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
);
2160 if (page_zone(page
) != zone
)
2163 if (!swsusp_page_is_forbidden(page
))
2164 swsusp_unset_page_free(page
);
2167 for_each_migratetype_order(order
, t
) {
2168 list_for_each_entry(page
,
2169 &zone
->free_area
[order
].free_list
[t
], lru
) {
2172 pfn
= page_to_pfn(page
);
2173 for (i
= 0; i
< (1UL << order
); i
++)
2174 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
2177 spin_unlock_irqrestore(&zone
->lock
, flags
);
2179 #endif /* CONFIG_PM */
2182 * Free a 0-order page
2183 * cold == true ? free a cold page : free a hot page
2185 void free_hot_cold_page(struct page
*page
, bool cold
)
2187 struct zone
*zone
= page_zone(page
);
2188 struct per_cpu_pages
*pcp
;
2189 unsigned long flags
;
2190 unsigned long pfn
= page_to_pfn(page
);
2193 if (!free_pages_prepare(page
, 0))
2196 migratetype
= get_pfnblock_migratetype(page
, pfn
);
2197 set_pcppage_migratetype(page
, migratetype
);
2198 local_irq_save(flags
);
2199 __count_vm_event(PGFREE
);
2202 * We only track unmovable, reclaimable and movable on pcp lists.
2203 * Free ISOLATE pages back to the allocator because they are being
2204 * offlined but treat RESERVE as movable pages so we can get those
2205 * areas back if necessary. Otherwise, we may have to free
2206 * excessively into the page allocator
2208 if (migratetype
>= MIGRATE_PCPTYPES
) {
2209 if (unlikely(is_migrate_isolate(migratetype
))) {
2210 free_one_page(zone
, page
, pfn
, 0, migratetype
);
2213 migratetype
= MIGRATE_MOVABLE
;
2216 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2218 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
2220 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
2222 if (pcp
->count
>= pcp
->high
) {
2223 unsigned long batch
= READ_ONCE(pcp
->batch
);
2224 free_pcppages_bulk(zone
, batch
, pcp
);
2225 pcp
->count
-= batch
;
2229 local_irq_restore(flags
);
2233 * Free a list of 0-order pages
2235 void free_hot_cold_page_list(struct list_head
*list
, bool cold
)
2237 struct page
*page
, *next
;
2239 list_for_each_entry_safe(page
, next
, list
, lru
) {
2240 trace_mm_page_free_batched(page
, cold
);
2241 free_hot_cold_page(page
, cold
);
2246 * split_page takes a non-compound higher-order page, and splits it into
2247 * n (1<<order) sub-pages: page[0..n]
2248 * Each sub-page must be freed individually.
2250 * Note: this is probably too low level an operation for use in drivers.
2251 * Please consult with lkml before using this in your driver.
2253 void split_page(struct page
*page
, unsigned int order
)
2258 VM_BUG_ON_PAGE(PageCompound(page
), page
);
2259 VM_BUG_ON_PAGE(!page_count(page
), page
);
2261 #ifdef CONFIG_KMEMCHECK
2263 * Split shadow pages too, because free(page[0]) would
2264 * otherwise free the whole shadow.
2266 if (kmemcheck_page_is_tracked(page
))
2267 split_page(virt_to_page(page
[0].shadow
), order
);
2270 gfp_mask
= get_page_owner_gfp(page
);
2271 set_page_owner(page
, 0, gfp_mask
);
2272 for (i
= 1; i
< (1 << order
); i
++) {
2273 set_page_refcounted(page
+ i
);
2274 set_page_owner(page
+ i
, 0, gfp_mask
);
2277 EXPORT_SYMBOL_GPL(split_page
);
2279 int __isolate_free_page(struct page
*page
, unsigned int order
)
2281 unsigned long watermark
;
2285 BUG_ON(!PageBuddy(page
));
2287 zone
= page_zone(page
);
2288 mt
= get_pageblock_migratetype(page
);
2290 if (!is_migrate_isolate(mt
)) {
2291 /* Obey watermarks as if the page was being allocated */
2292 watermark
= low_wmark_pages(zone
) + (1 << order
);
2293 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
2296 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
2299 /* Remove page from free list */
2300 list_del(&page
->lru
);
2301 zone
->free_area
[order
].nr_free
--;
2302 rmv_page_order(page
);
2304 set_page_owner(page
, order
, __GFP_MOVABLE
);
2306 /* Set the pageblock if the isolated page is at least a pageblock */
2307 if (order
>= pageblock_order
- 1) {
2308 struct page
*endpage
= page
+ (1 << order
) - 1;
2309 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
2310 int mt
= get_pageblock_migratetype(page
);
2311 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
))
2312 set_pageblock_migratetype(page
,
2318 return 1UL << order
;
2322 * Similar to split_page except the page is already free. As this is only
2323 * being used for migration, the migratetype of the block also changes.
2324 * As this is called with interrupts disabled, the caller is responsible
2325 * for calling arch_alloc_page() and kernel_map_page() after interrupts
2328 * Note: this is probably too low level an operation for use in drivers.
2329 * Please consult with lkml before using this in your driver.
2331 int split_free_page(struct page
*page
)
2336 order
= page_order(page
);
2338 nr_pages
= __isolate_free_page(page
, order
);
2342 /* Split into individual pages */
2343 set_page_refcounted(page
);
2344 split_page(page
, order
);
2349 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2352 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
2353 struct zone
*zone
, unsigned int order
,
2354 gfp_t gfp_flags
, int alloc_flags
, int migratetype
)
2356 unsigned long flags
;
2358 bool cold
= ((gfp_flags
& __GFP_COLD
) != 0);
2360 if (likely(order
== 0)) {
2361 struct per_cpu_pages
*pcp
;
2362 struct list_head
*list
;
2364 local_irq_save(flags
);
2365 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2366 list
= &pcp
->lists
[migratetype
];
2367 if (list_empty(list
)) {
2368 pcp
->count
+= rmqueue_bulk(zone
, 0,
2371 if (unlikely(list_empty(list
)))
2376 page
= list_last_entry(list
, struct page
, lru
);
2378 page
= list_first_entry(list
, struct page
, lru
);
2380 list_del(&page
->lru
);
2384 * We most definitely don't want callers attempting to
2385 * allocate greater than order-1 page units with __GFP_NOFAIL.
2387 WARN_ON_ONCE((gfp_flags
& __GFP_NOFAIL
) && (order
> 1));
2388 spin_lock_irqsave(&zone
->lock
, flags
);
2391 if (alloc_flags
& ALLOC_HARDER
) {
2392 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
2394 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2397 page
= __rmqueue(zone
, order
, migratetype
);
2398 spin_unlock(&zone
->lock
);
2401 __mod_zone_freepage_state(zone
, -(1 << order
),
2402 get_pcppage_migratetype(page
));
2405 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
, -(1 << order
));
2406 if (atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]) <= 0 &&
2407 !test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
))
2408 set_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2410 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
2411 zone_statistics(preferred_zone
, zone
, gfp_flags
);
2412 local_irq_restore(flags
);
2414 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
2418 local_irq_restore(flags
);
2422 #ifdef CONFIG_FAIL_PAGE_ALLOC
2425 struct fault_attr attr
;
2427 bool ignore_gfp_highmem
;
2428 bool ignore_gfp_reclaim
;
2430 } fail_page_alloc
= {
2431 .attr
= FAULT_ATTR_INITIALIZER
,
2432 .ignore_gfp_reclaim
= true,
2433 .ignore_gfp_highmem
= true,
2437 static int __init
setup_fail_page_alloc(char *str
)
2439 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
2441 __setup("fail_page_alloc=", setup_fail_page_alloc
);
2443 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2445 if (order
< fail_page_alloc
.min_order
)
2447 if (gfp_mask
& __GFP_NOFAIL
)
2449 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
2451 if (fail_page_alloc
.ignore_gfp_reclaim
&&
2452 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
2455 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
2458 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2460 static int __init
fail_page_alloc_debugfs(void)
2462 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
2465 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
2466 &fail_page_alloc
.attr
);
2468 return PTR_ERR(dir
);
2470 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
2471 &fail_page_alloc
.ignore_gfp_reclaim
))
2473 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
2474 &fail_page_alloc
.ignore_gfp_highmem
))
2476 if (!debugfs_create_u32("min-order", mode
, dir
,
2477 &fail_page_alloc
.min_order
))
2482 debugfs_remove_recursive(dir
);
2487 late_initcall(fail_page_alloc_debugfs
);
2489 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2491 #else /* CONFIG_FAIL_PAGE_ALLOC */
2493 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2498 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2501 * Return true if free base pages are above 'mark'. For high-order checks it
2502 * will return true of the order-0 watermark is reached and there is at least
2503 * one free page of a suitable size. Checking now avoids taking the zone lock
2504 * to check in the allocation paths if no pages are free.
2506 static bool __zone_watermark_ok(struct zone
*z
, unsigned int order
,
2507 unsigned long mark
, int classzone_idx
, int alloc_flags
,
2512 const int alloc_harder
= (alloc_flags
& ALLOC_HARDER
);
2514 /* free_pages may go negative - that's OK */
2515 free_pages
-= (1 << order
) - 1;
2517 if (alloc_flags
& ALLOC_HIGH
)
2521 * If the caller does not have rights to ALLOC_HARDER then subtract
2522 * the high-atomic reserves. This will over-estimate the size of the
2523 * atomic reserve but it avoids a search.
2525 if (likely(!alloc_harder
))
2526 free_pages
-= z
->nr_reserved_highatomic
;
2531 /* If allocation can't use CMA areas don't use free CMA pages */
2532 if (!(alloc_flags
& ALLOC_CMA
))
2533 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2537 * Check watermarks for an order-0 allocation request. If these
2538 * are not met, then a high-order request also cannot go ahead
2539 * even if a suitable page happened to be free.
2541 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
2544 /* If this is an order-0 request then the watermark is fine */
2548 /* For a high-order request, check at least one suitable page is free */
2549 for (o
= order
; o
< MAX_ORDER
; o
++) {
2550 struct free_area
*area
= &z
->free_area
[o
];
2559 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
2560 if (!list_empty(&area
->free_list
[mt
]))
2565 if ((alloc_flags
& ALLOC_CMA
) &&
2566 !list_empty(&area
->free_list
[MIGRATE_CMA
])) {
2574 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2575 int classzone_idx
, int alloc_flags
)
2577 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
2578 zone_page_state(z
, NR_FREE_PAGES
));
2581 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
2582 unsigned long mark
, int classzone_idx
)
2584 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
2586 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
2587 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
2589 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, 0,
2594 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2596 return local_zone
->node
== zone
->node
;
2599 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2601 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <
2604 #else /* CONFIG_NUMA */
2605 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2610 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2614 #endif /* CONFIG_NUMA */
2616 static void reset_alloc_batches(struct zone
*preferred_zone
)
2618 struct zone
*zone
= preferred_zone
->zone_pgdat
->node_zones
;
2621 mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
2622 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
2623 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
2624 clear_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2625 } while (zone
++ != preferred_zone
);
2629 * get_page_from_freelist goes through the zonelist trying to allocate
2632 static struct page
*
2633 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
2634 const struct alloc_context
*ac
)
2636 struct zonelist
*zonelist
= ac
->zonelist
;
2638 struct page
*page
= NULL
;
2640 int nr_fair_skipped
= 0;
2641 bool zonelist_rescan
;
2644 zonelist_rescan
= false;
2647 * Scan zonelist, looking for a zone with enough free.
2648 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2650 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
2654 if (cpusets_enabled() &&
2655 (alloc_flags
& ALLOC_CPUSET
) &&
2656 !cpuset_zone_allowed(zone
, gfp_mask
))
2659 * Distribute pages in proportion to the individual
2660 * zone size to ensure fair page aging. The zone a
2661 * page was allocated in should have no effect on the
2662 * time the page has in memory before being reclaimed.
2664 if (alloc_flags
& ALLOC_FAIR
) {
2665 if (!zone_local(ac
->preferred_zone
, zone
))
2667 if (test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
)) {
2673 * When allocating a page cache page for writing, we
2674 * want to get it from a zone that is within its dirty
2675 * limit, such that no single zone holds more than its
2676 * proportional share of globally allowed dirty pages.
2677 * The dirty limits take into account the zone's
2678 * lowmem reserves and high watermark so that kswapd
2679 * should be able to balance it without having to
2680 * write pages from its LRU list.
2682 * This may look like it could increase pressure on
2683 * lower zones by failing allocations in higher zones
2684 * before they are full. But the pages that do spill
2685 * over are limited as the lower zones are protected
2686 * by this very same mechanism. It should not become
2687 * a practical burden to them.
2689 * XXX: For now, allow allocations to potentially
2690 * exceed the per-zone dirty limit in the slowpath
2691 * (spread_dirty_pages unset) before going into reclaim,
2692 * which is important when on a NUMA setup the allowed
2693 * zones are together not big enough to reach the
2694 * global limit. The proper fix for these situations
2695 * will require awareness of zones in the
2696 * dirty-throttling and the flusher threads.
2698 if (ac
->spread_dirty_pages
&& !zone_dirty_ok(zone
))
2701 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
2702 if (!zone_watermark_ok(zone
, order
, mark
,
2703 ac
->classzone_idx
, alloc_flags
)) {
2706 /* Checked here to keep the fast path fast */
2707 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
2708 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
2711 if (zone_reclaim_mode
== 0 ||
2712 !zone_allows_reclaim(ac
->preferred_zone
, zone
))
2715 ret
= zone_reclaim(zone
, gfp_mask
, order
);
2717 case ZONE_RECLAIM_NOSCAN
:
2720 case ZONE_RECLAIM_FULL
:
2721 /* scanned but unreclaimable */
2724 /* did we reclaim enough */
2725 if (zone_watermark_ok(zone
, order
, mark
,
2726 ac
->classzone_idx
, alloc_flags
))
2734 page
= buffered_rmqueue(ac
->preferred_zone
, zone
, order
,
2735 gfp_mask
, alloc_flags
, ac
->migratetype
);
2737 if (prep_new_page(page
, order
, gfp_mask
, alloc_flags
))
2741 * If this is a high-order atomic allocation then check
2742 * if the pageblock should be reserved for the future
2744 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
2745 reserve_highatomic_pageblock(page
, zone
, order
);
2752 * The first pass makes sure allocations are spread fairly within the
2753 * local node. However, the local node might have free pages left
2754 * after the fairness batches are exhausted, and remote zones haven't
2755 * even been considered yet. Try once more without fairness, and
2756 * include remote zones now, before entering the slowpath and waking
2757 * kswapd: prefer spilling to a remote zone over swapping locally.
2759 if (alloc_flags
& ALLOC_FAIR
) {
2760 alloc_flags
&= ~ALLOC_FAIR
;
2761 if (nr_fair_skipped
) {
2762 zonelist_rescan
= true;
2763 reset_alloc_batches(ac
->preferred_zone
);
2765 if (nr_online_nodes
> 1)
2766 zonelist_rescan
= true;
2769 if (zonelist_rescan
)
2776 * Large machines with many possible nodes should not always dump per-node
2777 * meminfo in irq context.
2779 static inline bool should_suppress_show_mem(void)
2784 ret
= in_interrupt();
2789 static DEFINE_RATELIMIT_STATE(nopage_rs
,
2790 DEFAULT_RATELIMIT_INTERVAL
,
2791 DEFAULT_RATELIMIT_BURST
);
2793 void warn_alloc_failed(gfp_t gfp_mask
, unsigned int order
, const char *fmt
, ...)
2795 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
2797 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
2798 debug_guardpage_minorder() > 0)
2802 * This documents exceptions given to allocations in certain
2803 * contexts that are allowed to allocate outside current's set
2806 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2807 if (test_thread_flag(TIF_MEMDIE
) ||
2808 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
2809 filter
&= ~SHOW_MEM_FILTER_NODES
;
2810 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
2811 filter
&= ~SHOW_MEM_FILTER_NODES
;
2814 struct va_format vaf
;
2817 va_start(args
, fmt
);
2822 pr_warn("%pV", &vaf
);
2827 pr_warn("%s: page allocation failure: order:%u, mode:%#x(%pGg)\n",
2828 current
->comm
, order
, gfp_mask
, &gfp_mask
);
2830 if (!should_suppress_show_mem())
2834 static inline struct page
*
2835 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
2836 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
2838 struct oom_control oc
= {
2839 .zonelist
= ac
->zonelist
,
2840 .nodemask
= ac
->nodemask
,
2841 .gfp_mask
= gfp_mask
,
2846 *did_some_progress
= 0;
2849 * Acquire the oom lock. If that fails, somebody else is
2850 * making progress for us.
2852 if (!mutex_trylock(&oom_lock
)) {
2853 *did_some_progress
= 1;
2854 schedule_timeout_uninterruptible(1);
2859 * Go through the zonelist yet one more time, keep very high watermark
2860 * here, this is only to catch a parallel oom killing, we must fail if
2861 * we're still under heavy pressure.
2863 page
= get_page_from_freelist(gfp_mask
| __GFP_HARDWALL
, order
,
2864 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
2868 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2869 /* Coredumps can quickly deplete all memory reserves */
2870 if (current
->flags
& PF_DUMPCORE
)
2872 /* The OOM killer will not help higher order allocs */
2873 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2875 /* The OOM killer does not needlessly kill tasks for lowmem */
2876 if (ac
->high_zoneidx
< ZONE_NORMAL
)
2878 /* The OOM killer does not compensate for IO-less reclaim */
2879 if (!(gfp_mask
& __GFP_FS
)) {
2881 * XXX: Page reclaim didn't yield anything,
2882 * and the OOM killer can't be invoked, but
2883 * keep looping as per tradition.
2885 * But do not keep looping if oom_killer_disable()
2886 * was already called, for the system is trying to
2887 * enter a quiescent state during suspend.
2889 *did_some_progress
= !oom_killer_disabled
;
2892 if (pm_suspended_storage())
2894 /* The OOM killer may not free memory on a specific node */
2895 if (gfp_mask
& __GFP_THISNODE
)
2898 /* Exhausted what can be done so it's blamo time */
2899 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
2900 *did_some_progress
= 1;
2902 if (gfp_mask
& __GFP_NOFAIL
) {
2903 page
= get_page_from_freelist(gfp_mask
, order
,
2904 ALLOC_NO_WATERMARKS
|ALLOC_CPUSET
, ac
);
2906 * fallback to ignore cpuset restriction if our nodes
2910 page
= get_page_from_freelist(gfp_mask
, order
,
2911 ALLOC_NO_WATERMARKS
, ac
);
2915 mutex_unlock(&oom_lock
);
2919 #ifdef CONFIG_COMPACTION
2920 /* Try memory compaction for high-order allocations before reclaim */
2921 static struct page
*
2922 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2923 int alloc_flags
, const struct alloc_context
*ac
,
2924 enum migrate_mode mode
, int *contended_compaction
,
2925 bool *deferred_compaction
)
2927 unsigned long compact_result
;
2933 current
->flags
|= PF_MEMALLOC
;
2934 compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
2935 mode
, contended_compaction
);
2936 current
->flags
&= ~PF_MEMALLOC
;
2938 switch (compact_result
) {
2939 case COMPACT_DEFERRED
:
2940 *deferred_compaction
= true;
2942 case COMPACT_SKIPPED
:
2949 * At least in one zone compaction wasn't deferred or skipped, so let's
2950 * count a compaction stall
2952 count_vm_event(COMPACTSTALL
);
2954 page
= get_page_from_freelist(gfp_mask
, order
,
2955 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
2958 struct zone
*zone
= page_zone(page
);
2960 zone
->compact_blockskip_flush
= false;
2961 compaction_defer_reset(zone
, order
, true);
2962 count_vm_event(COMPACTSUCCESS
);
2967 * It's bad if compaction run occurs and fails. The most likely reason
2968 * is that pages exist, but not enough to satisfy watermarks.
2970 count_vm_event(COMPACTFAIL
);
2977 static inline struct page
*
2978 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2979 int alloc_flags
, const struct alloc_context
*ac
,
2980 enum migrate_mode mode
, int *contended_compaction
,
2981 bool *deferred_compaction
)
2985 #endif /* CONFIG_COMPACTION */
2987 /* Perform direct synchronous page reclaim */
2989 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
2990 const struct alloc_context
*ac
)
2992 struct reclaim_state reclaim_state
;
2997 /* We now go into synchronous reclaim */
2998 cpuset_memory_pressure_bump();
2999 current
->flags
|= PF_MEMALLOC
;
3000 lockdep_set_current_reclaim_state(gfp_mask
);
3001 reclaim_state
.reclaimed_slab
= 0;
3002 current
->reclaim_state
= &reclaim_state
;
3004 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
3007 current
->reclaim_state
= NULL
;
3008 lockdep_clear_current_reclaim_state();
3009 current
->flags
&= ~PF_MEMALLOC
;
3016 /* The really slow allocator path where we enter direct reclaim */
3017 static inline struct page
*
3018 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
3019 int alloc_flags
, const struct alloc_context
*ac
,
3020 unsigned long *did_some_progress
)
3022 struct page
*page
= NULL
;
3023 bool drained
= false;
3025 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
3026 if (unlikely(!(*did_some_progress
)))
3030 page
= get_page_from_freelist(gfp_mask
, order
,
3031 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3034 * If an allocation failed after direct reclaim, it could be because
3035 * pages are pinned on the per-cpu lists or in high alloc reserves.
3036 * Shrink them them and try again
3038 if (!page
&& !drained
) {
3039 unreserve_highatomic_pageblock(ac
);
3040 drain_all_pages(NULL
);
3048 static void wake_all_kswapds(unsigned int order
, const struct alloc_context
*ac
)
3053 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
3054 ac
->high_zoneidx
, ac
->nodemask
)
3055 wakeup_kswapd(zone
, order
, zone_idx(ac
->preferred_zone
));
3059 gfp_to_alloc_flags(gfp_t gfp_mask
)
3061 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
3063 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3064 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
3067 * The caller may dip into page reserves a bit more if the caller
3068 * cannot run direct reclaim, or if the caller has realtime scheduling
3069 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3070 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3072 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
3074 if (gfp_mask
& __GFP_ATOMIC
) {
3076 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3077 * if it can't schedule.
3079 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3080 alloc_flags
|= ALLOC_HARDER
;
3082 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3083 * comment for __cpuset_node_allowed().
3085 alloc_flags
&= ~ALLOC_CPUSET
;
3086 } else if (unlikely(rt_task(current
)) && !in_interrupt())
3087 alloc_flags
|= ALLOC_HARDER
;
3089 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
3090 if (gfp_mask
& __GFP_MEMALLOC
)
3091 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3092 else if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
3093 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3094 else if (!in_interrupt() &&
3095 ((current
->flags
& PF_MEMALLOC
) ||
3096 unlikely(test_thread_flag(TIF_MEMDIE
))))
3097 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3100 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
3101 alloc_flags
|= ALLOC_CMA
;
3106 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
3108 return !!(gfp_to_alloc_flags(gfp_mask
) & ALLOC_NO_WATERMARKS
);
3111 static inline bool is_thp_gfp_mask(gfp_t gfp_mask
)
3113 return (gfp_mask
& (GFP_TRANSHUGE
| __GFP_KSWAPD_RECLAIM
)) == GFP_TRANSHUGE
;
3116 static inline struct page
*
3117 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
3118 struct alloc_context
*ac
)
3120 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
3121 struct page
*page
= NULL
;
3123 unsigned long pages_reclaimed
= 0;
3124 unsigned long did_some_progress
;
3125 enum migrate_mode migration_mode
= MIGRATE_ASYNC
;
3126 bool deferred_compaction
= false;
3127 int contended_compaction
= COMPACT_CONTENDED_NONE
;
3130 * In the slowpath, we sanity check order to avoid ever trying to
3131 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3132 * be using allocators in order of preference for an area that is
3135 if (order
>= MAX_ORDER
) {
3136 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
3141 * We also sanity check to catch abuse of atomic reserves being used by
3142 * callers that are not in atomic context.
3144 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
3145 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
3146 gfp_mask
&= ~__GFP_ATOMIC
;
3149 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3150 wake_all_kswapds(order
, ac
);
3153 * OK, we're below the kswapd watermark and have kicked background
3154 * reclaim. Now things get more complex, so set up alloc_flags according
3155 * to how we want to proceed.
3157 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
3160 * Find the true preferred zone if the allocation is unconstrained by
3163 if (!(alloc_flags
& ALLOC_CPUSET
) && !ac
->nodemask
) {
3164 struct zoneref
*preferred_zoneref
;
3165 preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3166 ac
->high_zoneidx
, NULL
, &ac
->preferred_zone
);
3167 ac
->classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
3170 /* This is the last chance, in general, before the goto nopage. */
3171 page
= get_page_from_freelist(gfp_mask
, order
,
3172 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3176 /* Allocate without watermarks if the context allows */
3177 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
3179 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
3180 * the allocation is high priority and these type of
3181 * allocations are system rather than user orientated
3183 ac
->zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
3184 page
= get_page_from_freelist(gfp_mask
, order
,
3185 ALLOC_NO_WATERMARKS
, ac
);
3190 /* Caller is not willing to reclaim, we can't balance anything */
3191 if (!can_direct_reclaim
) {
3193 * All existing users of the __GFP_NOFAIL are blockable, so warn
3194 * of any new users that actually allow this type of allocation
3197 WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
);
3201 /* Avoid recursion of direct reclaim */
3202 if (current
->flags
& PF_MEMALLOC
) {
3204 * __GFP_NOFAIL request from this context is rather bizarre
3205 * because we cannot reclaim anything and only can loop waiting
3206 * for somebody to do a work for us.
3208 if (WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3215 /* Avoid allocations with no watermarks from looping endlessly */
3216 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
3220 * Try direct compaction. The first pass is asynchronous. Subsequent
3221 * attempts after direct reclaim are synchronous
3223 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
3225 &contended_compaction
,
3226 &deferred_compaction
);
3230 /* Checks for THP-specific high-order allocations */
3231 if (is_thp_gfp_mask(gfp_mask
)) {
3233 * If compaction is deferred for high-order allocations, it is
3234 * because sync compaction recently failed. If this is the case
3235 * and the caller requested a THP allocation, we do not want
3236 * to heavily disrupt the system, so we fail the allocation
3237 * instead of entering direct reclaim.
3239 if (deferred_compaction
)
3243 * In all zones where compaction was attempted (and not
3244 * deferred or skipped), lock contention has been detected.
3245 * For THP allocation we do not want to disrupt the others
3246 * so we fallback to base pages instead.
3248 if (contended_compaction
== COMPACT_CONTENDED_LOCK
)
3252 * If compaction was aborted due to need_resched(), we do not
3253 * want to further increase allocation latency, unless it is
3254 * khugepaged trying to collapse.
3256 if (contended_compaction
== COMPACT_CONTENDED_SCHED
3257 && !(current
->flags
& PF_KTHREAD
))
3262 * It can become very expensive to allocate transparent hugepages at
3263 * fault, so use asynchronous memory compaction for THP unless it is
3264 * khugepaged trying to collapse.
3266 if (!is_thp_gfp_mask(gfp_mask
) || (current
->flags
& PF_KTHREAD
))
3267 migration_mode
= MIGRATE_SYNC_LIGHT
;
3269 /* Try direct reclaim and then allocating */
3270 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
3271 &did_some_progress
);
3275 /* Do not loop if specifically requested */
3276 if (gfp_mask
& __GFP_NORETRY
)
3279 /* Keep reclaiming pages as long as there is reasonable progress */
3280 pages_reclaimed
+= did_some_progress
;
3281 if ((did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
) ||
3282 ((gfp_mask
& __GFP_REPEAT
) && pages_reclaimed
< (1 << order
))) {
3283 /* Wait for some write requests to complete then retry */
3284 wait_iff_congested(ac
->preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
3288 /* Reclaim has failed us, start killing things */
3289 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
3293 /* Retry as long as the OOM killer is making progress */
3294 if (did_some_progress
)
3299 * High-order allocations do not necessarily loop after
3300 * direct reclaim and reclaim/compaction depends on compaction
3301 * being called after reclaim so call directly if necessary
3303 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
,
3305 &contended_compaction
,
3306 &deferred_compaction
);
3310 warn_alloc_failed(gfp_mask
, order
, NULL
);
3316 * This is the 'heart' of the zoned buddy allocator.
3319 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
3320 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
3322 struct zoneref
*preferred_zoneref
;
3323 struct page
*page
= NULL
;
3324 unsigned int cpuset_mems_cookie
;
3325 int alloc_flags
= ALLOC_WMARK_LOW
|ALLOC_CPUSET
|ALLOC_FAIR
;
3326 gfp_t alloc_mask
; /* The gfp_t that was actually used for allocation */
3327 struct alloc_context ac
= {
3328 .high_zoneidx
= gfp_zone(gfp_mask
),
3329 .nodemask
= nodemask
,
3330 .migratetype
= gfpflags_to_migratetype(gfp_mask
),
3333 gfp_mask
&= gfp_allowed_mask
;
3335 lockdep_trace_alloc(gfp_mask
);
3337 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
3339 if (should_fail_alloc_page(gfp_mask
, order
))
3343 * Check the zones suitable for the gfp_mask contain at least one
3344 * valid zone. It's possible to have an empty zonelist as a result
3345 * of __GFP_THISNODE and a memoryless node
3347 if (unlikely(!zonelist
->_zonerefs
->zone
))
3350 if (IS_ENABLED(CONFIG_CMA
) && ac
.migratetype
== MIGRATE_MOVABLE
)
3351 alloc_flags
|= ALLOC_CMA
;
3354 cpuset_mems_cookie
= read_mems_allowed_begin();
3356 /* We set it here, as __alloc_pages_slowpath might have changed it */
3357 ac
.zonelist
= zonelist
;
3359 /* Dirty zone balancing only done in the fast path */
3360 ac
.spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
3362 /* The preferred zone is used for statistics later */
3363 preferred_zoneref
= first_zones_zonelist(ac
.zonelist
, ac
.high_zoneidx
,
3364 ac
.nodemask
? : &cpuset_current_mems_allowed
,
3365 &ac
.preferred_zone
);
3366 if (!ac
.preferred_zone
)
3368 ac
.classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
3370 /* First allocation attempt */
3371 alloc_mask
= gfp_mask
|__GFP_HARDWALL
;
3372 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
3373 if (unlikely(!page
)) {
3375 * Runtime PM, block IO and its error handling path
3376 * can deadlock because I/O on the device might not
3379 alloc_mask
= memalloc_noio_flags(gfp_mask
);
3380 ac
.spread_dirty_pages
= false;
3382 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
3385 if (kmemcheck_enabled
&& page
)
3386 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
3388 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
3392 * When updating a task's mems_allowed, it is possible to race with
3393 * parallel threads in such a way that an allocation can fail while
3394 * the mask is being updated. If a page allocation is about to fail,
3395 * check if the cpuset changed during allocation and if so, retry.
3397 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
)))
3402 EXPORT_SYMBOL(__alloc_pages_nodemask
);
3405 * Common helper functions.
3407 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
3412 * __get_free_pages() returns a 32-bit address, which cannot represent
3415 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
3417 page
= alloc_pages(gfp_mask
, order
);
3420 return (unsigned long) page_address(page
);
3422 EXPORT_SYMBOL(__get_free_pages
);
3424 unsigned long get_zeroed_page(gfp_t gfp_mask
)
3426 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
3428 EXPORT_SYMBOL(get_zeroed_page
);
3430 void __free_pages(struct page
*page
, unsigned int order
)
3432 if (put_page_testzero(page
)) {
3434 free_hot_cold_page(page
, false);
3436 __free_pages_ok(page
, order
);
3440 EXPORT_SYMBOL(__free_pages
);
3442 void free_pages(unsigned long addr
, unsigned int order
)
3445 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3446 __free_pages(virt_to_page((void *)addr
), order
);
3450 EXPORT_SYMBOL(free_pages
);
3454 * An arbitrary-length arbitrary-offset area of memory which resides
3455 * within a 0 or higher order page. Multiple fragments within that page
3456 * are individually refcounted, in the page's reference counter.
3458 * The page_frag functions below provide a simple allocation framework for
3459 * page fragments. This is used by the network stack and network device
3460 * drivers to provide a backing region of memory for use as either an
3461 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3463 static struct page
*__page_frag_refill(struct page_frag_cache
*nc
,
3466 struct page
*page
= NULL
;
3467 gfp_t gfp
= gfp_mask
;
3469 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3470 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
3472 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
3473 PAGE_FRAG_CACHE_MAX_ORDER
);
3474 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
3476 if (unlikely(!page
))
3477 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
3479 nc
->va
= page
? page_address(page
) : NULL
;
3484 void *__alloc_page_frag(struct page_frag_cache
*nc
,
3485 unsigned int fragsz
, gfp_t gfp_mask
)
3487 unsigned int size
= PAGE_SIZE
;
3491 if (unlikely(!nc
->va
)) {
3493 page
= __page_frag_refill(nc
, gfp_mask
);
3497 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3498 /* if size can vary use size else just use PAGE_SIZE */
3501 /* Even if we own the page, we do not use atomic_set().
3502 * This would break get_page_unless_zero() users.
3504 page_ref_add(page
, size
- 1);
3506 /* reset page count bias and offset to start of new frag */
3507 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
3508 nc
->pagecnt_bias
= size
;
3512 offset
= nc
->offset
- fragsz
;
3513 if (unlikely(offset
< 0)) {
3514 page
= virt_to_page(nc
->va
);
3516 if (!page_ref_sub_and_test(page
, nc
->pagecnt_bias
))
3519 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3520 /* if size can vary use size else just use PAGE_SIZE */
3523 /* OK, page count is 0, we can safely set it */
3524 set_page_count(page
, size
);
3526 /* reset page count bias and offset to start of new frag */
3527 nc
->pagecnt_bias
= size
;
3528 offset
= size
- fragsz
;
3532 nc
->offset
= offset
;
3534 return nc
->va
+ offset
;
3536 EXPORT_SYMBOL(__alloc_page_frag
);
3539 * Frees a page fragment allocated out of either a compound or order 0 page.
3541 void __free_page_frag(void *addr
)
3543 struct page
*page
= virt_to_head_page(addr
);
3545 if (unlikely(put_page_testzero(page
)))
3546 __free_pages_ok(page
, compound_order(page
));
3548 EXPORT_SYMBOL(__free_page_frag
);
3551 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
3552 * of the current memory cgroup if __GFP_ACCOUNT is set, other than that it is
3553 * equivalent to alloc_pages.
3555 * It should be used when the caller would like to use kmalloc, but since the
3556 * allocation is large, it has to fall back to the page allocator.
3558 struct page
*alloc_kmem_pages(gfp_t gfp_mask
, unsigned int order
)
3562 page
= alloc_pages(gfp_mask
, order
);
3563 if (page
&& memcg_kmem_charge(page
, gfp_mask
, order
) != 0) {
3564 __free_pages(page
, order
);
3570 struct page
*alloc_kmem_pages_node(int nid
, gfp_t gfp_mask
, unsigned int order
)
3574 page
= alloc_pages_node(nid
, gfp_mask
, order
);
3575 if (page
&& memcg_kmem_charge(page
, gfp_mask
, order
) != 0) {
3576 __free_pages(page
, order
);
3583 * __free_kmem_pages and free_kmem_pages will free pages allocated with
3586 void __free_kmem_pages(struct page
*page
, unsigned int order
)
3588 memcg_kmem_uncharge(page
, order
);
3589 __free_pages(page
, order
);
3592 void free_kmem_pages(unsigned long addr
, unsigned int order
)
3595 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3596 __free_kmem_pages(virt_to_page((void *)addr
), order
);
3600 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
3604 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
3605 unsigned long used
= addr
+ PAGE_ALIGN(size
);
3607 split_page(virt_to_page((void *)addr
), order
);
3608 while (used
< alloc_end
) {
3613 return (void *)addr
;
3617 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
3618 * @size: the number of bytes to allocate
3619 * @gfp_mask: GFP flags for the allocation
3621 * This function is similar to alloc_pages(), except that it allocates the
3622 * minimum number of pages to satisfy the request. alloc_pages() can only
3623 * allocate memory in power-of-two pages.
3625 * This function is also limited by MAX_ORDER.
3627 * Memory allocated by this function must be released by free_pages_exact().
3629 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
3631 unsigned int order
= get_order(size
);
3634 addr
= __get_free_pages(gfp_mask
, order
);
3635 return make_alloc_exact(addr
, order
, size
);
3637 EXPORT_SYMBOL(alloc_pages_exact
);
3640 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3642 * @nid: the preferred node ID where memory should be allocated
3643 * @size: the number of bytes to allocate
3644 * @gfp_mask: GFP flags for the allocation
3646 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3649 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
3651 unsigned int order
= get_order(size
);
3652 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
3655 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
3659 * free_pages_exact - release memory allocated via alloc_pages_exact()
3660 * @virt: the value returned by alloc_pages_exact.
3661 * @size: size of allocation, same value as passed to alloc_pages_exact().
3663 * Release the memory allocated by a previous call to alloc_pages_exact.
3665 void free_pages_exact(void *virt
, size_t size
)
3667 unsigned long addr
= (unsigned long)virt
;
3668 unsigned long end
= addr
+ PAGE_ALIGN(size
);
3670 while (addr
< end
) {
3675 EXPORT_SYMBOL(free_pages_exact
);
3678 * nr_free_zone_pages - count number of pages beyond high watermark
3679 * @offset: The zone index of the highest zone
3681 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3682 * high watermark within all zones at or below a given zone index. For each
3683 * zone, the number of pages is calculated as:
3684 * managed_pages - high_pages
3686 static unsigned long nr_free_zone_pages(int offset
)
3691 /* Just pick one node, since fallback list is circular */
3692 unsigned long sum
= 0;
3694 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
3696 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
3697 unsigned long size
= zone
->managed_pages
;
3698 unsigned long high
= high_wmark_pages(zone
);
3707 * nr_free_buffer_pages - count number of pages beyond high watermark
3709 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3710 * watermark within ZONE_DMA and ZONE_NORMAL.
3712 unsigned long nr_free_buffer_pages(void)
3714 return nr_free_zone_pages(gfp_zone(GFP_USER
));
3716 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
3719 * nr_free_pagecache_pages - count number of pages beyond high watermark
3721 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3722 * high watermark within all zones.
3724 unsigned long nr_free_pagecache_pages(void)
3726 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
3729 static inline void show_node(struct zone
*zone
)
3731 if (IS_ENABLED(CONFIG_NUMA
))
3732 printk("Node %d ", zone_to_nid(zone
));
3735 long si_mem_available(void)
3738 unsigned long pagecache
;
3739 unsigned long wmark_low
= 0;
3740 unsigned long pages
[NR_LRU_LISTS
];
3744 for (lru
= LRU_BASE
; lru
< NR_LRU_LISTS
; lru
++)
3745 pages
[lru
] = global_page_state(NR_LRU_BASE
+ lru
);
3748 wmark_low
+= zone
->watermark
[WMARK_LOW
];
3751 * Estimate the amount of memory available for userspace allocations,
3752 * without causing swapping.
3754 available
= global_page_state(NR_FREE_PAGES
) - totalreserve_pages
;
3757 * Not all the page cache can be freed, otherwise the system will
3758 * start swapping. Assume at least half of the page cache, or the
3759 * low watermark worth of cache, needs to stay.
3761 pagecache
= pages
[LRU_ACTIVE_FILE
] + pages
[LRU_INACTIVE_FILE
];
3762 pagecache
-= min(pagecache
/ 2, wmark_low
);
3763 available
+= pagecache
;
3766 * Part of the reclaimable slab consists of items that are in use,
3767 * and cannot be freed. Cap this estimate at the low watermark.
3769 available
+= global_page_state(NR_SLAB_RECLAIMABLE
) -
3770 min(global_page_state(NR_SLAB_RECLAIMABLE
) / 2, wmark_low
);
3776 EXPORT_SYMBOL_GPL(si_mem_available
);
3778 void si_meminfo(struct sysinfo
*val
)
3780 val
->totalram
= totalram_pages
;
3781 val
->sharedram
= global_page_state(NR_SHMEM
);
3782 val
->freeram
= global_page_state(NR_FREE_PAGES
);
3783 val
->bufferram
= nr_blockdev_pages();
3784 val
->totalhigh
= totalhigh_pages
;
3785 val
->freehigh
= nr_free_highpages();
3786 val
->mem_unit
= PAGE_SIZE
;
3789 EXPORT_SYMBOL(si_meminfo
);
3792 void si_meminfo_node(struct sysinfo
*val
, int nid
)
3794 int zone_type
; /* needs to be signed */
3795 unsigned long managed_pages
= 0;
3796 unsigned long managed_highpages
= 0;
3797 unsigned long free_highpages
= 0;
3798 pg_data_t
*pgdat
= NODE_DATA(nid
);
3800 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
3801 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
3802 val
->totalram
= managed_pages
;
3803 val
->sharedram
= node_page_state(nid
, NR_SHMEM
);
3804 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
3805 #ifdef CONFIG_HIGHMEM
3806 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
3807 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
3809 if (is_highmem(zone
)) {
3810 managed_highpages
+= zone
->managed_pages
;
3811 free_highpages
+= zone_page_state(zone
, NR_FREE_PAGES
);
3814 val
->totalhigh
= managed_highpages
;
3815 val
->freehigh
= free_highpages
;
3817 val
->totalhigh
= managed_highpages
;
3818 val
->freehigh
= free_highpages
;
3820 val
->mem_unit
= PAGE_SIZE
;
3825 * Determine whether the node should be displayed or not, depending on whether
3826 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3828 bool skip_free_areas_node(unsigned int flags
, int nid
)
3831 unsigned int cpuset_mems_cookie
;
3833 if (!(flags
& SHOW_MEM_FILTER_NODES
))
3837 cpuset_mems_cookie
= read_mems_allowed_begin();
3838 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
3839 } while (read_mems_allowed_retry(cpuset_mems_cookie
));
3844 #define K(x) ((x) << (PAGE_SHIFT-10))
3846 static void show_migration_types(unsigned char type
)
3848 static const char types
[MIGRATE_TYPES
] = {
3849 [MIGRATE_UNMOVABLE
] = 'U',
3850 [MIGRATE_MOVABLE
] = 'M',
3851 [MIGRATE_RECLAIMABLE
] = 'E',
3852 [MIGRATE_HIGHATOMIC
] = 'H',
3854 [MIGRATE_CMA
] = 'C',
3856 #ifdef CONFIG_MEMORY_ISOLATION
3857 [MIGRATE_ISOLATE
] = 'I',
3860 char tmp
[MIGRATE_TYPES
+ 1];
3864 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
3865 if (type
& (1 << i
))
3870 printk("(%s) ", tmp
);
3874 * Show free area list (used inside shift_scroll-lock stuff)
3875 * We also calculate the percentage fragmentation. We do this by counting the
3876 * memory on each free list with the exception of the first item on the list.
3879 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
3882 void show_free_areas(unsigned int filter
)
3884 unsigned long free_pcp
= 0;
3888 for_each_populated_zone(zone
) {
3889 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3892 for_each_online_cpu(cpu
)
3893 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
3896 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3897 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3898 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
3899 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3900 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3901 " free:%lu free_pcp:%lu free_cma:%lu\n",
3902 global_page_state(NR_ACTIVE_ANON
),
3903 global_page_state(NR_INACTIVE_ANON
),
3904 global_page_state(NR_ISOLATED_ANON
),
3905 global_page_state(NR_ACTIVE_FILE
),
3906 global_page_state(NR_INACTIVE_FILE
),
3907 global_page_state(NR_ISOLATED_FILE
),
3908 global_page_state(NR_UNEVICTABLE
),
3909 global_page_state(NR_FILE_DIRTY
),
3910 global_page_state(NR_WRITEBACK
),
3911 global_page_state(NR_UNSTABLE_NFS
),
3912 global_page_state(NR_SLAB_RECLAIMABLE
),
3913 global_page_state(NR_SLAB_UNRECLAIMABLE
),
3914 global_page_state(NR_FILE_MAPPED
),
3915 global_page_state(NR_SHMEM
),
3916 global_page_state(NR_PAGETABLE
),
3917 global_page_state(NR_BOUNCE
),
3918 global_page_state(NR_FREE_PAGES
),
3920 global_page_state(NR_FREE_CMA_PAGES
));
3922 for_each_populated_zone(zone
) {
3925 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3929 for_each_online_cpu(cpu
)
3930 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
3938 " active_anon:%lukB"
3939 " inactive_anon:%lukB"
3940 " active_file:%lukB"
3941 " inactive_file:%lukB"
3942 " unevictable:%lukB"
3943 " isolated(anon):%lukB"
3944 " isolated(file):%lukB"
3952 " slab_reclaimable:%lukB"
3953 " slab_unreclaimable:%lukB"
3954 " kernel_stack:%lukB"
3961 " writeback_tmp:%lukB"
3962 " pages_scanned:%lu"
3963 " all_unreclaimable? %s"
3966 K(zone_page_state(zone
, NR_FREE_PAGES
)),
3967 K(min_wmark_pages(zone
)),
3968 K(low_wmark_pages(zone
)),
3969 K(high_wmark_pages(zone
)),
3970 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
3971 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
3972 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
3973 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
3974 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
3975 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
3976 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
3977 K(zone
->present_pages
),
3978 K(zone
->managed_pages
),
3979 K(zone_page_state(zone
, NR_MLOCK
)),
3980 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
3981 K(zone_page_state(zone
, NR_WRITEBACK
)),
3982 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
3983 K(zone_page_state(zone
, NR_SHMEM
)),
3984 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
3985 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
3986 zone_page_state(zone
, NR_KERNEL_STACK
) *
3988 K(zone_page_state(zone
, NR_PAGETABLE
)),
3989 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
3990 K(zone_page_state(zone
, NR_BOUNCE
)),
3992 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
3993 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)),
3994 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
3995 K(zone_page_state(zone
, NR_PAGES_SCANNED
)),
3996 (!zone_reclaimable(zone
) ? "yes" : "no")
3998 printk("lowmem_reserve[]:");
3999 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4000 printk(" %ld", zone
->lowmem_reserve
[i
]);
4004 for_each_populated_zone(zone
) {
4006 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
4007 unsigned char types
[MAX_ORDER
];
4009 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
4012 printk("%s: ", zone
->name
);
4014 spin_lock_irqsave(&zone
->lock
, flags
);
4015 for (order
= 0; order
< MAX_ORDER
; order
++) {
4016 struct free_area
*area
= &zone
->free_area
[order
];
4019 nr
[order
] = area
->nr_free
;
4020 total
+= nr
[order
] << order
;
4023 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
4024 if (!list_empty(&area
->free_list
[type
]))
4025 types
[order
] |= 1 << type
;
4028 spin_unlock_irqrestore(&zone
->lock
, flags
);
4029 for (order
= 0; order
< MAX_ORDER
; order
++) {
4030 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
4032 show_migration_types(types
[order
]);
4034 printk("= %lukB\n", K(total
));
4037 hugetlb_show_meminfo();
4039 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
4041 show_swap_cache_info();
4044 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
4046 zoneref
->zone
= zone
;
4047 zoneref
->zone_idx
= zone_idx(zone
);
4051 * Builds allocation fallback zone lists.
4053 * Add all populated zones of a node to the zonelist.
4055 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
4059 enum zone_type zone_type
= MAX_NR_ZONES
;
4063 zone
= pgdat
->node_zones
+ zone_type
;
4064 if (populated_zone(zone
)) {
4065 zoneref_set_zone(zone
,
4066 &zonelist
->_zonerefs
[nr_zones
++]);
4067 check_highest_zone(zone_type
);
4069 } while (zone_type
);
4077 * 0 = automatic detection of better ordering.
4078 * 1 = order by ([node] distance, -zonetype)
4079 * 2 = order by (-zonetype, [node] distance)
4081 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4082 * the same zonelist. So only NUMA can configure this param.
4084 #define ZONELIST_ORDER_DEFAULT 0
4085 #define ZONELIST_ORDER_NODE 1
4086 #define ZONELIST_ORDER_ZONE 2
4088 /* zonelist order in the kernel.
4089 * set_zonelist_order() will set this to NODE or ZONE.
4091 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4092 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
4096 /* The value user specified ....changed by config */
4097 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4098 /* string for sysctl */
4099 #define NUMA_ZONELIST_ORDER_LEN 16
4100 char numa_zonelist_order
[16] = "default";
4103 * interface for configure zonelist ordering.
4104 * command line option "numa_zonelist_order"
4105 * = "[dD]efault - default, automatic configuration.
4106 * = "[nN]ode - order by node locality, then by zone within node
4107 * = "[zZ]one - order by zone, then by locality within zone
4110 static int __parse_numa_zonelist_order(char *s
)
4112 if (*s
== 'd' || *s
== 'D') {
4113 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4114 } else if (*s
== 'n' || *s
== 'N') {
4115 user_zonelist_order
= ZONELIST_ORDER_NODE
;
4116 } else if (*s
== 'z' || *s
== 'Z') {
4117 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
4119 pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s
);
4125 static __init
int setup_numa_zonelist_order(char *s
)
4132 ret
= __parse_numa_zonelist_order(s
);
4134 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
4138 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
4141 * sysctl handler for numa_zonelist_order
4143 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
4144 void __user
*buffer
, size_t *length
,
4147 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
4149 static DEFINE_MUTEX(zl_order_mutex
);
4151 mutex_lock(&zl_order_mutex
);
4153 if (strlen((char *)table
->data
) >= NUMA_ZONELIST_ORDER_LEN
) {
4157 strcpy(saved_string
, (char *)table
->data
);
4159 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
4163 int oldval
= user_zonelist_order
;
4165 ret
= __parse_numa_zonelist_order((char *)table
->data
);
4168 * bogus value. restore saved string
4170 strncpy((char *)table
->data
, saved_string
,
4171 NUMA_ZONELIST_ORDER_LEN
);
4172 user_zonelist_order
= oldval
;
4173 } else if (oldval
!= user_zonelist_order
) {
4174 mutex_lock(&zonelists_mutex
);
4175 build_all_zonelists(NULL
, NULL
);
4176 mutex_unlock(&zonelists_mutex
);
4180 mutex_unlock(&zl_order_mutex
);
4185 #define MAX_NODE_LOAD (nr_online_nodes)
4186 static int node_load
[MAX_NUMNODES
];
4189 * find_next_best_node - find the next node that should appear in a given node's fallback list
4190 * @node: node whose fallback list we're appending
4191 * @used_node_mask: nodemask_t of already used nodes
4193 * We use a number of factors to determine which is the next node that should
4194 * appear on a given node's fallback list. The node should not have appeared
4195 * already in @node's fallback list, and it should be the next closest node
4196 * according to the distance array (which contains arbitrary distance values
4197 * from each node to each node in the system), and should also prefer nodes
4198 * with no CPUs, since presumably they'll have very little allocation pressure
4199 * on them otherwise.
4200 * It returns -1 if no node is found.
4202 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
4205 int min_val
= INT_MAX
;
4206 int best_node
= NUMA_NO_NODE
;
4207 const struct cpumask
*tmp
= cpumask_of_node(0);
4209 /* Use the local node if we haven't already */
4210 if (!node_isset(node
, *used_node_mask
)) {
4211 node_set(node
, *used_node_mask
);
4215 for_each_node_state(n
, N_MEMORY
) {
4217 /* Don't want a node to appear more than once */
4218 if (node_isset(n
, *used_node_mask
))
4221 /* Use the distance array to find the distance */
4222 val
= node_distance(node
, n
);
4224 /* Penalize nodes under us ("prefer the next node") */
4227 /* Give preference to headless and unused nodes */
4228 tmp
= cpumask_of_node(n
);
4229 if (!cpumask_empty(tmp
))
4230 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
4232 /* Slight preference for less loaded node */
4233 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
4234 val
+= node_load
[n
];
4236 if (val
< min_val
) {
4243 node_set(best_node
, *used_node_mask
);
4250 * Build zonelists ordered by node and zones within node.
4251 * This results in maximum locality--normal zone overflows into local
4252 * DMA zone, if any--but risks exhausting DMA zone.
4254 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
4257 struct zonelist
*zonelist
;
4259 zonelist
= &pgdat
->node_zonelists
[0];
4260 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
4262 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4263 zonelist
->_zonerefs
[j
].zone
= NULL
;
4264 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4268 * Build gfp_thisnode zonelists
4270 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
4273 struct zonelist
*zonelist
;
4275 zonelist
= &pgdat
->node_zonelists
[1];
4276 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4277 zonelist
->_zonerefs
[j
].zone
= NULL
;
4278 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4282 * Build zonelists ordered by zone and nodes within zones.
4283 * This results in conserving DMA zone[s] until all Normal memory is
4284 * exhausted, but results in overflowing to remote node while memory
4285 * may still exist in local DMA zone.
4287 static int node_order
[MAX_NUMNODES
];
4289 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
4292 int zone_type
; /* needs to be signed */
4294 struct zonelist
*zonelist
;
4296 zonelist
= &pgdat
->node_zonelists
[0];
4298 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
4299 for (j
= 0; j
< nr_nodes
; j
++) {
4300 node
= node_order
[j
];
4301 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
4302 if (populated_zone(z
)) {
4304 &zonelist
->_zonerefs
[pos
++]);
4305 check_highest_zone(zone_type
);
4309 zonelist
->_zonerefs
[pos
].zone
= NULL
;
4310 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
4313 #if defined(CONFIG_64BIT)
4315 * Devices that require DMA32/DMA are relatively rare and do not justify a
4316 * penalty to every machine in case the specialised case applies. Default
4317 * to Node-ordering on 64-bit NUMA machines
4319 static int default_zonelist_order(void)
4321 return ZONELIST_ORDER_NODE
;
4325 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4326 * by the kernel. If processes running on node 0 deplete the low memory zone
4327 * then reclaim will occur more frequency increasing stalls and potentially
4328 * be easier to OOM if a large percentage of the zone is under writeback or
4329 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4330 * Hence, default to zone ordering on 32-bit.
4332 static int default_zonelist_order(void)
4334 return ZONELIST_ORDER_ZONE
;
4336 #endif /* CONFIG_64BIT */
4338 static void set_zonelist_order(void)
4340 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
4341 current_zonelist_order
= default_zonelist_order();
4343 current_zonelist_order
= user_zonelist_order
;
4346 static void build_zonelists(pg_data_t
*pgdat
)
4349 nodemask_t used_mask
;
4350 int local_node
, prev_node
;
4351 struct zonelist
*zonelist
;
4352 unsigned int order
= current_zonelist_order
;
4354 /* initialize zonelists */
4355 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
4356 zonelist
= pgdat
->node_zonelists
+ i
;
4357 zonelist
->_zonerefs
[0].zone
= NULL
;
4358 zonelist
->_zonerefs
[0].zone_idx
= 0;
4361 /* NUMA-aware ordering of nodes */
4362 local_node
= pgdat
->node_id
;
4363 load
= nr_online_nodes
;
4364 prev_node
= local_node
;
4365 nodes_clear(used_mask
);
4367 memset(node_order
, 0, sizeof(node_order
));
4370 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
4372 * We don't want to pressure a particular node.
4373 * So adding penalty to the first node in same
4374 * distance group to make it round-robin.
4376 if (node_distance(local_node
, node
) !=
4377 node_distance(local_node
, prev_node
))
4378 node_load
[node
] = load
;
4382 if (order
== ZONELIST_ORDER_NODE
)
4383 build_zonelists_in_node_order(pgdat
, node
);
4385 node_order
[i
++] = node
; /* remember order */
4388 if (order
== ZONELIST_ORDER_ZONE
) {
4389 /* calculate node order -- i.e., DMA last! */
4390 build_zonelists_in_zone_order(pgdat
, i
);
4393 build_thisnode_zonelists(pgdat
);
4396 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4398 * Return node id of node used for "local" allocations.
4399 * I.e., first node id of first zone in arg node's generic zonelist.
4400 * Used for initializing percpu 'numa_mem', which is used primarily
4401 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4403 int local_memory_node(int node
)
4407 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
4408 gfp_zone(GFP_KERNEL
),
4415 #else /* CONFIG_NUMA */
4417 static void set_zonelist_order(void)
4419 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
4422 static void build_zonelists(pg_data_t
*pgdat
)
4424 int node
, local_node
;
4426 struct zonelist
*zonelist
;
4428 local_node
= pgdat
->node_id
;
4430 zonelist
= &pgdat
->node_zonelists
[0];
4431 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4434 * Now we build the zonelist so that it contains the zones
4435 * of all the other nodes.
4436 * We don't want to pressure a particular node, so when
4437 * building the zones for node N, we make sure that the
4438 * zones coming right after the local ones are those from
4439 * node N+1 (modulo N)
4441 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
4442 if (!node_online(node
))
4444 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4446 for (node
= 0; node
< local_node
; node
++) {
4447 if (!node_online(node
))
4449 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4452 zonelist
->_zonerefs
[j
].zone
= NULL
;
4453 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4456 #endif /* CONFIG_NUMA */
4459 * Boot pageset table. One per cpu which is going to be used for all
4460 * zones and all nodes. The parameters will be set in such a way
4461 * that an item put on a list will immediately be handed over to
4462 * the buddy list. This is safe since pageset manipulation is done
4463 * with interrupts disabled.
4465 * The boot_pagesets must be kept even after bootup is complete for
4466 * unused processors and/or zones. They do play a role for bootstrapping
4467 * hotplugged processors.
4469 * zoneinfo_show() and maybe other functions do
4470 * not check if the processor is online before following the pageset pointer.
4471 * Other parts of the kernel may not check if the zone is available.
4473 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
4474 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
4475 static void setup_zone_pageset(struct zone
*zone
);
4478 * Global mutex to protect against size modification of zonelists
4479 * as well as to serialize pageset setup for the new populated zone.
4481 DEFINE_MUTEX(zonelists_mutex
);
4483 /* return values int ....just for stop_machine() */
4484 static int __build_all_zonelists(void *data
)
4488 pg_data_t
*self
= data
;
4491 memset(node_load
, 0, sizeof(node_load
));
4494 if (self
&& !node_online(self
->node_id
)) {
4495 build_zonelists(self
);
4498 for_each_online_node(nid
) {
4499 pg_data_t
*pgdat
= NODE_DATA(nid
);
4501 build_zonelists(pgdat
);
4505 * Initialize the boot_pagesets that are going to be used
4506 * for bootstrapping processors. The real pagesets for
4507 * each zone will be allocated later when the per cpu
4508 * allocator is available.
4510 * boot_pagesets are used also for bootstrapping offline
4511 * cpus if the system is already booted because the pagesets
4512 * are needed to initialize allocators on a specific cpu too.
4513 * F.e. the percpu allocator needs the page allocator which
4514 * needs the percpu allocator in order to allocate its pagesets
4515 * (a chicken-egg dilemma).
4517 for_each_possible_cpu(cpu
) {
4518 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
4520 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4522 * We now know the "local memory node" for each node--
4523 * i.e., the node of the first zone in the generic zonelist.
4524 * Set up numa_mem percpu variable for on-line cpus. During
4525 * boot, only the boot cpu should be on-line; we'll init the
4526 * secondary cpus' numa_mem as they come on-line. During
4527 * node/memory hotplug, we'll fixup all on-line cpus.
4529 if (cpu_online(cpu
))
4530 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
4537 static noinline
void __init
4538 build_all_zonelists_init(void)
4540 __build_all_zonelists(NULL
);
4541 mminit_verify_zonelist();
4542 cpuset_init_current_mems_allowed();
4546 * Called with zonelists_mutex held always
4547 * unless system_state == SYSTEM_BOOTING.
4549 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4550 * [we're only called with non-NULL zone through __meminit paths] and
4551 * (2) call of __init annotated helper build_all_zonelists_init
4552 * [protected by SYSTEM_BOOTING].
4554 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
4556 set_zonelist_order();
4558 if (system_state
== SYSTEM_BOOTING
) {
4559 build_all_zonelists_init();
4561 #ifdef CONFIG_MEMORY_HOTPLUG
4563 setup_zone_pageset(zone
);
4565 /* we have to stop all cpus to guarantee there is no user
4567 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
4568 /* cpuset refresh routine should be here */
4570 vm_total_pages
= nr_free_pagecache_pages();
4572 * Disable grouping by mobility if the number of pages in the
4573 * system is too low to allow the mechanism to work. It would be
4574 * more accurate, but expensive to check per-zone. This check is
4575 * made on memory-hotadd so a system can start with mobility
4576 * disabled and enable it later
4578 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
4579 page_group_by_mobility_disabled
= 1;
4581 page_group_by_mobility_disabled
= 0;
4583 pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n",
4585 zonelist_order_name
[current_zonelist_order
],
4586 page_group_by_mobility_disabled
? "off" : "on",
4589 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
4594 * Helper functions to size the waitqueue hash table.
4595 * Essentially these want to choose hash table sizes sufficiently
4596 * large so that collisions trying to wait on pages are rare.
4597 * But in fact, the number of active page waitqueues on typical
4598 * systems is ridiculously low, less than 200. So this is even
4599 * conservative, even though it seems large.
4601 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
4602 * waitqueues, i.e. the size of the waitq table given the number of pages.
4604 #define PAGES_PER_WAITQUEUE 256
4606 #ifndef CONFIG_MEMORY_HOTPLUG
4607 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
4609 unsigned long size
= 1;
4611 pages
/= PAGES_PER_WAITQUEUE
;
4613 while (size
< pages
)
4617 * Once we have dozens or even hundreds of threads sleeping
4618 * on IO we've got bigger problems than wait queue collision.
4619 * Limit the size of the wait table to a reasonable size.
4621 size
= min(size
, 4096UL);
4623 return max(size
, 4UL);
4627 * A zone's size might be changed by hot-add, so it is not possible to determine
4628 * a suitable size for its wait_table. So we use the maximum size now.
4630 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
4632 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
4633 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
4634 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
4636 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
4637 * or more by the traditional way. (See above). It equals:
4639 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
4640 * ia64(16K page size) : = ( 8G + 4M)byte.
4641 * powerpc (64K page size) : = (32G +16M)byte.
4643 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
4650 * This is an integer logarithm so that shifts can be used later
4651 * to extract the more random high bits from the multiplicative
4652 * hash function before the remainder is taken.
4654 static inline unsigned long wait_table_bits(unsigned long size
)
4660 * Initially all pages are reserved - free ones are freed
4661 * up by free_all_bootmem() once the early boot process is
4662 * done. Non-atomic initialization, single-pass.
4664 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
4665 unsigned long start_pfn
, enum memmap_context context
)
4667 struct vmem_altmap
*altmap
= to_vmem_altmap(__pfn_to_phys(start_pfn
));
4668 unsigned long end_pfn
= start_pfn
+ size
;
4669 pg_data_t
*pgdat
= NODE_DATA(nid
);
4671 unsigned long nr_initialised
= 0;
4672 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4673 struct memblock_region
*r
= NULL
, *tmp
;
4676 if (highest_memmap_pfn
< end_pfn
- 1)
4677 highest_memmap_pfn
= end_pfn
- 1;
4680 * Honor reservation requested by the driver for this ZONE_DEVICE
4683 if (altmap
&& start_pfn
== altmap
->base_pfn
)
4684 start_pfn
+= altmap
->reserve
;
4686 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
4688 * There can be holes in boot-time mem_map[]s handed to this
4689 * function. They do not exist on hotplugged memory.
4691 if (context
!= MEMMAP_EARLY
)
4694 if (!early_pfn_valid(pfn
))
4696 if (!early_pfn_in_nid(pfn
, nid
))
4698 if (!update_defer_init(pgdat
, pfn
, end_pfn
, &nr_initialised
))
4701 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4703 * If not mirrored_kernelcore and ZONE_MOVABLE exists, range
4704 * from zone_movable_pfn[nid] to end of each node should be
4705 * ZONE_MOVABLE not ZONE_NORMAL. skip it.
4707 if (!mirrored_kernelcore
&& zone_movable_pfn
[nid
])
4708 if (zone
== ZONE_NORMAL
&& pfn
>= zone_movable_pfn
[nid
])
4712 * Check given memblock attribute by firmware which can affect
4713 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
4714 * mirrored, it's an overlapped memmap init. skip it.
4716 if (mirrored_kernelcore
&& zone
== ZONE_MOVABLE
) {
4717 if (!r
|| pfn
>= memblock_region_memory_end_pfn(r
)) {
4718 for_each_memblock(memory
, tmp
)
4719 if (pfn
< memblock_region_memory_end_pfn(tmp
))
4723 if (pfn
>= memblock_region_memory_base_pfn(r
) &&
4724 memblock_is_mirror(r
)) {
4725 /* already initialized as NORMAL */
4726 pfn
= memblock_region_memory_end_pfn(r
);
4734 * Mark the block movable so that blocks are reserved for
4735 * movable at startup. This will force kernel allocations
4736 * to reserve their blocks rather than leaking throughout
4737 * the address space during boot when many long-lived
4738 * kernel allocations are made.
4740 * bitmap is created for zone's valid pfn range. but memmap
4741 * can be created for invalid pages (for alignment)
4742 * check here not to call set_pageblock_migratetype() against
4745 if (!(pfn
& (pageblock_nr_pages
- 1))) {
4746 struct page
*page
= pfn_to_page(pfn
);
4748 __init_single_page(page
, pfn
, zone
, nid
);
4749 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4751 __init_single_pfn(pfn
, zone
, nid
);
4756 static void __meminit
zone_init_free_lists(struct zone
*zone
)
4758 unsigned int order
, t
;
4759 for_each_migratetype_order(order
, t
) {
4760 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
4761 zone
->free_area
[order
].nr_free
= 0;
4765 #ifndef __HAVE_ARCH_MEMMAP_INIT
4766 #define memmap_init(size, nid, zone, start_pfn) \
4767 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4770 static int zone_batchsize(struct zone
*zone
)
4776 * The per-cpu-pages pools are set to around 1000th of the
4777 * size of the zone. But no more than 1/2 of a meg.
4779 * OK, so we don't know how big the cache is. So guess.
4781 batch
= zone
->managed_pages
/ 1024;
4782 if (batch
* PAGE_SIZE
> 512 * 1024)
4783 batch
= (512 * 1024) / PAGE_SIZE
;
4784 batch
/= 4; /* We effectively *= 4 below */
4789 * Clamp the batch to a 2^n - 1 value. Having a power
4790 * of 2 value was found to be more likely to have
4791 * suboptimal cache aliasing properties in some cases.
4793 * For example if 2 tasks are alternately allocating
4794 * batches of pages, one task can end up with a lot
4795 * of pages of one half of the possible page colors
4796 * and the other with pages of the other colors.
4798 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
4803 /* The deferral and batching of frees should be suppressed under NOMMU
4806 * The problem is that NOMMU needs to be able to allocate large chunks
4807 * of contiguous memory as there's no hardware page translation to
4808 * assemble apparent contiguous memory from discontiguous pages.
4810 * Queueing large contiguous runs of pages for batching, however,
4811 * causes the pages to actually be freed in smaller chunks. As there
4812 * can be a significant delay between the individual batches being
4813 * recycled, this leads to the once large chunks of space being
4814 * fragmented and becoming unavailable for high-order allocations.
4821 * pcp->high and pcp->batch values are related and dependent on one another:
4822 * ->batch must never be higher then ->high.
4823 * The following function updates them in a safe manner without read side
4826 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4827 * those fields changing asynchronously (acording the the above rule).
4829 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4830 * outside of boot time (or some other assurance that no concurrent updaters
4833 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
4834 unsigned long batch
)
4836 /* start with a fail safe value for batch */
4840 /* Update high, then batch, in order */
4847 /* a companion to pageset_set_high() */
4848 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
4850 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
4853 static void pageset_init(struct per_cpu_pageset
*p
)
4855 struct per_cpu_pages
*pcp
;
4858 memset(p
, 0, sizeof(*p
));
4862 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
4863 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
4866 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
4869 pageset_set_batch(p
, batch
);
4873 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4874 * to the value high for the pageset p.
4876 static void pageset_set_high(struct per_cpu_pageset
*p
,
4879 unsigned long batch
= max(1UL, high
/ 4);
4880 if ((high
/ 4) > (PAGE_SHIFT
* 8))
4881 batch
= PAGE_SHIFT
* 8;
4883 pageset_update(&p
->pcp
, high
, batch
);
4886 static void pageset_set_high_and_batch(struct zone
*zone
,
4887 struct per_cpu_pageset
*pcp
)
4889 if (percpu_pagelist_fraction
)
4890 pageset_set_high(pcp
,
4891 (zone
->managed_pages
/
4892 percpu_pagelist_fraction
));
4894 pageset_set_batch(pcp
, zone_batchsize(zone
));
4897 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
4899 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
4902 pageset_set_high_and_batch(zone
, pcp
);
4905 static void __meminit
setup_zone_pageset(struct zone
*zone
)
4908 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
4909 for_each_possible_cpu(cpu
)
4910 zone_pageset_init(zone
, cpu
);
4914 * Allocate per cpu pagesets and initialize them.
4915 * Before this call only boot pagesets were available.
4917 void __init
setup_per_cpu_pageset(void)
4921 for_each_populated_zone(zone
)
4922 setup_zone_pageset(zone
);
4925 static noinline __init_refok
4926 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
4932 * The per-page waitqueue mechanism uses hashed waitqueues
4935 zone
->wait_table_hash_nr_entries
=
4936 wait_table_hash_nr_entries(zone_size_pages
);
4937 zone
->wait_table_bits
=
4938 wait_table_bits(zone
->wait_table_hash_nr_entries
);
4939 alloc_size
= zone
->wait_table_hash_nr_entries
4940 * sizeof(wait_queue_head_t
);
4942 if (!slab_is_available()) {
4943 zone
->wait_table
= (wait_queue_head_t
*)
4944 memblock_virt_alloc_node_nopanic(
4945 alloc_size
, zone
->zone_pgdat
->node_id
);
4948 * This case means that a zone whose size was 0 gets new memory
4949 * via memory hot-add.
4950 * But it may be the case that a new node was hot-added. In
4951 * this case vmalloc() will not be able to use this new node's
4952 * memory - this wait_table must be initialized to use this new
4953 * node itself as well.
4954 * To use this new node's memory, further consideration will be
4957 zone
->wait_table
= vmalloc(alloc_size
);
4959 if (!zone
->wait_table
)
4962 for (i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
4963 init_waitqueue_head(zone
->wait_table
+ i
);
4968 static __meminit
void zone_pcp_init(struct zone
*zone
)
4971 * per cpu subsystem is not up at this point. The following code
4972 * relies on the ability of the linker to provide the
4973 * offset of a (static) per cpu variable into the per cpu area.
4975 zone
->pageset
= &boot_pageset
;
4977 if (populated_zone(zone
))
4978 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
4979 zone
->name
, zone
->present_pages
,
4980 zone_batchsize(zone
));
4983 int __meminit
init_currently_empty_zone(struct zone
*zone
,
4984 unsigned long zone_start_pfn
,
4987 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
4989 ret
= zone_wait_table_init(zone
, size
);
4992 pgdat
->nr_zones
= zone_idx(zone
) + 1;
4994 zone
->zone_start_pfn
= zone_start_pfn
;
4996 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
4997 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4999 (unsigned long)zone_idx(zone
),
5000 zone_start_pfn
, (zone_start_pfn
+ size
));
5002 zone_init_free_lists(zone
);
5007 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5008 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
5011 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
5013 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
5014 struct mminit_pfnnid_cache
*state
)
5016 unsigned long start_pfn
, end_pfn
;
5019 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
5020 return state
->last_nid
;
5022 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
5024 state
->last_start
= start_pfn
;
5025 state
->last_end
= end_pfn
;
5026 state
->last_nid
= nid
;
5031 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5034 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5035 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5036 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5038 * If an architecture guarantees that all ranges registered contain no holes
5039 * and may be freed, this this function may be used instead of calling
5040 * memblock_free_early_nid() manually.
5042 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
5044 unsigned long start_pfn
, end_pfn
;
5047 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
5048 start_pfn
= min(start_pfn
, max_low_pfn
);
5049 end_pfn
= min(end_pfn
, max_low_pfn
);
5051 if (start_pfn
< end_pfn
)
5052 memblock_free_early_nid(PFN_PHYS(start_pfn
),
5053 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
5059 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5060 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5062 * If an architecture guarantees that all ranges registered contain no holes and may
5063 * be freed, this function may be used instead of calling memory_present() manually.
5065 void __init
sparse_memory_present_with_active_regions(int nid
)
5067 unsigned long start_pfn
, end_pfn
;
5070 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
5071 memory_present(this_nid
, start_pfn
, end_pfn
);
5075 * get_pfn_range_for_nid - Return the start and end page frames for a node
5076 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5077 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5078 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5080 * It returns the start and end page frame of a node based on information
5081 * provided by memblock_set_node(). If called for a node
5082 * with no available memory, a warning is printed and the start and end
5085 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
5086 unsigned long *start_pfn
, unsigned long *end_pfn
)
5088 unsigned long this_start_pfn
, this_end_pfn
;
5094 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
5095 *start_pfn
= min(*start_pfn
, this_start_pfn
);
5096 *end_pfn
= max(*end_pfn
, this_end_pfn
);
5099 if (*start_pfn
== -1UL)
5104 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5105 * assumption is made that zones within a node are ordered in monotonic
5106 * increasing memory addresses so that the "highest" populated zone is used
5108 static void __init
find_usable_zone_for_movable(void)
5111 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
5112 if (zone_index
== ZONE_MOVABLE
)
5115 if (arch_zone_highest_possible_pfn
[zone_index
] >
5116 arch_zone_lowest_possible_pfn
[zone_index
])
5120 VM_BUG_ON(zone_index
== -1);
5121 movable_zone
= zone_index
;
5125 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5126 * because it is sized independent of architecture. Unlike the other zones,
5127 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5128 * in each node depending on the size of each node and how evenly kernelcore
5129 * is distributed. This helper function adjusts the zone ranges
5130 * provided by the architecture for a given node by using the end of the
5131 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5132 * zones within a node are in order of monotonic increases memory addresses
5134 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
5135 unsigned long zone_type
,
5136 unsigned long node_start_pfn
,
5137 unsigned long node_end_pfn
,
5138 unsigned long *zone_start_pfn
,
5139 unsigned long *zone_end_pfn
)
5141 /* Only adjust if ZONE_MOVABLE is on this node */
5142 if (zone_movable_pfn
[nid
]) {
5143 /* Size ZONE_MOVABLE */
5144 if (zone_type
== ZONE_MOVABLE
) {
5145 *zone_start_pfn
= zone_movable_pfn
[nid
];
5146 *zone_end_pfn
= min(node_end_pfn
,
5147 arch_zone_highest_possible_pfn
[movable_zone
]);
5149 /* Check if this whole range is within ZONE_MOVABLE */
5150 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
5151 *zone_start_pfn
= *zone_end_pfn
;
5156 * Return the number of pages a zone spans in a node, including holes
5157 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5159 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5160 unsigned long zone_type
,
5161 unsigned long node_start_pfn
,
5162 unsigned long node_end_pfn
,
5163 unsigned long *zone_start_pfn
,
5164 unsigned long *zone_end_pfn
,
5165 unsigned long *ignored
)
5167 /* When hotadd a new node from cpu_up(), the node should be empty */
5168 if (!node_start_pfn
&& !node_end_pfn
)
5171 /* Get the start and end of the zone */
5172 *zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
5173 *zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
5174 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5175 node_start_pfn
, node_end_pfn
,
5176 zone_start_pfn
, zone_end_pfn
);
5178 /* Check that this node has pages within the zone's required range */
5179 if (*zone_end_pfn
< node_start_pfn
|| *zone_start_pfn
> node_end_pfn
)
5182 /* Move the zone boundaries inside the node if necessary */
5183 *zone_end_pfn
= min(*zone_end_pfn
, node_end_pfn
);
5184 *zone_start_pfn
= max(*zone_start_pfn
, node_start_pfn
);
5186 /* Return the spanned pages */
5187 return *zone_end_pfn
- *zone_start_pfn
;
5191 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5192 * then all holes in the requested range will be accounted for.
5194 unsigned long __meminit
__absent_pages_in_range(int nid
,
5195 unsigned long range_start_pfn
,
5196 unsigned long range_end_pfn
)
5198 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
5199 unsigned long start_pfn
, end_pfn
;
5202 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5203 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
5204 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
5205 nr_absent
-= end_pfn
- start_pfn
;
5211 * absent_pages_in_range - Return number of page frames in holes within a range
5212 * @start_pfn: The start PFN to start searching for holes
5213 * @end_pfn: The end PFN to stop searching for holes
5215 * It returns the number of pages frames in memory holes within a range.
5217 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
5218 unsigned long end_pfn
)
5220 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
5223 /* Return the number of page frames in holes in a zone on a node */
5224 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5225 unsigned long zone_type
,
5226 unsigned long node_start_pfn
,
5227 unsigned long node_end_pfn
,
5228 unsigned long *ignored
)
5230 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
5231 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
5232 unsigned long zone_start_pfn
, zone_end_pfn
;
5233 unsigned long nr_absent
;
5235 /* When hotadd a new node from cpu_up(), the node should be empty */
5236 if (!node_start_pfn
&& !node_end_pfn
)
5239 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
5240 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
5242 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5243 node_start_pfn
, node_end_pfn
,
5244 &zone_start_pfn
, &zone_end_pfn
);
5245 nr_absent
= __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
5248 * ZONE_MOVABLE handling.
5249 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5252 if (zone_movable_pfn
[nid
]) {
5253 if (mirrored_kernelcore
) {
5254 unsigned long start_pfn
, end_pfn
;
5255 struct memblock_region
*r
;
5257 for_each_memblock(memory
, r
) {
5258 start_pfn
= clamp(memblock_region_memory_base_pfn(r
),
5259 zone_start_pfn
, zone_end_pfn
);
5260 end_pfn
= clamp(memblock_region_memory_end_pfn(r
),
5261 zone_start_pfn
, zone_end_pfn
);
5263 if (zone_type
== ZONE_MOVABLE
&&
5264 memblock_is_mirror(r
))
5265 nr_absent
+= end_pfn
- start_pfn
;
5267 if (zone_type
== ZONE_NORMAL
&&
5268 !memblock_is_mirror(r
))
5269 nr_absent
+= end_pfn
- start_pfn
;
5272 if (zone_type
== ZONE_NORMAL
)
5273 nr_absent
+= node_end_pfn
- zone_movable_pfn
[nid
];
5280 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5281 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5282 unsigned long zone_type
,
5283 unsigned long node_start_pfn
,
5284 unsigned long node_end_pfn
,
5285 unsigned long *zone_start_pfn
,
5286 unsigned long *zone_end_pfn
,
5287 unsigned long *zones_size
)
5291 *zone_start_pfn
= node_start_pfn
;
5292 for (zone
= 0; zone
< zone_type
; zone
++)
5293 *zone_start_pfn
+= zones_size
[zone
];
5295 *zone_end_pfn
= *zone_start_pfn
+ zones_size
[zone_type
];
5297 return zones_size
[zone_type
];
5300 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5301 unsigned long zone_type
,
5302 unsigned long node_start_pfn
,
5303 unsigned long node_end_pfn
,
5304 unsigned long *zholes_size
)
5309 return zholes_size
[zone_type
];
5312 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5314 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
5315 unsigned long node_start_pfn
,
5316 unsigned long node_end_pfn
,
5317 unsigned long *zones_size
,
5318 unsigned long *zholes_size
)
5320 unsigned long realtotalpages
= 0, totalpages
= 0;
5323 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5324 struct zone
*zone
= pgdat
->node_zones
+ i
;
5325 unsigned long zone_start_pfn
, zone_end_pfn
;
5326 unsigned long size
, real_size
;
5328 size
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
5334 real_size
= size
- zone_absent_pages_in_node(pgdat
->node_id
, i
,
5335 node_start_pfn
, node_end_pfn
,
5338 zone
->zone_start_pfn
= zone_start_pfn
;
5340 zone
->zone_start_pfn
= 0;
5341 zone
->spanned_pages
= size
;
5342 zone
->present_pages
= real_size
;
5345 realtotalpages
+= real_size
;
5348 pgdat
->node_spanned_pages
= totalpages
;
5349 pgdat
->node_present_pages
= realtotalpages
;
5350 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
5354 #ifndef CONFIG_SPARSEMEM
5356 * Calculate the size of the zone->blockflags rounded to an unsigned long
5357 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5358 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5359 * round what is now in bits to nearest long in bits, then return it in
5362 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
5364 unsigned long usemapsize
;
5366 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
5367 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
5368 usemapsize
= usemapsize
>> pageblock_order
;
5369 usemapsize
*= NR_PAGEBLOCK_BITS
;
5370 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
5372 return usemapsize
/ 8;
5375 static void __init
setup_usemap(struct pglist_data
*pgdat
,
5377 unsigned long zone_start_pfn
,
5378 unsigned long zonesize
)
5380 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
5381 zone
->pageblock_flags
= NULL
;
5383 zone
->pageblock_flags
=
5384 memblock_virt_alloc_node_nopanic(usemapsize
,
5388 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
5389 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
5390 #endif /* CONFIG_SPARSEMEM */
5392 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5394 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5395 void __paginginit
set_pageblock_order(void)
5399 /* Check that pageblock_nr_pages has not already been setup */
5400 if (pageblock_order
)
5403 if (HPAGE_SHIFT
> PAGE_SHIFT
)
5404 order
= HUGETLB_PAGE_ORDER
;
5406 order
= MAX_ORDER
- 1;
5409 * Assume the largest contiguous order of interest is a huge page.
5410 * This value may be variable depending on boot parameters on IA64 and
5413 pageblock_order
= order
;
5415 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5418 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5419 * is unused as pageblock_order is set at compile-time. See
5420 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5423 void __paginginit
set_pageblock_order(void)
5427 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5429 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
5430 unsigned long present_pages
)
5432 unsigned long pages
= spanned_pages
;
5435 * Provide a more accurate estimation if there are holes within
5436 * the zone and SPARSEMEM is in use. If there are holes within the
5437 * zone, each populated memory region may cost us one or two extra
5438 * memmap pages due to alignment because memmap pages for each
5439 * populated regions may not naturally algined on page boundary.
5440 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5442 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
5443 IS_ENABLED(CONFIG_SPARSEMEM
))
5444 pages
= present_pages
;
5446 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
5450 * Set up the zone data structures:
5451 * - mark all pages reserved
5452 * - mark all memory queues empty
5453 * - clear the memory bitmaps
5455 * NOTE: pgdat should get zeroed by caller.
5457 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
)
5460 int nid
= pgdat
->node_id
;
5463 pgdat_resize_init(pgdat
);
5464 #ifdef CONFIG_NUMA_BALANCING
5465 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
5466 pgdat
->numabalancing_migrate_nr_pages
= 0;
5467 pgdat
->numabalancing_migrate_next_window
= jiffies
;
5469 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5470 spin_lock_init(&pgdat
->split_queue_lock
);
5471 INIT_LIST_HEAD(&pgdat
->split_queue
);
5472 pgdat
->split_queue_len
= 0;
5474 init_waitqueue_head(&pgdat
->kswapd_wait
);
5475 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
5476 #ifdef CONFIG_COMPACTION
5477 init_waitqueue_head(&pgdat
->kcompactd_wait
);
5479 pgdat_page_ext_init(pgdat
);
5481 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5482 struct zone
*zone
= pgdat
->node_zones
+ j
;
5483 unsigned long size
, realsize
, freesize
, memmap_pages
;
5484 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
5486 size
= zone
->spanned_pages
;
5487 realsize
= freesize
= zone
->present_pages
;
5490 * Adjust freesize so that it accounts for how much memory
5491 * is used by this zone for memmap. This affects the watermark
5492 * and per-cpu initialisations
5494 memmap_pages
= calc_memmap_size(size
, realsize
);
5495 if (!is_highmem_idx(j
)) {
5496 if (freesize
>= memmap_pages
) {
5497 freesize
-= memmap_pages
;
5500 " %s zone: %lu pages used for memmap\n",
5501 zone_names
[j
], memmap_pages
);
5503 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
5504 zone_names
[j
], memmap_pages
, freesize
);
5507 /* Account for reserved pages */
5508 if (j
== 0 && freesize
> dma_reserve
) {
5509 freesize
-= dma_reserve
;
5510 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
5511 zone_names
[0], dma_reserve
);
5514 if (!is_highmem_idx(j
))
5515 nr_kernel_pages
+= freesize
;
5516 /* Charge for highmem memmap if there are enough kernel pages */
5517 else if (nr_kernel_pages
> memmap_pages
* 2)
5518 nr_kernel_pages
-= memmap_pages
;
5519 nr_all_pages
+= freesize
;
5522 * Set an approximate value for lowmem here, it will be adjusted
5523 * when the bootmem allocator frees pages into the buddy system.
5524 * And all highmem pages will be managed by the buddy system.
5526 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
5529 zone
->min_unmapped_pages
= (freesize
*sysctl_min_unmapped_ratio
)
5531 zone
->min_slab_pages
= (freesize
* sysctl_min_slab_ratio
) / 100;
5533 zone
->name
= zone_names
[j
];
5534 spin_lock_init(&zone
->lock
);
5535 spin_lock_init(&zone
->lru_lock
);
5536 zone_seqlock_init(zone
);
5537 zone
->zone_pgdat
= pgdat
;
5538 zone_pcp_init(zone
);
5540 /* For bootup, initialized properly in watermark setup */
5541 mod_zone_page_state(zone
, NR_ALLOC_BATCH
, zone
->managed_pages
);
5543 lruvec_init(&zone
->lruvec
);
5547 set_pageblock_order();
5548 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
5549 ret
= init_currently_empty_zone(zone
, zone_start_pfn
, size
);
5551 memmap_init(size
, nid
, j
, zone_start_pfn
);
5555 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
5557 unsigned long __maybe_unused start
= 0;
5558 unsigned long __maybe_unused offset
= 0;
5560 /* Skip empty nodes */
5561 if (!pgdat
->node_spanned_pages
)
5564 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5565 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
5566 offset
= pgdat
->node_start_pfn
- start
;
5567 /* ia64 gets its own node_mem_map, before this, without bootmem */
5568 if (!pgdat
->node_mem_map
) {
5569 unsigned long size
, end
;
5573 * The zone's endpoints aren't required to be MAX_ORDER
5574 * aligned but the node_mem_map endpoints must be in order
5575 * for the buddy allocator to function correctly.
5577 end
= pgdat_end_pfn(pgdat
);
5578 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
5579 size
= (end
- start
) * sizeof(struct page
);
5580 map
= alloc_remap(pgdat
->node_id
, size
);
5582 map
= memblock_virt_alloc_node_nopanic(size
,
5584 pgdat
->node_mem_map
= map
+ offset
;
5586 #ifndef CONFIG_NEED_MULTIPLE_NODES
5588 * With no DISCONTIG, the global mem_map is just set as node 0's
5590 if (pgdat
== NODE_DATA(0)) {
5591 mem_map
= NODE_DATA(0)->node_mem_map
;
5592 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
5593 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
5595 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5598 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
5601 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
5602 unsigned long node_start_pfn
, unsigned long *zholes_size
)
5604 pg_data_t
*pgdat
= NODE_DATA(nid
);
5605 unsigned long start_pfn
= 0;
5606 unsigned long end_pfn
= 0;
5608 /* pg_data_t should be reset to zero when it's allocated */
5609 WARN_ON(pgdat
->nr_zones
|| pgdat
->classzone_idx
);
5611 reset_deferred_meminit(pgdat
);
5612 pgdat
->node_id
= nid
;
5613 pgdat
->node_start_pfn
= node_start_pfn
;
5614 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5615 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
5616 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
5617 (u64
)start_pfn
<< PAGE_SHIFT
,
5618 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
5620 start_pfn
= node_start_pfn
;
5622 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
5623 zones_size
, zholes_size
);
5625 alloc_node_mem_map(pgdat
);
5626 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5627 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
5628 nid
, (unsigned long)pgdat
,
5629 (unsigned long)pgdat
->node_mem_map
);
5632 free_area_init_core(pgdat
);
5635 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5637 #if MAX_NUMNODES > 1
5639 * Figure out the number of possible node ids.
5641 void __init
setup_nr_node_ids(void)
5643 unsigned int highest
;
5645 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
5646 nr_node_ids
= highest
+ 1;
5651 * node_map_pfn_alignment - determine the maximum internode alignment
5653 * This function should be called after node map is populated and sorted.
5654 * It calculates the maximum power of two alignment which can distinguish
5657 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5658 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5659 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5660 * shifted, 1GiB is enough and this function will indicate so.
5662 * This is used to test whether pfn -> nid mapping of the chosen memory
5663 * model has fine enough granularity to avoid incorrect mapping for the
5664 * populated node map.
5666 * Returns the determined alignment in pfn's. 0 if there is no alignment
5667 * requirement (single node).
5669 unsigned long __init
node_map_pfn_alignment(void)
5671 unsigned long accl_mask
= 0, last_end
= 0;
5672 unsigned long start
, end
, mask
;
5676 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
5677 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
5684 * Start with a mask granular enough to pin-point to the
5685 * start pfn and tick off bits one-by-one until it becomes
5686 * too coarse to separate the current node from the last.
5688 mask
= ~((1 << __ffs(start
)) - 1);
5689 while (mask
&& last_end
<= (start
& (mask
<< 1)))
5692 /* accumulate all internode masks */
5696 /* convert mask to number of pages */
5697 return ~accl_mask
+ 1;
5700 /* Find the lowest pfn for a node */
5701 static unsigned long __init
find_min_pfn_for_node(int nid
)
5703 unsigned long min_pfn
= ULONG_MAX
;
5704 unsigned long start_pfn
;
5707 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
5708 min_pfn
= min(min_pfn
, start_pfn
);
5710 if (min_pfn
== ULONG_MAX
) {
5711 pr_warn("Could not find start_pfn for node %d\n", nid
);
5719 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5721 * It returns the minimum PFN based on information provided via
5722 * memblock_set_node().
5724 unsigned long __init
find_min_pfn_with_active_regions(void)
5726 return find_min_pfn_for_node(MAX_NUMNODES
);
5730 * early_calculate_totalpages()
5731 * Sum pages in active regions for movable zone.
5732 * Populate N_MEMORY for calculating usable_nodes.
5734 static unsigned long __init
early_calculate_totalpages(void)
5736 unsigned long totalpages
= 0;
5737 unsigned long start_pfn
, end_pfn
;
5740 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
5741 unsigned long pages
= end_pfn
- start_pfn
;
5743 totalpages
+= pages
;
5745 node_set_state(nid
, N_MEMORY
);
5751 * Find the PFN the Movable zone begins in each node. Kernel memory
5752 * is spread evenly between nodes as long as the nodes have enough
5753 * memory. When they don't, some nodes will have more kernelcore than
5756 static void __init
find_zone_movable_pfns_for_nodes(void)
5759 unsigned long usable_startpfn
;
5760 unsigned long kernelcore_node
, kernelcore_remaining
;
5761 /* save the state before borrow the nodemask */
5762 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
5763 unsigned long totalpages
= early_calculate_totalpages();
5764 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
5765 struct memblock_region
*r
;
5767 /* Need to find movable_zone earlier when movable_node is specified. */
5768 find_usable_zone_for_movable();
5771 * If movable_node is specified, ignore kernelcore and movablecore
5774 if (movable_node_is_enabled()) {
5775 for_each_memblock(memory
, r
) {
5776 if (!memblock_is_hotpluggable(r
))
5781 usable_startpfn
= PFN_DOWN(r
->base
);
5782 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
5783 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
5791 * If kernelcore=mirror is specified, ignore movablecore option
5793 if (mirrored_kernelcore
) {
5794 bool mem_below_4gb_not_mirrored
= false;
5796 for_each_memblock(memory
, r
) {
5797 if (memblock_is_mirror(r
))
5802 usable_startpfn
= memblock_region_memory_base_pfn(r
);
5804 if (usable_startpfn
< 0x100000) {
5805 mem_below_4gb_not_mirrored
= true;
5809 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
5810 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
5814 if (mem_below_4gb_not_mirrored
)
5815 pr_warn("This configuration results in unmirrored kernel memory.");
5821 * If movablecore=nn[KMG] was specified, calculate what size of
5822 * kernelcore that corresponds so that memory usable for
5823 * any allocation type is evenly spread. If both kernelcore
5824 * and movablecore are specified, then the value of kernelcore
5825 * will be used for required_kernelcore if it's greater than
5826 * what movablecore would have allowed.
5828 if (required_movablecore
) {
5829 unsigned long corepages
;
5832 * Round-up so that ZONE_MOVABLE is at least as large as what
5833 * was requested by the user
5835 required_movablecore
=
5836 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
5837 required_movablecore
= min(totalpages
, required_movablecore
);
5838 corepages
= totalpages
- required_movablecore
;
5840 required_kernelcore
= max(required_kernelcore
, corepages
);
5844 * If kernelcore was not specified or kernelcore size is larger
5845 * than totalpages, there is no ZONE_MOVABLE.
5847 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
5850 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5851 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
5854 /* Spread kernelcore memory as evenly as possible throughout nodes */
5855 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5856 for_each_node_state(nid
, N_MEMORY
) {
5857 unsigned long start_pfn
, end_pfn
;
5860 * Recalculate kernelcore_node if the division per node
5861 * now exceeds what is necessary to satisfy the requested
5862 * amount of memory for the kernel
5864 if (required_kernelcore
< kernelcore_node
)
5865 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5868 * As the map is walked, we track how much memory is usable
5869 * by the kernel using kernelcore_remaining. When it is
5870 * 0, the rest of the node is usable by ZONE_MOVABLE
5872 kernelcore_remaining
= kernelcore_node
;
5874 /* Go through each range of PFNs within this node */
5875 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5876 unsigned long size_pages
;
5878 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
5879 if (start_pfn
>= end_pfn
)
5882 /* Account for what is only usable for kernelcore */
5883 if (start_pfn
< usable_startpfn
) {
5884 unsigned long kernel_pages
;
5885 kernel_pages
= min(end_pfn
, usable_startpfn
)
5888 kernelcore_remaining
-= min(kernel_pages
,
5889 kernelcore_remaining
);
5890 required_kernelcore
-= min(kernel_pages
,
5891 required_kernelcore
);
5893 /* Continue if range is now fully accounted */
5894 if (end_pfn
<= usable_startpfn
) {
5897 * Push zone_movable_pfn to the end so
5898 * that if we have to rebalance
5899 * kernelcore across nodes, we will
5900 * not double account here
5902 zone_movable_pfn
[nid
] = end_pfn
;
5905 start_pfn
= usable_startpfn
;
5909 * The usable PFN range for ZONE_MOVABLE is from
5910 * start_pfn->end_pfn. Calculate size_pages as the
5911 * number of pages used as kernelcore
5913 size_pages
= end_pfn
- start_pfn
;
5914 if (size_pages
> kernelcore_remaining
)
5915 size_pages
= kernelcore_remaining
;
5916 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
5919 * Some kernelcore has been met, update counts and
5920 * break if the kernelcore for this node has been
5923 required_kernelcore
-= min(required_kernelcore
,
5925 kernelcore_remaining
-= size_pages
;
5926 if (!kernelcore_remaining
)
5932 * If there is still required_kernelcore, we do another pass with one
5933 * less node in the count. This will push zone_movable_pfn[nid] further
5934 * along on the nodes that still have memory until kernelcore is
5938 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
5942 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5943 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
5944 zone_movable_pfn
[nid
] =
5945 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
5948 /* restore the node_state */
5949 node_states
[N_MEMORY
] = saved_node_state
;
5952 /* Any regular or high memory on that node ? */
5953 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
5955 enum zone_type zone_type
;
5957 if (N_MEMORY
== N_NORMAL_MEMORY
)
5960 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
5961 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
5962 if (populated_zone(zone
)) {
5963 node_set_state(nid
, N_HIGH_MEMORY
);
5964 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
5965 zone_type
<= ZONE_NORMAL
)
5966 node_set_state(nid
, N_NORMAL_MEMORY
);
5973 * free_area_init_nodes - Initialise all pg_data_t and zone data
5974 * @max_zone_pfn: an array of max PFNs for each zone
5976 * This will call free_area_init_node() for each active node in the system.
5977 * Using the page ranges provided by memblock_set_node(), the size of each
5978 * zone in each node and their holes is calculated. If the maximum PFN
5979 * between two adjacent zones match, it is assumed that the zone is empty.
5980 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5981 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5982 * starts where the previous one ended. For example, ZONE_DMA32 starts
5983 * at arch_max_dma_pfn.
5985 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
5987 unsigned long start_pfn
, end_pfn
;
5990 /* Record where the zone boundaries are */
5991 memset(arch_zone_lowest_possible_pfn
, 0,
5992 sizeof(arch_zone_lowest_possible_pfn
));
5993 memset(arch_zone_highest_possible_pfn
, 0,
5994 sizeof(arch_zone_highest_possible_pfn
));
5995 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
5996 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
5997 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
5998 if (i
== ZONE_MOVABLE
)
6000 arch_zone_lowest_possible_pfn
[i
] =
6001 arch_zone_highest_possible_pfn
[i
-1];
6002 arch_zone_highest_possible_pfn
[i
] =
6003 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
6005 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
6006 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
6008 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
6009 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
6010 find_zone_movable_pfns_for_nodes();
6012 /* Print out the zone ranges */
6013 pr_info("Zone ranges:\n");
6014 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6015 if (i
== ZONE_MOVABLE
)
6017 pr_info(" %-8s ", zone_names
[i
]);
6018 if (arch_zone_lowest_possible_pfn
[i
] ==
6019 arch_zone_highest_possible_pfn
[i
])
6022 pr_cont("[mem %#018Lx-%#018Lx]\n",
6023 (u64
)arch_zone_lowest_possible_pfn
[i
]
6025 ((u64
)arch_zone_highest_possible_pfn
[i
]
6026 << PAGE_SHIFT
) - 1);
6029 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
6030 pr_info("Movable zone start for each node\n");
6031 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
6032 if (zone_movable_pfn
[i
])
6033 pr_info(" Node %d: %#018Lx\n", i
,
6034 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
6037 /* Print out the early node map */
6038 pr_info("Early memory node ranges\n");
6039 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
6040 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
6041 (u64
)start_pfn
<< PAGE_SHIFT
,
6042 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
6044 /* Initialise every node */
6045 mminit_verify_pageflags_layout();
6046 setup_nr_node_ids();
6047 for_each_online_node(nid
) {
6048 pg_data_t
*pgdat
= NODE_DATA(nid
);
6049 free_area_init_node(nid
, NULL
,
6050 find_min_pfn_for_node(nid
), NULL
);
6052 /* Any memory on that node */
6053 if (pgdat
->node_present_pages
)
6054 node_set_state(nid
, N_MEMORY
);
6055 check_for_memory(pgdat
, nid
);
6059 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
6061 unsigned long long coremem
;
6065 coremem
= memparse(p
, &p
);
6066 *core
= coremem
>> PAGE_SHIFT
;
6068 /* Paranoid check that UL is enough for the coremem value */
6069 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
6075 * kernelcore=size sets the amount of memory for use for allocations that
6076 * cannot be reclaimed or migrated.
6078 static int __init
cmdline_parse_kernelcore(char *p
)
6080 /* parse kernelcore=mirror */
6081 if (parse_option_str(p
, "mirror")) {
6082 mirrored_kernelcore
= true;
6086 return cmdline_parse_core(p
, &required_kernelcore
);
6090 * movablecore=size sets the amount of memory for use for allocations that
6091 * can be reclaimed or migrated.
6093 static int __init
cmdline_parse_movablecore(char *p
)
6095 return cmdline_parse_core(p
, &required_movablecore
);
6098 early_param("kernelcore", cmdline_parse_kernelcore
);
6099 early_param("movablecore", cmdline_parse_movablecore
);
6101 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6103 void adjust_managed_page_count(struct page
*page
, long count
)
6105 spin_lock(&managed_page_count_lock
);
6106 page_zone(page
)->managed_pages
+= count
;
6107 totalram_pages
+= count
;
6108 #ifdef CONFIG_HIGHMEM
6109 if (PageHighMem(page
))
6110 totalhigh_pages
+= count
;
6112 spin_unlock(&managed_page_count_lock
);
6114 EXPORT_SYMBOL(adjust_managed_page_count
);
6116 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
6119 unsigned long pages
= 0;
6121 start
= (void *)PAGE_ALIGN((unsigned long)start
);
6122 end
= (void *)((unsigned long)end
& PAGE_MASK
);
6123 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
6124 if ((unsigned int)poison
<= 0xFF)
6125 memset(pos
, poison
, PAGE_SIZE
);
6126 free_reserved_page(virt_to_page(pos
));
6130 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
6131 s
, pages
<< (PAGE_SHIFT
- 10), start
, end
);
6135 EXPORT_SYMBOL(free_reserved_area
);
6137 #ifdef CONFIG_HIGHMEM
6138 void free_highmem_page(struct page
*page
)
6140 __free_reserved_page(page
);
6142 page_zone(page
)->managed_pages
++;
6148 void __init
mem_init_print_info(const char *str
)
6150 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
6151 unsigned long init_code_size
, init_data_size
;
6153 physpages
= get_num_physpages();
6154 codesize
= _etext
- _stext
;
6155 datasize
= _edata
- _sdata
;
6156 rosize
= __end_rodata
- __start_rodata
;
6157 bss_size
= __bss_stop
- __bss_start
;
6158 init_data_size
= __init_end
- __init_begin
;
6159 init_code_size
= _einittext
- _sinittext
;
6162 * Detect special cases and adjust section sizes accordingly:
6163 * 1) .init.* may be embedded into .data sections
6164 * 2) .init.text.* may be out of [__init_begin, __init_end],
6165 * please refer to arch/tile/kernel/vmlinux.lds.S.
6166 * 3) .rodata.* may be embedded into .text or .data sections.
6168 #define adj_init_size(start, end, size, pos, adj) \
6170 if (start <= pos && pos < end && size > adj) \
6174 adj_init_size(__init_begin
, __init_end
, init_data_size
,
6175 _sinittext
, init_code_size
);
6176 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
6177 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
6178 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
6179 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
6181 #undef adj_init_size
6183 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6184 #ifdef CONFIG_HIGHMEM
6188 nr_free_pages() << (PAGE_SHIFT
- 10),
6189 physpages
<< (PAGE_SHIFT
- 10),
6190 codesize
>> 10, datasize
>> 10, rosize
>> 10,
6191 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
6192 (physpages
- totalram_pages
- totalcma_pages
) << (PAGE_SHIFT
- 10),
6193 totalcma_pages
<< (PAGE_SHIFT
- 10),
6194 #ifdef CONFIG_HIGHMEM
6195 totalhigh_pages
<< (PAGE_SHIFT
- 10),
6197 str
? ", " : "", str
? str
: "");
6201 * set_dma_reserve - set the specified number of pages reserved in the first zone
6202 * @new_dma_reserve: The number of pages to mark reserved
6204 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6205 * In the DMA zone, a significant percentage may be consumed by kernel image
6206 * and other unfreeable allocations which can skew the watermarks badly. This
6207 * function may optionally be used to account for unfreeable pages in the
6208 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6209 * smaller per-cpu batchsize.
6211 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
6213 dma_reserve
= new_dma_reserve
;
6216 void __init
free_area_init(unsigned long *zones_size
)
6218 free_area_init_node(0, zones_size
,
6219 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
6222 static int page_alloc_cpu_notify(struct notifier_block
*self
,
6223 unsigned long action
, void *hcpu
)
6225 int cpu
= (unsigned long)hcpu
;
6227 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
6228 lru_add_drain_cpu(cpu
);
6232 * Spill the event counters of the dead processor
6233 * into the current processors event counters.
6234 * This artificially elevates the count of the current
6237 vm_events_fold_cpu(cpu
);
6240 * Zero the differential counters of the dead processor
6241 * so that the vm statistics are consistent.
6243 * This is only okay since the processor is dead and cannot
6244 * race with what we are doing.
6246 cpu_vm_stats_fold(cpu
);
6251 void __init
page_alloc_init(void)
6253 hotcpu_notifier(page_alloc_cpu_notify
, 0);
6257 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6258 * or min_free_kbytes changes.
6260 static void calculate_totalreserve_pages(void)
6262 struct pglist_data
*pgdat
;
6263 unsigned long reserve_pages
= 0;
6264 enum zone_type i
, j
;
6266 for_each_online_pgdat(pgdat
) {
6267 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6268 struct zone
*zone
= pgdat
->node_zones
+ i
;
6271 /* Find valid and maximum lowmem_reserve in the zone */
6272 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
6273 if (zone
->lowmem_reserve
[j
] > max
)
6274 max
= zone
->lowmem_reserve
[j
];
6277 /* we treat the high watermark as reserved pages. */
6278 max
+= high_wmark_pages(zone
);
6280 if (max
> zone
->managed_pages
)
6281 max
= zone
->managed_pages
;
6283 zone
->totalreserve_pages
= max
;
6285 reserve_pages
+= max
;
6288 totalreserve_pages
= reserve_pages
;
6292 * setup_per_zone_lowmem_reserve - called whenever
6293 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6294 * has a correct pages reserved value, so an adequate number of
6295 * pages are left in the zone after a successful __alloc_pages().
6297 static void setup_per_zone_lowmem_reserve(void)
6299 struct pglist_data
*pgdat
;
6300 enum zone_type j
, idx
;
6302 for_each_online_pgdat(pgdat
) {
6303 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6304 struct zone
*zone
= pgdat
->node_zones
+ j
;
6305 unsigned long managed_pages
= zone
->managed_pages
;
6307 zone
->lowmem_reserve
[j
] = 0;
6311 struct zone
*lower_zone
;
6315 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
6316 sysctl_lowmem_reserve_ratio
[idx
] = 1;
6318 lower_zone
= pgdat
->node_zones
+ idx
;
6319 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
6320 sysctl_lowmem_reserve_ratio
[idx
];
6321 managed_pages
+= lower_zone
->managed_pages
;
6326 /* update totalreserve_pages */
6327 calculate_totalreserve_pages();
6330 static void __setup_per_zone_wmarks(void)
6332 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
6333 unsigned long lowmem_pages
= 0;
6335 unsigned long flags
;
6337 /* Calculate total number of !ZONE_HIGHMEM pages */
6338 for_each_zone(zone
) {
6339 if (!is_highmem(zone
))
6340 lowmem_pages
+= zone
->managed_pages
;
6343 for_each_zone(zone
) {
6346 spin_lock_irqsave(&zone
->lock
, flags
);
6347 tmp
= (u64
)pages_min
* zone
->managed_pages
;
6348 do_div(tmp
, lowmem_pages
);
6349 if (is_highmem(zone
)) {
6351 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6352 * need highmem pages, so cap pages_min to a small
6355 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6356 * deltas control asynch page reclaim, and so should
6357 * not be capped for highmem.
6359 unsigned long min_pages
;
6361 min_pages
= zone
->managed_pages
/ 1024;
6362 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
6363 zone
->watermark
[WMARK_MIN
] = min_pages
;
6366 * If it's a lowmem zone, reserve a number of pages
6367 * proportionate to the zone's size.
6369 zone
->watermark
[WMARK_MIN
] = tmp
;
6373 * Set the kswapd watermarks distance according to the
6374 * scale factor in proportion to available memory, but
6375 * ensure a minimum size on small systems.
6377 tmp
= max_t(u64
, tmp
>> 2,
6378 mult_frac(zone
->managed_pages
,
6379 watermark_scale_factor
, 10000));
6381 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + tmp
;
6382 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + tmp
* 2;
6384 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
6385 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
6386 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
6388 spin_unlock_irqrestore(&zone
->lock
, flags
);
6391 /* update totalreserve_pages */
6392 calculate_totalreserve_pages();
6396 * setup_per_zone_wmarks - called when min_free_kbytes changes
6397 * or when memory is hot-{added|removed}
6399 * Ensures that the watermark[min,low,high] values for each zone are set
6400 * correctly with respect to min_free_kbytes.
6402 void setup_per_zone_wmarks(void)
6404 mutex_lock(&zonelists_mutex
);
6405 __setup_per_zone_wmarks();
6406 mutex_unlock(&zonelists_mutex
);
6410 * The inactive anon list should be small enough that the VM never has to
6411 * do too much work, but large enough that each inactive page has a chance
6412 * to be referenced again before it is swapped out.
6414 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
6415 * INACTIVE_ANON pages on this zone's LRU, maintained by the
6416 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
6417 * the anonymous pages are kept on the inactive list.
6420 * memory ratio inactive anon
6421 * -------------------------------------
6430 static void __meminit
calculate_zone_inactive_ratio(struct zone
*zone
)
6432 unsigned int gb
, ratio
;
6434 /* Zone size in gigabytes */
6435 gb
= zone
->managed_pages
>> (30 - PAGE_SHIFT
);
6437 ratio
= int_sqrt(10 * gb
);
6441 zone
->inactive_ratio
= ratio
;
6444 static void __meminit
setup_per_zone_inactive_ratio(void)
6449 calculate_zone_inactive_ratio(zone
);
6453 * Initialise min_free_kbytes.
6455 * For small machines we want it small (128k min). For large machines
6456 * we want it large (64MB max). But it is not linear, because network
6457 * bandwidth does not increase linearly with machine size. We use
6459 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6460 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6476 int __meminit
init_per_zone_wmark_min(void)
6478 unsigned long lowmem_kbytes
;
6479 int new_min_free_kbytes
;
6481 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
6482 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
6484 if (new_min_free_kbytes
> user_min_free_kbytes
) {
6485 min_free_kbytes
= new_min_free_kbytes
;
6486 if (min_free_kbytes
< 128)
6487 min_free_kbytes
= 128;
6488 if (min_free_kbytes
> 65536)
6489 min_free_kbytes
= 65536;
6491 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6492 new_min_free_kbytes
, user_min_free_kbytes
);
6494 setup_per_zone_wmarks();
6495 refresh_zone_stat_thresholds();
6496 setup_per_zone_lowmem_reserve();
6497 setup_per_zone_inactive_ratio();
6500 core_initcall(init_per_zone_wmark_min
)
6503 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6504 * that we can call two helper functions whenever min_free_kbytes
6507 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
6508 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6512 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6517 user_min_free_kbytes
= min_free_kbytes
;
6518 setup_per_zone_wmarks();
6523 int watermark_scale_factor_sysctl_handler(struct ctl_table
*table
, int write
,
6524 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6528 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6533 setup_per_zone_wmarks();
6539 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6540 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6545 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6550 zone
->min_unmapped_pages
= (zone
->managed_pages
*
6551 sysctl_min_unmapped_ratio
) / 100;
6555 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6556 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6561 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6566 zone
->min_slab_pages
= (zone
->managed_pages
*
6567 sysctl_min_slab_ratio
) / 100;
6573 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6574 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6575 * whenever sysctl_lowmem_reserve_ratio changes.
6577 * The reserve ratio obviously has absolutely no relation with the
6578 * minimum watermarks. The lowmem reserve ratio can only make sense
6579 * if in function of the boot time zone sizes.
6581 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6582 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6584 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6585 setup_per_zone_lowmem_reserve();
6590 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6591 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6592 * pagelist can have before it gets flushed back to buddy allocator.
6594 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
6595 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6598 int old_percpu_pagelist_fraction
;
6601 mutex_lock(&pcp_batch_high_lock
);
6602 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
6604 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6605 if (!write
|| ret
< 0)
6608 /* Sanity checking to avoid pcp imbalance */
6609 if (percpu_pagelist_fraction
&&
6610 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
6611 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
6617 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
6620 for_each_populated_zone(zone
) {
6623 for_each_possible_cpu(cpu
)
6624 pageset_set_high_and_batch(zone
,
6625 per_cpu_ptr(zone
->pageset
, cpu
));
6628 mutex_unlock(&pcp_batch_high_lock
);
6633 int hashdist
= HASHDIST_DEFAULT
;
6635 static int __init
set_hashdist(char *str
)
6639 hashdist
= simple_strtoul(str
, &str
, 0);
6642 __setup("hashdist=", set_hashdist
);
6646 * allocate a large system hash table from bootmem
6647 * - it is assumed that the hash table must contain an exact power-of-2
6648 * quantity of entries
6649 * - limit is the number of hash buckets, not the total allocation size
6651 void *__init
alloc_large_system_hash(const char *tablename
,
6652 unsigned long bucketsize
,
6653 unsigned long numentries
,
6656 unsigned int *_hash_shift
,
6657 unsigned int *_hash_mask
,
6658 unsigned long low_limit
,
6659 unsigned long high_limit
)
6661 unsigned long long max
= high_limit
;
6662 unsigned long log2qty
, size
;
6665 /* allow the kernel cmdline to have a say */
6667 /* round applicable memory size up to nearest megabyte */
6668 numentries
= nr_kernel_pages
;
6670 /* It isn't necessary when PAGE_SIZE >= 1MB */
6671 if (PAGE_SHIFT
< 20)
6672 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
6674 /* limit to 1 bucket per 2^scale bytes of low memory */
6675 if (scale
> PAGE_SHIFT
)
6676 numentries
>>= (scale
- PAGE_SHIFT
);
6678 numentries
<<= (PAGE_SHIFT
- scale
);
6680 /* Make sure we've got at least a 0-order allocation.. */
6681 if (unlikely(flags
& HASH_SMALL
)) {
6682 /* Makes no sense without HASH_EARLY */
6683 WARN_ON(!(flags
& HASH_EARLY
));
6684 if (!(numentries
>> *_hash_shift
)) {
6685 numentries
= 1UL << *_hash_shift
;
6686 BUG_ON(!numentries
);
6688 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
6689 numentries
= PAGE_SIZE
/ bucketsize
;
6691 numentries
= roundup_pow_of_two(numentries
);
6693 /* limit allocation size to 1/16 total memory by default */
6695 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
6696 do_div(max
, bucketsize
);
6698 max
= min(max
, 0x80000000ULL
);
6700 if (numentries
< low_limit
)
6701 numentries
= low_limit
;
6702 if (numentries
> max
)
6705 log2qty
= ilog2(numentries
);
6708 size
= bucketsize
<< log2qty
;
6709 if (flags
& HASH_EARLY
)
6710 table
= memblock_virt_alloc_nopanic(size
, 0);
6712 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
6715 * If bucketsize is not a power-of-two, we may free
6716 * some pages at the end of hash table which
6717 * alloc_pages_exact() automatically does
6719 if (get_order(size
) < MAX_ORDER
) {
6720 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
6721 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
6724 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
6727 panic("Failed to allocate %s hash table\n", tablename
);
6729 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
6730 tablename
, 1UL << log2qty
, ilog2(size
) - PAGE_SHIFT
, size
);
6733 *_hash_shift
= log2qty
;
6735 *_hash_mask
= (1 << log2qty
) - 1;
6740 /* Return a pointer to the bitmap storing bits affecting a block of pages */
6741 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
6744 #ifdef CONFIG_SPARSEMEM
6745 return __pfn_to_section(pfn
)->pageblock_flags
;
6747 return zone
->pageblock_flags
;
6748 #endif /* CONFIG_SPARSEMEM */
6751 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
6753 #ifdef CONFIG_SPARSEMEM
6754 pfn
&= (PAGES_PER_SECTION
-1);
6755 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6757 pfn
= pfn
- round_down(zone
->zone_start_pfn
, pageblock_nr_pages
);
6758 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6759 #endif /* CONFIG_SPARSEMEM */
6763 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
6764 * @page: The page within the block of interest
6765 * @pfn: The target page frame number
6766 * @end_bitidx: The last bit of interest to retrieve
6767 * @mask: mask of bits that the caller is interested in
6769 * Return: pageblock_bits flags
6771 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
6772 unsigned long end_bitidx
,
6776 unsigned long *bitmap
;
6777 unsigned long bitidx
, word_bitidx
;
6780 zone
= page_zone(page
);
6781 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6782 bitidx
= pfn_to_bitidx(zone
, pfn
);
6783 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6784 bitidx
&= (BITS_PER_LONG
-1);
6786 word
= bitmap
[word_bitidx
];
6787 bitidx
+= end_bitidx
;
6788 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
6792 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
6793 * @page: The page within the block of interest
6794 * @flags: The flags to set
6795 * @pfn: The target page frame number
6796 * @end_bitidx: The last bit of interest
6797 * @mask: mask of bits that the caller is interested in
6799 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
6801 unsigned long end_bitidx
,
6805 unsigned long *bitmap
;
6806 unsigned long bitidx
, word_bitidx
;
6807 unsigned long old_word
, word
;
6809 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
6811 zone
= page_zone(page
);
6812 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6813 bitidx
= pfn_to_bitidx(zone
, pfn
);
6814 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6815 bitidx
&= (BITS_PER_LONG
-1);
6817 VM_BUG_ON_PAGE(!zone_spans_pfn(zone
, pfn
), page
);
6819 bitidx
+= end_bitidx
;
6820 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
6821 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
6823 word
= READ_ONCE(bitmap
[word_bitidx
]);
6825 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
6826 if (word
== old_word
)
6833 * This function checks whether pageblock includes unmovable pages or not.
6834 * If @count is not zero, it is okay to include less @count unmovable pages
6836 * PageLRU check without isolation or lru_lock could race so that
6837 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6838 * expect this function should be exact.
6840 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
6841 bool skip_hwpoisoned_pages
)
6843 unsigned long pfn
, iter
, found
;
6847 * For avoiding noise data, lru_add_drain_all() should be called
6848 * If ZONE_MOVABLE, the zone never contains unmovable pages
6850 if (zone_idx(zone
) == ZONE_MOVABLE
)
6852 mt
= get_pageblock_migratetype(page
);
6853 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
6856 pfn
= page_to_pfn(page
);
6857 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
6858 unsigned long check
= pfn
+ iter
;
6860 if (!pfn_valid_within(check
))
6863 page
= pfn_to_page(check
);
6866 * Hugepages are not in LRU lists, but they're movable.
6867 * We need not scan over tail pages bacause we don't
6868 * handle each tail page individually in migration.
6870 if (PageHuge(page
)) {
6871 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
6876 * We can't use page_count without pin a page
6877 * because another CPU can free compound page.
6878 * This check already skips compound tails of THP
6879 * because their page->_refcount is zero at all time.
6881 if (!page_ref_count(page
)) {
6882 if (PageBuddy(page
))
6883 iter
+= (1 << page_order(page
)) - 1;
6888 * The HWPoisoned page may be not in buddy system, and
6889 * page_count() is not 0.
6891 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
6897 * If there are RECLAIMABLE pages, we need to check
6898 * it. But now, memory offline itself doesn't call
6899 * shrink_node_slabs() and it still to be fixed.
6902 * If the page is not RAM, page_count()should be 0.
6903 * we don't need more check. This is an _used_ not-movable page.
6905 * The problematic thing here is PG_reserved pages. PG_reserved
6906 * is set to both of a memory hole page and a _used_ kernel
6915 bool is_pageblock_removable_nolock(struct page
*page
)
6921 * We have to be careful here because we are iterating over memory
6922 * sections which are not zone aware so we might end up outside of
6923 * the zone but still within the section.
6924 * We have to take care about the node as well. If the node is offline
6925 * its NODE_DATA will be NULL - see page_zone.
6927 if (!node_online(page_to_nid(page
)))
6930 zone
= page_zone(page
);
6931 pfn
= page_to_pfn(page
);
6932 if (!zone_spans_pfn(zone
, pfn
))
6935 return !has_unmovable_pages(zone
, page
, 0, true);
6938 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
6940 static unsigned long pfn_max_align_down(unsigned long pfn
)
6942 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6943 pageblock_nr_pages
) - 1);
6946 static unsigned long pfn_max_align_up(unsigned long pfn
)
6948 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6949 pageblock_nr_pages
));
6952 /* [start, end) must belong to a single zone. */
6953 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
6954 unsigned long start
, unsigned long end
)
6956 /* This function is based on compact_zone() from compaction.c. */
6957 unsigned long nr_reclaimed
;
6958 unsigned long pfn
= start
;
6959 unsigned int tries
= 0;
6964 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
6965 if (fatal_signal_pending(current
)) {
6970 if (list_empty(&cc
->migratepages
)) {
6971 cc
->nr_migratepages
= 0;
6972 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
6978 } else if (++tries
== 5) {
6979 ret
= ret
< 0 ? ret
: -EBUSY
;
6983 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
6985 cc
->nr_migratepages
-= nr_reclaimed
;
6987 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
6988 NULL
, 0, cc
->mode
, MR_CMA
);
6991 putback_movable_pages(&cc
->migratepages
);
6998 * alloc_contig_range() -- tries to allocate given range of pages
6999 * @start: start PFN to allocate
7000 * @end: one-past-the-last PFN to allocate
7001 * @migratetype: migratetype of the underlaying pageblocks (either
7002 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
7003 * in range must have the same migratetype and it must
7004 * be either of the two.
7006 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
7007 * aligned, however it's the caller's responsibility to guarantee that
7008 * we are the only thread that changes migrate type of pageblocks the
7011 * The PFN range must belong to a single zone.
7013 * Returns zero on success or negative error code. On success all
7014 * pages which PFN is in [start, end) are allocated for the caller and
7015 * need to be freed with free_contig_range().
7017 int alloc_contig_range(unsigned long start
, unsigned long end
,
7018 unsigned migratetype
)
7020 unsigned long outer_start
, outer_end
;
7024 struct compact_control cc
= {
7025 .nr_migratepages
= 0,
7027 .zone
= page_zone(pfn_to_page(start
)),
7028 .mode
= MIGRATE_SYNC
,
7029 .ignore_skip_hint
= true,
7031 INIT_LIST_HEAD(&cc
.migratepages
);
7034 * What we do here is we mark all pageblocks in range as
7035 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7036 * have different sizes, and due to the way page allocator
7037 * work, we align the range to biggest of the two pages so
7038 * that page allocator won't try to merge buddies from
7039 * different pageblocks and change MIGRATE_ISOLATE to some
7040 * other migration type.
7042 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7043 * migrate the pages from an unaligned range (ie. pages that
7044 * we are interested in). This will put all the pages in
7045 * range back to page allocator as MIGRATE_ISOLATE.
7047 * When this is done, we take the pages in range from page
7048 * allocator removing them from the buddy system. This way
7049 * page allocator will never consider using them.
7051 * This lets us mark the pageblocks back as
7052 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7053 * aligned range but not in the unaligned, original range are
7054 * put back to page allocator so that buddy can use them.
7057 ret
= start_isolate_page_range(pfn_max_align_down(start
),
7058 pfn_max_align_up(end
), migratetype
,
7064 * In case of -EBUSY, we'd like to know which page causes problem.
7065 * So, just fall through. We will check it in test_pages_isolated().
7067 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
7068 if (ret
&& ret
!= -EBUSY
)
7072 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7073 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7074 * more, all pages in [start, end) are free in page allocator.
7075 * What we are going to do is to allocate all pages from
7076 * [start, end) (that is remove them from page allocator).
7078 * The only problem is that pages at the beginning and at the
7079 * end of interesting range may be not aligned with pages that
7080 * page allocator holds, ie. they can be part of higher order
7081 * pages. Because of this, we reserve the bigger range and
7082 * once this is done free the pages we are not interested in.
7084 * We don't have to hold zone->lock here because the pages are
7085 * isolated thus they won't get removed from buddy.
7088 lru_add_drain_all();
7089 drain_all_pages(cc
.zone
);
7092 outer_start
= start
;
7093 while (!PageBuddy(pfn_to_page(outer_start
))) {
7094 if (++order
>= MAX_ORDER
) {
7095 outer_start
= start
;
7098 outer_start
&= ~0UL << order
;
7101 if (outer_start
!= start
) {
7102 order
= page_order(pfn_to_page(outer_start
));
7105 * outer_start page could be small order buddy page and
7106 * it doesn't include start page. Adjust outer_start
7107 * in this case to report failed page properly
7108 * on tracepoint in test_pages_isolated()
7110 if (outer_start
+ (1UL << order
) <= start
)
7111 outer_start
= start
;
7114 /* Make sure the range is really isolated. */
7115 if (test_pages_isolated(outer_start
, end
, false)) {
7116 pr_info("%s: [%lx, %lx) PFNs busy\n",
7117 __func__
, outer_start
, end
);
7122 /* Grab isolated pages from freelists. */
7123 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
7129 /* Free head and tail (if any) */
7130 if (start
!= outer_start
)
7131 free_contig_range(outer_start
, start
- outer_start
);
7132 if (end
!= outer_end
)
7133 free_contig_range(end
, outer_end
- end
);
7136 undo_isolate_page_range(pfn_max_align_down(start
),
7137 pfn_max_align_up(end
), migratetype
);
7141 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
7143 unsigned int count
= 0;
7145 for (; nr_pages
--; pfn
++) {
7146 struct page
*page
= pfn_to_page(pfn
);
7148 count
+= page_count(page
) != 1;
7151 WARN(count
!= 0, "%d pages are still in use!\n", count
);
7155 #ifdef CONFIG_MEMORY_HOTPLUG
7157 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7158 * page high values need to be recalulated.
7160 void __meminit
zone_pcp_update(struct zone
*zone
)
7163 mutex_lock(&pcp_batch_high_lock
);
7164 for_each_possible_cpu(cpu
)
7165 pageset_set_high_and_batch(zone
,
7166 per_cpu_ptr(zone
->pageset
, cpu
));
7167 mutex_unlock(&pcp_batch_high_lock
);
7171 void zone_pcp_reset(struct zone
*zone
)
7173 unsigned long flags
;
7175 struct per_cpu_pageset
*pset
;
7177 /* avoid races with drain_pages() */
7178 local_irq_save(flags
);
7179 if (zone
->pageset
!= &boot_pageset
) {
7180 for_each_online_cpu(cpu
) {
7181 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
7182 drain_zonestat(zone
, pset
);
7184 free_percpu(zone
->pageset
);
7185 zone
->pageset
= &boot_pageset
;
7187 local_irq_restore(flags
);
7190 #ifdef CONFIG_MEMORY_HOTREMOVE
7192 * All pages in the range must be in a single zone and isolated
7193 * before calling this.
7196 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
7200 unsigned int order
, i
;
7202 unsigned long flags
;
7203 /* find the first valid pfn */
7204 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
7209 zone
= page_zone(pfn_to_page(pfn
));
7210 spin_lock_irqsave(&zone
->lock
, flags
);
7212 while (pfn
< end_pfn
) {
7213 if (!pfn_valid(pfn
)) {
7217 page
= pfn_to_page(pfn
);
7219 * The HWPoisoned page may be not in buddy system, and
7220 * page_count() is not 0.
7222 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
7224 SetPageReserved(page
);
7228 BUG_ON(page_count(page
));
7229 BUG_ON(!PageBuddy(page
));
7230 order
= page_order(page
);
7231 #ifdef CONFIG_DEBUG_VM
7232 pr_info("remove from free list %lx %d %lx\n",
7233 pfn
, 1 << order
, end_pfn
);
7235 list_del(&page
->lru
);
7236 rmv_page_order(page
);
7237 zone
->free_area
[order
].nr_free
--;
7238 for (i
= 0; i
< (1 << order
); i
++)
7239 SetPageReserved((page
+i
));
7240 pfn
+= (1 << order
);
7242 spin_unlock_irqrestore(&zone
->lock
, flags
);
7246 bool is_free_buddy_page(struct page
*page
)
7248 struct zone
*zone
= page_zone(page
);
7249 unsigned long pfn
= page_to_pfn(page
);
7250 unsigned long flags
;
7253 spin_lock_irqsave(&zone
->lock
, flags
);
7254 for (order
= 0; order
< MAX_ORDER
; order
++) {
7255 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
7257 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
7260 spin_unlock_irqrestore(&zone
->lock
, flags
);
7262 return order
< MAX_ORDER
;