2 * linux/mm/page_alloc.c
4 * Manages the free list, the system allocates free pages here.
5 * Note that kmalloc() lives in slab.c
7 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
8 * Swap reorganised 29.12.95, Stephen Tweedie
9 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
10 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
11 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
12 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000
13 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
14 * (lots of bits borrowed from Ingo Molnar & Andrew Morton)
17 #include <linux/stddef.h>
19 #include <linux/swap.h>
20 #include <linux/interrupt.h>
21 #include <linux/pagemap.h>
22 #include <linux/jiffies.h>
23 #include <linux/bootmem.h>
24 #include <linux/memblock.h>
25 #include <linux/compiler.h>
26 #include <linux/kernel.h>
27 #include <linux/kmemcheck.h>
28 #include <linux/module.h>
29 #include <linux/suspend.h>
30 #include <linux/pagevec.h>
31 #include <linux/blkdev.h>
32 #include <linux/slab.h>
33 #include <linux/oom.h>
34 #include <linux/notifier.h>
35 #include <linux/topology.h>
36 #include <linux/sysctl.h>
37 #include <linux/cpu.h>
38 #include <linux/cpuset.h>
39 #include <linux/memory_hotplug.h>
40 #include <linux/nodemask.h>
41 #include <linux/vmalloc.h>
42 #include <linux/mempolicy.h>
43 #include <linux/stop_machine.h>
44 #include <linux/sort.h>
45 #include <linux/pfn.h>
46 #include <linux/backing-dev.h>
47 #include <linux/fault-inject.h>
48 #include <linux/page-isolation.h>
49 #include <linux/page_cgroup.h>
50 #include <linux/debugobjects.h>
51 #include <linux/kmemleak.h>
52 #include <linux/memory.h>
53 #include <linux/compaction.h>
54 #include <trace/events/kmem.h>
55 #include <linux/ftrace_event.h>
57 #include <asm/tlbflush.h>
58 #include <asm/div64.h>
61 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
62 DEFINE_PER_CPU(int, numa_node
);
63 EXPORT_PER_CPU_SYMBOL(numa_node
);
66 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
68 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
69 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
70 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
71 * defined in <linux/topology.h>.
73 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
74 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
78 * Array of node states.
80 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
81 [N_POSSIBLE
] = NODE_MASK_ALL
,
82 [N_ONLINE
] = { { [0] = 1UL } },
84 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
86 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
88 [N_CPU
] = { { [0] = 1UL } },
91 EXPORT_SYMBOL(node_states
);
93 unsigned long totalram_pages __read_mostly
;
94 unsigned long totalreserve_pages __read_mostly
;
95 int percpu_pagelist_fraction
;
96 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
98 #ifdef CONFIG_PM_SLEEP
100 * The following functions are used by the suspend/hibernate code to temporarily
101 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
102 * while devices are suspended. To avoid races with the suspend/hibernate code,
103 * they should always be called with pm_mutex held (gfp_allowed_mask also should
104 * only be modified with pm_mutex held, unless the suspend/hibernate code is
105 * guaranteed not to run in parallel with that modification).
108 static gfp_t saved_gfp_mask
;
110 void pm_restore_gfp_mask(void)
112 WARN_ON(!mutex_is_locked(&pm_mutex
));
113 if (saved_gfp_mask
) {
114 gfp_allowed_mask
= saved_gfp_mask
;
119 void pm_restrict_gfp_mask(void)
121 WARN_ON(!mutex_is_locked(&pm_mutex
));
122 WARN_ON(saved_gfp_mask
);
123 saved_gfp_mask
= gfp_allowed_mask
;
124 gfp_allowed_mask
&= ~GFP_IOFS
;
126 #endif /* CONFIG_PM_SLEEP */
128 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
129 int pageblock_order __read_mostly
;
132 static void __free_pages_ok(struct page
*page
, unsigned int order
);
135 * results with 256, 32 in the lowmem_reserve sysctl:
136 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
137 * 1G machine -> (16M dma, 784M normal, 224M high)
138 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
139 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
140 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
142 * TBD: should special case ZONE_DMA32 machines here - in those we normally
143 * don't need any ZONE_NORMAL reservation
145 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
146 #ifdef CONFIG_ZONE_DMA
149 #ifdef CONFIG_ZONE_DMA32
152 #ifdef CONFIG_HIGHMEM
158 EXPORT_SYMBOL(totalram_pages
);
160 static char * const zone_names
[MAX_NR_ZONES
] = {
161 #ifdef CONFIG_ZONE_DMA
164 #ifdef CONFIG_ZONE_DMA32
168 #ifdef CONFIG_HIGHMEM
174 int min_free_kbytes
= 1024;
176 static unsigned long __meminitdata nr_kernel_pages
;
177 static unsigned long __meminitdata nr_all_pages
;
178 static unsigned long __meminitdata dma_reserve
;
180 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
182 * MAX_ACTIVE_REGIONS determines the maximum number of distinct
183 * ranges of memory (RAM) that may be registered with add_active_range().
184 * Ranges passed to add_active_range() will be merged if possible
185 * so the number of times add_active_range() can be called is
186 * related to the number of nodes and the number of holes
188 #ifdef CONFIG_MAX_ACTIVE_REGIONS
189 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */
190 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
192 #if MAX_NUMNODES >= 32
193 /* If there can be many nodes, allow up to 50 holes per node */
194 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
196 /* By default, allow up to 256 distinct regions */
197 #define MAX_ACTIVE_REGIONS 256
201 static struct node_active_region __meminitdata early_node_map
[MAX_ACTIVE_REGIONS
];
202 static int __meminitdata nr_nodemap_entries
;
203 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
204 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
205 static unsigned long __initdata required_kernelcore
;
206 static unsigned long __initdata required_movablecore
;
207 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
209 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
211 EXPORT_SYMBOL(movable_zone
);
212 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
215 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
216 int nr_online_nodes __read_mostly
= 1;
217 EXPORT_SYMBOL(nr_node_ids
);
218 EXPORT_SYMBOL(nr_online_nodes
);
221 int page_group_by_mobility_disabled __read_mostly
;
223 static void set_pageblock_migratetype(struct page
*page
, int migratetype
)
226 if (unlikely(page_group_by_mobility_disabled
))
227 migratetype
= MIGRATE_UNMOVABLE
;
229 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
230 PB_migrate
, PB_migrate_end
);
233 bool oom_killer_disabled __read_mostly
;
235 #ifdef CONFIG_DEBUG_VM
236 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
240 unsigned long pfn
= page_to_pfn(page
);
243 seq
= zone_span_seqbegin(zone
);
244 if (pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
246 else if (pfn
< zone
->zone_start_pfn
)
248 } while (zone_span_seqretry(zone
, seq
));
253 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
255 if (!pfn_valid_within(page_to_pfn(page
)))
257 if (zone
!= page_zone(page
))
263 * Temporary debugging check for pages not lying within a given zone.
265 static int bad_range(struct zone
*zone
, struct page
*page
)
267 if (page_outside_zone_boundaries(zone
, page
))
269 if (!page_is_consistent(zone
, page
))
275 static inline int bad_range(struct zone
*zone
, struct page
*page
)
281 static void bad_page(struct page
*page
)
283 static unsigned long resume
;
284 static unsigned long nr_shown
;
285 static unsigned long nr_unshown
;
287 /* Don't complain about poisoned pages */
288 if (PageHWPoison(page
)) {
289 __ClearPageBuddy(page
);
294 * Allow a burst of 60 reports, then keep quiet for that minute;
295 * or allow a steady drip of one report per second.
297 if (nr_shown
== 60) {
298 if (time_before(jiffies
, resume
)) {
304 "BUG: Bad page state: %lu messages suppressed\n",
311 resume
= jiffies
+ 60 * HZ
;
313 printk(KERN_ALERT
"BUG: Bad page state in process %s pfn:%05lx\n",
314 current
->comm
, page_to_pfn(page
));
319 /* Leave bad fields for debug, except PageBuddy could make trouble */
320 __ClearPageBuddy(page
);
321 add_taint(TAINT_BAD_PAGE
);
325 * Higher-order pages are called "compound pages". They are structured thusly:
327 * The first PAGE_SIZE page is called the "head page".
329 * The remaining PAGE_SIZE pages are called "tail pages".
331 * All pages have PG_compound set. All pages have their ->private pointing at
332 * the head page (even the head page has this).
334 * The first tail page's ->lru.next holds the address of the compound page's
335 * put_page() function. Its ->lru.prev holds the order of allocation.
336 * This usage means that zero-order pages may not be compound.
339 static void free_compound_page(struct page
*page
)
341 __free_pages_ok(page
, compound_order(page
));
344 void prep_compound_page(struct page
*page
, unsigned long order
)
347 int nr_pages
= 1 << order
;
349 set_compound_page_dtor(page
, free_compound_page
);
350 set_compound_order(page
, order
);
352 for (i
= 1; i
< nr_pages
; i
++) {
353 struct page
*p
= page
+ i
;
356 p
->first_page
= page
;
360 static int destroy_compound_page(struct page
*page
, unsigned long order
)
363 int nr_pages
= 1 << order
;
366 if (unlikely(compound_order(page
) != order
) ||
367 unlikely(!PageHead(page
))) {
372 __ClearPageHead(page
);
374 for (i
= 1; i
< nr_pages
; i
++) {
375 struct page
*p
= page
+ i
;
377 if (unlikely(!PageTail(p
) || (p
->first_page
!= page
))) {
387 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
392 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
393 * and __GFP_HIGHMEM from hard or soft interrupt context.
395 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
396 for (i
= 0; i
< (1 << order
); i
++)
397 clear_highpage(page
+ i
);
400 static inline void set_page_order(struct page
*page
, int order
)
402 set_page_private(page
, order
);
403 __SetPageBuddy(page
);
406 static inline void rmv_page_order(struct page
*page
)
408 __ClearPageBuddy(page
);
409 set_page_private(page
, 0);
413 * Locate the struct page for both the matching buddy in our
414 * pair (buddy1) and the combined O(n+1) page they form (page).
416 * 1) Any buddy B1 will have an order O twin B2 which satisfies
417 * the following equation:
419 * For example, if the starting buddy (buddy2) is #8 its order
421 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
423 * 2) Any buddy B will have an order O+1 parent P which
424 * satisfies the following equation:
427 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
429 static inline struct page
*
430 __page_find_buddy(struct page
*page
, unsigned long page_idx
, unsigned int order
)
432 unsigned long buddy_idx
= page_idx
^ (1 << order
);
434 return page
+ (buddy_idx
- page_idx
);
437 static inline unsigned long
438 __find_combined_index(unsigned long page_idx
, unsigned int order
)
440 return (page_idx
& ~(1 << order
));
444 * This function checks whether a page is free && is the buddy
445 * we can do coalesce a page and its buddy if
446 * (a) the buddy is not in a hole &&
447 * (b) the buddy is in the buddy system &&
448 * (c) a page and its buddy have the same order &&
449 * (d) a page and its buddy are in the same zone.
451 * For recording whether a page is in the buddy system, we use PG_buddy.
452 * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
454 * For recording page's order, we use page_private(page).
456 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
459 if (!pfn_valid_within(page_to_pfn(buddy
)))
462 if (page_zone_id(page
) != page_zone_id(buddy
))
465 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
466 VM_BUG_ON(page_count(buddy
) != 0);
473 * Freeing function for a buddy system allocator.
475 * The concept of a buddy system is to maintain direct-mapped table
476 * (containing bit values) for memory blocks of various "orders".
477 * The bottom level table contains the map for the smallest allocatable
478 * units of memory (here, pages), and each level above it describes
479 * pairs of units from the levels below, hence, "buddies".
480 * At a high level, all that happens here is marking the table entry
481 * at the bottom level available, and propagating the changes upward
482 * as necessary, plus some accounting needed to play nicely with other
483 * parts of the VM system.
484 * At each level, we keep a list of pages, which are heads of continuous
485 * free pages of length of (1 << order) and marked with PG_buddy. Page's
486 * order is recorded in page_private(page) field.
487 * So when we are allocating or freeing one, we can derive the state of the
488 * other. That is, if we allocate a small block, and both were
489 * free, the remainder of the region must be split into blocks.
490 * If a block is freed, and its buddy is also free, then this
491 * triggers coalescing into a block of larger size.
496 static inline void __free_one_page(struct page
*page
,
497 struct zone
*zone
, unsigned int order
,
500 unsigned long page_idx
;
501 unsigned long combined_idx
;
504 if (unlikely(PageCompound(page
)))
505 if (unlikely(destroy_compound_page(page
, order
)))
508 VM_BUG_ON(migratetype
== -1);
510 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
512 VM_BUG_ON(page_idx
& ((1 << order
) - 1));
513 VM_BUG_ON(bad_range(zone
, page
));
515 while (order
< MAX_ORDER
-1) {
516 buddy
= __page_find_buddy(page
, page_idx
, order
);
517 if (!page_is_buddy(page
, buddy
, order
))
520 /* Our buddy is free, merge with it and move up one order. */
521 list_del(&buddy
->lru
);
522 zone
->free_area
[order
].nr_free
--;
523 rmv_page_order(buddy
);
524 combined_idx
= __find_combined_index(page_idx
, order
);
525 page
= page
+ (combined_idx
- page_idx
);
526 page_idx
= combined_idx
;
529 set_page_order(page
, order
);
532 * If this is not the largest possible page, check if the buddy
533 * of the next-highest order is free. If it is, it's possible
534 * that pages are being freed that will coalesce soon. In case,
535 * that is happening, add the free page to the tail of the list
536 * so it's less likely to be used soon and more likely to be merged
537 * as a higher order page
539 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
540 struct page
*higher_page
, *higher_buddy
;
541 combined_idx
= __find_combined_index(page_idx
, order
);
542 higher_page
= page
+ combined_idx
- page_idx
;
543 higher_buddy
= __page_find_buddy(higher_page
, combined_idx
, order
+ 1);
544 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
545 list_add_tail(&page
->lru
,
546 &zone
->free_area
[order
].free_list
[migratetype
]);
551 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
553 zone
->free_area
[order
].nr_free
++;
557 * free_page_mlock() -- clean up attempts to free and mlocked() page.
558 * Page should not be on lru, so no need to fix that up.
559 * free_pages_check() will verify...
561 static inline void free_page_mlock(struct page
*page
)
563 __dec_zone_page_state(page
, NR_MLOCK
);
564 __count_vm_event(UNEVICTABLE_MLOCKFREED
);
567 static inline int free_pages_check(struct page
*page
)
569 if (unlikely(page_mapcount(page
) |
570 (page
->mapping
!= NULL
) |
571 (atomic_read(&page
->_count
) != 0) |
572 (page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
))) {
576 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
577 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
582 * Frees a number of pages from the PCP lists
583 * Assumes all pages on list are in same zone, and of same order.
584 * count is the number of pages to free.
586 * If the zone was previously in an "all pages pinned" state then look to
587 * see if this freeing clears that state.
589 * And clear the zone's pages_scanned counter, to hold off the "all pages are
590 * pinned" detection logic.
592 static void free_pcppages_bulk(struct zone
*zone
, int count
,
593 struct per_cpu_pages
*pcp
)
599 spin_lock(&zone
->lock
);
600 zone
->all_unreclaimable
= 0;
601 zone
->pages_scanned
= 0;
605 struct list_head
*list
;
608 * Remove pages from lists in a round-robin fashion. A
609 * batch_free count is maintained that is incremented when an
610 * empty list is encountered. This is so more pages are freed
611 * off fuller lists instead of spinning excessively around empty
616 if (++migratetype
== MIGRATE_PCPTYPES
)
618 list
= &pcp
->lists
[migratetype
];
619 } while (list_empty(list
));
622 page
= list_entry(list
->prev
, struct page
, lru
);
623 /* must delete as __free_one_page list manipulates */
624 list_del(&page
->lru
);
625 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
626 __free_one_page(page
, zone
, 0, page_private(page
));
627 trace_mm_page_pcpu_drain(page
, 0, page_private(page
));
628 } while (--to_free
&& --batch_free
&& !list_empty(list
));
630 __mod_zone_page_state(zone
, NR_FREE_PAGES
, count
);
631 spin_unlock(&zone
->lock
);
634 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
,
637 spin_lock(&zone
->lock
);
638 zone
->all_unreclaimable
= 0;
639 zone
->pages_scanned
= 0;
641 __free_one_page(page
, zone
, order
, migratetype
);
642 __mod_zone_page_state(zone
, NR_FREE_PAGES
, 1 << order
);
643 spin_unlock(&zone
->lock
);
646 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
651 trace_mm_page_free_direct(page
, order
);
652 kmemcheck_free_shadow(page
, order
);
654 for (i
= 0; i
< (1 << order
); i
++) {
655 struct page
*pg
= page
+ i
;
659 bad
+= free_pages_check(pg
);
664 if (!PageHighMem(page
)) {
665 debug_check_no_locks_freed(page_address(page
),PAGE_SIZE
<<order
);
666 debug_check_no_obj_freed(page_address(page
),
669 arch_free_page(page
, order
);
670 kernel_map_pages(page
, 1 << order
, 0);
675 static void __free_pages_ok(struct page
*page
, unsigned int order
)
678 int wasMlocked
= __TestClearPageMlocked(page
);
680 if (!free_pages_prepare(page
, order
))
683 local_irq_save(flags
);
684 if (unlikely(wasMlocked
))
685 free_page_mlock(page
);
686 __count_vm_events(PGFREE
, 1 << order
);
687 free_one_page(page_zone(page
), page
, order
,
688 get_pageblock_migratetype(page
));
689 local_irq_restore(flags
);
693 * permit the bootmem allocator to evade page validation on high-order frees
695 void __meminit
__free_pages_bootmem(struct page
*page
, unsigned int order
)
698 __ClearPageReserved(page
);
699 set_page_count(page
, 0);
700 set_page_refcounted(page
);
706 for (loop
= 0; loop
< BITS_PER_LONG
; loop
++) {
707 struct page
*p
= &page
[loop
];
709 if (loop
+ 1 < BITS_PER_LONG
)
711 __ClearPageReserved(p
);
712 set_page_count(p
, 0);
715 set_page_refcounted(page
);
716 __free_pages(page
, order
);
722 * The order of subdivision here is critical for the IO subsystem.
723 * Please do not alter this order without good reasons and regression
724 * testing. Specifically, as large blocks of memory are subdivided,
725 * the order in which smaller blocks are delivered depends on the order
726 * they're subdivided in this function. This is the primary factor
727 * influencing the order in which pages are delivered to the IO
728 * subsystem according to empirical testing, and this is also justified
729 * by considering the behavior of a buddy system containing a single
730 * large block of memory acted on by a series of small allocations.
731 * This behavior is a critical factor in sglist merging's success.
735 static inline void expand(struct zone
*zone
, struct page
*page
,
736 int low
, int high
, struct free_area
*area
,
739 unsigned long size
= 1 << high
;
745 VM_BUG_ON(bad_range(zone
, &page
[size
]));
746 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
748 set_page_order(&page
[size
], high
);
753 * This page is about to be returned from the page allocator
755 static inline int check_new_page(struct page
*page
)
757 if (unlikely(page_mapcount(page
) |
758 (page
->mapping
!= NULL
) |
759 (atomic_read(&page
->_count
) != 0) |
760 (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
))) {
767 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
771 for (i
= 0; i
< (1 << order
); i
++) {
772 struct page
*p
= page
+ i
;
773 if (unlikely(check_new_page(p
)))
777 set_page_private(page
, 0);
778 set_page_refcounted(page
);
780 arch_alloc_page(page
, order
);
781 kernel_map_pages(page
, 1 << order
, 1);
783 if (gfp_flags
& __GFP_ZERO
)
784 prep_zero_page(page
, order
, gfp_flags
);
786 if (order
&& (gfp_flags
& __GFP_COMP
))
787 prep_compound_page(page
, order
);
793 * Go through the free lists for the given migratetype and remove
794 * the smallest available page from the freelists
797 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
800 unsigned int current_order
;
801 struct free_area
* area
;
804 /* Find a page of the appropriate size in the preferred list */
805 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
806 area
= &(zone
->free_area
[current_order
]);
807 if (list_empty(&area
->free_list
[migratetype
]))
810 page
= list_entry(area
->free_list
[migratetype
].next
,
812 list_del(&page
->lru
);
813 rmv_page_order(page
);
815 expand(zone
, page
, order
, current_order
, area
, migratetype
);
824 * This array describes the order lists are fallen back to when
825 * the free lists for the desirable migrate type are depleted
827 static int fallbacks
[MIGRATE_TYPES
][MIGRATE_TYPES
-1] = {
828 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
829 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
830 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
831 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
, MIGRATE_RESERVE
, MIGRATE_RESERVE
}, /* Never used */
835 * Move the free pages in a range to the free lists of the requested type.
836 * Note that start_page and end_pages are not aligned on a pageblock
837 * boundary. If alignment is required, use move_freepages_block()
839 static int move_freepages(struct zone
*zone
,
840 struct page
*start_page
, struct page
*end_page
,
847 #ifndef CONFIG_HOLES_IN_ZONE
849 * page_zone is not safe to call in this context when
850 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
851 * anyway as we check zone boundaries in move_freepages_block().
852 * Remove at a later date when no bug reports exist related to
853 * grouping pages by mobility
855 BUG_ON(page_zone(start_page
) != page_zone(end_page
));
858 for (page
= start_page
; page
<= end_page
;) {
859 /* Make sure we are not inadvertently changing nodes */
860 VM_BUG_ON(page_to_nid(page
) != zone_to_nid(zone
));
862 if (!pfn_valid_within(page_to_pfn(page
))) {
867 if (!PageBuddy(page
)) {
872 order
= page_order(page
);
873 list_del(&page
->lru
);
875 &zone
->free_area
[order
].free_list
[migratetype
]);
877 pages_moved
+= 1 << order
;
883 static int move_freepages_block(struct zone
*zone
, struct page
*page
,
886 unsigned long start_pfn
, end_pfn
;
887 struct page
*start_page
, *end_page
;
889 start_pfn
= page_to_pfn(page
);
890 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
891 start_page
= pfn_to_page(start_pfn
);
892 end_page
= start_page
+ pageblock_nr_pages
- 1;
893 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
895 /* Do not cross zone boundaries */
896 if (start_pfn
< zone
->zone_start_pfn
)
898 if (end_pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
901 return move_freepages(zone
, start_page
, end_page
, migratetype
);
904 static void change_pageblock_range(struct page
*pageblock_page
,
905 int start_order
, int migratetype
)
907 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
909 while (nr_pageblocks
--) {
910 set_pageblock_migratetype(pageblock_page
, migratetype
);
911 pageblock_page
+= pageblock_nr_pages
;
915 /* Remove an element from the buddy allocator from the fallback list */
916 static inline struct page
*
917 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
)
919 struct free_area
* area
;
924 /* Find the largest possible block of pages in the other list */
925 for (current_order
= MAX_ORDER
-1; current_order
>= order
;
927 for (i
= 0; i
< MIGRATE_TYPES
- 1; i
++) {
928 migratetype
= fallbacks
[start_migratetype
][i
];
930 /* MIGRATE_RESERVE handled later if necessary */
931 if (migratetype
== MIGRATE_RESERVE
)
934 area
= &(zone
->free_area
[current_order
]);
935 if (list_empty(&area
->free_list
[migratetype
]))
938 page
= list_entry(area
->free_list
[migratetype
].next
,
943 * If breaking a large block of pages, move all free
944 * pages to the preferred allocation list. If falling
945 * back for a reclaimable kernel allocation, be more
946 * agressive about taking ownership of free pages
948 if (unlikely(current_order
>= (pageblock_order
>> 1)) ||
949 start_migratetype
== MIGRATE_RECLAIMABLE
||
950 page_group_by_mobility_disabled
) {
952 pages
= move_freepages_block(zone
, page
,
955 /* Claim the whole block if over half of it is free */
956 if (pages
>= (1 << (pageblock_order
-1)) ||
957 page_group_by_mobility_disabled
)
958 set_pageblock_migratetype(page
,
961 migratetype
= start_migratetype
;
964 /* Remove the page from the freelists */
965 list_del(&page
->lru
);
966 rmv_page_order(page
);
968 /* Take ownership for orders >= pageblock_order */
969 if (current_order
>= pageblock_order
)
970 change_pageblock_range(page
, current_order
,
973 expand(zone
, page
, order
, current_order
, area
, migratetype
);
975 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
976 start_migratetype
, migratetype
);
986 * Do the hard work of removing an element from the buddy allocator.
987 * Call me with the zone->lock already held.
989 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
995 page
= __rmqueue_smallest(zone
, order
, migratetype
);
997 if (unlikely(!page
) && migratetype
!= MIGRATE_RESERVE
) {
998 page
= __rmqueue_fallback(zone
, order
, migratetype
);
1001 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1002 * is used because __rmqueue_smallest is an inline function
1003 * and we want just one call site
1006 migratetype
= MIGRATE_RESERVE
;
1011 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1016 * Obtain a specified number of elements from the buddy allocator, all under
1017 * a single hold of the lock, for efficiency. Add them to the supplied list.
1018 * Returns the number of new pages which were placed at *list.
1020 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1021 unsigned long count
, struct list_head
*list
,
1022 int migratetype
, int cold
)
1026 spin_lock(&zone
->lock
);
1027 for (i
= 0; i
< count
; ++i
) {
1028 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
1029 if (unlikely(page
== NULL
))
1033 * Split buddy pages returned by expand() are received here
1034 * in physical page order. The page is added to the callers and
1035 * list and the list head then moves forward. From the callers
1036 * perspective, the linked list is ordered by page number in
1037 * some conditions. This is useful for IO devices that can
1038 * merge IO requests if the physical pages are ordered
1041 if (likely(cold
== 0))
1042 list_add(&page
->lru
, list
);
1044 list_add_tail(&page
->lru
, list
);
1045 set_page_private(page
, migratetype
);
1048 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
1049 spin_unlock(&zone
->lock
);
1055 * Called from the vmstat counter updater to drain pagesets of this
1056 * currently executing processor on remote nodes after they have
1059 * Note that this function must be called with the thread pinned to
1060 * a single processor.
1062 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
1064 unsigned long flags
;
1067 local_irq_save(flags
);
1068 if (pcp
->count
>= pcp
->batch
)
1069 to_drain
= pcp
->batch
;
1071 to_drain
= pcp
->count
;
1072 free_pcppages_bulk(zone
, to_drain
, pcp
);
1073 pcp
->count
-= to_drain
;
1074 local_irq_restore(flags
);
1079 * Drain pages of the indicated processor.
1081 * The processor must either be the current processor and the
1082 * thread pinned to the current processor or a processor that
1085 static void drain_pages(unsigned int cpu
)
1087 unsigned long flags
;
1090 for_each_populated_zone(zone
) {
1091 struct per_cpu_pageset
*pset
;
1092 struct per_cpu_pages
*pcp
;
1094 local_irq_save(flags
);
1095 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
1098 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1100 local_irq_restore(flags
);
1105 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1107 void drain_local_pages(void *arg
)
1109 drain_pages(smp_processor_id());
1113 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
1115 void drain_all_pages(void)
1117 on_each_cpu(drain_local_pages
, NULL
, 1);
1120 #ifdef CONFIG_HIBERNATION
1122 void mark_free_pages(struct zone
*zone
)
1124 unsigned long pfn
, max_zone_pfn
;
1125 unsigned long flags
;
1127 struct list_head
*curr
;
1129 if (!zone
->spanned_pages
)
1132 spin_lock_irqsave(&zone
->lock
, flags
);
1134 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
1135 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1136 if (pfn_valid(pfn
)) {
1137 struct page
*page
= pfn_to_page(pfn
);
1139 if (!swsusp_page_is_forbidden(page
))
1140 swsusp_unset_page_free(page
);
1143 for_each_migratetype_order(order
, t
) {
1144 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
1147 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
1148 for (i
= 0; i
< (1UL << order
); i
++)
1149 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
1152 spin_unlock_irqrestore(&zone
->lock
, flags
);
1154 #endif /* CONFIG_PM */
1157 * Free a 0-order page
1158 * cold == 1 ? free a cold page : free a hot page
1160 void free_hot_cold_page(struct page
*page
, int cold
)
1162 struct zone
*zone
= page_zone(page
);
1163 struct per_cpu_pages
*pcp
;
1164 unsigned long flags
;
1166 int wasMlocked
= __TestClearPageMlocked(page
);
1168 if (!free_pages_prepare(page
, 0))
1171 migratetype
= get_pageblock_migratetype(page
);
1172 set_page_private(page
, migratetype
);
1173 local_irq_save(flags
);
1174 if (unlikely(wasMlocked
))
1175 free_page_mlock(page
);
1176 __count_vm_event(PGFREE
);
1179 * We only track unmovable, reclaimable and movable on pcp lists.
1180 * Free ISOLATE pages back to the allocator because they are being
1181 * offlined but treat RESERVE as movable pages so we can get those
1182 * areas back if necessary. Otherwise, we may have to free
1183 * excessively into the page allocator
1185 if (migratetype
>= MIGRATE_PCPTYPES
) {
1186 if (unlikely(migratetype
== MIGRATE_ISOLATE
)) {
1187 free_one_page(zone
, page
, 0, migratetype
);
1190 migratetype
= MIGRATE_MOVABLE
;
1193 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1195 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
1197 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
1199 if (pcp
->count
>= pcp
->high
) {
1200 free_pcppages_bulk(zone
, pcp
->batch
, pcp
);
1201 pcp
->count
-= pcp
->batch
;
1205 local_irq_restore(flags
);
1209 * split_page takes a non-compound higher-order page, and splits it into
1210 * n (1<<order) sub-pages: page[0..n]
1211 * Each sub-page must be freed individually.
1213 * Note: this is probably too low level an operation for use in drivers.
1214 * Please consult with lkml before using this in your driver.
1216 void split_page(struct page
*page
, unsigned int order
)
1220 VM_BUG_ON(PageCompound(page
));
1221 VM_BUG_ON(!page_count(page
));
1223 #ifdef CONFIG_KMEMCHECK
1225 * Split shadow pages too, because free(page[0]) would
1226 * otherwise free the whole shadow.
1228 if (kmemcheck_page_is_tracked(page
))
1229 split_page(virt_to_page(page
[0].shadow
), order
);
1232 for (i
= 1; i
< (1 << order
); i
++)
1233 set_page_refcounted(page
+ i
);
1237 * Similar to split_page except the page is already free. As this is only
1238 * being used for migration, the migratetype of the block also changes.
1239 * As this is called with interrupts disabled, the caller is responsible
1240 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1243 * Note: this is probably too low level an operation for use in drivers.
1244 * Please consult with lkml before using this in your driver.
1246 int split_free_page(struct page
*page
)
1249 unsigned long watermark
;
1252 BUG_ON(!PageBuddy(page
));
1254 zone
= page_zone(page
);
1255 order
= page_order(page
);
1257 /* Obey watermarks as if the page was being allocated */
1258 watermark
= low_wmark_pages(zone
) + (1 << order
);
1259 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
1262 /* Remove page from free list */
1263 list_del(&page
->lru
);
1264 zone
->free_area
[order
].nr_free
--;
1265 rmv_page_order(page
);
1266 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(1UL << order
));
1268 /* Split into individual pages */
1269 set_page_refcounted(page
);
1270 split_page(page
, order
);
1272 if (order
>= pageblock_order
- 1) {
1273 struct page
*endpage
= page
+ (1 << order
) - 1;
1274 for (; page
< endpage
; page
+= pageblock_nr_pages
)
1275 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1282 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1283 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1287 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
1288 struct zone
*zone
, int order
, gfp_t gfp_flags
,
1291 unsigned long flags
;
1293 int cold
= !!(gfp_flags
& __GFP_COLD
);
1296 if (likely(order
== 0)) {
1297 struct per_cpu_pages
*pcp
;
1298 struct list_head
*list
;
1300 local_irq_save(flags
);
1301 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1302 list
= &pcp
->lists
[migratetype
];
1303 if (list_empty(list
)) {
1304 pcp
->count
+= rmqueue_bulk(zone
, 0,
1307 if (unlikely(list_empty(list
)))
1312 page
= list_entry(list
->prev
, struct page
, lru
);
1314 page
= list_entry(list
->next
, struct page
, lru
);
1316 list_del(&page
->lru
);
1319 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
1321 * __GFP_NOFAIL is not to be used in new code.
1323 * All __GFP_NOFAIL callers should be fixed so that they
1324 * properly detect and handle allocation failures.
1326 * We most definitely don't want callers attempting to
1327 * allocate greater than order-1 page units with
1330 WARN_ON_ONCE(order
> 1);
1332 spin_lock_irqsave(&zone
->lock
, flags
);
1333 page
= __rmqueue(zone
, order
, migratetype
);
1334 spin_unlock(&zone
->lock
);
1337 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(1 << order
));
1340 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
1341 zone_statistics(preferred_zone
, zone
);
1342 local_irq_restore(flags
);
1344 VM_BUG_ON(bad_range(zone
, page
));
1345 if (prep_new_page(page
, order
, gfp_flags
))
1350 local_irq_restore(flags
);
1354 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
1355 #define ALLOC_WMARK_MIN WMARK_MIN
1356 #define ALLOC_WMARK_LOW WMARK_LOW
1357 #define ALLOC_WMARK_HIGH WMARK_HIGH
1358 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
1360 /* Mask to get the watermark bits */
1361 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
1363 #define ALLOC_HARDER 0x10 /* try to alloc harder */
1364 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
1365 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
1367 #ifdef CONFIG_FAIL_PAGE_ALLOC
1369 static struct fail_page_alloc_attr
{
1370 struct fault_attr attr
;
1372 u32 ignore_gfp_highmem
;
1373 u32 ignore_gfp_wait
;
1376 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1378 struct dentry
*ignore_gfp_highmem_file
;
1379 struct dentry
*ignore_gfp_wait_file
;
1380 struct dentry
*min_order_file
;
1382 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1384 } fail_page_alloc
= {
1385 .attr
= FAULT_ATTR_INITIALIZER
,
1386 .ignore_gfp_wait
= 1,
1387 .ignore_gfp_highmem
= 1,
1391 static int __init
setup_fail_page_alloc(char *str
)
1393 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
1395 __setup("fail_page_alloc=", setup_fail_page_alloc
);
1397 static int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1399 if (order
< fail_page_alloc
.min_order
)
1401 if (gfp_mask
& __GFP_NOFAIL
)
1403 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
1405 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
1408 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
1411 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1413 static int __init
fail_page_alloc_debugfs(void)
1415 mode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
1419 err
= init_fault_attr_dentries(&fail_page_alloc
.attr
,
1423 dir
= fail_page_alloc
.attr
.dentries
.dir
;
1425 fail_page_alloc
.ignore_gfp_wait_file
=
1426 debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
1427 &fail_page_alloc
.ignore_gfp_wait
);
1429 fail_page_alloc
.ignore_gfp_highmem_file
=
1430 debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
1431 &fail_page_alloc
.ignore_gfp_highmem
);
1432 fail_page_alloc
.min_order_file
=
1433 debugfs_create_u32("min-order", mode
, dir
,
1434 &fail_page_alloc
.min_order
);
1436 if (!fail_page_alloc
.ignore_gfp_wait_file
||
1437 !fail_page_alloc
.ignore_gfp_highmem_file
||
1438 !fail_page_alloc
.min_order_file
) {
1440 debugfs_remove(fail_page_alloc
.ignore_gfp_wait_file
);
1441 debugfs_remove(fail_page_alloc
.ignore_gfp_highmem_file
);
1442 debugfs_remove(fail_page_alloc
.min_order_file
);
1443 cleanup_fault_attr_dentries(&fail_page_alloc
.attr
);
1449 late_initcall(fail_page_alloc_debugfs
);
1451 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1453 #else /* CONFIG_FAIL_PAGE_ALLOC */
1455 static inline int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1460 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1463 * Return true if free pages are above 'mark'. This takes into account the order
1464 * of the allocation.
1466 static bool __zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1467 int classzone_idx
, int alloc_flags
, long free_pages
)
1469 /* free_pages my go negative - that's OK */
1473 free_pages
-= (1 << order
) + 1;
1474 if (alloc_flags
& ALLOC_HIGH
)
1476 if (alloc_flags
& ALLOC_HARDER
)
1479 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
1481 for (o
= 0; o
< order
; o
++) {
1482 /* At the next order, this order's pages become unavailable */
1483 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1485 /* Require fewer higher order pages to be free */
1488 if (free_pages
<= min
)
1494 bool zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1495 int classzone_idx
, int alloc_flags
)
1497 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1498 zone_page_state(z
, NR_FREE_PAGES
));
1501 bool zone_watermark_ok_safe(struct zone
*z
, int order
, unsigned long mark
,
1502 int classzone_idx
, int alloc_flags
)
1504 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
1506 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
1507 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
1509 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1515 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1516 * skip over zones that are not allowed by the cpuset, or that have
1517 * been recently (in last second) found to be nearly full. See further
1518 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1519 * that have to skip over a lot of full or unallowed zones.
1521 * If the zonelist cache is present in the passed in zonelist, then
1522 * returns a pointer to the allowed node mask (either the current
1523 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1525 * If the zonelist cache is not available for this zonelist, does
1526 * nothing and returns NULL.
1528 * If the fullzones BITMAP in the zonelist cache is stale (more than
1529 * a second since last zap'd) then we zap it out (clear its bits.)
1531 * We hold off even calling zlc_setup, until after we've checked the
1532 * first zone in the zonelist, on the theory that most allocations will
1533 * be satisfied from that first zone, so best to examine that zone as
1534 * quickly as we can.
1536 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1538 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1539 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1541 zlc
= zonelist
->zlcache_ptr
;
1545 if (time_after(jiffies
, zlc
->last_full_zap
+ HZ
)) {
1546 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1547 zlc
->last_full_zap
= jiffies
;
1550 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1551 &cpuset_current_mems_allowed
:
1552 &node_states
[N_HIGH_MEMORY
];
1553 return allowednodes
;
1557 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1558 * if it is worth looking at further for free memory:
1559 * 1) Check that the zone isn't thought to be full (doesn't have its
1560 * bit set in the zonelist_cache fullzones BITMAP).
1561 * 2) Check that the zones node (obtained from the zonelist_cache
1562 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1563 * Return true (non-zero) if zone is worth looking at further, or
1564 * else return false (zero) if it is not.
1566 * This check -ignores- the distinction between various watermarks,
1567 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1568 * found to be full for any variation of these watermarks, it will
1569 * be considered full for up to one second by all requests, unless
1570 * we are so low on memory on all allowed nodes that we are forced
1571 * into the second scan of the zonelist.
1573 * In the second scan we ignore this zonelist cache and exactly
1574 * apply the watermarks to all zones, even it is slower to do so.
1575 * We are low on memory in the second scan, and should leave no stone
1576 * unturned looking for a free page.
1578 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1579 nodemask_t
*allowednodes
)
1581 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1582 int i
; /* index of *z in zonelist zones */
1583 int n
; /* node that zone *z is on */
1585 zlc
= zonelist
->zlcache_ptr
;
1589 i
= z
- zonelist
->_zonerefs
;
1592 /* This zone is worth trying if it is allowed but not full */
1593 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1597 * Given 'z' scanning a zonelist, set the corresponding bit in
1598 * zlc->fullzones, so that subsequent attempts to allocate a page
1599 * from that zone don't waste time re-examining it.
1601 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1603 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1604 int i
; /* index of *z in zonelist zones */
1606 zlc
= zonelist
->zlcache_ptr
;
1610 i
= z
- zonelist
->_zonerefs
;
1612 set_bit(i
, zlc
->fullzones
);
1615 #else /* CONFIG_NUMA */
1617 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1622 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1623 nodemask_t
*allowednodes
)
1628 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1631 #endif /* CONFIG_NUMA */
1634 * get_page_from_freelist goes through the zonelist trying to allocate
1637 static struct page
*
1638 get_page_from_freelist(gfp_t gfp_mask
, nodemask_t
*nodemask
, unsigned int order
,
1639 struct zonelist
*zonelist
, int high_zoneidx
, int alloc_flags
,
1640 struct zone
*preferred_zone
, int migratetype
)
1643 struct page
*page
= NULL
;
1646 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1647 int zlc_active
= 0; /* set if using zonelist_cache */
1648 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1650 classzone_idx
= zone_idx(preferred_zone
);
1653 * Scan zonelist, looking for a zone with enough free.
1654 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1656 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
1657 high_zoneidx
, nodemask
) {
1658 if (NUMA_BUILD
&& zlc_active
&&
1659 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1661 if ((alloc_flags
& ALLOC_CPUSET
) &&
1662 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1665 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
1666 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
1670 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
1671 if (zone_watermark_ok(zone
, order
, mark
,
1672 classzone_idx
, alloc_flags
))
1675 if (zone_reclaim_mode
== 0)
1676 goto this_zone_full
;
1678 ret
= zone_reclaim(zone
, gfp_mask
, order
);
1680 case ZONE_RECLAIM_NOSCAN
:
1683 case ZONE_RECLAIM_FULL
:
1684 /* scanned but unreclaimable */
1685 goto this_zone_full
;
1687 /* did we reclaim enough */
1688 if (!zone_watermark_ok(zone
, order
, mark
,
1689 classzone_idx
, alloc_flags
))
1690 goto this_zone_full
;
1695 page
= buffered_rmqueue(preferred_zone
, zone
, order
,
1696 gfp_mask
, migratetype
);
1701 zlc_mark_zone_full(zonelist
, z
);
1703 if (NUMA_BUILD
&& !did_zlc_setup
&& nr_online_nodes
> 1) {
1705 * we do zlc_setup after the first zone is tried but only
1706 * if there are multiple nodes make it worthwhile
1708 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1714 if (unlikely(NUMA_BUILD
&& page
== NULL
&& zlc_active
)) {
1715 /* Disable zlc cache for second zonelist scan */
1723 should_alloc_retry(gfp_t gfp_mask
, unsigned int order
,
1724 unsigned long pages_reclaimed
)
1726 /* Do not loop if specifically requested */
1727 if (gfp_mask
& __GFP_NORETRY
)
1731 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
1732 * means __GFP_NOFAIL, but that may not be true in other
1735 if (order
<= PAGE_ALLOC_COSTLY_ORDER
)
1739 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
1740 * specified, then we retry until we no longer reclaim any pages
1741 * (above), or we've reclaimed an order of pages at least as
1742 * large as the allocation's order. In both cases, if the
1743 * allocation still fails, we stop retrying.
1745 if (gfp_mask
& __GFP_REPEAT
&& pages_reclaimed
< (1 << order
))
1749 * Don't let big-order allocations loop unless the caller
1750 * explicitly requests that.
1752 if (gfp_mask
& __GFP_NOFAIL
)
1758 static inline struct page
*
1759 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
1760 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1761 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
1766 /* Acquire the OOM killer lock for the zones in zonelist */
1767 if (!try_set_zonelist_oom(zonelist
, gfp_mask
)) {
1768 schedule_timeout_uninterruptible(1);
1773 * Go through the zonelist yet one more time, keep very high watermark
1774 * here, this is only to catch a parallel oom killing, we must fail if
1775 * we're still under heavy pressure.
1777 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
,
1778 order
, zonelist
, high_zoneidx
,
1779 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
,
1780 preferred_zone
, migratetype
);
1784 if (!(gfp_mask
& __GFP_NOFAIL
)) {
1785 /* The OOM killer will not help higher order allocs */
1786 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
1788 /* The OOM killer does not needlessly kill tasks for lowmem */
1789 if (high_zoneidx
< ZONE_NORMAL
)
1792 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
1793 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
1794 * The caller should handle page allocation failure by itself if
1795 * it specifies __GFP_THISNODE.
1796 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
1798 if (gfp_mask
& __GFP_THISNODE
)
1801 /* Exhausted what can be done so it's blamo time */
1802 out_of_memory(zonelist
, gfp_mask
, order
, nodemask
);
1805 clear_zonelist_oom(zonelist
, gfp_mask
);
1809 #ifdef CONFIG_COMPACTION
1810 /* Try memory compaction for high-order allocations before reclaim */
1811 static struct page
*
1812 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
1813 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1814 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
1815 int migratetype
, unsigned long *did_some_progress
,
1816 bool sync_migration
)
1819 struct task_struct
*tsk
= current
;
1821 if (!order
|| compaction_deferred(preferred_zone
))
1824 tsk
->flags
|= PF_MEMALLOC
;
1825 *did_some_progress
= try_to_compact_pages(zonelist
, order
, gfp_mask
,
1826 nodemask
, sync_migration
);
1827 tsk
->flags
&= ~PF_MEMALLOC
;
1828 if (*did_some_progress
!= COMPACT_SKIPPED
) {
1830 /* Page migration frees to the PCP lists but we want merging */
1831 drain_pages(get_cpu());
1834 page
= get_page_from_freelist(gfp_mask
, nodemask
,
1835 order
, zonelist
, high_zoneidx
,
1836 alloc_flags
, preferred_zone
,
1839 preferred_zone
->compact_considered
= 0;
1840 preferred_zone
->compact_defer_shift
= 0;
1841 count_vm_event(COMPACTSUCCESS
);
1846 * It's bad if compaction run occurs and fails.
1847 * The most likely reason is that pages exist,
1848 * but not enough to satisfy watermarks.
1850 count_vm_event(COMPACTFAIL
);
1851 defer_compaction(preferred_zone
);
1859 static inline struct page
*
1860 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
1861 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1862 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
1863 int migratetype
, unsigned long *did_some_progress
,
1864 bool sync_migration
)
1868 #endif /* CONFIG_COMPACTION */
1870 /* The really slow allocator path where we enter direct reclaim */
1871 static inline struct page
*
1872 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
1873 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1874 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
1875 int migratetype
, unsigned long *did_some_progress
)
1877 struct page
*page
= NULL
;
1878 struct reclaim_state reclaim_state
;
1879 struct task_struct
*p
= current
;
1880 bool drained
= false;
1884 /* We now go into synchronous reclaim */
1885 cpuset_memory_pressure_bump();
1886 p
->flags
|= PF_MEMALLOC
;
1887 lockdep_set_current_reclaim_state(gfp_mask
);
1888 reclaim_state
.reclaimed_slab
= 0;
1889 p
->reclaim_state
= &reclaim_state
;
1891 *did_some_progress
= try_to_free_pages(zonelist
, order
, gfp_mask
, nodemask
);
1893 p
->reclaim_state
= NULL
;
1894 lockdep_clear_current_reclaim_state();
1895 p
->flags
&= ~PF_MEMALLOC
;
1899 if (unlikely(!(*did_some_progress
)))
1903 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
1904 zonelist
, high_zoneidx
,
1905 alloc_flags
, preferred_zone
,
1909 * If an allocation failed after direct reclaim, it could be because
1910 * pages are pinned on the per-cpu lists. Drain them and try again
1912 if (!page
&& !drained
) {
1922 * This is called in the allocator slow-path if the allocation request is of
1923 * sufficient urgency to ignore watermarks and take other desperate measures
1925 static inline struct page
*
1926 __alloc_pages_high_priority(gfp_t gfp_mask
, unsigned int order
,
1927 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1928 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
1934 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
1935 zonelist
, high_zoneidx
, ALLOC_NO_WATERMARKS
,
1936 preferred_zone
, migratetype
);
1938 if (!page
&& gfp_mask
& __GFP_NOFAIL
)
1939 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
1940 } while (!page
&& (gfp_mask
& __GFP_NOFAIL
));
1946 void wake_all_kswapd(unsigned int order
, struct zonelist
*zonelist
,
1947 enum zone_type high_zoneidx
)
1952 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
)
1953 wakeup_kswapd(zone
, order
);
1957 gfp_to_alloc_flags(gfp_t gfp_mask
)
1959 struct task_struct
*p
= current
;
1960 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
1961 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
1963 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
1964 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
1967 * The caller may dip into page reserves a bit more if the caller
1968 * cannot run direct reclaim, or if the caller has realtime scheduling
1969 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
1970 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1972 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
1975 alloc_flags
|= ALLOC_HARDER
;
1977 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1978 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1980 alloc_flags
&= ~ALLOC_CPUSET
;
1981 } else if (unlikely(rt_task(p
)) && !in_interrupt())
1982 alloc_flags
|= ALLOC_HARDER
;
1984 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
1985 if (!in_interrupt() &&
1986 ((p
->flags
& PF_MEMALLOC
) ||
1987 unlikely(test_thread_flag(TIF_MEMDIE
))))
1988 alloc_flags
|= ALLOC_NO_WATERMARKS
;
1994 static inline struct page
*
1995 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
1996 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1997 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2000 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2001 struct page
*page
= NULL
;
2003 unsigned long pages_reclaimed
= 0;
2004 unsigned long did_some_progress
;
2005 struct task_struct
*p
= current
;
2006 bool sync_migration
= false;
2009 * In the slowpath, we sanity check order to avoid ever trying to
2010 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2011 * be using allocators in order of preference for an area that is
2014 if (order
>= MAX_ORDER
) {
2015 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
2020 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
2021 * __GFP_NOWARN set) should not cause reclaim since the subsystem
2022 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
2023 * using a larger set of nodes after it has established that the
2024 * allowed per node queues are empty and that nodes are
2027 if (NUMA_BUILD
&& (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
2031 wake_all_kswapd(order
, zonelist
, high_zoneidx
);
2034 * OK, we're below the kswapd watermark and have kicked background
2035 * reclaim. Now things get more complex, so set up alloc_flags according
2036 * to how we want to proceed.
2038 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
2040 /* This is the last chance, in general, before the goto nopage. */
2041 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
, zonelist
,
2042 high_zoneidx
, alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2043 preferred_zone
, migratetype
);
2048 /* Allocate without watermarks if the context allows */
2049 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
2050 page
= __alloc_pages_high_priority(gfp_mask
, order
,
2051 zonelist
, high_zoneidx
, nodemask
,
2052 preferred_zone
, migratetype
);
2057 /* Atomic allocations - we can't balance anything */
2061 /* Avoid recursion of direct reclaim */
2062 if (p
->flags
& PF_MEMALLOC
)
2065 /* Avoid allocations with no watermarks from looping endlessly */
2066 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
2070 * Try direct compaction. The first pass is asynchronous. Subsequent
2071 * attempts after direct reclaim are synchronous
2073 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
2074 zonelist
, high_zoneidx
,
2076 alloc_flags
, preferred_zone
,
2077 migratetype
, &did_some_progress
,
2081 sync_migration
= true;
2083 /* Try direct reclaim and then allocating */
2084 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
,
2085 zonelist
, high_zoneidx
,
2087 alloc_flags
, preferred_zone
,
2088 migratetype
, &did_some_progress
);
2093 * If we failed to make any progress reclaiming, then we are
2094 * running out of options and have to consider going OOM
2096 if (!did_some_progress
) {
2097 if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
2098 if (oom_killer_disabled
)
2100 page
= __alloc_pages_may_oom(gfp_mask
, order
,
2101 zonelist
, high_zoneidx
,
2102 nodemask
, preferred_zone
,
2107 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2109 * The oom killer is not called for high-order
2110 * allocations that may fail, so if no progress
2111 * is being made, there are no other options and
2112 * retrying is unlikely to help.
2114 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2117 * The oom killer is not called for lowmem
2118 * allocations to prevent needlessly killing
2121 if (high_zoneidx
< ZONE_NORMAL
)
2129 /* Check if we should retry the allocation */
2130 pages_reclaimed
+= did_some_progress
;
2131 if (should_alloc_retry(gfp_mask
, order
, pages_reclaimed
)) {
2132 /* Wait for some write requests to complete then retry */
2133 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2137 * High-order allocations do not necessarily loop after
2138 * direct reclaim and reclaim/compaction depends on compaction
2139 * being called after reclaim so call directly if necessary
2141 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
2142 zonelist
, high_zoneidx
,
2144 alloc_flags
, preferred_zone
,
2145 migratetype
, &did_some_progress
,
2152 if (!(gfp_mask
& __GFP_NOWARN
) && printk_ratelimit()) {
2153 printk(KERN_WARNING
"%s: page allocation failure."
2154 " order:%d, mode:0x%x\n",
2155 p
->comm
, order
, gfp_mask
);
2161 if (kmemcheck_enabled
)
2162 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
2168 * This is the 'heart' of the zoned buddy allocator.
2171 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
2172 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
2174 enum zone_type high_zoneidx
= gfp_zone(gfp_mask
);
2175 struct zone
*preferred_zone
;
2177 int migratetype
= allocflags_to_migratetype(gfp_mask
);
2179 gfp_mask
&= gfp_allowed_mask
;
2181 lockdep_trace_alloc(gfp_mask
);
2183 might_sleep_if(gfp_mask
& __GFP_WAIT
);
2185 if (should_fail_alloc_page(gfp_mask
, order
))
2189 * Check the zones suitable for the gfp_mask contain at least one
2190 * valid zone. It's possible to have an empty zonelist as a result
2191 * of GFP_THISNODE and a memoryless node
2193 if (unlikely(!zonelist
->_zonerefs
->zone
))
2197 /* The preferred zone is used for statistics later */
2198 first_zones_zonelist(zonelist
, high_zoneidx
, nodemask
, &preferred_zone
);
2199 if (!preferred_zone
) {
2204 /* First allocation attempt */
2205 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
, order
,
2206 zonelist
, high_zoneidx
, ALLOC_WMARK_LOW
|ALLOC_CPUSET
,
2207 preferred_zone
, migratetype
);
2208 if (unlikely(!page
))
2209 page
= __alloc_pages_slowpath(gfp_mask
, order
,
2210 zonelist
, high_zoneidx
, nodemask
,
2211 preferred_zone
, migratetype
);
2214 trace_mm_page_alloc(page
, order
, gfp_mask
, migratetype
);
2217 EXPORT_SYMBOL(__alloc_pages_nodemask
);
2220 * Common helper functions.
2222 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
2227 * __get_free_pages() returns a 32-bit address, which cannot represent
2230 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
2232 page
= alloc_pages(gfp_mask
, order
);
2235 return (unsigned long) page_address(page
);
2237 EXPORT_SYMBOL(__get_free_pages
);
2239 unsigned long get_zeroed_page(gfp_t gfp_mask
)
2241 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
2243 EXPORT_SYMBOL(get_zeroed_page
);
2245 void __pagevec_free(struct pagevec
*pvec
)
2247 int i
= pagevec_count(pvec
);
2250 trace_mm_pagevec_free(pvec
->pages
[i
], pvec
->cold
);
2251 free_hot_cold_page(pvec
->pages
[i
], pvec
->cold
);
2255 void __free_pages(struct page
*page
, unsigned int order
)
2257 if (put_page_testzero(page
)) {
2259 free_hot_cold_page(page
, 0);
2261 __free_pages_ok(page
, order
);
2265 EXPORT_SYMBOL(__free_pages
);
2267 void free_pages(unsigned long addr
, unsigned int order
)
2270 VM_BUG_ON(!virt_addr_valid((void *)addr
));
2271 __free_pages(virt_to_page((void *)addr
), order
);
2275 EXPORT_SYMBOL(free_pages
);
2278 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2279 * @size: the number of bytes to allocate
2280 * @gfp_mask: GFP flags for the allocation
2282 * This function is similar to alloc_pages(), except that it allocates the
2283 * minimum number of pages to satisfy the request. alloc_pages() can only
2284 * allocate memory in power-of-two pages.
2286 * This function is also limited by MAX_ORDER.
2288 * Memory allocated by this function must be released by free_pages_exact().
2290 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
2292 unsigned int order
= get_order(size
);
2295 addr
= __get_free_pages(gfp_mask
, order
);
2297 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
2298 unsigned long used
= addr
+ PAGE_ALIGN(size
);
2300 split_page(virt_to_page((void *)addr
), order
);
2301 while (used
< alloc_end
) {
2307 return (void *)addr
;
2309 EXPORT_SYMBOL(alloc_pages_exact
);
2312 * free_pages_exact - release memory allocated via alloc_pages_exact()
2313 * @virt: the value returned by alloc_pages_exact.
2314 * @size: size of allocation, same value as passed to alloc_pages_exact().
2316 * Release the memory allocated by a previous call to alloc_pages_exact.
2318 void free_pages_exact(void *virt
, size_t size
)
2320 unsigned long addr
= (unsigned long)virt
;
2321 unsigned long end
= addr
+ PAGE_ALIGN(size
);
2323 while (addr
< end
) {
2328 EXPORT_SYMBOL(free_pages_exact
);
2330 static unsigned int nr_free_zone_pages(int offset
)
2335 /* Just pick one node, since fallback list is circular */
2336 unsigned int sum
= 0;
2338 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
2340 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
2341 unsigned long size
= zone
->present_pages
;
2342 unsigned long high
= high_wmark_pages(zone
);
2351 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
2353 unsigned int nr_free_buffer_pages(void)
2355 return nr_free_zone_pages(gfp_zone(GFP_USER
));
2357 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
2360 * Amount of free RAM allocatable within all zones
2362 unsigned int nr_free_pagecache_pages(void)
2364 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
2367 static inline void show_node(struct zone
*zone
)
2370 printk("Node %d ", zone_to_nid(zone
));
2373 void si_meminfo(struct sysinfo
*val
)
2375 val
->totalram
= totalram_pages
;
2377 val
->freeram
= global_page_state(NR_FREE_PAGES
);
2378 val
->bufferram
= nr_blockdev_pages();
2379 val
->totalhigh
= totalhigh_pages
;
2380 val
->freehigh
= nr_free_highpages();
2381 val
->mem_unit
= PAGE_SIZE
;
2384 EXPORT_SYMBOL(si_meminfo
);
2387 void si_meminfo_node(struct sysinfo
*val
, int nid
)
2389 pg_data_t
*pgdat
= NODE_DATA(nid
);
2391 val
->totalram
= pgdat
->node_present_pages
;
2392 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
2393 #ifdef CONFIG_HIGHMEM
2394 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
2395 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
2401 val
->mem_unit
= PAGE_SIZE
;
2405 #define K(x) ((x) << (PAGE_SHIFT-10))
2408 * Show free area list (used inside shift_scroll-lock stuff)
2409 * We also calculate the percentage fragmentation. We do this by counting the
2410 * memory on each free list with the exception of the first item on the list.
2412 void show_free_areas(void)
2417 for_each_populated_zone(zone
) {
2419 printk("%s per-cpu:\n", zone
->name
);
2421 for_each_online_cpu(cpu
) {
2422 struct per_cpu_pageset
*pageset
;
2424 pageset
= per_cpu_ptr(zone
->pageset
, cpu
);
2426 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
2427 cpu
, pageset
->pcp
.high
,
2428 pageset
->pcp
.batch
, pageset
->pcp
.count
);
2432 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
2433 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
2435 " dirty:%lu writeback:%lu unstable:%lu\n"
2436 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2437 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
2438 global_page_state(NR_ACTIVE_ANON
),
2439 global_page_state(NR_INACTIVE_ANON
),
2440 global_page_state(NR_ISOLATED_ANON
),
2441 global_page_state(NR_ACTIVE_FILE
),
2442 global_page_state(NR_INACTIVE_FILE
),
2443 global_page_state(NR_ISOLATED_FILE
),
2444 global_page_state(NR_UNEVICTABLE
),
2445 global_page_state(NR_FILE_DIRTY
),
2446 global_page_state(NR_WRITEBACK
),
2447 global_page_state(NR_UNSTABLE_NFS
),
2448 global_page_state(NR_FREE_PAGES
),
2449 global_page_state(NR_SLAB_RECLAIMABLE
),
2450 global_page_state(NR_SLAB_UNRECLAIMABLE
),
2451 global_page_state(NR_FILE_MAPPED
),
2452 global_page_state(NR_SHMEM
),
2453 global_page_state(NR_PAGETABLE
),
2454 global_page_state(NR_BOUNCE
));
2456 for_each_populated_zone(zone
) {
2465 " active_anon:%lukB"
2466 " inactive_anon:%lukB"
2467 " active_file:%lukB"
2468 " inactive_file:%lukB"
2469 " unevictable:%lukB"
2470 " isolated(anon):%lukB"
2471 " isolated(file):%lukB"
2478 " slab_reclaimable:%lukB"
2479 " slab_unreclaimable:%lukB"
2480 " kernel_stack:%lukB"
2484 " writeback_tmp:%lukB"
2485 " pages_scanned:%lu"
2486 " all_unreclaimable? %s"
2489 K(zone_page_state(zone
, NR_FREE_PAGES
)),
2490 K(min_wmark_pages(zone
)),
2491 K(low_wmark_pages(zone
)),
2492 K(high_wmark_pages(zone
)),
2493 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
2494 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
2495 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
2496 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
2497 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
2498 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
2499 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
2500 K(zone
->present_pages
),
2501 K(zone_page_state(zone
, NR_MLOCK
)),
2502 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
2503 K(zone_page_state(zone
, NR_WRITEBACK
)),
2504 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
2505 K(zone_page_state(zone
, NR_SHMEM
)),
2506 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
2507 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
2508 zone_page_state(zone
, NR_KERNEL_STACK
) *
2510 K(zone_page_state(zone
, NR_PAGETABLE
)),
2511 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
2512 K(zone_page_state(zone
, NR_BOUNCE
)),
2513 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
2514 zone
->pages_scanned
,
2515 (zone
->all_unreclaimable
? "yes" : "no")
2517 printk("lowmem_reserve[]:");
2518 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
2519 printk(" %lu", zone
->lowmem_reserve
[i
]);
2523 for_each_populated_zone(zone
) {
2524 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
2527 printk("%s: ", zone
->name
);
2529 spin_lock_irqsave(&zone
->lock
, flags
);
2530 for (order
= 0; order
< MAX_ORDER
; order
++) {
2531 nr
[order
] = zone
->free_area
[order
].nr_free
;
2532 total
+= nr
[order
] << order
;
2534 spin_unlock_irqrestore(&zone
->lock
, flags
);
2535 for (order
= 0; order
< MAX_ORDER
; order
++)
2536 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
2537 printk("= %lukB\n", K(total
));
2540 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
2542 show_swap_cache_info();
2545 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
2547 zoneref
->zone
= zone
;
2548 zoneref
->zone_idx
= zone_idx(zone
);
2552 * Builds allocation fallback zone lists.
2554 * Add all populated zones of a node to the zonelist.
2556 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
2557 int nr_zones
, enum zone_type zone_type
)
2561 BUG_ON(zone_type
>= MAX_NR_ZONES
);
2566 zone
= pgdat
->node_zones
+ zone_type
;
2567 if (populated_zone(zone
)) {
2568 zoneref_set_zone(zone
,
2569 &zonelist
->_zonerefs
[nr_zones
++]);
2570 check_highest_zone(zone_type
);
2573 } while (zone_type
);
2580 * 0 = automatic detection of better ordering.
2581 * 1 = order by ([node] distance, -zonetype)
2582 * 2 = order by (-zonetype, [node] distance)
2584 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
2585 * the same zonelist. So only NUMA can configure this param.
2587 #define ZONELIST_ORDER_DEFAULT 0
2588 #define ZONELIST_ORDER_NODE 1
2589 #define ZONELIST_ORDER_ZONE 2
2591 /* zonelist order in the kernel.
2592 * set_zonelist_order() will set this to NODE or ZONE.
2594 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2595 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
2599 /* The value user specified ....changed by config */
2600 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2601 /* string for sysctl */
2602 #define NUMA_ZONELIST_ORDER_LEN 16
2603 char numa_zonelist_order
[16] = "default";
2606 * interface for configure zonelist ordering.
2607 * command line option "numa_zonelist_order"
2608 * = "[dD]efault - default, automatic configuration.
2609 * = "[nN]ode - order by node locality, then by zone within node
2610 * = "[zZ]one - order by zone, then by locality within zone
2613 static int __parse_numa_zonelist_order(char *s
)
2615 if (*s
== 'd' || *s
== 'D') {
2616 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2617 } else if (*s
== 'n' || *s
== 'N') {
2618 user_zonelist_order
= ZONELIST_ORDER_NODE
;
2619 } else if (*s
== 'z' || *s
== 'Z') {
2620 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
2623 "Ignoring invalid numa_zonelist_order value: "
2630 static __init
int setup_numa_zonelist_order(char *s
)
2633 return __parse_numa_zonelist_order(s
);
2636 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
2639 * sysctl handler for numa_zonelist_order
2641 int numa_zonelist_order_handler(ctl_table
*table
, int write
,
2642 void __user
*buffer
, size_t *length
,
2645 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
2647 static DEFINE_MUTEX(zl_order_mutex
);
2649 mutex_lock(&zl_order_mutex
);
2651 strcpy(saved_string
, (char*)table
->data
);
2652 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
2656 int oldval
= user_zonelist_order
;
2657 if (__parse_numa_zonelist_order((char*)table
->data
)) {
2659 * bogus value. restore saved string
2661 strncpy((char*)table
->data
, saved_string
,
2662 NUMA_ZONELIST_ORDER_LEN
);
2663 user_zonelist_order
= oldval
;
2664 } else if (oldval
!= user_zonelist_order
) {
2665 mutex_lock(&zonelists_mutex
);
2666 build_all_zonelists(NULL
);
2667 mutex_unlock(&zonelists_mutex
);
2671 mutex_unlock(&zl_order_mutex
);
2676 #define MAX_NODE_LOAD (nr_online_nodes)
2677 static int node_load
[MAX_NUMNODES
];
2680 * find_next_best_node - find the next node that should appear in a given node's fallback list
2681 * @node: node whose fallback list we're appending
2682 * @used_node_mask: nodemask_t of already used nodes
2684 * We use a number of factors to determine which is the next node that should
2685 * appear on a given node's fallback list. The node should not have appeared
2686 * already in @node's fallback list, and it should be the next closest node
2687 * according to the distance array (which contains arbitrary distance values
2688 * from each node to each node in the system), and should also prefer nodes
2689 * with no CPUs, since presumably they'll have very little allocation pressure
2690 * on them otherwise.
2691 * It returns -1 if no node is found.
2693 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
2696 int min_val
= INT_MAX
;
2698 const struct cpumask
*tmp
= cpumask_of_node(0);
2700 /* Use the local node if we haven't already */
2701 if (!node_isset(node
, *used_node_mask
)) {
2702 node_set(node
, *used_node_mask
);
2706 for_each_node_state(n
, N_HIGH_MEMORY
) {
2708 /* Don't want a node to appear more than once */
2709 if (node_isset(n
, *used_node_mask
))
2712 /* Use the distance array to find the distance */
2713 val
= node_distance(node
, n
);
2715 /* Penalize nodes under us ("prefer the next node") */
2718 /* Give preference to headless and unused nodes */
2719 tmp
= cpumask_of_node(n
);
2720 if (!cpumask_empty(tmp
))
2721 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
2723 /* Slight preference for less loaded node */
2724 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
2725 val
+= node_load
[n
];
2727 if (val
< min_val
) {
2734 node_set(best_node
, *used_node_mask
);
2741 * Build zonelists ordered by node and zones within node.
2742 * This results in maximum locality--normal zone overflows into local
2743 * DMA zone, if any--but risks exhausting DMA zone.
2745 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
2748 struct zonelist
*zonelist
;
2750 zonelist
= &pgdat
->node_zonelists
[0];
2751 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
2753 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2755 zonelist
->_zonerefs
[j
].zone
= NULL
;
2756 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2760 * Build gfp_thisnode zonelists
2762 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
2765 struct zonelist
*zonelist
;
2767 zonelist
= &pgdat
->node_zonelists
[1];
2768 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
2769 zonelist
->_zonerefs
[j
].zone
= NULL
;
2770 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2774 * Build zonelists ordered by zone and nodes within zones.
2775 * This results in conserving DMA zone[s] until all Normal memory is
2776 * exhausted, but results in overflowing to remote node while memory
2777 * may still exist in local DMA zone.
2779 static int node_order
[MAX_NUMNODES
];
2781 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
2784 int zone_type
; /* needs to be signed */
2786 struct zonelist
*zonelist
;
2788 zonelist
= &pgdat
->node_zonelists
[0];
2790 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
2791 for (j
= 0; j
< nr_nodes
; j
++) {
2792 node
= node_order
[j
];
2793 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
2794 if (populated_zone(z
)) {
2796 &zonelist
->_zonerefs
[pos
++]);
2797 check_highest_zone(zone_type
);
2801 zonelist
->_zonerefs
[pos
].zone
= NULL
;
2802 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
2805 static int default_zonelist_order(void)
2808 unsigned long low_kmem_size
,total_size
;
2812 * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
2813 * If they are really small and used heavily, the system can fall
2814 * into OOM very easily.
2815 * This function detect ZONE_DMA/DMA32 size and configures zone order.
2817 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
2820 for_each_online_node(nid
) {
2821 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2822 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2823 if (populated_zone(z
)) {
2824 if (zone_type
< ZONE_NORMAL
)
2825 low_kmem_size
+= z
->present_pages
;
2826 total_size
+= z
->present_pages
;
2827 } else if (zone_type
== ZONE_NORMAL
) {
2829 * If any node has only lowmem, then node order
2830 * is preferred to allow kernel allocations
2831 * locally; otherwise, they can easily infringe
2832 * on other nodes when there is an abundance of
2833 * lowmem available to allocate from.
2835 return ZONELIST_ORDER_NODE
;
2839 if (!low_kmem_size
|| /* there are no DMA area. */
2840 low_kmem_size
> total_size
/2) /* DMA/DMA32 is big. */
2841 return ZONELIST_ORDER_NODE
;
2843 * look into each node's config.
2844 * If there is a node whose DMA/DMA32 memory is very big area on
2845 * local memory, NODE_ORDER may be suitable.
2847 average_size
= total_size
/
2848 (nodes_weight(node_states
[N_HIGH_MEMORY
]) + 1);
2849 for_each_online_node(nid
) {
2852 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
2853 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
2854 if (populated_zone(z
)) {
2855 if (zone_type
< ZONE_NORMAL
)
2856 low_kmem_size
+= z
->present_pages
;
2857 total_size
+= z
->present_pages
;
2860 if (low_kmem_size
&&
2861 total_size
> average_size
&& /* ignore small node */
2862 low_kmem_size
> total_size
* 70/100)
2863 return ZONELIST_ORDER_NODE
;
2865 return ZONELIST_ORDER_ZONE
;
2868 static void set_zonelist_order(void)
2870 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
2871 current_zonelist_order
= default_zonelist_order();
2873 current_zonelist_order
= user_zonelist_order
;
2876 static void build_zonelists(pg_data_t
*pgdat
)
2880 nodemask_t used_mask
;
2881 int local_node
, prev_node
;
2882 struct zonelist
*zonelist
;
2883 int order
= current_zonelist_order
;
2885 /* initialize zonelists */
2886 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
2887 zonelist
= pgdat
->node_zonelists
+ i
;
2888 zonelist
->_zonerefs
[0].zone
= NULL
;
2889 zonelist
->_zonerefs
[0].zone_idx
= 0;
2892 /* NUMA-aware ordering of nodes */
2893 local_node
= pgdat
->node_id
;
2894 load
= nr_online_nodes
;
2895 prev_node
= local_node
;
2896 nodes_clear(used_mask
);
2898 memset(node_order
, 0, sizeof(node_order
));
2901 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
2902 int distance
= node_distance(local_node
, node
);
2905 * If another node is sufficiently far away then it is better
2906 * to reclaim pages in a zone before going off node.
2908 if (distance
> RECLAIM_DISTANCE
)
2909 zone_reclaim_mode
= 1;
2912 * We don't want to pressure a particular node.
2913 * So adding penalty to the first node in same
2914 * distance group to make it round-robin.
2916 if (distance
!= node_distance(local_node
, prev_node
))
2917 node_load
[node
] = load
;
2921 if (order
== ZONELIST_ORDER_NODE
)
2922 build_zonelists_in_node_order(pgdat
, node
);
2924 node_order
[j
++] = node
; /* remember order */
2927 if (order
== ZONELIST_ORDER_ZONE
) {
2928 /* calculate node order -- i.e., DMA last! */
2929 build_zonelists_in_zone_order(pgdat
, j
);
2932 build_thisnode_zonelists(pgdat
);
2935 /* Construct the zonelist performance cache - see further mmzone.h */
2936 static void build_zonelist_cache(pg_data_t
*pgdat
)
2938 struct zonelist
*zonelist
;
2939 struct zonelist_cache
*zlc
;
2942 zonelist
= &pgdat
->node_zonelists
[0];
2943 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
2944 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
2945 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
2946 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
2949 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
2951 * Return node id of node used for "local" allocations.
2952 * I.e., first node id of first zone in arg node's generic zonelist.
2953 * Used for initializing percpu 'numa_mem', which is used primarily
2954 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
2956 int local_memory_node(int node
)
2960 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
2961 gfp_zone(GFP_KERNEL
),
2968 #else /* CONFIG_NUMA */
2970 static void set_zonelist_order(void)
2972 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
2975 static void build_zonelists(pg_data_t
*pgdat
)
2977 int node
, local_node
;
2979 struct zonelist
*zonelist
;
2981 local_node
= pgdat
->node_id
;
2983 zonelist
= &pgdat
->node_zonelists
[0];
2984 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
2987 * Now we build the zonelist so that it contains the zones
2988 * of all the other nodes.
2989 * We don't want to pressure a particular node, so when
2990 * building the zones for node N, we make sure that the
2991 * zones coming right after the local ones are those from
2992 * node N+1 (modulo N)
2994 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
2995 if (!node_online(node
))
2997 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3000 for (node
= 0; node
< local_node
; node
++) {
3001 if (!node_online(node
))
3003 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3007 zonelist
->_zonerefs
[j
].zone
= NULL
;
3008 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3011 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3012 static void build_zonelist_cache(pg_data_t
*pgdat
)
3014 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
3017 #endif /* CONFIG_NUMA */
3020 * Boot pageset table. One per cpu which is going to be used for all
3021 * zones and all nodes. The parameters will be set in such a way
3022 * that an item put on a list will immediately be handed over to
3023 * the buddy list. This is safe since pageset manipulation is done
3024 * with interrupts disabled.
3026 * The boot_pagesets must be kept even after bootup is complete for
3027 * unused processors and/or zones. They do play a role for bootstrapping
3028 * hotplugged processors.
3030 * zoneinfo_show() and maybe other functions do
3031 * not check if the processor is online before following the pageset pointer.
3032 * Other parts of the kernel may not check if the zone is available.
3034 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
3035 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
3036 static void setup_zone_pageset(struct zone
*zone
);
3039 * Global mutex to protect against size modification of zonelists
3040 * as well as to serialize pageset setup for the new populated zone.
3042 DEFINE_MUTEX(zonelists_mutex
);
3044 /* return values int ....just for stop_machine() */
3045 static __init_refok
int __build_all_zonelists(void *data
)
3051 memset(node_load
, 0, sizeof(node_load
));
3053 for_each_online_node(nid
) {
3054 pg_data_t
*pgdat
= NODE_DATA(nid
);
3056 build_zonelists(pgdat
);
3057 build_zonelist_cache(pgdat
);
3061 * Initialize the boot_pagesets that are going to be used
3062 * for bootstrapping processors. The real pagesets for
3063 * each zone will be allocated later when the per cpu
3064 * allocator is available.
3066 * boot_pagesets are used also for bootstrapping offline
3067 * cpus if the system is already booted because the pagesets
3068 * are needed to initialize allocators on a specific cpu too.
3069 * F.e. the percpu allocator needs the page allocator which
3070 * needs the percpu allocator in order to allocate its pagesets
3071 * (a chicken-egg dilemma).
3073 for_each_possible_cpu(cpu
) {
3074 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
3076 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3078 * We now know the "local memory node" for each node--
3079 * i.e., the node of the first zone in the generic zonelist.
3080 * Set up numa_mem percpu variable for on-line cpus. During
3081 * boot, only the boot cpu should be on-line; we'll init the
3082 * secondary cpus' numa_mem as they come on-line. During
3083 * node/memory hotplug, we'll fixup all on-line cpus.
3085 if (cpu_online(cpu
))
3086 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
3094 * Called with zonelists_mutex held always
3095 * unless system_state == SYSTEM_BOOTING.
3097 void build_all_zonelists(void *data
)
3099 set_zonelist_order();
3101 if (system_state
== SYSTEM_BOOTING
) {
3102 __build_all_zonelists(NULL
);
3103 mminit_verify_zonelist();
3104 cpuset_init_current_mems_allowed();
3106 /* we have to stop all cpus to guarantee there is no user
3108 #ifdef CONFIG_MEMORY_HOTPLUG
3110 setup_zone_pageset((struct zone
*)data
);
3112 stop_machine(__build_all_zonelists
, NULL
, NULL
);
3113 /* cpuset refresh routine should be here */
3115 vm_total_pages
= nr_free_pagecache_pages();
3117 * Disable grouping by mobility if the number of pages in the
3118 * system is too low to allow the mechanism to work. It would be
3119 * more accurate, but expensive to check per-zone. This check is
3120 * made on memory-hotadd so a system can start with mobility
3121 * disabled and enable it later
3123 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
3124 page_group_by_mobility_disabled
= 1;
3126 page_group_by_mobility_disabled
= 0;
3128 printk("Built %i zonelists in %s order, mobility grouping %s. "
3129 "Total pages: %ld\n",
3131 zonelist_order_name
[current_zonelist_order
],
3132 page_group_by_mobility_disabled
? "off" : "on",
3135 printk("Policy zone: %s\n", zone_names
[policy_zone
]);
3140 * Helper functions to size the waitqueue hash table.
3141 * Essentially these want to choose hash table sizes sufficiently
3142 * large so that collisions trying to wait on pages are rare.
3143 * But in fact, the number of active page waitqueues on typical
3144 * systems is ridiculously low, less than 200. So this is even
3145 * conservative, even though it seems large.
3147 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3148 * waitqueues, i.e. the size of the waitq table given the number of pages.
3150 #define PAGES_PER_WAITQUEUE 256
3152 #ifndef CONFIG_MEMORY_HOTPLUG
3153 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3155 unsigned long size
= 1;
3157 pages
/= PAGES_PER_WAITQUEUE
;
3159 while (size
< pages
)
3163 * Once we have dozens or even hundreds of threads sleeping
3164 * on IO we've got bigger problems than wait queue collision.
3165 * Limit the size of the wait table to a reasonable size.
3167 size
= min(size
, 4096UL);
3169 return max(size
, 4UL);
3173 * A zone's size might be changed by hot-add, so it is not possible to determine
3174 * a suitable size for its wait_table. So we use the maximum size now.
3176 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
3178 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
3179 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3180 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
3182 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3183 * or more by the traditional way. (See above). It equals:
3185 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
3186 * ia64(16K page size) : = ( 8G + 4M)byte.
3187 * powerpc (64K page size) : = (32G +16M)byte.
3189 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3196 * This is an integer logarithm so that shifts can be used later
3197 * to extract the more random high bits from the multiplicative
3198 * hash function before the remainder is taken.
3200 static inline unsigned long wait_table_bits(unsigned long size
)
3205 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
3208 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3209 * of blocks reserved is based on min_wmark_pages(zone). The memory within
3210 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3211 * higher will lead to a bigger reserve which will get freed as contiguous
3212 * blocks as reclaim kicks in
3214 static void setup_zone_migrate_reserve(struct zone
*zone
)
3216 unsigned long start_pfn
, pfn
, end_pfn
;
3218 unsigned long block_migratetype
;
3221 /* Get the start pfn, end pfn and the number of blocks to reserve */
3222 start_pfn
= zone
->zone_start_pfn
;
3223 end_pfn
= start_pfn
+ zone
->spanned_pages
;
3224 reserve
= roundup(min_wmark_pages(zone
), pageblock_nr_pages
) >>
3228 * Reserve blocks are generally in place to help high-order atomic
3229 * allocations that are short-lived. A min_free_kbytes value that
3230 * would result in more than 2 reserve blocks for atomic allocations
3231 * is assumed to be in place to help anti-fragmentation for the
3232 * future allocation of hugepages at runtime.
3234 reserve
= min(2, reserve
);
3236 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
3237 if (!pfn_valid(pfn
))
3239 page
= pfn_to_page(pfn
);
3241 /* Watch out for overlapping nodes */
3242 if (page_to_nid(page
) != zone_to_nid(zone
))
3245 /* Blocks with reserved pages will never free, skip them. */
3246 if (PageReserved(page
))
3249 block_migratetype
= get_pageblock_migratetype(page
);
3251 /* If this block is reserved, account for it */
3252 if (reserve
> 0 && block_migratetype
== MIGRATE_RESERVE
) {
3257 /* Suitable for reserving if this block is movable */
3258 if (reserve
> 0 && block_migratetype
== MIGRATE_MOVABLE
) {
3259 set_pageblock_migratetype(page
, MIGRATE_RESERVE
);
3260 move_freepages_block(zone
, page
, MIGRATE_RESERVE
);
3266 * If the reserve is met and this is a previous reserved block,
3269 if (block_migratetype
== MIGRATE_RESERVE
) {
3270 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3271 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
3277 * Initially all pages are reserved - free ones are freed
3278 * up by free_all_bootmem() once the early boot process is
3279 * done. Non-atomic initialization, single-pass.
3281 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
3282 unsigned long start_pfn
, enum memmap_context context
)
3285 unsigned long end_pfn
= start_pfn
+ size
;
3289 if (highest_memmap_pfn
< end_pfn
- 1)
3290 highest_memmap_pfn
= end_pfn
- 1;
3292 z
= &NODE_DATA(nid
)->node_zones
[zone
];
3293 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
3295 * There can be holes in boot-time mem_map[]s
3296 * handed to this function. They do not
3297 * exist on hotplugged memory.
3299 if (context
== MEMMAP_EARLY
) {
3300 if (!early_pfn_valid(pfn
))
3302 if (!early_pfn_in_nid(pfn
, nid
))
3305 page
= pfn_to_page(pfn
);
3306 set_page_links(page
, zone
, nid
, pfn
);
3307 mminit_verify_page_links(page
, zone
, nid
, pfn
);
3308 init_page_count(page
);
3309 reset_page_mapcount(page
);
3310 SetPageReserved(page
);
3312 * Mark the block movable so that blocks are reserved for
3313 * movable at startup. This will force kernel allocations
3314 * to reserve their blocks rather than leaking throughout
3315 * the address space during boot when many long-lived
3316 * kernel allocations are made. Later some blocks near
3317 * the start are marked MIGRATE_RESERVE by
3318 * setup_zone_migrate_reserve()
3320 * bitmap is created for zone's valid pfn range. but memmap
3321 * can be created for invalid pages (for alignment)
3322 * check here not to call set_pageblock_migratetype() against
3325 if ((z
->zone_start_pfn
<= pfn
)
3326 && (pfn
< z
->zone_start_pfn
+ z
->spanned_pages
)
3327 && !(pfn
& (pageblock_nr_pages
- 1)))
3328 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3330 INIT_LIST_HEAD(&page
->lru
);
3331 #ifdef WANT_PAGE_VIRTUAL
3332 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
3333 if (!is_highmem_idx(zone
))
3334 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
3339 static void __meminit
zone_init_free_lists(struct zone
*zone
)
3342 for_each_migratetype_order(order
, t
) {
3343 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
3344 zone
->free_area
[order
].nr_free
= 0;
3348 #ifndef __HAVE_ARCH_MEMMAP_INIT
3349 #define memmap_init(size, nid, zone, start_pfn) \
3350 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
3353 static int zone_batchsize(struct zone
*zone
)
3359 * The per-cpu-pages pools are set to around 1000th of the
3360 * size of the zone. But no more than 1/2 of a meg.
3362 * OK, so we don't know how big the cache is. So guess.
3364 batch
= zone
->present_pages
/ 1024;
3365 if (batch
* PAGE_SIZE
> 512 * 1024)
3366 batch
= (512 * 1024) / PAGE_SIZE
;
3367 batch
/= 4; /* We effectively *= 4 below */
3372 * Clamp the batch to a 2^n - 1 value. Having a power
3373 * of 2 value was found to be more likely to have
3374 * suboptimal cache aliasing properties in some cases.
3376 * For example if 2 tasks are alternately allocating
3377 * batches of pages, one task can end up with a lot
3378 * of pages of one half of the possible page colors
3379 * and the other with pages of the other colors.
3381 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
3386 /* The deferral and batching of frees should be suppressed under NOMMU
3389 * The problem is that NOMMU needs to be able to allocate large chunks
3390 * of contiguous memory as there's no hardware page translation to
3391 * assemble apparent contiguous memory from discontiguous pages.
3393 * Queueing large contiguous runs of pages for batching, however,
3394 * causes the pages to actually be freed in smaller chunks. As there
3395 * can be a significant delay between the individual batches being
3396 * recycled, this leads to the once large chunks of space being
3397 * fragmented and becoming unavailable for high-order allocations.
3403 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
3405 struct per_cpu_pages
*pcp
;
3408 memset(p
, 0, sizeof(*p
));
3412 pcp
->high
= 6 * batch
;
3413 pcp
->batch
= max(1UL, 1 * batch
);
3414 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
3415 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
3419 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
3420 * to the value high for the pageset p.
3423 static void setup_pagelist_highmark(struct per_cpu_pageset
*p
,
3426 struct per_cpu_pages
*pcp
;
3430 pcp
->batch
= max(1UL, high
/4);
3431 if ((high
/4) > (PAGE_SHIFT
* 8))
3432 pcp
->batch
= PAGE_SHIFT
* 8;
3435 static __meminit
void setup_zone_pageset(struct zone
*zone
)
3439 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
3441 for_each_possible_cpu(cpu
) {
3442 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
3444 setup_pageset(pcp
, zone_batchsize(zone
));
3446 if (percpu_pagelist_fraction
)
3447 setup_pagelist_highmark(pcp
,
3448 (zone
->present_pages
/
3449 percpu_pagelist_fraction
));
3454 * Allocate per cpu pagesets and initialize them.
3455 * Before this call only boot pagesets were available.
3457 void __init
setup_per_cpu_pageset(void)
3461 for_each_populated_zone(zone
)
3462 setup_zone_pageset(zone
);
3465 static noinline __init_refok
3466 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
3469 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
3473 * The per-page waitqueue mechanism uses hashed waitqueues
3476 zone
->wait_table_hash_nr_entries
=
3477 wait_table_hash_nr_entries(zone_size_pages
);
3478 zone
->wait_table_bits
=
3479 wait_table_bits(zone
->wait_table_hash_nr_entries
);
3480 alloc_size
= zone
->wait_table_hash_nr_entries
3481 * sizeof(wait_queue_head_t
);
3483 if (!slab_is_available()) {
3484 zone
->wait_table
= (wait_queue_head_t
*)
3485 alloc_bootmem_node(pgdat
, alloc_size
);
3488 * This case means that a zone whose size was 0 gets new memory
3489 * via memory hot-add.
3490 * But it may be the case that a new node was hot-added. In
3491 * this case vmalloc() will not be able to use this new node's
3492 * memory - this wait_table must be initialized to use this new
3493 * node itself as well.
3494 * To use this new node's memory, further consideration will be
3497 zone
->wait_table
= vmalloc(alloc_size
);
3499 if (!zone
->wait_table
)
3502 for(i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
3503 init_waitqueue_head(zone
->wait_table
+ i
);
3508 static int __zone_pcp_update(void *data
)
3510 struct zone
*zone
= data
;
3512 unsigned long batch
= zone_batchsize(zone
), flags
;
3514 for_each_possible_cpu(cpu
) {
3515 struct per_cpu_pageset
*pset
;
3516 struct per_cpu_pages
*pcp
;
3518 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
3521 local_irq_save(flags
);
3522 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
3523 setup_pageset(pset
, batch
);
3524 local_irq_restore(flags
);
3529 void zone_pcp_update(struct zone
*zone
)
3531 stop_machine(__zone_pcp_update
, zone
, NULL
);
3534 static __meminit
void zone_pcp_init(struct zone
*zone
)
3537 * per cpu subsystem is not up at this point. The following code
3538 * relies on the ability of the linker to provide the
3539 * offset of a (static) per cpu variable into the per cpu area.
3541 zone
->pageset
= &boot_pageset
;
3543 if (zone
->present_pages
)
3544 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
3545 zone
->name
, zone
->present_pages
,
3546 zone_batchsize(zone
));
3549 __meminit
int init_currently_empty_zone(struct zone
*zone
,
3550 unsigned long zone_start_pfn
,
3552 enum memmap_context context
)
3554 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
3556 ret
= zone_wait_table_init(zone
, size
);
3559 pgdat
->nr_zones
= zone_idx(zone
) + 1;
3561 zone
->zone_start_pfn
= zone_start_pfn
;
3563 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
3564 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
3566 (unsigned long)zone_idx(zone
),
3567 zone_start_pfn
, (zone_start_pfn
+ size
));
3569 zone_init_free_lists(zone
);
3574 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3576 * Basic iterator support. Return the first range of PFNs for a node
3577 * Note: nid == MAX_NUMNODES returns first region regardless of node
3579 static int __meminit
first_active_region_index_in_nid(int nid
)
3583 for (i
= 0; i
< nr_nodemap_entries
; i
++)
3584 if (nid
== MAX_NUMNODES
|| early_node_map
[i
].nid
== nid
)
3591 * Basic iterator support. Return the next active range of PFNs for a node
3592 * Note: nid == MAX_NUMNODES returns next region regardless of node
3594 static int __meminit
next_active_region_index_in_nid(int index
, int nid
)
3596 for (index
= index
+ 1; index
< nr_nodemap_entries
; index
++)
3597 if (nid
== MAX_NUMNODES
|| early_node_map
[index
].nid
== nid
)
3603 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
3605 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
3606 * Architectures may implement their own version but if add_active_range()
3607 * was used and there are no special requirements, this is a convenient
3610 int __meminit
__early_pfn_to_nid(unsigned long pfn
)
3614 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
3615 unsigned long start_pfn
= early_node_map
[i
].start_pfn
;
3616 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
3618 if (start_pfn
<= pfn
&& pfn
< end_pfn
)
3619 return early_node_map
[i
].nid
;
3621 /* This is a memory hole */
3624 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
3626 int __meminit
early_pfn_to_nid(unsigned long pfn
)
3630 nid
= __early_pfn_to_nid(pfn
);
3633 /* just returns 0 */
3637 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
3638 bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
3642 nid
= __early_pfn_to_nid(pfn
);
3643 if (nid
>= 0 && nid
!= node
)
3649 /* Basic iterator support to walk early_node_map[] */
3650 #define for_each_active_range_index_in_nid(i, nid) \
3651 for (i = first_active_region_index_in_nid(nid); i != -1; \
3652 i = next_active_region_index_in_nid(i, nid))
3655 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
3656 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
3657 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
3659 * If an architecture guarantees that all ranges registered with
3660 * add_active_ranges() contain no holes and may be freed, this
3661 * this function may be used instead of calling free_bootmem() manually.
3663 void __init
free_bootmem_with_active_regions(int nid
,
3664 unsigned long max_low_pfn
)
3668 for_each_active_range_index_in_nid(i
, nid
) {
3669 unsigned long size_pages
= 0;
3670 unsigned long end_pfn
= early_node_map
[i
].end_pfn
;
3672 if (early_node_map
[i
].start_pfn
>= max_low_pfn
)
3675 if (end_pfn
> max_low_pfn
)
3676 end_pfn
= max_low_pfn
;
3678 size_pages
= end_pfn
- early_node_map
[i
].start_pfn
;
3679 free_bootmem_node(NODE_DATA(early_node_map
[i
].nid
),
3680 PFN_PHYS(early_node_map
[i
].start_pfn
),
3681 size_pages
<< PAGE_SHIFT
);
3685 #ifdef CONFIG_HAVE_MEMBLOCK
3686 u64 __init
find_memory_core_early(int nid
, u64 size
, u64 align
,
3687 u64 goal
, u64 limit
)
3691 /* Need to go over early_node_map to find out good range for node */
3692 for_each_active_range_index_in_nid(i
, nid
) {
3694 u64 ei_start
, ei_last
;
3695 u64 final_start
, final_end
;
3697 ei_last
= early_node_map
[i
].end_pfn
;
3698 ei_last
<<= PAGE_SHIFT
;
3699 ei_start
= early_node_map
[i
].start_pfn
;
3700 ei_start
<<= PAGE_SHIFT
;
3702 final_start
= max(ei_start
, goal
);
3703 final_end
= min(ei_last
, limit
);
3705 if (final_start
>= final_end
)
3708 addr
= memblock_find_in_range(final_start
, final_end
, size
, align
);
3710 if (addr
== MEMBLOCK_ERROR
)
3716 return MEMBLOCK_ERROR
;
3720 int __init
add_from_early_node_map(struct range
*range
, int az
,
3721 int nr_range
, int nid
)
3726 /* need to go over early_node_map to find out good range for node */
3727 for_each_active_range_index_in_nid(i
, nid
) {
3728 start
= early_node_map
[i
].start_pfn
;
3729 end
= early_node_map
[i
].end_pfn
;
3730 nr_range
= add_range(range
, az
, nr_range
, start
, end
);
3735 #ifdef CONFIG_NO_BOOTMEM
3736 void * __init
__alloc_memory_core_early(int nid
, u64 size
, u64 align
,
3737 u64 goal
, u64 limit
)
3742 if (limit
> memblock
.current_limit
)
3743 limit
= memblock
.current_limit
;
3745 addr
= find_memory_core_early(nid
, size
, align
, goal
, limit
);
3747 if (addr
== MEMBLOCK_ERROR
)
3750 ptr
= phys_to_virt(addr
);
3751 memset(ptr
, 0, size
);
3752 memblock_x86_reserve_range(addr
, addr
+ size
, "BOOTMEM");
3754 * The min_count is set to 0 so that bootmem allocated blocks
3755 * are never reported as leaks.
3757 kmemleak_alloc(ptr
, size
, 0, 0);
3763 void __init
work_with_active_regions(int nid
, work_fn_t work_fn
, void *data
)
3768 for_each_active_range_index_in_nid(i
, nid
) {
3769 ret
= work_fn(early_node_map
[i
].start_pfn
,
3770 early_node_map
[i
].end_pfn
, data
);
3776 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3777 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3779 * If an architecture guarantees that all ranges registered with
3780 * add_active_ranges() contain no holes and may be freed, this
3781 * function may be used instead of calling memory_present() manually.
3783 void __init
sparse_memory_present_with_active_regions(int nid
)
3787 for_each_active_range_index_in_nid(i
, nid
)
3788 memory_present(early_node_map
[i
].nid
,
3789 early_node_map
[i
].start_pfn
,
3790 early_node_map
[i
].end_pfn
);
3794 * get_pfn_range_for_nid - Return the start and end page frames for a node
3795 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
3796 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
3797 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
3799 * It returns the start and end page frame of a node based on information
3800 * provided by an arch calling add_active_range(). If called for a node
3801 * with no available memory, a warning is printed and the start and end
3804 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
3805 unsigned long *start_pfn
, unsigned long *end_pfn
)
3811 for_each_active_range_index_in_nid(i
, nid
) {
3812 *start_pfn
= min(*start_pfn
, early_node_map
[i
].start_pfn
);
3813 *end_pfn
= max(*end_pfn
, early_node_map
[i
].end_pfn
);
3816 if (*start_pfn
== -1UL)
3821 * This finds a zone that can be used for ZONE_MOVABLE pages. The
3822 * assumption is made that zones within a node are ordered in monotonic
3823 * increasing memory addresses so that the "highest" populated zone is used
3825 static void __init
find_usable_zone_for_movable(void)
3828 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
3829 if (zone_index
== ZONE_MOVABLE
)
3832 if (arch_zone_highest_possible_pfn
[zone_index
] >
3833 arch_zone_lowest_possible_pfn
[zone_index
])
3837 VM_BUG_ON(zone_index
== -1);
3838 movable_zone
= zone_index
;
3842 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
3843 * because it is sized independant of architecture. Unlike the other zones,
3844 * the starting point for ZONE_MOVABLE is not fixed. It may be different
3845 * in each node depending on the size of each node and how evenly kernelcore
3846 * is distributed. This helper function adjusts the zone ranges
3847 * provided by the architecture for a given node by using the end of the
3848 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
3849 * zones within a node are in order of monotonic increases memory addresses
3851 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
3852 unsigned long zone_type
,
3853 unsigned long node_start_pfn
,
3854 unsigned long node_end_pfn
,
3855 unsigned long *zone_start_pfn
,
3856 unsigned long *zone_end_pfn
)
3858 /* Only adjust if ZONE_MOVABLE is on this node */
3859 if (zone_movable_pfn
[nid
]) {
3860 /* Size ZONE_MOVABLE */
3861 if (zone_type
== ZONE_MOVABLE
) {
3862 *zone_start_pfn
= zone_movable_pfn
[nid
];
3863 *zone_end_pfn
= min(node_end_pfn
,
3864 arch_zone_highest_possible_pfn
[movable_zone
]);
3866 /* Adjust for ZONE_MOVABLE starting within this range */
3867 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
3868 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
3869 *zone_end_pfn
= zone_movable_pfn
[nid
];
3871 /* Check if this whole range is within ZONE_MOVABLE */
3872 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
3873 *zone_start_pfn
= *zone_end_pfn
;
3878 * Return the number of pages a zone spans in a node, including holes
3879 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
3881 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3882 unsigned long zone_type
,
3883 unsigned long *ignored
)
3885 unsigned long node_start_pfn
, node_end_pfn
;
3886 unsigned long zone_start_pfn
, zone_end_pfn
;
3888 /* Get the start and end of the node and zone */
3889 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3890 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
3891 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
3892 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3893 node_start_pfn
, node_end_pfn
,
3894 &zone_start_pfn
, &zone_end_pfn
);
3896 /* Check that this node has pages within the zone's required range */
3897 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
3900 /* Move the zone boundaries inside the node if necessary */
3901 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
3902 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
3904 /* Return the spanned pages */
3905 return zone_end_pfn
- zone_start_pfn
;
3909 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
3910 * then all holes in the requested range will be accounted for.
3912 unsigned long __meminit
__absent_pages_in_range(int nid
,
3913 unsigned long range_start_pfn
,
3914 unsigned long range_end_pfn
)
3917 unsigned long prev_end_pfn
= 0, hole_pages
= 0;
3918 unsigned long start_pfn
;
3920 /* Find the end_pfn of the first active range of pfns in the node */
3921 i
= first_active_region_index_in_nid(nid
);
3925 prev_end_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3927 /* Account for ranges before physical memory on this node */
3928 if (early_node_map
[i
].start_pfn
> range_start_pfn
)
3929 hole_pages
= prev_end_pfn
- range_start_pfn
;
3931 /* Find all holes for the zone within the node */
3932 for (; i
!= -1; i
= next_active_region_index_in_nid(i
, nid
)) {
3934 /* No need to continue if prev_end_pfn is outside the zone */
3935 if (prev_end_pfn
>= range_end_pfn
)
3938 /* Make sure the end of the zone is not within the hole */
3939 start_pfn
= min(early_node_map
[i
].start_pfn
, range_end_pfn
);
3940 prev_end_pfn
= max(prev_end_pfn
, range_start_pfn
);
3942 /* Update the hole size cound and move on */
3943 if (start_pfn
> range_start_pfn
) {
3944 BUG_ON(prev_end_pfn
> start_pfn
);
3945 hole_pages
+= start_pfn
- prev_end_pfn
;
3947 prev_end_pfn
= early_node_map
[i
].end_pfn
;
3950 /* Account for ranges past physical memory on this node */
3951 if (range_end_pfn
> prev_end_pfn
)
3952 hole_pages
+= range_end_pfn
-
3953 max(range_start_pfn
, prev_end_pfn
);
3959 * absent_pages_in_range - Return number of page frames in holes within a range
3960 * @start_pfn: The start PFN to start searching for holes
3961 * @end_pfn: The end PFN to stop searching for holes
3963 * It returns the number of pages frames in memory holes within a range.
3965 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
3966 unsigned long end_pfn
)
3968 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
3971 /* Return the number of page frames in holes in a zone on a node */
3972 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
3973 unsigned long zone_type
,
3974 unsigned long *ignored
)
3976 unsigned long node_start_pfn
, node_end_pfn
;
3977 unsigned long zone_start_pfn
, zone_end_pfn
;
3979 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
3980 zone_start_pfn
= max(arch_zone_lowest_possible_pfn
[zone_type
],
3982 zone_end_pfn
= min(arch_zone_highest_possible_pfn
[zone_type
],
3985 adjust_zone_range_for_zone_movable(nid
, zone_type
,
3986 node_start_pfn
, node_end_pfn
,
3987 &zone_start_pfn
, &zone_end_pfn
);
3988 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
3992 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3993 unsigned long zone_type
,
3994 unsigned long *zones_size
)
3996 return zones_size
[zone_type
];
3999 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4000 unsigned long zone_type
,
4001 unsigned long *zholes_size
)
4006 return zholes_size
[zone_type
];
4011 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
4012 unsigned long *zones_size
, unsigned long *zholes_size
)
4014 unsigned long realtotalpages
, totalpages
= 0;
4017 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4018 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
4020 pgdat
->node_spanned_pages
= totalpages
;
4022 realtotalpages
= totalpages
;
4023 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4025 zone_absent_pages_in_node(pgdat
->node_id
, i
,
4027 pgdat
->node_present_pages
= realtotalpages
;
4028 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
4032 #ifndef CONFIG_SPARSEMEM
4034 * Calculate the size of the zone->blockflags rounded to an unsigned long
4035 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4036 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4037 * round what is now in bits to nearest long in bits, then return it in
4040 static unsigned long __init
usemap_size(unsigned long zonesize
)
4042 unsigned long usemapsize
;
4044 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
4045 usemapsize
= usemapsize
>> pageblock_order
;
4046 usemapsize
*= NR_PAGEBLOCK_BITS
;
4047 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
4049 return usemapsize
/ 8;
4052 static void __init
setup_usemap(struct pglist_data
*pgdat
,
4053 struct zone
*zone
, unsigned long zonesize
)
4055 unsigned long usemapsize
= usemap_size(zonesize
);
4056 zone
->pageblock_flags
= NULL
;
4058 zone
->pageblock_flags
= alloc_bootmem_node(pgdat
, usemapsize
);
4061 static inline void setup_usemap(struct pglist_data
*pgdat
,
4062 struct zone
*zone
, unsigned long zonesize
) {}
4063 #endif /* CONFIG_SPARSEMEM */
4065 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4067 /* Return a sensible default order for the pageblock size. */
4068 static inline int pageblock_default_order(void)
4070 if (HPAGE_SHIFT
> PAGE_SHIFT
)
4071 return HUGETLB_PAGE_ORDER
;
4076 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4077 static inline void __init
set_pageblock_order(unsigned int order
)
4079 /* Check that pageblock_nr_pages has not already been setup */
4080 if (pageblock_order
)
4084 * Assume the largest contiguous order of interest is a huge page.
4085 * This value may be variable depending on boot parameters on IA64
4087 pageblock_order
= order
;
4089 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4092 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4093 * and pageblock_default_order() are unused as pageblock_order is set
4094 * at compile-time. See include/linux/pageblock-flags.h for the values of
4095 * pageblock_order based on the kernel config
4097 static inline int pageblock_default_order(unsigned int order
)
4101 #define set_pageblock_order(x) do {} while (0)
4103 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4106 * Set up the zone data structures:
4107 * - mark all pages reserved
4108 * - mark all memory queues empty
4109 * - clear the memory bitmaps
4111 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
,
4112 unsigned long *zones_size
, unsigned long *zholes_size
)
4115 int nid
= pgdat
->node_id
;
4116 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
4119 pgdat_resize_init(pgdat
);
4120 pgdat
->nr_zones
= 0;
4121 init_waitqueue_head(&pgdat
->kswapd_wait
);
4122 pgdat
->kswapd_max_order
= 0;
4123 pgdat_page_cgroup_init(pgdat
);
4125 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4126 struct zone
*zone
= pgdat
->node_zones
+ j
;
4127 unsigned long size
, realsize
, memmap_pages
;
4130 size
= zone_spanned_pages_in_node(nid
, j
, zones_size
);
4131 realsize
= size
- zone_absent_pages_in_node(nid
, j
,
4135 * Adjust realsize so that it accounts for how much memory
4136 * is used by this zone for memmap. This affects the watermark
4137 * and per-cpu initialisations
4140 PAGE_ALIGN(size
* sizeof(struct page
)) >> PAGE_SHIFT
;
4141 if (realsize
>= memmap_pages
) {
4142 realsize
-= memmap_pages
;
4145 " %s zone: %lu pages used for memmap\n",
4146 zone_names
[j
], memmap_pages
);
4149 " %s zone: %lu pages exceeds realsize %lu\n",
4150 zone_names
[j
], memmap_pages
, realsize
);
4152 /* Account for reserved pages */
4153 if (j
== 0 && realsize
> dma_reserve
) {
4154 realsize
-= dma_reserve
;
4155 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
4156 zone_names
[0], dma_reserve
);
4159 if (!is_highmem_idx(j
))
4160 nr_kernel_pages
+= realsize
;
4161 nr_all_pages
+= realsize
;
4163 zone
->spanned_pages
= size
;
4164 zone
->present_pages
= realsize
;
4167 zone
->min_unmapped_pages
= (realsize
*sysctl_min_unmapped_ratio
)
4169 zone
->min_slab_pages
= (realsize
* sysctl_min_slab_ratio
) / 100;
4171 zone
->name
= zone_names
[j
];
4172 spin_lock_init(&zone
->lock
);
4173 spin_lock_init(&zone
->lru_lock
);
4174 zone_seqlock_init(zone
);
4175 zone
->zone_pgdat
= pgdat
;
4177 zone_pcp_init(zone
);
4179 INIT_LIST_HEAD(&zone
->lru
[l
].list
);
4180 zone
->reclaim_stat
.nr_saved_scan
[l
] = 0;
4182 zone
->reclaim_stat
.recent_rotated
[0] = 0;
4183 zone
->reclaim_stat
.recent_rotated
[1] = 0;
4184 zone
->reclaim_stat
.recent_scanned
[0] = 0;
4185 zone
->reclaim_stat
.recent_scanned
[1] = 0;
4186 zap_zone_vm_stats(zone
);
4191 set_pageblock_order(pageblock_default_order());
4192 setup_usemap(pgdat
, zone
, size
);
4193 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
4194 size
, MEMMAP_EARLY
);
4196 memmap_init(size
, nid
, j
, zone_start_pfn
);
4197 zone_start_pfn
+= size
;
4201 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
4203 /* Skip empty nodes */
4204 if (!pgdat
->node_spanned_pages
)
4207 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4208 /* ia64 gets its own node_mem_map, before this, without bootmem */
4209 if (!pgdat
->node_mem_map
) {
4210 unsigned long size
, start
, end
;
4214 * The zone's endpoints aren't required to be MAX_ORDER
4215 * aligned but the node_mem_map endpoints must be in order
4216 * for the buddy allocator to function correctly.
4218 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
4219 end
= pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
4220 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
4221 size
= (end
- start
) * sizeof(struct page
);
4222 map
= alloc_remap(pgdat
->node_id
, size
);
4224 map
= alloc_bootmem_node(pgdat
, size
);
4225 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
4227 #ifndef CONFIG_NEED_MULTIPLE_NODES
4229 * With no DISCONTIG, the global mem_map is just set as node 0's
4231 if (pgdat
== NODE_DATA(0)) {
4232 mem_map
= NODE_DATA(0)->node_mem_map
;
4233 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
4234 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
4235 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
4236 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
4239 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4242 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
4243 unsigned long node_start_pfn
, unsigned long *zholes_size
)
4245 pg_data_t
*pgdat
= NODE_DATA(nid
);
4247 pgdat
->node_id
= nid
;
4248 pgdat
->node_start_pfn
= node_start_pfn
;
4249 calculate_node_totalpages(pgdat
, zones_size
, zholes_size
);
4251 alloc_node_mem_map(pgdat
);
4252 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4253 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
4254 nid
, (unsigned long)pgdat
,
4255 (unsigned long)pgdat
->node_mem_map
);
4258 free_area_init_core(pgdat
, zones_size
, zholes_size
);
4261 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
4263 #if MAX_NUMNODES > 1
4265 * Figure out the number of possible node ids.
4267 static void __init
setup_nr_node_ids(void)
4270 unsigned int highest
= 0;
4272 for_each_node_mask(node
, node_possible_map
)
4274 nr_node_ids
= highest
+ 1;
4277 static inline void setup_nr_node_ids(void)
4283 * add_active_range - Register a range of PFNs backed by physical memory
4284 * @nid: The node ID the range resides on
4285 * @start_pfn: The start PFN of the available physical memory
4286 * @end_pfn: The end PFN of the available physical memory
4288 * These ranges are stored in an early_node_map[] and later used by
4289 * free_area_init_nodes() to calculate zone sizes and holes. If the
4290 * range spans a memory hole, it is up to the architecture to ensure
4291 * the memory is not freed by the bootmem allocator. If possible
4292 * the range being registered will be merged with existing ranges.
4294 void __init
add_active_range(unsigned int nid
, unsigned long start_pfn
,
4295 unsigned long end_pfn
)
4299 mminit_dprintk(MMINIT_TRACE
, "memory_register",
4300 "Entering add_active_range(%d, %#lx, %#lx) "
4301 "%d entries of %d used\n",
4302 nid
, start_pfn
, end_pfn
,
4303 nr_nodemap_entries
, MAX_ACTIVE_REGIONS
);
4305 mminit_validate_memmodel_limits(&start_pfn
, &end_pfn
);
4307 /* Merge with existing active regions if possible */
4308 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
4309 if (early_node_map
[i
].nid
!= nid
)
4312 /* Skip if an existing region covers this new one */
4313 if (start_pfn
>= early_node_map
[i
].start_pfn
&&
4314 end_pfn
<= early_node_map
[i
].end_pfn
)
4317 /* Merge forward if suitable */
4318 if (start_pfn
<= early_node_map
[i
].end_pfn
&&
4319 end_pfn
> early_node_map
[i
].end_pfn
) {
4320 early_node_map
[i
].end_pfn
= end_pfn
;
4324 /* Merge backward if suitable */
4325 if (start_pfn
< early_node_map
[i
].start_pfn
&&
4326 end_pfn
>= early_node_map
[i
].start_pfn
) {
4327 early_node_map
[i
].start_pfn
= start_pfn
;
4332 /* Check that early_node_map is large enough */
4333 if (i
>= MAX_ACTIVE_REGIONS
) {
4334 printk(KERN_CRIT
"More than %d memory regions, truncating\n",
4335 MAX_ACTIVE_REGIONS
);
4339 early_node_map
[i
].nid
= nid
;
4340 early_node_map
[i
].start_pfn
= start_pfn
;
4341 early_node_map
[i
].end_pfn
= end_pfn
;
4342 nr_nodemap_entries
= i
+ 1;
4346 * remove_active_range - Shrink an existing registered range of PFNs
4347 * @nid: The node id the range is on that should be shrunk
4348 * @start_pfn: The new PFN of the range
4349 * @end_pfn: The new PFN of the range
4351 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
4352 * The map is kept near the end physical page range that has already been
4353 * registered. This function allows an arch to shrink an existing registered
4356 void __init
remove_active_range(unsigned int nid
, unsigned long start_pfn
,
4357 unsigned long end_pfn
)
4362 printk(KERN_DEBUG
"remove_active_range (%d, %lu, %lu)\n",
4363 nid
, start_pfn
, end_pfn
);
4365 /* Find the old active region end and shrink */
4366 for_each_active_range_index_in_nid(i
, nid
) {
4367 if (early_node_map
[i
].start_pfn
>= start_pfn
&&
4368 early_node_map
[i
].end_pfn
<= end_pfn
) {
4370 early_node_map
[i
].start_pfn
= 0;
4371 early_node_map
[i
].end_pfn
= 0;
4375 if (early_node_map
[i
].start_pfn
< start_pfn
&&
4376 early_node_map
[i
].end_pfn
> start_pfn
) {
4377 unsigned long temp_end_pfn
= early_node_map
[i
].end_pfn
;
4378 early_node_map
[i
].end_pfn
= start_pfn
;
4379 if (temp_end_pfn
> end_pfn
)
4380 add_active_range(nid
, end_pfn
, temp_end_pfn
);
4383 if (early_node_map
[i
].start_pfn
>= start_pfn
&&
4384 early_node_map
[i
].end_pfn
> end_pfn
&&
4385 early_node_map
[i
].start_pfn
< end_pfn
) {
4386 early_node_map
[i
].start_pfn
= end_pfn
;
4394 /* remove the blank ones */
4395 for (i
= nr_nodemap_entries
- 1; i
> 0; i
--) {
4396 if (early_node_map
[i
].nid
!= nid
)
4398 if (early_node_map
[i
].end_pfn
)
4400 /* we found it, get rid of it */
4401 for (j
= i
; j
< nr_nodemap_entries
- 1; j
++)
4402 memcpy(&early_node_map
[j
], &early_node_map
[j
+1],
4403 sizeof(early_node_map
[j
]));
4404 j
= nr_nodemap_entries
- 1;
4405 memset(&early_node_map
[j
], 0, sizeof(early_node_map
[j
]));
4406 nr_nodemap_entries
--;
4411 * remove_all_active_ranges - Remove all currently registered regions
4413 * During discovery, it may be found that a table like SRAT is invalid
4414 * and an alternative discovery method must be used. This function removes
4415 * all currently registered regions.
4417 void __init
remove_all_active_ranges(void)
4419 memset(early_node_map
, 0, sizeof(early_node_map
));
4420 nr_nodemap_entries
= 0;
4423 /* Compare two active node_active_regions */
4424 static int __init
cmp_node_active_region(const void *a
, const void *b
)
4426 struct node_active_region
*arange
= (struct node_active_region
*)a
;
4427 struct node_active_region
*brange
= (struct node_active_region
*)b
;
4429 /* Done this way to avoid overflows */
4430 if (arange
->start_pfn
> brange
->start_pfn
)
4432 if (arange
->start_pfn
< brange
->start_pfn
)
4438 /* sort the node_map by start_pfn */
4439 void __init
sort_node_map(void)
4441 sort(early_node_map
, (size_t)nr_nodemap_entries
,
4442 sizeof(struct node_active_region
),
4443 cmp_node_active_region
, NULL
);
4446 /* Find the lowest pfn for a node */
4447 static unsigned long __init
find_min_pfn_for_node(int nid
)
4450 unsigned long min_pfn
= ULONG_MAX
;
4452 /* Assuming a sorted map, the first range found has the starting pfn */
4453 for_each_active_range_index_in_nid(i
, nid
)
4454 min_pfn
= min(min_pfn
, early_node_map
[i
].start_pfn
);
4456 if (min_pfn
== ULONG_MAX
) {
4458 "Could not find start_pfn for node %d\n", nid
);
4466 * find_min_pfn_with_active_regions - Find the minimum PFN registered
4468 * It returns the minimum PFN based on information provided via
4469 * add_active_range().
4471 unsigned long __init
find_min_pfn_with_active_regions(void)
4473 return find_min_pfn_for_node(MAX_NUMNODES
);
4477 * early_calculate_totalpages()
4478 * Sum pages in active regions for movable zone.
4479 * Populate N_HIGH_MEMORY for calculating usable_nodes.
4481 static unsigned long __init
early_calculate_totalpages(void)
4484 unsigned long totalpages
= 0;
4486 for (i
= 0; i
< nr_nodemap_entries
; i
++) {
4487 unsigned long pages
= early_node_map
[i
].end_pfn
-
4488 early_node_map
[i
].start_pfn
;
4489 totalpages
+= pages
;
4491 node_set_state(early_node_map
[i
].nid
, N_HIGH_MEMORY
);
4497 * Find the PFN the Movable zone begins in each node. Kernel memory
4498 * is spread evenly between nodes as long as the nodes have enough
4499 * memory. When they don't, some nodes will have more kernelcore than
4502 static void __init
find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn
)
4505 unsigned long usable_startpfn
;
4506 unsigned long kernelcore_node
, kernelcore_remaining
;
4507 /* save the state before borrow the nodemask */
4508 nodemask_t saved_node_state
= node_states
[N_HIGH_MEMORY
];
4509 unsigned long totalpages
= early_calculate_totalpages();
4510 int usable_nodes
= nodes_weight(node_states
[N_HIGH_MEMORY
]);
4513 * If movablecore was specified, calculate what size of
4514 * kernelcore that corresponds so that memory usable for
4515 * any allocation type is evenly spread. If both kernelcore
4516 * and movablecore are specified, then the value of kernelcore
4517 * will be used for required_kernelcore if it's greater than
4518 * what movablecore would have allowed.
4520 if (required_movablecore
) {
4521 unsigned long corepages
;
4524 * Round-up so that ZONE_MOVABLE is at least as large as what
4525 * was requested by the user
4527 required_movablecore
=
4528 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
4529 corepages
= totalpages
- required_movablecore
;
4531 required_kernelcore
= max(required_kernelcore
, corepages
);
4534 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
4535 if (!required_kernelcore
)
4538 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
4539 find_usable_zone_for_movable();
4540 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
4543 /* Spread kernelcore memory as evenly as possible throughout nodes */
4544 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4545 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4547 * Recalculate kernelcore_node if the division per node
4548 * now exceeds what is necessary to satisfy the requested
4549 * amount of memory for the kernel
4551 if (required_kernelcore
< kernelcore_node
)
4552 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4555 * As the map is walked, we track how much memory is usable
4556 * by the kernel using kernelcore_remaining. When it is
4557 * 0, the rest of the node is usable by ZONE_MOVABLE
4559 kernelcore_remaining
= kernelcore_node
;
4561 /* Go through each range of PFNs within this node */
4562 for_each_active_range_index_in_nid(i
, nid
) {
4563 unsigned long start_pfn
, end_pfn
;
4564 unsigned long size_pages
;
4566 start_pfn
= max(early_node_map
[i
].start_pfn
,
4567 zone_movable_pfn
[nid
]);
4568 end_pfn
= early_node_map
[i
].end_pfn
;
4569 if (start_pfn
>= end_pfn
)
4572 /* Account for what is only usable for kernelcore */
4573 if (start_pfn
< usable_startpfn
) {
4574 unsigned long kernel_pages
;
4575 kernel_pages
= min(end_pfn
, usable_startpfn
)
4578 kernelcore_remaining
-= min(kernel_pages
,
4579 kernelcore_remaining
);
4580 required_kernelcore
-= min(kernel_pages
,
4581 required_kernelcore
);
4583 /* Continue if range is now fully accounted */
4584 if (end_pfn
<= usable_startpfn
) {
4587 * Push zone_movable_pfn to the end so
4588 * that if we have to rebalance
4589 * kernelcore across nodes, we will
4590 * not double account here
4592 zone_movable_pfn
[nid
] = end_pfn
;
4595 start_pfn
= usable_startpfn
;
4599 * The usable PFN range for ZONE_MOVABLE is from
4600 * start_pfn->end_pfn. Calculate size_pages as the
4601 * number of pages used as kernelcore
4603 size_pages
= end_pfn
- start_pfn
;
4604 if (size_pages
> kernelcore_remaining
)
4605 size_pages
= kernelcore_remaining
;
4606 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
4609 * Some kernelcore has been met, update counts and
4610 * break if the kernelcore for this node has been
4613 required_kernelcore
-= min(required_kernelcore
,
4615 kernelcore_remaining
-= size_pages
;
4616 if (!kernelcore_remaining
)
4622 * If there is still required_kernelcore, we do another pass with one
4623 * less node in the count. This will push zone_movable_pfn[nid] further
4624 * along on the nodes that still have memory until kernelcore is
4628 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
4631 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
4632 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
4633 zone_movable_pfn
[nid
] =
4634 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
4637 /* restore the node_state */
4638 node_states
[N_HIGH_MEMORY
] = saved_node_state
;
4641 /* Any regular memory on that node ? */
4642 static void check_for_regular_memory(pg_data_t
*pgdat
)
4644 #ifdef CONFIG_HIGHMEM
4645 enum zone_type zone_type
;
4647 for (zone_type
= 0; zone_type
<= ZONE_NORMAL
; zone_type
++) {
4648 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4649 if (zone
->present_pages
)
4650 node_set_state(zone_to_nid(zone
), N_NORMAL_MEMORY
);
4656 * free_area_init_nodes - Initialise all pg_data_t and zone data
4657 * @max_zone_pfn: an array of max PFNs for each zone
4659 * This will call free_area_init_node() for each active node in the system.
4660 * Using the page ranges provided by add_active_range(), the size of each
4661 * zone in each node and their holes is calculated. If the maximum PFN
4662 * between two adjacent zones match, it is assumed that the zone is empty.
4663 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
4664 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
4665 * starts where the previous one ended. For example, ZONE_DMA32 starts
4666 * at arch_max_dma_pfn.
4668 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
4673 /* Sort early_node_map as initialisation assumes it is sorted */
4676 /* Record where the zone boundaries are */
4677 memset(arch_zone_lowest_possible_pfn
, 0,
4678 sizeof(arch_zone_lowest_possible_pfn
));
4679 memset(arch_zone_highest_possible_pfn
, 0,
4680 sizeof(arch_zone_highest_possible_pfn
));
4681 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
4682 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
4683 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
4684 if (i
== ZONE_MOVABLE
)
4686 arch_zone_lowest_possible_pfn
[i
] =
4687 arch_zone_highest_possible_pfn
[i
-1];
4688 arch_zone_highest_possible_pfn
[i
] =
4689 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
4691 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
4692 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
4694 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
4695 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
4696 find_zone_movable_pfns_for_nodes(zone_movable_pfn
);
4698 /* Print out the zone ranges */
4699 printk("Zone PFN ranges:\n");
4700 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4701 if (i
== ZONE_MOVABLE
)
4703 printk(" %-8s ", zone_names
[i
]);
4704 if (arch_zone_lowest_possible_pfn
[i
] ==
4705 arch_zone_highest_possible_pfn
[i
])
4708 printk("%0#10lx -> %0#10lx\n",
4709 arch_zone_lowest_possible_pfn
[i
],
4710 arch_zone_highest_possible_pfn
[i
]);
4713 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
4714 printk("Movable zone start PFN for each node\n");
4715 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
4716 if (zone_movable_pfn
[i
])
4717 printk(" Node %d: %lu\n", i
, zone_movable_pfn
[i
]);
4720 /* Print out the early_node_map[] */
4721 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries
);
4722 for (i
= 0; i
< nr_nodemap_entries
; i
++)
4723 printk(" %3d: %0#10lx -> %0#10lx\n", early_node_map
[i
].nid
,
4724 early_node_map
[i
].start_pfn
,
4725 early_node_map
[i
].end_pfn
);
4727 /* Initialise every node */
4728 mminit_verify_pageflags_layout();
4729 setup_nr_node_ids();
4730 for_each_online_node(nid
) {
4731 pg_data_t
*pgdat
= NODE_DATA(nid
);
4732 free_area_init_node(nid
, NULL
,
4733 find_min_pfn_for_node(nid
), NULL
);
4735 /* Any memory on that node */
4736 if (pgdat
->node_present_pages
)
4737 node_set_state(nid
, N_HIGH_MEMORY
);
4738 check_for_regular_memory(pgdat
);
4742 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
4744 unsigned long long coremem
;
4748 coremem
= memparse(p
, &p
);
4749 *core
= coremem
>> PAGE_SHIFT
;
4751 /* Paranoid check that UL is enough for the coremem value */
4752 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
4758 * kernelcore=size sets the amount of memory for use for allocations that
4759 * cannot be reclaimed or migrated.
4761 static int __init
cmdline_parse_kernelcore(char *p
)
4763 return cmdline_parse_core(p
, &required_kernelcore
);
4767 * movablecore=size sets the amount of memory for use for allocations that
4768 * can be reclaimed or migrated.
4770 static int __init
cmdline_parse_movablecore(char *p
)
4772 return cmdline_parse_core(p
, &required_movablecore
);
4775 early_param("kernelcore", cmdline_parse_kernelcore
);
4776 early_param("movablecore", cmdline_parse_movablecore
);
4778 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
4781 * set_dma_reserve - set the specified number of pages reserved in the first zone
4782 * @new_dma_reserve: The number of pages to mark reserved
4784 * The per-cpu batchsize and zone watermarks are determined by present_pages.
4785 * In the DMA zone, a significant percentage may be consumed by kernel image
4786 * and other unfreeable allocations which can skew the watermarks badly. This
4787 * function may optionally be used to account for unfreeable pages in the
4788 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
4789 * smaller per-cpu batchsize.
4791 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
4793 dma_reserve
= new_dma_reserve
;
4796 #ifndef CONFIG_NEED_MULTIPLE_NODES
4797 struct pglist_data __refdata contig_page_data
= {
4798 #ifndef CONFIG_NO_BOOTMEM
4799 .bdata
= &bootmem_node_data
[0]
4802 EXPORT_SYMBOL(contig_page_data
);
4805 void __init
free_area_init(unsigned long *zones_size
)
4807 free_area_init_node(0, zones_size
,
4808 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
4811 static int page_alloc_cpu_notify(struct notifier_block
*self
,
4812 unsigned long action
, void *hcpu
)
4814 int cpu
= (unsigned long)hcpu
;
4816 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
4820 * Spill the event counters of the dead processor
4821 * into the current processors event counters.
4822 * This artificially elevates the count of the current
4825 vm_events_fold_cpu(cpu
);
4828 * Zero the differential counters of the dead processor
4829 * so that the vm statistics are consistent.
4831 * This is only okay since the processor is dead and cannot
4832 * race with what we are doing.
4834 refresh_cpu_vm_stats(cpu
);
4839 void __init
page_alloc_init(void)
4841 hotcpu_notifier(page_alloc_cpu_notify
, 0);
4845 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
4846 * or min_free_kbytes changes.
4848 static void calculate_totalreserve_pages(void)
4850 struct pglist_data
*pgdat
;
4851 unsigned long reserve_pages
= 0;
4852 enum zone_type i
, j
;
4854 for_each_online_pgdat(pgdat
) {
4855 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4856 struct zone
*zone
= pgdat
->node_zones
+ i
;
4857 unsigned long max
= 0;
4859 /* Find valid and maximum lowmem_reserve in the zone */
4860 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
4861 if (zone
->lowmem_reserve
[j
] > max
)
4862 max
= zone
->lowmem_reserve
[j
];
4865 /* we treat the high watermark as reserved pages. */
4866 max
+= high_wmark_pages(zone
);
4868 if (max
> zone
->present_pages
)
4869 max
= zone
->present_pages
;
4870 reserve_pages
+= max
;
4873 totalreserve_pages
= reserve_pages
;
4877 * setup_per_zone_lowmem_reserve - called whenever
4878 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
4879 * has a correct pages reserved value, so an adequate number of
4880 * pages are left in the zone after a successful __alloc_pages().
4882 static void setup_per_zone_lowmem_reserve(void)
4884 struct pglist_data
*pgdat
;
4885 enum zone_type j
, idx
;
4887 for_each_online_pgdat(pgdat
) {
4888 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4889 struct zone
*zone
= pgdat
->node_zones
+ j
;
4890 unsigned long present_pages
= zone
->present_pages
;
4892 zone
->lowmem_reserve
[j
] = 0;
4896 struct zone
*lower_zone
;
4900 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
4901 sysctl_lowmem_reserve_ratio
[idx
] = 1;
4903 lower_zone
= pgdat
->node_zones
+ idx
;
4904 lower_zone
->lowmem_reserve
[j
] = present_pages
/
4905 sysctl_lowmem_reserve_ratio
[idx
];
4906 present_pages
+= lower_zone
->present_pages
;
4911 /* update totalreserve_pages */
4912 calculate_totalreserve_pages();
4916 * setup_per_zone_wmarks - called when min_free_kbytes changes
4917 * or when memory is hot-{added|removed}
4919 * Ensures that the watermark[min,low,high] values for each zone are set
4920 * correctly with respect to min_free_kbytes.
4922 void setup_per_zone_wmarks(void)
4924 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
4925 unsigned long lowmem_pages
= 0;
4927 unsigned long flags
;
4929 /* Calculate total number of !ZONE_HIGHMEM pages */
4930 for_each_zone(zone
) {
4931 if (!is_highmem(zone
))
4932 lowmem_pages
+= zone
->present_pages
;
4935 for_each_zone(zone
) {
4938 spin_lock_irqsave(&zone
->lock
, flags
);
4939 tmp
= (u64
)pages_min
* zone
->present_pages
;
4940 do_div(tmp
, lowmem_pages
);
4941 if (is_highmem(zone
)) {
4943 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
4944 * need highmem pages, so cap pages_min to a small
4947 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
4948 * deltas controls asynch page reclaim, and so should
4949 * not be capped for highmem.
4953 min_pages
= zone
->present_pages
/ 1024;
4954 if (min_pages
< SWAP_CLUSTER_MAX
)
4955 min_pages
= SWAP_CLUSTER_MAX
;
4956 if (min_pages
> 128)
4958 zone
->watermark
[WMARK_MIN
] = min_pages
;
4961 * If it's a lowmem zone, reserve a number of pages
4962 * proportionate to the zone's size.
4964 zone
->watermark
[WMARK_MIN
] = tmp
;
4967 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + (tmp
>> 2);
4968 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + (tmp
>> 1);
4969 setup_zone_migrate_reserve(zone
);
4970 spin_unlock_irqrestore(&zone
->lock
, flags
);
4973 /* update totalreserve_pages */
4974 calculate_totalreserve_pages();
4978 * The inactive anon list should be small enough that the VM never has to
4979 * do too much work, but large enough that each inactive page has a chance
4980 * to be referenced again before it is swapped out.
4982 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
4983 * INACTIVE_ANON pages on this zone's LRU, maintained by the
4984 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
4985 * the anonymous pages are kept on the inactive list.
4988 * memory ratio inactive anon
4989 * -------------------------------------
4998 void calculate_zone_inactive_ratio(struct zone
*zone
)
5000 unsigned int gb
, ratio
;
5002 /* Zone size in gigabytes */
5003 gb
= zone
->present_pages
>> (30 - PAGE_SHIFT
);
5005 ratio
= int_sqrt(10 * gb
);
5009 zone
->inactive_ratio
= ratio
;
5012 static void __init
setup_per_zone_inactive_ratio(void)
5017 calculate_zone_inactive_ratio(zone
);
5021 * Initialise min_free_kbytes.
5023 * For small machines we want it small (128k min). For large machines
5024 * we want it large (64MB max). But it is not linear, because network
5025 * bandwidth does not increase linearly with machine size. We use
5027 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5028 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
5044 static int __init
init_per_zone_wmark_min(void)
5046 unsigned long lowmem_kbytes
;
5048 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
5050 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
5051 if (min_free_kbytes
< 128)
5052 min_free_kbytes
= 128;
5053 if (min_free_kbytes
> 65536)
5054 min_free_kbytes
= 65536;
5055 setup_per_zone_wmarks();
5056 setup_per_zone_lowmem_reserve();
5057 setup_per_zone_inactive_ratio();
5060 module_init(init_per_zone_wmark_min
)
5063 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5064 * that we can call two helper functions whenever min_free_kbytes
5067 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
5068 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5070 proc_dointvec(table
, write
, buffer
, length
, ppos
);
5072 setup_per_zone_wmarks();
5077 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
5078 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5083 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5088 zone
->min_unmapped_pages
= (zone
->present_pages
*
5089 sysctl_min_unmapped_ratio
) / 100;
5093 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
5094 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5099 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5104 zone
->min_slab_pages
= (zone
->present_pages
*
5105 sysctl_min_slab_ratio
) / 100;
5111 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5112 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5113 * whenever sysctl_lowmem_reserve_ratio changes.
5115 * The reserve ratio obviously has absolutely no relation with the
5116 * minimum watermarks. The lowmem reserve ratio can only make sense
5117 * if in function of the boot time zone sizes.
5119 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
5120 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5122 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5123 setup_per_zone_lowmem_reserve();
5128 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5129 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
5130 * can have before it gets flushed back to buddy allocator.
5133 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
5134 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5140 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5141 if (!write
|| (ret
== -EINVAL
))
5143 for_each_populated_zone(zone
) {
5144 for_each_possible_cpu(cpu
) {
5146 high
= zone
->present_pages
/ percpu_pagelist_fraction
;
5147 setup_pagelist_highmark(
5148 per_cpu_ptr(zone
->pageset
, cpu
), high
);
5154 int hashdist
= HASHDIST_DEFAULT
;
5157 static int __init
set_hashdist(char *str
)
5161 hashdist
= simple_strtoul(str
, &str
, 0);
5164 __setup("hashdist=", set_hashdist
);
5168 * allocate a large system hash table from bootmem
5169 * - it is assumed that the hash table must contain an exact power-of-2
5170 * quantity of entries
5171 * - limit is the number of hash buckets, not the total allocation size
5173 void *__init
alloc_large_system_hash(const char *tablename
,
5174 unsigned long bucketsize
,
5175 unsigned long numentries
,
5178 unsigned int *_hash_shift
,
5179 unsigned int *_hash_mask
,
5180 unsigned long limit
)
5182 unsigned long long max
= limit
;
5183 unsigned long log2qty
, size
;
5186 /* allow the kernel cmdline to have a say */
5188 /* round applicable memory size up to nearest megabyte */
5189 numentries
= nr_kernel_pages
;
5190 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
5191 numentries
>>= 20 - PAGE_SHIFT
;
5192 numentries
<<= 20 - PAGE_SHIFT
;
5194 /* limit to 1 bucket per 2^scale bytes of low memory */
5195 if (scale
> PAGE_SHIFT
)
5196 numentries
>>= (scale
- PAGE_SHIFT
);
5198 numentries
<<= (PAGE_SHIFT
- scale
);
5200 /* Make sure we've got at least a 0-order allocation.. */
5201 if (unlikely(flags
& HASH_SMALL
)) {
5202 /* Makes no sense without HASH_EARLY */
5203 WARN_ON(!(flags
& HASH_EARLY
));
5204 if (!(numentries
>> *_hash_shift
)) {
5205 numentries
= 1UL << *_hash_shift
;
5206 BUG_ON(!numentries
);
5208 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
5209 numentries
= PAGE_SIZE
/ bucketsize
;
5211 numentries
= roundup_pow_of_two(numentries
);
5213 /* limit allocation size to 1/16 total memory by default */
5215 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
5216 do_div(max
, bucketsize
);
5219 if (numentries
> max
)
5222 log2qty
= ilog2(numentries
);
5225 size
= bucketsize
<< log2qty
;
5226 if (flags
& HASH_EARLY
)
5227 table
= alloc_bootmem_nopanic(size
);
5229 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
5232 * If bucketsize is not a power-of-two, we may free
5233 * some pages at the end of hash table which
5234 * alloc_pages_exact() automatically does
5236 if (get_order(size
) < MAX_ORDER
) {
5237 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
5238 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
5241 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
5244 panic("Failed to allocate %s hash table\n", tablename
);
5246 printk(KERN_INFO
"%s hash table entries: %ld (order: %d, %lu bytes)\n",
5249 ilog2(size
) - PAGE_SHIFT
,
5253 *_hash_shift
= log2qty
;
5255 *_hash_mask
= (1 << log2qty
) - 1;
5260 /* Return a pointer to the bitmap storing bits affecting a block of pages */
5261 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
5264 #ifdef CONFIG_SPARSEMEM
5265 return __pfn_to_section(pfn
)->pageblock_flags
;
5267 return zone
->pageblock_flags
;
5268 #endif /* CONFIG_SPARSEMEM */
5271 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
5273 #ifdef CONFIG_SPARSEMEM
5274 pfn
&= (PAGES_PER_SECTION
-1);
5275 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5277 pfn
= pfn
- zone
->zone_start_pfn
;
5278 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5279 #endif /* CONFIG_SPARSEMEM */
5283 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5284 * @page: The page within the block of interest
5285 * @start_bitidx: The first bit of interest to retrieve
5286 * @end_bitidx: The last bit of interest
5287 * returns pageblock_bits flags
5289 unsigned long get_pageblock_flags_group(struct page
*page
,
5290 int start_bitidx
, int end_bitidx
)
5293 unsigned long *bitmap
;
5294 unsigned long pfn
, bitidx
;
5295 unsigned long flags
= 0;
5296 unsigned long value
= 1;
5298 zone
= page_zone(page
);
5299 pfn
= page_to_pfn(page
);
5300 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5301 bitidx
= pfn_to_bitidx(zone
, pfn
);
5303 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5304 if (test_bit(bitidx
+ start_bitidx
, bitmap
))
5311 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5312 * @page: The page within the block of interest
5313 * @start_bitidx: The first bit of interest
5314 * @end_bitidx: The last bit of interest
5315 * @flags: The flags to set
5317 void set_pageblock_flags_group(struct page
*page
, unsigned long flags
,
5318 int start_bitidx
, int end_bitidx
)
5321 unsigned long *bitmap
;
5322 unsigned long pfn
, bitidx
;
5323 unsigned long value
= 1;
5325 zone
= page_zone(page
);
5326 pfn
= page_to_pfn(page
);
5327 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5328 bitidx
= pfn_to_bitidx(zone
, pfn
);
5329 VM_BUG_ON(pfn
< zone
->zone_start_pfn
);
5330 VM_BUG_ON(pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
);
5332 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5334 __set_bit(bitidx
+ start_bitidx
, bitmap
);
5336 __clear_bit(bitidx
+ start_bitidx
, bitmap
);
5340 * This is designed as sub function...plz see page_isolation.c also.
5341 * set/clear page block's type to be ISOLATE.
5342 * page allocater never alloc memory from ISOLATE block.
5346 __count_immobile_pages(struct zone
*zone
, struct page
*page
, int count
)
5348 unsigned long pfn
, iter
, found
;
5350 * For avoiding noise data, lru_add_drain_all() should be called
5351 * If ZONE_MOVABLE, the zone never contains immobile pages
5353 if (zone_idx(zone
) == ZONE_MOVABLE
)
5356 if (get_pageblock_migratetype(page
) == MIGRATE_MOVABLE
)
5359 pfn
= page_to_pfn(page
);
5360 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
5361 unsigned long check
= pfn
+ iter
;
5363 if (!pfn_valid_within(check
)) {
5367 page
= pfn_to_page(check
);
5368 if (!page_count(page
)) {
5369 if (PageBuddy(page
))
5370 iter
+= (1 << page_order(page
)) - 1;
5376 * If there are RECLAIMABLE pages, we need to check it.
5377 * But now, memory offline itself doesn't call shrink_slab()
5378 * and it still to be fixed.
5381 * If the page is not RAM, page_count()should be 0.
5382 * we don't need more check. This is an _used_ not-movable page.
5384 * The problematic thing here is PG_reserved pages. PG_reserved
5385 * is set to both of a memory hole page and a _used_ kernel
5394 bool is_pageblock_removable_nolock(struct page
*page
)
5396 struct zone
*zone
= page_zone(page
);
5397 return __count_immobile_pages(zone
, page
, 0);
5400 int set_migratetype_isolate(struct page
*page
)
5403 unsigned long flags
, pfn
;
5404 struct memory_isolate_notify arg
;
5409 zone
= page_zone(page
);
5410 zone_idx
= zone_idx(zone
);
5412 spin_lock_irqsave(&zone
->lock
, flags
);
5414 pfn
= page_to_pfn(page
);
5415 arg
.start_pfn
= pfn
;
5416 arg
.nr_pages
= pageblock_nr_pages
;
5417 arg
.pages_found
= 0;
5420 * It may be possible to isolate a pageblock even if the
5421 * migratetype is not MIGRATE_MOVABLE. The memory isolation
5422 * notifier chain is used by balloon drivers to return the
5423 * number of pages in a range that are held by the balloon
5424 * driver to shrink memory. If all the pages are accounted for
5425 * by balloons, are free, or on the LRU, isolation can continue.
5426 * Later, for example, when memory hotplug notifier runs, these
5427 * pages reported as "can be isolated" should be isolated(freed)
5428 * by the balloon driver through the memory notifier chain.
5430 notifier_ret
= memory_isolate_notify(MEM_ISOLATE_COUNT
, &arg
);
5431 notifier_ret
= notifier_to_errno(notifier_ret
);
5435 * FIXME: Now, memory hotplug doesn't call shrink_slab() by itself.
5436 * We just check MOVABLE pages.
5438 if (__count_immobile_pages(zone
, page
, arg
.pages_found
))
5442 * immobile means "not-on-lru" paes. If immobile is larger than
5443 * removable-by-driver pages reported by notifier, we'll fail.
5448 set_pageblock_migratetype(page
, MIGRATE_ISOLATE
);
5449 move_freepages_block(zone
, page
, MIGRATE_ISOLATE
);
5452 spin_unlock_irqrestore(&zone
->lock
, flags
);
5458 void unset_migratetype_isolate(struct page
*page
)
5461 unsigned long flags
;
5462 zone
= page_zone(page
);
5463 spin_lock_irqsave(&zone
->lock
, flags
);
5464 if (get_pageblock_migratetype(page
) != MIGRATE_ISOLATE
)
5466 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
5467 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
5469 spin_unlock_irqrestore(&zone
->lock
, flags
);
5472 #ifdef CONFIG_MEMORY_HOTREMOVE
5474 * All pages in the range must be isolated before calling this.
5477 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
5483 unsigned long flags
;
5484 /* find the first valid pfn */
5485 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
5490 zone
= page_zone(pfn_to_page(pfn
));
5491 spin_lock_irqsave(&zone
->lock
, flags
);
5493 while (pfn
< end_pfn
) {
5494 if (!pfn_valid(pfn
)) {
5498 page
= pfn_to_page(pfn
);
5499 BUG_ON(page_count(page
));
5500 BUG_ON(!PageBuddy(page
));
5501 order
= page_order(page
);
5502 #ifdef CONFIG_DEBUG_VM
5503 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
5504 pfn
, 1 << order
, end_pfn
);
5506 list_del(&page
->lru
);
5507 rmv_page_order(page
);
5508 zone
->free_area
[order
].nr_free
--;
5509 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
5511 for (i
= 0; i
< (1 << order
); i
++)
5512 SetPageReserved((page
+i
));
5513 pfn
+= (1 << order
);
5515 spin_unlock_irqrestore(&zone
->lock
, flags
);
5519 #ifdef CONFIG_MEMORY_FAILURE
5520 bool is_free_buddy_page(struct page
*page
)
5522 struct zone
*zone
= page_zone(page
);
5523 unsigned long pfn
= page_to_pfn(page
);
5524 unsigned long flags
;
5527 spin_lock_irqsave(&zone
->lock
, flags
);
5528 for (order
= 0; order
< MAX_ORDER
; order
++) {
5529 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
5531 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
5534 spin_unlock_irqrestore(&zone
->lock
, flags
);
5536 return order
< MAX_ORDER
;
5540 static struct trace_print_flags pageflag_names
[] = {
5541 {1UL << PG_locked
, "locked" },
5542 {1UL << PG_error
, "error" },
5543 {1UL << PG_referenced
, "referenced" },
5544 {1UL << PG_uptodate
, "uptodate" },
5545 {1UL << PG_dirty
, "dirty" },
5546 {1UL << PG_lru
, "lru" },
5547 {1UL << PG_active
, "active" },
5548 {1UL << PG_slab
, "slab" },
5549 {1UL << PG_owner_priv_1
, "owner_priv_1" },
5550 {1UL << PG_arch_1
, "arch_1" },
5551 {1UL << PG_reserved
, "reserved" },
5552 {1UL << PG_private
, "private" },
5553 {1UL << PG_private_2
, "private_2" },
5554 {1UL << PG_writeback
, "writeback" },
5555 #ifdef CONFIG_PAGEFLAGS_EXTENDED
5556 {1UL << PG_head
, "head" },
5557 {1UL << PG_tail
, "tail" },
5559 {1UL << PG_compound
, "compound" },
5561 {1UL << PG_swapcache
, "swapcache" },
5562 {1UL << PG_mappedtodisk
, "mappedtodisk" },
5563 {1UL << PG_reclaim
, "reclaim" },
5564 {1UL << PG_buddy
, "buddy" },
5565 {1UL << PG_swapbacked
, "swapbacked" },
5566 {1UL << PG_unevictable
, "unevictable" },
5568 {1UL << PG_mlocked
, "mlocked" },
5570 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
5571 {1UL << PG_uncached
, "uncached" },
5573 #ifdef CONFIG_MEMORY_FAILURE
5574 {1UL << PG_hwpoison
, "hwpoison" },
5579 static void dump_page_flags(unsigned long flags
)
5581 const char *delim
= "";
5585 printk(KERN_ALERT
"page flags: %#lx(", flags
);
5587 /* remove zone id */
5588 flags
&= (1UL << NR_PAGEFLAGS
) - 1;
5590 for (i
= 0; pageflag_names
[i
].name
&& flags
; i
++) {
5592 mask
= pageflag_names
[i
].mask
;
5593 if ((flags
& mask
) != mask
)
5597 printk("%s%s", delim
, pageflag_names
[i
].name
);
5601 /* check for left over flags */
5603 printk("%s%#lx", delim
, flags
);
5608 void dump_page(struct page
*page
)
5611 "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
5612 page
, page_count(page
), page_mapcount(page
),
5613 page
->mapping
, page
->index
);
5614 dump_page_flags(page
->flags
);