2 * linux/mm/page_alloc.c
4 * Manages the free list, the system allocates free pages here.
5 * Note that kmalloc() lives in slab.c
7 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
8 * Swap reorganised 29.12.95, Stephen Tweedie
9 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
10 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
11 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
12 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000
13 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
14 * (lots of bits borrowed from Ingo Molnar & Andrew Morton)
17 #include <linux/config.h>
18 #include <linux/stddef.h>
20 #include <linux/swap.h>
21 #include <linux/interrupt.h>
22 #include <linux/pagemap.h>
23 #include <linux/bootmem.h>
24 #include <linux/compiler.h>
25 #include <linux/kernel.h>
26 #include <linux/module.h>
27 #include <linux/suspend.h>
28 #include <linux/pagevec.h>
29 #include <linux/blkdev.h>
30 #include <linux/slab.h>
31 #include <linux/notifier.h>
32 #include <linux/topology.h>
33 #include <linux/sysctl.h>
34 #include <linux/cpu.h>
35 #include <linux/cpuset.h>
36 #include <linux/memory_hotplug.h>
37 #include <linux/nodemask.h>
38 #include <linux/vmalloc.h>
40 #include <asm/tlbflush.h>
44 * MCD - HACK: Find somewhere to initialize this EARLY, or make this
47 nodemask_t node_online_map __read_mostly
= { { [0] = 1UL } };
48 EXPORT_SYMBOL(node_online_map
);
49 nodemask_t node_possible_map __read_mostly
= NODE_MASK_ALL
;
50 EXPORT_SYMBOL(node_possible_map
);
51 struct pglist_data
*pgdat_list __read_mostly
;
52 unsigned long totalram_pages __read_mostly
;
53 unsigned long totalhigh_pages __read_mostly
;
57 * results with 256, 32 in the lowmem_reserve sysctl:
58 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
59 * 1G machine -> (16M dma, 784M normal, 224M high)
60 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
61 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
62 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
64 * TBD: should special case ZONE_DMA32 machines here - in those we normally
65 * don't need any ZONE_NORMAL reservation
67 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = { 256, 256, 32 };
69 EXPORT_SYMBOL(totalram_pages
);
72 * Used by page_zone() to look up the address of the struct zone whose
73 * id is encoded in the upper bits of page->flags
75 struct zone
*zone_table
[1 << ZONETABLE_SHIFT
] __read_mostly
;
76 EXPORT_SYMBOL(zone_table
);
78 static char *zone_names
[MAX_NR_ZONES
] = { "DMA", "DMA32", "Normal", "HighMem" };
79 int min_free_kbytes
= 1024;
81 unsigned long __initdata nr_kernel_pages
;
82 unsigned long __initdata nr_all_pages
;
84 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
88 unsigned long pfn
= page_to_pfn(page
);
91 seq
= zone_span_seqbegin(zone
);
92 if (pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
94 else if (pfn
< zone
->zone_start_pfn
)
96 } while (zone_span_seqretry(zone
, seq
));
101 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
103 #ifdef CONFIG_HOLES_IN_ZONE
104 if (!pfn_valid(page_to_pfn(page
)))
107 if (zone
!= page_zone(page
))
113 * Temporary debugging check for pages not lying within a given zone.
115 static int bad_range(struct zone
*zone
, struct page
*page
)
117 if (page_outside_zone_boundaries(zone
, page
))
119 if (!page_is_consistent(zone
, page
))
125 static void bad_page(const char *function
, struct page
*page
)
127 printk(KERN_EMERG
"Bad page state at %s (in process '%s', page %p)\n",
128 function
, current
->comm
, page
);
129 printk(KERN_EMERG
"flags:0x%0*lx mapping:%p mapcount:%d count:%d\n",
130 (int)(2*sizeof(unsigned long)), (unsigned long)page
->flags
,
131 page
->mapping
, page_mapcount(page
), page_count(page
));
132 printk(KERN_EMERG
"Backtrace:\n");
134 printk(KERN_EMERG
"Trying to fix it up, but a reboot is needed\n");
135 page
->flags
&= ~(1 << PG_lru
|
144 set_page_count(page
, 0);
145 reset_page_mapcount(page
);
146 page
->mapping
= NULL
;
147 add_taint(TAINT_BAD_PAGE
);
151 * Higher-order pages are called "compound pages". They are structured thusly:
153 * The first PAGE_SIZE page is called the "head page".
155 * The remaining PAGE_SIZE pages are called "tail pages".
157 * All pages have PG_compound set. All pages have their ->private pointing at
158 * the head page (even the head page has this).
160 * The first tail page's ->mapping, if non-zero, holds the address of the
161 * compound page's put_page() function.
163 * The order of the allocation is stored in the first tail page's ->index
164 * This is only for debug at present. This usage means that zero-order pages
165 * may not be compound.
167 static void prep_compound_page(struct page
*page
, unsigned long order
)
170 int nr_pages
= 1 << order
;
172 page
[1].mapping
= NULL
;
173 page
[1].index
= order
;
174 for (i
= 0; i
< nr_pages
; i
++) {
175 struct page
*p
= page
+ i
;
178 set_page_private(p
, (unsigned long)page
);
182 static void destroy_compound_page(struct page
*page
, unsigned long order
)
185 int nr_pages
= 1 << order
;
187 if (!PageCompound(page
))
190 if (page
[1].index
!= order
)
191 bad_page(__FUNCTION__
, page
);
193 for (i
= 0; i
< nr_pages
; i
++) {
194 struct page
*p
= page
+ i
;
196 if (!PageCompound(p
))
197 bad_page(__FUNCTION__
, page
);
198 if (page_private(p
) != (unsigned long)page
)
199 bad_page(__FUNCTION__
, page
);
200 ClearPageCompound(p
);
205 * function for dealing with page's order in buddy system.
206 * zone->lock is already acquired when we use these.
207 * So, we don't need atomic page->flags operations here.
209 static inline unsigned long page_order(struct page
*page
) {
210 return page_private(page
);
213 static inline void set_page_order(struct page
*page
, int order
) {
214 set_page_private(page
, order
);
215 __SetPagePrivate(page
);
218 static inline void rmv_page_order(struct page
*page
)
220 __ClearPagePrivate(page
);
221 set_page_private(page
, 0);
225 * Locate the struct page for both the matching buddy in our
226 * pair (buddy1) and the combined O(n+1) page they form (page).
228 * 1) Any buddy B1 will have an order O twin B2 which satisfies
229 * the following equation:
231 * For example, if the starting buddy (buddy2) is #8 its order
233 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
235 * 2) Any buddy B will have an order O+1 parent P which
236 * satisfies the following equation:
239 * Assumption: *_mem_map is contigious at least up to MAX_ORDER
241 static inline struct page
*
242 __page_find_buddy(struct page
*page
, unsigned long page_idx
, unsigned int order
)
244 unsigned long buddy_idx
= page_idx
^ (1 << order
);
246 return page
+ (buddy_idx
- page_idx
);
249 static inline unsigned long
250 __find_combined_index(unsigned long page_idx
, unsigned int order
)
252 return (page_idx
& ~(1 << order
));
256 * This function checks whether a page is free && is the buddy
257 * we can do coalesce a page and its buddy if
258 * (a) the buddy is free &&
259 * (b) the buddy is on the buddy system &&
260 * (c) a page and its buddy have the same order.
261 * for recording page's order, we use page_private(page) and PG_private.
264 static inline int page_is_buddy(struct page
*page
, int order
)
266 if (PagePrivate(page
) &&
267 (page_order(page
) == order
) &&
268 page_count(page
) == 0)
274 * Freeing function for a buddy system allocator.
276 * The concept of a buddy system is to maintain direct-mapped table
277 * (containing bit values) for memory blocks of various "orders".
278 * The bottom level table contains the map for the smallest allocatable
279 * units of memory (here, pages), and each level above it describes
280 * pairs of units from the levels below, hence, "buddies".
281 * At a high level, all that happens here is marking the table entry
282 * at the bottom level available, and propagating the changes upward
283 * as necessary, plus some accounting needed to play nicely with other
284 * parts of the VM system.
285 * At each level, we keep a list of pages, which are heads of continuous
286 * free pages of length of (1 << order) and marked with PG_Private.Page's
287 * order is recorded in page_private(page) field.
288 * So when we are allocating or freeing one, we can derive the state of the
289 * other. That is, if we allocate a small block, and both were
290 * free, the remainder of the region must be split into blocks.
291 * If a block is freed, and its buddy is also free, then this
292 * triggers coalescing into a block of larger size.
297 static inline void __free_pages_bulk (struct page
*page
,
298 struct zone
*zone
, unsigned int order
)
300 unsigned long page_idx
;
301 int order_size
= 1 << order
;
304 destroy_compound_page(page
, order
);
306 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
308 BUG_ON(page_idx
& (order_size
- 1));
309 BUG_ON(bad_range(zone
, page
));
311 zone
->free_pages
+= order_size
;
312 while (order
< MAX_ORDER
-1) {
313 unsigned long combined_idx
;
314 struct free_area
*area
;
317 combined_idx
= __find_combined_index(page_idx
, order
);
318 buddy
= __page_find_buddy(page
, page_idx
, order
);
320 if (bad_range(zone
, buddy
))
322 if (!page_is_buddy(buddy
, order
))
323 break; /* Move the buddy up one level. */
324 list_del(&buddy
->lru
);
325 area
= zone
->free_area
+ order
;
327 rmv_page_order(buddy
);
328 page
= page
+ (combined_idx
- page_idx
);
329 page_idx
= combined_idx
;
332 set_page_order(page
, order
);
333 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
);
334 zone
->free_area
[order
].nr_free
++;
337 static inline int free_pages_check(const char *function
, struct page
*page
)
339 if (unlikely(page_mapcount(page
) |
340 (page
->mapping
!= NULL
) |
341 (page_count(page
) != 0) |
351 1 << PG_reserved
))))
352 bad_page(function
, page
);
354 __ClearPageDirty(page
);
356 * For now, we report if PG_reserved was found set, but do not
357 * clear it, and do not free the page. But we shall soon need
358 * to do more, for when the ZERO_PAGE count wraps negative.
360 return PageReserved(page
);
364 * Frees a list of pages.
365 * Assumes all pages on list are in same zone, and of same order.
366 * count is the number of pages to free.
368 * If the zone was previously in an "all pages pinned" state then look to
369 * see if this freeing clears that state.
371 * And clear the zone's pages_scanned counter, to hold off the "all pages are
372 * pinned" detection logic.
375 free_pages_bulk(struct zone
*zone
, int count
,
376 struct list_head
*list
, unsigned int order
)
378 struct page
*page
= NULL
;
381 spin_lock(&zone
->lock
);
382 zone
->all_unreclaimable
= 0;
383 zone
->pages_scanned
= 0;
384 while (!list_empty(list
) && count
--) {
385 page
= list_entry(list
->prev
, struct page
, lru
);
386 /* have to delete it as __free_pages_bulk list manipulates */
387 list_del(&page
->lru
);
388 __free_pages_bulk(page
, zone
, order
);
391 spin_unlock(&zone
->lock
);
395 void __free_pages_ok(struct page
*page
, unsigned int order
)
402 arch_free_page(page
, order
);
406 for (i
= 1 ; i
< (1 << order
) ; ++i
)
407 __put_page(page
+ i
);
410 for (i
= 0 ; i
< (1 << order
) ; ++i
)
411 reserved
+= free_pages_check(__FUNCTION__
, page
+ i
);
415 list_add(&page
->lru
, &list
);
416 mod_page_state(pgfree
, 1 << order
);
417 kernel_map_pages(page
, 1<<order
, 0);
418 local_irq_save(flags
);
419 free_pages_bulk(page_zone(page
), 1, &list
, order
);
420 local_irq_restore(flags
);
425 * The order of subdivision here is critical for the IO subsystem.
426 * Please do not alter this order without good reasons and regression
427 * testing. Specifically, as large blocks of memory are subdivided,
428 * the order in which smaller blocks are delivered depends on the order
429 * they're subdivided in this function. This is the primary factor
430 * influencing the order in which pages are delivered to the IO
431 * subsystem according to empirical testing, and this is also justified
432 * by considering the behavior of a buddy system containing a single
433 * large block of memory acted on by a series of small allocations.
434 * This behavior is a critical factor in sglist merging's success.
438 static inline struct page
*
439 expand(struct zone
*zone
, struct page
*page
,
440 int low
, int high
, struct free_area
*area
)
442 unsigned long size
= 1 << high
;
448 BUG_ON(bad_range(zone
, &page
[size
]));
449 list_add(&page
[size
].lru
, &area
->free_list
);
451 set_page_order(&page
[size
], high
);
457 * This page is about to be returned from the page allocator
459 static int prep_new_page(struct page
*page
, int order
)
461 if (unlikely(page_mapcount(page
) |
462 (page
->mapping
!= NULL
) |
463 (page_count(page
) != 0) |
474 1 << PG_reserved
))))
475 bad_page(__FUNCTION__
, page
);
478 * For now, we report if PG_reserved was found set, but do not
479 * clear it, and do not allocate the page: as a safety net.
481 if (PageReserved(page
))
484 page
->flags
&= ~(1 << PG_uptodate
| 1 << PG_error
|
485 1 << PG_referenced
| 1 << PG_arch_1
|
486 1 << PG_checked
| 1 << PG_mappedtodisk
);
487 set_page_private(page
, 0);
488 set_page_refs(page
, order
);
489 kernel_map_pages(page
, 1 << order
, 1);
494 * Do the hard work of removing an element from the buddy allocator.
495 * Call me with the zone->lock already held.
497 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
)
499 struct free_area
* area
;
500 unsigned int current_order
;
503 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
504 area
= zone
->free_area
+ current_order
;
505 if (list_empty(&area
->free_list
))
508 page
= list_entry(area
->free_list
.next
, struct page
, lru
);
509 list_del(&page
->lru
);
510 rmv_page_order(page
);
512 zone
->free_pages
-= 1UL << order
;
513 return expand(zone
, page
, order
, current_order
, area
);
520 * Obtain a specified number of elements from the buddy allocator, all under
521 * a single hold of the lock, for efficiency. Add them to the supplied list.
522 * Returns the number of new pages which were placed at *list.
524 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
525 unsigned long count
, struct list_head
*list
)
531 spin_lock(&zone
->lock
);
532 for (i
= 0; i
< count
; ++i
) {
533 page
= __rmqueue(zone
, order
);
537 list_add_tail(&page
->lru
, list
);
539 spin_unlock(&zone
->lock
);
544 /* Called from the slab reaper to drain remote pagesets */
545 void drain_remote_pages(void)
551 local_irq_save(flags
);
552 for_each_zone(zone
) {
553 struct per_cpu_pageset
*pset
;
555 /* Do not drain local pagesets */
556 if (zone
->zone_pgdat
->node_id
== numa_node_id())
559 pset
= zone
->pageset
[smp_processor_id()];
560 for (i
= 0; i
< ARRAY_SIZE(pset
->pcp
); i
++) {
561 struct per_cpu_pages
*pcp
;
565 pcp
->count
-= free_pages_bulk(zone
, pcp
->count
,
569 local_irq_restore(flags
);
573 #if defined(CONFIG_PM) || defined(CONFIG_HOTPLUG_CPU)
574 static void __drain_pages(unsigned int cpu
)
580 for_each_zone(zone
) {
581 struct per_cpu_pageset
*pset
;
583 pset
= zone_pcp(zone
, cpu
);
584 for (i
= 0; i
< ARRAY_SIZE(pset
->pcp
); i
++) {
585 struct per_cpu_pages
*pcp
;
588 local_irq_save(flags
);
589 pcp
->count
-= free_pages_bulk(zone
, pcp
->count
,
591 local_irq_restore(flags
);
595 #endif /* CONFIG_PM || CONFIG_HOTPLUG_CPU */
599 void mark_free_pages(struct zone
*zone
)
601 unsigned long zone_pfn
, flags
;
603 struct list_head
*curr
;
605 if (!zone
->spanned_pages
)
608 spin_lock_irqsave(&zone
->lock
, flags
);
609 for (zone_pfn
= 0; zone_pfn
< zone
->spanned_pages
; ++zone_pfn
)
610 ClearPageNosaveFree(pfn_to_page(zone_pfn
+ zone
->zone_start_pfn
));
612 for (order
= MAX_ORDER
- 1; order
>= 0; --order
)
613 list_for_each(curr
, &zone
->free_area
[order
].free_list
) {
614 unsigned long start_pfn
, i
;
616 start_pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
618 for (i
=0; i
< (1<<order
); i
++)
619 SetPageNosaveFree(pfn_to_page(start_pfn
+i
));
621 spin_unlock_irqrestore(&zone
->lock
, flags
);
625 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
627 void drain_local_pages(void)
631 local_irq_save(flags
);
632 __drain_pages(smp_processor_id());
633 local_irq_restore(flags
);
635 #endif /* CONFIG_PM */
637 static void zone_statistics(struct zonelist
*zonelist
, struct zone
*z
)
642 pg_data_t
*pg
= z
->zone_pgdat
;
643 pg_data_t
*orig
= zonelist
->zones
[0]->zone_pgdat
;
644 struct per_cpu_pageset
*p
;
646 local_irq_save(flags
);
647 cpu
= smp_processor_id();
653 zone_pcp(zonelist
->zones
[0], cpu
)->numa_foreign
++;
655 if (pg
== NODE_DATA(numa_node_id()))
659 local_irq_restore(flags
);
664 * Free a 0-order page
666 static void FASTCALL(free_hot_cold_page(struct page
*page
, int cold
));
667 static void fastcall
free_hot_cold_page(struct page
*page
, int cold
)
669 struct zone
*zone
= page_zone(page
);
670 struct per_cpu_pages
*pcp
;
673 arch_free_page(page
, 0);
676 page
->mapping
= NULL
;
677 if (free_pages_check(__FUNCTION__
, page
))
680 inc_page_state(pgfree
);
681 kernel_map_pages(page
, 1, 0);
683 pcp
= &zone_pcp(zone
, get_cpu())->pcp
[cold
];
684 local_irq_save(flags
);
685 list_add(&page
->lru
, &pcp
->list
);
687 if (pcp
->count
>= pcp
->high
)
688 pcp
->count
-= free_pages_bulk(zone
, pcp
->batch
, &pcp
->list
, 0);
689 local_irq_restore(flags
);
693 void fastcall
free_hot_page(struct page
*page
)
695 free_hot_cold_page(page
, 0);
698 void fastcall
free_cold_page(struct page
*page
)
700 free_hot_cold_page(page
, 1);
703 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
707 BUG_ON((gfp_flags
& (__GFP_WAIT
| __GFP_HIGHMEM
)) == __GFP_HIGHMEM
);
708 for(i
= 0; i
< (1 << order
); i
++)
709 clear_highpage(page
+ i
);
713 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
714 * we cheat by calling it from here, in the order > 0 path. Saves a branch
718 buffered_rmqueue(struct zone
*zone
, int order
, gfp_t gfp_flags
)
722 int cold
= !!(gfp_flags
& __GFP_COLD
);
726 struct per_cpu_pages
*pcp
;
729 pcp
= &zone_pcp(zone
, get_cpu())->pcp
[cold
];
730 local_irq_save(flags
);
731 if (pcp
->count
<= pcp
->low
)
732 pcp
->count
+= rmqueue_bulk(zone
, 0,
733 pcp
->batch
, &pcp
->list
);
734 if (likely(pcp
->count
)) {
735 page
= list_entry(pcp
->list
.next
, struct page
, lru
);
736 list_del(&page
->lru
);
739 local_irq_restore(flags
);
742 spin_lock_irqsave(&zone
->lock
, flags
);
743 page
= __rmqueue(zone
, order
);
744 spin_unlock_irqrestore(&zone
->lock
, flags
);
748 BUG_ON(bad_range(zone
, page
));
749 mod_page_state_zone(zone
, pgalloc
, 1 << order
);
750 if (prep_new_page(page
, order
))
753 if (gfp_flags
& __GFP_ZERO
)
754 prep_zero_page(page
, order
, gfp_flags
);
756 if (order
&& (gfp_flags
& __GFP_COMP
))
757 prep_compound_page(page
, order
);
762 #define ALLOC_NO_WATERMARKS 0x01 /* don't check watermarks at all */
763 #define ALLOC_WMARK_MIN 0x02 /* use pages_min watermark */
764 #define ALLOC_WMARK_LOW 0x04 /* use pages_low watermark */
765 #define ALLOC_WMARK_HIGH 0x08 /* use pages_high watermark */
766 #define ALLOC_HARDER 0x10 /* try to alloc harder */
767 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
768 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
771 * Return 1 if free pages are above 'mark'. This takes into account the order
774 int zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
775 int classzone_idx
, int alloc_flags
)
777 /* free_pages my go negative - that's OK */
778 long min
= mark
, free_pages
= z
->free_pages
- (1 << order
) + 1;
781 if (alloc_flags
& ALLOC_HIGH
)
783 if (alloc_flags
& ALLOC_HARDER
)
786 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
788 for (o
= 0; o
< order
; o
++) {
789 /* At the next order, this order's pages become unavailable */
790 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
792 /* Require fewer higher order pages to be free */
795 if (free_pages
<= min
)
802 * get_page_from_freeliest goes through the zonelist trying to allocate
806 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
,
807 struct zonelist
*zonelist
, int alloc_flags
)
809 struct zone
**z
= zonelist
->zones
;
810 struct page
*page
= NULL
;
811 int classzone_idx
= zone_idx(*z
);
814 * Go through the zonelist once, looking for a zone with enough free.
815 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
818 if ((alloc_flags
& ALLOC_CPUSET
) &&
819 !cpuset_zone_allowed(*z
, gfp_mask
))
822 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
824 if (alloc_flags
& ALLOC_WMARK_MIN
)
825 mark
= (*z
)->pages_min
;
826 else if (alloc_flags
& ALLOC_WMARK_LOW
)
827 mark
= (*z
)->pages_low
;
829 mark
= (*z
)->pages_high
;
830 if (!zone_watermark_ok(*z
, order
, mark
,
831 classzone_idx
, alloc_flags
))
835 page
= buffered_rmqueue(*z
, order
, gfp_mask
);
837 zone_statistics(zonelist
, *z
);
840 } while (*(++z
) != NULL
);
845 * This is the 'heart' of the zoned buddy allocator.
847 struct page
* fastcall
848 __alloc_pages(gfp_t gfp_mask
, unsigned int order
,
849 struct zonelist
*zonelist
)
851 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
854 struct reclaim_state reclaim_state
;
855 struct task_struct
*p
= current
;
858 int did_some_progress
;
860 might_sleep_if(wait
);
863 z
= zonelist
->zones
; /* the list of zones suitable for gfp_mask */
865 if (unlikely(*z
== NULL
)) {
866 /* Should this ever happen?? */
870 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, order
,
871 zonelist
, ALLOC_WMARK_LOW
|ALLOC_CPUSET
);
876 wakeup_kswapd(*z
, order
);
880 * OK, we're below the kswapd watermark and have kicked background
881 * reclaim. Now things get more complex, so set up alloc_flags according
882 * to how we want to proceed.
884 * The caller may dip into page reserves a bit more if the caller
885 * cannot run direct reclaim, or if the caller has realtime scheduling
888 alloc_flags
= ALLOC_WMARK_MIN
;
889 if ((unlikely(rt_task(p
)) && !in_interrupt()) || !wait
)
890 alloc_flags
|= ALLOC_HARDER
;
891 if (gfp_mask
& __GFP_HIGH
)
892 alloc_flags
|= ALLOC_HIGH
;
893 alloc_flags
|= ALLOC_CPUSET
;
896 * Go through the zonelist again. Let __GFP_HIGH and allocations
897 * coming from realtime tasks go deeper into reserves.
899 * This is the last chance, in general, before the goto nopage.
900 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
901 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
903 page
= get_page_from_freelist(gfp_mask
, order
, zonelist
, alloc_flags
);
907 /* This allocation should allow future memory freeing. */
909 if (((p
->flags
& PF_MEMALLOC
) || unlikely(test_thread_flag(TIF_MEMDIE
)))
910 && !in_interrupt()) {
911 if (!(gfp_mask
& __GFP_NOMEMALLOC
)) {
913 /* go through the zonelist yet again, ignoring mins */
914 page
= get_page_from_freelist(gfp_mask
, order
,
915 zonelist
, ALLOC_NO_WATERMARKS
);
918 if (gfp_mask
& __GFP_NOFAIL
) {
919 blk_congestion_wait(WRITE
, HZ
/50);
926 /* Atomic allocations - we can't balance anything */
933 /* We now go into synchronous reclaim */
934 p
->flags
|= PF_MEMALLOC
;
935 reclaim_state
.reclaimed_slab
= 0;
936 p
->reclaim_state
= &reclaim_state
;
938 did_some_progress
= try_to_free_pages(zonelist
->zones
, gfp_mask
);
940 p
->reclaim_state
= NULL
;
941 p
->flags
&= ~PF_MEMALLOC
;
945 if (likely(did_some_progress
)) {
946 page
= get_page_from_freelist(gfp_mask
, order
,
947 zonelist
, alloc_flags
);
950 } else if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
952 * Go through the zonelist yet one more time, keep
953 * very high watermark here, this is only to catch
954 * a parallel oom killing, we must fail if we're still
955 * under heavy pressure.
957 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, order
,
958 zonelist
, ALLOC_WMARK_HIGH
|ALLOC_CPUSET
);
962 out_of_memory(gfp_mask
, order
);
967 * Don't let big-order allocations loop unless the caller explicitly
968 * requests that. Wait for some write requests to complete then retry.
970 * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order
971 * <= 3, but that may not be true in other implementations.
974 if (!(gfp_mask
& __GFP_NORETRY
)) {
975 if ((order
<= 3) || (gfp_mask
& __GFP_REPEAT
))
977 if (gfp_mask
& __GFP_NOFAIL
)
981 blk_congestion_wait(WRITE
, HZ
/50);
986 if (!(gfp_mask
& __GFP_NOWARN
) && printk_ratelimit()) {
987 printk(KERN_WARNING
"%s: page allocation failure."
988 " order:%d, mode:0x%x\n",
989 p
->comm
, order
, gfp_mask
);
997 EXPORT_SYMBOL(__alloc_pages
);
1000 * Common helper functions.
1002 fastcall
unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
1005 page
= alloc_pages(gfp_mask
, order
);
1008 return (unsigned long) page_address(page
);
1011 EXPORT_SYMBOL(__get_free_pages
);
1013 fastcall
unsigned long get_zeroed_page(gfp_t gfp_mask
)
1018 * get_zeroed_page() returns a 32-bit address, which cannot represent
1021 BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
1023 page
= alloc_pages(gfp_mask
| __GFP_ZERO
, 0);
1025 return (unsigned long) page_address(page
);
1029 EXPORT_SYMBOL(get_zeroed_page
);
1031 void __pagevec_free(struct pagevec
*pvec
)
1033 int i
= pagevec_count(pvec
);
1036 free_hot_cold_page(pvec
->pages
[i
], pvec
->cold
);
1039 fastcall
void __free_pages(struct page
*page
, unsigned int order
)
1041 if (put_page_testzero(page
)) {
1043 free_hot_page(page
);
1045 __free_pages_ok(page
, order
);
1049 EXPORT_SYMBOL(__free_pages
);
1051 fastcall
void free_pages(unsigned long addr
, unsigned int order
)
1054 BUG_ON(!virt_addr_valid((void *)addr
));
1055 __free_pages(virt_to_page((void *)addr
), order
);
1059 EXPORT_SYMBOL(free_pages
);
1062 * Total amount of free (allocatable) RAM:
1064 unsigned int nr_free_pages(void)
1066 unsigned int sum
= 0;
1070 sum
+= zone
->free_pages
;
1075 EXPORT_SYMBOL(nr_free_pages
);
1078 unsigned int nr_free_pages_pgdat(pg_data_t
*pgdat
)
1080 unsigned int i
, sum
= 0;
1082 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
1083 sum
+= pgdat
->node_zones
[i
].free_pages
;
1089 static unsigned int nr_free_zone_pages(int offset
)
1091 /* Just pick one node, since fallback list is circular */
1092 pg_data_t
*pgdat
= NODE_DATA(numa_node_id());
1093 unsigned int sum
= 0;
1095 struct zonelist
*zonelist
= pgdat
->node_zonelists
+ offset
;
1096 struct zone
**zonep
= zonelist
->zones
;
1099 for (zone
= *zonep
++; zone
; zone
= *zonep
++) {
1100 unsigned long size
= zone
->present_pages
;
1101 unsigned long high
= zone
->pages_high
;
1110 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
1112 unsigned int nr_free_buffer_pages(void)
1114 return nr_free_zone_pages(gfp_zone(GFP_USER
));
1118 * Amount of free RAM allocatable within all zones
1120 unsigned int nr_free_pagecache_pages(void)
1122 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER
));
1125 #ifdef CONFIG_HIGHMEM
1126 unsigned int nr_free_highpages (void)
1129 unsigned int pages
= 0;
1131 for_each_pgdat(pgdat
)
1132 pages
+= pgdat
->node_zones
[ZONE_HIGHMEM
].free_pages
;
1139 static void show_node(struct zone
*zone
)
1141 printk("Node %d ", zone
->zone_pgdat
->node_id
);
1144 #define show_node(zone) do { } while (0)
1148 * Accumulate the page_state information across all CPUs.
1149 * The result is unavoidably approximate - it can change
1150 * during and after execution of this function.
1152 static DEFINE_PER_CPU(struct page_state
, page_states
) = {0};
1154 atomic_t nr_pagecache
= ATOMIC_INIT(0);
1155 EXPORT_SYMBOL(nr_pagecache
);
1157 DEFINE_PER_CPU(long, nr_pagecache_local
) = 0;
1160 void __get_page_state(struct page_state
*ret
, int nr
, cpumask_t
*cpumask
)
1164 memset(ret
, 0, sizeof(*ret
));
1165 cpus_and(*cpumask
, *cpumask
, cpu_online_map
);
1167 cpu
= first_cpu(*cpumask
);
1168 while (cpu
< NR_CPUS
) {
1169 unsigned long *in
, *out
, off
;
1171 in
= (unsigned long *)&per_cpu(page_states
, cpu
);
1173 cpu
= next_cpu(cpu
, *cpumask
);
1176 prefetch(&per_cpu(page_states
, cpu
));
1178 out
= (unsigned long *)ret
;
1179 for (off
= 0; off
< nr
; off
++)
1184 void get_page_state_node(struct page_state
*ret
, int node
)
1187 cpumask_t mask
= node_to_cpumask(node
);
1189 nr
= offsetof(struct page_state
, GET_PAGE_STATE_LAST
);
1190 nr
/= sizeof(unsigned long);
1192 __get_page_state(ret
, nr
+1, &mask
);
1195 void get_page_state(struct page_state
*ret
)
1198 cpumask_t mask
= CPU_MASK_ALL
;
1200 nr
= offsetof(struct page_state
, GET_PAGE_STATE_LAST
);
1201 nr
/= sizeof(unsigned long);
1203 __get_page_state(ret
, nr
+ 1, &mask
);
1206 void get_full_page_state(struct page_state
*ret
)
1208 cpumask_t mask
= CPU_MASK_ALL
;
1210 __get_page_state(ret
, sizeof(*ret
) / sizeof(unsigned long), &mask
);
1213 unsigned long __read_page_state(unsigned long offset
)
1215 unsigned long ret
= 0;
1218 for_each_online_cpu(cpu
) {
1221 in
= (unsigned long)&per_cpu(page_states
, cpu
) + offset
;
1222 ret
+= *((unsigned long *)in
);
1227 void __mod_page_state(unsigned long offset
, unsigned long delta
)
1229 unsigned long flags
;
1232 local_irq_save(flags
);
1233 ptr
= &__get_cpu_var(page_states
);
1234 *(unsigned long*)(ptr
+ offset
) += delta
;
1235 local_irq_restore(flags
);
1238 EXPORT_SYMBOL(__mod_page_state
);
1240 void __get_zone_counts(unsigned long *active
, unsigned long *inactive
,
1241 unsigned long *free
, struct pglist_data
*pgdat
)
1243 struct zone
*zones
= pgdat
->node_zones
;
1249 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
1250 *active
+= zones
[i
].nr_active
;
1251 *inactive
+= zones
[i
].nr_inactive
;
1252 *free
+= zones
[i
].free_pages
;
1256 void get_zone_counts(unsigned long *active
,
1257 unsigned long *inactive
, unsigned long *free
)
1259 struct pglist_data
*pgdat
;
1264 for_each_pgdat(pgdat
) {
1265 unsigned long l
, m
, n
;
1266 __get_zone_counts(&l
, &m
, &n
, pgdat
);
1273 void si_meminfo(struct sysinfo
*val
)
1275 val
->totalram
= totalram_pages
;
1277 val
->freeram
= nr_free_pages();
1278 val
->bufferram
= nr_blockdev_pages();
1279 #ifdef CONFIG_HIGHMEM
1280 val
->totalhigh
= totalhigh_pages
;
1281 val
->freehigh
= nr_free_highpages();
1286 val
->mem_unit
= PAGE_SIZE
;
1289 EXPORT_SYMBOL(si_meminfo
);
1292 void si_meminfo_node(struct sysinfo
*val
, int nid
)
1294 pg_data_t
*pgdat
= NODE_DATA(nid
);
1296 val
->totalram
= pgdat
->node_present_pages
;
1297 val
->freeram
= nr_free_pages_pgdat(pgdat
);
1298 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
1299 val
->freehigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].free_pages
;
1300 val
->mem_unit
= PAGE_SIZE
;
1304 #define K(x) ((x) << (PAGE_SHIFT-10))
1307 * Show free area list (used inside shift_scroll-lock stuff)
1308 * We also calculate the percentage fragmentation. We do this by counting the
1309 * memory on each free list with the exception of the first item on the list.
1311 void show_free_areas(void)
1313 struct page_state ps
;
1314 int cpu
, temperature
;
1315 unsigned long active
;
1316 unsigned long inactive
;
1320 for_each_zone(zone
) {
1322 printk("%s per-cpu:", zone
->name
);
1324 if (!zone
->present_pages
) {
1330 for_each_online_cpu(cpu
) {
1331 struct per_cpu_pageset
*pageset
;
1333 pageset
= zone_pcp(zone
, cpu
);
1335 for (temperature
= 0; temperature
< 2; temperature
++)
1336 printk("cpu %d %s: low %d, high %d, batch %d used:%d\n",
1338 temperature
? "cold" : "hot",
1339 pageset
->pcp
[temperature
].low
,
1340 pageset
->pcp
[temperature
].high
,
1341 pageset
->pcp
[temperature
].batch
,
1342 pageset
->pcp
[temperature
].count
);
1346 get_page_state(&ps
);
1347 get_zone_counts(&active
, &inactive
, &free
);
1349 printk("Free pages: %11ukB (%ukB HighMem)\n",
1351 K(nr_free_highpages()));
1353 printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu "
1354 "unstable:%lu free:%u slab:%lu mapped:%lu pagetables:%lu\n",
1363 ps
.nr_page_table_pages
);
1365 for_each_zone(zone
) {
1377 " pages_scanned:%lu"
1378 " all_unreclaimable? %s"
1381 K(zone
->free_pages
),
1384 K(zone
->pages_high
),
1386 K(zone
->nr_inactive
),
1387 K(zone
->present_pages
),
1388 zone
->pages_scanned
,
1389 (zone
->all_unreclaimable
? "yes" : "no")
1391 printk("lowmem_reserve[]:");
1392 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
1393 printk(" %lu", zone
->lowmem_reserve
[i
]);
1397 for_each_zone(zone
) {
1398 unsigned long nr
, flags
, order
, total
= 0;
1401 printk("%s: ", zone
->name
);
1402 if (!zone
->present_pages
) {
1407 spin_lock_irqsave(&zone
->lock
, flags
);
1408 for (order
= 0; order
< MAX_ORDER
; order
++) {
1409 nr
= zone
->free_area
[order
].nr_free
;
1410 total
+= nr
<< order
;
1411 printk("%lu*%lukB ", nr
, K(1UL) << order
);
1413 spin_unlock_irqrestore(&zone
->lock
, flags
);
1414 printk("= %lukB\n", K(total
));
1417 show_swap_cache_info();
1421 * Builds allocation fallback zone lists.
1423 static int __init
build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
, int j
, int k
)
1430 zone
= pgdat
->node_zones
+ ZONE_HIGHMEM
;
1431 if (zone
->present_pages
) {
1432 #ifndef CONFIG_HIGHMEM
1435 zonelist
->zones
[j
++] = zone
;
1438 zone
= pgdat
->node_zones
+ ZONE_NORMAL
;
1439 if (zone
->present_pages
)
1440 zonelist
->zones
[j
++] = zone
;
1442 zone
= pgdat
->node_zones
+ ZONE_DMA32
;
1443 if (zone
->present_pages
)
1444 zonelist
->zones
[j
++] = zone
;
1446 zone
= pgdat
->node_zones
+ ZONE_DMA
;
1447 if (zone
->present_pages
)
1448 zonelist
->zones
[j
++] = zone
;
1454 static inline int highest_zone(int zone_bits
)
1456 int res
= ZONE_NORMAL
;
1457 if (zone_bits
& (__force
int)__GFP_HIGHMEM
)
1459 if (zone_bits
& (__force
int)__GFP_DMA32
)
1461 if (zone_bits
& (__force
int)__GFP_DMA
)
1467 #define MAX_NODE_LOAD (num_online_nodes())
1468 static int __initdata node_load
[MAX_NUMNODES
];
1470 * find_next_best_node - find the next node that should appear in a given node's fallback list
1471 * @node: node whose fallback list we're appending
1472 * @used_node_mask: nodemask_t of already used nodes
1474 * We use a number of factors to determine which is the next node that should
1475 * appear on a given node's fallback list. The node should not have appeared
1476 * already in @node's fallback list, and it should be the next closest node
1477 * according to the distance array (which contains arbitrary distance values
1478 * from each node to each node in the system), and should also prefer nodes
1479 * with no CPUs, since presumably they'll have very little allocation pressure
1480 * on them otherwise.
1481 * It returns -1 if no node is found.
1483 static int __init
find_next_best_node(int node
, nodemask_t
*used_node_mask
)
1486 int min_val
= INT_MAX
;
1489 for_each_online_node(i
) {
1492 /* Start from local node */
1493 n
= (node
+i
) % num_online_nodes();
1495 /* Don't want a node to appear more than once */
1496 if (node_isset(n
, *used_node_mask
))
1499 /* Use the local node if we haven't already */
1500 if (!node_isset(node
, *used_node_mask
)) {
1505 /* Use the distance array to find the distance */
1506 val
= node_distance(node
, n
);
1508 /* Give preference to headless and unused nodes */
1509 tmp
= node_to_cpumask(n
);
1510 if (!cpus_empty(tmp
))
1511 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
1513 /* Slight preference for less loaded node */
1514 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
1515 val
+= node_load
[n
];
1517 if (val
< min_val
) {
1524 node_set(best_node
, *used_node_mask
);
1529 static void __init
build_zonelists(pg_data_t
*pgdat
)
1531 int i
, j
, k
, node
, local_node
;
1532 int prev_node
, load
;
1533 struct zonelist
*zonelist
;
1534 nodemask_t used_mask
;
1536 /* initialize zonelists */
1537 for (i
= 0; i
< GFP_ZONETYPES
; i
++) {
1538 zonelist
= pgdat
->node_zonelists
+ i
;
1539 zonelist
->zones
[0] = NULL
;
1542 /* NUMA-aware ordering of nodes */
1543 local_node
= pgdat
->node_id
;
1544 load
= num_online_nodes();
1545 prev_node
= local_node
;
1546 nodes_clear(used_mask
);
1547 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
1549 * We don't want to pressure a particular node.
1550 * So adding penalty to the first node in same
1551 * distance group to make it round-robin.
1553 if (node_distance(local_node
, node
) !=
1554 node_distance(local_node
, prev_node
))
1555 node_load
[node
] += load
;
1558 for (i
= 0; i
< GFP_ZONETYPES
; i
++) {
1559 zonelist
= pgdat
->node_zonelists
+ i
;
1560 for (j
= 0; zonelist
->zones
[j
] != NULL
; j
++);
1562 k
= highest_zone(i
);
1564 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
, k
);
1565 zonelist
->zones
[j
] = NULL
;
1570 #else /* CONFIG_NUMA */
1572 static void __init
build_zonelists(pg_data_t
*pgdat
)
1574 int i
, j
, k
, node
, local_node
;
1576 local_node
= pgdat
->node_id
;
1577 for (i
= 0; i
< GFP_ZONETYPES
; i
++) {
1578 struct zonelist
*zonelist
;
1580 zonelist
= pgdat
->node_zonelists
+ i
;
1583 k
= highest_zone(i
);
1584 j
= build_zonelists_node(pgdat
, zonelist
, j
, k
);
1586 * Now we build the zonelist so that it contains the zones
1587 * of all the other nodes.
1588 * We don't want to pressure a particular node, so when
1589 * building the zones for node N, we make sure that the
1590 * zones coming right after the local ones are those from
1591 * node N+1 (modulo N)
1593 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
1594 if (!node_online(node
))
1596 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
, k
);
1598 for (node
= 0; node
< local_node
; node
++) {
1599 if (!node_online(node
))
1601 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
, k
);
1604 zonelist
->zones
[j
] = NULL
;
1608 #endif /* CONFIG_NUMA */
1610 void __init
build_all_zonelists(void)
1614 for_each_online_node(i
)
1615 build_zonelists(NODE_DATA(i
));
1616 printk("Built %i zonelists\n", num_online_nodes());
1617 cpuset_init_current_mems_allowed();
1621 * Helper functions to size the waitqueue hash table.
1622 * Essentially these want to choose hash table sizes sufficiently
1623 * large so that collisions trying to wait on pages are rare.
1624 * But in fact, the number of active page waitqueues on typical
1625 * systems is ridiculously low, less than 200. So this is even
1626 * conservative, even though it seems large.
1628 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
1629 * waitqueues, i.e. the size of the waitq table given the number of pages.
1631 #define PAGES_PER_WAITQUEUE 256
1633 static inline unsigned long wait_table_size(unsigned long pages
)
1635 unsigned long size
= 1;
1637 pages
/= PAGES_PER_WAITQUEUE
;
1639 while (size
< pages
)
1643 * Once we have dozens or even hundreds of threads sleeping
1644 * on IO we've got bigger problems than wait queue collision.
1645 * Limit the size of the wait table to a reasonable size.
1647 size
= min(size
, 4096UL);
1649 return max(size
, 4UL);
1653 * This is an integer logarithm so that shifts can be used later
1654 * to extract the more random high bits from the multiplicative
1655 * hash function before the remainder is taken.
1657 static inline unsigned long wait_table_bits(unsigned long size
)
1662 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
1664 static void __init
calculate_zone_totalpages(struct pglist_data
*pgdat
,
1665 unsigned long *zones_size
, unsigned long *zholes_size
)
1667 unsigned long realtotalpages
, totalpages
= 0;
1670 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
1671 totalpages
+= zones_size
[i
];
1672 pgdat
->node_spanned_pages
= totalpages
;
1674 realtotalpages
= totalpages
;
1676 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
1677 realtotalpages
-= zholes_size
[i
];
1678 pgdat
->node_present_pages
= realtotalpages
;
1679 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
, realtotalpages
);
1684 * Initially all pages are reserved - free ones are freed
1685 * up by free_all_bootmem() once the early boot process is
1686 * done. Non-atomic initialization, single-pass.
1688 void __devinit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
1689 unsigned long start_pfn
)
1692 unsigned long end_pfn
= start_pfn
+ size
;
1695 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++, page
++) {
1696 if (!early_pfn_valid(pfn
))
1698 page
= pfn_to_page(pfn
);
1699 set_page_links(page
, zone
, nid
, pfn
);
1700 set_page_count(page
, 1);
1701 reset_page_mapcount(page
);
1702 SetPageReserved(page
);
1703 INIT_LIST_HEAD(&page
->lru
);
1704 #ifdef WANT_PAGE_VIRTUAL
1705 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
1706 if (!is_highmem_idx(zone
))
1707 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
1712 void zone_init_free_lists(struct pglist_data
*pgdat
, struct zone
*zone
,
1716 for (order
= 0; order
< MAX_ORDER
; order
++) {
1717 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
);
1718 zone
->free_area
[order
].nr_free
= 0;
1722 #define ZONETABLE_INDEX(x, zone_nr) ((x << ZONES_SHIFT) | zone_nr)
1723 void zonetable_add(struct zone
*zone
, int nid
, int zid
, unsigned long pfn
,
1726 unsigned long snum
= pfn_to_section_nr(pfn
);
1727 unsigned long end
= pfn_to_section_nr(pfn
+ size
);
1730 zone_table
[ZONETABLE_INDEX(nid
, zid
)] = zone
;
1732 for (; snum
<= end
; snum
++)
1733 zone_table
[ZONETABLE_INDEX(snum
, zid
)] = zone
;
1736 #ifndef __HAVE_ARCH_MEMMAP_INIT
1737 #define memmap_init(size, nid, zone, start_pfn) \
1738 memmap_init_zone((size), (nid), (zone), (start_pfn))
1741 static int __devinit
zone_batchsize(struct zone
*zone
)
1746 * The per-cpu-pages pools are set to around 1000th of the
1747 * size of the zone. But no more than 1/2 of a meg.
1749 * OK, so we don't know how big the cache is. So guess.
1751 batch
= zone
->present_pages
/ 1024;
1752 if (batch
* PAGE_SIZE
> 512 * 1024)
1753 batch
= (512 * 1024) / PAGE_SIZE
;
1754 batch
/= 4; /* We effectively *= 4 below */
1759 * Clamp the batch to a 2^n - 1 value. Having a power
1760 * of 2 value was found to be more likely to have
1761 * suboptimal cache aliasing properties in some cases.
1763 * For example if 2 tasks are alternately allocating
1764 * batches of pages, one task can end up with a lot
1765 * of pages of one half of the possible page colors
1766 * and the other with pages of the other colors.
1768 batch
= (1 << (fls(batch
+ batch
/2)-1)) - 1;
1773 inline void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
1775 struct per_cpu_pages
*pcp
;
1777 memset(p
, 0, sizeof(*p
));
1779 pcp
= &p
->pcp
[0]; /* hot */
1782 pcp
->high
= 6 * batch
;
1783 pcp
->batch
= max(1UL, 1 * batch
);
1784 INIT_LIST_HEAD(&pcp
->list
);
1786 pcp
= &p
->pcp
[1]; /* cold*/
1789 pcp
->high
= 2 * batch
;
1790 pcp
->batch
= max(1UL, batch
/2);
1791 INIT_LIST_HEAD(&pcp
->list
);
1796 * Boot pageset table. One per cpu which is going to be used for all
1797 * zones and all nodes. The parameters will be set in such a way
1798 * that an item put on a list will immediately be handed over to
1799 * the buddy list. This is safe since pageset manipulation is done
1800 * with interrupts disabled.
1802 * Some NUMA counter updates may also be caught by the boot pagesets.
1804 * The boot_pagesets must be kept even after bootup is complete for
1805 * unused processors and/or zones. They do play a role for bootstrapping
1806 * hotplugged processors.
1808 * zoneinfo_show() and maybe other functions do
1809 * not check if the processor is online before following the pageset pointer.
1810 * Other parts of the kernel may not check if the zone is available.
1812 static struct per_cpu_pageset
1813 boot_pageset
[NR_CPUS
];
1816 * Dynamically allocate memory for the
1817 * per cpu pageset array in struct zone.
1819 static int __devinit
process_zones(int cpu
)
1821 struct zone
*zone
, *dzone
;
1823 for_each_zone(zone
) {
1825 zone
->pageset
[cpu
] = kmalloc_node(sizeof(struct per_cpu_pageset
),
1826 GFP_KERNEL
, cpu_to_node(cpu
));
1827 if (!zone
->pageset
[cpu
])
1830 setup_pageset(zone
->pageset
[cpu
], zone_batchsize(zone
));
1835 for_each_zone(dzone
) {
1838 kfree(dzone
->pageset
[cpu
]);
1839 dzone
->pageset
[cpu
] = NULL
;
1844 static inline void free_zone_pagesets(int cpu
)
1849 for_each_zone(zone
) {
1850 struct per_cpu_pageset
*pset
= zone_pcp(zone
, cpu
);
1852 zone_pcp(zone
, cpu
) = NULL
;
1858 static int __devinit
pageset_cpuup_callback(struct notifier_block
*nfb
,
1859 unsigned long action
,
1862 int cpu
= (long)hcpu
;
1863 int ret
= NOTIFY_OK
;
1866 case CPU_UP_PREPARE
:
1867 if (process_zones(cpu
))
1870 case CPU_UP_CANCELED
:
1872 free_zone_pagesets(cpu
);
1880 static struct notifier_block pageset_notifier
=
1881 { &pageset_cpuup_callback
, NULL
, 0 };
1883 void __init
setup_per_cpu_pageset(void)
1887 /* Initialize per_cpu_pageset for cpu 0.
1888 * A cpuup callback will do this for every cpu
1889 * as it comes online
1891 err
= process_zones(smp_processor_id());
1893 register_cpu_notifier(&pageset_notifier
);
1899 void zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
1902 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
1905 * The per-page waitqueue mechanism uses hashed waitqueues
1908 zone
->wait_table_size
= wait_table_size(zone_size_pages
);
1909 zone
->wait_table_bits
= wait_table_bits(zone
->wait_table_size
);
1910 zone
->wait_table
= (wait_queue_head_t
*)
1911 alloc_bootmem_node(pgdat
, zone
->wait_table_size
1912 * sizeof(wait_queue_head_t
));
1914 for(i
= 0; i
< zone
->wait_table_size
; ++i
)
1915 init_waitqueue_head(zone
->wait_table
+ i
);
1918 static __devinit
void zone_pcp_init(struct zone
*zone
)
1921 unsigned long batch
= zone_batchsize(zone
);
1923 for (cpu
= 0; cpu
< NR_CPUS
; cpu
++) {
1925 /* Early boot. Slab allocator not functional yet */
1926 zone
->pageset
[cpu
] = &boot_pageset
[cpu
];
1927 setup_pageset(&boot_pageset
[cpu
],0);
1929 setup_pageset(zone_pcp(zone
,cpu
), batch
);
1932 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%lu\n",
1933 zone
->name
, zone
->present_pages
, batch
);
1936 static __devinit
void init_currently_empty_zone(struct zone
*zone
,
1937 unsigned long zone_start_pfn
, unsigned long size
)
1939 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
1941 zone_wait_table_init(zone
, size
);
1942 pgdat
->nr_zones
= zone_idx(zone
) + 1;
1944 zone
->zone_mem_map
= pfn_to_page(zone_start_pfn
);
1945 zone
->zone_start_pfn
= zone_start_pfn
;
1947 memmap_init(size
, pgdat
->node_id
, zone_idx(zone
), zone_start_pfn
);
1949 zone_init_free_lists(pgdat
, zone
, zone
->spanned_pages
);
1953 * Set up the zone data structures:
1954 * - mark all pages reserved
1955 * - mark all memory queues empty
1956 * - clear the memory bitmaps
1958 static void __init
free_area_init_core(struct pglist_data
*pgdat
,
1959 unsigned long *zones_size
, unsigned long *zholes_size
)
1962 int nid
= pgdat
->node_id
;
1963 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
1965 pgdat_resize_init(pgdat
);
1966 pgdat
->nr_zones
= 0;
1967 init_waitqueue_head(&pgdat
->kswapd_wait
);
1968 pgdat
->kswapd_max_order
= 0;
1970 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
1971 struct zone
*zone
= pgdat
->node_zones
+ j
;
1972 unsigned long size
, realsize
;
1974 realsize
= size
= zones_size
[j
];
1976 realsize
-= zholes_size
[j
];
1978 if (j
< ZONE_HIGHMEM
)
1979 nr_kernel_pages
+= realsize
;
1980 nr_all_pages
+= realsize
;
1982 zone
->spanned_pages
= size
;
1983 zone
->present_pages
= realsize
;
1984 zone
->name
= zone_names
[j
];
1985 spin_lock_init(&zone
->lock
);
1986 spin_lock_init(&zone
->lru_lock
);
1987 zone_seqlock_init(zone
);
1988 zone
->zone_pgdat
= pgdat
;
1989 zone
->free_pages
= 0;
1991 zone
->temp_priority
= zone
->prev_priority
= DEF_PRIORITY
;
1993 zone_pcp_init(zone
);
1994 INIT_LIST_HEAD(&zone
->active_list
);
1995 INIT_LIST_HEAD(&zone
->inactive_list
);
1996 zone
->nr_scan_active
= 0;
1997 zone
->nr_scan_inactive
= 0;
1998 zone
->nr_active
= 0;
1999 zone
->nr_inactive
= 0;
2000 atomic_set(&zone
->reclaim_in_progress
, 0);
2004 zonetable_add(zone
, nid
, j
, zone_start_pfn
, size
);
2005 init_currently_empty_zone(zone
, zone_start_pfn
, size
);
2006 zone_start_pfn
+= size
;
2010 static void __init
alloc_node_mem_map(struct pglist_data
*pgdat
)
2012 /* Skip empty nodes */
2013 if (!pgdat
->node_spanned_pages
)
2016 #ifdef CONFIG_FLAT_NODE_MEM_MAP
2017 /* ia64 gets its own node_mem_map, before this, without bootmem */
2018 if (!pgdat
->node_mem_map
) {
2022 size
= (pgdat
->node_spanned_pages
+ 1) * sizeof(struct page
);
2023 map
= alloc_remap(pgdat
->node_id
, size
);
2025 map
= alloc_bootmem_node(pgdat
, size
);
2026 pgdat
->node_mem_map
= map
;
2028 #ifdef CONFIG_FLATMEM
2030 * With no DISCONTIG, the global mem_map is just set as node 0's
2032 if (pgdat
== NODE_DATA(0))
2033 mem_map
= NODE_DATA(0)->node_mem_map
;
2035 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
2038 void __init
free_area_init_node(int nid
, struct pglist_data
*pgdat
,
2039 unsigned long *zones_size
, unsigned long node_start_pfn
,
2040 unsigned long *zholes_size
)
2042 pgdat
->node_id
= nid
;
2043 pgdat
->node_start_pfn
= node_start_pfn
;
2044 calculate_zone_totalpages(pgdat
, zones_size
, zholes_size
);
2046 alloc_node_mem_map(pgdat
);
2048 free_area_init_core(pgdat
, zones_size
, zholes_size
);
2051 #ifndef CONFIG_NEED_MULTIPLE_NODES
2052 static bootmem_data_t contig_bootmem_data
;
2053 struct pglist_data contig_page_data
= { .bdata
= &contig_bootmem_data
};
2055 EXPORT_SYMBOL(contig_page_data
);
2058 void __init
free_area_init(unsigned long *zones_size
)
2060 free_area_init_node(0, NODE_DATA(0), zones_size
,
2061 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
2064 #ifdef CONFIG_PROC_FS
2066 #include <linux/seq_file.h>
2068 static void *frag_start(struct seq_file
*m
, loff_t
*pos
)
2073 for (pgdat
= pgdat_list
; pgdat
&& node
; pgdat
= pgdat
->pgdat_next
)
2079 static void *frag_next(struct seq_file
*m
, void *arg
, loff_t
*pos
)
2081 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
2084 return pgdat
->pgdat_next
;
2087 static void frag_stop(struct seq_file
*m
, void *arg
)
2092 * This walks the free areas for each zone.
2094 static int frag_show(struct seq_file
*m
, void *arg
)
2096 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
2098 struct zone
*node_zones
= pgdat
->node_zones
;
2099 unsigned long flags
;
2102 for (zone
= node_zones
; zone
- node_zones
< MAX_NR_ZONES
; ++zone
) {
2103 if (!zone
->present_pages
)
2106 spin_lock_irqsave(&zone
->lock
, flags
);
2107 seq_printf(m
, "Node %d, zone %8s ", pgdat
->node_id
, zone
->name
);
2108 for (order
= 0; order
< MAX_ORDER
; ++order
)
2109 seq_printf(m
, "%6lu ", zone
->free_area
[order
].nr_free
);
2110 spin_unlock_irqrestore(&zone
->lock
, flags
);
2116 struct seq_operations fragmentation_op
= {
2117 .start
= frag_start
,
2124 * Output information about zones in @pgdat.
2126 static int zoneinfo_show(struct seq_file
*m
, void *arg
)
2128 pg_data_t
*pgdat
= arg
;
2130 struct zone
*node_zones
= pgdat
->node_zones
;
2131 unsigned long flags
;
2133 for (zone
= node_zones
; zone
- node_zones
< MAX_NR_ZONES
; zone
++) {
2136 if (!zone
->present_pages
)
2139 spin_lock_irqsave(&zone
->lock
, flags
);
2140 seq_printf(m
, "Node %d, zone %8s", pgdat
->node_id
, zone
->name
);
2148 "\n scanned %lu (a: %lu i: %lu)"
2157 zone
->pages_scanned
,
2158 zone
->nr_scan_active
, zone
->nr_scan_inactive
,
2159 zone
->spanned_pages
,
2160 zone
->present_pages
);
2162 "\n protection: (%lu",
2163 zone
->lowmem_reserve
[0]);
2164 for (i
= 1; i
< ARRAY_SIZE(zone
->lowmem_reserve
); i
++)
2165 seq_printf(m
, ", %lu", zone
->lowmem_reserve
[i
]);
2169 for (i
= 0; i
< ARRAY_SIZE(zone
->pageset
); i
++) {
2170 struct per_cpu_pageset
*pageset
;
2173 pageset
= zone_pcp(zone
, i
);
2174 for (j
= 0; j
< ARRAY_SIZE(pageset
->pcp
); j
++) {
2175 if (pageset
->pcp
[j
].count
)
2178 if (j
== ARRAY_SIZE(pageset
->pcp
))
2180 for (j
= 0; j
< ARRAY_SIZE(pageset
->pcp
); j
++) {
2182 "\n cpu: %i pcp: %i"
2188 pageset
->pcp
[j
].count
,
2189 pageset
->pcp
[j
].low
,
2190 pageset
->pcp
[j
].high
,
2191 pageset
->pcp
[j
].batch
);
2197 "\n numa_foreign: %lu"
2198 "\n interleave_hit: %lu"
2199 "\n local_node: %lu"
2200 "\n other_node: %lu",
2203 pageset
->numa_foreign
,
2204 pageset
->interleave_hit
,
2205 pageset
->local_node
,
2206 pageset
->other_node
);
2210 "\n all_unreclaimable: %u"
2211 "\n prev_priority: %i"
2212 "\n temp_priority: %i"
2213 "\n start_pfn: %lu",
2214 zone
->all_unreclaimable
,
2215 zone
->prev_priority
,
2216 zone
->temp_priority
,
2217 zone
->zone_start_pfn
);
2218 spin_unlock_irqrestore(&zone
->lock
, flags
);
2224 struct seq_operations zoneinfo_op
= {
2225 .start
= frag_start
, /* iterate over all zones. The same as in
2229 .show
= zoneinfo_show
,
2232 static char *vmstat_text
[] = {
2236 "nr_page_table_pages",
2261 "pgscan_kswapd_high",
2262 "pgscan_kswapd_normal",
2264 "pgscan_kswapd_dma",
2265 "pgscan_direct_high",
2266 "pgscan_direct_normal",
2267 "pgscan_direct_dma",
2272 "kswapd_inodesteal",
2280 static void *vmstat_start(struct seq_file
*m
, loff_t
*pos
)
2282 struct page_state
*ps
;
2284 if (*pos
>= ARRAY_SIZE(vmstat_text
))
2287 ps
= kmalloc(sizeof(*ps
), GFP_KERNEL
);
2290 return ERR_PTR(-ENOMEM
);
2291 get_full_page_state(ps
);
2292 ps
->pgpgin
/= 2; /* sectors -> kbytes */
2294 return (unsigned long *)ps
+ *pos
;
2297 static void *vmstat_next(struct seq_file
*m
, void *arg
, loff_t
*pos
)
2300 if (*pos
>= ARRAY_SIZE(vmstat_text
))
2302 return (unsigned long *)m
->private + *pos
;
2305 static int vmstat_show(struct seq_file
*m
, void *arg
)
2307 unsigned long *l
= arg
;
2308 unsigned long off
= l
- (unsigned long *)m
->private;
2310 seq_printf(m
, "%s %lu\n", vmstat_text
[off
], *l
);
2314 static void vmstat_stop(struct seq_file
*m
, void *arg
)
2320 struct seq_operations vmstat_op
= {
2321 .start
= vmstat_start
,
2322 .next
= vmstat_next
,
2323 .stop
= vmstat_stop
,
2324 .show
= vmstat_show
,
2327 #endif /* CONFIG_PROC_FS */
2329 #ifdef CONFIG_HOTPLUG_CPU
2330 static int page_alloc_cpu_notify(struct notifier_block
*self
,
2331 unsigned long action
, void *hcpu
)
2333 int cpu
= (unsigned long)hcpu
;
2335 unsigned long *src
, *dest
;
2337 if (action
== CPU_DEAD
) {
2340 /* Drain local pagecache count. */
2341 count
= &per_cpu(nr_pagecache_local
, cpu
);
2342 atomic_add(*count
, &nr_pagecache
);
2344 local_irq_disable();
2347 /* Add dead cpu's page_states to our own. */
2348 dest
= (unsigned long *)&__get_cpu_var(page_states
);
2349 src
= (unsigned long *)&per_cpu(page_states
, cpu
);
2351 for (i
= 0; i
< sizeof(struct page_state
)/sizeof(unsigned long);
2361 #endif /* CONFIG_HOTPLUG_CPU */
2363 void __init
page_alloc_init(void)
2365 hotcpu_notifier(page_alloc_cpu_notify
, 0);
2369 * setup_per_zone_lowmem_reserve - called whenever
2370 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
2371 * has a correct pages reserved value, so an adequate number of
2372 * pages are left in the zone after a successful __alloc_pages().
2374 static void setup_per_zone_lowmem_reserve(void)
2376 struct pglist_data
*pgdat
;
2379 for_each_pgdat(pgdat
) {
2380 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
2381 struct zone
*zone
= pgdat
->node_zones
+ j
;
2382 unsigned long present_pages
= zone
->present_pages
;
2384 zone
->lowmem_reserve
[j
] = 0;
2386 for (idx
= j
-1; idx
>= 0; idx
--) {
2387 struct zone
*lower_zone
;
2389 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
2390 sysctl_lowmem_reserve_ratio
[idx
] = 1;
2392 lower_zone
= pgdat
->node_zones
+ idx
;
2393 lower_zone
->lowmem_reserve
[j
] = present_pages
/
2394 sysctl_lowmem_reserve_ratio
[idx
];
2395 present_pages
+= lower_zone
->present_pages
;
2402 * setup_per_zone_pages_min - called when min_free_kbytes changes. Ensures
2403 * that the pages_{min,low,high} values for each zone are set correctly
2404 * with respect to min_free_kbytes.
2406 void setup_per_zone_pages_min(void)
2408 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
2409 unsigned long lowmem_pages
= 0;
2411 unsigned long flags
;
2413 /* Calculate total number of !ZONE_HIGHMEM pages */
2414 for_each_zone(zone
) {
2415 if (!is_highmem(zone
))
2416 lowmem_pages
+= zone
->present_pages
;
2419 for_each_zone(zone
) {
2421 spin_lock_irqsave(&zone
->lru_lock
, flags
);
2422 tmp
= (pages_min
* zone
->present_pages
) / lowmem_pages
;
2423 if (is_highmem(zone
)) {
2425 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
2426 * need highmem pages, so cap pages_min to a small
2429 * The (pages_high-pages_low) and (pages_low-pages_min)
2430 * deltas controls asynch page reclaim, and so should
2431 * not be capped for highmem.
2435 min_pages
= zone
->present_pages
/ 1024;
2436 if (min_pages
< SWAP_CLUSTER_MAX
)
2437 min_pages
= SWAP_CLUSTER_MAX
;
2438 if (min_pages
> 128)
2440 zone
->pages_min
= min_pages
;
2443 * If it's a lowmem zone, reserve a number of pages
2444 * proportionate to the zone's size.
2446 zone
->pages_min
= tmp
;
2449 zone
->pages_low
= zone
->pages_min
+ tmp
/ 4;
2450 zone
->pages_high
= zone
->pages_min
+ tmp
/ 2;
2451 spin_unlock_irqrestore(&zone
->lru_lock
, flags
);
2456 * Initialise min_free_kbytes.
2458 * For small machines we want it small (128k min). For large machines
2459 * we want it large (64MB max). But it is not linear, because network
2460 * bandwidth does not increase linearly with machine size. We use
2462 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
2463 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
2479 static int __init
init_per_zone_pages_min(void)
2481 unsigned long lowmem_kbytes
;
2483 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
2485 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
2486 if (min_free_kbytes
< 128)
2487 min_free_kbytes
= 128;
2488 if (min_free_kbytes
> 65536)
2489 min_free_kbytes
= 65536;
2490 setup_per_zone_pages_min();
2491 setup_per_zone_lowmem_reserve();
2494 module_init(init_per_zone_pages_min
)
2497 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
2498 * that we can call two helper functions whenever min_free_kbytes
2501 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
2502 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
2504 proc_dointvec(table
, write
, file
, buffer
, length
, ppos
);
2505 setup_per_zone_pages_min();
2510 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
2511 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
2512 * whenever sysctl_lowmem_reserve_ratio changes.
2514 * The reserve ratio obviously has absolutely no relation with the
2515 * pages_min watermarks. The lowmem reserve ratio can only make sense
2516 * if in function of the boot time zone sizes.
2518 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
2519 struct file
*file
, void __user
*buffer
, size_t *length
, loff_t
*ppos
)
2521 proc_dointvec_minmax(table
, write
, file
, buffer
, length
, ppos
);
2522 setup_per_zone_lowmem_reserve();
2526 __initdata
int hashdist
= HASHDIST_DEFAULT
;
2529 static int __init
set_hashdist(char *str
)
2533 hashdist
= simple_strtoul(str
, &str
, 0);
2536 __setup("hashdist=", set_hashdist
);
2540 * allocate a large system hash table from bootmem
2541 * - it is assumed that the hash table must contain an exact power-of-2
2542 * quantity of entries
2543 * - limit is the number of hash buckets, not the total allocation size
2545 void *__init
alloc_large_system_hash(const char *tablename
,
2546 unsigned long bucketsize
,
2547 unsigned long numentries
,
2550 unsigned int *_hash_shift
,
2551 unsigned int *_hash_mask
,
2552 unsigned long limit
)
2554 unsigned long long max
= limit
;
2555 unsigned long log2qty
, size
;
2558 /* allow the kernel cmdline to have a say */
2560 /* round applicable memory size up to nearest megabyte */
2561 numentries
= (flags
& HASH_HIGHMEM
) ? nr_all_pages
: nr_kernel_pages
;
2562 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
2563 numentries
>>= 20 - PAGE_SHIFT
;
2564 numentries
<<= 20 - PAGE_SHIFT
;
2566 /* limit to 1 bucket per 2^scale bytes of low memory */
2567 if (scale
> PAGE_SHIFT
)
2568 numentries
>>= (scale
- PAGE_SHIFT
);
2570 numentries
<<= (PAGE_SHIFT
- scale
);
2572 /* rounded up to nearest power of 2 in size */
2573 numentries
= 1UL << (long_log2(numentries
) + 1);
2575 /* limit allocation size to 1/16 total memory by default */
2577 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
2578 do_div(max
, bucketsize
);
2581 if (numentries
> max
)
2584 log2qty
= long_log2(numentries
);
2587 size
= bucketsize
<< log2qty
;
2588 if (flags
& HASH_EARLY
)
2589 table
= alloc_bootmem(size
);
2591 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
2593 unsigned long order
;
2594 for (order
= 0; ((1UL << order
) << PAGE_SHIFT
) < size
; order
++)
2596 table
= (void*) __get_free_pages(GFP_ATOMIC
, order
);
2598 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
2601 panic("Failed to allocate %s hash table\n", tablename
);
2603 printk("%s hash table entries: %d (order: %d, %lu bytes)\n",
2606 long_log2(size
) - PAGE_SHIFT
,
2610 *_hash_shift
= log2qty
;
2612 *_hash_mask
= (1 << log2qty
) - 1;