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/memcontrol.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
;
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 void *pc
= page_get_page_cgroup(page
);
228 printk(KERN_EMERG
"Bad page state in process '%s'\n" KERN_EMERG
229 "page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n",
230 current
->comm
, page
, (int)(2*sizeof(unsigned long)),
231 (unsigned long)page
->flags
, page
->mapping
,
232 page_mapcount(page
), page_count(page
));
234 printk(KERN_EMERG
"cgroup:%p\n", pc
);
235 page_reset_bad_cgroup(page
);
237 printk(KERN_EMERG
"Trying to fix it up, but a reboot is needed\n"
238 KERN_EMERG
"Backtrace:\n");
240 page
->flags
&= ~PAGE_FLAGS_CLEAR_WHEN_BAD
;
241 set_page_count(page
, 0);
242 reset_page_mapcount(page
);
243 page
->mapping
= NULL
;
244 add_taint(TAINT_BAD_PAGE
);
248 * Higher-order pages are called "compound pages". They are structured thusly:
250 * The first PAGE_SIZE page is called the "head page".
252 * The remaining PAGE_SIZE pages are called "tail pages".
254 * All pages have PG_compound set. All pages have their ->private pointing at
255 * the head page (even the head page has this).
257 * The first tail page's ->lru.next holds the address of the compound page's
258 * put_page() function. Its ->lru.prev holds the order of allocation.
259 * This usage means that zero-order pages may not be compound.
262 static void free_compound_page(struct page
*page
)
264 __free_pages_ok(page
, compound_order(page
));
267 void prep_compound_page(struct page
*page
, unsigned long order
)
270 int nr_pages
= 1 << order
;
272 set_compound_page_dtor(page
, free_compound_page
);
273 set_compound_order(page
, order
);
275 for (i
= 1; i
< nr_pages
; i
++) {
276 struct page
*p
= page
+ i
;
279 p
->first_page
= page
;
283 #ifdef CONFIG_HUGETLBFS
284 void prep_compound_gigantic_page(struct page
*page
, unsigned long order
)
287 int nr_pages
= 1 << order
;
288 struct page
*p
= page
+ 1;
290 set_compound_page_dtor(page
, free_compound_page
);
291 set_compound_order(page
, order
);
293 for (i
= 1; i
< nr_pages
; i
++, p
= mem_map_next(p
, page
, i
)) {
295 p
->first_page
= page
;
300 static void destroy_compound_page(struct page
*page
, unsigned long order
)
303 int nr_pages
= 1 << order
;
305 if (unlikely(compound_order(page
) != order
))
308 if (unlikely(!PageHead(page
)))
310 __ClearPageHead(page
);
311 for (i
= 1; i
< nr_pages
; i
++) {
312 struct page
*p
= page
+ i
;
314 if (unlikely(!PageTail(p
) |
315 (p
->first_page
!= page
)))
321 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
326 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
327 * and __GFP_HIGHMEM from hard or soft interrupt context.
329 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
330 for (i
= 0; i
< (1 << order
); i
++)
331 clear_highpage(page
+ i
);
334 static inline void set_page_order(struct page
*page
, int order
)
336 set_page_private(page
, order
);
337 __SetPageBuddy(page
);
340 static inline void rmv_page_order(struct page
*page
)
342 __ClearPageBuddy(page
);
343 set_page_private(page
, 0);
347 * Locate the struct page for both the matching buddy in our
348 * pair (buddy1) and the combined O(n+1) page they form (page).
350 * 1) Any buddy B1 will have an order O twin B2 which satisfies
351 * the following equation:
353 * For example, if the starting buddy (buddy2) is #8 its order
355 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
357 * 2) Any buddy B will have an order O+1 parent P which
358 * satisfies the following equation:
361 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
363 static inline struct page
*
364 __page_find_buddy(struct page
*page
, unsigned long page_idx
, unsigned int order
)
366 unsigned long buddy_idx
= page_idx
^ (1 << order
);
368 return page
+ (buddy_idx
- page_idx
);
371 static inline unsigned long
372 __find_combined_index(unsigned long page_idx
, unsigned int order
)
374 return (page_idx
& ~(1 << order
));
378 * This function checks whether a page is free && is the buddy
379 * we can do coalesce a page and its buddy if
380 * (a) the buddy is not in a hole &&
381 * (b) the buddy is in the buddy system &&
382 * (c) a page and its buddy have the same order &&
383 * (d) a page and its buddy are in the same zone.
385 * For recording whether a page is in the buddy system, we use PG_buddy.
386 * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
388 * For recording page's order, we use page_private(page).
390 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
393 if (!pfn_valid_within(page_to_pfn(buddy
)))
396 if (page_zone_id(page
) != page_zone_id(buddy
))
399 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
400 BUG_ON(page_count(buddy
) != 0);
407 * Freeing function for a buddy system allocator.
409 * The concept of a buddy system is to maintain direct-mapped table
410 * (containing bit values) for memory blocks of various "orders".
411 * The bottom level table contains the map for the smallest allocatable
412 * units of memory (here, pages), and each level above it describes
413 * pairs of units from the levels below, hence, "buddies".
414 * At a high level, all that happens here is marking the table entry
415 * at the bottom level available, and propagating the changes upward
416 * as necessary, plus some accounting needed to play nicely with other
417 * parts of the VM system.
418 * At each level, we keep a list of pages, which are heads of continuous
419 * free pages of length of (1 << order) and marked with PG_buddy. Page's
420 * order is recorded in page_private(page) field.
421 * So when we are allocating or freeing one, we can derive the state of the
422 * other. That is, if we allocate a small block, and both were
423 * free, the remainder of the region must be split into blocks.
424 * If a block is freed, and its buddy is also free, then this
425 * triggers coalescing into a block of larger size.
430 static inline void __free_one_page(struct page
*page
,
431 struct zone
*zone
, unsigned int order
)
433 unsigned long page_idx
;
434 int order_size
= 1 << order
;
435 int migratetype
= get_pageblock_migratetype(page
);
437 if (unlikely(PageCompound(page
)))
438 destroy_compound_page(page
, order
);
440 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
442 VM_BUG_ON(page_idx
& (order_size
- 1));
443 VM_BUG_ON(bad_range(zone
, page
));
445 __mod_zone_page_state(zone
, NR_FREE_PAGES
, order_size
);
446 while (order
< MAX_ORDER
-1) {
447 unsigned long combined_idx
;
450 buddy
= __page_find_buddy(page
, page_idx
, order
);
451 if (!page_is_buddy(page
, buddy
, order
))
454 /* Our buddy is free, merge with it and move up one order. */
455 list_del(&buddy
->lru
);
456 zone
->free_area
[order
].nr_free
--;
457 rmv_page_order(buddy
);
458 combined_idx
= __find_combined_index(page_idx
, order
);
459 page
= page
+ (combined_idx
- page_idx
);
460 page_idx
= combined_idx
;
463 set_page_order(page
, order
);
465 &zone
->free_area
[order
].free_list
[migratetype
]);
466 zone
->free_area
[order
].nr_free
++;
469 static inline int free_pages_check(struct page
*page
)
471 if (unlikely(page_mapcount(page
) |
472 (page
->mapping
!= NULL
) |
473 (page_get_page_cgroup(page
) != NULL
) |
474 (page_count(page
) != 0) |
475 (page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)))
478 __ClearPageDirty(page
);
480 * For now, we report if PG_reserved was found set, but do not
481 * clear it, and do not free the page. But we shall soon need
482 * to do more, for when the ZERO_PAGE count wraps negative.
484 return PageReserved(page
);
488 * Frees a list of pages.
489 * Assumes all pages on list are in same zone, and of same order.
490 * count is the number of pages to free.
492 * If the zone was previously in an "all pages pinned" state then look to
493 * see if this freeing clears that state.
495 * And clear the zone's pages_scanned counter, to hold off the "all pages are
496 * pinned" detection logic.
498 static void free_pages_bulk(struct zone
*zone
, int count
,
499 struct list_head
*list
, int order
)
501 spin_lock(&zone
->lock
);
502 zone_clear_flag(zone
, ZONE_ALL_UNRECLAIMABLE
);
503 zone
->pages_scanned
= 0;
507 VM_BUG_ON(list_empty(list
));
508 page
= list_entry(list
->prev
, struct page
, lru
);
509 /* have to delete it as __free_one_page list manipulates */
510 list_del(&page
->lru
);
511 __free_one_page(page
, zone
, order
);
513 spin_unlock(&zone
->lock
);
516 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
)
518 spin_lock(&zone
->lock
);
519 zone_clear_flag(zone
, ZONE_ALL_UNRECLAIMABLE
);
520 zone
->pages_scanned
= 0;
521 __free_one_page(page
, zone
, order
);
522 spin_unlock(&zone
->lock
);
525 static void __free_pages_ok(struct page
*page
, unsigned int order
)
531 for (i
= 0 ; i
< (1 << order
) ; ++i
)
532 reserved
+= free_pages_check(page
+ i
);
536 if (!PageHighMem(page
)) {
537 debug_check_no_locks_freed(page_address(page
),PAGE_SIZE
<<order
);
538 debug_check_no_obj_freed(page_address(page
),
541 arch_free_page(page
, order
);
542 kernel_map_pages(page
, 1 << order
, 0);
544 local_irq_save(flags
);
545 __count_vm_events(PGFREE
, 1 << order
);
546 free_one_page(page_zone(page
), page
, order
);
547 local_irq_restore(flags
);
551 * permit the bootmem allocator to evade page validation on high-order frees
553 void __meminit
__free_pages_bootmem(struct page
*page
, unsigned int order
)
556 __ClearPageReserved(page
);
557 set_page_count(page
, 0);
558 set_page_refcounted(page
);
564 for (loop
= 0; loop
< BITS_PER_LONG
; loop
++) {
565 struct page
*p
= &page
[loop
];
567 if (loop
+ 1 < BITS_PER_LONG
)
569 __ClearPageReserved(p
);
570 set_page_count(p
, 0);
573 set_page_refcounted(page
);
574 __free_pages(page
, order
);
580 * The order of subdivision here is critical for the IO subsystem.
581 * Please do not alter this order without good reasons and regression
582 * testing. Specifically, as large blocks of memory are subdivided,
583 * the order in which smaller blocks are delivered depends on the order
584 * they're subdivided in this function. This is the primary factor
585 * influencing the order in which pages are delivered to the IO
586 * subsystem according to empirical testing, and this is also justified
587 * by considering the behavior of a buddy system containing a single
588 * large block of memory acted on by a series of small allocations.
589 * This behavior is a critical factor in sglist merging's success.
593 static inline void expand(struct zone
*zone
, struct page
*page
,
594 int low
, int high
, struct free_area
*area
,
597 unsigned long size
= 1 << high
;
603 VM_BUG_ON(bad_range(zone
, &page
[size
]));
604 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
606 set_page_order(&page
[size
], high
);
611 * This page is about to be returned from the page allocator
613 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
615 if (unlikely(page_mapcount(page
) |
616 (page
->mapping
!= NULL
) |
617 (page_get_page_cgroup(page
) != NULL
) |
618 (page_count(page
) != 0) |
619 (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)))
623 * For now, we report if PG_reserved was found set, but do not
624 * clear it, and do not allocate the page: as a safety net.
626 if (PageReserved(page
))
629 page
->flags
&= ~(1 << PG_uptodate
| 1 << PG_error
| 1 << PG_reclaim
|
630 1 << PG_referenced
| 1 << PG_arch_1
|
631 1 << PG_owner_priv_1
| 1 << PG_mappedtodisk
);
632 set_page_private(page
, 0);
633 set_page_refcounted(page
);
635 arch_alloc_page(page
, order
);
636 kernel_map_pages(page
, 1 << order
, 1);
638 if (gfp_flags
& __GFP_ZERO
)
639 prep_zero_page(page
, order
, gfp_flags
);
641 if (order
&& (gfp_flags
& __GFP_COMP
))
642 prep_compound_page(page
, order
);
648 * Go through the free lists for the given migratetype and remove
649 * the smallest available page from the freelists
651 static struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
654 unsigned int current_order
;
655 struct free_area
* area
;
658 /* Find a page of the appropriate size in the preferred list */
659 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
660 area
= &(zone
->free_area
[current_order
]);
661 if (list_empty(&area
->free_list
[migratetype
]))
664 page
= list_entry(area
->free_list
[migratetype
].next
,
666 list_del(&page
->lru
);
667 rmv_page_order(page
);
669 __mod_zone_page_state(zone
, NR_FREE_PAGES
, - (1UL << order
));
670 expand(zone
, page
, order
, current_order
, area
, migratetype
);
679 * This array describes the order lists are fallen back to when
680 * the free lists for the desirable migrate type are depleted
682 static int fallbacks
[MIGRATE_TYPES
][MIGRATE_TYPES
-1] = {
683 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
684 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
685 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
686 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
, MIGRATE_RESERVE
, MIGRATE_RESERVE
}, /* Never used */
690 * Move the free pages in a range to the free lists of the requested type.
691 * Note that start_page and end_pages are not aligned on a pageblock
692 * boundary. If alignment is required, use move_freepages_block()
694 static int move_freepages(struct zone
*zone
,
695 struct page
*start_page
, struct page
*end_page
,
702 #ifndef CONFIG_HOLES_IN_ZONE
704 * page_zone is not safe to call in this context when
705 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
706 * anyway as we check zone boundaries in move_freepages_block().
707 * Remove at a later date when no bug reports exist related to
708 * grouping pages by mobility
710 BUG_ON(page_zone(start_page
) != page_zone(end_page
));
713 for (page
= start_page
; page
<= end_page
;) {
714 /* Make sure we are not inadvertently changing nodes */
715 VM_BUG_ON(page_to_nid(page
) != zone_to_nid(zone
));
717 if (!pfn_valid_within(page_to_pfn(page
))) {
722 if (!PageBuddy(page
)) {
727 order
= page_order(page
);
728 list_del(&page
->lru
);
730 &zone
->free_area
[order
].free_list
[migratetype
]);
732 pages_moved
+= 1 << order
;
738 static int move_freepages_block(struct zone
*zone
, struct page
*page
,
741 unsigned long start_pfn
, end_pfn
;
742 struct page
*start_page
, *end_page
;
744 start_pfn
= page_to_pfn(page
);
745 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
746 start_page
= pfn_to_page(start_pfn
);
747 end_page
= start_page
+ pageblock_nr_pages
- 1;
748 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
750 /* Do not cross zone boundaries */
751 if (start_pfn
< zone
->zone_start_pfn
)
753 if (end_pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
756 return move_freepages(zone
, start_page
, end_page
, migratetype
);
759 /* Remove an element from the buddy allocator from the fallback list */
760 static struct page
*__rmqueue_fallback(struct zone
*zone
, int order
,
761 int start_migratetype
)
763 struct free_area
* area
;
768 /* Find the largest possible block of pages in the other list */
769 for (current_order
= MAX_ORDER
-1; current_order
>= order
;
771 for (i
= 0; i
< MIGRATE_TYPES
- 1; i
++) {
772 migratetype
= fallbacks
[start_migratetype
][i
];
774 /* MIGRATE_RESERVE handled later if necessary */
775 if (migratetype
== MIGRATE_RESERVE
)
778 area
= &(zone
->free_area
[current_order
]);
779 if (list_empty(&area
->free_list
[migratetype
]))
782 page
= list_entry(area
->free_list
[migratetype
].next
,
787 * If breaking a large block of pages, move all free
788 * pages to the preferred allocation list. If falling
789 * back for a reclaimable kernel allocation, be more
790 * agressive about taking ownership of free pages
792 if (unlikely(current_order
>= (pageblock_order
>> 1)) ||
793 start_migratetype
== MIGRATE_RECLAIMABLE
) {
795 pages
= move_freepages_block(zone
, page
,
798 /* Claim the whole block if over half of it is free */
799 if (pages
>= (1 << (pageblock_order
-1)))
800 set_pageblock_migratetype(page
,
803 migratetype
= start_migratetype
;
806 /* Remove the page from the freelists */
807 list_del(&page
->lru
);
808 rmv_page_order(page
);
809 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
812 if (current_order
== pageblock_order
)
813 set_pageblock_migratetype(page
,
816 expand(zone
, page
, order
, current_order
, area
, migratetype
);
821 /* Use MIGRATE_RESERVE rather than fail an allocation */
822 return __rmqueue_smallest(zone
, order
, MIGRATE_RESERVE
);
826 * Do the hard work of removing an element from the buddy allocator.
827 * Call me with the zone->lock already held.
829 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
834 page
= __rmqueue_smallest(zone
, order
, migratetype
);
837 page
= __rmqueue_fallback(zone
, order
, migratetype
);
843 * Obtain a specified number of elements from the buddy allocator, all under
844 * a single hold of the lock, for efficiency. Add them to the supplied list.
845 * Returns the number of new pages which were placed at *list.
847 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
848 unsigned long count
, struct list_head
*list
,
849 int migratetype
, int cold
)
853 spin_lock(&zone
->lock
);
854 for (i
= 0; i
< count
; ++i
) {
855 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
856 if (unlikely(page
== NULL
))
860 * Split buddy pages returned by expand() are received here
861 * in physical page order. The page is added to the callers and
862 * list and the list head then moves forward. From the callers
863 * perspective, the linked list is ordered by page number in
864 * some conditions. This is useful for IO devices that can
865 * merge IO requests if the physical pages are ordered
868 if (likely(cold
== 0))
869 list_add(&page
->lru
, list
);
871 list_add_tail(&page
->lru
, list
);
872 set_page_private(page
, migratetype
);
875 spin_unlock(&zone
->lock
);
881 * Called from the vmstat counter updater to drain pagesets of this
882 * currently executing processor on remote nodes after they have
885 * Note that this function must be called with the thread pinned to
886 * a single processor.
888 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
893 local_irq_save(flags
);
894 if (pcp
->count
>= pcp
->batch
)
895 to_drain
= pcp
->batch
;
897 to_drain
= pcp
->count
;
898 free_pages_bulk(zone
, to_drain
, &pcp
->list
, 0);
899 pcp
->count
-= to_drain
;
900 local_irq_restore(flags
);
905 * Drain pages of the indicated processor.
907 * The processor must either be the current processor and the
908 * thread pinned to the current processor or a processor that
911 static void drain_pages(unsigned int cpu
)
916 for_each_zone(zone
) {
917 struct per_cpu_pageset
*pset
;
918 struct per_cpu_pages
*pcp
;
920 if (!populated_zone(zone
))
923 pset
= zone_pcp(zone
, cpu
);
926 local_irq_save(flags
);
927 free_pages_bulk(zone
, pcp
->count
, &pcp
->list
, 0);
929 local_irq_restore(flags
);
934 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
936 void drain_local_pages(void *arg
)
938 drain_pages(smp_processor_id());
942 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
944 void drain_all_pages(void)
946 on_each_cpu(drain_local_pages
, NULL
, 1);
949 #ifdef CONFIG_HIBERNATION
951 void mark_free_pages(struct zone
*zone
)
953 unsigned long pfn
, max_zone_pfn
;
956 struct list_head
*curr
;
958 if (!zone
->spanned_pages
)
961 spin_lock_irqsave(&zone
->lock
, flags
);
963 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
964 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
965 if (pfn_valid(pfn
)) {
966 struct page
*page
= pfn_to_page(pfn
);
968 if (!swsusp_page_is_forbidden(page
))
969 swsusp_unset_page_free(page
);
972 for_each_migratetype_order(order
, t
) {
973 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
976 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
977 for (i
= 0; i
< (1UL << order
); i
++)
978 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
981 spin_unlock_irqrestore(&zone
->lock
, flags
);
983 #endif /* CONFIG_PM */
986 * Free a 0-order page
988 static void free_hot_cold_page(struct page
*page
, int cold
)
990 struct zone
*zone
= page_zone(page
);
991 struct per_cpu_pages
*pcp
;
995 page
->mapping
= NULL
;
996 if (free_pages_check(page
))
999 if (!PageHighMem(page
)) {
1000 debug_check_no_locks_freed(page_address(page
), PAGE_SIZE
);
1001 debug_check_no_obj_freed(page_address(page
), PAGE_SIZE
);
1003 arch_free_page(page
, 0);
1004 kernel_map_pages(page
, 1, 0);
1006 pcp
= &zone_pcp(zone
, get_cpu())->pcp
;
1007 local_irq_save(flags
);
1008 __count_vm_event(PGFREE
);
1010 list_add_tail(&page
->lru
, &pcp
->list
);
1012 list_add(&page
->lru
, &pcp
->list
);
1013 set_page_private(page
, get_pageblock_migratetype(page
));
1015 if (pcp
->count
>= pcp
->high
) {
1016 free_pages_bulk(zone
, pcp
->batch
, &pcp
->list
, 0);
1017 pcp
->count
-= pcp
->batch
;
1019 local_irq_restore(flags
);
1023 void free_hot_page(struct page
*page
)
1025 free_hot_cold_page(page
, 0);
1028 void free_cold_page(struct page
*page
)
1030 free_hot_cold_page(page
, 1);
1034 * split_page takes a non-compound higher-order page, and splits it into
1035 * n (1<<order) sub-pages: page[0..n]
1036 * Each sub-page must be freed individually.
1038 * Note: this is probably too low level an operation for use in drivers.
1039 * Please consult with lkml before using this in your driver.
1041 void split_page(struct page
*page
, unsigned int order
)
1045 VM_BUG_ON(PageCompound(page
));
1046 VM_BUG_ON(!page_count(page
));
1047 for (i
= 1; i
< (1 << order
); i
++)
1048 set_page_refcounted(page
+ i
);
1052 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1053 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1056 static struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
1057 struct zone
*zone
, int order
, gfp_t gfp_flags
)
1059 unsigned long flags
;
1061 int cold
= !!(gfp_flags
& __GFP_COLD
);
1063 int migratetype
= allocflags_to_migratetype(gfp_flags
);
1067 if (likely(order
== 0)) {
1068 struct per_cpu_pages
*pcp
;
1070 pcp
= &zone_pcp(zone
, cpu
)->pcp
;
1071 local_irq_save(flags
);
1073 pcp
->count
= rmqueue_bulk(zone
, 0,
1074 pcp
->batch
, &pcp
->list
,
1076 if (unlikely(!pcp
->count
))
1080 /* Find a page of the appropriate migrate type */
1082 list_for_each_entry_reverse(page
, &pcp
->list
, lru
)
1083 if (page_private(page
) == migratetype
)
1086 list_for_each_entry(page
, &pcp
->list
, lru
)
1087 if (page_private(page
) == migratetype
)
1091 /* Allocate more to the pcp list if necessary */
1092 if (unlikely(&page
->lru
== &pcp
->list
)) {
1093 pcp
->count
+= rmqueue_bulk(zone
, 0,
1094 pcp
->batch
, &pcp
->list
,
1096 page
= list_entry(pcp
->list
.next
, struct page
, lru
);
1099 list_del(&page
->lru
);
1102 spin_lock_irqsave(&zone
->lock
, flags
);
1103 page
= __rmqueue(zone
, order
, migratetype
);
1104 spin_unlock(&zone
->lock
);
1109 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
1110 zone_statistics(preferred_zone
, zone
);
1111 local_irq_restore(flags
);
1114 VM_BUG_ON(bad_range(zone
, page
));
1115 if (prep_new_page(page
, order
, gfp_flags
))
1120 local_irq_restore(flags
);
1125 #define ALLOC_NO_WATERMARKS 0x01 /* don't check watermarks at all */
1126 #define ALLOC_WMARK_MIN 0x02 /* use pages_min watermark */
1127 #define ALLOC_WMARK_LOW 0x04 /* use pages_low watermark */
1128 #define ALLOC_WMARK_HIGH 0x08 /* use pages_high watermark */
1129 #define ALLOC_HARDER 0x10 /* try to alloc harder */
1130 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
1131 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
1133 #ifdef CONFIG_FAIL_PAGE_ALLOC
1135 static struct fail_page_alloc_attr
{
1136 struct fault_attr attr
;
1138 u32 ignore_gfp_highmem
;
1139 u32 ignore_gfp_wait
;
1142 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1144 struct dentry
*ignore_gfp_highmem_file
;
1145 struct dentry
*ignore_gfp_wait_file
;
1146 struct dentry
*min_order_file
;
1148 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1150 } fail_page_alloc
= {
1151 .attr
= FAULT_ATTR_INITIALIZER
,
1152 .ignore_gfp_wait
= 1,
1153 .ignore_gfp_highmem
= 1,
1157 static int __init
setup_fail_page_alloc(char *str
)
1159 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
1161 __setup("fail_page_alloc=", setup_fail_page_alloc
);
1163 static int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1165 if (order
< fail_page_alloc
.min_order
)
1167 if (gfp_mask
& __GFP_NOFAIL
)
1169 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
1171 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
1174 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
1177 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1179 static int __init
fail_page_alloc_debugfs(void)
1181 mode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
1185 err
= init_fault_attr_dentries(&fail_page_alloc
.attr
,
1189 dir
= fail_page_alloc
.attr
.dentries
.dir
;
1191 fail_page_alloc
.ignore_gfp_wait_file
=
1192 debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
1193 &fail_page_alloc
.ignore_gfp_wait
);
1195 fail_page_alloc
.ignore_gfp_highmem_file
=
1196 debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
1197 &fail_page_alloc
.ignore_gfp_highmem
);
1198 fail_page_alloc
.min_order_file
=
1199 debugfs_create_u32("min-order", mode
, dir
,
1200 &fail_page_alloc
.min_order
);
1202 if (!fail_page_alloc
.ignore_gfp_wait_file
||
1203 !fail_page_alloc
.ignore_gfp_highmem_file
||
1204 !fail_page_alloc
.min_order_file
) {
1206 debugfs_remove(fail_page_alloc
.ignore_gfp_wait_file
);
1207 debugfs_remove(fail_page_alloc
.ignore_gfp_highmem_file
);
1208 debugfs_remove(fail_page_alloc
.min_order_file
);
1209 cleanup_fault_attr_dentries(&fail_page_alloc
.attr
);
1215 late_initcall(fail_page_alloc_debugfs
);
1217 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1219 #else /* CONFIG_FAIL_PAGE_ALLOC */
1221 static inline int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1226 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1229 * Return 1 if free pages are above 'mark'. This takes into account the order
1230 * of the allocation.
1232 int zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1233 int classzone_idx
, int alloc_flags
)
1235 /* free_pages my go negative - that's OK */
1237 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
) - (1 << order
) + 1;
1240 if (alloc_flags
& ALLOC_HIGH
)
1242 if (alloc_flags
& ALLOC_HARDER
)
1245 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
1247 for (o
= 0; o
< order
; o
++) {
1248 /* At the next order, this order's pages become unavailable */
1249 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1251 /* Require fewer higher order pages to be free */
1254 if (free_pages
<= min
)
1262 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1263 * skip over zones that are not allowed by the cpuset, or that have
1264 * been recently (in last second) found to be nearly full. See further
1265 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1266 * that have to skip over a lot of full or unallowed zones.
1268 * If the zonelist cache is present in the passed in zonelist, then
1269 * returns a pointer to the allowed node mask (either the current
1270 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1272 * If the zonelist cache is not available for this zonelist, does
1273 * nothing and returns NULL.
1275 * If the fullzones BITMAP in the zonelist cache is stale (more than
1276 * a second since last zap'd) then we zap it out (clear its bits.)
1278 * We hold off even calling zlc_setup, until after we've checked the
1279 * first zone in the zonelist, on the theory that most allocations will
1280 * be satisfied from that first zone, so best to examine that zone as
1281 * quickly as we can.
1283 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1285 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1286 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1288 zlc
= zonelist
->zlcache_ptr
;
1292 if (time_after(jiffies
, zlc
->last_full_zap
+ HZ
)) {
1293 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1294 zlc
->last_full_zap
= jiffies
;
1297 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1298 &cpuset_current_mems_allowed
:
1299 &node_states
[N_HIGH_MEMORY
];
1300 return allowednodes
;
1304 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1305 * if it is worth looking at further for free memory:
1306 * 1) Check that the zone isn't thought to be full (doesn't have its
1307 * bit set in the zonelist_cache fullzones BITMAP).
1308 * 2) Check that the zones node (obtained from the zonelist_cache
1309 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1310 * Return true (non-zero) if zone is worth looking at further, or
1311 * else return false (zero) if it is not.
1313 * This check -ignores- the distinction between various watermarks,
1314 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1315 * found to be full for any variation of these watermarks, it will
1316 * be considered full for up to one second by all requests, unless
1317 * we are so low on memory on all allowed nodes that we are forced
1318 * into the second scan of the zonelist.
1320 * In the second scan we ignore this zonelist cache and exactly
1321 * apply the watermarks to all zones, even it is slower to do so.
1322 * We are low on memory in the second scan, and should leave no stone
1323 * unturned looking for a free page.
1325 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1326 nodemask_t
*allowednodes
)
1328 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1329 int i
; /* index of *z in zonelist zones */
1330 int n
; /* node that zone *z is on */
1332 zlc
= zonelist
->zlcache_ptr
;
1336 i
= z
- zonelist
->_zonerefs
;
1339 /* This zone is worth trying if it is allowed but not full */
1340 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1344 * Given 'z' scanning a zonelist, set the corresponding bit in
1345 * zlc->fullzones, so that subsequent attempts to allocate a page
1346 * from that zone don't waste time re-examining it.
1348 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1350 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1351 int i
; /* index of *z in zonelist zones */
1353 zlc
= zonelist
->zlcache_ptr
;
1357 i
= z
- zonelist
->_zonerefs
;
1359 set_bit(i
, zlc
->fullzones
);
1362 #else /* CONFIG_NUMA */
1364 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1369 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1370 nodemask_t
*allowednodes
)
1375 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1378 #endif /* CONFIG_NUMA */
1381 * get_page_from_freelist goes through the zonelist trying to allocate
1384 static struct page
*
1385 get_page_from_freelist(gfp_t gfp_mask
, nodemask_t
*nodemask
, unsigned int order
,
1386 struct zonelist
*zonelist
, int high_zoneidx
, int alloc_flags
)
1389 struct page
*page
= NULL
;
1391 struct zone
*zone
, *preferred_zone
;
1392 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1393 int zlc_active
= 0; /* set if using zonelist_cache */
1394 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1396 (void)first_zones_zonelist(zonelist
, high_zoneidx
, nodemask
,
1398 if (!preferred_zone
)
1401 classzone_idx
= zone_idx(preferred_zone
);
1405 * Scan zonelist, looking for a zone with enough free.
1406 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1408 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
1409 high_zoneidx
, nodemask
) {
1410 if (NUMA_BUILD
&& zlc_active
&&
1411 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1413 if ((alloc_flags
& ALLOC_CPUSET
) &&
1414 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1417 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
1419 if (alloc_flags
& ALLOC_WMARK_MIN
)
1420 mark
= zone
->pages_min
;
1421 else if (alloc_flags
& ALLOC_WMARK_LOW
)
1422 mark
= zone
->pages_low
;
1424 mark
= zone
->pages_high
;
1425 if (!zone_watermark_ok(zone
, order
, mark
,
1426 classzone_idx
, alloc_flags
)) {
1427 if (!zone_reclaim_mode
||
1428 !zone_reclaim(zone
, gfp_mask
, order
))
1429 goto this_zone_full
;
1433 page
= buffered_rmqueue(preferred_zone
, zone
, order
, gfp_mask
);
1438 zlc_mark_zone_full(zonelist
, z
);
1440 if (NUMA_BUILD
&& !did_zlc_setup
) {
1441 /* we do zlc_setup after the first zone is tried */
1442 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1448 if (unlikely(NUMA_BUILD
&& page
== NULL
&& zlc_active
)) {
1449 /* Disable zlc cache for second zonelist scan */
1457 * This is the 'heart' of the zoned buddy allocator.
1460 __alloc_pages_internal(gfp_t gfp_mask
, unsigned int order
,
1461 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
1463 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
1464 enum zone_type high_zoneidx
= gfp_zone(gfp_mask
);
1468 struct reclaim_state reclaim_state
;
1469 struct task_struct
*p
= current
;
1472 unsigned long did_some_progress
;
1473 unsigned long pages_reclaimed
= 0;
1475 might_sleep_if(wait
);
1477 if (should_fail_alloc_page(gfp_mask
, order
))
1481 z
= zonelist
->_zonerefs
; /* the list of zones suitable for gfp_mask */
1483 if (unlikely(!z
->zone
)) {
1485 * Happens if we have an empty zonelist as a result of
1486 * GFP_THISNODE being used on a memoryless node
1491 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
, order
,
1492 zonelist
, high_zoneidx
, ALLOC_WMARK_LOW
|ALLOC_CPUSET
);
1497 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
1498 * __GFP_NOWARN set) should not cause reclaim since the subsystem
1499 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
1500 * using a larger set of nodes after it has established that the
1501 * allowed per node queues are empty and that nodes are
1504 if (NUMA_BUILD
&& (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
1507 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
)
1508 wakeup_kswapd(zone
, order
);
1511 * OK, we're below the kswapd watermark and have kicked background
1512 * reclaim. Now things get more complex, so set up alloc_flags according
1513 * to how we want to proceed.
1515 * The caller may dip into page reserves a bit more if the caller
1516 * cannot run direct reclaim, or if the caller has realtime scheduling
1517 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
1518 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1520 alloc_flags
= ALLOC_WMARK_MIN
;
1521 if ((unlikely(rt_task(p
)) && !in_interrupt()) || !wait
)
1522 alloc_flags
|= ALLOC_HARDER
;
1523 if (gfp_mask
& __GFP_HIGH
)
1524 alloc_flags
|= ALLOC_HIGH
;
1526 alloc_flags
|= ALLOC_CPUSET
;
1529 * Go through the zonelist again. Let __GFP_HIGH and allocations
1530 * coming from realtime tasks go deeper into reserves.
1532 * This is the last chance, in general, before the goto nopage.
1533 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1534 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1536 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
, zonelist
,
1537 high_zoneidx
, alloc_flags
);
1541 /* This allocation should allow future memory freeing. */
1544 if (((p
->flags
& PF_MEMALLOC
) || unlikely(test_thread_flag(TIF_MEMDIE
)))
1545 && !in_interrupt()) {
1546 if (!(gfp_mask
& __GFP_NOMEMALLOC
)) {
1548 /* go through the zonelist yet again, ignoring mins */
1549 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
1550 zonelist
, high_zoneidx
, ALLOC_NO_WATERMARKS
);
1553 if (gfp_mask
& __GFP_NOFAIL
) {
1554 congestion_wait(WRITE
, HZ
/50);
1561 /* Atomic allocations - we can't balance anything */
1567 /* We now go into synchronous reclaim */
1568 cpuset_memory_pressure_bump();
1569 p
->flags
|= PF_MEMALLOC
;
1570 reclaim_state
.reclaimed_slab
= 0;
1571 p
->reclaim_state
= &reclaim_state
;
1573 did_some_progress
= try_to_free_pages(zonelist
, order
, gfp_mask
);
1575 p
->reclaim_state
= NULL
;
1576 p
->flags
&= ~PF_MEMALLOC
;
1583 if (likely(did_some_progress
)) {
1584 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
1585 zonelist
, high_zoneidx
, alloc_flags
);
1588 } else if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
1589 if (!try_set_zone_oom(zonelist
, gfp_mask
)) {
1590 schedule_timeout_uninterruptible(1);
1595 * Go through the zonelist yet one more time, keep
1596 * very high watermark here, this is only to catch
1597 * a parallel oom killing, we must fail if we're still
1598 * under heavy pressure.
1600 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
,
1601 order
, zonelist
, high_zoneidx
,
1602 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
);
1604 clear_zonelist_oom(zonelist
, gfp_mask
);
1608 /* The OOM killer will not help higher order allocs so fail */
1609 if (order
> PAGE_ALLOC_COSTLY_ORDER
) {
1610 clear_zonelist_oom(zonelist
, gfp_mask
);
1614 out_of_memory(zonelist
, gfp_mask
, order
);
1615 clear_zonelist_oom(zonelist
, gfp_mask
);
1620 * Don't let big-order allocations loop unless the caller explicitly
1621 * requests that. Wait for some write requests to complete then retry.
1623 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
1624 * means __GFP_NOFAIL, but that may not be true in other
1627 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
1628 * specified, then we retry until we no longer reclaim any pages
1629 * (above), or we've reclaimed an order of pages at least as
1630 * large as the allocation's order. In both cases, if the
1631 * allocation still fails, we stop retrying.
1633 pages_reclaimed
+= did_some_progress
;
1635 if (!(gfp_mask
& __GFP_NORETRY
)) {
1636 if (order
<= PAGE_ALLOC_COSTLY_ORDER
) {
1639 if (gfp_mask
& __GFP_REPEAT
&&
1640 pages_reclaimed
< (1 << order
))
1643 if (gfp_mask
& __GFP_NOFAIL
)
1647 congestion_wait(WRITE
, HZ
/50);
1652 if (!(gfp_mask
& __GFP_NOWARN
) && printk_ratelimit()) {
1653 printk(KERN_WARNING
"%s: page allocation failure."
1654 " order:%d, mode:0x%x\n",
1655 p
->comm
, order
, gfp_mask
);
1662 EXPORT_SYMBOL(__alloc_pages_internal
);
1665 * Common helper functions.
1667 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
1670 page
= alloc_pages(gfp_mask
, order
);
1673 return (unsigned long) page_address(page
);
1676 EXPORT_SYMBOL(__get_free_pages
);
1678 unsigned long get_zeroed_page(gfp_t gfp_mask
)
1683 * get_zeroed_page() returns a 32-bit address, which cannot represent
1686 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
1688 page
= alloc_pages(gfp_mask
| __GFP_ZERO
, 0);
1690 return (unsigned long) page_address(page
);
1694 EXPORT_SYMBOL(get_zeroed_page
);
1696 void __pagevec_free(struct pagevec
*pvec
)
1698 int i
= pagevec_count(pvec
);
1701 free_hot_cold_page(pvec
->pages
[i
], pvec
->cold
);
1704 void __free_pages(struct page
*page
, unsigned int order
)
1706 if (put_page_testzero(page
)) {
1708 free_hot_page(page
);
1710 __free_pages_ok(page
, order
);
1714 EXPORT_SYMBOL(__free_pages
);
1716 void free_pages(unsigned long addr
, unsigned int order
)
1719 VM_BUG_ON(!virt_addr_valid((void *)addr
));
1720 __free_pages(virt_to_page((void *)addr
), order
);
1724 EXPORT_SYMBOL(free_pages
);
1727 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
1728 * @size: the number of bytes to allocate
1729 * @gfp_mask: GFP flags for the allocation
1731 * This function is similar to alloc_pages(), except that it allocates the
1732 * minimum number of pages to satisfy the request. alloc_pages() can only
1733 * allocate memory in power-of-two pages.
1735 * This function is also limited by MAX_ORDER.
1737 * Memory allocated by this function must be released by free_pages_exact().
1739 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
1741 unsigned int order
= get_order(size
);
1744 addr
= __get_free_pages(gfp_mask
, order
);
1746 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
1747 unsigned long used
= addr
+ PAGE_ALIGN(size
);
1749 split_page(virt_to_page(addr
), order
);
1750 while (used
< alloc_end
) {
1756 return (void *)addr
;
1758 EXPORT_SYMBOL(alloc_pages_exact
);
1761 * free_pages_exact - release memory allocated via alloc_pages_exact()
1762 * @virt: the value returned by alloc_pages_exact.
1763 * @size: size of allocation, same value as passed to alloc_pages_exact().
1765 * Release the memory allocated by a previous call to alloc_pages_exact.
1767 void free_pages_exact(void *virt
, size_t size
)
1769 unsigned long addr
= (unsigned long)virt
;
1770 unsigned long end
= addr
+ PAGE_ALIGN(size
);
1772 while (addr
< end
) {
1777 EXPORT_SYMBOL(free_pages_exact
);
1779 static unsigned int nr_free_zone_pages(int offset
)
1784 /* Just pick one node, since fallback list is circular */
1785 unsigned int sum
= 0;
1787 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
1789 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
1790 unsigned long size
= zone
->present_pages
;
1791 unsigned long high
= zone
->pages_high
;
1800 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
1802 unsigned int nr_free_buffer_pages(void)
1804 return nr_free_zone_pages(gfp_zone(GFP_USER
));
1806 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
1809 * Amount of free RAM allocatable within all zones
1811 unsigned int nr_free_pagecache_pages(void)
1813 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
1816 static inline void show_node(struct zone
*zone
)
1819 printk("Node %d ", zone_to_nid(zone
));
1822 void si_meminfo(struct sysinfo
*val
)
1824 val
->totalram
= totalram_pages
;
1826 val
->freeram
= global_page_state(NR_FREE_PAGES
);
1827 val
->bufferram
= nr_blockdev_pages();
1828 val
->totalhigh
= totalhigh_pages
;
1829 val
->freehigh
= nr_free_highpages();
1830 val
->mem_unit
= PAGE_SIZE
;
1833 EXPORT_SYMBOL(si_meminfo
);
1836 void si_meminfo_node(struct sysinfo
*val
, int nid
)
1838 pg_data_t
*pgdat
= NODE_DATA(nid
);
1840 val
->totalram
= pgdat
->node_present_pages
;
1841 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
1842 #ifdef CONFIG_HIGHMEM
1843 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
1844 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
1850 val
->mem_unit
= PAGE_SIZE
;
1854 #define K(x) ((x) << (PAGE_SHIFT-10))
1857 * Show free area list (used inside shift_scroll-lock stuff)
1858 * We also calculate the percentage fragmentation. We do this by counting the
1859 * memory on each free list with the exception of the first item on the list.
1861 void show_free_areas(void)
1866 for_each_zone(zone
) {
1867 if (!populated_zone(zone
))
1871 printk("%s per-cpu:\n", zone
->name
);
1873 for_each_online_cpu(cpu
) {
1874 struct per_cpu_pageset
*pageset
;
1876 pageset
= zone_pcp(zone
, cpu
);
1878 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
1879 cpu
, pageset
->pcp
.high
,
1880 pageset
->pcp
.batch
, pageset
->pcp
.count
);
1884 printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu unstable:%lu\n"
1885 " free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n",
1886 global_page_state(NR_ACTIVE
),
1887 global_page_state(NR_INACTIVE
),
1888 global_page_state(NR_FILE_DIRTY
),
1889 global_page_state(NR_WRITEBACK
),
1890 global_page_state(NR_UNSTABLE_NFS
),
1891 global_page_state(NR_FREE_PAGES
),
1892 global_page_state(NR_SLAB_RECLAIMABLE
) +
1893 global_page_state(NR_SLAB_UNRECLAIMABLE
),
1894 global_page_state(NR_FILE_MAPPED
),
1895 global_page_state(NR_PAGETABLE
),
1896 global_page_state(NR_BOUNCE
));
1898 for_each_zone(zone
) {
1901 if (!populated_zone(zone
))
1913 " pages_scanned:%lu"
1914 " all_unreclaimable? %s"
1917 K(zone_page_state(zone
, NR_FREE_PAGES
)),
1920 K(zone
->pages_high
),
1921 K(zone_page_state(zone
, NR_ACTIVE
)),
1922 K(zone_page_state(zone
, NR_INACTIVE
)),
1923 K(zone
->present_pages
),
1924 zone
->pages_scanned
,
1925 (zone_is_all_unreclaimable(zone
) ? "yes" : "no")
1927 printk("lowmem_reserve[]:");
1928 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
1929 printk(" %lu", zone
->lowmem_reserve
[i
]);
1933 for_each_zone(zone
) {
1934 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
1936 if (!populated_zone(zone
))
1940 printk("%s: ", zone
->name
);
1942 spin_lock_irqsave(&zone
->lock
, flags
);
1943 for (order
= 0; order
< MAX_ORDER
; order
++) {
1944 nr
[order
] = zone
->free_area
[order
].nr_free
;
1945 total
+= nr
[order
] << order
;
1947 spin_unlock_irqrestore(&zone
->lock
, flags
);
1948 for (order
= 0; order
< MAX_ORDER
; order
++)
1949 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
1950 printk("= %lukB\n", K(total
));
1953 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
1955 show_swap_cache_info();
1958 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
1960 zoneref
->zone
= zone
;
1961 zoneref
->zone_idx
= zone_idx(zone
);
1965 * Builds allocation fallback zone lists.
1967 * Add all populated zones of a node to the zonelist.
1969 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
1970 int nr_zones
, enum zone_type zone_type
)
1974 BUG_ON(zone_type
>= MAX_NR_ZONES
);
1979 zone
= pgdat
->node_zones
+ zone_type
;
1980 if (populated_zone(zone
)) {
1981 zoneref_set_zone(zone
,
1982 &zonelist
->_zonerefs
[nr_zones
++]);
1983 check_highest_zone(zone_type
);
1986 } while (zone_type
);
1993 * 0 = automatic detection of better ordering.
1994 * 1 = order by ([node] distance, -zonetype)
1995 * 2 = order by (-zonetype, [node] distance)
1997 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
1998 * the same zonelist. So only NUMA can configure this param.
2000 #define ZONELIST_ORDER_DEFAULT 0
2001 #define ZONELIST_ORDER_NODE 1
2002 #define ZONELIST_ORDER_ZONE 2
2004 /* zonelist order in the kernel.
2005 * set_zonelist_order() will set this to NODE or ZONE.
2007 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2008 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
2012 /* The value user specified ....changed by config */
2013 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2014 /* string for sysctl */
2015 #define NUMA_ZONELIST_ORDER_LEN 16
2016 char numa_zonelist_order
[16] = "default";
2019 * interface for configure zonelist ordering.
2020 * command line option "numa_zonelist_order"
2021 * = "[dD]efault - default, automatic configuration.
2022 * = "[nN]ode - order by node locality, then by zone within node
2023 * = "[zZ]one - order by zone, then by locality within zone
2026 static int __parse_numa_zonelist_order(char *s
)
2028 if (*s
== 'd' || *s
== 'D') {
2029 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2030 } else if (*s
== 'n' || *s
== 'N') {
2031 user_zonelist_order
= ZONELIST_ORDER_NODE
;
2032 } else if (*s
== 'z' || *s
== 'Z') {
2033 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
2036 "Ignoring invalid numa_zonelist_order value: "
2043 static __init
int setup_numa_zonelist_order(char *s
)
2046 return __parse_numa_zonelist_order(s
);
2049 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
2052 * sysctl handler for numa_zonelist_order
2054 int numa_zonelist_order_handler(ctl_table
*table
, int write
,
2055 struct file
*file
, void __user
*buffer
, size_t *length
,
2058 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
2062 strncpy(saved_string
, (char*)table
->data
,
2063 NUMA_ZONELIST_ORDER_LEN
);
2064 ret
= proc_dostring(table
, write
, file
, buffer
, length
, ppos
);
2068 int oldval
= user_zonelist_order
;
2069 if (__parse_numa_zonelist_order((char*)table
->data
)) {
2071 * bogus value. restore saved string
2073 strncpy((char*)table
->data
, saved_string
,
2074 NUMA_ZONELIST_ORDER_LEN
);
2075 user_zonelist_order
= oldval
;
2076 } else if (oldval
!= user_zonelist_order
)
2077 build_all_zonelists();
2083 #define MAX_NODE_LOAD (num_online_nodes())
2084 static int node_load
[MAX_NUMNODES
];
2087 * find_next_best_node - find the next node that should appear in a given node's fallback list
2088 * @node: node whose fallback list we're appending
2089 * @used_node_mask: nodemask_t of already used nodes
2091 * We use a number of factors to determine which is the next node that should
2092 * appear on a given node's fallback list. The node should not have appeared
2093 * already in @node's fallback list, and it should be the next closest node
2094 * according to the distance array (which contains arbitrary distance values
2095 * from each node to each node in the system), and should also prefer nodes
2096 * with no CPUs, since presumably they'll have very little allocation pressure
2097 * on them otherwise.
2098 * It returns -1 if no node is found.
2100 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
2103 int min_val
= INT_MAX
;
2105 node_to_cpumask_ptr(tmp
, 0);
2107 /* Use the local node if we haven't already */
2108 if (!node_isset(node
, *used_node_mask
)) {
2109 node_set(node
, *used_node_mask
);
2113 for_each_node_state(n
, N_HIGH_MEMORY
) {
2115 /* Don't want a node to appear more than once */
2116 if (node_isset(n
, *used_node_mask
))
2119 /* Use the distance array to find the distance */
2120 val
= node_distance(node
, n
);
2122 /* Penalize nodes under us ("prefer the next node") */
2125 /* Give preference to headless and unused nodes */
2126 node_to_cpumask_ptr_next(tmp
, n
);
2127 if (!cpus_empty(*tmp
))
2128 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
2130 /* Slight preference for less loaded node */
2131 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
2132 val
+= node_load
[n
];
2134 if (val
< min_val
) {
2141 node_set(best_node
, *used_node_mask
);
2148 * Build zonelists ordered by node and zones within node.
2149 * This results in maximum locality--normal zone overflows into local
2150 * DMA zone, if any--but risks exhausting DMA zone.
2152 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
2155 struct zonelist
*zonelist
;
2157 zonelist
= &pgdat
->node_zonelists
[0];
2158 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
2160 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2162 zonelist
->_zonerefs
[j
].zone
= NULL
;
2163 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2167 * Build gfp_thisnode zonelists
2169 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
2172 struct zonelist
*zonelist
;
2174 zonelist
= &pgdat
->node_zonelists
[1];
2175 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
2176 zonelist
->_zonerefs
[j
].zone
= NULL
;
2177 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2181 * Build zonelists ordered by zone and nodes within zones.
2182 * This results in conserving DMA zone[s] until all Normal memory is
2183 * exhausted, but results in overflowing to remote node while memory
2184 * may still exist in local DMA zone.
2186 static int node_order
[MAX_NUMNODES
];
2188 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
2191 int zone_type
; /* needs to be signed */
2193 struct zonelist
*zonelist
;
2195 zonelist
= &pgdat
->node_zonelists
[0];
2197 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
2198 for (j
= 0; j
< nr_nodes
; j
++) {
2199 node
= node_order
[j
];
2200 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
2201 if (populated_zone(z
)) {
2203 &zonelist
->_zonerefs
[pos
++]);
2204 check_highest_zone(zone_type
);
2208 zonelist
->_zonerefs
[pos
].zone
= NULL
;
2209 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
2212 static int default_zonelist_order(void)
2215 unsigned long low_kmem_size
,total_size
;
2219 * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem.
2220 * If they are really small and used heavily, the system can fall
2221 * into OOM very easily.
2222 * This function detect ZONE_DMA/DMA32 size and confgigures zone order.
2224 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
2227 for_each_online_node(nid
) {
2228 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2229 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2230 if (populated_zone(z
)) {
2231 if (zone_type
< ZONE_NORMAL
)
2232 low_kmem_size
+= z
->present_pages
;
2233 total_size
+= z
->present_pages
;
2237 if (!low_kmem_size
|| /* there are no DMA area. */
2238 low_kmem_size
> total_size
/2) /* DMA/DMA32 is big. */
2239 return ZONELIST_ORDER_NODE
;
2241 * look into each node's config.
2242 * If there is a node whose DMA/DMA32 memory is very big area on
2243 * local memory, NODE_ORDER may be suitable.
2245 average_size
= total_size
/
2246 (nodes_weight(node_states
[N_HIGH_MEMORY
]) + 1);
2247 for_each_online_node(nid
) {
2250 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2251 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2252 if (populated_zone(z
)) {
2253 if (zone_type
< ZONE_NORMAL
)
2254 low_kmem_size
+= z
->present_pages
;
2255 total_size
+= z
->present_pages
;
2258 if (low_kmem_size
&&
2259 total_size
> average_size
&& /* ignore small node */
2260 low_kmem_size
> total_size
* 70/100)
2261 return ZONELIST_ORDER_NODE
;
2263 return ZONELIST_ORDER_ZONE
;
2266 static void set_zonelist_order(void)
2268 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
2269 current_zonelist_order
= default_zonelist_order();
2271 current_zonelist_order
= user_zonelist_order
;
2274 static void build_zonelists(pg_data_t
*pgdat
)
2278 nodemask_t used_mask
;
2279 int local_node
, prev_node
;
2280 struct zonelist
*zonelist
;
2281 int order
= current_zonelist_order
;
2283 /* initialize zonelists */
2284 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
2285 zonelist
= pgdat
->node_zonelists
+ i
;
2286 zonelist
->_zonerefs
[0].zone
= NULL
;
2287 zonelist
->_zonerefs
[0].zone_idx
= 0;
2290 /* NUMA-aware ordering of nodes */
2291 local_node
= pgdat
->node_id
;
2292 load
= num_online_nodes();
2293 prev_node
= local_node
;
2294 nodes_clear(used_mask
);
2296 memset(node_load
, 0, sizeof(node_load
));
2297 memset(node_order
, 0, sizeof(node_order
));
2300 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
2301 int distance
= node_distance(local_node
, node
);
2304 * If another node is sufficiently far away then it is better
2305 * to reclaim pages in a zone before going off node.
2307 if (distance
> RECLAIM_DISTANCE
)
2308 zone_reclaim_mode
= 1;
2311 * We don't want to pressure a particular node.
2312 * So adding penalty to the first node in same
2313 * distance group to make it round-robin.
2315 if (distance
!= node_distance(local_node
, prev_node
))
2316 node_load
[node
] = load
;
2320 if (order
== ZONELIST_ORDER_NODE
)
2321 build_zonelists_in_node_order(pgdat
, node
);
2323 node_order
[j
++] = node
; /* remember order */
2326 if (order
== ZONELIST_ORDER_ZONE
) {
2327 /* calculate node order -- i.e., DMA last! */
2328 build_zonelists_in_zone_order(pgdat
, j
);
2331 build_thisnode_zonelists(pgdat
);
2334 /* Construct the zonelist performance cache - see further mmzone.h */
2335 static void build_zonelist_cache(pg_data_t
*pgdat
)
2337 struct zonelist
*zonelist
;
2338 struct zonelist_cache
*zlc
;
2341 zonelist
= &pgdat
->node_zonelists
[0];
2342 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
2343 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
2344 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
2345 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
2349 #else /* CONFIG_NUMA */
2351 static void set_zonelist_order(void)
2353 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
2356 static void build_zonelists(pg_data_t
*pgdat
)
2358 int node
, local_node
;
2360 struct zonelist
*zonelist
;
2362 local_node
= pgdat
->node_id
;
2364 zonelist
= &pgdat
->node_zonelists
[0];
2365 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
2368 * Now we build the zonelist so that it contains the zones
2369 * of all the other nodes.
2370 * We don't want to pressure a particular node, so when
2371 * building the zones for node N, we make sure that the
2372 * zones coming right after the local ones are those from
2373 * node N+1 (modulo N)
2375 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
2376 if (!node_online(node
))
2378 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2381 for (node
= 0; node
< local_node
; node
++) {
2382 if (!node_online(node
))
2384 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2388 zonelist
->_zonerefs
[j
].zone
= NULL
;
2389 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2392 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2393 static void build_zonelist_cache(pg_data_t
*pgdat
)
2395 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
2398 #endif /* CONFIG_NUMA */
2400 /* return values int ....just for stop_machine() */
2401 static int __build_all_zonelists(void *dummy
)
2405 for_each_online_node(nid
) {
2406 pg_data_t
*pgdat
= NODE_DATA(nid
);
2408 build_zonelists(pgdat
);
2409 build_zonelist_cache(pgdat
);
2414 void build_all_zonelists(void)
2416 set_zonelist_order();
2418 if (system_state
== SYSTEM_BOOTING
) {
2419 __build_all_zonelists(NULL
);
2420 mminit_verify_zonelist();
2421 cpuset_init_current_mems_allowed();
2423 /* we have to stop all cpus to guarantee there is no user
2425 stop_machine(__build_all_zonelists
, NULL
, NULL
);
2426 /* cpuset refresh routine should be here */
2428 vm_total_pages
= nr_free_pagecache_pages();
2430 * Disable grouping by mobility if the number of pages in the
2431 * system is too low to allow the mechanism to work. It would be
2432 * more accurate, but expensive to check per-zone. This check is
2433 * made on memory-hotadd so a system can start with mobility
2434 * disabled and enable it later
2436 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
2437 page_group_by_mobility_disabled
= 1;
2439 page_group_by_mobility_disabled
= 0;
2441 printk("Built %i zonelists in %s order, mobility grouping %s. "
2442 "Total pages: %ld\n",
2444 zonelist_order_name
[current_zonelist_order
],
2445 page_group_by_mobility_disabled
? "off" : "on",
2448 printk("Policy zone: %s\n", zone_names
[policy_zone
]);
2453 * Helper functions to size the waitqueue hash table.
2454 * Essentially these want to choose hash table sizes sufficiently
2455 * large so that collisions trying to wait on pages are rare.
2456 * But in fact, the number of active page waitqueues on typical
2457 * systems is ridiculously low, less than 200. So this is even
2458 * conservative, even though it seems large.
2460 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
2461 * waitqueues, i.e. the size of the waitq table given the number of pages.
2463 #define PAGES_PER_WAITQUEUE 256
2465 #ifndef CONFIG_MEMORY_HOTPLUG
2466 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
2468 unsigned long size
= 1;
2470 pages
/= PAGES_PER_WAITQUEUE
;
2472 while (size
< pages
)
2476 * Once we have dozens or even hundreds of threads sleeping
2477 * on IO we've got bigger problems than wait queue collision.
2478 * Limit the size of the wait table to a reasonable size.
2480 size
= min(size
, 4096UL);
2482 return max(size
, 4UL);
2486 * A zone's size might be changed by hot-add, so it is not possible to determine
2487 * a suitable size for its wait_table. So we use the maximum size now.
2489 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
2491 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
2492 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
2493 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
2495 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
2496 * or more by the traditional way. (See above). It equals:
2498 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
2499 * ia64(16K page size) : = ( 8G + 4M)byte.
2500 * powerpc (64K page size) : = (32G +16M)byte.
2502 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
2509 * This is an integer logarithm so that shifts can be used later
2510 * to extract the more random high bits from the multiplicative
2511 * hash function before the remainder is taken.
2513 static inline unsigned long wait_table_bits(unsigned long size
)
2518 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
2521 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2522 * of blocks reserved is based on zone->pages_min. The memory within the
2523 * reserve will tend to store contiguous free pages. Setting min_free_kbytes
2524 * higher will lead to a bigger reserve which will get freed as contiguous
2525 * blocks as reclaim kicks in
2527 static void setup_zone_migrate_reserve(struct zone
*zone
)
2529 unsigned long start_pfn
, pfn
, end_pfn
;
2531 unsigned long reserve
, block_migratetype
;
2533 /* Get the start pfn, end pfn and the number of blocks to reserve */
2534 start_pfn
= zone
->zone_start_pfn
;
2535 end_pfn
= start_pfn
+ zone
->spanned_pages
;
2536 reserve
= roundup(zone
->pages_min
, pageblock_nr_pages
) >>
2539 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
2540 if (!pfn_valid(pfn
))
2542 page
= pfn_to_page(pfn
);
2544 /* Watch out for overlapping nodes */
2545 if (page_to_nid(page
) != zone_to_nid(zone
))
2548 /* Blocks with reserved pages will never free, skip them. */
2549 if (PageReserved(page
))
2552 block_migratetype
= get_pageblock_migratetype(page
);
2554 /* If this block is reserved, account for it */
2555 if (reserve
> 0 && block_migratetype
== MIGRATE_RESERVE
) {
2560 /* Suitable for reserving if this block is movable */
2561 if (reserve
> 0 && block_migratetype
== MIGRATE_MOVABLE
) {
2562 set_pageblock_migratetype(page
, MIGRATE_RESERVE
);
2563 move_freepages_block(zone
, page
, MIGRATE_RESERVE
);
2569 * If the reserve is met and this is a previous reserved block,
2572 if (block_migratetype
== MIGRATE_RESERVE
) {
2573 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
2574 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
2580 * Initially all pages are reserved - free ones are freed
2581 * up by free_all_bootmem() once the early boot process is
2582 * done. Non-atomic initialization, single-pass.
2584 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
2585 unsigned long start_pfn
, enum memmap_context context
)
2588 unsigned long end_pfn
= start_pfn
+ size
;
2592 z
= &NODE_DATA(nid
)->node_zones
[zone
];
2593 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
2595 * There can be holes in boot-time mem_map[]s
2596 * handed to this function. They do not
2597 * exist on hotplugged memory.
2599 if (context
== MEMMAP_EARLY
) {
2600 if (!early_pfn_valid(pfn
))
2602 if (!early_pfn_in_nid(pfn
, nid
))
2605 page
= pfn_to_page(pfn
);
2606 set_page_links(page
, zone
, nid
, pfn
);
2607 mminit_verify_page_links(page
, zone
, nid
, pfn
);
2608 init_page_count(page
);
2609 reset_page_mapcount(page
);
2610 SetPageReserved(page
);
2612 * Mark the block movable so that blocks are reserved for
2613 * movable at startup. This will force kernel allocations
2614 * to reserve their blocks rather than leaking throughout
2615 * the address space during boot when many long-lived
2616 * kernel allocations are made. Later some blocks near
2617 * the start are marked MIGRATE_RESERVE by
2618 * setup_zone_migrate_reserve()
2620 * bitmap is created for zone's valid pfn range. but memmap
2621 * can be created for invalid pages (for alignment)
2622 * check here not to call set_pageblock_migratetype() against
2625 if ((z
->zone_start_pfn
<= pfn
)
2626 && (pfn
< z
->zone_start_pfn
+ z
->spanned_pages
)
2627 && !(pfn
& (pageblock_nr_pages
- 1)))
2628 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
2630 INIT_LIST_HEAD(&page
->lru
);
2631 #ifdef WANT_PAGE_VIRTUAL
2632 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
2633 if (!is_highmem_idx(zone
))
2634 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
2639 static void __meminit
zone_init_free_lists(struct zone
*zone
)
2642 for_each_migratetype_order(order
, t
) {
2643 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
2644 zone
->free_area
[order
].nr_free
= 0;
2648 #ifndef __HAVE_ARCH_MEMMAP_INIT
2649 #define memmap_init(size, nid, zone, start_pfn) \
2650 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
2653 static int zone_batchsize(struct zone
*zone
)
2658 * The per-cpu-pages pools are set to around 1000th of the
2659 * size of the zone. But no more than 1/2 of a meg.
2661 * OK, so we don't know how big the cache is. So guess.
2663 batch
= zone
->present_pages
/ 1024;
2664 if (batch
* PAGE_SIZE
> 512 * 1024)
2665 batch
= (512 * 1024) / PAGE_SIZE
;
2666 batch
/= 4; /* We effectively *= 4 below */
2671 * Clamp the batch to a 2^n - 1 value. Having a power
2672 * of 2 value was found to be more likely to have
2673 * suboptimal cache aliasing properties in some cases.
2675 * For example if 2 tasks are alternately allocating
2676 * batches of pages, one task can end up with a lot
2677 * of pages of one half of the possible page colors
2678 * and the other with pages of the other colors.
2680 batch
= (1 << (fls(batch
+ batch
/2)-1)) - 1;
2685 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
2687 struct per_cpu_pages
*pcp
;
2689 memset(p
, 0, sizeof(*p
));
2693 pcp
->high
= 6 * batch
;
2694 pcp
->batch
= max(1UL, 1 * batch
);
2695 INIT_LIST_HEAD(&pcp
->list
);
2699 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
2700 * to the value high for the pageset p.
2703 static void setup_pagelist_highmark(struct per_cpu_pageset
*p
,
2706 struct per_cpu_pages
*pcp
;
2710 pcp
->batch
= max(1UL, high
/4);
2711 if ((high
/4) > (PAGE_SHIFT
* 8))
2712 pcp
->batch
= PAGE_SHIFT
* 8;
2718 * Boot pageset table. One per cpu which is going to be used for all
2719 * zones and all nodes. The parameters will be set in such a way
2720 * that an item put on a list will immediately be handed over to
2721 * the buddy list. This is safe since pageset manipulation is done
2722 * with interrupts disabled.
2724 * Some NUMA counter updates may also be caught by the boot pagesets.
2726 * The boot_pagesets must be kept even after bootup is complete for
2727 * unused processors and/or zones. They do play a role for bootstrapping
2728 * hotplugged processors.
2730 * zoneinfo_show() and maybe other functions do
2731 * not check if the processor is online before following the pageset pointer.
2732 * Other parts of the kernel may not check if the zone is available.
2734 static struct per_cpu_pageset boot_pageset
[NR_CPUS
];
2737 * Dynamically allocate memory for the
2738 * per cpu pageset array in struct zone.
2740 static int __cpuinit
process_zones(int cpu
)
2742 struct zone
*zone
, *dzone
;
2743 int node
= cpu_to_node(cpu
);
2745 node_set_state(node
, N_CPU
); /* this node has a cpu */
2747 for_each_zone(zone
) {
2749 if (!populated_zone(zone
))
2752 zone_pcp(zone
, cpu
) = kmalloc_node(sizeof(struct per_cpu_pageset
),
2754 if (!zone_pcp(zone
, cpu
))
2757 setup_pageset(zone_pcp(zone
, cpu
), zone_batchsize(zone
));
2759 if (percpu_pagelist_fraction
)
2760 setup_pagelist_highmark(zone_pcp(zone
, cpu
),
2761 (zone
->present_pages
/ percpu_pagelist_fraction
));
2766 for_each_zone(dzone
) {
2767 if (!populated_zone(dzone
))
2771 kfree(zone_pcp(dzone
, cpu
));
2772 zone_pcp(dzone
, cpu
) = &boot_pageset
[cpu
];
2777 static inline void free_zone_pagesets(int cpu
)
2781 for_each_zone(zone
) {
2782 struct per_cpu_pageset
*pset
= zone_pcp(zone
, cpu
);
2784 /* Free per_cpu_pageset if it is slab allocated */
2785 if (pset
!= &boot_pageset
[cpu
])
2787 zone_pcp(zone
, cpu
) = &boot_pageset
[cpu
];
2791 static int __cpuinit
pageset_cpuup_callback(struct notifier_block
*nfb
,
2792 unsigned long action
,
2795 int cpu
= (long)hcpu
;
2796 int ret
= NOTIFY_OK
;
2799 case CPU_UP_PREPARE
:
2800 case CPU_UP_PREPARE_FROZEN
:
2801 if (process_zones(cpu
))
2804 case CPU_UP_CANCELED
:
2805 case CPU_UP_CANCELED_FROZEN
:
2807 case CPU_DEAD_FROZEN
:
2808 free_zone_pagesets(cpu
);
2816 static struct notifier_block __cpuinitdata pageset_notifier
=
2817 { &pageset_cpuup_callback
, NULL
, 0 };
2819 void __init
setup_per_cpu_pageset(void)
2823 /* Initialize per_cpu_pageset for cpu 0.
2824 * A cpuup callback will do this for every cpu
2825 * as it comes online
2827 err
= process_zones(smp_processor_id());
2829 register_cpu_notifier(&pageset_notifier
);
2834 static noinline __init_refok
2835 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
2838 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
2842 * The per-page waitqueue mechanism uses hashed waitqueues
2845 zone
->wait_table_hash_nr_entries
=
2846 wait_table_hash_nr_entries(zone_size_pages
);
2847 zone
->wait_table_bits
=
2848 wait_table_bits(zone
->wait_table_hash_nr_entries
);
2849 alloc_size
= zone
->wait_table_hash_nr_entries
2850 * sizeof(wait_queue_head_t
);
2852 if (!slab_is_available()) {
2853 zone
->wait_table
= (wait_queue_head_t
*)
2854 alloc_bootmem_node(pgdat
, alloc_size
);
2857 * This case means that a zone whose size was 0 gets new memory
2858 * via memory hot-add.
2859 * But it may be the case that a new node was hot-added. In
2860 * this case vmalloc() will not be able to use this new node's
2861 * memory - this wait_table must be initialized to use this new
2862 * node itself as well.
2863 * To use this new node's memory, further consideration will be
2866 zone
->wait_table
= vmalloc(alloc_size
);
2868 if (!zone
->wait_table
)
2871 for(i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
2872 init_waitqueue_head(zone
->wait_table
+ i
);
2877 static __meminit
void zone_pcp_init(struct zone
*zone
)
2880 unsigned long batch
= zone_batchsize(zone
);
2882 for (cpu
= 0; cpu
< NR_CPUS
; cpu
++) {
2884 /* Early boot. Slab allocator not functional yet */
2885 zone_pcp(zone
, cpu
) = &boot_pageset
[cpu
];
2886 setup_pageset(&boot_pageset
[cpu
],0);
2888 setup_pageset(zone_pcp(zone
,cpu
), batch
);
2891 if (zone
->present_pages
)
2892 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%lu\n",
2893 zone
->name
, zone
->present_pages
, batch
);
2896 __meminit
int init_currently_empty_zone(struct zone
*zone
,
2897 unsigned long zone_start_pfn
,
2899 enum memmap_context context
)
2901 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
2903 ret
= zone_wait_table_init(zone
, size
);
2906 pgdat
->nr_zones
= zone_idx(zone
) + 1;
2908 zone
->zone_start_pfn
= zone_start_pfn
;
2910 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
2911 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
2913 (unsigned long)zone_idx(zone
),
2914 zone_start_pfn
, (zone_start_pfn
+ size
));
2916 zone_init_free_lists(zone
);
2921 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
2923 * Basic iterator support. Return the first range of PFNs for a node
2924 * Note: nid == MAX_NUMNODES returns first region regardless of node
2926 static int __meminit
first_active_region_index_in_nid(int nid
)
2930 for (i
= 0; i
< nr_nodemap_entries
; i
++)
2931 if (nid
== MAX_NUMNODES
|| early_node_map
[i
].nid
== nid
)
2938 * Basic iterator support. Return the next active range of PFNs for a node
2939 * Note: nid == MAX_NUMNODES returns next region regardless of node
2941 static int __meminit
next_active_region_index_in_nid(int index
, int nid
)
2943 for (index
= index
+ 1; index
< nr_nodemap_entries
; index
++)
2944 if (nid
== MAX_NUMNODES
|| early_node_map
[index
].nid
== nid
)
2950 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
2952 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
2953 * Architectures may implement their own version but if add_active_range()
2954 * was used and there are no special requirements, this is a convenient
2957 int __meminit
__early_pfn_to_nid(unsigned long pfn
)
2961 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
2962 unsigned long start_pfn
= early_node_map
[i
].start_pfn
;
2963 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
2965 if (start_pfn
<= pfn
&& pfn
< end_pfn
)
2966 return early_node_map
[i
].nid
;
2968 /* This is a memory hole */
2971 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
2973 int __meminit
early_pfn_to_nid(unsigned long pfn
)
2977 nid
= __early_pfn_to_nid(pfn
);
2980 /* just returns 0 */
2984 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
2985 bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
2989 nid
= __early_pfn_to_nid(pfn
);
2990 if (nid
>= 0 && nid
!= node
)
2996 /* Basic iterator support to walk early_node_map[] */
2997 #define for_each_active_range_index_in_nid(i, nid) \
2998 for (i = first_active_region_index_in_nid(nid); i != -1; \
2999 i = next_active_region_index_in_nid(i, nid))
3002 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
3003 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
3004 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
3006 * If an architecture guarantees that all ranges registered with
3007 * add_active_ranges() contain no holes and may be freed, this
3008 * this function may be used instead of calling free_bootmem() manually.
3010 void __init
free_bootmem_with_active_regions(int nid
,
3011 unsigned long max_low_pfn
)
3015 for_each_active_range_index_in_nid(i
, nid
) {
3016 unsigned long size_pages
= 0;
3017 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
3019 if (early_node_map
[i
].start_pfn
>= max_low_pfn
)
3022 if (end_pfn
> max_low_pfn
)
3023 end_pfn
= max_low_pfn
;
3025 size_pages
= end_pfn
- early_node_map
[i
].start_pfn
;
3026 free_bootmem_node(NODE_DATA(early_node_map
[i
].nid
),
3027 PFN_PHYS(early_node_map
[i
].start_pfn
),
3028 size_pages
<< PAGE_SHIFT
);
3032 void __init
work_with_active_regions(int nid
, work_fn_t work_fn
, void *data
)
3037 for_each_active_range_index_in_nid(i
, nid
) {
3038 ret
= work_fn(early_node_map
[i
].start_pfn
,
3039 early_node_map
[i
].end_pfn
, data
);
3045 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3046 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3048 * If an architecture guarantees that all ranges registered with
3049 * add_active_ranges() contain no holes and may be freed, this
3050 * function may be used instead of calling memory_present() manually.
3052 void __init
sparse_memory_present_with_active_regions(int nid
)
3056 for_each_active_range_index_in_nid(i
, nid
)
3057 memory_present(early_node_map
[i
].nid
,
3058 early_node_map
[i
].start_pfn
,
3059 early_node_map
[i
].end_pfn
);
3063 * push_node_boundaries - Push node boundaries to at least the requested boundary
3064 * @nid: The nid of the node to push the boundary for
3065 * @start_pfn: The start pfn of the node
3066 * @end_pfn: The end pfn of the node
3068 * In reserve-based hot-add, mem_map is allocated that is unused until hotadd
3069 * time. Specifically, on x86_64, SRAT will report ranges that can potentially
3070 * be hotplugged even though no physical memory exists. This function allows
3071 * an arch to push out the node boundaries so mem_map is allocated that can
3074 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
3075 void __init
push_node_boundaries(unsigned int nid
,
3076 unsigned long start_pfn
, unsigned long end_pfn
)
3078 mminit_dprintk(MMINIT_TRACE
, "zoneboundary",
3079 "Entering push_node_boundaries(%u, %lu, %lu)\n",
3080 nid
, start_pfn
, end_pfn
);
3082 /* Initialise the boundary for this node if necessary */
3083 if (node_boundary_end_pfn
[nid
] == 0)
3084 node_boundary_start_pfn
[nid
] = -1UL;
3086 /* Update the boundaries */
3087 if (node_boundary_start_pfn
[nid
] > start_pfn
)
3088 node_boundary_start_pfn
[nid
] = start_pfn
;
3089 if (node_boundary_end_pfn
[nid
] < end_pfn
)
3090 node_boundary_end_pfn
[nid
] = end_pfn
;
3093 /* If necessary, push the node boundary out for reserve hotadd */
3094 static void __meminit
account_node_boundary(unsigned int nid
,
3095 unsigned long *start_pfn
, unsigned long *end_pfn
)
3097 mminit_dprintk(MMINIT_TRACE
, "zoneboundary",
3098 "Entering account_node_boundary(%u, %lu, %lu)\n",
3099 nid
, *start_pfn
, *end_pfn
);
3101 /* Return if boundary information has not been provided */
3102 if (node_boundary_end_pfn
[nid
] == 0)
3105 /* Check the boundaries and update if necessary */
3106 if (node_boundary_start_pfn
[nid
] < *start_pfn
)
3107 *start_pfn
= node_boundary_start_pfn
[nid
];
3108 if (node_boundary_end_pfn
[nid
] > *end_pfn
)
3109 *end_pfn
= node_boundary_end_pfn
[nid
];
3112 void __init
push_node_boundaries(unsigned int nid
,
3113 unsigned long start_pfn
, unsigned long end_pfn
) {}
3115 static void __meminit
account_node_boundary(unsigned int nid
,
3116 unsigned long *start_pfn
, unsigned long *end_pfn
) {}
3121 * get_pfn_range_for_nid - Return the start and end page frames for a node
3122 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
3123 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
3124 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
3126 * It returns the start and end page frame of a node based on information
3127 * provided by an arch calling add_active_range(). If called for a node
3128 * with no available memory, a warning is printed and the start and end
3131 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
3132 unsigned long *start_pfn
, unsigned long *end_pfn
)
3138 for_each_active_range_index_in_nid(i
, nid
) {
3139 *start_pfn
= min(*start_pfn
, early_node_map
[i
].start_pfn
);
3140 *end_pfn
= max(*end_pfn
, early_node_map
[i
].end_pfn
);
3143 if (*start_pfn
== -1UL)
3146 /* Push the node boundaries out if requested */
3147 account_node_boundary(nid
, start_pfn
, end_pfn
);
3151 * This finds a zone that can be used for ZONE_MOVABLE pages. The
3152 * assumption is made that zones within a node are ordered in monotonic
3153 * increasing memory addresses so that the "highest" populated zone is used
3155 static void __init
find_usable_zone_for_movable(void)
3158 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
3159 if (zone_index
== ZONE_MOVABLE
)
3162 if (arch_zone_highest_possible_pfn
[zone_index
] >
3163 arch_zone_lowest_possible_pfn
[zone_index
])
3167 VM_BUG_ON(zone_index
== -1);
3168 movable_zone
= zone_index
;
3172 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
3173 * because it is sized independant of architecture. Unlike the other zones,
3174 * the starting point for ZONE_MOVABLE is not fixed. It may be different
3175 * in each node depending on the size of each node and how evenly kernelcore
3176 * is distributed. This helper function adjusts the zone ranges
3177 * provided by the architecture for a given node by using the end of the
3178 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
3179 * zones within a node are in order of monotonic increases memory addresses
3181 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
3182 unsigned long zone_type
,
3183 unsigned long node_start_pfn
,
3184 unsigned long node_end_pfn
,
3185 unsigned long *zone_start_pfn
,
3186 unsigned long *zone_end_pfn
)
3188 /* Only adjust if ZONE_MOVABLE is on this node */
3189 if (zone_movable_pfn
[nid
]) {
3190 /* Size ZONE_MOVABLE */
3191 if (zone_type
== ZONE_MOVABLE
) {
3192 *zone_start_pfn
= zone_movable_pfn
[nid
];
3193 *zone_end_pfn
= min(node_end_pfn
,
3194 arch_zone_highest_possible_pfn
[movable_zone
]);
3196 /* Adjust for ZONE_MOVABLE starting within this range */
3197 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
3198 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
3199 *zone_end_pfn
= zone_movable_pfn
[nid
];
3201 /* Check if this whole range is within ZONE_MOVABLE */
3202 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
3203 *zone_start_pfn
= *zone_end_pfn
;
3208 * Return the number of pages a zone spans in a node, including holes
3209 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
3211 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3212 unsigned long zone_type
,
3213 unsigned long *ignored
)
3215 unsigned long node_start_pfn
, node_end_pfn
;
3216 unsigned long zone_start_pfn
, zone_end_pfn
;
3218 /* Get the start and end of the node and zone */
3219 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3220 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
3221 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
3222 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3223 node_start_pfn
, node_end_pfn
,
3224 &zone_start_pfn
, &zone_end_pfn
);
3226 /* Check that this node has pages within the zone's required range */
3227 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
3230 /* Move the zone boundaries inside the node if necessary */
3231 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
3232 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
3234 /* Return the spanned pages */
3235 return zone_end_pfn
- zone_start_pfn
;
3239 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
3240 * then all holes in the requested range will be accounted for.
3242 static unsigned long __meminit
__absent_pages_in_range(int nid
,
3243 unsigned long range_start_pfn
,
3244 unsigned long range_end_pfn
)
3247 unsigned long prev_end_pfn
= 0, hole_pages
= 0;
3248 unsigned long start_pfn
;
3250 /* Find the end_pfn of the first active range of pfns in the node */
3251 i
= first_active_region_index_in_nid(nid
);
3255 prev_end_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3257 /* Account for ranges before physical memory on this node */
3258 if (early_node_map
[i
].start_pfn
> range_start_pfn
)
3259 hole_pages
= prev_end_pfn
- range_start_pfn
;
3261 /* Find all holes for the zone within the node */
3262 for (; i
!= -1; i
= next_active_region_index_in_nid(i
, nid
)) {
3264 /* No need to continue if prev_end_pfn is outside the zone */
3265 if (prev_end_pfn
>= range_end_pfn
)
3268 /* Make sure the end of the zone is not within the hole */
3269 start_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3270 prev_end_pfn
= max(prev_end_pfn
, range_start_pfn
);
3272 /* Update the hole size cound and move on */
3273 if (start_pfn
> range_start_pfn
) {
3274 BUG_ON(prev_end_pfn
> start_pfn
);
3275 hole_pages
+= start_pfn
- prev_end_pfn
;
3277 prev_end_pfn
= early_node_map
[i
].end_pfn
;
3280 /* Account for ranges past physical memory on this node */
3281 if (range_end_pfn
> prev_end_pfn
)
3282 hole_pages
+= range_end_pfn
-
3283 max(range_start_pfn
, prev_end_pfn
);
3289 * absent_pages_in_range - Return number of page frames in holes within a range
3290 * @start_pfn: The start PFN to start searching for holes
3291 * @end_pfn: The end PFN to stop searching for holes
3293 * It returns the number of pages frames in memory holes within a range.
3295 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
3296 unsigned long end_pfn
)
3298 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
3301 /* Return the number of page frames in holes in a zone on a node */
3302 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
3303 unsigned long zone_type
,
3304 unsigned long *ignored
)
3306 unsigned long node_start_pfn
, node_end_pfn
;
3307 unsigned long zone_start_pfn
, zone_end_pfn
;
3309 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3310 zone_start_pfn
= max(arch_zone_lowest_possible_pfn
[zone_type
],
3312 zone_end_pfn
= min(arch_zone_highest_possible_pfn
[zone_type
],
3315 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3316 node_start_pfn
, node_end_pfn
,
3317 &zone_start_pfn
, &zone_end_pfn
);
3318 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
3322 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3323 unsigned long zone_type
,
3324 unsigned long *zones_size
)
3326 return zones_size
[zone_type
];
3329 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
3330 unsigned long zone_type
,
3331 unsigned long *zholes_size
)
3336 return zholes_size
[zone_type
];
3341 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
3342 unsigned long *zones_size
, unsigned long *zholes_size
)
3344 unsigned long realtotalpages
, totalpages
= 0;
3347 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3348 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
3350 pgdat
->node_spanned_pages
= totalpages
;
3352 realtotalpages
= totalpages
;
3353 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3355 zone_absent_pages_in_node(pgdat
->node_id
, i
,
3357 pgdat
->node_present_pages
= realtotalpages
;
3358 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
3362 #ifndef CONFIG_SPARSEMEM
3364 * Calculate the size of the zone->blockflags rounded to an unsigned long
3365 * Start by making sure zonesize is a multiple of pageblock_order by rounding
3366 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
3367 * round what is now in bits to nearest long in bits, then return it in
3370 static unsigned long __init
usemap_size(unsigned long zonesize
)
3372 unsigned long usemapsize
;
3374 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
3375 usemapsize
= usemapsize
>> pageblock_order
;
3376 usemapsize
*= NR_PAGEBLOCK_BITS
;
3377 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
3379 return usemapsize
/ 8;
3382 static void __init
setup_usemap(struct pglist_data
*pgdat
,
3383 struct zone
*zone
, unsigned long zonesize
)
3385 unsigned long usemapsize
= usemap_size(zonesize
);
3386 zone
->pageblock_flags
= NULL
;
3388 zone
->pageblock_flags
= alloc_bootmem_node(pgdat
, usemapsize
);
3389 memset(zone
->pageblock_flags
, 0, usemapsize
);
3393 static void inline setup_usemap(struct pglist_data
*pgdat
,
3394 struct zone
*zone
, unsigned long zonesize
) {}
3395 #endif /* CONFIG_SPARSEMEM */
3397 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3399 /* Return a sensible default order for the pageblock size. */
3400 static inline int pageblock_default_order(void)
3402 if (HPAGE_SHIFT
> PAGE_SHIFT
)
3403 return HUGETLB_PAGE_ORDER
;
3408 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
3409 static inline void __init
set_pageblock_order(unsigned int order
)
3411 /* Check that pageblock_nr_pages has not already been setup */
3412 if (pageblock_order
)
3416 * Assume the largest contiguous order of interest is a huge page.
3417 * This value may be variable depending on boot parameters on IA64
3419 pageblock_order
= order
;
3421 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3424 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
3425 * and pageblock_default_order() are unused as pageblock_order is set
3426 * at compile-time. See include/linux/pageblock-flags.h for the values of
3427 * pageblock_order based on the kernel config
3429 static inline int pageblock_default_order(unsigned int order
)
3433 #define set_pageblock_order(x) do {} while (0)
3435 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3438 * Set up the zone data structures:
3439 * - mark all pages reserved
3440 * - mark all memory queues empty
3441 * - clear the memory bitmaps
3443 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
,
3444 unsigned long *zones_size
, unsigned long *zholes_size
)
3447 int nid
= pgdat
->node_id
;
3448 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
3451 pgdat_resize_init(pgdat
);
3452 pgdat
->nr_zones
= 0;
3453 init_waitqueue_head(&pgdat
->kswapd_wait
);
3454 pgdat
->kswapd_max_order
= 0;
3456 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
3457 struct zone
*zone
= pgdat
->node_zones
+ j
;
3458 unsigned long size
, realsize
, memmap_pages
;
3460 size
= zone_spanned_pages_in_node(nid
, j
, zones_size
);
3461 realsize
= size
- zone_absent_pages_in_node(nid
, j
,
3465 * Adjust realsize so that it accounts for how much memory
3466 * is used by this zone for memmap. This affects the watermark
3467 * and per-cpu initialisations
3470 PAGE_ALIGN(size
* sizeof(struct page
)) >> PAGE_SHIFT
;
3471 if (realsize
>= memmap_pages
) {
3472 realsize
-= memmap_pages
;
3473 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
3474 "%s zone: %lu pages used for memmap\n",
3475 zone_names
[j
], memmap_pages
);
3478 " %s zone: %lu pages exceeds realsize %lu\n",
3479 zone_names
[j
], memmap_pages
, realsize
);
3481 /* Account for reserved pages */
3482 if (j
== 0 && realsize
> dma_reserve
) {
3483 realsize
-= dma_reserve
;
3484 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
3485 "%s zone: %lu pages reserved\n",
3486 zone_names
[0], dma_reserve
);
3489 if (!is_highmem_idx(j
))
3490 nr_kernel_pages
+= realsize
;
3491 nr_all_pages
+= realsize
;
3493 zone
->spanned_pages
= size
;
3494 zone
->present_pages
= realsize
;
3497 zone
->min_unmapped_pages
= (realsize
*sysctl_min_unmapped_ratio
)
3499 zone
->min_slab_pages
= (realsize
* sysctl_min_slab_ratio
) / 100;
3501 zone
->name
= zone_names
[j
];
3502 spin_lock_init(&zone
->lock
);
3503 spin_lock_init(&zone
->lru_lock
);
3504 zone_seqlock_init(zone
);
3505 zone
->zone_pgdat
= pgdat
;
3507 zone
->prev_priority
= DEF_PRIORITY
;
3509 zone_pcp_init(zone
);
3510 INIT_LIST_HEAD(&zone
->active_list
);
3511 INIT_LIST_HEAD(&zone
->inactive_list
);
3512 zone
->nr_scan_active
= 0;
3513 zone
->nr_scan_inactive
= 0;
3514 zap_zone_vm_stats(zone
);
3519 set_pageblock_order(pageblock_default_order());
3520 setup_usemap(pgdat
, zone
, size
);
3521 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
3522 size
, MEMMAP_EARLY
);
3524 memmap_init(size
, nid
, j
, zone_start_pfn
);
3525 zone_start_pfn
+= size
;
3529 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
3531 /* Skip empty nodes */
3532 if (!pgdat
->node_spanned_pages
)
3535 #ifdef CONFIG_FLAT_NODE_MEM_MAP
3536 /* ia64 gets its own node_mem_map, before this, without bootmem */
3537 if (!pgdat
->node_mem_map
) {
3538 unsigned long size
, start
, end
;
3542 * The zone's endpoints aren't required to be MAX_ORDER
3543 * aligned but the node_mem_map endpoints must be in order
3544 * for the buddy allocator to function correctly.
3546 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
3547 end
= pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
3548 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
3549 size
= (end
- start
) * sizeof(struct page
);
3550 map
= alloc_remap(pgdat
->node_id
, size
);
3552 map
= alloc_bootmem_node(pgdat
, size
);
3553 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
3555 #ifndef CONFIG_NEED_MULTIPLE_NODES
3557 * With no DISCONTIG, the global mem_map is just set as node 0's
3559 if (pgdat
== NODE_DATA(0)) {
3560 mem_map
= NODE_DATA(0)->node_mem_map
;
3561 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3562 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
3563 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
3564 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
3567 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
3570 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
3571 unsigned long node_start_pfn
, unsigned long *zholes_size
)
3573 pg_data_t
*pgdat
= NODE_DATA(nid
);
3575 pgdat
->node_id
= nid
;
3576 pgdat
->node_start_pfn
= node_start_pfn
;
3577 calculate_node_totalpages(pgdat
, zones_size
, zholes_size
);
3579 alloc_node_mem_map(pgdat
);
3580 #ifdef CONFIG_FLAT_NODE_MEM_MAP
3581 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
3582 nid
, (unsigned long)pgdat
,
3583 (unsigned long)pgdat
->node_mem_map
);
3586 free_area_init_core(pgdat
, zones_size
, zholes_size
);
3589 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3591 #if MAX_NUMNODES > 1
3593 * Figure out the number of possible node ids.
3595 static void __init
setup_nr_node_ids(void)
3598 unsigned int highest
= 0;
3600 for_each_node_mask(node
, node_possible_map
)
3602 nr_node_ids
= highest
+ 1;
3605 static inline void setup_nr_node_ids(void)
3611 * add_active_range - Register a range of PFNs backed by physical memory
3612 * @nid: The node ID the range resides on
3613 * @start_pfn: The start PFN of the available physical memory
3614 * @end_pfn: The end PFN of the available physical memory
3616 * These ranges are stored in an early_node_map[] and later used by
3617 * free_area_init_nodes() to calculate zone sizes and holes. If the
3618 * range spans a memory hole, it is up to the architecture to ensure
3619 * the memory is not freed by the bootmem allocator. If possible
3620 * the range being registered will be merged with existing ranges.
3622 void __init
add_active_range(unsigned int nid
, unsigned long start_pfn
,
3623 unsigned long end_pfn
)
3627 mminit_dprintk(MMINIT_TRACE
, "memory_register",
3628 "Entering add_active_range(%d, %#lx, %#lx) "
3629 "%d entries of %d used\n",
3630 nid
, start_pfn
, end_pfn
,
3631 nr_nodemap_entries
, MAX_ACTIVE_REGIONS
);
3633 mminit_validate_memmodel_limits(&start_pfn
, &end_pfn
);
3635 /* Merge with existing active regions if possible */
3636 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
3637 if (early_node_map
[i
].nid
!= nid
)
3640 /* Skip if an existing region covers this new one */
3641 if (start_pfn
>= early_node_map
[i
].start_pfn
&&
3642 end_pfn
<= early_node_map
[i
].end_pfn
)
3645 /* Merge forward if suitable */
3646 if (start_pfn
<= early_node_map
[i
].end_pfn
&&
3647 end_pfn
> early_node_map
[i
].end_pfn
) {
3648 early_node_map
[i
].end_pfn
= end_pfn
;
3652 /* Merge backward if suitable */
3653 if (start_pfn
< early_node_map
[i
].end_pfn
&&
3654 end_pfn
>= early_node_map
[i
].start_pfn
) {
3655 early_node_map
[i
].start_pfn
= start_pfn
;
3660 /* Check that early_node_map is large enough */
3661 if (i
>= MAX_ACTIVE_REGIONS
) {
3662 printk(KERN_CRIT
"More than %d memory regions, truncating\n",
3663 MAX_ACTIVE_REGIONS
);
3667 early_node_map
[i
].nid
= nid
;
3668 early_node_map
[i
].start_pfn
= start_pfn
;
3669 early_node_map
[i
].end_pfn
= end_pfn
;
3670 nr_nodemap_entries
= i
+ 1;
3674 * remove_active_range - Shrink an existing registered range of PFNs
3675 * @nid: The node id the range is on that should be shrunk
3676 * @start_pfn: The new PFN of the range
3677 * @end_pfn: The new PFN of the range
3679 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
3680 * The map is kept near the end physical page range that has already been
3681 * registered. This function allows an arch to shrink an existing registered
3684 void __init
remove_active_range(unsigned int nid
, unsigned long start_pfn
,
3685 unsigned long end_pfn
)
3690 printk(KERN_DEBUG
"remove_active_range (%d, %lu, %lu)\n",
3691 nid
, start_pfn
, end_pfn
);
3693 /* Find the old active region end and shrink */
3694 for_each_active_range_index_in_nid(i
, nid
) {
3695 if (early_node_map
[i
].start_pfn
>= start_pfn
&&
3696 early_node_map
[i
].end_pfn
<= end_pfn
) {
3698 early_node_map
[i
].start_pfn
= 0;
3699 early_node_map
[i
].end_pfn
= 0;
3703 if (early_node_map
[i
].start_pfn
< start_pfn
&&
3704 early_node_map
[i
].end_pfn
> start_pfn
) {
3705 unsigned long temp_end_pfn
= early_node_map
[i
].end_pfn
;
3706 early_node_map
[i
].end_pfn
= start_pfn
;
3707 if (temp_end_pfn
> end_pfn
)
3708 add_active_range(nid
, end_pfn
, temp_end_pfn
);
3711 if (early_node_map
[i
].start_pfn
>= start_pfn
&&
3712 early_node_map
[i
].end_pfn
> end_pfn
&&
3713 early_node_map
[i
].start_pfn
< end_pfn
) {
3714 early_node_map
[i
].start_pfn
= end_pfn
;
3722 /* remove the blank ones */
3723 for (i
= nr_nodemap_entries
- 1; i
> 0; i
--) {
3724 if (early_node_map
[i
].nid
!= nid
)
3726 if (early_node_map
[i
].end_pfn
)
3728 /* we found it, get rid of it */
3729 for (j
= i
; j
< nr_nodemap_entries
- 1; j
++)
3730 memcpy(&early_node_map
[j
], &early_node_map
[j
+1],
3731 sizeof(early_node_map
[j
]));
3732 j
= nr_nodemap_entries
- 1;
3733 memset(&early_node_map
[j
], 0, sizeof(early_node_map
[j
]));
3734 nr_nodemap_entries
--;
3739 * remove_all_active_ranges - Remove all currently registered regions
3741 * During discovery, it may be found that a table like SRAT is invalid
3742 * and an alternative discovery method must be used. This function removes
3743 * all currently registered regions.
3745 void __init
remove_all_active_ranges(void)
3747 memset(early_node_map
, 0, sizeof(early_node_map
));
3748 nr_nodemap_entries
= 0;
3749 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
3750 memset(node_boundary_start_pfn
, 0, sizeof(node_boundary_start_pfn
));
3751 memset(node_boundary_end_pfn
, 0, sizeof(node_boundary_end_pfn
));
3752 #endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
3755 /* Compare two active node_active_regions */
3756 static int __init
cmp_node_active_region(const void *a
, const void *b
)
3758 struct node_active_region
*arange
= (struct node_active_region
*)a
;
3759 struct node_active_region
*brange
= (struct node_active_region
*)b
;
3761 /* Done this way to avoid overflows */
3762 if (arange
->start_pfn
> brange
->start_pfn
)
3764 if (arange
->start_pfn
< brange
->start_pfn
)
3770 /* sort the node_map by start_pfn */
3771 static void __init
sort_node_map(void)
3773 sort(early_node_map
, (size_t)nr_nodemap_entries
,
3774 sizeof(struct node_active_region
),
3775 cmp_node_active_region
, NULL
);
3778 /* Find the lowest pfn for a node */
3779 static unsigned long __init
find_min_pfn_for_node(int nid
)
3782 unsigned long min_pfn
= ULONG_MAX
;
3784 /* Assuming a sorted map, the first range found has the starting pfn */
3785 for_each_active_range_index_in_nid(i
, nid
)
3786 min_pfn
= min(min_pfn
, early_node_map
[i
].start_pfn
);
3788 if (min_pfn
== ULONG_MAX
) {
3790 "Could not find start_pfn for node %d\n", nid
);
3798 * find_min_pfn_with_active_regions - Find the minimum PFN registered
3800 * It returns the minimum PFN based on information provided via
3801 * add_active_range().
3803 unsigned long __init
find_min_pfn_with_active_regions(void)
3805 return find_min_pfn_for_node(MAX_NUMNODES
);
3809 * early_calculate_totalpages()
3810 * Sum pages in active regions for movable zone.
3811 * Populate N_HIGH_MEMORY for calculating usable_nodes.
3813 static unsigned long __init
early_calculate_totalpages(void)
3816 unsigned long totalpages
= 0;
3818 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
3819 unsigned long pages
= early_node_map
[i
].end_pfn
-
3820 early_node_map
[i
].start_pfn
;
3821 totalpages
+= pages
;
3823 node_set_state(early_node_map
[i
].nid
, N_HIGH_MEMORY
);
3829 * Find the PFN the Movable zone begins in each node. Kernel memory
3830 * is spread evenly between nodes as long as the nodes have enough
3831 * memory. When they don't, some nodes will have more kernelcore than
3834 static void __init
find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn
)
3837 unsigned long usable_startpfn
;
3838 unsigned long kernelcore_node
, kernelcore_remaining
;
3839 unsigned long totalpages
= early_calculate_totalpages();
3840 int usable_nodes
= nodes_weight(node_states
[N_HIGH_MEMORY
]);
3843 * If movablecore was specified, calculate what size of
3844 * kernelcore that corresponds so that memory usable for
3845 * any allocation type is evenly spread. If both kernelcore
3846 * and movablecore are specified, then the value of kernelcore
3847 * will be used for required_kernelcore if it's greater than
3848 * what movablecore would have allowed.
3850 if (required_movablecore
) {
3851 unsigned long corepages
;
3854 * Round-up so that ZONE_MOVABLE is at least as large as what
3855 * was requested by the user
3857 required_movablecore
=
3858 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
3859 corepages
= totalpages
- required_movablecore
;
3861 required_kernelcore
= max(required_kernelcore
, corepages
);
3864 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
3865 if (!required_kernelcore
)
3868 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
3869 find_usable_zone_for_movable();
3870 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
3873 /* Spread kernelcore memory as evenly as possible throughout nodes */
3874 kernelcore_node
= required_kernelcore
/ usable_nodes
;
3875 for_each_node_state(nid
, N_HIGH_MEMORY
) {
3877 * Recalculate kernelcore_node if the division per node
3878 * now exceeds what is necessary to satisfy the requested
3879 * amount of memory for the kernel
3881 if (required_kernelcore
< kernelcore_node
)
3882 kernelcore_node
= required_kernelcore
/ usable_nodes
;
3885 * As the map is walked, we track how much memory is usable
3886 * by the kernel using kernelcore_remaining. When it is
3887 * 0, the rest of the node is usable by ZONE_MOVABLE
3889 kernelcore_remaining
= kernelcore_node
;
3891 /* Go through each range of PFNs within this node */
3892 for_each_active_range_index_in_nid(i
, nid
) {
3893 unsigned long start_pfn
, end_pfn
;
3894 unsigned long size_pages
;
3896 start_pfn
= max(early_node_map
[i
].start_pfn
,
3897 zone_movable_pfn
[nid
]);
3898 end_pfn
= early_node_map
[i
].end_pfn
;
3899 if (start_pfn
>= end_pfn
)
3902 /* Account for what is only usable for kernelcore */
3903 if (start_pfn
< usable_startpfn
) {
3904 unsigned long kernel_pages
;
3905 kernel_pages
= min(end_pfn
, usable_startpfn
)
3908 kernelcore_remaining
-= min(kernel_pages
,
3909 kernelcore_remaining
);
3910 required_kernelcore
-= min(kernel_pages
,
3911 required_kernelcore
);
3913 /* Continue if range is now fully accounted */
3914 if (end_pfn
<= usable_startpfn
) {
3917 * Push zone_movable_pfn to the end so
3918 * that if we have to rebalance
3919 * kernelcore across nodes, we will
3920 * not double account here
3922 zone_movable_pfn
[nid
] = end_pfn
;
3925 start_pfn
= usable_startpfn
;
3929 * The usable PFN range for ZONE_MOVABLE is from
3930 * start_pfn->end_pfn. Calculate size_pages as the
3931 * number of pages used as kernelcore
3933 size_pages
= end_pfn
- start_pfn
;
3934 if (size_pages
> kernelcore_remaining
)
3935 size_pages
= kernelcore_remaining
;
3936 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
3939 * Some kernelcore has been met, update counts and
3940 * break if the kernelcore for this node has been
3943 required_kernelcore
-= min(required_kernelcore
,
3945 kernelcore_remaining
-= size_pages
;
3946 if (!kernelcore_remaining
)
3952 * If there is still required_kernelcore, we do another pass with one
3953 * less node in the count. This will push zone_movable_pfn[nid] further
3954 * along on the nodes that still have memory until kernelcore is
3958 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
3961 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
3962 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
3963 zone_movable_pfn
[nid
] =
3964 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
3967 /* Any regular memory on that node ? */
3968 static void check_for_regular_memory(pg_data_t
*pgdat
)
3970 #ifdef CONFIG_HIGHMEM
3971 enum zone_type zone_type
;
3973 for (zone_type
= 0; zone_type
<= ZONE_NORMAL
; zone_type
++) {
3974 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
3975 if (zone
->present_pages
)
3976 node_set_state(zone_to_nid(zone
), N_NORMAL_MEMORY
);
3982 * free_area_init_nodes - Initialise all pg_data_t and zone data
3983 * @max_zone_pfn: an array of max PFNs for each zone
3985 * This will call free_area_init_node() for each active node in the system.
3986 * Using the page ranges provided by add_active_range(), the size of each
3987 * zone in each node and their holes is calculated. If the maximum PFN
3988 * between two adjacent zones match, it is assumed that the zone is empty.
3989 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
3990 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
3991 * starts where the previous one ended. For example, ZONE_DMA32 starts
3992 * at arch_max_dma_pfn.
3994 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
3999 /* Sort early_node_map as initialisation assumes it is sorted */
4002 /* Record where the zone boundaries are */
4003 memset(arch_zone_lowest_possible_pfn
, 0,
4004 sizeof(arch_zone_lowest_possible_pfn
));
4005 memset(arch_zone_highest_possible_pfn
, 0,
4006 sizeof(arch_zone_highest_possible_pfn
));
4007 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
4008 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
4009 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
4010 if (i
== ZONE_MOVABLE
)
4012 arch_zone_lowest_possible_pfn
[i
] =
4013 arch_zone_highest_possible_pfn
[i
-1];
4014 arch_zone_highest_possible_pfn
[i
] =
4015 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
4017 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
4018 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
4020 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
4021 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
4022 find_zone_movable_pfns_for_nodes(zone_movable_pfn
);
4024 /* Print out the zone ranges */
4025 printk("Zone PFN ranges:\n");
4026 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4027 if (i
== ZONE_MOVABLE
)
4029 printk(" %-8s %0#10lx -> %0#10lx\n",
4031 arch_zone_lowest_possible_pfn
[i
],
4032 arch_zone_highest_possible_pfn
[i
]);
4035 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
4036 printk("Movable zone start PFN for each node\n");
4037 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
4038 if (zone_movable_pfn
[i
])
4039 printk(" Node %d: %lu\n", i
, zone_movable_pfn
[i
]);
4042 /* Print out the early_node_map[] */
4043 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries
);
4044 for (i
= 0; i
< nr_nodemap_entries
; i
++)
4045 printk(" %3d: %0#10lx -> %0#10lx\n", early_node_map
[i
].nid
,
4046 early_node_map
[i
].start_pfn
,
4047 early_node_map
[i
].end_pfn
);
4049 /* Initialise every node */
4050 mminit_verify_pageflags_layout();
4051 setup_nr_node_ids();
4052 for_each_online_node(nid
) {
4053 pg_data_t
*pgdat
= NODE_DATA(nid
);
4054 free_area_init_node(nid
, NULL
,
4055 find_min_pfn_for_node(nid
), NULL
);
4057 /* Any memory on that node */
4058 if (pgdat
->node_present_pages
)
4059 node_set_state(nid
, N_HIGH_MEMORY
);
4060 check_for_regular_memory(pgdat
);
4064 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
4066 unsigned long long coremem
;
4070 coremem
= memparse(p
, &p
);
4071 *core
= coremem
>> PAGE_SHIFT
;
4073 /* Paranoid check that UL is enough for the coremem value */
4074 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
4080 * kernelcore=size sets the amount of memory for use for allocations that
4081 * cannot be reclaimed or migrated.
4083 static int __init
cmdline_parse_kernelcore(char *p
)
4085 return cmdline_parse_core(p
, &required_kernelcore
);
4089 * movablecore=size sets the amount of memory for use for allocations that
4090 * can be reclaimed or migrated.
4092 static int __init
cmdline_parse_movablecore(char *p
)
4094 return cmdline_parse_core(p
, &required_movablecore
);
4097 early_param("kernelcore", cmdline_parse_kernelcore
);
4098 early_param("movablecore", cmdline_parse_movablecore
);
4100 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
4103 * set_dma_reserve - set the specified number of pages reserved in the first zone
4104 * @new_dma_reserve: The number of pages to mark reserved
4106 * The per-cpu batchsize and zone watermarks are determined by present_pages.
4107 * In the DMA zone, a significant percentage may be consumed by kernel image
4108 * and other unfreeable allocations which can skew the watermarks badly. This
4109 * function may optionally be used to account for unfreeable pages in the
4110 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
4111 * smaller per-cpu batchsize.
4113 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
4115 dma_reserve
= new_dma_reserve
;
4118 #ifndef CONFIG_NEED_MULTIPLE_NODES
4119 struct pglist_data __refdata contig_page_data
= { .bdata
= &bootmem_node_data
[0] };
4120 EXPORT_SYMBOL(contig_page_data
);
4123 void __init
free_area_init(unsigned long *zones_size
)
4125 free_area_init_node(0, zones_size
,
4126 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
4129 static int page_alloc_cpu_notify(struct notifier_block
*self
,
4130 unsigned long action
, void *hcpu
)
4132 int cpu
= (unsigned long)hcpu
;
4134 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
4138 * Spill the event counters of the dead processor
4139 * into the current processors event counters.
4140 * This artificially elevates the count of the current
4143 vm_events_fold_cpu(cpu
);
4146 * Zero the differential counters of the dead processor
4147 * so that the vm statistics are consistent.
4149 * This is only okay since the processor is dead and cannot
4150 * race with what we are doing.
4152 refresh_cpu_vm_stats(cpu
);
4157 void __init
page_alloc_init(void)
4159 hotcpu_notifier(page_alloc_cpu_notify
, 0);
4163 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
4164 * or min_free_kbytes changes.
4166 static void calculate_totalreserve_pages(void)
4168 struct pglist_data
*pgdat
;
4169 unsigned long reserve_pages
= 0;
4170 enum zone_type i
, j
;
4172 for_each_online_pgdat(pgdat
) {
4173 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4174 struct zone
*zone
= pgdat
->node_zones
+ i
;
4175 unsigned long max
= 0;
4177 /* Find valid and maximum lowmem_reserve in the zone */
4178 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
4179 if (zone
->lowmem_reserve
[j
] > max
)
4180 max
= zone
->lowmem_reserve
[j
];
4183 /* we treat pages_high as reserved pages. */
4184 max
+= zone
->pages_high
;
4186 if (max
> zone
->present_pages
)
4187 max
= zone
->present_pages
;
4188 reserve_pages
+= max
;
4191 totalreserve_pages
= reserve_pages
;
4195 * setup_per_zone_lowmem_reserve - called whenever
4196 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
4197 * has a correct pages reserved value, so an adequate number of
4198 * pages are left in the zone after a successful __alloc_pages().
4200 static void setup_per_zone_lowmem_reserve(void)
4202 struct pglist_data
*pgdat
;
4203 enum zone_type j
, idx
;
4205 for_each_online_pgdat(pgdat
) {
4206 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4207 struct zone
*zone
= pgdat
->node_zones
+ j
;
4208 unsigned long present_pages
= zone
->present_pages
;
4210 zone
->lowmem_reserve
[j
] = 0;
4214 struct zone
*lower_zone
;
4218 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
4219 sysctl_lowmem_reserve_ratio
[idx
] = 1;
4221 lower_zone
= pgdat
->node_zones
+ idx
;
4222 lower_zone
->lowmem_reserve
[j
] = present_pages
/
4223 sysctl_lowmem_reserve_ratio
[idx
];
4224 present_pages
+= lower_zone
->present_pages
;
4229 /* update totalreserve_pages */
4230 calculate_totalreserve_pages();
4234 * setup_per_zone_pages_min - called when min_free_kbytes changes.
4236 * Ensures that the pages_{min,low,high} values for each zone are set correctly
4237 * with respect to min_free_kbytes.
4239 void setup_per_zone_pages_min(void)
4241 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
4242 unsigned long lowmem_pages
= 0;
4244 unsigned long flags
;
4246 /* Calculate total number of !ZONE_HIGHMEM pages */
4247 for_each_zone(zone
) {
4248 if (!is_highmem(zone
))
4249 lowmem_pages
+= zone
->present_pages
;
4252 for_each_zone(zone
) {
4255 spin_lock_irqsave(&zone
->lock
, flags
);
4256 tmp
= (u64
)pages_min
* zone
->present_pages
;
4257 do_div(tmp
, lowmem_pages
);
4258 if (is_highmem(zone
)) {
4260 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
4261 * need highmem pages, so cap pages_min to a small
4264 * The (pages_high-pages_low) and (pages_low-pages_min)
4265 * deltas controls asynch page reclaim, and so should
4266 * not be capped for highmem.
4270 min_pages
= zone
->present_pages
/ 1024;
4271 if (min_pages
< SWAP_CLUSTER_MAX
)
4272 min_pages
= SWAP_CLUSTER_MAX
;
4273 if (min_pages
> 128)
4275 zone
->pages_min
= min_pages
;
4278 * If it's a lowmem zone, reserve a number of pages
4279 * proportionate to the zone's size.
4281 zone
->pages_min
= tmp
;
4284 zone
->pages_low
= zone
->pages_min
+ (tmp
>> 2);
4285 zone
->pages_high
= zone
->pages_min
+ (tmp
>> 1);
4286 setup_zone_migrate_reserve(zone
);
4287 spin_unlock_irqrestore(&zone
->lock
, flags
);
4290 /* update totalreserve_pages */
4291 calculate_totalreserve_pages();
4295 * Initialise min_free_kbytes.
4297 * For small machines we want it small (128k min). For large machines
4298 * we want it large (64MB max). But it is not linear, because network
4299 * bandwidth does not increase linearly with machine size. We use
4301 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
4302 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
4318 static int __init
init_per_zone_pages_min(void)
4320 unsigned long lowmem_kbytes
;
4322 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
4324 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
4325 if (min_free_kbytes
< 128)
4326 min_free_kbytes
= 128;
4327 if (min_free_kbytes
> 65536)
4328 min_free_kbytes
= 65536;
4329 setup_per_zone_pages_min();
4330 setup_per_zone_lowmem_reserve();
4333 module_init(init_per_zone_pages_min
)
4336 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
4337 * that we can call two helper functions whenever min_free_kbytes
4340 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
4341 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4343 proc_dointvec(table
, write
, file
, buffer
, length
, ppos
);
4345 setup_per_zone_pages_min();
4350 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
4351 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4356 rc
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4361 zone
->min_unmapped_pages
= (zone
->present_pages
*
4362 sysctl_min_unmapped_ratio
) / 100;
4366 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
4367 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4372 rc
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4377 zone
->min_slab_pages
= (zone
->present_pages
*
4378 sysctl_min_slab_ratio
) / 100;
4384 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
4385 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
4386 * whenever sysctl_lowmem_reserve_ratio changes.
4388 * The reserve ratio obviously has absolutely no relation with the
4389 * pages_min watermarks. The lowmem reserve ratio can only make sense
4390 * if in function of the boot time zone sizes.
4392 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
4393 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4395 proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4396 setup_per_zone_lowmem_reserve();
4401 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
4402 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
4403 * can have before it gets flushed back to buddy allocator.
4406 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
4407 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4413 ret
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4414 if (!write
|| (ret
== -EINVAL
))
4416 for_each_zone(zone
) {
4417 if (!populated_zone(zone
))
4419 for_each_online_cpu(cpu
) {
4421 high
= zone
->present_pages
/ percpu_pagelist_fraction
;
4422 setup_pagelist_highmark(zone_pcp(zone
, cpu
), high
);
4428 int hashdist
= HASHDIST_DEFAULT
;
4431 static int __init
set_hashdist(char *str
)
4435 hashdist
= simple_strtoul(str
, &str
, 0);
4438 __setup("hashdist=", set_hashdist
);
4442 * allocate a large system hash table from bootmem
4443 * - it is assumed that the hash table must contain an exact power-of-2
4444 * quantity of entries
4445 * - limit is the number of hash buckets, not the total allocation size
4447 void *__init
alloc_large_system_hash(const char *tablename
,
4448 unsigned long bucketsize
,
4449 unsigned long numentries
,
4452 unsigned int *_hash_shift
,
4453 unsigned int *_hash_mask
,
4454 unsigned long limit
)
4456 unsigned long long max
= limit
;
4457 unsigned long log2qty
, size
;
4460 /* allow the kernel cmdline to have a say */
4462 /* round applicable memory size up to nearest megabyte */
4463 numentries
= nr_kernel_pages
;
4464 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
4465 numentries
>>= 20 - PAGE_SHIFT
;
4466 numentries
<<= 20 - PAGE_SHIFT
;
4468 /* limit to 1 bucket per 2^scale bytes of low memory */
4469 if (scale
> PAGE_SHIFT
)
4470 numentries
>>= (scale
- PAGE_SHIFT
);
4472 numentries
<<= (PAGE_SHIFT
- scale
);
4474 /* Make sure we've got at least a 0-order allocation.. */
4475 if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
4476 numentries
= PAGE_SIZE
/ bucketsize
;
4478 numentries
= roundup_pow_of_two(numentries
);
4480 /* limit allocation size to 1/16 total memory by default */
4482 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
4483 do_div(max
, bucketsize
);
4486 if (numentries
> max
)
4489 log2qty
= ilog2(numentries
);
4492 size
= bucketsize
<< log2qty
;
4493 if (flags
& HASH_EARLY
)
4494 table
= alloc_bootmem_nopanic(size
);
4496 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
4498 unsigned long order
= get_order(size
);
4499 table
= (void*) __get_free_pages(GFP_ATOMIC
, order
);
4501 * If bucketsize is not a power-of-two, we may free
4502 * some pages at the end of hash table.
4505 unsigned long alloc_end
= (unsigned long)table
+
4506 (PAGE_SIZE
<< order
);
4507 unsigned long used
= (unsigned long)table
+
4509 split_page(virt_to_page(table
), order
);
4510 while (used
< alloc_end
) {
4516 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
4519 panic("Failed to allocate %s hash table\n", tablename
);
4521 printk(KERN_INFO
"%s hash table entries: %d (order: %d, %lu bytes)\n",
4524 ilog2(size
) - PAGE_SHIFT
,
4528 *_hash_shift
= log2qty
;
4530 *_hash_mask
= (1 << log2qty
) - 1;
4535 #ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
4536 struct page
*pfn_to_page(unsigned long pfn
)
4538 return __pfn_to_page(pfn
);
4540 unsigned long page_to_pfn(struct page
*page
)
4542 return __page_to_pfn(page
);
4544 EXPORT_SYMBOL(pfn_to_page
);
4545 EXPORT_SYMBOL(page_to_pfn
);
4546 #endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */
4548 /* Return a pointer to the bitmap storing bits affecting a block of pages */
4549 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
4552 #ifdef CONFIG_SPARSEMEM
4553 return __pfn_to_section(pfn
)->pageblock_flags
;
4555 return zone
->pageblock_flags
;
4556 #endif /* CONFIG_SPARSEMEM */
4559 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
4561 #ifdef CONFIG_SPARSEMEM
4562 pfn
&= (PAGES_PER_SECTION
-1);
4563 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
4565 pfn
= pfn
- zone
->zone_start_pfn
;
4566 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
4567 #endif /* CONFIG_SPARSEMEM */
4571 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4572 * @page: The page within the block of interest
4573 * @start_bitidx: The first bit of interest to retrieve
4574 * @end_bitidx: The last bit of interest
4575 * returns pageblock_bits flags
4577 unsigned long get_pageblock_flags_group(struct page
*page
,
4578 int start_bitidx
, int end_bitidx
)
4581 unsigned long *bitmap
;
4582 unsigned long pfn
, bitidx
;
4583 unsigned long flags
= 0;
4584 unsigned long value
= 1;
4586 zone
= page_zone(page
);
4587 pfn
= page_to_pfn(page
);
4588 bitmap
= get_pageblock_bitmap(zone
, pfn
);
4589 bitidx
= pfn_to_bitidx(zone
, pfn
);
4591 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
4592 if (test_bit(bitidx
+ start_bitidx
, bitmap
))
4599 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
4600 * @page: The page within the block of interest
4601 * @start_bitidx: The first bit of interest
4602 * @end_bitidx: The last bit of interest
4603 * @flags: The flags to set
4605 void set_pageblock_flags_group(struct page
*page
, unsigned long flags
,
4606 int start_bitidx
, int end_bitidx
)
4609 unsigned long *bitmap
;
4610 unsigned long pfn
, bitidx
;
4611 unsigned long value
= 1;
4613 zone
= page_zone(page
);
4614 pfn
= page_to_pfn(page
);
4615 bitmap
= get_pageblock_bitmap(zone
, pfn
);
4616 bitidx
= pfn_to_bitidx(zone
, pfn
);
4617 VM_BUG_ON(pfn
< zone
->zone_start_pfn
);
4618 VM_BUG_ON(pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
);
4620 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
4622 __set_bit(bitidx
+ start_bitidx
, bitmap
);
4624 __clear_bit(bitidx
+ start_bitidx
, bitmap
);
4628 * This is designed as sub function...plz see page_isolation.c also.
4629 * set/clear page block's type to be ISOLATE.
4630 * page allocater never alloc memory from ISOLATE block.
4633 int set_migratetype_isolate(struct page
*page
)
4636 unsigned long flags
;
4639 zone
= page_zone(page
);
4640 spin_lock_irqsave(&zone
->lock
, flags
);
4642 * In future, more migrate types will be able to be isolation target.
4644 if (get_pageblock_migratetype(page
) != MIGRATE_MOVABLE
)
4646 set_pageblock_migratetype(page
, MIGRATE_ISOLATE
);
4647 move_freepages_block(zone
, page
, MIGRATE_ISOLATE
);
4650 spin_unlock_irqrestore(&zone
->lock
, flags
);
4656 void unset_migratetype_isolate(struct page
*page
)
4659 unsigned long flags
;
4660 zone
= page_zone(page
);
4661 spin_lock_irqsave(&zone
->lock
, flags
);
4662 if (get_pageblock_migratetype(page
) != MIGRATE_ISOLATE
)
4664 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4665 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
4667 spin_unlock_irqrestore(&zone
->lock
, flags
);
4670 #ifdef CONFIG_MEMORY_HOTREMOVE
4672 * All pages in the range must be isolated before calling this.
4675 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
4681 unsigned long flags
;
4682 /* find the first valid pfn */
4683 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
4688 zone
= page_zone(pfn_to_page(pfn
));
4689 spin_lock_irqsave(&zone
->lock
, flags
);
4691 while (pfn
< end_pfn
) {
4692 if (!pfn_valid(pfn
)) {
4696 page
= pfn_to_page(pfn
);
4697 BUG_ON(page_count(page
));
4698 BUG_ON(!PageBuddy(page
));
4699 order
= page_order(page
);
4700 #ifdef CONFIG_DEBUG_VM
4701 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
4702 pfn
, 1 << order
, end_pfn
);
4704 list_del(&page
->lru
);
4705 rmv_page_order(page
);
4706 zone
->free_area
[order
].nr_free
--;
4707 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
4709 for (i
= 0; i
< (1 << order
); i
++)
4710 SetPageReserved((page
+i
));
4711 pfn
+= (1 << order
);
4713 spin_unlock_irqrestore(&zone
->lock
, flags
);