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 static void free_compound_page(struct page
*page
);
226 compound_page_dtor
* const compound_page_dtors
[] = {
229 #ifdef CONFIG_HUGETLB_PAGE
234 int min_free_kbytes
= 1024;
235 int user_min_free_kbytes
= -1;
237 static unsigned long __meminitdata nr_kernel_pages
;
238 static unsigned long __meminitdata nr_all_pages
;
239 static unsigned long __meminitdata dma_reserve
;
241 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
242 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
243 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
244 static unsigned long __initdata required_kernelcore
;
245 static unsigned long __initdata required_movablecore
;
246 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
248 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
250 EXPORT_SYMBOL(movable_zone
);
251 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
254 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
255 int nr_online_nodes __read_mostly
= 1;
256 EXPORT_SYMBOL(nr_node_ids
);
257 EXPORT_SYMBOL(nr_online_nodes
);
260 int page_group_by_mobility_disabled __read_mostly
;
262 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
263 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
265 pgdat
->first_deferred_pfn
= ULONG_MAX
;
268 /* Returns true if the struct page for the pfn is uninitialised */
269 static inline bool __meminit
early_page_uninitialised(unsigned long pfn
)
271 if (pfn
>= NODE_DATA(early_pfn_to_nid(pfn
))->first_deferred_pfn
)
277 static inline bool early_page_nid_uninitialised(unsigned long pfn
, int nid
)
279 if (pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
286 * Returns false when the remaining initialisation should be deferred until
287 * later in the boot cycle when it can be parallelised.
289 static inline bool update_defer_init(pg_data_t
*pgdat
,
290 unsigned long pfn
, unsigned long zone_end
,
291 unsigned long *nr_initialised
)
293 /* Always populate low zones for address-contrained allocations */
294 if (zone_end
< pgdat_end_pfn(pgdat
))
297 /* Initialise at least 2G of the highest zone */
299 if (*nr_initialised
> (2UL << (30 - PAGE_SHIFT
)) &&
300 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
301 pgdat
->first_deferred_pfn
= pfn
;
308 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
312 static inline bool early_page_uninitialised(unsigned long pfn
)
317 static inline bool early_page_nid_uninitialised(unsigned long pfn
, int nid
)
322 static inline bool update_defer_init(pg_data_t
*pgdat
,
323 unsigned long pfn
, unsigned long zone_end
,
324 unsigned long *nr_initialised
)
331 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
333 if (unlikely(page_group_by_mobility_disabled
&&
334 migratetype
< MIGRATE_PCPTYPES
))
335 migratetype
= MIGRATE_UNMOVABLE
;
337 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
338 PB_migrate
, PB_migrate_end
);
341 #ifdef CONFIG_DEBUG_VM
342 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
346 unsigned long pfn
= page_to_pfn(page
);
347 unsigned long sp
, start_pfn
;
350 seq
= zone_span_seqbegin(zone
);
351 start_pfn
= zone
->zone_start_pfn
;
352 sp
= zone
->spanned_pages
;
353 if (!zone_spans_pfn(zone
, pfn
))
355 } while (zone_span_seqretry(zone
, seq
));
358 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
359 pfn
, zone_to_nid(zone
), zone
->name
,
360 start_pfn
, start_pfn
+ sp
);
365 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
367 if (!pfn_valid_within(page_to_pfn(page
)))
369 if (zone
!= page_zone(page
))
375 * Temporary debugging check for pages not lying within a given zone.
377 static int bad_range(struct zone
*zone
, struct page
*page
)
379 if (page_outside_zone_boundaries(zone
, page
))
381 if (!page_is_consistent(zone
, page
))
387 static inline int bad_range(struct zone
*zone
, struct page
*page
)
393 static void bad_page(struct page
*page
, const char *reason
,
394 unsigned long bad_flags
)
396 static unsigned long resume
;
397 static unsigned long nr_shown
;
398 static unsigned long nr_unshown
;
400 /* Don't complain about poisoned pages */
401 if (PageHWPoison(page
)) {
402 page_mapcount_reset(page
); /* remove PageBuddy */
407 * Allow a burst of 60 reports, then keep quiet for that minute;
408 * or allow a steady drip of one report per second.
410 if (nr_shown
== 60) {
411 if (time_before(jiffies
, resume
)) {
417 "BUG: Bad page state: %lu messages suppressed\n",
424 resume
= jiffies
+ 60 * HZ
;
426 printk(KERN_ALERT
"BUG: Bad page state in process %s pfn:%05lx\n",
427 current
->comm
, page_to_pfn(page
));
428 dump_page_badflags(page
, reason
, bad_flags
);
433 /* Leave bad fields for debug, except PageBuddy could make trouble */
434 page_mapcount_reset(page
); /* remove PageBuddy */
435 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
439 * Higher-order pages are called "compound pages". They are structured thusly:
441 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
443 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
444 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
446 * The first tail page's ->compound_dtor holds the offset in array of compound
447 * page destructors. See compound_page_dtors.
449 * The first tail page's ->compound_order holds the order of allocation.
450 * This usage means that zero-order pages may not be compound.
453 static void free_compound_page(struct page
*page
)
455 __free_pages_ok(page
, compound_order(page
));
458 void prep_compound_page(struct page
*page
, unsigned int order
)
461 int nr_pages
= 1 << order
;
463 set_compound_page_dtor(page
, COMPOUND_PAGE_DTOR
);
464 set_compound_order(page
, order
);
466 for (i
= 1; i
< nr_pages
; i
++) {
467 struct page
*p
= page
+ i
;
468 set_page_count(p
, 0);
469 p
->mapping
= TAIL_MAPPING
;
470 set_compound_head(p
, page
);
472 atomic_set(compound_mapcount_ptr(page
), -1);
475 #ifdef CONFIG_DEBUG_PAGEALLOC
476 unsigned int _debug_guardpage_minorder
;
477 bool _debug_pagealloc_enabled __read_mostly
;
478 bool _debug_guardpage_enabled __read_mostly
;
480 static int __init
early_debug_pagealloc(char *buf
)
485 if (strcmp(buf
, "on") == 0)
486 _debug_pagealloc_enabled
= true;
490 early_param("debug_pagealloc", early_debug_pagealloc
);
492 static bool need_debug_guardpage(void)
494 /* If we don't use debug_pagealloc, we don't need guard page */
495 if (!debug_pagealloc_enabled())
501 static void init_debug_guardpage(void)
503 if (!debug_pagealloc_enabled())
506 _debug_guardpage_enabled
= true;
509 struct page_ext_operations debug_guardpage_ops
= {
510 .need
= need_debug_guardpage
,
511 .init
= init_debug_guardpage
,
514 static int __init
debug_guardpage_minorder_setup(char *buf
)
518 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
519 printk(KERN_ERR
"Bad debug_guardpage_minorder value\n");
522 _debug_guardpage_minorder
= res
;
523 printk(KERN_INFO
"Setting debug_guardpage_minorder to %lu\n", res
);
526 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
528 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
529 unsigned int order
, int migratetype
)
531 struct page_ext
*page_ext
;
533 if (!debug_guardpage_enabled())
536 page_ext
= lookup_page_ext(page
);
537 __set_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
539 INIT_LIST_HEAD(&page
->lru
);
540 set_page_private(page
, order
);
541 /* Guard pages are not available for any usage */
542 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
545 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
546 unsigned int order
, int migratetype
)
548 struct page_ext
*page_ext
;
550 if (!debug_guardpage_enabled())
553 page_ext
= lookup_page_ext(page
);
554 __clear_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
556 set_page_private(page
, 0);
557 if (!is_migrate_isolate(migratetype
))
558 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
561 struct page_ext_operations debug_guardpage_ops
= { NULL
, };
562 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
563 unsigned int order
, int migratetype
) {}
564 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
565 unsigned int order
, int migratetype
) {}
568 static inline void set_page_order(struct page
*page
, unsigned int order
)
570 set_page_private(page
, order
);
571 __SetPageBuddy(page
);
574 static inline void rmv_page_order(struct page
*page
)
576 __ClearPageBuddy(page
);
577 set_page_private(page
, 0);
581 * This function checks whether a page is free && is the buddy
582 * we can do coalesce a page and its buddy if
583 * (a) the buddy is not in a hole &&
584 * (b) the buddy is in the buddy system &&
585 * (c) a page and its buddy have the same order &&
586 * (d) a page and its buddy are in the same zone.
588 * For recording whether a page is in the buddy system, we set ->_mapcount
589 * PAGE_BUDDY_MAPCOUNT_VALUE.
590 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
591 * serialized by zone->lock.
593 * For recording page's order, we use page_private(page).
595 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
598 if (!pfn_valid_within(page_to_pfn(buddy
)))
601 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
602 if (page_zone_id(page
) != page_zone_id(buddy
))
605 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
610 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
612 * zone check is done late to avoid uselessly
613 * calculating zone/node ids for pages that could
616 if (page_zone_id(page
) != page_zone_id(buddy
))
619 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
627 * Freeing function for a buddy system allocator.
629 * The concept of a buddy system is to maintain direct-mapped table
630 * (containing bit values) for memory blocks of various "orders".
631 * The bottom level table contains the map for the smallest allocatable
632 * units of memory (here, pages), and each level above it describes
633 * pairs of units from the levels below, hence, "buddies".
634 * At a high level, all that happens here is marking the table entry
635 * at the bottom level available, and propagating the changes upward
636 * as necessary, plus some accounting needed to play nicely with other
637 * parts of the VM system.
638 * At each level, we keep a list of pages, which are heads of continuous
639 * free pages of length of (1 << order) and marked with _mapcount
640 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
642 * So when we are allocating or freeing one, we can derive the state of the
643 * other. That is, if we allocate a small block, and both were
644 * free, the remainder of the region must be split into blocks.
645 * If a block is freed, and its buddy is also free, then this
646 * triggers coalescing into a block of larger size.
651 static inline void __free_one_page(struct page
*page
,
653 struct zone
*zone
, unsigned int order
,
656 unsigned long page_idx
;
657 unsigned long combined_idx
;
658 unsigned long uninitialized_var(buddy_idx
);
660 unsigned int max_order
= MAX_ORDER
;
662 VM_BUG_ON(!zone_is_initialized(zone
));
663 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
665 VM_BUG_ON(migratetype
== -1);
666 if (is_migrate_isolate(migratetype
)) {
668 * We restrict max order of merging to prevent merge
669 * between freepages on isolate pageblock and normal
670 * pageblock. Without this, pageblock isolation
671 * could cause incorrect freepage accounting.
673 max_order
= min_t(unsigned int, MAX_ORDER
, pageblock_order
+ 1);
675 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
678 page_idx
= pfn
& ((1 << max_order
) - 1);
680 VM_BUG_ON_PAGE(page_idx
& ((1 << order
) - 1), page
);
681 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
683 while (order
< max_order
- 1) {
684 buddy_idx
= __find_buddy_index(page_idx
, order
);
685 buddy
= page
+ (buddy_idx
- page_idx
);
686 if (!page_is_buddy(page
, buddy
, order
))
689 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
690 * merge with it and move up one order.
692 if (page_is_guard(buddy
)) {
693 clear_page_guard(zone
, buddy
, order
, migratetype
);
695 list_del(&buddy
->lru
);
696 zone
->free_area
[order
].nr_free
--;
697 rmv_page_order(buddy
);
699 combined_idx
= buddy_idx
& page_idx
;
700 page
= page
+ (combined_idx
- page_idx
);
701 page_idx
= combined_idx
;
704 set_page_order(page
, order
);
707 * If this is not the largest possible page, check if the buddy
708 * of the next-highest order is free. If it is, it's possible
709 * that pages are being freed that will coalesce soon. In case,
710 * that is happening, add the free page to the tail of the list
711 * so it's less likely to be used soon and more likely to be merged
712 * as a higher order page
714 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
715 struct page
*higher_page
, *higher_buddy
;
716 combined_idx
= buddy_idx
& page_idx
;
717 higher_page
= page
+ (combined_idx
- page_idx
);
718 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
719 higher_buddy
= higher_page
+ (buddy_idx
- combined_idx
);
720 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
721 list_add_tail(&page
->lru
,
722 &zone
->free_area
[order
].free_list
[migratetype
]);
727 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
729 zone
->free_area
[order
].nr_free
++;
732 static inline int free_pages_check(struct page
*page
)
734 const char *bad_reason
= NULL
;
735 unsigned long bad_flags
= 0;
737 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
738 bad_reason
= "nonzero mapcount";
739 if (unlikely(page
->mapping
!= NULL
))
740 bad_reason
= "non-NULL mapping";
741 if (unlikely(atomic_read(&page
->_count
) != 0))
742 bad_reason
= "nonzero _count";
743 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
744 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
745 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
748 if (unlikely(page
->mem_cgroup
))
749 bad_reason
= "page still charged to cgroup";
751 if (unlikely(bad_reason
)) {
752 bad_page(page
, bad_reason
, bad_flags
);
755 page_cpupid_reset_last(page
);
756 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
757 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
762 * Frees a number of pages from the PCP lists
763 * Assumes all pages on list are in same zone, and of same order.
764 * count is the number of pages to free.
766 * If the zone was previously in an "all pages pinned" state then look to
767 * see if this freeing clears that state.
769 * And clear the zone's pages_scanned counter, to hold off the "all pages are
770 * pinned" detection logic.
772 static void free_pcppages_bulk(struct zone
*zone
, int count
,
773 struct per_cpu_pages
*pcp
)
778 unsigned long nr_scanned
;
780 spin_lock(&zone
->lock
);
781 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
783 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
787 struct list_head
*list
;
790 * Remove pages from lists in a round-robin fashion. A
791 * batch_free count is maintained that is incremented when an
792 * empty list is encountered. This is so more pages are freed
793 * off fuller lists instead of spinning excessively around empty
798 if (++migratetype
== MIGRATE_PCPTYPES
)
800 list
= &pcp
->lists
[migratetype
];
801 } while (list_empty(list
));
803 /* This is the only non-empty list. Free them all. */
804 if (batch_free
== MIGRATE_PCPTYPES
)
805 batch_free
= to_free
;
808 int mt
; /* migratetype of the to-be-freed page */
810 page
= list_last_entry(list
, struct page
, lru
);
811 /* must delete as __free_one_page list manipulates */
812 list_del(&page
->lru
);
814 mt
= get_pcppage_migratetype(page
);
815 /* MIGRATE_ISOLATE page should not go to pcplists */
816 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
817 /* Pageblock could have been isolated meanwhile */
818 if (unlikely(has_isolate_pageblock(zone
)))
819 mt
= get_pageblock_migratetype(page
);
821 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
);
822 trace_mm_page_pcpu_drain(page
, 0, mt
);
823 } while (--to_free
&& --batch_free
&& !list_empty(list
));
825 spin_unlock(&zone
->lock
);
828 static void free_one_page(struct zone
*zone
,
829 struct page
*page
, unsigned long pfn
,
833 unsigned long nr_scanned
;
834 spin_lock(&zone
->lock
);
835 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
837 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
839 if (unlikely(has_isolate_pageblock(zone
) ||
840 is_migrate_isolate(migratetype
))) {
841 migratetype
= get_pfnblock_migratetype(page
, pfn
);
843 __free_one_page(page
, pfn
, zone
, order
, migratetype
);
844 spin_unlock(&zone
->lock
);
847 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
852 * We rely page->lru.next never has bit 0 set, unless the page
853 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
855 BUILD_BUG_ON((unsigned long)LIST_POISON1
& 1);
857 if (!IS_ENABLED(CONFIG_DEBUG_VM
)) {
861 /* mapping in first tail page is used for compound_mapcount() */
862 if (page
- head_page
== 1) {
863 if (unlikely(compound_mapcount(page
))) {
864 bad_page(page
, "nonzero compound_mapcount", 0);
867 } else if (page
->mapping
!= TAIL_MAPPING
) {
868 bad_page(page
, "corrupted mapping in tail page", 0);
871 if (unlikely(!PageTail(page
))) {
872 bad_page(page
, "PageTail not set", 0);
875 if (unlikely(compound_head(page
) != head_page
)) {
876 bad_page(page
, "compound_head not consistent", 0);
881 page
->mapping
= NULL
;
882 clear_compound_head(page
);
886 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
887 unsigned long zone
, int nid
)
889 set_page_links(page
, zone
, nid
, pfn
);
890 init_page_count(page
);
891 page_mapcount_reset(page
);
892 page_cpupid_reset_last(page
);
894 INIT_LIST_HEAD(&page
->lru
);
895 #ifdef WANT_PAGE_VIRTUAL
896 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
897 if (!is_highmem_idx(zone
))
898 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
902 static void __meminit
__init_single_pfn(unsigned long pfn
, unsigned long zone
,
905 return __init_single_page(pfn_to_page(pfn
), pfn
, zone
, nid
);
908 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
909 static void init_reserved_page(unsigned long pfn
)
914 if (!early_page_uninitialised(pfn
))
917 nid
= early_pfn_to_nid(pfn
);
918 pgdat
= NODE_DATA(nid
);
920 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
921 struct zone
*zone
= &pgdat
->node_zones
[zid
];
923 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
926 __init_single_pfn(pfn
, zid
, nid
);
929 static inline void init_reserved_page(unsigned long pfn
)
932 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
935 * Initialised pages do not have PageReserved set. This function is
936 * called for each range allocated by the bootmem allocator and
937 * marks the pages PageReserved. The remaining valid pages are later
938 * sent to the buddy page allocator.
940 void __meminit
reserve_bootmem_region(unsigned long start
, unsigned long end
)
942 unsigned long start_pfn
= PFN_DOWN(start
);
943 unsigned long end_pfn
= PFN_UP(end
);
945 for (; start_pfn
< end_pfn
; start_pfn
++) {
946 if (pfn_valid(start_pfn
)) {
947 struct page
*page
= pfn_to_page(start_pfn
);
949 init_reserved_page(start_pfn
);
951 /* Avoid false-positive PageTail() */
952 INIT_LIST_HEAD(&page
->lru
);
954 SetPageReserved(page
);
959 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
961 bool compound
= PageCompound(page
);
964 VM_BUG_ON_PAGE(PageTail(page
), page
);
965 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
967 trace_mm_page_free(page
, order
);
968 kmemcheck_free_shadow(page
, order
);
969 kasan_free_pages(page
, order
);
972 page
->mapping
= NULL
;
973 bad
+= free_pages_check(page
);
974 for (i
= 1; i
< (1 << order
); i
++) {
976 bad
+= free_tail_pages_check(page
, page
+ i
);
977 bad
+= free_pages_check(page
+ i
);
982 reset_page_owner(page
, order
);
984 if (!PageHighMem(page
)) {
985 debug_check_no_locks_freed(page_address(page
),
987 debug_check_no_obj_freed(page_address(page
),
990 arch_free_page(page
, order
);
991 kernel_map_pages(page
, 1 << order
, 0);
996 static void __free_pages_ok(struct page
*page
, unsigned int order
)
1000 unsigned long pfn
= page_to_pfn(page
);
1002 if (!free_pages_prepare(page
, order
))
1005 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1006 local_irq_save(flags
);
1007 __count_vm_events(PGFREE
, 1 << order
);
1008 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
1009 local_irq_restore(flags
);
1012 static void __init
__free_pages_boot_core(struct page
*page
,
1013 unsigned long pfn
, unsigned int order
)
1015 unsigned int nr_pages
= 1 << order
;
1016 struct page
*p
= page
;
1020 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
1022 __ClearPageReserved(p
);
1023 set_page_count(p
, 0);
1025 __ClearPageReserved(p
);
1026 set_page_count(p
, 0);
1028 page_zone(page
)->managed_pages
+= nr_pages
;
1029 set_page_refcounted(page
);
1030 __free_pages(page
, order
);
1033 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1034 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1036 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1038 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1040 static DEFINE_SPINLOCK(early_pfn_lock
);
1043 spin_lock(&early_pfn_lock
);
1044 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1047 spin_unlock(&early_pfn_lock
);
1053 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1054 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1055 struct mminit_pfnnid_cache
*state
)
1059 nid
= __early_pfn_to_nid(pfn
, state
);
1060 if (nid
>= 0 && nid
!= node
)
1065 /* Only safe to use early in boot when initialisation is single-threaded */
1066 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1068 return meminit_pfn_in_nid(pfn
, node
, &early_pfnnid_cache
);
1073 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1077 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1078 struct mminit_pfnnid_cache
*state
)
1085 void __init
__free_pages_bootmem(struct page
*page
, unsigned long pfn
,
1088 if (early_page_uninitialised(pfn
))
1090 return __free_pages_boot_core(page
, pfn
, order
);
1093 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1094 static void __init
deferred_free_range(struct page
*page
,
1095 unsigned long pfn
, int nr_pages
)
1102 /* Free a large naturally-aligned chunk if possible */
1103 if (nr_pages
== MAX_ORDER_NR_PAGES
&&
1104 (pfn
& (MAX_ORDER_NR_PAGES
-1)) == 0) {
1105 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1106 __free_pages_boot_core(page
, pfn
, MAX_ORDER
-1);
1110 for (i
= 0; i
< nr_pages
; i
++, page
++, pfn
++)
1111 __free_pages_boot_core(page
, pfn
, 0);
1114 /* Completion tracking for deferred_init_memmap() threads */
1115 static atomic_t pgdat_init_n_undone __initdata
;
1116 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1118 static inline void __init
pgdat_init_report_one_done(void)
1120 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1121 complete(&pgdat_init_all_done_comp
);
1124 /* Initialise remaining memory on a node */
1125 static int __init
deferred_init_memmap(void *data
)
1127 pg_data_t
*pgdat
= data
;
1128 int nid
= pgdat
->node_id
;
1129 struct mminit_pfnnid_cache nid_init_state
= { };
1130 unsigned long start
= jiffies
;
1131 unsigned long nr_pages
= 0;
1132 unsigned long walk_start
, walk_end
;
1135 unsigned long first_init_pfn
= pgdat
->first_deferred_pfn
;
1136 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1138 if (first_init_pfn
== ULONG_MAX
) {
1139 pgdat_init_report_one_done();
1143 /* Bind memory initialisation thread to a local node if possible */
1144 if (!cpumask_empty(cpumask
))
1145 set_cpus_allowed_ptr(current
, cpumask
);
1147 /* Sanity check boundaries */
1148 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1149 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1150 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1152 /* Only the highest zone is deferred so find it */
1153 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1154 zone
= pgdat
->node_zones
+ zid
;
1155 if (first_init_pfn
< zone_end_pfn(zone
))
1159 for_each_mem_pfn_range(i
, nid
, &walk_start
, &walk_end
, NULL
) {
1160 unsigned long pfn
, end_pfn
;
1161 struct page
*page
= NULL
;
1162 struct page
*free_base_page
= NULL
;
1163 unsigned long free_base_pfn
= 0;
1166 end_pfn
= min(walk_end
, zone_end_pfn(zone
));
1167 pfn
= first_init_pfn
;
1168 if (pfn
< walk_start
)
1170 if (pfn
< zone
->zone_start_pfn
)
1171 pfn
= zone
->zone_start_pfn
;
1173 for (; pfn
< end_pfn
; pfn
++) {
1174 if (!pfn_valid_within(pfn
))
1178 * Ensure pfn_valid is checked every
1179 * MAX_ORDER_NR_PAGES for memory holes
1181 if ((pfn
& (MAX_ORDER_NR_PAGES
- 1)) == 0) {
1182 if (!pfn_valid(pfn
)) {
1188 if (!meminit_pfn_in_nid(pfn
, nid
, &nid_init_state
)) {
1193 /* Minimise pfn page lookups and scheduler checks */
1194 if (page
&& (pfn
& (MAX_ORDER_NR_PAGES
- 1)) != 0) {
1197 nr_pages
+= nr_to_free
;
1198 deferred_free_range(free_base_page
,
1199 free_base_pfn
, nr_to_free
);
1200 free_base_page
= NULL
;
1201 free_base_pfn
= nr_to_free
= 0;
1203 page
= pfn_to_page(pfn
);
1208 VM_BUG_ON(page_zone(page
) != zone
);
1212 __init_single_page(page
, pfn
, zid
, nid
);
1213 if (!free_base_page
) {
1214 free_base_page
= page
;
1215 free_base_pfn
= pfn
;
1220 /* Where possible, batch up pages for a single free */
1223 /* Free the current block of pages to allocator */
1224 nr_pages
+= nr_to_free
;
1225 deferred_free_range(free_base_page
, free_base_pfn
,
1227 free_base_page
= NULL
;
1228 free_base_pfn
= nr_to_free
= 0;
1231 first_init_pfn
= max(end_pfn
, first_init_pfn
);
1234 /* Sanity check that the next zone really is unpopulated */
1235 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1237 pr_info("node %d initialised, %lu pages in %ums\n", nid
, nr_pages
,
1238 jiffies_to_msecs(jiffies
- start
));
1240 pgdat_init_report_one_done();
1244 void __init
page_alloc_init_late(void)
1248 /* There will be num_node_state(N_MEMORY) threads */
1249 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
1250 for_each_node_state(nid
, N_MEMORY
) {
1251 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
1254 /* Block until all are initialised */
1255 wait_for_completion(&pgdat_init_all_done_comp
);
1257 /* Reinit limits that are based on free pages after the kernel is up */
1258 files_maxfiles_init();
1260 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1263 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1264 void __init
init_cma_reserved_pageblock(struct page
*page
)
1266 unsigned i
= pageblock_nr_pages
;
1267 struct page
*p
= page
;
1270 __ClearPageReserved(p
);
1271 set_page_count(p
, 0);
1274 set_pageblock_migratetype(page
, MIGRATE_CMA
);
1276 if (pageblock_order
>= MAX_ORDER
) {
1277 i
= pageblock_nr_pages
;
1280 set_page_refcounted(p
);
1281 __free_pages(p
, MAX_ORDER
- 1);
1282 p
+= MAX_ORDER_NR_PAGES
;
1283 } while (i
-= MAX_ORDER_NR_PAGES
);
1285 set_page_refcounted(page
);
1286 __free_pages(page
, pageblock_order
);
1289 adjust_managed_page_count(page
, pageblock_nr_pages
);
1294 * The order of subdivision here is critical for the IO subsystem.
1295 * Please do not alter this order without good reasons and regression
1296 * testing. Specifically, as large blocks of memory are subdivided,
1297 * the order in which smaller blocks are delivered depends on the order
1298 * they're subdivided in this function. This is the primary factor
1299 * influencing the order in which pages are delivered to the IO
1300 * subsystem according to empirical testing, and this is also justified
1301 * by considering the behavior of a buddy system containing a single
1302 * large block of memory acted on by a series of small allocations.
1303 * This behavior is a critical factor in sglist merging's success.
1307 static inline void expand(struct zone
*zone
, struct page
*page
,
1308 int low
, int high
, struct free_area
*area
,
1311 unsigned long size
= 1 << high
;
1313 while (high
> low
) {
1317 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
1319 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC
) &&
1320 debug_guardpage_enabled() &&
1321 high
< debug_guardpage_minorder()) {
1323 * Mark as guard pages (or page), that will allow to
1324 * merge back to allocator when buddy will be freed.
1325 * Corresponding page table entries will not be touched,
1326 * pages will stay not present in virtual address space
1328 set_page_guard(zone
, &page
[size
], high
, migratetype
);
1331 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
1333 set_page_order(&page
[size
], high
);
1338 * This page is about to be returned from the page allocator
1340 static inline int check_new_page(struct page
*page
)
1342 const char *bad_reason
= NULL
;
1343 unsigned long bad_flags
= 0;
1345 if (unlikely(atomic_read(&page
->_mapcount
) != -1))
1346 bad_reason
= "nonzero mapcount";
1347 if (unlikely(page
->mapping
!= NULL
))
1348 bad_reason
= "non-NULL mapping";
1349 if (unlikely(atomic_read(&page
->_count
) != 0))
1350 bad_reason
= "nonzero _count";
1351 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
1352 bad_reason
= "HWPoisoned (hardware-corrupted)";
1353 bad_flags
= __PG_HWPOISON
;
1355 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
1356 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
1357 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
1360 if (unlikely(page
->mem_cgroup
))
1361 bad_reason
= "page still charged to cgroup";
1363 if (unlikely(bad_reason
)) {
1364 bad_page(page
, bad_reason
, bad_flags
);
1370 static int prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
1375 for (i
= 0; i
< (1 << order
); i
++) {
1376 struct page
*p
= page
+ i
;
1377 if (unlikely(check_new_page(p
)))
1381 set_page_private(page
, 0);
1382 set_page_refcounted(page
);
1384 arch_alloc_page(page
, order
);
1385 kernel_map_pages(page
, 1 << order
, 1);
1386 kasan_alloc_pages(page
, order
);
1388 if (gfp_flags
& __GFP_ZERO
)
1389 for (i
= 0; i
< (1 << order
); i
++)
1390 clear_highpage(page
+ i
);
1392 if (order
&& (gfp_flags
& __GFP_COMP
))
1393 prep_compound_page(page
, order
);
1395 set_page_owner(page
, order
, gfp_flags
);
1398 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1399 * allocate the page. The expectation is that the caller is taking
1400 * steps that will free more memory. The caller should avoid the page
1401 * being used for !PFMEMALLOC purposes.
1403 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
1404 set_page_pfmemalloc(page
);
1406 clear_page_pfmemalloc(page
);
1412 * Go through the free lists for the given migratetype and remove
1413 * the smallest available page from the freelists
1416 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
1419 unsigned int current_order
;
1420 struct free_area
*area
;
1423 /* Find a page of the appropriate size in the preferred list */
1424 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
1425 area
= &(zone
->free_area
[current_order
]);
1426 page
= list_first_entry_or_null(&area
->free_list
[migratetype
],
1430 list_del(&page
->lru
);
1431 rmv_page_order(page
);
1433 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1434 set_pcppage_migratetype(page
, migratetype
);
1443 * This array describes the order lists are fallen back to when
1444 * the free lists for the desirable migrate type are depleted
1446 static int fallbacks
[MIGRATE_TYPES
][4] = {
1447 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1448 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1449 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_TYPES
},
1451 [MIGRATE_CMA
] = { MIGRATE_TYPES
}, /* Never used */
1453 #ifdef CONFIG_MEMORY_ISOLATION
1454 [MIGRATE_ISOLATE
] = { MIGRATE_TYPES
}, /* Never used */
1459 static struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1462 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
1465 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1466 unsigned int order
) { return NULL
; }
1470 * Move the free pages in a range to the free lists of the requested type.
1471 * Note that start_page and end_pages are not aligned on a pageblock
1472 * boundary. If alignment is required, use move_freepages_block()
1474 int move_freepages(struct zone
*zone
,
1475 struct page
*start_page
, struct page
*end_page
,
1480 int pages_moved
= 0;
1482 #ifndef CONFIG_HOLES_IN_ZONE
1484 * page_zone is not safe to call in this context when
1485 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1486 * anyway as we check zone boundaries in move_freepages_block().
1487 * Remove at a later date when no bug reports exist related to
1488 * grouping pages by mobility
1490 VM_BUG_ON(page_zone(start_page
) != page_zone(end_page
));
1493 for (page
= start_page
; page
<= end_page
;) {
1494 /* Make sure we are not inadvertently changing nodes */
1495 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
1497 if (!pfn_valid_within(page_to_pfn(page
))) {
1502 if (!PageBuddy(page
)) {
1507 order
= page_order(page
);
1508 list_move(&page
->lru
,
1509 &zone
->free_area
[order
].free_list
[migratetype
]);
1511 pages_moved
+= 1 << order
;
1517 int move_freepages_block(struct zone
*zone
, struct page
*page
,
1520 unsigned long start_pfn
, end_pfn
;
1521 struct page
*start_page
, *end_page
;
1523 start_pfn
= page_to_pfn(page
);
1524 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
1525 start_page
= pfn_to_page(start_pfn
);
1526 end_page
= start_page
+ pageblock_nr_pages
- 1;
1527 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
1529 /* Do not cross zone boundaries */
1530 if (!zone_spans_pfn(zone
, start_pfn
))
1532 if (!zone_spans_pfn(zone
, end_pfn
))
1535 return move_freepages(zone
, start_page
, end_page
, migratetype
);
1538 static void change_pageblock_range(struct page
*pageblock_page
,
1539 int start_order
, int migratetype
)
1541 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1543 while (nr_pageblocks
--) {
1544 set_pageblock_migratetype(pageblock_page
, migratetype
);
1545 pageblock_page
+= pageblock_nr_pages
;
1550 * When we are falling back to another migratetype during allocation, try to
1551 * steal extra free pages from the same pageblocks to satisfy further
1552 * allocations, instead of polluting multiple pageblocks.
1554 * If we are stealing a relatively large buddy page, it is likely there will
1555 * be more free pages in the pageblock, so try to steal them all. For
1556 * reclaimable and unmovable allocations, we steal regardless of page size,
1557 * as fragmentation caused by those allocations polluting movable pageblocks
1558 * is worse than movable allocations stealing from unmovable and reclaimable
1561 static bool can_steal_fallback(unsigned int order
, int start_mt
)
1564 * Leaving this order check is intended, although there is
1565 * relaxed order check in next check. The reason is that
1566 * we can actually steal whole pageblock if this condition met,
1567 * but, below check doesn't guarantee it and that is just heuristic
1568 * so could be changed anytime.
1570 if (order
>= pageblock_order
)
1573 if (order
>= pageblock_order
/ 2 ||
1574 start_mt
== MIGRATE_RECLAIMABLE
||
1575 start_mt
== MIGRATE_UNMOVABLE
||
1576 page_group_by_mobility_disabled
)
1583 * This function implements actual steal behaviour. If order is large enough,
1584 * we can steal whole pageblock. If not, we first move freepages in this
1585 * pageblock and check whether half of pages are moved or not. If half of
1586 * pages are moved, we can change migratetype of pageblock and permanently
1587 * use it's pages as requested migratetype in the future.
1589 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
1592 unsigned int current_order
= page_order(page
);
1595 /* Take ownership for orders >= pageblock_order */
1596 if (current_order
>= pageblock_order
) {
1597 change_pageblock_range(page
, current_order
, start_type
);
1601 pages
= move_freepages_block(zone
, page
, start_type
);
1603 /* Claim the whole block if over half of it is free */
1604 if (pages
>= (1 << (pageblock_order
-1)) ||
1605 page_group_by_mobility_disabled
)
1606 set_pageblock_migratetype(page
, start_type
);
1610 * Check whether there is a suitable fallback freepage with requested order.
1611 * If only_stealable is true, this function returns fallback_mt only if
1612 * we can steal other freepages all together. This would help to reduce
1613 * fragmentation due to mixed migratetype pages in one pageblock.
1615 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
1616 int migratetype
, bool only_stealable
, bool *can_steal
)
1621 if (area
->nr_free
== 0)
1626 fallback_mt
= fallbacks
[migratetype
][i
];
1627 if (fallback_mt
== MIGRATE_TYPES
)
1630 if (list_empty(&area
->free_list
[fallback_mt
]))
1633 if (can_steal_fallback(order
, migratetype
))
1636 if (!only_stealable
)
1647 * Reserve a pageblock for exclusive use of high-order atomic allocations if
1648 * there are no empty page blocks that contain a page with a suitable order
1650 static void reserve_highatomic_pageblock(struct page
*page
, struct zone
*zone
,
1651 unsigned int alloc_order
)
1654 unsigned long max_managed
, flags
;
1657 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
1658 * Check is race-prone but harmless.
1660 max_managed
= (zone
->managed_pages
/ 100) + pageblock_nr_pages
;
1661 if (zone
->nr_reserved_highatomic
>= max_managed
)
1664 spin_lock_irqsave(&zone
->lock
, flags
);
1666 /* Recheck the nr_reserved_highatomic limit under the lock */
1667 if (zone
->nr_reserved_highatomic
>= max_managed
)
1671 mt
= get_pageblock_migratetype(page
);
1672 if (mt
!= MIGRATE_HIGHATOMIC
&&
1673 !is_migrate_isolate(mt
) && !is_migrate_cma(mt
)) {
1674 zone
->nr_reserved_highatomic
+= pageblock_nr_pages
;
1675 set_pageblock_migratetype(page
, MIGRATE_HIGHATOMIC
);
1676 move_freepages_block(zone
, page
, MIGRATE_HIGHATOMIC
);
1680 spin_unlock_irqrestore(&zone
->lock
, flags
);
1684 * Used when an allocation is about to fail under memory pressure. This
1685 * potentially hurts the reliability of high-order allocations when under
1686 * intense memory pressure but failed atomic allocations should be easier
1687 * to recover from than an OOM.
1689 static void unreserve_highatomic_pageblock(const struct alloc_context
*ac
)
1691 struct zonelist
*zonelist
= ac
->zonelist
;
1692 unsigned long flags
;
1698 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
1700 /* Preserve at least one pageblock */
1701 if (zone
->nr_reserved_highatomic
<= pageblock_nr_pages
)
1704 spin_lock_irqsave(&zone
->lock
, flags
);
1705 for (order
= 0; order
< MAX_ORDER
; order
++) {
1706 struct free_area
*area
= &(zone
->free_area
[order
]);
1708 page
= list_first_entry_or_null(
1709 &area
->free_list
[MIGRATE_HIGHATOMIC
],
1715 * It should never happen but changes to locking could
1716 * inadvertently allow a per-cpu drain to add pages
1717 * to MIGRATE_HIGHATOMIC while unreserving so be safe
1718 * and watch for underflows.
1720 zone
->nr_reserved_highatomic
-= min(pageblock_nr_pages
,
1721 zone
->nr_reserved_highatomic
);
1724 * Convert to ac->migratetype and avoid the normal
1725 * pageblock stealing heuristics. Minimally, the caller
1726 * is doing the work and needs the pages. More
1727 * importantly, if the block was always converted to
1728 * MIGRATE_UNMOVABLE or another type then the number
1729 * of pageblocks that cannot be completely freed
1732 set_pageblock_migratetype(page
, ac
->migratetype
);
1733 move_freepages_block(zone
, page
, ac
->migratetype
);
1734 spin_unlock_irqrestore(&zone
->lock
, flags
);
1737 spin_unlock_irqrestore(&zone
->lock
, flags
);
1741 /* Remove an element from the buddy allocator from the fallback list */
1742 static inline struct page
*
1743 __rmqueue_fallback(struct zone
*zone
, unsigned int order
, int start_migratetype
)
1745 struct free_area
*area
;
1746 unsigned int current_order
;
1751 /* Find the largest possible block of pages in the other list */
1752 for (current_order
= MAX_ORDER
-1;
1753 current_order
>= order
&& current_order
<= MAX_ORDER
-1;
1755 area
= &(zone
->free_area
[current_order
]);
1756 fallback_mt
= find_suitable_fallback(area
, current_order
,
1757 start_migratetype
, false, &can_steal
);
1758 if (fallback_mt
== -1)
1761 page
= list_first_entry(&area
->free_list
[fallback_mt
],
1764 steal_suitable_fallback(zone
, page
, start_migratetype
);
1766 /* Remove the page from the freelists */
1768 list_del(&page
->lru
);
1769 rmv_page_order(page
);
1771 expand(zone
, page
, order
, current_order
, area
,
1774 * The pcppage_migratetype may differ from pageblock's
1775 * migratetype depending on the decisions in
1776 * find_suitable_fallback(). This is OK as long as it does not
1777 * differ for MIGRATE_CMA pageblocks. Those can be used as
1778 * fallback only via special __rmqueue_cma_fallback() function
1780 set_pcppage_migratetype(page
, start_migratetype
);
1782 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
1783 start_migratetype
, fallback_mt
);
1792 * Do the hard work of removing an element from the buddy allocator.
1793 * Call me with the zone->lock already held.
1795 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
1800 page
= __rmqueue_smallest(zone
, order
, migratetype
);
1801 if (unlikely(!page
)) {
1802 if (migratetype
== MIGRATE_MOVABLE
)
1803 page
= __rmqueue_cma_fallback(zone
, order
);
1806 page
= __rmqueue_fallback(zone
, order
, migratetype
);
1809 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1814 * Obtain a specified number of elements from the buddy allocator, all under
1815 * a single hold of the lock, for efficiency. Add them to the supplied list.
1816 * Returns the number of new pages which were placed at *list.
1818 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1819 unsigned long count
, struct list_head
*list
,
1820 int migratetype
, bool cold
)
1824 spin_lock(&zone
->lock
);
1825 for (i
= 0; i
< count
; ++i
) {
1826 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
1827 if (unlikely(page
== NULL
))
1831 * Split buddy pages returned by expand() are received here
1832 * in physical page order. The page is added to the callers and
1833 * list and the list head then moves forward. From the callers
1834 * perspective, the linked list is ordered by page number in
1835 * some conditions. This is useful for IO devices that can
1836 * merge IO requests if the physical pages are ordered
1840 list_add(&page
->lru
, list
);
1842 list_add_tail(&page
->lru
, list
);
1844 if (is_migrate_cma(get_pcppage_migratetype(page
)))
1845 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
1848 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
1849 spin_unlock(&zone
->lock
);
1855 * Called from the vmstat counter updater to drain pagesets of this
1856 * currently executing processor on remote nodes after they have
1859 * Note that this function must be called with the thread pinned to
1860 * a single processor.
1862 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
1864 unsigned long flags
;
1865 int to_drain
, batch
;
1867 local_irq_save(flags
);
1868 batch
= READ_ONCE(pcp
->batch
);
1869 to_drain
= min(pcp
->count
, batch
);
1871 free_pcppages_bulk(zone
, to_drain
, pcp
);
1872 pcp
->count
-= to_drain
;
1874 local_irq_restore(flags
);
1879 * Drain pcplists of the indicated processor and zone.
1881 * The processor must either be the current processor and the
1882 * thread pinned to the current processor or a processor that
1885 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
1887 unsigned long flags
;
1888 struct per_cpu_pageset
*pset
;
1889 struct per_cpu_pages
*pcp
;
1891 local_irq_save(flags
);
1892 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
1896 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1899 local_irq_restore(flags
);
1903 * Drain pcplists of all zones on the indicated processor.
1905 * The processor must either be the current processor and the
1906 * thread pinned to the current processor or a processor that
1909 static void drain_pages(unsigned int cpu
)
1913 for_each_populated_zone(zone
) {
1914 drain_pages_zone(cpu
, zone
);
1919 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1921 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
1922 * the single zone's pages.
1924 void drain_local_pages(struct zone
*zone
)
1926 int cpu
= smp_processor_id();
1929 drain_pages_zone(cpu
, zone
);
1935 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1937 * When zone parameter is non-NULL, spill just the single zone's pages.
1939 * Note that this code is protected against sending an IPI to an offline
1940 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1941 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1942 * nothing keeps CPUs from showing up after we populated the cpumask and
1943 * before the call to on_each_cpu_mask().
1945 void drain_all_pages(struct zone
*zone
)
1950 * Allocate in the BSS so we wont require allocation in
1951 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1953 static cpumask_t cpus_with_pcps
;
1956 * We don't care about racing with CPU hotplug event
1957 * as offline notification will cause the notified
1958 * cpu to drain that CPU pcps and on_each_cpu_mask
1959 * disables preemption as part of its processing
1961 for_each_online_cpu(cpu
) {
1962 struct per_cpu_pageset
*pcp
;
1964 bool has_pcps
= false;
1967 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
1971 for_each_populated_zone(z
) {
1972 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
1973 if (pcp
->pcp
.count
) {
1981 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
1983 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
1985 on_each_cpu_mask(&cpus_with_pcps
, (smp_call_func_t
) drain_local_pages
,
1989 #ifdef CONFIG_HIBERNATION
1991 void mark_free_pages(struct zone
*zone
)
1993 unsigned long pfn
, max_zone_pfn
;
1994 unsigned long flags
;
1995 unsigned int order
, t
;
1998 if (zone_is_empty(zone
))
2001 spin_lock_irqsave(&zone
->lock
, flags
);
2003 max_zone_pfn
= zone_end_pfn(zone
);
2004 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
2005 if (pfn_valid(pfn
)) {
2006 page
= pfn_to_page(pfn
);
2007 if (!swsusp_page_is_forbidden(page
))
2008 swsusp_unset_page_free(page
);
2011 for_each_migratetype_order(order
, t
) {
2012 list_for_each_entry(page
,
2013 &zone
->free_area
[order
].free_list
[t
], lru
) {
2016 pfn
= page_to_pfn(page
);
2017 for (i
= 0; i
< (1UL << order
); i
++)
2018 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
2021 spin_unlock_irqrestore(&zone
->lock
, flags
);
2023 #endif /* CONFIG_PM */
2026 * Free a 0-order page
2027 * cold == true ? free a cold page : free a hot page
2029 void free_hot_cold_page(struct page
*page
, bool cold
)
2031 struct zone
*zone
= page_zone(page
);
2032 struct per_cpu_pages
*pcp
;
2033 unsigned long flags
;
2034 unsigned long pfn
= page_to_pfn(page
);
2037 if (!free_pages_prepare(page
, 0))
2040 migratetype
= get_pfnblock_migratetype(page
, pfn
);
2041 set_pcppage_migratetype(page
, migratetype
);
2042 local_irq_save(flags
);
2043 __count_vm_event(PGFREE
);
2046 * We only track unmovable, reclaimable and movable on pcp lists.
2047 * Free ISOLATE pages back to the allocator because they are being
2048 * offlined but treat RESERVE as movable pages so we can get those
2049 * areas back if necessary. Otherwise, we may have to free
2050 * excessively into the page allocator
2052 if (migratetype
>= MIGRATE_PCPTYPES
) {
2053 if (unlikely(is_migrate_isolate(migratetype
))) {
2054 free_one_page(zone
, page
, pfn
, 0, migratetype
);
2057 migratetype
= MIGRATE_MOVABLE
;
2060 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2062 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
2064 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
2066 if (pcp
->count
>= pcp
->high
) {
2067 unsigned long batch
= READ_ONCE(pcp
->batch
);
2068 free_pcppages_bulk(zone
, batch
, pcp
);
2069 pcp
->count
-= batch
;
2073 local_irq_restore(flags
);
2077 * Free a list of 0-order pages
2079 void free_hot_cold_page_list(struct list_head
*list
, bool cold
)
2081 struct page
*page
, *next
;
2083 list_for_each_entry_safe(page
, next
, list
, lru
) {
2084 trace_mm_page_free_batched(page
, cold
);
2085 free_hot_cold_page(page
, cold
);
2090 * split_page takes a non-compound higher-order page, and splits it into
2091 * n (1<<order) sub-pages: page[0..n]
2092 * Each sub-page must be freed individually.
2094 * Note: this is probably too low level an operation for use in drivers.
2095 * Please consult with lkml before using this in your driver.
2097 void split_page(struct page
*page
, unsigned int order
)
2102 VM_BUG_ON_PAGE(PageCompound(page
), page
);
2103 VM_BUG_ON_PAGE(!page_count(page
), page
);
2105 #ifdef CONFIG_KMEMCHECK
2107 * Split shadow pages too, because free(page[0]) would
2108 * otherwise free the whole shadow.
2110 if (kmemcheck_page_is_tracked(page
))
2111 split_page(virt_to_page(page
[0].shadow
), order
);
2114 gfp_mask
= get_page_owner_gfp(page
);
2115 set_page_owner(page
, 0, gfp_mask
);
2116 for (i
= 1; i
< (1 << order
); i
++) {
2117 set_page_refcounted(page
+ i
);
2118 set_page_owner(page
+ i
, 0, gfp_mask
);
2121 EXPORT_SYMBOL_GPL(split_page
);
2123 int __isolate_free_page(struct page
*page
, unsigned int order
)
2125 unsigned long watermark
;
2129 BUG_ON(!PageBuddy(page
));
2131 zone
= page_zone(page
);
2132 mt
= get_pageblock_migratetype(page
);
2134 if (!is_migrate_isolate(mt
)) {
2135 /* Obey watermarks as if the page was being allocated */
2136 watermark
= low_wmark_pages(zone
) + (1 << order
);
2137 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
2140 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
2143 /* Remove page from free list */
2144 list_del(&page
->lru
);
2145 zone
->free_area
[order
].nr_free
--;
2146 rmv_page_order(page
);
2148 set_page_owner(page
, order
, __GFP_MOVABLE
);
2150 /* Set the pageblock if the isolated page is at least a pageblock */
2151 if (order
>= pageblock_order
- 1) {
2152 struct page
*endpage
= page
+ (1 << order
) - 1;
2153 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
2154 int mt
= get_pageblock_migratetype(page
);
2155 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
))
2156 set_pageblock_migratetype(page
,
2162 return 1UL << order
;
2166 * Similar to split_page except the page is already free. As this is only
2167 * being used for migration, the migratetype of the block also changes.
2168 * As this is called with interrupts disabled, the caller is responsible
2169 * for calling arch_alloc_page() and kernel_map_page() after interrupts
2172 * Note: this is probably too low level an operation for use in drivers.
2173 * Please consult with lkml before using this in your driver.
2175 int split_free_page(struct page
*page
)
2180 order
= page_order(page
);
2182 nr_pages
= __isolate_free_page(page
, order
);
2186 /* Split into individual pages */
2187 set_page_refcounted(page
);
2188 split_page(page
, order
);
2193 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2196 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
2197 struct zone
*zone
, unsigned int order
,
2198 gfp_t gfp_flags
, int alloc_flags
, int migratetype
)
2200 unsigned long flags
;
2202 bool cold
= ((gfp_flags
& __GFP_COLD
) != 0);
2204 if (likely(order
== 0)) {
2205 struct per_cpu_pages
*pcp
;
2206 struct list_head
*list
;
2208 local_irq_save(flags
);
2209 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2210 list
= &pcp
->lists
[migratetype
];
2211 if (list_empty(list
)) {
2212 pcp
->count
+= rmqueue_bulk(zone
, 0,
2215 if (unlikely(list_empty(list
)))
2220 page
= list_last_entry(list
, struct page
, lru
);
2222 page
= list_first_entry(list
, struct page
, lru
);
2224 list_del(&page
->lru
);
2227 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
2229 * __GFP_NOFAIL is not to be used in new code.
2231 * All __GFP_NOFAIL callers should be fixed so that they
2232 * properly detect and handle allocation failures.
2234 * We most definitely don't want callers attempting to
2235 * allocate greater than order-1 page units with
2238 WARN_ON_ONCE(order
> 1);
2240 spin_lock_irqsave(&zone
->lock
, flags
);
2243 if (alloc_flags
& ALLOC_HARDER
) {
2244 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
2246 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2249 page
= __rmqueue(zone
, order
, migratetype
);
2250 spin_unlock(&zone
->lock
);
2253 __mod_zone_freepage_state(zone
, -(1 << order
),
2254 get_pcppage_migratetype(page
));
2257 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
, -(1 << order
));
2258 if (atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]) <= 0 &&
2259 !test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
))
2260 set_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2262 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
2263 zone_statistics(preferred_zone
, zone
, gfp_flags
);
2264 local_irq_restore(flags
);
2266 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
2270 local_irq_restore(flags
);
2274 #ifdef CONFIG_FAIL_PAGE_ALLOC
2277 struct fault_attr attr
;
2279 bool ignore_gfp_highmem
;
2280 bool ignore_gfp_reclaim
;
2282 } fail_page_alloc
= {
2283 .attr
= FAULT_ATTR_INITIALIZER
,
2284 .ignore_gfp_reclaim
= true,
2285 .ignore_gfp_highmem
= true,
2289 static int __init
setup_fail_page_alloc(char *str
)
2291 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
2293 __setup("fail_page_alloc=", setup_fail_page_alloc
);
2295 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2297 if (order
< fail_page_alloc
.min_order
)
2299 if (gfp_mask
& __GFP_NOFAIL
)
2301 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
2303 if (fail_page_alloc
.ignore_gfp_reclaim
&&
2304 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
2307 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
2310 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2312 static int __init
fail_page_alloc_debugfs(void)
2314 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
2317 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
2318 &fail_page_alloc
.attr
);
2320 return PTR_ERR(dir
);
2322 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
2323 &fail_page_alloc
.ignore_gfp_reclaim
))
2325 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
2326 &fail_page_alloc
.ignore_gfp_highmem
))
2328 if (!debugfs_create_u32("min-order", mode
, dir
,
2329 &fail_page_alloc
.min_order
))
2334 debugfs_remove_recursive(dir
);
2339 late_initcall(fail_page_alloc_debugfs
);
2341 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2343 #else /* CONFIG_FAIL_PAGE_ALLOC */
2345 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2350 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2353 * Return true if free base pages are above 'mark'. For high-order checks it
2354 * will return true of the order-0 watermark is reached and there is at least
2355 * one free page of a suitable size. Checking now avoids taking the zone lock
2356 * to check in the allocation paths if no pages are free.
2358 static bool __zone_watermark_ok(struct zone
*z
, unsigned int order
,
2359 unsigned long mark
, int classzone_idx
, int alloc_flags
,
2364 const int alloc_harder
= (alloc_flags
& ALLOC_HARDER
);
2366 /* free_pages may go negative - that's OK */
2367 free_pages
-= (1 << order
) - 1;
2369 if (alloc_flags
& ALLOC_HIGH
)
2373 * If the caller does not have rights to ALLOC_HARDER then subtract
2374 * the high-atomic reserves. This will over-estimate the size of the
2375 * atomic reserve but it avoids a search.
2377 if (likely(!alloc_harder
))
2378 free_pages
-= z
->nr_reserved_highatomic
;
2383 /* If allocation can't use CMA areas don't use free CMA pages */
2384 if (!(alloc_flags
& ALLOC_CMA
))
2385 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2389 * Check watermarks for an order-0 allocation request. If these
2390 * are not met, then a high-order request also cannot go ahead
2391 * even if a suitable page happened to be free.
2393 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
2396 /* If this is an order-0 request then the watermark is fine */
2400 /* For a high-order request, check at least one suitable page is free */
2401 for (o
= order
; o
< MAX_ORDER
; o
++) {
2402 struct free_area
*area
= &z
->free_area
[o
];
2411 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
2412 if (!list_empty(&area
->free_list
[mt
]))
2417 if ((alloc_flags
& ALLOC_CMA
) &&
2418 !list_empty(&area
->free_list
[MIGRATE_CMA
])) {
2426 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2427 int classzone_idx
, int alloc_flags
)
2429 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
2430 zone_page_state(z
, NR_FREE_PAGES
));
2433 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
2434 unsigned long mark
, int classzone_idx
)
2436 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
2438 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
2439 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
2441 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, 0,
2446 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2448 return local_zone
->node
== zone
->node
;
2451 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2453 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <
2456 #else /* CONFIG_NUMA */
2457 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2462 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2466 #endif /* CONFIG_NUMA */
2468 static void reset_alloc_batches(struct zone
*preferred_zone
)
2470 struct zone
*zone
= preferred_zone
->zone_pgdat
->node_zones
;
2473 mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
2474 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
2475 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
2476 clear_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2477 } while (zone
++ != preferred_zone
);
2481 * get_page_from_freelist goes through the zonelist trying to allocate
2484 static struct page
*
2485 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
2486 const struct alloc_context
*ac
)
2488 struct zonelist
*zonelist
= ac
->zonelist
;
2490 struct page
*page
= NULL
;
2492 int nr_fair_skipped
= 0;
2493 bool zonelist_rescan
;
2496 zonelist_rescan
= false;
2499 * Scan zonelist, looking for a zone with enough free.
2500 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2502 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
2506 if (cpusets_enabled() &&
2507 (alloc_flags
& ALLOC_CPUSET
) &&
2508 !cpuset_zone_allowed(zone
, gfp_mask
))
2511 * Distribute pages in proportion to the individual
2512 * zone size to ensure fair page aging. The zone a
2513 * page was allocated in should have no effect on the
2514 * time the page has in memory before being reclaimed.
2516 if (alloc_flags
& ALLOC_FAIR
) {
2517 if (!zone_local(ac
->preferred_zone
, zone
))
2519 if (test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
)) {
2525 * When allocating a page cache page for writing, we
2526 * want to get it from a zone that is within its dirty
2527 * limit, such that no single zone holds more than its
2528 * proportional share of globally allowed dirty pages.
2529 * The dirty limits take into account the zone's
2530 * lowmem reserves and high watermark so that kswapd
2531 * should be able to balance it without having to
2532 * write pages from its LRU list.
2534 * This may look like it could increase pressure on
2535 * lower zones by failing allocations in higher zones
2536 * before they are full. But the pages that do spill
2537 * over are limited as the lower zones are protected
2538 * by this very same mechanism. It should not become
2539 * a practical burden to them.
2541 * XXX: For now, allow allocations to potentially
2542 * exceed the per-zone dirty limit in the slowpath
2543 * (spread_dirty_pages unset) before going into reclaim,
2544 * which is important when on a NUMA setup the allowed
2545 * zones are together not big enough to reach the
2546 * global limit. The proper fix for these situations
2547 * will require awareness of zones in the
2548 * dirty-throttling and the flusher threads.
2550 if (ac
->spread_dirty_pages
&& !zone_dirty_ok(zone
))
2553 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
2554 if (!zone_watermark_ok(zone
, order
, mark
,
2555 ac
->classzone_idx
, alloc_flags
)) {
2558 /* Checked here to keep the fast path fast */
2559 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
2560 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
2563 if (zone_reclaim_mode
== 0 ||
2564 !zone_allows_reclaim(ac
->preferred_zone
, zone
))
2567 ret
= zone_reclaim(zone
, gfp_mask
, order
);
2569 case ZONE_RECLAIM_NOSCAN
:
2572 case ZONE_RECLAIM_FULL
:
2573 /* scanned but unreclaimable */
2576 /* did we reclaim enough */
2577 if (zone_watermark_ok(zone
, order
, mark
,
2578 ac
->classzone_idx
, alloc_flags
))
2586 page
= buffered_rmqueue(ac
->preferred_zone
, zone
, order
,
2587 gfp_mask
, alloc_flags
, ac
->migratetype
);
2589 if (prep_new_page(page
, order
, gfp_mask
, alloc_flags
))
2593 * If this is a high-order atomic allocation then check
2594 * if the pageblock should be reserved for the future
2596 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
2597 reserve_highatomic_pageblock(page
, zone
, order
);
2604 * The first pass makes sure allocations are spread fairly within the
2605 * local node. However, the local node might have free pages left
2606 * after the fairness batches are exhausted, and remote zones haven't
2607 * even been considered yet. Try once more without fairness, and
2608 * include remote zones now, before entering the slowpath and waking
2609 * kswapd: prefer spilling to a remote zone over swapping locally.
2611 if (alloc_flags
& ALLOC_FAIR
) {
2612 alloc_flags
&= ~ALLOC_FAIR
;
2613 if (nr_fair_skipped
) {
2614 zonelist_rescan
= true;
2615 reset_alloc_batches(ac
->preferred_zone
);
2617 if (nr_online_nodes
> 1)
2618 zonelist_rescan
= true;
2621 if (zonelist_rescan
)
2628 * Large machines with many possible nodes should not always dump per-node
2629 * meminfo in irq context.
2631 static inline bool should_suppress_show_mem(void)
2636 ret
= in_interrupt();
2641 static DEFINE_RATELIMIT_STATE(nopage_rs
,
2642 DEFAULT_RATELIMIT_INTERVAL
,
2643 DEFAULT_RATELIMIT_BURST
);
2645 void warn_alloc_failed(gfp_t gfp_mask
, unsigned int order
, const char *fmt
, ...)
2647 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
2649 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
2650 debug_guardpage_minorder() > 0)
2654 * This documents exceptions given to allocations in certain
2655 * contexts that are allowed to allocate outside current's set
2658 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2659 if (test_thread_flag(TIF_MEMDIE
) ||
2660 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
2661 filter
&= ~SHOW_MEM_FILTER_NODES
;
2662 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
2663 filter
&= ~SHOW_MEM_FILTER_NODES
;
2666 struct va_format vaf
;
2669 va_start(args
, fmt
);
2674 pr_warn("%pV", &vaf
);
2679 pr_warn("%s: page allocation failure: order:%u, mode:0x%x\n",
2680 current
->comm
, order
, gfp_mask
);
2683 if (!should_suppress_show_mem())
2687 static inline struct page
*
2688 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
2689 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
2691 struct oom_control oc
= {
2692 .zonelist
= ac
->zonelist
,
2693 .nodemask
= ac
->nodemask
,
2694 .gfp_mask
= gfp_mask
,
2699 *did_some_progress
= 0;
2702 * Acquire the oom lock. If that fails, somebody else is
2703 * making progress for us.
2705 if (!mutex_trylock(&oom_lock
)) {
2706 *did_some_progress
= 1;
2707 schedule_timeout_uninterruptible(1);
2712 * Go through the zonelist yet one more time, keep very high watermark
2713 * here, this is only to catch a parallel oom killing, we must fail if
2714 * we're still under heavy pressure.
2716 page
= get_page_from_freelist(gfp_mask
| __GFP_HARDWALL
, order
,
2717 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
2721 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2722 /* Coredumps can quickly deplete all memory reserves */
2723 if (current
->flags
& PF_DUMPCORE
)
2725 /* The OOM killer will not help higher order allocs */
2726 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2728 /* The OOM killer does not needlessly kill tasks for lowmem */
2729 if (ac
->high_zoneidx
< ZONE_NORMAL
)
2731 /* The OOM killer does not compensate for IO-less reclaim */
2732 if (!(gfp_mask
& __GFP_FS
)) {
2734 * XXX: Page reclaim didn't yield anything,
2735 * and the OOM killer can't be invoked, but
2736 * keep looping as per tradition.
2738 *did_some_progress
= 1;
2741 if (pm_suspended_storage())
2743 /* The OOM killer may not free memory on a specific node */
2744 if (gfp_mask
& __GFP_THISNODE
)
2747 /* Exhausted what can be done so it's blamo time */
2748 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
2749 *did_some_progress
= 1;
2751 if (gfp_mask
& __GFP_NOFAIL
) {
2752 page
= get_page_from_freelist(gfp_mask
, order
,
2753 ALLOC_NO_WATERMARKS
|ALLOC_CPUSET
, ac
);
2755 * fallback to ignore cpuset restriction if our nodes
2759 page
= get_page_from_freelist(gfp_mask
, order
,
2760 ALLOC_NO_WATERMARKS
, ac
);
2764 mutex_unlock(&oom_lock
);
2768 #ifdef CONFIG_COMPACTION
2769 /* Try memory compaction for high-order allocations before reclaim */
2770 static struct page
*
2771 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2772 int alloc_flags
, const struct alloc_context
*ac
,
2773 enum migrate_mode mode
, int *contended_compaction
,
2774 bool *deferred_compaction
)
2776 unsigned long compact_result
;
2782 current
->flags
|= PF_MEMALLOC
;
2783 compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
2784 mode
, contended_compaction
);
2785 current
->flags
&= ~PF_MEMALLOC
;
2787 switch (compact_result
) {
2788 case COMPACT_DEFERRED
:
2789 *deferred_compaction
= true;
2791 case COMPACT_SKIPPED
:
2798 * At least in one zone compaction wasn't deferred or skipped, so let's
2799 * count a compaction stall
2801 count_vm_event(COMPACTSTALL
);
2803 page
= get_page_from_freelist(gfp_mask
, order
,
2804 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
2807 struct zone
*zone
= page_zone(page
);
2809 zone
->compact_blockskip_flush
= false;
2810 compaction_defer_reset(zone
, order
, true);
2811 count_vm_event(COMPACTSUCCESS
);
2816 * It's bad if compaction run occurs and fails. The most likely reason
2817 * is that pages exist, but not enough to satisfy watermarks.
2819 count_vm_event(COMPACTFAIL
);
2826 static inline struct page
*
2827 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2828 int alloc_flags
, const struct alloc_context
*ac
,
2829 enum migrate_mode mode
, int *contended_compaction
,
2830 bool *deferred_compaction
)
2834 #endif /* CONFIG_COMPACTION */
2836 /* Perform direct synchronous page reclaim */
2838 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
2839 const struct alloc_context
*ac
)
2841 struct reclaim_state reclaim_state
;
2846 /* We now go into synchronous reclaim */
2847 cpuset_memory_pressure_bump();
2848 current
->flags
|= PF_MEMALLOC
;
2849 lockdep_set_current_reclaim_state(gfp_mask
);
2850 reclaim_state
.reclaimed_slab
= 0;
2851 current
->reclaim_state
= &reclaim_state
;
2853 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
2856 current
->reclaim_state
= NULL
;
2857 lockdep_clear_current_reclaim_state();
2858 current
->flags
&= ~PF_MEMALLOC
;
2865 /* The really slow allocator path where we enter direct reclaim */
2866 static inline struct page
*
2867 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
2868 int alloc_flags
, const struct alloc_context
*ac
,
2869 unsigned long *did_some_progress
)
2871 struct page
*page
= NULL
;
2872 bool drained
= false;
2874 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
2875 if (unlikely(!(*did_some_progress
)))
2879 page
= get_page_from_freelist(gfp_mask
, order
,
2880 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
2883 * If an allocation failed after direct reclaim, it could be because
2884 * pages are pinned on the per-cpu lists or in high alloc reserves.
2885 * Shrink them them and try again
2887 if (!page
&& !drained
) {
2888 unreserve_highatomic_pageblock(ac
);
2889 drain_all_pages(NULL
);
2897 static void wake_all_kswapds(unsigned int order
, const struct alloc_context
*ac
)
2902 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
2903 ac
->high_zoneidx
, ac
->nodemask
)
2904 wakeup_kswapd(zone
, order
, zone_idx(ac
->preferred_zone
));
2908 gfp_to_alloc_flags(gfp_t gfp_mask
)
2910 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
2912 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2913 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
2916 * The caller may dip into page reserves a bit more if the caller
2917 * cannot run direct reclaim, or if the caller has realtime scheduling
2918 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2919 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
2921 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
2923 if (gfp_mask
& __GFP_ATOMIC
) {
2925 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
2926 * if it can't schedule.
2928 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2929 alloc_flags
|= ALLOC_HARDER
;
2931 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
2932 * comment for __cpuset_node_allowed().
2934 alloc_flags
&= ~ALLOC_CPUSET
;
2935 } else if (unlikely(rt_task(current
)) && !in_interrupt())
2936 alloc_flags
|= ALLOC_HARDER
;
2938 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
2939 if (gfp_mask
& __GFP_MEMALLOC
)
2940 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2941 else if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
2942 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2943 else if (!in_interrupt() &&
2944 ((current
->flags
& PF_MEMALLOC
) ||
2945 unlikely(test_thread_flag(TIF_MEMDIE
))))
2946 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2949 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
2950 alloc_flags
|= ALLOC_CMA
;
2955 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
2957 return !!(gfp_to_alloc_flags(gfp_mask
) & ALLOC_NO_WATERMARKS
);
2960 static inline bool is_thp_gfp_mask(gfp_t gfp_mask
)
2962 return (gfp_mask
& (GFP_TRANSHUGE
| __GFP_KSWAPD_RECLAIM
)) == GFP_TRANSHUGE
;
2965 static inline struct page
*
2966 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
2967 struct alloc_context
*ac
)
2969 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
2970 struct page
*page
= NULL
;
2972 unsigned long pages_reclaimed
= 0;
2973 unsigned long did_some_progress
;
2974 enum migrate_mode migration_mode
= MIGRATE_ASYNC
;
2975 bool deferred_compaction
= false;
2976 int contended_compaction
= COMPACT_CONTENDED_NONE
;
2979 * In the slowpath, we sanity check order to avoid ever trying to
2980 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2981 * be using allocators in order of preference for an area that is
2984 if (order
>= MAX_ORDER
) {
2985 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
2990 * We also sanity check to catch abuse of atomic reserves being used by
2991 * callers that are not in atomic context.
2993 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
2994 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
2995 gfp_mask
&= ~__GFP_ATOMIC
;
2998 * If this allocation cannot block and it is for a specific node, then
2999 * fail early. There's no need to wakeup kswapd or retry for a
3000 * speculative node-specific allocation.
3002 if (IS_ENABLED(CONFIG_NUMA
) && (gfp_mask
& __GFP_THISNODE
) && !can_direct_reclaim
)
3006 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3007 wake_all_kswapds(order
, ac
);
3010 * OK, we're below the kswapd watermark and have kicked background
3011 * reclaim. Now things get more complex, so set up alloc_flags according
3012 * to how we want to proceed.
3014 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
3017 * Find the true preferred zone if the allocation is unconstrained by
3020 if (!(alloc_flags
& ALLOC_CPUSET
) && !ac
->nodemask
) {
3021 struct zoneref
*preferred_zoneref
;
3022 preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3023 ac
->high_zoneidx
, NULL
, &ac
->preferred_zone
);
3024 ac
->classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
3027 /* This is the last chance, in general, before the goto nopage. */
3028 page
= get_page_from_freelist(gfp_mask
, order
,
3029 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3033 /* Allocate without watermarks if the context allows */
3034 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
3036 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
3037 * the allocation is high priority and these type of
3038 * allocations are system rather than user orientated
3040 ac
->zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
3041 page
= get_page_from_freelist(gfp_mask
, order
,
3042 ALLOC_NO_WATERMARKS
, ac
);
3047 /* Caller is not willing to reclaim, we can't balance anything */
3048 if (!can_direct_reclaim
) {
3050 * All existing users of the __GFP_NOFAIL are blockable, so warn
3051 * of any new users that actually allow this type of allocation
3054 WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
);
3058 /* Avoid recursion of direct reclaim */
3059 if (current
->flags
& PF_MEMALLOC
) {
3061 * __GFP_NOFAIL request from this context is rather bizarre
3062 * because we cannot reclaim anything and only can loop waiting
3063 * for somebody to do a work for us.
3065 if (WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
)) {
3072 /* Avoid allocations with no watermarks from looping endlessly */
3073 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
3077 * Try direct compaction. The first pass is asynchronous. Subsequent
3078 * attempts after direct reclaim are synchronous
3080 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
3082 &contended_compaction
,
3083 &deferred_compaction
);
3087 /* Checks for THP-specific high-order allocations */
3088 if (is_thp_gfp_mask(gfp_mask
)) {
3090 * If compaction is deferred for high-order allocations, it is
3091 * because sync compaction recently failed. If this is the case
3092 * and the caller requested a THP allocation, we do not want
3093 * to heavily disrupt the system, so we fail the allocation
3094 * instead of entering direct reclaim.
3096 if (deferred_compaction
)
3100 * In all zones where compaction was attempted (and not
3101 * deferred or skipped), lock contention has been detected.
3102 * For THP allocation we do not want to disrupt the others
3103 * so we fallback to base pages instead.
3105 if (contended_compaction
== COMPACT_CONTENDED_LOCK
)
3109 * If compaction was aborted due to need_resched(), we do not
3110 * want to further increase allocation latency, unless it is
3111 * khugepaged trying to collapse.
3113 if (contended_compaction
== COMPACT_CONTENDED_SCHED
3114 && !(current
->flags
& PF_KTHREAD
))
3119 * It can become very expensive to allocate transparent hugepages at
3120 * fault, so use asynchronous memory compaction for THP unless it is
3121 * khugepaged trying to collapse.
3123 if (!is_thp_gfp_mask(gfp_mask
) || (current
->flags
& PF_KTHREAD
))
3124 migration_mode
= MIGRATE_SYNC_LIGHT
;
3126 /* Try direct reclaim and then allocating */
3127 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
3128 &did_some_progress
);
3132 /* Do not loop if specifically requested */
3133 if (gfp_mask
& __GFP_NORETRY
)
3136 /* Keep reclaiming pages as long as there is reasonable progress */
3137 pages_reclaimed
+= did_some_progress
;
3138 if ((did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
) ||
3139 ((gfp_mask
& __GFP_REPEAT
) && pages_reclaimed
< (1 << order
))) {
3140 /* Wait for some write requests to complete then retry */
3141 wait_iff_congested(ac
->preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
3145 /* Reclaim has failed us, start killing things */
3146 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
3150 /* Retry as long as the OOM killer is making progress */
3151 if (did_some_progress
)
3156 * High-order allocations do not necessarily loop after
3157 * direct reclaim and reclaim/compaction depends on compaction
3158 * being called after reclaim so call directly if necessary
3160 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
,
3162 &contended_compaction
,
3163 &deferred_compaction
);
3167 warn_alloc_failed(gfp_mask
, order
, NULL
);
3173 * This is the 'heart' of the zoned buddy allocator.
3176 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
3177 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
3179 struct zoneref
*preferred_zoneref
;
3180 struct page
*page
= NULL
;
3181 unsigned int cpuset_mems_cookie
;
3182 int alloc_flags
= ALLOC_WMARK_LOW
|ALLOC_CPUSET
|ALLOC_FAIR
;
3183 gfp_t alloc_mask
; /* The gfp_t that was actually used for allocation */
3184 struct alloc_context ac
= {
3185 .high_zoneidx
= gfp_zone(gfp_mask
),
3186 .nodemask
= nodemask
,
3187 .migratetype
= gfpflags_to_migratetype(gfp_mask
),
3190 gfp_mask
&= gfp_allowed_mask
;
3192 lockdep_trace_alloc(gfp_mask
);
3194 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
3196 if (should_fail_alloc_page(gfp_mask
, order
))
3200 * Check the zones suitable for the gfp_mask contain at least one
3201 * valid zone. It's possible to have an empty zonelist as a result
3202 * of __GFP_THISNODE and a memoryless node
3204 if (unlikely(!zonelist
->_zonerefs
->zone
))
3207 if (IS_ENABLED(CONFIG_CMA
) && ac
.migratetype
== MIGRATE_MOVABLE
)
3208 alloc_flags
|= ALLOC_CMA
;
3211 cpuset_mems_cookie
= read_mems_allowed_begin();
3213 /* We set it here, as __alloc_pages_slowpath might have changed it */
3214 ac
.zonelist
= zonelist
;
3216 /* Dirty zone balancing only done in the fast path */
3217 ac
.spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
3219 /* The preferred zone is used for statistics later */
3220 preferred_zoneref
= first_zones_zonelist(ac
.zonelist
, ac
.high_zoneidx
,
3221 ac
.nodemask
? : &cpuset_current_mems_allowed
,
3222 &ac
.preferred_zone
);
3223 if (!ac
.preferred_zone
)
3225 ac
.classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
3227 /* First allocation attempt */
3228 alloc_mask
= gfp_mask
|__GFP_HARDWALL
;
3229 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
3230 if (unlikely(!page
)) {
3232 * Runtime PM, block IO and its error handling path
3233 * can deadlock because I/O on the device might not
3236 alloc_mask
= memalloc_noio_flags(gfp_mask
);
3237 ac
.spread_dirty_pages
= false;
3239 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
3242 if (kmemcheck_enabled
&& page
)
3243 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
3245 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
3249 * When updating a task's mems_allowed, it is possible to race with
3250 * parallel threads in such a way that an allocation can fail while
3251 * the mask is being updated. If a page allocation is about to fail,
3252 * check if the cpuset changed during allocation and if so, retry.
3254 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
)))
3259 EXPORT_SYMBOL(__alloc_pages_nodemask
);
3262 * Common helper functions.
3264 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
3269 * __get_free_pages() returns a 32-bit address, which cannot represent
3272 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
3274 page
= alloc_pages(gfp_mask
, order
);
3277 return (unsigned long) page_address(page
);
3279 EXPORT_SYMBOL(__get_free_pages
);
3281 unsigned long get_zeroed_page(gfp_t gfp_mask
)
3283 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
3285 EXPORT_SYMBOL(get_zeroed_page
);
3287 void __free_pages(struct page
*page
, unsigned int order
)
3289 if (put_page_testzero(page
)) {
3291 free_hot_cold_page(page
, false);
3293 __free_pages_ok(page
, order
);
3297 EXPORT_SYMBOL(__free_pages
);
3299 void free_pages(unsigned long addr
, unsigned int order
)
3302 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3303 __free_pages(virt_to_page((void *)addr
), order
);
3307 EXPORT_SYMBOL(free_pages
);
3311 * An arbitrary-length arbitrary-offset area of memory which resides
3312 * within a 0 or higher order page. Multiple fragments within that page
3313 * are individually refcounted, in the page's reference counter.
3315 * The page_frag functions below provide a simple allocation framework for
3316 * page fragments. This is used by the network stack and network device
3317 * drivers to provide a backing region of memory for use as either an
3318 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3320 static struct page
*__page_frag_refill(struct page_frag_cache
*nc
,
3323 struct page
*page
= NULL
;
3324 gfp_t gfp
= gfp_mask
;
3326 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3327 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
3329 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
3330 PAGE_FRAG_CACHE_MAX_ORDER
);
3331 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
3333 if (unlikely(!page
))
3334 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
3336 nc
->va
= page
? page_address(page
) : NULL
;
3341 void *__alloc_page_frag(struct page_frag_cache
*nc
,
3342 unsigned int fragsz
, gfp_t gfp_mask
)
3344 unsigned int size
= PAGE_SIZE
;
3348 if (unlikely(!nc
->va
)) {
3350 page
= __page_frag_refill(nc
, gfp_mask
);
3354 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3355 /* if size can vary use size else just use PAGE_SIZE */
3358 /* Even if we own the page, we do not use atomic_set().
3359 * This would break get_page_unless_zero() users.
3361 atomic_add(size
- 1, &page
->_count
);
3363 /* reset page count bias and offset to start of new frag */
3364 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
3365 nc
->pagecnt_bias
= size
;
3369 offset
= nc
->offset
- fragsz
;
3370 if (unlikely(offset
< 0)) {
3371 page
= virt_to_page(nc
->va
);
3373 if (!atomic_sub_and_test(nc
->pagecnt_bias
, &page
->_count
))
3376 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3377 /* if size can vary use size else just use PAGE_SIZE */
3380 /* OK, page count is 0, we can safely set it */
3381 atomic_set(&page
->_count
, size
);
3383 /* reset page count bias and offset to start of new frag */
3384 nc
->pagecnt_bias
= size
;
3385 offset
= size
- fragsz
;
3389 nc
->offset
= offset
;
3391 return nc
->va
+ offset
;
3393 EXPORT_SYMBOL(__alloc_page_frag
);
3396 * Frees a page fragment allocated out of either a compound or order 0 page.
3398 void __free_page_frag(void *addr
)
3400 struct page
*page
= virt_to_head_page(addr
);
3402 if (unlikely(put_page_testzero(page
)))
3403 __free_pages_ok(page
, compound_order(page
));
3405 EXPORT_SYMBOL(__free_page_frag
);
3408 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
3409 * of the current memory cgroup if __GFP_ACCOUNT is set, other than that it is
3410 * equivalent to alloc_pages.
3412 * It should be used when the caller would like to use kmalloc, but since the
3413 * allocation is large, it has to fall back to the page allocator.
3415 struct page
*alloc_kmem_pages(gfp_t gfp_mask
, unsigned int order
)
3419 page
= alloc_pages(gfp_mask
, order
);
3420 if (page
&& memcg_kmem_charge(page
, gfp_mask
, order
) != 0) {
3421 __free_pages(page
, order
);
3427 struct page
*alloc_kmem_pages_node(int nid
, gfp_t gfp_mask
, unsigned int order
)
3431 page
= alloc_pages_node(nid
, gfp_mask
, order
);
3432 if (page
&& memcg_kmem_charge(page
, gfp_mask
, order
) != 0) {
3433 __free_pages(page
, order
);
3440 * __free_kmem_pages and free_kmem_pages will free pages allocated with
3443 void __free_kmem_pages(struct page
*page
, unsigned int order
)
3445 memcg_kmem_uncharge(page
, order
);
3446 __free_pages(page
, order
);
3449 void free_kmem_pages(unsigned long addr
, unsigned int order
)
3452 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3453 __free_kmem_pages(virt_to_page((void *)addr
), order
);
3457 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
3461 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
3462 unsigned long used
= addr
+ PAGE_ALIGN(size
);
3464 split_page(virt_to_page((void *)addr
), order
);
3465 while (used
< alloc_end
) {
3470 return (void *)addr
;
3474 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
3475 * @size: the number of bytes to allocate
3476 * @gfp_mask: GFP flags for the allocation
3478 * This function is similar to alloc_pages(), except that it allocates the
3479 * minimum number of pages to satisfy the request. alloc_pages() can only
3480 * allocate memory in power-of-two pages.
3482 * This function is also limited by MAX_ORDER.
3484 * Memory allocated by this function must be released by free_pages_exact().
3486 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
3488 unsigned int order
= get_order(size
);
3491 addr
= __get_free_pages(gfp_mask
, order
);
3492 return make_alloc_exact(addr
, order
, size
);
3494 EXPORT_SYMBOL(alloc_pages_exact
);
3497 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3499 * @nid: the preferred node ID where memory should be allocated
3500 * @size: the number of bytes to allocate
3501 * @gfp_mask: GFP flags for the allocation
3503 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3506 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
3508 unsigned int order
= get_order(size
);
3509 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
3512 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
3516 * free_pages_exact - release memory allocated via alloc_pages_exact()
3517 * @virt: the value returned by alloc_pages_exact.
3518 * @size: size of allocation, same value as passed to alloc_pages_exact().
3520 * Release the memory allocated by a previous call to alloc_pages_exact.
3522 void free_pages_exact(void *virt
, size_t size
)
3524 unsigned long addr
= (unsigned long)virt
;
3525 unsigned long end
= addr
+ PAGE_ALIGN(size
);
3527 while (addr
< end
) {
3532 EXPORT_SYMBOL(free_pages_exact
);
3535 * nr_free_zone_pages - count number of pages beyond high watermark
3536 * @offset: The zone index of the highest zone
3538 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3539 * high watermark within all zones at or below a given zone index. For each
3540 * zone, the number of pages is calculated as:
3541 * managed_pages - high_pages
3543 static unsigned long nr_free_zone_pages(int offset
)
3548 /* Just pick one node, since fallback list is circular */
3549 unsigned long sum
= 0;
3551 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
3553 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
3554 unsigned long size
= zone
->managed_pages
;
3555 unsigned long high
= high_wmark_pages(zone
);
3564 * nr_free_buffer_pages - count number of pages beyond high watermark
3566 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3567 * watermark within ZONE_DMA and ZONE_NORMAL.
3569 unsigned long nr_free_buffer_pages(void)
3571 return nr_free_zone_pages(gfp_zone(GFP_USER
));
3573 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
3576 * nr_free_pagecache_pages - count number of pages beyond high watermark
3578 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3579 * high watermark within all zones.
3581 unsigned long nr_free_pagecache_pages(void)
3583 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
3586 static inline void show_node(struct zone
*zone
)
3588 if (IS_ENABLED(CONFIG_NUMA
))
3589 printk("Node %d ", zone_to_nid(zone
));
3592 void si_meminfo(struct sysinfo
*val
)
3594 val
->totalram
= totalram_pages
;
3595 val
->sharedram
= global_page_state(NR_SHMEM
);
3596 val
->freeram
= global_page_state(NR_FREE_PAGES
);
3597 val
->bufferram
= nr_blockdev_pages();
3598 val
->totalhigh
= totalhigh_pages
;
3599 val
->freehigh
= nr_free_highpages();
3600 val
->mem_unit
= PAGE_SIZE
;
3603 EXPORT_SYMBOL(si_meminfo
);
3606 void si_meminfo_node(struct sysinfo
*val
, int nid
)
3608 int zone_type
; /* needs to be signed */
3609 unsigned long managed_pages
= 0;
3610 pg_data_t
*pgdat
= NODE_DATA(nid
);
3612 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
3613 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
3614 val
->totalram
= managed_pages
;
3615 val
->sharedram
= node_page_state(nid
, NR_SHMEM
);
3616 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
3617 #ifdef CONFIG_HIGHMEM
3618 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].managed_pages
;
3619 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
3625 val
->mem_unit
= PAGE_SIZE
;
3630 * Determine whether the node should be displayed or not, depending on whether
3631 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3633 bool skip_free_areas_node(unsigned int flags
, int nid
)
3636 unsigned int cpuset_mems_cookie
;
3638 if (!(flags
& SHOW_MEM_FILTER_NODES
))
3642 cpuset_mems_cookie
= read_mems_allowed_begin();
3643 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
3644 } while (read_mems_allowed_retry(cpuset_mems_cookie
));
3649 #define K(x) ((x) << (PAGE_SHIFT-10))
3651 static void show_migration_types(unsigned char type
)
3653 static const char types
[MIGRATE_TYPES
] = {
3654 [MIGRATE_UNMOVABLE
] = 'U',
3655 [MIGRATE_MOVABLE
] = 'M',
3656 [MIGRATE_RECLAIMABLE
] = 'E',
3657 [MIGRATE_HIGHATOMIC
] = 'H',
3659 [MIGRATE_CMA
] = 'C',
3661 #ifdef CONFIG_MEMORY_ISOLATION
3662 [MIGRATE_ISOLATE
] = 'I',
3665 char tmp
[MIGRATE_TYPES
+ 1];
3669 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
3670 if (type
& (1 << i
))
3675 printk("(%s) ", tmp
);
3679 * Show free area list (used inside shift_scroll-lock stuff)
3680 * We also calculate the percentage fragmentation. We do this by counting the
3681 * memory on each free list with the exception of the first item on the list.
3684 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
3687 void show_free_areas(unsigned int filter
)
3689 unsigned long free_pcp
= 0;
3693 for_each_populated_zone(zone
) {
3694 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3697 for_each_online_cpu(cpu
)
3698 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
3701 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3702 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3703 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
3704 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3705 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3706 " free:%lu free_pcp:%lu free_cma:%lu\n",
3707 global_page_state(NR_ACTIVE_ANON
),
3708 global_page_state(NR_INACTIVE_ANON
),
3709 global_page_state(NR_ISOLATED_ANON
),
3710 global_page_state(NR_ACTIVE_FILE
),
3711 global_page_state(NR_INACTIVE_FILE
),
3712 global_page_state(NR_ISOLATED_FILE
),
3713 global_page_state(NR_UNEVICTABLE
),
3714 global_page_state(NR_FILE_DIRTY
),
3715 global_page_state(NR_WRITEBACK
),
3716 global_page_state(NR_UNSTABLE_NFS
),
3717 global_page_state(NR_SLAB_RECLAIMABLE
),
3718 global_page_state(NR_SLAB_UNRECLAIMABLE
),
3719 global_page_state(NR_FILE_MAPPED
),
3720 global_page_state(NR_SHMEM
),
3721 global_page_state(NR_PAGETABLE
),
3722 global_page_state(NR_BOUNCE
),
3723 global_page_state(NR_FREE_PAGES
),
3725 global_page_state(NR_FREE_CMA_PAGES
));
3727 for_each_populated_zone(zone
) {
3730 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3734 for_each_online_cpu(cpu
)
3735 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
3743 " active_anon:%lukB"
3744 " inactive_anon:%lukB"
3745 " active_file:%lukB"
3746 " inactive_file:%lukB"
3747 " unevictable:%lukB"
3748 " isolated(anon):%lukB"
3749 " isolated(file):%lukB"
3757 " slab_reclaimable:%lukB"
3758 " slab_unreclaimable:%lukB"
3759 " kernel_stack:%lukB"
3766 " writeback_tmp:%lukB"
3767 " pages_scanned:%lu"
3768 " all_unreclaimable? %s"
3771 K(zone_page_state(zone
, NR_FREE_PAGES
)),
3772 K(min_wmark_pages(zone
)),
3773 K(low_wmark_pages(zone
)),
3774 K(high_wmark_pages(zone
)),
3775 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
3776 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
3777 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
3778 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
3779 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
3780 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
3781 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
3782 K(zone
->present_pages
),
3783 K(zone
->managed_pages
),
3784 K(zone_page_state(zone
, NR_MLOCK
)),
3785 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
3786 K(zone_page_state(zone
, NR_WRITEBACK
)),
3787 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
3788 K(zone_page_state(zone
, NR_SHMEM
)),
3789 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
3790 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
3791 zone_page_state(zone
, NR_KERNEL_STACK
) *
3793 K(zone_page_state(zone
, NR_PAGETABLE
)),
3794 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
3795 K(zone_page_state(zone
, NR_BOUNCE
)),
3797 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
3798 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)),
3799 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
3800 K(zone_page_state(zone
, NR_PAGES_SCANNED
)),
3801 (!zone_reclaimable(zone
) ? "yes" : "no")
3803 printk("lowmem_reserve[]:");
3804 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3805 printk(" %ld", zone
->lowmem_reserve
[i
]);
3809 for_each_populated_zone(zone
) {
3811 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
3812 unsigned char types
[MAX_ORDER
];
3814 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3817 printk("%s: ", zone
->name
);
3819 spin_lock_irqsave(&zone
->lock
, flags
);
3820 for (order
= 0; order
< MAX_ORDER
; order
++) {
3821 struct free_area
*area
= &zone
->free_area
[order
];
3824 nr
[order
] = area
->nr_free
;
3825 total
+= nr
[order
] << order
;
3828 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
3829 if (!list_empty(&area
->free_list
[type
]))
3830 types
[order
] |= 1 << type
;
3833 spin_unlock_irqrestore(&zone
->lock
, flags
);
3834 for (order
= 0; order
< MAX_ORDER
; order
++) {
3835 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
3837 show_migration_types(types
[order
]);
3839 printk("= %lukB\n", K(total
));
3842 hugetlb_show_meminfo();
3844 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
3846 show_swap_cache_info();
3849 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
3851 zoneref
->zone
= zone
;
3852 zoneref
->zone_idx
= zone_idx(zone
);
3856 * Builds allocation fallback zone lists.
3858 * Add all populated zones of a node to the zonelist.
3860 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
3864 enum zone_type zone_type
= MAX_NR_ZONES
;
3868 zone
= pgdat
->node_zones
+ zone_type
;
3869 if (populated_zone(zone
)) {
3870 zoneref_set_zone(zone
,
3871 &zonelist
->_zonerefs
[nr_zones
++]);
3872 check_highest_zone(zone_type
);
3874 } while (zone_type
);
3882 * 0 = automatic detection of better ordering.
3883 * 1 = order by ([node] distance, -zonetype)
3884 * 2 = order by (-zonetype, [node] distance)
3886 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3887 * the same zonelist. So only NUMA can configure this param.
3889 #define ZONELIST_ORDER_DEFAULT 0
3890 #define ZONELIST_ORDER_NODE 1
3891 #define ZONELIST_ORDER_ZONE 2
3893 /* zonelist order in the kernel.
3894 * set_zonelist_order() will set this to NODE or ZONE.
3896 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3897 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
3901 /* The value user specified ....changed by config */
3902 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3903 /* string for sysctl */
3904 #define NUMA_ZONELIST_ORDER_LEN 16
3905 char numa_zonelist_order
[16] = "default";
3908 * interface for configure zonelist ordering.
3909 * command line option "numa_zonelist_order"
3910 * = "[dD]efault - default, automatic configuration.
3911 * = "[nN]ode - order by node locality, then by zone within node
3912 * = "[zZ]one - order by zone, then by locality within zone
3915 static int __parse_numa_zonelist_order(char *s
)
3917 if (*s
== 'd' || *s
== 'D') {
3918 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3919 } else if (*s
== 'n' || *s
== 'N') {
3920 user_zonelist_order
= ZONELIST_ORDER_NODE
;
3921 } else if (*s
== 'z' || *s
== 'Z') {
3922 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
3925 "Ignoring invalid numa_zonelist_order value: "
3932 static __init
int setup_numa_zonelist_order(char *s
)
3939 ret
= __parse_numa_zonelist_order(s
);
3941 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
3945 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
3948 * sysctl handler for numa_zonelist_order
3950 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
3951 void __user
*buffer
, size_t *length
,
3954 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
3956 static DEFINE_MUTEX(zl_order_mutex
);
3958 mutex_lock(&zl_order_mutex
);
3960 if (strlen((char *)table
->data
) >= NUMA_ZONELIST_ORDER_LEN
) {
3964 strcpy(saved_string
, (char *)table
->data
);
3966 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
3970 int oldval
= user_zonelist_order
;
3972 ret
= __parse_numa_zonelist_order((char *)table
->data
);
3975 * bogus value. restore saved string
3977 strncpy((char *)table
->data
, saved_string
,
3978 NUMA_ZONELIST_ORDER_LEN
);
3979 user_zonelist_order
= oldval
;
3980 } else if (oldval
!= user_zonelist_order
) {
3981 mutex_lock(&zonelists_mutex
);
3982 build_all_zonelists(NULL
, NULL
);
3983 mutex_unlock(&zonelists_mutex
);
3987 mutex_unlock(&zl_order_mutex
);
3992 #define MAX_NODE_LOAD (nr_online_nodes)
3993 static int node_load
[MAX_NUMNODES
];
3996 * find_next_best_node - find the next node that should appear in a given node's fallback list
3997 * @node: node whose fallback list we're appending
3998 * @used_node_mask: nodemask_t of already used nodes
4000 * We use a number of factors to determine which is the next node that should
4001 * appear on a given node's fallback list. The node should not have appeared
4002 * already in @node's fallback list, and it should be the next closest node
4003 * according to the distance array (which contains arbitrary distance values
4004 * from each node to each node in the system), and should also prefer nodes
4005 * with no CPUs, since presumably they'll have very little allocation pressure
4006 * on them otherwise.
4007 * It returns -1 if no node is found.
4009 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
4012 int min_val
= INT_MAX
;
4013 int best_node
= NUMA_NO_NODE
;
4014 const struct cpumask
*tmp
= cpumask_of_node(0);
4016 /* Use the local node if we haven't already */
4017 if (!node_isset(node
, *used_node_mask
)) {
4018 node_set(node
, *used_node_mask
);
4022 for_each_node_state(n
, N_MEMORY
) {
4024 /* Don't want a node to appear more than once */
4025 if (node_isset(n
, *used_node_mask
))
4028 /* Use the distance array to find the distance */
4029 val
= node_distance(node
, n
);
4031 /* Penalize nodes under us ("prefer the next node") */
4034 /* Give preference to headless and unused nodes */
4035 tmp
= cpumask_of_node(n
);
4036 if (!cpumask_empty(tmp
))
4037 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
4039 /* Slight preference for less loaded node */
4040 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
4041 val
+= node_load
[n
];
4043 if (val
< min_val
) {
4050 node_set(best_node
, *used_node_mask
);
4057 * Build zonelists ordered by node and zones within node.
4058 * This results in maximum locality--normal zone overflows into local
4059 * DMA zone, if any--but risks exhausting DMA zone.
4061 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
4064 struct zonelist
*zonelist
;
4066 zonelist
= &pgdat
->node_zonelists
[0];
4067 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
4069 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4070 zonelist
->_zonerefs
[j
].zone
= NULL
;
4071 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4075 * Build gfp_thisnode zonelists
4077 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
4080 struct zonelist
*zonelist
;
4082 zonelist
= &pgdat
->node_zonelists
[1];
4083 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4084 zonelist
->_zonerefs
[j
].zone
= NULL
;
4085 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4089 * Build zonelists ordered by zone and nodes within zones.
4090 * This results in conserving DMA zone[s] until all Normal memory is
4091 * exhausted, but results in overflowing to remote node while memory
4092 * may still exist in local DMA zone.
4094 static int node_order
[MAX_NUMNODES
];
4096 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
4099 int zone_type
; /* needs to be signed */
4101 struct zonelist
*zonelist
;
4103 zonelist
= &pgdat
->node_zonelists
[0];
4105 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
4106 for (j
= 0; j
< nr_nodes
; j
++) {
4107 node
= node_order
[j
];
4108 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
4109 if (populated_zone(z
)) {
4111 &zonelist
->_zonerefs
[pos
++]);
4112 check_highest_zone(zone_type
);
4116 zonelist
->_zonerefs
[pos
].zone
= NULL
;
4117 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
4120 #if defined(CONFIG_64BIT)
4122 * Devices that require DMA32/DMA are relatively rare and do not justify a
4123 * penalty to every machine in case the specialised case applies. Default
4124 * to Node-ordering on 64-bit NUMA machines
4126 static int default_zonelist_order(void)
4128 return ZONELIST_ORDER_NODE
;
4132 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4133 * by the kernel. If processes running on node 0 deplete the low memory zone
4134 * then reclaim will occur more frequency increasing stalls and potentially
4135 * be easier to OOM if a large percentage of the zone is under writeback or
4136 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4137 * Hence, default to zone ordering on 32-bit.
4139 static int default_zonelist_order(void)
4141 return ZONELIST_ORDER_ZONE
;
4143 #endif /* CONFIG_64BIT */
4145 static void set_zonelist_order(void)
4147 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
4148 current_zonelist_order
= default_zonelist_order();
4150 current_zonelist_order
= user_zonelist_order
;
4153 static void build_zonelists(pg_data_t
*pgdat
)
4156 nodemask_t used_mask
;
4157 int local_node
, prev_node
;
4158 struct zonelist
*zonelist
;
4159 unsigned int order
= current_zonelist_order
;
4161 /* initialize zonelists */
4162 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
4163 zonelist
= pgdat
->node_zonelists
+ i
;
4164 zonelist
->_zonerefs
[0].zone
= NULL
;
4165 zonelist
->_zonerefs
[0].zone_idx
= 0;
4168 /* NUMA-aware ordering of nodes */
4169 local_node
= pgdat
->node_id
;
4170 load
= nr_online_nodes
;
4171 prev_node
= local_node
;
4172 nodes_clear(used_mask
);
4174 memset(node_order
, 0, sizeof(node_order
));
4177 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
4179 * We don't want to pressure a particular node.
4180 * So adding penalty to the first node in same
4181 * distance group to make it round-robin.
4183 if (node_distance(local_node
, node
) !=
4184 node_distance(local_node
, prev_node
))
4185 node_load
[node
] = load
;
4189 if (order
== ZONELIST_ORDER_NODE
)
4190 build_zonelists_in_node_order(pgdat
, node
);
4192 node_order
[i
++] = node
; /* remember order */
4195 if (order
== ZONELIST_ORDER_ZONE
) {
4196 /* calculate node order -- i.e., DMA last! */
4197 build_zonelists_in_zone_order(pgdat
, i
);
4200 build_thisnode_zonelists(pgdat
);
4203 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4205 * Return node id of node used for "local" allocations.
4206 * I.e., first node id of first zone in arg node's generic zonelist.
4207 * Used for initializing percpu 'numa_mem', which is used primarily
4208 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4210 int local_memory_node(int node
)
4214 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
4215 gfp_zone(GFP_KERNEL
),
4222 #else /* CONFIG_NUMA */
4224 static void set_zonelist_order(void)
4226 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
4229 static void build_zonelists(pg_data_t
*pgdat
)
4231 int node
, local_node
;
4233 struct zonelist
*zonelist
;
4235 local_node
= pgdat
->node_id
;
4237 zonelist
= &pgdat
->node_zonelists
[0];
4238 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4241 * Now we build the zonelist so that it contains the zones
4242 * of all the other nodes.
4243 * We don't want to pressure a particular node, so when
4244 * building the zones for node N, we make sure that the
4245 * zones coming right after the local ones are those from
4246 * node N+1 (modulo N)
4248 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
4249 if (!node_online(node
))
4251 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4253 for (node
= 0; node
< local_node
; node
++) {
4254 if (!node_online(node
))
4256 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4259 zonelist
->_zonerefs
[j
].zone
= NULL
;
4260 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4263 #endif /* CONFIG_NUMA */
4266 * Boot pageset table. One per cpu which is going to be used for all
4267 * zones and all nodes. The parameters will be set in such a way
4268 * that an item put on a list will immediately be handed over to
4269 * the buddy list. This is safe since pageset manipulation is done
4270 * with interrupts disabled.
4272 * The boot_pagesets must be kept even after bootup is complete for
4273 * unused processors and/or zones. They do play a role for bootstrapping
4274 * hotplugged processors.
4276 * zoneinfo_show() and maybe other functions do
4277 * not check if the processor is online before following the pageset pointer.
4278 * Other parts of the kernel may not check if the zone is available.
4280 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
4281 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
4282 static void setup_zone_pageset(struct zone
*zone
);
4285 * Global mutex to protect against size modification of zonelists
4286 * as well as to serialize pageset setup for the new populated zone.
4288 DEFINE_MUTEX(zonelists_mutex
);
4290 /* return values int ....just for stop_machine() */
4291 static int __build_all_zonelists(void *data
)
4295 pg_data_t
*self
= data
;
4298 memset(node_load
, 0, sizeof(node_load
));
4301 if (self
&& !node_online(self
->node_id
)) {
4302 build_zonelists(self
);
4305 for_each_online_node(nid
) {
4306 pg_data_t
*pgdat
= NODE_DATA(nid
);
4308 build_zonelists(pgdat
);
4312 * Initialize the boot_pagesets that are going to be used
4313 * for bootstrapping processors. The real pagesets for
4314 * each zone will be allocated later when the per cpu
4315 * allocator is available.
4317 * boot_pagesets are used also for bootstrapping offline
4318 * cpus if the system is already booted because the pagesets
4319 * are needed to initialize allocators on a specific cpu too.
4320 * F.e. the percpu allocator needs the page allocator which
4321 * needs the percpu allocator in order to allocate its pagesets
4322 * (a chicken-egg dilemma).
4324 for_each_possible_cpu(cpu
) {
4325 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
4327 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4329 * We now know the "local memory node" for each node--
4330 * i.e., the node of the first zone in the generic zonelist.
4331 * Set up numa_mem percpu variable for on-line cpus. During
4332 * boot, only the boot cpu should be on-line; we'll init the
4333 * secondary cpus' numa_mem as they come on-line. During
4334 * node/memory hotplug, we'll fixup all on-line cpus.
4336 if (cpu_online(cpu
))
4337 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
4344 static noinline
void __init
4345 build_all_zonelists_init(void)
4347 __build_all_zonelists(NULL
);
4348 mminit_verify_zonelist();
4349 cpuset_init_current_mems_allowed();
4353 * Called with zonelists_mutex held always
4354 * unless system_state == SYSTEM_BOOTING.
4356 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4357 * [we're only called with non-NULL zone through __meminit paths] and
4358 * (2) call of __init annotated helper build_all_zonelists_init
4359 * [protected by SYSTEM_BOOTING].
4361 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
4363 set_zonelist_order();
4365 if (system_state
== SYSTEM_BOOTING
) {
4366 build_all_zonelists_init();
4368 #ifdef CONFIG_MEMORY_HOTPLUG
4370 setup_zone_pageset(zone
);
4372 /* we have to stop all cpus to guarantee there is no user
4374 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
4375 /* cpuset refresh routine should be here */
4377 vm_total_pages
= nr_free_pagecache_pages();
4379 * Disable grouping by mobility if the number of pages in the
4380 * system is too low to allow the mechanism to work. It would be
4381 * more accurate, but expensive to check per-zone. This check is
4382 * made on memory-hotadd so a system can start with mobility
4383 * disabled and enable it later
4385 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
4386 page_group_by_mobility_disabled
= 1;
4388 page_group_by_mobility_disabled
= 0;
4390 pr_info("Built %i zonelists in %s order, mobility grouping %s. "
4391 "Total pages: %ld\n",
4393 zonelist_order_name
[current_zonelist_order
],
4394 page_group_by_mobility_disabled
? "off" : "on",
4397 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
4402 * Helper functions to size the waitqueue hash table.
4403 * Essentially these want to choose hash table sizes sufficiently
4404 * large so that collisions trying to wait on pages are rare.
4405 * But in fact, the number of active page waitqueues on typical
4406 * systems is ridiculously low, less than 200. So this is even
4407 * conservative, even though it seems large.
4409 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
4410 * waitqueues, i.e. the size of the waitq table given the number of pages.
4412 #define PAGES_PER_WAITQUEUE 256
4414 #ifndef CONFIG_MEMORY_HOTPLUG
4415 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
4417 unsigned long size
= 1;
4419 pages
/= PAGES_PER_WAITQUEUE
;
4421 while (size
< pages
)
4425 * Once we have dozens or even hundreds of threads sleeping
4426 * on IO we've got bigger problems than wait queue collision.
4427 * Limit the size of the wait table to a reasonable size.
4429 size
= min(size
, 4096UL);
4431 return max(size
, 4UL);
4435 * A zone's size might be changed by hot-add, so it is not possible to determine
4436 * a suitable size for its wait_table. So we use the maximum size now.
4438 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
4440 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
4441 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
4442 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
4444 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
4445 * or more by the traditional way. (See above). It equals:
4447 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
4448 * ia64(16K page size) : = ( 8G + 4M)byte.
4449 * powerpc (64K page size) : = (32G +16M)byte.
4451 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
4458 * This is an integer logarithm so that shifts can be used later
4459 * to extract the more random high bits from the multiplicative
4460 * hash function before the remainder is taken.
4462 static inline unsigned long wait_table_bits(unsigned long size
)
4468 * Initially all pages are reserved - free ones are freed
4469 * up by free_all_bootmem() once the early boot process is
4470 * done. Non-atomic initialization, single-pass.
4472 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
4473 unsigned long start_pfn
, enum memmap_context context
)
4475 pg_data_t
*pgdat
= NODE_DATA(nid
);
4476 unsigned long end_pfn
= start_pfn
+ size
;
4479 unsigned long nr_initialised
= 0;
4481 if (highest_memmap_pfn
< end_pfn
- 1)
4482 highest_memmap_pfn
= end_pfn
- 1;
4484 z
= &pgdat
->node_zones
[zone
];
4485 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
4487 * There can be holes in boot-time mem_map[]s
4488 * handed to this function. They do not
4489 * exist on hotplugged memory.
4491 if (context
== MEMMAP_EARLY
) {
4492 if (!early_pfn_valid(pfn
))
4494 if (!early_pfn_in_nid(pfn
, nid
))
4496 if (!update_defer_init(pgdat
, pfn
, end_pfn
,
4502 * Mark the block movable so that blocks are reserved for
4503 * movable at startup. This will force kernel allocations
4504 * to reserve their blocks rather than leaking throughout
4505 * the address space during boot when many long-lived
4506 * kernel allocations are made.
4508 * bitmap is created for zone's valid pfn range. but memmap
4509 * can be created for invalid pages (for alignment)
4510 * check here not to call set_pageblock_migratetype() against
4513 if (!(pfn
& (pageblock_nr_pages
- 1))) {
4514 struct page
*page
= pfn_to_page(pfn
);
4516 __init_single_page(page
, pfn
, zone
, nid
);
4517 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4519 __init_single_pfn(pfn
, zone
, nid
);
4524 static void __meminit
zone_init_free_lists(struct zone
*zone
)
4526 unsigned int order
, t
;
4527 for_each_migratetype_order(order
, t
) {
4528 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
4529 zone
->free_area
[order
].nr_free
= 0;
4533 #ifndef __HAVE_ARCH_MEMMAP_INIT
4534 #define memmap_init(size, nid, zone, start_pfn) \
4535 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4538 static int zone_batchsize(struct zone
*zone
)
4544 * The per-cpu-pages pools are set to around 1000th of the
4545 * size of the zone. But no more than 1/2 of a meg.
4547 * OK, so we don't know how big the cache is. So guess.
4549 batch
= zone
->managed_pages
/ 1024;
4550 if (batch
* PAGE_SIZE
> 512 * 1024)
4551 batch
= (512 * 1024) / PAGE_SIZE
;
4552 batch
/= 4; /* We effectively *= 4 below */
4557 * Clamp the batch to a 2^n - 1 value. Having a power
4558 * of 2 value was found to be more likely to have
4559 * suboptimal cache aliasing properties in some cases.
4561 * For example if 2 tasks are alternately allocating
4562 * batches of pages, one task can end up with a lot
4563 * of pages of one half of the possible page colors
4564 * and the other with pages of the other colors.
4566 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
4571 /* The deferral and batching of frees should be suppressed under NOMMU
4574 * The problem is that NOMMU needs to be able to allocate large chunks
4575 * of contiguous memory as there's no hardware page translation to
4576 * assemble apparent contiguous memory from discontiguous pages.
4578 * Queueing large contiguous runs of pages for batching, however,
4579 * causes the pages to actually be freed in smaller chunks. As there
4580 * can be a significant delay between the individual batches being
4581 * recycled, this leads to the once large chunks of space being
4582 * fragmented and becoming unavailable for high-order allocations.
4589 * pcp->high and pcp->batch values are related and dependent on one another:
4590 * ->batch must never be higher then ->high.
4591 * The following function updates them in a safe manner without read side
4594 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4595 * those fields changing asynchronously (acording the the above rule).
4597 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4598 * outside of boot time (or some other assurance that no concurrent updaters
4601 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
4602 unsigned long batch
)
4604 /* start with a fail safe value for batch */
4608 /* Update high, then batch, in order */
4615 /* a companion to pageset_set_high() */
4616 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
4618 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
4621 static void pageset_init(struct per_cpu_pageset
*p
)
4623 struct per_cpu_pages
*pcp
;
4626 memset(p
, 0, sizeof(*p
));
4630 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
4631 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
4634 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
4637 pageset_set_batch(p
, batch
);
4641 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4642 * to the value high for the pageset p.
4644 static void pageset_set_high(struct per_cpu_pageset
*p
,
4647 unsigned long batch
= max(1UL, high
/ 4);
4648 if ((high
/ 4) > (PAGE_SHIFT
* 8))
4649 batch
= PAGE_SHIFT
* 8;
4651 pageset_update(&p
->pcp
, high
, batch
);
4654 static void pageset_set_high_and_batch(struct zone
*zone
,
4655 struct per_cpu_pageset
*pcp
)
4657 if (percpu_pagelist_fraction
)
4658 pageset_set_high(pcp
,
4659 (zone
->managed_pages
/
4660 percpu_pagelist_fraction
));
4662 pageset_set_batch(pcp
, zone_batchsize(zone
));
4665 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
4667 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
4670 pageset_set_high_and_batch(zone
, pcp
);
4673 static void __meminit
setup_zone_pageset(struct zone
*zone
)
4676 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
4677 for_each_possible_cpu(cpu
)
4678 zone_pageset_init(zone
, cpu
);
4682 * Allocate per cpu pagesets and initialize them.
4683 * Before this call only boot pagesets were available.
4685 void __init
setup_per_cpu_pageset(void)
4689 for_each_populated_zone(zone
)
4690 setup_zone_pageset(zone
);
4693 static noinline __init_refok
4694 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
4700 * The per-page waitqueue mechanism uses hashed waitqueues
4703 zone
->wait_table_hash_nr_entries
=
4704 wait_table_hash_nr_entries(zone_size_pages
);
4705 zone
->wait_table_bits
=
4706 wait_table_bits(zone
->wait_table_hash_nr_entries
);
4707 alloc_size
= zone
->wait_table_hash_nr_entries
4708 * sizeof(wait_queue_head_t
);
4710 if (!slab_is_available()) {
4711 zone
->wait_table
= (wait_queue_head_t
*)
4712 memblock_virt_alloc_node_nopanic(
4713 alloc_size
, zone
->zone_pgdat
->node_id
);
4716 * This case means that a zone whose size was 0 gets new memory
4717 * via memory hot-add.
4718 * But it may be the case that a new node was hot-added. In
4719 * this case vmalloc() will not be able to use this new node's
4720 * memory - this wait_table must be initialized to use this new
4721 * node itself as well.
4722 * To use this new node's memory, further consideration will be
4725 zone
->wait_table
= vmalloc(alloc_size
);
4727 if (!zone
->wait_table
)
4730 for (i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
4731 init_waitqueue_head(zone
->wait_table
+ i
);
4736 static __meminit
void zone_pcp_init(struct zone
*zone
)
4739 * per cpu subsystem is not up at this point. The following code
4740 * relies on the ability of the linker to provide the
4741 * offset of a (static) per cpu variable into the per cpu area.
4743 zone
->pageset
= &boot_pageset
;
4745 if (populated_zone(zone
))
4746 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
4747 zone
->name
, zone
->present_pages
,
4748 zone_batchsize(zone
));
4751 int __meminit
init_currently_empty_zone(struct zone
*zone
,
4752 unsigned long zone_start_pfn
,
4755 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
4757 ret
= zone_wait_table_init(zone
, size
);
4760 pgdat
->nr_zones
= zone_idx(zone
) + 1;
4762 zone
->zone_start_pfn
= zone_start_pfn
;
4764 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
4765 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4767 (unsigned long)zone_idx(zone
),
4768 zone_start_pfn
, (zone_start_pfn
+ size
));
4770 zone_init_free_lists(zone
);
4775 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4776 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4779 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4781 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
4782 struct mminit_pfnnid_cache
*state
)
4784 unsigned long start_pfn
, end_pfn
;
4787 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
4788 return state
->last_nid
;
4790 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
4792 state
->last_start
= start_pfn
;
4793 state
->last_end
= end_pfn
;
4794 state
->last_nid
= nid
;
4799 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4802 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
4803 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4804 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
4806 * If an architecture guarantees that all ranges registered contain no holes
4807 * and may be freed, this this function may be used instead of calling
4808 * memblock_free_early_nid() manually.
4810 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
4812 unsigned long start_pfn
, end_pfn
;
4815 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
4816 start_pfn
= min(start_pfn
, max_low_pfn
);
4817 end_pfn
= min(end_pfn
, max_low_pfn
);
4819 if (start_pfn
< end_pfn
)
4820 memblock_free_early_nid(PFN_PHYS(start_pfn
),
4821 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
4827 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4828 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4830 * If an architecture guarantees that all ranges registered contain no holes and may
4831 * be freed, this function may be used instead of calling memory_present() manually.
4833 void __init
sparse_memory_present_with_active_regions(int nid
)
4835 unsigned long start_pfn
, end_pfn
;
4838 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
4839 memory_present(this_nid
, start_pfn
, end_pfn
);
4843 * get_pfn_range_for_nid - Return the start and end page frames for a node
4844 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4845 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
4846 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
4848 * It returns the start and end page frame of a node based on information
4849 * provided by memblock_set_node(). If called for a node
4850 * with no available memory, a warning is printed and the start and end
4853 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
4854 unsigned long *start_pfn
, unsigned long *end_pfn
)
4856 unsigned long this_start_pfn
, this_end_pfn
;
4862 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
4863 *start_pfn
= min(*start_pfn
, this_start_pfn
);
4864 *end_pfn
= max(*end_pfn
, this_end_pfn
);
4867 if (*start_pfn
== -1UL)
4872 * This finds a zone that can be used for ZONE_MOVABLE pages. The
4873 * assumption is made that zones within a node are ordered in monotonic
4874 * increasing memory addresses so that the "highest" populated zone is used
4876 static void __init
find_usable_zone_for_movable(void)
4879 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
4880 if (zone_index
== ZONE_MOVABLE
)
4883 if (arch_zone_highest_possible_pfn
[zone_index
] >
4884 arch_zone_lowest_possible_pfn
[zone_index
])
4888 VM_BUG_ON(zone_index
== -1);
4889 movable_zone
= zone_index
;
4893 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4894 * because it is sized independent of architecture. Unlike the other zones,
4895 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4896 * in each node depending on the size of each node and how evenly kernelcore
4897 * is distributed. This helper function adjusts the zone ranges
4898 * provided by the architecture for a given node by using the end of the
4899 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4900 * zones within a node are in order of monotonic increases memory addresses
4902 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
4903 unsigned long zone_type
,
4904 unsigned long node_start_pfn
,
4905 unsigned long node_end_pfn
,
4906 unsigned long *zone_start_pfn
,
4907 unsigned long *zone_end_pfn
)
4909 /* Only adjust if ZONE_MOVABLE is on this node */
4910 if (zone_movable_pfn
[nid
]) {
4911 /* Size ZONE_MOVABLE */
4912 if (zone_type
== ZONE_MOVABLE
) {
4913 *zone_start_pfn
= zone_movable_pfn
[nid
];
4914 *zone_end_pfn
= min(node_end_pfn
,
4915 arch_zone_highest_possible_pfn
[movable_zone
]);
4917 /* Adjust for ZONE_MOVABLE starting within this range */
4918 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
4919 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
4920 *zone_end_pfn
= zone_movable_pfn
[nid
];
4922 /* Check if this whole range is within ZONE_MOVABLE */
4923 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
4924 *zone_start_pfn
= *zone_end_pfn
;
4929 * Return the number of pages a zone spans in a node, including holes
4930 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4932 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4933 unsigned long zone_type
,
4934 unsigned long node_start_pfn
,
4935 unsigned long node_end_pfn
,
4936 unsigned long *ignored
)
4938 unsigned long zone_start_pfn
, zone_end_pfn
;
4940 /* When hotadd a new node from cpu_up(), the node should be empty */
4941 if (!node_start_pfn
&& !node_end_pfn
)
4944 /* Get the start and end of the zone */
4945 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
4946 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
4947 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4948 node_start_pfn
, node_end_pfn
,
4949 &zone_start_pfn
, &zone_end_pfn
);
4951 /* Check that this node has pages within the zone's required range */
4952 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
4955 /* Move the zone boundaries inside the node if necessary */
4956 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
4957 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
4959 /* Return the spanned pages */
4960 return zone_end_pfn
- zone_start_pfn
;
4964 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4965 * then all holes in the requested range will be accounted for.
4967 unsigned long __meminit
__absent_pages_in_range(int nid
,
4968 unsigned long range_start_pfn
,
4969 unsigned long range_end_pfn
)
4971 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
4972 unsigned long start_pfn
, end_pfn
;
4975 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
4976 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
4977 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
4978 nr_absent
-= end_pfn
- start_pfn
;
4984 * absent_pages_in_range - Return number of page frames in holes within a range
4985 * @start_pfn: The start PFN to start searching for holes
4986 * @end_pfn: The end PFN to stop searching for holes
4988 * It returns the number of pages frames in memory holes within a range.
4990 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
4991 unsigned long end_pfn
)
4993 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
4996 /* Return the number of page frames in holes in a zone on a node */
4997 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4998 unsigned long zone_type
,
4999 unsigned long node_start_pfn
,
5000 unsigned long node_end_pfn
,
5001 unsigned long *ignored
)
5003 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
5004 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
5005 unsigned long zone_start_pfn
, zone_end_pfn
;
5007 /* When hotadd a new node from cpu_up(), the node should be empty */
5008 if (!node_start_pfn
&& !node_end_pfn
)
5011 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
5012 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
5014 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5015 node_start_pfn
, node_end_pfn
,
5016 &zone_start_pfn
, &zone_end_pfn
);
5017 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
5020 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5021 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5022 unsigned long zone_type
,
5023 unsigned long node_start_pfn
,
5024 unsigned long node_end_pfn
,
5025 unsigned long *zones_size
)
5027 return zones_size
[zone_type
];
5030 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5031 unsigned long zone_type
,
5032 unsigned long node_start_pfn
,
5033 unsigned long node_end_pfn
,
5034 unsigned long *zholes_size
)
5039 return zholes_size
[zone_type
];
5042 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5044 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
5045 unsigned long node_start_pfn
,
5046 unsigned long node_end_pfn
,
5047 unsigned long *zones_size
,
5048 unsigned long *zholes_size
)
5050 unsigned long realtotalpages
= 0, totalpages
= 0;
5053 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5054 struct zone
*zone
= pgdat
->node_zones
+ i
;
5055 unsigned long size
, real_size
;
5057 size
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
5061 real_size
= size
- zone_absent_pages_in_node(pgdat
->node_id
, i
,
5062 node_start_pfn
, node_end_pfn
,
5064 zone
->spanned_pages
= size
;
5065 zone
->present_pages
= real_size
;
5068 realtotalpages
+= real_size
;
5071 pgdat
->node_spanned_pages
= totalpages
;
5072 pgdat
->node_present_pages
= realtotalpages
;
5073 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
5077 #ifndef CONFIG_SPARSEMEM
5079 * Calculate the size of the zone->blockflags rounded to an unsigned long
5080 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5081 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5082 * round what is now in bits to nearest long in bits, then return it in
5085 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
5087 unsigned long usemapsize
;
5089 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
5090 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
5091 usemapsize
= usemapsize
>> pageblock_order
;
5092 usemapsize
*= NR_PAGEBLOCK_BITS
;
5093 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
5095 return usemapsize
/ 8;
5098 static void __init
setup_usemap(struct pglist_data
*pgdat
,
5100 unsigned long zone_start_pfn
,
5101 unsigned long zonesize
)
5103 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
5104 zone
->pageblock_flags
= NULL
;
5106 zone
->pageblock_flags
=
5107 memblock_virt_alloc_node_nopanic(usemapsize
,
5111 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
5112 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
5113 #endif /* CONFIG_SPARSEMEM */
5115 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5117 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5118 void __paginginit
set_pageblock_order(void)
5122 /* Check that pageblock_nr_pages has not already been setup */
5123 if (pageblock_order
)
5126 if (HPAGE_SHIFT
> PAGE_SHIFT
)
5127 order
= HUGETLB_PAGE_ORDER
;
5129 order
= MAX_ORDER
- 1;
5132 * Assume the largest contiguous order of interest is a huge page.
5133 * This value may be variable depending on boot parameters on IA64 and
5136 pageblock_order
= order
;
5138 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5141 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5142 * is unused as pageblock_order is set at compile-time. See
5143 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5146 void __paginginit
set_pageblock_order(void)
5150 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5152 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
5153 unsigned long present_pages
)
5155 unsigned long pages
= spanned_pages
;
5158 * Provide a more accurate estimation if there are holes within
5159 * the zone and SPARSEMEM is in use. If there are holes within the
5160 * zone, each populated memory region may cost us one or two extra
5161 * memmap pages due to alignment because memmap pages for each
5162 * populated regions may not naturally algined on page boundary.
5163 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5165 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
5166 IS_ENABLED(CONFIG_SPARSEMEM
))
5167 pages
= present_pages
;
5169 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
5173 * Set up the zone data structures:
5174 * - mark all pages reserved
5175 * - mark all memory queues empty
5176 * - clear the memory bitmaps
5178 * NOTE: pgdat should get zeroed by caller.
5180 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
)
5183 int nid
= pgdat
->node_id
;
5184 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
5187 pgdat_resize_init(pgdat
);
5188 #ifdef CONFIG_NUMA_BALANCING
5189 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
5190 pgdat
->numabalancing_migrate_nr_pages
= 0;
5191 pgdat
->numabalancing_migrate_next_window
= jiffies
;
5193 init_waitqueue_head(&pgdat
->kswapd_wait
);
5194 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
5195 pgdat_page_ext_init(pgdat
);
5197 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5198 struct zone
*zone
= pgdat
->node_zones
+ j
;
5199 unsigned long size
, realsize
, freesize
, memmap_pages
;
5201 size
= zone
->spanned_pages
;
5202 realsize
= freesize
= zone
->present_pages
;
5205 * Adjust freesize so that it accounts for how much memory
5206 * is used by this zone for memmap. This affects the watermark
5207 * and per-cpu initialisations
5209 memmap_pages
= calc_memmap_size(size
, realsize
);
5210 if (!is_highmem_idx(j
)) {
5211 if (freesize
>= memmap_pages
) {
5212 freesize
-= memmap_pages
;
5215 " %s zone: %lu pages used for memmap\n",
5216 zone_names
[j
], memmap_pages
);
5219 " %s zone: %lu pages exceeds freesize %lu\n",
5220 zone_names
[j
], memmap_pages
, freesize
);
5223 /* Account for reserved pages */
5224 if (j
== 0 && freesize
> dma_reserve
) {
5225 freesize
-= dma_reserve
;
5226 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
5227 zone_names
[0], dma_reserve
);
5230 if (!is_highmem_idx(j
))
5231 nr_kernel_pages
+= freesize
;
5232 /* Charge for highmem memmap if there are enough kernel pages */
5233 else if (nr_kernel_pages
> memmap_pages
* 2)
5234 nr_kernel_pages
-= memmap_pages
;
5235 nr_all_pages
+= freesize
;
5238 * Set an approximate value for lowmem here, it will be adjusted
5239 * when the bootmem allocator frees pages into the buddy system.
5240 * And all highmem pages will be managed by the buddy system.
5242 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
5245 zone
->min_unmapped_pages
= (freesize
*sysctl_min_unmapped_ratio
)
5247 zone
->min_slab_pages
= (freesize
* sysctl_min_slab_ratio
) / 100;
5249 zone
->name
= zone_names
[j
];
5250 spin_lock_init(&zone
->lock
);
5251 spin_lock_init(&zone
->lru_lock
);
5252 zone_seqlock_init(zone
);
5253 zone
->zone_pgdat
= pgdat
;
5254 zone_pcp_init(zone
);
5256 /* For bootup, initialized properly in watermark setup */
5257 mod_zone_page_state(zone
, NR_ALLOC_BATCH
, zone
->managed_pages
);
5259 lruvec_init(&zone
->lruvec
);
5263 set_pageblock_order();
5264 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
5265 ret
= init_currently_empty_zone(zone
, zone_start_pfn
, size
);
5267 memmap_init(size
, nid
, j
, zone_start_pfn
);
5268 zone_start_pfn
+= size
;
5272 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
5274 unsigned long __maybe_unused start
= 0;
5275 unsigned long __maybe_unused offset
= 0;
5277 /* Skip empty nodes */
5278 if (!pgdat
->node_spanned_pages
)
5281 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5282 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
5283 offset
= pgdat
->node_start_pfn
- start
;
5284 /* ia64 gets its own node_mem_map, before this, without bootmem */
5285 if (!pgdat
->node_mem_map
) {
5286 unsigned long size
, end
;
5290 * The zone's endpoints aren't required to be MAX_ORDER
5291 * aligned but the node_mem_map endpoints must be in order
5292 * for the buddy allocator to function correctly.
5294 end
= pgdat_end_pfn(pgdat
);
5295 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
5296 size
= (end
- start
) * sizeof(struct page
);
5297 map
= alloc_remap(pgdat
->node_id
, size
);
5299 map
= memblock_virt_alloc_node_nopanic(size
,
5301 pgdat
->node_mem_map
= map
+ offset
;
5303 #ifndef CONFIG_NEED_MULTIPLE_NODES
5305 * With no DISCONTIG, the global mem_map is just set as node 0's
5307 if (pgdat
== NODE_DATA(0)) {
5308 mem_map
= NODE_DATA(0)->node_mem_map
;
5309 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
5310 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
5312 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5315 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
5318 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
5319 unsigned long node_start_pfn
, unsigned long *zholes_size
)
5321 pg_data_t
*pgdat
= NODE_DATA(nid
);
5322 unsigned long start_pfn
= 0;
5323 unsigned long end_pfn
= 0;
5325 /* pg_data_t should be reset to zero when it's allocated */
5326 WARN_ON(pgdat
->nr_zones
|| pgdat
->classzone_idx
);
5328 reset_deferred_meminit(pgdat
);
5329 pgdat
->node_id
= nid
;
5330 pgdat
->node_start_pfn
= node_start_pfn
;
5331 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5332 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
5333 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
5334 (u64
)start_pfn
<< PAGE_SHIFT
,
5335 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
5337 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
5338 zones_size
, zholes_size
);
5340 alloc_node_mem_map(pgdat
);
5341 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5342 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
5343 nid
, (unsigned long)pgdat
,
5344 (unsigned long)pgdat
->node_mem_map
);
5347 free_area_init_core(pgdat
);
5350 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5352 #if MAX_NUMNODES > 1
5354 * Figure out the number of possible node ids.
5356 void __init
setup_nr_node_ids(void)
5358 unsigned int highest
;
5360 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
5361 nr_node_ids
= highest
+ 1;
5366 * node_map_pfn_alignment - determine the maximum internode alignment
5368 * This function should be called after node map is populated and sorted.
5369 * It calculates the maximum power of two alignment which can distinguish
5372 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5373 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5374 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5375 * shifted, 1GiB is enough and this function will indicate so.
5377 * This is used to test whether pfn -> nid mapping of the chosen memory
5378 * model has fine enough granularity to avoid incorrect mapping for the
5379 * populated node map.
5381 * Returns the determined alignment in pfn's. 0 if there is no alignment
5382 * requirement (single node).
5384 unsigned long __init
node_map_pfn_alignment(void)
5386 unsigned long accl_mask
= 0, last_end
= 0;
5387 unsigned long start
, end
, mask
;
5391 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
5392 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
5399 * Start with a mask granular enough to pin-point to the
5400 * start pfn and tick off bits one-by-one until it becomes
5401 * too coarse to separate the current node from the last.
5403 mask
= ~((1 << __ffs(start
)) - 1);
5404 while (mask
&& last_end
<= (start
& (mask
<< 1)))
5407 /* accumulate all internode masks */
5411 /* convert mask to number of pages */
5412 return ~accl_mask
+ 1;
5415 /* Find the lowest pfn for a node */
5416 static unsigned long __init
find_min_pfn_for_node(int nid
)
5418 unsigned long min_pfn
= ULONG_MAX
;
5419 unsigned long start_pfn
;
5422 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
5423 min_pfn
= min(min_pfn
, start_pfn
);
5425 if (min_pfn
== ULONG_MAX
) {
5427 "Could not find start_pfn for node %d\n", nid
);
5435 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5437 * It returns the minimum PFN based on information provided via
5438 * memblock_set_node().
5440 unsigned long __init
find_min_pfn_with_active_regions(void)
5442 return find_min_pfn_for_node(MAX_NUMNODES
);
5446 * early_calculate_totalpages()
5447 * Sum pages in active regions for movable zone.
5448 * Populate N_MEMORY for calculating usable_nodes.
5450 static unsigned long __init
early_calculate_totalpages(void)
5452 unsigned long totalpages
= 0;
5453 unsigned long start_pfn
, end_pfn
;
5456 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
5457 unsigned long pages
= end_pfn
- start_pfn
;
5459 totalpages
+= pages
;
5461 node_set_state(nid
, N_MEMORY
);
5467 * Find the PFN the Movable zone begins in each node. Kernel memory
5468 * is spread evenly between nodes as long as the nodes have enough
5469 * memory. When they don't, some nodes will have more kernelcore than
5472 static void __init
find_zone_movable_pfns_for_nodes(void)
5475 unsigned long usable_startpfn
;
5476 unsigned long kernelcore_node
, kernelcore_remaining
;
5477 /* save the state before borrow the nodemask */
5478 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
5479 unsigned long totalpages
= early_calculate_totalpages();
5480 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
5481 struct memblock_region
*r
;
5483 /* Need to find movable_zone earlier when movable_node is specified. */
5484 find_usable_zone_for_movable();
5487 * If movable_node is specified, ignore kernelcore and movablecore
5490 if (movable_node_is_enabled()) {
5491 for_each_memblock(memory
, r
) {
5492 if (!memblock_is_hotpluggable(r
))
5497 usable_startpfn
= PFN_DOWN(r
->base
);
5498 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
5499 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
5507 * If movablecore=nn[KMG] was specified, calculate what size of
5508 * kernelcore that corresponds so that memory usable for
5509 * any allocation type is evenly spread. If both kernelcore
5510 * and movablecore are specified, then the value of kernelcore
5511 * will be used for required_kernelcore if it's greater than
5512 * what movablecore would have allowed.
5514 if (required_movablecore
) {
5515 unsigned long corepages
;
5518 * Round-up so that ZONE_MOVABLE is at least as large as what
5519 * was requested by the user
5521 required_movablecore
=
5522 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
5523 required_movablecore
= min(totalpages
, required_movablecore
);
5524 corepages
= totalpages
- required_movablecore
;
5526 required_kernelcore
= max(required_kernelcore
, corepages
);
5530 * If kernelcore was not specified or kernelcore size is larger
5531 * than totalpages, there is no ZONE_MOVABLE.
5533 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
5536 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5537 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
5540 /* Spread kernelcore memory as evenly as possible throughout nodes */
5541 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5542 for_each_node_state(nid
, N_MEMORY
) {
5543 unsigned long start_pfn
, end_pfn
;
5546 * Recalculate kernelcore_node if the division per node
5547 * now exceeds what is necessary to satisfy the requested
5548 * amount of memory for the kernel
5550 if (required_kernelcore
< kernelcore_node
)
5551 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5554 * As the map is walked, we track how much memory is usable
5555 * by the kernel using kernelcore_remaining. When it is
5556 * 0, the rest of the node is usable by ZONE_MOVABLE
5558 kernelcore_remaining
= kernelcore_node
;
5560 /* Go through each range of PFNs within this node */
5561 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5562 unsigned long size_pages
;
5564 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
5565 if (start_pfn
>= end_pfn
)
5568 /* Account for what is only usable for kernelcore */
5569 if (start_pfn
< usable_startpfn
) {
5570 unsigned long kernel_pages
;
5571 kernel_pages
= min(end_pfn
, usable_startpfn
)
5574 kernelcore_remaining
-= min(kernel_pages
,
5575 kernelcore_remaining
);
5576 required_kernelcore
-= min(kernel_pages
,
5577 required_kernelcore
);
5579 /* Continue if range is now fully accounted */
5580 if (end_pfn
<= usable_startpfn
) {
5583 * Push zone_movable_pfn to the end so
5584 * that if we have to rebalance
5585 * kernelcore across nodes, we will
5586 * not double account here
5588 zone_movable_pfn
[nid
] = end_pfn
;
5591 start_pfn
= usable_startpfn
;
5595 * The usable PFN range for ZONE_MOVABLE is from
5596 * start_pfn->end_pfn. Calculate size_pages as the
5597 * number of pages used as kernelcore
5599 size_pages
= end_pfn
- start_pfn
;
5600 if (size_pages
> kernelcore_remaining
)
5601 size_pages
= kernelcore_remaining
;
5602 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
5605 * Some kernelcore has been met, update counts and
5606 * break if the kernelcore for this node has been
5609 required_kernelcore
-= min(required_kernelcore
,
5611 kernelcore_remaining
-= size_pages
;
5612 if (!kernelcore_remaining
)
5618 * If there is still required_kernelcore, we do another pass with one
5619 * less node in the count. This will push zone_movable_pfn[nid] further
5620 * along on the nodes that still have memory until kernelcore is
5624 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
5628 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5629 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
5630 zone_movable_pfn
[nid
] =
5631 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
5634 /* restore the node_state */
5635 node_states
[N_MEMORY
] = saved_node_state
;
5638 /* Any regular or high memory on that node ? */
5639 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
5641 enum zone_type zone_type
;
5643 if (N_MEMORY
== N_NORMAL_MEMORY
)
5646 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
5647 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
5648 if (populated_zone(zone
)) {
5649 node_set_state(nid
, N_HIGH_MEMORY
);
5650 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
5651 zone_type
<= ZONE_NORMAL
)
5652 node_set_state(nid
, N_NORMAL_MEMORY
);
5659 * free_area_init_nodes - Initialise all pg_data_t and zone data
5660 * @max_zone_pfn: an array of max PFNs for each zone
5662 * This will call free_area_init_node() for each active node in the system.
5663 * Using the page ranges provided by memblock_set_node(), the size of each
5664 * zone in each node and their holes is calculated. If the maximum PFN
5665 * between two adjacent zones match, it is assumed that the zone is empty.
5666 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5667 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5668 * starts where the previous one ended. For example, ZONE_DMA32 starts
5669 * at arch_max_dma_pfn.
5671 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
5673 unsigned long start_pfn
, end_pfn
;
5676 /* Record where the zone boundaries are */
5677 memset(arch_zone_lowest_possible_pfn
, 0,
5678 sizeof(arch_zone_lowest_possible_pfn
));
5679 memset(arch_zone_highest_possible_pfn
, 0,
5680 sizeof(arch_zone_highest_possible_pfn
));
5681 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
5682 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
5683 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
5684 if (i
== ZONE_MOVABLE
)
5686 arch_zone_lowest_possible_pfn
[i
] =
5687 arch_zone_highest_possible_pfn
[i
-1];
5688 arch_zone_highest_possible_pfn
[i
] =
5689 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
5691 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
5692 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
5694 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
5695 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
5696 find_zone_movable_pfns_for_nodes();
5698 /* Print out the zone ranges */
5699 pr_info("Zone ranges:\n");
5700 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5701 if (i
== ZONE_MOVABLE
)
5703 pr_info(" %-8s ", zone_names
[i
]);
5704 if (arch_zone_lowest_possible_pfn
[i
] ==
5705 arch_zone_highest_possible_pfn
[i
])
5708 pr_cont("[mem %#018Lx-%#018Lx]\n",
5709 (u64
)arch_zone_lowest_possible_pfn
[i
]
5711 ((u64
)arch_zone_highest_possible_pfn
[i
]
5712 << PAGE_SHIFT
) - 1);
5715 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5716 pr_info("Movable zone start for each node\n");
5717 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
5718 if (zone_movable_pfn
[i
])
5719 pr_info(" Node %d: %#018Lx\n", i
,
5720 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
5723 /* Print out the early node map */
5724 pr_info("Early memory node ranges\n");
5725 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
5726 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
5727 (u64
)start_pfn
<< PAGE_SHIFT
,
5728 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
5730 /* Initialise every node */
5731 mminit_verify_pageflags_layout();
5732 setup_nr_node_ids();
5733 for_each_online_node(nid
) {
5734 pg_data_t
*pgdat
= NODE_DATA(nid
);
5735 free_area_init_node(nid
, NULL
,
5736 find_min_pfn_for_node(nid
), NULL
);
5738 /* Any memory on that node */
5739 if (pgdat
->node_present_pages
)
5740 node_set_state(nid
, N_MEMORY
);
5741 check_for_memory(pgdat
, nid
);
5745 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
5747 unsigned long long coremem
;
5751 coremem
= memparse(p
, &p
);
5752 *core
= coremem
>> PAGE_SHIFT
;
5754 /* Paranoid check that UL is enough for the coremem value */
5755 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
5761 * kernelcore=size sets the amount of memory for use for allocations that
5762 * cannot be reclaimed or migrated.
5764 static int __init
cmdline_parse_kernelcore(char *p
)
5766 return cmdline_parse_core(p
, &required_kernelcore
);
5770 * movablecore=size sets the amount of memory for use for allocations that
5771 * can be reclaimed or migrated.
5773 static int __init
cmdline_parse_movablecore(char *p
)
5775 return cmdline_parse_core(p
, &required_movablecore
);
5778 early_param("kernelcore", cmdline_parse_kernelcore
);
5779 early_param("movablecore", cmdline_parse_movablecore
);
5781 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5783 void adjust_managed_page_count(struct page
*page
, long count
)
5785 spin_lock(&managed_page_count_lock
);
5786 page_zone(page
)->managed_pages
+= count
;
5787 totalram_pages
+= count
;
5788 #ifdef CONFIG_HIGHMEM
5789 if (PageHighMem(page
))
5790 totalhigh_pages
+= count
;
5792 spin_unlock(&managed_page_count_lock
);
5794 EXPORT_SYMBOL(adjust_managed_page_count
);
5796 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
5799 unsigned long pages
= 0;
5801 start
= (void *)PAGE_ALIGN((unsigned long)start
);
5802 end
= (void *)((unsigned long)end
& PAGE_MASK
);
5803 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
5804 if ((unsigned int)poison
<= 0xFF)
5805 memset(pos
, poison
, PAGE_SIZE
);
5806 free_reserved_page(virt_to_page(pos
));
5810 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
5811 s
, pages
<< (PAGE_SHIFT
- 10), start
, end
);
5815 EXPORT_SYMBOL(free_reserved_area
);
5817 #ifdef CONFIG_HIGHMEM
5818 void free_highmem_page(struct page
*page
)
5820 __free_reserved_page(page
);
5822 page_zone(page
)->managed_pages
++;
5828 void __init
mem_init_print_info(const char *str
)
5830 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
5831 unsigned long init_code_size
, init_data_size
;
5833 physpages
= get_num_physpages();
5834 codesize
= _etext
- _stext
;
5835 datasize
= _edata
- _sdata
;
5836 rosize
= __end_rodata
- __start_rodata
;
5837 bss_size
= __bss_stop
- __bss_start
;
5838 init_data_size
= __init_end
- __init_begin
;
5839 init_code_size
= _einittext
- _sinittext
;
5842 * Detect special cases and adjust section sizes accordingly:
5843 * 1) .init.* may be embedded into .data sections
5844 * 2) .init.text.* may be out of [__init_begin, __init_end],
5845 * please refer to arch/tile/kernel/vmlinux.lds.S.
5846 * 3) .rodata.* may be embedded into .text or .data sections.
5848 #define adj_init_size(start, end, size, pos, adj) \
5850 if (start <= pos && pos < end && size > adj) \
5854 adj_init_size(__init_begin
, __init_end
, init_data_size
,
5855 _sinittext
, init_code_size
);
5856 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
5857 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
5858 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
5859 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
5861 #undef adj_init_size
5863 pr_info("Memory: %luK/%luK available "
5864 "(%luK kernel code, %luK rwdata, %luK rodata, "
5865 "%luK init, %luK bss, %luK reserved, %luK cma-reserved"
5866 #ifdef CONFIG_HIGHMEM
5870 nr_free_pages() << (PAGE_SHIFT
-10), physpages
<< (PAGE_SHIFT
-10),
5871 codesize
>> 10, datasize
>> 10, rosize
>> 10,
5872 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
5873 (physpages
- totalram_pages
- totalcma_pages
) << (PAGE_SHIFT
-10),
5874 totalcma_pages
<< (PAGE_SHIFT
-10),
5875 #ifdef CONFIG_HIGHMEM
5876 totalhigh_pages
<< (PAGE_SHIFT
-10),
5878 str
? ", " : "", str
? str
: "");
5882 * set_dma_reserve - set the specified number of pages reserved in the first zone
5883 * @new_dma_reserve: The number of pages to mark reserved
5885 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
5886 * In the DMA zone, a significant percentage may be consumed by kernel image
5887 * and other unfreeable allocations which can skew the watermarks badly. This
5888 * function may optionally be used to account for unfreeable pages in the
5889 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
5890 * smaller per-cpu batchsize.
5892 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
5894 dma_reserve
= new_dma_reserve
;
5897 void __init
free_area_init(unsigned long *zones_size
)
5899 free_area_init_node(0, zones_size
,
5900 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
5903 static int page_alloc_cpu_notify(struct notifier_block
*self
,
5904 unsigned long action
, void *hcpu
)
5906 int cpu
= (unsigned long)hcpu
;
5908 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
5909 lru_add_drain_cpu(cpu
);
5913 * Spill the event counters of the dead processor
5914 * into the current processors event counters.
5915 * This artificially elevates the count of the current
5918 vm_events_fold_cpu(cpu
);
5921 * Zero the differential counters of the dead processor
5922 * so that the vm statistics are consistent.
5924 * This is only okay since the processor is dead and cannot
5925 * race with what we are doing.
5927 cpu_vm_stats_fold(cpu
);
5932 void __init
page_alloc_init(void)
5934 hotcpu_notifier(page_alloc_cpu_notify
, 0);
5938 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
5939 * or min_free_kbytes changes.
5941 static void calculate_totalreserve_pages(void)
5943 struct pglist_data
*pgdat
;
5944 unsigned long reserve_pages
= 0;
5945 enum zone_type i
, j
;
5947 for_each_online_pgdat(pgdat
) {
5948 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5949 struct zone
*zone
= pgdat
->node_zones
+ i
;
5952 /* Find valid and maximum lowmem_reserve in the zone */
5953 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
5954 if (zone
->lowmem_reserve
[j
] > max
)
5955 max
= zone
->lowmem_reserve
[j
];
5958 /* we treat the high watermark as reserved pages. */
5959 max
+= high_wmark_pages(zone
);
5961 if (max
> zone
->managed_pages
)
5962 max
= zone
->managed_pages
;
5964 zone
->totalreserve_pages
= max
;
5966 reserve_pages
+= max
;
5969 totalreserve_pages
= reserve_pages
;
5973 * setup_per_zone_lowmem_reserve - called whenever
5974 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
5975 * has a correct pages reserved value, so an adequate number of
5976 * pages are left in the zone after a successful __alloc_pages().
5978 static void setup_per_zone_lowmem_reserve(void)
5980 struct pglist_data
*pgdat
;
5981 enum zone_type j
, idx
;
5983 for_each_online_pgdat(pgdat
) {
5984 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5985 struct zone
*zone
= pgdat
->node_zones
+ j
;
5986 unsigned long managed_pages
= zone
->managed_pages
;
5988 zone
->lowmem_reserve
[j
] = 0;
5992 struct zone
*lower_zone
;
5996 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
5997 sysctl_lowmem_reserve_ratio
[idx
] = 1;
5999 lower_zone
= pgdat
->node_zones
+ idx
;
6000 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
6001 sysctl_lowmem_reserve_ratio
[idx
];
6002 managed_pages
+= lower_zone
->managed_pages
;
6007 /* update totalreserve_pages */
6008 calculate_totalreserve_pages();
6011 static void __setup_per_zone_wmarks(void)
6013 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
6014 unsigned long lowmem_pages
= 0;
6016 unsigned long flags
;
6018 /* Calculate total number of !ZONE_HIGHMEM pages */
6019 for_each_zone(zone
) {
6020 if (!is_highmem(zone
))
6021 lowmem_pages
+= zone
->managed_pages
;
6024 for_each_zone(zone
) {
6027 spin_lock_irqsave(&zone
->lock
, flags
);
6028 tmp
= (u64
)pages_min
* zone
->managed_pages
;
6029 do_div(tmp
, lowmem_pages
);
6030 if (is_highmem(zone
)) {
6032 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6033 * need highmem pages, so cap pages_min to a small
6036 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6037 * deltas control asynch page reclaim, and so should
6038 * not be capped for highmem.
6040 unsigned long min_pages
;
6042 min_pages
= zone
->managed_pages
/ 1024;
6043 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
6044 zone
->watermark
[WMARK_MIN
] = min_pages
;
6047 * If it's a lowmem zone, reserve a number of pages
6048 * proportionate to the zone's size.
6050 zone
->watermark
[WMARK_MIN
] = tmp
;
6053 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + (tmp
>> 2);
6054 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + (tmp
>> 1);
6056 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
6057 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
6058 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
6060 spin_unlock_irqrestore(&zone
->lock
, flags
);
6063 /* update totalreserve_pages */
6064 calculate_totalreserve_pages();
6068 * setup_per_zone_wmarks - called when min_free_kbytes changes
6069 * or when memory is hot-{added|removed}
6071 * Ensures that the watermark[min,low,high] values for each zone are set
6072 * correctly with respect to min_free_kbytes.
6074 void setup_per_zone_wmarks(void)
6076 mutex_lock(&zonelists_mutex
);
6077 __setup_per_zone_wmarks();
6078 mutex_unlock(&zonelists_mutex
);
6082 * The inactive anon list should be small enough that the VM never has to
6083 * do too much work, but large enough that each inactive page has a chance
6084 * to be referenced again before it is swapped out.
6086 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
6087 * INACTIVE_ANON pages on this zone's LRU, maintained by the
6088 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
6089 * the anonymous pages are kept on the inactive list.
6092 * memory ratio inactive anon
6093 * -------------------------------------
6102 static void __meminit
calculate_zone_inactive_ratio(struct zone
*zone
)
6104 unsigned int gb
, ratio
;
6106 /* Zone size in gigabytes */
6107 gb
= zone
->managed_pages
>> (30 - PAGE_SHIFT
);
6109 ratio
= int_sqrt(10 * gb
);
6113 zone
->inactive_ratio
= ratio
;
6116 static void __meminit
setup_per_zone_inactive_ratio(void)
6121 calculate_zone_inactive_ratio(zone
);
6125 * Initialise min_free_kbytes.
6127 * For small machines we want it small (128k min). For large machines
6128 * we want it large (64MB max). But it is not linear, because network
6129 * bandwidth does not increase linearly with machine size. We use
6131 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6132 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6148 int __meminit
init_per_zone_wmark_min(void)
6150 unsigned long lowmem_kbytes
;
6151 int new_min_free_kbytes
;
6153 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
6154 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
6156 if (new_min_free_kbytes
> user_min_free_kbytes
) {
6157 min_free_kbytes
= new_min_free_kbytes
;
6158 if (min_free_kbytes
< 128)
6159 min_free_kbytes
= 128;
6160 if (min_free_kbytes
> 65536)
6161 min_free_kbytes
= 65536;
6163 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6164 new_min_free_kbytes
, user_min_free_kbytes
);
6166 setup_per_zone_wmarks();
6167 refresh_zone_stat_thresholds();
6168 setup_per_zone_lowmem_reserve();
6169 setup_per_zone_inactive_ratio();
6172 module_init(init_per_zone_wmark_min
)
6175 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6176 * that we can call two helper functions whenever min_free_kbytes
6179 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
6180 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6184 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6189 user_min_free_kbytes
= min_free_kbytes
;
6190 setup_per_zone_wmarks();
6196 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6197 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6202 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6207 zone
->min_unmapped_pages
= (zone
->managed_pages
*
6208 sysctl_min_unmapped_ratio
) / 100;
6212 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6213 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6218 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6223 zone
->min_slab_pages
= (zone
->managed_pages
*
6224 sysctl_min_slab_ratio
) / 100;
6230 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6231 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6232 * whenever sysctl_lowmem_reserve_ratio changes.
6234 * The reserve ratio obviously has absolutely no relation with the
6235 * minimum watermarks. The lowmem reserve ratio can only make sense
6236 * if in function of the boot time zone sizes.
6238 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6239 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6241 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6242 setup_per_zone_lowmem_reserve();
6247 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6248 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6249 * pagelist can have before it gets flushed back to buddy allocator.
6251 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
6252 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6255 int old_percpu_pagelist_fraction
;
6258 mutex_lock(&pcp_batch_high_lock
);
6259 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
6261 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6262 if (!write
|| ret
< 0)
6265 /* Sanity checking to avoid pcp imbalance */
6266 if (percpu_pagelist_fraction
&&
6267 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
6268 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
6274 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
6277 for_each_populated_zone(zone
) {
6280 for_each_possible_cpu(cpu
)
6281 pageset_set_high_and_batch(zone
,
6282 per_cpu_ptr(zone
->pageset
, cpu
));
6285 mutex_unlock(&pcp_batch_high_lock
);
6290 int hashdist
= HASHDIST_DEFAULT
;
6292 static int __init
set_hashdist(char *str
)
6296 hashdist
= simple_strtoul(str
, &str
, 0);
6299 __setup("hashdist=", set_hashdist
);
6303 * allocate a large system hash table from bootmem
6304 * - it is assumed that the hash table must contain an exact power-of-2
6305 * quantity of entries
6306 * - limit is the number of hash buckets, not the total allocation size
6308 void *__init
alloc_large_system_hash(const char *tablename
,
6309 unsigned long bucketsize
,
6310 unsigned long numentries
,
6313 unsigned int *_hash_shift
,
6314 unsigned int *_hash_mask
,
6315 unsigned long low_limit
,
6316 unsigned long high_limit
)
6318 unsigned long long max
= high_limit
;
6319 unsigned long log2qty
, size
;
6322 /* allow the kernel cmdline to have a say */
6324 /* round applicable memory size up to nearest megabyte */
6325 numentries
= nr_kernel_pages
;
6327 /* It isn't necessary when PAGE_SIZE >= 1MB */
6328 if (PAGE_SHIFT
< 20)
6329 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
6331 /* limit to 1 bucket per 2^scale bytes of low memory */
6332 if (scale
> PAGE_SHIFT
)
6333 numentries
>>= (scale
- PAGE_SHIFT
);
6335 numentries
<<= (PAGE_SHIFT
- scale
);
6337 /* Make sure we've got at least a 0-order allocation.. */
6338 if (unlikely(flags
& HASH_SMALL
)) {
6339 /* Makes no sense without HASH_EARLY */
6340 WARN_ON(!(flags
& HASH_EARLY
));
6341 if (!(numentries
>> *_hash_shift
)) {
6342 numentries
= 1UL << *_hash_shift
;
6343 BUG_ON(!numentries
);
6345 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
6346 numentries
= PAGE_SIZE
/ bucketsize
;
6348 numentries
= roundup_pow_of_two(numentries
);
6350 /* limit allocation size to 1/16 total memory by default */
6352 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
6353 do_div(max
, bucketsize
);
6355 max
= min(max
, 0x80000000ULL
);
6357 if (numentries
< low_limit
)
6358 numentries
= low_limit
;
6359 if (numentries
> max
)
6362 log2qty
= ilog2(numentries
);
6365 size
= bucketsize
<< log2qty
;
6366 if (flags
& HASH_EARLY
)
6367 table
= memblock_virt_alloc_nopanic(size
, 0);
6369 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
6372 * If bucketsize is not a power-of-two, we may free
6373 * some pages at the end of hash table which
6374 * alloc_pages_exact() automatically does
6376 if (get_order(size
) < MAX_ORDER
) {
6377 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
6378 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
6381 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
6384 panic("Failed to allocate %s hash table\n", tablename
);
6386 printk(KERN_INFO
"%s hash table entries: %ld (order: %d, %lu bytes)\n",
6389 ilog2(size
) - PAGE_SHIFT
,
6393 *_hash_shift
= log2qty
;
6395 *_hash_mask
= (1 << log2qty
) - 1;
6400 /* Return a pointer to the bitmap storing bits affecting a block of pages */
6401 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
6404 #ifdef CONFIG_SPARSEMEM
6405 return __pfn_to_section(pfn
)->pageblock_flags
;
6407 return zone
->pageblock_flags
;
6408 #endif /* CONFIG_SPARSEMEM */
6411 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
6413 #ifdef CONFIG_SPARSEMEM
6414 pfn
&= (PAGES_PER_SECTION
-1);
6415 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6417 pfn
= pfn
- round_down(zone
->zone_start_pfn
, pageblock_nr_pages
);
6418 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6419 #endif /* CONFIG_SPARSEMEM */
6423 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
6424 * @page: The page within the block of interest
6425 * @pfn: The target page frame number
6426 * @end_bitidx: The last bit of interest to retrieve
6427 * @mask: mask of bits that the caller is interested in
6429 * Return: pageblock_bits flags
6431 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
6432 unsigned long end_bitidx
,
6436 unsigned long *bitmap
;
6437 unsigned long bitidx
, word_bitidx
;
6440 zone
= page_zone(page
);
6441 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6442 bitidx
= pfn_to_bitidx(zone
, pfn
);
6443 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6444 bitidx
&= (BITS_PER_LONG
-1);
6446 word
= bitmap
[word_bitidx
];
6447 bitidx
+= end_bitidx
;
6448 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
6452 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
6453 * @page: The page within the block of interest
6454 * @flags: The flags to set
6455 * @pfn: The target page frame number
6456 * @end_bitidx: The last bit of interest
6457 * @mask: mask of bits that the caller is interested in
6459 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
6461 unsigned long end_bitidx
,
6465 unsigned long *bitmap
;
6466 unsigned long bitidx
, word_bitidx
;
6467 unsigned long old_word
, word
;
6469 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
6471 zone
= page_zone(page
);
6472 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6473 bitidx
= pfn_to_bitidx(zone
, pfn
);
6474 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6475 bitidx
&= (BITS_PER_LONG
-1);
6477 VM_BUG_ON_PAGE(!zone_spans_pfn(zone
, pfn
), page
);
6479 bitidx
+= end_bitidx
;
6480 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
6481 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
6483 word
= READ_ONCE(bitmap
[word_bitidx
]);
6485 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
6486 if (word
== old_word
)
6493 * This function checks whether pageblock includes unmovable pages or not.
6494 * If @count is not zero, it is okay to include less @count unmovable pages
6496 * PageLRU check without isolation or lru_lock could race so that
6497 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6498 * expect this function should be exact.
6500 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
6501 bool skip_hwpoisoned_pages
)
6503 unsigned long pfn
, iter
, found
;
6507 * For avoiding noise data, lru_add_drain_all() should be called
6508 * If ZONE_MOVABLE, the zone never contains unmovable pages
6510 if (zone_idx(zone
) == ZONE_MOVABLE
)
6512 mt
= get_pageblock_migratetype(page
);
6513 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
6516 pfn
= page_to_pfn(page
);
6517 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
6518 unsigned long check
= pfn
+ iter
;
6520 if (!pfn_valid_within(check
))
6523 page
= pfn_to_page(check
);
6526 * Hugepages are not in LRU lists, but they're movable.
6527 * We need not scan over tail pages bacause we don't
6528 * handle each tail page individually in migration.
6530 if (PageHuge(page
)) {
6531 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
6536 * We can't use page_count without pin a page
6537 * because another CPU can free compound page.
6538 * This check already skips compound tails of THP
6539 * because their page->_count is zero at all time.
6541 if (!atomic_read(&page
->_count
)) {
6542 if (PageBuddy(page
))
6543 iter
+= (1 << page_order(page
)) - 1;
6548 * The HWPoisoned page may be not in buddy system, and
6549 * page_count() is not 0.
6551 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
6557 * If there are RECLAIMABLE pages, we need to check
6558 * it. But now, memory offline itself doesn't call
6559 * shrink_node_slabs() and it still to be fixed.
6562 * If the page is not RAM, page_count()should be 0.
6563 * we don't need more check. This is an _used_ not-movable page.
6565 * The problematic thing here is PG_reserved pages. PG_reserved
6566 * is set to both of a memory hole page and a _used_ kernel
6575 bool is_pageblock_removable_nolock(struct page
*page
)
6581 * We have to be careful here because we are iterating over memory
6582 * sections which are not zone aware so we might end up outside of
6583 * the zone but still within the section.
6584 * We have to take care about the node as well. If the node is offline
6585 * its NODE_DATA will be NULL - see page_zone.
6587 if (!node_online(page_to_nid(page
)))
6590 zone
= page_zone(page
);
6591 pfn
= page_to_pfn(page
);
6592 if (!zone_spans_pfn(zone
, pfn
))
6595 return !has_unmovable_pages(zone
, page
, 0, true);
6600 static unsigned long pfn_max_align_down(unsigned long pfn
)
6602 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6603 pageblock_nr_pages
) - 1);
6606 static unsigned long pfn_max_align_up(unsigned long pfn
)
6608 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6609 pageblock_nr_pages
));
6612 /* [start, end) must belong to a single zone. */
6613 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
6614 unsigned long start
, unsigned long end
)
6616 /* This function is based on compact_zone() from compaction.c. */
6617 unsigned long nr_reclaimed
;
6618 unsigned long pfn
= start
;
6619 unsigned int tries
= 0;
6624 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
6625 if (fatal_signal_pending(current
)) {
6630 if (list_empty(&cc
->migratepages
)) {
6631 cc
->nr_migratepages
= 0;
6632 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
6638 } else if (++tries
== 5) {
6639 ret
= ret
< 0 ? ret
: -EBUSY
;
6643 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
6645 cc
->nr_migratepages
-= nr_reclaimed
;
6647 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
6648 NULL
, 0, cc
->mode
, MR_CMA
);
6651 putback_movable_pages(&cc
->migratepages
);
6658 * alloc_contig_range() -- tries to allocate given range of pages
6659 * @start: start PFN to allocate
6660 * @end: one-past-the-last PFN to allocate
6661 * @migratetype: migratetype of the underlaying pageblocks (either
6662 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
6663 * in range must have the same migratetype and it must
6664 * be either of the two.
6666 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
6667 * aligned, however it's the caller's responsibility to guarantee that
6668 * we are the only thread that changes migrate type of pageblocks the
6671 * The PFN range must belong to a single zone.
6673 * Returns zero on success or negative error code. On success all
6674 * pages which PFN is in [start, end) are allocated for the caller and
6675 * need to be freed with free_contig_range().
6677 int alloc_contig_range(unsigned long start
, unsigned long end
,
6678 unsigned migratetype
)
6680 unsigned long outer_start
, outer_end
;
6684 struct compact_control cc
= {
6685 .nr_migratepages
= 0,
6687 .zone
= page_zone(pfn_to_page(start
)),
6688 .mode
= MIGRATE_SYNC
,
6689 .ignore_skip_hint
= true,
6691 INIT_LIST_HEAD(&cc
.migratepages
);
6694 * What we do here is we mark all pageblocks in range as
6695 * MIGRATE_ISOLATE. Because pageblock and max order pages may
6696 * have different sizes, and due to the way page allocator
6697 * work, we align the range to biggest of the two pages so
6698 * that page allocator won't try to merge buddies from
6699 * different pageblocks and change MIGRATE_ISOLATE to some
6700 * other migration type.
6702 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
6703 * migrate the pages from an unaligned range (ie. pages that
6704 * we are interested in). This will put all the pages in
6705 * range back to page allocator as MIGRATE_ISOLATE.
6707 * When this is done, we take the pages in range from page
6708 * allocator removing them from the buddy system. This way
6709 * page allocator will never consider using them.
6711 * This lets us mark the pageblocks back as
6712 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
6713 * aligned range but not in the unaligned, original range are
6714 * put back to page allocator so that buddy can use them.
6717 ret
= start_isolate_page_range(pfn_max_align_down(start
),
6718 pfn_max_align_up(end
), migratetype
,
6724 * In case of -EBUSY, we'd like to know which page causes problem.
6725 * So, just fall through. We will check it in test_pages_isolated().
6727 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
6728 if (ret
&& ret
!= -EBUSY
)
6732 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
6733 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
6734 * more, all pages in [start, end) are free in page allocator.
6735 * What we are going to do is to allocate all pages from
6736 * [start, end) (that is remove them from page allocator).
6738 * The only problem is that pages at the beginning and at the
6739 * end of interesting range may be not aligned with pages that
6740 * page allocator holds, ie. they can be part of higher order
6741 * pages. Because of this, we reserve the bigger range and
6742 * once this is done free the pages we are not interested in.
6744 * We don't have to hold zone->lock here because the pages are
6745 * isolated thus they won't get removed from buddy.
6748 lru_add_drain_all();
6749 drain_all_pages(cc
.zone
);
6752 outer_start
= start
;
6753 while (!PageBuddy(pfn_to_page(outer_start
))) {
6754 if (++order
>= MAX_ORDER
) {
6755 outer_start
= start
;
6758 outer_start
&= ~0UL << order
;
6761 if (outer_start
!= start
) {
6762 order
= page_order(pfn_to_page(outer_start
));
6765 * outer_start page could be small order buddy page and
6766 * it doesn't include start page. Adjust outer_start
6767 * in this case to report failed page properly
6768 * on tracepoint in test_pages_isolated()
6770 if (outer_start
+ (1UL << order
) <= start
)
6771 outer_start
= start
;
6774 /* Make sure the range is really isolated. */
6775 if (test_pages_isolated(outer_start
, end
, false)) {
6776 pr_info("%s: [%lx, %lx) PFNs busy\n",
6777 __func__
, outer_start
, end
);
6782 /* Grab isolated pages from freelists. */
6783 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
6789 /* Free head and tail (if any) */
6790 if (start
!= outer_start
)
6791 free_contig_range(outer_start
, start
- outer_start
);
6792 if (end
!= outer_end
)
6793 free_contig_range(end
, outer_end
- end
);
6796 undo_isolate_page_range(pfn_max_align_down(start
),
6797 pfn_max_align_up(end
), migratetype
);
6801 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
6803 unsigned int count
= 0;
6805 for (; nr_pages
--; pfn
++) {
6806 struct page
*page
= pfn_to_page(pfn
);
6808 count
+= page_count(page
) != 1;
6811 WARN(count
!= 0, "%d pages are still in use!\n", count
);
6815 #ifdef CONFIG_MEMORY_HOTPLUG
6817 * The zone indicated has a new number of managed_pages; batch sizes and percpu
6818 * page high values need to be recalulated.
6820 void __meminit
zone_pcp_update(struct zone
*zone
)
6823 mutex_lock(&pcp_batch_high_lock
);
6824 for_each_possible_cpu(cpu
)
6825 pageset_set_high_and_batch(zone
,
6826 per_cpu_ptr(zone
->pageset
, cpu
));
6827 mutex_unlock(&pcp_batch_high_lock
);
6831 void zone_pcp_reset(struct zone
*zone
)
6833 unsigned long flags
;
6835 struct per_cpu_pageset
*pset
;
6837 /* avoid races with drain_pages() */
6838 local_irq_save(flags
);
6839 if (zone
->pageset
!= &boot_pageset
) {
6840 for_each_online_cpu(cpu
) {
6841 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
6842 drain_zonestat(zone
, pset
);
6844 free_percpu(zone
->pageset
);
6845 zone
->pageset
= &boot_pageset
;
6847 local_irq_restore(flags
);
6850 #ifdef CONFIG_MEMORY_HOTREMOVE
6852 * All pages in the range must be isolated before calling this.
6855 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
6859 unsigned int order
, i
;
6861 unsigned long flags
;
6862 /* find the first valid pfn */
6863 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
6868 zone
= page_zone(pfn_to_page(pfn
));
6869 spin_lock_irqsave(&zone
->lock
, flags
);
6871 while (pfn
< end_pfn
) {
6872 if (!pfn_valid(pfn
)) {
6876 page
= pfn_to_page(pfn
);
6878 * The HWPoisoned page may be not in buddy system, and
6879 * page_count() is not 0.
6881 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
6883 SetPageReserved(page
);
6887 BUG_ON(page_count(page
));
6888 BUG_ON(!PageBuddy(page
));
6889 order
= page_order(page
);
6890 #ifdef CONFIG_DEBUG_VM
6891 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
6892 pfn
, 1 << order
, end_pfn
);
6894 list_del(&page
->lru
);
6895 rmv_page_order(page
);
6896 zone
->free_area
[order
].nr_free
--;
6897 for (i
= 0; i
< (1 << order
); i
++)
6898 SetPageReserved((page
+i
));
6899 pfn
+= (1 << order
);
6901 spin_unlock_irqrestore(&zone
->lock
, flags
);
6905 #ifdef CONFIG_MEMORY_FAILURE
6906 bool is_free_buddy_page(struct page
*page
)
6908 struct zone
*zone
= page_zone(page
);
6909 unsigned long pfn
= page_to_pfn(page
);
6910 unsigned long flags
;
6913 spin_lock_irqsave(&zone
->lock
, flags
);
6914 for (order
= 0; order
< MAX_ORDER
; order
++) {
6915 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
6917 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
6920 spin_unlock_irqrestore(&zone
->lock
, flags
);
6922 return order
< MAX_ORDER
;