227 page
= list_last_entry(list
, struct page
, lru
);
1228 /* must delete to avoid corrupting pcp list */
1229 list_del(&page
->lru
);
1232 if (bulkfree_pcp_prepare(page
))
1235 list_add_tail(&page
->lru
, &head
);
1238 * We are going to put the page back to the global
1239 * pool, prefetch its buddy to speed up later access
1240 * under zone->lock. It is believed the overhead of
1241 * an additional test and calculating buddy_pfn here
1242 * can be offset by reduced memory latency later. To
1243 * avoid excessive prefetching due to large count, only
1244 * prefetch buddy for the first pcp->batch nr of pages.
1246 if (prefetch_nr
++ < pcp
->batch
)
1247 prefetch_buddy(page
);
1248 } while (--count
&& --batch_free
&& !list_empty(list
));
1251 spin_lock(&zone
->lock
);
1252 isolated_pageblocks
= has_isolate_pageblock(zone
);
1255 * Use safe version since after __free_one_page(),
1256 * page->lru.next will not point to original list.
1258 list_for_each_entry_safe(page
, tmp
, &head
, lru
) {
1259 int mt
= get_pcppage_migratetype(page
);
1260 /* MIGRATE_ISOLATE page should not go to pcplists */
1261 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
1262 /* Pageblock could have been isolated meanwhile */
1263 if (unlikely(isolated_pageblocks
))
1264 mt
= get_pageblock_migratetype(page
);
1266 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
);
1267 trace_mm_page_pcpu_drain(page
, 0, mt
);
1269 spin_unlock(&zone
->lock
);
1272 static void free_one_page(struct zone
*zone
,
1273 struct page
*page
, unsigned long pfn
,
1277 spin_lock(&zone
->lock
);
1278 if (unlikely(has_isolate_pageblock(zone
) ||
1279 is_migrate_isolate(migratetype
))) {
1280 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1282 __free_one_page(page
, pfn
, zone
, order
, migratetype
);
1283 spin_unlock(&zone
->lock
);
1286 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
1287 unsigned long zone
, int nid
)
1289 mm_zero_struct_page(page
);
1290 set_page_links(page
, zone
, nid
, pfn
);
1291 init_page_count(page
);
1292 page_mapcount_reset(page
);
1293 page_cpupid_reset_last(page
);
1294 page_kasan_tag_reset(page
);
1296 INIT_LIST_HEAD(&page
->lru
);
1297 #ifdef WANT_PAGE_VIRTUAL
1298 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1299 if (!is_highmem_idx(zone
))
1300 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
1304 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1305 static void __meminit
init_reserved_page(unsigned long pfn
)
1310 if (!early_page_uninitialised(pfn
))
1313 nid
= early_pfn_to_nid(pfn
);
1314 pgdat
= NODE_DATA(nid
);
1316 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1317 struct zone
*zone
= &pgdat
->node_zones
[zid
];
1319 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
1322 __init_single_page(pfn_to_page(pfn
), pfn
, zid
, nid
);
1325 static inline void init_reserved_page(unsigned long pfn
)
1328 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1331 * Initialised pages do not have PageReserved set. This function is
1332 * called for each range allocated by the bootmem allocator and
1333 * marks the pages PageReserved. The remaining valid pages are later
1334 * sent to the buddy page allocator.
1336 void __meminit
reserve_bootmem_region(phys_addr_t start
, phys_addr_t end
)
1338 unsigned long start_pfn
= PFN_DOWN(start
);
1339 unsigned long end_pfn
= PFN_UP(end
);
1341 for (; start_pfn
< end_pfn
; start_pfn
++) {
1342 if (pfn_valid(start_pfn
)) {
1343 struct page
*page
= pfn_to_page(start_pfn
);
1345 init_reserved_page(start_pfn
);
1347 /* Avoid false-positive PageTail() */
1348 INIT_LIST_HEAD(&page
->lru
);
1351 * no need for atomic set_bit because the struct
1352 * page is not visible yet so nobody should
1355 __SetPageReserved(page
);
1360 static void __free_pages_ok(struct page
*page
, unsigned int order
)
1362 unsigned long flags
;
1364 unsigned long pfn
= page_to_pfn(page
);
1366 if (!free_pages_prepare(page
, order
, true))
1369 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1370 local_irq_save(flags
);
1371 __count_vm_events(PGFREE
, 1 << order
);
1372 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
1373 local_irq_restore(flags
);
1376 void __free_pages_core(struct page
*page
, unsigned int order
)
1378 unsigned int nr_pages
= 1 << order
;
1379 struct page
*p
= page
;
1383 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
1385 __ClearPageReserved(p
);
1386 set_page_count(p
, 0);
1388 __ClearPageReserved(p
);
1389 set_page_count(p
, 0);
1391 atomic_long_add(nr_pages
, &page_zone(page
)->managed_pages
);
1392 set_page_refcounted(page
);
1393 __free_pages(page
, order
);
1396 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1397 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1399 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1401 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1403 static DEFINE_SPINLOCK(early_pfn_lock
);
1406 spin_lock(&early_pfn_lock
);
1407 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1409 nid
= first_online_node
;
1410 spin_unlock(&early_pfn_lock
);
1416 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1417 /* Only safe to use early in boot when initialisation is single-threaded */
1418 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1422 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1423 if (nid
>= 0 && nid
!= node
)
1429 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1436 void __init
memblock_free_pages(struct page
*page
, unsigned long pfn
,
1439 if (early_page_uninitialised(pfn
))
1441 __free_pages_core(page
, order
);
1445 * Check that the whole (or subset of) a pageblock given by the interval of
1446 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1447 * with the migration of free compaction scanner. The scanners then need to
1448 * use only pfn_valid_within() check for arches that allow holes within
1451 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1453 * It's possible on some configurations to have a setup like node0 node1 node0
1454 * i.e. it's possible that all pages within a zones range of pages do not
1455 * belong to a single zone. We assume that a border between node0 and node1
1456 * can occur within a single pageblock, but not a node0 node1 node0
1457 * interleaving within a single pageblock. It is therefore sufficient to check
1458 * the first and last page of a pageblock and avoid checking each individual
1459 * page in a pageblock.
1461 struct page
*__pageblock_pfn_to_page(unsigned long start_pfn
,
1462 unsigned long end_pfn
, struct zone
*zone
)
1464 struct page
*start_page
;
1465 struct page
*end_page
;
1467 /* end_pfn is one past the range we are checking */
1470 if (!pfn_valid(start_pfn
) || !pfn_valid(end_pfn
))
1473 start_page
= pfn_to_online_page(start_pfn
);
1477 if (page_zone(start_page
) != zone
)
1480 end_page
= pfn_to_page(end_pfn
);
1482 /* This gives a shorter code than deriving page_zone(end_page) */
1483 if (page_zone_id(start_page
) != page_zone_id(end_page
))
1489 void set_zone_contiguous(struct zone
*zone
)
1491 unsigned long block_start_pfn
= zone
->zone_start_pfn
;
1492 unsigned long block_end_pfn
;
1494 block_end_pfn
= ALIGN(block_start_pfn
+ 1, pageblock_nr_pages
);
1495 for (; block_start_pfn
< zone_end_pfn(zone
);
1496 block_start_pfn
= block_end_pfn
,
1497 block_end_pfn
+= pageblock_nr_pages
) {
1499 block_end_pfn
= min(block_end_pfn
, zone_end_pfn(zone
));
1501 if (!__pageblock_pfn_to_page(block_start_pfn
,
1502 block_end_pfn
, zone
))
1506 /* We confirm that there is no hole */
1507 zone
->contiguous
= true;
1510 void clear_zone_contiguous(struct zone
*zone
)
1512 zone
->contiguous
= false;
1515 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1516 static void __init
deferred_free_range(unsigned long pfn
,
1517 unsigned long nr_pages
)
1525 page
= pfn_to_page(pfn
);
1527 /* Free a large naturally-aligned chunk if possible */
1528 if (nr_pages
== pageblock_nr_pages
&&
1529 (pfn
& (pageblock_nr_pages
- 1)) == 0) {
1530 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1531 __free_pages_core(page
, pageblock_order
);
1535 for (i
= 0; i
< nr_pages
; i
++, page
++, pfn
++) {
1536 if ((pfn
& (pageblock_nr_pages
- 1)) == 0)
1537 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1538 __free_pages_core(page
, 0);
1542 /* Completion tracking for deferred_init_memmap() threads */
1543 static atomic_t pgdat_init_n_undone __initdata
;
1544 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1546 static inline void __init
pgdat_init_report_one_done(void)
1548 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1549 complete(&pgdat_init_all_done_comp
);
1553 * Returns true if page needs to be initialized or freed to buddy allocator.
1555 * First we check if pfn is valid on architectures where it is possible to have
1556 * holes within pageblock_nr_pages. On systems where it is not possible, this
1557 * function is optimized out.
1559 * Then, we check if a current large page is valid by only checking the validity
1562 static inline bool __init
deferred_pfn_valid(unsigned long pfn
)
1564 if (!pfn_valid_within(pfn
))
1566 if (!(pfn
& (pageblock_nr_pages
- 1)) && !pfn_valid(pfn
))
1572 * Free pages to buddy allocator. Try to free aligned pages in
1573 * pageblock_nr_pages sizes.
1575 static void __init
deferred_free_pages(unsigned long pfn
,
1576 unsigned long end_pfn
)
1578 unsigned long nr_pgmask
= pageblock_nr_pages
- 1;
1579 unsigned long nr_free
= 0;
1581 for (; pfn
< end_pfn
; pfn
++) {
1582 if (!deferred_pfn_valid(pfn
)) {
1583 deferred_free_range(pfn
- nr_free
, nr_free
);
1585 } else if (!(pfn
& nr_pgmask
)) {
1586 deferred_free_range(pfn
- nr_free
, nr_free
);
1588 touch_nmi_watchdog();
1593 /* Free the last block of pages to allocator */
1594 deferred_free_range(pfn
- nr_free
, nr_free
);
1598 * Initialize struct pages. We minimize pfn page lookups and scheduler checks
1599 * by performing it only once every pageblock_nr_pages.
1600 * Return number of pages initialized.
1602 static unsigned long __init
deferred_init_pages(struct zone
*zone
,
1604 unsigned long end_pfn
)
1606 unsigned long nr_pgmask
= pageblock_nr_pages
- 1;
1607 int nid
= zone_to_nid(zone
);
1608 unsigned long nr_pages
= 0;
1609 int zid
= zone_idx(zone
);
1610 struct page
*page
= NULL
;
1612 for (; pfn
< end_pfn
; pfn
++) {
1613 if (!deferred_pfn_valid(pfn
)) {
1616 } else if (!page
|| !(pfn
& nr_pgmask
)) {
1617 page
= pfn_to_page(pfn
);
1618 touch_nmi_watchdog();
1622 __init_single_page(page
, pfn
, zid
, nid
);
1629 * This function is meant to pre-load the iterator for the zone init.
1630 * Specifically it walks through the ranges until we are caught up to the
1631 * first_init_pfn value and exits there. If we never encounter the value we
1632 * return false indicating there are no valid ranges left.
1635 deferred_init_mem_pfn_range_in_zone(u64
*i
, struct zone
*zone
,
1636 unsigned long *spfn
, unsigned long *epfn
,
1637 unsigned long first_init_pfn
)
1642 * Start out by walking through the ranges in this zone that have
1643 * already been initialized. We don't need to do anything with them
1644 * so we just need to flush them out of the system.
1646 for_each_free_mem_pfn_range_in_zone(j
, zone
, spfn
, epfn
) {
1647 if (*epfn
<= first_init_pfn
)
1649 if (*spfn
< first_init_pfn
)
1650 *spfn
= first_init_pfn
;
1659 * Initialize and free pages. We do it in two loops: first we initialize
1660 * struct page, then free to buddy allocator, because while we are
1661 * freeing pages we can access pages that are ahead (computing buddy
1662 * page in __free_one_page()).
1664 * In order to try and keep some memory in the cache we have the loop
1665 * broken along max page order boundaries. This way we will not cause
1666 * any issues with the buddy page computation.
1668 static unsigned long __init
1669 deferred_init_maxorder(u64
*i
, struct zone
*zone
, unsigned long *start_pfn
,
1670 unsigned long *end_pfn
)
1672 unsigned long mo_pfn
= ALIGN(*start_pfn
+ 1, MAX_ORDER_NR_PAGES
);
1673 unsigned long spfn
= *start_pfn
, epfn
= *end_pfn
;
1674 unsigned long nr_pages
= 0;
1677 /* First we loop through and initialize the page values */
1678 for_each_free_mem_pfn_range_in_zone_from(j
, zone
, start_pfn
, end_pfn
) {
1681 if (mo_pfn
<= *start_pfn
)
1684 t
= min(mo_pfn
, *end_pfn
);
1685 nr_pages
+= deferred_init_pages(zone
, *start_pfn
, t
);
1687 if (mo_pfn
< *end_pfn
) {
1688 *start_pfn
= mo_pfn
;
1693 /* Reset values and now loop through freeing pages as needed */
1696 for_each_free_mem_pfn_range_in_zone_from(j
, zone
, &spfn
, &epfn
) {
1702 t
= min(mo_pfn
, epfn
);
1703 deferred_free_pages(spfn
, t
);
1712 /* Initialise remaining memory on a node */
1713 static int __init
deferred_init_memmap(void *data
)
1715 pg_data_t
*pgdat
= data
;
1716 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1717 unsigned long spfn
= 0, epfn
= 0, nr_pages
= 0;
1718 unsigned long first_init_pfn
, flags
;
1719 unsigned long start
= jiffies
;
1724 /* Bind memory initialisation thread to a local node if possible */
1725 if (!cpumask_empty(cpumask
))
1726 set_cpus_allowed_ptr(current
, cpumask
);
1728 pgdat_resize_lock(pgdat
, &flags
);
1729 first_init_pfn
= pgdat
->first_deferred_pfn
;
1730 if (first_init_pfn
== ULONG_MAX
) {
1731 pgdat_resize_unlock(pgdat
, &flags
);
1732 pgdat_init_report_one_done();
1736 /* Sanity check boundaries */
1737 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1738 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1739 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1741 /* Only the highest zone is deferred so find it */
1742 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1743 zone
= pgdat
->node_zones
+ zid
;
1744 if (first_init_pfn
< zone_end_pfn(zone
))
1748 /* If the zone is empty somebody else may have cleared out the zone */
1749 if (!deferred_init_mem_pfn_range_in_zone(&i
, zone
, &spfn
, &epfn
,
1754 * Initialize and free pages in MAX_ORDER sized increments so
1755 * that we can avoid introducing any issues with the buddy
1759 nr_pages
+= deferred_init_maxorder(&i
, zone
, &spfn
, &epfn
);
1761 pgdat_resize_unlock(pgdat
, &flags
);
1763 /* Sanity check that the next zone really is unpopulated */
1764 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1766 pr_info("node %d initialised, %lu pages in %ums\n",
1767 pgdat
->node_id
, nr_pages
, jiffies_to_msecs(jiffies
- start
));
1769 pgdat_init_report_one_done();
1774 * If this zone has deferred pages, try to grow it by initializing enough
1775 * deferred pages to satisfy the allocation specified by order, rounded up to
1776 * the nearest PAGES_PER_SECTION boundary. So we're adding memory in increments
1777 * of SECTION_SIZE bytes by initializing struct pages in increments of
1778 * PAGES_PER_SECTION * sizeof(struct page) bytes.
1780 * Return true when zone was grown, otherwise return false. We return true even
1781 * when we grow less than requested, to let the caller decide if there are
1782 * enough pages to satisfy the allocation.
1784 * Note: We use noinline because this function is needed only during boot, and
1785 * it is called from a __ref function _deferred_grow_zone. This way we are
1786 * making sure that it is not inlined into permanent text section.
1788 static noinline
bool __init
1789 deferred_grow_zone(struct zone
*zone
, unsigned int order
)
1791 unsigned long nr_pages_needed
= ALIGN(1 << order
, PAGES_PER_SECTION
);
1792 pg_data_t
*pgdat
= zone
->zone_pgdat
;
1793 unsigned long first_deferred_pfn
= pgdat
->first_deferred_pfn
;
1794 unsigned long spfn
, epfn
, flags
;
1795 unsigned long nr_pages
= 0;
1798 /* Only the last zone may have deferred pages */
1799 if (zone_end_pfn(zone
) != pgdat_end_pfn(pgdat
))
1802 pgdat_resize_lock(pgdat
, &flags
);
1805 * If deferred pages have been initialized while we were waiting for
1806 * the lock, return true, as the zone was grown. The caller will retry
1807 * this zone. We won't return to this function since the caller also
1808 * has this static branch.
1810 if (!static_branch_unlikely(&deferred_pages
)) {
1811 pgdat_resize_unlock(pgdat
, &flags
);
1816 * If someone grew this zone while we were waiting for spinlock, return
1817 * true, as there might be enough pages already.
1819 if (first_deferred_pfn
!= pgdat
->first_deferred_pfn
) {
1820 pgdat_resize_unlock(pgdat
, &flags
);
1824 /* If the zone is empty somebody else may have cleared out the zone */
1825 if (!deferred_init_mem_pfn_range_in_zone(&i
, zone
, &spfn
, &epfn
,
1826 first_deferred_pfn
)) {
1827 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1828 pgdat_resize_unlock(pgdat
, &flags
);
1833 * Initialize and free pages in MAX_ORDER sized increments so
1834 * that we can avoid introducing any issues with the buddy
1837 while (spfn
< epfn
) {
1838 /* update our first deferred PFN for this section */
1839 first_deferred_pfn
= spfn
;
1841 nr_pages
+= deferred_init_maxorder(&i
, zone
, &spfn
, &epfn
);
1843 /* We should only stop along section boundaries */
1844 if ((first_deferred_pfn
^ spfn
) < PAGES_PER_SECTION
)
1847 /* If our quota has been met we can stop here */
1848 if (nr_pages
>= nr_pages_needed
)
1852 pgdat
->first_deferred_pfn
= spfn
;
1853 pgdat_resize_unlock(pgdat
, &flags
);
1855 return nr_pages
> 0;
1859 * deferred_grow_zone() is __init, but it is called from
1860 * get_page_from_freelist() during early boot until deferred_pages permanently
1861 * disables this call. This is why we have refdata wrapper to avoid warning,
1862 * and to ensure that the function body gets unloaded.
1865 _deferred_grow_zone(struct zone
*zone
, unsigned int order
)
1867 return deferred_grow_zone(zone
, order
);
1870 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1872 void __init
page_alloc_init_late(void)
1877 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1879 /* There will be num_node_state(N_MEMORY) threads */
1880 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
1881 for_each_node_state(nid
, N_MEMORY
) {
1882 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
1885 /* Block until all are initialised */
1886 wait_for_completion(&pgdat_init_all_done_comp
);
1889 * We initialized the rest of the deferred pages. Permanently disable
1890 * on-demand struct page initialization.
1892 static_branch_disable(&deferred_pages
);
1894 /* Reinit limits that are based on free pages after the kernel is up */
1895 files_maxfiles_init();
1898 /* Discard memblock private memory */
1901 for_each_node_state(nid
, N_MEMORY
)
1902 shuffle_free_memory(NODE_DATA(nid
));
1904 for_each_populated_zone(zone
)
1905 set_zone_contiguous(zone
);
1909 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1910 void __init
init_cma_reserved_pageblock(struct page
*page
)
1912 unsigned i
= pageblock_nr_pages
;
1913 struct page
*p
= page
;
1916 __ClearPageReserved(p
);
1917 set_page_count(p
, 0);
1920 set_pageblock_migratetype(page
, MIGRATE_CMA
);
1922 if (pageblock_order
>= MAX_ORDER
) {
1923 i
= pageblock_nr_pages
;
1926 set_page_refcounted(p
);
1927 __free_pages(p
, MAX_ORDER
- 1);
1928 p
+= MAX_ORDER_NR_PAGES
;
1929 } while (i
-= MAX_ORDER_NR_PAGES
);
1931 set_page_refcounted(page
);
1932 __free_pages(page
, pageblock_order
);
1935 adjust_managed_page_count(page
, pageblock_nr_pages
);
1940 * The order of subdivision here is critical for the IO subsystem.
1941 * Please do not alter this order without good reasons and regression
1942 * testing. Specifically, as large blocks of memory are subdivided,
1943 * the order in which smaller blocks are delivered depends on the order
1944 * they're subdivided in this function. This is the primary factor
1945 * influencing the order in which pages are delivered to the IO
1946 * subsystem according to empirical testing, and this is also justified
1947 * by considering the behavior of a buddy system containing a single
1948 * large block of memory acted on by a series of small allocations.
1949 * This behavior is a critical factor in sglist merging's success.
1953 static inline void expand(struct zone
*zone
, struct page
*page
,
1954 int low
, int high
, struct free_area
*area
,
1957 unsigned long size
= 1 << high
;
1959 while (high
> low
) {
1963 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
1966 * Mark as guard pages (or page), that will allow to
1967 * merge back to allocator when buddy will be freed.
1968 * Corresponding page table entries will not be touched,
1969 * pages will stay not present in virtual address space
1971 if (set_page_guard(zone
, &page
[size
], high
, migratetype
))
1974 add_to_free_area(&page
[size
], area
, migratetype
);
1975 set_page_order(&page
[size
], high
);
1979 static void check_new_page_bad(struct page
*page
)
1981 const char *bad_reason
= NULL
;
1982 unsigned long bad_flags
= 0;
1984 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1985 bad_reason
= "nonzero mapcount";
1986 if (unlikely(page
->mapping
!= NULL
))
1987 bad_reason
= "non-NULL mapping";
1988 if (unlikely(page_ref_count(page
) != 0))
1989 bad_reason
= "nonzero _refcount";
1990 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
1991 bad_reason
= "HWPoisoned (hardware-corrupted)";
1992 bad_flags
= __PG_HWPOISON
;
1993 /* Don't complain about hwpoisoned pages */
1994 page_mapcount_reset(page
); /* remove PageBuddy */
1997 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
1998 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
1999 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
2002 if (unlikely(page
->mem_cgroup
))
2003 bad_reason
= "page still charged to cgroup";
2005 bad_page(page
, bad_reason
, bad_flags
);
2009 * This page is about to be returned from the page allocator
2011 static inline int check_new_page(struct page
*page
)
2013 if (likely(page_expected_state(page
,
2014 PAGE_FLAGS_CHECK_AT_PREP
|__PG_HWPOISON
)))
2017 check_new_page_bad(page
);
2021 static inline bool free_pages_prezeroed(void)
2023 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO
) &&
2024 page_poisoning_enabled();
2027 #ifdef CONFIG_DEBUG_VM
2028 static bool check_pcp_refill(struct page
*page
)
2033 static bool check_new_pcp(struct page
*page
)
2035 return check_new_page(page
);
2038 static bool check_pcp_refill(struct page
*page
)
2040 return check_new_page(page
);
2042 static bool check_new_pcp(struct page
*page
)
2046 #endif /* CONFIG_DEBUG_VM */
2048 static bool check_new_pages(struct page
*page
, unsigned int order
)
2051 for (i
= 0; i
< (1 << order
); i
++) {
2052 struct page
*p
= page
+ i
;
2054 if (unlikely(check_new_page(p
)))
2061 inline void post_alloc_hook(struct page
*page
, unsigned int order
,
2064 set_page_private(page
, 0);
2065 set_page_refcounted(page
);
2067 arch_alloc_page(page
, order
);
2068 if (debug_pagealloc_enabled())
2069 kernel_map_pages(page
, 1 << order
, 1);
2070 kasan_alloc_pages(page
, order
);
2071 kernel_poison_pages(page
, 1 << order
, 1);
2072 set_page_owner(page
, order
, gfp_flags
);
2075 static void prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
2076 unsigned int alloc_flags
)
2080 post_alloc_hook(page
, order
, gfp_flags
);
2082 if (!free_pages_prezeroed() && (gfp_flags
& __GFP_ZERO
))
2083 for (i
= 0; i
< (1 << order
); i
++)
2084 clear_highpage(page
+ i
);
2086 if (order
&& (gfp_flags
& __GFP_COMP
))
2087 prep_compound_page(page
, order
);
2090 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
2091 * allocate the page. The expectation is that the caller is taking
2092 * steps that will free more memory. The caller should avoid the page
2093 * being used for !PFMEMALLOC purposes.
2095 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
2096 set_page_pfmemalloc(page
);
2098 clear_page_pfmemalloc(page
);
2102 * Go through the free lists for the given migratetype and remove
2103 * the smallest available page from the freelists
2105 static __always_inline
2106 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
2109 unsigned int current_order
;
2110 struct free_area
*area
;
2113 /* Find a page of the appropriate size in the preferred list */
2114 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
2115 area
= &(zone
->free_area
[current_order
]);
2116 page
= get_page_from_free_area(area
, migratetype
);
2119 del_page_from_free_area(page
, area
);
2120 expand(zone
, page
, order
, current_order
, area
, migratetype
);
2121 set_pcppage_migratetype(page
, migratetype
);
2130 * This array describes the order lists are fallen back to when
2131 * the free lists for the desirable migrate type are depleted
2133 static int fallbacks
[MIGRATE_TYPES
][4] = {
2134 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
2135 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_TYPES
},
2136 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
2138 [MIGRATE_CMA
] = { MIGRATE_TYPES
}, /* Never used */
2140 #ifdef CONFIG_MEMORY_ISOLATION
2141 [MIGRATE_ISOLATE
] = { MIGRATE_TYPES
}, /* Never used */
2146 static __always_inline
struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
2149 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
2152 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
2153 unsigned int order
) { return NULL
; }
2157 * Move the free pages in a range to the free lists of the requested type.
2158 * Note that start_page and end_pages are not aligned on a pageblock
2159 * boundary. If alignment is required, use move_freepages_block()
2161 static int move_freepages(struct zone
*zone
,
2162 struct page
*start_page
, struct page
*end_page
,
2163 int migratetype
, int *num_movable
)
2167 int pages_moved
= 0;
2169 #ifndef CONFIG_HOLES_IN_ZONE
2171 * page_zone is not safe to call in this context when
2172 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
2173 * anyway as we check zone boundaries in move_freepages_block().
2174 * Remove at a later date when no bug reports exist related to
2175 * grouping pages by mobility
2177 VM_BUG_ON(pfn_valid(page_to_pfn(start_page
)) &&
2178 pfn_valid(page_to_pfn(end_page
)) &&
2179 page_zone(start_page
) != page_zone(end_page
));
2181 for (page
= start_page
; page
<= end_page
;) {
2182 if (!pfn_valid_within(page_to_pfn(page
))) {
2187 /* Make sure we are not inadvertently changing nodes */
2188 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
2190 if (!PageBuddy(page
)) {
2192 * We assume that pages that could be isolated for
2193 * migration are movable. But we don't actually try
2194 * isolating, as that would be expensive.
2197 (PageLRU(page
) || __PageMovable(page
)))
2204 order
= page_order(page
);
2205 move_to_free_area(page
, &zone
->free_area
[order
], migratetype
);
2207 pages_moved
+= 1 << order
;
2213 int move_freepages_block(struct zone
*zone
, struct page
*page
,
2214 int migratetype
, int *num_movable
)
2216 unsigned long start_pfn
, end_pfn
;
2217 struct page
*start_page
, *end_page
;
2222 start_pfn
= page_to_pfn(page
);
2223 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
2224 start_page
= pfn_to_page(start_pfn
);
2225 end_page
= start_page
+ pageblock_nr_pages
- 1;
2226 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
2228 /* Do not cross zone boundaries */
2229 if (!zone_spans_pfn(zone
, start_pfn
))
2231 if (!zone_spans_pfn(zone
, end_pfn
))
2234 return move_freepages(zone
, start_page
, end_page
, migratetype
,
2238 static void change_pageblock_range(struct page
*pageblock_page
,
2239 int start_order
, int migratetype
)
2241 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
2243 while (nr_pageblocks
--) {
2244 set_pageblock_migratetype(pageblock_page
, migratetype
);
2245 pageblock_page
+= pageblock_nr_pages
;
2250 * When we are falling back to another migratetype during allocation, try to
2251 * steal extra free pages from the same pageblocks to satisfy further
2252 * allocations, instead of polluting multiple pageblocks.
2254 * If we are stealing a relatively large buddy page, it is likely there will
2255 * be more free pages in the pageblock, so try to steal them all. For
2256 * reclaimable and unmovable allocations, we steal regardless of page size,
2257 * as fragmentation caused by those allocations polluting movable pageblocks
2258 * is worse than movable allocations stealing from unmovable and reclaimable
2261 static bool can_steal_fallback(unsigned int order
, int start_mt
)
2264 * Leaving this order check is intended, although there is
2265 * relaxed order check in next check. The reason is that
2266 * we can actually steal whole pageblock if this condition met,
2267 * but, below check doesn't guarantee it and that is just heuristic
2268 * so could be changed anytime.
2270 if (order
>= pageblock_order
)
2273 if (order
>= pageblock_order
/ 2 ||
2274 start_mt
== MIGRATE_RECLAIMABLE
||
2275 start_mt
== MIGRATE_UNMOVABLE
||
2276 page_group_by_mobility_disabled
)
2282 static inline void boost_watermark(struct zone
*zone
)
2284 unsigned long max_boost
;
2286 if (!watermark_boost_factor
)
2289 max_boost
= mult_frac(zone
->_watermark
[WMARK_HIGH
],
2290 watermark_boost_factor
, 10000);
2293 * high watermark may be uninitialised if fragmentation occurs
2294 * very early in boot so do not boost. We do not fall
2295 * through and boost by pageblock_nr_pages as failing
2296 * allocations that early means that reclaim is not going
2297 * to help and it may even be impossible to reclaim the
2298 * boosted watermark resulting in a hang.
2303 max_boost
= max(pageblock_nr_pages
, max_boost
);
2305 zone
->watermark_boost
= min(zone
->watermark_boost
+ pageblock_nr_pages
,
2310 * This function implements actual steal behaviour. If order is large enough,
2311 * we can steal whole pageblock. If not, we first move freepages in this
2312 * pageblock to our migratetype and determine how many already-allocated pages
2313 * are there in the pageblock with a compatible migratetype. If at least half
2314 * of pages are free or compatible, we can change migratetype of the pageblock
2315 * itself, so pages freed in the future will be put on the correct free list.
2317 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
2318 unsigned int alloc_flags
, int start_type
, bool whole_block
)
2320 unsigned int current_order
= page_order(page
);
2321 struct free_area
*area
;
2322 int free_pages
, movable_pages
, alike_pages
;
2325 old_block_type
= get_pageblock_migratetype(page
);
2328 * This can happen due to races and we want to prevent broken
2329 * highatomic accounting.
2331 if (is_migrate_highatomic(old_block_type
))
2334 /* Take ownership for orders >= pageblock_order */
2335 if (current_order
>= pageblock_order
) {
2336 change_pageblock_range(page
, current_order
, start_type
);
2341 * Boost watermarks to increase reclaim pressure to reduce the
2342 * likelihood of future fallbacks. Wake kswapd now as the node
2343 * may be balanced overall and kswapd will not wake naturally.
2345 boost_watermark(zone
);
2346 if (alloc_flags
& ALLOC_KSWAPD
)
2347 set_bit(ZONE_BOOSTED_WATERMARK
, &zone
->flags
);
2349 /* We are not allowed to try stealing from the whole block */
2353 free_pages
= move_freepages_block(zone
, page
, start_type
,
2356 * Determine how many pages are compatible with our allocation.
2357 * For movable allocation, it's the number of movable pages which
2358 * we just obtained. For other types it's a bit more tricky.
2360 if (start_type
== MIGRATE_MOVABLE
) {
2361 alike_pages
= movable_pages
;
2364 * If we are falling back a RECLAIMABLE or UNMOVABLE allocation
2365 * to MOVABLE pageblock, consider all non-movable pages as
2366 * compatible. If it's UNMOVABLE falling back to RECLAIMABLE or
2367 * vice versa, be conservative since we can't distinguish the
2368 * exact migratetype of non-movable pages.
2370 if (old_block_type
== MIGRATE_MOVABLE
)
2371 alike_pages
= pageblock_nr_pages
2372 - (free_pages
+ movable_pages
);
2377 /* moving whole block can fail due to zone boundary conditions */
2382 * If a sufficient number of pages in the block are either free or of
2383 * comparable migratability as our allocation, claim the whole block.
2385 if (free_pages
+ alike_pages
>= (1 << (pageblock_order
-1)) ||
2386 page_group_by_mobility_disabled
)
2387 set_pageblock_migratetype(page
, start_type
);
2392 area
= &zone
->free_area
[current_order
];
2393 move_to_free_area(page
, area
, start_type
);
2397 * Check whether there is a suitable fallback freepage with requested order.
2398 * If only_stealable is true, this function returns fallback_mt only if
2399 * we can steal other freepages all together. This would help to reduce
2400 * fragmentation due to mixed migratetype pages in one pageblock.
2402 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
2403 int migratetype
, bool only_stealable
, bool *can_steal
)
2408 if (area
->nr_free
== 0)
2413 fallback_mt
= fallbacks
[migratetype
][i
];
2414 if (fallback_mt
== MIGRATE_TYPES
)
2417 if (free_area_empty(area
, fallback_mt
))
2420 if (can_steal_fallback(order
, migratetype
))
2423 if (!only_stealable
)
2434 * Reserve a pageblock for exclusive use of high-order atomic allocations if
2435 * there are no empty page blocks that contain a page with a suitable order
2437 static void reserve_highatomic_pageblock(struct page
*page
, struct zone
*zone
,
2438 unsigned int alloc_order
)
2441 unsigned long max_managed
, flags
;
2444 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
2445 * Check is race-prone but harmless.
2447 max_managed
= (zone_managed_pages(zone
) / 100) + pageblock_nr_pages
;
2448 if (zone
->nr_reserved_highatomic
>= max_managed
)
2451 spin_lock_irqsave(&zone
->lock
, flags
);
2453 /* Recheck the nr_reserved_highatomic limit under the lock */
2454 if (zone
->nr_reserved_highatomic
>= max_managed
)
2458 mt
= get_pageblock_migratetype(page
);
2459 if (!is_migrate_highatomic(mt
) && !is_migrate_isolate(mt
)
2460 && !is_migrate_cma(mt
)) {
2461 zone
->nr_reserved_highatomic
+= pageblock_nr_pages
;
2462 set_pageblock_migratetype(page
, MIGRATE_HIGHATOMIC
);
2463 move_freepages_block(zone
, page
, MIGRATE_HIGHATOMIC
, NULL
);
2467 spin_unlock_irqrestore(&zone
->lock
, flags
);
2471 * Used when an allocation is about to fail under memory pressure. This
2472 * potentially hurts the reliability of high-order allocations when under
2473 * intense memory pressure but failed atomic allocations should be easier
2474 * to recover from than an OOM.
2476 * If @force is true, try to unreserve a pageblock even though highatomic
2477 * pageblock is exhausted.
2479 static bool unreserve_highatomic_pageblock(const struct alloc_context
*ac
,
2482 struct zonelist
*zonelist
= ac
->zonelist
;
2483 unsigned long flags
;
2490 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
2493 * Preserve at least one pageblock unless memory pressure
2496 if (!force
&& zone
->nr_reserved_highatomic
<=
2500 spin_lock_irqsave(&zone
->lock
, flags
);
2501 for (order
= 0; order
< MAX_ORDER
; order
++) {
2502 struct free_area
*area
= &(zone
->free_area
[order
]);
2504 page
= get_page_from_free_area(area
, MIGRATE_HIGHATOMIC
);
2509 * In page freeing path, migratetype change is racy so
2510 * we can counter several free pages in a pageblock
2511 * in this loop althoug we changed the pageblock type
2512 * from highatomic to ac->migratetype. So we should
2513 * adjust the count once.
2515 if (is_migrate_highatomic_page(page
)) {
2517 * It should never happen but changes to
2518 * locking could inadvertently allow a per-cpu
2519 * drain to add pages to MIGRATE_HIGHATOMIC
2520 * while unreserving so be safe and watch for
2523 zone
->nr_reserved_highatomic
-= min(
2525 zone
->nr_reserved_highatomic
);
2529 * Convert to ac->migratetype and avoid the normal
2530 * pageblock stealing heuristics. Minimally, the caller
2531 * is doing the work and needs the pages. More
2532 * importantly, if the block was always converted to
2533 * MIGRATE_UNMOVABLE or another type then the number
2534 * of pageblocks that cannot be completely freed
2537 set_pageblock_migratetype(page
, ac
->migratetype
);
2538 ret
= move_freepages_block(zone
, page
, ac
->migratetype
,
2541 spin_unlock_irqrestore(&zone
->lock
, flags
);
2545 spin_unlock_irqrestore(&zone
->lock
, flags
);
2552 * Try finding a free buddy page on the fallback list and put it on the free
2553 * list of requested migratetype, possibly along with other pages from the same
2554 * block, depending on fragmentation avoidance heuristics. Returns true if
2555 * fallback was found so that __rmqueue_smallest() can grab it.
2557 * The use of signed ints for order and current_order is a deliberate
2558 * deviation from the rest of this file, to make the for loop
2559 * condition simpler.
2561 static __always_inline
bool
2562 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
,
2563 unsigned int alloc_flags
)
2565 struct free_area
*area
;
2567 int min_order
= order
;
2573 * Do not steal pages from freelists belonging to other pageblocks
2574 * i.e. orders < pageblock_order. If there are no local zones free,
2575 * the zonelists will be reiterated without ALLOC_NOFRAGMENT.
2577 if (alloc_flags
& ALLOC_NOFRAGMENT
)
2578 min_order
= pageblock_order
;
2581 * Find the largest available free page in the other list. This roughly
2582 * approximates finding the pageblock with the most free pages, which
2583 * would be too costly to do exactly.
2585 for (current_order
= MAX_ORDER
- 1; current_order
>= min_order
;
2587 area
= &(zone
->free_area
[current_order
]);
2588 fallback_mt
= find_suitable_fallback(area
, current_order
,
2589 start_migratetype
, false, &can_steal
);
2590 if (fallback_mt
== -1)
2594 * We cannot steal all free pages from the pageblock and the
2595 * requested migratetype is movable. In that case it's better to
2596 * steal and split the smallest available page instead of the
2597 * largest available page, because even if the next movable
2598 * allocation falls back into a different pageblock than this
2599 * one, it won't cause permanent fragmentation.
2601 if (!can_steal
&& start_migratetype
== MIGRATE_MOVABLE
2602 && current_order
> order
)
2611 for (current_order
= order
; current_order
< MAX_ORDER
;
2613 area
= &(zone
->free_area
[current_order
]);
2614 fallback_mt
= find_suitable_fallback(area
, current_order
,
2615 start_migratetype
, false, &can_steal
);
2616 if (fallback_mt
!= -1)
2621 * This should not happen - we already found a suitable fallback
2622 * when looking for the largest page.
2624 VM_BUG_ON(current_order
== MAX_ORDER
);
2627 page
= get_page_from_free_area(area
, fallback_mt
);
2629 steal_suitable_fallback(zone
, page
, alloc_flags
, start_migratetype
,
2632 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
2633 start_migratetype
, fallback_mt
);
2640 * Do the hard work of removing an element from the buddy allocator.
2641 * Call me with the zone->lock already held.
2643 static __always_inline
struct page
*
2644 __rmqueue(struct zone
*zone
, unsigned int order
, int migratetype
,
2645 unsigned int alloc_flags
)
2650 page
= __rmqueue_smallest(zone
, order
, migratetype
);
2651 if (unlikely(!page
)) {
2652 if (migratetype
== MIGRATE_MOVABLE
)
2653 page
= __rmqueue_cma_fallback(zone
, order
);
2655 if (!page
&& __rmqueue_fallback(zone
, order
, migratetype
,
2660 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2665 * Obtain a specified number of elements from the buddy allocator, all under
2666 * a single hold of the lock, for efficiency. Add them to the supplied list.
2667 * Returns the number of new pages which were placed at *list.
2669 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
2670 unsigned long count
, struct list_head
*list
,
2671 int migratetype
, unsigned int alloc_flags
)
2675 spin_lock(&zone
->lock
);
2676 for (i
= 0; i
< count
; ++i
) {
2677 struct page
*page
= __rmqueue(zone
, order
, migratetype
,
2679 if (unlikely(page
== NULL
))
2682 if (unlikely(check_pcp_refill(page
)))
2686 * Split buddy pages returned by expand() are received here in
2687 * physical page order. The page is added to the tail of
2688 * caller's list. From the callers perspective, the linked list
2689 * is ordered by page number under some conditions. This is
2690 * useful for IO devices that can forward direction from the
2691 * head, thus also in the physical page order. This is useful
2692 * for IO devices that can merge IO requests if the physical
2693 * pages are ordered properly.
2695 list_add_tail(&page
->lru
, list
);
2697 if (is_migrate_cma(get_pcppage_migratetype(page
)))
2698 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
2703 * i pages were removed from the buddy list even if some leak due
2704 * to check_pcp_refill failing so adjust NR_FREE_PAGES based
2705 * on i. Do not confuse with 'alloced' which is the number of
2706 * pages added to the pcp list.
2708 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
2709 spin_unlock(&zone
->lock
);
2715 * Called from the vmstat counter updater to drain pagesets of this
2716 * currently executing processor on remote nodes after they have
2719 * Note that this function must be called with the thread pinned to
2720 * a single processor.
2722 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
2724 unsigned long flags
;
2725 int to_drain
, batch
;
2727 local_irq_save(flags
);
2728 batch
= READ_ONCE(pcp
->batch
);
2729 to_drain
= min(pcp
->count
, batch
);
2731 free_pcppages_bulk(zone
, to_drain
, pcp
);
2732 local_irq_restore(flags
);
2737 * Drain pcplists of the indicated processor and zone.
2739 * The processor must either be the current processor and the
2740 * thread pinned to the current processor or a processor that
2743 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
2745 unsigned long flags
;
2746 struct per_cpu_pageset
*pset
;
2747 struct per_cpu_pages
*pcp
;
2749 local_irq_save(flags
);
2750 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
2754 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
2755 local_irq_restore(flags
);
2759 * Drain pcplists of all zones on the indicated processor.
2761 * The processor must either be the current processor and the
2762 * thread pinned to the current processor or a processor that
2765 static void drain_pages(unsigned int cpu
)
2769 for_each_populated_zone(zone
) {
2770 drain_pages_zone(cpu
, zone
);
2775 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2777 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2778 * the single zone's pages.
2780 void drain_local_pages(struct zone
*zone
)
2782 int cpu
= smp_processor_id();
2785 drain_pages_zone(cpu
, zone
);
2790 static void drain_local_pages_wq(struct work_struct
*work
)
2792 struct pcpu_drain
*drain
;
2794 drain
= container_of(work
, struct pcpu_drain
, work
);
2797 * drain_all_pages doesn't use proper cpu hotplug protection so
2798 * we can race with cpu offline when the WQ can move this from
2799 * a cpu pinned worker to an unbound one. We can operate on a different
2800 * cpu which is allright but we also have to make sure to not move to
2804 drain_local_pages(drain
->zone
);
2809 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2811 * When zone parameter is non-NULL, spill just the single zone's pages.
2813 * Note that this can be extremely slow as the draining happens in a workqueue.
2815 void drain_all_pages(struct zone
*zone
)
2820 * Allocate in the BSS so we wont require allocation in
2821 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2823 static cpumask_t cpus_with_pcps
;
2826 * Make sure nobody triggers this path before mm_percpu_wq is fully
2829 if (WARN_ON_ONCE(!mm_percpu_wq
))
2833 * Do not drain if one is already in progress unless it's specific to
2834 * a zone. Such callers are primarily CMA and memory hotplug and need
2835 * the drain to be complete when the call returns.
2837 if (unlikely(!mutex_trylock(&pcpu_drain_mutex
))) {
2840 mutex_lock(&pcpu_drain_mutex
);
2844 * We don't care about racing with CPU hotplug event
2845 * as offline notification will cause the notified
2846 * cpu to drain that CPU pcps and on_each_cpu_mask
2847 * disables preemption as part of its processing
2849 for_each_online_cpu(cpu
) {
2850 struct per_cpu_pageset
*pcp
;
2852 bool has_pcps
= false;
2855 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
2859 for_each_populated_zone(z
) {
2860 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
2861 if (pcp
->pcp
.count
) {
2869 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
2871 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
2874 for_each_cpu(cpu
, &cpus_with_pcps
) {
2875 struct pcpu_drain
*drain
= per_cpu_ptr(&pcpu_drain
, cpu
);
2878 INIT_WORK(&drain
->work
, drain_local_pages_wq
);
2879 queue_work_on(cpu
, mm_percpu_wq
, &drain
->work
);
2881 for_each_cpu(cpu
, &cpus_with_pcps
)
2882 flush_work(&per_cpu_ptr(&pcpu_drain
, cpu
)->work
);
2884 mutex_unlock(&pcpu_drain_mutex
);
2887 #ifdef CONFIG_HIBERNATION
2890 * Touch the watchdog for every WD_PAGE_COUNT pages.
2892 #define WD_PAGE_COUNT (128*1024)
2894 void mark_free_pages(struct zone
*zone
)
2896 unsigned long pfn
, max_zone_pfn
, page_count
= WD_PAGE_COUNT
;
2897 unsigned long flags
;
2898 unsigned int order
, t
;
2901 if (zone_is_empty(zone
))
2904 spin_lock_irqsave(&zone
->lock
, flags
);
2906 max_zone_pfn
= zone_end_pfn(zone
);
2907 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
2908 if (pfn_valid(pfn
)) {
2909 page
= pfn_to_page(pfn
);
2911 if (!--page_count
) {
2912 touch_nmi_watchdog();
2913 page_count
= WD_PAGE_COUNT
;
2916 if (page_zone(page
) != zone
)
2919 if (!swsusp_page_is_forbidden(page
))
2920 swsusp_unset_page_free(page
);
2923 for_each_migratetype_order(order
, t
) {
2924 list_for_each_entry(page
,
2925 &zone
->free_area
[order
].free_list
[t
], lru
) {
2928 pfn
= page_to_pfn(page
);
2929 for (i
= 0; i
< (1UL << order
); i
++) {
2930 if (!--page_count
) {
2931 touch_nmi_watchdog();
2932 page_count
= WD_PAGE_COUNT
;
2934 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
2938 spin_unlock_irqrestore(&zone
->lock
, flags
);
2940 #endif /* CONFIG_PM */
2942 static bool free_unref_page_prepare(struct page
*page
, unsigned long pfn
)
2946 if (!free_pcp_prepare(page
))
2949 migratetype
= get_pfnblock_migratetype(page
, pfn
);
2950 set_pcppage_migratetype(page
, migratetype
);
2954 static void free_unref_page_commit(struct page
*page
, unsigned long pfn
)
2956 struct zone
*zone
= page_zone(page
);
2957 struct per_cpu_pages
*pcp
;
2960 migratetype
= get_pcppage_migratetype(page
);
2961 __count_vm_event(PGFREE
);
2964 * We only track unmovable, reclaimable and movable on pcp lists.
2965 * Free ISOLATE pages back to the allocator because they are being
2966 * offlined but treat HIGHATOMIC as movable pages so we can get those
2967 * areas back if necessary. Otherwise, we may have to free
2968 * excessively into the page allocator
2970 if (migratetype
>= MIGRATE_PCPTYPES
) {
2971 if (unlikely(is_migrate_isolate(migratetype
))) {
2972 free_one_page(zone
, page
, pfn
, 0, migratetype
);
2975 migratetype
= MIGRATE_MOVABLE
;
2978 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2979 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
2981 if (pcp
->count
>= pcp
->high
) {
2982 unsigned long batch
= READ_ONCE(pcp
->batch
);
2983 free_pcppages_bulk(zone
, batch
, pcp
);
2988 * Free a 0-order page
2990 void free_unref_page(struct page
*page
)
2992 unsigned long flags
;
2993 unsigned long pfn
= page_to_pfn(page
);
2995 if (!free_unref_page_prepare(page
, pfn
))
2998 local_irq_save(flags
);
2999 free_unref_page_commit(page
, pfn
);
3000 local_irq_restore(flags
);
3004 * Free a list of 0-order pages
3006 void free_unref_page_list(struct list_head
*list
)
3008 struct page
*page
, *next
;
3009 unsigned long flags
, pfn
;
3010 int batch_count
= 0;
3012 /* Prepare pages for freeing */
3013 list_for_each_entry_safe(page
, next
, list
, lru
) {
3014 pfn
= page_to_pfn(page
);
3015 if (!free_unref_page_prepare(page
, pfn
))
3016 list_del(&page
->lru
);
3017 set_page_private(page
, pfn
);
3020 local_irq_save(flags
);
3021 list_for_each_entry_safe(page
, next
, list
, lru
) {
3022 unsigned long pfn
= page_private(page
);
3024 set_page_private(page
, 0);
3025 trace_mm_page_free_batched(page
);
3026 free_unref_page_commit(page
, pfn
);
3029 * Guard against excessive IRQ disabled times when we get
3030 * a large list of pages to free.
3032 if (++batch_count
== SWAP_CLUSTER_MAX
) {
3033 local_irq_restore(flags
);
3035 local_irq_save(flags
);
3038 local_irq_restore(flags
);
3042 * split_page takes a non-compound higher-order page, and splits it into
3043 * n (1<<order) sub-pages: page[0..n]
3044 * Each sub-page must be freed individually.
3046 * Note: this is probably too low level an operation for use in drivers.
3047 * Please consult with lkml before using this in your driver.
3049 void split_page(struct page
*page
, unsigned int order
)
3053 VM_BUG_ON_PAGE(PageCompound(page
), page
);
3054 VM_BUG_ON_PAGE(!page_count(page
), page
);
3056 for (i
= 1; i
< (1 << order
); i
++)
3057 set_page_refcounted(page
+ i
);
3058 split_page_owner(page
, order
);
3060 EXPORT_SYMBOL_GPL(split_page
);
3062 int __isolate_free_page(struct page
*page
, unsigned int order
)
3064 struct free_area
*area
= &page_zone(page
)->free_area
[order
];
3065 unsigned long watermark
;
3069 BUG_ON(!PageBuddy(page
));
3071 zone
= page_zone(page
);
3072 mt
= get_pageblock_migratetype(page
);
3074 if (!is_migrate_isolate(mt
)) {
3076 * Obey watermarks as if the page was being allocated. We can
3077 * emulate a high-order watermark check with a raised order-0
3078 * watermark, because we already know our high-order page
3081 watermark
= zone
->_watermark
[WMARK_MIN
] + (1UL << order
);
3082 if (!zone_watermark_ok(zone
, 0, watermark
, 0, ALLOC_CMA
))
3085 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
3088 /* Remove page from free list */
3090 del_page_from_free_area(page
, area
);
3093 * Set the pageblock if the isolated page is at least half of a
3096 if (order
>= pageblock_order
- 1) {
3097 struct page
*endpage
= page
+ (1 << order
) - 1;
3098 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
3099 int mt
= get_pageblock_migratetype(page
);
3100 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
)
3101 && !is_migrate_highatomic(mt
))
3102 set_pageblock_migratetype(page
,
3108 return 1UL << order
;
3112 * Update NUMA hit/miss statistics
3114 * Must be called with interrupts disabled.
3116 static inline void zone_statistics(struct zone
*preferred_zone
, struct zone
*z
)
3119 enum numa_stat_item local_stat
= NUMA_LOCAL
;
3121 /* skip numa counters update if numa stats is disabled */
3122 if (!static_branch_likely(&vm_numa_stat_key
))
3125 if (zone_to_nid(z
) != numa_node_id())
3126 local_stat
= NUMA_OTHER
;
3128 if (zone_to_nid(z
) == zone_to_nid(preferred_zone
))
3129 __inc_numa_state(z
, NUMA_HIT
);
3131 __inc_numa_state(z
, NUMA_MISS
);
3132 __inc_numa_state(preferred_zone
, NUMA_FOREIGN
);
3134 __inc_numa_state(z
, local_stat
);
3138 /* Remove page from the per-cpu list, caller must protect the list */
3139 static struct page
*__rmqueue_pcplist(struct zone
*zone
, int migratetype
,
3140 unsigned int alloc_flags
,
3141 struct per_cpu_pages
*pcp
,
3142 struct list_head
*list
)
3147 if (list_empty(list
)) {
3148 pcp
->count
+= rmqueue_bulk(zone
, 0,
3150 migratetype
, alloc_flags
);
3151 if (unlikely(list_empty(list
)))
3155 page
= list_first_entry(list
, struct page
, lru
);
3156 list_del(&page
->lru
);
3158 } while (check_new_pcp(page
));
3163 /* Lock and remove page from the per-cpu list */
3164 static struct page
*rmqueue_pcplist(struct zone
*preferred_zone
,
3165 struct zone
*zone
, gfp_t gfp_flags
,
3166 int migratetype
, unsigned int alloc_flags
)
3168 struct per_cpu_pages
*pcp
;
3169 struct list_head
*list
;
3171 unsigned long flags
;
3173 local_irq_save(flags
);
3174 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
3175 list
= &pcp
->lists
[migratetype
];
3176 page
= __rmqueue_pcplist(zone
, migratetype
, alloc_flags
, pcp
, list
);
3178 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1);
3179 zone_statistics(preferred_zone
, zone
);
3181 local_irq_restore(flags
);
3186 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
3189 struct page
*rmqueue(struct zone
*preferred_zone
,
3190 struct zone
*zone
, unsigned int order
,
3191 gfp_t gfp_flags
, unsigned int alloc_flags
,
3194 unsigned long flags
;
3197 if (likely(order
== 0)) {
3198 page
= rmqueue_pcplist(preferred_zone
, zone
, gfp_flags
,
3199 migratetype
, alloc_flags
);
3204 * We most definitely don't want callers attempting to
3205 * allocate greater than order-1 page units with __GFP_NOFAIL.
3207 WARN_ON_ONCE((gfp_flags
& __GFP_NOFAIL
) && (order
> 1));
3208 spin_lock_irqsave(&zone
->lock
, flags
);
3212 if (alloc_flags
& ALLOC_HARDER
) {
3213 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
3215 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
3218 page
= __rmqueue(zone
, order
, migratetype
, alloc_flags
);
3219 } while (page
&& check_new_pages(page
, order
));
3220 spin_unlock(&zone
->lock
);
3223 __mod_zone_freepage_state(zone
, -(1 << order
),
3224 get_pcppage_migratetype(page
));
3226 __count_zid_vm_events(PGALLOC
, page_zonenum(page
), 1 << order
);
3227 zone_statistics(preferred_zone
, zone
);
3228 local_irq_restore(flags
);
3231 /* Separate test+clear to avoid unnecessary atomics */
3232 if (test_bit(ZONE_BOOSTED_WATERMARK
, &zone
->flags
)) {
3233 clear_bit(ZONE_BOOSTED_WATERMARK
, &zone
->flags
);
3234 wakeup_kswapd(zone
, 0, 0, zone_idx(zone
));
3237 VM_BUG_ON_PAGE(page
&& bad_range(zone
, page
), page
);
3241 local_irq_restore(flags
);
3245 #ifdef CONFIG_FAIL_PAGE_ALLOC
3248 struct fault_attr attr
;
3250 bool ignore_gfp_highmem
;
3251 bool ignore_gfp_reclaim
;
3253 } fail_page_alloc
= {
3254 .attr
= FAULT_ATTR_INITIALIZER
,
3255 .ignore_gfp_reclaim
= true,
3256 .ignore_gfp_highmem
= true,
3260 static int __init
setup_fail_page_alloc(char *str
)
3262 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
3264 __setup("fail_page_alloc=", setup_fail_page_alloc
);
3266 static bool __should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
3268 if (order
< fail_page_alloc
.min_order
)
3270 if (gfp_mask
& __GFP_NOFAIL
)
3272 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
3274 if (fail_page_alloc
.ignore_gfp_reclaim
&&
3275 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
3278 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
3281 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
3283 static int __init
fail_page_alloc_debugfs(void)
3285 umode_t mode
= S_IFREG
| 0600;
3288 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
3289 &fail_page_alloc
.attr
);
3291 debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
3292 &fail_page_alloc
.ignore_gfp_reclaim
);
3293 debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
3294 &fail_page_alloc
.ignore_gfp_highmem
);
3295 debugfs_create_u32("min-order", mode
, dir
, &fail_page_alloc
.min_order
);
3300 late_initcall(fail_page_alloc_debugfs
);
3302 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
3304 #else /* CONFIG_FAIL_PAGE_ALLOC */
3306 static inline bool __should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
3311 #endif /* CONFIG_FAIL_PAGE_ALLOC */
3313 static noinline
bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
3315 return __should_fail_alloc_page(gfp_mask
, order
);
3317 ALLOW_ERROR_INJECTION(should_fail_alloc_page
, TRUE
);
3320 * Return true if free base pages are above 'mark'. For high-order checks it
3321 * will return true of the order-0 watermark is reached and there is at least
3322 * one free page of a suitable size. Checking now avoids taking the zone lock
3323 * to check in the allocation paths if no pages are free.
3325 bool __zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
3326 int classzone_idx
, unsigned int alloc_flags
,
3331 const bool alloc_harder
= (alloc_flags
& (ALLOC_HARDER
|ALLOC_OOM
));
3333 /* free_pages may go negative - that's OK */
3334 free_pages
-= (1 << order
) - 1;
3336 if (alloc_flags
& ALLOC_HIGH
)
3340 * If the caller does not have rights to ALLOC_HARDER then subtract
3341 * the high-atomic reserves. This will over-estimate the size of the
3342 * atomic reserve but it avoids a search.
3344 if (likely(!alloc_harder
)) {
3345 free_pages
-= z
->nr_reserved_highatomic
;
3348 * OOM victims can try even harder than normal ALLOC_HARDER
3349 * users on the grounds that it's definitely going to be in
3350 * the exit path shortly and free memory. Any allocation it
3351 * makes during the free path will be small and short-lived.
3353 if (alloc_flags
& ALLOC_OOM
)
3361 /* If allocation can't use CMA areas don't use free CMA pages */
3362 if (!(alloc_flags
& ALLOC_CMA
))
3363 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
3367 * Check watermarks for an order-0 allocation request. If these
3368 * are not met, then a high-order request also cannot go ahead
3369 * even if a suitable page happened to be free.
3371 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
3374 /* If this is an order-0 request then the watermark is fine */
3378 /* For a high-order request, check at least one suitable page is free */
3379 for (o
= order
; o
< MAX_ORDER
; o
++) {
3380 struct free_area
*area
= &z
->free_area
[o
];
3386 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
3387 if (!free_area_empty(area
, mt
))
3392 if ((alloc_flags
& ALLOC_CMA
) &&
3393 !free_area_empty(area
, MIGRATE_CMA
)) {
3398 !list_empty(&area
->free_list
[MIGRATE_HIGHATOMIC
]))
3404 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
3405 int classzone_idx
, unsigned int alloc_flags
)
3407 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
3408 zone_page_state(z
, NR_FREE_PAGES
));
3411 static inline bool zone_watermark_fast(struct zone
*z
, unsigned int order
,
3412 unsigned long mark
, int classzone_idx
, unsigned int alloc_flags
)
3414 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
3418 /* If allocation can't use CMA areas don't use free CMA pages */
3419 if (!(alloc_flags
& ALLOC_CMA
))
3420 cma_pages
= zone_page_state(z
, NR_FREE_CMA_PAGES
);
3424 * Fast check for order-0 only. If this fails then the reserves
3425 * need to be calculated. There is a corner case where the check
3426 * passes but only the high-order atomic reserve are free. If
3427 * the caller is !atomic then it'll uselessly search the free
3428 * list. That corner case is then slower but it is harmless.
3430 if (!order
&& (free_pages
- cma_pages
) > mark
+ z
->lowmem_reserve
[classzone_idx
])
3433 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
3437 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
3438 unsigned long mark
, int classzone_idx
)
3440 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
3442 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
3443 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
3445 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, 0,
3450 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
3452 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <=
3455 #else /* CONFIG_NUMA */
3456 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
3460 #endif /* CONFIG_NUMA */
3463 * The restriction on ZONE_DMA32 as being a suitable zone to use to avoid
3464 * fragmentation is subtle. If the preferred zone was HIGHMEM then
3465 * premature use of a lower zone may cause lowmem pressure problems that
3466 * are worse than fragmentation. If the next zone is ZONE_DMA then it is
3467 * probably too small. It only makes sense to spread allocations to avoid
3468 * fragmentation between the Normal and DMA32 zones.
3470 static inline unsigned int
3471 alloc_flags_nofragment(struct zone
*zone
, gfp_t gfp_mask
)
3473 unsigned int alloc_flags
= 0;
3475 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3476 alloc_flags
|= ALLOC_KSWAPD
;
3478 #ifdef CONFIG_ZONE_DMA32
3482 if (zone_idx(zone
) != ZONE_NORMAL
)
3486 * If ZONE_DMA32 exists, assume it is the one after ZONE_NORMAL and
3487 * the pointer is within zone->zone_pgdat->node_zones[]. Also assume
3488 * on UMA that if Normal is populated then so is DMA32.
3490 BUILD_BUG_ON(ZONE_NORMAL
- ZONE_DMA32
!= 1);
3491 if (nr_online_nodes
> 1 && !populated_zone(--zone
))
3494 alloc_flags
|= ALLOC_NOFRAGMENT
;
3495 #endif /* CONFIG_ZONE_DMA32 */
3500 * get_page_from_freelist goes through the zonelist trying to allocate
3503 static struct page
*
3504 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
3505 const struct alloc_context
*ac
)
3509 struct pglist_data
*last_pgdat_dirty_limit
= NULL
;
3514 * Scan zonelist, looking for a zone with enough free.
3515 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
3517 no_fallback
= alloc_flags
& ALLOC_NOFRAGMENT
;
3518 z
= ac
->preferred_zoneref
;
3519 for_next_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3524 if (cpusets_enabled() &&
3525 (alloc_flags
& ALLOC_CPUSET
) &&
3526 !__cpuset_zone_allowed(zone
, gfp_mask
))
3529 * When allocating a page cache page for writing, we
3530 * want to get it from a node that is within its dirty
3531 * limit, such that no single node holds more than its
3532 * proportional share of globally allowed dirty pages.
3533 * The dirty limits take into account the node's
3534 * lowmem reserves and high watermark so that kswapd
3535 * should be able to balance it without having to
3536 * write pages from its LRU list.
3538 * XXX: For now, allow allocations to potentially
3539 * exceed the per-node dirty limit in the slowpath
3540 * (spread_dirty_pages unset) before going into reclaim,
3541 * which is important when on a NUMA setup the allowed
3542 * nodes are together not big enough to reach the
3543 * global limit. The proper fix for these situations
3544 * will require awareness of nodes in the
3545 * dirty-throttling and the flusher threads.
3547 if (ac
->spread_dirty_pages
) {
3548 if (last_pgdat_dirty_limit
== zone
->zone_pgdat
)
3551 if (!node_dirty_ok(zone
->zone_pgdat
)) {
3552 last_pgdat_dirty_limit
= zone
->zone_pgdat
;
3557 if (no_fallback
&& nr_online_nodes
> 1 &&
3558 zone
!= ac
->preferred_zoneref
->zone
) {
3562 * If moving to a remote node, retry but allow
3563 * fragmenting fallbacks. Locality is more important
3564 * than fragmentation avoidance.
3566 local_nid
= zone_to_nid(ac
->preferred_zoneref
->zone
);
3567 if (zone_to_nid(zone
) != local_nid
) {
3568 alloc_flags
&= ~ALLOC_NOFRAGMENT
;
3573 mark
= wmark_pages(zone
, alloc_flags
& ALLOC_WMARK_MASK
);
3574 if (!zone_watermark_fast(zone
, order
, mark
,
3575 ac_classzone_idx(ac
), alloc_flags
)) {
3578 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
3580 * Watermark failed for this zone, but see if we can
3581 * grow this zone if it contains deferred pages.
3583 if (static_branch_unlikely(&deferred_pages
)) {
3584 if (_deferred_grow_zone(zone
, order
))
3588 /* Checked here to keep the fast path fast */
3589 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
3590 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
3593 if (node_reclaim_mode
== 0 ||
3594 !zone_allows_reclaim(ac
->preferred_zoneref
->zone
, zone
))
3597 ret
= node_reclaim(zone
->zone_pgdat
, gfp_mask
, order
);
3599 case NODE_RECLAIM_NOSCAN
:
3602 case NODE_RECLAIM_FULL
:
3603 /* scanned but unreclaimable */
3606 /* did we reclaim enough */
3607 if (zone_watermark_ok(zone
, order
, mark
,
3608 ac_classzone_idx(ac
), alloc_flags
))
3616 page
= rmqueue(ac
->preferred_zoneref
->zone
, zone
, order
,
3617 gfp_mask
, alloc_flags
, ac
->migratetype
);
3619 prep_new_page(page
, order
, gfp_mask
, alloc_flags
);
3622 * If this is a high-order atomic allocation then check
3623 * if the pageblock should be reserved for the future
3625 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
3626 reserve_highatomic_pageblock(page
, zone
, order
);
3630 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
3631 /* Try again if zone has deferred pages */
3632 if (static_branch_unlikely(&deferred_pages
)) {
3633 if (_deferred_grow_zone(zone
, order
))
3641 * It's possible on a UMA machine to get through all zones that are
3642 * fragmented. If avoiding fragmentation, reset and try again.
3645 alloc_flags
&= ~ALLOC_NOFRAGMENT
;
3652 static void warn_alloc_show_mem(gfp_t gfp_mask
, nodemask_t
*nodemask
)
3654 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
3655 static DEFINE_RATELIMIT_STATE(show_mem_rs
, HZ
, 1);
3657 if (!__ratelimit(&show_mem_rs
))
3661 * This documents exceptions given to allocations in certain
3662 * contexts that are allowed to allocate outside current's set
3665 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3666 if (tsk_is_oom_victim(current
) ||
3667 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
3668 filter
&= ~SHOW_MEM_FILTER_NODES
;
3669 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
3670 filter
&= ~SHOW_MEM_FILTER_NODES
;
3672 show_mem(filter
, nodemask
);
3675 void warn_alloc(gfp_t gfp_mask
, nodemask_t
*nodemask
, const char *fmt
, ...)
3677 struct va_format vaf
;
3679 static DEFINE_RATELIMIT_STATE(nopage_rs
, DEFAULT_RATELIMIT_INTERVAL
,
3680 DEFAULT_RATELIMIT_BURST
);
3682 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
))
3685 va_start(args
, fmt
);
3688 pr_warn("%s: %pV, mode:%#x(%pGg), nodemask=%*pbl",
3689 current
->comm
, &vaf
, gfp_mask
, &gfp_mask
,
3690 nodemask_pr_args(nodemask
));
3693 cpuset_print_current_mems_allowed();
3696 warn_alloc_show_mem(gfp_mask
, nodemask
);
3699 static inline struct page
*
3700 __alloc_pages_cpuset_fallback(gfp_t gfp_mask
, unsigned int order
,
3701 unsigned int alloc_flags
,
3702 const struct alloc_context
*ac
)
3706 page
= get_page_from_freelist(gfp_mask
, order
,
3707 alloc_flags
|ALLOC_CPUSET
, ac
);
3709 * fallback to ignore cpuset restriction if our nodes
3713 page
= get_page_from_freelist(gfp_mask
, order
,
3719 static inline struct page
*
3720 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
3721 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
3723 struct oom_control oc
= {
3724 .zonelist
= ac
->zonelist
,
3725 .nodemask
= ac
->nodemask
,
3727 .gfp_mask
= gfp_mask
,
3732 *did_some_progress
= 0;
3735 * Acquire the oom lock. If that fails, somebody else is
3736 * making progress for us.
3738 if (!mutex_trylock(&oom_lock
)) {
3739 *did_some_progress
= 1;
3740 schedule_timeout_uninterruptible(1);
3745 * Go through the zonelist yet one more time, keep very high watermark
3746 * here, this is only to catch a parallel oom killing, we must fail if
3747 * we're still under heavy pressure. But make sure that this reclaim
3748 * attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY
3749 * allocation which will never fail due to oom_lock already held.
3751 page
= get_page_from_freelist((gfp_mask
| __GFP_HARDWALL
) &
3752 ~__GFP_DIRECT_RECLAIM
, order
,
3753 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
3757 /* Coredumps can quickly deplete all memory reserves */
3758 if (current
->flags
& PF_DUMPCORE
)
3760 /* The OOM killer will not help higher order allocs */
3761 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3764 * We have already exhausted all our reclaim opportunities without any
3765 * success so it is time to admit defeat. We will skip the OOM killer
3766 * because it is very likely that the caller has a more reasonable
3767 * fallback than shooting a random task.
3769 if (gfp_mask
& __GFP_RETRY_MAYFAIL
)
3771 /* The OOM killer does not needlessly kill tasks for lowmem */
3772 if (ac
->high_zoneidx
< ZONE_NORMAL
)
3774 if (pm_suspended_storage())
3777 * XXX: GFP_NOFS allocations should rather fail than rely on
3778 * other request to make a forward progress.
3779 * We are in an unfortunate situation where out_of_memory cannot
3780 * do much for this context but let's try it to at least get
3781 * access to memory reserved if the current task is killed (see
3782 * out_of_memory). Once filesystems are ready to handle allocation
3783 * failures more gracefully we should just bail out here.
3786 /* The OOM killer may not free memory on a specific node */
3787 if (gfp_mask
& __GFP_THISNODE
)
3790 /* Exhausted what can be done so it's blame time */
3791 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3792 *did_some_progress
= 1;
3795 * Help non-failing allocations by giving them access to memory
3798 if (gfp_mask
& __GFP_NOFAIL
)
3799 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
,
3800 ALLOC_NO_WATERMARKS
, ac
);
3803 mutex_unlock(&oom_lock
);
3808 * Maximum number of compaction retries wit a progress before OOM
3809 * killer is consider as the only way to move forward.
3811 #define MAX_COMPACT_RETRIES 16
3813 #ifdef CONFIG_COMPACTION
3814 /* Try memory compaction for high-order allocations before reclaim */
3815 static struct page
*
3816 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3817 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3818 enum compact_priority prio
, enum compact_result
*compact_result
)
3820 struct page
*page
= NULL
;
3821 unsigned long pflags
;
3822 unsigned int noreclaim_flag
;
3827 psi_memstall_enter(&pflags
);
3828 noreclaim_flag
= memalloc_noreclaim_save();
3830 *compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
3833 memalloc_noreclaim_restore(noreclaim_flag
);
3834 psi_memstall_leave(&pflags
);
3837 * At least in one zone compaction wasn't deferred or skipped, so let's
3838 * count a compaction stall
3840 count_vm_event(COMPACTSTALL
);
3842 /* Prep a captured page if available */
3844 prep_new_page(page
, order
, gfp_mask
, alloc_flags
);
3846 /* Try get a page from the freelist if available */
3848 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
3851 struct zone
*zone
= page_zone(page
);
3853 zone
->compact_blockskip_flush
= false;
3854 compaction_defer_reset(zone
, order
, true);
3855 count_vm_event(COMPACTSUCCESS
);
3860 * It's bad if compaction run occurs and fails. The most likely reason
3861 * is that pages exist, but not enough to satisfy watermarks.
3863 count_vm_event(COMPACTFAIL
);
3871 should_compact_retry(struct alloc_context
*ac
, int order
, int alloc_flags
,
3872 enum compact_result compact_result
,
3873 enum compact_priority
*compact_priority
,
3874 int *compaction_retries
)
3876 int max_retries
= MAX_COMPACT_RETRIES
;
3879 int retries
= *compaction_retries
;
3880 enum compact_priority priority
= *compact_priority
;
3885 if (compaction_made_progress(compact_result
))
3886 (*compaction_retries
)++;
3889 * compaction considers all the zone as desperately out of memory
3890 * so it doesn't really make much sense to retry except when the
3891 * failure could be caused by insufficient priority
3893 if (compaction_failed(compact_result
))
3894 goto check_priority
;
3897 * make sure the compaction wasn't deferred or didn't bail out early
3898 * due to locks contention before we declare that we should give up.
3899 * But do not retry if the given zonelist is not suitable for
3902 if (compaction_withdrawn(compact_result
)) {
3903 ret
= compaction_zonelist_suitable(ac
, order
, alloc_flags
);
3908 * !costly requests are much more important than __GFP_RETRY_MAYFAIL
3909 * costly ones because they are de facto nofail and invoke OOM
3910 * killer to move on while costly can fail and users are ready
3911 * to cope with that. 1/4 retries is rather arbitrary but we
3912 * would need much more detailed feedback from compaction to
3913 * make a better decision.
3915 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
3917 if (*compaction_retries
<= max_retries
) {
3923 * Make sure there are attempts at the highest priority if we exhausted
3924 * all retries or failed at the lower priorities.
3927 min_priority
= (order
> PAGE_ALLOC_COSTLY_ORDER
) ?
3928 MIN_COMPACT_COSTLY_PRIORITY
: MIN_COMPACT_PRIORITY
;
3930 if (*compact_priority
> min_priority
) {
3931 (*compact_priority
)--;
3932 *compaction_retries
= 0;
3936 trace_compact_retry(order
, priority
, compact_result
, retries
, max_retries
, ret
);
3940 static inline struct page
*
3941 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
3942 unsigned int alloc_flags
, const struct alloc_context
*ac
,
3943 enum compact_priority prio
, enum compact_result
*compact_result
)
3945 *compact_result
= COMPACT_SKIPPED
;
3950 should_compact_retry(struct alloc_context
*ac
, unsigned int order
, int alloc_flags
,
3951 enum compact_result compact_result
,
3952 enum compact_priority
*compact_priority
,
3953 int *compaction_retries
)
3958 if (!order
|| order
> PAGE_ALLOC_COSTLY_ORDER
)
3962 * There are setups with compaction disabled which would prefer to loop
3963 * inside the allocator rather than hit the oom killer prematurely.
3964 * Let's give them a good hope and keep retrying while the order-0
3965 * watermarks are OK.
3967 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
3969 if (zone_watermark_ok(zone
, 0, min_wmark_pages(zone
),
3970 ac_classzone_idx(ac
), alloc_flags
))
3975 #endif /* CONFIG_COMPACTION */
3977 #ifdef CONFIG_LOCKDEP
3978 static struct lockdep_map __fs_reclaim_map
=
3979 STATIC_LOCKDEP_MAP_INIT("fs_reclaim", &__fs_reclaim_map
);
3981 static bool __need_fs_reclaim(gfp_t gfp_mask
)
3983 gfp_mask
= current_gfp_context(gfp_mask
);
3985 /* no reclaim without waiting on it */
3986 if (!(gfp_mask
& __GFP_DIRECT_RECLAIM
))
3989 /* this guy won't enter reclaim */
3990 if (current
->flags
& PF_MEMALLOC
)
3993 /* We're only interested __GFP_FS allocations for now */
3994 if (!(gfp_mask
& __GFP_FS
))
3997 if (gfp_mask
& __GFP_NOLOCKDEP
)
4003 void __fs_reclaim_acquire(void)
4005 lock_map_acquire(&__fs_reclaim_map
);
4008 void __fs_reclaim_release(void)
4010 lock_map_release(&__fs_reclaim_map
);
4013 void fs_reclaim_acquire(gfp_t gfp_mask
)
4015 if (__need_fs_reclaim(gfp_mask
))
4016 __fs_reclaim_acquire();
4018 EXPORT_SYMBOL_GPL(fs_reclaim_acquire
);
4020 void fs_reclaim_release(gfp_t gfp_mask
)
4022 if (__need_fs_reclaim(gfp_mask
))
4023 __fs_reclaim_release();
4025 EXPORT_SYMBOL_GPL(fs_reclaim_release
);
4028 /* Perform direct synchronous page reclaim */
4030 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
4031 const struct alloc_context
*ac
)
4033 struct reclaim_state reclaim_state
;
4035 unsigned int noreclaim_flag
;
4036 unsigned long pflags
;
4040 /* We now go into synchronous reclaim */
4041 cpuset_memory_pressure_bump();
4042 psi_memstall_enter(&pflags
);
4043 fs_reclaim_acquire(gfp_mask
);
4044 noreclaim_flag
= memalloc_noreclaim_save();
4045 reclaim_state
.reclaimed_slab
= 0;
4046 current
->reclaim_state
= &reclaim_state
;
4048 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
4051 current
->reclaim_state
= NULL
;
4052 memalloc_noreclaim_restore(noreclaim_flag
);
4053 fs_reclaim_release(gfp_mask
);
4054 psi_memstall_leave(&pflags
);
4061 /* The really slow allocator path where we enter direct reclaim */
4062 static inline struct page
*
4063 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
4064 unsigned int alloc_flags
, const struct alloc_context
*ac
,
4065 unsigned long *did_some_progress
)
4067 struct page
*page
= NULL
;
4068 bool drained
= false;
4070 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
4071 if (unlikely(!(*did_some_progress
)))
4075 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
4078 * If an allocation failed after direct reclaim, it could be because
4079 * pages are pinned on the per-cpu lists or in high alloc reserves.
4080 * Shrink them them and try again
4082 if (!page
&& !drained
) {
4083 unreserve_highatomic_pageblock(ac
, false);
4084 drain_all_pages(NULL
);
4092 static void wake_all_kswapds(unsigned int order
, gfp_t gfp_mask
,
4093 const struct alloc_context
*ac
)
4097 pg_data_t
*last_pgdat
= NULL
;
4098 enum zone_type high_zoneidx
= ac
->high_zoneidx
;
4100 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, high_zoneidx
,
4102 if (last_pgdat
!= zone
->zone_pgdat
)
4103 wakeup_kswapd(zone
, gfp_mask
, order
, high_zoneidx
);
4104 last_pgdat
= zone
->zone_pgdat
;
4108 static inline unsigned int
4109 gfp_to_alloc_flags(gfp_t gfp_mask
)
4111 unsigned int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
4113 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
4114 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
4117 * The caller may dip into page reserves a bit more if the caller
4118 * cannot run direct reclaim, or if the caller has realtime scheduling
4119 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
4120 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
4122 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
4124 if (gfp_mask
& __GFP_ATOMIC
) {
4126 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
4127 * if it can't schedule.
4129 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
4130 alloc_flags
|= ALLOC_HARDER
;
4132 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
4133 * comment for __cpuset_node_allowed().
4135 alloc_flags
&= ~ALLOC_CPUSET
;
4136 } else if (unlikely(rt_task(current
)) && !in_interrupt())
4137 alloc_flags
|= ALLOC_HARDER
;
4139 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
4140 alloc_flags
|= ALLOC_KSWAPD
;
4143 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
4144 alloc_flags
|= ALLOC_CMA
;
4149 static bool oom_reserves_allowed(struct task_struct
*tsk
)
4151 if (!tsk_is_oom_victim(tsk
))
4155 * !MMU doesn't have oom reaper so give access to memory reserves
4156 * only to the thread with TIF_MEMDIE set
4158 if (!IS_ENABLED(CONFIG_MMU
) && !test_thread_flag(TIF_MEMDIE
))
4165 * Distinguish requests which really need access to full memory
4166 * reserves from oom victims which can live with a portion of it
4168 static inline int __gfp_pfmemalloc_flags(gfp_t gfp_mask
)
4170 if (unlikely(gfp_mask
& __GFP_NOMEMALLOC
))
4172 if (gfp_mask
& __GFP_MEMALLOC
)
4173 return ALLOC_NO_WATERMARKS
;
4174 if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
4175 return ALLOC_NO_WATERMARKS
;
4176 if (!in_interrupt()) {
4177 if (current
->flags
& PF_MEMALLOC
)
4178 return ALLOC_NO_WATERMARKS
;
4179 else if (oom_reserves_allowed(current
))
4186 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
4188 return !!__gfp_pfmemalloc_flags(gfp_mask
);
4192 * Checks whether it makes sense to retry the reclaim to make a forward progress
4193 * for the given allocation request.
4195 * We give up when we either have tried MAX_RECLAIM_RETRIES in a row
4196 * without success, or when we couldn't even meet the watermark if we
4197 * reclaimed all remaining pages on the LRU lists.
4199 * Returns true if a retry is viable or false to enter the oom path.
4202 should_reclaim_retry(gfp_t gfp_mask
, unsigned order
,
4203 struct alloc_context
*ac
, int alloc_flags
,
4204 bool did_some_progress
, int *no_progress_loops
)
4211 * Costly allocations might have made a progress but this doesn't mean
4212 * their order will become available due to high fragmentation so
4213 * always increment the no progress counter for them
4215 if (did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
)
4216 *no_progress_loops
= 0;
4218 (*no_progress_loops
)++;
4221 * Make sure we converge to OOM if we cannot make any progress
4222 * several times in the row.
4224 if (*no_progress_loops
> MAX_RECLAIM_RETRIES
) {
4225 /* Before OOM, exhaust highatomic_reserve */
4226 return unreserve_highatomic_pageblock(ac
, true);
4230 * Keep reclaiming pages while there is a chance this will lead
4231 * somewhere. If none of the target zones can satisfy our allocation
4232 * request even if all reclaimable pages are considered then we are
4233 * screwed and have to go OOM.
4235 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
, ac
->high_zoneidx
,
4237 unsigned long available
;
4238 unsigned long reclaimable
;
4239 unsigned long min_wmark
= min_wmark_pages(zone
);
4242 available
= reclaimable
= zone_reclaimable_pages(zone
);
4243 available
+= zone_page_state_snapshot(zone
, NR_FREE_PAGES
);
4246 * Would the allocation succeed if we reclaimed all
4247 * reclaimable pages?
4249 wmark
= __zone_watermark_ok(zone
, order
, min_wmark
,
4250 ac_classzone_idx(ac
), alloc_flags
, available
);
4251 trace_reclaim_retry_zone(z
, order
, reclaimable
,
4252 available
, min_wmark
, *no_progress_loops
, wmark
);
4255 * If we didn't make any progress and have a lot of
4256 * dirty + writeback pages then we should wait for
4257 * an IO to complete to slow down the reclaim and
4258 * prevent from pre mature OOM
4260 if (!did_some_progress
) {
4261 unsigned long write_pending
;
4263 write_pending
= zone_page_state_snapshot(zone
,
4264 NR_ZONE_WRITE_PENDING
);
4266 if (2 * write_pending
> reclaimable
) {
4267 congestion_wait(BLK_RW_ASYNC
, HZ
/10);
4279 * Memory allocation/reclaim might be called from a WQ context and the
4280 * current implementation of the WQ concurrency control doesn't
4281 * recognize that a particular WQ is congested if the worker thread is
4282 * looping without ever sleeping. Therefore we have to do a short sleep
4283 * here rather than calling cond_resched().
4285 if (current
->flags
& PF_WQ_WORKER
)
4286 schedule_timeout_uninterruptible(1);
4293 check_retry_cpuset(int cpuset_mems_cookie
, struct alloc_context
*ac
)
4296 * It's possible that cpuset's mems_allowed and the nodemask from
4297 * mempolicy don't intersect. This should be normally dealt with by
4298 * policy_nodemask(), but it's possible to race with cpuset update in
4299 * such a way the check therein was true, and then it became false
4300 * before we got our cpuset_mems_cookie here.
4301 * This assumes that for all allocations, ac->nodemask can come only
4302 * from MPOL_BIND mempolicy (whose documented semantics is to be ignored
4303 * when it does not intersect with the cpuset restrictions) or the
4304 * caller can deal with a violated nodemask.
4306 if (cpusets_enabled() && ac
->nodemask
&&
4307 !cpuset_nodemask_valid_mems_allowed(ac
->nodemask
)) {
4308 ac
->nodemask
= NULL
;
4313 * When updating a task's mems_allowed or mempolicy nodemask, it is
4314 * possible to race with parallel threads in such a way that our
4315 * allocation can fail while the mask is being updated. If we are about
4316 * to fail, check if the cpuset changed during allocation and if so,
4319 if (read_mems_allowed_retry(cpuset_mems_cookie
))
4325 static inline struct page
*
4326 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
4327 struct alloc_context
*ac
)
4329 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
4330 const bool costly_order
= order
> PAGE_ALLOC_COSTLY_ORDER
;
4331 struct page
*page
= NULL
;
4332 unsigned int alloc_flags
;
4333 unsigned long did_some_progress
;
4334 enum compact_priority compact_priority
;
4335 enum compact_result compact_result
;
4336 int compaction_retries
;
4337 int no_progress_loops
;
4338 unsigned int cpuset_mems_cookie
;
4342 * We also sanity check to catch abuse of atomic reserves being used by
4343 * callers that are not in atomic context.
4345 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
4346 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
4347 gfp_mask
&= ~__GFP_ATOMIC
;
4350 compaction_retries
= 0;
4351 no_progress_loops
= 0;
4352 compact_priority
= DEF_COMPACT_PRIORITY
;
4353 cpuset_mems_cookie
= read_mems_allowed_begin();
4356 * The fast path uses conservative alloc_flags to succeed only until
4357 * kswapd needs to be woken up, and to avoid the cost of setting up
4358 * alloc_flags precisely. So we do that now.
4360 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
4363 * We need to recalculate the starting point for the zonelist iterator
4364 * because we might have used different nodemask in the fast path, or
4365 * there was a cpuset modification and we are retrying - otherwise we
4366 * could end up iterating over non-eligible zones endlessly.
4368 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
4369 ac
->high_zoneidx
, ac
->nodemask
);
4370 if (!ac
->preferred_zoneref
->zone
)
4373 if (alloc_flags
& ALLOC_KSWAPD
)
4374 wake_all_kswapds(order
, gfp_mask
, ac
);
4377 * The adjusted alloc_flags might result in immediate success, so try
4380 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
4385 * For costly allocations, try direct compaction first, as it's likely
4386 * that we have enough base pages and don't need to reclaim. For non-
4387 * movable high-order allocations, do that as well, as compaction will
4388 * try prevent permanent fragmentation by migrating from blocks of the
4390 * Don't try this for allocations that are allowed to ignore
4391 * watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen.
4393 if (can_direct_reclaim
&&
4395 (order
> 0 && ac
->migratetype
!= MIGRATE_MOVABLE
))
4396 && !gfp_pfmemalloc_allowed(gfp_mask
)) {
4397 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
4399 INIT_COMPACT_PRIORITY
,
4405 * Checks for costly allocations with __GFP_NORETRY, which
4406 * includes THP page fault allocations
4408 if (costly_order
&& (gfp_mask
& __GFP_NORETRY
)) {
4410 * If compaction is deferred for high-order allocations,
4411 * it is because sync compaction recently failed. If
4412 * this is the case and the caller requested a THP
4413 * allocation, we do not want to heavily disrupt the
4414 * system, so we fail the allocation instead of entering
4417 if (compact_result
== COMPACT_DEFERRED
)
4421 * Looks like reclaim/compaction is worth trying, but
4422 * sync compaction could be very expensive, so keep
4423 * using async compaction.
4425 compact_priority
= INIT_COMPACT_PRIORITY
;
4430 /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */
4431 if (alloc_flags
& ALLOC_KSWAPD
)
4432 wake_all_kswapds(order
, gfp_mask
, ac
);
4434 reserve_flags
= __gfp_pfmemalloc_flags(gfp_mask
);
4436 alloc_flags
= reserve_flags
;
4439 * Reset the nodemask and zonelist iterators if memory policies can be
4440 * ignored. These allocations are high priority and system rather than
4443 if (!(alloc_flags
& ALLOC_CPUSET
) || reserve_flags
) {
4444 ac
->nodemask
= NULL
;
4445 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
4446 ac
->high_zoneidx
, ac
->nodemask
);
4449 /* Attempt with potentially adjusted zonelist and alloc_flags */
4450 page
= get_page_from_freelist(gfp_mask
, order
, alloc_flags
, ac
);
4454 /* Caller is not willing to reclaim, we can't balance anything */
4455 if (!can_direct_reclaim
)
4458 /* Avoid recursion of direct reclaim */
4459 if (current
->flags
& PF_MEMALLOC
)
4462 /* Try direct reclaim and then allocating */
4463 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
4464 &did_some_progress
);
4468 /* Try direct compaction and then allocating */
4469 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
4470 compact_priority
, &compact_result
);
4474 /* Do not loop if specifically requested */
4475 if (gfp_mask
& __GFP_NORETRY
)
4479 * Do not retry costly high order allocations unless they are
4480 * __GFP_RETRY_MAYFAIL
4482 if (costly_order
&& !(gfp_mask
& __GFP_RETRY_MAYFAIL
))
4485 if (should_reclaim_retry(gfp_mask
, order
, ac
, alloc_flags
,
4486 did_some_progress
> 0, &no_progress_loops
))
4490 * It doesn't make any sense to retry for the compaction if the order-0
4491 * reclaim is not able to make any progress because the current
4492 * implementation of the compaction depends on the sufficient amount
4493 * of free memory (see __compaction_suitable)
4495 if (did_some_progress
> 0 &&
4496 should_compact_retry(ac
, order
, alloc_flags
,
4497 compact_result
, &compact_priority
,
4498 &compaction_retries
))
4502 /* Deal with possible cpuset update races before we start OOM killing */
4503 if (check_retry_cpuset(cpuset_mems_cookie
, ac
))
4506 /* Reclaim has failed us, start killing things */
4507 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
4511 /* Avoid allocations with no watermarks from looping endlessly */
4512 if (tsk_is_oom_victim(current
) &&
4513 (alloc_flags
== ALLOC_OOM
||
4514 (gfp_mask
& __GFP_NOMEMALLOC
)))
4517 /* Retry as long as the OOM killer is making progress */
4518 if (did_some_progress
) {
4519 no_progress_loops
= 0;
4524 /* Deal with possible cpuset update races before we fail */
4525 if (check_retry_cpuset(cpuset_mems_cookie
, ac
))
4529 * Make sure that __GFP_NOFAIL request doesn't leak out and make sure
4532 if (gfp_mask
& __GFP_NOFAIL
) {
4534 * All existing users of the __GFP_NOFAIL are blockable, so warn
4535 * of any new users that actually require GFP_NOWAIT
4537 if (WARN_ON_ONCE(!can_direct_reclaim
))
4541 * PF_MEMALLOC request from this context is rather bizarre
4542 * because we cannot reclaim anything and only can loop waiting
4543 * for somebody to do a work for us
4545 WARN_ON_ONCE(current
->flags
& PF_MEMALLOC
);
4548 * non failing costly orders are a hard requirement which we
4549 * are not prepared for much so let's warn about these users
4550 * so that we can identify them and convert them to something
4553 WARN_ON_ONCE(order
> PAGE_ALLOC_COSTLY_ORDER
);
4556 * Help non-failing allocations by giving them access to memory
4557 * reserves but do not use ALLOC_NO_WATERMARKS because this
4558 * could deplete whole memory reserves which would just make
4559 * the situation worse
4561 page
= __alloc_pages_cpuset_fallback(gfp_mask
, order
, ALLOC_HARDER
, ac
);
4569 warn_alloc(gfp_mask
, ac
->nodemask
,
4570 "page allocation failure: order:%u", order
);
4575 static inline bool prepare_alloc_pages(gfp_t gfp_mask
, unsigned int order
,
4576 int preferred_nid
, nodemask_t
*nodemask
,
4577 struct alloc_context
*ac
, gfp_t
*alloc_mask
,
4578 unsigned int *alloc_flags
)
4580 ac
->high_zoneidx
= gfp_zone(gfp_mask
);
4581 ac
->zonelist
= node_zonelist(preferred_nid
, gfp_mask
);
4582 ac
->nodemask
= nodemask
;
4583 ac
->migratetype
= gfpflags_to_migratetype(gfp_mask
);
4585 if (cpusets_enabled()) {
4586 *alloc_mask
|= __GFP_HARDWALL
;
4588 ac
->nodemask
= &cpuset_current_mems_allowed
;
4590 *alloc_flags
|= ALLOC_CPUSET
;
4593 fs_reclaim_acquire(gfp_mask
);
4594 fs_reclaim_release(gfp_mask
);
4596 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
4598 if (should_fail_alloc_page(gfp_mask
, order
))
4601 if (IS_ENABLED(CONFIG_CMA
) && ac
->migratetype
== MIGRATE_MOVABLE
)
4602 *alloc_flags
|= ALLOC_CMA
;
4607 /* Determine whether to spread dirty pages and what the first usable zone */
4608 static inline void finalise_ac(gfp_t gfp_mask
, struct alloc_context
*ac
)
4610 /* Dirty zone balancing only done in the fast path */
4611 ac
->spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
4614 * The preferred zone is used for statistics but crucially it is
4615 * also used as the starting point for the zonelist iterator. It
4616 * may get reset for allocations that ignore memory policies.
4618 ac
->preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
4619 ac
->high_zoneidx
, ac
->nodemask
);
4623 * This is the 'heart' of the zoned buddy allocator.
4626 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
, int preferred_nid
,
4627 nodemask_t
*nodemask
)
4630 unsigned int alloc_flags
= ALLOC_WMARK_LOW
;
4631 gfp_t alloc_mask
; /* The gfp_t that was actually used for allocation */
4632 struct alloc_context ac
= { };
4635 * There are several places where we assume that the order value is sane
4636 * so bail out early if the request is out of bound.
4638 if (unlikely(order
>= MAX_ORDER
)) {
4639 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
4643 gfp_mask
&= gfp_allowed_mask
;
4644 alloc_mask
= gfp_mask
;
4645 if (!prepare_alloc_pages(gfp_mask
, order
, preferred_nid
, nodemask
, &ac
, &alloc_mask
, &alloc_flags
))
4648 finalise_ac(gfp_mask
, &ac
);
4651 * Forbid the first pass from falling back to types that fragment
4652 * memory until all local zones are considered.
4654 alloc_flags
|= alloc_flags_nofragment(ac
.preferred_zoneref
->zone
, gfp_mask
);
4656 /* First allocation attempt */
4657 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
4662 * Apply scoped allocation constraints. This is mainly about GFP_NOFS
4663 * resp. GFP_NOIO which has to be inherited for all allocation requests
4664 * from a particular context which has been marked by
4665 * memalloc_no{fs,io}_{save,restore}.
4667 alloc_mask
= current_gfp_context(gfp_mask
);
4668 ac
.spread_dirty_pages
= false;
4671 * Restore the original nodemask if it was potentially replaced with
4672 * &cpuset_current_mems_allowed to optimize the fast-path attempt.
4674 if (unlikely(ac
.nodemask
!= nodemask
))
4675 ac
.nodemask
= nodemask
;
4677 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
4680 if (memcg_kmem_enabled() && (gfp_mask
& __GFP_ACCOUNT
) && page
&&
4681 unlikely(__memcg_kmem_charge(page
, gfp_mask
, order
) != 0)) {
4682 __free_pages(page
, order
);
4686 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
4690 EXPORT_SYMBOL(__alloc_pages_nodemask
);
4693 * Common helper functions. Never use with __GFP_HIGHMEM because the returned
4694 * address cannot represent highmem pages. Use alloc_pages and then kmap if
4695 * you need to access high mem.
4697 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
4701 page
= alloc_pages(gfp_mask
& ~__GFP_HIGHMEM
, order
);
4704 return (unsigned long) page_address(page
);
4706 EXPORT_SYMBOL(__get_free_pages
);
4708 unsigned long get_zeroed_page(gfp_t gfp_mask
)
4710 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
4712 EXPORT_SYMBOL(get_zeroed_page
);
4714 static inline void free_the_page(struct page
*page
, unsigned int order
)
4716 if (order
== 0) /* Via pcp? */
4717 free_unref_page(page
);
4719 __free_pages_ok(page
, order
);
4722 void __free_pages(struct page
*page
, unsigned int order
)
4724 if (put_page_testzero(page
))
4725 free_the_page(page
, order
);
4727 EXPORT_SYMBOL(__free_pages
);
4729 void free_pages(unsigned long addr
, unsigned int order
)
4732 VM_BUG_ON(!virt_addr_valid((void *)addr
));
4733 __free_pages(virt_to_page((void *)addr
), order
);
4737 EXPORT_SYMBOL(free_pages
);
4741 * An arbitrary-length arbitrary-offset area of memory which resides
4742 * within a 0 or higher order page. Multiple fragments within that page
4743 * are individually refcounted, in the page's reference counter.
4745 * The page_frag functions below provide a simple allocation framework for
4746 * page fragments. This is used by the network stack and network device
4747 * drivers to provide a backing region of memory for use as either an
4748 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
4750 static struct page
*__page_frag_cache_refill(struct page_frag_cache
*nc
,
4753 struct page
*page
= NULL
;
4754 gfp_t gfp
= gfp_mask
;
4756 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4757 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
4759 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
4760 PAGE_FRAG_CACHE_MAX_ORDER
);
4761 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
4763 if (unlikely(!page
))
4764 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
4766 nc
->va
= page
? page_address(page
) : NULL
;
4771 void __page_frag_cache_drain(struct page
*page
, unsigned int count
)
4773 VM_BUG_ON_PAGE(page_ref_count(page
) == 0, page
);
4775 if (page_ref_sub_and_test(page
, count
))
4776 free_the_page(page
, compound_order(page
));
4778 EXPORT_SYMBOL(__page_frag_cache_drain
);
4780 void *page_frag_alloc(struct page_frag_cache
*nc
,
4781 unsigned int fragsz
, gfp_t gfp_mask
)
4783 unsigned int size
= PAGE_SIZE
;
4787 if (unlikely(!nc
->va
)) {
4789 page
= __page_frag_cache_refill(nc
, gfp_mask
);
4793 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4794 /* if size can vary use size else just use PAGE_SIZE */
4797 /* Even if we own the page, we do not use atomic_set().
4798 * This would break get_page_unless_zero() users.
4800 page_ref_add(page
, PAGE_FRAG_CACHE_MAX_SIZE
);
4802 /* reset page count bias and offset to start of new frag */
4803 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
4804 nc
->pagecnt_bias
= PAGE_FRAG_CACHE_MAX_SIZE
+ 1;
4808 offset
= nc
->offset
- fragsz
;
4809 if (unlikely(offset
< 0)) {
4810 page
= virt_to_page(nc
->va
);
4812 if (!page_ref_sub_and_test(page
, nc
->pagecnt_bias
))
4815 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
4816 /* if size can vary use size else just use PAGE_SIZE */
4819 /* OK, page count is 0, we can safely set it */
4820 set_page_count(page
, PAGE_FRAG_CACHE_MAX_SIZE
+ 1);
4822 /* reset page count bias and offset to start of new frag */
4823 nc
->pagecnt_bias
= PAGE_FRAG_CACHE_MAX_SIZE
+ 1;
4824 offset
= size
- fragsz
;
4828 nc
->offset
= offset
;
4830 return nc
->va
+ offset
;
4832 EXPORT_SYMBOL(page_frag_alloc
);
4835 * Frees a page fragment allocated out of either a compound or order 0 page.
4837 void page_frag_free(void *addr
)
4839 struct page
*page
= virt_to_head_page(addr
);
4841 if (unlikely(put_page_testzero(page
)))
4842 free_the_page(page
, compound_order(page
));
4844 EXPORT_SYMBOL(page_frag_free
);
4846 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
4850 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
4851 unsigned long used
= addr
+ PAGE_ALIGN(size
);
4853 split_page(virt_to_page((void *)addr
), order
);
4854 while (used
< alloc_end
) {
4859 return (void *)addr
;
4863 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
4864 * @size: the number of bytes to allocate
4865 * @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP
4867 * This function is similar to alloc_pages(), except that it allocates the
4868 * minimum number of pages to satisfy the request. alloc_pages() can only
4869 * allocate memory in power-of-two pages.
4871 * This function is also limited by MAX_ORDER.
4873 * Memory allocated by this function must be released by free_pages_exact().
4875 * Return: pointer to the allocated area or %NULL in case of error.
4877 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
4879 unsigned int order
= get_order(size
);
4882 if (WARN_ON_ONCE(gfp_mask
& __GFP_COMP
))
4883 gfp_mask
&= ~__GFP_COMP
;
4885 addr
= __get_free_pages(gfp_mask
, order
);
4886 return make_alloc_exact(addr
, order
, size
);
4888 EXPORT_SYMBOL(alloc_pages_exact
);
4891 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
4893 * @nid: the preferred node ID where memory should be allocated
4894 * @size: the number of bytes to allocate
4895 * @gfp_mask: GFP flags for the allocation, must not contain __GFP_COMP
4897 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
4900 * Return: pointer to the allocated area or %NULL in case of error.
4902 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
4904 unsigned int order
= get_order(size
);
4907 if (WARN_ON_ONCE(gfp_mask
& __GFP_COMP
))
4908 gfp_mask
&= ~__GFP_COMP
;
4910 p
= alloc_pages_node(nid
, gfp_mask
, order
);
4913 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
4917 * free_pages_exact - release memory allocated via alloc_pages_exact()
4918 * @virt: the value returned by alloc_pages_exact.
4919 * @size: size of allocation, same value as passed to alloc_pages_exact().
4921 * Release the memory allocated by a previous call to alloc_pages_exact.
4923 void free_pages_exact(void *virt
, size_t size
)
4925 unsigned long addr
= (unsigned long)virt
;
4926 unsigned long end
= addr
+ PAGE_ALIGN(size
);
4928 while (addr
< end
) {
4933 EXPORT_SYMBOL(free_pages_exact
);
4936 * nr_free_zone_pages - count number of pages beyond high watermark
4937 * @offset: The zone index of the highest zone
4939 * nr_free_zone_pages() counts the number of pages which are beyond the
4940 * high watermark within all zones at or below a given zone index. For each
4941 * zone, the number of pages is calculated as:
4943 * nr_free_zone_pages = managed_pages - high_pages
4945 * Return: number of pages beyond high watermark.
4947 static unsigned long nr_free_zone_pages(int offset
)
4952 /* Just pick one node, since fallback list is circular */
4953 unsigned long sum
= 0;
4955 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
4957 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
4958 unsigned long size
= zone_managed_pages(zone
);
4959 unsigned long high
= high_wmark_pages(zone
);
4968 * nr_free_buffer_pages - count number of pages beyond high watermark
4970 * nr_free_buffer_pages() counts the number of pages which are beyond the high
4971 * watermark within ZONE_DMA and ZONE_NORMAL.
4973 * Return: number of pages beyond high watermark within ZONE_DMA and
4976 unsigned long nr_free_buffer_pages(void)
4978 return nr_free_zone_pages(gfp_zone(GFP_USER
));
4980 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
4983 * nr_free_pagecache_pages - count number of pages beyond high watermark
4985 * nr_free_pagecache_pages() counts the number of pages which are beyond the
4986 * high watermark within all zones.
4988 * Return: number of pages beyond high watermark within all zones.
4990 unsigned long nr_free_pagecache_pages(void)
4992 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
4995 static inline void show_node(struct zone
*zone
)
4997 if (IS_ENABLED(CONFIG_NUMA
))
4998 printk("Node %d ", zone_to_nid(zone
));
5001 long si_mem_available(void)
5004 unsigned long pagecache
;
5005 unsigned long wmark_low
= 0;
5006 unsigned long pages
[NR_LRU_LISTS
];
5007 unsigned long reclaimable
;
5011 for (lru
= LRU_BASE
; lru
< NR_LRU_LISTS
; lru
++)
5012 pages
[lru
] = global_node_page_state(NR_LRU_BASE
+ lru
);
5015 wmark_low
+= low_wmark_pages(zone
);
5018 * Estimate the amount of memory available for userspace allocations,
5019 * without causing swapping.
5021 available
= global_zone_page_state(NR_FREE_PAGES
) - totalreserve_pages
;
5024 * Not all the page cache can be freed, otherwise the system will
5025 * start swapping. Assume at least half of the page cache, or the
5026 * low watermark worth of cache, needs to stay.
5028 pagecache
= pages
[LRU_ACTIVE_FILE
] + pages
[LRU_INACTIVE_FILE
];
5029 pagecache
-= min(pagecache
/ 2, wmark_low
);
5030 available
+= pagecache
;
5033 * Part of the reclaimable slab and other kernel memory consists of
5034 * items that are in use, and cannot be freed. Cap this estimate at the
5037 reclaimable
= global_node_page_state(NR_SLAB_RECLAIMABLE
) +
5038 global_node_page_state(NR_KERNEL_MISC_RECLAIMABLE
);
5039 available
+= reclaimable
- min(reclaimable
/ 2, wmark_low
);
5045 EXPORT_SYMBOL_GPL(si_mem_available
);
5047 void si_meminfo(struct sysinfo
*val
)
5049 val
->totalram
= totalram_pages();
5050 val
->sharedram
= global_node_page_state(NR_SHMEM
);
5051 val
->freeram
= global_zone_page_state(NR_FREE_PAGES
);
5052 val
->bufferram
= nr_blockdev_pages();
5053 val
->totalhigh
= totalhigh_pages();
5054 val
->freehigh
= nr_free_highpages();
5055 val
->mem_unit
= PAGE_SIZE
;
5058 EXPORT_SYMBOL(si_meminfo
);
5061 void si_meminfo_node(struct sysinfo
*val
, int nid
)
5063 int zone_type
; /* needs to be signed */
5064 unsigned long managed_pages
= 0;
5065 unsigned long managed_highpages
= 0;
5066 unsigned long free_highpages
= 0;
5067 pg_data_t
*pgdat
= NODE_DATA(nid
);
5069 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
5070 managed_pages
+= zone_managed_pages(&pgdat
->node_zones
[zone_type
]);
5071 val
->totalram
= managed_pages
;
5072 val
->sharedram
= node_page_state(pgdat
, NR_SHMEM
);
5073 val
->freeram
= sum_zone_node_page_state(nid
, NR_FREE_PAGES
);
5074 #ifdef CONFIG_HIGHMEM
5075 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
5076 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
5078 if (is_highmem(zone
)) {
5079 managed_highpages
+= zone_managed_pages(zone
);
5080 free_highpages
+= zone_page_state(zone
, NR_FREE_PAGES
);
5083 val
->totalhigh
= managed_highpages
;
5084 val
->freehigh
= free_highpages
;
5086 val
->totalhigh
= managed_highpages
;
5087 val
->freehigh
= free_highpages
;
5089 val
->mem_unit
= PAGE_SIZE
;
5094 * Determine whether the node should be displayed or not, depending on whether
5095 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
5097 static bool show_mem_node_skip(unsigned int flags
, int nid
, nodemask_t
*nodemask
)
5099 if (!(flags
& SHOW_MEM_FILTER_NODES
))
5103 * no node mask - aka implicit memory numa policy. Do not bother with
5104 * the synchronization - read_mems_allowed_begin - because we do not
5105 * have to be precise here.
5108 nodemask
= &cpuset_current_mems_allowed
;
5110 return !node_isset(nid
, *nodemask
);
5113 #define K(x) ((x) << (PAGE_SHIFT-10))
5115 static void show_migration_types(unsigned char type
)
5117 static const char types
[MIGRATE_TYPES
] = {
5118 [MIGRATE_UNMOVABLE
] = 'U',
5119 [MIGRATE_MOVABLE
] = 'M',
5120 [MIGRATE_RECLAIMABLE
] = 'E',
5121 [MIGRATE_HIGHATOMIC
] = 'H',
5123 [MIGRATE_CMA
] = 'C',
5125 #ifdef CONFIG_MEMORY_ISOLATION
5126 [MIGRATE_ISOLATE
] = 'I',
5129 char tmp
[MIGRATE_TYPES
+ 1];
5133 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
5134 if (type
& (1 << i
))
5139 printk(KERN_CONT
"(%s) ", tmp
);
5143 * Show free area list (used inside shift_scroll-lock stuff)
5144 * We also calculate the percentage fragmentation. We do this by counting the
5145 * memory on each free list with the exception of the first item on the list.
5148 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
5151 void show_free_areas(unsigned int filter
, nodemask_t
*nodemask
)
5153 unsigned long free_pcp
= 0;
5158 for_each_populated_zone(zone
) {
5159 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
5162 for_each_online_cpu(cpu
)
5163 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
5166 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
5167 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
5168 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
5169 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
5170 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
5171 " free:%lu free_pcp:%lu free_cma:%lu\n",
5172 global_node_page_state(NR_ACTIVE_ANON
),
5173 global_node_page_state(NR_INACTIVE_ANON
),
5174 global_node_page_state(NR_ISOLATED_ANON
),
5175 global_node_page_state(NR_ACTIVE_FILE
),
5176 global_node_page_state(NR_INACTIVE_FILE
),
5177 global_node_page_state(NR_ISOLATED_FILE
),
5178 global_node_page_state(NR_UNEVICTABLE
),
5179 global_node_page_state(NR_FILE_DIRTY
),
5180 global_node_page_state(NR_WRITEBACK
),
5181 global_node_page_state(NR_UNSTABLE_NFS
),
5182 global_node_page_state(NR_SLAB_RECLAIMABLE
),
5183 global_node_page_state(NR_SLAB_UNRECLAIMABLE
),
5184 global_node_page_state(NR_FILE_MAPPED
),
5185 global_node_page_state(NR_SHMEM
),
5186 global_zone_page_state(NR_PAGETABLE
),
5187 global_zone_page_state(NR_BOUNCE
),
5188 global_zone_page_state(NR_FREE_PAGES
),
5190 global_zone_page_state(NR_FREE_CMA_PAGES
));
5192 for_each_online_pgdat(pgdat
) {
5193 if (show_mem_node_skip(filter
, pgdat
->node_id
, nodemask
))
5197 " active_anon:%lukB"
5198 " inactive_anon:%lukB"
5199 " active_file:%lukB"
5200 " inactive_file:%lukB"
5201 " unevictable:%lukB"
5202 " isolated(anon):%lukB"
5203 " isolated(file):%lukB"
5208 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5210 " shmem_pmdmapped: %lukB"
5213 " writeback_tmp:%lukB"
5215 " all_unreclaimable? %s"
5218 K(node_page_state(pgdat
, NR_ACTIVE_ANON
)),
5219 K(node_page_state(pgdat
, NR_INACTIVE_ANON
)),
5220 K(node_page_state(pgdat
, NR_ACTIVE_FILE
)),
5221 K(node_page_state(pgdat
, NR_INACTIVE_FILE
)),
5222 K(node_page_state(pgdat
, NR_UNEVICTABLE
)),
5223 K(node_page_state(pgdat
, NR_ISOLATED_ANON
)),
5224 K(node_page_state(pgdat
, NR_ISOLATED_FILE
)),
5225 K(node_page_state(pgdat
, NR_FILE_MAPPED
)),
5226 K(node_page_state(pgdat
, NR_FILE_DIRTY
)),
5227 K(node_page_state(pgdat
, NR_WRITEBACK
)),
5228 K(node_page_state(pgdat
, NR_SHMEM
)),
5229 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5230 K(node_page_state(pgdat
, NR_SHMEM_THPS
) * HPAGE_PMD_NR
),
5231 K(node_page_state(pgdat
, NR_SHMEM_PMDMAPPED
)
5233 K(node_page_state(pgdat
, NR_ANON_THPS
) * HPAGE_PMD_NR
),
5235 K(node_page_state(pgdat
, NR_WRITEBACK_TEMP
)),
5236 K(node_page_state(pgdat
, NR_UNSTABLE_NFS
)),
5237 pgdat
->kswapd_failures
>= MAX_RECLAIM_RETRIES
?
5241 for_each_populated_zone(zone
) {
5244 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
5248 for_each_online_cpu(cpu
)
5249 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
5258 " active_anon:%lukB"
5259 " inactive_anon:%lukB"
5260 " active_file:%lukB"
5261 " inactive_file:%lukB"
5262 " unevictable:%lukB"
5263 " writepending:%lukB"
5267 " kernel_stack:%lukB"
5275 K(zone_page_state(zone
, NR_FREE_PAGES
)),
5276 K(min_wmark_pages(zone
)),
5277 K(low_wmark_pages(zone
)),
5278 K(high_wmark_pages(zone
)),
5279 K(zone_page_state(zone
, NR_ZONE_ACTIVE_ANON
)),
5280 K(zone_page_state(zone
, NR_ZONE_INACTIVE_ANON
)),
5281 K(zone_page_state(zone
, NR_ZONE_ACTIVE_FILE
)),
5282 K(zone_page_state(zone
, NR_ZONE_INACTIVE_FILE
)),
5283 K(zone_page_state(zone
, NR_ZONE_UNEVICTABLE
)),
5284 K(zone_page_state(zone
, NR_ZONE_WRITE_PENDING
)),
5285 K(zone
->present_pages
),
5286 K(zone_managed_pages(zone
)),
5287 K(zone_page_state(zone
, NR_MLOCK
)),
5288 zone_page_state(zone
, NR_KERNEL_STACK_KB
),
5289 K(zone_page_state(zone
, NR_PAGETABLE
)),
5290 K(zone_page_state(zone
, NR_BOUNCE
)),
5292 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
5293 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)));
5294 printk("lowmem_reserve[]:");
5295 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
5296 printk(KERN_CONT
" %ld", zone
->lowmem_reserve
[i
]);
5297 printk(KERN_CONT
"\n");
5300 for_each_populated_zone(zone
) {
5302 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
5303 unsigned char types
[MAX_ORDER
];
5305 if (show_mem_node_skip(filter
, zone_to_nid(zone
), nodemask
))
5308 printk(KERN_CONT
"%s: ", zone
->name
);
5310 spin_lock_irqsave(&zone
->lock
, flags
);
5311 for (order
= 0; order
< MAX_ORDER
; order
++) {
5312 struct free_area
*area
= &zone
->free_area
[order
];
5315 nr
[order
] = area
->nr_free
;
5316 total
+= nr
[order
] << order
;
5319 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
5320 if (!free_area_empty(area
, type
))
5321 types
[order
] |= 1 << type
;
5324 spin_unlock_irqrestore(&zone
->lock
, flags
);
5325 for (order
= 0; order
< MAX_ORDER
; order
++) {
5326 printk(KERN_CONT
"%lu*%lukB ",
5327 nr
[order
], K(1UL) << order
);
5329 show_migration_types(types
[order
]);
5331 printk(KERN_CONT
"= %lukB\n", K(total
));
5334 hugetlb_show_meminfo();
5336 printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES
));
5338 show_swap_cache_info();
5341 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
5343 zoneref
->zone
= zone
;
5344 zoneref
->zone_idx
= zone_idx(zone
);
5348 * Builds allocation fallback zone lists.
5350 * Add all populated zones of a node to the zonelist.
5352 static int build_zonerefs_node(pg_data_t
*pgdat
, struct zoneref
*zonerefs
)
5355 enum zone_type zone_type
= MAX_NR_ZONES
;
5360 zone
= pgdat
->node_zones
+ zone_type
;
5361 if (managed_zone(zone
)) {
5362 zoneref_set_zone(zone
, &zonerefs
[nr_zones
++]);
5363 check_highest_zone(zone_type
);
5365 } while (zone_type
);
5372 static int __parse_numa_zonelist_order(char *s
)
5375 * We used to support different zonlists modes but they turned
5376 * out to be just not useful. Let's keep the warning in place
5377 * if somebody still use the cmd line parameter so that we do
5378 * not fail it silently
5380 if (!(*s
== 'd' || *s
== 'D' || *s
== 'n' || *s
== 'N')) {
5381 pr_warn("Ignoring unsupported numa_zonelist_order value: %s\n", s
);
5387 static __init
int setup_numa_zonelist_order(char *s
)
5392 return __parse_numa_zonelist_order(s
);
5394 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
5396 char numa_zonelist_order
[] = "Node";
5399 * sysctl handler for numa_zonelist_order
5401 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
5402 void __user
*buffer
, size_t *length
,
5409 return proc_dostring(table
, write
, buffer
, length
, ppos
);
5410 str
= memdup_user_nul(buffer
, 16);
5412 return PTR_ERR(str
);
5414 ret
= __parse_numa_zonelist_order(str
);
5420 #define MAX_NODE_LOAD (nr_online_nodes)
5421 static int node_load
[MAX_NUMNODES
];
5424 * find_next_best_node - find the next node that should appear in a given node's fallback list
5425 * @node: node whose fallback list we're appending
5426 * @used_node_mask: nodemask_t of already used nodes
5428 * We use a number of factors to determine which is the next node that should
5429 * appear on a given node's fallback list. The node should not have appeared
5430 * already in @node's fallback list, and it should be the next closest node
5431 * according to the distance array (which contains arbitrary distance values
5432 * from each node to each node in the system), and should also prefer nodes
5433 * with no CPUs, since presumably they'll have very little allocation pressure
5434 * on them otherwise.
5436 * Return: node id of the found node or %NUMA_NO_NODE if no node is found.
5438 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
5441 int min_val
= INT_MAX
;
5442 int best_node
= NUMA_NO_NODE
;
5443 const struct cpumask
*tmp
= cpumask_of_node(0);
5445 /* Use the local node if we haven't already */
5446 if (!node_isset(node
, *used_node_mask
)) {
5447 node_set(node
, *used_node_mask
);
5451 for_each_node_state(n
, N_MEMORY
) {
5453 /* Don't want a node to appear more than once */
5454 if (node_isset(n
, *used_node_mask
))
5457 /* Use the distance array to find the distance */
5458 val
= node_distance(node
, n
);
5460 /* Penalize nodes under us ("prefer the next node") */
5463 /* Give preference to headless and unused nodes */
5464 tmp
= cpumask_of_node(n
);
5465 if (!cpumask_empty(tmp
))
5466 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
5468 /* Slight preference for less loaded node */
5469 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
5470 val
+= node_load
[n
];
5472 if (val
< min_val
) {
5479 node_set(best_node
, *used_node_mask
);
5486 * Build zonelists ordered by node and zones within node.
5487 * This results in maximum locality--normal zone overflows into local
5488 * DMA zone, if any--but risks exhausting DMA zone.
5490 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int *node_order
,
5493 struct zoneref
*zonerefs
;
5496 zonerefs
= pgdat
->node_zonelists
[ZONELIST_FALLBACK
]._zonerefs
;
5498 for (i
= 0; i
< nr_nodes
; i
++) {
5501 pg_data_t
*node
= NODE_DATA(node_order
[i
]);
5503 nr_zones
= build_zonerefs_node(node
, zonerefs
);
5504 zonerefs
+= nr_zones
;
5506 zonerefs
->zone
= NULL
;
5507 zonerefs
->zone_idx
= 0;
5511 * Build gfp_thisnode zonelists
5513 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
5515 struct zoneref
*zonerefs
;
5518 zonerefs
= pgdat
->node_zonelists
[ZONELIST_NOFALLBACK
]._zonerefs
;
5519 nr_zones
= build_zonerefs_node(pgdat
, zonerefs
);
5520 zonerefs
+= nr_zones
;
5521 zonerefs
->zone
= NULL
;
5522 zonerefs
->zone_idx
= 0;
5526 * Build zonelists ordered by zone and nodes within zones.
5527 * This results in conserving DMA zone[s] until all Normal memory is
5528 * exhausted, but results in overflowing to remote node while memory
5529 * may still exist in local DMA zone.
5532 static void build_zonelists(pg_data_t
*pgdat
)
5534 static int node_order
[MAX_NUMNODES
];
5535 int node
, load
, nr_nodes
= 0;
5536 nodemask_t used_mask
;
5537 int local_node
, prev_node
;
5539 /* NUMA-aware ordering of nodes */
5540 local_node
= pgdat
->node_id
;
5541 load
= nr_online_nodes
;
5542 prev_node
= local_node
;
5543 nodes_clear(used_mask
);
5545 memset(node_order
, 0, sizeof(node_order
));
5546 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
5548 * We don't want to pressure a particular node.
5549 * So adding penalty to the first node in same
5550 * distance group to make it round-robin.
5552 if (node_distance(local_node
, node
) !=
5553 node_distance(local_node
, prev_node
))
5554 node_load
[node
] = load
;
5556 node_order
[nr_nodes
++] = node
;
5561 build_zonelists_in_node_order(pgdat
, node_order
, nr_nodes
);
5562 build_thisnode_zonelists(pgdat
);
5565 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5567 * Return node id of node used for "local" allocations.
5568 * I.e., first node id of first zone in arg node's generic zonelist.
5569 * Used for initializing percpu 'numa_mem', which is used primarily
5570 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
5572 int local_memory_node(int node
)
5576 z
= first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
5577 gfp_zone(GFP_KERNEL
),
5579 return zone_to_nid(z
->zone
);
5583 static void setup_min_unmapped_ratio(void);
5584 static void setup_min_slab_ratio(void);
5585 #else /* CONFIG_NUMA */
5587 static void build_zonelists(pg_data_t
*pgdat
)
5589 int node
, local_node
;
5590 struct zoneref
*zonerefs
;
5593 local_node
= pgdat
->node_id
;
5595 zonerefs
= pgdat
->node_zonelists
[ZONELIST_FALLBACK
]._zonerefs
;
5596 nr_zones
= build_zonerefs_node(pgdat
, zonerefs
);
5597 zonerefs
+= nr_zones
;
5600 * Now we build the zonelist so that it contains the zones
5601 * of all the other nodes.
5602 * We don't want to pressure a particular node, so when
5603 * building the zones for node N, we make sure that the
5604 * zones coming right after the local ones are those from
5605 * node N+1 (modulo N)
5607 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
5608 if (!node_online(node
))
5610 nr_zones
= build_zonerefs_node(NODE_DATA(node
), zonerefs
);
5611 zonerefs
+= nr_zones
;
5613 for (node
= 0; node
< local_node
; node
++) {
5614 if (!node_online(node
))
5616 nr_zones
= build_zonerefs_node(NODE_DATA(node
), zonerefs
);
5617 zonerefs
+= nr_zones
;
5620 zonerefs
->zone
= NULL
;
5621 zonerefs
->zone_idx
= 0;
5624 #endif /* CONFIG_NUMA */
5627 * Boot pageset table. One per cpu which is going to be used for all
5628 * zones and all nodes. The parameters will be set in such a way
5629 * that an item put on a list will immediately be handed over to
5630 * the buddy list. This is safe since pageset manipulation is done
5631 * with interrupts disabled.
5633 * The boot_pagesets must be kept even after bootup is complete for
5634 * unused processors and/or zones. They do play a role for bootstrapping
5635 * hotplugged processors.
5637 * zoneinfo_show() and maybe other functions do
5638 * not check if the processor is online before following the pageset pointer.
5639 * Other parts of the kernel may not check if the zone is available.
5641 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
5642 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
5643 static DEFINE_PER_CPU(struct per_cpu_nodestat
, boot_nodestats
);
5645 static void __build_all_zonelists(void *data
)
5648 int __maybe_unused cpu
;
5649 pg_data_t
*self
= data
;
5650 static DEFINE_SPINLOCK(lock
);
5655 memset(node_load
, 0, sizeof(node_load
));
5659 * This node is hotadded and no memory is yet present. So just
5660 * building zonelists is fine - no need to touch other nodes.
5662 if (self
&& !node_online(self
->node_id
)) {
5663 build_zonelists(self
);
5665 for_each_online_node(nid
) {
5666 pg_data_t
*pgdat
= NODE_DATA(nid
);
5668 build_zonelists(pgdat
);
5671 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
5673 * We now know the "local memory node" for each node--
5674 * i.e., the node of the first zone in the generic zonelist.
5675 * Set up numa_mem percpu variable for on-line cpus. During
5676 * boot, only the boot cpu should be on-line; we'll init the
5677 * secondary cpus' numa_mem as they come on-line. During
5678 * node/memory hotplug, we'll fixup all on-line cpus.
5680 for_each_online_cpu(cpu
)
5681 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
5688 static noinline
void __init
5689 build_all_zonelists_init(void)
5693 __build_all_zonelists(NULL
);
5696 * Initialize the boot_pagesets that are going to be used
5697 * for bootstrapping processors. The real pagesets for
5698 * each zone will be allocated later when the per cpu
5699 * allocator is available.
5701 * boot_pagesets are used also for bootstrapping offline
5702 * cpus if the system is already booted because the pagesets
5703 * are needed to initialize allocators on a specific cpu too.
5704 * F.e. the percpu allocator needs the page allocator which
5705 * needs the percpu allocator in order to allocate its pagesets
5706 * (a chicken-egg dilemma).
5708 for_each_possible_cpu(cpu
)
5709 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
5711 mminit_verify_zonelist();
5712 cpuset_init_current_mems_allowed();
5716 * unless system_state == SYSTEM_BOOTING.
5718 * __ref due to call of __init annotated helper build_all_zonelists_init
5719 * [protected by SYSTEM_BOOTING].
5721 void __ref
build_all_zonelists(pg_data_t
*pgdat
)
5723 if (system_state
== SYSTEM_BOOTING
) {
5724 build_all_zonelists_init();
5726 __build_all_zonelists(pgdat
);
5727 /* cpuset refresh routine should be here */
5729 vm_total_pages
= nr_free_pagecache_pages();
5731 * Disable grouping by mobility if the number of pages in the
5732 * system is too low to allow the mechanism to work. It would be
5733 * more accurate, but expensive to check per-zone. This check is
5734 * made on memory-hotadd so a system can start with mobility
5735 * disabled and enable it later
5737 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
5738 page_group_by_mobility_disabled
= 1;
5740 page_group_by_mobility_disabled
= 0;
5742 pr_info("Built %u zonelists, mobility grouping %s. Total pages: %ld\n",
5744 page_group_by_mobility_disabled
? "off" : "on",
5747 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
5751 /* If zone is ZONE_MOVABLE but memory is mirrored, it is an overlapped init */
5752 static bool __meminit
5753 overlap_memmap_init(unsigned long zone
, unsigned long *pfn
)
5755 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5756 static struct memblock_region
*r
;
5758 if (mirrored_kernelcore
&& zone
== ZONE_MOVABLE
) {
5759 if (!r
|| *pfn
>= memblock_region_memory_end_pfn(r
)) {
5760 for_each_memblock(memory
, r
) {
5761 if (*pfn
< memblock_region_memory_end_pfn(r
))
5765 if (*pfn
>= memblock_region_memory_base_pfn(r
) &&
5766 memblock_is_mirror(r
)) {
5767 *pfn
= memblock_region_memory_end_pfn(r
);
5776 * Initially all pages are reserved - free ones are freed
5777 * up by memblock_free_all() once the early boot process is
5778 * done. Non-atomic initialization, single-pass.
5780 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
5781 unsigned long start_pfn
, enum memmap_context context
,
5782 struct vmem_altmap
*altmap
)
5784 unsigned long pfn
, end_pfn
= start_pfn
+ size
;
5787 if (highest_memmap_pfn
< end_pfn
- 1)
5788 highest_memmap_pfn
= end_pfn
- 1;
5790 #ifdef CONFIG_ZONE_DEVICE
5792 * Honor reservation requested by the driver for this ZONE_DEVICE
5793 * memory. We limit the total number of pages to initialize to just
5794 * those that might contain the memory mapping. We will defer the
5795 * ZONE_DEVICE page initialization until after we have released
5798 if (zone
== ZONE_DEVICE
) {
5802 if (start_pfn
== altmap
->base_pfn
)
5803 start_pfn
+= altmap
->reserve
;
5804 end_pfn
= altmap
->base_pfn
+ vmem_altmap_offset(altmap
);
5808 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
5810 * There can be holes in boot-time mem_map[]s handed to this
5811 * function. They do not exist on hotplugged memory.
5813 if (context
== MEMMAP_EARLY
) {
5814 if (!early_pfn_valid(pfn
))
5816 if (!early_pfn_in_nid(pfn
, nid
))
5818 if (overlap_memmap_init(zone
, &pfn
))
5820 if (defer_init(nid
, pfn
, end_pfn
))
5824 page
= pfn_to_page(pfn
);
5825 __init_single_page(page
, pfn
, zone
, nid
);
5826 if (context
== MEMMAP_HOTPLUG
)
5827 __SetPageReserved(page
);
5830 * Mark the block movable so that blocks are reserved for
5831 * movable at startup. This will force kernel allocations
5832 * to reserve their blocks rather than leaking throughout
5833 * the address space during boot when many long-lived
5834 * kernel allocations are made.
5836 * bitmap is created for zone's valid pfn range. but memmap
5837 * can be created for invalid pages (for alignment)
5838 * check here not to call set_pageblock_migratetype() against
5841 if (!(pfn
& (pageblock_nr_pages
- 1))) {
5842 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
5848 #ifdef CONFIG_ZONE_DEVICE
5849 void __ref
memmap_init_zone_device(struct zone
*zone
,
5850 unsigned long start_pfn
,
5852 struct dev_pagemap
*pgmap
)
5854 unsigned long pfn
, end_pfn
= start_pfn
+ size
;
5855 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
5856 unsigned long zone_idx
= zone_idx(zone
);
5857 unsigned long start
= jiffies
;
5858 int nid
= pgdat
->node_id
;
5860 if (WARN_ON_ONCE(!pgmap
|| !is_dev_zone(zone
)))
5864 * The call to memmap_init_zone should have already taken care
5865 * of the pages reserved for the memmap, so we can just jump to
5866 * the end of that region and start processing the device pages.
5868 if (pgmap
->altmap_valid
) {
5869 struct vmem_altmap
*altmap
= &pgmap
->altmap
;
5871 start_pfn
= altmap
->base_pfn
+ vmem_altmap_offset(altmap
);
5872 size
= end_pfn
- start_pfn
;
5875 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
5876 struct page
*page
= pfn_to_page(pfn
);
5878 __init_single_page(page
, pfn
, zone_idx
, nid
);
5881 * Mark page reserved as it will need to wait for onlining
5882 * phase for it to be fully associated with a zone.
5884 * We can use the non-atomic __set_bit operation for setting
5885 * the flag as we are still initializing the pages.
5887 __SetPageReserved(page
);
5890 * ZONE_DEVICE pages union ->lru with a ->pgmap back
5891 * pointer and hmm_data. It is a bug if a ZONE_DEVICE
5892 * page is ever freed or placed on a driver-private list.
5894 page
->pgmap
= pgmap
;
5898 * Mark the block movable so that blocks are reserved for
5899 * movable at startup. This will force kernel allocations
5900 * to reserve their blocks rather than leaking throughout
5901 * the address space during boot when many long-lived
5902 * kernel allocations are made.
5904 * bitmap is created for zone's valid pfn range. but memmap
5905 * can be created for invalid pages (for alignment)
5906 * check here not to call set_pageblock_migratetype() against
5909 * Please note that MEMMAP_HOTPLUG path doesn't clear memmap
5910 * because this is done early in sparse_add_one_section
5912 if (!(pfn
& (pageblock_nr_pages
- 1))) {
5913 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
5918 pr_info("%s initialised, %lu pages in %ums\n", dev_name(pgmap
->dev
),
5919 size
, jiffies_to_msecs(jiffies
- start
));
5923 static void __meminit
zone_init_free_lists(struct zone
*zone
)
5925 unsigned int order
, t
;
5926 for_each_migratetype_order(order
, t
) {
5927 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
5928 zone
->free_area
[order
].nr_free
= 0;
5932 void __meminit __weak
memmap_init(unsigned long size
, int nid
,
5933 unsigned long zone
, unsigned long start_pfn
)
5935 memmap_init_zone(size
, nid
, zone
, start_pfn
, MEMMAP_EARLY
, NULL
);
5938 static int zone_batchsize(struct zone
*zone
)
5944 * The per-cpu-pages pools are set to around 1000th of the
5947 batch
= zone_managed_pages(zone
) / 1024;
5948 /* But no more than a meg. */
5949 if (batch
* PAGE_SIZE
> 1024 * 1024)
5950 batch
= (1024 * 1024) / PAGE_SIZE
;
5951 batch
/= 4; /* We effectively *= 4 below */
5956 * Clamp the batch to a 2^n - 1 value. Having a power
5957 * of 2 value was found to be more likely to have
5958 * suboptimal cache aliasing properties in some cases.
5960 * For example if 2 tasks are alternately allocating
5961 * batches of pages, one task can end up with a lot
5962 * of pages of one half of the possible page colors
5963 * and the other with pages of the other colors.
5965 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
5970 /* The deferral and batching of frees should be suppressed under NOMMU
5973 * The problem is that NOMMU needs to be able to allocate large chunks
5974 * of contiguous memory as there's no hardware page translation to
5975 * assemble apparent contiguous memory from discontiguous pages.
5977 * Queueing large contiguous runs of pages for batching, however,
5978 * causes the pages to actually be freed in smaller chunks. As there
5979 * can be a significant delay between the individual batches being
5980 * recycled, this leads to the once large chunks of space being
5981 * fragmented and becoming unavailable for high-order allocations.
5988 * pcp->high and pcp->batch values are related and dependent on one another:
5989 * ->batch must never be higher then ->high.
5990 * The following function updates them in a safe manner without read side
5993 * Any new users of pcp->batch and pcp->high should ensure they can cope with
5994 * those fields changing asynchronously (acording the the above rule).
5996 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
5997 * outside of boot time (or some other assurance that no concurrent updaters
6000 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
6001 unsigned long batch
)
6003 /* start with a fail safe value for batch */
6007 /* Update high, then batch, in order */
6014 /* a companion to pageset_set_high() */
6015 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
6017 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
6020 static void pageset_init(struct per_cpu_pageset
*p
)
6022 struct per_cpu_pages
*pcp
;
6025 memset(p
, 0, sizeof(*p
));
6028 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
6029 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
6032 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
6035 pageset_set_batch(p
, batch
);
6039 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
6040 * to the value high for the pageset p.
6042 static void pageset_set_high(struct per_cpu_pageset
*p
,
6045 unsigned long batch
= max(1UL, high
/ 4);
6046 if ((high
/ 4) > (PAGE_SHIFT
* 8))
6047 batch
= PAGE_SHIFT
* 8;
6049 pageset_update(&p
->pcp
, high
, batch
);
6052 static void pageset_set_high_and_batch(struct zone
*zone
,
6053 struct per_cpu_pageset
*pcp
)
6055 if (percpu_pagelist_fraction
)
6056 pageset_set_high(pcp
,
6057 (zone_managed_pages(zone
) /
6058 percpu_pagelist_fraction
));
6060 pageset_set_batch(pcp
, zone_batchsize(zone
));
6063 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
6065 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
6068 pageset_set_high_and_batch(zone
, pcp
);
6071 void __meminit
setup_zone_pageset(struct zone
*zone
)
6074 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
6075 for_each_possible_cpu(cpu
)
6076 zone_pageset_init(zone
, cpu
);
6080 * Allocate per cpu pagesets and initialize them.
6081 * Before this call only boot pagesets were available.
6083 void __init
setup_per_cpu_pageset(void)
6085 struct pglist_data
*pgdat
;
6088 for_each_populated_zone(zone
)
6089 setup_zone_pageset(zone
);
6091 for_each_online_pgdat(pgdat
)
6092 pgdat
->per_cpu_nodestats
=
6093 alloc_percpu(struct per_cpu_nodestat
);
6096 static __meminit
void zone_pcp_init(struct zone
*zone
)
6099 * per cpu subsystem is not up at this point. The following code
6100 * relies on the ability of the linker to provide the
6101 * offset of a (static) per cpu variable into the per cpu area.
6103 zone
->pageset
= &boot_pageset
;
6105 if (populated_zone(zone
))
6106 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
6107 zone
->name
, zone
->present_pages
,
6108 zone_batchsize(zone
));
6111 void __meminit
init_currently_empty_zone(struct zone
*zone
,
6112 unsigned long zone_start_pfn
,
6115 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
6116 int zone_idx
= zone_idx(zone
) + 1;
6118 if (zone_idx
> pgdat
->nr_zones
)
6119 pgdat
->nr_zones
= zone_idx
;
6121 zone
->zone_start_pfn
= zone_start_pfn
;
6123 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
6124 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
6126 (unsigned long)zone_idx(zone
),
6127 zone_start_pfn
, (zone_start_pfn
+ size
));
6129 zone_init_free_lists(zone
);
6130 zone
->initialized
= 1;
6133 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6134 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
6137 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
6139 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
6140 struct mminit_pfnnid_cache
*state
)
6142 unsigned long start_pfn
, end_pfn
;
6145 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
6146 return state
->last_nid
;
6148 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
6149 if (nid
!= NUMA_NO_NODE
) {
6150 state
->last_start
= start_pfn
;
6151 state
->last_end
= end_pfn
;
6152 state
->last_nid
= nid
;
6157 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
6160 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
6161 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
6162 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
6164 * If an architecture guarantees that all ranges registered contain no holes
6165 * and may be freed, this this function may be used instead of calling
6166 * memblock_free_early_nid() manually.
6168 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
6170 unsigned long start_pfn
, end_pfn
;
6173 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
6174 start_pfn
= min(start_pfn
, max_low_pfn
);
6175 end_pfn
= min(end_pfn
, max_low_pfn
);
6177 if (start_pfn
< end_pfn
)
6178 memblock_free_early_nid(PFN_PHYS(start_pfn
),
6179 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
6185 * sparse_memory_present_with_active_regions - Call memory_present for each active range
6186 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
6188 * If an architecture guarantees that all ranges registered contain no holes and may
6189 * be freed, this function may be used instead of calling memory_present() manually.
6191 void __init
sparse_memory_present_with_active_regions(int nid
)
6193 unsigned long start_pfn
, end_pfn
;
6196 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
6197 memory_present(this_nid
, start_pfn
, end_pfn
);
6201 * get_pfn_range_for_nid - Return the start and end page frames for a node
6202 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
6203 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
6204 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
6206 * It returns the start and end page frame of a node based on information
6207 * provided by memblock_set_node(). If called for a node
6208 * with no available memory, a warning is printed and the start and end
6211 void __init
get_pfn_range_for_nid(unsigned int nid
,
6212 unsigned long *start_pfn
, unsigned long *end_pfn
)
6214 unsigned long this_start_pfn
, this_end_pfn
;
6220 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
6221 *start_pfn
= min(*start_pfn
, this_start_pfn
);
6222 *end_pfn
= max(*end_pfn
, this_end_pfn
);
6225 if (*start_pfn
== -1UL)
6230 * This finds a zone that can be used for ZONE_MOVABLE pages. The
6231 * assumption is made that zones within a node are ordered in monotonic
6232 * increasing memory addresses so that the "highest" populated zone is used
6234 static void __init
find_usable_zone_for_movable(void)
6237 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
6238 if (zone_index
== ZONE_MOVABLE
)
6241 if (arch_zone_highest_possible_pfn
[zone_index
] >
6242 arch_zone_lowest_possible_pfn
[zone_index
])
6246 VM_BUG_ON(zone_index
== -1);
6247 movable_zone
= zone_index
;
6251 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
6252 * because it is sized independent of architecture. Unlike the other zones,
6253 * the starting point for ZONE_MOVABLE is not fixed. It may be different
6254 * in each node depending on the size of each node and how evenly kernelcore
6255 * is distributed. This helper function adjusts the zone ranges
6256 * provided by the architecture for a given node by using the end of the
6257 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
6258 * zones within a node are in order of monotonic increases memory addresses
6260 static void __init
adjust_zone_range_for_zone_movable(int nid
,
6261 unsigned long zone_type
,
6262 unsigned long node_start_pfn
,
6263 unsigned long node_end_pfn
,
6264 unsigned long *zone_start_pfn
,
6265 unsigned long *zone_end_pfn
)
6267 /* Only adjust if ZONE_MOVABLE is on this node */
6268 if (zone_movable_pfn
[nid
]) {
6269 /* Size ZONE_MOVABLE */
6270 if (zone_type
== ZONE_MOVABLE
) {
6271 *zone_start_pfn
= zone_movable_pfn
[nid
];
6272 *zone_end_pfn
= min(node_end_pfn
,
6273 arch_zone_highest_possible_pfn
[movable_zone
]);
6275 /* Adjust for ZONE_MOVABLE starting within this range */
6276 } else if (!mirrored_kernelcore
&&
6277 *zone_start_pfn
< zone_movable_pfn
[nid
] &&
6278 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
6279 *zone_end_pfn
= zone_movable_pfn
[nid
];
6281 /* Check if this whole range is within ZONE_MOVABLE */
6282 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
6283 *zone_start_pfn
= *zone_end_pfn
;
6288 * Return the number of pages a zone spans in a node, including holes
6289 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
6291 static unsigned long __init
zone_spanned_pages_in_node(int nid
,
6292 unsigned long zone_type
,
6293 unsigned long node_start_pfn
,
6294 unsigned long node_end_pfn
,
6295 unsigned long *zone_start_pfn
,
6296 unsigned long *zone_end_pfn
,
6297 unsigned long *ignored
)
6299 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
6300 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
6301 /* When hotadd a new node from cpu_up(), the node should be empty */
6302 if (!node_start_pfn
&& !node_end_pfn
)
6305 /* Get the start and end of the zone */
6306 *zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
6307 *zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
6308 adjust_zone_range_for_zone_movable(nid
, zone_type
,
6309 node_start_pfn
, node_end_pfn
,
6310 zone_start_pfn
, zone_end_pfn
);
6312 /* Check that this node has pages within the zone's required range */
6313 if (*zone_end_pfn
< node_start_pfn
|| *zone_start_pfn
> node_end_pfn
)
6316 /* Move the zone boundaries inside the node if necessary */
6317 *zone_end_pfn
= min(*zone_end_pfn
, node_end_pfn
);
6318 *zone_start_pfn
= max(*zone_start_pfn
, node_start_pfn
);
6320 /* Return the spanned pages */
6321 return *zone_end_pfn
- *zone_start_pfn
;
6325 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
6326 * then all holes in the requested range will be accounted for.
6328 unsigned long __init
__absent_pages_in_range(int nid
,
6329 unsigned long range_start_pfn
,
6330 unsigned long range_end_pfn
)
6332 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
6333 unsigned long start_pfn
, end_pfn
;
6336 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
6337 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
6338 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
6339 nr_absent
-= end_pfn
- start_pfn
;
6345 * absent_pages_in_range - Return number of page frames in holes within a range
6346 * @start_pfn: The start PFN to start searching for holes
6347 * @end_pfn: The end PFN to stop searching for holes
6349 * Return: the number of pages frames in memory holes within a range.
6351 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
6352 unsigned long end_pfn
)
6354 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
6357 /* Return the number of page frames in holes in a zone on a node */
6358 static unsigned long __init
zone_absent_pages_in_node(int nid
,
6359 unsigned long zone_type
,
6360 unsigned long node_start_pfn
,
6361 unsigned long node_end_pfn
,
6362 unsigned long *ignored
)
6364 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
6365 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
6366 unsigned long zone_start_pfn
, zone_end_pfn
;
6367 unsigned long nr_absent
;
6369 /* When hotadd a new node from cpu_up(), the node should be empty */
6370 if (!node_start_pfn
&& !node_end_pfn
)
6373 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
6374 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
6376 adjust_zone_range_for_zone_movable(nid
, zone_type
,
6377 node_start_pfn
, node_end_pfn
,
6378 &zone_start_pfn
, &zone_end_pfn
);
6379 nr_absent
= __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
6382 * ZONE_MOVABLE handling.
6383 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
6386 if (mirrored_kernelcore
&& zone_movable_pfn
[nid
]) {
6387 unsigned long start_pfn
, end_pfn
;
6388 struct memblock_region
*r
;
6390 for_each_memblock(memory
, r
) {
6391 start_pfn
= clamp(memblock_region_memory_base_pfn(r
),
6392 zone_start_pfn
, zone_end_pfn
);
6393 end_pfn
= clamp(memblock_region_memory_end_pfn(r
),
6394 zone_start_pfn
, zone_end_pfn
);
6396 if (zone_type
== ZONE_MOVABLE
&&
6397 memblock_is_mirror(r
))
6398 nr_absent
+= end_pfn
- start_pfn
;
6400 if (zone_type
== ZONE_NORMAL
&&
6401 !memblock_is_mirror(r
))
6402 nr_absent
+= end_pfn
- start_pfn
;
6409 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6410 static inline unsigned long __init
zone_spanned_pages_in_node(int nid
,
6411 unsigned long zone_type
,
6412 unsigned long node_start_pfn
,
6413 unsigned long node_end_pfn
,
6414 unsigned long *zone_start_pfn
,
6415 unsigned long *zone_end_pfn
,
6416 unsigned long *zones_size
)
6420 *zone_start_pfn
= node_start_pfn
;
6421 for (zone
= 0; zone
< zone_type
; zone
++)
6422 *zone_start_pfn
+= zones_size
[zone
];
6424 *zone_end_pfn
= *zone_start_pfn
+ zones_size
[zone_type
];
6426 return zones_size
[zone_type
];
6429 static inline unsigned long __init
zone_absent_pages_in_node(int nid
,
6430 unsigned long zone_type
,
6431 unsigned long node_start_pfn
,
6432 unsigned long node_end_pfn
,
6433 unsigned long *zholes_size
)
6438 return zholes_size
[zone_type
];
6441 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6443 static void __init
calculate_node_totalpages(struct pglist_data
*pgdat
,
6444 unsigned long node_start_pfn
,
6445 unsigned long node_end_pfn
,
6446 unsigned long *zones_size
,
6447 unsigned long *zholes_size
)
6449 unsigned long realtotalpages
= 0, totalpages
= 0;
6452 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6453 struct zone
*zone
= pgdat
->node_zones
+ i
;
6454 unsigned long zone_start_pfn
, zone_end_pfn
;
6455 unsigned long size
, real_size
;
6457 size
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
6463 real_size
= size
- zone_absent_pages_in_node(pgdat
->node_id
, i
,
6464 node_start_pfn
, node_end_pfn
,
6467 zone
->zone_start_pfn
= zone_start_pfn
;
6469 zone
->zone_start_pfn
= 0;
6470 zone
->spanned_pages
= size
;
6471 zone
->present_pages
= real_size
;
6474 realtotalpages
+= real_size
;
6477 pgdat
->node_spanned_pages
= totalpages
;
6478 pgdat
->node_present_pages
= realtotalpages
;
6479 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
6483 #ifndef CONFIG_SPARSEMEM
6485 * Calculate the size of the zone->blockflags rounded to an unsigned long
6486 * Start by making sure zonesize is a multiple of pageblock_order by rounding
6487 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
6488 * round what is now in bits to nearest long in bits, then return it in
6491 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
6493 unsigned long usemapsize
;
6495 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
6496 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
6497 usemapsize
= usemapsize
>> pageblock_order
;
6498 usemapsize
*= NR_PAGEBLOCK_BITS
;
6499 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
6501 return usemapsize
/ 8;
6504 static void __ref
setup_usemap(struct pglist_data
*pgdat
,
6506 unsigned long zone_start_pfn
,
6507 unsigned long zonesize
)
6509 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
6510 zone
->pageblock_flags
= NULL
;
6512 zone
->pageblock_flags
=
6513 memblock_alloc_node(usemapsize
, SMP_CACHE_BYTES
,
6515 if (!zone
->pageblock_flags
)
6516 panic("Failed to allocate %ld bytes for zone %s pageblock flags on node %d\n",
6517 usemapsize
, zone
->name
, pgdat
->node_id
);
6521 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
6522 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
6523 #endif /* CONFIG_SPARSEMEM */
6525 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
6527 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
6528 void __init
set_pageblock_order(void)
6532 /* Check that pageblock_nr_pages has not already been setup */
6533 if (pageblock_order
)
6536 if (HPAGE_SHIFT
> PAGE_SHIFT
)
6537 order
= HUGETLB_PAGE_ORDER
;
6539 order
= MAX_ORDER
- 1;
6542 * Assume the largest contiguous order of interest is a huge page.
6543 * This value may be variable depending on boot parameters on IA64 and
6546 pageblock_order
= order
;
6548 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6551 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
6552 * is unused as pageblock_order is set at compile-time. See
6553 * include/linux/pageblock-flags.h for the values of pageblock_order based on
6556 void __init
set_pageblock_order(void)
6560 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
6562 static unsigned long __init
calc_memmap_size(unsigned long spanned_pages
,
6563 unsigned long present_pages
)
6565 unsigned long pages
= spanned_pages
;
6568 * Provide a more accurate estimation if there are holes within
6569 * the zone and SPARSEMEM is in use. If there are holes within the
6570 * zone, each populated memory region may cost us one or two extra
6571 * memmap pages due to alignment because memmap pages for each
6572 * populated regions may not be naturally aligned on page boundary.
6573 * So the (present_pages >> 4) heuristic is a tradeoff for that.
6575 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
6576 IS_ENABLED(CONFIG_SPARSEMEM
))
6577 pages
= present_pages
;
6579 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
6582 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6583 static void pgdat_init_split_queue(struct pglist_data
*pgdat
)
6585 spin_lock_init(&pgdat
->split_queue_lock
);
6586 INIT_LIST_HEAD(&pgdat
->split_queue
);
6587 pgdat
->split_queue_len
= 0;
6590 static void pgdat_init_split_queue(struct pglist_data
*pgdat
) {}
6593 #ifdef CONFIG_COMPACTION
6594 static void pgdat_init_kcompactd(struct pglist_data
*pgdat
)
6596 init_waitqueue_head(&pgdat
->kcompactd_wait
);
6599 static void pgdat_init_kcompactd(struct pglist_data
*pgdat
) {}
6602 static void __meminit
pgdat_init_internals(struct pglist_data
*pgdat
)
6604 pgdat_resize_init(pgdat
);
6606 pgdat_init_split_queue(pgdat
);
6607 pgdat_init_kcompactd(pgdat
);
6609 init_waitqueue_head(&pgdat
->kswapd_wait
);
6610 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
6612 pgdat_page_ext_init(pgdat
);
6613 spin_lock_init(&pgdat
->lru_lock
);
6614 lruvec_init(node_lruvec(pgdat
));
6617 static void __meminit
zone_init_internals(struct zone
*zone
, enum zone_type idx
, int nid
,
6618 unsigned long remaining_pages
)
6620 atomic_long_set(&zone
->managed_pages
, remaining_pages
);
6621 zone_set_nid(zone
, nid
);
6622 zone
->name
= zone_names
[idx
];
6623 zone
->zone_pgdat
= NODE_DATA(nid
);
6624 spin_lock_init(&zone
->lock
);
6625 zone_seqlock_init(zone
);
6626 zone_pcp_init(zone
);
6630 * Set up the zone data structures
6631 * - init pgdat internals
6632 * - init all zones belonging to this node
6634 * NOTE: this function is only called during memory hotplug
6636 #ifdef CONFIG_MEMORY_HOTPLUG
6637 void __ref
free_area_init_core_hotplug(int nid
)
6640 pg_data_t
*pgdat
= NODE_DATA(nid
);
6642 pgdat_init_internals(pgdat
);
6643 for (z
= 0; z
< MAX_NR_ZONES
; z
++)
6644 zone_init_internals(&pgdat
->node_zones
[z
], z
, nid
, 0);
6649 * Set up the zone data structures:
6650 * - mark all pages reserved
6651 * - mark all memory queues empty
6652 * - clear the memory bitmaps
6654 * NOTE: pgdat should get zeroed by caller.
6655 * NOTE: this function is only called during early init.
6657 static void __init
free_area_init_core(struct pglist_data
*pgdat
)
6660 int nid
= pgdat
->node_id
;
6662 pgdat_init_internals(pgdat
);
6663 pgdat
->per_cpu_nodestats
= &boot_nodestats
;
6665 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6666 struct zone
*zone
= pgdat
->node_zones
+ j
;
6667 unsigned long size
, freesize
, memmap_pages
;
6668 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
6670 size
= zone
->spanned_pages
;
6671 freesize
= zone
->present_pages
;
6674 * Adjust freesize so that it accounts for how much memory
6675 * is used by this zone for memmap. This affects the watermark
6676 * and per-cpu initialisations
6678 memmap_pages
= calc_memmap_size(size
, freesize
);
6679 if (!is_highmem_idx(j
)) {
6680 if (freesize
>= memmap_pages
) {
6681 freesize
-= memmap_pages
;
6684 " %s zone: %lu pages used for memmap\n",
6685 zone_names
[j
], memmap_pages
);
6687 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
6688 zone_names
[j
], memmap_pages
, freesize
);
6691 /* Account for reserved pages */
6692 if (j
== 0 && freesize
> dma_reserve
) {
6693 freesize
-= dma_reserve
;
6694 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
6695 zone_names
[0], dma_reserve
);
6698 if (!is_highmem_idx(j
))
6699 nr_kernel_pages
+= freesize
;
6700 /* Charge for highmem memmap if there are enough kernel pages */
6701 else if (nr_kernel_pages
> memmap_pages
* 2)
6702 nr_kernel_pages
-= memmap_pages
;
6703 nr_all_pages
+= freesize
;
6706 * Set an approximate value for lowmem here, it will be adjusted
6707 * when the bootmem allocator frees pages into the buddy system.
6708 * And all highmem pages will be managed by the buddy system.
6710 zone_init_internals(zone
, j
, nid
, freesize
);
6715 set_pageblock_order();
6716 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
6717 init_currently_empty_zone(zone
, zone_start_pfn
, size
);
6718 memmap_init(size
, nid
, j
, zone_start_pfn
);
6722 #ifdef CONFIG_FLAT_NODE_MEM_MAP
6723 static void __ref
alloc_node_mem_map(struct pglist_data
*pgdat
)
6725 unsigned long __maybe_unused start
= 0;
6726 unsigned long __maybe_unused offset
= 0;
6728 /* Skip empty nodes */
6729 if (!pgdat
->node_spanned_pages
)
6732 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
6733 offset
= pgdat
->node_start_pfn
- start
;
6734 /* ia64 gets its own node_mem_map, before this, without bootmem */
6735 if (!pgdat
->node_mem_map
) {
6736 unsigned long size
, end
;
6740 * The zone's endpoints aren't required to be MAX_ORDER
6741 * aligned but the node_mem_map endpoints must be in order
6742 * for the buddy allocator to function correctly.
6744 end
= pgdat_end_pfn(pgdat
);
6745 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
6746 size
= (end
- start
) * sizeof(struct page
);
6747 map
= memblock_alloc_node(size
, SMP_CACHE_BYTES
,
6750 panic("Failed to allocate %ld bytes for node %d memory map\n",
6751 size
, pgdat
->node_id
);
6752 pgdat
->node_mem_map
= map
+ offset
;
6754 pr_debug("%s: node %d, pgdat %08lx, node_mem_map %08lx\n",
6755 __func__
, pgdat
->node_id
, (unsigned long)pgdat
,
6756 (unsigned long)pgdat
->node_mem_map
);
6757 #ifndef CONFIG_NEED_MULTIPLE_NODES
6759 * With no DISCONTIG, the global mem_map is just set as node 0's
6761 if (pgdat
== NODE_DATA(0)) {
6762 mem_map
= NODE_DATA(0)->node_mem_map
;
6763 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
6764 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
6766 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6771 static void __ref
alloc_node_mem_map(struct pglist_data
*pgdat
) { }
6772 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
6774 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
6775 static inline void pgdat_set_deferred_range(pg_data_t
*pgdat
)
6777 pgdat
->first_deferred_pfn
= ULONG_MAX
;
6780 static inline void pgdat_set_deferred_range(pg_data_t
*pgdat
) {}
6783 void __init
free_area_init_node(int nid
, unsigned long *zones_size
,
6784 unsigned long node_start_pfn
,
6785 unsigned long *zholes_size
)
6787 pg_data_t
*pgdat
= NODE_DATA(nid
);
6788 unsigned long start_pfn
= 0;
6789 unsigned long end_pfn
= 0;
6791 /* pg_data_t should be reset to zero when it's allocated */
6792 WARN_ON(pgdat
->nr_zones
|| pgdat
->kswapd_classzone_idx
);
6794 pgdat
->node_id
= nid
;
6795 pgdat
->node_start_pfn
= node_start_pfn
;
6796 pgdat
->per_cpu_nodestats
= NULL
;
6797 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6798 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
6799 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
6800 (u64
)start_pfn
<< PAGE_SHIFT
,
6801 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
6803 start_pfn
= node_start_pfn
;
6805 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
6806 zones_size
, zholes_size
);
6808 alloc_node_mem_map(pgdat
);
6809 pgdat_set_deferred_range(pgdat
);
6811 free_area_init_core(pgdat
);
6814 #if !defined(CONFIG_FLAT_NODE_MEM_MAP)
6816 * Zero all valid struct pages in range [spfn, epfn), return number of struct
6819 static u64
zero_pfn_range(unsigned long spfn
, unsigned long epfn
)
6824 for (pfn
= spfn
; pfn
< epfn
; pfn
++) {
6825 if (!pfn_valid(ALIGN_DOWN(pfn
, pageblock_nr_pages
))) {
6826 pfn
= ALIGN_DOWN(pfn
, pageblock_nr_pages
)
6827 + pageblock_nr_pages
- 1;
6830 mm_zero_struct_page(pfn_to_page(pfn
));
6838 * Only struct pages that are backed by physical memory are zeroed and
6839 * initialized by going through __init_single_page(). But, there are some
6840 * struct pages which are reserved in memblock allocator and their fields
6841 * may be accessed (for example page_to_pfn() on some configuration accesses
6842 * flags). We must explicitly zero those struct pages.
6844 * This function also addresses a similar issue where struct pages are left
6845 * uninitialized because the physical address range is not covered by
6846 * memblock.memory or memblock.reserved. That could happen when memblock
6847 * layout is manually configured via memmap=.
6849 void __init
zero_resv_unavail(void)
6851 phys_addr_t start
, end
;
6853 phys_addr_t next
= 0;
6856 * Loop through unavailable ranges not covered by memblock.memory.
6859 for_each_mem_range(i
, &memblock
.memory
, NULL
,
6860 NUMA_NO_NODE
, MEMBLOCK_NONE
, &start
, &end
, NULL
) {
6862 pgcnt
+= zero_pfn_range(PFN_DOWN(next
), PFN_UP(start
));
6865 pgcnt
+= zero_pfn_range(PFN_DOWN(next
), max_pfn
);
6868 * Struct pages that do not have backing memory. This could be because
6869 * firmware is using some of this memory, or for some other reasons.
6872 pr_info("Zeroed struct page in unavailable ranges: %lld pages", pgcnt
);
6874 #endif /* !CONFIG_FLAT_NODE_MEM_MAP */
6876 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
6878 #if MAX_NUMNODES > 1
6880 * Figure out the number of possible node ids.
6882 void __init
setup_nr_node_ids(void)
6884 unsigned int highest
;
6886 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
6887 nr_node_ids
= highest
+ 1;
6892 * node_map_pfn_alignment - determine the maximum internode alignment
6894 * This function should be called after node map is populated and sorted.
6895 * It calculates the maximum power of two alignment which can distinguish
6898 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
6899 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
6900 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
6901 * shifted, 1GiB is enough and this function will indicate so.
6903 * This is used to test whether pfn -> nid mapping of the chosen memory
6904 * model has fine enough granularity to avoid incorrect mapping for the
6905 * populated node map.
6907 * Return: the determined alignment in pfn's. 0 if there is no alignment
6908 * requirement (single node).
6910 unsigned long __init
node_map_pfn_alignment(void)
6912 unsigned long accl_mask
= 0, last_end
= 0;
6913 unsigned long start
, end
, mask
;
6914 int last_nid
= NUMA_NO_NODE
;
6917 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
6918 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
6925 * Start with a mask granular enough to pin-point to the
6926 * start pfn and tick off bits one-by-one until it becomes
6927 * too coarse to separate the current node from the last.
6929 mask
= ~((1 << __ffs(start
)) - 1);
6930 while (mask
&& last_end
<= (start
& (mask
<< 1)))
6933 /* accumulate all internode masks */
6937 /* convert mask to number of pages */
6938 return ~accl_mask
+ 1;
6941 /* Find the lowest pfn for a node */
6942 static unsigned long __init
find_min_pfn_for_node(int nid
)
6944 unsigned long min_pfn
= ULONG_MAX
;
6945 unsigned long start_pfn
;
6948 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
6949 min_pfn
= min(min_pfn
, start_pfn
);
6951 if (min_pfn
== ULONG_MAX
) {
6952 pr_warn("Could not find start_pfn for node %d\n", nid
);
6960 * find_min_pfn_with_active_regions - Find the minimum PFN registered
6962 * Return: the minimum PFN based on information provided via
6963 * memblock_set_node().
6965 unsigned long __init
find_min_pfn_with_active_regions(void)
6967 return find_min_pfn_for_node(MAX_NUMNODES
);
6971 * early_calculate_totalpages()
6972 * Sum pages in active regions for movable zone.
6973 * Populate N_MEMORY for calculating usable_nodes.
6975 static unsigned long __init
early_calculate_totalpages(void)
6977 unsigned long totalpages
= 0;
6978 unsigned long start_pfn
, end_pfn
;
6981 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
6982 unsigned long pages
= end_pfn
- start_pfn
;
6984 totalpages
+= pages
;
6986 node_set_state(nid
, N_MEMORY
);
6992 * Find the PFN the Movable zone begins in each node. Kernel memory
6993 * is spread evenly between nodes as long as the nodes have enough
6994 * memory. When they don't, some nodes will have more kernelcore than
6997 static void __init
find_zone_movable_pfns_for_nodes(void)
7000 unsigned long usable_startpfn
;
7001 unsigned long kernelcore_node
, kernelcore_remaining
;
7002 /* save the state before borrow the nodemask */
7003 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
7004 unsigned long totalpages
= early_calculate_totalpages();
7005 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
7006 struct memblock_region
*r
;
7008 /* Need to find movable_zone earlier when movable_node is specified. */
7009 find_usable_zone_for_movable();
7012 * If movable_node is specified, ignore kernelcore and movablecore
7015 if (movable_node_is_enabled()) {
7016 for_each_memblock(memory
, r
) {
7017 if (!memblock_is_hotpluggable(r
))
7022 usable_startpfn
= PFN_DOWN(r
->base
);
7023 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
7024 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
7032 * If kernelcore=mirror is specified, ignore movablecore option
7034 if (mirrored_kernelcore
) {
7035 bool mem_below_4gb_not_mirrored
= false;
7037 for_each_memblock(memory
, r
) {
7038 if (memblock_is_mirror(r
))
7043 usable_startpfn
= memblock_region_memory_base_pfn(r
);
7045 if (usable_startpfn
< 0x100000) {
7046 mem_below_4gb_not_mirrored
= true;
7050 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
7051 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
7055 if (mem_below_4gb_not_mirrored
)
7056 pr_warn("This configuration results in unmirrored kernel memory.");
7062 * If kernelcore=nn% or movablecore=nn% was specified, calculate the
7063 * amount of necessary memory.
7065 if (required_kernelcore_percent
)
7066 required_kernelcore
= (totalpages
* 100 * required_kernelcore_percent
) /
7068 if (required_movablecore_percent
)
7069 required_movablecore
= (totalpages
* 100 * required_movablecore_percent
) /
7073 * If movablecore= was specified, calculate what size of
7074 * kernelcore that corresponds so that memory usable for
7075 * any allocation type is evenly spread. If both kernelcore
7076 * and movablecore are specified, then the value of kernelcore
7077 * will be used for required_kernelcore if it's greater than
7078 * what movablecore would have allowed.
7080 if (required_movablecore
) {
7081 unsigned long corepages
;
7084 * Round-up so that ZONE_MOVABLE is at least as large as what
7085 * was requested by the user
7087 required_movablecore
=
7088 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
7089 required_movablecore
= min(totalpages
, required_movablecore
);
7090 corepages
= totalpages
- required_movablecore
;
7092 required_kernelcore
= max(required_kernelcore
, corepages
);
7096 * If kernelcore was not specified or kernelcore size is larger
7097 * than totalpages, there is no ZONE_MOVABLE.
7099 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
7102 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
7103 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
7106 /* Spread kernelcore memory as evenly as possible throughout nodes */
7107 kernelcore_node
= required_kernelcore
/ usable_nodes
;
7108 for_each_node_state(nid
, N_MEMORY
) {
7109 unsigned long start_pfn
, end_pfn
;
7112 * Recalculate kernelcore_node if the division per node
7113 * now exceeds what is necessary to satisfy the requested
7114 * amount of memory for the kernel
7116 if (required_kernelcore
< kernelcore_node
)
7117 kernelcore_node
= required_kernelcore
/ usable_nodes
;
7120 * As the map is walked, we track how much memory is usable
7121 * by the kernel using kernelcore_remaining. When it is
7122 * 0, the rest of the node is usable by ZONE_MOVABLE
7124 kernelcore_remaining
= kernelcore_node
;
7126 /* Go through each range of PFNs within this node */
7127 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
7128 unsigned long size_pages
;
7130 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
7131 if (start_pfn
>= end_pfn
)
7134 /* Account for what is only usable for kernelcore */
7135 if (start_pfn
< usable_startpfn
) {
7136 unsigned long kernel_pages
;
7137 kernel_pages
= min(end_pfn
, usable_startpfn
)
7140 kernelcore_remaining
-= min(kernel_pages
,
7141 kernelcore_remaining
);
7142 required_kernelcore
-= min(kernel_pages
,
7143 required_kernelcore
);
7145 /* Continue if range is now fully accounted */
7146 if (end_pfn
<= usable_startpfn
) {
7149 * Push zone_movable_pfn to the end so
7150 * that if we have to rebalance
7151 * kernelcore across nodes, we will
7152 * not double account here
7154 zone_movable_pfn
[nid
] = end_pfn
;
7157 start_pfn
= usable_startpfn
;
7161 * The usable PFN range for ZONE_MOVABLE is from
7162 * start_pfn->end_pfn. Calculate size_pages as the
7163 * number of pages used as kernelcore
7165 size_pages
= end_pfn
- start_pfn
;
7166 if (size_pages
> kernelcore_remaining
)
7167 size_pages
= kernelcore_remaining
;
7168 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
7171 * Some kernelcore has been met, update counts and
7172 * break if the kernelcore for this node has been
7175 required_kernelcore
-= min(required_kernelcore
,
7177 kernelcore_remaining
-= size_pages
;
7178 if (!kernelcore_remaining
)
7184 * If there is still required_kernelcore, we do another pass with one
7185 * less node in the count. This will push zone_movable_pfn[nid] further
7186 * along on the nodes that still have memory until kernelcore is
7190 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
7194 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
7195 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
7196 zone_movable_pfn
[nid
] =
7197 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
7200 /* restore the node_state */
7201 node_states
[N_MEMORY
] = saved_node_state
;
7204 /* Any regular or high memory on that node ? */
7205 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
7207 enum zone_type zone_type
;
7209 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
7210 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
7211 if (populated_zone(zone
)) {
7212 if (IS_ENABLED(CONFIG_HIGHMEM
))
7213 node_set_state(nid
, N_HIGH_MEMORY
);
7214 if (zone_type
<= ZONE_NORMAL
)
7215 node_set_state(nid
, N_NORMAL_MEMORY
);
7222 * free_area_init_nodes - Initialise all pg_data_t and zone data
7223 * @max_zone_pfn: an array of max PFNs for each zone
7225 * This will call free_area_init_node() for each active node in the system.
7226 * Using the page ranges provided by memblock_set_node(), the size of each
7227 * zone in each node and their holes is calculated. If the maximum PFN
7228 * between two adjacent zones match, it is assumed that the zone is empty.
7229 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
7230 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
7231 * starts where the previous one ended. For example, ZONE_DMA32 starts
7232 * at arch_max_dma_pfn.
7234 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
7236 unsigned long start_pfn
, end_pfn
;
7239 /* Record where the zone boundaries are */
7240 memset(arch_zone_lowest_possible_pfn
, 0,
7241 sizeof(arch_zone_lowest_possible_pfn
));
7242 memset(arch_zone_highest_possible_pfn
, 0,
7243 sizeof(arch_zone_highest_possible_pfn
));
7245 start_pfn
= find_min_pfn_with_active_regions();
7247 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
7248 if (i
== ZONE_MOVABLE
)
7251 end_pfn
= max(max_zone_pfn
[i
], start_pfn
);
7252 arch_zone_lowest_possible_pfn
[i
] = start_pfn
;
7253 arch_zone_highest_possible_pfn
[i
] = end_pfn
;
7255 start_pfn
= end_pfn
;
7258 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
7259 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
7260 find_zone_movable_pfns_for_nodes();
7262 /* Print out the zone ranges */
7263 pr_info("Zone ranges:\n");
7264 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
7265 if (i
== ZONE_MOVABLE
)
7267 pr_info(" %-8s ", zone_names
[i
]);
7268 if (arch_zone_lowest_possible_pfn
[i
] ==
7269 arch_zone_highest_possible_pfn
[i
])
7272 pr_cont("[mem %#018Lx-%#018Lx]\n",
7273 (u64
)arch_zone_lowest_possible_pfn
[i
]
7275 ((u64
)arch_zone_highest_possible_pfn
[i
]
7276 << PAGE_SHIFT
) - 1);
7279 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
7280 pr_info("Movable zone start for each node\n");
7281 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
7282 if (zone_movable_pfn
[i
])
7283 pr_info(" Node %d: %#018Lx\n", i
,
7284 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
7287 /* Print out the early node map */
7288 pr_info("Early memory node ranges\n");
7289 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
7290 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
7291 (u64
)start_pfn
<< PAGE_SHIFT
,
7292 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
7294 /* Initialise every node */
7295 mminit_verify_pageflags_layout();
7296 setup_nr_node_ids();
7297 zero_resv_unavail();
7298 for_each_online_node(nid
) {
7299 pg_data_t
*pgdat
= NODE_DATA(nid
);
7300 free_area_init_node(nid
, NULL
,
7301 find_min_pfn_for_node(nid
), NULL
);
7303 /* Any memory on that node */
7304 if (pgdat
->node_present_pages
)
7305 node_set_state(nid
, N_MEMORY
);
7306 check_for_memory(pgdat
, nid
);
7310 static int __init
cmdline_parse_core(char *p
, unsigned long *core
,
7311 unsigned long *percent
)
7313 unsigned long long coremem
;
7319 /* Value may be a percentage of total memory, otherwise bytes */
7320 coremem
= simple_strtoull(p
, &endptr
, 0);
7321 if (*endptr
== '%') {
7322 /* Paranoid check for percent values greater than 100 */
7323 WARN_ON(coremem
> 100);
7327 coremem
= memparse(p
, &p
);
7328 /* Paranoid check that UL is enough for the coremem value */
7329 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
7331 *core
= coremem
>> PAGE_SHIFT
;
7338 * kernelcore=size sets the amount of memory for use for allocations that
7339 * cannot be reclaimed or migrated.
7341 static int __init
cmdline_parse_kernelcore(char *p
)
7343 /* parse kernelcore=mirror */
7344 if (parse_option_str(p
, "mirror")) {
7345 mirrored_kernelcore
= true;
7349 return cmdline_parse_core(p
, &required_kernelcore
,
7350 &required_kernelcore_percent
);
7354 * movablecore=size sets the amount of memory for use for allocations that
7355 * can be reclaimed or migrated.
7357 static int __init
cmdline_parse_movablecore(char *p
)
7359 return cmdline_parse_core(p
, &required_movablecore
,
7360 &required_movablecore_percent
);
7363 early_param("kernelcore", cmdline_parse_kernelcore
);
7364 early_param("movablecore", cmdline_parse_movablecore
);
7366 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
7368 void adjust_managed_page_count(struct page
*page
, long count
)
7370 atomic_long_add(count
, &page_zone(page
)->managed_pages
);
7371 totalram_pages_add(count
);
7372 #ifdef CONFIG_HIGHMEM
7373 if (PageHighMem(page
))
7374 totalhigh_pages_add(count
);
7377 EXPORT_SYMBOL(adjust_managed_page_count
);
7379 unsigned long free_reserved_area(void *start
, void *end
, int poison
, const char *s
)
7382 unsigned long pages
= 0;
7384 start
= (void *)PAGE_ALIGN((unsigned long)start
);
7385 end
= (void *)((unsigned long)end
& PAGE_MASK
);
7386 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
7387 struct page
*page
= virt_to_page(pos
);
7388 void *direct_map_addr
;
7391 * 'direct_map_addr' might be different from 'pos'
7392 * because some architectures' virt_to_page()
7393 * work with aliases. Getting the direct map
7394 * address ensures that we get a _writeable_
7395 * alias for the memset().
7397 direct_map_addr
= page_address(page
);
7398 if ((unsigned int)poison
<= 0xFF)
7399 memset(direct_map_addr
, poison
, PAGE_SIZE
);
7401 free_reserved_page(page
);
7405 pr_info("Freeing %s memory: %ldK\n",
7406 s
, pages
<< (PAGE_SHIFT
- 10));
7411 #ifdef CONFIG_HIGHMEM
7412 void free_highmem_page(struct page
*page
)
7414 __free_reserved_page(page
);
7415 totalram_pages_inc();
7416 atomic_long_inc(&page_zone(page
)->managed_pages
);
7417 totalhigh_pages_inc();
7422 void __init
mem_init_print_info(const char *str
)
7424 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
7425 unsigned long init_code_size
, init_data_size
;
7427 physpages
= get_num_physpages();
7428 codesize
= _etext
- _stext
;
7429 datasize
= _edata
- _sdata
;
7430 rosize
= __end_rodata
- __start_rodata
;
7431 bss_size
= __bss_stop
- __bss_start
;
7432 init_data_size
= __init_end
- __init_begin
;
7433 init_code_size
= _einittext
- _sinittext
;
7436 * Detect special cases and adjust section sizes accordingly:
7437 * 1) .init.* may be embedded into .data sections
7438 * 2) .init.text.* may be out of [__init_begin, __init_end],
7439 * please refer to arch/tile/kernel/vmlinux.lds.S.
7440 * 3) .rodata.* may be embedded into .text or .data sections.
7442 #define adj_init_size(start, end, size, pos, adj) \
7444 if (start <= pos && pos < end && size > adj) \
7448 adj_init_size(__init_begin
, __init_end
, init_data_size
,
7449 _sinittext
, init_code_size
);
7450 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
7451 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
7452 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
7453 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
7455 #undef adj_init_size
7457 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
7458 #ifdef CONFIG_HIGHMEM
7462 nr_free_pages() << (PAGE_SHIFT
- 10),
7463 physpages
<< (PAGE_SHIFT
- 10),
7464 codesize
>> 10, datasize
>> 10, rosize
>> 10,
7465 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
7466 (physpages
- totalram_pages() - totalcma_pages
) << (PAGE_SHIFT
- 10),
7467 totalcma_pages
<< (PAGE_SHIFT
- 10),
7468 #ifdef CONFIG_HIGHMEM
7469 totalhigh_pages() << (PAGE_SHIFT
- 10),
7471 str
? ", " : "", str
? str
: "");
7475 * set_dma_reserve - set the specified number of pages reserved in the first zone
7476 * @new_dma_reserve: The number of pages to mark reserved
7478 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
7479 * In the DMA zone, a significant percentage may be consumed by kernel image
7480 * and other unfreeable allocations which can skew the watermarks badly. This
7481 * function may optionally be used to account for unfreeable pages in the
7482 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
7483 * smaller per-cpu batchsize.
7485 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
7487 dma_reserve
= new_dma_reserve
;
7490 void __init
free_area_init(unsigned long *zones_size
)
7492 zero_resv_unavail();
7493 free_area_init_node(0, zones_size
,
7494 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
7497 static int page_alloc_cpu_dead(unsigned int cpu
)
7500 lru_add_drain_cpu(cpu
);
7504 * Spill the event counters of the dead processor
7505 * into the current processors event counters.
7506 * This artificially elevates the count of the current
7509 vm_events_fold_cpu(cpu
);
7512 * Zero the differential counters of the dead processor
7513 * so that the vm statistics are consistent.
7515 * This is only okay since the processor is dead and cannot
7516 * race with what we are doing.
7518 cpu_vm_stats_fold(cpu
);
7522 void __init
page_alloc_init(void)
7526 ret
= cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC_DEAD
,
7527 "mm/page_alloc:dead", NULL
,
7528 page_alloc_cpu_dead
);
7533 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
7534 * or min_free_kbytes changes.
7536 static void calculate_totalreserve_pages(void)
7538 struct pglist_data
*pgdat
;
7539 unsigned long reserve_pages
= 0;
7540 enum zone_type i
, j
;
7542 for_each_online_pgdat(pgdat
) {
7544 pgdat
->totalreserve_pages
= 0;
7546 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
7547 struct zone
*zone
= pgdat
->node_zones
+ i
;
7549 unsigned long managed_pages
= zone_managed_pages(zone
);
7551 /* Find valid and maximum lowmem_reserve in the zone */
7552 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
7553 if (zone
->lowmem_reserve
[j
] > max
)
7554 max
= zone
->lowmem_reserve
[j
];
7557 /* we treat the high watermark as reserved pages. */
7558 max
+= high_wmark_pages(zone
);
7560 if (max
> managed_pages
)
7561 max
= managed_pages
;
7563 pgdat
->totalreserve_pages
+= max
;
7565 reserve_pages
+= max
;
7568 totalreserve_pages
= reserve_pages
;
7572 * setup_per_zone_lowmem_reserve - called whenever
7573 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
7574 * has a correct pages reserved value, so an adequate number of
7575 * pages are left in the zone after a successful __alloc_pages().
7577 static void setup_per_zone_lowmem_reserve(void)
7579 struct pglist_data
*pgdat
;
7580 enum zone_type j
, idx
;
7582 for_each_online_pgdat(pgdat
) {
7583 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
7584 struct zone
*zone
= pgdat
->node_zones
+ j
;
7585 unsigned long managed_pages
= zone_managed_pages(zone
);
7587 zone
->lowmem_reserve
[j
] = 0;
7591 struct zone
*lower_zone
;
7594 lower_zone
= pgdat
->node_zones
+ idx
;
7596 if (sysctl_lowmem_reserve_ratio
[idx
] < 1) {
7597 sysctl_lowmem_reserve_ratio
[idx
] = 0;
7598 lower_zone
->lowmem_reserve
[j
] = 0;
7600 lower_zone
->lowmem_reserve
[j
] =
7601 managed_pages
/ sysctl_lowmem_reserve_ratio
[idx
];
7603 managed_pages
+= zone_managed_pages(lower_zone
);
7608 /* update totalreserve_pages */
7609 calculate_totalreserve_pages();
7612 static void __setup_per_zone_wmarks(void)
7614 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
7615 unsigned long lowmem_pages
= 0;
7617 unsigned long flags
;
7619 /* Calculate total number of !ZONE_HIGHMEM pages */
7620 for_each_zone(zone
) {
7621 if (!is_highmem(zone
))
7622 lowmem_pages
+= zone_managed_pages(zone
);
7625 for_each_zone(zone
) {
7628 spin_lock_irqsave(&zone
->lock
, flags
);
7629 tmp
= (u64
)pages_min
* zone_managed_pages(zone
);
7630 do_div(tmp
, lowmem_pages
);
7631 if (is_highmem(zone
)) {
7633 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
7634 * need highmem pages, so cap pages_min to a small
7637 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
7638 * deltas control async page reclaim, and so should
7639 * not be capped for highmem.
7641 unsigned long min_pages
;
7643 min_pages
= zone_managed_pages(zone
) / 1024;
7644 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
7645 zone
->_watermark
[WMARK_MIN
] = min_pages
;
7648 * If it's a lowmem zone, reserve a number of pages
7649 * proportionate to the zone's size.
7651 zone
->_watermark
[WMARK_MIN
] = tmp
;
7655 * Set the kswapd watermarks distance according to the
7656 * scale factor in proportion to available memory, but
7657 * ensure a minimum size on small systems.
7659 tmp
= max_t(u64
, tmp
>> 2,
7660 mult_frac(zone_managed_pages(zone
),
7661 watermark_scale_factor
, 10000));
7663 zone
->_watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + tmp
;
7664 zone
->_watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + tmp
* 2;
7665 zone
->watermark_boost
= 0;
7667 spin_unlock_irqrestore(&zone
->lock
, flags
);
7670 /* update totalreserve_pages */
7671 calculate_totalreserve_pages();
7675 * setup_per_zone_wmarks - called when min_free_kbytes changes
7676 * or when memory is hot-{added|removed}
7678 * Ensures that the watermark[min,low,high] values for each zone are set
7679 * correctly with respect to min_free_kbytes.
7681 void setup_per_zone_wmarks(void)
7683 static DEFINE_SPINLOCK(lock
);
7686 __setup_per_zone_wmarks();
7691 * Initialise min_free_kbytes.
7693 * For small machines we want it small (128k min). For large machines
7694 * we want it large (64MB max). But it is not linear, because network
7695 * bandwidth does not increase linearly with machine size. We use
7697 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
7698 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
7714 int __meminit
init_per_zone_wmark_min(void)
7716 unsigned long lowmem_kbytes
;
7717 int new_min_free_kbytes
;
7719 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
7720 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
7722 if (new_min_free_kbytes
> user_min_free_kbytes
) {
7723 min_free_kbytes
= new_min_free_kbytes
;
7724 if (min_free_kbytes
< 128)
7725 min_free_kbytes
= 128;
7726 if (min_free_kbytes
> 65536)
7727 min_free_kbytes
= 65536;
7729 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
7730 new_min_free_kbytes
, user_min_free_kbytes
);
7732 setup_per_zone_wmarks();
7733 refresh_zone_stat_thresholds();
7734 setup_per_zone_lowmem_reserve();
7737 setup_min_unmapped_ratio();
7738 setup_min_slab_ratio();
7743 core_initcall(init_per_zone_wmark_min
)
7746 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
7747 * that we can call two helper functions whenever min_free_kbytes
7750 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
7751 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7755 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7760 user_min_free_kbytes
= min_free_kbytes
;
7761 setup_per_zone_wmarks();
7766 int watermark_boost_factor_sysctl_handler(struct ctl_table
*table
, int write
,
7767 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7771 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7778 int watermark_scale_factor_sysctl_handler(struct ctl_table
*table
, int write
,
7779 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7783 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7788 setup_per_zone_wmarks();
7794 static void setup_min_unmapped_ratio(void)
7799 for_each_online_pgdat(pgdat
)
7800 pgdat
->min_unmapped_pages
= 0;
7803 zone
->zone_pgdat
->min_unmapped_pages
+= (zone_managed_pages(zone
) *
7804 sysctl_min_unmapped_ratio
) / 100;
7808 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7809 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7813 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7817 setup_min_unmapped_ratio();
7822 static void setup_min_slab_ratio(void)
7827 for_each_online_pgdat(pgdat
)
7828 pgdat
->min_slab_pages
= 0;
7831 zone
->zone_pgdat
->min_slab_pages
+= (zone_managed_pages(zone
) *
7832 sysctl_min_slab_ratio
) / 100;
7835 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7836 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7840 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7844 setup_min_slab_ratio();
7851 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
7852 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
7853 * whenever sysctl_lowmem_reserve_ratio changes.
7855 * The reserve ratio obviously has absolutely no relation with the
7856 * minimum watermarks. The lowmem reserve ratio can only make sense
7857 * if in function of the boot time zone sizes.
7859 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
7860 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7862 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7863 setup_per_zone_lowmem_reserve();
7868 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
7869 * cpu. It is the fraction of total pages in each zone that a hot per cpu
7870 * pagelist can have before it gets flushed back to buddy allocator.
7872 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
7873 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
7876 int old_percpu_pagelist_fraction
;
7879 mutex_lock(&pcp_batch_high_lock
);
7880 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
7882 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
7883 if (!write
|| ret
< 0)
7886 /* Sanity checking to avoid pcp imbalance */
7887 if (percpu_pagelist_fraction
&&
7888 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
7889 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
7895 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
7898 for_each_populated_zone(zone
) {
7901 for_each_possible_cpu(cpu
)
7902 pageset_set_high_and_batch(zone
,
7903 per_cpu_ptr(zone
->pageset
, cpu
));
7906 mutex_unlock(&pcp_batch_high_lock
);
7911 int hashdist
= HASHDIST_DEFAULT
;
7913 static int __init
set_hashdist(char *str
)
7917 hashdist
= simple_strtoul(str
, &str
, 0);
7920 __setup("hashdist=", set_hashdist
);
7923 #ifndef __HAVE_ARCH_RESERVED_KERNEL_PAGES
7925 * Returns the number of pages that arch has reserved but
7926 * is not known to alloc_large_system_hash().
7928 static unsigned long __init
arch_reserved_kernel_pages(void)
7935 * Adaptive scale is meant to reduce sizes of hash tables on large memory
7936 * machines. As memory size is increased the scale is also increased but at
7937 * slower pace. Starting from ADAPT_SCALE_BASE (64G), every time memory
7938 * quadruples the scale is increased by one, which means the size of hash table
7939 * only doubles, instead of quadrupling as well.
7940 * Because 32-bit systems cannot have large physical memory, where this scaling
7941 * makes sense, it is disabled on such platforms.
7943 #if __BITS_PER_LONG > 32
7944 #define ADAPT_SCALE_BASE (64ul << 30)
7945 #define ADAPT_SCALE_SHIFT 2
7946 #define ADAPT_SCALE_NPAGES (ADAPT_SCALE_BASE >> PAGE_SHIFT)
7950 * allocate a large system hash table from bootmem
7951 * - it is assumed that the hash table must contain an exact power-of-2
7952 * quantity of entries
7953 * - limit is the number of hash buckets, not the total allocation size
7955 void *__init
alloc_large_system_hash(const char *tablename
,
7956 unsigned long bucketsize
,
7957 unsigned long numentries
,
7960 unsigned int *_hash_shift
,
7961 unsigned int *_hash_mask
,
7962 unsigned long low_limit
,
7963 unsigned long high_limit
)
7965 unsigned long long max
= high_limit
;
7966 unsigned long log2qty
, size
;
7970 /* allow the kernel cmdline to have a say */
7972 /* round applicable memory size up to nearest megabyte */
7973 numentries
= nr_kernel_pages
;
7974 numentries
-= arch_reserved_kernel_pages();
7976 /* It isn't necessary when PAGE_SIZE >= 1MB */
7977 if (PAGE_SHIFT
< 20)
7978 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
7980 #if __BITS_PER_LONG > 32
7982 unsigned long adapt
;
7984 for (adapt
= ADAPT_SCALE_NPAGES
; adapt
< numentries
;
7985 adapt
<<= ADAPT_SCALE_SHIFT
)
7990 /* limit to 1 bucket per 2^scale bytes of low memory */
7991 if (scale
> PAGE_SHIFT
)
7992 numentries
>>= (scale
- PAGE_SHIFT
);
7994 numentries
<<= (PAGE_SHIFT
- scale
);
7996 /* Make sure we've got at least a 0-order allocation.. */
7997 if (unlikely(flags
& HASH_SMALL
)) {
7998 /* Makes no sense without HASH_EARLY */
7999 WARN_ON(!(flags
& HASH_EARLY
));
8000 if (!(numentries
>> *_hash_shift
)) {
8001 numentries
= 1UL << *_hash_shift
;
8002 BUG_ON(!numentries
);
8004 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
8005 numentries
= PAGE_SIZE
/ bucketsize
;
8007 numentries
= roundup_pow_of_two(numentries
);
8009 /* limit allocation size to 1/16 total memory by default */
8011 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
8012 do_div(max
, bucketsize
);
8014 max
= min(max
, 0x80000000ULL
);
8016 if (numentries
< low_limit
)
8017 numentries
= low_limit
;
8018 if (numentries
> max
)
8021 log2qty
= ilog2(numentries
);
8023 gfp_flags
= (flags
& HASH_ZERO
) ? GFP_ATOMIC
| __GFP_ZERO
: GFP_ATOMIC
;
8025 size
= bucketsize
<< log2qty
;
8026 if (flags
& HASH_EARLY
) {
8027 if (flags
& HASH_ZERO
)
8028 table
= memblock_alloc(size
, SMP_CACHE_BYTES
);
8030 table
= memblock_alloc_raw(size
,
8032 } else if (hashdist
) {
8033 table
= __vmalloc(size
, gfp_flags
, PAGE_KERNEL
);
8036 * If bucketsize is not a power-of-two, we may free
8037 * some pages at the end of hash table which
8038 * alloc_pages_exact() automatically does
8040 if (get_order(size
) < MAX_ORDER
) {
8041 table
= alloc_pages_exact(size
, gfp_flags
);
8042 kmemleak_alloc(table
, size
, 1, gfp_flags
);
8045 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
8048 panic("Failed to allocate %s hash table\n", tablename
);
8050 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
8051 tablename
, 1UL << log2qty
, ilog2(size
) - PAGE_SHIFT
, size
);
8054 *_hash_shift
= log2qty
;
8056 *_hash_mask
= (1 << log2qty
) - 1;
8062 * This function checks whether pageblock includes unmovable pages or not.
8063 * If @count is not zero, it is okay to include less @count unmovable pages
8065 * PageLRU check without isolation or lru_lock could race so that
8066 * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable
8067 * check without lock_page also may miss some movable non-lru pages at
8068 * race condition. So you can't expect this function should be exact.
8070 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
8071 int migratetype
, int flags
)
8073 unsigned long found
;
8074 unsigned long iter
= 0;
8075 unsigned long pfn
= page_to_pfn(page
);
8076 const char *reason
= "unmovable page";
8079 * TODO we could make this much more efficient by not checking every
8080 * page in the range if we know all of them are in MOVABLE_ZONE and
8081 * that the movable zone guarantees that pages are migratable but
8082 * the later is not the case right now unfortunatelly. E.g. movablecore
8083 * can still lead to having bootmem allocations in zone_movable.
8086 if (is_migrate_cma_page(page
)) {
8088 * CMA allocations (alloc_contig_range) really need to mark
8089 * isolate CMA pageblocks even when they are not movable in fact
8090 * so consider them movable here.
8092 if (is_migrate_cma(migratetype
))
8095 reason
= "CMA page";
8099 for (found
= 0; iter
< pageblock_nr_pages
; iter
++) {
8100 unsigned long check
= pfn
+ iter
;
8102 if (!pfn_valid_within(check
))
8105 page
= pfn_to_page(check
);
8107 if (PageReserved(page
))
8111 * If the zone is movable and we have ruled out all reserved
8112 * pages then it should be reasonably safe to assume the rest
8115 if (zone_idx(zone
) == ZONE_MOVABLE
)
8119 * Hugepages are not in LRU lists, but they're movable.
8120 * We need not scan over tail pages because we don't
8121 * handle each tail page individually in migration.
8123 if (PageHuge(page
)) {
8124 struct page
*head
= compound_head(page
);
8125 unsigned int skip_pages
;
8127 if (!hugepage_migration_supported(page_hstate(head
)))
8130 skip_pages
= (1 << compound_order(head
)) - (page
- head
);
8131 iter
+= skip_pages
- 1;
8136 * We can't use page_count without pin a page
8137 * because another CPU can free compound page.
8138 * This check already skips compound tails of THP
8139 * because their page->_refcount is zero at all time.
8141 if (!page_ref_count(page
)) {
8142 if (PageBuddy(page
))
8143 iter
+= (1 << page_order(page
)) - 1;
8148 * The HWPoisoned page may be not in buddy system, and
8149 * page_count() is not 0.
8151 if ((flags
& SKIP_HWPOISON
) && PageHWPoison(page
))
8154 if (__PageMovable(page
))
8160 * If there are RECLAIMABLE pages, we need to check
8161 * it. But now, memory offline itself doesn't call
8162 * shrink_node_slabs() and it still to be fixed.
8165 * If the page is not RAM, page_count()should be 0.
8166 * we don't need more check. This is an _used_ not-movable page.
8168 * The problematic thing here is PG_reserved pages. PG_reserved
8169 * is set to both of a memory hole page and a _used_ kernel
8177 WARN_ON_ONCE(zone_idx(zone
) == ZONE_MOVABLE
);
8178 if (flags
& REPORT_FAILURE
)
8179 dump_page(pfn_to_page(pfn
+ iter
), reason
);
8183 #ifdef CONFIG_CONTIG_ALLOC
8184 static unsigned long pfn_max_align_down(unsigned long pfn
)
8186 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
8187 pageblock_nr_pages
) - 1);
8190 static unsigned long pfn_max_align_up(unsigned long pfn
)
8192 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
8193 pageblock_nr_pages
));
8196 /* [start, end) must belong to a single zone. */
8197 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
8198 unsigned long start
, unsigned long end
)
8200 /* This function is based on compact_zone() from compaction.c. */
8201 unsigned long nr_reclaimed
;
8202 unsigned long pfn
= start
;
8203 unsigned int tries
= 0;
8208 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
8209 if (fatal_signal_pending(current
)) {
8214 if (list_empty(&cc
->migratepages
)) {
8215 cc
->nr_migratepages
= 0;
8216 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
8222 } else if (++tries
== 5) {
8223 ret
= ret
< 0 ? ret
: -EBUSY
;
8227 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
8229 cc
->nr_migratepages
-= nr_reclaimed
;
8231 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
8232 NULL
, 0, cc
->mode
, MR_CONTIG_RANGE
);
8235 putback_movable_pages(&cc
->migratepages
);
8242 * alloc_contig_range() -- tries to allocate given range of pages
8243 * @start: start PFN to allocate
8244 * @end: one-past-the-last PFN to allocate
8245 * @migratetype: migratetype of the underlaying pageblocks (either
8246 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
8247 * in range must have the same migratetype and it must
8248 * be either of the two.
8249 * @gfp_mask: GFP mask to use during compaction
8251 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
8252 * aligned. The PFN range must belong to a single zone.
8254 * The first thing this routine does is attempt to MIGRATE_ISOLATE all
8255 * pageblocks in the range. Once isolated, the pageblocks should not
8256 * be modified by others.
8258 * Return: zero on success or negative error code. On success all
8259 * pages which PFN is in [start, end) are allocated for the caller and
8260 * need to be freed with free_contig_range().
8262 int alloc_contig_range(unsigned long start
, unsigned long end
,
8263 unsigned migratetype
, gfp_t gfp_mask
)
8265 unsigned long outer_start
, outer_end
;
8269 struct compact_control cc
= {
8270 .nr_migratepages
= 0,
8272 .zone
= page_zone(pfn_to_page(start
)),
8273 .mode
= MIGRATE_SYNC
,
8274 .ignore_skip_hint
= true,
8275 .no_set_skip_hint
= true,
8276 .gfp_mask
= current_gfp_context(gfp_mask
),
8278 INIT_LIST_HEAD(&cc
.migratepages
);
8281 * What we do here is we mark all pageblocks in range as
8282 * MIGRATE_ISOLATE. Because pageblock and max order pages may
8283 * have different sizes, and due to the way page allocator
8284 * work, we align the range to biggest of the two pages so
8285 * that page allocator won't try to merge buddies from
8286 * different pageblocks and change MIGRATE_ISOLATE to some
8287 * other migration type.
8289 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
8290 * migrate the pages from an unaligned range (ie. pages that
8291 * we are interested in). This will put all the pages in
8292 * range back to page allocator as MIGRATE_ISOLATE.
8294 * When this is done, we take the pages in range from page
8295 * allocator removing them from the buddy system. This way
8296 * page allocator will never consider using them.
8298 * This lets us mark the pageblocks back as
8299 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
8300 * aligned range but not in the unaligned, original range are
8301 * put back to page allocator so that buddy can use them.
8304 ret
= start_isolate_page_range(pfn_max_align_down(start
),
8305 pfn_max_align_up(end
), migratetype
, 0);
8310 * In case of -EBUSY, we'd like to know which page causes problem.
8311 * So, just fall through. test_pages_isolated() has a tracepoint
8312 * which will report the busy page.
8314 * It is possible that busy pages could become available before
8315 * the call to test_pages_isolated, and the range will actually be
8316 * allocated. So, if we fall through be sure to clear ret so that
8317 * -EBUSY is not accidentally used or returned to caller.
8319 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
8320 if (ret
&& ret
!= -EBUSY
)
8325 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
8326 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
8327 * more, all pages in [start, end) are free in page allocator.
8328 * What we are going to do is to allocate all pages from
8329 * [start, end) (that is remove them from page allocator).
8331 * The only problem is that pages at the beginning and at the
8332 * end of interesting range may be not aligned with pages that
8333 * page allocator holds, ie. they can be part of higher order
8334 * pages. Because of this, we reserve the bigger range and
8335 * once this is done free the pages we are not interested in.
8337 * We don't have to hold zone->lock here because the pages are
8338 * isolated thus they won't get removed from buddy.
8341 lru_add_drain_all();
8344 outer_start
= start
;
8345 while (!PageBuddy(pfn_to_page(outer_start
))) {
8346 if (++order
>= MAX_ORDER
) {
8347 outer_start
= start
;
8350 outer_start
&= ~0UL << order
;
8353 if (outer_start
!= start
) {
8354 order
= page_order(pfn_to_page(outer_start
));
8357 * outer_start page could be small order buddy page and
8358 * it doesn't include start page. Adjust outer_start
8359 * in this case to report failed page properly
8360 * on tracepoint in test_pages_isolated()
8362 if (outer_start
+ (1UL << order
) <= start
)
8363 outer_start
= start
;
8366 /* Make sure the range is really isolated. */
8367 if (test_pages_isolated(outer_start
, end
, false)) {
8368 pr_info_ratelimited("%s: [%lx, %lx) PFNs busy\n",
8369 __func__
, outer_start
, end
);
8374 /* Grab isolated pages from freelists. */
8375 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
8381 /* Free head and tail (if any) */
8382 if (start
!= outer_start
)
8383 free_contig_range(outer_start
, start
- outer_start
);
8384 if (end
!= outer_end
)
8385 free_contig_range(end
, outer_end
- end
);
8388 undo_isolate_page_range(pfn_max_align_down(start
),
8389 pfn_max_align_up(end
), migratetype
);
8392 #endif /* CONFIG_CONTIG_ALLOC */
8394 void free_contig_range(unsigned long pfn
, unsigned int nr_pages
)
8396 unsigned int count
= 0;
8398 for (; nr_pages
--; pfn
++) {
8399 struct page
*page
= pfn_to_page(pfn
);
8401 count
+= page_count(page
) != 1;
8404 WARN(count
!= 0, "%d pages are still in use!\n", count
);
8407 #ifdef CONFIG_MEMORY_HOTPLUG
8409 * The zone indicated has a new number of managed_pages; batch sizes and percpu
8410 * page high values need to be recalulated.
8412 void __meminit
zone_pcp_update(struct zone
*zone
)
8415 mutex_lock(&pcp_batch_high_lock
);
8416 for_each_possible_cpu(cpu
)
8417 pageset_set_high_and_batch(zone
,
8418 per_cpu_ptr(zone
->pageset
, cpu
));
8419 mutex_unlock(&pcp_batch_high_lock
);
8423 void zone_pcp_reset(struct zone
*zone
)
8425 unsigned long flags
;
8427 struct per_cpu_pageset
*pset
;
8429 /* avoid races with drain_pages() */
8430 local_irq_save(flags
);
8431 if (zone
->pageset
!= &boot_pageset
) {
8432 for_each_online_cpu(cpu
) {
8433 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
8434 drain_zonestat(zone
, pset
);
8436 free_percpu(zone
->pageset
);
8437 zone
->pageset
= &boot_pageset
;
8439 local_irq_restore(flags
);
8442 #ifdef CONFIG_MEMORY_HOTREMOVE
8444 * All pages in the range must be in a single zone and isolated
8445 * before calling this.
8448 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
8452 unsigned int order
, i
;
8454 unsigned long flags
;
8455 unsigned long offlined_pages
= 0;
8457 /* find the first valid pfn */
8458 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
8462 return offlined_pages
;
8464 offline_mem_sections(pfn
, end_pfn
);
8465 zone
= page_zone(pfn_to_page(pfn
));
8466 spin_lock_irqsave(&zone
->lock
, flags
);
8468 while (pfn
< end_pfn
) {
8469 if (!pfn_valid(pfn
)) {
8473 page
= pfn_to_page(pfn
);
8475 * The HWPoisoned page may be not in buddy system, and
8476 * page_count() is not 0.
8478 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
8480 SetPageReserved(page
);
8485 BUG_ON(page_count(page
));
8486 BUG_ON(!PageBuddy(page
));
8487 order
= page_order(page
);
8488 offlined_pages
+= 1 << order
;
8489 #ifdef CONFIG_DEBUG_VM
8490 pr_info("remove from free list %lx %d %lx\n",
8491 pfn
, 1 << order
, end_pfn
);
8493 del_page_from_free_area(page
, &zone
->free_area
[order
]);
8494 for (i
= 0; i
< (1 << order
); i
++)
8495 SetPageReserved((page
+i
));
8496 pfn
+= (1 << order
);
8498 spin_unlock_irqrestore(&zone
->lock
, flags
);
8500 return offlined_pages
;
8504 bool is_free_buddy_page(struct page
*page
)
8506 struct zone
*zone
= page_zone(page
);
8507 unsigned long pfn
= page_to_pfn(page
);
8508 unsigned long flags
;
8511 spin_lock_irqsave(&zone
->lock
, flags
);
8512 for (order
= 0; order
< MAX_ORDER
; order
++) {
8513 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
8515 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
8518 spin_unlock_irqrestore(&zone
->lock
, flags
);
8520 return order
< MAX_ORDER
;
8523 #ifdef CONFIG_MEMORY_FAILURE
8525 * Set PG_hwpoison flag if a given page is confirmed to be a free page. This
8526 * test is performed under the zone lock to prevent a race against page
8529 bool set_hwpoison_free_buddy_page(struct page
*page
)
8531 struct zone
*zone
= page_zone(page
);
8532 unsigned long pfn
= page_to_pfn(page
);
8533 unsigned long flags
;
8535 bool hwpoisoned
= false;
8537 spin_lock_irqsave(&zone
->lock
, flags
);
8538 for (order
= 0; order
< MAX_ORDER
; order
++) {
8539 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
8541 if (PageBuddy(page_head
) && page_order(page_head
) >= order
) {
8542 if (!TestSetPageHWPoison(page
))
8547 spin_unlock_irqrestore(&zone
->lock
, flags
);