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/ratelimit.h>
34 #include <linux/oom.h>
35 #include <linux/notifier.h>
36 #include <linux/topology.h>
37 #include <linux/sysctl.h>
38 #include <linux/cpu.h>
39 #include <linux/cpuset.h>
40 #include <linux/memory_hotplug.h>
41 #include <linux/nodemask.h>
42 #include <linux/vmalloc.h>
43 #include <linux/vmstat.h>
44 #include <linux/mempolicy.h>
45 #include <linux/stop_machine.h>
46 #include <linux/sort.h>
47 #include <linux/pfn.h>
48 #include <linux/backing-dev.h>
49 #include <linux/fault-inject.h>
50 #include <linux/page-isolation.h>
51 #include <linux/page_cgroup.h>
52 #include <linux/debugobjects.h>
53 #include <linux/kmemleak.h>
54 #include <linux/memory.h>
55 #include <linux/compaction.h>
56 #include <trace/events/kmem.h>
57 #include <linux/ftrace_event.h>
58 #include <linux/memcontrol.h>
59 #include <linux/prefetch.h>
60 #include <linux/migrate.h>
61 #include <linux/page-debug-flags.h>
63 #include <asm/tlbflush.h>
64 #include <asm/div64.h>
67 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
68 DEFINE_PER_CPU(int, numa_node
);
69 EXPORT_PER_CPU_SYMBOL(numa_node
);
72 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
74 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
75 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
76 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
77 * defined in <linux/topology.h>.
79 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
80 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
84 * Array of node states.
86 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
87 [N_POSSIBLE
] = NODE_MASK_ALL
,
88 [N_ONLINE
] = { { [0] = 1UL } },
90 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
92 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
94 [N_CPU
] = { { [0] = 1UL } },
97 EXPORT_SYMBOL(node_states
);
99 unsigned long totalram_pages __read_mostly
;
100 unsigned long totalreserve_pages __read_mostly
;
102 * When calculating the number of globally allowed dirty pages, there
103 * is a certain number of per-zone reserves that should not be
104 * considered dirtyable memory. This is the sum of those reserves
105 * over all existing zones that contribute dirtyable memory.
107 unsigned long dirty_balance_reserve __read_mostly
;
109 int percpu_pagelist_fraction
;
110 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
112 #ifdef CONFIG_PM_SLEEP
114 * The following functions are used by the suspend/hibernate code to temporarily
115 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
116 * while devices are suspended. To avoid races with the suspend/hibernate code,
117 * they should always be called with pm_mutex held (gfp_allowed_mask also should
118 * only be modified with pm_mutex held, unless the suspend/hibernate code is
119 * guaranteed not to run in parallel with that modification).
122 static gfp_t saved_gfp_mask
;
124 void pm_restore_gfp_mask(void)
126 WARN_ON(!mutex_is_locked(&pm_mutex
));
127 if (saved_gfp_mask
) {
128 gfp_allowed_mask
= saved_gfp_mask
;
133 void pm_restrict_gfp_mask(void)
135 WARN_ON(!mutex_is_locked(&pm_mutex
));
136 WARN_ON(saved_gfp_mask
);
137 saved_gfp_mask
= gfp_allowed_mask
;
138 gfp_allowed_mask
&= ~GFP_IOFS
;
141 bool pm_suspended_storage(void)
143 if ((gfp_allowed_mask
& GFP_IOFS
) == GFP_IOFS
)
147 #endif /* CONFIG_PM_SLEEP */
149 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
150 int pageblock_order __read_mostly
;
153 static void __free_pages_ok(struct page
*page
, unsigned int order
);
156 * results with 256, 32 in the lowmem_reserve sysctl:
157 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
158 * 1G machine -> (16M dma, 784M normal, 224M high)
159 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
160 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
161 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
163 * TBD: should special case ZONE_DMA32 machines here - in those we normally
164 * don't need any ZONE_NORMAL reservation
166 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
167 #ifdef CONFIG_ZONE_DMA
170 #ifdef CONFIG_ZONE_DMA32
173 #ifdef CONFIG_HIGHMEM
179 EXPORT_SYMBOL(totalram_pages
);
181 static char * const zone_names
[MAX_NR_ZONES
] = {
182 #ifdef CONFIG_ZONE_DMA
185 #ifdef CONFIG_ZONE_DMA32
189 #ifdef CONFIG_HIGHMEM
195 int min_free_kbytes
= 1024;
197 static unsigned long __meminitdata nr_kernel_pages
;
198 static unsigned long __meminitdata nr_all_pages
;
199 static unsigned long __meminitdata dma_reserve
;
201 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
202 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
203 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
204 static unsigned long __initdata required_kernelcore
;
205 static unsigned long __initdata required_movablecore
;
206 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
208 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
210 EXPORT_SYMBOL(movable_zone
);
211 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
214 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
215 int nr_online_nodes __read_mostly
= 1;
216 EXPORT_SYMBOL(nr_node_ids
);
217 EXPORT_SYMBOL(nr_online_nodes
);
220 int page_group_by_mobility_disabled __read_mostly
;
222 static void set_pageblock_migratetype(struct page
*page
, int migratetype
)
225 if (unlikely(page_group_by_mobility_disabled
))
226 migratetype
= MIGRATE_UNMOVABLE
;
228 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
229 PB_migrate
, PB_migrate_end
);
232 bool oom_killer_disabled __read_mostly
;
234 #ifdef CONFIG_DEBUG_VM
235 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
239 unsigned long pfn
= page_to_pfn(page
);
242 seq
= zone_span_seqbegin(zone
);
243 if (pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
245 else if (pfn
< zone
->zone_start_pfn
)
247 } while (zone_span_seqretry(zone
, seq
));
252 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
254 if (!pfn_valid_within(page_to_pfn(page
)))
256 if (zone
!= page_zone(page
))
262 * Temporary debugging check for pages not lying within a given zone.
264 static int bad_range(struct zone
*zone
, struct page
*page
)
266 if (page_outside_zone_boundaries(zone
, page
))
268 if (!page_is_consistent(zone
, page
))
274 static inline int bad_range(struct zone
*zone
, struct page
*page
)
280 static void bad_page(struct page
*page
)
282 static unsigned long resume
;
283 static unsigned long nr_shown
;
284 static unsigned long nr_unshown
;
286 /* Don't complain about poisoned pages */
287 if (PageHWPoison(page
)) {
288 reset_page_mapcount(page
); /* remove PageBuddy */
293 * Allow a burst of 60 reports, then keep quiet for that minute;
294 * or allow a steady drip of one report per second.
296 if (nr_shown
== 60) {
297 if (time_before(jiffies
, resume
)) {
303 "BUG: Bad page state: %lu messages suppressed\n",
310 resume
= jiffies
+ 60 * HZ
;
312 printk(KERN_ALERT
"BUG: Bad page state in process %s pfn:%05lx\n",
313 current
->comm
, page_to_pfn(page
));
319 /* Leave bad fields for debug, except PageBuddy could make trouble */
320 reset_page_mapcount(page
); /* remove PageBuddy */
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 tail pages have their ->first_page
332 * pointing at the head page.
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
;
355 set_page_count(p
, 0);
356 p
->first_page
= page
;
360 /* update __split_huge_page_refcount if you change this function */
361 static int destroy_compound_page(struct page
*page
, unsigned long order
)
364 int nr_pages
= 1 << order
;
367 if (unlikely(compound_order(page
) != order
) ||
368 unlikely(!PageHead(page
))) {
373 __ClearPageHead(page
);
375 for (i
= 1; i
< nr_pages
; i
++) {
376 struct page
*p
= page
+ i
;
378 if (unlikely(!PageTail(p
) || (p
->first_page
!= page
))) {
388 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
393 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
394 * and __GFP_HIGHMEM from hard or soft interrupt context.
396 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
397 for (i
= 0; i
< (1 << order
); i
++)
398 clear_highpage(page
+ i
);
401 #ifdef CONFIG_DEBUG_PAGEALLOC
402 unsigned int _debug_guardpage_minorder
;
404 static int __init
debug_guardpage_minorder_setup(char *buf
)
408 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
409 printk(KERN_ERR
"Bad debug_guardpage_minorder value\n");
412 _debug_guardpage_minorder
= res
;
413 printk(KERN_INFO
"Setting debug_guardpage_minorder to %lu\n", res
);
416 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
418 static inline void set_page_guard_flag(struct page
*page
)
420 __set_bit(PAGE_DEBUG_FLAG_GUARD
, &page
->debug_flags
);
423 static inline void clear_page_guard_flag(struct page
*page
)
425 __clear_bit(PAGE_DEBUG_FLAG_GUARD
, &page
->debug_flags
);
428 static inline void set_page_guard_flag(struct page
*page
) { }
429 static inline void clear_page_guard_flag(struct page
*page
) { }
432 static inline void set_page_order(struct page
*page
, int order
)
434 set_page_private(page
, order
);
435 __SetPageBuddy(page
);
438 static inline void rmv_page_order(struct page
*page
)
440 __ClearPageBuddy(page
);
441 set_page_private(page
, 0);
445 * Locate the struct page for both the matching buddy in our
446 * pair (buddy1) and the combined O(n+1) page they form (page).
448 * 1) Any buddy B1 will have an order O twin B2 which satisfies
449 * the following equation:
451 * For example, if the starting buddy (buddy2) is #8 its order
453 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
455 * 2) Any buddy B will have an order O+1 parent P which
456 * satisfies the following equation:
459 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
461 static inline unsigned long
462 __find_buddy_index(unsigned long page_idx
, unsigned int order
)
464 return page_idx
^ (1 << order
);
468 * This function checks whether a page is free && is the buddy
469 * we can do coalesce a page and its buddy if
470 * (a) the buddy is not in a hole &&
471 * (b) the buddy is in the buddy system &&
472 * (c) a page and its buddy have the same order &&
473 * (d) a page and its buddy are in the same zone.
475 * For recording whether a page is in the buddy system, we set ->_mapcount -2.
476 * Setting, clearing, and testing _mapcount -2 is serialized by zone->lock.
478 * For recording page's order, we use page_private(page).
480 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
483 if (!pfn_valid_within(page_to_pfn(buddy
)))
486 if (page_zone_id(page
) != page_zone_id(buddy
))
489 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
490 VM_BUG_ON(page_count(buddy
) != 0);
494 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
495 VM_BUG_ON(page_count(buddy
) != 0);
502 * Freeing function for a buddy system allocator.
504 * The concept of a buddy system is to maintain direct-mapped table
505 * (containing bit values) for memory blocks of various "orders".
506 * The bottom level table contains the map for the smallest allocatable
507 * units of memory (here, pages), and each level above it describes
508 * pairs of units from the levels below, hence, "buddies".
509 * At a high level, all that happens here is marking the table entry
510 * at the bottom level available, and propagating the changes upward
511 * as necessary, plus some accounting needed to play nicely with other
512 * parts of the VM system.
513 * At each level, we keep a list of pages, which are heads of continuous
514 * free pages of length of (1 << order) and marked with _mapcount -2. Page's
515 * order is recorded in page_private(page) field.
516 * So when we are allocating or freeing one, we can derive the state of the
517 * other. That is, if we allocate a small block, and both were
518 * free, the remainder of the region must be split into blocks.
519 * If a block is freed, and its buddy is also free, then this
520 * triggers coalescing into a block of larger size.
525 static inline void __free_one_page(struct page
*page
,
526 struct zone
*zone
, unsigned int order
,
529 unsigned long page_idx
;
530 unsigned long combined_idx
;
531 unsigned long uninitialized_var(buddy_idx
);
534 if (unlikely(PageCompound(page
)))
535 if (unlikely(destroy_compound_page(page
, order
)))
538 VM_BUG_ON(migratetype
== -1);
540 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
542 VM_BUG_ON(page_idx
& ((1 << order
) - 1));
543 VM_BUG_ON(bad_range(zone
, page
));
545 while (order
< MAX_ORDER
-1) {
546 buddy_idx
= __find_buddy_index(page_idx
, order
);
547 buddy
= page
+ (buddy_idx
- page_idx
);
548 if (!page_is_buddy(page
, buddy
, order
))
551 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
552 * merge with it and move up one order.
554 if (page_is_guard(buddy
)) {
555 clear_page_guard_flag(buddy
);
556 set_page_private(page
, 0);
557 __mod_zone_page_state(zone
, NR_FREE_PAGES
, 1 << order
);
559 list_del(&buddy
->lru
);
560 zone
->free_area
[order
].nr_free
--;
561 rmv_page_order(buddy
);
563 combined_idx
= buddy_idx
& page_idx
;
564 page
= page
+ (combined_idx
- page_idx
);
565 page_idx
= combined_idx
;
568 set_page_order(page
, order
);
571 * If this is not the largest possible page, check if the buddy
572 * of the next-highest order is free. If it is, it's possible
573 * that pages are being freed that will coalesce soon. In case,
574 * that is happening, add the free page to the tail of the list
575 * so it's less likely to be used soon and more likely to be merged
576 * as a higher order page
578 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
579 struct page
*higher_page
, *higher_buddy
;
580 combined_idx
= buddy_idx
& page_idx
;
581 higher_page
= page
+ (combined_idx
- page_idx
);
582 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
583 higher_buddy
= page
+ (buddy_idx
- combined_idx
);
584 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
585 list_add_tail(&page
->lru
,
586 &zone
->free_area
[order
].free_list
[migratetype
]);
591 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
593 zone
->free_area
[order
].nr_free
++;
597 * free_page_mlock() -- clean up attempts to free and mlocked() page.
598 * Page should not be on lru, so no need to fix that up.
599 * free_pages_check() will verify...
601 static inline void free_page_mlock(struct page
*page
)
603 __dec_zone_page_state(page
, NR_MLOCK
);
604 __count_vm_event(UNEVICTABLE_MLOCKFREED
);
607 static inline int free_pages_check(struct page
*page
)
609 if (unlikely(page_mapcount(page
) |
610 (page
->mapping
!= NULL
) |
611 (atomic_read(&page
->_count
) != 0) |
612 (page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
) |
613 (mem_cgroup_bad_page_check(page
)))) {
617 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
618 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
623 * Frees a number of pages from the PCP lists
624 * Assumes all pages on list are in same zone, and of same order.
625 * count is the number of pages to free.
627 * If the zone was previously in an "all pages pinned" state then look to
628 * see if this freeing clears that state.
630 * And clear the zone's pages_scanned counter, to hold off the "all pages are
631 * pinned" detection logic.
633 static void free_pcppages_bulk(struct zone
*zone
, int count
,
634 struct per_cpu_pages
*pcp
)
640 spin_lock(&zone
->lock
);
641 zone
->all_unreclaimable
= 0;
642 zone
->pages_scanned
= 0;
646 struct list_head
*list
;
649 * Remove pages from lists in a round-robin fashion. A
650 * batch_free count is maintained that is incremented when an
651 * empty list is encountered. This is so more pages are freed
652 * off fuller lists instead of spinning excessively around empty
657 if (++migratetype
== MIGRATE_PCPTYPES
)
659 list
= &pcp
->lists
[migratetype
];
660 } while (list_empty(list
));
662 /* This is the only non-empty list. Free them all. */
663 if (batch_free
== MIGRATE_PCPTYPES
)
664 batch_free
= to_free
;
667 page
= list_entry(list
->prev
, struct page
, lru
);
668 /* must delete as __free_one_page list manipulates */
669 list_del(&page
->lru
);
670 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
671 __free_one_page(page
, zone
, 0, page_private(page
));
672 trace_mm_page_pcpu_drain(page
, 0, page_private(page
));
673 } while (--to_free
&& --batch_free
&& !list_empty(list
));
675 __mod_zone_page_state(zone
, NR_FREE_PAGES
, count
);
676 spin_unlock(&zone
->lock
);
679 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
,
682 spin_lock(&zone
->lock
);
683 zone
->all_unreclaimable
= 0;
684 zone
->pages_scanned
= 0;
686 __free_one_page(page
, zone
, order
, migratetype
);
687 __mod_zone_page_state(zone
, NR_FREE_PAGES
, 1 << order
);
688 spin_unlock(&zone
->lock
);
691 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
696 trace_mm_page_free(page
, order
);
697 kmemcheck_free_shadow(page
, order
);
700 page
->mapping
= NULL
;
701 for (i
= 0; i
< (1 << order
); i
++)
702 bad
+= free_pages_check(page
+ i
);
706 if (!PageHighMem(page
)) {
707 debug_check_no_locks_freed(page_address(page
),PAGE_SIZE
<<order
);
708 debug_check_no_obj_freed(page_address(page
),
711 arch_free_page(page
, order
);
712 kernel_map_pages(page
, 1 << order
, 0);
717 static void __free_pages_ok(struct page
*page
, unsigned int order
)
720 int wasMlocked
= __TestClearPageMlocked(page
);
722 if (!free_pages_prepare(page
, order
))
725 local_irq_save(flags
);
726 if (unlikely(wasMlocked
))
727 free_page_mlock(page
);
728 __count_vm_events(PGFREE
, 1 << order
);
729 free_one_page(page_zone(page
), page
, order
,
730 get_pageblock_migratetype(page
));
731 local_irq_restore(flags
);
734 void __meminit
__free_pages_bootmem(struct page
*page
, unsigned int order
)
736 unsigned int nr_pages
= 1 << order
;
740 for (loop
= 0; loop
< nr_pages
; loop
++) {
741 struct page
*p
= &page
[loop
];
743 if (loop
+ 1 < nr_pages
)
745 __ClearPageReserved(p
);
746 set_page_count(p
, 0);
749 set_page_refcounted(page
);
750 __free_pages(page
, order
);
755 * The order of subdivision here is critical for the IO subsystem.
756 * Please do not alter this order without good reasons and regression
757 * testing. Specifically, as large blocks of memory are subdivided,
758 * the order in which smaller blocks are delivered depends on the order
759 * they're subdivided in this function. This is the primary factor
760 * influencing the order in which pages are delivered to the IO
761 * subsystem according to empirical testing, and this is also justified
762 * by considering the behavior of a buddy system containing a single
763 * large block of memory acted on by a series of small allocations.
764 * This behavior is a critical factor in sglist merging's success.
768 static inline void expand(struct zone
*zone
, struct page
*page
,
769 int low
, int high
, struct free_area
*area
,
772 unsigned long size
= 1 << high
;
778 VM_BUG_ON(bad_range(zone
, &page
[size
]));
780 #ifdef CONFIG_DEBUG_PAGEALLOC
781 if (high
< debug_guardpage_minorder()) {
783 * Mark as guard pages (or page), that will allow to
784 * merge back to allocator when buddy will be freed.
785 * Corresponding page table entries will not be touched,
786 * pages will stay not present in virtual address space
788 INIT_LIST_HEAD(&page
[size
].lru
);
789 set_page_guard_flag(&page
[size
]);
790 set_page_private(&page
[size
], high
);
791 /* Guard pages are not available for any usage */
792 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(1 << high
));
796 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
798 set_page_order(&page
[size
], high
);
803 * This page is about to be returned from the page allocator
805 static inline int check_new_page(struct page
*page
)
807 if (unlikely(page_mapcount(page
) |
808 (page
->mapping
!= NULL
) |
809 (atomic_read(&page
->_count
) != 0) |
810 (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
) |
811 (mem_cgroup_bad_page_check(page
)))) {
818 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
822 for (i
= 0; i
< (1 << order
); i
++) {
823 struct page
*p
= page
+ i
;
824 if (unlikely(check_new_page(p
)))
828 set_page_private(page
, 0);
829 set_page_refcounted(page
);
831 arch_alloc_page(page
, order
);
832 kernel_map_pages(page
, 1 << order
, 1);
834 if (gfp_flags
& __GFP_ZERO
)
835 prep_zero_page(page
, order
, gfp_flags
);
837 if (order
&& (gfp_flags
& __GFP_COMP
))
838 prep_compound_page(page
, order
);
844 * Go through the free lists for the given migratetype and remove
845 * the smallest available page from the freelists
848 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
851 unsigned int current_order
;
852 struct free_area
* area
;
855 /* Find a page of the appropriate size in the preferred list */
856 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
857 area
= &(zone
->free_area
[current_order
]);
858 if (list_empty(&area
->free_list
[migratetype
]))
861 page
= list_entry(area
->free_list
[migratetype
].next
,
863 list_del(&page
->lru
);
864 rmv_page_order(page
);
866 expand(zone
, page
, order
, current_order
, area
, migratetype
);
875 * This array describes the order lists are fallen back to when
876 * the free lists for the desirable migrate type are depleted
878 static int fallbacks
[MIGRATE_TYPES
][MIGRATE_TYPES
-1] = {
879 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
880 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
881 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
882 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
, MIGRATE_RESERVE
, MIGRATE_RESERVE
}, /* Never used */
886 * Move the free pages in a range to the free lists of the requested type.
887 * Note that start_page and end_pages are not aligned on a pageblock
888 * boundary. If alignment is required, use move_freepages_block()
890 static int move_freepages(struct zone
*zone
,
891 struct page
*start_page
, struct page
*end_page
,
898 #ifndef CONFIG_HOLES_IN_ZONE
900 * page_zone is not safe to call in this context when
901 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
902 * anyway as we check zone boundaries in move_freepages_block().
903 * Remove at a later date when no bug reports exist related to
904 * grouping pages by mobility
906 BUG_ON(page_zone(start_page
) != page_zone(end_page
));
909 for (page
= start_page
; page
<= end_page
;) {
910 /* Make sure we are not inadvertently changing nodes */
911 VM_BUG_ON(page_to_nid(page
) != zone_to_nid(zone
));
913 if (!pfn_valid_within(page_to_pfn(page
))) {
918 if (!PageBuddy(page
)) {
923 order
= page_order(page
);
924 list_move(&page
->lru
,
925 &zone
->free_area
[order
].free_list
[migratetype
]);
927 pages_moved
+= 1 << order
;
933 static int move_freepages_block(struct zone
*zone
, struct page
*page
,
936 unsigned long start_pfn
, end_pfn
;
937 struct page
*start_page
, *end_page
;
939 start_pfn
= page_to_pfn(page
);
940 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
941 start_page
= pfn_to_page(start_pfn
);
942 end_page
= start_page
+ pageblock_nr_pages
- 1;
943 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
945 /* Do not cross zone boundaries */
946 if (start_pfn
< zone
->zone_start_pfn
)
948 if (end_pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
951 return move_freepages(zone
, start_page
, end_page
, migratetype
);
954 static void change_pageblock_range(struct page
*pageblock_page
,
955 int start_order
, int migratetype
)
957 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
959 while (nr_pageblocks
--) {
960 set_pageblock_migratetype(pageblock_page
, migratetype
);
961 pageblock_page
+= pageblock_nr_pages
;
965 /* Remove an element from the buddy allocator from the fallback list */
966 static inline struct page
*
967 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
)
969 struct free_area
* area
;
974 /* Find the largest possible block of pages in the other list */
975 for (current_order
= MAX_ORDER
-1; current_order
>= order
;
977 for (i
= 0; i
< MIGRATE_TYPES
- 1; i
++) {
978 migratetype
= fallbacks
[start_migratetype
][i
];
980 /* MIGRATE_RESERVE handled later if necessary */
981 if (migratetype
== MIGRATE_RESERVE
)
984 area
= &(zone
->free_area
[current_order
]);
985 if (list_empty(&area
->free_list
[migratetype
]))
988 page
= list_entry(area
->free_list
[migratetype
].next
,
993 * If breaking a large block of pages, move all free
994 * pages to the preferred allocation list. If falling
995 * back for a reclaimable kernel allocation, be more
996 * aggressive about taking ownership of free pages
998 if (unlikely(current_order
>= (pageblock_order
>> 1)) ||
999 start_migratetype
== MIGRATE_RECLAIMABLE
||
1000 page_group_by_mobility_disabled
) {
1001 unsigned long pages
;
1002 pages
= move_freepages_block(zone
, page
,
1005 /* Claim the whole block if over half of it is free */
1006 if (pages
>= (1 << (pageblock_order
-1)) ||
1007 page_group_by_mobility_disabled
)
1008 set_pageblock_migratetype(page
,
1011 migratetype
= start_migratetype
;
1014 /* Remove the page from the freelists */
1015 list_del(&page
->lru
);
1016 rmv_page_order(page
);
1018 /* Take ownership for orders >= pageblock_order */
1019 if (current_order
>= pageblock_order
)
1020 change_pageblock_range(page
, current_order
,
1023 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1025 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
1026 start_migratetype
, migratetype
);
1036 * Do the hard work of removing an element from the buddy allocator.
1037 * Call me with the zone->lock already held.
1039 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
1045 page
= __rmqueue_smallest(zone
, order
, migratetype
);
1047 if (unlikely(!page
) && migratetype
!= MIGRATE_RESERVE
) {
1048 page
= __rmqueue_fallback(zone
, order
, migratetype
);
1051 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1052 * is used because __rmqueue_smallest is an inline function
1053 * and we want just one call site
1056 migratetype
= MIGRATE_RESERVE
;
1061 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1066 * Obtain a specified number of elements from the buddy allocator, all under
1067 * a single hold of the lock, for efficiency. Add them to the supplied list.
1068 * Returns the number of new pages which were placed at *list.
1070 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1071 unsigned long count
, struct list_head
*list
,
1072 int migratetype
, int cold
)
1076 spin_lock(&zone
->lock
);
1077 for (i
= 0; i
< count
; ++i
) {
1078 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
1079 if (unlikely(page
== NULL
))
1083 * Split buddy pages returned by expand() are received here
1084 * in physical page order. The page is added to the callers and
1085 * list and the list head then moves forward. From the callers
1086 * perspective, the linked list is ordered by page number in
1087 * some conditions. This is useful for IO devices that can
1088 * merge IO requests if the physical pages are ordered
1091 if (likely(cold
== 0))
1092 list_add(&page
->lru
, list
);
1094 list_add_tail(&page
->lru
, list
);
1095 set_page_private(page
, migratetype
);
1098 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
1099 spin_unlock(&zone
->lock
);
1105 * Called from the vmstat counter updater to drain pagesets of this
1106 * currently executing processor on remote nodes after they have
1109 * Note that this function must be called with the thread pinned to
1110 * a single processor.
1112 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
1114 unsigned long flags
;
1117 local_irq_save(flags
);
1118 if (pcp
->count
>= pcp
->batch
)
1119 to_drain
= pcp
->batch
;
1121 to_drain
= pcp
->count
;
1122 free_pcppages_bulk(zone
, to_drain
, pcp
);
1123 pcp
->count
-= to_drain
;
1124 local_irq_restore(flags
);
1129 * Drain pages of the indicated processor.
1131 * The processor must either be the current processor and the
1132 * thread pinned to the current processor or a processor that
1135 static void drain_pages(unsigned int cpu
)
1137 unsigned long flags
;
1140 for_each_populated_zone(zone
) {
1141 struct per_cpu_pageset
*pset
;
1142 struct per_cpu_pages
*pcp
;
1144 local_irq_save(flags
);
1145 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
1149 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1152 local_irq_restore(flags
);
1157 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1159 void drain_local_pages(void *arg
)
1161 drain_pages(smp_processor_id());
1165 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1167 * Note that this code is protected against sending an IPI to an offline
1168 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1169 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1170 * nothing keeps CPUs from showing up after we populated the cpumask and
1171 * before the call to on_each_cpu_mask().
1173 void drain_all_pages(void)
1176 struct per_cpu_pageset
*pcp
;
1180 * Allocate in the BSS so we wont require allocation in
1181 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1183 static cpumask_t cpus_with_pcps
;
1186 * We don't care about racing with CPU hotplug event
1187 * as offline notification will cause the notified
1188 * cpu to drain that CPU pcps and on_each_cpu_mask
1189 * disables preemption as part of its processing
1191 for_each_online_cpu(cpu
) {
1192 bool has_pcps
= false;
1193 for_each_populated_zone(zone
) {
1194 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
1195 if (pcp
->pcp
.count
) {
1201 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
1203 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
1205 on_each_cpu_mask(&cpus_with_pcps
, drain_local_pages
, NULL
, 1);
1208 #ifdef CONFIG_HIBERNATION
1210 void mark_free_pages(struct zone
*zone
)
1212 unsigned long pfn
, max_zone_pfn
;
1213 unsigned long flags
;
1215 struct list_head
*curr
;
1217 if (!zone
->spanned_pages
)
1220 spin_lock_irqsave(&zone
->lock
, flags
);
1222 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
1223 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1224 if (pfn_valid(pfn
)) {
1225 struct page
*page
= pfn_to_page(pfn
);
1227 if (!swsusp_page_is_forbidden(page
))
1228 swsusp_unset_page_free(page
);
1231 for_each_migratetype_order(order
, t
) {
1232 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
1235 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
1236 for (i
= 0; i
< (1UL << order
); i
++)
1237 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
1240 spin_unlock_irqrestore(&zone
->lock
, flags
);
1242 #endif /* CONFIG_PM */
1245 * Free a 0-order page
1246 * cold == 1 ? free a cold page : free a hot page
1248 void free_hot_cold_page(struct page
*page
, int cold
)
1250 struct zone
*zone
= page_zone(page
);
1251 struct per_cpu_pages
*pcp
;
1252 unsigned long flags
;
1254 int wasMlocked
= __TestClearPageMlocked(page
);
1256 if (!free_pages_prepare(page
, 0))
1259 migratetype
= get_pageblock_migratetype(page
);
1260 set_page_private(page
, migratetype
);
1261 local_irq_save(flags
);
1262 if (unlikely(wasMlocked
))
1263 free_page_mlock(page
);
1264 __count_vm_event(PGFREE
);
1267 * We only track unmovable, reclaimable and movable on pcp lists.
1268 * Free ISOLATE pages back to the allocator because they are being
1269 * offlined but treat RESERVE as movable pages so we can get those
1270 * areas back if necessary. Otherwise, we may have to free
1271 * excessively into the page allocator
1273 if (migratetype
>= MIGRATE_PCPTYPES
) {
1274 if (unlikely(migratetype
== MIGRATE_ISOLATE
)) {
1275 free_one_page(zone
, page
, 0, migratetype
);
1278 migratetype
= MIGRATE_MOVABLE
;
1281 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1283 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
1285 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
1287 if (pcp
->count
>= pcp
->high
) {
1288 free_pcppages_bulk(zone
, pcp
->batch
, pcp
);
1289 pcp
->count
-= pcp
->batch
;
1293 local_irq_restore(flags
);
1297 * Free a list of 0-order pages
1299 void free_hot_cold_page_list(struct list_head
*list
, int cold
)
1301 struct page
*page
, *next
;
1303 list_for_each_entry_safe(page
, next
, list
, lru
) {
1304 trace_mm_page_free_batched(page
, cold
);
1305 free_hot_cold_page(page
, cold
);
1310 * split_page takes a non-compound higher-order page, and splits it into
1311 * n (1<<order) sub-pages: page[0..n]
1312 * Each sub-page must be freed individually.
1314 * Note: this is probably too low level an operation for use in drivers.
1315 * Please consult with lkml before using this in your driver.
1317 void split_page(struct page
*page
, unsigned int order
)
1321 VM_BUG_ON(PageCompound(page
));
1322 VM_BUG_ON(!page_count(page
));
1324 #ifdef CONFIG_KMEMCHECK
1326 * Split shadow pages too, because free(page[0]) would
1327 * otherwise free the whole shadow.
1329 if (kmemcheck_page_is_tracked(page
))
1330 split_page(virt_to_page(page
[0].shadow
), order
);
1333 for (i
= 1; i
< (1 << order
); i
++)
1334 set_page_refcounted(page
+ i
);
1338 * Similar to split_page except the page is already free. As this is only
1339 * being used for migration, the migratetype of the block also changes.
1340 * As this is called with interrupts disabled, the caller is responsible
1341 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1344 * Note: this is probably too low level an operation for use in drivers.
1345 * Please consult with lkml before using this in your driver.
1347 int split_free_page(struct page
*page
)
1350 unsigned long watermark
;
1353 BUG_ON(!PageBuddy(page
));
1355 zone
= page_zone(page
);
1356 order
= page_order(page
);
1358 /* Obey watermarks as if the page was being allocated */
1359 watermark
= low_wmark_pages(zone
) + (1 << order
);
1360 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
1363 /* Remove page from free list */
1364 list_del(&page
->lru
);
1365 zone
->free_area
[order
].nr_free
--;
1366 rmv_page_order(page
);
1367 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(1UL << order
));
1369 /* Split into individual pages */
1370 set_page_refcounted(page
);
1371 split_page(page
, order
);
1373 if (order
>= pageblock_order
- 1) {
1374 struct page
*endpage
= page
+ (1 << order
) - 1;
1375 for (; page
< endpage
; page
+= pageblock_nr_pages
)
1376 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1383 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1384 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1388 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
1389 struct zone
*zone
, int order
, gfp_t gfp_flags
,
1392 unsigned long flags
;
1394 int cold
= !!(gfp_flags
& __GFP_COLD
);
1397 if (likely(order
== 0)) {
1398 struct per_cpu_pages
*pcp
;
1399 struct list_head
*list
;
1401 local_irq_save(flags
);
1402 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1403 list
= &pcp
->lists
[migratetype
];
1404 if (list_empty(list
)) {
1405 pcp
->count
+= rmqueue_bulk(zone
, 0,
1408 if (unlikely(list_empty(list
)))
1413 page
= list_entry(list
->prev
, struct page
, lru
);
1415 page
= list_entry(list
->next
, struct page
, lru
);
1417 list_del(&page
->lru
);
1420 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
1422 * __GFP_NOFAIL is not to be used in new code.
1424 * All __GFP_NOFAIL callers should be fixed so that they
1425 * properly detect and handle allocation failures.
1427 * We most definitely don't want callers attempting to
1428 * allocate greater than order-1 page units with
1431 WARN_ON_ONCE(order
> 1);
1433 spin_lock_irqsave(&zone
->lock
, flags
);
1434 page
= __rmqueue(zone
, order
, migratetype
);
1435 spin_unlock(&zone
->lock
);
1438 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(1 << order
));
1441 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
1442 zone_statistics(preferred_zone
, zone
, gfp_flags
);
1443 local_irq_restore(flags
);
1445 VM_BUG_ON(bad_range(zone
, page
));
1446 if (prep_new_page(page
, order
, gfp_flags
))
1451 local_irq_restore(flags
);
1455 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
1456 #define ALLOC_WMARK_MIN WMARK_MIN
1457 #define ALLOC_WMARK_LOW WMARK_LOW
1458 #define ALLOC_WMARK_HIGH WMARK_HIGH
1459 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
1461 /* Mask to get the watermark bits */
1462 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
1464 #define ALLOC_HARDER 0x10 /* try to alloc harder */
1465 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
1466 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
1468 #ifdef CONFIG_FAIL_PAGE_ALLOC
1471 struct fault_attr attr
;
1473 u32 ignore_gfp_highmem
;
1474 u32 ignore_gfp_wait
;
1476 } fail_page_alloc
= {
1477 .attr
= FAULT_ATTR_INITIALIZER
,
1478 .ignore_gfp_wait
= 1,
1479 .ignore_gfp_highmem
= 1,
1483 static int __init
setup_fail_page_alloc(char *str
)
1485 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
1487 __setup("fail_page_alloc=", setup_fail_page_alloc
);
1489 static int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1491 if (order
< fail_page_alloc
.min_order
)
1493 if (gfp_mask
& __GFP_NOFAIL
)
1495 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
1497 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
1500 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
1503 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1505 static int __init
fail_page_alloc_debugfs(void)
1507 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
1510 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
1511 &fail_page_alloc
.attr
);
1513 return PTR_ERR(dir
);
1515 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
1516 &fail_page_alloc
.ignore_gfp_wait
))
1518 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
1519 &fail_page_alloc
.ignore_gfp_highmem
))
1521 if (!debugfs_create_u32("min-order", mode
, dir
,
1522 &fail_page_alloc
.min_order
))
1527 debugfs_remove_recursive(dir
);
1532 late_initcall(fail_page_alloc_debugfs
);
1534 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1536 #else /* CONFIG_FAIL_PAGE_ALLOC */
1538 static inline int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1543 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1546 * Return true if free pages are above 'mark'. This takes into account the order
1547 * of the allocation.
1549 static bool __zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1550 int classzone_idx
, int alloc_flags
, long free_pages
)
1552 /* free_pages my go negative - that's OK */
1556 free_pages
-= (1 << order
) - 1;
1557 if (alloc_flags
& ALLOC_HIGH
)
1559 if (alloc_flags
& ALLOC_HARDER
)
1562 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
1564 for (o
= 0; o
< order
; o
++) {
1565 /* At the next order, this order's pages become unavailable */
1566 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1568 /* Require fewer higher order pages to be free */
1571 if (free_pages
<= min
)
1577 bool zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1578 int classzone_idx
, int alloc_flags
)
1580 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1581 zone_page_state(z
, NR_FREE_PAGES
));
1584 bool zone_watermark_ok_safe(struct zone
*z
, int order
, unsigned long mark
,
1585 int classzone_idx
, int alloc_flags
)
1587 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
1589 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
1590 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
1592 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1598 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1599 * skip over zones that are not allowed by the cpuset, or that have
1600 * been recently (in last second) found to be nearly full. See further
1601 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1602 * that have to skip over a lot of full or unallowed zones.
1604 * If the zonelist cache is present in the passed in zonelist, then
1605 * returns a pointer to the allowed node mask (either the current
1606 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1608 * If the zonelist cache is not available for this zonelist, does
1609 * nothing and returns NULL.
1611 * If the fullzones BITMAP in the zonelist cache is stale (more than
1612 * a second since last zap'd) then we zap it out (clear its bits.)
1614 * We hold off even calling zlc_setup, until after we've checked the
1615 * first zone in the zonelist, on the theory that most allocations will
1616 * be satisfied from that first zone, so best to examine that zone as
1617 * quickly as we can.
1619 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1621 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1622 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1624 zlc
= zonelist
->zlcache_ptr
;
1628 if (time_after(jiffies
, zlc
->last_full_zap
+ HZ
)) {
1629 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1630 zlc
->last_full_zap
= jiffies
;
1633 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1634 &cpuset_current_mems_allowed
:
1635 &node_states
[N_HIGH_MEMORY
];
1636 return allowednodes
;
1640 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1641 * if it is worth looking at further for free memory:
1642 * 1) Check that the zone isn't thought to be full (doesn't have its
1643 * bit set in the zonelist_cache fullzones BITMAP).
1644 * 2) Check that the zones node (obtained from the zonelist_cache
1645 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1646 * Return true (non-zero) if zone is worth looking at further, or
1647 * else return false (zero) if it is not.
1649 * This check -ignores- the distinction between various watermarks,
1650 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1651 * found to be full for any variation of these watermarks, it will
1652 * be considered full for up to one second by all requests, unless
1653 * we are so low on memory on all allowed nodes that we are forced
1654 * into the second scan of the zonelist.
1656 * In the second scan we ignore this zonelist cache and exactly
1657 * apply the watermarks to all zones, even it is slower to do so.
1658 * We are low on memory in the second scan, and should leave no stone
1659 * unturned looking for a free page.
1661 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1662 nodemask_t
*allowednodes
)
1664 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1665 int i
; /* index of *z in zonelist zones */
1666 int n
; /* node that zone *z is on */
1668 zlc
= zonelist
->zlcache_ptr
;
1672 i
= z
- zonelist
->_zonerefs
;
1675 /* This zone is worth trying if it is allowed but not full */
1676 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1680 * Given 'z' scanning a zonelist, set the corresponding bit in
1681 * zlc->fullzones, so that subsequent attempts to allocate a page
1682 * from that zone don't waste time re-examining it.
1684 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1686 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1687 int i
; /* index of *z in zonelist zones */
1689 zlc
= zonelist
->zlcache_ptr
;
1693 i
= z
- zonelist
->_zonerefs
;
1695 set_bit(i
, zlc
->fullzones
);
1699 * clear all zones full, called after direct reclaim makes progress so that
1700 * a zone that was recently full is not skipped over for up to a second
1702 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
1704 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1706 zlc
= zonelist
->zlcache_ptr
;
1710 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1713 #else /* CONFIG_NUMA */
1715 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1720 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1721 nodemask_t
*allowednodes
)
1726 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1730 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
1733 #endif /* CONFIG_NUMA */
1736 * get_page_from_freelist goes through the zonelist trying to allocate
1739 static struct page
*
1740 get_page_from_freelist(gfp_t gfp_mask
, nodemask_t
*nodemask
, unsigned int order
,
1741 struct zonelist
*zonelist
, int high_zoneidx
, int alloc_flags
,
1742 struct zone
*preferred_zone
, int migratetype
)
1745 struct page
*page
= NULL
;
1748 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1749 int zlc_active
= 0; /* set if using zonelist_cache */
1750 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1752 classzone_idx
= zone_idx(preferred_zone
);
1755 * Scan zonelist, looking for a zone with enough free.
1756 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1758 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
1759 high_zoneidx
, nodemask
) {
1760 if (NUMA_BUILD
&& zlc_active
&&
1761 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1763 if ((alloc_flags
& ALLOC_CPUSET
) &&
1764 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1767 * When allocating a page cache page for writing, we
1768 * want to get it from a zone that is within its dirty
1769 * limit, such that no single zone holds more than its
1770 * proportional share of globally allowed dirty pages.
1771 * The dirty limits take into account the zone's
1772 * lowmem reserves and high watermark so that kswapd
1773 * should be able to balance it without having to
1774 * write pages from its LRU list.
1776 * This may look like it could increase pressure on
1777 * lower zones by failing allocations in higher zones
1778 * before they are full. But the pages that do spill
1779 * over are limited as the lower zones are protected
1780 * by this very same mechanism. It should not become
1781 * a practical burden to them.
1783 * XXX: For now, allow allocations to potentially
1784 * exceed the per-zone dirty limit in the slowpath
1785 * (ALLOC_WMARK_LOW unset) before going into reclaim,
1786 * which is important when on a NUMA setup the allowed
1787 * zones are together not big enough to reach the
1788 * global limit. The proper fix for these situations
1789 * will require awareness of zones in the
1790 * dirty-throttling and the flusher threads.
1792 if ((alloc_flags
& ALLOC_WMARK_LOW
) &&
1793 (gfp_mask
& __GFP_WRITE
) && !zone_dirty_ok(zone
))
1794 goto this_zone_full
;
1796 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
1797 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
1801 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
1802 if (zone_watermark_ok(zone
, order
, mark
,
1803 classzone_idx
, alloc_flags
))
1806 if (NUMA_BUILD
&& !did_zlc_setup
&& nr_online_nodes
> 1) {
1808 * we do zlc_setup if there are multiple nodes
1809 * and before considering the first zone allowed
1812 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1817 if (zone_reclaim_mode
== 0)
1818 goto this_zone_full
;
1821 * As we may have just activated ZLC, check if the first
1822 * eligible zone has failed zone_reclaim recently.
1824 if (NUMA_BUILD
&& zlc_active
&&
1825 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1828 ret
= zone_reclaim(zone
, gfp_mask
, order
);
1830 case ZONE_RECLAIM_NOSCAN
:
1833 case ZONE_RECLAIM_FULL
:
1834 /* scanned but unreclaimable */
1837 /* did we reclaim enough */
1838 if (!zone_watermark_ok(zone
, order
, mark
,
1839 classzone_idx
, alloc_flags
))
1840 goto this_zone_full
;
1845 page
= buffered_rmqueue(preferred_zone
, zone
, order
,
1846 gfp_mask
, migratetype
);
1851 zlc_mark_zone_full(zonelist
, z
);
1854 if (unlikely(NUMA_BUILD
&& page
== NULL
&& zlc_active
)) {
1855 /* Disable zlc cache for second zonelist scan */
1863 * Large machines with many possible nodes should not always dump per-node
1864 * meminfo in irq context.
1866 static inline bool should_suppress_show_mem(void)
1871 ret
= in_interrupt();
1876 static DEFINE_RATELIMIT_STATE(nopage_rs
,
1877 DEFAULT_RATELIMIT_INTERVAL
,
1878 DEFAULT_RATELIMIT_BURST
);
1880 void warn_alloc_failed(gfp_t gfp_mask
, int order
, const char *fmt
, ...)
1882 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
1884 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
1885 debug_guardpage_minorder() > 0)
1889 * This documents exceptions given to allocations in certain
1890 * contexts that are allowed to allocate outside current's set
1893 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
1894 if (test_thread_flag(TIF_MEMDIE
) ||
1895 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
1896 filter
&= ~SHOW_MEM_FILTER_NODES
;
1897 if (in_interrupt() || !(gfp_mask
& __GFP_WAIT
))
1898 filter
&= ~SHOW_MEM_FILTER_NODES
;
1901 struct va_format vaf
;
1904 va_start(args
, fmt
);
1909 pr_warn("%pV", &vaf
);
1914 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
1915 current
->comm
, order
, gfp_mask
);
1918 if (!should_suppress_show_mem())
1923 should_alloc_retry(gfp_t gfp_mask
, unsigned int order
,
1924 unsigned long did_some_progress
,
1925 unsigned long pages_reclaimed
)
1927 /* Do not loop if specifically requested */
1928 if (gfp_mask
& __GFP_NORETRY
)
1931 /* Always retry if specifically requested */
1932 if (gfp_mask
& __GFP_NOFAIL
)
1936 * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
1937 * making forward progress without invoking OOM. Suspend also disables
1938 * storage devices so kswapd will not help. Bail if we are suspending.
1940 if (!did_some_progress
&& pm_suspended_storage())
1944 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
1945 * means __GFP_NOFAIL, but that may not be true in other
1948 if (order
<= PAGE_ALLOC_COSTLY_ORDER
)
1952 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
1953 * specified, then we retry until we no longer reclaim any pages
1954 * (above), or we've reclaimed an order of pages at least as
1955 * large as the allocation's order. In both cases, if the
1956 * allocation still fails, we stop retrying.
1958 if (gfp_mask
& __GFP_REPEAT
&& pages_reclaimed
< (1 << order
))
1964 static inline struct page
*
1965 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
1966 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1967 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
1972 /* Acquire the OOM killer lock for the zones in zonelist */
1973 if (!try_set_zonelist_oom(zonelist
, gfp_mask
)) {
1974 schedule_timeout_uninterruptible(1);
1979 * Go through the zonelist yet one more time, keep very high watermark
1980 * here, this is only to catch a parallel oom killing, we must fail if
1981 * we're still under heavy pressure.
1983 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
,
1984 order
, zonelist
, high_zoneidx
,
1985 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
,
1986 preferred_zone
, migratetype
);
1990 if (!(gfp_mask
& __GFP_NOFAIL
)) {
1991 /* The OOM killer will not help higher order allocs */
1992 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
1994 /* The OOM killer does not needlessly kill tasks for lowmem */
1995 if (high_zoneidx
< ZONE_NORMAL
)
1998 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
1999 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
2000 * The caller should handle page allocation failure by itself if
2001 * it specifies __GFP_THISNODE.
2002 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
2004 if (gfp_mask
& __GFP_THISNODE
)
2007 /* Exhausted what can be done so it's blamo time */
2008 out_of_memory(zonelist
, gfp_mask
, order
, nodemask
, false);
2011 clear_zonelist_oom(zonelist
, gfp_mask
);
2015 #ifdef CONFIG_COMPACTION
2016 /* Try memory compaction for high-order allocations before reclaim */
2017 static struct page
*
2018 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2019 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2020 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2021 int migratetype
, bool sync_migration
,
2022 bool *deferred_compaction
,
2023 unsigned long *did_some_progress
)
2030 if (compaction_deferred(preferred_zone
, order
)) {
2031 *deferred_compaction
= true;
2035 current
->flags
|= PF_MEMALLOC
;
2036 *did_some_progress
= try_to_compact_pages(zonelist
, order
, gfp_mask
,
2037 nodemask
, sync_migration
);
2038 current
->flags
&= ~PF_MEMALLOC
;
2039 if (*did_some_progress
!= COMPACT_SKIPPED
) {
2041 /* Page migration frees to the PCP lists but we want merging */
2042 drain_pages(get_cpu());
2045 page
= get_page_from_freelist(gfp_mask
, nodemask
,
2046 order
, zonelist
, high_zoneidx
,
2047 alloc_flags
, preferred_zone
,
2050 preferred_zone
->compact_considered
= 0;
2051 preferred_zone
->compact_defer_shift
= 0;
2052 if (order
>= preferred_zone
->compact_order_failed
)
2053 preferred_zone
->compact_order_failed
= order
+ 1;
2054 count_vm_event(COMPACTSUCCESS
);
2059 * It's bad if compaction run occurs and fails.
2060 * The most likely reason is that pages exist,
2061 * but not enough to satisfy watermarks.
2063 count_vm_event(COMPACTFAIL
);
2066 * As async compaction considers a subset of pageblocks, only
2067 * defer if the failure was a sync compaction failure.
2070 defer_compaction(preferred_zone
, order
);
2078 static inline struct page
*
2079 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2080 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2081 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2082 int migratetype
, bool sync_migration
,
2083 bool *deferred_compaction
,
2084 unsigned long *did_some_progress
)
2088 #endif /* CONFIG_COMPACTION */
2090 /* The really slow allocator path where we enter direct reclaim */
2091 static inline struct page
*
2092 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
2093 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2094 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2095 int migratetype
, unsigned long *did_some_progress
)
2097 struct page
*page
= NULL
;
2098 struct reclaim_state reclaim_state
;
2099 bool drained
= false;
2103 /* We now go into synchronous reclaim */
2104 cpuset_memory_pressure_bump();
2105 current
->flags
|= PF_MEMALLOC
;
2106 lockdep_set_current_reclaim_state(gfp_mask
);
2107 reclaim_state
.reclaimed_slab
= 0;
2108 current
->reclaim_state
= &reclaim_state
;
2110 *did_some_progress
= try_to_free_pages(zonelist
, order
, gfp_mask
, nodemask
);
2112 current
->reclaim_state
= NULL
;
2113 lockdep_clear_current_reclaim_state();
2114 current
->flags
&= ~PF_MEMALLOC
;
2118 if (unlikely(!(*did_some_progress
)))
2121 /* After successful reclaim, reconsider all zones for allocation */
2123 zlc_clear_zones_full(zonelist
);
2126 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
2127 zonelist
, high_zoneidx
,
2128 alloc_flags
, preferred_zone
,
2132 * If an allocation failed after direct reclaim, it could be because
2133 * pages are pinned on the per-cpu lists. Drain them and try again
2135 if (!page
&& !drained
) {
2145 * This is called in the allocator slow-path if the allocation request is of
2146 * sufficient urgency to ignore watermarks and take other desperate measures
2148 static inline struct page
*
2149 __alloc_pages_high_priority(gfp_t gfp_mask
, unsigned int order
,
2150 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2151 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2157 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
2158 zonelist
, high_zoneidx
, ALLOC_NO_WATERMARKS
,
2159 preferred_zone
, migratetype
);
2161 if (!page
&& gfp_mask
& __GFP_NOFAIL
)
2162 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2163 } while (!page
&& (gfp_mask
& __GFP_NOFAIL
));
2169 void wake_all_kswapd(unsigned int order
, struct zonelist
*zonelist
,
2170 enum zone_type high_zoneidx
,
2171 enum zone_type classzone_idx
)
2176 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
)
2177 wakeup_kswapd(zone
, order
, classzone_idx
);
2181 gfp_to_alloc_flags(gfp_t gfp_mask
)
2183 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
2184 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2186 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2187 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
2190 * The caller may dip into page reserves a bit more if the caller
2191 * cannot run direct reclaim, or if the caller has realtime scheduling
2192 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2193 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
2195 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
2199 * Not worth trying to allocate harder for
2200 * __GFP_NOMEMALLOC even if it can't schedule.
2202 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2203 alloc_flags
|= ALLOC_HARDER
;
2205 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
2206 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
2208 alloc_flags
&= ~ALLOC_CPUSET
;
2209 } else if (unlikely(rt_task(current
)) && !in_interrupt())
2210 alloc_flags
|= ALLOC_HARDER
;
2212 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
2213 if (!in_interrupt() &&
2214 ((current
->flags
& PF_MEMALLOC
) ||
2215 unlikely(test_thread_flag(TIF_MEMDIE
))))
2216 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2222 static inline struct page
*
2223 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
2224 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2225 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2228 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2229 struct page
*page
= NULL
;
2231 unsigned long pages_reclaimed
= 0;
2232 unsigned long did_some_progress
;
2233 bool sync_migration
= false;
2234 bool deferred_compaction
= false;
2237 * In the slowpath, we sanity check order to avoid ever trying to
2238 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2239 * be using allocators in order of preference for an area that is
2242 if (order
>= MAX_ORDER
) {
2243 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
2248 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
2249 * __GFP_NOWARN set) should not cause reclaim since the subsystem
2250 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
2251 * using a larger set of nodes after it has established that the
2252 * allowed per node queues are empty and that nodes are
2255 if (NUMA_BUILD
&& (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
2259 if (!(gfp_mask
& __GFP_NO_KSWAPD
))
2260 wake_all_kswapd(order
, zonelist
, high_zoneidx
,
2261 zone_idx(preferred_zone
));
2264 * OK, we're below the kswapd watermark and have kicked background
2265 * reclaim. Now things get more complex, so set up alloc_flags according
2266 * to how we want to proceed.
2268 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
2271 * Find the true preferred zone if the allocation is unconstrained by
2274 if (!(alloc_flags
& ALLOC_CPUSET
) && !nodemask
)
2275 first_zones_zonelist(zonelist
, high_zoneidx
, NULL
,
2279 /* This is the last chance, in general, before the goto nopage. */
2280 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
, zonelist
,
2281 high_zoneidx
, alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2282 preferred_zone
, migratetype
);
2286 /* Allocate without watermarks if the context allows */
2287 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
2288 page
= __alloc_pages_high_priority(gfp_mask
, order
,
2289 zonelist
, high_zoneidx
, nodemask
,
2290 preferred_zone
, migratetype
);
2295 /* Atomic allocations - we can't balance anything */
2299 /* Avoid recursion of direct reclaim */
2300 if (current
->flags
& PF_MEMALLOC
)
2303 /* Avoid allocations with no watermarks from looping endlessly */
2304 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
2308 * Try direct compaction. The first pass is asynchronous. Subsequent
2309 * attempts after direct reclaim are synchronous
2311 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
2312 zonelist
, high_zoneidx
,
2314 alloc_flags
, preferred_zone
,
2315 migratetype
, sync_migration
,
2316 &deferred_compaction
,
2317 &did_some_progress
);
2320 sync_migration
= true;
2323 * If compaction is deferred for high-order allocations, it is because
2324 * sync compaction recently failed. In this is the case and the caller
2325 * has requested the system not be heavily disrupted, fail the
2326 * allocation now instead of entering direct reclaim
2328 if (deferred_compaction
&& (gfp_mask
& __GFP_NO_KSWAPD
))
2331 /* Try direct reclaim and then allocating */
2332 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
,
2333 zonelist
, high_zoneidx
,
2335 alloc_flags
, preferred_zone
,
2336 migratetype
, &did_some_progress
);
2341 * If we failed to make any progress reclaiming, then we are
2342 * running out of options and have to consider going OOM
2344 if (!did_some_progress
) {
2345 if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
2346 if (oom_killer_disabled
)
2348 /* Coredumps can quickly deplete all memory reserves */
2349 if ((current
->flags
& PF_DUMPCORE
) &&
2350 !(gfp_mask
& __GFP_NOFAIL
))
2352 page
= __alloc_pages_may_oom(gfp_mask
, order
,
2353 zonelist
, high_zoneidx
,
2354 nodemask
, preferred_zone
,
2359 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2361 * The oom killer is not called for high-order
2362 * allocations that may fail, so if no progress
2363 * is being made, there are no other options and
2364 * retrying is unlikely to help.
2366 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2369 * The oom killer is not called for lowmem
2370 * allocations to prevent needlessly killing
2373 if (high_zoneidx
< ZONE_NORMAL
)
2381 /* Check if we should retry the allocation */
2382 pages_reclaimed
+= did_some_progress
;
2383 if (should_alloc_retry(gfp_mask
, order
, did_some_progress
,
2385 /* Wait for some write requests to complete then retry */
2386 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2390 * High-order allocations do not necessarily loop after
2391 * direct reclaim and reclaim/compaction depends on compaction
2392 * being called after reclaim so call directly if necessary
2394 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
2395 zonelist
, high_zoneidx
,
2397 alloc_flags
, preferred_zone
,
2398 migratetype
, sync_migration
,
2399 &deferred_compaction
,
2400 &did_some_progress
);
2406 warn_alloc_failed(gfp_mask
, order
, NULL
);
2409 if (kmemcheck_enabled
)
2410 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
2416 * This is the 'heart' of the zoned buddy allocator.
2419 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
2420 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
2422 enum zone_type high_zoneidx
= gfp_zone(gfp_mask
);
2423 struct zone
*preferred_zone
;
2424 struct page
*page
= NULL
;
2425 int migratetype
= allocflags_to_migratetype(gfp_mask
);
2426 unsigned int cpuset_mems_cookie
;
2428 gfp_mask
&= gfp_allowed_mask
;
2430 lockdep_trace_alloc(gfp_mask
);
2432 might_sleep_if(gfp_mask
& __GFP_WAIT
);
2434 if (should_fail_alloc_page(gfp_mask
, order
))
2438 * Check the zones suitable for the gfp_mask contain at least one
2439 * valid zone. It's possible to have an empty zonelist as a result
2440 * of GFP_THISNODE and a memoryless node
2442 if (unlikely(!zonelist
->_zonerefs
->zone
))
2446 cpuset_mems_cookie
= get_mems_allowed();
2448 /* The preferred zone is used for statistics later */
2449 first_zones_zonelist(zonelist
, high_zoneidx
,
2450 nodemask
? : &cpuset_current_mems_allowed
,
2452 if (!preferred_zone
)
2455 /* First allocation attempt */
2456 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
, order
,
2457 zonelist
, high_zoneidx
, ALLOC_WMARK_LOW
|ALLOC_CPUSET
,
2458 preferred_zone
, migratetype
);
2459 if (unlikely(!page
))
2460 page
= __alloc_pages_slowpath(gfp_mask
, order
,
2461 zonelist
, high_zoneidx
, nodemask
,
2462 preferred_zone
, migratetype
);
2464 trace_mm_page_alloc(page
, order
, gfp_mask
, migratetype
);
2468 * When updating a task's mems_allowed, it is possible to race with
2469 * parallel threads in such a way that an allocation can fail while
2470 * the mask is being updated. If a page allocation is about to fail,
2471 * check if the cpuset changed during allocation and if so, retry.
2473 if (unlikely(!put_mems_allowed(cpuset_mems_cookie
) && !page
))
2478 EXPORT_SYMBOL(__alloc_pages_nodemask
);
2481 * Common helper functions.
2483 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
2488 * __get_free_pages() returns a 32-bit address, which cannot represent
2491 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
2493 page
= alloc_pages(gfp_mask
, order
);
2496 return (unsigned long) page_address(page
);
2498 EXPORT_SYMBOL(__get_free_pages
);
2500 unsigned long get_zeroed_page(gfp_t gfp_mask
)
2502 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
2504 EXPORT_SYMBOL(get_zeroed_page
);
2506 void __free_pages(struct page
*page
, unsigned int order
)
2508 if (put_page_testzero(page
)) {
2510 free_hot_cold_page(page
, 0);
2512 __free_pages_ok(page
, order
);
2516 EXPORT_SYMBOL(__free_pages
);
2518 void free_pages(unsigned long addr
, unsigned int order
)
2521 VM_BUG_ON(!virt_addr_valid((void *)addr
));
2522 __free_pages(virt_to_page((void *)addr
), order
);
2526 EXPORT_SYMBOL(free_pages
);
2528 static void *make_alloc_exact(unsigned long addr
, unsigned order
, size_t size
)
2531 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
2532 unsigned long used
= addr
+ PAGE_ALIGN(size
);
2534 split_page(virt_to_page((void *)addr
), order
);
2535 while (used
< alloc_end
) {
2540 return (void *)addr
;
2544 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2545 * @size: the number of bytes to allocate
2546 * @gfp_mask: GFP flags for the allocation
2548 * This function is similar to alloc_pages(), except that it allocates the
2549 * minimum number of pages to satisfy the request. alloc_pages() can only
2550 * allocate memory in power-of-two pages.
2552 * This function is also limited by MAX_ORDER.
2554 * Memory allocated by this function must be released by free_pages_exact().
2556 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
2558 unsigned int order
= get_order(size
);
2561 addr
= __get_free_pages(gfp_mask
, order
);
2562 return make_alloc_exact(addr
, order
, size
);
2564 EXPORT_SYMBOL(alloc_pages_exact
);
2567 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
2569 * @nid: the preferred node ID where memory should be allocated
2570 * @size: the number of bytes to allocate
2571 * @gfp_mask: GFP flags for the allocation
2573 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
2575 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
2578 void *alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
2580 unsigned order
= get_order(size
);
2581 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
2584 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
2586 EXPORT_SYMBOL(alloc_pages_exact_nid
);
2589 * free_pages_exact - release memory allocated via alloc_pages_exact()
2590 * @virt: the value returned by alloc_pages_exact.
2591 * @size: size of allocation, same value as passed to alloc_pages_exact().
2593 * Release the memory allocated by a previous call to alloc_pages_exact.
2595 void free_pages_exact(void *virt
, size_t size
)
2597 unsigned long addr
= (unsigned long)virt
;
2598 unsigned long end
= addr
+ PAGE_ALIGN(size
);
2600 while (addr
< end
) {
2605 EXPORT_SYMBOL(free_pages_exact
);
2607 static unsigned int nr_free_zone_pages(int offset
)
2612 /* Just pick one node, since fallback list is circular */
2613 unsigned int sum
= 0;
2615 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
2617 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
2618 unsigned long size
= zone
->present_pages
;
2619 unsigned long high
= high_wmark_pages(zone
);
2628 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
2630 unsigned int nr_free_buffer_pages(void)
2632 return nr_free_zone_pages(gfp_zone(GFP_USER
));
2634 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
2637 * Amount of free RAM allocatable within all zones
2639 unsigned int nr_free_pagecache_pages(void)
2641 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
2644 static inline void show_node(struct zone
*zone
)
2647 printk("Node %d ", zone_to_nid(zone
));
2650 void si_meminfo(struct sysinfo
*val
)
2652 val
->totalram
= totalram_pages
;
2654 val
->freeram
= global_page_state(NR_FREE_PAGES
);
2655 val
->bufferram
= nr_blockdev_pages();
2656 val
->totalhigh
= totalhigh_pages
;
2657 val
->freehigh
= nr_free_highpages();
2658 val
->mem_unit
= PAGE_SIZE
;
2661 EXPORT_SYMBOL(si_meminfo
);
2664 void si_meminfo_node(struct sysinfo
*val
, int nid
)
2666 pg_data_t
*pgdat
= NODE_DATA(nid
);
2668 val
->totalram
= pgdat
->node_present_pages
;
2669 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
2670 #ifdef CONFIG_HIGHMEM
2671 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
2672 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
2678 val
->mem_unit
= PAGE_SIZE
;
2683 * Determine whether the node should be displayed or not, depending on whether
2684 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
2686 bool skip_free_areas_node(unsigned int flags
, int nid
)
2689 unsigned int cpuset_mems_cookie
;
2691 if (!(flags
& SHOW_MEM_FILTER_NODES
))
2695 cpuset_mems_cookie
= get_mems_allowed();
2696 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
2697 } while (!put_mems_allowed(cpuset_mems_cookie
));
2702 #define K(x) ((x) << (PAGE_SHIFT-10))
2705 * Show free area list (used inside shift_scroll-lock stuff)
2706 * We also calculate the percentage fragmentation. We do this by counting the
2707 * memory on each free list with the exception of the first item on the list.
2708 * Suppresses nodes that are not allowed by current's cpuset if
2709 * SHOW_MEM_FILTER_NODES is passed.
2711 void show_free_areas(unsigned int filter
)
2716 for_each_populated_zone(zone
) {
2717 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
2720 printk("%s per-cpu:\n", zone
->name
);
2722 for_each_online_cpu(cpu
) {
2723 struct per_cpu_pageset
*pageset
;
2725 pageset
= per_cpu_ptr(zone
->pageset
, cpu
);
2727 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
2728 cpu
, pageset
->pcp
.high
,
2729 pageset
->pcp
.batch
, pageset
->pcp
.count
);
2733 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
2734 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
2736 " dirty:%lu writeback:%lu unstable:%lu\n"
2737 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2738 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
2739 global_page_state(NR_ACTIVE_ANON
),
2740 global_page_state(NR_INACTIVE_ANON
),
2741 global_page_state(NR_ISOLATED_ANON
),
2742 global_page_state(NR_ACTIVE_FILE
),
2743 global_page_state(NR_INACTIVE_FILE
),
2744 global_page_state(NR_ISOLATED_FILE
),
2745 global_page_state(NR_UNEVICTABLE
),
2746 global_page_state(NR_FILE_DIRTY
),
2747 global_page_state(NR_WRITEBACK
),
2748 global_page_state(NR_UNSTABLE_NFS
),
2749 global_page_state(NR_FREE_PAGES
),
2750 global_page_state(NR_SLAB_RECLAIMABLE
),
2751 global_page_state(NR_SLAB_UNRECLAIMABLE
),
2752 global_page_state(NR_FILE_MAPPED
),
2753 global_page_state(NR_SHMEM
),
2754 global_page_state(NR_PAGETABLE
),
2755 global_page_state(NR_BOUNCE
));
2757 for_each_populated_zone(zone
) {
2760 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
2768 " active_anon:%lukB"
2769 " inactive_anon:%lukB"
2770 " active_file:%lukB"
2771 " inactive_file:%lukB"
2772 " unevictable:%lukB"
2773 " isolated(anon):%lukB"
2774 " isolated(file):%lukB"
2781 " slab_reclaimable:%lukB"
2782 " slab_unreclaimable:%lukB"
2783 " kernel_stack:%lukB"
2787 " writeback_tmp:%lukB"
2788 " pages_scanned:%lu"
2789 " all_unreclaimable? %s"
2792 K(zone_page_state(zone
, NR_FREE_PAGES
)),
2793 K(min_wmark_pages(zone
)),
2794 K(low_wmark_pages(zone
)),
2795 K(high_wmark_pages(zone
)),
2796 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
2797 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
2798 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
2799 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
2800 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
2801 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
2802 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
2803 K(zone
->present_pages
),
2804 K(zone_page_state(zone
, NR_MLOCK
)),
2805 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
2806 K(zone_page_state(zone
, NR_WRITEBACK
)),
2807 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
2808 K(zone_page_state(zone
, NR_SHMEM
)),
2809 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
2810 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
2811 zone_page_state(zone
, NR_KERNEL_STACK
) *
2813 K(zone_page_state(zone
, NR_PAGETABLE
)),
2814 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
2815 K(zone_page_state(zone
, NR_BOUNCE
)),
2816 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
2817 zone
->pages_scanned
,
2818 (zone
->all_unreclaimable
? "yes" : "no")
2820 printk("lowmem_reserve[]:");
2821 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
2822 printk(" %lu", zone
->lowmem_reserve
[i
]);
2826 for_each_populated_zone(zone
) {
2827 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
2829 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
2832 printk("%s: ", zone
->name
);
2834 spin_lock_irqsave(&zone
->lock
, flags
);
2835 for (order
= 0; order
< MAX_ORDER
; order
++) {
2836 nr
[order
] = zone
->free_area
[order
].nr_free
;
2837 total
+= nr
[order
] << order
;
2839 spin_unlock_irqrestore(&zone
->lock
, flags
);
2840 for (order
= 0; order
< MAX_ORDER
; order
++)
2841 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
2842 printk("= %lukB\n", K(total
));
2845 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
2847 show_swap_cache_info();
2850 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
2852 zoneref
->zone
= zone
;
2853 zoneref
->zone_idx
= zone_idx(zone
);
2857 * Builds allocation fallback zone lists.
2859 * Add all populated zones of a node to the zonelist.
2861 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
2862 int nr_zones
, enum zone_type zone_type
)
2866 BUG_ON(zone_type
>= MAX_NR_ZONES
);
2871 zone
= pgdat
->node_zones
+ zone_type
;
2872 if (populated_zone(zone
)) {
2873 zoneref_set_zone(zone
,
2874 &zonelist
->_zonerefs
[nr_zones
++]);
2875 check_highest_zone(zone_type
);
2878 } while (zone_type
);
2885 * 0 = automatic detection of better ordering.
2886 * 1 = order by ([node] distance, -zonetype)
2887 * 2 = order by (-zonetype, [node] distance)
2889 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
2890 * the same zonelist. So only NUMA can configure this param.
2892 #define ZONELIST_ORDER_DEFAULT 0
2893 #define ZONELIST_ORDER_NODE 1
2894 #define ZONELIST_ORDER_ZONE 2
2896 /* zonelist order in the kernel.
2897 * set_zonelist_order() will set this to NODE or ZONE.
2899 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2900 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
2904 /* The value user specified ....changed by config */
2905 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2906 /* string for sysctl */
2907 #define NUMA_ZONELIST_ORDER_LEN 16
2908 char numa_zonelist_order
[16] = "default";
2911 * interface for configure zonelist ordering.
2912 * command line option "numa_zonelist_order"
2913 * = "[dD]efault - default, automatic configuration.
2914 * = "[nN]ode - order by node locality, then by zone within node
2915 * = "[zZ]one - order by zone, then by locality within zone
2918 static int __parse_numa_zonelist_order(char *s
)
2920 if (*s
== 'd' || *s
== 'D') {
2921 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2922 } else if (*s
== 'n' || *s
== 'N') {
2923 user_zonelist_order
= ZONELIST_ORDER_NODE
;
2924 } else if (*s
== 'z' || *s
== 'Z') {
2925 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
2928 "Ignoring invalid numa_zonelist_order value: "
2935 static __init
int setup_numa_zonelist_order(char *s
)
2942 ret
= __parse_numa_zonelist_order(s
);
2944 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
2948 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
2951 * sysctl handler for numa_zonelist_order
2953 int numa_zonelist_order_handler(ctl_table
*table
, int write
,
2954 void __user
*buffer
, size_t *length
,
2957 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
2959 static DEFINE_MUTEX(zl_order_mutex
);
2961 mutex_lock(&zl_order_mutex
);
2963 strcpy(saved_string
, (char*)table
->data
);
2964 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
2968 int oldval
= user_zonelist_order
;
2969 if (__parse_numa_zonelist_order((char*)table
->data
)) {
2971 * bogus value. restore saved string
2973 strncpy((char*)table
->data
, saved_string
,
2974 NUMA_ZONELIST_ORDER_LEN
);
2975 user_zonelist_order
= oldval
;
2976 } else if (oldval
!= user_zonelist_order
) {
2977 mutex_lock(&zonelists_mutex
);
2978 build_all_zonelists(NULL
);
2979 mutex_unlock(&zonelists_mutex
);
2983 mutex_unlock(&zl_order_mutex
);
2988 #define MAX_NODE_LOAD (nr_online_nodes)
2989 static int node_load
[MAX_NUMNODES
];
2992 * find_next_best_node - find the next node that should appear in a given node's fallback list
2993 * @node: node whose fallback list we're appending
2994 * @used_node_mask: nodemask_t of already used nodes
2996 * We use a number of factors to determine which is the next node that should
2997 * appear on a given node's fallback list. The node should not have appeared
2998 * already in @node's fallback list, and it should be the next closest node
2999 * according to the distance array (which contains arbitrary distance values
3000 * from each node to each node in the system), and should also prefer nodes
3001 * with no CPUs, since presumably they'll have very little allocation pressure
3002 * on them otherwise.
3003 * It returns -1 if no node is found.
3005 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
3008 int min_val
= INT_MAX
;
3010 const struct cpumask
*tmp
= cpumask_of_node(0);
3012 /* Use the local node if we haven't already */
3013 if (!node_isset(node
, *used_node_mask
)) {
3014 node_set(node
, *used_node_mask
);
3018 for_each_node_state(n
, N_HIGH_MEMORY
) {
3020 /* Don't want a node to appear more than once */
3021 if (node_isset(n
, *used_node_mask
))
3024 /* Use the distance array to find the distance */
3025 val
= node_distance(node
, n
);
3027 /* Penalize nodes under us ("prefer the next node") */
3030 /* Give preference to headless and unused nodes */
3031 tmp
= cpumask_of_node(n
);
3032 if (!cpumask_empty(tmp
))
3033 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
3035 /* Slight preference for less loaded node */
3036 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
3037 val
+= node_load
[n
];
3039 if (val
< min_val
) {
3046 node_set(best_node
, *used_node_mask
);
3053 * Build zonelists ordered by node and zones within node.
3054 * This results in maximum locality--normal zone overflows into local
3055 * DMA zone, if any--but risks exhausting DMA zone.
3057 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
3060 struct zonelist
*zonelist
;
3062 zonelist
= &pgdat
->node_zonelists
[0];
3063 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
3065 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3067 zonelist
->_zonerefs
[j
].zone
= NULL
;
3068 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3072 * Build gfp_thisnode zonelists
3074 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
3077 struct zonelist
*zonelist
;
3079 zonelist
= &pgdat
->node_zonelists
[1];
3080 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
3081 zonelist
->_zonerefs
[j
].zone
= NULL
;
3082 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3086 * Build zonelists ordered by zone and nodes within zones.
3087 * This results in conserving DMA zone[s] until all Normal memory is
3088 * exhausted, but results in overflowing to remote node while memory
3089 * may still exist in local DMA zone.
3091 static int node_order
[MAX_NUMNODES
];
3093 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
3096 int zone_type
; /* needs to be signed */
3098 struct zonelist
*zonelist
;
3100 zonelist
= &pgdat
->node_zonelists
[0];
3102 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
3103 for (j
= 0; j
< nr_nodes
; j
++) {
3104 node
= node_order
[j
];
3105 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
3106 if (populated_zone(z
)) {
3108 &zonelist
->_zonerefs
[pos
++]);
3109 check_highest_zone(zone_type
);
3113 zonelist
->_zonerefs
[pos
].zone
= NULL
;
3114 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
3117 static int default_zonelist_order(void)
3120 unsigned long low_kmem_size
,total_size
;
3124 * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
3125 * If they are really small and used heavily, the system can fall
3126 * into OOM very easily.
3127 * This function detect ZONE_DMA/DMA32 size and configures zone order.
3129 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
3132 for_each_online_node(nid
) {
3133 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
3134 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
3135 if (populated_zone(z
)) {
3136 if (zone_type
< ZONE_NORMAL
)
3137 low_kmem_size
+= z
->present_pages
;
3138 total_size
+= z
->present_pages
;
3139 } else if (zone_type
== ZONE_NORMAL
) {
3141 * If any node has only lowmem, then node order
3142 * is preferred to allow kernel allocations
3143 * locally; otherwise, they can easily infringe
3144 * on other nodes when there is an abundance of
3145 * lowmem available to allocate from.
3147 return ZONELIST_ORDER_NODE
;
3151 if (!low_kmem_size
|| /* there are no DMA area. */
3152 low_kmem_size
> total_size
/2) /* DMA/DMA32 is big. */
3153 return ZONELIST_ORDER_NODE
;
3155 * look into each node's config.
3156 * If there is a node whose DMA/DMA32 memory is very big area on
3157 * local memory, NODE_ORDER may be suitable.
3159 average_size
= total_size
/
3160 (nodes_weight(node_states
[N_HIGH_MEMORY
]) + 1);
3161 for_each_online_node(nid
) {
3164 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
3165 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
3166 if (populated_zone(z
)) {
3167 if (zone_type
< ZONE_NORMAL
)
3168 low_kmem_size
+= z
->present_pages
;
3169 total_size
+= z
->present_pages
;
3172 if (low_kmem_size
&&
3173 total_size
> average_size
&& /* ignore small node */
3174 low_kmem_size
> total_size
* 70/100)
3175 return ZONELIST_ORDER_NODE
;
3177 return ZONELIST_ORDER_ZONE
;
3180 static void set_zonelist_order(void)
3182 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
3183 current_zonelist_order
= default_zonelist_order();
3185 current_zonelist_order
= user_zonelist_order
;
3188 static void build_zonelists(pg_data_t
*pgdat
)
3192 nodemask_t used_mask
;
3193 int local_node
, prev_node
;
3194 struct zonelist
*zonelist
;
3195 int order
= current_zonelist_order
;
3197 /* initialize zonelists */
3198 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
3199 zonelist
= pgdat
->node_zonelists
+ i
;
3200 zonelist
->_zonerefs
[0].zone
= NULL
;
3201 zonelist
->_zonerefs
[0].zone_idx
= 0;
3204 /* NUMA-aware ordering of nodes */
3205 local_node
= pgdat
->node_id
;
3206 load
= nr_online_nodes
;
3207 prev_node
= local_node
;
3208 nodes_clear(used_mask
);
3210 memset(node_order
, 0, sizeof(node_order
));
3213 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
3214 int distance
= node_distance(local_node
, node
);
3217 * If another node is sufficiently far away then it is better
3218 * to reclaim pages in a zone before going off node.
3220 if (distance
> RECLAIM_DISTANCE
)
3221 zone_reclaim_mode
= 1;
3224 * We don't want to pressure a particular node.
3225 * So adding penalty to the first node in same
3226 * distance group to make it round-robin.
3228 if (distance
!= node_distance(local_node
, prev_node
))
3229 node_load
[node
] = load
;
3233 if (order
== ZONELIST_ORDER_NODE
)
3234 build_zonelists_in_node_order(pgdat
, node
);
3236 node_order
[j
++] = node
; /* remember order */
3239 if (order
== ZONELIST_ORDER_ZONE
) {
3240 /* calculate node order -- i.e., DMA last! */
3241 build_zonelists_in_zone_order(pgdat
, j
);
3244 build_thisnode_zonelists(pgdat
);
3247 /* Construct the zonelist performance cache - see further mmzone.h */
3248 static void build_zonelist_cache(pg_data_t
*pgdat
)
3250 struct zonelist
*zonelist
;
3251 struct zonelist_cache
*zlc
;
3254 zonelist
= &pgdat
->node_zonelists
[0];
3255 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
3256 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
3257 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
3258 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
3261 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3263 * Return node id of node used for "local" allocations.
3264 * I.e., first node id of first zone in arg node's generic zonelist.
3265 * Used for initializing percpu 'numa_mem', which is used primarily
3266 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3268 int local_memory_node(int node
)
3272 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
3273 gfp_zone(GFP_KERNEL
),
3280 #else /* CONFIG_NUMA */
3282 static void set_zonelist_order(void)
3284 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
3287 static void build_zonelists(pg_data_t
*pgdat
)
3289 int node
, local_node
;
3291 struct zonelist
*zonelist
;
3293 local_node
= pgdat
->node_id
;
3295 zonelist
= &pgdat
->node_zonelists
[0];
3296 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
3299 * Now we build the zonelist so that it contains the zones
3300 * of all the other nodes.
3301 * We don't want to pressure a particular node, so when
3302 * building the zones for node N, we make sure that the
3303 * zones coming right after the local ones are those from
3304 * node N+1 (modulo N)
3306 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
3307 if (!node_online(node
))
3309 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3312 for (node
= 0; node
< local_node
; node
++) {
3313 if (!node_online(node
))
3315 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3319 zonelist
->_zonerefs
[j
].zone
= NULL
;
3320 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3323 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3324 static void build_zonelist_cache(pg_data_t
*pgdat
)
3326 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
3329 #endif /* CONFIG_NUMA */
3332 * Boot pageset table. One per cpu which is going to be used for all
3333 * zones and all nodes. The parameters will be set in such a way
3334 * that an item put on a list will immediately be handed over to
3335 * the buddy list. This is safe since pageset manipulation is done
3336 * with interrupts disabled.
3338 * The boot_pagesets must be kept even after bootup is complete for
3339 * unused processors and/or zones. They do play a role for bootstrapping
3340 * hotplugged processors.
3342 * zoneinfo_show() and maybe other functions do
3343 * not check if the processor is online before following the pageset pointer.
3344 * Other parts of the kernel may not check if the zone is available.
3346 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
3347 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
3348 static void setup_zone_pageset(struct zone
*zone
);
3351 * Global mutex to protect against size modification of zonelists
3352 * as well as to serialize pageset setup for the new populated zone.
3354 DEFINE_MUTEX(zonelists_mutex
);
3356 /* return values int ....just for stop_machine() */
3357 static __init_refok
int __build_all_zonelists(void *data
)
3363 memset(node_load
, 0, sizeof(node_load
));
3365 for_each_online_node(nid
) {
3366 pg_data_t
*pgdat
= NODE_DATA(nid
);
3368 build_zonelists(pgdat
);
3369 build_zonelist_cache(pgdat
);
3373 * Initialize the boot_pagesets that are going to be used
3374 * for bootstrapping processors. The real pagesets for
3375 * each zone will be allocated later when the per cpu
3376 * allocator is available.
3378 * boot_pagesets are used also for bootstrapping offline
3379 * cpus if the system is already booted because the pagesets
3380 * are needed to initialize allocators on a specific cpu too.
3381 * F.e. the percpu allocator needs the page allocator which
3382 * needs the percpu allocator in order to allocate its pagesets
3383 * (a chicken-egg dilemma).
3385 for_each_possible_cpu(cpu
) {
3386 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
3388 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3390 * We now know the "local memory node" for each node--
3391 * i.e., the node of the first zone in the generic zonelist.
3392 * Set up numa_mem percpu variable for on-line cpus. During
3393 * boot, only the boot cpu should be on-line; we'll init the
3394 * secondary cpus' numa_mem as they come on-line. During
3395 * node/memory hotplug, we'll fixup all on-line cpus.
3397 if (cpu_online(cpu
))
3398 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
3406 * Called with zonelists_mutex held always
3407 * unless system_state == SYSTEM_BOOTING.
3409 void __ref
build_all_zonelists(void *data
)
3411 set_zonelist_order();
3413 if (system_state
== SYSTEM_BOOTING
) {
3414 __build_all_zonelists(NULL
);
3415 mminit_verify_zonelist();
3416 cpuset_init_current_mems_allowed();
3418 /* we have to stop all cpus to guarantee there is no user
3420 #ifdef CONFIG_MEMORY_HOTPLUG
3422 setup_zone_pageset((struct zone
*)data
);
3424 stop_machine(__build_all_zonelists
, NULL
, NULL
);
3425 /* cpuset refresh routine should be here */
3427 vm_total_pages
= nr_free_pagecache_pages();
3429 * Disable grouping by mobility if the number of pages in the
3430 * system is too low to allow the mechanism to work. It would be
3431 * more accurate, but expensive to check per-zone. This check is
3432 * made on memory-hotadd so a system can start with mobility
3433 * disabled and enable it later
3435 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
3436 page_group_by_mobility_disabled
= 1;
3438 page_group_by_mobility_disabled
= 0;
3440 printk("Built %i zonelists in %s order, mobility grouping %s. "
3441 "Total pages: %ld\n",
3443 zonelist_order_name
[current_zonelist_order
],
3444 page_group_by_mobility_disabled
? "off" : "on",
3447 printk("Policy zone: %s\n", zone_names
[policy_zone
]);
3452 * Helper functions to size the waitqueue hash table.
3453 * Essentially these want to choose hash table sizes sufficiently
3454 * large so that collisions trying to wait on pages are rare.
3455 * But in fact, the number of active page waitqueues on typical
3456 * systems is ridiculously low, less than 200. So this is even
3457 * conservative, even though it seems large.
3459 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3460 * waitqueues, i.e. the size of the waitq table given the number of pages.
3462 #define PAGES_PER_WAITQUEUE 256
3464 #ifndef CONFIG_MEMORY_HOTPLUG
3465 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3467 unsigned long size
= 1;
3469 pages
/= PAGES_PER_WAITQUEUE
;
3471 while (size
< pages
)
3475 * Once we have dozens or even hundreds of threads sleeping
3476 * on IO we've got bigger problems than wait queue collision.
3477 * Limit the size of the wait table to a reasonable size.
3479 size
= min(size
, 4096UL);
3481 return max(size
, 4UL);
3485 * A zone's size might be changed by hot-add, so it is not possible to determine
3486 * a suitable size for its wait_table. So we use the maximum size now.
3488 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
3490 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
3491 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3492 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
3494 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3495 * or more by the traditional way. (See above). It equals:
3497 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
3498 * ia64(16K page size) : = ( 8G + 4M)byte.
3499 * powerpc (64K page size) : = (32G +16M)byte.
3501 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3508 * This is an integer logarithm so that shifts can be used later
3509 * to extract the more random high bits from the multiplicative
3510 * hash function before the remainder is taken.
3512 static inline unsigned long wait_table_bits(unsigned long size
)
3517 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
3520 * Check if a pageblock contains reserved pages
3522 static int pageblock_is_reserved(unsigned long start_pfn
, unsigned long end_pfn
)
3526 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
3527 if (!pfn_valid_within(pfn
) || PageReserved(pfn_to_page(pfn
)))
3534 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3535 * of blocks reserved is based on min_wmark_pages(zone). The memory within
3536 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3537 * higher will lead to a bigger reserve which will get freed as contiguous
3538 * blocks as reclaim kicks in
3540 static void setup_zone_migrate_reserve(struct zone
*zone
)
3542 unsigned long start_pfn
, pfn
, end_pfn
, block_end_pfn
;
3544 unsigned long block_migratetype
;
3548 * Get the start pfn, end pfn and the number of blocks to reserve
3549 * We have to be careful to be aligned to pageblock_nr_pages to
3550 * make sure that we always check pfn_valid for the first page in
3553 start_pfn
= zone
->zone_start_pfn
;
3554 end_pfn
= start_pfn
+ zone
->spanned_pages
;
3555 start_pfn
= roundup(start_pfn
, pageblock_nr_pages
);
3556 reserve
= roundup(min_wmark_pages(zone
), pageblock_nr_pages
) >>
3560 * Reserve blocks are generally in place to help high-order atomic
3561 * allocations that are short-lived. A min_free_kbytes value that
3562 * would result in more than 2 reserve blocks for atomic allocations
3563 * is assumed to be in place to help anti-fragmentation for the
3564 * future allocation of hugepages at runtime.
3566 reserve
= min(2, reserve
);
3568 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
3569 if (!pfn_valid(pfn
))
3571 page
= pfn_to_page(pfn
);
3573 /* Watch out for overlapping nodes */
3574 if (page_to_nid(page
) != zone_to_nid(zone
))
3577 block_migratetype
= get_pageblock_migratetype(page
);
3579 /* Only test what is necessary when the reserves are not met */
3582 * Blocks with reserved pages will never free, skip
3585 block_end_pfn
= min(pfn
+ pageblock_nr_pages
, end_pfn
);
3586 if (pageblock_is_reserved(pfn
, block_end_pfn
))
3589 /* If this block is reserved, account for it */
3590 if (block_migratetype
== MIGRATE_RESERVE
) {
3595 /* Suitable for reserving if this block is movable */
3596 if (block_migratetype
== MIGRATE_MOVABLE
) {
3597 set_pageblock_migratetype(page
,
3599 move_freepages_block(zone
, page
,
3607 * If the reserve is met and this is a previous reserved block,
3610 if (block_migratetype
== MIGRATE_RESERVE
) {
3611 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3612 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
3618 * Initially all pages are reserved - free ones are freed
3619 * up by free_all_bootmem() once the early boot process is
3620 * done. Non-atomic initialization, single-pass.
3622 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
3623 unsigned long start_pfn
, enum memmap_context context
)
3626 unsigned long end_pfn
= start_pfn
+ size
;
3630 if (highest_memmap_pfn
< end_pfn
- 1)
3631 highest_memmap_pfn
= end_pfn
- 1;
3633 z
= &NODE_DATA(nid
)->node_zones
[zone
];
3634 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
3636 * There can be holes in boot-time mem_map[]s
3637 * handed to this function. They do not
3638 * exist on hotplugged memory.
3640 if (context
== MEMMAP_EARLY
) {
3641 if (!early_pfn_valid(pfn
))
3643 if (!early_pfn_in_nid(pfn
, nid
))
3646 page
= pfn_to_page(pfn
);
3647 set_page_links(page
, zone
, nid
, pfn
);
3648 mminit_verify_page_links(page
, zone
, nid
, pfn
);
3649 init_page_count(page
);
3650 reset_page_mapcount(page
);
3651 SetPageReserved(page
);
3653 * Mark the block movable so that blocks are reserved for
3654 * movable at startup. This will force kernel allocations
3655 * to reserve their blocks rather than leaking throughout
3656 * the address space during boot when many long-lived
3657 * kernel allocations are made. Later some blocks near
3658 * the start are marked MIGRATE_RESERVE by
3659 * setup_zone_migrate_reserve()
3661 * bitmap is created for zone's valid pfn range. but memmap
3662 * can be created for invalid pages (for alignment)
3663 * check here not to call set_pageblock_migratetype() against
3666 if ((z
->zone_start_pfn
<= pfn
)
3667 && (pfn
< z
->zone_start_pfn
+ z
->spanned_pages
)
3668 && !(pfn
& (pageblock_nr_pages
- 1)))
3669 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3671 INIT_LIST_HEAD(&page
->lru
);
3672 #ifdef WANT_PAGE_VIRTUAL
3673 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
3674 if (!is_highmem_idx(zone
))
3675 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
3680 static void __meminit
zone_init_free_lists(struct zone
*zone
)
3683 for_each_migratetype_order(order
, t
) {
3684 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
3685 zone
->free_area
[order
].nr_free
= 0;
3689 #ifndef __HAVE_ARCH_MEMMAP_INIT
3690 #define memmap_init(size, nid, zone, start_pfn) \
3691 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
3694 static int zone_batchsize(struct zone
*zone
)
3700 * The per-cpu-pages pools are set to around 1000th of the
3701 * size of the zone. But no more than 1/2 of a meg.
3703 * OK, so we don't know how big the cache is. So guess.
3705 batch
= zone
->present_pages
/ 1024;
3706 if (batch
* PAGE_SIZE
> 512 * 1024)
3707 batch
= (512 * 1024) / PAGE_SIZE
;
3708 batch
/= 4; /* We effectively *= 4 below */
3713 * Clamp the batch to a 2^n - 1 value. Having a power
3714 * of 2 value was found to be more likely to have
3715 * suboptimal cache aliasing properties in some cases.
3717 * For example if 2 tasks are alternately allocating
3718 * batches of pages, one task can end up with a lot
3719 * of pages of one half of the possible page colors
3720 * and the other with pages of the other colors.
3722 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
3727 /* The deferral and batching of frees should be suppressed under NOMMU
3730 * The problem is that NOMMU needs to be able to allocate large chunks
3731 * of contiguous memory as there's no hardware page translation to
3732 * assemble apparent contiguous memory from discontiguous pages.
3734 * Queueing large contiguous runs of pages for batching, however,
3735 * causes the pages to actually be freed in smaller chunks. As there
3736 * can be a significant delay between the individual batches being
3737 * recycled, this leads to the once large chunks of space being
3738 * fragmented and becoming unavailable for high-order allocations.
3744 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
3746 struct per_cpu_pages
*pcp
;
3749 memset(p
, 0, sizeof(*p
));
3753 pcp
->high
= 6 * batch
;
3754 pcp
->batch
= max(1UL, 1 * batch
);
3755 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
3756 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
3760 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
3761 * to the value high for the pageset p.
3764 static void setup_pagelist_highmark(struct per_cpu_pageset
*p
,
3767 struct per_cpu_pages
*pcp
;
3771 pcp
->batch
= max(1UL, high
/4);
3772 if ((high
/4) > (PAGE_SHIFT
* 8))
3773 pcp
->batch
= PAGE_SHIFT
* 8;
3776 static void setup_zone_pageset(struct zone
*zone
)
3780 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
3782 for_each_possible_cpu(cpu
) {
3783 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
3785 setup_pageset(pcp
, zone_batchsize(zone
));
3787 if (percpu_pagelist_fraction
)
3788 setup_pagelist_highmark(pcp
,
3789 (zone
->present_pages
/
3790 percpu_pagelist_fraction
));
3795 * Allocate per cpu pagesets and initialize them.
3796 * Before this call only boot pagesets were available.
3798 void __init
setup_per_cpu_pageset(void)
3802 for_each_populated_zone(zone
)
3803 setup_zone_pageset(zone
);
3806 static noinline __init_refok
3807 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
3810 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
3814 * The per-page waitqueue mechanism uses hashed waitqueues
3817 zone
->wait_table_hash_nr_entries
=
3818 wait_table_hash_nr_entries(zone_size_pages
);
3819 zone
->wait_table_bits
=
3820 wait_table_bits(zone
->wait_table_hash_nr_entries
);
3821 alloc_size
= zone
->wait_table_hash_nr_entries
3822 * sizeof(wait_queue_head_t
);
3824 if (!slab_is_available()) {
3825 zone
->wait_table
= (wait_queue_head_t
*)
3826 alloc_bootmem_node_nopanic(pgdat
, alloc_size
);
3829 * This case means that a zone whose size was 0 gets new memory
3830 * via memory hot-add.
3831 * But it may be the case that a new node was hot-added. In
3832 * this case vmalloc() will not be able to use this new node's
3833 * memory - this wait_table must be initialized to use this new
3834 * node itself as well.
3835 * To use this new node's memory, further consideration will be
3838 zone
->wait_table
= vmalloc(alloc_size
);
3840 if (!zone
->wait_table
)
3843 for(i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
3844 init_waitqueue_head(zone
->wait_table
+ i
);
3849 static int __zone_pcp_update(void *data
)
3851 struct zone
*zone
= data
;
3853 unsigned long batch
= zone_batchsize(zone
), flags
;
3855 for_each_possible_cpu(cpu
) {
3856 struct per_cpu_pageset
*pset
;
3857 struct per_cpu_pages
*pcp
;
3859 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
3862 local_irq_save(flags
);
3863 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
3864 setup_pageset(pset
, batch
);
3865 local_irq_restore(flags
);
3870 void zone_pcp_update(struct zone
*zone
)
3872 stop_machine(__zone_pcp_update
, zone
, NULL
);
3875 static __meminit
void zone_pcp_init(struct zone
*zone
)
3878 * per cpu subsystem is not up at this point. The following code
3879 * relies on the ability of the linker to provide the
3880 * offset of a (static) per cpu variable into the per cpu area.
3882 zone
->pageset
= &boot_pageset
;
3884 if (zone
->present_pages
)
3885 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
3886 zone
->name
, zone
->present_pages
,
3887 zone_batchsize(zone
));
3890 __meminit
int init_currently_empty_zone(struct zone
*zone
,
3891 unsigned long zone_start_pfn
,
3893 enum memmap_context context
)
3895 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
3897 ret
= zone_wait_table_init(zone
, size
);
3900 pgdat
->nr_zones
= zone_idx(zone
) + 1;
3902 zone
->zone_start_pfn
= zone_start_pfn
;
3904 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
3905 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
3907 (unsigned long)zone_idx(zone
),
3908 zone_start_pfn
, (zone_start_pfn
+ size
));
3910 zone_init_free_lists(zone
);
3915 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
3916 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
3918 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
3919 * Architectures may implement their own version but if add_active_range()
3920 * was used and there are no special requirements, this is a convenient
3923 int __meminit
__early_pfn_to_nid(unsigned long pfn
)
3925 unsigned long start_pfn
, end_pfn
;
3928 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
3929 if (start_pfn
<= pfn
&& pfn
< end_pfn
)
3931 /* This is a memory hole */
3934 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
3936 int __meminit
early_pfn_to_nid(unsigned long pfn
)
3940 nid
= __early_pfn_to_nid(pfn
);
3943 /* just returns 0 */
3947 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
3948 bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
3952 nid
= __early_pfn_to_nid(pfn
);
3953 if (nid
>= 0 && nid
!= node
)
3960 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
3961 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
3962 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
3964 * If an architecture guarantees that all ranges registered with
3965 * add_active_ranges() contain no holes and may be freed, this
3966 * this function may be used instead of calling free_bootmem() manually.
3968 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
3970 unsigned long start_pfn
, end_pfn
;
3973 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
3974 start_pfn
= min(start_pfn
, max_low_pfn
);
3975 end_pfn
= min(end_pfn
, max_low_pfn
);
3977 if (start_pfn
< end_pfn
)
3978 free_bootmem_node(NODE_DATA(this_nid
),
3979 PFN_PHYS(start_pfn
),
3980 (end_pfn
- start_pfn
) << PAGE_SHIFT
);
3985 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3986 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3988 * If an architecture guarantees that all ranges registered with
3989 * add_active_ranges() contain no holes and may be freed, this
3990 * function may be used instead of calling memory_present() manually.
3992 void __init
sparse_memory_present_with_active_regions(int nid
)
3994 unsigned long start_pfn
, end_pfn
;
3997 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
3998 memory_present(this_nid
, start_pfn
, end_pfn
);
4002 * get_pfn_range_for_nid - Return the start and end page frames for a node
4003 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4004 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
4005 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
4007 * It returns the start and end page frame of a node based on information
4008 * provided by an arch calling add_active_range(). If called for a node
4009 * with no available memory, a warning is printed and the start and end
4012 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
4013 unsigned long *start_pfn
, unsigned long *end_pfn
)
4015 unsigned long this_start_pfn
, this_end_pfn
;
4021 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
4022 *start_pfn
= min(*start_pfn
, this_start_pfn
);
4023 *end_pfn
= max(*end_pfn
, this_end_pfn
);
4026 if (*start_pfn
== -1UL)
4031 * This finds a zone that can be used for ZONE_MOVABLE pages. The
4032 * assumption is made that zones within a node are ordered in monotonic
4033 * increasing memory addresses so that the "highest" populated zone is used
4035 static void __init
find_usable_zone_for_movable(void)
4038 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
4039 if (zone_index
== ZONE_MOVABLE
)
4042 if (arch_zone_highest_possible_pfn
[zone_index
] >
4043 arch_zone_lowest_possible_pfn
[zone_index
])
4047 VM_BUG_ON(zone_index
== -1);
4048 movable_zone
= zone_index
;
4052 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4053 * because it is sized independent of architecture. Unlike the other zones,
4054 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4055 * in each node depending on the size of each node and how evenly kernelcore
4056 * is distributed. This helper function adjusts the zone ranges
4057 * provided by the architecture for a given node by using the end of the
4058 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4059 * zones within a node are in order of monotonic increases memory addresses
4061 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
4062 unsigned long zone_type
,
4063 unsigned long node_start_pfn
,
4064 unsigned long node_end_pfn
,
4065 unsigned long *zone_start_pfn
,
4066 unsigned long *zone_end_pfn
)
4068 /* Only adjust if ZONE_MOVABLE is on this node */
4069 if (zone_movable_pfn
[nid
]) {
4070 /* Size ZONE_MOVABLE */
4071 if (zone_type
== ZONE_MOVABLE
) {
4072 *zone_start_pfn
= zone_movable_pfn
[nid
];
4073 *zone_end_pfn
= min(node_end_pfn
,
4074 arch_zone_highest_possible_pfn
[movable_zone
]);
4076 /* Adjust for ZONE_MOVABLE starting within this range */
4077 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
4078 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
4079 *zone_end_pfn
= zone_movable_pfn
[nid
];
4081 /* Check if this whole range is within ZONE_MOVABLE */
4082 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
4083 *zone_start_pfn
= *zone_end_pfn
;
4088 * Return the number of pages a zone spans in a node, including holes
4089 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4091 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4092 unsigned long zone_type
,
4093 unsigned long *ignored
)
4095 unsigned long node_start_pfn
, node_end_pfn
;
4096 unsigned long zone_start_pfn
, zone_end_pfn
;
4098 /* Get the start and end of the node and zone */
4099 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
4100 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
4101 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
4102 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4103 node_start_pfn
, node_end_pfn
,
4104 &zone_start_pfn
, &zone_end_pfn
);
4106 /* Check that this node has pages within the zone's required range */
4107 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
4110 /* Move the zone boundaries inside the node if necessary */
4111 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
4112 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
4114 /* Return the spanned pages */
4115 return zone_end_pfn
- zone_start_pfn
;
4119 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4120 * then all holes in the requested range will be accounted for.
4122 unsigned long __meminit
__absent_pages_in_range(int nid
,
4123 unsigned long range_start_pfn
,
4124 unsigned long range_end_pfn
)
4126 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
4127 unsigned long start_pfn
, end_pfn
;
4130 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
4131 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
4132 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
4133 nr_absent
-= end_pfn
- start_pfn
;
4139 * absent_pages_in_range - Return number of page frames in holes within a range
4140 * @start_pfn: The start PFN to start searching for holes
4141 * @end_pfn: The end PFN to stop searching for holes
4143 * It returns the number of pages frames in memory holes within a range.
4145 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
4146 unsigned long end_pfn
)
4148 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
4151 /* Return the number of page frames in holes in a zone on a node */
4152 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4153 unsigned long zone_type
,
4154 unsigned long *ignored
)
4156 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
4157 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
4158 unsigned long node_start_pfn
, node_end_pfn
;
4159 unsigned long zone_start_pfn
, zone_end_pfn
;
4161 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
4162 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
4163 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
4165 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4166 node_start_pfn
, node_end_pfn
,
4167 &zone_start_pfn
, &zone_end_pfn
);
4168 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
4171 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4172 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4173 unsigned long zone_type
,
4174 unsigned long *zones_size
)
4176 return zones_size
[zone_type
];
4179 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4180 unsigned long zone_type
,
4181 unsigned long *zholes_size
)
4186 return zholes_size
[zone_type
];
4189 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4191 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
4192 unsigned long *zones_size
, unsigned long *zholes_size
)
4194 unsigned long realtotalpages
, totalpages
= 0;
4197 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4198 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
4200 pgdat
->node_spanned_pages
= totalpages
;
4202 realtotalpages
= totalpages
;
4203 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4205 zone_absent_pages_in_node(pgdat
->node_id
, i
,
4207 pgdat
->node_present_pages
= realtotalpages
;
4208 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
4212 #ifndef CONFIG_SPARSEMEM
4214 * Calculate the size of the zone->blockflags rounded to an unsigned long
4215 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4216 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4217 * round what is now in bits to nearest long in bits, then return it in
4220 static unsigned long __init
usemap_size(unsigned long zonesize
)
4222 unsigned long usemapsize
;
4224 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
4225 usemapsize
= usemapsize
>> pageblock_order
;
4226 usemapsize
*= NR_PAGEBLOCK_BITS
;
4227 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
4229 return usemapsize
/ 8;
4232 static void __init
setup_usemap(struct pglist_data
*pgdat
,
4233 struct zone
*zone
, unsigned long zonesize
)
4235 unsigned long usemapsize
= usemap_size(zonesize
);
4236 zone
->pageblock_flags
= NULL
;
4238 zone
->pageblock_flags
= alloc_bootmem_node_nopanic(pgdat
,
4242 static inline void setup_usemap(struct pglist_data
*pgdat
,
4243 struct zone
*zone
, unsigned long zonesize
) {}
4244 #endif /* CONFIG_SPARSEMEM */
4246 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4248 /* Return a sensible default order for the pageblock size. */
4249 static inline int pageblock_default_order(void)
4251 if (HPAGE_SHIFT
> PAGE_SHIFT
)
4252 return HUGETLB_PAGE_ORDER
;
4257 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4258 static inline void __init
set_pageblock_order(unsigned int order
)
4260 /* Check that pageblock_nr_pages has not already been setup */
4261 if (pageblock_order
)
4265 * Assume the largest contiguous order of interest is a huge page.
4266 * This value may be variable depending on boot parameters on IA64
4268 pageblock_order
= order
;
4270 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4273 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4274 * and pageblock_default_order() are unused as pageblock_order is set
4275 * at compile-time. See include/linux/pageblock-flags.h for the values of
4276 * pageblock_order based on the kernel config
4278 static inline int pageblock_default_order(unsigned int order
)
4282 #define set_pageblock_order(x) do {} while (0)
4284 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4287 * Set up the zone data structures:
4288 * - mark all pages reserved
4289 * - mark all memory queues empty
4290 * - clear the memory bitmaps
4292 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
,
4293 unsigned long *zones_size
, unsigned long *zholes_size
)
4296 int nid
= pgdat
->node_id
;
4297 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
4300 pgdat_resize_init(pgdat
);
4301 pgdat
->nr_zones
= 0;
4302 init_waitqueue_head(&pgdat
->kswapd_wait
);
4303 pgdat
->kswapd_max_order
= 0;
4304 pgdat_page_cgroup_init(pgdat
);
4306 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4307 struct zone
*zone
= pgdat
->node_zones
+ j
;
4308 unsigned long size
, realsize
, memmap_pages
;
4311 size
= zone_spanned_pages_in_node(nid
, j
, zones_size
);
4312 realsize
= size
- zone_absent_pages_in_node(nid
, j
,
4316 * Adjust realsize so that it accounts for how much memory
4317 * is used by this zone for memmap. This affects the watermark
4318 * and per-cpu initialisations
4321 PAGE_ALIGN(size
* sizeof(struct page
)) >> PAGE_SHIFT
;
4322 if (realsize
>= memmap_pages
) {
4323 realsize
-= memmap_pages
;
4326 " %s zone: %lu pages used for memmap\n",
4327 zone_names
[j
], memmap_pages
);
4330 " %s zone: %lu pages exceeds realsize %lu\n",
4331 zone_names
[j
], memmap_pages
, realsize
);
4333 /* Account for reserved pages */
4334 if (j
== 0 && realsize
> dma_reserve
) {
4335 realsize
-= dma_reserve
;
4336 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
4337 zone_names
[0], dma_reserve
);
4340 if (!is_highmem_idx(j
))
4341 nr_kernel_pages
+= realsize
;
4342 nr_all_pages
+= realsize
;
4344 zone
->spanned_pages
= size
;
4345 zone
->present_pages
= realsize
;
4348 zone
->min_unmapped_pages
= (realsize
*sysctl_min_unmapped_ratio
)
4350 zone
->min_slab_pages
= (realsize
* sysctl_min_slab_ratio
) / 100;
4352 zone
->name
= zone_names
[j
];
4353 spin_lock_init(&zone
->lock
);
4354 spin_lock_init(&zone
->lru_lock
);
4355 zone_seqlock_init(zone
);
4356 zone
->zone_pgdat
= pgdat
;
4358 zone_pcp_init(zone
);
4360 INIT_LIST_HEAD(&zone
->lruvec
.lists
[lru
]);
4361 zone
->reclaim_stat
.recent_rotated
[0] = 0;
4362 zone
->reclaim_stat
.recent_rotated
[1] = 0;
4363 zone
->reclaim_stat
.recent_scanned
[0] = 0;
4364 zone
->reclaim_stat
.recent_scanned
[1] = 0;
4365 zap_zone_vm_stats(zone
);
4370 set_pageblock_order(pageblock_default_order());
4371 setup_usemap(pgdat
, zone
, size
);
4372 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
4373 size
, MEMMAP_EARLY
);
4375 memmap_init(size
, nid
, j
, zone_start_pfn
);
4376 zone_start_pfn
+= size
;
4380 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
4382 /* Skip empty nodes */
4383 if (!pgdat
->node_spanned_pages
)
4386 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4387 /* ia64 gets its own node_mem_map, before this, without bootmem */
4388 if (!pgdat
->node_mem_map
) {
4389 unsigned long size
, start
, end
;
4393 * The zone's endpoints aren't required to be MAX_ORDER
4394 * aligned but the node_mem_map endpoints must be in order
4395 * for the buddy allocator to function correctly.
4397 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
4398 end
= pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
4399 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
4400 size
= (end
- start
) * sizeof(struct page
);
4401 map
= alloc_remap(pgdat
->node_id
, size
);
4403 map
= alloc_bootmem_node_nopanic(pgdat
, size
);
4404 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
4406 #ifndef CONFIG_NEED_MULTIPLE_NODES
4408 * With no DISCONTIG, the global mem_map is just set as node 0's
4410 if (pgdat
== NODE_DATA(0)) {
4411 mem_map
= NODE_DATA(0)->node_mem_map
;
4412 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4413 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
4414 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
4415 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4418 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4421 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
4422 unsigned long node_start_pfn
, unsigned long *zholes_size
)
4424 pg_data_t
*pgdat
= NODE_DATA(nid
);
4426 pgdat
->node_id
= nid
;
4427 pgdat
->node_start_pfn
= node_start_pfn
;
4428 calculate_node_totalpages(pgdat
, zones_size
, zholes_size
);
4430 alloc_node_mem_map(pgdat
);
4431 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4432 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
4433 nid
, (unsigned long)pgdat
,
4434 (unsigned long)pgdat
->node_mem_map
);
4437 free_area_init_core(pgdat
, zones_size
, zholes_size
);
4440 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4442 #if MAX_NUMNODES > 1
4444 * Figure out the number of possible node ids.
4446 static void __init
setup_nr_node_ids(void)
4449 unsigned int highest
= 0;
4451 for_each_node_mask(node
, node_possible_map
)
4453 nr_node_ids
= highest
+ 1;
4456 static inline void setup_nr_node_ids(void)
4462 * node_map_pfn_alignment - determine the maximum internode alignment
4464 * This function should be called after node map is populated and sorted.
4465 * It calculates the maximum power of two alignment which can distinguish
4468 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
4469 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
4470 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
4471 * shifted, 1GiB is enough and this function will indicate so.
4473 * This is used to test whether pfn -> nid mapping of the chosen memory
4474 * model has fine enough granularity to avoid incorrect mapping for the
4475 * populated node map.
4477 * Returns the determined alignment in pfn's. 0 if there is no alignment
4478 * requirement (single node).
4480 unsigned long __init
node_map_pfn_alignment(void)
4482 unsigned long accl_mask
= 0, last_end
= 0;
4483 unsigned long start
, end
, mask
;
4487 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
4488 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
4495 * Start with a mask granular enough to pin-point to the
4496 * start pfn and tick off bits one-by-one until it becomes
4497 * too coarse to separate the current node from the last.
4499 mask
= ~((1 << __ffs(start
)) - 1);
4500 while (mask
&& last_end
<= (start
& (mask
<< 1)))
4503 /* accumulate all internode masks */
4507 /* convert mask to number of pages */
4508 return ~accl_mask
+ 1;
4511 /* Find the lowest pfn for a node */
4512 static unsigned long __init
find_min_pfn_for_node(int nid
)
4514 unsigned long min_pfn
= ULONG_MAX
;
4515 unsigned long start_pfn
;
4518 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
4519 min_pfn
= min(min_pfn
, start_pfn
);
4521 if (min_pfn
== ULONG_MAX
) {
4523 "Could not find start_pfn for node %d\n", nid
);
4531 * find_min_pfn_with_active_regions - Find the minimum PFN registered
4533 * It returns the minimum PFN based on information provided via
4534 * add_active_range().
4536 unsigned long __init
find_min_pfn_with_active_regions(void)
4538 return find_min_pfn_for_node(MAX_NUMNODES
);
4542 * early_calculate_totalpages()
4543 * Sum pages in active regions for movable zone.
4544 * Populate N_HIGH_MEMORY for calculating usable_nodes.
4546 static unsigned long __init
early_calculate_totalpages(void)
4548 unsigned long totalpages
= 0;
4549 unsigned long start_pfn
, end_pfn
;
4552 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
4553 unsigned long pages
= end_pfn
- start_pfn
;
4555 totalpages
+= pages
;
4557 node_set_state(nid
, N_HIGH_MEMORY
);
4563 * Find the PFN the Movable zone begins in each node. Kernel memory
4564 * is spread evenly between nodes as long as the nodes have enough
4565 * memory. When they don't, some nodes will have more kernelcore than
4568 static void __init
find_zone_movable_pfns_for_nodes(void)
4571 unsigned long usable_startpfn
;
4572 unsigned long kernelcore_node
, kernelcore_remaining
;
4573 /* save the state before borrow the nodemask */
4574 nodemask_t saved_node_state
= node_states
[N_HIGH_MEMORY
];
4575 unsigned long totalpages
= early_calculate_totalpages();
4576 int usable_nodes
= nodes_weight(node_states
[N_HIGH_MEMORY
]);
4579 * If movablecore was specified, calculate what size of
4580 * kernelcore that corresponds so that memory usable for
4581 * any allocation type is evenly spread. If both kernelcore
4582 * and movablecore are specified, then the value of kernelcore
4583 * will be used for required_kernelcore if it's greater than
4584 * what movablecore would have allowed.
4586 if (required_movablecore
) {
4587 unsigned long corepages
;
4590 * Round-up so that ZONE_MOVABLE is at least as large as what
4591 * was requested by the user
4593 required_movablecore
=
4594 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
4595 corepages
= totalpages
- required_movablecore
;
4597 required_kernelcore
= max(required_kernelcore
, corepages
);
4600 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
4601 if (!required_kernelcore
)
4604 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
4605 find_usable_zone_for_movable();
4606 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
4609 /* Spread kernelcore memory as evenly as possible throughout nodes */
4610 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4611 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4612 unsigned long start_pfn
, end_pfn
;
4615 * Recalculate kernelcore_node if the division per node
4616 * now exceeds what is necessary to satisfy the requested
4617 * amount of memory for the kernel
4619 if (required_kernelcore
< kernelcore_node
)
4620 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4623 * As the map is walked, we track how much memory is usable
4624 * by the kernel using kernelcore_remaining. When it is
4625 * 0, the rest of the node is usable by ZONE_MOVABLE
4627 kernelcore_remaining
= kernelcore_node
;
4629 /* Go through each range of PFNs within this node */
4630 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
4631 unsigned long size_pages
;
4633 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
4634 if (start_pfn
>= end_pfn
)
4637 /* Account for what is only usable for kernelcore */
4638 if (start_pfn
< usable_startpfn
) {
4639 unsigned long kernel_pages
;
4640 kernel_pages
= min(end_pfn
, usable_startpfn
)
4643 kernelcore_remaining
-= min(kernel_pages
,
4644 kernelcore_remaining
);
4645 required_kernelcore
-= min(kernel_pages
,
4646 required_kernelcore
);
4648 /* Continue if range is now fully accounted */
4649 if (end_pfn
<= usable_startpfn
) {
4652 * Push zone_movable_pfn to the end so
4653 * that if we have to rebalance
4654 * kernelcore across nodes, we will
4655 * not double account here
4657 zone_movable_pfn
[nid
] = end_pfn
;
4660 start_pfn
= usable_startpfn
;
4664 * The usable PFN range for ZONE_MOVABLE is from
4665 * start_pfn->end_pfn. Calculate size_pages as the
4666 * number of pages used as kernelcore
4668 size_pages
= end_pfn
- start_pfn
;
4669 if (size_pages
> kernelcore_remaining
)
4670 size_pages
= kernelcore_remaining
;
4671 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
4674 * Some kernelcore has been met, update counts and
4675 * break if the kernelcore for this node has been
4678 required_kernelcore
-= min(required_kernelcore
,
4680 kernelcore_remaining
-= size_pages
;
4681 if (!kernelcore_remaining
)
4687 * If there is still required_kernelcore, we do another pass with one
4688 * less node in the count. This will push zone_movable_pfn[nid] further
4689 * along on the nodes that still have memory until kernelcore is
4693 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
4696 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
4697 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
4698 zone_movable_pfn
[nid
] =
4699 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
4702 /* restore the node_state */
4703 node_states
[N_HIGH_MEMORY
] = saved_node_state
;
4706 /* Any regular memory on that node ? */
4707 static void check_for_regular_memory(pg_data_t
*pgdat
)
4709 #ifdef CONFIG_HIGHMEM
4710 enum zone_type zone_type
;
4712 for (zone_type
= 0; zone_type
<= ZONE_NORMAL
; zone_type
++) {
4713 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4714 if (zone
->present_pages
) {
4715 node_set_state(zone_to_nid(zone
), N_NORMAL_MEMORY
);
4723 * free_area_init_nodes - Initialise all pg_data_t and zone data
4724 * @max_zone_pfn: an array of max PFNs for each zone
4726 * This will call free_area_init_node() for each active node in the system.
4727 * Using the page ranges provided by add_active_range(), the size of each
4728 * zone in each node and their holes is calculated. If the maximum PFN
4729 * between two adjacent zones match, it is assumed that the zone is empty.
4730 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
4731 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
4732 * starts where the previous one ended. For example, ZONE_DMA32 starts
4733 * at arch_max_dma_pfn.
4735 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
4737 unsigned long start_pfn
, end_pfn
;
4740 /* Record where the zone boundaries are */
4741 memset(arch_zone_lowest_possible_pfn
, 0,
4742 sizeof(arch_zone_lowest_possible_pfn
));
4743 memset(arch_zone_highest_possible_pfn
, 0,
4744 sizeof(arch_zone_highest_possible_pfn
));
4745 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
4746 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
4747 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
4748 if (i
== ZONE_MOVABLE
)
4750 arch_zone_lowest_possible_pfn
[i
] =
4751 arch_zone_highest_possible_pfn
[i
-1];
4752 arch_zone_highest_possible_pfn
[i
] =
4753 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
4755 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
4756 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
4758 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
4759 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
4760 find_zone_movable_pfns_for_nodes();
4762 /* Print out the zone ranges */
4763 printk("Zone PFN ranges:\n");
4764 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4765 if (i
== ZONE_MOVABLE
)
4767 printk(" %-8s ", zone_names
[i
]);
4768 if (arch_zone_lowest_possible_pfn
[i
] ==
4769 arch_zone_highest_possible_pfn
[i
])
4772 printk("%0#10lx -> %0#10lx\n",
4773 arch_zone_lowest_possible_pfn
[i
],
4774 arch_zone_highest_possible_pfn
[i
]);
4777 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
4778 printk("Movable zone start PFN for each node\n");
4779 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
4780 if (zone_movable_pfn
[i
])
4781 printk(" Node %d: %lu\n", i
, zone_movable_pfn
[i
]);
4784 /* Print out the early_node_map[] */
4785 printk("Early memory PFN ranges\n");
4786 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
4787 printk(" %3d: %0#10lx -> %0#10lx\n", nid
, start_pfn
, end_pfn
);
4789 /* Initialise every node */
4790 mminit_verify_pageflags_layout();
4791 setup_nr_node_ids();
4792 for_each_online_node(nid
) {
4793 pg_data_t
*pgdat
= NODE_DATA(nid
);
4794 free_area_init_node(nid
, NULL
,
4795 find_min_pfn_for_node(nid
), NULL
);
4797 /* Any memory on that node */
4798 if (pgdat
->node_present_pages
)
4799 node_set_state(nid
, N_HIGH_MEMORY
);
4800 check_for_regular_memory(pgdat
);
4804 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
4806 unsigned long long coremem
;
4810 coremem
= memparse(p
, &p
);
4811 *core
= coremem
>> PAGE_SHIFT
;
4813 /* Paranoid check that UL is enough for the coremem value */
4814 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
4820 * kernelcore=size sets the amount of memory for use for allocations that
4821 * cannot be reclaimed or migrated.
4823 static int __init
cmdline_parse_kernelcore(char *p
)
4825 return cmdline_parse_core(p
, &required_kernelcore
);
4829 * movablecore=size sets the amount of memory for use for allocations that
4830 * can be reclaimed or migrated.
4832 static int __init
cmdline_parse_movablecore(char *p
)
4834 return cmdline_parse_core(p
, &required_movablecore
);
4837 early_param("kernelcore", cmdline_parse_kernelcore
);
4838 early_param("movablecore", cmdline_parse_movablecore
);
4840 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4843 * set_dma_reserve - set the specified number of pages reserved in the first zone
4844 * @new_dma_reserve: The number of pages to mark reserved
4846 * The per-cpu batchsize and zone watermarks are determined by present_pages.
4847 * In the DMA zone, a significant percentage may be consumed by kernel image
4848 * and other unfreeable allocations which can skew the watermarks badly. This
4849 * function may optionally be used to account for unfreeable pages in the
4850 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
4851 * smaller per-cpu batchsize.
4853 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
4855 dma_reserve
= new_dma_reserve
;
4858 void __init
free_area_init(unsigned long *zones_size
)
4860 free_area_init_node(0, zones_size
,
4861 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
4864 static int page_alloc_cpu_notify(struct notifier_block
*self
,
4865 unsigned long action
, void *hcpu
)
4867 int cpu
= (unsigned long)hcpu
;
4869 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
4870 lru_add_drain_cpu(cpu
);
4874 * Spill the event counters of the dead processor
4875 * into the current processors event counters.
4876 * This artificially elevates the count of the current
4879 vm_events_fold_cpu(cpu
);
4882 * Zero the differential counters of the dead processor
4883 * so that the vm statistics are consistent.
4885 * This is only okay since the processor is dead and cannot
4886 * race with what we are doing.
4888 refresh_cpu_vm_stats(cpu
);
4893 void __init
page_alloc_init(void)
4895 hotcpu_notifier(page_alloc_cpu_notify
, 0);
4899 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
4900 * or min_free_kbytes changes.
4902 static void calculate_totalreserve_pages(void)
4904 struct pglist_data
*pgdat
;
4905 unsigned long reserve_pages
= 0;
4906 enum zone_type i
, j
;
4908 for_each_online_pgdat(pgdat
) {
4909 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4910 struct zone
*zone
= pgdat
->node_zones
+ i
;
4911 unsigned long max
= 0;
4913 /* Find valid and maximum lowmem_reserve in the zone */
4914 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
4915 if (zone
->lowmem_reserve
[j
] > max
)
4916 max
= zone
->lowmem_reserve
[j
];
4919 /* we treat the high watermark as reserved pages. */
4920 max
+= high_wmark_pages(zone
);
4922 if (max
> zone
->present_pages
)
4923 max
= zone
->present_pages
;
4924 reserve_pages
+= max
;
4926 * Lowmem reserves are not available to
4927 * GFP_HIGHUSER page cache allocations and
4928 * kswapd tries to balance zones to their high
4929 * watermark. As a result, neither should be
4930 * regarded as dirtyable memory, to prevent a
4931 * situation where reclaim has to clean pages
4932 * in order to balance the zones.
4934 zone
->dirty_balance_reserve
= max
;
4937 dirty_balance_reserve
= reserve_pages
;
4938 totalreserve_pages
= reserve_pages
;
4942 * setup_per_zone_lowmem_reserve - called whenever
4943 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
4944 * has a correct pages reserved value, so an adequate number of
4945 * pages are left in the zone after a successful __alloc_pages().
4947 static void setup_per_zone_lowmem_reserve(void)
4949 struct pglist_data
*pgdat
;
4950 enum zone_type j
, idx
;
4952 for_each_online_pgdat(pgdat
) {
4953 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4954 struct zone
*zone
= pgdat
->node_zones
+ j
;
4955 unsigned long present_pages
= zone
->present_pages
;
4957 zone
->lowmem_reserve
[j
] = 0;
4961 struct zone
*lower_zone
;
4965 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
4966 sysctl_lowmem_reserve_ratio
[idx
] = 1;
4968 lower_zone
= pgdat
->node_zones
+ idx
;
4969 lower_zone
->lowmem_reserve
[j
] = present_pages
/
4970 sysctl_lowmem_reserve_ratio
[idx
];
4971 present_pages
+= lower_zone
->present_pages
;
4976 /* update totalreserve_pages */
4977 calculate_totalreserve_pages();
4981 * setup_per_zone_wmarks - called when min_free_kbytes changes
4982 * or when memory is hot-{added|removed}
4984 * Ensures that the watermark[min,low,high] values for each zone are set
4985 * correctly with respect to min_free_kbytes.
4987 void setup_per_zone_wmarks(void)
4989 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
4990 unsigned long lowmem_pages
= 0;
4992 unsigned long flags
;
4994 /* Calculate total number of !ZONE_HIGHMEM pages */
4995 for_each_zone(zone
) {
4996 if (!is_highmem(zone
))
4997 lowmem_pages
+= zone
->present_pages
;
5000 for_each_zone(zone
) {
5003 spin_lock_irqsave(&zone
->lock
, flags
);
5004 tmp
= (u64
)pages_min
* zone
->present_pages
;
5005 do_div(tmp
, lowmem_pages
);
5006 if (is_highmem(zone
)) {
5008 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
5009 * need highmem pages, so cap pages_min to a small
5012 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
5013 * deltas controls asynch page reclaim, and so should
5014 * not be capped for highmem.
5018 min_pages
= zone
->present_pages
/ 1024;
5019 if (min_pages
< SWAP_CLUSTER_MAX
)
5020 min_pages
= SWAP_CLUSTER_MAX
;
5021 if (min_pages
> 128)
5023 zone
->watermark
[WMARK_MIN
] = min_pages
;
5026 * If it's a lowmem zone, reserve a number of pages
5027 * proportionate to the zone's size.
5029 zone
->watermark
[WMARK_MIN
] = tmp
;
5032 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + (tmp
>> 2);
5033 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + (tmp
>> 1);
5034 setup_zone_migrate_reserve(zone
);
5035 spin_unlock_irqrestore(&zone
->lock
, flags
);
5038 /* update totalreserve_pages */
5039 calculate_totalreserve_pages();
5043 * The inactive anon list should be small enough that the VM never has to
5044 * do too much work, but large enough that each inactive page has a chance
5045 * to be referenced again before it is swapped out.
5047 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
5048 * INACTIVE_ANON pages on this zone's LRU, maintained by the
5049 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
5050 * the anonymous pages are kept on the inactive list.
5053 * memory ratio inactive anon
5054 * -------------------------------------
5063 static void __meminit
calculate_zone_inactive_ratio(struct zone
*zone
)
5065 unsigned int gb
, ratio
;
5067 /* Zone size in gigabytes */
5068 gb
= zone
->present_pages
>> (30 - PAGE_SHIFT
);
5070 ratio
= int_sqrt(10 * gb
);
5074 zone
->inactive_ratio
= ratio
;
5077 static void __meminit
setup_per_zone_inactive_ratio(void)
5082 calculate_zone_inactive_ratio(zone
);
5086 * Initialise min_free_kbytes.
5088 * For small machines we want it small (128k min). For large machines
5089 * we want it large (64MB max). But it is not linear, because network
5090 * bandwidth does not increase linearly with machine size. We use
5092 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5093 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
5109 int __meminit
init_per_zone_wmark_min(void)
5111 unsigned long lowmem_kbytes
;
5113 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
5115 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
5116 if (min_free_kbytes
< 128)
5117 min_free_kbytes
= 128;
5118 if (min_free_kbytes
> 65536)
5119 min_free_kbytes
= 65536;
5120 setup_per_zone_wmarks();
5121 refresh_zone_stat_thresholds();
5122 setup_per_zone_lowmem_reserve();
5123 setup_per_zone_inactive_ratio();
5126 module_init(init_per_zone_wmark_min
)
5129 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5130 * that we can call two helper functions whenever min_free_kbytes
5133 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
5134 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5136 proc_dointvec(table
, write
, buffer
, length
, ppos
);
5138 setup_per_zone_wmarks();
5143 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
5144 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5149 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5154 zone
->min_unmapped_pages
= (zone
->present_pages
*
5155 sysctl_min_unmapped_ratio
) / 100;
5159 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
5160 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5165 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5170 zone
->min_slab_pages
= (zone
->present_pages
*
5171 sysctl_min_slab_ratio
) / 100;
5177 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5178 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5179 * whenever sysctl_lowmem_reserve_ratio changes.
5181 * The reserve ratio obviously has absolutely no relation with the
5182 * minimum watermarks. The lowmem reserve ratio can only make sense
5183 * if in function of the boot time zone sizes.
5185 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
5186 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5188 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5189 setup_per_zone_lowmem_reserve();
5194 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5195 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
5196 * can have before it gets flushed back to buddy allocator.
5199 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
5200 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5206 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5207 if (!write
|| (ret
< 0))
5209 for_each_populated_zone(zone
) {
5210 for_each_possible_cpu(cpu
) {
5212 high
= zone
->present_pages
/ percpu_pagelist_fraction
;
5213 setup_pagelist_highmark(
5214 per_cpu_ptr(zone
->pageset
, cpu
), high
);
5220 int hashdist
= HASHDIST_DEFAULT
;
5223 static int __init
set_hashdist(char *str
)
5227 hashdist
= simple_strtoul(str
, &str
, 0);
5230 __setup("hashdist=", set_hashdist
);
5234 * allocate a large system hash table from bootmem
5235 * - it is assumed that the hash table must contain an exact power-of-2
5236 * quantity of entries
5237 * - limit is the number of hash buckets, not the total allocation size
5239 void *__init
alloc_large_system_hash(const char *tablename
,
5240 unsigned long bucketsize
,
5241 unsigned long numentries
,
5244 unsigned int *_hash_shift
,
5245 unsigned int *_hash_mask
,
5246 unsigned long limit
)
5248 unsigned long long max
= limit
;
5249 unsigned long log2qty
, size
;
5252 /* allow the kernel cmdline to have a say */
5254 /* round applicable memory size up to nearest megabyte */
5255 numentries
= nr_kernel_pages
;
5256 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
5257 numentries
>>= 20 - PAGE_SHIFT
;
5258 numentries
<<= 20 - PAGE_SHIFT
;
5260 /* limit to 1 bucket per 2^scale bytes of low memory */
5261 if (scale
> PAGE_SHIFT
)
5262 numentries
>>= (scale
- PAGE_SHIFT
);
5264 numentries
<<= (PAGE_SHIFT
- scale
);
5266 /* Make sure we've got at least a 0-order allocation.. */
5267 if (unlikely(flags
& HASH_SMALL
)) {
5268 /* Makes no sense without HASH_EARLY */
5269 WARN_ON(!(flags
& HASH_EARLY
));
5270 if (!(numentries
>> *_hash_shift
)) {
5271 numentries
= 1UL << *_hash_shift
;
5272 BUG_ON(!numentries
);
5274 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
5275 numentries
= PAGE_SIZE
/ bucketsize
;
5277 numentries
= roundup_pow_of_two(numentries
);
5279 /* limit allocation size to 1/16 total memory by default */
5281 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
5282 do_div(max
, bucketsize
);
5284 max
= min(max
, 0x80000000ULL
);
5286 if (numentries
> max
)
5289 log2qty
= ilog2(numentries
);
5292 size
= bucketsize
<< log2qty
;
5293 if (flags
& HASH_EARLY
)
5294 table
= alloc_bootmem_nopanic(size
);
5296 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
5299 * If bucketsize is not a power-of-two, we may free
5300 * some pages at the end of hash table which
5301 * alloc_pages_exact() automatically does
5303 if (get_order(size
) < MAX_ORDER
) {
5304 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
5305 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
5308 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
5311 panic("Failed to allocate %s hash table\n", tablename
);
5313 printk(KERN_INFO
"%s hash table entries: %ld (order: %d, %lu bytes)\n",
5316 ilog2(size
) - PAGE_SHIFT
,
5320 *_hash_shift
= log2qty
;
5322 *_hash_mask
= (1 << log2qty
) - 1;
5327 /* Return a pointer to the bitmap storing bits affecting a block of pages */
5328 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
5331 #ifdef CONFIG_SPARSEMEM
5332 return __pfn_to_section(pfn
)->pageblock_flags
;
5334 return zone
->pageblock_flags
;
5335 #endif /* CONFIG_SPARSEMEM */
5338 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
5340 #ifdef CONFIG_SPARSEMEM
5341 pfn
&= (PAGES_PER_SECTION
-1);
5342 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5344 pfn
= pfn
- zone
->zone_start_pfn
;
5345 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5346 #endif /* CONFIG_SPARSEMEM */
5350 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5351 * @page: The page within the block of interest
5352 * @start_bitidx: The first bit of interest to retrieve
5353 * @end_bitidx: The last bit of interest
5354 * returns pageblock_bits flags
5356 unsigned long get_pageblock_flags_group(struct page
*page
,
5357 int start_bitidx
, int end_bitidx
)
5360 unsigned long *bitmap
;
5361 unsigned long pfn
, bitidx
;
5362 unsigned long flags
= 0;
5363 unsigned long value
= 1;
5365 zone
= page_zone(page
);
5366 pfn
= page_to_pfn(page
);
5367 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5368 bitidx
= pfn_to_bitidx(zone
, pfn
);
5370 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5371 if (test_bit(bitidx
+ start_bitidx
, bitmap
))
5378 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5379 * @page: The page within the block of interest
5380 * @start_bitidx: The first bit of interest
5381 * @end_bitidx: The last bit of interest
5382 * @flags: The flags to set
5384 void set_pageblock_flags_group(struct page
*page
, unsigned long flags
,
5385 int start_bitidx
, int end_bitidx
)
5388 unsigned long *bitmap
;
5389 unsigned long pfn
, bitidx
;
5390 unsigned long value
= 1;
5392 zone
= page_zone(page
);
5393 pfn
= page_to_pfn(page
);
5394 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5395 bitidx
= pfn_to_bitidx(zone
, pfn
);
5396 VM_BUG_ON(pfn
< zone
->zone_start_pfn
);
5397 VM_BUG_ON(pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
);
5399 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5401 __set_bit(bitidx
+ start_bitidx
, bitmap
);
5403 __clear_bit(bitidx
+ start_bitidx
, bitmap
);
5407 * This is designed as sub function...plz see page_isolation.c also.
5408 * set/clear page block's type to be ISOLATE.
5409 * page allocater never alloc memory from ISOLATE block.
5413 __count_immobile_pages(struct zone
*zone
, struct page
*page
, int count
)
5415 unsigned long pfn
, iter
, found
;
5417 * For avoiding noise data, lru_add_drain_all() should be called
5418 * If ZONE_MOVABLE, the zone never contains immobile pages
5420 if (zone_idx(zone
) == ZONE_MOVABLE
)
5423 if (get_pageblock_migratetype(page
) == MIGRATE_MOVABLE
)
5426 pfn
= page_to_pfn(page
);
5427 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
5428 unsigned long check
= pfn
+ iter
;
5430 if (!pfn_valid_within(check
))
5433 page
= pfn_to_page(check
);
5434 if (!page_count(page
)) {
5435 if (PageBuddy(page
))
5436 iter
+= (1 << page_order(page
)) - 1;
5442 * If there are RECLAIMABLE pages, we need to check it.
5443 * But now, memory offline itself doesn't call shrink_slab()
5444 * and it still to be fixed.
5447 * If the page is not RAM, page_count()should be 0.
5448 * we don't need more check. This is an _used_ not-movable page.
5450 * The problematic thing here is PG_reserved pages. PG_reserved
5451 * is set to both of a memory hole page and a _used_ kernel
5460 bool is_pageblock_removable_nolock(struct page
*page
)
5466 * We have to be careful here because we are iterating over memory
5467 * sections which are not zone aware so we might end up outside of
5468 * the zone but still within the section.
5469 * We have to take care about the node as well. If the node is offline
5470 * its NODE_DATA will be NULL - see page_zone.
5472 if (!node_online(page_to_nid(page
)))
5475 zone
= page_zone(page
);
5476 pfn
= page_to_pfn(page
);
5477 if (zone
->zone_start_pfn
> pfn
||
5478 zone
->zone_start_pfn
+ zone
->spanned_pages
<= pfn
)
5481 return __count_immobile_pages(zone
, page
, 0);
5484 int set_migratetype_isolate(struct page
*page
)
5487 unsigned long flags
, pfn
;
5488 struct memory_isolate_notify arg
;
5492 zone
= page_zone(page
);
5494 spin_lock_irqsave(&zone
->lock
, flags
);
5496 pfn
= page_to_pfn(page
);
5497 arg
.start_pfn
= pfn
;
5498 arg
.nr_pages
= pageblock_nr_pages
;
5499 arg
.pages_found
= 0;
5502 * It may be possible to isolate a pageblock even if the
5503 * migratetype is not MIGRATE_MOVABLE. The memory isolation
5504 * notifier chain is used by balloon drivers to return the
5505 * number of pages in a range that are held by the balloon
5506 * driver to shrink memory. If all the pages are accounted for
5507 * by balloons, are free, or on the LRU, isolation can continue.
5508 * Later, for example, when memory hotplug notifier runs, these
5509 * pages reported as "can be isolated" should be isolated(freed)
5510 * by the balloon driver through the memory notifier chain.
5512 notifier_ret
= memory_isolate_notify(MEM_ISOLATE_COUNT
, &arg
);
5513 notifier_ret
= notifier_to_errno(notifier_ret
);
5517 * FIXME: Now, memory hotplug doesn't call shrink_slab() by itself.
5518 * We just check MOVABLE pages.
5520 if (__count_immobile_pages(zone
, page
, arg
.pages_found
))
5524 * immobile means "not-on-lru" paes. If immobile is larger than
5525 * removable-by-driver pages reported by notifier, we'll fail.
5530 set_pageblock_migratetype(page
, MIGRATE_ISOLATE
);
5531 move_freepages_block(zone
, page
, MIGRATE_ISOLATE
);
5534 spin_unlock_irqrestore(&zone
->lock
, flags
);
5540 void unset_migratetype_isolate(struct page
*page
)
5543 unsigned long flags
;
5544 zone
= page_zone(page
);
5545 spin_lock_irqsave(&zone
->lock
, flags
);
5546 if (get_pageblock_migratetype(page
) != MIGRATE_ISOLATE
)
5548 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
5549 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
5551 spin_unlock_irqrestore(&zone
->lock
, flags
);
5556 static unsigned long pfn_max_align_down(unsigned long pfn
)
5558 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
5559 pageblock_nr_pages
) - 1);
5562 static unsigned long pfn_max_align_up(unsigned long pfn
)
5564 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
5565 pageblock_nr_pages
));
5568 static struct page
*
5569 __alloc_contig_migrate_alloc(struct page
*page
, unsigned long private,
5572 return alloc_page(GFP_HIGHUSER_MOVABLE
);
5575 /* [start, end) must belong to a single zone. */
5576 static int __alloc_contig_migrate_range(unsigned long start
, unsigned long end
)
5578 /* This function is based on compact_zone() from compaction.c. */
5580 unsigned long pfn
= start
;
5581 unsigned int tries
= 0;
5584 struct compact_control cc
= {
5585 .nr_migratepages
= 0,
5587 .zone
= page_zone(pfn_to_page(start
)),
5590 INIT_LIST_HEAD(&cc
.migratepages
);
5592 migrate_prep_local();
5594 while (pfn
< end
|| !list_empty(&cc
.migratepages
)) {
5595 if (fatal_signal_pending(current
)) {
5600 if (list_empty(&cc
.migratepages
)) {
5601 cc
.nr_migratepages
= 0;
5602 pfn
= isolate_migratepages_range(cc
.zone
, &cc
,
5609 } else if (++tries
== 5) {
5610 ret
= ret
< 0 ? ret
: -EBUSY
;
5614 ret
= migrate_pages(&cc
.migratepages
,
5615 __alloc_contig_migrate_alloc
,
5619 putback_lru_pages(&cc
.migratepages
);
5620 return ret
> 0 ? 0 : ret
;
5624 * alloc_contig_range() -- tries to allocate given range of pages
5625 * @start: start PFN to allocate
5626 * @end: one-past-the-last PFN to allocate
5628 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
5629 * aligned, however it's the caller's responsibility to guarantee that
5630 * we are the only thread that changes migrate type of pageblocks the
5633 * The PFN range must belong to a single zone.
5635 * Returns zero on success or negative error code. On success all
5636 * pages which PFN is in [start, end) are allocated for the caller and
5637 * need to be freed with free_contig_range().
5639 int alloc_contig_range(unsigned long start
, unsigned long end
)
5641 struct zone
*zone
= page_zone(pfn_to_page(start
));
5642 unsigned long outer_start
, outer_end
;
5646 * What we do here is we mark all pageblocks in range as
5647 * MIGRATE_ISOLATE. Because pageblock and max order pages may
5648 * have different sizes, and due to the way page allocator
5649 * work, we align the range to biggest of the two pages so
5650 * that page allocator won't try to merge buddies from
5651 * different pageblocks and change MIGRATE_ISOLATE to some
5652 * other migration type.
5654 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
5655 * migrate the pages from an unaligned range (ie. pages that
5656 * we are interested in). This will put all the pages in
5657 * range back to page allocator as MIGRATE_ISOLATE.
5659 * When this is done, we take the pages in range from page
5660 * allocator removing them from the buddy system. This way
5661 * page allocator will never consider using them.
5663 * This lets us mark the pageblocks back as
5664 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
5665 * aligned range but not in the unaligned, original range are
5666 * put back to page allocator so that buddy can use them.
5669 ret
= start_isolate_page_range(pfn_max_align_down(start
),
5670 pfn_max_align_up(end
));
5674 ret
= __alloc_contig_migrate_range(start
, end
);
5679 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
5680 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
5681 * more, all pages in [start, end) are free in page allocator.
5682 * What we are going to do is to allocate all pages from
5683 * [start, end) (that is remove them from page allocator).
5685 * The only problem is that pages at the beginning and at the
5686 * end of interesting range may be not aligned with pages that
5687 * page allocator holds, ie. they can be part of higher order
5688 * pages. Because of this, we reserve the bigger range and
5689 * once this is done free the pages we are not interested in.
5691 * We don't have to hold zone->lock here because the pages are
5692 * isolated thus they won't get removed from buddy.
5695 lru_add_drain_all();
5699 outer_start
= start
;
5700 while (!PageBuddy(pfn_to_page(outer_start
))) {
5701 if (++order
>= MAX_ORDER
) {
5705 outer_start
&= ~0UL << order
;
5708 /* Make sure the range is really isolated. */
5709 if (test_pages_isolated(outer_start
, end
)) {
5710 pr_warn("alloc_contig_range test_pages_isolated(%lx, %lx) failed\n",
5716 outer_end
= isolate_freepages_range(outer_start
, end
);
5722 /* Free head and tail (if any) */
5723 if (start
!= outer_start
)
5724 free_contig_range(outer_start
, start
- outer_start
);
5725 if (end
!= outer_end
)
5726 free_contig_range(end
, outer_end
- end
);
5729 undo_isolate_page_range(pfn_max_align_down(start
),
5730 pfn_max_align_up(end
));
5734 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
5736 for (; nr_pages
--; ++pfn
)
5737 __free_page(pfn_to_page(pfn
));
5741 #ifdef CONFIG_MEMORY_HOTREMOVE
5743 * All pages in the range must be isolated before calling this.
5746 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
5752 unsigned long flags
;
5753 /* find the first valid pfn */
5754 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
5759 zone
= page_zone(pfn_to_page(pfn
));
5760 spin_lock_irqsave(&zone
->lock
, flags
);
5762 while (pfn
< end_pfn
) {
5763 if (!pfn_valid(pfn
)) {
5767 page
= pfn_to_page(pfn
);
5768 BUG_ON(page_count(page
));
5769 BUG_ON(!PageBuddy(page
));
5770 order
= page_order(page
);
5771 #ifdef CONFIG_DEBUG_VM
5772 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
5773 pfn
, 1 << order
, end_pfn
);
5775 list_del(&page
->lru
);
5776 rmv_page_order(page
);
5777 zone
->free_area
[order
].nr_free
--;
5778 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
5780 for (i
= 0; i
< (1 << order
); i
++)
5781 SetPageReserved((page
+i
));
5782 pfn
+= (1 << order
);
5784 spin_unlock_irqrestore(&zone
->lock
, flags
);
5788 #ifdef CONFIG_MEMORY_FAILURE
5789 bool is_free_buddy_page(struct page
*page
)
5791 struct zone
*zone
= page_zone(page
);
5792 unsigned long pfn
= page_to_pfn(page
);
5793 unsigned long flags
;
5796 spin_lock_irqsave(&zone
->lock
, flags
);
5797 for (order
= 0; order
< MAX_ORDER
; order
++) {
5798 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
5800 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
5803 spin_unlock_irqrestore(&zone
->lock
, flags
);
5805 return order
< MAX_ORDER
;
5809 static struct trace_print_flags pageflag_names
[] = {
5810 {1UL << PG_locked
, "locked" },
5811 {1UL << PG_error
, "error" },
5812 {1UL << PG_referenced
, "referenced" },
5813 {1UL << PG_uptodate
, "uptodate" },
5814 {1UL << PG_dirty
, "dirty" },
5815 {1UL << PG_lru
, "lru" },
5816 {1UL << PG_active
, "active" },
5817 {1UL << PG_slab
, "slab" },
5818 {1UL << PG_owner_priv_1
, "owner_priv_1" },
5819 {1UL << PG_arch_1
, "arch_1" },
5820 {1UL << PG_reserved
, "reserved" },
5821 {1UL << PG_private
, "private" },
5822 {1UL << PG_private_2
, "private_2" },
5823 {1UL << PG_writeback
, "writeback" },
5824 #ifdef CONFIG_PAGEFLAGS_EXTENDED
5825 {1UL << PG_head
, "head" },
5826 {1UL << PG_tail
, "tail" },
5828 {1UL << PG_compound
, "compound" },
5830 {1UL << PG_swapcache
, "swapcache" },
5831 {1UL << PG_mappedtodisk
, "mappedtodisk" },
5832 {1UL << PG_reclaim
, "reclaim" },
5833 {1UL << PG_swapbacked
, "swapbacked" },
5834 {1UL << PG_unevictable
, "unevictable" },
5836 {1UL << PG_mlocked
, "mlocked" },
5838 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
5839 {1UL << PG_uncached
, "uncached" },
5841 #ifdef CONFIG_MEMORY_FAILURE
5842 {1UL << PG_hwpoison
, "hwpoison" },
5847 static void dump_page_flags(unsigned long flags
)
5849 const char *delim
= "";
5853 printk(KERN_ALERT
"page flags: %#lx(", flags
);
5855 /* remove zone id */
5856 flags
&= (1UL << NR_PAGEFLAGS
) - 1;
5858 for (i
= 0; pageflag_names
[i
].name
&& flags
; i
++) {
5860 mask
= pageflag_names
[i
].mask
;
5861 if ((flags
& mask
) != mask
)
5865 printk("%s%s", delim
, pageflag_names
[i
].name
);
5869 /* check for left over flags */
5871 printk("%s%#lx", delim
, flags
);
5876 void dump_page(struct page
*page
)
5879 "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
5880 page
, atomic_read(&page
->_count
), page_mapcount(page
),
5881 page
->mapping
, page
->index
);
5882 dump_page_flags(page
->flags
);
5883 mem_cgroup_print_bad_page(page
);