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 unsigned long highest_memmap_pfn __read_mostly
;
73 int percpu_pagelist_fraction
;
75 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
76 int pageblock_order __read_mostly
;
79 static void __free_pages_ok(struct page
*page
, unsigned int order
);
82 * results with 256, 32 in the lowmem_reserve sysctl:
83 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
84 * 1G machine -> (16M dma, 784M normal, 224M high)
85 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
86 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
87 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
89 * TBD: should special case ZONE_DMA32 machines here - in those we normally
90 * don't need any ZONE_NORMAL reservation
92 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
93 #ifdef CONFIG_ZONE_DMA
96 #ifdef CONFIG_ZONE_DMA32
105 EXPORT_SYMBOL(totalram_pages
);
107 static char * const zone_names
[MAX_NR_ZONES
] = {
108 #ifdef CONFIG_ZONE_DMA
111 #ifdef CONFIG_ZONE_DMA32
115 #ifdef CONFIG_HIGHMEM
121 int min_free_kbytes
= 1024;
123 unsigned long __meminitdata nr_kernel_pages
;
124 unsigned long __meminitdata nr_all_pages
;
125 static unsigned long __meminitdata dma_reserve
;
127 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
129 * MAX_ACTIVE_REGIONS determines the maximum number of distinct
130 * ranges of memory (RAM) that may be registered with add_active_range().
131 * Ranges passed to add_active_range() will be merged if possible
132 * so the number of times add_active_range() can be called is
133 * related to the number of nodes and the number of holes
135 #ifdef CONFIG_MAX_ACTIVE_REGIONS
136 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */
137 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
139 #if MAX_NUMNODES >= 32
140 /* If there can be many nodes, allow up to 50 holes per node */
141 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
143 /* By default, allow up to 256 distinct regions */
144 #define MAX_ACTIVE_REGIONS 256
148 static struct node_active_region __meminitdata early_node_map
[MAX_ACTIVE_REGIONS
];
149 static int __meminitdata nr_nodemap_entries
;
150 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
151 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
152 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
153 static unsigned long __meminitdata node_boundary_start_pfn
[MAX_NUMNODES
];
154 static unsigned long __meminitdata node_boundary_end_pfn
[MAX_NUMNODES
];
155 #endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
156 static unsigned long __initdata required_kernelcore
;
157 static unsigned long __initdata required_movablecore
;
158 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
160 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
162 EXPORT_SYMBOL(movable_zone
);
163 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
166 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
167 EXPORT_SYMBOL(nr_node_ids
);
170 int page_group_by_mobility_disabled __read_mostly
;
172 static void set_pageblock_migratetype(struct page
*page
, int migratetype
)
174 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
175 PB_migrate
, PB_migrate_end
);
178 #ifdef CONFIG_DEBUG_VM
179 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
183 unsigned long pfn
= page_to_pfn(page
);
186 seq
= zone_span_seqbegin(zone
);
187 if (pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
189 else if (pfn
< zone
->zone_start_pfn
)
191 } while (zone_span_seqretry(zone
, seq
));
196 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
198 if (!pfn_valid_within(page_to_pfn(page
)))
200 if (zone
!= page_zone(page
))
206 * Temporary debugging check for pages not lying within a given zone.
208 static int bad_range(struct zone
*zone
, struct page
*page
)
210 if (page_outside_zone_boundaries(zone
, page
))
212 if (!page_is_consistent(zone
, page
))
218 static inline int bad_range(struct zone
*zone
, struct page
*page
)
224 static void bad_page(struct page
*page
)
226 static unsigned long resume
;
227 static unsigned long nr_shown
;
228 static unsigned long nr_unshown
;
231 * Allow a burst of 60 reports, then keep quiet for that minute;
232 * or allow a steady drip of one report per second.
234 if (nr_shown
== 60) {
235 if (time_before(jiffies
, resume
)) {
241 "BUG: Bad page state: %lu messages suppressed\n",
248 resume
= jiffies
+ 60 * HZ
;
250 printk(KERN_ALERT
"BUG: Bad page state in process %s pfn:%05lx\n",
251 current
->comm
, page_to_pfn(page
));
253 "page:%p flags:%p count:%d mapcount:%d mapping:%p index:%lx\n",
254 page
, (void *)page
->flags
, page_count(page
),
255 page_mapcount(page
), page
->mapping
, page
->index
);
259 /* Leave bad fields for debug, except PageBuddy could make trouble */
260 __ClearPageBuddy(page
);
261 add_taint(TAINT_BAD_PAGE
);
265 * Higher-order pages are called "compound pages". They are structured thusly:
267 * The first PAGE_SIZE page is called the "head page".
269 * The remaining PAGE_SIZE pages are called "tail pages".
271 * All pages have PG_compound set. All pages have their ->private pointing at
272 * the head page (even the head page has this).
274 * The first tail page's ->lru.next holds the address of the compound page's
275 * put_page() function. Its ->lru.prev holds the order of allocation.
276 * This usage means that zero-order pages may not be compound.
279 static void free_compound_page(struct page
*page
)
281 __free_pages_ok(page
, compound_order(page
));
284 void prep_compound_page(struct page
*page
, unsigned long order
)
287 int nr_pages
= 1 << order
;
289 set_compound_page_dtor(page
, free_compound_page
);
290 set_compound_order(page
, order
);
292 for (i
= 1; i
< nr_pages
; i
++) {
293 struct page
*p
= page
+ i
;
296 p
->first_page
= page
;
300 #ifdef CONFIG_HUGETLBFS
301 void prep_compound_gigantic_page(struct page
*page
, unsigned long order
)
304 int nr_pages
= 1 << order
;
305 struct page
*p
= page
+ 1;
307 set_compound_page_dtor(page
, free_compound_page
);
308 set_compound_order(page
, order
);
310 for (i
= 1; i
< nr_pages
; i
++, p
= mem_map_next(p
, page
, i
)) {
312 p
->first_page
= page
;
317 static int destroy_compound_page(struct page
*page
, unsigned long order
)
320 int nr_pages
= 1 << order
;
323 if (unlikely(compound_order(page
) != order
) ||
324 unlikely(!PageHead(page
))) {
329 __ClearPageHead(page
);
331 for (i
= 1; i
< nr_pages
; i
++) {
332 struct page
*p
= page
+ i
;
334 if (unlikely(!PageTail(p
) | (p
->first_page
!= page
))) {
344 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
349 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
350 * and __GFP_HIGHMEM from hard or soft interrupt context.
352 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
353 for (i
= 0; i
< (1 << order
); i
++)
354 clear_highpage(page
+ i
);
357 static inline void set_page_order(struct page
*page
, int order
)
359 set_page_private(page
, order
);
360 __SetPageBuddy(page
);
363 static inline void rmv_page_order(struct page
*page
)
365 __ClearPageBuddy(page
);
366 set_page_private(page
, 0);
370 * Locate the struct page for both the matching buddy in our
371 * pair (buddy1) and the combined O(n+1) page they form (page).
373 * 1) Any buddy B1 will have an order O twin B2 which satisfies
374 * the following equation:
376 * For example, if the starting buddy (buddy2) is #8 its order
378 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
380 * 2) Any buddy B will have an order O+1 parent P which
381 * satisfies the following equation:
384 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
386 static inline struct page
*
387 __page_find_buddy(struct page
*page
, unsigned long page_idx
, unsigned int order
)
389 unsigned long buddy_idx
= page_idx
^ (1 << order
);
391 return page
+ (buddy_idx
- page_idx
);
394 static inline unsigned long
395 __find_combined_index(unsigned long page_idx
, unsigned int order
)
397 return (page_idx
& ~(1 << order
));
401 * This function checks whether a page is free && is the buddy
402 * we can do coalesce a page and its buddy if
403 * (a) the buddy is not in a hole &&
404 * (b) the buddy is in the buddy system &&
405 * (c) a page and its buddy have the same order &&
406 * (d) a page and its buddy are in the same zone.
408 * For recording whether a page is in the buddy system, we use PG_buddy.
409 * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
411 * For recording page's order, we use page_private(page).
413 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
416 if (!pfn_valid_within(page_to_pfn(buddy
)))
419 if (page_zone_id(page
) != page_zone_id(buddy
))
422 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
423 BUG_ON(page_count(buddy
) != 0);
430 * Freeing function for a buddy system allocator.
432 * The concept of a buddy system is to maintain direct-mapped table
433 * (containing bit values) for memory blocks of various "orders".
434 * The bottom level table contains the map for the smallest allocatable
435 * units of memory (here, pages), and each level above it describes
436 * pairs of units from the levels below, hence, "buddies".
437 * At a high level, all that happens here is marking the table entry
438 * at the bottom level available, and propagating the changes upward
439 * as necessary, plus some accounting needed to play nicely with other
440 * parts of the VM system.
441 * At each level, we keep a list of pages, which are heads of continuous
442 * free pages of length of (1 << order) and marked with PG_buddy. Page's
443 * order is recorded in page_private(page) field.
444 * So when we are allocating or freeing one, we can derive the state of the
445 * other. That is, if we allocate a small block, and both were
446 * free, the remainder of the region must be split into blocks.
447 * If a block is freed, and its buddy is also free, then this
448 * triggers coalescing into a block of larger size.
453 static inline void __free_one_page(struct page
*page
,
454 struct zone
*zone
, unsigned int order
)
456 unsigned long page_idx
;
457 int order_size
= 1 << order
;
458 int migratetype
= get_pageblock_migratetype(page
);
460 if (unlikely(PageCompound(page
)))
461 if (unlikely(destroy_compound_page(page
, order
)))
464 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
466 VM_BUG_ON(page_idx
& (order_size
- 1));
467 VM_BUG_ON(bad_range(zone
, page
));
469 __mod_zone_page_state(zone
, NR_FREE_PAGES
, order_size
);
470 while (order
< MAX_ORDER
-1) {
471 unsigned long combined_idx
;
474 buddy
= __page_find_buddy(page
, page_idx
, order
);
475 if (!page_is_buddy(page
, buddy
, order
))
478 /* Our buddy is free, merge with it and move up one order. */
479 list_del(&buddy
->lru
);
480 zone
->free_area
[order
].nr_free
--;
481 rmv_page_order(buddy
);
482 combined_idx
= __find_combined_index(page_idx
, order
);
483 page
= page
+ (combined_idx
- page_idx
);
484 page_idx
= combined_idx
;
487 set_page_order(page
, order
);
489 &zone
->free_area
[order
].free_list
[migratetype
]);
490 zone
->free_area
[order
].nr_free
++;
493 static inline int free_pages_check(struct page
*page
)
495 free_page_mlock(page
);
496 if (unlikely(page_mapcount(page
) |
497 (page
->mapping
!= NULL
) |
498 (page_count(page
) != 0) |
499 (page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
))) {
503 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
504 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
509 * Frees a list of pages.
510 * Assumes all pages on list are in same zone, and of same order.
511 * count is the number of pages to free.
513 * If the zone was previously in an "all pages pinned" state then look to
514 * see if this freeing clears that state.
516 * And clear the zone's pages_scanned counter, to hold off the "all pages are
517 * pinned" detection logic.
519 static void free_pages_bulk(struct zone
*zone
, int count
,
520 struct list_head
*list
, int order
)
522 spin_lock(&zone
->lock
);
523 zone_clear_flag(zone
, ZONE_ALL_UNRECLAIMABLE
);
524 zone
->pages_scanned
= 0;
528 VM_BUG_ON(list_empty(list
));
529 page
= list_entry(list
->prev
, struct page
, lru
);
530 /* have to delete it as __free_one_page list manipulates */
531 list_del(&page
->lru
);
532 __free_one_page(page
, zone
, order
);
534 spin_unlock(&zone
->lock
);
537 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
)
539 spin_lock(&zone
->lock
);
540 zone_clear_flag(zone
, ZONE_ALL_UNRECLAIMABLE
);
541 zone
->pages_scanned
= 0;
542 __free_one_page(page
, zone
, order
);
543 spin_unlock(&zone
->lock
);
546 static void __free_pages_ok(struct page
*page
, unsigned int order
)
552 for (i
= 0 ; i
< (1 << order
) ; ++i
)
553 bad
+= free_pages_check(page
+ i
);
557 if (!PageHighMem(page
)) {
558 debug_check_no_locks_freed(page_address(page
),PAGE_SIZE
<<order
);
559 debug_check_no_obj_freed(page_address(page
),
562 arch_free_page(page
, order
);
563 kernel_map_pages(page
, 1 << order
, 0);
565 local_irq_save(flags
);
566 __count_vm_events(PGFREE
, 1 << order
);
567 free_one_page(page_zone(page
), page
, order
);
568 local_irq_restore(flags
);
572 * permit the bootmem allocator to evade page validation on high-order frees
574 void __meminit
__free_pages_bootmem(struct page
*page
, unsigned int order
)
577 __ClearPageReserved(page
);
578 set_page_count(page
, 0);
579 set_page_refcounted(page
);
585 for (loop
= 0; loop
< BITS_PER_LONG
; loop
++) {
586 struct page
*p
= &page
[loop
];
588 if (loop
+ 1 < BITS_PER_LONG
)
590 __ClearPageReserved(p
);
591 set_page_count(p
, 0);
594 set_page_refcounted(page
);
595 __free_pages(page
, order
);
601 * The order of subdivision here is critical for the IO subsystem.
602 * Please do not alter this order without good reasons and regression
603 * testing. Specifically, as large blocks of memory are subdivided,
604 * the order in which smaller blocks are delivered depends on the order
605 * they're subdivided in this function. This is the primary factor
606 * influencing the order in which pages are delivered to the IO
607 * subsystem according to empirical testing, and this is also justified
608 * by considering the behavior of a buddy system containing a single
609 * large block of memory acted on by a series of small allocations.
610 * This behavior is a critical factor in sglist merging's success.
614 static inline void expand(struct zone
*zone
, struct page
*page
,
615 int low
, int high
, struct free_area
*area
,
618 unsigned long size
= 1 << high
;
624 VM_BUG_ON(bad_range(zone
, &page
[size
]));
625 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
627 set_page_order(&page
[size
], high
);
632 * This page is about to be returned from the page allocator
634 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
636 if (unlikely(page_mapcount(page
) |
637 (page
->mapping
!= NULL
) |
638 (page_count(page
) != 0) |
639 (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
))) {
644 set_page_private(page
, 0);
645 set_page_refcounted(page
);
647 arch_alloc_page(page
, order
);
648 kernel_map_pages(page
, 1 << order
, 1);
650 if (gfp_flags
& __GFP_ZERO
)
651 prep_zero_page(page
, order
, gfp_flags
);
653 if (order
&& (gfp_flags
& __GFP_COMP
))
654 prep_compound_page(page
, order
);
660 * Go through the free lists for the given migratetype and remove
661 * the smallest available page from the freelists
663 static struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
666 unsigned int current_order
;
667 struct free_area
* area
;
670 /* Find a page of the appropriate size in the preferred list */
671 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
672 area
= &(zone
->free_area
[current_order
]);
673 if (list_empty(&area
->free_list
[migratetype
]))
676 page
= list_entry(area
->free_list
[migratetype
].next
,
678 list_del(&page
->lru
);
679 rmv_page_order(page
);
681 __mod_zone_page_state(zone
, NR_FREE_PAGES
, - (1UL << order
));
682 expand(zone
, page
, order
, current_order
, area
, migratetype
);
691 * This array describes the order lists are fallen back to when
692 * the free lists for the desirable migrate type are depleted
694 static int fallbacks
[MIGRATE_TYPES
][MIGRATE_TYPES
-1] = {
695 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
696 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
697 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
698 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
, MIGRATE_RESERVE
, MIGRATE_RESERVE
}, /* Never used */
702 * Move the free pages in a range to the free lists of the requested type.
703 * Note that start_page and end_pages are not aligned on a pageblock
704 * boundary. If alignment is required, use move_freepages_block()
706 static int move_freepages(struct zone
*zone
,
707 struct page
*start_page
, struct page
*end_page
,
714 #ifndef CONFIG_HOLES_IN_ZONE
716 * page_zone is not safe to call in this context when
717 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
718 * anyway as we check zone boundaries in move_freepages_block().
719 * Remove at a later date when no bug reports exist related to
720 * grouping pages by mobility
722 BUG_ON(page_zone(start_page
) != page_zone(end_page
));
725 for (page
= start_page
; page
<= end_page
;) {
726 /* Make sure we are not inadvertently changing nodes */
727 VM_BUG_ON(page_to_nid(page
) != zone_to_nid(zone
));
729 if (!pfn_valid_within(page_to_pfn(page
))) {
734 if (!PageBuddy(page
)) {
739 order
= page_order(page
);
740 list_del(&page
->lru
);
742 &zone
->free_area
[order
].free_list
[migratetype
]);
744 pages_moved
+= 1 << order
;
750 static int move_freepages_block(struct zone
*zone
, struct page
*page
,
753 unsigned long start_pfn
, end_pfn
;
754 struct page
*start_page
, *end_page
;
756 start_pfn
= page_to_pfn(page
);
757 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
758 start_page
= pfn_to_page(start_pfn
);
759 end_page
= start_page
+ pageblock_nr_pages
- 1;
760 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
762 /* Do not cross zone boundaries */
763 if (start_pfn
< zone
->zone_start_pfn
)
765 if (end_pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
768 return move_freepages(zone
, start_page
, end_page
, migratetype
);
771 /* Remove an element from the buddy allocator from the fallback list */
772 static struct page
*__rmqueue_fallback(struct zone
*zone
, int order
,
773 int start_migratetype
)
775 struct free_area
* area
;
780 /* Find the largest possible block of pages in the other list */
781 for (current_order
= MAX_ORDER
-1; current_order
>= order
;
783 for (i
= 0; i
< MIGRATE_TYPES
- 1; i
++) {
784 migratetype
= fallbacks
[start_migratetype
][i
];
786 /* MIGRATE_RESERVE handled later if necessary */
787 if (migratetype
== MIGRATE_RESERVE
)
790 area
= &(zone
->free_area
[current_order
]);
791 if (list_empty(&area
->free_list
[migratetype
]))
794 page
= list_entry(area
->free_list
[migratetype
].next
,
799 * If breaking a large block of pages, move all free
800 * pages to the preferred allocation list. If falling
801 * back for a reclaimable kernel allocation, be more
802 * agressive about taking ownership of free pages
804 if (unlikely(current_order
>= (pageblock_order
>> 1)) ||
805 start_migratetype
== MIGRATE_RECLAIMABLE
) {
807 pages
= move_freepages_block(zone
, page
,
810 /* Claim the whole block if over half of it is free */
811 if (pages
>= (1 << (pageblock_order
-1)))
812 set_pageblock_migratetype(page
,
815 migratetype
= start_migratetype
;
818 /* Remove the page from the freelists */
819 list_del(&page
->lru
);
820 rmv_page_order(page
);
821 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
824 if (current_order
== pageblock_order
)
825 set_pageblock_migratetype(page
,
828 expand(zone
, page
, order
, current_order
, area
, migratetype
);
833 /* Use MIGRATE_RESERVE rather than fail an allocation */
834 return __rmqueue_smallest(zone
, order
, MIGRATE_RESERVE
);
838 * Do the hard work of removing an element from the buddy allocator.
839 * Call me with the zone->lock already held.
841 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
846 page
= __rmqueue_smallest(zone
, order
, migratetype
);
849 page
= __rmqueue_fallback(zone
, order
, migratetype
);
855 * Obtain a specified number of elements from the buddy allocator, all under
856 * a single hold of the lock, for efficiency. Add them to the supplied list.
857 * Returns the number of new pages which were placed at *list.
859 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
860 unsigned long count
, struct list_head
*list
,
865 spin_lock(&zone
->lock
);
866 for (i
= 0; i
< count
; ++i
) {
867 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
868 if (unlikely(page
== NULL
))
872 * Split buddy pages returned by expand() are received here
873 * in physical page order. The page is added to the callers and
874 * list and the list head then moves forward. From the callers
875 * perspective, the linked list is ordered by page number in
876 * some conditions. This is useful for IO devices that can
877 * merge IO requests if the physical pages are ordered
880 list_add(&page
->lru
, list
);
881 set_page_private(page
, migratetype
);
884 spin_unlock(&zone
->lock
);
890 * Called from the vmstat counter updater to drain pagesets of this
891 * currently executing processor on remote nodes after they have
894 * Note that this function must be called with the thread pinned to
895 * a single processor.
897 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
902 local_irq_save(flags
);
903 if (pcp
->count
>= pcp
->batch
)
904 to_drain
= pcp
->batch
;
906 to_drain
= pcp
->count
;
907 free_pages_bulk(zone
, to_drain
, &pcp
->list
, 0);
908 pcp
->count
-= to_drain
;
909 local_irq_restore(flags
);
914 * Drain pages of the indicated processor.
916 * The processor must either be the current processor and the
917 * thread pinned to the current processor or a processor that
920 static void drain_pages(unsigned int cpu
)
925 for_each_zone(zone
) {
926 struct per_cpu_pageset
*pset
;
927 struct per_cpu_pages
*pcp
;
929 if (!populated_zone(zone
))
932 pset
= zone_pcp(zone
, cpu
);
935 local_irq_save(flags
);
936 free_pages_bulk(zone
, pcp
->count
, &pcp
->list
, 0);
938 local_irq_restore(flags
);
943 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
945 void drain_local_pages(void *arg
)
947 drain_pages(smp_processor_id());
951 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
953 void drain_all_pages(void)
955 on_each_cpu(drain_local_pages
, NULL
, 1);
958 #ifdef CONFIG_HIBERNATION
960 void mark_free_pages(struct zone
*zone
)
962 unsigned long pfn
, max_zone_pfn
;
965 struct list_head
*curr
;
967 if (!zone
->spanned_pages
)
970 spin_lock_irqsave(&zone
->lock
, flags
);
972 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
973 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
974 if (pfn_valid(pfn
)) {
975 struct page
*page
= pfn_to_page(pfn
);
977 if (!swsusp_page_is_forbidden(page
))
978 swsusp_unset_page_free(page
);
981 for_each_migratetype_order(order
, t
) {
982 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
985 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
986 for (i
= 0; i
< (1UL << order
); i
++)
987 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
990 spin_unlock_irqrestore(&zone
->lock
, flags
);
992 #endif /* CONFIG_PM */
995 * Free a 0-order page
997 static void free_hot_cold_page(struct page
*page
, int cold
)
999 struct zone
*zone
= page_zone(page
);
1000 struct per_cpu_pages
*pcp
;
1001 unsigned long flags
;
1004 page
->mapping
= NULL
;
1005 if (free_pages_check(page
))
1008 if (!PageHighMem(page
)) {
1009 debug_check_no_locks_freed(page_address(page
), PAGE_SIZE
);
1010 debug_check_no_obj_freed(page_address(page
), PAGE_SIZE
);
1012 arch_free_page(page
, 0);
1013 kernel_map_pages(page
, 1, 0);
1015 pcp
= &zone_pcp(zone
, get_cpu())->pcp
;
1016 local_irq_save(flags
);
1017 __count_vm_event(PGFREE
);
1019 list_add_tail(&page
->lru
, &pcp
->list
);
1021 list_add(&page
->lru
, &pcp
->list
);
1022 set_page_private(page
, get_pageblock_migratetype(page
));
1024 if (pcp
->count
>= pcp
->high
) {
1025 free_pages_bulk(zone
, pcp
->batch
, &pcp
->list
, 0);
1026 pcp
->count
-= pcp
->batch
;
1028 local_irq_restore(flags
);
1032 void free_hot_page(struct page
*page
)
1034 free_hot_cold_page(page
, 0);
1037 void free_cold_page(struct page
*page
)
1039 free_hot_cold_page(page
, 1);
1043 * split_page takes a non-compound higher-order page, and splits it into
1044 * n (1<<order) sub-pages: page[0..n]
1045 * Each sub-page must be freed individually.
1047 * Note: this is probably too low level an operation for use in drivers.
1048 * Please consult with lkml before using this in your driver.
1050 void split_page(struct page
*page
, unsigned int order
)
1054 VM_BUG_ON(PageCompound(page
));
1055 VM_BUG_ON(!page_count(page
));
1056 for (i
= 1; i
< (1 << order
); i
++)
1057 set_page_refcounted(page
+ i
);
1061 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1062 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1065 static struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
1066 struct zone
*zone
, int order
, gfp_t gfp_flags
)
1068 unsigned long flags
;
1070 int cold
= !!(gfp_flags
& __GFP_COLD
);
1072 int migratetype
= allocflags_to_migratetype(gfp_flags
);
1076 if (likely(order
== 0)) {
1077 struct per_cpu_pages
*pcp
;
1079 pcp
= &zone_pcp(zone
, cpu
)->pcp
;
1080 local_irq_save(flags
);
1082 pcp
->count
= rmqueue_bulk(zone
, 0,
1083 pcp
->batch
, &pcp
->list
, migratetype
);
1084 if (unlikely(!pcp
->count
))
1088 /* Find a page of the appropriate migrate type */
1090 list_for_each_entry_reverse(page
, &pcp
->list
, lru
)
1091 if (page_private(page
) == migratetype
)
1094 list_for_each_entry(page
, &pcp
->list
, lru
)
1095 if (page_private(page
) == migratetype
)
1099 /* Allocate more to the pcp list if necessary */
1100 if (unlikely(&page
->lru
== &pcp
->list
)) {
1101 pcp
->count
+= rmqueue_bulk(zone
, 0,
1102 pcp
->batch
, &pcp
->list
, migratetype
);
1103 page
= list_entry(pcp
->list
.next
, struct page
, lru
);
1106 list_del(&page
->lru
);
1109 spin_lock_irqsave(&zone
->lock
, flags
);
1110 page
= __rmqueue(zone
, order
, migratetype
);
1111 spin_unlock(&zone
->lock
);
1116 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
1117 zone_statistics(preferred_zone
, zone
);
1118 local_irq_restore(flags
);
1121 VM_BUG_ON(bad_range(zone
, page
));
1122 if (prep_new_page(page
, order
, gfp_flags
))
1127 local_irq_restore(flags
);
1132 #define ALLOC_NO_WATERMARKS 0x01 /* don't check watermarks at all */
1133 #define ALLOC_WMARK_MIN 0x02 /* use pages_min watermark */
1134 #define ALLOC_WMARK_LOW 0x04 /* use pages_low watermark */
1135 #define ALLOC_WMARK_HIGH 0x08 /* use pages_high watermark */
1136 #define ALLOC_HARDER 0x10 /* try to alloc harder */
1137 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
1138 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
1140 #ifdef CONFIG_FAIL_PAGE_ALLOC
1142 static struct fail_page_alloc_attr
{
1143 struct fault_attr attr
;
1145 u32 ignore_gfp_highmem
;
1146 u32 ignore_gfp_wait
;
1149 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1151 struct dentry
*ignore_gfp_highmem_file
;
1152 struct dentry
*ignore_gfp_wait_file
;
1153 struct dentry
*min_order_file
;
1155 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1157 } fail_page_alloc
= {
1158 .attr
= FAULT_ATTR_INITIALIZER
,
1159 .ignore_gfp_wait
= 1,
1160 .ignore_gfp_highmem
= 1,
1164 static int __init
setup_fail_page_alloc(char *str
)
1166 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
1168 __setup("fail_page_alloc=", setup_fail_page_alloc
);
1170 static int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1172 if (order
< fail_page_alloc
.min_order
)
1174 if (gfp_mask
& __GFP_NOFAIL
)
1176 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
1178 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
1181 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
1184 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1186 static int __init
fail_page_alloc_debugfs(void)
1188 mode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
1192 err
= init_fault_attr_dentries(&fail_page_alloc
.attr
,
1196 dir
= fail_page_alloc
.attr
.dentries
.dir
;
1198 fail_page_alloc
.ignore_gfp_wait_file
=
1199 debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
1200 &fail_page_alloc
.ignore_gfp_wait
);
1202 fail_page_alloc
.ignore_gfp_highmem_file
=
1203 debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
1204 &fail_page_alloc
.ignore_gfp_highmem
);
1205 fail_page_alloc
.min_order_file
=
1206 debugfs_create_u32("min-order", mode
, dir
,
1207 &fail_page_alloc
.min_order
);
1209 if (!fail_page_alloc
.ignore_gfp_wait_file
||
1210 !fail_page_alloc
.ignore_gfp_highmem_file
||
1211 !fail_page_alloc
.min_order_file
) {
1213 debugfs_remove(fail_page_alloc
.ignore_gfp_wait_file
);
1214 debugfs_remove(fail_page_alloc
.ignore_gfp_highmem_file
);
1215 debugfs_remove(fail_page_alloc
.min_order_file
);
1216 cleanup_fault_attr_dentries(&fail_page_alloc
.attr
);
1222 late_initcall(fail_page_alloc_debugfs
);
1224 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1226 #else /* CONFIG_FAIL_PAGE_ALLOC */
1228 static inline int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1233 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1236 * Return 1 if free pages are above 'mark'. This takes into account the order
1237 * of the allocation.
1239 int zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1240 int classzone_idx
, int alloc_flags
)
1242 /* free_pages my go negative - that's OK */
1244 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
) - (1 << order
) + 1;
1247 if (alloc_flags
& ALLOC_HIGH
)
1249 if (alloc_flags
& ALLOC_HARDER
)
1252 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
1254 for (o
= 0; o
< order
; o
++) {
1255 /* At the next order, this order's pages become unavailable */
1256 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1258 /* Require fewer higher order pages to be free */
1261 if (free_pages
<= min
)
1269 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1270 * skip over zones that are not allowed by the cpuset, or that have
1271 * been recently (in last second) found to be nearly full. See further
1272 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1273 * that have to skip over a lot of full or unallowed zones.
1275 * If the zonelist cache is present in the passed in zonelist, then
1276 * returns a pointer to the allowed node mask (either the current
1277 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1279 * If the zonelist cache is not available for this zonelist, does
1280 * nothing and returns NULL.
1282 * If the fullzones BITMAP in the zonelist cache is stale (more than
1283 * a second since last zap'd) then we zap it out (clear its bits.)
1285 * We hold off even calling zlc_setup, until after we've checked the
1286 * first zone in the zonelist, on the theory that most allocations will
1287 * be satisfied from that first zone, so best to examine that zone as
1288 * quickly as we can.
1290 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1292 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1293 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1295 zlc
= zonelist
->zlcache_ptr
;
1299 if (time_after(jiffies
, zlc
->last_full_zap
+ HZ
)) {
1300 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1301 zlc
->last_full_zap
= jiffies
;
1304 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1305 &cpuset_current_mems_allowed
:
1306 &node_states
[N_HIGH_MEMORY
];
1307 return allowednodes
;
1311 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1312 * if it is worth looking at further for free memory:
1313 * 1) Check that the zone isn't thought to be full (doesn't have its
1314 * bit set in the zonelist_cache fullzones BITMAP).
1315 * 2) Check that the zones node (obtained from the zonelist_cache
1316 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1317 * Return true (non-zero) if zone is worth looking at further, or
1318 * else return false (zero) if it is not.
1320 * This check -ignores- the distinction between various watermarks,
1321 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1322 * found to be full for any variation of these watermarks, it will
1323 * be considered full for up to one second by all requests, unless
1324 * we are so low on memory on all allowed nodes that we are forced
1325 * into the second scan of the zonelist.
1327 * In the second scan we ignore this zonelist cache and exactly
1328 * apply the watermarks to all zones, even it is slower to do so.
1329 * We are low on memory in the second scan, and should leave no stone
1330 * unturned looking for a free page.
1332 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1333 nodemask_t
*allowednodes
)
1335 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1336 int i
; /* index of *z in zonelist zones */
1337 int n
; /* node that zone *z is on */
1339 zlc
= zonelist
->zlcache_ptr
;
1343 i
= z
- zonelist
->_zonerefs
;
1346 /* This zone is worth trying if it is allowed but not full */
1347 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1351 * Given 'z' scanning a zonelist, set the corresponding bit in
1352 * zlc->fullzones, so that subsequent attempts to allocate a page
1353 * from that zone don't waste time re-examining it.
1355 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1357 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1358 int i
; /* index of *z in zonelist zones */
1360 zlc
= zonelist
->zlcache_ptr
;
1364 i
= z
- zonelist
->_zonerefs
;
1366 set_bit(i
, zlc
->fullzones
);
1369 #else /* CONFIG_NUMA */
1371 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1376 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1377 nodemask_t
*allowednodes
)
1382 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1385 #endif /* CONFIG_NUMA */
1388 * get_page_from_freelist goes through the zonelist trying to allocate
1391 static struct page
*
1392 get_page_from_freelist(gfp_t gfp_mask
, nodemask_t
*nodemask
, unsigned int order
,
1393 struct zonelist
*zonelist
, int high_zoneidx
, int alloc_flags
)
1396 struct page
*page
= NULL
;
1398 struct zone
*zone
, *preferred_zone
;
1399 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1400 int zlc_active
= 0; /* set if using zonelist_cache */
1401 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1403 (void)first_zones_zonelist(zonelist
, high_zoneidx
, nodemask
,
1405 if (!preferred_zone
)
1408 classzone_idx
= zone_idx(preferred_zone
);
1412 * Scan zonelist, looking for a zone with enough free.
1413 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1415 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
1416 high_zoneidx
, nodemask
) {
1417 if (NUMA_BUILD
&& zlc_active
&&
1418 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1420 if ((alloc_flags
& ALLOC_CPUSET
) &&
1421 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1424 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
1426 if (alloc_flags
& ALLOC_WMARK_MIN
)
1427 mark
= zone
->pages_min
;
1428 else if (alloc_flags
& ALLOC_WMARK_LOW
)
1429 mark
= zone
->pages_low
;
1431 mark
= zone
->pages_high
;
1432 if (!zone_watermark_ok(zone
, order
, mark
,
1433 classzone_idx
, alloc_flags
)) {
1434 if (!zone_reclaim_mode
||
1435 !zone_reclaim(zone
, gfp_mask
, order
))
1436 goto this_zone_full
;
1440 page
= buffered_rmqueue(preferred_zone
, zone
, order
, gfp_mask
);
1445 zlc_mark_zone_full(zonelist
, z
);
1447 if (NUMA_BUILD
&& !did_zlc_setup
) {
1448 /* we do zlc_setup after the first zone is tried */
1449 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1455 if (unlikely(NUMA_BUILD
&& page
== NULL
&& zlc_active
)) {
1456 /* Disable zlc cache for second zonelist scan */
1464 * This is the 'heart' of the zoned buddy allocator.
1467 __alloc_pages_internal(gfp_t gfp_mask
, unsigned int order
,
1468 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
1470 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
1471 enum zone_type high_zoneidx
= gfp_zone(gfp_mask
);
1475 struct reclaim_state reclaim_state
;
1476 struct task_struct
*p
= current
;
1479 unsigned long did_some_progress
;
1480 unsigned long pages_reclaimed
= 0;
1482 might_sleep_if(wait
);
1484 if (should_fail_alloc_page(gfp_mask
, order
))
1488 z
= zonelist
->_zonerefs
; /* the list of zones suitable for gfp_mask */
1490 if (unlikely(!z
->zone
)) {
1492 * Happens if we have an empty zonelist as a result of
1493 * GFP_THISNODE being used on a memoryless node
1498 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
, order
,
1499 zonelist
, high_zoneidx
, ALLOC_WMARK_LOW
|ALLOC_CPUSET
);
1504 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
1505 * __GFP_NOWARN set) should not cause reclaim since the subsystem
1506 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
1507 * using a larger set of nodes after it has established that the
1508 * allowed per node queues are empty and that nodes are
1511 if (NUMA_BUILD
&& (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
1514 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
)
1515 wakeup_kswapd(zone
, order
);
1518 * OK, we're below the kswapd watermark and have kicked background
1519 * reclaim. Now things get more complex, so set up alloc_flags according
1520 * to how we want to proceed.
1522 * The caller may dip into page reserves a bit more if the caller
1523 * cannot run direct reclaim, or if the caller has realtime scheduling
1524 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
1525 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1527 alloc_flags
= ALLOC_WMARK_MIN
;
1528 if ((unlikely(rt_task(p
)) && !in_interrupt()) || !wait
)
1529 alloc_flags
|= ALLOC_HARDER
;
1530 if (gfp_mask
& __GFP_HIGH
)
1531 alloc_flags
|= ALLOC_HIGH
;
1533 alloc_flags
|= ALLOC_CPUSET
;
1536 * Go through the zonelist again. Let __GFP_HIGH and allocations
1537 * coming from realtime tasks go deeper into reserves.
1539 * This is the last chance, in general, before the goto nopage.
1540 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1541 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1543 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
, zonelist
,
1544 high_zoneidx
, alloc_flags
);
1548 /* This allocation should allow future memory freeing. */
1551 if (((p
->flags
& PF_MEMALLOC
) || unlikely(test_thread_flag(TIF_MEMDIE
)))
1552 && !in_interrupt()) {
1553 if (!(gfp_mask
& __GFP_NOMEMALLOC
)) {
1555 /* go through the zonelist yet again, ignoring mins */
1556 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
1557 zonelist
, high_zoneidx
, ALLOC_NO_WATERMARKS
);
1560 if (gfp_mask
& __GFP_NOFAIL
) {
1561 congestion_wait(WRITE
, HZ
/50);
1568 /* Atomic allocations - we can't balance anything */
1574 /* We now go into synchronous reclaim */
1575 cpuset_memory_pressure_bump();
1577 * The task's cpuset might have expanded its set of allowable nodes
1579 cpuset_update_task_memory_state();
1580 p
->flags
|= PF_MEMALLOC
;
1581 reclaim_state
.reclaimed_slab
= 0;
1582 p
->reclaim_state
= &reclaim_state
;
1584 did_some_progress
= try_to_free_pages(zonelist
, order
, gfp_mask
);
1586 p
->reclaim_state
= NULL
;
1587 p
->flags
&= ~PF_MEMALLOC
;
1594 if (likely(did_some_progress
)) {
1595 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
1596 zonelist
, high_zoneidx
, alloc_flags
);
1599 } else if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
1600 if (!try_set_zone_oom(zonelist
, gfp_mask
)) {
1601 schedule_timeout_uninterruptible(1);
1606 * Go through the zonelist yet one more time, keep
1607 * very high watermark here, this is only to catch
1608 * a parallel oom killing, we must fail if we're still
1609 * under heavy pressure.
1611 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
,
1612 order
, zonelist
, high_zoneidx
,
1613 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
);
1615 clear_zonelist_oom(zonelist
, gfp_mask
);
1619 /* The OOM killer will not help higher order allocs so fail */
1620 if (order
> PAGE_ALLOC_COSTLY_ORDER
) {
1621 clear_zonelist_oom(zonelist
, gfp_mask
);
1625 out_of_memory(zonelist
, gfp_mask
, order
);
1626 clear_zonelist_oom(zonelist
, gfp_mask
);
1631 * Don't let big-order allocations loop unless the caller explicitly
1632 * requests that. Wait for some write requests to complete then retry.
1634 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
1635 * means __GFP_NOFAIL, but that may not be true in other
1638 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
1639 * specified, then we retry until we no longer reclaim any pages
1640 * (above), or we've reclaimed an order of pages at least as
1641 * large as the allocation's order. In both cases, if the
1642 * allocation still fails, we stop retrying.
1644 pages_reclaimed
+= did_some_progress
;
1646 if (!(gfp_mask
& __GFP_NORETRY
)) {
1647 if (order
<= PAGE_ALLOC_COSTLY_ORDER
) {
1650 if (gfp_mask
& __GFP_REPEAT
&&
1651 pages_reclaimed
< (1 << order
))
1654 if (gfp_mask
& __GFP_NOFAIL
)
1658 congestion_wait(WRITE
, HZ
/50);
1663 if (!(gfp_mask
& __GFP_NOWARN
) && printk_ratelimit()) {
1664 printk(KERN_WARNING
"%s: page allocation failure."
1665 " order:%d, mode:0x%x\n",
1666 p
->comm
, order
, gfp_mask
);
1673 EXPORT_SYMBOL(__alloc_pages_internal
);
1676 * Common helper functions.
1678 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
1681 page
= alloc_pages(gfp_mask
, order
);
1684 return (unsigned long) page_address(page
);
1687 EXPORT_SYMBOL(__get_free_pages
);
1689 unsigned long get_zeroed_page(gfp_t gfp_mask
)
1694 * get_zeroed_page() returns a 32-bit address, which cannot represent
1697 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
1699 page
= alloc_pages(gfp_mask
| __GFP_ZERO
, 0);
1701 return (unsigned long) page_address(page
);
1705 EXPORT_SYMBOL(get_zeroed_page
);
1707 void __pagevec_free(struct pagevec
*pvec
)
1709 int i
= pagevec_count(pvec
);
1712 free_hot_cold_page(pvec
->pages
[i
], pvec
->cold
);
1715 void __free_pages(struct page
*page
, unsigned int order
)
1717 if (put_page_testzero(page
)) {
1719 free_hot_page(page
);
1721 __free_pages_ok(page
, order
);
1725 EXPORT_SYMBOL(__free_pages
);
1727 void free_pages(unsigned long addr
, unsigned int order
)
1730 VM_BUG_ON(!virt_addr_valid((void *)addr
));
1731 __free_pages(virt_to_page((void *)addr
), order
);
1735 EXPORT_SYMBOL(free_pages
);
1738 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
1739 * @size: the number of bytes to allocate
1740 * @gfp_mask: GFP flags for the allocation
1742 * This function is similar to alloc_pages(), except that it allocates the
1743 * minimum number of pages to satisfy the request. alloc_pages() can only
1744 * allocate memory in power-of-two pages.
1746 * This function is also limited by MAX_ORDER.
1748 * Memory allocated by this function must be released by free_pages_exact().
1750 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
1752 unsigned int order
= get_order(size
);
1755 addr
= __get_free_pages(gfp_mask
, order
);
1757 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
1758 unsigned long used
= addr
+ PAGE_ALIGN(size
);
1760 split_page(virt_to_page(addr
), order
);
1761 while (used
< alloc_end
) {
1767 return (void *)addr
;
1769 EXPORT_SYMBOL(alloc_pages_exact
);
1772 * free_pages_exact - release memory allocated via alloc_pages_exact()
1773 * @virt: the value returned by alloc_pages_exact.
1774 * @size: size of allocation, same value as passed to alloc_pages_exact().
1776 * Release the memory allocated by a previous call to alloc_pages_exact.
1778 void free_pages_exact(void *virt
, size_t size
)
1780 unsigned long addr
= (unsigned long)virt
;
1781 unsigned long end
= addr
+ PAGE_ALIGN(size
);
1783 while (addr
< end
) {
1788 EXPORT_SYMBOL(free_pages_exact
);
1790 static unsigned int nr_free_zone_pages(int offset
)
1795 /* Just pick one node, since fallback list is circular */
1796 unsigned int sum
= 0;
1798 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
1800 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
1801 unsigned long size
= zone
->present_pages
;
1802 unsigned long high
= zone
->pages_high
;
1811 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
1813 unsigned int nr_free_buffer_pages(void)
1815 return nr_free_zone_pages(gfp_zone(GFP_USER
));
1817 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
1820 * Amount of free RAM allocatable within all zones
1822 unsigned int nr_free_pagecache_pages(void)
1824 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
1827 static inline void show_node(struct zone
*zone
)
1830 printk("Node %d ", zone_to_nid(zone
));
1833 void si_meminfo(struct sysinfo
*val
)
1835 val
->totalram
= totalram_pages
;
1837 val
->freeram
= global_page_state(NR_FREE_PAGES
);
1838 val
->bufferram
= nr_blockdev_pages();
1839 val
->totalhigh
= totalhigh_pages
;
1840 val
->freehigh
= nr_free_highpages();
1841 val
->mem_unit
= PAGE_SIZE
;
1844 EXPORT_SYMBOL(si_meminfo
);
1847 void si_meminfo_node(struct sysinfo
*val
, int nid
)
1849 pg_data_t
*pgdat
= NODE_DATA(nid
);
1851 val
->totalram
= pgdat
->node_present_pages
;
1852 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
1853 #ifdef CONFIG_HIGHMEM
1854 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
1855 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
1861 val
->mem_unit
= PAGE_SIZE
;
1865 #define K(x) ((x) << (PAGE_SHIFT-10))
1868 * Show free area list (used inside shift_scroll-lock stuff)
1869 * We also calculate the percentage fragmentation. We do this by counting the
1870 * memory on each free list with the exception of the first item on the list.
1872 void show_free_areas(void)
1877 for_each_zone(zone
) {
1878 if (!populated_zone(zone
))
1882 printk("%s per-cpu:\n", zone
->name
);
1884 for_each_online_cpu(cpu
) {
1885 struct per_cpu_pageset
*pageset
;
1887 pageset
= zone_pcp(zone
, cpu
);
1889 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
1890 cpu
, pageset
->pcp
.high
,
1891 pageset
->pcp
.batch
, pageset
->pcp
.count
);
1895 printk("Active_anon:%lu active_file:%lu inactive_anon:%lu\n"
1896 " inactive_file:%lu"
1897 //TODO: check/adjust line lengths
1898 #ifdef CONFIG_UNEVICTABLE_LRU
1901 " dirty:%lu writeback:%lu unstable:%lu\n"
1902 " free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n",
1903 global_page_state(NR_ACTIVE_ANON
),
1904 global_page_state(NR_ACTIVE_FILE
),
1905 global_page_state(NR_INACTIVE_ANON
),
1906 global_page_state(NR_INACTIVE_FILE
),
1907 #ifdef CONFIG_UNEVICTABLE_LRU
1908 global_page_state(NR_UNEVICTABLE
),
1910 global_page_state(NR_FILE_DIRTY
),
1911 global_page_state(NR_WRITEBACK
),
1912 global_page_state(NR_UNSTABLE_NFS
),
1913 global_page_state(NR_FREE_PAGES
),
1914 global_page_state(NR_SLAB_RECLAIMABLE
) +
1915 global_page_state(NR_SLAB_UNRECLAIMABLE
),
1916 global_page_state(NR_FILE_MAPPED
),
1917 global_page_state(NR_PAGETABLE
),
1918 global_page_state(NR_BOUNCE
));
1920 for_each_zone(zone
) {
1923 if (!populated_zone(zone
))
1932 " active_anon:%lukB"
1933 " inactive_anon:%lukB"
1934 " active_file:%lukB"
1935 " inactive_file:%lukB"
1936 #ifdef CONFIG_UNEVICTABLE_LRU
1937 " unevictable:%lukB"
1940 " pages_scanned:%lu"
1941 " all_unreclaimable? %s"
1944 K(zone_page_state(zone
, NR_FREE_PAGES
)),
1947 K(zone
->pages_high
),
1948 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
1949 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
1950 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
1951 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
1952 #ifdef CONFIG_UNEVICTABLE_LRU
1953 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
1955 K(zone
->present_pages
),
1956 zone
->pages_scanned
,
1957 (zone_is_all_unreclaimable(zone
) ? "yes" : "no")
1959 printk("lowmem_reserve[]:");
1960 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
1961 printk(" %lu", zone
->lowmem_reserve
[i
]);
1965 for_each_zone(zone
) {
1966 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
1968 if (!populated_zone(zone
))
1972 printk("%s: ", zone
->name
);
1974 spin_lock_irqsave(&zone
->lock
, flags
);
1975 for (order
= 0; order
< MAX_ORDER
; order
++) {
1976 nr
[order
] = zone
->free_area
[order
].nr_free
;
1977 total
+= nr
[order
] << order
;
1979 spin_unlock_irqrestore(&zone
->lock
, flags
);
1980 for (order
= 0; order
< MAX_ORDER
; order
++)
1981 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
1982 printk("= %lukB\n", K(total
));
1985 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
1987 show_swap_cache_info();
1990 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
1992 zoneref
->zone
= zone
;
1993 zoneref
->zone_idx
= zone_idx(zone
);
1997 * Builds allocation fallback zone lists.
1999 * Add all populated zones of a node to the zonelist.
2001 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
2002 int nr_zones
, enum zone_type zone_type
)
2006 BUG_ON(zone_type
>= MAX_NR_ZONES
);
2011 zone
= pgdat
->node_zones
+ zone_type
;
2012 if (populated_zone(zone
)) {
2013 zoneref_set_zone(zone
,
2014 &zonelist
->_zonerefs
[nr_zones
++]);
2015 check_highest_zone(zone_type
);
2018 } while (zone_type
);
2025 * 0 = automatic detection of better ordering.
2026 * 1 = order by ([node] distance, -zonetype)
2027 * 2 = order by (-zonetype, [node] distance)
2029 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
2030 * the same zonelist. So only NUMA can configure this param.
2032 #define ZONELIST_ORDER_DEFAULT 0
2033 #define ZONELIST_ORDER_NODE 1
2034 #define ZONELIST_ORDER_ZONE 2
2036 /* zonelist order in the kernel.
2037 * set_zonelist_order() will set this to NODE or ZONE.
2039 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2040 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
2044 /* The value user specified ....changed by config */
2045 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2046 /* string for sysctl */
2047 #define NUMA_ZONELIST_ORDER_LEN 16
2048 char numa_zonelist_order
[16] = "default";
2051 * interface for configure zonelist ordering.
2052 * command line option "numa_zonelist_order"
2053 * = "[dD]efault - default, automatic configuration.
2054 * = "[nN]ode - order by node locality, then by zone within node
2055 * = "[zZ]one - order by zone, then by locality within zone
2058 static int __parse_numa_zonelist_order(char *s
)
2060 if (*s
== 'd' || *s
== 'D') {
2061 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2062 } else if (*s
== 'n' || *s
== 'N') {
2063 user_zonelist_order
= ZONELIST_ORDER_NODE
;
2064 } else if (*s
== 'z' || *s
== 'Z') {
2065 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
2068 "Ignoring invalid numa_zonelist_order value: "
2075 static __init
int setup_numa_zonelist_order(char *s
)
2078 return __parse_numa_zonelist_order(s
);
2081 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
2084 * sysctl handler for numa_zonelist_order
2086 int numa_zonelist_order_handler(ctl_table
*table
, int write
,
2087 struct file
*file
, void __user
*buffer
, size_t *length
,
2090 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
2094 strncpy(saved_string
, (char*)table
->data
,
2095 NUMA_ZONELIST_ORDER_LEN
);
2096 ret
= proc_dostring(table
, write
, file
, buffer
, length
, ppos
);
2100 int oldval
= user_zonelist_order
;
2101 if (__parse_numa_zonelist_order((char*)table
->data
)) {
2103 * bogus value. restore saved string
2105 strncpy((char*)table
->data
, saved_string
,
2106 NUMA_ZONELIST_ORDER_LEN
);
2107 user_zonelist_order
= oldval
;
2108 } else if (oldval
!= user_zonelist_order
)
2109 build_all_zonelists();
2115 #define MAX_NODE_LOAD (num_online_nodes())
2116 static int node_load
[MAX_NUMNODES
];
2119 * find_next_best_node - find the next node that should appear in a given node's fallback list
2120 * @node: node whose fallback list we're appending
2121 * @used_node_mask: nodemask_t of already used nodes
2123 * We use a number of factors to determine which is the next node that should
2124 * appear on a given node's fallback list. The node should not have appeared
2125 * already in @node's fallback list, and it should be the next closest node
2126 * according to the distance array (which contains arbitrary distance values
2127 * from each node to each node in the system), and should also prefer nodes
2128 * with no CPUs, since presumably they'll have very little allocation pressure
2129 * on them otherwise.
2130 * It returns -1 if no node is found.
2132 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
2135 int min_val
= INT_MAX
;
2137 node_to_cpumask_ptr(tmp
, 0);
2139 /* Use the local node if we haven't already */
2140 if (!node_isset(node
, *used_node_mask
)) {
2141 node_set(node
, *used_node_mask
);
2145 for_each_node_state(n
, N_HIGH_MEMORY
) {
2147 /* Don't want a node to appear more than once */
2148 if (node_isset(n
, *used_node_mask
))
2151 /* Use the distance array to find the distance */
2152 val
= node_distance(node
, n
);
2154 /* Penalize nodes under us ("prefer the next node") */
2157 /* Give preference to headless and unused nodes */
2158 node_to_cpumask_ptr_next(tmp
, n
);
2159 if (!cpus_empty(*tmp
))
2160 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
2162 /* Slight preference for less loaded node */
2163 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
2164 val
+= node_load
[n
];
2166 if (val
< min_val
) {
2173 node_set(best_node
, *used_node_mask
);
2180 * Build zonelists ordered by node and zones within node.
2181 * This results in maximum locality--normal zone overflows into local
2182 * DMA zone, if any--but risks exhausting DMA zone.
2184 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
2187 struct zonelist
*zonelist
;
2189 zonelist
= &pgdat
->node_zonelists
[0];
2190 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
2192 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2194 zonelist
->_zonerefs
[j
].zone
= NULL
;
2195 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2199 * Build gfp_thisnode zonelists
2201 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
2204 struct zonelist
*zonelist
;
2206 zonelist
= &pgdat
->node_zonelists
[1];
2207 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
2208 zonelist
->_zonerefs
[j
].zone
= NULL
;
2209 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2213 * Build zonelists ordered by zone and nodes within zones.
2214 * This results in conserving DMA zone[s] until all Normal memory is
2215 * exhausted, but results in overflowing to remote node while memory
2216 * may still exist in local DMA zone.
2218 static int node_order
[MAX_NUMNODES
];
2220 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
2223 int zone_type
; /* needs to be signed */
2225 struct zonelist
*zonelist
;
2227 zonelist
= &pgdat
->node_zonelists
[0];
2229 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
2230 for (j
= 0; j
< nr_nodes
; j
++) {
2231 node
= node_order
[j
];
2232 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
2233 if (populated_zone(z
)) {
2235 &zonelist
->_zonerefs
[pos
++]);
2236 check_highest_zone(zone_type
);
2240 zonelist
->_zonerefs
[pos
].zone
= NULL
;
2241 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
2244 static int default_zonelist_order(void)
2247 unsigned long low_kmem_size
,total_size
;
2251 * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem.
2252 * If they are really small and used heavily, the system can fall
2253 * into OOM very easily.
2254 * This function detect ZONE_DMA/DMA32 size and confgigures zone order.
2256 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
2259 for_each_online_node(nid
) {
2260 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2261 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2262 if (populated_zone(z
)) {
2263 if (zone_type
< ZONE_NORMAL
)
2264 low_kmem_size
+= z
->present_pages
;
2265 total_size
+= z
->present_pages
;
2269 if (!low_kmem_size
|| /* there are no DMA area. */
2270 low_kmem_size
> total_size
/2) /* DMA/DMA32 is big. */
2271 return ZONELIST_ORDER_NODE
;
2273 * look into each node's config.
2274 * If there is a node whose DMA/DMA32 memory is very big area on
2275 * local memory, NODE_ORDER may be suitable.
2277 average_size
= total_size
/
2278 (nodes_weight(node_states
[N_HIGH_MEMORY
]) + 1);
2279 for_each_online_node(nid
) {
2282 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2283 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2284 if (populated_zone(z
)) {
2285 if (zone_type
< ZONE_NORMAL
)
2286 low_kmem_size
+= z
->present_pages
;
2287 total_size
+= z
->present_pages
;
2290 if (low_kmem_size
&&
2291 total_size
> average_size
&& /* ignore small node */
2292 low_kmem_size
> total_size
* 70/100)
2293 return ZONELIST_ORDER_NODE
;
2295 return ZONELIST_ORDER_ZONE
;
2298 static void set_zonelist_order(void)
2300 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
2301 current_zonelist_order
= default_zonelist_order();
2303 current_zonelist_order
= user_zonelist_order
;
2306 static void build_zonelists(pg_data_t
*pgdat
)
2310 nodemask_t used_mask
;
2311 int local_node
, prev_node
;
2312 struct zonelist
*zonelist
;
2313 int order
= current_zonelist_order
;
2315 /* initialize zonelists */
2316 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
2317 zonelist
= pgdat
->node_zonelists
+ i
;
2318 zonelist
->_zonerefs
[0].zone
= NULL
;
2319 zonelist
->_zonerefs
[0].zone_idx
= 0;
2322 /* NUMA-aware ordering of nodes */
2323 local_node
= pgdat
->node_id
;
2324 load
= num_online_nodes();
2325 prev_node
= local_node
;
2326 nodes_clear(used_mask
);
2328 memset(node_load
, 0, sizeof(node_load
));
2329 memset(node_order
, 0, sizeof(node_order
));
2332 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
2333 int distance
= node_distance(local_node
, node
);
2336 * If another node is sufficiently far away then it is better
2337 * to reclaim pages in a zone before going off node.
2339 if (distance
> RECLAIM_DISTANCE
)
2340 zone_reclaim_mode
= 1;
2343 * We don't want to pressure a particular node.
2344 * So adding penalty to the first node in same
2345 * distance group to make it round-robin.
2347 if (distance
!= node_distance(local_node
, prev_node
))
2348 node_load
[node
] = load
;
2352 if (order
== ZONELIST_ORDER_NODE
)
2353 build_zonelists_in_node_order(pgdat
, node
);
2355 node_order
[j
++] = node
; /* remember order */
2358 if (order
== ZONELIST_ORDER_ZONE
) {
2359 /* calculate node order -- i.e., DMA last! */
2360 build_zonelists_in_zone_order(pgdat
, j
);
2363 build_thisnode_zonelists(pgdat
);
2366 /* Construct the zonelist performance cache - see further mmzone.h */
2367 static void build_zonelist_cache(pg_data_t
*pgdat
)
2369 struct zonelist
*zonelist
;
2370 struct zonelist_cache
*zlc
;
2373 zonelist
= &pgdat
->node_zonelists
[0];
2374 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
2375 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
2376 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
2377 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
2381 #else /* CONFIG_NUMA */
2383 static void set_zonelist_order(void)
2385 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
2388 static void build_zonelists(pg_data_t
*pgdat
)
2390 int node
, local_node
;
2392 struct zonelist
*zonelist
;
2394 local_node
= pgdat
->node_id
;
2396 zonelist
= &pgdat
->node_zonelists
[0];
2397 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
2400 * Now we build the zonelist so that it contains the zones
2401 * of all the other nodes.
2402 * We don't want to pressure a particular node, so when
2403 * building the zones for node N, we make sure that the
2404 * zones coming right after the local ones are those from
2405 * node N+1 (modulo N)
2407 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
2408 if (!node_online(node
))
2410 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2413 for (node
= 0; node
< local_node
; node
++) {
2414 if (!node_online(node
))
2416 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2420 zonelist
->_zonerefs
[j
].zone
= NULL
;
2421 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2424 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2425 static void build_zonelist_cache(pg_data_t
*pgdat
)
2427 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
2430 #endif /* CONFIG_NUMA */
2432 /* return values int ....just for stop_machine() */
2433 static int __build_all_zonelists(void *dummy
)
2437 for_each_online_node(nid
) {
2438 pg_data_t
*pgdat
= NODE_DATA(nid
);
2440 build_zonelists(pgdat
);
2441 build_zonelist_cache(pgdat
);
2446 void build_all_zonelists(void)
2448 set_zonelist_order();
2450 if (system_state
== SYSTEM_BOOTING
) {
2451 __build_all_zonelists(NULL
);
2452 mminit_verify_zonelist();
2453 cpuset_init_current_mems_allowed();
2455 /* we have to stop all cpus to guarantee there is no user
2457 stop_machine(__build_all_zonelists
, NULL
, NULL
);
2458 /* cpuset refresh routine should be here */
2460 vm_total_pages
= nr_free_pagecache_pages();
2462 * Disable grouping by mobility if the number of pages in the
2463 * system is too low to allow the mechanism to work. It would be
2464 * more accurate, but expensive to check per-zone. This check is
2465 * made on memory-hotadd so a system can start with mobility
2466 * disabled and enable it later
2468 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
2469 page_group_by_mobility_disabled
= 1;
2471 page_group_by_mobility_disabled
= 0;
2473 printk("Built %i zonelists in %s order, mobility grouping %s. "
2474 "Total pages: %ld\n",
2476 zonelist_order_name
[current_zonelist_order
],
2477 page_group_by_mobility_disabled
? "off" : "on",
2480 printk("Policy zone: %s\n", zone_names
[policy_zone
]);
2485 * Helper functions to size the waitqueue hash table.
2486 * Essentially these want to choose hash table sizes sufficiently
2487 * large so that collisions trying to wait on pages are rare.
2488 * But in fact, the number of active page waitqueues on typical
2489 * systems is ridiculously low, less than 200. So this is even
2490 * conservative, even though it seems large.
2492 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
2493 * waitqueues, i.e. the size of the waitq table given the number of pages.
2495 #define PAGES_PER_WAITQUEUE 256
2497 #ifndef CONFIG_MEMORY_HOTPLUG
2498 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
2500 unsigned long size
= 1;
2502 pages
/= PAGES_PER_WAITQUEUE
;
2504 while (size
< pages
)
2508 * Once we have dozens or even hundreds of threads sleeping
2509 * on IO we've got bigger problems than wait queue collision.
2510 * Limit the size of the wait table to a reasonable size.
2512 size
= min(size
, 4096UL);
2514 return max(size
, 4UL);
2518 * A zone's size might be changed by hot-add, so it is not possible to determine
2519 * a suitable size for its wait_table. So we use the maximum size now.
2521 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
2523 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
2524 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
2525 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
2527 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
2528 * or more by the traditional way. (See above). It equals:
2530 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
2531 * ia64(16K page size) : = ( 8G + 4M)byte.
2532 * powerpc (64K page size) : = (32G +16M)byte.
2534 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
2541 * This is an integer logarithm so that shifts can be used later
2542 * to extract the more random high bits from the multiplicative
2543 * hash function before the remainder is taken.
2545 static inline unsigned long wait_table_bits(unsigned long size
)
2550 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
2553 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2554 * of blocks reserved is based on zone->pages_min. The memory within the
2555 * reserve will tend to store contiguous free pages. Setting min_free_kbytes
2556 * higher will lead to a bigger reserve which will get freed as contiguous
2557 * blocks as reclaim kicks in
2559 static void setup_zone_migrate_reserve(struct zone
*zone
)
2561 unsigned long start_pfn
, pfn
, end_pfn
;
2563 unsigned long reserve
, block_migratetype
;
2565 /* Get the start pfn, end pfn and the number of blocks to reserve */
2566 start_pfn
= zone
->zone_start_pfn
;
2567 end_pfn
= start_pfn
+ zone
->spanned_pages
;
2568 reserve
= roundup(zone
->pages_min
, pageblock_nr_pages
) >>
2571 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
2572 if (!pfn_valid(pfn
))
2574 page
= pfn_to_page(pfn
);
2576 /* Watch out for overlapping nodes */
2577 if (page_to_nid(page
) != zone_to_nid(zone
))
2580 /* Blocks with reserved pages will never free, skip them. */
2581 if (PageReserved(page
))
2584 block_migratetype
= get_pageblock_migratetype(page
);
2586 /* If this block is reserved, account for it */
2587 if (reserve
> 0 && block_migratetype
== MIGRATE_RESERVE
) {
2592 /* Suitable for reserving if this block is movable */
2593 if (reserve
> 0 && block_migratetype
== MIGRATE_MOVABLE
) {
2594 set_pageblock_migratetype(page
, MIGRATE_RESERVE
);
2595 move_freepages_block(zone
, page
, MIGRATE_RESERVE
);
2601 * If the reserve is met and this is a previous reserved block,
2604 if (block_migratetype
== MIGRATE_RESERVE
) {
2605 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
2606 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
2612 * Initially all pages are reserved - free ones are freed
2613 * up by free_all_bootmem() once the early boot process is
2614 * done. Non-atomic initialization, single-pass.
2616 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
2617 unsigned long start_pfn
, enum memmap_context context
)
2620 unsigned long end_pfn
= start_pfn
+ size
;
2624 if (highest_memmap_pfn
< end_pfn
- 1)
2625 highest_memmap_pfn
= end_pfn
- 1;
2627 z
= &NODE_DATA(nid
)->node_zones
[zone
];
2628 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
2630 * There can be holes in boot-time mem_map[]s
2631 * handed to this function. They do not
2632 * exist on hotplugged memory.
2634 if (context
== MEMMAP_EARLY
) {
2635 if (!early_pfn_valid(pfn
))
2637 if (!early_pfn_in_nid(pfn
, nid
))
2640 page
= pfn_to_page(pfn
);
2641 set_page_links(page
, zone
, nid
, pfn
);
2642 mminit_verify_page_links(page
, zone
, nid
, pfn
);
2643 init_page_count(page
);
2644 reset_page_mapcount(page
);
2645 SetPageReserved(page
);
2647 * Mark the block movable so that blocks are reserved for
2648 * movable at startup. This will force kernel allocations
2649 * to reserve their blocks rather than leaking throughout
2650 * the address space during boot when many long-lived
2651 * kernel allocations are made. Later some blocks near
2652 * the start are marked MIGRATE_RESERVE by
2653 * setup_zone_migrate_reserve()
2655 * bitmap is created for zone's valid pfn range. but memmap
2656 * can be created for invalid pages (for alignment)
2657 * check here not to call set_pageblock_migratetype() against
2660 if ((z
->zone_start_pfn
<= pfn
)
2661 && (pfn
< z
->zone_start_pfn
+ z
->spanned_pages
)
2662 && !(pfn
& (pageblock_nr_pages
- 1)))
2663 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
2665 INIT_LIST_HEAD(&page
->lru
);
2666 #ifdef WANT_PAGE_VIRTUAL
2667 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
2668 if (!is_highmem_idx(zone
))
2669 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
2674 static void __meminit
zone_init_free_lists(struct zone
*zone
)
2677 for_each_migratetype_order(order
, t
) {
2678 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
2679 zone
->free_area
[order
].nr_free
= 0;
2683 #ifndef __HAVE_ARCH_MEMMAP_INIT
2684 #define memmap_init(size, nid, zone, start_pfn) \
2685 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
2688 static int zone_batchsize(struct zone
*zone
)
2693 * The per-cpu-pages pools are set to around 1000th of the
2694 * size of the zone. But no more than 1/2 of a meg.
2696 * OK, so we don't know how big the cache is. So guess.
2698 batch
= zone
->present_pages
/ 1024;
2699 if (batch
* PAGE_SIZE
> 512 * 1024)
2700 batch
= (512 * 1024) / PAGE_SIZE
;
2701 batch
/= 4; /* We effectively *= 4 below */
2706 * Clamp the batch to a 2^n - 1 value. Having a power
2707 * of 2 value was found to be more likely to have
2708 * suboptimal cache aliasing properties in some cases.
2710 * For example if 2 tasks are alternately allocating
2711 * batches of pages, one task can end up with a lot
2712 * of pages of one half of the possible page colors
2713 * and the other with pages of the other colors.
2715 batch
= (1 << (fls(batch
+ batch
/2)-1)) - 1;
2720 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
2722 struct per_cpu_pages
*pcp
;
2724 memset(p
, 0, sizeof(*p
));
2728 pcp
->high
= 6 * batch
;
2729 pcp
->batch
= max(1UL, 1 * batch
);
2730 INIT_LIST_HEAD(&pcp
->list
);
2734 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
2735 * to the value high for the pageset p.
2738 static void setup_pagelist_highmark(struct per_cpu_pageset
*p
,
2741 struct per_cpu_pages
*pcp
;
2745 pcp
->batch
= max(1UL, high
/4);
2746 if ((high
/4) > (PAGE_SHIFT
* 8))
2747 pcp
->batch
= PAGE_SHIFT
* 8;
2753 * Boot pageset table. One per cpu which is going to be used for all
2754 * zones and all nodes. The parameters will be set in such a way
2755 * that an item put on a list will immediately be handed over to
2756 * the buddy list. This is safe since pageset manipulation is done
2757 * with interrupts disabled.
2759 * Some NUMA counter updates may also be caught by the boot pagesets.
2761 * The boot_pagesets must be kept even after bootup is complete for
2762 * unused processors and/or zones. They do play a role for bootstrapping
2763 * hotplugged processors.
2765 * zoneinfo_show() and maybe other functions do
2766 * not check if the processor is online before following the pageset pointer.
2767 * Other parts of the kernel may not check if the zone is available.
2769 static struct per_cpu_pageset boot_pageset
[NR_CPUS
];
2772 * Dynamically allocate memory for the
2773 * per cpu pageset array in struct zone.
2775 static int __cpuinit
process_zones(int cpu
)
2777 struct zone
*zone
, *dzone
;
2778 int node
= cpu_to_node(cpu
);
2780 node_set_state(node
, N_CPU
); /* this node has a cpu */
2782 for_each_zone(zone
) {
2784 if (!populated_zone(zone
))
2787 zone_pcp(zone
, cpu
) = kmalloc_node(sizeof(struct per_cpu_pageset
),
2789 if (!zone_pcp(zone
, cpu
))
2792 setup_pageset(zone_pcp(zone
, cpu
), zone_batchsize(zone
));
2794 if (percpu_pagelist_fraction
)
2795 setup_pagelist_highmark(zone_pcp(zone
, cpu
),
2796 (zone
->present_pages
/ percpu_pagelist_fraction
));
2801 for_each_zone(dzone
) {
2802 if (!populated_zone(dzone
))
2806 kfree(zone_pcp(dzone
, cpu
));
2807 zone_pcp(dzone
, cpu
) = NULL
;
2812 static inline void free_zone_pagesets(int cpu
)
2816 for_each_zone(zone
) {
2817 struct per_cpu_pageset
*pset
= zone_pcp(zone
, cpu
);
2819 /* Free per_cpu_pageset if it is slab allocated */
2820 if (pset
!= &boot_pageset
[cpu
])
2822 zone_pcp(zone
, cpu
) = NULL
;
2826 static int __cpuinit
pageset_cpuup_callback(struct notifier_block
*nfb
,
2827 unsigned long action
,
2830 int cpu
= (long)hcpu
;
2831 int ret
= NOTIFY_OK
;
2834 case CPU_UP_PREPARE
:
2835 case CPU_UP_PREPARE_FROZEN
:
2836 if (process_zones(cpu
))
2839 case CPU_UP_CANCELED
:
2840 case CPU_UP_CANCELED_FROZEN
:
2842 case CPU_DEAD_FROZEN
:
2843 free_zone_pagesets(cpu
);
2851 static struct notifier_block __cpuinitdata pageset_notifier
=
2852 { &pageset_cpuup_callback
, NULL
, 0 };
2854 void __init
setup_per_cpu_pageset(void)
2858 /* Initialize per_cpu_pageset for cpu 0.
2859 * A cpuup callback will do this for every cpu
2860 * as it comes online
2862 err
= process_zones(smp_processor_id());
2864 register_cpu_notifier(&pageset_notifier
);
2869 static noinline __init_refok
2870 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
2873 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
2877 * The per-page waitqueue mechanism uses hashed waitqueues
2880 zone
->wait_table_hash_nr_entries
=
2881 wait_table_hash_nr_entries(zone_size_pages
);
2882 zone
->wait_table_bits
=
2883 wait_table_bits(zone
->wait_table_hash_nr_entries
);
2884 alloc_size
= zone
->wait_table_hash_nr_entries
2885 * sizeof(wait_queue_head_t
);
2887 if (!slab_is_available()) {
2888 zone
->wait_table
= (wait_queue_head_t
*)
2889 alloc_bootmem_node(pgdat
, alloc_size
);
2892 * This case means that a zone whose size was 0 gets new memory
2893 * via memory hot-add.
2894 * But it may be the case that a new node was hot-added. In
2895 * this case vmalloc() will not be able to use this new node's
2896 * memory - this wait_table must be initialized to use this new
2897 * node itself as well.
2898 * To use this new node's memory, further consideration will be
2901 zone
->wait_table
= vmalloc(alloc_size
);
2903 if (!zone
->wait_table
)
2906 for(i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
2907 init_waitqueue_head(zone
->wait_table
+ i
);
2912 static __meminit
void zone_pcp_init(struct zone
*zone
)
2915 unsigned long batch
= zone_batchsize(zone
);
2917 for (cpu
= 0; cpu
< NR_CPUS
; cpu
++) {
2919 /* Early boot. Slab allocator not functional yet */
2920 zone_pcp(zone
, cpu
) = &boot_pageset
[cpu
];
2921 setup_pageset(&boot_pageset
[cpu
],0);
2923 setup_pageset(zone_pcp(zone
,cpu
), batch
);
2926 if (zone
->present_pages
)
2927 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%lu\n",
2928 zone
->name
, zone
->present_pages
, batch
);
2931 __meminit
int init_currently_empty_zone(struct zone
*zone
,
2932 unsigned long zone_start_pfn
,
2934 enum memmap_context context
)
2936 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
2938 ret
= zone_wait_table_init(zone
, size
);
2941 pgdat
->nr_zones
= zone_idx(zone
) + 1;
2943 zone
->zone_start_pfn
= zone_start_pfn
;
2945 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
2946 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
2948 (unsigned long)zone_idx(zone
),
2949 zone_start_pfn
, (zone_start_pfn
+ size
));
2951 zone_init_free_lists(zone
);
2956 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
2958 * Basic iterator support. Return the first range of PFNs for a node
2959 * Note: nid == MAX_NUMNODES returns first region regardless of node
2961 static int __meminit
first_active_region_index_in_nid(int nid
)
2965 for (i
= 0; i
< nr_nodemap_entries
; i
++)
2966 if (nid
== MAX_NUMNODES
|| early_node_map
[i
].nid
== nid
)
2973 * Basic iterator support. Return the next active range of PFNs for a node
2974 * Note: nid == MAX_NUMNODES returns next region regardless of node
2976 static int __meminit
next_active_region_index_in_nid(int index
, int nid
)
2978 for (index
= index
+ 1; index
< nr_nodemap_entries
; index
++)
2979 if (nid
== MAX_NUMNODES
|| early_node_map
[index
].nid
== nid
)
2985 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
2987 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
2988 * Architectures may implement their own version but if add_active_range()
2989 * was used and there are no special requirements, this is a convenient
2992 int __meminit
__early_pfn_to_nid(unsigned long pfn
)
2996 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
2997 unsigned long start_pfn
= early_node_map
[i
].start_pfn
;
2998 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
3000 if (start_pfn
<= pfn
&& pfn
< end_pfn
)
3001 return early_node_map
[i
].nid
;
3006 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
3008 int __meminit
early_pfn_to_nid(unsigned long pfn
)
3010 return __early_pfn_to_nid(pfn
);
3014 /* Basic iterator support to walk early_node_map[] */
3015 #define for_each_active_range_index_in_nid(i, nid) \
3016 for (i = first_active_region_index_in_nid(nid); i != -1; \
3017 i = next_active_region_index_in_nid(i, nid))
3020 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
3021 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
3022 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
3024 * If an architecture guarantees that all ranges registered with
3025 * add_active_ranges() contain no holes and may be freed, this
3026 * this function may be used instead of calling free_bootmem() manually.
3028 void __init
free_bootmem_with_active_regions(int nid
,
3029 unsigned long max_low_pfn
)
3033 for_each_active_range_index_in_nid(i
, nid
) {
3034 unsigned long size_pages
= 0;
3035 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
3037 if (early_node_map
[i
].start_pfn
>= max_low_pfn
)
3040 if (end_pfn
> max_low_pfn
)
3041 end_pfn
= max_low_pfn
;
3043 size_pages
= end_pfn
- early_node_map
[i
].start_pfn
;
3044 free_bootmem_node(NODE_DATA(early_node_map
[i
].nid
),
3045 PFN_PHYS(early_node_map
[i
].start_pfn
),
3046 size_pages
<< PAGE_SHIFT
);
3050 void __init
work_with_active_regions(int nid
, work_fn_t work_fn
, void *data
)
3055 for_each_active_range_index_in_nid(i
, nid
) {
3056 ret
= work_fn(early_node_map
[i
].start_pfn
,
3057 early_node_map
[i
].end_pfn
, data
);
3063 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3064 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3066 * If an architecture guarantees that all ranges registered with
3067 * add_active_ranges() contain no holes and may be freed, this
3068 * function may be used instead of calling memory_present() manually.
3070 void __init
sparse_memory_present_with_active_regions(int nid
)
3074 for_each_active_range_index_in_nid(i
, nid
)
3075 memory_present(early_node_map
[i
].nid
,
3076 early_node_map
[i
].start_pfn
,
3077 early_node_map
[i
].end_pfn
);
3081 * push_node_boundaries - Push node boundaries to at least the requested boundary
3082 * @nid: The nid of the node to push the boundary for
3083 * @start_pfn: The start pfn of the node
3084 * @end_pfn: The end pfn of the node
3086 * In reserve-based hot-add, mem_map is allocated that is unused until hotadd
3087 * time. Specifically, on x86_64, SRAT will report ranges that can potentially
3088 * be hotplugged even though no physical memory exists. This function allows
3089 * an arch to push out the node boundaries so mem_map is allocated that can
3092 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
3093 void __init
push_node_boundaries(unsigned int nid
,
3094 unsigned long start_pfn
, unsigned long end_pfn
)
3096 mminit_dprintk(MMINIT_TRACE
, "zoneboundary",
3097 "Entering push_node_boundaries(%u, %lu, %lu)\n",
3098 nid
, start_pfn
, end_pfn
);
3100 /* Initialise the boundary for this node if necessary */
3101 if (node_boundary_end_pfn
[nid
] == 0)
3102 node_boundary_start_pfn
[nid
] = -1UL;
3104 /* Update the boundaries */
3105 if (node_boundary_start_pfn
[nid
] > start_pfn
)
3106 node_boundary_start_pfn
[nid
] = start_pfn
;
3107 if (node_boundary_end_pfn
[nid
] < end_pfn
)
3108 node_boundary_end_pfn
[nid
] = end_pfn
;
3111 /* If necessary, push the node boundary out for reserve hotadd */
3112 static void __meminit
account_node_boundary(unsigned int nid
,
3113 unsigned long *start_pfn
, unsigned long *end_pfn
)
3115 mminit_dprintk(MMINIT_TRACE
, "zoneboundary",
3116 "Entering account_node_boundary(%u, %lu, %lu)\n",
3117 nid
, *start_pfn
, *end_pfn
);
3119 /* Return if boundary information has not been provided */
3120 if (node_boundary_end_pfn
[nid
] == 0)
3123 /* Check the boundaries and update if necessary */
3124 if (node_boundary_start_pfn
[nid
] < *start_pfn
)
3125 *start_pfn
= node_boundary_start_pfn
[nid
];
3126 if (node_boundary_end_pfn
[nid
] > *end_pfn
)
3127 *end_pfn
= node_boundary_end_pfn
[nid
];
3130 void __init
push_node_boundaries(unsigned int nid
,
3131 unsigned long start_pfn
, unsigned long end_pfn
) {}
3133 static void __meminit
account_node_boundary(unsigned int nid
,
3134 unsigned long *start_pfn
, unsigned long *end_pfn
) {}
3139 * get_pfn_range_for_nid - Return the start and end page frames for a node
3140 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
3141 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
3142 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
3144 * It returns the start and end page frame of a node based on information
3145 * provided by an arch calling add_active_range(). If called for a node
3146 * with no available memory, a warning is printed and the start and end
3149 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
3150 unsigned long *start_pfn
, unsigned long *end_pfn
)
3156 for_each_active_range_index_in_nid(i
, nid
) {
3157 *start_pfn
= min(*start_pfn
, early_node_map
[i
].start_pfn
);
3158 *end_pfn
= max(*end_pfn
, early_node_map
[i
].end_pfn
);
3161 if (*start_pfn
== -1UL)
3164 /* Push the node boundaries out if requested */
3165 account_node_boundary(nid
, start_pfn
, end_pfn
);
3169 * This finds a zone that can be used for ZONE_MOVABLE pages. The
3170 * assumption is made that zones within a node are ordered in monotonic
3171 * increasing memory addresses so that the "highest" populated zone is used
3173 static void __init
find_usable_zone_for_movable(void)
3176 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
3177 if (zone_index
== ZONE_MOVABLE
)
3180 if (arch_zone_highest_possible_pfn
[zone_index
] >
3181 arch_zone_lowest_possible_pfn
[zone_index
])
3185 VM_BUG_ON(zone_index
== -1);
3186 movable_zone
= zone_index
;
3190 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
3191 * because it is sized independant of architecture. Unlike the other zones,
3192 * the starting point for ZONE_MOVABLE is not fixed. It may be different
3193 * in each node depending on the size of each node and how evenly kernelcore
3194 * is distributed. This helper function adjusts the zone ranges
3195 * provided by the architecture for a given node by using the end of the
3196 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
3197 * zones within a node are in order of monotonic increases memory addresses
3199 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
3200 unsigned long zone_type
,
3201 unsigned long node_start_pfn
,
3202 unsigned long node_end_pfn
,
3203 unsigned long *zone_start_pfn
,
3204 unsigned long *zone_end_pfn
)
3206 /* Only adjust if ZONE_MOVABLE is on this node */
3207 if (zone_movable_pfn
[nid
]) {
3208 /* Size ZONE_MOVABLE */
3209 if (zone_type
== ZONE_MOVABLE
) {
3210 *zone_start_pfn
= zone_movable_pfn
[nid
];
3211 *zone_end_pfn
= min(node_end_pfn
,
3212 arch_zone_highest_possible_pfn
[movable_zone
]);
3214 /* Adjust for ZONE_MOVABLE starting within this range */
3215 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
3216 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
3217 *zone_end_pfn
= zone_movable_pfn
[nid
];
3219 /* Check if this whole range is within ZONE_MOVABLE */
3220 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
3221 *zone_start_pfn
= *zone_end_pfn
;
3226 * Return the number of pages a zone spans in a node, including holes
3227 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
3229 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3230 unsigned long zone_type
,
3231 unsigned long *ignored
)
3233 unsigned long node_start_pfn
, node_end_pfn
;
3234 unsigned long zone_start_pfn
, zone_end_pfn
;
3236 /* Get the start and end of the node and zone */
3237 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3238 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
3239 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
3240 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3241 node_start_pfn
, node_end_pfn
,
3242 &zone_start_pfn
, &zone_end_pfn
);
3244 /* Check that this node has pages within the zone's required range */
3245 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
3248 /* Move the zone boundaries inside the node if necessary */
3249 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
3250 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
3252 /* Return the spanned pages */
3253 return zone_end_pfn
- zone_start_pfn
;
3257 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
3258 * then all holes in the requested range will be accounted for.
3260 static unsigned long __meminit
__absent_pages_in_range(int nid
,
3261 unsigned long range_start_pfn
,
3262 unsigned long range_end_pfn
)
3265 unsigned long prev_end_pfn
= 0, hole_pages
= 0;
3266 unsigned long start_pfn
;
3268 /* Find the end_pfn of the first active range of pfns in the node */
3269 i
= first_active_region_index_in_nid(nid
);
3273 prev_end_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3275 /* Account for ranges before physical memory on this node */
3276 if (early_node_map
[i
].start_pfn
> range_start_pfn
)
3277 hole_pages
= prev_end_pfn
- range_start_pfn
;
3279 /* Find all holes for the zone within the node */
3280 for (; i
!= -1; i
= next_active_region_index_in_nid(i
, nid
)) {
3282 /* No need to continue if prev_end_pfn is outside the zone */
3283 if (prev_end_pfn
>= range_end_pfn
)
3286 /* Make sure the end of the zone is not within the hole */
3287 start_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3288 prev_end_pfn
= max(prev_end_pfn
, range_start_pfn
);
3290 /* Update the hole size cound and move on */
3291 if (start_pfn
> range_start_pfn
) {
3292 BUG_ON(prev_end_pfn
> start_pfn
);
3293 hole_pages
+= start_pfn
- prev_end_pfn
;
3295 prev_end_pfn
= early_node_map
[i
].end_pfn
;
3298 /* Account for ranges past physical memory on this node */
3299 if (range_end_pfn
> prev_end_pfn
)
3300 hole_pages
+= range_end_pfn
-
3301 max(range_start_pfn
, prev_end_pfn
);
3307 * absent_pages_in_range - Return number of page frames in holes within a range
3308 * @start_pfn: The start PFN to start searching for holes
3309 * @end_pfn: The end PFN to stop searching for holes
3311 * It returns the number of pages frames in memory holes within a range.
3313 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
3314 unsigned long end_pfn
)
3316 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
3319 /* Return the number of page frames in holes in a zone on a node */
3320 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
3321 unsigned long zone_type
,
3322 unsigned long *ignored
)
3324 unsigned long node_start_pfn
, node_end_pfn
;
3325 unsigned long zone_start_pfn
, zone_end_pfn
;
3327 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3328 zone_start_pfn
= max(arch_zone_lowest_possible_pfn
[zone_type
],
3330 zone_end_pfn
= min(arch_zone_highest_possible_pfn
[zone_type
],
3333 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3334 node_start_pfn
, node_end_pfn
,
3335 &zone_start_pfn
, &zone_end_pfn
);
3336 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
3340 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3341 unsigned long zone_type
,
3342 unsigned long *zones_size
)
3344 return zones_size
[zone_type
];
3347 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
3348 unsigned long zone_type
,
3349 unsigned long *zholes_size
)
3354 return zholes_size
[zone_type
];
3359 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
3360 unsigned long *zones_size
, unsigned long *zholes_size
)
3362 unsigned long realtotalpages
, totalpages
= 0;
3365 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3366 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
3368 pgdat
->node_spanned_pages
= totalpages
;
3370 realtotalpages
= totalpages
;
3371 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3373 zone_absent_pages_in_node(pgdat
->node_id
, i
,
3375 pgdat
->node_present_pages
= realtotalpages
;
3376 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
3380 #ifndef CONFIG_SPARSEMEM
3382 * Calculate the size of the zone->blockflags rounded to an unsigned long
3383 * Start by making sure zonesize is a multiple of pageblock_order by rounding
3384 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
3385 * round what is now in bits to nearest long in bits, then return it in
3388 static unsigned long __init
usemap_size(unsigned long zonesize
)
3390 unsigned long usemapsize
;
3392 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
3393 usemapsize
= usemapsize
>> pageblock_order
;
3394 usemapsize
*= NR_PAGEBLOCK_BITS
;
3395 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
3397 return usemapsize
/ 8;
3400 static void __init
setup_usemap(struct pglist_data
*pgdat
,
3401 struct zone
*zone
, unsigned long zonesize
)
3403 unsigned long usemapsize
= usemap_size(zonesize
);
3404 zone
->pageblock_flags
= NULL
;
3406 zone
->pageblock_flags
= alloc_bootmem_node(pgdat
, usemapsize
);
3409 static void inline setup_usemap(struct pglist_data
*pgdat
,
3410 struct zone
*zone
, unsigned long zonesize
) {}
3411 #endif /* CONFIG_SPARSEMEM */
3413 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3415 /* Return a sensible default order for the pageblock size. */
3416 static inline int pageblock_default_order(void)
3418 if (HPAGE_SHIFT
> PAGE_SHIFT
)
3419 return HUGETLB_PAGE_ORDER
;
3424 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
3425 static inline void __init
set_pageblock_order(unsigned int order
)
3427 /* Check that pageblock_nr_pages has not already been setup */
3428 if (pageblock_order
)
3432 * Assume the largest contiguous order of interest is a huge page.
3433 * This value may be variable depending on boot parameters on IA64
3435 pageblock_order
= order
;
3437 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3440 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
3441 * and pageblock_default_order() are unused as pageblock_order is set
3442 * at compile-time. See include/linux/pageblock-flags.h for the values of
3443 * pageblock_order based on the kernel config
3445 static inline int pageblock_default_order(unsigned int order
)
3449 #define set_pageblock_order(x) do {} while (0)
3451 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3454 * Set up the zone data structures:
3455 * - mark all pages reserved
3456 * - mark all memory queues empty
3457 * - clear the memory bitmaps
3459 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
,
3460 unsigned long *zones_size
, unsigned long *zholes_size
)
3463 int nid
= pgdat
->node_id
;
3464 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
3467 pgdat_resize_init(pgdat
);
3468 pgdat
->nr_zones
= 0;
3469 init_waitqueue_head(&pgdat
->kswapd_wait
);
3470 pgdat
->kswapd_max_order
= 0;
3471 pgdat_page_cgroup_init(pgdat
);
3473 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
3474 struct zone
*zone
= pgdat
->node_zones
+ j
;
3475 unsigned long size
, realsize
, memmap_pages
;
3478 size
= zone_spanned_pages_in_node(nid
, j
, zones_size
);
3479 realsize
= size
- zone_absent_pages_in_node(nid
, j
,
3483 * Adjust realsize so that it accounts for how much memory
3484 * is used by this zone for memmap. This affects the watermark
3485 * and per-cpu initialisations
3488 PAGE_ALIGN(size
* sizeof(struct page
)) >> PAGE_SHIFT
;
3489 if (realsize
>= memmap_pages
) {
3490 realsize
-= memmap_pages
;
3493 " %s zone: %lu pages used for memmap\n",
3494 zone_names
[j
], memmap_pages
);
3497 " %s zone: %lu pages exceeds realsize %lu\n",
3498 zone_names
[j
], memmap_pages
, realsize
);
3500 /* Account for reserved pages */
3501 if (j
== 0 && realsize
> dma_reserve
) {
3502 realsize
-= dma_reserve
;
3503 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
3504 zone_names
[0], dma_reserve
);
3507 if (!is_highmem_idx(j
))
3508 nr_kernel_pages
+= realsize
;
3509 nr_all_pages
+= realsize
;
3511 zone
->spanned_pages
= size
;
3512 zone
->present_pages
= realsize
;
3515 zone
->min_unmapped_pages
= (realsize
*sysctl_min_unmapped_ratio
)
3517 zone
->min_slab_pages
= (realsize
* sysctl_min_slab_ratio
) / 100;
3519 zone
->name
= zone_names
[j
];
3520 spin_lock_init(&zone
->lock
);
3521 spin_lock_init(&zone
->lru_lock
);
3522 zone_seqlock_init(zone
);
3523 zone
->zone_pgdat
= pgdat
;
3525 zone
->prev_priority
= DEF_PRIORITY
;
3527 zone_pcp_init(zone
);
3529 INIT_LIST_HEAD(&zone
->lru
[l
].list
);
3530 zone
->lru
[l
].nr_scan
= 0;
3532 zone
->reclaim_stat
.recent_rotated
[0] = 0;
3533 zone
->reclaim_stat
.recent_rotated
[1] = 0;
3534 zone
->reclaim_stat
.recent_scanned
[0] = 0;
3535 zone
->reclaim_stat
.recent_scanned
[1] = 0;
3536 zap_zone_vm_stats(zone
);
3541 set_pageblock_order(pageblock_default_order());
3542 setup_usemap(pgdat
, zone
, size
);
3543 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
3544 size
, MEMMAP_EARLY
);
3546 memmap_init(size
, nid
, j
, zone_start_pfn
);
3547 zone_start_pfn
+= size
;
3551 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
3553 /* Skip empty nodes */
3554 if (!pgdat
->node_spanned_pages
)
3557 #ifdef CONFIG_FLAT_NODE_MEM_MAP
3558 /* ia64 gets its own node_mem_map, before this, without bootmem */
3559 if (!pgdat
->node_mem_map
) {
3560 unsigned long size
, start
, end
;
3564 * The zone's endpoints aren't required to be MAX_ORDER
3565 * aligned but the node_mem_map endpoints must be in order
3566 * for the buddy allocator to function correctly.
3568 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
3569 end
= pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
3570 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
3571 size
= (end
- start
) * sizeof(struct page
);
3572 map
= alloc_remap(pgdat
->node_id
, size
);
3574 map
= alloc_bootmem_node(pgdat
, size
);
3575 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
3577 #ifndef CONFIG_NEED_MULTIPLE_NODES
3579 * With no DISCONTIG, the global mem_map is just set as node 0's
3581 if (pgdat
== NODE_DATA(0)) {
3582 mem_map
= NODE_DATA(0)->node_mem_map
;
3583 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3584 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
3585 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
3586 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
3589 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
3592 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
3593 unsigned long node_start_pfn
, unsigned long *zholes_size
)
3595 pg_data_t
*pgdat
= NODE_DATA(nid
);
3597 pgdat
->node_id
= nid
;
3598 pgdat
->node_start_pfn
= node_start_pfn
;
3599 calculate_node_totalpages(pgdat
, zones_size
, zholes_size
);
3601 alloc_node_mem_map(pgdat
);
3602 #ifdef CONFIG_FLAT_NODE_MEM_MAP
3603 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
3604 nid
, (unsigned long)pgdat
,
3605 (unsigned long)pgdat
->node_mem_map
);
3608 free_area_init_core(pgdat
, zones_size
, zholes_size
);
3611 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3613 #if MAX_NUMNODES > 1
3615 * Figure out the number of possible node ids.
3617 static void __init
setup_nr_node_ids(void)
3620 unsigned int highest
= 0;
3622 for_each_node_mask(node
, node_possible_map
)
3624 nr_node_ids
= highest
+ 1;
3627 static inline void setup_nr_node_ids(void)
3633 * add_active_range - Register a range of PFNs backed by physical memory
3634 * @nid: The node ID the range resides on
3635 * @start_pfn: The start PFN of the available physical memory
3636 * @end_pfn: The end PFN of the available physical memory
3638 * These ranges are stored in an early_node_map[] and later used by
3639 * free_area_init_nodes() to calculate zone sizes and holes. If the
3640 * range spans a memory hole, it is up to the architecture to ensure
3641 * the memory is not freed by the bootmem allocator. If possible
3642 * the range being registered will be merged with existing ranges.
3644 void __init
add_active_range(unsigned int nid
, unsigned long start_pfn
,
3645 unsigned long end_pfn
)
3649 mminit_dprintk(MMINIT_TRACE
, "memory_register",
3650 "Entering add_active_range(%d, %#lx, %#lx) "
3651 "%d entries of %d used\n",
3652 nid
, start_pfn
, end_pfn
,
3653 nr_nodemap_entries
, MAX_ACTIVE_REGIONS
);
3655 mminit_validate_memmodel_limits(&start_pfn
, &end_pfn
);
3657 /* Merge with existing active regions if possible */
3658 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
3659 if (early_node_map
[i
].nid
!= nid
)
3662 /* Skip if an existing region covers this new one */
3663 if (start_pfn
>= early_node_map
[i
].start_pfn
&&
3664 end_pfn
<= early_node_map
[i
].end_pfn
)
3667 /* Merge forward if suitable */
3668 if (start_pfn
<= early_node_map
[i
].end_pfn
&&
3669 end_pfn
> early_node_map
[i
].end_pfn
) {
3670 early_node_map
[i
].end_pfn
= end_pfn
;
3674 /* Merge backward if suitable */
3675 if (start_pfn
< early_node_map
[i
].end_pfn
&&
3676 end_pfn
>= early_node_map
[i
].start_pfn
) {
3677 early_node_map
[i
].start_pfn
= start_pfn
;
3682 /* Check that early_node_map is large enough */
3683 if (i
>= MAX_ACTIVE_REGIONS
) {
3684 printk(KERN_CRIT
"More than %d memory regions, truncating\n",
3685 MAX_ACTIVE_REGIONS
);
3689 early_node_map
[i
].nid
= nid
;
3690 early_node_map
[i
].start_pfn
= start_pfn
;
3691 early_node_map
[i
].end_pfn
= end_pfn
;
3692 nr_nodemap_entries
= i
+ 1;
3696 * remove_active_range - Shrink an existing registered range of PFNs
3697 * @nid: The node id the range is on that should be shrunk
3698 * @start_pfn: The new PFN of the range
3699 * @end_pfn: The new PFN of the range
3701 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
3702 * The map is kept near the end physical page range that has already been
3703 * registered. This function allows an arch to shrink an existing registered
3706 void __init
remove_active_range(unsigned int nid
, unsigned long start_pfn
,
3707 unsigned long end_pfn
)
3712 printk(KERN_DEBUG
"remove_active_range (%d, %lu, %lu)\n",
3713 nid
, start_pfn
, end_pfn
);
3715 /* Find the old active region end and shrink */
3716 for_each_active_range_index_in_nid(i
, nid
) {
3717 if (early_node_map
[i
].start_pfn
>= start_pfn
&&
3718 early_node_map
[i
].end_pfn
<= end_pfn
) {
3720 early_node_map
[i
].start_pfn
= 0;
3721 early_node_map
[i
].end_pfn
= 0;
3725 if (early_node_map
[i
].start_pfn
< start_pfn
&&
3726 early_node_map
[i
].end_pfn
> start_pfn
) {
3727 unsigned long temp_end_pfn
= early_node_map
[i
].end_pfn
;
3728 early_node_map
[i
].end_pfn
= start_pfn
;
3729 if (temp_end_pfn
> end_pfn
)
3730 add_active_range(nid
, end_pfn
, temp_end_pfn
);
3733 if (early_node_map
[i
].start_pfn
>= start_pfn
&&
3734 early_node_map
[i
].end_pfn
> end_pfn
&&
3735 early_node_map
[i
].start_pfn
< end_pfn
) {
3736 early_node_map
[i
].start_pfn
= end_pfn
;
3744 /* remove the blank ones */
3745 for (i
= nr_nodemap_entries
- 1; i
> 0; i
--) {
3746 if (early_node_map
[i
].nid
!= nid
)
3748 if (early_node_map
[i
].end_pfn
)
3750 /* we found it, get rid of it */
3751 for (j
= i
; j
< nr_nodemap_entries
- 1; j
++)
3752 memcpy(&early_node_map
[j
], &early_node_map
[j
+1],
3753 sizeof(early_node_map
[j
]));
3754 j
= nr_nodemap_entries
- 1;
3755 memset(&early_node_map
[j
], 0, sizeof(early_node_map
[j
]));
3756 nr_nodemap_entries
--;
3761 * remove_all_active_ranges - Remove all currently registered regions
3763 * During discovery, it may be found that a table like SRAT is invalid
3764 * and an alternative discovery method must be used. This function removes
3765 * all currently registered regions.
3767 void __init
remove_all_active_ranges(void)
3769 memset(early_node_map
, 0, sizeof(early_node_map
));
3770 nr_nodemap_entries
= 0;
3771 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
3772 memset(node_boundary_start_pfn
, 0, sizeof(node_boundary_start_pfn
));
3773 memset(node_boundary_end_pfn
, 0, sizeof(node_boundary_end_pfn
));
3774 #endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
3777 /* Compare two active node_active_regions */
3778 static int __init
cmp_node_active_region(const void *a
, const void *b
)
3780 struct node_active_region
*arange
= (struct node_active_region
*)a
;
3781 struct node_active_region
*brange
= (struct node_active_region
*)b
;
3783 /* Done this way to avoid overflows */
3784 if (arange
->start_pfn
> brange
->start_pfn
)
3786 if (arange
->start_pfn
< brange
->start_pfn
)
3792 /* sort the node_map by start_pfn */
3793 static void __init
sort_node_map(void)
3795 sort(early_node_map
, (size_t)nr_nodemap_entries
,
3796 sizeof(struct node_active_region
),
3797 cmp_node_active_region
, NULL
);
3800 /* Find the lowest pfn for a node */
3801 static unsigned long __init
find_min_pfn_for_node(int nid
)
3804 unsigned long min_pfn
= ULONG_MAX
;
3806 /* Assuming a sorted map, the first range found has the starting pfn */
3807 for_each_active_range_index_in_nid(i
, nid
)
3808 min_pfn
= min(min_pfn
, early_node_map
[i
].start_pfn
);
3810 if (min_pfn
== ULONG_MAX
) {
3812 "Could not find start_pfn for node %d\n", nid
);
3820 * find_min_pfn_with_active_regions - Find the minimum PFN registered
3822 * It returns the minimum PFN based on information provided via
3823 * add_active_range().
3825 unsigned long __init
find_min_pfn_with_active_regions(void)
3827 return find_min_pfn_for_node(MAX_NUMNODES
);
3831 * early_calculate_totalpages()
3832 * Sum pages in active regions for movable zone.
3833 * Populate N_HIGH_MEMORY for calculating usable_nodes.
3835 static unsigned long __init
early_calculate_totalpages(void)
3838 unsigned long totalpages
= 0;
3840 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
3841 unsigned long pages
= early_node_map
[i
].end_pfn
-
3842 early_node_map
[i
].start_pfn
;
3843 totalpages
+= pages
;
3845 node_set_state(early_node_map
[i
].nid
, N_HIGH_MEMORY
);
3851 * Find the PFN the Movable zone begins in each node. Kernel memory
3852 * is spread evenly between nodes as long as the nodes have enough
3853 * memory. When they don't, some nodes will have more kernelcore than
3856 static void __init
find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn
)
3859 unsigned long usable_startpfn
;
3860 unsigned long kernelcore_node
, kernelcore_remaining
;
3861 unsigned long totalpages
= early_calculate_totalpages();
3862 int usable_nodes
= nodes_weight(node_states
[N_HIGH_MEMORY
]);
3865 * If movablecore was specified, calculate what size of
3866 * kernelcore that corresponds so that memory usable for
3867 * any allocation type is evenly spread. If both kernelcore
3868 * and movablecore are specified, then the value of kernelcore
3869 * will be used for required_kernelcore if it's greater than
3870 * what movablecore would have allowed.
3872 if (required_movablecore
) {
3873 unsigned long corepages
;
3876 * Round-up so that ZONE_MOVABLE is at least as large as what
3877 * was requested by the user
3879 required_movablecore
=
3880 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
3881 corepages
= totalpages
- required_movablecore
;
3883 required_kernelcore
= max(required_kernelcore
, corepages
);
3886 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
3887 if (!required_kernelcore
)
3890 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
3891 find_usable_zone_for_movable();
3892 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
3895 /* Spread kernelcore memory as evenly as possible throughout nodes */
3896 kernelcore_node
= required_kernelcore
/ usable_nodes
;
3897 for_each_node_state(nid
, N_HIGH_MEMORY
) {
3899 * Recalculate kernelcore_node if the division per node
3900 * now exceeds what is necessary to satisfy the requested
3901 * amount of memory for the kernel
3903 if (required_kernelcore
< kernelcore_node
)
3904 kernelcore_node
= required_kernelcore
/ usable_nodes
;
3907 * As the map is walked, we track how much memory is usable
3908 * by the kernel using kernelcore_remaining. When it is
3909 * 0, the rest of the node is usable by ZONE_MOVABLE
3911 kernelcore_remaining
= kernelcore_node
;
3913 /* Go through each range of PFNs within this node */
3914 for_each_active_range_index_in_nid(i
, nid
) {
3915 unsigned long start_pfn
, end_pfn
;
3916 unsigned long size_pages
;
3918 start_pfn
= max(early_node_map
[i
].start_pfn
,
3919 zone_movable_pfn
[nid
]);
3920 end_pfn
= early_node_map
[i
].end_pfn
;
3921 if (start_pfn
>= end_pfn
)
3924 /* Account for what is only usable for kernelcore */
3925 if (start_pfn
< usable_startpfn
) {
3926 unsigned long kernel_pages
;
3927 kernel_pages
= min(end_pfn
, usable_startpfn
)
3930 kernelcore_remaining
-= min(kernel_pages
,
3931 kernelcore_remaining
);
3932 required_kernelcore
-= min(kernel_pages
,
3933 required_kernelcore
);
3935 /* Continue if range is now fully accounted */
3936 if (end_pfn
<= usable_startpfn
) {
3939 * Push zone_movable_pfn to the end so
3940 * that if we have to rebalance
3941 * kernelcore across nodes, we will
3942 * not double account here
3944 zone_movable_pfn
[nid
] = end_pfn
;
3947 start_pfn
= usable_startpfn
;
3951 * The usable PFN range for ZONE_MOVABLE is from
3952 * start_pfn->end_pfn. Calculate size_pages as the
3953 * number of pages used as kernelcore
3955 size_pages
= end_pfn
- start_pfn
;
3956 if (size_pages
> kernelcore_remaining
)
3957 size_pages
= kernelcore_remaining
;
3958 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
3961 * Some kernelcore has been met, update counts and
3962 * break if the kernelcore for this node has been
3965 required_kernelcore
-= min(required_kernelcore
,
3967 kernelcore_remaining
-= size_pages
;
3968 if (!kernelcore_remaining
)
3974 * If there is still required_kernelcore, we do another pass with one
3975 * less node in the count. This will push zone_movable_pfn[nid] further
3976 * along on the nodes that still have memory until kernelcore is
3980 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
3983 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
3984 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
3985 zone_movable_pfn
[nid
] =
3986 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
3989 /* Any regular memory on that node ? */
3990 static void check_for_regular_memory(pg_data_t
*pgdat
)
3992 #ifdef CONFIG_HIGHMEM
3993 enum zone_type zone_type
;
3995 for (zone_type
= 0; zone_type
<= ZONE_NORMAL
; zone_type
++) {
3996 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
3997 if (zone
->present_pages
)
3998 node_set_state(zone_to_nid(zone
), N_NORMAL_MEMORY
);
4004 * free_area_init_nodes - Initialise all pg_data_t and zone data
4005 * @max_zone_pfn: an array of max PFNs for each zone
4007 * This will call free_area_init_node() for each active node in the system.
4008 * Using the page ranges provided by add_active_range(), the size of each
4009 * zone in each node and their holes is calculated. If the maximum PFN
4010 * between two adjacent zones match, it is assumed that the zone is empty.
4011 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
4012 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
4013 * starts where the previous one ended. For example, ZONE_DMA32 starts
4014 * at arch_max_dma_pfn.
4016 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
4021 /* Sort early_node_map as initialisation assumes it is sorted */
4024 /* Record where the zone boundaries are */
4025 memset(arch_zone_lowest_possible_pfn
, 0,
4026 sizeof(arch_zone_lowest_possible_pfn
));
4027 memset(arch_zone_highest_possible_pfn
, 0,
4028 sizeof(arch_zone_highest_possible_pfn
));
4029 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
4030 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
4031 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
4032 if (i
== ZONE_MOVABLE
)
4034 arch_zone_lowest_possible_pfn
[i
] =
4035 arch_zone_highest_possible_pfn
[i
-1];
4036 arch_zone_highest_possible_pfn
[i
] =
4037 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
4039 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
4040 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
4042 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
4043 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
4044 find_zone_movable_pfns_for_nodes(zone_movable_pfn
);
4046 /* Print out the zone ranges */
4047 printk("Zone PFN ranges:\n");
4048 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4049 if (i
== ZONE_MOVABLE
)
4051 printk(" %-8s %0#10lx -> %0#10lx\n",
4053 arch_zone_lowest_possible_pfn
[i
],
4054 arch_zone_highest_possible_pfn
[i
]);
4057 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
4058 printk("Movable zone start PFN for each node\n");
4059 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
4060 if (zone_movable_pfn
[i
])
4061 printk(" Node %d: %lu\n", i
, zone_movable_pfn
[i
]);
4064 /* Print out the early_node_map[] */
4065 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries
);
4066 for (i
= 0; i
< nr_nodemap_entries
; i
++)
4067 printk(" %3d: %0#10lx -> %0#10lx\n", early_node_map
[i
].nid
,
4068 early_node_map
[i
].start_pfn
,
4069 early_node_map
[i
].end_pfn
);
4071 /* Initialise every node */
4072 mminit_verify_pageflags_layout();
4073 setup_nr_node_ids();
4074 for_each_online_node(nid
) {
4075 pg_data_t
*pgdat
= NODE_DATA(nid
);
4076 free_area_init_node(nid
, NULL
,
4077 find_min_pfn_for_node(nid
), NULL
);
4079 /* Any memory on that node */
4080 if (pgdat
->node_present_pages
)
4081 node_set_state(nid
, N_HIGH_MEMORY
);
4082 check_for_regular_memory(pgdat
);
4086 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
4088 unsigned long long coremem
;
4092 coremem
= memparse(p
, &p
);
4093 *core
= coremem
>> PAGE_SHIFT
;
4095 /* Paranoid check that UL is enough for the coremem value */
4096 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
4102 * kernelcore=size sets the amount of memory for use for allocations that
4103 * cannot be reclaimed or migrated.
4105 static int __init
cmdline_parse_kernelcore(char *p
)
4107 return cmdline_parse_core(p
, &required_kernelcore
);
4111 * movablecore=size sets the amount of memory for use for allocations that
4112 * can be reclaimed or migrated.
4114 static int __init
cmdline_parse_movablecore(char *p
)
4116 return cmdline_parse_core(p
, &required_movablecore
);
4119 early_param("kernelcore", cmdline_parse_kernelcore
);
4120 early_param("movablecore", cmdline_parse_movablecore
);
4122 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
4125 * set_dma_reserve - set the specified number of pages reserved in the first zone
4126 * @new_dma_reserve: The number of pages to mark reserved
4128 * The per-cpu batchsize and zone watermarks are determined by present_pages.
4129 * In the DMA zone, a significant percentage may be consumed by kernel image
4130 * and other unfreeable allocations which can skew the watermarks badly. This
4131 * function may optionally be used to account for unfreeable pages in the
4132 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
4133 * smaller per-cpu batchsize.
4135 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
4137 dma_reserve
= new_dma_reserve
;
4140 #ifndef CONFIG_NEED_MULTIPLE_NODES
4141 struct pglist_data __refdata contig_page_data
= { .bdata
= &bootmem_node_data
[0] };
4142 EXPORT_SYMBOL(contig_page_data
);
4145 void __init
free_area_init(unsigned long *zones_size
)
4147 free_area_init_node(0, zones_size
,
4148 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
4151 static int page_alloc_cpu_notify(struct notifier_block
*self
,
4152 unsigned long action
, void *hcpu
)
4154 int cpu
= (unsigned long)hcpu
;
4156 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
4160 * Spill the event counters of the dead processor
4161 * into the current processors event counters.
4162 * This artificially elevates the count of the current
4165 vm_events_fold_cpu(cpu
);
4168 * Zero the differential counters of the dead processor
4169 * so that the vm statistics are consistent.
4171 * This is only okay since the processor is dead and cannot
4172 * race with what we are doing.
4174 refresh_cpu_vm_stats(cpu
);
4179 void __init
page_alloc_init(void)
4181 hotcpu_notifier(page_alloc_cpu_notify
, 0);
4185 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
4186 * or min_free_kbytes changes.
4188 static void calculate_totalreserve_pages(void)
4190 struct pglist_data
*pgdat
;
4191 unsigned long reserve_pages
= 0;
4192 enum zone_type i
, j
;
4194 for_each_online_pgdat(pgdat
) {
4195 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4196 struct zone
*zone
= pgdat
->node_zones
+ i
;
4197 unsigned long max
= 0;
4199 /* Find valid and maximum lowmem_reserve in the zone */
4200 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
4201 if (zone
->lowmem_reserve
[j
] > max
)
4202 max
= zone
->lowmem_reserve
[j
];
4205 /* we treat pages_high as reserved pages. */
4206 max
+= zone
->pages_high
;
4208 if (max
> zone
->present_pages
)
4209 max
= zone
->present_pages
;
4210 reserve_pages
+= max
;
4213 totalreserve_pages
= reserve_pages
;
4217 * setup_per_zone_lowmem_reserve - called whenever
4218 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
4219 * has a correct pages reserved value, so an adequate number of
4220 * pages are left in the zone after a successful __alloc_pages().
4222 static void setup_per_zone_lowmem_reserve(void)
4224 struct pglist_data
*pgdat
;
4225 enum zone_type j
, idx
;
4227 for_each_online_pgdat(pgdat
) {
4228 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4229 struct zone
*zone
= pgdat
->node_zones
+ j
;
4230 unsigned long present_pages
= zone
->present_pages
;
4232 zone
->lowmem_reserve
[j
] = 0;
4236 struct zone
*lower_zone
;
4240 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
4241 sysctl_lowmem_reserve_ratio
[idx
] = 1;
4243 lower_zone
= pgdat
->node_zones
+ idx
;
4244 lower_zone
->lowmem_reserve
[j
] = present_pages
/
4245 sysctl_lowmem_reserve_ratio
[idx
];
4246 present_pages
+= lower_zone
->present_pages
;
4251 /* update totalreserve_pages */
4252 calculate_totalreserve_pages();
4256 * setup_per_zone_pages_min - called when min_free_kbytes changes.
4258 * Ensures that the pages_{min,low,high} values for each zone are set correctly
4259 * with respect to min_free_kbytes.
4261 void setup_per_zone_pages_min(void)
4263 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
4264 unsigned long lowmem_pages
= 0;
4266 unsigned long flags
;
4268 /* Calculate total number of !ZONE_HIGHMEM pages */
4269 for_each_zone(zone
) {
4270 if (!is_highmem(zone
))
4271 lowmem_pages
+= zone
->present_pages
;
4274 for_each_zone(zone
) {
4277 spin_lock_irqsave(&zone
->lock
, flags
);
4278 tmp
= (u64
)pages_min
* zone
->present_pages
;
4279 do_div(tmp
, lowmem_pages
);
4280 if (is_highmem(zone
)) {
4282 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
4283 * need highmem pages, so cap pages_min to a small
4286 * The (pages_high-pages_low) and (pages_low-pages_min)
4287 * deltas controls asynch page reclaim, and so should
4288 * not be capped for highmem.
4292 min_pages
= zone
->present_pages
/ 1024;
4293 if (min_pages
< SWAP_CLUSTER_MAX
)
4294 min_pages
= SWAP_CLUSTER_MAX
;
4295 if (min_pages
> 128)
4297 zone
->pages_min
= min_pages
;
4300 * If it's a lowmem zone, reserve a number of pages
4301 * proportionate to the zone's size.
4303 zone
->pages_min
= tmp
;
4306 zone
->pages_low
= zone
->pages_min
+ (tmp
>> 2);
4307 zone
->pages_high
= zone
->pages_min
+ (tmp
>> 1);
4308 setup_zone_migrate_reserve(zone
);
4309 spin_unlock_irqrestore(&zone
->lock
, flags
);
4312 /* update totalreserve_pages */
4313 calculate_totalreserve_pages();
4317 * setup_per_zone_inactive_ratio - called when min_free_kbytes changes.
4319 * The inactive anon list should be small enough that the VM never has to
4320 * do too much work, but large enough that each inactive page has a chance
4321 * to be referenced again before it is swapped out.
4323 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
4324 * INACTIVE_ANON pages on this zone's LRU, maintained by the
4325 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
4326 * the anonymous pages are kept on the inactive list.
4329 * memory ratio inactive anon
4330 * -------------------------------------
4339 static void setup_per_zone_inactive_ratio(void)
4343 for_each_zone(zone
) {
4344 unsigned int gb
, ratio
;
4346 /* Zone size in gigabytes */
4347 gb
= zone
->present_pages
>> (30 - PAGE_SHIFT
);
4348 ratio
= int_sqrt(10 * gb
);
4352 zone
->inactive_ratio
= ratio
;
4357 * Initialise min_free_kbytes.
4359 * For small machines we want it small (128k min). For large machines
4360 * we want it large (64MB max). But it is not linear, because network
4361 * bandwidth does not increase linearly with machine size. We use
4363 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
4364 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
4380 static int __init
init_per_zone_pages_min(void)
4382 unsigned long lowmem_kbytes
;
4384 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
4386 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
4387 if (min_free_kbytes
< 128)
4388 min_free_kbytes
= 128;
4389 if (min_free_kbytes
> 65536)
4390 min_free_kbytes
= 65536;
4391 setup_per_zone_pages_min();
4392 setup_per_zone_lowmem_reserve();
4393 setup_per_zone_inactive_ratio();
4396 module_init(init_per_zone_pages_min
)
4399 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
4400 * that we can call two helper functions whenever min_free_kbytes
4403 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
4404 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4406 proc_dointvec(table
, write
, file
, buffer
, length
, ppos
);
4408 setup_per_zone_pages_min();
4413 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
4414 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4419 rc
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4424 zone
->min_unmapped_pages
= (zone
->present_pages
*
4425 sysctl_min_unmapped_ratio
) / 100;
4429 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
4430 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4435 rc
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4440 zone
->min_slab_pages
= (zone
->present_pages
*
4441 sysctl_min_slab_ratio
) / 100;
4447 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
4448 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
4449 * whenever sysctl_lowmem_reserve_ratio changes.
4451 * The reserve ratio obviously has absolutely no relation with the
4452 * pages_min watermarks. The lowmem reserve ratio can only make sense
4453 * if in function of the boot time zone sizes.
4455 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
4456 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4458 proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4459 setup_per_zone_lowmem_reserve();
4464 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
4465 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
4466 * can have before it gets flushed back to buddy allocator.
4469 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
4470 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4476 ret
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4477 if (!write
|| (ret
== -EINVAL
))
4479 for_each_zone(zone
) {
4480 for_each_online_cpu(cpu
) {
4482 high
= zone
->present_pages
/ percpu_pagelist_fraction
;
4483 setup_pagelist_highmark(zone_pcp(zone
, cpu
), high
);
4489 int hashdist
= HASHDIST_DEFAULT
;
4492 static int __init
set_hashdist(char *str
)
4496 hashdist
= simple_strtoul(str
, &str
, 0);
4499 __setup("hashdist=", set_hashdist
);
4503 * allocate a large system hash table from bootmem
4504 * - it is assumed that the hash table must contain an exact power-of-2
4505 * quantity of entries
4506 * - limit is the number of hash buckets, not the total allocation size
4508 void *__init
alloc_large_system_hash(const char *tablename
,
4509 unsigned long bucketsize
,
4510 unsigned long numentries
,
4513 unsigned int *_hash_shift
,
4514 unsigned int *_hash_mask
,
4515 unsigned long limit
)
4517 unsigned long long max
= limit
;
4518 unsigned long log2qty
, size
;
4521 /* allow the kernel cmdline to have a say */
4523 /* round applicable memory size up to nearest megabyte */
4524 numentries
= nr_kernel_pages
;
4525 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
4526 numentries
>>= 20 - PAGE_SHIFT
;
4527 numentries
<<= 20 - PAGE_SHIFT
;
4529 /* limit to 1 bucket per 2^scale bytes of low memory */
4530 if (scale
> PAGE_SHIFT
)
4531 numentries
>>= (scale
- PAGE_SHIFT
);
4533 numentries
<<= (PAGE_SHIFT
- scale
);
4535 /* Make sure we've got at least a 0-order allocation.. */
4536 if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
4537 numentries
= PAGE_SIZE
/ bucketsize
;
4539 numentries
= roundup_pow_of_two(numentries
);
4541 /* limit allocation size to 1/16 total memory by default */
4543 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
4544 do_div(max
, bucketsize
);
4547 if (numentries
> max
)
4550 log2qty
= ilog2(numentries
);
4553 size
= bucketsize
<< log2qty
;
4554 if (flags
& HASH_EARLY
)
4555 table
= alloc_bootmem_nopanic(size
);
4557 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
4559 unsigned long order
= get_order(size
);
4560 table
= (void*) __get_free_pages(GFP_ATOMIC
, order
);
4562 * If bucketsize is not a power-of-two, we may free
4563 * some pages at the end of hash table.
4566 unsigned long alloc_end
= (unsigned long)table
+
4567 (PAGE_SIZE
<< order
);
4568 unsigned long used
= (unsigned long)table
+
4570 split_page(virt_to_page(table
), order
);
4571 while (used
< alloc_end
) {
4577 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
4580 panic("Failed to allocate %s hash table\n", tablename
);
4582 printk(KERN_INFO
"%s hash table entries: %d (order: %d, %lu bytes)\n",
4585 ilog2(size
) - PAGE_SHIFT
,
4589 *_hash_shift
= log2qty
;
4591 *_hash_mask
= (1 << log2qty
) - 1;
4596 /* Return a pointer to the bitmap storing bits affecting a block of pages */
4597 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
4600 #ifdef CONFIG_SPARSEMEM
4601 return __pfn_to_section(pfn
)->pageblock_flags
;
4603 return zone
->pageblock_flags
;
4604 #endif /* CONFIG_SPARSEMEM */
4607 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
4609 #ifdef CONFIG_SPARSEMEM
4610 pfn
&= (PAGES_PER_SECTION
-1);
4611 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
4613 pfn
= pfn
- zone
->zone_start_pfn
;
4614 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
4615 #endif /* CONFIG_SPARSEMEM */
4619 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4620 * @page: The page within the block of interest
4621 * @start_bitidx: The first bit of interest to retrieve
4622 * @end_bitidx: The last bit of interest
4623 * returns pageblock_bits flags
4625 unsigned long get_pageblock_flags_group(struct page
*page
,
4626 int start_bitidx
, int end_bitidx
)
4629 unsigned long *bitmap
;
4630 unsigned long pfn
, bitidx
;
4631 unsigned long flags
= 0;
4632 unsigned long value
= 1;
4634 zone
= page_zone(page
);
4635 pfn
= page_to_pfn(page
);
4636 bitmap
= get_pageblock_bitmap(zone
, pfn
);
4637 bitidx
= pfn_to_bitidx(zone
, pfn
);
4639 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
4640 if (test_bit(bitidx
+ start_bitidx
, bitmap
))
4647 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
4648 * @page: The page within the block of interest
4649 * @start_bitidx: The first bit of interest
4650 * @end_bitidx: The last bit of interest
4651 * @flags: The flags to set
4653 void set_pageblock_flags_group(struct page
*page
, unsigned long flags
,
4654 int start_bitidx
, int end_bitidx
)
4657 unsigned long *bitmap
;
4658 unsigned long pfn
, bitidx
;
4659 unsigned long value
= 1;
4661 zone
= page_zone(page
);
4662 pfn
= page_to_pfn(page
);
4663 bitmap
= get_pageblock_bitmap(zone
, pfn
);
4664 bitidx
= pfn_to_bitidx(zone
, pfn
);
4665 VM_BUG_ON(pfn
< zone
->zone_start_pfn
);
4666 VM_BUG_ON(pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
);
4668 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
4670 __set_bit(bitidx
+ start_bitidx
, bitmap
);
4672 __clear_bit(bitidx
+ start_bitidx
, bitmap
);
4676 * This is designed as sub function...plz see page_isolation.c also.
4677 * set/clear page block's type to be ISOLATE.
4678 * page allocater never alloc memory from ISOLATE block.
4681 int set_migratetype_isolate(struct page
*page
)
4684 unsigned long flags
;
4687 zone
= page_zone(page
);
4688 spin_lock_irqsave(&zone
->lock
, flags
);
4690 * In future, more migrate types will be able to be isolation target.
4692 if (get_pageblock_migratetype(page
) != MIGRATE_MOVABLE
)
4694 set_pageblock_migratetype(page
, MIGRATE_ISOLATE
);
4695 move_freepages_block(zone
, page
, MIGRATE_ISOLATE
);
4698 spin_unlock_irqrestore(&zone
->lock
, flags
);
4704 void unset_migratetype_isolate(struct page
*page
)
4707 unsigned long flags
;
4708 zone
= page_zone(page
);
4709 spin_lock_irqsave(&zone
->lock
, flags
);
4710 if (get_pageblock_migratetype(page
) != MIGRATE_ISOLATE
)
4712 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4713 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
4715 spin_unlock_irqrestore(&zone
->lock
, flags
);
4718 #ifdef CONFIG_MEMORY_HOTREMOVE
4720 * All pages in the range must be isolated before calling this.
4723 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
4729 unsigned long flags
;
4730 /* find the first valid pfn */
4731 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
4736 zone
= page_zone(pfn_to_page(pfn
));
4737 spin_lock_irqsave(&zone
->lock
, flags
);
4739 while (pfn
< end_pfn
) {
4740 if (!pfn_valid(pfn
)) {
4744 page
= pfn_to_page(pfn
);
4745 BUG_ON(page_count(page
));
4746 BUG_ON(!PageBuddy(page
));
4747 order
= page_order(page
);
4748 #ifdef CONFIG_DEBUG_VM
4749 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
4750 pfn
, 1 << order
, end_pfn
);
4752 list_del(&page
->lru
);
4753 rmv_page_order(page
);
4754 zone
->free_area
[order
].nr_free
--;
4755 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
4757 for (i
= 0; i
< (1 << order
); i
++)
4758 SetPageReserved((page
+i
));
4759 pfn
+= (1 << order
);
4761 spin_unlock_irqrestore(&zone
->lock
, flags
);