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/stop_machine.h>
47 #include <linux/sort.h>
48 #include <linux/pfn.h>
49 #include <linux/backing-dev.h>
50 #include <linux/fault-inject.h>
51 #include <linux/page-isolation.h>
52 #include <linux/page_ext.h>
53 #include <linux/debugobjects.h>
54 #include <linux/kmemleak.h>
55 #include <linux/compaction.h>
56 #include <trace/events/kmem.h>
57 #include <linux/prefetch.h>
58 #include <linux/mm_inline.h>
59 #include <linux/migrate.h>
60 #include <linux/page_ext.h>
61 #include <linux/hugetlb.h>
62 #include <linux/sched/rt.h>
63 #include <linux/page_owner.h>
64 #include <linux/kthread.h>
66 #include <asm/sections.h>
67 #include <asm/tlbflush.h>
68 #include <asm/div64.h>
71 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
72 static DEFINE_MUTEX(pcp_batch_high_lock
);
73 #define MIN_PERCPU_PAGELIST_FRACTION (8)
75 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
76 DEFINE_PER_CPU(int, numa_node
);
77 EXPORT_PER_CPU_SYMBOL(numa_node
);
80 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
82 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
83 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
84 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
85 * defined in <linux/topology.h>.
87 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
88 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
89 int _node_numa_mem_
[MAX_NUMNODES
];
93 * Array of node states.
95 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
96 [N_POSSIBLE
] = NODE_MASK_ALL
,
97 [N_ONLINE
] = { { [0] = 1UL } },
99 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
100 #ifdef CONFIG_HIGHMEM
101 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
103 #ifdef CONFIG_MOVABLE_NODE
104 [N_MEMORY
] = { { [0] = 1UL } },
106 [N_CPU
] = { { [0] = 1UL } },
109 EXPORT_SYMBOL(node_states
);
111 /* Protect totalram_pages and zone->managed_pages */
112 static DEFINE_SPINLOCK(managed_page_count_lock
);
114 unsigned long totalram_pages __read_mostly
;
115 unsigned long totalreserve_pages __read_mostly
;
116 unsigned long totalcma_pages __read_mostly
;
118 int percpu_pagelist_fraction
;
119 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
122 * A cached value of the page's pageblock's migratetype, used when the page is
123 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
124 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
125 * Also the migratetype set in the page does not necessarily match the pcplist
126 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
127 * other index - this ensures that it will be put on the correct CMA freelist.
129 static inline int get_pcppage_migratetype(struct page
*page
)
134 static inline void set_pcppage_migratetype(struct page
*page
, int migratetype
)
136 page
->index
= migratetype
;
139 #ifdef CONFIG_PM_SLEEP
141 * The following functions are used by the suspend/hibernate code to temporarily
142 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
143 * while devices are suspended. To avoid races with the suspend/hibernate code,
144 * they should always be called with pm_mutex held (gfp_allowed_mask also should
145 * only be modified with pm_mutex held, unless the suspend/hibernate code is
146 * guaranteed not to run in parallel with that modification).
149 static gfp_t saved_gfp_mask
;
151 void pm_restore_gfp_mask(void)
153 WARN_ON(!mutex_is_locked(&pm_mutex
));
154 if (saved_gfp_mask
) {
155 gfp_allowed_mask
= saved_gfp_mask
;
160 void pm_restrict_gfp_mask(void)
162 WARN_ON(!mutex_is_locked(&pm_mutex
));
163 WARN_ON(saved_gfp_mask
);
164 saved_gfp_mask
= gfp_allowed_mask
;
165 gfp_allowed_mask
&= ~(__GFP_IO
| __GFP_FS
);
168 bool pm_suspended_storage(void)
170 if ((gfp_allowed_mask
& (__GFP_IO
| __GFP_FS
)) == (__GFP_IO
| __GFP_FS
))
174 #endif /* CONFIG_PM_SLEEP */
176 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
177 unsigned int pageblock_order __read_mostly
;
180 static void __free_pages_ok(struct page
*page
, unsigned int order
);
183 * results with 256, 32 in the lowmem_reserve sysctl:
184 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
185 * 1G machine -> (16M dma, 784M normal, 224M high)
186 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
187 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
188 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
190 * TBD: should special case ZONE_DMA32 machines here - in those we normally
191 * don't need any ZONE_NORMAL reservation
193 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
194 #ifdef CONFIG_ZONE_DMA
197 #ifdef CONFIG_ZONE_DMA32
200 #ifdef CONFIG_HIGHMEM
206 EXPORT_SYMBOL(totalram_pages
);
208 static char * const zone_names
[MAX_NR_ZONES
] = {
209 #ifdef CONFIG_ZONE_DMA
212 #ifdef CONFIG_ZONE_DMA32
216 #ifdef CONFIG_HIGHMEM
220 #ifdef CONFIG_ZONE_DEVICE
225 compound_page_dtor
* const compound_page_dtors
[] = {
228 #ifdef CONFIG_HUGETLB_PAGE
231 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
236 int min_free_kbytes
= 1024;
237 int user_min_free_kbytes
= -1;
239 static unsigned long __meminitdata nr_kernel_pages
;
240 static unsigned long __meminitdata nr_all_pages
;
241 static unsigned long __meminitdata dma_reserve
;
243 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
244 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
245 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
246 static unsigned long __initdata required_kernelcore
;
247 static unsigned long __initdata required_movablecore
;
248 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
250 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
252 EXPORT_SYMBOL(movable_zone
);
253 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
256 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
257 int nr_online_nodes __read_mostly
= 1;
258 EXPORT_SYMBOL(nr_node_ids
);
259 EXPORT_SYMBOL(nr_online_nodes
);
262 int page_group_by_mobility_disabled __read_mostly
;
264 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
265 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
267 pgdat
->first_deferred_pfn
= ULONG_MAX
;
270 /* Returns true if the struct page for the pfn is uninitialised */
271 static inline bool __meminit
early_page_uninitialised(unsigned long pfn
)
273 if (pfn
>= NODE_DATA(early_pfn_to_nid(pfn
))->first_deferred_pfn
)
279 static inline bool early_page_nid_uninitialised(unsigned long pfn
, int nid
)
281 if (pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
288 * Returns false when the remaining initialisation should be deferred until
289 * later in the boot cycle when it can be parallelised.
291 static inline bool update_defer_init(pg_data_t
*pgdat
,
292 unsigned long pfn
, unsigned long zone_end
,
293 unsigned long *nr_initialised
)
295 /* Always populate low zones for address-contrained allocations */
296 if (zone_end
< pgdat_end_pfn(pgdat
))
299 /* Initialise at least 2G of the highest zone */
301 if (*nr_initialised
> (2UL << (30 - PAGE_SHIFT
)) &&
302 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
303 pgdat
->first_deferred_pfn
= pfn
;
310 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
314 static inline bool early_page_uninitialised(unsigned long pfn
)
319 static inline bool early_page_nid_uninitialised(unsigned long pfn
, int nid
)
324 static inline bool update_defer_init(pg_data_t
*pgdat
,
325 unsigned long pfn
, unsigned long zone_end
,
326 unsigned long *nr_initialised
)
333 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
335 if (unlikely(page_group_by_mobility_disabled
&&
336 migratetype
< MIGRATE_PCPTYPES
))
337 migratetype
= MIGRATE_UNMOVABLE
;
339 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
340 PB_migrate
, PB_migrate_end
);
343 #ifdef CONFIG_DEBUG_VM
344 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
348 unsigned long pfn
= page_to_pfn(page
);
349 unsigned long sp
, start_pfn
;
352 seq
= zone_span_seqbegin(zone
);
353 start_pfn
= zone
->zone_start_pfn
;
354 sp
= zone
->spanned_pages
;
355 if (!zone_spans_pfn(zone
, pfn
))
357 } while (zone_span_seqretry(zone
, seq
));
360 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
361 pfn
, zone_to_nid(zone
), zone
->name
,
362 start_pfn
, start_pfn
+ sp
);
367 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
369 if (!pfn_valid_within(page_to_pfn(page
)))
371 if (zone
!= page_zone(page
))
377 * Temporary debugging check for pages not lying within a given zone.
379 static int bad_range(struct zone
*zone
, struct page
*page
)
381 if (page_outside_zone_boundaries(zone
, page
))
383 if (!page_is_consistent(zone
, page
))
389 static inline int bad_range(struct zone
*zone
, struct page
*page
)
395 static void bad_page(struct page
*page
, const char *reason
,
396 unsigned long bad_flags
)
398 static unsigned long resume
;
399 static unsigned long nr_shown
;
400 static unsigned long nr_unshown
;
402 /* Don't complain about poisoned pages */
403 if (PageHWPoison(page
)) {
404 page_mapcount_reset(page
); /* remove PageBuddy */
409 * Allow a burst of 60 reports, then keep quiet for that minute;
410 * or allow a steady drip of one report per second.
412 if (nr_shown
== 60) {
413 if (time_before(jiffies
, resume
)) {
419 "BUG: Bad page state: %lu messages suppressed\n",
426 resume
= jiffies
+ 60 * HZ
;
428 printk(KERN_ALERT
"BUG: Bad page state in process %s pfn:%05lx\n",
429 current
->comm
, page_to_pfn(page
));
430 dump_page_badflags(page
, reason
, bad_flags
);
435 /* Leave bad fields for debug, except PageBuddy could make trouble */
436 page_mapcount_reset(page
); /* remove PageBuddy */
437 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
441 * Higher-order pages are called "compound pages". They are structured thusly:
443 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
445 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
446 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
448 * The first tail page's ->compound_dtor holds the offset in array of compound
449 * page destructors. See compound_page_dtors.
451 * The first tail page's ->compound_order holds the order of allocation.
452 * This usage means that zero-order pages may not be compound.
455 void free_compound_page(struct page
*page
)
457 __free_pages_ok(page
, compound_order(page
));
460 void prep_compound_page(struct page
*page
, unsigned int order
)
463 int nr_pages
= 1 << order
;
465 set_compound_page_dtor(page
, COMPOUND_PAGE_DTOR
);
466 set_compound_order(page
, order
);
468 for (i
= 1; i
< nr_pages
; i
++) {
469 struct page
*p
= page
+ i
;
470 set_page_count(p
, 0);
471 p
->mapping
= TAIL_MAPPING
;
472 set_compound_head(p
, page
);
474 atomic_set(compound_mapcount_ptr(page
), -1);
477 #ifdef CONFIG_DEBUG_PAGEALLOC
478 unsigned int _debug_guardpage_minorder
;
479 bool _debug_pagealloc_enabled __read_mostly
;
480 bool _debug_guardpage_enabled __read_mostly
;
482 static int __init
early_debug_pagealloc(char *buf
)
487 if (strcmp(buf
, "on") == 0)
488 _debug_pagealloc_enabled
= true;
492 early_param("debug_pagealloc", early_debug_pagealloc
);
494 static bool need_debug_guardpage(void)
496 /* If we don't use debug_pagealloc, we don't need guard page */
497 if (!debug_pagealloc_enabled())
503 static void init_debug_guardpage(void)
505 if (!debug_pagealloc_enabled())
508 _debug_guardpage_enabled
= true;
511 struct page_ext_operations debug_guardpage_ops
= {
512 .need
= need_debug_guardpage
,
513 .init
= init_debug_guardpage
,
516 static int __init
debug_guardpage_minorder_setup(char *buf
)
520 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
521 printk(KERN_ERR
"Bad debug_guardpage_minorder value\n");
524 _debug_guardpage_minorder
= res
;
525 printk(KERN_INFO
"Setting debug_guardpage_minorder to %lu\n", res
);
528 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
530 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
531 unsigned int order
, int migratetype
)
533 struct page_ext
*page_ext
;
535 if (!debug_guardpage_enabled())
538 page_ext
= lookup_page_ext(page
);
539 __set_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
541 INIT_LIST_HEAD(&page
->lru
);
542 set_page_private(page
, order
);
543 /* Guard pages are not available for any usage */
544 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
547 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
548 unsigned int order
, int migratetype
)
550 struct page_ext
*page_ext
;
552 if (!debug_guardpage_enabled())
555 page_ext
= lookup_page_ext(page
);
556 __clear_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
558 set_page_private(page
, 0);
559 if (!is_migrate_isolate(migratetype
))
560 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
563 struct page_ext_operations debug_guardpage_ops
= { NULL
, };
564 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
565 unsigned int order
, int migratetype
) {}
566 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
567 unsigned int order
, int migratetype
) {}
570 static inline void set_page_order(struct page
*page
, unsigned int order
)
572 set_page_private(page
, order
);
573 __SetPageBuddy(page
);
576 static inline void rmv_page_order(struct page
*page
)
578 __ClearPageBuddy(page
);
579 set_page_private(page
, 0);
583 * This function checks whether a page is free && is the buddy
584 * we can do coalesce a page and its buddy if
585 * (a) the buddy is not in a hole &&
586 * (b) the buddy is in the buddy system &&
587 * (c) a page and its buddy have the same order &&
588 * (d) a page and its buddy are in the same zone.
590 * For recording whether a page is in the buddy system, we set ->_mapcount
591 * PAGE_BUDDY_MAPCOUNT_VALUE.
592 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
593 * serialized by zone->lock.
595 * For recording page's order, we use page_private(page).
597 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
600 if (!pfn_valid_within(page_to_pfn(buddy
)))
603 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
604 if (page_zone_id(page
) != page_zone_id(buddy
))
607 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
612 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
614 * zone check is done late to avoid uselessly
615 * calculating zone/node ids for pages that could
618 if (page_zone_id(page
) != page_zone_id(buddy
))
621 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
629 * Freeing function for a buddy system allocator.
631 * The concept of a buddy system is to maintain direct-mapped table
632 * (containing bit values) for memory blocks of various "orders".
633 * The bottom level table contains the map for the smallest allocatable
634 * units of memory (here, pages), and each level above it describes
635 * pairs of units from the levels below, hence, "buddies".
636 * At a high level, all that happens here is marking the table entry
637 * at the bottom level available, and propagating the changes upward
638 * as necessary, plus some accounting needed to play nicely with other
639 * parts of the VM system.
640 * At each level, we keep a list of pages, which are heads of continuous
641 * free pages of length of (1 << order) and marked with _mapcount
642 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
644 * So when we are allocating or freeing one, we can derive the state of the
645 * other. That is, if we allocate a small block, and both were
646 * free, the remainder of the region must be split into blocks.
647 * If a block is freed, and its buddy is also free, then this
648 * triggers coalescing into a block of larger size.
653 static inline void __free_one_page(struct page
*page
,
655 struct zone
*zone
, unsigned int order
,
658 unsigned long page_idx
;
659 unsigned long combined_idx
;
660 unsigned long uninitialized_var(buddy_idx
);
662 unsigned int max_order
= MAX_ORDER
;
664 VM_BUG_ON(!zone_is_initialized(zone
));
665 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
667 VM_BUG_ON(migratetype
== -1);
668 if (is_migrate_isolate(migratetype
)) {
670 * We restrict max order of merging to prevent merge
671 * between freepages on isolate pageblock and normal
672 * pageblock. Without this, pageblock isolation
673 * could cause incorrect freepage accounting.
675 max_order
= min_t(unsigned int, MAX_ORDER
, pageblock_order
+ 1);
677 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
680 page_idx
= pfn
& ((1 << max_order
) - 1);
682 VM_BUG_ON_PAGE(page_idx
& ((1 << order
) - 1), page
);
683 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
685 while (order
< max_order
- 1) {
686 buddy_idx
= __find_buddy_index(page_idx
, order
);
687 buddy
= page
+ (buddy_idx
- page_idx
);
688 if (!page_is_buddy(page
, buddy
, order
))
691 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
692 * merge with it and move up one order.
694 if (page_is_guard(buddy
)) {
695 clear_page_guard(zone
, buddy
, order
, migratetype
);
697 list_del(&buddy
->lru
);
698 zone
->free_area
[order
].nr_free
--;
699 rmv_page_order(buddy
);
701 combined_idx
= buddy_idx
& page_idx
;
702 page
= page
+ (combined_idx
- page_idx
);
703 page_idx
= combined_idx
;
706 set_page_order(page
, order
);
709 * If this is not the largest possible page, check if the buddy
710 * of the next-highest order is free. If it is, it's possible
711 * that pages are being freed that will coalesce soon. In case,
712 * that is happening, add the free page to the tail of the list
713 * so it's less likely to be used soon and more likely to be merged
714 * as a higher order page
716 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
717 struct page
*higher_page
, *higher_buddy
;
718 combined_idx
= buddy_idx
& page_idx
;
719 higher_page
= page
+ (combined_idx
- page_idx
);
720 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
721 higher_buddy
= higher_page
+ (buddy_idx
- combined_idx
);
722 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
723 list_add_tail(&page
->lru
,
724 &zone
->free_area
[order
].free_list
[migratetype
]);
729 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
731 zone
->free_area
[order
].nr_free
++;
734 static inline int free_pages_check(struct page
*page
)
736 const char *bad_reason
= NULL
;
737 unsigned long bad_flags
= 0;
739 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
740 bad_reason
= "nonzero mapcount";
741 if (unlikely(page
->mapping
!= NULL
))
742 bad_reason
= "non-NULL mapping";
743 if (unlikely(atomic_read(&page
->_count
) != 0))
744 bad_reason
= "nonzero _count";
745 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
746 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
747 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
750 if (unlikely(page
->mem_cgroup
))
751 bad_reason
= "page still charged to cgroup";
753 if (unlikely(bad_reason
)) {
754 bad_page(page
, bad_reason
, bad_flags
);
757 page_cpupid_reset_last(page
);
758 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
759 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
764 * Frees a number of pages from the PCP lists
765 * Assumes all pages on list are in same zone, and of same order.
766 * count is the number of pages to free.
768 * If the zone was previously in an "all pages pinned" state then look to
769 * see if this freeing clears that state.
771 * And clear the zone's pages_scanned counter, to hold off the "all pages are
772 * pinned" detection logic.
774 static void free_pcppages_bulk(struct zone
*zone
, int count
,
775 struct per_cpu_pages
*pcp
)
780 unsigned long nr_scanned
;
782 spin_lock(&zone
->lock
);
783 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
785 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
789 struct list_head
*list
;
792 * Remove pages from lists in a round-robin fashion. A
793 * batch_free count is maintained that is incremented when an
794 * empty list is encountered. This is so more pages are freed
795 * off fuller lists instead of spinning excessively around empty
800 if (++migratetype
== MIGRATE_PCPTYPES
)
802 list
= &pcp
->lists
[migratetype
];
803 } while (list_empty(list
));
805 /* This is the only non-empty list. Free them all. */
806 if (batch_free
== MIGRATE_PCPTYPES
)
807 batch_free
= to_free
;
810 int mt
; /* migratetype of the to-be-freed page */
812 page
= list_last_entry(list
, struct page
, lru
);
813 /* must delete as __free_one_page list manipulates */
814 list_del(&page
->lru
);
816 mt
= get_pcppage_migratetype(page
);
817 /* MIGRATE_ISOLATE page should not go to pcplists */
818 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
819 /* Pageblock could have been isolated meanwhile */
820 if (unlikely(has_isolate_pageblock(zone
)))
821 mt
= get_pageblock_migratetype(page
);
823 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
);
824 trace_mm_page_pcpu_drain(page
, 0, mt
);
825 } while (--to_free
&& --batch_free
&& !list_empty(list
));
827 spin_unlock(&zone
->lock
);
830 static void free_one_page(struct zone
*zone
,
831 struct page
*page
, unsigned long pfn
,
835 unsigned long nr_scanned
;
836 spin_lock(&zone
->lock
);
837 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
839 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
841 if (unlikely(has_isolate_pageblock(zone
) ||
842 is_migrate_isolate(migratetype
))) {
843 migratetype
= get_pfnblock_migratetype(page
, pfn
);
845 __free_one_page(page
, pfn
, zone
, order
, migratetype
);
846 spin_unlock(&zone
->lock
);
849 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
854 * We rely page->lru.next never has bit 0 set, unless the page
855 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
857 BUILD_BUG_ON((unsigned long)LIST_POISON1
& 1);
859 if (!IS_ENABLED(CONFIG_DEBUG_VM
)) {
863 switch (page
- head_page
) {
865 /* the first tail page: ->mapping is compound_mapcount() */
866 if (unlikely(compound_mapcount(page
))) {
867 bad_page(page
, "nonzero compound_mapcount", 0);
873 * the second tail page: ->mapping is
874 * page_deferred_list().next -- ignore value.
878 if (page
->mapping
!= TAIL_MAPPING
) {
879 bad_page(page
, "corrupted mapping in tail page", 0);
884 if (unlikely(!PageTail(page
))) {
885 bad_page(page
, "PageTail not set", 0);
888 if (unlikely(compound_head(page
) != head_page
)) {
889 bad_page(page
, "compound_head not consistent", 0);
894 page
->mapping
= NULL
;
895 clear_compound_head(page
);
899 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
900 unsigned long zone
, int nid
)
902 set_page_links(page
, zone
, nid
, pfn
);
903 init_page_count(page
);
904 page_mapcount_reset(page
);
905 page_cpupid_reset_last(page
);
907 INIT_LIST_HEAD(&page
->lru
);
908 #ifdef WANT_PAGE_VIRTUAL
909 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
910 if (!is_highmem_idx(zone
))
911 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
915 static void __meminit
__init_single_pfn(unsigned long pfn
, unsigned long zone
,
918 return __init_single_page(pfn_to_page(pfn
), pfn
, zone
, nid
);
921 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
922 static void init_reserved_page(unsigned long pfn
)
927 if (!early_page_uninitialised(pfn
))
930 nid
= early_pfn_to_nid(pfn
);
931 pgdat
= NODE_DATA(nid
);
933 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
934 struct zone
*zone
= &pgdat
->node_zones
[zid
];
936 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
939 __init_single_pfn(pfn
, zid
, nid
);
942 static inline void init_reserved_page(unsigned long pfn
)
945 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
948 * Initialised pages do not have PageReserved set. This function is
949 * called for each range allocated by the bootmem allocator and
950 * marks the pages PageReserved. The remaining valid pages are later
951 * sent to the buddy page allocator.
953 void __meminit
reserve_bootmem_region(unsigned long start
, unsigned long end
)
955 unsigned long start_pfn
= PFN_DOWN(start
);
956 unsigned long end_pfn
= PFN_UP(end
);
958 for (; start_pfn
< end_pfn
; start_pfn
++) {
959 if (pfn_valid(start_pfn
)) {
960 struct page
*page
= pfn_to_page(start_pfn
);
962 init_reserved_page(start_pfn
);
964 /* Avoid false-positive PageTail() */
965 INIT_LIST_HEAD(&page
->lru
);
967 SetPageReserved(page
);
972 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
974 bool compound
= PageCompound(page
);
977 VM_BUG_ON_PAGE(PageTail(page
), page
);
978 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
980 trace_mm_page_free(page
, order
);
981 kmemcheck_free_shadow(page
, order
);
982 kasan_free_pages(page
, order
);
985 page
->mapping
= NULL
;
986 bad
+= free_pages_check(page
);
987 for (i
= 1; i
< (1 << order
); i
++) {
989 bad
+= free_tail_pages_check(page
, page
+ i
);
990 bad
+= free_pages_check(page
+ i
);
995 reset_page_owner(page
, order
);
997 if (!PageHighMem(page
)) {
998 debug_check_no_locks_freed(page_address(page
),
1000 debug_check_no_obj_freed(page_address(page
),
1001 PAGE_SIZE
<< order
);
1003 arch_free_page(page
, order
);
1004 kernel_map_pages(page
, 1 << order
, 0);
1009 static void __free_pages_ok(struct page
*page
, unsigned int order
)
1011 unsigned long flags
;
1013 unsigned long pfn
= page_to_pfn(page
);
1015 if (!free_pages_prepare(page
, order
))
1018 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1019 local_irq_save(flags
);
1020 __count_vm_events(PGFREE
, 1 << order
);
1021 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
1022 local_irq_restore(flags
);
1025 static void __init
__free_pages_boot_core(struct page
*page
,
1026 unsigned long pfn
, unsigned int order
)
1028 unsigned int nr_pages
= 1 << order
;
1029 struct page
*p
= page
;
1033 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
1035 __ClearPageReserved(p
);
1036 set_page_count(p
, 0);
1038 __ClearPageReserved(p
);
1039 set_page_count(p
, 0);
1041 page_zone(page
)->managed_pages
+= nr_pages
;
1042 set_page_refcounted(page
);
1043 __free_pages(page
, order
);
1046 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1047 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1049 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1051 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1053 static DEFINE_SPINLOCK(early_pfn_lock
);
1056 spin_lock(&early_pfn_lock
);
1057 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1060 spin_unlock(&early_pfn_lock
);
1066 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1067 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1068 struct mminit_pfnnid_cache
*state
)
1072 nid
= __early_pfn_to_nid(pfn
, state
);
1073 if (nid
>= 0 && nid
!= node
)
1078 /* Only safe to use early in boot when initialisation is single-threaded */
1079 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1081 return meminit_pfn_in_nid(pfn
, node
, &early_pfnnid_cache
);
1086 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1090 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1091 struct mminit_pfnnid_cache
*state
)
1098 void __init
__free_pages_bootmem(struct page
*page
, unsigned long pfn
,
1101 if (early_page_uninitialised(pfn
))
1103 return __free_pages_boot_core(page
, pfn
, order
);
1106 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1107 static void __init
deferred_free_range(struct page
*page
,
1108 unsigned long pfn
, int nr_pages
)
1115 /* Free a large naturally-aligned chunk if possible */
1116 if (nr_pages
== MAX_ORDER_NR_PAGES
&&
1117 (pfn
& (MAX_ORDER_NR_PAGES
-1)) == 0) {
1118 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1119 __free_pages_boot_core(page
, pfn
, MAX_ORDER
-1);
1123 for (i
= 0; i
< nr_pages
; i
++, page
++, pfn
++)
1124 __free_pages_boot_core(page
, pfn
, 0);
1127 /* Completion tracking for deferred_init_memmap() threads */
1128 static atomic_t pgdat_init_n_undone __initdata
;
1129 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1131 static inline void __init
pgdat_init_report_one_done(void)
1133 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1134 complete(&pgdat_init_all_done_comp
);
1137 /* Initialise remaining memory on a node */
1138 static int __init
deferred_init_memmap(void *data
)
1140 pg_data_t
*pgdat
= data
;
1141 int nid
= pgdat
->node_id
;
1142 struct mminit_pfnnid_cache nid_init_state
= { };
1143 unsigned long start
= jiffies
;
1144 unsigned long nr_pages
= 0;
1145 unsigned long walk_start
, walk_end
;
1148 unsigned long first_init_pfn
= pgdat
->first_deferred_pfn
;
1149 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1151 if (first_init_pfn
== ULONG_MAX
) {
1152 pgdat_init_report_one_done();
1156 /* Bind memory initialisation thread to a local node if possible */
1157 if (!cpumask_empty(cpumask
))
1158 set_cpus_allowed_ptr(current
, cpumask
);
1160 /* Sanity check boundaries */
1161 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1162 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1163 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1165 /* Only the highest zone is deferred so find it */
1166 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1167 zone
= pgdat
->node_zones
+ zid
;
1168 if (first_init_pfn
< zone_end_pfn(zone
))
1172 for_each_mem_pfn_range(i
, nid
, &walk_start
, &walk_end
, NULL
) {
1173 unsigned long pfn
, end_pfn
;
1174 struct page
*page
= NULL
;
1175 struct page
*free_base_page
= NULL
;
1176 unsigned long free_base_pfn
= 0;
1179 end_pfn
= min(walk_end
, zone_end_pfn(zone
));
1180 pfn
= first_init_pfn
;
1181 if (pfn
< walk_start
)
1183 if (pfn
< zone
->zone_start_pfn
)
1184 pfn
= zone
->zone_start_pfn
;
1186 for (; pfn
< end_pfn
; pfn
++) {
1187 if (!pfn_valid_within(pfn
))
1191 * Ensure pfn_valid is checked every
1192 * MAX_ORDER_NR_PAGES for memory holes
1194 if ((pfn
& (MAX_ORDER_NR_PAGES
- 1)) == 0) {
1195 if (!pfn_valid(pfn
)) {
1201 if (!meminit_pfn_in_nid(pfn
, nid
, &nid_init_state
)) {
1206 /* Minimise pfn page lookups and scheduler checks */
1207 if (page
&& (pfn
& (MAX_ORDER_NR_PAGES
- 1)) != 0) {
1210 nr_pages
+= nr_to_free
;
1211 deferred_free_range(free_base_page
,
1212 free_base_pfn
, nr_to_free
);
1213 free_base_page
= NULL
;
1214 free_base_pfn
= nr_to_free
= 0;
1216 page
= pfn_to_page(pfn
);
1221 VM_BUG_ON(page_zone(page
) != zone
);
1225 __init_single_page(page
, pfn
, zid
, nid
);
1226 if (!free_base_page
) {
1227 free_base_page
= page
;
1228 free_base_pfn
= pfn
;
1233 /* Where possible, batch up pages for a single free */
1236 /* Free the current block of pages to allocator */
1237 nr_pages
+= nr_to_free
;
1238 deferred_free_range(free_base_page
, free_base_pfn
,
1240 free_base_page
= NULL
;
1241 free_base_pfn
= nr_to_free
= 0;
1244 first_init_pfn
= max(end_pfn
, first_init_pfn
);
1247 /* Sanity check that the next zone really is unpopulated */
1248 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1250 pr_info("node %d initialised, %lu pages in %ums\n", nid
, nr_pages
,
1251 jiffies_to_msecs(jiffies
- start
));
1253 pgdat_init_report_one_done();
1257 void __init
page_alloc_init_late(void)
1261 /* There will be num_node_state(N_MEMORY) threads */
1262 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
1263 for_each_node_state(nid
, N_MEMORY
) {
1264 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
1267 /* Block until all are initialised */
1268 wait_for_completion(&pgdat_init_all_done_comp
);
1270 /* Reinit limits that are based on free pages after the kernel is up */
1271 files_maxfiles_init();
1273 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1276 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1277 void __init
init_cma_reserved_pageblock(struct page
*page
)
1279 unsigned i
= pageblock_nr_pages
;
1280 struct page
*p
= page
;
1283 __ClearPageReserved(p
);
1284 set_page_count(p
, 0);
1287 set_pageblock_migratetype(page
, MIGRATE_CMA
);
1289 if (pageblock_order
>= MAX_ORDER
) {
1290 i
= pageblock_nr_pages
;
1293 set_page_refcounted(p
);
1294 __free_pages(p
, MAX_ORDER
- 1);
1295 p
+= MAX_ORDER_NR_PAGES
;
1296 } while (i
-= MAX_ORDER_NR_PAGES
);
1298 set_page_refcounted(page
);
1299 __free_pages(page
, pageblock_order
);
1302 adjust_managed_page_count(page
, pageblock_nr_pages
);
1307 * The order of subdivision here is critical for the IO subsystem.
1308 * Please do not alter this order without good reasons and regression
1309 * testing. Specifically, as large blocks of memory are subdivided,
1310 * the order in which smaller blocks are delivered depends on the order
1311 * they're subdivided in this function. This is the primary factor
1312 * influencing the order in which pages are delivered to the IO
1313 * subsystem according to empirical testing, and this is also justified
1314 * by considering the behavior of a buddy system containing a single
1315 * large block of memory acted on by a series of small allocations.
1316 * This behavior is a critical factor in sglist merging's success.
1320 static inline void expand(struct zone
*zone
, struct page
*page
,
1321 int low
, int high
, struct free_area
*area
,
1324 unsigned long size
= 1 << high
;
1326 while (high
> low
) {
1330 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
1332 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC
) &&
1333 debug_guardpage_enabled() &&
1334 high
< debug_guardpage_minorder()) {
1336 * Mark as guard pages (or page), that will allow to
1337 * merge back to allocator when buddy will be freed.
1338 * Corresponding page table entries will not be touched,
1339 * pages will stay not present in virtual address space
1341 set_page_guard(zone
, &page
[size
], high
, migratetype
);
1344 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
1346 set_page_order(&page
[size
], high
);
1351 * This page is about to be returned from the page allocator
1353 static inline int check_new_page(struct page
*page
)
1355 const char *bad_reason
= NULL
;
1356 unsigned long bad_flags
= 0;
1358 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1359 bad_reason
= "nonzero mapcount";
1360 if (unlikely(page
->mapping
!= NULL
))
1361 bad_reason
= "non-NULL mapping";
1362 if (unlikely(atomic_read(&page
->_count
) != 0))
1363 bad_reason
= "nonzero _count";
1364 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
1365 bad_reason
= "HWPoisoned (hardware-corrupted)";
1366 bad_flags
= __PG_HWPOISON
;
1368 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
1369 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
1370 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
1373 if (unlikely(page
->mem_cgroup
))
1374 bad_reason
= "page still charged to cgroup";
1376 if (unlikely(bad_reason
)) {
1377 bad_page(page
, bad_reason
, bad_flags
);
1383 static int prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
1388 for (i
= 0; i
< (1 << order
); i
++) {
1389 struct page
*p
= page
+ i
;
1390 if (unlikely(check_new_page(p
)))
1394 set_page_private(page
, 0);
1395 set_page_refcounted(page
);
1397 arch_alloc_page(page
, order
);
1398 kernel_map_pages(page
, 1 << order
, 1);
1399 kasan_alloc_pages(page
, order
);
1401 if (gfp_flags
& __GFP_ZERO
)
1402 for (i
= 0; i
< (1 << order
); i
++)
1403 clear_highpage(page
+ i
);
1405 if (order
&& (gfp_flags
& __GFP_COMP
))
1406 prep_compound_page(page
, order
);
1408 set_page_owner(page
, order
, gfp_flags
);
1411 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1412 * allocate the page. The expectation is that the caller is taking
1413 * steps that will free more memory. The caller should avoid the page
1414 * being used for !PFMEMALLOC purposes.
1416 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
1417 set_page_pfmemalloc(page
);
1419 clear_page_pfmemalloc(page
);
1425 * Go through the free lists for the given migratetype and remove
1426 * the smallest available page from the freelists
1429 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
1432 unsigned int current_order
;
1433 struct free_area
*area
;
1436 /* Find a page of the appropriate size in the preferred list */
1437 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
1438 area
= &(zone
->free_area
[current_order
]);
1439 page
= list_first_entry_or_null(&area
->free_list
[migratetype
],
1443 list_del(&page
->lru
);
1444 rmv_page_order(page
);
1446 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1447 set_pcppage_migratetype(page
, migratetype
);
1456 * This array describes the order lists are fallen back to when
1457 * the free lists for the desirable migrate type are depleted
1459 static int fallbacks
[MIGRATE_TYPES
][4] = {
1460 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1461 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1462 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_TYPES
},
1464 [MIGRATE_CMA
] = { MIGRATE_TYPES
}, /* Never used */
1466 #ifdef CONFIG_MEMORY_ISOLATION
1467 [MIGRATE_ISOLATE
] = { MIGRATE_TYPES
}, /* Never used */
1472 static struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1475 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
1478 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1479 unsigned int order
) { return NULL
; }
1483 * Move the free pages in a range to the free lists of the requested type.
1484 * Note that start_page and end_pages are not aligned on a pageblock
1485 * boundary. If alignment is required, use move_freepages_block()
1487 int move_freepages(struct zone
*zone
,
1488 struct page
*start_page
, struct page
*end_page
,
1493 int pages_moved
= 0;
1495 #ifndef CONFIG_HOLES_IN_ZONE
1497 * page_zone is not safe to call in this context when
1498 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1499 * anyway as we check zone boundaries in move_freepages_block().
1500 * Remove at a later date when no bug reports exist related to
1501 * grouping pages by mobility
1503 VM_BUG_ON(page_zone(start_page
) != page_zone(end_page
));
1506 for (page
= start_page
; page
<= end_page
;) {
1507 /* Make sure we are not inadvertently changing nodes */
1508 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
1510 if (!pfn_valid_within(page_to_pfn(page
))) {
1515 if (!PageBuddy(page
)) {
1520 order
= page_order(page
);
1521 list_move(&page
->lru
,
1522 &zone
->free_area
[order
].free_list
[migratetype
]);
1524 pages_moved
+= 1 << order
;
1530 int move_freepages_block(struct zone
*zone
, struct page
*page
,
1533 unsigned long start_pfn
, end_pfn
;
1534 struct page
*start_page
, *end_page
;
1536 start_pfn
= page_to_pfn(page
);
1537 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
1538 start_page
= pfn_to_page(start_pfn
);
1539 end_page
= start_page
+ pageblock_nr_pages
- 1;
1540 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
1542 /* Do not cross zone boundaries */
1543 if (!zone_spans_pfn(zone
, start_pfn
))
1545 if (!zone_spans_pfn(zone
, end_pfn
))
1548 return move_freepages(zone
, start_page
, end_page
, migratetype
);
1551 static void change_pageblock_range(struct page
*pageblock_page
,
1552 int start_order
, int migratetype
)
1554 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1556 while (nr_pageblocks
--) {
1557 set_pageblock_migratetype(pageblock_page
, migratetype
);
1558 pageblock_page
+= pageblock_nr_pages
;
1563 * When we are falling back to another migratetype during allocation, try to
1564 * steal extra free pages from the same pageblocks to satisfy further
1565 * allocations, instead of polluting multiple pageblocks.
1567 * If we are stealing a relatively large buddy page, it is likely there will
1568 * be more free pages in the pageblock, so try to steal them all. For
1569 * reclaimable and unmovable allocations, we steal regardless of page size,
1570 * as fragmentation caused by those allocations polluting movable pageblocks
1571 * is worse than movable allocations stealing from unmovable and reclaimable
1574 static bool can_steal_fallback(unsigned int order
, int start_mt
)
1577 * Leaving this order check is intended, although there is
1578 * relaxed order check in next check. The reason is that
1579 * we can actually steal whole pageblock if this condition met,
1580 * but, below check doesn't guarantee it and that is just heuristic
1581 * so could be changed anytime.
1583 if (order
>= pageblock_order
)
1586 if (order
>= pageblock_order
/ 2 ||
1587 start_mt
== MIGRATE_RECLAIMABLE
||
1588 start_mt
== MIGRATE_UNMOVABLE
||
1589 page_group_by_mobility_disabled
)
1596 * This function implements actual steal behaviour. If order is large enough,
1597 * we can steal whole pageblock. If not, we first move freepages in this
1598 * pageblock and check whether half of pages are moved or not. If half of
1599 * pages are moved, we can change migratetype of pageblock and permanently
1600 * use it's pages as requested migratetype in the future.
1602 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
1605 unsigned int current_order
= page_order(page
);
1608 /* Take ownership for orders >= pageblock_order */
1609 if (current_order
>= pageblock_order
) {
1610 change_pageblock_range(page
, current_order
, start_type
);
1614 pages
= move_freepages_block(zone
, page
, start_type
);
1616 /* Claim the whole block if over half of it is free */
1617 if (pages
>= (1 << (pageblock_order
-1)) ||
1618 page_group_by_mobility_disabled
)
1619 set_pageblock_migratetype(page
, start_type
);
1623 * Check whether there is a suitable fallback freepage with requested order.
1624 * If only_stealable is true, this function returns fallback_mt only if
1625 * we can steal other freepages all together. This would help to reduce
1626 * fragmentation due to mixed migratetype pages in one pageblock.
1628 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
1629 int migratetype
, bool only_stealable
, bool *can_steal
)
1634 if (area
->nr_free
== 0)
1639 fallback_mt
= fallbacks
[migratetype
][i
];
1640 if (fallback_mt
== MIGRATE_TYPES
)
1643 if (list_empty(&area
->free_list
[fallback_mt
]))
1646 if (can_steal_fallback(order
, migratetype
))
1649 if (!only_stealable
)
1660 * Reserve a pageblock for exclusive use of high-order atomic allocations if
1661 * there are no empty page blocks that contain a page with a suitable order
1663 static void reserve_highatomic_pageblock(struct page
*page
, struct zone
*zone
,
1664 unsigned int alloc_order
)
1667 unsigned long max_managed
, flags
;
1670 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
1671 * Check is race-prone but harmless.
1673 max_managed
= (zone
->managed_pages
/ 100) + pageblock_nr_pages
;
1674 if (zone
->nr_reserved_highatomic
>= max_managed
)
1677 spin_lock_irqsave(&zone
->lock
, flags
);
1679 /* Recheck the nr_reserved_highatomic limit under the lock */
1680 if (zone
->nr_reserved_highatomic
>= max_managed
)
1684 mt
= get_pageblock_migratetype(page
);
1685 if (mt
!= MIGRATE_HIGHATOMIC
&&
1686 !is_migrate_isolate(mt
) && !is_migrate_cma(mt
)) {
1687 zone
->nr_reserved_highatomic
+= pageblock_nr_pages
;
1688 set_pageblock_migratetype(page
, MIGRATE_HIGHATOMIC
);
1689 move_freepages_block(zone
, page
, MIGRATE_HIGHATOMIC
);
1693 spin_unlock_irqrestore(&zone
->lock
, flags
);
1697 * Used when an allocation is about to fail under memory pressure. This
1698 * potentially hurts the reliability of high-order allocations when under
1699 * intense memory pressure but failed atomic allocations should be easier
1700 * to recover from than an OOM.
1702 static void unreserve_highatomic_pageblock(const struct alloc_context
*ac
)
1704 struct zonelist
*zonelist
= ac
->zonelist
;
1705 unsigned long flags
;
1711 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
1713 /* Preserve at least one pageblock */
1714 if (zone
->nr_reserved_highatomic
<= pageblock_nr_pages
)
1717 spin_lock_irqsave(&zone
->lock
, flags
);
1718 for (order
= 0; order
< MAX_ORDER
; order
++) {
1719 struct free_area
*area
= &(zone
->free_area
[order
]);
1721 page
= list_first_entry_or_null(
1722 &area
->free_list
[MIGRATE_HIGHATOMIC
],
1728 * It should never happen but changes to locking could
1729 * inadvertently allow a per-cpu drain to add pages
1730 * to MIGRATE_HIGHATOMIC while unreserving so be safe
1731 * and watch for underflows.
1733 zone
->nr_reserved_highatomic
-= min(pageblock_nr_pages
,
1734 zone
->nr_reserved_highatomic
);
1737 * Convert to ac->migratetype and avoid the normal
1738 * pageblock stealing heuristics. Minimally, the caller
1739 * is doing the work and needs the pages. More
1740 * importantly, if the block was always converted to
1741 * MIGRATE_UNMOVABLE or another type then the number
1742 * of pageblocks that cannot be completely freed
1745 set_pageblock_migratetype(page
, ac
->migratetype
);
1746 move_freepages_block(zone
, page
, ac
->migratetype
);
1747 spin_unlock_irqrestore(&zone
->lock
, flags
);
1750 spin_unlock_irqrestore(&zone
->lock
, flags
);
1754 /* Remove an element from the buddy allocator from the fallback list */
1755 static inline struct page
*
1756 __rmqueue_fallback(struct zone
*zone
, unsigned int order
, int start_migratetype
)
1758 struct free_area
*area
;
1759 unsigned int current_order
;
1764 /* Find the largest possible block of pages in the other list */
1765 for (current_order
= MAX_ORDER
-1;
1766 current_order
>= order
&& current_order
<= MAX_ORDER
-1;
1768 area
= &(zone
->free_area
[current_order
]);
1769 fallback_mt
= find_suitable_fallback(area
, current_order
,
1770 start_migratetype
, false, &can_steal
);
1771 if (fallback_mt
== -1)
1774 page
= list_first_entry(&area
->free_list
[fallback_mt
],
1777 steal_suitable_fallback(zone
, page
, start_migratetype
);
1779 /* Remove the page from the freelists */
1781 list_del(&page
->lru
);
1782 rmv_page_order(page
);
1784 expand(zone
, page
, order
, current_order
, area
,
1787 * The pcppage_migratetype may differ from pageblock's
1788 * migratetype depending on the decisions in
1789 * find_suitable_fallback(). This is OK as long as it does not
1790 * differ for MIGRATE_CMA pageblocks. Those can be used as
1791 * fallback only via special __rmqueue_cma_fallback() function
1793 set_pcppage_migratetype(page
, start_migratetype
);
1795 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
1796 start_migratetype
, fallback_mt
);
1805 * Do the hard work of removing an element from the buddy allocator.
1806 * Call me with the zone->lock already held.
1808 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
1813 page
= __rmqueue_smallest(zone
, order
, migratetype
);
1814 if (unlikely(!page
)) {
1815 if (migratetype
== MIGRATE_MOVABLE
)
1816 page
= __rmqueue_cma_fallback(zone
, order
);
1819 page
= __rmqueue_fallback(zone
, order
, migratetype
);
1822 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1827 * Obtain a specified number of elements from the buddy allocator, all under
1828 * a single hold of the lock, for efficiency. Add them to the supplied list.
1829 * Returns the number of new pages which were placed at *list.
1831 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1832 unsigned long count
, struct list_head
*list
,
1833 int migratetype
, bool cold
)
1837 spin_lock(&zone
->lock
);
1838 for (i
= 0; i
< count
; ++i
) {
1839 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
1840 if (unlikely(page
== NULL
))
1844 * Split buddy pages returned by expand() are received here
1845 * in physical page order. The page is added to the callers and
1846 * list and the list head then moves forward. From the callers
1847 * perspective, the linked list is ordered by page number in
1848 * some conditions. This is useful for IO devices that can
1849 * merge IO requests if the physical pages are ordered
1853 list_add(&page
->lru
, list
);
1855 list_add_tail(&page
->lru
, list
);
1857 if (is_migrate_cma(get_pcppage_migratetype(page
)))
1858 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
1861 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
1862 spin_unlock(&zone
->lock
);
1868 * Called from the vmstat counter updater to drain pagesets of this
1869 * currently executing processor on remote nodes after they have
1872 * Note that this function must be called with the thread pinned to
1873 * a single processor.
1875 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
1877 unsigned long flags
;
1878 int to_drain
, batch
;
1880 local_irq_save(flags
);
1881 batch
= READ_ONCE(pcp
->batch
);
1882 to_drain
= min(pcp
->count
, batch
);
1884 free_pcppages_bulk(zone
, to_drain
, pcp
);
1885 pcp
->count
-= to_drain
;
1887 local_irq_restore(flags
);
1892 * Drain pcplists of the indicated processor and zone.
1894 * The processor must either be the current processor and the
1895 * thread pinned to the current processor or a processor that
1898 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
1900 unsigned long flags
;
1901 struct per_cpu_pageset
*pset
;
1902 struct per_cpu_pages
*pcp
;
1904 local_irq_save(flags
);
1905 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
1909 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1912 local_irq_restore(flags
);
1916 * Drain pcplists of all zones on the indicated processor.
1918 * The processor must either be the current processor and the
1919 * thread pinned to the current processor or a processor that
1922 static void drain_pages(unsigned int cpu
)
1926 for_each_populated_zone(zone
) {
1927 drain_pages_zone(cpu
, zone
);
1932 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1934 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
1935 * the single zone's pages.
1937 void drain_local_pages(struct zone
*zone
)
1939 int cpu
= smp_processor_id();
1942 drain_pages_zone(cpu
, zone
);
1948 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1950 * When zone parameter is non-NULL, spill just the single zone's pages.
1952 * Note that this code is protected against sending an IPI to an offline
1953 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1954 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1955 * nothing keeps CPUs from showing up after we populated the cpumask and
1956 * before the call to on_each_cpu_mask().
1958 void drain_all_pages(struct zone
*zone
)
1963 * Allocate in the BSS so we wont require allocation in
1964 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1966 static cpumask_t cpus_with_pcps
;
1969 * We don't care about racing with CPU hotplug event
1970 * as offline notification will cause the notified
1971 * cpu to drain that CPU pcps and on_each_cpu_mask
1972 * disables preemption as part of its processing
1974 for_each_online_cpu(cpu
) {
1975 struct per_cpu_pageset
*pcp
;
1977 bool has_pcps
= false;
1980 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
1984 for_each_populated_zone(z
) {
1985 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
1986 if (pcp
->pcp
.count
) {
1994 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
1996 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
1998 on_each_cpu_mask(&cpus_with_pcps
, (smp_call_func_t
) drain_local_pages
,
2002 #ifdef CONFIG_HIBERNATION
2004 void mark_free_pages(struct zone
*zone
)
2006 unsigned long pfn
, max_zone_pfn
;
2007 unsigned long flags
;
2008 unsigned int order
, t
;
2011 if (zone_is_empty(zone
))
2014 spin_lock_irqsave(&zone
->lock
, flags
);
2016 max_zone_pfn
= zone_end_pfn(zone
);
2017 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
2018 if (pfn_valid(pfn
)) {
2019 page
= pfn_to_page(pfn
);
2020 if (!swsusp_page_is_forbidden(page
))
2021 swsusp_unset_page_free(page
);
2024 for_each_migratetype_order(order
, t
) {
2025 list_for_each_entry(page
,
2026 &zone
->free_area
[order
].free_list
[t
], lru
) {
2029 pfn
= page_to_pfn(page
);
2030 for (i
= 0; i
< (1UL << order
); i
++)
2031 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
2034 spin_unlock_irqrestore(&zone
->lock
, flags
);
2036 #endif /* CONFIG_PM */
2039 * Free a 0-order page
2040 * cold == true ? free a cold page : free a hot page
2042 void free_hot_cold_page(struct page
*page
, bool cold
)
2044 struct zone
*zone
= page_zone(page
);
2045 struct per_cpu_pages
*pcp
;
2046 unsigned long flags
;
2047 unsigned long pfn
= page_to_pfn(page
);
2050 if (!free_pages_prepare(page
, 0))
2053 migratetype
= get_pfnblock_migratetype(page
, pfn
);
2054 set_pcppage_migratetype(page
, migratetype
);
2055 local_irq_save(flags
);
2056 __count_vm_event(PGFREE
);
2059 * We only track unmovable, reclaimable and movable on pcp lists.
2060 * Free ISOLATE pages back to the allocator because they are being
2061 * offlined but treat RESERVE as movable pages so we can get those
2062 * areas back if necessary. Otherwise, we may have to free
2063 * excessively into the page allocator
2065 if (migratetype
>= MIGRATE_PCPTYPES
) {
2066 if (unlikely(is_migrate_isolate(migratetype
))) {
2067 free_one_page(zone
, page
, pfn
, 0, migratetype
);
2070 migratetype
= MIGRATE_MOVABLE
;
2073 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2075 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
2077 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
2079 if (pcp
->count
>= pcp
->high
) {
2080 unsigned long batch
= READ_ONCE(pcp
->batch
);
2081 free_pcppages_bulk(zone
, batch
, pcp
);
2082 pcp
->count
-= batch
;
2086 local_irq_restore(flags
);
2090 * Free a list of 0-order pages
2092 void free_hot_cold_page_list(struct list_head
*list
, bool cold
)
2094 struct page
*page
, *next
;
2096 list_for_each_entry_safe(page
, next
, list
, lru
) {
2097 trace_mm_page_free_batched(page
, cold
);
2098 free_hot_cold_page(page
, cold
);
2103 * split_page takes a non-compound higher-order page, and splits it into
2104 * n (1<<order) sub-pages: page[0..n]
2105 * Each sub-page must be freed individually.
2107 * Note: this is probably too low level an operation for use in drivers.
2108 * Please consult with lkml before using this in your driver.
2110 void split_page(struct page
*page
, unsigned int order
)
2115 VM_BUG_ON_PAGE(PageCompound(page
), page
);
2116 VM_BUG_ON_PAGE(!page_count(page
), page
);
2118 #ifdef CONFIG_KMEMCHECK
2120 * Split shadow pages too, because free(page[0]) would
2121 * otherwise free the whole shadow.
2123 if (kmemcheck_page_is_tracked(page
))
2124 split_page(virt_to_page(page
[0].shadow
), order
);
2127 gfp_mask
= get_page_owner_gfp(page
);
2128 set_page_owner(page
, 0, gfp_mask
);
2129 for (i
= 1; i
< (1 << order
); i
++) {
2130 set_page_refcounted(page
+ i
);
2131 set_page_owner(page
+ i
, 0, gfp_mask
);
2134 EXPORT_SYMBOL_GPL(split_page
);
2136 int __isolate_free_page(struct page
*page
, unsigned int order
)
2138 unsigned long watermark
;
2142 BUG_ON(!PageBuddy(page
));
2144 zone
= page_zone(page
);
2145 mt
= get_pageblock_migratetype(page
);
2147 if (!is_migrate_isolate(mt
)) {
2148 /* Obey watermarks as if the page was being allocated */
2149 watermark
= low_wmark_pages(zone
) + (1 << order
);
2150 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
2153 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
2156 /* Remove page from free list */
2157 list_del(&page
->lru
);
2158 zone
->free_area
[order
].nr_free
--;
2159 rmv_page_order(page
);
2161 set_page_owner(page
, order
, __GFP_MOVABLE
);
2163 /* Set the pageblock if the isolated page is at least a pageblock */
2164 if (order
>= pageblock_order
- 1) {
2165 struct page
*endpage
= page
+ (1 << order
) - 1;
2166 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
2167 int mt
= get_pageblock_migratetype(page
);
2168 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
))
2169 set_pageblock_migratetype(page
,
2175 return 1UL << order
;
2179 * Similar to split_page except the page is already free. As this is only
2180 * being used for migration, the migratetype of the block also changes.
2181 * As this is called with interrupts disabled, the caller is responsible
2182 * for calling arch_alloc_page() and kernel_map_page() after interrupts
2185 * Note: this is probably too low level an operation for use in drivers.
2186 * Please consult with lkml before using this in your driver.
2188 int split_free_page(struct page
*page
)
2193 order
= page_order(page
);
2195 nr_pages
= __isolate_free_page(page
, order
);
2199 /* Split into individual pages */
2200 set_page_refcounted(page
);
2201 split_page(page
, order
);
2206 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2209 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
2210 struct zone
*zone
, unsigned int order
,
2211 gfp_t gfp_flags
, int alloc_flags
, int migratetype
)
2213 unsigned long flags
;
2215 bool cold
= ((gfp_flags
& __GFP_COLD
) != 0);
2217 if (likely(order
== 0)) {
2218 struct per_cpu_pages
*pcp
;
2219 struct list_head
*list
;
2221 local_irq_save(flags
);
2222 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2223 list
= &pcp
->lists
[migratetype
];
2224 if (list_empty(list
)) {
2225 pcp
->count
+= rmqueue_bulk(zone
, 0,
2228 if (unlikely(list_empty(list
)))
2233 page
= list_last_entry(list
, struct page
, lru
);
2235 page
= list_first_entry(list
, struct page
, lru
);
2237 list_del(&page
->lru
);
2240 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
2242 * __GFP_NOFAIL is not to be used in new code.
2244 * All __GFP_NOFAIL callers should be fixed so that they
2245 * properly detect and handle allocation failures.
2247 * We most definitely don't want callers attempting to
2248 * allocate greater than order-1 page units with
2251 WARN_ON_ONCE(order
> 1);
2253 spin_lock_irqsave(&zone
->lock
, flags
);
2256 if (alloc_flags
& ALLOC_HARDER
) {
2257 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
2259 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2262 page
= __rmqueue(zone
, order
, migratetype
);
2263 spin_unlock(&zone
->lock
);
2266 __mod_zone_freepage_state(zone
, -(1 << order
),
2267 get_pcppage_migratetype(page
));
2270 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
, -(1 << order
));
2271 if (atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]) <= 0 &&
2272 !test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
))
2273 set_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2275 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
2276 zone_statistics(preferred_zone
, zone
, gfp_flags
);
2277 local_irq_restore(flags
);
2279 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
2283 local_irq_restore(flags
);
2287 #ifdef CONFIG_FAIL_PAGE_ALLOC
2290 struct fault_attr attr
;
2292 bool ignore_gfp_highmem
;
2293 bool ignore_gfp_reclaim
;
2295 } fail_page_alloc
= {
2296 .attr
= FAULT_ATTR_INITIALIZER
,
2297 .ignore_gfp_reclaim
= true,
2298 .ignore_gfp_highmem
= true,
2302 static int __init
setup_fail_page_alloc(char *str
)
2304 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
2306 __setup("fail_page_alloc=", setup_fail_page_alloc
);
2308 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2310 if (order
< fail_page_alloc
.min_order
)
2312 if (gfp_mask
& __GFP_NOFAIL
)
2314 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
2316 if (fail_page_alloc
.ignore_gfp_reclaim
&&
2317 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
2320 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
2323 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2325 static int __init
fail_page_alloc_debugfs(void)
2327 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
2330 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
2331 &fail_page_alloc
.attr
);
2333 return PTR_ERR(dir
);
2335 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
2336 &fail_page_alloc
.ignore_gfp_reclaim
))
2338 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
2339 &fail_page_alloc
.ignore_gfp_highmem
))
2341 if (!debugfs_create_u32("min-order", mode
, dir
,
2342 &fail_page_alloc
.min_order
))
2347 debugfs_remove_recursive(dir
);
2352 late_initcall(fail_page_alloc_debugfs
);
2354 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2356 #else /* CONFIG_FAIL_PAGE_ALLOC */
2358 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2363 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2366 * Return true if free base pages are above 'mark'. For high-order checks it
2367 * will return true of the order-0 watermark is reached and there is at least
2368 * one free page of a suitable size. Checking now avoids taking the zone lock
2369 * to check in the allocation paths if no pages are free.
2371 static bool __zone_watermark_ok(struct zone
*z
, unsigned int order
,
2372 unsigned long mark
, int classzone_idx
, int alloc_flags
,
2377 const int alloc_harder
= (alloc_flags
& ALLOC_HARDER
);
2379 /* free_pages may go negative - that's OK */
2380 free_pages
-= (1 << order
) - 1;
2382 if (alloc_flags
& ALLOC_HIGH
)
2386 * If the caller does not have rights to ALLOC_HARDER then subtract
2387 * the high-atomic reserves. This will over-estimate the size of the
2388 * atomic reserve but it avoids a search.
2390 if (likely(!alloc_harder
))
2391 free_pages
-= z
->nr_reserved_highatomic
;
2396 /* If allocation can't use CMA areas don't use free CMA pages */
2397 if (!(alloc_flags
& ALLOC_CMA
))
2398 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2402 * Check watermarks for an order-0 allocation request. If these
2403 * are not met, then a high-order request also cannot go ahead
2404 * even if a suitable page happened to be free.
2406 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
2409 /* If this is an order-0 request then the watermark is fine */
2413 /* For a high-order request, check at least one suitable page is free */
2414 for (o
= order
; o
< MAX_ORDER
; o
++) {
2415 struct free_area
*area
= &z
->free_area
[o
];
2424 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
2425 if (!list_empty(&area
->free_list
[mt
]))
2430 if ((alloc_flags
& ALLOC_CMA
) &&
2431 !list_empty(&area
->free_list
[MIGRATE_CMA
])) {
2439 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2440 int classzone_idx
, int alloc_flags
)
2442 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
2443 zone_page_state(z
, NR_FREE_PAGES
));
2446 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
2447 unsigned long mark
, int classzone_idx
)
2449 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
2451 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
2452 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
2454 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, 0,
2459 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2461 return local_zone
->node
== zone
->node
;
2464 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2466 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <
2469 #else /* CONFIG_NUMA */
2470 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2475 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2479 #endif /* CONFIG_NUMA */
2481 static void reset_alloc_batches(struct zone
*preferred_zone
)
2483 struct zone
*zone
= preferred_zone
->zone_pgdat
->node_zones
;
2486 mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
2487 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
2488 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
2489 clear_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2490 } while (zone
++ != preferred_zone
);
2494 * get_page_from_freelist goes through the zonelist trying to allocate
2497 static struct page
*
2498 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
2499 const struct alloc_context
*ac
)
2501 struct zonelist
*zonelist
= ac
->zonelist
;
2503 struct page
*page
= NULL
;
2505 int nr_fair_skipped
= 0;
2506 bool zonelist_rescan
;
2509 zonelist_rescan
= false;
2512 * Scan zonelist, looking for a zone with enough free.
2513 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2515 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
2519 if (cpusets_enabled() &&
2520 (alloc_flags
& ALLOC_CPUSET
) &&
2521 !cpuset_zone_allowed(zone
, gfp_mask
))
2524 * Distribute pages in proportion to the individual
2525 * zone size to ensure fair page aging. The zone a
2526 * page was allocated in should have no effect on the
2527 * time the page has in memory before being reclaimed.
2529 if (alloc_flags
& ALLOC_FAIR
) {
2530 if (!zone_local(ac
->preferred_zone
, zone
))
2532 if (test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
)) {
2538 * When allocating a page cache page for writing, we
2539 * want to get it from a zone that is within its dirty
2540 * limit, such that no single zone holds more than its
2541 * proportional share of globally allowed dirty pages.
2542 * The dirty limits take into account the zone's
2543 * lowmem reserves and high watermark so that kswapd
2544 * should be able to balance it without having to
2545 * write pages from its LRU list.
2547 * This may look like it could increase pressure on
2548 * lower zones by failing allocations in higher zones
2549 * before they are full. But the pages that do spill
2550 * over are limited as the lower zones are protected
2551 * by this very same mechanism. It should not become
2552 * a practical burden to them.
2554 * XXX: For now, allow allocations to potentially
2555 * exceed the per-zone dirty limit in the slowpath
2556 * (spread_dirty_pages unset) before going into reclaim,
2557 * which is important when on a NUMA setup the allowed
2558 * zones are together not big enough to reach the
2559 * global limit. The proper fix for these situations
2560 * will require awareness of zones in the
2561 * dirty-throttling and the flusher threads.
2563 if (ac
->spread_dirty_pages
&& !zone_dirty_ok(zone
))
2566 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
2567 if (!zone_watermark_ok(zone
, order
, mark
,
2568 ac
->classzone_idx
, alloc_flags
)) {
2571 /* Checked here to keep the fast path fast */
2572 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
2573 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
2576 if (zone_reclaim_mode
== 0 ||
2577 !zone_allows_reclaim(ac
->preferred_zone
, zone
))
2580 ret
= zone_reclaim(zone
, gfp_mask
, order
);
2582 case ZONE_RECLAIM_NOSCAN
:
2585 case ZONE_RECLAIM_FULL
:
2586 /* scanned but unreclaimable */
2589 /* did we reclaim enough */
2590 if (zone_watermark_ok(zone
, order
, mark
,
2591 ac
->classzone_idx
, alloc_flags
))
2599 page
= buffered_rmqueue(ac
->preferred_zone
, zone
, order
,
2600 gfp_mask
, alloc_flags
, ac
->migratetype
);
2602 if (prep_new_page(page
, order
, gfp_mask
, alloc_flags
))
2606 * If this is a high-order atomic allocation then check
2607 * if the pageblock should be reserved for the future
2609 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
2610 reserve_highatomic_pageblock(page
, zone
, order
);
2617 * The first pass makes sure allocations are spread fairly within the
2618 * local node. However, the local node might have free pages left
2619 * after the fairness batches are exhausted, and remote zones haven't
2620 * even been considered yet. Try once more without fairness, and
2621 * include remote zones now, before entering the slowpath and waking
2622 * kswapd: prefer spilling to a remote zone over swapping locally.
2624 if (alloc_flags
& ALLOC_FAIR
) {
2625 alloc_flags
&= ~ALLOC_FAIR
;
2626 if (nr_fair_skipped
) {
2627 zonelist_rescan
= true;
2628 reset_alloc_batches(ac
->preferred_zone
);
2630 if (nr_online_nodes
> 1)
2631 zonelist_rescan
= true;
2634 if (zonelist_rescan
)
2641 * Large machines with many possible nodes should not always dump per-node
2642 * meminfo in irq context.
2644 static inline bool should_suppress_show_mem(void)
2649 ret
= in_interrupt();
2654 static DEFINE_RATELIMIT_STATE(nopage_rs
,
2655 DEFAULT_RATELIMIT_INTERVAL
,
2656 DEFAULT_RATELIMIT_BURST
);
2658 void warn_alloc_failed(gfp_t gfp_mask
, unsigned int order
, const char *fmt
, ...)
2660 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
2662 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
2663 debug_guardpage_minorder() > 0)
2667 * This documents exceptions given to allocations in certain
2668 * contexts that are allowed to allocate outside current's set
2671 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2672 if (test_thread_flag(TIF_MEMDIE
) ||
2673 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
2674 filter
&= ~SHOW_MEM_FILTER_NODES
;
2675 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
2676 filter
&= ~SHOW_MEM_FILTER_NODES
;
2679 struct va_format vaf
;
2682 va_start(args
, fmt
);
2687 pr_warn("%pV", &vaf
);
2692 pr_warn("%s: page allocation failure: order:%u, mode:0x%x\n",
2693 current
->comm
, order
, gfp_mask
);
2696 if (!should_suppress_show_mem())
2700 static inline struct page
*
2701 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
2702 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
2704 struct oom_control oc
= {
2705 .zonelist
= ac
->zonelist
,
2706 .nodemask
= ac
->nodemask
,
2707 .gfp_mask
= gfp_mask
,
2712 *did_some_progress
= 0;
2715 * Acquire the oom lock. If that fails, somebody else is
2716 * making progress for us.
2718 if (!mutex_trylock(&oom_lock
)) {
2719 *did_some_progress
= 1;
2720 schedule_timeout_uninterruptible(1);
2725 * Go through the zonelist yet one more time, keep very high watermark
2726 * here, this is only to catch a parallel oom killing, we must fail if
2727 * we're still under heavy pressure.
2729 page
= get_page_from_freelist(gfp_mask
| __GFP_HARDWALL
, order
,
2730 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
2734 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2735 /* Coredumps can quickly deplete all memory reserves */
2736 if (current
->flags
& PF_DUMPCORE
)
2738 /* The OOM killer will not help higher order allocs */
2739 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2741 /* The OOM killer does not needlessly kill tasks for lowmem */
2742 if (ac
->high_zoneidx
< ZONE_NORMAL
)
2744 /* The OOM killer does not compensate for IO-less reclaim */
2745 if (!(gfp_mask
& __GFP_FS
)) {
2747 * XXX: Page reclaim didn't yield anything,
2748 * and the OOM killer can't be invoked, but
2749 * keep looping as per tradition.
2751 *did_some_progress
= 1;
2754 if (pm_suspended_storage())
2756 /* The OOM killer may not free memory on a specific node */
2757 if (gfp_mask
& __GFP_THISNODE
)
2760 /* Exhausted what can be done so it's blamo time */
2761 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
2762 *did_some_progress
= 1;
2764 if (gfp_mask
& __GFP_NOFAIL
) {
2765 page
= get_page_from_freelist(gfp_mask
, order
,
2766 ALLOC_NO_WATERMARKS
|ALLOC_CPUSET
, ac
);
2768 * fallback to ignore cpuset restriction if our nodes
2772 page
= get_page_from_freelist(gfp_mask
, order
,
2773 ALLOC_NO_WATERMARKS
, ac
);
2777 mutex_unlock(&oom_lock
);
2781 #ifdef CONFIG_COMPACTION
2782 /* Try memory compaction for high-order allocations before reclaim */
2783 static struct page
*
2784 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2785 int alloc_flags
, const struct alloc_context
*ac
,
2786 enum migrate_mode mode
, int *contended_compaction
,
2787 bool *deferred_compaction
)
2789 unsigned long compact_result
;
2795 current
->flags
|= PF_MEMALLOC
;
2796 compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
2797 mode
, contended_compaction
);
2798 current
->flags
&= ~PF_MEMALLOC
;
2800 switch (compact_result
) {
2801 case COMPACT_DEFERRED
:
2802 *deferred_compaction
= true;
2804 case COMPACT_SKIPPED
:
2811 * At least in one zone compaction wasn't deferred or skipped, so let's
2812 * count a compaction stall
2814 count_vm_event(COMPACTSTALL
);
2816 page
= get_page_from_freelist(gfp_mask
, order
,
2817 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
2820 struct zone
*zone
= page_zone(page
);
2822 zone
->compact_blockskip_flush
= false;
2823 compaction_defer_reset(zone
, order
, true);
2824 count_vm_event(COMPACTSUCCESS
);
2829 * It's bad if compaction run occurs and fails. The most likely reason
2830 * is that pages exist, but not enough to satisfy watermarks.
2832 count_vm_event(COMPACTFAIL
);
2839 static inline struct page
*
2840 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2841 int alloc_flags
, const struct alloc_context
*ac
,
2842 enum migrate_mode mode
, int *contended_compaction
,
2843 bool *deferred_compaction
)
2847 #endif /* CONFIG_COMPACTION */
2849 /* Perform direct synchronous page reclaim */
2851 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
2852 const struct alloc_context
*ac
)
2854 struct reclaim_state reclaim_state
;
2859 /* We now go into synchronous reclaim */
2860 cpuset_memory_pressure_bump();
2861 current
->flags
|= PF_MEMALLOC
;
2862 lockdep_set_current_reclaim_state(gfp_mask
);
2863 reclaim_state
.reclaimed_slab
= 0;
2864 current
->reclaim_state
= &reclaim_state
;
2866 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
2869 current
->reclaim_state
= NULL
;
2870 lockdep_clear_current_reclaim_state();
2871 current
->flags
&= ~PF_MEMALLOC
;
2878 /* The really slow allocator path where we enter direct reclaim */
2879 static inline struct page
*
2880 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
2881 int alloc_flags
, const struct alloc_context
*ac
,
2882 unsigned long *did_some_progress
)
2884 struct page
*page
= NULL
;
2885 bool drained
= false;
2887 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
2888 if (unlikely(!(*did_some_progress
)))
2892 page
= get_page_from_freelist(gfp_mask
, order
,
2893 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
2896 * If an allocation failed after direct reclaim, it could be because
2897 * pages are pinned on the per-cpu lists or in high alloc reserves.
2898 * Shrink them them and try again
2900 if (!page
&& !drained
) {
2901 unreserve_highatomic_pageblock(ac
);
2902 drain_all_pages(NULL
);
2910 static void wake_all_kswapds(unsigned int order
, const struct alloc_context
*ac
)
2915 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
2916 ac
->high_zoneidx
, ac
->nodemask
)
2917 wakeup_kswapd(zone
, order
, zone_idx(ac
->preferred_zone
));
2921 gfp_to_alloc_flags(gfp_t gfp_mask
)
2923 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
2925 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2926 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
2929 * The caller may dip into page reserves a bit more if the caller
2930 * cannot run direct reclaim, or if the caller has realtime scheduling
2931 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2932 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
2934 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
2936 if (gfp_mask
& __GFP_ATOMIC
) {
2938 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
2939 * if it can't schedule.
2941 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2942 alloc_flags
|= ALLOC_HARDER
;
2944 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
2945 * comment for __cpuset_node_allowed().
2947 alloc_flags
&= ~ALLOC_CPUSET
;
2948 } else if (unlikely(rt_task(current
)) && !in_interrupt())
2949 alloc_flags
|= ALLOC_HARDER
;
2951 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
2952 if (gfp_mask
& __GFP_MEMALLOC
)
2953 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2954 else if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
2955 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2956 else if (!in_interrupt() &&
2957 ((current
->flags
& PF_MEMALLOC
) ||
2958 unlikely(test_thread_flag(TIF_MEMDIE
))))
2959 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2962 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
2963 alloc_flags
|= ALLOC_CMA
;
2968 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
2970 return !!(gfp_to_alloc_flags(gfp_mask
) & ALLOC_NO_WATERMARKS
);
2973 static inline bool is_thp_gfp_mask(gfp_t gfp_mask
)
2975 return (gfp_mask
& (GFP_TRANSHUGE
| __GFP_KSWAPD_RECLAIM
)) == GFP_TRANSHUGE
;
2978 static inline struct page
*
2979 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
2980 struct alloc_context
*ac
)
2982 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
2983 struct page
*page
= NULL
;
2985 unsigned long pages_reclaimed
= 0;
2986 unsigned long did_some_progress
;
2987 enum migrate_mode migration_mode
= MIGRATE_ASYNC
;
2988 bool deferred_compaction
= false;
2989 int contended_compaction
= COMPACT_CONTENDED_NONE
;
2992 * In the slowpath, we sanity check order to avoid ever trying to
2993 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2994 * be using allocators in order of preference for an area that is
2997 if (order
>= MAX_ORDER
) {
2998 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
3003 * We also sanity check to catch abuse of atomic reserves being used by
3004 * callers that are not in atomic context.
3006 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
3007 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
3008 gfp_mask
&= ~__GFP_ATOMIC
;
3011 * If this allocation cannot block and it is for a specific node, then
3012 * fail early. There's no need to wakeup kswapd or retry for a
3013 * speculative node-specific allocation.
3015 if (IS_ENABLED(CONFIG_NUMA
) && (gfp_mask
& __GFP_THISNODE
) && !can_direct_reclaim
)
3019 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3020 wake_all_kswapds(order
, ac
);
3023 * OK, we're below the kswapd watermark and have kicked background
3024 * reclaim. Now things get more complex, so set up alloc_flags according
3025 * to how we want to proceed.
3027 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
3030 * Find the true preferred zone if the allocation is unconstrained by
3033 if (!(alloc_flags
& ALLOC_CPUSET
) && !ac
->nodemask
) {
3034 struct zoneref
*preferred_zoneref
;
3035 preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3036 ac
->high_zoneidx
, NULL
, &ac
->preferred_zone
);
3037 ac
->classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
3040 /* This is the last chance, in general, before the goto nopage. */
3041 page
= get_page_from_freelist(gfp_mask
, order
,
3042 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3046 /* Allocate without watermarks if the context allows */
3047 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
3049 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
3050 * the allocation is high priority and these type of
3051 * allocations are system rather than user orientated
3053 ac
->zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
3054 page
= get_page_from_freelist(gfp_mask
, order
,
3055 ALLOC_NO_WATERMARKS
, ac
);
3060 /* Caller is not willing to reclaim, we can't balance anything */
3061 if (!can_direct_reclaim
) {
3063 * All existing users of the __GFP_NOFAIL are blockable, so warn
3064 * of any new users that actually allow this type of allocation
3067 WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
);
3071 /* Avoid recursion of direct reclaim */
3072 if (current
->flags
& PF_MEMALLOC
) {
3074 * __GFP_NOFAIL request from this context is rather bizarre
3075 * because we cannot reclaim anything and only can loop waiting
3076 * for somebody to do a work for us.
3078 if (WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3085 /* Avoid allocations with no watermarks from looping endlessly */
3086 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
3090 * Try direct compaction. The first pass is asynchronous. Subsequent
3091 * attempts after direct reclaim are synchronous
3093 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
3095 &contended_compaction
,
3096 &deferred_compaction
);
3100 /* Checks for THP-specific high-order allocations */
3101 if (is_thp_gfp_mask(gfp_mask
)) {
3103 * If compaction is deferred for high-order allocations, it is
3104 * because sync compaction recently failed. If this is the case
3105 * and the caller requested a THP allocation, we do not want
3106 * to heavily disrupt the system, so we fail the allocation
3107 * instead of entering direct reclaim.
3109 if (deferred_compaction
)
3113 * In all zones where compaction was attempted (and not
3114 * deferred or skipped), lock contention has been detected.
3115 * For THP allocation we do not want to disrupt the others
3116 * so we fallback to base pages instead.
3118 if (contended_compaction
== COMPACT_CONTENDED_LOCK
)
3122 * If compaction was aborted due to need_resched(), we do not
3123 * want to further increase allocation latency, unless it is
3124 * khugepaged trying to collapse.
3126 if (contended_compaction
== COMPACT_CONTENDED_SCHED
3127 && !(current
->flags
& PF_KTHREAD
))
3132 * It can become very expensive to allocate transparent hugepages at
3133 * fault, so use asynchronous memory compaction for THP unless it is
3134 * khugepaged trying to collapse.
3136 if (!is_thp_gfp_mask(gfp_mask
) || (current
->flags
& PF_KTHREAD
))
3137 migration_mode
= MIGRATE_SYNC_LIGHT
;
3139 /* Try direct reclaim and then allocating */
3140 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
3141 &did_some_progress
);
3145 /* Do not loop if specifically requested */
3146 if (gfp_mask
& __GFP_NORETRY
)
3149 /* Keep reclaiming pages as long as there is reasonable progress */
3150 pages_reclaimed
+= did_some_progress
;
3151 if ((did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
) ||
3152 ((gfp_mask
& __GFP_REPEAT
) && pages_reclaimed
< (1 << order
))) {
3153 /* Wait for some write requests to complete then retry */
3154 wait_iff_congested(ac
->preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
3158 /* Reclaim has failed us, start killing things */
3159 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
3163 /* Retry as long as the OOM killer is making progress */
3164 if (did_some_progress
)
3169 * High-order allocations do not necessarily loop after
3170 * direct reclaim and reclaim/compaction depends on compaction
3171 * being called after reclaim so call directly if necessary
3173 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
,
3175 &contended_compaction
,
3176 &deferred_compaction
);
3180 warn_alloc_failed(gfp_mask
, order
, NULL
);
3186 * This is the 'heart' of the zoned buddy allocator.
3189 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
3190 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
3192 struct zoneref
*preferred_zoneref
;
3193 struct page
*page
= NULL
;
3194 unsigned int cpuset_mems_cookie
;
3195 int alloc_flags
= ALLOC_WMARK_LOW
|ALLOC_CPUSET
|ALLOC_FAIR
;
3196 gfp_t alloc_mask
; /* The gfp_t that was actually used for allocation */
3197 struct alloc_context ac
= {
3198 .high_zoneidx
= gfp_zone(gfp_mask
),
3199 .nodemask
= nodemask
,
3200 .migratetype
= gfpflags_to_migratetype(gfp_mask
),
3203 gfp_mask
&= gfp_allowed_mask
;
3205 lockdep_trace_alloc(gfp_mask
);
3207 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
3209 if (should_fail_alloc_page(gfp_mask
, order
))
3213 * Check the zones suitable for the gfp_mask contain at least one
3214 * valid zone. It's possible to have an empty zonelist as a result
3215 * of __GFP_THISNODE and a memoryless node
3217 if (unlikely(!zonelist
->_zonerefs
->zone
))
3220 if (IS_ENABLED(CONFIG_CMA
) && ac
.migratetype
== MIGRATE_MOVABLE
)
3221 alloc_flags
|= ALLOC_CMA
;
3224 cpuset_mems_cookie
= read_mems_allowed_begin();
3226 /* We set it here, as __alloc_pages_slowpath might have changed it */
3227 ac
.zonelist
= zonelist
;
3229 /* Dirty zone balancing only done in the fast path */
3230 ac
.spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
3232 /* The preferred zone is used for statistics later */
3233 preferred_zoneref
= first_zones_zonelist(ac
.zonelist
, ac
.high_zoneidx
,
3234 ac
.nodemask
? : &cpuset_current_mems_allowed
,
3235 &ac
.preferred_zone
);
3236 if (!ac
.preferred_zone
)
3238 ac
.classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
3240 /* First allocation attempt */
3241 alloc_mask
= gfp_mask
|__GFP_HARDWALL
;
3242 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
3243 if (unlikely(!page
)) {
3245 * Runtime PM, block IO and its error handling path
3246 * can deadlock because I/O on the device might not
3249 alloc_mask
= memalloc_noio_flags(gfp_mask
);
3250 ac
.spread_dirty_pages
= false;
3252 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
3255 if (kmemcheck_enabled
&& page
)
3256 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
3258 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
3262 * When updating a task's mems_allowed, it is possible to race with
3263 * parallel threads in such a way that an allocation can fail while
3264 * the mask is being updated. If a page allocation is about to fail,
3265 * check if the cpuset changed during allocation and if so, retry.
3267 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
)))
3272 EXPORT_SYMBOL(__alloc_pages_nodemask
);
3275 * Common helper functions.
3277 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
3282 * __get_free_pages() returns a 32-bit address, which cannot represent
3285 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
3287 page
= alloc_pages(gfp_mask
, order
);
3290 return (unsigned long) page_address(page
);
3292 EXPORT_SYMBOL(__get_free_pages
);
3294 unsigned long get_zeroed_page(gfp_t gfp_mask
)
3296 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
3298 EXPORT_SYMBOL(get_zeroed_page
);
3300 void __free_pages(struct page
*page
, unsigned int order
)
3302 if (put_page_testzero(page
)) {
3304 free_hot_cold_page(page
, false);
3306 __free_pages_ok(page
, order
);
3310 EXPORT_SYMBOL(__free_pages
);
3312 void free_pages(unsigned long addr
, unsigned int order
)
3315 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3316 __free_pages(virt_to_page((void *)addr
), order
);
3320 EXPORT_SYMBOL(free_pages
);
3324 * An arbitrary-length arbitrary-offset area of memory which resides
3325 * within a 0 or higher order page. Multiple fragments within that page
3326 * are individually refcounted, in the page's reference counter.
3328 * The page_frag functions below provide a simple allocation framework for
3329 * page fragments. This is used by the network stack and network device
3330 * drivers to provide a backing region of memory for use as either an
3331 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3333 static struct page
*__page_frag_refill(struct page_frag_cache
*nc
,
3336 struct page
*page
= NULL
;
3337 gfp_t gfp
= gfp_mask
;
3339 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3340 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
3342 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
3343 PAGE_FRAG_CACHE_MAX_ORDER
);
3344 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
3346 if (unlikely(!page
))
3347 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
3349 nc
->va
= page
? page_address(page
) : NULL
;
3354 void *__alloc_page_frag(struct page_frag_cache
*nc
,
3355 unsigned int fragsz
, gfp_t gfp_mask
)
3357 unsigned int size
= PAGE_SIZE
;
3361 if (unlikely(!nc
->va
)) {
3363 page
= __page_frag_refill(nc
, gfp_mask
);
3367 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3368 /* if size can vary use size else just use PAGE_SIZE */
3371 /* Even if we own the page, we do not use atomic_set().
3372 * This would break get_page_unless_zero() users.
3374 atomic_add(size
- 1, &page
->_count
);
3376 /* reset page count bias and offset to start of new frag */
3377 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
3378 nc
->pagecnt_bias
= size
;
3382 offset
= nc
->offset
- fragsz
;
3383 if (unlikely(offset
< 0)) {
3384 page
= virt_to_page(nc
->va
);
3386 if (!atomic_sub_and_test(nc
->pagecnt_bias
, &page
->_count
))
3389 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3390 /* if size can vary use size else just use PAGE_SIZE */
3393 /* OK, page count is 0, we can safely set it */
3394 atomic_set(&page
->_count
, size
);
3396 /* reset page count bias and offset to start of new frag */
3397 nc
->pagecnt_bias
= size
;
3398 offset
= size
- fragsz
;
3402 nc
->offset
= offset
;
3404 return nc
->va
+ offset
;
3406 EXPORT_SYMBOL(__alloc_page_frag
);
3409 * Frees a page fragment allocated out of either a compound or order 0 page.
3411 void __free_page_frag(void *addr
)
3413 struct page
*page
= virt_to_head_page(addr
);
3415 if (unlikely(put_page_testzero(page
)))
3416 __free_pages_ok(page
, compound_order(page
));
3418 EXPORT_SYMBOL(__free_page_frag
);
3421 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
3422 * of the current memory cgroup if __GFP_ACCOUNT is set, other than that it is
3423 * equivalent to alloc_pages.
3425 * It should be used when the caller would like to use kmalloc, but since the
3426 * allocation is large, it has to fall back to the page allocator.
3428 struct page
*alloc_kmem_pages(gfp_t gfp_mask
, unsigned int order
)
3432 page
= alloc_pages(gfp_mask
, order
);
3433 if (page
&& memcg_kmem_charge(page
, gfp_mask
, order
) != 0) {
3434 __free_pages(page
, order
);
3440 struct page
*alloc_kmem_pages_node(int nid
, gfp_t gfp_mask
, unsigned int order
)
3444 page
= alloc_pages_node(nid
, gfp_mask
, order
);
3445 if (page
&& memcg_kmem_charge(page
, gfp_mask
, order
) != 0) {
3446 __free_pages(page
, order
);
3453 * __free_kmem_pages and free_kmem_pages will free pages allocated with
3456 void __free_kmem_pages(struct page
*page
, unsigned int order
)
3458 memcg_kmem_uncharge(page
, order
);
3459 __free_pages(page
, order
);
3462 void free_kmem_pages(unsigned long addr
, unsigned int order
)
3465 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3466 __free_kmem_pages(virt_to_page((void *)addr
), order
);
3470 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
3474 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
3475 unsigned long used
= addr
+ PAGE_ALIGN(size
);
3477 split_page(virt_to_page((void *)addr
), order
);
3478 while (used
< alloc_end
) {
3483 return (void *)addr
;
3487 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
3488 * @size: the number of bytes to allocate
3489 * @gfp_mask: GFP flags for the allocation
3491 * This function is similar to alloc_pages(), except that it allocates the
3492 * minimum number of pages to satisfy the request. alloc_pages() can only
3493 * allocate memory in power-of-two pages.
3495 * This function is also limited by MAX_ORDER.
3497 * Memory allocated by this function must be released by free_pages_exact().
3499 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
3501 unsigned int order
= get_order(size
);
3504 addr
= __get_free_pages(gfp_mask
, order
);
3505 return make_alloc_exact(addr
, order
, size
);
3507 EXPORT_SYMBOL(alloc_pages_exact
);
3510 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3512 * @nid: the preferred node ID where memory should be allocated
3513 * @size: the number of bytes to allocate
3514 * @gfp_mask: GFP flags for the allocation
3516 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3519 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
3521 unsigned int order
= get_order(size
);
3522 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
3525 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
3529 * free_pages_exact - release memory allocated via alloc_pages_exact()
3530 * @virt: the value returned by alloc_pages_exact.
3531 * @size: size of allocation, same value as passed to alloc_pages_exact().
3533 * Release the memory allocated by a previous call to alloc_pages_exact.
3535 void free_pages_exact(void *virt
, size_t size
)
3537 unsigned long addr
= (unsigned long)virt
;
3538 unsigned long end
= addr
+ PAGE_ALIGN(size
);
3540 while (addr
< end
) {
3545 EXPORT_SYMBOL(free_pages_exact
);
3548 * nr_free_zone_pages - count number of pages beyond high watermark
3549 * @offset: The zone index of the highest zone
3551 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3552 * high watermark within all zones at or below a given zone index. For each
3553 * zone, the number of pages is calculated as:
3554 * managed_pages - high_pages
3556 static unsigned long nr_free_zone_pages(int offset
)
3561 /* Just pick one node, since fallback list is circular */
3562 unsigned long sum
= 0;
3564 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
3566 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
3567 unsigned long size
= zone
->managed_pages
;
3568 unsigned long high
= high_wmark_pages(zone
);
3577 * nr_free_buffer_pages - count number of pages beyond high watermark
3579 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3580 * watermark within ZONE_DMA and ZONE_NORMAL.
3582 unsigned long nr_free_buffer_pages(void)
3584 return nr_free_zone_pages(gfp_zone(GFP_USER
));
3586 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
3589 * nr_free_pagecache_pages - count number of pages beyond high watermark
3591 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3592 * high watermark within all zones.
3594 unsigned long nr_free_pagecache_pages(void)
3596 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
3599 static inline void show_node(struct zone
*zone
)
3601 if (IS_ENABLED(CONFIG_NUMA
))
3602 printk("Node %d ", zone_to_nid(zone
));
3605 void si_meminfo(struct sysinfo
*val
)
3607 val
->totalram
= totalram_pages
;
3608 val
->sharedram
= global_page_state(NR_SHMEM
);
3609 val
->freeram
= global_page_state(NR_FREE_PAGES
);
3610 val
->bufferram
= nr_blockdev_pages();
3611 val
->totalhigh
= totalhigh_pages
;
3612 val
->freehigh
= nr_free_highpages();
3613 val
->mem_unit
= PAGE_SIZE
;
3616 EXPORT_SYMBOL(si_meminfo
);
3619 void si_meminfo_node(struct sysinfo
*val
, int nid
)
3621 int zone_type
; /* needs to be signed */
3622 unsigned long managed_pages
= 0;
3623 pg_data_t
*pgdat
= NODE_DATA(nid
);
3625 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
3626 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
3627 val
->totalram
= managed_pages
;
3628 val
->sharedram
= node_page_state(nid
, NR_SHMEM
);
3629 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
3630 #ifdef CONFIG_HIGHMEM
3631 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].managed_pages
;
3632 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
3638 val
->mem_unit
= PAGE_SIZE
;
3643 * Determine whether the node should be displayed or not, depending on whether
3644 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3646 bool skip_free_areas_node(unsigned int flags
, int nid
)
3649 unsigned int cpuset_mems_cookie
;
3651 if (!(flags
& SHOW_MEM_FILTER_NODES
))
3655 cpuset_mems_cookie
= read_mems_allowed_begin();
3656 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
3657 } while (read_mems_allowed_retry(cpuset_mems_cookie
));
3662 #define K(x) ((x) << (PAGE_SHIFT-10))
3664 static void show_migration_types(unsigned char type
)
3666 static const char types
[MIGRATE_TYPES
] = {
3667 [MIGRATE_UNMOVABLE
] = 'U',
3668 [MIGRATE_MOVABLE
] = 'M',
3669 [MIGRATE_RECLAIMABLE
] = 'E',
3670 [MIGRATE_HIGHATOMIC
] = 'H',
3672 [MIGRATE_CMA
] = 'C',
3674 #ifdef CONFIG_MEMORY_ISOLATION
3675 [MIGRATE_ISOLATE
] = 'I',
3678 char tmp
[MIGRATE_TYPES
+ 1];
3682 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
3683 if (type
& (1 << i
))
3688 printk("(%s) ", tmp
);
3692 * Show free area list (used inside shift_scroll-lock stuff)
3693 * We also calculate the percentage fragmentation. We do this by counting the
3694 * memory on each free list with the exception of the first item on the list.
3697 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
3700 void show_free_areas(unsigned int filter
)
3702 unsigned long free_pcp
= 0;
3706 for_each_populated_zone(zone
) {
3707 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3710 for_each_online_cpu(cpu
)
3711 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
3714 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3715 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3716 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
3717 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3718 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3719 " free:%lu free_pcp:%lu free_cma:%lu\n",
3720 global_page_state(NR_ACTIVE_ANON
),
3721 global_page_state(NR_INACTIVE_ANON
),
3722 global_page_state(NR_ISOLATED_ANON
),
3723 global_page_state(NR_ACTIVE_FILE
),
3724 global_page_state(NR_INACTIVE_FILE
),
3725 global_page_state(NR_ISOLATED_FILE
),
3726 global_page_state(NR_UNEVICTABLE
),
3727 global_page_state(NR_FILE_DIRTY
),
3728 global_page_state(NR_WRITEBACK
),
3729 global_page_state(NR_UNSTABLE_NFS
),
3730 global_page_state(NR_SLAB_RECLAIMABLE
),
3731 global_page_state(NR_SLAB_UNRECLAIMABLE
),
3732 global_page_state(NR_FILE_MAPPED
),
3733 global_page_state(NR_SHMEM
),
3734 global_page_state(NR_PAGETABLE
),
3735 global_page_state(NR_BOUNCE
),
3736 global_page_state(NR_FREE_PAGES
),
3738 global_page_state(NR_FREE_CMA_PAGES
));
3740 for_each_populated_zone(zone
) {
3743 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3747 for_each_online_cpu(cpu
)
3748 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
3756 " active_anon:%lukB"
3757 " inactive_anon:%lukB"
3758 " active_file:%lukB"
3759 " inactive_file:%lukB"
3760 " unevictable:%lukB"
3761 " isolated(anon):%lukB"
3762 " isolated(file):%lukB"
3770 " slab_reclaimable:%lukB"
3771 " slab_unreclaimable:%lukB"
3772 " kernel_stack:%lukB"
3779 " writeback_tmp:%lukB"
3780 " pages_scanned:%lu"
3781 " all_unreclaimable? %s"
3784 K(zone_page_state(zone
, NR_FREE_PAGES
)),
3785 K(min_wmark_pages(zone
)),
3786 K(low_wmark_pages(zone
)),
3787 K(high_wmark_pages(zone
)),
3788 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
3789 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
3790 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
3791 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
3792 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
3793 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
3794 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
3795 K(zone
->present_pages
),
3796 K(zone
->managed_pages
),
3797 K(zone_page_state(zone
, NR_MLOCK
)),
3798 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
3799 K(zone_page_state(zone
, NR_WRITEBACK
)),
3800 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
3801 K(zone_page_state(zone
, NR_SHMEM
)),
3802 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
3803 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
3804 zone_page_state(zone
, NR_KERNEL_STACK
) *
3806 K(zone_page_state(zone
, NR_PAGETABLE
)),
3807 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
3808 K(zone_page_state(zone
, NR_BOUNCE
)),
3810 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
3811 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)),
3812 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
3813 K(zone_page_state(zone
, NR_PAGES_SCANNED
)),
3814 (!zone_reclaimable(zone
) ? "yes" : "no")
3816 printk("lowmem_reserve[]:");
3817 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3818 printk(" %ld", zone
->lowmem_reserve
[i
]);
3822 for_each_populated_zone(zone
) {
3824 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
3825 unsigned char types
[MAX_ORDER
];
3827 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3830 printk("%s: ", zone
->name
);
3832 spin_lock_irqsave(&zone
->lock
, flags
);
3833 for (order
= 0; order
< MAX_ORDER
; order
++) {
3834 struct free_area
*area
= &zone
->free_area
[order
];
3837 nr
[order
] = area
->nr_free
;
3838 total
+= nr
[order
] << order
;
3841 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
3842 if (!list_empty(&area
->free_list
[type
]))
3843 types
[order
] |= 1 << type
;
3846 spin_unlock_irqrestore(&zone
->lock
, flags
);
3847 for (order
= 0; order
< MAX_ORDER
; order
++) {
3848 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
3850 show_migration_types(types
[order
]);
3852 printk("= %lukB\n", K(total
));
3855 hugetlb_show_meminfo();
3857 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
3859 show_swap_cache_info();
3862 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
3864 zoneref
->zone
= zone
;
3865 zoneref
->zone_idx
= zone_idx(zone
);
3869 * Builds allocation fallback zone lists.
3871 * Add all populated zones of a node to the zonelist.
3873 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
3877 enum zone_type zone_type
= MAX_NR_ZONES
;
3881 zone
= pgdat
->node_zones
+ zone_type
;
3882 if (populated_zone(zone
)) {
3883 zoneref_set_zone(zone
,
3884 &zonelist
->_zonerefs
[nr_zones
++]);
3885 check_highest_zone(zone_type
);
3887 } while (zone_type
);
3895 * 0 = automatic detection of better ordering.
3896 * 1 = order by ([node] distance, -zonetype)
3897 * 2 = order by (-zonetype, [node] distance)
3899 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3900 * the same zonelist. So only NUMA can configure this param.
3902 #define ZONELIST_ORDER_DEFAULT 0
3903 #define ZONELIST_ORDER_NODE 1
3904 #define ZONELIST_ORDER_ZONE 2
3906 /* zonelist order in the kernel.
3907 * set_zonelist_order() will set this to NODE or ZONE.
3909 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3910 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
3914 /* The value user specified ....changed by config */
3915 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3916 /* string for sysctl */
3917 #define NUMA_ZONELIST_ORDER_LEN 16
3918 char numa_zonelist_order
[16] = "default";
3921 * interface for configure zonelist ordering.
3922 * command line option "numa_zonelist_order"
3923 * = "[dD]efault - default, automatic configuration.
3924 * = "[nN]ode - order by node locality, then by zone within node
3925 * = "[zZ]one - order by zone, then by locality within zone
3928 static int __parse_numa_zonelist_order(char *s
)
3930 if (*s
== 'd' || *s
== 'D') {
3931 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3932 } else if (*s
== 'n' || *s
== 'N') {
3933 user_zonelist_order
= ZONELIST_ORDER_NODE
;
3934 } else if (*s
== 'z' || *s
== 'Z') {
3935 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
3938 "Ignoring invalid numa_zonelist_order value: "
3945 static __init
int setup_numa_zonelist_order(char *s
)
3952 ret
= __parse_numa_zonelist_order(s
);
3954 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
3958 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
3961 * sysctl handler for numa_zonelist_order
3963 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
3964 void __user
*buffer
, size_t *length
,
3967 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
3969 static DEFINE_MUTEX(zl_order_mutex
);
3971 mutex_lock(&zl_order_mutex
);
3973 if (strlen((char *)table
->data
) >= NUMA_ZONELIST_ORDER_LEN
) {
3977 strcpy(saved_string
, (char *)table
->data
);
3979 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
3983 int oldval
= user_zonelist_order
;
3985 ret
= __parse_numa_zonelist_order((char *)table
->data
);
3988 * bogus value. restore saved string
3990 strncpy((char *)table
->data
, saved_string
,
3991 NUMA_ZONELIST_ORDER_LEN
);
3992 user_zonelist_order
= oldval
;
3993 } else if (oldval
!= user_zonelist_order
) {
3994 mutex_lock(&zonelists_mutex
);
3995 build_all_zonelists(NULL
, NULL
);
3996 mutex_unlock(&zonelists_mutex
);
4000 mutex_unlock(&zl_order_mutex
);
4005 #define MAX_NODE_LOAD (nr_online_nodes)
4006 static int node_load
[MAX_NUMNODES
];
4009 * find_next_best_node - find the next node that should appear in a given node's fallback list
4010 * @node: node whose fallback list we're appending
4011 * @used_node_mask: nodemask_t of already used nodes
4013 * We use a number of factors to determine which is the next node that should
4014 * appear on a given node's fallback list. The node should not have appeared
4015 * already in @node's fallback list, and it should be the next closest node
4016 * according to the distance array (which contains arbitrary distance values
4017 * from each node to each node in the system), and should also prefer nodes
4018 * with no CPUs, since presumably they'll have very little allocation pressure
4019 * on them otherwise.
4020 * It returns -1 if no node is found.
4022 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
4025 int min_val
= INT_MAX
;
4026 int best_node
= NUMA_NO_NODE
;
4027 const struct cpumask
*tmp
= cpumask_of_node(0);
4029 /* Use the local node if we haven't already */
4030 if (!node_isset(node
, *used_node_mask
)) {
4031 node_set(node
, *used_node_mask
);
4035 for_each_node_state(n
, N_MEMORY
) {
4037 /* Don't want a node to appear more than once */
4038 if (node_isset(n
, *used_node_mask
))
4041 /* Use the distance array to find the distance */
4042 val
= node_distance(node
, n
);
4044 /* Penalize nodes under us ("prefer the next node") */
4047 /* Give preference to headless and unused nodes */
4048 tmp
= cpumask_of_node(n
);
4049 if (!cpumask_empty(tmp
))
4050 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
4052 /* Slight preference for less loaded node */
4053 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
4054 val
+= node_load
[n
];
4056 if (val
< min_val
) {
4063 node_set(best_node
, *used_node_mask
);
4070 * Build zonelists ordered by node and zones within node.
4071 * This results in maximum locality--normal zone overflows into local
4072 * DMA zone, if any--but risks exhausting DMA zone.
4074 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
4077 struct zonelist
*zonelist
;
4079 zonelist
= &pgdat
->node_zonelists
[0];
4080 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
4082 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4083 zonelist
->_zonerefs
[j
].zone
= NULL
;
4084 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4088 * Build gfp_thisnode zonelists
4090 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
4093 struct zonelist
*zonelist
;
4095 zonelist
= &pgdat
->node_zonelists
[1];
4096 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4097 zonelist
->_zonerefs
[j
].zone
= NULL
;
4098 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4102 * Build zonelists ordered by zone and nodes within zones.
4103 * This results in conserving DMA zone[s] until all Normal memory is
4104 * exhausted, but results in overflowing to remote node while memory
4105 * may still exist in local DMA zone.
4107 static int node_order
[MAX_NUMNODES
];
4109 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
4112 int zone_type
; /* needs to be signed */
4114 struct zonelist
*zonelist
;
4116 zonelist
= &pgdat
->node_zonelists
[0];
4118 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
4119 for (j
= 0; j
< nr_nodes
; j
++) {
4120 node
= node_order
[j
];
4121 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
4122 if (populated_zone(z
)) {
4124 &zonelist
->_zonerefs
[pos
++]);
4125 check_highest_zone(zone_type
);
4129 zonelist
->_zonerefs
[pos
].zone
= NULL
;
4130 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
4133 #if defined(CONFIG_64BIT)
4135 * Devices that require DMA32/DMA are relatively rare and do not justify a
4136 * penalty to every machine in case the specialised case applies. Default
4137 * to Node-ordering on 64-bit NUMA machines
4139 static int default_zonelist_order(void)
4141 return ZONELIST_ORDER_NODE
;
4145 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4146 * by the kernel. If processes running on node 0 deplete the low memory zone
4147 * then reclaim will occur more frequency increasing stalls and potentially
4148 * be easier to OOM if a large percentage of the zone is under writeback or
4149 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4150 * Hence, default to zone ordering on 32-bit.
4152 static int default_zonelist_order(void)
4154 return ZONELIST_ORDER_ZONE
;
4156 #endif /* CONFIG_64BIT */
4158 static void set_zonelist_order(void)
4160 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
4161 current_zonelist_order
= default_zonelist_order();
4163 current_zonelist_order
= user_zonelist_order
;
4166 static void build_zonelists(pg_data_t
*pgdat
)
4169 nodemask_t used_mask
;
4170 int local_node
, prev_node
;
4171 struct zonelist
*zonelist
;
4172 unsigned int order
= current_zonelist_order
;
4174 /* initialize zonelists */
4175 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
4176 zonelist
= pgdat
->node_zonelists
+ i
;
4177 zonelist
->_zonerefs
[0].zone
= NULL
;
4178 zonelist
->_zonerefs
[0].zone_idx
= 0;
4181 /* NUMA-aware ordering of nodes */
4182 local_node
= pgdat
->node_id
;
4183 load
= nr_online_nodes
;
4184 prev_node
= local_node
;
4185 nodes_clear(used_mask
);
4187 memset(node_order
, 0, sizeof(node_order
));
4190 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
4192 * We don't want to pressure a particular node.
4193 * So adding penalty to the first node in same
4194 * distance group to make it round-robin.
4196 if (node_distance(local_node
, node
) !=
4197 node_distance(local_node
, prev_node
))
4198 node_load
[node
] = load
;
4202 if (order
== ZONELIST_ORDER_NODE
)
4203 build_zonelists_in_node_order(pgdat
, node
);
4205 node_order
[i
++] = node
; /* remember order */
4208 if (order
== ZONELIST_ORDER_ZONE
) {
4209 /* calculate node order -- i.e., DMA last! */
4210 build_zonelists_in_zone_order(pgdat
, i
);
4213 build_thisnode_zonelists(pgdat
);
4216 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4218 * Return node id of node used for "local" allocations.
4219 * I.e., first node id of first zone in arg node's generic zonelist.
4220 * Used for initializing percpu 'numa_mem', which is used primarily
4221 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4223 int local_memory_node(int node
)
4227 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
4228 gfp_zone(GFP_KERNEL
),
4235 #else /* CONFIG_NUMA */
4237 static void set_zonelist_order(void)
4239 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
4242 static void build_zonelists(pg_data_t
*pgdat
)
4244 int node
, local_node
;
4246 struct zonelist
*zonelist
;
4248 local_node
= pgdat
->node_id
;
4250 zonelist
= &pgdat
->node_zonelists
[0];
4251 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4254 * Now we build the zonelist so that it contains the zones
4255 * of all the other nodes.
4256 * We don't want to pressure a particular node, so when
4257 * building the zones for node N, we make sure that the
4258 * zones coming right after the local ones are those from
4259 * node N+1 (modulo N)
4261 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
4262 if (!node_online(node
))
4264 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4266 for (node
= 0; node
< local_node
; node
++) {
4267 if (!node_online(node
))
4269 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4272 zonelist
->_zonerefs
[j
].zone
= NULL
;
4273 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4276 #endif /* CONFIG_NUMA */
4279 * Boot pageset table. One per cpu which is going to be used for all
4280 * zones and all nodes. The parameters will be set in such a way
4281 * that an item put on a list will immediately be handed over to
4282 * the buddy list. This is safe since pageset manipulation is done
4283 * with interrupts disabled.
4285 * The boot_pagesets must be kept even after bootup is complete for
4286 * unused processors and/or zones. They do play a role for bootstrapping
4287 * hotplugged processors.
4289 * zoneinfo_show() and maybe other functions do
4290 * not check if the processor is online before following the pageset pointer.
4291 * Other parts of the kernel may not check if the zone is available.
4293 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
4294 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
4295 static void setup_zone_pageset(struct zone
*zone
);
4298 * Global mutex to protect against size modification of zonelists
4299 * as well as to serialize pageset setup for the new populated zone.
4301 DEFINE_MUTEX(zonelists_mutex
);
4303 /* return values int ....just for stop_machine() */
4304 static int __build_all_zonelists(void *data
)
4308 pg_data_t
*self
= data
;
4311 memset(node_load
, 0, sizeof(node_load
));
4314 if (self
&& !node_online(self
->node_id
)) {
4315 build_zonelists(self
);
4318 for_each_online_node(nid
) {
4319 pg_data_t
*pgdat
= NODE_DATA(nid
);
4321 build_zonelists(pgdat
);
4325 * Initialize the boot_pagesets that are going to be used
4326 * for bootstrapping processors. The real pagesets for
4327 * each zone will be allocated later when the per cpu
4328 * allocator is available.
4330 * boot_pagesets are used also for bootstrapping offline
4331 * cpus if the system is already booted because the pagesets
4332 * are needed to initialize allocators on a specific cpu too.
4333 * F.e. the percpu allocator needs the page allocator which
4334 * needs the percpu allocator in order to allocate its pagesets
4335 * (a chicken-egg dilemma).
4337 for_each_possible_cpu(cpu
) {
4338 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
4340 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4342 * We now know the "local memory node" for each node--
4343 * i.e., the node of the first zone in the generic zonelist.
4344 * Set up numa_mem percpu variable for on-line cpus. During
4345 * boot, only the boot cpu should be on-line; we'll init the
4346 * secondary cpus' numa_mem as they come on-line. During
4347 * node/memory hotplug, we'll fixup all on-line cpus.
4349 if (cpu_online(cpu
))
4350 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
4357 static noinline
void __init
4358 build_all_zonelists_init(void)
4360 __build_all_zonelists(NULL
);
4361 mminit_verify_zonelist();
4362 cpuset_init_current_mems_allowed();
4366 * Called with zonelists_mutex held always
4367 * unless system_state == SYSTEM_BOOTING.
4369 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4370 * [we're only called with non-NULL zone through __meminit paths] and
4371 * (2) call of __init annotated helper build_all_zonelists_init
4372 * [protected by SYSTEM_BOOTING].
4374 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
4376 set_zonelist_order();
4378 if (system_state
== SYSTEM_BOOTING
) {
4379 build_all_zonelists_init();
4381 #ifdef CONFIG_MEMORY_HOTPLUG
4383 setup_zone_pageset(zone
);
4385 /* we have to stop all cpus to guarantee there is no user
4387 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
4388 /* cpuset refresh routine should be here */
4390 vm_total_pages
= nr_free_pagecache_pages();
4392 * Disable grouping by mobility if the number of pages in the
4393 * system is too low to allow the mechanism to work. It would be
4394 * more accurate, but expensive to check per-zone. This check is
4395 * made on memory-hotadd so a system can start with mobility
4396 * disabled and enable it later
4398 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
4399 page_group_by_mobility_disabled
= 1;
4401 page_group_by_mobility_disabled
= 0;
4403 pr_info("Built %i zonelists in %s order, mobility grouping %s. "
4404 "Total pages: %ld\n",
4406 zonelist_order_name
[current_zonelist_order
],
4407 page_group_by_mobility_disabled
? "off" : "on",
4410 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
4415 * Helper functions to size the waitqueue hash table.
4416 * Essentially these want to choose hash table sizes sufficiently
4417 * large so that collisions trying to wait on pages are rare.
4418 * But in fact, the number of active page waitqueues on typical
4419 * systems is ridiculously low, less than 200. So this is even
4420 * conservative, even though it seems large.
4422 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
4423 * waitqueues, i.e. the size of the waitq table given the number of pages.
4425 #define PAGES_PER_WAITQUEUE 256
4427 #ifndef CONFIG_MEMORY_HOTPLUG
4428 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
4430 unsigned long size
= 1;
4432 pages
/= PAGES_PER_WAITQUEUE
;
4434 while (size
< pages
)
4438 * Once we have dozens or even hundreds of threads sleeping
4439 * on IO we've got bigger problems than wait queue collision.
4440 * Limit the size of the wait table to a reasonable size.
4442 size
= min(size
, 4096UL);
4444 return max(size
, 4UL);
4448 * A zone's size might be changed by hot-add, so it is not possible to determine
4449 * a suitable size for its wait_table. So we use the maximum size now.
4451 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
4453 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
4454 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
4455 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
4457 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
4458 * or more by the traditional way. (See above). It equals:
4460 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
4461 * ia64(16K page size) : = ( 8G + 4M)byte.
4462 * powerpc (64K page size) : = (32G +16M)byte.
4464 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
4471 * This is an integer logarithm so that shifts can be used later
4472 * to extract the more random high bits from the multiplicative
4473 * hash function before the remainder is taken.
4475 static inline unsigned long wait_table_bits(unsigned long size
)
4481 * Initially all pages are reserved - free ones are freed
4482 * up by free_all_bootmem() once the early boot process is
4483 * done. Non-atomic initialization, single-pass.
4485 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
4486 unsigned long start_pfn
, enum memmap_context context
)
4488 pg_data_t
*pgdat
= NODE_DATA(nid
);
4489 unsigned long end_pfn
= start_pfn
+ size
;
4492 unsigned long nr_initialised
= 0;
4494 if (highest_memmap_pfn
< end_pfn
- 1)
4495 highest_memmap_pfn
= end_pfn
- 1;
4497 z
= &pgdat
->node_zones
[zone
];
4498 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
4500 * There can be holes in boot-time mem_map[]s
4501 * handed to this function. They do not
4502 * exist on hotplugged memory.
4504 if (context
== MEMMAP_EARLY
) {
4505 if (!early_pfn_valid(pfn
))
4507 if (!early_pfn_in_nid(pfn
, nid
))
4509 if (!update_defer_init(pgdat
, pfn
, end_pfn
,
4515 * Mark the block movable so that blocks are reserved for
4516 * movable at startup. This will force kernel allocations
4517 * to reserve their blocks rather than leaking throughout
4518 * the address space during boot when many long-lived
4519 * kernel allocations are made.
4521 * bitmap is created for zone's valid pfn range. but memmap
4522 * can be created for invalid pages (for alignment)
4523 * check here not to call set_pageblock_migratetype() against
4526 if (!(pfn
& (pageblock_nr_pages
- 1))) {
4527 struct page
*page
= pfn_to_page(pfn
);
4529 __init_single_page(page
, pfn
, zone
, nid
);
4530 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4532 __init_single_pfn(pfn
, zone
, nid
);
4537 static void __meminit
zone_init_free_lists(struct zone
*zone
)
4539 unsigned int order
, t
;
4540 for_each_migratetype_order(order
, t
) {
4541 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
4542 zone
->free_area
[order
].nr_free
= 0;
4546 #ifndef __HAVE_ARCH_MEMMAP_INIT
4547 #define memmap_init(size, nid, zone, start_pfn) \
4548 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4551 static int zone_batchsize(struct zone
*zone
)
4557 * The per-cpu-pages pools are set to around 1000th of the
4558 * size of the zone. But no more than 1/2 of a meg.
4560 * OK, so we don't know how big the cache is. So guess.
4562 batch
= zone
->managed_pages
/ 1024;
4563 if (batch
* PAGE_SIZE
> 512 * 1024)
4564 batch
= (512 * 1024) / PAGE_SIZE
;
4565 batch
/= 4; /* We effectively *= 4 below */
4570 * Clamp the batch to a 2^n - 1 value. Having a power
4571 * of 2 value was found to be more likely to have
4572 * suboptimal cache aliasing properties in some cases.
4574 * For example if 2 tasks are alternately allocating
4575 * batches of pages, one task can end up with a lot
4576 * of pages of one half of the possible page colors
4577 * and the other with pages of the other colors.
4579 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
4584 /* The deferral and batching of frees should be suppressed under NOMMU
4587 * The problem is that NOMMU needs to be able to allocate large chunks
4588 * of contiguous memory as there's no hardware page translation to
4589 * assemble apparent contiguous memory from discontiguous pages.
4591 * Queueing large contiguous runs of pages for batching, however,
4592 * causes the pages to actually be freed in smaller chunks. As there
4593 * can be a significant delay between the individual batches being
4594 * recycled, this leads to the once large chunks of space being
4595 * fragmented and becoming unavailable for high-order allocations.
4602 * pcp->high and pcp->batch values are related and dependent on one another:
4603 * ->batch must never be higher then ->high.
4604 * The following function updates them in a safe manner without read side
4607 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4608 * those fields changing asynchronously (acording the the above rule).
4610 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4611 * outside of boot time (or some other assurance that no concurrent updaters
4614 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
4615 unsigned long batch
)
4617 /* start with a fail safe value for batch */
4621 /* Update high, then batch, in order */
4628 /* a companion to pageset_set_high() */
4629 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
4631 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
4634 static void pageset_init(struct per_cpu_pageset
*p
)
4636 struct per_cpu_pages
*pcp
;
4639 memset(p
, 0, sizeof(*p
));
4643 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
4644 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
4647 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
4650 pageset_set_batch(p
, batch
);
4654 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4655 * to the value high for the pageset p.
4657 static void pageset_set_high(struct per_cpu_pageset
*p
,
4660 unsigned long batch
= max(1UL, high
/ 4);
4661 if ((high
/ 4) > (PAGE_SHIFT
* 8))
4662 batch
= PAGE_SHIFT
* 8;
4664 pageset_update(&p
->pcp
, high
, batch
);
4667 static void pageset_set_high_and_batch(struct zone
*zone
,
4668 struct per_cpu_pageset
*pcp
)
4670 if (percpu_pagelist_fraction
)
4671 pageset_set_high(pcp
,
4672 (zone
->managed_pages
/
4673 percpu_pagelist_fraction
));
4675 pageset_set_batch(pcp
, zone_batchsize(zone
));
4678 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
4680 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
4683 pageset_set_high_and_batch(zone
, pcp
);
4686 static void __meminit
setup_zone_pageset(struct zone
*zone
)
4689 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
4690 for_each_possible_cpu(cpu
)
4691 zone_pageset_init(zone
, cpu
);
4695 * Allocate per cpu pagesets and initialize them.
4696 * Before this call only boot pagesets were available.
4698 void __init
setup_per_cpu_pageset(void)
4702 for_each_populated_zone(zone
)
4703 setup_zone_pageset(zone
);
4706 static noinline __init_refok
4707 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
4713 * The per-page waitqueue mechanism uses hashed waitqueues
4716 zone
->wait_table_hash_nr_entries
=
4717 wait_table_hash_nr_entries(zone_size_pages
);
4718 zone
->wait_table_bits
=
4719 wait_table_bits(zone
->wait_table_hash_nr_entries
);
4720 alloc_size
= zone
->wait_table_hash_nr_entries
4721 * sizeof(wait_queue_head_t
);
4723 if (!slab_is_available()) {
4724 zone
->wait_table
= (wait_queue_head_t
*)
4725 memblock_virt_alloc_node_nopanic(
4726 alloc_size
, zone
->zone_pgdat
->node_id
);
4729 * This case means that a zone whose size was 0 gets new memory
4730 * via memory hot-add.
4731 * But it may be the case that a new node was hot-added. In
4732 * this case vmalloc() will not be able to use this new node's
4733 * memory - this wait_table must be initialized to use this new
4734 * node itself as well.
4735 * To use this new node's memory, further consideration will be
4738 zone
->wait_table
= vmalloc(alloc_size
);
4740 if (!zone
->wait_table
)
4743 for (i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
4744 init_waitqueue_head(zone
->wait_table
+ i
);
4749 static __meminit
void zone_pcp_init(struct zone
*zone
)
4752 * per cpu subsystem is not up at this point. The following code
4753 * relies on the ability of the linker to provide the
4754 * offset of a (static) per cpu variable into the per cpu area.
4756 zone
->pageset
= &boot_pageset
;
4758 if (populated_zone(zone
))
4759 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
4760 zone
->name
, zone
->present_pages
,
4761 zone_batchsize(zone
));
4764 int __meminit
init_currently_empty_zone(struct zone
*zone
,
4765 unsigned long zone_start_pfn
,
4768 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
4770 ret
= zone_wait_table_init(zone
, size
);
4773 pgdat
->nr_zones
= zone_idx(zone
) + 1;
4775 zone
->zone_start_pfn
= zone_start_pfn
;
4777 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
4778 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4780 (unsigned long)zone_idx(zone
),
4781 zone_start_pfn
, (zone_start_pfn
+ size
));
4783 zone_init_free_lists(zone
);
4788 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4789 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4792 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4794 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
4795 struct mminit_pfnnid_cache
*state
)
4797 unsigned long start_pfn
, end_pfn
;
4800 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
4801 return state
->last_nid
;
4803 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
4805 state
->last_start
= start_pfn
;
4806 state
->last_end
= end_pfn
;
4807 state
->last_nid
= nid
;
4812 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4815 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
4816 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4817 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
4819 * If an architecture guarantees that all ranges registered contain no holes
4820 * and may be freed, this this function may be used instead of calling
4821 * memblock_free_early_nid() manually.
4823 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
4825 unsigned long start_pfn
, end_pfn
;
4828 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
4829 start_pfn
= min(start_pfn
, max_low_pfn
);
4830 end_pfn
= min(end_pfn
, max_low_pfn
);
4832 if (start_pfn
< end_pfn
)
4833 memblock_free_early_nid(PFN_PHYS(start_pfn
),
4834 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
4840 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4841 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4843 * If an architecture guarantees that all ranges registered contain no holes and may
4844 * be freed, this function may be used instead of calling memory_present() manually.
4846 void __init
sparse_memory_present_with_active_regions(int nid
)
4848 unsigned long start_pfn
, end_pfn
;
4851 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
4852 memory_present(this_nid
, start_pfn
, end_pfn
);
4856 * get_pfn_range_for_nid - Return the start and end page frames for a node
4857 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4858 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
4859 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
4861 * It returns the start and end page frame of a node based on information
4862 * provided by memblock_set_node(). If called for a node
4863 * with no available memory, a warning is printed and the start and end
4866 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
4867 unsigned long *start_pfn
, unsigned long *end_pfn
)
4869 unsigned long this_start_pfn
, this_end_pfn
;
4875 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
4876 *start_pfn
= min(*start_pfn
, this_start_pfn
);
4877 *end_pfn
= max(*end_pfn
, this_end_pfn
);
4880 if (*start_pfn
== -1UL)
4885 * This finds a zone that can be used for ZONE_MOVABLE pages. The
4886 * assumption is made that zones within a node are ordered in monotonic
4887 * increasing memory addresses so that the "highest" populated zone is used
4889 static void __init
find_usable_zone_for_movable(void)
4892 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
4893 if (zone_index
== ZONE_MOVABLE
)
4896 if (arch_zone_highest_possible_pfn
[zone_index
] >
4897 arch_zone_lowest_possible_pfn
[zone_index
])
4901 VM_BUG_ON(zone_index
== -1);
4902 movable_zone
= zone_index
;
4906 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4907 * because it is sized independent of architecture. Unlike the other zones,
4908 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4909 * in each node depending on the size of each node and how evenly kernelcore
4910 * is distributed. This helper function adjusts the zone ranges
4911 * provided by the architecture for a given node by using the end of the
4912 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4913 * zones within a node are in order of monotonic increases memory addresses
4915 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
4916 unsigned long zone_type
,
4917 unsigned long node_start_pfn
,
4918 unsigned long node_end_pfn
,
4919 unsigned long *zone_start_pfn
,
4920 unsigned long *zone_end_pfn
)
4922 /* Only adjust if ZONE_MOVABLE is on this node */
4923 if (zone_movable_pfn
[nid
]) {
4924 /* Size ZONE_MOVABLE */
4925 if (zone_type
== ZONE_MOVABLE
) {
4926 *zone_start_pfn
= zone_movable_pfn
[nid
];
4927 *zone_end_pfn
= min(node_end_pfn
,
4928 arch_zone_highest_possible_pfn
[movable_zone
]);
4930 /* Adjust for ZONE_MOVABLE starting within this range */
4931 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
4932 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
4933 *zone_end_pfn
= zone_movable_pfn
[nid
];
4935 /* Check if this whole range is within ZONE_MOVABLE */
4936 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
4937 *zone_start_pfn
= *zone_end_pfn
;
4942 * Return the number of pages a zone spans in a node, including holes
4943 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4945 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4946 unsigned long zone_type
,
4947 unsigned long node_start_pfn
,
4948 unsigned long node_end_pfn
,
4949 unsigned long *ignored
)
4951 unsigned long zone_start_pfn
, zone_end_pfn
;
4953 /* When hotadd a new node from cpu_up(), the node should be empty */
4954 if (!node_start_pfn
&& !node_end_pfn
)
4957 /* Get the start and end of the zone */
4958 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
4959 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
4960 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4961 node_start_pfn
, node_end_pfn
,
4962 &zone_start_pfn
, &zone_end_pfn
);
4964 /* Check that this node has pages within the zone's required range */
4965 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
4968 /* Move the zone boundaries inside the node if necessary */
4969 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
4970 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
4972 /* Return the spanned pages */
4973 return zone_end_pfn
- zone_start_pfn
;
4977 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4978 * then all holes in the requested range will be accounted for.
4980 unsigned long __meminit
__absent_pages_in_range(int nid
,
4981 unsigned long range_start_pfn
,
4982 unsigned long range_end_pfn
)
4984 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
4985 unsigned long start_pfn
, end_pfn
;
4988 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
4989 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
4990 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
4991 nr_absent
-= end_pfn
- start_pfn
;
4997 * absent_pages_in_range - Return number of page frames in holes within a range
4998 * @start_pfn: The start PFN to start searching for holes
4999 * @end_pfn: The end PFN to stop searching for holes
5001 * It returns the number of pages frames in memory holes within a range.
5003 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
5004 unsigned long end_pfn
)
5006 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
5009 /* Return the number of page frames in holes in a zone on a node */
5010 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5011 unsigned long zone_type
,
5012 unsigned long node_start_pfn
,
5013 unsigned long node_end_pfn
,
5014 unsigned long *ignored
)
5016 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
5017 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
5018 unsigned long zone_start_pfn
, zone_end_pfn
;
5020 /* When hotadd a new node from cpu_up(), the node should be empty */
5021 if (!node_start_pfn
&& !node_end_pfn
)
5024 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
5025 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
5027 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5028 node_start_pfn
, node_end_pfn
,
5029 &zone_start_pfn
, &zone_end_pfn
);
5030 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
5033 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5034 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5035 unsigned long zone_type
,
5036 unsigned long node_start_pfn
,
5037 unsigned long node_end_pfn
,
5038 unsigned long *zones_size
)
5040 return zones_size
[zone_type
];
5043 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5044 unsigned long zone_type
,
5045 unsigned long node_start_pfn
,
5046 unsigned long node_end_pfn
,
5047 unsigned long *zholes_size
)
5052 return zholes_size
[zone_type
];
5055 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5057 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
5058 unsigned long node_start_pfn
,
5059 unsigned long node_end_pfn
,
5060 unsigned long *zones_size
,
5061 unsigned long *zholes_size
)
5063 unsigned long realtotalpages
= 0, totalpages
= 0;
5066 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5067 struct zone
*zone
= pgdat
->node_zones
+ i
;
5068 unsigned long size
, real_size
;
5070 size
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
5074 real_size
= size
- zone_absent_pages_in_node(pgdat
->node_id
, i
,
5075 node_start_pfn
, node_end_pfn
,
5077 zone
->spanned_pages
= size
;
5078 zone
->present_pages
= real_size
;
5081 realtotalpages
+= real_size
;
5084 pgdat
->node_spanned_pages
= totalpages
;
5085 pgdat
->node_present_pages
= realtotalpages
;
5086 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
5090 #ifndef CONFIG_SPARSEMEM
5092 * Calculate the size of the zone->blockflags rounded to an unsigned long
5093 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5094 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5095 * round what is now in bits to nearest long in bits, then return it in
5098 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
5100 unsigned long usemapsize
;
5102 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
5103 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
5104 usemapsize
= usemapsize
>> pageblock_order
;
5105 usemapsize
*= NR_PAGEBLOCK_BITS
;
5106 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
5108 return usemapsize
/ 8;
5111 static void __init
setup_usemap(struct pglist_data
*pgdat
,
5113 unsigned long zone_start_pfn
,
5114 unsigned long zonesize
)
5116 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
5117 zone
->pageblock_flags
= NULL
;
5119 zone
->pageblock_flags
=
5120 memblock_virt_alloc_node_nopanic(usemapsize
,
5124 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
5125 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
5126 #endif /* CONFIG_SPARSEMEM */
5128 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5130 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5131 void __paginginit
set_pageblock_order(void)
5135 /* Check that pageblock_nr_pages has not already been setup */
5136 if (pageblock_order
)
5139 if (HPAGE_SHIFT
> PAGE_SHIFT
)
5140 order
= HUGETLB_PAGE_ORDER
;
5142 order
= MAX_ORDER
- 1;
5145 * Assume the largest contiguous order of interest is a huge page.
5146 * This value may be variable depending on boot parameters on IA64 and
5149 pageblock_order
= order
;
5151 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5154 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5155 * is unused as pageblock_order is set at compile-time. See
5156 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5159 void __paginginit
set_pageblock_order(void)
5163 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5165 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
5166 unsigned long present_pages
)
5168 unsigned long pages
= spanned_pages
;
5171 * Provide a more accurate estimation if there are holes within
5172 * the zone and SPARSEMEM is in use. If there are holes within the
5173 * zone, each populated memory region may cost us one or two extra
5174 * memmap pages due to alignment because memmap pages for each
5175 * populated regions may not naturally algined on page boundary.
5176 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5178 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
5179 IS_ENABLED(CONFIG_SPARSEMEM
))
5180 pages
= present_pages
;
5182 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
5186 * Set up the zone data structures:
5187 * - mark all pages reserved
5188 * - mark all memory queues empty
5189 * - clear the memory bitmaps
5191 * NOTE: pgdat should get zeroed by caller.
5193 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
)
5196 int nid
= pgdat
->node_id
;
5197 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
5200 pgdat_resize_init(pgdat
);
5201 #ifdef CONFIG_NUMA_BALANCING
5202 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
5203 pgdat
->numabalancing_migrate_nr_pages
= 0;
5204 pgdat
->numabalancing_migrate_next_window
= jiffies
;
5206 init_waitqueue_head(&pgdat
->kswapd_wait
);
5207 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
5208 pgdat_page_ext_init(pgdat
);
5210 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5211 struct zone
*zone
= pgdat
->node_zones
+ j
;
5212 unsigned long size
, realsize
, freesize
, memmap_pages
;
5214 size
= zone
->spanned_pages
;
5215 realsize
= freesize
= zone
->present_pages
;
5218 * Adjust freesize so that it accounts for how much memory
5219 * is used by this zone for memmap. This affects the watermark
5220 * and per-cpu initialisations
5222 memmap_pages
= calc_memmap_size(size
, realsize
);
5223 if (!is_highmem_idx(j
)) {
5224 if (freesize
>= memmap_pages
) {
5225 freesize
-= memmap_pages
;
5228 " %s zone: %lu pages used for memmap\n",
5229 zone_names
[j
], memmap_pages
);
5232 " %s zone: %lu pages exceeds freesize %lu\n",
5233 zone_names
[j
], memmap_pages
, freesize
);
5236 /* Account for reserved pages */
5237 if (j
== 0 && freesize
> dma_reserve
) {
5238 freesize
-= dma_reserve
;
5239 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
5240 zone_names
[0], dma_reserve
);
5243 if (!is_highmem_idx(j
))
5244 nr_kernel_pages
+= freesize
;
5245 /* Charge for highmem memmap if there are enough kernel pages */
5246 else if (nr_kernel_pages
> memmap_pages
* 2)
5247 nr_kernel_pages
-= memmap_pages
;
5248 nr_all_pages
+= freesize
;
5251 * Set an approximate value for lowmem here, it will be adjusted
5252 * when the bootmem allocator frees pages into the buddy system.
5253 * And all highmem pages will be managed by the buddy system.
5255 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
5258 zone
->min_unmapped_pages
= (freesize
*sysctl_min_unmapped_ratio
)
5260 zone
->min_slab_pages
= (freesize
* sysctl_min_slab_ratio
) / 100;
5262 zone
->name
= zone_names
[j
];
5263 spin_lock_init(&zone
->lock
);
5264 spin_lock_init(&zone
->lru_lock
);
5265 zone_seqlock_init(zone
);
5266 zone
->zone_pgdat
= pgdat
;
5267 zone_pcp_init(zone
);
5269 /* For bootup, initialized properly in watermark setup */
5270 mod_zone_page_state(zone
, NR_ALLOC_BATCH
, zone
->managed_pages
);
5272 lruvec_init(&zone
->lruvec
);
5276 set_pageblock_order();
5277 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
5278 ret
= init_currently_empty_zone(zone
, zone_start_pfn
, size
);
5280 memmap_init(size
, nid
, j
, zone_start_pfn
);
5281 zone_start_pfn
+= size
;
5285 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
5287 unsigned long __maybe_unused start
= 0;
5288 unsigned long __maybe_unused offset
= 0;
5290 /* Skip empty nodes */
5291 if (!pgdat
->node_spanned_pages
)
5294 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5295 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
5296 offset
= pgdat
->node_start_pfn
- start
;
5297 /* ia64 gets its own node_mem_map, before this, without bootmem */
5298 if (!pgdat
->node_mem_map
) {
5299 unsigned long size
, end
;
5303 * The zone's endpoints aren't required to be MAX_ORDER
5304 * aligned but the node_mem_map endpoints must be in order
5305 * for the buddy allocator to function correctly.
5307 end
= pgdat_end_pfn(pgdat
);
5308 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
5309 size
= (end
- start
) * sizeof(struct page
);
5310 map
= alloc_remap(pgdat
->node_id
, size
);
5312 map
= memblock_virt_alloc_node_nopanic(size
,
5314 pgdat
->node_mem_map
= map
+ offset
;
5316 #ifndef CONFIG_NEED_MULTIPLE_NODES
5318 * With no DISCONTIG, the global mem_map is just set as node 0's
5320 if (pgdat
== NODE_DATA(0)) {
5321 mem_map
= NODE_DATA(0)->node_mem_map
;
5322 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
5323 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
5325 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5328 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
5331 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
5332 unsigned long node_start_pfn
, unsigned long *zholes_size
)
5334 pg_data_t
*pgdat
= NODE_DATA(nid
);
5335 unsigned long start_pfn
= 0;
5336 unsigned long end_pfn
= 0;
5338 /* pg_data_t should be reset to zero when it's allocated */
5339 WARN_ON(pgdat
->nr_zones
|| pgdat
->classzone_idx
);
5341 reset_deferred_meminit(pgdat
);
5342 pgdat
->node_id
= nid
;
5343 pgdat
->node_start_pfn
= node_start_pfn
;
5344 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5345 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
5346 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
5347 (u64
)start_pfn
<< PAGE_SHIFT
,
5348 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
5350 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
5351 zones_size
, zholes_size
);
5353 alloc_node_mem_map(pgdat
);
5354 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5355 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
5356 nid
, (unsigned long)pgdat
,
5357 (unsigned long)pgdat
->node_mem_map
);
5360 free_area_init_core(pgdat
);
5363 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5365 #if MAX_NUMNODES > 1
5367 * Figure out the number of possible node ids.
5369 void __init
setup_nr_node_ids(void)
5371 unsigned int highest
;
5373 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
5374 nr_node_ids
= highest
+ 1;
5379 * node_map_pfn_alignment - determine the maximum internode alignment
5381 * This function should be called after node map is populated and sorted.
5382 * It calculates the maximum power of two alignment which can distinguish
5385 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5386 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5387 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5388 * shifted, 1GiB is enough and this function will indicate so.
5390 * This is used to test whether pfn -> nid mapping of the chosen memory
5391 * model has fine enough granularity to avoid incorrect mapping for the
5392 * populated node map.
5394 * Returns the determined alignment in pfn's. 0 if there is no alignment
5395 * requirement (single node).
5397 unsigned long __init
node_map_pfn_alignment(void)
5399 unsigned long accl_mask
= 0, last_end
= 0;
5400 unsigned long start
, end
, mask
;
5404 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
5405 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
5412 * Start with a mask granular enough to pin-point to the
5413 * start pfn and tick off bits one-by-one until it becomes
5414 * too coarse to separate the current node from the last.
5416 mask
= ~((1 << __ffs(start
)) - 1);
5417 while (mask
&& last_end
<= (start
& (mask
<< 1)))
5420 /* accumulate all internode masks */
5424 /* convert mask to number of pages */
5425 return ~accl_mask
+ 1;
5428 /* Find the lowest pfn for a node */
5429 static unsigned long __init
find_min_pfn_for_node(int nid
)
5431 unsigned long min_pfn
= ULONG_MAX
;
5432 unsigned long start_pfn
;
5435 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
5436 min_pfn
= min(min_pfn
, start_pfn
);
5438 if (min_pfn
== ULONG_MAX
) {
5440 "Could not find start_pfn for node %d\n", nid
);
5448 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5450 * It returns the minimum PFN based on information provided via
5451 * memblock_set_node().
5453 unsigned long __init
find_min_pfn_with_active_regions(void)
5455 return find_min_pfn_for_node(MAX_NUMNODES
);
5459 * early_calculate_totalpages()
5460 * Sum pages in active regions for movable zone.
5461 * Populate N_MEMORY for calculating usable_nodes.
5463 static unsigned long __init
early_calculate_totalpages(void)
5465 unsigned long totalpages
= 0;
5466 unsigned long start_pfn
, end_pfn
;
5469 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
5470 unsigned long pages
= end_pfn
- start_pfn
;
5472 totalpages
+= pages
;
5474 node_set_state(nid
, N_MEMORY
);
5480 * Find the PFN the Movable zone begins in each node. Kernel memory
5481 * is spread evenly between nodes as long as the nodes have enough
5482 * memory. When they don't, some nodes will have more kernelcore than
5485 static void __init
find_zone_movable_pfns_for_nodes(void)
5488 unsigned long usable_startpfn
;
5489 unsigned long kernelcore_node
, kernelcore_remaining
;
5490 /* save the state before borrow the nodemask */
5491 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
5492 unsigned long totalpages
= early_calculate_totalpages();
5493 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
5494 struct memblock_region
*r
;
5496 /* Need to find movable_zone earlier when movable_node is specified. */
5497 find_usable_zone_for_movable();
5500 * If movable_node is specified, ignore kernelcore and movablecore
5503 if (movable_node_is_enabled()) {
5504 for_each_memblock(memory
, r
) {
5505 if (!memblock_is_hotpluggable(r
))
5510 usable_startpfn
= PFN_DOWN(r
->base
);
5511 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
5512 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
5520 * If movablecore=nn[KMG] was specified, calculate what size of
5521 * kernelcore that corresponds so that memory usable for
5522 * any allocation type is evenly spread. If both kernelcore
5523 * and movablecore are specified, then the value of kernelcore
5524 * will be used for required_kernelcore if it's greater than
5525 * what movablecore would have allowed.
5527 if (required_movablecore
) {
5528 unsigned long corepages
;
5531 * Round-up so that ZONE_MOVABLE is at least as large as what
5532 * was requested by the user
5534 required_movablecore
=
5535 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
5536 required_movablecore
= min(totalpages
, required_movablecore
);
5537 corepages
= totalpages
- required_movablecore
;
5539 required_kernelcore
= max(required_kernelcore
, corepages
);
5543 * If kernelcore was not specified or kernelcore size is larger
5544 * than totalpages, there is no ZONE_MOVABLE.
5546 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
5549 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5550 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
5553 /* Spread kernelcore memory as evenly as possible throughout nodes */
5554 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5555 for_each_node_state(nid
, N_MEMORY
) {
5556 unsigned long start_pfn
, end_pfn
;
5559 * Recalculate kernelcore_node if the division per node
5560 * now exceeds what is necessary to satisfy the requested
5561 * amount of memory for the kernel
5563 if (required_kernelcore
< kernelcore_node
)
5564 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5567 * As the map is walked, we track how much memory is usable
5568 * by the kernel using kernelcore_remaining. When it is
5569 * 0, the rest of the node is usable by ZONE_MOVABLE
5571 kernelcore_remaining
= kernelcore_node
;
5573 /* Go through each range of PFNs within this node */
5574 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5575 unsigned long size_pages
;
5577 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
5578 if (start_pfn
>= end_pfn
)
5581 /* Account for what is only usable for kernelcore */
5582 if (start_pfn
< usable_startpfn
) {
5583 unsigned long kernel_pages
;
5584 kernel_pages
= min(end_pfn
, usable_startpfn
)
5587 kernelcore_remaining
-= min(kernel_pages
,
5588 kernelcore_remaining
);
5589 required_kernelcore
-= min(kernel_pages
,
5590 required_kernelcore
);
5592 /* Continue if range is now fully accounted */
5593 if (end_pfn
<= usable_startpfn
) {
5596 * Push zone_movable_pfn to the end so
5597 * that if we have to rebalance
5598 * kernelcore across nodes, we will
5599 * not double account here
5601 zone_movable_pfn
[nid
] = end_pfn
;
5604 start_pfn
= usable_startpfn
;
5608 * The usable PFN range for ZONE_MOVABLE is from
5609 * start_pfn->end_pfn. Calculate size_pages as the
5610 * number of pages used as kernelcore
5612 size_pages
= end_pfn
- start_pfn
;
5613 if (size_pages
> kernelcore_remaining
)
5614 size_pages
= kernelcore_remaining
;
5615 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
5618 * Some kernelcore has been met, update counts and
5619 * break if the kernelcore for this node has been
5622 required_kernelcore
-= min(required_kernelcore
,
5624 kernelcore_remaining
-= size_pages
;
5625 if (!kernelcore_remaining
)
5631 * If there is still required_kernelcore, we do another pass with one
5632 * less node in the count. This will push zone_movable_pfn[nid] further
5633 * along on the nodes that still have memory until kernelcore is
5637 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
5641 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5642 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
5643 zone_movable_pfn
[nid
] =
5644 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
5647 /* restore the node_state */
5648 node_states
[N_MEMORY
] = saved_node_state
;
5651 /* Any regular or high memory on that node ? */
5652 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
5654 enum zone_type zone_type
;
5656 if (N_MEMORY
== N_NORMAL_MEMORY
)
5659 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
5660 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
5661 if (populated_zone(zone
)) {
5662 node_set_state(nid
, N_HIGH_MEMORY
);
5663 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
5664 zone_type
<= ZONE_NORMAL
)
5665 node_set_state(nid
, N_NORMAL_MEMORY
);
5672 * free_area_init_nodes - Initialise all pg_data_t and zone data
5673 * @max_zone_pfn: an array of max PFNs for each zone
5675 * This will call free_area_init_node() for each active node in the system.
5676 * Using the page ranges provided by memblock_set_node(), the size of each
5677 * zone in each node and their holes is calculated. If the maximum PFN
5678 * between two adjacent zones match, it is assumed that the zone is empty.
5679 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5680 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5681 * starts where the previous one ended. For example, ZONE_DMA32 starts
5682 * at arch_max_dma_pfn.
5684 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
5686 unsigned long start_pfn
, end_pfn
;
5689 /* Record where the zone boundaries are */
5690 memset(arch_zone_lowest_possible_pfn
, 0,
5691 sizeof(arch_zone_lowest_possible_pfn
));
5692 memset(arch_zone_highest_possible_pfn
, 0,
5693 sizeof(arch_zone_highest_possible_pfn
));
5694 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
5695 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
5696 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
5697 if (i
== ZONE_MOVABLE
)
5699 arch_zone_lowest_possible_pfn
[i
] =
5700 arch_zone_highest_possible_pfn
[i
-1];
5701 arch_zone_highest_possible_pfn
[i
] =
5702 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
5704 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
5705 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
5707 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
5708 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
5709 find_zone_movable_pfns_for_nodes();
5711 /* Print out the zone ranges */
5712 pr_info("Zone ranges:\n");
5713 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5714 if (i
== ZONE_MOVABLE
)
5716 pr_info(" %-8s ", zone_names
[i
]);
5717 if (arch_zone_lowest_possible_pfn
[i
] ==
5718 arch_zone_highest_possible_pfn
[i
])
5721 pr_cont("[mem %#018Lx-%#018Lx]\n",
5722 (u64
)arch_zone_lowest_possible_pfn
[i
]
5724 ((u64
)arch_zone_highest_possible_pfn
[i
]
5725 << PAGE_SHIFT
) - 1);
5728 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5729 pr_info("Movable zone start for each node\n");
5730 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
5731 if (zone_movable_pfn
[i
])
5732 pr_info(" Node %d: %#018Lx\n", i
,
5733 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
5736 /* Print out the early node map */
5737 pr_info("Early memory node ranges\n");
5738 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
5739 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
5740 (u64
)start_pfn
<< PAGE_SHIFT
,
5741 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
5743 /* Initialise every node */
5744 mminit_verify_pageflags_layout();
5745 setup_nr_node_ids();
5746 for_each_online_node(nid
) {
5747 pg_data_t
*pgdat
= NODE_DATA(nid
);
5748 free_area_init_node(nid
, NULL
,
5749 find_min_pfn_for_node(nid
), NULL
);
5751 /* Any memory on that node */
5752 if (pgdat
->node_present_pages
)
5753 node_set_state(nid
, N_MEMORY
);
5754 check_for_memory(pgdat
, nid
);
5758 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
5760 unsigned long long coremem
;
5764 coremem
= memparse(p
, &p
);
5765 *core
= coremem
>> PAGE_SHIFT
;
5767 /* Paranoid check that UL is enough for the coremem value */
5768 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
5774 * kernelcore=size sets the amount of memory for use for allocations that
5775 * cannot be reclaimed or migrated.
5777 static int __init
cmdline_parse_kernelcore(char *p
)
5779 return cmdline_parse_core(p
, &required_kernelcore
);
5783 * movablecore=size sets the amount of memory for use for allocations that
5784 * can be reclaimed or migrated.
5786 static int __init
cmdline_parse_movablecore(char *p
)
5788 return cmdline_parse_core(p
, &required_movablecore
);
5791 early_param("kernelcore", cmdline_parse_kernelcore
);
5792 early_param("movablecore", cmdline_parse_movablecore
);
5794 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5796 void adjust_managed_page_count(struct page
*page
, long count
)
5798 spin_lock(&managed_page_count_lock
);
5799 page_zone(page
)->managed_pages
+= count
;
5800 totalram_pages
+= count
;
5801 #ifdef CONFIG_HIGHMEM
5802 if (PageHighMem(page
))
5803 totalhigh_pages
+= count
;
5805 spin_unlock(&managed_page_count_lock
);
5807 EXPORT_SYMBOL(adjust_managed_page_count
);
5809 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
5812 unsigned long pages
= 0;
5814 start
= (void *)PAGE_ALIGN((unsigned long)start
);
5815 end
= (void *)((unsigned long)end
& PAGE_MASK
);
5816 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
5817 if ((unsigned int)poison
<= 0xFF)
5818 memset(pos
, poison
, PAGE_SIZE
);
5819 free_reserved_page(virt_to_page(pos
));
5823 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
5824 s
, pages
<< (PAGE_SHIFT
- 10), start
, end
);
5828 EXPORT_SYMBOL(free_reserved_area
);
5830 #ifdef CONFIG_HIGHMEM
5831 void free_highmem_page(struct page
*page
)
5833 __free_reserved_page(page
);
5835 page_zone(page
)->managed_pages
++;
5841 void __init
mem_init_print_info(const char *str
)
5843 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
5844 unsigned long init_code_size
, init_data_size
;
5846 physpages
= get_num_physpages();
5847 codesize
= _etext
- _stext
;
5848 datasize
= _edata
- _sdata
;
5849 rosize
= __end_rodata
- __start_rodata
;
5850 bss_size
= __bss_stop
- __bss_start
;
5851 init_data_size
= __init_end
- __init_begin
;
5852 init_code_size
= _einittext
- _sinittext
;
5855 * Detect special cases and adjust section sizes accordingly:
5856 * 1) .init.* may be embedded into .data sections
5857 * 2) .init.text.* may be out of [__init_begin, __init_end],
5858 * please refer to arch/tile/kernel/vmlinux.lds.S.
5859 * 3) .rodata.* may be embedded into .text or .data sections.
5861 #define adj_init_size(start, end, size, pos, adj) \
5863 if (start <= pos && pos < end && size > adj) \
5867 adj_init_size(__init_begin
, __init_end
, init_data_size
,
5868 _sinittext
, init_code_size
);
5869 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
5870 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
5871 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
5872 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
5874 #undef adj_init_size
5876 pr_info("Memory: %luK/%luK available "
5877 "(%luK kernel code, %luK rwdata, %luK rodata, "
5878 "%luK init, %luK bss, %luK reserved, %luK cma-reserved"
5879 #ifdef CONFIG_HIGHMEM
5883 nr_free_pages() << (PAGE_SHIFT
-10), physpages
<< (PAGE_SHIFT
-10),
5884 codesize
>> 10, datasize
>> 10, rosize
>> 10,
5885 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
5886 (physpages
- totalram_pages
- totalcma_pages
) << (PAGE_SHIFT
-10),
5887 totalcma_pages
<< (PAGE_SHIFT
-10),
5888 #ifdef CONFIG_HIGHMEM
5889 totalhigh_pages
<< (PAGE_SHIFT
-10),
5891 str
? ", " : "", str
? str
: "");
5895 * set_dma_reserve - set the specified number of pages reserved in the first zone
5896 * @new_dma_reserve: The number of pages to mark reserved
5898 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
5899 * In the DMA zone, a significant percentage may be consumed by kernel image
5900 * and other unfreeable allocations which can skew the watermarks badly. This
5901 * function may optionally be used to account for unfreeable pages in the
5902 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
5903 * smaller per-cpu batchsize.
5905 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
5907 dma_reserve
= new_dma_reserve
;
5910 void __init
free_area_init(unsigned long *zones_size
)
5912 free_area_init_node(0, zones_size
,
5913 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
5916 static int page_alloc_cpu_notify(struct notifier_block
*self
,
5917 unsigned long action
, void *hcpu
)
5919 int cpu
= (unsigned long)hcpu
;
5921 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
5922 lru_add_drain_cpu(cpu
);
5926 * Spill the event counters of the dead processor
5927 * into the current processors event counters.
5928 * This artificially elevates the count of the current
5931 vm_events_fold_cpu(cpu
);
5934 * Zero the differential counters of the dead processor
5935 * so that the vm statistics are consistent.
5937 * This is only okay since the processor is dead and cannot
5938 * race with what we are doing.
5940 cpu_vm_stats_fold(cpu
);
5945 void __init
page_alloc_init(void)
5947 hotcpu_notifier(page_alloc_cpu_notify
, 0);
5951 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
5952 * or min_free_kbytes changes.
5954 static void calculate_totalreserve_pages(void)
5956 struct pglist_data
*pgdat
;
5957 unsigned long reserve_pages
= 0;
5958 enum zone_type i
, j
;
5960 for_each_online_pgdat(pgdat
) {
5961 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5962 struct zone
*zone
= pgdat
->node_zones
+ i
;
5965 /* Find valid and maximum lowmem_reserve in the zone */
5966 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
5967 if (zone
->lowmem_reserve
[j
] > max
)
5968 max
= zone
->lowmem_reserve
[j
];
5971 /* we treat the high watermark as reserved pages. */
5972 max
+= high_wmark_pages(zone
);
5974 if (max
> zone
->managed_pages
)
5975 max
= zone
->managed_pages
;
5977 zone
->totalreserve_pages
= max
;
5979 reserve_pages
+= max
;
5982 totalreserve_pages
= reserve_pages
;
5986 * setup_per_zone_lowmem_reserve - called whenever
5987 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
5988 * has a correct pages reserved value, so an adequate number of
5989 * pages are left in the zone after a successful __alloc_pages().
5991 static void setup_per_zone_lowmem_reserve(void)
5993 struct pglist_data
*pgdat
;
5994 enum zone_type j
, idx
;
5996 for_each_online_pgdat(pgdat
) {
5997 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5998 struct zone
*zone
= pgdat
->node_zones
+ j
;
5999 unsigned long managed_pages
= zone
->managed_pages
;
6001 zone
->lowmem_reserve
[j
] = 0;
6005 struct zone
*lower_zone
;
6009 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
6010 sysctl_lowmem_reserve_ratio
[idx
] = 1;
6012 lower_zone
= pgdat
->node_zones
+ idx
;
6013 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
6014 sysctl_lowmem_reserve_ratio
[idx
];
6015 managed_pages
+= lower_zone
->managed_pages
;
6020 /* update totalreserve_pages */
6021 calculate_totalreserve_pages();
6024 static void __setup_per_zone_wmarks(void)
6026 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
6027 unsigned long lowmem_pages
= 0;
6029 unsigned long flags
;
6031 /* Calculate total number of !ZONE_HIGHMEM pages */
6032 for_each_zone(zone
) {
6033 if (!is_highmem(zone
))
6034 lowmem_pages
+= zone
->managed_pages
;
6037 for_each_zone(zone
) {
6040 spin_lock_irqsave(&zone
->lock
, flags
);
6041 tmp
= (u64
)pages_min
* zone
->managed_pages
;
6042 do_div(tmp
, lowmem_pages
);
6043 if (is_highmem(zone
)) {
6045 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6046 * need highmem pages, so cap pages_min to a small
6049 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6050 * deltas control asynch page reclaim, and so should
6051 * not be capped for highmem.
6053 unsigned long min_pages
;
6055 min_pages
= zone
->managed_pages
/ 1024;
6056 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
6057 zone
->watermark
[WMARK_MIN
] = min_pages
;
6060 * If it's a lowmem zone, reserve a number of pages
6061 * proportionate to the zone's size.
6063 zone
->watermark
[WMARK_MIN
] = tmp
;
6066 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + (tmp
>> 2);
6067 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + (tmp
>> 1);
6069 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
6070 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
6071 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
6073 spin_unlock_irqrestore(&zone
->lock
, flags
);
6076 /* update totalreserve_pages */
6077 calculate_totalreserve_pages();
6081 * setup_per_zone_wmarks - called when min_free_kbytes changes
6082 * or when memory is hot-{added|removed}
6084 * Ensures that the watermark[min,low,high] values for each zone are set
6085 * correctly with respect to min_free_kbytes.
6087 void setup_per_zone_wmarks(void)
6089 mutex_lock(&zonelists_mutex
);
6090 __setup_per_zone_wmarks();
6091 mutex_unlock(&zonelists_mutex
);
6095 * The inactive anon list should be small enough that the VM never has to
6096 * do too much work, but large enough that each inactive page has a chance
6097 * to be referenced again before it is swapped out.
6099 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
6100 * INACTIVE_ANON pages on this zone's LRU, maintained by the
6101 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
6102 * the anonymous pages are kept on the inactive list.
6105 * memory ratio inactive anon
6106 * -------------------------------------
6115 static void __meminit
calculate_zone_inactive_ratio(struct zone
*zone
)
6117 unsigned int gb
, ratio
;
6119 /* Zone size in gigabytes */
6120 gb
= zone
->managed_pages
>> (30 - PAGE_SHIFT
);
6122 ratio
= int_sqrt(10 * gb
);
6126 zone
->inactive_ratio
= ratio
;
6129 static void __meminit
setup_per_zone_inactive_ratio(void)
6134 calculate_zone_inactive_ratio(zone
);
6138 * Initialise min_free_kbytes.
6140 * For small machines we want it small (128k min). For large machines
6141 * we want it large (64MB max). But it is not linear, because network
6142 * bandwidth does not increase linearly with machine size. We use
6144 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6145 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6161 int __meminit
init_per_zone_wmark_min(void)
6163 unsigned long lowmem_kbytes
;
6164 int new_min_free_kbytes
;
6166 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
6167 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
6169 if (new_min_free_kbytes
> user_min_free_kbytes
) {
6170 min_free_kbytes
= new_min_free_kbytes
;
6171 if (min_free_kbytes
< 128)
6172 min_free_kbytes
= 128;
6173 if (min_free_kbytes
> 65536)
6174 min_free_kbytes
= 65536;
6176 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6177 new_min_free_kbytes
, user_min_free_kbytes
);
6179 setup_per_zone_wmarks();
6180 refresh_zone_stat_thresholds();
6181 setup_per_zone_lowmem_reserve();
6182 setup_per_zone_inactive_ratio();
6185 module_init(init_per_zone_wmark_min
)
6188 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6189 * that we can call two helper functions whenever min_free_kbytes
6192 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
6193 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6197 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6202 user_min_free_kbytes
= min_free_kbytes
;
6203 setup_per_zone_wmarks();
6209 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6210 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6215 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6220 zone
->min_unmapped_pages
= (zone
->managed_pages
*
6221 sysctl_min_unmapped_ratio
) / 100;
6225 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6226 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6231 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6236 zone
->min_slab_pages
= (zone
->managed_pages
*
6237 sysctl_min_slab_ratio
) / 100;
6243 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6244 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6245 * whenever sysctl_lowmem_reserve_ratio changes.
6247 * The reserve ratio obviously has absolutely no relation with the
6248 * minimum watermarks. The lowmem reserve ratio can only make sense
6249 * if in function of the boot time zone sizes.
6251 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6252 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6254 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6255 setup_per_zone_lowmem_reserve();
6260 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6261 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6262 * pagelist can have before it gets flushed back to buddy allocator.
6264 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
6265 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6268 int old_percpu_pagelist_fraction
;
6271 mutex_lock(&pcp_batch_high_lock
);
6272 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
6274 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6275 if (!write
|| ret
< 0)
6278 /* Sanity checking to avoid pcp imbalance */
6279 if (percpu_pagelist_fraction
&&
6280 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
6281 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
6287 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
6290 for_each_populated_zone(zone
) {
6293 for_each_possible_cpu(cpu
)
6294 pageset_set_high_and_batch(zone
,
6295 per_cpu_ptr(zone
->pageset
, cpu
));
6298 mutex_unlock(&pcp_batch_high_lock
);
6303 int hashdist
= HASHDIST_DEFAULT
;
6305 static int __init
set_hashdist(char *str
)
6309 hashdist
= simple_strtoul(str
, &str
, 0);
6312 __setup("hashdist=", set_hashdist
);
6316 * allocate a large system hash table from bootmem
6317 * - it is assumed that the hash table must contain an exact power-of-2
6318 * quantity of entries
6319 * - limit is the number of hash buckets, not the total allocation size
6321 void *__init
alloc_large_system_hash(const char *tablename
,
6322 unsigned long bucketsize
,
6323 unsigned long numentries
,
6326 unsigned int *_hash_shift
,
6327 unsigned int *_hash_mask
,
6328 unsigned long low_limit
,
6329 unsigned long high_limit
)
6331 unsigned long long max
= high_limit
;
6332 unsigned long log2qty
, size
;
6335 /* allow the kernel cmdline to have a say */
6337 /* round applicable memory size up to nearest megabyte */
6338 numentries
= nr_kernel_pages
;
6340 /* It isn't necessary when PAGE_SIZE >= 1MB */
6341 if (PAGE_SHIFT
< 20)
6342 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
6344 /* limit to 1 bucket per 2^scale bytes of low memory */
6345 if (scale
> PAGE_SHIFT
)
6346 numentries
>>= (scale
- PAGE_SHIFT
);
6348 numentries
<<= (PAGE_SHIFT
- scale
);
6350 /* Make sure we've got at least a 0-order allocation.. */
6351 if (unlikely(flags
& HASH_SMALL
)) {
6352 /* Makes no sense without HASH_EARLY */
6353 WARN_ON(!(flags
& HASH_EARLY
));
6354 if (!(numentries
>> *_hash_shift
)) {
6355 numentries
= 1UL << *_hash_shift
;
6356 BUG_ON(!numentries
);
6358 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
6359 numentries
= PAGE_SIZE
/ bucketsize
;
6361 numentries
= roundup_pow_of_two(numentries
);
6363 /* limit allocation size to 1/16 total memory by default */
6365 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
6366 do_div(max
, bucketsize
);
6368 max
= min(max
, 0x80000000ULL
);
6370 if (numentries
< low_limit
)
6371 numentries
= low_limit
;
6372 if (numentries
> max
)
6375 log2qty
= ilog2(numentries
);
6378 size
= bucketsize
<< log2qty
;
6379 if (flags
& HASH_EARLY
)
6380 table
= memblock_virt_alloc_nopanic(size
, 0);
6382 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
6385 * If bucketsize is not a power-of-two, we may free
6386 * some pages at the end of hash table which
6387 * alloc_pages_exact() automatically does
6389 if (get_order(size
) < MAX_ORDER
) {
6390 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
6391 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
6394 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
6397 panic("Failed to allocate %s hash table\n", tablename
);
6399 printk(KERN_INFO
"%s hash table entries: %ld (order: %d, %lu bytes)\n",
6402 ilog2(size
) - PAGE_SHIFT
,
6406 *_hash_shift
= log2qty
;
6408 *_hash_mask
= (1 << log2qty
) - 1;
6413 /* Return a pointer to the bitmap storing bits affecting a block of pages */
6414 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
6417 #ifdef CONFIG_SPARSEMEM
6418 return __pfn_to_section(pfn
)->pageblock_flags
;
6420 return zone
->pageblock_flags
;
6421 #endif /* CONFIG_SPARSEMEM */
6424 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
6426 #ifdef CONFIG_SPARSEMEM
6427 pfn
&= (PAGES_PER_SECTION
-1);
6428 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6430 pfn
= pfn
- round_down(zone
->zone_start_pfn
, pageblock_nr_pages
);
6431 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6432 #endif /* CONFIG_SPARSEMEM */
6436 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
6437 * @page: The page within the block of interest
6438 * @pfn: The target page frame number
6439 * @end_bitidx: The last bit of interest to retrieve
6440 * @mask: mask of bits that the caller is interested in
6442 * Return: pageblock_bits flags
6444 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
6445 unsigned long end_bitidx
,
6449 unsigned long *bitmap
;
6450 unsigned long bitidx
, word_bitidx
;
6453 zone
= page_zone(page
);
6454 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6455 bitidx
= pfn_to_bitidx(zone
, pfn
);
6456 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6457 bitidx
&= (BITS_PER_LONG
-1);
6459 word
= bitmap
[word_bitidx
];
6460 bitidx
+= end_bitidx
;
6461 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
6465 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
6466 * @page: The page within the block of interest
6467 * @flags: The flags to set
6468 * @pfn: The target page frame number
6469 * @end_bitidx: The last bit of interest
6470 * @mask: mask of bits that the caller is interested in
6472 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
6474 unsigned long end_bitidx
,
6478 unsigned long *bitmap
;
6479 unsigned long bitidx
, word_bitidx
;
6480 unsigned long old_word
, word
;
6482 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
6484 zone
= page_zone(page
);
6485 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6486 bitidx
= pfn_to_bitidx(zone
, pfn
);
6487 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6488 bitidx
&= (BITS_PER_LONG
-1);
6490 VM_BUG_ON_PAGE(!zone_spans_pfn(zone
, pfn
), page
);
6492 bitidx
+= end_bitidx
;
6493 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
6494 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
6496 word
= READ_ONCE(bitmap
[word_bitidx
]);
6498 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
6499 if (word
== old_word
)
6506 * This function checks whether pageblock includes unmovable pages or not.
6507 * If @count is not zero, it is okay to include less @count unmovable pages
6509 * PageLRU check without isolation or lru_lock could race so that
6510 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6511 * expect this function should be exact.
6513 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
6514 bool skip_hwpoisoned_pages
)
6516 unsigned long pfn
, iter
, found
;
6520 * For avoiding noise data, lru_add_drain_all() should be called
6521 * If ZONE_MOVABLE, the zone never contains unmovable pages
6523 if (zone_idx(zone
) == ZONE_MOVABLE
)
6525 mt
= get_pageblock_migratetype(page
);
6526 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
6529 pfn
= page_to_pfn(page
);
6530 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
6531 unsigned long check
= pfn
+ iter
;
6533 if (!pfn_valid_within(check
))
6536 page
= pfn_to_page(check
);
6539 * Hugepages are not in LRU lists, but they're movable.
6540 * We need not scan over tail pages bacause we don't
6541 * handle each tail page individually in migration.
6543 if (PageHuge(page
)) {
6544 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
6549 * We can't use page_count without pin a page
6550 * because another CPU can free compound page.
6551 * This check already skips compound tails of THP
6552 * because their page->_count is zero at all time.
6554 if (!atomic_read(&page
->_count
)) {
6555 if (PageBuddy(page
))
6556 iter
+= (1 << page_order(page
)) - 1;
6561 * The HWPoisoned page may be not in buddy system, and
6562 * page_count() is not 0.
6564 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
6570 * If there are RECLAIMABLE pages, we need to check
6571 * it. But now, memory offline itself doesn't call
6572 * shrink_node_slabs() and it still to be fixed.
6575 * If the page is not RAM, page_count()should be 0.
6576 * we don't need more check. This is an _used_ not-movable page.
6578 * The problematic thing here is PG_reserved pages. PG_reserved
6579 * is set to both of a memory hole page and a _used_ kernel
6588 bool is_pageblock_removable_nolock(struct page
*page
)
6594 * We have to be careful here because we are iterating over memory
6595 * sections which are not zone aware so we might end up outside of
6596 * the zone but still within the section.
6597 * We have to take care about the node as well. If the node is offline
6598 * its NODE_DATA will be NULL - see page_zone.
6600 if (!node_online(page_to_nid(page
)))
6603 zone
= page_zone(page
);
6604 pfn
= page_to_pfn(page
);
6605 if (!zone_spans_pfn(zone
, pfn
))
6608 return !has_unmovable_pages(zone
, page
, 0, true);
6613 static unsigned long pfn_max_align_down(unsigned long pfn
)
6615 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6616 pageblock_nr_pages
) - 1);
6619 static unsigned long pfn_max_align_up(unsigned long pfn
)
6621 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6622 pageblock_nr_pages
));
6625 /* [start, end) must belong to a single zone. */
6626 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
6627 unsigned long start
, unsigned long end
)
6629 /* This function is based on compact_zone() from compaction.c. */
6630 unsigned long nr_reclaimed
;
6631 unsigned long pfn
= start
;
6632 unsigned int tries
= 0;
6637 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
6638 if (fatal_signal_pending(current
)) {
6643 if (list_empty(&cc
->migratepages
)) {
6644 cc
->nr_migratepages
= 0;
6645 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
6651 } else if (++tries
== 5) {
6652 ret
= ret
< 0 ? ret
: -EBUSY
;
6656 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
6658 cc
->nr_migratepages
-= nr_reclaimed
;
6660 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
6661 NULL
, 0, cc
->mode
, MR_CMA
);
6664 putback_movable_pages(&cc
->migratepages
);
6671 * alloc_contig_range() -- tries to allocate given range of pages
6672 * @start: start PFN to allocate
6673 * @end: one-past-the-last PFN to allocate
6674 * @migratetype: migratetype of the underlaying pageblocks (either
6675 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
6676 * in range must have the same migratetype and it must
6677 * be either of the two.
6679 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
6680 * aligned, however it's the caller's responsibility to guarantee that
6681 * we are the only thread that changes migrate type of pageblocks the
6684 * The PFN range must belong to a single zone.
6686 * Returns zero on success or negative error code. On success all
6687 * pages which PFN is in [start, end) are allocated for the caller and
6688 * need to be freed with free_contig_range().
6690 int alloc_contig_range(unsigned long start
, unsigned long end
,
6691 unsigned migratetype
)
6693 unsigned long outer_start
, outer_end
;
6697 struct compact_control cc
= {
6698 .nr_migratepages
= 0,
6700 .zone
= page_zone(pfn_to_page(start
)),
6701 .mode
= MIGRATE_SYNC
,
6702 .ignore_skip_hint
= true,
6704 INIT_LIST_HEAD(&cc
.migratepages
);
6707 * What we do here is we mark all pageblocks in range as
6708 * MIGRATE_ISOLATE. Because pageblock and max order pages may
6709 * have different sizes, and due to the way page allocator
6710 * work, we align the range to biggest of the two pages so
6711 * that page allocator won't try to merge buddies from
6712 * different pageblocks and change MIGRATE_ISOLATE to some
6713 * other migration type.
6715 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
6716 * migrate the pages from an unaligned range (ie. pages that
6717 * we are interested in). This will put all the pages in
6718 * range back to page allocator as MIGRATE_ISOLATE.
6720 * When this is done, we take the pages in range from page
6721 * allocator removing them from the buddy system. This way
6722 * page allocator will never consider using them.
6724 * This lets us mark the pageblocks back as
6725 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
6726 * aligned range but not in the unaligned, original range are
6727 * put back to page allocator so that buddy can use them.
6730 ret
= start_isolate_page_range(pfn_max_align_down(start
),
6731 pfn_max_align_up(end
), migratetype
,
6737 * In case of -EBUSY, we'd like to know which page causes problem.
6738 * So, just fall through. We will check it in test_pages_isolated().
6740 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
6741 if (ret
&& ret
!= -EBUSY
)
6745 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
6746 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
6747 * more, all pages in [start, end) are free in page allocator.
6748 * What we are going to do is to allocate all pages from
6749 * [start, end) (that is remove them from page allocator).
6751 * The only problem is that pages at the beginning and at the
6752 * end of interesting range may be not aligned with pages that
6753 * page allocator holds, ie. they can be part of higher order
6754 * pages. Because of this, we reserve the bigger range and
6755 * once this is done free the pages we are not interested in.
6757 * We don't have to hold zone->lock here because the pages are
6758 * isolated thus they won't get removed from buddy.
6761 lru_add_drain_all();
6762 drain_all_pages(cc
.zone
);
6765 outer_start
= start
;
6766 while (!PageBuddy(pfn_to_page(outer_start
))) {
6767 if (++order
>= MAX_ORDER
) {
6768 outer_start
= start
;
6771 outer_start
&= ~0UL << order
;
6774 if (outer_start
!= start
) {
6775 order
= page_order(pfn_to_page(outer_start
));
6778 * outer_start page could be small order buddy page and
6779 * it doesn't include start page. Adjust outer_start
6780 * in this case to report failed page properly
6781 * on tracepoint in test_pages_isolated()
6783 if (outer_start
+ (1UL << order
) <= start
)
6784 outer_start
= start
;
6787 /* Make sure the range is really isolated. */
6788 if (test_pages_isolated(outer_start
, end
, false)) {
6789 pr_info("%s: [%lx, %lx) PFNs busy\n",
6790 __func__
, outer_start
, end
);
6795 /* Grab isolated pages from freelists. */
6796 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
6802 /* Free head and tail (if any) */
6803 if (start
!= outer_start
)
6804 free_contig_range(outer_start
, start
- outer_start
);
6805 if (end
!= outer_end
)
6806 free_contig_range(end
, outer_end
- end
);
6809 undo_isolate_page_range(pfn_max_align_down(start
),
6810 pfn_max_align_up(end
), migratetype
);
6814 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
6816 unsigned int count
= 0;
6818 for (; nr_pages
--; pfn
++) {
6819 struct page
*page
= pfn_to_page(pfn
);
6821 count
+= page_count(page
) != 1;
6824 WARN(count
!= 0, "%d pages are still in use!\n", count
);
6828 #ifdef CONFIG_MEMORY_HOTPLUG
6830 * The zone indicated has a new number of managed_pages; batch sizes and percpu
6831 * page high values need to be recalulated.
6833 void __meminit
zone_pcp_update(struct zone
*zone
)
6836 mutex_lock(&pcp_batch_high_lock
);
6837 for_each_possible_cpu(cpu
)
6838 pageset_set_high_and_batch(zone
,
6839 per_cpu_ptr(zone
->pageset
, cpu
));
6840 mutex_unlock(&pcp_batch_high_lock
);
6844 void zone_pcp_reset(struct zone
*zone
)
6846 unsigned long flags
;
6848 struct per_cpu_pageset
*pset
;
6850 /* avoid races with drain_pages() */
6851 local_irq_save(flags
);
6852 if (zone
->pageset
!= &boot_pageset
) {
6853 for_each_online_cpu(cpu
) {
6854 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
6855 drain_zonestat(zone
, pset
);
6857 free_percpu(zone
->pageset
);
6858 zone
->pageset
= &boot_pageset
;
6860 local_irq_restore(flags
);
6863 #ifdef CONFIG_MEMORY_HOTREMOVE
6865 * All pages in the range must be isolated before calling this.
6868 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
6872 unsigned int order
, i
;
6874 unsigned long flags
;
6875 /* find the first valid pfn */
6876 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
6881 zone
= page_zone(pfn_to_page(pfn
));
6882 spin_lock_irqsave(&zone
->lock
, flags
);
6884 while (pfn
< end_pfn
) {
6885 if (!pfn_valid(pfn
)) {
6889 page
= pfn_to_page(pfn
);
6891 * The HWPoisoned page may be not in buddy system, and
6892 * page_count() is not 0.
6894 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
6896 SetPageReserved(page
);
6900 BUG_ON(page_count(page
));
6901 BUG_ON(!PageBuddy(page
));
6902 order
= page_order(page
);
6903 #ifdef CONFIG_DEBUG_VM
6904 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
6905 pfn
, 1 << order
, end_pfn
);
6907 list_del(&page
->lru
);
6908 rmv_page_order(page
);
6909 zone
->free_area
[order
].nr_free
--;
6910 for (i
= 0; i
< (1 << order
); i
++)
6911 SetPageReserved((page
+i
));
6912 pfn
+= (1 << order
);
6914 spin_unlock_irqrestore(&zone
->lock
, flags
);
6918 #ifdef CONFIG_MEMORY_FAILURE
6919 bool is_free_buddy_page(struct page
*page
)
6921 struct zone
*zone
= page_zone(page
);
6922 unsigned long pfn
= page_to_pfn(page
);
6923 unsigned long flags
;
6926 spin_lock_irqsave(&zone
->lock
, flags
);
6927 for (order
= 0; order
< MAX_ORDER
; order
++) {
6928 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
6930 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
6933 spin_unlock_irqrestore(&zone
->lock
, flags
);
6935 return order
< MAX_ORDER
;