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>
44 #include <asm/tlbflush.h>
45 #include <asm/div64.h>
49 * MCD - HACK: Find somewhere to initialize this EARLY, or make this
52 nodemask_t node_online_map __read_mostly
= { { [0] = 1UL } };
53 EXPORT_SYMBOL(node_online_map
);
54 nodemask_t node_possible_map __read_mostly
= NODE_MASK_ALL
;
55 EXPORT_SYMBOL(node_possible_map
);
56 unsigned long totalram_pages __read_mostly
;
57 unsigned long totalreserve_pages __read_mostly
;
59 int percpu_pagelist_fraction
;
61 static void __free_pages_ok(struct page
*page
, unsigned int order
);
64 * results with 256, 32 in the lowmem_reserve sysctl:
65 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
66 * 1G machine -> (16M dma, 784M normal, 224M high)
67 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
68 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
69 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
71 * TBD: should special case ZONE_DMA32 machines here - in those we normally
72 * don't need any ZONE_NORMAL reservation
74 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
76 #ifdef CONFIG_ZONE_DMA32
84 EXPORT_SYMBOL(totalram_pages
);
86 static char *zone_names
[MAX_NR_ZONES
] = {
88 #ifdef CONFIG_ZONE_DMA32
97 int min_free_kbytes
= 1024;
99 unsigned long __meminitdata nr_kernel_pages
;
100 unsigned long __meminitdata nr_all_pages
;
101 static unsigned long __initdata dma_reserve
;
103 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
105 * MAX_ACTIVE_REGIONS determines the maxmimum number of distinct
106 * ranges of memory (RAM) that may be registered with add_active_range().
107 * Ranges passed to add_active_range() will be merged if possible
108 * so the number of times add_active_range() can be called is
109 * related to the number of nodes and the number of holes
111 #ifdef CONFIG_MAX_ACTIVE_REGIONS
112 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */
113 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
115 #if MAX_NUMNODES >= 32
116 /* If there can be many nodes, allow up to 50 holes per node */
117 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
119 /* By default, allow up to 256 distinct regions */
120 #define MAX_ACTIVE_REGIONS 256
124 struct node_active_region __initdata early_node_map
[MAX_ACTIVE_REGIONS
];
125 int __initdata nr_nodemap_entries
;
126 unsigned long __initdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
127 unsigned long __initdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
128 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
129 unsigned long __initdata node_boundary_start_pfn
[MAX_NUMNODES
];
130 unsigned long __initdata node_boundary_end_pfn
[MAX_NUMNODES
];
131 #endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
132 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
134 #ifdef CONFIG_DEBUG_VM
135 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
139 unsigned long pfn
= page_to_pfn(page
);
142 seq
= zone_span_seqbegin(zone
);
143 if (pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
145 else if (pfn
< zone
->zone_start_pfn
)
147 } while (zone_span_seqretry(zone
, seq
));
152 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
154 #ifdef CONFIG_HOLES_IN_ZONE
155 if (!pfn_valid(page_to_pfn(page
)))
158 if (zone
!= page_zone(page
))
164 * Temporary debugging check for pages not lying within a given zone.
166 static int bad_range(struct zone
*zone
, struct page
*page
)
168 if (page_outside_zone_boundaries(zone
, page
))
170 if (!page_is_consistent(zone
, page
))
176 static inline int bad_range(struct zone
*zone
, struct page
*page
)
182 static void bad_page(struct page
*page
)
184 printk(KERN_EMERG
"Bad page state in process '%s'\n"
185 KERN_EMERG
"page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n"
186 KERN_EMERG
"Trying to fix it up, but a reboot is needed\n"
187 KERN_EMERG
"Backtrace:\n",
188 current
->comm
, page
, (int)(2*sizeof(unsigned long)),
189 (unsigned long)page
->flags
, page
->mapping
,
190 page_mapcount(page
), page_count(page
));
192 page
->flags
&= ~(1 << PG_lru
|
202 set_page_count(page
, 0);
203 reset_page_mapcount(page
);
204 page
->mapping
= NULL
;
205 add_taint(TAINT_BAD_PAGE
);
209 * Higher-order pages are called "compound pages". They are structured thusly:
211 * The first PAGE_SIZE page is called the "head page".
213 * The remaining PAGE_SIZE pages are called "tail pages".
215 * All pages have PG_compound set. All pages have their ->private pointing at
216 * the head page (even the head page has this).
218 * The first tail page's ->lru.next holds the address of the compound page's
219 * put_page() function. Its ->lru.prev holds the order of allocation.
220 * This usage means that zero-order pages may not be compound.
223 static void free_compound_page(struct page
*page
)
225 __free_pages_ok(page
, (unsigned long)page
[1].lru
.prev
);
228 static void prep_compound_page(struct page
*page
, unsigned long order
)
231 int nr_pages
= 1 << order
;
233 page
[1].lru
.next
= (void *)free_compound_page
; /* set dtor */
234 page
[1].lru
.prev
= (void *)order
;
235 for (i
= 0; i
< nr_pages
; i
++) {
236 struct page
*p
= page
+ i
;
238 __SetPageCompound(p
);
239 set_page_private(p
, (unsigned long)page
);
243 static void destroy_compound_page(struct page
*page
, unsigned long order
)
246 int nr_pages
= 1 << order
;
248 if (unlikely((unsigned long)page
[1].lru
.prev
!= order
))
251 for (i
= 0; i
< nr_pages
; i
++) {
252 struct page
*p
= page
+ i
;
254 if (unlikely(!PageCompound(p
) |
255 (page_private(p
) != (unsigned long)page
)))
257 __ClearPageCompound(p
);
261 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
265 VM_BUG_ON((gfp_flags
& (__GFP_WAIT
| __GFP_HIGHMEM
)) == __GFP_HIGHMEM
);
267 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
268 * and __GFP_HIGHMEM from hard or soft interrupt context.
270 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
271 for (i
= 0; i
< (1 << order
); i
++)
272 clear_highpage(page
+ i
);
276 * function for dealing with page's order in buddy system.
277 * zone->lock is already acquired when we use these.
278 * So, we don't need atomic page->flags operations here.
280 static inline unsigned long page_order(struct page
*page
)
282 return page_private(page
);
285 static inline void set_page_order(struct page
*page
, int order
)
287 set_page_private(page
, order
);
288 __SetPageBuddy(page
);
291 static inline void rmv_page_order(struct page
*page
)
293 __ClearPageBuddy(page
);
294 set_page_private(page
, 0);
298 * Locate the struct page for both the matching buddy in our
299 * pair (buddy1) and the combined O(n+1) page they form (page).
301 * 1) Any buddy B1 will have an order O twin B2 which satisfies
302 * the following equation:
304 * For example, if the starting buddy (buddy2) is #8 its order
306 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
308 * 2) Any buddy B will have an order O+1 parent P which
309 * satisfies the following equation:
312 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
314 static inline struct page
*
315 __page_find_buddy(struct page
*page
, unsigned long page_idx
, unsigned int order
)
317 unsigned long buddy_idx
= page_idx
^ (1 << order
);
319 return page
+ (buddy_idx
- page_idx
);
322 static inline unsigned long
323 __find_combined_index(unsigned long page_idx
, unsigned int order
)
325 return (page_idx
& ~(1 << order
));
329 * This function checks whether a page is free && is the buddy
330 * we can do coalesce a page and its buddy if
331 * (a) the buddy is not in a hole &&
332 * (b) the buddy is in the buddy system &&
333 * (c) a page and its buddy have the same order &&
334 * (d) a page and its buddy are in the same zone.
336 * For recording whether a page is in the buddy system, we use PG_buddy.
337 * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
339 * For recording page's order, we use page_private(page).
341 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
344 #ifdef CONFIG_HOLES_IN_ZONE
345 if (!pfn_valid(page_to_pfn(buddy
)))
349 if (page_zone_id(page
) != page_zone_id(buddy
))
352 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
353 BUG_ON(page_count(buddy
) != 0);
360 * Freeing function for a buddy system allocator.
362 * The concept of a buddy system is to maintain direct-mapped table
363 * (containing bit values) for memory blocks of various "orders".
364 * The bottom level table contains the map for the smallest allocatable
365 * units of memory (here, pages), and each level above it describes
366 * pairs of units from the levels below, hence, "buddies".
367 * At a high level, all that happens here is marking the table entry
368 * at the bottom level available, and propagating the changes upward
369 * as necessary, plus some accounting needed to play nicely with other
370 * parts of the VM system.
371 * At each level, we keep a list of pages, which are heads of continuous
372 * free pages of length of (1 << order) and marked with PG_buddy. Page's
373 * order is recorded in page_private(page) field.
374 * So when we are allocating or freeing one, we can derive the state of the
375 * other. That is, if we allocate a small block, and both were
376 * free, the remainder of the region must be split into blocks.
377 * If a block is freed, and its buddy is also free, then this
378 * triggers coalescing into a block of larger size.
383 static inline void __free_one_page(struct page
*page
,
384 struct zone
*zone
, unsigned int order
)
386 unsigned long page_idx
;
387 int order_size
= 1 << order
;
389 if (unlikely(PageCompound(page
)))
390 destroy_compound_page(page
, order
);
392 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
394 VM_BUG_ON(page_idx
& (order_size
- 1));
395 VM_BUG_ON(bad_range(zone
, page
));
397 zone
->free_pages
+= order_size
;
398 while (order
< MAX_ORDER
-1) {
399 unsigned long combined_idx
;
400 struct free_area
*area
;
403 buddy
= __page_find_buddy(page
, page_idx
, order
);
404 if (!page_is_buddy(page
, buddy
, order
))
405 break; /* Move the buddy up one level. */
407 list_del(&buddy
->lru
);
408 area
= zone
->free_area
+ order
;
410 rmv_page_order(buddy
);
411 combined_idx
= __find_combined_index(page_idx
, order
);
412 page
= page
+ (combined_idx
- page_idx
);
413 page_idx
= combined_idx
;
416 set_page_order(page
, order
);
417 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
);
418 zone
->free_area
[order
].nr_free
++;
421 static inline int free_pages_check(struct page
*page
)
423 if (unlikely(page_mapcount(page
) |
424 (page
->mapping
!= NULL
) |
425 (page_count(page
) != 0) |
439 __ClearPageDirty(page
);
441 * For now, we report if PG_reserved was found set, but do not
442 * clear it, and do not free the page. But we shall soon need
443 * to do more, for when the ZERO_PAGE count wraps negative.
445 return PageReserved(page
);
449 * Frees a list of pages.
450 * Assumes all pages on list are in same zone, and of same order.
451 * count is the number of pages to free.
453 * If the zone was previously in an "all pages pinned" state then look to
454 * see if this freeing clears that state.
456 * And clear the zone's pages_scanned counter, to hold off the "all pages are
457 * pinned" detection logic.
459 static void free_pages_bulk(struct zone
*zone
, int count
,
460 struct list_head
*list
, int order
)
462 spin_lock(&zone
->lock
);
463 zone
->all_unreclaimable
= 0;
464 zone
->pages_scanned
= 0;
468 VM_BUG_ON(list_empty(list
));
469 page
= list_entry(list
->prev
, struct page
, lru
);
470 /* have to delete it as __free_one_page list manipulates */
471 list_del(&page
->lru
);
472 __free_one_page(page
, zone
, order
);
474 spin_unlock(&zone
->lock
);
477 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
)
479 spin_lock(&zone
->lock
);
480 zone
->all_unreclaimable
= 0;
481 zone
->pages_scanned
= 0;
482 __free_one_page(page
, zone
, order
);
483 spin_unlock(&zone
->lock
);
486 static void __free_pages_ok(struct page
*page
, unsigned int order
)
492 for (i
= 0 ; i
< (1 << order
) ; ++i
)
493 reserved
+= free_pages_check(page
+ i
);
497 if (!PageHighMem(page
))
498 debug_check_no_locks_freed(page_address(page
),PAGE_SIZE
<<order
);
499 arch_free_page(page
, order
);
500 kernel_map_pages(page
, 1 << order
, 0);
502 local_irq_save(flags
);
503 __count_vm_events(PGFREE
, 1 << order
);
504 free_one_page(page_zone(page
), page
, order
);
505 local_irq_restore(flags
);
509 * permit the bootmem allocator to evade page validation on high-order frees
511 void fastcall __init
__free_pages_bootmem(struct page
*page
, unsigned int order
)
514 __ClearPageReserved(page
);
515 set_page_count(page
, 0);
516 set_page_refcounted(page
);
522 for (loop
= 0; loop
< BITS_PER_LONG
; loop
++) {
523 struct page
*p
= &page
[loop
];
525 if (loop
+ 1 < BITS_PER_LONG
)
527 __ClearPageReserved(p
);
528 set_page_count(p
, 0);
531 set_page_refcounted(page
);
532 __free_pages(page
, order
);
538 * The order of subdivision here is critical for the IO subsystem.
539 * Please do not alter this order without good reasons and regression
540 * testing. Specifically, as large blocks of memory are subdivided,
541 * the order in which smaller blocks are delivered depends on the order
542 * they're subdivided in this function. This is the primary factor
543 * influencing the order in which pages are delivered to the IO
544 * subsystem according to empirical testing, and this is also justified
545 * by considering the behavior of a buddy system containing a single
546 * large block of memory acted on by a series of small allocations.
547 * This behavior is a critical factor in sglist merging's success.
551 static inline void expand(struct zone
*zone
, struct page
*page
,
552 int low
, int high
, struct free_area
*area
)
554 unsigned long size
= 1 << high
;
560 VM_BUG_ON(bad_range(zone
, &page
[size
]));
561 list_add(&page
[size
].lru
, &area
->free_list
);
563 set_page_order(&page
[size
], high
);
568 * This page is about to be returned from the page allocator
570 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
572 if (unlikely(page_mapcount(page
) |
573 (page
->mapping
!= NULL
) |
574 (page_count(page
) != 0) |
590 * For now, we report if PG_reserved was found set, but do not
591 * clear it, and do not allocate the page: as a safety net.
593 if (PageReserved(page
))
596 page
->flags
&= ~(1 << PG_uptodate
| 1 << PG_error
|
597 1 << PG_referenced
| 1 << PG_arch_1
|
598 1 << PG_checked
| 1 << PG_mappedtodisk
);
599 set_page_private(page
, 0);
600 set_page_refcounted(page
);
601 kernel_map_pages(page
, 1 << order
, 1);
603 if (gfp_flags
& __GFP_ZERO
)
604 prep_zero_page(page
, order
, gfp_flags
);
606 if (order
&& (gfp_flags
& __GFP_COMP
))
607 prep_compound_page(page
, order
);
613 * Do the hard work of removing an element from the buddy allocator.
614 * Call me with the zone->lock already held.
616 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
)
618 struct free_area
* area
;
619 unsigned int current_order
;
622 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
623 area
= zone
->free_area
+ current_order
;
624 if (list_empty(&area
->free_list
))
627 page
= list_entry(area
->free_list
.next
, struct page
, lru
);
628 list_del(&page
->lru
);
629 rmv_page_order(page
);
631 zone
->free_pages
-= 1UL << order
;
632 expand(zone
, page
, order
, current_order
, area
);
640 * Obtain a specified number of elements from the buddy allocator, all under
641 * a single hold of the lock, for efficiency. Add them to the supplied list.
642 * Returns the number of new pages which were placed at *list.
644 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
645 unsigned long count
, struct list_head
*list
)
649 spin_lock(&zone
->lock
);
650 for (i
= 0; i
< count
; ++i
) {
651 struct page
*page
= __rmqueue(zone
, order
);
652 if (unlikely(page
== NULL
))
654 list_add_tail(&page
->lru
, list
);
656 spin_unlock(&zone
->lock
);
662 * Called from the slab reaper to drain pagesets on a particular node that
663 * belongs to the currently executing processor.
664 * Note that this function must be called with the thread pinned to
665 * a single processor.
667 void drain_node_pages(int nodeid
)
673 for (z
= 0; z
< MAX_NR_ZONES
; z
++) {
674 struct zone
*zone
= NODE_DATA(nodeid
)->node_zones
+ z
;
675 struct per_cpu_pageset
*pset
;
677 if (!populated_zone(zone
))
680 pset
= zone_pcp(zone
, smp_processor_id());
681 for (i
= 0; i
< ARRAY_SIZE(pset
->pcp
); i
++) {
682 struct per_cpu_pages
*pcp
;
686 local_irq_save(flags
);
687 free_pages_bulk(zone
, pcp
->count
, &pcp
->list
, 0);
689 local_irq_restore(flags
);
696 #if defined(CONFIG_PM) || defined(CONFIG_HOTPLUG_CPU)
697 static void __drain_pages(unsigned int cpu
)
703 for_each_zone(zone
) {
704 struct per_cpu_pageset
*pset
;
706 pset
= zone_pcp(zone
, cpu
);
707 for (i
= 0; i
< ARRAY_SIZE(pset
->pcp
); i
++) {
708 struct per_cpu_pages
*pcp
;
711 local_irq_save(flags
);
712 free_pages_bulk(zone
, pcp
->count
, &pcp
->list
, 0);
714 local_irq_restore(flags
);
718 #endif /* CONFIG_PM || CONFIG_HOTPLUG_CPU */
722 void mark_free_pages(struct zone
*zone
)
724 unsigned long pfn
, max_zone_pfn
;
727 struct list_head
*curr
;
729 if (!zone
->spanned_pages
)
732 spin_lock_irqsave(&zone
->lock
, flags
);
734 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
735 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
736 if (pfn_valid(pfn
)) {
737 struct page
*page
= pfn_to_page(pfn
);
739 if (!PageNosave(page
))
740 ClearPageNosaveFree(page
);
743 for (order
= MAX_ORDER
- 1; order
>= 0; --order
)
744 list_for_each(curr
, &zone
->free_area
[order
].free_list
) {
747 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
748 for (i
= 0; i
< (1UL << order
); i
++)
749 SetPageNosaveFree(pfn_to_page(pfn
+ i
));
752 spin_unlock_irqrestore(&zone
->lock
, flags
);
756 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
758 void drain_local_pages(void)
762 local_irq_save(flags
);
763 __drain_pages(smp_processor_id());
764 local_irq_restore(flags
);
766 #endif /* CONFIG_PM */
769 * Free a 0-order page
771 static void fastcall
free_hot_cold_page(struct page
*page
, int cold
)
773 struct zone
*zone
= page_zone(page
);
774 struct per_cpu_pages
*pcp
;
778 page
->mapping
= NULL
;
779 if (free_pages_check(page
))
782 if (!PageHighMem(page
))
783 debug_check_no_locks_freed(page_address(page
), PAGE_SIZE
);
784 arch_free_page(page
, 0);
785 kernel_map_pages(page
, 1, 0);
787 pcp
= &zone_pcp(zone
, get_cpu())->pcp
[cold
];
788 local_irq_save(flags
);
789 __count_vm_event(PGFREE
);
790 list_add(&page
->lru
, &pcp
->list
);
792 if (pcp
->count
>= pcp
->high
) {
793 free_pages_bulk(zone
, pcp
->batch
, &pcp
->list
, 0);
794 pcp
->count
-= pcp
->batch
;
796 local_irq_restore(flags
);
800 void fastcall
free_hot_page(struct page
*page
)
802 free_hot_cold_page(page
, 0);
805 void fastcall
free_cold_page(struct page
*page
)
807 free_hot_cold_page(page
, 1);
811 * split_page takes a non-compound higher-order page, and splits it into
812 * n (1<<order) sub-pages: page[0..n]
813 * Each sub-page must be freed individually.
815 * Note: this is probably too low level an operation for use in drivers.
816 * Please consult with lkml before using this in your driver.
818 void split_page(struct page
*page
, unsigned int order
)
822 VM_BUG_ON(PageCompound(page
));
823 VM_BUG_ON(!page_count(page
));
824 for (i
= 1; i
< (1 << order
); i
++)
825 set_page_refcounted(page
+ i
);
829 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
830 * we cheat by calling it from here, in the order > 0 path. Saves a branch
833 static struct page
*buffered_rmqueue(struct zonelist
*zonelist
,
834 struct zone
*zone
, int order
, gfp_t gfp_flags
)
838 int cold
= !!(gfp_flags
& __GFP_COLD
);
843 if (likely(order
== 0)) {
844 struct per_cpu_pages
*pcp
;
846 pcp
= &zone_pcp(zone
, cpu
)->pcp
[cold
];
847 local_irq_save(flags
);
849 pcp
->count
= rmqueue_bulk(zone
, 0,
850 pcp
->batch
, &pcp
->list
);
851 if (unlikely(!pcp
->count
))
854 page
= list_entry(pcp
->list
.next
, struct page
, lru
);
855 list_del(&page
->lru
);
858 spin_lock_irqsave(&zone
->lock
, flags
);
859 page
= __rmqueue(zone
, order
);
860 spin_unlock(&zone
->lock
);
865 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
866 zone_statistics(zonelist
, zone
);
867 local_irq_restore(flags
);
870 VM_BUG_ON(bad_range(zone
, page
));
871 if (prep_new_page(page
, order
, gfp_flags
))
876 local_irq_restore(flags
);
881 #define ALLOC_NO_WATERMARKS 0x01 /* don't check watermarks at all */
882 #define ALLOC_WMARK_MIN 0x02 /* use pages_min watermark */
883 #define ALLOC_WMARK_LOW 0x04 /* use pages_low watermark */
884 #define ALLOC_WMARK_HIGH 0x08 /* use pages_high watermark */
885 #define ALLOC_HARDER 0x10 /* try to alloc harder */
886 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
887 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
890 * Return 1 if free pages are above 'mark'. This takes into account the order
893 int zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
894 int classzone_idx
, int alloc_flags
)
896 /* free_pages my go negative - that's OK */
897 unsigned long min
= mark
;
898 long free_pages
= z
->free_pages
- (1 << order
) + 1;
901 if (alloc_flags
& ALLOC_HIGH
)
903 if (alloc_flags
& ALLOC_HARDER
)
906 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
908 for (o
= 0; o
< order
; o
++) {
909 /* At the next order, this order's pages become unavailable */
910 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
912 /* Require fewer higher order pages to be free */
915 if (free_pages
<= min
)
923 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
924 * skip over zones that are not allowed by the cpuset, or that have
925 * been recently (in last second) found to be nearly full. See further
926 * comments in mmzone.h. Reduces cache footprint of zonelist scans
927 * that have to skip over alot of full or unallowed zones.
929 * If the zonelist cache is present in the passed in zonelist, then
930 * returns a pointer to the allowed node mask (either the current
931 * tasks mems_allowed, or node_online_map.)
933 * If the zonelist cache is not available for this zonelist, does
934 * nothing and returns NULL.
936 * If the fullzones BITMAP in the zonelist cache is stale (more than
937 * a second since last zap'd) then we zap it out (clear its bits.)
939 * We hold off even calling zlc_setup, until after we've checked the
940 * first zone in the zonelist, on the theory that most allocations will
941 * be satisfied from that first zone, so best to examine that zone as
944 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
946 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
947 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
949 zlc
= zonelist
->zlcache_ptr
;
953 if (jiffies
- zlc
->last_full_zap
> 1 * HZ
) {
954 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
955 zlc
->last_full_zap
= jiffies
;
958 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
959 &cpuset_current_mems_allowed
:
965 * Given 'z' scanning a zonelist, run a couple of quick checks to see
966 * if it is worth looking at further for free memory:
967 * 1) Check that the zone isn't thought to be full (doesn't have its
968 * bit set in the zonelist_cache fullzones BITMAP).
969 * 2) Check that the zones node (obtained from the zonelist_cache
970 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
971 * Return true (non-zero) if zone is worth looking at further, or
972 * else return false (zero) if it is not.
974 * This check -ignores- the distinction between various watermarks,
975 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
976 * found to be full for any variation of these watermarks, it will
977 * be considered full for up to one second by all requests, unless
978 * we are so low on memory on all allowed nodes that we are forced
979 * into the second scan of the zonelist.
981 * In the second scan we ignore this zonelist cache and exactly
982 * apply the watermarks to all zones, even it is slower to do so.
983 * We are low on memory in the second scan, and should leave no stone
984 * unturned looking for a free page.
986 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zone
**z
,
987 nodemask_t
*allowednodes
)
989 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
990 int i
; /* index of *z in zonelist zones */
991 int n
; /* node that zone *z is on */
993 zlc
= zonelist
->zlcache_ptr
;
997 i
= z
- zonelist
->zones
;
1000 /* This zone is worth trying if it is allowed but not full */
1001 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1005 * Given 'z' scanning a zonelist, set the corresponding bit in
1006 * zlc->fullzones, so that subsequent attempts to allocate a page
1007 * from that zone don't waste time re-examining it.
1009 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zone
**z
)
1011 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1012 int i
; /* index of *z in zonelist zones */
1014 zlc
= zonelist
->zlcache_ptr
;
1018 i
= z
- zonelist
->zones
;
1020 set_bit(i
, zlc
->fullzones
);
1023 #else /* CONFIG_NUMA */
1025 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1030 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zone
**z
,
1031 nodemask_t
*allowednodes
)
1036 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zone
**z
)
1039 #endif /* CONFIG_NUMA */
1042 * get_page_from_freelist goes through the zonelist trying to allocate
1045 static struct page
*
1046 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
,
1047 struct zonelist
*zonelist
, int alloc_flags
)
1050 struct page
*page
= NULL
;
1051 int classzone_idx
= zone_idx(zonelist
->zones
[0]);
1053 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1054 int zlc_active
= 0; /* set if using zonelist_cache */
1055 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1059 * Scan zonelist, looking for a zone with enough free.
1060 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1062 z
= zonelist
->zones
;
1065 if (NUMA_BUILD
&& zlc_active
&&
1066 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1069 if (unlikely(NUMA_BUILD
&& (gfp_mask
& __GFP_THISNODE
) &&
1070 zone
->zone_pgdat
!= zonelist
->zones
[0]->zone_pgdat
))
1072 if ((alloc_flags
& ALLOC_CPUSET
) &&
1073 !cpuset_zone_allowed(zone
, gfp_mask
))
1076 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
1078 if (alloc_flags
& ALLOC_WMARK_MIN
)
1079 mark
= zone
->pages_min
;
1080 else if (alloc_flags
& ALLOC_WMARK_LOW
)
1081 mark
= zone
->pages_low
;
1083 mark
= zone
->pages_high
;
1084 if (!zone_watermark_ok(zone
, order
, mark
,
1085 classzone_idx
, alloc_flags
)) {
1086 if (!zone_reclaim_mode
||
1087 !zone_reclaim(zone
, gfp_mask
, order
))
1088 goto this_zone_full
;
1092 page
= buffered_rmqueue(zonelist
, zone
, order
, gfp_mask
);
1097 zlc_mark_zone_full(zonelist
, z
);
1099 if (NUMA_BUILD
&& !did_zlc_setup
) {
1100 /* we do zlc_setup after the first zone is tried */
1101 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1105 } while (*(++z
) != NULL
);
1107 if (unlikely(NUMA_BUILD
&& page
== NULL
&& zlc_active
)) {
1108 /* Disable zlc cache for second zonelist scan */
1116 * This is the 'heart' of the zoned buddy allocator.
1118 struct page
* fastcall
1119 __alloc_pages(gfp_t gfp_mask
, unsigned int order
,
1120 struct zonelist
*zonelist
)
1122 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
1125 struct reclaim_state reclaim_state
;
1126 struct task_struct
*p
= current
;
1129 int did_some_progress
;
1131 might_sleep_if(wait
);
1134 z
= zonelist
->zones
; /* the list of zones suitable for gfp_mask */
1136 if (unlikely(*z
== NULL
)) {
1137 /* Should this ever happen?? */
1141 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, order
,
1142 zonelist
, ALLOC_WMARK_LOW
|ALLOC_CPUSET
);
1146 for (z
= zonelist
->zones
; *z
; z
++)
1147 wakeup_kswapd(*z
, order
);
1150 * OK, we're below the kswapd watermark and have kicked background
1151 * reclaim. Now things get more complex, so set up alloc_flags according
1152 * to how we want to proceed.
1154 * The caller may dip into page reserves a bit more if the caller
1155 * cannot run direct reclaim, or if the caller has realtime scheduling
1156 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
1157 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1159 alloc_flags
= ALLOC_WMARK_MIN
;
1160 if ((unlikely(rt_task(p
)) && !in_interrupt()) || !wait
)
1161 alloc_flags
|= ALLOC_HARDER
;
1162 if (gfp_mask
& __GFP_HIGH
)
1163 alloc_flags
|= ALLOC_HIGH
;
1165 alloc_flags
|= ALLOC_CPUSET
;
1168 * Go through the zonelist again. Let __GFP_HIGH and allocations
1169 * coming from realtime tasks go deeper into reserves.
1171 * This is the last chance, in general, before the goto nopage.
1172 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1173 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1175 page
= get_page_from_freelist(gfp_mask
, order
, zonelist
, alloc_flags
);
1179 /* This allocation should allow future memory freeing. */
1181 if (((p
->flags
& PF_MEMALLOC
) || unlikely(test_thread_flag(TIF_MEMDIE
)))
1182 && !in_interrupt()) {
1183 if (!(gfp_mask
& __GFP_NOMEMALLOC
)) {
1185 /* go through the zonelist yet again, ignoring mins */
1186 page
= get_page_from_freelist(gfp_mask
, order
,
1187 zonelist
, ALLOC_NO_WATERMARKS
);
1190 if (gfp_mask
& __GFP_NOFAIL
) {
1191 congestion_wait(WRITE
, HZ
/50);
1198 /* Atomic allocations - we can't balance anything */
1205 /* We now go into synchronous reclaim */
1206 cpuset_memory_pressure_bump();
1207 p
->flags
|= PF_MEMALLOC
;
1208 reclaim_state
.reclaimed_slab
= 0;
1209 p
->reclaim_state
= &reclaim_state
;
1211 did_some_progress
= try_to_free_pages(zonelist
->zones
, gfp_mask
);
1213 p
->reclaim_state
= NULL
;
1214 p
->flags
&= ~PF_MEMALLOC
;
1218 if (likely(did_some_progress
)) {
1219 page
= get_page_from_freelist(gfp_mask
, order
,
1220 zonelist
, alloc_flags
);
1223 } else if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
1225 * Go through the zonelist yet one more time, keep
1226 * very high watermark here, this is only to catch
1227 * a parallel oom killing, we must fail if we're still
1228 * under heavy pressure.
1230 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, order
,
1231 zonelist
, ALLOC_WMARK_HIGH
|ALLOC_CPUSET
);
1235 out_of_memory(zonelist
, gfp_mask
, order
);
1240 * Don't let big-order allocations loop unless the caller explicitly
1241 * requests that. Wait for some write requests to complete then retry.
1243 * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order
1244 * <= 3, but that may not be true in other implementations.
1247 if (!(gfp_mask
& __GFP_NORETRY
)) {
1248 if ((order
<= 3) || (gfp_mask
& __GFP_REPEAT
))
1250 if (gfp_mask
& __GFP_NOFAIL
)
1254 congestion_wait(WRITE
, HZ
/50);
1259 if (!(gfp_mask
& __GFP_NOWARN
) && printk_ratelimit()) {
1260 printk(KERN_WARNING
"%s: page allocation failure."
1261 " order:%d, mode:0x%x\n",
1262 p
->comm
, order
, gfp_mask
);
1270 EXPORT_SYMBOL(__alloc_pages
);
1273 * Common helper functions.
1275 fastcall
unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
1278 page
= alloc_pages(gfp_mask
, order
);
1281 return (unsigned long) page_address(page
);
1284 EXPORT_SYMBOL(__get_free_pages
);
1286 fastcall
unsigned long get_zeroed_page(gfp_t gfp_mask
)
1291 * get_zeroed_page() returns a 32-bit address, which cannot represent
1294 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
1296 page
= alloc_pages(gfp_mask
| __GFP_ZERO
, 0);
1298 return (unsigned long) page_address(page
);
1302 EXPORT_SYMBOL(get_zeroed_page
);
1304 void __pagevec_free(struct pagevec
*pvec
)
1306 int i
= pagevec_count(pvec
);
1309 free_hot_cold_page(pvec
->pages
[i
], pvec
->cold
);
1312 fastcall
void __free_pages(struct page
*page
, unsigned int order
)
1314 if (put_page_testzero(page
)) {
1316 free_hot_page(page
);
1318 __free_pages_ok(page
, order
);
1322 EXPORT_SYMBOL(__free_pages
);
1324 fastcall
void free_pages(unsigned long addr
, unsigned int order
)
1327 VM_BUG_ON(!virt_addr_valid((void *)addr
));
1328 __free_pages(virt_to_page((void *)addr
), order
);
1332 EXPORT_SYMBOL(free_pages
);
1335 * Total amount of free (allocatable) RAM:
1337 unsigned int nr_free_pages(void)
1339 unsigned int sum
= 0;
1343 sum
+= zone
->free_pages
;
1348 EXPORT_SYMBOL(nr_free_pages
);
1351 unsigned int nr_free_pages_pgdat(pg_data_t
*pgdat
)
1353 unsigned int sum
= 0;
1356 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
1357 sum
+= pgdat
->node_zones
[i
].free_pages
;
1363 static unsigned int nr_free_zone_pages(int offset
)
1365 /* Just pick one node, since fallback list is circular */
1366 pg_data_t
*pgdat
= NODE_DATA(numa_node_id());
1367 unsigned int sum
= 0;
1369 struct zonelist
*zonelist
= pgdat
->node_zonelists
+ offset
;
1370 struct zone
**zonep
= zonelist
->zones
;
1373 for (zone
= *zonep
++; zone
; zone
= *zonep
++) {
1374 unsigned long size
= zone
->present_pages
;
1375 unsigned long high
= zone
->pages_high
;
1384 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
1386 unsigned int nr_free_buffer_pages(void)
1388 return nr_free_zone_pages(gfp_zone(GFP_USER
));
1392 * Amount of free RAM allocatable within all zones
1394 unsigned int nr_free_pagecache_pages(void)
1396 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER
));
1399 static inline void show_node(struct zone
*zone
)
1402 printk("Node %ld ", zone_to_nid(zone
));
1405 void si_meminfo(struct sysinfo
*val
)
1407 val
->totalram
= totalram_pages
;
1409 val
->freeram
= nr_free_pages();
1410 val
->bufferram
= nr_blockdev_pages();
1411 val
->totalhigh
= totalhigh_pages
;
1412 val
->freehigh
= nr_free_highpages();
1413 val
->mem_unit
= PAGE_SIZE
;
1416 EXPORT_SYMBOL(si_meminfo
);
1419 void si_meminfo_node(struct sysinfo
*val
, int nid
)
1421 pg_data_t
*pgdat
= NODE_DATA(nid
);
1423 val
->totalram
= pgdat
->node_present_pages
;
1424 val
->freeram
= nr_free_pages_pgdat(pgdat
);
1425 #ifdef CONFIG_HIGHMEM
1426 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
1427 val
->freehigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].free_pages
;
1432 val
->mem_unit
= PAGE_SIZE
;
1436 #define K(x) ((x) << (PAGE_SHIFT-10))
1439 * Show free area list (used inside shift_scroll-lock stuff)
1440 * We also calculate the percentage fragmentation. We do this by counting the
1441 * memory on each free list with the exception of the first item on the list.
1443 void show_free_areas(void)
1446 unsigned long active
;
1447 unsigned long inactive
;
1451 for_each_zone(zone
) {
1452 if (!populated_zone(zone
))
1456 printk("%s per-cpu:\n", zone
->name
);
1458 for_each_online_cpu(cpu
) {
1459 struct per_cpu_pageset
*pageset
;
1461 pageset
= zone_pcp(zone
, cpu
);
1463 printk("CPU %4d: Hot: hi:%5d, btch:%4d usd:%4d "
1464 "Cold: hi:%5d, btch:%4d usd:%4d\n",
1465 cpu
, pageset
->pcp
[0].high
,
1466 pageset
->pcp
[0].batch
, pageset
->pcp
[0].count
,
1467 pageset
->pcp
[1].high
, pageset
->pcp
[1].batch
,
1468 pageset
->pcp
[1].count
);
1472 get_zone_counts(&active
, &inactive
, &free
);
1474 printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu "
1475 "unstable:%lu free:%u slab:%lu mapped:%lu pagetables:%lu\n",
1478 global_page_state(NR_FILE_DIRTY
),
1479 global_page_state(NR_WRITEBACK
),
1480 global_page_state(NR_UNSTABLE_NFS
),
1482 global_page_state(NR_SLAB_RECLAIMABLE
) +
1483 global_page_state(NR_SLAB_UNRECLAIMABLE
),
1484 global_page_state(NR_FILE_MAPPED
),
1485 global_page_state(NR_PAGETABLE
));
1487 for_each_zone(zone
) {
1490 if (!populated_zone(zone
))
1502 " pages_scanned:%lu"
1503 " all_unreclaimable? %s"
1506 K(zone
->free_pages
),
1509 K(zone
->pages_high
),
1511 K(zone
->nr_inactive
),
1512 K(zone
->present_pages
),
1513 zone
->pages_scanned
,
1514 (zone
->all_unreclaimable
? "yes" : "no")
1516 printk("lowmem_reserve[]:");
1517 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
1518 printk(" %lu", zone
->lowmem_reserve
[i
]);
1522 for_each_zone(zone
) {
1523 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
1525 if (!populated_zone(zone
))
1529 printk("%s: ", zone
->name
);
1531 spin_lock_irqsave(&zone
->lock
, flags
);
1532 for (order
= 0; order
< MAX_ORDER
; order
++) {
1533 nr
[order
] = zone
->free_area
[order
].nr_free
;
1534 total
+= nr
[order
] << order
;
1536 spin_unlock_irqrestore(&zone
->lock
, flags
);
1537 for (order
= 0; order
< MAX_ORDER
; order
++)
1538 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
1539 printk("= %lukB\n", K(total
));
1542 show_swap_cache_info();
1546 * Builds allocation fallback zone lists.
1548 * Add all populated zones of a node to the zonelist.
1550 static int __meminit
build_zonelists_node(pg_data_t
*pgdat
,
1551 struct zonelist
*zonelist
, int nr_zones
, enum zone_type zone_type
)
1555 BUG_ON(zone_type
>= MAX_NR_ZONES
);
1560 zone
= pgdat
->node_zones
+ zone_type
;
1561 if (populated_zone(zone
)) {
1562 zonelist
->zones
[nr_zones
++] = zone
;
1563 check_highest_zone(zone_type
);
1566 } while (zone_type
);
1571 #define MAX_NODE_LOAD (num_online_nodes())
1572 static int __meminitdata node_load
[MAX_NUMNODES
];
1574 * find_next_best_node - find the next node that should appear in a given node's fallback list
1575 * @node: node whose fallback list we're appending
1576 * @used_node_mask: nodemask_t of already used nodes
1578 * We use a number of factors to determine which is the next node that should
1579 * appear on a given node's fallback list. The node should not have appeared
1580 * already in @node's fallback list, and it should be the next closest node
1581 * according to the distance array (which contains arbitrary distance values
1582 * from each node to each node in the system), and should also prefer nodes
1583 * with no CPUs, since presumably they'll have very little allocation pressure
1584 * on them otherwise.
1585 * It returns -1 if no node is found.
1587 static int __meminit
find_next_best_node(int node
, nodemask_t
*used_node_mask
)
1590 int min_val
= INT_MAX
;
1593 /* Use the local node if we haven't already */
1594 if (!node_isset(node
, *used_node_mask
)) {
1595 node_set(node
, *used_node_mask
);
1599 for_each_online_node(n
) {
1602 /* Don't want a node to appear more than once */
1603 if (node_isset(n
, *used_node_mask
))
1606 /* Use the distance array to find the distance */
1607 val
= node_distance(node
, n
);
1609 /* Penalize nodes under us ("prefer the next node") */
1612 /* Give preference to headless and unused nodes */
1613 tmp
= node_to_cpumask(n
);
1614 if (!cpus_empty(tmp
))
1615 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
1617 /* Slight preference for less loaded node */
1618 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
1619 val
+= node_load
[n
];
1621 if (val
< min_val
) {
1628 node_set(best_node
, *used_node_mask
);
1633 static void __meminit
build_zonelists(pg_data_t
*pgdat
)
1635 int j
, node
, local_node
;
1637 int prev_node
, load
;
1638 struct zonelist
*zonelist
;
1639 nodemask_t used_mask
;
1641 /* initialize zonelists */
1642 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
1643 zonelist
= pgdat
->node_zonelists
+ i
;
1644 zonelist
->zones
[0] = NULL
;
1647 /* NUMA-aware ordering of nodes */
1648 local_node
= pgdat
->node_id
;
1649 load
= num_online_nodes();
1650 prev_node
= local_node
;
1651 nodes_clear(used_mask
);
1652 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
1653 int distance
= node_distance(local_node
, node
);
1656 * If another node is sufficiently far away then it is better
1657 * to reclaim pages in a zone before going off node.
1659 if (distance
> RECLAIM_DISTANCE
)
1660 zone_reclaim_mode
= 1;
1663 * We don't want to pressure a particular node.
1664 * So adding penalty to the first node in same
1665 * distance group to make it round-robin.
1668 if (distance
!= node_distance(local_node
, prev_node
))
1669 node_load
[node
] += load
;
1672 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
1673 zonelist
= pgdat
->node_zonelists
+ i
;
1674 for (j
= 0; zonelist
->zones
[j
] != NULL
; j
++);
1676 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
, i
);
1677 zonelist
->zones
[j
] = NULL
;
1682 /* Construct the zonelist performance cache - see further mmzone.h */
1683 static void __meminit
build_zonelist_cache(pg_data_t
*pgdat
)
1687 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
1688 struct zonelist
*zonelist
;
1689 struct zonelist_cache
*zlc
;
1692 zonelist
= pgdat
->node_zonelists
+ i
;
1693 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
1694 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1695 for (z
= zonelist
->zones
; *z
; z
++)
1696 zlc
->z_to_n
[z
- zonelist
->zones
] = zone_to_nid(*z
);
1700 #else /* CONFIG_NUMA */
1702 static void __meminit
build_zonelists(pg_data_t
*pgdat
)
1704 int node
, local_node
;
1707 local_node
= pgdat
->node_id
;
1708 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
1709 struct zonelist
*zonelist
;
1711 zonelist
= pgdat
->node_zonelists
+ i
;
1713 j
= build_zonelists_node(pgdat
, zonelist
, 0, i
);
1715 * Now we build the zonelist so that it contains the zones
1716 * of all the other nodes.
1717 * We don't want to pressure a particular node, so when
1718 * building the zones for node N, we make sure that the
1719 * zones coming right after the local ones are those from
1720 * node N+1 (modulo N)
1722 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
1723 if (!node_online(node
))
1725 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
, i
);
1727 for (node
= 0; node
< local_node
; node
++) {
1728 if (!node_online(node
))
1730 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
, i
);
1733 zonelist
->zones
[j
] = NULL
;
1737 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
1738 static void __meminit
build_zonelist_cache(pg_data_t
*pgdat
)
1742 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
1743 pgdat
->node_zonelists
[i
].zlcache_ptr
= NULL
;
1746 #endif /* CONFIG_NUMA */
1748 /* return values int ....just for stop_machine_run() */
1749 static int __meminit
__build_all_zonelists(void *dummy
)
1753 for_each_online_node(nid
) {
1754 build_zonelists(NODE_DATA(nid
));
1755 build_zonelist_cache(NODE_DATA(nid
));
1760 void __meminit
build_all_zonelists(void)
1762 if (system_state
== SYSTEM_BOOTING
) {
1763 __build_all_zonelists(NULL
);
1764 cpuset_init_current_mems_allowed();
1766 /* we have to stop all cpus to guaranntee there is no user
1768 stop_machine_run(__build_all_zonelists
, NULL
, NR_CPUS
);
1769 /* cpuset refresh routine should be here */
1771 vm_total_pages
= nr_free_pagecache_pages();
1772 printk("Built %i zonelists. Total pages: %ld\n",
1773 num_online_nodes(), vm_total_pages
);
1777 * Helper functions to size the waitqueue hash table.
1778 * Essentially these want to choose hash table sizes sufficiently
1779 * large so that collisions trying to wait on pages are rare.
1780 * But in fact, the number of active page waitqueues on typical
1781 * systems is ridiculously low, less than 200. So this is even
1782 * conservative, even though it seems large.
1784 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
1785 * waitqueues, i.e. the size of the waitq table given the number of pages.
1787 #define PAGES_PER_WAITQUEUE 256
1789 #ifndef CONFIG_MEMORY_HOTPLUG
1790 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
1792 unsigned long size
= 1;
1794 pages
/= PAGES_PER_WAITQUEUE
;
1796 while (size
< pages
)
1800 * Once we have dozens or even hundreds of threads sleeping
1801 * on IO we've got bigger problems than wait queue collision.
1802 * Limit the size of the wait table to a reasonable size.
1804 size
= min(size
, 4096UL);
1806 return max(size
, 4UL);
1810 * A zone's size might be changed by hot-add, so it is not possible to determine
1811 * a suitable size for its wait_table. So we use the maximum size now.
1813 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
1815 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
1816 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
1817 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
1819 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
1820 * or more by the traditional way. (See above). It equals:
1822 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
1823 * ia64(16K page size) : = ( 8G + 4M)byte.
1824 * powerpc (64K page size) : = (32G +16M)byte.
1826 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
1833 * This is an integer logarithm so that shifts can be used later
1834 * to extract the more random high bits from the multiplicative
1835 * hash function before the remainder is taken.
1837 static inline unsigned long wait_table_bits(unsigned long size
)
1842 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
1845 * Initially all pages are reserved - free ones are freed
1846 * up by free_all_bootmem() once the early boot process is
1847 * done. Non-atomic initialization, single-pass.
1849 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
1850 unsigned long start_pfn
)
1853 unsigned long end_pfn
= start_pfn
+ size
;
1856 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
1857 if (!early_pfn_valid(pfn
))
1859 if (!early_pfn_in_nid(pfn
, nid
))
1861 page
= pfn_to_page(pfn
);
1862 set_page_links(page
, zone
, nid
, pfn
);
1863 init_page_count(page
);
1864 reset_page_mapcount(page
);
1865 SetPageReserved(page
);
1866 INIT_LIST_HEAD(&page
->lru
);
1867 #ifdef WANT_PAGE_VIRTUAL
1868 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1869 if (!is_highmem_idx(zone
))
1870 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
1875 void zone_init_free_lists(struct pglist_data
*pgdat
, struct zone
*zone
,
1879 for (order
= 0; order
< MAX_ORDER
; order
++) {
1880 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
);
1881 zone
->free_area
[order
].nr_free
= 0;
1885 #ifndef __HAVE_ARCH_MEMMAP_INIT
1886 #define memmap_init(size, nid, zone, start_pfn) \
1887 memmap_init_zone((size), (nid), (zone), (start_pfn))
1890 static int __cpuinit
zone_batchsize(struct zone
*zone
)
1895 * The per-cpu-pages pools are set to around 1000th of the
1896 * size of the zone. But no more than 1/2 of a meg.
1898 * OK, so we don't know how big the cache is. So guess.
1900 batch
= zone
->present_pages
/ 1024;
1901 if (batch
* PAGE_SIZE
> 512 * 1024)
1902 batch
= (512 * 1024) / PAGE_SIZE
;
1903 batch
/= 4; /* We effectively *= 4 below */
1908 * Clamp the batch to a 2^n - 1 value. Having a power
1909 * of 2 value was found to be more likely to have
1910 * suboptimal cache aliasing properties in some cases.
1912 * For example if 2 tasks are alternately allocating
1913 * batches of pages, one task can end up with a lot
1914 * of pages of one half of the possible page colors
1915 * and the other with pages of the other colors.
1917 batch
= (1 << (fls(batch
+ batch
/2)-1)) - 1;
1922 inline void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
1924 struct per_cpu_pages
*pcp
;
1926 memset(p
, 0, sizeof(*p
));
1928 pcp
= &p
->pcp
[0]; /* hot */
1930 pcp
->high
= 6 * batch
;
1931 pcp
->batch
= max(1UL, 1 * batch
);
1932 INIT_LIST_HEAD(&pcp
->list
);
1934 pcp
= &p
->pcp
[1]; /* cold*/
1936 pcp
->high
= 2 * batch
;
1937 pcp
->batch
= max(1UL, batch
/2);
1938 INIT_LIST_HEAD(&pcp
->list
);
1942 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
1943 * to the value high for the pageset p.
1946 static void setup_pagelist_highmark(struct per_cpu_pageset
*p
,
1949 struct per_cpu_pages
*pcp
;
1951 pcp
= &p
->pcp
[0]; /* hot list */
1953 pcp
->batch
= max(1UL, high
/4);
1954 if ((high
/4) > (PAGE_SHIFT
* 8))
1955 pcp
->batch
= PAGE_SHIFT
* 8;
1961 * Boot pageset table. One per cpu which is going to be used for all
1962 * zones and all nodes. The parameters will be set in such a way
1963 * that an item put on a list will immediately be handed over to
1964 * the buddy list. This is safe since pageset manipulation is done
1965 * with interrupts disabled.
1967 * Some NUMA counter updates may also be caught by the boot pagesets.
1969 * The boot_pagesets must be kept even after bootup is complete for
1970 * unused processors and/or zones. They do play a role for bootstrapping
1971 * hotplugged processors.
1973 * zoneinfo_show() and maybe other functions do
1974 * not check if the processor is online before following the pageset pointer.
1975 * Other parts of the kernel may not check if the zone is available.
1977 static struct per_cpu_pageset boot_pageset
[NR_CPUS
];
1980 * Dynamically allocate memory for the
1981 * per cpu pageset array in struct zone.
1983 static int __cpuinit
process_zones(int cpu
)
1985 struct zone
*zone
, *dzone
;
1987 for_each_zone(zone
) {
1989 if (!populated_zone(zone
))
1992 zone_pcp(zone
, cpu
) = kmalloc_node(sizeof(struct per_cpu_pageset
),
1993 GFP_KERNEL
, cpu_to_node(cpu
));
1994 if (!zone_pcp(zone
, cpu
))
1997 setup_pageset(zone_pcp(zone
, cpu
), zone_batchsize(zone
));
1999 if (percpu_pagelist_fraction
)
2000 setup_pagelist_highmark(zone_pcp(zone
, cpu
),
2001 (zone
->present_pages
/ percpu_pagelist_fraction
));
2006 for_each_zone(dzone
) {
2009 kfree(zone_pcp(dzone
, cpu
));
2010 zone_pcp(dzone
, cpu
) = NULL
;
2015 static inline void free_zone_pagesets(int cpu
)
2019 for_each_zone(zone
) {
2020 struct per_cpu_pageset
*pset
= zone_pcp(zone
, cpu
);
2022 /* Free per_cpu_pageset if it is slab allocated */
2023 if (pset
!= &boot_pageset
[cpu
])
2025 zone_pcp(zone
, cpu
) = NULL
;
2029 static int __cpuinit
pageset_cpuup_callback(struct notifier_block
*nfb
,
2030 unsigned long action
,
2033 int cpu
= (long)hcpu
;
2034 int ret
= NOTIFY_OK
;
2037 case CPU_UP_PREPARE
:
2038 if (process_zones(cpu
))
2041 case CPU_UP_CANCELED
:
2043 free_zone_pagesets(cpu
);
2051 static struct notifier_block __cpuinitdata pageset_notifier
=
2052 { &pageset_cpuup_callback
, NULL
, 0 };
2054 void __init
setup_per_cpu_pageset(void)
2058 /* Initialize per_cpu_pageset for cpu 0.
2059 * A cpuup callback will do this for every cpu
2060 * as it comes online
2062 err
= process_zones(smp_processor_id());
2064 register_cpu_notifier(&pageset_notifier
);
2070 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
2073 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
2077 * The per-page waitqueue mechanism uses hashed waitqueues
2080 zone
->wait_table_hash_nr_entries
=
2081 wait_table_hash_nr_entries(zone_size_pages
);
2082 zone
->wait_table_bits
=
2083 wait_table_bits(zone
->wait_table_hash_nr_entries
);
2084 alloc_size
= zone
->wait_table_hash_nr_entries
2085 * sizeof(wait_queue_head_t
);
2087 if (system_state
== SYSTEM_BOOTING
) {
2088 zone
->wait_table
= (wait_queue_head_t
*)
2089 alloc_bootmem_node(pgdat
, alloc_size
);
2092 * This case means that a zone whose size was 0 gets new memory
2093 * via memory hot-add.
2094 * But it may be the case that a new node was hot-added. In
2095 * this case vmalloc() will not be able to use this new node's
2096 * memory - this wait_table must be initialized to use this new
2097 * node itself as well.
2098 * To use this new node's memory, further consideration will be
2101 zone
->wait_table
= (wait_queue_head_t
*)vmalloc(alloc_size
);
2103 if (!zone
->wait_table
)
2106 for(i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
2107 init_waitqueue_head(zone
->wait_table
+ i
);
2112 static __meminit
void zone_pcp_init(struct zone
*zone
)
2115 unsigned long batch
= zone_batchsize(zone
);
2117 for (cpu
= 0; cpu
< NR_CPUS
; cpu
++) {
2119 /* Early boot. Slab allocator not functional yet */
2120 zone_pcp(zone
, cpu
) = &boot_pageset
[cpu
];
2121 setup_pageset(&boot_pageset
[cpu
],0);
2123 setup_pageset(zone_pcp(zone
,cpu
), batch
);
2126 if (zone
->present_pages
)
2127 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%lu\n",
2128 zone
->name
, zone
->present_pages
, batch
);
2131 __meminit
int init_currently_empty_zone(struct zone
*zone
,
2132 unsigned long zone_start_pfn
,
2135 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
2137 ret
= zone_wait_table_init(zone
, size
);
2140 pgdat
->nr_zones
= zone_idx(zone
) + 1;
2142 zone
->zone_start_pfn
= zone_start_pfn
;
2144 memmap_init(size
, pgdat
->node_id
, zone_idx(zone
), zone_start_pfn
);
2146 zone_init_free_lists(pgdat
, zone
, zone
->spanned_pages
);
2151 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
2153 * Basic iterator support. Return the first range of PFNs for a node
2154 * Note: nid == MAX_NUMNODES returns first region regardless of node
2156 static int __init
first_active_region_index_in_nid(int nid
)
2160 for (i
= 0; i
< nr_nodemap_entries
; i
++)
2161 if (nid
== MAX_NUMNODES
|| early_node_map
[i
].nid
== nid
)
2168 * Basic iterator support. Return the next active range of PFNs for a node
2169 * Note: nid == MAX_NUMNODES returns next region regardles of node
2171 static int __init
next_active_region_index_in_nid(int index
, int nid
)
2173 for (index
= index
+ 1; index
< nr_nodemap_entries
; index
++)
2174 if (nid
== MAX_NUMNODES
|| early_node_map
[index
].nid
== nid
)
2180 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
2182 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
2183 * Architectures may implement their own version but if add_active_range()
2184 * was used and there are no special requirements, this is a convenient
2187 int __init
early_pfn_to_nid(unsigned long pfn
)
2191 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
2192 unsigned long start_pfn
= early_node_map
[i
].start_pfn
;
2193 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
2195 if (start_pfn
<= pfn
&& pfn
< end_pfn
)
2196 return early_node_map
[i
].nid
;
2201 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
2203 /* Basic iterator support to walk early_node_map[] */
2204 #define for_each_active_range_index_in_nid(i, nid) \
2205 for (i = first_active_region_index_in_nid(nid); i != -1; \
2206 i = next_active_region_index_in_nid(i, nid))
2209 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
2210 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
2211 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
2213 * If an architecture guarantees that all ranges registered with
2214 * add_active_ranges() contain no holes and may be freed, this
2215 * this function may be used instead of calling free_bootmem() manually.
2217 void __init
free_bootmem_with_active_regions(int nid
,
2218 unsigned long max_low_pfn
)
2222 for_each_active_range_index_in_nid(i
, nid
) {
2223 unsigned long size_pages
= 0;
2224 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
2226 if (early_node_map
[i
].start_pfn
>= max_low_pfn
)
2229 if (end_pfn
> max_low_pfn
)
2230 end_pfn
= max_low_pfn
;
2232 size_pages
= end_pfn
- early_node_map
[i
].start_pfn
;
2233 free_bootmem_node(NODE_DATA(early_node_map
[i
].nid
),
2234 PFN_PHYS(early_node_map
[i
].start_pfn
),
2235 size_pages
<< PAGE_SHIFT
);
2240 * sparse_memory_present_with_active_regions - Call memory_present for each active range
2241 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
2243 * If an architecture guarantees that all ranges registered with
2244 * add_active_ranges() contain no holes and may be freed, this
2245 * function may be used instead of calling memory_present() manually.
2247 void __init
sparse_memory_present_with_active_regions(int nid
)
2251 for_each_active_range_index_in_nid(i
, nid
)
2252 memory_present(early_node_map
[i
].nid
,
2253 early_node_map
[i
].start_pfn
,
2254 early_node_map
[i
].end_pfn
);
2258 * push_node_boundaries - Push node boundaries to at least the requested boundary
2259 * @nid: The nid of the node to push the boundary for
2260 * @start_pfn: The start pfn of the node
2261 * @end_pfn: The end pfn of the node
2263 * In reserve-based hot-add, mem_map is allocated that is unused until hotadd
2264 * time. Specifically, on x86_64, SRAT will report ranges that can potentially
2265 * be hotplugged even though no physical memory exists. This function allows
2266 * an arch to push out the node boundaries so mem_map is allocated that can
2269 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
2270 void __init
push_node_boundaries(unsigned int nid
,
2271 unsigned long start_pfn
, unsigned long end_pfn
)
2273 printk(KERN_DEBUG
"Entering push_node_boundaries(%u, %lu, %lu)\n",
2274 nid
, start_pfn
, end_pfn
);
2276 /* Initialise the boundary for this node if necessary */
2277 if (node_boundary_end_pfn
[nid
] == 0)
2278 node_boundary_start_pfn
[nid
] = -1UL;
2280 /* Update the boundaries */
2281 if (node_boundary_start_pfn
[nid
] > start_pfn
)
2282 node_boundary_start_pfn
[nid
] = start_pfn
;
2283 if (node_boundary_end_pfn
[nid
] < end_pfn
)
2284 node_boundary_end_pfn
[nid
] = end_pfn
;
2287 /* If necessary, push the node boundary out for reserve hotadd */
2288 static void __init
account_node_boundary(unsigned int nid
,
2289 unsigned long *start_pfn
, unsigned long *end_pfn
)
2291 printk(KERN_DEBUG
"Entering account_node_boundary(%u, %lu, %lu)\n",
2292 nid
, *start_pfn
, *end_pfn
);
2294 /* Return if boundary information has not been provided */
2295 if (node_boundary_end_pfn
[nid
] == 0)
2298 /* Check the boundaries and update if necessary */
2299 if (node_boundary_start_pfn
[nid
] < *start_pfn
)
2300 *start_pfn
= node_boundary_start_pfn
[nid
];
2301 if (node_boundary_end_pfn
[nid
] > *end_pfn
)
2302 *end_pfn
= node_boundary_end_pfn
[nid
];
2305 void __init
push_node_boundaries(unsigned int nid
,
2306 unsigned long start_pfn
, unsigned long end_pfn
) {}
2308 static void __init
account_node_boundary(unsigned int nid
,
2309 unsigned long *start_pfn
, unsigned long *end_pfn
) {}
2314 * get_pfn_range_for_nid - Return the start and end page frames for a node
2315 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
2316 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
2317 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
2319 * It returns the start and end page frame of a node based on information
2320 * provided by an arch calling add_active_range(). If called for a node
2321 * with no available memory, a warning is printed and the start and end
2324 void __init
get_pfn_range_for_nid(unsigned int nid
,
2325 unsigned long *start_pfn
, unsigned long *end_pfn
)
2331 for_each_active_range_index_in_nid(i
, nid
) {
2332 *start_pfn
= min(*start_pfn
, early_node_map
[i
].start_pfn
);
2333 *end_pfn
= max(*end_pfn
, early_node_map
[i
].end_pfn
);
2336 if (*start_pfn
== -1UL) {
2337 printk(KERN_WARNING
"Node %u active with no memory\n", nid
);
2341 /* Push the node boundaries out if requested */
2342 account_node_boundary(nid
, start_pfn
, end_pfn
);
2346 * Return the number of pages a zone spans in a node, including holes
2347 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
2349 unsigned long __init
zone_spanned_pages_in_node(int nid
,
2350 unsigned long zone_type
,
2351 unsigned long *ignored
)
2353 unsigned long node_start_pfn
, node_end_pfn
;
2354 unsigned long zone_start_pfn
, zone_end_pfn
;
2356 /* Get the start and end of the node and zone */
2357 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
2358 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
2359 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
2361 /* Check that this node has pages within the zone's required range */
2362 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
2365 /* Move the zone boundaries inside the node if necessary */
2366 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
2367 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
2369 /* Return the spanned pages */
2370 return zone_end_pfn
- zone_start_pfn
;
2374 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
2375 * then all holes in the requested range will be accounted for.
2377 unsigned long __init
__absent_pages_in_range(int nid
,
2378 unsigned long range_start_pfn
,
2379 unsigned long range_end_pfn
)
2382 unsigned long prev_end_pfn
= 0, hole_pages
= 0;
2383 unsigned long start_pfn
;
2385 /* Find the end_pfn of the first active range of pfns in the node */
2386 i
= first_active_region_index_in_nid(nid
);
2390 /* Account for ranges before physical memory on this node */
2391 if (early_node_map
[i
].start_pfn
> range_start_pfn
)
2392 hole_pages
= early_node_map
[i
].start_pfn
- range_start_pfn
;
2394 prev_end_pfn
= early_node_map
[i
].start_pfn
;
2396 /* Find all holes for the zone within the node */
2397 for (; i
!= -1; i
= next_active_region_index_in_nid(i
, nid
)) {
2399 /* No need to continue if prev_end_pfn is outside the zone */
2400 if (prev_end_pfn
>= range_end_pfn
)
2403 /* Make sure the end of the zone is not within the hole */
2404 start_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
2405 prev_end_pfn
= max(prev_end_pfn
, range_start_pfn
);
2407 /* Update the hole size cound and move on */
2408 if (start_pfn
> range_start_pfn
) {
2409 BUG_ON(prev_end_pfn
> start_pfn
);
2410 hole_pages
+= start_pfn
- prev_end_pfn
;
2412 prev_end_pfn
= early_node_map
[i
].end_pfn
;
2415 /* Account for ranges past physical memory on this node */
2416 if (range_end_pfn
> prev_end_pfn
)
2417 hole_pages
+= range_end_pfn
-
2418 max(range_start_pfn
, prev_end_pfn
);
2424 * absent_pages_in_range - Return number of page frames in holes within a range
2425 * @start_pfn: The start PFN to start searching for holes
2426 * @end_pfn: The end PFN to stop searching for holes
2428 * It returns the number of pages frames in memory holes within a range.
2430 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
2431 unsigned long end_pfn
)
2433 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
2436 /* Return the number of page frames in holes in a zone on a node */
2437 unsigned long __init
zone_absent_pages_in_node(int nid
,
2438 unsigned long zone_type
,
2439 unsigned long *ignored
)
2441 unsigned long node_start_pfn
, node_end_pfn
;
2442 unsigned long zone_start_pfn
, zone_end_pfn
;
2444 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
2445 zone_start_pfn
= max(arch_zone_lowest_possible_pfn
[zone_type
],
2447 zone_end_pfn
= min(arch_zone_highest_possible_pfn
[zone_type
],
2450 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
2454 static inline unsigned long zone_spanned_pages_in_node(int nid
,
2455 unsigned long zone_type
,
2456 unsigned long *zones_size
)
2458 return zones_size
[zone_type
];
2461 static inline unsigned long zone_absent_pages_in_node(int nid
,
2462 unsigned long zone_type
,
2463 unsigned long *zholes_size
)
2468 return zholes_size
[zone_type
];
2473 static void __init
calculate_node_totalpages(struct pglist_data
*pgdat
,
2474 unsigned long *zones_size
, unsigned long *zholes_size
)
2476 unsigned long realtotalpages
, totalpages
= 0;
2479 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
2480 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
2482 pgdat
->node_spanned_pages
= totalpages
;
2484 realtotalpages
= totalpages
;
2485 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
2487 zone_absent_pages_in_node(pgdat
->node_id
, i
,
2489 pgdat
->node_present_pages
= realtotalpages
;
2490 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
2495 * Set up the zone data structures:
2496 * - mark all pages reserved
2497 * - mark all memory queues empty
2498 * - clear the memory bitmaps
2500 static void __meminit
free_area_init_core(struct pglist_data
*pgdat
,
2501 unsigned long *zones_size
, unsigned long *zholes_size
)
2504 int nid
= pgdat
->node_id
;
2505 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
2508 pgdat_resize_init(pgdat
);
2509 pgdat
->nr_zones
= 0;
2510 init_waitqueue_head(&pgdat
->kswapd_wait
);
2511 pgdat
->kswapd_max_order
= 0;
2513 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
2514 struct zone
*zone
= pgdat
->node_zones
+ j
;
2515 unsigned long size
, realsize
, memmap_pages
;
2517 size
= zone_spanned_pages_in_node(nid
, j
, zones_size
);
2518 realsize
= size
- zone_absent_pages_in_node(nid
, j
,
2522 * Adjust realsize so that it accounts for how much memory
2523 * is used by this zone for memmap. This affects the watermark
2524 * and per-cpu initialisations
2526 memmap_pages
= (size
* sizeof(struct page
)) >> PAGE_SHIFT
;
2527 if (realsize
>= memmap_pages
) {
2528 realsize
-= memmap_pages
;
2530 " %s zone: %lu pages used for memmap\n",
2531 zone_names
[j
], memmap_pages
);
2534 " %s zone: %lu pages exceeds realsize %lu\n",
2535 zone_names
[j
], memmap_pages
, realsize
);
2537 /* Account for reserved DMA pages */
2538 if (j
== ZONE_DMA
&& realsize
> dma_reserve
) {
2539 realsize
-= dma_reserve
;
2540 printk(KERN_DEBUG
" DMA zone: %lu pages reserved\n",
2544 if (!is_highmem_idx(j
))
2545 nr_kernel_pages
+= realsize
;
2546 nr_all_pages
+= realsize
;
2548 zone
->spanned_pages
= size
;
2549 zone
->present_pages
= realsize
;
2552 zone
->min_unmapped_pages
= (realsize
*sysctl_min_unmapped_ratio
)
2554 zone
->min_slab_pages
= (realsize
* sysctl_min_slab_ratio
) / 100;
2556 zone
->name
= zone_names
[j
];
2557 spin_lock_init(&zone
->lock
);
2558 spin_lock_init(&zone
->lru_lock
);
2559 zone_seqlock_init(zone
);
2560 zone
->zone_pgdat
= pgdat
;
2561 zone
->free_pages
= 0;
2563 zone
->prev_priority
= DEF_PRIORITY
;
2565 zone_pcp_init(zone
);
2566 INIT_LIST_HEAD(&zone
->active_list
);
2567 INIT_LIST_HEAD(&zone
->inactive_list
);
2568 zone
->nr_scan_active
= 0;
2569 zone
->nr_scan_inactive
= 0;
2570 zone
->nr_active
= 0;
2571 zone
->nr_inactive
= 0;
2572 zap_zone_vm_stats(zone
);
2573 atomic_set(&zone
->reclaim_in_progress
, 0);
2577 ret
= init_currently_empty_zone(zone
, zone_start_pfn
, size
);
2579 zone_start_pfn
+= size
;
2583 static void __init
alloc_node_mem_map(struct pglist_data
*pgdat
)
2585 /* Skip empty nodes */
2586 if (!pgdat
->node_spanned_pages
)
2589 #ifdef CONFIG_FLAT_NODE_MEM_MAP
2590 /* ia64 gets its own node_mem_map, before this, without bootmem */
2591 if (!pgdat
->node_mem_map
) {
2592 unsigned long size
, start
, end
;
2596 * The zone's endpoints aren't required to be MAX_ORDER
2597 * aligned but the node_mem_map endpoints must be in order
2598 * for the buddy allocator to function correctly.
2600 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
2601 end
= pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
2602 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
2603 size
= (end
- start
) * sizeof(struct page
);
2604 map
= alloc_remap(pgdat
->node_id
, size
);
2606 map
= alloc_bootmem_node(pgdat
, size
);
2607 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
2609 #ifdef CONFIG_FLATMEM
2611 * With no DISCONTIG, the global mem_map is just set as node 0's
2613 if (pgdat
== NODE_DATA(0)) {
2614 mem_map
= NODE_DATA(0)->node_mem_map
;
2615 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
2616 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
2617 mem_map
-= pgdat
->node_start_pfn
;
2618 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
2621 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
2624 void __meminit
free_area_init_node(int nid
, struct pglist_data
*pgdat
,
2625 unsigned long *zones_size
, unsigned long node_start_pfn
,
2626 unsigned long *zholes_size
)
2628 pgdat
->node_id
= nid
;
2629 pgdat
->node_start_pfn
= node_start_pfn
;
2630 calculate_node_totalpages(pgdat
, zones_size
, zholes_size
);
2632 alloc_node_mem_map(pgdat
);
2634 free_area_init_core(pgdat
, zones_size
, zholes_size
);
2637 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
2639 * add_active_range - Register a range of PFNs backed by physical memory
2640 * @nid: The node ID the range resides on
2641 * @start_pfn: The start PFN of the available physical memory
2642 * @end_pfn: The end PFN of the available physical memory
2644 * These ranges are stored in an early_node_map[] and later used by
2645 * free_area_init_nodes() to calculate zone sizes and holes. If the
2646 * range spans a memory hole, it is up to the architecture to ensure
2647 * the memory is not freed by the bootmem allocator. If possible
2648 * the range being registered will be merged with existing ranges.
2650 void __init
add_active_range(unsigned int nid
, unsigned long start_pfn
,
2651 unsigned long end_pfn
)
2655 printk(KERN_DEBUG
"Entering add_active_range(%d, %lu, %lu) "
2656 "%d entries of %d used\n",
2657 nid
, start_pfn
, end_pfn
,
2658 nr_nodemap_entries
, MAX_ACTIVE_REGIONS
);
2660 /* Merge with existing active regions if possible */
2661 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
2662 if (early_node_map
[i
].nid
!= nid
)
2665 /* Skip if an existing region covers this new one */
2666 if (start_pfn
>= early_node_map
[i
].start_pfn
&&
2667 end_pfn
<= early_node_map
[i
].end_pfn
)
2670 /* Merge forward if suitable */
2671 if (start_pfn
<= early_node_map
[i
].end_pfn
&&
2672 end_pfn
> early_node_map
[i
].end_pfn
) {
2673 early_node_map
[i
].end_pfn
= end_pfn
;
2677 /* Merge backward if suitable */
2678 if (start_pfn
< early_node_map
[i
].end_pfn
&&
2679 end_pfn
>= early_node_map
[i
].start_pfn
) {
2680 early_node_map
[i
].start_pfn
= start_pfn
;
2685 /* Check that early_node_map is large enough */
2686 if (i
>= MAX_ACTIVE_REGIONS
) {
2687 printk(KERN_CRIT
"More than %d memory regions, truncating\n",
2688 MAX_ACTIVE_REGIONS
);
2692 early_node_map
[i
].nid
= nid
;
2693 early_node_map
[i
].start_pfn
= start_pfn
;
2694 early_node_map
[i
].end_pfn
= end_pfn
;
2695 nr_nodemap_entries
= i
+ 1;
2699 * shrink_active_range - Shrink an existing registered range of PFNs
2700 * @nid: The node id the range is on that should be shrunk
2701 * @old_end_pfn: The old end PFN of the range
2702 * @new_end_pfn: The new PFN of the range
2704 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
2705 * The map is kept at the end physical page range that has already been
2706 * registered with add_active_range(). This function allows an arch to shrink
2707 * an existing registered range.
2709 void __init
shrink_active_range(unsigned int nid
, unsigned long old_end_pfn
,
2710 unsigned long new_end_pfn
)
2714 /* Find the old active region end and shrink */
2715 for_each_active_range_index_in_nid(i
, nid
)
2716 if (early_node_map
[i
].end_pfn
== old_end_pfn
) {
2717 early_node_map
[i
].end_pfn
= new_end_pfn
;
2723 * remove_all_active_ranges - Remove all currently registered regions
2725 * During discovery, it may be found that a table like SRAT is invalid
2726 * and an alternative discovery method must be used. This function removes
2727 * all currently registered regions.
2729 void __init
remove_all_active_ranges(void)
2731 memset(early_node_map
, 0, sizeof(early_node_map
));
2732 nr_nodemap_entries
= 0;
2733 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
2734 memset(node_boundary_start_pfn
, 0, sizeof(node_boundary_start_pfn
));
2735 memset(node_boundary_end_pfn
, 0, sizeof(node_boundary_end_pfn
));
2736 #endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
2739 /* Compare two active node_active_regions */
2740 static int __init
cmp_node_active_region(const void *a
, const void *b
)
2742 struct node_active_region
*arange
= (struct node_active_region
*)a
;
2743 struct node_active_region
*brange
= (struct node_active_region
*)b
;
2745 /* Done this way to avoid overflows */
2746 if (arange
->start_pfn
> brange
->start_pfn
)
2748 if (arange
->start_pfn
< brange
->start_pfn
)
2754 /* sort the node_map by start_pfn */
2755 static void __init
sort_node_map(void)
2757 sort(early_node_map
, (size_t)nr_nodemap_entries
,
2758 sizeof(struct node_active_region
),
2759 cmp_node_active_region
, NULL
);
2762 /* Find the lowest pfn for a node. This depends on a sorted early_node_map */
2763 unsigned long __init
find_min_pfn_for_node(unsigned long nid
)
2767 /* Regions in the early_node_map can be in any order */
2770 /* Assuming a sorted map, the first range found has the starting pfn */
2771 for_each_active_range_index_in_nid(i
, nid
)
2772 return early_node_map
[i
].start_pfn
;
2774 printk(KERN_WARNING
"Could not find start_pfn for node %lu\n", nid
);
2779 * find_min_pfn_with_active_regions - Find the minimum PFN registered
2781 * It returns the minimum PFN based on information provided via
2782 * add_active_range().
2784 unsigned long __init
find_min_pfn_with_active_regions(void)
2786 return find_min_pfn_for_node(MAX_NUMNODES
);
2790 * find_max_pfn_with_active_regions - Find the maximum PFN registered
2792 * It returns the maximum PFN based on information provided via
2793 * add_active_range().
2795 unsigned long __init
find_max_pfn_with_active_regions(void)
2798 unsigned long max_pfn
= 0;
2800 for (i
= 0; i
< nr_nodemap_entries
; i
++)
2801 max_pfn
= max(max_pfn
, early_node_map
[i
].end_pfn
);
2807 * free_area_init_nodes - Initialise all pg_data_t and zone data
2808 * @max_zone_pfn: an array of max PFNs for each zone
2810 * This will call free_area_init_node() for each active node in the system.
2811 * Using the page ranges provided by add_active_range(), the size of each
2812 * zone in each node and their holes is calculated. If the maximum PFN
2813 * between two adjacent zones match, it is assumed that the zone is empty.
2814 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
2815 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
2816 * starts where the previous one ended. For example, ZONE_DMA32 starts
2817 * at arch_max_dma_pfn.
2819 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
2824 /* Record where the zone boundaries are */
2825 memset(arch_zone_lowest_possible_pfn
, 0,
2826 sizeof(arch_zone_lowest_possible_pfn
));
2827 memset(arch_zone_highest_possible_pfn
, 0,
2828 sizeof(arch_zone_highest_possible_pfn
));
2829 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
2830 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
2831 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
2832 arch_zone_lowest_possible_pfn
[i
] =
2833 arch_zone_highest_possible_pfn
[i
-1];
2834 arch_zone_highest_possible_pfn
[i
] =
2835 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
2838 /* Print out the zone ranges */
2839 printk("Zone PFN ranges:\n");
2840 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
2841 printk(" %-8s %8lu -> %8lu\n",
2843 arch_zone_lowest_possible_pfn
[i
],
2844 arch_zone_highest_possible_pfn
[i
]);
2846 /* Print out the early_node_map[] */
2847 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries
);
2848 for (i
= 0; i
< nr_nodemap_entries
; i
++)
2849 printk(" %3d: %8lu -> %8lu\n", early_node_map
[i
].nid
,
2850 early_node_map
[i
].start_pfn
,
2851 early_node_map
[i
].end_pfn
);
2853 /* Initialise every node */
2854 for_each_online_node(nid
) {
2855 pg_data_t
*pgdat
= NODE_DATA(nid
);
2856 free_area_init_node(nid
, pgdat
, NULL
,
2857 find_min_pfn_for_node(nid
), NULL
);
2860 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
2863 * set_dma_reserve - set the specified number of pages reserved in the first zone
2864 * @new_dma_reserve: The number of pages to mark reserved
2866 * The per-cpu batchsize and zone watermarks are determined by present_pages.
2867 * In the DMA zone, a significant percentage may be consumed by kernel image
2868 * and other unfreeable allocations which can skew the watermarks badly. This
2869 * function may optionally be used to account for unfreeable pages in the
2870 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
2871 * smaller per-cpu batchsize.
2873 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
2875 dma_reserve
= new_dma_reserve
;
2878 #ifndef CONFIG_NEED_MULTIPLE_NODES
2879 static bootmem_data_t contig_bootmem_data
;
2880 struct pglist_data contig_page_data
= { .bdata
= &contig_bootmem_data
};
2882 EXPORT_SYMBOL(contig_page_data
);
2885 void __init
free_area_init(unsigned long *zones_size
)
2887 free_area_init_node(0, NODE_DATA(0), zones_size
,
2888 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
2891 #ifdef CONFIG_HOTPLUG_CPU
2892 static int page_alloc_cpu_notify(struct notifier_block
*self
,
2893 unsigned long action
, void *hcpu
)
2895 int cpu
= (unsigned long)hcpu
;
2897 if (action
== CPU_DEAD
) {
2898 local_irq_disable();
2900 vm_events_fold_cpu(cpu
);
2902 refresh_cpu_vm_stats(cpu
);
2906 #endif /* CONFIG_HOTPLUG_CPU */
2908 void __init
page_alloc_init(void)
2910 hotcpu_notifier(page_alloc_cpu_notify
, 0);
2914 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
2915 * or min_free_kbytes changes.
2917 static void calculate_totalreserve_pages(void)
2919 struct pglist_data
*pgdat
;
2920 unsigned long reserve_pages
= 0;
2921 enum zone_type i
, j
;
2923 for_each_online_pgdat(pgdat
) {
2924 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
2925 struct zone
*zone
= pgdat
->node_zones
+ i
;
2926 unsigned long max
= 0;
2928 /* Find valid and maximum lowmem_reserve in the zone */
2929 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
2930 if (zone
->lowmem_reserve
[j
] > max
)
2931 max
= zone
->lowmem_reserve
[j
];
2934 /* we treat pages_high as reserved pages. */
2935 max
+= zone
->pages_high
;
2937 if (max
> zone
->present_pages
)
2938 max
= zone
->present_pages
;
2939 reserve_pages
+= max
;
2942 totalreserve_pages
= reserve_pages
;
2946 * setup_per_zone_lowmem_reserve - called whenever
2947 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
2948 * has a correct pages reserved value, so an adequate number of
2949 * pages are left in the zone after a successful __alloc_pages().
2951 static void setup_per_zone_lowmem_reserve(void)
2953 struct pglist_data
*pgdat
;
2954 enum zone_type j
, idx
;
2956 for_each_online_pgdat(pgdat
) {
2957 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
2958 struct zone
*zone
= pgdat
->node_zones
+ j
;
2959 unsigned long present_pages
= zone
->present_pages
;
2961 zone
->lowmem_reserve
[j
] = 0;
2965 struct zone
*lower_zone
;
2969 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
2970 sysctl_lowmem_reserve_ratio
[idx
] = 1;
2972 lower_zone
= pgdat
->node_zones
+ idx
;
2973 lower_zone
->lowmem_reserve
[j
] = present_pages
/
2974 sysctl_lowmem_reserve_ratio
[idx
];
2975 present_pages
+= lower_zone
->present_pages
;
2980 /* update totalreserve_pages */
2981 calculate_totalreserve_pages();
2985 * setup_per_zone_pages_min - called when min_free_kbytes changes.
2987 * Ensures that the pages_{min,low,high} values for each zone are set correctly
2988 * with respect to min_free_kbytes.
2990 void setup_per_zone_pages_min(void)
2992 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
2993 unsigned long lowmem_pages
= 0;
2995 unsigned long flags
;
2997 /* Calculate total number of !ZONE_HIGHMEM pages */
2998 for_each_zone(zone
) {
2999 if (!is_highmem(zone
))
3000 lowmem_pages
+= zone
->present_pages
;
3003 for_each_zone(zone
) {
3006 spin_lock_irqsave(&zone
->lru_lock
, flags
);
3007 tmp
= (u64
)pages_min
* zone
->present_pages
;
3008 do_div(tmp
, lowmem_pages
);
3009 if (is_highmem(zone
)) {
3011 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
3012 * need highmem pages, so cap pages_min to a small
3015 * The (pages_high-pages_low) and (pages_low-pages_min)
3016 * deltas controls asynch page reclaim, and so should
3017 * not be capped for highmem.
3021 min_pages
= zone
->present_pages
/ 1024;
3022 if (min_pages
< SWAP_CLUSTER_MAX
)
3023 min_pages
= SWAP_CLUSTER_MAX
;
3024 if (min_pages
> 128)
3026 zone
->pages_min
= min_pages
;
3029 * If it's a lowmem zone, reserve a number of pages
3030 * proportionate to the zone's size.
3032 zone
->pages_min
= tmp
;
3035 zone
->pages_low
= zone
->pages_min
+ (tmp
>> 2);
3036 zone
->pages_high
= zone
->pages_min
+ (tmp
>> 1);
3037 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
3040 /* update totalreserve_pages */
3041 calculate_totalreserve_pages();
3045 * Initialise min_free_kbytes.
3047 * For small machines we want it small (128k min). For large machines
3048 * we want it large (64MB max). But it is not linear, because network
3049 * bandwidth does not increase linearly with machine size. We use
3051 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
3052 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
3068 static int __init
init_per_zone_pages_min(void)
3070 unsigned long lowmem_kbytes
;
3072 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
3074 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
3075 if (min_free_kbytes
< 128)
3076 min_free_kbytes
= 128;
3077 if (min_free_kbytes
> 65536)
3078 min_free_kbytes
= 65536;
3079 setup_per_zone_pages_min();
3080 setup_per_zone_lowmem_reserve();
3083 module_init(init_per_zone_pages_min
)
3086 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
3087 * that we can call two helper functions whenever min_free_kbytes
3090 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
3091 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
3093 proc_dointvec(table
, write
, file
, buffer
, length
, ppos
);
3094 setup_per_zone_pages_min();
3099 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
3100 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
3105 rc
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
3110 zone
->min_unmapped_pages
= (zone
->present_pages
*
3111 sysctl_min_unmapped_ratio
) / 100;
3115 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
3116 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
3121 rc
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
3126 zone
->min_slab_pages
= (zone
->present_pages
*
3127 sysctl_min_slab_ratio
) / 100;
3133 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
3134 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
3135 * whenever sysctl_lowmem_reserve_ratio changes.
3137 * The reserve ratio obviously has absolutely no relation with the
3138 * pages_min watermarks. The lowmem reserve ratio can only make sense
3139 * if in function of the boot time zone sizes.
3141 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
3142 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
3144 proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
3145 setup_per_zone_lowmem_reserve();
3150 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
3151 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
3152 * can have before it gets flushed back to buddy allocator.
3155 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
3156 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
3162 ret
= proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
3163 if (!write
|| (ret
== -EINVAL
))
3165 for_each_zone(zone
) {
3166 for_each_online_cpu(cpu
) {
3168 high
= zone
->present_pages
/ percpu_pagelist_fraction
;
3169 setup_pagelist_highmark(zone_pcp(zone
, cpu
), high
);
3175 int hashdist
= HASHDIST_DEFAULT
;
3178 static int __init
set_hashdist(char *str
)
3182 hashdist
= simple_strtoul(str
, &str
, 0);
3185 __setup("hashdist=", set_hashdist
);
3189 * allocate a large system hash table from bootmem
3190 * - it is assumed that the hash table must contain an exact power-of-2
3191 * quantity of entries
3192 * - limit is the number of hash buckets, not the total allocation size
3194 void *__init
alloc_large_system_hash(const char *tablename
,
3195 unsigned long bucketsize
,
3196 unsigned long numentries
,
3199 unsigned int *_hash_shift
,
3200 unsigned int *_hash_mask
,
3201 unsigned long limit
)
3203 unsigned long long max
= limit
;
3204 unsigned long log2qty
, size
;
3207 /* allow the kernel cmdline to have a say */
3209 /* round applicable memory size up to nearest megabyte */
3210 numentries
= (flags
& HASH_HIGHMEM
) ? nr_all_pages
: nr_kernel_pages
;
3211 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
3212 numentries
>>= 20 - PAGE_SHIFT
;
3213 numentries
<<= 20 - PAGE_SHIFT
;
3215 /* limit to 1 bucket per 2^scale bytes of low memory */
3216 if (scale
> PAGE_SHIFT
)
3217 numentries
>>= (scale
- PAGE_SHIFT
);
3219 numentries
<<= (PAGE_SHIFT
- scale
);
3221 numentries
= roundup_pow_of_two(numentries
);
3223 /* limit allocation size to 1/16 total memory by default */
3225 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
3226 do_div(max
, bucketsize
);
3229 if (numentries
> max
)
3232 log2qty
= long_log2(numentries
);
3235 size
= bucketsize
<< log2qty
;
3236 if (flags
& HASH_EARLY
)
3237 table
= alloc_bootmem(size
);
3239 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
3241 unsigned long order
;
3242 for (order
= 0; ((1UL << order
) << PAGE_SHIFT
) < size
; order
++)
3244 table
= (void*) __get_free_pages(GFP_ATOMIC
, order
);
3246 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
3249 panic("Failed to allocate %s hash table\n", tablename
);
3251 printk("%s hash table entries: %d (order: %d, %lu bytes)\n",
3254 long_log2(size
) - PAGE_SHIFT
,
3258 *_hash_shift
= log2qty
;
3260 *_hash_mask
= (1 << log2qty
) - 1;
3265 #ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
3266 struct page
*pfn_to_page(unsigned long pfn
)
3268 return __pfn_to_page(pfn
);
3270 unsigned long page_to_pfn(struct page
*page
)
3272 return __page_to_pfn(page
);
3274 EXPORT_SYMBOL(pfn_to_page
);
3275 EXPORT_SYMBOL(page_to_pfn
);
3276 #endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */
3278 #if MAX_NUMNODES > 1
3280 * Find the highest possible node id.
3282 int highest_possible_node_id(void)
3285 unsigned int highest
= 0;
3287 for_each_node_mask(node
, node_possible_map
)
3291 EXPORT_SYMBOL(highest_possible_node_id
);