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/bootmem.h>
23 #include <linux/compiler.h>
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/suspend.h>
27 #include <linux/pagevec.h>
28 #include <linux/blkdev.h>
29 #include <linux/slab.h>
30 #include <linux/oom.h>
31 #include <linux/notifier.h>
32 #include <linux/topology.h>
33 #include <linux/sysctl.h>
34 #include <linux/cpu.h>
35 #include <linux/cpuset.h>
36 #include <linux/memory_hotplug.h>
37 #include <linux/nodemask.h>
38 #include <linux/vmalloc.h>
39 #include <linux/mempolicy.h>
40 #include <linux/stop_machine.h>
41 #include <linux/sort.h>
42 #include <linux/pfn.h>
43 #include <linux/backing-dev.h>
44 #include <linux/fault-inject.h>
45 #include <linux/page-isolation.h>
47 #include <asm/tlbflush.h>
48 #include <asm/div64.h>
52 * Array of node states.
54 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
55 [N_POSSIBLE
] = NODE_MASK_ALL
,
56 [N_ONLINE
] = { { [0] = 1UL } },
58 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
60 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
62 [N_CPU
] = { { [0] = 1UL } },
65 EXPORT_SYMBOL(node_states
);
67 unsigned long totalram_pages __read_mostly
;
68 unsigned long totalreserve_pages __read_mostly
;
70 int percpu_pagelist_fraction
;
72 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
73 int pageblock_order __read_mostly
;
76 static void __free_pages_ok(struct page
*page
, unsigned int order
);
79 * results with 256, 32 in the lowmem_reserve sysctl:
80 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
81 * 1G machine -> (16M dma, 784M normal, 224M high)
82 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
83 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
84 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
86 * TBD: should special case ZONE_DMA32 machines here - in those we normally
87 * don't need any ZONE_NORMAL reservation
89 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
90 #ifdef CONFIG_ZONE_DMA
93 #ifdef CONFIG_ZONE_DMA32
102 EXPORT_SYMBOL(totalram_pages
);
104 static char * const zone_names
[MAX_NR_ZONES
] = {
105 #ifdef CONFIG_ZONE_DMA
108 #ifdef CONFIG_ZONE_DMA32
112 #ifdef CONFIG_HIGHMEM
118 int min_free_kbytes
= 1024;
120 unsigned long __meminitdata nr_kernel_pages
;
121 unsigned long __meminitdata nr_all_pages
;
122 static unsigned long __meminitdata dma_reserve
;
124 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
126 * MAX_ACTIVE_REGIONS determines the maximum number of distinct
127 * ranges of memory (RAM) that may be registered with add_active_range().
128 * Ranges passed to add_active_range() will be merged if possible
129 * so the number of times add_active_range() can be called is
130 * related to the number of nodes and the number of holes
132 #ifdef CONFIG_MAX_ACTIVE_REGIONS
133 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */
134 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
136 #if MAX_NUMNODES >= 32
137 /* If there can be many nodes, allow up to 50 holes per node */
138 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
140 /* By default, allow up to 256 distinct regions */
141 #define MAX_ACTIVE_REGIONS 256
145 static struct node_active_region __meminitdata early_node_map
[MAX_ACTIVE_REGIONS
];
146 static int __meminitdata nr_nodemap_entries
;
147 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
148 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
149 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
150 static unsigned long __meminitdata node_boundary_start_pfn
[MAX_NUMNODES
];
151 static unsigned long __meminitdata node_boundary_end_pfn
[MAX_NUMNODES
];
152 #endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
153 unsigned long __initdata required_kernelcore
;
154 static unsigned long __initdata required_movablecore
;
155 unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
157 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
159 EXPORT_SYMBOL(movable_zone
);
160 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
163 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
164 EXPORT_SYMBOL(nr_node_ids
);
167 int page_group_by_mobility_disabled __read_mostly
;
169 static void set_pageblock_migratetype(struct page
*page
, int migratetype
)
171 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
172 PB_migrate
, PB_migrate_end
);
175 #ifdef CONFIG_DEBUG_VM
176 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
180 unsigned long pfn
= page_to_pfn(page
);
183 seq
= zone_span_seqbegin(zone
);
184 if (pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
186 else if (pfn
< zone
->zone_start_pfn
)
188 } while (zone_span_seqretry(zone
, seq
));
193 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
195 if (!pfn_valid_within(page_to_pfn(page
)))
197 if (zone
!= page_zone(page
))
203 * Temporary debugging check for pages not lying within a given zone.
205 static int bad_range(struct zone
*zone
, struct page
*page
)
207 if (page_outside_zone_boundaries(zone
, page
))
209 if (!page_is_consistent(zone
, page
))
215 static inline int bad_range(struct zone
*zone
, struct page
*page
)
221 static void bad_page(struct page
*page
)
223 printk(KERN_EMERG
"Bad page state in process '%s'\n"
224 KERN_EMERG
"page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n"
225 KERN_EMERG
"Trying to fix it up, but a reboot is needed\n"
226 KERN_EMERG
"Backtrace:\n",
227 current
->comm
, page
, (int)(2*sizeof(unsigned long)),
228 (unsigned long)page
->flags
, page
->mapping
,
229 page_mapcount(page
), page_count(page
));
231 page
->flags
&= ~(1 << PG_lru
|
241 set_page_count(page
, 0);
242 reset_page_mapcount(page
);
243 page
->mapping
= NULL
;
244 add_taint(TAINT_BAD_PAGE
);
248 * Higher-order pages are called "compound pages". They are structured thusly:
250 * The first PAGE_SIZE page is called the "head page".
252 * The remaining PAGE_SIZE pages are called "tail pages".
254 * All pages have PG_compound set. All pages have their ->private pointing at
255 * the head page (even the head page has this).
257 * The first tail page's ->lru.next holds the address of the compound page's
258 * put_page() function. Its ->lru.prev holds the order of allocation.
259 * This usage means that zero-order pages may not be compound.
262 static void free_compound_page(struct page
*page
)
264 __free_pages_ok(page
, compound_order(page
));
267 static void prep_compound_page(struct page
*page
, unsigned long order
)
270 int nr_pages
= 1 << order
;
272 set_compound_page_dtor(page
, free_compound_page
);
273 set_compound_order(page
, order
);
275 for (i
= 1; i
< nr_pages
; i
++) {
276 struct page
*p
= page
+ i
;
279 p
->first_page
= page
;
283 static void destroy_compound_page(struct page
*page
, unsigned long order
)
286 int nr_pages
= 1 << order
;
288 if (unlikely(compound_order(page
) != order
))
291 if (unlikely(!PageHead(page
)))
293 __ClearPageHead(page
);
294 for (i
= 1; i
< nr_pages
; i
++) {
295 struct page
*p
= page
+ i
;
297 if (unlikely(!PageTail(p
) |
298 (p
->first_page
!= page
)))
304 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
309 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
310 * and __GFP_HIGHMEM from hard or soft interrupt context.
312 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
313 for (i
= 0; i
< (1 << order
); i
++)
314 clear_highpage(page
+ i
);
317 static inline void set_page_order(struct page
*page
, int order
)
319 set_page_private(page
, order
);
320 __SetPageBuddy(page
);
323 static inline void rmv_page_order(struct page
*page
)
325 __ClearPageBuddy(page
);
326 set_page_private(page
, 0);
330 * Locate the struct page for both the matching buddy in our
331 * pair (buddy1) and the combined O(n+1) page they form (page).
333 * 1) Any buddy B1 will have an order O twin B2 which satisfies
334 * the following equation:
336 * For example, if the starting buddy (buddy2) is #8 its order
338 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
340 * 2) Any buddy B will have an order O+1 parent P which
341 * satisfies the following equation:
344 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
346 static inline struct page
*
347 __page_find_buddy(struct page
*page
, unsigned long page_idx
, unsigned int order
)
349 unsigned long buddy_idx
= page_idx
^ (1 << order
);
351 return page
+ (buddy_idx
- page_idx
);
354 static inline unsigned long
355 __find_combined_index(unsigned long page_idx
, unsigned int order
)
357 return (page_idx
& ~(1 << order
));
361 * This function checks whether a page is free && is the buddy
362 * we can do coalesce a page and its buddy if
363 * (a) the buddy is not in a hole &&
364 * (b) the buddy is in the buddy system &&
365 * (c) a page and its buddy have the same order &&
366 * (d) a page and its buddy are in the same zone.
368 * For recording whether a page is in the buddy system, we use PG_buddy.
369 * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
371 * For recording page's order, we use page_private(page).
373 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
376 if (!pfn_valid_within(page_to_pfn(buddy
)))
379 if (page_zone_id(page
) != page_zone_id(buddy
))
382 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
383 BUG_ON(page_count(buddy
) != 0);
390 * Freeing function for a buddy system allocator.
392 * The concept of a buddy system is to maintain direct-mapped table
393 * (containing bit values) for memory blocks of various "orders".
394 * The bottom level table contains the map for the smallest allocatable
395 * units of memory (here, pages), and each level above it describes
396 * pairs of units from the levels below, hence, "buddies".
397 * At a high level, all that happens here is marking the table entry
398 * at the bottom level available, and propagating the changes upward
399 * as necessary, plus some accounting needed to play nicely with other
400 * parts of the VM system.
401 * At each level, we keep a list of pages, which are heads of continuous
402 * free pages of length of (1 << order) and marked with PG_buddy. Page's
403 * order is recorded in page_private(page) field.
404 * So when we are allocating or freeing one, we can derive the state of the
405 * other. That is, if we allocate a small block, and both were
406 * free, the remainder of the region must be split into blocks.
407 * If a block is freed, and its buddy is also free, then this
408 * triggers coalescing into a block of larger size.
413 static inline void __free_one_page(struct page
*page
,
414 struct zone
*zone
, unsigned int order
)
416 unsigned long page_idx
;
417 int order_size
= 1 << order
;
418 int migratetype
= get_pageblock_migratetype(page
);
420 if (unlikely(PageCompound(page
)))
421 destroy_compound_page(page
, order
);
423 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
425 VM_BUG_ON(page_idx
& (order_size
- 1));
426 VM_BUG_ON(bad_range(zone
, page
));
428 __mod_zone_page_state(zone
, NR_FREE_PAGES
, order_size
);
429 while (order
< MAX_ORDER
-1) {
430 unsigned long combined_idx
;
433 buddy
= __page_find_buddy(page
, page_idx
, order
);
434 if (!page_is_buddy(page
, buddy
, order
))
435 break; /* Move the buddy up one level. */
437 list_del(&buddy
->lru
);
438 zone
->free_area
[order
].nr_free
--;
439 rmv_page_order(buddy
);
440 combined_idx
= __find_combined_index(page_idx
, order
);
441 page
= page
+ (combined_idx
- page_idx
);
442 page_idx
= combined_idx
;
445 set_page_order(page
, order
);
447 &zone
->free_area
[order
].free_list
[migratetype
]);
448 zone
->free_area
[order
].nr_free
++;
451 static inline int free_pages_check(struct page
*page
)
453 if (unlikely(page_mapcount(page
) |
454 (page
->mapping
!= NULL
) |
455 (page_count(page
) != 0) |
468 __ClearPageDirty(page
);
470 * For now, we report if PG_reserved was found set, but do not
471 * clear it, and do not free the page. But we shall soon need
472 * to do more, for when the ZERO_PAGE count wraps negative.
474 return PageReserved(page
);
478 * Frees a list of pages.
479 * Assumes all pages on list are in same zone, and of same order.
480 * count is the number of pages to free.
482 * If the zone was previously in an "all pages pinned" state then look to
483 * see if this freeing clears that state.
485 * And clear the zone's pages_scanned counter, to hold off the "all pages are
486 * pinned" detection logic.
488 static void free_pages_bulk(struct zone
*zone
, int count
,
489 struct list_head
*list
, int order
)
491 spin_lock(&zone
->lock
);
492 zone_clear_flag(zone
, ZONE_ALL_UNRECLAIMABLE
);
493 zone
->pages_scanned
= 0;
497 VM_BUG_ON(list_empty(list
));
498 page
= list_entry(list
->prev
, struct page
, lru
);
499 /* have to delete it as __free_one_page list manipulates */
500 list_del(&page
->lru
);
501 __free_one_page(page
, zone
, order
);
503 spin_unlock(&zone
->lock
);
506 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
)
508 spin_lock(&zone
->lock
);
509 zone_clear_flag(zone
, ZONE_ALL_UNRECLAIMABLE
);
510 zone
->pages_scanned
= 0;
511 __free_one_page(page
, zone
, order
);
512 spin_unlock(&zone
->lock
);
515 static void __free_pages_ok(struct page
*page
, unsigned int order
)
521 for (i
= 0 ; i
< (1 << order
) ; ++i
)
522 reserved
+= free_pages_check(page
+ i
);
526 if (!PageHighMem(page
))
527 debug_check_no_locks_freed(page_address(page
),PAGE_SIZE
<<order
);
528 arch_free_page(page
, order
);
529 kernel_map_pages(page
, 1 << order
, 0);
531 local_irq_save(flags
);
532 __count_vm_events(PGFREE
, 1 << order
);
533 free_one_page(page_zone(page
), page
, order
);
534 local_irq_restore(flags
);
538 * permit the bootmem allocator to evade page validation on high-order frees
540 void fastcall __init
__free_pages_bootmem(struct page
*page
, unsigned int order
)
543 __ClearPageReserved(page
);
544 set_page_count(page
, 0);
545 set_page_refcounted(page
);
551 for (loop
= 0; loop
< BITS_PER_LONG
; loop
++) {
552 struct page
*p
= &page
[loop
];
554 if (loop
+ 1 < BITS_PER_LONG
)
556 __ClearPageReserved(p
);
557 set_page_count(p
, 0);
560 set_page_refcounted(page
);
561 __free_pages(page
, order
);
567 * The order of subdivision here is critical for the IO subsystem.
568 * Please do not alter this order without good reasons and regression
569 * testing. Specifically, as large blocks of memory are subdivided,
570 * the order in which smaller blocks are delivered depends on the order
571 * they're subdivided in this function. This is the primary factor
572 * influencing the order in which pages are delivered to the IO
573 * subsystem according to empirical testing, and this is also justified
574 * by considering the behavior of a buddy system containing a single
575 * large block of memory acted on by a series of small allocations.
576 * This behavior is a critical factor in sglist merging's success.
580 static inline void expand(struct zone
*zone
, struct page
*page
,
581 int low
, int high
, struct free_area
*area
,
584 unsigned long size
= 1 << high
;
590 VM_BUG_ON(bad_range(zone
, &page
[size
]));
591 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
593 set_page_order(&page
[size
], high
);
598 * This page is about to be returned from the page allocator
600 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
602 if (unlikely(page_mapcount(page
) |
603 (page
->mapping
!= NULL
) |
604 (page_count(page
) != 0) |
619 * For now, we report if PG_reserved was found set, but do not
620 * clear it, and do not allocate the page: as a safety net.
622 if (PageReserved(page
))
625 page
->flags
&= ~(1 << PG_uptodate
| 1 << PG_error
| 1 << PG_readahead
|
626 1 << PG_referenced
| 1 << PG_arch_1
|
627 1 << PG_owner_priv_1
| 1 << PG_mappedtodisk
);
628 set_page_private(page
, 0);
629 set_page_refcounted(page
);
631 arch_alloc_page(page
, order
);
632 kernel_map_pages(page
, 1 << order
, 1);
634 if (gfp_flags
& __GFP_ZERO
)
635 prep_zero_page(page
, order
, gfp_flags
);
637 if (order
&& (gfp_flags
& __GFP_COMP
))
638 prep_compound_page(page
, order
);
644 * Go through the free lists for the given migratetype and remove
645 * the smallest available page from the freelists
647 static struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
650 unsigned int current_order
;
651 struct free_area
* area
;
654 /* Find a page of the appropriate size in the preferred list */
655 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
656 area
= &(zone
->free_area
[current_order
]);
657 if (list_empty(&area
->free_list
[migratetype
]))
660 page
= list_entry(area
->free_list
[migratetype
].next
,
662 list_del(&page
->lru
);
663 rmv_page_order(page
);
665 __mod_zone_page_state(zone
, NR_FREE_PAGES
, - (1UL << order
));
666 expand(zone
, page
, order
, current_order
, area
, migratetype
);
675 * This array describes the order lists are fallen back to when
676 * the free lists for the desirable migrate type are depleted
678 static int fallbacks
[MIGRATE_TYPES
][MIGRATE_TYPES
-1] = {
679 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
680 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
681 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
682 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
, MIGRATE_RESERVE
, MIGRATE_RESERVE
}, /* Never used */
686 * Move the free pages in a range to the free lists of the requested type.
687 * Note that start_page and end_pages are not aligned on a pageblock
688 * boundary. If alignment is required, use move_freepages_block()
690 int move_freepages(struct zone
*zone
,
691 struct page
*start_page
, struct page
*end_page
,
698 #ifndef CONFIG_HOLES_IN_ZONE
700 * page_zone is not safe to call in this context when
701 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
702 * anyway as we check zone boundaries in move_freepages_block().
703 * Remove at a later date when no bug reports exist related to
704 * grouping pages by mobility
706 BUG_ON(page_zone(start_page
) != page_zone(end_page
));
709 for (page
= start_page
; page
<= end_page
;) {
710 if (!pfn_valid_within(page_to_pfn(page
))) {
715 if (!PageBuddy(page
)) {
720 order
= page_order(page
);
721 list_del(&page
->lru
);
723 &zone
->free_area
[order
].free_list
[migratetype
]);
725 pages_moved
+= 1 << order
;
731 int move_freepages_block(struct zone
*zone
, struct page
*page
, int migratetype
)
733 unsigned long start_pfn
, end_pfn
;
734 struct page
*start_page
, *end_page
;
736 start_pfn
= page_to_pfn(page
);
737 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
738 start_page
= pfn_to_page(start_pfn
);
739 end_page
= start_page
+ pageblock_nr_pages
- 1;
740 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
742 /* Do not cross zone boundaries */
743 if (start_pfn
< zone
->zone_start_pfn
)
745 if (end_pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
748 return move_freepages(zone
, start_page
, end_page
, migratetype
);
751 /* Remove an element from the buddy allocator from the fallback list */
752 static struct page
*__rmqueue_fallback(struct zone
*zone
, int order
,
753 int start_migratetype
)
755 struct free_area
* area
;
760 /* Find the largest possible block of pages in the other list */
761 for (current_order
= MAX_ORDER
-1; current_order
>= order
;
763 for (i
= 0; i
< MIGRATE_TYPES
- 1; i
++) {
764 migratetype
= fallbacks
[start_migratetype
][i
];
766 /* MIGRATE_RESERVE handled later if necessary */
767 if (migratetype
== MIGRATE_RESERVE
)
770 area
= &(zone
->free_area
[current_order
]);
771 if (list_empty(&area
->free_list
[migratetype
]))
774 page
= list_entry(area
->free_list
[migratetype
].next
,
779 * If breaking a large block of pages, move all free
780 * pages to the preferred allocation list. If falling
781 * back for a reclaimable kernel allocation, be more
782 * agressive about taking ownership of free pages
784 if (unlikely(current_order
>= (pageblock_order
>> 1)) ||
785 start_migratetype
== MIGRATE_RECLAIMABLE
) {
787 pages
= move_freepages_block(zone
, page
,
790 /* Claim the whole block if over half of it is free */
791 if (pages
>= (1 << (pageblock_order
-1)))
792 set_pageblock_migratetype(page
,
795 migratetype
= start_migratetype
;
798 /* Remove the page from the freelists */
799 list_del(&page
->lru
);
800 rmv_page_order(page
);
801 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
804 if (current_order
== pageblock_order
)
805 set_pageblock_migratetype(page
,
808 expand(zone
, page
, order
, current_order
, area
, migratetype
);
813 /* Use MIGRATE_RESERVE rather than fail an allocation */
814 return __rmqueue_smallest(zone
, order
, MIGRATE_RESERVE
);
818 * Do the hard work of removing an element from the buddy allocator.
819 * Call me with the zone->lock already held.
821 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
826 page
= __rmqueue_smallest(zone
, order
, migratetype
);
829 page
= __rmqueue_fallback(zone
, order
, migratetype
);
835 * Obtain a specified number of elements from the buddy allocator, all under
836 * a single hold of the lock, for efficiency. Add them to the supplied list.
837 * Returns the number of new pages which were placed at *list.
839 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
840 unsigned long count
, struct list_head
*list
,
845 spin_lock(&zone
->lock
);
846 for (i
= 0; i
< count
; ++i
) {
847 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
848 if (unlikely(page
== NULL
))
852 * Split buddy pages returned by expand() are received here
853 * in physical page order. The page is added to the callers and
854 * list and the list head then moves forward. From the callers
855 * perspective, the linked list is ordered by page number in
856 * some conditions. This is useful for IO devices that can
857 * merge IO requests if the physical pages are ordered
860 list_add(&page
->lru
, list
);
861 set_page_private(page
, migratetype
);
864 spin_unlock(&zone
->lock
);
870 * Called from the vmstat counter updater to drain pagesets of this
871 * currently executing processor on remote nodes after they have
874 * Note that this function must be called with the thread pinned to
875 * a single processor.
877 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
882 local_irq_save(flags
);
883 if (pcp
->count
>= pcp
->batch
)
884 to_drain
= pcp
->batch
;
886 to_drain
= pcp
->count
;
887 free_pages_bulk(zone
, to_drain
, &pcp
->list
, 0);
888 pcp
->count
-= to_drain
;
889 local_irq_restore(flags
);
894 * Drain pages of the indicated processor.
896 * The processor must either be the current processor and the
897 * thread pinned to the current processor or a processor that
900 static void drain_pages(unsigned int cpu
)
905 for_each_zone(zone
) {
906 struct per_cpu_pageset
*pset
;
907 struct per_cpu_pages
*pcp
;
909 if (!populated_zone(zone
))
912 pset
= zone_pcp(zone
, cpu
);
915 local_irq_save(flags
);
916 free_pages_bulk(zone
, pcp
->count
, &pcp
->list
, 0);
918 local_irq_restore(flags
);
923 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
925 void drain_local_pages(void *arg
)
927 drain_pages(smp_processor_id());
931 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
933 void drain_all_pages(void)
935 on_each_cpu(drain_local_pages
, NULL
, 0, 1);
938 #ifdef CONFIG_HIBERNATION
940 void mark_free_pages(struct zone
*zone
)
942 unsigned long pfn
, max_zone_pfn
;
945 struct list_head
*curr
;
947 if (!zone
->spanned_pages
)
950 spin_lock_irqsave(&zone
->lock
, flags
);
952 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
953 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
954 if (pfn_valid(pfn
)) {
955 struct page
*page
= pfn_to_page(pfn
);
957 if (!swsusp_page_is_forbidden(page
))
958 swsusp_unset_page_free(page
);
961 for_each_migratetype_order(order
, t
) {
962 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
965 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
966 for (i
= 0; i
< (1UL << order
); i
++)
967 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
970 spin_unlock_irqrestore(&zone
->lock
, flags
);
972 #endif /* CONFIG_PM */
975 * Free a 0-order page
977 static void fastcall
free_hot_cold_page(struct page
*page
, int cold
)
979 struct zone
*zone
= page_zone(page
);
980 struct per_cpu_pages
*pcp
;
984 page
->mapping
= NULL
;
985 if (free_pages_check(page
))
988 if (!PageHighMem(page
))
989 debug_check_no_locks_freed(page_address(page
), PAGE_SIZE
);
990 arch_free_page(page
, 0);
991 kernel_map_pages(page
, 1, 0);
993 pcp
= &zone_pcp(zone
, get_cpu())->pcp
;
994 local_irq_save(flags
);
995 __count_vm_event(PGFREE
);
997 list_add_tail(&page
->lru
, &pcp
->list
);
999 list_add(&page
->lru
, &pcp
->list
);
1000 set_page_private(page
, get_pageblock_migratetype(page
));
1002 if (pcp
->count
>= pcp
->high
) {
1003 free_pages_bulk(zone
, pcp
->batch
, &pcp
->list
, 0);
1004 pcp
->count
-= pcp
->batch
;
1006 local_irq_restore(flags
);
1010 void fastcall
free_hot_page(struct page
*page
)
1012 free_hot_cold_page(page
, 0);
1015 void fastcall
free_cold_page(struct page
*page
)
1017 free_hot_cold_page(page
, 1);
1021 * split_page takes a non-compound higher-order page, and splits it into
1022 * n (1<<order) sub-pages: page[0..n]
1023 * Each sub-page must be freed individually.
1025 * Note: this is probably too low level an operation for use in drivers.
1026 * Please consult with lkml before using this in your driver.
1028 void split_page(struct page
*page
, unsigned int order
)
1032 VM_BUG_ON(PageCompound(page
));
1033 VM_BUG_ON(!page_count(page
));
1034 for (i
= 1; i
< (1 << order
); i
++)
1035 set_page_refcounted(page
+ i
);
1039 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1040 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1043 static struct page
*buffered_rmqueue(struct zonelist
*zonelist
,
1044 struct zone
*zone
, int order
, gfp_t gfp_flags
)
1046 unsigned long flags
;
1048 int cold
= !!(gfp_flags
& __GFP_COLD
);
1050 int migratetype
= allocflags_to_migratetype(gfp_flags
);
1054 if (likely(order
== 0)) {
1055 struct per_cpu_pages
*pcp
;
1057 pcp
= &zone_pcp(zone
, cpu
)->pcp
;
1058 local_irq_save(flags
);
1060 pcp
->count
= rmqueue_bulk(zone
, 0,
1061 pcp
->batch
, &pcp
->list
, migratetype
);
1062 if (unlikely(!pcp
->count
))
1066 /* Find a page of the appropriate migrate type */
1068 list_for_each_entry_reverse(page
, &pcp
->list
, lru
)
1069 if (page_private(page
) == migratetype
)
1072 list_for_each_entry(page
, &pcp
->list
, lru
)
1073 if (page_private(page
) == migratetype
)
1077 /* Allocate more to the pcp list if necessary */
1078 if (unlikely(&page
->lru
== &pcp
->list
)) {
1079 pcp
->count
+= rmqueue_bulk(zone
, 0,
1080 pcp
->batch
, &pcp
->list
, migratetype
);
1081 page
= list_entry(pcp
->list
.next
, struct page
, lru
);
1084 list_del(&page
->lru
);
1087 spin_lock_irqsave(&zone
->lock
, flags
);
1088 page
= __rmqueue(zone
, order
, migratetype
);
1089 spin_unlock(&zone
->lock
);
1094 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
1095 zone_statistics(zonelist
, zone
);
1096 local_irq_restore(flags
);
1099 VM_BUG_ON(bad_range(zone
, page
));
1100 if (prep_new_page(page
, order
, gfp_flags
))
1105 local_irq_restore(flags
);
1110 #define ALLOC_NO_WATERMARKS 0x01 /* don't check watermarks at all */
1111 #define ALLOC_WMARK_MIN 0x02 /* use pages_min watermark */
1112 #define ALLOC_WMARK_LOW 0x04 /* use pages_low watermark */
1113 #define ALLOC_WMARK_HIGH 0x08 /* use pages_high watermark */
1114 #define ALLOC_HARDER 0x10 /* try to alloc harder */
1115 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
1116 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
1118 #ifdef CONFIG_FAIL_PAGE_ALLOC
1120 static struct fail_page_alloc_attr
{
1121 struct fault_attr attr
;
1123 u32 ignore_gfp_highmem
;
1124 u32 ignore_gfp_wait
;
1127 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1129 struct dentry
*ignore_gfp_highmem_file
;
1130 struct dentry
*ignore_gfp_wait_file
;
1131 struct dentry
*min_order_file
;
1133 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1135 } fail_page_alloc
= {
1136 .attr
= FAULT_ATTR_INITIALIZER
,
1137 .ignore_gfp_wait
= 1,
1138 .ignore_gfp_highmem
= 1,
1142 static int __init
setup_fail_page_alloc(char *str
)
1144 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
1146 __setup("fail_page_alloc=", setup_fail_page_alloc
);
1148 static int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1150 if (order
< fail_page_alloc
.min_order
)
1152 if (gfp_mask
& __GFP_NOFAIL
)
1154 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
1156 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
1159 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
1162 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1164 static int __init
fail_page_alloc_debugfs(void)
1166 mode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
1170 err
= init_fault_attr_dentries(&fail_page_alloc
.attr
,
1174 dir
= fail_page_alloc
.attr
.dentries
.dir
;
1176 fail_page_alloc
.ignore_gfp_wait_file
=
1177 debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
1178 &fail_page_alloc
.ignore_gfp_wait
);
1180 fail_page_alloc
.ignore_gfp_highmem_file
=
1181 debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
1182 &fail_page_alloc
.ignore_gfp_highmem
);
1183 fail_page_alloc
.min_order_file
=
1184 debugfs_create_u32("min-order", mode
, dir
,
1185 &fail_page_alloc
.min_order
);
1187 if (!fail_page_alloc
.ignore_gfp_wait_file
||
1188 !fail_page_alloc
.ignore_gfp_highmem_file
||
1189 !fail_page_alloc
.min_order_file
) {
1191 debugfs_remove(fail_page_alloc
.ignore_gfp_wait_file
);
1192 debugfs_remove(fail_page_alloc
.ignore_gfp_highmem_file
);
1193 debugfs_remove(fail_page_alloc
.min_order_file
);
1194 cleanup_fault_attr_dentries(&fail_page_alloc
.attr
);
1200 late_initcall(fail_page_alloc_debugfs
);
1202 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1204 #else /* CONFIG_FAIL_PAGE_ALLOC */
1206 static inline int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1211 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1214 * Return 1 if free pages are above 'mark'. This takes into account the order
1215 * of the allocation.
1217 int zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1218 int classzone_idx
, int alloc_flags
)
1220 /* free_pages my go negative - that's OK */
1222 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
) - (1 << order
) + 1;
1225 if (alloc_flags
& ALLOC_HIGH
)
1227 if (alloc_flags
& ALLOC_HARDER
)
1230 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
1232 for (o
= 0; o
< order
; o
++) {
1233 /* At the next order, this order's pages become unavailable */
1234 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1236 /* Require fewer higher order pages to be free */
1239 if (free_pages
<= min
)
1247 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1248 * skip over zones that are not allowed by the cpuset, or that have
1249 * been recently (in last second) found to be nearly full. See further
1250 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1251 * that have to skip over a lot of full or unallowed zones.
1253 * If the zonelist cache is present in the passed in zonelist, then
1254 * returns a pointer to the allowed node mask (either the current
1255 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1257 * If the zonelist cache is not available for this zonelist, does
1258 * nothing and returns NULL.
1260 * If the fullzones BITMAP in the zonelist cache is stale (more than
1261 * a second since last zap'd) then we zap it out (clear its bits.)
1263 * We hold off even calling zlc_setup, until after we've checked the
1264 * first zone in the zonelist, on the theory that most allocations will
1265 * be satisfied from that first zone, so best to examine that zone as
1266 * quickly as we can.
1268 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1270 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1271 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1273 zlc
= zonelist
->zlcache_ptr
;
1277 if (jiffies
- zlc
->last_full_zap
> 1 * HZ
) {
1278 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1279 zlc
->last_full_zap
= jiffies
;
1282 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1283 &cpuset_current_mems_allowed
:
1284 &node_states
[N_HIGH_MEMORY
];
1285 return allowednodes
;
1289 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1290 * if it is worth looking at further for free memory:
1291 * 1) Check that the zone isn't thought to be full (doesn't have its
1292 * bit set in the zonelist_cache fullzones BITMAP).
1293 * 2) Check that the zones node (obtained from the zonelist_cache
1294 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1295 * Return true (non-zero) if zone is worth looking at further, or
1296 * else return false (zero) if it is not.
1298 * This check -ignores- the distinction between various watermarks,
1299 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1300 * found to be full for any variation of these watermarks, it will
1301 * be considered full for up to one second by all requests, unless
1302 * we are so low on memory on all allowed nodes that we are forced
1303 * into the second scan of the zonelist.
1305 * In the second scan we ignore this zonelist cache and exactly
1306 * apply the watermarks to all zones, even it is slower to do so.
1307 * We are low on memory in the second scan, and should leave no stone
1308 * unturned looking for a free page.
1310 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zone
**z
,
1311 nodemask_t
*allowednodes
)
1313 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1314 int i
; /* index of *z in zonelist zones */
1315 int n
; /* node that zone *z is on */
1317 zlc
= zonelist
->zlcache_ptr
;
1321 i
= z
- zonelist
->zones
;
1324 /* This zone is worth trying if it is allowed but not full */
1325 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1329 * Given 'z' scanning a zonelist, set the corresponding bit in
1330 * zlc->fullzones, so that subsequent attempts to allocate a page
1331 * from that zone don't waste time re-examining it.
1333 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zone
**z
)
1335 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1336 int i
; /* index of *z in zonelist zones */
1338 zlc
= zonelist
->zlcache_ptr
;
1342 i
= z
- zonelist
->zones
;
1344 set_bit(i
, zlc
->fullzones
);
1347 #else /* CONFIG_NUMA */
1349 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1354 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zone
**z
,
1355 nodemask_t
*allowednodes
)
1360 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zone
**z
)
1363 #endif /* CONFIG_NUMA */
1366 * get_page_from_freelist goes through the zonelist trying to allocate
1369 static struct page
*
1370 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
,
1371 struct zonelist
*zonelist
, int alloc_flags
)
1374 struct page
*page
= NULL
;
1375 int classzone_idx
= zone_idx(zonelist
->zones
[0]);
1377 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1378 int zlc_active
= 0; /* set if using zonelist_cache */
1379 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1380 enum zone_type highest_zoneidx
= -1; /* Gets set for policy zonelists */
1384 * Scan zonelist, looking for a zone with enough free.
1385 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1387 z
= zonelist
->zones
;
1391 * In NUMA, this could be a policy zonelist which contains
1392 * zones that may not be allowed by the current gfp_mask.
1393 * Check the zone is allowed by the current flags
1395 if (unlikely(alloc_should_filter_zonelist(zonelist
))) {
1396 if (highest_zoneidx
== -1)
1397 highest_zoneidx
= gfp_zone(gfp_mask
);
1398 if (zone_idx(*z
) > highest_zoneidx
)
1402 if (NUMA_BUILD
&& zlc_active
&&
1403 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1406 if ((alloc_flags
& ALLOC_CPUSET
) &&
1407 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1410 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
1412 if (alloc_flags
& ALLOC_WMARK_MIN
)
1413 mark
= zone
->pages_min
;
1414 else if (alloc_flags
& ALLOC_WMARK_LOW
)
1415 mark
= zone
->pages_low
;
1417 mark
= zone
->pages_high
;
1418 if (!zone_watermark_ok(zone
, order
, mark
,
1419 classzone_idx
, alloc_flags
)) {
1420 if (!zone_reclaim_mode
||
1421 !zone_reclaim(zone
, gfp_mask
, order
))
1422 goto this_zone_full
;
1426 page
= buffered_rmqueue(zonelist
, zone
, order
, gfp_mask
);
1431 zlc_mark_zone_full(zonelist
, z
);
1433 if (NUMA_BUILD
&& !did_zlc_setup
) {
1434 /* we do zlc_setup after the first zone is tried */
1435 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1439 } while (*(++z
) != NULL
);
1441 if (unlikely(NUMA_BUILD
&& page
== NULL
&& zlc_active
)) {
1442 /* Disable zlc cache for second zonelist scan */
1450 * This is the 'heart' of the zoned buddy allocator.
1452 struct page
* fastcall
1453 __alloc_pages(gfp_t gfp_mask
, unsigned int order
,
1454 struct zonelist
*zonelist
)
1456 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
1459 struct reclaim_state reclaim_state
;
1460 struct task_struct
*p
= current
;
1463 int did_some_progress
;
1465 might_sleep_if(wait
);
1467 if (should_fail_alloc_page(gfp_mask
, order
))
1471 z
= zonelist
->zones
; /* the list of zones suitable for gfp_mask */
1473 if (unlikely(*z
== NULL
)) {
1475 * Happens if we have an empty zonelist as a result of
1476 * GFP_THISNODE being used on a memoryless node
1481 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, order
,
1482 zonelist
, ALLOC_WMARK_LOW
|ALLOC_CPUSET
);
1487 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
1488 * __GFP_NOWARN set) should not cause reclaim since the subsystem
1489 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
1490 * using a larger set of nodes after it has established that the
1491 * allowed per node queues are empty and that nodes are
1494 if (NUMA_BUILD
&& (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
1497 for (z
= zonelist
->zones
; *z
; z
++)
1498 wakeup_kswapd(*z
, order
);
1501 * OK, we're below the kswapd watermark and have kicked background
1502 * reclaim. Now things get more complex, so set up alloc_flags according
1503 * to how we want to proceed.
1505 * The caller may dip into page reserves a bit more if the caller
1506 * cannot run direct reclaim, or if the caller has realtime scheduling
1507 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
1508 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1510 alloc_flags
= ALLOC_WMARK_MIN
;
1511 if ((unlikely(rt_task(p
)) && !in_interrupt()) || !wait
)
1512 alloc_flags
|= ALLOC_HARDER
;
1513 if (gfp_mask
& __GFP_HIGH
)
1514 alloc_flags
|= ALLOC_HIGH
;
1516 alloc_flags
|= ALLOC_CPUSET
;
1519 * Go through the zonelist again. Let __GFP_HIGH and allocations
1520 * coming from realtime tasks go deeper into reserves.
1522 * This is the last chance, in general, before the goto nopage.
1523 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1524 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1526 page
= get_page_from_freelist(gfp_mask
, order
, zonelist
, alloc_flags
);
1530 /* This allocation should allow future memory freeing. */
1533 if (((p
->flags
& PF_MEMALLOC
) || unlikely(test_thread_flag(TIF_MEMDIE
)))
1534 && !in_interrupt()) {
1535 if (!(gfp_mask
& __GFP_NOMEMALLOC
)) {
1537 /* go through the zonelist yet again, ignoring mins */
1538 page
= get_page_from_freelist(gfp_mask
, order
,
1539 zonelist
, ALLOC_NO_WATERMARKS
);
1542 if (gfp_mask
& __GFP_NOFAIL
) {
1543 congestion_wait(WRITE
, HZ
/50);
1550 /* Atomic allocations - we can't balance anything */
1556 /* We now go into synchronous reclaim */
1557 cpuset_memory_pressure_bump();
1558 p
->flags
|= PF_MEMALLOC
;
1559 reclaim_state
.reclaimed_slab
= 0;
1560 p
->reclaim_state
= &reclaim_state
;
1562 did_some_progress
= try_to_free_pages(zonelist
->zones
, order
, gfp_mask
);
1564 p
->reclaim_state
= NULL
;
1565 p
->flags
&= ~PF_MEMALLOC
;
1572 if (likely(did_some_progress
)) {
1573 page
= get_page_from_freelist(gfp_mask
, order
,
1574 zonelist
, alloc_flags
);
1577 } else if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
1578 if (!try_set_zone_oom(zonelist
)) {
1579 schedule_timeout_uninterruptible(1);
1584 * Go through the zonelist yet one more time, keep
1585 * very high watermark here, this is only to catch
1586 * a parallel oom killing, we must fail if we're still
1587 * under heavy pressure.
1589 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, order
,
1590 zonelist
, ALLOC_WMARK_HIGH
|ALLOC_CPUSET
);
1592 clear_zonelist_oom(zonelist
);
1596 /* The OOM killer will not help higher order allocs so fail */
1597 if (order
> PAGE_ALLOC_COSTLY_ORDER
) {
1598 clear_zonelist_oom(zonelist
);
1602 out_of_memory(zonelist
, gfp_mask
, order
);
1603 clear_zonelist_oom(zonelist
);
1608 * Don't let big-order allocations loop unless the caller explicitly
1609 * requests that. Wait for some write requests to complete then retry.
1611 * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order
1612 * <= 3, but that may not be true in other implementations.
1615 if (!(gfp_mask
& __GFP_NORETRY
)) {
1616 if ((order
<= PAGE_ALLOC_COSTLY_ORDER
) ||
1617 (gfp_mask
& __GFP_REPEAT
))
1619 if (gfp_mask
& __GFP_NOFAIL
)
1623 congestion_wait(WRITE
, HZ
/50);
1628 if (!(gfp_mask
& __GFP_NOWARN
) && printk_ratelimit()) {
1629 printk(KERN_WARNING
"%s: page allocation failure."
1630 " order:%d, mode:0x%x\n",
1631 p
->comm
, order
, gfp_mask
);
1639 EXPORT_SYMBOL(__alloc_pages
);
1642 * Common helper functions.
1644 fastcall
unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
1647 page
= alloc_pages(gfp_mask
, order
);
1650 return (unsigned long) page_address(page
);
1653 EXPORT_SYMBOL(__get_free_pages
);
1655 fastcall
unsigned long get_zeroed_page(gfp_t gfp_mask
)
1660 * get_zeroed_page() returns a 32-bit address, which cannot represent
1663 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
1665 page
= alloc_pages(gfp_mask
| __GFP_ZERO
, 0);
1667 return (unsigned long) page_address(page
);
1671 EXPORT_SYMBOL(get_zeroed_page
);
1673 void __pagevec_free(struct pagevec
*pvec
)
1675 int i
= pagevec_count(pvec
);
1678 free_hot_cold_page(pvec
->pages
[i
], pvec
->cold
);
1681 fastcall
void __free_pages(struct page
*page
, unsigned int order
)
1683 if (put_page_testzero(page
)) {
1685 free_hot_page(page
);
1687 __free_pages_ok(page
, order
);
1691 EXPORT_SYMBOL(__free_pages
);
1693 fastcall
void free_pages(unsigned long addr
, unsigned int order
)
1696 VM_BUG_ON(!virt_addr_valid((void *)addr
));
1697 __free_pages(virt_to_page((void *)addr
), order
);
1701 EXPORT_SYMBOL(free_pages
);
1703 static unsigned int nr_free_zone_pages(int offset
)
1705 /* Just pick one node, since fallback list is circular */
1706 pg_data_t
*pgdat
= NODE_DATA(numa_node_id());
1707 unsigned int sum
= 0;
1709 struct zonelist
*zonelist
= pgdat
->node_zonelists
+ offset
;
1710 struct zone
**zonep
= zonelist
->zones
;
1713 for (zone
= *zonep
++; zone
; zone
= *zonep
++) {
1714 unsigned long size
= zone
->present_pages
;
1715 unsigned long high
= zone
->pages_high
;
1724 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
1726 unsigned int nr_free_buffer_pages(void)
1728 return nr_free_zone_pages(gfp_zone(GFP_USER
));
1730 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
1733 * Amount of free RAM allocatable within all zones
1735 unsigned int nr_free_pagecache_pages(void)
1737 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
1740 static inline void show_node(struct zone
*zone
)
1743 printk("Node %d ", zone_to_nid(zone
));
1746 void si_meminfo(struct sysinfo
*val
)
1748 val
->totalram
= totalram_pages
;
1750 val
->freeram
= global_page_state(NR_FREE_PAGES
);
1751 val
->bufferram
= nr_blockdev_pages();
1752 val
->totalhigh
= totalhigh_pages
;
1753 val
->freehigh
= nr_free_highpages();
1754 val
->mem_unit
= PAGE_SIZE
;
1757 EXPORT_SYMBOL(si_meminfo
);
1760 void si_meminfo_node(struct sysinfo
*val
, int nid
)
1762 pg_data_t
*pgdat
= NODE_DATA(nid
);
1764 val
->totalram
= pgdat
->node_present_pages
;
1765 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
1766 #ifdef CONFIG_HIGHMEM
1767 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
1768 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
1774 val
->mem_unit
= PAGE_SIZE
;
1778 #define K(x) ((x) << (PAGE_SHIFT-10))
1781 * Show free area list (used inside shift_scroll-lock stuff)
1782 * We also calculate the percentage fragmentation. We do this by counting the
1783 * memory on each free list with the exception of the first item on the list.
1785 void show_free_areas(void)
1790 for_each_zone(zone
) {
1791 if (!populated_zone(zone
))
1795 printk("%s per-cpu:\n", zone
->name
);
1797 for_each_online_cpu(cpu
) {
1798 struct per_cpu_pageset
*pageset
;
1800 pageset
= zone_pcp(zone
, cpu
);
1802 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
1803 cpu
, pageset
->pcp
.high
,
1804 pageset
->pcp
.batch
, pageset
->pcp
.count
);
1808 printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu unstable:%lu\n"
1809 " free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n",
1810 global_page_state(NR_ACTIVE
),
1811 global_page_state(NR_INACTIVE
),
1812 global_page_state(NR_FILE_DIRTY
),
1813 global_page_state(NR_WRITEBACK
),
1814 global_page_state(NR_UNSTABLE_NFS
),
1815 global_page_state(NR_FREE_PAGES
),
1816 global_page_state(NR_SLAB_RECLAIMABLE
) +
1817 global_page_state(NR_SLAB_UNRECLAIMABLE
),
1818 global_page_state(NR_FILE_MAPPED
),
1819 global_page_state(NR_PAGETABLE
),
1820 global_page_state(NR_BOUNCE
));
1822 for_each_zone(zone
) {
1825 if (!populated_zone(zone
))
1837 " pages_scanned:%lu"
1838 " all_unreclaimable? %s"
1841 K(zone_page_state(zone
, NR_FREE_PAGES
)),
1844 K(zone
->pages_high
),
1845 K(zone_page_state(zone
, NR_ACTIVE
)),
1846 K(zone_page_state(zone
, NR_INACTIVE
)),
1847 K(zone
->present_pages
),
1848 zone
->pages_scanned
,
1849 (zone_is_all_unreclaimable(zone
) ? "yes" : "no")
1851 printk("lowmem_reserve[]:");
1852 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
1853 printk(" %lu", zone
->lowmem_reserve
[i
]);
1857 for_each_zone(zone
) {
1858 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
1860 if (!populated_zone(zone
))
1864 printk("%s: ", zone
->name
);
1866 spin_lock_irqsave(&zone
->lock
, flags
);
1867 for (order
= 0; order
< MAX_ORDER
; order
++) {
1868 nr
[order
] = zone
->free_area
[order
].nr_free
;
1869 total
+= nr
[order
] << order
;
1871 spin_unlock_irqrestore(&zone
->lock
, flags
);
1872 for (order
= 0; order
< MAX_ORDER
; order
++)
1873 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
1874 printk("= %lukB\n", K(total
));
1877 show_swap_cache_info();
1881 * Builds allocation fallback zone lists.
1883 * Add all populated zones of a node to the zonelist.
1885 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
1886 int nr_zones
, enum zone_type zone_type
)
1890 BUG_ON(zone_type
>= MAX_NR_ZONES
);
1895 zone
= pgdat
->node_zones
+ zone_type
;
1896 if (populated_zone(zone
)) {
1897 zonelist
->zones
[nr_zones
++] = zone
;
1898 check_highest_zone(zone_type
);
1901 } while (zone_type
);
1908 * 0 = automatic detection of better ordering.
1909 * 1 = order by ([node] distance, -zonetype)
1910 * 2 = order by (-zonetype, [node] distance)
1912 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
1913 * the same zonelist. So only NUMA can configure this param.
1915 #define ZONELIST_ORDER_DEFAULT 0
1916 #define ZONELIST_ORDER_NODE 1
1917 #define ZONELIST_ORDER_ZONE 2
1919 /* zonelist order in the kernel.
1920 * set_zonelist_order() will set this to NODE or ZONE.
1922 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
1923 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
1927 /* The value user specified ....changed by config */
1928 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
1929 /* string for sysctl */
1930 #define NUMA_ZONELIST_ORDER_LEN 16
1931 char numa_zonelist_order
[16] = "default";
1934 * interface for configure zonelist ordering.
1935 * command line option "numa_zonelist_order"
1936 * = "[dD]efault - default, automatic configuration.
1937 * = "[nN]ode - order by node locality, then by zone within node
1938 * = "[zZ]one - order by zone, then by locality within zone
1941 static int __parse_numa_zonelist_order(char *s
)
1943 if (*s
== 'd' || *s
== 'D') {
1944 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
1945 } else if (*s
== 'n' || *s
== 'N') {
1946 user_zonelist_order
= ZONELIST_ORDER_NODE
;
1947 } else if (*s
== 'z' || *s
== 'Z') {
1948 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
1951 "Ignoring invalid numa_zonelist_order value: "
1958 static __init
int setup_numa_zonelist_order(char *s
)
1961 return __parse_numa_zonelist_order(s
);
1964 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
1967 * sysctl handler for numa_zonelist_order
1969 int numa_zonelist_order_handler(ctl_table
*table
, int write
,
1970 struct file
*file
, void __user
*buffer
, size_t *length
,
1973 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
1977 strncpy(saved_string
, (char*)table
->data
,
1978 NUMA_ZONELIST_ORDER_LEN
);
1979 ret
= proc_dostring(table
, write
, file
, buffer
, length
, ppos
);
1983 int oldval
= user_zonelist_order
;
1984 if (__parse_numa_zonelist_order((char*)table
->data
)) {
1986 * bogus value. restore saved string
1988 strncpy((char*)table
->data
, saved_string
,
1989 NUMA_ZONELIST_ORDER_LEN
);
1990 user_zonelist_order
= oldval
;
1991 } else if (oldval
!= user_zonelist_order
)
1992 build_all_zonelists();
1998 #define MAX_NODE_LOAD (num_online_nodes())
1999 static int node_load
[MAX_NUMNODES
];
2002 * find_next_best_node - find the next node that should appear in a given node's fallback list
2003 * @node: node whose fallback list we're appending
2004 * @used_node_mask: nodemask_t of already used nodes
2006 * We use a number of factors to determine which is the next node that should
2007 * appear on a given node's fallback list. The node should not have appeared
2008 * already in @node's fallback list, and it should be the next closest node
2009 * according to the distance array (which contains arbitrary distance values
2010 * from each node to each node in the system), and should also prefer nodes
2011 * with no CPUs, since presumably they'll have very little allocation pressure
2012 * on them otherwise.
2013 * It returns -1 if no node is found.
2015 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
2018 int min_val
= INT_MAX
;
2021 /* Use the local node if we haven't already */
2022 if (!node_isset(node
, *used_node_mask
)) {
2023 node_set(node
, *used_node_mask
);
2027 for_each_node_state(n
, N_HIGH_MEMORY
) {
2030 /* Don't want a node to appear more than once */
2031 if (node_isset(n
, *used_node_mask
))
2034 /* Use the distance array to find the distance */
2035 val
= node_distance(node
, n
);
2037 /* Penalize nodes under us ("prefer the next node") */
2040 /* Give preference to headless and unused nodes */
2041 tmp
= node_to_cpumask(n
);
2042 if (!cpus_empty(tmp
))
2043 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
2045 /* Slight preference for less loaded node */
2046 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
2047 val
+= node_load
[n
];
2049 if (val
< min_val
) {
2056 node_set(best_node
, *used_node_mask
);
2063 * Build zonelists ordered by node and zones within node.
2064 * This results in maximum locality--normal zone overflows into local
2065 * DMA zone, if any--but risks exhausting DMA zone.
2067 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
2071 struct zonelist
*zonelist
;
2073 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
2074 zonelist
= pgdat
->node_zonelists
+ i
;
2075 for (j
= 0; zonelist
->zones
[j
] != NULL
; j
++)
2077 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
, i
);
2078 zonelist
->zones
[j
] = NULL
;
2083 * Build gfp_thisnode zonelists
2085 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
2089 struct zonelist
*zonelist
;
2091 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
2092 zonelist
= pgdat
->node_zonelists
+ MAX_NR_ZONES
+ i
;
2093 j
= build_zonelists_node(pgdat
, zonelist
, 0, i
);
2094 zonelist
->zones
[j
] = NULL
;
2099 * Build zonelists ordered by zone and nodes within zones.
2100 * This results in conserving DMA zone[s] until all Normal memory is
2101 * exhausted, but results in overflowing to remote node while memory
2102 * may still exist in local DMA zone.
2104 static int node_order
[MAX_NUMNODES
];
2106 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
2110 int zone_type
; /* needs to be signed */
2112 struct zonelist
*zonelist
;
2114 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
2115 zonelist
= pgdat
->node_zonelists
+ i
;
2117 for (zone_type
= i
; zone_type
>= 0; zone_type
--) {
2118 for (j
= 0; j
< nr_nodes
; j
++) {
2119 node
= node_order
[j
];
2120 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
2121 if (populated_zone(z
)) {
2122 zonelist
->zones
[pos
++] = z
;
2123 check_highest_zone(zone_type
);
2127 zonelist
->zones
[pos
] = NULL
;
2131 static int default_zonelist_order(void)
2134 unsigned long low_kmem_size
,total_size
;
2138 * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem.
2139 * If they are really small and used heavily, the system can fall
2140 * into OOM very easily.
2141 * This function detect ZONE_DMA/DMA32 size and confgigures zone order.
2143 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
2146 for_each_online_node(nid
) {
2147 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2148 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2149 if (populated_zone(z
)) {
2150 if (zone_type
< ZONE_NORMAL
)
2151 low_kmem_size
+= z
->present_pages
;
2152 total_size
+= z
->present_pages
;
2156 if (!low_kmem_size
|| /* there are no DMA area. */
2157 low_kmem_size
> total_size
/2) /* DMA/DMA32 is big. */
2158 return ZONELIST_ORDER_NODE
;
2160 * look into each node's config.
2161 * If there is a node whose DMA/DMA32 memory is very big area on
2162 * local memory, NODE_ORDER may be suitable.
2164 average_size
= total_size
/
2165 (nodes_weight(node_states
[N_HIGH_MEMORY
]) + 1);
2166 for_each_online_node(nid
) {
2169 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2170 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2171 if (populated_zone(z
)) {
2172 if (zone_type
< ZONE_NORMAL
)
2173 low_kmem_size
+= z
->present_pages
;
2174 total_size
+= z
->present_pages
;
2177 if (low_kmem_size
&&
2178 total_size
> average_size
&& /* ignore small node */
2179 low_kmem_size
> total_size
* 70/100)
2180 return ZONELIST_ORDER_NODE
;
2182 return ZONELIST_ORDER_ZONE
;
2185 static void set_zonelist_order(void)
2187 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
2188 current_zonelist_order
= default_zonelist_order();
2190 current_zonelist_order
= user_zonelist_order
;
2193 static void build_zonelists(pg_data_t
*pgdat
)
2197 nodemask_t used_mask
;
2198 int local_node
, prev_node
;
2199 struct zonelist
*zonelist
;
2200 int order
= current_zonelist_order
;
2202 /* initialize zonelists */
2203 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
2204 zonelist
= pgdat
->node_zonelists
+ i
;
2205 zonelist
->zones
[0] = NULL
;
2208 /* NUMA-aware ordering of nodes */
2209 local_node
= pgdat
->node_id
;
2210 load
= num_online_nodes();
2211 prev_node
= local_node
;
2212 nodes_clear(used_mask
);
2214 memset(node_load
, 0, sizeof(node_load
));
2215 memset(node_order
, 0, sizeof(node_order
));
2218 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
2219 int distance
= node_distance(local_node
, node
);
2222 * If another node is sufficiently far away then it is better
2223 * to reclaim pages in a zone before going off node.
2225 if (distance
> RECLAIM_DISTANCE
)
2226 zone_reclaim_mode
= 1;
2229 * We don't want to pressure a particular node.
2230 * So adding penalty to the first node in same
2231 * distance group to make it round-robin.
2233 if (distance
!= node_distance(local_node
, prev_node
))
2234 node_load
[node
] = load
;
2238 if (order
== ZONELIST_ORDER_NODE
)
2239 build_zonelists_in_node_order(pgdat
, node
);
2241 node_order
[j
++] = node
; /* remember order */
2244 if (order
== ZONELIST_ORDER_ZONE
) {
2245 /* calculate node order -- i.e., DMA last! */
2246 build_zonelists_in_zone_order(pgdat
, j
);
2249 build_thisnode_zonelists(pgdat
);
2252 /* Construct the zonelist performance cache - see further mmzone.h */
2253 static void build_zonelist_cache(pg_data_t
*pgdat
)
2257 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
2258 struct zonelist
*zonelist
;
2259 struct zonelist_cache
*zlc
;
2262 zonelist
= pgdat
->node_zonelists
+ i
;
2263 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
2264 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
2265 for (z
= zonelist
->zones
; *z
; z
++)
2266 zlc
->z_to_n
[z
- zonelist
->zones
] = zone_to_nid(*z
);
2271 #else /* CONFIG_NUMA */
2273 static void set_zonelist_order(void)
2275 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
2278 static void build_zonelists(pg_data_t
*pgdat
)
2280 int node
, local_node
;
2283 local_node
= pgdat
->node_id
;
2284 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
2285 struct zonelist
*zonelist
;
2287 zonelist
= pgdat
->node_zonelists
+ i
;
2289 j
= build_zonelists_node(pgdat
, zonelist
, 0, i
);
2291 * Now we build the zonelist so that it contains the zones
2292 * of all the other nodes.
2293 * We don't want to pressure a particular node, so when
2294 * building the zones for node N, we make sure that the
2295 * zones coming right after the local ones are those from
2296 * node N+1 (modulo N)
2298 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
2299 if (!node_online(node
))
2301 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
, i
);
2303 for (node
= 0; node
< local_node
; node
++) {
2304 if (!node_online(node
))
2306 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
, i
);
2309 zonelist
->zones
[j
] = NULL
;
2313 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2314 static void build_zonelist_cache(pg_data_t
*pgdat
)
2318 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
2319 pgdat
->node_zonelists
[i
].zlcache_ptr
= NULL
;
2322 #endif /* CONFIG_NUMA */
2324 /* return values int ....just for stop_machine_run() */
2325 static int __build_all_zonelists(void *dummy
)
2329 for_each_online_node(nid
) {
2330 pg_data_t
*pgdat
= NODE_DATA(nid
);
2332 build_zonelists(pgdat
);
2333 build_zonelist_cache(pgdat
);
2338 void build_all_zonelists(void)
2340 set_zonelist_order();
2342 if (system_state
== SYSTEM_BOOTING
) {
2343 __build_all_zonelists(NULL
);
2344 cpuset_init_current_mems_allowed();
2346 /* we have to stop all cpus to guarantee there is no user
2348 stop_machine_run(__build_all_zonelists
, NULL
, NR_CPUS
);
2349 /* cpuset refresh routine should be here */
2351 vm_total_pages
= nr_free_pagecache_pages();
2353 * Disable grouping by mobility if the number of pages in the
2354 * system is too low to allow the mechanism to work. It would be
2355 * more accurate, but expensive to check per-zone. This check is
2356 * made on memory-hotadd so a system can start with mobility
2357 * disabled and enable it later
2359 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
2360 page_group_by_mobility_disabled
= 1;
2362 page_group_by_mobility_disabled
= 0;
2364 printk("Built %i zonelists in %s order, mobility grouping %s. "
2365 "Total pages: %ld\n",
2367 zonelist_order_name
[current_zonelist_order
],
2368 page_group_by_mobility_disabled
? "off" : "on",
2371 printk("Policy zone: %s\n", zone_names
[policy_zone
]);
2376 * Helper functions to size the waitqueue hash table.
2377 * Essentially these want to choose hash table sizes sufficiently
2378 * large so that collisions trying to wait on pages are rare.
2379 * But in fact, the number of active page waitqueues on typical
2380 * systems is ridiculously low, less than 200. So this is even
2381 * conservative, even though it seems large.
2383 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
2384 * waitqueues, i.e. the size of the waitq table given the number of pages.
2386 #define PAGES_PER_WAITQUEUE 256
2388 #ifndef CONFIG_MEMORY_HOTPLUG
2389 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
2391 unsigned long size
= 1;
2393 pages
/= PAGES_PER_WAITQUEUE
;
2395 while (size
< pages
)
2399 * Once we have dozens or even hundreds of threads sleeping
2400 * on IO we've got bigger problems than wait queue collision.
2401 * Limit the size of the wait table to a reasonable size.
2403 size
= min(size
, 4096UL);
2405 return max(size
, 4UL);
2409 * A zone's size might be changed by hot-add, so it is not possible to determine
2410 * a suitable size for its wait_table. So we use the maximum size now.
2412 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
2414 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
2415 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
2416 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
2418 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
2419 * or more by the traditional way. (See above). It equals:
2421 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
2422 * ia64(16K page size) : = ( 8G + 4M)byte.
2423 * powerpc (64K page size) : = (32G +16M)byte.
2425 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
2432 * This is an integer logarithm so that shifts can be used later
2433 * to extract the more random high bits from the multiplicative
2434 * hash function before the remainder is taken.
2436 static inline unsigned long wait_table_bits(unsigned long size
)
2441 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
2444 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2445 * of blocks reserved is based on zone->pages_min. The memory within the
2446 * reserve will tend to store contiguous free pages. Setting min_free_kbytes
2447 * higher will lead to a bigger reserve which will get freed as contiguous
2448 * blocks as reclaim kicks in
2450 static void setup_zone_migrate_reserve(struct zone
*zone
)
2452 unsigned long start_pfn
, pfn
, end_pfn
;
2454 unsigned long reserve
, block_migratetype
;
2456 /* Get the start pfn, end pfn and the number of blocks to reserve */
2457 start_pfn
= zone
->zone_start_pfn
;
2458 end_pfn
= start_pfn
+ zone
->spanned_pages
;
2459 reserve
= roundup(zone
->pages_min
, pageblock_nr_pages
) >>
2462 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
2463 if (!pfn_valid(pfn
))
2465 page
= pfn_to_page(pfn
);
2467 /* Blocks with reserved pages will never free, skip them. */
2468 if (PageReserved(page
))
2471 block_migratetype
= get_pageblock_migratetype(page
);
2473 /* If this block is reserved, account for it */
2474 if (reserve
> 0 && block_migratetype
== MIGRATE_RESERVE
) {
2479 /* Suitable for reserving if this block is movable */
2480 if (reserve
> 0 && block_migratetype
== MIGRATE_MOVABLE
) {
2481 set_pageblock_migratetype(page
, MIGRATE_RESERVE
);
2482 move_freepages_block(zone
, page
, MIGRATE_RESERVE
);
2488 * If the reserve is met and this is a previous reserved block,
2491 if (block_migratetype
== MIGRATE_RESERVE
) {
2492 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
2493 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
2499 * Initially all pages are reserved - free ones are freed
2500 * up by free_all_bootmem() once the early boot process is
2501 * done. Non-atomic initialization, single-pass.
2503 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
2504 unsigned long start_pfn
, enum memmap_context context
)
2507 unsigned long end_pfn
= start_pfn
+ size
;
2510 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
2512 * There can be holes in boot-time mem_map[]s
2513 * handed to this function. They do not
2514 * exist on hotplugged memory.
2516 if (context
== MEMMAP_EARLY
) {
2517 if (!early_pfn_valid(pfn
))
2519 if (!early_pfn_in_nid(pfn
, nid
))
2522 page
= pfn_to_page(pfn
);
2523 set_page_links(page
, zone
, nid
, pfn
);
2524 init_page_count(page
);
2525 reset_page_mapcount(page
);
2526 SetPageReserved(page
);
2529 * Mark the block movable so that blocks are reserved for
2530 * movable at startup. This will force kernel allocations
2531 * to reserve their blocks rather than leaking throughout
2532 * the address space during boot when many long-lived
2533 * kernel allocations are made. Later some blocks near
2534 * the start are marked MIGRATE_RESERVE by
2535 * setup_zone_migrate_reserve()
2537 if ((pfn
& (pageblock_nr_pages
-1)))
2538 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
2540 INIT_LIST_HEAD(&page
->lru
);
2541 #ifdef WANT_PAGE_VIRTUAL
2542 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
2543 if (!is_highmem_idx(zone
))
2544 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
2549 static void __meminit
zone_init_free_lists(struct pglist_data
*pgdat
,
2550 struct zone
*zone
, unsigned long size
)
2553 for_each_migratetype_order(order
, t
) {
2554 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
2555 zone
->free_area
[order
].nr_free
= 0;
2559 #ifndef __HAVE_ARCH_MEMMAP_INIT
2560 #define memmap_init(size, nid, zone, start_pfn) \
2561 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
2564 static int zone_batchsize(struct zone
*zone
)
2569 * The per-cpu-pages pools are set to around 1000th of the
2570 * size of the zone. But no more than 1/2 of a meg.
2572 * OK, so we don't know how big the cache is. So guess.
2574 batch
= zone
->present_pages
/ 1024;
2575 if (batch
* PAGE_SIZE
> 512 * 1024)
2576 batch
= (512 * 1024) / PAGE_SIZE
;
2577 batch
/= 4; /* We effectively *= 4 below */
2582 * Clamp the batch to a 2^n - 1 value. Having a power
2583 * of 2 value was found to be more likely to have
2584 * suboptimal cache aliasing properties in some cases.
2586 * For example if 2 tasks are alternately allocating
2587 * batches of pages, one task can end up with a lot
2588 * of pages of one half of the possible page colors
2589 * and the other with pages of the other colors.
2591 batch
= (1 << (fls(batch
+ batch
/2)-1)) - 1;
2596 inline void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
2598 struct per_cpu_pages
*pcp
;
2600 memset(p
, 0, sizeof(*p
));
2604 pcp
->high
= 6 * batch
;
2605 pcp
->batch
= max(1UL, 1 * batch
);
2606 INIT_LIST_HEAD(&pcp
->list
);
2610 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
2611 * to the value high for the pageset p.
2614 static void setup_pagelist_highmark(struct per_cpu_pageset
*p
,
2617 struct per_cpu_pages
*pcp
;
2621 pcp
->batch
= max(1UL, high
/4);
2622 if ((high
/4) > (PAGE_SHIFT
* 8))
2623 pcp
->batch
= PAGE_SHIFT
* 8;
2629 * Boot pageset table. One per cpu which is going to be used for all
2630 * zones and all nodes. The parameters will be set in such a way
2631 * that an item put on a list will immediately be handed over to
2632 * the buddy list. This is safe since pageset manipulation is done
2633 * with interrupts disabled.
2635 * Some NUMA counter updates may also be caught by the boot pagesets.
2637 * The boot_pagesets must be kept even after bootup is complete for
2638 * unused processors and/or zones. They do play a role for bootstrapping
2639 * hotplugged processors.
2641 * zoneinfo_show() and maybe other functions do
2642 * not check if the processor is online before following the pageset pointer.
2643 * Other parts of the kernel may not check if the zone is available.
2645 static struct per_cpu_pageset boot_pageset
[NR_CPUS
];
2648 * Dynamically allocate memory for the
2649 * per cpu pageset array in struct zone.
2651 static int __cpuinit
process_zones(int cpu
)
2653 struct zone
*zone
, *dzone
;
2654 int node
= cpu_to_node(cpu
);
2656 node_set_state(node
, N_CPU
); /* this node has a cpu */
2658 for_each_zone(zone
) {
2660 if (!populated_zone(zone
))
2663 zone_pcp(zone
, cpu
) = kmalloc_node(sizeof(struct per_cpu_pageset
),
2665 if (!zone_pcp(zone
, cpu
))
2668 setup_pageset(zone_pcp(zone
, cpu
), zone_batchsize(zone
));
2670 if (percpu_pagelist_fraction
)
2671 setup_pagelist_highmark(zone_pcp(zone
, cpu
),
2672 (zone
->present_pages
/ percpu_pagelist_fraction
));
2677 for_each_zone(dzone
) {
2678 if (!populated_zone(dzone
))
2682 kfree(zone_pcp(dzone
, cpu
));
2683 zone_pcp(dzone
, cpu
) = NULL
;
2688 static inline void free_zone_pagesets(int cpu
)
2692 for_each_zone(zone
) {
2693 struct per_cpu_pageset
*pset
= zone_pcp(zone
, cpu
);
2695 /* Free per_cpu_pageset if it is slab allocated */
2696 if (pset
!= &boot_pageset
[cpu
])
2698 zone_pcp(zone
, cpu
) = NULL
;
2702 static int __cpuinit
pageset_cpuup_callback(struct notifier_block
*nfb
,
2703 unsigned long action
,
2706 int cpu
= (long)hcpu
;
2707 int ret
= NOTIFY_OK
;
2710 case CPU_UP_PREPARE
:
2711 case CPU_UP_PREPARE_FROZEN
:
2712 if (process_zones(cpu
))
2715 case CPU_UP_CANCELED
:
2716 case CPU_UP_CANCELED_FROZEN
:
2718 case CPU_DEAD_FROZEN
:
2719 free_zone_pagesets(cpu
);
2727 static struct notifier_block __cpuinitdata pageset_notifier
=
2728 { &pageset_cpuup_callback
, NULL
, 0 };
2730 void __init
setup_per_cpu_pageset(void)
2734 /* Initialize per_cpu_pageset for cpu 0.
2735 * A cpuup callback will do this for every cpu
2736 * as it comes online
2738 err
= process_zones(smp_processor_id());
2740 register_cpu_notifier(&pageset_notifier
);
2745 static noinline __init_refok
2746 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
2749 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
2753 * The per-page waitqueue mechanism uses hashed waitqueues
2756 zone
->wait_table_hash_nr_entries
=
2757 wait_table_hash_nr_entries(zone_size_pages
);
2758 zone
->wait_table_bits
=
2759 wait_table_bits(zone
->wait_table_hash_nr_entries
);
2760 alloc_size
= zone
->wait_table_hash_nr_entries
2761 * sizeof(wait_queue_head_t
);
2763 if (system_state
== SYSTEM_BOOTING
) {
2764 zone
->wait_table
= (wait_queue_head_t
*)
2765 alloc_bootmem_node(pgdat
, alloc_size
);
2768 * This case means that a zone whose size was 0 gets new memory
2769 * via memory hot-add.
2770 * But it may be the case that a new node was hot-added. In
2771 * this case vmalloc() will not be able to use this new node's
2772 * memory - this wait_table must be initialized to use this new
2773 * node itself as well.
2774 * To use this new node's memory, further consideration will be
2777 zone
->wait_table
= vmalloc(alloc_size
);
2779 if (!zone
->wait_table
)
2782 for(i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
2783 init_waitqueue_head(zone
->wait_table
+ i
);
2788 static __meminit
void zone_pcp_init(struct zone
*zone
)
2791 unsigned long batch
= zone_batchsize(zone
);
2793 for (cpu
= 0; cpu
< NR_CPUS
; cpu
++) {
2795 /* Early boot. Slab allocator not functional yet */
2796 zone_pcp(zone
, cpu
) = &boot_pageset
[cpu
];
2797 setup_pageset(&boot_pageset
[cpu
],0);
2799 setup_pageset(zone_pcp(zone
,cpu
), batch
);
2802 if (zone
->present_pages
)
2803 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%lu\n",
2804 zone
->name
, zone
->present_pages
, batch
);
2807 __meminit
int init_currently_empty_zone(struct zone
*zone
,
2808 unsigned long zone_start_pfn
,
2810 enum memmap_context context
)
2812 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
2814 ret
= zone_wait_table_init(zone
, size
);
2817 pgdat
->nr_zones
= zone_idx(zone
) + 1;
2819 zone
->zone_start_pfn
= zone_start_pfn
;
2821 memmap_init(size
, pgdat
->node_id
, zone_idx(zone
), zone_start_pfn
);
2823 zone_init_free_lists(pgdat
, zone
, zone
->spanned_pages
);
2828 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
2830 * Basic iterator support. Return the first range of PFNs for a node
2831 * Note: nid == MAX_NUMNODES returns first region regardless of node
2833 static int __meminit
first_active_region_index_in_nid(int nid
)
2837 for (i
= 0; i
< nr_nodemap_entries
; i
++)
2838 if (nid
== MAX_NUMNODES
|| early_node_map
[i
].nid
== nid
)
2845 * Basic iterator support. Return the next active range of PFNs for a node
2846 * Note: nid == MAX_NUMNODES returns next region regardless of node
2848 static int __meminit
next_active_region_index_in_nid(int index
, int nid
)
2850 for (index
= index
+ 1; index
< nr_nodemap_entries
; index
++)
2851 if (nid
== MAX_NUMNODES
|| early_node_map
[index
].nid
== nid
)
2857 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
2859 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
2860 * Architectures may implement their own version but if add_active_range()
2861 * was used and there are no special requirements, this is a convenient
2864 int __meminit
early_pfn_to_nid(unsigned long pfn
)
2868 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
2869 unsigned long start_pfn
= early_node_map
[i
].start_pfn
;
2870 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
2872 if (start_pfn
<= pfn
&& pfn
< end_pfn
)
2873 return early_node_map
[i
].nid
;
2878 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
2880 /* Basic iterator support to walk early_node_map[] */
2881 #define for_each_active_range_index_in_nid(i, nid) \
2882 for (i = first_active_region_index_in_nid(nid); i != -1; \
2883 i = next_active_region_index_in_nid(i, nid))
2886 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
2887 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
2888 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
2890 * If an architecture guarantees that all ranges registered with
2891 * add_active_ranges() contain no holes and may be freed, this
2892 * this function may be used instead of calling free_bootmem() manually.
2894 void __init
free_bootmem_with_active_regions(int nid
,
2895 unsigned long max_low_pfn
)
2899 for_each_active_range_index_in_nid(i
, nid
) {
2900 unsigned long size_pages
= 0;
2901 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
2903 if (early_node_map
[i
].start_pfn
>= max_low_pfn
)
2906 if (end_pfn
> max_low_pfn
)
2907 end_pfn
= max_low_pfn
;
2909 size_pages
= end_pfn
- early_node_map
[i
].start_pfn
;
2910 free_bootmem_node(NODE_DATA(early_node_map
[i
].nid
),
2911 PFN_PHYS(early_node_map
[i
].start_pfn
),
2912 size_pages
<< PAGE_SHIFT
);
2917 * sparse_memory_present_with_active_regions - Call memory_present for each active range
2918 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
2920 * If an architecture guarantees that all ranges registered with
2921 * add_active_ranges() contain no holes and may be freed, this
2922 * function may be used instead of calling memory_present() manually.
2924 void __init
sparse_memory_present_with_active_regions(int nid
)
2928 for_each_active_range_index_in_nid(i
, nid
)
2929 memory_present(early_node_map
[i
].nid
,
2930 early_node_map
[i
].start_pfn
,
2931 early_node_map
[i
].end_pfn
);
2935 * push_node_boundaries - Push node boundaries to at least the requested boundary
2936 * @nid: The nid of the node to push the boundary for
2937 * @start_pfn: The start pfn of the node
2938 * @end_pfn: The end pfn of the node
2940 * In reserve-based hot-add, mem_map is allocated that is unused until hotadd
2941 * time. Specifically, on x86_64, SRAT will report ranges that can potentially
2942 * be hotplugged even though no physical memory exists. This function allows
2943 * an arch to push out the node boundaries so mem_map is allocated that can
2946 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
2947 void __init
push_node_boundaries(unsigned int nid
,
2948 unsigned long start_pfn
, unsigned long end_pfn
)
2950 printk(KERN_DEBUG
"Entering push_node_boundaries(%u, %lu, %lu)\n",
2951 nid
, start_pfn
, end_pfn
);
2953 /* Initialise the boundary for this node if necessary */
2954 if (node_boundary_end_pfn
[nid
] == 0)
2955 node_boundary_start_pfn
[nid
] = -1UL;
2957 /* Update the boundaries */
2958 if (node_boundary_start_pfn
[nid
] > start_pfn
)
2959 node_boundary_start_pfn
[nid
] = start_pfn
;
2960 if (node_boundary_end_pfn
[nid
] < end_pfn
)
2961 node_boundary_end_pfn
[nid
] = end_pfn
;
2964 /* If necessary, push the node boundary out for reserve hotadd */
2965 static void __meminit
account_node_boundary(unsigned int nid
,
2966 unsigned long *start_pfn
, unsigned long *end_pfn
)
2968 printk(KERN_DEBUG
"Entering account_node_boundary(%u, %lu, %lu)\n",
2969 nid
, *start_pfn
, *end_pfn
);
2971 /* Return if boundary information has not been provided */
2972 if (node_boundary_end_pfn
[nid
] == 0)
2975 /* Check the boundaries and update if necessary */
2976 if (node_boundary_start_pfn
[nid
] < *start_pfn
)
2977 *start_pfn
= node_boundary_start_pfn
[nid
];
2978 if (node_boundary_end_pfn
[nid
] > *end_pfn
)
2979 *end_pfn
= node_boundary_end_pfn
[nid
];
2982 void __init
push_node_boundaries(unsigned int nid
,
2983 unsigned long start_pfn
, unsigned long end_pfn
) {}
2985 static void __meminit
account_node_boundary(unsigned int nid
,
2986 unsigned long *start_pfn
, unsigned long *end_pfn
) {}
2991 * get_pfn_range_for_nid - Return the start and end page frames for a node
2992 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
2993 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
2994 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
2996 * It returns the start and end page frame of a node based on information
2997 * provided by an arch calling add_active_range(). If called for a node
2998 * with no available memory, a warning is printed and the start and end
3001 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
3002 unsigned long *start_pfn
, unsigned long *end_pfn
)
3008 for_each_active_range_index_in_nid(i
, nid
) {
3009 *start_pfn
= min(*start_pfn
, early_node_map
[i
].start_pfn
);
3010 *end_pfn
= max(*end_pfn
, early_node_map
[i
].end_pfn
);
3013 if (*start_pfn
== -1UL)
3016 /* Push the node boundaries out if requested */
3017 account_node_boundary(nid
, start_pfn
, end_pfn
);
3021 * This finds a zone that can be used for ZONE_MOVABLE pages. The
3022 * assumption is made that zones within a node are ordered in monotonic
3023 * increasing memory addresses so that the "highest" populated zone is used
3025 void __init
find_usable_zone_for_movable(void)
3028 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
3029 if (zone_index
== ZONE_MOVABLE
)
3032 if (arch_zone_highest_possible_pfn
[zone_index
] >
3033 arch_zone_lowest_possible_pfn
[zone_index
])
3037 VM_BUG_ON(zone_index
== -1);
3038 movable_zone
= zone_index
;
3042 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
3043 * because it is sized independant of architecture. Unlike the other zones,
3044 * the starting point for ZONE_MOVABLE is not fixed. It may be different
3045 * in each node depending on the size of each node and how evenly kernelcore
3046 * is distributed. This helper function adjusts the zone ranges
3047 * provided by the architecture for a given node by using the end of the
3048 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
3049 * zones within a node are in order of monotonic increases memory addresses
3051 void __meminit
adjust_zone_range_for_zone_movable(int nid
,
3052 unsigned long zone_type
,
3053 unsigned long node_start_pfn
,
3054 unsigned long node_end_pfn
,
3055 unsigned long *zone_start_pfn
,
3056 unsigned long *zone_end_pfn
)
3058 /* Only adjust if ZONE_MOVABLE is on this node */
3059 if (zone_movable_pfn
[nid
]) {
3060 /* Size ZONE_MOVABLE */
3061 if (zone_type
== ZONE_MOVABLE
) {
3062 *zone_start_pfn
= zone_movable_pfn
[nid
];
3063 *zone_end_pfn
= min(node_end_pfn
,
3064 arch_zone_highest_possible_pfn
[movable_zone
]);
3066 /* Adjust for ZONE_MOVABLE starting within this range */
3067 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
3068 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
3069 *zone_end_pfn
= zone_movable_pfn
[nid
];
3071 /* Check if this whole range is within ZONE_MOVABLE */
3072 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
3073 *zone_start_pfn
= *zone_end_pfn
;
3078 * Return the number of pages a zone spans in a node, including holes
3079 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
3081 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3082 unsigned long zone_type
,
3083 unsigned long *ignored
)
3085 unsigned long node_start_pfn
, node_end_pfn
;
3086 unsigned long zone_start_pfn
, zone_end_pfn
;
3088 /* Get the start and end of the node and zone */
3089 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3090 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
3091 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
3092 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3093 node_start_pfn
, node_end_pfn
,
3094 &zone_start_pfn
, &zone_end_pfn
);
3096 /* Check that this node has pages within the zone's required range */
3097 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
3100 /* Move the zone boundaries inside the node if necessary */
3101 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
3102 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
3104 /* Return the spanned pages */
3105 return zone_end_pfn
- zone_start_pfn
;
3109 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
3110 * then all holes in the requested range will be accounted for.
3112 unsigned long __meminit
__absent_pages_in_range(int nid
,
3113 unsigned long range_start_pfn
,
3114 unsigned long range_end_pfn
)
3117 unsigned long prev_end_pfn
= 0, hole_pages
= 0;
3118 unsigned long start_pfn
;
3120 /* Find the end_pfn of the first active range of pfns in the node */
3121 i
= first_active_region_index_in_nid(nid
);
3125 prev_end_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3127 /* Account for ranges before physical memory on this node */
3128 if (early_node_map
[i
].start_pfn
> range_start_pfn
)
3129 hole_pages
= prev_end_pfn
- range_start_pfn
;
3131 /* Find all holes for the zone within the node */
3132 for (; i
!= -1; i
= next_active_region_index_in_nid(i
, nid
)) {
3134 /* No need to continue if prev_end_pfn is outside the zone */
3135 if (prev_end_pfn
>= range_end_pfn
)
3138 /* Make sure the end of the zone is not within the hole */
3139 start_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3140 prev_end_pfn
= max(prev_end_pfn
, range_start_pfn
);
3142 /* Update the hole size cound and move on */
3143 if (start_pfn
> range_start_pfn
) {
3144 BUG_ON(prev_end_pfn
> start_pfn
);
3145 hole_pages
+= start_pfn
- prev_end_pfn
;
3147 prev_end_pfn
= early_node_map
[i
].end_pfn
;
3150 /* Account for ranges past physical memory on this node */
3151 if (range_end_pfn
> prev_end_pfn
)
3152 hole_pages
+= range_end_pfn
-
3153 max(range_start_pfn
, prev_end_pfn
);
3159 * absent_pages_in_range - Return number of page frames in holes within a range
3160 * @start_pfn: The start PFN to start searching for holes
3161 * @end_pfn: The end PFN to stop searching for holes
3163 * It returns the number of pages frames in memory holes within a range.
3165 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
3166 unsigned long end_pfn
)
3168 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
3171 /* Return the number of page frames in holes in a zone on a node */
3172 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
3173 unsigned long zone_type
,
3174 unsigned long *ignored
)
3176 unsigned long node_start_pfn
, node_end_pfn
;
3177 unsigned long zone_start_pfn
, zone_end_pfn
;
3179 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3180 zone_start_pfn
= max(arch_zone_lowest_possible_pfn
[zone_type
],
3182 zone_end_pfn
= min(arch_zone_highest_possible_pfn
[zone_type
],
3185 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3186 node_start_pfn
, node_end_pfn
,
3187 &zone_start_pfn
, &zone_end_pfn
);
3188 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
3192 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3193 unsigned long zone_type
,
3194 unsigned long *zones_size
)
3196 return zones_size
[zone_type
];
3199 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
3200 unsigned long zone_type
,
3201 unsigned long *zholes_size
)
3206 return zholes_size
[zone_type
];
3211 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
3212 unsigned long *zones_size
, unsigned long *zholes_size
)
3214 unsigned long realtotalpages
, totalpages
= 0;
3217 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3218 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
3220 pgdat
->node_spanned_pages
= totalpages
;
3222 realtotalpages
= totalpages
;
3223 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3225 zone_absent_pages_in_node(pgdat
->node_id
, i
,
3227 pgdat
->node_present_pages
= realtotalpages
;
3228 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
3232 #ifndef CONFIG_SPARSEMEM
3234 * Calculate the size of the zone->blockflags rounded to an unsigned long
3235 * Start by making sure zonesize is a multiple of pageblock_order by rounding
3236 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
3237 * round what is now in bits to nearest long in bits, then return it in
3240 static unsigned long __init
usemap_size(unsigned long zonesize
)
3242 unsigned long usemapsize
;
3244 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
3245 usemapsize
= usemapsize
>> pageblock_order
;
3246 usemapsize
*= NR_PAGEBLOCK_BITS
;
3247 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
3249 return usemapsize
/ 8;
3252 static void __init
setup_usemap(struct pglist_data
*pgdat
,
3253 struct zone
*zone
, unsigned long zonesize
)
3255 unsigned long usemapsize
= usemap_size(zonesize
);
3256 zone
->pageblock_flags
= NULL
;
3258 zone
->pageblock_flags
= alloc_bootmem_node(pgdat
, usemapsize
);
3259 memset(zone
->pageblock_flags
, 0, usemapsize
);
3263 static void inline setup_usemap(struct pglist_data
*pgdat
,
3264 struct zone
*zone
, unsigned long zonesize
) {}
3265 #endif /* CONFIG_SPARSEMEM */
3267 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3269 /* Return a sensible default order for the pageblock size. */
3270 static inline int pageblock_default_order(void)
3272 if (HPAGE_SHIFT
> PAGE_SHIFT
)
3273 return HUGETLB_PAGE_ORDER
;
3278 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
3279 static inline void __init
set_pageblock_order(unsigned int order
)
3281 /* Check that pageblock_nr_pages has not already been setup */
3282 if (pageblock_order
)
3286 * Assume the largest contiguous order of interest is a huge page.
3287 * This value may be variable depending on boot parameters on IA64
3289 pageblock_order
= order
;
3291 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3294 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
3295 * and pageblock_default_order() are unused as pageblock_order is set
3296 * at compile-time. See include/linux/pageblock-flags.h for the values of
3297 * pageblock_order based on the kernel config
3299 static inline int pageblock_default_order(unsigned int order
)
3303 #define set_pageblock_order(x) do {} while (0)
3305 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3308 * Set up the zone data structures:
3309 * - mark all pages reserved
3310 * - mark all memory queues empty
3311 * - clear the memory bitmaps
3313 static void __meminit
free_area_init_core(struct pglist_data
*pgdat
,
3314 unsigned long *zones_size
, unsigned long *zholes_size
)
3317 int nid
= pgdat
->node_id
;
3318 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
3321 pgdat_resize_init(pgdat
);
3322 pgdat
->nr_zones
= 0;
3323 init_waitqueue_head(&pgdat
->kswapd_wait
);
3324 pgdat
->kswapd_max_order
= 0;
3326 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
3327 struct zone
*zone
= pgdat
->node_zones
+ j
;
3328 unsigned long size
, realsize
, memmap_pages
;
3330 size
= zone_spanned_pages_in_node(nid
, j
, zones_size
);
3331 realsize
= size
- zone_absent_pages_in_node(nid
, j
,
3335 * Adjust realsize so that it accounts for how much memory
3336 * is used by this zone for memmap. This affects the watermark
3337 * and per-cpu initialisations
3339 memmap_pages
= (size
* sizeof(struct page
)) >> PAGE_SHIFT
;
3340 if (realsize
>= memmap_pages
) {
3341 realsize
-= memmap_pages
;
3343 " %s zone: %lu pages used for memmap\n",
3344 zone_names
[j
], memmap_pages
);
3347 " %s zone: %lu pages exceeds realsize %lu\n",
3348 zone_names
[j
], memmap_pages
, realsize
);
3350 /* Account for reserved pages */
3351 if (j
== 0 && realsize
> dma_reserve
) {
3352 realsize
-= dma_reserve
;
3353 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
3354 zone_names
[0], dma_reserve
);
3357 if (!is_highmem_idx(j
))
3358 nr_kernel_pages
+= realsize
;
3359 nr_all_pages
+= realsize
;
3361 zone
->spanned_pages
= size
;
3362 zone
->present_pages
= realsize
;
3365 zone
->min_unmapped_pages
= (realsize
*sysctl_min_unmapped_ratio
)
3367 zone
->min_slab_pages
= (realsize
* sysctl_min_slab_ratio
) / 100;
3369 zone
->name
= zone_names
[j
];
3370 spin_lock_init(&zone
->lock
);
3371 spin_lock_init(&zone
->lru_lock
);
3372 zone_seqlock_init(zone
);
3373 zone
->zone_pgdat
= pgdat
;
3375 zone
->prev_priority
= DEF_PRIORITY
;
3377 zone_pcp_init(zone
);
3378 INIT_LIST_HEAD(&zone
->active_list
);
3379 INIT_LIST_HEAD(&zone
->inactive_list
);
3380 zone
->nr_scan_active
= 0;
3381 zone
->nr_scan_inactive
= 0;
3382 zap_zone_vm_stats(zone
);
3387 set_pageblock_order(pageblock_default_order());
3388 setup_usemap(pgdat
, zone
, size
);
3389 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
3390 size
, MEMMAP_EARLY
);
3392 zone_start_pfn
+= size
;
3396 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
3398 /* Skip empty nodes */
3399 if (!pgdat
->node_spanned_pages
)
3402 #ifdef CONFIG_FLAT_NODE_MEM_MAP
3403 /* ia64 gets its own node_mem_map, before this, without bootmem */
3404 if (!pgdat
->node_mem_map
) {
3405 unsigned long size
, start
, end
;
3409 * The zone's endpoints aren't required to be MAX_ORDER
3410 * aligned but the node_mem_map endpoints must be in order
3411 * for the buddy allocator to function correctly.
3413 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
3414 end
= pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
3415 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
3416 size
= (end
- start
) * sizeof(struct page
);
3417 map
= alloc_remap(pgdat
->node_id
, size
);
3419 map
= alloc_bootmem_node(pgdat
, size
);
3420 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
3422 #ifndef CONFIG_NEED_MULTIPLE_NODES
3424 * With no DISCONTIG, the global mem_map is just set as node 0's
3426 if (pgdat
== NODE_DATA(0)) {
3427 mem_map
= NODE_DATA(0)->node_mem_map
;
3428 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3429 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
3430 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
3431 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
3434 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
3437 void __meminit
free_area_init_node(int nid
, struct pglist_data
*pgdat
,
3438 unsigned long *zones_size
, unsigned long node_start_pfn
,
3439 unsigned long *zholes_size
)
3441 pgdat
->node_id
= nid
;
3442 pgdat
->node_start_pfn
= node_start_pfn
;
3443 calculate_node_totalpages(pgdat
, zones_size
, zholes_size
);
3445 alloc_node_mem_map(pgdat
);
3447 free_area_init_core(pgdat
, zones_size
, zholes_size
);
3450 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3452 #if MAX_NUMNODES > 1
3454 * Figure out the number of possible node ids.
3456 static void __init
setup_nr_node_ids(void)
3459 unsigned int highest
= 0;
3461 for_each_node_mask(node
, node_possible_map
)
3463 nr_node_ids
= highest
+ 1;
3466 static inline void setup_nr_node_ids(void)
3472 * add_active_range - Register a range of PFNs backed by physical memory
3473 * @nid: The node ID the range resides on
3474 * @start_pfn: The start PFN of the available physical memory
3475 * @end_pfn: The end PFN of the available physical memory
3477 * These ranges are stored in an early_node_map[] and later used by
3478 * free_area_init_nodes() to calculate zone sizes and holes. If the
3479 * range spans a memory hole, it is up to the architecture to ensure
3480 * the memory is not freed by the bootmem allocator. If possible
3481 * the range being registered will be merged with existing ranges.
3483 void __init
add_active_range(unsigned int nid
, unsigned long start_pfn
,
3484 unsigned long end_pfn
)
3488 printk(KERN_DEBUG
"Entering add_active_range(%d, %lu, %lu) "
3489 "%d entries of %d used\n",
3490 nid
, start_pfn
, end_pfn
,
3491 nr_nodemap_entries
, MAX_ACTIVE_REGIONS
);
3493 /* Merge with existing active regions if possible */
3494 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
3495 if (early_node_map
[i
].nid
!= nid
)
3498 /* Skip if an existing region covers this new one */
3499 if (start_pfn
>= early_node_map
[i
].start_pfn
&&
3500 end_pfn
<= early_node_map
[i
].end_pfn
)
3503 /* Merge forward if suitable */
3504 if (start_pfn
<= early_node_map
[i
].end_pfn
&&
3505 end_pfn
> early_node_map
[i
].end_pfn
) {
3506 early_node_map
[i
].end_pfn
= end_pfn
;
3510 /* Merge backward if suitable */
3511 if (start_pfn
< early_node_map
[i
].end_pfn
&&
3512 end_pfn
>= early_node_map
[i
].start_pfn
) {
3513 early_node_map
[i
].start_pfn
= start_pfn
;
3518 /* Check that early_node_map is large enough */
3519 if (i
>= MAX_ACTIVE_REGIONS
) {
3520 printk(KERN_CRIT
"More than %d memory regions, truncating\n",
3521 MAX_ACTIVE_REGIONS
);
3525 early_node_map
[i
].nid
= nid
;
3526 early_node_map
[i
].start_pfn
= start_pfn
;
3527 early_node_map
[i
].end_pfn
= end_pfn
;
3528 nr_nodemap_entries
= i
+ 1;
3532 * shrink_active_range - Shrink an existing registered range of PFNs
3533 * @nid: The node id the range is on that should be shrunk
3534 * @old_end_pfn: The old end PFN of the range
3535 * @new_end_pfn: The new PFN of the range
3537 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
3538 * The map is kept at the end physical page range that has already been
3539 * registered with add_active_range(). This function allows an arch to shrink
3540 * an existing registered range.
3542 void __init
shrink_active_range(unsigned int nid
, unsigned long old_end_pfn
,
3543 unsigned long new_end_pfn
)
3547 /* Find the old active region end and shrink */
3548 for_each_active_range_index_in_nid(i
, nid
)
3549 if (early_node_map
[i
].end_pfn
== old_end_pfn
) {
3550 early_node_map
[i
].end_pfn
= new_end_pfn
;
3556 * remove_all_active_ranges - Remove all currently registered regions
3558 * During discovery, it may be found that a table like SRAT is invalid
3559 * and an alternative discovery method must be used. This function removes
3560 * all currently registered regions.
3562 void __init
remove_all_active_ranges(void)
3564 memset(early_node_map
, 0, sizeof(early_node_map
));
3565 nr_nodemap_entries
= 0;
3566 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
3567 memset(node_boundary_start_pfn
, 0, sizeof(node_boundary_start_pfn
));
3568 memset(node_boundary_end_pfn
, 0, sizeof(node_boundary_end_pfn
));
3569 #endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
3572 /* Compare two active node_active_regions */
3573 static int __init
cmp_node_active_region(const void *a
, const void *b
)
3575 struct node_active_region
*arange
= (struct node_active_region
*)a
;
3576 struct node_active_region
*brange
= (struct node_active_region
*)b
;
3578 /* Done this way to avoid overflows */
3579 if (arange
->start_pfn
> brange
->start_pfn
)
3581 if (arange
->start_pfn
< brange
->start_pfn
)
3587 /* sort the node_map by start_pfn */
3588 static void __init
sort_node_map(void)
3590 sort(early_node_map
, (size_t)nr_nodemap_entries
,
3591 sizeof(struct node_active_region
),
3592 cmp_node_active_region
, NULL
);
3595 /* Find the lowest pfn for a node */
3596 unsigned long __init
find_min_pfn_for_node(unsigned long nid
)
3599 unsigned long min_pfn
= ULONG_MAX
;
3601 /* Assuming a sorted map, the first range found has the starting pfn */
3602 for_each_active_range_index_in_nid(i
, nid
)
3603 min_pfn
= min(min_pfn
, early_node_map
[i
].start_pfn
);
3605 if (min_pfn
== ULONG_MAX
) {
3607 "Could not find start_pfn for node %lu\n", nid
);
3615 * find_min_pfn_with_active_regions - Find the minimum PFN registered
3617 * It returns the minimum PFN based on information provided via
3618 * add_active_range().
3620 unsigned long __init
find_min_pfn_with_active_regions(void)
3622 return find_min_pfn_for_node(MAX_NUMNODES
);
3626 * find_max_pfn_with_active_regions - Find the maximum PFN registered
3628 * It returns the maximum PFN based on information provided via
3629 * add_active_range().
3631 unsigned long __init
find_max_pfn_with_active_regions(void)
3634 unsigned long max_pfn
= 0;
3636 for (i
= 0; i
< nr_nodemap_entries
; i
++)
3637 max_pfn
= max(max_pfn
, early_node_map
[i
].end_pfn
);
3643 * early_calculate_totalpages()
3644 * Sum pages in active regions for movable zone.
3645 * Populate N_HIGH_MEMORY for calculating usable_nodes.
3647 static unsigned long __init
early_calculate_totalpages(void)
3650 unsigned long totalpages
= 0;
3652 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
3653 unsigned long pages
= early_node_map
[i
].end_pfn
-
3654 early_node_map
[i
].start_pfn
;
3655 totalpages
+= pages
;
3657 node_set_state(early_node_map
[i
].nid
, N_HIGH_MEMORY
);
3663 * Find the PFN the Movable zone begins in each node. Kernel memory
3664 * is spread evenly between nodes as long as the nodes have enough
3665 * memory. When they don't, some nodes will have more kernelcore than
3668 void __init
find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn
)
3671 unsigned long usable_startpfn
;
3672 unsigned long kernelcore_node
, kernelcore_remaining
;
3673 unsigned long totalpages
= early_calculate_totalpages();
3674 int usable_nodes
= nodes_weight(node_states
[N_HIGH_MEMORY
]);
3677 * If movablecore was specified, calculate what size of
3678 * kernelcore that corresponds so that memory usable for
3679 * any allocation type is evenly spread. If both kernelcore
3680 * and movablecore are specified, then the value of kernelcore
3681 * will be used for required_kernelcore if it's greater than
3682 * what movablecore would have allowed.
3684 if (required_movablecore
) {
3685 unsigned long corepages
;
3688 * Round-up so that ZONE_MOVABLE is at least as large as what
3689 * was requested by the user
3691 required_movablecore
=
3692 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
3693 corepages
= totalpages
- required_movablecore
;
3695 required_kernelcore
= max(required_kernelcore
, corepages
);
3698 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
3699 if (!required_kernelcore
)
3702 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
3703 find_usable_zone_for_movable();
3704 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
3707 /* Spread kernelcore memory as evenly as possible throughout nodes */
3708 kernelcore_node
= required_kernelcore
/ usable_nodes
;
3709 for_each_node_state(nid
, N_HIGH_MEMORY
) {
3711 * Recalculate kernelcore_node if the division per node
3712 * now exceeds what is necessary to satisfy the requested
3713 * amount of memory for the kernel
3715 if (required_kernelcore
< kernelcore_node
)
3716 kernelcore_node
= required_kernelcore
/ usable_nodes
;
3719 * As the map is walked, we track how much memory is usable
3720 * by the kernel using kernelcore_remaining. When it is
3721 * 0, the rest of the node is usable by ZONE_MOVABLE
3723 kernelcore_remaining
= kernelcore_node
;
3725 /* Go through each range of PFNs within this node */
3726 for_each_active_range_index_in_nid(i
, nid
) {
3727 unsigned long start_pfn
, end_pfn
;
3728 unsigned long size_pages
;
3730 start_pfn
= max(early_node_map
[i
].start_pfn
,
3731 zone_movable_pfn
[nid
]);
3732 end_pfn
= early_node_map
[i
].end_pfn
;
3733 if (start_pfn
>= end_pfn
)
3736 /* Account for what is only usable for kernelcore */
3737 if (start_pfn
< usable_startpfn
) {
3738 unsigned long kernel_pages
;
3739 kernel_pages
= min(end_pfn
, usable_startpfn
)
3742 kernelcore_remaining
-= min(kernel_pages
,
3743 kernelcore_remaining
);
3744 required_kernelcore
-= min(kernel_pages
,
3745 required_kernelcore
);
3747 /* Continue if range is now fully accounted */
3748 if (end_pfn
<= usable_startpfn
) {
3751 * Push zone_movable_pfn to the end so
3752 * that if we have to rebalance
3753 * kernelcore across nodes, we will
3754 * not double account here
3756 zone_movable_pfn
[nid
] = end_pfn
;
3759 start_pfn
= usable_startpfn
;
3763 * The usable PFN range for ZONE_MOVABLE is from
3764 * start_pfn->end_pfn. Calculate size_pages as the
3765 * number of pages used as kernelcore
3767 size_pages
= end_pfn
- start_pfn
;
3768 if (size_pages
> kernelcore_remaining
)
3769 size_pages
= kernelcore_remaining
;
3770 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
3773 * Some kernelcore has been met, update counts and
3774 * break if the kernelcore for this node has been
3777 required_kernelcore
-= min(required_kernelcore
,
3779 kernelcore_remaining
-= size_pages
;
3780 if (!kernelcore_remaining
)
3786 * If there is still required_kernelcore, we do another pass with one
3787 * less node in the count. This will push zone_movable_pfn[nid] further
3788 * along on the nodes that still have memory until kernelcore is
3792 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
3795 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
3796 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
3797 zone_movable_pfn
[nid
] =
3798 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
3801 /* Any regular memory on that node ? */
3802 static void check_for_regular_memory(pg_data_t
*pgdat
)
3804 #ifdef CONFIG_HIGHMEM
3805 enum zone_type zone_type
;
3807 for (zone_type
= 0; zone_type
<= ZONE_NORMAL
; zone_type
++) {
3808 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
3809 if (zone
->present_pages
)
3810 node_set_state(zone_to_nid(zone
), N_NORMAL_MEMORY
);
3816 * free_area_init_nodes - Initialise all pg_data_t and zone data
3817 * @max_zone_pfn: an array of max PFNs for each zone
3819 * This will call free_area_init_node() for each active node in the system.
3820 * Using the page ranges provided by add_active_range(), the size of each
3821 * zone in each node and their holes is calculated. If the maximum PFN
3822 * between two adjacent zones match, it is assumed that the zone is empty.
3823 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
3824 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
3825 * starts where the previous one ended. For example, ZONE_DMA32 starts
3826 * at arch_max_dma_pfn.
3828 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
3833 /* Sort early_node_map as initialisation assumes it is sorted */
3836 /* Record where the zone boundaries are */
3837 memset(arch_zone_lowest_possible_pfn
, 0,
3838 sizeof(arch_zone_lowest_possible_pfn
));
3839 memset(arch_zone_highest_possible_pfn
, 0,
3840 sizeof(arch_zone_highest_possible_pfn
));
3841 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
3842 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
3843 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
3844 if (i
== ZONE_MOVABLE
)
3846 arch_zone_lowest_possible_pfn
[i
] =
3847 arch_zone_highest_possible_pfn
[i
-1];
3848 arch_zone_highest_possible_pfn
[i
] =
3849 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
3851 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
3852 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
3854 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
3855 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
3856 find_zone_movable_pfns_for_nodes(zone_movable_pfn
);
3858 /* Print out the zone ranges */
3859 printk("Zone PFN ranges:\n");
3860 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
3861 if (i
== ZONE_MOVABLE
)
3863 printk(" %-8s %8lu -> %8lu\n",
3865 arch_zone_lowest_possible_pfn
[i
],
3866 arch_zone_highest_possible_pfn
[i
]);
3869 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
3870 printk("Movable zone start PFN for each node\n");
3871 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
3872 if (zone_movable_pfn
[i
])
3873 printk(" Node %d: %lu\n", i
, zone_movable_pfn
[i
]);
3876 /* Print out the early_node_map[] */
3877 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries
);
3878 for (i
= 0; i
< nr_nodemap_entries
; i
++)
3879 printk(" %3d: %8lu -> %8lu\n", early_node_map
[i
].nid
,
3880 early_node_map
[i
].start_pfn
,
3881 early_node_map
[i
].end_pfn
);
3883 /* Initialise every node */
3884 setup_nr_node_ids();
3885 for_each_online_node(nid
) {
3886 pg_data_t
*pgdat
= NODE_DATA(nid
);
3887 free_area_init_node(nid
, pgdat
, NULL
,
3888 find_min_pfn_for_node(nid
), NULL
);
3890 /* Any memory on that node */
3891 if (pgdat
->node_present_pages
)
3892 node_set_state(nid
, N_HIGH_MEMORY
);
3893 check_for_regular_memory(pgdat
);
3897 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
3899 unsigned long long coremem
;
3903 coremem
= memparse(p
, &p
);
3904 *core
= coremem
>> PAGE_SHIFT
;
3906 /* Paranoid check that UL is enough for the coremem value */
3907 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
3913 * kernelcore=size sets the amount of memory for use for allocations that
3914 * cannot be reclaimed or migrated.
3916 static int __init
cmdline_parse_kernelcore(char *p
)
3918 return cmdline_parse_core(p
, &required_kernelcore
);
3922 * movablecore=size sets the amount of memory for use for allocations that
3923 * can be reclaimed or migrated.
3925 static int __init
cmdline_parse_movablecore(char *p
)
3927 return cmdline_parse_core(p
, &required_movablecore
);
3930 early_param("kernelcore", cmdline_parse_kernelcore
);
3931 early_param("movablecore", cmdline_parse_movablecore
);
3933 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
3936 * set_dma_reserve - set the specified number of pages reserved in the first zone
3937 * @new_dma_reserve: The number of pages to mark reserved
3939 * The per-cpu batchsize and zone watermarks are determined by present_pages.
3940 * In the DMA zone, a significant percentage may be consumed by kernel image
3941 * and other unfreeable allocations which can skew the watermarks badly. This
3942 * function may optionally be used to account for unfreeable pages in the
3943 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
3944 * smaller per-cpu batchsize.
3946 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
3948 dma_reserve
= new_dma_reserve
;
3951 #ifndef CONFIG_NEED_MULTIPLE_NODES
3952 static bootmem_data_t contig_bootmem_data
;
3953 struct pglist_data contig_page_data
= { .bdata
= &contig_bootmem_data
};
3955 EXPORT_SYMBOL(contig_page_data
);
3958 void __init
free_area_init(unsigned long *zones_size
)
3960 free_area_init_node(0, NODE_DATA(0), zones_size
,
3961 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
3964 static int page_alloc_cpu_notify(struct notifier_block
*self
,
3965 unsigned long action
, void *hcpu
)
3967 int cpu
= (unsigned long)hcpu
;
3969 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
3973 * Spill the event counters of the dead processor
3974 * into the current processors event counters.
3975 * This artificially elevates the count of the current
3978 vm_events_fold_cpu(cpu
);
3981 * Zero the differential counters of the dead processor
3982 * so that the vm statistics are consistent.
3984 * This is only okay since the processor is dead and cannot
3985 * race with what we are doing.
3987 refresh_cpu_vm_stats(cpu
);
3992 void __init
page_alloc_init(void)
3994 hotcpu_notifier(page_alloc_cpu_notify
, 0);
3998 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
3999 * or min_free_kbytes changes.
4001 static void calculate_totalreserve_pages(void)
4003 struct pglist_data
*pgdat
;
4004 unsigned long reserve_pages
= 0;
4005 enum zone_type i
, j
;
4007 for_each_online_pgdat(pgdat
) {
4008 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4009 struct zone
*zone
= pgdat
->node_zones
+ i
;
4010 unsigned long max
= 0;
4012 /* Find valid and maximum lowmem_reserve in the zone */
4013 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
4014 if (zone
->lowmem_reserve
[j
] > max
)
4015 max
= zone
->lowmem_reserve
[j
];
4018 /* we treat pages_high as reserved pages. */
4019 max
+= zone
->pages_high
;
4021 if (max
> zone
->present_pages
)
4022 max
= zone
->present_pages
;
4023 reserve_pages
+= max
;
4026 totalreserve_pages
= reserve_pages
;
4030 * setup_per_zone_lowmem_reserve - called whenever
4031 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
4032 * has a correct pages reserved value, so an adequate number of
4033 * pages are left in the zone after a successful __alloc_pages().
4035 static void setup_per_zone_lowmem_reserve(void)
4037 struct pglist_data
*pgdat
;
4038 enum zone_type j
, idx
;
4040 for_each_online_pgdat(pgdat
) {
4041 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4042 struct zone
*zone
= pgdat
->node_zones
+ j
;
4043 unsigned long present_pages
= zone
->present_pages
;
4045 zone
->lowmem_reserve
[j
] = 0;
4049 struct zone
*lower_zone
;
4053 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
4054 sysctl_lowmem_reserve_ratio
[idx
] = 1;
4056 lower_zone
= pgdat
->node_zones
+ idx
;
4057 lower_zone
->lowmem_reserve
[j
] = present_pages
/
4058 sysctl_lowmem_reserve_ratio
[idx
];
4059 present_pages
+= lower_zone
->present_pages
;
4064 /* update totalreserve_pages */
4065 calculate_totalreserve_pages();
4069 * setup_per_zone_pages_min - called when min_free_kbytes changes.
4071 * Ensures that the pages_{min,low,high} values for each zone are set correctly
4072 * with respect to min_free_kbytes.
4074 void setup_per_zone_pages_min(void)
4076 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
4077 unsigned long lowmem_pages
= 0;
4079 unsigned long flags
;
4081 /* Calculate total number of !ZONE_HIGHMEM pages */
4082 for_each_zone(zone
) {
4083 if (!is_highmem(zone
))
4084 lowmem_pages
+= zone
->present_pages
;
4087 for_each_zone(zone
) {
4090 spin_lock_irqsave(&zone
->lru_lock
, flags
);
4091 tmp
= (u64
)pages_min
* zone
->present_pages
;
4092 do_div(tmp
, lowmem_pages
);
4093 if (is_highmem(zone
)) {
4095 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
4096 * need highmem pages, so cap pages_min to a small
4099 * The (pages_high-pages_low) and (pages_low-pages_min)
4100 * deltas controls asynch page reclaim, and so should
4101 * not be capped for highmem.
4105 min_pages
= zone
->present_pages
/ 1024;
4106 if (min_pages
< SWAP_CLUSTER_MAX
)
4107 min_pages
= SWAP_CLUSTER_MAX
;
4108 if (min_pages
> 128)
4110 zone
->pages_min
= min_pages
;
4113 * If it's a lowmem zone, reserve a number of pages
4114 * proportionate to the zone's size.
4116 zone
->pages_min
= tmp
;
4119 zone
->pages_low
= zone
->pages_min
+ (tmp
>> 2);
4120 zone
->pages_high
= zone
->pages_min
+ (tmp
>> 1);
4121 setup_zone_migrate_reserve(zone
);
4122 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4125 /* update totalreserve_pages */
4126 calculate_totalreserve_pages();
4130 * Initialise min_free_kbytes.
4132 * For small machines we want it small (128k min). For large machines
4133 * we want it large (64MB max). But it is not linear, because network
4134 * bandwidth does not increase linearly with machine size. We use
4136 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
4137 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
4153 static int __init
init_per_zone_pages_min(void)
4155 unsigned long lowmem_kbytes
;
4157 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
4159 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
4160 if (min_free_kbytes
< 128)
4161 min_free_kbytes
= 128;
4162 if (min_free_kbytes
> 65536)
4163 min_free_kbytes
= 65536;
4164 setup_per_zone_pages_min();
4165 setup_per_zone_lowmem_reserve();
4168 module_init(init_per_zone_pages_min
)
4171 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
4172 * that we can call two helper functions whenever min_free_kbytes
4175 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
4176 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4178 proc_dointvec(table
, write
, file
, buffer
, length
, ppos
);
4180 setup_per_zone_pages_min();
4185 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
4186 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4191 rc
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4196 zone
->min_unmapped_pages
= (zone
->present_pages
*
4197 sysctl_min_unmapped_ratio
) / 100;
4201 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
4202 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4207 rc
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4212 zone
->min_slab_pages
= (zone
->present_pages
*
4213 sysctl_min_slab_ratio
) / 100;
4219 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
4220 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
4221 * whenever sysctl_lowmem_reserve_ratio changes.
4223 * The reserve ratio obviously has absolutely no relation with the
4224 * pages_min watermarks. The lowmem reserve ratio can only make sense
4225 * if in function of the boot time zone sizes.
4227 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
4228 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4230 proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4231 setup_per_zone_lowmem_reserve();
4236 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
4237 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
4238 * can have before it gets flushed back to buddy allocator.
4241 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
4242 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4248 ret
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4249 if (!write
|| (ret
== -EINVAL
))
4251 for_each_zone(zone
) {
4252 for_each_online_cpu(cpu
) {
4254 high
= zone
->present_pages
/ percpu_pagelist_fraction
;
4255 setup_pagelist_highmark(zone_pcp(zone
, cpu
), high
);
4261 int hashdist
= HASHDIST_DEFAULT
;
4264 static int __init
set_hashdist(char *str
)
4268 hashdist
= simple_strtoul(str
, &str
, 0);
4271 __setup("hashdist=", set_hashdist
);
4275 * allocate a large system hash table from bootmem
4276 * - it is assumed that the hash table must contain an exact power-of-2
4277 * quantity of entries
4278 * - limit is the number of hash buckets, not the total allocation size
4280 void *__init
alloc_large_system_hash(const char *tablename
,
4281 unsigned long bucketsize
,
4282 unsigned long numentries
,
4285 unsigned int *_hash_shift
,
4286 unsigned int *_hash_mask
,
4287 unsigned long limit
)
4289 unsigned long long max
= limit
;
4290 unsigned long log2qty
, size
;
4293 /* allow the kernel cmdline to have a say */
4295 /* round applicable memory size up to nearest megabyte */
4296 numentries
= nr_kernel_pages
;
4297 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
4298 numentries
>>= 20 - PAGE_SHIFT
;
4299 numentries
<<= 20 - PAGE_SHIFT
;
4301 /* limit to 1 bucket per 2^scale bytes of low memory */
4302 if (scale
> PAGE_SHIFT
)
4303 numentries
>>= (scale
- PAGE_SHIFT
);
4305 numentries
<<= (PAGE_SHIFT
- scale
);
4307 /* Make sure we've got at least a 0-order allocation.. */
4308 if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
4309 numentries
= PAGE_SIZE
/ bucketsize
;
4311 numentries
= roundup_pow_of_two(numentries
);
4313 /* limit allocation size to 1/16 total memory by default */
4315 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
4316 do_div(max
, bucketsize
);
4319 if (numentries
> max
)
4322 log2qty
= ilog2(numentries
);
4325 size
= bucketsize
<< log2qty
;
4326 if (flags
& HASH_EARLY
)
4327 table
= alloc_bootmem(size
);
4329 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
4331 unsigned long order
;
4332 for (order
= 0; ((1UL << order
) << PAGE_SHIFT
) < size
; order
++)
4334 table
= (void*) __get_free_pages(GFP_ATOMIC
, order
);
4336 * If bucketsize is not a power-of-two, we may free
4337 * some pages at the end of hash table.
4340 unsigned long alloc_end
= (unsigned long)table
+
4341 (PAGE_SIZE
<< order
);
4342 unsigned long used
= (unsigned long)table
+
4344 split_page(virt_to_page(table
), order
);
4345 while (used
< alloc_end
) {
4351 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
4354 panic("Failed to allocate %s hash table\n", tablename
);
4356 printk(KERN_INFO
"%s hash table entries: %d (order: %d, %lu bytes)\n",
4359 ilog2(size
) - PAGE_SHIFT
,
4363 *_hash_shift
= log2qty
;
4365 *_hash_mask
= (1 << log2qty
) - 1;
4370 #ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
4371 struct page
*pfn_to_page(unsigned long pfn
)
4373 return __pfn_to_page(pfn
);
4375 unsigned long page_to_pfn(struct page
*page
)
4377 return __page_to_pfn(page
);
4379 EXPORT_SYMBOL(pfn_to_page
);
4380 EXPORT_SYMBOL(page_to_pfn
);
4381 #endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */
4383 /* Return a pointer to the bitmap storing bits affecting a block of pages */
4384 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
4387 #ifdef CONFIG_SPARSEMEM
4388 return __pfn_to_section(pfn
)->pageblock_flags
;
4390 return zone
->pageblock_flags
;
4391 #endif /* CONFIG_SPARSEMEM */
4394 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
4396 #ifdef CONFIG_SPARSEMEM
4397 pfn
&= (PAGES_PER_SECTION
-1);
4398 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
4400 pfn
= pfn
- zone
->zone_start_pfn
;
4401 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
4402 #endif /* CONFIG_SPARSEMEM */
4406 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4407 * @page: The page within the block of interest
4408 * @start_bitidx: The first bit of interest to retrieve
4409 * @end_bitidx: The last bit of interest
4410 * returns pageblock_bits flags
4412 unsigned long get_pageblock_flags_group(struct page
*page
,
4413 int start_bitidx
, int end_bitidx
)
4416 unsigned long *bitmap
;
4417 unsigned long pfn
, bitidx
;
4418 unsigned long flags
= 0;
4419 unsigned long value
= 1;
4421 zone
= page_zone(page
);
4422 pfn
= page_to_pfn(page
);
4423 bitmap
= get_pageblock_bitmap(zone
, pfn
);
4424 bitidx
= pfn_to_bitidx(zone
, pfn
);
4426 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
4427 if (test_bit(bitidx
+ start_bitidx
, bitmap
))
4434 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
4435 * @page: The page within the block of interest
4436 * @start_bitidx: The first bit of interest
4437 * @end_bitidx: The last bit of interest
4438 * @flags: The flags to set
4440 void set_pageblock_flags_group(struct page
*page
, unsigned long flags
,
4441 int start_bitidx
, int end_bitidx
)
4444 unsigned long *bitmap
;
4445 unsigned long pfn
, bitidx
;
4446 unsigned long value
= 1;
4448 zone
= page_zone(page
);
4449 pfn
= page_to_pfn(page
);
4450 bitmap
= get_pageblock_bitmap(zone
, pfn
);
4451 bitidx
= pfn_to_bitidx(zone
, pfn
);
4453 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
4455 __set_bit(bitidx
+ start_bitidx
, bitmap
);
4457 __clear_bit(bitidx
+ start_bitidx
, bitmap
);
4461 * This is designed as sub function...plz see page_isolation.c also.
4462 * set/clear page block's type to be ISOLATE.
4463 * page allocater never alloc memory from ISOLATE block.
4466 int set_migratetype_isolate(struct page
*page
)
4469 unsigned long flags
;
4472 zone
= page_zone(page
);
4473 spin_lock_irqsave(&zone
->lock
, flags
);
4475 * In future, more migrate types will be able to be isolation target.
4477 if (get_pageblock_migratetype(page
) != MIGRATE_MOVABLE
)
4479 set_pageblock_migratetype(page
, MIGRATE_ISOLATE
);
4480 move_freepages_block(zone
, page
, MIGRATE_ISOLATE
);
4483 spin_unlock_irqrestore(&zone
->lock
, flags
);
4489 void unset_migratetype_isolate(struct page
*page
)
4492 unsigned long flags
;
4493 zone
= page_zone(page
);
4494 spin_lock_irqsave(&zone
->lock
, flags
);
4495 if (get_pageblock_migratetype(page
) != MIGRATE_ISOLATE
)
4497 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4498 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
4500 spin_unlock_irqrestore(&zone
->lock
, flags
);
4503 #ifdef CONFIG_MEMORY_HOTREMOVE
4505 * All pages in the range must be isolated before calling this.
4508 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
4514 unsigned long flags
;
4515 /* find the first valid pfn */
4516 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
4521 zone
= page_zone(pfn_to_page(pfn
));
4522 spin_lock_irqsave(&zone
->lock
, flags
);
4524 while (pfn
< end_pfn
) {
4525 if (!pfn_valid(pfn
)) {
4529 page
= pfn_to_page(pfn
);
4530 BUG_ON(page_count(page
));
4531 BUG_ON(!PageBuddy(page
));
4532 order
= page_order(page
);
4533 #ifdef CONFIG_DEBUG_VM
4534 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
4535 pfn
, 1 << order
, end_pfn
);
4537 list_del(&page
->lru
);
4538 rmv_page_order(page
);
4539 zone
->free_area
[order
].nr_free
--;
4540 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
4542 for (i
= 0; i
< (1 << order
); i
++)
4543 SetPageReserved((page
+i
));
4544 pfn
+= (1 << order
);
4546 spin_unlock_irqrestore(&zone
->lock
, flags
);