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/config.h>
18 #include <linux/stddef.h>
20 #include <linux/swap.h>
21 #include <linux/interrupt.h>
22 #include <linux/pagemap.h>
23 #include <linux/bootmem.h>
24 #include <linux/compiler.h>
25 #include <linux/module.h>
26 #include <linux/suspend.h>
27 #include <linux/pagevec.h>
28 #include <linux/blkdev.h>
29 #include <linux/slab.h>
30 #include <linux/notifier.h>
31 #include <linux/topology.h>
32 #include <linux/sysctl.h>
33 #include <linux/cpu.h>
34 #include <linux/cpuset.h>
35 #include <linux/nodemask.h>
36 #include <linux/vmalloc.h>
38 #include <asm/tlbflush.h>
42 * MCD - HACK: Find somewhere to initialize this EARLY, or make this
45 nodemask_t node_online_map
= { { [0] = 1UL } };
46 EXPORT_SYMBOL(node_online_map
);
47 nodemask_t node_possible_map
= NODE_MASK_ALL
;
48 EXPORT_SYMBOL(node_possible_map
);
49 struct pglist_data
*pgdat_list
;
50 unsigned long totalram_pages
;
51 unsigned long totalhigh_pages
;
55 * results with 256, 32 in the lowmem_reserve sysctl:
56 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
57 * 1G machine -> (16M dma, 784M normal, 224M high)
58 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
59 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
60 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
62 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = { 256, 32 };
64 EXPORT_SYMBOL(totalram_pages
);
65 EXPORT_SYMBOL(nr_swap_pages
);
68 * Used by page_zone() to look up the address of the struct zone whose
69 * id is encoded in the upper bits of page->flags
71 struct zone
*zone_table
[1 << (ZONES_SHIFT
+ NODES_SHIFT
)];
72 EXPORT_SYMBOL(zone_table
);
75 static struct per_cpu_pageset
76 pageset_table
[MAX_NR_ZONES
*MAX_NUMNODES
*NR_CPUS
] __initdata
;
79 static char *zone_names
[MAX_NR_ZONES
] = { "DMA", "Normal", "HighMem" };
80 int min_free_kbytes
= 1024;
82 unsigned long __initdata nr_kernel_pages
;
83 unsigned long __initdata nr_all_pages
;
86 * Temporary debugging check for pages not lying within a given zone.
88 static int bad_range(struct zone
*zone
, struct page
*page
)
90 if (page_to_pfn(page
) >= zone
->zone_start_pfn
+ zone
->spanned_pages
)
92 if (page_to_pfn(page
) < zone
->zone_start_pfn
)
94 #ifdef CONFIG_HOLES_IN_ZONE
95 if (!pfn_valid(page_to_pfn(page
)))
98 if (zone
!= page_zone(page
))
103 static void bad_page(const char *function
, struct page
*page
)
105 printk(KERN_EMERG
"Bad page state at %s (in process '%s', page %p)\n",
106 function
, current
->comm
, page
);
107 printk(KERN_EMERG
"flags:0x%0*lx mapping:%p mapcount:%d count:%d\n",
108 (int)(2*sizeof(page_flags_t
)), (unsigned long)page
->flags
,
109 page
->mapping
, page_mapcount(page
), page_count(page
));
110 printk(KERN_EMERG
"Backtrace:\n");
112 printk(KERN_EMERG
"Trying to fix it up, but a reboot is needed\n");
113 page
->flags
&= ~(1 << PG_private
|
120 set_page_count(page
, 0);
121 reset_page_mapcount(page
);
122 page
->mapping
= NULL
;
123 tainted
|= TAINT_BAD_PAGE
;
126 #ifndef CONFIG_HUGETLB_PAGE
127 #define prep_compound_page(page, order) do { } while (0)
128 #define destroy_compound_page(page, order) do { } while (0)
131 * Higher-order pages are called "compound pages". They are structured thusly:
133 * The first PAGE_SIZE page is called the "head page".
135 * The remaining PAGE_SIZE pages are called "tail pages".
137 * All pages have PG_compound set. All pages have their ->private pointing at
138 * the head page (even the head page has this).
140 * The first tail page's ->mapping, if non-zero, holds the address of the
141 * compound page's put_page() function.
143 * The order of the allocation is stored in the first tail page's ->index
144 * This is only for debug at present. This usage means that zero-order pages
145 * may not be compound.
147 static void prep_compound_page(struct page
*page
, unsigned long order
)
150 int nr_pages
= 1 << order
;
152 page
[1].mapping
= NULL
;
153 page
[1].index
= order
;
154 for (i
= 0; i
< nr_pages
; i
++) {
155 struct page
*p
= page
+ i
;
158 p
->private = (unsigned long)page
;
162 static void destroy_compound_page(struct page
*page
, unsigned long order
)
165 int nr_pages
= 1 << order
;
167 if (!PageCompound(page
))
170 if (page
[1].index
!= order
)
171 bad_page(__FUNCTION__
, page
);
173 for (i
= 0; i
< nr_pages
; i
++) {
174 struct page
*p
= page
+ i
;
176 if (!PageCompound(p
))
177 bad_page(__FUNCTION__
, page
);
178 if (p
->private != (unsigned long)page
)
179 bad_page(__FUNCTION__
, page
);
180 ClearPageCompound(p
);
183 #endif /* CONFIG_HUGETLB_PAGE */
186 * function for dealing with page's order in buddy system.
187 * zone->lock is already acquired when we use these.
188 * So, we don't need atomic page->flags operations here.
190 static inline unsigned long page_order(struct page
*page
) {
191 return page
->private;
194 static inline void set_page_order(struct page
*page
, int order
) {
195 page
->private = order
;
196 __SetPagePrivate(page
);
199 static inline void rmv_page_order(struct page
*page
)
201 __ClearPagePrivate(page
);
206 * Locate the struct page for both the matching buddy in our
207 * pair (buddy1) and the combined O(n+1) page they form (page).
209 * 1) Any buddy B1 will have an order O twin B2 which satisfies
210 * the following equation:
212 * For example, if the starting buddy (buddy2) is #8 its order
214 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
216 * 2) Any buddy B will have an order O+1 parent P which
217 * satisfies the following equation:
220 * Assumption: *_mem_map is contigious at least up to MAX_ORDER
222 static inline struct page
*
223 __page_find_buddy(struct page
*page
, unsigned long page_idx
, unsigned int order
)
225 unsigned long buddy_idx
= page_idx
^ (1 << order
);
227 return page
+ (buddy_idx
- page_idx
);
230 static inline unsigned long
231 __find_combined_index(unsigned long page_idx
, unsigned int order
)
233 return (page_idx
& ~(1 << order
));
237 * This function checks whether a page is free && is the buddy
238 * we can do coalesce a page and its buddy if
239 * (a) the buddy is free &&
240 * (b) the buddy is on the buddy system &&
241 * (c) a page and its buddy have the same order.
242 * for recording page's order, we use page->private and PG_private.
245 static inline int page_is_buddy(struct page
*page
, int order
)
247 if (PagePrivate(page
) &&
248 (page_order(page
) == order
) &&
249 !PageReserved(page
) &&
250 page_count(page
) == 0)
256 * Freeing function for a buddy system allocator.
258 * The concept of a buddy system is to maintain direct-mapped table
259 * (containing bit values) for memory blocks of various "orders".
260 * The bottom level table contains the map for the smallest allocatable
261 * units of memory (here, pages), and each level above it describes
262 * pairs of units from the levels below, hence, "buddies".
263 * At a high level, all that happens here is marking the table entry
264 * at the bottom level available, and propagating the changes upward
265 * as necessary, plus some accounting needed to play nicely with other
266 * parts of the VM system.
267 * At each level, we keep a list of pages, which are heads of continuous
268 * free pages of length of (1 << order) and marked with PG_Private.Page's
269 * order is recorded in page->private field.
270 * So when we are allocating or freeing one, we can derive the state of the
271 * other. That is, if we allocate a small block, and both were
272 * free, the remainder of the region must be split into blocks.
273 * If a block is freed, and its buddy is also free, then this
274 * triggers coalescing into a block of larger size.
279 static inline void __free_pages_bulk (struct page
*page
,
280 struct zone
*zone
, unsigned int order
)
282 unsigned long page_idx
;
283 int order_size
= 1 << order
;
286 destroy_compound_page(page
, order
);
288 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
290 BUG_ON(page_idx
& (order_size
- 1));
291 BUG_ON(bad_range(zone
, page
));
293 zone
->free_pages
+= order_size
;
294 while (order
< MAX_ORDER
-1) {
295 unsigned long combined_idx
;
296 struct free_area
*area
;
299 combined_idx
= __find_combined_index(page_idx
, order
);
300 buddy
= __page_find_buddy(page
, page_idx
, order
);
302 if (bad_range(zone
, buddy
))
304 if (!page_is_buddy(buddy
, order
))
305 break; /* Move the buddy up one level. */
306 list_del(&buddy
->lru
);
307 area
= zone
->free_area
+ order
;
309 rmv_page_order(buddy
);
310 page
= page
+ (combined_idx
- page_idx
);
311 page_idx
= combined_idx
;
314 set_page_order(page
, order
);
315 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
);
316 zone
->free_area
[order
].nr_free
++;
319 static inline void free_pages_check(const char *function
, struct page
*page
)
321 if ( page_mapcount(page
) ||
322 page
->mapping
!= NULL
||
323 page_count(page
) != 0 ||
332 1 << PG_writeback
)))
333 bad_page(function
, page
);
335 ClearPageDirty(page
);
339 * Frees a list of pages.
340 * Assumes all pages on list are in same zone, and of same order.
341 * count is the number of pages to free, or 0 for all on the list.
343 * If the zone was previously in an "all pages pinned" state then look to
344 * see if this freeing clears that state.
346 * And clear the zone's pages_scanned counter, to hold off the "all pages are
347 * pinned" detection logic.
350 free_pages_bulk(struct zone
*zone
, int count
,
351 struct list_head
*list
, unsigned int order
)
354 struct page
*page
= NULL
;
357 spin_lock_irqsave(&zone
->lock
, flags
);
358 zone
->all_unreclaimable
= 0;
359 zone
->pages_scanned
= 0;
360 while (!list_empty(list
) && count
--) {
361 page
= list_entry(list
->prev
, struct page
, lru
);
362 /* have to delete it as __free_pages_bulk list manipulates */
363 list_del(&page
->lru
);
364 __free_pages_bulk(page
, zone
, order
);
367 spin_unlock_irqrestore(&zone
->lock
, flags
);
371 void __free_pages_ok(struct page
*page
, unsigned int order
)
376 arch_free_page(page
, order
);
378 mod_page_state(pgfree
, 1 << order
);
382 for (i
= 1 ; i
< (1 << order
) ; ++i
)
383 __put_page(page
+ i
);
386 for (i
= 0 ; i
< (1 << order
) ; ++i
)
387 free_pages_check(__FUNCTION__
, page
+ i
);
388 list_add(&page
->lru
, &list
);
389 kernel_map_pages(page
, 1<<order
, 0);
390 free_pages_bulk(page_zone(page
), 1, &list
, order
);
395 * The order of subdivision here is critical for the IO subsystem.
396 * Please do not alter this order without good reasons and regression
397 * testing. Specifically, as large blocks of memory are subdivided,
398 * the order in which smaller blocks are delivered depends on the order
399 * they're subdivided in this function. This is the primary factor
400 * influencing the order in which pages are delivered to the IO
401 * subsystem according to empirical testing, and this is also justified
402 * by considering the behavior of a buddy system containing a single
403 * large block of memory acted on by a series of small allocations.
404 * This behavior is a critical factor in sglist merging's success.
408 static inline struct page
*
409 expand(struct zone
*zone
, struct page
*page
,
410 int low
, int high
, struct free_area
*area
)
412 unsigned long size
= 1 << high
;
418 BUG_ON(bad_range(zone
, &page
[size
]));
419 list_add(&page
[size
].lru
, &area
->free_list
);
421 set_page_order(&page
[size
], high
);
426 void set_page_refs(struct page
*page
, int order
)
429 set_page_count(page
, 1);
434 * We need to reference all the pages for this order, otherwise if
435 * anyone accesses one of the pages with (get/put) it will be freed.
436 * - eg: access_process_vm()
438 for (i
= 0; i
< (1 << order
); i
++)
439 set_page_count(page
+ i
, 1);
440 #endif /* CONFIG_MMU */
444 * This page is about to be returned from the page allocator
446 static void prep_new_page(struct page
*page
, int order
)
448 if (page
->mapping
|| page_mapcount(page
) ||
457 1 << PG_writeback
)))
458 bad_page(__FUNCTION__
, page
);
460 page
->flags
&= ~(1 << PG_uptodate
| 1 << PG_error
|
461 1 << PG_referenced
| 1 << PG_arch_1
|
462 1 << PG_checked
| 1 << PG_mappedtodisk
);
464 set_page_refs(page
, order
);
465 kernel_map_pages(page
, 1 << order
, 1);
469 * Do the hard work of removing an element from the buddy allocator.
470 * Call me with the zone->lock already held.
472 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
)
474 struct free_area
* area
;
475 unsigned int current_order
;
478 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
479 area
= zone
->free_area
+ current_order
;
480 if (list_empty(&area
->free_list
))
483 page
= list_entry(area
->free_list
.next
, struct page
, lru
);
484 list_del(&page
->lru
);
485 rmv_page_order(page
);
487 zone
->free_pages
-= 1UL << order
;
488 return expand(zone
, page
, order
, current_order
, area
);
495 * Obtain a specified number of elements from the buddy allocator, all under
496 * a single hold of the lock, for efficiency. Add them to the supplied list.
497 * Returns the number of new pages which were placed at *list.
499 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
500 unsigned long count
, struct list_head
*list
)
507 spin_lock_irqsave(&zone
->lock
, flags
);
508 for (i
= 0; i
< count
; ++i
) {
509 page
= __rmqueue(zone
, order
);
513 list_add_tail(&page
->lru
, list
);
515 spin_unlock_irqrestore(&zone
->lock
, flags
);
519 #if defined(CONFIG_PM) || defined(CONFIG_HOTPLUG_CPU)
520 static void __drain_pages(unsigned int cpu
)
525 for_each_zone(zone
) {
526 struct per_cpu_pageset
*pset
;
528 pset
= zone_pcp(zone
, cpu
);
529 for (i
= 0; i
< ARRAY_SIZE(pset
->pcp
); i
++) {
530 struct per_cpu_pages
*pcp
;
533 pcp
->count
-= free_pages_bulk(zone
, pcp
->count
,
538 #endif /* CONFIG_PM || CONFIG_HOTPLUG_CPU */
542 void mark_free_pages(struct zone
*zone
)
544 unsigned long zone_pfn
, flags
;
546 struct list_head
*curr
;
548 if (!zone
->spanned_pages
)
551 spin_lock_irqsave(&zone
->lock
, flags
);
552 for (zone_pfn
= 0; zone_pfn
< zone
->spanned_pages
; ++zone_pfn
)
553 ClearPageNosaveFree(pfn_to_page(zone_pfn
+ zone
->zone_start_pfn
));
555 for (order
= MAX_ORDER
- 1; order
>= 0; --order
)
556 list_for_each(curr
, &zone
->free_area
[order
].free_list
) {
557 unsigned long start_pfn
, i
;
559 start_pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
561 for (i
=0; i
< (1<<order
); i
++)
562 SetPageNosaveFree(pfn_to_page(start_pfn
+i
));
564 spin_unlock_irqrestore(&zone
->lock
, flags
);
568 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
570 void drain_local_pages(void)
574 local_irq_save(flags
);
575 __drain_pages(smp_processor_id());
576 local_irq_restore(flags
);
578 #endif /* CONFIG_PM */
580 static void zone_statistics(struct zonelist
*zonelist
, struct zone
*z
)
585 pg_data_t
*pg
= z
->zone_pgdat
;
586 pg_data_t
*orig
= zonelist
->zones
[0]->zone_pgdat
;
587 struct per_cpu_pageset
*p
;
589 local_irq_save(flags
);
590 cpu
= smp_processor_id();
596 zone_pcp(zonelist
->zones
[0], cpu
)->numa_foreign
++;
598 if (pg
== NODE_DATA(numa_node_id()))
602 local_irq_restore(flags
);
607 * Free a 0-order page
609 static void FASTCALL(free_hot_cold_page(struct page
*page
, int cold
));
610 static void fastcall
free_hot_cold_page(struct page
*page
, int cold
)
612 struct zone
*zone
= page_zone(page
);
613 struct per_cpu_pages
*pcp
;
616 arch_free_page(page
, 0);
618 kernel_map_pages(page
, 1, 0);
619 inc_page_state(pgfree
);
621 page
->mapping
= NULL
;
622 free_pages_check(__FUNCTION__
, page
);
623 pcp
= &zone_pcp(zone
, get_cpu())->pcp
[cold
];
624 local_irq_save(flags
);
625 if (pcp
->count
>= pcp
->high
)
626 pcp
->count
-= free_pages_bulk(zone
, pcp
->batch
, &pcp
->list
, 0);
627 list_add(&page
->lru
, &pcp
->list
);
629 local_irq_restore(flags
);
633 void fastcall
free_hot_page(struct page
*page
)
635 free_hot_cold_page(page
, 0);
638 void fastcall
free_cold_page(struct page
*page
)
640 free_hot_cold_page(page
, 1);
643 static inline void prep_zero_page(struct page
*page
, int order
, unsigned int __nocast gfp_flags
)
647 BUG_ON((gfp_flags
& (__GFP_WAIT
| __GFP_HIGHMEM
)) == __GFP_HIGHMEM
);
648 for(i
= 0; i
< (1 << order
); i
++)
649 clear_highpage(page
+ i
);
653 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
654 * we cheat by calling it from here, in the order > 0 path. Saves a branch
658 buffered_rmqueue(struct zone
*zone
, int order
, unsigned int __nocast gfp_flags
)
661 struct page
*page
= NULL
;
662 int cold
= !!(gfp_flags
& __GFP_COLD
);
665 struct per_cpu_pages
*pcp
;
667 pcp
= &zone_pcp(zone
, get_cpu())->pcp
[cold
];
668 local_irq_save(flags
);
669 if (pcp
->count
<= pcp
->low
)
670 pcp
->count
+= rmqueue_bulk(zone
, 0,
671 pcp
->batch
, &pcp
->list
);
673 page
= list_entry(pcp
->list
.next
, struct page
, lru
);
674 list_del(&page
->lru
);
677 local_irq_restore(flags
);
682 spin_lock_irqsave(&zone
->lock
, flags
);
683 page
= __rmqueue(zone
, order
);
684 spin_unlock_irqrestore(&zone
->lock
, flags
);
688 BUG_ON(bad_range(zone
, page
));
689 mod_page_state_zone(zone
, pgalloc
, 1 << order
);
690 prep_new_page(page
, order
);
692 if (gfp_flags
& __GFP_ZERO
)
693 prep_zero_page(page
, order
, gfp_flags
);
695 if (order
&& (gfp_flags
& __GFP_COMP
))
696 prep_compound_page(page
, order
);
702 * Return 1 if free pages are above 'mark'. This takes into account the order
705 int zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
706 int classzone_idx
, int can_try_harder
, int gfp_high
)
708 /* free_pages my go negative - that's OK */
709 long min
= mark
, free_pages
= z
->free_pages
- (1 << order
) + 1;
717 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
719 for (o
= 0; o
< order
; o
++) {
720 /* At the next order, this order's pages become unavailable */
721 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
723 /* Require fewer higher order pages to be free */
726 if (free_pages
<= min
)
733 should_reclaim_zone(struct zone
*z
, unsigned int gfp_mask
)
735 if (!z
->reclaim_pages
)
737 if (gfp_mask
& __GFP_NORECLAIM
)
743 * This is the 'heart' of the zoned buddy allocator.
745 struct page
* fastcall
746 __alloc_pages(unsigned int __nocast gfp_mask
, unsigned int order
,
747 struct zonelist
*zonelist
)
749 const int wait
= gfp_mask
& __GFP_WAIT
;
750 struct zone
**zones
, *z
;
752 struct reclaim_state reclaim_state
;
753 struct task_struct
*p
= current
;
758 int did_some_progress
;
760 might_sleep_if(wait
);
763 * The caller may dip into page reserves a bit more if the caller
764 * cannot run direct reclaim, or is the caller has realtime scheduling
767 can_try_harder
= (unlikely(rt_task(p
)) && !in_interrupt()) || !wait
;
769 zones
= zonelist
->zones
; /* the list of zones suitable for gfp_mask */
771 if (unlikely(zones
[0] == NULL
)) {
772 /* Should this ever happen?? */
776 classzone_idx
= zone_idx(zones
[0]);
779 /* Go through the zonelist once, looking for a zone with enough free */
780 for (i
= 0; (z
= zones
[i
]) != NULL
; i
++) {
781 int do_reclaim
= should_reclaim_zone(z
, gfp_mask
);
783 if (!cpuset_zone_allowed(z
))
787 * If the zone is to attempt early page reclaim then this loop
788 * will try to reclaim pages and check the watermark a second
789 * time before giving up and falling back to the next zone.
792 if (!zone_watermark_ok(z
, order
, z
->pages_low
,
793 classzone_idx
, 0, 0)) {
797 zone_reclaim(z
, gfp_mask
, order
);
798 /* Only try reclaim once */
800 goto zone_reclaim_retry
;
804 page
= buffered_rmqueue(z
, order
, gfp_mask
);
809 for (i
= 0; (z
= zones
[i
]) != NULL
; i
++)
810 wakeup_kswapd(z
, order
);
813 * Go through the zonelist again. Let __GFP_HIGH and allocations
814 * coming from realtime tasks to go deeper into reserves
816 * This is the last chance, in general, before the goto nopage.
817 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
819 for (i
= 0; (z
= zones
[i
]) != NULL
; i
++) {
820 if (!zone_watermark_ok(z
, order
, z
->pages_min
,
821 classzone_idx
, can_try_harder
,
822 gfp_mask
& __GFP_HIGH
))
825 if (wait
&& !cpuset_zone_allowed(z
))
828 page
= buffered_rmqueue(z
, order
, gfp_mask
);
833 /* This allocation should allow future memory freeing. */
835 if (((p
->flags
& PF_MEMALLOC
) || unlikely(test_thread_flag(TIF_MEMDIE
)))
836 && !in_interrupt()) {
837 if (!(gfp_mask
& __GFP_NOMEMALLOC
)) {
838 /* go through the zonelist yet again, ignoring mins */
839 for (i
= 0; (z
= zones
[i
]) != NULL
; i
++) {
840 if (!cpuset_zone_allowed(z
))
842 page
= buffered_rmqueue(z
, order
, gfp_mask
);
850 /* Atomic allocations - we can't balance anything */
857 /* We now go into synchronous reclaim */
858 p
->flags
|= PF_MEMALLOC
;
859 reclaim_state
.reclaimed_slab
= 0;
860 p
->reclaim_state
= &reclaim_state
;
862 did_some_progress
= try_to_free_pages(zones
, gfp_mask
);
864 p
->reclaim_state
= NULL
;
865 p
->flags
&= ~PF_MEMALLOC
;
869 if (likely(did_some_progress
)) {
871 * Go through the zonelist yet one more time, keep
872 * very high watermark here, this is only to catch
873 * a parallel oom killing, we must fail if we're still
874 * under heavy pressure.
876 for (i
= 0; (z
= zones
[i
]) != NULL
; i
++) {
877 if (!zone_watermark_ok(z
, order
, z
->pages_min
,
878 classzone_idx
, can_try_harder
,
879 gfp_mask
& __GFP_HIGH
))
882 if (!cpuset_zone_allowed(z
))
885 page
= buffered_rmqueue(z
, order
, gfp_mask
);
889 } else if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
891 * Go through the zonelist yet one more time, keep
892 * very high watermark here, this is only to catch
893 * a parallel oom killing, we must fail if we're still
894 * under heavy pressure.
896 for (i
= 0; (z
= zones
[i
]) != NULL
; i
++) {
897 if (!zone_watermark_ok(z
, order
, z
->pages_high
,
898 classzone_idx
, 0, 0))
901 if (!cpuset_zone_allowed(z
))
904 page
= buffered_rmqueue(z
, order
, gfp_mask
);
909 out_of_memory(gfp_mask
);
914 * Don't let big-order allocations loop unless the caller explicitly
915 * requests that. Wait for some write requests to complete then retry.
917 * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order
918 * <= 3, but that may not be true in other implementations.
921 if (!(gfp_mask
& __GFP_NORETRY
)) {
922 if ((order
<= 3) || (gfp_mask
& __GFP_REPEAT
))
924 if (gfp_mask
& __GFP_NOFAIL
)
928 blk_congestion_wait(WRITE
, HZ
/50);
933 if (!(gfp_mask
& __GFP_NOWARN
) && printk_ratelimit()) {
934 printk(KERN_WARNING
"%s: page allocation failure."
935 " order:%d, mode:0x%x\n",
936 p
->comm
, order
, gfp_mask
);
941 zone_statistics(zonelist
, z
);
945 EXPORT_SYMBOL(__alloc_pages
);
948 * Common helper functions.
950 fastcall
unsigned long __get_free_pages(unsigned int __nocast gfp_mask
, unsigned int order
)
953 page
= alloc_pages(gfp_mask
, order
);
956 return (unsigned long) page_address(page
);
959 EXPORT_SYMBOL(__get_free_pages
);
961 fastcall
unsigned long get_zeroed_page(unsigned int __nocast gfp_mask
)
966 * get_zeroed_page() returns a 32-bit address, which cannot represent
969 BUG_ON(gfp_mask
& __GFP_HIGHMEM
);
971 page
= alloc_pages(gfp_mask
| __GFP_ZERO
, 0);
973 return (unsigned long) page_address(page
);
977 EXPORT_SYMBOL(get_zeroed_page
);
979 void __pagevec_free(struct pagevec
*pvec
)
981 int i
= pagevec_count(pvec
);
984 free_hot_cold_page(pvec
->pages
[i
], pvec
->cold
);
987 fastcall
void __free_pages(struct page
*page
, unsigned int order
)
989 if (!PageReserved(page
) && put_page_testzero(page
)) {
993 __free_pages_ok(page
, order
);
997 EXPORT_SYMBOL(__free_pages
);
999 fastcall
void free_pages(unsigned long addr
, unsigned int order
)
1002 BUG_ON(!virt_addr_valid((void *)addr
));
1003 __free_pages(virt_to_page((void *)addr
), order
);
1007 EXPORT_SYMBOL(free_pages
);
1010 * Total amount of free (allocatable) RAM:
1012 unsigned int nr_free_pages(void)
1014 unsigned int sum
= 0;
1018 sum
+= zone
->free_pages
;
1023 EXPORT_SYMBOL(nr_free_pages
);
1026 unsigned int nr_free_pages_pgdat(pg_data_t
*pgdat
)
1028 unsigned int i
, sum
= 0;
1030 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
1031 sum
+= pgdat
->node_zones
[i
].free_pages
;
1037 static unsigned int nr_free_zone_pages(int offset
)
1040 unsigned int sum
= 0;
1042 for_each_pgdat(pgdat
) {
1043 struct zonelist
*zonelist
= pgdat
->node_zonelists
+ offset
;
1044 struct zone
**zonep
= zonelist
->zones
;
1047 for (zone
= *zonep
++; zone
; zone
= *zonep
++) {
1048 unsigned long size
= zone
->present_pages
;
1049 unsigned long high
= zone
->pages_high
;
1059 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
1061 unsigned int nr_free_buffer_pages(void)
1063 return nr_free_zone_pages(GFP_USER
& GFP_ZONEMASK
);
1067 * Amount of free RAM allocatable within all zones
1069 unsigned int nr_free_pagecache_pages(void)
1071 return nr_free_zone_pages(GFP_HIGHUSER
& GFP_ZONEMASK
);
1074 #ifdef CONFIG_HIGHMEM
1075 unsigned int nr_free_highpages (void)
1078 unsigned int pages
= 0;
1080 for_each_pgdat(pgdat
)
1081 pages
+= pgdat
->node_zones
[ZONE_HIGHMEM
].free_pages
;
1088 static void show_node(struct zone
*zone
)
1090 printk("Node %d ", zone
->zone_pgdat
->node_id
);
1093 #define show_node(zone) do { } while (0)
1097 * Accumulate the page_state information across all CPUs.
1098 * The result is unavoidably approximate - it can change
1099 * during and after execution of this function.
1101 static DEFINE_PER_CPU(struct page_state
, page_states
) = {0};
1103 atomic_t nr_pagecache
= ATOMIC_INIT(0);
1104 EXPORT_SYMBOL(nr_pagecache
);
1106 DEFINE_PER_CPU(long, nr_pagecache_local
) = 0;
1109 void __get_page_state(struct page_state
*ret
, int nr
)
1113 memset(ret
, 0, sizeof(*ret
));
1115 cpu
= first_cpu(cpu_online_map
);
1116 while (cpu
< NR_CPUS
) {
1117 unsigned long *in
, *out
, off
;
1119 in
= (unsigned long *)&per_cpu(page_states
, cpu
);
1121 cpu
= next_cpu(cpu
, cpu_online_map
);
1124 prefetch(&per_cpu(page_states
, cpu
));
1126 out
= (unsigned long *)ret
;
1127 for (off
= 0; off
< nr
; off
++)
1132 void get_page_state(struct page_state
*ret
)
1136 nr
= offsetof(struct page_state
, GET_PAGE_STATE_LAST
);
1137 nr
/= sizeof(unsigned long);
1139 __get_page_state(ret
, nr
+ 1);
1142 void get_full_page_state(struct page_state
*ret
)
1144 __get_page_state(ret
, sizeof(*ret
) / sizeof(unsigned long));
1147 unsigned long __read_page_state(unsigned long offset
)
1149 unsigned long ret
= 0;
1152 for_each_online_cpu(cpu
) {
1155 in
= (unsigned long)&per_cpu(page_states
, cpu
) + offset
;
1156 ret
+= *((unsigned long *)in
);
1161 void __mod_page_state(unsigned long offset
, unsigned long delta
)
1163 unsigned long flags
;
1166 local_irq_save(flags
);
1167 ptr
= &__get_cpu_var(page_states
);
1168 *(unsigned long*)(ptr
+ offset
) += delta
;
1169 local_irq_restore(flags
);
1172 EXPORT_SYMBOL(__mod_page_state
);
1174 void __get_zone_counts(unsigned long *active
, unsigned long *inactive
,
1175 unsigned long *free
, struct pglist_data
*pgdat
)
1177 struct zone
*zones
= pgdat
->node_zones
;
1183 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
1184 *active
+= zones
[i
].nr_active
;
1185 *inactive
+= zones
[i
].nr_inactive
;
1186 *free
+= zones
[i
].free_pages
;
1190 void get_zone_counts(unsigned long *active
,
1191 unsigned long *inactive
, unsigned long *free
)
1193 struct pglist_data
*pgdat
;
1198 for_each_pgdat(pgdat
) {
1199 unsigned long l
, m
, n
;
1200 __get_zone_counts(&l
, &m
, &n
, pgdat
);
1207 void si_meminfo(struct sysinfo
*val
)
1209 val
->totalram
= totalram_pages
;
1211 val
->freeram
= nr_free_pages();
1212 val
->bufferram
= nr_blockdev_pages();
1213 #ifdef CONFIG_HIGHMEM
1214 val
->totalhigh
= totalhigh_pages
;
1215 val
->freehigh
= nr_free_highpages();
1220 val
->mem_unit
= PAGE_SIZE
;
1223 EXPORT_SYMBOL(si_meminfo
);
1226 void si_meminfo_node(struct sysinfo
*val
, int nid
)
1228 pg_data_t
*pgdat
= NODE_DATA(nid
);
1230 val
->totalram
= pgdat
->node_present_pages
;
1231 val
->freeram
= nr_free_pages_pgdat(pgdat
);
1232 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
1233 val
->freehigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].free_pages
;
1234 val
->mem_unit
= PAGE_SIZE
;
1238 #define K(x) ((x) << (PAGE_SHIFT-10))
1241 * Show free area list (used inside shift_scroll-lock stuff)
1242 * We also calculate the percentage fragmentation. We do this by counting the
1243 * memory on each free list with the exception of the first item on the list.
1245 void show_free_areas(void)
1247 struct page_state ps
;
1248 int cpu
, temperature
;
1249 unsigned long active
;
1250 unsigned long inactive
;
1254 for_each_zone(zone
) {
1256 printk("%s per-cpu:", zone
->name
);
1258 if (!zone
->present_pages
) {
1264 for (cpu
= 0; cpu
< NR_CPUS
; ++cpu
) {
1265 struct per_cpu_pageset
*pageset
;
1267 if (!cpu_possible(cpu
))
1270 pageset
= zone_pcp(zone
, cpu
);
1272 for (temperature
= 0; temperature
< 2; temperature
++)
1273 printk("cpu %d %s: low %d, high %d, batch %d\n",
1275 temperature
? "cold" : "hot",
1276 pageset
->pcp
[temperature
].low
,
1277 pageset
->pcp
[temperature
].high
,
1278 pageset
->pcp
[temperature
].batch
);
1282 get_page_state(&ps
);
1283 get_zone_counts(&active
, &inactive
, &free
);
1285 printk("\nFree pages: %11ukB (%ukB HighMem)\n",
1287 K(nr_free_highpages()));
1289 printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu "
1290 "unstable:%lu free:%u slab:%lu mapped:%lu pagetables:%lu\n",
1299 ps
.nr_page_table_pages
);
1301 for_each_zone(zone
) {
1313 " pages_scanned:%lu"
1314 " all_unreclaimable? %s"
1317 K(zone
->free_pages
),
1320 K(zone
->pages_high
),
1322 K(zone
->nr_inactive
),
1323 K(zone
->present_pages
),
1324 zone
->pages_scanned
,
1325 (zone
->all_unreclaimable
? "yes" : "no")
1327 printk("lowmem_reserve[]:");
1328 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
1329 printk(" %lu", zone
->lowmem_reserve
[i
]);
1333 for_each_zone(zone
) {
1334 unsigned long nr
, flags
, order
, total
= 0;
1337 printk("%s: ", zone
->name
);
1338 if (!zone
->present_pages
) {
1343 spin_lock_irqsave(&zone
->lock
, flags
);
1344 for (order
= 0; order
< MAX_ORDER
; order
++) {
1345 nr
= zone
->free_area
[order
].nr_free
;
1346 total
+= nr
<< order
;
1347 printk("%lu*%lukB ", nr
, K(1UL) << order
);
1349 spin_unlock_irqrestore(&zone
->lock
, flags
);
1350 printk("= %lukB\n", K(total
));
1353 show_swap_cache_info();
1357 * Builds allocation fallback zone lists.
1359 static int __init
build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
, int j
, int k
)
1366 zone
= pgdat
->node_zones
+ ZONE_HIGHMEM
;
1367 if (zone
->present_pages
) {
1368 #ifndef CONFIG_HIGHMEM
1371 zonelist
->zones
[j
++] = zone
;
1374 zone
= pgdat
->node_zones
+ ZONE_NORMAL
;
1375 if (zone
->present_pages
)
1376 zonelist
->zones
[j
++] = zone
;
1378 zone
= pgdat
->node_zones
+ ZONE_DMA
;
1379 if (zone
->present_pages
)
1380 zonelist
->zones
[j
++] = zone
;
1387 #define MAX_NODE_LOAD (num_online_nodes())
1388 static int __initdata node_load
[MAX_NUMNODES
];
1390 * find_next_best_node - find the next node that should appear in a given node's fallback list
1391 * @node: node whose fallback list we're appending
1392 * @used_node_mask: nodemask_t of already used nodes
1394 * We use a number of factors to determine which is the next node that should
1395 * appear on a given node's fallback list. The node should not have appeared
1396 * already in @node's fallback list, and it should be the next closest node
1397 * according to the distance array (which contains arbitrary distance values
1398 * from each node to each node in the system), and should also prefer nodes
1399 * with no CPUs, since presumably they'll have very little allocation pressure
1400 * on them otherwise.
1401 * It returns -1 if no node is found.
1403 static int __init
find_next_best_node(int node
, nodemask_t
*used_node_mask
)
1406 int min_val
= INT_MAX
;
1409 for_each_online_node(i
) {
1412 /* Start from local node */
1413 n
= (node
+i
) % num_online_nodes();
1415 /* Don't want a node to appear more than once */
1416 if (node_isset(n
, *used_node_mask
))
1419 /* Use the local node if we haven't already */
1420 if (!node_isset(node
, *used_node_mask
)) {
1425 /* Use the distance array to find the distance */
1426 val
= node_distance(node
, n
);
1428 /* Give preference to headless and unused nodes */
1429 tmp
= node_to_cpumask(n
);
1430 if (!cpus_empty(tmp
))
1431 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
1433 /* Slight preference for less loaded node */
1434 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
1435 val
+= node_load
[n
];
1437 if (val
< min_val
) {
1444 node_set(best_node
, *used_node_mask
);
1449 static void __init
build_zonelists(pg_data_t
*pgdat
)
1451 int i
, j
, k
, node
, local_node
;
1452 int prev_node
, load
;
1453 struct zonelist
*zonelist
;
1454 nodemask_t used_mask
;
1456 /* initialize zonelists */
1457 for (i
= 0; i
< GFP_ZONETYPES
; i
++) {
1458 zonelist
= pgdat
->node_zonelists
+ i
;
1459 zonelist
->zones
[0] = NULL
;
1462 /* NUMA-aware ordering of nodes */
1463 local_node
= pgdat
->node_id
;
1464 load
= num_online_nodes();
1465 prev_node
= local_node
;
1466 nodes_clear(used_mask
);
1467 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
1469 * We don't want to pressure a particular node.
1470 * So adding penalty to the first node in same
1471 * distance group to make it round-robin.
1473 if (node_distance(local_node
, node
) !=
1474 node_distance(local_node
, prev_node
))
1475 node_load
[node
] += load
;
1478 for (i
= 0; i
< GFP_ZONETYPES
; i
++) {
1479 zonelist
= pgdat
->node_zonelists
+ i
;
1480 for (j
= 0; zonelist
->zones
[j
] != NULL
; j
++);
1483 if (i
& __GFP_HIGHMEM
)
1488 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
, k
);
1489 zonelist
->zones
[j
] = NULL
;
1494 #else /* CONFIG_NUMA */
1496 static void __init
build_zonelists(pg_data_t
*pgdat
)
1498 int i
, j
, k
, node
, local_node
;
1500 local_node
= pgdat
->node_id
;
1501 for (i
= 0; i
< GFP_ZONETYPES
; i
++) {
1502 struct zonelist
*zonelist
;
1504 zonelist
= pgdat
->node_zonelists
+ i
;
1508 if (i
& __GFP_HIGHMEM
)
1513 j
= build_zonelists_node(pgdat
, zonelist
, j
, k
);
1515 * Now we build the zonelist so that it contains the zones
1516 * of all the other nodes.
1517 * We don't want to pressure a particular node, so when
1518 * building the zones for node N, we make sure that the
1519 * zones coming right after the local ones are those from
1520 * node N+1 (modulo N)
1522 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
1523 if (!node_online(node
))
1525 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
, k
);
1527 for (node
= 0; node
< local_node
; node
++) {
1528 if (!node_online(node
))
1530 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
, k
);
1533 zonelist
->zones
[j
] = NULL
;
1537 #endif /* CONFIG_NUMA */
1539 void __init
build_all_zonelists(void)
1543 for_each_online_node(i
)
1544 build_zonelists(NODE_DATA(i
));
1545 printk("Built %i zonelists\n", num_online_nodes());
1546 cpuset_init_current_mems_allowed();
1550 * Helper functions to size the waitqueue hash table.
1551 * Essentially these want to choose hash table sizes sufficiently
1552 * large so that collisions trying to wait on pages are rare.
1553 * But in fact, the number of active page waitqueues on typical
1554 * systems is ridiculously low, less than 200. So this is even
1555 * conservative, even though it seems large.
1557 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
1558 * waitqueues, i.e. the size of the waitq table given the number of pages.
1560 #define PAGES_PER_WAITQUEUE 256
1562 static inline unsigned long wait_table_size(unsigned long pages
)
1564 unsigned long size
= 1;
1566 pages
/= PAGES_PER_WAITQUEUE
;
1568 while (size
< pages
)
1572 * Once we have dozens or even hundreds of threads sleeping
1573 * on IO we've got bigger problems than wait queue collision.
1574 * Limit the size of the wait table to a reasonable size.
1576 size
= min(size
, 4096UL);
1578 return max(size
, 4UL);
1582 * This is an integer logarithm so that shifts can be used later
1583 * to extract the more random high bits from the multiplicative
1584 * hash function before the remainder is taken.
1586 static inline unsigned long wait_table_bits(unsigned long size
)
1591 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
1593 static void __init
calculate_zone_totalpages(struct pglist_data
*pgdat
,
1594 unsigned long *zones_size
, unsigned long *zholes_size
)
1596 unsigned long realtotalpages
, totalpages
= 0;
1599 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
1600 totalpages
+= zones_size
[i
];
1601 pgdat
->node_spanned_pages
= totalpages
;
1603 realtotalpages
= totalpages
;
1605 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
1606 realtotalpages
-= zholes_size
[i
];
1607 pgdat
->node_present_pages
= realtotalpages
;
1608 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
, realtotalpages
);
1613 * Initially all pages are reserved - free ones are freed
1614 * up by free_all_bootmem() once the early boot process is
1615 * done. Non-atomic initialization, single-pass.
1617 void __init
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
1618 unsigned long start_pfn
)
1620 struct page
*start
= pfn_to_page(start_pfn
);
1623 for (page
= start
; page
< (start
+ size
); page
++) {
1624 set_page_zone(page
, NODEZONE(nid
, zone
));
1625 set_page_count(page
, 0);
1626 reset_page_mapcount(page
);
1627 SetPageReserved(page
);
1628 INIT_LIST_HEAD(&page
->lru
);
1629 #ifdef WANT_PAGE_VIRTUAL
1630 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1631 if (!is_highmem_idx(zone
))
1632 set_page_address(page
, __va(start_pfn
<< PAGE_SHIFT
));
1638 void zone_init_free_lists(struct pglist_data
*pgdat
, struct zone
*zone
,
1642 for (order
= 0; order
< MAX_ORDER
; order
++) {
1643 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
);
1644 zone
->free_area
[order
].nr_free
= 0;
1648 #ifndef __HAVE_ARCH_MEMMAP_INIT
1649 #define memmap_init(size, nid, zone, start_pfn) \
1650 memmap_init_zone((size), (nid), (zone), (start_pfn))
1653 static int __devinit
zone_batchsize(struct zone
*zone
)
1658 * The per-cpu-pages pools are set to around 1000th of the
1659 * size of the zone. But no more than 1/4 of a meg - there's
1660 * no point in going beyond the size of L2 cache.
1662 * OK, so we don't know how big the cache is. So guess.
1664 batch
= zone
->present_pages
/ 1024;
1665 if (batch
* PAGE_SIZE
> 256 * 1024)
1666 batch
= (256 * 1024) / PAGE_SIZE
;
1667 batch
/= 4; /* We effectively *= 4 below */
1672 * Clamp the batch to a 2^n - 1 value. Having a power
1673 * of 2 value was found to be more likely to have
1674 * suboptimal cache aliasing properties in some cases.
1676 * For example if 2 tasks are alternately allocating
1677 * batches of pages, one task can end up with a lot
1678 * of pages of one half of the possible page colors
1679 * and the other with pages of the other colors.
1681 batch
= (1 << fls(batch
+ batch
/2)) - 1;
1687 * Dynamicaly allocate memory for the
1688 * per cpu pageset array in struct zone.
1690 static int __devinit
process_zones(int cpu
)
1692 struct zone
*zone
, *dzone
;
1695 for_each_zone(zone
) {
1696 struct per_cpu_pageset
*npageset
= NULL
;
1698 npageset
= kmalloc_node(sizeof(struct per_cpu_pageset
),
1699 GFP_KERNEL
, cpu_to_node(cpu
));
1701 zone
->pageset
[cpu
] = NULL
;
1705 if (zone
->pageset
[cpu
]) {
1706 memcpy(npageset
, zone
->pageset
[cpu
],
1707 sizeof(struct per_cpu_pageset
));
1709 /* Relocate lists */
1710 for (i
= 0; i
< 2; i
++) {
1711 INIT_LIST_HEAD(&npageset
->pcp
[i
].list
);
1712 list_splice(&zone
->pageset
[cpu
]->pcp
[i
].list
,
1713 &npageset
->pcp
[i
].list
);
1716 struct per_cpu_pages
*pcp
;
1717 unsigned long batch
;
1719 batch
= zone_batchsize(zone
);
1721 pcp
= &npageset
->pcp
[0]; /* hot */
1723 pcp
->low
= 2 * batch
;
1724 pcp
->high
= 6 * batch
;
1725 pcp
->batch
= 1 * batch
;
1726 INIT_LIST_HEAD(&pcp
->list
);
1728 pcp
= &npageset
->pcp
[1]; /* cold*/
1731 pcp
->high
= 2 * batch
;
1732 pcp
->batch
= 1 * batch
;
1733 INIT_LIST_HEAD(&pcp
->list
);
1735 zone
->pageset
[cpu
] = npageset
;
1740 for_each_zone(dzone
) {
1743 kfree(dzone
->pageset
[cpu
]);
1744 dzone
->pageset
[cpu
] = NULL
;
1749 static inline void free_zone_pagesets(int cpu
)
1754 for_each_zone(zone
) {
1755 struct per_cpu_pageset
*pset
= zone_pcp(zone
, cpu
);
1757 zone_pcp(zone
, cpu
) = NULL
;
1763 static int __devinit
pageset_cpuup_callback(struct notifier_block
*nfb
,
1764 unsigned long action
,
1767 int cpu
= (long)hcpu
;
1768 int ret
= NOTIFY_OK
;
1771 case CPU_UP_PREPARE
:
1772 if (process_zones(cpu
))
1775 #ifdef CONFIG_HOTPLUG_CPU
1777 free_zone_pagesets(cpu
);
1786 static struct notifier_block pageset_notifier
=
1787 { &pageset_cpuup_callback
, NULL
, 0 };
1789 void __init
setup_per_cpu_pageset()
1793 /* Initialize per_cpu_pageset for cpu 0.
1794 * A cpuup callback will do this for every cpu
1795 * as it comes online
1797 err
= process_zones(smp_processor_id());
1799 register_cpu_notifier(&pageset_notifier
);
1805 * Set up the zone data structures:
1806 * - mark all pages reserved
1807 * - mark all memory queues empty
1808 * - clear the memory bitmaps
1810 static void __init
free_area_init_core(struct pglist_data
*pgdat
,
1811 unsigned long *zones_size
, unsigned long *zholes_size
)
1814 const unsigned long zone_required_alignment
= 1UL << (MAX_ORDER
-1);
1815 int cpu
, nid
= pgdat
->node_id
;
1816 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
1818 pgdat
->nr_zones
= 0;
1819 init_waitqueue_head(&pgdat
->kswapd_wait
);
1820 pgdat
->kswapd_max_order
= 0;
1822 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
1823 struct zone
*zone
= pgdat
->node_zones
+ j
;
1824 unsigned long size
, realsize
;
1825 unsigned long batch
;
1827 zone_table
[NODEZONE(nid
, j
)] = zone
;
1828 realsize
= size
= zones_size
[j
];
1830 realsize
-= zholes_size
[j
];
1832 if (j
== ZONE_DMA
|| j
== ZONE_NORMAL
)
1833 nr_kernel_pages
+= realsize
;
1834 nr_all_pages
+= realsize
;
1836 zone
->spanned_pages
= size
;
1837 zone
->present_pages
= realsize
;
1838 zone
->name
= zone_names
[j
];
1839 spin_lock_init(&zone
->lock
);
1840 spin_lock_init(&zone
->lru_lock
);
1841 zone
->zone_pgdat
= pgdat
;
1842 zone
->free_pages
= 0;
1844 zone
->temp_priority
= zone
->prev_priority
= DEF_PRIORITY
;
1846 batch
= zone_batchsize(zone
);
1848 for (cpu
= 0; cpu
< NR_CPUS
; cpu
++) {
1849 struct per_cpu_pages
*pcp
;
1851 struct per_cpu_pageset
*pgset
;
1852 pgset
= &pageset_table
[nid
*MAX_NR_ZONES
*NR_CPUS
+
1853 (j
* NR_CPUS
) + cpu
];
1855 zone
->pageset
[cpu
] = pgset
;
1857 struct per_cpu_pageset
*pgset
= zone_pcp(zone
, cpu
);
1860 pcp
= &pgset
->pcp
[0]; /* hot */
1862 pcp
->low
= 2 * batch
;
1863 pcp
->high
= 6 * batch
;
1864 pcp
->batch
= 1 * batch
;
1865 INIT_LIST_HEAD(&pcp
->list
);
1867 pcp
= &pgset
->pcp
[1]; /* cold */
1870 pcp
->high
= 2 * batch
;
1871 pcp
->batch
= 1 * batch
;
1872 INIT_LIST_HEAD(&pcp
->list
);
1874 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%lu\n",
1875 zone_names
[j
], realsize
, batch
);
1876 INIT_LIST_HEAD(&zone
->active_list
);
1877 INIT_LIST_HEAD(&zone
->inactive_list
);
1878 zone
->nr_scan_active
= 0;
1879 zone
->nr_scan_inactive
= 0;
1880 zone
->nr_active
= 0;
1881 zone
->nr_inactive
= 0;
1882 atomic_set(&zone
->reclaim_in_progress
, -1);
1887 * The per-page waitqueue mechanism uses hashed waitqueues
1890 zone
->wait_table_size
= wait_table_size(size
);
1891 zone
->wait_table_bits
=
1892 wait_table_bits(zone
->wait_table_size
);
1893 zone
->wait_table
= (wait_queue_head_t
*)
1894 alloc_bootmem_node(pgdat
, zone
->wait_table_size
1895 * sizeof(wait_queue_head_t
));
1897 for(i
= 0; i
< zone
->wait_table_size
; ++i
)
1898 init_waitqueue_head(zone
->wait_table
+ i
);
1900 pgdat
->nr_zones
= j
+1;
1902 zone
->zone_mem_map
= pfn_to_page(zone_start_pfn
);
1903 zone
->zone_start_pfn
= zone_start_pfn
;
1905 if ((zone_start_pfn
) & (zone_required_alignment
-1))
1906 printk(KERN_CRIT
"BUG: wrong zone alignment, it will crash\n");
1908 memmap_init(size
, nid
, j
, zone_start_pfn
);
1910 zone_start_pfn
+= size
;
1912 zone_init_free_lists(pgdat
, zone
, zone
->spanned_pages
);
1916 static void __init
alloc_node_mem_map(struct pglist_data
*pgdat
)
1920 /* Skip empty nodes */
1921 if (!pgdat
->node_spanned_pages
)
1924 /* ia64 gets its own node_mem_map, before this, without bootmem */
1925 if (!pgdat
->node_mem_map
) {
1926 size
= (pgdat
->node_spanned_pages
+ 1) * sizeof(struct page
);
1927 pgdat
->node_mem_map
= alloc_bootmem_node(pgdat
, size
);
1929 #ifndef CONFIG_DISCONTIGMEM
1931 * With no DISCONTIG, the global mem_map is just set as node 0's
1933 if (pgdat
== NODE_DATA(0))
1934 mem_map
= NODE_DATA(0)->node_mem_map
;
1938 void __init
free_area_init_node(int nid
, struct pglist_data
*pgdat
,
1939 unsigned long *zones_size
, unsigned long node_start_pfn
,
1940 unsigned long *zholes_size
)
1942 pgdat
->node_id
= nid
;
1943 pgdat
->node_start_pfn
= node_start_pfn
;
1944 calculate_zone_totalpages(pgdat
, zones_size
, zholes_size
);
1946 alloc_node_mem_map(pgdat
);
1948 free_area_init_core(pgdat
, zones_size
, zholes_size
);
1951 #ifndef CONFIG_DISCONTIGMEM
1952 static bootmem_data_t contig_bootmem_data
;
1953 struct pglist_data contig_page_data
= { .bdata
= &contig_bootmem_data
};
1955 EXPORT_SYMBOL(contig_page_data
);
1957 void __init
free_area_init(unsigned long *zones_size
)
1959 free_area_init_node(0, &contig_page_data
, zones_size
,
1960 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
1964 #ifdef CONFIG_PROC_FS
1966 #include <linux/seq_file.h>
1968 static void *frag_start(struct seq_file
*m
, loff_t
*pos
)
1973 for (pgdat
= pgdat_list
; pgdat
&& node
; pgdat
= pgdat
->pgdat_next
)
1979 static void *frag_next(struct seq_file
*m
, void *arg
, loff_t
*pos
)
1981 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1984 return pgdat
->pgdat_next
;
1987 static void frag_stop(struct seq_file
*m
, void *arg
)
1992 * This walks the free areas for each zone.
1994 static int frag_show(struct seq_file
*m
, void *arg
)
1996 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1998 struct zone
*node_zones
= pgdat
->node_zones
;
1999 unsigned long flags
;
2002 for (zone
= node_zones
; zone
- node_zones
< MAX_NR_ZONES
; ++zone
) {
2003 if (!zone
->present_pages
)
2006 spin_lock_irqsave(&zone
->lock
, flags
);
2007 seq_printf(m
, "Node %d, zone %8s ", pgdat
->node_id
, zone
->name
);
2008 for (order
= 0; order
< MAX_ORDER
; ++order
)
2009 seq_printf(m
, "%6lu ", zone
->free_area
[order
].nr_free
);
2010 spin_unlock_irqrestore(&zone
->lock
, flags
);
2016 struct seq_operations fragmentation_op
= {
2017 .start
= frag_start
,
2024 * Output information about zones in @pgdat.
2026 static int zoneinfo_show(struct seq_file
*m
, void *arg
)
2028 pg_data_t
*pgdat
= arg
;
2030 struct zone
*node_zones
= pgdat
->node_zones
;
2031 unsigned long flags
;
2033 for (zone
= node_zones
; zone
- node_zones
< MAX_NR_ZONES
; zone
++) {
2036 if (!zone
->present_pages
)
2039 spin_lock_irqsave(&zone
->lock
, flags
);
2040 seq_printf(m
, "Node %d, zone %8s", pgdat
->node_id
, zone
->name
);
2048 "\n scanned %lu (a: %lu i: %lu)"
2057 zone
->pages_scanned
,
2058 zone
->nr_scan_active
, zone
->nr_scan_inactive
,
2059 zone
->spanned_pages
,
2060 zone
->present_pages
);
2062 "\n protection: (%lu",
2063 zone
->lowmem_reserve
[0]);
2064 for (i
= 1; i
< ARRAY_SIZE(zone
->lowmem_reserve
); i
++)
2065 seq_printf(m
, ", %lu", zone
->lowmem_reserve
[i
]);
2069 for (i
= 0; i
< ARRAY_SIZE(zone
->pageset
); i
++) {
2070 struct per_cpu_pageset
*pageset
;
2073 pageset
= zone_pcp(zone
, i
);
2074 for (j
= 0; j
< ARRAY_SIZE(pageset
->pcp
); j
++) {
2075 if (pageset
->pcp
[j
].count
)
2078 if (j
== ARRAY_SIZE(pageset
->pcp
))
2080 for (j
= 0; j
< ARRAY_SIZE(pageset
->pcp
); j
++) {
2082 "\n cpu: %i pcp: %i"
2088 pageset
->pcp
[j
].count
,
2089 pageset
->pcp
[j
].low
,
2090 pageset
->pcp
[j
].high
,
2091 pageset
->pcp
[j
].batch
);
2097 "\n numa_foreign: %lu"
2098 "\n interleave_hit: %lu"
2099 "\n local_node: %lu"
2100 "\n other_node: %lu",
2103 pageset
->numa_foreign
,
2104 pageset
->interleave_hit
,
2105 pageset
->local_node
,
2106 pageset
->other_node
);
2110 "\n all_unreclaimable: %u"
2111 "\n prev_priority: %i"
2112 "\n temp_priority: %i"
2113 "\n start_pfn: %lu",
2114 zone
->all_unreclaimable
,
2115 zone
->prev_priority
,
2116 zone
->temp_priority
,
2117 zone
->zone_start_pfn
);
2118 spin_unlock_irqrestore(&zone
->lock
, flags
);
2124 struct seq_operations zoneinfo_op
= {
2125 .start
= frag_start
, /* iterate over all zones. The same as in
2129 .show
= zoneinfo_show
,
2132 static char *vmstat_text
[] = {
2136 "nr_page_table_pages",
2161 "pgscan_kswapd_high",
2162 "pgscan_kswapd_normal",
2164 "pgscan_kswapd_dma",
2165 "pgscan_direct_high",
2166 "pgscan_direct_normal",
2167 "pgscan_direct_dma",
2172 "kswapd_inodesteal",
2180 static void *vmstat_start(struct seq_file
*m
, loff_t
*pos
)
2182 struct page_state
*ps
;
2184 if (*pos
>= ARRAY_SIZE(vmstat_text
))
2187 ps
= kmalloc(sizeof(*ps
), GFP_KERNEL
);
2190 return ERR_PTR(-ENOMEM
);
2191 get_full_page_state(ps
);
2192 ps
->pgpgin
/= 2; /* sectors -> kbytes */
2194 return (unsigned long *)ps
+ *pos
;
2197 static void *vmstat_next(struct seq_file
*m
, void *arg
, loff_t
*pos
)
2200 if (*pos
>= ARRAY_SIZE(vmstat_text
))
2202 return (unsigned long *)m
->private + *pos
;
2205 static int vmstat_show(struct seq_file
*m
, void *arg
)
2207 unsigned long *l
= arg
;
2208 unsigned long off
= l
- (unsigned long *)m
->private;
2210 seq_printf(m
, "%s %lu\n", vmstat_text
[off
], *l
);
2214 static void vmstat_stop(struct seq_file
*m
, void *arg
)
2220 struct seq_operations vmstat_op
= {
2221 .start
= vmstat_start
,
2222 .next
= vmstat_next
,
2223 .stop
= vmstat_stop
,
2224 .show
= vmstat_show
,
2227 #endif /* CONFIG_PROC_FS */
2229 #ifdef CONFIG_HOTPLUG_CPU
2230 static int page_alloc_cpu_notify(struct notifier_block
*self
,
2231 unsigned long action
, void *hcpu
)
2233 int cpu
= (unsigned long)hcpu
;
2235 unsigned long *src
, *dest
;
2237 if (action
== CPU_DEAD
) {
2240 /* Drain local pagecache count. */
2241 count
= &per_cpu(nr_pagecache_local
, cpu
);
2242 atomic_add(*count
, &nr_pagecache
);
2244 local_irq_disable();
2247 /* Add dead cpu's page_states to our own. */
2248 dest
= (unsigned long *)&__get_cpu_var(page_states
);
2249 src
= (unsigned long *)&per_cpu(page_states
, cpu
);
2251 for (i
= 0; i
< sizeof(struct page_state
)/sizeof(unsigned long);
2261 #endif /* CONFIG_HOTPLUG_CPU */
2263 void __init
page_alloc_init(void)
2265 hotcpu_notifier(page_alloc_cpu_notify
, 0);
2269 * setup_per_zone_lowmem_reserve - called whenever
2270 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
2271 * has a correct pages reserved value, so an adequate number of
2272 * pages are left in the zone after a successful __alloc_pages().
2274 static void setup_per_zone_lowmem_reserve(void)
2276 struct pglist_data
*pgdat
;
2279 for_each_pgdat(pgdat
) {
2280 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
2281 struct zone
*zone
= pgdat
->node_zones
+ j
;
2282 unsigned long present_pages
= zone
->present_pages
;
2284 zone
->lowmem_reserve
[j
] = 0;
2286 for (idx
= j
-1; idx
>= 0; idx
--) {
2287 struct zone
*lower_zone
;
2289 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
2290 sysctl_lowmem_reserve_ratio
[idx
] = 1;
2292 lower_zone
= pgdat
->node_zones
+ idx
;
2293 lower_zone
->lowmem_reserve
[j
] = present_pages
/
2294 sysctl_lowmem_reserve_ratio
[idx
];
2295 present_pages
+= lower_zone
->present_pages
;
2302 * setup_per_zone_pages_min - called when min_free_kbytes changes. Ensures
2303 * that the pages_{min,low,high} values for each zone are set correctly
2304 * with respect to min_free_kbytes.
2306 static void setup_per_zone_pages_min(void)
2308 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
2309 unsigned long lowmem_pages
= 0;
2311 unsigned long flags
;
2313 /* Calculate total number of !ZONE_HIGHMEM pages */
2314 for_each_zone(zone
) {
2315 if (!is_highmem(zone
))
2316 lowmem_pages
+= zone
->present_pages
;
2319 for_each_zone(zone
) {
2320 spin_lock_irqsave(&zone
->lru_lock
, flags
);
2321 if (is_highmem(zone
)) {
2323 * Often, highmem doesn't need to reserve any pages.
2324 * But the pages_min/low/high values are also used for
2325 * batching up page reclaim activity so we need a
2326 * decent value here.
2330 min_pages
= zone
->present_pages
/ 1024;
2331 if (min_pages
< SWAP_CLUSTER_MAX
)
2332 min_pages
= SWAP_CLUSTER_MAX
;
2333 if (min_pages
> 128)
2335 zone
->pages_min
= min_pages
;
2337 /* if it's a lowmem zone, reserve a number of pages
2338 * proportionate to the zone's size.
2340 zone
->pages_min
= (pages_min
* zone
->present_pages
) /
2345 * When interpreting these watermarks, just keep in mind that:
2346 * zone->pages_min == (zone->pages_min * 4) / 4;
2348 zone
->pages_low
= (zone
->pages_min
* 5) / 4;
2349 zone
->pages_high
= (zone
->pages_min
* 6) / 4;
2350 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
2355 * Initialise min_free_kbytes.
2357 * For small machines we want it small (128k min). For large machines
2358 * we want it large (64MB max). But it is not linear, because network
2359 * bandwidth does not increase linearly with machine size. We use
2361 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
2362 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
2378 static int __init
init_per_zone_pages_min(void)
2380 unsigned long lowmem_kbytes
;
2382 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
2384 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
2385 if (min_free_kbytes
< 128)
2386 min_free_kbytes
= 128;
2387 if (min_free_kbytes
> 65536)
2388 min_free_kbytes
= 65536;
2389 setup_per_zone_pages_min();
2390 setup_per_zone_lowmem_reserve();
2393 module_init(init_per_zone_pages_min
)
2396 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
2397 * that we can call two helper functions whenever min_free_kbytes
2400 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
2401 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
2403 proc_dointvec(table
, write
, file
, buffer
, length
, ppos
);
2404 setup_per_zone_pages_min();
2409 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
2410 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
2411 * whenever sysctl_lowmem_reserve_ratio changes.
2413 * The reserve ratio obviously has absolutely no relation with the
2414 * pages_min watermarks. The lowmem reserve ratio can only make sense
2415 * if in function of the boot time zone sizes.
2417 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
2418 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
2420 proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
2421 setup_per_zone_lowmem_reserve();
2425 __initdata
int hashdist
= HASHDIST_DEFAULT
;
2428 static int __init
set_hashdist(char *str
)
2432 hashdist
= simple_strtoul(str
, &str
, 0);
2435 __setup("hashdist=", set_hashdist
);
2439 * allocate a large system hash table from bootmem
2440 * - it is assumed that the hash table must contain an exact power-of-2
2441 * quantity of entries
2442 * - limit is the number of hash buckets, not the total allocation size
2444 void *__init
alloc_large_system_hash(const char *tablename
,
2445 unsigned long bucketsize
,
2446 unsigned long numentries
,
2449 unsigned int *_hash_shift
,
2450 unsigned int *_hash_mask
,
2451 unsigned long limit
)
2453 unsigned long long max
= limit
;
2454 unsigned long log2qty
, size
;
2457 /* allow the kernel cmdline to have a say */
2459 /* round applicable memory size up to nearest megabyte */
2460 numentries
= (flags
& HASH_HIGHMEM
) ? nr_all_pages
: nr_kernel_pages
;
2461 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
2462 numentries
>>= 20 - PAGE_SHIFT
;
2463 numentries
<<= 20 - PAGE_SHIFT
;
2465 /* limit to 1 bucket per 2^scale bytes of low memory */
2466 if (scale
> PAGE_SHIFT
)
2467 numentries
>>= (scale
- PAGE_SHIFT
);
2469 numentries
<<= (PAGE_SHIFT
- scale
);
2471 /* rounded up to nearest power of 2 in size */
2472 numentries
= 1UL << (long_log2(numentries
) + 1);
2474 /* limit allocation size to 1/16 total memory by default */
2476 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
2477 do_div(max
, bucketsize
);
2480 if (numentries
> max
)
2483 log2qty
= long_log2(numentries
);
2486 size
= bucketsize
<< log2qty
;
2487 if (flags
& HASH_EARLY
)
2488 table
= alloc_bootmem(size
);
2490 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
2492 unsigned long order
;
2493 for (order
= 0; ((1UL << order
) << PAGE_SHIFT
) < size
; order
++)
2495 table
= (void*) __get_free_pages(GFP_ATOMIC
, order
);
2497 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
2500 panic("Failed to allocate %s hash table\n", tablename
);
2502 printk("%s hash table entries: %d (order: %d, %lu bytes)\n",
2505 long_log2(size
) - PAGE_SHIFT
,
2509 *_hash_shift
= log2qty
;
2511 *_hash_mask
= (1 << log2qty
) - 1;