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/module.h>
29 #include <linux/suspend.h>
30 #include <linux/pagevec.h>
31 #include <linux/blkdev.h>
32 #include <linux/slab.h>
33 #include <linux/ratelimit.h>
34 #include <linux/oom.h>
35 #include <linux/notifier.h>
36 #include <linux/topology.h>
37 #include <linux/sysctl.h>
38 #include <linux/cpu.h>
39 #include <linux/cpuset.h>
40 #include <linux/memory_hotplug.h>
41 #include <linux/nodemask.h>
42 #include <linux/vmalloc.h>
43 #include <linux/vmstat.h>
44 #include <linux/mempolicy.h>
45 #include <linux/stop_machine.h>
46 #include <linux/sort.h>
47 #include <linux/pfn.h>
48 #include <linux/backing-dev.h>
49 #include <linux/fault-inject.h>
50 #include <linux/page-isolation.h>
51 #include <linux/page_cgroup.h>
52 #include <linux/debugobjects.h>
53 #include <linux/kmemleak.h>
54 #include <linux/compaction.h>
55 #include <trace/events/kmem.h>
56 #include <linux/ftrace_event.h>
57 #include <linux/memcontrol.h>
58 #include <linux/prefetch.h>
59 #include <linux/migrate.h>
60 #include <linux/page-debug-flags.h>
62 #include <asm/tlbflush.h>
63 #include <asm/div64.h>
66 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
67 DEFINE_PER_CPU(int, numa_node
);
68 EXPORT_PER_CPU_SYMBOL(numa_node
);
71 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
73 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
74 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
75 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
76 * defined in <linux/topology.h>.
78 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
79 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
83 * Array of node states.
85 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
86 [N_POSSIBLE
] = NODE_MASK_ALL
,
87 [N_ONLINE
] = { { [0] = 1UL } },
89 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
91 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
93 [N_CPU
] = { { [0] = 1UL } },
96 EXPORT_SYMBOL(node_states
);
98 unsigned long totalram_pages __read_mostly
;
99 unsigned long totalreserve_pages __read_mostly
;
101 * When calculating the number of globally allowed dirty pages, there
102 * is a certain number of per-zone reserves that should not be
103 * considered dirtyable memory. This is the sum of those reserves
104 * over all existing zones that contribute dirtyable memory.
106 unsigned long dirty_balance_reserve __read_mostly
;
108 int percpu_pagelist_fraction
;
109 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
111 #ifdef CONFIG_PM_SLEEP
113 * The following functions are used by the suspend/hibernate code to temporarily
114 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
115 * while devices are suspended. To avoid races with the suspend/hibernate code,
116 * they should always be called with pm_mutex held (gfp_allowed_mask also should
117 * only be modified with pm_mutex held, unless the suspend/hibernate code is
118 * guaranteed not to run in parallel with that modification).
121 static gfp_t saved_gfp_mask
;
123 void pm_restore_gfp_mask(void)
125 WARN_ON(!mutex_is_locked(&pm_mutex
));
126 if (saved_gfp_mask
) {
127 gfp_allowed_mask
= saved_gfp_mask
;
132 void pm_restrict_gfp_mask(void)
134 WARN_ON(!mutex_is_locked(&pm_mutex
));
135 WARN_ON(saved_gfp_mask
);
136 saved_gfp_mask
= gfp_allowed_mask
;
137 gfp_allowed_mask
&= ~GFP_IOFS
;
140 bool pm_suspended_storage(void)
142 if ((gfp_allowed_mask
& GFP_IOFS
) == GFP_IOFS
)
146 #endif /* CONFIG_PM_SLEEP */
148 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
149 int pageblock_order __read_mostly
;
152 static void __free_pages_ok(struct page
*page
, unsigned int order
);
155 * results with 256, 32 in the lowmem_reserve sysctl:
156 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
157 * 1G machine -> (16M dma, 784M normal, 224M high)
158 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
159 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
160 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
162 * TBD: should special case ZONE_DMA32 machines here - in those we normally
163 * don't need any ZONE_NORMAL reservation
165 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
166 #ifdef CONFIG_ZONE_DMA
169 #ifdef CONFIG_ZONE_DMA32
172 #ifdef CONFIG_HIGHMEM
178 EXPORT_SYMBOL(totalram_pages
);
180 static char * const zone_names
[MAX_NR_ZONES
] = {
181 #ifdef CONFIG_ZONE_DMA
184 #ifdef CONFIG_ZONE_DMA32
188 #ifdef CONFIG_HIGHMEM
194 int min_free_kbytes
= 1024;
196 static unsigned long __meminitdata nr_kernel_pages
;
197 static unsigned long __meminitdata nr_all_pages
;
198 static unsigned long __meminitdata dma_reserve
;
200 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
201 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
202 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
203 static unsigned long __initdata required_kernelcore
;
204 static unsigned long __initdata required_movablecore
;
205 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
207 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
209 EXPORT_SYMBOL(movable_zone
);
210 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
213 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
214 int nr_online_nodes __read_mostly
= 1;
215 EXPORT_SYMBOL(nr_node_ids
);
216 EXPORT_SYMBOL(nr_online_nodes
);
219 int page_group_by_mobility_disabled __read_mostly
;
223 * Don't use set_pageblock_migratetype(page, MIGRATE_ISOLATE) directly.
224 * Instead, use {un}set_pageblock_isolate.
226 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
229 if (unlikely(page_group_by_mobility_disabled
))
230 migratetype
= MIGRATE_UNMOVABLE
;
232 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
233 PB_migrate
, PB_migrate_end
);
236 bool oom_killer_disabled __read_mostly
;
238 #ifdef CONFIG_DEBUG_VM
239 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
243 unsigned long pfn
= page_to_pfn(page
);
246 seq
= zone_span_seqbegin(zone
);
247 if (pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
249 else if (pfn
< zone
->zone_start_pfn
)
251 } while (zone_span_seqretry(zone
, seq
));
256 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
258 if (!pfn_valid_within(page_to_pfn(page
)))
260 if (zone
!= page_zone(page
))
266 * Temporary debugging check for pages not lying within a given zone.
268 static int bad_range(struct zone
*zone
, struct page
*page
)
270 if (page_outside_zone_boundaries(zone
, page
))
272 if (!page_is_consistent(zone
, page
))
278 static inline int bad_range(struct zone
*zone
, struct page
*page
)
284 static void bad_page(struct page
*page
)
286 static unsigned long resume
;
287 static unsigned long nr_shown
;
288 static unsigned long nr_unshown
;
290 /* Don't complain about poisoned pages */
291 if (PageHWPoison(page
)) {
292 reset_page_mapcount(page
); /* remove PageBuddy */
297 * Allow a burst of 60 reports, then keep quiet for that minute;
298 * or allow a steady drip of one report per second.
300 if (nr_shown
== 60) {
301 if (time_before(jiffies
, resume
)) {
307 "BUG: Bad page state: %lu messages suppressed\n",
314 resume
= jiffies
+ 60 * HZ
;
316 printk(KERN_ALERT
"BUG: Bad page state in process %s pfn:%05lx\n",
317 current
->comm
, page_to_pfn(page
));
323 /* Leave bad fields for debug, except PageBuddy could make trouble */
324 reset_page_mapcount(page
); /* remove PageBuddy */
325 add_taint(TAINT_BAD_PAGE
);
329 * Higher-order pages are called "compound pages". They are structured thusly:
331 * The first PAGE_SIZE page is called the "head page".
333 * The remaining PAGE_SIZE pages are called "tail pages".
335 * All pages have PG_compound set. All tail pages have their ->first_page
336 * pointing at the head page.
338 * The first tail page's ->lru.next holds the address of the compound page's
339 * put_page() function. Its ->lru.prev holds the order of allocation.
340 * This usage means that zero-order pages may not be compound.
343 static void free_compound_page(struct page
*page
)
345 __free_pages_ok(page
, compound_order(page
));
348 void prep_compound_page(struct page
*page
, unsigned long order
)
351 int nr_pages
= 1 << order
;
353 set_compound_page_dtor(page
, free_compound_page
);
354 set_compound_order(page
, order
);
356 for (i
= 1; i
< nr_pages
; i
++) {
357 struct page
*p
= page
+ i
;
359 set_page_count(p
, 0);
360 p
->first_page
= page
;
364 /* update __split_huge_page_refcount if you change this function */
365 static int destroy_compound_page(struct page
*page
, unsigned long order
)
368 int nr_pages
= 1 << order
;
371 if (unlikely(compound_order(page
) != order
) ||
372 unlikely(!PageHead(page
))) {
377 __ClearPageHead(page
);
379 for (i
= 1; i
< nr_pages
; i
++) {
380 struct page
*p
= page
+ i
;
382 if (unlikely(!PageTail(p
) || (p
->first_page
!= page
))) {
392 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
397 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
398 * and __GFP_HIGHMEM from hard or soft interrupt context.
400 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
401 for (i
= 0; i
< (1 << order
); i
++)
402 clear_highpage(page
+ i
);
405 #ifdef CONFIG_DEBUG_PAGEALLOC
406 unsigned int _debug_guardpage_minorder
;
408 static int __init
debug_guardpage_minorder_setup(char *buf
)
412 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
413 printk(KERN_ERR
"Bad debug_guardpage_minorder value\n");
416 _debug_guardpage_minorder
= res
;
417 printk(KERN_INFO
"Setting debug_guardpage_minorder to %lu\n", res
);
420 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
422 static inline void set_page_guard_flag(struct page
*page
)
424 __set_bit(PAGE_DEBUG_FLAG_GUARD
, &page
->debug_flags
);
427 static inline void clear_page_guard_flag(struct page
*page
)
429 __clear_bit(PAGE_DEBUG_FLAG_GUARD
, &page
->debug_flags
);
432 static inline void set_page_guard_flag(struct page
*page
) { }
433 static inline void clear_page_guard_flag(struct page
*page
) { }
436 static inline void set_page_order(struct page
*page
, int order
)
438 set_page_private(page
, order
);
439 __SetPageBuddy(page
);
442 static inline void rmv_page_order(struct page
*page
)
444 __ClearPageBuddy(page
);
445 set_page_private(page
, 0);
449 * Locate the struct page for both the matching buddy in our
450 * pair (buddy1) and the combined O(n+1) page they form (page).
452 * 1) Any buddy B1 will have an order O twin B2 which satisfies
453 * the following equation:
455 * For example, if the starting buddy (buddy2) is #8 its order
457 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
459 * 2) Any buddy B will have an order O+1 parent P which
460 * satisfies the following equation:
463 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
465 static inline unsigned long
466 __find_buddy_index(unsigned long page_idx
, unsigned int order
)
468 return page_idx
^ (1 << order
);
472 * This function checks whether a page is free && is the buddy
473 * we can do coalesce a page and its buddy if
474 * (a) the buddy is not in a hole &&
475 * (b) the buddy is in the buddy system &&
476 * (c) a page and its buddy have the same order &&
477 * (d) a page and its buddy are in the same zone.
479 * For recording whether a page is in the buddy system, we set ->_mapcount -2.
480 * Setting, clearing, and testing _mapcount -2 is serialized by zone->lock.
482 * For recording page's order, we use page_private(page).
484 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
487 if (!pfn_valid_within(page_to_pfn(buddy
)))
490 if (page_zone_id(page
) != page_zone_id(buddy
))
493 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
494 VM_BUG_ON(page_count(buddy
) != 0);
498 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
499 VM_BUG_ON(page_count(buddy
) != 0);
506 * Freeing function for a buddy system allocator.
508 * The concept of a buddy system is to maintain direct-mapped table
509 * (containing bit values) for memory blocks of various "orders".
510 * The bottom level table contains the map for the smallest allocatable
511 * units of memory (here, pages), and each level above it describes
512 * pairs of units from the levels below, hence, "buddies".
513 * At a high level, all that happens here is marking the table entry
514 * at the bottom level available, and propagating the changes upward
515 * as necessary, plus some accounting needed to play nicely with other
516 * parts of the VM system.
517 * At each level, we keep a list of pages, which are heads of continuous
518 * free pages of length of (1 << order) and marked with _mapcount -2. Page's
519 * order is recorded in page_private(page) field.
520 * So when we are allocating or freeing one, we can derive the state of the
521 * other. That is, if we allocate a small block, and both were
522 * free, the remainder of the region must be split into blocks.
523 * If a block is freed, and its buddy is also free, then this
524 * triggers coalescing into a block of larger size.
529 static inline void __free_one_page(struct page
*page
,
530 struct zone
*zone
, unsigned int order
,
533 unsigned long page_idx
;
534 unsigned long combined_idx
;
535 unsigned long uninitialized_var(buddy_idx
);
538 if (unlikely(PageCompound(page
)))
539 if (unlikely(destroy_compound_page(page
, order
)))
542 VM_BUG_ON(migratetype
== -1);
544 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
546 VM_BUG_ON(page_idx
& ((1 << order
) - 1));
547 VM_BUG_ON(bad_range(zone
, page
));
549 while (order
< MAX_ORDER
-1) {
550 buddy_idx
= __find_buddy_index(page_idx
, order
);
551 buddy
= page
+ (buddy_idx
- page_idx
);
552 if (!page_is_buddy(page
, buddy
, order
))
555 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
556 * merge with it and move up one order.
558 if (page_is_guard(buddy
)) {
559 clear_page_guard_flag(buddy
);
560 set_page_private(page
, 0);
561 __mod_zone_freepage_state(zone
, 1 << order
,
564 list_del(&buddy
->lru
);
565 zone
->free_area
[order
].nr_free
--;
566 rmv_page_order(buddy
);
568 combined_idx
= buddy_idx
& page_idx
;
569 page
= page
+ (combined_idx
- page_idx
);
570 page_idx
= combined_idx
;
573 set_page_order(page
, order
);
576 * If this is not the largest possible page, check if the buddy
577 * of the next-highest order is free. If it is, it's possible
578 * that pages are being freed that will coalesce soon. In case,
579 * that is happening, add the free page to the tail of the list
580 * so it's less likely to be used soon and more likely to be merged
581 * as a higher order page
583 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
584 struct page
*higher_page
, *higher_buddy
;
585 combined_idx
= buddy_idx
& page_idx
;
586 higher_page
= page
+ (combined_idx
- page_idx
);
587 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
588 higher_buddy
= higher_page
+ (buddy_idx
- combined_idx
);
589 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
590 list_add_tail(&page
->lru
,
591 &zone
->free_area
[order
].free_list
[migratetype
]);
596 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
598 zone
->free_area
[order
].nr_free
++;
601 static inline int free_pages_check(struct page
*page
)
603 if (unlikely(page_mapcount(page
) |
604 (page
->mapping
!= NULL
) |
605 (atomic_read(&page
->_count
) != 0) |
606 (page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
) |
607 (mem_cgroup_bad_page_check(page
)))) {
611 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
612 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
617 * Frees a number of pages from the PCP lists
618 * Assumes all pages on list are in same zone, and of same order.
619 * count is the number of pages to free.
621 * If the zone was previously in an "all pages pinned" state then look to
622 * see if this freeing clears that state.
624 * And clear the zone's pages_scanned counter, to hold off the "all pages are
625 * pinned" detection logic.
627 static void free_pcppages_bulk(struct zone
*zone
, int count
,
628 struct per_cpu_pages
*pcp
)
634 spin_lock(&zone
->lock
);
635 zone
->all_unreclaimable
= 0;
636 zone
->pages_scanned
= 0;
640 struct list_head
*list
;
643 * Remove pages from lists in a round-robin fashion. A
644 * batch_free count is maintained that is incremented when an
645 * empty list is encountered. This is so more pages are freed
646 * off fuller lists instead of spinning excessively around empty
651 if (++migratetype
== MIGRATE_PCPTYPES
)
653 list
= &pcp
->lists
[migratetype
];
654 } while (list_empty(list
));
656 /* This is the only non-empty list. Free them all. */
657 if (batch_free
== MIGRATE_PCPTYPES
)
658 batch_free
= to_free
;
661 int mt
; /* migratetype of the to-be-freed page */
663 page
= list_entry(list
->prev
, struct page
, lru
);
664 /* must delete as __free_one_page list manipulates */
665 list_del(&page
->lru
);
666 mt
= get_freepage_migratetype(page
);
667 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
668 __free_one_page(page
, zone
, 0, mt
);
669 trace_mm_page_pcpu_drain(page
, 0, mt
);
670 if (is_migrate_cma(mt
))
671 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
, 1);
672 } while (--to_free
&& --batch_free
&& !list_empty(list
));
674 __mod_zone_page_state(zone
, NR_FREE_PAGES
, count
);
675 spin_unlock(&zone
->lock
);
678 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
,
681 spin_lock(&zone
->lock
);
682 zone
->all_unreclaimable
= 0;
683 zone
->pages_scanned
= 0;
685 __free_one_page(page
, zone
, order
, migratetype
);
686 if (unlikely(migratetype
!= MIGRATE_ISOLATE
))
687 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
688 spin_unlock(&zone
->lock
);
691 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
696 trace_mm_page_free(page
, order
);
697 kmemcheck_free_shadow(page
, order
);
700 page
->mapping
= NULL
;
701 for (i
= 0; i
< (1 << order
); i
++)
702 bad
+= free_pages_check(page
+ i
);
706 if (!PageHighMem(page
)) {
707 debug_check_no_locks_freed(page_address(page
),PAGE_SIZE
<<order
);
708 debug_check_no_obj_freed(page_address(page
),
711 arch_free_page(page
, order
);
712 kernel_map_pages(page
, 1 << order
, 0);
717 static void __free_pages_ok(struct page
*page
, unsigned int order
)
722 if (!free_pages_prepare(page
, order
))
725 local_irq_save(flags
);
726 __count_vm_events(PGFREE
, 1 << order
);
727 migratetype
= get_pageblock_migratetype(page
);
728 set_freepage_migratetype(page
, migratetype
);
729 free_one_page(page_zone(page
), page
, order
, migratetype
);
730 local_irq_restore(flags
);
733 void __meminit
__free_pages_bootmem(struct page
*page
, unsigned int order
)
735 unsigned int nr_pages
= 1 << order
;
739 for (loop
= 0; loop
< nr_pages
; loop
++) {
740 struct page
*p
= &page
[loop
];
742 if (loop
+ 1 < nr_pages
)
744 __ClearPageReserved(p
);
745 set_page_count(p
, 0);
748 set_page_refcounted(page
);
749 __free_pages(page
, order
);
753 /* Free whole pageblock and set it's migration type to MIGRATE_CMA. */
754 void __init
init_cma_reserved_pageblock(struct page
*page
)
756 unsigned i
= pageblock_nr_pages
;
757 struct page
*p
= page
;
760 __ClearPageReserved(p
);
761 set_page_count(p
, 0);
764 set_page_refcounted(page
);
765 set_pageblock_migratetype(page
, MIGRATE_CMA
);
766 __free_pages(page
, pageblock_order
);
767 totalram_pages
+= pageblock_nr_pages
;
772 * The order of subdivision here is critical for the IO subsystem.
773 * Please do not alter this order without good reasons and regression
774 * testing. Specifically, as large blocks of memory are subdivided,
775 * the order in which smaller blocks are delivered depends on the order
776 * they're subdivided in this function. This is the primary factor
777 * influencing the order in which pages are delivered to the IO
778 * subsystem according to empirical testing, and this is also justified
779 * by considering the behavior of a buddy system containing a single
780 * large block of memory acted on by a series of small allocations.
781 * This behavior is a critical factor in sglist merging's success.
785 static inline void expand(struct zone
*zone
, struct page
*page
,
786 int low
, int high
, struct free_area
*area
,
789 unsigned long size
= 1 << high
;
795 VM_BUG_ON(bad_range(zone
, &page
[size
]));
797 #ifdef CONFIG_DEBUG_PAGEALLOC
798 if (high
< debug_guardpage_minorder()) {
800 * Mark as guard pages (or page), that will allow to
801 * merge back to allocator when buddy will be freed.
802 * Corresponding page table entries will not be touched,
803 * pages will stay not present in virtual address space
805 INIT_LIST_HEAD(&page
[size
].lru
);
806 set_page_guard_flag(&page
[size
]);
807 set_page_private(&page
[size
], high
);
808 /* Guard pages are not available for any usage */
809 __mod_zone_freepage_state(zone
, -(1 << high
),
814 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
816 set_page_order(&page
[size
], high
);
821 * This page is about to be returned from the page allocator
823 static inline int check_new_page(struct page
*page
)
825 if (unlikely(page_mapcount(page
) |
826 (page
->mapping
!= NULL
) |
827 (atomic_read(&page
->_count
) != 0) |
828 (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
) |
829 (mem_cgroup_bad_page_check(page
)))) {
836 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
840 for (i
= 0; i
< (1 << order
); i
++) {
841 struct page
*p
= page
+ i
;
842 if (unlikely(check_new_page(p
)))
846 set_page_private(page
, 0);
847 set_page_refcounted(page
);
849 arch_alloc_page(page
, order
);
850 kernel_map_pages(page
, 1 << order
, 1);
852 if (gfp_flags
& __GFP_ZERO
)
853 prep_zero_page(page
, order
, gfp_flags
);
855 if (order
&& (gfp_flags
& __GFP_COMP
))
856 prep_compound_page(page
, order
);
862 * Go through the free lists for the given migratetype and remove
863 * the smallest available page from the freelists
866 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
869 unsigned int current_order
;
870 struct free_area
* area
;
873 /* Find a page of the appropriate size in the preferred list */
874 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
875 area
= &(zone
->free_area
[current_order
]);
876 if (list_empty(&area
->free_list
[migratetype
]))
879 page
= list_entry(area
->free_list
[migratetype
].next
,
881 list_del(&page
->lru
);
882 rmv_page_order(page
);
884 expand(zone
, page
, order
, current_order
, area
, migratetype
);
893 * This array describes the order lists are fallen back to when
894 * the free lists for the desirable migrate type are depleted
896 static int fallbacks
[MIGRATE_TYPES
][4] = {
897 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
898 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
900 [MIGRATE_MOVABLE
] = { MIGRATE_CMA
, MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
901 [MIGRATE_CMA
] = { MIGRATE_RESERVE
}, /* Never used */
903 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
905 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
}, /* Never used */
906 [MIGRATE_ISOLATE
] = { MIGRATE_RESERVE
}, /* Never used */
910 * Move the free pages in a range to the free lists of the requested type.
911 * Note that start_page and end_pages are not aligned on a pageblock
912 * boundary. If alignment is required, use move_freepages_block()
914 int move_freepages(struct zone
*zone
,
915 struct page
*start_page
, struct page
*end_page
,
922 #ifndef CONFIG_HOLES_IN_ZONE
924 * page_zone is not safe to call in this context when
925 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
926 * anyway as we check zone boundaries in move_freepages_block().
927 * Remove at a later date when no bug reports exist related to
928 * grouping pages by mobility
930 BUG_ON(page_zone(start_page
) != page_zone(end_page
));
933 for (page
= start_page
; page
<= end_page
;) {
934 /* Make sure we are not inadvertently changing nodes */
935 VM_BUG_ON(page_to_nid(page
) != zone_to_nid(zone
));
937 if (!pfn_valid_within(page_to_pfn(page
))) {
942 if (!PageBuddy(page
)) {
947 order
= page_order(page
);
948 list_move(&page
->lru
,
949 &zone
->free_area
[order
].free_list
[migratetype
]);
950 set_freepage_migratetype(page
, migratetype
);
952 pages_moved
+= 1 << order
;
958 int move_freepages_block(struct zone
*zone
, struct page
*page
,
961 unsigned long start_pfn
, end_pfn
;
962 struct page
*start_page
, *end_page
;
964 start_pfn
= page_to_pfn(page
);
965 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
966 start_page
= pfn_to_page(start_pfn
);
967 end_page
= start_page
+ pageblock_nr_pages
- 1;
968 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
970 /* Do not cross zone boundaries */
971 if (start_pfn
< zone
->zone_start_pfn
)
973 if (end_pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
976 return move_freepages(zone
, start_page
, end_page
, migratetype
);
979 static void change_pageblock_range(struct page
*pageblock_page
,
980 int start_order
, int migratetype
)
982 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
984 while (nr_pageblocks
--) {
985 set_pageblock_migratetype(pageblock_page
, migratetype
);
986 pageblock_page
+= pageblock_nr_pages
;
990 /* Remove an element from the buddy allocator from the fallback list */
991 static inline struct page
*
992 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
)
994 struct free_area
* area
;
999 /* Find the largest possible block of pages in the other list */
1000 for (current_order
= MAX_ORDER
-1; current_order
>= order
;
1003 migratetype
= fallbacks
[start_migratetype
][i
];
1005 /* MIGRATE_RESERVE handled later if necessary */
1006 if (migratetype
== MIGRATE_RESERVE
)
1009 area
= &(zone
->free_area
[current_order
]);
1010 if (list_empty(&area
->free_list
[migratetype
]))
1013 page
= list_entry(area
->free_list
[migratetype
].next
,
1018 * If breaking a large block of pages, move all free
1019 * pages to the preferred allocation list. If falling
1020 * back for a reclaimable kernel allocation, be more
1021 * aggressive about taking ownership of free pages
1023 * On the other hand, never change migration
1024 * type of MIGRATE_CMA pageblocks nor move CMA
1025 * pages on different free lists. We don't
1026 * want unmovable pages to be allocated from
1027 * MIGRATE_CMA areas.
1029 if (!is_migrate_cma(migratetype
) &&
1030 (unlikely(current_order
>= pageblock_order
/ 2) ||
1031 start_migratetype
== MIGRATE_RECLAIMABLE
||
1032 page_group_by_mobility_disabled
)) {
1034 pages
= move_freepages_block(zone
, page
,
1037 /* Claim the whole block if over half of it is free */
1038 if (pages
>= (1 << (pageblock_order
-1)) ||
1039 page_group_by_mobility_disabled
)
1040 set_pageblock_migratetype(page
,
1043 migratetype
= start_migratetype
;
1046 /* Remove the page from the freelists */
1047 list_del(&page
->lru
);
1048 rmv_page_order(page
);
1050 /* Take ownership for orders >= pageblock_order */
1051 if (current_order
>= pageblock_order
&&
1052 !is_migrate_cma(migratetype
))
1053 change_pageblock_range(page
, current_order
,
1056 expand(zone
, page
, order
, current_order
, area
,
1057 is_migrate_cma(migratetype
)
1058 ? migratetype
: start_migratetype
);
1060 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
1061 start_migratetype
, migratetype
);
1071 * Do the hard work of removing an element from the buddy allocator.
1072 * Call me with the zone->lock already held.
1074 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
1080 page
= __rmqueue_smallest(zone
, order
, migratetype
);
1082 if (unlikely(!page
) && migratetype
!= MIGRATE_RESERVE
) {
1083 page
= __rmqueue_fallback(zone
, order
, migratetype
);
1086 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1087 * is used because __rmqueue_smallest is an inline function
1088 * and we want just one call site
1091 migratetype
= MIGRATE_RESERVE
;
1096 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1101 * Obtain a specified number of elements from the buddy allocator, all under
1102 * a single hold of the lock, for efficiency. Add them to the supplied list.
1103 * Returns the number of new pages which were placed at *list.
1105 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1106 unsigned long count
, struct list_head
*list
,
1107 int migratetype
, int cold
)
1109 int mt
= migratetype
, i
;
1111 spin_lock(&zone
->lock
);
1112 for (i
= 0; i
< count
; ++i
) {
1113 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
1114 if (unlikely(page
== NULL
))
1118 * Split buddy pages returned by expand() are received here
1119 * in physical page order. The page is added to the callers and
1120 * list and the list head then moves forward. From the callers
1121 * perspective, the linked list is ordered by page number in
1122 * some conditions. This is useful for IO devices that can
1123 * merge IO requests if the physical pages are ordered
1126 if (likely(cold
== 0))
1127 list_add(&page
->lru
, list
);
1129 list_add_tail(&page
->lru
, list
);
1130 if (IS_ENABLED(CONFIG_CMA
)) {
1131 mt
= get_pageblock_migratetype(page
);
1132 if (!is_migrate_cma(mt
) && mt
!= MIGRATE_ISOLATE
)
1135 set_freepage_migratetype(page
, mt
);
1137 if (is_migrate_cma(mt
))
1138 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
1141 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
1142 spin_unlock(&zone
->lock
);
1148 * Called from the vmstat counter updater to drain pagesets of this
1149 * currently executing processor on remote nodes after they have
1152 * Note that this function must be called with the thread pinned to
1153 * a single processor.
1155 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
1157 unsigned long flags
;
1160 local_irq_save(flags
);
1161 if (pcp
->count
>= pcp
->batch
)
1162 to_drain
= pcp
->batch
;
1164 to_drain
= pcp
->count
;
1166 free_pcppages_bulk(zone
, to_drain
, pcp
);
1167 pcp
->count
-= to_drain
;
1169 local_irq_restore(flags
);
1174 * Drain pages of the indicated processor.
1176 * The processor must either be the current processor and the
1177 * thread pinned to the current processor or a processor that
1180 static void drain_pages(unsigned int cpu
)
1182 unsigned long flags
;
1185 for_each_populated_zone(zone
) {
1186 struct per_cpu_pageset
*pset
;
1187 struct per_cpu_pages
*pcp
;
1189 local_irq_save(flags
);
1190 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
1194 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1197 local_irq_restore(flags
);
1202 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1204 void drain_local_pages(void *arg
)
1206 drain_pages(smp_processor_id());
1210 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1212 * Note that this code is protected against sending an IPI to an offline
1213 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1214 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1215 * nothing keeps CPUs from showing up after we populated the cpumask and
1216 * before the call to on_each_cpu_mask().
1218 void drain_all_pages(void)
1221 struct per_cpu_pageset
*pcp
;
1225 * Allocate in the BSS so we wont require allocation in
1226 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1228 static cpumask_t cpus_with_pcps
;
1231 * We don't care about racing with CPU hotplug event
1232 * as offline notification will cause the notified
1233 * cpu to drain that CPU pcps and on_each_cpu_mask
1234 * disables preemption as part of its processing
1236 for_each_online_cpu(cpu
) {
1237 bool has_pcps
= false;
1238 for_each_populated_zone(zone
) {
1239 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
1240 if (pcp
->pcp
.count
) {
1246 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
1248 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
1250 on_each_cpu_mask(&cpus_with_pcps
, drain_local_pages
, NULL
, 1);
1253 #ifdef CONFIG_HIBERNATION
1255 void mark_free_pages(struct zone
*zone
)
1257 unsigned long pfn
, max_zone_pfn
;
1258 unsigned long flags
;
1260 struct list_head
*curr
;
1262 if (!zone
->spanned_pages
)
1265 spin_lock_irqsave(&zone
->lock
, flags
);
1267 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
1268 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1269 if (pfn_valid(pfn
)) {
1270 struct page
*page
= pfn_to_page(pfn
);
1272 if (!swsusp_page_is_forbidden(page
))
1273 swsusp_unset_page_free(page
);
1276 for_each_migratetype_order(order
, t
) {
1277 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
1280 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
1281 for (i
= 0; i
< (1UL << order
); i
++)
1282 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
1285 spin_unlock_irqrestore(&zone
->lock
, flags
);
1287 #endif /* CONFIG_PM */
1290 * Free a 0-order page
1291 * cold == 1 ? free a cold page : free a hot page
1293 void free_hot_cold_page(struct page
*page
, int cold
)
1295 struct zone
*zone
= page_zone(page
);
1296 struct per_cpu_pages
*pcp
;
1297 unsigned long flags
;
1300 if (!free_pages_prepare(page
, 0))
1303 migratetype
= get_pageblock_migratetype(page
);
1304 set_freepage_migratetype(page
, migratetype
);
1305 local_irq_save(flags
);
1306 __count_vm_event(PGFREE
);
1309 * We only track unmovable, reclaimable and movable on pcp lists.
1310 * Free ISOLATE pages back to the allocator because they are being
1311 * offlined but treat RESERVE as movable pages so we can get those
1312 * areas back if necessary. Otherwise, we may have to free
1313 * excessively into the page allocator
1315 if (migratetype
>= MIGRATE_PCPTYPES
) {
1316 if (unlikely(migratetype
== MIGRATE_ISOLATE
)) {
1317 free_one_page(zone
, page
, 0, migratetype
);
1320 migratetype
= MIGRATE_MOVABLE
;
1323 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1325 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
1327 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
1329 if (pcp
->count
>= pcp
->high
) {
1330 free_pcppages_bulk(zone
, pcp
->batch
, pcp
);
1331 pcp
->count
-= pcp
->batch
;
1335 local_irq_restore(flags
);
1339 * Free a list of 0-order pages
1341 void free_hot_cold_page_list(struct list_head
*list
, int cold
)
1343 struct page
*page
, *next
;
1345 list_for_each_entry_safe(page
, next
, list
, lru
) {
1346 trace_mm_page_free_batched(page
, cold
);
1347 free_hot_cold_page(page
, cold
);
1352 * split_page takes a non-compound higher-order page, and splits it into
1353 * n (1<<order) sub-pages: page[0..n]
1354 * Each sub-page must be freed individually.
1356 * Note: this is probably too low level an operation for use in drivers.
1357 * Please consult with lkml before using this in your driver.
1359 void split_page(struct page
*page
, unsigned int order
)
1363 VM_BUG_ON(PageCompound(page
));
1364 VM_BUG_ON(!page_count(page
));
1366 #ifdef CONFIG_KMEMCHECK
1368 * Split shadow pages too, because free(page[0]) would
1369 * otherwise free the whole shadow.
1371 if (kmemcheck_page_is_tracked(page
))
1372 split_page(virt_to_page(page
[0].shadow
), order
);
1375 for (i
= 1; i
< (1 << order
); i
++)
1376 set_page_refcounted(page
+ i
);
1380 * Similar to the split_page family of functions except that the page
1381 * required at the given order and being isolated now to prevent races
1382 * with parallel allocators
1384 int capture_free_page(struct page
*page
, int alloc_order
, int migratetype
)
1387 unsigned long watermark
;
1391 BUG_ON(!PageBuddy(page
));
1393 zone
= page_zone(page
);
1394 order
= page_order(page
);
1396 /* Obey watermarks as if the page was being allocated */
1397 watermark
= low_wmark_pages(zone
) + (1 << order
);
1398 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
1401 /* Remove page from free list */
1402 list_del(&page
->lru
);
1403 zone
->free_area
[order
].nr_free
--;
1404 rmv_page_order(page
);
1406 mt
= get_pageblock_migratetype(page
);
1407 if (unlikely(mt
!= MIGRATE_ISOLATE
))
1408 __mod_zone_freepage_state(zone
, -(1UL << alloc_order
), mt
);
1410 if (alloc_order
!= order
)
1411 expand(zone
, page
, alloc_order
, order
,
1412 &zone
->free_area
[order
], migratetype
);
1414 /* Set the pageblock if the captured page is at least a pageblock */
1415 if (order
>= pageblock_order
- 1) {
1416 struct page
*endpage
= page
+ (1 << order
) - 1;
1417 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
1418 int mt
= get_pageblock_migratetype(page
);
1419 if (mt
!= MIGRATE_ISOLATE
&& !is_migrate_cma(mt
))
1420 set_pageblock_migratetype(page
,
1425 return 1UL << order
;
1429 * Similar to split_page except the page is already free. As this is only
1430 * being used for migration, the migratetype of the block also changes.
1431 * As this is called with interrupts disabled, the caller is responsible
1432 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1435 * Note: this is probably too low level an operation for use in drivers.
1436 * Please consult with lkml before using this in your driver.
1438 int split_free_page(struct page
*page
)
1443 BUG_ON(!PageBuddy(page
));
1444 order
= page_order(page
);
1446 nr_pages
= capture_free_page(page
, order
, 0);
1450 /* Split into individual pages */
1451 set_page_refcounted(page
);
1452 split_page(page
, order
);
1457 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1458 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1462 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
1463 struct zone
*zone
, int order
, gfp_t gfp_flags
,
1466 unsigned long flags
;
1468 int cold
= !!(gfp_flags
& __GFP_COLD
);
1471 if (likely(order
== 0)) {
1472 struct per_cpu_pages
*pcp
;
1473 struct list_head
*list
;
1475 local_irq_save(flags
);
1476 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1477 list
= &pcp
->lists
[migratetype
];
1478 if (list_empty(list
)) {
1479 pcp
->count
+= rmqueue_bulk(zone
, 0,
1482 if (unlikely(list_empty(list
)))
1487 page
= list_entry(list
->prev
, struct page
, lru
);
1489 page
= list_entry(list
->next
, struct page
, lru
);
1491 list_del(&page
->lru
);
1494 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
1496 * __GFP_NOFAIL is not to be used in new code.
1498 * All __GFP_NOFAIL callers should be fixed so that they
1499 * properly detect and handle allocation failures.
1501 * We most definitely don't want callers attempting to
1502 * allocate greater than order-1 page units with
1505 WARN_ON_ONCE(order
> 1);
1507 spin_lock_irqsave(&zone
->lock
, flags
);
1508 page
= __rmqueue(zone
, order
, migratetype
);
1509 spin_unlock(&zone
->lock
);
1512 __mod_zone_freepage_state(zone
, -(1 << order
),
1513 get_pageblock_migratetype(page
));
1516 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
1517 zone_statistics(preferred_zone
, zone
, gfp_flags
);
1518 local_irq_restore(flags
);
1520 VM_BUG_ON(bad_range(zone
, page
));
1521 if (prep_new_page(page
, order
, gfp_flags
))
1526 local_irq_restore(flags
);
1530 #ifdef CONFIG_FAIL_PAGE_ALLOC
1533 struct fault_attr attr
;
1535 u32 ignore_gfp_highmem
;
1536 u32 ignore_gfp_wait
;
1538 } fail_page_alloc
= {
1539 .attr
= FAULT_ATTR_INITIALIZER
,
1540 .ignore_gfp_wait
= 1,
1541 .ignore_gfp_highmem
= 1,
1545 static int __init
setup_fail_page_alloc(char *str
)
1547 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
1549 __setup("fail_page_alloc=", setup_fail_page_alloc
);
1551 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1553 if (order
< fail_page_alloc
.min_order
)
1555 if (gfp_mask
& __GFP_NOFAIL
)
1557 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
1559 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
1562 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
1565 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1567 static int __init
fail_page_alloc_debugfs(void)
1569 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
1572 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
1573 &fail_page_alloc
.attr
);
1575 return PTR_ERR(dir
);
1577 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
1578 &fail_page_alloc
.ignore_gfp_wait
))
1580 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
1581 &fail_page_alloc
.ignore_gfp_highmem
))
1583 if (!debugfs_create_u32("min-order", mode
, dir
,
1584 &fail_page_alloc
.min_order
))
1589 debugfs_remove_recursive(dir
);
1594 late_initcall(fail_page_alloc_debugfs
);
1596 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1598 #else /* CONFIG_FAIL_PAGE_ALLOC */
1600 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1605 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1608 * Return true if free pages are above 'mark'. This takes into account the order
1609 * of the allocation.
1611 static bool __zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1612 int classzone_idx
, int alloc_flags
, long free_pages
)
1614 /* free_pages my go negative - that's OK */
1616 long lowmem_reserve
= z
->lowmem_reserve
[classzone_idx
];
1619 free_pages
-= (1 << order
) - 1;
1620 if (alloc_flags
& ALLOC_HIGH
)
1622 if (alloc_flags
& ALLOC_HARDER
)
1625 /* If allocation can't use CMA areas don't use free CMA pages */
1626 if (!(alloc_flags
& ALLOC_CMA
))
1627 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
1629 if (free_pages
<= min
+ lowmem_reserve
)
1631 for (o
= 0; o
< order
; o
++) {
1632 /* At the next order, this order's pages become unavailable */
1633 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1635 /* Require fewer higher order pages to be free */
1638 if (free_pages
<= min
)
1644 #ifdef CONFIG_MEMORY_ISOLATION
1645 static inline unsigned long nr_zone_isolate_freepages(struct zone
*zone
)
1647 if (unlikely(zone
->nr_pageblock_isolate
))
1648 return zone
->nr_pageblock_isolate
* pageblock_nr_pages
;
1652 static inline unsigned long nr_zone_isolate_freepages(struct zone
*zone
)
1658 bool zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1659 int classzone_idx
, int alloc_flags
)
1661 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1662 zone_page_state(z
, NR_FREE_PAGES
));
1665 bool zone_watermark_ok_safe(struct zone
*z
, int order
, unsigned long mark
,
1666 int classzone_idx
, int alloc_flags
)
1668 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
1670 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
1671 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
1674 * If the zone has MIGRATE_ISOLATE type free pages, we should consider
1675 * it. nr_zone_isolate_freepages is never accurate so kswapd might not
1676 * sleep although it could do so. But this is more desirable for memory
1677 * hotplug than sleeping which can cause a livelock in the direct
1680 free_pages
-= nr_zone_isolate_freepages(z
);
1681 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1687 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1688 * skip over zones that are not allowed by the cpuset, or that have
1689 * been recently (in last second) found to be nearly full. See further
1690 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1691 * that have to skip over a lot of full or unallowed zones.
1693 * If the zonelist cache is present in the passed in zonelist, then
1694 * returns a pointer to the allowed node mask (either the current
1695 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1697 * If the zonelist cache is not available for this zonelist, does
1698 * nothing and returns NULL.
1700 * If the fullzones BITMAP in the zonelist cache is stale (more than
1701 * a second since last zap'd) then we zap it out (clear its bits.)
1703 * We hold off even calling zlc_setup, until after we've checked the
1704 * first zone in the zonelist, on the theory that most allocations will
1705 * be satisfied from that first zone, so best to examine that zone as
1706 * quickly as we can.
1708 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1710 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1711 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1713 zlc
= zonelist
->zlcache_ptr
;
1717 if (time_after(jiffies
, zlc
->last_full_zap
+ HZ
)) {
1718 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1719 zlc
->last_full_zap
= jiffies
;
1722 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1723 &cpuset_current_mems_allowed
:
1724 &node_states
[N_HIGH_MEMORY
];
1725 return allowednodes
;
1729 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1730 * if it is worth looking at further for free memory:
1731 * 1) Check that the zone isn't thought to be full (doesn't have its
1732 * bit set in the zonelist_cache fullzones BITMAP).
1733 * 2) Check that the zones node (obtained from the zonelist_cache
1734 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1735 * Return true (non-zero) if zone is worth looking at further, or
1736 * else return false (zero) if it is not.
1738 * This check -ignores- the distinction between various watermarks,
1739 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1740 * found to be full for any variation of these watermarks, it will
1741 * be considered full for up to one second by all requests, unless
1742 * we are so low on memory on all allowed nodes that we are forced
1743 * into the second scan of the zonelist.
1745 * In the second scan we ignore this zonelist cache and exactly
1746 * apply the watermarks to all zones, even it is slower to do so.
1747 * We are low on memory in the second scan, and should leave no stone
1748 * unturned looking for a free page.
1750 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1751 nodemask_t
*allowednodes
)
1753 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1754 int i
; /* index of *z in zonelist zones */
1755 int n
; /* node that zone *z is on */
1757 zlc
= zonelist
->zlcache_ptr
;
1761 i
= z
- zonelist
->_zonerefs
;
1764 /* This zone is worth trying if it is allowed but not full */
1765 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1769 * Given 'z' scanning a zonelist, set the corresponding bit in
1770 * zlc->fullzones, so that subsequent attempts to allocate a page
1771 * from that zone don't waste time re-examining it.
1773 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1775 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1776 int i
; /* index of *z in zonelist zones */
1778 zlc
= zonelist
->zlcache_ptr
;
1782 i
= z
- zonelist
->_zonerefs
;
1784 set_bit(i
, zlc
->fullzones
);
1788 * clear all zones full, called after direct reclaim makes progress so that
1789 * a zone that was recently full is not skipped over for up to a second
1791 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
1793 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1795 zlc
= zonelist
->zlcache_ptr
;
1799 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1802 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
1804 return node_isset(local_zone
->node
, zone
->zone_pgdat
->reclaim_nodes
);
1807 static void __paginginit
init_zone_allows_reclaim(int nid
)
1811 for_each_online_node(i
)
1812 if (node_distance(nid
, i
) <= RECLAIM_DISTANCE
)
1813 node_set(i
, NODE_DATA(nid
)->reclaim_nodes
);
1815 zone_reclaim_mode
= 1;
1818 #else /* CONFIG_NUMA */
1820 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1825 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1826 nodemask_t
*allowednodes
)
1831 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1835 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
1839 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
1844 static inline void init_zone_allows_reclaim(int nid
)
1847 #endif /* CONFIG_NUMA */
1850 * get_page_from_freelist goes through the zonelist trying to allocate
1853 static struct page
*
1854 get_page_from_freelist(gfp_t gfp_mask
, nodemask_t
*nodemask
, unsigned int order
,
1855 struct zonelist
*zonelist
, int high_zoneidx
, int alloc_flags
,
1856 struct zone
*preferred_zone
, int migratetype
)
1859 struct page
*page
= NULL
;
1862 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1863 int zlc_active
= 0; /* set if using zonelist_cache */
1864 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1866 classzone_idx
= zone_idx(preferred_zone
);
1869 * Scan zonelist, looking for a zone with enough free.
1870 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1872 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
1873 high_zoneidx
, nodemask
) {
1874 if (NUMA_BUILD
&& zlc_active
&&
1875 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1877 if ((alloc_flags
& ALLOC_CPUSET
) &&
1878 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1881 * When allocating a page cache page for writing, we
1882 * want to get it from a zone that is within its dirty
1883 * limit, such that no single zone holds more than its
1884 * proportional share of globally allowed dirty pages.
1885 * The dirty limits take into account the zone's
1886 * lowmem reserves and high watermark so that kswapd
1887 * should be able to balance it without having to
1888 * write pages from its LRU list.
1890 * This may look like it could increase pressure on
1891 * lower zones by failing allocations in higher zones
1892 * before they are full. But the pages that do spill
1893 * over are limited as the lower zones are protected
1894 * by this very same mechanism. It should not become
1895 * a practical burden to them.
1897 * XXX: For now, allow allocations to potentially
1898 * exceed the per-zone dirty limit in the slowpath
1899 * (ALLOC_WMARK_LOW unset) before going into reclaim,
1900 * which is important when on a NUMA setup the allowed
1901 * zones are together not big enough to reach the
1902 * global limit. The proper fix for these situations
1903 * will require awareness of zones in the
1904 * dirty-throttling and the flusher threads.
1906 if ((alloc_flags
& ALLOC_WMARK_LOW
) &&
1907 (gfp_mask
& __GFP_WRITE
) && !zone_dirty_ok(zone
))
1908 goto this_zone_full
;
1910 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
1911 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
1915 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
1916 if (zone_watermark_ok(zone
, order
, mark
,
1917 classzone_idx
, alloc_flags
))
1920 if (NUMA_BUILD
&& !did_zlc_setup
&& nr_online_nodes
> 1) {
1922 * we do zlc_setup if there are multiple nodes
1923 * and before considering the first zone allowed
1926 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1931 if (zone_reclaim_mode
== 0 ||
1932 !zone_allows_reclaim(preferred_zone
, zone
))
1933 goto this_zone_full
;
1936 * As we may have just activated ZLC, check if the first
1937 * eligible zone has failed zone_reclaim recently.
1939 if (NUMA_BUILD
&& zlc_active
&&
1940 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1943 ret
= zone_reclaim(zone
, gfp_mask
, order
);
1945 case ZONE_RECLAIM_NOSCAN
:
1948 case ZONE_RECLAIM_FULL
:
1949 /* scanned but unreclaimable */
1952 /* did we reclaim enough */
1953 if (!zone_watermark_ok(zone
, order
, mark
,
1954 classzone_idx
, alloc_flags
))
1955 goto this_zone_full
;
1960 page
= buffered_rmqueue(preferred_zone
, zone
, order
,
1961 gfp_mask
, migratetype
);
1966 zlc_mark_zone_full(zonelist
, z
);
1969 if (unlikely(NUMA_BUILD
&& page
== NULL
&& zlc_active
)) {
1970 /* Disable zlc cache for second zonelist scan */
1977 * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was
1978 * necessary to allocate the page. The expectation is
1979 * that the caller is taking steps that will free more
1980 * memory. The caller should avoid the page being used
1981 * for !PFMEMALLOC purposes.
1983 page
->pfmemalloc
= !!(alloc_flags
& ALLOC_NO_WATERMARKS
);
1989 * Large machines with many possible nodes should not always dump per-node
1990 * meminfo in irq context.
1992 static inline bool should_suppress_show_mem(void)
1997 ret
= in_interrupt();
2002 static DEFINE_RATELIMIT_STATE(nopage_rs
,
2003 DEFAULT_RATELIMIT_INTERVAL
,
2004 DEFAULT_RATELIMIT_BURST
);
2006 void warn_alloc_failed(gfp_t gfp_mask
, int order
, const char *fmt
, ...)
2008 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
2010 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
2011 debug_guardpage_minorder() > 0)
2015 * This documents exceptions given to allocations in certain
2016 * contexts that are allowed to allocate outside current's set
2019 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2020 if (test_thread_flag(TIF_MEMDIE
) ||
2021 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
2022 filter
&= ~SHOW_MEM_FILTER_NODES
;
2023 if (in_interrupt() || !(gfp_mask
& __GFP_WAIT
))
2024 filter
&= ~SHOW_MEM_FILTER_NODES
;
2027 struct va_format vaf
;
2030 va_start(args
, fmt
);
2035 pr_warn("%pV", &vaf
);
2040 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
2041 current
->comm
, order
, gfp_mask
);
2044 if (!should_suppress_show_mem())
2049 should_alloc_retry(gfp_t gfp_mask
, unsigned int order
,
2050 unsigned long did_some_progress
,
2051 unsigned long pages_reclaimed
)
2053 /* Do not loop if specifically requested */
2054 if (gfp_mask
& __GFP_NORETRY
)
2057 /* Always retry if specifically requested */
2058 if (gfp_mask
& __GFP_NOFAIL
)
2062 * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
2063 * making forward progress without invoking OOM. Suspend also disables
2064 * storage devices so kswapd will not help. Bail if we are suspending.
2066 if (!did_some_progress
&& pm_suspended_storage())
2070 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
2071 * means __GFP_NOFAIL, but that may not be true in other
2074 if (order
<= PAGE_ALLOC_COSTLY_ORDER
)
2078 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
2079 * specified, then we retry until we no longer reclaim any pages
2080 * (above), or we've reclaimed an order of pages at least as
2081 * large as the allocation's order. In both cases, if the
2082 * allocation still fails, we stop retrying.
2084 if (gfp_mask
& __GFP_REPEAT
&& pages_reclaimed
< (1 << order
))
2090 static inline struct page
*
2091 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
2092 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2093 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2098 /* Acquire the OOM killer lock for the zones in zonelist */
2099 if (!try_set_zonelist_oom(zonelist
, gfp_mask
)) {
2100 schedule_timeout_uninterruptible(1);
2105 * Go through the zonelist yet one more time, keep very high watermark
2106 * here, this is only to catch a parallel oom killing, we must fail if
2107 * we're still under heavy pressure.
2109 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
,
2110 order
, zonelist
, high_zoneidx
,
2111 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
,
2112 preferred_zone
, migratetype
);
2116 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2117 /* The OOM killer will not help higher order allocs */
2118 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2120 /* The OOM killer does not needlessly kill tasks for lowmem */
2121 if (high_zoneidx
< ZONE_NORMAL
)
2124 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
2125 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
2126 * The caller should handle page allocation failure by itself if
2127 * it specifies __GFP_THISNODE.
2128 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
2130 if (gfp_mask
& __GFP_THISNODE
)
2133 /* Exhausted what can be done so it's blamo time */
2134 out_of_memory(zonelist
, gfp_mask
, order
, nodemask
, false);
2137 clear_zonelist_oom(zonelist
, gfp_mask
);
2141 #ifdef CONFIG_COMPACTION
2142 /* Try memory compaction for high-order allocations before reclaim */
2143 static struct page
*
2144 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2145 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2146 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2147 int migratetype
, bool sync_migration
,
2148 bool *contended_compaction
, bool *deferred_compaction
,
2149 unsigned long *did_some_progress
)
2151 struct page
*page
= NULL
;
2156 if (compaction_deferred(preferred_zone
, order
)) {
2157 *deferred_compaction
= true;
2161 current
->flags
|= PF_MEMALLOC
;
2162 *did_some_progress
= try_to_compact_pages(zonelist
, order
, gfp_mask
,
2163 nodemask
, sync_migration
,
2164 contended_compaction
, &page
);
2165 current
->flags
&= ~PF_MEMALLOC
;
2167 /* If compaction captured a page, prep and use it */
2169 prep_new_page(page
, order
, gfp_mask
);
2173 if (*did_some_progress
!= COMPACT_SKIPPED
) {
2174 /* Page migration frees to the PCP lists but we want merging */
2175 drain_pages(get_cpu());
2178 page
= get_page_from_freelist(gfp_mask
, nodemask
,
2179 order
, zonelist
, high_zoneidx
,
2180 alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2181 preferred_zone
, migratetype
);
2184 preferred_zone
->compact_blockskip_flush
= false;
2185 preferred_zone
->compact_considered
= 0;
2186 preferred_zone
->compact_defer_shift
= 0;
2187 if (order
>= preferred_zone
->compact_order_failed
)
2188 preferred_zone
->compact_order_failed
= order
+ 1;
2189 count_vm_event(COMPACTSUCCESS
);
2194 * It's bad if compaction run occurs and fails.
2195 * The most likely reason is that pages exist,
2196 * but not enough to satisfy watermarks.
2198 count_vm_event(COMPACTFAIL
);
2201 * As async compaction considers a subset of pageblocks, only
2202 * defer if the failure was a sync compaction failure.
2205 defer_compaction(preferred_zone
, order
);
2213 static inline struct page
*
2214 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2215 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2216 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2217 int migratetype
, bool sync_migration
,
2218 bool *contended_compaction
, bool *deferred_compaction
,
2219 unsigned long *did_some_progress
)
2223 #endif /* CONFIG_COMPACTION */
2225 /* Perform direct synchronous page reclaim */
2227 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
, struct zonelist
*zonelist
,
2228 nodemask_t
*nodemask
)
2230 struct reclaim_state reclaim_state
;
2235 /* We now go into synchronous reclaim */
2236 cpuset_memory_pressure_bump();
2237 current
->flags
|= PF_MEMALLOC
;
2238 lockdep_set_current_reclaim_state(gfp_mask
);
2239 reclaim_state
.reclaimed_slab
= 0;
2240 current
->reclaim_state
= &reclaim_state
;
2242 progress
= try_to_free_pages(zonelist
, order
, gfp_mask
, nodemask
);
2244 current
->reclaim_state
= NULL
;
2245 lockdep_clear_current_reclaim_state();
2246 current
->flags
&= ~PF_MEMALLOC
;
2253 /* The really slow allocator path where we enter direct reclaim */
2254 static inline struct page
*
2255 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
2256 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2257 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2258 int migratetype
, unsigned long *did_some_progress
)
2260 struct page
*page
= NULL
;
2261 bool drained
= false;
2263 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, zonelist
,
2265 if (unlikely(!(*did_some_progress
)))
2268 /* After successful reclaim, reconsider all zones for allocation */
2270 zlc_clear_zones_full(zonelist
);
2273 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
2274 zonelist
, high_zoneidx
,
2275 alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2276 preferred_zone
, migratetype
);
2279 * If an allocation failed after direct reclaim, it could be because
2280 * pages are pinned on the per-cpu lists. Drain them and try again
2282 if (!page
&& !drained
) {
2292 * This is called in the allocator slow-path if the allocation request is of
2293 * sufficient urgency to ignore watermarks and take other desperate measures
2295 static inline struct page
*
2296 __alloc_pages_high_priority(gfp_t gfp_mask
, unsigned int order
,
2297 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2298 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2304 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
2305 zonelist
, high_zoneidx
, ALLOC_NO_WATERMARKS
,
2306 preferred_zone
, migratetype
);
2308 if (!page
&& gfp_mask
& __GFP_NOFAIL
)
2309 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2310 } while (!page
&& (gfp_mask
& __GFP_NOFAIL
));
2316 void wake_all_kswapd(unsigned int order
, struct zonelist
*zonelist
,
2317 enum zone_type high_zoneidx
,
2318 enum zone_type classzone_idx
)
2323 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
)
2324 wakeup_kswapd(zone
, order
, classzone_idx
);
2328 gfp_to_alloc_flags(gfp_t gfp_mask
)
2330 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
2331 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2333 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2334 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
2337 * The caller may dip into page reserves a bit more if the caller
2338 * cannot run direct reclaim, or if the caller has realtime scheduling
2339 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2340 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
2342 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
2346 * Not worth trying to allocate harder for
2347 * __GFP_NOMEMALLOC even if it can't schedule.
2349 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2350 alloc_flags
|= ALLOC_HARDER
;
2352 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
2353 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
2355 alloc_flags
&= ~ALLOC_CPUSET
;
2356 } else if (unlikely(rt_task(current
)) && !in_interrupt())
2357 alloc_flags
|= ALLOC_HARDER
;
2359 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
2360 if (gfp_mask
& __GFP_MEMALLOC
)
2361 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2362 else if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
2363 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2364 else if (!in_interrupt() &&
2365 ((current
->flags
& PF_MEMALLOC
) ||
2366 unlikely(test_thread_flag(TIF_MEMDIE
))))
2367 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2370 if (allocflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
2371 alloc_flags
|= ALLOC_CMA
;
2376 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
2378 return !!(gfp_to_alloc_flags(gfp_mask
) & ALLOC_NO_WATERMARKS
);
2381 static inline struct page
*
2382 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
2383 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2384 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2387 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2388 struct page
*page
= NULL
;
2390 unsigned long pages_reclaimed
= 0;
2391 unsigned long did_some_progress
;
2392 bool sync_migration
= false;
2393 bool deferred_compaction
= false;
2394 bool contended_compaction
= false;
2397 * In the slowpath, we sanity check order to avoid ever trying to
2398 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2399 * be using allocators in order of preference for an area that is
2402 if (order
>= MAX_ORDER
) {
2403 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
2408 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
2409 * __GFP_NOWARN set) should not cause reclaim since the subsystem
2410 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
2411 * using a larger set of nodes after it has established that the
2412 * allowed per node queues are empty and that nodes are
2415 if (NUMA_BUILD
&& (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
2419 if (!(gfp_mask
& __GFP_NO_KSWAPD
))
2420 wake_all_kswapd(order
, zonelist
, high_zoneidx
,
2421 zone_idx(preferred_zone
));
2424 * OK, we're below the kswapd watermark and have kicked background
2425 * reclaim. Now things get more complex, so set up alloc_flags according
2426 * to how we want to proceed.
2428 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
2431 * Find the true preferred zone if the allocation is unconstrained by
2434 if (!(alloc_flags
& ALLOC_CPUSET
) && !nodemask
)
2435 first_zones_zonelist(zonelist
, high_zoneidx
, NULL
,
2439 /* This is the last chance, in general, before the goto nopage. */
2440 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
, zonelist
,
2441 high_zoneidx
, alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2442 preferred_zone
, migratetype
);
2446 /* Allocate without watermarks if the context allows */
2447 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
2449 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
2450 * the allocation is high priority and these type of
2451 * allocations are system rather than user orientated
2453 zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
2455 page
= __alloc_pages_high_priority(gfp_mask
, order
,
2456 zonelist
, high_zoneidx
, nodemask
,
2457 preferred_zone
, migratetype
);
2463 /* Atomic allocations - we can't balance anything */
2467 /* Avoid recursion of direct reclaim */
2468 if (current
->flags
& PF_MEMALLOC
)
2471 /* Avoid allocations with no watermarks from looping endlessly */
2472 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
2476 * Try direct compaction. The first pass is asynchronous. Subsequent
2477 * attempts after direct reclaim are synchronous
2479 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
2480 zonelist
, high_zoneidx
,
2482 alloc_flags
, preferred_zone
,
2483 migratetype
, sync_migration
,
2484 &contended_compaction
,
2485 &deferred_compaction
,
2486 &did_some_progress
);
2489 sync_migration
= true;
2492 * If compaction is deferred for high-order allocations, it is because
2493 * sync compaction recently failed. In this is the case and the caller
2494 * requested a movable allocation that does not heavily disrupt the
2495 * system then fail the allocation instead of entering direct reclaim.
2497 if ((deferred_compaction
|| contended_compaction
) &&
2498 (gfp_mask
& __GFP_NO_KSWAPD
))
2501 /* Try direct reclaim and then allocating */
2502 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
,
2503 zonelist
, high_zoneidx
,
2505 alloc_flags
, preferred_zone
,
2506 migratetype
, &did_some_progress
);
2511 * If we failed to make any progress reclaiming, then we are
2512 * running out of options and have to consider going OOM
2514 if (!did_some_progress
) {
2515 if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
2516 if (oom_killer_disabled
)
2518 /* Coredumps can quickly deplete all memory reserves */
2519 if ((current
->flags
& PF_DUMPCORE
) &&
2520 !(gfp_mask
& __GFP_NOFAIL
))
2522 page
= __alloc_pages_may_oom(gfp_mask
, order
,
2523 zonelist
, high_zoneidx
,
2524 nodemask
, preferred_zone
,
2529 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2531 * The oom killer is not called for high-order
2532 * allocations that may fail, so if no progress
2533 * is being made, there are no other options and
2534 * retrying is unlikely to help.
2536 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2539 * The oom killer is not called for lowmem
2540 * allocations to prevent needlessly killing
2543 if (high_zoneidx
< ZONE_NORMAL
)
2551 /* Check if we should retry the allocation */
2552 pages_reclaimed
+= did_some_progress
;
2553 if (should_alloc_retry(gfp_mask
, order
, did_some_progress
,
2555 /* Wait for some write requests to complete then retry */
2556 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2560 * High-order allocations do not necessarily loop after
2561 * direct reclaim and reclaim/compaction depends on compaction
2562 * being called after reclaim so call directly if necessary
2564 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
2565 zonelist
, high_zoneidx
,
2567 alloc_flags
, preferred_zone
,
2568 migratetype
, sync_migration
,
2569 &contended_compaction
,
2570 &deferred_compaction
,
2571 &did_some_progress
);
2577 warn_alloc_failed(gfp_mask
, order
, NULL
);
2580 if (kmemcheck_enabled
)
2581 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
2587 * This is the 'heart' of the zoned buddy allocator.
2590 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
2591 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
2593 enum zone_type high_zoneidx
= gfp_zone(gfp_mask
);
2594 struct zone
*preferred_zone
;
2595 struct page
*page
= NULL
;
2596 int migratetype
= allocflags_to_migratetype(gfp_mask
);
2597 unsigned int cpuset_mems_cookie
;
2598 int alloc_flags
= ALLOC_WMARK_LOW
|ALLOC_CPUSET
;
2600 gfp_mask
&= gfp_allowed_mask
;
2602 lockdep_trace_alloc(gfp_mask
);
2604 might_sleep_if(gfp_mask
& __GFP_WAIT
);
2606 if (should_fail_alloc_page(gfp_mask
, order
))
2610 * Check the zones suitable for the gfp_mask contain at least one
2611 * valid zone. It's possible to have an empty zonelist as a result
2612 * of GFP_THISNODE and a memoryless node
2614 if (unlikely(!zonelist
->_zonerefs
->zone
))
2618 cpuset_mems_cookie
= get_mems_allowed();
2620 /* The preferred zone is used for statistics later */
2621 first_zones_zonelist(zonelist
, high_zoneidx
,
2622 nodemask
? : &cpuset_current_mems_allowed
,
2624 if (!preferred_zone
)
2628 if (allocflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
2629 alloc_flags
|= ALLOC_CMA
;
2631 /* First allocation attempt */
2632 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
, order
,
2633 zonelist
, high_zoneidx
, alloc_flags
,
2634 preferred_zone
, migratetype
);
2635 if (unlikely(!page
))
2636 page
= __alloc_pages_slowpath(gfp_mask
, order
,
2637 zonelist
, high_zoneidx
, nodemask
,
2638 preferred_zone
, migratetype
);
2640 trace_mm_page_alloc(page
, order
, gfp_mask
, migratetype
);
2644 * When updating a task's mems_allowed, it is possible to race with
2645 * parallel threads in such a way that an allocation can fail while
2646 * the mask is being updated. If a page allocation is about to fail,
2647 * check if the cpuset changed during allocation and if so, retry.
2649 if (unlikely(!put_mems_allowed(cpuset_mems_cookie
) && !page
))
2654 EXPORT_SYMBOL(__alloc_pages_nodemask
);
2657 * Common helper functions.
2659 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
2664 * __get_free_pages() returns a 32-bit address, which cannot represent
2667 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
2669 page
= alloc_pages(gfp_mask
, order
);
2672 return (unsigned long) page_address(page
);
2674 EXPORT_SYMBOL(__get_free_pages
);
2676 unsigned long get_zeroed_page(gfp_t gfp_mask
)
2678 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
2680 EXPORT_SYMBOL(get_zeroed_page
);
2682 void __free_pages(struct page
*page
, unsigned int order
)
2684 if (put_page_testzero(page
)) {
2686 free_hot_cold_page(page
, 0);
2688 __free_pages_ok(page
, order
);
2692 EXPORT_SYMBOL(__free_pages
);
2694 void free_pages(unsigned long addr
, unsigned int order
)
2697 VM_BUG_ON(!virt_addr_valid((void *)addr
));
2698 __free_pages(virt_to_page((void *)addr
), order
);
2702 EXPORT_SYMBOL(free_pages
);
2704 static void *make_alloc_exact(unsigned long addr
, unsigned order
, size_t size
)
2707 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
2708 unsigned long used
= addr
+ PAGE_ALIGN(size
);
2710 split_page(virt_to_page((void *)addr
), order
);
2711 while (used
< alloc_end
) {
2716 return (void *)addr
;
2720 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2721 * @size: the number of bytes to allocate
2722 * @gfp_mask: GFP flags for the allocation
2724 * This function is similar to alloc_pages(), except that it allocates the
2725 * minimum number of pages to satisfy the request. alloc_pages() can only
2726 * allocate memory in power-of-two pages.
2728 * This function is also limited by MAX_ORDER.
2730 * Memory allocated by this function must be released by free_pages_exact().
2732 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
2734 unsigned int order
= get_order(size
);
2737 addr
= __get_free_pages(gfp_mask
, order
);
2738 return make_alloc_exact(addr
, order
, size
);
2740 EXPORT_SYMBOL(alloc_pages_exact
);
2743 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
2745 * @nid: the preferred node ID where memory should be allocated
2746 * @size: the number of bytes to allocate
2747 * @gfp_mask: GFP flags for the allocation
2749 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
2751 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
2754 void *alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
2756 unsigned order
= get_order(size
);
2757 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
2760 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
2762 EXPORT_SYMBOL(alloc_pages_exact_nid
);
2765 * free_pages_exact - release memory allocated via alloc_pages_exact()
2766 * @virt: the value returned by alloc_pages_exact.
2767 * @size: size of allocation, same value as passed to alloc_pages_exact().
2769 * Release the memory allocated by a previous call to alloc_pages_exact.
2771 void free_pages_exact(void *virt
, size_t size
)
2773 unsigned long addr
= (unsigned long)virt
;
2774 unsigned long end
= addr
+ PAGE_ALIGN(size
);
2776 while (addr
< end
) {
2781 EXPORT_SYMBOL(free_pages_exact
);
2783 static unsigned int nr_free_zone_pages(int offset
)
2788 /* Just pick one node, since fallback list is circular */
2789 unsigned int sum
= 0;
2791 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
2793 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
2794 unsigned long size
= zone
->present_pages
;
2795 unsigned long high
= high_wmark_pages(zone
);
2804 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
2806 unsigned int nr_free_buffer_pages(void)
2808 return nr_free_zone_pages(gfp_zone(GFP_USER
));
2810 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
2813 * Amount of free RAM allocatable within all zones
2815 unsigned int nr_free_pagecache_pages(void)
2817 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
2820 static inline void show_node(struct zone
*zone
)
2823 printk("Node %d ", zone_to_nid(zone
));
2826 void si_meminfo(struct sysinfo
*val
)
2828 val
->totalram
= totalram_pages
;
2830 val
->freeram
= global_page_state(NR_FREE_PAGES
);
2831 val
->bufferram
= nr_blockdev_pages();
2832 val
->totalhigh
= totalhigh_pages
;
2833 val
->freehigh
= nr_free_highpages();
2834 val
->mem_unit
= PAGE_SIZE
;
2837 EXPORT_SYMBOL(si_meminfo
);
2840 void si_meminfo_node(struct sysinfo
*val
, int nid
)
2842 pg_data_t
*pgdat
= NODE_DATA(nid
);
2844 val
->totalram
= pgdat
->node_present_pages
;
2845 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
2846 #ifdef CONFIG_HIGHMEM
2847 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
2848 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
2854 val
->mem_unit
= PAGE_SIZE
;
2859 * Determine whether the node should be displayed or not, depending on whether
2860 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
2862 bool skip_free_areas_node(unsigned int flags
, int nid
)
2865 unsigned int cpuset_mems_cookie
;
2867 if (!(flags
& SHOW_MEM_FILTER_NODES
))
2871 cpuset_mems_cookie
= get_mems_allowed();
2872 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
2873 } while (!put_mems_allowed(cpuset_mems_cookie
));
2878 #define K(x) ((x) << (PAGE_SHIFT-10))
2881 * Show free area list (used inside shift_scroll-lock stuff)
2882 * We also calculate the percentage fragmentation. We do this by counting the
2883 * memory on each free list with the exception of the first item on the list.
2884 * Suppresses nodes that are not allowed by current's cpuset if
2885 * SHOW_MEM_FILTER_NODES is passed.
2887 void show_free_areas(unsigned int filter
)
2892 for_each_populated_zone(zone
) {
2893 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
2896 printk("%s per-cpu:\n", zone
->name
);
2898 for_each_online_cpu(cpu
) {
2899 struct per_cpu_pageset
*pageset
;
2901 pageset
= per_cpu_ptr(zone
->pageset
, cpu
);
2903 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
2904 cpu
, pageset
->pcp
.high
,
2905 pageset
->pcp
.batch
, pageset
->pcp
.count
);
2909 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
2910 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
2912 " dirty:%lu writeback:%lu unstable:%lu\n"
2913 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2914 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
2916 global_page_state(NR_ACTIVE_ANON
),
2917 global_page_state(NR_INACTIVE_ANON
),
2918 global_page_state(NR_ISOLATED_ANON
),
2919 global_page_state(NR_ACTIVE_FILE
),
2920 global_page_state(NR_INACTIVE_FILE
),
2921 global_page_state(NR_ISOLATED_FILE
),
2922 global_page_state(NR_UNEVICTABLE
),
2923 global_page_state(NR_FILE_DIRTY
),
2924 global_page_state(NR_WRITEBACK
),
2925 global_page_state(NR_UNSTABLE_NFS
),
2926 global_page_state(NR_FREE_PAGES
),
2927 global_page_state(NR_SLAB_RECLAIMABLE
),
2928 global_page_state(NR_SLAB_UNRECLAIMABLE
),
2929 global_page_state(NR_FILE_MAPPED
),
2930 global_page_state(NR_SHMEM
),
2931 global_page_state(NR_PAGETABLE
),
2932 global_page_state(NR_BOUNCE
),
2933 global_page_state(NR_FREE_CMA_PAGES
));
2935 for_each_populated_zone(zone
) {
2938 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
2946 " active_anon:%lukB"
2947 " inactive_anon:%lukB"
2948 " active_file:%lukB"
2949 " inactive_file:%lukB"
2950 " unevictable:%lukB"
2951 " isolated(anon):%lukB"
2952 " isolated(file):%lukB"
2959 " slab_reclaimable:%lukB"
2960 " slab_unreclaimable:%lukB"
2961 " kernel_stack:%lukB"
2966 " writeback_tmp:%lukB"
2967 " pages_scanned:%lu"
2968 " all_unreclaimable? %s"
2971 K(zone_page_state(zone
, NR_FREE_PAGES
)),
2972 K(min_wmark_pages(zone
)),
2973 K(low_wmark_pages(zone
)),
2974 K(high_wmark_pages(zone
)),
2975 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
2976 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
2977 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
2978 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
2979 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
2980 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
2981 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
2982 K(zone
->present_pages
),
2983 K(zone_page_state(zone
, NR_MLOCK
)),
2984 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
2985 K(zone_page_state(zone
, NR_WRITEBACK
)),
2986 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
2987 K(zone_page_state(zone
, NR_SHMEM
)),
2988 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
2989 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
2990 zone_page_state(zone
, NR_KERNEL_STACK
) *
2992 K(zone_page_state(zone
, NR_PAGETABLE
)),
2993 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
2994 K(zone_page_state(zone
, NR_BOUNCE
)),
2995 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)),
2996 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
2997 zone
->pages_scanned
,
2998 (zone
->all_unreclaimable
? "yes" : "no")
3000 printk("lowmem_reserve[]:");
3001 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3002 printk(" %lu", zone
->lowmem_reserve
[i
]);
3006 for_each_populated_zone(zone
) {
3007 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
3009 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3012 printk("%s: ", zone
->name
);
3014 spin_lock_irqsave(&zone
->lock
, flags
);
3015 for (order
= 0; order
< MAX_ORDER
; order
++) {
3016 nr
[order
] = zone
->free_area
[order
].nr_free
;
3017 total
+= nr
[order
] << order
;
3019 spin_unlock_irqrestore(&zone
->lock
, flags
);
3020 for (order
= 0; order
< MAX_ORDER
; order
++)
3021 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
3022 printk("= %lukB\n", K(total
));
3025 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
3027 show_swap_cache_info();
3030 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
3032 zoneref
->zone
= zone
;
3033 zoneref
->zone_idx
= zone_idx(zone
);
3037 * Builds allocation fallback zone lists.
3039 * Add all populated zones of a node to the zonelist.
3041 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
3042 int nr_zones
, enum zone_type zone_type
)
3046 BUG_ON(zone_type
>= MAX_NR_ZONES
);
3051 zone
= pgdat
->node_zones
+ zone_type
;
3052 if (populated_zone(zone
)) {
3053 zoneref_set_zone(zone
,
3054 &zonelist
->_zonerefs
[nr_zones
++]);
3055 check_highest_zone(zone_type
);
3058 } while (zone_type
);
3065 * 0 = automatic detection of better ordering.
3066 * 1 = order by ([node] distance, -zonetype)
3067 * 2 = order by (-zonetype, [node] distance)
3069 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3070 * the same zonelist. So only NUMA can configure this param.
3072 #define ZONELIST_ORDER_DEFAULT 0
3073 #define ZONELIST_ORDER_NODE 1
3074 #define ZONELIST_ORDER_ZONE 2
3076 /* zonelist order in the kernel.
3077 * set_zonelist_order() will set this to NODE or ZONE.
3079 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3080 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
3084 /* The value user specified ....changed by config */
3085 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3086 /* string for sysctl */
3087 #define NUMA_ZONELIST_ORDER_LEN 16
3088 char numa_zonelist_order
[16] = "default";
3091 * interface for configure zonelist ordering.
3092 * command line option "numa_zonelist_order"
3093 * = "[dD]efault - default, automatic configuration.
3094 * = "[nN]ode - order by node locality, then by zone within node
3095 * = "[zZ]one - order by zone, then by locality within zone
3098 static int __parse_numa_zonelist_order(char *s
)
3100 if (*s
== 'd' || *s
== 'D') {
3101 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3102 } else if (*s
== 'n' || *s
== 'N') {
3103 user_zonelist_order
= ZONELIST_ORDER_NODE
;
3104 } else if (*s
== 'z' || *s
== 'Z') {
3105 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
3108 "Ignoring invalid numa_zonelist_order value: "
3115 static __init
int setup_numa_zonelist_order(char *s
)
3122 ret
= __parse_numa_zonelist_order(s
);
3124 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
3128 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
3131 * sysctl handler for numa_zonelist_order
3133 int numa_zonelist_order_handler(ctl_table
*table
, int write
,
3134 void __user
*buffer
, size_t *length
,
3137 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
3139 static DEFINE_MUTEX(zl_order_mutex
);
3141 mutex_lock(&zl_order_mutex
);
3143 strcpy(saved_string
, (char*)table
->data
);
3144 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
3148 int oldval
= user_zonelist_order
;
3149 if (__parse_numa_zonelist_order((char*)table
->data
)) {
3151 * bogus value. restore saved string
3153 strncpy((char*)table
->data
, saved_string
,
3154 NUMA_ZONELIST_ORDER_LEN
);
3155 user_zonelist_order
= oldval
;
3156 } else if (oldval
!= user_zonelist_order
) {
3157 mutex_lock(&zonelists_mutex
);
3158 build_all_zonelists(NULL
, NULL
);
3159 mutex_unlock(&zonelists_mutex
);
3163 mutex_unlock(&zl_order_mutex
);
3168 #define MAX_NODE_LOAD (nr_online_nodes)
3169 static int node_load
[MAX_NUMNODES
];
3172 * find_next_best_node - find the next node that should appear in a given node's fallback list
3173 * @node: node whose fallback list we're appending
3174 * @used_node_mask: nodemask_t of already used nodes
3176 * We use a number of factors to determine which is the next node that should
3177 * appear on a given node's fallback list. The node should not have appeared
3178 * already in @node's fallback list, and it should be the next closest node
3179 * according to the distance array (which contains arbitrary distance values
3180 * from each node to each node in the system), and should also prefer nodes
3181 * with no CPUs, since presumably they'll have very little allocation pressure
3182 * on them otherwise.
3183 * It returns -1 if no node is found.
3185 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
3188 int min_val
= INT_MAX
;
3190 const struct cpumask
*tmp
= cpumask_of_node(0);
3192 /* Use the local node if we haven't already */
3193 if (!node_isset(node
, *used_node_mask
)) {
3194 node_set(node
, *used_node_mask
);
3198 for_each_node_state(n
, N_HIGH_MEMORY
) {
3200 /* Don't want a node to appear more than once */
3201 if (node_isset(n
, *used_node_mask
))
3204 /* Use the distance array to find the distance */
3205 val
= node_distance(node
, n
);
3207 /* Penalize nodes under us ("prefer the next node") */
3210 /* Give preference to headless and unused nodes */
3211 tmp
= cpumask_of_node(n
);
3212 if (!cpumask_empty(tmp
))
3213 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
3215 /* Slight preference for less loaded node */
3216 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
3217 val
+= node_load
[n
];
3219 if (val
< min_val
) {
3226 node_set(best_node
, *used_node_mask
);
3233 * Build zonelists ordered by node and zones within node.
3234 * This results in maximum locality--normal zone overflows into local
3235 * DMA zone, if any--but risks exhausting DMA zone.
3237 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
3240 struct zonelist
*zonelist
;
3242 zonelist
= &pgdat
->node_zonelists
[0];
3243 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
3245 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3247 zonelist
->_zonerefs
[j
].zone
= NULL
;
3248 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3252 * Build gfp_thisnode zonelists
3254 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
3257 struct zonelist
*zonelist
;
3259 zonelist
= &pgdat
->node_zonelists
[1];
3260 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
3261 zonelist
->_zonerefs
[j
].zone
= NULL
;
3262 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3266 * Build zonelists ordered by zone and nodes within zones.
3267 * This results in conserving DMA zone[s] until all Normal memory is
3268 * exhausted, but results in overflowing to remote node while memory
3269 * may still exist in local DMA zone.
3271 static int node_order
[MAX_NUMNODES
];
3273 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
3276 int zone_type
; /* needs to be signed */
3278 struct zonelist
*zonelist
;
3280 zonelist
= &pgdat
->node_zonelists
[0];
3282 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
3283 for (j
= 0; j
< nr_nodes
; j
++) {
3284 node
= node_order
[j
];
3285 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
3286 if (populated_zone(z
)) {
3288 &zonelist
->_zonerefs
[pos
++]);
3289 check_highest_zone(zone_type
);
3293 zonelist
->_zonerefs
[pos
].zone
= NULL
;
3294 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
3297 static int default_zonelist_order(void)
3300 unsigned long low_kmem_size
,total_size
;
3304 * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
3305 * If they are really small and used heavily, the system can fall
3306 * into OOM very easily.
3307 * This function detect ZONE_DMA/DMA32 size and configures zone order.
3309 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
3312 for_each_online_node(nid
) {
3313 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
3314 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
3315 if (populated_zone(z
)) {
3316 if (zone_type
< ZONE_NORMAL
)
3317 low_kmem_size
+= z
->present_pages
;
3318 total_size
+= z
->present_pages
;
3319 } else if (zone_type
== ZONE_NORMAL
) {
3321 * If any node has only lowmem, then node order
3322 * is preferred to allow kernel allocations
3323 * locally; otherwise, they can easily infringe
3324 * on other nodes when there is an abundance of
3325 * lowmem available to allocate from.
3327 return ZONELIST_ORDER_NODE
;
3331 if (!low_kmem_size
|| /* there are no DMA area. */
3332 low_kmem_size
> total_size
/2) /* DMA/DMA32 is big. */
3333 return ZONELIST_ORDER_NODE
;
3335 * look into each node's config.
3336 * If there is a node whose DMA/DMA32 memory is very big area on
3337 * local memory, NODE_ORDER may be suitable.
3339 average_size
= total_size
/
3340 (nodes_weight(node_states
[N_HIGH_MEMORY
]) + 1);
3341 for_each_online_node(nid
) {
3344 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
3345 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
3346 if (populated_zone(z
)) {
3347 if (zone_type
< ZONE_NORMAL
)
3348 low_kmem_size
+= z
->present_pages
;
3349 total_size
+= z
->present_pages
;
3352 if (low_kmem_size
&&
3353 total_size
> average_size
&& /* ignore small node */
3354 low_kmem_size
> total_size
* 70/100)
3355 return ZONELIST_ORDER_NODE
;
3357 return ZONELIST_ORDER_ZONE
;
3360 static void set_zonelist_order(void)
3362 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
3363 current_zonelist_order
= default_zonelist_order();
3365 current_zonelist_order
= user_zonelist_order
;
3368 static void build_zonelists(pg_data_t
*pgdat
)
3372 nodemask_t used_mask
;
3373 int local_node
, prev_node
;
3374 struct zonelist
*zonelist
;
3375 int order
= current_zonelist_order
;
3377 /* initialize zonelists */
3378 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
3379 zonelist
= pgdat
->node_zonelists
+ i
;
3380 zonelist
->_zonerefs
[0].zone
= NULL
;
3381 zonelist
->_zonerefs
[0].zone_idx
= 0;
3384 /* NUMA-aware ordering of nodes */
3385 local_node
= pgdat
->node_id
;
3386 load
= nr_online_nodes
;
3387 prev_node
= local_node
;
3388 nodes_clear(used_mask
);
3390 memset(node_order
, 0, sizeof(node_order
));
3393 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
3395 * We don't want to pressure a particular node.
3396 * So adding penalty to the first node in same
3397 * distance group to make it round-robin.
3399 if (node_distance(local_node
, node
) !=
3400 node_distance(local_node
, prev_node
))
3401 node_load
[node
] = load
;
3405 if (order
== ZONELIST_ORDER_NODE
)
3406 build_zonelists_in_node_order(pgdat
, node
);
3408 node_order
[j
++] = node
; /* remember order */
3411 if (order
== ZONELIST_ORDER_ZONE
) {
3412 /* calculate node order -- i.e., DMA last! */
3413 build_zonelists_in_zone_order(pgdat
, j
);
3416 build_thisnode_zonelists(pgdat
);
3419 /* Construct the zonelist performance cache - see further mmzone.h */
3420 static void build_zonelist_cache(pg_data_t
*pgdat
)
3422 struct zonelist
*zonelist
;
3423 struct zonelist_cache
*zlc
;
3426 zonelist
= &pgdat
->node_zonelists
[0];
3427 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
3428 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
3429 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
3430 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
3433 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3435 * Return node id of node used for "local" allocations.
3436 * I.e., first node id of first zone in arg node's generic zonelist.
3437 * Used for initializing percpu 'numa_mem', which is used primarily
3438 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3440 int local_memory_node(int node
)
3444 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
3445 gfp_zone(GFP_KERNEL
),
3452 #else /* CONFIG_NUMA */
3454 static void set_zonelist_order(void)
3456 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
3459 static void build_zonelists(pg_data_t
*pgdat
)
3461 int node
, local_node
;
3463 struct zonelist
*zonelist
;
3465 local_node
= pgdat
->node_id
;
3467 zonelist
= &pgdat
->node_zonelists
[0];
3468 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
3471 * Now we build the zonelist so that it contains the zones
3472 * of all the other nodes.
3473 * We don't want to pressure a particular node, so when
3474 * building the zones for node N, we make sure that the
3475 * zones coming right after the local ones are those from
3476 * node N+1 (modulo N)
3478 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
3479 if (!node_online(node
))
3481 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3484 for (node
= 0; node
< local_node
; node
++) {
3485 if (!node_online(node
))
3487 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3491 zonelist
->_zonerefs
[j
].zone
= NULL
;
3492 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3495 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3496 static void build_zonelist_cache(pg_data_t
*pgdat
)
3498 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
3501 #endif /* CONFIG_NUMA */
3504 * Boot pageset table. One per cpu which is going to be used for all
3505 * zones and all nodes. The parameters will be set in such a way
3506 * that an item put on a list will immediately be handed over to
3507 * the buddy list. This is safe since pageset manipulation is done
3508 * with interrupts disabled.
3510 * The boot_pagesets must be kept even after bootup is complete for
3511 * unused processors and/or zones. They do play a role for bootstrapping
3512 * hotplugged processors.
3514 * zoneinfo_show() and maybe other functions do
3515 * not check if the processor is online before following the pageset pointer.
3516 * Other parts of the kernel may not check if the zone is available.
3518 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
3519 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
3520 static void setup_zone_pageset(struct zone
*zone
);
3523 * Global mutex to protect against size modification of zonelists
3524 * as well as to serialize pageset setup for the new populated zone.
3526 DEFINE_MUTEX(zonelists_mutex
);
3528 /* return values int ....just for stop_machine() */
3529 static int __build_all_zonelists(void *data
)
3533 pg_data_t
*self
= data
;
3536 memset(node_load
, 0, sizeof(node_load
));
3539 if (self
&& !node_online(self
->node_id
)) {
3540 build_zonelists(self
);
3541 build_zonelist_cache(self
);
3544 for_each_online_node(nid
) {
3545 pg_data_t
*pgdat
= NODE_DATA(nid
);
3547 build_zonelists(pgdat
);
3548 build_zonelist_cache(pgdat
);
3552 * Initialize the boot_pagesets that are going to be used
3553 * for bootstrapping processors. The real pagesets for
3554 * each zone will be allocated later when the per cpu
3555 * allocator is available.
3557 * boot_pagesets are used also for bootstrapping offline
3558 * cpus if the system is already booted because the pagesets
3559 * are needed to initialize allocators on a specific cpu too.
3560 * F.e. the percpu allocator needs the page allocator which
3561 * needs the percpu allocator in order to allocate its pagesets
3562 * (a chicken-egg dilemma).
3564 for_each_possible_cpu(cpu
) {
3565 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
3567 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3569 * We now know the "local memory node" for each node--
3570 * i.e., the node of the first zone in the generic zonelist.
3571 * Set up numa_mem percpu variable for on-line cpus. During
3572 * boot, only the boot cpu should be on-line; we'll init the
3573 * secondary cpus' numa_mem as they come on-line. During
3574 * node/memory hotplug, we'll fixup all on-line cpus.
3576 if (cpu_online(cpu
))
3577 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
3585 * Called with zonelists_mutex held always
3586 * unless system_state == SYSTEM_BOOTING.
3588 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
3590 set_zonelist_order();
3592 if (system_state
== SYSTEM_BOOTING
) {
3593 __build_all_zonelists(NULL
);
3594 mminit_verify_zonelist();
3595 cpuset_init_current_mems_allowed();
3597 /* we have to stop all cpus to guarantee there is no user
3599 #ifdef CONFIG_MEMORY_HOTPLUG
3601 setup_zone_pageset(zone
);
3603 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
3604 /* cpuset refresh routine should be here */
3606 vm_total_pages
= nr_free_pagecache_pages();
3608 * Disable grouping by mobility if the number of pages in the
3609 * system is too low to allow the mechanism to work. It would be
3610 * more accurate, but expensive to check per-zone. This check is
3611 * made on memory-hotadd so a system can start with mobility
3612 * disabled and enable it later
3614 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
3615 page_group_by_mobility_disabled
= 1;
3617 page_group_by_mobility_disabled
= 0;
3619 printk("Built %i zonelists in %s order, mobility grouping %s. "
3620 "Total pages: %ld\n",
3622 zonelist_order_name
[current_zonelist_order
],
3623 page_group_by_mobility_disabled
? "off" : "on",
3626 printk("Policy zone: %s\n", zone_names
[policy_zone
]);
3631 * Helper functions to size the waitqueue hash table.
3632 * Essentially these want to choose hash table sizes sufficiently
3633 * large so that collisions trying to wait on pages are rare.
3634 * But in fact, the number of active page waitqueues on typical
3635 * systems is ridiculously low, less than 200. So this is even
3636 * conservative, even though it seems large.
3638 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3639 * waitqueues, i.e. the size of the waitq table given the number of pages.
3641 #define PAGES_PER_WAITQUEUE 256
3643 #ifndef CONFIG_MEMORY_HOTPLUG
3644 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3646 unsigned long size
= 1;
3648 pages
/= PAGES_PER_WAITQUEUE
;
3650 while (size
< pages
)
3654 * Once we have dozens or even hundreds of threads sleeping
3655 * on IO we've got bigger problems than wait queue collision.
3656 * Limit the size of the wait table to a reasonable size.
3658 size
= min(size
, 4096UL);
3660 return max(size
, 4UL);
3664 * A zone's size might be changed by hot-add, so it is not possible to determine
3665 * a suitable size for its wait_table. So we use the maximum size now.
3667 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
3669 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
3670 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3671 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
3673 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3674 * or more by the traditional way. (See above). It equals:
3676 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
3677 * ia64(16K page size) : = ( 8G + 4M)byte.
3678 * powerpc (64K page size) : = (32G +16M)byte.
3680 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3687 * This is an integer logarithm so that shifts can be used later
3688 * to extract the more random high bits from the multiplicative
3689 * hash function before the remainder is taken.
3691 static inline unsigned long wait_table_bits(unsigned long size
)
3696 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
3699 * Check if a pageblock contains reserved pages
3701 static int pageblock_is_reserved(unsigned long start_pfn
, unsigned long end_pfn
)
3705 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
3706 if (!pfn_valid_within(pfn
) || PageReserved(pfn_to_page(pfn
)))
3713 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3714 * of blocks reserved is based on min_wmark_pages(zone). The memory within
3715 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3716 * higher will lead to a bigger reserve which will get freed as contiguous
3717 * blocks as reclaim kicks in
3719 static void setup_zone_migrate_reserve(struct zone
*zone
)
3721 unsigned long start_pfn
, pfn
, end_pfn
, block_end_pfn
;
3723 unsigned long block_migratetype
;
3727 * Get the start pfn, end pfn and the number of blocks to reserve
3728 * We have to be careful to be aligned to pageblock_nr_pages to
3729 * make sure that we always check pfn_valid for the first page in
3732 start_pfn
= zone
->zone_start_pfn
;
3733 end_pfn
= start_pfn
+ zone
->spanned_pages
;
3734 start_pfn
= roundup(start_pfn
, pageblock_nr_pages
);
3735 reserve
= roundup(min_wmark_pages(zone
), pageblock_nr_pages
) >>
3739 * Reserve blocks are generally in place to help high-order atomic
3740 * allocations that are short-lived. A min_free_kbytes value that
3741 * would result in more than 2 reserve blocks for atomic allocations
3742 * is assumed to be in place to help anti-fragmentation for the
3743 * future allocation of hugepages at runtime.
3745 reserve
= min(2, reserve
);
3747 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
3748 if (!pfn_valid(pfn
))
3750 page
= pfn_to_page(pfn
);
3752 /* Watch out for overlapping nodes */
3753 if (page_to_nid(page
) != zone_to_nid(zone
))
3756 block_migratetype
= get_pageblock_migratetype(page
);
3758 /* Only test what is necessary when the reserves are not met */
3761 * Blocks with reserved pages will never free, skip
3764 block_end_pfn
= min(pfn
+ pageblock_nr_pages
, end_pfn
);
3765 if (pageblock_is_reserved(pfn
, block_end_pfn
))
3768 /* If this block is reserved, account for it */
3769 if (block_migratetype
== MIGRATE_RESERVE
) {
3774 /* Suitable for reserving if this block is movable */
3775 if (block_migratetype
== MIGRATE_MOVABLE
) {
3776 set_pageblock_migratetype(page
,
3778 move_freepages_block(zone
, page
,
3786 * If the reserve is met and this is a previous reserved block,
3789 if (block_migratetype
== MIGRATE_RESERVE
) {
3790 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3791 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
3797 * Initially all pages are reserved - free ones are freed
3798 * up by free_all_bootmem() once the early boot process is
3799 * done. Non-atomic initialization, single-pass.
3801 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
3802 unsigned long start_pfn
, enum memmap_context context
)
3805 unsigned long end_pfn
= start_pfn
+ size
;
3809 if (highest_memmap_pfn
< end_pfn
- 1)
3810 highest_memmap_pfn
= end_pfn
- 1;
3812 z
= &NODE_DATA(nid
)->node_zones
[zone
];
3813 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
3815 * There can be holes in boot-time mem_map[]s
3816 * handed to this function. They do not
3817 * exist on hotplugged memory.
3819 if (context
== MEMMAP_EARLY
) {
3820 if (!early_pfn_valid(pfn
))
3822 if (!early_pfn_in_nid(pfn
, nid
))
3825 page
= pfn_to_page(pfn
);
3826 set_page_links(page
, zone
, nid
, pfn
);
3827 mminit_verify_page_links(page
, zone
, nid
, pfn
);
3828 init_page_count(page
);
3829 reset_page_mapcount(page
);
3830 SetPageReserved(page
);
3832 * Mark the block movable so that blocks are reserved for
3833 * movable at startup. This will force kernel allocations
3834 * to reserve their blocks rather than leaking throughout
3835 * the address space during boot when many long-lived
3836 * kernel allocations are made. Later some blocks near
3837 * the start are marked MIGRATE_RESERVE by
3838 * setup_zone_migrate_reserve()
3840 * bitmap is created for zone's valid pfn range. but memmap
3841 * can be created for invalid pages (for alignment)
3842 * check here not to call set_pageblock_migratetype() against
3845 if ((z
->zone_start_pfn
<= pfn
)
3846 && (pfn
< z
->zone_start_pfn
+ z
->spanned_pages
)
3847 && !(pfn
& (pageblock_nr_pages
- 1)))
3848 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3850 INIT_LIST_HEAD(&page
->lru
);
3851 #ifdef WANT_PAGE_VIRTUAL
3852 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
3853 if (!is_highmem_idx(zone
))
3854 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
3859 static void __meminit
zone_init_free_lists(struct zone
*zone
)
3862 for_each_migratetype_order(order
, t
) {
3863 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
3864 zone
->free_area
[order
].nr_free
= 0;
3868 #ifndef __HAVE_ARCH_MEMMAP_INIT
3869 #define memmap_init(size, nid, zone, start_pfn) \
3870 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
3873 static int __meminit
zone_batchsize(struct zone
*zone
)
3879 * The per-cpu-pages pools are set to around 1000th of the
3880 * size of the zone. But no more than 1/2 of a meg.
3882 * OK, so we don't know how big the cache is. So guess.
3884 batch
= zone
->present_pages
/ 1024;
3885 if (batch
* PAGE_SIZE
> 512 * 1024)
3886 batch
= (512 * 1024) / PAGE_SIZE
;
3887 batch
/= 4; /* We effectively *= 4 below */
3892 * Clamp the batch to a 2^n - 1 value. Having a power
3893 * of 2 value was found to be more likely to have
3894 * suboptimal cache aliasing properties in some cases.
3896 * For example if 2 tasks are alternately allocating
3897 * batches of pages, one task can end up with a lot
3898 * of pages of one half of the possible page colors
3899 * and the other with pages of the other colors.
3901 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
3906 /* The deferral and batching of frees should be suppressed under NOMMU
3909 * The problem is that NOMMU needs to be able to allocate large chunks
3910 * of contiguous memory as there's no hardware page translation to
3911 * assemble apparent contiguous memory from discontiguous pages.
3913 * Queueing large contiguous runs of pages for batching, however,
3914 * causes the pages to actually be freed in smaller chunks. As there
3915 * can be a significant delay between the individual batches being
3916 * recycled, this leads to the once large chunks of space being
3917 * fragmented and becoming unavailable for high-order allocations.
3923 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
3925 struct per_cpu_pages
*pcp
;
3928 memset(p
, 0, sizeof(*p
));
3932 pcp
->high
= 6 * batch
;
3933 pcp
->batch
= max(1UL, 1 * batch
);
3934 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
3935 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
3939 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
3940 * to the value high for the pageset p.
3943 static void setup_pagelist_highmark(struct per_cpu_pageset
*p
,
3946 struct per_cpu_pages
*pcp
;
3950 pcp
->batch
= max(1UL, high
/4);
3951 if ((high
/4) > (PAGE_SHIFT
* 8))
3952 pcp
->batch
= PAGE_SHIFT
* 8;
3955 static void __meminit
setup_zone_pageset(struct zone
*zone
)
3959 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
3961 for_each_possible_cpu(cpu
) {
3962 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
3964 setup_pageset(pcp
, zone_batchsize(zone
));
3966 if (percpu_pagelist_fraction
)
3967 setup_pagelist_highmark(pcp
,
3968 (zone
->present_pages
/
3969 percpu_pagelist_fraction
));
3974 * Allocate per cpu pagesets and initialize them.
3975 * Before this call only boot pagesets were available.
3977 void __init
setup_per_cpu_pageset(void)
3981 for_each_populated_zone(zone
)
3982 setup_zone_pageset(zone
);
3985 static noinline __init_refok
3986 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
3989 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
3993 * The per-page waitqueue mechanism uses hashed waitqueues
3996 zone
->wait_table_hash_nr_entries
=
3997 wait_table_hash_nr_entries(zone_size_pages
);
3998 zone
->wait_table_bits
=
3999 wait_table_bits(zone
->wait_table_hash_nr_entries
);
4000 alloc_size
= zone
->wait_table_hash_nr_entries
4001 * sizeof(wait_queue_head_t
);
4003 if (!slab_is_available()) {
4004 zone
->wait_table
= (wait_queue_head_t
*)
4005 alloc_bootmem_node_nopanic(pgdat
, alloc_size
);
4008 * This case means that a zone whose size was 0 gets new memory
4009 * via memory hot-add.
4010 * But it may be the case that a new node was hot-added. In
4011 * this case vmalloc() will not be able to use this new node's
4012 * memory - this wait_table must be initialized to use this new
4013 * node itself as well.
4014 * To use this new node's memory, further consideration will be
4017 zone
->wait_table
= vmalloc(alloc_size
);
4019 if (!zone
->wait_table
)
4022 for(i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
4023 init_waitqueue_head(zone
->wait_table
+ i
);
4028 static __meminit
void zone_pcp_init(struct zone
*zone
)
4031 * per cpu subsystem is not up at this point. The following code
4032 * relies on the ability of the linker to provide the
4033 * offset of a (static) per cpu variable into the per cpu area.
4035 zone
->pageset
= &boot_pageset
;
4037 if (zone
->present_pages
)
4038 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
4039 zone
->name
, zone
->present_pages
,
4040 zone_batchsize(zone
));
4043 int __meminit
init_currently_empty_zone(struct zone
*zone
,
4044 unsigned long zone_start_pfn
,
4046 enum memmap_context context
)
4048 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
4050 ret
= zone_wait_table_init(zone
, size
);
4053 pgdat
->nr_zones
= zone_idx(zone
) + 1;
4055 zone
->zone_start_pfn
= zone_start_pfn
;
4057 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
4058 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4060 (unsigned long)zone_idx(zone
),
4061 zone_start_pfn
, (zone_start_pfn
+ size
));
4063 zone_init_free_lists(zone
);
4068 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4069 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4071 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4072 * Architectures may implement their own version but if add_active_range()
4073 * was used and there are no special requirements, this is a convenient
4076 int __meminit
__early_pfn_to_nid(unsigned long pfn
)
4078 unsigned long start_pfn
, end_pfn
;
4081 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
4082 if (start_pfn
<= pfn
&& pfn
< end_pfn
)
4084 /* This is a memory hole */
4087 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4089 int __meminit
early_pfn_to_nid(unsigned long pfn
)
4093 nid
= __early_pfn_to_nid(pfn
);
4096 /* just returns 0 */
4100 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
4101 bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
4105 nid
= __early_pfn_to_nid(pfn
);
4106 if (nid
>= 0 && nid
!= node
)
4113 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
4114 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4115 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
4117 * If an architecture guarantees that all ranges registered with
4118 * add_active_ranges() contain no holes and may be freed, this
4119 * this function may be used instead of calling free_bootmem() manually.
4121 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
4123 unsigned long start_pfn
, end_pfn
;
4126 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
4127 start_pfn
= min(start_pfn
, max_low_pfn
);
4128 end_pfn
= min(end_pfn
, max_low_pfn
);
4130 if (start_pfn
< end_pfn
)
4131 free_bootmem_node(NODE_DATA(this_nid
),
4132 PFN_PHYS(start_pfn
),
4133 (end_pfn
- start_pfn
) << PAGE_SHIFT
);
4138 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4139 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4141 * If an architecture guarantees that all ranges registered with
4142 * add_active_ranges() contain no holes and may be freed, this
4143 * function may be used instead of calling memory_present() manually.
4145 void __init
sparse_memory_present_with_active_regions(int nid
)
4147 unsigned long start_pfn
, end_pfn
;
4150 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
4151 memory_present(this_nid
, start_pfn
, end_pfn
);
4155 * get_pfn_range_for_nid - Return the start and end page frames for a node
4156 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4157 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
4158 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
4160 * It returns the start and end page frame of a node based on information
4161 * provided by an arch calling add_active_range(). If called for a node
4162 * with no available memory, a warning is printed and the start and end
4165 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
4166 unsigned long *start_pfn
, unsigned long *end_pfn
)
4168 unsigned long this_start_pfn
, this_end_pfn
;
4174 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
4175 *start_pfn
= min(*start_pfn
, this_start_pfn
);
4176 *end_pfn
= max(*end_pfn
, this_end_pfn
);
4179 if (*start_pfn
== -1UL)
4184 * This finds a zone that can be used for ZONE_MOVABLE pages. The
4185 * assumption is made that zones within a node are ordered in monotonic
4186 * increasing memory addresses so that the "highest" populated zone is used
4188 static void __init
find_usable_zone_for_movable(void)
4191 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
4192 if (zone_index
== ZONE_MOVABLE
)
4195 if (arch_zone_highest_possible_pfn
[zone_index
] >
4196 arch_zone_lowest_possible_pfn
[zone_index
])
4200 VM_BUG_ON(zone_index
== -1);
4201 movable_zone
= zone_index
;
4205 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4206 * because it is sized independent of architecture. Unlike the other zones,
4207 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4208 * in each node depending on the size of each node and how evenly kernelcore
4209 * is distributed. This helper function adjusts the zone ranges
4210 * provided by the architecture for a given node by using the end of the
4211 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4212 * zones within a node are in order of monotonic increases memory addresses
4214 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
4215 unsigned long zone_type
,
4216 unsigned long node_start_pfn
,
4217 unsigned long node_end_pfn
,
4218 unsigned long *zone_start_pfn
,
4219 unsigned long *zone_end_pfn
)
4221 /* Only adjust if ZONE_MOVABLE is on this node */
4222 if (zone_movable_pfn
[nid
]) {
4223 /* Size ZONE_MOVABLE */
4224 if (zone_type
== ZONE_MOVABLE
) {
4225 *zone_start_pfn
= zone_movable_pfn
[nid
];
4226 *zone_end_pfn
= min(node_end_pfn
,
4227 arch_zone_highest_possible_pfn
[movable_zone
]);
4229 /* Adjust for ZONE_MOVABLE starting within this range */
4230 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
4231 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
4232 *zone_end_pfn
= zone_movable_pfn
[nid
];
4234 /* Check if this whole range is within ZONE_MOVABLE */
4235 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
4236 *zone_start_pfn
= *zone_end_pfn
;
4241 * Return the number of pages a zone spans in a node, including holes
4242 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4244 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4245 unsigned long zone_type
,
4246 unsigned long *ignored
)
4248 unsigned long node_start_pfn
, node_end_pfn
;
4249 unsigned long zone_start_pfn
, zone_end_pfn
;
4251 /* Get the start and end of the node and zone */
4252 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
4253 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
4254 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
4255 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4256 node_start_pfn
, node_end_pfn
,
4257 &zone_start_pfn
, &zone_end_pfn
);
4259 /* Check that this node has pages within the zone's required range */
4260 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
4263 /* Move the zone boundaries inside the node if necessary */
4264 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
4265 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
4267 /* Return the spanned pages */
4268 return zone_end_pfn
- zone_start_pfn
;
4272 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4273 * then all holes in the requested range will be accounted for.
4275 unsigned long __meminit
__absent_pages_in_range(int nid
,
4276 unsigned long range_start_pfn
,
4277 unsigned long range_end_pfn
)
4279 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
4280 unsigned long start_pfn
, end_pfn
;
4283 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
4284 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
4285 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
4286 nr_absent
-= end_pfn
- start_pfn
;
4292 * absent_pages_in_range - Return number of page frames in holes within a range
4293 * @start_pfn: The start PFN to start searching for holes
4294 * @end_pfn: The end PFN to stop searching for holes
4296 * It returns the number of pages frames in memory holes within a range.
4298 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
4299 unsigned long end_pfn
)
4301 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
4304 /* Return the number of page frames in holes in a zone on a node */
4305 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4306 unsigned long zone_type
,
4307 unsigned long *ignored
)
4309 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
4310 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
4311 unsigned long node_start_pfn
, node_end_pfn
;
4312 unsigned long zone_start_pfn
, zone_end_pfn
;
4314 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
4315 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
4316 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
4318 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4319 node_start_pfn
, node_end_pfn
,
4320 &zone_start_pfn
, &zone_end_pfn
);
4321 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
4324 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4325 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4326 unsigned long zone_type
,
4327 unsigned long *zones_size
)
4329 return zones_size
[zone_type
];
4332 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4333 unsigned long zone_type
,
4334 unsigned long *zholes_size
)
4339 return zholes_size
[zone_type
];
4342 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4344 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
4345 unsigned long *zones_size
, unsigned long *zholes_size
)
4347 unsigned long realtotalpages
, totalpages
= 0;
4350 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4351 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
4353 pgdat
->node_spanned_pages
= totalpages
;
4355 realtotalpages
= totalpages
;
4356 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4358 zone_absent_pages_in_node(pgdat
->node_id
, i
,
4360 pgdat
->node_present_pages
= realtotalpages
;
4361 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
4365 #ifndef CONFIG_SPARSEMEM
4367 * Calculate the size of the zone->blockflags rounded to an unsigned long
4368 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4369 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4370 * round what is now in bits to nearest long in bits, then return it in
4373 static unsigned long __init
usemap_size(unsigned long zonesize
)
4375 unsigned long usemapsize
;
4377 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
4378 usemapsize
= usemapsize
>> pageblock_order
;
4379 usemapsize
*= NR_PAGEBLOCK_BITS
;
4380 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
4382 return usemapsize
/ 8;
4385 static void __init
setup_usemap(struct pglist_data
*pgdat
,
4386 struct zone
*zone
, unsigned long zonesize
)
4388 unsigned long usemapsize
= usemap_size(zonesize
);
4389 zone
->pageblock_flags
= NULL
;
4391 zone
->pageblock_flags
= alloc_bootmem_node_nopanic(pgdat
,
4395 static inline void setup_usemap(struct pglist_data
*pgdat
,
4396 struct zone
*zone
, unsigned long zonesize
) {}
4397 #endif /* CONFIG_SPARSEMEM */
4399 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4401 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4402 void __init
set_pageblock_order(void)
4406 /* Check that pageblock_nr_pages has not already been setup */
4407 if (pageblock_order
)
4410 if (HPAGE_SHIFT
> PAGE_SHIFT
)
4411 order
= HUGETLB_PAGE_ORDER
;
4413 order
= MAX_ORDER
- 1;
4416 * Assume the largest contiguous order of interest is a huge page.
4417 * This value may be variable depending on boot parameters on IA64 and
4420 pageblock_order
= order
;
4422 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4425 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4426 * is unused as pageblock_order is set at compile-time. See
4427 * include/linux/pageblock-flags.h for the values of pageblock_order based on
4430 void __init
set_pageblock_order(void)
4434 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4437 * Set up the zone data structures:
4438 * - mark all pages reserved
4439 * - mark all memory queues empty
4440 * - clear the memory bitmaps
4442 * NOTE: pgdat should get zeroed by caller.
4444 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
,
4445 unsigned long *zones_size
, unsigned long *zholes_size
)
4448 int nid
= pgdat
->node_id
;
4449 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
4452 pgdat_resize_init(pgdat
);
4453 init_waitqueue_head(&pgdat
->kswapd_wait
);
4454 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
4455 pgdat_page_cgroup_init(pgdat
);
4457 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4458 struct zone
*zone
= pgdat
->node_zones
+ j
;
4459 unsigned long size
, realsize
, memmap_pages
;
4461 size
= zone_spanned_pages_in_node(nid
, j
, zones_size
);
4462 realsize
= size
- zone_absent_pages_in_node(nid
, j
,
4466 * Adjust realsize so that it accounts for how much memory
4467 * is used by this zone for memmap. This affects the watermark
4468 * and per-cpu initialisations
4471 PAGE_ALIGN(size
* sizeof(struct page
)) >> PAGE_SHIFT
;
4472 if (realsize
>= memmap_pages
) {
4473 realsize
-= memmap_pages
;
4476 " %s zone: %lu pages used for memmap\n",
4477 zone_names
[j
], memmap_pages
);
4480 " %s zone: %lu pages exceeds realsize %lu\n",
4481 zone_names
[j
], memmap_pages
, realsize
);
4483 /* Account for reserved pages */
4484 if (j
== 0 && realsize
> dma_reserve
) {
4485 realsize
-= dma_reserve
;
4486 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
4487 zone_names
[0], dma_reserve
);
4490 if (!is_highmem_idx(j
))
4491 nr_kernel_pages
+= realsize
;
4492 nr_all_pages
+= realsize
;
4494 zone
->spanned_pages
= size
;
4495 zone
->present_pages
= realsize
;
4498 zone
->min_unmapped_pages
= (realsize
*sysctl_min_unmapped_ratio
)
4500 zone
->min_slab_pages
= (realsize
* sysctl_min_slab_ratio
) / 100;
4502 zone
->name
= zone_names
[j
];
4503 spin_lock_init(&zone
->lock
);
4504 spin_lock_init(&zone
->lru_lock
);
4505 zone_seqlock_init(zone
);
4506 zone
->zone_pgdat
= pgdat
;
4508 zone_pcp_init(zone
);
4509 lruvec_init(&zone
->lruvec
);
4513 set_pageblock_order();
4514 setup_usemap(pgdat
, zone
, size
);
4515 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
4516 size
, MEMMAP_EARLY
);
4518 memmap_init(size
, nid
, j
, zone_start_pfn
);
4519 zone_start_pfn
+= size
;
4523 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
4525 /* Skip empty nodes */
4526 if (!pgdat
->node_spanned_pages
)
4529 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4530 /* ia64 gets its own node_mem_map, before this, without bootmem */
4531 if (!pgdat
->node_mem_map
) {
4532 unsigned long size
, start
, end
;
4536 * The zone's endpoints aren't required to be MAX_ORDER
4537 * aligned but the node_mem_map endpoints must be in order
4538 * for the buddy allocator to function correctly.
4540 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
4541 end
= pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
4542 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
4543 size
= (end
- start
) * sizeof(struct page
);
4544 map
= alloc_remap(pgdat
->node_id
, size
);
4546 map
= alloc_bootmem_node_nopanic(pgdat
, size
);
4547 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
4549 #ifndef CONFIG_NEED_MULTIPLE_NODES
4551 * With no DISCONTIG, the global mem_map is just set as node 0's
4553 if (pgdat
== NODE_DATA(0)) {
4554 mem_map
= NODE_DATA(0)->node_mem_map
;
4555 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4556 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
4557 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
4558 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4561 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4564 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
4565 unsigned long node_start_pfn
, unsigned long *zholes_size
)
4567 pg_data_t
*pgdat
= NODE_DATA(nid
);
4569 /* pg_data_t should be reset to zero when it's allocated */
4570 WARN_ON(pgdat
->nr_zones
|| pgdat
->classzone_idx
);
4572 pgdat
->node_id
= nid
;
4573 pgdat
->node_start_pfn
= node_start_pfn
;
4574 init_zone_allows_reclaim(nid
);
4575 calculate_node_totalpages(pgdat
, zones_size
, zholes_size
);
4577 alloc_node_mem_map(pgdat
);
4578 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4579 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
4580 nid
, (unsigned long)pgdat
,
4581 (unsigned long)pgdat
->node_mem_map
);
4584 free_area_init_core(pgdat
, zones_size
, zholes_size
);
4587 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4589 #if MAX_NUMNODES > 1
4591 * Figure out the number of possible node ids.
4593 static void __init
setup_nr_node_ids(void)
4596 unsigned int highest
= 0;
4598 for_each_node_mask(node
, node_possible_map
)
4600 nr_node_ids
= highest
+ 1;
4603 static inline void setup_nr_node_ids(void)
4609 * node_map_pfn_alignment - determine the maximum internode alignment
4611 * This function should be called after node map is populated and sorted.
4612 * It calculates the maximum power of two alignment which can distinguish
4615 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
4616 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
4617 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
4618 * shifted, 1GiB is enough and this function will indicate so.
4620 * This is used to test whether pfn -> nid mapping of the chosen memory
4621 * model has fine enough granularity to avoid incorrect mapping for the
4622 * populated node map.
4624 * Returns the determined alignment in pfn's. 0 if there is no alignment
4625 * requirement (single node).
4627 unsigned long __init
node_map_pfn_alignment(void)
4629 unsigned long accl_mask
= 0, last_end
= 0;
4630 unsigned long start
, end
, mask
;
4634 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
4635 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
4642 * Start with a mask granular enough to pin-point to the
4643 * start pfn and tick off bits one-by-one until it becomes
4644 * too coarse to separate the current node from the last.
4646 mask
= ~((1 << __ffs(start
)) - 1);
4647 while (mask
&& last_end
<= (start
& (mask
<< 1)))
4650 /* accumulate all internode masks */
4654 /* convert mask to number of pages */
4655 return ~accl_mask
+ 1;
4658 /* Find the lowest pfn for a node */
4659 static unsigned long __init
find_min_pfn_for_node(int nid
)
4661 unsigned long min_pfn
= ULONG_MAX
;
4662 unsigned long start_pfn
;
4665 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
4666 min_pfn
= min(min_pfn
, start_pfn
);
4668 if (min_pfn
== ULONG_MAX
) {
4670 "Could not find start_pfn for node %d\n", nid
);
4678 * find_min_pfn_with_active_regions - Find the minimum PFN registered
4680 * It returns the minimum PFN based on information provided via
4681 * add_active_range().
4683 unsigned long __init
find_min_pfn_with_active_regions(void)
4685 return find_min_pfn_for_node(MAX_NUMNODES
);
4689 * early_calculate_totalpages()
4690 * Sum pages in active regions for movable zone.
4691 * Populate N_HIGH_MEMORY for calculating usable_nodes.
4693 static unsigned long __init
early_calculate_totalpages(void)
4695 unsigned long totalpages
= 0;
4696 unsigned long start_pfn
, end_pfn
;
4699 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
4700 unsigned long pages
= end_pfn
- start_pfn
;
4702 totalpages
+= pages
;
4704 node_set_state(nid
, N_HIGH_MEMORY
);
4710 * Find the PFN the Movable zone begins in each node. Kernel memory
4711 * is spread evenly between nodes as long as the nodes have enough
4712 * memory. When they don't, some nodes will have more kernelcore than
4715 static void __init
find_zone_movable_pfns_for_nodes(void)
4718 unsigned long usable_startpfn
;
4719 unsigned long kernelcore_node
, kernelcore_remaining
;
4720 /* save the state before borrow the nodemask */
4721 nodemask_t saved_node_state
= node_states
[N_HIGH_MEMORY
];
4722 unsigned long totalpages
= early_calculate_totalpages();
4723 int usable_nodes
= nodes_weight(node_states
[N_HIGH_MEMORY
]);
4726 * If movablecore was specified, calculate what size of
4727 * kernelcore that corresponds so that memory usable for
4728 * any allocation type is evenly spread. If both kernelcore
4729 * and movablecore are specified, then the value of kernelcore
4730 * will be used for required_kernelcore if it's greater than
4731 * what movablecore would have allowed.
4733 if (required_movablecore
) {
4734 unsigned long corepages
;
4737 * Round-up so that ZONE_MOVABLE is at least as large as what
4738 * was requested by the user
4740 required_movablecore
=
4741 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
4742 corepages
= totalpages
- required_movablecore
;
4744 required_kernelcore
= max(required_kernelcore
, corepages
);
4747 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
4748 if (!required_kernelcore
)
4751 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
4752 find_usable_zone_for_movable();
4753 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
4756 /* Spread kernelcore memory as evenly as possible throughout nodes */
4757 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4758 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4759 unsigned long start_pfn
, end_pfn
;
4762 * Recalculate kernelcore_node if the division per node
4763 * now exceeds what is necessary to satisfy the requested
4764 * amount of memory for the kernel
4766 if (required_kernelcore
< kernelcore_node
)
4767 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4770 * As the map is walked, we track how much memory is usable
4771 * by the kernel using kernelcore_remaining. When it is
4772 * 0, the rest of the node is usable by ZONE_MOVABLE
4774 kernelcore_remaining
= kernelcore_node
;
4776 /* Go through each range of PFNs within this node */
4777 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
4778 unsigned long size_pages
;
4780 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
4781 if (start_pfn
>= end_pfn
)
4784 /* Account for what is only usable for kernelcore */
4785 if (start_pfn
< usable_startpfn
) {
4786 unsigned long kernel_pages
;
4787 kernel_pages
= min(end_pfn
, usable_startpfn
)
4790 kernelcore_remaining
-= min(kernel_pages
,
4791 kernelcore_remaining
);
4792 required_kernelcore
-= min(kernel_pages
,
4793 required_kernelcore
);
4795 /* Continue if range is now fully accounted */
4796 if (end_pfn
<= usable_startpfn
) {
4799 * Push zone_movable_pfn to the end so
4800 * that if we have to rebalance
4801 * kernelcore across nodes, we will
4802 * not double account here
4804 zone_movable_pfn
[nid
] = end_pfn
;
4807 start_pfn
= usable_startpfn
;
4811 * The usable PFN range for ZONE_MOVABLE is from
4812 * start_pfn->end_pfn. Calculate size_pages as the
4813 * number of pages used as kernelcore
4815 size_pages
= end_pfn
- start_pfn
;
4816 if (size_pages
> kernelcore_remaining
)
4817 size_pages
= kernelcore_remaining
;
4818 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
4821 * Some kernelcore has been met, update counts and
4822 * break if the kernelcore for this node has been
4825 required_kernelcore
-= min(required_kernelcore
,
4827 kernelcore_remaining
-= size_pages
;
4828 if (!kernelcore_remaining
)
4834 * If there is still required_kernelcore, we do another pass with one
4835 * less node in the count. This will push zone_movable_pfn[nid] further
4836 * along on the nodes that still have memory until kernelcore is
4840 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
4843 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
4844 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
4845 zone_movable_pfn
[nid
] =
4846 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
4849 /* restore the node_state */
4850 node_states
[N_HIGH_MEMORY
] = saved_node_state
;
4853 /* Any regular memory on that node ? */
4854 static void __init
check_for_regular_memory(pg_data_t
*pgdat
)
4856 #ifdef CONFIG_HIGHMEM
4857 enum zone_type zone_type
;
4859 for (zone_type
= 0; zone_type
<= ZONE_NORMAL
; zone_type
++) {
4860 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4861 if (zone
->present_pages
) {
4862 node_set_state(zone_to_nid(zone
), N_NORMAL_MEMORY
);
4870 * free_area_init_nodes - Initialise all pg_data_t and zone data
4871 * @max_zone_pfn: an array of max PFNs for each zone
4873 * This will call free_area_init_node() for each active node in the system.
4874 * Using the page ranges provided by add_active_range(), the size of each
4875 * zone in each node and their holes is calculated. If the maximum PFN
4876 * between two adjacent zones match, it is assumed that the zone is empty.
4877 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
4878 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
4879 * starts where the previous one ended. For example, ZONE_DMA32 starts
4880 * at arch_max_dma_pfn.
4882 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
4884 unsigned long start_pfn
, end_pfn
;
4887 /* Record where the zone boundaries are */
4888 memset(arch_zone_lowest_possible_pfn
, 0,
4889 sizeof(arch_zone_lowest_possible_pfn
));
4890 memset(arch_zone_highest_possible_pfn
, 0,
4891 sizeof(arch_zone_highest_possible_pfn
));
4892 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
4893 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
4894 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
4895 if (i
== ZONE_MOVABLE
)
4897 arch_zone_lowest_possible_pfn
[i
] =
4898 arch_zone_highest_possible_pfn
[i
-1];
4899 arch_zone_highest_possible_pfn
[i
] =
4900 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
4902 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
4903 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
4905 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
4906 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
4907 find_zone_movable_pfns_for_nodes();
4909 /* Print out the zone ranges */
4910 printk("Zone ranges:\n");
4911 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4912 if (i
== ZONE_MOVABLE
)
4914 printk(KERN_CONT
" %-8s ", zone_names
[i
]);
4915 if (arch_zone_lowest_possible_pfn
[i
] ==
4916 arch_zone_highest_possible_pfn
[i
])
4917 printk(KERN_CONT
"empty\n");
4919 printk(KERN_CONT
"[mem %0#10lx-%0#10lx]\n",
4920 arch_zone_lowest_possible_pfn
[i
] << PAGE_SHIFT
,
4921 (arch_zone_highest_possible_pfn
[i
]
4922 << PAGE_SHIFT
) - 1);
4925 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
4926 printk("Movable zone start for each node\n");
4927 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
4928 if (zone_movable_pfn
[i
])
4929 printk(" Node %d: %#010lx\n", i
,
4930 zone_movable_pfn
[i
] << PAGE_SHIFT
);
4933 /* Print out the early node map */
4934 printk("Early memory node ranges\n");
4935 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
4936 printk(" node %3d: [mem %#010lx-%#010lx]\n", nid
,
4937 start_pfn
<< PAGE_SHIFT
, (end_pfn
<< PAGE_SHIFT
) - 1);
4939 /* Initialise every node */
4940 mminit_verify_pageflags_layout();
4941 setup_nr_node_ids();
4942 for_each_online_node(nid
) {
4943 pg_data_t
*pgdat
= NODE_DATA(nid
);
4944 free_area_init_node(nid
, NULL
,
4945 find_min_pfn_for_node(nid
), NULL
);
4947 /* Any memory on that node */
4948 if (pgdat
->node_present_pages
)
4949 node_set_state(nid
, N_HIGH_MEMORY
);
4950 check_for_regular_memory(pgdat
);
4954 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
4956 unsigned long long coremem
;
4960 coremem
= memparse(p
, &p
);
4961 *core
= coremem
>> PAGE_SHIFT
;
4963 /* Paranoid check that UL is enough for the coremem value */
4964 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
4970 * kernelcore=size sets the amount of memory for use for allocations that
4971 * cannot be reclaimed or migrated.
4973 static int __init
cmdline_parse_kernelcore(char *p
)
4975 return cmdline_parse_core(p
, &required_kernelcore
);
4979 * movablecore=size sets the amount of memory for use for allocations that
4980 * can be reclaimed or migrated.
4982 static int __init
cmdline_parse_movablecore(char *p
)
4984 return cmdline_parse_core(p
, &required_movablecore
);
4987 early_param("kernelcore", cmdline_parse_kernelcore
);
4988 early_param("movablecore", cmdline_parse_movablecore
);
4990 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4993 * set_dma_reserve - set the specified number of pages reserved in the first zone
4994 * @new_dma_reserve: The number of pages to mark reserved
4996 * The per-cpu batchsize and zone watermarks are determined by present_pages.
4997 * In the DMA zone, a significant percentage may be consumed by kernel image
4998 * and other unfreeable allocations which can skew the watermarks badly. This
4999 * function may optionally be used to account for unfreeable pages in the
5000 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
5001 * smaller per-cpu batchsize.
5003 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
5005 dma_reserve
= new_dma_reserve
;
5008 void __init
free_area_init(unsigned long *zones_size
)
5010 free_area_init_node(0, zones_size
,
5011 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
5014 static int page_alloc_cpu_notify(struct notifier_block
*self
,
5015 unsigned long action
, void *hcpu
)
5017 int cpu
= (unsigned long)hcpu
;
5019 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
5020 lru_add_drain_cpu(cpu
);
5024 * Spill the event counters of the dead processor
5025 * into the current processors event counters.
5026 * This artificially elevates the count of the current
5029 vm_events_fold_cpu(cpu
);
5032 * Zero the differential counters of the dead processor
5033 * so that the vm statistics are consistent.
5035 * This is only okay since the processor is dead and cannot
5036 * race with what we are doing.
5038 refresh_cpu_vm_stats(cpu
);
5043 void __init
page_alloc_init(void)
5045 hotcpu_notifier(page_alloc_cpu_notify
, 0);
5049 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
5050 * or min_free_kbytes changes.
5052 static void calculate_totalreserve_pages(void)
5054 struct pglist_data
*pgdat
;
5055 unsigned long reserve_pages
= 0;
5056 enum zone_type i
, j
;
5058 for_each_online_pgdat(pgdat
) {
5059 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5060 struct zone
*zone
= pgdat
->node_zones
+ i
;
5061 unsigned long max
= 0;
5063 /* Find valid and maximum lowmem_reserve in the zone */
5064 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
5065 if (zone
->lowmem_reserve
[j
] > max
)
5066 max
= zone
->lowmem_reserve
[j
];
5069 /* we treat the high watermark as reserved pages. */
5070 max
+= high_wmark_pages(zone
);
5072 if (max
> zone
->present_pages
)
5073 max
= zone
->present_pages
;
5074 reserve_pages
+= max
;
5076 * Lowmem reserves are not available to
5077 * GFP_HIGHUSER page cache allocations and
5078 * kswapd tries to balance zones to their high
5079 * watermark. As a result, neither should be
5080 * regarded as dirtyable memory, to prevent a
5081 * situation where reclaim has to clean pages
5082 * in order to balance the zones.
5084 zone
->dirty_balance_reserve
= max
;
5087 dirty_balance_reserve
= reserve_pages
;
5088 totalreserve_pages
= reserve_pages
;
5092 * setup_per_zone_lowmem_reserve - called whenever
5093 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
5094 * has a correct pages reserved value, so an adequate number of
5095 * pages are left in the zone after a successful __alloc_pages().
5097 static void setup_per_zone_lowmem_reserve(void)
5099 struct pglist_data
*pgdat
;
5100 enum zone_type j
, idx
;
5102 for_each_online_pgdat(pgdat
) {
5103 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5104 struct zone
*zone
= pgdat
->node_zones
+ j
;
5105 unsigned long present_pages
= zone
->present_pages
;
5107 zone
->lowmem_reserve
[j
] = 0;
5111 struct zone
*lower_zone
;
5115 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
5116 sysctl_lowmem_reserve_ratio
[idx
] = 1;
5118 lower_zone
= pgdat
->node_zones
+ idx
;
5119 lower_zone
->lowmem_reserve
[j
] = present_pages
/
5120 sysctl_lowmem_reserve_ratio
[idx
];
5121 present_pages
+= lower_zone
->present_pages
;
5126 /* update totalreserve_pages */
5127 calculate_totalreserve_pages();
5130 static void __setup_per_zone_wmarks(void)
5132 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
5133 unsigned long lowmem_pages
= 0;
5135 unsigned long flags
;
5137 /* Calculate total number of !ZONE_HIGHMEM pages */
5138 for_each_zone(zone
) {
5139 if (!is_highmem(zone
))
5140 lowmem_pages
+= zone
->present_pages
;
5143 for_each_zone(zone
) {
5146 spin_lock_irqsave(&zone
->lock
, flags
);
5147 tmp
= (u64
)pages_min
* zone
->present_pages
;
5148 do_div(tmp
, lowmem_pages
);
5149 if (is_highmem(zone
)) {
5151 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
5152 * need highmem pages, so cap pages_min to a small
5155 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
5156 * deltas controls asynch page reclaim, and so should
5157 * not be capped for highmem.
5161 min_pages
= zone
->present_pages
/ 1024;
5162 if (min_pages
< SWAP_CLUSTER_MAX
)
5163 min_pages
= SWAP_CLUSTER_MAX
;
5164 if (min_pages
> 128)
5166 zone
->watermark
[WMARK_MIN
] = min_pages
;
5169 * If it's a lowmem zone, reserve a number of pages
5170 * proportionate to the zone's size.
5172 zone
->watermark
[WMARK_MIN
] = tmp
;
5175 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + (tmp
>> 2);
5176 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + (tmp
>> 1);
5178 zone
->watermark
[WMARK_MIN
] += cma_wmark_pages(zone
);
5179 zone
->watermark
[WMARK_LOW
] += cma_wmark_pages(zone
);
5180 zone
->watermark
[WMARK_HIGH
] += cma_wmark_pages(zone
);
5182 setup_zone_migrate_reserve(zone
);
5183 spin_unlock_irqrestore(&zone
->lock
, flags
);
5186 /* update totalreserve_pages */
5187 calculate_totalreserve_pages();
5191 * setup_per_zone_wmarks - called when min_free_kbytes changes
5192 * or when memory is hot-{added|removed}
5194 * Ensures that the watermark[min,low,high] values for each zone are set
5195 * correctly with respect to min_free_kbytes.
5197 void setup_per_zone_wmarks(void)
5199 mutex_lock(&zonelists_mutex
);
5200 __setup_per_zone_wmarks();
5201 mutex_unlock(&zonelists_mutex
);
5205 * The inactive anon list should be small enough that the VM never has to
5206 * do too much work, but large enough that each inactive page has a chance
5207 * to be referenced again before it is swapped out.
5209 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
5210 * INACTIVE_ANON pages on this zone's LRU, maintained by the
5211 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
5212 * the anonymous pages are kept on the inactive list.
5215 * memory ratio inactive anon
5216 * -------------------------------------
5225 static void __meminit
calculate_zone_inactive_ratio(struct zone
*zone
)
5227 unsigned int gb
, ratio
;
5229 /* Zone size in gigabytes */
5230 gb
= zone
->present_pages
>> (30 - PAGE_SHIFT
);
5232 ratio
= int_sqrt(10 * gb
);
5236 zone
->inactive_ratio
= ratio
;
5239 static void __meminit
setup_per_zone_inactive_ratio(void)
5244 calculate_zone_inactive_ratio(zone
);
5248 * Initialise min_free_kbytes.
5250 * For small machines we want it small (128k min). For large machines
5251 * we want it large (64MB max). But it is not linear, because network
5252 * bandwidth does not increase linearly with machine size. We use
5254 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5255 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
5271 int __meminit
init_per_zone_wmark_min(void)
5273 unsigned long lowmem_kbytes
;
5275 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
5277 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
5278 if (min_free_kbytes
< 128)
5279 min_free_kbytes
= 128;
5280 if (min_free_kbytes
> 65536)
5281 min_free_kbytes
= 65536;
5282 setup_per_zone_wmarks();
5283 refresh_zone_stat_thresholds();
5284 setup_per_zone_lowmem_reserve();
5285 setup_per_zone_inactive_ratio();
5288 module_init(init_per_zone_wmark_min
)
5291 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5292 * that we can call two helper functions whenever min_free_kbytes
5295 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
5296 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5298 proc_dointvec(table
, write
, buffer
, length
, ppos
);
5300 setup_per_zone_wmarks();
5305 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
5306 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5311 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5316 zone
->min_unmapped_pages
= (zone
->present_pages
*
5317 sysctl_min_unmapped_ratio
) / 100;
5321 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
5322 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5327 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5332 zone
->min_slab_pages
= (zone
->present_pages
*
5333 sysctl_min_slab_ratio
) / 100;
5339 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5340 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5341 * whenever sysctl_lowmem_reserve_ratio changes.
5343 * The reserve ratio obviously has absolutely no relation with the
5344 * minimum watermarks. The lowmem reserve ratio can only make sense
5345 * if in function of the boot time zone sizes.
5347 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
5348 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5350 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5351 setup_per_zone_lowmem_reserve();
5356 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5357 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
5358 * can have before it gets flushed back to buddy allocator.
5361 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
5362 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5368 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5369 if (!write
|| (ret
< 0))
5371 for_each_populated_zone(zone
) {
5372 for_each_possible_cpu(cpu
) {
5374 high
= zone
->present_pages
/ percpu_pagelist_fraction
;
5375 setup_pagelist_highmark(
5376 per_cpu_ptr(zone
->pageset
, cpu
), high
);
5382 int hashdist
= HASHDIST_DEFAULT
;
5385 static int __init
set_hashdist(char *str
)
5389 hashdist
= simple_strtoul(str
, &str
, 0);
5392 __setup("hashdist=", set_hashdist
);
5396 * allocate a large system hash table from bootmem
5397 * - it is assumed that the hash table must contain an exact power-of-2
5398 * quantity of entries
5399 * - limit is the number of hash buckets, not the total allocation size
5401 void *__init
alloc_large_system_hash(const char *tablename
,
5402 unsigned long bucketsize
,
5403 unsigned long numentries
,
5406 unsigned int *_hash_shift
,
5407 unsigned int *_hash_mask
,
5408 unsigned long low_limit
,
5409 unsigned long high_limit
)
5411 unsigned long long max
= high_limit
;
5412 unsigned long log2qty
, size
;
5415 /* allow the kernel cmdline to have a say */
5417 /* round applicable memory size up to nearest megabyte */
5418 numentries
= nr_kernel_pages
;
5419 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
5420 numentries
>>= 20 - PAGE_SHIFT
;
5421 numentries
<<= 20 - PAGE_SHIFT
;
5423 /* limit to 1 bucket per 2^scale bytes of low memory */
5424 if (scale
> PAGE_SHIFT
)
5425 numentries
>>= (scale
- PAGE_SHIFT
);
5427 numentries
<<= (PAGE_SHIFT
- scale
);
5429 /* Make sure we've got at least a 0-order allocation.. */
5430 if (unlikely(flags
& HASH_SMALL
)) {
5431 /* Makes no sense without HASH_EARLY */
5432 WARN_ON(!(flags
& HASH_EARLY
));
5433 if (!(numentries
>> *_hash_shift
)) {
5434 numentries
= 1UL << *_hash_shift
;
5435 BUG_ON(!numentries
);
5437 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
5438 numentries
= PAGE_SIZE
/ bucketsize
;
5440 numentries
= roundup_pow_of_two(numentries
);
5442 /* limit allocation size to 1/16 total memory by default */
5444 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
5445 do_div(max
, bucketsize
);
5447 max
= min(max
, 0x80000000ULL
);
5449 if (numentries
< low_limit
)
5450 numentries
= low_limit
;
5451 if (numentries
> max
)
5454 log2qty
= ilog2(numentries
);
5457 size
= bucketsize
<< log2qty
;
5458 if (flags
& HASH_EARLY
)
5459 table
= alloc_bootmem_nopanic(size
);
5461 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
5464 * If bucketsize is not a power-of-two, we may free
5465 * some pages at the end of hash table which
5466 * alloc_pages_exact() automatically does
5468 if (get_order(size
) < MAX_ORDER
) {
5469 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
5470 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
5473 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
5476 panic("Failed to allocate %s hash table\n", tablename
);
5478 printk(KERN_INFO
"%s hash table entries: %ld (order: %d, %lu bytes)\n",
5481 ilog2(size
) - PAGE_SHIFT
,
5485 *_hash_shift
= log2qty
;
5487 *_hash_mask
= (1 << log2qty
) - 1;
5492 /* Return a pointer to the bitmap storing bits affecting a block of pages */
5493 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
5496 #ifdef CONFIG_SPARSEMEM
5497 return __pfn_to_section(pfn
)->pageblock_flags
;
5499 return zone
->pageblock_flags
;
5500 #endif /* CONFIG_SPARSEMEM */
5503 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
5505 #ifdef CONFIG_SPARSEMEM
5506 pfn
&= (PAGES_PER_SECTION
-1);
5507 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5509 pfn
= pfn
- zone
->zone_start_pfn
;
5510 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5511 #endif /* CONFIG_SPARSEMEM */
5515 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5516 * @page: The page within the block of interest
5517 * @start_bitidx: The first bit of interest to retrieve
5518 * @end_bitidx: The last bit of interest
5519 * returns pageblock_bits flags
5521 unsigned long get_pageblock_flags_group(struct page
*page
,
5522 int start_bitidx
, int end_bitidx
)
5525 unsigned long *bitmap
;
5526 unsigned long pfn
, bitidx
;
5527 unsigned long flags
= 0;
5528 unsigned long value
= 1;
5530 zone
= page_zone(page
);
5531 pfn
= page_to_pfn(page
);
5532 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5533 bitidx
= pfn_to_bitidx(zone
, pfn
);
5535 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5536 if (test_bit(bitidx
+ start_bitidx
, bitmap
))
5543 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5544 * @page: The page within the block of interest
5545 * @start_bitidx: The first bit of interest
5546 * @end_bitidx: The last bit of interest
5547 * @flags: The flags to set
5549 void set_pageblock_flags_group(struct page
*page
, unsigned long flags
,
5550 int start_bitidx
, int end_bitidx
)
5553 unsigned long *bitmap
;
5554 unsigned long pfn
, bitidx
;
5555 unsigned long value
= 1;
5557 zone
= page_zone(page
);
5558 pfn
= page_to_pfn(page
);
5559 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5560 bitidx
= pfn_to_bitidx(zone
, pfn
);
5561 VM_BUG_ON(pfn
< zone
->zone_start_pfn
);
5562 VM_BUG_ON(pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
);
5564 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5566 __set_bit(bitidx
+ start_bitidx
, bitmap
);
5568 __clear_bit(bitidx
+ start_bitidx
, bitmap
);
5572 * This function checks whether pageblock includes unmovable pages or not.
5573 * If @count is not zero, it is okay to include less @count unmovable pages
5575 * PageLRU check wihtout isolation or lru_lock could race so that
5576 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
5577 * expect this function should be exact.
5579 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
)
5581 unsigned long pfn
, iter
, found
;
5585 * For avoiding noise data, lru_add_drain_all() should be called
5586 * If ZONE_MOVABLE, the zone never contains unmovable pages
5588 if (zone_idx(zone
) == ZONE_MOVABLE
)
5590 mt
= get_pageblock_migratetype(page
);
5591 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
5594 pfn
= page_to_pfn(page
);
5595 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
5596 unsigned long check
= pfn
+ iter
;
5598 if (!pfn_valid_within(check
))
5601 page
= pfn_to_page(check
);
5603 * We can't use page_count without pin a page
5604 * because another CPU can free compound page.
5605 * This check already skips compound tails of THP
5606 * because their page->_count is zero at all time.
5608 if (!atomic_read(&page
->_count
)) {
5609 if (PageBuddy(page
))
5610 iter
+= (1 << page_order(page
)) - 1;
5617 * If there are RECLAIMABLE pages, we need to check it.
5618 * But now, memory offline itself doesn't call shrink_slab()
5619 * and it still to be fixed.
5622 * If the page is not RAM, page_count()should be 0.
5623 * we don't need more check. This is an _used_ not-movable page.
5625 * The problematic thing here is PG_reserved pages. PG_reserved
5626 * is set to both of a memory hole page and a _used_ kernel
5635 bool is_pageblock_removable_nolock(struct page
*page
)
5641 * We have to be careful here because we are iterating over memory
5642 * sections which are not zone aware so we might end up outside of
5643 * the zone but still within the section.
5644 * We have to take care about the node as well. If the node is offline
5645 * its NODE_DATA will be NULL - see page_zone.
5647 if (!node_online(page_to_nid(page
)))
5650 zone
= page_zone(page
);
5651 pfn
= page_to_pfn(page
);
5652 if (zone
->zone_start_pfn
> pfn
||
5653 zone
->zone_start_pfn
+ zone
->spanned_pages
<= pfn
)
5656 return !has_unmovable_pages(zone
, page
, 0);
5661 static unsigned long pfn_max_align_down(unsigned long pfn
)
5663 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
5664 pageblock_nr_pages
) - 1);
5667 static unsigned long pfn_max_align_up(unsigned long pfn
)
5669 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
5670 pageblock_nr_pages
));
5673 /* [start, end) must belong to a single zone. */
5674 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
5675 unsigned long start
, unsigned long end
)
5677 /* This function is based on compact_zone() from compaction.c. */
5678 unsigned long nr_reclaimed
;
5679 unsigned long pfn
= start
;
5680 unsigned int tries
= 0;
5683 migrate_prep_local();
5685 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
5686 if (fatal_signal_pending(current
)) {
5691 if (list_empty(&cc
->migratepages
)) {
5692 cc
->nr_migratepages
= 0;
5693 pfn
= isolate_migratepages_range(cc
->zone
, cc
,
5700 } else if (++tries
== 5) {
5701 ret
= ret
< 0 ? ret
: -EBUSY
;
5705 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
5707 cc
->nr_migratepages
-= nr_reclaimed
;
5709 ret
= migrate_pages(&cc
->migratepages
,
5710 alloc_migrate_target
,
5711 0, false, MIGRATE_SYNC
);
5714 putback_lru_pages(&cc
->migratepages
);
5715 return ret
> 0 ? 0 : ret
;
5719 * Update zone's cma pages counter used for watermark level calculation.
5721 static inline void __update_cma_watermarks(struct zone
*zone
, int count
)
5723 unsigned long flags
;
5724 spin_lock_irqsave(&zone
->lock
, flags
);
5725 zone
->min_cma_pages
+= count
;
5726 spin_unlock_irqrestore(&zone
->lock
, flags
);
5727 setup_per_zone_wmarks();
5731 * Trigger memory pressure bump to reclaim some pages in order to be able to
5732 * allocate 'count' pages in single page units. Does similar work as
5733 *__alloc_pages_slowpath() function.
5735 static int __reclaim_pages(struct zone
*zone
, gfp_t gfp_mask
, int count
)
5737 enum zone_type high_zoneidx
= gfp_zone(gfp_mask
);
5738 struct zonelist
*zonelist
= node_zonelist(0, gfp_mask
);
5739 int did_some_progress
= 0;
5743 * Increase level of watermarks to force kswapd do his job
5744 * to stabilise at new watermark level.
5746 __update_cma_watermarks(zone
, count
);
5748 /* Obey watermarks as if the page was being allocated */
5749 while (!zone_watermark_ok(zone
, 0, low_wmark_pages(zone
), 0, 0)) {
5750 wake_all_kswapd(order
, zonelist
, high_zoneidx
, zone_idx(zone
));
5752 did_some_progress
= __perform_reclaim(gfp_mask
, order
, zonelist
,
5754 if (!did_some_progress
) {
5755 /* Exhausted what can be done so it's blamo time */
5756 out_of_memory(zonelist
, gfp_mask
, order
, NULL
, false);
5760 /* Restore original watermark levels. */
5761 __update_cma_watermarks(zone
, -count
);
5767 * alloc_contig_range() -- tries to allocate given range of pages
5768 * @start: start PFN to allocate
5769 * @end: one-past-the-last PFN to allocate
5770 * @migratetype: migratetype of the underlaying pageblocks (either
5771 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
5772 * in range must have the same migratetype and it must
5773 * be either of the two.
5775 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
5776 * aligned, however it's the caller's responsibility to guarantee that
5777 * we are the only thread that changes migrate type of pageblocks the
5780 * The PFN range must belong to a single zone.
5782 * Returns zero on success or negative error code. On success all
5783 * pages which PFN is in [start, end) are allocated for the caller and
5784 * need to be freed with free_contig_range().
5786 int alloc_contig_range(unsigned long start
, unsigned long end
,
5787 unsigned migratetype
)
5789 struct zone
*zone
= page_zone(pfn_to_page(start
));
5790 unsigned long outer_start
, outer_end
;
5793 struct compact_control cc
= {
5794 .nr_migratepages
= 0,
5796 .zone
= page_zone(pfn_to_page(start
)),
5798 .ignore_skip_hint
= true,
5800 INIT_LIST_HEAD(&cc
.migratepages
);
5803 * What we do here is we mark all pageblocks in range as
5804 * MIGRATE_ISOLATE. Because pageblock and max order pages may
5805 * have different sizes, and due to the way page allocator
5806 * work, we align the range to biggest of the two pages so
5807 * that page allocator won't try to merge buddies from
5808 * different pageblocks and change MIGRATE_ISOLATE to some
5809 * other migration type.
5811 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
5812 * migrate the pages from an unaligned range (ie. pages that
5813 * we are interested in). This will put all the pages in
5814 * range back to page allocator as MIGRATE_ISOLATE.
5816 * When this is done, we take the pages in range from page
5817 * allocator removing them from the buddy system. This way
5818 * page allocator will never consider using them.
5820 * This lets us mark the pageblocks back as
5821 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
5822 * aligned range but not in the unaligned, original range are
5823 * put back to page allocator so that buddy can use them.
5826 ret
= start_isolate_page_range(pfn_max_align_down(start
),
5827 pfn_max_align_up(end
), migratetype
);
5831 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
5836 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
5837 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
5838 * more, all pages in [start, end) are free in page allocator.
5839 * What we are going to do is to allocate all pages from
5840 * [start, end) (that is remove them from page allocator).
5842 * The only problem is that pages at the beginning and at the
5843 * end of interesting range may be not aligned with pages that
5844 * page allocator holds, ie. they can be part of higher order
5845 * pages. Because of this, we reserve the bigger range and
5846 * once this is done free the pages we are not interested in.
5848 * We don't have to hold zone->lock here because the pages are
5849 * isolated thus they won't get removed from buddy.
5852 lru_add_drain_all();
5856 outer_start
= start
;
5857 while (!PageBuddy(pfn_to_page(outer_start
))) {
5858 if (++order
>= MAX_ORDER
) {
5862 outer_start
&= ~0UL << order
;
5865 /* Make sure the range is really isolated. */
5866 if (test_pages_isolated(outer_start
, end
)) {
5867 pr_warn("alloc_contig_range test_pages_isolated(%lx, %lx) failed\n",
5874 * Reclaim enough pages to make sure that contiguous allocation
5875 * will not starve the system.
5877 __reclaim_pages(zone
, GFP_HIGHUSER_MOVABLE
, end
-start
);
5879 /* Grab isolated pages from freelists. */
5880 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
5886 /* Free head and tail (if any) */
5887 if (start
!= outer_start
)
5888 free_contig_range(outer_start
, start
- outer_start
);
5889 if (end
!= outer_end
)
5890 free_contig_range(end
, outer_end
- end
);
5893 undo_isolate_page_range(pfn_max_align_down(start
),
5894 pfn_max_align_up(end
), migratetype
);
5898 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
5900 for (; nr_pages
--; ++pfn
)
5901 __free_page(pfn_to_page(pfn
));
5905 #ifdef CONFIG_MEMORY_HOTPLUG
5906 static int __meminit
__zone_pcp_update(void *data
)
5908 struct zone
*zone
= data
;
5910 unsigned long batch
= zone_batchsize(zone
), flags
;
5912 for_each_possible_cpu(cpu
) {
5913 struct per_cpu_pageset
*pset
;
5914 struct per_cpu_pages
*pcp
;
5916 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
5919 local_irq_save(flags
);
5921 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
5922 drain_zonestat(zone
, pset
);
5923 setup_pageset(pset
, batch
);
5924 local_irq_restore(flags
);
5929 void __meminit
zone_pcp_update(struct zone
*zone
)
5931 stop_machine(__zone_pcp_update
, zone
, NULL
);
5935 #ifdef CONFIG_MEMORY_HOTREMOVE
5936 void zone_pcp_reset(struct zone
*zone
)
5938 unsigned long flags
;
5940 struct per_cpu_pageset
*pset
;
5942 /* avoid races with drain_pages() */
5943 local_irq_save(flags
);
5944 if (zone
->pageset
!= &boot_pageset
) {
5945 for_each_online_cpu(cpu
) {
5946 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
5947 drain_zonestat(zone
, pset
);
5949 free_percpu(zone
->pageset
);
5950 zone
->pageset
= &boot_pageset
;
5952 local_irq_restore(flags
);
5956 * All pages in the range must be isolated before calling this.
5959 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
5965 unsigned long flags
;
5966 /* find the first valid pfn */
5967 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
5972 zone
= page_zone(pfn_to_page(pfn
));
5973 spin_lock_irqsave(&zone
->lock
, flags
);
5975 while (pfn
< end_pfn
) {
5976 if (!pfn_valid(pfn
)) {
5980 page
= pfn_to_page(pfn
);
5981 BUG_ON(page_count(page
));
5982 BUG_ON(!PageBuddy(page
));
5983 order
= page_order(page
);
5984 #ifdef CONFIG_DEBUG_VM
5985 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
5986 pfn
, 1 << order
, end_pfn
);
5988 list_del(&page
->lru
);
5989 rmv_page_order(page
);
5990 zone
->free_area
[order
].nr_free
--;
5991 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
5993 for (i
= 0; i
< (1 << order
); i
++)
5994 SetPageReserved((page
+i
));
5995 pfn
+= (1 << order
);
5997 spin_unlock_irqrestore(&zone
->lock
, flags
);
6001 #ifdef CONFIG_MEMORY_FAILURE
6002 bool is_free_buddy_page(struct page
*page
)
6004 struct zone
*zone
= page_zone(page
);
6005 unsigned long pfn
= page_to_pfn(page
);
6006 unsigned long flags
;
6009 spin_lock_irqsave(&zone
->lock
, flags
);
6010 for (order
= 0; order
< MAX_ORDER
; order
++) {
6011 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
6013 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
6016 spin_unlock_irqrestore(&zone
->lock
, flags
);
6018 return order
< MAX_ORDER
;
6022 static const struct trace_print_flags pageflag_names
[] = {
6023 {1UL << PG_locked
, "locked" },
6024 {1UL << PG_error
, "error" },
6025 {1UL << PG_referenced
, "referenced" },
6026 {1UL << PG_uptodate
, "uptodate" },
6027 {1UL << PG_dirty
, "dirty" },
6028 {1UL << PG_lru
, "lru" },
6029 {1UL << PG_active
, "active" },
6030 {1UL << PG_slab
, "slab" },
6031 {1UL << PG_owner_priv_1
, "owner_priv_1" },
6032 {1UL << PG_arch_1
, "arch_1" },
6033 {1UL << PG_reserved
, "reserved" },
6034 {1UL << PG_private
, "private" },
6035 {1UL << PG_private_2
, "private_2" },
6036 {1UL << PG_writeback
, "writeback" },
6037 #ifdef CONFIG_PAGEFLAGS_EXTENDED
6038 {1UL << PG_head
, "head" },
6039 {1UL << PG_tail
, "tail" },
6041 {1UL << PG_compound
, "compound" },
6043 {1UL << PG_swapcache
, "swapcache" },
6044 {1UL << PG_mappedtodisk
, "mappedtodisk" },
6045 {1UL << PG_reclaim
, "reclaim" },
6046 {1UL << PG_swapbacked
, "swapbacked" },
6047 {1UL << PG_unevictable
, "unevictable" },
6049 {1UL << PG_mlocked
, "mlocked" },
6051 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
6052 {1UL << PG_uncached
, "uncached" },
6054 #ifdef CONFIG_MEMORY_FAILURE
6055 {1UL << PG_hwpoison
, "hwpoison" },
6057 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6058 {1UL << PG_compound_lock
, "compound_lock" },
6062 static void dump_page_flags(unsigned long flags
)
6064 const char *delim
= "";
6068 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names
) != __NR_PAGEFLAGS
);
6070 printk(KERN_ALERT
"page flags: %#lx(", flags
);
6072 /* remove zone id */
6073 flags
&= (1UL << NR_PAGEFLAGS
) - 1;
6075 for (i
= 0; i
< ARRAY_SIZE(pageflag_names
) && flags
; i
++) {
6077 mask
= pageflag_names
[i
].mask
;
6078 if ((flags
& mask
) != mask
)
6082 printk("%s%s", delim
, pageflag_names
[i
].name
);
6086 /* check for left over flags */
6088 printk("%s%#lx", delim
, flags
);
6093 void dump_page(struct page
*page
)
6096 "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
6097 page
, atomic_read(&page
->_count
), page_mapcount(page
),
6098 page
->mapping
, page
->index
);
6099 dump_page_flags(page
->flags
);
6100 mem_cgroup_print_bad_page(page
);