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 int percpu_pagelist_fraction
;
76 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
78 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
79 int pageblock_order __read_mostly
;
82 static void __free_pages_ok(struct page
*page
, unsigned int order
);
85 * results with 256, 32 in the lowmem_reserve sysctl:
86 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
87 * 1G machine -> (16M dma, 784M normal, 224M high)
88 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
89 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
90 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
92 * TBD: should special case ZONE_DMA32 machines here - in those we normally
93 * don't need any ZONE_NORMAL reservation
95 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
96 #ifdef CONFIG_ZONE_DMA
99 #ifdef CONFIG_ZONE_DMA32
102 #ifdef CONFIG_HIGHMEM
108 EXPORT_SYMBOL(totalram_pages
);
110 static char * const zone_names
[MAX_NR_ZONES
] = {
111 #ifdef CONFIG_ZONE_DMA
114 #ifdef CONFIG_ZONE_DMA32
118 #ifdef CONFIG_HIGHMEM
124 int min_free_kbytes
= 1024;
125 int min_free_order_shift
= 1;
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
;
238 /* Don't complain about poisoned pages */
239 if (PageHWPoison(page
)) {
240 __ClearPageBuddy(page
);
245 * Allow a burst of 60 reports, then keep quiet for that minute;
246 * or allow a steady drip of one report per second.
248 if (nr_shown
== 60) {
249 if (time_before(jiffies
, resume
)) {
255 "BUG: Bad page state: %lu messages suppressed\n",
262 resume
= jiffies
+ 60 * HZ
;
264 printk(KERN_ALERT
"BUG: Bad page state in process %s pfn:%05lx\n",
265 current
->comm
, page_to_pfn(page
));
267 "page:%p flags:%p count:%d mapcount:%d mapping:%p index:%lx\n",
268 page
, (void *)page
->flags
, page_count(page
),
269 page_mapcount(page
), page
->mapping
, page
->index
);
273 /* Leave bad fields for debug, except PageBuddy could make trouble */
274 __ClearPageBuddy(page
);
275 add_taint(TAINT_BAD_PAGE
);
279 * Higher-order pages are called "compound pages". They are structured thusly:
281 * The first PAGE_SIZE page is called the "head page".
283 * The remaining PAGE_SIZE pages are called "tail pages".
285 * All pages have PG_compound set. All pages have their ->private pointing at
286 * the head page (even the head page has this).
288 * The first tail page's ->lru.next holds the address of the compound page's
289 * put_page() function. Its ->lru.prev holds the order of allocation.
290 * This usage means that zero-order pages may not be compound.
293 static void free_compound_page(struct page
*page
)
295 __free_pages_ok(page
, compound_order(page
));
298 void prep_compound_page(struct page
*page
, unsigned long order
)
301 int nr_pages
= 1 << order
;
303 set_compound_page_dtor(page
, free_compound_page
);
304 set_compound_order(page
, order
);
306 for (i
= 1; i
< nr_pages
; i
++) {
307 struct page
*p
= page
+ i
;
310 p
->first_page
= page
;
314 static int destroy_compound_page(struct page
*page
, unsigned long order
)
317 int nr_pages
= 1 << order
;
320 if (unlikely(compound_order(page
) != order
) ||
321 unlikely(!PageHead(page
))) {
326 __ClearPageHead(page
);
328 for (i
= 1; i
< nr_pages
; i
++) {
329 struct page
*p
= page
+ i
;
331 if (unlikely(!PageTail(p
) || (p
->first_page
!= page
))) {
341 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
346 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
347 * and __GFP_HIGHMEM from hard or soft interrupt context.
349 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
350 for (i
= 0; i
< (1 << order
); i
++)
351 clear_highpage(page
+ i
);
354 static inline void set_page_order(struct page
*page
, int order
)
356 set_page_private(page
, order
);
357 __SetPageBuddy(page
);
360 static inline void rmv_page_order(struct page
*page
)
362 __ClearPageBuddy(page
);
363 set_page_private(page
, 0);
367 * Locate the struct page for both the matching buddy in our
368 * pair (buddy1) and the combined O(n+1) page they form (page).
370 * 1) Any buddy B1 will have an order O twin B2 which satisfies
371 * the following equation:
373 * For example, if the starting buddy (buddy2) is #8 its order
375 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
377 * 2) Any buddy B will have an order O+1 parent P which
378 * satisfies the following equation:
381 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
383 static inline struct page
*
384 __page_find_buddy(struct page
*page
, unsigned long page_idx
, unsigned int order
)
386 unsigned long buddy_idx
= page_idx
^ (1 << order
);
388 return page
+ (buddy_idx
- page_idx
);
391 static inline unsigned long
392 __find_combined_index(unsigned long page_idx
, unsigned int order
)
394 return (page_idx
& ~(1 << order
));
398 * This function checks whether a page is free && is the buddy
399 * we can do coalesce a page and its buddy if
400 * (a) the buddy is not in a hole &&
401 * (b) the buddy is in the buddy system &&
402 * (c) a page and its buddy have the same order &&
403 * (d) a page and its buddy are in the same zone.
405 * For recording whether a page is in the buddy system, we use PG_buddy.
406 * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
408 * For recording page's order, we use page_private(page).
410 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
413 if (!pfn_valid_within(page_to_pfn(buddy
)))
416 if (page_zone_id(page
) != page_zone_id(buddy
))
419 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
420 VM_BUG_ON(page_count(buddy
) != 0);
427 * Freeing function for a buddy system allocator.
429 * The concept of a buddy system is to maintain direct-mapped table
430 * (containing bit values) for memory blocks of various "orders".
431 * The bottom level table contains the map for the smallest allocatable
432 * units of memory (here, pages), and each level above it describes
433 * pairs of units from the levels below, hence, "buddies".
434 * At a high level, all that happens here is marking the table entry
435 * at the bottom level available, and propagating the changes upward
436 * as necessary, plus some accounting needed to play nicely with other
437 * parts of the VM system.
438 * At each level, we keep a list of pages, which are heads of continuous
439 * free pages of length of (1 << order) and marked with PG_buddy. Page's
440 * order is recorded in page_private(page) field.
441 * So when we are allocating or freeing one, we can derive the state of the
442 * other. That is, if we allocate a small block, and both were
443 * free, the remainder of the region must be split into blocks.
444 * If a block is freed, and its buddy is also free, then this
445 * triggers coalescing into a block of larger size.
450 static inline void __free_one_page(struct page
*page
,
451 struct zone
*zone
, unsigned int order
,
454 unsigned long page_idx
;
456 if (unlikely(PageCompound(page
)))
457 if (unlikely(destroy_compound_page(page
, order
)))
460 VM_BUG_ON(migratetype
== -1);
462 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
464 VM_BUG_ON(page_idx
& ((1 << order
) - 1));
465 VM_BUG_ON(bad_range(zone
, page
));
467 while (order
< MAX_ORDER
-1) {
468 unsigned long combined_idx
;
471 buddy
= __page_find_buddy(page
, page_idx
, order
);
472 if (!page_is_buddy(page
, buddy
, order
))
475 /* Our buddy is free, merge with it and move up one order. */
476 list_del(&buddy
->lru
);
477 zone
->free_area
[order
].nr_free
--;
478 rmv_page_order(buddy
);
479 combined_idx
= __find_combined_index(page_idx
, order
);
480 page
= page
+ (combined_idx
- page_idx
);
481 page_idx
= combined_idx
;
484 set_page_order(page
, order
);
486 &zone
->free_area
[order
].free_list
[migratetype
]);
487 zone
->free_area
[order
].nr_free
++;
490 #ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT
492 * free_page_mlock() -- clean up attempts to free and mlocked() page.
493 * Page should not be on lru, so no need to fix that up.
494 * free_pages_check() will verify...
496 static inline void free_page_mlock(struct page
*page
)
498 __dec_zone_page_state(page
, NR_MLOCK
);
499 __count_vm_event(UNEVICTABLE_MLOCKFREED
);
502 static void free_page_mlock(struct page
*page
) { }
505 static inline int free_pages_check(struct page
*page
)
507 if (unlikely(page_mapcount(page
) |
508 (page
->mapping
!= NULL
) |
509 (atomic_read(&page
->_count
) != 0) |
510 (page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
))) {
514 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
515 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
520 * Frees a number of pages from the PCP lists
521 * Assumes all pages on list are in same zone, and of same order.
522 * count is the number of pages to free.
524 * If the zone was previously in an "all pages pinned" state then look to
525 * see if this freeing clears that state.
527 * And clear the zone's pages_scanned counter, to hold off the "all pages are
528 * pinned" detection logic.
530 static void free_pcppages_bulk(struct zone
*zone
, int count
,
531 struct per_cpu_pages
*pcp
)
536 spin_lock(&zone
->lock
);
537 zone_clear_flag(zone
, ZONE_ALL_UNRECLAIMABLE
);
538 zone
->pages_scanned
= 0;
540 __mod_zone_page_state(zone
, NR_FREE_PAGES
, count
);
543 struct list_head
*list
;
546 * Remove pages from lists in a round-robin fashion. A
547 * batch_free count is maintained that is incremented when an
548 * empty list is encountered. This is so more pages are freed
549 * off fuller lists instead of spinning excessively around empty
554 if (++migratetype
== MIGRATE_PCPTYPES
)
556 list
= &pcp
->lists
[migratetype
];
557 } while (list_empty(list
));
560 page
= list_entry(list
->prev
, struct page
, lru
);
561 /* must delete as __free_one_page list manipulates */
562 list_del(&page
->lru
);
563 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
564 __free_one_page(page
, zone
, 0, page_private(page
));
565 trace_mm_page_pcpu_drain(page
, 0, page_private(page
));
566 } while (--count
&& --batch_free
&& !list_empty(list
));
568 spin_unlock(&zone
->lock
);
571 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
,
574 spin_lock(&zone
->lock
);
575 zone_clear_flag(zone
, ZONE_ALL_UNRECLAIMABLE
);
576 zone
->pages_scanned
= 0;
578 __mod_zone_page_state(zone
, NR_FREE_PAGES
, 1 << order
);
579 __free_one_page(page
, zone
, order
, migratetype
);
580 spin_unlock(&zone
->lock
);
583 static void __free_pages_ok(struct page
*page
, unsigned int order
)
588 int wasMlocked
= __TestClearPageMlocked(page
);
590 kmemcheck_free_shadow(page
, order
);
592 for (i
= 0 ; i
< (1 << order
) ; ++i
)
593 bad
+= free_pages_check(page
+ i
);
597 if (!PageHighMem(page
)) {
598 debug_check_no_locks_freed(page_address(page
),PAGE_SIZE
<<order
);
599 debug_check_no_obj_freed(page_address(page
),
602 arch_free_page(page
, order
);
603 kernel_map_pages(page
, 1 << order
, 0);
605 local_irq_save(flags
);
606 if (unlikely(wasMlocked
))
607 free_page_mlock(page
);
608 __count_vm_events(PGFREE
, 1 << order
);
609 free_one_page(page_zone(page
), page
, order
,
610 get_pageblock_migratetype(page
));
611 local_irq_restore(flags
);
615 * permit the bootmem allocator to evade page validation on high-order frees
617 void __meminit
__free_pages_bootmem(struct page
*page
, unsigned int order
)
620 __ClearPageReserved(page
);
621 set_page_count(page
, 0);
622 set_page_refcounted(page
);
628 for (loop
= 0; loop
< BITS_PER_LONG
; loop
++) {
629 struct page
*p
= &page
[loop
];
631 if (loop
+ 1 < BITS_PER_LONG
)
633 __ClearPageReserved(p
);
634 set_page_count(p
, 0);
637 set_page_refcounted(page
);
638 __free_pages(page
, order
);
644 * The order of subdivision here is critical for the IO subsystem.
645 * Please do not alter this order without good reasons and regression
646 * testing. Specifically, as large blocks of memory are subdivided,
647 * the order in which smaller blocks are delivered depends on the order
648 * they're subdivided in this function. This is the primary factor
649 * influencing the order in which pages are delivered to the IO
650 * subsystem according to empirical testing, and this is also justified
651 * by considering the behavior of a buddy system containing a single
652 * large block of memory acted on by a series of small allocations.
653 * This behavior is a critical factor in sglist merging's success.
657 static inline void expand(struct zone
*zone
, struct page
*page
,
658 int low
, int high
, struct free_area
*area
,
661 unsigned long size
= 1 << high
;
667 VM_BUG_ON(bad_range(zone
, &page
[size
]));
668 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
670 set_page_order(&page
[size
], high
);
675 * This page is about to be returned from the page allocator
677 static inline int check_new_page(struct page
*page
)
679 if (unlikely(page_mapcount(page
) |
680 (page
->mapping
!= NULL
) |
681 (atomic_read(&page
->_count
) != 0) |
682 (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
))) {
689 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
693 for (i
= 0; i
< (1 << order
); i
++) {
694 struct page
*p
= page
+ i
;
695 if (unlikely(check_new_page(p
)))
699 set_page_private(page
, 0);
700 set_page_refcounted(page
);
702 arch_alloc_page(page
, order
);
703 kernel_map_pages(page
, 1 << order
, 1);
705 if (gfp_flags
& __GFP_ZERO
)
706 prep_zero_page(page
, order
, gfp_flags
);
708 if (order
&& (gfp_flags
& __GFP_COMP
))
709 prep_compound_page(page
, order
);
715 * Go through the free lists for the given migratetype and remove
716 * the smallest available page from the freelists
719 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
722 unsigned int current_order
;
723 struct free_area
* area
;
726 /* Find a page of the appropriate size in the preferred list */
727 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
728 area
= &(zone
->free_area
[current_order
]);
729 if (list_empty(&area
->free_list
[migratetype
]))
732 page
= list_entry(area
->free_list
[migratetype
].next
,
734 list_del(&page
->lru
);
735 rmv_page_order(page
);
737 expand(zone
, page
, order
, current_order
, area
, migratetype
);
746 * This array describes the order lists are fallen back to when
747 * the free lists for the desirable migrate type are depleted
749 static int fallbacks
[MIGRATE_TYPES
][MIGRATE_TYPES
-1] = {
750 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
751 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
752 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
753 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
, MIGRATE_RESERVE
, MIGRATE_RESERVE
}, /* Never used */
757 * Move the free pages in a range to the free lists of the requested type.
758 * Note that start_page and end_pages are not aligned on a pageblock
759 * boundary. If alignment is required, use move_freepages_block()
761 static int move_freepages(struct zone
*zone
,
762 struct page
*start_page
, struct page
*end_page
,
769 #ifndef CONFIG_HOLES_IN_ZONE
771 * page_zone is not safe to call in this context when
772 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
773 * anyway as we check zone boundaries in move_freepages_block().
774 * Remove at a later date when no bug reports exist related to
775 * grouping pages by mobility
777 BUG_ON(page_zone(start_page
) != page_zone(end_page
));
780 for (page
= start_page
; page
<= end_page
;) {
781 /* Make sure we are not inadvertently changing nodes */
782 VM_BUG_ON(page_to_nid(page
) != zone_to_nid(zone
));
784 if (!pfn_valid_within(page_to_pfn(page
))) {
789 if (!PageBuddy(page
)) {
794 order
= page_order(page
);
795 list_del(&page
->lru
);
797 &zone
->free_area
[order
].free_list
[migratetype
]);
799 pages_moved
+= 1 << order
;
805 static int move_freepages_block(struct zone
*zone
, struct page
*page
,
808 unsigned long start_pfn
, end_pfn
;
809 struct page
*start_page
, *end_page
;
811 start_pfn
= page_to_pfn(page
);
812 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
813 start_page
= pfn_to_page(start_pfn
);
814 end_page
= start_page
+ pageblock_nr_pages
- 1;
815 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
817 /* Do not cross zone boundaries */
818 if (start_pfn
< zone
->zone_start_pfn
)
820 if (end_pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
823 return move_freepages(zone
, start_page
, end_page
, migratetype
);
826 static void change_pageblock_range(struct page
*pageblock_page
,
827 int start_order
, int migratetype
)
829 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
831 while (nr_pageblocks
--) {
832 set_pageblock_migratetype(pageblock_page
, migratetype
);
833 pageblock_page
+= pageblock_nr_pages
;
837 /* Remove an element from the buddy allocator from the fallback list */
838 static inline struct page
*
839 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
)
841 struct free_area
* area
;
846 /* Find the largest possible block of pages in the other list */
847 for (current_order
= MAX_ORDER
-1; current_order
>= order
;
849 for (i
= 0; i
< MIGRATE_TYPES
- 1; i
++) {
850 migratetype
= fallbacks
[start_migratetype
][i
];
852 /* MIGRATE_RESERVE handled later if necessary */
853 if (migratetype
== MIGRATE_RESERVE
)
856 area
= &(zone
->free_area
[current_order
]);
857 if (list_empty(&area
->free_list
[migratetype
]))
860 page
= list_entry(area
->free_list
[migratetype
].next
,
865 * If breaking a large block of pages, move all free
866 * pages to the preferred allocation list. If falling
867 * back for a reclaimable kernel allocation, be more
868 * agressive about taking ownership of free pages
870 if (unlikely(current_order
>= (pageblock_order
>> 1)) ||
871 start_migratetype
== MIGRATE_RECLAIMABLE
||
872 page_group_by_mobility_disabled
) {
874 pages
= move_freepages_block(zone
, page
,
877 /* Claim the whole block if over half of it is free */
878 if (pages
>= (1 << (pageblock_order
-1)) ||
879 page_group_by_mobility_disabled
)
880 set_pageblock_migratetype(page
,
883 migratetype
= start_migratetype
;
886 /* Remove the page from the freelists */
887 list_del(&page
->lru
);
888 rmv_page_order(page
);
890 /* Take ownership for orders >= pageblock_order */
891 if (current_order
>= pageblock_order
)
892 change_pageblock_range(page
, current_order
,
895 expand(zone
, page
, order
, current_order
, area
, migratetype
);
897 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
898 start_migratetype
, migratetype
);
908 * Do the hard work of removing an element from the buddy allocator.
909 * Call me with the zone->lock already held.
911 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
917 page
= __rmqueue_smallest(zone
, order
, migratetype
);
919 if (unlikely(!page
) && migratetype
!= MIGRATE_RESERVE
) {
920 page
= __rmqueue_fallback(zone
, order
, migratetype
);
923 * Use MIGRATE_RESERVE rather than fail an allocation. goto
924 * is used because __rmqueue_smallest is an inline function
925 * and we want just one call site
928 migratetype
= MIGRATE_RESERVE
;
933 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
938 * Obtain a specified number of elements from the buddy allocator, all under
939 * a single hold of the lock, for efficiency. Add them to the supplied list.
940 * Returns the number of new pages which were placed at *list.
942 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
943 unsigned long count
, struct list_head
*list
,
944 int migratetype
, int cold
)
948 spin_lock(&zone
->lock
);
949 for (i
= 0; i
< count
; ++i
) {
950 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
951 if (unlikely(page
== NULL
))
955 * Split buddy pages returned by expand() are received here
956 * in physical page order. The page is added to the callers and
957 * list and the list head then moves forward. From the callers
958 * perspective, the linked list is ordered by page number in
959 * some conditions. This is useful for IO devices that can
960 * merge IO requests if the physical pages are ordered
963 if (likely(cold
== 0))
964 list_add(&page
->lru
, list
);
966 list_add_tail(&page
->lru
, list
);
967 set_page_private(page
, migratetype
);
970 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
971 spin_unlock(&zone
->lock
);
977 * Called from the vmstat counter updater to drain pagesets of this
978 * currently executing processor on remote nodes after they have
981 * Note that this function must be called with the thread pinned to
982 * a single processor.
984 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
989 local_irq_save(flags
);
990 if (pcp
->count
>= pcp
->batch
)
991 to_drain
= pcp
->batch
;
993 to_drain
= pcp
->count
;
994 free_pcppages_bulk(zone
, to_drain
, pcp
);
995 pcp
->count
-= to_drain
;
996 local_irq_restore(flags
);
1001 * Drain pages of the indicated processor.
1003 * The processor must either be the current processor and the
1004 * thread pinned to the current processor or a processor that
1007 static void drain_pages(unsigned int cpu
)
1009 unsigned long flags
;
1012 for_each_populated_zone(zone
) {
1013 struct per_cpu_pageset
*pset
;
1014 struct per_cpu_pages
*pcp
;
1016 pset
= zone_pcp(zone
, cpu
);
1019 local_irq_save(flags
);
1020 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1022 local_irq_restore(flags
);
1027 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1029 void drain_local_pages(void *arg
)
1031 drain_pages(smp_processor_id());
1035 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
1037 void drain_all_pages(void)
1039 on_each_cpu(drain_local_pages
, NULL
, 1);
1042 #ifdef CONFIG_HIBERNATION
1044 void mark_free_pages(struct zone
*zone
)
1046 unsigned long pfn
, max_zone_pfn
;
1047 unsigned long flags
;
1049 struct list_head
*curr
;
1051 if (!zone
->spanned_pages
)
1054 spin_lock_irqsave(&zone
->lock
, flags
);
1056 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
1057 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1058 if (pfn_valid(pfn
)) {
1059 struct page
*page
= pfn_to_page(pfn
);
1061 if (!swsusp_page_is_forbidden(page
))
1062 swsusp_unset_page_free(page
);
1065 for_each_migratetype_order(order
, t
) {
1066 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
1069 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
1070 for (i
= 0; i
< (1UL << order
); i
++)
1071 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
1074 spin_unlock_irqrestore(&zone
->lock
, flags
);
1076 #endif /* CONFIG_PM */
1079 * Free a 0-order page
1081 static void free_hot_cold_page(struct page
*page
, int cold
)
1083 struct zone
*zone
= page_zone(page
);
1084 struct per_cpu_pages
*pcp
;
1085 unsigned long flags
;
1087 int wasMlocked
= __TestClearPageMlocked(page
);
1089 kmemcheck_free_shadow(page
, 0);
1092 page
->mapping
= NULL
;
1093 if (free_pages_check(page
))
1096 if (!PageHighMem(page
)) {
1097 debug_check_no_locks_freed(page_address(page
), PAGE_SIZE
);
1098 debug_check_no_obj_freed(page_address(page
), PAGE_SIZE
);
1100 arch_free_page(page
, 0);
1101 kernel_map_pages(page
, 1, 0);
1103 pcp
= &zone_pcp(zone
, get_cpu())->pcp
;
1104 migratetype
= get_pageblock_migratetype(page
);
1105 set_page_private(page
, migratetype
);
1106 local_irq_save(flags
);
1107 if (unlikely(wasMlocked
))
1108 free_page_mlock(page
);
1109 __count_vm_event(PGFREE
);
1112 * We only track unmovable, reclaimable and movable on pcp lists.
1113 * Free ISOLATE pages back to the allocator because they are being
1114 * offlined but treat RESERVE as movable pages so we can get those
1115 * areas back if necessary. Otherwise, we may have to free
1116 * excessively into the page allocator
1118 if (migratetype
>= MIGRATE_PCPTYPES
) {
1119 if (unlikely(migratetype
== MIGRATE_ISOLATE
)) {
1120 free_one_page(zone
, page
, 0, migratetype
);
1123 migratetype
= MIGRATE_MOVABLE
;
1127 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
1129 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
1131 if (pcp
->count
>= pcp
->high
) {
1132 free_pcppages_bulk(zone
, pcp
->batch
, pcp
);
1133 pcp
->count
-= pcp
->batch
;
1137 local_irq_restore(flags
);
1141 void free_hot_page(struct page
*page
)
1143 trace_mm_page_free_direct(page
, 0);
1144 free_hot_cold_page(page
, 0);
1148 * split_page takes a non-compound higher-order page, and splits it into
1149 * n (1<<order) sub-pages: page[0..n]
1150 * Each sub-page must be freed individually.
1152 * Note: this is probably too low level an operation for use in drivers.
1153 * Please consult with lkml before using this in your driver.
1155 void split_page(struct page
*page
, unsigned int order
)
1159 VM_BUG_ON(PageCompound(page
));
1160 VM_BUG_ON(!page_count(page
));
1162 #ifdef CONFIG_KMEMCHECK
1164 * Split shadow pages too, because free(page[0]) would
1165 * otherwise free the whole shadow.
1167 if (kmemcheck_page_is_tracked(page
))
1168 split_page(virt_to_page(page
[0].shadow
), order
);
1171 for (i
= 1; i
< (1 << order
); i
++)
1172 set_page_refcounted(page
+ i
);
1176 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1177 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1181 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
1182 struct zone
*zone
, int order
, gfp_t gfp_flags
,
1185 unsigned long flags
;
1187 int cold
= !!(gfp_flags
& __GFP_COLD
);
1192 if (likely(order
== 0)) {
1193 struct per_cpu_pages
*pcp
;
1194 struct list_head
*list
;
1196 pcp
= &zone_pcp(zone
, cpu
)->pcp
;
1197 list
= &pcp
->lists
[migratetype
];
1198 local_irq_save(flags
);
1199 if (list_empty(list
)) {
1200 pcp
->count
+= rmqueue_bulk(zone
, 0,
1203 if (unlikely(list_empty(list
)))
1208 page
= list_entry(list
->prev
, struct page
, lru
);
1210 page
= list_entry(list
->next
, struct page
, lru
);
1212 list_del(&page
->lru
);
1215 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
1217 * __GFP_NOFAIL is not to be used in new code.
1219 * All __GFP_NOFAIL callers should be fixed so that they
1220 * properly detect and handle allocation failures.
1222 * We most definitely don't want callers attempting to
1223 * allocate greater than order-1 page units with
1226 WARN_ON_ONCE(order
> 1);
1228 spin_lock_irqsave(&zone
->lock
, flags
);
1229 page
= __rmqueue(zone
, order
, migratetype
);
1230 spin_unlock(&zone
->lock
);
1233 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(1 << order
));
1236 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
1237 zone_statistics(preferred_zone
, zone
);
1238 local_irq_restore(flags
);
1241 VM_BUG_ON(bad_range(zone
, page
));
1242 if (prep_new_page(page
, order
, gfp_flags
))
1247 local_irq_restore(flags
);
1252 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
1253 #define ALLOC_WMARK_MIN WMARK_MIN
1254 #define ALLOC_WMARK_LOW WMARK_LOW
1255 #define ALLOC_WMARK_HIGH WMARK_HIGH
1256 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
1258 /* Mask to get the watermark bits */
1259 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
1261 #define ALLOC_HARDER 0x10 /* try to alloc harder */
1262 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
1263 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
1265 #ifdef CONFIG_FAIL_PAGE_ALLOC
1267 static struct fail_page_alloc_attr
{
1268 struct fault_attr attr
;
1270 u32 ignore_gfp_highmem
;
1271 u32 ignore_gfp_wait
;
1274 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1276 struct dentry
*ignore_gfp_highmem_file
;
1277 struct dentry
*ignore_gfp_wait_file
;
1278 struct dentry
*min_order_file
;
1280 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1282 } fail_page_alloc
= {
1283 .attr
= FAULT_ATTR_INITIALIZER
,
1284 .ignore_gfp_wait
= 1,
1285 .ignore_gfp_highmem
= 1,
1289 static int __init
setup_fail_page_alloc(char *str
)
1291 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
1293 __setup("fail_page_alloc=", setup_fail_page_alloc
);
1295 static int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1297 if (order
< fail_page_alloc
.min_order
)
1299 if (gfp_mask
& __GFP_NOFAIL
)
1301 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
1303 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
1306 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
1309 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1311 static int __init
fail_page_alloc_debugfs(void)
1313 mode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
1317 err
= init_fault_attr_dentries(&fail_page_alloc
.attr
,
1321 dir
= fail_page_alloc
.attr
.dentries
.dir
;
1323 fail_page_alloc
.ignore_gfp_wait_file
=
1324 debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
1325 &fail_page_alloc
.ignore_gfp_wait
);
1327 fail_page_alloc
.ignore_gfp_highmem_file
=
1328 debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
1329 &fail_page_alloc
.ignore_gfp_highmem
);
1330 fail_page_alloc
.min_order_file
=
1331 debugfs_create_u32("min-order", mode
, dir
,
1332 &fail_page_alloc
.min_order
);
1334 if (!fail_page_alloc
.ignore_gfp_wait_file
||
1335 !fail_page_alloc
.ignore_gfp_highmem_file
||
1336 !fail_page_alloc
.min_order_file
) {
1338 debugfs_remove(fail_page_alloc
.ignore_gfp_wait_file
);
1339 debugfs_remove(fail_page_alloc
.ignore_gfp_highmem_file
);
1340 debugfs_remove(fail_page_alloc
.min_order_file
);
1341 cleanup_fault_attr_dentries(&fail_page_alloc
.attr
);
1347 late_initcall(fail_page_alloc_debugfs
);
1349 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1351 #else /* CONFIG_FAIL_PAGE_ALLOC */
1353 static inline int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1358 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1361 * Return 1 if free pages are above 'mark'. This takes into account the order
1362 * of the allocation.
1364 int zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1365 int classzone_idx
, int alloc_flags
)
1367 /* free_pages my go negative - that's OK */
1369 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
) - (1 << order
) + 1;
1372 if (alloc_flags
& ALLOC_HIGH
)
1374 if (alloc_flags
& ALLOC_HARDER
)
1377 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
1379 for (o
= 0; o
< order
; o
++) {
1380 /* At the next order, this order's pages become unavailable */
1381 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1383 /* Require fewer higher order pages to be free */
1384 min
>>= min_free_order_shift
;
1386 if (free_pages
<= min
)
1394 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1395 * skip over zones that are not allowed by the cpuset, or that have
1396 * been recently (in last second) found to be nearly full. See further
1397 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1398 * that have to skip over a lot of full or unallowed zones.
1400 * If the zonelist cache is present in the passed in zonelist, then
1401 * returns a pointer to the allowed node mask (either the current
1402 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1404 * If the zonelist cache is not available for this zonelist, does
1405 * nothing and returns NULL.
1407 * If the fullzones BITMAP in the zonelist cache is stale (more than
1408 * a second since last zap'd) then we zap it out (clear its bits.)
1410 * We hold off even calling zlc_setup, until after we've checked the
1411 * first zone in the zonelist, on the theory that most allocations will
1412 * be satisfied from that first zone, so best to examine that zone as
1413 * quickly as we can.
1415 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1417 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1418 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1420 zlc
= zonelist
->zlcache_ptr
;
1424 if (time_after(jiffies
, zlc
->last_full_zap
+ HZ
)) {
1425 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1426 zlc
->last_full_zap
= jiffies
;
1429 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1430 &cpuset_current_mems_allowed
:
1431 &node_states
[N_HIGH_MEMORY
];
1432 return allowednodes
;
1436 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1437 * if it is worth looking at further for free memory:
1438 * 1) Check that the zone isn't thought to be full (doesn't have its
1439 * bit set in the zonelist_cache fullzones BITMAP).
1440 * 2) Check that the zones node (obtained from the zonelist_cache
1441 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1442 * Return true (non-zero) if zone is worth looking at further, or
1443 * else return false (zero) if it is not.
1445 * This check -ignores- the distinction between various watermarks,
1446 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1447 * found to be full for any variation of these watermarks, it will
1448 * be considered full for up to one second by all requests, unless
1449 * we are so low on memory on all allowed nodes that we are forced
1450 * into the second scan of the zonelist.
1452 * In the second scan we ignore this zonelist cache and exactly
1453 * apply the watermarks to all zones, even it is slower to do so.
1454 * We are low on memory in the second scan, and should leave no stone
1455 * unturned looking for a free page.
1457 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1458 nodemask_t
*allowednodes
)
1460 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1461 int i
; /* index of *z in zonelist zones */
1462 int n
; /* node that zone *z is on */
1464 zlc
= zonelist
->zlcache_ptr
;
1468 i
= z
- zonelist
->_zonerefs
;
1471 /* This zone is worth trying if it is allowed but not full */
1472 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1476 * Given 'z' scanning a zonelist, set the corresponding bit in
1477 * zlc->fullzones, so that subsequent attempts to allocate a page
1478 * from that zone don't waste time re-examining it.
1480 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1482 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1483 int i
; /* index of *z in zonelist zones */
1485 zlc
= zonelist
->zlcache_ptr
;
1489 i
= z
- zonelist
->_zonerefs
;
1491 set_bit(i
, zlc
->fullzones
);
1494 #else /* CONFIG_NUMA */
1496 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1501 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1502 nodemask_t
*allowednodes
)
1507 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1510 #endif /* CONFIG_NUMA */
1513 * get_page_from_freelist goes through the zonelist trying to allocate
1516 static struct page
*
1517 get_page_from_freelist(gfp_t gfp_mask
, nodemask_t
*nodemask
, unsigned int order
,
1518 struct zonelist
*zonelist
, int high_zoneidx
, int alloc_flags
,
1519 struct zone
*preferred_zone
, int migratetype
)
1522 struct page
*page
= NULL
;
1525 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1526 int zlc_active
= 0; /* set if using zonelist_cache */
1527 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1529 classzone_idx
= zone_idx(preferred_zone
);
1532 * Scan zonelist, looking for a zone with enough free.
1533 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1535 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
1536 high_zoneidx
, nodemask
) {
1537 if (NUMA_BUILD
&& zlc_active
&&
1538 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1540 if ((alloc_flags
& ALLOC_CPUSET
) &&
1541 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1544 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
1545 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
1549 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
1550 if (zone_watermark_ok(zone
, order
, mark
,
1551 classzone_idx
, alloc_flags
))
1554 if (zone_reclaim_mode
== 0)
1555 goto this_zone_full
;
1557 ret
= zone_reclaim(zone
, gfp_mask
, order
);
1559 case ZONE_RECLAIM_NOSCAN
:
1562 case ZONE_RECLAIM_FULL
:
1563 /* scanned but unreclaimable */
1564 goto this_zone_full
;
1566 /* did we reclaim enough */
1567 if (!zone_watermark_ok(zone
, order
, mark
,
1568 classzone_idx
, alloc_flags
))
1569 goto this_zone_full
;
1574 page
= buffered_rmqueue(preferred_zone
, zone
, order
,
1575 gfp_mask
, migratetype
);
1580 zlc_mark_zone_full(zonelist
, z
);
1582 if (NUMA_BUILD
&& !did_zlc_setup
&& nr_online_nodes
> 1) {
1584 * we do zlc_setup after the first zone is tried but only
1585 * if there are multiple nodes make it worthwhile
1587 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1593 if (unlikely(NUMA_BUILD
&& page
== NULL
&& zlc_active
)) {
1594 /* Disable zlc cache for second zonelist scan */
1602 should_alloc_retry(gfp_t gfp_mask
, unsigned int order
,
1603 unsigned long pages_reclaimed
)
1605 /* Do not loop if specifically requested */
1606 if (gfp_mask
& __GFP_NORETRY
)
1610 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
1611 * means __GFP_NOFAIL, but that may not be true in other
1614 if (order
<= PAGE_ALLOC_COSTLY_ORDER
)
1618 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
1619 * specified, then we retry until we no longer reclaim any pages
1620 * (above), or we've reclaimed an order of pages at least as
1621 * large as the allocation's order. In both cases, if the
1622 * allocation still fails, we stop retrying.
1624 if (gfp_mask
& __GFP_REPEAT
&& pages_reclaimed
< (1 << order
))
1628 * Don't let big-order allocations loop unless the caller
1629 * explicitly requests that.
1631 if (gfp_mask
& __GFP_NOFAIL
)
1637 static inline struct page
*
1638 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
1639 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1640 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
1645 /* Acquire the OOM killer lock for the zones in zonelist */
1646 if (!try_set_zone_oom(zonelist
, gfp_mask
)) {
1647 schedule_timeout_uninterruptible(1);
1652 * Go through the zonelist yet one more time, keep very high watermark
1653 * here, this is only to catch a parallel oom killing, we must fail if
1654 * we're still under heavy pressure.
1656 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
,
1657 order
, zonelist
, high_zoneidx
,
1658 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
,
1659 preferred_zone
, migratetype
);
1663 /* The OOM killer will not help higher order allocs */
1664 if (order
> PAGE_ALLOC_COSTLY_ORDER
&& !(gfp_mask
& __GFP_NOFAIL
))
1667 /* Exhausted what can be done so it's blamo time */
1668 out_of_memory(zonelist
, gfp_mask
, order
);
1671 clear_zonelist_oom(zonelist
, gfp_mask
);
1675 /* The really slow allocator path where we enter direct reclaim */
1676 static inline struct page
*
1677 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
1678 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1679 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
1680 int migratetype
, unsigned long *did_some_progress
)
1682 struct page
*page
= NULL
;
1683 struct reclaim_state reclaim_state
;
1684 struct task_struct
*p
= current
;
1688 /* We now go into synchronous reclaim */
1689 cpuset_memory_pressure_bump();
1690 p
->flags
|= PF_MEMALLOC
;
1691 lockdep_set_current_reclaim_state(gfp_mask
);
1692 reclaim_state
.reclaimed_slab
= 0;
1693 p
->reclaim_state
= &reclaim_state
;
1695 *did_some_progress
= try_to_free_pages(zonelist
, order
, gfp_mask
, nodemask
);
1697 p
->reclaim_state
= NULL
;
1698 lockdep_clear_current_reclaim_state();
1699 p
->flags
&= ~PF_MEMALLOC
;
1706 if (likely(*did_some_progress
))
1707 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
1708 zonelist
, high_zoneidx
,
1709 alloc_flags
, preferred_zone
,
1715 * This is called in the allocator slow-path if the allocation request is of
1716 * sufficient urgency to ignore watermarks and take other desperate measures
1718 static inline struct page
*
1719 __alloc_pages_high_priority(gfp_t gfp_mask
, unsigned int order
,
1720 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1721 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
1727 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
1728 zonelist
, high_zoneidx
, ALLOC_NO_WATERMARKS
,
1729 preferred_zone
, migratetype
);
1731 if (!page
&& gfp_mask
& __GFP_NOFAIL
)
1732 congestion_wait(BLK_RW_ASYNC
, HZ
/50);
1733 } while (!page
&& (gfp_mask
& __GFP_NOFAIL
));
1739 void wake_all_kswapd(unsigned int order
, struct zonelist
*zonelist
,
1740 enum zone_type high_zoneidx
)
1745 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
)
1746 wakeup_kswapd(zone
, order
);
1750 gfp_to_alloc_flags(gfp_t gfp_mask
)
1752 struct task_struct
*p
= current
;
1753 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
1754 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
1756 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
1757 BUILD_BUG_ON(__GFP_HIGH
!= ALLOC_HIGH
);
1760 * The caller may dip into page reserves a bit more if the caller
1761 * cannot run direct reclaim, or if the caller has realtime scheduling
1762 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
1763 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1765 alloc_flags
|= (gfp_mask
& __GFP_HIGH
);
1768 alloc_flags
|= ALLOC_HARDER
;
1770 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1771 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1773 alloc_flags
&= ~ALLOC_CPUSET
;
1774 } else if (unlikely(rt_task(p
)) && !in_interrupt())
1775 alloc_flags
|= ALLOC_HARDER
;
1777 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
1778 if (!in_interrupt() &&
1779 ((p
->flags
& PF_MEMALLOC
) ||
1780 unlikely(test_thread_flag(TIF_MEMDIE
))))
1781 alloc_flags
|= ALLOC_NO_WATERMARKS
;
1787 static inline struct page
*
1788 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
1789 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1790 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
1793 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
1794 struct page
*page
= NULL
;
1796 unsigned long pages_reclaimed
= 0;
1797 unsigned long did_some_progress
;
1798 struct task_struct
*p
= current
;
1801 * In the slowpath, we sanity check order to avoid ever trying to
1802 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
1803 * be using allocators in order of preference for an area that is
1806 if (order
>= MAX_ORDER
) {
1807 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
1812 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
1813 * __GFP_NOWARN set) should not cause reclaim since the subsystem
1814 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
1815 * using a larger set of nodes after it has established that the
1816 * allowed per node queues are empty and that nodes are
1819 if (NUMA_BUILD
&& (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
1823 wake_all_kswapd(order
, zonelist
, high_zoneidx
);
1826 * OK, we're below the kswapd watermark and have kicked background
1827 * reclaim. Now things get more complex, so set up alloc_flags according
1828 * to how we want to proceed.
1830 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
1832 /* This is the last chance, in general, before the goto nopage. */
1833 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
, zonelist
,
1834 high_zoneidx
, alloc_flags
& ~ALLOC_NO_WATERMARKS
,
1835 preferred_zone
, migratetype
);
1840 /* Allocate without watermarks if the context allows */
1841 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
1842 page
= __alloc_pages_high_priority(gfp_mask
, order
,
1843 zonelist
, high_zoneidx
, nodemask
,
1844 preferred_zone
, migratetype
);
1849 /* Atomic allocations - we can't balance anything */
1853 /* Avoid recursion of direct reclaim */
1854 if (p
->flags
& PF_MEMALLOC
)
1857 /* Avoid allocations with no watermarks from looping endlessly */
1858 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
1861 /* Try direct reclaim and then allocating */
1862 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
,
1863 zonelist
, high_zoneidx
,
1865 alloc_flags
, preferred_zone
,
1866 migratetype
, &did_some_progress
);
1871 * If we failed to make any progress reclaiming, then we are
1872 * running out of options and have to consider going OOM
1874 if (!did_some_progress
) {
1875 if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
1876 if (oom_killer_disabled
)
1878 page
= __alloc_pages_may_oom(gfp_mask
, order
,
1879 zonelist
, high_zoneidx
,
1880 nodemask
, preferred_zone
,
1886 * The OOM killer does not trigger for high-order
1887 * ~__GFP_NOFAIL allocations so if no progress is being
1888 * made, there are no other options and retrying is
1891 if (order
> PAGE_ALLOC_COSTLY_ORDER
&&
1892 !(gfp_mask
& __GFP_NOFAIL
))
1899 /* Check if we should retry the allocation */
1900 pages_reclaimed
+= did_some_progress
;
1901 if (should_alloc_retry(gfp_mask
, order
, pages_reclaimed
)) {
1902 /* Wait for some write requests to complete then retry */
1903 congestion_wait(BLK_RW_ASYNC
, HZ
/50);
1908 if (!(gfp_mask
& __GFP_NOWARN
) && printk_ratelimit()) {
1909 printk(KERN_WARNING
"%s: page allocation failure."
1910 " order:%d, mode:0x%x\n",
1911 p
->comm
, order
, gfp_mask
);
1917 if (kmemcheck_enabled
)
1918 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
1924 * This is the 'heart' of the zoned buddy allocator.
1927 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
1928 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
1930 enum zone_type high_zoneidx
= gfp_zone(gfp_mask
);
1931 struct zone
*preferred_zone
;
1933 int migratetype
= allocflags_to_migratetype(gfp_mask
);
1935 gfp_mask
&= gfp_allowed_mask
;
1937 lockdep_trace_alloc(gfp_mask
);
1939 might_sleep_if(gfp_mask
& __GFP_WAIT
);
1941 if (should_fail_alloc_page(gfp_mask
, order
))
1945 * Check the zones suitable for the gfp_mask contain at least one
1946 * valid zone. It's possible to have an empty zonelist as a result
1947 * of GFP_THISNODE and a memoryless node
1949 if (unlikely(!zonelist
->_zonerefs
->zone
))
1952 /* The preferred zone is used for statistics later */
1953 first_zones_zonelist(zonelist
, high_zoneidx
, nodemask
, &preferred_zone
);
1954 if (!preferred_zone
)
1957 /* First allocation attempt */
1958 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
, order
,
1959 zonelist
, high_zoneidx
, ALLOC_WMARK_LOW
|ALLOC_CPUSET
,
1960 preferred_zone
, migratetype
);
1961 if (unlikely(!page
))
1962 page
= __alloc_pages_slowpath(gfp_mask
, order
,
1963 zonelist
, high_zoneidx
, nodemask
,
1964 preferred_zone
, migratetype
);
1966 trace_mm_page_alloc(page
, order
, gfp_mask
, migratetype
);
1969 EXPORT_SYMBOL(__alloc_pages_nodemask
);
1972 * Common helper functions.
1974 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
1979 * __get_free_pages() returns a 32-bit address, which cannot represent
1982 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
1984 page
= alloc_pages(gfp_mask
, order
);
1987 return (unsigned long) page_address(page
);
1989 EXPORT_SYMBOL(__get_free_pages
);
1991 unsigned long get_zeroed_page(gfp_t gfp_mask
)
1993 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
1995 EXPORT_SYMBOL(get_zeroed_page
);
1997 void __pagevec_free(struct pagevec
*pvec
)
1999 int i
= pagevec_count(pvec
);
2002 trace_mm_pagevec_free(pvec
->pages
[i
], pvec
->cold
);
2003 free_hot_cold_page(pvec
->pages
[i
], pvec
->cold
);
2007 void __free_pages(struct page
*page
, unsigned int order
)
2009 if (put_page_testzero(page
)) {
2010 trace_mm_page_free_direct(page
, order
);
2012 free_hot_page(page
);
2014 __free_pages_ok(page
, order
);
2018 EXPORT_SYMBOL(__free_pages
);
2020 void free_pages(unsigned long addr
, unsigned int order
)
2023 VM_BUG_ON(!virt_addr_valid((void *)addr
));
2024 __free_pages(virt_to_page((void *)addr
), order
);
2028 EXPORT_SYMBOL(free_pages
);
2031 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2032 * @size: the number of bytes to allocate
2033 * @gfp_mask: GFP flags for the allocation
2035 * This function is similar to alloc_pages(), except that it allocates the
2036 * minimum number of pages to satisfy the request. alloc_pages() can only
2037 * allocate memory in power-of-two pages.
2039 * This function is also limited by MAX_ORDER.
2041 * Memory allocated by this function must be released by free_pages_exact().
2043 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
2045 unsigned int order
= get_order(size
);
2048 addr
= __get_free_pages(gfp_mask
, order
);
2050 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
2051 unsigned long used
= addr
+ PAGE_ALIGN(size
);
2053 split_page(virt_to_page((void *)addr
), order
);
2054 while (used
< alloc_end
) {
2060 return (void *)addr
;
2062 EXPORT_SYMBOL(alloc_pages_exact
);
2065 * free_pages_exact - release memory allocated via alloc_pages_exact()
2066 * @virt: the value returned by alloc_pages_exact.
2067 * @size: size of allocation, same value as passed to alloc_pages_exact().
2069 * Release the memory allocated by a previous call to alloc_pages_exact.
2071 void free_pages_exact(void *virt
, size_t size
)
2073 unsigned long addr
= (unsigned long)virt
;
2074 unsigned long end
= addr
+ PAGE_ALIGN(size
);
2076 while (addr
< end
) {
2081 EXPORT_SYMBOL(free_pages_exact
);
2083 static unsigned int nr_free_zone_pages(int offset
)
2088 /* Just pick one node, since fallback list is circular */
2089 unsigned int sum
= 0;
2091 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
2093 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
2094 unsigned long size
= zone
->present_pages
;
2095 unsigned long high
= high_wmark_pages(zone
);
2104 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
2106 unsigned int nr_free_buffer_pages(void)
2108 return nr_free_zone_pages(gfp_zone(GFP_USER
));
2110 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
2113 * Amount of free RAM allocatable within all zones
2115 unsigned int nr_free_pagecache_pages(void)
2117 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
2120 static inline void show_node(struct zone
*zone
)
2123 printk("Node %d ", zone_to_nid(zone
));
2126 void si_meminfo(struct sysinfo
*val
)
2128 val
->totalram
= totalram_pages
;
2130 val
->freeram
= global_page_state(NR_FREE_PAGES
);
2131 val
->bufferram
= nr_blockdev_pages();
2132 val
->totalhigh
= totalhigh_pages
;
2133 val
->freehigh
= nr_free_highpages();
2134 val
->mem_unit
= PAGE_SIZE
;
2137 EXPORT_SYMBOL(si_meminfo
);
2140 void si_meminfo_node(struct sysinfo
*val
, int nid
)
2142 pg_data_t
*pgdat
= NODE_DATA(nid
);
2144 val
->totalram
= pgdat
->node_present_pages
;
2145 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
2146 #ifdef CONFIG_HIGHMEM
2147 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
2148 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
2154 val
->mem_unit
= PAGE_SIZE
;
2158 #define K(x) ((x) << (PAGE_SHIFT-10))
2161 * Show free area list (used inside shift_scroll-lock stuff)
2162 * We also calculate the percentage fragmentation. We do this by counting the
2163 * memory on each free list with the exception of the first item on the list.
2165 void show_free_areas(void)
2170 for_each_populated_zone(zone
) {
2172 printk("%s per-cpu:\n", zone
->name
);
2174 for_each_online_cpu(cpu
) {
2175 struct per_cpu_pageset
*pageset
;
2177 pageset
= zone_pcp(zone
, cpu
);
2179 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
2180 cpu
, pageset
->pcp
.high
,
2181 pageset
->pcp
.batch
, pageset
->pcp
.count
);
2185 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
2186 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
2188 " dirty:%lu writeback:%lu unstable:%lu\n"
2189 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2190 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
2191 global_page_state(NR_ACTIVE_ANON
),
2192 global_page_state(NR_INACTIVE_ANON
),
2193 global_page_state(NR_ISOLATED_ANON
),
2194 global_page_state(NR_ACTIVE_FILE
),
2195 global_page_state(NR_INACTIVE_FILE
),
2196 global_page_state(NR_ISOLATED_FILE
),
2197 global_page_state(NR_UNEVICTABLE
),
2198 global_page_state(NR_FILE_DIRTY
),
2199 global_page_state(NR_WRITEBACK
),
2200 global_page_state(NR_UNSTABLE_NFS
),
2201 global_page_state(NR_FREE_PAGES
),
2202 global_page_state(NR_SLAB_RECLAIMABLE
),
2203 global_page_state(NR_SLAB_UNRECLAIMABLE
),
2204 global_page_state(NR_FILE_MAPPED
),
2205 global_page_state(NR_SHMEM
),
2206 global_page_state(NR_PAGETABLE
),
2207 global_page_state(NR_BOUNCE
));
2209 for_each_populated_zone(zone
) {
2218 " active_anon:%lukB"
2219 " inactive_anon:%lukB"
2220 " active_file:%lukB"
2221 " inactive_file:%lukB"
2222 " unevictable:%lukB"
2223 " isolated(anon):%lukB"
2224 " isolated(file):%lukB"
2231 " slab_reclaimable:%lukB"
2232 " slab_unreclaimable:%lukB"
2233 " kernel_stack:%lukB"
2237 " writeback_tmp:%lukB"
2238 " pages_scanned:%lu"
2239 " all_unreclaimable? %s"
2242 K(zone_page_state(zone
, NR_FREE_PAGES
)),
2243 K(min_wmark_pages(zone
)),
2244 K(low_wmark_pages(zone
)),
2245 K(high_wmark_pages(zone
)),
2246 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
2247 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
2248 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
2249 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
2250 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
2251 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
2252 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
2253 K(zone
->present_pages
),
2254 K(zone_page_state(zone
, NR_MLOCK
)),
2255 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
2256 K(zone_page_state(zone
, NR_WRITEBACK
)),
2257 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
2258 K(zone_page_state(zone
, NR_SHMEM
)),
2259 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
2260 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
2261 zone_page_state(zone
, NR_KERNEL_STACK
) *
2263 K(zone_page_state(zone
, NR_PAGETABLE
)),
2264 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
2265 K(zone_page_state(zone
, NR_BOUNCE
)),
2266 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
2267 zone
->pages_scanned
,
2268 (zone_is_all_unreclaimable(zone
) ? "yes" : "no")
2270 printk("lowmem_reserve[]:");
2271 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
2272 printk(" %lu", zone
->lowmem_reserve
[i
]);
2276 for_each_populated_zone(zone
) {
2277 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
2280 printk("%s: ", zone
->name
);
2282 spin_lock_irqsave(&zone
->lock
, flags
);
2283 for (order
= 0; order
< MAX_ORDER
; order
++) {
2284 nr
[order
] = zone
->free_area
[order
].nr_free
;
2285 total
+= nr
[order
] << order
;
2287 spin_unlock_irqrestore(&zone
->lock
, flags
);
2288 for (order
= 0; order
< MAX_ORDER
; order
++)
2289 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
2290 printk("= %lukB\n", K(total
));
2293 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
2295 show_swap_cache_info();
2298 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
2300 zoneref
->zone
= zone
;
2301 zoneref
->zone_idx
= zone_idx(zone
);
2305 * Builds allocation fallback zone lists.
2307 * Add all populated zones of a node to the zonelist.
2309 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
2310 int nr_zones
, enum zone_type zone_type
)
2314 BUG_ON(zone_type
>= MAX_NR_ZONES
);
2319 zone
= pgdat
->node_zones
+ zone_type
;
2320 if (populated_zone(zone
)) {
2321 zoneref_set_zone(zone
,
2322 &zonelist
->_zonerefs
[nr_zones
++]);
2323 check_highest_zone(zone_type
);
2326 } while (zone_type
);
2333 * 0 = automatic detection of better ordering.
2334 * 1 = order by ([node] distance, -zonetype)
2335 * 2 = order by (-zonetype, [node] distance)
2337 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
2338 * the same zonelist. So only NUMA can configure this param.
2340 #define ZONELIST_ORDER_DEFAULT 0
2341 #define ZONELIST_ORDER_NODE 1
2342 #define ZONELIST_ORDER_ZONE 2
2344 /* zonelist order in the kernel.
2345 * set_zonelist_order() will set this to NODE or ZONE.
2347 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2348 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
2352 /* The value user specified ....changed by config */
2353 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2354 /* string for sysctl */
2355 #define NUMA_ZONELIST_ORDER_LEN 16
2356 char numa_zonelist_order
[16] = "default";
2359 * interface for configure zonelist ordering.
2360 * command line option "numa_zonelist_order"
2361 * = "[dD]efault - default, automatic configuration.
2362 * = "[nN]ode - order by node locality, then by zone within node
2363 * = "[zZ]one - order by zone, then by locality within zone
2366 static int __parse_numa_zonelist_order(char *s
)
2368 if (*s
== 'd' || *s
== 'D') {
2369 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2370 } else if (*s
== 'n' || *s
== 'N') {
2371 user_zonelist_order
= ZONELIST_ORDER_NODE
;
2372 } else if (*s
== 'z' || *s
== 'Z') {
2373 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
2376 "Ignoring invalid numa_zonelist_order value: "
2383 static __init
int setup_numa_zonelist_order(char *s
)
2386 return __parse_numa_zonelist_order(s
);
2389 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
2392 * sysctl handler for numa_zonelist_order
2394 int numa_zonelist_order_handler(ctl_table
*table
, int write
,
2395 void __user
*buffer
, size_t *length
,
2398 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
2402 strncpy(saved_string
, (char*)table
->data
,
2403 NUMA_ZONELIST_ORDER_LEN
);
2404 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
2408 int oldval
= user_zonelist_order
;
2409 if (__parse_numa_zonelist_order((char*)table
->data
)) {
2411 * bogus value. restore saved string
2413 strncpy((char*)table
->data
, saved_string
,
2414 NUMA_ZONELIST_ORDER_LEN
);
2415 user_zonelist_order
= oldval
;
2416 } else if (oldval
!= user_zonelist_order
)
2417 build_all_zonelists();
2423 #define MAX_NODE_LOAD (nr_online_nodes)
2424 static int node_load
[MAX_NUMNODES
];
2427 * find_next_best_node - find the next node that should appear in a given node's fallback list
2428 * @node: node whose fallback list we're appending
2429 * @used_node_mask: nodemask_t of already used nodes
2431 * We use a number of factors to determine which is the next node that should
2432 * appear on a given node's fallback list. The node should not have appeared
2433 * already in @node's fallback list, and it should be the next closest node
2434 * according to the distance array (which contains arbitrary distance values
2435 * from each node to each node in the system), and should also prefer nodes
2436 * with no CPUs, since presumably they'll have very little allocation pressure
2437 * on them otherwise.
2438 * It returns -1 if no node is found.
2440 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
2443 int min_val
= INT_MAX
;
2445 const struct cpumask
*tmp
= cpumask_of_node(0);
2447 /* Use the local node if we haven't already */
2448 if (!node_isset(node
, *used_node_mask
)) {
2449 node_set(node
, *used_node_mask
);
2453 for_each_node_state(n
, N_HIGH_MEMORY
) {
2455 /* Don't want a node to appear more than once */
2456 if (node_isset(n
, *used_node_mask
))
2459 /* Use the distance array to find the distance */
2460 val
= node_distance(node
, n
);
2462 /* Penalize nodes under us ("prefer the next node") */
2465 /* Give preference to headless and unused nodes */
2466 tmp
= cpumask_of_node(n
);
2467 if (!cpumask_empty(tmp
))
2468 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
2470 /* Slight preference for less loaded node */
2471 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
2472 val
+= node_load
[n
];
2474 if (val
< min_val
) {
2481 node_set(best_node
, *used_node_mask
);
2488 * Build zonelists ordered by node and zones within node.
2489 * This results in maximum locality--normal zone overflows into local
2490 * DMA zone, if any--but risks exhausting DMA zone.
2492 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
2495 struct zonelist
*zonelist
;
2497 zonelist
= &pgdat
->node_zonelists
[0];
2498 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
2500 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2502 zonelist
->_zonerefs
[j
].zone
= NULL
;
2503 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2507 * Build gfp_thisnode zonelists
2509 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
2512 struct zonelist
*zonelist
;
2514 zonelist
= &pgdat
->node_zonelists
[1];
2515 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
2516 zonelist
->_zonerefs
[j
].zone
= NULL
;
2517 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2521 * Build zonelists ordered by zone and nodes within zones.
2522 * This results in conserving DMA zone[s] until all Normal memory is
2523 * exhausted, but results in overflowing to remote node while memory
2524 * may still exist in local DMA zone.
2526 static int node_order
[MAX_NUMNODES
];
2528 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
2531 int zone_type
; /* needs to be signed */
2533 struct zonelist
*zonelist
;
2535 zonelist
= &pgdat
->node_zonelists
[0];
2537 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
2538 for (j
= 0; j
< nr_nodes
; j
++) {
2539 node
= node_order
[j
];
2540 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
2541 if (populated_zone(z
)) {
2543 &zonelist
->_zonerefs
[pos
++]);
2544 check_highest_zone(zone_type
);
2548 zonelist
->_zonerefs
[pos
].zone
= NULL
;
2549 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
2552 static int default_zonelist_order(void)
2555 unsigned long low_kmem_size
,total_size
;
2559 * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem.
2560 * If they are really small and used heavily, the system can fall
2561 * into OOM very easily.
2562 * This function detect ZONE_DMA/DMA32 size and confgigures zone order.
2564 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
2567 for_each_online_node(nid
) {
2568 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2569 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2570 if (populated_zone(z
)) {
2571 if (zone_type
< ZONE_NORMAL
)
2572 low_kmem_size
+= z
->present_pages
;
2573 total_size
+= z
->present_pages
;
2577 if (!low_kmem_size
|| /* there are no DMA area. */
2578 low_kmem_size
> total_size
/2) /* DMA/DMA32 is big. */
2579 return ZONELIST_ORDER_NODE
;
2581 * look into each node's config.
2582 * If there is a node whose DMA/DMA32 memory is very big area on
2583 * local memory, NODE_ORDER may be suitable.
2585 average_size
= total_size
/
2586 (nodes_weight(node_states
[N_HIGH_MEMORY
]) + 1);
2587 for_each_online_node(nid
) {
2590 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2591 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2592 if (populated_zone(z
)) {
2593 if (zone_type
< ZONE_NORMAL
)
2594 low_kmem_size
+= z
->present_pages
;
2595 total_size
+= z
->present_pages
;
2598 if (low_kmem_size
&&
2599 total_size
> average_size
&& /* ignore small node */
2600 low_kmem_size
> total_size
* 70/100)
2601 return ZONELIST_ORDER_NODE
;
2603 return ZONELIST_ORDER_ZONE
;
2606 static void set_zonelist_order(void)
2608 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
2609 current_zonelist_order
= default_zonelist_order();
2611 current_zonelist_order
= user_zonelist_order
;
2614 static void build_zonelists(pg_data_t
*pgdat
)
2618 nodemask_t used_mask
;
2619 int local_node
, prev_node
;
2620 struct zonelist
*zonelist
;
2621 int order
= current_zonelist_order
;
2623 /* initialize zonelists */
2624 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
2625 zonelist
= pgdat
->node_zonelists
+ i
;
2626 zonelist
->_zonerefs
[0].zone
= NULL
;
2627 zonelist
->_zonerefs
[0].zone_idx
= 0;
2630 /* NUMA-aware ordering of nodes */
2631 local_node
= pgdat
->node_id
;
2632 load
= nr_online_nodes
;
2633 prev_node
= local_node
;
2634 nodes_clear(used_mask
);
2636 memset(node_order
, 0, sizeof(node_order
));
2639 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
2640 int distance
= node_distance(local_node
, node
);
2643 * If another node is sufficiently far away then it is better
2644 * to reclaim pages in a zone before going off node.
2646 if (distance
> RECLAIM_DISTANCE
)
2647 zone_reclaim_mode
= 1;
2650 * We don't want to pressure a particular node.
2651 * So adding penalty to the first node in same
2652 * distance group to make it round-robin.
2654 if (distance
!= node_distance(local_node
, prev_node
))
2655 node_load
[node
] = load
;
2659 if (order
== ZONELIST_ORDER_NODE
)
2660 build_zonelists_in_node_order(pgdat
, node
);
2662 node_order
[j
++] = node
; /* remember order */
2665 if (order
== ZONELIST_ORDER_ZONE
) {
2666 /* calculate node order -- i.e., DMA last! */
2667 build_zonelists_in_zone_order(pgdat
, j
);
2670 build_thisnode_zonelists(pgdat
);
2673 /* Construct the zonelist performance cache - see further mmzone.h */
2674 static void build_zonelist_cache(pg_data_t
*pgdat
)
2676 struct zonelist
*zonelist
;
2677 struct zonelist_cache
*zlc
;
2680 zonelist
= &pgdat
->node_zonelists
[0];
2681 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
2682 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
2683 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
2684 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
2688 #else /* CONFIG_NUMA */
2690 static void set_zonelist_order(void)
2692 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
2695 static void build_zonelists(pg_data_t
*pgdat
)
2697 int node
, local_node
;
2699 struct zonelist
*zonelist
;
2701 local_node
= pgdat
->node_id
;
2703 zonelist
= &pgdat
->node_zonelists
[0];
2704 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
2707 * Now we build the zonelist so that it contains the zones
2708 * of all the other nodes.
2709 * We don't want to pressure a particular node, so when
2710 * building the zones for node N, we make sure that the
2711 * zones coming right after the local ones are those from
2712 * node N+1 (modulo N)
2714 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
2715 if (!node_online(node
))
2717 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2720 for (node
= 0; node
< local_node
; node
++) {
2721 if (!node_online(node
))
2723 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2727 zonelist
->_zonerefs
[j
].zone
= NULL
;
2728 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2731 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2732 static void build_zonelist_cache(pg_data_t
*pgdat
)
2734 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
2737 #endif /* CONFIG_NUMA */
2739 /* return values int ....just for stop_machine() */
2740 static int __build_all_zonelists(void *dummy
)
2745 memset(node_load
, 0, sizeof(node_load
));
2747 for_each_online_node(nid
) {
2748 pg_data_t
*pgdat
= NODE_DATA(nid
);
2750 build_zonelists(pgdat
);
2751 build_zonelist_cache(pgdat
);
2756 void build_all_zonelists(void)
2758 set_zonelist_order();
2760 if (system_state
== SYSTEM_BOOTING
) {
2761 __build_all_zonelists(NULL
);
2762 mminit_verify_zonelist();
2763 cpuset_init_current_mems_allowed();
2765 /* we have to stop all cpus to guarantee there is no user
2767 stop_machine(__build_all_zonelists
, NULL
, NULL
);
2768 /* cpuset refresh routine should be here */
2770 vm_total_pages
= nr_free_pagecache_pages();
2772 * Disable grouping by mobility if the number of pages in the
2773 * system is too low to allow the mechanism to work. It would be
2774 * more accurate, but expensive to check per-zone. This check is
2775 * made on memory-hotadd so a system can start with mobility
2776 * disabled and enable it later
2778 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
2779 page_group_by_mobility_disabled
= 1;
2781 page_group_by_mobility_disabled
= 0;
2783 printk("Built %i zonelists in %s order, mobility grouping %s. "
2784 "Total pages: %ld\n",
2786 zonelist_order_name
[current_zonelist_order
],
2787 page_group_by_mobility_disabled
? "off" : "on",
2790 printk("Policy zone: %s\n", zone_names
[policy_zone
]);
2795 * Helper functions to size the waitqueue hash table.
2796 * Essentially these want to choose hash table sizes sufficiently
2797 * large so that collisions trying to wait on pages are rare.
2798 * But in fact, the number of active page waitqueues on typical
2799 * systems is ridiculously low, less than 200. So this is even
2800 * conservative, even though it seems large.
2802 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
2803 * waitqueues, i.e. the size of the waitq table given the number of pages.
2805 #define PAGES_PER_WAITQUEUE 256
2807 #ifndef CONFIG_MEMORY_HOTPLUG
2808 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
2810 unsigned long size
= 1;
2812 pages
/= PAGES_PER_WAITQUEUE
;
2814 while (size
< pages
)
2818 * Once we have dozens or even hundreds of threads sleeping
2819 * on IO we've got bigger problems than wait queue collision.
2820 * Limit the size of the wait table to a reasonable size.
2822 size
= min(size
, 4096UL);
2824 return max(size
, 4UL);
2828 * A zone's size might be changed by hot-add, so it is not possible to determine
2829 * a suitable size for its wait_table. So we use the maximum size now.
2831 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
2833 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
2834 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
2835 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
2837 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
2838 * or more by the traditional way. (See above). It equals:
2840 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
2841 * ia64(16K page size) : = ( 8G + 4M)byte.
2842 * powerpc (64K page size) : = (32G +16M)byte.
2844 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
2851 * This is an integer logarithm so that shifts can be used later
2852 * to extract the more random high bits from the multiplicative
2853 * hash function before the remainder is taken.
2855 static inline unsigned long wait_table_bits(unsigned long size
)
2860 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
2863 * Check if a pageblock contains reserved pages
2865 static int pageblock_is_reserved(unsigned long start_pfn
)
2867 unsigned long end_pfn
= start_pfn
+ pageblock_nr_pages
;
2870 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
2871 if (PageReserved(pfn_to_page(pfn
)))
2877 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2878 * of blocks reserved is based on min_wmark_pages(zone). The memory within
2879 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
2880 * higher will lead to a bigger reserve which will get freed as contiguous
2881 * blocks as reclaim kicks in
2883 static void setup_zone_migrate_reserve(struct zone
*zone
)
2885 unsigned long start_pfn
, pfn
, end_pfn
;
2887 unsigned long block_migratetype
;
2890 /* Get the start pfn, end pfn and the number of blocks to reserve */
2891 start_pfn
= zone
->zone_start_pfn
;
2892 end_pfn
= start_pfn
+ zone
->spanned_pages
;
2893 reserve
= roundup(min_wmark_pages(zone
), pageblock_nr_pages
) >>
2897 * Reserve blocks are generally in place to help high-order atomic
2898 * allocations that are short-lived. A min_free_kbytes value that
2899 * would result in more than 2 reserve blocks for atomic allocations
2900 * is assumed to be in place to help anti-fragmentation for the
2901 * future allocation of hugepages at runtime.
2903 reserve
= min(2, reserve
);
2905 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
2906 if (!pfn_valid(pfn
))
2908 page
= pfn_to_page(pfn
);
2910 /* Watch out for overlapping nodes */
2911 if (page_to_nid(page
) != zone_to_nid(zone
))
2914 /* Blocks with reserved pages will never free, skip them. */
2915 if (pageblock_is_reserved(pfn
))
2918 block_migratetype
= get_pageblock_migratetype(page
);
2920 /* If this block is reserved, account for it */
2921 if (reserve
> 0 && block_migratetype
== MIGRATE_RESERVE
) {
2926 /* Suitable for reserving if this block is movable */
2927 if (reserve
> 0 && block_migratetype
== MIGRATE_MOVABLE
) {
2928 set_pageblock_migratetype(page
, MIGRATE_RESERVE
);
2929 move_freepages_block(zone
, page
, MIGRATE_RESERVE
);
2935 * If the reserve is met and this is a previous reserved block,
2938 if (block_migratetype
== MIGRATE_RESERVE
) {
2939 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
2940 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
2946 * Initially all pages are reserved - free ones are freed
2947 * up by free_all_bootmem() once the early boot process is
2948 * done. Non-atomic initialization, single-pass.
2950 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
2951 unsigned long start_pfn
, enum memmap_context context
)
2954 unsigned long end_pfn
= start_pfn
+ size
;
2958 if (highest_memmap_pfn
< end_pfn
- 1)
2959 highest_memmap_pfn
= end_pfn
- 1;
2961 z
= &NODE_DATA(nid
)->node_zones
[zone
];
2962 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
2964 * There can be holes in boot-time mem_map[]s
2965 * handed to this function. They do not
2966 * exist on hotplugged memory.
2968 if (context
== MEMMAP_EARLY
) {
2969 if (!early_pfn_valid(pfn
))
2971 if (!early_pfn_in_nid(pfn
, nid
))
2974 page
= pfn_to_page(pfn
);
2975 set_page_links(page
, zone
, nid
, pfn
);
2976 mminit_verify_page_links(page
, zone
, nid
, pfn
);
2977 init_page_count(page
);
2978 reset_page_mapcount(page
);
2979 SetPageReserved(page
);
2981 * Mark the block movable so that blocks are reserved for
2982 * movable at startup. This will force kernel allocations
2983 * to reserve their blocks rather than leaking throughout
2984 * the address space during boot when many long-lived
2985 * kernel allocations are made. Later some blocks near
2986 * the start are marked MIGRATE_RESERVE by
2987 * setup_zone_migrate_reserve()
2989 * bitmap is created for zone's valid pfn range. but memmap
2990 * can be created for invalid pages (for alignment)
2991 * check here not to call set_pageblock_migratetype() against
2994 if ((z
->zone_start_pfn
<= pfn
)
2995 && (pfn
< z
->zone_start_pfn
+ z
->spanned_pages
)
2996 && !(pfn
& (pageblock_nr_pages
- 1)))
2997 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
2999 INIT_LIST_HEAD(&page
->lru
);
3000 #ifdef WANT_PAGE_VIRTUAL
3001 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
3002 if (!is_highmem_idx(zone
))
3003 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
3008 static void __meminit
zone_init_free_lists(struct zone
*zone
)
3011 for_each_migratetype_order(order
, t
) {
3012 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
3013 zone
->free_area
[order
].nr_free
= 0;
3017 #ifndef __HAVE_ARCH_MEMMAP_INIT
3018 #define memmap_init(size, nid, zone, start_pfn) \
3019 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
3022 static int zone_batchsize(struct zone
*zone
)
3028 * The per-cpu-pages pools are set to around 1000th of the
3029 * size of the zone. But no more than 1/2 of a meg.
3031 * OK, so we don't know how big the cache is. So guess.
3033 batch
= zone
->present_pages
/ 1024;
3034 if (batch
* PAGE_SIZE
> 512 * 1024)
3035 batch
= (512 * 1024) / PAGE_SIZE
;
3036 batch
/= 4; /* We effectively *= 4 below */
3041 * Clamp the batch to a 2^n - 1 value. Having a power
3042 * of 2 value was found to be more likely to have
3043 * suboptimal cache aliasing properties in some cases.
3045 * For example if 2 tasks are alternately allocating
3046 * batches of pages, one task can end up with a lot
3047 * of pages of one half of the possible page colors
3048 * and the other with pages of the other colors.
3050 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
3055 /* The deferral and batching of frees should be suppressed under NOMMU
3058 * The problem is that NOMMU needs to be able to allocate large chunks
3059 * of contiguous memory as there's no hardware page translation to
3060 * assemble apparent contiguous memory from discontiguous pages.
3062 * Queueing large contiguous runs of pages for batching, however,
3063 * causes the pages to actually be freed in smaller chunks. As there
3064 * can be a significant delay between the individual batches being
3065 * recycled, this leads to the once large chunks of space being
3066 * fragmented and becoming unavailable for high-order allocations.
3072 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
3074 struct per_cpu_pages
*pcp
;
3077 memset(p
, 0, sizeof(*p
));
3081 pcp
->high
= 6 * batch
;
3082 pcp
->batch
= max(1UL, 1 * batch
);
3083 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
3084 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
3088 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
3089 * to the value high for the pageset p.
3092 static void setup_pagelist_highmark(struct per_cpu_pageset
*p
,
3095 struct per_cpu_pages
*pcp
;
3099 pcp
->batch
= max(1UL, high
/4);
3100 if ((high
/4) > (PAGE_SHIFT
* 8))
3101 pcp
->batch
= PAGE_SHIFT
* 8;
3107 * Boot pageset table. One per cpu which is going to be used for all
3108 * zones and all nodes. The parameters will be set in such a way
3109 * that an item put on a list will immediately be handed over to
3110 * the buddy list. This is safe since pageset manipulation is done
3111 * with interrupts disabled.
3113 * Some NUMA counter updates may also be caught by the boot pagesets.
3115 * The boot_pagesets must be kept even after bootup is complete for
3116 * unused processors and/or zones. They do play a role for bootstrapping
3117 * hotplugged processors.
3119 * zoneinfo_show() and maybe other functions do
3120 * not check if the processor is online before following the pageset pointer.
3121 * Other parts of the kernel may not check if the zone is available.
3123 static struct per_cpu_pageset boot_pageset
[NR_CPUS
];
3126 * Dynamically allocate memory for the
3127 * per cpu pageset array in struct zone.
3129 static int __cpuinit
process_zones(int cpu
)
3131 struct zone
*zone
, *dzone
;
3132 int node
= cpu_to_node(cpu
);
3134 node_set_state(node
, N_CPU
); /* this node has a cpu */
3136 for_each_populated_zone(zone
) {
3137 zone_pcp(zone
, cpu
) = kmalloc_node(sizeof(struct per_cpu_pageset
),
3139 if (!zone_pcp(zone
, cpu
))
3142 setup_pageset(zone_pcp(zone
, cpu
), zone_batchsize(zone
));
3144 if (percpu_pagelist_fraction
)
3145 setup_pagelist_highmark(zone_pcp(zone
, cpu
),
3146 (zone
->present_pages
/ percpu_pagelist_fraction
));
3151 for_each_zone(dzone
) {
3152 if (!populated_zone(dzone
))
3156 kfree(zone_pcp(dzone
, cpu
));
3157 zone_pcp(dzone
, cpu
) = &boot_pageset
[cpu
];
3162 static inline void free_zone_pagesets(int cpu
)
3166 for_each_zone(zone
) {
3167 struct per_cpu_pageset
*pset
= zone_pcp(zone
, cpu
);
3169 /* Free per_cpu_pageset if it is slab allocated */
3170 if (pset
!= &boot_pageset
[cpu
])
3172 zone_pcp(zone
, cpu
) = &boot_pageset
[cpu
];
3176 static int __cpuinit
pageset_cpuup_callback(struct notifier_block
*nfb
,
3177 unsigned long action
,
3180 int cpu
= (long)hcpu
;
3181 int ret
= NOTIFY_OK
;
3184 case CPU_UP_PREPARE
:
3185 case CPU_UP_PREPARE_FROZEN
:
3186 if (process_zones(cpu
))
3189 case CPU_UP_CANCELED
:
3190 case CPU_UP_CANCELED_FROZEN
:
3192 case CPU_DEAD_FROZEN
:
3193 free_zone_pagesets(cpu
);
3201 static struct notifier_block __cpuinitdata pageset_notifier
=
3202 { &pageset_cpuup_callback
, NULL
, 0 };
3204 void __init
setup_per_cpu_pageset(void)
3208 /* Initialize per_cpu_pageset for cpu 0.
3209 * A cpuup callback will do this for every cpu
3210 * as it comes online
3212 err
= process_zones(smp_processor_id());
3214 register_cpu_notifier(&pageset_notifier
);
3219 static noinline __init_refok
3220 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
3223 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
3227 * The per-page waitqueue mechanism uses hashed waitqueues
3230 zone
->wait_table_hash_nr_entries
=
3231 wait_table_hash_nr_entries(zone_size_pages
);
3232 zone
->wait_table_bits
=
3233 wait_table_bits(zone
->wait_table_hash_nr_entries
);
3234 alloc_size
= zone
->wait_table_hash_nr_entries
3235 * sizeof(wait_queue_head_t
);
3237 if (!slab_is_available()) {
3238 zone
->wait_table
= (wait_queue_head_t
*)
3239 alloc_bootmem_node(pgdat
, alloc_size
);
3242 * This case means that a zone whose size was 0 gets new memory
3243 * via memory hot-add.
3244 * But it may be the case that a new node was hot-added. In
3245 * this case vmalloc() will not be able to use this new node's
3246 * memory - this wait_table must be initialized to use this new
3247 * node itself as well.
3248 * To use this new node's memory, further consideration will be
3251 zone
->wait_table
= vmalloc(alloc_size
);
3253 if (!zone
->wait_table
)
3256 for(i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
3257 init_waitqueue_head(zone
->wait_table
+ i
);
3262 static int __zone_pcp_update(void *data
)
3264 struct zone
*zone
= data
;
3266 unsigned long batch
= zone_batchsize(zone
), flags
;
3268 for (cpu
= 0; cpu
< NR_CPUS
; cpu
++) {
3269 struct per_cpu_pageset
*pset
;
3270 struct per_cpu_pages
*pcp
;
3272 pset
= zone_pcp(zone
, cpu
);
3275 local_irq_save(flags
);
3276 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
3277 setup_pageset(pset
, batch
);
3278 local_irq_restore(flags
);
3283 void zone_pcp_update(struct zone
*zone
)
3285 stop_machine(__zone_pcp_update
, zone
, NULL
);
3288 static __meminit
void zone_pcp_init(struct zone
*zone
)
3291 unsigned long batch
= zone_batchsize(zone
);
3293 for (cpu
= 0; cpu
< NR_CPUS
; cpu
++) {
3295 /* Early boot. Slab allocator not functional yet */
3296 zone_pcp(zone
, cpu
) = &boot_pageset
[cpu
];
3297 setup_pageset(&boot_pageset
[cpu
],0);
3299 setup_pageset(zone_pcp(zone
,cpu
), batch
);
3302 if (zone
->present_pages
)
3303 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%lu\n",
3304 zone
->name
, zone
->present_pages
, batch
);
3307 __meminit
int init_currently_empty_zone(struct zone
*zone
,
3308 unsigned long zone_start_pfn
,
3310 enum memmap_context context
)
3312 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
3314 ret
= zone_wait_table_init(zone
, size
);
3317 pgdat
->nr_zones
= zone_idx(zone
) + 1;
3319 zone
->zone_start_pfn
= zone_start_pfn
;
3321 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
3322 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
3324 (unsigned long)zone_idx(zone
),
3325 zone_start_pfn
, (zone_start_pfn
+ size
));
3327 zone_init_free_lists(zone
);
3332 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3334 * Basic iterator support. Return the first range of PFNs for a node
3335 * Note: nid == MAX_NUMNODES returns first region regardless of node
3337 static int __meminit
first_active_region_index_in_nid(int nid
)
3341 for (i
= 0; i
< nr_nodemap_entries
; i
++)
3342 if (nid
== MAX_NUMNODES
|| early_node_map
[i
].nid
== nid
)
3349 * Basic iterator support. Return the next active range of PFNs for a node
3350 * Note: nid == MAX_NUMNODES returns next region regardless of node
3352 static int __meminit
next_active_region_index_in_nid(int index
, int nid
)
3354 for (index
= index
+ 1; index
< nr_nodemap_entries
; index
++)
3355 if (nid
== MAX_NUMNODES
|| early_node_map
[index
].nid
== nid
)
3361 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
3363 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
3364 * Architectures may implement their own version but if add_active_range()
3365 * was used and there are no special requirements, this is a convenient
3368 int __meminit
__early_pfn_to_nid(unsigned long pfn
)
3372 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
3373 unsigned long start_pfn
= early_node_map
[i
].start_pfn
;
3374 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
3376 if (start_pfn
<= pfn
&& pfn
< end_pfn
)
3377 return early_node_map
[i
].nid
;
3379 /* This is a memory hole */
3382 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
3384 int __meminit
early_pfn_to_nid(unsigned long pfn
)
3388 nid
= __early_pfn_to_nid(pfn
);
3391 /* just returns 0 */
3395 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
3396 bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
3400 nid
= __early_pfn_to_nid(pfn
);
3401 if (nid
>= 0 && nid
!= node
)
3407 /* Basic iterator support to walk early_node_map[] */
3408 #define for_each_active_range_index_in_nid(i, nid) \
3409 for (i = first_active_region_index_in_nid(nid); i != -1; \
3410 i = next_active_region_index_in_nid(i, nid))
3413 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
3414 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
3415 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
3417 * If an architecture guarantees that all ranges registered with
3418 * add_active_ranges() contain no holes and may be freed, this
3419 * this function may be used instead of calling free_bootmem() manually.
3421 void __init
free_bootmem_with_active_regions(int nid
,
3422 unsigned long max_low_pfn
)
3426 for_each_active_range_index_in_nid(i
, nid
) {
3427 unsigned long size_pages
= 0;
3428 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
3430 if (early_node_map
[i
].start_pfn
>= max_low_pfn
)
3433 if (end_pfn
> max_low_pfn
)
3434 end_pfn
= max_low_pfn
;
3436 size_pages
= end_pfn
- early_node_map
[i
].start_pfn
;
3437 free_bootmem_node(NODE_DATA(early_node_map
[i
].nid
),
3438 PFN_PHYS(early_node_map
[i
].start_pfn
),
3439 size_pages
<< PAGE_SHIFT
);
3443 void __init
work_with_active_regions(int nid
, work_fn_t work_fn
, void *data
)
3448 for_each_active_range_index_in_nid(i
, nid
) {
3449 ret
= work_fn(early_node_map
[i
].start_pfn
,
3450 early_node_map
[i
].end_pfn
, data
);
3456 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3457 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3459 * If an architecture guarantees that all ranges registered with
3460 * add_active_ranges() contain no holes and may be freed, this
3461 * function may be used instead of calling memory_present() manually.
3463 void __init
sparse_memory_present_with_active_regions(int nid
)
3467 for_each_active_range_index_in_nid(i
, nid
)
3468 memory_present(early_node_map
[i
].nid
,
3469 early_node_map
[i
].start_pfn
,
3470 early_node_map
[i
].end_pfn
);
3474 * get_pfn_range_for_nid - Return the start and end page frames for a node
3475 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
3476 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
3477 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
3479 * It returns the start and end page frame of a node based on information
3480 * provided by an arch calling add_active_range(). If called for a node
3481 * with no available memory, a warning is printed and the start and end
3484 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
3485 unsigned long *start_pfn
, unsigned long *end_pfn
)
3491 for_each_active_range_index_in_nid(i
, nid
) {
3492 *start_pfn
= min(*start_pfn
, early_node_map
[i
].start_pfn
);
3493 *end_pfn
= max(*end_pfn
, early_node_map
[i
].end_pfn
);
3496 if (*start_pfn
== -1UL)
3501 * This finds a zone that can be used for ZONE_MOVABLE pages. The
3502 * assumption is made that zones within a node are ordered in monotonic
3503 * increasing memory addresses so that the "highest" populated zone is used
3505 static void __init
find_usable_zone_for_movable(void)
3508 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
3509 if (zone_index
== ZONE_MOVABLE
)
3512 if (arch_zone_highest_possible_pfn
[zone_index
] >
3513 arch_zone_lowest_possible_pfn
[zone_index
])
3517 VM_BUG_ON(zone_index
== -1);
3518 movable_zone
= zone_index
;
3522 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
3523 * because it is sized independant of architecture. Unlike the other zones,
3524 * the starting point for ZONE_MOVABLE is not fixed. It may be different
3525 * in each node depending on the size of each node and how evenly kernelcore
3526 * is distributed. This helper function adjusts the zone ranges
3527 * provided by the architecture for a given node by using the end of the
3528 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
3529 * zones within a node are in order of monotonic increases memory addresses
3531 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
3532 unsigned long zone_type
,
3533 unsigned long node_start_pfn
,
3534 unsigned long node_end_pfn
,
3535 unsigned long *zone_start_pfn
,
3536 unsigned long *zone_end_pfn
)
3538 /* Only adjust if ZONE_MOVABLE is on this node */
3539 if (zone_movable_pfn
[nid
]) {
3540 /* Size ZONE_MOVABLE */
3541 if (zone_type
== ZONE_MOVABLE
) {
3542 *zone_start_pfn
= zone_movable_pfn
[nid
];
3543 *zone_end_pfn
= min(node_end_pfn
,
3544 arch_zone_highest_possible_pfn
[movable_zone
]);
3546 /* Adjust for ZONE_MOVABLE starting within this range */
3547 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
3548 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
3549 *zone_end_pfn
= zone_movable_pfn
[nid
];
3551 /* Check if this whole range is within ZONE_MOVABLE */
3552 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
3553 *zone_start_pfn
= *zone_end_pfn
;
3558 * Return the number of pages a zone spans in a node, including holes
3559 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
3561 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3562 unsigned long zone_type
,
3563 unsigned long *ignored
)
3565 unsigned long node_start_pfn
, node_end_pfn
;
3566 unsigned long zone_start_pfn
, zone_end_pfn
;
3568 /* Get the start and end of the node and zone */
3569 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3570 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
3571 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
3572 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3573 node_start_pfn
, node_end_pfn
,
3574 &zone_start_pfn
, &zone_end_pfn
);
3576 /* Check that this node has pages within the zone's required range */
3577 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
3580 /* Move the zone boundaries inside the node if necessary */
3581 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
3582 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
3584 /* Return the spanned pages */
3585 return zone_end_pfn
- zone_start_pfn
;
3589 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
3590 * then all holes in the requested range will be accounted for.
3592 static unsigned long __meminit
__absent_pages_in_range(int nid
,
3593 unsigned long range_start_pfn
,
3594 unsigned long range_end_pfn
)
3597 unsigned long prev_end_pfn
= 0, hole_pages
= 0;
3598 unsigned long start_pfn
;
3600 /* Find the end_pfn of the first active range of pfns in the node */
3601 i
= first_active_region_index_in_nid(nid
);
3605 prev_end_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3607 /* Account for ranges before physical memory on this node */
3608 if (early_node_map
[i
].start_pfn
> range_start_pfn
)
3609 hole_pages
= prev_end_pfn
- range_start_pfn
;
3611 /* Find all holes for the zone within the node */
3612 for (; i
!= -1; i
= next_active_region_index_in_nid(i
, nid
)) {
3614 /* No need to continue if prev_end_pfn is outside the zone */
3615 if (prev_end_pfn
>= range_end_pfn
)
3618 /* Make sure the end of the zone is not within the hole */
3619 start_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3620 prev_end_pfn
= max(prev_end_pfn
, range_start_pfn
);
3622 /* Update the hole size cound and move on */
3623 if (start_pfn
> range_start_pfn
) {
3624 BUG_ON(prev_end_pfn
> start_pfn
);
3625 hole_pages
+= start_pfn
- prev_end_pfn
;
3627 prev_end_pfn
= early_node_map
[i
].end_pfn
;
3630 /* Account for ranges past physical memory on this node */
3631 if (range_end_pfn
> prev_end_pfn
)
3632 hole_pages
+= range_end_pfn
-
3633 max(range_start_pfn
, prev_end_pfn
);
3639 * absent_pages_in_range - Return number of page frames in holes within a range
3640 * @start_pfn: The start PFN to start searching for holes
3641 * @end_pfn: The end PFN to stop searching for holes
3643 * It returns the number of pages frames in memory holes within a range.
3645 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
3646 unsigned long end_pfn
)
3648 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
3651 /* Return the number of page frames in holes in a zone on a node */
3652 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
3653 unsigned long zone_type
,
3654 unsigned long *ignored
)
3656 unsigned long node_start_pfn
, node_end_pfn
;
3657 unsigned long zone_start_pfn
, zone_end_pfn
;
3659 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3660 zone_start_pfn
= max(arch_zone_lowest_possible_pfn
[zone_type
],
3662 zone_end_pfn
= min(arch_zone_highest_possible_pfn
[zone_type
],
3665 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3666 node_start_pfn
, node_end_pfn
,
3667 &zone_start_pfn
, &zone_end_pfn
);
3668 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
3672 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3673 unsigned long zone_type
,
3674 unsigned long *zones_size
)
3676 return zones_size
[zone_type
];
3679 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
3680 unsigned long zone_type
,
3681 unsigned long *zholes_size
)
3686 return zholes_size
[zone_type
];
3691 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
3692 unsigned long *zones_size
, unsigned long *zholes_size
)
3694 unsigned long realtotalpages
, totalpages
= 0;
3697 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3698 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
3700 pgdat
->node_spanned_pages
= totalpages
;
3702 realtotalpages
= totalpages
;
3703 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3705 zone_absent_pages_in_node(pgdat
->node_id
, i
,
3707 pgdat
->node_present_pages
= realtotalpages
;
3708 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
3712 #ifndef CONFIG_SPARSEMEM
3714 * Calculate the size of the zone->blockflags rounded to an unsigned long
3715 * Start by making sure zonesize is a multiple of pageblock_order by rounding
3716 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
3717 * round what is now in bits to nearest long in bits, then return it in
3720 static unsigned long __init
usemap_size(unsigned long zonesize
)
3722 unsigned long usemapsize
;
3724 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
3725 usemapsize
= usemapsize
>> pageblock_order
;
3726 usemapsize
*= NR_PAGEBLOCK_BITS
;
3727 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
3729 return usemapsize
/ 8;
3732 static void __init
setup_usemap(struct pglist_data
*pgdat
,
3733 struct zone
*zone
, unsigned long zonesize
)
3735 unsigned long usemapsize
= usemap_size(zonesize
);
3736 zone
->pageblock_flags
= NULL
;
3738 zone
->pageblock_flags
= alloc_bootmem_node(pgdat
, usemapsize
);
3741 static void inline setup_usemap(struct pglist_data
*pgdat
,
3742 struct zone
*zone
, unsigned long zonesize
) {}
3743 #endif /* CONFIG_SPARSEMEM */
3745 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3747 /* Return a sensible default order for the pageblock size. */
3748 static inline int pageblock_default_order(void)
3750 if (HPAGE_SHIFT
> PAGE_SHIFT
)
3751 return HUGETLB_PAGE_ORDER
;
3756 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
3757 static inline void __init
set_pageblock_order(unsigned int order
)
3759 /* Check that pageblock_nr_pages has not already been setup */
3760 if (pageblock_order
)
3764 * Assume the largest contiguous order of interest is a huge page.
3765 * This value may be variable depending on boot parameters on IA64
3767 pageblock_order
= order
;
3769 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3772 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
3773 * and pageblock_default_order() are unused as pageblock_order is set
3774 * at compile-time. See include/linux/pageblock-flags.h for the values of
3775 * pageblock_order based on the kernel config
3777 static inline int pageblock_default_order(unsigned int order
)
3781 #define set_pageblock_order(x) do {} while (0)
3783 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3786 * Set up the zone data structures:
3787 * - mark all pages reserved
3788 * - mark all memory queues empty
3789 * - clear the memory bitmaps
3791 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
,
3792 unsigned long *zones_size
, unsigned long *zholes_size
)
3795 int nid
= pgdat
->node_id
;
3796 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
3799 pgdat_resize_init(pgdat
);
3800 pgdat
->nr_zones
= 0;
3801 init_waitqueue_head(&pgdat
->kswapd_wait
);
3802 pgdat
->kswapd_max_order
= 0;
3803 pgdat_page_cgroup_init(pgdat
);
3805 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
3806 struct zone
*zone
= pgdat
->node_zones
+ j
;
3807 unsigned long size
, realsize
, memmap_pages
;
3810 size
= zone_spanned_pages_in_node(nid
, j
, zones_size
);
3811 realsize
= size
- zone_absent_pages_in_node(nid
, j
,
3815 * Adjust realsize so that it accounts for how much memory
3816 * is used by this zone for memmap. This affects the watermark
3817 * and per-cpu initialisations
3820 PAGE_ALIGN(size
* sizeof(struct page
)) >> PAGE_SHIFT
;
3821 if (realsize
>= memmap_pages
) {
3822 realsize
-= memmap_pages
;
3825 " %s zone: %lu pages used for memmap\n",
3826 zone_names
[j
], memmap_pages
);
3829 " %s zone: %lu pages exceeds realsize %lu\n",
3830 zone_names
[j
], memmap_pages
, realsize
);
3832 /* Account for reserved pages */
3833 if (j
== 0 && realsize
> dma_reserve
) {
3834 realsize
-= dma_reserve
;
3835 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
3836 zone_names
[0], dma_reserve
);
3839 if (!is_highmem_idx(j
))
3840 nr_kernel_pages
+= realsize
;
3841 nr_all_pages
+= realsize
;
3843 zone
->spanned_pages
= size
;
3844 zone
->present_pages
= realsize
;
3847 zone
->min_unmapped_pages
= (realsize
*sysctl_min_unmapped_ratio
)
3849 zone
->min_slab_pages
= (realsize
* sysctl_min_slab_ratio
) / 100;
3851 zone
->name
= zone_names
[j
];
3852 spin_lock_init(&zone
->lock
);
3853 spin_lock_init(&zone
->lru_lock
);
3854 zone_seqlock_init(zone
);
3855 zone
->zone_pgdat
= pgdat
;
3857 zone
->prev_priority
= DEF_PRIORITY
;
3859 zone_pcp_init(zone
);
3861 INIT_LIST_HEAD(&zone
->lru
[l
].list
);
3862 zone
->reclaim_stat
.nr_saved_scan
[l
] = 0;
3864 zone
->reclaim_stat
.recent_rotated
[0] = 0;
3865 zone
->reclaim_stat
.recent_rotated
[1] = 0;
3866 zone
->reclaim_stat
.recent_scanned
[0] = 0;
3867 zone
->reclaim_stat
.recent_scanned
[1] = 0;
3868 zap_zone_vm_stats(zone
);
3873 set_pageblock_order(pageblock_default_order());
3874 setup_usemap(pgdat
, zone
, size
);
3875 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
3876 size
, MEMMAP_EARLY
);
3878 memmap_init(size
, nid
, j
, zone_start_pfn
);
3879 zone_start_pfn
+= size
;
3883 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
3885 /* Skip empty nodes */
3886 if (!pgdat
->node_spanned_pages
)
3889 #ifdef CONFIG_FLAT_NODE_MEM_MAP
3890 /* ia64 gets its own node_mem_map, before this, without bootmem */
3891 if (!pgdat
->node_mem_map
) {
3892 unsigned long size
, start
, end
;
3896 * The zone's endpoints aren't required to be MAX_ORDER
3897 * aligned but the node_mem_map endpoints must be in order
3898 * for the buddy allocator to function correctly.
3900 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
3901 end
= pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
3902 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
3903 size
= (end
- start
) * sizeof(struct page
);
3904 map
= alloc_remap(pgdat
->node_id
, size
);
3906 map
= alloc_bootmem_node(pgdat
, size
);
3907 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
3909 #ifndef CONFIG_NEED_MULTIPLE_NODES
3911 * With no DISCONTIG, the global mem_map is just set as node 0's
3913 if (pgdat
== NODE_DATA(0)) {
3914 mem_map
= NODE_DATA(0)->node_mem_map
;
3915 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3916 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
3917 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
3918 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
3921 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
3924 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
3925 unsigned long node_start_pfn
, unsigned long *zholes_size
)
3927 pg_data_t
*pgdat
= NODE_DATA(nid
);
3929 pgdat
->node_id
= nid
;
3930 pgdat
->node_start_pfn
= node_start_pfn
;
3931 calculate_node_totalpages(pgdat
, zones_size
, zholes_size
);
3933 alloc_node_mem_map(pgdat
);
3934 #ifdef CONFIG_FLAT_NODE_MEM_MAP
3935 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
3936 nid
, (unsigned long)pgdat
,
3937 (unsigned long)pgdat
->node_mem_map
);
3940 free_area_init_core(pgdat
, zones_size
, zholes_size
);
3943 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3945 #if MAX_NUMNODES > 1
3947 * Figure out the number of possible node ids.
3949 static void __init
setup_nr_node_ids(void)
3952 unsigned int highest
= 0;
3954 for_each_node_mask(node
, node_possible_map
)
3956 nr_node_ids
= highest
+ 1;
3959 static inline void setup_nr_node_ids(void)
3965 * add_active_range - Register a range of PFNs backed by physical memory
3966 * @nid: The node ID the range resides on
3967 * @start_pfn: The start PFN of the available physical memory
3968 * @end_pfn: The end PFN of the available physical memory
3970 * These ranges are stored in an early_node_map[] and later used by
3971 * free_area_init_nodes() to calculate zone sizes and holes. If the
3972 * range spans a memory hole, it is up to the architecture to ensure
3973 * the memory is not freed by the bootmem allocator. If possible
3974 * the range being registered will be merged with existing ranges.
3976 void __init
add_active_range(unsigned int nid
, unsigned long start_pfn
,
3977 unsigned long end_pfn
)
3981 mminit_dprintk(MMINIT_TRACE
, "memory_register",
3982 "Entering add_active_range(%d, %#lx, %#lx) "
3983 "%d entries of %d used\n",
3984 nid
, start_pfn
, end_pfn
,
3985 nr_nodemap_entries
, MAX_ACTIVE_REGIONS
);
3987 mminit_validate_memmodel_limits(&start_pfn
, &end_pfn
);
3989 /* Merge with existing active regions if possible */
3990 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
3991 if (early_node_map
[i
].nid
!= nid
)
3994 /* Skip if an existing region covers this new one */
3995 if (start_pfn
>= early_node_map
[i
].start_pfn
&&
3996 end_pfn
<= early_node_map
[i
].end_pfn
)
3999 /* Merge forward if suitable */
4000 if (start_pfn
<= early_node_map
[i
].end_pfn
&&
4001 end_pfn
> early_node_map
[i
].end_pfn
) {
4002 early_node_map
[i
].end_pfn
= end_pfn
;
4006 /* Merge backward if suitable */
4007 if (start_pfn
< early_node_map
[i
].end_pfn
&&
4008 end_pfn
>= early_node_map
[i
].start_pfn
) {
4009 early_node_map
[i
].start_pfn
= start_pfn
;
4014 /* Check that early_node_map is large enough */
4015 if (i
>= MAX_ACTIVE_REGIONS
) {
4016 printk(KERN_CRIT
"More than %d memory regions, truncating\n",
4017 MAX_ACTIVE_REGIONS
);
4021 early_node_map
[i
].nid
= nid
;
4022 early_node_map
[i
].start_pfn
= start_pfn
;
4023 early_node_map
[i
].end_pfn
= end_pfn
;
4024 nr_nodemap_entries
= i
+ 1;
4028 * remove_active_range - Shrink an existing registered range of PFNs
4029 * @nid: The node id the range is on that should be shrunk
4030 * @start_pfn: The new PFN of the range
4031 * @end_pfn: The new PFN of the range
4033 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
4034 * The map is kept near the end physical page range that has already been
4035 * registered. This function allows an arch to shrink an existing registered
4038 void __init
remove_active_range(unsigned int nid
, unsigned long start_pfn
,
4039 unsigned long end_pfn
)
4044 printk(KERN_DEBUG
"remove_active_range (%d, %lu, %lu)\n",
4045 nid
, start_pfn
, end_pfn
);
4047 /* Find the old active region end and shrink */
4048 for_each_active_range_index_in_nid(i
, nid
) {
4049 if (early_node_map
[i
].start_pfn
>= start_pfn
&&
4050 early_node_map
[i
].end_pfn
<= end_pfn
) {
4052 early_node_map
[i
].start_pfn
= 0;
4053 early_node_map
[i
].end_pfn
= 0;
4057 if (early_node_map
[i
].start_pfn
< start_pfn
&&
4058 early_node_map
[i
].end_pfn
> start_pfn
) {
4059 unsigned long temp_end_pfn
= early_node_map
[i
].end_pfn
;
4060 early_node_map
[i
].end_pfn
= start_pfn
;
4061 if (temp_end_pfn
> end_pfn
)
4062 add_active_range(nid
, end_pfn
, temp_end_pfn
);
4065 if (early_node_map
[i
].start_pfn
>= start_pfn
&&
4066 early_node_map
[i
].end_pfn
> end_pfn
&&
4067 early_node_map
[i
].start_pfn
< end_pfn
) {
4068 early_node_map
[i
].start_pfn
= end_pfn
;
4076 /* remove the blank ones */
4077 for (i
= nr_nodemap_entries
- 1; i
> 0; i
--) {
4078 if (early_node_map
[i
].nid
!= nid
)
4080 if (early_node_map
[i
].end_pfn
)
4082 /* we found it, get rid of it */
4083 for (j
= i
; j
< nr_nodemap_entries
- 1; j
++)
4084 memcpy(&early_node_map
[j
], &early_node_map
[j
+1],
4085 sizeof(early_node_map
[j
]));
4086 j
= nr_nodemap_entries
- 1;
4087 memset(&early_node_map
[j
], 0, sizeof(early_node_map
[j
]));
4088 nr_nodemap_entries
--;
4093 * remove_all_active_ranges - Remove all currently registered regions
4095 * During discovery, it may be found that a table like SRAT is invalid
4096 * and an alternative discovery method must be used. This function removes
4097 * all currently registered regions.
4099 void __init
remove_all_active_ranges(void)
4101 memset(early_node_map
, 0, sizeof(early_node_map
));
4102 nr_nodemap_entries
= 0;
4105 /* Compare two active node_active_regions */
4106 static int __init
cmp_node_active_region(const void *a
, const void *b
)
4108 struct node_active_region
*arange
= (struct node_active_region
*)a
;
4109 struct node_active_region
*brange
= (struct node_active_region
*)b
;
4111 /* Done this way to avoid overflows */
4112 if (arange
->start_pfn
> brange
->start_pfn
)
4114 if (arange
->start_pfn
< brange
->start_pfn
)
4120 /* sort the node_map by start_pfn */
4121 static void __init
sort_node_map(void)
4123 sort(early_node_map
, (size_t)nr_nodemap_entries
,
4124 sizeof(struct node_active_region
),
4125 cmp_node_active_region
, NULL
);
4128 /* Find the lowest pfn for a node */
4129 static unsigned long __init
find_min_pfn_for_node(int nid
)
4132 unsigned long min_pfn
= ULONG_MAX
;
4134 /* Assuming a sorted map, the first range found has the starting pfn */
4135 for_each_active_range_index_in_nid(i
, nid
)
4136 min_pfn
= min(min_pfn
, early_node_map
[i
].start_pfn
);
4138 if (min_pfn
== ULONG_MAX
) {
4140 "Could not find start_pfn for node %d\n", nid
);
4148 * find_min_pfn_with_active_regions - Find the minimum PFN registered
4150 * It returns the minimum PFN based on information provided via
4151 * add_active_range().
4153 unsigned long __init
find_min_pfn_with_active_regions(void)
4155 return find_min_pfn_for_node(MAX_NUMNODES
);
4159 * early_calculate_totalpages()
4160 * Sum pages in active regions for movable zone.
4161 * Populate N_HIGH_MEMORY for calculating usable_nodes.
4163 static unsigned long __init
early_calculate_totalpages(void)
4166 unsigned long totalpages
= 0;
4168 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
4169 unsigned long pages
= early_node_map
[i
].end_pfn
-
4170 early_node_map
[i
].start_pfn
;
4171 totalpages
+= pages
;
4173 node_set_state(early_node_map
[i
].nid
, N_HIGH_MEMORY
);
4179 * Find the PFN the Movable zone begins in each node. Kernel memory
4180 * is spread evenly between nodes as long as the nodes have enough
4181 * memory. When they don't, some nodes will have more kernelcore than
4184 static void __init
find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn
)
4187 unsigned long usable_startpfn
;
4188 unsigned long kernelcore_node
, kernelcore_remaining
;
4189 /* save the state before borrow the nodemask */
4190 nodemask_t saved_node_state
= node_states
[N_HIGH_MEMORY
];
4191 unsigned long totalpages
= early_calculate_totalpages();
4192 int usable_nodes
= nodes_weight(node_states
[N_HIGH_MEMORY
]);
4195 * If movablecore was specified, calculate what size of
4196 * kernelcore that corresponds so that memory usable for
4197 * any allocation type is evenly spread. If both kernelcore
4198 * and movablecore are specified, then the value of kernelcore
4199 * will be used for required_kernelcore if it's greater than
4200 * what movablecore would have allowed.
4202 if (required_movablecore
) {
4203 unsigned long corepages
;
4206 * Round-up so that ZONE_MOVABLE is at least as large as what
4207 * was requested by the user
4209 required_movablecore
=
4210 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
4211 corepages
= totalpages
- required_movablecore
;
4213 required_kernelcore
= max(required_kernelcore
, corepages
);
4216 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
4217 if (!required_kernelcore
)
4220 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
4221 find_usable_zone_for_movable();
4222 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
4225 /* Spread kernelcore memory as evenly as possible throughout nodes */
4226 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4227 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4229 * Recalculate kernelcore_node if the division per node
4230 * now exceeds what is necessary to satisfy the requested
4231 * amount of memory for the kernel
4233 if (required_kernelcore
< kernelcore_node
)
4234 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4237 * As the map is walked, we track how much memory is usable
4238 * by the kernel using kernelcore_remaining. When it is
4239 * 0, the rest of the node is usable by ZONE_MOVABLE
4241 kernelcore_remaining
= kernelcore_node
;
4243 /* Go through each range of PFNs within this node */
4244 for_each_active_range_index_in_nid(i
, nid
) {
4245 unsigned long start_pfn
, end_pfn
;
4246 unsigned long size_pages
;
4248 start_pfn
= max(early_node_map
[i
].start_pfn
,
4249 zone_movable_pfn
[nid
]);
4250 end_pfn
= early_node_map
[i
].end_pfn
;
4251 if (start_pfn
>= end_pfn
)
4254 /* Account for what is only usable for kernelcore */
4255 if (start_pfn
< usable_startpfn
) {
4256 unsigned long kernel_pages
;
4257 kernel_pages
= min(end_pfn
, usable_startpfn
)
4260 kernelcore_remaining
-= min(kernel_pages
,
4261 kernelcore_remaining
);
4262 required_kernelcore
-= min(kernel_pages
,
4263 required_kernelcore
);
4265 /* Continue if range is now fully accounted */
4266 if (end_pfn
<= usable_startpfn
) {
4269 * Push zone_movable_pfn to the end so
4270 * that if we have to rebalance
4271 * kernelcore across nodes, we will
4272 * not double account here
4274 zone_movable_pfn
[nid
] = end_pfn
;
4277 start_pfn
= usable_startpfn
;
4281 * The usable PFN range for ZONE_MOVABLE is from
4282 * start_pfn->end_pfn. Calculate size_pages as the
4283 * number of pages used as kernelcore
4285 size_pages
= end_pfn
- start_pfn
;
4286 if (size_pages
> kernelcore_remaining
)
4287 size_pages
= kernelcore_remaining
;
4288 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
4291 * Some kernelcore has been met, update counts and
4292 * break if the kernelcore for this node has been
4295 required_kernelcore
-= min(required_kernelcore
,
4297 kernelcore_remaining
-= size_pages
;
4298 if (!kernelcore_remaining
)
4304 * If there is still required_kernelcore, we do another pass with one
4305 * less node in the count. This will push zone_movable_pfn[nid] further
4306 * along on the nodes that still have memory until kernelcore is
4310 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
4313 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
4314 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
4315 zone_movable_pfn
[nid
] =
4316 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
4319 /* restore the node_state */
4320 node_states
[N_HIGH_MEMORY
] = saved_node_state
;
4323 /* Any regular memory on that node ? */
4324 static void check_for_regular_memory(pg_data_t
*pgdat
)
4326 #ifdef CONFIG_HIGHMEM
4327 enum zone_type zone_type
;
4329 for (zone_type
= 0; zone_type
<= ZONE_NORMAL
; zone_type
++) {
4330 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4331 if (zone
->present_pages
)
4332 node_set_state(zone_to_nid(zone
), N_NORMAL_MEMORY
);
4338 * free_area_init_nodes - Initialise all pg_data_t and zone data
4339 * @max_zone_pfn: an array of max PFNs for each zone
4341 * This will call free_area_init_node() for each active node in the system.
4342 * Using the page ranges provided by add_active_range(), the size of each
4343 * zone in each node and their holes is calculated. If the maximum PFN
4344 * between two adjacent zones match, it is assumed that the zone is empty.
4345 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
4346 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
4347 * starts where the previous one ended. For example, ZONE_DMA32 starts
4348 * at arch_max_dma_pfn.
4350 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
4355 /* Sort early_node_map as initialisation assumes it is sorted */
4358 /* Record where the zone boundaries are */
4359 memset(arch_zone_lowest_possible_pfn
, 0,
4360 sizeof(arch_zone_lowest_possible_pfn
));
4361 memset(arch_zone_highest_possible_pfn
, 0,
4362 sizeof(arch_zone_highest_possible_pfn
));
4363 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
4364 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
4365 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
4366 if (i
== ZONE_MOVABLE
)
4368 arch_zone_lowest_possible_pfn
[i
] =
4369 arch_zone_highest_possible_pfn
[i
-1];
4370 arch_zone_highest_possible_pfn
[i
] =
4371 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
4373 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
4374 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
4376 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
4377 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
4378 find_zone_movable_pfns_for_nodes(zone_movable_pfn
);
4380 /* Print out the zone ranges */
4381 printk("Zone PFN ranges:\n");
4382 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4383 if (i
== ZONE_MOVABLE
)
4385 printk(" %-8s %0#10lx -> %0#10lx\n",
4387 arch_zone_lowest_possible_pfn
[i
],
4388 arch_zone_highest_possible_pfn
[i
]);
4391 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
4392 printk("Movable zone start PFN for each node\n");
4393 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
4394 if (zone_movable_pfn
[i
])
4395 printk(" Node %d: %lu\n", i
, zone_movable_pfn
[i
]);
4398 /* Print out the early_node_map[] */
4399 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries
);
4400 for (i
= 0; i
< nr_nodemap_entries
; i
++)
4401 printk(" %3d: %0#10lx -> %0#10lx\n", early_node_map
[i
].nid
,
4402 early_node_map
[i
].start_pfn
,
4403 early_node_map
[i
].end_pfn
);
4405 /* Initialise every node */
4406 mminit_verify_pageflags_layout();
4407 setup_nr_node_ids();
4408 for_each_online_node(nid
) {
4409 pg_data_t
*pgdat
= NODE_DATA(nid
);
4410 free_area_init_node(nid
, NULL
,
4411 find_min_pfn_for_node(nid
), NULL
);
4413 /* Any memory on that node */
4414 if (pgdat
->node_present_pages
)
4415 node_set_state(nid
, N_HIGH_MEMORY
);
4416 check_for_regular_memory(pgdat
);
4420 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
4422 unsigned long long coremem
;
4426 coremem
= memparse(p
, &p
);
4427 *core
= coremem
>> PAGE_SHIFT
;
4429 /* Paranoid check that UL is enough for the coremem value */
4430 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
4436 * kernelcore=size sets the amount of memory for use for allocations that
4437 * cannot be reclaimed or migrated.
4439 static int __init
cmdline_parse_kernelcore(char *p
)
4441 return cmdline_parse_core(p
, &required_kernelcore
);
4445 * movablecore=size sets the amount of memory for use for allocations that
4446 * can be reclaimed or migrated.
4448 static int __init
cmdline_parse_movablecore(char *p
)
4450 return cmdline_parse_core(p
, &required_movablecore
);
4453 early_param("kernelcore", cmdline_parse_kernelcore
);
4454 early_param("movablecore", cmdline_parse_movablecore
);
4456 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
4459 * set_dma_reserve - set the specified number of pages reserved in the first zone
4460 * @new_dma_reserve: The number of pages to mark reserved
4462 * The per-cpu batchsize and zone watermarks are determined by present_pages.
4463 * In the DMA zone, a significant percentage may be consumed by kernel image
4464 * and other unfreeable allocations which can skew the watermarks badly. This
4465 * function may optionally be used to account for unfreeable pages in the
4466 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
4467 * smaller per-cpu batchsize.
4469 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
4471 dma_reserve
= new_dma_reserve
;
4474 #ifndef CONFIG_NEED_MULTIPLE_NODES
4475 struct pglist_data __refdata contig_page_data
= { .bdata
= &bootmem_node_data
[0] };
4476 EXPORT_SYMBOL(contig_page_data
);
4479 void __init
free_area_init(unsigned long *zones_size
)
4481 free_area_init_node(0, zones_size
,
4482 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
4485 static int page_alloc_cpu_notify(struct notifier_block
*self
,
4486 unsigned long action
, void *hcpu
)
4488 int cpu
= (unsigned long)hcpu
;
4490 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
4494 * Spill the event counters of the dead processor
4495 * into the current processors event counters.
4496 * This artificially elevates the count of the current
4499 vm_events_fold_cpu(cpu
);
4502 * Zero the differential counters of the dead processor
4503 * so that the vm statistics are consistent.
4505 * This is only okay since the processor is dead and cannot
4506 * race with what we are doing.
4508 refresh_cpu_vm_stats(cpu
);
4513 void __init
page_alloc_init(void)
4515 hotcpu_notifier(page_alloc_cpu_notify
, 0);
4519 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
4520 * or min_free_kbytes changes.
4522 static void calculate_totalreserve_pages(void)
4524 struct pglist_data
*pgdat
;
4525 unsigned long reserve_pages
= 0;
4526 enum zone_type i
, j
;
4528 for_each_online_pgdat(pgdat
) {
4529 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4530 struct zone
*zone
= pgdat
->node_zones
+ i
;
4531 unsigned long max
= 0;
4533 /* Find valid and maximum lowmem_reserve in the zone */
4534 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
4535 if (zone
->lowmem_reserve
[j
] > max
)
4536 max
= zone
->lowmem_reserve
[j
];
4539 /* we treat the high watermark as reserved pages. */
4540 max
+= high_wmark_pages(zone
);
4542 if (max
> zone
->present_pages
)
4543 max
= zone
->present_pages
;
4544 reserve_pages
+= max
;
4547 totalreserve_pages
= reserve_pages
;
4551 * setup_per_zone_lowmem_reserve - called whenever
4552 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
4553 * has a correct pages reserved value, so an adequate number of
4554 * pages are left in the zone after a successful __alloc_pages().
4556 static void setup_per_zone_lowmem_reserve(void)
4558 struct pglist_data
*pgdat
;
4559 enum zone_type j
, idx
;
4561 for_each_online_pgdat(pgdat
) {
4562 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4563 struct zone
*zone
= pgdat
->node_zones
+ j
;
4564 unsigned long present_pages
= zone
->present_pages
;
4566 zone
->lowmem_reserve
[j
] = 0;
4570 struct zone
*lower_zone
;
4574 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
4575 sysctl_lowmem_reserve_ratio
[idx
] = 1;
4577 lower_zone
= pgdat
->node_zones
+ idx
;
4578 lower_zone
->lowmem_reserve
[j
] = present_pages
/
4579 sysctl_lowmem_reserve_ratio
[idx
];
4580 present_pages
+= lower_zone
->present_pages
;
4585 /* update totalreserve_pages */
4586 calculate_totalreserve_pages();
4590 * setup_per_zone_wmarks - called when min_free_kbytes changes
4591 * or when memory is hot-{added|removed}
4593 * Ensures that the watermark[min,low,high] values for each zone are set
4594 * correctly with respect to min_free_kbytes.
4596 void setup_per_zone_wmarks(void)
4598 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
4599 unsigned long lowmem_pages
= 0;
4601 unsigned long flags
;
4603 /* Calculate total number of !ZONE_HIGHMEM pages */
4604 for_each_zone(zone
) {
4605 if (!is_highmem(zone
))
4606 lowmem_pages
+= zone
->present_pages
;
4609 for_each_zone(zone
) {
4612 spin_lock_irqsave(&zone
->lock
, flags
);
4613 tmp
= (u64
)pages_min
* zone
->present_pages
;
4614 do_div(tmp
, lowmem_pages
);
4615 if (is_highmem(zone
)) {
4617 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
4618 * need highmem pages, so cap pages_min to a small
4621 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
4622 * deltas controls asynch page reclaim, and so should
4623 * not be capped for highmem.
4627 min_pages
= zone
->present_pages
/ 1024;
4628 if (min_pages
< SWAP_CLUSTER_MAX
)
4629 min_pages
= SWAP_CLUSTER_MAX
;
4630 if (min_pages
> 128)
4632 zone
->watermark
[WMARK_MIN
] = min_pages
;
4635 * If it's a lowmem zone, reserve a number of pages
4636 * proportionate to the zone's size.
4638 zone
->watermark
[WMARK_MIN
] = tmp
;
4641 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + (tmp
>> 2);
4642 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + (tmp
>> 1);
4643 setup_zone_migrate_reserve(zone
);
4644 spin_unlock_irqrestore(&zone
->lock
, flags
);
4647 /* update totalreserve_pages */
4648 calculate_totalreserve_pages();
4652 * The inactive anon list should be small enough that the VM never has to
4653 * do too much work, but large enough that each inactive page has a chance
4654 * to be referenced again before it is swapped out.
4656 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
4657 * INACTIVE_ANON pages on this zone's LRU, maintained by the
4658 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
4659 * the anonymous pages are kept on the inactive list.
4662 * memory ratio inactive anon
4663 * -------------------------------------
4672 void calculate_zone_inactive_ratio(struct zone
*zone
)
4674 unsigned int gb
, ratio
;
4676 /* Zone size in gigabytes */
4677 gb
= zone
->present_pages
>> (30 - PAGE_SHIFT
);
4679 ratio
= int_sqrt(10 * gb
);
4683 zone
->inactive_ratio
= ratio
;
4686 static void __init
setup_per_zone_inactive_ratio(void)
4691 calculate_zone_inactive_ratio(zone
);
4695 * Initialise min_free_kbytes.
4697 * For small machines we want it small (128k min). For large machines
4698 * we want it large (64MB max). But it is not linear, because network
4699 * bandwidth does not increase linearly with machine size. We use
4701 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
4702 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
4718 static int __init
init_per_zone_wmark_min(void)
4720 unsigned long lowmem_kbytes
;
4722 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
4724 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
4725 if (min_free_kbytes
< 128)
4726 min_free_kbytes
= 128;
4727 if (min_free_kbytes
> 65536)
4728 min_free_kbytes
= 65536;
4729 setup_per_zone_wmarks();
4730 setup_per_zone_lowmem_reserve();
4731 setup_per_zone_inactive_ratio();
4734 module_init(init_per_zone_wmark_min
)
4737 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
4738 * that we can call two helper functions whenever min_free_kbytes
4741 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
4742 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4744 proc_dointvec(table
, write
, buffer
, length
, ppos
);
4746 setup_per_zone_wmarks();
4751 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
4752 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4757 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
4762 zone
->min_unmapped_pages
= (zone
->present_pages
*
4763 sysctl_min_unmapped_ratio
) / 100;
4767 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
4768 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4773 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
4778 zone
->min_slab_pages
= (zone
->present_pages
*
4779 sysctl_min_slab_ratio
) / 100;
4785 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
4786 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
4787 * whenever sysctl_lowmem_reserve_ratio changes.
4789 * The reserve ratio obviously has absolutely no relation with the
4790 * minimum watermarks. The lowmem reserve ratio can only make sense
4791 * if in function of the boot time zone sizes.
4793 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
4794 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4796 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
4797 setup_per_zone_lowmem_reserve();
4802 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
4803 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
4804 * can have before it gets flushed back to buddy allocator.
4807 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
4808 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4814 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
4815 if (!write
|| (ret
== -EINVAL
))
4817 for_each_populated_zone(zone
) {
4818 for_each_online_cpu(cpu
) {
4820 high
= zone
->present_pages
/ percpu_pagelist_fraction
;
4821 setup_pagelist_highmark(zone_pcp(zone
, cpu
), high
);
4827 int hashdist
= HASHDIST_DEFAULT
;
4830 static int __init
set_hashdist(char *str
)
4834 hashdist
= simple_strtoul(str
, &str
, 0);
4837 __setup("hashdist=", set_hashdist
);
4841 * allocate a large system hash table from bootmem
4842 * - it is assumed that the hash table must contain an exact power-of-2
4843 * quantity of entries
4844 * - limit is the number of hash buckets, not the total allocation size
4846 void *__init
alloc_large_system_hash(const char *tablename
,
4847 unsigned long bucketsize
,
4848 unsigned long numentries
,
4851 unsigned int *_hash_shift
,
4852 unsigned int *_hash_mask
,
4853 unsigned long limit
)
4855 unsigned long long max
= limit
;
4856 unsigned long log2qty
, size
;
4859 /* allow the kernel cmdline to have a say */
4861 /* round applicable memory size up to nearest megabyte */
4862 numentries
= nr_kernel_pages
;
4863 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
4864 numentries
>>= 20 - PAGE_SHIFT
;
4865 numentries
<<= 20 - PAGE_SHIFT
;
4867 /* limit to 1 bucket per 2^scale bytes of low memory */
4868 if (scale
> PAGE_SHIFT
)
4869 numentries
>>= (scale
- PAGE_SHIFT
);
4871 numentries
<<= (PAGE_SHIFT
- scale
);
4873 /* Make sure we've got at least a 0-order allocation.. */
4874 if (unlikely(flags
& HASH_SMALL
)) {
4875 /* Makes no sense without HASH_EARLY */
4876 WARN_ON(!(flags
& HASH_EARLY
));
4877 if (!(numentries
>> *_hash_shift
)) {
4878 numentries
= 1UL << *_hash_shift
;
4879 BUG_ON(!numentries
);
4881 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
4882 numentries
= PAGE_SIZE
/ bucketsize
;
4884 numentries
= roundup_pow_of_two(numentries
);
4886 /* limit allocation size to 1/16 total memory by default */
4888 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
4889 do_div(max
, bucketsize
);
4892 if (numentries
> max
)
4895 log2qty
= ilog2(numentries
);
4898 size
= bucketsize
<< log2qty
;
4899 if (flags
& HASH_EARLY
)
4900 table
= alloc_bootmem_nopanic(size
);
4902 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
4905 * If bucketsize is not a power-of-two, we may free
4906 * some pages at the end of hash table which
4907 * alloc_pages_exact() automatically does
4909 if (get_order(size
) < MAX_ORDER
) {
4910 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
4911 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
4914 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
4917 panic("Failed to allocate %s hash table\n", tablename
);
4919 printk(KERN_INFO
"%s hash table entries: %d (order: %d, %lu bytes)\n",
4922 ilog2(size
) - PAGE_SHIFT
,
4926 *_hash_shift
= log2qty
;
4928 *_hash_mask
= (1 << log2qty
) - 1;
4933 /* Return a pointer to the bitmap storing bits affecting a block of pages */
4934 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
4937 #ifdef CONFIG_SPARSEMEM
4938 return __pfn_to_section(pfn
)->pageblock_flags
;
4940 return zone
->pageblock_flags
;
4941 #endif /* CONFIG_SPARSEMEM */
4944 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
4946 #ifdef CONFIG_SPARSEMEM
4947 pfn
&= (PAGES_PER_SECTION
-1);
4948 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
4950 pfn
= pfn
- zone
->zone_start_pfn
;
4951 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
4952 #endif /* CONFIG_SPARSEMEM */
4956 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4957 * @page: The page within the block of interest
4958 * @start_bitidx: The first bit of interest to retrieve
4959 * @end_bitidx: The last bit of interest
4960 * returns pageblock_bits flags
4962 unsigned long get_pageblock_flags_group(struct page
*page
,
4963 int start_bitidx
, int end_bitidx
)
4966 unsigned long *bitmap
;
4967 unsigned long pfn
, bitidx
;
4968 unsigned long flags
= 0;
4969 unsigned long value
= 1;
4971 zone
= page_zone(page
);
4972 pfn
= page_to_pfn(page
);
4973 bitmap
= get_pageblock_bitmap(zone
, pfn
);
4974 bitidx
= pfn_to_bitidx(zone
, pfn
);
4976 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
4977 if (test_bit(bitidx
+ start_bitidx
, bitmap
))
4984 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
4985 * @page: The page within the block of interest
4986 * @start_bitidx: The first bit of interest
4987 * @end_bitidx: The last bit of interest
4988 * @flags: The flags to set
4990 void set_pageblock_flags_group(struct page
*page
, unsigned long flags
,
4991 int start_bitidx
, int end_bitidx
)
4994 unsigned long *bitmap
;
4995 unsigned long pfn
, bitidx
;
4996 unsigned long value
= 1;
4998 zone
= page_zone(page
);
4999 pfn
= page_to_pfn(page
);
5000 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5001 bitidx
= pfn_to_bitidx(zone
, pfn
);
5002 VM_BUG_ON(pfn
< zone
->zone_start_pfn
);
5003 VM_BUG_ON(pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
);
5005 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5007 __set_bit(bitidx
+ start_bitidx
, bitmap
);
5009 __clear_bit(bitidx
+ start_bitidx
, bitmap
);
5013 * This is designed as sub function...plz see page_isolation.c also.
5014 * set/clear page block's type to be ISOLATE.
5015 * page allocater never alloc memory from ISOLATE block.
5018 int set_migratetype_isolate(struct page
*page
)
5021 unsigned long flags
;
5025 zone
= page_zone(page
);
5026 zone_idx
= zone_idx(zone
);
5027 spin_lock_irqsave(&zone
->lock
, flags
);
5029 * In future, more migrate types will be able to be isolation target.
5031 if (get_pageblock_migratetype(page
) != MIGRATE_MOVABLE
&&
5032 zone_idx
!= ZONE_MOVABLE
)
5034 set_pageblock_migratetype(page
, MIGRATE_ISOLATE
);
5035 move_freepages_block(zone
, page
, MIGRATE_ISOLATE
);
5038 spin_unlock_irqrestore(&zone
->lock
, flags
);
5044 void unset_migratetype_isolate(struct page
*page
)
5047 unsigned long flags
;
5048 zone
= page_zone(page
);
5049 spin_lock_irqsave(&zone
->lock
, flags
);
5050 if (get_pageblock_migratetype(page
) != MIGRATE_ISOLATE
)
5052 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
5053 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
5055 spin_unlock_irqrestore(&zone
->lock
, flags
);
5058 #ifdef CONFIG_MEMORY_HOTREMOVE
5060 * All pages in the range must be isolated before calling this.
5063 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
5069 unsigned long flags
;
5070 /* find the first valid pfn */
5071 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
5076 zone
= page_zone(pfn_to_page(pfn
));
5077 spin_lock_irqsave(&zone
->lock
, flags
);
5079 while (pfn
< end_pfn
) {
5080 if (!pfn_valid(pfn
)) {
5084 page
= pfn_to_page(pfn
);
5085 BUG_ON(page_count(page
));
5086 BUG_ON(!PageBuddy(page
));
5087 order
= page_order(page
);
5088 #ifdef CONFIG_DEBUG_VM
5089 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
5090 pfn
, 1 << order
, end_pfn
);
5092 list_del(&page
->lru
);
5093 rmv_page_order(page
);
5094 zone
->free_area
[order
].nr_free
--;
5095 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
5097 for (i
= 0; i
< (1 << order
); i
++)
5098 SetPageReserved((page
+i
));
5099 pfn
+= (1 << order
);
5101 spin_unlock_irqrestore(&zone
->lock
, flags
);