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/bootmem.h>
23 #include <linux/compiler.h>
24 #include <linux/kernel.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/memory_hotplug.h>
36 #include <linux/nodemask.h>
37 #include <linux/vmalloc.h>
38 #include <linux/mempolicy.h>
39 #include <linux/stop_machine.h>
40 #include <linux/sort.h>
41 #include <linux/pfn.h>
42 #include <linux/backing-dev.h>
43 #include <linux/fault-inject.h>
45 #include <asm/tlbflush.h>
46 #include <asm/div64.h>
50 * MCD - HACK: Find somewhere to initialize this EARLY, or make this
53 nodemask_t node_online_map __read_mostly
= { { [0] = 1UL } };
54 EXPORT_SYMBOL(node_online_map
);
55 nodemask_t node_possible_map __read_mostly
= NODE_MASK_ALL
;
56 EXPORT_SYMBOL(node_possible_map
);
57 unsigned long totalram_pages __read_mostly
;
58 unsigned long totalreserve_pages __read_mostly
;
60 int percpu_pagelist_fraction
;
62 static void __free_pages_ok(struct page
*page
, unsigned int order
);
65 * results with 256, 32 in the lowmem_reserve sysctl:
66 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
67 * 1G machine -> (16M dma, 784M normal, 224M high)
68 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
69 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
70 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
72 * TBD: should special case ZONE_DMA32 machines here - in those we normally
73 * don't need any ZONE_NORMAL reservation
75 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
77 #ifdef CONFIG_ZONE_DMA32
85 EXPORT_SYMBOL(totalram_pages
);
87 static char * const zone_names
[MAX_NR_ZONES
] = {
89 #ifdef CONFIG_ZONE_DMA32
98 int min_free_kbytes
= 1024;
100 unsigned long __meminitdata nr_kernel_pages
;
101 unsigned long __meminitdata nr_all_pages
;
102 static unsigned long __initdata dma_reserve
;
104 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
106 * MAX_ACTIVE_REGIONS determines the maxmimum number of distinct
107 * ranges of memory (RAM) that may be registered with add_active_range().
108 * Ranges passed to add_active_range() will be merged if possible
109 * so the number of times add_active_range() can be called is
110 * related to the number of nodes and the number of holes
112 #ifdef CONFIG_MAX_ACTIVE_REGIONS
113 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */
114 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
116 #if MAX_NUMNODES >= 32
117 /* If there can be many nodes, allow up to 50 holes per node */
118 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
120 /* By default, allow up to 256 distinct regions */
121 #define MAX_ACTIVE_REGIONS 256
125 struct node_active_region __initdata early_node_map
[MAX_ACTIVE_REGIONS
];
126 int __initdata nr_nodemap_entries
;
127 unsigned long __initdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
128 unsigned long __initdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
129 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
130 unsigned long __initdata node_boundary_start_pfn
[MAX_NUMNODES
];
131 unsigned long __initdata node_boundary_end_pfn
[MAX_NUMNODES
];
132 #endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
133 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
135 #ifdef CONFIG_DEBUG_VM
136 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
140 unsigned long pfn
= page_to_pfn(page
);
143 seq
= zone_span_seqbegin(zone
);
144 if (pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
146 else if (pfn
< zone
->zone_start_pfn
)
148 } while (zone_span_seqretry(zone
, seq
));
153 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
155 #ifdef CONFIG_HOLES_IN_ZONE
156 if (!pfn_valid(page_to_pfn(page
)))
159 if (zone
!= page_zone(page
))
165 * Temporary debugging check for pages not lying within a given zone.
167 static int bad_range(struct zone
*zone
, struct page
*page
)
169 if (page_outside_zone_boundaries(zone
, page
))
171 if (!page_is_consistent(zone
, page
))
177 static inline int bad_range(struct zone
*zone
, struct page
*page
)
183 static void bad_page(struct page
*page
)
185 printk(KERN_EMERG
"Bad page state in process '%s'\n"
186 KERN_EMERG
"page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n"
187 KERN_EMERG
"Trying to fix it up, but a reboot is needed\n"
188 KERN_EMERG
"Backtrace:\n",
189 current
->comm
, page
, (int)(2*sizeof(unsigned long)),
190 (unsigned long)page
->flags
, page
->mapping
,
191 page_mapcount(page
), page_count(page
));
193 page
->flags
&= ~(1 << PG_lru
|
203 set_page_count(page
, 0);
204 reset_page_mapcount(page
);
205 page
->mapping
= NULL
;
206 add_taint(TAINT_BAD_PAGE
);
210 * Higher-order pages are called "compound pages". They are structured thusly:
212 * The first PAGE_SIZE page is called the "head page".
214 * The remaining PAGE_SIZE pages are called "tail pages".
216 * All pages have PG_compound set. All pages have their ->private pointing at
217 * the head page (even the head page has this).
219 * The first tail page's ->lru.next holds the address of the compound page's
220 * put_page() function. Its ->lru.prev holds the order of allocation.
221 * This usage means that zero-order pages may not be compound.
224 static void free_compound_page(struct page
*page
)
226 __free_pages_ok(page
, (unsigned long)page
[1].lru
.prev
);
229 static void prep_compound_page(struct page
*page
, unsigned long order
)
232 int nr_pages
= 1 << order
;
234 set_compound_page_dtor(page
, free_compound_page
);
235 page
[1].lru
.prev
= (void *)order
;
236 for (i
= 0; i
< nr_pages
; i
++) {
237 struct page
*p
= page
+ i
;
239 __SetPageCompound(p
);
240 set_page_private(p
, (unsigned long)page
);
244 static void destroy_compound_page(struct page
*page
, unsigned long order
)
247 int nr_pages
= 1 << order
;
249 if (unlikely((unsigned long)page
[1].lru
.prev
!= order
))
252 for (i
= 0; i
< nr_pages
; i
++) {
253 struct page
*p
= page
+ i
;
255 if (unlikely(!PageCompound(p
) |
256 (page_private(p
) != (unsigned long)page
)))
258 __ClearPageCompound(p
);
262 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
266 VM_BUG_ON((gfp_flags
& (__GFP_WAIT
| __GFP_HIGHMEM
)) == __GFP_HIGHMEM
);
268 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
269 * and __GFP_HIGHMEM from hard or soft interrupt context.
271 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
272 for (i
= 0; i
< (1 << order
); i
++)
273 clear_highpage(page
+ i
);
277 * function for dealing with page's order in buddy system.
278 * zone->lock is already acquired when we use these.
279 * So, we don't need atomic page->flags operations here.
281 static inline unsigned long page_order(struct page
*page
)
283 return page_private(page
);
286 static inline void set_page_order(struct page
*page
, int order
)
288 set_page_private(page
, order
);
289 __SetPageBuddy(page
);
292 static inline void rmv_page_order(struct page
*page
)
294 __ClearPageBuddy(page
);
295 set_page_private(page
, 0);
299 * Locate the struct page for both the matching buddy in our
300 * pair (buddy1) and the combined O(n+1) page they form (page).
302 * 1) Any buddy B1 will have an order O twin B2 which satisfies
303 * the following equation:
305 * For example, if the starting buddy (buddy2) is #8 its order
307 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
309 * 2) Any buddy B will have an order O+1 parent P which
310 * satisfies the following equation:
313 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
315 static inline struct page
*
316 __page_find_buddy(struct page
*page
, unsigned long page_idx
, unsigned int order
)
318 unsigned long buddy_idx
= page_idx
^ (1 << order
);
320 return page
+ (buddy_idx
- page_idx
);
323 static inline unsigned long
324 __find_combined_index(unsigned long page_idx
, unsigned int order
)
326 return (page_idx
& ~(1 << order
));
330 * This function checks whether a page is free && is the buddy
331 * we can do coalesce a page and its buddy if
332 * (a) the buddy is not in a hole &&
333 * (b) the buddy is in the buddy system &&
334 * (c) a page and its buddy have the same order &&
335 * (d) a page and its buddy are in the same zone.
337 * For recording whether a page is in the buddy system, we use PG_buddy.
338 * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
340 * For recording page's order, we use page_private(page).
342 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
345 #ifdef CONFIG_HOLES_IN_ZONE
346 if (!pfn_valid(page_to_pfn(buddy
)))
350 if (page_zone_id(page
) != page_zone_id(buddy
))
353 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
354 BUG_ON(page_count(buddy
) != 0);
361 * Freeing function for a buddy system allocator.
363 * The concept of a buddy system is to maintain direct-mapped table
364 * (containing bit values) for memory blocks of various "orders".
365 * The bottom level table contains the map for the smallest allocatable
366 * units of memory (here, pages), and each level above it describes
367 * pairs of units from the levels below, hence, "buddies".
368 * At a high level, all that happens here is marking the table entry
369 * at the bottom level available, and propagating the changes upward
370 * as necessary, plus some accounting needed to play nicely with other
371 * parts of the VM system.
372 * At each level, we keep a list of pages, which are heads of continuous
373 * free pages of length of (1 << order) and marked with PG_buddy. Page's
374 * order is recorded in page_private(page) field.
375 * So when we are allocating or freeing one, we can derive the state of the
376 * other. That is, if we allocate a small block, and both were
377 * free, the remainder of the region must be split into blocks.
378 * If a block is freed, and its buddy is also free, then this
379 * triggers coalescing into a block of larger size.
384 static inline void __free_one_page(struct page
*page
,
385 struct zone
*zone
, unsigned int order
)
387 unsigned long page_idx
;
388 int order_size
= 1 << order
;
390 if (unlikely(PageCompound(page
)))
391 destroy_compound_page(page
, order
);
393 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
395 VM_BUG_ON(page_idx
& (order_size
- 1));
396 VM_BUG_ON(bad_range(zone
, page
));
398 zone
->free_pages
+= order_size
;
399 while (order
< MAX_ORDER
-1) {
400 unsigned long combined_idx
;
401 struct free_area
*area
;
404 buddy
= __page_find_buddy(page
, page_idx
, order
);
405 if (!page_is_buddy(page
, buddy
, order
))
406 break; /* Move the buddy up one level. */
408 list_del(&buddy
->lru
);
409 area
= zone
->free_area
+ order
;
411 rmv_page_order(buddy
);
412 combined_idx
= __find_combined_index(page_idx
, order
);
413 page
= page
+ (combined_idx
- page_idx
);
414 page_idx
= combined_idx
;
417 set_page_order(page
, order
);
418 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
);
419 zone
->free_area
[order
].nr_free
++;
422 static inline int free_pages_check(struct page
*page
)
424 if (unlikely(page_mapcount(page
) |
425 (page
->mapping
!= NULL
) |
426 (page_count(page
) != 0) |
440 __ClearPageDirty(page
);
442 * For now, we report if PG_reserved was found set, but do not
443 * clear it, and do not free the page. But we shall soon need
444 * to do more, for when the ZERO_PAGE count wraps negative.
446 return PageReserved(page
);
450 * Frees a list of pages.
451 * Assumes all pages on list are in same zone, and of same order.
452 * count is the number of pages to free.
454 * If the zone was previously in an "all pages pinned" state then look to
455 * see if this freeing clears that state.
457 * And clear the zone's pages_scanned counter, to hold off the "all pages are
458 * pinned" detection logic.
460 static void free_pages_bulk(struct zone
*zone
, int count
,
461 struct list_head
*list
, int order
)
463 spin_lock(&zone
->lock
);
464 zone
->all_unreclaimable
= 0;
465 zone
->pages_scanned
= 0;
469 VM_BUG_ON(list_empty(list
));
470 page
= list_entry(list
->prev
, struct page
, lru
);
471 /* have to delete it as __free_one_page list manipulates */
472 list_del(&page
->lru
);
473 __free_one_page(page
, zone
, order
);
475 spin_unlock(&zone
->lock
);
478 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
)
480 spin_lock(&zone
->lock
);
481 zone
->all_unreclaimable
= 0;
482 zone
->pages_scanned
= 0;
483 __free_one_page(page
, zone
, order
);
484 spin_unlock(&zone
->lock
);
487 static void __free_pages_ok(struct page
*page
, unsigned int order
)
493 for (i
= 0 ; i
< (1 << order
) ; ++i
)
494 reserved
+= free_pages_check(page
+ i
);
498 if (!PageHighMem(page
))
499 debug_check_no_locks_freed(page_address(page
),PAGE_SIZE
<<order
);
500 arch_free_page(page
, order
);
501 kernel_map_pages(page
, 1 << order
, 0);
503 local_irq_save(flags
);
504 __count_vm_events(PGFREE
, 1 << order
);
505 free_one_page(page_zone(page
), page
, order
);
506 local_irq_restore(flags
);
510 * permit the bootmem allocator to evade page validation on high-order frees
512 void fastcall __init
__free_pages_bootmem(struct page
*page
, unsigned int order
)
515 __ClearPageReserved(page
);
516 set_page_count(page
, 0);
517 set_page_refcounted(page
);
523 for (loop
= 0; loop
< BITS_PER_LONG
; loop
++) {
524 struct page
*p
= &page
[loop
];
526 if (loop
+ 1 < BITS_PER_LONG
)
528 __ClearPageReserved(p
);
529 set_page_count(p
, 0);
532 set_page_refcounted(page
);
533 __free_pages(page
, order
);
539 * The order of subdivision here is critical for the IO subsystem.
540 * Please do not alter this order without good reasons and regression
541 * testing. Specifically, as large blocks of memory are subdivided,
542 * the order in which smaller blocks are delivered depends on the order
543 * they're subdivided in this function. This is the primary factor
544 * influencing the order in which pages are delivered to the IO
545 * subsystem according to empirical testing, and this is also justified
546 * by considering the behavior of a buddy system containing a single
547 * large block of memory acted on by a series of small allocations.
548 * This behavior is a critical factor in sglist merging's success.
552 static inline void expand(struct zone
*zone
, struct page
*page
,
553 int low
, int high
, struct free_area
*area
)
555 unsigned long size
= 1 << high
;
561 VM_BUG_ON(bad_range(zone
, &page
[size
]));
562 list_add(&page
[size
].lru
, &area
->free_list
);
564 set_page_order(&page
[size
], high
);
569 * This page is about to be returned from the page allocator
571 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
573 if (unlikely(page_mapcount(page
) |
574 (page
->mapping
!= NULL
) |
575 (page_count(page
) != 0) |
591 * For now, we report if PG_reserved was found set, but do not
592 * clear it, and do not allocate the page: as a safety net.
594 if (PageReserved(page
))
597 page
->flags
&= ~(1 << PG_uptodate
| 1 << PG_error
|
598 1 << PG_referenced
| 1 << PG_arch_1
|
599 1 << PG_checked
| 1 << PG_mappedtodisk
);
600 set_page_private(page
, 0);
601 set_page_refcounted(page
);
603 arch_alloc_page(page
, order
);
604 kernel_map_pages(page
, 1 << order
, 1);
606 if (gfp_flags
& __GFP_ZERO
)
607 prep_zero_page(page
, order
, gfp_flags
);
609 if (order
&& (gfp_flags
& __GFP_COMP
))
610 prep_compound_page(page
, order
);
616 * Do the hard work of removing an element from the buddy allocator.
617 * Call me with the zone->lock already held.
619 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
)
621 struct free_area
* area
;
622 unsigned int current_order
;
625 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
626 area
= zone
->free_area
+ current_order
;
627 if (list_empty(&area
->free_list
))
630 page
= list_entry(area
->free_list
.next
, struct page
, lru
);
631 list_del(&page
->lru
);
632 rmv_page_order(page
);
634 zone
->free_pages
-= 1UL << order
;
635 expand(zone
, page
, order
, current_order
, area
);
643 * Obtain a specified number of elements from the buddy allocator, all under
644 * a single hold of the lock, for efficiency. Add them to the supplied list.
645 * Returns the number of new pages which were placed at *list.
647 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
648 unsigned long count
, struct list_head
*list
)
652 spin_lock(&zone
->lock
);
653 for (i
= 0; i
< count
; ++i
) {
654 struct page
*page
= __rmqueue(zone
, order
);
655 if (unlikely(page
== NULL
))
657 list_add_tail(&page
->lru
, list
);
659 spin_unlock(&zone
->lock
);
665 * Called from the slab reaper to drain pagesets on a particular node that
666 * belongs to the currently executing processor.
667 * Note that this function must be called with the thread pinned to
668 * a single processor.
670 void drain_node_pages(int nodeid
)
676 for (z
= 0; z
< MAX_NR_ZONES
; z
++) {
677 struct zone
*zone
= NODE_DATA(nodeid
)->node_zones
+ z
;
678 struct per_cpu_pageset
*pset
;
680 if (!populated_zone(zone
))
683 pset
= zone_pcp(zone
, smp_processor_id());
684 for (i
= 0; i
< ARRAY_SIZE(pset
->pcp
); i
++) {
685 struct per_cpu_pages
*pcp
;
691 local_irq_save(flags
);
692 if (pcp
->count
>= pcp
->batch
)
693 to_drain
= pcp
->batch
;
695 to_drain
= pcp
->count
;
696 free_pages_bulk(zone
, to_drain
, &pcp
->list
, 0);
697 pcp
->count
-= to_drain
;
698 local_irq_restore(flags
);
705 static void __drain_pages(unsigned int cpu
)
711 for_each_zone(zone
) {
712 struct per_cpu_pageset
*pset
;
714 if (!populated_zone(zone
))
717 pset
= zone_pcp(zone
, cpu
);
718 for (i
= 0; i
< ARRAY_SIZE(pset
->pcp
); i
++) {
719 struct per_cpu_pages
*pcp
;
722 local_irq_save(flags
);
723 free_pages_bulk(zone
, pcp
->count
, &pcp
->list
, 0);
725 local_irq_restore(flags
);
732 void mark_free_pages(struct zone
*zone
)
734 unsigned long pfn
, max_zone_pfn
;
737 struct list_head
*curr
;
739 if (!zone
->spanned_pages
)
742 spin_lock_irqsave(&zone
->lock
, flags
);
744 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
745 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
746 if (pfn_valid(pfn
)) {
747 struct page
*page
= pfn_to_page(pfn
);
749 if (!PageNosave(page
))
750 ClearPageNosaveFree(page
);
753 for (order
= MAX_ORDER
- 1; order
>= 0; --order
)
754 list_for_each(curr
, &zone
->free_area
[order
].free_list
) {
757 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
758 for (i
= 0; i
< (1UL << order
); i
++)
759 SetPageNosaveFree(pfn_to_page(pfn
+ i
));
762 spin_unlock_irqrestore(&zone
->lock
, flags
);
766 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
768 void drain_local_pages(void)
772 local_irq_save(flags
);
773 __drain_pages(smp_processor_id());
774 local_irq_restore(flags
);
776 #endif /* CONFIG_PM */
779 * Free a 0-order page
781 static void fastcall
free_hot_cold_page(struct page
*page
, int cold
)
783 struct zone
*zone
= page_zone(page
);
784 struct per_cpu_pages
*pcp
;
788 page
->mapping
= NULL
;
789 if (free_pages_check(page
))
792 if (!PageHighMem(page
))
793 debug_check_no_locks_freed(page_address(page
), PAGE_SIZE
);
794 arch_free_page(page
, 0);
795 kernel_map_pages(page
, 1, 0);
797 pcp
= &zone_pcp(zone
, get_cpu())->pcp
[cold
];
798 local_irq_save(flags
);
799 __count_vm_event(PGFREE
);
800 list_add(&page
->lru
, &pcp
->list
);
802 if (pcp
->count
>= pcp
->high
) {
803 free_pages_bulk(zone
, pcp
->batch
, &pcp
->list
, 0);
804 pcp
->count
-= pcp
->batch
;
806 local_irq_restore(flags
);
810 void fastcall
free_hot_page(struct page
*page
)
812 free_hot_cold_page(page
, 0);
815 void fastcall
free_cold_page(struct page
*page
)
817 free_hot_cold_page(page
, 1);
821 * split_page takes a non-compound higher-order page, and splits it into
822 * n (1<<order) sub-pages: page[0..n]
823 * Each sub-page must be freed individually.
825 * Note: this is probably too low level an operation for use in drivers.
826 * Please consult with lkml before using this in your driver.
828 void split_page(struct page
*page
, unsigned int order
)
832 VM_BUG_ON(PageCompound(page
));
833 VM_BUG_ON(!page_count(page
));
834 for (i
= 1; i
< (1 << order
); i
++)
835 set_page_refcounted(page
+ i
);
839 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
840 * we cheat by calling it from here, in the order > 0 path. Saves a branch
843 static struct page
*buffered_rmqueue(struct zonelist
*zonelist
,
844 struct zone
*zone
, int order
, gfp_t gfp_flags
)
848 int cold
= !!(gfp_flags
& __GFP_COLD
);
853 if (likely(order
== 0)) {
854 struct per_cpu_pages
*pcp
;
856 pcp
= &zone_pcp(zone
, cpu
)->pcp
[cold
];
857 local_irq_save(flags
);
859 pcp
->count
= rmqueue_bulk(zone
, 0,
860 pcp
->batch
, &pcp
->list
);
861 if (unlikely(!pcp
->count
))
864 page
= list_entry(pcp
->list
.next
, struct page
, lru
);
865 list_del(&page
->lru
);
868 spin_lock_irqsave(&zone
->lock
, flags
);
869 page
= __rmqueue(zone
, order
);
870 spin_unlock(&zone
->lock
);
875 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
876 zone_statistics(zonelist
, zone
);
877 local_irq_restore(flags
);
880 VM_BUG_ON(bad_range(zone
, page
));
881 if (prep_new_page(page
, order
, gfp_flags
))
886 local_irq_restore(flags
);
891 #define ALLOC_NO_WATERMARKS 0x01 /* don't check watermarks at all */
892 #define ALLOC_WMARK_MIN 0x02 /* use pages_min watermark */
893 #define ALLOC_WMARK_LOW 0x04 /* use pages_low watermark */
894 #define ALLOC_WMARK_HIGH 0x08 /* use pages_high watermark */
895 #define ALLOC_HARDER 0x10 /* try to alloc harder */
896 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
897 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
899 #ifdef CONFIG_FAIL_PAGE_ALLOC
901 static struct fail_page_alloc_attr
{
902 struct fault_attr attr
;
904 u32 ignore_gfp_highmem
;
907 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
909 struct dentry
*ignore_gfp_highmem_file
;
910 struct dentry
*ignore_gfp_wait_file
;
912 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
914 } fail_page_alloc
= {
915 .attr
= FAULT_ATTR_INITIALIZER
,
916 .ignore_gfp_wait
= 1,
917 .ignore_gfp_highmem
= 1,
920 static int __init
setup_fail_page_alloc(char *str
)
922 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
924 __setup("fail_page_alloc=", setup_fail_page_alloc
);
926 static int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
928 if (gfp_mask
& __GFP_NOFAIL
)
930 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
932 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
935 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
938 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
940 static int __init
fail_page_alloc_debugfs(void)
942 mode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
946 err
= init_fault_attr_dentries(&fail_page_alloc
.attr
,
950 dir
= fail_page_alloc
.attr
.dentries
.dir
;
952 fail_page_alloc
.ignore_gfp_wait_file
=
953 debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
954 &fail_page_alloc
.ignore_gfp_wait
);
956 fail_page_alloc
.ignore_gfp_highmem_file
=
957 debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
958 &fail_page_alloc
.ignore_gfp_highmem
);
960 if (!fail_page_alloc
.ignore_gfp_wait_file
||
961 !fail_page_alloc
.ignore_gfp_highmem_file
) {
963 debugfs_remove(fail_page_alloc
.ignore_gfp_wait_file
);
964 debugfs_remove(fail_page_alloc
.ignore_gfp_highmem_file
);
965 cleanup_fault_attr_dentries(&fail_page_alloc
.attr
);
971 late_initcall(fail_page_alloc_debugfs
);
973 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
975 #else /* CONFIG_FAIL_PAGE_ALLOC */
977 static inline int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
982 #endif /* CONFIG_FAIL_PAGE_ALLOC */
985 * Return 1 if free pages are above 'mark'. This takes into account the order
988 int zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
989 int classzone_idx
, int alloc_flags
)
991 /* free_pages my go negative - that's OK */
992 unsigned long min
= mark
;
993 long free_pages
= z
->free_pages
- (1 << order
) + 1;
996 if (alloc_flags
& ALLOC_HIGH
)
998 if (alloc_flags
& ALLOC_HARDER
)
1001 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
1003 for (o
= 0; o
< order
; o
++) {
1004 /* At the next order, this order's pages become unavailable */
1005 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1007 /* Require fewer higher order pages to be free */
1010 if (free_pages
<= min
)
1018 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1019 * skip over zones that are not allowed by the cpuset, or that have
1020 * been recently (in last second) found to be nearly full. See further
1021 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1022 * that have to skip over alot of full or unallowed zones.
1024 * If the zonelist cache is present in the passed in zonelist, then
1025 * returns a pointer to the allowed node mask (either the current
1026 * tasks mems_allowed, or node_online_map.)
1028 * If the zonelist cache is not available for this zonelist, does
1029 * nothing and returns NULL.
1031 * If the fullzones BITMAP in the zonelist cache is stale (more than
1032 * a second since last zap'd) then we zap it out (clear its bits.)
1034 * We hold off even calling zlc_setup, until after we've checked the
1035 * first zone in the zonelist, on the theory that most allocations will
1036 * be satisfied from that first zone, so best to examine that zone as
1037 * quickly as we can.
1039 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1041 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1042 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1044 zlc
= zonelist
->zlcache_ptr
;
1048 if (jiffies
- zlc
->last_full_zap
> 1 * HZ
) {
1049 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1050 zlc
->last_full_zap
= jiffies
;
1053 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1054 &cpuset_current_mems_allowed
:
1056 return allowednodes
;
1060 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1061 * if it is worth looking at further for free memory:
1062 * 1) Check that the zone isn't thought to be full (doesn't have its
1063 * bit set in the zonelist_cache fullzones BITMAP).
1064 * 2) Check that the zones node (obtained from the zonelist_cache
1065 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1066 * Return true (non-zero) if zone is worth looking at further, or
1067 * else return false (zero) if it is not.
1069 * This check -ignores- the distinction between various watermarks,
1070 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1071 * found to be full for any variation of these watermarks, it will
1072 * be considered full for up to one second by all requests, unless
1073 * we are so low on memory on all allowed nodes that we are forced
1074 * into the second scan of the zonelist.
1076 * In the second scan we ignore this zonelist cache and exactly
1077 * apply the watermarks to all zones, even it is slower to do so.
1078 * We are low on memory in the second scan, and should leave no stone
1079 * unturned looking for a free page.
1081 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zone
**z
,
1082 nodemask_t
*allowednodes
)
1084 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1085 int i
; /* index of *z in zonelist zones */
1086 int n
; /* node that zone *z is on */
1088 zlc
= zonelist
->zlcache_ptr
;
1092 i
= z
- zonelist
->zones
;
1095 /* This zone is worth trying if it is allowed but not full */
1096 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1100 * Given 'z' scanning a zonelist, set the corresponding bit in
1101 * zlc->fullzones, so that subsequent attempts to allocate a page
1102 * from that zone don't waste time re-examining it.
1104 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zone
**z
)
1106 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1107 int i
; /* index of *z in zonelist zones */
1109 zlc
= zonelist
->zlcache_ptr
;
1113 i
= z
- zonelist
->zones
;
1115 set_bit(i
, zlc
->fullzones
);
1118 #else /* CONFIG_NUMA */
1120 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1125 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zone
**z
,
1126 nodemask_t
*allowednodes
)
1131 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zone
**z
)
1134 #endif /* CONFIG_NUMA */
1137 * get_page_from_freelist goes through the zonelist trying to allocate
1140 static struct page
*
1141 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
,
1142 struct zonelist
*zonelist
, int alloc_flags
)
1145 struct page
*page
= NULL
;
1146 int classzone_idx
= zone_idx(zonelist
->zones
[0]);
1148 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1149 int zlc_active
= 0; /* set if using zonelist_cache */
1150 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1154 * Scan zonelist, looking for a zone with enough free.
1155 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1157 z
= zonelist
->zones
;
1160 if (NUMA_BUILD
&& zlc_active
&&
1161 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1164 if (unlikely(NUMA_BUILD
&& (gfp_mask
& __GFP_THISNODE
) &&
1165 zone
->zone_pgdat
!= zonelist
->zones
[0]->zone_pgdat
))
1167 if ((alloc_flags
& ALLOC_CPUSET
) &&
1168 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1171 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
1173 if (alloc_flags
& ALLOC_WMARK_MIN
)
1174 mark
= zone
->pages_min
;
1175 else if (alloc_flags
& ALLOC_WMARK_LOW
)
1176 mark
= zone
->pages_low
;
1178 mark
= zone
->pages_high
;
1179 if (!zone_watermark_ok(zone
, order
, mark
,
1180 classzone_idx
, alloc_flags
)) {
1181 if (!zone_reclaim_mode
||
1182 !zone_reclaim(zone
, gfp_mask
, order
))
1183 goto this_zone_full
;
1187 page
= buffered_rmqueue(zonelist
, zone
, order
, gfp_mask
);
1192 zlc_mark_zone_full(zonelist
, z
);
1194 if (NUMA_BUILD
&& !did_zlc_setup
) {
1195 /* we do zlc_setup after the first zone is tried */
1196 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1200 } while (*(++z
) != NULL
);
1202 if (unlikely(NUMA_BUILD
&& page
== NULL
&& zlc_active
)) {
1203 /* Disable zlc cache for second zonelist scan */
1211 * This is the 'heart' of the zoned buddy allocator.
1213 struct page
* fastcall
1214 __alloc_pages(gfp_t gfp_mask
, unsigned int order
,
1215 struct zonelist
*zonelist
)
1217 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
1220 struct reclaim_state reclaim_state
;
1221 struct task_struct
*p
= current
;
1224 int did_some_progress
;
1226 might_sleep_if(wait
);
1228 if (should_fail_alloc_page(gfp_mask
, order
))
1232 z
= zonelist
->zones
; /* the list of zones suitable for gfp_mask */
1234 if (unlikely(*z
== NULL
)) {
1235 /* Should this ever happen?? */
1239 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, order
,
1240 zonelist
, ALLOC_WMARK_LOW
|ALLOC_CPUSET
);
1245 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
1246 * __GFP_NOWARN set) should not cause reclaim since the subsystem
1247 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
1248 * using a larger set of nodes after it has established that the
1249 * allowed per node queues are empty and that nodes are
1252 if (NUMA_BUILD
&& (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
1255 for (z
= zonelist
->zones
; *z
; z
++)
1256 wakeup_kswapd(*z
, order
);
1259 * OK, we're below the kswapd watermark and have kicked background
1260 * reclaim. Now things get more complex, so set up alloc_flags according
1261 * to how we want to proceed.
1263 * The caller may dip into page reserves a bit more if the caller
1264 * cannot run direct reclaim, or if the caller has realtime scheduling
1265 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
1266 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1268 alloc_flags
= ALLOC_WMARK_MIN
;
1269 if ((unlikely(rt_task(p
)) && !in_interrupt()) || !wait
)
1270 alloc_flags
|= ALLOC_HARDER
;
1271 if (gfp_mask
& __GFP_HIGH
)
1272 alloc_flags
|= ALLOC_HIGH
;
1274 alloc_flags
|= ALLOC_CPUSET
;
1277 * Go through the zonelist again. Let __GFP_HIGH and allocations
1278 * coming from realtime tasks go deeper into reserves.
1280 * This is the last chance, in general, before the goto nopage.
1281 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1282 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1284 page
= get_page_from_freelist(gfp_mask
, order
, zonelist
, alloc_flags
);
1288 /* This allocation should allow future memory freeing. */
1291 if (((p
->flags
& PF_MEMALLOC
) || unlikely(test_thread_flag(TIF_MEMDIE
)))
1292 && !in_interrupt()) {
1293 if (!(gfp_mask
& __GFP_NOMEMALLOC
)) {
1295 /* go through the zonelist yet again, ignoring mins */
1296 page
= get_page_from_freelist(gfp_mask
, order
,
1297 zonelist
, ALLOC_NO_WATERMARKS
);
1300 if (gfp_mask
& __GFP_NOFAIL
) {
1301 congestion_wait(WRITE
, HZ
/50);
1308 /* Atomic allocations - we can't balance anything */
1314 /* We now go into synchronous reclaim */
1315 cpuset_memory_pressure_bump();
1316 p
->flags
|= PF_MEMALLOC
;
1317 reclaim_state
.reclaimed_slab
= 0;
1318 p
->reclaim_state
= &reclaim_state
;
1320 did_some_progress
= try_to_free_pages(zonelist
->zones
, gfp_mask
);
1322 p
->reclaim_state
= NULL
;
1323 p
->flags
&= ~PF_MEMALLOC
;
1327 if (likely(did_some_progress
)) {
1328 page
= get_page_from_freelist(gfp_mask
, order
,
1329 zonelist
, alloc_flags
);
1332 } else if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
1334 * Go through the zonelist yet one more time, keep
1335 * very high watermark here, this is only to catch
1336 * a parallel oom killing, we must fail if we're still
1337 * under heavy pressure.
1339 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, order
,
1340 zonelist
, ALLOC_WMARK_HIGH
|ALLOC_CPUSET
);
1344 out_of_memory(zonelist
, gfp_mask
, order
);
1349 * Don't let big-order allocations loop unless the caller explicitly
1350 * requests that. Wait for some write requests to complete then retry.
1352 * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order
1353 * <= 3, but that may not be true in other implementations.
1356 if (!(gfp_mask
& __GFP_NORETRY
)) {
1357 if ((order
<= 3) || (gfp_mask
& __GFP_REPEAT
))
1359 if (gfp_mask
& __GFP_NOFAIL
)
1363 congestion_wait(WRITE
, HZ
/50);
1368 if (!(gfp_mask
& __GFP_NOWARN
) && printk_ratelimit()) {
1369 printk(KERN_WARNING
"%s: page allocation failure."
1370 " order:%d, mode:0x%x\n",
1371 p
->comm
, order
, gfp_mask
);
1379 EXPORT_SYMBOL(__alloc_pages
);
1382 * Common helper functions.
1384 fastcall
unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
1387 page
= alloc_pages(gfp_mask
, order
);
1390 return (unsigned long) page_address(page
);
1393 EXPORT_SYMBOL(__get_free_pages
);
1395 fastcall
unsigned long get_zeroed_page(gfp_t gfp_mask
)
1400 * get_zeroed_page() returns a 32-bit address, which cannot represent
1403 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
1405 page
= alloc_pages(gfp_mask
| __GFP_ZERO
, 0);
1407 return (unsigned long) page_address(page
);
1411 EXPORT_SYMBOL(get_zeroed_page
);
1413 void __pagevec_free(struct pagevec
*pvec
)
1415 int i
= pagevec_count(pvec
);
1418 free_hot_cold_page(pvec
->pages
[i
], pvec
->cold
);
1421 fastcall
void __free_pages(struct page
*page
, unsigned int order
)
1423 if (put_page_testzero(page
)) {
1425 free_hot_page(page
);
1427 __free_pages_ok(page
, order
);
1431 EXPORT_SYMBOL(__free_pages
);
1433 fastcall
void free_pages(unsigned long addr
, unsigned int order
)
1436 VM_BUG_ON(!virt_addr_valid((void *)addr
));
1437 __free_pages(virt_to_page((void *)addr
), order
);
1441 EXPORT_SYMBOL(free_pages
);
1444 * Total amount of free (allocatable) RAM:
1446 unsigned int nr_free_pages(void)
1448 unsigned int sum
= 0;
1452 sum
+= zone
->free_pages
;
1457 EXPORT_SYMBOL(nr_free_pages
);
1460 unsigned int nr_free_pages_pgdat(pg_data_t
*pgdat
)
1462 unsigned int sum
= 0;
1465 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
1466 sum
+= pgdat
->node_zones
[i
].free_pages
;
1472 static unsigned int nr_free_zone_pages(int offset
)
1474 /* Just pick one node, since fallback list is circular */
1475 pg_data_t
*pgdat
= NODE_DATA(numa_node_id());
1476 unsigned int sum
= 0;
1478 struct zonelist
*zonelist
= pgdat
->node_zonelists
+ offset
;
1479 struct zone
**zonep
= zonelist
->zones
;
1482 for (zone
= *zonep
++; zone
; zone
= *zonep
++) {
1483 unsigned long size
= zone
->present_pages
;
1484 unsigned long high
= zone
->pages_high
;
1493 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
1495 unsigned int nr_free_buffer_pages(void)
1497 return nr_free_zone_pages(gfp_zone(GFP_USER
));
1501 * Amount of free RAM allocatable within all zones
1503 unsigned int nr_free_pagecache_pages(void)
1505 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER
));
1508 static inline void show_node(struct zone
*zone
)
1511 printk("Node %d ", zone_to_nid(zone
));
1514 void si_meminfo(struct sysinfo
*val
)
1516 val
->totalram
= totalram_pages
;
1518 val
->freeram
= nr_free_pages();
1519 val
->bufferram
= nr_blockdev_pages();
1520 val
->totalhigh
= totalhigh_pages
;
1521 val
->freehigh
= nr_free_highpages();
1522 val
->mem_unit
= PAGE_SIZE
;
1525 EXPORT_SYMBOL(si_meminfo
);
1528 void si_meminfo_node(struct sysinfo
*val
, int nid
)
1530 pg_data_t
*pgdat
= NODE_DATA(nid
);
1532 val
->totalram
= pgdat
->node_present_pages
;
1533 val
->freeram
= nr_free_pages_pgdat(pgdat
);
1534 #ifdef CONFIG_HIGHMEM
1535 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
1536 val
->freehigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].free_pages
;
1541 val
->mem_unit
= PAGE_SIZE
;
1545 #define K(x) ((x) << (PAGE_SHIFT-10))
1548 * Show free area list (used inside shift_scroll-lock stuff)
1549 * We also calculate the percentage fragmentation. We do this by counting the
1550 * memory on each free list with the exception of the first item on the list.
1552 void show_free_areas(void)
1555 unsigned long active
;
1556 unsigned long inactive
;
1560 for_each_zone(zone
) {
1561 if (!populated_zone(zone
))
1565 printk("%s per-cpu:\n", zone
->name
);
1567 for_each_online_cpu(cpu
) {
1568 struct per_cpu_pageset
*pageset
;
1570 pageset
= zone_pcp(zone
, cpu
);
1572 printk("CPU %4d: Hot: hi:%5d, btch:%4d usd:%4d "
1573 "Cold: hi:%5d, btch:%4d usd:%4d\n",
1574 cpu
, pageset
->pcp
[0].high
,
1575 pageset
->pcp
[0].batch
, pageset
->pcp
[0].count
,
1576 pageset
->pcp
[1].high
, pageset
->pcp
[1].batch
,
1577 pageset
->pcp
[1].count
);
1581 get_zone_counts(&active
, &inactive
, &free
);
1583 printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu "
1584 "unstable:%lu free:%u slab:%lu mapped:%lu pagetables:%lu\n",
1587 global_page_state(NR_FILE_DIRTY
),
1588 global_page_state(NR_WRITEBACK
),
1589 global_page_state(NR_UNSTABLE_NFS
),
1591 global_page_state(NR_SLAB_RECLAIMABLE
) +
1592 global_page_state(NR_SLAB_UNRECLAIMABLE
),
1593 global_page_state(NR_FILE_MAPPED
),
1594 global_page_state(NR_PAGETABLE
));
1596 for_each_zone(zone
) {
1599 if (!populated_zone(zone
))
1611 " pages_scanned:%lu"
1612 " all_unreclaimable? %s"
1615 K(zone
->free_pages
),
1618 K(zone
->pages_high
),
1620 K(zone
->nr_inactive
),
1621 K(zone
->present_pages
),
1622 zone
->pages_scanned
,
1623 (zone
->all_unreclaimable
? "yes" : "no")
1625 printk("lowmem_reserve[]:");
1626 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
1627 printk(" %lu", zone
->lowmem_reserve
[i
]);
1631 for_each_zone(zone
) {
1632 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
1634 if (!populated_zone(zone
))
1638 printk("%s: ", zone
->name
);
1640 spin_lock_irqsave(&zone
->lock
, flags
);
1641 for (order
= 0; order
< MAX_ORDER
; order
++) {
1642 nr
[order
] = zone
->free_area
[order
].nr_free
;
1643 total
+= nr
[order
] << order
;
1645 spin_unlock_irqrestore(&zone
->lock
, flags
);
1646 for (order
= 0; order
< MAX_ORDER
; order
++)
1647 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
1648 printk("= %lukB\n", K(total
));
1651 show_swap_cache_info();
1655 * Builds allocation fallback zone lists.
1657 * Add all populated zones of a node to the zonelist.
1659 static int __meminit
build_zonelists_node(pg_data_t
*pgdat
,
1660 struct zonelist
*zonelist
, int nr_zones
, enum zone_type zone_type
)
1664 BUG_ON(zone_type
>= MAX_NR_ZONES
);
1669 zone
= pgdat
->node_zones
+ zone_type
;
1670 if (populated_zone(zone
)) {
1671 zonelist
->zones
[nr_zones
++] = zone
;
1672 check_highest_zone(zone_type
);
1675 } while (zone_type
);
1680 #define MAX_NODE_LOAD (num_online_nodes())
1681 static int __meminitdata node_load
[MAX_NUMNODES
];
1683 * find_next_best_node - find the next node that should appear in a given node's fallback list
1684 * @node: node whose fallback list we're appending
1685 * @used_node_mask: nodemask_t of already used nodes
1687 * We use a number of factors to determine which is the next node that should
1688 * appear on a given node's fallback list. The node should not have appeared
1689 * already in @node's fallback list, and it should be the next closest node
1690 * according to the distance array (which contains arbitrary distance values
1691 * from each node to each node in the system), and should also prefer nodes
1692 * with no CPUs, since presumably they'll have very little allocation pressure
1693 * on them otherwise.
1694 * It returns -1 if no node is found.
1696 static int __meminit
find_next_best_node(int node
, nodemask_t
*used_node_mask
)
1699 int min_val
= INT_MAX
;
1702 /* Use the local node if we haven't already */
1703 if (!node_isset(node
, *used_node_mask
)) {
1704 node_set(node
, *used_node_mask
);
1708 for_each_online_node(n
) {
1711 /* Don't want a node to appear more than once */
1712 if (node_isset(n
, *used_node_mask
))
1715 /* Use the distance array to find the distance */
1716 val
= node_distance(node
, n
);
1718 /* Penalize nodes under us ("prefer the next node") */
1721 /* Give preference to headless and unused nodes */
1722 tmp
= node_to_cpumask(n
);
1723 if (!cpus_empty(tmp
))
1724 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
1726 /* Slight preference for less loaded node */
1727 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
1728 val
+= node_load
[n
];
1730 if (val
< min_val
) {
1737 node_set(best_node
, *used_node_mask
);
1742 static void __meminit
build_zonelists(pg_data_t
*pgdat
)
1744 int j
, node
, local_node
;
1746 int prev_node
, load
;
1747 struct zonelist
*zonelist
;
1748 nodemask_t used_mask
;
1750 /* initialize zonelists */
1751 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
1752 zonelist
= pgdat
->node_zonelists
+ i
;
1753 zonelist
->zones
[0] = NULL
;
1756 /* NUMA-aware ordering of nodes */
1757 local_node
= pgdat
->node_id
;
1758 load
= num_online_nodes();
1759 prev_node
= local_node
;
1760 nodes_clear(used_mask
);
1761 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
1762 int distance
= node_distance(local_node
, node
);
1765 * If another node is sufficiently far away then it is better
1766 * to reclaim pages in a zone before going off node.
1768 if (distance
> RECLAIM_DISTANCE
)
1769 zone_reclaim_mode
= 1;
1772 * We don't want to pressure a particular node.
1773 * So adding penalty to the first node in same
1774 * distance group to make it round-robin.
1777 if (distance
!= node_distance(local_node
, prev_node
))
1778 node_load
[node
] += load
;
1781 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
1782 zonelist
= pgdat
->node_zonelists
+ i
;
1783 for (j
= 0; zonelist
->zones
[j
] != NULL
; j
++);
1785 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
, i
);
1786 zonelist
->zones
[j
] = NULL
;
1791 /* Construct the zonelist performance cache - see further mmzone.h */
1792 static void __meminit
build_zonelist_cache(pg_data_t
*pgdat
)
1796 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
1797 struct zonelist
*zonelist
;
1798 struct zonelist_cache
*zlc
;
1801 zonelist
= pgdat
->node_zonelists
+ i
;
1802 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
1803 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1804 for (z
= zonelist
->zones
; *z
; z
++)
1805 zlc
->z_to_n
[z
- zonelist
->zones
] = zone_to_nid(*z
);
1809 #else /* CONFIG_NUMA */
1811 static void __meminit
build_zonelists(pg_data_t
*pgdat
)
1813 int node
, local_node
;
1816 local_node
= pgdat
->node_id
;
1817 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
1818 struct zonelist
*zonelist
;
1820 zonelist
= pgdat
->node_zonelists
+ i
;
1822 j
= build_zonelists_node(pgdat
, zonelist
, 0, i
);
1824 * Now we build the zonelist so that it contains the zones
1825 * of all the other nodes.
1826 * We don't want to pressure a particular node, so when
1827 * building the zones for node N, we make sure that the
1828 * zones coming right after the local ones are those from
1829 * node N+1 (modulo N)
1831 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
1832 if (!node_online(node
))
1834 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
, i
);
1836 for (node
= 0; node
< local_node
; node
++) {
1837 if (!node_online(node
))
1839 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
, i
);
1842 zonelist
->zones
[j
] = NULL
;
1846 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
1847 static void __meminit
build_zonelist_cache(pg_data_t
*pgdat
)
1851 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
1852 pgdat
->node_zonelists
[i
].zlcache_ptr
= NULL
;
1855 #endif /* CONFIG_NUMA */
1857 /* return values int ....just for stop_machine_run() */
1858 static int __meminit
__build_all_zonelists(void *dummy
)
1862 for_each_online_node(nid
) {
1863 build_zonelists(NODE_DATA(nid
));
1864 build_zonelist_cache(NODE_DATA(nid
));
1869 void __meminit
build_all_zonelists(void)
1871 if (system_state
== SYSTEM_BOOTING
) {
1872 __build_all_zonelists(NULL
);
1873 cpuset_init_current_mems_allowed();
1875 /* we have to stop all cpus to guaranntee there is no user
1877 stop_machine_run(__build_all_zonelists
, NULL
, NR_CPUS
);
1878 /* cpuset refresh routine should be here */
1880 vm_total_pages
= nr_free_pagecache_pages();
1881 printk("Built %i zonelists. Total pages: %ld\n",
1882 num_online_nodes(), vm_total_pages
);
1886 * Helper functions to size the waitqueue hash table.
1887 * Essentially these want to choose hash table sizes sufficiently
1888 * large so that collisions trying to wait on pages are rare.
1889 * But in fact, the number of active page waitqueues on typical
1890 * systems is ridiculously low, less than 200. So this is even
1891 * conservative, even though it seems large.
1893 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
1894 * waitqueues, i.e. the size of the waitq table given the number of pages.
1896 #define PAGES_PER_WAITQUEUE 256
1898 #ifndef CONFIG_MEMORY_HOTPLUG
1899 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
1901 unsigned long size
= 1;
1903 pages
/= PAGES_PER_WAITQUEUE
;
1905 while (size
< pages
)
1909 * Once we have dozens or even hundreds of threads sleeping
1910 * on IO we've got bigger problems than wait queue collision.
1911 * Limit the size of the wait table to a reasonable size.
1913 size
= min(size
, 4096UL);
1915 return max(size
, 4UL);
1919 * A zone's size might be changed by hot-add, so it is not possible to determine
1920 * a suitable size for its wait_table. So we use the maximum size now.
1922 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
1924 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
1925 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
1926 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
1928 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
1929 * or more by the traditional way. (See above). It equals:
1931 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
1932 * ia64(16K page size) : = ( 8G + 4M)byte.
1933 * powerpc (64K page size) : = (32G +16M)byte.
1935 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
1942 * This is an integer logarithm so that shifts can be used later
1943 * to extract the more random high bits from the multiplicative
1944 * hash function before the remainder is taken.
1946 static inline unsigned long wait_table_bits(unsigned long size
)
1951 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
1954 * Initially all pages are reserved - free ones are freed
1955 * up by free_all_bootmem() once the early boot process is
1956 * done. Non-atomic initialization, single-pass.
1958 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
1959 unsigned long start_pfn
)
1962 unsigned long end_pfn
= start_pfn
+ size
;
1965 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
1966 if (!early_pfn_valid(pfn
))
1968 if (!early_pfn_in_nid(pfn
, nid
))
1970 page
= pfn_to_page(pfn
);
1971 set_page_links(page
, zone
, nid
, pfn
);
1972 init_page_count(page
);
1973 reset_page_mapcount(page
);
1974 SetPageReserved(page
);
1975 INIT_LIST_HEAD(&page
->lru
);
1976 #ifdef WANT_PAGE_VIRTUAL
1977 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1978 if (!is_highmem_idx(zone
))
1979 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
1984 void zone_init_free_lists(struct pglist_data
*pgdat
, struct zone
*zone
,
1988 for (order
= 0; order
< MAX_ORDER
; order
++) {
1989 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
);
1990 zone
->free_area
[order
].nr_free
= 0;
1994 #ifndef __HAVE_ARCH_MEMMAP_INIT
1995 #define memmap_init(size, nid, zone, start_pfn) \
1996 memmap_init_zone((size), (nid), (zone), (start_pfn))
1999 static int __cpuinit
zone_batchsize(struct zone
*zone
)
2004 * The per-cpu-pages pools are set to around 1000th of the
2005 * size of the zone. But no more than 1/2 of a meg.
2007 * OK, so we don't know how big the cache is. So guess.
2009 batch
= zone
->present_pages
/ 1024;
2010 if (batch
* PAGE_SIZE
> 512 * 1024)
2011 batch
= (512 * 1024) / PAGE_SIZE
;
2012 batch
/= 4; /* We effectively *= 4 below */
2017 * Clamp the batch to a 2^n - 1 value. Having a power
2018 * of 2 value was found to be more likely to have
2019 * suboptimal cache aliasing properties in some cases.
2021 * For example if 2 tasks are alternately allocating
2022 * batches of pages, one task can end up with a lot
2023 * of pages of one half of the possible page colors
2024 * and the other with pages of the other colors.
2026 batch
= (1 << (fls(batch
+ batch
/2)-1)) - 1;
2031 inline void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
2033 struct per_cpu_pages
*pcp
;
2035 memset(p
, 0, sizeof(*p
));
2037 pcp
= &p
->pcp
[0]; /* hot */
2039 pcp
->high
= 6 * batch
;
2040 pcp
->batch
= max(1UL, 1 * batch
);
2041 INIT_LIST_HEAD(&pcp
->list
);
2043 pcp
= &p
->pcp
[1]; /* cold*/
2045 pcp
->high
= 2 * batch
;
2046 pcp
->batch
= max(1UL, batch
/2);
2047 INIT_LIST_HEAD(&pcp
->list
);
2051 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
2052 * to the value high for the pageset p.
2055 static void setup_pagelist_highmark(struct per_cpu_pageset
*p
,
2058 struct per_cpu_pages
*pcp
;
2060 pcp
= &p
->pcp
[0]; /* hot list */
2062 pcp
->batch
= max(1UL, high
/4);
2063 if ((high
/4) > (PAGE_SHIFT
* 8))
2064 pcp
->batch
= PAGE_SHIFT
* 8;
2070 * Boot pageset table. One per cpu which is going to be used for all
2071 * zones and all nodes. The parameters will be set in such a way
2072 * that an item put on a list will immediately be handed over to
2073 * the buddy list. This is safe since pageset manipulation is done
2074 * with interrupts disabled.
2076 * Some NUMA counter updates may also be caught by the boot pagesets.
2078 * The boot_pagesets must be kept even after bootup is complete for
2079 * unused processors and/or zones. They do play a role for bootstrapping
2080 * hotplugged processors.
2082 * zoneinfo_show() and maybe other functions do
2083 * not check if the processor is online before following the pageset pointer.
2084 * Other parts of the kernel may not check if the zone is available.
2086 static struct per_cpu_pageset boot_pageset
[NR_CPUS
];
2089 * Dynamically allocate memory for the
2090 * per cpu pageset array in struct zone.
2092 static int __cpuinit
process_zones(int cpu
)
2094 struct zone
*zone
, *dzone
;
2096 for_each_zone(zone
) {
2098 if (!populated_zone(zone
))
2101 zone_pcp(zone
, cpu
) = kmalloc_node(sizeof(struct per_cpu_pageset
),
2102 GFP_KERNEL
, cpu_to_node(cpu
));
2103 if (!zone_pcp(zone
, cpu
))
2106 setup_pageset(zone_pcp(zone
, cpu
), zone_batchsize(zone
));
2108 if (percpu_pagelist_fraction
)
2109 setup_pagelist_highmark(zone_pcp(zone
, cpu
),
2110 (zone
->present_pages
/ percpu_pagelist_fraction
));
2115 for_each_zone(dzone
) {
2118 kfree(zone_pcp(dzone
, cpu
));
2119 zone_pcp(dzone
, cpu
) = NULL
;
2124 static inline void free_zone_pagesets(int cpu
)
2128 for_each_zone(zone
) {
2129 struct per_cpu_pageset
*pset
= zone_pcp(zone
, cpu
);
2131 /* Free per_cpu_pageset if it is slab allocated */
2132 if (pset
!= &boot_pageset
[cpu
])
2134 zone_pcp(zone
, cpu
) = NULL
;
2138 static int __cpuinit
pageset_cpuup_callback(struct notifier_block
*nfb
,
2139 unsigned long action
,
2142 int cpu
= (long)hcpu
;
2143 int ret
= NOTIFY_OK
;
2146 case CPU_UP_PREPARE
:
2147 if (process_zones(cpu
))
2150 case CPU_UP_CANCELED
:
2152 free_zone_pagesets(cpu
);
2160 static struct notifier_block __cpuinitdata pageset_notifier
=
2161 { &pageset_cpuup_callback
, NULL
, 0 };
2163 void __init
setup_per_cpu_pageset(void)
2167 /* Initialize per_cpu_pageset for cpu 0.
2168 * A cpuup callback will do this for every cpu
2169 * as it comes online
2171 err
= process_zones(smp_processor_id());
2173 register_cpu_notifier(&pageset_notifier
);
2179 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
2182 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
2186 * The per-page waitqueue mechanism uses hashed waitqueues
2189 zone
->wait_table_hash_nr_entries
=
2190 wait_table_hash_nr_entries(zone_size_pages
);
2191 zone
->wait_table_bits
=
2192 wait_table_bits(zone
->wait_table_hash_nr_entries
);
2193 alloc_size
= zone
->wait_table_hash_nr_entries
2194 * sizeof(wait_queue_head_t
);
2196 if (system_state
== SYSTEM_BOOTING
) {
2197 zone
->wait_table
= (wait_queue_head_t
*)
2198 alloc_bootmem_node(pgdat
, alloc_size
);
2201 * This case means that a zone whose size was 0 gets new memory
2202 * via memory hot-add.
2203 * But it may be the case that a new node was hot-added. In
2204 * this case vmalloc() will not be able to use this new node's
2205 * memory - this wait_table must be initialized to use this new
2206 * node itself as well.
2207 * To use this new node's memory, further consideration will be
2210 zone
->wait_table
= (wait_queue_head_t
*)vmalloc(alloc_size
);
2212 if (!zone
->wait_table
)
2215 for(i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
2216 init_waitqueue_head(zone
->wait_table
+ i
);
2221 static __meminit
void zone_pcp_init(struct zone
*zone
)
2224 unsigned long batch
= zone_batchsize(zone
);
2226 for (cpu
= 0; cpu
< NR_CPUS
; cpu
++) {
2228 /* Early boot. Slab allocator not functional yet */
2229 zone_pcp(zone
, cpu
) = &boot_pageset
[cpu
];
2230 setup_pageset(&boot_pageset
[cpu
],0);
2232 setup_pageset(zone_pcp(zone
,cpu
), batch
);
2235 if (zone
->present_pages
)
2236 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%lu\n",
2237 zone
->name
, zone
->present_pages
, batch
);
2240 __meminit
int init_currently_empty_zone(struct zone
*zone
,
2241 unsigned long zone_start_pfn
,
2244 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
2246 ret
= zone_wait_table_init(zone
, size
);
2249 pgdat
->nr_zones
= zone_idx(zone
) + 1;
2251 zone
->zone_start_pfn
= zone_start_pfn
;
2253 memmap_init(size
, pgdat
->node_id
, zone_idx(zone
), zone_start_pfn
);
2255 zone_init_free_lists(pgdat
, zone
, zone
->spanned_pages
);
2260 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
2262 * Basic iterator support. Return the first range of PFNs for a node
2263 * Note: nid == MAX_NUMNODES returns first region regardless of node
2265 static int __init
first_active_region_index_in_nid(int nid
)
2269 for (i
= 0; i
< nr_nodemap_entries
; i
++)
2270 if (nid
== MAX_NUMNODES
|| early_node_map
[i
].nid
== nid
)
2277 * Basic iterator support. Return the next active range of PFNs for a node
2278 * Note: nid == MAX_NUMNODES returns next region regardles of node
2280 static int __init
next_active_region_index_in_nid(int index
, int nid
)
2282 for (index
= index
+ 1; index
< nr_nodemap_entries
; index
++)
2283 if (nid
== MAX_NUMNODES
|| early_node_map
[index
].nid
== nid
)
2289 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
2291 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
2292 * Architectures may implement their own version but if add_active_range()
2293 * was used and there are no special requirements, this is a convenient
2296 int __init
early_pfn_to_nid(unsigned long pfn
)
2300 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
2301 unsigned long start_pfn
= early_node_map
[i
].start_pfn
;
2302 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
2304 if (start_pfn
<= pfn
&& pfn
< end_pfn
)
2305 return early_node_map
[i
].nid
;
2310 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
2312 /* Basic iterator support to walk early_node_map[] */
2313 #define for_each_active_range_index_in_nid(i, nid) \
2314 for (i = first_active_region_index_in_nid(nid); i != -1; \
2315 i = next_active_region_index_in_nid(i, nid))
2318 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
2319 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
2320 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
2322 * If an architecture guarantees that all ranges registered with
2323 * add_active_ranges() contain no holes and may be freed, this
2324 * this function may be used instead of calling free_bootmem() manually.
2326 void __init
free_bootmem_with_active_regions(int nid
,
2327 unsigned long max_low_pfn
)
2331 for_each_active_range_index_in_nid(i
, nid
) {
2332 unsigned long size_pages
= 0;
2333 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
2335 if (early_node_map
[i
].start_pfn
>= max_low_pfn
)
2338 if (end_pfn
> max_low_pfn
)
2339 end_pfn
= max_low_pfn
;
2341 size_pages
= end_pfn
- early_node_map
[i
].start_pfn
;
2342 free_bootmem_node(NODE_DATA(early_node_map
[i
].nid
),
2343 PFN_PHYS(early_node_map
[i
].start_pfn
),
2344 size_pages
<< PAGE_SHIFT
);
2349 * sparse_memory_present_with_active_regions - Call memory_present for each active range
2350 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
2352 * If an architecture guarantees that all ranges registered with
2353 * add_active_ranges() contain no holes and may be freed, this
2354 * function may be used instead of calling memory_present() manually.
2356 void __init
sparse_memory_present_with_active_regions(int nid
)
2360 for_each_active_range_index_in_nid(i
, nid
)
2361 memory_present(early_node_map
[i
].nid
,
2362 early_node_map
[i
].start_pfn
,
2363 early_node_map
[i
].end_pfn
);
2367 * push_node_boundaries - Push node boundaries to at least the requested boundary
2368 * @nid: The nid of the node to push the boundary for
2369 * @start_pfn: The start pfn of the node
2370 * @end_pfn: The end pfn of the node
2372 * In reserve-based hot-add, mem_map is allocated that is unused until hotadd
2373 * time. Specifically, on x86_64, SRAT will report ranges that can potentially
2374 * be hotplugged even though no physical memory exists. This function allows
2375 * an arch to push out the node boundaries so mem_map is allocated that can
2378 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
2379 void __init
push_node_boundaries(unsigned int nid
,
2380 unsigned long start_pfn
, unsigned long end_pfn
)
2382 printk(KERN_DEBUG
"Entering push_node_boundaries(%u, %lu, %lu)\n",
2383 nid
, start_pfn
, end_pfn
);
2385 /* Initialise the boundary for this node if necessary */
2386 if (node_boundary_end_pfn
[nid
] == 0)
2387 node_boundary_start_pfn
[nid
] = -1UL;
2389 /* Update the boundaries */
2390 if (node_boundary_start_pfn
[nid
] > start_pfn
)
2391 node_boundary_start_pfn
[nid
] = start_pfn
;
2392 if (node_boundary_end_pfn
[nid
] < end_pfn
)
2393 node_boundary_end_pfn
[nid
] = end_pfn
;
2396 /* If necessary, push the node boundary out for reserve hotadd */
2397 static void __init
account_node_boundary(unsigned int nid
,
2398 unsigned long *start_pfn
, unsigned long *end_pfn
)
2400 printk(KERN_DEBUG
"Entering account_node_boundary(%u, %lu, %lu)\n",
2401 nid
, *start_pfn
, *end_pfn
);
2403 /* Return if boundary information has not been provided */
2404 if (node_boundary_end_pfn
[nid
] == 0)
2407 /* Check the boundaries and update if necessary */
2408 if (node_boundary_start_pfn
[nid
] < *start_pfn
)
2409 *start_pfn
= node_boundary_start_pfn
[nid
];
2410 if (node_boundary_end_pfn
[nid
] > *end_pfn
)
2411 *end_pfn
= node_boundary_end_pfn
[nid
];
2414 void __init
push_node_boundaries(unsigned int nid
,
2415 unsigned long start_pfn
, unsigned long end_pfn
) {}
2417 static void __init
account_node_boundary(unsigned int nid
,
2418 unsigned long *start_pfn
, unsigned long *end_pfn
) {}
2423 * get_pfn_range_for_nid - Return the start and end page frames for a node
2424 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
2425 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
2426 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
2428 * It returns the start and end page frame of a node based on information
2429 * provided by an arch calling add_active_range(). If called for a node
2430 * with no available memory, a warning is printed and the start and end
2433 void __init
get_pfn_range_for_nid(unsigned int nid
,
2434 unsigned long *start_pfn
, unsigned long *end_pfn
)
2440 for_each_active_range_index_in_nid(i
, nid
) {
2441 *start_pfn
= min(*start_pfn
, early_node_map
[i
].start_pfn
);
2442 *end_pfn
= max(*end_pfn
, early_node_map
[i
].end_pfn
);
2445 if (*start_pfn
== -1UL) {
2446 printk(KERN_WARNING
"Node %u active with no memory\n", nid
);
2450 /* Push the node boundaries out if requested */
2451 account_node_boundary(nid
, start_pfn
, end_pfn
);
2455 * Return the number of pages a zone spans in a node, including holes
2456 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
2458 unsigned long __init
zone_spanned_pages_in_node(int nid
,
2459 unsigned long zone_type
,
2460 unsigned long *ignored
)
2462 unsigned long node_start_pfn
, node_end_pfn
;
2463 unsigned long zone_start_pfn
, zone_end_pfn
;
2465 /* Get the start and end of the node and zone */
2466 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
2467 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
2468 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
2470 /* Check that this node has pages within the zone's required range */
2471 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
2474 /* Move the zone boundaries inside the node if necessary */
2475 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
2476 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
2478 /* Return the spanned pages */
2479 return zone_end_pfn
- zone_start_pfn
;
2483 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
2484 * then all holes in the requested range will be accounted for.
2486 unsigned long __init
__absent_pages_in_range(int nid
,
2487 unsigned long range_start_pfn
,
2488 unsigned long range_end_pfn
)
2491 unsigned long prev_end_pfn
= 0, hole_pages
= 0;
2492 unsigned long start_pfn
;
2494 /* Find the end_pfn of the first active range of pfns in the node */
2495 i
= first_active_region_index_in_nid(nid
);
2499 /* Account for ranges before physical memory on this node */
2500 if (early_node_map
[i
].start_pfn
> range_start_pfn
)
2501 hole_pages
= early_node_map
[i
].start_pfn
- range_start_pfn
;
2503 prev_end_pfn
= early_node_map
[i
].start_pfn
;
2505 /* Find all holes for the zone within the node */
2506 for (; i
!= -1; i
= next_active_region_index_in_nid(i
, nid
)) {
2508 /* No need to continue if prev_end_pfn is outside the zone */
2509 if (prev_end_pfn
>= range_end_pfn
)
2512 /* Make sure the end of the zone is not within the hole */
2513 start_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
2514 prev_end_pfn
= max(prev_end_pfn
, range_start_pfn
);
2516 /* Update the hole size cound and move on */
2517 if (start_pfn
> range_start_pfn
) {
2518 BUG_ON(prev_end_pfn
> start_pfn
);
2519 hole_pages
+= start_pfn
- prev_end_pfn
;
2521 prev_end_pfn
= early_node_map
[i
].end_pfn
;
2524 /* Account for ranges past physical memory on this node */
2525 if (range_end_pfn
> prev_end_pfn
)
2526 hole_pages
+= range_end_pfn
-
2527 max(range_start_pfn
, prev_end_pfn
);
2533 * absent_pages_in_range - Return number of page frames in holes within a range
2534 * @start_pfn: The start PFN to start searching for holes
2535 * @end_pfn: The end PFN to stop searching for holes
2537 * It returns the number of pages frames in memory holes within a range.
2539 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
2540 unsigned long end_pfn
)
2542 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
2545 /* Return the number of page frames in holes in a zone on a node */
2546 unsigned long __init
zone_absent_pages_in_node(int nid
,
2547 unsigned long zone_type
,
2548 unsigned long *ignored
)
2550 unsigned long node_start_pfn
, node_end_pfn
;
2551 unsigned long zone_start_pfn
, zone_end_pfn
;
2553 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
2554 zone_start_pfn
= max(arch_zone_lowest_possible_pfn
[zone_type
],
2556 zone_end_pfn
= min(arch_zone_highest_possible_pfn
[zone_type
],
2559 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
2563 static inline unsigned long zone_spanned_pages_in_node(int nid
,
2564 unsigned long zone_type
,
2565 unsigned long *zones_size
)
2567 return zones_size
[zone_type
];
2570 static inline unsigned long zone_absent_pages_in_node(int nid
,
2571 unsigned long zone_type
,
2572 unsigned long *zholes_size
)
2577 return zholes_size
[zone_type
];
2582 static void __init
calculate_node_totalpages(struct pglist_data
*pgdat
,
2583 unsigned long *zones_size
, unsigned long *zholes_size
)
2585 unsigned long realtotalpages
, totalpages
= 0;
2588 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
2589 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
2591 pgdat
->node_spanned_pages
= totalpages
;
2593 realtotalpages
= totalpages
;
2594 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
2596 zone_absent_pages_in_node(pgdat
->node_id
, i
,
2598 pgdat
->node_present_pages
= realtotalpages
;
2599 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
2604 * Set up the zone data structures:
2605 * - mark all pages reserved
2606 * - mark all memory queues empty
2607 * - clear the memory bitmaps
2609 static void __meminit
free_area_init_core(struct pglist_data
*pgdat
,
2610 unsigned long *zones_size
, unsigned long *zholes_size
)
2613 int nid
= pgdat
->node_id
;
2614 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
2617 pgdat_resize_init(pgdat
);
2618 pgdat
->nr_zones
= 0;
2619 init_waitqueue_head(&pgdat
->kswapd_wait
);
2620 pgdat
->kswapd_max_order
= 0;
2622 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
2623 struct zone
*zone
= pgdat
->node_zones
+ j
;
2624 unsigned long size
, realsize
, memmap_pages
;
2626 size
= zone_spanned_pages_in_node(nid
, j
, zones_size
);
2627 realsize
= size
- zone_absent_pages_in_node(nid
, j
,
2631 * Adjust realsize so that it accounts for how much memory
2632 * is used by this zone for memmap. This affects the watermark
2633 * and per-cpu initialisations
2635 memmap_pages
= (size
* sizeof(struct page
)) >> PAGE_SHIFT
;
2636 if (realsize
>= memmap_pages
) {
2637 realsize
-= memmap_pages
;
2639 " %s zone: %lu pages used for memmap\n",
2640 zone_names
[j
], memmap_pages
);
2643 " %s zone: %lu pages exceeds realsize %lu\n",
2644 zone_names
[j
], memmap_pages
, realsize
);
2646 /* Account for reserved DMA pages */
2647 if (j
== ZONE_DMA
&& realsize
> dma_reserve
) {
2648 realsize
-= dma_reserve
;
2649 printk(KERN_DEBUG
" DMA zone: %lu pages reserved\n",
2653 if (!is_highmem_idx(j
))
2654 nr_kernel_pages
+= realsize
;
2655 nr_all_pages
+= realsize
;
2657 zone
->spanned_pages
= size
;
2658 zone
->present_pages
= realsize
;
2661 zone
->min_unmapped_pages
= (realsize
*sysctl_min_unmapped_ratio
)
2663 zone
->min_slab_pages
= (realsize
* sysctl_min_slab_ratio
) / 100;
2665 zone
->name
= zone_names
[j
];
2666 spin_lock_init(&zone
->lock
);
2667 spin_lock_init(&zone
->lru_lock
);
2668 zone_seqlock_init(zone
);
2669 zone
->zone_pgdat
= pgdat
;
2670 zone
->free_pages
= 0;
2672 zone
->prev_priority
= DEF_PRIORITY
;
2674 zone_pcp_init(zone
);
2675 INIT_LIST_HEAD(&zone
->active_list
);
2676 INIT_LIST_HEAD(&zone
->inactive_list
);
2677 zone
->nr_scan_active
= 0;
2678 zone
->nr_scan_inactive
= 0;
2679 zone
->nr_active
= 0;
2680 zone
->nr_inactive
= 0;
2681 zap_zone_vm_stats(zone
);
2682 atomic_set(&zone
->reclaim_in_progress
, 0);
2686 ret
= init_currently_empty_zone(zone
, zone_start_pfn
, size
);
2688 zone_start_pfn
+= size
;
2692 static void __init
alloc_node_mem_map(struct pglist_data
*pgdat
)
2694 /* Skip empty nodes */
2695 if (!pgdat
->node_spanned_pages
)
2698 #ifdef CONFIG_FLAT_NODE_MEM_MAP
2699 /* ia64 gets its own node_mem_map, before this, without bootmem */
2700 if (!pgdat
->node_mem_map
) {
2701 unsigned long size
, start
, end
;
2705 * The zone's endpoints aren't required to be MAX_ORDER
2706 * aligned but the node_mem_map endpoints must be in order
2707 * for the buddy allocator to function correctly.
2709 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
2710 end
= pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
2711 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
2712 size
= (end
- start
) * sizeof(struct page
);
2713 map
= alloc_remap(pgdat
->node_id
, size
);
2715 map
= alloc_bootmem_node(pgdat
, size
);
2716 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
2718 #ifdef CONFIG_FLATMEM
2720 * With no DISCONTIG, the global mem_map is just set as node 0's
2722 if (pgdat
== NODE_DATA(0)) {
2723 mem_map
= NODE_DATA(0)->node_mem_map
;
2724 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
2725 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
2726 mem_map
-= pgdat
->node_start_pfn
;
2727 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
2730 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
2733 void __meminit
free_area_init_node(int nid
, struct pglist_data
*pgdat
,
2734 unsigned long *zones_size
, unsigned long node_start_pfn
,
2735 unsigned long *zholes_size
)
2737 pgdat
->node_id
= nid
;
2738 pgdat
->node_start_pfn
= node_start_pfn
;
2739 calculate_node_totalpages(pgdat
, zones_size
, zholes_size
);
2741 alloc_node_mem_map(pgdat
);
2743 free_area_init_core(pgdat
, zones_size
, zholes_size
);
2746 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
2748 * add_active_range - Register a range of PFNs backed by physical memory
2749 * @nid: The node ID the range resides on
2750 * @start_pfn: The start PFN of the available physical memory
2751 * @end_pfn: The end PFN of the available physical memory
2753 * These ranges are stored in an early_node_map[] and later used by
2754 * free_area_init_nodes() to calculate zone sizes and holes. If the
2755 * range spans a memory hole, it is up to the architecture to ensure
2756 * the memory is not freed by the bootmem allocator. If possible
2757 * the range being registered will be merged with existing ranges.
2759 void __init
add_active_range(unsigned int nid
, unsigned long start_pfn
,
2760 unsigned long end_pfn
)
2764 printk(KERN_DEBUG
"Entering add_active_range(%d, %lu, %lu) "
2765 "%d entries of %d used\n",
2766 nid
, start_pfn
, end_pfn
,
2767 nr_nodemap_entries
, MAX_ACTIVE_REGIONS
);
2769 /* Merge with existing active regions if possible */
2770 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
2771 if (early_node_map
[i
].nid
!= nid
)
2774 /* Skip if an existing region covers this new one */
2775 if (start_pfn
>= early_node_map
[i
].start_pfn
&&
2776 end_pfn
<= early_node_map
[i
].end_pfn
)
2779 /* Merge forward if suitable */
2780 if (start_pfn
<= early_node_map
[i
].end_pfn
&&
2781 end_pfn
> early_node_map
[i
].end_pfn
) {
2782 early_node_map
[i
].end_pfn
= end_pfn
;
2786 /* Merge backward if suitable */
2787 if (start_pfn
< early_node_map
[i
].end_pfn
&&
2788 end_pfn
>= early_node_map
[i
].start_pfn
) {
2789 early_node_map
[i
].start_pfn
= start_pfn
;
2794 /* Check that early_node_map is large enough */
2795 if (i
>= MAX_ACTIVE_REGIONS
) {
2796 printk(KERN_CRIT
"More than %d memory regions, truncating\n",
2797 MAX_ACTIVE_REGIONS
);
2801 early_node_map
[i
].nid
= nid
;
2802 early_node_map
[i
].start_pfn
= start_pfn
;
2803 early_node_map
[i
].end_pfn
= end_pfn
;
2804 nr_nodemap_entries
= i
+ 1;
2808 * shrink_active_range - Shrink an existing registered range of PFNs
2809 * @nid: The node id the range is on that should be shrunk
2810 * @old_end_pfn: The old end PFN of the range
2811 * @new_end_pfn: The new PFN of the range
2813 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
2814 * The map is kept at the end physical page range that has already been
2815 * registered with add_active_range(). This function allows an arch to shrink
2816 * an existing registered range.
2818 void __init
shrink_active_range(unsigned int nid
, unsigned long old_end_pfn
,
2819 unsigned long new_end_pfn
)
2823 /* Find the old active region end and shrink */
2824 for_each_active_range_index_in_nid(i
, nid
)
2825 if (early_node_map
[i
].end_pfn
== old_end_pfn
) {
2826 early_node_map
[i
].end_pfn
= new_end_pfn
;
2832 * remove_all_active_ranges - Remove all currently registered regions
2834 * During discovery, it may be found that a table like SRAT is invalid
2835 * and an alternative discovery method must be used. This function removes
2836 * all currently registered regions.
2838 void __init
remove_all_active_ranges(void)
2840 memset(early_node_map
, 0, sizeof(early_node_map
));
2841 nr_nodemap_entries
= 0;
2842 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
2843 memset(node_boundary_start_pfn
, 0, sizeof(node_boundary_start_pfn
));
2844 memset(node_boundary_end_pfn
, 0, sizeof(node_boundary_end_pfn
));
2845 #endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
2848 /* Compare two active node_active_regions */
2849 static int __init
cmp_node_active_region(const void *a
, const void *b
)
2851 struct node_active_region
*arange
= (struct node_active_region
*)a
;
2852 struct node_active_region
*brange
= (struct node_active_region
*)b
;
2854 /* Done this way to avoid overflows */
2855 if (arange
->start_pfn
> brange
->start_pfn
)
2857 if (arange
->start_pfn
< brange
->start_pfn
)
2863 /* sort the node_map by start_pfn */
2864 static void __init
sort_node_map(void)
2866 sort(early_node_map
, (size_t)nr_nodemap_entries
,
2867 sizeof(struct node_active_region
),
2868 cmp_node_active_region
, NULL
);
2871 /* Find the lowest pfn for a node. This depends on a sorted early_node_map */
2872 unsigned long __init
find_min_pfn_for_node(unsigned long nid
)
2876 /* Regions in the early_node_map can be in any order */
2879 /* Assuming a sorted map, the first range found has the starting pfn */
2880 for_each_active_range_index_in_nid(i
, nid
)
2881 return early_node_map
[i
].start_pfn
;
2883 printk(KERN_WARNING
"Could not find start_pfn for node %lu\n", nid
);
2888 * find_min_pfn_with_active_regions - Find the minimum PFN registered
2890 * It returns the minimum PFN based on information provided via
2891 * add_active_range().
2893 unsigned long __init
find_min_pfn_with_active_regions(void)
2895 return find_min_pfn_for_node(MAX_NUMNODES
);
2899 * find_max_pfn_with_active_regions - Find the maximum PFN registered
2901 * It returns the maximum PFN based on information provided via
2902 * add_active_range().
2904 unsigned long __init
find_max_pfn_with_active_regions(void)
2907 unsigned long max_pfn
= 0;
2909 for (i
= 0; i
< nr_nodemap_entries
; i
++)
2910 max_pfn
= max(max_pfn
, early_node_map
[i
].end_pfn
);
2916 * free_area_init_nodes - Initialise all pg_data_t and zone data
2917 * @max_zone_pfn: an array of max PFNs for each zone
2919 * This will call free_area_init_node() for each active node in the system.
2920 * Using the page ranges provided by add_active_range(), the size of each
2921 * zone in each node and their holes is calculated. If the maximum PFN
2922 * between two adjacent zones match, it is assumed that the zone is empty.
2923 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
2924 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
2925 * starts where the previous one ended. For example, ZONE_DMA32 starts
2926 * at arch_max_dma_pfn.
2928 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
2933 /* Record where the zone boundaries are */
2934 memset(arch_zone_lowest_possible_pfn
, 0,
2935 sizeof(arch_zone_lowest_possible_pfn
));
2936 memset(arch_zone_highest_possible_pfn
, 0,
2937 sizeof(arch_zone_highest_possible_pfn
));
2938 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
2939 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
2940 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
2941 arch_zone_lowest_possible_pfn
[i
] =
2942 arch_zone_highest_possible_pfn
[i
-1];
2943 arch_zone_highest_possible_pfn
[i
] =
2944 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
2947 /* Print out the zone ranges */
2948 printk("Zone PFN ranges:\n");
2949 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
2950 printk(" %-8s %8lu -> %8lu\n",
2952 arch_zone_lowest_possible_pfn
[i
],
2953 arch_zone_highest_possible_pfn
[i
]);
2955 /* Print out the early_node_map[] */
2956 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries
);
2957 for (i
= 0; i
< nr_nodemap_entries
; i
++)
2958 printk(" %3d: %8lu -> %8lu\n", early_node_map
[i
].nid
,
2959 early_node_map
[i
].start_pfn
,
2960 early_node_map
[i
].end_pfn
);
2962 /* Initialise every node */
2963 for_each_online_node(nid
) {
2964 pg_data_t
*pgdat
= NODE_DATA(nid
);
2965 free_area_init_node(nid
, pgdat
, NULL
,
2966 find_min_pfn_for_node(nid
), NULL
);
2969 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
2972 * set_dma_reserve - set the specified number of pages reserved in the first zone
2973 * @new_dma_reserve: The number of pages to mark reserved
2975 * The per-cpu batchsize and zone watermarks are determined by present_pages.
2976 * In the DMA zone, a significant percentage may be consumed by kernel image
2977 * and other unfreeable allocations which can skew the watermarks badly. This
2978 * function may optionally be used to account for unfreeable pages in the
2979 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
2980 * smaller per-cpu batchsize.
2982 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
2984 dma_reserve
= new_dma_reserve
;
2987 #ifndef CONFIG_NEED_MULTIPLE_NODES
2988 static bootmem_data_t contig_bootmem_data
;
2989 struct pglist_data contig_page_data
= { .bdata
= &contig_bootmem_data
};
2991 EXPORT_SYMBOL(contig_page_data
);
2994 void __init
free_area_init(unsigned long *zones_size
)
2996 free_area_init_node(0, NODE_DATA(0), zones_size
,
2997 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
3000 static int page_alloc_cpu_notify(struct notifier_block
*self
,
3001 unsigned long action
, void *hcpu
)
3003 int cpu
= (unsigned long)hcpu
;
3005 if (action
== CPU_DEAD
) {
3006 local_irq_disable();
3008 vm_events_fold_cpu(cpu
);
3010 refresh_cpu_vm_stats(cpu
);
3015 void __init
page_alloc_init(void)
3017 hotcpu_notifier(page_alloc_cpu_notify
, 0);
3021 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
3022 * or min_free_kbytes changes.
3024 static void calculate_totalreserve_pages(void)
3026 struct pglist_data
*pgdat
;
3027 unsigned long reserve_pages
= 0;
3028 enum zone_type i
, j
;
3030 for_each_online_pgdat(pgdat
) {
3031 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
3032 struct zone
*zone
= pgdat
->node_zones
+ i
;
3033 unsigned long max
= 0;
3035 /* Find valid and maximum lowmem_reserve in the zone */
3036 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
3037 if (zone
->lowmem_reserve
[j
] > max
)
3038 max
= zone
->lowmem_reserve
[j
];
3041 /* we treat pages_high as reserved pages. */
3042 max
+= zone
->pages_high
;
3044 if (max
> zone
->present_pages
)
3045 max
= zone
->present_pages
;
3046 reserve_pages
+= max
;
3049 totalreserve_pages
= reserve_pages
;
3053 * setup_per_zone_lowmem_reserve - called whenever
3054 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
3055 * has a correct pages reserved value, so an adequate number of
3056 * pages are left in the zone after a successful __alloc_pages().
3058 static void setup_per_zone_lowmem_reserve(void)
3060 struct pglist_data
*pgdat
;
3061 enum zone_type j
, idx
;
3063 for_each_online_pgdat(pgdat
) {
3064 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
3065 struct zone
*zone
= pgdat
->node_zones
+ j
;
3066 unsigned long present_pages
= zone
->present_pages
;
3068 zone
->lowmem_reserve
[j
] = 0;
3072 struct zone
*lower_zone
;
3076 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
3077 sysctl_lowmem_reserve_ratio
[idx
] = 1;
3079 lower_zone
= pgdat
->node_zones
+ idx
;
3080 lower_zone
->lowmem_reserve
[j
] = present_pages
/
3081 sysctl_lowmem_reserve_ratio
[idx
];
3082 present_pages
+= lower_zone
->present_pages
;
3087 /* update totalreserve_pages */
3088 calculate_totalreserve_pages();
3092 * setup_per_zone_pages_min - called when min_free_kbytes changes.
3094 * Ensures that the pages_{min,low,high} values for each zone are set correctly
3095 * with respect to min_free_kbytes.
3097 void setup_per_zone_pages_min(void)
3099 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
3100 unsigned long lowmem_pages
= 0;
3102 unsigned long flags
;
3104 /* Calculate total number of !ZONE_HIGHMEM pages */
3105 for_each_zone(zone
) {
3106 if (!is_highmem(zone
))
3107 lowmem_pages
+= zone
->present_pages
;
3110 for_each_zone(zone
) {
3113 spin_lock_irqsave(&zone
->lru_lock
, flags
);
3114 tmp
= (u64
)pages_min
* zone
->present_pages
;
3115 do_div(tmp
, lowmem_pages
);
3116 if (is_highmem(zone
)) {
3118 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
3119 * need highmem pages, so cap pages_min to a small
3122 * The (pages_high-pages_low) and (pages_low-pages_min)
3123 * deltas controls asynch page reclaim, and so should
3124 * not be capped for highmem.
3128 min_pages
= zone
->present_pages
/ 1024;
3129 if (min_pages
< SWAP_CLUSTER_MAX
)
3130 min_pages
= SWAP_CLUSTER_MAX
;
3131 if (min_pages
> 128)
3133 zone
->pages_min
= min_pages
;
3136 * If it's a lowmem zone, reserve a number of pages
3137 * proportionate to the zone's size.
3139 zone
->pages_min
= tmp
;
3142 zone
->pages_low
= zone
->pages_min
+ (tmp
>> 2);
3143 zone
->pages_high
= zone
->pages_min
+ (tmp
>> 1);
3144 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
3147 /* update totalreserve_pages */
3148 calculate_totalreserve_pages();
3152 * Initialise min_free_kbytes.
3154 * For small machines we want it small (128k min). For large machines
3155 * we want it large (64MB max). But it is not linear, because network
3156 * bandwidth does not increase linearly with machine size. We use
3158 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
3159 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
3175 static int __init
init_per_zone_pages_min(void)
3177 unsigned long lowmem_kbytes
;
3179 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
3181 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
3182 if (min_free_kbytes
< 128)
3183 min_free_kbytes
= 128;
3184 if (min_free_kbytes
> 65536)
3185 min_free_kbytes
= 65536;
3186 setup_per_zone_pages_min();
3187 setup_per_zone_lowmem_reserve();
3190 module_init(init_per_zone_pages_min
)
3193 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
3194 * that we can call two helper functions whenever min_free_kbytes
3197 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
3198 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
3200 proc_dointvec(table
, write
, file
, buffer
, length
, ppos
);
3201 setup_per_zone_pages_min();
3206 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
3207 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
3212 rc
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
3217 zone
->min_unmapped_pages
= (zone
->present_pages
*
3218 sysctl_min_unmapped_ratio
) / 100;
3222 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
3223 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
3228 rc
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
3233 zone
->min_slab_pages
= (zone
->present_pages
*
3234 sysctl_min_slab_ratio
) / 100;
3240 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
3241 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
3242 * whenever sysctl_lowmem_reserve_ratio changes.
3244 * The reserve ratio obviously has absolutely no relation with the
3245 * pages_min watermarks. The lowmem reserve ratio can only make sense
3246 * if in function of the boot time zone sizes.
3248 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
3249 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
3251 proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
3252 setup_per_zone_lowmem_reserve();
3257 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
3258 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
3259 * can have before it gets flushed back to buddy allocator.
3262 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
3263 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
3269 ret
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
3270 if (!write
|| (ret
== -EINVAL
))
3272 for_each_zone(zone
) {
3273 for_each_online_cpu(cpu
) {
3275 high
= zone
->present_pages
/ percpu_pagelist_fraction
;
3276 setup_pagelist_highmark(zone_pcp(zone
, cpu
), high
);
3282 int hashdist
= HASHDIST_DEFAULT
;
3285 static int __init
set_hashdist(char *str
)
3289 hashdist
= simple_strtoul(str
, &str
, 0);
3292 __setup("hashdist=", set_hashdist
);
3296 * allocate a large system hash table from bootmem
3297 * - it is assumed that the hash table must contain an exact power-of-2
3298 * quantity of entries
3299 * - limit is the number of hash buckets, not the total allocation size
3301 void *__init
alloc_large_system_hash(const char *tablename
,
3302 unsigned long bucketsize
,
3303 unsigned long numentries
,
3306 unsigned int *_hash_shift
,
3307 unsigned int *_hash_mask
,
3308 unsigned long limit
)
3310 unsigned long long max
= limit
;
3311 unsigned long log2qty
, size
;
3314 /* allow the kernel cmdline to have a say */
3316 /* round applicable memory size up to nearest megabyte */
3317 numentries
= nr_kernel_pages
;
3318 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
3319 numentries
>>= 20 - PAGE_SHIFT
;
3320 numentries
<<= 20 - PAGE_SHIFT
;
3322 /* limit to 1 bucket per 2^scale bytes of low memory */
3323 if (scale
> PAGE_SHIFT
)
3324 numentries
>>= (scale
- PAGE_SHIFT
);
3326 numentries
<<= (PAGE_SHIFT
- scale
);
3328 /* Make sure we've got at least a 0-order allocation.. */
3329 if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
3330 numentries
= PAGE_SIZE
/ bucketsize
;
3332 numentries
= roundup_pow_of_two(numentries
);
3334 /* limit allocation size to 1/16 total memory by default */
3336 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
3337 do_div(max
, bucketsize
);
3340 if (numentries
> max
)
3343 log2qty
= ilog2(numentries
);
3346 size
= bucketsize
<< log2qty
;
3347 if (flags
& HASH_EARLY
)
3348 table
= alloc_bootmem(size
);
3350 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
3352 unsigned long order
;
3353 for (order
= 0; ((1UL << order
) << PAGE_SHIFT
) < size
; order
++)
3355 table
= (void*) __get_free_pages(GFP_ATOMIC
, order
);
3357 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
3360 panic("Failed to allocate %s hash table\n", tablename
);
3362 printk("%s hash table entries: %d (order: %d, %lu bytes)\n",
3365 ilog2(size
) - PAGE_SHIFT
,
3369 *_hash_shift
= log2qty
;
3371 *_hash_mask
= (1 << log2qty
) - 1;
3376 #ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
3377 struct page
*pfn_to_page(unsigned long pfn
)
3379 return __pfn_to_page(pfn
);
3381 unsigned long page_to_pfn(struct page
*page
)
3383 return __page_to_pfn(page
);
3385 EXPORT_SYMBOL(pfn_to_page
);
3386 EXPORT_SYMBOL(page_to_pfn
);
3387 #endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */
3389 #if MAX_NUMNODES > 1
3391 * Find the highest possible node id.
3393 int highest_possible_node_id(void)
3396 unsigned int highest
= 0;
3398 for_each_node_mask(node
, node_possible_map
)
3402 EXPORT_SYMBOL(highest_possible_node_id
);