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
;
271 struct page
*p
= page
+ 1;
273 set_compound_page_dtor(page
, free_compound_page
);
274 set_compound_order(page
, order
);
276 for (i
= 1; i
< nr_pages
; i
++, p
++) {
277 if (unlikely((i
& (MAX_ORDER_NR_PAGES
- 1)) == 0))
278 p
= pfn_to_page(page_to_pfn(page
) + i
);
280 p
->first_page
= page
;
284 static void destroy_compound_page(struct page
*page
, unsigned long order
)
287 int nr_pages
= 1 << order
;
288 struct page
*p
= page
+ 1;
290 if (unlikely(compound_order(page
) != order
))
293 if (unlikely(!PageHead(page
)))
295 __ClearPageHead(page
);
296 for (i
= 1; i
< nr_pages
; i
++, p
++) {
297 if (unlikely((i
& (MAX_ORDER_NR_PAGES
- 1)) == 0))
298 p
= pfn_to_page(page_to_pfn(page
) + i
);
300 if (unlikely(!PageTail(p
) |
301 (p
->first_page
!= page
)))
307 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
312 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
313 * and __GFP_HIGHMEM from hard or soft interrupt context.
315 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
316 for (i
= 0; i
< (1 << order
); i
++)
317 clear_highpage(page
+ i
);
320 static inline void set_page_order(struct page
*page
, int order
)
322 set_page_private(page
, order
);
323 __SetPageBuddy(page
);
326 static inline void rmv_page_order(struct page
*page
)
328 __ClearPageBuddy(page
);
329 set_page_private(page
, 0);
333 * Locate the struct page for both the matching buddy in our
334 * pair (buddy1) and the combined O(n+1) page they form (page).
336 * 1) Any buddy B1 will have an order O twin B2 which satisfies
337 * the following equation:
339 * For example, if the starting buddy (buddy2) is #8 its order
341 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
343 * 2) Any buddy B will have an order O+1 parent P which
344 * satisfies the following equation:
347 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
349 static inline struct page
*
350 __page_find_buddy(struct page
*page
, unsigned long page_idx
, unsigned int order
)
352 unsigned long buddy_idx
= page_idx
^ (1 << order
);
354 return page
+ (buddy_idx
- page_idx
);
357 static inline unsigned long
358 __find_combined_index(unsigned long page_idx
, unsigned int order
)
360 return (page_idx
& ~(1 << order
));
364 * This function checks whether a page is free && is the buddy
365 * we can do coalesce a page and its buddy if
366 * (a) the buddy is not in a hole &&
367 * (b) the buddy is in the buddy system &&
368 * (c) a page and its buddy have the same order &&
369 * (d) a page and its buddy are in the same zone.
371 * For recording whether a page is in the buddy system, we use PG_buddy.
372 * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
374 * For recording page's order, we use page_private(page).
376 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
379 if (!pfn_valid_within(page_to_pfn(buddy
)))
382 if (page_zone_id(page
) != page_zone_id(buddy
))
385 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
386 BUG_ON(page_count(buddy
) != 0);
393 * Freeing function for a buddy system allocator.
395 * The concept of a buddy system is to maintain direct-mapped table
396 * (containing bit values) for memory blocks of various "orders".
397 * The bottom level table contains the map for the smallest allocatable
398 * units of memory (here, pages), and each level above it describes
399 * pairs of units from the levels below, hence, "buddies".
400 * At a high level, all that happens here is marking the table entry
401 * at the bottom level available, and propagating the changes upward
402 * as necessary, plus some accounting needed to play nicely with other
403 * parts of the VM system.
404 * At each level, we keep a list of pages, which are heads of continuous
405 * free pages of length of (1 << order) and marked with PG_buddy. Page's
406 * order is recorded in page_private(page) field.
407 * So when we are allocating or freeing one, we can derive the state of the
408 * other. That is, if we allocate a small block, and both were
409 * free, the remainder of the region must be split into blocks.
410 * If a block is freed, and its buddy is also free, then this
411 * triggers coalescing into a block of larger size.
416 static inline void __free_one_page(struct page
*page
,
417 struct zone
*zone
, unsigned int order
)
419 unsigned long page_idx
;
420 int order_size
= 1 << order
;
421 int migratetype
= get_pageblock_migratetype(page
);
423 if (unlikely(PageCompound(page
)))
424 destroy_compound_page(page
, order
);
426 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
428 VM_BUG_ON(page_idx
& (order_size
- 1));
429 VM_BUG_ON(bad_range(zone
, page
));
431 __mod_zone_page_state(zone
, NR_FREE_PAGES
, order_size
);
432 while (order
< MAX_ORDER
-1) {
433 unsigned long combined_idx
;
436 buddy
= __page_find_buddy(page
, page_idx
, order
);
437 if (!page_is_buddy(page
, buddy
, order
))
440 /* Our buddy is free, merge with it and move up one order. */
441 list_del(&buddy
->lru
);
442 zone
->free_area
[order
].nr_free
--;
443 rmv_page_order(buddy
);
444 combined_idx
= __find_combined_index(page_idx
, order
);
445 page
= page
+ (combined_idx
- page_idx
);
446 page_idx
= combined_idx
;
449 set_page_order(page
, order
);
451 &zone
->free_area
[order
].free_list
[migratetype
]);
452 zone
->free_area
[order
].nr_free
++;
455 static inline int free_pages_check(struct page
*page
)
457 if (unlikely(page_mapcount(page
) |
458 (page
->mapping
!= NULL
) |
459 (page_get_page_cgroup(page
) != NULL
) |
460 (page_count(page
) != 0) |
461 (page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)))
464 __ClearPageDirty(page
);
465 if (PageSwapBacked(page
))
466 __ClearPageSwapBacked(page
);
468 * For now, we report if PG_reserved was found set, but do not
469 * clear it, and do not free the page. But we shall soon need
470 * to do more, for when the ZERO_PAGE count wraps negative.
472 return PageReserved(page
);
476 * Frees a list of pages.
477 * Assumes all pages on list are in same zone, and of same order.
478 * count is the number of pages to free.
480 * If the zone was previously in an "all pages pinned" state then look to
481 * see if this freeing clears that state.
483 * And clear the zone's pages_scanned counter, to hold off the "all pages are
484 * pinned" detection logic.
486 static void free_pages_bulk(struct zone
*zone
, int count
,
487 struct list_head
*list
, int order
)
489 spin_lock(&zone
->lock
);
490 zone_clear_flag(zone
, ZONE_ALL_UNRECLAIMABLE
);
491 zone
->pages_scanned
= 0;
495 VM_BUG_ON(list_empty(list
));
496 page
= list_entry(list
->prev
, struct page
, lru
);
497 /* have to delete it as __free_one_page list manipulates */
498 list_del(&page
->lru
);
499 __free_one_page(page
, zone
, order
);
501 spin_unlock(&zone
->lock
);
504 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
)
506 spin_lock(&zone
->lock
);
507 zone_clear_flag(zone
, ZONE_ALL_UNRECLAIMABLE
);
508 zone
->pages_scanned
= 0;
509 __free_one_page(page
, zone
, order
);
510 spin_unlock(&zone
->lock
);
513 static void __free_pages_ok(struct page
*page
, unsigned int order
)
519 for (i
= 0 ; i
< (1 << order
) ; ++i
)
520 reserved
+= free_pages_check(page
+ i
);
524 if (!PageHighMem(page
)) {
525 debug_check_no_locks_freed(page_address(page
),PAGE_SIZE
<<order
);
526 debug_check_no_obj_freed(page_address(page
),
529 arch_free_page(page
, order
);
530 kernel_map_pages(page
, 1 << order
, 0);
532 local_irq_save(flags
);
533 __count_vm_events(PGFREE
, 1 << order
);
534 free_one_page(page_zone(page
), page
, order
);
535 local_irq_restore(flags
);
539 * permit the bootmem allocator to evade page validation on high-order frees
541 void __meminit
__free_pages_bootmem(struct page
*page
, unsigned int order
)
544 __ClearPageReserved(page
);
545 set_page_count(page
, 0);
546 set_page_refcounted(page
);
552 for (loop
= 0; loop
< BITS_PER_LONG
; loop
++) {
553 struct page
*p
= &page
[loop
];
555 if (loop
+ 1 < BITS_PER_LONG
)
557 __ClearPageReserved(p
);
558 set_page_count(p
, 0);
561 set_page_refcounted(page
);
562 __free_pages(page
, order
);
568 * The order of subdivision here is critical for the IO subsystem.
569 * Please do not alter this order without good reasons and regression
570 * testing. Specifically, as large blocks of memory are subdivided,
571 * the order in which smaller blocks are delivered depends on the order
572 * they're subdivided in this function. This is the primary factor
573 * influencing the order in which pages are delivered to the IO
574 * subsystem according to empirical testing, and this is also justified
575 * by considering the behavior of a buddy system containing a single
576 * large block of memory acted on by a series of small allocations.
577 * This behavior is a critical factor in sglist merging's success.
581 static inline void expand(struct zone
*zone
, struct page
*page
,
582 int low
, int high
, struct free_area
*area
,
585 unsigned long size
= 1 << high
;
591 VM_BUG_ON(bad_range(zone
, &page
[size
]));
592 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
594 set_page_order(&page
[size
], high
);
599 * This page is about to be returned from the page allocator
601 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
603 if (unlikely(page_mapcount(page
) |
604 (page
->mapping
!= NULL
) |
605 (page_get_page_cgroup(page
) != NULL
) |
606 (page_count(page
) != 0) |
607 (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)))
611 * For now, we report if PG_reserved was found set, but do not
612 * clear it, and do not allocate the page: as a safety net.
614 if (PageReserved(page
))
617 page
->flags
&= ~(1 << PG_uptodate
| 1 << PG_error
| 1 << PG_reclaim
|
618 1 << PG_referenced
| 1 << PG_arch_1
|
619 1 << PG_owner_priv_1
| 1 << PG_mappedtodisk
);
620 set_page_private(page
, 0);
621 set_page_refcounted(page
);
623 arch_alloc_page(page
, order
);
624 kernel_map_pages(page
, 1 << order
, 1);
626 if (gfp_flags
& __GFP_ZERO
)
627 prep_zero_page(page
, order
, gfp_flags
);
629 if (order
&& (gfp_flags
& __GFP_COMP
))
630 prep_compound_page(page
, order
);
636 * Go through the free lists for the given migratetype and remove
637 * the smallest available page from the freelists
639 static struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
642 unsigned int current_order
;
643 struct free_area
* area
;
646 /* Find a page of the appropriate size in the preferred list */
647 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
648 area
= &(zone
->free_area
[current_order
]);
649 if (list_empty(&area
->free_list
[migratetype
]))
652 page
= list_entry(area
->free_list
[migratetype
].next
,
654 list_del(&page
->lru
);
655 rmv_page_order(page
);
657 __mod_zone_page_state(zone
, NR_FREE_PAGES
, - (1UL << order
));
658 expand(zone
, page
, order
, current_order
, area
, migratetype
);
667 * This array describes the order lists are fallen back to when
668 * the free lists for the desirable migrate type are depleted
670 static int fallbacks
[MIGRATE_TYPES
][MIGRATE_TYPES
-1] = {
671 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
672 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
673 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
674 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
, MIGRATE_RESERVE
, MIGRATE_RESERVE
}, /* Never used */
678 * Move the free pages in a range to the free lists of the requested type.
679 * Note that start_page and end_pages are not aligned on a pageblock
680 * boundary. If alignment is required, use move_freepages_block()
682 static int move_freepages(struct zone
*zone
,
683 struct page
*start_page
, struct page
*end_page
,
690 #ifndef CONFIG_HOLES_IN_ZONE
692 * page_zone is not safe to call in this context when
693 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
694 * anyway as we check zone boundaries in move_freepages_block().
695 * Remove at a later date when no bug reports exist related to
696 * grouping pages by mobility
698 BUG_ON(page_zone(start_page
) != page_zone(end_page
));
701 for (page
= start_page
; page
<= end_page
;) {
702 /* Make sure we are not inadvertently changing nodes */
703 VM_BUG_ON(page_to_nid(page
) != zone_to_nid(zone
));
705 if (!pfn_valid_within(page_to_pfn(page
))) {
710 if (!PageBuddy(page
)) {
715 order
= page_order(page
);
716 list_del(&page
->lru
);
718 &zone
->free_area
[order
].free_list
[migratetype
]);
720 pages_moved
+= 1 << order
;
726 static int move_freepages_block(struct zone
*zone
, struct page
*page
,
729 unsigned long start_pfn
, end_pfn
;
730 struct page
*start_page
, *end_page
;
732 start_pfn
= page_to_pfn(page
);
733 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
734 start_page
= pfn_to_page(start_pfn
);
735 end_page
= start_page
+ pageblock_nr_pages
- 1;
736 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
738 /* Do not cross zone boundaries */
739 if (start_pfn
< zone
->zone_start_pfn
)
741 if (end_pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
744 return move_freepages(zone
, start_page
, end_page
, migratetype
);
747 /* Remove an element from the buddy allocator from the fallback list */
748 static struct page
*__rmqueue_fallback(struct zone
*zone
, int order
,
749 int start_migratetype
)
751 struct free_area
* area
;
756 /* Find the largest possible block of pages in the other list */
757 for (current_order
= MAX_ORDER
-1; current_order
>= order
;
759 for (i
= 0; i
< MIGRATE_TYPES
- 1; i
++) {
760 migratetype
= fallbacks
[start_migratetype
][i
];
762 /* MIGRATE_RESERVE handled later if necessary */
763 if (migratetype
== MIGRATE_RESERVE
)
766 area
= &(zone
->free_area
[current_order
]);
767 if (list_empty(&area
->free_list
[migratetype
]))
770 page
= list_entry(area
->free_list
[migratetype
].next
,
775 * If breaking a large block of pages, move all free
776 * pages to the preferred allocation list. If falling
777 * back for a reclaimable kernel allocation, be more
778 * agressive about taking ownership of free pages
780 if (unlikely(current_order
>= (pageblock_order
>> 1)) ||
781 start_migratetype
== MIGRATE_RECLAIMABLE
) {
783 pages
= move_freepages_block(zone
, page
,
786 /* Claim the whole block if over half of it is free */
787 if (pages
>= (1 << (pageblock_order
-1)))
788 set_pageblock_migratetype(page
,
791 migratetype
= start_migratetype
;
794 /* Remove the page from the freelists */
795 list_del(&page
->lru
);
796 rmv_page_order(page
);
797 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
800 if (current_order
== pageblock_order
)
801 set_pageblock_migratetype(page
,
804 expand(zone
, page
, order
, current_order
, area
, migratetype
);
809 /* Use MIGRATE_RESERVE rather than fail an allocation */
810 return __rmqueue_smallest(zone
, order
, MIGRATE_RESERVE
);
814 * Do the hard work of removing an element from the buddy allocator.
815 * Call me with the zone->lock already held.
817 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
822 page
= __rmqueue_smallest(zone
, order
, migratetype
);
825 page
= __rmqueue_fallback(zone
, order
, migratetype
);
831 * Obtain a specified number of elements from the buddy allocator, all under
832 * a single hold of the lock, for efficiency. Add them to the supplied list.
833 * Returns the number of new pages which were placed at *list.
835 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
836 unsigned long count
, struct list_head
*list
,
841 spin_lock(&zone
->lock
);
842 for (i
= 0; i
< count
; ++i
) {
843 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
844 if (unlikely(page
== NULL
))
848 * Split buddy pages returned by expand() are received here
849 * in physical page order. The page is added to the callers and
850 * list and the list head then moves forward. From the callers
851 * perspective, the linked list is ordered by page number in
852 * some conditions. This is useful for IO devices that can
853 * merge IO requests if the physical pages are ordered
856 list_add(&page
->lru
, list
);
857 set_page_private(page
, migratetype
);
860 spin_unlock(&zone
->lock
);
866 * Called from the vmstat counter updater to drain pagesets of this
867 * currently executing processor on remote nodes after they have
870 * Note that this function must be called with the thread pinned to
871 * a single processor.
873 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
878 local_irq_save(flags
);
879 if (pcp
->count
>= pcp
->batch
)
880 to_drain
= pcp
->batch
;
882 to_drain
= pcp
->count
;
883 free_pages_bulk(zone
, to_drain
, &pcp
->list
, 0);
884 pcp
->count
-= to_drain
;
885 local_irq_restore(flags
);
890 * Drain pages of the indicated processor.
892 * The processor must either be the current processor and the
893 * thread pinned to the current processor or a processor that
896 static void drain_pages(unsigned int cpu
)
901 for_each_zone(zone
) {
902 struct per_cpu_pageset
*pset
;
903 struct per_cpu_pages
*pcp
;
905 if (!populated_zone(zone
))
908 pset
= zone_pcp(zone
, cpu
);
911 local_irq_save(flags
);
912 free_pages_bulk(zone
, pcp
->count
, &pcp
->list
, 0);
914 local_irq_restore(flags
);
919 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
921 void drain_local_pages(void *arg
)
923 drain_pages(smp_processor_id());
927 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
929 void drain_all_pages(void)
931 on_each_cpu(drain_local_pages
, NULL
, 1);
934 #ifdef CONFIG_HIBERNATION
936 void mark_free_pages(struct zone
*zone
)
938 unsigned long pfn
, max_zone_pfn
;
941 struct list_head
*curr
;
943 if (!zone
->spanned_pages
)
946 spin_lock_irqsave(&zone
->lock
, flags
);
948 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
949 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
950 if (pfn_valid(pfn
)) {
951 struct page
*page
= pfn_to_page(pfn
);
953 if (!swsusp_page_is_forbidden(page
))
954 swsusp_unset_page_free(page
);
957 for_each_migratetype_order(order
, t
) {
958 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
961 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
962 for (i
= 0; i
< (1UL << order
); i
++)
963 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
966 spin_unlock_irqrestore(&zone
->lock
, flags
);
968 #endif /* CONFIG_PM */
971 * Free a 0-order page
973 static void free_hot_cold_page(struct page
*page
, int cold
)
975 struct zone
*zone
= page_zone(page
);
976 struct per_cpu_pages
*pcp
;
980 page
->mapping
= NULL
;
981 if (free_pages_check(page
))
984 if (!PageHighMem(page
)) {
985 debug_check_no_locks_freed(page_address(page
), PAGE_SIZE
);
986 debug_check_no_obj_freed(page_address(page
), PAGE_SIZE
);
988 arch_free_page(page
, 0);
989 kernel_map_pages(page
, 1, 0);
991 pcp
= &zone_pcp(zone
, get_cpu())->pcp
;
992 local_irq_save(flags
);
993 __count_vm_event(PGFREE
);
995 list_add_tail(&page
->lru
, &pcp
->list
);
997 list_add(&page
->lru
, &pcp
->list
);
998 set_page_private(page
, get_pageblock_migratetype(page
));
1000 if (pcp
->count
>= pcp
->high
) {
1001 free_pages_bulk(zone
, pcp
->batch
, &pcp
->list
, 0);
1002 pcp
->count
-= pcp
->batch
;
1004 local_irq_restore(flags
);
1008 void free_hot_page(struct page
*page
)
1010 free_hot_cold_page(page
, 0);
1013 void free_cold_page(struct page
*page
)
1015 free_hot_cold_page(page
, 1);
1019 * split_page takes a non-compound higher-order page, and splits it into
1020 * n (1<<order) sub-pages: page[0..n]
1021 * Each sub-page must be freed individually.
1023 * Note: this is probably too low level an operation for use in drivers.
1024 * Please consult with lkml before using this in your driver.
1026 void split_page(struct page
*page
, unsigned int order
)
1030 VM_BUG_ON(PageCompound(page
));
1031 VM_BUG_ON(!page_count(page
));
1032 for (i
= 1; i
< (1 << order
); i
++)
1033 set_page_refcounted(page
+ i
);
1037 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1038 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1041 static struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
1042 struct zone
*zone
, int order
, gfp_t gfp_flags
)
1044 unsigned long flags
;
1046 int cold
= !!(gfp_flags
& __GFP_COLD
);
1048 int migratetype
= allocflags_to_migratetype(gfp_flags
);
1052 if (likely(order
== 0)) {
1053 struct per_cpu_pages
*pcp
;
1055 pcp
= &zone_pcp(zone
, cpu
)->pcp
;
1056 local_irq_save(flags
);
1058 pcp
->count
= rmqueue_bulk(zone
, 0,
1059 pcp
->batch
, &pcp
->list
, migratetype
);
1060 if (unlikely(!pcp
->count
))
1064 /* Find a page of the appropriate migrate type */
1066 list_for_each_entry_reverse(page
, &pcp
->list
, lru
)
1067 if (page_private(page
) == migratetype
)
1070 list_for_each_entry(page
, &pcp
->list
, lru
)
1071 if (page_private(page
) == migratetype
)
1075 /* Allocate more to the pcp list if necessary */
1076 if (unlikely(&page
->lru
== &pcp
->list
)) {
1077 pcp
->count
+= rmqueue_bulk(zone
, 0,
1078 pcp
->batch
, &pcp
->list
, migratetype
);
1079 page
= list_entry(pcp
->list
.next
, struct page
, lru
);
1082 list_del(&page
->lru
);
1085 spin_lock_irqsave(&zone
->lock
, flags
);
1086 page
= __rmqueue(zone
, order
, migratetype
);
1087 spin_unlock(&zone
->lock
);
1092 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
1093 zone_statistics(preferred_zone
, zone
);
1094 local_irq_restore(flags
);
1097 VM_BUG_ON(bad_range(zone
, page
));
1098 if (prep_new_page(page
, order
, gfp_flags
))
1103 local_irq_restore(flags
);
1108 #define ALLOC_NO_WATERMARKS 0x01 /* don't check watermarks at all */
1109 #define ALLOC_WMARK_MIN 0x02 /* use pages_min watermark */
1110 #define ALLOC_WMARK_LOW 0x04 /* use pages_low watermark */
1111 #define ALLOC_WMARK_HIGH 0x08 /* use pages_high watermark */
1112 #define ALLOC_HARDER 0x10 /* try to alloc harder */
1113 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
1114 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
1116 #ifdef CONFIG_FAIL_PAGE_ALLOC
1118 static struct fail_page_alloc_attr
{
1119 struct fault_attr attr
;
1121 u32 ignore_gfp_highmem
;
1122 u32 ignore_gfp_wait
;
1125 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1127 struct dentry
*ignore_gfp_highmem_file
;
1128 struct dentry
*ignore_gfp_wait_file
;
1129 struct dentry
*min_order_file
;
1131 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1133 } fail_page_alloc
= {
1134 .attr
= FAULT_ATTR_INITIALIZER
,
1135 .ignore_gfp_wait
= 1,
1136 .ignore_gfp_highmem
= 1,
1140 static int __init
setup_fail_page_alloc(char *str
)
1142 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
1144 __setup("fail_page_alloc=", setup_fail_page_alloc
);
1146 static int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1148 if (order
< fail_page_alloc
.min_order
)
1150 if (gfp_mask
& __GFP_NOFAIL
)
1152 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
1154 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
1157 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
1160 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1162 static int __init
fail_page_alloc_debugfs(void)
1164 mode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
1168 err
= init_fault_attr_dentries(&fail_page_alloc
.attr
,
1172 dir
= fail_page_alloc
.attr
.dentries
.dir
;
1174 fail_page_alloc
.ignore_gfp_wait_file
=
1175 debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
1176 &fail_page_alloc
.ignore_gfp_wait
);
1178 fail_page_alloc
.ignore_gfp_highmem_file
=
1179 debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
1180 &fail_page_alloc
.ignore_gfp_highmem
);
1181 fail_page_alloc
.min_order_file
=
1182 debugfs_create_u32("min-order", mode
, dir
,
1183 &fail_page_alloc
.min_order
);
1185 if (!fail_page_alloc
.ignore_gfp_wait_file
||
1186 !fail_page_alloc
.ignore_gfp_highmem_file
||
1187 !fail_page_alloc
.min_order_file
) {
1189 debugfs_remove(fail_page_alloc
.ignore_gfp_wait_file
);
1190 debugfs_remove(fail_page_alloc
.ignore_gfp_highmem_file
);
1191 debugfs_remove(fail_page_alloc
.min_order_file
);
1192 cleanup_fault_attr_dentries(&fail_page_alloc
.attr
);
1198 late_initcall(fail_page_alloc_debugfs
);
1200 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1202 #else /* CONFIG_FAIL_PAGE_ALLOC */
1204 static inline int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1209 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1212 * Return 1 if free pages are above 'mark'. This takes into account the order
1213 * of the allocation.
1215 int zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1216 int classzone_idx
, int alloc_flags
)
1218 /* free_pages my go negative - that's OK */
1220 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
) - (1 << order
) + 1;
1223 if (alloc_flags
& ALLOC_HIGH
)
1225 if (alloc_flags
& ALLOC_HARDER
)
1228 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
1230 for (o
= 0; o
< order
; o
++) {
1231 /* At the next order, this order's pages become unavailable */
1232 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1234 /* Require fewer higher order pages to be free */
1237 if (free_pages
<= min
)
1245 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1246 * skip over zones that are not allowed by the cpuset, or that have
1247 * been recently (in last second) found to be nearly full. See further
1248 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1249 * that have to skip over a lot of full or unallowed zones.
1251 * If the zonelist cache is present in the passed in zonelist, then
1252 * returns a pointer to the allowed node mask (either the current
1253 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1255 * If the zonelist cache is not available for this zonelist, does
1256 * nothing and returns NULL.
1258 * If the fullzones BITMAP in the zonelist cache is stale (more than
1259 * a second since last zap'd) then we zap it out (clear its bits.)
1261 * We hold off even calling zlc_setup, until after we've checked the
1262 * first zone in the zonelist, on the theory that most allocations will
1263 * be satisfied from that first zone, so best to examine that zone as
1264 * quickly as we can.
1266 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1268 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1269 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1271 zlc
= zonelist
->zlcache_ptr
;
1275 if (time_after(jiffies
, zlc
->last_full_zap
+ HZ
)) {
1276 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1277 zlc
->last_full_zap
= jiffies
;
1280 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1281 &cpuset_current_mems_allowed
:
1282 &node_states
[N_HIGH_MEMORY
];
1283 return allowednodes
;
1287 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1288 * if it is worth looking at further for free memory:
1289 * 1) Check that the zone isn't thought to be full (doesn't have its
1290 * bit set in the zonelist_cache fullzones BITMAP).
1291 * 2) Check that the zones node (obtained from the zonelist_cache
1292 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1293 * Return true (non-zero) if zone is worth looking at further, or
1294 * else return false (zero) if it is not.
1296 * This check -ignores- the distinction between various watermarks,
1297 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1298 * found to be full for any variation of these watermarks, it will
1299 * be considered full for up to one second by all requests, unless
1300 * we are so low on memory on all allowed nodes that we are forced
1301 * into the second scan of the zonelist.
1303 * In the second scan we ignore this zonelist cache and exactly
1304 * apply the watermarks to all zones, even it is slower to do so.
1305 * We are low on memory in the second scan, and should leave no stone
1306 * unturned looking for a free page.
1308 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1309 nodemask_t
*allowednodes
)
1311 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1312 int i
; /* index of *z in zonelist zones */
1313 int n
; /* node that zone *z is on */
1315 zlc
= zonelist
->zlcache_ptr
;
1319 i
= z
- zonelist
->_zonerefs
;
1322 /* This zone is worth trying if it is allowed but not full */
1323 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1327 * Given 'z' scanning a zonelist, set the corresponding bit in
1328 * zlc->fullzones, so that subsequent attempts to allocate a page
1329 * from that zone don't waste time re-examining it.
1331 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1333 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1334 int i
; /* index of *z in zonelist zones */
1336 zlc
= zonelist
->zlcache_ptr
;
1340 i
= z
- zonelist
->_zonerefs
;
1342 set_bit(i
, zlc
->fullzones
);
1345 #else /* CONFIG_NUMA */
1347 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1352 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1353 nodemask_t
*allowednodes
)
1358 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1361 #endif /* CONFIG_NUMA */
1364 * get_page_from_freelist goes through the zonelist trying to allocate
1367 static struct page
*
1368 get_page_from_freelist(gfp_t gfp_mask
, nodemask_t
*nodemask
, unsigned int order
,
1369 struct zonelist
*zonelist
, int high_zoneidx
, int alloc_flags
)
1372 struct page
*page
= NULL
;
1374 struct zone
*zone
, *preferred_zone
;
1375 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1376 int zlc_active
= 0; /* set if using zonelist_cache */
1377 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1379 (void)first_zones_zonelist(zonelist
, high_zoneidx
, nodemask
,
1381 if (!preferred_zone
)
1384 classzone_idx
= zone_idx(preferred_zone
);
1388 * Scan zonelist, looking for a zone with enough free.
1389 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1391 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
1392 high_zoneidx
, nodemask
) {
1393 if (NUMA_BUILD
&& zlc_active
&&
1394 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1396 if ((alloc_flags
& ALLOC_CPUSET
) &&
1397 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1400 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
1402 if (alloc_flags
& ALLOC_WMARK_MIN
)
1403 mark
= zone
->pages_min
;
1404 else if (alloc_flags
& ALLOC_WMARK_LOW
)
1405 mark
= zone
->pages_low
;
1407 mark
= zone
->pages_high
;
1408 if (!zone_watermark_ok(zone
, order
, mark
,
1409 classzone_idx
, alloc_flags
)) {
1410 if (!zone_reclaim_mode
||
1411 !zone_reclaim(zone
, gfp_mask
, order
))
1412 goto this_zone_full
;
1416 page
= buffered_rmqueue(preferred_zone
, zone
, order
, gfp_mask
);
1421 zlc_mark_zone_full(zonelist
, z
);
1423 if (NUMA_BUILD
&& !did_zlc_setup
) {
1424 /* we do zlc_setup after the first zone is tried */
1425 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1431 if (unlikely(NUMA_BUILD
&& page
== NULL
&& zlc_active
)) {
1432 /* Disable zlc cache for second zonelist scan */
1440 * This is the 'heart' of the zoned buddy allocator.
1443 __alloc_pages_internal(gfp_t gfp_mask
, unsigned int order
,
1444 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
1446 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
1447 enum zone_type high_zoneidx
= gfp_zone(gfp_mask
);
1451 struct reclaim_state reclaim_state
;
1452 struct task_struct
*p
= current
;
1455 unsigned long did_some_progress
;
1456 unsigned long pages_reclaimed
= 0;
1458 might_sleep_if(wait
);
1460 if (should_fail_alloc_page(gfp_mask
, order
))
1464 z
= zonelist
->_zonerefs
; /* the list of zones suitable for gfp_mask */
1466 if (unlikely(!z
->zone
)) {
1468 * Happens if we have an empty zonelist as a result of
1469 * GFP_THISNODE being used on a memoryless node
1474 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
, order
,
1475 zonelist
, high_zoneidx
, ALLOC_WMARK_LOW
|ALLOC_CPUSET
);
1480 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
1481 * __GFP_NOWARN set) should not cause reclaim since the subsystem
1482 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
1483 * using a larger set of nodes after it has established that the
1484 * allowed per node queues are empty and that nodes are
1487 if (NUMA_BUILD
&& (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
1490 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
)
1491 wakeup_kswapd(zone
, order
);
1494 * OK, we're below the kswapd watermark and have kicked background
1495 * reclaim. Now things get more complex, so set up alloc_flags according
1496 * to how we want to proceed.
1498 * The caller may dip into page reserves a bit more if the caller
1499 * cannot run direct reclaim, or if the caller has realtime scheduling
1500 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
1501 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1503 alloc_flags
= ALLOC_WMARK_MIN
;
1504 if ((unlikely(rt_task(p
)) && !in_interrupt()) || !wait
)
1505 alloc_flags
|= ALLOC_HARDER
;
1506 if (gfp_mask
& __GFP_HIGH
)
1507 alloc_flags
|= ALLOC_HIGH
;
1509 alloc_flags
|= ALLOC_CPUSET
;
1512 * Go through the zonelist again. Let __GFP_HIGH and allocations
1513 * coming from realtime tasks go deeper into reserves.
1515 * This is the last chance, in general, before the goto nopage.
1516 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1517 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1519 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
, zonelist
,
1520 high_zoneidx
, alloc_flags
);
1524 /* This allocation should allow future memory freeing. */
1527 if (((p
->flags
& PF_MEMALLOC
) || unlikely(test_thread_flag(TIF_MEMDIE
)))
1528 && !in_interrupt()) {
1529 if (!(gfp_mask
& __GFP_NOMEMALLOC
)) {
1531 /* go through the zonelist yet again, ignoring mins */
1532 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
1533 zonelist
, high_zoneidx
, ALLOC_NO_WATERMARKS
);
1536 if (gfp_mask
& __GFP_NOFAIL
) {
1537 congestion_wait(WRITE
, HZ
/50);
1544 /* Atomic allocations - we can't balance anything */
1550 /* We now go into synchronous reclaim */
1551 cpuset_memory_pressure_bump();
1552 p
->flags
|= PF_MEMALLOC
;
1553 reclaim_state
.reclaimed_slab
= 0;
1554 p
->reclaim_state
= &reclaim_state
;
1556 did_some_progress
= try_to_free_pages(zonelist
, order
, gfp_mask
);
1558 p
->reclaim_state
= NULL
;
1559 p
->flags
&= ~PF_MEMALLOC
;
1566 if (likely(did_some_progress
)) {
1567 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
1568 zonelist
, high_zoneidx
, alloc_flags
);
1571 } else if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
1572 if (!try_set_zone_oom(zonelist
, gfp_mask
)) {
1573 schedule_timeout_uninterruptible(1);
1578 * Go through the zonelist yet one more time, keep
1579 * very high watermark here, this is only to catch
1580 * a parallel oom killing, we must fail if we're still
1581 * under heavy pressure.
1583 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
,
1584 order
, zonelist
, high_zoneidx
,
1585 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
);
1587 clear_zonelist_oom(zonelist
, gfp_mask
);
1591 /* The OOM killer will not help higher order allocs so fail */
1592 if (order
> PAGE_ALLOC_COSTLY_ORDER
) {
1593 clear_zonelist_oom(zonelist
, gfp_mask
);
1597 out_of_memory(zonelist
, gfp_mask
, order
);
1598 clear_zonelist_oom(zonelist
, gfp_mask
);
1603 * Don't let big-order allocations loop unless the caller explicitly
1604 * requests that. Wait for some write requests to complete then retry.
1606 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
1607 * means __GFP_NOFAIL, but that may not be true in other
1610 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
1611 * specified, then we retry until we no longer reclaim any pages
1612 * (above), or we've reclaimed an order of pages at least as
1613 * large as the allocation's order. In both cases, if the
1614 * allocation still fails, we stop retrying.
1616 pages_reclaimed
+= did_some_progress
;
1618 if (!(gfp_mask
& __GFP_NORETRY
)) {
1619 if (order
<= PAGE_ALLOC_COSTLY_ORDER
) {
1622 if (gfp_mask
& __GFP_REPEAT
&&
1623 pages_reclaimed
< (1 << order
))
1626 if (gfp_mask
& __GFP_NOFAIL
)
1630 congestion_wait(WRITE
, HZ
/50);
1635 if (!(gfp_mask
& __GFP_NOWARN
) && printk_ratelimit()) {
1636 printk(KERN_WARNING
"%s: page allocation failure."
1637 " order:%d, mode:0x%x\n",
1638 p
->comm
, order
, gfp_mask
);
1645 EXPORT_SYMBOL(__alloc_pages_internal
);
1648 * Common helper functions.
1650 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
1653 page
= alloc_pages(gfp_mask
, order
);
1656 return (unsigned long) page_address(page
);
1659 EXPORT_SYMBOL(__get_free_pages
);
1661 unsigned long get_zeroed_page(gfp_t gfp_mask
)
1666 * get_zeroed_page() returns a 32-bit address, which cannot represent
1669 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
1671 page
= alloc_pages(gfp_mask
| __GFP_ZERO
, 0);
1673 return (unsigned long) page_address(page
);
1677 EXPORT_SYMBOL(get_zeroed_page
);
1679 void __pagevec_free(struct pagevec
*pvec
)
1681 int i
= pagevec_count(pvec
);
1684 free_hot_cold_page(pvec
->pages
[i
], pvec
->cold
);
1687 void __free_pages(struct page
*page
, unsigned int order
)
1689 if (put_page_testzero(page
)) {
1691 free_hot_page(page
);
1693 __free_pages_ok(page
, order
);
1697 EXPORT_SYMBOL(__free_pages
);
1699 void free_pages(unsigned long addr
, unsigned int order
)
1702 VM_BUG_ON(!virt_addr_valid((void *)addr
));
1703 __free_pages(virt_to_page((void *)addr
), order
);
1707 EXPORT_SYMBOL(free_pages
);
1710 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
1711 * @size: the number of bytes to allocate
1712 * @gfp_mask: GFP flags for the allocation
1714 * This function is similar to alloc_pages(), except that it allocates the
1715 * minimum number of pages to satisfy the request. alloc_pages() can only
1716 * allocate memory in power-of-two pages.
1718 * This function is also limited by MAX_ORDER.
1720 * Memory allocated by this function must be released by free_pages_exact().
1722 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
1724 unsigned int order
= get_order(size
);
1727 addr
= __get_free_pages(gfp_mask
, order
);
1729 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
1730 unsigned long used
= addr
+ PAGE_ALIGN(size
);
1732 split_page(virt_to_page(addr
), order
);
1733 while (used
< alloc_end
) {
1739 return (void *)addr
;
1741 EXPORT_SYMBOL(alloc_pages_exact
);
1744 * free_pages_exact - release memory allocated via alloc_pages_exact()
1745 * @virt: the value returned by alloc_pages_exact.
1746 * @size: size of allocation, same value as passed to alloc_pages_exact().
1748 * Release the memory allocated by a previous call to alloc_pages_exact.
1750 void free_pages_exact(void *virt
, size_t size
)
1752 unsigned long addr
= (unsigned long)virt
;
1753 unsigned long end
= addr
+ PAGE_ALIGN(size
);
1755 while (addr
< end
) {
1760 EXPORT_SYMBOL(free_pages_exact
);
1762 static unsigned int nr_free_zone_pages(int offset
)
1767 /* Just pick one node, since fallback list is circular */
1768 unsigned int sum
= 0;
1770 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
1772 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
1773 unsigned long size
= zone
->present_pages
;
1774 unsigned long high
= zone
->pages_high
;
1783 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
1785 unsigned int nr_free_buffer_pages(void)
1787 return nr_free_zone_pages(gfp_zone(GFP_USER
));
1789 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
1792 * Amount of free RAM allocatable within all zones
1794 unsigned int nr_free_pagecache_pages(void)
1796 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
1799 static inline void show_node(struct zone
*zone
)
1802 printk("Node %d ", zone_to_nid(zone
));
1805 void si_meminfo(struct sysinfo
*val
)
1807 val
->totalram
= totalram_pages
;
1809 val
->freeram
= global_page_state(NR_FREE_PAGES
);
1810 val
->bufferram
= nr_blockdev_pages();
1811 val
->totalhigh
= totalhigh_pages
;
1812 val
->freehigh
= nr_free_highpages();
1813 val
->mem_unit
= PAGE_SIZE
;
1816 EXPORT_SYMBOL(si_meminfo
);
1819 void si_meminfo_node(struct sysinfo
*val
, int nid
)
1821 pg_data_t
*pgdat
= NODE_DATA(nid
);
1823 val
->totalram
= pgdat
->node_present_pages
;
1824 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
1825 #ifdef CONFIG_HIGHMEM
1826 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
1827 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
1833 val
->mem_unit
= PAGE_SIZE
;
1837 #define K(x) ((x) << (PAGE_SHIFT-10))
1840 * Show free area list (used inside shift_scroll-lock stuff)
1841 * We also calculate the percentage fragmentation. We do this by counting the
1842 * memory on each free list with the exception of the first item on the list.
1844 void show_free_areas(void)
1849 for_each_zone(zone
) {
1850 if (!populated_zone(zone
))
1854 printk("%s per-cpu:\n", zone
->name
);
1856 for_each_online_cpu(cpu
) {
1857 struct per_cpu_pageset
*pageset
;
1859 pageset
= zone_pcp(zone
, cpu
);
1861 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
1862 cpu
, pageset
->pcp
.high
,
1863 pageset
->pcp
.batch
, pageset
->pcp
.count
);
1867 printk("Active_anon:%lu active_file:%lu inactive_anon:%lu\n"
1868 " inactive_file:%lu"
1869 //TODO: check/adjust line lengths
1870 #ifdef CONFIG_UNEVICTABLE_LRU
1873 " dirty:%lu writeback:%lu unstable:%lu\n"
1874 " free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n",
1875 global_page_state(NR_ACTIVE_ANON
),
1876 global_page_state(NR_ACTIVE_FILE
),
1877 global_page_state(NR_INACTIVE_ANON
),
1878 global_page_state(NR_INACTIVE_FILE
),
1879 #ifdef CONFIG_UNEVICTABLE_LRU
1880 global_page_state(NR_UNEVICTABLE
),
1882 global_page_state(NR_FILE_DIRTY
),
1883 global_page_state(NR_WRITEBACK
),
1884 global_page_state(NR_UNSTABLE_NFS
),
1885 global_page_state(NR_FREE_PAGES
),
1886 global_page_state(NR_SLAB_RECLAIMABLE
) +
1887 global_page_state(NR_SLAB_UNRECLAIMABLE
),
1888 global_page_state(NR_FILE_MAPPED
),
1889 global_page_state(NR_PAGETABLE
),
1890 global_page_state(NR_BOUNCE
));
1892 for_each_zone(zone
) {
1895 if (!populated_zone(zone
))
1904 " active_anon:%lukB"
1905 " inactive_anon:%lukB"
1906 " active_file:%lukB"
1907 " inactive_file:%lukB"
1908 #ifdef CONFIG_UNEVICTABLE_LRU
1909 " unevictable:%lukB"
1912 " pages_scanned:%lu"
1913 " all_unreclaimable? %s"
1916 K(zone_page_state(zone
, NR_FREE_PAGES
)),
1919 K(zone
->pages_high
),
1920 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
1921 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
1922 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
1923 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
1924 #ifdef CONFIG_UNEVICTABLE_LRU
1925 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
1927 K(zone
->present_pages
),
1928 zone
->pages_scanned
,
1929 (zone_is_all_unreclaimable(zone
) ? "yes" : "no")
1931 printk("lowmem_reserve[]:");
1932 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
1933 printk(" %lu", zone
->lowmem_reserve
[i
]);
1937 for_each_zone(zone
) {
1938 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
1940 if (!populated_zone(zone
))
1944 printk("%s: ", zone
->name
);
1946 spin_lock_irqsave(&zone
->lock
, flags
);
1947 for (order
= 0; order
< MAX_ORDER
; order
++) {
1948 nr
[order
] = zone
->free_area
[order
].nr_free
;
1949 total
+= nr
[order
] << order
;
1951 spin_unlock_irqrestore(&zone
->lock
, flags
);
1952 for (order
= 0; order
< MAX_ORDER
; order
++)
1953 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
1954 printk("= %lukB\n", K(total
));
1957 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
1959 show_swap_cache_info();
1962 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
1964 zoneref
->zone
= zone
;
1965 zoneref
->zone_idx
= zone_idx(zone
);
1969 * Builds allocation fallback zone lists.
1971 * Add all populated zones of a node to the zonelist.
1973 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
1974 int nr_zones
, enum zone_type zone_type
)
1978 BUG_ON(zone_type
>= MAX_NR_ZONES
);
1983 zone
= pgdat
->node_zones
+ zone_type
;
1984 if (populated_zone(zone
)) {
1985 zoneref_set_zone(zone
,
1986 &zonelist
->_zonerefs
[nr_zones
++]);
1987 check_highest_zone(zone_type
);
1990 } while (zone_type
);
1997 * 0 = automatic detection of better ordering.
1998 * 1 = order by ([node] distance, -zonetype)
1999 * 2 = order by (-zonetype, [node] distance)
2001 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
2002 * the same zonelist. So only NUMA can configure this param.
2004 #define ZONELIST_ORDER_DEFAULT 0
2005 #define ZONELIST_ORDER_NODE 1
2006 #define ZONELIST_ORDER_ZONE 2
2008 /* zonelist order in the kernel.
2009 * set_zonelist_order() will set this to NODE or ZONE.
2011 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2012 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
2016 /* The value user specified ....changed by config */
2017 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2018 /* string for sysctl */
2019 #define NUMA_ZONELIST_ORDER_LEN 16
2020 char numa_zonelist_order
[16] = "default";
2023 * interface for configure zonelist ordering.
2024 * command line option "numa_zonelist_order"
2025 * = "[dD]efault - default, automatic configuration.
2026 * = "[nN]ode - order by node locality, then by zone within node
2027 * = "[zZ]one - order by zone, then by locality within zone
2030 static int __parse_numa_zonelist_order(char *s
)
2032 if (*s
== 'd' || *s
== 'D') {
2033 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2034 } else if (*s
== 'n' || *s
== 'N') {
2035 user_zonelist_order
= ZONELIST_ORDER_NODE
;
2036 } else if (*s
== 'z' || *s
== 'Z') {
2037 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
2040 "Ignoring invalid numa_zonelist_order value: "
2047 static __init
int setup_numa_zonelist_order(char *s
)
2050 return __parse_numa_zonelist_order(s
);
2053 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
2056 * sysctl handler for numa_zonelist_order
2058 int numa_zonelist_order_handler(ctl_table
*table
, int write
,
2059 struct file
*file
, void __user
*buffer
, size_t *length
,
2062 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
2066 strncpy(saved_string
, (char*)table
->data
,
2067 NUMA_ZONELIST_ORDER_LEN
);
2068 ret
= proc_dostring(table
, write
, file
, buffer
, length
, ppos
);
2072 int oldval
= user_zonelist_order
;
2073 if (__parse_numa_zonelist_order((char*)table
->data
)) {
2075 * bogus value. restore saved string
2077 strncpy((char*)table
->data
, saved_string
,
2078 NUMA_ZONELIST_ORDER_LEN
);
2079 user_zonelist_order
= oldval
;
2080 } else if (oldval
!= user_zonelist_order
)
2081 build_all_zonelists();
2087 #define MAX_NODE_LOAD (num_online_nodes())
2088 static int node_load
[MAX_NUMNODES
];
2091 * find_next_best_node - find the next node that should appear in a given node's fallback list
2092 * @node: node whose fallback list we're appending
2093 * @used_node_mask: nodemask_t of already used nodes
2095 * We use a number of factors to determine which is the next node that should
2096 * appear on a given node's fallback list. The node should not have appeared
2097 * already in @node's fallback list, and it should be the next closest node
2098 * according to the distance array (which contains arbitrary distance values
2099 * from each node to each node in the system), and should also prefer nodes
2100 * with no CPUs, since presumably they'll have very little allocation pressure
2101 * on them otherwise.
2102 * It returns -1 if no node is found.
2104 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
2107 int min_val
= INT_MAX
;
2109 node_to_cpumask_ptr(tmp
, 0);
2111 /* Use the local node if we haven't already */
2112 if (!node_isset(node
, *used_node_mask
)) {
2113 node_set(node
, *used_node_mask
);
2117 for_each_node_state(n
, N_HIGH_MEMORY
) {
2119 /* Don't want a node to appear more than once */
2120 if (node_isset(n
, *used_node_mask
))
2123 /* Use the distance array to find the distance */
2124 val
= node_distance(node
, n
);
2126 /* Penalize nodes under us ("prefer the next node") */
2129 /* Give preference to headless and unused nodes */
2130 node_to_cpumask_ptr_next(tmp
, n
);
2131 if (!cpus_empty(*tmp
))
2132 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
2134 /* Slight preference for less loaded node */
2135 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
2136 val
+= node_load
[n
];
2138 if (val
< min_val
) {
2145 node_set(best_node
, *used_node_mask
);
2152 * Build zonelists ordered by node and zones within node.
2153 * This results in maximum locality--normal zone overflows into local
2154 * DMA zone, if any--but risks exhausting DMA zone.
2156 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
2159 struct zonelist
*zonelist
;
2161 zonelist
= &pgdat
->node_zonelists
[0];
2162 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
2164 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2166 zonelist
->_zonerefs
[j
].zone
= NULL
;
2167 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2171 * Build gfp_thisnode zonelists
2173 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
2176 struct zonelist
*zonelist
;
2178 zonelist
= &pgdat
->node_zonelists
[1];
2179 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
2180 zonelist
->_zonerefs
[j
].zone
= NULL
;
2181 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2185 * Build zonelists ordered by zone and nodes within zones.
2186 * This results in conserving DMA zone[s] until all Normal memory is
2187 * exhausted, but results in overflowing to remote node while memory
2188 * may still exist in local DMA zone.
2190 static int node_order
[MAX_NUMNODES
];
2192 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
2195 int zone_type
; /* needs to be signed */
2197 struct zonelist
*zonelist
;
2199 zonelist
= &pgdat
->node_zonelists
[0];
2201 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
2202 for (j
= 0; j
< nr_nodes
; j
++) {
2203 node
= node_order
[j
];
2204 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
2205 if (populated_zone(z
)) {
2207 &zonelist
->_zonerefs
[pos
++]);
2208 check_highest_zone(zone_type
);
2212 zonelist
->_zonerefs
[pos
].zone
= NULL
;
2213 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
2216 static int default_zonelist_order(void)
2219 unsigned long low_kmem_size
,total_size
;
2223 * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem.
2224 * If they are really small and used heavily, the system can fall
2225 * into OOM very easily.
2226 * This function detect ZONE_DMA/DMA32 size and confgigures zone order.
2228 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
2231 for_each_online_node(nid
) {
2232 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2233 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2234 if (populated_zone(z
)) {
2235 if (zone_type
< ZONE_NORMAL
)
2236 low_kmem_size
+= z
->present_pages
;
2237 total_size
+= z
->present_pages
;
2241 if (!low_kmem_size
|| /* there are no DMA area. */
2242 low_kmem_size
> total_size
/2) /* DMA/DMA32 is big. */
2243 return ZONELIST_ORDER_NODE
;
2245 * look into each node's config.
2246 * If there is a node whose DMA/DMA32 memory is very big area on
2247 * local memory, NODE_ORDER may be suitable.
2249 average_size
= total_size
/
2250 (nodes_weight(node_states
[N_HIGH_MEMORY
]) + 1);
2251 for_each_online_node(nid
) {
2254 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2255 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2256 if (populated_zone(z
)) {
2257 if (zone_type
< ZONE_NORMAL
)
2258 low_kmem_size
+= z
->present_pages
;
2259 total_size
+= z
->present_pages
;
2262 if (low_kmem_size
&&
2263 total_size
> average_size
&& /* ignore small node */
2264 low_kmem_size
> total_size
* 70/100)
2265 return ZONELIST_ORDER_NODE
;
2267 return ZONELIST_ORDER_ZONE
;
2270 static void set_zonelist_order(void)
2272 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
2273 current_zonelist_order
= default_zonelist_order();
2275 current_zonelist_order
= user_zonelist_order
;
2278 static void build_zonelists(pg_data_t
*pgdat
)
2282 nodemask_t used_mask
;
2283 int local_node
, prev_node
;
2284 struct zonelist
*zonelist
;
2285 int order
= current_zonelist_order
;
2287 /* initialize zonelists */
2288 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
2289 zonelist
= pgdat
->node_zonelists
+ i
;
2290 zonelist
->_zonerefs
[0].zone
= NULL
;
2291 zonelist
->_zonerefs
[0].zone_idx
= 0;
2294 /* NUMA-aware ordering of nodes */
2295 local_node
= pgdat
->node_id
;
2296 load
= num_online_nodes();
2297 prev_node
= local_node
;
2298 nodes_clear(used_mask
);
2300 memset(node_load
, 0, sizeof(node_load
));
2301 memset(node_order
, 0, sizeof(node_order
));
2304 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
2305 int distance
= node_distance(local_node
, node
);
2308 * If another node is sufficiently far away then it is better
2309 * to reclaim pages in a zone before going off node.
2311 if (distance
> RECLAIM_DISTANCE
)
2312 zone_reclaim_mode
= 1;
2315 * We don't want to pressure a particular node.
2316 * So adding penalty to the first node in same
2317 * distance group to make it round-robin.
2319 if (distance
!= node_distance(local_node
, prev_node
))
2320 node_load
[node
] = load
;
2324 if (order
== ZONELIST_ORDER_NODE
)
2325 build_zonelists_in_node_order(pgdat
, node
);
2327 node_order
[j
++] = node
; /* remember order */
2330 if (order
== ZONELIST_ORDER_ZONE
) {
2331 /* calculate node order -- i.e., DMA last! */
2332 build_zonelists_in_zone_order(pgdat
, j
);
2335 build_thisnode_zonelists(pgdat
);
2338 /* Construct the zonelist performance cache - see further mmzone.h */
2339 static void build_zonelist_cache(pg_data_t
*pgdat
)
2341 struct zonelist
*zonelist
;
2342 struct zonelist_cache
*zlc
;
2345 zonelist
= &pgdat
->node_zonelists
[0];
2346 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
2347 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
2348 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
2349 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
2353 #else /* CONFIG_NUMA */
2355 static void set_zonelist_order(void)
2357 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
2360 static void build_zonelists(pg_data_t
*pgdat
)
2362 int node
, local_node
;
2364 struct zonelist
*zonelist
;
2366 local_node
= pgdat
->node_id
;
2368 zonelist
= &pgdat
->node_zonelists
[0];
2369 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
2372 * Now we build the zonelist so that it contains the zones
2373 * of all the other nodes.
2374 * We don't want to pressure a particular node, so when
2375 * building the zones for node N, we make sure that the
2376 * zones coming right after the local ones are those from
2377 * node N+1 (modulo N)
2379 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
2380 if (!node_online(node
))
2382 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2385 for (node
= 0; node
< local_node
; node
++) {
2386 if (!node_online(node
))
2388 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2392 zonelist
->_zonerefs
[j
].zone
= NULL
;
2393 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2396 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2397 static void build_zonelist_cache(pg_data_t
*pgdat
)
2399 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
2402 #endif /* CONFIG_NUMA */
2404 /* return values int ....just for stop_machine() */
2405 static int __build_all_zonelists(void *dummy
)
2409 for_each_online_node(nid
) {
2410 pg_data_t
*pgdat
= NODE_DATA(nid
);
2412 build_zonelists(pgdat
);
2413 build_zonelist_cache(pgdat
);
2418 void build_all_zonelists(void)
2420 set_zonelist_order();
2422 if (system_state
== SYSTEM_BOOTING
) {
2423 __build_all_zonelists(NULL
);
2424 mminit_verify_zonelist();
2425 cpuset_init_current_mems_allowed();
2427 /* we have to stop all cpus to guarantee there is no user
2429 stop_machine(__build_all_zonelists
, NULL
, NULL
);
2430 /* cpuset refresh routine should be here */
2432 vm_total_pages
= nr_free_pagecache_pages();
2434 * Disable grouping by mobility if the number of pages in the
2435 * system is too low to allow the mechanism to work. It would be
2436 * more accurate, but expensive to check per-zone. This check is
2437 * made on memory-hotadd so a system can start with mobility
2438 * disabled and enable it later
2440 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
2441 page_group_by_mobility_disabled
= 1;
2443 page_group_by_mobility_disabled
= 0;
2445 printk("Built %i zonelists in %s order, mobility grouping %s. "
2446 "Total pages: %ld\n",
2448 zonelist_order_name
[current_zonelist_order
],
2449 page_group_by_mobility_disabled
? "off" : "on",
2452 printk("Policy zone: %s\n", zone_names
[policy_zone
]);
2457 * Helper functions to size the waitqueue hash table.
2458 * Essentially these want to choose hash table sizes sufficiently
2459 * large so that collisions trying to wait on pages are rare.
2460 * But in fact, the number of active page waitqueues on typical
2461 * systems is ridiculously low, less than 200. So this is even
2462 * conservative, even though it seems large.
2464 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
2465 * waitqueues, i.e. the size of the waitq table given the number of pages.
2467 #define PAGES_PER_WAITQUEUE 256
2469 #ifndef CONFIG_MEMORY_HOTPLUG
2470 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
2472 unsigned long size
= 1;
2474 pages
/= PAGES_PER_WAITQUEUE
;
2476 while (size
< pages
)
2480 * Once we have dozens or even hundreds of threads sleeping
2481 * on IO we've got bigger problems than wait queue collision.
2482 * Limit the size of the wait table to a reasonable size.
2484 size
= min(size
, 4096UL);
2486 return max(size
, 4UL);
2490 * A zone's size might be changed by hot-add, so it is not possible to determine
2491 * a suitable size for its wait_table. So we use the maximum size now.
2493 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
2495 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
2496 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
2497 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
2499 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
2500 * or more by the traditional way. (See above). It equals:
2502 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
2503 * ia64(16K page size) : = ( 8G + 4M)byte.
2504 * powerpc (64K page size) : = (32G +16M)byte.
2506 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
2513 * This is an integer logarithm so that shifts can be used later
2514 * to extract the more random high bits from the multiplicative
2515 * hash function before the remainder is taken.
2517 static inline unsigned long wait_table_bits(unsigned long size
)
2522 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
2525 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2526 * of blocks reserved is based on zone->pages_min. The memory within the
2527 * reserve will tend to store contiguous free pages. Setting min_free_kbytes
2528 * higher will lead to a bigger reserve which will get freed as contiguous
2529 * blocks as reclaim kicks in
2531 static void setup_zone_migrate_reserve(struct zone
*zone
)
2533 unsigned long start_pfn
, pfn
, end_pfn
;
2535 unsigned long reserve
, block_migratetype
;
2537 /* Get the start pfn, end pfn and the number of blocks to reserve */
2538 start_pfn
= zone
->zone_start_pfn
;
2539 end_pfn
= start_pfn
+ zone
->spanned_pages
;
2540 reserve
= roundup(zone
->pages_min
, pageblock_nr_pages
) >>
2543 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
2544 if (!pfn_valid(pfn
))
2546 page
= pfn_to_page(pfn
);
2548 /* Watch out for overlapping nodes */
2549 if (page_to_nid(page
) != zone_to_nid(zone
))
2552 /* Blocks with reserved pages will never free, skip them. */
2553 if (PageReserved(page
))
2556 block_migratetype
= get_pageblock_migratetype(page
);
2558 /* If this block is reserved, account for it */
2559 if (reserve
> 0 && block_migratetype
== MIGRATE_RESERVE
) {
2564 /* Suitable for reserving if this block is movable */
2565 if (reserve
> 0 && block_migratetype
== MIGRATE_MOVABLE
) {
2566 set_pageblock_migratetype(page
, MIGRATE_RESERVE
);
2567 move_freepages_block(zone
, page
, MIGRATE_RESERVE
);
2573 * If the reserve is met and this is a previous reserved block,
2576 if (block_migratetype
== MIGRATE_RESERVE
) {
2577 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
2578 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
2584 * Initially all pages are reserved - free ones are freed
2585 * up by free_all_bootmem() once the early boot process is
2586 * done. Non-atomic initialization, single-pass.
2588 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
2589 unsigned long start_pfn
, enum memmap_context context
)
2592 unsigned long end_pfn
= start_pfn
+ size
;
2596 z
= &NODE_DATA(nid
)->node_zones
[zone
];
2597 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
2599 * There can be holes in boot-time mem_map[]s
2600 * handed to this function. They do not
2601 * exist on hotplugged memory.
2603 if (context
== MEMMAP_EARLY
) {
2604 if (!early_pfn_valid(pfn
))
2606 if (!early_pfn_in_nid(pfn
, nid
))
2609 page
= pfn_to_page(pfn
);
2610 set_page_links(page
, zone
, nid
, pfn
);
2611 mminit_verify_page_links(page
, zone
, nid
, pfn
);
2612 init_page_count(page
);
2613 reset_page_mapcount(page
);
2614 SetPageReserved(page
);
2616 * Mark the block movable so that blocks are reserved for
2617 * movable at startup. This will force kernel allocations
2618 * to reserve their blocks rather than leaking throughout
2619 * the address space during boot when many long-lived
2620 * kernel allocations are made. Later some blocks near
2621 * the start are marked MIGRATE_RESERVE by
2622 * setup_zone_migrate_reserve()
2624 * bitmap is created for zone's valid pfn range. but memmap
2625 * can be created for invalid pages (for alignment)
2626 * check here not to call set_pageblock_migratetype() against
2629 if ((z
->zone_start_pfn
<= pfn
)
2630 && (pfn
< z
->zone_start_pfn
+ z
->spanned_pages
)
2631 && !(pfn
& (pageblock_nr_pages
- 1)))
2632 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
2634 INIT_LIST_HEAD(&page
->lru
);
2635 #ifdef WANT_PAGE_VIRTUAL
2636 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
2637 if (!is_highmem_idx(zone
))
2638 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
2643 static void __meminit
zone_init_free_lists(struct zone
*zone
)
2646 for_each_migratetype_order(order
, t
) {
2647 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
2648 zone
->free_area
[order
].nr_free
= 0;
2652 #ifndef __HAVE_ARCH_MEMMAP_INIT
2653 #define memmap_init(size, nid, zone, start_pfn) \
2654 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
2657 static int zone_batchsize(struct zone
*zone
)
2662 * The per-cpu-pages pools are set to around 1000th of the
2663 * size of the zone. But no more than 1/2 of a meg.
2665 * OK, so we don't know how big the cache is. So guess.
2667 batch
= zone
->present_pages
/ 1024;
2668 if (batch
* PAGE_SIZE
> 512 * 1024)
2669 batch
= (512 * 1024) / PAGE_SIZE
;
2670 batch
/= 4; /* We effectively *= 4 below */
2675 * Clamp the batch to a 2^n - 1 value. Having a power
2676 * of 2 value was found to be more likely to have
2677 * suboptimal cache aliasing properties in some cases.
2679 * For example if 2 tasks are alternately allocating
2680 * batches of pages, one task can end up with a lot
2681 * of pages of one half of the possible page colors
2682 * and the other with pages of the other colors.
2684 batch
= (1 << (fls(batch
+ batch
/2)-1)) - 1;
2689 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
2691 struct per_cpu_pages
*pcp
;
2693 memset(p
, 0, sizeof(*p
));
2697 pcp
->high
= 6 * batch
;
2698 pcp
->batch
= max(1UL, 1 * batch
);
2699 INIT_LIST_HEAD(&pcp
->list
);
2703 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
2704 * to the value high for the pageset p.
2707 static void setup_pagelist_highmark(struct per_cpu_pageset
*p
,
2710 struct per_cpu_pages
*pcp
;
2714 pcp
->batch
= max(1UL, high
/4);
2715 if ((high
/4) > (PAGE_SHIFT
* 8))
2716 pcp
->batch
= PAGE_SHIFT
* 8;
2722 * Boot pageset table. One per cpu which is going to be used for all
2723 * zones and all nodes. The parameters will be set in such a way
2724 * that an item put on a list will immediately be handed over to
2725 * the buddy list. This is safe since pageset manipulation is done
2726 * with interrupts disabled.
2728 * Some NUMA counter updates may also be caught by the boot pagesets.
2730 * The boot_pagesets must be kept even after bootup is complete for
2731 * unused processors and/or zones. They do play a role for bootstrapping
2732 * hotplugged processors.
2734 * zoneinfo_show() and maybe other functions do
2735 * not check if the processor is online before following the pageset pointer.
2736 * Other parts of the kernel may not check if the zone is available.
2738 static struct per_cpu_pageset boot_pageset
[NR_CPUS
];
2741 * Dynamically allocate memory for the
2742 * per cpu pageset array in struct zone.
2744 static int __cpuinit
process_zones(int cpu
)
2746 struct zone
*zone
, *dzone
;
2747 int node
= cpu_to_node(cpu
);
2749 node_set_state(node
, N_CPU
); /* this node has a cpu */
2751 for_each_zone(zone
) {
2753 if (!populated_zone(zone
))
2756 zone_pcp(zone
, cpu
) = kmalloc_node(sizeof(struct per_cpu_pageset
),
2758 if (!zone_pcp(zone
, cpu
))
2761 setup_pageset(zone_pcp(zone
, cpu
), zone_batchsize(zone
));
2763 if (percpu_pagelist_fraction
)
2764 setup_pagelist_highmark(zone_pcp(zone
, cpu
),
2765 (zone
->present_pages
/ percpu_pagelist_fraction
));
2770 for_each_zone(dzone
) {
2771 if (!populated_zone(dzone
))
2775 kfree(zone_pcp(dzone
, cpu
));
2776 zone_pcp(dzone
, cpu
) = NULL
;
2781 static inline void free_zone_pagesets(int cpu
)
2785 for_each_zone(zone
) {
2786 struct per_cpu_pageset
*pset
= zone_pcp(zone
, cpu
);
2788 /* Free per_cpu_pageset if it is slab allocated */
2789 if (pset
!= &boot_pageset
[cpu
])
2791 zone_pcp(zone
, cpu
) = NULL
;
2795 static int __cpuinit
pageset_cpuup_callback(struct notifier_block
*nfb
,
2796 unsigned long action
,
2799 int cpu
= (long)hcpu
;
2800 int ret
= NOTIFY_OK
;
2803 case CPU_UP_PREPARE
:
2804 case CPU_UP_PREPARE_FROZEN
:
2805 if (process_zones(cpu
))
2808 case CPU_UP_CANCELED
:
2809 case CPU_UP_CANCELED_FROZEN
:
2811 case CPU_DEAD_FROZEN
:
2812 free_zone_pagesets(cpu
);
2820 static struct notifier_block __cpuinitdata pageset_notifier
=
2821 { &pageset_cpuup_callback
, NULL
, 0 };
2823 void __init
setup_per_cpu_pageset(void)
2827 /* Initialize per_cpu_pageset for cpu 0.
2828 * A cpuup callback will do this for every cpu
2829 * as it comes online
2831 err
= process_zones(smp_processor_id());
2833 register_cpu_notifier(&pageset_notifier
);
2838 static noinline __init_refok
2839 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
2842 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
2846 * The per-page waitqueue mechanism uses hashed waitqueues
2849 zone
->wait_table_hash_nr_entries
=
2850 wait_table_hash_nr_entries(zone_size_pages
);
2851 zone
->wait_table_bits
=
2852 wait_table_bits(zone
->wait_table_hash_nr_entries
);
2853 alloc_size
= zone
->wait_table_hash_nr_entries
2854 * sizeof(wait_queue_head_t
);
2856 if (!slab_is_available()) {
2857 zone
->wait_table
= (wait_queue_head_t
*)
2858 alloc_bootmem_node(pgdat
, alloc_size
);
2861 * This case means that a zone whose size was 0 gets new memory
2862 * via memory hot-add.
2863 * But it may be the case that a new node was hot-added. In
2864 * this case vmalloc() will not be able to use this new node's
2865 * memory - this wait_table must be initialized to use this new
2866 * node itself as well.
2867 * To use this new node's memory, further consideration will be
2870 zone
->wait_table
= vmalloc(alloc_size
);
2872 if (!zone
->wait_table
)
2875 for(i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
2876 init_waitqueue_head(zone
->wait_table
+ i
);
2881 static __meminit
void zone_pcp_init(struct zone
*zone
)
2884 unsigned long batch
= zone_batchsize(zone
);
2886 for (cpu
= 0; cpu
< NR_CPUS
; cpu
++) {
2888 /* Early boot. Slab allocator not functional yet */
2889 zone_pcp(zone
, cpu
) = &boot_pageset
[cpu
];
2890 setup_pageset(&boot_pageset
[cpu
],0);
2892 setup_pageset(zone_pcp(zone
,cpu
), batch
);
2895 if (zone
->present_pages
)
2896 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%lu\n",
2897 zone
->name
, zone
->present_pages
, batch
);
2900 __meminit
int init_currently_empty_zone(struct zone
*zone
,
2901 unsigned long zone_start_pfn
,
2903 enum memmap_context context
)
2905 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
2907 ret
= zone_wait_table_init(zone
, size
);
2910 pgdat
->nr_zones
= zone_idx(zone
) + 1;
2912 zone
->zone_start_pfn
= zone_start_pfn
;
2914 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
2915 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
2917 (unsigned long)zone_idx(zone
),
2918 zone_start_pfn
, (zone_start_pfn
+ size
));
2920 zone_init_free_lists(zone
);
2925 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
2927 * Basic iterator support. Return the first range of PFNs for a node
2928 * Note: nid == MAX_NUMNODES returns first region regardless of node
2930 static int __meminit
first_active_region_index_in_nid(int nid
)
2934 for (i
= 0; i
< nr_nodemap_entries
; i
++)
2935 if (nid
== MAX_NUMNODES
|| early_node_map
[i
].nid
== nid
)
2942 * Basic iterator support. Return the next active range of PFNs for a node
2943 * Note: nid == MAX_NUMNODES returns next region regardless of node
2945 static int __meminit
next_active_region_index_in_nid(int index
, int nid
)
2947 for (index
= index
+ 1; index
< nr_nodemap_entries
; index
++)
2948 if (nid
== MAX_NUMNODES
|| early_node_map
[index
].nid
== nid
)
2954 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
2956 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
2957 * Architectures may implement their own version but if add_active_range()
2958 * was used and there are no special requirements, this is a convenient
2961 int __meminit
early_pfn_to_nid(unsigned long pfn
)
2965 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
2966 unsigned long start_pfn
= early_node_map
[i
].start_pfn
;
2967 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
2969 if (start_pfn
<= pfn
&& pfn
< end_pfn
)
2970 return early_node_map
[i
].nid
;
2975 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
2977 /* Basic iterator support to walk early_node_map[] */
2978 #define for_each_active_range_index_in_nid(i, nid) \
2979 for (i = first_active_region_index_in_nid(nid); i != -1; \
2980 i = next_active_region_index_in_nid(i, nid))
2983 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
2984 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
2985 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
2987 * If an architecture guarantees that all ranges registered with
2988 * add_active_ranges() contain no holes and may be freed, this
2989 * this function may be used instead of calling free_bootmem() manually.
2991 void __init
free_bootmem_with_active_regions(int nid
,
2992 unsigned long max_low_pfn
)
2996 for_each_active_range_index_in_nid(i
, nid
) {
2997 unsigned long size_pages
= 0;
2998 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
3000 if (early_node_map
[i
].start_pfn
>= max_low_pfn
)
3003 if (end_pfn
> max_low_pfn
)
3004 end_pfn
= max_low_pfn
;
3006 size_pages
= end_pfn
- early_node_map
[i
].start_pfn
;
3007 free_bootmem_node(NODE_DATA(early_node_map
[i
].nid
),
3008 PFN_PHYS(early_node_map
[i
].start_pfn
),
3009 size_pages
<< PAGE_SHIFT
);
3013 void __init
work_with_active_regions(int nid
, work_fn_t work_fn
, void *data
)
3018 for_each_active_range_index_in_nid(i
, nid
) {
3019 ret
= work_fn(early_node_map
[i
].start_pfn
,
3020 early_node_map
[i
].end_pfn
, data
);
3026 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3027 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3029 * If an architecture guarantees that all ranges registered with
3030 * add_active_ranges() contain no holes and may be freed, this
3031 * function may be used instead of calling memory_present() manually.
3033 void __init
sparse_memory_present_with_active_regions(int nid
)
3037 for_each_active_range_index_in_nid(i
, nid
)
3038 memory_present(early_node_map
[i
].nid
,
3039 early_node_map
[i
].start_pfn
,
3040 early_node_map
[i
].end_pfn
);
3044 * push_node_boundaries - Push node boundaries to at least the requested boundary
3045 * @nid: The nid of the node to push the boundary for
3046 * @start_pfn: The start pfn of the node
3047 * @end_pfn: The end pfn of the node
3049 * In reserve-based hot-add, mem_map is allocated that is unused until hotadd
3050 * time. Specifically, on x86_64, SRAT will report ranges that can potentially
3051 * be hotplugged even though no physical memory exists. This function allows
3052 * an arch to push out the node boundaries so mem_map is allocated that can
3055 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
3056 void __init
push_node_boundaries(unsigned int nid
,
3057 unsigned long start_pfn
, unsigned long end_pfn
)
3059 mminit_dprintk(MMINIT_TRACE
, "zoneboundary",
3060 "Entering push_node_boundaries(%u, %lu, %lu)\n",
3061 nid
, start_pfn
, end_pfn
);
3063 /* Initialise the boundary for this node if necessary */
3064 if (node_boundary_end_pfn
[nid
] == 0)
3065 node_boundary_start_pfn
[nid
] = -1UL;
3067 /* Update the boundaries */
3068 if (node_boundary_start_pfn
[nid
] > start_pfn
)
3069 node_boundary_start_pfn
[nid
] = start_pfn
;
3070 if (node_boundary_end_pfn
[nid
] < end_pfn
)
3071 node_boundary_end_pfn
[nid
] = end_pfn
;
3074 /* If necessary, push the node boundary out for reserve hotadd */
3075 static void __meminit
account_node_boundary(unsigned int nid
,
3076 unsigned long *start_pfn
, unsigned long *end_pfn
)
3078 mminit_dprintk(MMINIT_TRACE
, "zoneboundary",
3079 "Entering account_node_boundary(%u, %lu, %lu)\n",
3080 nid
, *start_pfn
, *end_pfn
);
3082 /* Return if boundary information has not been provided */
3083 if (node_boundary_end_pfn
[nid
] == 0)
3086 /* Check the boundaries and update if necessary */
3087 if (node_boundary_start_pfn
[nid
] < *start_pfn
)
3088 *start_pfn
= node_boundary_start_pfn
[nid
];
3089 if (node_boundary_end_pfn
[nid
] > *end_pfn
)
3090 *end_pfn
= node_boundary_end_pfn
[nid
];
3093 void __init
push_node_boundaries(unsigned int nid
,
3094 unsigned long start_pfn
, unsigned long end_pfn
) {}
3096 static void __meminit
account_node_boundary(unsigned int nid
,
3097 unsigned long *start_pfn
, unsigned long *end_pfn
) {}
3102 * get_pfn_range_for_nid - Return the start and end page frames for a node
3103 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
3104 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
3105 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
3107 * It returns the start and end page frame of a node based on information
3108 * provided by an arch calling add_active_range(). If called for a node
3109 * with no available memory, a warning is printed and the start and end
3112 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
3113 unsigned long *start_pfn
, unsigned long *end_pfn
)
3119 for_each_active_range_index_in_nid(i
, nid
) {
3120 *start_pfn
= min(*start_pfn
, early_node_map
[i
].start_pfn
);
3121 *end_pfn
= max(*end_pfn
, early_node_map
[i
].end_pfn
);
3124 if (*start_pfn
== -1UL)
3127 /* Push the node boundaries out if requested */
3128 account_node_boundary(nid
, start_pfn
, end_pfn
);
3132 * This finds a zone that can be used for ZONE_MOVABLE pages. The
3133 * assumption is made that zones within a node are ordered in monotonic
3134 * increasing memory addresses so that the "highest" populated zone is used
3136 static void __init
find_usable_zone_for_movable(void)
3139 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
3140 if (zone_index
== ZONE_MOVABLE
)
3143 if (arch_zone_highest_possible_pfn
[zone_index
] >
3144 arch_zone_lowest_possible_pfn
[zone_index
])
3148 VM_BUG_ON(zone_index
== -1);
3149 movable_zone
= zone_index
;
3153 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
3154 * because it is sized independant of architecture. Unlike the other zones,
3155 * the starting point for ZONE_MOVABLE is not fixed. It may be different
3156 * in each node depending on the size of each node and how evenly kernelcore
3157 * is distributed. This helper function adjusts the zone ranges
3158 * provided by the architecture for a given node by using the end of the
3159 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
3160 * zones within a node are in order of monotonic increases memory addresses
3162 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
3163 unsigned long zone_type
,
3164 unsigned long node_start_pfn
,
3165 unsigned long node_end_pfn
,
3166 unsigned long *zone_start_pfn
,
3167 unsigned long *zone_end_pfn
)
3169 /* Only adjust if ZONE_MOVABLE is on this node */
3170 if (zone_movable_pfn
[nid
]) {
3171 /* Size ZONE_MOVABLE */
3172 if (zone_type
== ZONE_MOVABLE
) {
3173 *zone_start_pfn
= zone_movable_pfn
[nid
];
3174 *zone_end_pfn
= min(node_end_pfn
,
3175 arch_zone_highest_possible_pfn
[movable_zone
]);
3177 /* Adjust for ZONE_MOVABLE starting within this range */
3178 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
3179 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
3180 *zone_end_pfn
= zone_movable_pfn
[nid
];
3182 /* Check if this whole range is within ZONE_MOVABLE */
3183 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
3184 *zone_start_pfn
= *zone_end_pfn
;
3189 * Return the number of pages a zone spans in a node, including holes
3190 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
3192 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3193 unsigned long zone_type
,
3194 unsigned long *ignored
)
3196 unsigned long node_start_pfn
, node_end_pfn
;
3197 unsigned long zone_start_pfn
, zone_end_pfn
;
3199 /* Get the start and end of the node and zone */
3200 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3201 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
3202 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
3203 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3204 node_start_pfn
, node_end_pfn
,
3205 &zone_start_pfn
, &zone_end_pfn
);
3207 /* Check that this node has pages within the zone's required range */
3208 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
3211 /* Move the zone boundaries inside the node if necessary */
3212 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
3213 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
3215 /* Return the spanned pages */
3216 return zone_end_pfn
- zone_start_pfn
;
3220 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
3221 * then all holes in the requested range will be accounted for.
3223 static unsigned long __meminit
__absent_pages_in_range(int nid
,
3224 unsigned long range_start_pfn
,
3225 unsigned long range_end_pfn
)
3228 unsigned long prev_end_pfn
= 0, hole_pages
= 0;
3229 unsigned long start_pfn
;
3231 /* Find the end_pfn of the first active range of pfns in the node */
3232 i
= first_active_region_index_in_nid(nid
);
3236 prev_end_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3238 /* Account for ranges before physical memory on this node */
3239 if (early_node_map
[i
].start_pfn
> range_start_pfn
)
3240 hole_pages
= prev_end_pfn
- range_start_pfn
;
3242 /* Find all holes for the zone within the node */
3243 for (; i
!= -1; i
= next_active_region_index_in_nid(i
, nid
)) {
3245 /* No need to continue if prev_end_pfn is outside the zone */
3246 if (prev_end_pfn
>= range_end_pfn
)
3249 /* Make sure the end of the zone is not within the hole */
3250 start_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3251 prev_end_pfn
= max(prev_end_pfn
, range_start_pfn
);
3253 /* Update the hole size cound and move on */
3254 if (start_pfn
> range_start_pfn
) {
3255 BUG_ON(prev_end_pfn
> start_pfn
);
3256 hole_pages
+= start_pfn
- prev_end_pfn
;
3258 prev_end_pfn
= early_node_map
[i
].end_pfn
;
3261 /* Account for ranges past physical memory on this node */
3262 if (range_end_pfn
> prev_end_pfn
)
3263 hole_pages
+= range_end_pfn
-
3264 max(range_start_pfn
, prev_end_pfn
);
3270 * absent_pages_in_range - Return number of page frames in holes within a range
3271 * @start_pfn: The start PFN to start searching for holes
3272 * @end_pfn: The end PFN to stop searching for holes
3274 * It returns the number of pages frames in memory holes within a range.
3276 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
3277 unsigned long end_pfn
)
3279 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
3282 /* Return the number of page frames in holes in a zone on a node */
3283 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
3284 unsigned long zone_type
,
3285 unsigned long *ignored
)
3287 unsigned long node_start_pfn
, node_end_pfn
;
3288 unsigned long zone_start_pfn
, zone_end_pfn
;
3290 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3291 zone_start_pfn
= max(arch_zone_lowest_possible_pfn
[zone_type
],
3293 zone_end_pfn
= min(arch_zone_highest_possible_pfn
[zone_type
],
3296 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3297 node_start_pfn
, node_end_pfn
,
3298 &zone_start_pfn
, &zone_end_pfn
);
3299 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
3303 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3304 unsigned long zone_type
,
3305 unsigned long *zones_size
)
3307 return zones_size
[zone_type
];
3310 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
3311 unsigned long zone_type
,
3312 unsigned long *zholes_size
)
3317 return zholes_size
[zone_type
];
3322 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
3323 unsigned long *zones_size
, unsigned long *zholes_size
)
3325 unsigned long realtotalpages
, totalpages
= 0;
3328 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3329 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
3331 pgdat
->node_spanned_pages
= totalpages
;
3333 realtotalpages
= totalpages
;
3334 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3336 zone_absent_pages_in_node(pgdat
->node_id
, i
,
3338 pgdat
->node_present_pages
= realtotalpages
;
3339 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
3343 #ifndef CONFIG_SPARSEMEM
3345 * Calculate the size of the zone->blockflags rounded to an unsigned long
3346 * Start by making sure zonesize is a multiple of pageblock_order by rounding
3347 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
3348 * round what is now in bits to nearest long in bits, then return it in
3351 static unsigned long __init
usemap_size(unsigned long zonesize
)
3353 unsigned long usemapsize
;
3355 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
3356 usemapsize
= usemapsize
>> pageblock_order
;
3357 usemapsize
*= NR_PAGEBLOCK_BITS
;
3358 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
3360 return usemapsize
/ 8;
3363 static void __init
setup_usemap(struct pglist_data
*pgdat
,
3364 struct zone
*zone
, unsigned long zonesize
)
3366 unsigned long usemapsize
= usemap_size(zonesize
);
3367 zone
->pageblock_flags
= NULL
;
3369 zone
->pageblock_flags
= alloc_bootmem_node(pgdat
, usemapsize
);
3370 memset(zone
->pageblock_flags
, 0, usemapsize
);
3374 static void inline setup_usemap(struct pglist_data
*pgdat
,
3375 struct zone
*zone
, unsigned long zonesize
) {}
3376 #endif /* CONFIG_SPARSEMEM */
3378 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3380 /* Return a sensible default order for the pageblock size. */
3381 static inline int pageblock_default_order(void)
3383 if (HPAGE_SHIFT
> PAGE_SHIFT
)
3384 return HUGETLB_PAGE_ORDER
;
3389 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
3390 static inline void __init
set_pageblock_order(unsigned int order
)
3392 /* Check that pageblock_nr_pages has not already been setup */
3393 if (pageblock_order
)
3397 * Assume the largest contiguous order of interest is a huge page.
3398 * This value may be variable depending on boot parameters on IA64
3400 pageblock_order
= order
;
3402 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3405 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
3406 * and pageblock_default_order() are unused as pageblock_order is set
3407 * at compile-time. See include/linux/pageblock-flags.h for the values of
3408 * pageblock_order based on the kernel config
3410 static inline int pageblock_default_order(unsigned int order
)
3414 #define set_pageblock_order(x) do {} while (0)
3416 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3419 * Set up the zone data structures:
3420 * - mark all pages reserved
3421 * - mark all memory queues empty
3422 * - clear the memory bitmaps
3424 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
,
3425 unsigned long *zones_size
, unsigned long *zholes_size
)
3428 int nid
= pgdat
->node_id
;
3429 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
3432 pgdat_resize_init(pgdat
);
3433 pgdat
->nr_zones
= 0;
3434 init_waitqueue_head(&pgdat
->kswapd_wait
);
3435 pgdat
->kswapd_max_order
= 0;
3437 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
3438 struct zone
*zone
= pgdat
->node_zones
+ j
;
3439 unsigned long size
, realsize
, memmap_pages
;
3442 size
= zone_spanned_pages_in_node(nid
, j
, zones_size
);
3443 realsize
= size
- zone_absent_pages_in_node(nid
, j
,
3447 * Adjust realsize so that it accounts for how much memory
3448 * is used by this zone for memmap. This affects the watermark
3449 * and per-cpu initialisations
3452 PAGE_ALIGN(size
* sizeof(struct page
)) >> PAGE_SHIFT
;
3453 if (realsize
>= memmap_pages
) {
3454 realsize
-= memmap_pages
;
3455 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
3456 "%s zone: %lu pages used for memmap\n",
3457 zone_names
[j
], memmap_pages
);
3460 " %s zone: %lu pages exceeds realsize %lu\n",
3461 zone_names
[j
], memmap_pages
, realsize
);
3463 /* Account for reserved pages */
3464 if (j
== 0 && realsize
> dma_reserve
) {
3465 realsize
-= dma_reserve
;
3466 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
3467 "%s zone: %lu pages reserved\n",
3468 zone_names
[0], dma_reserve
);
3471 if (!is_highmem_idx(j
))
3472 nr_kernel_pages
+= realsize
;
3473 nr_all_pages
+= realsize
;
3475 zone
->spanned_pages
= size
;
3476 zone
->present_pages
= realsize
;
3479 zone
->min_unmapped_pages
= (realsize
*sysctl_min_unmapped_ratio
)
3481 zone
->min_slab_pages
= (realsize
* sysctl_min_slab_ratio
) / 100;
3483 zone
->name
= zone_names
[j
];
3484 spin_lock_init(&zone
->lock
);
3485 spin_lock_init(&zone
->lru_lock
);
3486 zone_seqlock_init(zone
);
3487 zone
->zone_pgdat
= pgdat
;
3489 zone
->prev_priority
= DEF_PRIORITY
;
3491 zone_pcp_init(zone
);
3493 INIT_LIST_HEAD(&zone
->lru
[l
].list
);
3494 zone
->lru
[l
].nr_scan
= 0;
3496 zone
->recent_rotated
[0] = 0;
3497 zone
->recent_rotated
[1] = 0;
3498 zone
->recent_scanned
[0] = 0;
3499 zone
->recent_scanned
[1] = 0;
3500 zap_zone_vm_stats(zone
);
3505 set_pageblock_order(pageblock_default_order());
3506 setup_usemap(pgdat
, zone
, size
);
3507 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
3508 size
, MEMMAP_EARLY
);
3510 memmap_init(size
, nid
, j
, zone_start_pfn
);
3511 zone_start_pfn
+= size
;
3515 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
3517 /* Skip empty nodes */
3518 if (!pgdat
->node_spanned_pages
)
3521 #ifdef CONFIG_FLAT_NODE_MEM_MAP
3522 /* ia64 gets its own node_mem_map, before this, without bootmem */
3523 if (!pgdat
->node_mem_map
) {
3524 unsigned long size
, start
, end
;
3528 * The zone's endpoints aren't required to be MAX_ORDER
3529 * aligned but the node_mem_map endpoints must be in order
3530 * for the buddy allocator to function correctly.
3532 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
3533 end
= pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
3534 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
3535 size
= (end
- start
) * sizeof(struct page
);
3536 map
= alloc_remap(pgdat
->node_id
, size
);
3538 map
= alloc_bootmem_node(pgdat
, size
);
3539 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
3541 #ifndef CONFIG_NEED_MULTIPLE_NODES
3543 * With no DISCONTIG, the global mem_map is just set as node 0's
3545 if (pgdat
== NODE_DATA(0)) {
3546 mem_map
= NODE_DATA(0)->node_mem_map
;
3547 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3548 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
3549 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
3550 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
3553 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
3556 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
3557 unsigned long node_start_pfn
, unsigned long *zholes_size
)
3559 pg_data_t
*pgdat
= NODE_DATA(nid
);
3561 pgdat
->node_id
= nid
;
3562 pgdat
->node_start_pfn
= node_start_pfn
;
3563 calculate_node_totalpages(pgdat
, zones_size
, zholes_size
);
3565 alloc_node_mem_map(pgdat
);
3566 #ifdef CONFIG_FLAT_NODE_MEM_MAP
3567 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
3568 nid
, (unsigned long)pgdat
,
3569 (unsigned long)pgdat
->node_mem_map
);
3572 free_area_init_core(pgdat
, zones_size
, zholes_size
);
3575 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3577 #if MAX_NUMNODES > 1
3579 * Figure out the number of possible node ids.
3581 static void __init
setup_nr_node_ids(void)
3584 unsigned int highest
= 0;
3586 for_each_node_mask(node
, node_possible_map
)
3588 nr_node_ids
= highest
+ 1;
3591 static inline void setup_nr_node_ids(void)
3597 * add_active_range - Register a range of PFNs backed by physical memory
3598 * @nid: The node ID the range resides on
3599 * @start_pfn: The start PFN of the available physical memory
3600 * @end_pfn: The end PFN of the available physical memory
3602 * These ranges are stored in an early_node_map[] and later used by
3603 * free_area_init_nodes() to calculate zone sizes and holes. If the
3604 * range spans a memory hole, it is up to the architecture to ensure
3605 * the memory is not freed by the bootmem allocator. If possible
3606 * the range being registered will be merged with existing ranges.
3608 void __init
add_active_range(unsigned int nid
, unsigned long start_pfn
,
3609 unsigned long end_pfn
)
3613 mminit_dprintk(MMINIT_TRACE
, "memory_register",
3614 "Entering add_active_range(%d, %#lx, %#lx) "
3615 "%d entries of %d used\n",
3616 nid
, start_pfn
, end_pfn
,
3617 nr_nodemap_entries
, MAX_ACTIVE_REGIONS
);
3619 mminit_validate_memmodel_limits(&start_pfn
, &end_pfn
);
3621 /* Merge with existing active regions if possible */
3622 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
3623 if (early_node_map
[i
].nid
!= nid
)
3626 /* Skip if an existing region covers this new one */
3627 if (start_pfn
>= early_node_map
[i
].start_pfn
&&
3628 end_pfn
<= early_node_map
[i
].end_pfn
)
3631 /* Merge forward if suitable */
3632 if (start_pfn
<= early_node_map
[i
].end_pfn
&&
3633 end_pfn
> early_node_map
[i
].end_pfn
) {
3634 early_node_map
[i
].end_pfn
= end_pfn
;
3638 /* Merge backward if suitable */
3639 if (start_pfn
< early_node_map
[i
].end_pfn
&&
3640 end_pfn
>= early_node_map
[i
].start_pfn
) {
3641 early_node_map
[i
].start_pfn
= start_pfn
;
3646 /* Check that early_node_map is large enough */
3647 if (i
>= MAX_ACTIVE_REGIONS
) {
3648 printk(KERN_CRIT
"More than %d memory regions, truncating\n",
3649 MAX_ACTIVE_REGIONS
);
3653 early_node_map
[i
].nid
= nid
;
3654 early_node_map
[i
].start_pfn
= start_pfn
;
3655 early_node_map
[i
].end_pfn
= end_pfn
;
3656 nr_nodemap_entries
= i
+ 1;
3660 * remove_active_range - Shrink an existing registered range of PFNs
3661 * @nid: The node id the range is on that should be shrunk
3662 * @start_pfn: The new PFN of the range
3663 * @end_pfn: The new PFN of the range
3665 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
3666 * The map is kept near the end physical page range that has already been
3667 * registered. This function allows an arch to shrink an existing registered
3670 void __init
remove_active_range(unsigned int nid
, unsigned long start_pfn
,
3671 unsigned long end_pfn
)
3676 printk(KERN_DEBUG
"remove_active_range (%d, %lu, %lu)\n",
3677 nid
, start_pfn
, end_pfn
);
3679 /* Find the old active region end and shrink */
3680 for_each_active_range_index_in_nid(i
, nid
) {
3681 if (early_node_map
[i
].start_pfn
>= start_pfn
&&
3682 early_node_map
[i
].end_pfn
<= end_pfn
) {
3684 early_node_map
[i
].start_pfn
= 0;
3685 early_node_map
[i
].end_pfn
= 0;
3689 if (early_node_map
[i
].start_pfn
< start_pfn
&&
3690 early_node_map
[i
].end_pfn
> start_pfn
) {
3691 unsigned long temp_end_pfn
= early_node_map
[i
].end_pfn
;
3692 early_node_map
[i
].end_pfn
= start_pfn
;
3693 if (temp_end_pfn
> end_pfn
)
3694 add_active_range(nid
, end_pfn
, temp_end_pfn
);
3697 if (early_node_map
[i
].start_pfn
>= start_pfn
&&
3698 early_node_map
[i
].end_pfn
> end_pfn
&&
3699 early_node_map
[i
].start_pfn
< end_pfn
) {
3700 early_node_map
[i
].start_pfn
= end_pfn
;
3708 /* remove the blank ones */
3709 for (i
= nr_nodemap_entries
- 1; i
> 0; i
--) {
3710 if (early_node_map
[i
].nid
!= nid
)
3712 if (early_node_map
[i
].end_pfn
)
3714 /* we found it, get rid of it */
3715 for (j
= i
; j
< nr_nodemap_entries
- 1; j
++)
3716 memcpy(&early_node_map
[j
], &early_node_map
[j
+1],
3717 sizeof(early_node_map
[j
]));
3718 j
= nr_nodemap_entries
- 1;
3719 memset(&early_node_map
[j
], 0, sizeof(early_node_map
[j
]));
3720 nr_nodemap_entries
--;
3725 * remove_all_active_ranges - Remove all currently registered regions
3727 * During discovery, it may be found that a table like SRAT is invalid
3728 * and an alternative discovery method must be used. This function removes
3729 * all currently registered regions.
3731 void __init
remove_all_active_ranges(void)
3733 memset(early_node_map
, 0, sizeof(early_node_map
));
3734 nr_nodemap_entries
= 0;
3735 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
3736 memset(node_boundary_start_pfn
, 0, sizeof(node_boundary_start_pfn
));
3737 memset(node_boundary_end_pfn
, 0, sizeof(node_boundary_end_pfn
));
3738 #endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
3741 /* Compare two active node_active_regions */
3742 static int __init
cmp_node_active_region(const void *a
, const void *b
)
3744 struct node_active_region
*arange
= (struct node_active_region
*)a
;
3745 struct node_active_region
*brange
= (struct node_active_region
*)b
;
3747 /* Done this way to avoid overflows */
3748 if (arange
->start_pfn
> brange
->start_pfn
)
3750 if (arange
->start_pfn
< brange
->start_pfn
)
3756 /* sort the node_map by start_pfn */
3757 static void __init
sort_node_map(void)
3759 sort(early_node_map
, (size_t)nr_nodemap_entries
,
3760 sizeof(struct node_active_region
),
3761 cmp_node_active_region
, NULL
);
3764 /* Find the lowest pfn for a node */
3765 static unsigned long __init
find_min_pfn_for_node(int nid
)
3768 unsigned long min_pfn
= ULONG_MAX
;
3770 /* Assuming a sorted map, the first range found has the starting pfn */
3771 for_each_active_range_index_in_nid(i
, nid
)
3772 min_pfn
= min(min_pfn
, early_node_map
[i
].start_pfn
);
3774 if (min_pfn
== ULONG_MAX
) {
3776 "Could not find start_pfn for node %d\n", nid
);
3784 * find_min_pfn_with_active_regions - Find the minimum PFN registered
3786 * It returns the minimum PFN based on information provided via
3787 * add_active_range().
3789 unsigned long __init
find_min_pfn_with_active_regions(void)
3791 return find_min_pfn_for_node(MAX_NUMNODES
);
3795 * early_calculate_totalpages()
3796 * Sum pages in active regions for movable zone.
3797 * Populate N_HIGH_MEMORY for calculating usable_nodes.
3799 static unsigned long __init
early_calculate_totalpages(void)
3802 unsigned long totalpages
= 0;
3804 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
3805 unsigned long pages
= early_node_map
[i
].end_pfn
-
3806 early_node_map
[i
].start_pfn
;
3807 totalpages
+= pages
;
3809 node_set_state(early_node_map
[i
].nid
, N_HIGH_MEMORY
);
3815 * Find the PFN the Movable zone begins in each node. Kernel memory
3816 * is spread evenly between nodes as long as the nodes have enough
3817 * memory. When they don't, some nodes will have more kernelcore than
3820 static void __init
find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn
)
3823 unsigned long usable_startpfn
;
3824 unsigned long kernelcore_node
, kernelcore_remaining
;
3825 unsigned long totalpages
= early_calculate_totalpages();
3826 int usable_nodes
= nodes_weight(node_states
[N_HIGH_MEMORY
]);
3829 * If movablecore was specified, calculate what size of
3830 * kernelcore that corresponds so that memory usable for
3831 * any allocation type is evenly spread. If both kernelcore
3832 * and movablecore are specified, then the value of kernelcore
3833 * will be used for required_kernelcore if it's greater than
3834 * what movablecore would have allowed.
3836 if (required_movablecore
) {
3837 unsigned long corepages
;
3840 * Round-up so that ZONE_MOVABLE is at least as large as what
3841 * was requested by the user
3843 required_movablecore
=
3844 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
3845 corepages
= totalpages
- required_movablecore
;
3847 required_kernelcore
= max(required_kernelcore
, corepages
);
3850 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
3851 if (!required_kernelcore
)
3854 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
3855 find_usable_zone_for_movable();
3856 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
3859 /* Spread kernelcore memory as evenly as possible throughout nodes */
3860 kernelcore_node
= required_kernelcore
/ usable_nodes
;
3861 for_each_node_state(nid
, N_HIGH_MEMORY
) {
3863 * Recalculate kernelcore_node if the division per node
3864 * now exceeds what is necessary to satisfy the requested
3865 * amount of memory for the kernel
3867 if (required_kernelcore
< kernelcore_node
)
3868 kernelcore_node
= required_kernelcore
/ usable_nodes
;
3871 * As the map is walked, we track how much memory is usable
3872 * by the kernel using kernelcore_remaining. When it is
3873 * 0, the rest of the node is usable by ZONE_MOVABLE
3875 kernelcore_remaining
= kernelcore_node
;
3877 /* Go through each range of PFNs within this node */
3878 for_each_active_range_index_in_nid(i
, nid
) {
3879 unsigned long start_pfn
, end_pfn
;
3880 unsigned long size_pages
;
3882 start_pfn
= max(early_node_map
[i
].start_pfn
,
3883 zone_movable_pfn
[nid
]);
3884 end_pfn
= early_node_map
[i
].end_pfn
;
3885 if (start_pfn
>= end_pfn
)
3888 /* Account for what is only usable for kernelcore */
3889 if (start_pfn
< usable_startpfn
) {
3890 unsigned long kernel_pages
;
3891 kernel_pages
= min(end_pfn
, usable_startpfn
)
3894 kernelcore_remaining
-= min(kernel_pages
,
3895 kernelcore_remaining
);
3896 required_kernelcore
-= min(kernel_pages
,
3897 required_kernelcore
);
3899 /* Continue if range is now fully accounted */
3900 if (end_pfn
<= usable_startpfn
) {
3903 * Push zone_movable_pfn to the end so
3904 * that if we have to rebalance
3905 * kernelcore across nodes, we will
3906 * not double account here
3908 zone_movable_pfn
[nid
] = end_pfn
;
3911 start_pfn
= usable_startpfn
;
3915 * The usable PFN range for ZONE_MOVABLE is from
3916 * start_pfn->end_pfn. Calculate size_pages as the
3917 * number of pages used as kernelcore
3919 size_pages
= end_pfn
- start_pfn
;
3920 if (size_pages
> kernelcore_remaining
)
3921 size_pages
= kernelcore_remaining
;
3922 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
3925 * Some kernelcore has been met, update counts and
3926 * break if the kernelcore for this node has been
3929 required_kernelcore
-= min(required_kernelcore
,
3931 kernelcore_remaining
-= size_pages
;
3932 if (!kernelcore_remaining
)
3938 * If there is still required_kernelcore, we do another pass with one
3939 * less node in the count. This will push zone_movable_pfn[nid] further
3940 * along on the nodes that still have memory until kernelcore is
3944 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
3947 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
3948 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
3949 zone_movable_pfn
[nid
] =
3950 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
3953 /* Any regular memory on that node ? */
3954 static void check_for_regular_memory(pg_data_t
*pgdat
)
3956 #ifdef CONFIG_HIGHMEM
3957 enum zone_type zone_type
;
3959 for (zone_type
= 0; zone_type
<= ZONE_NORMAL
; zone_type
++) {
3960 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
3961 if (zone
->present_pages
)
3962 node_set_state(zone_to_nid(zone
), N_NORMAL_MEMORY
);
3968 * free_area_init_nodes - Initialise all pg_data_t and zone data
3969 * @max_zone_pfn: an array of max PFNs for each zone
3971 * This will call free_area_init_node() for each active node in the system.
3972 * Using the page ranges provided by add_active_range(), the size of each
3973 * zone in each node and their holes is calculated. If the maximum PFN
3974 * between two adjacent zones match, it is assumed that the zone is empty.
3975 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
3976 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
3977 * starts where the previous one ended. For example, ZONE_DMA32 starts
3978 * at arch_max_dma_pfn.
3980 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
3985 /* Sort early_node_map as initialisation assumes it is sorted */
3988 /* Record where the zone boundaries are */
3989 memset(arch_zone_lowest_possible_pfn
, 0,
3990 sizeof(arch_zone_lowest_possible_pfn
));
3991 memset(arch_zone_highest_possible_pfn
, 0,
3992 sizeof(arch_zone_highest_possible_pfn
));
3993 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
3994 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
3995 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
3996 if (i
== ZONE_MOVABLE
)
3998 arch_zone_lowest_possible_pfn
[i
] =
3999 arch_zone_highest_possible_pfn
[i
-1];
4000 arch_zone_highest_possible_pfn
[i
] =
4001 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
4003 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
4004 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
4006 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
4007 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
4008 find_zone_movable_pfns_for_nodes(zone_movable_pfn
);
4010 /* Print out the zone ranges */
4011 printk("Zone PFN ranges:\n");
4012 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4013 if (i
== ZONE_MOVABLE
)
4015 printk(" %-8s %0#10lx -> %0#10lx\n",
4017 arch_zone_lowest_possible_pfn
[i
],
4018 arch_zone_highest_possible_pfn
[i
]);
4021 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
4022 printk("Movable zone start PFN for each node\n");
4023 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
4024 if (zone_movable_pfn
[i
])
4025 printk(" Node %d: %lu\n", i
, zone_movable_pfn
[i
]);
4028 /* Print out the early_node_map[] */
4029 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries
);
4030 for (i
= 0; i
< nr_nodemap_entries
; i
++)
4031 printk(" %3d: %0#10lx -> %0#10lx\n", early_node_map
[i
].nid
,
4032 early_node_map
[i
].start_pfn
,
4033 early_node_map
[i
].end_pfn
);
4035 /* Initialise every node */
4036 mminit_verify_pageflags_layout();
4037 setup_nr_node_ids();
4038 for_each_online_node(nid
) {
4039 pg_data_t
*pgdat
= NODE_DATA(nid
);
4040 free_area_init_node(nid
, NULL
,
4041 find_min_pfn_for_node(nid
), NULL
);
4043 /* Any memory on that node */
4044 if (pgdat
->node_present_pages
)
4045 node_set_state(nid
, N_HIGH_MEMORY
);
4046 check_for_regular_memory(pgdat
);
4050 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
4052 unsigned long long coremem
;
4056 coremem
= memparse(p
, &p
);
4057 *core
= coremem
>> PAGE_SHIFT
;
4059 /* Paranoid check that UL is enough for the coremem value */
4060 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
4066 * kernelcore=size sets the amount of memory for use for allocations that
4067 * cannot be reclaimed or migrated.
4069 static int __init
cmdline_parse_kernelcore(char *p
)
4071 return cmdline_parse_core(p
, &required_kernelcore
);
4075 * movablecore=size sets the amount of memory for use for allocations that
4076 * can be reclaimed or migrated.
4078 static int __init
cmdline_parse_movablecore(char *p
)
4080 return cmdline_parse_core(p
, &required_movablecore
);
4083 early_param("kernelcore", cmdline_parse_kernelcore
);
4084 early_param("movablecore", cmdline_parse_movablecore
);
4086 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
4089 * set_dma_reserve - set the specified number of pages reserved in the first zone
4090 * @new_dma_reserve: The number of pages to mark reserved
4092 * The per-cpu batchsize and zone watermarks are determined by present_pages.
4093 * In the DMA zone, a significant percentage may be consumed by kernel image
4094 * and other unfreeable allocations which can skew the watermarks badly. This
4095 * function may optionally be used to account for unfreeable pages in the
4096 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
4097 * smaller per-cpu batchsize.
4099 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
4101 dma_reserve
= new_dma_reserve
;
4104 #ifndef CONFIG_NEED_MULTIPLE_NODES
4105 struct pglist_data __refdata contig_page_data
= { .bdata
= &bootmem_node_data
[0] };
4106 EXPORT_SYMBOL(contig_page_data
);
4109 void __init
free_area_init(unsigned long *zones_size
)
4111 free_area_init_node(0, zones_size
,
4112 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
4115 static int page_alloc_cpu_notify(struct notifier_block
*self
,
4116 unsigned long action
, void *hcpu
)
4118 int cpu
= (unsigned long)hcpu
;
4120 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
4124 * Spill the event counters of the dead processor
4125 * into the current processors event counters.
4126 * This artificially elevates the count of the current
4129 vm_events_fold_cpu(cpu
);
4132 * Zero the differential counters of the dead processor
4133 * so that the vm statistics are consistent.
4135 * This is only okay since the processor is dead and cannot
4136 * race with what we are doing.
4138 refresh_cpu_vm_stats(cpu
);
4143 void __init
page_alloc_init(void)
4145 hotcpu_notifier(page_alloc_cpu_notify
, 0);
4149 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
4150 * or min_free_kbytes changes.
4152 static void calculate_totalreserve_pages(void)
4154 struct pglist_data
*pgdat
;
4155 unsigned long reserve_pages
= 0;
4156 enum zone_type i
, j
;
4158 for_each_online_pgdat(pgdat
) {
4159 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4160 struct zone
*zone
= pgdat
->node_zones
+ i
;
4161 unsigned long max
= 0;
4163 /* Find valid and maximum lowmem_reserve in the zone */
4164 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
4165 if (zone
->lowmem_reserve
[j
] > max
)
4166 max
= zone
->lowmem_reserve
[j
];
4169 /* we treat pages_high as reserved pages. */
4170 max
+= zone
->pages_high
;
4172 if (max
> zone
->present_pages
)
4173 max
= zone
->present_pages
;
4174 reserve_pages
+= max
;
4177 totalreserve_pages
= reserve_pages
;
4181 * setup_per_zone_lowmem_reserve - called whenever
4182 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
4183 * has a correct pages reserved value, so an adequate number of
4184 * pages are left in the zone after a successful __alloc_pages().
4186 static void setup_per_zone_lowmem_reserve(void)
4188 struct pglist_data
*pgdat
;
4189 enum zone_type j
, idx
;
4191 for_each_online_pgdat(pgdat
) {
4192 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4193 struct zone
*zone
= pgdat
->node_zones
+ j
;
4194 unsigned long present_pages
= zone
->present_pages
;
4196 zone
->lowmem_reserve
[j
] = 0;
4200 struct zone
*lower_zone
;
4204 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
4205 sysctl_lowmem_reserve_ratio
[idx
] = 1;
4207 lower_zone
= pgdat
->node_zones
+ idx
;
4208 lower_zone
->lowmem_reserve
[j
] = present_pages
/
4209 sysctl_lowmem_reserve_ratio
[idx
];
4210 present_pages
+= lower_zone
->present_pages
;
4215 /* update totalreserve_pages */
4216 calculate_totalreserve_pages();
4220 * setup_per_zone_pages_min - called when min_free_kbytes changes.
4222 * Ensures that the pages_{min,low,high} values for each zone are set correctly
4223 * with respect to min_free_kbytes.
4225 void setup_per_zone_pages_min(void)
4227 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
4228 unsigned long lowmem_pages
= 0;
4230 unsigned long flags
;
4232 /* Calculate total number of !ZONE_HIGHMEM pages */
4233 for_each_zone(zone
) {
4234 if (!is_highmem(zone
))
4235 lowmem_pages
+= zone
->present_pages
;
4238 for_each_zone(zone
) {
4241 spin_lock_irqsave(&zone
->lru_lock
, flags
);
4242 tmp
= (u64
)pages_min
* zone
->present_pages
;
4243 do_div(tmp
, lowmem_pages
);
4244 if (is_highmem(zone
)) {
4246 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
4247 * need highmem pages, so cap pages_min to a small
4250 * The (pages_high-pages_low) and (pages_low-pages_min)
4251 * deltas controls asynch page reclaim, and so should
4252 * not be capped for highmem.
4256 min_pages
= zone
->present_pages
/ 1024;
4257 if (min_pages
< SWAP_CLUSTER_MAX
)
4258 min_pages
= SWAP_CLUSTER_MAX
;
4259 if (min_pages
> 128)
4261 zone
->pages_min
= min_pages
;
4264 * If it's a lowmem zone, reserve a number of pages
4265 * proportionate to the zone's size.
4267 zone
->pages_min
= tmp
;
4270 zone
->pages_low
= zone
->pages_min
+ (tmp
>> 2);
4271 zone
->pages_high
= zone
->pages_min
+ (tmp
>> 1);
4272 setup_zone_migrate_reserve(zone
);
4273 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
4276 /* update totalreserve_pages */
4277 calculate_totalreserve_pages();
4281 * setup_per_zone_inactive_ratio - called when min_free_kbytes changes.
4283 * The inactive anon list should be small enough that the VM never has to
4284 * do too much work, but large enough that each inactive page has a chance
4285 * to be referenced again before it is swapped out.
4287 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
4288 * INACTIVE_ANON pages on this zone's LRU, maintained by the
4289 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
4290 * the anonymous pages are kept on the inactive list.
4293 * memory ratio inactive anon
4294 * -------------------------------------
4303 void setup_per_zone_inactive_ratio(void)
4307 for_each_zone(zone
) {
4308 unsigned int gb
, ratio
;
4310 /* Zone size in gigabytes */
4311 gb
= zone
->present_pages
>> (30 - PAGE_SHIFT
);
4312 ratio
= int_sqrt(10 * gb
);
4316 zone
->inactive_ratio
= ratio
;
4321 * Initialise min_free_kbytes.
4323 * For small machines we want it small (128k min). For large machines
4324 * we want it large (64MB max). But it is not linear, because network
4325 * bandwidth does not increase linearly with machine size. We use
4327 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
4328 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
4344 static int __init
init_per_zone_pages_min(void)
4346 unsigned long lowmem_kbytes
;
4348 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
4350 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
4351 if (min_free_kbytes
< 128)
4352 min_free_kbytes
= 128;
4353 if (min_free_kbytes
> 65536)
4354 min_free_kbytes
= 65536;
4355 setup_per_zone_pages_min();
4356 setup_per_zone_lowmem_reserve();
4357 setup_per_zone_inactive_ratio();
4360 module_init(init_per_zone_pages_min
)
4363 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
4364 * that we can call two helper functions whenever min_free_kbytes
4367 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
4368 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4370 proc_dointvec(table
, write
, file
, buffer
, length
, ppos
);
4372 setup_per_zone_pages_min();
4377 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
4378 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4383 rc
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4388 zone
->min_unmapped_pages
= (zone
->present_pages
*
4389 sysctl_min_unmapped_ratio
) / 100;
4393 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
4394 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4399 rc
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4404 zone
->min_slab_pages
= (zone
->present_pages
*
4405 sysctl_min_slab_ratio
) / 100;
4411 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
4412 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
4413 * whenever sysctl_lowmem_reserve_ratio changes.
4415 * The reserve ratio obviously has absolutely no relation with the
4416 * pages_min watermarks. The lowmem reserve ratio can only make sense
4417 * if in function of the boot time zone sizes.
4419 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
4420 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4422 proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4423 setup_per_zone_lowmem_reserve();
4428 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
4429 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
4430 * can have before it gets flushed back to buddy allocator.
4433 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
4434 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
4440 ret
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
4441 if (!write
|| (ret
== -EINVAL
))
4443 for_each_zone(zone
) {
4444 for_each_online_cpu(cpu
) {
4446 high
= zone
->present_pages
/ percpu_pagelist_fraction
;
4447 setup_pagelist_highmark(zone_pcp(zone
, cpu
), high
);
4453 int hashdist
= HASHDIST_DEFAULT
;
4456 static int __init
set_hashdist(char *str
)
4460 hashdist
= simple_strtoul(str
, &str
, 0);
4463 __setup("hashdist=", set_hashdist
);
4467 * allocate a large system hash table from bootmem
4468 * - it is assumed that the hash table must contain an exact power-of-2
4469 * quantity of entries
4470 * - limit is the number of hash buckets, not the total allocation size
4472 void *__init
alloc_large_system_hash(const char *tablename
,
4473 unsigned long bucketsize
,
4474 unsigned long numentries
,
4477 unsigned int *_hash_shift
,
4478 unsigned int *_hash_mask
,
4479 unsigned long limit
)
4481 unsigned long long max
= limit
;
4482 unsigned long log2qty
, size
;
4485 /* allow the kernel cmdline to have a say */
4487 /* round applicable memory size up to nearest megabyte */
4488 numentries
= nr_kernel_pages
;
4489 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
4490 numentries
>>= 20 - PAGE_SHIFT
;
4491 numentries
<<= 20 - PAGE_SHIFT
;
4493 /* limit to 1 bucket per 2^scale bytes of low memory */
4494 if (scale
> PAGE_SHIFT
)
4495 numentries
>>= (scale
- PAGE_SHIFT
);
4497 numentries
<<= (PAGE_SHIFT
- scale
);
4499 /* Make sure we've got at least a 0-order allocation.. */
4500 if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
4501 numentries
= PAGE_SIZE
/ bucketsize
;
4503 numentries
= roundup_pow_of_two(numentries
);
4505 /* limit allocation size to 1/16 total memory by default */
4507 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
4508 do_div(max
, bucketsize
);
4511 if (numentries
> max
)
4514 log2qty
= ilog2(numentries
);
4517 size
= bucketsize
<< log2qty
;
4518 if (flags
& HASH_EARLY
)
4519 table
= alloc_bootmem_nopanic(size
);
4521 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
4523 unsigned long order
= get_order(size
);
4524 table
= (void*) __get_free_pages(GFP_ATOMIC
, order
);
4526 * If bucketsize is not a power-of-two, we may free
4527 * some pages at the end of hash table.
4530 unsigned long alloc_end
= (unsigned long)table
+
4531 (PAGE_SIZE
<< order
);
4532 unsigned long used
= (unsigned long)table
+
4534 split_page(virt_to_page(table
), order
);
4535 while (used
< alloc_end
) {
4541 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
4544 panic("Failed to allocate %s hash table\n", tablename
);
4546 printk(KERN_INFO
"%s hash table entries: %d (order: %d, %lu bytes)\n",
4549 ilog2(size
) - PAGE_SHIFT
,
4553 *_hash_shift
= log2qty
;
4555 *_hash_mask
= (1 << log2qty
) - 1;
4560 #ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
4561 struct page
*pfn_to_page(unsigned long pfn
)
4563 return __pfn_to_page(pfn
);
4565 unsigned long page_to_pfn(struct page
*page
)
4567 return __page_to_pfn(page
);
4569 EXPORT_SYMBOL(pfn_to_page
);
4570 EXPORT_SYMBOL(page_to_pfn
);
4571 #endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */
4573 /* Return a pointer to the bitmap storing bits affecting a block of pages */
4574 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
4577 #ifdef CONFIG_SPARSEMEM
4578 return __pfn_to_section(pfn
)->pageblock_flags
;
4580 return zone
->pageblock_flags
;
4581 #endif /* CONFIG_SPARSEMEM */
4584 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
4586 #ifdef CONFIG_SPARSEMEM
4587 pfn
&= (PAGES_PER_SECTION
-1);
4588 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
4590 pfn
= pfn
- zone
->zone_start_pfn
;
4591 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
4592 #endif /* CONFIG_SPARSEMEM */
4596 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4597 * @page: The page within the block of interest
4598 * @start_bitidx: The first bit of interest to retrieve
4599 * @end_bitidx: The last bit of interest
4600 * returns pageblock_bits flags
4602 unsigned long get_pageblock_flags_group(struct page
*page
,
4603 int start_bitidx
, int end_bitidx
)
4606 unsigned long *bitmap
;
4607 unsigned long pfn
, bitidx
;
4608 unsigned long flags
= 0;
4609 unsigned long value
= 1;
4611 zone
= page_zone(page
);
4612 pfn
= page_to_pfn(page
);
4613 bitmap
= get_pageblock_bitmap(zone
, pfn
);
4614 bitidx
= pfn_to_bitidx(zone
, pfn
);
4616 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
4617 if (test_bit(bitidx
+ start_bitidx
, bitmap
))
4624 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
4625 * @page: The page within the block of interest
4626 * @start_bitidx: The first bit of interest
4627 * @end_bitidx: The last bit of interest
4628 * @flags: The flags to set
4630 void set_pageblock_flags_group(struct page
*page
, unsigned long flags
,
4631 int start_bitidx
, int end_bitidx
)
4634 unsigned long *bitmap
;
4635 unsigned long pfn
, bitidx
;
4636 unsigned long value
= 1;
4638 zone
= page_zone(page
);
4639 pfn
= page_to_pfn(page
);
4640 bitmap
= get_pageblock_bitmap(zone
, pfn
);
4641 bitidx
= pfn_to_bitidx(zone
, pfn
);
4642 VM_BUG_ON(pfn
< zone
->zone_start_pfn
);
4643 VM_BUG_ON(pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
);
4645 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
4647 __set_bit(bitidx
+ start_bitidx
, bitmap
);
4649 __clear_bit(bitidx
+ start_bitidx
, bitmap
);
4653 * This is designed as sub function...plz see page_isolation.c also.
4654 * set/clear page block's type to be ISOLATE.
4655 * page allocater never alloc memory from ISOLATE block.
4658 int set_migratetype_isolate(struct page
*page
)
4661 unsigned long flags
;
4664 zone
= page_zone(page
);
4665 spin_lock_irqsave(&zone
->lock
, flags
);
4667 * In future, more migrate types will be able to be isolation target.
4669 if (get_pageblock_migratetype(page
) != MIGRATE_MOVABLE
)
4671 set_pageblock_migratetype(page
, MIGRATE_ISOLATE
);
4672 move_freepages_block(zone
, page
, MIGRATE_ISOLATE
);
4675 spin_unlock_irqrestore(&zone
->lock
, flags
);
4681 void unset_migratetype_isolate(struct page
*page
)
4684 unsigned long flags
;
4685 zone
= page_zone(page
);
4686 spin_lock_irqsave(&zone
->lock
, flags
);
4687 if (get_pageblock_migratetype(page
) != MIGRATE_ISOLATE
)
4689 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4690 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
4692 spin_unlock_irqrestore(&zone
->lock
, flags
);
4695 #ifdef CONFIG_MEMORY_HOTREMOVE
4697 * All pages in the range must be isolated before calling this.
4700 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
4706 unsigned long flags
;
4707 /* find the first valid pfn */
4708 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
4713 zone
= page_zone(pfn_to_page(pfn
));
4714 spin_lock_irqsave(&zone
->lock
, flags
);
4716 while (pfn
< end_pfn
) {
4717 if (!pfn_valid(pfn
)) {
4721 page
= pfn_to_page(pfn
);
4722 BUG_ON(page_count(page
));
4723 BUG_ON(!PageBuddy(page
));
4724 order
= page_order(page
);
4725 #ifdef CONFIG_DEBUG_VM
4726 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
4727 pfn
, 1 << order
, end_pfn
);
4729 list_del(&page
->lru
);
4730 rmv_page_order(page
);
4731 zone
->free_area
[order
].nr_free
--;
4732 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
4734 for (i
= 0; i
< (1 << order
); i
++)
4735 SetPageReserved((page
+i
));
4736 pfn
+= (1 << order
);
4738 spin_unlock_irqrestore(&zone
->lock
, flags
);