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
= MAX_ORDER
;
697 VM_BUG_ON(!zone_is_initialized(zone
));
698 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
700 VM_BUG_ON(migratetype
== -1);
701 if (is_migrate_isolate(migratetype
)) {
703 * We restrict max order of merging to prevent merge
704 * between freepages on isolate pageblock and normal
705 * pageblock. Without this, pageblock isolation
706 * could cause incorrect freepage accounting.
708 max_order
= min_t(unsigned int, MAX_ORDER
, pageblock_order
+ 1);
710 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
713 page_idx
= pfn
& ((1 << max_order
) - 1);
715 VM_BUG_ON_PAGE(page_idx
& ((1 << order
) - 1), page
);
716 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
718 while (order
< max_order
- 1) {
719 buddy_idx
= __find_buddy_index(page_idx
, order
);
720 buddy
= page
+ (buddy_idx
- page_idx
);
721 if (!page_is_buddy(page
, buddy
, order
))
724 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
725 * merge with it and move up one order.
727 if (page_is_guard(buddy
)) {
728 clear_page_guard(zone
, buddy
, order
, migratetype
);
730 list_del(&buddy
->lru
);
731 zone
->free_area
[order
].nr_free
--;
732 rmv_page_order(buddy
);
734 combined_idx
= buddy_idx
& page_idx
;
735 page
= page
+ (combined_idx
- page_idx
);
736 page_idx
= combined_idx
;
739 set_page_order(page
, order
);
742 * If this is not the largest possible page, check if the buddy
743 * of the next-highest order is free. If it is, it's possible
744 * that pages are being freed that will coalesce soon. In case,
745 * that is happening, add the free page to the tail of the list
746 * so it's less likely to be used soon and more likely to be merged
747 * as a higher order page
749 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
750 struct page
*higher_page
, *higher_buddy
;
751 combined_idx
= buddy_idx
& page_idx
;
752 higher_page
= page
+ (combined_idx
- page_idx
);
753 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
754 higher_buddy
= higher_page
+ (buddy_idx
- combined_idx
);
755 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
756 list_add_tail(&page
->lru
,
757 &zone
->free_area
[order
].free_list
[migratetype
]);
762 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
764 zone
->free_area
[order
].nr_free
++;
767 static inline int free_pages_check(struct page
*page
)
769 const char *bad_reason
= NULL
;
770 unsigned long bad_flags
= 0;
772 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
773 bad_reason
= "nonzero mapcount";
774 if (unlikely(page
->mapping
!= NULL
))
775 bad_reason
= "non-NULL mapping";
776 if (unlikely(page_ref_count(page
) != 0))
777 bad_reason
= "nonzero _count";
778 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
779 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
780 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
783 if (unlikely(page
->mem_cgroup
))
784 bad_reason
= "page still charged to cgroup";
786 if (unlikely(bad_reason
)) {
787 bad_page(page
, bad_reason
, bad_flags
);
790 page_cpupid_reset_last(page
);
791 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
792 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
797 * Frees a number of pages from the PCP lists
798 * Assumes all pages on list are in same zone, and of same order.
799 * count is the number of pages to free.
801 * If the zone was previously in an "all pages pinned" state then look to
802 * see if this freeing clears that state.
804 * And clear the zone's pages_scanned counter, to hold off the "all pages are
805 * pinned" detection logic.
807 static void free_pcppages_bulk(struct zone
*zone
, int count
,
808 struct per_cpu_pages
*pcp
)
813 unsigned long nr_scanned
;
815 spin_lock(&zone
->lock
);
816 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
818 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
822 struct list_head
*list
;
825 * Remove pages from lists in a round-robin fashion. A
826 * batch_free count is maintained that is incremented when an
827 * empty list is encountered. This is so more pages are freed
828 * off fuller lists instead of spinning excessively around empty
833 if (++migratetype
== MIGRATE_PCPTYPES
)
835 list
= &pcp
->lists
[migratetype
];
836 } while (list_empty(list
));
838 /* This is the only non-empty list. Free them all. */
839 if (batch_free
== MIGRATE_PCPTYPES
)
840 batch_free
= to_free
;
843 int mt
; /* migratetype of the to-be-freed page */
845 page
= list_last_entry(list
, struct page
, lru
);
846 /* must delete as __free_one_page list manipulates */
847 list_del(&page
->lru
);
849 mt
= get_pcppage_migratetype(page
);
850 /* MIGRATE_ISOLATE page should not go to pcplists */
851 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
852 /* Pageblock could have been isolated meanwhile */
853 if (unlikely(has_isolate_pageblock(zone
)))
854 mt
= get_pageblock_migratetype(page
);
856 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
);
857 trace_mm_page_pcpu_drain(page
, 0, mt
);
858 } while (--to_free
&& --batch_free
&& !list_empty(list
));
860 spin_unlock(&zone
->lock
);
863 static void free_one_page(struct zone
*zone
,
864 struct page
*page
, unsigned long pfn
,
868 unsigned long nr_scanned
;
869 spin_lock(&zone
->lock
);
870 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
872 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
874 if (unlikely(has_isolate_pageblock(zone
) ||
875 is_migrate_isolate(migratetype
))) {
876 migratetype
= get_pfnblock_migratetype(page
, pfn
);
878 __free_one_page(page
, pfn
, zone
, order
, migratetype
);
879 spin_unlock(&zone
->lock
);
882 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
887 * We rely page->lru.next never has bit 0 set, unless the page
888 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
890 BUILD_BUG_ON((unsigned long)LIST_POISON1
& 1);
892 if (!IS_ENABLED(CONFIG_DEBUG_VM
)) {
896 switch (page
- head_page
) {
898 /* the first tail page: ->mapping is compound_mapcount() */
899 if (unlikely(compound_mapcount(page
))) {
900 bad_page(page
, "nonzero compound_mapcount", 0);
906 * the second tail page: ->mapping is
907 * page_deferred_list().next -- ignore value.
911 if (page
->mapping
!= TAIL_MAPPING
) {
912 bad_page(page
, "corrupted mapping in tail page", 0);
917 if (unlikely(!PageTail(page
))) {
918 bad_page(page
, "PageTail not set", 0);
921 if (unlikely(compound_head(page
) != head_page
)) {
922 bad_page(page
, "compound_head not consistent", 0);
927 page
->mapping
= NULL
;
928 clear_compound_head(page
);
932 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
933 unsigned long zone
, int nid
)
935 set_page_links(page
, zone
, nid
, pfn
);
936 init_page_count(page
);
937 page_mapcount_reset(page
);
938 page_cpupid_reset_last(page
);
940 INIT_LIST_HEAD(&page
->lru
);
941 #ifdef WANT_PAGE_VIRTUAL
942 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
943 if (!is_highmem_idx(zone
))
944 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
948 static void __meminit
__init_single_pfn(unsigned long pfn
, unsigned long zone
,
951 return __init_single_page(pfn_to_page(pfn
), pfn
, zone
, nid
);
954 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
955 static void init_reserved_page(unsigned long pfn
)
960 if (!early_page_uninitialised(pfn
))
963 nid
= early_pfn_to_nid(pfn
);
964 pgdat
= NODE_DATA(nid
);
966 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
967 struct zone
*zone
= &pgdat
->node_zones
[zid
];
969 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
972 __init_single_pfn(pfn
, zid
, nid
);
975 static inline void init_reserved_page(unsigned long pfn
)
978 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
981 * Initialised pages do not have PageReserved set. This function is
982 * called for each range allocated by the bootmem allocator and
983 * marks the pages PageReserved. The remaining valid pages are later
984 * sent to the buddy page allocator.
986 void __meminit
reserve_bootmem_region(unsigned long start
, unsigned long end
)
988 unsigned long start_pfn
= PFN_DOWN(start
);
989 unsigned long end_pfn
= PFN_UP(end
);
991 for (; start_pfn
< end_pfn
; start_pfn
++) {
992 if (pfn_valid(start_pfn
)) {
993 struct page
*page
= pfn_to_page(start_pfn
);
995 init_reserved_page(start_pfn
);
997 /* Avoid false-positive PageTail() */
998 INIT_LIST_HEAD(&page
->lru
);
1000 SetPageReserved(page
);
1005 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
1007 bool compound
= PageCompound(page
);
1010 VM_BUG_ON_PAGE(PageTail(page
), page
);
1011 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
1013 trace_mm_page_free(page
, order
);
1014 kmemcheck_free_shadow(page
, order
);
1015 kasan_free_pages(page
, order
);
1018 page
->mapping
= NULL
;
1019 bad
+= free_pages_check(page
);
1020 for (i
= 1; i
< (1 << order
); i
++) {
1022 bad
+= free_tail_pages_check(page
, page
+ i
);
1023 bad
+= free_pages_check(page
+ i
);
1028 reset_page_owner(page
, order
);
1030 if (!PageHighMem(page
)) {
1031 debug_check_no_locks_freed(page_address(page
),
1032 PAGE_SIZE
<< order
);
1033 debug_check_no_obj_freed(page_address(page
),
1034 PAGE_SIZE
<< order
);
1036 arch_free_page(page
, order
);
1037 kernel_poison_pages(page
, 1 << order
, 0);
1038 kernel_map_pages(page
, 1 << order
, 0);
1043 static void __free_pages_ok(struct page
*page
, unsigned int order
)
1045 unsigned long flags
;
1047 unsigned long pfn
= page_to_pfn(page
);
1049 if (!free_pages_prepare(page
, order
))
1052 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1053 local_irq_save(flags
);
1054 __count_vm_events(PGFREE
, 1 << order
);
1055 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
1056 local_irq_restore(flags
);
1059 static void __init
__free_pages_boot_core(struct page
*page
,
1060 unsigned long pfn
, unsigned int order
)
1062 unsigned int nr_pages
= 1 << order
;
1063 struct page
*p
= page
;
1067 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
1069 __ClearPageReserved(p
);
1070 set_page_count(p
, 0);
1072 __ClearPageReserved(p
);
1073 set_page_count(p
, 0);
1075 page_zone(page
)->managed_pages
+= nr_pages
;
1076 set_page_refcounted(page
);
1077 __free_pages(page
, order
);
1080 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1081 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1083 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1085 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1087 static DEFINE_SPINLOCK(early_pfn_lock
);
1090 spin_lock(&early_pfn_lock
);
1091 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1094 spin_unlock(&early_pfn_lock
);
1100 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1101 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1102 struct mminit_pfnnid_cache
*state
)
1106 nid
= __early_pfn_to_nid(pfn
, state
);
1107 if (nid
>= 0 && nid
!= node
)
1112 /* Only safe to use early in boot when initialisation is single-threaded */
1113 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1115 return meminit_pfn_in_nid(pfn
, node
, &early_pfnnid_cache
);
1120 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1124 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1125 struct mminit_pfnnid_cache
*state
)
1132 void __init
__free_pages_bootmem(struct page
*page
, unsigned long pfn
,
1135 if (early_page_uninitialised(pfn
))
1137 return __free_pages_boot_core(page
, pfn
, order
);
1141 * Check that the whole (or subset of) a pageblock given by the interval of
1142 * [start_pfn, end_pfn) is valid and within the same zone, before scanning it
1143 * with the migration of free compaction scanner. The scanners then need to
1144 * use only pfn_valid_within() check for arches that allow holes within
1147 * Return struct page pointer of start_pfn, or NULL if checks were not passed.
1149 * It's possible on some configurations to have a setup like node0 node1 node0
1150 * i.e. it's possible that all pages within a zones range of pages do not
1151 * belong to a single zone. We assume that a border between node0 and node1
1152 * can occur within a single pageblock, but not a node0 node1 node0
1153 * interleaving within a single pageblock. It is therefore sufficient to check
1154 * the first and last page of a pageblock and avoid checking each individual
1155 * page in a pageblock.
1157 struct page
*__pageblock_pfn_to_page(unsigned long start_pfn
,
1158 unsigned long end_pfn
, struct zone
*zone
)
1160 struct page
*start_page
;
1161 struct page
*end_page
;
1163 /* end_pfn is one past the range we are checking */
1166 if (!pfn_valid(start_pfn
) || !pfn_valid(end_pfn
))
1169 start_page
= pfn_to_page(start_pfn
);
1171 if (page_zone(start_page
) != zone
)
1174 end_page
= pfn_to_page(end_pfn
);
1176 /* This gives a shorter code than deriving page_zone(end_page) */
1177 if (page_zone_id(start_page
) != page_zone_id(end_page
))
1183 void set_zone_contiguous(struct zone
*zone
)
1185 unsigned long block_start_pfn
= zone
->zone_start_pfn
;
1186 unsigned long block_end_pfn
;
1188 block_end_pfn
= ALIGN(block_start_pfn
+ 1, pageblock_nr_pages
);
1189 for (; block_start_pfn
< zone_end_pfn(zone
);
1190 block_start_pfn
= block_end_pfn
,
1191 block_end_pfn
+= pageblock_nr_pages
) {
1193 block_end_pfn
= min(block_end_pfn
, zone_end_pfn(zone
));
1195 if (!__pageblock_pfn_to_page(block_start_pfn
,
1196 block_end_pfn
, zone
))
1200 /* We confirm that there is no hole */
1201 zone
->contiguous
= true;
1204 void clear_zone_contiguous(struct zone
*zone
)
1206 zone
->contiguous
= false;
1209 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1210 static void __init
deferred_free_range(struct page
*page
,
1211 unsigned long pfn
, int nr_pages
)
1218 /* Free a large naturally-aligned chunk if possible */
1219 if (nr_pages
== MAX_ORDER_NR_PAGES
&&
1220 (pfn
& (MAX_ORDER_NR_PAGES
-1)) == 0) {
1221 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1222 __free_pages_boot_core(page
, pfn
, MAX_ORDER
-1);
1226 for (i
= 0; i
< nr_pages
; i
++, page
++, pfn
++)
1227 __free_pages_boot_core(page
, pfn
, 0);
1230 /* Completion tracking for deferred_init_memmap() threads */
1231 static atomic_t pgdat_init_n_undone __initdata
;
1232 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1234 static inline void __init
pgdat_init_report_one_done(void)
1236 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1237 complete(&pgdat_init_all_done_comp
);
1240 /* Initialise remaining memory on a node */
1241 static int __init
deferred_init_memmap(void *data
)
1243 pg_data_t
*pgdat
= data
;
1244 int nid
= pgdat
->node_id
;
1245 struct mminit_pfnnid_cache nid_init_state
= { };
1246 unsigned long start
= jiffies
;
1247 unsigned long nr_pages
= 0;
1248 unsigned long walk_start
, walk_end
;
1251 unsigned long first_init_pfn
= pgdat
->first_deferred_pfn
;
1252 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1254 if (first_init_pfn
== ULONG_MAX
) {
1255 pgdat_init_report_one_done();
1259 /* Bind memory initialisation thread to a local node if possible */
1260 if (!cpumask_empty(cpumask
))
1261 set_cpus_allowed_ptr(current
, cpumask
);
1263 /* Sanity check boundaries */
1264 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1265 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1266 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1268 /* Only the highest zone is deferred so find it */
1269 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1270 zone
= pgdat
->node_zones
+ zid
;
1271 if (first_init_pfn
< zone_end_pfn(zone
))
1275 for_each_mem_pfn_range(i
, nid
, &walk_start
, &walk_end
, NULL
) {
1276 unsigned long pfn
, end_pfn
;
1277 struct page
*page
= NULL
;
1278 struct page
*free_base_page
= NULL
;
1279 unsigned long free_base_pfn
= 0;
1282 end_pfn
= min(walk_end
, zone_end_pfn(zone
));
1283 pfn
= first_init_pfn
;
1284 if (pfn
< walk_start
)
1286 if (pfn
< zone
->zone_start_pfn
)
1287 pfn
= zone
->zone_start_pfn
;
1289 for (; pfn
< end_pfn
; pfn
++) {
1290 if (!pfn_valid_within(pfn
))
1294 * Ensure pfn_valid is checked every
1295 * MAX_ORDER_NR_PAGES for memory holes
1297 if ((pfn
& (MAX_ORDER_NR_PAGES
- 1)) == 0) {
1298 if (!pfn_valid(pfn
)) {
1304 if (!meminit_pfn_in_nid(pfn
, nid
, &nid_init_state
)) {
1309 /* Minimise pfn page lookups and scheduler checks */
1310 if (page
&& (pfn
& (MAX_ORDER_NR_PAGES
- 1)) != 0) {
1313 nr_pages
+= nr_to_free
;
1314 deferred_free_range(free_base_page
,
1315 free_base_pfn
, nr_to_free
);
1316 free_base_page
= NULL
;
1317 free_base_pfn
= nr_to_free
= 0;
1319 page
= pfn_to_page(pfn
);
1324 VM_BUG_ON(page_zone(page
) != zone
);
1328 __init_single_page(page
, pfn
, zid
, nid
);
1329 if (!free_base_page
) {
1330 free_base_page
= page
;
1331 free_base_pfn
= pfn
;
1336 /* Where possible, batch up pages for a single free */
1339 /* Free the current block of pages to allocator */
1340 nr_pages
+= nr_to_free
;
1341 deferred_free_range(free_base_page
, free_base_pfn
,
1343 free_base_page
= NULL
;
1344 free_base_pfn
= nr_to_free
= 0;
1347 first_init_pfn
= max(end_pfn
, first_init_pfn
);
1350 /* Sanity check that the next zone really is unpopulated */
1351 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1353 pr_info("node %d initialised, %lu pages in %ums\n", nid
, nr_pages
,
1354 jiffies_to_msecs(jiffies
- start
));
1356 pgdat_init_report_one_done();
1359 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1361 void __init
page_alloc_init_late(void)
1365 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1368 /* There will be num_node_state(N_MEMORY) threads */
1369 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
1370 for_each_node_state(nid
, N_MEMORY
) {
1371 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
1374 /* Block until all are initialised */
1375 wait_for_completion(&pgdat_init_all_done_comp
);
1377 /* Reinit limits that are based on free pages after the kernel is up */
1378 files_maxfiles_init();
1381 for_each_populated_zone(zone
)
1382 set_zone_contiguous(zone
);
1386 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1387 void __init
init_cma_reserved_pageblock(struct page
*page
)
1389 unsigned i
= pageblock_nr_pages
;
1390 struct page
*p
= page
;
1393 __ClearPageReserved(p
);
1394 set_page_count(p
, 0);
1397 set_pageblock_migratetype(page
, MIGRATE_CMA
);
1399 if (pageblock_order
>= MAX_ORDER
) {
1400 i
= pageblock_nr_pages
;
1403 set_page_refcounted(p
);
1404 __free_pages(p
, MAX_ORDER
- 1);
1405 p
+= MAX_ORDER_NR_PAGES
;
1406 } while (i
-= MAX_ORDER_NR_PAGES
);
1408 set_page_refcounted(page
);
1409 __free_pages(page
, pageblock_order
);
1412 adjust_managed_page_count(page
, pageblock_nr_pages
);
1417 * The order of subdivision here is critical for the IO subsystem.
1418 * Please do not alter this order without good reasons and regression
1419 * testing. Specifically, as large blocks of memory are subdivided,
1420 * the order in which smaller blocks are delivered depends on the order
1421 * they're subdivided in this function. This is the primary factor
1422 * influencing the order in which pages are delivered to the IO
1423 * subsystem according to empirical testing, and this is also justified
1424 * by considering the behavior of a buddy system containing a single
1425 * large block of memory acted on by a series of small allocations.
1426 * This behavior is a critical factor in sglist merging's success.
1430 static inline void expand(struct zone
*zone
, struct page
*page
,
1431 int low
, int high
, struct free_area
*area
,
1434 unsigned long size
= 1 << high
;
1436 while (high
> low
) {
1440 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
1442 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC
) &&
1443 debug_guardpage_enabled() &&
1444 high
< debug_guardpage_minorder()) {
1446 * Mark as guard pages (or page), that will allow to
1447 * merge back to allocator when buddy will be freed.
1448 * Corresponding page table entries will not be touched,
1449 * pages will stay not present in virtual address space
1451 set_page_guard(zone
, &page
[size
], high
, migratetype
);
1454 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
1456 set_page_order(&page
[size
], high
);
1461 * This page is about to be returned from the page allocator
1463 static inline int check_new_page(struct page
*page
)
1465 const char *bad_reason
= NULL
;
1466 unsigned long bad_flags
= 0;
1468 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1469 bad_reason
= "nonzero mapcount";
1470 if (unlikely(page
->mapping
!= NULL
))
1471 bad_reason
= "non-NULL mapping";
1472 if (unlikely(page_ref_count(page
) != 0))
1473 bad_reason
= "nonzero _count";
1474 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
1475 bad_reason
= "HWPoisoned (hardware-corrupted)";
1476 bad_flags
= __PG_HWPOISON
;
1478 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
1479 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
1480 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
1483 if (unlikely(page
->mem_cgroup
))
1484 bad_reason
= "page still charged to cgroup";
1486 if (unlikely(bad_reason
)) {
1487 bad_page(page
, bad_reason
, bad_flags
);
1493 static inline bool free_pages_prezeroed(bool poisoned
)
1495 return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO
) &&
1496 page_poisoning_enabled() && poisoned
;
1499 static int prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
1503 bool poisoned
= true;
1505 for (i
= 0; i
< (1 << order
); i
++) {
1506 struct page
*p
= page
+ i
;
1507 if (unlikely(check_new_page(p
)))
1510 poisoned
&= page_is_poisoned(p
);
1513 set_page_private(page
, 0);
1514 set_page_refcounted(page
);
1516 arch_alloc_page(page
, order
);
1517 kernel_map_pages(page
, 1 << order
, 1);
1518 kernel_poison_pages(page
, 1 << order
, 1);
1519 kasan_alloc_pages(page
, order
);
1521 if (!free_pages_prezeroed(poisoned
) && (gfp_flags
& __GFP_ZERO
))
1522 for (i
= 0; i
< (1 << order
); i
++)
1523 clear_highpage(page
+ i
);
1525 if (order
&& (gfp_flags
& __GFP_COMP
))
1526 prep_compound_page(page
, order
);
1528 set_page_owner(page
, order
, gfp_flags
);
1531 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1532 * allocate the page. The expectation is that the caller is taking
1533 * steps that will free more memory. The caller should avoid the page
1534 * being used for !PFMEMALLOC purposes.
1536 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
1537 set_page_pfmemalloc(page
);
1539 clear_page_pfmemalloc(page
);
1545 * Go through the free lists for the given migratetype and remove
1546 * the smallest available page from the freelists
1549 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
1552 unsigned int current_order
;
1553 struct free_area
*area
;
1556 /* Find a page of the appropriate size in the preferred list */
1557 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
1558 area
= &(zone
->free_area
[current_order
]);
1559 page
= list_first_entry_or_null(&area
->free_list
[migratetype
],
1563 list_del(&page
->lru
);
1564 rmv_page_order(page
);
1566 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1567 set_pcppage_migratetype(page
, migratetype
);
1576 * This array describes the order lists are fallen back to when
1577 * the free lists for the desirable migrate type are depleted
1579 static int fallbacks
[MIGRATE_TYPES
][4] = {
1580 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1581 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1582 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_TYPES
},
1584 [MIGRATE_CMA
] = { MIGRATE_TYPES
}, /* Never used */
1586 #ifdef CONFIG_MEMORY_ISOLATION
1587 [MIGRATE_ISOLATE
] = { MIGRATE_TYPES
}, /* Never used */
1592 static struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1595 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
1598 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1599 unsigned int order
) { return NULL
; }
1603 * Move the free pages in a range to the free lists of the requested type.
1604 * Note that start_page and end_pages are not aligned on a pageblock
1605 * boundary. If alignment is required, use move_freepages_block()
1607 int move_freepages(struct zone
*zone
,
1608 struct page
*start_page
, struct page
*end_page
,
1613 int pages_moved
= 0;
1615 #ifndef CONFIG_HOLES_IN_ZONE
1617 * page_zone is not safe to call in this context when
1618 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1619 * anyway as we check zone boundaries in move_freepages_block().
1620 * Remove at a later date when no bug reports exist related to
1621 * grouping pages by mobility
1623 VM_BUG_ON(page_zone(start_page
) != page_zone(end_page
));
1626 for (page
= start_page
; page
<= end_page
;) {
1627 /* Make sure we are not inadvertently changing nodes */
1628 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
1630 if (!pfn_valid_within(page_to_pfn(page
))) {
1635 if (!PageBuddy(page
)) {
1640 order
= page_order(page
);
1641 list_move(&page
->lru
,
1642 &zone
->free_area
[order
].free_list
[migratetype
]);
1644 pages_moved
+= 1 << order
;
1650 int move_freepages_block(struct zone
*zone
, struct page
*page
,
1653 unsigned long start_pfn
, end_pfn
;
1654 struct page
*start_page
, *end_page
;
1656 start_pfn
= page_to_pfn(page
);
1657 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
1658 start_page
= pfn_to_page(start_pfn
);
1659 end_page
= start_page
+ pageblock_nr_pages
- 1;
1660 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
1662 /* Do not cross zone boundaries */
1663 if (!zone_spans_pfn(zone
, start_pfn
))
1665 if (!zone_spans_pfn(zone
, end_pfn
))
1668 return move_freepages(zone
, start_page
, end_page
, migratetype
);
1671 static void change_pageblock_range(struct page
*pageblock_page
,
1672 int start_order
, int migratetype
)
1674 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1676 while (nr_pageblocks
--) {
1677 set_pageblock_migratetype(pageblock_page
, migratetype
);
1678 pageblock_page
+= pageblock_nr_pages
;
1683 * When we are falling back to another migratetype during allocation, try to
1684 * steal extra free pages from the same pageblocks to satisfy further
1685 * allocations, instead of polluting multiple pageblocks.
1687 * If we are stealing a relatively large buddy page, it is likely there will
1688 * be more free pages in the pageblock, so try to steal them all. For
1689 * reclaimable and unmovable allocations, we steal regardless of page size,
1690 * as fragmentation caused by those allocations polluting movable pageblocks
1691 * is worse than movable allocations stealing from unmovable and reclaimable
1694 static bool can_steal_fallback(unsigned int order
, int start_mt
)
1697 * Leaving this order check is intended, although there is
1698 * relaxed order check in next check. The reason is that
1699 * we can actually steal whole pageblock if this condition met,
1700 * but, below check doesn't guarantee it and that is just heuristic
1701 * so could be changed anytime.
1703 if (order
>= pageblock_order
)
1706 if (order
>= pageblock_order
/ 2 ||
1707 start_mt
== MIGRATE_RECLAIMABLE
||
1708 start_mt
== MIGRATE_UNMOVABLE
||
1709 page_group_by_mobility_disabled
)
1716 * This function implements actual steal behaviour. If order is large enough,
1717 * we can steal whole pageblock. If not, we first move freepages in this
1718 * pageblock and check whether half of pages are moved or not. If half of
1719 * pages are moved, we can change migratetype of pageblock and permanently
1720 * use it's pages as requested migratetype in the future.
1722 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
1725 unsigned int current_order
= page_order(page
);
1728 /* Take ownership for orders >= pageblock_order */
1729 if (current_order
>= pageblock_order
) {
1730 change_pageblock_range(page
, current_order
, start_type
);
1734 pages
= move_freepages_block(zone
, page
, start_type
);
1736 /* Claim the whole block if over half of it is free */
1737 if (pages
>= (1 << (pageblock_order
-1)) ||
1738 page_group_by_mobility_disabled
)
1739 set_pageblock_migratetype(page
, start_type
);
1743 * Check whether there is a suitable fallback freepage with requested order.
1744 * If only_stealable is true, this function returns fallback_mt only if
1745 * we can steal other freepages all together. This would help to reduce
1746 * fragmentation due to mixed migratetype pages in one pageblock.
1748 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
1749 int migratetype
, bool only_stealable
, bool *can_steal
)
1754 if (area
->nr_free
== 0)
1759 fallback_mt
= fallbacks
[migratetype
][i
];
1760 if (fallback_mt
== MIGRATE_TYPES
)
1763 if (list_empty(&area
->free_list
[fallback_mt
]))
1766 if (can_steal_fallback(order
, migratetype
))
1769 if (!only_stealable
)
1780 * Reserve a pageblock for exclusive use of high-order atomic allocations if
1781 * there are no empty page blocks that contain a page with a suitable order
1783 static void reserve_highatomic_pageblock(struct page
*page
, struct zone
*zone
,
1784 unsigned int alloc_order
)
1787 unsigned long max_managed
, flags
;
1790 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
1791 * Check is race-prone but harmless.
1793 max_managed
= (zone
->managed_pages
/ 100) + pageblock_nr_pages
;
1794 if (zone
->nr_reserved_highatomic
>= max_managed
)
1797 spin_lock_irqsave(&zone
->lock
, flags
);
1799 /* Recheck the nr_reserved_highatomic limit under the lock */
1800 if (zone
->nr_reserved_highatomic
>= max_managed
)
1804 mt
= get_pageblock_migratetype(page
);
1805 if (mt
!= MIGRATE_HIGHATOMIC
&&
1806 !is_migrate_isolate(mt
) && !is_migrate_cma(mt
)) {
1807 zone
->nr_reserved_highatomic
+= pageblock_nr_pages
;
1808 set_pageblock_migratetype(page
, MIGRATE_HIGHATOMIC
);
1809 move_freepages_block(zone
, page
, MIGRATE_HIGHATOMIC
);
1813 spin_unlock_irqrestore(&zone
->lock
, flags
);
1817 * Used when an allocation is about to fail under memory pressure. This
1818 * potentially hurts the reliability of high-order allocations when under
1819 * intense memory pressure but failed atomic allocations should be easier
1820 * to recover from than an OOM.
1822 static void unreserve_highatomic_pageblock(const struct alloc_context
*ac
)
1824 struct zonelist
*zonelist
= ac
->zonelist
;
1825 unsigned long flags
;
1831 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
1833 /* Preserve at least one pageblock */
1834 if (zone
->nr_reserved_highatomic
<= pageblock_nr_pages
)
1837 spin_lock_irqsave(&zone
->lock
, flags
);
1838 for (order
= 0; order
< MAX_ORDER
; order
++) {
1839 struct free_area
*area
= &(zone
->free_area
[order
]);
1841 page
= list_first_entry_or_null(
1842 &area
->free_list
[MIGRATE_HIGHATOMIC
],
1848 * It should never happen but changes to locking could
1849 * inadvertently allow a per-cpu drain to add pages
1850 * to MIGRATE_HIGHATOMIC while unreserving so be safe
1851 * and watch for underflows.
1853 zone
->nr_reserved_highatomic
-= min(pageblock_nr_pages
,
1854 zone
->nr_reserved_highatomic
);
1857 * Convert to ac->migratetype and avoid the normal
1858 * pageblock stealing heuristics. Minimally, the caller
1859 * is doing the work and needs the pages. More
1860 * importantly, if the block was always converted to
1861 * MIGRATE_UNMOVABLE or another type then the number
1862 * of pageblocks that cannot be completely freed
1865 set_pageblock_migratetype(page
, ac
->migratetype
);
1866 move_freepages_block(zone
, page
, ac
->migratetype
);
1867 spin_unlock_irqrestore(&zone
->lock
, flags
);
1870 spin_unlock_irqrestore(&zone
->lock
, flags
);
1874 /* Remove an element from the buddy allocator from the fallback list */
1875 static inline struct page
*
1876 __rmqueue_fallback(struct zone
*zone
, unsigned int order
, int start_migratetype
)
1878 struct free_area
*area
;
1879 unsigned int current_order
;
1884 /* Find the largest possible block of pages in the other list */
1885 for (current_order
= MAX_ORDER
-1;
1886 current_order
>= order
&& current_order
<= MAX_ORDER
-1;
1888 area
= &(zone
->free_area
[current_order
]);
1889 fallback_mt
= find_suitable_fallback(area
, current_order
,
1890 start_migratetype
, false, &can_steal
);
1891 if (fallback_mt
== -1)
1894 page
= list_first_entry(&area
->free_list
[fallback_mt
],
1897 steal_suitable_fallback(zone
, page
, start_migratetype
);
1899 /* Remove the page from the freelists */
1901 list_del(&page
->lru
);
1902 rmv_page_order(page
);
1904 expand(zone
, page
, order
, current_order
, area
,
1907 * The pcppage_migratetype may differ from pageblock's
1908 * migratetype depending on the decisions in
1909 * find_suitable_fallback(). This is OK as long as it does not
1910 * differ for MIGRATE_CMA pageblocks. Those can be used as
1911 * fallback only via special __rmqueue_cma_fallback() function
1913 set_pcppage_migratetype(page
, start_migratetype
);
1915 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
1916 start_migratetype
, fallback_mt
);
1925 * Do the hard work of removing an element from the buddy allocator.
1926 * Call me with the zone->lock already held.
1928 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
1933 page
= __rmqueue_smallest(zone
, order
, migratetype
);
1934 if (unlikely(!page
)) {
1935 if (migratetype
== MIGRATE_MOVABLE
)
1936 page
= __rmqueue_cma_fallback(zone
, order
);
1939 page
= __rmqueue_fallback(zone
, order
, migratetype
);
1942 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1947 * Obtain a specified number of elements from the buddy allocator, all under
1948 * a single hold of the lock, for efficiency. Add them to the supplied list.
1949 * Returns the number of new pages which were placed at *list.
1951 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1952 unsigned long count
, struct list_head
*list
,
1953 int migratetype
, bool cold
)
1957 spin_lock(&zone
->lock
);
1958 for (i
= 0; i
< count
; ++i
) {
1959 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
1960 if (unlikely(page
== NULL
))
1964 * Split buddy pages returned by expand() are received here
1965 * in physical page order. The page is added to the callers and
1966 * list and the list head then moves forward. From the callers
1967 * perspective, the linked list is ordered by page number in
1968 * some conditions. This is useful for IO devices that can
1969 * merge IO requests if the physical pages are ordered
1973 list_add(&page
->lru
, list
);
1975 list_add_tail(&page
->lru
, list
);
1977 if (is_migrate_cma(get_pcppage_migratetype(page
)))
1978 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
1981 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
1982 spin_unlock(&zone
->lock
);
1988 * Called from the vmstat counter updater to drain pagesets of this
1989 * currently executing processor on remote nodes after they have
1992 * Note that this function must be called with the thread pinned to
1993 * a single processor.
1995 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
1997 unsigned long flags
;
1998 int to_drain
, batch
;
2000 local_irq_save(flags
);
2001 batch
= READ_ONCE(pcp
->batch
);
2002 to_drain
= min(pcp
->count
, batch
);
2004 free_pcppages_bulk(zone
, to_drain
, pcp
);
2005 pcp
->count
-= to_drain
;
2007 local_irq_restore(flags
);
2012 * Drain pcplists of the indicated processor and zone.
2014 * The processor must either be the current processor and the
2015 * thread pinned to the current processor or a processor that
2018 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
2020 unsigned long flags
;
2021 struct per_cpu_pageset
*pset
;
2022 struct per_cpu_pages
*pcp
;
2024 local_irq_save(flags
);
2025 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
2029 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
2032 local_irq_restore(flags
);
2036 * Drain pcplists of all zones on the indicated processor.
2038 * The processor must either be the current processor and the
2039 * thread pinned to the current processor or a processor that
2042 static void drain_pages(unsigned int cpu
)
2046 for_each_populated_zone(zone
) {
2047 drain_pages_zone(cpu
, zone
);
2052 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
2054 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
2055 * the single zone's pages.
2057 void drain_local_pages(struct zone
*zone
)
2059 int cpu
= smp_processor_id();
2062 drain_pages_zone(cpu
, zone
);
2068 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2070 * When zone parameter is non-NULL, spill just the single zone's pages.
2072 * Note that this code is protected against sending an IPI to an offline
2073 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
2074 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
2075 * nothing keeps CPUs from showing up after we populated the cpumask and
2076 * before the call to on_each_cpu_mask().
2078 void drain_all_pages(struct zone
*zone
)
2083 * Allocate in the BSS so we wont require allocation in
2084 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2086 static cpumask_t cpus_with_pcps
;
2089 * We don't care about racing with CPU hotplug event
2090 * as offline notification will cause the notified
2091 * cpu to drain that CPU pcps and on_each_cpu_mask
2092 * disables preemption as part of its processing
2094 for_each_online_cpu(cpu
) {
2095 struct per_cpu_pageset
*pcp
;
2097 bool has_pcps
= false;
2100 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
2104 for_each_populated_zone(z
) {
2105 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
2106 if (pcp
->pcp
.count
) {
2114 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
2116 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
2118 on_each_cpu_mask(&cpus_with_pcps
, (smp_call_func_t
) drain_local_pages
,
2122 #ifdef CONFIG_HIBERNATION
2124 void mark_free_pages(struct zone
*zone
)
2126 unsigned long pfn
, max_zone_pfn
;
2127 unsigned long flags
;
2128 unsigned int order
, t
;
2131 if (zone_is_empty(zone
))
2134 spin_lock_irqsave(&zone
->lock
, flags
);
2136 max_zone_pfn
= zone_end_pfn(zone
);
2137 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
2138 if (pfn_valid(pfn
)) {
2139 page
= pfn_to_page(pfn
);
2140 if (!swsusp_page_is_forbidden(page
))
2141 swsusp_unset_page_free(page
);
2144 for_each_migratetype_order(order
, t
) {
2145 list_for_each_entry(page
,
2146 &zone
->free_area
[order
].free_list
[t
], lru
) {
2149 pfn
= page_to_pfn(page
);
2150 for (i
= 0; i
< (1UL << order
); i
++)
2151 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
2154 spin_unlock_irqrestore(&zone
->lock
, flags
);
2156 #endif /* CONFIG_PM */
2159 * Free a 0-order page
2160 * cold == true ? free a cold page : free a hot page
2162 void free_hot_cold_page(struct page
*page
, bool cold
)
2164 struct zone
*zone
= page_zone(page
);
2165 struct per_cpu_pages
*pcp
;
2166 unsigned long flags
;
2167 unsigned long pfn
= page_to_pfn(page
);
2170 if (!free_pages_prepare(page
, 0))
2173 migratetype
= get_pfnblock_migratetype(page
, pfn
);
2174 set_pcppage_migratetype(page
, migratetype
);
2175 local_irq_save(flags
);
2176 __count_vm_event(PGFREE
);
2179 * We only track unmovable, reclaimable and movable on pcp lists.
2180 * Free ISOLATE pages back to the allocator because they are being
2181 * offlined but treat RESERVE as movable pages so we can get those
2182 * areas back if necessary. Otherwise, we may have to free
2183 * excessively into the page allocator
2185 if (migratetype
>= MIGRATE_PCPTYPES
) {
2186 if (unlikely(is_migrate_isolate(migratetype
))) {
2187 free_one_page(zone
, page
, pfn
, 0, migratetype
);
2190 migratetype
= MIGRATE_MOVABLE
;
2193 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2195 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
2197 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
2199 if (pcp
->count
>= pcp
->high
) {
2200 unsigned long batch
= READ_ONCE(pcp
->batch
);
2201 free_pcppages_bulk(zone
, batch
, pcp
);
2202 pcp
->count
-= batch
;
2206 local_irq_restore(flags
);
2210 * Free a list of 0-order pages
2212 void free_hot_cold_page_list(struct list_head
*list
, bool cold
)
2214 struct page
*page
, *next
;
2216 list_for_each_entry_safe(page
, next
, list
, lru
) {
2217 trace_mm_page_free_batched(page
, cold
);
2218 free_hot_cold_page(page
, cold
);
2223 * split_page takes a non-compound higher-order page, and splits it into
2224 * n (1<<order) sub-pages: page[0..n]
2225 * Each sub-page must be freed individually.
2227 * Note: this is probably too low level an operation for use in drivers.
2228 * Please consult with lkml before using this in your driver.
2230 void split_page(struct page
*page
, unsigned int order
)
2235 VM_BUG_ON_PAGE(PageCompound(page
), page
);
2236 VM_BUG_ON_PAGE(!page_count(page
), page
);
2238 #ifdef CONFIG_KMEMCHECK
2240 * Split shadow pages too, because free(page[0]) would
2241 * otherwise free the whole shadow.
2243 if (kmemcheck_page_is_tracked(page
))
2244 split_page(virt_to_page(page
[0].shadow
), order
);
2247 gfp_mask
= get_page_owner_gfp(page
);
2248 set_page_owner(page
, 0, gfp_mask
);
2249 for (i
= 1; i
< (1 << order
); i
++) {
2250 set_page_refcounted(page
+ i
);
2251 set_page_owner(page
+ i
, 0, gfp_mask
);
2254 EXPORT_SYMBOL_GPL(split_page
);
2256 int __isolate_free_page(struct page
*page
, unsigned int order
)
2258 unsigned long watermark
;
2262 BUG_ON(!PageBuddy(page
));
2264 zone
= page_zone(page
);
2265 mt
= get_pageblock_migratetype(page
);
2267 if (!is_migrate_isolate(mt
)) {
2268 /* Obey watermarks as if the page was being allocated */
2269 watermark
= low_wmark_pages(zone
) + (1 << order
);
2270 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
2273 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
2276 /* Remove page from free list */
2277 list_del(&page
->lru
);
2278 zone
->free_area
[order
].nr_free
--;
2279 rmv_page_order(page
);
2281 set_page_owner(page
, order
, __GFP_MOVABLE
);
2283 /* Set the pageblock if the isolated page is at least a pageblock */
2284 if (order
>= pageblock_order
- 1) {
2285 struct page
*endpage
= page
+ (1 << order
) - 1;
2286 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
2287 int mt
= get_pageblock_migratetype(page
);
2288 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
))
2289 set_pageblock_migratetype(page
,
2295 return 1UL << order
;
2299 * Similar to split_page except the page is already free. As this is only
2300 * being used for migration, the migratetype of the block also changes.
2301 * As this is called with interrupts disabled, the caller is responsible
2302 * for calling arch_alloc_page() and kernel_map_page() after interrupts
2305 * Note: this is probably too low level an operation for use in drivers.
2306 * Please consult with lkml before using this in your driver.
2308 int split_free_page(struct page
*page
)
2313 order
= page_order(page
);
2315 nr_pages
= __isolate_free_page(page
, order
);
2319 /* Split into individual pages */
2320 set_page_refcounted(page
);
2321 split_page(page
, order
);
2326 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2329 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
2330 struct zone
*zone
, unsigned int order
,
2331 gfp_t gfp_flags
, int alloc_flags
, int migratetype
)
2333 unsigned long flags
;
2335 bool cold
= ((gfp_flags
& __GFP_COLD
) != 0);
2337 if (likely(order
== 0)) {
2338 struct per_cpu_pages
*pcp
;
2339 struct list_head
*list
;
2341 local_irq_save(flags
);
2342 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2343 list
= &pcp
->lists
[migratetype
];
2344 if (list_empty(list
)) {
2345 pcp
->count
+= rmqueue_bulk(zone
, 0,
2348 if (unlikely(list_empty(list
)))
2353 page
= list_last_entry(list
, struct page
, lru
);
2355 page
= list_first_entry(list
, struct page
, lru
);
2357 list_del(&page
->lru
);
2361 * We most definitely don't want callers attempting to
2362 * allocate greater than order-1 page units with __GFP_NOFAIL.
2364 WARN_ON_ONCE((gfp_flags
& __GFP_NOFAIL
) && (order
> 1));
2365 spin_lock_irqsave(&zone
->lock
, flags
);
2368 if (alloc_flags
& ALLOC_HARDER
) {
2369 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
2371 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2374 page
= __rmqueue(zone
, order
, migratetype
);
2375 spin_unlock(&zone
->lock
);
2378 __mod_zone_freepage_state(zone
, -(1 << order
),
2379 get_pcppage_migratetype(page
));
2382 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
, -(1 << order
));
2383 if (atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]) <= 0 &&
2384 !test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
))
2385 set_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2387 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
2388 zone_statistics(preferred_zone
, zone
, gfp_flags
);
2389 local_irq_restore(flags
);
2391 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
2395 local_irq_restore(flags
);
2399 #ifdef CONFIG_FAIL_PAGE_ALLOC
2402 struct fault_attr attr
;
2404 bool ignore_gfp_highmem
;
2405 bool ignore_gfp_reclaim
;
2407 } fail_page_alloc
= {
2408 .attr
= FAULT_ATTR_INITIALIZER
,
2409 .ignore_gfp_reclaim
= true,
2410 .ignore_gfp_highmem
= true,
2414 static int __init
setup_fail_page_alloc(char *str
)
2416 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
2418 __setup("fail_page_alloc=", setup_fail_page_alloc
);
2420 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2422 if (order
< fail_page_alloc
.min_order
)
2424 if (gfp_mask
& __GFP_NOFAIL
)
2426 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
2428 if (fail_page_alloc
.ignore_gfp_reclaim
&&
2429 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
2432 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
2435 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2437 static int __init
fail_page_alloc_debugfs(void)
2439 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
2442 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
2443 &fail_page_alloc
.attr
);
2445 return PTR_ERR(dir
);
2447 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
2448 &fail_page_alloc
.ignore_gfp_reclaim
))
2450 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
2451 &fail_page_alloc
.ignore_gfp_highmem
))
2453 if (!debugfs_create_u32("min-order", mode
, dir
,
2454 &fail_page_alloc
.min_order
))
2459 debugfs_remove_recursive(dir
);
2464 late_initcall(fail_page_alloc_debugfs
);
2466 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2468 #else /* CONFIG_FAIL_PAGE_ALLOC */
2470 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2475 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2478 * Return true if free base pages are above 'mark'. For high-order checks it
2479 * will return true of the order-0 watermark is reached and there is at least
2480 * one free page of a suitable size. Checking now avoids taking the zone lock
2481 * to check in the allocation paths if no pages are free.
2483 static bool __zone_watermark_ok(struct zone
*z
, unsigned int order
,
2484 unsigned long mark
, int classzone_idx
, int alloc_flags
,
2489 const int alloc_harder
= (alloc_flags
& ALLOC_HARDER
);
2491 /* free_pages may go negative - that's OK */
2492 free_pages
-= (1 << order
) - 1;
2494 if (alloc_flags
& ALLOC_HIGH
)
2498 * If the caller does not have rights to ALLOC_HARDER then subtract
2499 * the high-atomic reserves. This will over-estimate the size of the
2500 * atomic reserve but it avoids a search.
2502 if (likely(!alloc_harder
))
2503 free_pages
-= z
->nr_reserved_highatomic
;
2508 /* If allocation can't use CMA areas don't use free CMA pages */
2509 if (!(alloc_flags
& ALLOC_CMA
))
2510 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2514 * Check watermarks for an order-0 allocation request. If these
2515 * are not met, then a high-order request also cannot go ahead
2516 * even if a suitable page happened to be free.
2518 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
2521 /* If this is an order-0 request then the watermark is fine */
2525 /* For a high-order request, check at least one suitable page is free */
2526 for (o
= order
; o
< MAX_ORDER
; o
++) {
2527 struct free_area
*area
= &z
->free_area
[o
];
2536 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
2537 if (!list_empty(&area
->free_list
[mt
]))
2542 if ((alloc_flags
& ALLOC_CMA
) &&
2543 !list_empty(&area
->free_list
[MIGRATE_CMA
])) {
2551 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2552 int classzone_idx
, int alloc_flags
)
2554 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
2555 zone_page_state(z
, NR_FREE_PAGES
));
2558 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
2559 unsigned long mark
, int classzone_idx
)
2561 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
2563 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
2564 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
2566 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, 0,
2571 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2573 return local_zone
->node
== zone
->node
;
2576 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2578 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <
2581 #else /* CONFIG_NUMA */
2582 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2587 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2591 #endif /* CONFIG_NUMA */
2593 static void reset_alloc_batches(struct zone
*preferred_zone
)
2595 struct zone
*zone
= preferred_zone
->zone_pgdat
->node_zones
;
2598 mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
2599 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
2600 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
2601 clear_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2602 } while (zone
++ != preferred_zone
);
2606 * get_page_from_freelist goes through the zonelist trying to allocate
2609 static struct page
*
2610 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
2611 const struct alloc_context
*ac
)
2613 struct zonelist
*zonelist
= ac
->zonelist
;
2615 struct page
*page
= NULL
;
2617 int nr_fair_skipped
= 0;
2618 bool zonelist_rescan
;
2621 zonelist_rescan
= false;
2624 * Scan zonelist, looking for a zone with enough free.
2625 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2627 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
2631 if (cpusets_enabled() &&
2632 (alloc_flags
& ALLOC_CPUSET
) &&
2633 !cpuset_zone_allowed(zone
, gfp_mask
))
2636 * Distribute pages in proportion to the individual
2637 * zone size to ensure fair page aging. The zone a
2638 * page was allocated in should have no effect on the
2639 * time the page has in memory before being reclaimed.
2641 if (alloc_flags
& ALLOC_FAIR
) {
2642 if (!zone_local(ac
->preferred_zone
, zone
))
2644 if (test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
)) {
2650 * When allocating a page cache page for writing, we
2651 * want to get it from a zone that is within its dirty
2652 * limit, such that no single zone holds more than its
2653 * proportional share of globally allowed dirty pages.
2654 * The dirty limits take into account the zone's
2655 * lowmem reserves and high watermark so that kswapd
2656 * should be able to balance it without having to
2657 * write pages from its LRU list.
2659 * This may look like it could increase pressure on
2660 * lower zones by failing allocations in higher zones
2661 * before they are full. But the pages that do spill
2662 * over are limited as the lower zones are protected
2663 * by this very same mechanism. It should not become
2664 * a practical burden to them.
2666 * XXX: For now, allow allocations to potentially
2667 * exceed the per-zone dirty limit in the slowpath
2668 * (spread_dirty_pages unset) before going into reclaim,
2669 * which is important when on a NUMA setup the allowed
2670 * zones are together not big enough to reach the
2671 * global limit. The proper fix for these situations
2672 * will require awareness of zones in the
2673 * dirty-throttling and the flusher threads.
2675 if (ac
->spread_dirty_pages
&& !zone_dirty_ok(zone
))
2678 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
2679 if (!zone_watermark_ok(zone
, order
, mark
,
2680 ac
->classzone_idx
, alloc_flags
)) {
2683 /* Checked here to keep the fast path fast */
2684 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
2685 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
2688 if (zone_reclaim_mode
== 0 ||
2689 !zone_allows_reclaim(ac
->preferred_zone
, zone
))
2692 ret
= zone_reclaim(zone
, gfp_mask
, order
);
2694 case ZONE_RECLAIM_NOSCAN
:
2697 case ZONE_RECLAIM_FULL
:
2698 /* scanned but unreclaimable */
2701 /* did we reclaim enough */
2702 if (zone_watermark_ok(zone
, order
, mark
,
2703 ac
->classzone_idx
, alloc_flags
))
2711 page
= buffered_rmqueue(ac
->preferred_zone
, zone
, order
,
2712 gfp_mask
, alloc_flags
, ac
->migratetype
);
2714 if (prep_new_page(page
, order
, gfp_mask
, alloc_flags
))
2718 * If this is a high-order atomic allocation then check
2719 * if the pageblock should be reserved for the future
2721 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
2722 reserve_highatomic_pageblock(page
, zone
, order
);
2729 * The first pass makes sure allocations are spread fairly within the
2730 * local node. However, the local node might have free pages left
2731 * after the fairness batches are exhausted, and remote zones haven't
2732 * even been considered yet. Try once more without fairness, and
2733 * include remote zones now, before entering the slowpath and waking
2734 * kswapd: prefer spilling to a remote zone over swapping locally.
2736 if (alloc_flags
& ALLOC_FAIR
) {
2737 alloc_flags
&= ~ALLOC_FAIR
;
2738 if (nr_fair_skipped
) {
2739 zonelist_rescan
= true;
2740 reset_alloc_batches(ac
->preferred_zone
);
2742 if (nr_online_nodes
> 1)
2743 zonelist_rescan
= true;
2746 if (zonelist_rescan
)
2753 * Large machines with many possible nodes should not always dump per-node
2754 * meminfo in irq context.
2756 static inline bool should_suppress_show_mem(void)
2761 ret
= in_interrupt();
2766 static DEFINE_RATELIMIT_STATE(nopage_rs
,
2767 DEFAULT_RATELIMIT_INTERVAL
,
2768 DEFAULT_RATELIMIT_BURST
);
2770 void warn_alloc_failed(gfp_t gfp_mask
, unsigned int order
, const char *fmt
, ...)
2772 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
2774 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
2775 debug_guardpage_minorder() > 0)
2779 * This documents exceptions given to allocations in certain
2780 * contexts that are allowed to allocate outside current's set
2783 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2784 if (test_thread_flag(TIF_MEMDIE
) ||
2785 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
2786 filter
&= ~SHOW_MEM_FILTER_NODES
;
2787 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
2788 filter
&= ~SHOW_MEM_FILTER_NODES
;
2791 struct va_format vaf
;
2794 va_start(args
, fmt
);
2799 pr_warn("%pV", &vaf
);
2804 pr_warn("%s: page allocation failure: order:%u, mode:%#x(%pGg)\n",
2805 current
->comm
, order
, gfp_mask
, &gfp_mask
);
2807 if (!should_suppress_show_mem())
2811 static inline struct page
*
2812 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
2813 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
2815 struct oom_control oc
= {
2816 .zonelist
= ac
->zonelist
,
2817 .nodemask
= ac
->nodemask
,
2818 .gfp_mask
= gfp_mask
,
2823 *did_some_progress
= 0;
2826 * Acquire the oom lock. If that fails, somebody else is
2827 * making progress for us.
2829 if (!mutex_trylock(&oom_lock
)) {
2830 *did_some_progress
= 1;
2831 schedule_timeout_uninterruptible(1);
2836 * Go through the zonelist yet one more time, keep very high watermark
2837 * here, this is only to catch a parallel oom killing, we must fail if
2838 * we're still under heavy pressure.
2840 page
= get_page_from_freelist(gfp_mask
| __GFP_HARDWALL
, order
,
2841 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
2845 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2846 /* Coredumps can quickly deplete all memory reserves */
2847 if (current
->flags
& PF_DUMPCORE
)
2849 /* The OOM killer will not help higher order allocs */
2850 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2852 /* The OOM killer does not needlessly kill tasks for lowmem */
2853 if (ac
->high_zoneidx
< ZONE_NORMAL
)
2855 /* The OOM killer does not compensate for IO-less reclaim */
2856 if (!(gfp_mask
& __GFP_FS
)) {
2858 * XXX: Page reclaim didn't yield anything,
2859 * and the OOM killer can't be invoked, but
2860 * keep looping as per tradition.
2862 * But do not keep looping if oom_killer_disable()
2863 * was already called, for the system is trying to
2864 * enter a quiescent state during suspend.
2866 *did_some_progress
= !oom_killer_disabled
;
2869 if (pm_suspended_storage())
2871 /* The OOM killer may not free memory on a specific node */
2872 if (gfp_mask
& __GFP_THISNODE
)
2875 /* Exhausted what can be done so it's blamo time */
2876 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
2877 *did_some_progress
= 1;
2879 if (gfp_mask
& __GFP_NOFAIL
) {
2880 page
= get_page_from_freelist(gfp_mask
, order
,
2881 ALLOC_NO_WATERMARKS
|ALLOC_CPUSET
, ac
);
2883 * fallback to ignore cpuset restriction if our nodes
2887 page
= get_page_from_freelist(gfp_mask
, order
,
2888 ALLOC_NO_WATERMARKS
, ac
);
2892 mutex_unlock(&oom_lock
);
2896 #ifdef CONFIG_COMPACTION
2897 /* Try memory compaction for high-order allocations before reclaim */
2898 static struct page
*
2899 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2900 int alloc_flags
, const struct alloc_context
*ac
,
2901 enum migrate_mode mode
, int *contended_compaction
,
2902 bool *deferred_compaction
)
2904 unsigned long compact_result
;
2910 current
->flags
|= PF_MEMALLOC
;
2911 compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
2912 mode
, contended_compaction
);
2913 current
->flags
&= ~PF_MEMALLOC
;
2915 switch (compact_result
) {
2916 case COMPACT_DEFERRED
:
2917 *deferred_compaction
= true;
2919 case COMPACT_SKIPPED
:
2926 * At least in one zone compaction wasn't deferred or skipped, so let's
2927 * count a compaction stall
2929 count_vm_event(COMPACTSTALL
);
2931 page
= get_page_from_freelist(gfp_mask
, order
,
2932 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
2935 struct zone
*zone
= page_zone(page
);
2937 zone
->compact_blockskip_flush
= false;
2938 compaction_defer_reset(zone
, order
, true);
2939 count_vm_event(COMPACTSUCCESS
);
2944 * It's bad if compaction run occurs and fails. The most likely reason
2945 * is that pages exist, but not enough to satisfy watermarks.
2947 count_vm_event(COMPACTFAIL
);
2954 static inline struct page
*
2955 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2956 int alloc_flags
, const struct alloc_context
*ac
,
2957 enum migrate_mode mode
, int *contended_compaction
,
2958 bool *deferred_compaction
)
2962 #endif /* CONFIG_COMPACTION */
2964 /* Perform direct synchronous page reclaim */
2966 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
2967 const struct alloc_context
*ac
)
2969 struct reclaim_state reclaim_state
;
2974 /* We now go into synchronous reclaim */
2975 cpuset_memory_pressure_bump();
2976 current
->flags
|= PF_MEMALLOC
;
2977 lockdep_set_current_reclaim_state(gfp_mask
);
2978 reclaim_state
.reclaimed_slab
= 0;
2979 current
->reclaim_state
= &reclaim_state
;
2981 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
2984 current
->reclaim_state
= NULL
;
2985 lockdep_clear_current_reclaim_state();
2986 current
->flags
&= ~PF_MEMALLOC
;
2993 /* The really slow allocator path where we enter direct reclaim */
2994 static inline struct page
*
2995 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
2996 int alloc_flags
, const struct alloc_context
*ac
,
2997 unsigned long *did_some_progress
)
2999 struct page
*page
= NULL
;
3000 bool drained
= false;
3002 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
3003 if (unlikely(!(*did_some_progress
)))
3007 page
= get_page_from_freelist(gfp_mask
, order
,
3008 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3011 * If an allocation failed after direct reclaim, it could be because
3012 * pages are pinned on the per-cpu lists or in high alloc reserves.
3013 * Shrink them them and try again
3015 if (!page
&& !drained
) {
3016 unreserve_highatomic_pageblock(ac
);
3017 drain_all_pages(NULL
);
3025 static void wake_all_kswapds(unsigned int order
, const struct alloc_context
*ac
)
3030 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
3031 ac
->high_zoneidx
, ac
->nodemask
)
3032 wakeup_kswapd(zone
, order
, zone_idx(ac
->preferred_zone
));
3036 gfp_to_alloc_flags(gfp_t gfp_mask
)
3038 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
3040 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
3041 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
3044 * The caller may dip into page reserves a bit more if the caller
3045 * cannot run direct reclaim, or if the caller has realtime scheduling
3046 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3047 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3049 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
3051 if (gfp_mask
& __GFP_ATOMIC
) {
3053 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3054 * if it can't schedule.
3056 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3057 alloc_flags
|= ALLOC_HARDER
;
3059 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3060 * comment for __cpuset_node_allowed().
3062 alloc_flags
&= ~ALLOC_CPUSET
;
3063 } else if (unlikely(rt_task(current
)) && !in_interrupt())
3064 alloc_flags
|= ALLOC_HARDER
;
3066 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
3067 if (gfp_mask
& __GFP_MEMALLOC
)
3068 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3069 else if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
3070 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3071 else if (!in_interrupt() &&
3072 ((current
->flags
& PF_MEMALLOC
) ||
3073 unlikely(test_thread_flag(TIF_MEMDIE
))))
3074 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3077 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
3078 alloc_flags
|= ALLOC_CMA
;
3083 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
3085 return !!(gfp_to_alloc_flags(gfp_mask
) & ALLOC_NO_WATERMARKS
);
3088 static inline bool is_thp_gfp_mask(gfp_t gfp_mask
)
3090 return (gfp_mask
& (GFP_TRANSHUGE
| __GFP_KSWAPD_RECLAIM
)) == GFP_TRANSHUGE
;
3093 static inline struct page
*
3094 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
3095 struct alloc_context
*ac
)
3097 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
3098 struct page
*page
= NULL
;
3100 unsigned long pages_reclaimed
= 0;
3101 unsigned long did_some_progress
;
3102 enum migrate_mode migration_mode
= MIGRATE_ASYNC
;
3103 bool deferred_compaction
= false;
3104 int contended_compaction
= COMPACT_CONTENDED_NONE
;
3107 * In the slowpath, we sanity check order to avoid ever trying to
3108 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3109 * be using allocators in order of preference for an area that is
3112 if (order
>= MAX_ORDER
) {
3113 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
3118 * We also sanity check to catch abuse of atomic reserves being used by
3119 * callers that are not in atomic context.
3121 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
3122 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
3123 gfp_mask
&= ~__GFP_ATOMIC
;
3126 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3127 wake_all_kswapds(order
, ac
);
3130 * OK, we're below the kswapd watermark and have kicked background
3131 * reclaim. Now things get more complex, so set up alloc_flags according
3132 * to how we want to proceed.
3134 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
3137 * Find the true preferred zone if the allocation is unconstrained by
3140 if (!(alloc_flags
& ALLOC_CPUSET
) && !ac
->nodemask
) {
3141 struct zoneref
*preferred_zoneref
;
3142 preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3143 ac
->high_zoneidx
, NULL
, &ac
->preferred_zone
);
3144 ac
->classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
3147 /* This is the last chance, in general, before the goto nopage. */
3148 page
= get_page_from_freelist(gfp_mask
, order
,
3149 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3153 /* Allocate without watermarks if the context allows */
3154 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
3156 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
3157 * the allocation is high priority and these type of
3158 * allocations are system rather than user orientated
3160 ac
->zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
3161 page
= get_page_from_freelist(gfp_mask
, order
,
3162 ALLOC_NO_WATERMARKS
, ac
);
3167 /* Caller is not willing to reclaim, we can't balance anything */
3168 if (!can_direct_reclaim
) {
3170 * All existing users of the __GFP_NOFAIL are blockable, so warn
3171 * of any new users that actually allow this type of allocation
3174 WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
);
3178 /* Avoid recursion of direct reclaim */
3179 if (current
->flags
& PF_MEMALLOC
) {
3181 * __GFP_NOFAIL request from this context is rather bizarre
3182 * because we cannot reclaim anything and only can loop waiting
3183 * for somebody to do a work for us.
3185 if (WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3192 /* Avoid allocations with no watermarks from looping endlessly */
3193 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
3197 * Try direct compaction. The first pass is asynchronous. Subsequent
3198 * attempts after direct reclaim are synchronous
3200 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
3202 &contended_compaction
,
3203 &deferred_compaction
);
3207 /* Checks for THP-specific high-order allocations */
3208 if (is_thp_gfp_mask(gfp_mask
)) {
3210 * If compaction is deferred for high-order allocations, it is
3211 * because sync compaction recently failed. If this is the case
3212 * and the caller requested a THP allocation, we do not want
3213 * to heavily disrupt the system, so we fail the allocation
3214 * instead of entering direct reclaim.
3216 if (deferred_compaction
)
3220 * In all zones where compaction was attempted (and not
3221 * deferred or skipped), lock contention has been detected.
3222 * For THP allocation we do not want to disrupt the others
3223 * so we fallback to base pages instead.
3225 if (contended_compaction
== COMPACT_CONTENDED_LOCK
)
3229 * If compaction was aborted due to need_resched(), we do not
3230 * want to further increase allocation latency, unless it is
3231 * khugepaged trying to collapse.
3233 if (contended_compaction
== COMPACT_CONTENDED_SCHED
3234 && !(current
->flags
& PF_KTHREAD
))
3239 * It can become very expensive to allocate transparent hugepages at
3240 * fault, so use asynchronous memory compaction for THP unless it is
3241 * khugepaged trying to collapse.
3243 if (!is_thp_gfp_mask(gfp_mask
) || (current
->flags
& PF_KTHREAD
))
3244 migration_mode
= MIGRATE_SYNC_LIGHT
;
3246 /* Try direct reclaim and then allocating */
3247 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
3248 &did_some_progress
);
3252 /* Do not loop if specifically requested */
3253 if (gfp_mask
& __GFP_NORETRY
)
3256 /* Keep reclaiming pages as long as there is reasonable progress */
3257 pages_reclaimed
+= did_some_progress
;
3258 if ((did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
) ||
3259 ((gfp_mask
& __GFP_REPEAT
) && pages_reclaimed
< (1 << order
))) {
3260 /* Wait for some write requests to complete then retry */
3261 wait_iff_congested(ac
->preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
3265 /* Reclaim has failed us, start killing things */
3266 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
3270 /* Retry as long as the OOM killer is making progress */
3271 if (did_some_progress
)
3276 * High-order allocations do not necessarily loop after
3277 * direct reclaim and reclaim/compaction depends on compaction
3278 * being called after reclaim so call directly if necessary
3280 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
,
3282 &contended_compaction
,
3283 &deferred_compaction
);
3287 warn_alloc_failed(gfp_mask
, order
, NULL
);
3293 * This is the 'heart' of the zoned buddy allocator.
3296 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
3297 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
3299 struct zoneref
*preferred_zoneref
;
3300 struct page
*page
= NULL
;
3301 unsigned int cpuset_mems_cookie
;
3302 int alloc_flags
= ALLOC_WMARK_LOW
|ALLOC_CPUSET
|ALLOC_FAIR
;
3303 gfp_t alloc_mask
; /* The gfp_t that was actually used for allocation */
3304 struct alloc_context ac
= {
3305 .high_zoneidx
= gfp_zone(gfp_mask
),
3306 .nodemask
= nodemask
,
3307 .migratetype
= gfpflags_to_migratetype(gfp_mask
),
3310 gfp_mask
&= gfp_allowed_mask
;
3312 lockdep_trace_alloc(gfp_mask
);
3314 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
3316 if (should_fail_alloc_page(gfp_mask
, order
))
3320 * Check the zones suitable for the gfp_mask contain at least one
3321 * valid zone. It's possible to have an empty zonelist as a result
3322 * of __GFP_THISNODE and a memoryless node
3324 if (unlikely(!zonelist
->_zonerefs
->zone
))
3327 if (IS_ENABLED(CONFIG_CMA
) && ac
.migratetype
== MIGRATE_MOVABLE
)
3328 alloc_flags
|= ALLOC_CMA
;
3331 cpuset_mems_cookie
= read_mems_allowed_begin();
3333 /* We set it here, as __alloc_pages_slowpath might have changed it */
3334 ac
.zonelist
= zonelist
;
3336 /* Dirty zone balancing only done in the fast path */
3337 ac
.spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
3339 /* The preferred zone is used for statistics later */
3340 preferred_zoneref
= first_zones_zonelist(ac
.zonelist
, ac
.high_zoneidx
,
3341 ac
.nodemask
? : &cpuset_current_mems_allowed
,
3342 &ac
.preferred_zone
);
3343 if (!ac
.preferred_zone
)
3345 ac
.classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
3347 /* First allocation attempt */
3348 alloc_mask
= gfp_mask
|__GFP_HARDWALL
;
3349 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
3350 if (unlikely(!page
)) {
3352 * Runtime PM, block IO and its error handling path
3353 * can deadlock because I/O on the device might not
3356 alloc_mask
= memalloc_noio_flags(gfp_mask
);
3357 ac
.spread_dirty_pages
= false;
3359 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
3362 if (kmemcheck_enabled
&& page
)
3363 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
3365 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
3369 * When updating a task's mems_allowed, it is possible to race with
3370 * parallel threads in such a way that an allocation can fail while
3371 * the mask is being updated. If a page allocation is about to fail,
3372 * check if the cpuset changed during allocation and if so, retry.
3374 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
)))
3379 EXPORT_SYMBOL(__alloc_pages_nodemask
);
3382 * Common helper functions.
3384 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
3389 * __get_free_pages() returns a 32-bit address, which cannot represent
3392 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
3394 page
= alloc_pages(gfp_mask
, order
);
3397 return (unsigned long) page_address(page
);
3399 EXPORT_SYMBOL(__get_free_pages
);
3401 unsigned long get_zeroed_page(gfp_t gfp_mask
)
3403 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
3405 EXPORT_SYMBOL(get_zeroed_page
);
3407 void __free_pages(struct page
*page
, unsigned int order
)
3409 if (put_page_testzero(page
)) {
3411 free_hot_cold_page(page
, false);
3413 __free_pages_ok(page
, order
);
3417 EXPORT_SYMBOL(__free_pages
);
3419 void free_pages(unsigned long addr
, unsigned int order
)
3422 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3423 __free_pages(virt_to_page((void *)addr
), order
);
3427 EXPORT_SYMBOL(free_pages
);
3431 * An arbitrary-length arbitrary-offset area of memory which resides
3432 * within a 0 or higher order page. Multiple fragments within that page
3433 * are individually refcounted, in the page's reference counter.
3435 * The page_frag functions below provide a simple allocation framework for
3436 * page fragments. This is used by the network stack and network device
3437 * drivers to provide a backing region of memory for use as either an
3438 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3440 static struct page
*__page_frag_refill(struct page_frag_cache
*nc
,
3443 struct page
*page
= NULL
;
3444 gfp_t gfp
= gfp_mask
;
3446 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3447 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
3449 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
3450 PAGE_FRAG_CACHE_MAX_ORDER
);
3451 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
3453 if (unlikely(!page
))
3454 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
3456 nc
->va
= page
? page_address(page
) : NULL
;
3461 void *__alloc_page_frag(struct page_frag_cache
*nc
,
3462 unsigned int fragsz
, gfp_t gfp_mask
)
3464 unsigned int size
= PAGE_SIZE
;
3468 if (unlikely(!nc
->va
)) {
3470 page
= __page_frag_refill(nc
, gfp_mask
);
3474 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3475 /* if size can vary use size else just use PAGE_SIZE */
3478 /* Even if we own the page, we do not use atomic_set().
3479 * This would break get_page_unless_zero() users.
3481 page_ref_add(page
, size
- 1);
3483 /* reset page count bias and offset to start of new frag */
3484 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
3485 nc
->pagecnt_bias
= size
;
3489 offset
= nc
->offset
- fragsz
;
3490 if (unlikely(offset
< 0)) {
3491 page
= virt_to_page(nc
->va
);
3493 if (!page_ref_sub_and_test(page
, nc
->pagecnt_bias
))
3496 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3497 /* if size can vary use size else just use PAGE_SIZE */
3500 /* OK, page count is 0, we can safely set it */
3501 set_page_count(page
, size
);
3503 /* reset page count bias and offset to start of new frag */
3504 nc
->pagecnt_bias
= size
;
3505 offset
= size
- fragsz
;
3509 nc
->offset
= offset
;
3511 return nc
->va
+ offset
;
3513 EXPORT_SYMBOL(__alloc_page_frag
);
3516 * Frees a page fragment allocated out of either a compound or order 0 page.
3518 void __free_page_frag(void *addr
)
3520 struct page
*page
= virt_to_head_page(addr
);
3522 if (unlikely(put_page_testzero(page
)))
3523 __free_pages_ok(page
, compound_order(page
));
3525 EXPORT_SYMBOL(__free_page_frag
);
3528 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
3529 * of the current memory cgroup if __GFP_ACCOUNT is set, other than that it is
3530 * equivalent to alloc_pages.
3532 * It should be used when the caller would like to use kmalloc, but since the
3533 * allocation is large, it has to fall back to the page allocator.
3535 struct page
*alloc_kmem_pages(gfp_t gfp_mask
, unsigned int order
)
3539 page
= alloc_pages(gfp_mask
, order
);
3540 if (page
&& memcg_kmem_charge(page
, gfp_mask
, order
) != 0) {
3541 __free_pages(page
, order
);
3547 struct page
*alloc_kmem_pages_node(int nid
, gfp_t gfp_mask
, unsigned int order
)
3551 page
= alloc_pages_node(nid
, gfp_mask
, order
);
3552 if (page
&& memcg_kmem_charge(page
, gfp_mask
, order
) != 0) {
3553 __free_pages(page
, order
);
3560 * __free_kmem_pages and free_kmem_pages will free pages allocated with
3563 void __free_kmem_pages(struct page
*page
, unsigned int order
)
3565 memcg_kmem_uncharge(page
, order
);
3566 __free_pages(page
, order
);
3569 void free_kmem_pages(unsigned long addr
, unsigned int order
)
3572 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3573 __free_kmem_pages(virt_to_page((void *)addr
), order
);
3577 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
3581 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
3582 unsigned long used
= addr
+ PAGE_ALIGN(size
);
3584 split_page(virt_to_page((void *)addr
), order
);
3585 while (used
< alloc_end
) {
3590 return (void *)addr
;
3594 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
3595 * @size: the number of bytes to allocate
3596 * @gfp_mask: GFP flags for the allocation
3598 * This function is similar to alloc_pages(), except that it allocates the
3599 * minimum number of pages to satisfy the request. alloc_pages() can only
3600 * allocate memory in power-of-two pages.
3602 * This function is also limited by MAX_ORDER.
3604 * Memory allocated by this function must be released by free_pages_exact().
3606 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
3608 unsigned int order
= get_order(size
);
3611 addr
= __get_free_pages(gfp_mask
, order
);
3612 return make_alloc_exact(addr
, order
, size
);
3614 EXPORT_SYMBOL(alloc_pages_exact
);
3617 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3619 * @nid: the preferred node ID where memory should be allocated
3620 * @size: the number of bytes to allocate
3621 * @gfp_mask: GFP flags for the allocation
3623 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3626 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
3628 unsigned int order
= get_order(size
);
3629 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
3632 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
3636 * free_pages_exact - release memory allocated via alloc_pages_exact()
3637 * @virt: the value returned by alloc_pages_exact.
3638 * @size: size of allocation, same value as passed to alloc_pages_exact().
3640 * Release the memory allocated by a previous call to alloc_pages_exact.
3642 void free_pages_exact(void *virt
, size_t size
)
3644 unsigned long addr
= (unsigned long)virt
;
3645 unsigned long end
= addr
+ PAGE_ALIGN(size
);
3647 while (addr
< end
) {
3652 EXPORT_SYMBOL(free_pages_exact
);
3655 * nr_free_zone_pages - count number of pages beyond high watermark
3656 * @offset: The zone index of the highest zone
3658 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3659 * high watermark within all zones at or below a given zone index. For each
3660 * zone, the number of pages is calculated as:
3661 * managed_pages - high_pages
3663 static unsigned long nr_free_zone_pages(int offset
)
3668 /* Just pick one node, since fallback list is circular */
3669 unsigned long sum
= 0;
3671 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
3673 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
3674 unsigned long size
= zone
->managed_pages
;
3675 unsigned long high
= high_wmark_pages(zone
);
3684 * nr_free_buffer_pages - count number of pages beyond high watermark
3686 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3687 * watermark within ZONE_DMA and ZONE_NORMAL.
3689 unsigned long nr_free_buffer_pages(void)
3691 return nr_free_zone_pages(gfp_zone(GFP_USER
));
3693 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
3696 * nr_free_pagecache_pages - count number of pages beyond high watermark
3698 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3699 * high watermark within all zones.
3701 unsigned long nr_free_pagecache_pages(void)
3703 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
3706 static inline void show_node(struct zone
*zone
)
3708 if (IS_ENABLED(CONFIG_NUMA
))
3709 printk("Node %d ", zone_to_nid(zone
));
3712 long si_mem_available(void)
3715 unsigned long pagecache
;
3716 unsigned long wmark_low
= 0;
3717 unsigned long pages
[NR_LRU_LISTS
];
3721 for (lru
= LRU_BASE
; lru
< NR_LRU_LISTS
; lru
++)
3722 pages
[lru
] = global_page_state(NR_LRU_BASE
+ lru
);
3725 wmark_low
+= zone
->watermark
[WMARK_LOW
];
3728 * Estimate the amount of memory available for userspace allocations,
3729 * without causing swapping.
3731 available
= global_page_state(NR_FREE_PAGES
) - totalreserve_pages
;
3734 * Not all the page cache can be freed, otherwise the system will
3735 * start swapping. Assume at least half of the page cache, or the
3736 * low watermark worth of cache, needs to stay.
3738 pagecache
= pages
[LRU_ACTIVE_FILE
] + pages
[LRU_INACTIVE_FILE
];
3739 pagecache
-= min(pagecache
/ 2, wmark_low
);
3740 available
+= pagecache
;
3743 * Part of the reclaimable slab consists of items that are in use,
3744 * and cannot be freed. Cap this estimate at the low watermark.
3746 available
+= global_page_state(NR_SLAB_RECLAIMABLE
) -
3747 min(global_page_state(NR_SLAB_RECLAIMABLE
) / 2, wmark_low
);
3753 EXPORT_SYMBOL_GPL(si_mem_available
);
3755 void si_meminfo(struct sysinfo
*val
)
3757 val
->totalram
= totalram_pages
;
3758 val
->sharedram
= global_page_state(NR_SHMEM
);
3759 val
->freeram
= global_page_state(NR_FREE_PAGES
);
3760 val
->bufferram
= nr_blockdev_pages();
3761 val
->totalhigh
= totalhigh_pages
;
3762 val
->freehigh
= nr_free_highpages();
3763 val
->mem_unit
= PAGE_SIZE
;
3766 EXPORT_SYMBOL(si_meminfo
);
3769 void si_meminfo_node(struct sysinfo
*val
, int nid
)
3771 int zone_type
; /* needs to be signed */
3772 unsigned long managed_pages
= 0;
3773 pg_data_t
*pgdat
= NODE_DATA(nid
);
3775 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
3776 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
3777 val
->totalram
= managed_pages
;
3778 val
->sharedram
= node_page_state(nid
, NR_SHMEM
);
3779 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
3780 #ifdef CONFIG_HIGHMEM
3781 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].managed_pages
;
3782 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
3788 val
->mem_unit
= PAGE_SIZE
;
3793 * Determine whether the node should be displayed or not, depending on whether
3794 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3796 bool skip_free_areas_node(unsigned int flags
, int nid
)
3799 unsigned int cpuset_mems_cookie
;
3801 if (!(flags
& SHOW_MEM_FILTER_NODES
))
3805 cpuset_mems_cookie
= read_mems_allowed_begin();
3806 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
3807 } while (read_mems_allowed_retry(cpuset_mems_cookie
));
3812 #define K(x) ((x) << (PAGE_SHIFT-10))
3814 static void show_migration_types(unsigned char type
)
3816 static const char types
[MIGRATE_TYPES
] = {
3817 [MIGRATE_UNMOVABLE
] = 'U',
3818 [MIGRATE_MOVABLE
] = 'M',
3819 [MIGRATE_RECLAIMABLE
] = 'E',
3820 [MIGRATE_HIGHATOMIC
] = 'H',
3822 [MIGRATE_CMA
] = 'C',
3824 #ifdef CONFIG_MEMORY_ISOLATION
3825 [MIGRATE_ISOLATE
] = 'I',
3828 char tmp
[MIGRATE_TYPES
+ 1];
3832 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
3833 if (type
& (1 << i
))
3838 printk("(%s) ", tmp
);
3842 * Show free area list (used inside shift_scroll-lock stuff)
3843 * We also calculate the percentage fragmentation. We do this by counting the
3844 * memory on each free list with the exception of the first item on the list.
3847 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
3850 void show_free_areas(unsigned int filter
)
3852 unsigned long free_pcp
= 0;
3856 for_each_populated_zone(zone
) {
3857 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3860 for_each_online_cpu(cpu
)
3861 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
3864 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3865 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3866 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
3867 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3868 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3869 " free:%lu free_pcp:%lu free_cma:%lu\n",
3870 global_page_state(NR_ACTIVE_ANON
),
3871 global_page_state(NR_INACTIVE_ANON
),
3872 global_page_state(NR_ISOLATED_ANON
),
3873 global_page_state(NR_ACTIVE_FILE
),
3874 global_page_state(NR_INACTIVE_FILE
),
3875 global_page_state(NR_ISOLATED_FILE
),
3876 global_page_state(NR_UNEVICTABLE
),
3877 global_page_state(NR_FILE_DIRTY
),
3878 global_page_state(NR_WRITEBACK
),
3879 global_page_state(NR_UNSTABLE_NFS
),
3880 global_page_state(NR_SLAB_RECLAIMABLE
),
3881 global_page_state(NR_SLAB_UNRECLAIMABLE
),
3882 global_page_state(NR_FILE_MAPPED
),
3883 global_page_state(NR_SHMEM
),
3884 global_page_state(NR_PAGETABLE
),
3885 global_page_state(NR_BOUNCE
),
3886 global_page_state(NR_FREE_PAGES
),
3888 global_page_state(NR_FREE_CMA_PAGES
));
3890 for_each_populated_zone(zone
) {
3893 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3897 for_each_online_cpu(cpu
)
3898 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
3906 " active_anon:%lukB"
3907 " inactive_anon:%lukB"
3908 " active_file:%lukB"
3909 " inactive_file:%lukB"
3910 " unevictable:%lukB"
3911 " isolated(anon):%lukB"
3912 " isolated(file):%lukB"
3920 " slab_reclaimable:%lukB"
3921 " slab_unreclaimable:%lukB"
3922 " kernel_stack:%lukB"
3929 " writeback_tmp:%lukB"
3930 " pages_scanned:%lu"
3931 " all_unreclaimable? %s"
3934 K(zone_page_state(zone
, NR_FREE_PAGES
)),
3935 K(min_wmark_pages(zone
)),
3936 K(low_wmark_pages(zone
)),
3937 K(high_wmark_pages(zone
)),
3938 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
3939 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
3940 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
3941 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
3942 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
3943 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
3944 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
3945 K(zone
->present_pages
),
3946 K(zone
->managed_pages
),
3947 K(zone_page_state(zone
, NR_MLOCK
)),
3948 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
3949 K(zone_page_state(zone
, NR_WRITEBACK
)),
3950 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
3951 K(zone_page_state(zone
, NR_SHMEM
)),
3952 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
3953 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
3954 zone_page_state(zone
, NR_KERNEL_STACK
) *
3956 K(zone_page_state(zone
, NR_PAGETABLE
)),
3957 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
3958 K(zone_page_state(zone
, NR_BOUNCE
)),
3960 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
3961 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)),
3962 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
3963 K(zone_page_state(zone
, NR_PAGES_SCANNED
)),
3964 (!zone_reclaimable(zone
) ? "yes" : "no")
3966 printk("lowmem_reserve[]:");
3967 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3968 printk(" %ld", zone
->lowmem_reserve
[i
]);
3972 for_each_populated_zone(zone
) {
3974 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
3975 unsigned char types
[MAX_ORDER
];
3977 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3980 printk("%s: ", zone
->name
);
3982 spin_lock_irqsave(&zone
->lock
, flags
);
3983 for (order
= 0; order
< MAX_ORDER
; order
++) {
3984 struct free_area
*area
= &zone
->free_area
[order
];
3987 nr
[order
] = area
->nr_free
;
3988 total
+= nr
[order
] << order
;
3991 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
3992 if (!list_empty(&area
->free_list
[type
]))
3993 types
[order
] |= 1 << type
;
3996 spin_unlock_irqrestore(&zone
->lock
, flags
);
3997 for (order
= 0; order
< MAX_ORDER
; order
++) {
3998 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
4000 show_migration_types(types
[order
]);
4002 printk("= %lukB\n", K(total
));
4005 hugetlb_show_meminfo();
4007 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
4009 show_swap_cache_info();
4012 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
4014 zoneref
->zone
= zone
;
4015 zoneref
->zone_idx
= zone_idx(zone
);
4019 * Builds allocation fallback zone lists.
4021 * Add all populated zones of a node to the zonelist.
4023 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
4027 enum zone_type zone_type
= MAX_NR_ZONES
;
4031 zone
= pgdat
->node_zones
+ zone_type
;
4032 if (populated_zone(zone
)) {
4033 zoneref_set_zone(zone
,
4034 &zonelist
->_zonerefs
[nr_zones
++]);
4035 check_highest_zone(zone_type
);
4037 } while (zone_type
);
4045 * 0 = automatic detection of better ordering.
4046 * 1 = order by ([node] distance, -zonetype)
4047 * 2 = order by (-zonetype, [node] distance)
4049 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
4050 * the same zonelist. So only NUMA can configure this param.
4052 #define ZONELIST_ORDER_DEFAULT 0
4053 #define ZONELIST_ORDER_NODE 1
4054 #define ZONELIST_ORDER_ZONE 2
4056 /* zonelist order in the kernel.
4057 * set_zonelist_order() will set this to NODE or ZONE.
4059 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4060 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
4064 /* The value user specified ....changed by config */
4065 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4066 /* string for sysctl */
4067 #define NUMA_ZONELIST_ORDER_LEN 16
4068 char numa_zonelist_order
[16] = "default";
4071 * interface for configure zonelist ordering.
4072 * command line option "numa_zonelist_order"
4073 * = "[dD]efault - default, automatic configuration.
4074 * = "[nN]ode - order by node locality, then by zone within node
4075 * = "[zZ]one - order by zone, then by locality within zone
4078 static int __parse_numa_zonelist_order(char *s
)
4080 if (*s
== 'd' || *s
== 'D') {
4081 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
4082 } else if (*s
== 'n' || *s
== 'N') {
4083 user_zonelist_order
= ZONELIST_ORDER_NODE
;
4084 } else if (*s
== 'z' || *s
== 'Z') {
4085 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
4087 pr_warn("Ignoring invalid numa_zonelist_order value: %s\n", s
);
4093 static __init
int setup_numa_zonelist_order(char *s
)
4100 ret
= __parse_numa_zonelist_order(s
);
4102 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
4106 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
4109 * sysctl handler for numa_zonelist_order
4111 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
4112 void __user
*buffer
, size_t *length
,
4115 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
4117 static DEFINE_MUTEX(zl_order_mutex
);
4119 mutex_lock(&zl_order_mutex
);
4121 if (strlen((char *)table
->data
) >= NUMA_ZONELIST_ORDER_LEN
) {
4125 strcpy(saved_string
, (char *)table
->data
);
4127 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
4131 int oldval
= user_zonelist_order
;
4133 ret
= __parse_numa_zonelist_order((char *)table
->data
);
4136 * bogus value. restore saved string
4138 strncpy((char *)table
->data
, saved_string
,
4139 NUMA_ZONELIST_ORDER_LEN
);
4140 user_zonelist_order
= oldval
;
4141 } else if (oldval
!= user_zonelist_order
) {
4142 mutex_lock(&zonelists_mutex
);
4143 build_all_zonelists(NULL
, NULL
);
4144 mutex_unlock(&zonelists_mutex
);
4148 mutex_unlock(&zl_order_mutex
);
4153 #define MAX_NODE_LOAD (nr_online_nodes)
4154 static int node_load
[MAX_NUMNODES
];
4157 * find_next_best_node - find the next node that should appear in a given node's fallback list
4158 * @node: node whose fallback list we're appending
4159 * @used_node_mask: nodemask_t of already used nodes
4161 * We use a number of factors to determine which is the next node that should
4162 * appear on a given node's fallback list. The node should not have appeared
4163 * already in @node's fallback list, and it should be the next closest node
4164 * according to the distance array (which contains arbitrary distance values
4165 * from each node to each node in the system), and should also prefer nodes
4166 * with no CPUs, since presumably they'll have very little allocation pressure
4167 * on them otherwise.
4168 * It returns -1 if no node is found.
4170 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
4173 int min_val
= INT_MAX
;
4174 int best_node
= NUMA_NO_NODE
;
4175 const struct cpumask
*tmp
= cpumask_of_node(0);
4177 /* Use the local node if we haven't already */
4178 if (!node_isset(node
, *used_node_mask
)) {
4179 node_set(node
, *used_node_mask
);
4183 for_each_node_state(n
, N_MEMORY
) {
4185 /* Don't want a node to appear more than once */
4186 if (node_isset(n
, *used_node_mask
))
4189 /* Use the distance array to find the distance */
4190 val
= node_distance(node
, n
);
4192 /* Penalize nodes under us ("prefer the next node") */
4195 /* Give preference to headless and unused nodes */
4196 tmp
= cpumask_of_node(n
);
4197 if (!cpumask_empty(tmp
))
4198 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
4200 /* Slight preference for less loaded node */
4201 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
4202 val
+= node_load
[n
];
4204 if (val
< min_val
) {
4211 node_set(best_node
, *used_node_mask
);
4218 * Build zonelists ordered by node and zones within node.
4219 * This results in maximum locality--normal zone overflows into local
4220 * DMA zone, if any--but risks exhausting DMA zone.
4222 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
4225 struct zonelist
*zonelist
;
4227 zonelist
= &pgdat
->node_zonelists
[0];
4228 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
4230 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4231 zonelist
->_zonerefs
[j
].zone
= NULL
;
4232 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4236 * Build gfp_thisnode zonelists
4238 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
4241 struct zonelist
*zonelist
;
4243 zonelist
= &pgdat
->node_zonelists
[1];
4244 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4245 zonelist
->_zonerefs
[j
].zone
= NULL
;
4246 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4250 * Build zonelists ordered by zone and nodes within zones.
4251 * This results in conserving DMA zone[s] until all Normal memory is
4252 * exhausted, but results in overflowing to remote node while memory
4253 * may still exist in local DMA zone.
4255 static int node_order
[MAX_NUMNODES
];
4257 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
4260 int zone_type
; /* needs to be signed */
4262 struct zonelist
*zonelist
;
4264 zonelist
= &pgdat
->node_zonelists
[0];
4266 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
4267 for (j
= 0; j
< nr_nodes
; j
++) {
4268 node
= node_order
[j
];
4269 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
4270 if (populated_zone(z
)) {
4272 &zonelist
->_zonerefs
[pos
++]);
4273 check_highest_zone(zone_type
);
4277 zonelist
->_zonerefs
[pos
].zone
= NULL
;
4278 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
4281 #if defined(CONFIG_64BIT)
4283 * Devices that require DMA32/DMA are relatively rare and do not justify a
4284 * penalty to every machine in case the specialised case applies. Default
4285 * to Node-ordering on 64-bit NUMA machines
4287 static int default_zonelist_order(void)
4289 return ZONELIST_ORDER_NODE
;
4293 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4294 * by the kernel. If processes running on node 0 deplete the low memory zone
4295 * then reclaim will occur more frequency increasing stalls and potentially
4296 * be easier to OOM if a large percentage of the zone is under writeback or
4297 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4298 * Hence, default to zone ordering on 32-bit.
4300 static int default_zonelist_order(void)
4302 return ZONELIST_ORDER_ZONE
;
4304 #endif /* CONFIG_64BIT */
4306 static void set_zonelist_order(void)
4308 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
4309 current_zonelist_order
= default_zonelist_order();
4311 current_zonelist_order
= user_zonelist_order
;
4314 static void build_zonelists(pg_data_t
*pgdat
)
4317 nodemask_t used_mask
;
4318 int local_node
, prev_node
;
4319 struct zonelist
*zonelist
;
4320 unsigned int order
= current_zonelist_order
;
4322 /* initialize zonelists */
4323 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
4324 zonelist
= pgdat
->node_zonelists
+ i
;
4325 zonelist
->_zonerefs
[0].zone
= NULL
;
4326 zonelist
->_zonerefs
[0].zone_idx
= 0;
4329 /* NUMA-aware ordering of nodes */
4330 local_node
= pgdat
->node_id
;
4331 load
= nr_online_nodes
;
4332 prev_node
= local_node
;
4333 nodes_clear(used_mask
);
4335 memset(node_order
, 0, sizeof(node_order
));
4338 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
4340 * We don't want to pressure a particular node.
4341 * So adding penalty to the first node in same
4342 * distance group to make it round-robin.
4344 if (node_distance(local_node
, node
) !=
4345 node_distance(local_node
, prev_node
))
4346 node_load
[node
] = load
;
4350 if (order
== ZONELIST_ORDER_NODE
)
4351 build_zonelists_in_node_order(pgdat
, node
);
4353 node_order
[i
++] = node
; /* remember order */
4356 if (order
== ZONELIST_ORDER_ZONE
) {
4357 /* calculate node order -- i.e., DMA last! */
4358 build_zonelists_in_zone_order(pgdat
, i
);
4361 build_thisnode_zonelists(pgdat
);
4364 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4366 * Return node id of node used for "local" allocations.
4367 * I.e., first node id of first zone in arg node's generic zonelist.
4368 * Used for initializing percpu 'numa_mem', which is used primarily
4369 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4371 int local_memory_node(int node
)
4375 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
4376 gfp_zone(GFP_KERNEL
),
4383 #else /* CONFIG_NUMA */
4385 static void set_zonelist_order(void)
4387 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
4390 static void build_zonelists(pg_data_t
*pgdat
)
4392 int node
, local_node
;
4394 struct zonelist
*zonelist
;
4396 local_node
= pgdat
->node_id
;
4398 zonelist
= &pgdat
->node_zonelists
[0];
4399 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4402 * Now we build the zonelist so that it contains the zones
4403 * of all the other nodes.
4404 * We don't want to pressure a particular node, so when
4405 * building the zones for node N, we make sure that the
4406 * zones coming right after the local ones are those from
4407 * node N+1 (modulo N)
4409 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
4410 if (!node_online(node
))
4412 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4414 for (node
= 0; node
< local_node
; node
++) {
4415 if (!node_online(node
))
4417 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4420 zonelist
->_zonerefs
[j
].zone
= NULL
;
4421 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4424 #endif /* CONFIG_NUMA */
4427 * Boot pageset table. One per cpu which is going to be used for all
4428 * zones and all nodes. The parameters will be set in such a way
4429 * that an item put on a list will immediately be handed over to
4430 * the buddy list. This is safe since pageset manipulation is done
4431 * with interrupts disabled.
4433 * The boot_pagesets must be kept even after bootup is complete for
4434 * unused processors and/or zones. They do play a role for bootstrapping
4435 * hotplugged processors.
4437 * zoneinfo_show() and maybe other functions do
4438 * not check if the processor is online before following the pageset pointer.
4439 * Other parts of the kernel may not check if the zone is available.
4441 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
4442 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
4443 static void setup_zone_pageset(struct zone
*zone
);
4446 * Global mutex to protect against size modification of zonelists
4447 * as well as to serialize pageset setup for the new populated zone.
4449 DEFINE_MUTEX(zonelists_mutex
);
4451 /* return values int ....just for stop_machine() */
4452 static int __build_all_zonelists(void *data
)
4456 pg_data_t
*self
= data
;
4459 memset(node_load
, 0, sizeof(node_load
));
4462 if (self
&& !node_online(self
->node_id
)) {
4463 build_zonelists(self
);
4466 for_each_online_node(nid
) {
4467 pg_data_t
*pgdat
= NODE_DATA(nid
);
4469 build_zonelists(pgdat
);
4473 * Initialize the boot_pagesets that are going to be used
4474 * for bootstrapping processors. The real pagesets for
4475 * each zone will be allocated later when the per cpu
4476 * allocator is available.
4478 * boot_pagesets are used also for bootstrapping offline
4479 * cpus if the system is already booted because the pagesets
4480 * are needed to initialize allocators on a specific cpu too.
4481 * F.e. the percpu allocator needs the page allocator which
4482 * needs the percpu allocator in order to allocate its pagesets
4483 * (a chicken-egg dilemma).
4485 for_each_possible_cpu(cpu
) {
4486 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
4488 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4490 * We now know the "local memory node" for each node--
4491 * i.e., the node of the first zone in the generic zonelist.
4492 * Set up numa_mem percpu variable for on-line cpus. During
4493 * boot, only the boot cpu should be on-line; we'll init the
4494 * secondary cpus' numa_mem as they come on-line. During
4495 * node/memory hotplug, we'll fixup all on-line cpus.
4497 if (cpu_online(cpu
))
4498 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
4505 static noinline
void __init
4506 build_all_zonelists_init(void)
4508 __build_all_zonelists(NULL
);
4509 mminit_verify_zonelist();
4510 cpuset_init_current_mems_allowed();
4514 * Called with zonelists_mutex held always
4515 * unless system_state == SYSTEM_BOOTING.
4517 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4518 * [we're only called with non-NULL zone through __meminit paths] and
4519 * (2) call of __init annotated helper build_all_zonelists_init
4520 * [protected by SYSTEM_BOOTING].
4522 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
4524 set_zonelist_order();
4526 if (system_state
== SYSTEM_BOOTING
) {
4527 build_all_zonelists_init();
4529 #ifdef CONFIG_MEMORY_HOTPLUG
4531 setup_zone_pageset(zone
);
4533 /* we have to stop all cpus to guarantee there is no user
4535 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
4536 /* cpuset refresh routine should be here */
4538 vm_total_pages
= nr_free_pagecache_pages();
4540 * Disable grouping by mobility if the number of pages in the
4541 * system is too low to allow the mechanism to work. It would be
4542 * more accurate, but expensive to check per-zone. This check is
4543 * made on memory-hotadd so a system can start with mobility
4544 * disabled and enable it later
4546 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
4547 page_group_by_mobility_disabled
= 1;
4549 page_group_by_mobility_disabled
= 0;
4551 pr_info("Built %i zonelists in %s order, mobility grouping %s. Total pages: %ld\n",
4553 zonelist_order_name
[current_zonelist_order
],
4554 page_group_by_mobility_disabled
? "off" : "on",
4557 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
4562 * Helper functions to size the waitqueue hash table.
4563 * Essentially these want to choose hash table sizes sufficiently
4564 * large so that collisions trying to wait on pages are rare.
4565 * But in fact, the number of active page waitqueues on typical
4566 * systems is ridiculously low, less than 200. So this is even
4567 * conservative, even though it seems large.
4569 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
4570 * waitqueues, i.e. the size of the waitq table given the number of pages.
4572 #define PAGES_PER_WAITQUEUE 256
4574 #ifndef CONFIG_MEMORY_HOTPLUG
4575 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
4577 unsigned long size
= 1;
4579 pages
/= PAGES_PER_WAITQUEUE
;
4581 while (size
< pages
)
4585 * Once we have dozens or even hundreds of threads sleeping
4586 * on IO we've got bigger problems than wait queue collision.
4587 * Limit the size of the wait table to a reasonable size.
4589 size
= min(size
, 4096UL);
4591 return max(size
, 4UL);
4595 * A zone's size might be changed by hot-add, so it is not possible to determine
4596 * a suitable size for its wait_table. So we use the maximum size now.
4598 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
4600 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
4601 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
4602 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
4604 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
4605 * or more by the traditional way. (See above). It equals:
4607 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
4608 * ia64(16K page size) : = ( 8G + 4M)byte.
4609 * powerpc (64K page size) : = (32G +16M)byte.
4611 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
4618 * This is an integer logarithm so that shifts can be used later
4619 * to extract the more random high bits from the multiplicative
4620 * hash function before the remainder is taken.
4622 static inline unsigned long wait_table_bits(unsigned long size
)
4628 * Initially all pages are reserved - free ones are freed
4629 * up by free_all_bootmem() once the early boot process is
4630 * done. Non-atomic initialization, single-pass.
4632 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
4633 unsigned long start_pfn
, enum memmap_context context
)
4635 struct vmem_altmap
*altmap
= to_vmem_altmap(__pfn_to_phys(start_pfn
));
4636 unsigned long end_pfn
= start_pfn
+ size
;
4637 pg_data_t
*pgdat
= NODE_DATA(nid
);
4639 unsigned long nr_initialised
= 0;
4640 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4641 struct memblock_region
*r
= NULL
, *tmp
;
4644 if (highest_memmap_pfn
< end_pfn
- 1)
4645 highest_memmap_pfn
= end_pfn
- 1;
4648 * Honor reservation requested by the driver for this ZONE_DEVICE
4651 if (altmap
&& start_pfn
== altmap
->base_pfn
)
4652 start_pfn
+= altmap
->reserve
;
4654 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
4656 * There can be holes in boot-time mem_map[]s handed to this
4657 * function. They do not exist on hotplugged memory.
4659 if (context
!= MEMMAP_EARLY
)
4662 if (!early_pfn_valid(pfn
))
4664 if (!early_pfn_in_nid(pfn
, nid
))
4666 if (!update_defer_init(pgdat
, pfn
, end_pfn
, &nr_initialised
))
4669 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4671 * If not mirrored_kernelcore and ZONE_MOVABLE exists, range
4672 * from zone_movable_pfn[nid] to end of each node should be
4673 * ZONE_MOVABLE not ZONE_NORMAL. skip it.
4675 if (!mirrored_kernelcore
&& zone_movable_pfn
[nid
])
4676 if (zone
== ZONE_NORMAL
&& pfn
>= zone_movable_pfn
[nid
])
4680 * Check given memblock attribute by firmware which can affect
4681 * kernel memory layout. If zone==ZONE_MOVABLE but memory is
4682 * mirrored, it's an overlapped memmap init. skip it.
4684 if (mirrored_kernelcore
&& zone
== ZONE_MOVABLE
) {
4685 if (!r
|| pfn
>= memblock_region_memory_end_pfn(r
)) {
4686 for_each_memblock(memory
, tmp
)
4687 if (pfn
< memblock_region_memory_end_pfn(tmp
))
4691 if (pfn
>= memblock_region_memory_base_pfn(r
) &&
4692 memblock_is_mirror(r
)) {
4693 /* already initialized as NORMAL */
4694 pfn
= memblock_region_memory_end_pfn(r
);
4702 * Mark the block movable so that blocks are reserved for
4703 * movable at startup. This will force kernel allocations
4704 * to reserve their blocks rather than leaking throughout
4705 * the address space during boot when many long-lived
4706 * kernel allocations are made.
4708 * bitmap is created for zone's valid pfn range. but memmap
4709 * can be created for invalid pages (for alignment)
4710 * check here not to call set_pageblock_migratetype() against
4713 if (!(pfn
& (pageblock_nr_pages
- 1))) {
4714 struct page
*page
= pfn_to_page(pfn
);
4716 __init_single_page(page
, pfn
, zone
, nid
);
4717 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4719 __init_single_pfn(pfn
, zone
, nid
);
4724 static void __meminit
zone_init_free_lists(struct zone
*zone
)
4726 unsigned int order
, t
;
4727 for_each_migratetype_order(order
, t
) {
4728 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
4729 zone
->free_area
[order
].nr_free
= 0;
4733 #ifndef __HAVE_ARCH_MEMMAP_INIT
4734 #define memmap_init(size, nid, zone, start_pfn) \
4735 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4738 static int zone_batchsize(struct zone
*zone
)
4744 * The per-cpu-pages pools are set to around 1000th of the
4745 * size of the zone. But no more than 1/2 of a meg.
4747 * OK, so we don't know how big the cache is. So guess.
4749 batch
= zone
->managed_pages
/ 1024;
4750 if (batch
* PAGE_SIZE
> 512 * 1024)
4751 batch
= (512 * 1024) / PAGE_SIZE
;
4752 batch
/= 4; /* We effectively *= 4 below */
4757 * Clamp the batch to a 2^n - 1 value. Having a power
4758 * of 2 value was found to be more likely to have
4759 * suboptimal cache aliasing properties in some cases.
4761 * For example if 2 tasks are alternately allocating
4762 * batches of pages, one task can end up with a lot
4763 * of pages of one half of the possible page colors
4764 * and the other with pages of the other colors.
4766 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
4771 /* The deferral and batching of frees should be suppressed under NOMMU
4774 * The problem is that NOMMU needs to be able to allocate large chunks
4775 * of contiguous memory as there's no hardware page translation to
4776 * assemble apparent contiguous memory from discontiguous pages.
4778 * Queueing large contiguous runs of pages for batching, however,
4779 * causes the pages to actually be freed in smaller chunks. As there
4780 * can be a significant delay between the individual batches being
4781 * recycled, this leads to the once large chunks of space being
4782 * fragmented and becoming unavailable for high-order allocations.
4789 * pcp->high and pcp->batch values are related and dependent on one another:
4790 * ->batch must never be higher then ->high.
4791 * The following function updates them in a safe manner without read side
4794 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4795 * those fields changing asynchronously (acording the the above rule).
4797 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4798 * outside of boot time (or some other assurance that no concurrent updaters
4801 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
4802 unsigned long batch
)
4804 /* start with a fail safe value for batch */
4808 /* Update high, then batch, in order */
4815 /* a companion to pageset_set_high() */
4816 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
4818 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
4821 static void pageset_init(struct per_cpu_pageset
*p
)
4823 struct per_cpu_pages
*pcp
;
4826 memset(p
, 0, sizeof(*p
));
4830 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
4831 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
4834 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
4837 pageset_set_batch(p
, batch
);
4841 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4842 * to the value high for the pageset p.
4844 static void pageset_set_high(struct per_cpu_pageset
*p
,
4847 unsigned long batch
= max(1UL, high
/ 4);
4848 if ((high
/ 4) > (PAGE_SHIFT
* 8))
4849 batch
= PAGE_SHIFT
* 8;
4851 pageset_update(&p
->pcp
, high
, batch
);
4854 static void pageset_set_high_and_batch(struct zone
*zone
,
4855 struct per_cpu_pageset
*pcp
)
4857 if (percpu_pagelist_fraction
)
4858 pageset_set_high(pcp
,
4859 (zone
->managed_pages
/
4860 percpu_pagelist_fraction
));
4862 pageset_set_batch(pcp
, zone_batchsize(zone
));
4865 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
4867 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
4870 pageset_set_high_and_batch(zone
, pcp
);
4873 static void __meminit
setup_zone_pageset(struct zone
*zone
)
4876 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
4877 for_each_possible_cpu(cpu
)
4878 zone_pageset_init(zone
, cpu
);
4882 * Allocate per cpu pagesets and initialize them.
4883 * Before this call only boot pagesets were available.
4885 void __init
setup_per_cpu_pageset(void)
4889 for_each_populated_zone(zone
)
4890 setup_zone_pageset(zone
);
4893 static noinline __init_refok
4894 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
4900 * The per-page waitqueue mechanism uses hashed waitqueues
4903 zone
->wait_table_hash_nr_entries
=
4904 wait_table_hash_nr_entries(zone_size_pages
);
4905 zone
->wait_table_bits
=
4906 wait_table_bits(zone
->wait_table_hash_nr_entries
);
4907 alloc_size
= zone
->wait_table_hash_nr_entries
4908 * sizeof(wait_queue_head_t
);
4910 if (!slab_is_available()) {
4911 zone
->wait_table
= (wait_queue_head_t
*)
4912 memblock_virt_alloc_node_nopanic(
4913 alloc_size
, zone
->zone_pgdat
->node_id
);
4916 * This case means that a zone whose size was 0 gets new memory
4917 * via memory hot-add.
4918 * But it may be the case that a new node was hot-added. In
4919 * this case vmalloc() will not be able to use this new node's
4920 * memory - this wait_table must be initialized to use this new
4921 * node itself as well.
4922 * To use this new node's memory, further consideration will be
4925 zone
->wait_table
= vmalloc(alloc_size
);
4927 if (!zone
->wait_table
)
4930 for (i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
4931 init_waitqueue_head(zone
->wait_table
+ i
);
4936 static __meminit
void zone_pcp_init(struct zone
*zone
)
4939 * per cpu subsystem is not up at this point. The following code
4940 * relies on the ability of the linker to provide the
4941 * offset of a (static) per cpu variable into the per cpu area.
4943 zone
->pageset
= &boot_pageset
;
4945 if (populated_zone(zone
))
4946 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
4947 zone
->name
, zone
->present_pages
,
4948 zone_batchsize(zone
));
4951 int __meminit
init_currently_empty_zone(struct zone
*zone
,
4952 unsigned long zone_start_pfn
,
4955 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
4957 ret
= zone_wait_table_init(zone
, size
);
4960 pgdat
->nr_zones
= zone_idx(zone
) + 1;
4962 zone
->zone_start_pfn
= zone_start_pfn
;
4964 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
4965 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4967 (unsigned long)zone_idx(zone
),
4968 zone_start_pfn
, (zone_start_pfn
+ size
));
4970 zone_init_free_lists(zone
);
4975 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4976 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4979 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4981 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
4982 struct mminit_pfnnid_cache
*state
)
4984 unsigned long start_pfn
, end_pfn
;
4987 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
4988 return state
->last_nid
;
4990 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
4992 state
->last_start
= start_pfn
;
4993 state
->last_end
= end_pfn
;
4994 state
->last_nid
= nid
;
4999 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
5002 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
5003 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
5004 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
5006 * If an architecture guarantees that all ranges registered contain no holes
5007 * and may be freed, this this function may be used instead of calling
5008 * memblock_free_early_nid() manually.
5010 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
5012 unsigned long start_pfn
, end_pfn
;
5015 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
5016 start_pfn
= min(start_pfn
, max_low_pfn
);
5017 end_pfn
= min(end_pfn
, max_low_pfn
);
5019 if (start_pfn
< end_pfn
)
5020 memblock_free_early_nid(PFN_PHYS(start_pfn
),
5021 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
5027 * sparse_memory_present_with_active_regions - Call memory_present for each active range
5028 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
5030 * If an architecture guarantees that all ranges registered contain no holes and may
5031 * be freed, this function may be used instead of calling memory_present() manually.
5033 void __init
sparse_memory_present_with_active_regions(int nid
)
5035 unsigned long start_pfn
, end_pfn
;
5038 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
5039 memory_present(this_nid
, start_pfn
, end_pfn
);
5043 * get_pfn_range_for_nid - Return the start and end page frames for a node
5044 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
5045 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5046 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5048 * It returns the start and end page frame of a node based on information
5049 * provided by memblock_set_node(). If called for a node
5050 * with no available memory, a warning is printed and the start and end
5053 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
5054 unsigned long *start_pfn
, unsigned long *end_pfn
)
5056 unsigned long this_start_pfn
, this_end_pfn
;
5062 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
5063 *start_pfn
= min(*start_pfn
, this_start_pfn
);
5064 *end_pfn
= max(*end_pfn
, this_end_pfn
);
5067 if (*start_pfn
== -1UL)
5072 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5073 * assumption is made that zones within a node are ordered in monotonic
5074 * increasing memory addresses so that the "highest" populated zone is used
5076 static void __init
find_usable_zone_for_movable(void)
5079 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
5080 if (zone_index
== ZONE_MOVABLE
)
5083 if (arch_zone_highest_possible_pfn
[zone_index
] >
5084 arch_zone_lowest_possible_pfn
[zone_index
])
5088 VM_BUG_ON(zone_index
== -1);
5089 movable_zone
= zone_index
;
5093 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5094 * because it is sized independent of architecture. Unlike the other zones,
5095 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5096 * in each node depending on the size of each node and how evenly kernelcore
5097 * is distributed. This helper function adjusts the zone ranges
5098 * provided by the architecture for a given node by using the end of the
5099 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5100 * zones within a node are in order of monotonic increases memory addresses
5102 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
5103 unsigned long zone_type
,
5104 unsigned long node_start_pfn
,
5105 unsigned long node_end_pfn
,
5106 unsigned long *zone_start_pfn
,
5107 unsigned long *zone_end_pfn
)
5109 /* Only adjust if ZONE_MOVABLE is on this node */
5110 if (zone_movable_pfn
[nid
]) {
5111 /* Size ZONE_MOVABLE */
5112 if (zone_type
== ZONE_MOVABLE
) {
5113 *zone_start_pfn
= zone_movable_pfn
[nid
];
5114 *zone_end_pfn
= min(node_end_pfn
,
5115 arch_zone_highest_possible_pfn
[movable_zone
]);
5117 /* Check if this whole range is within ZONE_MOVABLE */
5118 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
5119 *zone_start_pfn
= *zone_end_pfn
;
5124 * Return the number of pages a zone spans in a node, including holes
5125 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5127 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5128 unsigned long zone_type
,
5129 unsigned long node_start_pfn
,
5130 unsigned long node_end_pfn
,
5131 unsigned long *zone_start_pfn
,
5132 unsigned long *zone_end_pfn
,
5133 unsigned long *ignored
)
5135 /* When hotadd a new node from cpu_up(), the node should be empty */
5136 if (!node_start_pfn
&& !node_end_pfn
)
5139 /* Get the start and end of the zone */
5140 *zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
5141 *zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
5142 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5143 node_start_pfn
, node_end_pfn
,
5144 zone_start_pfn
, zone_end_pfn
);
5146 /* Check that this node has pages within the zone's required range */
5147 if (*zone_end_pfn
< node_start_pfn
|| *zone_start_pfn
> node_end_pfn
)
5150 /* Move the zone boundaries inside the node if necessary */
5151 *zone_end_pfn
= min(*zone_end_pfn
, node_end_pfn
);
5152 *zone_start_pfn
= max(*zone_start_pfn
, node_start_pfn
);
5154 /* Return the spanned pages */
5155 return *zone_end_pfn
- *zone_start_pfn
;
5159 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5160 * then all holes in the requested range will be accounted for.
5162 unsigned long __meminit
__absent_pages_in_range(int nid
,
5163 unsigned long range_start_pfn
,
5164 unsigned long range_end_pfn
)
5166 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
5167 unsigned long start_pfn
, end_pfn
;
5170 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5171 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
5172 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
5173 nr_absent
-= end_pfn
- start_pfn
;
5179 * absent_pages_in_range - Return number of page frames in holes within a range
5180 * @start_pfn: The start PFN to start searching for holes
5181 * @end_pfn: The end PFN to stop searching for holes
5183 * It returns the number of pages frames in memory holes within a range.
5185 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
5186 unsigned long end_pfn
)
5188 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
5191 /* Return the number of page frames in holes in a zone on a node */
5192 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5193 unsigned long zone_type
,
5194 unsigned long node_start_pfn
,
5195 unsigned long node_end_pfn
,
5196 unsigned long *ignored
)
5198 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
5199 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
5200 unsigned long zone_start_pfn
, zone_end_pfn
;
5201 unsigned long nr_absent
;
5203 /* When hotadd a new node from cpu_up(), the node should be empty */
5204 if (!node_start_pfn
&& !node_end_pfn
)
5207 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
5208 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
5210 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5211 node_start_pfn
, node_end_pfn
,
5212 &zone_start_pfn
, &zone_end_pfn
);
5213 nr_absent
= __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
5216 * ZONE_MOVABLE handling.
5217 * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages
5220 if (zone_movable_pfn
[nid
]) {
5221 if (mirrored_kernelcore
) {
5222 unsigned long start_pfn
, end_pfn
;
5223 struct memblock_region
*r
;
5225 for_each_memblock(memory
, r
) {
5226 start_pfn
= clamp(memblock_region_memory_base_pfn(r
),
5227 zone_start_pfn
, zone_end_pfn
);
5228 end_pfn
= clamp(memblock_region_memory_end_pfn(r
),
5229 zone_start_pfn
, zone_end_pfn
);
5231 if (zone_type
== ZONE_MOVABLE
&&
5232 memblock_is_mirror(r
))
5233 nr_absent
+= end_pfn
- start_pfn
;
5235 if (zone_type
== ZONE_NORMAL
&&
5236 !memblock_is_mirror(r
))
5237 nr_absent
+= end_pfn
- start_pfn
;
5240 if (zone_type
== ZONE_NORMAL
)
5241 nr_absent
+= node_end_pfn
- zone_movable_pfn
[nid
];
5248 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5249 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5250 unsigned long zone_type
,
5251 unsigned long node_start_pfn
,
5252 unsigned long node_end_pfn
,
5253 unsigned long *zone_start_pfn
,
5254 unsigned long *zone_end_pfn
,
5255 unsigned long *zones_size
)
5259 *zone_start_pfn
= node_start_pfn
;
5260 for (zone
= 0; zone
< zone_type
; zone
++)
5261 *zone_start_pfn
+= zones_size
[zone
];
5263 *zone_end_pfn
= *zone_start_pfn
+ zones_size
[zone_type
];
5265 return zones_size
[zone_type
];
5268 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5269 unsigned long zone_type
,
5270 unsigned long node_start_pfn
,
5271 unsigned long node_end_pfn
,
5272 unsigned long *zholes_size
)
5277 return zholes_size
[zone_type
];
5280 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5282 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
5283 unsigned long node_start_pfn
,
5284 unsigned long node_end_pfn
,
5285 unsigned long *zones_size
,
5286 unsigned long *zholes_size
)
5288 unsigned long realtotalpages
= 0, totalpages
= 0;
5291 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5292 struct zone
*zone
= pgdat
->node_zones
+ i
;
5293 unsigned long zone_start_pfn
, zone_end_pfn
;
5294 unsigned long size
, real_size
;
5296 size
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
5302 real_size
= size
- zone_absent_pages_in_node(pgdat
->node_id
, i
,
5303 node_start_pfn
, node_end_pfn
,
5306 zone
->zone_start_pfn
= zone_start_pfn
;
5308 zone
->zone_start_pfn
= 0;
5309 zone
->spanned_pages
= size
;
5310 zone
->present_pages
= real_size
;
5313 realtotalpages
+= real_size
;
5316 pgdat
->node_spanned_pages
= totalpages
;
5317 pgdat
->node_present_pages
= realtotalpages
;
5318 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
5322 #ifndef CONFIG_SPARSEMEM
5324 * Calculate the size of the zone->blockflags rounded to an unsigned long
5325 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5326 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5327 * round what is now in bits to nearest long in bits, then return it in
5330 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
5332 unsigned long usemapsize
;
5334 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
5335 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
5336 usemapsize
= usemapsize
>> pageblock_order
;
5337 usemapsize
*= NR_PAGEBLOCK_BITS
;
5338 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
5340 return usemapsize
/ 8;
5343 static void __init
setup_usemap(struct pglist_data
*pgdat
,
5345 unsigned long zone_start_pfn
,
5346 unsigned long zonesize
)
5348 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
5349 zone
->pageblock_flags
= NULL
;
5351 zone
->pageblock_flags
=
5352 memblock_virt_alloc_node_nopanic(usemapsize
,
5356 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
5357 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
5358 #endif /* CONFIG_SPARSEMEM */
5360 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5362 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5363 void __paginginit
set_pageblock_order(void)
5367 /* Check that pageblock_nr_pages has not already been setup */
5368 if (pageblock_order
)
5371 if (HPAGE_SHIFT
> PAGE_SHIFT
)
5372 order
= HUGETLB_PAGE_ORDER
;
5374 order
= MAX_ORDER
- 1;
5377 * Assume the largest contiguous order of interest is a huge page.
5378 * This value may be variable depending on boot parameters on IA64 and
5381 pageblock_order
= order
;
5383 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5386 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5387 * is unused as pageblock_order is set at compile-time. See
5388 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5391 void __paginginit
set_pageblock_order(void)
5395 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5397 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
5398 unsigned long present_pages
)
5400 unsigned long pages
= spanned_pages
;
5403 * Provide a more accurate estimation if there are holes within
5404 * the zone and SPARSEMEM is in use. If there are holes within the
5405 * zone, each populated memory region may cost us one or two extra
5406 * memmap pages due to alignment because memmap pages for each
5407 * populated regions may not naturally algined on page boundary.
5408 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5410 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
5411 IS_ENABLED(CONFIG_SPARSEMEM
))
5412 pages
= present_pages
;
5414 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
5418 * Set up the zone data structures:
5419 * - mark all pages reserved
5420 * - mark all memory queues empty
5421 * - clear the memory bitmaps
5423 * NOTE: pgdat should get zeroed by caller.
5425 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
)
5428 int nid
= pgdat
->node_id
;
5431 pgdat_resize_init(pgdat
);
5432 #ifdef CONFIG_NUMA_BALANCING
5433 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
5434 pgdat
->numabalancing_migrate_nr_pages
= 0;
5435 pgdat
->numabalancing_migrate_next_window
= jiffies
;
5437 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
5438 spin_lock_init(&pgdat
->split_queue_lock
);
5439 INIT_LIST_HEAD(&pgdat
->split_queue
);
5440 pgdat
->split_queue_len
= 0;
5442 init_waitqueue_head(&pgdat
->kswapd_wait
);
5443 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
5444 #ifdef CONFIG_COMPACTION
5445 init_waitqueue_head(&pgdat
->kcompactd_wait
);
5447 pgdat_page_ext_init(pgdat
);
5449 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5450 struct zone
*zone
= pgdat
->node_zones
+ j
;
5451 unsigned long size
, realsize
, freesize
, memmap_pages
;
5452 unsigned long zone_start_pfn
= zone
->zone_start_pfn
;
5454 size
= zone
->spanned_pages
;
5455 realsize
= freesize
= zone
->present_pages
;
5458 * Adjust freesize so that it accounts for how much memory
5459 * is used by this zone for memmap. This affects the watermark
5460 * and per-cpu initialisations
5462 memmap_pages
= calc_memmap_size(size
, realsize
);
5463 if (!is_highmem_idx(j
)) {
5464 if (freesize
>= memmap_pages
) {
5465 freesize
-= memmap_pages
;
5468 " %s zone: %lu pages used for memmap\n",
5469 zone_names
[j
], memmap_pages
);
5471 pr_warn(" %s zone: %lu pages exceeds freesize %lu\n",
5472 zone_names
[j
], memmap_pages
, freesize
);
5475 /* Account for reserved pages */
5476 if (j
== 0 && freesize
> dma_reserve
) {
5477 freesize
-= dma_reserve
;
5478 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
5479 zone_names
[0], dma_reserve
);
5482 if (!is_highmem_idx(j
))
5483 nr_kernel_pages
+= freesize
;
5484 /* Charge for highmem memmap if there are enough kernel pages */
5485 else if (nr_kernel_pages
> memmap_pages
* 2)
5486 nr_kernel_pages
-= memmap_pages
;
5487 nr_all_pages
+= freesize
;
5490 * Set an approximate value for lowmem here, it will be adjusted
5491 * when the bootmem allocator frees pages into the buddy system.
5492 * And all highmem pages will be managed by the buddy system.
5494 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
5497 zone
->min_unmapped_pages
= (freesize
*sysctl_min_unmapped_ratio
)
5499 zone
->min_slab_pages
= (freesize
* sysctl_min_slab_ratio
) / 100;
5501 zone
->name
= zone_names
[j
];
5502 spin_lock_init(&zone
->lock
);
5503 spin_lock_init(&zone
->lru_lock
);
5504 zone_seqlock_init(zone
);
5505 zone
->zone_pgdat
= pgdat
;
5506 zone_pcp_init(zone
);
5508 /* For bootup, initialized properly in watermark setup */
5509 mod_zone_page_state(zone
, NR_ALLOC_BATCH
, zone
->managed_pages
);
5511 lruvec_init(&zone
->lruvec
);
5515 set_pageblock_order();
5516 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
5517 ret
= init_currently_empty_zone(zone
, zone_start_pfn
, size
);
5519 memmap_init(size
, nid
, j
, zone_start_pfn
);
5523 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
5525 unsigned long __maybe_unused start
= 0;
5526 unsigned long __maybe_unused offset
= 0;
5528 /* Skip empty nodes */
5529 if (!pgdat
->node_spanned_pages
)
5532 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5533 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
5534 offset
= pgdat
->node_start_pfn
- start
;
5535 /* ia64 gets its own node_mem_map, before this, without bootmem */
5536 if (!pgdat
->node_mem_map
) {
5537 unsigned long size
, end
;
5541 * The zone's endpoints aren't required to be MAX_ORDER
5542 * aligned but the node_mem_map endpoints must be in order
5543 * for the buddy allocator to function correctly.
5545 end
= pgdat_end_pfn(pgdat
);
5546 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
5547 size
= (end
- start
) * sizeof(struct page
);
5548 map
= alloc_remap(pgdat
->node_id
, size
);
5550 map
= memblock_virt_alloc_node_nopanic(size
,
5552 pgdat
->node_mem_map
= map
+ offset
;
5554 #ifndef CONFIG_NEED_MULTIPLE_NODES
5556 * With no DISCONTIG, the global mem_map is just set as node 0's
5558 if (pgdat
== NODE_DATA(0)) {
5559 mem_map
= NODE_DATA(0)->node_mem_map
;
5560 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
5561 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
5563 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5566 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
5569 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
5570 unsigned long node_start_pfn
, unsigned long *zholes_size
)
5572 pg_data_t
*pgdat
= NODE_DATA(nid
);
5573 unsigned long start_pfn
= 0;
5574 unsigned long end_pfn
= 0;
5576 /* pg_data_t should be reset to zero when it's allocated */
5577 WARN_ON(pgdat
->nr_zones
|| pgdat
->classzone_idx
);
5579 reset_deferred_meminit(pgdat
);
5580 pgdat
->node_id
= nid
;
5581 pgdat
->node_start_pfn
= node_start_pfn
;
5582 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5583 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
5584 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
5585 (u64
)start_pfn
<< PAGE_SHIFT
,
5586 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
5588 start_pfn
= node_start_pfn
;
5590 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
5591 zones_size
, zholes_size
);
5593 alloc_node_mem_map(pgdat
);
5594 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5595 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
5596 nid
, (unsigned long)pgdat
,
5597 (unsigned long)pgdat
->node_mem_map
);
5600 free_area_init_core(pgdat
);
5603 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5605 #if MAX_NUMNODES > 1
5607 * Figure out the number of possible node ids.
5609 void __init
setup_nr_node_ids(void)
5611 unsigned int highest
;
5613 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
5614 nr_node_ids
= highest
+ 1;
5619 * node_map_pfn_alignment - determine the maximum internode alignment
5621 * This function should be called after node map is populated and sorted.
5622 * It calculates the maximum power of two alignment which can distinguish
5625 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5626 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5627 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5628 * shifted, 1GiB is enough and this function will indicate so.
5630 * This is used to test whether pfn -> nid mapping of the chosen memory
5631 * model has fine enough granularity to avoid incorrect mapping for the
5632 * populated node map.
5634 * Returns the determined alignment in pfn's. 0 if there is no alignment
5635 * requirement (single node).
5637 unsigned long __init
node_map_pfn_alignment(void)
5639 unsigned long accl_mask
= 0, last_end
= 0;
5640 unsigned long start
, end
, mask
;
5644 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
5645 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
5652 * Start with a mask granular enough to pin-point to the
5653 * start pfn and tick off bits one-by-one until it becomes
5654 * too coarse to separate the current node from the last.
5656 mask
= ~((1 << __ffs(start
)) - 1);
5657 while (mask
&& last_end
<= (start
& (mask
<< 1)))
5660 /* accumulate all internode masks */
5664 /* convert mask to number of pages */
5665 return ~accl_mask
+ 1;
5668 /* Find the lowest pfn for a node */
5669 static unsigned long __init
find_min_pfn_for_node(int nid
)
5671 unsigned long min_pfn
= ULONG_MAX
;
5672 unsigned long start_pfn
;
5675 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
5676 min_pfn
= min(min_pfn
, start_pfn
);
5678 if (min_pfn
== ULONG_MAX
) {
5679 pr_warn("Could not find start_pfn for node %d\n", nid
);
5687 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5689 * It returns the minimum PFN based on information provided via
5690 * memblock_set_node().
5692 unsigned long __init
find_min_pfn_with_active_regions(void)
5694 return find_min_pfn_for_node(MAX_NUMNODES
);
5698 * early_calculate_totalpages()
5699 * Sum pages in active regions for movable zone.
5700 * Populate N_MEMORY for calculating usable_nodes.
5702 static unsigned long __init
early_calculate_totalpages(void)
5704 unsigned long totalpages
= 0;
5705 unsigned long start_pfn
, end_pfn
;
5708 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
5709 unsigned long pages
= end_pfn
- start_pfn
;
5711 totalpages
+= pages
;
5713 node_set_state(nid
, N_MEMORY
);
5719 * Find the PFN the Movable zone begins in each node. Kernel memory
5720 * is spread evenly between nodes as long as the nodes have enough
5721 * memory. When they don't, some nodes will have more kernelcore than
5724 static void __init
find_zone_movable_pfns_for_nodes(void)
5727 unsigned long usable_startpfn
;
5728 unsigned long kernelcore_node
, kernelcore_remaining
;
5729 /* save the state before borrow the nodemask */
5730 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
5731 unsigned long totalpages
= early_calculate_totalpages();
5732 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
5733 struct memblock_region
*r
;
5735 /* Need to find movable_zone earlier when movable_node is specified. */
5736 find_usable_zone_for_movable();
5739 * If movable_node is specified, ignore kernelcore and movablecore
5742 if (movable_node_is_enabled()) {
5743 for_each_memblock(memory
, r
) {
5744 if (!memblock_is_hotpluggable(r
))
5749 usable_startpfn
= PFN_DOWN(r
->base
);
5750 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
5751 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
5759 * If kernelcore=mirror is specified, ignore movablecore option
5761 if (mirrored_kernelcore
) {
5762 bool mem_below_4gb_not_mirrored
= false;
5764 for_each_memblock(memory
, r
) {
5765 if (memblock_is_mirror(r
))
5770 usable_startpfn
= memblock_region_memory_base_pfn(r
);
5772 if (usable_startpfn
< 0x100000) {
5773 mem_below_4gb_not_mirrored
= true;
5777 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
5778 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
5782 if (mem_below_4gb_not_mirrored
)
5783 pr_warn("This configuration results in unmirrored kernel memory.");
5789 * If movablecore=nn[KMG] was specified, calculate what size of
5790 * kernelcore that corresponds so that memory usable for
5791 * any allocation type is evenly spread. If both kernelcore
5792 * and movablecore are specified, then the value of kernelcore
5793 * will be used for required_kernelcore if it's greater than
5794 * what movablecore would have allowed.
5796 if (required_movablecore
) {
5797 unsigned long corepages
;
5800 * Round-up so that ZONE_MOVABLE is at least as large as what
5801 * was requested by the user
5803 required_movablecore
=
5804 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
5805 required_movablecore
= min(totalpages
, required_movablecore
);
5806 corepages
= totalpages
- required_movablecore
;
5808 required_kernelcore
= max(required_kernelcore
, corepages
);
5812 * If kernelcore was not specified or kernelcore size is larger
5813 * than totalpages, there is no ZONE_MOVABLE.
5815 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
5818 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5819 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
5822 /* Spread kernelcore memory as evenly as possible throughout nodes */
5823 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5824 for_each_node_state(nid
, N_MEMORY
) {
5825 unsigned long start_pfn
, end_pfn
;
5828 * Recalculate kernelcore_node if the division per node
5829 * now exceeds what is necessary to satisfy the requested
5830 * amount of memory for the kernel
5832 if (required_kernelcore
< kernelcore_node
)
5833 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5836 * As the map is walked, we track how much memory is usable
5837 * by the kernel using kernelcore_remaining. When it is
5838 * 0, the rest of the node is usable by ZONE_MOVABLE
5840 kernelcore_remaining
= kernelcore_node
;
5842 /* Go through each range of PFNs within this node */
5843 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5844 unsigned long size_pages
;
5846 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
5847 if (start_pfn
>= end_pfn
)
5850 /* Account for what is only usable for kernelcore */
5851 if (start_pfn
< usable_startpfn
) {
5852 unsigned long kernel_pages
;
5853 kernel_pages
= min(end_pfn
, usable_startpfn
)
5856 kernelcore_remaining
-= min(kernel_pages
,
5857 kernelcore_remaining
);
5858 required_kernelcore
-= min(kernel_pages
,
5859 required_kernelcore
);
5861 /* Continue if range is now fully accounted */
5862 if (end_pfn
<= usable_startpfn
) {
5865 * Push zone_movable_pfn to the end so
5866 * that if we have to rebalance
5867 * kernelcore across nodes, we will
5868 * not double account here
5870 zone_movable_pfn
[nid
] = end_pfn
;
5873 start_pfn
= usable_startpfn
;
5877 * The usable PFN range for ZONE_MOVABLE is from
5878 * start_pfn->end_pfn. Calculate size_pages as the
5879 * number of pages used as kernelcore
5881 size_pages
= end_pfn
- start_pfn
;
5882 if (size_pages
> kernelcore_remaining
)
5883 size_pages
= kernelcore_remaining
;
5884 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
5887 * Some kernelcore has been met, update counts and
5888 * break if the kernelcore for this node has been
5891 required_kernelcore
-= min(required_kernelcore
,
5893 kernelcore_remaining
-= size_pages
;
5894 if (!kernelcore_remaining
)
5900 * If there is still required_kernelcore, we do another pass with one
5901 * less node in the count. This will push zone_movable_pfn[nid] further
5902 * along on the nodes that still have memory until kernelcore is
5906 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
5910 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5911 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
5912 zone_movable_pfn
[nid
] =
5913 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
5916 /* restore the node_state */
5917 node_states
[N_MEMORY
] = saved_node_state
;
5920 /* Any regular or high memory on that node ? */
5921 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
5923 enum zone_type zone_type
;
5925 if (N_MEMORY
== N_NORMAL_MEMORY
)
5928 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
5929 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
5930 if (populated_zone(zone
)) {
5931 node_set_state(nid
, N_HIGH_MEMORY
);
5932 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
5933 zone_type
<= ZONE_NORMAL
)
5934 node_set_state(nid
, N_NORMAL_MEMORY
);
5941 * free_area_init_nodes - Initialise all pg_data_t and zone data
5942 * @max_zone_pfn: an array of max PFNs for each zone
5944 * This will call free_area_init_node() for each active node in the system.
5945 * Using the page ranges provided by memblock_set_node(), the size of each
5946 * zone in each node and their holes is calculated. If the maximum PFN
5947 * between two adjacent zones match, it is assumed that the zone is empty.
5948 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5949 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5950 * starts where the previous one ended. For example, ZONE_DMA32 starts
5951 * at arch_max_dma_pfn.
5953 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
5955 unsigned long start_pfn
, end_pfn
;
5958 /* Record where the zone boundaries are */
5959 memset(arch_zone_lowest_possible_pfn
, 0,
5960 sizeof(arch_zone_lowest_possible_pfn
));
5961 memset(arch_zone_highest_possible_pfn
, 0,
5962 sizeof(arch_zone_highest_possible_pfn
));
5963 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
5964 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
5965 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
5966 if (i
== ZONE_MOVABLE
)
5968 arch_zone_lowest_possible_pfn
[i
] =
5969 arch_zone_highest_possible_pfn
[i
-1];
5970 arch_zone_highest_possible_pfn
[i
] =
5971 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
5973 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
5974 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
5976 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
5977 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
5978 find_zone_movable_pfns_for_nodes();
5980 /* Print out the zone ranges */
5981 pr_info("Zone ranges:\n");
5982 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5983 if (i
== ZONE_MOVABLE
)
5985 pr_info(" %-8s ", zone_names
[i
]);
5986 if (arch_zone_lowest_possible_pfn
[i
] ==
5987 arch_zone_highest_possible_pfn
[i
])
5990 pr_cont("[mem %#018Lx-%#018Lx]\n",
5991 (u64
)arch_zone_lowest_possible_pfn
[i
]
5993 ((u64
)arch_zone_highest_possible_pfn
[i
]
5994 << PAGE_SHIFT
) - 1);
5997 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5998 pr_info("Movable zone start for each node\n");
5999 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
6000 if (zone_movable_pfn
[i
])
6001 pr_info(" Node %d: %#018Lx\n", i
,
6002 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
6005 /* Print out the early node map */
6006 pr_info("Early memory node ranges\n");
6007 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
6008 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
6009 (u64
)start_pfn
<< PAGE_SHIFT
,
6010 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
6012 /* Initialise every node */
6013 mminit_verify_pageflags_layout();
6014 setup_nr_node_ids();
6015 for_each_online_node(nid
) {
6016 pg_data_t
*pgdat
= NODE_DATA(nid
);
6017 free_area_init_node(nid
, NULL
,
6018 find_min_pfn_for_node(nid
), NULL
);
6020 /* Any memory on that node */
6021 if (pgdat
->node_present_pages
)
6022 node_set_state(nid
, N_MEMORY
);
6023 check_for_memory(pgdat
, nid
);
6027 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
6029 unsigned long long coremem
;
6033 coremem
= memparse(p
, &p
);
6034 *core
= coremem
>> PAGE_SHIFT
;
6036 /* Paranoid check that UL is enough for the coremem value */
6037 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
6043 * kernelcore=size sets the amount of memory for use for allocations that
6044 * cannot be reclaimed or migrated.
6046 static int __init
cmdline_parse_kernelcore(char *p
)
6048 /* parse kernelcore=mirror */
6049 if (parse_option_str(p
, "mirror")) {
6050 mirrored_kernelcore
= true;
6054 return cmdline_parse_core(p
, &required_kernelcore
);
6058 * movablecore=size sets the amount of memory for use for allocations that
6059 * can be reclaimed or migrated.
6061 static int __init
cmdline_parse_movablecore(char *p
)
6063 return cmdline_parse_core(p
, &required_movablecore
);
6066 early_param("kernelcore", cmdline_parse_kernelcore
);
6067 early_param("movablecore", cmdline_parse_movablecore
);
6069 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
6071 void adjust_managed_page_count(struct page
*page
, long count
)
6073 spin_lock(&managed_page_count_lock
);
6074 page_zone(page
)->managed_pages
+= count
;
6075 totalram_pages
+= count
;
6076 #ifdef CONFIG_HIGHMEM
6077 if (PageHighMem(page
))
6078 totalhigh_pages
+= count
;
6080 spin_unlock(&managed_page_count_lock
);
6082 EXPORT_SYMBOL(adjust_managed_page_count
);
6084 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
6087 unsigned long pages
= 0;
6089 start
= (void *)PAGE_ALIGN((unsigned long)start
);
6090 end
= (void *)((unsigned long)end
& PAGE_MASK
);
6091 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
6092 if ((unsigned int)poison
<= 0xFF)
6093 memset(pos
, poison
, PAGE_SIZE
);
6094 free_reserved_page(virt_to_page(pos
));
6098 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
6099 s
, pages
<< (PAGE_SHIFT
- 10), start
, end
);
6103 EXPORT_SYMBOL(free_reserved_area
);
6105 #ifdef CONFIG_HIGHMEM
6106 void free_highmem_page(struct page
*page
)
6108 __free_reserved_page(page
);
6110 page_zone(page
)->managed_pages
++;
6116 void __init
mem_init_print_info(const char *str
)
6118 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
6119 unsigned long init_code_size
, init_data_size
;
6121 physpages
= get_num_physpages();
6122 codesize
= _etext
- _stext
;
6123 datasize
= _edata
- _sdata
;
6124 rosize
= __end_rodata
- __start_rodata
;
6125 bss_size
= __bss_stop
- __bss_start
;
6126 init_data_size
= __init_end
- __init_begin
;
6127 init_code_size
= _einittext
- _sinittext
;
6130 * Detect special cases and adjust section sizes accordingly:
6131 * 1) .init.* may be embedded into .data sections
6132 * 2) .init.text.* may be out of [__init_begin, __init_end],
6133 * please refer to arch/tile/kernel/vmlinux.lds.S.
6134 * 3) .rodata.* may be embedded into .text or .data sections.
6136 #define adj_init_size(start, end, size, pos, adj) \
6138 if (start <= pos && pos < end && size > adj) \
6142 adj_init_size(__init_begin
, __init_end
, init_data_size
,
6143 _sinittext
, init_code_size
);
6144 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
6145 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
6146 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
6147 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
6149 #undef adj_init_size
6151 pr_info("Memory: %luK/%luK available (%luK kernel code, %luK rwdata, %luK rodata, %luK init, %luK bss, %luK reserved, %luK cma-reserved"
6152 #ifdef CONFIG_HIGHMEM
6156 nr_free_pages() << (PAGE_SHIFT
- 10),
6157 physpages
<< (PAGE_SHIFT
- 10),
6158 codesize
>> 10, datasize
>> 10, rosize
>> 10,
6159 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
6160 (physpages
- totalram_pages
- totalcma_pages
) << (PAGE_SHIFT
- 10),
6161 totalcma_pages
<< (PAGE_SHIFT
- 10),
6162 #ifdef CONFIG_HIGHMEM
6163 totalhigh_pages
<< (PAGE_SHIFT
- 10),
6165 str
? ", " : "", str
? str
: "");
6169 * set_dma_reserve - set the specified number of pages reserved in the first zone
6170 * @new_dma_reserve: The number of pages to mark reserved
6172 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6173 * In the DMA zone, a significant percentage may be consumed by kernel image
6174 * and other unfreeable allocations which can skew the watermarks badly. This
6175 * function may optionally be used to account for unfreeable pages in the
6176 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6177 * smaller per-cpu batchsize.
6179 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
6181 dma_reserve
= new_dma_reserve
;
6184 void __init
free_area_init(unsigned long *zones_size
)
6186 free_area_init_node(0, zones_size
,
6187 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
6190 static int page_alloc_cpu_notify(struct notifier_block
*self
,
6191 unsigned long action
, void *hcpu
)
6193 int cpu
= (unsigned long)hcpu
;
6195 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
6196 lru_add_drain_cpu(cpu
);
6200 * Spill the event counters of the dead processor
6201 * into the current processors event counters.
6202 * This artificially elevates the count of the current
6205 vm_events_fold_cpu(cpu
);
6208 * Zero the differential counters of the dead processor
6209 * so that the vm statistics are consistent.
6211 * This is only okay since the processor is dead and cannot
6212 * race with what we are doing.
6214 cpu_vm_stats_fold(cpu
);
6219 void __init
page_alloc_init(void)
6221 hotcpu_notifier(page_alloc_cpu_notify
, 0);
6225 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6226 * or min_free_kbytes changes.
6228 static void calculate_totalreserve_pages(void)
6230 struct pglist_data
*pgdat
;
6231 unsigned long reserve_pages
= 0;
6232 enum zone_type i
, j
;
6234 for_each_online_pgdat(pgdat
) {
6235 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6236 struct zone
*zone
= pgdat
->node_zones
+ i
;
6239 /* Find valid and maximum lowmem_reserve in the zone */
6240 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
6241 if (zone
->lowmem_reserve
[j
] > max
)
6242 max
= zone
->lowmem_reserve
[j
];
6245 /* we treat the high watermark as reserved pages. */
6246 max
+= high_wmark_pages(zone
);
6248 if (max
> zone
->managed_pages
)
6249 max
= zone
->managed_pages
;
6251 zone
->totalreserve_pages
= max
;
6253 reserve_pages
+= max
;
6256 totalreserve_pages
= reserve_pages
;
6260 * setup_per_zone_lowmem_reserve - called whenever
6261 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6262 * has a correct pages reserved value, so an adequate number of
6263 * pages are left in the zone after a successful __alloc_pages().
6265 static void setup_per_zone_lowmem_reserve(void)
6267 struct pglist_data
*pgdat
;
6268 enum zone_type j
, idx
;
6270 for_each_online_pgdat(pgdat
) {
6271 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6272 struct zone
*zone
= pgdat
->node_zones
+ j
;
6273 unsigned long managed_pages
= zone
->managed_pages
;
6275 zone
->lowmem_reserve
[j
] = 0;
6279 struct zone
*lower_zone
;
6283 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
6284 sysctl_lowmem_reserve_ratio
[idx
] = 1;
6286 lower_zone
= pgdat
->node_zones
+ idx
;
6287 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
6288 sysctl_lowmem_reserve_ratio
[idx
];
6289 managed_pages
+= lower_zone
->managed_pages
;
6294 /* update totalreserve_pages */
6295 calculate_totalreserve_pages();
6298 static void __setup_per_zone_wmarks(void)
6300 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
6301 unsigned long lowmem_pages
= 0;
6303 unsigned long flags
;
6305 /* Calculate total number of !ZONE_HIGHMEM pages */
6306 for_each_zone(zone
) {
6307 if (!is_highmem(zone
))
6308 lowmem_pages
+= zone
->managed_pages
;
6311 for_each_zone(zone
) {
6314 spin_lock_irqsave(&zone
->lock
, flags
);
6315 tmp
= (u64
)pages_min
* zone
->managed_pages
;
6316 do_div(tmp
, lowmem_pages
);
6317 if (is_highmem(zone
)) {
6319 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6320 * need highmem pages, so cap pages_min to a small
6323 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6324 * deltas control asynch page reclaim, and so should
6325 * not be capped for highmem.
6327 unsigned long min_pages
;
6329 min_pages
= zone
->managed_pages
/ 1024;
6330 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
6331 zone
->watermark
[WMARK_MIN
] = min_pages
;
6334 * If it's a lowmem zone, reserve a number of pages
6335 * proportionate to the zone's size.
6337 zone
->watermark
[WMARK_MIN
] = tmp
;
6341 * Set the kswapd watermarks distance according to the
6342 * scale factor in proportion to available memory, but
6343 * ensure a minimum size on small systems.
6345 tmp
= max_t(u64
, tmp
>> 2,
6346 mult_frac(zone
->managed_pages
,
6347 watermark_scale_factor
, 10000));
6349 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + tmp
;
6350 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + tmp
* 2;
6352 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
6353 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
6354 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
6356 spin_unlock_irqrestore(&zone
->lock
, flags
);
6359 /* update totalreserve_pages */
6360 calculate_totalreserve_pages();
6364 * setup_per_zone_wmarks - called when min_free_kbytes changes
6365 * or when memory is hot-{added|removed}
6367 * Ensures that the watermark[min,low,high] values for each zone are set
6368 * correctly with respect to min_free_kbytes.
6370 void setup_per_zone_wmarks(void)
6372 mutex_lock(&zonelists_mutex
);
6373 __setup_per_zone_wmarks();
6374 mutex_unlock(&zonelists_mutex
);
6378 * The inactive anon list should be small enough that the VM never has to
6379 * do too much work, but large enough that each inactive page has a chance
6380 * to be referenced again before it is swapped out.
6382 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
6383 * INACTIVE_ANON pages on this zone's LRU, maintained by the
6384 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
6385 * the anonymous pages are kept on the inactive list.
6388 * memory ratio inactive anon
6389 * -------------------------------------
6398 static void __meminit
calculate_zone_inactive_ratio(struct zone
*zone
)
6400 unsigned int gb
, ratio
;
6402 /* Zone size in gigabytes */
6403 gb
= zone
->managed_pages
>> (30 - PAGE_SHIFT
);
6405 ratio
= int_sqrt(10 * gb
);
6409 zone
->inactive_ratio
= ratio
;
6412 static void __meminit
setup_per_zone_inactive_ratio(void)
6417 calculate_zone_inactive_ratio(zone
);
6421 * Initialise min_free_kbytes.
6423 * For small machines we want it small (128k min). For large machines
6424 * we want it large (64MB max). But it is not linear, because network
6425 * bandwidth does not increase linearly with machine size. We use
6427 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6428 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6444 int __meminit
init_per_zone_wmark_min(void)
6446 unsigned long lowmem_kbytes
;
6447 int new_min_free_kbytes
;
6449 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
6450 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
6452 if (new_min_free_kbytes
> user_min_free_kbytes
) {
6453 min_free_kbytes
= new_min_free_kbytes
;
6454 if (min_free_kbytes
< 128)
6455 min_free_kbytes
= 128;
6456 if (min_free_kbytes
> 65536)
6457 min_free_kbytes
= 65536;
6459 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6460 new_min_free_kbytes
, user_min_free_kbytes
);
6462 setup_per_zone_wmarks();
6463 refresh_zone_stat_thresholds();
6464 setup_per_zone_lowmem_reserve();
6465 setup_per_zone_inactive_ratio();
6468 module_init(init_per_zone_wmark_min
)
6471 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6472 * that we can call two helper functions whenever min_free_kbytes
6475 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
6476 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6480 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6485 user_min_free_kbytes
= min_free_kbytes
;
6486 setup_per_zone_wmarks();
6491 int watermark_scale_factor_sysctl_handler(struct ctl_table
*table
, int write
,
6492 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6496 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6501 setup_per_zone_wmarks();
6507 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6508 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6513 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6518 zone
->min_unmapped_pages
= (zone
->managed_pages
*
6519 sysctl_min_unmapped_ratio
) / 100;
6523 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6524 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6529 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6534 zone
->min_slab_pages
= (zone
->managed_pages
*
6535 sysctl_min_slab_ratio
) / 100;
6541 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6542 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6543 * whenever sysctl_lowmem_reserve_ratio changes.
6545 * The reserve ratio obviously has absolutely no relation with the
6546 * minimum watermarks. The lowmem reserve ratio can only make sense
6547 * if in function of the boot time zone sizes.
6549 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6550 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6552 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6553 setup_per_zone_lowmem_reserve();
6558 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6559 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6560 * pagelist can have before it gets flushed back to buddy allocator.
6562 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
6563 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6566 int old_percpu_pagelist_fraction
;
6569 mutex_lock(&pcp_batch_high_lock
);
6570 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
6572 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6573 if (!write
|| ret
< 0)
6576 /* Sanity checking to avoid pcp imbalance */
6577 if (percpu_pagelist_fraction
&&
6578 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
6579 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
6585 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
6588 for_each_populated_zone(zone
) {
6591 for_each_possible_cpu(cpu
)
6592 pageset_set_high_and_batch(zone
,
6593 per_cpu_ptr(zone
->pageset
, cpu
));
6596 mutex_unlock(&pcp_batch_high_lock
);
6601 int hashdist
= HASHDIST_DEFAULT
;
6603 static int __init
set_hashdist(char *str
)
6607 hashdist
= simple_strtoul(str
, &str
, 0);
6610 __setup("hashdist=", set_hashdist
);
6614 * allocate a large system hash table from bootmem
6615 * - it is assumed that the hash table must contain an exact power-of-2
6616 * quantity of entries
6617 * - limit is the number of hash buckets, not the total allocation size
6619 void *__init
alloc_large_system_hash(const char *tablename
,
6620 unsigned long bucketsize
,
6621 unsigned long numentries
,
6624 unsigned int *_hash_shift
,
6625 unsigned int *_hash_mask
,
6626 unsigned long low_limit
,
6627 unsigned long high_limit
)
6629 unsigned long long max
= high_limit
;
6630 unsigned long log2qty
, size
;
6633 /* allow the kernel cmdline to have a say */
6635 /* round applicable memory size up to nearest megabyte */
6636 numentries
= nr_kernel_pages
;
6638 /* It isn't necessary when PAGE_SIZE >= 1MB */
6639 if (PAGE_SHIFT
< 20)
6640 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
6642 /* limit to 1 bucket per 2^scale bytes of low memory */
6643 if (scale
> PAGE_SHIFT
)
6644 numentries
>>= (scale
- PAGE_SHIFT
);
6646 numentries
<<= (PAGE_SHIFT
- scale
);
6648 /* Make sure we've got at least a 0-order allocation.. */
6649 if (unlikely(flags
& HASH_SMALL
)) {
6650 /* Makes no sense without HASH_EARLY */
6651 WARN_ON(!(flags
& HASH_EARLY
));
6652 if (!(numentries
>> *_hash_shift
)) {
6653 numentries
= 1UL << *_hash_shift
;
6654 BUG_ON(!numentries
);
6656 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
6657 numentries
= PAGE_SIZE
/ bucketsize
;
6659 numentries
= roundup_pow_of_two(numentries
);
6661 /* limit allocation size to 1/16 total memory by default */
6663 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
6664 do_div(max
, bucketsize
);
6666 max
= min(max
, 0x80000000ULL
);
6668 if (numentries
< low_limit
)
6669 numentries
= low_limit
;
6670 if (numentries
> max
)
6673 log2qty
= ilog2(numentries
);
6676 size
= bucketsize
<< log2qty
;
6677 if (flags
& HASH_EARLY
)
6678 table
= memblock_virt_alloc_nopanic(size
, 0);
6680 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
6683 * If bucketsize is not a power-of-two, we may free
6684 * some pages at the end of hash table which
6685 * alloc_pages_exact() automatically does
6687 if (get_order(size
) < MAX_ORDER
) {
6688 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
6689 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
6692 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
6695 panic("Failed to allocate %s hash table\n", tablename
);
6697 pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
6698 tablename
, 1UL << log2qty
, ilog2(size
) - PAGE_SHIFT
, size
);
6701 *_hash_shift
= log2qty
;
6703 *_hash_mask
= (1 << log2qty
) - 1;
6708 /* Return a pointer to the bitmap storing bits affecting a block of pages */
6709 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
6712 #ifdef CONFIG_SPARSEMEM
6713 return __pfn_to_section(pfn
)->pageblock_flags
;
6715 return zone
->pageblock_flags
;
6716 #endif /* CONFIG_SPARSEMEM */
6719 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
6721 #ifdef CONFIG_SPARSEMEM
6722 pfn
&= (PAGES_PER_SECTION
-1);
6723 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6725 pfn
= pfn
- round_down(zone
->zone_start_pfn
, pageblock_nr_pages
);
6726 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6727 #endif /* CONFIG_SPARSEMEM */
6731 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
6732 * @page: The page within the block of interest
6733 * @pfn: The target page frame number
6734 * @end_bitidx: The last bit of interest to retrieve
6735 * @mask: mask of bits that the caller is interested in
6737 * Return: pageblock_bits flags
6739 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
6740 unsigned long end_bitidx
,
6744 unsigned long *bitmap
;
6745 unsigned long bitidx
, word_bitidx
;
6748 zone
= page_zone(page
);
6749 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6750 bitidx
= pfn_to_bitidx(zone
, pfn
);
6751 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6752 bitidx
&= (BITS_PER_LONG
-1);
6754 word
= bitmap
[word_bitidx
];
6755 bitidx
+= end_bitidx
;
6756 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
6760 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
6761 * @page: The page within the block of interest
6762 * @flags: The flags to set
6763 * @pfn: The target page frame number
6764 * @end_bitidx: The last bit of interest
6765 * @mask: mask of bits that the caller is interested in
6767 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
6769 unsigned long end_bitidx
,
6773 unsigned long *bitmap
;
6774 unsigned long bitidx
, word_bitidx
;
6775 unsigned long old_word
, word
;
6777 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
6779 zone
= page_zone(page
);
6780 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6781 bitidx
= pfn_to_bitidx(zone
, pfn
);
6782 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6783 bitidx
&= (BITS_PER_LONG
-1);
6785 VM_BUG_ON_PAGE(!zone_spans_pfn(zone
, pfn
), page
);
6787 bitidx
+= end_bitidx
;
6788 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
6789 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
6791 word
= READ_ONCE(bitmap
[word_bitidx
]);
6793 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
6794 if (word
== old_word
)
6801 * This function checks whether pageblock includes unmovable pages or not.
6802 * If @count is not zero, it is okay to include less @count unmovable pages
6804 * PageLRU check without isolation or lru_lock could race so that
6805 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6806 * expect this function should be exact.
6808 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
6809 bool skip_hwpoisoned_pages
)
6811 unsigned long pfn
, iter
, found
;
6815 * For avoiding noise data, lru_add_drain_all() should be called
6816 * If ZONE_MOVABLE, the zone never contains unmovable pages
6818 if (zone_idx(zone
) == ZONE_MOVABLE
)
6820 mt
= get_pageblock_migratetype(page
);
6821 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
6824 pfn
= page_to_pfn(page
);
6825 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
6826 unsigned long check
= pfn
+ iter
;
6828 if (!pfn_valid_within(check
))
6831 page
= pfn_to_page(check
);
6834 * Hugepages are not in LRU lists, but they're movable.
6835 * We need not scan over tail pages bacause we don't
6836 * handle each tail page individually in migration.
6838 if (PageHuge(page
)) {
6839 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
6844 * We can't use page_count without pin a page
6845 * because another CPU can free compound page.
6846 * This check already skips compound tails of THP
6847 * because their page->_count is zero at all time.
6849 if (!page_ref_count(page
)) {
6850 if (PageBuddy(page
))
6851 iter
+= (1 << page_order(page
)) - 1;
6856 * The HWPoisoned page may be not in buddy system, and
6857 * page_count() is not 0.
6859 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
6865 * If there are RECLAIMABLE pages, we need to check
6866 * it. But now, memory offline itself doesn't call
6867 * shrink_node_slabs() and it still to be fixed.
6870 * If the page is not RAM, page_count()should be 0.
6871 * we don't need more check. This is an _used_ not-movable page.
6873 * The problematic thing here is PG_reserved pages. PG_reserved
6874 * is set to both of a memory hole page and a _used_ kernel
6883 bool is_pageblock_removable_nolock(struct page
*page
)
6889 * We have to be careful here because we are iterating over memory
6890 * sections which are not zone aware so we might end up outside of
6891 * the zone but still within the section.
6892 * We have to take care about the node as well. If the node is offline
6893 * its NODE_DATA will be NULL - see page_zone.
6895 if (!node_online(page_to_nid(page
)))
6898 zone
= page_zone(page
);
6899 pfn
= page_to_pfn(page
);
6900 if (!zone_spans_pfn(zone
, pfn
))
6903 return !has_unmovable_pages(zone
, page
, 0, true);
6906 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
6908 static unsigned long pfn_max_align_down(unsigned long pfn
)
6910 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6911 pageblock_nr_pages
) - 1);
6914 static unsigned long pfn_max_align_up(unsigned long pfn
)
6916 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6917 pageblock_nr_pages
));
6920 /* [start, end) must belong to a single zone. */
6921 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
6922 unsigned long start
, unsigned long end
)
6924 /* This function is based on compact_zone() from compaction.c. */
6925 unsigned long nr_reclaimed
;
6926 unsigned long pfn
= start
;
6927 unsigned int tries
= 0;
6932 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
6933 if (fatal_signal_pending(current
)) {
6938 if (list_empty(&cc
->migratepages
)) {
6939 cc
->nr_migratepages
= 0;
6940 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
6946 } else if (++tries
== 5) {
6947 ret
= ret
< 0 ? ret
: -EBUSY
;
6951 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
6953 cc
->nr_migratepages
-= nr_reclaimed
;
6955 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
6956 NULL
, 0, cc
->mode
, MR_CMA
);
6959 putback_movable_pages(&cc
->migratepages
);
6966 * alloc_contig_range() -- tries to allocate given range of pages
6967 * @start: start PFN to allocate
6968 * @end: one-past-the-last PFN to allocate
6969 * @migratetype: migratetype of the underlaying pageblocks (either
6970 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
6971 * in range must have the same migratetype and it must
6972 * be either of the two.
6974 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
6975 * aligned, however it's the caller's responsibility to guarantee that
6976 * we are the only thread that changes migrate type of pageblocks the
6979 * The PFN range must belong to a single zone.
6981 * Returns zero on success or negative error code. On success all
6982 * pages which PFN is in [start, end) are allocated for the caller and
6983 * need to be freed with free_contig_range().
6985 int alloc_contig_range(unsigned long start
, unsigned long end
,
6986 unsigned migratetype
)
6988 unsigned long outer_start
, outer_end
;
6992 struct compact_control cc
= {
6993 .nr_migratepages
= 0,
6995 .zone
= page_zone(pfn_to_page(start
)),
6996 .mode
= MIGRATE_SYNC
,
6997 .ignore_skip_hint
= true,
6999 INIT_LIST_HEAD(&cc
.migratepages
);
7002 * What we do here is we mark all pageblocks in range as
7003 * MIGRATE_ISOLATE. Because pageblock and max order pages may
7004 * have different sizes, and due to the way page allocator
7005 * work, we align the range to biggest of the two pages so
7006 * that page allocator won't try to merge buddies from
7007 * different pageblocks and change MIGRATE_ISOLATE to some
7008 * other migration type.
7010 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
7011 * migrate the pages from an unaligned range (ie. pages that
7012 * we are interested in). This will put all the pages in
7013 * range back to page allocator as MIGRATE_ISOLATE.
7015 * When this is done, we take the pages in range from page
7016 * allocator removing them from the buddy system. This way
7017 * page allocator will never consider using them.
7019 * This lets us mark the pageblocks back as
7020 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
7021 * aligned range but not in the unaligned, original range are
7022 * put back to page allocator so that buddy can use them.
7025 ret
= start_isolate_page_range(pfn_max_align_down(start
),
7026 pfn_max_align_up(end
), migratetype
,
7032 * In case of -EBUSY, we'd like to know which page causes problem.
7033 * So, just fall through. We will check it in test_pages_isolated().
7035 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
7036 if (ret
&& ret
!= -EBUSY
)
7040 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
7041 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
7042 * more, all pages in [start, end) are free in page allocator.
7043 * What we are going to do is to allocate all pages from
7044 * [start, end) (that is remove them from page allocator).
7046 * The only problem is that pages at the beginning and at the
7047 * end of interesting range may be not aligned with pages that
7048 * page allocator holds, ie. they can be part of higher order
7049 * pages. Because of this, we reserve the bigger range and
7050 * once this is done free the pages we are not interested in.
7052 * We don't have to hold zone->lock here because the pages are
7053 * isolated thus they won't get removed from buddy.
7056 lru_add_drain_all();
7057 drain_all_pages(cc
.zone
);
7060 outer_start
= start
;
7061 while (!PageBuddy(pfn_to_page(outer_start
))) {
7062 if (++order
>= MAX_ORDER
) {
7063 outer_start
= start
;
7066 outer_start
&= ~0UL << order
;
7069 if (outer_start
!= start
) {
7070 order
= page_order(pfn_to_page(outer_start
));
7073 * outer_start page could be small order buddy page and
7074 * it doesn't include start page. Adjust outer_start
7075 * in this case to report failed page properly
7076 * on tracepoint in test_pages_isolated()
7078 if (outer_start
+ (1UL << order
) <= start
)
7079 outer_start
= start
;
7082 /* Make sure the range is really isolated. */
7083 if (test_pages_isolated(outer_start
, end
, false)) {
7084 pr_info("%s: [%lx, %lx) PFNs busy\n",
7085 __func__
, outer_start
, end
);
7090 /* Grab isolated pages from freelists. */
7091 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
7097 /* Free head and tail (if any) */
7098 if (start
!= outer_start
)
7099 free_contig_range(outer_start
, start
- outer_start
);
7100 if (end
!= outer_end
)
7101 free_contig_range(end
, outer_end
- end
);
7104 undo_isolate_page_range(pfn_max_align_down(start
),
7105 pfn_max_align_up(end
), migratetype
);
7109 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
7111 unsigned int count
= 0;
7113 for (; nr_pages
--; pfn
++) {
7114 struct page
*page
= pfn_to_page(pfn
);
7116 count
+= page_count(page
) != 1;
7119 WARN(count
!= 0, "%d pages are still in use!\n", count
);
7123 #ifdef CONFIG_MEMORY_HOTPLUG
7125 * The zone indicated has a new number of managed_pages; batch sizes and percpu
7126 * page high values need to be recalulated.
7128 void __meminit
zone_pcp_update(struct zone
*zone
)
7131 mutex_lock(&pcp_batch_high_lock
);
7132 for_each_possible_cpu(cpu
)
7133 pageset_set_high_and_batch(zone
,
7134 per_cpu_ptr(zone
->pageset
, cpu
));
7135 mutex_unlock(&pcp_batch_high_lock
);
7139 void zone_pcp_reset(struct zone
*zone
)
7141 unsigned long flags
;
7143 struct per_cpu_pageset
*pset
;
7145 /* avoid races with drain_pages() */
7146 local_irq_save(flags
);
7147 if (zone
->pageset
!= &boot_pageset
) {
7148 for_each_online_cpu(cpu
) {
7149 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
7150 drain_zonestat(zone
, pset
);
7152 free_percpu(zone
->pageset
);
7153 zone
->pageset
= &boot_pageset
;
7155 local_irq_restore(flags
);
7158 #ifdef CONFIG_MEMORY_HOTREMOVE
7160 * All pages in the range must be isolated before calling this.
7163 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
7167 unsigned int order
, i
;
7169 unsigned long flags
;
7170 /* find the first valid pfn */
7171 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
7176 zone
= page_zone(pfn_to_page(pfn
));
7177 spin_lock_irqsave(&zone
->lock
, flags
);
7179 while (pfn
< end_pfn
) {
7180 if (!pfn_valid(pfn
)) {
7184 page
= pfn_to_page(pfn
);
7186 * The HWPoisoned page may be not in buddy system, and
7187 * page_count() is not 0.
7189 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
7191 SetPageReserved(page
);
7195 BUG_ON(page_count(page
));
7196 BUG_ON(!PageBuddy(page
));
7197 order
= page_order(page
);
7198 #ifdef CONFIG_DEBUG_VM
7199 pr_info("remove from free list %lx %d %lx\n",
7200 pfn
, 1 << order
, end_pfn
);
7202 list_del(&page
->lru
);
7203 rmv_page_order(page
);
7204 zone
->free_area
[order
].nr_free
--;
7205 for (i
= 0; i
< (1 << order
); i
++)
7206 SetPageReserved((page
+i
));
7207 pfn
+= (1 << order
);
7209 spin_unlock_irqrestore(&zone
->lock
, flags
);
7213 bool is_free_buddy_page(struct page
*page
)
7215 struct zone
*zone
= page_zone(page
);
7216 unsigned long pfn
= page_to_pfn(page
);
7217 unsigned long flags
;
7220 spin_lock_irqsave(&zone
->lock
, flags
);
7221 for (order
= 0; order
< MAX_ORDER
; order
++) {
7222 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
7224 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
7227 spin_unlock_irqrestore(&zone
->lock
, flags
);
7229 return order
< MAX_ORDER
;