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>
46 #include <linux/memcontrol.h>
48 #include <asm/tlbflush.h>
49 #include <asm/div64.h>
53 * Array of node states.
55 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
56 [N_POSSIBLE
] = NODE_MASK_ALL
,
57 [N_ONLINE
] = { { [0] = 1UL } },
59 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
61 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
63 [N_CPU
] = { { [0] = 1UL } },
66 EXPORT_SYMBOL(node_states
);
68 unsigned long totalram_pages __read_mostly
;
69 unsigned long totalreserve_pages __read_mostly
;
71 int percpu_pagelist_fraction
;
73 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
74 int pageblock_order __read_mostly
;
77 static void __free_pages_ok(struct page
*page
, unsigned int order
);
80 * results with 256, 32 in the lowmem_reserve sysctl:
81 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
82 * 1G machine -> (16M dma, 784M normal, 224M high)
83 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
84 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
85 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
87 * TBD: should special case ZONE_DMA32 machines here - in those we normally
88 * don't need any ZONE_NORMAL reservation
90 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
91 #ifdef CONFIG_ZONE_DMA
94 #ifdef CONFIG_ZONE_DMA32
103 EXPORT_SYMBOL(totalram_pages
);
105 static char * const zone_names
[MAX_NR_ZONES
] = {
106 #ifdef CONFIG_ZONE_DMA
109 #ifdef CONFIG_ZONE_DMA32
113 #ifdef CONFIG_HIGHMEM
119 int min_free_kbytes
= 1024;
121 unsigned long __meminitdata nr_kernel_pages
;
122 unsigned long __meminitdata nr_all_pages
;
123 static unsigned long __meminitdata dma_reserve
;
125 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
127 * MAX_ACTIVE_REGIONS determines the maximum number of distinct
128 * ranges of memory (RAM) that may be registered with add_active_range().
129 * Ranges passed to add_active_range() will be merged if possible
130 * so the number of times add_active_range() can be called is
131 * related to the number of nodes and the number of holes
133 #ifdef CONFIG_MAX_ACTIVE_REGIONS
134 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */
135 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
137 #if MAX_NUMNODES >= 32
138 /* If there can be many nodes, allow up to 50 holes per node */
139 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
141 /* By default, allow up to 256 distinct regions */
142 #define MAX_ACTIVE_REGIONS 256
146 static struct node_active_region __meminitdata early_node_map
[MAX_ACTIVE_REGIONS
];
147 static int __meminitdata nr_nodemap_entries
;
148 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
149 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
150 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
151 static unsigned long __meminitdata node_boundary_start_pfn
[MAX_NUMNODES
];
152 static unsigned long __meminitdata node_boundary_end_pfn
[MAX_NUMNODES
];
153 #endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
154 unsigned long __initdata required_kernelcore
;
155 static unsigned long __initdata required_movablecore
;
156 unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
158 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
160 EXPORT_SYMBOL(movable_zone
);
161 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
164 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
165 EXPORT_SYMBOL(nr_node_ids
);
168 int page_group_by_mobility_disabled __read_mostly
;
170 static void set_pageblock_migratetype(struct page
*page
, int migratetype
)
172 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
173 PB_migrate
, PB_migrate_end
);
176 #ifdef CONFIG_DEBUG_VM
177 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
181 unsigned long pfn
= page_to_pfn(page
);
184 seq
= zone_span_seqbegin(zone
);
185 if (pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
187 else if (pfn
< zone
->zone_start_pfn
)
189 } while (zone_span_seqretry(zone
, seq
));
194 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
196 if (!pfn_valid_within(page_to_pfn(page
)))
198 if (zone
!= page_zone(page
))
204 * Temporary debugging check for pages not lying within a given zone.
206 static int bad_range(struct zone
*zone
, struct page
*page
)
208 if (page_outside_zone_boundaries(zone
, page
))
210 if (!page_is_consistent(zone
, page
))
216 static inline int bad_range(struct zone
*zone
, struct page
*page
)
222 static void bad_page(struct page
*page
)
224 printk(KERN_EMERG
"Bad page state in process '%s'\n"
225 KERN_EMERG
"page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n"
226 KERN_EMERG
"Trying to fix it up, but a reboot is needed\n"
227 KERN_EMERG
"Backtrace:\n",
228 current
->comm
, page
, (int)(2*sizeof(unsigned long)),
229 (unsigned long)page
->flags
, page
->mapping
,
230 page_mapcount(page
), page_count(page
));
232 page
->flags
&= ~(1 << PG_lru
|
242 set_page_count(page
, 0);
243 reset_page_mapcount(page
);
244 page
->mapping
= NULL
;
245 add_taint(TAINT_BAD_PAGE
);
249 * Higher-order pages are called "compound pages". They are structured thusly:
251 * The first PAGE_SIZE page is called the "head page".
253 * The remaining PAGE_SIZE pages are called "tail pages".
255 * All pages have PG_compound set. All pages have their ->private pointing at
256 * the head page (even the head page has this).
258 * The first tail page's ->lru.next holds the address of the compound page's
259 * put_page() function. Its ->lru.prev holds the order of allocation.
260 * This usage means that zero-order pages may not be compound.
263 static void free_compound_page(struct page
*page
)
265 __free_pages_ok(page
, compound_order(page
));
268 static void prep_compound_page(struct page
*page
, unsigned long order
)
271 int nr_pages
= 1 << order
;
273 set_compound_page_dtor(page
, free_compound_page
);
274 set_compound_order(page
, order
);
276 for (i
= 1; i
< nr_pages
; i
++) {
277 struct page
*p
= page
+ i
;
280 p
->first_page
= page
;
284 static void destroy_compound_page(struct page
*page
, unsigned long order
)
287 int nr_pages
= 1 << order
;
289 if (unlikely(compound_order(page
) != order
))
292 if (unlikely(!PageHead(page
)))
294 __ClearPageHead(page
);
295 for (i
= 1; i
< nr_pages
; i
++) {
296 struct page
*p
= page
+ i
;
298 if (unlikely(!PageTail(p
) |
299 (p
->first_page
!= page
)))
305 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
310 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
311 * and __GFP_HIGHMEM from hard or soft interrupt context.
313 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
314 for (i
= 0; i
< (1 << order
); i
++)
315 clear_highpage(page
+ i
);
318 static inline void set_page_order(struct page
*page
, int order
)
320 set_page_private(page
, order
);
321 __SetPageBuddy(page
);
324 static inline void rmv_page_order(struct page
*page
)
326 __ClearPageBuddy(page
);
327 set_page_private(page
, 0);
331 * Locate the struct page for both the matching buddy in our
332 * pair (buddy1) and the combined O(n+1) page they form (page).
334 * 1) Any buddy B1 will have an order O twin B2 which satisfies
335 * the following equation:
337 * For example, if the starting buddy (buddy2) is #8 its order
339 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
341 * 2) Any buddy B will have an order O+1 parent P which
342 * satisfies the following equation:
345 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
347 static inline struct page
*
348 __page_find_buddy(struct page
*page
, unsigned long page_idx
, unsigned int order
)
350 unsigned long buddy_idx
= page_idx
^ (1 << order
);
352 return page
+ (buddy_idx
- page_idx
);
355 static inline unsigned long
356 __find_combined_index(unsigned long page_idx
, unsigned int order
)
358 return (page_idx
& ~(1 << order
));
362 * This function checks whether a page is free && is the buddy
363 * we can do coalesce a page and its buddy if
364 * (a) the buddy is not in a hole &&
365 * (b) the buddy is in the buddy system &&
366 * (c) a page and its buddy have the same order &&
367 * (d) a page and its buddy are in the same zone.
369 * For recording whether a page is in the buddy system, we use PG_buddy.
370 * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
372 * For recording page's order, we use page_private(page).
374 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
377 if (!pfn_valid_within(page_to_pfn(buddy
)))
380 if (page_zone_id(page
) != page_zone_id(buddy
))
383 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
384 BUG_ON(page_count(buddy
) != 0);
391 * Freeing function for a buddy system allocator.
393 * The concept of a buddy system is to maintain direct-mapped table
394 * (containing bit values) for memory blocks of various "orders".
395 * The bottom level table contains the map for the smallest allocatable
396 * units of memory (here, pages), and each level above it describes
397 * pairs of units from the levels below, hence, "buddies".
398 * At a high level, all that happens here is marking the table entry
399 * at the bottom level available, and propagating the changes upward
400 * as necessary, plus some accounting needed to play nicely with other
401 * parts of the VM system.
402 * At each level, we keep a list of pages, which are heads of continuous
403 * free pages of length of (1 << order) and marked with PG_buddy. Page's
404 * order is recorded in page_private(page) field.
405 * So when we are allocating or freeing one, we can derive the state of the
406 * other. That is, if we allocate a small block, and both were
407 * free, the remainder of the region must be split into blocks.
408 * If a block is freed, and its buddy is also free, then this
409 * triggers coalescing into a block of larger size.
414 static inline void __free_one_page(struct page
*page
,
415 struct zone
*zone
, unsigned int order
)
417 unsigned long page_idx
;
418 int order_size
= 1 << order
;
419 int migratetype
= get_pageblock_migratetype(page
);
421 if (unlikely(PageCompound(page
)))
422 destroy_compound_page(page
, order
);
424 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
426 VM_BUG_ON(page_idx
& (order_size
- 1));
427 VM_BUG_ON(bad_range(zone
, page
));
429 __mod_zone_page_state(zone
, NR_FREE_PAGES
, order_size
);
430 while (order
< MAX_ORDER
-1) {
431 unsigned long combined_idx
;
434 buddy
= __page_find_buddy(page
, page_idx
, order
);
435 if (!page_is_buddy(page
, buddy
, order
))
436 break; /* Move the buddy up one level. */
438 list_del(&buddy
->lru
);
439 zone
->free_area
[order
].nr_free
--;
440 rmv_page_order(buddy
);
441 combined_idx
= __find_combined_index(page_idx
, order
);
442 page
= page
+ (combined_idx
- page_idx
);
443 page_idx
= combined_idx
;
446 set_page_order(page
, order
);
448 &zone
->free_area
[order
].free_list
[migratetype
]);
449 zone
->free_area
[order
].nr_free
++;
452 static inline int free_pages_check(struct page
*page
)
454 if (unlikely(page_mapcount(page
) |
455 (page
->mapping
!= NULL
) |
456 (page_count(page
) != 0) |
469 __ClearPageDirty(page
);
471 * For now, we report if PG_reserved was found set, but do not
472 * clear it, and do not free the page. But we shall soon need
473 * to do more, for when the ZERO_PAGE count wraps negative.
475 return PageReserved(page
);
479 * Frees a list of pages.
480 * Assumes all pages on list are in same zone, and of same order.
481 * count is the number of pages to free.
483 * If the zone was previously in an "all pages pinned" state then look to
484 * see if this freeing clears that state.
486 * And clear the zone's pages_scanned counter, to hold off the "all pages are
487 * pinned" detection logic.
489 static void free_pages_bulk(struct zone
*zone
, int count
,
490 struct list_head
*list
, int order
)
492 spin_lock(&zone
->lock
);
493 zone_clear_flag(zone
, ZONE_ALL_UNRECLAIMABLE
);
494 zone
->pages_scanned
= 0;
498 VM_BUG_ON(list_empty(list
));
499 page
= list_entry(list
->prev
, struct page
, lru
);
500 /* have to delete it as __free_one_page list manipulates */
501 list_del(&page
->lru
);
502 __free_one_page(page
, zone
, order
);
504 spin_unlock(&zone
->lock
);
507 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
)
509 spin_lock(&zone
->lock
);
510 zone_clear_flag(zone
, ZONE_ALL_UNRECLAIMABLE
);
511 zone
->pages_scanned
= 0;
512 __free_one_page(page
, zone
, order
);
513 spin_unlock(&zone
->lock
);
516 static void __free_pages_ok(struct page
*page
, unsigned int order
)
522 for (i
= 0 ; i
< (1 << order
) ; ++i
)
523 reserved
+= free_pages_check(page
+ i
);
527 if (!PageHighMem(page
))
528 debug_check_no_locks_freed(page_address(page
),PAGE_SIZE
<<order
);
529 arch_free_page(page
, order
);
530 kernel_map_pages(page
, 1 << order
, 0);
532 local_irq_save(flags
);
533 __count_vm_events(PGFREE
, 1 << order
);
534 free_one_page(page_zone(page
), page
, order
);
535 local_irq_restore(flags
);
539 * permit the bootmem allocator to evade page validation on high-order frees
541 void __init
__free_pages_bootmem(struct page
*page
, unsigned int order
)
544 __ClearPageReserved(page
);
545 set_page_count(page
, 0);
546 set_page_refcounted(page
);
552 for (loop
= 0; loop
< BITS_PER_LONG
; loop
++) {
553 struct page
*p
= &page
[loop
];
555 if (loop
+ 1 < BITS_PER_LONG
)
557 __ClearPageReserved(p
);
558 set_page_count(p
, 0);
561 set_page_refcounted(page
);
562 __free_pages(page
, order
);
568 * The order of subdivision here is critical for the IO subsystem.
569 * Please do not alter this order without good reasons and regression
570 * testing. Specifically, as large blocks of memory are subdivided,
571 * the order in which smaller blocks are delivered depends on the order
572 * they're subdivided in this function. This is the primary factor
573 * influencing the order in which pages are delivered to the IO
574 * subsystem according to empirical testing, and this is also justified
575 * by considering the behavior of a buddy system containing a single
576 * large block of memory acted on by a series of small allocations.
577 * This behavior is a critical factor in sglist merging's success.
581 static inline void expand(struct zone
*zone
, struct page
*page
,
582 int low
, int high
, struct free_area
*area
,
585 unsigned long size
= 1 << high
;
591 VM_BUG_ON(bad_range(zone
, &page
[size
]));
592 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
594 set_page_order(&page
[size
], high
);
599 * This page is about to be returned from the page allocator
601 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
603 if (unlikely(page_mapcount(page
) |
604 (page
->mapping
!= NULL
) |
605 (page_count(page
) != 0) |
620 * For now, we report if PG_reserved was found set, but do not
621 * clear it, and do not allocate the page: as a safety net.
623 if (PageReserved(page
))
626 page
->flags
&= ~(1 << PG_uptodate
| 1 << PG_error
| 1 << PG_readahead
|
627 1 << PG_referenced
| 1 << PG_arch_1
|
628 1 << PG_owner_priv_1
| 1 << PG_mappedtodisk
);
629 set_page_private(page
, 0);
630 set_page_refcounted(page
);
632 arch_alloc_page(page
, order
);
633 kernel_map_pages(page
, 1 << order
, 1);
635 if (gfp_flags
& __GFP_ZERO
)
636 prep_zero_page(page
, order
, gfp_flags
);
638 if (order
&& (gfp_flags
& __GFP_COMP
))
639 prep_compound_page(page
, order
);
645 * Go through the free lists for the given migratetype and remove
646 * the smallest available page from the freelists
648 static struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
651 unsigned int current_order
;
652 struct free_area
* area
;
655 /* Find a page of the appropriate size in the preferred list */
656 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
657 area
= &(zone
->free_area
[current_order
]);
658 if (list_empty(&area
->free_list
[migratetype
]))
661 page
= list_entry(area
->free_list
[migratetype
].next
,
663 list_del(&page
->lru
);
664 rmv_page_order(page
);
666 __mod_zone_page_state(zone
, NR_FREE_PAGES
, - (1UL << order
));
667 expand(zone
, page
, order
, current_order
, area
, migratetype
);
676 * This array describes the order lists are fallen back to when
677 * the free lists for the desirable migrate type are depleted
679 static int fallbacks
[MIGRATE_TYPES
][MIGRATE_TYPES
-1] = {
680 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
681 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
682 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
683 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
, MIGRATE_RESERVE
, MIGRATE_RESERVE
}, /* Never used */
687 * Move the free pages in a range to the free lists of the requested type.
688 * Note that start_page and end_pages are not aligned on a pageblock
689 * boundary. If alignment is required, use move_freepages_block()
691 int move_freepages(struct zone
*zone
,
692 struct page
*start_page
, struct page
*end_page
,
699 #ifndef CONFIG_HOLES_IN_ZONE
701 * page_zone is not safe to call in this context when
702 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
703 * anyway as we check zone boundaries in move_freepages_block().
704 * Remove at a later date when no bug reports exist related to
705 * grouping pages by mobility
707 BUG_ON(page_zone(start_page
) != page_zone(end_page
));
710 for (page
= start_page
; page
<= end_page
;) {
711 if (!pfn_valid_within(page_to_pfn(page
))) {
716 if (!PageBuddy(page
)) {
721 order
= page_order(page
);
722 list_del(&page
->lru
);
724 &zone
->free_area
[order
].free_list
[migratetype
]);
726 pages_moved
+= 1 << order
;
732 int move_freepages_block(struct zone
*zone
, struct page
*page
, int migratetype
)
734 unsigned long start_pfn
, end_pfn
;
735 struct page
*start_page
, *end_page
;
737 start_pfn
= page_to_pfn(page
);
738 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
739 start_page
= pfn_to_page(start_pfn
);
740 end_page
= start_page
+ pageblock_nr_pages
- 1;
741 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
743 /* Do not cross zone boundaries */
744 if (start_pfn
< zone
->zone_start_pfn
)
746 if (end_pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
749 return move_freepages(zone
, start_page
, end_page
, migratetype
);
752 /* Remove an element from the buddy allocator from the fallback list */
753 static struct page
*__rmqueue_fallback(struct zone
*zone
, int order
,
754 int start_migratetype
)
756 struct free_area
* area
;
761 /* Find the largest possible block of pages in the other list */
762 for (current_order
= MAX_ORDER
-1; current_order
>= order
;
764 for (i
= 0; i
< MIGRATE_TYPES
- 1; i
++) {
765 migratetype
= fallbacks
[start_migratetype
][i
];
767 /* MIGRATE_RESERVE handled later if necessary */
768 if (migratetype
== MIGRATE_RESERVE
)
771 area
= &(zone
->free_area
[current_order
]);
772 if (list_empty(&area
->free_list
[migratetype
]))
775 page
= list_entry(area
->free_list
[migratetype
].next
,
780 * If breaking a large block of pages, move all free
781 * pages to the preferred allocation list. If falling
782 * back for a reclaimable kernel allocation, be more
783 * agressive about taking ownership of free pages
785 if (unlikely(current_order
>= (pageblock_order
>> 1)) ||
786 start_migratetype
== MIGRATE_RECLAIMABLE
) {
788 pages
= move_freepages_block(zone
, page
,
791 /* Claim the whole block if over half of it is free */
792 if (pages
>= (1 << (pageblock_order
-1)))
793 set_pageblock_migratetype(page
,
796 migratetype
= start_migratetype
;
799 /* Remove the page from the freelists */
800 list_del(&page
->lru
);
801 rmv_page_order(page
);
802 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
805 if (current_order
== pageblock_order
)
806 set_pageblock_migratetype(page
,
809 expand(zone
, page
, order
, current_order
, area
, migratetype
);
814 /* Use MIGRATE_RESERVE rather than fail an allocation */
815 return __rmqueue_smallest(zone
, order
, MIGRATE_RESERVE
);
819 * Do the hard work of removing an element from the buddy allocator.
820 * Call me with the zone->lock already held.
822 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
827 page
= __rmqueue_smallest(zone
, order
, migratetype
);
830 page
= __rmqueue_fallback(zone
, order
, migratetype
);
836 * Obtain a specified number of elements from the buddy allocator, all under
837 * a single hold of the lock, for efficiency. Add them to the supplied list.
838 * Returns the number of new pages which were placed at *list.
840 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
841 unsigned long count
, struct list_head
*list
,
846 spin_lock(&zone
->lock
);
847 for (i
= 0; i
< count
; ++i
) {
848 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
849 if (unlikely(page
== NULL
))
853 * Split buddy pages returned by expand() are received here
854 * in physical page order. The page is added to the callers and
855 * list and the list head then moves forward. From the callers
856 * perspective, the linked list is ordered by page number in
857 * some conditions. This is useful for IO devices that can
858 * merge IO requests if the physical pages are ordered
861 list_add(&page
->lru
, list
);
862 set_page_private(page
, migratetype
);
865 spin_unlock(&zone
->lock
);
871 * Called from the vmstat counter updater to drain pagesets of this
872 * currently executing processor on remote nodes after they have
875 * Note that this function must be called with the thread pinned to
876 * a single processor.
878 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
883 local_irq_save(flags
);
884 if (pcp
->count
>= pcp
->batch
)
885 to_drain
= pcp
->batch
;
887 to_drain
= pcp
->count
;
888 free_pages_bulk(zone
, to_drain
, &pcp
->list
, 0);
889 pcp
->count
-= to_drain
;
890 local_irq_restore(flags
);
895 * Drain pages of the indicated processor.
897 * The processor must either be the current processor and the
898 * thread pinned to the current processor or a processor that
901 static void drain_pages(unsigned int cpu
)
906 for_each_zone(zone
) {
907 struct per_cpu_pageset
*pset
;
908 struct per_cpu_pages
*pcp
;
910 if (!populated_zone(zone
))
913 pset
= zone_pcp(zone
, cpu
);
916 local_irq_save(flags
);
917 free_pages_bulk(zone
, pcp
->count
, &pcp
->list
, 0);
919 local_irq_restore(flags
);
924 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
926 void drain_local_pages(void *arg
)
928 drain_pages(smp_processor_id());
932 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
934 void drain_all_pages(void)
936 on_each_cpu(drain_local_pages
, NULL
, 0, 1);
939 #ifdef CONFIG_HIBERNATION
941 void mark_free_pages(struct zone
*zone
)
943 unsigned long pfn
, max_zone_pfn
;
946 struct list_head
*curr
;
948 if (!zone
->spanned_pages
)
951 spin_lock_irqsave(&zone
->lock
, flags
);
953 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
954 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
955 if (pfn_valid(pfn
)) {
956 struct page
*page
= pfn_to_page(pfn
);
958 if (!swsusp_page_is_forbidden(page
))
959 swsusp_unset_page_free(page
);
962 for_each_migratetype_order(order
, t
) {
963 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
966 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
967 for (i
= 0; i
< (1UL << order
); i
++)
968 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
971 spin_unlock_irqrestore(&zone
->lock
, flags
);
973 #endif /* CONFIG_PM */
976 * Free a 0-order page
978 static void free_hot_cold_page(struct page
*page
, int cold
)
980 struct zone
*zone
= page_zone(page
);
981 struct per_cpu_pages
*pcp
;
985 page
->mapping
= NULL
;
986 if (free_pages_check(page
))
989 if (!PageHighMem(page
))
990 debug_check_no_locks_freed(page_address(page
), PAGE_SIZE
);
991 VM_BUG_ON(page_get_page_cgroup(page
));
992 arch_free_page(page
, 0);
993 kernel_map_pages(page
, 1, 0);
995 pcp
= &zone_pcp(zone
, get_cpu())->pcp
;
996 local_irq_save(flags
);
997 __count_vm_event(PGFREE
);
999 list_add_tail(&page
->lru
, &pcp
->list
);
1001 list_add(&page
->lru
, &pcp
->list
);
1002 set_page_private(page
, get_pageblock_migratetype(page
));
1004 if (pcp
->count
>= pcp
->high
) {
1005 free_pages_bulk(zone
, pcp
->batch
, &pcp
->list
, 0);
1006 pcp
->count
-= pcp
->batch
;
1008 local_irq_restore(flags
);
1012 void free_hot_page(struct page
*page
)
1014 free_hot_cold_page(page
, 0);
1017 void free_cold_page(struct page
*page
)
1019 free_hot_cold_page(page
, 1);
1023 * split_page takes a non-compound higher-order page, and splits it into
1024 * n (1<<order) sub-pages: page[0..n]
1025 * Each sub-page must be freed individually.
1027 * Note: this is probably too low level an operation for use in drivers.
1028 * Please consult with lkml before using this in your driver.
1030 void split_page(struct page
*page
, unsigned int order
)
1034 VM_BUG_ON(PageCompound(page
));
1035 VM_BUG_ON(!page_count(page
));
1036 for (i
= 1; i
< (1 << order
); i
++)
1037 set_page_refcounted(page
+ i
);
1041 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1042 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1045 static struct page
*buffered_rmqueue(struct zonelist
*zonelist
,
1046 struct zone
*zone
, int order
, gfp_t gfp_flags
)
1048 unsigned long flags
;
1050 int cold
= !!(gfp_flags
& __GFP_COLD
);
1052 int migratetype
= allocflags_to_migratetype(gfp_flags
);
1056 if (likely(order
== 0)) {
1057 struct per_cpu_pages
*pcp
;
1059 pcp
= &zone_pcp(zone
, cpu
)->pcp
;
1060 local_irq_save(flags
);
1062 pcp
->count
= rmqueue_bulk(zone
, 0,
1063 pcp
->batch
, &pcp
->list
, migratetype
);
1064 if (unlikely(!pcp
->count
))
1068 /* Find a page of the appropriate migrate type */
1070 list_for_each_entry_reverse(page
, &pcp
->list
, lru
)
1071 if (page_private(page
) == migratetype
)
1074 list_for_each_entry(page
, &pcp
->list
, lru
)
1075 if (page_private(page
) == migratetype
)
1079 /* Allocate more to the pcp list if necessary */
1080 if (unlikely(&page
->lru
== &pcp
->list
)) {
1081 pcp
->count
+= rmqueue_bulk(zone
, 0,
1082 pcp
->batch
, &pcp
->list
, migratetype
);
1083 page
= list_entry(pcp
->list
.next
, struct page
, lru
);
1086 list_del(&page
->lru
);
1089 spin_lock_irqsave(&zone
->lock
, flags
);
1090 page
= __rmqueue(zone
, order
, migratetype
);
1091 spin_unlock(&zone
->lock
);
1096 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
1097 zone_statistics(zonelist
, zone
);
1098 local_irq_restore(flags
);
1101 VM_BUG_ON(bad_range(zone
, page
));
1102 if (prep_new_page(page
, order
, gfp_flags
))
1107 local_irq_restore(flags
);
1112 #define ALLOC_NO_WATERMARKS 0x01 /* don't check watermarks at all */
1113 #define ALLOC_WMARK_MIN 0x02 /* use pages_min watermark */
1114 #define ALLOC_WMARK_LOW 0x04 /* use pages_low watermark */
1115 #define ALLOC_WMARK_HIGH 0x08 /* use pages_high watermark */
1116 #define ALLOC_HARDER 0x10 /* try to alloc harder */
1117 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
1118 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
1120 #ifdef CONFIG_FAIL_PAGE_ALLOC
1122 static struct fail_page_alloc_attr
{
1123 struct fault_attr attr
;
1125 u32 ignore_gfp_highmem
;
1126 u32 ignore_gfp_wait
;
1129 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1131 struct dentry
*ignore_gfp_highmem_file
;
1132 struct dentry
*ignore_gfp_wait_file
;
1133 struct dentry
*min_order_file
;
1135 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1137 } fail_page_alloc
= {
1138 .attr
= FAULT_ATTR_INITIALIZER
,
1139 .ignore_gfp_wait
= 1,
1140 .ignore_gfp_highmem
= 1,
1144 static int __init
setup_fail_page_alloc(char *str
)
1146 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
1148 __setup("fail_page_alloc=", setup_fail_page_alloc
);
1150 static int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1152 if (order
< fail_page_alloc
.min_order
)
1154 if (gfp_mask
& __GFP_NOFAIL
)
1156 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
1158 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
1161 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
1164 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1166 static int __init
fail_page_alloc_debugfs(void)
1168 mode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
1172 err
= init_fault_attr_dentries(&fail_page_alloc
.attr
,
1176 dir
= fail_page_alloc
.attr
.dentries
.dir
;
1178 fail_page_alloc
.ignore_gfp_wait_file
=
1179 debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
1180 &fail_page_alloc
.ignore_gfp_wait
);
1182 fail_page_alloc
.ignore_gfp_highmem_file
=
1183 debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
1184 &fail_page_alloc
.ignore_gfp_highmem
);
1185 fail_page_alloc
.min_order_file
=
1186 debugfs_create_u32("min-order", mode
, dir
,
1187 &fail_page_alloc
.min_order
);
1189 if (!fail_page_alloc
.ignore_gfp_wait_file
||
1190 !fail_page_alloc
.ignore_gfp_highmem_file
||
1191 !fail_page_alloc
.min_order_file
) {
1193 debugfs_remove(fail_page_alloc
.ignore_gfp_wait_file
);
1194 debugfs_remove(fail_page_alloc
.ignore_gfp_highmem_file
);
1195 debugfs_remove(fail_page_alloc
.min_order_file
);
1196 cleanup_fault_attr_dentries(&fail_page_alloc
.attr
);
1202 late_initcall(fail_page_alloc_debugfs
);
1204 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1206 #else /* CONFIG_FAIL_PAGE_ALLOC */
1208 static inline int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1213 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1216 * Return 1 if free pages are above 'mark'. This takes into account the order
1217 * of the allocation.
1219 int zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1220 int classzone_idx
, int alloc_flags
)
1222 /* free_pages my go negative - that's OK */
1224 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
) - (1 << order
) + 1;
1227 if (alloc_flags
& ALLOC_HIGH
)
1229 if (alloc_flags
& ALLOC_HARDER
)
1232 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
1234 for (o
= 0; o
< order
; o
++) {
1235 /* At the next order, this order's pages become unavailable */
1236 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1238 /* Require fewer higher order pages to be free */
1241 if (free_pages
<= min
)
1249 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1250 * skip over zones that are not allowed by the cpuset, or that have
1251 * been recently (in last second) found to be nearly full. See further
1252 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1253 * that have to skip over a lot of full or unallowed zones.
1255 * If the zonelist cache is present in the passed in zonelist, then
1256 * returns a pointer to the allowed node mask (either the current
1257 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1259 * If the zonelist cache is not available for this zonelist, does
1260 * nothing and returns NULL.
1262 * If the fullzones BITMAP in the zonelist cache is stale (more than
1263 * a second since last zap'd) then we zap it out (clear its bits.)
1265 * We hold off even calling zlc_setup, until after we've checked the
1266 * first zone in the zonelist, on the theory that most allocations will
1267 * be satisfied from that first zone, so best to examine that zone as
1268 * quickly as we can.
1270 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1272 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1273 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1275 zlc
= zonelist
->zlcache_ptr
;
1279 if (jiffies
- zlc
->last_full_zap
> 1 * HZ
) {
1280 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1281 zlc
->last_full_zap
= jiffies
;
1284 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1285 &cpuset_current_mems_allowed
:
1286 &node_states
[N_HIGH_MEMORY
];
1287 return allowednodes
;
1291 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1292 * if it is worth looking at further for free memory:
1293 * 1) Check that the zone isn't thought to be full (doesn't have its
1294 * bit set in the zonelist_cache fullzones BITMAP).
1295 * 2) Check that the zones node (obtained from the zonelist_cache
1296 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1297 * Return true (non-zero) if zone is worth looking at further, or
1298 * else return false (zero) if it is not.
1300 * This check -ignores- the distinction between various watermarks,
1301 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1302 * found to be full for any variation of these watermarks, it will
1303 * be considered full for up to one second by all requests, unless
1304 * we are so low on memory on all allowed nodes that we are forced
1305 * into the second scan of the zonelist.
1307 * In the second scan we ignore this zonelist cache and exactly
1308 * apply the watermarks to all zones, even it is slower to do so.
1309 * We are low on memory in the second scan, and should leave no stone
1310 * unturned looking for a free page.
1312 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zone
**z
,
1313 nodemask_t
*allowednodes
)
1315 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1316 int i
; /* index of *z in zonelist zones */
1317 int n
; /* node that zone *z is on */
1319 zlc
= zonelist
->zlcache_ptr
;
1323 i
= z
- zonelist
->zones
;
1326 /* This zone is worth trying if it is allowed but not full */
1327 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1331 * Given 'z' scanning a zonelist, set the corresponding bit in
1332 * zlc->fullzones, so that subsequent attempts to allocate a page
1333 * from that zone don't waste time re-examining it.
1335 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zone
**z
)
1337 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1338 int i
; /* index of *z in zonelist zones */
1340 zlc
= zonelist
->zlcache_ptr
;
1344 i
= z
- zonelist
->zones
;
1346 set_bit(i
, zlc
->fullzones
);
1349 #else /* CONFIG_NUMA */
1351 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1356 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zone
**z
,
1357 nodemask_t
*allowednodes
)
1362 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zone
**z
)
1365 #endif /* CONFIG_NUMA */
1368 * get_page_from_freelist goes through the zonelist trying to allocate
1371 static struct page
*
1372 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
,
1373 struct zonelist
*zonelist
, int alloc_flags
)
1376 struct page
*page
= NULL
;
1377 int classzone_idx
= zone_idx(zonelist
->zones
[0]);
1379 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1380 int zlc_active
= 0; /* set if using zonelist_cache */
1381 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1382 enum zone_type highest_zoneidx
= -1; /* Gets set for policy zonelists */
1386 * Scan zonelist, looking for a zone with enough free.
1387 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1389 z
= zonelist
->zones
;
1393 * In NUMA, this could be a policy zonelist which contains
1394 * zones that may not be allowed by the current gfp_mask.
1395 * Check the zone is allowed by the current flags
1397 if (unlikely(alloc_should_filter_zonelist(zonelist
))) {
1398 if (highest_zoneidx
== -1)
1399 highest_zoneidx
= gfp_zone(gfp_mask
);
1400 if (zone_idx(*z
) > highest_zoneidx
)
1404 if (NUMA_BUILD
&& zlc_active
&&
1405 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1408 if ((alloc_flags
& ALLOC_CPUSET
) &&
1409 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1412 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
1414 if (alloc_flags
& ALLOC_WMARK_MIN
)
1415 mark
= zone
->pages_min
;
1416 else if (alloc_flags
& ALLOC_WMARK_LOW
)
1417 mark
= zone
->pages_low
;
1419 mark
= zone
->pages_high
;
1420 if (!zone_watermark_ok(zone
, order
, mark
,
1421 classzone_idx
, alloc_flags
)) {
1422 if (!zone_reclaim_mode
||
1423 !zone_reclaim(zone
, gfp_mask
, order
))
1424 goto this_zone_full
;
1428 page
= buffered_rmqueue(zonelist
, zone
, order
, gfp_mask
);
1433 zlc_mark_zone_full(zonelist
, z
);
1435 if (NUMA_BUILD
&& !did_zlc_setup
) {
1436 /* we do zlc_setup after the first zone is tried */
1437 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1441 } while (*(++z
) != NULL
);
1443 if (unlikely(NUMA_BUILD
&& page
== NULL
&& zlc_active
)) {
1444 /* Disable zlc cache for second zonelist scan */
1452 * This is the 'heart' of the zoned buddy allocator.
1454 struct page
* fastcall
1455 __alloc_pages(gfp_t gfp_mask
, unsigned int order
,
1456 struct zonelist
*zonelist
)
1458 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
1461 struct reclaim_state reclaim_state
;
1462 struct task_struct
*p
= current
;
1465 int did_some_progress
;
1467 might_sleep_if(wait
);
1469 if (should_fail_alloc_page(gfp_mask
, order
))
1473 z
= zonelist
->zones
; /* the list of zones suitable for gfp_mask */
1475 if (unlikely(*z
== NULL
)) {
1477 * Happens if we have an empty zonelist as a result of
1478 * GFP_THISNODE being used on a memoryless node
1483 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, order
,
1484 zonelist
, ALLOC_WMARK_LOW
|ALLOC_CPUSET
);
1489 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
1490 * __GFP_NOWARN set) should not cause reclaim since the subsystem
1491 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
1492 * using a larger set of nodes after it has established that the
1493 * allowed per node queues are empty and that nodes are
1496 if (NUMA_BUILD
&& (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
1499 for (z
= zonelist
->zones
; *z
; z
++)
1500 wakeup_kswapd(*z
, order
);
1503 * OK, we're below the kswapd watermark and have kicked background
1504 * reclaim. Now things get more complex, so set up alloc_flags according
1505 * to how we want to proceed.
1507 * The caller may dip into page reserves a bit more if the caller
1508 * cannot run direct reclaim, or if the caller has realtime scheduling
1509 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
1510 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1512 alloc_flags
= ALLOC_WMARK_MIN
;
1513 if ((unlikely(rt_task(p
)) && !in_interrupt()) || !wait
)
1514 alloc_flags
|= ALLOC_HARDER
;
1515 if (gfp_mask
& __GFP_HIGH
)
1516 alloc_flags
|= ALLOC_HIGH
;
1518 alloc_flags
|= ALLOC_CPUSET
;
1521 * Go through the zonelist again. Let __GFP_HIGH and allocations
1522 * coming from realtime tasks go deeper into reserves.
1524 * This is the last chance, in general, before the goto nopage.
1525 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1526 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1528 page
= get_page_from_freelist(gfp_mask
, order
, zonelist
, alloc_flags
);
1532 /* This allocation should allow future memory freeing. */
1535 if (((p
->flags
& PF_MEMALLOC
) || unlikely(test_thread_flag(TIF_MEMDIE
)))
1536 && !in_interrupt()) {
1537 if (!(gfp_mask
& __GFP_NOMEMALLOC
)) {
1539 /* go through the zonelist yet again, ignoring mins */
1540 page
= get_page_from_freelist(gfp_mask
, order
,
1541 zonelist
, ALLOC_NO_WATERMARKS
);
1544 if (gfp_mask
& __GFP_NOFAIL
) {
1545 congestion_wait(WRITE
, HZ
/50);
1552 /* Atomic allocations - we can't balance anything */
1558 /* We now go into synchronous reclaim */
1559 cpuset_memory_pressure_bump();
1560 p
->flags
|= PF_MEMALLOC
;
1561 reclaim_state
.reclaimed_slab
= 0;
1562 p
->reclaim_state
= &reclaim_state
;
1564 did_some_progress
= try_to_free_pages(zonelist
->zones
, order
, gfp_mask
);
1566 p
->reclaim_state
= NULL
;
1567 p
->flags
&= ~PF_MEMALLOC
;
1574 if (likely(did_some_progress
)) {
1575 page
= get_page_from_freelist(gfp_mask
, order
,
1576 zonelist
, alloc_flags
);
1579 } else if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
1580 if (!try_set_zone_oom(zonelist
)) {
1581 schedule_timeout_uninterruptible(1);
1586 * Go through the zonelist yet one more time, keep
1587 * very high watermark here, this is only to catch
1588 * a parallel oom killing, we must fail if we're still
1589 * under heavy pressure.
1591 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, order
,
1592 zonelist
, ALLOC_WMARK_HIGH
|ALLOC_CPUSET
);
1594 clear_zonelist_oom(zonelist
);
1598 /* The OOM killer will not help higher order allocs so fail */
1599 if (order
> PAGE_ALLOC_COSTLY_ORDER
) {
1600 clear_zonelist_oom(zonelist
);
1604 out_of_memory(zonelist
, gfp_mask
, order
);
1605 clear_zonelist_oom(zonelist
);
1610 * Don't let big-order allocations loop unless the caller explicitly
1611 * requests that. Wait for some write requests to complete then retry.
1613 * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order
1614 * <= 3, but that may not be true in other implementations.
1617 if (!(gfp_mask
& __GFP_NORETRY
)) {
1618 if ((order
<= PAGE_ALLOC_COSTLY_ORDER
) ||
1619 (gfp_mask
& __GFP_REPEAT
))
1621 if (gfp_mask
& __GFP_NOFAIL
)
1625 congestion_wait(WRITE
, HZ
/50);
1630 if (!(gfp_mask
& __GFP_NOWARN
) && printk_ratelimit()) {
1631 printk(KERN_WARNING
"%s: page allocation failure."
1632 " order:%d, mode:0x%x\n",
1633 p
->comm
, order
, gfp_mask
);
1641 EXPORT_SYMBOL(__alloc_pages
);
1644 * Common helper functions.
1646 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
1649 page
= alloc_pages(gfp_mask
, order
);
1652 return (unsigned long) page_address(page
);
1655 EXPORT_SYMBOL(__get_free_pages
);
1657 unsigned long get_zeroed_page(gfp_t gfp_mask
)
1662 * get_zeroed_page() returns a 32-bit address, which cannot represent
1665 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
1667 page
= alloc_pages(gfp_mask
| __GFP_ZERO
, 0);
1669 return (unsigned long) page_address(page
);
1673 EXPORT_SYMBOL(get_zeroed_page
);
1675 void __pagevec_free(struct pagevec
*pvec
)
1677 int i
= pagevec_count(pvec
);
1680 free_hot_cold_page(pvec
->pages
[i
], pvec
->cold
);
1683 void __free_pages(struct page
*page
, unsigned int order
)
1685 if (put_page_testzero(page
)) {
1687 free_hot_page(page
);
1689 __free_pages_ok(page
, order
);
1693 EXPORT_SYMBOL(__free_pages
);
1695 void free_pages(unsigned long addr
, unsigned int order
)
1698 VM_BUG_ON(!virt_addr_valid((void *)addr
));
1699 __free_pages(virt_to_page((void *)addr
), order
);
1703 EXPORT_SYMBOL(free_pages
);
1705 static unsigned int nr_free_zone_pages(int offset
)
1707 /* Just pick one node, since fallback list is circular */
1708 pg_data_t
*pgdat
= NODE_DATA(numa_node_id());
1709 unsigned int sum
= 0;
1711 struct zonelist
*zonelist
= pgdat
->node_zonelists
+ offset
;
1712 struct zone
**zonep
= zonelist
->zones
;
1715 for (zone
= *zonep
++; zone
; zone
= *zonep
++) {
1716 unsigned long size
= zone
->present_pages
;
1717 unsigned long high
= zone
->pages_high
;
1726 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
1728 unsigned int nr_free_buffer_pages(void)
1730 return nr_free_zone_pages(gfp_zone(GFP_USER
));
1732 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
1735 * Amount of free RAM allocatable within all zones
1737 unsigned int nr_free_pagecache_pages(void)
1739 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
1742 static inline void show_node(struct zone
*zone
)
1745 printk("Node %d ", zone_to_nid(zone
));
1748 void si_meminfo(struct sysinfo
*val
)
1750 val
->totalram
= totalram_pages
;
1752 val
->freeram
= global_page_state(NR_FREE_PAGES
);
1753 val
->bufferram
= nr_blockdev_pages();
1754 val
->totalhigh
= totalhigh_pages
;
1755 val
->freehigh
= nr_free_highpages();
1756 val
->mem_unit
= PAGE_SIZE
;
1759 EXPORT_SYMBOL(si_meminfo
);
1762 void si_meminfo_node(struct sysinfo
*val
, int nid
)
1764 pg_data_t
*pgdat
= NODE_DATA(nid
);
1766 val
->totalram
= pgdat
->node_present_pages
;
1767 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
1768 #ifdef CONFIG_HIGHMEM
1769 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
1770 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
1776 val
->mem_unit
= PAGE_SIZE
;
1780 #define K(x) ((x) << (PAGE_SHIFT-10))
1783 * Show free area list (used inside shift_scroll-lock stuff)
1784 * We also calculate the percentage fragmentation. We do this by counting the
1785 * memory on each free list with the exception of the first item on the list.
1787 void show_free_areas(void)
1792 for_each_zone(zone
) {
1793 if (!populated_zone(zone
))
1797 printk("%s per-cpu:\n", zone
->name
);
1799 for_each_online_cpu(cpu
) {
1800 struct per_cpu_pageset
*pageset
;
1802 pageset
= zone_pcp(zone
, cpu
);
1804 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
1805 cpu
, pageset
->pcp
.high
,
1806 pageset
->pcp
.batch
, pageset
->pcp
.count
);
1810 printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu unstable:%lu\n"
1811 " free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n",
1812 global_page_state(NR_ACTIVE
),
1813 global_page_state(NR_INACTIVE
),
1814 global_page_state(NR_FILE_DIRTY
),
1815 global_page_state(NR_WRITEBACK
),
1816 global_page_state(NR_UNSTABLE_NFS
),
1817 global_page_state(NR_FREE_PAGES
),
1818 global_page_state(NR_SLAB_RECLAIMABLE
) +
1819 global_page_state(NR_SLAB_UNRECLAIMABLE
),
1820 global_page_state(NR_FILE_MAPPED
),
1821 global_page_state(NR_PAGETABLE
),
1822 global_page_state(NR_BOUNCE
));
1824 for_each_zone(zone
) {
1827 if (!populated_zone(zone
))
1839 " pages_scanned:%lu"
1840 " all_unreclaimable? %s"
1843 K(zone_page_state(zone
, NR_FREE_PAGES
)),
1846 K(zone
->pages_high
),
1847 K(zone_page_state(zone
, NR_ACTIVE
)),
1848 K(zone_page_state(zone
, NR_INACTIVE
)),
1849 K(zone
->present_pages
),
1850 zone
->pages_scanned
,
1851 (zone_is_all_unreclaimable(zone
) ? "yes" : "no")
1853 printk("lowmem_reserve[]:");
1854 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
1855 printk(" %lu", zone
->lowmem_reserve
[i
]);
1859 for_each_zone(zone
) {
1860 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
1862 if (!populated_zone(zone
))
1866 printk("%s: ", zone
->name
);
1868 spin_lock_irqsave(&zone
->lock
, flags
);
1869 for (order
= 0; order
< MAX_ORDER
; order
++) {
1870 nr
[order
] = zone
->free_area
[order
].nr_free
;
1871 total
+= nr
[order
] << order
;
1873 spin_unlock_irqrestore(&zone
->lock
, flags
);
1874 for (order
= 0; order
< MAX_ORDER
; order
++)
1875 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
1876 printk("= %lukB\n", K(total
));
1879 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
1881 show_swap_cache_info();
1885 * Builds allocation fallback zone lists.
1887 * Add all populated zones of a node to the zonelist.
1889 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
1890 int nr_zones
, enum zone_type zone_type
)
1894 BUG_ON(zone_type
>= MAX_NR_ZONES
);
1899 zone
= pgdat
->node_zones
+ zone_type
;
1900 if (populated_zone(zone
)) {
1901 zonelist
->zones
[nr_zones
++] = zone
;
1902 check_highest_zone(zone_type
);
1905 } while (zone_type
);
1912 * 0 = automatic detection of better ordering.
1913 * 1 = order by ([node] distance, -zonetype)
1914 * 2 = order by (-zonetype, [node] distance)
1916 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
1917 * the same zonelist. So only NUMA can configure this param.
1919 #define ZONELIST_ORDER_DEFAULT 0
1920 #define ZONELIST_ORDER_NODE 1
1921 #define ZONELIST_ORDER_ZONE 2
1923 /* zonelist order in the kernel.
1924 * set_zonelist_order() will set this to NODE or ZONE.
1926 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
1927 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
1931 /* The value user specified ....changed by config */
1932 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
1933 /* string for sysctl */
1934 #define NUMA_ZONELIST_ORDER_LEN 16
1935 char numa_zonelist_order
[16] = "default";
1938 * interface for configure zonelist ordering.
1939 * command line option "numa_zonelist_order"
1940 * = "[dD]efault - default, automatic configuration.
1941 * = "[nN]ode - order by node locality, then by zone within node
1942 * = "[zZ]one - order by zone, then by locality within zone
1945 static int __parse_numa_zonelist_order(char *s
)
1947 if (*s
== 'd' || *s
== 'D') {
1948 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
1949 } else if (*s
== 'n' || *s
== 'N') {
1950 user_zonelist_order
= ZONELIST_ORDER_NODE
;
1951 } else if (*s
== 'z' || *s
== 'Z') {
1952 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
1955 "Ignoring invalid numa_zonelist_order value: "
1962 static __init
int setup_numa_zonelist_order(char *s
)
1965 return __parse_numa_zonelist_order(s
);
1968 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
1971 * sysctl handler for numa_zonelist_order
1973 int numa_zonelist_order_handler(ctl_table
*table
, int write
,
1974 struct file
*file
, void __user
*buffer
, size_t *length
,
1977 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
1981 strncpy(saved_string
, (char*)table
->data
,
1982 NUMA_ZONELIST_ORDER_LEN
);
1983 ret
= proc_dostring(table
, write
, file
, buffer
, length
, ppos
);
1987 int oldval
= user_zonelist_order
;
1988 if (__parse_numa_zonelist_order((char*)table
->data
)) {
1990 * bogus value. restore saved string
1992 strncpy((char*)table
->data
, saved_string
,
1993 NUMA_ZONELIST_ORDER_LEN
);
1994 user_zonelist_order
= oldval
;
1995 } else if (oldval
!= user_zonelist_order
)
1996 build_all_zonelists();
2002 #define MAX_NODE_LOAD (num_online_nodes())
2003 static int node_load
[MAX_NUMNODES
];
2006 * find_next_best_node - find the next node that should appear in a given node's fallback list
2007 * @node: node whose fallback list we're appending
2008 * @used_node_mask: nodemask_t of already used nodes
2010 * We use a number of factors to determine which is the next node that should
2011 * appear on a given node's fallback list. The node should not have appeared
2012 * already in @node's fallback list, and it should be the next closest node
2013 * according to the distance array (which contains arbitrary distance values
2014 * from each node to each node in the system), and should also prefer nodes
2015 * with no CPUs, since presumably they'll have very little allocation pressure
2016 * on them otherwise.
2017 * It returns -1 if no node is found.
2019 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
2022 int min_val
= INT_MAX
;
2025 /* Use the local node if we haven't already */
2026 if (!node_isset(node
, *used_node_mask
)) {
2027 node_set(node
, *used_node_mask
);
2031 for_each_node_state(n
, N_HIGH_MEMORY
) {
2034 /* Don't want a node to appear more than once */
2035 if (node_isset(n
, *used_node_mask
))
2038 /* Use the distance array to find the distance */
2039 val
= node_distance(node
, n
);
2041 /* Penalize nodes under us ("prefer the next node") */
2044 /* Give preference to headless and unused nodes */
2045 tmp
= node_to_cpumask(n
);
2046 if (!cpus_empty(tmp
))
2047 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
2049 /* Slight preference for less loaded node */
2050 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
2051 val
+= node_load
[n
];
2053 if (val
< min_val
) {
2060 node_set(best_node
, *used_node_mask
);
2067 * Build zonelists ordered by node and zones within node.
2068 * This results in maximum locality--normal zone overflows into local
2069 * DMA zone, if any--but risks exhausting DMA zone.
2071 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
2075 struct zonelist
*zonelist
;
2077 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
2078 zonelist
= pgdat
->node_zonelists
+ i
;
2079 for (j
= 0; zonelist
->zones
[j
] != NULL
; j
++)
2081 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
, i
);
2082 zonelist
->zones
[j
] = NULL
;
2087 * Build gfp_thisnode zonelists
2089 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
2093 struct zonelist
*zonelist
;
2095 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
2096 zonelist
= pgdat
->node_zonelists
+ MAX_NR_ZONES
+ i
;
2097 j
= build_zonelists_node(pgdat
, zonelist
, 0, i
);
2098 zonelist
->zones
[j
] = NULL
;
2103 * Build zonelists ordered by zone and nodes within zones.
2104 * This results in conserving DMA zone[s] until all Normal memory is
2105 * exhausted, but results in overflowing to remote node while memory
2106 * may still exist in local DMA zone.
2108 static int node_order
[MAX_NUMNODES
];
2110 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
2114 int zone_type
; /* needs to be signed */
2116 struct zonelist
*zonelist
;
2118 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
2119 zonelist
= pgdat
->node_zonelists
+ i
;
2121 for (zone_type
= i
; zone_type
>= 0; zone_type
--) {
2122 for (j
= 0; j
< nr_nodes
; j
++) {
2123 node
= node_order
[j
];
2124 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
2125 if (populated_zone(z
)) {
2126 zonelist
->zones
[pos
++] = z
;
2127 check_highest_zone(zone_type
);
2131 zonelist
->zones
[pos
] = NULL
;
2135 static int default_zonelist_order(void)
2138 unsigned long low_kmem_size
,total_size
;
2142 * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem.
2143 * If they are really small and used heavily, the system can fall
2144 * into OOM very easily.
2145 * This function detect ZONE_DMA/DMA32 size and confgigures zone order.
2147 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
2150 for_each_online_node(nid
) {
2151 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2152 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2153 if (populated_zone(z
)) {
2154 if (zone_type
< ZONE_NORMAL
)
2155 low_kmem_size
+= z
->present_pages
;
2156 total_size
+= z
->present_pages
;
2160 if (!low_kmem_size
|| /* there are no DMA area. */
2161 low_kmem_size
> total_size
/2) /* DMA/DMA32 is big. */
2162 return ZONELIST_ORDER_NODE
;
2164 * look into each node's config.
2165 * If there is a node whose DMA/DMA32 memory is very big area on
2166 * local memory, NODE_ORDER may be suitable.
2168 average_size
= total_size
/
2169 (nodes_weight(node_states
[N_HIGH_MEMORY
]) + 1);
2170 for_each_online_node(nid
) {
2173 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2174 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2175 if (populated_zone(z
)) {
2176 if (zone_type
< ZONE_NORMAL
)
2177 low_kmem_size
+= z
->present_pages
;
2178 total_size
+= z
->present_pages
;
2181 if (low_kmem_size
&&
2182 total_size
> average_size
&& /* ignore small node */
2183 low_kmem_size
> total_size
* 70/100)
2184 return ZONELIST_ORDER_NODE
;
2186 return ZONELIST_ORDER_ZONE
;
2189 static void set_zonelist_order(void)
2191 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
2192 current_zonelist_order
= default_zonelist_order();
2194 current_zonelist_order
= user_zonelist_order
;
2197 static void build_zonelists(pg_data_t
*pgdat
)
2201 nodemask_t used_mask
;
2202 int local_node
, prev_node
;
2203 struct zonelist
*zonelist
;
2204 int order
= current_zonelist_order
;
2206 /* initialize zonelists */
2207 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
2208 zonelist
= pgdat
->node_zonelists
+ i
;
2209 zonelist
->zones
[0] = NULL
;
2212 /* NUMA-aware ordering of nodes */
2213 local_node
= pgdat
->node_id
;
2214 load
= num_online_nodes();
2215 prev_node
= local_node
;
2216 nodes_clear(used_mask
);
2218 memset(node_load
, 0, sizeof(node_load
));
2219 memset(node_order
, 0, sizeof(node_order
));
2222 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
2223 int distance
= node_distance(local_node
, node
);
2226 * If another node is sufficiently far away then it is better
2227 * to reclaim pages in a zone before going off node.
2229 if (distance
> RECLAIM_DISTANCE
)
2230 zone_reclaim_mode
= 1;
2233 * We don't want to pressure a particular node.
2234 * So adding penalty to the first node in same
2235 * distance group to make it round-robin.
2237 if (distance
!= node_distance(local_node
, prev_node
))
2238 node_load
[node
] = load
;
2242 if (order
== ZONELIST_ORDER_NODE
)
2243 build_zonelists_in_node_order(pgdat
, node
);
2245 node_order
[j
++] = node
; /* remember order */
2248 if (order
== ZONELIST_ORDER_ZONE
) {
2249 /* calculate node order -- i.e., DMA last! */
2250 build_zonelists_in_zone_order(pgdat
, j
);
2253 build_thisnode_zonelists(pgdat
);
2256 /* Construct the zonelist performance cache - see further mmzone.h */
2257 static void build_zonelist_cache(pg_data_t
*pgdat
)
2261 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
2262 struct zonelist
*zonelist
;
2263 struct zonelist_cache
*zlc
;
2266 zonelist
= pgdat
->node_zonelists
+ i
;
2267 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
2268 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
2269 for (z
= zonelist
->zones
; *z
; z
++)
2270 zlc
->z_to_n
[z
- zonelist
->zones
] = zone_to_nid(*z
);
2275 #else /* CONFIG_NUMA */
2277 static void set_zonelist_order(void)
2279 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
2282 static void build_zonelists(pg_data_t
*pgdat
)
2284 int node
, local_node
;
2287 local_node
= pgdat
->node_id
;
2288 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
2289 struct zonelist
*zonelist
;
2291 zonelist
= pgdat
->node_zonelists
+ i
;
2293 j
= build_zonelists_node(pgdat
, zonelist
, 0, i
);
2295 * Now we build the zonelist so that it contains the zones
2296 * of all the other nodes.
2297 * We don't want to pressure a particular node, so when
2298 * building the zones for node N, we make sure that the
2299 * zones coming right after the local ones are those from
2300 * node N+1 (modulo N)
2302 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
2303 if (!node_online(node
))
2305 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
, i
);
2307 for (node
= 0; node
< local_node
; node
++) {
2308 if (!node_online(node
))
2310 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
, i
);
2313 zonelist
->zones
[j
] = NULL
;
2317 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2318 static void build_zonelist_cache(pg_data_t
*pgdat
)
2322 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
2323 pgdat
->node_zonelists
[i
].zlcache_ptr
= NULL
;
2326 #endif /* CONFIG_NUMA */
2328 /* return values int ....just for stop_machine_run() */
2329 static int __build_all_zonelists(void *dummy
)
2333 for_each_online_node(nid
) {
2334 pg_data_t
*pgdat
= NODE_DATA(nid
);
2336 build_zonelists(pgdat
);
2337 build_zonelist_cache(pgdat
);
2342 void build_all_zonelists(void)
2344 set_zonelist_order();
2346 if (system_state
== SYSTEM_BOOTING
) {
2347 __build_all_zonelists(NULL
);
2348 cpuset_init_current_mems_allowed();
2350 /* we have to stop all cpus to guarantee there is no user
2352 stop_machine_run(__build_all_zonelists
, NULL
, NR_CPUS
);
2353 /* cpuset refresh routine should be here */
2355 vm_total_pages
= nr_free_pagecache_pages();
2357 * Disable grouping by mobility if the number of pages in the
2358 * system is too low to allow the mechanism to work. It would be
2359 * more accurate, but expensive to check per-zone. This check is
2360 * made on memory-hotadd so a system can start with mobility
2361 * disabled and enable it later
2363 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
2364 page_group_by_mobility_disabled
= 1;
2366 page_group_by_mobility_disabled
= 0;
2368 printk("Built %i zonelists in %s order, mobility grouping %s. "
2369 "Total pages: %ld\n",
2371 zonelist_order_name
[current_zonelist_order
],
2372 page_group_by_mobility_disabled
? "off" : "on",
2375 printk("Policy zone: %s\n", zone_names
[policy_zone
]);
2380 * Helper functions to size the waitqueue hash table.
2381 * Essentially these want to choose hash table sizes sufficiently
2382 * large so that collisions trying to wait on pages are rare.
2383 * But in fact, the number of active page waitqueues on typical
2384 * systems is ridiculously low, less than 200. So this is even
2385 * conservative, even though it seems large.
2387 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
2388 * waitqueues, i.e. the size of the waitq table given the number of pages.
2390 #define PAGES_PER_WAITQUEUE 256
2392 #ifndef CONFIG_MEMORY_HOTPLUG
2393 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
2395 unsigned long size
= 1;
2397 pages
/= PAGES_PER_WAITQUEUE
;
2399 while (size
< pages
)
2403 * Once we have dozens or even hundreds of threads sleeping
2404 * on IO we've got bigger problems than wait queue collision.
2405 * Limit the size of the wait table to a reasonable size.
2407 size
= min(size
, 4096UL);
2409 return max(size
, 4UL);
2413 * A zone's size might be changed by hot-add, so it is not possible to determine
2414 * a suitable size for its wait_table. So we use the maximum size now.
2416 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
2418 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
2419 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
2420 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
2422 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
2423 * or more by the traditional way. (See above). It equals:
2425 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
2426 * ia64(16K page size) : = ( 8G + 4M)byte.
2427 * powerpc (64K page size) : = (32G +16M)byte.
2429 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
2436 * This is an integer logarithm so that shifts can be used later
2437 * to extract the more random high bits from the multiplicative
2438 * hash function before the remainder is taken.
2440 static inline unsigned long wait_table_bits(unsigned long size
)
2445 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
2448 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2449 * of blocks reserved is based on zone->pages_min. The memory within the
2450 * reserve will tend to store contiguous free pages. Setting min_free_kbytes
2451 * higher will lead to a bigger reserve which will get freed as contiguous
2452 * blocks as reclaim kicks in
2454 static void setup_zone_migrate_reserve(struct zone
*zone
)
2456 unsigned long start_pfn
, pfn
, end_pfn
;
2458 unsigned long reserve
, block_migratetype
;
2460 /* Get the start pfn, end pfn and the number of blocks to reserve */
2461 start_pfn
= zone
->zone_start_pfn
;
2462 end_pfn
= start_pfn
+ zone
->spanned_pages
;
2463 reserve
= roundup(zone
->pages_min
, pageblock_nr_pages
) >>
2466 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
2467 if (!pfn_valid(pfn
))
2469 page
= pfn_to_page(pfn
);
2471 /* Blocks with reserved pages will never free, skip them. */
2472 if (PageReserved(page
))
2475 block_migratetype
= get_pageblock_migratetype(page
);
2477 /* If this block is reserved, account for it */
2478 if (reserve
> 0 && block_migratetype
== MIGRATE_RESERVE
) {
2483 /* Suitable for reserving if this block is movable */
2484 if (reserve
> 0 && block_migratetype
== MIGRATE_MOVABLE
) {
2485 set_pageblock_migratetype(page
, MIGRATE_RESERVE
);
2486 move_freepages_block(zone
, page
, MIGRATE_RESERVE
);
2492 * If the reserve is met and this is a previous reserved block,
2495 if (block_migratetype
== MIGRATE_RESERVE
) {
2496 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
2497 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
2503 * Initially all pages are reserved - free ones are freed
2504 * up by free_all_bootmem() once the early boot process is
2505 * done. Non-atomic initialization, single-pass.
2507 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
2508 unsigned long start_pfn
, enum memmap_context context
)
2511 unsigned long end_pfn
= start_pfn
+ size
;
2514 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
2516 * There can be holes in boot-time mem_map[]s
2517 * handed to this function. They do not
2518 * exist on hotplugged memory.
2520 if (context
== MEMMAP_EARLY
) {
2521 if (!early_pfn_valid(pfn
))
2523 if (!early_pfn_in_nid(pfn
, nid
))
2526 page
= pfn_to_page(pfn
);
2527 set_page_links(page
, zone
, nid
, pfn
);
2528 init_page_count(page
);
2529 reset_page_mapcount(page
);
2530 page_assign_page_cgroup(page
, NULL
);
2531 SetPageReserved(page
);
2534 * Mark the block movable so that blocks are reserved for
2535 * movable at startup. This will force kernel allocations
2536 * to reserve their blocks rather than leaking throughout
2537 * the address space during boot when many long-lived
2538 * kernel allocations are made. Later some blocks near
2539 * the start are marked MIGRATE_RESERVE by
2540 * setup_zone_migrate_reserve()
2542 if ((pfn
& (pageblock_nr_pages
-1)))
2543 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
2545 INIT_LIST_HEAD(&page
->lru
);
2546 #ifdef WANT_PAGE_VIRTUAL
2547 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
2548 if (!is_highmem_idx(zone
))
2549 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
2554 static void __meminit
zone_init_free_lists(struct zone
*zone
)
2557 for_each_migratetype_order(order
, t
) {
2558 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
2559 zone
->free_area
[order
].nr_free
= 0;
2563 #ifndef __HAVE_ARCH_MEMMAP_INIT
2564 #define memmap_init(size, nid, zone, start_pfn) \
2565 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
2568 static int zone_batchsize(struct zone
*zone
)
2573 * The per-cpu-pages pools are set to around 1000th of the
2574 * size of the zone. But no more than 1/2 of a meg.
2576 * OK, so we don't know how big the cache is. So guess.
2578 batch
= zone
->present_pages
/ 1024;
2579 if (batch
* PAGE_SIZE
> 512 * 1024)
2580 batch
= (512 * 1024) / PAGE_SIZE
;
2581 batch
/= 4; /* We effectively *= 4 below */
2586 * Clamp the batch to a 2^n - 1 value. Having a power
2587 * of 2 value was found to be more likely to have
2588 * suboptimal cache aliasing properties in some cases.
2590 * For example if 2 tasks are alternately allocating
2591 * batches of pages, one task can end up with a lot
2592 * of pages of one half of the possible page colors
2593 * and the other with pages of the other colors.
2595 batch
= (1 << (fls(batch
+ batch
/2)-1)) - 1;
2600 inline void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
2602 struct per_cpu_pages
*pcp
;
2604 memset(p
, 0, sizeof(*p
));
2608 pcp
->high
= 6 * batch
;
2609 pcp
->batch
= max(1UL, 1 * batch
);
2610 INIT_LIST_HEAD(&pcp
->list
);
2614 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
2615 * to the value high for the pageset p.
2618 static void setup_pagelist_highmark(struct per_cpu_pageset
*p
,
2621 struct per_cpu_pages
*pcp
;
2625 pcp
->batch
= max(1UL, high
/4);
2626 if ((high
/4) > (PAGE_SHIFT
* 8))
2627 pcp
->batch
= PAGE_SHIFT
* 8;
2633 * Boot pageset table. One per cpu which is going to be used for all
2634 * zones and all nodes. The parameters will be set in such a way
2635 * that an item put on a list will immediately be handed over to
2636 * the buddy list. This is safe since pageset manipulation is done
2637 * with interrupts disabled.
2639 * Some NUMA counter updates may also be caught by the boot pagesets.
2641 * The boot_pagesets must be kept even after bootup is complete for
2642 * unused processors and/or zones. They do play a role for bootstrapping
2643 * hotplugged processors.
2645 * zoneinfo_show() and maybe other functions do
2646 * not check if the processor is online before following the pageset pointer.
2647 * Other parts of the kernel may not check if the zone is available.
2649 static struct per_cpu_pageset boot_pageset
[NR_CPUS
];
2652 * Dynamically allocate memory for the
2653 * per cpu pageset array in struct zone.
2655 static int __cpuinit
process_zones(int cpu
)
2657 struct zone
*zone
, *dzone
;
2658 int node
= cpu_to_node(cpu
);
2660 node_set_state(node
, N_CPU
); /* this node has a cpu */
2662 for_each_zone(zone
) {
2664 if (!populated_zone(zone
))
2667 zone_pcp(zone
, cpu
) = kmalloc_node(sizeof(struct per_cpu_pageset
),
2669 if (!zone_pcp(zone
, cpu
))
2672 setup_pageset(zone_pcp(zone
, cpu
), zone_batchsize(zone
));
2674 if (percpu_pagelist_fraction
)
2675 setup_pagelist_highmark(zone_pcp(zone
, cpu
),
2676 (zone
->present_pages
/ percpu_pagelist_fraction
));
2681 for_each_zone(dzone
) {
2682 if (!populated_zone(dzone
))
2686 kfree(zone_pcp(dzone
, cpu
));
2687 zone_pcp(dzone
, cpu
) = NULL
;
2692 static inline void free_zone_pagesets(int cpu
)
2696 for_each_zone(zone
) {
2697 struct per_cpu_pageset
*pset
= zone_pcp(zone
, cpu
);
2699 /* Free per_cpu_pageset if it is slab allocated */
2700 if (pset
!= &boot_pageset
[cpu
])
2702 zone_pcp(zone
, cpu
) = NULL
;
2706 static int __cpuinit
pageset_cpuup_callback(struct notifier_block
*nfb
,
2707 unsigned long action
,
2710 int cpu
= (long)hcpu
;
2711 int ret
= NOTIFY_OK
;
2714 case CPU_UP_PREPARE
:
2715 case CPU_UP_PREPARE_FROZEN
:
2716 if (process_zones(cpu
))
2719 case CPU_UP_CANCELED
:
2720 case CPU_UP_CANCELED_FROZEN
:
2722 case CPU_DEAD_FROZEN
:
2723 free_zone_pagesets(cpu
);
2731 static struct notifier_block __cpuinitdata pageset_notifier
=
2732 { &pageset_cpuup_callback
, NULL
, 0 };
2734 void __init
setup_per_cpu_pageset(void)
2738 /* Initialize per_cpu_pageset for cpu 0.
2739 * A cpuup callback will do this for every cpu
2740 * as it comes online
2742 err
= process_zones(smp_processor_id());
2744 register_cpu_notifier(&pageset_notifier
);
2749 static noinline __init_refok
2750 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
2753 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
2757 * The per-page waitqueue mechanism uses hashed waitqueues
2760 zone
->wait_table_hash_nr_entries
=
2761 wait_table_hash_nr_entries(zone_size_pages
);
2762 zone
->wait_table_bits
=
2763 wait_table_bits(zone
->wait_table_hash_nr_entries
);
2764 alloc_size
= zone
->wait_table_hash_nr_entries
2765 * sizeof(wait_queue_head_t
);
2767 if (system_state
== SYSTEM_BOOTING
) {
2768 zone
->wait_table
= (wait_queue_head_t
*)
2769 alloc_bootmem_node(pgdat
, alloc_size
);
2772 * This case means that a zone whose size was 0 gets new memory
2773 * via memory hot-add.
2774 * But it may be the case that a new node was hot-added. In
2775 * this case vmalloc() will not be able to use this new node's
2776 * memory - this wait_table must be initialized to use this new
2777 * node itself as well.
2778 * To use this new node's memory, further consideration will be
2781 zone
->wait_table
= vmalloc(alloc_size
);
2783 if (!zone
->wait_table
)
2786 for(i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
2787 init_waitqueue_head(zone
->wait_table
+ i
);
2792 static __meminit
void zone_pcp_init(struct zone
*zone
)
2795 unsigned long batch
= zone_batchsize(zone
);
2797 for (cpu
= 0; cpu
< NR_CPUS
; cpu
++) {
2799 /* Early boot. Slab allocator not functional yet */
2800 zone_pcp(zone
, cpu
) = &boot_pageset
[cpu
];
2801 setup_pageset(&boot_pageset
[cpu
],0);
2803 setup_pageset(zone_pcp(zone
,cpu
), batch
);
2806 if (zone
->present_pages
)
2807 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%lu\n",
2808 zone
->name
, zone
->present_pages
, batch
);
2811 __meminit
int init_currently_empty_zone(struct zone
*zone
,
2812 unsigned long zone_start_pfn
,
2814 enum memmap_context context
)
2816 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
2818 ret
= zone_wait_table_init(zone
, size
);
2821 pgdat
->nr_zones
= zone_idx(zone
) + 1;
2823 zone
->zone_start_pfn
= zone_start_pfn
;
2825 memmap_init(size
, pgdat
->node_id
, zone_idx(zone
), zone_start_pfn
);
2827 zone_init_free_lists(zone
);
2832 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
2834 * Basic iterator support. Return the first range of PFNs for a node
2835 * Note: nid == MAX_NUMNODES returns first region regardless of node
2837 static int __meminit
first_active_region_index_in_nid(int nid
)
2841 for (i
= 0; i
< nr_nodemap_entries
; i
++)
2842 if (nid
== MAX_NUMNODES
|| early_node_map
[i
].nid
== nid
)
2849 * Basic iterator support. Return the next active range of PFNs for a node
2850 * Note: nid == MAX_NUMNODES returns next region regardless of node
2852 static int __meminit
next_active_region_index_in_nid(int index
, int nid
)
2854 for (index
= index
+ 1; index
< nr_nodemap_entries
; index
++)
2855 if (nid
== MAX_NUMNODES
|| early_node_map
[index
].nid
== nid
)
2861 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
2863 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
2864 * Architectures may implement their own version but if add_active_range()
2865 * was used and there are no special requirements, this is a convenient
2868 int __meminit
early_pfn_to_nid(unsigned long pfn
)
2872 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
2873 unsigned long start_pfn
= early_node_map
[i
].start_pfn
;
2874 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
2876 if (start_pfn
<= pfn
&& pfn
< end_pfn
)
2877 return early_node_map
[i
].nid
;
2882 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
2884 /* Basic iterator support to walk early_node_map[] */
2885 #define for_each_active_range_index_in_nid(i, nid) \
2886 for (i = first_active_region_index_in_nid(nid); i != -1; \
2887 i = next_active_region_index_in_nid(i, nid))
2890 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
2891 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
2892 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
2894 * If an architecture guarantees that all ranges registered with
2895 * add_active_ranges() contain no holes and may be freed, this
2896 * this function may be used instead of calling free_bootmem() manually.
2898 void __init
free_bootmem_with_active_regions(int nid
,
2899 unsigned long max_low_pfn
)
2903 for_each_active_range_index_in_nid(i
, nid
) {
2904 unsigned long size_pages
= 0;
2905 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
2907 if (early_node_map
[i
].start_pfn
>= max_low_pfn
)
2910 if (end_pfn
> max_low_pfn
)
2911 end_pfn
= max_low_pfn
;
2913 size_pages
= end_pfn
- early_node_map
[i
].start_pfn
;
2914 free_bootmem_node(NODE_DATA(early_node_map
[i
].nid
),
2915 PFN_PHYS(early_node_map
[i
].start_pfn
),
2916 size_pages
<< PAGE_SHIFT
);
2921 * sparse_memory_present_with_active_regions - Call memory_present for each active range
2922 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
2924 * If an architecture guarantees that all ranges registered with
2925 * add_active_ranges() contain no holes and may be freed, this
2926 * function may be used instead of calling memory_present() manually.
2928 void __init
sparse_memory_present_with_active_regions(int nid
)
2932 for_each_active_range_index_in_nid(i
, nid
)
2933 memory_present(early_node_map
[i
].nid
,
2934 early_node_map
[i
].start_pfn
,
2935 early_node_map
[i
].end_pfn
);
2939 * push_node_boundaries - Push node boundaries to at least the requested boundary
2940 * @nid: The nid of the node to push the boundary for
2941 * @start_pfn: The start pfn of the node
2942 * @end_pfn: The end pfn of the node
2944 * In reserve-based hot-add, mem_map is allocated that is unused until hotadd
2945 * time. Specifically, on x86_64, SRAT will report ranges that can potentially
2946 * be hotplugged even though no physical memory exists. This function allows
2947 * an arch to push out the node boundaries so mem_map is allocated that can
2950 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
2951 void __init
push_node_boundaries(unsigned int nid
,
2952 unsigned long start_pfn
, unsigned long end_pfn
)
2954 printk(KERN_DEBUG
"Entering push_node_boundaries(%u, %lu, %lu)\n",
2955 nid
, start_pfn
, end_pfn
);
2957 /* Initialise the boundary for this node if necessary */
2958 if (node_boundary_end_pfn
[nid
] == 0)
2959 node_boundary_start_pfn
[nid
] = -1UL;
2961 /* Update the boundaries */
2962 if (node_boundary_start_pfn
[nid
] > start_pfn
)
2963 node_boundary_start_pfn
[nid
] = start_pfn
;
2964 if (node_boundary_end_pfn
[nid
] < end_pfn
)
2965 node_boundary_end_pfn
[nid
] = end_pfn
;
2968 /* If necessary, push the node boundary out for reserve hotadd */
2969 static void __meminit
account_node_boundary(unsigned int nid
,
2970 unsigned long *start_pfn
, unsigned long *end_pfn
)
2972 printk(KERN_DEBUG
"Entering account_node_boundary(%u, %lu, %lu)\n",
2973 nid
, *start_pfn
, *end_pfn
);
2975 /* Return if boundary information has not been provided */
2976 if (node_boundary_end_pfn
[nid
] == 0)
2979 /* Check the boundaries and update if necessary */
2980 if (node_boundary_start_pfn
[nid
] < *start_pfn
)
2981 *start_pfn
= node_boundary_start_pfn
[nid
];
2982 if (node_boundary_end_pfn
[nid
] > *end_pfn
)
2983 *end_pfn
= node_boundary_end_pfn
[nid
];
2986 void __init
push_node_boundaries(unsigned int nid
,
2987 unsigned long start_pfn
, unsigned long end_pfn
) {}
2989 static void __meminit
account_node_boundary(unsigned int nid
,
2990 unsigned long *start_pfn
, unsigned long *end_pfn
) {}
2995 * get_pfn_range_for_nid - Return the start and end page frames for a node
2996 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
2997 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
2998 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
3000 * It returns the start and end page frame of a node based on information
3001 * provided by an arch calling add_active_range(). If called for a node
3002 * with no available memory, a warning is printed and the start and end
3005 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
3006 unsigned long *start_pfn
, unsigned long *end_pfn
)
3012 for_each_active_range_index_in_nid(i
, nid
) {
3013 *start_pfn
= min(*start_pfn
, early_node_map
[i
].start_pfn
);
3014 *end_pfn
= max(*end_pfn
, early_node_map
[i
].end_pfn
);
3017 if (*start_pfn
== -1UL)
3020 /* Push the node boundaries out if requested */
3021 account_node_boundary(nid
, start_pfn
, end_pfn
);
3025 * This finds a zone that can be used for ZONE_MOVABLE pages. The
3026 * assumption is made that zones within a node are ordered in monotonic
3027 * increasing memory addresses so that the "highest" populated zone is used
3029 void __init
find_usable_zone_for_movable(void)
3032 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
3033 if (zone_index
== ZONE_MOVABLE
)
3036 if (arch_zone_highest_possible_pfn
[zone_index
] >
3037 arch_zone_lowest_possible_pfn
[zone_index
])
3041 VM_BUG_ON(zone_index
== -1);
3042 movable_zone
= zone_index
;
3046 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
3047 * because it is sized independant of architecture. Unlike the other zones,
3048 * the starting point for ZONE_MOVABLE is not fixed. It may be different
3049 * in each node depending on the size of each node and how evenly kernelcore
3050 * is distributed. This helper function adjusts the zone ranges
3051 * provided by the architecture for a given node by using the end of the
3052 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
3053 * zones within a node are in order of monotonic increases memory addresses
3055 void __meminit
adjust_zone_range_for_zone_movable(int nid
,
3056 unsigned long zone_type
,
3057 unsigned long node_start_pfn
,
3058 unsigned long node_end_pfn
,
3059 unsigned long *zone_start_pfn
,
3060 unsigned long *zone_end_pfn
)
3062 /* Only adjust if ZONE_MOVABLE is on this node */
3063 if (zone_movable_pfn
[nid
]) {
3064 /* Size ZONE_MOVABLE */
3065 if (zone_type
== ZONE_MOVABLE
) {
3066 *zone_start_pfn
= zone_movable_pfn
[nid
];
3067 *zone_end_pfn
= min(node_end_pfn
,
3068 arch_zone_highest_possible_pfn
[movable_zone
]);
3070 /* Adjust for ZONE_MOVABLE starting within this range */
3071 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
3072 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
3073 *zone_end_pfn
= zone_movable_pfn
[nid
];
3075 /* Check if this whole range is within ZONE_MOVABLE */
3076 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
3077 *zone_start_pfn
= *zone_end_pfn
;
3082 * Return the number of pages a zone spans in a node, including holes
3083 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
3085 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3086 unsigned long zone_type
,
3087 unsigned long *ignored
)
3089 unsigned long node_start_pfn
, node_end_pfn
;
3090 unsigned long zone_start_pfn
, zone_end_pfn
;
3092 /* Get the start and end of the node and zone */
3093 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3094 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
3095 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
3096 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3097 node_start_pfn
, node_end_pfn
,
3098 &zone_start_pfn
, &zone_end_pfn
);
3100 /* Check that this node has pages within the zone's required range */
3101 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
3104 /* Move the zone boundaries inside the node if necessary */
3105 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
3106 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
3108 /* Return the spanned pages */
3109 return zone_end_pfn
- zone_start_pfn
;
3113 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
3114 * then all holes in the requested range will be accounted for.
3116 unsigned long __meminit
__absent_pages_in_range(int nid
,
3117 unsigned long range_start_pfn
,
3118 unsigned long range_end_pfn
)
3121 unsigned long prev_end_pfn
= 0, hole_pages
= 0;
3122 unsigned long start_pfn
;
3124 /* Find the end_pfn of the first active range of pfns in the node */
3125 i
= first_active_region_index_in_nid(nid
);
3129 prev_end_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3131 /* Account for ranges before physical memory on this node */
3132 if (early_node_map
[i
].start_pfn
> range_start_pfn
)
3133 hole_pages
= prev_end_pfn
- range_start_pfn
;
3135 /* Find all holes for the zone within the node */
3136 for (; i
!= -1; i
= next_active_region_index_in_nid(i
, nid
)) {
3138 /* No need to continue if prev_end_pfn is outside the zone */
3139 if (prev_end_pfn
>= range_end_pfn
)
3142 /* Make sure the end of the zone is not within the hole */
3143 start_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3144 prev_end_pfn
= max(prev_end_pfn
, range_start_pfn
);
3146 /* Update the hole size cound and move on */
3147 if (start_pfn
> range_start_pfn
) {
3148 BUG_ON(prev_end_pfn
> start_pfn
);
3149 hole_pages
+= start_pfn
- prev_end_pfn
;
3151 prev_end_pfn
= early_node_map
[i
].end_pfn
;
3154 /* Account for ranges past physical memory on this node */
3155 if (range_end_pfn
> prev_end_pfn
)
3156 hole_pages
+= range_end_pfn
-
3157 max(range_start_pfn
, prev_end_pfn
);
3163 * absent_pages_in_range - Return number of page frames in holes within a range
3164 * @start_pfn: The start PFN to start searching for holes
3165 * @end_pfn: The end PFN to stop searching for holes
3167 * It returns the number of pages frames in memory holes within a range.
3169 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
3170 unsigned long end_pfn
)
3172 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
3175 /* Return the number of page frames in holes in a zone on a node */
3176 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
3177 unsigned long zone_type
,
3178 unsigned long *ignored
)
3180 unsigned long node_start_pfn
, node_end_pfn
;
3181 unsigned long zone_start_pfn
, zone_end_pfn
;
3183 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3184 zone_start_pfn
= max(arch_zone_lowest_possible_pfn
[zone_type
],
3186 zone_end_pfn
= min(arch_zone_highest_possible_pfn
[zone_type
],
3189 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3190 node_start_pfn
, node_end_pfn
,
3191 &zone_start_pfn
, &zone_end_pfn
);
3192 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
3196 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3197 unsigned long zone_type
,
3198 unsigned long *zones_size
)
3200 return zones_size
[zone_type
];
3203 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
3204 unsigned long zone_type
,
3205 unsigned long *zholes_size
)
3210 return zholes_size
[zone_type
];
3215 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
3216 unsigned long *zones_size
, unsigned long *zholes_size
)
3218 unsigned long realtotalpages
, totalpages
= 0;
3221 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3222 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
3224 pgdat
->node_spanned_pages
= totalpages
;
3226 realtotalpages
= totalpages
;
3227 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3229 zone_absent_pages_in_node(pgdat
->node_id
, i
,
3231 pgdat
->node_present_pages
= realtotalpages
;
3232 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
3236 #ifndef CONFIG_SPARSEMEM
3238 * Calculate the size of the zone->blockflags rounded to an unsigned long
3239 * Start by making sure zonesize is a multiple of pageblock_order by rounding
3240 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
3241 * round what is now in bits to nearest long in bits, then return it in
3244 static unsigned long __init
usemap_size(unsigned long zonesize
)
3246 unsigned long usemapsize
;
3248 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
3249 usemapsize
= usemapsize
>> pageblock_order
;
3250 usemapsize
*= NR_PAGEBLOCK_BITS
;
3251 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
3253 return usemapsize
/ 8;
3256 static void __init
setup_usemap(struct pglist_data
*pgdat
,
3257 struct zone
*zone
, unsigned long zonesize
)
3259 unsigned long usemapsize
= usemap_size(zonesize
);
3260 zone
->pageblock_flags
= NULL
;
3262 zone
->pageblock_flags
= alloc_bootmem_node(pgdat
, usemapsize
);
3263 memset(zone
->pageblock_flags
, 0, usemapsize
);
3267 static void inline setup_usemap(struct pglist_data
*pgdat
,
3268 struct zone
*zone
, unsigned long zonesize
) {}
3269 #endif /* CONFIG_SPARSEMEM */
3271 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3273 /* Return a sensible default order for the pageblock size. */
3274 static inline int pageblock_default_order(void)
3276 if (HPAGE_SHIFT
> PAGE_SHIFT
)
3277 return HUGETLB_PAGE_ORDER
;
3282 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
3283 static inline void __init
set_pageblock_order(unsigned int order
)
3285 /* Check that pageblock_nr_pages has not already been setup */
3286 if (pageblock_order
)
3290 * Assume the largest contiguous order of interest is a huge page.
3291 * This value may be variable depending on boot parameters on IA64
3293 pageblock_order
= order
;
3295 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3298 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
3299 * and pageblock_default_order() are unused as pageblock_order is set
3300 * at compile-time. See include/linux/pageblock-flags.h for the values of
3301 * pageblock_order based on the kernel config
3303 static inline int pageblock_default_order(unsigned int order
)
3307 #define set_pageblock_order(x) do {} while (0)
3309 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3312 * Set up the zone data structures:
3313 * - mark all pages reserved
3314 * - mark all memory queues empty
3315 * - clear the memory bitmaps
3317 static void __meminit
free_area_init_core(struct pglist_data
*pgdat
,
3318 unsigned long *zones_size
, unsigned long *zholes_size
)
3321 int nid
= pgdat
->node_id
;
3322 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
3325 pgdat_resize_init(pgdat
);
3326 pgdat
->nr_zones
= 0;
3327 init_waitqueue_head(&pgdat
->kswapd_wait
);
3328 pgdat
->kswapd_max_order
= 0;
3330 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
3331 struct zone
*zone
= pgdat
->node_zones
+ j
;
3332 unsigned long size
, realsize
, memmap_pages
;
3334 size
= zone_spanned_pages_in_node(nid
, j
, zones_size
);
3335 realsize
= size
- zone_absent_pages_in_node(nid
, j
,
3339 * Adjust realsize so that it accounts for how much memory
3340 * is used by this zone for memmap. This affects the watermark
3341 * and per-cpu initialisations
3343 memmap_pages
= (size
* sizeof(struct page
)) >> PAGE_SHIFT
;
3344 if (realsize
>= memmap_pages
) {
3345 realsize
-= memmap_pages
;
3347 " %s zone: %lu pages used for memmap\n",
3348 zone_names
[j
], memmap_pages
);
3351 " %s zone: %lu pages exceeds realsize %lu\n",
3352 zone_names
[j
], memmap_pages
, realsize
);
3354 /* Account for reserved pages */
3355 if (j
== 0 && realsize
> dma_reserve
) {
3356 realsize
-= dma_reserve
;
3357 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
3358 zone_names
[0], dma_reserve
);
3361 if (!is_highmem_idx(j
))
3362 nr_kernel_pages
+= realsize
;
3363 nr_all_pages
+= realsize
;
3365 zone
->spanned_pages
= size
;
3366 zone
->present_pages
= realsize
;
3369 zone
->min_unmapped_pages
= (realsize
*sysctl_min_unmapped_ratio
)
3371 zone
->min_slab_pages
= (realsize
* sysctl_min_slab_ratio
) / 100;
3373 zone
->name
= zone_names
[j
];
3374 spin_lock_init(&zone
->lock
);
3375 spin_lock_init(&zone
->lru_lock
);
3376 zone_seqlock_init(zone
);
3377 zone
->zone_pgdat
= pgdat
;
3379 zone
->prev_priority
= DEF_PRIORITY
;
3381 zone_pcp_init(zone
);
3382 INIT_LIST_HEAD(&zone
->active_list
);
3383 INIT_LIST_HEAD(&zone
->inactive_list
);
3384 zone
->nr_scan_active
= 0;
3385 zone
->nr_scan_inactive
= 0;
3386 zap_zone_vm_stats(zone
);
3391 set_pageblock_order(pageblock_default_order());
3392 setup_usemap(pgdat
, zone
, size
);
3393 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
3394 size
, MEMMAP_EARLY
);
3396 zone_start_pfn
+= size
;
3400 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
3402 /* Skip empty nodes */
3403 if (!pgdat
->node_spanned_pages
)
3406 #ifdef CONFIG_FLAT_NODE_MEM_MAP
3407 /* ia64 gets its own node_mem_map, before this, without bootmem */
3408 if (!pgdat
->node_mem_map
) {
3409 unsigned long size
, start
, end
;
3413 * The zone's endpoints aren't required to be MAX_ORDER
3414 * aligned but the node_mem_map endpoints must be in order
3415 * for the buddy allocator to function correctly.
3417 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
3418 end
= pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
3419 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
3420 size
= (end
- start
) * sizeof(struct page
);
3421 map
= alloc_remap(pgdat
->node_id
, size
);
3423 map
= alloc_bootmem_node(pgdat
, size
);
3424 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
3426 #ifndef CONFIG_NEED_MULTIPLE_NODES
3428 * With no DISCONTIG, the global mem_map is just set as node 0's
3430 if (pgdat
== NODE_DATA(0)) {
3431 mem_map
= NODE_DATA(0)->node_mem_map
;
3432 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3433 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
3434 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
3435 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
3438 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
3441 void __meminit
free_area_init_node(int nid
, struct pglist_data
*pgdat
,
3442 unsigned long *zones_size
, unsigned long node_start_pfn
,
3443 unsigned long *zholes_size
)
3445 pgdat
->node_id
= nid
;
3446 pgdat
->node_start_pfn
= node_start_pfn
;
3447 calculate_node_totalpages(pgdat
, zones_size
, zholes_size
);
3449 alloc_node_mem_map(pgdat
);
3451 free_area_init_core(pgdat
, zones_size
, zholes_size
);
3454 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3456 #if MAX_NUMNODES > 1
3458 * Figure out the number of possible node ids.
3460 static void __init
setup_nr_node_ids(void)
3463 unsigned int highest
= 0;
3465 for_each_node_mask(node
, node_possible_map
)
3467 nr_node_ids
= highest
+ 1;
3470 static inline void setup_nr_node_ids(void)
3476 * add_active_range - Register a range of PFNs backed by physical memory
3477 * @nid: The node ID the range resides on
3478 * @start_pfn: The start PFN of the available physical memory
3479 * @end_pfn: The end PFN of the available physical memory
3481 * These ranges are stored in an early_node_map[] and later used by
3482 * free_area_init_nodes() to calculate zone sizes and holes. If the
3483 * range spans a memory hole, it is up to the architecture to ensure
3484 * the memory is not freed by the bootmem allocator. If possible
3485 * the range being registered will be merged with existing ranges.
3487 void __init
add_active_range(unsigned int nid
, unsigned long start_pfn
,
3488 unsigned long end_pfn
)
3492 printk(KERN_DEBUG
"Entering add_active_range(%d, %lu, %lu) "
3493 "%d entries of %d used\n",
3494 nid
, start_pfn
, end_pfn
,
3495 nr_nodemap_entries
, MAX_ACTIVE_REGIONS
);
3497 /* Merge with existing active regions if possible */
3498 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
3499 if (early_node_map
[i
].nid
!= nid
)
3502 /* Skip if an existing region covers this new one */
3503 if (start_pfn
>= early_node_map
[i
].start_pfn
&&
3504 end_pfn
<= early_node_map
[i
].end_pfn
)
3507 /* Merge forward if suitable */
3508 if (start_pfn
<= early_node_map
[i
].end_pfn
&&
3509 end_pfn
> early_node_map
[i
].end_pfn
) {
3510 early_node_map
[i
].end_pfn
= end_pfn
;
3514 /* Merge backward if suitable */
3515 if (start_pfn
< early_node_map
[i
].end_pfn
&&
3516 end_pfn
>= early_node_map
[i
].start_pfn
) {
3517 early_node_map
[i
].start_pfn
= start_pfn
;
3522 /* Check that early_node_map is large enough */
3523 if (i
>= MAX_ACTIVE_REGIONS
) {
3524 printk(KERN_CRIT
"More than %d memory regions, truncating\n",
3525 MAX_ACTIVE_REGIONS
);
3529 early_node_map
[i
].nid
= nid
;
3530 early_node_map
[i
].start_pfn
= start_pfn
;
3531 early_node_map
[i
].end_pfn
= end_pfn
;
3532 nr_nodemap_entries
= i
+ 1;
3536 * shrink_active_range - Shrink an existing registered range of PFNs
3537 * @nid: The node id the range is on that should be shrunk
3538 * @old_end_pfn: The old end PFN of the range
3539 * @new_end_pfn: The new PFN of the range
3541 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
3542 * The map is kept at the end physical page range that has already been
3543 * registered with add_active_range(). This function allows an arch to shrink
3544 * an existing registered range.
3546 void __init
shrink_active_range(unsigned int nid
, unsigned long old_end_pfn
,
3547 unsigned long new_end_pfn
)
3551 /* Find the old active region end and shrink */
3552 for_each_active_range_index_in_nid(i
, nid
)
3553 if (early_node_map
[i
].end_pfn
== old_end_pfn
) {
3554 early_node_map
[i
].end_pfn
= new_end_pfn
;
3560 * remove_all_active_ranges - Remove all currently registered regions
3562 * During discovery, it may be found that a table like SRAT is invalid
3563 * and an alternative discovery method must be used. This function removes
3564 * all currently registered regions.
3566 void __init
remove_all_active_ranges(void)
3568 memset(early_node_map
, 0, sizeof(early_node_map
));
3569 nr_nodemap_entries
= 0;
3570 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
3571 memset(node_boundary_start_pfn
, 0, sizeof(node_boundary_start_pfn
));
3572 memset(node_boundary_end_pfn
, 0, sizeof(node_boundary_end_pfn
));
3573 #endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
3576 /* Compare two active node_active_regions */
3577 static int __init
cmp_node_active_region(const void *a
, const void *b
)
3579 struct node_active_region
*arange
= (struct node_active_region
*)a
;
3580 struct node_active_region
*brange
= (struct node_active_region
*)b
;
3582 /* Done this way to avoid overflows */
3583 if (arange
->start_pfn
> brange
->start_pfn
)
3585 if (arange
->start_pfn
< brange
->start_pfn
)
3591 /* sort the node_map by start_pfn */
3592 static void __init
sort_node_map(void)
3594 sort(early_node_map
, (size_t)nr_nodemap_entries
,
3595 sizeof(struct node_active_region
),
3596 cmp_node_active_region
, NULL
);
3599 /* Find the lowest pfn for a node */
3600 unsigned long __init
find_min_pfn_for_node(unsigned long nid
)
3603 unsigned long min_pfn
= ULONG_MAX
;
3605 /* Assuming a sorted map, the first range found has the starting pfn */
3606 for_each_active_range_index_in_nid(i
, nid
)
3607 min_pfn
= min(min_pfn
, early_node_map
[i
].start_pfn
);
3609 if (min_pfn
== ULONG_MAX
) {
3611 "Could not find start_pfn for node %lu\n", nid
);
3619 * find_min_pfn_with_active_regions - Find the minimum PFN registered
3621 * It returns the minimum PFN based on information provided via
3622 * add_active_range().
3624 unsigned long __init
find_min_pfn_with_active_regions(void)
3626 return find_min_pfn_for_node(MAX_NUMNODES
);
3630 * find_max_pfn_with_active_regions - Find the maximum PFN registered
3632 * It returns the maximum PFN based on information provided via
3633 * add_active_range().
3635 unsigned long __init
find_max_pfn_with_active_regions(void)
3638 unsigned long max_pfn
= 0;
3640 for (i
= 0; i
< nr_nodemap_entries
; i
++)
3641 max_pfn
= max(max_pfn
, early_node_map
[i
].end_pfn
);
3647 * early_calculate_totalpages()
3648 * Sum pages in active regions for movable zone.
3649 * Populate N_HIGH_MEMORY for calculating usable_nodes.
3651 static unsigned long __init
early_calculate_totalpages(void)
3654 unsigned long totalpages
= 0;
3656 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
3657 unsigned long pages
= early_node_map
[i
].end_pfn
-
3658 early_node_map
[i
].start_pfn
;
3659 totalpages
+= pages
;
3661 node_set_state(early_node_map
[i
].nid
, N_HIGH_MEMORY
);
3667 * Find the PFN the Movable zone begins in each node. Kernel memory
3668 * is spread evenly between nodes as long as the nodes have enough
3669 * memory. When they don't, some nodes will have more kernelcore than
3672 void __init
find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn
)
3675 unsigned long usable_startpfn
;
3676 unsigned long kernelcore_node
, kernelcore_remaining
;
3677 unsigned long totalpages
= early_calculate_totalpages();
3678 int usable_nodes
= nodes_weight(node_states
[N_HIGH_MEMORY
]);
3681 * If movablecore was specified, calculate what size of
3682 * kernelcore that corresponds so that memory usable for
3683 * any allocation type is evenly spread. If both kernelcore
3684 * and movablecore are specified, then the value of kernelcore
3685 * will be used for required_kernelcore if it's greater than
3686 * what movablecore would have allowed.
3688 if (required_movablecore
) {
3689 unsigned long corepages
;
3692 * Round-up so that ZONE_MOVABLE is at least as large as what
3693 * was requested by the user
3695 required_movablecore
=
3696 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
3697 corepages
= totalpages
- required_movablecore
;
3699 required_kernelcore
= max(required_kernelcore
, corepages
);
3702 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
3703 if (!required_kernelcore
)
3706 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
3707 find_usable_zone_for_movable();
3708 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
3711 /* Spread kernelcore memory as evenly as possible throughout nodes */
3712 kernelcore_node
= required_kernelcore
/ usable_nodes
;
3713 for_each_node_state(nid
, N_HIGH_MEMORY
) {
3715 * Recalculate kernelcore_node if the division per node
3716 * now exceeds what is necessary to satisfy the requested
3717 * amount of memory for the kernel
3719 if (required_kernelcore
< kernelcore_node
)
3720 kernelcore_node
= required_kernelcore
/ usable_nodes
;
3723 * As the map is walked, we track how much memory is usable
3724 * by the kernel using kernelcore_remaining. When it is
3725 * 0, the rest of the node is usable by ZONE_MOVABLE
3727 kernelcore_remaining
= kernelcore_node
;
3729 /* Go through each range of PFNs within this node */
3730 for_each_active_range_index_in_nid(i
, nid
) {
3731 unsigned long start_pfn
, end_pfn
;
3732 unsigned long size_pages
;
3734 start_pfn
= max(early_node_map
[i
].start_pfn
,
3735 zone_movable_pfn
[nid
]);
3736 end_pfn
= early_node_map
[i
].end_pfn
;
3737 if (start_pfn
>= end_pfn
)
3740 /* Account for what is only usable for kernelcore */
3741 if (start_pfn
< usable_startpfn
) {
3742 unsigned long kernel_pages
;
3743 kernel_pages
= min(end_pfn
, usable_startpfn
)
3746 kernelcore_remaining
-= min(kernel_pages
,
3747 kernelcore_remaining
);
3748 required_kernelcore
-= min(kernel_pages
,
3749 required_kernelcore
);
3751 /* Continue if range is now fully accounted */
3752 if (end_pfn
<= usable_startpfn
) {
3755 * Push zone_movable_pfn to the end so
3756 * that if we have to rebalance
3757 * kernelcore across nodes, we will
3758 * not double account here
3760 zone_movable_pfn
[nid
] = end_pfn
;
3763 start_pfn
= usable_startpfn
;
3767 * The usable PFN range for ZONE_MOVABLE is from
3768 * start_pfn->end_pfn. Calculate size_pages as the
3769 * number of pages used as kernelcore
3771 size_pages
= end_pfn
- start_pfn
;
3772 if (size_pages
> kernelcore_remaining
)
3773 size_pages
= kernelcore_remaining
;
3774 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
3777 * Some kernelcore has been met, update counts and
3778 * break if the kernelcore for this node has been
3781 required_kernelcore
-= min(required_kernelcore
,
3783 kernelcore_remaining
-= size_pages
;
3784 if (!kernelcore_remaining
)
3790 * If there is still required_kernelcore, we do another pass with one
3791 * less node in the count. This will push zone_movable_pfn[nid] further
3792 * along on the nodes that still have memory until kernelcore is
3796 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
3799 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
3800 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
3801 zone_movable_pfn
[nid
] =
3802 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
3805 /* Any regular memory on that node ? */
3806 static void check_for_regular_memory(pg_data_t
*pgdat
)
3808 #ifdef CONFIG_HIGHMEM
3809 enum zone_type zone_type
;
3811 for (zone_type
= 0; zone_type
<= ZONE_NORMAL
; zone_type
++) {
3812 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
3813 if (zone
->present_pages
)
3814 node_set_state(zone_to_nid(zone
), N_NORMAL_MEMORY
);
3820 * free_area_init_nodes - Initialise all pg_data_t and zone data
3821 * @max_zone_pfn: an array of max PFNs for each zone
3823 * This will call free_area_init_node() for each active node in the system.
3824 * Using the page ranges provided by add_active_range(), the size of each
3825 * zone in each node and their holes is calculated. If the maximum PFN
3826 * between two adjacent zones match, it is assumed that the zone is empty.
3827 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
3828 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
3829 * starts where the previous one ended. For example, ZONE_DMA32 starts
3830 * at arch_max_dma_pfn.
3832 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
3837 /* Sort early_node_map as initialisation assumes it is sorted */
3840 /* Record where the zone boundaries are */
3841 memset(arch_zone_lowest_possible_pfn
, 0,
3842 sizeof(arch_zone_lowest_possible_pfn
));
3843 memset(arch_zone_highest_possible_pfn
, 0,
3844 sizeof(arch_zone_highest_possible_pfn
));
3845 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
3846 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
3847 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
3848 if (i
== ZONE_MOVABLE
)
3850 arch_zone_lowest_possible_pfn
[i
] =
3851 arch_zone_highest_possible_pfn
[i
-1];
3852 arch_zone_highest_possible_pfn
[i
] =
3853 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
3855 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
3856 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
3858 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
3859 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
3860 find_zone_movable_pfns_for_nodes(zone_movable_pfn
);
3862 /* Print out the zone ranges */
3863 printk("Zone PFN ranges:\n");
3864 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
3865 if (i
== ZONE_MOVABLE
)
3867 printk(" %-8s %8lu -> %8lu\n",
3869 arch_zone_lowest_possible_pfn
[i
],
3870 arch_zone_highest_possible_pfn
[i
]);
3873 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
3874 printk("Movable zone start PFN for each node\n");
3875 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
3876 if (zone_movable_pfn
[i
])
3877 printk(" Node %d: %lu\n", i
, zone_movable_pfn
[i
]);
3880 /* Print out the early_node_map[] */
3881 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries
);
3882 for (i
= 0; i
< nr_nodemap_entries
; i
++)
3883 printk(" %3d: %8lu -> %8lu\n", early_node_map
[i
].nid
,
3884 early_node_map
[i
].start_pfn
,
3885 early_node_map
[i
].end_pfn
);
3887 /* Initialise every node */
3888 setup_nr_node_ids();
3889 for_each_online_node(nid
) {
3890 pg_data_t
*pgdat
= NODE_DATA(nid
);
3891 free_area_init_node(nid
, pgdat
, NULL
,
3892 find_min_pfn_for_node(nid
), NULL
);
3894 /* Any memory on that node */
3895 if (pgdat
->node_present_pages
)
3896 node_set_state(nid
, N_HIGH_MEMORY
);
3897 check_for_regular_memory(pgdat
);
3901 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
3903 unsigned long long coremem
;
3907 coremem
= memparse(p
, &p
);
3908 *core
= coremem
>> PAGE_SHIFT
;
3910 /* Paranoid check that UL is enough for the coremem value */
3911 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
3917 * kernelcore=size sets the amount of memory for use for allocations that
3918 * cannot be reclaimed or migrated.
3920 static int __init
cmdline_parse_kernelcore(char *p
)
3922 return cmdline_parse_core(p
, &required_kernelcore
);
3926 * movablecore=size sets the amount of memory for use for allocations that
3927 * can be reclaimed or migrated.
3929 static int __init
cmdline_parse_movablecore(char *p
)
3931 return cmdline_parse_core(p
, &required_movablecore
);
3934 early_param("kernelcore", cmdline_parse_kernelcore
);
3935 early_param("movablecore", cmdline_parse_movablecore
);
3937 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
3940 * set_dma_reserve - set the specified number of pages reserved in the first zone
3941 * @new_dma_reserve: The number of pages to mark reserved
3943 * The per-cpu batchsize and zone watermarks are determined by present_pages.
3944 * In the DMA zone, a significant percentage may be consumed by kernel image
3945 * and other unfreeable allocations which can skew the watermarks badly. This
3946 * function may optionally be used to account for unfreeable pages in the
3947 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
3948 * smaller per-cpu batchsize.
3950 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
3952 dma_reserve
= new_dma_reserve
;
3955 #ifndef CONFIG_NEED_MULTIPLE_NODES
3956 static bootmem_data_t contig_bootmem_data
;
3957 struct pglist_data contig_page_data
= { .bdata
= &contig_bootmem_data
};
3959 EXPORT_SYMBOL(contig_page_data
);
3962 void __init
free_area_init(unsigned long *zones_size
)
3964 free_area_init_node(0, NODE_DATA(0), zones_size
,
3965 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
3968 static int page_alloc_cpu_notify(struct notifier_block
*self
,
3969 unsigned long action
, void *hcpu
)
3971 int cpu
= (unsigned long)hcpu
;
3973 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
3977 * Spill the event counters of the dead processor
3978 * into the current processors event counters.
3979 * This artificially elevates the count of the current
3982 vm_events_fold_cpu(cpu
);
3985 * Zero the differential counters of the dead processor
3986 * so that the vm statistics are consistent.
3988 * This is only okay since the processor is dead and cannot
3989 * race with what we are doing.
3991 refresh_cpu_vm_stats(cpu
);
3996 void __init
page_alloc_init(void)
3998 hotcpu_notifier(page_alloc_cpu_notify
, 0);
4002 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
4003 * or min_free_kbytes changes.
4005 static void calculate_totalreserve_pages(void)
4007 struct pglist_data
*pgdat
;
4008 unsigned long reserve_pages
= 0;
4009 enum zone_type i
, j
;
4011 for_each_online_pgdat(pgdat
) {
4012 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4013 struct zone
*zone
= pgdat
->node_zones
+ i
;
4014 unsigned long max
= 0;
4016 /* Find valid and maximum lowmem_reserve in the zone */
4017 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
4018 if (zone
->lowmem_reserve
[j
] > max
)
4019 max
= zone
->lowmem_reserve
[j
];
4022 /* we treat pages_high as reserved pages. */
4023 max
+= zone
->pages_high
;
4025 if (max
> zone
->present_pages
)
4026 max
= zone
->present_pages
;
4027 reserve_pages
+= max
;
4030 totalreserve_pages
= reserve_pages
;
4034 * setup_per_zone_lowmem_reserve - called whenever
4035 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
4036 * has a correct pages reserved value, so an adequate number of
4037 * pages are left in the zone after a successful __alloc_pages().
4039 static void setup_per_zone_lowmem_reserve(void)
4041 struct pglist_data
*pgdat
;
4042 enum zone_type j
, idx
;
4044 for_each_online_pgdat(pgdat
) {
4045 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4046 struct zone
*zone
= pgdat
->node_zones
+ j
;
4047 unsigned long present_pages
= zone
->present_pages
;
4049 zone
->lowmem_reserve
[j
] = 0;
4053 struct zone
*lower_zone
;
4057 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
4058 sysctl_lowmem_reserve_ratio
[idx
] = 1;
4060 lower_zone
= pgdat
->node_zones
+ idx
;
4061 lower_zone
->lowmem_reserve
[j
] = present_pages
/
4062 sysctl_lowmem_reserve_ratio
[idx
];
4063 present_pages
+= lower_zone
->present_pages
;
4068 /* update totalreserve_pages */
4069 calculate_totalreserve_pages();
4073 * setup_per_zone_pages_min - called when min_free_kbytes changes.
4075 * Ensures that the pages_{min,low,high} values for each zone are set correctly
4076 * with respect to min_free_kbytes.
4078 void setup_per_zone_pages_min(void)
4080 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
4081 unsigned long lowmem_pages
= 0;
4083 unsigned long flags
;
4085 /* Calculate total number of !ZONE_HIGHMEM pages */
4086 for_each_zone(zone
) {
4087 if (!is_highmem(zone
))
4088 lowmem_pages
+= zone
->present_pages
;
4091 for_each_zone(zone
) {
4094 spin_lock_irqsave(&zone
->lru_lock
, flags
);
4095 tmp
= (u64
)pages_min
* zone
->present_pages
;
4096 do_div(tmp
, lowmem_pages
);
4097 if (is_highmem(zone
)) {
4099 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
4100 * need highmem pages, so cap pages_min to a small
4103 * The (pages_high-pages_low) and (pages_low-pages_min)
4104 * deltas controls asynch page reclaim, and so should
4105 * not be capped for highmem.
4109 min_pages
= zone
->present_pages
/ 1024;
4110 if (min_pages
< SWAP_CLUSTER_MAX
)
4111 min_pages
= SWAP_CLUSTER_MAX
;
4112 if (min_pages
> 128)
4114 zone
->pages_min
= min_pages
;
4117 * If it's a lowmem zone, reserve a number of pages
4118 * proportionate to the zone's size.
4120 zone
->pages_min
= tmp
;
4123 zone
->pages_low
= zone
->pages_min
+ (tmp
>> 2);
4124 zone
->pages_high
= zone
->pages_min
+ (tmp
>> 1);
4125 setup_zone_migrate_reserve(zone
);
4126 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4129 /* update totalreserve_pages */
4130 calculate_totalreserve_pages();
4134 * Initialise min_free_kbytes.
4136 * For small machines we want it small (128k min). For large machines
4137 * we want it large (64MB max). But it is not linear, because network
4138 * bandwidth does not increase linearly with machine size. We use
4140 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
4141 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
4157 static int __init
init_per_zone_pages_min(void)
4159 unsigned long lowmem_kbytes
;
4161 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
4163 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
4164 if (min_free_kbytes
< 128)
4165 min_free_kbytes
= 128;
4166 if (min_free_kbytes
> 65536)
4167 min_free_kbytes
= 65536;
4168 setup_per_zone_pages_min();
4169 setup_per_zone_lowmem_reserve();
4172 module_init(init_per_zone_pages_min
)
4175 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
4176 * that we can call two helper functions whenever min_free_kbytes
4179 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
4180 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4182 proc_dointvec(table
, write
, file
, buffer
, length
, ppos
);
4184 setup_per_zone_pages_min();
4189 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
4190 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4195 rc
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4200 zone
->min_unmapped_pages
= (zone
->present_pages
*
4201 sysctl_min_unmapped_ratio
) / 100;
4205 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
4206 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4211 rc
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4216 zone
->min_slab_pages
= (zone
->present_pages
*
4217 sysctl_min_slab_ratio
) / 100;
4223 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
4224 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
4225 * whenever sysctl_lowmem_reserve_ratio changes.
4227 * The reserve ratio obviously has absolutely no relation with the
4228 * pages_min watermarks. The lowmem reserve ratio can only make sense
4229 * if in function of the boot time zone sizes.
4231 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
4232 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4234 proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4235 setup_per_zone_lowmem_reserve();
4240 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
4241 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
4242 * can have before it gets flushed back to buddy allocator.
4245 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
4246 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4252 ret
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4253 if (!write
|| (ret
== -EINVAL
))
4255 for_each_zone(zone
) {
4256 for_each_online_cpu(cpu
) {
4258 high
= zone
->present_pages
/ percpu_pagelist_fraction
;
4259 setup_pagelist_highmark(zone_pcp(zone
, cpu
), high
);
4265 int hashdist
= HASHDIST_DEFAULT
;
4268 static int __init
set_hashdist(char *str
)
4272 hashdist
= simple_strtoul(str
, &str
, 0);
4275 __setup("hashdist=", set_hashdist
);
4279 * allocate a large system hash table from bootmem
4280 * - it is assumed that the hash table must contain an exact power-of-2
4281 * quantity of entries
4282 * - limit is the number of hash buckets, not the total allocation size
4284 void *__init
alloc_large_system_hash(const char *tablename
,
4285 unsigned long bucketsize
,
4286 unsigned long numentries
,
4289 unsigned int *_hash_shift
,
4290 unsigned int *_hash_mask
,
4291 unsigned long limit
)
4293 unsigned long long max
= limit
;
4294 unsigned long log2qty
, size
;
4297 /* allow the kernel cmdline to have a say */
4299 /* round applicable memory size up to nearest megabyte */
4300 numentries
= nr_kernel_pages
;
4301 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
4302 numentries
>>= 20 - PAGE_SHIFT
;
4303 numentries
<<= 20 - PAGE_SHIFT
;
4305 /* limit to 1 bucket per 2^scale bytes of low memory */
4306 if (scale
> PAGE_SHIFT
)
4307 numentries
>>= (scale
- PAGE_SHIFT
);
4309 numentries
<<= (PAGE_SHIFT
- scale
);
4311 /* Make sure we've got at least a 0-order allocation.. */
4312 if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
4313 numentries
= PAGE_SIZE
/ bucketsize
;
4315 numentries
= roundup_pow_of_two(numentries
);
4317 /* limit allocation size to 1/16 total memory by default */
4319 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
4320 do_div(max
, bucketsize
);
4323 if (numentries
> max
)
4326 log2qty
= ilog2(numentries
);
4329 size
= bucketsize
<< log2qty
;
4330 if (flags
& HASH_EARLY
)
4331 table
= alloc_bootmem(size
);
4333 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
4335 unsigned long order
;
4336 for (order
= 0; ((1UL << order
) << PAGE_SHIFT
) < size
; order
++)
4338 table
= (void*) __get_free_pages(GFP_ATOMIC
, order
);
4340 * If bucketsize is not a power-of-two, we may free
4341 * some pages at the end of hash table.
4344 unsigned long alloc_end
= (unsigned long)table
+
4345 (PAGE_SIZE
<< order
);
4346 unsigned long used
= (unsigned long)table
+
4348 split_page(virt_to_page(table
), order
);
4349 while (used
< alloc_end
) {
4355 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
4358 panic("Failed to allocate %s hash table\n", tablename
);
4360 printk(KERN_INFO
"%s hash table entries: %d (order: %d, %lu bytes)\n",
4363 ilog2(size
) - PAGE_SHIFT
,
4367 *_hash_shift
= log2qty
;
4369 *_hash_mask
= (1 << log2qty
) - 1;
4374 #ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
4375 struct page
*pfn_to_page(unsigned long pfn
)
4377 return __pfn_to_page(pfn
);
4379 unsigned long page_to_pfn(struct page
*page
)
4381 return __page_to_pfn(page
);
4383 EXPORT_SYMBOL(pfn_to_page
);
4384 EXPORT_SYMBOL(page_to_pfn
);
4385 #endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */
4387 /* Return a pointer to the bitmap storing bits affecting a block of pages */
4388 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
4391 #ifdef CONFIG_SPARSEMEM
4392 return __pfn_to_section(pfn
)->pageblock_flags
;
4394 return zone
->pageblock_flags
;
4395 #endif /* CONFIG_SPARSEMEM */
4398 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
4400 #ifdef CONFIG_SPARSEMEM
4401 pfn
&= (PAGES_PER_SECTION
-1);
4402 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
4404 pfn
= pfn
- zone
->zone_start_pfn
;
4405 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
4406 #endif /* CONFIG_SPARSEMEM */
4410 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4411 * @page: The page within the block of interest
4412 * @start_bitidx: The first bit of interest to retrieve
4413 * @end_bitidx: The last bit of interest
4414 * returns pageblock_bits flags
4416 unsigned long get_pageblock_flags_group(struct page
*page
,
4417 int start_bitidx
, int end_bitidx
)
4420 unsigned long *bitmap
;
4421 unsigned long pfn
, bitidx
;
4422 unsigned long flags
= 0;
4423 unsigned long value
= 1;
4425 zone
= page_zone(page
);
4426 pfn
= page_to_pfn(page
);
4427 bitmap
= get_pageblock_bitmap(zone
, pfn
);
4428 bitidx
= pfn_to_bitidx(zone
, pfn
);
4430 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
4431 if (test_bit(bitidx
+ start_bitidx
, bitmap
))
4438 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
4439 * @page: The page within the block of interest
4440 * @start_bitidx: The first bit of interest
4441 * @end_bitidx: The last bit of interest
4442 * @flags: The flags to set
4444 void set_pageblock_flags_group(struct page
*page
, unsigned long flags
,
4445 int start_bitidx
, int end_bitidx
)
4448 unsigned long *bitmap
;
4449 unsigned long pfn
, bitidx
;
4450 unsigned long value
= 1;
4452 zone
= page_zone(page
);
4453 pfn
= page_to_pfn(page
);
4454 bitmap
= get_pageblock_bitmap(zone
, pfn
);
4455 bitidx
= pfn_to_bitidx(zone
, pfn
);
4457 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
4459 __set_bit(bitidx
+ start_bitidx
, bitmap
);
4461 __clear_bit(bitidx
+ start_bitidx
, bitmap
);
4465 * This is designed as sub function...plz see page_isolation.c also.
4466 * set/clear page block's type to be ISOLATE.
4467 * page allocater never alloc memory from ISOLATE block.
4470 int set_migratetype_isolate(struct page
*page
)
4473 unsigned long flags
;
4476 zone
= page_zone(page
);
4477 spin_lock_irqsave(&zone
->lock
, flags
);
4479 * In future, more migrate types will be able to be isolation target.
4481 if (get_pageblock_migratetype(page
) != MIGRATE_MOVABLE
)
4483 set_pageblock_migratetype(page
, MIGRATE_ISOLATE
);
4484 move_freepages_block(zone
, page
, MIGRATE_ISOLATE
);
4487 spin_unlock_irqrestore(&zone
->lock
, flags
);
4493 void unset_migratetype_isolate(struct page
*page
)
4496 unsigned long flags
;
4497 zone
= page_zone(page
);
4498 spin_lock_irqsave(&zone
->lock
, flags
);
4499 if (get_pageblock_migratetype(page
) != MIGRATE_ISOLATE
)
4501 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4502 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
4504 spin_unlock_irqrestore(&zone
->lock
, flags
);
4507 #ifdef CONFIG_MEMORY_HOTREMOVE
4509 * All pages in the range must be isolated before calling this.
4512 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
4518 unsigned long flags
;
4519 /* find the first valid pfn */
4520 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
4525 zone
= page_zone(pfn_to_page(pfn
));
4526 spin_lock_irqsave(&zone
->lock
, flags
);
4528 while (pfn
< end_pfn
) {
4529 if (!pfn_valid(pfn
)) {
4533 page
= pfn_to_page(pfn
);
4534 BUG_ON(page_count(page
));
4535 BUG_ON(!PageBuddy(page
));
4536 order
= page_order(page
);
4537 #ifdef CONFIG_DEBUG_VM
4538 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
4539 pfn
, 1 << order
, end_pfn
);
4541 list_del(&page
->lru
);
4542 rmv_page_order(page
);
4543 zone
->free_area
[order
].nr_free
--;
4544 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
4546 for (i
= 0; i
< (1 << order
); i
++)
4547 SetPageReserved((page
+i
));
4548 pfn
+= (1 << order
);
4550 spin_unlock_irqrestore(&zone
->lock
, flags
);