2 * linux/mm/page_alloc.c
4 * Manages the free list, the system allocates free pages here.
5 * Note that kmalloc() lives in slab.c
7 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
8 * Swap reorganised 29.12.95, Stephen Tweedie
9 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
10 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
11 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
12 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000
13 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
14 * (lots of bits borrowed from Ingo Molnar & Andrew Morton)
17 #include <linux/stddef.h>
19 #include <linux/swap.h>
20 #include <linux/interrupt.h>
21 #include <linux/pagemap.h>
22 #include <linux/jiffies.h>
23 #include <linux/bootmem.h>
24 #include <linux/compiler.h>
25 #include <linux/kernel.h>
26 #include <linux/module.h>
27 #include <linux/suspend.h>
28 #include <linux/pagevec.h>
29 #include <linux/blkdev.h>
30 #include <linux/slab.h>
31 #include <linux/oom.h>
32 #include <linux/notifier.h>
33 #include <linux/topology.h>
34 #include <linux/sysctl.h>
35 #include <linux/cpu.h>
36 #include <linux/cpuset.h>
37 #include <linux/memory_hotplug.h>
38 #include <linux/nodemask.h>
39 #include <linux/vmalloc.h>
40 #include <linux/mempolicy.h>
41 #include <linux/stop_machine.h>
42 #include <linux/sort.h>
43 #include <linux/pfn.h>
44 #include <linux/backing-dev.h>
45 #include <linux/fault-inject.h>
46 #include <linux/page-isolation.h>
47 #include <linux/page_cgroup.h>
48 #include <linux/debugobjects.h>
50 #include <asm/tlbflush.h>
51 #include <asm/div64.h>
55 * Array of node states.
57 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
58 [N_POSSIBLE
] = NODE_MASK_ALL
,
59 [N_ONLINE
] = { { [0] = 1UL } },
61 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
63 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
65 [N_CPU
] = { { [0] = 1UL } },
68 EXPORT_SYMBOL(node_states
);
70 unsigned long totalram_pages __read_mostly
;
71 unsigned long totalreserve_pages __read_mostly
;
72 int percpu_pagelist_fraction
;
74 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
75 int pageblock_order __read_mostly
;
78 static void __free_pages_ok(struct page
*page
, unsigned int order
);
81 * results with 256, 32 in the lowmem_reserve sysctl:
82 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
83 * 1G machine -> (16M dma, 784M normal, 224M high)
84 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
85 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
86 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
88 * TBD: should special case ZONE_DMA32 machines here - in those we normally
89 * don't need any ZONE_NORMAL reservation
91 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
92 #ifdef CONFIG_ZONE_DMA
95 #ifdef CONFIG_ZONE_DMA32
104 EXPORT_SYMBOL(totalram_pages
);
106 static char * const zone_names
[MAX_NR_ZONES
] = {
107 #ifdef CONFIG_ZONE_DMA
110 #ifdef CONFIG_ZONE_DMA32
114 #ifdef CONFIG_HIGHMEM
120 int min_free_kbytes
= 1024;
122 unsigned long __meminitdata nr_kernel_pages
;
123 unsigned long __meminitdata nr_all_pages
;
124 static unsigned long __meminitdata dma_reserve
;
126 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
128 * MAX_ACTIVE_REGIONS determines the maximum number of distinct
129 * ranges of memory (RAM) that may be registered with add_active_range().
130 * Ranges passed to add_active_range() will be merged if possible
131 * so the number of times add_active_range() can be called is
132 * related to the number of nodes and the number of holes
134 #ifdef CONFIG_MAX_ACTIVE_REGIONS
135 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */
136 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
138 #if MAX_NUMNODES >= 32
139 /* If there can be many nodes, allow up to 50 holes per node */
140 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
142 /* By default, allow up to 256 distinct regions */
143 #define MAX_ACTIVE_REGIONS 256
147 static struct node_active_region __meminitdata early_node_map
[MAX_ACTIVE_REGIONS
];
148 static int __meminitdata nr_nodemap_entries
;
149 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
150 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
151 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
152 static unsigned long __meminitdata node_boundary_start_pfn
[MAX_NUMNODES
];
153 static unsigned long __meminitdata node_boundary_end_pfn
[MAX_NUMNODES
];
154 #endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
155 static unsigned long __initdata required_kernelcore
;
156 static unsigned long __initdata required_movablecore
;
157 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
159 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
161 EXPORT_SYMBOL(movable_zone
);
162 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
165 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
166 EXPORT_SYMBOL(nr_node_ids
);
169 int page_group_by_mobility_disabled __read_mostly
;
171 static void set_pageblock_migratetype(struct page
*page
, int migratetype
)
173 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
174 PB_migrate
, PB_migrate_end
);
177 #ifdef CONFIG_DEBUG_VM
178 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
182 unsigned long pfn
= page_to_pfn(page
);
185 seq
= zone_span_seqbegin(zone
);
186 if (pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
188 else if (pfn
< zone
->zone_start_pfn
)
190 } while (zone_span_seqretry(zone
, seq
));
195 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
197 if (!pfn_valid_within(page_to_pfn(page
)))
199 if (zone
!= page_zone(page
))
205 * Temporary debugging check for pages not lying within a given zone.
207 static int bad_range(struct zone
*zone
, struct page
*page
)
209 if (page_outside_zone_boundaries(zone
, page
))
211 if (!page_is_consistent(zone
, page
))
217 static inline int bad_range(struct zone
*zone
, struct page
*page
)
223 static void bad_page(struct page
*page
)
225 printk(KERN_EMERG
"Bad page state in process '%s'\n" KERN_EMERG
226 "page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n",
227 current
->comm
, page
, (int)(2*sizeof(unsigned long)),
228 (unsigned long)page
->flags
, page
->mapping
,
229 page_mapcount(page
), page_count(page
));
231 printk(KERN_EMERG
"Trying to fix it up, but a reboot is needed\n"
232 KERN_EMERG
"Backtrace:\n");
234 set_page_count(page
, 0);
235 reset_page_mapcount(page
);
236 page
->mapping
= NULL
;
237 add_taint(TAINT_BAD_PAGE
);
241 * Higher-order pages are called "compound pages". They are structured thusly:
243 * The first PAGE_SIZE page is called the "head page".
245 * The remaining PAGE_SIZE pages are called "tail pages".
247 * All pages have PG_compound set. All pages have their ->private pointing at
248 * the head page (even the head page has this).
250 * The first tail page's ->lru.next holds the address of the compound page's
251 * put_page() function. Its ->lru.prev holds the order of allocation.
252 * This usage means that zero-order pages may not be compound.
255 static void free_compound_page(struct page
*page
)
257 __free_pages_ok(page
, compound_order(page
));
260 void prep_compound_page(struct page
*page
, unsigned long order
)
263 int nr_pages
= 1 << order
;
265 set_compound_page_dtor(page
, free_compound_page
);
266 set_compound_order(page
, order
);
268 for (i
= 1; i
< nr_pages
; i
++) {
269 struct page
*p
= page
+ i
;
272 p
->first_page
= page
;
276 #ifdef CONFIG_HUGETLBFS
277 void prep_compound_gigantic_page(struct page
*page
, unsigned long order
)
280 int nr_pages
= 1 << order
;
281 struct page
*p
= page
+ 1;
283 set_compound_page_dtor(page
, free_compound_page
);
284 set_compound_order(page
, order
);
286 for (i
= 1; i
< nr_pages
; i
++, p
= mem_map_next(p
, page
, i
)) {
288 p
->first_page
= page
;
293 static void destroy_compound_page(struct page
*page
, unsigned long order
)
296 int nr_pages
= 1 << order
;
298 if (unlikely(compound_order(page
) != order
))
301 if (unlikely(!PageHead(page
)))
303 __ClearPageHead(page
);
304 for (i
= 1; i
< nr_pages
; i
++) {
305 struct page
*p
= page
+ i
;
307 if (unlikely(!PageTail(p
) |
308 (p
->first_page
!= page
)))
314 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
319 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
320 * and __GFP_HIGHMEM from hard or soft interrupt context.
322 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
323 for (i
= 0; i
< (1 << order
); i
++)
324 clear_highpage(page
+ i
);
327 static inline void set_page_order(struct page
*page
, int order
)
329 set_page_private(page
, order
);
330 __SetPageBuddy(page
);
333 static inline void rmv_page_order(struct page
*page
)
335 __ClearPageBuddy(page
);
336 set_page_private(page
, 0);
340 * Locate the struct page for both the matching buddy in our
341 * pair (buddy1) and the combined O(n+1) page they form (page).
343 * 1) Any buddy B1 will have an order O twin B2 which satisfies
344 * the following equation:
346 * For example, if the starting buddy (buddy2) is #8 its order
348 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
350 * 2) Any buddy B will have an order O+1 parent P which
351 * satisfies the following equation:
354 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
356 static inline struct page
*
357 __page_find_buddy(struct page
*page
, unsigned long page_idx
, unsigned int order
)
359 unsigned long buddy_idx
= page_idx
^ (1 << order
);
361 return page
+ (buddy_idx
- page_idx
);
364 static inline unsigned long
365 __find_combined_index(unsigned long page_idx
, unsigned int order
)
367 return (page_idx
& ~(1 << order
));
371 * This function checks whether a page is free && is the buddy
372 * we can do coalesce a page and its buddy if
373 * (a) the buddy is not in a hole &&
374 * (b) the buddy is in the buddy system &&
375 * (c) a page and its buddy have the same order &&
376 * (d) a page and its buddy are in the same zone.
378 * For recording whether a page is in the buddy system, we use PG_buddy.
379 * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
381 * For recording page's order, we use page_private(page).
383 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
386 if (!pfn_valid_within(page_to_pfn(buddy
)))
389 if (page_zone_id(page
) != page_zone_id(buddy
))
392 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
393 BUG_ON(page_count(buddy
) != 0);
400 * Freeing function for a buddy system allocator.
402 * The concept of a buddy system is to maintain direct-mapped table
403 * (containing bit values) for memory blocks of various "orders".
404 * The bottom level table contains the map for the smallest allocatable
405 * units of memory (here, pages), and each level above it describes
406 * pairs of units from the levels below, hence, "buddies".
407 * At a high level, all that happens here is marking the table entry
408 * at the bottom level available, and propagating the changes upward
409 * as necessary, plus some accounting needed to play nicely with other
410 * parts of the VM system.
411 * At each level, we keep a list of pages, which are heads of continuous
412 * free pages of length of (1 << order) and marked with PG_buddy. Page's
413 * order is recorded in page_private(page) field.
414 * So when we are allocating or freeing one, we can derive the state of the
415 * other. That is, if we allocate a small block, and both were
416 * free, the remainder of the region must be split into blocks.
417 * If a block is freed, and its buddy is also free, then this
418 * triggers coalescing into a block of larger size.
423 static inline void __free_one_page(struct page
*page
,
424 struct zone
*zone
, unsigned int order
)
426 unsigned long page_idx
;
427 int order_size
= 1 << order
;
428 int migratetype
= get_pageblock_migratetype(page
);
430 if (unlikely(PageCompound(page
)))
431 destroy_compound_page(page
, order
);
433 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
435 VM_BUG_ON(page_idx
& (order_size
- 1));
436 VM_BUG_ON(bad_range(zone
, page
));
438 __mod_zone_page_state(zone
, NR_FREE_PAGES
, order_size
);
439 while (order
< MAX_ORDER
-1) {
440 unsigned long combined_idx
;
443 buddy
= __page_find_buddy(page
, page_idx
, order
);
444 if (!page_is_buddy(page
, buddy
, order
))
447 /* Our buddy is free, merge with it and move up one order. */
448 list_del(&buddy
->lru
);
449 zone
->free_area
[order
].nr_free
--;
450 rmv_page_order(buddy
);
451 combined_idx
= __find_combined_index(page_idx
, order
);
452 page
= page
+ (combined_idx
- page_idx
);
453 page_idx
= combined_idx
;
456 set_page_order(page
, order
);
458 &zone
->free_area
[order
].free_list
[migratetype
]);
459 zone
->free_area
[order
].nr_free
++;
462 static inline int free_pages_check(struct page
*page
)
464 free_page_mlock(page
);
465 if (unlikely(page_mapcount(page
) |
466 (page
->mapping
!= NULL
) |
467 (page_count(page
) != 0) |
468 (page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)))
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 if (PageReserved(page
))
477 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
478 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
483 * Frees a list of pages.
484 * Assumes all pages on list are in same zone, and of same order.
485 * count is the number of pages to free.
487 * If the zone was previously in an "all pages pinned" state then look to
488 * see if this freeing clears that state.
490 * And clear the zone's pages_scanned counter, to hold off the "all pages are
491 * pinned" detection logic.
493 static void free_pages_bulk(struct zone
*zone
, int count
,
494 struct list_head
*list
, int order
)
496 spin_lock(&zone
->lock
);
497 zone_clear_flag(zone
, ZONE_ALL_UNRECLAIMABLE
);
498 zone
->pages_scanned
= 0;
502 VM_BUG_ON(list_empty(list
));
503 page
= list_entry(list
->prev
, struct page
, lru
);
504 /* have to delete it as __free_one_page list manipulates */
505 list_del(&page
->lru
);
506 __free_one_page(page
, zone
, order
);
508 spin_unlock(&zone
->lock
);
511 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
)
513 spin_lock(&zone
->lock
);
514 zone_clear_flag(zone
, ZONE_ALL_UNRECLAIMABLE
);
515 zone
->pages_scanned
= 0;
516 __free_one_page(page
, zone
, order
);
517 spin_unlock(&zone
->lock
);
520 static void __free_pages_ok(struct page
*page
, unsigned int order
)
526 for (i
= 0 ; i
< (1 << order
) ; ++i
)
527 reserved
+= free_pages_check(page
+ i
);
531 if (!PageHighMem(page
)) {
532 debug_check_no_locks_freed(page_address(page
),PAGE_SIZE
<<order
);
533 debug_check_no_obj_freed(page_address(page
),
536 arch_free_page(page
, order
);
537 kernel_map_pages(page
, 1 << order
, 0);
539 local_irq_save(flags
);
540 __count_vm_events(PGFREE
, 1 << order
);
541 free_one_page(page_zone(page
), page
, order
);
542 local_irq_restore(flags
);
546 * permit the bootmem allocator to evade page validation on high-order frees
548 void __meminit
__free_pages_bootmem(struct page
*page
, unsigned int order
)
551 __ClearPageReserved(page
);
552 set_page_count(page
, 0);
553 set_page_refcounted(page
);
559 for (loop
= 0; loop
< BITS_PER_LONG
; loop
++) {
560 struct page
*p
= &page
[loop
];
562 if (loop
+ 1 < BITS_PER_LONG
)
564 __ClearPageReserved(p
);
565 set_page_count(p
, 0);
568 set_page_refcounted(page
);
569 __free_pages(page
, order
);
575 * The order of subdivision here is critical for the IO subsystem.
576 * Please do not alter this order without good reasons and regression
577 * testing. Specifically, as large blocks of memory are subdivided,
578 * the order in which smaller blocks are delivered depends on the order
579 * they're subdivided in this function. This is the primary factor
580 * influencing the order in which pages are delivered to the IO
581 * subsystem according to empirical testing, and this is also justified
582 * by considering the behavior of a buddy system containing a single
583 * large block of memory acted on by a series of small allocations.
584 * This behavior is a critical factor in sglist merging's success.
588 static inline void expand(struct zone
*zone
, struct page
*page
,
589 int low
, int high
, struct free_area
*area
,
592 unsigned long size
= 1 << high
;
598 VM_BUG_ON(bad_range(zone
, &page
[size
]));
599 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
601 set_page_order(&page
[size
], high
);
606 * This page is about to be returned from the page allocator
608 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
610 if (unlikely(page_mapcount(page
) |
611 (page
->mapping
!= NULL
) |
612 (page_count(page
) != 0) |
613 (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)))
617 * For now, we report if PG_reserved was found set, but do not
618 * clear it, and do not allocate the page: as a safety net.
620 if (PageReserved(page
))
623 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
624 set_page_private(page
, 0);
625 set_page_refcounted(page
);
627 arch_alloc_page(page
, order
);
628 kernel_map_pages(page
, 1 << order
, 1);
630 if (gfp_flags
& __GFP_ZERO
)
631 prep_zero_page(page
, order
, gfp_flags
);
633 if (order
&& (gfp_flags
& __GFP_COMP
))
634 prep_compound_page(page
, order
);
640 * Go through the free lists for the given migratetype and remove
641 * the smallest available page from the freelists
643 static struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
646 unsigned int current_order
;
647 struct free_area
* area
;
650 /* Find a page of the appropriate size in the preferred list */
651 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
652 area
= &(zone
->free_area
[current_order
]);
653 if (list_empty(&area
->free_list
[migratetype
]))
656 page
= list_entry(area
->free_list
[migratetype
].next
,
658 list_del(&page
->lru
);
659 rmv_page_order(page
);
661 __mod_zone_page_state(zone
, NR_FREE_PAGES
, - (1UL << order
));
662 expand(zone
, page
, order
, current_order
, area
, migratetype
);
671 * This array describes the order lists are fallen back to when
672 * the free lists for the desirable migrate type are depleted
674 static int fallbacks
[MIGRATE_TYPES
][MIGRATE_TYPES
-1] = {
675 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
676 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
677 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
678 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
, MIGRATE_RESERVE
, MIGRATE_RESERVE
}, /* Never used */
682 * Move the free pages in a range to the free lists of the requested type.
683 * Note that start_page and end_pages are not aligned on a pageblock
684 * boundary. If alignment is required, use move_freepages_block()
686 static int move_freepages(struct zone
*zone
,
687 struct page
*start_page
, struct page
*end_page
,
694 #ifndef CONFIG_HOLES_IN_ZONE
696 * page_zone is not safe to call in this context when
697 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
698 * anyway as we check zone boundaries in move_freepages_block().
699 * Remove at a later date when no bug reports exist related to
700 * grouping pages by mobility
702 BUG_ON(page_zone(start_page
) != page_zone(end_page
));
705 for (page
= start_page
; page
<= end_page
;) {
706 /* Make sure we are not inadvertently changing nodes */
707 VM_BUG_ON(page_to_nid(page
) != zone_to_nid(zone
));
709 if (!pfn_valid_within(page_to_pfn(page
))) {
714 if (!PageBuddy(page
)) {
719 order
= page_order(page
);
720 list_del(&page
->lru
);
722 &zone
->free_area
[order
].free_list
[migratetype
]);
724 pages_moved
+= 1 << order
;
730 static int move_freepages_block(struct zone
*zone
, struct page
*page
,
733 unsigned long start_pfn
, end_pfn
;
734 struct page
*start_page
, *end_page
;
736 start_pfn
= page_to_pfn(page
);
737 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
738 start_page
= pfn_to_page(start_pfn
);
739 end_page
= start_page
+ pageblock_nr_pages
- 1;
740 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
742 /* Do not cross zone boundaries */
743 if (start_pfn
< zone
->zone_start_pfn
)
745 if (end_pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
748 return move_freepages(zone
, start_page
, end_page
, migratetype
);
751 /* Remove an element from the buddy allocator from the fallback list */
752 static struct page
*__rmqueue_fallback(struct zone
*zone
, int order
,
753 int start_migratetype
)
755 struct free_area
* area
;
760 /* Find the largest possible block of pages in the other list */
761 for (current_order
= MAX_ORDER
-1; current_order
>= order
;
763 for (i
= 0; i
< MIGRATE_TYPES
- 1; i
++) {
764 migratetype
= fallbacks
[start_migratetype
][i
];
766 /* MIGRATE_RESERVE handled later if necessary */
767 if (migratetype
== MIGRATE_RESERVE
)
770 area
= &(zone
->free_area
[current_order
]);
771 if (list_empty(&area
->free_list
[migratetype
]))
774 page
= list_entry(area
->free_list
[migratetype
].next
,
779 * If breaking a large block of pages, move all free
780 * pages to the preferred allocation list. If falling
781 * back for a reclaimable kernel allocation, be more
782 * agressive about taking ownership of free pages
784 if (unlikely(current_order
>= (pageblock_order
>> 1)) ||
785 start_migratetype
== MIGRATE_RECLAIMABLE
) {
787 pages
= move_freepages_block(zone
, page
,
790 /* Claim the whole block if over half of it is free */
791 if (pages
>= (1 << (pageblock_order
-1)))
792 set_pageblock_migratetype(page
,
795 migratetype
= start_migratetype
;
798 /* Remove the page from the freelists */
799 list_del(&page
->lru
);
800 rmv_page_order(page
);
801 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
804 if (current_order
== pageblock_order
)
805 set_pageblock_migratetype(page
,
808 expand(zone
, page
, order
, current_order
, area
, migratetype
);
813 /* Use MIGRATE_RESERVE rather than fail an allocation */
814 return __rmqueue_smallest(zone
, order
, MIGRATE_RESERVE
);
818 * Do the hard work of removing an element from the buddy allocator.
819 * Call me with the zone->lock already held.
821 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
826 page
= __rmqueue_smallest(zone
, order
, migratetype
);
829 page
= __rmqueue_fallback(zone
, order
, migratetype
);
835 * Obtain a specified number of elements from the buddy allocator, all under
836 * a single hold of the lock, for efficiency. Add them to the supplied list.
837 * Returns the number of new pages which were placed at *list.
839 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
840 unsigned long count
, struct list_head
*list
,
845 spin_lock(&zone
->lock
);
846 for (i
= 0; i
< count
; ++i
) {
847 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
848 if (unlikely(page
== NULL
))
852 * Split buddy pages returned by expand() are received here
853 * in physical page order. The page is added to the callers and
854 * list and the list head then moves forward. From the callers
855 * perspective, the linked list is ordered by page number in
856 * some conditions. This is useful for IO devices that can
857 * merge IO requests if the physical pages are ordered
860 list_add(&page
->lru
, list
);
861 set_page_private(page
, migratetype
);
864 spin_unlock(&zone
->lock
);
870 * Called from the vmstat counter updater to drain pagesets of this
871 * currently executing processor on remote nodes after they have
874 * Note that this function must be called with the thread pinned to
875 * a single processor.
877 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
882 local_irq_save(flags
);
883 if (pcp
->count
>= pcp
->batch
)
884 to_drain
= pcp
->batch
;
886 to_drain
= pcp
->count
;
887 free_pages_bulk(zone
, to_drain
, &pcp
->list
, 0);
888 pcp
->count
-= to_drain
;
889 local_irq_restore(flags
);
894 * Drain pages of the indicated processor.
896 * The processor must either be the current processor and the
897 * thread pinned to the current processor or a processor that
900 static void drain_pages(unsigned int cpu
)
905 for_each_zone(zone
) {
906 struct per_cpu_pageset
*pset
;
907 struct per_cpu_pages
*pcp
;
909 if (!populated_zone(zone
))
912 pset
= zone_pcp(zone
, cpu
);
915 local_irq_save(flags
);
916 free_pages_bulk(zone
, pcp
->count
, &pcp
->list
, 0);
918 local_irq_restore(flags
);
923 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
925 void drain_local_pages(void *arg
)
927 drain_pages(smp_processor_id());
931 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
933 void drain_all_pages(void)
935 on_each_cpu(drain_local_pages
, NULL
, 1);
938 #ifdef CONFIG_HIBERNATION
940 void mark_free_pages(struct zone
*zone
)
942 unsigned long pfn
, max_zone_pfn
;
945 struct list_head
*curr
;
947 if (!zone
->spanned_pages
)
950 spin_lock_irqsave(&zone
->lock
, flags
);
952 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
953 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
954 if (pfn_valid(pfn
)) {
955 struct page
*page
= pfn_to_page(pfn
);
957 if (!swsusp_page_is_forbidden(page
))
958 swsusp_unset_page_free(page
);
961 for_each_migratetype_order(order
, t
) {
962 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
965 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
966 for (i
= 0; i
< (1UL << order
); i
++)
967 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
970 spin_unlock_irqrestore(&zone
->lock
, flags
);
972 #endif /* CONFIG_PM */
975 * Free a 0-order page
977 static void free_hot_cold_page(struct page
*page
, int cold
)
979 struct zone
*zone
= page_zone(page
);
980 struct per_cpu_pages
*pcp
;
984 page
->mapping
= NULL
;
985 if (free_pages_check(page
))
988 if (!PageHighMem(page
)) {
989 debug_check_no_locks_freed(page_address(page
), PAGE_SIZE
);
990 debug_check_no_obj_freed(page_address(page
), PAGE_SIZE
);
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 zone
*preferred_zone
,
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(preferred_zone
, 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 (time_after(jiffies
, zlc
->last_full_zap
+ 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 zoneref
*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
->_zonerefs
;
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 zoneref
*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
->_zonerefs
;
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 zoneref
*z
,
1357 nodemask_t
*allowednodes
)
1362 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*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
, nodemask_t
*nodemask
, unsigned int order
,
1373 struct zonelist
*zonelist
, int high_zoneidx
, int alloc_flags
)
1376 struct page
*page
= NULL
;
1378 struct zone
*zone
, *preferred_zone
;
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 */
1383 (void)first_zones_zonelist(zonelist
, high_zoneidx
, nodemask
,
1385 if (!preferred_zone
)
1388 classzone_idx
= zone_idx(preferred_zone
);
1392 * Scan zonelist, looking for a zone with enough free.
1393 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1395 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
1396 high_zoneidx
, nodemask
) {
1397 if (NUMA_BUILD
&& zlc_active
&&
1398 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1400 if ((alloc_flags
& ALLOC_CPUSET
) &&
1401 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1404 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
1406 if (alloc_flags
& ALLOC_WMARK_MIN
)
1407 mark
= zone
->pages_min
;
1408 else if (alloc_flags
& ALLOC_WMARK_LOW
)
1409 mark
= zone
->pages_low
;
1411 mark
= zone
->pages_high
;
1412 if (!zone_watermark_ok(zone
, order
, mark
,
1413 classzone_idx
, alloc_flags
)) {
1414 if (!zone_reclaim_mode
||
1415 !zone_reclaim(zone
, gfp_mask
, order
))
1416 goto this_zone_full
;
1420 page
= buffered_rmqueue(preferred_zone
, zone
, order
, gfp_mask
);
1425 zlc_mark_zone_full(zonelist
, z
);
1427 if (NUMA_BUILD
&& !did_zlc_setup
) {
1428 /* we do zlc_setup after the first zone is tried */
1429 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1435 if (unlikely(NUMA_BUILD
&& page
== NULL
&& zlc_active
)) {
1436 /* Disable zlc cache for second zonelist scan */
1444 * This is the 'heart' of the zoned buddy allocator.
1447 __alloc_pages_internal(gfp_t gfp_mask
, unsigned int order
,
1448 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
1450 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
1451 enum zone_type high_zoneidx
= gfp_zone(gfp_mask
);
1455 struct reclaim_state reclaim_state
;
1456 struct task_struct
*p
= current
;
1459 unsigned long did_some_progress
;
1460 unsigned long pages_reclaimed
= 0;
1462 might_sleep_if(wait
);
1464 if (should_fail_alloc_page(gfp_mask
, order
))
1468 z
= zonelist
->_zonerefs
; /* the list of zones suitable for gfp_mask */
1470 if (unlikely(!z
->zone
)) {
1472 * Happens if we have an empty zonelist as a result of
1473 * GFP_THISNODE being used on a memoryless node
1478 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
, order
,
1479 zonelist
, high_zoneidx
, ALLOC_WMARK_LOW
|ALLOC_CPUSET
);
1484 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
1485 * __GFP_NOWARN set) should not cause reclaim since the subsystem
1486 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
1487 * using a larger set of nodes after it has established that the
1488 * allowed per node queues are empty and that nodes are
1491 if (NUMA_BUILD
&& (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
1494 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
)
1495 wakeup_kswapd(zone
, order
);
1498 * OK, we're below the kswapd watermark and have kicked background
1499 * reclaim. Now things get more complex, so set up alloc_flags according
1500 * to how we want to proceed.
1502 * The caller may dip into page reserves a bit more if the caller
1503 * cannot run direct reclaim, or if the caller has realtime scheduling
1504 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
1505 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1507 alloc_flags
= ALLOC_WMARK_MIN
;
1508 if ((unlikely(rt_task(p
)) && !in_interrupt()) || !wait
)
1509 alloc_flags
|= ALLOC_HARDER
;
1510 if (gfp_mask
& __GFP_HIGH
)
1511 alloc_flags
|= ALLOC_HIGH
;
1513 alloc_flags
|= ALLOC_CPUSET
;
1516 * Go through the zonelist again. Let __GFP_HIGH and allocations
1517 * coming from realtime tasks go deeper into reserves.
1519 * This is the last chance, in general, before the goto nopage.
1520 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1521 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1523 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
, zonelist
,
1524 high_zoneidx
, alloc_flags
);
1528 /* This allocation should allow future memory freeing. */
1531 if (((p
->flags
& PF_MEMALLOC
) || unlikely(test_thread_flag(TIF_MEMDIE
)))
1532 && !in_interrupt()) {
1533 if (!(gfp_mask
& __GFP_NOMEMALLOC
)) {
1535 /* go through the zonelist yet again, ignoring mins */
1536 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
1537 zonelist
, high_zoneidx
, ALLOC_NO_WATERMARKS
);
1540 if (gfp_mask
& __GFP_NOFAIL
) {
1541 congestion_wait(WRITE
, HZ
/50);
1548 /* Atomic allocations - we can't balance anything */
1554 /* We now go into synchronous reclaim */
1555 cpuset_memory_pressure_bump();
1557 * The task's cpuset might have expanded its set of allowable nodes
1559 cpuset_update_task_memory_state();
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
, 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
, nodemask
, order
,
1576 zonelist
, high_zoneidx
, alloc_flags
);
1579 } else if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
1580 if (!try_set_zone_oom(zonelist
, gfp_mask
)) {
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
, nodemask
,
1592 order
, zonelist
, high_zoneidx
,
1593 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
);
1595 clear_zonelist_oom(zonelist
, gfp_mask
);
1599 /* The OOM killer will not help higher order allocs so fail */
1600 if (order
> PAGE_ALLOC_COSTLY_ORDER
) {
1601 clear_zonelist_oom(zonelist
, gfp_mask
);
1605 out_of_memory(zonelist
, gfp_mask
, order
);
1606 clear_zonelist_oom(zonelist
, gfp_mask
);
1611 * Don't let big-order allocations loop unless the caller explicitly
1612 * requests that. Wait for some write requests to complete then retry.
1614 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
1615 * means __GFP_NOFAIL, but that may not be true in other
1618 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
1619 * specified, then we retry until we no longer reclaim any pages
1620 * (above), or we've reclaimed an order of pages at least as
1621 * large as the allocation's order. In both cases, if the
1622 * allocation still fails, we stop retrying.
1624 pages_reclaimed
+= did_some_progress
;
1626 if (!(gfp_mask
& __GFP_NORETRY
)) {
1627 if (order
<= PAGE_ALLOC_COSTLY_ORDER
) {
1630 if (gfp_mask
& __GFP_REPEAT
&&
1631 pages_reclaimed
< (1 << order
))
1634 if (gfp_mask
& __GFP_NOFAIL
)
1638 congestion_wait(WRITE
, HZ
/50);
1643 if (!(gfp_mask
& __GFP_NOWARN
) && printk_ratelimit()) {
1644 printk(KERN_WARNING
"%s: page allocation failure."
1645 " order:%d, mode:0x%x\n",
1646 p
->comm
, order
, gfp_mask
);
1653 EXPORT_SYMBOL(__alloc_pages_internal
);
1656 * Common helper functions.
1658 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
1661 page
= alloc_pages(gfp_mask
, order
);
1664 return (unsigned long) page_address(page
);
1667 EXPORT_SYMBOL(__get_free_pages
);
1669 unsigned long get_zeroed_page(gfp_t gfp_mask
)
1674 * get_zeroed_page() returns a 32-bit address, which cannot represent
1677 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
1679 page
= alloc_pages(gfp_mask
| __GFP_ZERO
, 0);
1681 return (unsigned long) page_address(page
);
1685 EXPORT_SYMBOL(get_zeroed_page
);
1687 void __pagevec_free(struct pagevec
*pvec
)
1689 int i
= pagevec_count(pvec
);
1692 free_hot_cold_page(pvec
->pages
[i
], pvec
->cold
);
1695 void __free_pages(struct page
*page
, unsigned int order
)
1697 if (put_page_testzero(page
)) {
1699 free_hot_page(page
);
1701 __free_pages_ok(page
, order
);
1705 EXPORT_SYMBOL(__free_pages
);
1707 void free_pages(unsigned long addr
, unsigned int order
)
1710 VM_BUG_ON(!virt_addr_valid((void *)addr
));
1711 __free_pages(virt_to_page((void *)addr
), order
);
1715 EXPORT_SYMBOL(free_pages
);
1718 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
1719 * @size: the number of bytes to allocate
1720 * @gfp_mask: GFP flags for the allocation
1722 * This function is similar to alloc_pages(), except that it allocates the
1723 * minimum number of pages to satisfy the request. alloc_pages() can only
1724 * allocate memory in power-of-two pages.
1726 * This function is also limited by MAX_ORDER.
1728 * Memory allocated by this function must be released by free_pages_exact().
1730 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
1732 unsigned int order
= get_order(size
);
1735 addr
= __get_free_pages(gfp_mask
, order
);
1737 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
1738 unsigned long used
= addr
+ PAGE_ALIGN(size
);
1740 split_page(virt_to_page(addr
), order
);
1741 while (used
< alloc_end
) {
1747 return (void *)addr
;
1749 EXPORT_SYMBOL(alloc_pages_exact
);
1752 * free_pages_exact - release memory allocated via alloc_pages_exact()
1753 * @virt: the value returned by alloc_pages_exact.
1754 * @size: size of allocation, same value as passed to alloc_pages_exact().
1756 * Release the memory allocated by a previous call to alloc_pages_exact.
1758 void free_pages_exact(void *virt
, size_t size
)
1760 unsigned long addr
= (unsigned long)virt
;
1761 unsigned long end
= addr
+ PAGE_ALIGN(size
);
1763 while (addr
< end
) {
1768 EXPORT_SYMBOL(free_pages_exact
);
1770 static unsigned int nr_free_zone_pages(int offset
)
1775 /* Just pick one node, since fallback list is circular */
1776 unsigned int sum
= 0;
1778 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
1780 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
1781 unsigned long size
= zone
->present_pages
;
1782 unsigned long high
= zone
->pages_high
;
1791 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
1793 unsigned int nr_free_buffer_pages(void)
1795 return nr_free_zone_pages(gfp_zone(GFP_USER
));
1797 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
1800 * Amount of free RAM allocatable within all zones
1802 unsigned int nr_free_pagecache_pages(void)
1804 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
1807 static inline void show_node(struct zone
*zone
)
1810 printk("Node %d ", zone_to_nid(zone
));
1813 void si_meminfo(struct sysinfo
*val
)
1815 val
->totalram
= totalram_pages
;
1817 val
->freeram
= global_page_state(NR_FREE_PAGES
);
1818 val
->bufferram
= nr_blockdev_pages();
1819 val
->totalhigh
= totalhigh_pages
;
1820 val
->freehigh
= nr_free_highpages();
1821 val
->mem_unit
= PAGE_SIZE
;
1824 EXPORT_SYMBOL(si_meminfo
);
1827 void si_meminfo_node(struct sysinfo
*val
, int nid
)
1829 pg_data_t
*pgdat
= NODE_DATA(nid
);
1831 val
->totalram
= pgdat
->node_present_pages
;
1832 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
1833 #ifdef CONFIG_HIGHMEM
1834 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
1835 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
1841 val
->mem_unit
= PAGE_SIZE
;
1845 #define K(x) ((x) << (PAGE_SHIFT-10))
1848 * Show free area list (used inside shift_scroll-lock stuff)
1849 * We also calculate the percentage fragmentation. We do this by counting the
1850 * memory on each free list with the exception of the first item on the list.
1852 void show_free_areas(void)
1857 for_each_zone(zone
) {
1858 if (!populated_zone(zone
))
1862 printk("%s per-cpu:\n", zone
->name
);
1864 for_each_online_cpu(cpu
) {
1865 struct per_cpu_pageset
*pageset
;
1867 pageset
= zone_pcp(zone
, cpu
);
1869 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
1870 cpu
, pageset
->pcp
.high
,
1871 pageset
->pcp
.batch
, pageset
->pcp
.count
);
1875 printk("Active_anon:%lu active_file:%lu inactive_anon:%lu\n"
1876 " inactive_file:%lu"
1877 //TODO: check/adjust line lengths
1878 #ifdef CONFIG_UNEVICTABLE_LRU
1881 " dirty:%lu writeback:%lu unstable:%lu\n"
1882 " free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n",
1883 global_page_state(NR_ACTIVE_ANON
),
1884 global_page_state(NR_ACTIVE_FILE
),
1885 global_page_state(NR_INACTIVE_ANON
),
1886 global_page_state(NR_INACTIVE_FILE
),
1887 #ifdef CONFIG_UNEVICTABLE_LRU
1888 global_page_state(NR_UNEVICTABLE
),
1890 global_page_state(NR_FILE_DIRTY
),
1891 global_page_state(NR_WRITEBACK
),
1892 global_page_state(NR_UNSTABLE_NFS
),
1893 global_page_state(NR_FREE_PAGES
),
1894 global_page_state(NR_SLAB_RECLAIMABLE
) +
1895 global_page_state(NR_SLAB_UNRECLAIMABLE
),
1896 global_page_state(NR_FILE_MAPPED
),
1897 global_page_state(NR_PAGETABLE
),
1898 global_page_state(NR_BOUNCE
));
1900 for_each_zone(zone
) {
1903 if (!populated_zone(zone
))
1912 " active_anon:%lukB"
1913 " inactive_anon:%lukB"
1914 " active_file:%lukB"
1915 " inactive_file:%lukB"
1916 #ifdef CONFIG_UNEVICTABLE_LRU
1917 " unevictable:%lukB"
1920 " pages_scanned:%lu"
1921 " all_unreclaimable? %s"
1924 K(zone_page_state(zone
, NR_FREE_PAGES
)),
1927 K(zone
->pages_high
),
1928 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
1929 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
1930 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
1931 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
1932 #ifdef CONFIG_UNEVICTABLE_LRU
1933 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
1935 K(zone
->present_pages
),
1936 zone
->pages_scanned
,
1937 (zone_is_all_unreclaimable(zone
) ? "yes" : "no")
1939 printk("lowmem_reserve[]:");
1940 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
1941 printk(" %lu", zone
->lowmem_reserve
[i
]);
1945 for_each_zone(zone
) {
1946 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
1948 if (!populated_zone(zone
))
1952 printk("%s: ", zone
->name
);
1954 spin_lock_irqsave(&zone
->lock
, flags
);
1955 for (order
= 0; order
< MAX_ORDER
; order
++) {
1956 nr
[order
] = zone
->free_area
[order
].nr_free
;
1957 total
+= nr
[order
] << order
;
1959 spin_unlock_irqrestore(&zone
->lock
, flags
);
1960 for (order
= 0; order
< MAX_ORDER
; order
++)
1961 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
1962 printk("= %lukB\n", K(total
));
1965 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
1967 show_swap_cache_info();
1970 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
1972 zoneref
->zone
= zone
;
1973 zoneref
->zone_idx
= zone_idx(zone
);
1977 * Builds allocation fallback zone lists.
1979 * Add all populated zones of a node to the zonelist.
1981 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
1982 int nr_zones
, enum zone_type zone_type
)
1986 BUG_ON(zone_type
>= MAX_NR_ZONES
);
1991 zone
= pgdat
->node_zones
+ zone_type
;
1992 if (populated_zone(zone
)) {
1993 zoneref_set_zone(zone
,
1994 &zonelist
->_zonerefs
[nr_zones
++]);
1995 check_highest_zone(zone_type
);
1998 } while (zone_type
);
2005 * 0 = automatic detection of better ordering.
2006 * 1 = order by ([node] distance, -zonetype)
2007 * 2 = order by (-zonetype, [node] distance)
2009 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
2010 * the same zonelist. So only NUMA can configure this param.
2012 #define ZONELIST_ORDER_DEFAULT 0
2013 #define ZONELIST_ORDER_NODE 1
2014 #define ZONELIST_ORDER_ZONE 2
2016 /* zonelist order in the kernel.
2017 * set_zonelist_order() will set this to NODE or ZONE.
2019 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2020 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
2024 /* The value user specified ....changed by config */
2025 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2026 /* string for sysctl */
2027 #define NUMA_ZONELIST_ORDER_LEN 16
2028 char numa_zonelist_order
[16] = "default";
2031 * interface for configure zonelist ordering.
2032 * command line option "numa_zonelist_order"
2033 * = "[dD]efault - default, automatic configuration.
2034 * = "[nN]ode - order by node locality, then by zone within node
2035 * = "[zZ]one - order by zone, then by locality within zone
2038 static int __parse_numa_zonelist_order(char *s
)
2040 if (*s
== 'd' || *s
== 'D') {
2041 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2042 } else if (*s
== 'n' || *s
== 'N') {
2043 user_zonelist_order
= ZONELIST_ORDER_NODE
;
2044 } else if (*s
== 'z' || *s
== 'Z') {
2045 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
2048 "Ignoring invalid numa_zonelist_order value: "
2055 static __init
int setup_numa_zonelist_order(char *s
)
2058 return __parse_numa_zonelist_order(s
);
2061 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
2064 * sysctl handler for numa_zonelist_order
2066 int numa_zonelist_order_handler(ctl_table
*table
, int write
,
2067 struct file
*file
, void __user
*buffer
, size_t *length
,
2070 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
2074 strncpy(saved_string
, (char*)table
->data
,
2075 NUMA_ZONELIST_ORDER_LEN
);
2076 ret
= proc_dostring(table
, write
, file
, buffer
, length
, ppos
);
2080 int oldval
= user_zonelist_order
;
2081 if (__parse_numa_zonelist_order((char*)table
->data
)) {
2083 * bogus value. restore saved string
2085 strncpy((char*)table
->data
, saved_string
,
2086 NUMA_ZONELIST_ORDER_LEN
);
2087 user_zonelist_order
= oldval
;
2088 } else if (oldval
!= user_zonelist_order
)
2089 build_all_zonelists();
2095 #define MAX_NODE_LOAD (num_online_nodes())
2096 static int node_load
[MAX_NUMNODES
];
2099 * find_next_best_node - find the next node that should appear in a given node's fallback list
2100 * @node: node whose fallback list we're appending
2101 * @used_node_mask: nodemask_t of already used nodes
2103 * We use a number of factors to determine which is the next node that should
2104 * appear on a given node's fallback list. The node should not have appeared
2105 * already in @node's fallback list, and it should be the next closest node
2106 * according to the distance array (which contains arbitrary distance values
2107 * from each node to each node in the system), and should also prefer nodes
2108 * with no CPUs, since presumably they'll have very little allocation pressure
2109 * on them otherwise.
2110 * It returns -1 if no node is found.
2112 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
2115 int min_val
= INT_MAX
;
2117 node_to_cpumask_ptr(tmp
, 0);
2119 /* Use the local node if we haven't already */
2120 if (!node_isset(node
, *used_node_mask
)) {
2121 node_set(node
, *used_node_mask
);
2125 for_each_node_state(n
, N_HIGH_MEMORY
) {
2127 /* Don't want a node to appear more than once */
2128 if (node_isset(n
, *used_node_mask
))
2131 /* Use the distance array to find the distance */
2132 val
= node_distance(node
, n
);
2134 /* Penalize nodes under us ("prefer the next node") */
2137 /* Give preference to headless and unused nodes */
2138 node_to_cpumask_ptr_next(tmp
, n
);
2139 if (!cpus_empty(*tmp
))
2140 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
2142 /* Slight preference for less loaded node */
2143 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
2144 val
+= node_load
[n
];
2146 if (val
< min_val
) {
2153 node_set(best_node
, *used_node_mask
);
2160 * Build zonelists ordered by node and zones within node.
2161 * This results in maximum locality--normal zone overflows into local
2162 * DMA zone, if any--but risks exhausting DMA zone.
2164 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
2167 struct zonelist
*zonelist
;
2169 zonelist
= &pgdat
->node_zonelists
[0];
2170 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
2172 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2174 zonelist
->_zonerefs
[j
].zone
= NULL
;
2175 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2179 * Build gfp_thisnode zonelists
2181 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
2184 struct zonelist
*zonelist
;
2186 zonelist
= &pgdat
->node_zonelists
[1];
2187 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
2188 zonelist
->_zonerefs
[j
].zone
= NULL
;
2189 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2193 * Build zonelists ordered by zone and nodes within zones.
2194 * This results in conserving DMA zone[s] until all Normal memory is
2195 * exhausted, but results in overflowing to remote node while memory
2196 * may still exist in local DMA zone.
2198 static int node_order
[MAX_NUMNODES
];
2200 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
2203 int zone_type
; /* needs to be signed */
2205 struct zonelist
*zonelist
;
2207 zonelist
= &pgdat
->node_zonelists
[0];
2209 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
2210 for (j
= 0; j
< nr_nodes
; j
++) {
2211 node
= node_order
[j
];
2212 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
2213 if (populated_zone(z
)) {
2215 &zonelist
->_zonerefs
[pos
++]);
2216 check_highest_zone(zone_type
);
2220 zonelist
->_zonerefs
[pos
].zone
= NULL
;
2221 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
2224 static int default_zonelist_order(void)
2227 unsigned long low_kmem_size
,total_size
;
2231 * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem.
2232 * If they are really small and used heavily, the system can fall
2233 * into OOM very easily.
2234 * This function detect ZONE_DMA/DMA32 size and confgigures zone order.
2236 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
2239 for_each_online_node(nid
) {
2240 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2241 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2242 if (populated_zone(z
)) {
2243 if (zone_type
< ZONE_NORMAL
)
2244 low_kmem_size
+= z
->present_pages
;
2245 total_size
+= z
->present_pages
;
2249 if (!low_kmem_size
|| /* there are no DMA area. */
2250 low_kmem_size
> total_size
/2) /* DMA/DMA32 is big. */
2251 return ZONELIST_ORDER_NODE
;
2253 * look into each node's config.
2254 * If there is a node whose DMA/DMA32 memory is very big area on
2255 * local memory, NODE_ORDER may be suitable.
2257 average_size
= total_size
/
2258 (nodes_weight(node_states
[N_HIGH_MEMORY
]) + 1);
2259 for_each_online_node(nid
) {
2262 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2263 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2264 if (populated_zone(z
)) {
2265 if (zone_type
< ZONE_NORMAL
)
2266 low_kmem_size
+= z
->present_pages
;
2267 total_size
+= z
->present_pages
;
2270 if (low_kmem_size
&&
2271 total_size
> average_size
&& /* ignore small node */
2272 low_kmem_size
> total_size
* 70/100)
2273 return ZONELIST_ORDER_NODE
;
2275 return ZONELIST_ORDER_ZONE
;
2278 static void set_zonelist_order(void)
2280 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
2281 current_zonelist_order
= default_zonelist_order();
2283 current_zonelist_order
= user_zonelist_order
;
2286 static void build_zonelists(pg_data_t
*pgdat
)
2290 nodemask_t used_mask
;
2291 int local_node
, prev_node
;
2292 struct zonelist
*zonelist
;
2293 int order
= current_zonelist_order
;
2295 /* initialize zonelists */
2296 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
2297 zonelist
= pgdat
->node_zonelists
+ i
;
2298 zonelist
->_zonerefs
[0].zone
= NULL
;
2299 zonelist
->_zonerefs
[0].zone_idx
= 0;
2302 /* NUMA-aware ordering of nodes */
2303 local_node
= pgdat
->node_id
;
2304 load
= num_online_nodes();
2305 prev_node
= local_node
;
2306 nodes_clear(used_mask
);
2308 memset(node_load
, 0, sizeof(node_load
));
2309 memset(node_order
, 0, sizeof(node_order
));
2312 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
2313 int distance
= node_distance(local_node
, node
);
2316 * If another node is sufficiently far away then it is better
2317 * to reclaim pages in a zone before going off node.
2319 if (distance
> RECLAIM_DISTANCE
)
2320 zone_reclaim_mode
= 1;
2323 * We don't want to pressure a particular node.
2324 * So adding penalty to the first node in same
2325 * distance group to make it round-robin.
2327 if (distance
!= node_distance(local_node
, prev_node
))
2328 node_load
[node
] = load
;
2332 if (order
== ZONELIST_ORDER_NODE
)
2333 build_zonelists_in_node_order(pgdat
, node
);
2335 node_order
[j
++] = node
; /* remember order */
2338 if (order
== ZONELIST_ORDER_ZONE
) {
2339 /* calculate node order -- i.e., DMA last! */
2340 build_zonelists_in_zone_order(pgdat
, j
);
2343 build_thisnode_zonelists(pgdat
);
2346 /* Construct the zonelist performance cache - see further mmzone.h */
2347 static void build_zonelist_cache(pg_data_t
*pgdat
)
2349 struct zonelist
*zonelist
;
2350 struct zonelist_cache
*zlc
;
2353 zonelist
= &pgdat
->node_zonelists
[0];
2354 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
2355 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
2356 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
2357 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
2361 #else /* CONFIG_NUMA */
2363 static void set_zonelist_order(void)
2365 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
2368 static void build_zonelists(pg_data_t
*pgdat
)
2370 int node
, local_node
;
2372 struct zonelist
*zonelist
;
2374 local_node
= pgdat
->node_id
;
2376 zonelist
= &pgdat
->node_zonelists
[0];
2377 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
2380 * Now we build the zonelist so that it contains the zones
2381 * of all the other nodes.
2382 * We don't want to pressure a particular node, so when
2383 * building the zones for node N, we make sure that the
2384 * zones coming right after the local ones are those from
2385 * node N+1 (modulo N)
2387 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
2388 if (!node_online(node
))
2390 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2393 for (node
= 0; node
< local_node
; node
++) {
2394 if (!node_online(node
))
2396 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2400 zonelist
->_zonerefs
[j
].zone
= NULL
;
2401 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2404 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2405 static void build_zonelist_cache(pg_data_t
*pgdat
)
2407 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
2410 #endif /* CONFIG_NUMA */
2412 /* return values int ....just for stop_machine() */
2413 static int __build_all_zonelists(void *dummy
)
2417 for_each_online_node(nid
) {
2418 pg_data_t
*pgdat
= NODE_DATA(nid
);
2420 build_zonelists(pgdat
);
2421 build_zonelist_cache(pgdat
);
2426 void build_all_zonelists(void)
2428 set_zonelist_order();
2430 if (system_state
== SYSTEM_BOOTING
) {
2431 __build_all_zonelists(NULL
);
2432 mminit_verify_zonelist();
2433 cpuset_init_current_mems_allowed();
2435 /* we have to stop all cpus to guarantee there is no user
2437 stop_machine(__build_all_zonelists
, NULL
, NULL
);
2438 /* cpuset refresh routine should be here */
2440 vm_total_pages
= nr_free_pagecache_pages();
2442 * Disable grouping by mobility if the number of pages in the
2443 * system is too low to allow the mechanism to work. It would be
2444 * more accurate, but expensive to check per-zone. This check is
2445 * made on memory-hotadd so a system can start with mobility
2446 * disabled and enable it later
2448 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
2449 page_group_by_mobility_disabled
= 1;
2451 page_group_by_mobility_disabled
= 0;
2453 printk("Built %i zonelists in %s order, mobility grouping %s. "
2454 "Total pages: %ld\n",
2456 zonelist_order_name
[current_zonelist_order
],
2457 page_group_by_mobility_disabled
? "off" : "on",
2460 printk("Policy zone: %s\n", zone_names
[policy_zone
]);
2465 * Helper functions to size the waitqueue hash table.
2466 * Essentially these want to choose hash table sizes sufficiently
2467 * large so that collisions trying to wait on pages are rare.
2468 * But in fact, the number of active page waitqueues on typical
2469 * systems is ridiculously low, less than 200. So this is even
2470 * conservative, even though it seems large.
2472 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
2473 * waitqueues, i.e. the size of the waitq table given the number of pages.
2475 #define PAGES_PER_WAITQUEUE 256
2477 #ifndef CONFIG_MEMORY_HOTPLUG
2478 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
2480 unsigned long size
= 1;
2482 pages
/= PAGES_PER_WAITQUEUE
;
2484 while (size
< pages
)
2488 * Once we have dozens or even hundreds of threads sleeping
2489 * on IO we've got bigger problems than wait queue collision.
2490 * Limit the size of the wait table to a reasonable size.
2492 size
= min(size
, 4096UL);
2494 return max(size
, 4UL);
2498 * A zone's size might be changed by hot-add, so it is not possible to determine
2499 * a suitable size for its wait_table. So we use the maximum size now.
2501 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
2503 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
2504 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
2505 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
2507 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
2508 * or more by the traditional way. (See above). It equals:
2510 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
2511 * ia64(16K page size) : = ( 8G + 4M)byte.
2512 * powerpc (64K page size) : = (32G +16M)byte.
2514 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
2521 * This is an integer logarithm so that shifts can be used later
2522 * to extract the more random high bits from the multiplicative
2523 * hash function before the remainder is taken.
2525 static inline unsigned long wait_table_bits(unsigned long size
)
2530 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
2533 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2534 * of blocks reserved is based on zone->pages_min. The memory within the
2535 * reserve will tend to store contiguous free pages. Setting min_free_kbytes
2536 * higher will lead to a bigger reserve which will get freed as contiguous
2537 * blocks as reclaim kicks in
2539 static void setup_zone_migrate_reserve(struct zone
*zone
)
2541 unsigned long start_pfn
, pfn
, end_pfn
;
2543 unsigned long reserve
, block_migratetype
;
2545 /* Get the start pfn, end pfn and the number of blocks to reserve */
2546 start_pfn
= zone
->zone_start_pfn
;
2547 end_pfn
= start_pfn
+ zone
->spanned_pages
;
2548 reserve
= roundup(zone
->pages_min
, pageblock_nr_pages
) >>
2551 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
2552 if (!pfn_valid(pfn
))
2554 page
= pfn_to_page(pfn
);
2556 /* Watch out for overlapping nodes */
2557 if (page_to_nid(page
) != zone_to_nid(zone
))
2560 /* Blocks with reserved pages will never free, skip them. */
2561 if (PageReserved(page
))
2564 block_migratetype
= get_pageblock_migratetype(page
);
2566 /* If this block is reserved, account for it */
2567 if (reserve
> 0 && block_migratetype
== MIGRATE_RESERVE
) {
2572 /* Suitable for reserving if this block is movable */
2573 if (reserve
> 0 && block_migratetype
== MIGRATE_MOVABLE
) {
2574 set_pageblock_migratetype(page
, MIGRATE_RESERVE
);
2575 move_freepages_block(zone
, page
, MIGRATE_RESERVE
);
2581 * If the reserve is met and this is a previous reserved block,
2584 if (block_migratetype
== MIGRATE_RESERVE
) {
2585 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
2586 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
2592 * Initially all pages are reserved - free ones are freed
2593 * up by free_all_bootmem() once the early boot process is
2594 * done. Non-atomic initialization, single-pass.
2596 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
2597 unsigned long start_pfn
, enum memmap_context context
)
2600 unsigned long end_pfn
= start_pfn
+ size
;
2604 z
= &NODE_DATA(nid
)->node_zones
[zone
];
2605 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
2607 * There can be holes in boot-time mem_map[]s
2608 * handed to this function. They do not
2609 * exist on hotplugged memory.
2611 if (context
== MEMMAP_EARLY
) {
2612 if (!early_pfn_valid(pfn
))
2614 if (!early_pfn_in_nid(pfn
, nid
))
2617 page
= pfn_to_page(pfn
);
2618 set_page_links(page
, zone
, nid
, pfn
);
2619 mminit_verify_page_links(page
, zone
, nid
, pfn
);
2620 init_page_count(page
);
2621 reset_page_mapcount(page
);
2622 SetPageReserved(page
);
2624 * Mark the block movable so that blocks are reserved for
2625 * movable at startup. This will force kernel allocations
2626 * to reserve their blocks rather than leaking throughout
2627 * the address space during boot when many long-lived
2628 * kernel allocations are made. Later some blocks near
2629 * the start are marked MIGRATE_RESERVE by
2630 * setup_zone_migrate_reserve()
2632 * bitmap is created for zone's valid pfn range. but memmap
2633 * can be created for invalid pages (for alignment)
2634 * check here not to call set_pageblock_migratetype() against
2637 if ((z
->zone_start_pfn
<= pfn
)
2638 && (pfn
< z
->zone_start_pfn
+ z
->spanned_pages
)
2639 && !(pfn
& (pageblock_nr_pages
- 1)))
2640 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
2642 INIT_LIST_HEAD(&page
->lru
);
2643 #ifdef WANT_PAGE_VIRTUAL
2644 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
2645 if (!is_highmem_idx(zone
))
2646 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
2651 static void __meminit
zone_init_free_lists(struct zone
*zone
)
2654 for_each_migratetype_order(order
, t
) {
2655 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
2656 zone
->free_area
[order
].nr_free
= 0;
2660 #ifndef __HAVE_ARCH_MEMMAP_INIT
2661 #define memmap_init(size, nid, zone, start_pfn) \
2662 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
2665 static int zone_batchsize(struct zone
*zone
)
2670 * The per-cpu-pages pools are set to around 1000th of the
2671 * size of the zone. But no more than 1/2 of a meg.
2673 * OK, so we don't know how big the cache is. So guess.
2675 batch
= zone
->present_pages
/ 1024;
2676 if (batch
* PAGE_SIZE
> 512 * 1024)
2677 batch
= (512 * 1024) / PAGE_SIZE
;
2678 batch
/= 4; /* We effectively *= 4 below */
2683 * Clamp the batch to a 2^n - 1 value. Having a power
2684 * of 2 value was found to be more likely to have
2685 * suboptimal cache aliasing properties in some cases.
2687 * For example if 2 tasks are alternately allocating
2688 * batches of pages, one task can end up with a lot
2689 * of pages of one half of the possible page colors
2690 * and the other with pages of the other colors.
2692 batch
= (1 << (fls(batch
+ batch
/2)-1)) - 1;
2697 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
2699 struct per_cpu_pages
*pcp
;
2701 memset(p
, 0, sizeof(*p
));
2705 pcp
->high
= 6 * batch
;
2706 pcp
->batch
= max(1UL, 1 * batch
);
2707 INIT_LIST_HEAD(&pcp
->list
);
2711 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
2712 * to the value high for the pageset p.
2715 static void setup_pagelist_highmark(struct per_cpu_pageset
*p
,
2718 struct per_cpu_pages
*pcp
;
2722 pcp
->batch
= max(1UL, high
/4);
2723 if ((high
/4) > (PAGE_SHIFT
* 8))
2724 pcp
->batch
= PAGE_SHIFT
* 8;
2730 * Boot pageset table. One per cpu which is going to be used for all
2731 * zones and all nodes. The parameters will be set in such a way
2732 * that an item put on a list will immediately be handed over to
2733 * the buddy list. This is safe since pageset manipulation is done
2734 * with interrupts disabled.
2736 * Some NUMA counter updates may also be caught by the boot pagesets.
2738 * The boot_pagesets must be kept even after bootup is complete for
2739 * unused processors and/or zones. They do play a role for bootstrapping
2740 * hotplugged processors.
2742 * zoneinfo_show() and maybe other functions do
2743 * not check if the processor is online before following the pageset pointer.
2744 * Other parts of the kernel may not check if the zone is available.
2746 static struct per_cpu_pageset boot_pageset
[NR_CPUS
];
2749 * Dynamically allocate memory for the
2750 * per cpu pageset array in struct zone.
2752 static int __cpuinit
process_zones(int cpu
)
2754 struct zone
*zone
, *dzone
;
2755 int node
= cpu_to_node(cpu
);
2757 node_set_state(node
, N_CPU
); /* this node has a cpu */
2759 for_each_zone(zone
) {
2761 if (!populated_zone(zone
))
2764 zone_pcp(zone
, cpu
) = kmalloc_node(sizeof(struct per_cpu_pageset
),
2766 if (!zone_pcp(zone
, cpu
))
2769 setup_pageset(zone_pcp(zone
, cpu
), zone_batchsize(zone
));
2771 if (percpu_pagelist_fraction
)
2772 setup_pagelist_highmark(zone_pcp(zone
, cpu
),
2773 (zone
->present_pages
/ percpu_pagelist_fraction
));
2778 for_each_zone(dzone
) {
2779 if (!populated_zone(dzone
))
2783 kfree(zone_pcp(dzone
, cpu
));
2784 zone_pcp(dzone
, cpu
) = NULL
;
2789 static inline void free_zone_pagesets(int cpu
)
2793 for_each_zone(zone
) {
2794 struct per_cpu_pageset
*pset
= zone_pcp(zone
, cpu
);
2796 /* Free per_cpu_pageset if it is slab allocated */
2797 if (pset
!= &boot_pageset
[cpu
])
2799 zone_pcp(zone
, cpu
) = NULL
;
2803 static int __cpuinit
pageset_cpuup_callback(struct notifier_block
*nfb
,
2804 unsigned long action
,
2807 int cpu
= (long)hcpu
;
2808 int ret
= NOTIFY_OK
;
2811 case CPU_UP_PREPARE
:
2812 case CPU_UP_PREPARE_FROZEN
:
2813 if (process_zones(cpu
))
2816 case CPU_UP_CANCELED
:
2817 case CPU_UP_CANCELED_FROZEN
:
2819 case CPU_DEAD_FROZEN
:
2820 free_zone_pagesets(cpu
);
2828 static struct notifier_block __cpuinitdata pageset_notifier
=
2829 { &pageset_cpuup_callback
, NULL
, 0 };
2831 void __init
setup_per_cpu_pageset(void)
2835 /* Initialize per_cpu_pageset for cpu 0.
2836 * A cpuup callback will do this for every cpu
2837 * as it comes online
2839 err
= process_zones(smp_processor_id());
2841 register_cpu_notifier(&pageset_notifier
);
2846 static noinline __init_refok
2847 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
2850 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
2854 * The per-page waitqueue mechanism uses hashed waitqueues
2857 zone
->wait_table_hash_nr_entries
=
2858 wait_table_hash_nr_entries(zone_size_pages
);
2859 zone
->wait_table_bits
=
2860 wait_table_bits(zone
->wait_table_hash_nr_entries
);
2861 alloc_size
= zone
->wait_table_hash_nr_entries
2862 * sizeof(wait_queue_head_t
);
2864 if (!slab_is_available()) {
2865 zone
->wait_table
= (wait_queue_head_t
*)
2866 alloc_bootmem_node(pgdat
, alloc_size
);
2869 * This case means that a zone whose size was 0 gets new memory
2870 * via memory hot-add.
2871 * But it may be the case that a new node was hot-added. In
2872 * this case vmalloc() will not be able to use this new node's
2873 * memory - this wait_table must be initialized to use this new
2874 * node itself as well.
2875 * To use this new node's memory, further consideration will be
2878 zone
->wait_table
= vmalloc(alloc_size
);
2880 if (!zone
->wait_table
)
2883 for(i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
2884 init_waitqueue_head(zone
->wait_table
+ i
);
2889 static __meminit
void zone_pcp_init(struct zone
*zone
)
2892 unsigned long batch
= zone_batchsize(zone
);
2894 for (cpu
= 0; cpu
< NR_CPUS
; cpu
++) {
2896 /* Early boot. Slab allocator not functional yet */
2897 zone_pcp(zone
, cpu
) = &boot_pageset
[cpu
];
2898 setup_pageset(&boot_pageset
[cpu
],0);
2900 setup_pageset(zone_pcp(zone
,cpu
), batch
);
2903 if (zone
->present_pages
)
2904 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%lu\n",
2905 zone
->name
, zone
->present_pages
, batch
);
2908 __meminit
int init_currently_empty_zone(struct zone
*zone
,
2909 unsigned long zone_start_pfn
,
2911 enum memmap_context context
)
2913 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
2915 ret
= zone_wait_table_init(zone
, size
);
2918 pgdat
->nr_zones
= zone_idx(zone
) + 1;
2920 zone
->zone_start_pfn
= zone_start_pfn
;
2922 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
2923 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
2925 (unsigned long)zone_idx(zone
),
2926 zone_start_pfn
, (zone_start_pfn
+ size
));
2928 zone_init_free_lists(zone
);
2933 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
2935 * Basic iterator support. Return the first range of PFNs for a node
2936 * Note: nid == MAX_NUMNODES returns first region regardless of node
2938 static int __meminit
first_active_region_index_in_nid(int nid
)
2942 for (i
= 0; i
< nr_nodemap_entries
; i
++)
2943 if (nid
== MAX_NUMNODES
|| early_node_map
[i
].nid
== nid
)
2950 * Basic iterator support. Return the next active range of PFNs for a node
2951 * Note: nid == MAX_NUMNODES returns next region regardless of node
2953 static int __meminit
next_active_region_index_in_nid(int index
, int nid
)
2955 for (index
= index
+ 1; index
< nr_nodemap_entries
; index
++)
2956 if (nid
== MAX_NUMNODES
|| early_node_map
[index
].nid
== nid
)
2962 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
2964 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
2965 * Architectures may implement their own version but if add_active_range()
2966 * was used and there are no special requirements, this is a convenient
2969 int __meminit
early_pfn_to_nid(unsigned long pfn
)
2973 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
2974 unsigned long start_pfn
= early_node_map
[i
].start_pfn
;
2975 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
2977 if (start_pfn
<= pfn
&& pfn
< end_pfn
)
2978 return early_node_map
[i
].nid
;
2983 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
2985 /* Basic iterator support to walk early_node_map[] */
2986 #define for_each_active_range_index_in_nid(i, nid) \
2987 for (i = first_active_region_index_in_nid(nid); i != -1; \
2988 i = next_active_region_index_in_nid(i, nid))
2991 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
2992 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
2993 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
2995 * If an architecture guarantees that all ranges registered with
2996 * add_active_ranges() contain no holes and may be freed, this
2997 * this function may be used instead of calling free_bootmem() manually.
2999 void __init
free_bootmem_with_active_regions(int nid
,
3000 unsigned long max_low_pfn
)
3004 for_each_active_range_index_in_nid(i
, nid
) {
3005 unsigned long size_pages
= 0;
3006 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
3008 if (early_node_map
[i
].start_pfn
>= max_low_pfn
)
3011 if (end_pfn
> max_low_pfn
)
3012 end_pfn
= max_low_pfn
;
3014 size_pages
= end_pfn
- early_node_map
[i
].start_pfn
;
3015 free_bootmem_node(NODE_DATA(early_node_map
[i
].nid
),
3016 PFN_PHYS(early_node_map
[i
].start_pfn
),
3017 size_pages
<< PAGE_SHIFT
);
3021 void __init
work_with_active_regions(int nid
, work_fn_t work_fn
, void *data
)
3026 for_each_active_range_index_in_nid(i
, nid
) {
3027 ret
= work_fn(early_node_map
[i
].start_pfn
,
3028 early_node_map
[i
].end_pfn
, data
);
3034 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3035 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3037 * If an architecture guarantees that all ranges registered with
3038 * add_active_ranges() contain no holes and may be freed, this
3039 * function may be used instead of calling memory_present() manually.
3041 void __init
sparse_memory_present_with_active_regions(int nid
)
3045 for_each_active_range_index_in_nid(i
, nid
)
3046 memory_present(early_node_map
[i
].nid
,
3047 early_node_map
[i
].start_pfn
,
3048 early_node_map
[i
].end_pfn
);
3052 * push_node_boundaries - Push node boundaries to at least the requested boundary
3053 * @nid: The nid of the node to push the boundary for
3054 * @start_pfn: The start pfn of the node
3055 * @end_pfn: The end pfn of the node
3057 * In reserve-based hot-add, mem_map is allocated that is unused until hotadd
3058 * time. Specifically, on x86_64, SRAT will report ranges that can potentially
3059 * be hotplugged even though no physical memory exists. This function allows
3060 * an arch to push out the node boundaries so mem_map is allocated that can
3063 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
3064 void __init
push_node_boundaries(unsigned int nid
,
3065 unsigned long start_pfn
, unsigned long end_pfn
)
3067 mminit_dprintk(MMINIT_TRACE
, "zoneboundary",
3068 "Entering push_node_boundaries(%u, %lu, %lu)\n",
3069 nid
, start_pfn
, end_pfn
);
3071 /* Initialise the boundary for this node if necessary */
3072 if (node_boundary_end_pfn
[nid
] == 0)
3073 node_boundary_start_pfn
[nid
] = -1UL;
3075 /* Update the boundaries */
3076 if (node_boundary_start_pfn
[nid
] > start_pfn
)
3077 node_boundary_start_pfn
[nid
] = start_pfn
;
3078 if (node_boundary_end_pfn
[nid
] < end_pfn
)
3079 node_boundary_end_pfn
[nid
] = end_pfn
;
3082 /* If necessary, push the node boundary out for reserve hotadd */
3083 static void __meminit
account_node_boundary(unsigned int nid
,
3084 unsigned long *start_pfn
, unsigned long *end_pfn
)
3086 mminit_dprintk(MMINIT_TRACE
, "zoneboundary",
3087 "Entering account_node_boundary(%u, %lu, %lu)\n",
3088 nid
, *start_pfn
, *end_pfn
);
3090 /* Return if boundary information has not been provided */
3091 if (node_boundary_end_pfn
[nid
] == 0)
3094 /* Check the boundaries and update if necessary */
3095 if (node_boundary_start_pfn
[nid
] < *start_pfn
)
3096 *start_pfn
= node_boundary_start_pfn
[nid
];
3097 if (node_boundary_end_pfn
[nid
] > *end_pfn
)
3098 *end_pfn
= node_boundary_end_pfn
[nid
];
3101 void __init
push_node_boundaries(unsigned int nid
,
3102 unsigned long start_pfn
, unsigned long end_pfn
) {}
3104 static void __meminit
account_node_boundary(unsigned int nid
,
3105 unsigned long *start_pfn
, unsigned long *end_pfn
) {}
3110 * get_pfn_range_for_nid - Return the start and end page frames for a node
3111 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
3112 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
3113 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
3115 * It returns the start and end page frame of a node based on information
3116 * provided by an arch calling add_active_range(). If called for a node
3117 * with no available memory, a warning is printed and the start and end
3120 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
3121 unsigned long *start_pfn
, unsigned long *end_pfn
)
3127 for_each_active_range_index_in_nid(i
, nid
) {
3128 *start_pfn
= min(*start_pfn
, early_node_map
[i
].start_pfn
);
3129 *end_pfn
= max(*end_pfn
, early_node_map
[i
].end_pfn
);
3132 if (*start_pfn
== -1UL)
3135 /* Push the node boundaries out if requested */
3136 account_node_boundary(nid
, start_pfn
, end_pfn
);
3140 * This finds a zone that can be used for ZONE_MOVABLE pages. The
3141 * assumption is made that zones within a node are ordered in monotonic
3142 * increasing memory addresses so that the "highest" populated zone is used
3144 static void __init
find_usable_zone_for_movable(void)
3147 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
3148 if (zone_index
== ZONE_MOVABLE
)
3151 if (arch_zone_highest_possible_pfn
[zone_index
] >
3152 arch_zone_lowest_possible_pfn
[zone_index
])
3156 VM_BUG_ON(zone_index
== -1);
3157 movable_zone
= zone_index
;
3161 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
3162 * because it is sized independant of architecture. Unlike the other zones,
3163 * the starting point for ZONE_MOVABLE is not fixed. It may be different
3164 * in each node depending on the size of each node and how evenly kernelcore
3165 * is distributed. This helper function adjusts the zone ranges
3166 * provided by the architecture for a given node by using the end of the
3167 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
3168 * zones within a node are in order of monotonic increases memory addresses
3170 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
3171 unsigned long zone_type
,
3172 unsigned long node_start_pfn
,
3173 unsigned long node_end_pfn
,
3174 unsigned long *zone_start_pfn
,
3175 unsigned long *zone_end_pfn
)
3177 /* Only adjust if ZONE_MOVABLE is on this node */
3178 if (zone_movable_pfn
[nid
]) {
3179 /* Size ZONE_MOVABLE */
3180 if (zone_type
== ZONE_MOVABLE
) {
3181 *zone_start_pfn
= zone_movable_pfn
[nid
];
3182 *zone_end_pfn
= min(node_end_pfn
,
3183 arch_zone_highest_possible_pfn
[movable_zone
]);
3185 /* Adjust for ZONE_MOVABLE starting within this range */
3186 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
3187 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
3188 *zone_end_pfn
= zone_movable_pfn
[nid
];
3190 /* Check if this whole range is within ZONE_MOVABLE */
3191 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
3192 *zone_start_pfn
= *zone_end_pfn
;
3197 * Return the number of pages a zone spans in a node, including holes
3198 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
3200 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3201 unsigned long zone_type
,
3202 unsigned long *ignored
)
3204 unsigned long node_start_pfn
, node_end_pfn
;
3205 unsigned long zone_start_pfn
, zone_end_pfn
;
3207 /* Get the start and end of the node and zone */
3208 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3209 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
3210 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
3211 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3212 node_start_pfn
, node_end_pfn
,
3213 &zone_start_pfn
, &zone_end_pfn
);
3215 /* Check that this node has pages within the zone's required range */
3216 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
3219 /* Move the zone boundaries inside the node if necessary */
3220 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
3221 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
3223 /* Return the spanned pages */
3224 return zone_end_pfn
- zone_start_pfn
;
3228 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
3229 * then all holes in the requested range will be accounted for.
3231 static unsigned long __meminit
__absent_pages_in_range(int nid
,
3232 unsigned long range_start_pfn
,
3233 unsigned long range_end_pfn
)
3236 unsigned long prev_end_pfn
= 0, hole_pages
= 0;
3237 unsigned long start_pfn
;
3239 /* Find the end_pfn of the first active range of pfns in the node */
3240 i
= first_active_region_index_in_nid(nid
);
3244 prev_end_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3246 /* Account for ranges before physical memory on this node */
3247 if (early_node_map
[i
].start_pfn
> range_start_pfn
)
3248 hole_pages
= prev_end_pfn
- range_start_pfn
;
3250 /* Find all holes for the zone within the node */
3251 for (; i
!= -1; i
= next_active_region_index_in_nid(i
, nid
)) {
3253 /* No need to continue if prev_end_pfn is outside the zone */
3254 if (prev_end_pfn
>= range_end_pfn
)
3257 /* Make sure the end of the zone is not within the hole */
3258 start_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3259 prev_end_pfn
= max(prev_end_pfn
, range_start_pfn
);
3261 /* Update the hole size cound and move on */
3262 if (start_pfn
> range_start_pfn
) {
3263 BUG_ON(prev_end_pfn
> start_pfn
);
3264 hole_pages
+= start_pfn
- prev_end_pfn
;
3266 prev_end_pfn
= early_node_map
[i
].end_pfn
;
3269 /* Account for ranges past physical memory on this node */
3270 if (range_end_pfn
> prev_end_pfn
)
3271 hole_pages
+= range_end_pfn
-
3272 max(range_start_pfn
, prev_end_pfn
);
3278 * absent_pages_in_range - Return number of page frames in holes within a range
3279 * @start_pfn: The start PFN to start searching for holes
3280 * @end_pfn: The end PFN to stop searching for holes
3282 * It returns the number of pages frames in memory holes within a range.
3284 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
3285 unsigned long end_pfn
)
3287 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
3290 /* Return the number of page frames in holes in a zone on a node */
3291 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
3292 unsigned long zone_type
,
3293 unsigned long *ignored
)
3295 unsigned long node_start_pfn
, node_end_pfn
;
3296 unsigned long zone_start_pfn
, zone_end_pfn
;
3298 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3299 zone_start_pfn
= max(arch_zone_lowest_possible_pfn
[zone_type
],
3301 zone_end_pfn
= min(arch_zone_highest_possible_pfn
[zone_type
],
3304 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3305 node_start_pfn
, node_end_pfn
,
3306 &zone_start_pfn
, &zone_end_pfn
);
3307 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
3311 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3312 unsigned long zone_type
,
3313 unsigned long *zones_size
)
3315 return zones_size
[zone_type
];
3318 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
3319 unsigned long zone_type
,
3320 unsigned long *zholes_size
)
3325 return zholes_size
[zone_type
];
3330 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
3331 unsigned long *zones_size
, unsigned long *zholes_size
)
3333 unsigned long realtotalpages
, totalpages
= 0;
3336 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3337 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
3339 pgdat
->node_spanned_pages
= totalpages
;
3341 realtotalpages
= totalpages
;
3342 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3344 zone_absent_pages_in_node(pgdat
->node_id
, i
,
3346 pgdat
->node_present_pages
= realtotalpages
;
3347 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
3351 #ifndef CONFIG_SPARSEMEM
3353 * Calculate the size of the zone->blockflags rounded to an unsigned long
3354 * Start by making sure zonesize is a multiple of pageblock_order by rounding
3355 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
3356 * round what is now in bits to nearest long in bits, then return it in
3359 static unsigned long __init
usemap_size(unsigned long zonesize
)
3361 unsigned long usemapsize
;
3363 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
3364 usemapsize
= usemapsize
>> pageblock_order
;
3365 usemapsize
*= NR_PAGEBLOCK_BITS
;
3366 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
3368 return usemapsize
/ 8;
3371 static void __init
setup_usemap(struct pglist_data
*pgdat
,
3372 struct zone
*zone
, unsigned long zonesize
)
3374 unsigned long usemapsize
= usemap_size(zonesize
);
3375 zone
->pageblock_flags
= NULL
;
3377 zone
->pageblock_flags
= alloc_bootmem_node(pgdat
, usemapsize
);
3380 static void inline setup_usemap(struct pglist_data
*pgdat
,
3381 struct zone
*zone
, unsigned long zonesize
) {}
3382 #endif /* CONFIG_SPARSEMEM */
3384 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3386 /* Return a sensible default order for the pageblock size. */
3387 static inline int pageblock_default_order(void)
3389 if (HPAGE_SHIFT
> PAGE_SHIFT
)
3390 return HUGETLB_PAGE_ORDER
;
3395 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
3396 static inline void __init
set_pageblock_order(unsigned int order
)
3398 /* Check that pageblock_nr_pages has not already been setup */
3399 if (pageblock_order
)
3403 * Assume the largest contiguous order of interest is a huge page.
3404 * This value may be variable depending on boot parameters on IA64
3406 pageblock_order
= order
;
3408 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3411 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
3412 * and pageblock_default_order() are unused as pageblock_order is set
3413 * at compile-time. See include/linux/pageblock-flags.h for the values of
3414 * pageblock_order based on the kernel config
3416 static inline int pageblock_default_order(unsigned int order
)
3420 #define set_pageblock_order(x) do {} while (0)
3422 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3425 * Set up the zone data structures:
3426 * - mark all pages reserved
3427 * - mark all memory queues empty
3428 * - clear the memory bitmaps
3430 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
,
3431 unsigned long *zones_size
, unsigned long *zholes_size
)
3434 int nid
= pgdat
->node_id
;
3435 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
3438 pgdat_resize_init(pgdat
);
3439 pgdat
->nr_zones
= 0;
3440 init_waitqueue_head(&pgdat
->kswapd_wait
);
3441 pgdat
->kswapd_max_order
= 0;
3442 pgdat_page_cgroup_init(pgdat
);
3444 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
3445 struct zone
*zone
= pgdat
->node_zones
+ j
;
3446 unsigned long size
, realsize
, memmap_pages
;
3449 size
= zone_spanned_pages_in_node(nid
, j
, zones_size
);
3450 realsize
= size
- zone_absent_pages_in_node(nid
, j
,
3454 * Adjust realsize so that it accounts for how much memory
3455 * is used by this zone for memmap. This affects the watermark
3456 * and per-cpu initialisations
3459 PAGE_ALIGN(size
* sizeof(struct page
)) >> PAGE_SHIFT
;
3460 if (realsize
>= memmap_pages
) {
3461 realsize
-= memmap_pages
;
3464 " %s zone: %lu pages used for memmap\n",
3465 zone_names
[j
], memmap_pages
);
3468 " %s zone: %lu pages exceeds realsize %lu\n",
3469 zone_names
[j
], memmap_pages
, realsize
);
3471 /* Account for reserved pages */
3472 if (j
== 0 && realsize
> dma_reserve
) {
3473 realsize
-= dma_reserve
;
3474 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
3475 zone_names
[0], dma_reserve
);
3478 if (!is_highmem_idx(j
))
3479 nr_kernel_pages
+= realsize
;
3480 nr_all_pages
+= realsize
;
3482 zone
->spanned_pages
= size
;
3483 zone
->present_pages
= realsize
;
3486 zone
->min_unmapped_pages
= (realsize
*sysctl_min_unmapped_ratio
)
3488 zone
->min_slab_pages
= (realsize
* sysctl_min_slab_ratio
) / 100;
3490 zone
->name
= zone_names
[j
];
3491 spin_lock_init(&zone
->lock
);
3492 spin_lock_init(&zone
->lru_lock
);
3493 zone_seqlock_init(zone
);
3494 zone
->zone_pgdat
= pgdat
;
3496 zone
->prev_priority
= DEF_PRIORITY
;
3498 zone_pcp_init(zone
);
3500 INIT_LIST_HEAD(&zone
->lru
[l
].list
);
3501 zone
->lru
[l
].nr_scan
= 0;
3503 zone
->recent_rotated
[0] = 0;
3504 zone
->recent_rotated
[1] = 0;
3505 zone
->recent_scanned
[0] = 0;
3506 zone
->recent_scanned
[1] = 0;
3507 zap_zone_vm_stats(zone
);
3512 set_pageblock_order(pageblock_default_order());
3513 setup_usemap(pgdat
, zone
, size
);
3514 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
3515 size
, MEMMAP_EARLY
);
3517 memmap_init(size
, nid
, j
, zone_start_pfn
);
3518 zone_start_pfn
+= size
;
3522 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
3524 /* Skip empty nodes */
3525 if (!pgdat
->node_spanned_pages
)
3528 #ifdef CONFIG_FLAT_NODE_MEM_MAP
3529 /* ia64 gets its own node_mem_map, before this, without bootmem */
3530 if (!pgdat
->node_mem_map
) {
3531 unsigned long size
, start
, end
;
3535 * The zone's endpoints aren't required to be MAX_ORDER
3536 * aligned but the node_mem_map endpoints must be in order
3537 * for the buddy allocator to function correctly.
3539 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
3540 end
= pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
3541 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
3542 size
= (end
- start
) * sizeof(struct page
);
3543 map
= alloc_remap(pgdat
->node_id
, size
);
3545 map
= alloc_bootmem_node(pgdat
, size
);
3546 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
3548 #ifndef CONFIG_NEED_MULTIPLE_NODES
3550 * With no DISCONTIG, the global mem_map is just set as node 0's
3552 if (pgdat
== NODE_DATA(0)) {
3553 mem_map
= NODE_DATA(0)->node_mem_map
;
3554 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3555 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
3556 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
3557 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
3560 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
3563 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
3564 unsigned long node_start_pfn
, unsigned long *zholes_size
)
3566 pg_data_t
*pgdat
= NODE_DATA(nid
);
3568 pgdat
->node_id
= nid
;
3569 pgdat
->node_start_pfn
= node_start_pfn
;
3570 calculate_node_totalpages(pgdat
, zones_size
, zholes_size
);
3572 alloc_node_mem_map(pgdat
);
3573 #ifdef CONFIG_FLAT_NODE_MEM_MAP
3574 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
3575 nid
, (unsigned long)pgdat
,
3576 (unsigned long)pgdat
->node_mem_map
);
3579 free_area_init_core(pgdat
, zones_size
, zholes_size
);
3582 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3584 #if MAX_NUMNODES > 1
3586 * Figure out the number of possible node ids.
3588 static void __init
setup_nr_node_ids(void)
3591 unsigned int highest
= 0;
3593 for_each_node_mask(node
, node_possible_map
)
3595 nr_node_ids
= highest
+ 1;
3598 static inline void setup_nr_node_ids(void)
3604 * add_active_range - Register a range of PFNs backed by physical memory
3605 * @nid: The node ID the range resides on
3606 * @start_pfn: The start PFN of the available physical memory
3607 * @end_pfn: The end PFN of the available physical memory
3609 * These ranges are stored in an early_node_map[] and later used by
3610 * free_area_init_nodes() to calculate zone sizes and holes. If the
3611 * range spans a memory hole, it is up to the architecture to ensure
3612 * the memory is not freed by the bootmem allocator. If possible
3613 * the range being registered will be merged with existing ranges.
3615 void __init
add_active_range(unsigned int nid
, unsigned long start_pfn
,
3616 unsigned long end_pfn
)
3620 mminit_dprintk(MMINIT_TRACE
, "memory_register",
3621 "Entering add_active_range(%d, %#lx, %#lx) "
3622 "%d entries of %d used\n",
3623 nid
, start_pfn
, end_pfn
,
3624 nr_nodemap_entries
, MAX_ACTIVE_REGIONS
);
3626 mminit_validate_memmodel_limits(&start_pfn
, &end_pfn
);
3628 /* Merge with existing active regions if possible */
3629 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
3630 if (early_node_map
[i
].nid
!= nid
)
3633 /* Skip if an existing region covers this new one */
3634 if (start_pfn
>= early_node_map
[i
].start_pfn
&&
3635 end_pfn
<= early_node_map
[i
].end_pfn
)
3638 /* Merge forward if suitable */
3639 if (start_pfn
<= early_node_map
[i
].end_pfn
&&
3640 end_pfn
> early_node_map
[i
].end_pfn
) {
3641 early_node_map
[i
].end_pfn
= end_pfn
;
3645 /* Merge backward if suitable */
3646 if (start_pfn
< early_node_map
[i
].end_pfn
&&
3647 end_pfn
>= early_node_map
[i
].start_pfn
) {
3648 early_node_map
[i
].start_pfn
= start_pfn
;
3653 /* Check that early_node_map is large enough */
3654 if (i
>= MAX_ACTIVE_REGIONS
) {
3655 printk(KERN_CRIT
"More than %d memory regions, truncating\n",
3656 MAX_ACTIVE_REGIONS
);
3660 early_node_map
[i
].nid
= nid
;
3661 early_node_map
[i
].start_pfn
= start_pfn
;
3662 early_node_map
[i
].end_pfn
= end_pfn
;
3663 nr_nodemap_entries
= i
+ 1;
3667 * remove_active_range - Shrink an existing registered range of PFNs
3668 * @nid: The node id the range is on that should be shrunk
3669 * @start_pfn: The new PFN of the range
3670 * @end_pfn: The new PFN of the range
3672 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
3673 * The map is kept near the end physical page range that has already been
3674 * registered. This function allows an arch to shrink an existing registered
3677 void __init
remove_active_range(unsigned int nid
, unsigned long start_pfn
,
3678 unsigned long end_pfn
)
3683 printk(KERN_DEBUG
"remove_active_range (%d, %lu, %lu)\n",
3684 nid
, start_pfn
, end_pfn
);
3686 /* Find the old active region end and shrink */
3687 for_each_active_range_index_in_nid(i
, nid
) {
3688 if (early_node_map
[i
].start_pfn
>= start_pfn
&&
3689 early_node_map
[i
].end_pfn
<= end_pfn
) {
3691 early_node_map
[i
].start_pfn
= 0;
3692 early_node_map
[i
].end_pfn
= 0;
3696 if (early_node_map
[i
].start_pfn
< start_pfn
&&
3697 early_node_map
[i
].end_pfn
> start_pfn
) {
3698 unsigned long temp_end_pfn
= early_node_map
[i
].end_pfn
;
3699 early_node_map
[i
].end_pfn
= start_pfn
;
3700 if (temp_end_pfn
> end_pfn
)
3701 add_active_range(nid
, end_pfn
, temp_end_pfn
);
3704 if (early_node_map
[i
].start_pfn
>= start_pfn
&&
3705 early_node_map
[i
].end_pfn
> end_pfn
&&
3706 early_node_map
[i
].start_pfn
< end_pfn
) {
3707 early_node_map
[i
].start_pfn
= end_pfn
;
3715 /* remove the blank ones */
3716 for (i
= nr_nodemap_entries
- 1; i
> 0; i
--) {
3717 if (early_node_map
[i
].nid
!= nid
)
3719 if (early_node_map
[i
].end_pfn
)
3721 /* we found it, get rid of it */
3722 for (j
= i
; j
< nr_nodemap_entries
- 1; j
++)
3723 memcpy(&early_node_map
[j
], &early_node_map
[j
+1],
3724 sizeof(early_node_map
[j
]));
3725 j
= nr_nodemap_entries
- 1;
3726 memset(&early_node_map
[j
], 0, sizeof(early_node_map
[j
]));
3727 nr_nodemap_entries
--;
3732 * remove_all_active_ranges - Remove all currently registered regions
3734 * During discovery, it may be found that a table like SRAT is invalid
3735 * and an alternative discovery method must be used. This function removes
3736 * all currently registered regions.
3738 void __init
remove_all_active_ranges(void)
3740 memset(early_node_map
, 0, sizeof(early_node_map
));
3741 nr_nodemap_entries
= 0;
3742 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
3743 memset(node_boundary_start_pfn
, 0, sizeof(node_boundary_start_pfn
));
3744 memset(node_boundary_end_pfn
, 0, sizeof(node_boundary_end_pfn
));
3745 #endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
3748 /* Compare two active node_active_regions */
3749 static int __init
cmp_node_active_region(const void *a
, const void *b
)
3751 struct node_active_region
*arange
= (struct node_active_region
*)a
;
3752 struct node_active_region
*brange
= (struct node_active_region
*)b
;
3754 /* Done this way to avoid overflows */
3755 if (arange
->start_pfn
> brange
->start_pfn
)
3757 if (arange
->start_pfn
< brange
->start_pfn
)
3763 /* sort the node_map by start_pfn */
3764 static void __init
sort_node_map(void)
3766 sort(early_node_map
, (size_t)nr_nodemap_entries
,
3767 sizeof(struct node_active_region
),
3768 cmp_node_active_region
, NULL
);
3771 /* Find the lowest pfn for a node */
3772 static unsigned long __init
find_min_pfn_for_node(int nid
)
3775 unsigned long min_pfn
= ULONG_MAX
;
3777 /* Assuming a sorted map, the first range found has the starting pfn */
3778 for_each_active_range_index_in_nid(i
, nid
)
3779 min_pfn
= min(min_pfn
, early_node_map
[i
].start_pfn
);
3781 if (min_pfn
== ULONG_MAX
) {
3783 "Could not find start_pfn for node %d\n", nid
);
3791 * find_min_pfn_with_active_regions - Find the minimum PFN registered
3793 * It returns the minimum PFN based on information provided via
3794 * add_active_range().
3796 unsigned long __init
find_min_pfn_with_active_regions(void)
3798 return find_min_pfn_for_node(MAX_NUMNODES
);
3802 * early_calculate_totalpages()
3803 * Sum pages in active regions for movable zone.
3804 * Populate N_HIGH_MEMORY for calculating usable_nodes.
3806 static unsigned long __init
early_calculate_totalpages(void)
3809 unsigned long totalpages
= 0;
3811 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
3812 unsigned long pages
= early_node_map
[i
].end_pfn
-
3813 early_node_map
[i
].start_pfn
;
3814 totalpages
+= pages
;
3816 node_set_state(early_node_map
[i
].nid
, N_HIGH_MEMORY
);
3822 * Find the PFN the Movable zone begins in each node. Kernel memory
3823 * is spread evenly between nodes as long as the nodes have enough
3824 * memory. When they don't, some nodes will have more kernelcore than
3827 static void __init
find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn
)
3830 unsigned long usable_startpfn
;
3831 unsigned long kernelcore_node
, kernelcore_remaining
;
3832 unsigned long totalpages
= early_calculate_totalpages();
3833 int usable_nodes
= nodes_weight(node_states
[N_HIGH_MEMORY
]);
3836 * If movablecore was specified, calculate what size of
3837 * kernelcore that corresponds so that memory usable for
3838 * any allocation type is evenly spread. If both kernelcore
3839 * and movablecore are specified, then the value of kernelcore
3840 * will be used for required_kernelcore if it's greater than
3841 * what movablecore would have allowed.
3843 if (required_movablecore
) {
3844 unsigned long corepages
;
3847 * Round-up so that ZONE_MOVABLE is at least as large as what
3848 * was requested by the user
3850 required_movablecore
=
3851 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
3852 corepages
= totalpages
- required_movablecore
;
3854 required_kernelcore
= max(required_kernelcore
, corepages
);
3857 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
3858 if (!required_kernelcore
)
3861 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
3862 find_usable_zone_for_movable();
3863 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
3866 /* Spread kernelcore memory as evenly as possible throughout nodes */
3867 kernelcore_node
= required_kernelcore
/ usable_nodes
;
3868 for_each_node_state(nid
, N_HIGH_MEMORY
) {
3870 * Recalculate kernelcore_node if the division per node
3871 * now exceeds what is necessary to satisfy the requested
3872 * amount of memory for the kernel
3874 if (required_kernelcore
< kernelcore_node
)
3875 kernelcore_node
= required_kernelcore
/ usable_nodes
;
3878 * As the map is walked, we track how much memory is usable
3879 * by the kernel using kernelcore_remaining. When it is
3880 * 0, the rest of the node is usable by ZONE_MOVABLE
3882 kernelcore_remaining
= kernelcore_node
;
3884 /* Go through each range of PFNs within this node */
3885 for_each_active_range_index_in_nid(i
, nid
) {
3886 unsigned long start_pfn
, end_pfn
;
3887 unsigned long size_pages
;
3889 start_pfn
= max(early_node_map
[i
].start_pfn
,
3890 zone_movable_pfn
[nid
]);
3891 end_pfn
= early_node_map
[i
].end_pfn
;
3892 if (start_pfn
>= end_pfn
)
3895 /* Account for what is only usable for kernelcore */
3896 if (start_pfn
< usable_startpfn
) {
3897 unsigned long kernel_pages
;
3898 kernel_pages
= min(end_pfn
, usable_startpfn
)
3901 kernelcore_remaining
-= min(kernel_pages
,
3902 kernelcore_remaining
);
3903 required_kernelcore
-= min(kernel_pages
,
3904 required_kernelcore
);
3906 /* Continue if range is now fully accounted */
3907 if (end_pfn
<= usable_startpfn
) {
3910 * Push zone_movable_pfn to the end so
3911 * that if we have to rebalance
3912 * kernelcore across nodes, we will
3913 * not double account here
3915 zone_movable_pfn
[nid
] = end_pfn
;
3918 start_pfn
= usable_startpfn
;
3922 * The usable PFN range for ZONE_MOVABLE is from
3923 * start_pfn->end_pfn. Calculate size_pages as the
3924 * number of pages used as kernelcore
3926 size_pages
= end_pfn
- start_pfn
;
3927 if (size_pages
> kernelcore_remaining
)
3928 size_pages
= kernelcore_remaining
;
3929 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
3932 * Some kernelcore has been met, update counts and
3933 * break if the kernelcore for this node has been
3936 required_kernelcore
-= min(required_kernelcore
,
3938 kernelcore_remaining
-= size_pages
;
3939 if (!kernelcore_remaining
)
3945 * If there is still required_kernelcore, we do another pass with one
3946 * less node in the count. This will push zone_movable_pfn[nid] further
3947 * along on the nodes that still have memory until kernelcore is
3951 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
3954 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
3955 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
3956 zone_movable_pfn
[nid
] =
3957 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
3960 /* Any regular memory on that node ? */
3961 static void check_for_regular_memory(pg_data_t
*pgdat
)
3963 #ifdef CONFIG_HIGHMEM
3964 enum zone_type zone_type
;
3966 for (zone_type
= 0; zone_type
<= ZONE_NORMAL
; zone_type
++) {
3967 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
3968 if (zone
->present_pages
)
3969 node_set_state(zone_to_nid(zone
), N_NORMAL_MEMORY
);
3975 * free_area_init_nodes - Initialise all pg_data_t and zone data
3976 * @max_zone_pfn: an array of max PFNs for each zone
3978 * This will call free_area_init_node() for each active node in the system.
3979 * Using the page ranges provided by add_active_range(), the size of each
3980 * zone in each node and their holes is calculated. If the maximum PFN
3981 * between two adjacent zones match, it is assumed that the zone is empty.
3982 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
3983 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
3984 * starts where the previous one ended. For example, ZONE_DMA32 starts
3985 * at arch_max_dma_pfn.
3987 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
3992 /* Sort early_node_map as initialisation assumes it is sorted */
3995 /* Record where the zone boundaries are */
3996 memset(arch_zone_lowest_possible_pfn
, 0,
3997 sizeof(arch_zone_lowest_possible_pfn
));
3998 memset(arch_zone_highest_possible_pfn
, 0,
3999 sizeof(arch_zone_highest_possible_pfn
));
4000 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
4001 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
4002 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
4003 if (i
== ZONE_MOVABLE
)
4005 arch_zone_lowest_possible_pfn
[i
] =
4006 arch_zone_highest_possible_pfn
[i
-1];
4007 arch_zone_highest_possible_pfn
[i
] =
4008 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
4010 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
4011 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
4013 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
4014 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
4015 find_zone_movable_pfns_for_nodes(zone_movable_pfn
);
4017 /* Print out the zone ranges */
4018 printk("Zone PFN ranges:\n");
4019 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4020 if (i
== ZONE_MOVABLE
)
4022 printk(" %-8s %0#10lx -> %0#10lx\n",
4024 arch_zone_lowest_possible_pfn
[i
],
4025 arch_zone_highest_possible_pfn
[i
]);
4028 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
4029 printk("Movable zone start PFN for each node\n");
4030 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
4031 if (zone_movable_pfn
[i
])
4032 printk(" Node %d: %lu\n", i
, zone_movable_pfn
[i
]);
4035 /* Print out the early_node_map[] */
4036 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries
);
4037 for (i
= 0; i
< nr_nodemap_entries
; i
++)
4038 printk(" %3d: %0#10lx -> %0#10lx\n", early_node_map
[i
].nid
,
4039 early_node_map
[i
].start_pfn
,
4040 early_node_map
[i
].end_pfn
);
4042 /* Initialise every node */
4043 mminit_verify_pageflags_layout();
4044 setup_nr_node_ids();
4045 for_each_online_node(nid
) {
4046 pg_data_t
*pgdat
= NODE_DATA(nid
);
4047 free_area_init_node(nid
, NULL
,
4048 find_min_pfn_for_node(nid
), NULL
);
4050 /* Any memory on that node */
4051 if (pgdat
->node_present_pages
)
4052 node_set_state(nid
, N_HIGH_MEMORY
);
4053 check_for_regular_memory(pgdat
);
4057 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
4059 unsigned long long coremem
;
4063 coremem
= memparse(p
, &p
);
4064 *core
= coremem
>> PAGE_SHIFT
;
4066 /* Paranoid check that UL is enough for the coremem value */
4067 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
4073 * kernelcore=size sets the amount of memory for use for allocations that
4074 * cannot be reclaimed or migrated.
4076 static int __init
cmdline_parse_kernelcore(char *p
)
4078 return cmdline_parse_core(p
, &required_kernelcore
);
4082 * movablecore=size sets the amount of memory for use for allocations that
4083 * can be reclaimed or migrated.
4085 static int __init
cmdline_parse_movablecore(char *p
)
4087 return cmdline_parse_core(p
, &required_movablecore
);
4090 early_param("kernelcore", cmdline_parse_kernelcore
);
4091 early_param("movablecore", cmdline_parse_movablecore
);
4093 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
4096 * set_dma_reserve - set the specified number of pages reserved in the first zone
4097 * @new_dma_reserve: The number of pages to mark reserved
4099 * The per-cpu batchsize and zone watermarks are determined by present_pages.
4100 * In the DMA zone, a significant percentage may be consumed by kernel image
4101 * and other unfreeable allocations which can skew the watermarks badly. This
4102 * function may optionally be used to account for unfreeable pages in the
4103 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
4104 * smaller per-cpu batchsize.
4106 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
4108 dma_reserve
= new_dma_reserve
;
4111 #ifndef CONFIG_NEED_MULTIPLE_NODES
4112 struct pglist_data __refdata contig_page_data
= { .bdata
= &bootmem_node_data
[0] };
4113 EXPORT_SYMBOL(contig_page_data
);
4116 void __init
free_area_init(unsigned long *zones_size
)
4118 free_area_init_node(0, zones_size
,
4119 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
4122 static int page_alloc_cpu_notify(struct notifier_block
*self
,
4123 unsigned long action
, void *hcpu
)
4125 int cpu
= (unsigned long)hcpu
;
4127 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
4131 * Spill the event counters of the dead processor
4132 * into the current processors event counters.
4133 * This artificially elevates the count of the current
4136 vm_events_fold_cpu(cpu
);
4139 * Zero the differential counters of the dead processor
4140 * so that the vm statistics are consistent.
4142 * This is only okay since the processor is dead and cannot
4143 * race with what we are doing.
4145 refresh_cpu_vm_stats(cpu
);
4150 void __init
page_alloc_init(void)
4152 hotcpu_notifier(page_alloc_cpu_notify
, 0);
4156 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
4157 * or min_free_kbytes changes.
4159 static void calculate_totalreserve_pages(void)
4161 struct pglist_data
*pgdat
;
4162 unsigned long reserve_pages
= 0;
4163 enum zone_type i
, j
;
4165 for_each_online_pgdat(pgdat
) {
4166 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4167 struct zone
*zone
= pgdat
->node_zones
+ i
;
4168 unsigned long max
= 0;
4170 /* Find valid and maximum lowmem_reserve in the zone */
4171 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
4172 if (zone
->lowmem_reserve
[j
] > max
)
4173 max
= zone
->lowmem_reserve
[j
];
4176 /* we treat pages_high as reserved pages. */
4177 max
+= zone
->pages_high
;
4179 if (max
> zone
->present_pages
)
4180 max
= zone
->present_pages
;
4181 reserve_pages
+= max
;
4184 totalreserve_pages
= reserve_pages
;
4188 * setup_per_zone_lowmem_reserve - called whenever
4189 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
4190 * has a correct pages reserved value, so an adequate number of
4191 * pages are left in the zone after a successful __alloc_pages().
4193 static void setup_per_zone_lowmem_reserve(void)
4195 struct pglist_data
*pgdat
;
4196 enum zone_type j
, idx
;
4198 for_each_online_pgdat(pgdat
) {
4199 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4200 struct zone
*zone
= pgdat
->node_zones
+ j
;
4201 unsigned long present_pages
= zone
->present_pages
;
4203 zone
->lowmem_reserve
[j
] = 0;
4207 struct zone
*lower_zone
;
4211 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
4212 sysctl_lowmem_reserve_ratio
[idx
] = 1;
4214 lower_zone
= pgdat
->node_zones
+ idx
;
4215 lower_zone
->lowmem_reserve
[j
] = present_pages
/
4216 sysctl_lowmem_reserve_ratio
[idx
];
4217 present_pages
+= lower_zone
->present_pages
;
4222 /* update totalreserve_pages */
4223 calculate_totalreserve_pages();
4227 * setup_per_zone_pages_min - called when min_free_kbytes changes.
4229 * Ensures that the pages_{min,low,high} values for each zone are set correctly
4230 * with respect to min_free_kbytes.
4232 void setup_per_zone_pages_min(void)
4234 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
4235 unsigned long lowmem_pages
= 0;
4237 unsigned long flags
;
4239 /* Calculate total number of !ZONE_HIGHMEM pages */
4240 for_each_zone(zone
) {
4241 if (!is_highmem(zone
))
4242 lowmem_pages
+= zone
->present_pages
;
4245 for_each_zone(zone
) {
4248 spin_lock_irqsave(&zone
->lock
, flags
);
4249 tmp
= (u64
)pages_min
* zone
->present_pages
;
4250 do_div(tmp
, lowmem_pages
);
4251 if (is_highmem(zone
)) {
4253 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
4254 * need highmem pages, so cap pages_min to a small
4257 * The (pages_high-pages_low) and (pages_low-pages_min)
4258 * deltas controls asynch page reclaim, and so should
4259 * not be capped for highmem.
4263 min_pages
= zone
->present_pages
/ 1024;
4264 if (min_pages
< SWAP_CLUSTER_MAX
)
4265 min_pages
= SWAP_CLUSTER_MAX
;
4266 if (min_pages
> 128)
4268 zone
->pages_min
= min_pages
;
4271 * If it's a lowmem zone, reserve a number of pages
4272 * proportionate to the zone's size.
4274 zone
->pages_min
= tmp
;
4277 zone
->pages_low
= zone
->pages_min
+ (tmp
>> 2);
4278 zone
->pages_high
= zone
->pages_min
+ (tmp
>> 1);
4279 setup_zone_migrate_reserve(zone
);
4280 spin_unlock_irqrestore(&zone
->lock
, flags
);
4283 /* update totalreserve_pages */
4284 calculate_totalreserve_pages();
4288 * setup_per_zone_inactive_ratio - called when min_free_kbytes changes.
4290 * The inactive anon list should be small enough that the VM never has to
4291 * do too much work, but large enough that each inactive page has a chance
4292 * to be referenced again before it is swapped out.
4294 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
4295 * INACTIVE_ANON pages on this zone's LRU, maintained by the
4296 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
4297 * the anonymous pages are kept on the inactive list.
4300 * memory ratio inactive anon
4301 * -------------------------------------
4310 static void setup_per_zone_inactive_ratio(void)
4314 for_each_zone(zone
) {
4315 unsigned int gb
, ratio
;
4317 /* Zone size in gigabytes */
4318 gb
= zone
->present_pages
>> (30 - PAGE_SHIFT
);
4319 ratio
= int_sqrt(10 * gb
);
4323 zone
->inactive_ratio
= ratio
;
4328 * Initialise min_free_kbytes.
4330 * For small machines we want it small (128k min). For large machines
4331 * we want it large (64MB max). But it is not linear, because network
4332 * bandwidth does not increase linearly with machine size. We use
4334 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
4335 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
4351 static int __init
init_per_zone_pages_min(void)
4353 unsigned long lowmem_kbytes
;
4355 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
4357 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
4358 if (min_free_kbytes
< 128)
4359 min_free_kbytes
= 128;
4360 if (min_free_kbytes
> 65536)
4361 min_free_kbytes
= 65536;
4362 setup_per_zone_pages_min();
4363 setup_per_zone_lowmem_reserve();
4364 setup_per_zone_inactive_ratio();
4367 module_init(init_per_zone_pages_min
)
4370 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
4371 * that we can call two helper functions whenever min_free_kbytes
4374 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
4375 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4377 proc_dointvec(table
, write
, file
, buffer
, length
, ppos
);
4379 setup_per_zone_pages_min();
4384 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
4385 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4390 rc
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4395 zone
->min_unmapped_pages
= (zone
->present_pages
*
4396 sysctl_min_unmapped_ratio
) / 100;
4400 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
4401 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4406 rc
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4411 zone
->min_slab_pages
= (zone
->present_pages
*
4412 sysctl_min_slab_ratio
) / 100;
4418 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
4419 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
4420 * whenever sysctl_lowmem_reserve_ratio changes.
4422 * The reserve ratio obviously has absolutely no relation with the
4423 * pages_min watermarks. The lowmem reserve ratio can only make sense
4424 * if in function of the boot time zone sizes.
4426 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
4427 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4429 proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4430 setup_per_zone_lowmem_reserve();
4435 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
4436 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
4437 * can have before it gets flushed back to buddy allocator.
4440 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
4441 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4447 ret
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4448 if (!write
|| (ret
== -EINVAL
))
4450 for_each_zone(zone
) {
4451 for_each_online_cpu(cpu
) {
4453 high
= zone
->present_pages
/ percpu_pagelist_fraction
;
4454 setup_pagelist_highmark(zone_pcp(zone
, cpu
), high
);
4460 int hashdist
= HASHDIST_DEFAULT
;
4463 static int __init
set_hashdist(char *str
)
4467 hashdist
= simple_strtoul(str
, &str
, 0);
4470 __setup("hashdist=", set_hashdist
);
4474 * allocate a large system hash table from bootmem
4475 * - it is assumed that the hash table must contain an exact power-of-2
4476 * quantity of entries
4477 * - limit is the number of hash buckets, not the total allocation size
4479 void *__init
alloc_large_system_hash(const char *tablename
,
4480 unsigned long bucketsize
,
4481 unsigned long numentries
,
4484 unsigned int *_hash_shift
,
4485 unsigned int *_hash_mask
,
4486 unsigned long limit
)
4488 unsigned long long max
= limit
;
4489 unsigned long log2qty
, size
;
4492 /* allow the kernel cmdline to have a say */
4494 /* round applicable memory size up to nearest megabyte */
4495 numentries
= nr_kernel_pages
;
4496 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
4497 numentries
>>= 20 - PAGE_SHIFT
;
4498 numentries
<<= 20 - PAGE_SHIFT
;
4500 /* limit to 1 bucket per 2^scale bytes of low memory */
4501 if (scale
> PAGE_SHIFT
)
4502 numentries
>>= (scale
- PAGE_SHIFT
);
4504 numentries
<<= (PAGE_SHIFT
- scale
);
4506 /* Make sure we've got at least a 0-order allocation.. */
4507 if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
4508 numentries
= PAGE_SIZE
/ bucketsize
;
4510 numentries
= roundup_pow_of_two(numentries
);
4512 /* limit allocation size to 1/16 total memory by default */
4514 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
4515 do_div(max
, bucketsize
);
4518 if (numentries
> max
)
4521 log2qty
= ilog2(numentries
);
4524 size
= bucketsize
<< log2qty
;
4525 if (flags
& HASH_EARLY
)
4526 table
= alloc_bootmem_nopanic(size
);
4528 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
4530 unsigned long order
= get_order(size
);
4531 table
= (void*) __get_free_pages(GFP_ATOMIC
, order
);
4533 * If bucketsize is not a power-of-two, we may free
4534 * some pages at the end of hash table.
4537 unsigned long alloc_end
= (unsigned long)table
+
4538 (PAGE_SIZE
<< order
);
4539 unsigned long used
= (unsigned long)table
+
4541 split_page(virt_to_page(table
), order
);
4542 while (used
< alloc_end
) {
4548 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
4551 panic("Failed to allocate %s hash table\n", tablename
);
4553 printk(KERN_INFO
"%s hash table entries: %d (order: %d, %lu bytes)\n",
4556 ilog2(size
) - PAGE_SHIFT
,
4560 *_hash_shift
= log2qty
;
4562 *_hash_mask
= (1 << log2qty
) - 1;
4567 #ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
4568 struct page
*pfn_to_page(unsigned long pfn
)
4570 return __pfn_to_page(pfn
);
4572 unsigned long page_to_pfn(struct page
*page
)
4574 return __page_to_pfn(page
);
4576 EXPORT_SYMBOL(pfn_to_page
);
4577 EXPORT_SYMBOL(page_to_pfn
);
4578 #endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */
4580 /* Return a pointer to the bitmap storing bits affecting a block of pages */
4581 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
4584 #ifdef CONFIG_SPARSEMEM
4585 return __pfn_to_section(pfn
)->pageblock_flags
;
4587 return zone
->pageblock_flags
;
4588 #endif /* CONFIG_SPARSEMEM */
4591 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
4593 #ifdef CONFIG_SPARSEMEM
4594 pfn
&= (PAGES_PER_SECTION
-1);
4595 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
4597 pfn
= pfn
- zone
->zone_start_pfn
;
4598 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
4599 #endif /* CONFIG_SPARSEMEM */
4603 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4604 * @page: The page within the block of interest
4605 * @start_bitidx: The first bit of interest to retrieve
4606 * @end_bitidx: The last bit of interest
4607 * returns pageblock_bits flags
4609 unsigned long get_pageblock_flags_group(struct page
*page
,
4610 int start_bitidx
, int end_bitidx
)
4613 unsigned long *bitmap
;
4614 unsigned long pfn
, bitidx
;
4615 unsigned long flags
= 0;
4616 unsigned long value
= 1;
4618 zone
= page_zone(page
);
4619 pfn
= page_to_pfn(page
);
4620 bitmap
= get_pageblock_bitmap(zone
, pfn
);
4621 bitidx
= pfn_to_bitidx(zone
, pfn
);
4623 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
4624 if (test_bit(bitidx
+ start_bitidx
, bitmap
))
4631 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
4632 * @page: The page within the block of interest
4633 * @start_bitidx: The first bit of interest
4634 * @end_bitidx: The last bit of interest
4635 * @flags: The flags to set
4637 void set_pageblock_flags_group(struct page
*page
, unsigned long flags
,
4638 int start_bitidx
, int end_bitidx
)
4641 unsigned long *bitmap
;
4642 unsigned long pfn
, bitidx
;
4643 unsigned long value
= 1;
4645 zone
= page_zone(page
);
4646 pfn
= page_to_pfn(page
);
4647 bitmap
= get_pageblock_bitmap(zone
, pfn
);
4648 bitidx
= pfn_to_bitidx(zone
, pfn
);
4649 VM_BUG_ON(pfn
< zone
->zone_start_pfn
);
4650 VM_BUG_ON(pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
);
4652 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
4654 __set_bit(bitidx
+ start_bitidx
, bitmap
);
4656 __clear_bit(bitidx
+ start_bitidx
, bitmap
);
4660 * This is designed as sub function...plz see page_isolation.c also.
4661 * set/clear page block's type to be ISOLATE.
4662 * page allocater never alloc memory from ISOLATE block.
4665 int set_migratetype_isolate(struct page
*page
)
4668 unsigned long flags
;
4671 zone
= page_zone(page
);
4672 spin_lock_irqsave(&zone
->lock
, flags
);
4674 * In future, more migrate types will be able to be isolation target.
4676 if (get_pageblock_migratetype(page
) != MIGRATE_MOVABLE
)
4678 set_pageblock_migratetype(page
, MIGRATE_ISOLATE
);
4679 move_freepages_block(zone
, page
, MIGRATE_ISOLATE
);
4682 spin_unlock_irqrestore(&zone
->lock
, flags
);
4688 void unset_migratetype_isolate(struct page
*page
)
4691 unsigned long flags
;
4692 zone
= page_zone(page
);
4693 spin_lock_irqsave(&zone
->lock
, flags
);
4694 if (get_pageblock_migratetype(page
) != MIGRATE_ISOLATE
)
4696 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4697 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
4699 spin_unlock_irqrestore(&zone
->lock
, flags
);
4702 #ifdef CONFIG_MEMORY_HOTREMOVE
4704 * All pages in the range must be isolated before calling this.
4707 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
4713 unsigned long flags
;
4714 /* find the first valid pfn */
4715 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
4720 zone
= page_zone(pfn_to_page(pfn
));
4721 spin_lock_irqsave(&zone
->lock
, flags
);
4723 while (pfn
< end_pfn
) {
4724 if (!pfn_valid(pfn
)) {
4728 page
= pfn_to_page(pfn
);
4729 BUG_ON(page_count(page
));
4730 BUG_ON(!PageBuddy(page
));
4731 order
= page_order(page
);
4732 #ifdef CONFIG_DEBUG_VM
4733 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
4734 pfn
, 1 << order
, end_pfn
);
4736 list_del(&page
->lru
);
4737 rmv_page_order(page
);
4738 zone
->free_area
[order
].nr_free
--;
4739 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
4741 for (i
= 0; i
< (1 << order
); i
++)
4742 SetPageReserved((page
+i
));
4743 pfn
+= (1 << order
);
4745 spin_unlock_irqrestore(&zone
->lock
, flags
);