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/compiler.h>
25 #include <linux/kernel.h>
26 #include <linux/kmemcheck.h>
27 #include <linux/module.h>
28 #include <linux/suspend.h>
29 #include <linux/pagevec.h>
30 #include <linux/blkdev.h>
31 #include <linux/slab.h>
32 #include <linux/oom.h>
33 #include <linux/notifier.h>
34 #include <linux/topology.h>
35 #include <linux/sysctl.h>
36 #include <linux/cpu.h>
37 #include <linux/cpuset.h>
38 #include <linux/memory_hotplug.h>
39 #include <linux/nodemask.h>
40 #include <linux/vmalloc.h>
41 #include <linux/mempolicy.h>
42 #include <linux/stop_machine.h>
43 #include <linux/sort.h>
44 #include <linux/pfn.h>
45 #include <linux/backing-dev.h>
46 #include <linux/fault-inject.h>
47 #include <linux/page-isolation.h>
48 #include <linux/page_cgroup.h>
49 #include <linux/debugobjects.h>
50 #include <linux/kmemleak.h>
51 #include <trace/events/kmem.h>
53 #include <asm/tlbflush.h>
54 #include <asm/div64.h>
58 * Array of node states.
60 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
61 [N_POSSIBLE
] = NODE_MASK_ALL
,
62 [N_ONLINE
] = { { [0] = 1UL } },
64 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
66 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
68 [N_CPU
] = { { [0] = 1UL } },
71 EXPORT_SYMBOL(node_states
);
73 unsigned long totalram_pages __read_mostly
;
74 unsigned long totalreserve_pages __read_mostly
;
75 unsigned long highest_memmap_pfn __read_mostly
;
76 int percpu_pagelist_fraction
;
77 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
79 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
80 int pageblock_order __read_mostly
;
83 static void __free_pages_ok(struct page
*page
, unsigned int order
);
86 * results with 256, 32 in the lowmem_reserve sysctl:
87 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
88 * 1G machine -> (16M dma, 784M normal, 224M high)
89 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
90 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
91 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
93 * TBD: should special case ZONE_DMA32 machines here - in those we normally
94 * don't need any ZONE_NORMAL reservation
96 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
97 #ifdef CONFIG_ZONE_DMA
100 #ifdef CONFIG_ZONE_DMA32
103 #ifdef CONFIG_HIGHMEM
109 EXPORT_SYMBOL(totalram_pages
);
111 static char * const zone_names
[MAX_NR_ZONES
] = {
112 #ifdef CONFIG_ZONE_DMA
115 #ifdef CONFIG_ZONE_DMA32
119 #ifdef CONFIG_HIGHMEM
125 int min_free_kbytes
= 1024;
127 static unsigned long __meminitdata nr_kernel_pages
;
128 static unsigned long __meminitdata nr_all_pages
;
129 static unsigned long __meminitdata dma_reserve
;
131 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
133 * MAX_ACTIVE_REGIONS determines the maximum number of distinct
134 * ranges of memory (RAM) that may be registered with add_active_range().
135 * Ranges passed to add_active_range() will be merged if possible
136 * so the number of times add_active_range() can be called is
137 * related to the number of nodes and the number of holes
139 #ifdef CONFIG_MAX_ACTIVE_REGIONS
140 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */
141 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
143 #if MAX_NUMNODES >= 32
144 /* If there can be many nodes, allow up to 50 holes per node */
145 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
147 /* By default, allow up to 256 distinct regions */
148 #define MAX_ACTIVE_REGIONS 256
152 static struct node_active_region __meminitdata early_node_map
[MAX_ACTIVE_REGIONS
];
153 static int __meminitdata nr_nodemap_entries
;
154 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
155 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
156 static unsigned long __initdata required_kernelcore
;
157 static unsigned long __initdata required_movablecore
;
158 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
160 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
162 EXPORT_SYMBOL(movable_zone
);
163 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
166 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
167 int nr_online_nodes __read_mostly
= 1;
168 EXPORT_SYMBOL(nr_node_ids
);
169 EXPORT_SYMBOL(nr_online_nodes
);
172 int page_group_by_mobility_disabled __read_mostly
;
174 static void set_pageblock_migratetype(struct page
*page
, int migratetype
)
177 if (unlikely(page_group_by_mobility_disabled
))
178 migratetype
= MIGRATE_UNMOVABLE
;
180 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
181 PB_migrate
, PB_migrate_end
);
184 bool oom_killer_disabled __read_mostly
;
186 #ifdef CONFIG_DEBUG_VM
187 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
191 unsigned long pfn
= page_to_pfn(page
);
194 seq
= zone_span_seqbegin(zone
);
195 if (pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
197 else if (pfn
< zone
->zone_start_pfn
)
199 } while (zone_span_seqretry(zone
, seq
));
204 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
206 if (!pfn_valid_within(page_to_pfn(page
)))
208 if (zone
!= page_zone(page
))
214 * Temporary debugging check for pages not lying within a given zone.
216 static int bad_range(struct zone
*zone
, struct page
*page
)
218 if (page_outside_zone_boundaries(zone
, page
))
220 if (!page_is_consistent(zone
, page
))
226 static inline int bad_range(struct zone
*zone
, struct page
*page
)
232 static void bad_page(struct page
*page
)
234 static unsigned long resume
;
235 static unsigned long nr_shown
;
236 static unsigned long nr_unshown
;
239 * Allow a burst of 60 reports, then keep quiet for that minute;
240 * or allow a steady drip of one report per second.
242 if (nr_shown
== 60) {
243 if (time_before(jiffies
, resume
)) {
249 "BUG: Bad page state: %lu messages suppressed\n",
256 resume
= jiffies
+ 60 * HZ
;
258 printk(KERN_ALERT
"BUG: Bad page state in process %s pfn:%05lx\n",
259 current
->comm
, page_to_pfn(page
));
261 "page:%p flags:%p count:%d mapcount:%d mapping:%p index:%lx\n",
262 page
, (void *)page
->flags
, page_count(page
),
263 page_mapcount(page
), page
->mapping
, page
->index
);
267 /* Leave bad fields for debug, except PageBuddy could make trouble */
268 __ClearPageBuddy(page
);
269 add_taint(TAINT_BAD_PAGE
);
273 * Higher-order pages are called "compound pages". They are structured thusly:
275 * The first PAGE_SIZE page is called the "head page".
277 * The remaining PAGE_SIZE pages are called "tail pages".
279 * All pages have PG_compound set. All pages have their ->private pointing at
280 * the head page (even the head page has this).
282 * The first tail page's ->lru.next holds the address of the compound page's
283 * put_page() function. Its ->lru.prev holds the order of allocation.
284 * This usage means that zero-order pages may not be compound.
287 static void free_compound_page(struct page
*page
)
289 __free_pages_ok(page
, compound_order(page
));
292 void prep_compound_page(struct page
*page
, unsigned long order
)
295 int nr_pages
= 1 << order
;
297 set_compound_page_dtor(page
, free_compound_page
);
298 set_compound_order(page
, order
);
300 for (i
= 1; i
< nr_pages
; i
++) {
301 struct page
*p
= page
+ i
;
304 p
->first_page
= page
;
308 static int destroy_compound_page(struct page
*page
, unsigned long order
)
311 int nr_pages
= 1 << order
;
314 if (unlikely(compound_order(page
) != order
) ||
315 unlikely(!PageHead(page
))) {
320 __ClearPageHead(page
);
322 for (i
= 1; i
< nr_pages
; i
++) {
323 struct page
*p
= page
+ i
;
325 if (unlikely(!PageTail(p
) || (p
->first_page
!= page
))) {
335 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
340 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
341 * and __GFP_HIGHMEM from hard or soft interrupt context.
343 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
344 for (i
= 0; i
< (1 << order
); i
++)
345 clear_highpage(page
+ i
);
348 static inline void set_page_order(struct page
*page
, int order
)
350 set_page_private(page
, order
);
351 __SetPageBuddy(page
);
354 static inline void rmv_page_order(struct page
*page
)
356 __ClearPageBuddy(page
);
357 set_page_private(page
, 0);
361 * Locate the struct page for both the matching buddy in our
362 * pair (buddy1) and the combined O(n+1) page they form (page).
364 * 1) Any buddy B1 will have an order O twin B2 which satisfies
365 * the following equation:
367 * For example, if the starting buddy (buddy2) is #8 its order
369 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
371 * 2) Any buddy B will have an order O+1 parent P which
372 * satisfies the following equation:
375 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
377 static inline struct page
*
378 __page_find_buddy(struct page
*page
, unsigned long page_idx
, unsigned int order
)
380 unsigned long buddy_idx
= page_idx
^ (1 << order
);
382 return page
+ (buddy_idx
- page_idx
);
385 static inline unsigned long
386 __find_combined_index(unsigned long page_idx
, unsigned int order
)
388 return (page_idx
& ~(1 << order
));
392 * This function checks whether a page is free && is the buddy
393 * we can do coalesce a page and its buddy if
394 * (a) the buddy is not in a hole &&
395 * (b) the buddy is in the buddy system &&
396 * (c) a page and its buddy have the same order &&
397 * (d) a page and its buddy are in the same zone.
399 * For recording whether a page is in the buddy system, we use PG_buddy.
400 * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
402 * For recording page's order, we use page_private(page).
404 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
407 if (!pfn_valid_within(page_to_pfn(buddy
)))
410 if (page_zone_id(page
) != page_zone_id(buddy
))
413 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
414 VM_BUG_ON(page_count(buddy
) != 0);
421 * Freeing function for a buddy system allocator.
423 * The concept of a buddy system is to maintain direct-mapped table
424 * (containing bit values) for memory blocks of various "orders".
425 * The bottom level table contains the map for the smallest allocatable
426 * units of memory (here, pages), and each level above it describes
427 * pairs of units from the levels below, hence, "buddies".
428 * At a high level, all that happens here is marking the table entry
429 * at the bottom level available, and propagating the changes upward
430 * as necessary, plus some accounting needed to play nicely with other
431 * parts of the VM system.
432 * At each level, we keep a list of pages, which are heads of continuous
433 * free pages of length of (1 << order) and marked with PG_buddy. Page's
434 * order is recorded in page_private(page) field.
435 * So when we are allocating or freeing one, we can derive the state of the
436 * other. That is, if we allocate a small block, and both were
437 * free, the remainder of the region must be split into blocks.
438 * If a block is freed, and its buddy is also free, then this
439 * triggers coalescing into a block of larger size.
444 static inline void __free_one_page(struct page
*page
,
445 struct zone
*zone
, unsigned int order
,
448 unsigned long page_idx
;
450 if (unlikely(PageCompound(page
)))
451 if (unlikely(destroy_compound_page(page
, order
)))
454 VM_BUG_ON(migratetype
== -1);
456 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
458 VM_BUG_ON(page_idx
& ((1 << order
) - 1));
459 VM_BUG_ON(bad_range(zone
, page
));
461 while (order
< MAX_ORDER
-1) {
462 unsigned long combined_idx
;
465 buddy
= __page_find_buddy(page
, page_idx
, order
);
466 if (!page_is_buddy(page
, buddy
, order
))
469 /* Our buddy is free, merge with it and move up one order. */
470 list_del(&buddy
->lru
);
471 zone
->free_area
[order
].nr_free
--;
472 rmv_page_order(buddy
);
473 combined_idx
= __find_combined_index(page_idx
, order
);
474 page
= page
+ (combined_idx
- page_idx
);
475 page_idx
= combined_idx
;
478 set_page_order(page
, order
);
480 &zone
->free_area
[order
].free_list
[migratetype
]);
481 zone
->free_area
[order
].nr_free
++;
484 #ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT
486 * free_page_mlock() -- clean up attempts to free and mlocked() page.
487 * Page should not be on lru, so no need to fix that up.
488 * free_pages_check() will verify...
490 static inline void free_page_mlock(struct page
*page
)
492 __dec_zone_page_state(page
, NR_MLOCK
);
493 __count_vm_event(UNEVICTABLE_MLOCKFREED
);
496 static void free_page_mlock(struct page
*page
) { }
499 static inline int free_pages_check(struct page
*page
)
501 if (unlikely(page_mapcount(page
) |
502 (page
->mapping
!= NULL
) |
503 (atomic_read(&page
->_count
) != 0) |
504 (page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
))) {
508 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
509 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
514 * Frees a number of pages from the PCP lists
515 * Assumes all pages on list are in same zone, and of same order.
516 * count is the number of pages to free.
518 * If the zone was previously in an "all pages pinned" state then look to
519 * see if this freeing clears that state.
521 * And clear the zone's pages_scanned counter, to hold off the "all pages are
522 * pinned" detection logic.
524 static void free_pcppages_bulk(struct zone
*zone
, int count
,
525 struct per_cpu_pages
*pcp
)
530 spin_lock(&zone
->lock
);
531 zone_clear_flag(zone
, ZONE_ALL_UNRECLAIMABLE
);
532 zone
->pages_scanned
= 0;
534 __mod_zone_page_state(zone
, NR_FREE_PAGES
, count
);
537 struct list_head
*list
;
540 * Remove pages from lists in a round-robin fashion. A
541 * batch_free count is maintained that is incremented when an
542 * empty list is encountered. This is so more pages are freed
543 * off fuller lists instead of spinning excessively around empty
548 if (++migratetype
== MIGRATE_PCPTYPES
)
550 list
= &pcp
->lists
[migratetype
];
551 } while (list_empty(list
));
554 page
= list_entry(list
->prev
, struct page
, lru
);
555 /* must delete as __free_one_page list manipulates */
556 list_del(&page
->lru
);
557 __free_one_page(page
, zone
, 0, migratetype
);
558 trace_mm_page_pcpu_drain(page
, 0, migratetype
);
559 } while (--count
&& --batch_free
&& !list_empty(list
));
561 spin_unlock(&zone
->lock
);
564 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
,
567 spin_lock(&zone
->lock
);
568 zone_clear_flag(zone
, ZONE_ALL_UNRECLAIMABLE
);
569 zone
->pages_scanned
= 0;
571 __mod_zone_page_state(zone
, NR_FREE_PAGES
, 1 << order
);
572 __free_one_page(page
, zone
, order
, migratetype
);
573 spin_unlock(&zone
->lock
);
576 static void __free_pages_ok(struct page
*page
, unsigned int order
)
581 int wasMlocked
= __TestClearPageMlocked(page
);
583 kmemcheck_free_shadow(page
, order
);
585 for (i
= 0 ; i
< (1 << order
) ; ++i
)
586 bad
+= free_pages_check(page
+ i
);
590 if (!PageHighMem(page
)) {
591 debug_check_no_locks_freed(page_address(page
),PAGE_SIZE
<<order
);
592 debug_check_no_obj_freed(page_address(page
),
595 arch_free_page(page
, order
);
596 kernel_map_pages(page
, 1 << order
, 0);
598 local_irq_save(flags
);
599 if (unlikely(wasMlocked
))
600 free_page_mlock(page
);
601 __count_vm_events(PGFREE
, 1 << order
);
602 free_one_page(page_zone(page
), page
, order
,
603 get_pageblock_migratetype(page
));
604 local_irq_restore(flags
);
608 * permit the bootmem allocator to evade page validation on high-order frees
610 void __meminit
__free_pages_bootmem(struct page
*page
, unsigned int order
)
613 __ClearPageReserved(page
);
614 set_page_count(page
, 0);
615 set_page_refcounted(page
);
621 for (loop
= 0; loop
< BITS_PER_LONG
; loop
++) {
622 struct page
*p
= &page
[loop
];
624 if (loop
+ 1 < BITS_PER_LONG
)
626 __ClearPageReserved(p
);
627 set_page_count(p
, 0);
630 set_page_refcounted(page
);
631 __free_pages(page
, order
);
637 * The order of subdivision here is critical for the IO subsystem.
638 * Please do not alter this order without good reasons and regression
639 * testing. Specifically, as large blocks of memory are subdivided,
640 * the order in which smaller blocks are delivered depends on the order
641 * they're subdivided in this function. This is the primary factor
642 * influencing the order in which pages are delivered to the IO
643 * subsystem according to empirical testing, and this is also justified
644 * by considering the behavior of a buddy system containing a single
645 * large block of memory acted on by a series of small allocations.
646 * This behavior is a critical factor in sglist merging's success.
650 static inline void expand(struct zone
*zone
, struct page
*page
,
651 int low
, int high
, struct free_area
*area
,
654 unsigned long size
= 1 << high
;
660 VM_BUG_ON(bad_range(zone
, &page
[size
]));
661 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
663 set_page_order(&page
[size
], high
);
668 * This page is about to be returned from the page allocator
670 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
672 if (unlikely(page_mapcount(page
) |
673 (page
->mapping
!= NULL
) |
674 (atomic_read(&page
->_count
) != 0) |
675 (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
))) {
680 set_page_private(page
, 0);
681 set_page_refcounted(page
);
683 arch_alloc_page(page
, order
);
684 kernel_map_pages(page
, 1 << order
, 1);
686 if (gfp_flags
& __GFP_ZERO
)
687 prep_zero_page(page
, order
, gfp_flags
);
689 if (order
&& (gfp_flags
& __GFP_COMP
))
690 prep_compound_page(page
, order
);
696 * Go through the free lists for the given migratetype and remove
697 * the smallest available page from the freelists
700 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
703 unsigned int current_order
;
704 struct free_area
* area
;
707 /* Find a page of the appropriate size in the preferred list */
708 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
709 area
= &(zone
->free_area
[current_order
]);
710 if (list_empty(&area
->free_list
[migratetype
]))
713 page
= list_entry(area
->free_list
[migratetype
].next
,
715 list_del(&page
->lru
);
716 rmv_page_order(page
);
718 expand(zone
, page
, order
, current_order
, area
, migratetype
);
727 * This array describes the order lists are fallen back to when
728 * the free lists for the desirable migrate type are depleted
730 static int fallbacks
[MIGRATE_TYPES
][MIGRATE_TYPES
-1] = {
731 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
732 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
733 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
734 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
, MIGRATE_RESERVE
, MIGRATE_RESERVE
}, /* Never used */
738 * Move the free pages in a range to the free lists of the requested type.
739 * Note that start_page and end_pages are not aligned on a pageblock
740 * boundary. If alignment is required, use move_freepages_block()
742 static int move_freepages(struct zone
*zone
,
743 struct page
*start_page
, struct page
*end_page
,
750 #ifndef CONFIG_HOLES_IN_ZONE
752 * page_zone is not safe to call in this context when
753 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
754 * anyway as we check zone boundaries in move_freepages_block().
755 * Remove at a later date when no bug reports exist related to
756 * grouping pages by mobility
758 BUG_ON(page_zone(start_page
) != page_zone(end_page
));
761 for (page
= start_page
; page
<= end_page
;) {
762 /* Make sure we are not inadvertently changing nodes */
763 VM_BUG_ON(page_to_nid(page
) != zone_to_nid(zone
));
765 if (!pfn_valid_within(page_to_pfn(page
))) {
770 if (!PageBuddy(page
)) {
775 order
= page_order(page
);
776 list_del(&page
->lru
);
778 &zone
->free_area
[order
].free_list
[migratetype
]);
780 pages_moved
+= 1 << order
;
786 static int move_freepages_block(struct zone
*zone
, struct page
*page
,
789 unsigned long start_pfn
, end_pfn
;
790 struct page
*start_page
, *end_page
;
792 start_pfn
= page_to_pfn(page
);
793 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
794 start_page
= pfn_to_page(start_pfn
);
795 end_page
= start_page
+ pageblock_nr_pages
- 1;
796 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
798 /* Do not cross zone boundaries */
799 if (start_pfn
< zone
->zone_start_pfn
)
801 if (end_pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
804 return move_freepages(zone
, start_page
, end_page
, migratetype
);
807 static void change_pageblock_range(struct page
*pageblock_page
,
808 int start_order
, int migratetype
)
810 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
812 while (nr_pageblocks
--) {
813 set_pageblock_migratetype(pageblock_page
, migratetype
);
814 pageblock_page
+= pageblock_nr_pages
;
818 /* Remove an element from the buddy allocator from the fallback list */
819 static inline struct page
*
820 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
)
822 struct free_area
* area
;
827 /* Find the largest possible block of pages in the other list */
828 for (current_order
= MAX_ORDER
-1; current_order
>= order
;
830 for (i
= 0; i
< MIGRATE_TYPES
- 1; i
++) {
831 migratetype
= fallbacks
[start_migratetype
][i
];
833 /* MIGRATE_RESERVE handled later if necessary */
834 if (migratetype
== MIGRATE_RESERVE
)
837 area
= &(zone
->free_area
[current_order
]);
838 if (list_empty(&area
->free_list
[migratetype
]))
841 page
= list_entry(area
->free_list
[migratetype
].next
,
846 * If breaking a large block of pages, move all free
847 * pages to the preferred allocation list. If falling
848 * back for a reclaimable kernel allocation, be more
849 * agressive about taking ownership of free pages
851 if (unlikely(current_order
>= (pageblock_order
>> 1)) ||
852 start_migratetype
== MIGRATE_RECLAIMABLE
||
853 page_group_by_mobility_disabled
) {
855 pages
= move_freepages_block(zone
, page
,
858 /* Claim the whole block if over half of it is free */
859 if (pages
>= (1 << (pageblock_order
-1)) ||
860 page_group_by_mobility_disabled
)
861 set_pageblock_migratetype(page
,
864 migratetype
= start_migratetype
;
867 /* Remove the page from the freelists */
868 list_del(&page
->lru
);
869 rmv_page_order(page
);
871 /* Take ownership for orders >= pageblock_order */
872 if (current_order
>= pageblock_order
)
873 change_pageblock_range(page
, current_order
,
876 expand(zone
, page
, order
, current_order
, area
, migratetype
);
878 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
879 start_migratetype
, migratetype
);
889 * Do the hard work of removing an element from the buddy allocator.
890 * Call me with the zone->lock already held.
892 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
898 page
= __rmqueue_smallest(zone
, order
, migratetype
);
900 if (unlikely(!page
) && migratetype
!= MIGRATE_RESERVE
) {
901 page
= __rmqueue_fallback(zone
, order
, migratetype
);
904 * Use MIGRATE_RESERVE rather than fail an allocation. goto
905 * is used because __rmqueue_smallest is an inline function
906 * and we want just one call site
909 migratetype
= MIGRATE_RESERVE
;
914 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
919 * Obtain a specified number of elements from the buddy allocator, all under
920 * a single hold of the lock, for efficiency. Add them to the supplied list.
921 * Returns the number of new pages which were placed at *list.
923 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
924 unsigned long count
, struct list_head
*list
,
925 int migratetype
, int cold
)
929 spin_lock(&zone
->lock
);
930 for (i
= 0; i
< count
; ++i
) {
931 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
932 if (unlikely(page
== NULL
))
936 * Split buddy pages returned by expand() are received here
937 * in physical page order. The page is added to the callers and
938 * list and the list head then moves forward. From the callers
939 * perspective, the linked list is ordered by page number in
940 * some conditions. This is useful for IO devices that can
941 * merge IO requests if the physical pages are ordered
944 if (likely(cold
== 0))
945 list_add(&page
->lru
, list
);
947 list_add_tail(&page
->lru
, list
);
948 set_page_private(page
, migratetype
);
951 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
952 spin_unlock(&zone
->lock
);
958 * Called from the vmstat counter updater to drain pagesets of this
959 * currently executing processor on remote nodes after they have
962 * Note that this function must be called with the thread pinned to
963 * a single processor.
965 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
970 local_irq_save(flags
);
971 if (pcp
->count
>= pcp
->batch
)
972 to_drain
= pcp
->batch
;
974 to_drain
= pcp
->count
;
975 free_pcppages_bulk(zone
, to_drain
, pcp
);
976 pcp
->count
-= to_drain
;
977 local_irq_restore(flags
);
982 * Drain pages of the indicated processor.
984 * The processor must either be the current processor and the
985 * thread pinned to the current processor or a processor that
988 static void drain_pages(unsigned int cpu
)
993 for_each_populated_zone(zone
) {
994 struct per_cpu_pageset
*pset
;
995 struct per_cpu_pages
*pcp
;
997 pset
= zone_pcp(zone
, cpu
);
1000 local_irq_save(flags
);
1001 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1003 local_irq_restore(flags
);
1008 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1010 void drain_local_pages(void *arg
)
1012 drain_pages(smp_processor_id());
1016 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
1018 void drain_all_pages(void)
1020 on_each_cpu(drain_local_pages
, NULL
, 1);
1023 #ifdef CONFIG_HIBERNATION
1025 void mark_free_pages(struct zone
*zone
)
1027 unsigned long pfn
, max_zone_pfn
;
1028 unsigned long flags
;
1030 struct list_head
*curr
;
1032 if (!zone
->spanned_pages
)
1035 spin_lock_irqsave(&zone
->lock
, flags
);
1037 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
1038 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1039 if (pfn_valid(pfn
)) {
1040 struct page
*page
= pfn_to_page(pfn
);
1042 if (!swsusp_page_is_forbidden(page
))
1043 swsusp_unset_page_free(page
);
1046 for_each_migratetype_order(order
, t
) {
1047 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
1050 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
1051 for (i
= 0; i
< (1UL << order
); i
++)
1052 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
1055 spin_unlock_irqrestore(&zone
->lock
, flags
);
1057 #endif /* CONFIG_PM */
1060 * Free a 0-order page
1062 static void free_hot_cold_page(struct page
*page
, int cold
)
1064 struct zone
*zone
= page_zone(page
);
1065 struct per_cpu_pages
*pcp
;
1066 unsigned long flags
;
1068 int wasMlocked
= __TestClearPageMlocked(page
);
1070 kmemcheck_free_shadow(page
, 0);
1073 page
->mapping
= NULL
;
1074 if (free_pages_check(page
))
1077 if (!PageHighMem(page
)) {
1078 debug_check_no_locks_freed(page_address(page
), PAGE_SIZE
);
1079 debug_check_no_obj_freed(page_address(page
), PAGE_SIZE
);
1081 arch_free_page(page
, 0);
1082 kernel_map_pages(page
, 1, 0);
1084 pcp
= &zone_pcp(zone
, get_cpu())->pcp
;
1085 migratetype
= get_pageblock_migratetype(page
);
1086 set_page_private(page
, migratetype
);
1087 local_irq_save(flags
);
1088 if (unlikely(wasMlocked
))
1089 free_page_mlock(page
);
1090 __count_vm_event(PGFREE
);
1093 * We only track unmovable, reclaimable and movable on pcp lists.
1094 * Free ISOLATE pages back to the allocator because they are being
1095 * offlined but treat RESERVE as movable pages so we can get those
1096 * areas back if necessary. Otherwise, we may have to free
1097 * excessively into the page allocator
1099 if (migratetype
>= MIGRATE_PCPTYPES
) {
1100 if (unlikely(migratetype
== MIGRATE_ISOLATE
)) {
1101 free_one_page(zone
, page
, 0, migratetype
);
1104 migratetype
= MIGRATE_MOVABLE
;
1108 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
1110 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
1112 if (pcp
->count
>= pcp
->high
) {
1113 free_pcppages_bulk(zone
, pcp
->batch
, pcp
);
1114 pcp
->count
-= pcp
->batch
;
1118 local_irq_restore(flags
);
1122 void free_hot_page(struct page
*page
)
1124 trace_mm_page_free_direct(page
, 0);
1125 free_hot_cold_page(page
, 0);
1129 * split_page takes a non-compound higher-order page, and splits it into
1130 * n (1<<order) sub-pages: page[0..n]
1131 * Each sub-page must be freed individually.
1133 * Note: this is probably too low level an operation for use in drivers.
1134 * Please consult with lkml before using this in your driver.
1136 void split_page(struct page
*page
, unsigned int order
)
1140 VM_BUG_ON(PageCompound(page
));
1141 VM_BUG_ON(!page_count(page
));
1143 #ifdef CONFIG_KMEMCHECK
1145 * Split shadow pages too, because free(page[0]) would
1146 * otherwise free the whole shadow.
1148 if (kmemcheck_page_is_tracked(page
))
1149 split_page(virt_to_page(page
[0].shadow
), order
);
1152 for (i
= 1; i
< (1 << order
); i
++)
1153 set_page_refcounted(page
+ i
);
1157 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1158 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1162 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
1163 struct zone
*zone
, int order
, gfp_t gfp_flags
,
1166 unsigned long flags
;
1168 int cold
= !!(gfp_flags
& __GFP_COLD
);
1173 if (likely(order
== 0)) {
1174 struct per_cpu_pages
*pcp
;
1175 struct list_head
*list
;
1177 pcp
= &zone_pcp(zone
, cpu
)->pcp
;
1178 list
= &pcp
->lists
[migratetype
];
1179 local_irq_save(flags
);
1180 if (list_empty(list
)) {
1181 pcp
->count
+= rmqueue_bulk(zone
, 0,
1184 if (unlikely(list_empty(list
)))
1189 page
= list_entry(list
->prev
, struct page
, lru
);
1191 page
= list_entry(list
->next
, struct page
, lru
);
1193 list_del(&page
->lru
);
1196 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
1198 * __GFP_NOFAIL is not to be used in new code.
1200 * All __GFP_NOFAIL callers should be fixed so that they
1201 * properly detect and handle allocation failures.
1203 * We most definitely don't want callers attempting to
1204 * allocate greater than order-1 page units with
1207 WARN_ON_ONCE(order
> 1);
1209 spin_lock_irqsave(&zone
->lock
, flags
);
1210 page
= __rmqueue(zone
, order
, migratetype
);
1211 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(1 << order
));
1212 spin_unlock(&zone
->lock
);
1217 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
1218 zone_statistics(preferred_zone
, zone
);
1219 local_irq_restore(flags
);
1222 VM_BUG_ON(bad_range(zone
, page
));
1223 if (prep_new_page(page
, order
, gfp_flags
))
1228 local_irq_restore(flags
);
1233 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
1234 #define ALLOC_WMARK_MIN WMARK_MIN
1235 #define ALLOC_WMARK_LOW WMARK_LOW
1236 #define ALLOC_WMARK_HIGH WMARK_HIGH
1237 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
1239 /* Mask to get the watermark bits */
1240 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
1242 #define ALLOC_HARDER 0x10 /* try to alloc harder */
1243 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
1244 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
1246 #ifdef CONFIG_FAIL_PAGE_ALLOC
1248 static struct fail_page_alloc_attr
{
1249 struct fault_attr attr
;
1251 u32 ignore_gfp_highmem
;
1252 u32 ignore_gfp_wait
;
1255 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1257 struct dentry
*ignore_gfp_highmem_file
;
1258 struct dentry
*ignore_gfp_wait_file
;
1259 struct dentry
*min_order_file
;
1261 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1263 } fail_page_alloc
= {
1264 .attr
= FAULT_ATTR_INITIALIZER
,
1265 .ignore_gfp_wait
= 1,
1266 .ignore_gfp_highmem
= 1,
1270 static int __init
setup_fail_page_alloc(char *str
)
1272 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
1274 __setup("fail_page_alloc=", setup_fail_page_alloc
);
1276 static int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1278 if (order
< fail_page_alloc
.min_order
)
1280 if (gfp_mask
& __GFP_NOFAIL
)
1282 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
1284 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
1287 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
1290 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1292 static int __init
fail_page_alloc_debugfs(void)
1294 mode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
1298 err
= init_fault_attr_dentries(&fail_page_alloc
.attr
,
1302 dir
= fail_page_alloc
.attr
.dentries
.dir
;
1304 fail_page_alloc
.ignore_gfp_wait_file
=
1305 debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
1306 &fail_page_alloc
.ignore_gfp_wait
);
1308 fail_page_alloc
.ignore_gfp_highmem_file
=
1309 debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
1310 &fail_page_alloc
.ignore_gfp_highmem
);
1311 fail_page_alloc
.min_order_file
=
1312 debugfs_create_u32("min-order", mode
, dir
,
1313 &fail_page_alloc
.min_order
);
1315 if (!fail_page_alloc
.ignore_gfp_wait_file
||
1316 !fail_page_alloc
.ignore_gfp_highmem_file
||
1317 !fail_page_alloc
.min_order_file
) {
1319 debugfs_remove(fail_page_alloc
.ignore_gfp_wait_file
);
1320 debugfs_remove(fail_page_alloc
.ignore_gfp_highmem_file
);
1321 debugfs_remove(fail_page_alloc
.min_order_file
);
1322 cleanup_fault_attr_dentries(&fail_page_alloc
.attr
);
1328 late_initcall(fail_page_alloc_debugfs
);
1330 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1332 #else /* CONFIG_FAIL_PAGE_ALLOC */
1334 static inline int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1339 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1342 * Return 1 if free pages are above 'mark'. This takes into account the order
1343 * of the allocation.
1345 int zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1346 int classzone_idx
, int alloc_flags
)
1348 /* free_pages my go negative - that's OK */
1350 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
) - (1 << order
) + 1;
1353 if (alloc_flags
& ALLOC_HIGH
)
1355 if (alloc_flags
& ALLOC_HARDER
)
1358 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
1360 for (o
= 0; o
< order
; o
++) {
1361 /* At the next order, this order's pages become unavailable */
1362 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1364 /* Require fewer higher order pages to be free */
1367 if (free_pages
<= min
)
1375 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1376 * skip over zones that are not allowed by the cpuset, or that have
1377 * been recently (in last second) found to be nearly full. See further
1378 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1379 * that have to skip over a lot of full or unallowed zones.
1381 * If the zonelist cache is present in the passed in zonelist, then
1382 * returns a pointer to the allowed node mask (either the current
1383 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1385 * If the zonelist cache is not available for this zonelist, does
1386 * nothing and returns NULL.
1388 * If the fullzones BITMAP in the zonelist cache is stale (more than
1389 * a second since last zap'd) then we zap it out (clear its bits.)
1391 * We hold off even calling zlc_setup, until after we've checked the
1392 * first zone in the zonelist, on the theory that most allocations will
1393 * be satisfied from that first zone, so best to examine that zone as
1394 * quickly as we can.
1396 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1398 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1399 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1401 zlc
= zonelist
->zlcache_ptr
;
1405 if (time_after(jiffies
, zlc
->last_full_zap
+ HZ
)) {
1406 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1407 zlc
->last_full_zap
= jiffies
;
1410 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1411 &cpuset_current_mems_allowed
:
1412 &node_states
[N_HIGH_MEMORY
];
1413 return allowednodes
;
1417 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1418 * if it is worth looking at further for free memory:
1419 * 1) Check that the zone isn't thought to be full (doesn't have its
1420 * bit set in the zonelist_cache fullzones BITMAP).
1421 * 2) Check that the zones node (obtained from the zonelist_cache
1422 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1423 * Return true (non-zero) if zone is worth looking at further, or
1424 * else return false (zero) if it is not.
1426 * This check -ignores- the distinction between various watermarks,
1427 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1428 * found to be full for any variation of these watermarks, it will
1429 * be considered full for up to one second by all requests, unless
1430 * we are so low on memory on all allowed nodes that we are forced
1431 * into the second scan of the zonelist.
1433 * In the second scan we ignore this zonelist cache and exactly
1434 * apply the watermarks to all zones, even it is slower to do so.
1435 * We are low on memory in the second scan, and should leave no stone
1436 * unturned looking for a free page.
1438 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1439 nodemask_t
*allowednodes
)
1441 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1442 int i
; /* index of *z in zonelist zones */
1443 int n
; /* node that zone *z is on */
1445 zlc
= zonelist
->zlcache_ptr
;
1449 i
= z
- zonelist
->_zonerefs
;
1452 /* This zone is worth trying if it is allowed but not full */
1453 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1457 * Given 'z' scanning a zonelist, set the corresponding bit in
1458 * zlc->fullzones, so that subsequent attempts to allocate a page
1459 * from that zone don't waste time re-examining it.
1461 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1463 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1464 int i
; /* index of *z in zonelist zones */
1466 zlc
= zonelist
->zlcache_ptr
;
1470 i
= z
- zonelist
->_zonerefs
;
1472 set_bit(i
, zlc
->fullzones
);
1475 #else /* CONFIG_NUMA */
1477 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1482 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1483 nodemask_t
*allowednodes
)
1488 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1491 #endif /* CONFIG_NUMA */
1494 * get_page_from_freelist goes through the zonelist trying to allocate
1497 static struct page
*
1498 get_page_from_freelist(gfp_t gfp_mask
, nodemask_t
*nodemask
, unsigned int order
,
1499 struct zonelist
*zonelist
, int high_zoneidx
, int alloc_flags
,
1500 struct zone
*preferred_zone
, int migratetype
)
1503 struct page
*page
= NULL
;
1506 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1507 int zlc_active
= 0; /* set if using zonelist_cache */
1508 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1510 classzone_idx
= zone_idx(preferred_zone
);
1513 * Scan zonelist, looking for a zone with enough free.
1514 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1516 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
1517 high_zoneidx
, nodemask
) {
1518 if (NUMA_BUILD
&& zlc_active
&&
1519 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1521 if ((alloc_flags
& ALLOC_CPUSET
) &&
1522 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1525 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
1526 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
1530 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
1531 if (zone_watermark_ok(zone
, order
, mark
,
1532 classzone_idx
, alloc_flags
))
1535 if (zone_reclaim_mode
== 0)
1536 goto this_zone_full
;
1538 ret
= zone_reclaim(zone
, gfp_mask
, order
);
1540 case ZONE_RECLAIM_NOSCAN
:
1543 case ZONE_RECLAIM_FULL
:
1544 /* scanned but unreclaimable */
1545 goto this_zone_full
;
1547 /* did we reclaim enough */
1548 if (!zone_watermark_ok(zone
, order
, mark
,
1549 classzone_idx
, alloc_flags
))
1550 goto this_zone_full
;
1555 page
= buffered_rmqueue(preferred_zone
, zone
, order
,
1556 gfp_mask
, migratetype
);
1561 zlc_mark_zone_full(zonelist
, z
);
1563 if (NUMA_BUILD
&& !did_zlc_setup
&& nr_online_nodes
> 1) {
1565 * we do zlc_setup after the first zone is tried but only
1566 * if there are multiple nodes make it worthwhile
1568 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1574 if (unlikely(NUMA_BUILD
&& page
== NULL
&& zlc_active
)) {
1575 /* Disable zlc cache for second zonelist scan */
1583 should_alloc_retry(gfp_t gfp_mask
, unsigned int order
,
1584 unsigned long pages_reclaimed
)
1586 /* Do not loop if specifically requested */
1587 if (gfp_mask
& __GFP_NORETRY
)
1591 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
1592 * means __GFP_NOFAIL, but that may not be true in other
1595 if (order
<= PAGE_ALLOC_COSTLY_ORDER
)
1599 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
1600 * specified, then we retry until we no longer reclaim any pages
1601 * (above), or we've reclaimed an order of pages at least as
1602 * large as the allocation's order. In both cases, if the
1603 * allocation still fails, we stop retrying.
1605 if (gfp_mask
& __GFP_REPEAT
&& pages_reclaimed
< (1 << order
))
1609 * Don't let big-order allocations loop unless the caller
1610 * explicitly requests that.
1612 if (gfp_mask
& __GFP_NOFAIL
)
1618 static inline struct page
*
1619 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
1620 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1621 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
1626 /* Acquire the OOM killer lock for the zones in zonelist */
1627 if (!try_set_zone_oom(zonelist
, gfp_mask
)) {
1628 schedule_timeout_uninterruptible(1);
1633 * Go through the zonelist yet one more time, keep very high watermark
1634 * here, this is only to catch a parallel oom killing, we must fail if
1635 * we're still under heavy pressure.
1637 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
,
1638 order
, zonelist
, high_zoneidx
,
1639 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
,
1640 preferred_zone
, migratetype
);
1644 /* The OOM killer will not help higher order allocs */
1645 if (order
> PAGE_ALLOC_COSTLY_ORDER
&& !(gfp_mask
& __GFP_NOFAIL
))
1648 /* Exhausted what can be done so it's blamo time */
1649 out_of_memory(zonelist
, gfp_mask
, order
);
1652 clear_zonelist_oom(zonelist
, gfp_mask
);
1656 /* The really slow allocator path where we enter direct reclaim */
1657 static inline struct page
*
1658 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
1659 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1660 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
1661 int migratetype
, unsigned long *did_some_progress
)
1663 struct page
*page
= NULL
;
1664 struct reclaim_state reclaim_state
;
1665 struct task_struct
*p
= current
;
1669 /* We now go into synchronous reclaim */
1670 cpuset_memory_pressure_bump();
1671 p
->flags
|= PF_MEMALLOC
;
1672 lockdep_set_current_reclaim_state(gfp_mask
);
1673 reclaim_state
.reclaimed_slab
= 0;
1674 p
->reclaim_state
= &reclaim_state
;
1676 *did_some_progress
= try_to_free_pages(zonelist
, order
, gfp_mask
, nodemask
);
1678 p
->reclaim_state
= NULL
;
1679 lockdep_clear_current_reclaim_state();
1680 p
->flags
&= ~PF_MEMALLOC
;
1687 if (likely(*did_some_progress
))
1688 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
1689 zonelist
, high_zoneidx
,
1690 alloc_flags
, preferred_zone
,
1696 * This is called in the allocator slow-path if the allocation request is of
1697 * sufficient urgency to ignore watermarks and take other desperate measures
1699 static inline struct page
*
1700 __alloc_pages_high_priority(gfp_t gfp_mask
, unsigned int order
,
1701 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1702 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
1708 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
1709 zonelist
, high_zoneidx
, ALLOC_NO_WATERMARKS
,
1710 preferred_zone
, migratetype
);
1712 if (!page
&& gfp_mask
& __GFP_NOFAIL
)
1713 congestion_wait(BLK_RW_ASYNC
, HZ
/50);
1714 } while (!page
&& (gfp_mask
& __GFP_NOFAIL
));
1720 void wake_all_kswapd(unsigned int order
, struct zonelist
*zonelist
,
1721 enum zone_type high_zoneidx
)
1726 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
)
1727 wakeup_kswapd(zone
, order
);
1731 gfp_to_alloc_flags(gfp_t gfp_mask
)
1733 struct task_struct
*p
= current
;
1734 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
1735 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
1737 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
1738 BUILD_BUG_ON(__GFP_HIGH
!= ALLOC_HIGH
);
1741 * The caller may dip into page reserves a bit more if the caller
1742 * cannot run direct reclaim, or if the caller has realtime scheduling
1743 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
1744 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1746 alloc_flags
|= (gfp_mask
& __GFP_HIGH
);
1749 alloc_flags
|= ALLOC_HARDER
;
1751 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1752 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1754 alloc_flags
&= ~ALLOC_CPUSET
;
1755 } else if (unlikely(rt_task(p
)))
1756 alloc_flags
|= ALLOC_HARDER
;
1758 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
1759 if (!in_interrupt() &&
1760 ((p
->flags
& PF_MEMALLOC
) ||
1761 unlikely(test_thread_flag(TIF_MEMDIE
))))
1762 alloc_flags
|= ALLOC_NO_WATERMARKS
;
1768 static inline struct page
*
1769 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
1770 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1771 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
1774 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
1775 struct page
*page
= NULL
;
1777 unsigned long pages_reclaimed
= 0;
1778 unsigned long did_some_progress
;
1779 struct task_struct
*p
= current
;
1782 * In the slowpath, we sanity check order to avoid ever trying to
1783 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
1784 * be using allocators in order of preference for an area that is
1787 if (order
>= MAX_ORDER
) {
1788 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
1793 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
1794 * __GFP_NOWARN set) should not cause reclaim since the subsystem
1795 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
1796 * using a larger set of nodes after it has established that the
1797 * allowed per node queues are empty and that nodes are
1800 if (NUMA_BUILD
&& (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
1803 wake_all_kswapd(order
, zonelist
, high_zoneidx
);
1807 * OK, we're below the kswapd watermark and have kicked background
1808 * reclaim. Now things get more complex, so set up alloc_flags according
1809 * to how we want to proceed.
1811 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
1813 /* This is the last chance, in general, before the goto nopage. */
1814 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
, zonelist
,
1815 high_zoneidx
, alloc_flags
& ~ALLOC_NO_WATERMARKS
,
1816 preferred_zone
, migratetype
);
1821 /* Allocate without watermarks if the context allows */
1822 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
1823 page
= __alloc_pages_high_priority(gfp_mask
, order
,
1824 zonelist
, high_zoneidx
, nodemask
,
1825 preferred_zone
, migratetype
);
1830 /* Atomic allocations - we can't balance anything */
1834 /* Avoid recursion of direct reclaim */
1835 if (p
->flags
& PF_MEMALLOC
)
1838 /* Avoid allocations with no watermarks from looping endlessly */
1839 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
1842 /* Try direct reclaim and then allocating */
1843 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
,
1844 zonelist
, high_zoneidx
,
1846 alloc_flags
, preferred_zone
,
1847 migratetype
, &did_some_progress
);
1852 * If we failed to make any progress reclaiming, then we are
1853 * running out of options and have to consider going OOM
1855 if (!did_some_progress
) {
1856 if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
1857 if (oom_killer_disabled
)
1859 page
= __alloc_pages_may_oom(gfp_mask
, order
,
1860 zonelist
, high_zoneidx
,
1861 nodemask
, preferred_zone
,
1867 * The OOM killer does not trigger for high-order
1868 * ~__GFP_NOFAIL allocations so if no progress is being
1869 * made, there are no other options and retrying is
1872 if (order
> PAGE_ALLOC_COSTLY_ORDER
&&
1873 !(gfp_mask
& __GFP_NOFAIL
))
1880 /* Check if we should retry the allocation */
1881 pages_reclaimed
+= did_some_progress
;
1882 if (should_alloc_retry(gfp_mask
, order
, pages_reclaimed
)) {
1883 /* Wait for some write requests to complete then retry */
1884 congestion_wait(BLK_RW_ASYNC
, HZ
/50);
1889 if (!(gfp_mask
& __GFP_NOWARN
) && printk_ratelimit()) {
1890 printk(KERN_WARNING
"%s: page allocation failure."
1891 " order:%d, mode:0x%x\n",
1892 p
->comm
, order
, gfp_mask
);
1898 if (kmemcheck_enabled
)
1899 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
1905 * This is the 'heart' of the zoned buddy allocator.
1908 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
1909 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
1911 enum zone_type high_zoneidx
= gfp_zone(gfp_mask
);
1912 struct zone
*preferred_zone
;
1914 int migratetype
= allocflags_to_migratetype(gfp_mask
);
1916 gfp_mask
&= gfp_allowed_mask
;
1918 lockdep_trace_alloc(gfp_mask
);
1920 might_sleep_if(gfp_mask
& __GFP_WAIT
);
1922 if (should_fail_alloc_page(gfp_mask
, order
))
1926 * Check the zones suitable for the gfp_mask contain at least one
1927 * valid zone. It's possible to have an empty zonelist as a result
1928 * of GFP_THISNODE and a memoryless node
1930 if (unlikely(!zonelist
->_zonerefs
->zone
))
1933 /* The preferred zone is used for statistics later */
1934 first_zones_zonelist(zonelist
, high_zoneidx
, nodemask
, &preferred_zone
);
1935 if (!preferred_zone
)
1938 /* First allocation attempt */
1939 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
, order
,
1940 zonelist
, high_zoneidx
, ALLOC_WMARK_LOW
|ALLOC_CPUSET
,
1941 preferred_zone
, migratetype
);
1942 if (unlikely(!page
))
1943 page
= __alloc_pages_slowpath(gfp_mask
, order
,
1944 zonelist
, high_zoneidx
, nodemask
,
1945 preferred_zone
, migratetype
);
1947 trace_mm_page_alloc(page
, order
, gfp_mask
, migratetype
);
1950 EXPORT_SYMBOL(__alloc_pages_nodemask
);
1953 * Common helper functions.
1955 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
1960 * __get_free_pages() returns a 32-bit address, which cannot represent
1963 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
1965 page
= alloc_pages(gfp_mask
, order
);
1968 return (unsigned long) page_address(page
);
1970 EXPORT_SYMBOL(__get_free_pages
);
1972 unsigned long get_zeroed_page(gfp_t gfp_mask
)
1974 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
1976 EXPORT_SYMBOL(get_zeroed_page
);
1978 void __pagevec_free(struct pagevec
*pvec
)
1980 int i
= pagevec_count(pvec
);
1983 trace_mm_pagevec_free(pvec
->pages
[i
], pvec
->cold
);
1984 free_hot_cold_page(pvec
->pages
[i
], pvec
->cold
);
1988 void __free_pages(struct page
*page
, unsigned int order
)
1990 if (put_page_testzero(page
)) {
1991 trace_mm_page_free_direct(page
, order
);
1993 free_hot_page(page
);
1995 __free_pages_ok(page
, order
);
1999 EXPORT_SYMBOL(__free_pages
);
2001 void free_pages(unsigned long addr
, unsigned int order
)
2004 VM_BUG_ON(!virt_addr_valid((void *)addr
));
2005 __free_pages(virt_to_page((void *)addr
), order
);
2009 EXPORT_SYMBOL(free_pages
);
2012 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2013 * @size: the number of bytes to allocate
2014 * @gfp_mask: GFP flags for the allocation
2016 * This function is similar to alloc_pages(), except that it allocates the
2017 * minimum number of pages to satisfy the request. alloc_pages() can only
2018 * allocate memory in power-of-two pages.
2020 * This function is also limited by MAX_ORDER.
2022 * Memory allocated by this function must be released by free_pages_exact().
2024 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
2026 unsigned int order
= get_order(size
);
2029 addr
= __get_free_pages(gfp_mask
, order
);
2031 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
2032 unsigned long used
= addr
+ PAGE_ALIGN(size
);
2034 split_page(virt_to_page((void *)addr
), order
);
2035 while (used
< alloc_end
) {
2041 return (void *)addr
;
2043 EXPORT_SYMBOL(alloc_pages_exact
);
2046 * free_pages_exact - release memory allocated via alloc_pages_exact()
2047 * @virt: the value returned by alloc_pages_exact.
2048 * @size: size of allocation, same value as passed to alloc_pages_exact().
2050 * Release the memory allocated by a previous call to alloc_pages_exact.
2052 void free_pages_exact(void *virt
, size_t size
)
2054 unsigned long addr
= (unsigned long)virt
;
2055 unsigned long end
= addr
+ PAGE_ALIGN(size
);
2057 while (addr
< end
) {
2062 EXPORT_SYMBOL(free_pages_exact
);
2064 static unsigned int nr_free_zone_pages(int offset
)
2069 /* Just pick one node, since fallback list is circular */
2070 unsigned int sum
= 0;
2072 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
2074 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
2075 unsigned long size
= zone
->present_pages
;
2076 unsigned long high
= high_wmark_pages(zone
);
2085 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
2087 unsigned int nr_free_buffer_pages(void)
2089 return nr_free_zone_pages(gfp_zone(GFP_USER
));
2091 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
2094 * Amount of free RAM allocatable within all zones
2096 unsigned int nr_free_pagecache_pages(void)
2098 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
2101 static inline void show_node(struct zone
*zone
)
2104 printk("Node %d ", zone_to_nid(zone
));
2107 void si_meminfo(struct sysinfo
*val
)
2109 val
->totalram
= totalram_pages
;
2111 val
->freeram
= global_page_state(NR_FREE_PAGES
);
2112 val
->bufferram
= nr_blockdev_pages();
2113 val
->totalhigh
= totalhigh_pages
;
2114 val
->freehigh
= nr_free_highpages();
2115 val
->mem_unit
= PAGE_SIZE
;
2118 EXPORT_SYMBOL(si_meminfo
);
2121 void si_meminfo_node(struct sysinfo
*val
, int nid
)
2123 pg_data_t
*pgdat
= NODE_DATA(nid
);
2125 val
->totalram
= pgdat
->node_present_pages
;
2126 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
2127 #ifdef CONFIG_HIGHMEM
2128 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
2129 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
2135 val
->mem_unit
= PAGE_SIZE
;
2139 #define K(x) ((x) << (PAGE_SHIFT-10))
2142 * Show free area list (used inside shift_scroll-lock stuff)
2143 * We also calculate the percentage fragmentation. We do this by counting the
2144 * memory on each free list with the exception of the first item on the list.
2146 void show_free_areas(void)
2151 for_each_populated_zone(zone
) {
2153 printk("%s per-cpu:\n", zone
->name
);
2155 for_each_online_cpu(cpu
) {
2156 struct per_cpu_pageset
*pageset
;
2158 pageset
= zone_pcp(zone
, cpu
);
2160 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
2161 cpu
, pageset
->pcp
.high
,
2162 pageset
->pcp
.batch
, pageset
->pcp
.count
);
2166 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
2167 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
2169 " dirty:%lu writeback:%lu unstable:%lu buffer:%lu\n"
2170 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2171 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
2172 global_page_state(NR_ACTIVE_ANON
),
2173 global_page_state(NR_INACTIVE_ANON
),
2174 global_page_state(NR_ISOLATED_ANON
),
2175 global_page_state(NR_ACTIVE_FILE
),
2176 global_page_state(NR_INACTIVE_FILE
),
2177 global_page_state(NR_ISOLATED_FILE
),
2178 global_page_state(NR_UNEVICTABLE
),
2179 global_page_state(NR_FILE_DIRTY
),
2180 global_page_state(NR_WRITEBACK
),
2181 global_page_state(NR_UNSTABLE_NFS
),
2182 nr_blockdev_pages(),
2183 global_page_state(NR_FREE_PAGES
),
2184 global_page_state(NR_SLAB_RECLAIMABLE
),
2185 global_page_state(NR_SLAB_UNRECLAIMABLE
),
2186 global_page_state(NR_FILE_MAPPED
),
2187 global_page_state(NR_SHMEM
),
2188 global_page_state(NR_PAGETABLE
),
2189 global_page_state(NR_BOUNCE
));
2191 for_each_populated_zone(zone
) {
2200 " active_anon:%lukB"
2201 " inactive_anon:%lukB"
2202 " active_file:%lukB"
2203 " inactive_file:%lukB"
2204 " unevictable:%lukB"
2205 " isolated(anon):%lukB"
2206 " isolated(file):%lukB"
2213 " slab_reclaimable:%lukB"
2214 " slab_unreclaimable:%lukB"
2215 " kernel_stack:%lukB"
2219 " writeback_tmp:%lukB"
2220 " pages_scanned:%lu"
2221 " all_unreclaimable? %s"
2224 K(zone_page_state(zone
, NR_FREE_PAGES
)),
2225 K(min_wmark_pages(zone
)),
2226 K(low_wmark_pages(zone
)),
2227 K(high_wmark_pages(zone
)),
2228 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
2229 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
2230 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
2231 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
2232 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
2233 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
2234 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
2235 K(zone
->present_pages
),
2236 K(zone_page_state(zone
, NR_MLOCK
)),
2237 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
2238 K(zone_page_state(zone
, NR_WRITEBACK
)),
2239 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
2240 K(zone_page_state(zone
, NR_SHMEM
)),
2241 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
2242 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
2243 zone_page_state(zone
, NR_KERNEL_STACK
) *
2245 K(zone_page_state(zone
, NR_PAGETABLE
)),
2246 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
2247 K(zone_page_state(zone
, NR_BOUNCE
)),
2248 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
2249 zone
->pages_scanned
,
2250 (zone_is_all_unreclaimable(zone
) ? "yes" : "no")
2252 printk("lowmem_reserve[]:");
2253 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
2254 printk(" %lu", zone
->lowmem_reserve
[i
]);
2258 for_each_populated_zone(zone
) {
2259 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
2262 printk("%s: ", zone
->name
);
2264 spin_lock_irqsave(&zone
->lock
, flags
);
2265 for (order
= 0; order
< MAX_ORDER
; order
++) {
2266 nr
[order
] = zone
->free_area
[order
].nr_free
;
2267 total
+= nr
[order
] << order
;
2269 spin_unlock_irqrestore(&zone
->lock
, flags
);
2270 for (order
= 0; order
< MAX_ORDER
; order
++)
2271 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
2272 printk("= %lukB\n", K(total
));
2275 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
2277 show_swap_cache_info();
2280 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
2282 zoneref
->zone
= zone
;
2283 zoneref
->zone_idx
= zone_idx(zone
);
2287 * Builds allocation fallback zone lists.
2289 * Add all populated zones of a node to the zonelist.
2291 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
2292 int nr_zones
, enum zone_type zone_type
)
2296 BUG_ON(zone_type
>= MAX_NR_ZONES
);
2301 zone
= pgdat
->node_zones
+ zone_type
;
2302 if (populated_zone(zone
)) {
2303 zoneref_set_zone(zone
,
2304 &zonelist
->_zonerefs
[nr_zones
++]);
2305 check_highest_zone(zone_type
);
2308 } while (zone_type
);
2315 * 0 = automatic detection of better ordering.
2316 * 1 = order by ([node] distance, -zonetype)
2317 * 2 = order by (-zonetype, [node] distance)
2319 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
2320 * the same zonelist. So only NUMA can configure this param.
2322 #define ZONELIST_ORDER_DEFAULT 0
2323 #define ZONELIST_ORDER_NODE 1
2324 #define ZONELIST_ORDER_ZONE 2
2326 /* zonelist order in the kernel.
2327 * set_zonelist_order() will set this to NODE or ZONE.
2329 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2330 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
2334 /* The value user specified ....changed by config */
2335 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2336 /* string for sysctl */
2337 #define NUMA_ZONELIST_ORDER_LEN 16
2338 char numa_zonelist_order
[16] = "default";
2341 * interface for configure zonelist ordering.
2342 * command line option "numa_zonelist_order"
2343 * = "[dD]efault - default, automatic configuration.
2344 * = "[nN]ode - order by node locality, then by zone within node
2345 * = "[zZ]one - order by zone, then by locality within zone
2348 static int __parse_numa_zonelist_order(char *s
)
2350 if (*s
== 'd' || *s
== 'D') {
2351 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2352 } else if (*s
== 'n' || *s
== 'N') {
2353 user_zonelist_order
= ZONELIST_ORDER_NODE
;
2354 } else if (*s
== 'z' || *s
== 'Z') {
2355 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
2358 "Ignoring invalid numa_zonelist_order value: "
2365 static __init
int setup_numa_zonelist_order(char *s
)
2368 return __parse_numa_zonelist_order(s
);
2371 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
2374 * sysctl handler for numa_zonelist_order
2376 int numa_zonelist_order_handler(ctl_table
*table
, int write
,
2377 struct file
*file
, void __user
*buffer
, size_t *length
,
2380 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
2384 strncpy(saved_string
, (char*)table
->data
,
2385 NUMA_ZONELIST_ORDER_LEN
);
2386 ret
= proc_dostring(table
, write
, file
, buffer
, length
, ppos
);
2390 int oldval
= user_zonelist_order
;
2391 if (__parse_numa_zonelist_order((char*)table
->data
)) {
2393 * bogus value. restore saved string
2395 strncpy((char*)table
->data
, saved_string
,
2396 NUMA_ZONELIST_ORDER_LEN
);
2397 user_zonelist_order
= oldval
;
2398 } else if (oldval
!= user_zonelist_order
)
2399 build_all_zonelists();
2405 #define MAX_NODE_LOAD (nr_online_nodes)
2406 static int node_load
[MAX_NUMNODES
];
2409 * find_next_best_node - find the next node that should appear in a given node's fallback list
2410 * @node: node whose fallback list we're appending
2411 * @used_node_mask: nodemask_t of already used nodes
2413 * We use a number of factors to determine which is the next node that should
2414 * appear on a given node's fallback list. The node should not have appeared
2415 * already in @node's fallback list, and it should be the next closest node
2416 * according to the distance array (which contains arbitrary distance values
2417 * from each node to each node in the system), and should also prefer nodes
2418 * with no CPUs, since presumably they'll have very little allocation pressure
2419 * on them otherwise.
2420 * It returns -1 if no node is found.
2422 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
2425 int min_val
= INT_MAX
;
2427 const struct cpumask
*tmp
= cpumask_of_node(0);
2429 /* Use the local node if we haven't already */
2430 if (!node_isset(node
, *used_node_mask
)) {
2431 node_set(node
, *used_node_mask
);
2435 for_each_node_state(n
, N_HIGH_MEMORY
) {
2437 /* Don't want a node to appear more than once */
2438 if (node_isset(n
, *used_node_mask
))
2441 /* Use the distance array to find the distance */
2442 val
= node_distance(node
, n
);
2444 /* Penalize nodes under us ("prefer the next node") */
2447 /* Give preference to headless and unused nodes */
2448 tmp
= cpumask_of_node(n
);
2449 if (!cpumask_empty(tmp
))
2450 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
2452 /* Slight preference for less loaded node */
2453 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
2454 val
+= node_load
[n
];
2456 if (val
< min_val
) {
2463 node_set(best_node
, *used_node_mask
);
2470 * Build zonelists ordered by node and zones within node.
2471 * This results in maximum locality--normal zone overflows into local
2472 * DMA zone, if any--but risks exhausting DMA zone.
2474 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
2477 struct zonelist
*zonelist
;
2479 zonelist
= &pgdat
->node_zonelists
[0];
2480 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
2482 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2484 zonelist
->_zonerefs
[j
].zone
= NULL
;
2485 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2489 * Build gfp_thisnode zonelists
2491 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
2494 struct zonelist
*zonelist
;
2496 zonelist
= &pgdat
->node_zonelists
[1];
2497 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
2498 zonelist
->_zonerefs
[j
].zone
= NULL
;
2499 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2503 * Build zonelists ordered by zone and nodes within zones.
2504 * This results in conserving DMA zone[s] until all Normal memory is
2505 * exhausted, but results in overflowing to remote node while memory
2506 * may still exist in local DMA zone.
2508 static int node_order
[MAX_NUMNODES
];
2510 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
2513 int zone_type
; /* needs to be signed */
2515 struct zonelist
*zonelist
;
2517 zonelist
= &pgdat
->node_zonelists
[0];
2519 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
2520 for (j
= 0; j
< nr_nodes
; j
++) {
2521 node
= node_order
[j
];
2522 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
2523 if (populated_zone(z
)) {
2525 &zonelist
->_zonerefs
[pos
++]);
2526 check_highest_zone(zone_type
);
2530 zonelist
->_zonerefs
[pos
].zone
= NULL
;
2531 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
2534 static int default_zonelist_order(void)
2537 unsigned long low_kmem_size
,total_size
;
2541 * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem.
2542 * If they are really small and used heavily, the system can fall
2543 * into OOM very easily.
2544 * This function detect ZONE_DMA/DMA32 size and confgigures zone order.
2546 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
2549 for_each_online_node(nid
) {
2550 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2551 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2552 if (populated_zone(z
)) {
2553 if (zone_type
< ZONE_NORMAL
)
2554 low_kmem_size
+= z
->present_pages
;
2555 total_size
+= z
->present_pages
;
2559 if (!low_kmem_size
|| /* there are no DMA area. */
2560 low_kmem_size
> total_size
/2) /* DMA/DMA32 is big. */
2561 return ZONELIST_ORDER_NODE
;
2563 * look into each node's config.
2564 * If there is a node whose DMA/DMA32 memory is very big area on
2565 * local memory, NODE_ORDER may be suitable.
2567 average_size
= total_size
/
2568 (nodes_weight(node_states
[N_HIGH_MEMORY
]) + 1);
2569 for_each_online_node(nid
) {
2572 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2573 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2574 if (populated_zone(z
)) {
2575 if (zone_type
< ZONE_NORMAL
)
2576 low_kmem_size
+= z
->present_pages
;
2577 total_size
+= z
->present_pages
;
2580 if (low_kmem_size
&&
2581 total_size
> average_size
&& /* ignore small node */
2582 low_kmem_size
> total_size
* 70/100)
2583 return ZONELIST_ORDER_NODE
;
2585 return ZONELIST_ORDER_ZONE
;
2588 static void set_zonelist_order(void)
2590 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
2591 current_zonelist_order
= default_zonelist_order();
2593 current_zonelist_order
= user_zonelist_order
;
2596 static void build_zonelists(pg_data_t
*pgdat
)
2600 nodemask_t used_mask
;
2601 int local_node
, prev_node
;
2602 struct zonelist
*zonelist
;
2603 int order
= current_zonelist_order
;
2605 /* initialize zonelists */
2606 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
2607 zonelist
= pgdat
->node_zonelists
+ i
;
2608 zonelist
->_zonerefs
[0].zone
= NULL
;
2609 zonelist
->_zonerefs
[0].zone_idx
= 0;
2612 /* NUMA-aware ordering of nodes */
2613 local_node
= pgdat
->node_id
;
2614 load
= nr_online_nodes
;
2615 prev_node
= local_node
;
2616 nodes_clear(used_mask
);
2618 memset(node_order
, 0, sizeof(node_order
));
2621 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
2622 int distance
= node_distance(local_node
, node
);
2625 * If another node is sufficiently far away then it is better
2626 * to reclaim pages in a zone before going off node.
2628 if (distance
> RECLAIM_DISTANCE
)
2629 zone_reclaim_mode
= 1;
2632 * We don't want to pressure a particular node.
2633 * So adding penalty to the first node in same
2634 * distance group to make it round-robin.
2636 if (distance
!= node_distance(local_node
, prev_node
))
2637 node_load
[node
] = load
;
2641 if (order
== ZONELIST_ORDER_NODE
)
2642 build_zonelists_in_node_order(pgdat
, node
);
2644 node_order
[j
++] = node
; /* remember order */
2647 if (order
== ZONELIST_ORDER_ZONE
) {
2648 /* calculate node order -- i.e., DMA last! */
2649 build_zonelists_in_zone_order(pgdat
, j
);
2652 build_thisnode_zonelists(pgdat
);
2655 /* Construct the zonelist performance cache - see further mmzone.h */
2656 static void build_zonelist_cache(pg_data_t
*pgdat
)
2658 struct zonelist
*zonelist
;
2659 struct zonelist_cache
*zlc
;
2662 zonelist
= &pgdat
->node_zonelists
[0];
2663 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
2664 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
2665 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
2666 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
2670 #else /* CONFIG_NUMA */
2672 static void set_zonelist_order(void)
2674 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
2677 static void build_zonelists(pg_data_t
*pgdat
)
2679 int node
, local_node
;
2681 struct zonelist
*zonelist
;
2683 local_node
= pgdat
->node_id
;
2685 zonelist
= &pgdat
->node_zonelists
[0];
2686 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
2689 * Now we build the zonelist so that it contains the zones
2690 * of all the other nodes.
2691 * We don't want to pressure a particular node, so when
2692 * building the zones for node N, we make sure that the
2693 * zones coming right after the local ones are those from
2694 * node N+1 (modulo N)
2696 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
2697 if (!node_online(node
))
2699 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2702 for (node
= 0; node
< local_node
; node
++) {
2703 if (!node_online(node
))
2705 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2709 zonelist
->_zonerefs
[j
].zone
= NULL
;
2710 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2713 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2714 static void build_zonelist_cache(pg_data_t
*pgdat
)
2716 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
2719 #endif /* CONFIG_NUMA */
2721 /* return values int ....just for stop_machine() */
2722 static int __build_all_zonelists(void *dummy
)
2727 memset(node_load
, 0, sizeof(node_load
));
2729 for_each_online_node(nid
) {
2730 pg_data_t
*pgdat
= NODE_DATA(nid
);
2732 build_zonelists(pgdat
);
2733 build_zonelist_cache(pgdat
);
2738 void build_all_zonelists(void)
2740 set_zonelist_order();
2742 if (system_state
== SYSTEM_BOOTING
) {
2743 __build_all_zonelists(NULL
);
2744 mminit_verify_zonelist();
2745 cpuset_init_current_mems_allowed();
2747 /* we have to stop all cpus to guarantee there is no user
2749 stop_machine(__build_all_zonelists
, NULL
, NULL
);
2750 /* cpuset refresh routine should be here */
2752 vm_total_pages
= nr_free_pagecache_pages();
2754 * Disable grouping by mobility if the number of pages in the
2755 * system is too low to allow the mechanism to work. It would be
2756 * more accurate, but expensive to check per-zone. This check is
2757 * made on memory-hotadd so a system can start with mobility
2758 * disabled and enable it later
2760 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
2761 page_group_by_mobility_disabled
= 1;
2763 page_group_by_mobility_disabled
= 0;
2765 printk("Built %i zonelists in %s order, mobility grouping %s. "
2766 "Total pages: %ld\n",
2768 zonelist_order_name
[current_zonelist_order
],
2769 page_group_by_mobility_disabled
? "off" : "on",
2772 printk("Policy zone: %s\n", zone_names
[policy_zone
]);
2777 * Helper functions to size the waitqueue hash table.
2778 * Essentially these want to choose hash table sizes sufficiently
2779 * large so that collisions trying to wait on pages are rare.
2780 * But in fact, the number of active page waitqueues on typical
2781 * systems is ridiculously low, less than 200. So this is even
2782 * conservative, even though it seems large.
2784 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
2785 * waitqueues, i.e. the size of the waitq table given the number of pages.
2787 #define PAGES_PER_WAITQUEUE 256
2789 #ifndef CONFIG_MEMORY_HOTPLUG
2790 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
2792 unsigned long size
= 1;
2794 pages
/= PAGES_PER_WAITQUEUE
;
2796 while (size
< pages
)
2800 * Once we have dozens or even hundreds of threads sleeping
2801 * on IO we've got bigger problems than wait queue collision.
2802 * Limit the size of the wait table to a reasonable size.
2804 size
= min(size
, 4096UL);
2806 return max(size
, 4UL);
2810 * A zone's size might be changed by hot-add, so it is not possible to determine
2811 * a suitable size for its wait_table. So we use the maximum size now.
2813 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
2815 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
2816 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
2817 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
2819 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
2820 * or more by the traditional way. (See above). It equals:
2822 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
2823 * ia64(16K page size) : = ( 8G + 4M)byte.
2824 * powerpc (64K page size) : = (32G +16M)byte.
2826 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
2833 * This is an integer logarithm so that shifts can be used later
2834 * to extract the more random high bits from the multiplicative
2835 * hash function before the remainder is taken.
2837 static inline unsigned long wait_table_bits(unsigned long size
)
2842 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
2845 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2846 * of blocks reserved is based on min_wmark_pages(zone). The memory within
2847 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
2848 * higher will lead to a bigger reserve which will get freed as contiguous
2849 * blocks as reclaim kicks in
2851 static void setup_zone_migrate_reserve(struct zone
*zone
)
2853 unsigned long start_pfn
, pfn
, end_pfn
;
2855 unsigned long block_migratetype
;
2858 /* Get the start pfn, end pfn and the number of blocks to reserve */
2859 start_pfn
= zone
->zone_start_pfn
;
2860 end_pfn
= start_pfn
+ zone
->spanned_pages
;
2861 reserve
= roundup(min_wmark_pages(zone
), pageblock_nr_pages
) >>
2865 * Reserve blocks are generally in place to help high-order atomic
2866 * allocations that are short-lived. A min_free_kbytes value that
2867 * would result in more than 2 reserve blocks for atomic allocations
2868 * is assumed to be in place to help anti-fragmentation for the
2869 * future allocation of hugepages at runtime.
2871 reserve
= min(2, reserve
);
2873 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
2874 if (!pfn_valid(pfn
))
2876 page
= pfn_to_page(pfn
);
2878 /* Watch out for overlapping nodes */
2879 if (page_to_nid(page
) != zone_to_nid(zone
))
2882 /* Blocks with reserved pages will never free, skip them. */
2883 if (PageReserved(page
))
2886 block_migratetype
= get_pageblock_migratetype(page
);
2888 /* If this block is reserved, account for it */
2889 if (reserve
> 0 && block_migratetype
== MIGRATE_RESERVE
) {
2894 /* Suitable for reserving if this block is movable */
2895 if (reserve
> 0 && block_migratetype
== MIGRATE_MOVABLE
) {
2896 set_pageblock_migratetype(page
, MIGRATE_RESERVE
);
2897 move_freepages_block(zone
, page
, MIGRATE_RESERVE
);
2903 * If the reserve is met and this is a previous reserved block,
2906 if (block_migratetype
== MIGRATE_RESERVE
) {
2907 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
2908 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
2914 * Initially all pages are reserved - free ones are freed
2915 * up by free_all_bootmem() once the early boot process is
2916 * done. Non-atomic initialization, single-pass.
2918 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
2919 unsigned long start_pfn
, enum memmap_context context
)
2922 unsigned long end_pfn
= start_pfn
+ size
;
2926 if (highest_memmap_pfn
< end_pfn
- 1)
2927 highest_memmap_pfn
= end_pfn
- 1;
2929 z
= &NODE_DATA(nid
)->node_zones
[zone
];
2930 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
2932 * There can be holes in boot-time mem_map[]s
2933 * handed to this function. They do not
2934 * exist on hotplugged memory.
2936 if (context
== MEMMAP_EARLY
) {
2937 if (!early_pfn_valid(pfn
))
2939 if (!early_pfn_in_nid(pfn
, nid
))
2942 page
= pfn_to_page(pfn
);
2943 set_page_links(page
, zone
, nid
, pfn
);
2944 mminit_verify_page_links(page
, zone
, nid
, pfn
);
2945 init_page_count(page
);
2946 reset_page_mapcount(page
);
2947 SetPageReserved(page
);
2949 * Mark the block movable so that blocks are reserved for
2950 * movable at startup. This will force kernel allocations
2951 * to reserve their blocks rather than leaking throughout
2952 * the address space during boot when many long-lived
2953 * kernel allocations are made. Later some blocks near
2954 * the start are marked MIGRATE_RESERVE by
2955 * setup_zone_migrate_reserve()
2957 * bitmap is created for zone's valid pfn range. but memmap
2958 * can be created for invalid pages (for alignment)
2959 * check here not to call set_pageblock_migratetype() against
2962 if ((z
->zone_start_pfn
<= pfn
)
2963 && (pfn
< z
->zone_start_pfn
+ z
->spanned_pages
)
2964 && !(pfn
& (pageblock_nr_pages
- 1)))
2965 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
2967 INIT_LIST_HEAD(&page
->lru
);
2968 #ifdef WANT_PAGE_VIRTUAL
2969 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
2970 if (!is_highmem_idx(zone
))
2971 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
2976 static void __meminit
zone_init_free_lists(struct zone
*zone
)
2979 for_each_migratetype_order(order
, t
) {
2980 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
2981 zone
->free_area
[order
].nr_free
= 0;
2985 #ifndef __HAVE_ARCH_MEMMAP_INIT
2986 #define memmap_init(size, nid, zone, start_pfn) \
2987 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
2990 static int zone_batchsize(struct zone
*zone
)
2996 * The per-cpu-pages pools are set to around 1000th of the
2997 * size of the zone. But no more than 1/2 of a meg.
2999 * OK, so we don't know how big the cache is. So guess.
3001 batch
= zone
->present_pages
/ 1024;
3002 if (batch
* PAGE_SIZE
> 512 * 1024)
3003 batch
= (512 * 1024) / PAGE_SIZE
;
3004 batch
/= 4; /* We effectively *= 4 below */
3009 * Clamp the batch to a 2^n - 1 value. Having a power
3010 * of 2 value was found to be more likely to have
3011 * suboptimal cache aliasing properties in some cases.
3013 * For example if 2 tasks are alternately allocating
3014 * batches of pages, one task can end up with a lot
3015 * of pages of one half of the possible page colors
3016 * and the other with pages of the other colors.
3018 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
3023 /* The deferral and batching of frees should be suppressed under NOMMU
3026 * The problem is that NOMMU needs to be able to allocate large chunks
3027 * of contiguous memory as there's no hardware page translation to
3028 * assemble apparent contiguous memory from discontiguous pages.
3030 * Queueing large contiguous runs of pages for batching, however,
3031 * causes the pages to actually be freed in smaller chunks. As there
3032 * can be a significant delay between the individual batches being
3033 * recycled, this leads to the once large chunks of space being
3034 * fragmented and becoming unavailable for high-order allocations.
3040 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
3042 struct per_cpu_pages
*pcp
;
3045 memset(p
, 0, sizeof(*p
));
3049 pcp
->high
= 6 * batch
;
3050 pcp
->batch
= max(1UL, 1 * batch
);
3051 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
3052 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
3056 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
3057 * to the value high for the pageset p.
3060 static void setup_pagelist_highmark(struct per_cpu_pageset
*p
,
3063 struct per_cpu_pages
*pcp
;
3067 pcp
->batch
= max(1UL, high
/4);
3068 if ((high
/4) > (PAGE_SHIFT
* 8))
3069 pcp
->batch
= PAGE_SHIFT
* 8;
3075 * Boot pageset table. One per cpu which is going to be used for all
3076 * zones and all nodes. The parameters will be set in such a way
3077 * that an item put on a list will immediately be handed over to
3078 * the buddy list. This is safe since pageset manipulation is done
3079 * with interrupts disabled.
3081 * Some NUMA counter updates may also be caught by the boot pagesets.
3083 * The boot_pagesets must be kept even after bootup is complete for
3084 * unused processors and/or zones. They do play a role for bootstrapping
3085 * hotplugged processors.
3087 * zoneinfo_show() and maybe other functions do
3088 * not check if the processor is online before following the pageset pointer.
3089 * Other parts of the kernel may not check if the zone is available.
3091 static struct per_cpu_pageset boot_pageset
[NR_CPUS
];
3094 * Dynamically allocate memory for the
3095 * per cpu pageset array in struct zone.
3097 static int __cpuinit
process_zones(int cpu
)
3099 struct zone
*zone
, *dzone
;
3100 int node
= cpu_to_node(cpu
);
3102 node_set_state(node
, N_CPU
); /* this node has a cpu */
3104 for_each_populated_zone(zone
) {
3105 zone_pcp(zone
, cpu
) = kmalloc_node(sizeof(struct per_cpu_pageset
),
3107 if (!zone_pcp(zone
, cpu
))
3110 setup_pageset(zone_pcp(zone
, cpu
), zone_batchsize(zone
));
3112 if (percpu_pagelist_fraction
)
3113 setup_pagelist_highmark(zone_pcp(zone
, cpu
),
3114 (zone
->present_pages
/ percpu_pagelist_fraction
));
3119 for_each_zone(dzone
) {
3120 if (!populated_zone(dzone
))
3124 kfree(zone_pcp(dzone
, cpu
));
3125 zone_pcp(dzone
, cpu
) = &boot_pageset
[cpu
];
3130 static inline void free_zone_pagesets(int cpu
)
3134 for_each_zone(zone
) {
3135 struct per_cpu_pageset
*pset
= zone_pcp(zone
, cpu
);
3137 /* Free per_cpu_pageset if it is slab allocated */
3138 if (pset
!= &boot_pageset
[cpu
])
3140 zone_pcp(zone
, cpu
) = &boot_pageset
[cpu
];
3144 static int __cpuinit
pageset_cpuup_callback(struct notifier_block
*nfb
,
3145 unsigned long action
,
3148 int cpu
= (long)hcpu
;
3149 int ret
= NOTIFY_OK
;
3152 case CPU_UP_PREPARE
:
3153 case CPU_UP_PREPARE_FROZEN
:
3154 if (process_zones(cpu
))
3157 case CPU_UP_CANCELED
:
3158 case CPU_UP_CANCELED_FROZEN
:
3160 case CPU_DEAD_FROZEN
:
3161 free_zone_pagesets(cpu
);
3169 static struct notifier_block __cpuinitdata pageset_notifier
=
3170 { &pageset_cpuup_callback
, NULL
, 0 };
3172 void __init
setup_per_cpu_pageset(void)
3176 /* Initialize per_cpu_pageset for cpu 0.
3177 * A cpuup callback will do this for every cpu
3178 * as it comes online
3180 err
= process_zones(smp_processor_id());
3182 register_cpu_notifier(&pageset_notifier
);
3187 static noinline __init_refok
3188 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
3191 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
3195 * The per-page waitqueue mechanism uses hashed waitqueues
3198 zone
->wait_table_hash_nr_entries
=
3199 wait_table_hash_nr_entries(zone_size_pages
);
3200 zone
->wait_table_bits
=
3201 wait_table_bits(zone
->wait_table_hash_nr_entries
);
3202 alloc_size
= zone
->wait_table_hash_nr_entries
3203 * sizeof(wait_queue_head_t
);
3205 if (!slab_is_available()) {
3206 zone
->wait_table
= (wait_queue_head_t
*)
3207 alloc_bootmem_node(pgdat
, alloc_size
);
3210 * This case means that a zone whose size was 0 gets new memory
3211 * via memory hot-add.
3212 * But it may be the case that a new node was hot-added. In
3213 * this case vmalloc() will not be able to use this new node's
3214 * memory - this wait_table must be initialized to use this new
3215 * node itself as well.
3216 * To use this new node's memory, further consideration will be
3219 zone
->wait_table
= vmalloc(alloc_size
);
3221 if (!zone
->wait_table
)
3224 for(i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
3225 init_waitqueue_head(zone
->wait_table
+ i
);
3230 static int __zone_pcp_update(void *data
)
3232 struct zone
*zone
= data
;
3234 unsigned long batch
= zone_batchsize(zone
), flags
;
3236 for (cpu
= 0; cpu
< NR_CPUS
; cpu
++) {
3237 struct per_cpu_pageset
*pset
;
3238 struct per_cpu_pages
*pcp
;
3240 pset
= zone_pcp(zone
, cpu
);
3243 local_irq_save(flags
);
3244 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
3245 setup_pageset(pset
, batch
);
3246 local_irq_restore(flags
);
3251 void zone_pcp_update(struct zone
*zone
)
3253 stop_machine(__zone_pcp_update
, zone
, NULL
);
3256 static __meminit
void zone_pcp_init(struct zone
*zone
)
3259 unsigned long batch
= zone_batchsize(zone
);
3261 for (cpu
= 0; cpu
< NR_CPUS
; cpu
++) {
3263 /* Early boot. Slab allocator not functional yet */
3264 zone_pcp(zone
, cpu
) = &boot_pageset
[cpu
];
3265 setup_pageset(&boot_pageset
[cpu
],0);
3267 setup_pageset(zone_pcp(zone
,cpu
), batch
);
3270 if (zone
->present_pages
)
3271 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%lu\n",
3272 zone
->name
, zone
->present_pages
, batch
);
3275 __meminit
int init_currently_empty_zone(struct zone
*zone
,
3276 unsigned long zone_start_pfn
,
3278 enum memmap_context context
)
3280 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
3282 ret
= zone_wait_table_init(zone
, size
);
3285 pgdat
->nr_zones
= zone_idx(zone
) + 1;
3287 zone
->zone_start_pfn
= zone_start_pfn
;
3289 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
3290 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
3292 (unsigned long)zone_idx(zone
),
3293 zone_start_pfn
, (zone_start_pfn
+ size
));
3295 zone_init_free_lists(zone
);
3300 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3302 * Basic iterator support. Return the first range of PFNs for a node
3303 * Note: nid == MAX_NUMNODES returns first region regardless of node
3305 static int __meminit
first_active_region_index_in_nid(int nid
)
3309 for (i
= 0; i
< nr_nodemap_entries
; i
++)
3310 if (nid
== MAX_NUMNODES
|| early_node_map
[i
].nid
== nid
)
3317 * Basic iterator support. Return the next active range of PFNs for a node
3318 * Note: nid == MAX_NUMNODES returns next region regardless of node
3320 static int __meminit
next_active_region_index_in_nid(int index
, int nid
)
3322 for (index
= index
+ 1; index
< nr_nodemap_entries
; index
++)
3323 if (nid
== MAX_NUMNODES
|| early_node_map
[index
].nid
== nid
)
3329 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
3331 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
3332 * Architectures may implement their own version but if add_active_range()
3333 * was used and there are no special requirements, this is a convenient
3336 int __meminit
__early_pfn_to_nid(unsigned long pfn
)
3340 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
3341 unsigned long start_pfn
= early_node_map
[i
].start_pfn
;
3342 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
3344 if (start_pfn
<= pfn
&& pfn
< end_pfn
)
3345 return early_node_map
[i
].nid
;
3347 /* This is a memory hole */
3350 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
3352 int __meminit
early_pfn_to_nid(unsigned long pfn
)
3356 nid
= __early_pfn_to_nid(pfn
);
3359 /* just returns 0 */
3363 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
3364 bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
3368 nid
= __early_pfn_to_nid(pfn
);
3369 if (nid
>= 0 && nid
!= node
)
3375 /* Basic iterator support to walk early_node_map[] */
3376 #define for_each_active_range_index_in_nid(i, nid) \
3377 for (i = first_active_region_index_in_nid(nid); i != -1; \
3378 i = next_active_region_index_in_nid(i, nid))
3381 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
3382 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
3383 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
3385 * If an architecture guarantees that all ranges registered with
3386 * add_active_ranges() contain no holes and may be freed, this
3387 * this function may be used instead of calling free_bootmem() manually.
3389 void __init
free_bootmem_with_active_regions(int nid
,
3390 unsigned long max_low_pfn
)
3394 for_each_active_range_index_in_nid(i
, nid
) {
3395 unsigned long size_pages
= 0;
3396 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
3398 if (early_node_map
[i
].start_pfn
>= max_low_pfn
)
3401 if (end_pfn
> max_low_pfn
)
3402 end_pfn
= max_low_pfn
;
3404 size_pages
= end_pfn
- early_node_map
[i
].start_pfn
;
3405 free_bootmem_node(NODE_DATA(early_node_map
[i
].nid
),
3406 PFN_PHYS(early_node_map
[i
].start_pfn
),
3407 size_pages
<< PAGE_SHIFT
);
3411 void __init
work_with_active_regions(int nid
, work_fn_t work_fn
, void *data
)
3416 for_each_active_range_index_in_nid(i
, nid
) {
3417 ret
= work_fn(early_node_map
[i
].start_pfn
,
3418 early_node_map
[i
].end_pfn
, data
);
3424 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3425 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3427 * If an architecture guarantees that all ranges registered with
3428 * add_active_ranges() contain no holes and may be freed, this
3429 * function may be used instead of calling memory_present() manually.
3431 void __init
sparse_memory_present_with_active_regions(int nid
)
3435 for_each_active_range_index_in_nid(i
, nid
)
3436 memory_present(early_node_map
[i
].nid
,
3437 early_node_map
[i
].start_pfn
,
3438 early_node_map
[i
].end_pfn
);
3442 * get_pfn_range_for_nid - Return the start and end page frames for a node
3443 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
3444 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
3445 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
3447 * It returns the start and end page frame of a node based on information
3448 * provided by an arch calling add_active_range(). If called for a node
3449 * with no available memory, a warning is printed and the start and end
3452 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
3453 unsigned long *start_pfn
, unsigned long *end_pfn
)
3459 for_each_active_range_index_in_nid(i
, nid
) {
3460 *start_pfn
= min(*start_pfn
, early_node_map
[i
].start_pfn
);
3461 *end_pfn
= max(*end_pfn
, early_node_map
[i
].end_pfn
);
3464 if (*start_pfn
== -1UL)
3469 * This finds a zone that can be used for ZONE_MOVABLE pages. The
3470 * assumption is made that zones within a node are ordered in monotonic
3471 * increasing memory addresses so that the "highest" populated zone is used
3473 static void __init
find_usable_zone_for_movable(void)
3476 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
3477 if (zone_index
== ZONE_MOVABLE
)
3480 if (arch_zone_highest_possible_pfn
[zone_index
] >
3481 arch_zone_lowest_possible_pfn
[zone_index
])
3485 VM_BUG_ON(zone_index
== -1);
3486 movable_zone
= zone_index
;
3490 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
3491 * because it is sized independant of architecture. Unlike the other zones,
3492 * the starting point for ZONE_MOVABLE is not fixed. It may be different
3493 * in each node depending on the size of each node and how evenly kernelcore
3494 * is distributed. This helper function adjusts the zone ranges
3495 * provided by the architecture for a given node by using the end of the
3496 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
3497 * zones within a node are in order of monotonic increases memory addresses
3499 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
3500 unsigned long zone_type
,
3501 unsigned long node_start_pfn
,
3502 unsigned long node_end_pfn
,
3503 unsigned long *zone_start_pfn
,
3504 unsigned long *zone_end_pfn
)
3506 /* Only adjust if ZONE_MOVABLE is on this node */
3507 if (zone_movable_pfn
[nid
]) {
3508 /* Size ZONE_MOVABLE */
3509 if (zone_type
== ZONE_MOVABLE
) {
3510 *zone_start_pfn
= zone_movable_pfn
[nid
];
3511 *zone_end_pfn
= min(node_end_pfn
,
3512 arch_zone_highest_possible_pfn
[movable_zone
]);
3514 /* Adjust for ZONE_MOVABLE starting within this range */
3515 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
3516 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
3517 *zone_end_pfn
= zone_movable_pfn
[nid
];
3519 /* Check if this whole range is within ZONE_MOVABLE */
3520 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
3521 *zone_start_pfn
= *zone_end_pfn
;
3526 * Return the number of pages a zone spans in a node, including holes
3527 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
3529 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3530 unsigned long zone_type
,
3531 unsigned long *ignored
)
3533 unsigned long node_start_pfn
, node_end_pfn
;
3534 unsigned long zone_start_pfn
, zone_end_pfn
;
3536 /* Get the start and end of the node and zone */
3537 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3538 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
3539 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
3540 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3541 node_start_pfn
, node_end_pfn
,
3542 &zone_start_pfn
, &zone_end_pfn
);
3544 /* Check that this node has pages within the zone's required range */
3545 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
3548 /* Move the zone boundaries inside the node if necessary */
3549 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
3550 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
3552 /* Return the spanned pages */
3553 return zone_end_pfn
- zone_start_pfn
;
3557 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
3558 * then all holes in the requested range will be accounted for.
3560 static unsigned long __meminit
__absent_pages_in_range(int nid
,
3561 unsigned long range_start_pfn
,
3562 unsigned long range_end_pfn
)
3565 unsigned long prev_end_pfn
= 0, hole_pages
= 0;
3566 unsigned long start_pfn
;
3568 /* Find the end_pfn of the first active range of pfns in the node */
3569 i
= first_active_region_index_in_nid(nid
);
3573 prev_end_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3575 /* Account for ranges before physical memory on this node */
3576 if (early_node_map
[i
].start_pfn
> range_start_pfn
)
3577 hole_pages
= prev_end_pfn
- range_start_pfn
;
3579 /* Find all holes for the zone within the node */
3580 for (; i
!= -1; i
= next_active_region_index_in_nid(i
, nid
)) {
3582 /* No need to continue if prev_end_pfn is outside the zone */
3583 if (prev_end_pfn
>= range_end_pfn
)
3586 /* Make sure the end of the zone is not within the hole */
3587 start_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3588 prev_end_pfn
= max(prev_end_pfn
, range_start_pfn
);
3590 /* Update the hole size cound and move on */
3591 if (start_pfn
> range_start_pfn
) {
3592 BUG_ON(prev_end_pfn
> start_pfn
);
3593 hole_pages
+= start_pfn
- prev_end_pfn
;
3595 prev_end_pfn
= early_node_map
[i
].end_pfn
;
3598 /* Account for ranges past physical memory on this node */
3599 if (range_end_pfn
> prev_end_pfn
)
3600 hole_pages
+= range_end_pfn
-
3601 max(range_start_pfn
, prev_end_pfn
);
3607 * absent_pages_in_range - Return number of page frames in holes within a range
3608 * @start_pfn: The start PFN to start searching for holes
3609 * @end_pfn: The end PFN to stop searching for holes
3611 * It returns the number of pages frames in memory holes within a range.
3613 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
3614 unsigned long end_pfn
)
3616 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
3619 /* Return the number of page frames in holes in a zone on a node */
3620 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
3621 unsigned long zone_type
,
3622 unsigned long *ignored
)
3624 unsigned long node_start_pfn
, node_end_pfn
;
3625 unsigned long zone_start_pfn
, zone_end_pfn
;
3627 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3628 zone_start_pfn
= max(arch_zone_lowest_possible_pfn
[zone_type
],
3630 zone_end_pfn
= min(arch_zone_highest_possible_pfn
[zone_type
],
3633 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3634 node_start_pfn
, node_end_pfn
,
3635 &zone_start_pfn
, &zone_end_pfn
);
3636 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
3640 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3641 unsigned long zone_type
,
3642 unsigned long *zones_size
)
3644 return zones_size
[zone_type
];
3647 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
3648 unsigned long zone_type
,
3649 unsigned long *zholes_size
)
3654 return zholes_size
[zone_type
];
3659 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
3660 unsigned long *zones_size
, unsigned long *zholes_size
)
3662 unsigned long realtotalpages
, totalpages
= 0;
3665 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3666 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
3668 pgdat
->node_spanned_pages
= totalpages
;
3670 realtotalpages
= totalpages
;
3671 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3673 zone_absent_pages_in_node(pgdat
->node_id
, i
,
3675 pgdat
->node_present_pages
= realtotalpages
;
3676 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
3680 #ifndef CONFIG_SPARSEMEM
3682 * Calculate the size of the zone->blockflags rounded to an unsigned long
3683 * Start by making sure zonesize is a multiple of pageblock_order by rounding
3684 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
3685 * round what is now in bits to nearest long in bits, then return it in
3688 static unsigned long __init
usemap_size(unsigned long zonesize
)
3690 unsigned long usemapsize
;
3692 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
3693 usemapsize
= usemapsize
>> pageblock_order
;
3694 usemapsize
*= NR_PAGEBLOCK_BITS
;
3695 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
3697 return usemapsize
/ 8;
3700 static void __init
setup_usemap(struct pglist_data
*pgdat
,
3701 struct zone
*zone
, unsigned long zonesize
)
3703 unsigned long usemapsize
= usemap_size(zonesize
);
3704 zone
->pageblock_flags
= NULL
;
3706 zone
->pageblock_flags
= alloc_bootmem_node(pgdat
, usemapsize
);
3709 static void inline setup_usemap(struct pglist_data
*pgdat
,
3710 struct zone
*zone
, unsigned long zonesize
) {}
3711 #endif /* CONFIG_SPARSEMEM */
3713 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3715 /* Return a sensible default order for the pageblock size. */
3716 static inline int pageblock_default_order(void)
3718 if (HPAGE_SHIFT
> PAGE_SHIFT
)
3719 return HUGETLB_PAGE_ORDER
;
3724 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
3725 static inline void __init
set_pageblock_order(unsigned int order
)
3727 /* Check that pageblock_nr_pages has not already been setup */
3728 if (pageblock_order
)
3732 * Assume the largest contiguous order of interest is a huge page.
3733 * This value may be variable depending on boot parameters on IA64
3735 pageblock_order
= order
;
3737 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3740 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
3741 * and pageblock_default_order() are unused as pageblock_order is set
3742 * at compile-time. See include/linux/pageblock-flags.h for the values of
3743 * pageblock_order based on the kernel config
3745 static inline int pageblock_default_order(unsigned int order
)
3749 #define set_pageblock_order(x) do {} while (0)
3751 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3754 * Set up the zone data structures:
3755 * - mark all pages reserved
3756 * - mark all memory queues empty
3757 * - clear the memory bitmaps
3759 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
,
3760 unsigned long *zones_size
, unsigned long *zholes_size
)
3763 int nid
= pgdat
->node_id
;
3764 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
3767 pgdat_resize_init(pgdat
);
3768 pgdat
->nr_zones
= 0;
3769 init_waitqueue_head(&pgdat
->kswapd_wait
);
3770 pgdat
->kswapd_max_order
= 0;
3771 pgdat_page_cgroup_init(pgdat
);
3773 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
3774 struct zone
*zone
= pgdat
->node_zones
+ j
;
3775 unsigned long size
, realsize
, memmap_pages
;
3778 size
= zone_spanned_pages_in_node(nid
, j
, zones_size
);
3779 realsize
= size
- zone_absent_pages_in_node(nid
, j
,
3783 * Adjust realsize so that it accounts for how much memory
3784 * is used by this zone for memmap. This affects the watermark
3785 * and per-cpu initialisations
3788 PAGE_ALIGN(size
* sizeof(struct page
)) >> PAGE_SHIFT
;
3789 if (realsize
>= memmap_pages
) {
3790 realsize
-= memmap_pages
;
3793 " %s zone: %lu pages used for memmap\n",
3794 zone_names
[j
], memmap_pages
);
3797 " %s zone: %lu pages exceeds realsize %lu\n",
3798 zone_names
[j
], memmap_pages
, realsize
);
3800 /* Account for reserved pages */
3801 if (j
== 0 && realsize
> dma_reserve
) {
3802 realsize
-= dma_reserve
;
3803 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
3804 zone_names
[0], dma_reserve
);
3807 if (!is_highmem_idx(j
))
3808 nr_kernel_pages
+= realsize
;
3809 nr_all_pages
+= realsize
;
3811 zone
->spanned_pages
= size
;
3812 zone
->present_pages
= realsize
;
3815 zone
->min_unmapped_pages
= (realsize
*sysctl_min_unmapped_ratio
)
3817 zone
->min_slab_pages
= (realsize
* sysctl_min_slab_ratio
) / 100;
3819 zone
->name
= zone_names
[j
];
3820 spin_lock_init(&zone
->lock
);
3821 spin_lock_init(&zone
->lru_lock
);
3822 zone_seqlock_init(zone
);
3823 zone
->zone_pgdat
= pgdat
;
3825 zone
->prev_priority
= DEF_PRIORITY
;
3827 zone_pcp_init(zone
);
3829 INIT_LIST_HEAD(&zone
->lru
[l
].list
);
3830 zone
->reclaim_stat
.nr_saved_scan
[l
] = 0;
3832 zone
->reclaim_stat
.recent_rotated
[0] = 0;
3833 zone
->reclaim_stat
.recent_rotated
[1] = 0;
3834 zone
->reclaim_stat
.recent_scanned
[0] = 0;
3835 zone
->reclaim_stat
.recent_scanned
[1] = 0;
3836 zap_zone_vm_stats(zone
);
3841 set_pageblock_order(pageblock_default_order());
3842 setup_usemap(pgdat
, zone
, size
);
3843 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
3844 size
, MEMMAP_EARLY
);
3846 memmap_init(size
, nid
, j
, zone_start_pfn
);
3847 zone_start_pfn
+= size
;
3851 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
3853 /* Skip empty nodes */
3854 if (!pgdat
->node_spanned_pages
)
3857 #ifdef CONFIG_FLAT_NODE_MEM_MAP
3858 /* ia64 gets its own node_mem_map, before this, without bootmem */
3859 if (!pgdat
->node_mem_map
) {
3860 unsigned long size
, start
, end
;
3864 * The zone's endpoints aren't required to be MAX_ORDER
3865 * aligned but the node_mem_map endpoints must be in order
3866 * for the buddy allocator to function correctly.
3868 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
3869 end
= pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
3870 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
3871 size
= (end
- start
) * sizeof(struct page
);
3872 map
= alloc_remap(pgdat
->node_id
, size
);
3874 map
= alloc_bootmem_node(pgdat
, size
);
3875 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
3877 #ifndef CONFIG_NEED_MULTIPLE_NODES
3879 * With no DISCONTIG, the global mem_map is just set as node 0's
3881 if (pgdat
== NODE_DATA(0)) {
3882 mem_map
= NODE_DATA(0)->node_mem_map
;
3883 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3884 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
3885 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
3886 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
3889 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
3892 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
3893 unsigned long node_start_pfn
, unsigned long *zholes_size
)
3895 pg_data_t
*pgdat
= NODE_DATA(nid
);
3897 pgdat
->node_id
= nid
;
3898 pgdat
->node_start_pfn
= node_start_pfn
;
3899 calculate_node_totalpages(pgdat
, zones_size
, zholes_size
);
3901 alloc_node_mem_map(pgdat
);
3902 #ifdef CONFIG_FLAT_NODE_MEM_MAP
3903 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
3904 nid
, (unsigned long)pgdat
,
3905 (unsigned long)pgdat
->node_mem_map
);
3908 free_area_init_core(pgdat
, zones_size
, zholes_size
);
3911 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3913 #if MAX_NUMNODES > 1
3915 * Figure out the number of possible node ids.
3917 static void __init
setup_nr_node_ids(void)
3920 unsigned int highest
= 0;
3922 for_each_node_mask(node
, node_possible_map
)
3924 nr_node_ids
= highest
+ 1;
3927 static inline void setup_nr_node_ids(void)
3933 * add_active_range - Register a range of PFNs backed by physical memory
3934 * @nid: The node ID the range resides on
3935 * @start_pfn: The start PFN of the available physical memory
3936 * @end_pfn: The end PFN of the available physical memory
3938 * These ranges are stored in an early_node_map[] and later used by
3939 * free_area_init_nodes() to calculate zone sizes and holes. If the
3940 * range spans a memory hole, it is up to the architecture to ensure
3941 * the memory is not freed by the bootmem allocator. If possible
3942 * the range being registered will be merged with existing ranges.
3944 void __init
add_active_range(unsigned int nid
, unsigned long start_pfn
,
3945 unsigned long end_pfn
)
3949 mminit_dprintk(MMINIT_TRACE
, "memory_register",
3950 "Entering add_active_range(%d, %#lx, %#lx) "
3951 "%d entries of %d used\n",
3952 nid
, start_pfn
, end_pfn
,
3953 nr_nodemap_entries
, MAX_ACTIVE_REGIONS
);
3955 mminit_validate_memmodel_limits(&start_pfn
, &end_pfn
);
3957 /* Merge with existing active regions if possible */
3958 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
3959 if (early_node_map
[i
].nid
!= nid
)
3962 /* Skip if an existing region covers this new one */
3963 if (start_pfn
>= early_node_map
[i
].start_pfn
&&
3964 end_pfn
<= early_node_map
[i
].end_pfn
)
3967 /* Merge forward if suitable */
3968 if (start_pfn
<= early_node_map
[i
].end_pfn
&&
3969 end_pfn
> early_node_map
[i
].end_pfn
) {
3970 early_node_map
[i
].end_pfn
= end_pfn
;
3974 /* Merge backward if suitable */
3975 if (start_pfn
< early_node_map
[i
].end_pfn
&&
3976 end_pfn
>= early_node_map
[i
].start_pfn
) {
3977 early_node_map
[i
].start_pfn
= start_pfn
;
3982 /* Check that early_node_map is large enough */
3983 if (i
>= MAX_ACTIVE_REGIONS
) {
3984 printk(KERN_CRIT
"More than %d memory regions, truncating\n",
3985 MAX_ACTIVE_REGIONS
);
3989 early_node_map
[i
].nid
= nid
;
3990 early_node_map
[i
].start_pfn
= start_pfn
;
3991 early_node_map
[i
].end_pfn
= end_pfn
;
3992 nr_nodemap_entries
= i
+ 1;
3996 * remove_active_range - Shrink an existing registered range of PFNs
3997 * @nid: The node id the range is on that should be shrunk
3998 * @start_pfn: The new PFN of the range
3999 * @end_pfn: The new PFN of the range
4001 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
4002 * The map is kept near the end physical page range that has already been
4003 * registered. This function allows an arch to shrink an existing registered
4006 void __init
remove_active_range(unsigned int nid
, unsigned long start_pfn
,
4007 unsigned long end_pfn
)
4012 printk(KERN_DEBUG
"remove_active_range (%d, %lu, %lu)\n",
4013 nid
, start_pfn
, end_pfn
);
4015 /* Find the old active region end and shrink */
4016 for_each_active_range_index_in_nid(i
, nid
) {
4017 if (early_node_map
[i
].start_pfn
>= start_pfn
&&
4018 early_node_map
[i
].end_pfn
<= end_pfn
) {
4020 early_node_map
[i
].start_pfn
= 0;
4021 early_node_map
[i
].end_pfn
= 0;
4025 if (early_node_map
[i
].start_pfn
< start_pfn
&&
4026 early_node_map
[i
].end_pfn
> start_pfn
) {
4027 unsigned long temp_end_pfn
= early_node_map
[i
].end_pfn
;
4028 early_node_map
[i
].end_pfn
= start_pfn
;
4029 if (temp_end_pfn
> end_pfn
)
4030 add_active_range(nid
, end_pfn
, temp_end_pfn
);
4033 if (early_node_map
[i
].start_pfn
>= start_pfn
&&
4034 early_node_map
[i
].end_pfn
> end_pfn
&&
4035 early_node_map
[i
].start_pfn
< end_pfn
) {
4036 early_node_map
[i
].start_pfn
= end_pfn
;
4044 /* remove the blank ones */
4045 for (i
= nr_nodemap_entries
- 1; i
> 0; i
--) {
4046 if (early_node_map
[i
].nid
!= nid
)
4048 if (early_node_map
[i
].end_pfn
)
4050 /* we found it, get rid of it */
4051 for (j
= i
; j
< nr_nodemap_entries
- 1; j
++)
4052 memcpy(&early_node_map
[j
], &early_node_map
[j
+1],
4053 sizeof(early_node_map
[j
]));
4054 j
= nr_nodemap_entries
- 1;
4055 memset(&early_node_map
[j
], 0, sizeof(early_node_map
[j
]));
4056 nr_nodemap_entries
--;
4061 * remove_all_active_ranges - Remove all currently registered regions
4063 * During discovery, it may be found that a table like SRAT is invalid
4064 * and an alternative discovery method must be used. This function removes
4065 * all currently registered regions.
4067 void __init
remove_all_active_ranges(void)
4069 memset(early_node_map
, 0, sizeof(early_node_map
));
4070 nr_nodemap_entries
= 0;
4073 /* Compare two active node_active_regions */
4074 static int __init
cmp_node_active_region(const void *a
, const void *b
)
4076 struct node_active_region
*arange
= (struct node_active_region
*)a
;
4077 struct node_active_region
*brange
= (struct node_active_region
*)b
;
4079 /* Done this way to avoid overflows */
4080 if (arange
->start_pfn
> brange
->start_pfn
)
4082 if (arange
->start_pfn
< brange
->start_pfn
)
4088 /* sort the node_map by start_pfn */
4089 static void __init
sort_node_map(void)
4091 sort(early_node_map
, (size_t)nr_nodemap_entries
,
4092 sizeof(struct node_active_region
),
4093 cmp_node_active_region
, NULL
);
4096 /* Find the lowest pfn for a node */
4097 static unsigned long __init
find_min_pfn_for_node(int nid
)
4100 unsigned long min_pfn
= ULONG_MAX
;
4102 /* Assuming a sorted map, the first range found has the starting pfn */
4103 for_each_active_range_index_in_nid(i
, nid
)
4104 min_pfn
= min(min_pfn
, early_node_map
[i
].start_pfn
);
4106 if (min_pfn
== ULONG_MAX
) {
4108 "Could not find start_pfn for node %d\n", nid
);
4116 * find_min_pfn_with_active_regions - Find the minimum PFN registered
4118 * It returns the minimum PFN based on information provided via
4119 * add_active_range().
4121 unsigned long __init
find_min_pfn_with_active_regions(void)
4123 return find_min_pfn_for_node(MAX_NUMNODES
);
4127 * early_calculate_totalpages()
4128 * Sum pages in active regions for movable zone.
4129 * Populate N_HIGH_MEMORY for calculating usable_nodes.
4131 static unsigned long __init
early_calculate_totalpages(void)
4134 unsigned long totalpages
= 0;
4136 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
4137 unsigned long pages
= early_node_map
[i
].end_pfn
-
4138 early_node_map
[i
].start_pfn
;
4139 totalpages
+= pages
;
4141 node_set_state(early_node_map
[i
].nid
, N_HIGH_MEMORY
);
4147 * Find the PFN the Movable zone begins in each node. Kernel memory
4148 * is spread evenly between nodes as long as the nodes have enough
4149 * memory. When they don't, some nodes will have more kernelcore than
4152 static void __init
find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn
)
4155 unsigned long usable_startpfn
;
4156 unsigned long kernelcore_node
, kernelcore_remaining
;
4157 /* save the state before borrow the nodemask */
4158 nodemask_t saved_node_state
= node_states
[N_HIGH_MEMORY
];
4159 unsigned long totalpages
= early_calculate_totalpages();
4160 int usable_nodes
= nodes_weight(node_states
[N_HIGH_MEMORY
]);
4163 * If movablecore was specified, calculate what size of
4164 * kernelcore that corresponds so that memory usable for
4165 * any allocation type is evenly spread. If both kernelcore
4166 * and movablecore are specified, then the value of kernelcore
4167 * will be used for required_kernelcore if it's greater than
4168 * what movablecore would have allowed.
4170 if (required_movablecore
) {
4171 unsigned long corepages
;
4174 * Round-up so that ZONE_MOVABLE is at least as large as what
4175 * was requested by the user
4177 required_movablecore
=
4178 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
4179 corepages
= totalpages
- required_movablecore
;
4181 required_kernelcore
= max(required_kernelcore
, corepages
);
4184 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
4185 if (!required_kernelcore
)
4188 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
4189 find_usable_zone_for_movable();
4190 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
4193 /* Spread kernelcore memory as evenly as possible throughout nodes */
4194 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4195 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4197 * Recalculate kernelcore_node if the division per node
4198 * now exceeds what is necessary to satisfy the requested
4199 * amount of memory for the kernel
4201 if (required_kernelcore
< kernelcore_node
)
4202 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4205 * As the map is walked, we track how much memory is usable
4206 * by the kernel using kernelcore_remaining. When it is
4207 * 0, the rest of the node is usable by ZONE_MOVABLE
4209 kernelcore_remaining
= kernelcore_node
;
4211 /* Go through each range of PFNs within this node */
4212 for_each_active_range_index_in_nid(i
, nid
) {
4213 unsigned long start_pfn
, end_pfn
;
4214 unsigned long size_pages
;
4216 start_pfn
= max(early_node_map
[i
].start_pfn
,
4217 zone_movable_pfn
[nid
]);
4218 end_pfn
= early_node_map
[i
].end_pfn
;
4219 if (start_pfn
>= end_pfn
)
4222 /* Account for what is only usable for kernelcore */
4223 if (start_pfn
< usable_startpfn
) {
4224 unsigned long kernel_pages
;
4225 kernel_pages
= min(end_pfn
, usable_startpfn
)
4228 kernelcore_remaining
-= min(kernel_pages
,
4229 kernelcore_remaining
);
4230 required_kernelcore
-= min(kernel_pages
,
4231 required_kernelcore
);
4233 /* Continue if range is now fully accounted */
4234 if (end_pfn
<= usable_startpfn
) {
4237 * Push zone_movable_pfn to the end so
4238 * that if we have to rebalance
4239 * kernelcore across nodes, we will
4240 * not double account here
4242 zone_movable_pfn
[nid
] = end_pfn
;
4245 start_pfn
= usable_startpfn
;
4249 * The usable PFN range for ZONE_MOVABLE is from
4250 * start_pfn->end_pfn. Calculate size_pages as the
4251 * number of pages used as kernelcore
4253 size_pages
= end_pfn
- start_pfn
;
4254 if (size_pages
> kernelcore_remaining
)
4255 size_pages
= kernelcore_remaining
;
4256 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
4259 * Some kernelcore has been met, update counts and
4260 * break if the kernelcore for this node has been
4263 required_kernelcore
-= min(required_kernelcore
,
4265 kernelcore_remaining
-= size_pages
;
4266 if (!kernelcore_remaining
)
4272 * If there is still required_kernelcore, we do another pass with one
4273 * less node in the count. This will push zone_movable_pfn[nid] further
4274 * along on the nodes that still have memory until kernelcore is
4278 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
4281 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
4282 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
4283 zone_movable_pfn
[nid
] =
4284 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
4287 /* restore the node_state */
4288 node_states
[N_HIGH_MEMORY
] = saved_node_state
;
4291 /* Any regular memory on that node ? */
4292 static void check_for_regular_memory(pg_data_t
*pgdat
)
4294 #ifdef CONFIG_HIGHMEM
4295 enum zone_type zone_type
;
4297 for (zone_type
= 0; zone_type
<= ZONE_NORMAL
; zone_type
++) {
4298 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4299 if (zone
->present_pages
)
4300 node_set_state(zone_to_nid(zone
), N_NORMAL_MEMORY
);
4306 * free_area_init_nodes - Initialise all pg_data_t and zone data
4307 * @max_zone_pfn: an array of max PFNs for each zone
4309 * This will call free_area_init_node() for each active node in the system.
4310 * Using the page ranges provided by add_active_range(), the size of each
4311 * zone in each node and their holes is calculated. If the maximum PFN
4312 * between two adjacent zones match, it is assumed that the zone is empty.
4313 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
4314 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
4315 * starts where the previous one ended. For example, ZONE_DMA32 starts
4316 * at arch_max_dma_pfn.
4318 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
4323 /* Sort early_node_map as initialisation assumes it is sorted */
4326 /* Record where the zone boundaries are */
4327 memset(arch_zone_lowest_possible_pfn
, 0,
4328 sizeof(arch_zone_lowest_possible_pfn
));
4329 memset(arch_zone_highest_possible_pfn
, 0,
4330 sizeof(arch_zone_highest_possible_pfn
));
4331 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
4332 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
4333 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
4334 if (i
== ZONE_MOVABLE
)
4336 arch_zone_lowest_possible_pfn
[i
] =
4337 arch_zone_highest_possible_pfn
[i
-1];
4338 arch_zone_highest_possible_pfn
[i
] =
4339 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
4341 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
4342 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
4344 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
4345 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
4346 find_zone_movable_pfns_for_nodes(zone_movable_pfn
);
4348 /* Print out the zone ranges */
4349 printk("Zone PFN ranges:\n");
4350 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4351 if (i
== ZONE_MOVABLE
)
4353 printk(" %-8s %0#10lx -> %0#10lx\n",
4355 arch_zone_lowest_possible_pfn
[i
],
4356 arch_zone_highest_possible_pfn
[i
]);
4359 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
4360 printk("Movable zone start PFN for each node\n");
4361 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
4362 if (zone_movable_pfn
[i
])
4363 printk(" Node %d: %lu\n", i
, zone_movable_pfn
[i
]);
4366 /* Print out the early_node_map[] */
4367 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries
);
4368 for (i
= 0; i
< nr_nodemap_entries
; i
++)
4369 printk(" %3d: %0#10lx -> %0#10lx\n", early_node_map
[i
].nid
,
4370 early_node_map
[i
].start_pfn
,
4371 early_node_map
[i
].end_pfn
);
4373 /* Initialise every node */
4374 mminit_verify_pageflags_layout();
4375 setup_nr_node_ids();
4376 for_each_online_node(nid
) {
4377 pg_data_t
*pgdat
= NODE_DATA(nid
);
4378 free_area_init_node(nid
, NULL
,
4379 find_min_pfn_for_node(nid
), NULL
);
4381 /* Any memory on that node */
4382 if (pgdat
->node_present_pages
)
4383 node_set_state(nid
, N_HIGH_MEMORY
);
4384 check_for_regular_memory(pgdat
);
4388 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
4390 unsigned long long coremem
;
4394 coremem
= memparse(p
, &p
);
4395 *core
= coremem
>> PAGE_SHIFT
;
4397 /* Paranoid check that UL is enough for the coremem value */
4398 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
4404 * kernelcore=size sets the amount of memory for use for allocations that
4405 * cannot be reclaimed or migrated.
4407 static int __init
cmdline_parse_kernelcore(char *p
)
4409 return cmdline_parse_core(p
, &required_kernelcore
);
4413 * movablecore=size sets the amount of memory for use for allocations that
4414 * can be reclaimed or migrated.
4416 static int __init
cmdline_parse_movablecore(char *p
)
4418 return cmdline_parse_core(p
, &required_movablecore
);
4421 early_param("kernelcore", cmdline_parse_kernelcore
);
4422 early_param("movablecore", cmdline_parse_movablecore
);
4424 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
4427 * set_dma_reserve - set the specified number of pages reserved in the first zone
4428 * @new_dma_reserve: The number of pages to mark reserved
4430 * The per-cpu batchsize and zone watermarks are determined by present_pages.
4431 * In the DMA zone, a significant percentage may be consumed by kernel image
4432 * and other unfreeable allocations which can skew the watermarks badly. This
4433 * function may optionally be used to account for unfreeable pages in the
4434 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
4435 * smaller per-cpu batchsize.
4437 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
4439 dma_reserve
= new_dma_reserve
;
4442 #ifndef CONFIG_NEED_MULTIPLE_NODES
4443 struct pglist_data __refdata contig_page_data
= { .bdata
= &bootmem_node_data
[0] };
4444 EXPORT_SYMBOL(contig_page_data
);
4447 void __init
free_area_init(unsigned long *zones_size
)
4449 free_area_init_node(0, zones_size
,
4450 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
4453 static int page_alloc_cpu_notify(struct notifier_block
*self
,
4454 unsigned long action
, void *hcpu
)
4456 int cpu
= (unsigned long)hcpu
;
4458 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
4462 * Spill the event counters of the dead processor
4463 * into the current processors event counters.
4464 * This artificially elevates the count of the current
4467 vm_events_fold_cpu(cpu
);
4470 * Zero the differential counters of the dead processor
4471 * so that the vm statistics are consistent.
4473 * This is only okay since the processor is dead and cannot
4474 * race with what we are doing.
4476 refresh_cpu_vm_stats(cpu
);
4481 void __init
page_alloc_init(void)
4483 hotcpu_notifier(page_alloc_cpu_notify
, 0);
4487 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
4488 * or min_free_kbytes changes.
4490 static void calculate_totalreserve_pages(void)
4492 struct pglist_data
*pgdat
;
4493 unsigned long reserve_pages
= 0;
4494 enum zone_type i
, j
;
4496 for_each_online_pgdat(pgdat
) {
4497 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4498 struct zone
*zone
= pgdat
->node_zones
+ i
;
4499 unsigned long max
= 0;
4501 /* Find valid and maximum lowmem_reserve in the zone */
4502 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
4503 if (zone
->lowmem_reserve
[j
] > max
)
4504 max
= zone
->lowmem_reserve
[j
];
4507 /* we treat the high watermark as reserved pages. */
4508 max
+= high_wmark_pages(zone
);
4510 if (max
> zone
->present_pages
)
4511 max
= zone
->present_pages
;
4512 reserve_pages
+= max
;
4515 totalreserve_pages
= reserve_pages
;
4519 * setup_per_zone_lowmem_reserve - called whenever
4520 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
4521 * has a correct pages reserved value, so an adequate number of
4522 * pages are left in the zone after a successful __alloc_pages().
4524 static void setup_per_zone_lowmem_reserve(void)
4526 struct pglist_data
*pgdat
;
4527 enum zone_type j
, idx
;
4529 for_each_online_pgdat(pgdat
) {
4530 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4531 struct zone
*zone
= pgdat
->node_zones
+ j
;
4532 unsigned long present_pages
= zone
->present_pages
;
4534 zone
->lowmem_reserve
[j
] = 0;
4538 struct zone
*lower_zone
;
4542 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
4543 sysctl_lowmem_reserve_ratio
[idx
] = 1;
4545 lower_zone
= pgdat
->node_zones
+ idx
;
4546 lower_zone
->lowmem_reserve
[j
] = present_pages
/
4547 sysctl_lowmem_reserve_ratio
[idx
];
4548 present_pages
+= lower_zone
->present_pages
;
4553 /* update totalreserve_pages */
4554 calculate_totalreserve_pages();
4558 * setup_per_zone_wmarks - called when min_free_kbytes changes
4559 * or when memory is hot-{added|removed}
4561 * Ensures that the watermark[min,low,high] values for each zone are set
4562 * correctly with respect to min_free_kbytes.
4564 void setup_per_zone_wmarks(void)
4566 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
4567 unsigned long lowmem_pages
= 0;
4569 unsigned long flags
;
4571 /* Calculate total number of !ZONE_HIGHMEM pages */
4572 for_each_zone(zone
) {
4573 if (!is_highmem(zone
))
4574 lowmem_pages
+= zone
->present_pages
;
4577 for_each_zone(zone
) {
4580 spin_lock_irqsave(&zone
->lock
, flags
);
4581 tmp
= (u64
)pages_min
* zone
->present_pages
;
4582 do_div(tmp
, lowmem_pages
);
4583 if (is_highmem(zone
)) {
4585 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
4586 * need highmem pages, so cap pages_min to a small
4589 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
4590 * deltas controls asynch page reclaim, and so should
4591 * not be capped for highmem.
4595 min_pages
= zone
->present_pages
/ 1024;
4596 if (min_pages
< SWAP_CLUSTER_MAX
)
4597 min_pages
= SWAP_CLUSTER_MAX
;
4598 if (min_pages
> 128)
4600 zone
->watermark
[WMARK_MIN
] = min_pages
;
4603 * If it's a lowmem zone, reserve a number of pages
4604 * proportionate to the zone's size.
4606 zone
->watermark
[WMARK_MIN
] = tmp
;
4609 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + (tmp
>> 2);
4610 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + (tmp
>> 1);
4611 setup_zone_migrate_reserve(zone
);
4612 spin_unlock_irqrestore(&zone
->lock
, flags
);
4615 /* update totalreserve_pages */
4616 calculate_totalreserve_pages();
4620 * The inactive anon list should be small enough that the VM never has to
4621 * do too much work, but large enough that each inactive page has a chance
4622 * to be referenced again before it is swapped out.
4624 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
4625 * INACTIVE_ANON pages on this zone's LRU, maintained by the
4626 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
4627 * the anonymous pages are kept on the inactive list.
4630 * memory ratio inactive anon
4631 * -------------------------------------
4640 void calculate_zone_inactive_ratio(struct zone
*zone
)
4642 unsigned int gb
, ratio
;
4644 /* Zone size in gigabytes */
4645 gb
= zone
->present_pages
>> (30 - PAGE_SHIFT
);
4647 ratio
= int_sqrt(10 * gb
);
4651 zone
->inactive_ratio
= ratio
;
4654 static void __init
setup_per_zone_inactive_ratio(void)
4659 calculate_zone_inactive_ratio(zone
);
4663 * Initialise min_free_kbytes.
4665 * For small machines we want it small (128k min). For large machines
4666 * we want it large (64MB max). But it is not linear, because network
4667 * bandwidth does not increase linearly with machine size. We use
4669 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
4670 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
4686 static int __init
init_per_zone_wmark_min(void)
4688 unsigned long lowmem_kbytes
;
4690 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
4692 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
4693 if (min_free_kbytes
< 128)
4694 min_free_kbytes
= 128;
4695 if (min_free_kbytes
> 65536)
4696 min_free_kbytes
= 65536;
4697 setup_per_zone_wmarks();
4698 setup_per_zone_lowmem_reserve();
4699 setup_per_zone_inactive_ratio();
4702 module_init(init_per_zone_wmark_min
)
4705 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
4706 * that we can call two helper functions whenever min_free_kbytes
4709 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
4710 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4712 proc_dointvec(table
, write
, file
, buffer
, length
, ppos
);
4714 setup_per_zone_wmarks();
4719 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
4720 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4725 rc
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4730 zone
->min_unmapped_pages
= (zone
->present_pages
*
4731 sysctl_min_unmapped_ratio
) / 100;
4735 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
4736 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4741 rc
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4746 zone
->min_slab_pages
= (zone
->present_pages
*
4747 sysctl_min_slab_ratio
) / 100;
4753 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
4754 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
4755 * whenever sysctl_lowmem_reserve_ratio changes.
4757 * The reserve ratio obviously has absolutely no relation with the
4758 * minimum watermarks. The lowmem reserve ratio can only make sense
4759 * if in function of the boot time zone sizes.
4761 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
4762 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4764 proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4765 setup_per_zone_lowmem_reserve();
4770 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
4771 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
4772 * can have before it gets flushed back to buddy allocator.
4775 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
4776 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4782 ret
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4783 if (!write
|| (ret
== -EINVAL
))
4785 for_each_populated_zone(zone
) {
4786 for_each_online_cpu(cpu
) {
4788 high
= zone
->present_pages
/ percpu_pagelist_fraction
;
4789 setup_pagelist_highmark(zone_pcp(zone
, cpu
), high
);
4795 int hashdist
= HASHDIST_DEFAULT
;
4798 static int __init
set_hashdist(char *str
)
4802 hashdist
= simple_strtoul(str
, &str
, 0);
4805 __setup("hashdist=", set_hashdist
);
4809 * allocate a large system hash table from bootmem
4810 * - it is assumed that the hash table must contain an exact power-of-2
4811 * quantity of entries
4812 * - limit is the number of hash buckets, not the total allocation size
4814 void *__init
alloc_large_system_hash(const char *tablename
,
4815 unsigned long bucketsize
,
4816 unsigned long numentries
,
4819 unsigned int *_hash_shift
,
4820 unsigned int *_hash_mask
,
4821 unsigned long limit
)
4823 unsigned long long max
= limit
;
4824 unsigned long log2qty
, size
;
4827 /* allow the kernel cmdline to have a say */
4829 /* round applicable memory size up to nearest megabyte */
4830 numentries
= nr_kernel_pages
;
4831 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
4832 numentries
>>= 20 - PAGE_SHIFT
;
4833 numentries
<<= 20 - PAGE_SHIFT
;
4835 /* limit to 1 bucket per 2^scale bytes of low memory */
4836 if (scale
> PAGE_SHIFT
)
4837 numentries
>>= (scale
- PAGE_SHIFT
);
4839 numentries
<<= (PAGE_SHIFT
- scale
);
4841 /* Make sure we've got at least a 0-order allocation.. */
4842 if (unlikely(flags
& HASH_SMALL
)) {
4843 /* Makes no sense without HASH_EARLY */
4844 WARN_ON(!(flags
& HASH_EARLY
));
4845 if (!(numentries
>> *_hash_shift
)) {
4846 numentries
= 1UL << *_hash_shift
;
4847 BUG_ON(!numentries
);
4849 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
4850 numentries
= PAGE_SIZE
/ bucketsize
;
4852 numentries
= roundup_pow_of_two(numentries
);
4854 /* limit allocation size to 1/16 total memory by default */
4856 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
4857 do_div(max
, bucketsize
);
4860 if (numentries
> max
)
4863 log2qty
= ilog2(numentries
);
4866 size
= bucketsize
<< log2qty
;
4867 if (flags
& HASH_EARLY
)
4868 table
= alloc_bootmem_nopanic(size
);
4870 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
4873 * If bucketsize is not a power-of-two, we may free
4874 * some pages at the end of hash table which
4875 * alloc_pages_exact() automatically does
4877 if (get_order(size
) < MAX_ORDER
) {
4878 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
4879 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
4882 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
4885 panic("Failed to allocate %s hash table\n", tablename
);
4887 printk(KERN_INFO
"%s hash table entries: %d (order: %d, %lu bytes)\n",
4890 ilog2(size
) - PAGE_SHIFT
,
4894 *_hash_shift
= log2qty
;
4896 *_hash_mask
= (1 << log2qty
) - 1;
4901 /* Return a pointer to the bitmap storing bits affecting a block of pages */
4902 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
4905 #ifdef CONFIG_SPARSEMEM
4906 return __pfn_to_section(pfn
)->pageblock_flags
;
4908 return zone
->pageblock_flags
;
4909 #endif /* CONFIG_SPARSEMEM */
4912 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
4914 #ifdef CONFIG_SPARSEMEM
4915 pfn
&= (PAGES_PER_SECTION
-1);
4916 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
4918 pfn
= pfn
- zone
->zone_start_pfn
;
4919 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
4920 #endif /* CONFIG_SPARSEMEM */
4924 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4925 * @page: The page within the block of interest
4926 * @start_bitidx: The first bit of interest to retrieve
4927 * @end_bitidx: The last bit of interest
4928 * returns pageblock_bits flags
4930 unsigned long get_pageblock_flags_group(struct page
*page
,
4931 int start_bitidx
, int end_bitidx
)
4934 unsigned long *bitmap
;
4935 unsigned long pfn
, bitidx
;
4936 unsigned long flags
= 0;
4937 unsigned long value
= 1;
4939 zone
= page_zone(page
);
4940 pfn
= page_to_pfn(page
);
4941 bitmap
= get_pageblock_bitmap(zone
, pfn
);
4942 bitidx
= pfn_to_bitidx(zone
, pfn
);
4944 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
4945 if (test_bit(bitidx
+ start_bitidx
, bitmap
))
4952 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
4953 * @page: The page within the block of interest
4954 * @start_bitidx: The first bit of interest
4955 * @end_bitidx: The last bit of interest
4956 * @flags: The flags to set
4958 void set_pageblock_flags_group(struct page
*page
, unsigned long flags
,
4959 int start_bitidx
, int end_bitidx
)
4962 unsigned long *bitmap
;
4963 unsigned long pfn
, bitidx
;
4964 unsigned long value
= 1;
4966 zone
= page_zone(page
);
4967 pfn
= page_to_pfn(page
);
4968 bitmap
= get_pageblock_bitmap(zone
, pfn
);
4969 bitidx
= pfn_to_bitidx(zone
, pfn
);
4970 VM_BUG_ON(pfn
< zone
->zone_start_pfn
);
4971 VM_BUG_ON(pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
);
4973 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
4975 __set_bit(bitidx
+ start_bitidx
, bitmap
);
4977 __clear_bit(bitidx
+ start_bitidx
, bitmap
);
4981 * This is designed as sub function...plz see page_isolation.c also.
4982 * set/clear page block's type to be ISOLATE.
4983 * page allocater never alloc memory from ISOLATE block.
4986 int set_migratetype_isolate(struct page
*page
)
4989 unsigned long flags
;
4993 zone
= page_zone(page
);
4994 zone_idx
= zone_idx(zone
);
4995 spin_lock_irqsave(&zone
->lock
, flags
);
4997 * In future, more migrate types will be able to be isolation target.
4999 if (get_pageblock_migratetype(page
) != MIGRATE_MOVABLE
&&
5000 zone_idx
!= ZONE_MOVABLE
)
5002 set_pageblock_migratetype(page
, MIGRATE_ISOLATE
);
5003 move_freepages_block(zone
, page
, MIGRATE_ISOLATE
);
5006 spin_unlock_irqrestore(&zone
->lock
, flags
);
5012 void unset_migratetype_isolate(struct page
*page
)
5015 unsigned long flags
;
5016 zone
= page_zone(page
);
5017 spin_lock_irqsave(&zone
->lock
, flags
);
5018 if (get_pageblock_migratetype(page
) != MIGRATE_ISOLATE
)
5020 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
5021 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
5023 spin_unlock_irqrestore(&zone
->lock
, flags
);
5026 #ifdef CONFIG_MEMORY_HOTREMOVE
5028 * All pages in the range must be isolated before calling this.
5031 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
5037 unsigned long flags
;
5038 /* find the first valid pfn */
5039 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
5044 zone
= page_zone(pfn_to_page(pfn
));
5045 spin_lock_irqsave(&zone
->lock
, flags
);
5047 while (pfn
< end_pfn
) {
5048 if (!pfn_valid(pfn
)) {
5052 page
= pfn_to_page(pfn
);
5053 BUG_ON(page_count(page
));
5054 BUG_ON(!PageBuddy(page
));
5055 order
= page_order(page
);
5056 #ifdef CONFIG_DEBUG_VM
5057 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
5058 pfn
, 1 << order
, end_pfn
);
5060 list_del(&page
->lru
);
5061 rmv_page_order(page
);
5062 zone
->free_area
[order
].nr_free
--;
5063 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
5065 for (i
= 0; i
< (1 << order
); i
++)
5066 SetPageReserved((page
+i
));
5067 pfn
+= (1 << order
);
5069 spin_unlock_irqrestore(&zone
->lock
, flags
);