2 * linux/mm/page_alloc.c
4 * Manages the free list, the system allocates free pages here.
5 * Note that kmalloc() lives in slab.c
7 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
8 * Swap reorganised 29.12.95, Stephen Tweedie
9 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
10 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
11 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
12 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000
13 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
14 * (lots of bits borrowed from Ingo Molnar & Andrew Morton)
17 #include <linux/stddef.h>
19 #include <linux/swap.h>
20 #include <linux/interrupt.h>
21 #include <linux/pagemap.h>
22 #include <linux/jiffies.h>
23 #include <linux/bootmem.h>
24 #include <linux/memblock.h>
25 #include <linux/compiler.h>
26 #include <linux/kernel.h>
27 #include <linux/kmemcheck.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/notifier.h>
37 #include <linux/topology.h>
38 #include <linux/sysctl.h>
39 #include <linux/cpu.h>
40 #include <linux/cpuset.h>
41 #include <linux/memory_hotplug.h>
42 #include <linux/nodemask.h>
43 #include <linux/vmalloc.h>
44 #include <linux/vmstat.h>
45 #include <linux/mempolicy.h>
46 #include <linux/memremap.h>
47 #include <linux/stop_machine.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 <linux/prefetch.h>
59 #include <linux/mm_inline.h>
60 #include <linux/migrate.h>
61 #include <linux/page_ext.h>
62 #include <linux/hugetlb.h>
63 #include <linux/sched/rt.h>
64 #include <linux/page_owner.h>
65 #include <linux/kthread.h>
67 #include <asm/sections.h>
68 #include <asm/tlbflush.h>
69 #include <asm/div64.h>
72 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
73 static DEFINE_MUTEX(pcp_batch_high_lock
);
74 #define MIN_PERCPU_PAGELIST_FRACTION (8)
76 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
77 DEFINE_PER_CPU(int, numa_node
);
78 EXPORT_PER_CPU_SYMBOL(numa_node
);
81 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
83 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
84 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
85 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
86 * defined in <linux/topology.h>.
88 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
89 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
90 int _node_numa_mem_
[MAX_NUMNODES
];
94 * Array of node states.
96 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
97 [N_POSSIBLE
] = NODE_MASK_ALL
,
98 [N_ONLINE
] = { { [0] = 1UL } },
100 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
101 #ifdef CONFIG_HIGHMEM
102 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
104 #ifdef CONFIG_MOVABLE_NODE
105 [N_MEMORY
] = { { [0] = 1UL } },
107 [N_CPU
] = { { [0] = 1UL } },
110 EXPORT_SYMBOL(node_states
);
112 /* Protect totalram_pages and zone->managed_pages */
113 static DEFINE_SPINLOCK(managed_page_count_lock
);
115 unsigned long totalram_pages __read_mostly
;
116 unsigned long totalreserve_pages __read_mostly
;
117 unsigned long totalcma_pages __read_mostly
;
119 int percpu_pagelist_fraction
;
120 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
123 * A cached value of the page's pageblock's migratetype, used when the page is
124 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
125 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
126 * Also the migratetype set in the page does not necessarily match the pcplist
127 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
128 * other index - this ensures that it will be put on the correct CMA freelist.
130 static inline int get_pcppage_migratetype(struct page
*page
)
135 static inline void set_pcppage_migratetype(struct page
*page
, int migratetype
)
137 page
->index
= migratetype
;
140 #ifdef CONFIG_PM_SLEEP
142 * The following functions are used by the suspend/hibernate code to temporarily
143 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
144 * while devices are suspended. To avoid races with the suspend/hibernate code,
145 * they should always be called with pm_mutex held (gfp_allowed_mask also should
146 * only be modified with pm_mutex held, unless the suspend/hibernate code is
147 * guaranteed not to run in parallel with that modification).
150 static gfp_t saved_gfp_mask
;
152 void pm_restore_gfp_mask(void)
154 WARN_ON(!mutex_is_locked(&pm_mutex
));
155 if (saved_gfp_mask
) {
156 gfp_allowed_mask
= saved_gfp_mask
;
161 void pm_restrict_gfp_mask(void)
163 WARN_ON(!mutex_is_locked(&pm_mutex
));
164 WARN_ON(saved_gfp_mask
);
165 saved_gfp_mask
= gfp_allowed_mask
;
166 gfp_allowed_mask
&= ~(__GFP_IO
| __GFP_FS
);
169 bool pm_suspended_storage(void)
171 if ((gfp_allowed_mask
& (__GFP_IO
| __GFP_FS
)) == (__GFP_IO
| __GFP_FS
))
175 #endif /* CONFIG_PM_SLEEP */
177 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
178 unsigned int pageblock_order __read_mostly
;
181 static void __free_pages_ok(struct page
*page
, unsigned int order
);
184 * results with 256, 32 in the lowmem_reserve sysctl:
185 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
186 * 1G machine -> (16M dma, 784M normal, 224M high)
187 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
188 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
189 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
191 * TBD: should special case ZONE_DMA32 machines here - in those we normally
192 * don't need any ZONE_NORMAL reservation
194 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
195 #ifdef CONFIG_ZONE_DMA
198 #ifdef CONFIG_ZONE_DMA32
201 #ifdef CONFIG_HIGHMEM
207 EXPORT_SYMBOL(totalram_pages
);
209 static char * const zone_names
[MAX_NR_ZONES
] = {
210 #ifdef CONFIG_ZONE_DMA
213 #ifdef CONFIG_ZONE_DMA32
217 #ifdef CONFIG_HIGHMEM
221 #ifdef CONFIG_ZONE_DEVICE
226 char * const migratetype_names
[MIGRATE_TYPES
] = {
234 #ifdef CONFIG_MEMORY_ISOLATION
239 compound_page_dtor
* const compound_page_dtors
[] = {
242 #ifdef CONFIG_HUGETLB_PAGE
245 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
250 int min_free_kbytes
= 1024;
251 int user_min_free_kbytes
= -1;
252 int watermark_scale_factor
= 10;
254 static unsigned long __meminitdata nr_kernel_pages
;
255 static unsigned long __meminitdata nr_all_pages
;
256 static unsigned long __meminitdata dma_reserve
;
258 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
259 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
260 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
261 static unsigned long __initdata required_kernelcore
;
262 static unsigned long __initdata required_movablecore
;
263 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
264 static bool mirrored_kernelcore
;
266 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
268 EXPORT_SYMBOL(movable_zone
);
269 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
272 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
273 int nr_online_nodes __read_mostly
= 1;
274 EXPORT_SYMBOL(nr_node_ids
);
275 EXPORT_SYMBOL(nr_online_nodes
);
278 int page_group_by_mobility_disabled __read_mostly
;
280 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
281 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
283 pgdat
->first_deferred_pfn
= ULONG_MAX
;
286 /* Returns true if the struct page for the pfn is uninitialised */
287 static inline bool __meminit
early_page_uninitialised(unsigned long pfn
)
289 if (pfn
>= NODE_DATA(early_pfn_to_nid(pfn
))->first_deferred_pfn
)
295 static inline bool early_page_nid_uninitialised(unsigned long pfn
, int nid
)
297 if (pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
304 * Returns false when the remaining initialisation should be deferred until
305 * later in the boot cycle when it can be parallelised.
307 static inline bool update_defer_init(pg_data_t
*pgdat
,
308 unsigned long pfn
, unsigned long zone_end
,
309 unsigned long *nr_initialised
)
311 unsigned long max_initialise
;
313 /* Always populate low zones for address-contrained allocations */
314 if (zone_end
< pgdat_end_pfn(pgdat
))
317 * Initialise at least 2G of a node but also take into account that
318 * two large system hashes that can take up 1GB for 0.25TB/node.
320 max_initialise
= max(2UL << (30 - PAGE_SHIFT
),
321 (pgdat
->node_spanned_pages
>> 8));
324 if ((*nr_initialised
> max_initialise
) &&
325 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
326 pgdat
->first_deferred_pfn
= pfn
;
333 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
337 static inline bool early_page_uninitialised(unsigned long pfn
)
342 static inline bool early_page_nid_uninitialised(unsigned long pfn
, int nid
)
347 static inline bool update_defer_init(pg_data_t
*pgdat
,
348 unsigned long pfn
, unsigned long zone_end
,
349 unsigned long *nr_initialised
)
356 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
358 if (unlikely(page_group_by_mobility_disabled
&&
359 migratetype
< MIGRATE_PCPTYPES
))
360 migratetype
= MIGRATE_UNMOVABLE
;
362 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
363 PB_migrate
, PB_migrate_end
);
366 #ifdef CONFIG_DEBUG_VM
367 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
371 unsigned long pfn
= page_to_pfn(page
);
372 unsigned long sp
, start_pfn
;
375 seq
= zone_span_seqbegin(zone
);
376 start_pfn
= zone
->zone_start_pfn
;
377 sp
= zone
->spanned_pages
;
378 if (!zone_spans_pfn(zone
, pfn
))
380 } while (zone_span_seqretry(zone
, seq
));
383 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
384 pfn
, zone_to_nid(zone
), zone
->name
,
385 start_pfn
, start_pfn
+ sp
);
390 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
392 if (!pfn_valid_within(page_to_pfn(page
)))
394 if (zone
!= page_zone(page
))
400 * Temporary debugging check for pages not lying within a given zone.
402 static int bad_range(struct zone
*zone
, struct page
*page
)
404 if (page_outside_zone_boundaries(zone
, page
))
406 if (!page_is_consistent(zone
, page
))
412 static inline int bad_range(struct zone
*zone
, struct page
*page
)
418 static void bad_page(struct page
*page
, const char *reason
,
419 unsigned long bad_flags
)
421 static unsigned long resume
;
422 static unsigned long nr_shown
;
423 static unsigned long nr_unshown
;
425 /* Don't complain about poisoned pages */
426 if (PageHWPoison(page
)) {
427 page_mapcount_reset(page
); /* remove PageBuddy */
432 * Allow a burst of 60 reports, then keep quiet for that minute;
433 * or allow a steady drip of one report per second.
435 if (nr_shown
== 60) {
436 if (time_before(jiffies
, resume
)) {
442 "BUG: Bad page state: %lu messages suppressed\n",
449 resume
= jiffies
+ 60 * HZ
;
451 pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
452 current
->comm
, page_to_pfn(page
));
453 __dump_page(page
, reason
);
454 bad_flags
&= page
->flags
;
456 pr_alert("bad because of flags: %#lx(%pGp)\n",
457 bad_flags
, &bad_flags
);
458 dump_page_owner(page
);
463 /* Leave bad fields for debug, except PageBuddy could make trouble */
464 page_mapcount_reset(page
); /* remove PageBuddy */
465 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
469 * Higher-order pages are called "compound pages". They are structured thusly:
471 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
473 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
474 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
476 * The first tail page's ->compound_dtor holds the offset in array of compound
477 * page destructors. See compound_page_dtors.
479 * The first tail page's ->compound_order holds the order of allocation.
480 * This usage means that zero-order pages may not be compound.
483 void free_compound_page(struct page
*page
)
485 __free_pages_ok(page
, compound_order(page
));
488 void prep_compound_page(struct page
*page
, unsigned int order
)
491 int nr_pages
= 1 << order
;
493 set_compound_page_dtor(page
, COMPOUND_PAGE_DTOR
);
494 set_compound_order(page
, order
);
496 for (i
= 1; i
< nr_pages
; i
++) {
497 struct page
*p
= page
+ i
;
498 set_page_count(p
, 0);
499 p
->mapping
= TAIL_MAPPING
;
500 set_compound_head(p
, page
);
502 atomic_set(compound_mapcount_ptr(page
), -1);
505 #ifdef CONFIG_DEBUG_PAGEALLOC
506 unsigned int _debug_guardpage_minorder
;
507 bool _debug_pagealloc_enabled __read_mostly
508 = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT
);
509 EXPORT_SYMBOL(_debug_pagealloc_enabled
);
510 bool _debug_guardpage_enabled __read_mostly
;
512 static int __init
early_debug_pagealloc(char *buf
)
517 if (strcmp(buf
, "on") == 0)
518 _debug_pagealloc_enabled
= true;
520 if (strcmp(buf
, "off") == 0)
521 _debug_pagealloc_enabled
= false;
525 early_param("debug_pagealloc", early_debug_pagealloc
);
527 static bool need_debug_guardpage(void)
529 /* If we don't use debug_pagealloc, we don't need guard page */
530 if (!debug_pagealloc_enabled())
536 static void init_debug_guardpage(void)
538 if (!debug_pagealloc_enabled())
541 _debug_guardpage_enabled
= true;
544 struct page_ext_operations debug_guardpage_ops
= {
545 .need
= need_debug_guardpage
,
546 .init
= init_debug_guardpage
,
549 static int __init
debug_guardpage_minorder_setup(char *buf
)
553 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
554 pr_err("Bad debug_guardpage_minorder value\n");
557 _debug_guardpage_minorder
= res
;
558 pr_info("Setting debug_guardpage_minorder to %lu\n", res
);
561 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
563 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
564 unsigned int order
, int migratetype
)
566 struct page_ext
*page_ext
;
568 if (!debug_guardpage_enabled())
571 page_ext
= lookup_page_ext(page
);
572 __set_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
574 INIT_LIST_HEAD(&page
->lru
);
575 set_page_private(page
, order
);
576 /* Guard pages are not available for any usage */
577 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
580 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
581 unsigned int order
, int migratetype
)
583 struct page_ext
*page_ext
;
585 if (!debug_guardpage_enabled())
588 page_ext
= lookup_page_ext(page
);
589 __clear_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
591 set_page_private(page
, 0);
592 if (!is_migrate_isolate(migratetype
))
593 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
596 struct page_ext_operations debug_guardpage_ops
= { NULL
, };
597 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
598 unsigned int order
, int migratetype
) {}
599 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
600 unsigned int order
, int migratetype
) {}
603 static inline void set_page_order(struct page
*page
, unsigned int order
)
605 set_page_private(page
, order
);
606 __SetPageBuddy(page
);
609 static inline void rmv_page_order(struct page
*page
)
611 __ClearPageBuddy(page
);
612 set_page_private(page
, 0);
616 * This function checks whether a page is free && is the buddy
617 * we can do coalesce a page and its buddy if
618 * (a) the buddy is not in a hole &&
619 * (b) the buddy is in the buddy system &&
620 * (c) a page and its buddy have the same order &&
621 * (d) a page and its buddy are in the same zone.
623 * For recording whether a page is in the buddy system, we set ->_mapcount
624 * PAGE_BUDDY_MAPCOUNT_VALUE.
625 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
626 * serialized by zone->lock.
628 * For recording page's order, we use page_private(page).
630 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
633 if (!pfn_valid_within(page_to_pfn(buddy
)))
636 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
637 if (page_zone_id(page
) != page_zone_id(buddy
))
640 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
645 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
647 * zone check is done late to avoid uselessly
648 * calculating zone/node ids for pages that could
651 if (page_zone_id(page
) != page_zone_id(buddy
))
654 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
662 * Freeing function for a buddy system allocator.
664 * The concept of a buddy system is to maintain direct-mapped table
665 * (containing bit values) for memory blocks of various "orders".
666 * The bottom level table contains the map for the smallest allocatable
667 * units of memory (here, pages), and each level above it describes
668 * pairs of units from the levels below, hence, "buddies".
669 * At a high level, all that happens here is marking the table entry
670 * at the bottom level available, and propagating the changes upward
671 * as necessary, plus some accounting needed to play nicely with other
672 * parts of the VM system.
673 * At each level, we keep a list of pages, which are heads of continuous
674 * free pages of length of (1 << order) and marked with _mapcount
675 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
677 * So when we are allocating or freeing one, we can derive the state of the
678 * other. That is, if we allocate a small block, and both were
679 * free, the remainder of the region must be split into blocks.
680 * If a block is freed, and its buddy is also free, then this
681 * triggers coalescing into a block of larger size.
686 static inline void __free_one_page(struct page
*page
,
688 struct zone
*zone
, unsigned int order
,
691 unsigned long page_idx
;
692 unsigned long combined_idx
;
693 unsigned long uninitialized_var(buddy_idx
);
695 unsigned int max_order
;
697 max_order
= min_t(unsigned int, MAX_ORDER
, pageblock_order
+ 1);
699 VM_BUG_ON(!zone_is_initialized(zone
));
700 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
702 VM_BUG_ON(migratetype
== -1);
703 if (likely(!is_migrate_isolate(migratetype
)))
704 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
706 page_idx
= pfn
& ((1 << MAX_ORDER
) - 1);
708 VM_BUG_ON_PAGE(page_idx
& ((1 << order
) - 1), page
);
709 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
712 while (order
< max_order
- 1) {
713 buddy_idx
= __find_buddy_index(page_idx
, order
);
714 buddy
= page
+ (buddy_idx
- page_idx
);
715 if (!page_is_buddy(page
, buddy
, order
))
718 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
719 * merge with it and move up one order.
721 if (page_is_guard(buddy
)) {
722 clear_page_guard(zone
, buddy
, order
, migratetype
);
724 list_del(&buddy
->lru
);
725 zone
->free_area
[order
].nr_free
--;
726 rmv_page_order(buddy
);
728 combined_idx
= buddy_idx
& page_idx
;
729 page
= page
+ (combined_idx
- page_idx
);
730 page_idx
= combined_idx
;
733 if (max_order
< MAX_ORDER
) {
734 /* If we are here, it means order is >= pageblock_order.
735 * We want to prevent merge between freepages on isolate
736 * pageblock and normal pageblock. Without this, pageblock
737 * isolation could cause incorrect freepage or CMA accounting.
739 * We don't want to hit this code for the more frequent
742 if (unlikely(has_isolate_pageblock(zone
))) {
745 buddy_idx
= __find_buddy_index(page_idx
, order
);
746 buddy
= page
+ (buddy_idx
- page_idx
);
747 buddy_mt
= get_pageblock_migratetype(buddy
);
749 if (migratetype
!= buddy_mt
750 && (is_migrate_isolate(migratetype
) ||
751 is_migrate_isolate(buddy_mt
)))
755 goto continue_merging
;
759 set_page_order(page
, order
);
762 * If this is not the largest possible page, check if the buddy
763 * of the next-highest order is free. If it is, it's possible
764 * that pages are being freed that will coalesce soon. In case,
765 * that is happening, add the free page to the tail of the list
766 * so it's less likely to be used soon and more likely to be merged
767 * as a higher order page
769 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
770 struct page
*higher_page
, *higher_buddy
;
771 combined_idx
= buddy_idx
& page_idx
;
772 higher_page
= page
+ (combined_idx
- page_idx
);
773 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
774 higher_buddy
= higher_page
+ (buddy_idx
- combined_idx
);
775 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
776 list_add_tail(&page
->lru
,
777 &zone
->free_area
[order
].free_list
[migratetype
]);
782 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
784 zone
->free_area
[order
].nr_free
++;
787 static inline int free_pages_check(struct page
*page
)
789 const char *bad_reason
= NULL
;
790 unsigned long bad_flags
= 0;
792 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
793 bad_reason
= "nonzero mapcount";
794 if (unlikely(page
->mapping
!= NULL
))
795 bad_reason
= "non-NULL mapping";
796 if (unlikely(page_ref_count(page
) != 0))
797 bad_reason
= "nonzero _refcount";
798 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
799 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
800 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
803 if (unlikely(page
->mem_cgroup
))
804 bad_reason
= "page still charged to cgroup";
806 if (unlikely(bad_reason
)) {
807 bad_page(page
, bad_reason
, bad_flags
);
810 page_cpupid_reset_last(page
);
811 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
812 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
817 * Frees a number of pages from the PCP lists
818 * Assumes all pages on list are in same zone, and of same order.
819 * count is the number of pages to free.
821 * If the zone was previously in an "all pages pinned" state then look to
822 * see if this freeing clears that state.
824 * And clear the zone's pages_scanned counter, to hold off the "all pages are
825 * pinned" detection logic.
827 static void free_pcppages_bulk(struct zone
*zone
, int count
,
828 struct per_cpu_pages
*pcp
)
833 unsigned long nr_scanned
;
835 spin_lock(&zone
->lock
);
836 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
838 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
842 struct list_head
*list
;
845 * Remove pages from lists in a round-robin fashion. A
846 * batch_free count is maintained that is incremented when an
847 * empty list is encountered. This is so more pages are freed
848 * off fuller lists instead of spinning excessively around empty
853 if (++migratetype
== MIGRATE_PCPTYPES
)
855 list
= &pcp
->lists
[migratetype
];
856 } while (list_empty(list
));
858 /* This is the only non-empty list. Free them all. */
859 if (batch_free
== MIGRATE_PCPTYPES
)
860 batch_free
= to_free
;
863 int mt
; /* migratetype of the to-be-freed page */
865 page
= list_last_entry(list
, struct page
, lru
);
866 /* must delete as __free_one_page list manipulates */
867 list_del(&page
->lru
);
869 mt
= get_pcppage_migratetype(page
);
870 /* MIGRATE_ISOLATE page should not go to pcplists */
871 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
872 /* Pageblock could have been isolated meanwhile */
873 if (unlikely(has_isolate_pageblock(zone
)))
874 mt
= get_pageblock_migratetype(page
);
876 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
);
877 trace_mm_page_pcpu_drain(page
, 0, mt
);
878 } while (--to_free
&& --batch_free
&& !list_empty(list
));
880 spin_unlock(&zone
->lock
);
883 static void free_one_page(struct zone
*zone
,
884 struct page
*page
, unsigned long pfn
,
888 unsigned long nr_scanned
;
889 spin_lock(&zone
->lock
);
890 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
892 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
894 if (unlikely(has_isolate_pageblock(zone
) ||
895 is_migrate_isolate(migratetype
))) {
896 migratetype
= get_pfnblock_migratetype(page
, pfn
);
898 __free_one_page(page
, pfn
, zone
, order
, migratetype
);
899 spin_unlock(&zone
->lock
);
902 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
907 * We rely page->lru.next never has bit 0 set, unless the page
908 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
910 BUILD_BUG_ON((unsigned long)LIST_POISON1
& 1);
912 if (!IS_ENABLED(CONFIG_DEBUG_VM
)) {
916 switch (page
- head_page
) {
918 /* the first tail page: ->mapping is compound_mapcount() */
919 if (unlikely(compound_mapcount(page
))) {
920 bad_page(page
, "nonzero compound_mapcount", 0);
926 * the second tail page: ->mapping is
927 * page_deferred_list().next -- ignore value.
931 if (page
->mapping
!= TAIL_MAPPING
) {
932 bad_page(page
, "corrupted mapping in tail page", 0);
937 if (unlikely(!PageTail(page
))) {
938 bad_page(page
, "PageTail not set", 0);
941 if (unlikely(compound_head(page
) != head_page
)) {
942 bad_page(page
, "compound_head not consistent", 0);
947 page
->mapping
= NULL
;
948 clear_compound_head(page
);
952 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
953 unsigned long zone
, int nid
)
955 set_page_links(page
, zone
, nid
, pfn
);
956 init_page_count(page
);
957 page_mapcount_reset(page
);
958 page_cpupid_reset_last(page
);
960 INIT_LIST_HEAD(&page
->lru
);
961 #ifdef WANT_PAGE_VIRTUAL
962 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
963 if (!is_highmem_idx(zone
))
964 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
968 static void __meminit
__init_single_pfn(unsigned long pfn
, unsigned long zone
,
971 return __init_single_page(pfn_to_page(pfn
), pfn
, zone
, nid
);
974 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
975 static void init_reserved_page(unsigned long pfn
)
980 if (!early_page_uninitialised(pfn
))
983 nid
= early_pfn_to_nid(pfn
);
984 pgdat
= NODE_DATA(nid
);
986 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
987 struct zone
*zone
= &pgdat
->node_zones
[zid
];
989 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
992 __init_single_pfn(pfn
, zid
, nid
);
995 static inline void init_reserved_page(unsigned long pfn
)
998 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1001 * Initialised pages do not have PageReserved set. This function is
1002 * called for each range allocated by the bootmem allocator and
1003 * marks the pages PageReserved. The remaining valid pages are later
1004 * sent to the buddy page allocator.
1006 void __meminit
reserve_bootmem_region(unsigned long start
, unsigned long end
)
1008 unsigned long start_pfn
= PFN_DOWN(start
);
1009 unsigned long end_pfn
= PFN_UP(end
);
1011 for (; start_pfn
< end_pfn
; start_pfn
++) {
1012 if (pfn_valid(start_pfn
)) {
1013 struct page
*page
= pfn_to_page(start_pfn
);
1015 init_reserved_page(start_pfn
);
1017 /* Avoid false-positive PageTail() */
1018 INIT_LIST_HEAD(&page
->lru
);
1020 SetPageReserved(page
);
1025 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
1027 bool compound
= PageCompound(page
);
1030 VM_BUG_ON_PAGE(PageTail(page
), page
);
1031 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
1033 trace_mm_page_free(page
, order
);
1034 kmemcheck_free_shadow(page
, order
);
1035 kasan_free_pages(page
, order
);
1038 page
->mapping
= NULL
;
1039 bad
+= free_pages_check(page
);
1040 for (i
= 1; i
< (1 << order
); i
++) {
1042 bad
+= free_tail_pages_check(page
, page
+ i
);
1043 bad
+= free_pages_check(page
+ i
);
1048 reset_page_owner(page
, order
);
1050 if (!PageHighMem(page
)) {
1051 debug_check_no_locks_freed(page_address(page
),
1052 PAGE_SIZE
<< order
);
1053 debug_check_no_obj_freed(page_address(page
),
1054 PAGE_SIZE
<< order
);
1056 arch_free_page(page
, order
);
1057 kernel_poison_pages(page
, 1 << order
, 0);
1058 kernel_map_pages(page
, 1 << order
, 0);
1063 static void __free_pages_ok(struct page
*page
, unsigned int order
)
1065 unsigned long flags
;
1067 unsigned long pfn
= page_to_pfn(page
);
1069 if (!free_pages_prepare(page
, order
))
1072 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1073 local_irq_save(flags
);
1074 __count_vm_events(PGFREE
, 1 << order
);
1075 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
1076 local_irq_restore(flags
);
1079 static void __init
__free_pages_boot_core(struct page
*page
, unsigned int order
)
1081 unsigned int nr_pages
= 1 << order
;
1082 struct page
*p
= page
;
1086 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
1088 __ClearPageReserved(p
);
1089 set_page_count(p
, 0);
1091 __ClearPageReserved(p
);
1092 set_page_count(p
, 0);
1094 page_zone(page
)->managed_pages
+= nr_pages
;
1095 set_page_refcounted(page
);
1096 __free_pages(page
, order
);
1099 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1100 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1102 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1104 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1106 static DEFINE_SPINLOCK(early_pfn_lock
);
1109 spin_lock(&early_pfn_lock
);
1110 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1113 spin_unlock(&early_pfn_lock
);
1119 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1120 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1121 struct mminit_pfnnid_cache
*state
)
1125 nid
= __early_pfn_to_nid(pfn
, state
);
1126 if (nid
>= 0 && nid
!= node
)
1131 /* Only safe to use early in boot when initialisation is single-threaded */
1132 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1134 return meminit_pfn_in_nid(pfn
, node
, &early_pfnnid_cache
);
1139 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1143 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1144 struct mminit_pfnnid_cache
*state
)
1151 void __init
__free_pages_bootmem(struct page
*page
, unsigned long pfn
,
1154 if (early_page_uninitialised(pfn
))
1156 return __free_pages_boot_core(page
, order
);
1160 * Check that the whole (or subset of) a pageblock given by the interval of
1161 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1162 * with the migration of free compaction scanner. The scanners then need to
1163 * use only pfn_valid_within() check for arches that allow holes within
1166 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1168 * It's possible on some configurations to have a setup like node0 node1 node0
1169 * i.e. it's possible that all pages within a zones range of pages do not
1170 * belong to a single zone. We assume that a border between node0 and node1
1171 * can occur within a single pageblock, but not a node0 node1 node0
1172 * interleaving within a single pageblock. It is therefore sufficient to check
1173 * the first and last page of a pageblock and avoid checking each individual
1174 * page in a pageblock.
1176 struct page
*__pageblock_pfn_to_page(unsigned long start_pfn
,
1177 unsigned long end_pfn
, struct zone
*zone
)
1179 struct page
*start_page
;
1180 struct page
*end_page
;
1182 /* end_pfn is one past the range we are checking */
1185 if (!pfn_valid(start_pfn
) || !pfn_valid(end_pfn
))
1188 start_page
= pfn_to_page(start_pfn
);
1190 if (page_zone(start_page
) != zone
)
1193 end_page
= pfn_to_page(end_pfn
);
1195 /* This gives a shorter code than deriving page_zone(end_page) */
1196 if (page_zone_id(start_page
) != page_zone_id(end_page
))
1202 void set_zone_contiguous(struct zone
*zone
)
1204 unsigned long block_start_pfn
= zone
->zone_start_pfn
;
1205 unsigned long block_end_pfn
;
1207 block_end_pfn
= ALIGN(block_start_pfn
+ 1, pageblock_nr_pages
);
1208 for (; block_start_pfn
< zone_end_pfn(zone
);
1209 block_start_pfn
= block_end_pfn
,
1210 block_end_pfn
+= pageblock_nr_pages
) {
1212 block_end_pfn
= min(block_end_pfn
, zone_end_pfn(zone
));
1214 if (!__pageblock_pfn_to_page(block_start_pfn
,
1215 block_end_pfn
, zone
))
1219 /* We confirm that there is no hole */
1220 zone
->contiguous
= true;
1223 void clear_zone_contiguous(struct zone
*zone
)
1225 zone
->contiguous
= false;
1228 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1229 static void __init
deferred_free_range(struct page
*page
,
1230 unsigned long pfn
, int nr_pages
)
1237 /* Free a large naturally-aligned chunk if possible */
1238 if (nr_pages
== MAX_ORDER_NR_PAGES
&&
1239 (pfn
& (MAX_ORDER_NR_PAGES
-1)) == 0) {
1240 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1241 __free_pages_boot_core(page
, MAX_ORDER
-1);
1245 for (i
= 0; i
< nr_pages
; i
++, page
++)
1246 __free_pages_boot_core(page
, 0);
1249 /* Completion tracking for deferred_init_memmap() threads */
1250 static atomic_t pgdat_init_n_undone __initdata
;
1251 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1253 static inline void __init
pgdat_init_report_one_done(void)
1255 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1256 complete(&pgdat_init_all_done_comp
);
1259 /* Initialise remaining memory on a node */
1260 static int __init
deferred_init_memmap(void *data
)
1262 pg_data_t
*pgdat
= data
;
1263 int nid
= pgdat
->node_id
;
1264 struct mminit_pfnnid_cache nid_init_state
= { };
1265 unsigned long start
= jiffies
;
1266 unsigned long nr_pages
= 0;
1267 unsigned long walk_start
, walk_end
;
1270 unsigned long first_init_pfn
= pgdat
->first_deferred_pfn
;
1271 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1273 if (first_init_pfn
== ULONG_MAX
) {
1274 pgdat_init_report_one_done();
1278 /* Bind memory initialisation thread to a local node if possible */
1279 if (!cpumask_empty(cpumask
))
1280 set_cpus_allowed_ptr(current
, cpumask
);
1282 /* Sanity check boundaries */
1283 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1284 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1285 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1287 /* Only the highest zone is deferred so find it */
1288 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1289 zone
= pgdat
->node_zones
+ zid
;
1290 if (first_init_pfn
< zone_end_pfn(zone
))
1294 for_each_mem_pfn_range(i
, nid
, &walk_start
, &walk_end
, NULL
) {
1295 unsigned long pfn
, end_pfn
;
1296 struct page
*page
= NULL
;
1297 struct page
*free_base_page
= NULL
;
1298 unsigned long free_base_pfn
= 0;
1301 end_pfn
= min(walk_end
, zone_end_pfn(zone
));
1302 pfn
= first_init_pfn
;
1303 if (pfn
< walk_start
)
1305 if (pfn
< zone
->zone_start_pfn
)
1306 pfn
= zone
->zone_start_pfn
;
1308 for (; pfn
< end_pfn
; pfn
++) {
1309 if (!pfn_valid_within(pfn
))
1313 * Ensure pfn_valid is checked every
1314 * MAX_ORDER_NR_PAGES for memory holes
1316 if ((pfn
& (MAX_ORDER_NR_PAGES
- 1)) == 0) {
1317 if (!pfn_valid(pfn
)) {
1323 if (!meminit_pfn_in_nid(pfn
, nid
, &nid_init_state
)) {
1328 /* Minimise pfn page lookups and scheduler checks */
1329 if (page
&& (pfn
& (MAX_ORDER_NR_PAGES
- 1)) != 0) {
1332 nr_pages
+= nr_to_free
;
1333 deferred_free_range(free_base_page
,
1334 free_base_pfn
, nr_to_free
);
1335 free_base_page
= NULL
;
1336 free_base_pfn
= nr_to_free
= 0;
1338 page
= pfn_to_page(pfn
);
1343 VM_BUG_ON(page_zone(page
) != zone
);
1347 __init_single_page(page
, pfn
, zid
, nid
);
1348 if (!free_base_page
) {
1349 free_base_page
= page
;
1350 free_base_pfn
= pfn
;
1355 /* Where possible, batch up pages for a single free */
1358 /* Free the current block of pages to allocator */
1359 nr_pages
+= nr_to_free
;
1360 deferred_free_range(free_base_page
, free_base_pfn
,
1362 free_base_page
= NULL
;
1363 free_base_pfn
= nr_to_free
= 0;
1366 first_init_pfn
= max(end_pfn
, first_init_pfn
);
1369 /* Sanity check that the next zone really is unpopulated */
1370 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1372 pr_info("node %d initialised, %lu pages in %ums\n", nid
, nr_pages
,
1373 jiffies_to_msecs(jiffies
- start
));
1375 pgdat_init_report_one_done();
1378 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1380 void __init
page_alloc_init_late(void)
1384 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1387 /* There will be num_node_state(N_MEMORY) threads */
1388 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
1389 for_each_node_state(nid
, N_MEMORY
) {
1390 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
1393 /* Block until all are initialised */
1394 wait_for_completion(&pgdat_init_all_done_comp
);
1396 /* Reinit limits that are based on free pages after the kernel is up */
1397 files_maxfiles_init();
1400 for_each_populated_zone(zone
)
1401 set_zone_contiguous(zone
);
1405 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1406 void __init
init_cma_reserved_pageblock(struct page
*page
)
1408 unsigned i
= pageblock_nr_pages
;
1409 struct page
*p
= page
;
1412 __ClearPageReserved(p
);
1413 set_page_count(p
, 0);
1416 set_pageblock_migratetype(page
, MIGRATE_CMA
);
1418 if (pageblock_order
>= MAX_ORDER
) {
1419 i
= pageblock_nr_pages
;
1422 set_page_refcounted(p
);
1423 __free_pages(p
, MAX_ORDER
- 1);
1424 p
+= MAX_ORDER_NR_PAGES
;
1425 } while (i
-= MAX_ORDER_NR_PAGES
);
1427 set_page_refcounted(page
);
1428 __free_pages(page
, pageblock_order
);
1431 adjust_managed_page_count(page
, pageblock_nr_pages
);
1436 * The order of subdivision here is critical for the IO subsystem.
1437 * Please do not alter this order without good reasons and regression
1438 * testing. Specifically, as large blocks of memory are subdivided,
1439 * the order in which smaller blocks are delivered depends on the order
1440 * they're subdivided in this function. This is the primary factor
1441 * influencing the order in which pages are delivered to the IO
1442 * subsystem according to empirical testing, and this is also justified
1443 * by considering the behavior of a buddy system containing a single
1444 * large block of memory acted on by a series of small allocations.
1445 * This behavior is a critical factor in sglist merging's success.
1449 static inline void expand(struct zone
*zone
, struct page
*page
,
1450 int low
, int high
, struct free_area
*area
,
1453 unsigned long size
= 1 << high
;
1455 while (high
> low
) {
1459 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
1461 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC
) &&
1462 debug_guardpage_enabled() &&
1463 high
< debug_guardpage_minorder()) {
1465 * Mark as guard pages (or page), that will allow to
1466 * merge back to allocator when buddy will be freed.
1467 * Corresponding page table entries will not be touched,
1468 * pages will stay not present in virtual address space
1470 set_page_guard(zone
, &page
[size
], high
, migratetype
);
1473 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
1475 set_page_order(&page
[size
], high
);
1480 * This page is about to be returned from the page allocator
1482 static inline int check_new_page(struct page
*page
)
1484 const char *bad_reason
= NULL
;
1485 unsigned long bad_flags
= 0;
1487 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1488 bad_reason
= "nonzero mapcount";
1489 if (unlikely(page
->mapping
!= NULL
))
1490 bad_reason
= "non-NULL mapping";
1491 if (unlikely(page_ref_count(page
) != 0))
1492 bad_reason
= "nonzero _count";
1493 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
1494 bad_reason
= "HWPoisoned (hardware-corrupted)";
1495 bad_flags
= __PG_HWPOISON
;
1497 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
1498 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
1499 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
1502 if (unlikely(page
->mem_cgroup
))
1503 bad_reason
= "page still charged to cgroup";
1505 if (unlikely(bad_reason
)) {
1506 bad_page(page
, bad_reason
, bad_flags
);
1512 static inline bool free_pages_prezeroed(bool poisoned
)
1514 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO
) &&
1515 page_poisoning_enabled() && poisoned
;
1518 static int prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
1522 bool poisoned
= true;
1524 for (i
= 0; i
< (1 << order
); i
++) {
1525 struct page
*p
= page
+ i
;
1526 if (unlikely(check_new_page(p
)))
1529 poisoned
&= page_is_poisoned(p
);
1532 set_page_private(page
, 0);
1533 set_page_refcounted(page
);
1535 arch_alloc_page(page
, order
);
1536 kernel_map_pages(page
, 1 << order
, 1);
1537 kernel_poison_pages(page
, 1 << order
, 1);
1538 kasan_alloc_pages(page
, order
);
1540 if (!free_pages_prezeroed(poisoned
) && (gfp_flags
& __GFP_ZERO
))
1541 for (i
= 0; i
< (1 << order
); i
++)
1542 clear_highpage(page
+ i
);
1544 if (order
&& (gfp_flags
& __GFP_COMP
))
1545 prep_compound_page(page
, order
);
1547 set_page_owner(page
, order
, gfp_flags
);
1550 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1551 * allocate the page. The expectation is that the caller is taking
1552 * steps that will free more memory. The caller should avoid the page
1553 * being used for !PFMEMALLOC purposes.
1555 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
1556 set_page_pfmemalloc(page
);
1558 clear_page_pfmemalloc(page
);
1564 * Go through the free lists for the given migratetype and remove
1565 * the smallest available page from the freelists
1568 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
1571 unsigned int current_order
;
1572 struct free_area
*area
;
1575 /* Find a page of the appropriate size in the preferred list */
1576 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
1577 area
= &(zone
->free_area
[current_order
]);
1578 page
= list_first_entry_or_null(&area
->free_list
[migratetype
],
1582 list_del(&page
->lru
);
1583 rmv_page_order(page
);
1585 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1586 set_pcppage_migratetype(page
, migratetype
);
1595 * This array describes the order lists are fallen back to when
1596 * the free lists for the desirable migrate type are depleted
1598 static int fallbacks
[MIGRATE_TYPES
][4] = {
1599 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1600 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1601 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_TYPES
},
1603 [MIGRATE_CMA
] = { MIGRATE_TYPES
}, /* Never used */
1605 #ifdef CONFIG_MEMORY_ISOLATION
1606 [MIGRATE_ISOLATE
] = { MIGRATE_TYPES
}, /* Never used */
1611 static struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1614 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
1617 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1618 unsigned int order
) { return NULL
; }
1622 * Move the free pages in a range to the free lists of the requested type.
1623 * Note that start_page and end_pages are not aligned on a pageblock
1624 * boundary. If alignment is required, use move_freepages_block()
1626 int move_freepages(struct zone
*zone
,
1627 struct page
*start_page
, struct page
*end_page
,
1632 int pages_moved
= 0;
1634 #ifndef CONFIG_HOLES_IN_ZONE
1636 * page_zone is not safe to call in this context when
1637 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1638 * anyway as we check zone boundaries in move_freepages_block().
1639 * Remove at a later date when no bug reports exist related to
1640 * grouping pages by mobility
1642 VM_BUG_ON(page_zone(start_page
) != page_zone(end_page
));
1645 for (page
= start_page
; page
<= end_page
;) {
1646 /* Make sure we are not inadvertently changing nodes */
1647 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
1649 if (!pfn_valid_within(page_to_pfn(page
))) {
1654 if (!PageBuddy(page
)) {
1659 order
= page_order(page
);
1660 list_move(&page
->lru
,
1661 &zone
->free_area
[order
].free_list
[migratetype
]);
1663 pages_moved
+= 1 << order
;
1669 int move_freepages_block(struct zone
*zone
, struct page
*page
,
1672 unsigned long start_pfn
, end_pfn
;
1673 struct page
*start_page
, *end_page
;
1675 start_pfn
= page_to_pfn(page
);
1676 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
1677 start_page
= pfn_to_page(start_pfn
);
1678 end_page
= start_page
+ pageblock_nr_pages
- 1;
1679 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
1681 /* Do not cross zone boundaries */
1682 if (!zone_spans_pfn(zone
, start_pfn
))
1684 if (!zone_spans_pfn(zone
, end_pfn
))
1687 return move_freepages(zone
, start_page
, end_page
, migratetype
);
1690 static void change_pageblock_range(struct page
*pageblock_page
,
1691 int start_order
, int migratetype
)
1693 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1695 while (nr_pageblocks
--) {
1696 set_pageblock_migratetype(pageblock_page
, migratetype
);
1697 pageblock_page
+= pageblock_nr_pages
;
1702 * When we are falling back to another migratetype during allocation, try to
1703 * steal extra free pages from the same pageblocks to satisfy further
1704 * allocations, instead of polluting multiple pageblocks.
1706 * If we are stealing a relatively large buddy page, it is likely there will
1707 * be more free pages in the pageblock, so try to steal them all. For
1708 * reclaimable and unmovable allocations, we steal regardless of page size,
1709 * as fragmentation caused by those allocations polluting movable pageblocks
1710 * is worse than movable allocations stealing from unmovable and reclaimable
1713 static bool can_steal_fallback(unsigned int order
, int start_mt
)
1716 * Leaving this order check is intended, although there is
1717 * relaxed order check in next check. The reason is that
1718 * we can actually steal whole pageblock if this condition met,
1719 * but, below check doesn't guarantee it and that is just heuristic
1720 * so could be changed anytime.
1722 if (order
>= pageblock_order
)
1725 if (order
>= pageblock_order
/ 2 ||
1726 start_mt
== MIGRATE_RECLAIMABLE
||
1727 start_mt
== MIGRATE_UNMOVABLE
||
1728 page_group_by_mobility_disabled
)
1735 * This function implements actual steal behaviour. If order is large enough,
1736 * we can steal whole pageblock. If not, we first move freepages in this
1737 * pageblock and check whether half of pages are moved or not. If half of
1738 * pages are moved, we can change migratetype of pageblock and permanently
1739 * use it's pages as requested migratetype in the future.
1741 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
1744 unsigned int current_order
= page_order(page
);
1747 /* Take ownership for orders >= pageblock_order */
1748 if (current_order
>= pageblock_order
) {
1749 change_pageblock_range(page
, current_order
, start_type
);
1753 pages
= move_freepages_block(zone
, page
, start_type
);
1755 /* Claim the whole block if over half of it is free */
1756 if (pages
>= (1 << (pageblock_order
-1)) ||
1757 page_group_by_mobility_disabled
)
1758 set_pageblock_migratetype(page
, start_type
);
1762 * Check whether there is a suitable fallback freepage with requested order.
1763 * If only_stealable is true, this function returns fallback_mt only if
1764 * we can steal other freepages all together. This would help to reduce
1765 * fragmentation due to mixed migratetype pages in one pageblock.
1767 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
1768 int migratetype
, bool only_stealable
, bool *can_steal
)
1773 if (area
->nr_free
== 0)
1778 fallback_mt
= fallbacks
[migratetype
][i
];
1779 if (fallback_mt
== MIGRATE_TYPES
)
1782 if (list_empty(&area
->free_list
[fallback_mt
]))
1785 if (can_steal_fallback(order
, migratetype
))
1788 if (!only_stealable
)
1799 * Reserve a pageblock for exclusive use of high-order atomic allocations if
1800 * there are no empty page blocks that contain a page with a suitable order
1802 static void reserve_highatomic_pageblock(struct page
*page
, struct zone
*zone
,
1803 unsigned int alloc_order
)
1806 unsigned long max_managed
, flags
;
1809 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
1810 * Check is race-prone but harmless.
1812 max_managed
= (zone
->managed_pages
/ 100) + pageblock_nr_pages
;
1813 if (zone
->nr_reserved_highatomic
>= max_managed
)
1816 spin_lock_irqsave(&zone
->lock
, flags
);
1818 /* Recheck the nr_reserved_highatomic limit under the lock */
1819 if (zone
->nr_reserved_highatomic
>= max_managed
)
1823 mt
= get_pageblock_migratetype(page
);
1824 if (mt
!= MIGRATE_HIGHATOMIC
&&
1825 !is_migrate_isolate(mt
) && !is_migrate_cma(mt
)) {
1826 zone
->nr_reserved_highatomic
+= pageblock_nr_pages
;
1827 set_pageblock_migratetype(page
, MIGRATE_HIGHATOMIC
);
1828 move_freepages_block(zone
, page
, MIGRATE_HIGHATOMIC
);
1832 spin_unlock_irqrestore(&zone
->lock
, flags
);
1836 * Used when an allocation is about to fail under memory pressure. This
1837 * potentially hurts the reliability of high-order allocations when under
1838 * intense memory pressure but failed atomic allocations should be easier
1839 * to recover from than an OOM.
1841 static void unreserve_highatomic_pageblock(const struct alloc_context
*ac
)
1843 struct zonelist
*zonelist
= ac
->zonelist
;
1844 unsigned long flags
;
1850 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
1852 /* Preserve at least one pageblock */
1853 if (zone
->nr_reserved_highatomic
<= pageblock_nr_pages
)
1856 spin_lock_irqsave(&zone
->lock
, flags
);
1857 for (order
= 0; order
< MAX_ORDER
; order
++) {
1858 struct free_area
*area
= &(zone
->free_area
[order
]);
1860 page
= list_first_entry_or_null(
1861 &area
->free_list
[MIGRATE_HIGHATOMIC
],
1867 * It should never happen but changes to locking could
1868 * inadvertently allow a per-cpu drain to add pages
1869 * to MIGRATE_HIGHATOMIC while unreserving so be safe
1870 * and watch for underflows.
1872 zone
->nr_reserved_highatomic
-= min(pageblock_nr_pages
,
1873 zone
->nr_reserved_highatomic
);
1876 * Convert to ac->migratetype and avoid the normal
1877 * pageblock stealing heuristics. Minimally, the caller
1878 * is doing the work and needs the pages. More
1879 * importantly, if the block was always converted to
1880 * MIGRATE_UNMOVABLE or another type then the number
1881 * of pageblocks that cannot be completely freed
1884 set_pageblock_migratetype(page
, ac
->migratetype
);
1885 move_freepages_block(zone
, page
, ac
->migratetype
);
1886 spin_unlock_irqrestore(&zone
->lock
, flags
);
1889 spin_unlock_irqrestore(&zone
->lock
, flags
);
1893 /* Remove an element from the buddy allocator from the fallback list */
1894 static inline struct page
*
1895 __rmqueue_fallback(struct zone
*zone
, unsigned int order
, int start_migratetype
)
1897 struct free_area
*area
;
1898 unsigned int current_order
;
1903 /* Find the largest possible block of pages in the other list */
1904 for (current_order
= MAX_ORDER
-1;
1905 current_order
>= order
&& current_order
<= MAX_ORDER
-1;
1907 area
= &(zone
->free_area
[current_order
]);
1908 fallback_mt
= find_suitable_fallback(area
, current_order
,
1909 start_migratetype
, false, &can_steal
);
1910 if (fallback_mt
== -1)
1913 page
= list_first_entry(&area
->free_list
[fallback_mt
],
1916 steal_suitable_fallback(zone
, page
, start_migratetype
);
1918 /* Remove the page from the freelists */
1920 list_del(&page
->lru
);
1921 rmv_page_order(page
);
1923 expand(zone
, page
, order
, current_order
, area
,
1926 * The pcppage_migratetype may differ from pageblock's
1927 * migratetype depending on the decisions in
1928 * find_suitable_fallback(). This is OK as long as it does not
1929 * differ for MIGRATE_CMA pageblocks. Those can be used as
1930 * fallback only via special __rmqueue_cma_fallback() function
1932 set_pcppage_migratetype(page
, start_migratetype
);
1934 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
1935 start_migratetype
, fallback_mt
);
1944 * Do the hard work of removing an element from the buddy allocator.
1945 * Call me with the zone->lock already held.
1947 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
1952 page
= __rmqueue_smallest(zone
, order
, migratetype
);
1953 if (unlikely(!page
)) {
1954 if (migratetype
== MIGRATE_MOVABLE
)
1955 page
= __rmqueue_cma_fallback(zone
, order
);
1958 page
= __rmqueue_fallback(zone
, order
, migratetype
);
1961 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1966 * Obtain a specified number of elements from the buddy allocator, all under
1967 * a single hold of the lock, for efficiency. Add them to the supplied list.
1968 * Returns the number of new pages which were placed at *list.
1970 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1971 unsigned long count
, struct list_head
*list
,
1972 int migratetype
, bool cold
)
1976 spin_lock(&zone
->lock
);
1977 for (i
= 0; i
< count
; ++i
) {
1978 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
1979 if (unlikely(page
== NULL
))
1983 * Split buddy pages returned by expand() are received here
1984 * in physical page order. The page is added to the callers and
1985 * list and the list head then moves forward. From the callers
1986 * perspective, the linked list is ordered by page number in
1987 * some conditions. This is useful for IO devices that can
1988 * merge IO requests if the physical pages are ordered
1992 list_add(&page
->lru
, list
);
1994 list_add_tail(&page
->lru
, list
);
1996 if (is_migrate_cma(get_pcppage_migratetype(page
)))
1997 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
2000 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
2001 spin_unlock(&zone
->lock
);
2007 * Called from the vmstat counter updater to drain pagesets of this
2008 * currently executing processor on remote nodes after they have
2011 * Note that this function must be called with the thread pinned to
2012 * a single processor.
2014 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
2016 unsigned long flags
;
2017 int to_drain
, batch
;
2019 local_irq_save(flags
);
2020 batch
= READ_ONCE(pcp
->batch
);
2021 to_drain
= min(pcp
->count
, batch
);
2023 free_pcppages_bulk(zone
, to_drain
, pcp
);
2024 pcp
->count
-= to_drain
;
2026 local_irq_restore(flags
);
2031 * Drain pcplists of the indicated processor and zone.
2033 * The processor must either be the current processor and the
2034 * thread pinned to the current processor or a processor that
2037 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
2039 unsigned long flags
;
2040 struct per_cpu_pageset
*pset
;
2041 struct per_cpu_pages
*pcp
;
2043 local_irq_save(flags
);
2044 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
2048 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
2051 local_irq_restore(flags
);
2055 * Drain pcplists of all zones on the indicated processor.
2057 * The processor must either be the current processor and the
2058 * thread pinned to the current processor or a processor that
2061 static void drain_pages(unsigned int cpu
)
2065 for_each_populated_zone(zone
) {
2066 drain_pages_zone(cpu
, zone
);
2071 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2073 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2074 * the single zone's pages.
2076 void drain_local_pages(struct zone
*zone
)
2078 int cpu
= smp_processor_id();
2081 drain_pages_zone(cpu
, zone
);
2087 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2089 * When zone parameter is non-NULL, spill just the single zone's pages.
2091 * Note that this code is protected against sending an IPI to an offline
2092 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
2093 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
2094 * nothing keeps CPUs from showing up after we populated the cpumask and
2095 * before the call to on_each_cpu_mask().
2097 void drain_all_pages(struct zone
*zone
)
2102 * Allocate in the BSS so we wont require allocation in
2103 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2105 static cpumask_t cpus_with_pcps
;
2108 * We don't care about racing with CPU hotplug event
2109 * as offline notification will cause the notified
2110 * cpu to drain that CPU pcps and on_each_cpu_mask
2111 * disables preemption as part of its processing
2113 for_each_online_cpu(cpu
) {
2114 struct per_cpu_pageset
*pcp
;
2116 bool has_pcps
= false;
2119 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
2123 for_each_populated_zone(z
) {
2124 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
2125 if (pcp
->pcp
.count
) {
2133 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
2135 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
2137 on_each_cpu_mask(&cpus_with_pcps
, (smp_call_func_t
) drain_local_pages
,
2141 #ifdef CONFIG_HIBERNATION
2143 void mark_free_pages(struct zone
*zone
)
2145 unsigned long pfn
, max_zone_pfn
;
2146 unsigned long flags
;
2147 unsigned int order
, t
;
2150 if (zone_is_empty(zone
))
2153 spin_lock_irqsave(&zone
->lock
, flags
);
2155 max_zone_pfn
= zone_end_pfn(zone
);
2156 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
2157 if (pfn_valid(pfn
)) {
2158 page
= pfn_to_page(pfn
);
2159 if (!swsusp_page_is_forbidden(page
))
2160 swsusp_unset_page_free(page
);
2163 for_each_migratetype_order(order
, t
) {
2164 list_for_each_entry(page
,
2165 &zone
->free_area
[order
].free_list
[t
], lru
) {
2168 pfn
= page_to_pfn(page
);
2169 for (i
= 0; i
< (1UL << order
); i
++)
2170 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
2173 spin_unlock_irqrestore(&zone
->lock
, flags
);
2175 #endif /* CONFIG_PM */
2178 * Free a 0-order page
2179 * cold == true ? free a cold page : free a hot page
2181 void free_hot_cold_page(struct page
*page
, bool cold
)
2183 struct zone
*zone
= page_zone(page
);
2184 struct per_cpu_pages
*pcp
;
2185 unsigned long flags
;
2186 unsigned long pfn
= page_to_pfn(page
);
2189 if (!free_pages_prepare(page
, 0))
2192 migratetype
= get_pfnblock_migratetype(page
, pfn
);
2193 set_pcppage_migratetype(page
, migratetype
);
2194 local_irq_save(flags
);
2195 __count_vm_event(PGFREE
);
2198 * We only track unmovable, reclaimable and movable on pcp lists.
2199 * Free ISOLATE pages back to the allocator because they are being
2200 * offlined but treat RESERVE as movable pages so we can get those
2201 * areas back if necessary. Otherwise, we may have to free
2202 * excessively into the page allocator
2204 if (migratetype
>= MIGRATE_PCPTYPES
) {
2205 if (unlikely(is_migrate_isolate(migratetype
))) {
2206 free_one_page(zone
, page
, pfn
, 0, migratetype
);
2209 migratetype
= MIGRATE_MOVABLE
;
2212 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2214 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
2216 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
2218 if (pcp
->count
>= pcp
->high
) {
2219 unsigned long batch
= READ_ONCE(pcp
->batch
);
2220 free_pcppages_bulk(zone
, batch
, pcp
);
2221 pcp
->count
-= batch
;
2225 local_irq_restore(flags
);
2229 * Free a list of 0-order pages
2231 void free_hot_cold_page_list(struct list_head
*list
, bool cold
)
2233 struct page
*page
, *next
;
2235 list_for_each_entry_safe(page
, next
, list
, lru
) {
2236 trace_mm_page_free_batched(page
, cold
);
2237 free_hot_cold_page(page
, cold
);
2242 * split_page takes a non-compound higher-order page, and splits it into
2243 * n (1<<order) sub-pages: page[0..n]
2244 * Each sub-page must be freed individually.
2246 * Note: this is probably too low level an operation for use in drivers.
2247 * Please consult with lkml before using this in your driver.
2249 void split_page(struct page
*page
, unsigned int order
)
2254 VM_BUG_ON_PAGE(PageCompound(page
), page
);
2255 VM_BUG_ON_PAGE(!page_count(page
), page
);
2257 #ifdef CONFIG_KMEMCHECK
2259 * Split shadow pages too, because free(page[0]) would
2260 * otherwise free the whole shadow.
2262 if (kmemcheck_page_is_tracked(page
))
2263 split_page(virt_to_page(page
[0].shadow
), order
);
2266 gfp_mask
= get_page_owner_gfp(page
);
2267 set_page_owner(page
, 0, gfp_mask
);
2268 for (i
= 1; i
< (1 << order
); i
++) {
2269 set_page_refcounted(page
+ i
);
2270 set_page_owner(page
+ i
, 0, gfp_mask
);
2273 EXPORT_SYMBOL_GPL(split_page
);
2275 int __isolate_free_page(struct page
*page
, unsigned int order
)
2277 unsigned long watermark
;
2281 BUG_ON(!PageBuddy(page
));
2283 zone
= page_zone(page
);
2284 mt
= get_pageblock_migratetype(page
);
2286 if (!is_migrate_isolate(mt
)) {
2287 /* Obey watermarks as if the page was being allocated */
2288 watermark
= low_wmark_pages(zone
) + (1 << order
);
2289 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
2292 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
2295 /* Remove page from free list */
2296 list_del(&page
->lru
);
2297 zone
->free_area
[order
].nr_free
--;
2298 rmv_page_order(page
);
2300 set_page_owner(page
, order
, __GFP_MOVABLE
);
2302 /* Set the pageblock if the isolated page is at least a pageblock */
2303 if (order
>= pageblock_order
- 1) {
2304 struct page
*endpage
= page
+ (1 << order
) - 1;
2305 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
2306 int mt
= get_pageblock_migratetype(page
);
2307 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
))
2308 set_pageblock_migratetype(page
,
2314 return 1UL << order
;
2318 * Similar to split_page except the page is already free. As this is only
2319 * being used for migration, the migratetype of the block also changes.
2320 * As this is called with interrupts disabled, the caller is responsible
2321 * for calling arch_alloc_page() and kernel_map_page() after interrupts
2324 * Note: this is probably too low level an operation for use in drivers.
2325 * Please consult with lkml before using this in your driver.
2327 int split_free_page(struct page
*page
)
2332 order
= page_order(page
);
2334 nr_pages
= __isolate_free_page(page
, order
);
2338 /* Split into individual pages */
2339 set_page_refcounted(page
);
2340 split_page(page
, order
);
2345 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2348 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
2349 struct zone
*zone
, unsigned int order
,
2350 gfp_t gfp_flags
, int alloc_flags
, int migratetype
)
2352 unsigned long flags
;
2354 bool cold
= ((gfp_flags
& __GFP_COLD
) != 0);
2356 if (likely(order
== 0)) {
2357 struct per_cpu_pages
*pcp
;
2358 struct list_head
*list
;
2360 local_irq_save(flags
);
2361 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2362 list
= &pcp
->lists
[migratetype
];
2363 if (list_empty(list
)) {
2364 pcp
->count
+= rmqueue_bulk(zone
, 0,
2367 if (unlikely(list_empty(list
)))
2372 page
= list_last_entry(list
, struct page
, lru
);
2374 page
= list_first_entry(list
, struct page
, lru
);
2376 list_del(&page
->lru
);
2380 * We most definitely don't want callers attempting to
2381 * allocate greater than order-1 page units with __GFP_NOFAIL.
2383 WARN_ON_ONCE((gfp_flags
& __GFP_NOFAIL
) && (order
> 1));
2384 spin_lock_irqsave(&zone
->lock
, flags
);
2387 if (alloc_flags
& ALLOC_HARDER
) {
2388 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
2390 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2393 page
= __rmqueue(zone
, order
, migratetype
);
2394 spin_unlock(&zone
->lock
);
2397 __mod_zone_freepage_state(zone
, -(1 << order
),
2398 get_pcppage_migratetype(page
));
2401 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
, -(1 << order
));
2402 if (atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]) <= 0 &&
2403 !test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
))
2404 set_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2406 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
2407 zone_statistics(preferred_zone
, zone
, gfp_flags
);
2408 local_irq_restore(flags
);
2410 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
2414 local_irq_restore(flags
);
2418 #ifdef CONFIG_FAIL_PAGE_ALLOC
2421 struct fault_attr attr
;
2423 bool ignore_gfp_highmem
;
2424 bool ignore_gfp_reclaim
;
2426 } fail_page_alloc
= {
2427 .attr
= FAULT_ATTR_INITIALIZER
,
2428 .ignore_gfp_reclaim
= true,
2429 .ignore_gfp_highmem
= true,
2433 static int __init
setup_fail_page_alloc(char *str
)
2435 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
2437 __setup("fail_page_alloc=", setup_fail_page_alloc
);
2439 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2441 if (order
< fail_page_alloc
.min_order
)
2443 if (gfp_mask
& __GFP_NOFAIL
)
2445 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
2447 if (fail_page_alloc
.ignore_gfp_reclaim
&&
2448 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
2451 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
2454 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2456 static int __init
fail_page_alloc_debugfs(void)
2458 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
2461 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
2462 &fail_page_alloc
.attr
);
2464 return PTR_ERR(dir
);
2466 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
2467 &fail_page_alloc
.ignore_gfp_reclaim
))
2469 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
2470 &fail_page_alloc
.ignore_gfp_highmem
))
2472 if (!debugfs_create_u32("min-order", mode
, dir
,
2473 &fail_page_alloc
.min_order
))
2478 debugfs_remove_recursive(dir
);
2483 late_initcall(fail_page_alloc_debugfs
);
2485 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2487 #else /* CONFIG_FAIL_PAGE_ALLOC */
2489 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2494 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2497 * Return true if free base pages are above 'mark'. For high-order checks it
2498 * will return true of the order-0 watermark is reached and there is at least
2499 * one free page of a suitable size. Checking now avoids taking the zone lock
2500 * to check in the allocation paths if no pages are free.
2502 static bool __zone_watermark_ok(struct zone
*z
, unsigned int order
,
2503 unsigned long mark
, int classzone_idx
, int alloc_flags
,
2508 const int alloc_harder
= (alloc_flags
& ALLOC_HARDER
);
2510 /* free_pages may go negative - that's OK */
2511 free_pages
-= (1 << order
) - 1;
2513 if (alloc_flags
& ALLOC_HIGH
)
2517 * If the caller does not have rights to ALLOC_HARDER then subtract
2518 * the high-atomic reserves. This will over-estimate the size of the
2519 * atomic reserve but it avoids a search.
2521 if (likely(!alloc_harder
))
2522 free_pages
-= z
->nr_reserved_highatomic
;
2527 /* If allocation can't use CMA areas don't use free CMA pages */
2528 if (!(alloc_flags
& ALLOC_CMA
))
2529 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2533 * Check watermarks for an order-0 allocation request. If these
2534 * are not met, then a high-order request also cannot go ahead
2535 * even if a suitable page happened to be free.
2537 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
2540 /* If this is an order-0 request then the watermark is fine */
2544 /* For a high-order request, check at least one suitable page is free */
2545 for (o
= order
; o
< MAX_ORDER
; o
++) {
2546 struct free_area
*area
= &z
->free_area
[o
];
2555 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
2556 if (!list_empty(&area
->free_list
[mt
]))
2561 if ((alloc_flags
& ALLOC_CMA
) &&
2562 !list_empty(&area
->free_list
[MIGRATE_CMA
])) {
2570 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2571 int classzone_idx
, int alloc_flags
)
2573 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
2574 zone_page_state(z
, NR_FREE_PAGES
));
2577 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
2578 unsigned long mark
, int classzone_idx
)
2580 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
2582 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
2583 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
2585 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, 0,
2590 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2592 return local_zone
->node
== zone
->node
;
2595 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2597 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <
2600 #else /* CONFIG_NUMA */
2601 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2606 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2610 #endif /* CONFIG_NUMA */
2612 static void reset_alloc_batches(struct zone
*preferred_zone
)
2614 struct zone
*zone
= preferred_zone
->zone_pgdat
->node_zones
;
2617 mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
2618 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
2619 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
2620 clear_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2621 } while (zone
++ != preferred_zone
);
2625 * get_page_from_freelist goes through the zonelist trying to allocate
2628 static struct page
*
2629 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
2630 const struct alloc_context
*ac
)
2632 struct zonelist
*zonelist
= ac
->zonelist
;
2634 struct page
*page
= NULL
;
2636 int nr_fair_skipped
= 0;
2637 bool zonelist_rescan
;
2640 zonelist_rescan
= false;
2643 * Scan zonelist, looking for a zone with enough free.
2644 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2646 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
2650 if (cpusets_enabled() &&
2651 (alloc_flags
& ALLOC_CPUSET
) &&
2652 !cpuset_zone_allowed(zone
, gfp_mask
))
2655 * Distribute pages in proportion to the individual
2656 * zone size to ensure fair page aging. The zone a
2657 * page was allocated in should have no effect on the
2658 * time the page has in memory before being reclaimed.
2660 if (alloc_flags
& ALLOC_FAIR
) {
2661 if (!zone_local(ac
->preferred_zone
, zone
))
2663 if (test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
)) {
2669 * When allocating a page cache page for writing, we
2670 * want to get it from a zone that is within its dirty
2671 * limit, such that no single zone holds more than its
2672 * proportional share of globally allowed dirty pages.
2673 * The dirty limits take into account the zone's
2674 * lowmem reserves and high watermark so that kswapd
2675 * should be able to balance it without having to
2676 * write pages from its LRU list.
2678 * This may look like it could increase pressure on
2679 * lower zones by failing allocations in higher zones
2680 * before they are full. But the pages that do spill
2681 * over are limited as the lower zones are protected
2682 * by this very same mechanism. It should not become
2683 * a practical burden to them.
2685 * XXX: For now, allow allocations to potentially
2686 * exceed the per-zone dirty limit in the slowpath
2687 * (spread_dirty_pages unset) before going into reclaim,
2688 * which is important when on a NUMA setup the allowed
2689 * zones are together not big enough to reach the
2690 * global limit. The proper fix for these situations
2691 * will require awareness of zones in the
2692 * dirty-throttling and the flusher threads.
2694 if (ac
->spread_dirty_pages
&& !zone_dirty_ok(zone
))
2697 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
2698 if (!zone_watermark_ok(zone
, order
, mark
,
2699 ac
->classzone_idx
, alloc_flags
)) {
2702 /* Checked here to keep the fast path fast */
2703 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
2704 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
2707 if (zone_reclaim_mode
== 0 ||
2708 !zone_allows_reclaim(ac
->preferred_zone
, zone
))
2711 ret
= zone_reclaim(zone
, gfp_mask
, order
);
2713 case ZONE_RECLAIM_NOSCAN
:
2716 case ZONE_RECLAIM_FULL
:
2717 /* scanned but unreclaimable */
2720 /* did we reclaim enough */
2721 if (zone_watermark_ok(zone
, order
, mark
,
2722 ac
->classzone_idx
, alloc_flags
))
2730 page
= buffered_rmqueue(ac
->preferred_zone
, zone
, order
,
2731 gfp_mask
, alloc_flags
, ac
->migratetype
);
2733 if (prep_new_page(page
, order
, gfp_mask
, alloc_flags
))
2737 * If this is a high-order atomic allocation then check
2738 * if the pageblock should be reserved for the future
2740 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
2741 reserve_highatomic_pageblock(page
, zone
, order
);
2748 * The first pass makes sure allocations are spread fairly within the
2749 * local node. However, the local node might have free pages left
2750 * after the fairness batches are exhausted, and remote zones haven't
2751 * even been considered yet. Try once more without fairness, and
2752 * include remote zones now, before entering the slowpath and waking
2753 * kswapd: prefer spilling to a remote zone over swapping locally.
2755 if (alloc_flags
& ALLOC_FAIR
) {
2756 alloc_flags
&= ~ALLOC_FAIR
;
2757 if (nr_fair_skipped
) {
2758 zonelist_rescan
= true;
2759 reset_alloc_batches(ac
->preferred_zone
);
2761 if (nr_online_nodes
> 1)
2762 zonelist_rescan
= true;
2765 if (zonelist_rescan
)
2772 * Large machines with many possible nodes should not always dump per-node
2773 * meminfo in irq context.
2775 static inline bool should_suppress_show_mem(void)
2780 ret
= in_interrupt();
2785 static DEFINE_RATELIMIT_STATE(nopage_rs
,
2786 DEFAULT_RATELIMIT_INTERVAL
,
2787 DEFAULT_RATELIMIT_BURST
);
2789 void warn_alloc_failed(gfp_t gfp_mask
, unsigned int order
, const char *fmt
, ...)
2791 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
2793 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
2794 debug_guardpage_minorder() > 0)
2798 * This documents exceptions given to allocations in certain
2799 * contexts that are allowed to allocate outside current's set
2802 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2803 if (test_thread_flag(TIF_MEMDIE
) ||
2804 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
2805 filter
&= ~SHOW_MEM_FILTER_NODES
;
2806 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
2807 filter
&= ~SHOW_MEM_FILTER_NODES
;
2810 struct va_format vaf
;
2813 va_start(args
, fmt
);
2818 pr_warn("%pV", &vaf
);
2823 pr_warn("%s: page allocation failure: order:%u, mode:%#x(%pGg)\n",
2824 current
->comm
, order
, gfp_mask
, &gfp_mask
);
2826 if (!should_suppress_show_mem())
2830 static inline struct page
*
2831 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
2832 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
2834 struct oom_control oc
= {
2835 .zonelist
= ac
->zonelist
,
2836 .nodemask
= ac
->nodemask
,
2837 .gfp_mask
= gfp_mask
,
2842 *did_some_progress
= 0;
2845 * Acquire the oom lock. If that fails, somebody else is
2846 * making progress for us.
2848 if (!mutex_trylock(&oom_lock
)) {
2849 *did_some_progress
= 1;
2850 schedule_timeout_uninterruptible(1);
2855 * Go through the zonelist yet one more time, keep very high watermark
2856 * here, this is only to catch a parallel oom killing, we must fail if
2857 * we're still under heavy pressure.
2859 page
= get_page_from_freelist(gfp_mask
| __GFP_HARDWALL
, order
,
2860 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
2864 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2865 /* Coredumps can quickly deplete all memory reserves */
2866 if (current
->flags
& PF_DUMPCORE
)
2868 /* The OOM killer will not help higher order allocs */
2869 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2871 /* The OOM killer does not needlessly kill tasks for lowmem */
2872 if (ac
->high_zoneidx
< ZONE_NORMAL
)
2874 /* The OOM killer does not compensate for IO-less reclaim */
2875 if (!(gfp_mask
& __GFP_FS
)) {
2877 * XXX: Page reclaim didn't yield anything,
2878 * and the OOM killer can't be invoked, but
2879 * keep looping as per tradition.
2881 * But do not keep looping if oom_killer_disable()
2882 * was already called, for the system is trying to
2883 * enter a quiescent state during suspend.
2885 *did_some_progress
= !oom_killer_disabled
;
2888 if (pm_suspended_storage())
2890 /* The OOM killer may not free memory on a specific node */
2891 if (gfp_mask
& __GFP_THISNODE
)
2894 /* Exhausted what can be done so it's blamo time */
2895 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
2896 *did_some_progress
= 1;
2898 if (gfp_mask
& __GFP_NOFAIL
) {
2899 page
= get_page_from_freelist(gfp_mask
, order
,
2900 ALLOC_NO_WATERMARKS
|ALLOC_CPUSET
, ac
);
2902 * fallback to ignore cpuset restriction if our nodes
2906 page
= get_page_from_freelist(gfp_mask
, order
,
2907 ALLOC_NO_WATERMARKS
, ac
);
2911 mutex_unlock(&oom_lock
);
2915 #ifdef CONFIG_COMPACTION
2916 /* Try memory compaction for high-order allocations before reclaim */
2917 static struct page
*
2918 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2919 int alloc_flags
, const struct alloc_context
*ac
,
2920 enum migrate_mode mode
, int *contended_compaction
,
2921 bool *deferred_compaction
)
2923 unsigned long compact_result
;
2929 current
->flags
|= PF_MEMALLOC
;
2930 compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
2931 mode
, contended_compaction
);
2932 current
->flags
&= ~PF_MEMALLOC
;
2934 switch (compact_result
) {
2935 case COMPACT_DEFERRED
:
2936 *deferred_compaction
= true;
2938 case COMPACT_SKIPPED
:
2945 * At least in one zone compaction wasn't deferred or skipped, so let's
2946 * count a compaction stall
2948 count_vm_event(COMPACTSTALL
);
2950 page
= get_page_from_freelist(gfp_mask
, order
,
2951 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
2954 struct zone
*zone
= page_zone(page
);
2956 zone
->compact_blockskip_flush
= false;
2957 compaction_defer_reset(zone
, order
, true);
2958 count_vm_event(COMPACTSUCCESS
);
2963 * It's bad if compaction run occurs and fails. The most likely reason
2964 * is that pages exist, but not enough to satisfy watermarks.
2966 count_vm_event(COMPACTFAIL
);
2973 static inline struct page
*
2974 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2975 int alloc_flags
, const struct alloc_context
*ac
,
2976 enum migrate_mode mode
, int *contended_compaction
,
2977 bool *deferred_compaction
)
2981 #endif /* CONFIG_COMPACTION */
2983 /* Perform direct synchronous page reclaim */
2985 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
2986 const struct alloc_context
*ac
)
2988 struct reclaim_state reclaim_state
;
2993 /* We now go into synchronous reclaim */
2994 cpuset_memory_pressure_bump();
2995 current
->flags
|= PF_MEMALLOC
;
2996 lockdep_set_current_reclaim_state(gfp_mask
);
2997 reclaim_state
.reclaimed_slab
= 0;
2998 current
->reclaim_state
= &reclaim_state
;
3000 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
3003 current
->reclaim_state
= NULL
;
3004 lockdep_clear_current_reclaim_state();
3005 current
->flags
&= ~PF_MEMALLOC
;
3012 /* The really slow allocator path where we enter direct reclaim */
3013 static inline struct page
*
3014 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
3015 int alloc_flags
, const struct alloc_context
*ac
,
3016 unsigned long *did_some_progress
)
3018 struct page
*page
= NULL
;
3019 bool drained
= false;
3021 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
3022 if (unlikely(!(*did_some_progress
)))
3026 page
= get_page_from_freelist(gfp_mask
, order
,
3027 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3030 * If an allocation failed after direct reclaim, it could be because
3031 * pages are pinned on the per-cpu lists or in high alloc reserves.
3032 * Shrink them them and try again
3034 if (!page
&& !drained
) {
3035 unreserve_highatomic_pageblock(ac
);
3036 drain_all_pages(NULL
);
3044 static void wake_all_kswapds(unsigned int order
, const struct alloc_context
*ac
)
3049 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
3050 ac
->high_zoneidx
, ac
->nodemask
)
3051 wakeup_kswapd(zone
, order
, zone_idx(ac
->preferred_zone
));
3055 gfp_to_alloc_flags(gfp_t gfp_mask
)
3057 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
3059 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3060 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
3063 * The caller may dip into page reserves a bit more if the caller
3064 * cannot run direct reclaim, or if the caller has realtime scheduling
3065 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3066 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3068 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
3070 if (gfp_mask
& __GFP_ATOMIC
) {
3072 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3073 * if it can't schedule.
3075 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3076 alloc_flags
|= ALLOC_HARDER
;
3078 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3079 * comment for __cpuset_node_allowed().
3081 alloc_flags
&= ~ALLOC_CPUSET
;
3082 } else if (unlikely(rt_task(current
)) && !in_interrupt())
3083 alloc_flags
|= ALLOC_HARDER
;
3085 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
3086 if (gfp_mask
& __GFP_MEMALLOC
)
3087 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3088 else if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
3089 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3090 else if (!in_interrupt() &&
3091 ((current
->flags
& PF_MEMALLOC
) ||
3092 unlikely(test_thread_flag(TIF_MEMDIE
))))
3093 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3096 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
3097 alloc_flags
|= ALLOC_CMA
;
3102 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
3104 return !!(gfp_to_alloc_flags(gfp_mask
) & ALLOC_NO_WATERMARKS
);
3107 static inline bool is_thp_gfp_mask(gfp_t gfp_mask
)
3109 return (gfp_mask
& (GFP_TRANSHUGE
| __GFP_KSWAPD_RECLAIM
)) == GFP_TRANSHUGE
;
3112 static inline struct page
*
3113 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
3114 struct alloc_context
*ac
)
3116 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
3117 struct page
*page
= NULL
;
3119 unsigned long pages_reclaimed
= 0;
3120 unsigned long did_some_progress
;
3121 enum migrate_mode migration_mode
= MIGRATE_ASYNC
;
3122 bool deferred_compaction
= false;
3123 int contended_compaction
= COMPACT_CONTENDED_NONE
;
3126 * In the slowpath, we sanity check order to avoid ever trying to
3127 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3128 * be using allocators in order of preference for an area that is
3131 if (order
>= MAX_ORDER
) {
3132 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
3137 * We also sanity check to catch abuse of atomic reserves being used by
3138 * callers that are not in atomic context.
3140 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
3141 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
3142 gfp_mask
&= ~__GFP_ATOMIC
;
3145 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3146 wake_all_kswapds(order
, ac
);
3149 * OK, we're below the kswapd watermark and have kicked background
3150 * reclaim. Now things get more complex, so set up alloc_flags according
3151 * to how we want to proceed.
3153 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
3156 * Find the true preferred zone if the allocation is unconstrained by
3159 if (!(alloc_flags
& ALLOC_CPUSET
) && !ac
->nodemask
) {
3160 struct zoneref
*preferred_zoneref
;
3161 preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3162 ac
->high_zoneidx
, NULL
, &ac
->preferred_zone
);
3163 ac
->classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
3166 /* This is the last chance, in general, before the goto nopage. */
3167 page
= get_page_from_freelist(gfp_mask
, order
,
3168 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3172 /* Allocate without watermarks if the context allows */
3173 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
3175 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
3176 * the allocation is high priority and these type of
3177 * allocations are system rather than user orientated
3179 ac
->zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
3180 page
= get_page_from_freelist(gfp_mask
, order
,
3181 ALLOC_NO_WATERMARKS
, ac
);
3186 /* Caller is not willing to reclaim, we can't balance anything */
3187 if (!can_direct_reclaim
) {
3189 * All existing users of the __GFP_NOFAIL are blockable, so warn
3190 * of any new users that actually allow this type of allocation
3193 WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
);
3197 /* Avoid recursion of direct reclaim */
3198 if (current
->flags
& PF_MEMALLOC
) {
3200 * __GFP_NOFAIL request from this context is rather bizarre
3201 * because we cannot reclaim anything and only can loop waiting
3202 * for somebody to do a work for us.
3204 if (WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3211 /* Avoid allocations with no watermarks from looping endlessly */
3212 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
3216 * Try direct compaction. The first pass is asynchronous. Subsequent
3217 * attempts after direct reclaim are synchronous
3219 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
3221 &contended_compaction
,
3222 &deferred_compaction
);
3226 /* Checks for THP-specific high-order allocations */
3227 if (is_thp_gfp_mask(gfp_mask
)) {
3229 * If compaction is deferred for high-order allocations, it is
3230 * because sync compaction recently failed. If this is the case
3231 * and the caller requested a THP allocation, we do not want
3232 * to heavily disrupt the system, so we fail the allocation
3233 * instead of entering direct reclaim.
3235 if (deferred_compaction
)
3239 * In all zones where compaction was attempted (and not
3240 * deferred or skipped), lock contention has been detected.
3241 * For THP allocation we do not want to disrupt the others
3242 * so we fallback to base pages instead.
3244 if (contended_compaction
== COMPACT_CONTENDED_LOCK
)
3248 * If compaction was aborted due to need_resched(), we do not
3249 * want to further increase allocation latency, unless it is
3250 * khugepaged trying to collapse.
3252 if (contended_compaction
== COMPACT_CONTENDED_SCHED
3253 && !(current
->flags
& PF_KTHREAD
))
3258 * It can become very expensive to allocate transparent hugepages at
3259 * fault, so use asynchronous memory compaction for THP unless it is
3260 * khugepaged trying to collapse.
3262 if (!is_thp_gfp_mask(gfp_mask
) || (current
->flags
& PF_KTHREAD
))
3263 migration_mode
= MIGRATE_SYNC_LIGHT
;
3265 /* Try direct reclaim and then allocating */
3266 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
3267 &did_some_progress
);
3271 /* Do not loop if specifically requested */
3272 if (gfp_mask
& __GFP_NORETRY
)
3275 /* Keep reclaiming pages as long as there is reasonable progress */
3276 pages_reclaimed
+= did_some_progress
;
3277 if ((did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
) ||
3278 ((gfp_mask
& __GFP_REPEAT
) && pages_reclaimed
< (1 << order
))) {
3279 /* Wait for some write requests to complete then retry */
3280 wait_iff_congested(ac
->preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
3284 /* Reclaim has failed us, start killing things */
3285 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
3289 /* Retry as long as the OOM killer is making progress */
3290 if (did_some_progress
)
3295 * High-order allocations do not necessarily loop after
3296 * direct reclaim and reclaim/compaction depends on compaction
3297 * being called after reclaim so call directly if necessary
3299 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
,
3301 &contended_compaction
,
3302 &deferred_compaction
);
3306 warn_alloc_failed(gfp_mask
, order
, NULL
);
3312 * This is the 'heart' of the zoned buddy allocator.
3315 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
3316 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
3318 struct zoneref
*preferred_zoneref
;
3319 struct page
*page
= NULL
;
3320 unsigned int cpuset_mems_cookie
;
3321 int alloc_flags
= ALLOC_WMARK_LOW
|ALLOC_CPUSET
|ALLOC_FAIR
;
3322 gfp_t alloc_mask
; /* The gfp_t that was actually used for allocation */
3323 struct alloc_context ac
= {
3324 .high_zoneidx
= gfp_zone(gfp_mask
),
3325 .nodemask
= nodemask
,
3326 .migratetype
= gfpflags_to_migratetype(gfp_mask
),
3329 gfp_mask
&= gfp_allowed_mask
;
3331 lockdep_trace_alloc(gfp_mask
);
3333 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
3335 if (should_fail_alloc_page(gfp_mask
, order
))
3339 * Check the zones suitable for the gfp_mask contain at least one
3340 * valid zone. It's possible to have an empty zonelist as a result
3341 * of __GFP_THISNODE and a memoryless node
3343 if (unlikely(!zonelist
->_zonerefs
->zone
))
3346 if (IS_ENABLED(CONFIG_CMA
) && ac
.migratetype
== MIGRATE_MOVABLE
)
3347 alloc_flags
|= ALLOC_CMA
;
3350 cpuset_mems_cookie
= read_mems_allowed_begin();
3352 /* We set it here, as __alloc_pages_slowpath might have changed it */
3353 ac
.zonelist
= zonelist
;
3355 /* Dirty zone balancing only done in the fast path */
3356 ac
.spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
3358 /* The preferred zone is used for statistics later */
3359 preferred_zoneref
= first_zones_zonelist(ac
.zonelist
, ac
.high_zoneidx
,
3360 ac
.nodemask
? : &cpuset_current_mems_allowed
,
3361 &ac
.preferred_zone
);
3362 if (!ac
.preferred_zone
)
3364 ac
.classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
3366 /* First allocation attempt */
3367 alloc_mask
= gfp_mask
|__GFP_HARDWALL
;
3368 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
3369 if (unlikely(!page
)) {
3371 * Runtime PM, block IO and its error handling path
3372 * can deadlock because I/O on the device might not
3375 alloc_mask
= memalloc_noio_flags(gfp_mask
);
3376 ac
.spread_dirty_pages
= false;
3378 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
3381 if (kmemcheck_enabled
&& page
)
3382 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
3384 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
3388 * When updating a task's mems_allowed, it is possible to race with
3389 * parallel threads in such a way that an allocation can fail while
3390 * the mask is being updated. If a page allocation is about to fail,
3391 * check if the cpuset changed during allocation and if so, retry.
3393 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
)))
3398 EXPORT_SYMBOL(__alloc_pages_nodemask
);
3401 * Common helper functions.
3403 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
3408 * __get_free_pages() returns a 32-bit address, which cannot represent
3411 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
3413 page
= alloc_pages(gfp_mask
, order
);
3416 return (unsigned long) page_address(page
);
3418 EXPORT_SYMBOL(__get_free_pages
);
3420 unsigned long get_zeroed_page(gfp_t gfp_mask
)
3422 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
3424 EXPORT_SYMBOL(get_zeroed_page
);
3426 void __free_pages(struct page
*page
, unsigned int order
)
3428 if (put_page_testzero(page
)) {
3430 free_hot_cold_page(page
, false);
3432 __free_pages_ok(page
, order
);
3436 EXPORT_SYMBOL(__free_pages
);
3438 void free_pages(unsigned long addr
, unsigned int order
)
3441 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3442 __free_pages(virt_to_page((void *)addr
), order
);
3446 EXPORT_SYMBOL(free_pages
);
3450 * An arbitrary-length arbitrary-offset area of memory which resides
3451 * within a 0 or higher order page. Multiple fragments within that page
3452 * are individually refcounted, in the page's reference counter.
3454 * The page_frag functions below provide a simple allocation framework for
3455 * page fragments. This is used by the network stack and network device
3456 * drivers to provide a backing region of memory for use as either an
3457 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3459 static struct page
*__page_frag_refill(struct page_frag_cache
*nc
,
3462 struct page
*page
= NULL
;
3463 gfp_t gfp
= gfp_mask
;
3465 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3466 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
3468 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
3469 PAGE_FRAG_CACHE_MAX_ORDER
);
3470 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
3472 if (unlikely(!page
))
3473 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
3475 nc
->va
= page
? page_address(page
) : NULL
;
3480 void *__alloc_page_frag(struct page_frag_cache
*nc
,
3481 unsigned int fragsz
, gfp_t gfp_mask
)
3483 unsigned int size
= PAGE_SIZE
;
3487 if (unlikely(!nc
->va
)) {
3489 page
= __page_frag_refill(nc
, gfp_mask
);
3493 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3494 /* if size can vary use size else just use PAGE_SIZE */
3497 /* Even if we own the page, we do not use atomic_set().
3498 * This would break get_page_unless_zero() users.
3500 page_ref_add(page
, size
- 1);
3502 /* reset page count bias and offset to start of new frag */
3503 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
3504 nc
->pagecnt_bias
= size
;
3508 offset
= nc
->offset
- fragsz
;
3509 if (unlikely(offset
< 0)) {
3510 page
= virt_to_page(nc
->va
);
3512 if (!page_ref_sub_and_test(page
, nc
->pagecnt_bias
))
3515 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3516 /* if size can vary use size else just use PAGE_SIZE */
3519 /* OK, page count is 0, we can safely set it */
3520 set_page_count(page
, size
);
3522 /* reset page count bias and offset to start of new frag */
3523 nc
->pagecnt_bias
= size
;
3524 offset
= size
- fragsz
;
3528 nc
->offset
= offset
;
3530 return nc
->va
+ offset
;
3532 EXPORT_SYMBOL(__alloc_page_frag
);
3535 * Frees a page fragment allocated out of either a compound or order 0 page.
3537 void __free_page_frag(void *addr
)
3539 struct page
*page
= virt_to_head_page(addr
);
3541 if (unlikely(put_page_testzero(page
)))
3542 __free_pages_ok(page
, compound_order(page
));
3544 EXPORT_SYMBOL(__free_page_frag
);
3547 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
3548 * of the current memory cgroup if __GFP_ACCOUNT is set, other than that it is
3549 * equivalent to alloc_pages.
3551 * It should be used when the caller would like to use kmalloc, but since the
3552 * allocation is large, it has to fall back to the page allocator.
3554 struct page
*alloc_kmem_pages(gfp_t gfp_mask
, unsigned int order
)
3558 page
= alloc_pages(gfp_mask
, order
);
3559 if (page
&& memcg_kmem_charge(page
, gfp_mask
, order
) != 0) {
3560 __free_pages(page
, order
);
3566 struct page
*alloc_kmem_pages_node(int nid
, gfp_t gfp_mask
, unsigned int order
)
3570 page
= alloc_pages_node(nid
, gfp_mask
, order
);
3571 if (page
&& memcg_kmem_charge(page
, gfp_mask
, order
) != 0) {
3572 __free_pages(page
, order
);
3579 * __free_kmem_pages and free_kmem_pages will free pages allocated with
3582 void __free_kmem_pages(struct page
*page
, unsigned int order
)
3584 memcg_kmem_uncharge(page
, order
);
3585 __free_pages(page
, order
);
3588 void free_kmem_pages(unsigned long addr
, unsigned int order
)
3591 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3592 __free_kmem_pages(virt_to_page((void *)addr
), order
);
3596 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
3600 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
3601 unsigned long used
= addr
+ PAGE_ALIGN(size
);
3603 split_page(virt_to_page((void *)addr
), order
);
3604 while (used
< alloc_end
) {
3609 return (void *)addr
;
3613 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
3614 * @size: the number of bytes to allocate
3615 * @gfp_mask: GFP flags for the allocation
3617 * This function is similar to alloc_pages(), except that it allocates the
3618 * minimum number of pages to satisfy the request. alloc_pages() can only
3619 * allocate memory in power-of-two pages.
3621 * This function is also limited by MAX_ORDER.
3623 * Memory allocated by this function must be released by free_pages_exact().
3625 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
3627 unsigned int order
= get_order(size
);
3630 addr
= __get_free_pages(gfp_mask
, order
);
3631 return make_alloc_exact(addr
, order
, size
);
3633 EXPORT_SYMBOL(alloc_pages_exact
);
3636 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3638 * @nid: the preferred node ID where memory should be allocated
3639 * @size: the number of bytes to allocate
3640 * @gfp_mask: GFP flags for the allocation
3642 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3645 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
3647 unsigned int order
= get_order(size
);
3648 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
3651 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
3655 * free_pages_exact - release memory allocated via alloc_pages_exact()
3656 * @virt: the value returned by alloc_pages_exact.
3657 * @size: size of allocation, same value as passed to alloc_pages_exact().
3659 * Release the memory allocated by a previous call to alloc_pages_exact.
3661 void free_pages_exact(void *virt
, size_t size
)
3663 unsigned long addr
= (unsigned long)virt
;
3664 unsigned long end
= addr
+ PAGE_ALIGN(size
);
3666 while (addr
< end
) {
3671 EXPORT_SYMBOL(free_pages_exact
);
3674 * nr_free_zone_pages - count number of pages beyond high watermark
3675 * @offset: The zone index of the highest zone
3677 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3678 * high watermark within all zones at or below a given zone index. For each
3679 * zone, the number of pages is calculated as:
3680 * managed_pages - high_pages
3682 static unsigned long nr_free_zone_pages(int offset
)
3687 /* Just pick one node, since fallback list is circular */
3688 unsigned long sum
= 0;
3690 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
3692 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
3693 unsigned long size
= zone
->managed_pages
;
3694 unsigned long high
= high_wmark_pages(zone
);
3703 * nr_free_buffer_pages - count number of pages beyond high watermark
3705 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3706 * watermark within ZONE_DMA and ZONE_NORMAL.
3708 unsigned long nr_free_buffer_pages(void)
3710 return nr_free_zone_pages(gfp_zone(GFP_USER
));
3712 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
3715 * nr_free_pagecache_pages - count number of pages beyond high watermark
3717 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3718 * high watermark within all zones.
3720 unsigned long nr_free_pagecache_pages(void)
3722 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
3725 static inline void show_node(struct zone
*zone
)
3727 if (IS_ENABLED(CONFIG_NUMA
))
3728 printk("Node %d ", zone_to_nid(zone
));
3731 long si_mem_available(void)
3734 unsigned long pagecache
;
3735 unsigned long wmark_low
= 0;
3736 unsigned long pages
[NR_LRU_LISTS
];
3740 for (lru
= LRU_BASE
; lru
< NR_LRU_LISTS
; lru
++)
3741 pages
[lru
] = global_page_state(NR_LRU_BASE
+ lru
);
3744 wmark_low
+= zone
->watermark
[WMARK_LOW
];
3747 * Estimate the amount of memory available for userspace allocations,
3748 * without causing swapping.
3750 available
= global_page_state(NR_FREE_PAGES
) - totalreserve_pages
;
3753 * Not all the page cache can be freed, otherwise the system will
3754 * start swapping. Assume at least half of the page cache, or the
3755 * low watermark worth of cache, needs to stay.
3757 pagecache
= pages
[LRU_ACTIVE_FILE
] + pages
[LRU_INACTIVE_FILE
];
3758 pagecache
-= min(pagecache
/ 2, wmark_low
);
3759 available
+= pagecache
;
3762 * Part of the reclaimable slab consists of items that are in use,
3763 * and cannot be freed. Cap this estimate at the low watermark.
3765 available
+= global_page_state(NR_SLAB_RECLAIMABLE
) -
3766 min(global_page_state(NR_SLAB_RECLAIMABLE
) / 2, wmark_low
);
3772 EXPORT_SYMBOL_GPL(si_mem_available
);
3774 void si_meminfo(struct sysinfo
*val
)
3776 val
->totalram
= totalram_pages
;
3777 val
->sharedram
= global_page_state(NR_SHMEM
);
3778 val
->freeram
= global_page_state(NR_FREE_PAGES
);
3779 val
->bufferram
= nr_blockdev_pages();
3780 val
->totalhigh
= totalhigh_pages
;
3781 val
->freehigh
= nr_free_highpages();
3782 val
->mem_unit
= PAGE_SIZE
;
3785 EXPORT_SYMBOL(si_meminfo
);
3788 void si_meminfo_node(struct sysinfo
*val
, int nid
)
3790 int zone_type
; /* needs to be signed */
3791 unsigned long managed_pages
= 0;
3792 pg_data_t
*pgdat
= NODE_DATA(nid
);
3794 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
3795 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
3796 val
->totalram
= managed_pages
;
3797 val
->sharedram
= node_page_state(nid
, NR_SHMEM
);
3798 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
3799 #ifdef CONFIG_HIGHMEM
3800 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].managed_pages
;
3801 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
3807 val
->mem_unit
= PAGE_SIZE
;
3812 * Determine whether the node should be displayed or not, depending on whether
3813 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3815 bool skip_free_areas_node(unsigned int flags
, int nid
)
3818 unsigned int cpuset_mems_cookie
;
3820 if (!(flags
& SHOW_MEM_FILTER_NODES
))
3824 cpuset_mems_cookie
= read_mems_allowed_begin();
3825 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
3826 } while (read_mems_allowed_retry(cpuset_mems_cookie
));
3831 #define K(x) ((x) << (PAGE_SHIFT-10))
3833 static void show_migration_types(unsigned char type
)
3835 static const char types
[MIGRATE_TYPES
] = {
3836 [MIGRATE_UNMOVABLE
] = 'U',
3837 [MIGRATE_MOVABLE
] = 'M',
3838 [MIGRATE_RECLAIMABLE
] = 'E',
3839 [MIGRATE_HIGHATOMIC
] = 'H',
3841 [MIGRATE_CMA
] = 'C',
3843 #ifdef CONFIG_MEMORY_ISOLATION
3844 [MIGRATE_ISOLATE
] = 'I',
3847 char tmp
[MIGRATE_TYPES
+ 1];
3851 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
3852 if (type
& (1 << i
))
3857 printk("(%s) ", tmp
);
3861 * Show free area list (used inside shift_scroll-lock stuff)
3862 * We also calculate the percentage fragmentation. We do this by counting the
3863 * memory on each free list with the exception of the first item on the list.
3866 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
3869 void show_free_areas(unsigned int filter
)
3871 unsigned long free_pcp
= 0;
3875 for_each_populated_zone(zone
) {
3876 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3879 for_each_online_cpu(cpu
)
3880 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
3883 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3884 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3885 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
3886 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3887 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3888 " free:%lu free_pcp:%lu free_cma:%lu\n",
3889 global_page_state(NR_ACTIVE_ANON
),
3890 global_page_state(NR_INACTIVE_ANON
),
3891 global_page_state(NR_ISOLATED_ANON
),
3892 global_page_state(NR_ACTIVE_FILE
),
3893 global_page_state(NR_INACTIVE_FILE
),
3894 global_page_state(NR_ISOLATED_FILE
),
3895 global_page_state(NR_UNEVICTABLE
),
3896 global_page_state(NR_FILE_DIRTY
),
3897 global_page_state(NR_WRITEBACK
),
3898 global_page_state(NR_UNSTABLE_NFS
),
3899 global_page_state(NR_SLAB_RECLAIMABLE
),
3900 global_page_state(NR_SLAB_UNRECLAIMABLE
),
3901 global_page_state(NR_FILE_MAPPED
),
3902 global_page_state(NR_SHMEM
),
3903 global_page_state(NR_PAGETABLE
),
3904 global_page_state(NR_BOUNCE
),
3905 global_page_state(NR_FREE_PAGES
),
3907 global_page_state(NR_FREE_CMA_PAGES
));
3909 for_each_populated_zone(zone
) {
3912 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3916 for_each_online_cpu(cpu
)
3917 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
3925 " active_anon:%lukB"
3926 " inactive_anon:%lukB"
3927 " active_file:%lukB"
3928 " inactive_file:%lukB"
3929 " unevictable:%lukB"
3930 " isolated(anon):%lukB"
3931 " isolated(file):%lukB"
3939 " slab_reclaimable:%lukB"
3940 " slab_unreclaimable:%lukB"
3941 " kernel_stack:%lukB"
3948 " writeback_tmp:%lukB"
3949 " pages_scanned:%lu"
3950 " all_unreclaimable? %s"
3953 K(zone_page_state(zone
, NR_FREE_PAGES
)),
3954 K(min_wmark_pages(zone
)),
3955 K(low_wmark_pages(zone
)),
3956 K(high_wmark_pages(zone
)),
3957 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
3958 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
3959 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
3960 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
3961 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
3962 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
3963 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
3964 K(zone
->present_pages
),
3965 K(zone
->managed_pages
),
3966 K(zone_page_state(zone
, NR_MLOCK
)),
3967 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
3968 K(zone_page_state(zone
, NR_WRITEBACK
)),
3969 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
3970 K(zone_page_state(zone
, NR_SHMEM
)),
3971 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
3972 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
3973 zone_page_state(zone
, NR_KERNEL_STACK
) *
3975 K(zone_page_state(zone
, NR_PAGETABLE
)),
3976 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
3977 K(zone_page_state(zone
, NR_BOUNCE
)),
3979 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
3980 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)),
3981 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
3982 K(zone_page_state(zone
, NR_PAGES_SCANNED
)),
3983 (!zone_reclaimable(zone
) ? "yes" : "no")
3985 printk("lowmem_reserve[]:");
3986 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3987 printk(" %ld", zone
->lowmem_reserve
[i
]);
3991 for_each_populated_zone(zone
) {
3993 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
3994 unsigned char types
[MAX_ORDER
];
3996 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3999 printk("%s: ", zone
->name
);
4001 spin_lock_irqsave(&zone
->lock
, flags
);
4002 for (order
= 0; order
< MAX_ORDER
; order
++) {
4003 struct free_area
*area
= &zone
->free_area
[order
];
4006 nr
[order
] = area
->nr_free
;
4007 total
+= nr
[order
] << order
;
4010 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
4011 if (!list_empty(&area
->free_list
[type
]))
4012 types
[order
] |= 1 << type
;
4015 spin_unlock_irqrestore(&zone
->lock
, flags
);
4016 for (order
= 0; order
< MAX_ORDER
; order
++) {
4017 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
4019 show_migration_types(types
[order
]);
4021 printk("= %lukB\n", K(total
));
4024 hugetlb_show_meminfo();
4026 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
4028 show_swap_cache_info();
4031 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
4033 zoneref
->zone
= zone
;
4034 zoneref
->zone_idx
= zone_idx(zone
);
4038 * Builds allocation fallback zone lists.
4040 * Add all populated zones of a node to the zonelist.
4042 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
4046 enum zone_type zone_type
= MAX_NR_ZONES
;
4050 zone
= pgdat
->node_zones
+ zone_type
;
4051 if (populated_zone(zone
)) {
4052 zoneref_set_zone(zone
,
4053 &zonelist
->_zonerefs
[nr_zones
++]);
4054 check_highest_zone(zone_type
);
4056 } while (zone_type
);
4064 * 0 = automatic detection of better ordering.
4065 * 1 = order by ([node] distance, -zonetype)
4066 * 2 = order by (-zonetype, [node] distance)
4068 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4069 * the same zonelist. So only NUMA can configure this param.
4071 #define ZONELIST_ORDER_DEFAULT 0
4072 #define ZONELIST_ORDER_NODE 1
4073 #define ZONELIST_ORDER_ZONE 2
4075 /* zonelist order in the kernel.
4076 * set_zonelist_order() will set this to NODE or ZONE.
4078 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4079 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
4083 /* The value user specified ....changed by config */
4084 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4085 /* string for sysctl */
4086 #define NUMA_ZONELIST_ORDER_LEN 16
4087 char numa_zonelist_order
[16] = "default";
4090 * interface for configure zonelist ordering.
4091 * command line option "numa_zonelist_order"
4092 * = "[dD]efault - default, automatic configuration.
4093 * = "[nN]ode - order by node locality, then by zone within node
4094 * = "[zZ]one - order by zone, then by locality within zone
4097 static int __parse_numa_zonelist_order(char *s
)
4099 if (*s
== 'd' || *s
== 'D') {
4100 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4101 } else if (*s
== 'n' || *s
== 'N') {
4102 user_zonelist_order
= ZONELIST_ORDER_NODE
;
4103 } else if (*s
== 'z' || *s
== 'Z') {
4104 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
4106 pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s
);
4112 static __init
int setup_numa_zonelist_order(char *s
)
4119 ret
= __parse_numa_zonelist_order(s
);
4121 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
4125 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
4128 * sysctl handler for numa_zonelist_order
4130 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
4131 void __user
*buffer
, size_t *length
,
4134 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
4136 static DEFINE_MUTEX(zl_order_mutex
);
4138 mutex_lock(&zl_order_mutex
);
4140 if (strlen((char *)table
->data
) >= NUMA_ZONELIST_ORDER_LEN
) {
4144 strcpy(saved_string
, (char *)table
->data
);
4146 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
4150 int oldval
= user_zonelist_order
;
4152 ret
= __parse_numa_zonelist_order((char *)table
->data
);
4155 * bogus value. restore saved string
4157 strncpy((char *)table
->data
, saved_string
,
4158 NUMA_ZONELIST_ORDER_LEN
);
4159 user_zonelist_order
= oldval
;
4160 } else if (oldval
!= user_zonelist_order
) {
4161 mutex_lock(&zonelists_mutex
);
4162 build_all_zonelists(NULL
, NULL
);
4163 mutex_unlock(&zonelists_mutex
);
4167 mutex_unlock(&zl_order_mutex
);
4172 #define MAX_NODE_LOAD (nr_online_nodes)
4173 static int node_load
[MAX_NUMNODES
];
4176 * find_next_best_node - find the next node that should appear in a given node's fallback list
4177 * @node: node whose fallback list we're appending
4178 * @used_node_mask: nodemask_t of already used nodes
4180 * We use a number of factors to determine which is the next node that should
4181 * appear on a given node's fallback list. The node should not have appeared
4182 * already in @node's fallback list, and it should be the next closest node
4183 * according to the distance array (which contains arbitrary distance values
4184 * from each node to each node in the system), and should also prefer nodes
4185 * with no CPUs, since presumably they'll have very little allocation pressure
4186 * on them otherwise.
4187 * It returns -1 if no node is found.
4189 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
4192 int min_val
= INT_MAX
;
4193 int best_node
= NUMA_NO_NODE
;
4194 const struct cpumask
*tmp
= cpumask_of_node(0);
4196 /* Use the local node if we haven't already */
4197 if (!node_isset(node
, *used_node_mask
)) {
4198 node_set(node
, *used_node_mask
);
4202 for_each_node_state(n
, N_MEMORY
) {
4204 /* Don't want a node to appear more than once */
4205 if (node_isset(n
, *used_node_mask
))
4208 /* Use the distance array to find the distance */
4209 val
= node_distance(node
, n
);
4211 /* Penalize nodes under us ("prefer the next node") */
4214 /* Give preference to headless and unused nodes */
4215 tmp
= cpumask_of_node(n
);
4216 if (!cpumask_empty(tmp
))
4217 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
4219 /* Slight preference for less loaded node */
4220 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
4221 val
+= node_load
[n
];
4223 if (val
< min_val
) {
4230 node_set(best_node
, *used_node_mask
);
4237 * Build zonelists ordered by node and zones within node.
4238 * This results in maximum locality--normal zone overflows into local
4239 * DMA zone, if any--but risks exhausting DMA zone.
4241 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
4244 struct zonelist
*zonelist
;
4246 zonelist
= &pgdat
->node_zonelists
[0];
4247 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
4249 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4250 zonelist
->_zonerefs
[j
].zone
= NULL
;
4251 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4255 * Build gfp_thisnode zonelists
4257 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
4260 struct zonelist
*zonelist
;
4262 zonelist
= &pgdat
->node_zonelists
[1];
4263 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4264 zonelist
->_zonerefs
[j
].zone
= NULL
;
4265 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4269 * Build zonelists ordered by zone and nodes within zones.
4270 * This results in conserving DMA zone[s] until all Normal memory is
4271 * exhausted, but results in overflowing to remote node while memory
4272 * may still exist in local DMA zone.
4274 static int node_order
[MAX_NUMNODES
];
4276 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
4279 int zone_type
; /* needs to be signed */
4281 struct zonelist
*zonelist
;
4283 zonelist
= &pgdat
->node_zonelists
[0];
4285 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
4286 for (j
= 0; j
< nr_nodes
; j
++) {
4287 node
= node_order
[j
];
4288 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
4289 if (populated_zone(z
)) {
4291 &zonelist
->_zonerefs
[pos
++]);
4292 check_highest_zone(zone_type
);
4296 zonelist
->_zonerefs
[pos
].zone
= NULL
;
4297 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
4300 #if defined(CONFIG_64BIT)
4302 * Devices that require DMA32/DMA are relatively rare and do not justify a
4303 * penalty to every machine in case the specialised case applies. Default
4304 * to Node-ordering on 64-bit NUMA machines
4306 static int default_zonelist_order(void)
4308 return ZONELIST_ORDER_NODE
;
4312 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4313 * by the kernel. If processes running on node 0 deplete the low memory zone
4314 * then reclaim will occur more frequency increasing stalls and potentially
4315 * be easier to OOM if a large percentage of the zone is under writeback or
4316 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4317 * Hence, default to zone ordering on 32-bit.
4319 static int default_zonelist_order(void)
4321 return ZONELIST_ORDER_ZONE
;
4323 #endif /* CONFIG_64BIT */
4325 static void set_zonelist_order(void)
4327 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
4328 current_zonelist_order
= default_zonelist_order();
4330 current_zonelist_order
= user_zonelist_order
;
4333 static void build_zonelists(pg_data_t
*pgdat
)
4336 nodemask_t used_mask
;
4337 int local_node
, prev_node
;
4338 struct zonelist
*zonelist
;
4339 unsigned int order
= current_zonelist_order
;
4341 /* initialize zonelists */
4342 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
4343 zonelist
= pgdat
->node_zonelists
+ i
;
4344 zonelist
->_zonerefs
[0].zone
= NULL
;
4345 zonelist
->_zonerefs
[0].zone_idx
= 0;
4348 /* NUMA-aware ordering of nodes */
4349 local_node
= pgdat
->node_id
;
4350 load
= nr_online_nodes
;
4351 prev_node
= local_node
;
4352 nodes_clear(used_mask
);
4354 memset(node_order
, 0, sizeof(node_order
));
4357 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
4359 * We don't want to pressure a particular node.
4360 * So adding penalty to the first node in same
4361 * distance group to make it round-robin.
4363 if (node_distance(local_node
, node
) !=
4364 node_distance(local_node
, prev_node
))
4365 node_load
[node
] = load
;
4369 if (order
== ZONELIST_ORDER_NODE
)
4370 build_zonelists_in_node_order(pgdat
, node
);
4372 node_order
[i
++] = node
; /* remember order */
4375 if (order
== ZONELIST_ORDER_ZONE
) {
4376 /* calculate node order -- i.e., DMA last! */
4377 build_zonelists_in_zone_order(pgdat
, i
);
4380 build_thisnode_zonelists(pgdat
);
4383 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4385 * Return node id of node used for "local" allocations.
4386 * I.e., first node id of first zone in arg node's generic zonelist.
4387 * Used for initializing percpu 'numa_mem', which is used primarily
4388 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4390 int local_memory_node(int node
)
4394 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
4395 gfp_zone(GFP_KERNEL
),
4402 #else /* CONFIG_NUMA */
4404 static void set_zonelist_order(void)
4406 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
4409 static void build_zonelists(pg_data_t
*pgdat
)
4411 int node
, local_node
;
4413 struct zonelist
*zonelist
;
4415 local_node
= pgdat
->node_id
;
4417 zonelist
= &pgdat
->node_zonelists
[0];
4418 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4421 * Now we build the zonelist so that it contains the zones
4422 * of all the other nodes.
4423 * We don't want to pressure a particular node, so when
4424 * building the zones for node N, we make sure that the
4425 * zones coming right after the local ones are those from
4426 * node N+1 (modulo N)
4428 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
4429 if (!node_online(node
))
4431 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4433 for (node
= 0; node
< local_node
; node
++) {
4434 if (!node_online(node
))
4436 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4439 zonelist
->_zonerefs
[j
].zone
= NULL
;
4440 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4443 #endif /* CONFIG_NUMA */
4446 * Boot pageset table. One per cpu which is going to be used for all
4447 * zones and all nodes. The parameters will be set in such a way
4448 * that an item put on a list will immediately be handed over to
4449 * the buddy list. This is safe since pageset manipulation is done
4450 * with interrupts disabled.
4452 * The boot_pagesets must be kept even after bootup is complete for
4453 * unused processors and/or zones. They do play a role for bootstrapping
4454 * hotplugged processors.
4456 * zoneinfo_show() and maybe other functions do
4457 * not check if the processor is online before following the pageset pointer.
4458 * Other parts of the kernel may not check if the zone is available.
4460 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
4461 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
4462 static void setup_zone_pageset(struct zone
*zone
);
4465 * Global mutex to protect against size modification of zonelists
4466 * as well as to serialize pageset setup for the new populated zone.
4468 DEFINE_MUTEX(zonelists_mutex
);
4470 /* return values int ....just for stop_machine() */
4471 static int __build_all_zonelists(void *data
)
4475 pg_data_t
*self
= data
;
4478 memset(node_load
, 0, sizeof(node_load
));
4481 if (self
&& !node_online(self
->node_id
)) {
4482 build_zonelists(self
);
4485 for_each_online_node(nid
) {
4486 pg_data_t
*pgdat
= NODE_DATA(nid
);
4488 build_zonelists(pgdat
);
4492 * Initialize the boot_pagesets that are going to be used
4493 * for bootstrapping processors. The real pagesets for
4494 * each zone will be allocated later when the per cpu
4495 * allocator is available.
4497 * boot_pagesets are used also for bootstrapping offline
4498 * cpus if the system is already booted because the pagesets
4499 * are needed to initialize allocators on a specific cpu too.
4500 * F.e. the percpu allocator needs the page allocator which
4501 * needs the percpu allocator in order to allocate its pagesets
4502 * (a chicken-egg dilemma).
4504 for_each_possible_cpu(cpu
) {
4505 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
4507 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4509 * We now know the "local memory node" for each node--
4510 * i.e., the node of the first zone in the generic zonelist.
4511 * Set up numa_mem percpu variable for on-line cpus. During
4512 * boot, only the boot cpu should be on-line; we'll init the
4513 * secondary cpus' numa_mem as they come on-line. During
4514 * node/memory hotplug, we'll fixup all on-line cpus.
4516 if (cpu_online(cpu
))
4517 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
4524 static noinline
void __init
4525 build_all_zonelists_init(void)
4527 __build_all_zonelists(NULL
);
4528 mminit_verify_zonelist();
4529 cpuset_init_current_mems_allowed();
4533 * Called with zonelists_mutex held always
4534 * unless system_state == SYSTEM_BOOTING.
4536 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4537 * [we're only called with non-NULL zone through __meminit paths] and
4538 * (2) call of __init annotated helper build_all_zonelists_init
4539 * [protected by SYSTEM_BOOTING].
4541 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
4543 set_zonelist_order();
4545 if (system_state
== SYSTEM_BOOTING
) {
4546 build_all_zonelists_init();
4548 #ifdef CONFIG_MEMORY_HOTPLUG
4550 setup_zone_pageset(zone
);
4552 /* we have to stop all cpus to guarantee there is no user
4554 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
4555 /* cpuset refresh routine should be here */
4557 vm_total_pages
= nr_free_pagecache_pages();
4559 * Disable grouping by mobility if the number of pages in the
4560 * system is too low to allow the mechanism to work. It would be
4561 * more accurate, but expensive to check per-zone. This check is
4562 * made on memory-hotadd so a system can start with mobility
4563 * disabled and enable it later
4565 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
4566 page_group_by_mobility_disabled
= 1;
4568 page_group_by_mobility_disabled
= 0;
4570 pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n",
4572 zonelist_order_name
[current_zonelist_order
],
4573 page_group_by_mobility_disabled
? "off" : "on",
4576 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
4581 * Helper functions to size the waitqueue hash table.
4582 * Essentially these want to choose hash table sizes sufficiently
4583 * large so that collisions trying to wait on pages are rare.
4584 * But in fact, the number of active page waitqueues on typical
4585 * systems is ridiculously low, less than 200. So this is even
4586 * conservative, even though it seems large.
4588 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
4589 * waitqueues, i.e. the size of the waitq table given the number of pages.
4591 #define PAGES_PER_WAITQUEUE 256
4593 #ifndef CONFIG_MEMORY_HOTPLUG
4594 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
4596 unsigned long size
= 1;
4598 pages
/= PAGES_PER_WAITQUEUE
;
4600 while (size
< pages
)
4604 * Once we have dozens or even hundreds of threads sleeping
4605 * on IO we've got bigger problems than wait queue collision.
4606 * Limit the size of the wait table to a reasonable size.
4608 size
= min(size
, 4096UL);
4610 return max(size
, 4UL);
4614 * A zone's size might be changed by hot-add, so it is not possible to determine
4615 * a suitable size for its wait_table. So we use the maximum size now.
4617 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
4619 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
4620 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
4621 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
4623 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
4624 * or more by the traditional way. (See above). It equals:
4626 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
4627 * ia64(16K page size) : = ( 8G + 4M)byte.
4628 * powerpc (64K page size) : = (32G +16M)byte.
4630 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
4637 * This is an integer logarithm so that shifts can be used later
4638 * to extract the more random high bits from the multiplicative
4639 * hash function before the remainder is taken.
4641 static inline unsigned long wait_table_bits(unsigned long size
)
4647 * Initially all pages are reserved - free ones are freed
4648 * up by free_all_bootmem() once the early boot process is
4649 * done. Non-atomic initialization, single-pass.
4651 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
4652 unsigned long start_pfn
, enum memmap_context context
)
4654 struct vmem_altmap
*altmap
= to_vmem_altmap(__pfn_to_phys(start_pfn
));
4655 unsigned long end_pfn
= start_pfn
+ size
;
4656 pg_data_t
*pgdat
= NODE_DATA(nid
);
4658 unsigned long nr_initialised
= 0;
4659 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4660 struct memblock_region
*r
= NULL
, *tmp
;
4663 if (highest_memmap_pfn
< end_pfn
- 1)
4664 highest_memmap_pfn
= end_pfn
- 1;
4667 * Honor reservation requested by the driver for this ZONE_DEVICE
4670 if (altmap
&& start_pfn
== altmap
->base_pfn
)
4671 start_pfn
+= altmap
->reserve
;
4673 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
4675 * There can be holes in boot-time mem_map[]s handed to this
4676 * function. They do not exist on hotplugged memory.
4678 if (context
!= MEMMAP_EARLY
)
4681 if (!early_pfn_valid(pfn
))
4683 if (!early_pfn_in_nid(pfn
, nid
))
4685 if (!update_defer_init(pgdat
, pfn
, end_pfn
, &nr_initialised
))
4688 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4690 * If not mirrored_kernelcore and ZONE_MOVABLE exists, range
4691 * from zone_movable_pfn[nid] to end of each node should be
4692 * ZONE_MOVABLE not ZONE_NORMAL. skip it.
4694 if (!mirrored_kernelcore
&& zone_movable_pfn
[nid
])
4695 if (zone
== ZONE_NORMAL
&& pfn
>= zone_movable_pfn
[nid
])
4699 * Check given memblock attribute by firmware which can affect
4700 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
4701 * mirrored, it's an overlapped memmap init. skip it.
4703 if (mirrored_kernelcore
&& zone
== ZONE_MOVABLE
) {
4704 if (!r
|| pfn
>= memblock_region_memory_end_pfn(r
)) {
4705 for_each_memblock(memory
, tmp
)
4706 if (pfn
< memblock_region_memory_end_pfn(tmp
))
4710 if (pfn
>= memblock_region_memory_base_pfn(r
) &&
4711 memblock_is_mirror(r
)) {
4712 /* already initialized as NORMAL */
4713 pfn
= memblock_region_memory_end_pfn(r
);
4721 * Mark the block movable so that blocks are reserved for
4722 * movable at startup. This will force kernel allocations
4723 * to reserve their blocks rather than leaking throughout
4724 * the address space during boot when many long-lived
4725 * kernel allocations are made.
4727 * bitmap is created for zone's valid pfn range. but memmap
4728 * can be created for invalid pages (for alignment)
4729 * check here not to call set_pageblock_migratetype() against
4732 if (!(pfn
& (pageblock_nr_pages
- 1))) {
4733 struct page
*page
= pfn_to_page(pfn
);
4735 __init_single_page(page
, pfn
, zone
, nid
);
4736 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4738 __init_single_pfn(pfn
, zone
, nid
);
4743 static void __meminit
zone_init_free_lists(struct zone
*zone
)
4745 unsigned int order
, t
;
4746 for_each_migratetype_order(order
, t
) {
4747 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
4748 zone
->free_area
[order
].nr_free
= 0;
4752 #ifndef __HAVE_ARCH_MEMMAP_INIT
4753 #define memmap_init(size, nid, zone, start_pfn) \
4754 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4757 static int zone_batchsize(struct zone
*zone
)
4763 * The per-cpu-pages pools are set to around 1000th of the
4764 * size of the zone. But no more than 1/2 of a meg.
4766 * OK, so we don't know how big the cache is. So guess.
4768 batch
= zone
->managed_pages
/ 1024;
4769 if (batch
* PAGE_SIZE
> 512 * 1024)
4770 batch
= (512 * 1024) / PAGE_SIZE
;
4771 batch
/= 4; /* We effectively *= 4 below */
4776 * Clamp the batch to a 2^n - 1 value. Having a power
4777 * of 2 value was found to be more likely to have
4778 * suboptimal cache aliasing properties in some cases.
4780 * For example if 2 tasks are alternately allocating
4781 * batches of pages, one task can end up with a lot
4782 * of pages of one half of the possible page colors
4783 * and the other with pages of the other colors.
4785 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
4790 /* The deferral and batching of frees should be suppressed under NOMMU
4793 * The problem is that NOMMU needs to be able to allocate large chunks
4794 * of contiguous memory as there's no hardware page translation to
4795 * assemble apparent contiguous memory from discontiguous pages.
4797 * Queueing large contiguous runs of pages for batching, however,
4798 * causes the pages to actually be freed in smaller chunks. As there
4799 * can be a significant delay between the individual batches being
4800 * recycled, this leads to the once large chunks of space being
4801 * fragmented and becoming unavailable for high-order allocations.
4808 * pcp->high and pcp->batch values are related and dependent on one another:
4809 * ->batch must never be higher then ->high.
4810 * The following function updates them in a safe manner without read side
4813 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4814 * those fields changing asynchronously (acording the the above rule).
4816 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4817 * outside of boot time (or some other assurance that no concurrent updaters
4820 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
4821 unsigned long batch
)
4823 /* start with a fail safe value for batch */
4827 /* Update high, then batch, in order */
4834 /* a companion to pageset_set_high() */
4835 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
4837 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
4840 static void pageset_init(struct per_cpu_pageset
*p
)
4842 struct per_cpu_pages
*pcp
;
4845 memset(p
, 0, sizeof(*p
));
4849 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
4850 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
4853 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
4856 pageset_set_batch(p
, batch
);
4860 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4861 * to the value high for the pageset p.
4863 static void pageset_set_high(struct per_cpu_pageset
*p
,
4866 unsigned long batch
= max(1UL, high
/ 4);
4867 if ((high
/ 4) > (PAGE_SHIFT
* 8))
4868 batch
= PAGE_SHIFT
* 8;
4870 pageset_update(&p
->pcp
, high
, batch
);
4873 static void pageset_set_high_and_batch(struct zone
*zone
,
4874 struct per_cpu_pageset
*pcp
)
4876 if (percpu_pagelist_fraction
)
4877 pageset_set_high(pcp
,
4878 (zone
->managed_pages
/
4879 percpu_pagelist_fraction
));
4881 pageset_set_batch(pcp
, zone_batchsize(zone
));
4884 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
4886 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
4889 pageset_set_high_and_batch(zone
, pcp
);
4892 static void __meminit
setup_zone_pageset(struct zone
*zone
)
4895 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
4896 for_each_possible_cpu(cpu
)
4897 zone_pageset_init(zone
, cpu
);
4901 * Allocate per cpu pagesets and initialize them.
4902 * Before this call only boot pagesets were available.
4904 void __init
setup_per_cpu_pageset(void)
4908 for_each_populated_zone(zone
)
4909 setup_zone_pageset(zone
);
4912 static noinline __init_refok
4913 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
4919 * The per-page waitqueue mechanism uses hashed waitqueues
4922 zone
->wait_table_hash_nr_entries
=
4923 wait_table_hash_nr_entries(zone_size_pages
);
4924 zone
->wait_table_bits
=
4925 wait_table_bits(zone
->wait_table_hash_nr_entries
);
4926 alloc_size
= zone
->wait_table_hash_nr_entries
4927 * sizeof(wait_queue_head_t
);
4929 if (!slab_is_available()) {
4930 zone
->wait_table
= (wait_queue_head_t
*)
4931 memblock_virt_alloc_node_nopanic(
4932 alloc_size
, zone
->zone_pgdat
->node_id
);
4935 * This case means that a zone whose size was 0 gets new memory
4936 * via memory hot-add.
4937 * But it may be the case that a new node was hot-added. In
4938 * this case vmalloc() will not be able to use this new node's
4939 * memory - this wait_table must be initialized to use this new
4940 * node itself as well.
4941 * To use this new node's memory, further consideration will be
4944 zone
->wait_table
= vmalloc(alloc_size
);
4946 if (!zone
->wait_table
)
4949 for (i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
4950 init_waitqueue_head(zone
->wait_table
+ i
);
4955 static __meminit
void zone_pcp_init(struct zone
*zone
)
4958 * per cpu subsystem is not up at this point. The following code
4959 * relies on the ability of the linker to provide the
4960 * offset of a (static) per cpu variable into the per cpu area.
4962 zone
->pageset
= &boot_pageset
;
4964 if (populated_zone(zone
))
4965 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
4966 zone
->name
, zone
->present_pages
,
4967 zone_batchsize(zone
));
4970 int __meminit
init_currently_empty_zone(struct zone
*zone
,
4971 unsigned long zone_start_pfn
,
4974 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
4976 ret
= zone_wait_table_init(zone
, size
);
4979 pgdat
->nr_zones
= zone_idx(zone
) + 1;
4981 zone
->zone_start_pfn
= zone_start_pfn
;
4983 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
4984 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4986 (unsigned long)zone_idx(zone
),
4987 zone_start_pfn
, (zone_start_pfn
+ size
));
4989 zone_init_free_lists(zone
);
4994 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4995 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4998 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5000 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
5001 struct mminit_pfnnid_cache
*state
)
5003 unsigned long start_pfn
, end_pfn
;
5006 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
5007 return state
->last_nid
;
5009 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
5011 state
->last_start
= start_pfn
;
5012 state
->last_end
= end_pfn
;
5013 state
->last_nid
= nid
;
5018 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5021 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5022 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5023 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5025 * If an architecture guarantees that all ranges registered contain no holes
5026 * and may be freed, this this function may be used instead of calling
5027 * memblock_free_early_nid() manually.
5029 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
5031 unsigned long start_pfn
, end_pfn
;
5034 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
5035 start_pfn
= min(start_pfn
, max_low_pfn
);
5036 end_pfn
= min(end_pfn
, max_low_pfn
);
5038 if (start_pfn
< end_pfn
)
5039 memblock_free_early_nid(PFN_PHYS(start_pfn
),
5040 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
5046 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5047 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5049 * If an architecture guarantees that all ranges registered contain no holes and may
5050 * be freed, this function may be used instead of calling memory_present() manually.
5052 void __init
sparse_memory_present_with_active_regions(int nid
)
5054 unsigned long start_pfn
, end_pfn
;
5057 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
5058 memory_present(this_nid
, start_pfn
, end_pfn
);
5062 * get_pfn_range_for_nid - Return the start and end page frames for a node
5063 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5064 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5065 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5067 * It returns the start and end page frame of a node based on information
5068 * provided by memblock_set_node(). If called for a node
5069 * with no available memory, a warning is printed and the start and end
5072 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
5073 unsigned long *start_pfn
, unsigned long *end_pfn
)
5075 unsigned long this_start_pfn
, this_end_pfn
;
5081 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
5082 *start_pfn
= min(*start_pfn
, this_start_pfn
);
5083 *end_pfn
= max(*end_pfn
, this_end_pfn
);
5086 if (*start_pfn
== -1UL)
5091 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5092 * assumption is made that zones within a node are ordered in monotonic
5093 * increasing memory addresses so that the "highest" populated zone is used
5095 static void __init
find_usable_zone_for_movable(void)
5098 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
5099 if (zone_index
== ZONE_MOVABLE
)
5102 if (arch_zone_highest_possible_pfn
[zone_index
] >
5103 arch_zone_lowest_possible_pfn
[zone_index
])
5107 VM_BUG_ON(zone_index
== -1);
5108 movable_zone
= zone_index
;
5112 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5113 * because it is sized independent of architecture. Unlike the other zones,
5114 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5115 * in each node depending on the size of each node and how evenly kernelcore
5116 * is distributed. This helper function adjusts the zone ranges
5117 * provided by the architecture for a given node by using the end of the
5118 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5119 * zones within a node are in order of monotonic increases memory addresses
5121 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
5122 unsigned long zone_type
,
5123 unsigned long node_start_pfn
,
5124 unsigned long node_end_pfn
,
5125 unsigned long *zone_start_pfn
,
5126 unsigned long *zone_end_pfn
)
5128 /* Only adjust if ZONE_MOVABLE is on this node */
5129 if (zone_movable_pfn
[nid
]) {
5130 /* Size ZONE_MOVABLE */
5131 if (zone_type
== ZONE_MOVABLE
) {
5132 *zone_start_pfn
= zone_movable_pfn
[nid
];
5133 *zone_end_pfn
= min(node_end_pfn
,
5134 arch_zone_highest_possible_pfn
[movable_zone
]);
5136 /* Check if this whole range is within ZONE_MOVABLE */
5137 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
5138 *zone_start_pfn
= *zone_end_pfn
;
5143 * Return the number of pages a zone spans in a node, including holes
5144 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5146 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5147 unsigned long zone_type
,
5148 unsigned long node_start_pfn
,
5149 unsigned long node_end_pfn
,
5150 unsigned long *zone_start_pfn
,
5151 unsigned long *zone_end_pfn
,
5152 unsigned long *ignored
)
5154 /* When hotadd a new node from cpu_up(), the node should be empty */
5155 if (!node_start_pfn
&& !node_end_pfn
)
5158 /* Get the start and end of the zone */
5159 *zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
5160 *zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
5161 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5162 node_start_pfn
, node_end_pfn
,
5163 zone_start_pfn
, zone_end_pfn
);
5165 /* Check that this node has pages within the zone's required range */
5166 if (*zone_end_pfn
< node_start_pfn
|| *zone_start_pfn
> node_end_pfn
)
5169 /* Move the zone boundaries inside the node if necessary */
5170 *zone_end_pfn
= min(*zone_end_pfn
, node_end_pfn
);
5171 *zone_start_pfn
= max(*zone_start_pfn
, node_start_pfn
);
5173 /* Return the spanned pages */
5174 return *zone_end_pfn
- *zone_start_pfn
;
5178 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5179 * then all holes in the requested range will be accounted for.
5181 unsigned long __meminit
__absent_pages_in_range(int nid
,
5182 unsigned long range_start_pfn
,
5183 unsigned long range_end_pfn
)
5185 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
5186 unsigned long start_pfn
, end_pfn
;
5189 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5190 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
5191 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
5192 nr_absent
-= end_pfn
- start_pfn
;
5198 * absent_pages_in_range - Return number of page frames in holes within a range
5199 * @start_pfn: The start PFN to start searching for holes
5200 * @end_pfn: The end PFN to stop searching for holes
5202 * It returns the number of pages frames in memory holes within a range.
5204 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
5205 unsigned long end_pfn
)
5207 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
5210 /* Return the number of page frames in holes in a zone on a node */
5211 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5212 unsigned long zone_type
,
5213 unsigned long node_start_pfn
,
5214 unsigned long node_end_pfn
,
5215 unsigned long *ignored
)
5217 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
5218 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
5219 unsigned long zone_start_pfn
, zone_end_pfn
;
5220 unsigned long nr_absent
;
5222 /* When hotadd a new node from cpu_up(), the node should be empty */
5223 if (!node_start_pfn
&& !node_end_pfn
)
5226 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
5227 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
5229 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5230 node_start_pfn
, node_end_pfn
,
5231 &zone_start_pfn
, &zone_end_pfn
);
5232 nr_absent
= __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
5235 * ZONE_MOVABLE handling.
5236 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5239 if (zone_movable_pfn
[nid
]) {
5240 if (mirrored_kernelcore
) {
5241 unsigned long start_pfn
, end_pfn
;
5242 struct memblock_region
*r
;
5244 for_each_memblock(memory
, r
) {
5245 start_pfn
= clamp(memblock_region_memory_base_pfn(r
),
5246 zone_start_pfn
, zone_end_pfn
);
5247 end_pfn
= clamp(memblock_region_memory_end_pfn(r
),
5248 zone_start_pfn
, zone_end_pfn
);
5250 if (zone_type
== ZONE_MOVABLE
&&
5251 memblock_is_mirror(r
))
5252 nr_absent
+= end_pfn
- start_pfn
;
5254 if (zone_type
== ZONE_NORMAL
&&
5255 !memblock_is_mirror(r
))
5256 nr_absent
+= end_pfn
- start_pfn
;
5259 if (zone_type
== ZONE_NORMAL
)
5260 nr_absent
+= node_end_pfn
- zone_movable_pfn
[nid
];
5267 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5268 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5269 unsigned long zone_type
,
5270 unsigned long node_start_pfn
,
5271 unsigned long node_end_pfn
,
5272 unsigned long *zone_start_pfn
,
5273 unsigned long *zone_end_pfn
,
5274 unsigned long *zones_size
)
5278 *zone_start_pfn
= node_start_pfn
;
5279 for (zone
= 0; zone
< zone_type
; zone
++)
5280 *zone_start_pfn
+= zones_size
[zone
];
5282 *zone_end_pfn
= *zone_start_pfn
+ zones_size
[zone_type
];
5284 return zones_size
[zone_type
];
5287 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5288 unsigned long zone_type
,
5289 unsigned long node_start_pfn
,
5290 unsigned long node_end_pfn
,
5291 unsigned long *zholes_size
)
5296 return zholes_size
[zone_type
];
5299 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5301 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
5302 unsigned long node_start_pfn
,
5303 unsigned long node_end_pfn
,
5304 unsigned long *zones_size
,
5305 unsigned long *zholes_size
)
5307 unsigned long realtotalpages
= 0, totalpages
= 0;
5310 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5311 struct zone
*zone
= pgdat
->node_zones
+ i
;
5312 unsigned long zone_start_pfn
, zone_end_pfn
;
5313 unsigned long size
, real_size
;
5315 size
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
5321 real_size
= size
- zone_absent_pages_in_node(pgdat
->node_id
, i
,
5322 node_start_pfn
, node_end_pfn
,
5325 zone
->zone_start_pfn
= zone_start_pfn
;
5327 zone
->zone_start_pfn
= 0;
5328 zone
->spanned_pages
= size
;
5329 zone
->present_pages
= real_size
;
5332 realtotalpages
+= real_size
;
5335 pgdat
->node_spanned_pages
= totalpages
;
5336 pgdat
->node_present_pages
= realtotalpages
;
5337 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
5341 #ifndef CONFIG_SPARSEMEM
5343 * Calculate the size of the zone->blockflags rounded to an unsigned long
5344 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5345 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5346 * round what is now in bits to nearest long in bits, then return it in
5349 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
5351 unsigned long usemapsize
;
5353 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
5354 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
5355 usemapsize
= usemapsize
>> pageblock_order
;
5356 usemapsize
*= NR_PAGEBLOCK_BITS
;
5357 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
5359 return usemapsize
/ 8;
5362 static void __init
setup_usemap(struct pglist_data
*pgdat
,
5364 unsigned long zone_start_pfn
,
5365 unsigned long zonesize
)
5367 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
5368 zone
->pageblock_flags
= NULL
;
5370 zone
->pageblock_flags
=
5371 memblock_virt_alloc_node_nopanic(usemapsize
,
5375 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
5376 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
5377 #endif /* CONFIG_SPARSEMEM */
5379 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5381 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5382 void __paginginit
set_pageblock_order(void)
5386 /* Check that pageblock_nr_pages has not already been setup */
5387 if (pageblock_order
)
5390 if (HPAGE_SHIFT
> PAGE_SHIFT
)
5391 order
= HUGETLB_PAGE_ORDER
;
5393 order
= MAX_ORDER
- 1;
5396 * Assume the largest contiguous order of interest is a huge page.
5397 * This value may be variable depending on boot parameters on IA64 and
5400 pageblock_order
= order
;
5402 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5405 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5406 * is unused as pageblock_order is set at compile-time. See
5407 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5410 void __paginginit
set_pageblock_order(void)
5414 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5416 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
5417 unsigned long present_pages
)
5419 unsigned long pages
= spanned_pages
;
5422 * Provide a more accurate estimation if there are holes within
5423 * the zone and SPARSEMEM is in use. If there are holes within the
5424 * zone, each populated memory region may cost us one or two extra
5425 * memmap pages due to alignment because memmap pages for each
5426 * populated regions may not naturally algined on page boundary.
5427 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5429 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
5430 IS_ENABLED(CONFIG_SPARSEMEM
))
5431 pages
= present_pages
;
5433 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
5437 * Set up the zone data structures:
5438 * - mark all pages reserved
5439 * - mark all memory queues empty
5440 * - clear the memory bitmaps
5442 * NOTE: pgdat should get zeroed by caller.
5444 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
)
5447 int nid
= pgdat
->node_id
;
5450 pgdat_resize_init(pgdat
);
5451 #ifdef CONFIG_NUMA_BALANCING
5452 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
5453 pgdat
->numabalancing_migrate_nr_pages
= 0;
5454 pgdat
->numabalancing_migrate_next_window
= jiffies
;
5456 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5457 spin_lock_init(&pgdat
->split_queue_lock
);
5458 INIT_LIST_HEAD(&pgdat
->split_queue
);
5459 pgdat
->split_queue_len
= 0;
5461 init_waitqueue_head(&pgdat
->kswapd_wait
);
5462 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
5463 #ifdef CONFIG_COMPACTION
5464 init_waitqueue_head(&pgdat
->kcompactd_wait
);
5466 pgdat_page_ext_init(pgdat
);
5468 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5469 struct zone
*zone
= pgdat
->node_zones
+ j
;
5470 unsigned long size
, realsize
, freesize
, memmap_pages
;
5471 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
5473 size
= zone
->spanned_pages
;
5474 realsize
= freesize
= zone
->present_pages
;
5477 * Adjust freesize so that it accounts for how much memory
5478 * is used by this zone for memmap. This affects the watermark
5479 * and per-cpu initialisations
5481 memmap_pages
= calc_memmap_size(size
, realsize
);
5482 if (!is_highmem_idx(j
)) {
5483 if (freesize
>= memmap_pages
) {
5484 freesize
-= memmap_pages
;
5487 " %s zone: %lu pages used for memmap\n",
5488 zone_names
[j
], memmap_pages
);
5490 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
5491 zone_names
[j
], memmap_pages
, freesize
);
5494 /* Account for reserved pages */
5495 if (j
== 0 && freesize
> dma_reserve
) {
5496 freesize
-= dma_reserve
;
5497 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
5498 zone_names
[0], dma_reserve
);
5501 if (!is_highmem_idx(j
))
5502 nr_kernel_pages
+= freesize
;
5503 /* Charge for highmem memmap if there are enough kernel pages */
5504 else if (nr_kernel_pages
> memmap_pages
* 2)
5505 nr_kernel_pages
-= memmap_pages
;
5506 nr_all_pages
+= freesize
;
5509 * Set an approximate value for lowmem here, it will be adjusted
5510 * when the bootmem allocator frees pages into the buddy system.
5511 * And all highmem pages will be managed by the buddy system.
5513 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
5516 zone
->min_unmapped_pages
= (freesize
*sysctl_min_unmapped_ratio
)
5518 zone
->min_slab_pages
= (freesize
* sysctl_min_slab_ratio
) / 100;
5520 zone
->name
= zone_names
[j
];
5521 spin_lock_init(&zone
->lock
);
5522 spin_lock_init(&zone
->lru_lock
);
5523 zone_seqlock_init(zone
);
5524 zone
->zone_pgdat
= pgdat
;
5525 zone_pcp_init(zone
);
5527 /* For bootup, initialized properly in watermark setup */
5528 mod_zone_page_state(zone
, NR_ALLOC_BATCH
, zone
->managed_pages
);
5530 lruvec_init(&zone
->lruvec
);
5534 set_pageblock_order();
5535 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
5536 ret
= init_currently_empty_zone(zone
, zone_start_pfn
, size
);
5538 memmap_init(size
, nid
, j
, zone_start_pfn
);
5542 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
5544 unsigned long __maybe_unused start
= 0;
5545 unsigned long __maybe_unused offset
= 0;
5547 /* Skip empty nodes */
5548 if (!pgdat
->node_spanned_pages
)
5551 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5552 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
5553 offset
= pgdat
->node_start_pfn
- start
;
5554 /* ia64 gets its own node_mem_map, before this, without bootmem */
5555 if (!pgdat
->node_mem_map
) {
5556 unsigned long size
, end
;
5560 * The zone's endpoints aren't required to be MAX_ORDER
5561 * aligned but the node_mem_map endpoints must be in order
5562 * for the buddy allocator to function correctly.
5564 end
= pgdat_end_pfn(pgdat
);
5565 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
5566 size
= (end
- start
) * sizeof(struct page
);
5567 map
= alloc_remap(pgdat
->node_id
, size
);
5569 map
= memblock_virt_alloc_node_nopanic(size
,
5571 pgdat
->node_mem_map
= map
+ offset
;
5573 #ifndef CONFIG_NEED_MULTIPLE_NODES
5575 * With no DISCONTIG, the global mem_map is just set as node 0's
5577 if (pgdat
== NODE_DATA(0)) {
5578 mem_map
= NODE_DATA(0)->node_mem_map
;
5579 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
5580 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
5582 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5585 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
5588 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
5589 unsigned long node_start_pfn
, unsigned long *zholes_size
)
5591 pg_data_t
*pgdat
= NODE_DATA(nid
);
5592 unsigned long start_pfn
= 0;
5593 unsigned long end_pfn
= 0;
5595 /* pg_data_t should be reset to zero when it's allocated */
5596 WARN_ON(pgdat
->nr_zones
|| pgdat
->classzone_idx
);
5598 reset_deferred_meminit(pgdat
);
5599 pgdat
->node_id
= nid
;
5600 pgdat
->node_start_pfn
= node_start_pfn
;
5601 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5602 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
5603 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
5604 (u64
)start_pfn
<< PAGE_SHIFT
,
5605 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
5607 start_pfn
= node_start_pfn
;
5609 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
5610 zones_size
, zholes_size
);
5612 alloc_node_mem_map(pgdat
);
5613 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5614 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
5615 nid
, (unsigned long)pgdat
,
5616 (unsigned long)pgdat
->node_mem_map
);
5619 free_area_init_core(pgdat
);
5622 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5624 #if MAX_NUMNODES > 1
5626 * Figure out the number of possible node ids.
5628 void __init
setup_nr_node_ids(void)
5630 unsigned int highest
;
5632 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
5633 nr_node_ids
= highest
+ 1;
5638 * node_map_pfn_alignment - determine the maximum internode alignment
5640 * This function should be called after node map is populated and sorted.
5641 * It calculates the maximum power of two alignment which can distinguish
5644 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5645 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5646 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5647 * shifted, 1GiB is enough and this function will indicate so.
5649 * This is used to test whether pfn -> nid mapping of the chosen memory
5650 * model has fine enough granularity to avoid incorrect mapping for the
5651 * populated node map.
5653 * Returns the determined alignment in pfn's. 0 if there is no alignment
5654 * requirement (single node).
5656 unsigned long __init
node_map_pfn_alignment(void)
5658 unsigned long accl_mask
= 0, last_end
= 0;
5659 unsigned long start
, end
, mask
;
5663 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
5664 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
5671 * Start with a mask granular enough to pin-point to the
5672 * start pfn and tick off bits one-by-one until it becomes
5673 * too coarse to separate the current node from the last.
5675 mask
= ~((1 << __ffs(start
)) - 1);
5676 while (mask
&& last_end
<= (start
& (mask
<< 1)))
5679 /* accumulate all internode masks */
5683 /* convert mask to number of pages */
5684 return ~accl_mask
+ 1;
5687 /* Find the lowest pfn for a node */
5688 static unsigned long __init
find_min_pfn_for_node(int nid
)
5690 unsigned long min_pfn
= ULONG_MAX
;
5691 unsigned long start_pfn
;
5694 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
5695 min_pfn
= min(min_pfn
, start_pfn
);
5697 if (min_pfn
== ULONG_MAX
) {
5698 pr_warn("Could not find start_pfn for node %d\n", nid
);
5706 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5708 * It returns the minimum PFN based on information provided via
5709 * memblock_set_node().
5711 unsigned long __init
find_min_pfn_with_active_regions(void)
5713 return find_min_pfn_for_node(MAX_NUMNODES
);
5717 * early_calculate_totalpages()
5718 * Sum pages in active regions for movable zone.
5719 * Populate N_MEMORY for calculating usable_nodes.
5721 static unsigned long __init
early_calculate_totalpages(void)
5723 unsigned long totalpages
= 0;
5724 unsigned long start_pfn
, end_pfn
;
5727 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
5728 unsigned long pages
= end_pfn
- start_pfn
;
5730 totalpages
+= pages
;
5732 node_set_state(nid
, N_MEMORY
);
5738 * Find the PFN the Movable zone begins in each node. Kernel memory
5739 * is spread evenly between nodes as long as the nodes have enough
5740 * memory. When they don't, some nodes will have more kernelcore than
5743 static void __init
find_zone_movable_pfns_for_nodes(void)
5746 unsigned long usable_startpfn
;
5747 unsigned long kernelcore_node
, kernelcore_remaining
;
5748 /* save the state before borrow the nodemask */
5749 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
5750 unsigned long totalpages
= early_calculate_totalpages();
5751 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
5752 struct memblock_region
*r
;
5754 /* Need to find movable_zone earlier when movable_node is specified. */
5755 find_usable_zone_for_movable();
5758 * If movable_node is specified, ignore kernelcore and movablecore
5761 if (movable_node_is_enabled()) {
5762 for_each_memblock(memory
, r
) {
5763 if (!memblock_is_hotpluggable(r
))
5768 usable_startpfn
= PFN_DOWN(r
->base
);
5769 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
5770 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
5778 * If kernelcore=mirror is specified, ignore movablecore option
5780 if (mirrored_kernelcore
) {
5781 bool mem_below_4gb_not_mirrored
= false;
5783 for_each_memblock(memory
, r
) {
5784 if (memblock_is_mirror(r
))
5789 usable_startpfn
= memblock_region_memory_base_pfn(r
);
5791 if (usable_startpfn
< 0x100000) {
5792 mem_below_4gb_not_mirrored
= true;
5796 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
5797 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
5801 if (mem_below_4gb_not_mirrored
)
5802 pr_warn("This configuration results in unmirrored kernel memory.");
5808 * If movablecore=nn[KMG] was specified, calculate what size of
5809 * kernelcore that corresponds so that memory usable for
5810 * any allocation type is evenly spread. If both kernelcore
5811 * and movablecore are specified, then the value of kernelcore
5812 * will be used for required_kernelcore if it's greater than
5813 * what movablecore would have allowed.
5815 if (required_movablecore
) {
5816 unsigned long corepages
;
5819 * Round-up so that ZONE_MOVABLE is at least as large as what
5820 * was requested by the user
5822 required_movablecore
=
5823 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
5824 required_movablecore
= min(totalpages
, required_movablecore
);
5825 corepages
= totalpages
- required_movablecore
;
5827 required_kernelcore
= max(required_kernelcore
, corepages
);
5831 * If kernelcore was not specified or kernelcore size is larger
5832 * than totalpages, there is no ZONE_MOVABLE.
5834 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
5837 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5838 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
5841 /* Spread kernelcore memory as evenly as possible throughout nodes */
5842 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5843 for_each_node_state(nid
, N_MEMORY
) {
5844 unsigned long start_pfn
, end_pfn
;
5847 * Recalculate kernelcore_node if the division per node
5848 * now exceeds what is necessary to satisfy the requested
5849 * amount of memory for the kernel
5851 if (required_kernelcore
< kernelcore_node
)
5852 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5855 * As the map is walked, we track how much memory is usable
5856 * by the kernel using kernelcore_remaining. When it is
5857 * 0, the rest of the node is usable by ZONE_MOVABLE
5859 kernelcore_remaining
= kernelcore_node
;
5861 /* Go through each range of PFNs within this node */
5862 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5863 unsigned long size_pages
;
5865 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
5866 if (start_pfn
>= end_pfn
)
5869 /* Account for what is only usable for kernelcore */
5870 if (start_pfn
< usable_startpfn
) {
5871 unsigned long kernel_pages
;
5872 kernel_pages
= min(end_pfn
, usable_startpfn
)
5875 kernelcore_remaining
-= min(kernel_pages
,
5876 kernelcore_remaining
);
5877 required_kernelcore
-= min(kernel_pages
,
5878 required_kernelcore
);
5880 /* Continue if range is now fully accounted */
5881 if (end_pfn
<= usable_startpfn
) {
5884 * Push zone_movable_pfn to the end so
5885 * that if we have to rebalance
5886 * kernelcore across nodes, we will
5887 * not double account here
5889 zone_movable_pfn
[nid
] = end_pfn
;
5892 start_pfn
= usable_startpfn
;
5896 * The usable PFN range for ZONE_MOVABLE is from
5897 * start_pfn->end_pfn. Calculate size_pages as the
5898 * number of pages used as kernelcore
5900 size_pages
= end_pfn
- start_pfn
;
5901 if (size_pages
> kernelcore_remaining
)
5902 size_pages
= kernelcore_remaining
;
5903 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
5906 * Some kernelcore has been met, update counts and
5907 * break if the kernelcore for this node has been
5910 required_kernelcore
-= min(required_kernelcore
,
5912 kernelcore_remaining
-= size_pages
;
5913 if (!kernelcore_remaining
)
5919 * If there is still required_kernelcore, we do another pass with one
5920 * less node in the count. This will push zone_movable_pfn[nid] further
5921 * along on the nodes that still have memory until kernelcore is
5925 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
5929 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5930 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
5931 zone_movable_pfn
[nid
] =
5932 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
5935 /* restore the node_state */
5936 node_states
[N_MEMORY
] = saved_node_state
;
5939 /* Any regular or high memory on that node ? */
5940 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
5942 enum zone_type zone_type
;
5944 if (N_MEMORY
== N_NORMAL_MEMORY
)
5947 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
5948 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
5949 if (populated_zone(zone
)) {
5950 node_set_state(nid
, N_HIGH_MEMORY
);
5951 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
5952 zone_type
<= ZONE_NORMAL
)
5953 node_set_state(nid
, N_NORMAL_MEMORY
);
5960 * free_area_init_nodes - Initialise all pg_data_t and zone data
5961 * @max_zone_pfn: an array of max PFNs for each zone
5963 * This will call free_area_init_node() for each active node in the system.
5964 * Using the page ranges provided by memblock_set_node(), the size of each
5965 * zone in each node and their holes is calculated. If the maximum PFN
5966 * between two adjacent zones match, it is assumed that the zone is empty.
5967 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5968 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5969 * starts where the previous one ended. For example, ZONE_DMA32 starts
5970 * at arch_max_dma_pfn.
5972 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
5974 unsigned long start_pfn
, end_pfn
;
5977 /* Record where the zone boundaries are */
5978 memset(arch_zone_lowest_possible_pfn
, 0,
5979 sizeof(arch_zone_lowest_possible_pfn
));
5980 memset(arch_zone_highest_possible_pfn
, 0,
5981 sizeof(arch_zone_highest_possible_pfn
));
5982 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
5983 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
5984 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
5985 if (i
== ZONE_MOVABLE
)
5987 arch_zone_lowest_possible_pfn
[i
] =
5988 arch_zone_highest_possible_pfn
[i
-1];
5989 arch_zone_highest_possible_pfn
[i
] =
5990 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
5992 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
5993 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
5995 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
5996 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
5997 find_zone_movable_pfns_for_nodes();
5999 /* Print out the zone ranges */
6000 pr_info("Zone ranges:\n");
6001 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6002 if (i
== ZONE_MOVABLE
)
6004 pr_info(" %-8s ", zone_names
[i
]);
6005 if (arch_zone_lowest_possible_pfn
[i
] ==
6006 arch_zone_highest_possible_pfn
[i
])
6009 pr_cont("[mem %#018Lx-%#018Lx]\n",
6010 (u64
)arch_zone_lowest_possible_pfn
[i
]
6012 ((u64
)arch_zone_highest_possible_pfn
[i
]
6013 << PAGE_SHIFT
) - 1);
6016 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6017 pr_info("Movable zone start for each node\n");
6018 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
6019 if (zone_movable_pfn
[i
])
6020 pr_info(" Node %d: %#018Lx\n", i
,
6021 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
6024 /* Print out the early node map */
6025 pr_info("Early memory node ranges\n");
6026 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
6027 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
6028 (u64
)start_pfn
<< PAGE_SHIFT
,
6029 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
6031 /* Initialise every node */
6032 mminit_verify_pageflags_layout();
6033 setup_nr_node_ids();
6034 for_each_online_node(nid
) {
6035 pg_data_t
*pgdat
= NODE_DATA(nid
);
6036 free_area_init_node(nid
, NULL
,
6037 find_min_pfn_for_node(nid
), NULL
);
6039 /* Any memory on that node */
6040 if (pgdat
->node_present_pages
)
6041 node_set_state(nid
, N_MEMORY
);
6042 check_for_memory(pgdat
, nid
);
6046 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
6048 unsigned long long coremem
;
6052 coremem
= memparse(p
, &p
);
6053 *core
= coremem
>> PAGE_SHIFT
;
6055 /* Paranoid check that UL is enough for the coremem value */
6056 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
6062 * kernelcore=size sets the amount of memory for use for allocations that
6063 * cannot be reclaimed or migrated.
6065 static int __init
cmdline_parse_kernelcore(char *p
)
6067 /* parse kernelcore=mirror */
6068 if (parse_option_str(p
, "mirror")) {
6069 mirrored_kernelcore
= true;
6073 return cmdline_parse_core(p
, &required_kernelcore
);
6077 * movablecore=size sets the amount of memory for use for allocations that
6078 * can be reclaimed or migrated.
6080 static int __init
cmdline_parse_movablecore(char *p
)
6082 return cmdline_parse_core(p
, &required_movablecore
);
6085 early_param("kernelcore", cmdline_parse_kernelcore
);
6086 early_param("movablecore", cmdline_parse_movablecore
);
6088 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6090 void adjust_managed_page_count(struct page
*page
, long count
)
6092 spin_lock(&managed_page_count_lock
);
6093 page_zone(page
)->managed_pages
+= count
;
6094 totalram_pages
+= count
;
6095 #ifdef CONFIG_HIGHMEM
6096 if (PageHighMem(page
))
6097 totalhigh_pages
+= count
;
6099 spin_unlock(&managed_page_count_lock
);
6101 EXPORT_SYMBOL(adjust_managed_page_count
);
6103 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
6106 unsigned long pages
= 0;
6108 start
= (void *)PAGE_ALIGN((unsigned long)start
);
6109 end
= (void *)((unsigned long)end
& PAGE_MASK
);
6110 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
6111 if ((unsigned int)poison
<= 0xFF)
6112 memset(pos
, poison
, PAGE_SIZE
);
6113 free_reserved_page(virt_to_page(pos
));
6117 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
6118 s
, pages
<< (PAGE_SHIFT
- 10), start
, end
);
6122 EXPORT_SYMBOL(free_reserved_area
);
6124 #ifdef CONFIG_HIGHMEM
6125 void free_highmem_page(struct page
*page
)
6127 __free_reserved_page(page
);
6129 page_zone(page
)->managed_pages
++;
6135 void __init
mem_init_print_info(const char *str
)
6137 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
6138 unsigned long init_code_size
, init_data_size
;
6140 physpages
= get_num_physpages();
6141 codesize
= _etext
- _stext
;
6142 datasize
= _edata
- _sdata
;
6143 rosize
= __end_rodata
- __start_rodata
;
6144 bss_size
= __bss_stop
- __bss_start
;
6145 init_data_size
= __init_end
- __init_begin
;
6146 init_code_size
= _einittext
- _sinittext
;
6149 * Detect special cases and adjust section sizes accordingly:
6150 * 1) .init.* may be embedded into .data sections
6151 * 2) .init.text.* may be out of [__init_begin, __init_end],
6152 * please refer to arch/tile/kernel/vmlinux.lds.S.
6153 * 3) .rodata.* may be embedded into .text or .data sections.
6155 #define adj_init_size(start, end, size, pos, adj) \
6157 if (start <= pos && pos < end && size > adj) \
6161 adj_init_size(__init_begin
, __init_end
, init_data_size
,
6162 _sinittext
, init_code_size
);
6163 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
6164 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
6165 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
6166 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
6168 #undef adj_init_size
6170 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6171 #ifdef CONFIG_HIGHMEM
6175 nr_free_pages() << (PAGE_SHIFT
- 10),
6176 physpages
<< (PAGE_SHIFT
- 10),
6177 codesize
>> 10, datasize
>> 10, rosize
>> 10,
6178 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
6179 (physpages
- totalram_pages
- totalcma_pages
) << (PAGE_SHIFT
- 10),
6180 totalcma_pages
<< (PAGE_SHIFT
- 10),
6181 #ifdef CONFIG_HIGHMEM
6182 totalhigh_pages
<< (PAGE_SHIFT
- 10),
6184 str
? ", " : "", str
? str
: "");
6188 * set_dma_reserve - set the specified number of pages reserved in the first zone
6189 * @new_dma_reserve: The number of pages to mark reserved
6191 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6192 * In the DMA zone, a significant percentage may be consumed by kernel image
6193 * and other unfreeable allocations which can skew the watermarks badly. This
6194 * function may optionally be used to account for unfreeable pages in the
6195 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6196 * smaller per-cpu batchsize.
6198 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
6200 dma_reserve
= new_dma_reserve
;
6203 void __init
free_area_init(unsigned long *zones_size
)
6205 free_area_init_node(0, zones_size
,
6206 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
6209 static int page_alloc_cpu_notify(struct notifier_block
*self
,
6210 unsigned long action
, void *hcpu
)
6212 int cpu
= (unsigned long)hcpu
;
6214 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
6215 lru_add_drain_cpu(cpu
);
6219 * Spill the event counters of the dead processor
6220 * into the current processors event counters.
6221 * This artificially elevates the count of the current
6224 vm_events_fold_cpu(cpu
);
6227 * Zero the differential counters of the dead processor
6228 * so that the vm statistics are consistent.
6230 * This is only okay since the processor is dead and cannot
6231 * race with what we are doing.
6233 cpu_vm_stats_fold(cpu
);
6238 void __init
page_alloc_init(void)
6240 hotcpu_notifier(page_alloc_cpu_notify
, 0);
6244 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6245 * or min_free_kbytes changes.
6247 static void calculate_totalreserve_pages(void)
6249 struct pglist_data
*pgdat
;
6250 unsigned long reserve_pages
= 0;
6251 enum zone_type i
, j
;
6253 for_each_online_pgdat(pgdat
) {
6254 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6255 struct zone
*zone
= pgdat
->node_zones
+ i
;
6258 /* Find valid and maximum lowmem_reserve in the zone */
6259 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
6260 if (zone
->lowmem_reserve
[j
] > max
)
6261 max
= zone
->lowmem_reserve
[j
];
6264 /* we treat the high watermark as reserved pages. */
6265 max
+= high_wmark_pages(zone
);
6267 if (max
> zone
->managed_pages
)
6268 max
= zone
->managed_pages
;
6270 zone
->totalreserve_pages
= max
;
6272 reserve_pages
+= max
;
6275 totalreserve_pages
= reserve_pages
;
6279 * setup_per_zone_lowmem_reserve - called whenever
6280 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6281 * has a correct pages reserved value, so an adequate number of
6282 * pages are left in the zone after a successful __alloc_pages().
6284 static void setup_per_zone_lowmem_reserve(void)
6286 struct pglist_data
*pgdat
;
6287 enum zone_type j
, idx
;
6289 for_each_online_pgdat(pgdat
) {
6290 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6291 struct zone
*zone
= pgdat
->node_zones
+ j
;
6292 unsigned long managed_pages
= zone
->managed_pages
;
6294 zone
->lowmem_reserve
[j
] = 0;
6298 struct zone
*lower_zone
;
6302 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
6303 sysctl_lowmem_reserve_ratio
[idx
] = 1;
6305 lower_zone
= pgdat
->node_zones
+ idx
;
6306 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
6307 sysctl_lowmem_reserve_ratio
[idx
];
6308 managed_pages
+= lower_zone
->managed_pages
;
6313 /* update totalreserve_pages */
6314 calculate_totalreserve_pages();
6317 static void __setup_per_zone_wmarks(void)
6319 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
6320 unsigned long lowmem_pages
= 0;
6322 unsigned long flags
;
6324 /* Calculate total number of !ZONE_HIGHMEM pages */
6325 for_each_zone(zone
) {
6326 if (!is_highmem(zone
))
6327 lowmem_pages
+= zone
->managed_pages
;
6330 for_each_zone(zone
) {
6333 spin_lock_irqsave(&zone
->lock
, flags
);
6334 tmp
= (u64
)pages_min
* zone
->managed_pages
;
6335 do_div(tmp
, lowmem_pages
);
6336 if (is_highmem(zone
)) {
6338 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6339 * need highmem pages, so cap pages_min to a small
6342 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6343 * deltas control asynch page reclaim, and so should
6344 * not be capped for highmem.
6346 unsigned long min_pages
;
6348 min_pages
= zone
->managed_pages
/ 1024;
6349 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
6350 zone
->watermark
[WMARK_MIN
] = min_pages
;
6353 * If it's a lowmem zone, reserve a number of pages
6354 * proportionate to the zone's size.
6356 zone
->watermark
[WMARK_MIN
] = tmp
;
6360 * Set the kswapd watermarks distance according to the
6361 * scale factor in proportion to available memory, but
6362 * ensure a minimum size on small systems.
6364 tmp
= max_t(u64
, tmp
>> 2,
6365 mult_frac(zone
->managed_pages
,
6366 watermark_scale_factor
, 10000));
6368 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + tmp
;
6369 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + tmp
* 2;
6371 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
6372 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
6373 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
6375 spin_unlock_irqrestore(&zone
->lock
, flags
);
6378 /* update totalreserve_pages */
6379 calculate_totalreserve_pages();
6383 * setup_per_zone_wmarks - called when min_free_kbytes changes
6384 * or when memory is hot-{added|removed}
6386 * Ensures that the watermark[min,low,high] values for each zone are set
6387 * correctly with respect to min_free_kbytes.
6389 void setup_per_zone_wmarks(void)
6391 mutex_lock(&zonelists_mutex
);
6392 __setup_per_zone_wmarks();
6393 mutex_unlock(&zonelists_mutex
);
6397 * The inactive anon list should be small enough that the VM never has to
6398 * do too much work, but large enough that each inactive page has a chance
6399 * to be referenced again before it is swapped out.
6401 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
6402 * INACTIVE_ANON pages on this zone's LRU, maintained by the
6403 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
6404 * the anonymous pages are kept on the inactive list.
6407 * memory ratio inactive anon
6408 * -------------------------------------
6417 static void __meminit
calculate_zone_inactive_ratio(struct zone
*zone
)
6419 unsigned int gb
, ratio
;
6421 /* Zone size in gigabytes */
6422 gb
= zone
->managed_pages
>> (30 - PAGE_SHIFT
);
6424 ratio
= int_sqrt(10 * gb
);
6428 zone
->inactive_ratio
= ratio
;
6431 static void __meminit
setup_per_zone_inactive_ratio(void)
6436 calculate_zone_inactive_ratio(zone
);
6440 * Initialise min_free_kbytes.
6442 * For small machines we want it small (128k min). For large machines
6443 * we want it large (64MB max). But it is not linear, because network
6444 * bandwidth does not increase linearly with machine size. We use
6446 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6447 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6463 int __meminit
init_per_zone_wmark_min(void)
6465 unsigned long lowmem_kbytes
;
6466 int new_min_free_kbytes
;
6468 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
6469 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
6471 if (new_min_free_kbytes
> user_min_free_kbytes
) {
6472 min_free_kbytes
= new_min_free_kbytes
;
6473 if (min_free_kbytes
< 128)
6474 min_free_kbytes
= 128;
6475 if (min_free_kbytes
> 65536)
6476 min_free_kbytes
= 65536;
6478 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6479 new_min_free_kbytes
, user_min_free_kbytes
);
6481 setup_per_zone_wmarks();
6482 refresh_zone_stat_thresholds();
6483 setup_per_zone_lowmem_reserve();
6484 setup_per_zone_inactive_ratio();
6487 core_initcall(init_per_zone_wmark_min
)
6490 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6491 * that we can call two helper functions whenever min_free_kbytes
6494 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
6495 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6499 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6504 user_min_free_kbytes
= min_free_kbytes
;
6505 setup_per_zone_wmarks();
6510 int watermark_scale_factor_sysctl_handler(struct ctl_table
*table
, int write
,
6511 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6515 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6520 setup_per_zone_wmarks();
6526 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6527 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6532 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6537 zone
->min_unmapped_pages
= (zone
->managed_pages
*
6538 sysctl_min_unmapped_ratio
) / 100;
6542 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6543 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6548 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6553 zone
->min_slab_pages
= (zone
->managed_pages
*
6554 sysctl_min_slab_ratio
) / 100;
6560 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6561 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6562 * whenever sysctl_lowmem_reserve_ratio changes.
6564 * The reserve ratio obviously has absolutely no relation with the
6565 * minimum watermarks. The lowmem reserve ratio can only make sense
6566 * if in function of the boot time zone sizes.
6568 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6569 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6571 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6572 setup_per_zone_lowmem_reserve();
6577 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6578 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6579 * pagelist can have before it gets flushed back to buddy allocator.
6581 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
6582 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6585 int old_percpu_pagelist_fraction
;
6588 mutex_lock(&pcp_batch_high_lock
);
6589 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
6591 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6592 if (!write
|| ret
< 0)
6595 /* Sanity checking to avoid pcp imbalance */
6596 if (percpu_pagelist_fraction
&&
6597 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
6598 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
6604 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
6607 for_each_populated_zone(zone
) {
6610 for_each_possible_cpu(cpu
)
6611 pageset_set_high_and_batch(zone
,
6612 per_cpu_ptr(zone
->pageset
, cpu
));
6615 mutex_unlock(&pcp_batch_high_lock
);
6620 int hashdist
= HASHDIST_DEFAULT
;
6622 static int __init
set_hashdist(char *str
)
6626 hashdist
= simple_strtoul(str
, &str
, 0);
6629 __setup("hashdist=", set_hashdist
);
6633 * allocate a large system hash table from bootmem
6634 * - it is assumed that the hash table must contain an exact power-of-2
6635 * quantity of entries
6636 * - limit is the number of hash buckets, not the total allocation size
6638 void *__init
alloc_large_system_hash(const char *tablename
,
6639 unsigned long bucketsize
,
6640 unsigned long numentries
,
6643 unsigned int *_hash_shift
,
6644 unsigned int *_hash_mask
,
6645 unsigned long low_limit
,
6646 unsigned long high_limit
)
6648 unsigned long long max
= high_limit
;
6649 unsigned long log2qty
, size
;
6652 /* allow the kernel cmdline to have a say */
6654 /* round applicable memory size up to nearest megabyte */
6655 numentries
= nr_kernel_pages
;
6657 /* It isn't necessary when PAGE_SIZE >= 1MB */
6658 if (PAGE_SHIFT
< 20)
6659 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
6661 /* limit to 1 bucket per 2^scale bytes of low memory */
6662 if (scale
> PAGE_SHIFT
)
6663 numentries
>>= (scale
- PAGE_SHIFT
);
6665 numentries
<<= (PAGE_SHIFT
- scale
);
6667 /* Make sure we've got at least a 0-order allocation.. */
6668 if (unlikely(flags
& HASH_SMALL
)) {
6669 /* Makes no sense without HASH_EARLY */
6670 WARN_ON(!(flags
& HASH_EARLY
));
6671 if (!(numentries
>> *_hash_shift
)) {
6672 numentries
= 1UL << *_hash_shift
;
6673 BUG_ON(!numentries
);
6675 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
6676 numentries
= PAGE_SIZE
/ bucketsize
;
6678 numentries
= roundup_pow_of_two(numentries
);
6680 /* limit allocation size to 1/16 total memory by default */
6682 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
6683 do_div(max
, bucketsize
);
6685 max
= min(max
, 0x80000000ULL
);
6687 if (numentries
< low_limit
)
6688 numentries
= low_limit
;
6689 if (numentries
> max
)
6692 log2qty
= ilog2(numentries
);
6695 size
= bucketsize
<< log2qty
;
6696 if (flags
& HASH_EARLY
)
6697 table
= memblock_virt_alloc_nopanic(size
, 0);
6699 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
6702 * If bucketsize is not a power-of-two, we may free
6703 * some pages at the end of hash table which
6704 * alloc_pages_exact() automatically does
6706 if (get_order(size
) < MAX_ORDER
) {
6707 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
6708 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
6711 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
6714 panic("Failed to allocate %s hash table\n", tablename
);
6716 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
6717 tablename
, 1UL << log2qty
, ilog2(size
) - PAGE_SHIFT
, size
);
6720 *_hash_shift
= log2qty
;
6722 *_hash_mask
= (1 << log2qty
) - 1;
6727 /* Return a pointer to the bitmap storing bits affecting a block of pages */
6728 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
6731 #ifdef CONFIG_SPARSEMEM
6732 return __pfn_to_section(pfn
)->pageblock_flags
;
6734 return zone
->pageblock_flags
;
6735 #endif /* CONFIG_SPARSEMEM */
6738 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
6740 #ifdef CONFIG_SPARSEMEM
6741 pfn
&= (PAGES_PER_SECTION
-1);
6742 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6744 pfn
= pfn
- round_down(zone
->zone_start_pfn
, pageblock_nr_pages
);
6745 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6746 #endif /* CONFIG_SPARSEMEM */
6750 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
6751 * @page: The page within the block of interest
6752 * @pfn: The target page frame number
6753 * @end_bitidx: The last bit of interest to retrieve
6754 * @mask: mask of bits that the caller is interested in
6756 * Return: pageblock_bits flags
6758 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
6759 unsigned long end_bitidx
,
6763 unsigned long *bitmap
;
6764 unsigned long bitidx
, word_bitidx
;
6767 zone
= page_zone(page
);
6768 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6769 bitidx
= pfn_to_bitidx(zone
, pfn
);
6770 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6771 bitidx
&= (BITS_PER_LONG
-1);
6773 word
= bitmap
[word_bitidx
];
6774 bitidx
+= end_bitidx
;
6775 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
6779 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
6780 * @page: The page within the block of interest
6781 * @flags: The flags to set
6782 * @pfn: The target page frame number
6783 * @end_bitidx: The last bit of interest
6784 * @mask: mask of bits that the caller is interested in
6786 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
6788 unsigned long end_bitidx
,
6792 unsigned long *bitmap
;
6793 unsigned long bitidx
, word_bitidx
;
6794 unsigned long old_word
, word
;
6796 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
6798 zone
= page_zone(page
);
6799 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6800 bitidx
= pfn_to_bitidx(zone
, pfn
);
6801 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6802 bitidx
&= (BITS_PER_LONG
-1);
6804 VM_BUG_ON_PAGE(!zone_spans_pfn(zone
, pfn
), page
);
6806 bitidx
+= end_bitidx
;
6807 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
6808 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
6810 word
= READ_ONCE(bitmap
[word_bitidx
]);
6812 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
6813 if (word
== old_word
)
6820 * This function checks whether pageblock includes unmovable pages or not.
6821 * If @count is not zero, it is okay to include less @count unmovable pages
6823 * PageLRU check without isolation or lru_lock could race so that
6824 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6825 * expect this function should be exact.
6827 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
6828 bool skip_hwpoisoned_pages
)
6830 unsigned long pfn
, iter
, found
;
6834 * For avoiding noise data, lru_add_drain_all() should be called
6835 * If ZONE_MOVABLE, the zone never contains unmovable pages
6837 if (zone_idx(zone
) == ZONE_MOVABLE
)
6839 mt
= get_pageblock_migratetype(page
);
6840 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
6843 pfn
= page_to_pfn(page
);
6844 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
6845 unsigned long check
= pfn
+ iter
;
6847 if (!pfn_valid_within(check
))
6850 page
= pfn_to_page(check
);
6853 * Hugepages are not in LRU lists, but they're movable.
6854 * We need not scan over tail pages bacause we don't
6855 * handle each tail page individually in migration.
6857 if (PageHuge(page
)) {
6858 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
6863 * We can't use page_count without pin a page
6864 * because another CPU can free compound page.
6865 * This check already skips compound tails of THP
6866 * because their page->_refcount is zero at all time.
6868 if (!page_ref_count(page
)) {
6869 if (PageBuddy(page
))
6870 iter
+= (1 << page_order(page
)) - 1;
6875 * The HWPoisoned page may be not in buddy system, and
6876 * page_count() is not 0.
6878 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
6884 * If there are RECLAIMABLE pages, we need to check
6885 * it. But now, memory offline itself doesn't call
6886 * shrink_node_slabs() and it still to be fixed.
6889 * If the page is not RAM, page_count()should be 0.
6890 * we don't need more check. This is an _used_ not-movable page.
6892 * The problematic thing here is PG_reserved pages. PG_reserved
6893 * is set to both of a memory hole page and a _used_ kernel
6902 bool is_pageblock_removable_nolock(struct page
*page
)
6908 * We have to be careful here because we are iterating over memory
6909 * sections which are not zone aware so we might end up outside of
6910 * the zone but still within the section.
6911 * We have to take care about the node as well. If the node is offline
6912 * its NODE_DATA will be NULL - see page_zone.
6914 if (!node_online(page_to_nid(page
)))
6917 zone
= page_zone(page
);
6918 pfn
= page_to_pfn(page
);
6919 if (!zone_spans_pfn(zone
, pfn
))
6922 return !has_unmovable_pages(zone
, page
, 0, true);
6925 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
6927 static unsigned long pfn_max_align_down(unsigned long pfn
)
6929 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6930 pageblock_nr_pages
) - 1);
6933 static unsigned long pfn_max_align_up(unsigned long pfn
)
6935 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6936 pageblock_nr_pages
));
6939 /* [start, end) must belong to a single zone. */
6940 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
6941 unsigned long start
, unsigned long end
)
6943 /* This function is based on compact_zone() from compaction.c. */
6944 unsigned long nr_reclaimed
;
6945 unsigned long pfn
= start
;
6946 unsigned int tries
= 0;
6951 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
6952 if (fatal_signal_pending(current
)) {
6957 if (list_empty(&cc
->migratepages
)) {
6958 cc
->nr_migratepages
= 0;
6959 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
6965 } else if (++tries
== 5) {
6966 ret
= ret
< 0 ? ret
: -EBUSY
;
6970 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
6972 cc
->nr_migratepages
-= nr_reclaimed
;
6974 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
6975 NULL
, 0, cc
->mode
, MR_CMA
);
6978 putback_movable_pages(&cc
->migratepages
);
6985 * alloc_contig_range() -- tries to allocate given range of pages
6986 * @start: start PFN to allocate
6987 * @end: one-past-the-last PFN to allocate
6988 * @migratetype: migratetype of the underlaying pageblocks (either
6989 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
6990 * in range must have the same migratetype and it must
6991 * be either of the two.
6993 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
6994 * aligned, however it's the caller's responsibility to guarantee that
6995 * we are the only thread that changes migrate type of pageblocks the
6998 * The PFN range must belong to a single zone.
7000 * Returns zero on success or negative error code. On success all
7001 * pages which PFN is in [start, end) are allocated for the caller and
7002 * need to be freed with free_contig_range().
7004 int alloc_contig_range(unsigned long start
, unsigned long end
,
7005 unsigned migratetype
)
7007 unsigned long outer_start
, outer_end
;
7011 struct compact_control cc
= {
7012 .nr_migratepages
= 0,
7014 .zone
= page_zone(pfn_to_page(start
)),
7015 .mode
= MIGRATE_SYNC
,
7016 .ignore_skip_hint
= true,
7018 INIT_LIST_HEAD(&cc
.migratepages
);
7021 * What we do here is we mark all pageblocks in range as
7022 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7023 * have different sizes, and due to the way page allocator
7024 * work, we align the range to biggest of the two pages so
7025 * that page allocator won't try to merge buddies from
7026 * different pageblocks and change MIGRATE_ISOLATE to some
7027 * other migration type.
7029 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7030 * migrate the pages from an unaligned range (ie. pages that
7031 * we are interested in). This will put all the pages in
7032 * range back to page allocator as MIGRATE_ISOLATE.
7034 * When this is done, we take the pages in range from page
7035 * allocator removing them from the buddy system. This way
7036 * page allocator will never consider using them.
7038 * This lets us mark the pageblocks back as
7039 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7040 * aligned range but not in the unaligned, original range are
7041 * put back to page allocator so that buddy can use them.
7044 ret
= start_isolate_page_range(pfn_max_align_down(start
),
7045 pfn_max_align_up(end
), migratetype
,
7051 * In case of -EBUSY, we'd like to know which page causes problem.
7052 * So, just fall through. We will check it in test_pages_isolated().
7054 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
7055 if (ret
&& ret
!= -EBUSY
)
7059 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7060 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7061 * more, all pages in [start, end) are free in page allocator.
7062 * What we are going to do is to allocate all pages from
7063 * [start, end) (that is remove them from page allocator).
7065 * The only problem is that pages at the beginning and at the
7066 * end of interesting range may be not aligned with pages that
7067 * page allocator holds, ie. they can be part of higher order
7068 * pages. Because of this, we reserve the bigger range and
7069 * once this is done free the pages we are not interested in.
7071 * We don't have to hold zone->lock here because the pages are
7072 * isolated thus they won't get removed from buddy.
7075 lru_add_drain_all();
7076 drain_all_pages(cc
.zone
);
7079 outer_start
= start
;
7080 while (!PageBuddy(pfn_to_page(outer_start
))) {
7081 if (++order
>= MAX_ORDER
) {
7082 outer_start
= start
;
7085 outer_start
&= ~0UL << order
;
7088 if (outer_start
!= start
) {
7089 order
= page_order(pfn_to_page(outer_start
));
7092 * outer_start page could be small order buddy page and
7093 * it doesn't include start page. Adjust outer_start
7094 * in this case to report failed page properly
7095 * on tracepoint in test_pages_isolated()
7097 if (outer_start
+ (1UL << order
) <= start
)
7098 outer_start
= start
;
7101 /* Make sure the range is really isolated. */
7102 if (test_pages_isolated(outer_start
, end
, false)) {
7103 pr_info("%s: [%lx, %lx) PFNs busy\n",
7104 __func__
, outer_start
, end
);
7109 /* Grab isolated pages from freelists. */
7110 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
7116 /* Free head and tail (if any) */
7117 if (start
!= outer_start
)
7118 free_contig_range(outer_start
, start
- outer_start
);
7119 if (end
!= outer_end
)
7120 free_contig_range(end
, outer_end
- end
);
7123 undo_isolate_page_range(pfn_max_align_down(start
),
7124 pfn_max_align_up(end
), migratetype
);
7128 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
7130 unsigned int count
= 0;
7132 for (; nr_pages
--; pfn
++) {
7133 struct page
*page
= pfn_to_page(pfn
);
7135 count
+= page_count(page
) != 1;
7138 WARN(count
!= 0, "%d pages are still in use!\n", count
);
7142 #ifdef CONFIG_MEMORY_HOTPLUG
7144 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7145 * page high values need to be recalulated.
7147 void __meminit
zone_pcp_update(struct zone
*zone
)
7150 mutex_lock(&pcp_batch_high_lock
);
7151 for_each_possible_cpu(cpu
)
7152 pageset_set_high_and_batch(zone
,
7153 per_cpu_ptr(zone
->pageset
, cpu
));
7154 mutex_unlock(&pcp_batch_high_lock
);
7158 void zone_pcp_reset(struct zone
*zone
)
7160 unsigned long flags
;
7162 struct per_cpu_pageset
*pset
;
7164 /* avoid races with drain_pages() */
7165 local_irq_save(flags
);
7166 if (zone
->pageset
!= &boot_pageset
) {
7167 for_each_online_cpu(cpu
) {
7168 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
7169 drain_zonestat(zone
, pset
);
7171 free_percpu(zone
->pageset
);
7172 zone
->pageset
= &boot_pageset
;
7174 local_irq_restore(flags
);
7177 #ifdef CONFIG_MEMORY_HOTREMOVE
7179 * All pages in the range must be in a single zone and isolated
7180 * before calling this.
7183 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
7187 unsigned int order
, i
;
7189 unsigned long flags
;
7190 /* find the first valid pfn */
7191 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
7196 zone
= page_zone(pfn_to_page(pfn
));
7197 spin_lock_irqsave(&zone
->lock
, flags
);
7199 while (pfn
< end_pfn
) {
7200 if (!pfn_valid(pfn
)) {
7204 page
= pfn_to_page(pfn
);
7206 * The HWPoisoned page may be not in buddy system, and
7207 * page_count() is not 0.
7209 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
7211 SetPageReserved(page
);
7215 BUG_ON(page_count(page
));
7216 BUG_ON(!PageBuddy(page
));
7217 order
= page_order(page
);
7218 #ifdef CONFIG_DEBUG_VM
7219 pr_info("remove from free list %lx %d %lx\n",
7220 pfn
, 1 << order
, end_pfn
);
7222 list_del(&page
->lru
);
7223 rmv_page_order(page
);
7224 zone
->free_area
[order
].nr_free
--;
7225 for (i
= 0; i
< (1 << order
); i
++)
7226 SetPageReserved((page
+i
));
7227 pfn
+= (1 << order
);
7229 spin_unlock_irqrestore(&zone
->lock
, flags
);
7233 bool is_free_buddy_page(struct page
*page
)
7235 struct zone
*zone
= page_zone(page
);
7236 unsigned long pfn
= page_to_pfn(page
);
7237 unsigned long flags
;
7240 spin_lock_irqsave(&zone
->lock
, flags
);
7241 for (order
= 0; order
< MAX_ORDER
; order
++) {
7242 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
7244 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
7247 spin_unlock_irqrestore(&zone
->lock
, flags
);
7249 return order
< MAX_ORDER
;