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/page-debug-flags.h>
62 #include <asm/tlbflush.h>
63 #include <asm/div64.h>
66 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
67 DEFINE_PER_CPU(int, numa_node
);
68 EXPORT_PER_CPU_SYMBOL(numa_node
);
71 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
73 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
74 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
75 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
76 * defined in <linux/topology.h>.
78 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
79 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
83 * Array of node states.
85 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
86 [N_POSSIBLE
] = NODE_MASK_ALL
,
87 [N_ONLINE
] = { { [0] = 1UL } },
89 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
91 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
93 [N_CPU
] = { { [0] = 1UL } },
96 EXPORT_SYMBOL(node_states
);
98 unsigned long totalram_pages __read_mostly
;
99 unsigned long totalreserve_pages __read_mostly
;
101 * When calculating the number of globally allowed dirty pages, there
102 * is a certain number of per-zone reserves that should not be
103 * considered dirtyable memory. This is the sum of those reserves
104 * over all existing zones that contribute dirtyable memory.
106 unsigned long dirty_balance_reserve __read_mostly
;
108 int percpu_pagelist_fraction
;
109 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
111 #ifdef CONFIG_PM_SLEEP
113 * The following functions are used by the suspend/hibernate code to temporarily
114 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
115 * while devices are suspended. To avoid races with the suspend/hibernate code,
116 * they should always be called with pm_mutex held (gfp_allowed_mask also should
117 * only be modified with pm_mutex held, unless the suspend/hibernate code is
118 * guaranteed not to run in parallel with that modification).
121 static gfp_t saved_gfp_mask
;
123 void pm_restore_gfp_mask(void)
125 WARN_ON(!mutex_is_locked(&pm_mutex
));
126 if (saved_gfp_mask
) {
127 gfp_allowed_mask
= saved_gfp_mask
;
132 void pm_restrict_gfp_mask(void)
134 WARN_ON(!mutex_is_locked(&pm_mutex
));
135 WARN_ON(saved_gfp_mask
);
136 saved_gfp_mask
= gfp_allowed_mask
;
137 gfp_allowed_mask
&= ~GFP_IOFS
;
140 bool pm_suspended_storage(void)
142 if ((gfp_allowed_mask
& GFP_IOFS
) == GFP_IOFS
)
146 #endif /* CONFIG_PM_SLEEP */
148 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
149 int pageblock_order __read_mostly
;
152 static void __free_pages_ok(struct page
*page
, unsigned int order
);
155 * results with 256, 32 in the lowmem_reserve sysctl:
156 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
157 * 1G machine -> (16M dma, 784M normal, 224M high)
158 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
159 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
160 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
162 * TBD: should special case ZONE_DMA32 machines here - in those we normally
163 * don't need any ZONE_NORMAL reservation
165 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
166 #ifdef CONFIG_ZONE_DMA
169 #ifdef CONFIG_ZONE_DMA32
172 #ifdef CONFIG_HIGHMEM
178 EXPORT_SYMBOL(totalram_pages
);
180 static char * const zone_names
[MAX_NR_ZONES
] = {
181 #ifdef CONFIG_ZONE_DMA
184 #ifdef CONFIG_ZONE_DMA32
188 #ifdef CONFIG_HIGHMEM
194 int min_free_kbytes
= 1024;
196 static unsigned long __meminitdata nr_kernel_pages
;
197 static unsigned long __meminitdata nr_all_pages
;
198 static unsigned long __meminitdata dma_reserve
;
200 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
201 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
202 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
203 static unsigned long __initdata required_kernelcore
;
204 static unsigned long __initdata required_movablecore
;
205 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
207 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
209 EXPORT_SYMBOL(movable_zone
);
210 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
213 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
214 int nr_online_nodes __read_mostly
= 1;
215 EXPORT_SYMBOL(nr_node_ids
);
216 EXPORT_SYMBOL(nr_online_nodes
);
219 int page_group_by_mobility_disabled __read_mostly
;
221 static void set_pageblock_migratetype(struct page
*page
, int migratetype
)
224 if (unlikely(page_group_by_mobility_disabled
))
225 migratetype
= MIGRATE_UNMOVABLE
;
227 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
228 PB_migrate
, PB_migrate_end
);
231 bool oom_killer_disabled __read_mostly
;
233 #ifdef CONFIG_DEBUG_VM
234 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
238 unsigned long pfn
= page_to_pfn(page
);
241 seq
= zone_span_seqbegin(zone
);
242 if (pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
244 else if (pfn
< zone
->zone_start_pfn
)
246 } while (zone_span_seqretry(zone
, seq
));
251 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
253 if (!pfn_valid_within(page_to_pfn(page
)))
255 if (zone
!= page_zone(page
))
261 * Temporary debugging check for pages not lying within a given zone.
263 static int bad_range(struct zone
*zone
, struct page
*page
)
265 if (page_outside_zone_boundaries(zone
, page
))
267 if (!page_is_consistent(zone
, page
))
273 static inline int bad_range(struct zone
*zone
, struct page
*page
)
279 static void bad_page(struct page
*page
)
281 static unsigned long resume
;
282 static unsigned long nr_shown
;
283 static unsigned long nr_unshown
;
285 /* Don't complain about poisoned pages */
286 if (PageHWPoison(page
)) {
287 reset_page_mapcount(page
); /* remove PageBuddy */
292 * Allow a burst of 60 reports, then keep quiet for that minute;
293 * or allow a steady drip of one report per second.
295 if (nr_shown
== 60) {
296 if (time_before(jiffies
, resume
)) {
302 "BUG: Bad page state: %lu messages suppressed\n",
309 resume
= jiffies
+ 60 * HZ
;
311 printk(KERN_ALERT
"BUG: Bad page state in process %s pfn:%05lx\n",
312 current
->comm
, page_to_pfn(page
));
318 /* Leave bad fields for debug, except PageBuddy could make trouble */
319 reset_page_mapcount(page
); /* remove PageBuddy */
320 add_taint(TAINT_BAD_PAGE
);
324 * Higher-order pages are called "compound pages". They are structured thusly:
326 * The first PAGE_SIZE page is called the "head page".
328 * The remaining PAGE_SIZE pages are called "tail pages".
330 * All pages have PG_compound set. All tail pages have their ->first_page
331 * pointing at the head page.
333 * The first tail page's ->lru.next holds the address of the compound page's
334 * put_page() function. Its ->lru.prev holds the order of allocation.
335 * This usage means that zero-order pages may not be compound.
338 static void free_compound_page(struct page
*page
)
340 __free_pages_ok(page
, compound_order(page
));
343 void prep_compound_page(struct page
*page
, unsigned long order
)
346 int nr_pages
= 1 << order
;
348 set_compound_page_dtor(page
, free_compound_page
);
349 set_compound_order(page
, order
);
351 for (i
= 1; i
< nr_pages
; i
++) {
352 struct page
*p
= page
+ i
;
354 set_page_count(p
, 0);
355 p
->first_page
= page
;
359 /* update __split_huge_page_refcount if you change this function */
360 static int destroy_compound_page(struct page
*page
, unsigned long order
)
363 int nr_pages
= 1 << order
;
366 if (unlikely(compound_order(page
) != order
) ||
367 unlikely(!PageHead(page
))) {
372 __ClearPageHead(page
);
374 for (i
= 1; i
< nr_pages
; i
++) {
375 struct page
*p
= page
+ i
;
377 if (unlikely(!PageTail(p
) || (p
->first_page
!= page
))) {
387 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
392 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
393 * and __GFP_HIGHMEM from hard or soft interrupt context.
395 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
396 for (i
= 0; i
< (1 << order
); i
++)
397 clear_highpage(page
+ i
);
400 #ifdef CONFIG_DEBUG_PAGEALLOC
401 unsigned int _debug_guardpage_minorder
;
403 static int __init
debug_guardpage_minorder_setup(char *buf
)
407 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
408 printk(KERN_ERR
"Bad debug_guardpage_minorder value\n");
411 _debug_guardpage_minorder
= res
;
412 printk(KERN_INFO
"Setting debug_guardpage_minorder to %lu\n", res
);
415 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
417 static inline void set_page_guard_flag(struct page
*page
)
419 __set_bit(PAGE_DEBUG_FLAG_GUARD
, &page
->debug_flags
);
422 static inline void clear_page_guard_flag(struct page
*page
)
424 __clear_bit(PAGE_DEBUG_FLAG_GUARD
, &page
->debug_flags
);
427 static inline void set_page_guard_flag(struct page
*page
) { }
428 static inline void clear_page_guard_flag(struct page
*page
) { }
431 static inline void set_page_order(struct page
*page
, int order
)
433 set_page_private(page
, order
);
434 __SetPageBuddy(page
);
437 static inline void rmv_page_order(struct page
*page
)
439 __ClearPageBuddy(page
);
440 set_page_private(page
, 0);
444 * Locate the struct page for both the matching buddy in our
445 * pair (buddy1) and the combined O(n+1) page they form (page).
447 * 1) Any buddy B1 will have an order O twin B2 which satisfies
448 * the following equation:
450 * For example, if the starting buddy (buddy2) is #8 its order
452 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
454 * 2) Any buddy B will have an order O+1 parent P which
455 * satisfies the following equation:
458 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
460 static inline unsigned long
461 __find_buddy_index(unsigned long page_idx
, unsigned int order
)
463 return page_idx
^ (1 << order
);
467 * This function checks whether a page is free && is the buddy
468 * we can do coalesce a page and its buddy if
469 * (a) the buddy is not in a hole &&
470 * (b) the buddy is in the buddy system &&
471 * (c) a page and its buddy have the same order &&
472 * (d) a page and its buddy are in the same zone.
474 * For recording whether a page is in the buddy system, we set ->_mapcount -2.
475 * Setting, clearing, and testing _mapcount -2 is serialized by zone->lock.
477 * For recording page's order, we use page_private(page).
479 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
482 if (!pfn_valid_within(page_to_pfn(buddy
)))
485 if (page_zone_id(page
) != page_zone_id(buddy
))
488 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
489 VM_BUG_ON(page_count(buddy
) != 0);
493 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
494 VM_BUG_ON(page_count(buddy
) != 0);
501 * Freeing function for a buddy system allocator.
503 * The concept of a buddy system is to maintain direct-mapped table
504 * (containing bit values) for memory blocks of various "orders".
505 * The bottom level table contains the map for the smallest allocatable
506 * units of memory (here, pages), and each level above it describes
507 * pairs of units from the levels below, hence, "buddies".
508 * At a high level, all that happens here is marking the table entry
509 * at the bottom level available, and propagating the changes upward
510 * as necessary, plus some accounting needed to play nicely with other
511 * parts of the VM system.
512 * At each level, we keep a list of pages, which are heads of continuous
513 * free pages of length of (1 << order) and marked with _mapcount -2. Page's
514 * order is recorded in page_private(page) field.
515 * So when we are allocating or freeing one, we can derive the state of the
516 * other. That is, if we allocate a small block, and both were
517 * free, the remainder of the region must be split into blocks.
518 * If a block is freed, and its buddy is also free, then this
519 * triggers coalescing into a block of larger size.
524 static inline void __free_one_page(struct page
*page
,
525 struct zone
*zone
, unsigned int order
,
528 unsigned long page_idx
;
529 unsigned long combined_idx
;
530 unsigned long uninitialized_var(buddy_idx
);
533 if (unlikely(PageCompound(page
)))
534 if (unlikely(destroy_compound_page(page
, order
)))
537 VM_BUG_ON(migratetype
== -1);
539 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
541 VM_BUG_ON(page_idx
& ((1 << order
) - 1));
542 VM_BUG_ON(bad_range(zone
, page
));
544 while (order
< MAX_ORDER
-1) {
545 buddy_idx
= __find_buddy_index(page_idx
, order
);
546 buddy
= page
+ (buddy_idx
- page_idx
);
547 if (!page_is_buddy(page
, buddy
, order
))
550 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
551 * merge with it and move up one order.
553 if (page_is_guard(buddy
)) {
554 clear_page_guard_flag(buddy
);
555 set_page_private(page
, 0);
556 __mod_zone_page_state(zone
, NR_FREE_PAGES
, 1 << order
);
558 list_del(&buddy
->lru
);
559 zone
->free_area
[order
].nr_free
--;
560 rmv_page_order(buddy
);
562 combined_idx
= buddy_idx
& page_idx
;
563 page
= page
+ (combined_idx
- page_idx
);
564 page_idx
= combined_idx
;
567 set_page_order(page
, order
);
570 * If this is not the largest possible page, check if the buddy
571 * of the next-highest order is free. If it is, it's possible
572 * that pages are being freed that will coalesce soon. In case,
573 * that is happening, add the free page to the tail of the list
574 * so it's less likely to be used soon and more likely to be merged
575 * as a higher order page
577 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
578 struct page
*higher_page
, *higher_buddy
;
579 combined_idx
= buddy_idx
& page_idx
;
580 higher_page
= page
+ (combined_idx
- page_idx
);
581 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
582 higher_buddy
= page
+ (buddy_idx
- combined_idx
);
583 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
584 list_add_tail(&page
->lru
,
585 &zone
->free_area
[order
].free_list
[migratetype
]);
590 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
592 zone
->free_area
[order
].nr_free
++;
596 * free_page_mlock() -- clean up attempts to free and mlocked() page.
597 * Page should not be on lru, so no need to fix that up.
598 * free_pages_check() will verify...
600 static inline void free_page_mlock(struct page
*page
)
602 __dec_zone_page_state(page
, NR_MLOCK
);
603 __count_vm_event(UNEVICTABLE_MLOCKFREED
);
606 static inline int free_pages_check(struct page
*page
)
608 if (unlikely(page_mapcount(page
) |
609 (page
->mapping
!= NULL
) |
610 (atomic_read(&page
->_count
) != 0) |
611 (page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
) |
612 (mem_cgroup_bad_page_check(page
)))) {
616 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
617 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
622 * Frees a number of pages from the PCP lists
623 * Assumes all pages on list are in same zone, and of same order.
624 * count is the number of pages to free.
626 * If the zone was previously in an "all pages pinned" state then look to
627 * see if this freeing clears that state.
629 * And clear the zone's pages_scanned counter, to hold off the "all pages are
630 * pinned" detection logic.
632 static void free_pcppages_bulk(struct zone
*zone
, int count
,
633 struct per_cpu_pages
*pcp
)
639 spin_lock(&zone
->lock
);
640 zone
->all_unreclaimable
= 0;
641 zone
->pages_scanned
= 0;
645 struct list_head
*list
;
648 * Remove pages from lists in a round-robin fashion. A
649 * batch_free count is maintained that is incremented when an
650 * empty list is encountered. This is so more pages are freed
651 * off fuller lists instead of spinning excessively around empty
656 if (++migratetype
== MIGRATE_PCPTYPES
)
658 list
= &pcp
->lists
[migratetype
];
659 } while (list_empty(list
));
661 /* This is the only non-empty list. Free them all. */
662 if (batch_free
== MIGRATE_PCPTYPES
)
663 batch_free
= to_free
;
666 page
= list_entry(list
->prev
, struct page
, lru
);
667 /* must delete as __free_one_page list manipulates */
668 list_del(&page
->lru
);
669 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
670 __free_one_page(page
, zone
, 0, page_private(page
));
671 trace_mm_page_pcpu_drain(page
, 0, page_private(page
));
672 } while (--to_free
&& --batch_free
&& !list_empty(list
));
674 __mod_zone_page_state(zone
, NR_FREE_PAGES
, count
);
675 spin_unlock(&zone
->lock
);
678 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
,
681 spin_lock(&zone
->lock
);
682 zone
->all_unreclaimable
= 0;
683 zone
->pages_scanned
= 0;
685 __free_one_page(page
, zone
, order
, migratetype
);
686 __mod_zone_page_state(zone
, NR_FREE_PAGES
, 1 << order
);
687 spin_unlock(&zone
->lock
);
690 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
695 trace_mm_page_free(page
, order
);
696 kmemcheck_free_shadow(page
, order
);
699 page
->mapping
= NULL
;
700 for (i
= 0; i
< (1 << order
); i
++)
701 bad
+= free_pages_check(page
+ i
);
705 if (!PageHighMem(page
)) {
706 debug_check_no_locks_freed(page_address(page
),PAGE_SIZE
<<order
);
707 debug_check_no_obj_freed(page_address(page
),
710 arch_free_page(page
, order
);
711 kernel_map_pages(page
, 1 << order
, 0);
716 static void __free_pages_ok(struct page
*page
, unsigned int order
)
719 int wasMlocked
= __TestClearPageMlocked(page
);
721 if (!free_pages_prepare(page
, order
))
724 local_irq_save(flags
);
725 if (unlikely(wasMlocked
))
726 free_page_mlock(page
);
727 __count_vm_events(PGFREE
, 1 << order
);
728 free_one_page(page_zone(page
), page
, order
,
729 get_pageblock_migratetype(page
));
730 local_irq_restore(flags
);
733 void __meminit
__free_pages_bootmem(struct page
*page
, unsigned int order
)
735 unsigned int nr_pages
= 1 << order
;
739 for (loop
= 0; loop
< nr_pages
; loop
++) {
740 struct page
*p
= &page
[loop
];
742 if (loop
+ 1 < nr_pages
)
744 __ClearPageReserved(p
);
745 set_page_count(p
, 0);
748 set_page_refcounted(page
);
749 __free_pages(page
, order
);
754 * The order of subdivision here is critical for the IO subsystem.
755 * Please do not alter this order without good reasons and regression
756 * testing. Specifically, as large blocks of memory are subdivided,
757 * the order in which smaller blocks are delivered depends on the order
758 * they're subdivided in this function. This is the primary factor
759 * influencing the order in which pages are delivered to the IO
760 * subsystem according to empirical testing, and this is also justified
761 * by considering the behavior of a buddy system containing a single
762 * large block of memory acted on by a series of small allocations.
763 * This behavior is a critical factor in sglist merging's success.
767 static inline void expand(struct zone
*zone
, struct page
*page
,
768 int low
, int high
, struct free_area
*area
,
771 unsigned long size
= 1 << high
;
777 VM_BUG_ON(bad_range(zone
, &page
[size
]));
779 #ifdef CONFIG_DEBUG_PAGEALLOC
780 if (high
< debug_guardpage_minorder()) {
782 * Mark as guard pages (or page), that will allow to
783 * merge back to allocator when buddy will be freed.
784 * Corresponding page table entries will not be touched,
785 * pages will stay not present in virtual address space
787 INIT_LIST_HEAD(&page
[size
].lru
);
788 set_page_guard_flag(&page
[size
]);
789 set_page_private(&page
[size
], high
);
790 /* Guard pages are not available for any usage */
791 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(1 << high
));
795 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
797 set_page_order(&page
[size
], high
);
802 * This page is about to be returned from the page allocator
804 static inline int check_new_page(struct page
*page
)
806 if (unlikely(page_mapcount(page
) |
807 (page
->mapping
!= NULL
) |
808 (atomic_read(&page
->_count
) != 0) |
809 (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
) |
810 (mem_cgroup_bad_page_check(page
)))) {
817 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
821 for (i
= 0; i
< (1 << order
); i
++) {
822 struct page
*p
= page
+ i
;
823 if (unlikely(check_new_page(p
)))
827 set_page_private(page
, 0);
828 set_page_refcounted(page
);
830 arch_alloc_page(page
, order
);
831 kernel_map_pages(page
, 1 << order
, 1);
833 if (gfp_flags
& __GFP_ZERO
)
834 prep_zero_page(page
, order
, gfp_flags
);
836 if (order
&& (gfp_flags
& __GFP_COMP
))
837 prep_compound_page(page
, order
);
843 * Go through the free lists for the given migratetype and remove
844 * the smallest available page from the freelists
847 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
850 unsigned int current_order
;
851 struct free_area
* area
;
854 /* Find a page of the appropriate size in the preferred list */
855 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
856 area
= &(zone
->free_area
[current_order
]);
857 if (list_empty(&area
->free_list
[migratetype
]))
860 page
= list_entry(area
->free_list
[migratetype
].next
,
862 list_del(&page
->lru
);
863 rmv_page_order(page
);
865 expand(zone
, page
, order
, current_order
, area
, migratetype
);
874 * This array describes the order lists are fallen back to when
875 * the free lists for the desirable migrate type are depleted
877 static int fallbacks
[MIGRATE_TYPES
][MIGRATE_TYPES
-1] = {
878 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
879 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
880 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
881 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
, MIGRATE_RESERVE
, MIGRATE_RESERVE
}, /* Never used */
885 * Move the free pages in a range to the free lists of the requested type.
886 * Note that start_page and end_pages are not aligned on a pageblock
887 * boundary. If alignment is required, use move_freepages_block()
889 static int move_freepages(struct zone
*zone
,
890 struct page
*start_page
, struct page
*end_page
,
897 #ifndef CONFIG_HOLES_IN_ZONE
899 * page_zone is not safe to call in this context when
900 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
901 * anyway as we check zone boundaries in move_freepages_block().
902 * Remove at a later date when no bug reports exist related to
903 * grouping pages by mobility
905 BUG_ON(page_zone(start_page
) != page_zone(end_page
));
908 for (page
= start_page
; page
<= end_page
;) {
909 /* Make sure we are not inadvertently changing nodes */
910 VM_BUG_ON(page_to_nid(page
) != zone_to_nid(zone
));
912 if (!pfn_valid_within(page_to_pfn(page
))) {
917 if (!PageBuddy(page
)) {
922 order
= page_order(page
);
923 list_move(&page
->lru
,
924 &zone
->free_area
[order
].free_list
[migratetype
]);
926 pages_moved
+= 1 << order
;
932 static int move_freepages_block(struct zone
*zone
, struct page
*page
,
935 unsigned long start_pfn
, end_pfn
;
936 struct page
*start_page
, *end_page
;
938 start_pfn
= page_to_pfn(page
);
939 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
940 start_page
= pfn_to_page(start_pfn
);
941 end_page
= start_page
+ pageblock_nr_pages
- 1;
942 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
944 /* Do not cross zone boundaries */
945 if (start_pfn
< zone
->zone_start_pfn
)
947 if (end_pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
950 return move_freepages(zone
, start_page
, end_page
, migratetype
);
953 static void change_pageblock_range(struct page
*pageblock_page
,
954 int start_order
, int migratetype
)
956 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
958 while (nr_pageblocks
--) {
959 set_pageblock_migratetype(pageblock_page
, migratetype
);
960 pageblock_page
+= pageblock_nr_pages
;
964 /* Remove an element from the buddy allocator from the fallback list */
965 static inline struct page
*
966 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
)
968 struct free_area
* area
;
973 /* Find the largest possible block of pages in the other list */
974 for (current_order
= MAX_ORDER
-1; current_order
>= order
;
976 for (i
= 0; i
< MIGRATE_TYPES
- 1; i
++) {
977 migratetype
= fallbacks
[start_migratetype
][i
];
979 /* MIGRATE_RESERVE handled later if necessary */
980 if (migratetype
== MIGRATE_RESERVE
)
983 area
= &(zone
->free_area
[current_order
]);
984 if (list_empty(&area
->free_list
[migratetype
]))
987 page
= list_entry(area
->free_list
[migratetype
].next
,
992 * If breaking a large block of pages, move all free
993 * pages to the preferred allocation list. If falling
994 * back for a reclaimable kernel allocation, be more
995 * aggressive about taking ownership of free pages
997 if (unlikely(current_order
>= (pageblock_order
>> 1)) ||
998 start_migratetype
== MIGRATE_RECLAIMABLE
||
999 page_group_by_mobility_disabled
) {
1000 unsigned long pages
;
1001 pages
= move_freepages_block(zone
, page
,
1004 /* Claim the whole block if over half of it is free */
1005 if (pages
>= (1 << (pageblock_order
-1)) ||
1006 page_group_by_mobility_disabled
)
1007 set_pageblock_migratetype(page
,
1010 migratetype
= start_migratetype
;
1013 /* Remove the page from the freelists */
1014 list_del(&page
->lru
);
1015 rmv_page_order(page
);
1017 /* Take ownership for orders >= pageblock_order */
1018 if (current_order
>= pageblock_order
)
1019 change_pageblock_range(page
, current_order
,
1022 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1024 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
1025 start_migratetype
, migratetype
);
1035 * Do the hard work of removing an element from the buddy allocator.
1036 * Call me with the zone->lock already held.
1038 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
1044 page
= __rmqueue_smallest(zone
, order
, migratetype
);
1046 if (unlikely(!page
) && migratetype
!= MIGRATE_RESERVE
) {
1047 page
= __rmqueue_fallback(zone
, order
, migratetype
);
1050 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1051 * is used because __rmqueue_smallest is an inline function
1052 * and we want just one call site
1055 migratetype
= MIGRATE_RESERVE
;
1060 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1065 * Obtain a specified number of elements from the buddy allocator, all under
1066 * a single hold of the lock, for efficiency. Add them to the supplied list.
1067 * Returns the number of new pages which were placed at *list.
1069 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1070 unsigned long count
, struct list_head
*list
,
1071 int migratetype
, int cold
)
1075 spin_lock(&zone
->lock
);
1076 for (i
= 0; i
< count
; ++i
) {
1077 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
1078 if (unlikely(page
== NULL
))
1082 * Split buddy pages returned by expand() are received here
1083 * in physical page order. The page is added to the callers and
1084 * list and the list head then moves forward. From the callers
1085 * perspective, the linked list is ordered by page number in
1086 * some conditions. This is useful for IO devices that can
1087 * merge IO requests if the physical pages are ordered
1090 if (likely(cold
== 0))
1091 list_add(&page
->lru
, list
);
1093 list_add_tail(&page
->lru
, list
);
1094 set_page_private(page
, migratetype
);
1097 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
1098 spin_unlock(&zone
->lock
);
1104 * Called from the vmstat counter updater to drain pagesets of this
1105 * currently executing processor on remote nodes after they have
1108 * Note that this function must be called with the thread pinned to
1109 * a single processor.
1111 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
1113 unsigned long flags
;
1116 local_irq_save(flags
);
1117 if (pcp
->count
>= pcp
->batch
)
1118 to_drain
= pcp
->batch
;
1120 to_drain
= pcp
->count
;
1121 free_pcppages_bulk(zone
, to_drain
, pcp
);
1122 pcp
->count
-= to_drain
;
1123 local_irq_restore(flags
);
1128 * Drain pages of the indicated processor.
1130 * The processor must either be the current processor and the
1131 * thread pinned to the current processor or a processor that
1134 static void drain_pages(unsigned int cpu
)
1136 unsigned long flags
;
1139 for_each_populated_zone(zone
) {
1140 struct per_cpu_pageset
*pset
;
1141 struct per_cpu_pages
*pcp
;
1143 local_irq_save(flags
);
1144 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
1148 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1151 local_irq_restore(flags
);
1156 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1158 void drain_local_pages(void *arg
)
1160 drain_pages(smp_processor_id());
1164 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
1166 void drain_all_pages(void)
1168 on_each_cpu(drain_local_pages
, NULL
, 1);
1171 #ifdef CONFIG_HIBERNATION
1173 void mark_free_pages(struct zone
*zone
)
1175 unsigned long pfn
, max_zone_pfn
;
1176 unsigned long flags
;
1178 struct list_head
*curr
;
1180 if (!zone
->spanned_pages
)
1183 spin_lock_irqsave(&zone
->lock
, flags
);
1185 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
1186 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1187 if (pfn_valid(pfn
)) {
1188 struct page
*page
= pfn_to_page(pfn
);
1190 if (!swsusp_page_is_forbidden(page
))
1191 swsusp_unset_page_free(page
);
1194 for_each_migratetype_order(order
, t
) {
1195 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
1198 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
1199 for (i
= 0; i
< (1UL << order
); i
++)
1200 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
1203 spin_unlock_irqrestore(&zone
->lock
, flags
);
1205 #endif /* CONFIG_PM */
1208 * Free a 0-order page
1209 * cold == 1 ? free a cold page : free a hot page
1211 void free_hot_cold_page(struct page
*page
, int cold
)
1213 struct zone
*zone
= page_zone(page
);
1214 struct per_cpu_pages
*pcp
;
1215 unsigned long flags
;
1217 int wasMlocked
= __TestClearPageMlocked(page
);
1219 if (!free_pages_prepare(page
, 0))
1222 migratetype
= get_pageblock_migratetype(page
);
1223 set_page_private(page
, migratetype
);
1224 local_irq_save(flags
);
1225 if (unlikely(wasMlocked
))
1226 free_page_mlock(page
);
1227 __count_vm_event(PGFREE
);
1230 * We only track unmovable, reclaimable and movable on pcp lists.
1231 * Free ISOLATE pages back to the allocator because they are being
1232 * offlined but treat RESERVE as movable pages so we can get those
1233 * areas back if necessary. Otherwise, we may have to free
1234 * excessively into the page allocator
1236 if (migratetype
>= MIGRATE_PCPTYPES
) {
1237 if (unlikely(migratetype
== MIGRATE_ISOLATE
)) {
1238 free_one_page(zone
, page
, 0, migratetype
);
1241 migratetype
= MIGRATE_MOVABLE
;
1244 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1246 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
1248 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
1250 if (pcp
->count
>= pcp
->high
) {
1251 free_pcppages_bulk(zone
, pcp
->batch
, pcp
);
1252 pcp
->count
-= pcp
->batch
;
1256 local_irq_restore(flags
);
1260 * Free a list of 0-order pages
1262 void free_hot_cold_page_list(struct list_head
*list
, int cold
)
1264 struct page
*page
, *next
;
1266 list_for_each_entry_safe(page
, next
, list
, lru
) {
1267 trace_mm_page_free_batched(page
, cold
);
1268 free_hot_cold_page(page
, cold
);
1273 * split_page takes a non-compound higher-order page, and splits it into
1274 * n (1<<order) sub-pages: page[0..n]
1275 * Each sub-page must be freed individually.
1277 * Note: this is probably too low level an operation for use in drivers.
1278 * Please consult with lkml before using this in your driver.
1280 void split_page(struct page
*page
, unsigned int order
)
1284 VM_BUG_ON(PageCompound(page
));
1285 VM_BUG_ON(!page_count(page
));
1287 #ifdef CONFIG_KMEMCHECK
1289 * Split shadow pages too, because free(page[0]) would
1290 * otherwise free the whole shadow.
1292 if (kmemcheck_page_is_tracked(page
))
1293 split_page(virt_to_page(page
[0].shadow
), order
);
1296 for (i
= 1; i
< (1 << order
); i
++)
1297 set_page_refcounted(page
+ i
);
1301 * Similar to split_page except the page is already free. As this is only
1302 * being used for migration, the migratetype of the block also changes.
1303 * As this is called with interrupts disabled, the caller is responsible
1304 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1307 * Note: this is probably too low level an operation for use in drivers.
1308 * Please consult with lkml before using this in your driver.
1310 int split_free_page(struct page
*page
)
1313 unsigned long watermark
;
1316 BUG_ON(!PageBuddy(page
));
1318 zone
= page_zone(page
);
1319 order
= page_order(page
);
1321 /* Obey watermarks as if the page was being allocated */
1322 watermark
= low_wmark_pages(zone
) + (1 << order
);
1323 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
1326 /* Remove page from free list */
1327 list_del(&page
->lru
);
1328 zone
->free_area
[order
].nr_free
--;
1329 rmv_page_order(page
);
1330 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(1UL << order
));
1332 /* Split into individual pages */
1333 set_page_refcounted(page
);
1334 split_page(page
, order
);
1336 if (order
>= pageblock_order
- 1) {
1337 struct page
*endpage
= page
+ (1 << order
) - 1;
1338 for (; page
< endpage
; page
+= pageblock_nr_pages
)
1339 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1346 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1347 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1351 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
1352 struct zone
*zone
, int order
, gfp_t gfp_flags
,
1355 unsigned long flags
;
1357 int cold
= !!(gfp_flags
& __GFP_COLD
);
1360 if (likely(order
== 0)) {
1361 struct per_cpu_pages
*pcp
;
1362 struct list_head
*list
;
1364 local_irq_save(flags
);
1365 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1366 list
= &pcp
->lists
[migratetype
];
1367 if (list_empty(list
)) {
1368 pcp
->count
+= rmqueue_bulk(zone
, 0,
1371 if (unlikely(list_empty(list
)))
1376 page
= list_entry(list
->prev
, struct page
, lru
);
1378 page
= list_entry(list
->next
, struct page
, lru
);
1380 list_del(&page
->lru
);
1383 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
1385 * __GFP_NOFAIL is not to be used in new code.
1387 * All __GFP_NOFAIL callers should be fixed so that they
1388 * properly detect and handle allocation failures.
1390 * We most definitely don't want callers attempting to
1391 * allocate greater than order-1 page units with
1394 WARN_ON_ONCE(order
> 1);
1396 spin_lock_irqsave(&zone
->lock
, flags
);
1397 page
= __rmqueue(zone
, order
, migratetype
);
1398 spin_unlock(&zone
->lock
);
1401 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(1 << order
));
1404 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
1405 zone_statistics(preferred_zone
, zone
, gfp_flags
);
1406 local_irq_restore(flags
);
1408 VM_BUG_ON(bad_range(zone
, page
));
1409 if (prep_new_page(page
, order
, gfp_flags
))
1414 local_irq_restore(flags
);
1418 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
1419 #define ALLOC_WMARK_MIN WMARK_MIN
1420 #define ALLOC_WMARK_LOW WMARK_LOW
1421 #define ALLOC_WMARK_HIGH WMARK_HIGH
1422 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
1424 /* Mask to get the watermark bits */
1425 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
1427 #define ALLOC_HARDER 0x10 /* try to alloc harder */
1428 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
1429 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
1431 #ifdef CONFIG_FAIL_PAGE_ALLOC
1434 struct fault_attr attr
;
1436 u32 ignore_gfp_highmem
;
1437 u32 ignore_gfp_wait
;
1439 } fail_page_alloc
= {
1440 .attr
= FAULT_ATTR_INITIALIZER
,
1441 .ignore_gfp_wait
= 1,
1442 .ignore_gfp_highmem
= 1,
1446 static int __init
setup_fail_page_alloc(char *str
)
1448 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
1450 __setup("fail_page_alloc=", setup_fail_page_alloc
);
1452 static int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1454 if (order
< fail_page_alloc
.min_order
)
1456 if (gfp_mask
& __GFP_NOFAIL
)
1458 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
1460 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
1463 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
1466 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1468 static int __init
fail_page_alloc_debugfs(void)
1470 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
1473 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
1474 &fail_page_alloc
.attr
);
1476 return PTR_ERR(dir
);
1478 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
1479 &fail_page_alloc
.ignore_gfp_wait
))
1481 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
1482 &fail_page_alloc
.ignore_gfp_highmem
))
1484 if (!debugfs_create_u32("min-order", mode
, dir
,
1485 &fail_page_alloc
.min_order
))
1490 debugfs_remove_recursive(dir
);
1495 late_initcall(fail_page_alloc_debugfs
);
1497 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1499 #else /* CONFIG_FAIL_PAGE_ALLOC */
1501 static inline int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1506 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1509 * Return true if free pages are above 'mark'. This takes into account the order
1510 * of the allocation.
1512 static bool __zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1513 int classzone_idx
, int alloc_flags
, long free_pages
)
1515 /* free_pages my go negative - that's OK */
1519 free_pages
-= (1 << order
) - 1;
1520 if (alloc_flags
& ALLOC_HIGH
)
1522 if (alloc_flags
& ALLOC_HARDER
)
1525 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
1527 for (o
= 0; o
< order
; o
++) {
1528 /* At the next order, this order's pages become unavailable */
1529 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1531 /* Require fewer higher order pages to be free */
1534 if (free_pages
<= min
)
1540 bool zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1541 int classzone_idx
, int alloc_flags
)
1543 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1544 zone_page_state(z
, NR_FREE_PAGES
));
1547 bool zone_watermark_ok_safe(struct zone
*z
, int order
, unsigned long mark
,
1548 int classzone_idx
, int alloc_flags
)
1550 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
1552 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
1553 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
1555 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1561 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1562 * skip over zones that are not allowed by the cpuset, or that have
1563 * been recently (in last second) found to be nearly full. See further
1564 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1565 * that have to skip over a lot of full or unallowed zones.
1567 * If the zonelist cache is present in the passed in zonelist, then
1568 * returns a pointer to the allowed node mask (either the current
1569 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1571 * If the zonelist cache is not available for this zonelist, does
1572 * nothing and returns NULL.
1574 * If the fullzones BITMAP in the zonelist cache is stale (more than
1575 * a second since last zap'd) then we zap it out (clear its bits.)
1577 * We hold off even calling zlc_setup, until after we've checked the
1578 * first zone in the zonelist, on the theory that most allocations will
1579 * be satisfied from that first zone, so best to examine that zone as
1580 * quickly as we can.
1582 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1584 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1585 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1587 zlc
= zonelist
->zlcache_ptr
;
1591 if (time_after(jiffies
, zlc
->last_full_zap
+ HZ
)) {
1592 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1593 zlc
->last_full_zap
= jiffies
;
1596 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1597 &cpuset_current_mems_allowed
:
1598 &node_states
[N_HIGH_MEMORY
];
1599 return allowednodes
;
1603 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1604 * if it is worth looking at further for free memory:
1605 * 1) Check that the zone isn't thought to be full (doesn't have its
1606 * bit set in the zonelist_cache fullzones BITMAP).
1607 * 2) Check that the zones node (obtained from the zonelist_cache
1608 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1609 * Return true (non-zero) if zone is worth looking at further, or
1610 * else return false (zero) if it is not.
1612 * This check -ignores- the distinction between various watermarks,
1613 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1614 * found to be full for any variation of these watermarks, it will
1615 * be considered full for up to one second by all requests, unless
1616 * we are so low on memory on all allowed nodes that we are forced
1617 * into the second scan of the zonelist.
1619 * In the second scan we ignore this zonelist cache and exactly
1620 * apply the watermarks to all zones, even it is slower to do so.
1621 * We are low on memory in the second scan, and should leave no stone
1622 * unturned looking for a free page.
1624 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1625 nodemask_t
*allowednodes
)
1627 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1628 int i
; /* index of *z in zonelist zones */
1629 int n
; /* node that zone *z is on */
1631 zlc
= zonelist
->zlcache_ptr
;
1635 i
= z
- zonelist
->_zonerefs
;
1638 /* This zone is worth trying if it is allowed but not full */
1639 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1643 * Given 'z' scanning a zonelist, set the corresponding bit in
1644 * zlc->fullzones, so that subsequent attempts to allocate a page
1645 * from that zone don't waste time re-examining it.
1647 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1649 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1650 int i
; /* index of *z in zonelist zones */
1652 zlc
= zonelist
->zlcache_ptr
;
1656 i
= z
- zonelist
->_zonerefs
;
1658 set_bit(i
, zlc
->fullzones
);
1662 * clear all zones full, called after direct reclaim makes progress so that
1663 * a zone that was recently full is not skipped over for up to a second
1665 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
1667 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1669 zlc
= zonelist
->zlcache_ptr
;
1673 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1676 #else /* CONFIG_NUMA */
1678 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1683 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1684 nodemask_t
*allowednodes
)
1689 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1693 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
1696 #endif /* CONFIG_NUMA */
1699 * get_page_from_freelist goes through the zonelist trying to allocate
1702 static struct page
*
1703 get_page_from_freelist(gfp_t gfp_mask
, nodemask_t
*nodemask
, unsigned int order
,
1704 struct zonelist
*zonelist
, int high_zoneidx
, int alloc_flags
,
1705 struct zone
*preferred_zone
, int migratetype
)
1708 struct page
*page
= NULL
;
1711 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1712 int zlc_active
= 0; /* set if using zonelist_cache */
1713 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1715 classzone_idx
= zone_idx(preferred_zone
);
1718 * Scan zonelist, looking for a zone with enough free.
1719 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1721 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
1722 high_zoneidx
, nodemask
) {
1723 if (NUMA_BUILD
&& zlc_active
&&
1724 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1726 if ((alloc_flags
& ALLOC_CPUSET
) &&
1727 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1730 * When allocating a page cache page for writing, we
1731 * want to get it from a zone that is within its dirty
1732 * limit, such that no single zone holds more than its
1733 * proportional share of globally allowed dirty pages.
1734 * The dirty limits take into account the zone's
1735 * lowmem reserves and high watermark so that kswapd
1736 * should be able to balance it without having to
1737 * write pages from its LRU list.
1739 * This may look like it could increase pressure on
1740 * lower zones by failing allocations in higher zones
1741 * before they are full. But the pages that do spill
1742 * over are limited as the lower zones are protected
1743 * by this very same mechanism. It should not become
1744 * a practical burden to them.
1746 * XXX: For now, allow allocations to potentially
1747 * exceed the per-zone dirty limit in the slowpath
1748 * (ALLOC_WMARK_LOW unset) before going into reclaim,
1749 * which is important when on a NUMA setup the allowed
1750 * zones are together not big enough to reach the
1751 * global limit. The proper fix for these situations
1752 * will require awareness of zones in the
1753 * dirty-throttling and the flusher threads.
1755 if ((alloc_flags
& ALLOC_WMARK_LOW
) &&
1756 (gfp_mask
& __GFP_WRITE
) && !zone_dirty_ok(zone
))
1757 goto this_zone_full
;
1759 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
1760 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
1764 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
1765 if (zone_watermark_ok(zone
, order
, mark
,
1766 classzone_idx
, alloc_flags
))
1769 if (NUMA_BUILD
&& !did_zlc_setup
&& nr_online_nodes
> 1) {
1771 * we do zlc_setup if there are multiple nodes
1772 * and before considering the first zone allowed
1775 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1780 if (zone_reclaim_mode
== 0)
1781 goto this_zone_full
;
1784 * As we may have just activated ZLC, check if the first
1785 * eligible zone has failed zone_reclaim recently.
1787 if (NUMA_BUILD
&& zlc_active
&&
1788 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1791 ret
= zone_reclaim(zone
, gfp_mask
, order
);
1793 case ZONE_RECLAIM_NOSCAN
:
1796 case ZONE_RECLAIM_FULL
:
1797 /* scanned but unreclaimable */
1800 /* did we reclaim enough */
1801 if (!zone_watermark_ok(zone
, order
, mark
,
1802 classzone_idx
, alloc_flags
))
1803 goto this_zone_full
;
1808 page
= buffered_rmqueue(preferred_zone
, zone
, order
,
1809 gfp_mask
, migratetype
);
1814 zlc_mark_zone_full(zonelist
, z
);
1817 if (unlikely(NUMA_BUILD
&& page
== NULL
&& zlc_active
)) {
1818 /* Disable zlc cache for second zonelist scan */
1826 * Large machines with many possible nodes should not always dump per-node
1827 * meminfo in irq context.
1829 static inline bool should_suppress_show_mem(void)
1834 ret
= in_interrupt();
1839 static DEFINE_RATELIMIT_STATE(nopage_rs
,
1840 DEFAULT_RATELIMIT_INTERVAL
,
1841 DEFAULT_RATELIMIT_BURST
);
1843 void warn_alloc_failed(gfp_t gfp_mask
, int order
, const char *fmt
, ...)
1845 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
1847 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
1848 debug_guardpage_minorder() > 0)
1852 * This documents exceptions given to allocations in certain
1853 * contexts that are allowed to allocate outside current's set
1856 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
1857 if (test_thread_flag(TIF_MEMDIE
) ||
1858 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
1859 filter
&= ~SHOW_MEM_FILTER_NODES
;
1860 if (in_interrupt() || !(gfp_mask
& __GFP_WAIT
))
1861 filter
&= ~SHOW_MEM_FILTER_NODES
;
1864 struct va_format vaf
;
1867 va_start(args
, fmt
);
1872 pr_warn("%pV", &vaf
);
1877 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
1878 current
->comm
, order
, gfp_mask
);
1881 if (!should_suppress_show_mem())
1886 should_alloc_retry(gfp_t gfp_mask
, unsigned int order
,
1887 unsigned long did_some_progress
,
1888 unsigned long pages_reclaimed
)
1890 /* Do not loop if specifically requested */
1891 if (gfp_mask
& __GFP_NORETRY
)
1894 /* Always retry if specifically requested */
1895 if (gfp_mask
& __GFP_NOFAIL
)
1899 * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
1900 * making forward progress without invoking OOM. Suspend also disables
1901 * storage devices so kswapd will not help. Bail if we are suspending.
1903 if (!did_some_progress
&& pm_suspended_storage())
1907 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
1908 * means __GFP_NOFAIL, but that may not be true in other
1911 if (order
<= PAGE_ALLOC_COSTLY_ORDER
)
1915 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
1916 * specified, then we retry until we no longer reclaim any pages
1917 * (above), or we've reclaimed an order of pages at least as
1918 * large as the allocation's order. In both cases, if the
1919 * allocation still fails, we stop retrying.
1921 if (gfp_mask
& __GFP_REPEAT
&& pages_reclaimed
< (1 << order
))
1927 static inline struct page
*
1928 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
1929 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1930 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
1935 /* Acquire the OOM killer lock for the zones in zonelist */
1936 if (!try_set_zonelist_oom(zonelist
, gfp_mask
)) {
1937 schedule_timeout_uninterruptible(1);
1942 * Go through the zonelist yet one more time, keep very high watermark
1943 * here, this is only to catch a parallel oom killing, we must fail if
1944 * we're still under heavy pressure.
1946 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
,
1947 order
, zonelist
, high_zoneidx
,
1948 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
,
1949 preferred_zone
, migratetype
);
1953 if (!(gfp_mask
& __GFP_NOFAIL
)) {
1954 /* The OOM killer will not help higher order allocs */
1955 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
1957 /* The OOM killer does not needlessly kill tasks for lowmem */
1958 if (high_zoneidx
< ZONE_NORMAL
)
1961 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
1962 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
1963 * The caller should handle page allocation failure by itself if
1964 * it specifies __GFP_THISNODE.
1965 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
1967 if (gfp_mask
& __GFP_THISNODE
)
1970 /* Exhausted what can be done so it's blamo time */
1971 out_of_memory(zonelist
, gfp_mask
, order
, nodemask
);
1974 clear_zonelist_oom(zonelist
, gfp_mask
);
1978 #ifdef CONFIG_COMPACTION
1979 /* Try memory compaction for high-order allocations before reclaim */
1980 static struct page
*
1981 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
1982 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1983 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
1984 int migratetype
, unsigned long *did_some_progress
,
1985 bool sync_migration
)
1989 if (!order
|| compaction_deferred(preferred_zone
))
1992 current
->flags
|= PF_MEMALLOC
;
1993 *did_some_progress
= try_to_compact_pages(zonelist
, order
, gfp_mask
,
1994 nodemask
, sync_migration
);
1995 current
->flags
&= ~PF_MEMALLOC
;
1996 if (*did_some_progress
!= COMPACT_SKIPPED
) {
1998 /* Page migration frees to the PCP lists but we want merging */
1999 drain_pages(get_cpu());
2002 page
= get_page_from_freelist(gfp_mask
, nodemask
,
2003 order
, zonelist
, high_zoneidx
,
2004 alloc_flags
, preferred_zone
,
2007 preferred_zone
->compact_considered
= 0;
2008 preferred_zone
->compact_defer_shift
= 0;
2009 count_vm_event(COMPACTSUCCESS
);
2014 * It's bad if compaction run occurs and fails.
2015 * The most likely reason is that pages exist,
2016 * but not enough to satisfy watermarks.
2018 count_vm_event(COMPACTFAIL
);
2019 defer_compaction(preferred_zone
);
2027 static inline struct page
*
2028 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2029 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2030 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2031 int migratetype
, unsigned long *did_some_progress
,
2032 bool sync_migration
)
2036 #endif /* CONFIG_COMPACTION */
2038 /* The really slow allocator path where we enter direct reclaim */
2039 static inline struct page
*
2040 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
2041 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2042 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2043 int migratetype
, unsigned long *did_some_progress
)
2045 struct page
*page
= NULL
;
2046 struct reclaim_state reclaim_state
;
2047 bool drained
= false;
2051 /* We now go into synchronous reclaim */
2052 cpuset_memory_pressure_bump();
2053 current
->flags
|= PF_MEMALLOC
;
2054 lockdep_set_current_reclaim_state(gfp_mask
);
2055 reclaim_state
.reclaimed_slab
= 0;
2056 current
->reclaim_state
= &reclaim_state
;
2058 *did_some_progress
= try_to_free_pages(zonelist
, order
, gfp_mask
, nodemask
);
2060 current
->reclaim_state
= NULL
;
2061 lockdep_clear_current_reclaim_state();
2062 current
->flags
&= ~PF_MEMALLOC
;
2066 if (unlikely(!(*did_some_progress
)))
2069 /* After successful reclaim, reconsider all zones for allocation */
2071 zlc_clear_zones_full(zonelist
);
2074 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
2075 zonelist
, high_zoneidx
,
2076 alloc_flags
, preferred_zone
,
2080 * If an allocation failed after direct reclaim, it could be because
2081 * pages are pinned on the per-cpu lists. Drain them and try again
2083 if (!page
&& !drained
) {
2093 * This is called in the allocator slow-path if the allocation request is of
2094 * sufficient urgency to ignore watermarks and take other desperate measures
2096 static inline struct page
*
2097 __alloc_pages_high_priority(gfp_t gfp_mask
, unsigned int order
,
2098 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2099 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2105 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
2106 zonelist
, high_zoneidx
, ALLOC_NO_WATERMARKS
,
2107 preferred_zone
, migratetype
);
2109 if (!page
&& gfp_mask
& __GFP_NOFAIL
)
2110 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2111 } while (!page
&& (gfp_mask
& __GFP_NOFAIL
));
2117 void wake_all_kswapd(unsigned int order
, struct zonelist
*zonelist
,
2118 enum zone_type high_zoneidx
,
2119 enum zone_type classzone_idx
)
2124 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
)
2125 wakeup_kswapd(zone
, order
, classzone_idx
);
2129 gfp_to_alloc_flags(gfp_t gfp_mask
)
2131 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
2132 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2134 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2135 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
2138 * The caller may dip into page reserves a bit more if the caller
2139 * cannot run direct reclaim, or if the caller has realtime scheduling
2140 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2141 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
2143 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
2147 * Not worth trying to allocate harder for
2148 * __GFP_NOMEMALLOC even if it can't schedule.
2150 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2151 alloc_flags
|= ALLOC_HARDER
;
2153 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
2154 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
2156 alloc_flags
&= ~ALLOC_CPUSET
;
2157 } else if (unlikely(rt_task(current
)) && !in_interrupt())
2158 alloc_flags
|= ALLOC_HARDER
;
2160 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
2161 if (!in_interrupt() &&
2162 ((current
->flags
& PF_MEMALLOC
) ||
2163 unlikely(test_thread_flag(TIF_MEMDIE
))))
2164 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2170 static inline struct page
*
2171 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
2172 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2173 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2176 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2177 struct page
*page
= NULL
;
2179 unsigned long pages_reclaimed
= 0;
2180 unsigned long did_some_progress
;
2181 bool sync_migration
= false;
2184 * In the slowpath, we sanity check order to avoid ever trying to
2185 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2186 * be using allocators in order of preference for an area that is
2189 if (order
>= MAX_ORDER
) {
2190 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
2195 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
2196 * __GFP_NOWARN set) should not cause reclaim since the subsystem
2197 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
2198 * using a larger set of nodes after it has established that the
2199 * allowed per node queues are empty and that nodes are
2202 if (NUMA_BUILD
&& (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
2206 if (!(gfp_mask
& __GFP_NO_KSWAPD
))
2207 wake_all_kswapd(order
, zonelist
, high_zoneidx
,
2208 zone_idx(preferred_zone
));
2211 * OK, we're below the kswapd watermark and have kicked background
2212 * reclaim. Now things get more complex, so set up alloc_flags according
2213 * to how we want to proceed.
2215 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
2218 * Find the true preferred zone if the allocation is unconstrained by
2221 if (!(alloc_flags
& ALLOC_CPUSET
) && !nodemask
)
2222 first_zones_zonelist(zonelist
, high_zoneidx
, NULL
,
2226 /* This is the last chance, in general, before the goto nopage. */
2227 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
, zonelist
,
2228 high_zoneidx
, alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2229 preferred_zone
, migratetype
);
2233 /* Allocate without watermarks if the context allows */
2234 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
2235 page
= __alloc_pages_high_priority(gfp_mask
, order
,
2236 zonelist
, high_zoneidx
, nodemask
,
2237 preferred_zone
, migratetype
);
2242 /* Atomic allocations - we can't balance anything */
2246 /* Avoid recursion of direct reclaim */
2247 if (current
->flags
& PF_MEMALLOC
)
2250 /* Avoid allocations with no watermarks from looping endlessly */
2251 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
2255 * Try direct compaction. The first pass is asynchronous. Subsequent
2256 * attempts after direct reclaim are synchronous
2258 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
2259 zonelist
, high_zoneidx
,
2261 alloc_flags
, preferred_zone
,
2262 migratetype
, &did_some_progress
,
2266 sync_migration
= true;
2268 /* Try direct reclaim and then allocating */
2269 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
,
2270 zonelist
, high_zoneidx
,
2272 alloc_flags
, preferred_zone
,
2273 migratetype
, &did_some_progress
);
2278 * If we failed to make any progress reclaiming, then we are
2279 * running out of options and have to consider going OOM
2281 if (!did_some_progress
) {
2282 if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
2283 if (oom_killer_disabled
)
2285 page
= __alloc_pages_may_oom(gfp_mask
, order
,
2286 zonelist
, high_zoneidx
,
2287 nodemask
, preferred_zone
,
2292 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2294 * The oom killer is not called for high-order
2295 * allocations that may fail, so if no progress
2296 * is being made, there are no other options and
2297 * retrying is unlikely to help.
2299 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2302 * The oom killer is not called for lowmem
2303 * allocations to prevent needlessly killing
2306 if (high_zoneidx
< ZONE_NORMAL
)
2314 /* Check if we should retry the allocation */
2315 pages_reclaimed
+= did_some_progress
;
2316 if (should_alloc_retry(gfp_mask
, order
, did_some_progress
,
2318 /* Wait for some write requests to complete then retry */
2319 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2323 * High-order allocations do not necessarily loop after
2324 * direct reclaim and reclaim/compaction depends on compaction
2325 * being called after reclaim so call directly if necessary
2327 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
2328 zonelist
, high_zoneidx
,
2330 alloc_flags
, preferred_zone
,
2331 migratetype
, &did_some_progress
,
2338 warn_alloc_failed(gfp_mask
, order
, NULL
);
2341 if (kmemcheck_enabled
)
2342 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
2348 * This is the 'heart' of the zoned buddy allocator.
2351 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
2352 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
2354 enum zone_type high_zoneidx
= gfp_zone(gfp_mask
);
2355 struct zone
*preferred_zone
;
2357 int migratetype
= allocflags_to_migratetype(gfp_mask
);
2359 gfp_mask
&= gfp_allowed_mask
;
2361 lockdep_trace_alloc(gfp_mask
);
2363 might_sleep_if(gfp_mask
& __GFP_WAIT
);
2365 if (should_fail_alloc_page(gfp_mask
, order
))
2369 * Check the zones suitable for the gfp_mask contain at least one
2370 * valid zone. It's possible to have an empty zonelist as a result
2371 * of GFP_THISNODE and a memoryless node
2373 if (unlikely(!zonelist
->_zonerefs
->zone
))
2377 /* The preferred zone is used for statistics later */
2378 first_zones_zonelist(zonelist
, high_zoneidx
,
2379 nodemask
? : &cpuset_current_mems_allowed
,
2381 if (!preferred_zone
) {
2386 /* First allocation attempt */
2387 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
, order
,
2388 zonelist
, high_zoneidx
, ALLOC_WMARK_LOW
|ALLOC_CPUSET
,
2389 preferred_zone
, migratetype
);
2390 if (unlikely(!page
))
2391 page
= __alloc_pages_slowpath(gfp_mask
, order
,
2392 zonelist
, high_zoneidx
, nodemask
,
2393 preferred_zone
, migratetype
);
2396 trace_mm_page_alloc(page
, order
, gfp_mask
, migratetype
);
2399 EXPORT_SYMBOL(__alloc_pages_nodemask
);
2402 * Common helper functions.
2404 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
2409 * __get_free_pages() returns a 32-bit address, which cannot represent
2412 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
2414 page
= alloc_pages(gfp_mask
, order
);
2417 return (unsigned long) page_address(page
);
2419 EXPORT_SYMBOL(__get_free_pages
);
2421 unsigned long get_zeroed_page(gfp_t gfp_mask
)
2423 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
2425 EXPORT_SYMBOL(get_zeroed_page
);
2427 void __free_pages(struct page
*page
, unsigned int order
)
2429 if (put_page_testzero(page
)) {
2431 free_hot_cold_page(page
, 0);
2433 __free_pages_ok(page
, order
);
2437 EXPORT_SYMBOL(__free_pages
);
2439 void free_pages(unsigned long addr
, unsigned int order
)
2442 VM_BUG_ON(!virt_addr_valid((void *)addr
));
2443 __free_pages(virt_to_page((void *)addr
), order
);
2447 EXPORT_SYMBOL(free_pages
);
2449 static void *make_alloc_exact(unsigned long addr
, unsigned order
, size_t size
)
2452 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
2453 unsigned long used
= addr
+ PAGE_ALIGN(size
);
2455 split_page(virt_to_page((void *)addr
), order
);
2456 while (used
< alloc_end
) {
2461 return (void *)addr
;
2465 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2466 * @size: the number of bytes to allocate
2467 * @gfp_mask: GFP flags for the allocation
2469 * This function is similar to alloc_pages(), except that it allocates the
2470 * minimum number of pages to satisfy the request. alloc_pages() can only
2471 * allocate memory in power-of-two pages.
2473 * This function is also limited by MAX_ORDER.
2475 * Memory allocated by this function must be released by free_pages_exact().
2477 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
2479 unsigned int order
= get_order(size
);
2482 addr
= __get_free_pages(gfp_mask
, order
);
2483 return make_alloc_exact(addr
, order
, size
);
2485 EXPORT_SYMBOL(alloc_pages_exact
);
2488 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
2490 * @nid: the preferred node ID where memory should be allocated
2491 * @size: the number of bytes to allocate
2492 * @gfp_mask: GFP flags for the allocation
2494 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
2496 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
2499 void *alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
2501 unsigned order
= get_order(size
);
2502 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
2505 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
2507 EXPORT_SYMBOL(alloc_pages_exact_nid
);
2510 * free_pages_exact - release memory allocated via alloc_pages_exact()
2511 * @virt: the value returned by alloc_pages_exact.
2512 * @size: size of allocation, same value as passed to alloc_pages_exact().
2514 * Release the memory allocated by a previous call to alloc_pages_exact.
2516 void free_pages_exact(void *virt
, size_t size
)
2518 unsigned long addr
= (unsigned long)virt
;
2519 unsigned long end
= addr
+ PAGE_ALIGN(size
);
2521 while (addr
< end
) {
2526 EXPORT_SYMBOL(free_pages_exact
);
2528 static unsigned int nr_free_zone_pages(int offset
)
2533 /* Just pick one node, since fallback list is circular */
2534 unsigned int sum
= 0;
2536 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
2538 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
2539 unsigned long size
= zone
->present_pages
;
2540 unsigned long high
= high_wmark_pages(zone
);
2549 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
2551 unsigned int nr_free_buffer_pages(void)
2553 return nr_free_zone_pages(gfp_zone(GFP_USER
));
2555 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
2558 * Amount of free RAM allocatable within all zones
2560 unsigned int nr_free_pagecache_pages(void)
2562 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
2565 static inline void show_node(struct zone
*zone
)
2568 printk("Node %d ", zone_to_nid(zone
));
2571 void si_meminfo(struct sysinfo
*val
)
2573 val
->totalram
= totalram_pages
;
2575 val
->freeram
= global_page_state(NR_FREE_PAGES
);
2576 val
->bufferram
= nr_blockdev_pages();
2577 val
->totalhigh
= totalhigh_pages
;
2578 val
->freehigh
= nr_free_highpages();
2579 val
->mem_unit
= PAGE_SIZE
;
2582 EXPORT_SYMBOL(si_meminfo
);
2585 void si_meminfo_node(struct sysinfo
*val
, int nid
)
2587 pg_data_t
*pgdat
= NODE_DATA(nid
);
2589 val
->totalram
= pgdat
->node_present_pages
;
2590 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
2591 #ifdef CONFIG_HIGHMEM
2592 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
2593 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
2599 val
->mem_unit
= PAGE_SIZE
;
2604 * Determine whether the node should be displayed or not, depending on whether
2605 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
2607 bool skip_free_areas_node(unsigned int flags
, int nid
)
2611 if (!(flags
& SHOW_MEM_FILTER_NODES
))
2615 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
2621 #define K(x) ((x) << (PAGE_SHIFT-10))
2624 * Show free area list (used inside shift_scroll-lock stuff)
2625 * We also calculate the percentage fragmentation. We do this by counting the
2626 * memory on each free list with the exception of the first item on the list.
2627 * Suppresses nodes that are not allowed by current's cpuset if
2628 * SHOW_MEM_FILTER_NODES is passed.
2630 void show_free_areas(unsigned int filter
)
2635 for_each_populated_zone(zone
) {
2636 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
2639 printk("%s per-cpu:\n", zone
->name
);
2641 for_each_online_cpu(cpu
) {
2642 struct per_cpu_pageset
*pageset
;
2644 pageset
= per_cpu_ptr(zone
->pageset
, cpu
);
2646 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
2647 cpu
, pageset
->pcp
.high
,
2648 pageset
->pcp
.batch
, pageset
->pcp
.count
);
2652 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
2653 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
2655 " dirty:%lu writeback:%lu unstable:%lu\n"
2656 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2657 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
2658 global_page_state(NR_ACTIVE_ANON
),
2659 global_page_state(NR_INACTIVE_ANON
),
2660 global_page_state(NR_ISOLATED_ANON
),
2661 global_page_state(NR_ACTIVE_FILE
),
2662 global_page_state(NR_INACTIVE_FILE
),
2663 global_page_state(NR_ISOLATED_FILE
),
2664 global_page_state(NR_UNEVICTABLE
),
2665 global_page_state(NR_FILE_DIRTY
),
2666 global_page_state(NR_WRITEBACK
),
2667 global_page_state(NR_UNSTABLE_NFS
),
2668 global_page_state(NR_FREE_PAGES
),
2669 global_page_state(NR_SLAB_RECLAIMABLE
),
2670 global_page_state(NR_SLAB_UNRECLAIMABLE
),
2671 global_page_state(NR_FILE_MAPPED
),
2672 global_page_state(NR_SHMEM
),
2673 global_page_state(NR_PAGETABLE
),
2674 global_page_state(NR_BOUNCE
));
2676 for_each_populated_zone(zone
) {
2679 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
2687 " active_anon:%lukB"
2688 " inactive_anon:%lukB"
2689 " active_file:%lukB"
2690 " inactive_file:%lukB"
2691 " unevictable:%lukB"
2692 " isolated(anon):%lukB"
2693 " isolated(file):%lukB"
2700 " slab_reclaimable:%lukB"
2701 " slab_unreclaimable:%lukB"
2702 " kernel_stack:%lukB"
2706 " writeback_tmp:%lukB"
2707 " pages_scanned:%lu"
2708 " all_unreclaimable? %s"
2711 K(zone_page_state(zone
, NR_FREE_PAGES
)),
2712 K(min_wmark_pages(zone
)),
2713 K(low_wmark_pages(zone
)),
2714 K(high_wmark_pages(zone
)),
2715 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
2716 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
2717 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
2718 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
2719 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
2720 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
2721 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
2722 K(zone
->present_pages
),
2723 K(zone_page_state(zone
, NR_MLOCK
)),
2724 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
2725 K(zone_page_state(zone
, NR_WRITEBACK
)),
2726 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
2727 K(zone_page_state(zone
, NR_SHMEM
)),
2728 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
2729 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
2730 zone_page_state(zone
, NR_KERNEL_STACK
) *
2732 K(zone_page_state(zone
, NR_PAGETABLE
)),
2733 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
2734 K(zone_page_state(zone
, NR_BOUNCE
)),
2735 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
2736 zone
->pages_scanned
,
2737 (zone
->all_unreclaimable
? "yes" : "no")
2739 printk("lowmem_reserve[]:");
2740 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
2741 printk(" %lu", zone
->lowmem_reserve
[i
]);
2745 for_each_populated_zone(zone
) {
2746 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
2748 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
2751 printk("%s: ", zone
->name
);
2753 spin_lock_irqsave(&zone
->lock
, flags
);
2754 for (order
= 0; order
< MAX_ORDER
; order
++) {
2755 nr
[order
] = zone
->free_area
[order
].nr_free
;
2756 total
+= nr
[order
] << order
;
2758 spin_unlock_irqrestore(&zone
->lock
, flags
);
2759 for (order
= 0; order
< MAX_ORDER
; order
++)
2760 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
2761 printk("= %lukB\n", K(total
));
2764 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
2766 show_swap_cache_info();
2769 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
2771 zoneref
->zone
= zone
;
2772 zoneref
->zone_idx
= zone_idx(zone
);
2776 * Builds allocation fallback zone lists.
2778 * Add all populated zones of a node to the zonelist.
2780 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
2781 int nr_zones
, enum zone_type zone_type
)
2785 BUG_ON(zone_type
>= MAX_NR_ZONES
);
2790 zone
= pgdat
->node_zones
+ zone_type
;
2791 if (populated_zone(zone
)) {
2792 zoneref_set_zone(zone
,
2793 &zonelist
->_zonerefs
[nr_zones
++]);
2794 check_highest_zone(zone_type
);
2797 } while (zone_type
);
2804 * 0 = automatic detection of better ordering.
2805 * 1 = order by ([node] distance, -zonetype)
2806 * 2 = order by (-zonetype, [node] distance)
2808 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
2809 * the same zonelist. So only NUMA can configure this param.
2811 #define ZONELIST_ORDER_DEFAULT 0
2812 #define ZONELIST_ORDER_NODE 1
2813 #define ZONELIST_ORDER_ZONE 2
2815 /* zonelist order in the kernel.
2816 * set_zonelist_order() will set this to NODE or ZONE.
2818 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2819 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
2823 /* The value user specified ....changed by config */
2824 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2825 /* string for sysctl */
2826 #define NUMA_ZONELIST_ORDER_LEN 16
2827 char numa_zonelist_order
[16] = "default";
2830 * interface for configure zonelist ordering.
2831 * command line option "numa_zonelist_order"
2832 * = "[dD]efault - default, automatic configuration.
2833 * = "[nN]ode - order by node locality, then by zone within node
2834 * = "[zZ]one - order by zone, then by locality within zone
2837 static int __parse_numa_zonelist_order(char *s
)
2839 if (*s
== 'd' || *s
== 'D') {
2840 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2841 } else if (*s
== 'n' || *s
== 'N') {
2842 user_zonelist_order
= ZONELIST_ORDER_NODE
;
2843 } else if (*s
== 'z' || *s
== 'Z') {
2844 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
2847 "Ignoring invalid numa_zonelist_order value: "
2854 static __init
int setup_numa_zonelist_order(char *s
)
2861 ret
= __parse_numa_zonelist_order(s
);
2863 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
2867 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
2870 * sysctl handler for numa_zonelist_order
2872 int numa_zonelist_order_handler(ctl_table
*table
, int write
,
2873 void __user
*buffer
, size_t *length
,
2876 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
2878 static DEFINE_MUTEX(zl_order_mutex
);
2880 mutex_lock(&zl_order_mutex
);
2882 strcpy(saved_string
, (char*)table
->data
);
2883 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
2887 int oldval
= user_zonelist_order
;
2888 if (__parse_numa_zonelist_order((char*)table
->data
)) {
2890 * bogus value. restore saved string
2892 strncpy((char*)table
->data
, saved_string
,
2893 NUMA_ZONELIST_ORDER_LEN
);
2894 user_zonelist_order
= oldval
;
2895 } else if (oldval
!= user_zonelist_order
) {
2896 mutex_lock(&zonelists_mutex
);
2897 build_all_zonelists(NULL
);
2898 mutex_unlock(&zonelists_mutex
);
2902 mutex_unlock(&zl_order_mutex
);
2907 #define MAX_NODE_LOAD (nr_online_nodes)
2908 static int node_load
[MAX_NUMNODES
];
2911 * find_next_best_node - find the next node that should appear in a given node's fallback list
2912 * @node: node whose fallback list we're appending
2913 * @used_node_mask: nodemask_t of already used nodes
2915 * We use a number of factors to determine which is the next node that should
2916 * appear on a given node's fallback list. The node should not have appeared
2917 * already in @node's fallback list, and it should be the next closest node
2918 * according to the distance array (which contains arbitrary distance values
2919 * from each node to each node in the system), and should also prefer nodes
2920 * with no CPUs, since presumably they'll have very little allocation pressure
2921 * on them otherwise.
2922 * It returns -1 if no node is found.
2924 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
2927 int min_val
= INT_MAX
;
2929 const struct cpumask
*tmp
= cpumask_of_node(0);
2931 /* Use the local node if we haven't already */
2932 if (!node_isset(node
, *used_node_mask
)) {
2933 node_set(node
, *used_node_mask
);
2937 for_each_node_state(n
, N_HIGH_MEMORY
) {
2939 /* Don't want a node to appear more than once */
2940 if (node_isset(n
, *used_node_mask
))
2943 /* Use the distance array to find the distance */
2944 val
= node_distance(node
, n
);
2946 /* Penalize nodes under us ("prefer the next node") */
2949 /* Give preference to headless and unused nodes */
2950 tmp
= cpumask_of_node(n
);
2951 if (!cpumask_empty(tmp
))
2952 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
2954 /* Slight preference for less loaded node */
2955 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
2956 val
+= node_load
[n
];
2958 if (val
< min_val
) {
2965 node_set(best_node
, *used_node_mask
);
2972 * Build zonelists ordered by node and zones within node.
2973 * This results in maximum locality--normal zone overflows into local
2974 * DMA zone, if any--but risks exhausting DMA zone.
2976 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
2979 struct zonelist
*zonelist
;
2981 zonelist
= &pgdat
->node_zonelists
[0];
2982 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
2984 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2986 zonelist
->_zonerefs
[j
].zone
= NULL
;
2987 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2991 * Build gfp_thisnode zonelists
2993 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
2996 struct zonelist
*zonelist
;
2998 zonelist
= &pgdat
->node_zonelists
[1];
2999 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
3000 zonelist
->_zonerefs
[j
].zone
= NULL
;
3001 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3005 * Build zonelists ordered by zone and nodes within zones.
3006 * This results in conserving DMA zone[s] until all Normal memory is
3007 * exhausted, but results in overflowing to remote node while memory
3008 * may still exist in local DMA zone.
3010 static int node_order
[MAX_NUMNODES
];
3012 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
3015 int zone_type
; /* needs to be signed */
3017 struct zonelist
*zonelist
;
3019 zonelist
= &pgdat
->node_zonelists
[0];
3021 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
3022 for (j
= 0; j
< nr_nodes
; j
++) {
3023 node
= node_order
[j
];
3024 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
3025 if (populated_zone(z
)) {
3027 &zonelist
->_zonerefs
[pos
++]);
3028 check_highest_zone(zone_type
);
3032 zonelist
->_zonerefs
[pos
].zone
= NULL
;
3033 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
3036 static int default_zonelist_order(void)
3039 unsigned long low_kmem_size
,total_size
;
3043 * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
3044 * If they are really small and used heavily, the system can fall
3045 * into OOM very easily.
3046 * This function detect ZONE_DMA/DMA32 size and configures zone order.
3048 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
3051 for_each_online_node(nid
) {
3052 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
3053 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
3054 if (populated_zone(z
)) {
3055 if (zone_type
< ZONE_NORMAL
)
3056 low_kmem_size
+= z
->present_pages
;
3057 total_size
+= z
->present_pages
;
3058 } else if (zone_type
== ZONE_NORMAL
) {
3060 * If any node has only lowmem, then node order
3061 * is preferred to allow kernel allocations
3062 * locally; otherwise, they can easily infringe
3063 * on other nodes when there is an abundance of
3064 * lowmem available to allocate from.
3066 return ZONELIST_ORDER_NODE
;
3070 if (!low_kmem_size
|| /* there are no DMA area. */
3071 low_kmem_size
> total_size
/2) /* DMA/DMA32 is big. */
3072 return ZONELIST_ORDER_NODE
;
3074 * look into each node's config.
3075 * If there is a node whose DMA/DMA32 memory is very big area on
3076 * local memory, NODE_ORDER may be suitable.
3078 average_size
= total_size
/
3079 (nodes_weight(node_states
[N_HIGH_MEMORY
]) + 1);
3080 for_each_online_node(nid
) {
3083 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
3084 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
3085 if (populated_zone(z
)) {
3086 if (zone_type
< ZONE_NORMAL
)
3087 low_kmem_size
+= z
->present_pages
;
3088 total_size
+= z
->present_pages
;
3091 if (low_kmem_size
&&
3092 total_size
> average_size
&& /* ignore small node */
3093 low_kmem_size
> total_size
* 70/100)
3094 return ZONELIST_ORDER_NODE
;
3096 return ZONELIST_ORDER_ZONE
;
3099 static void set_zonelist_order(void)
3101 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
3102 current_zonelist_order
= default_zonelist_order();
3104 current_zonelist_order
= user_zonelist_order
;
3107 static void build_zonelists(pg_data_t
*pgdat
)
3111 nodemask_t used_mask
;
3112 int local_node
, prev_node
;
3113 struct zonelist
*zonelist
;
3114 int order
= current_zonelist_order
;
3116 /* initialize zonelists */
3117 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
3118 zonelist
= pgdat
->node_zonelists
+ i
;
3119 zonelist
->_zonerefs
[0].zone
= NULL
;
3120 zonelist
->_zonerefs
[0].zone_idx
= 0;
3123 /* NUMA-aware ordering of nodes */
3124 local_node
= pgdat
->node_id
;
3125 load
= nr_online_nodes
;
3126 prev_node
= local_node
;
3127 nodes_clear(used_mask
);
3129 memset(node_order
, 0, sizeof(node_order
));
3132 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
3133 int distance
= node_distance(local_node
, node
);
3136 * If another node is sufficiently far away then it is better
3137 * to reclaim pages in a zone before going off node.
3139 if (distance
> RECLAIM_DISTANCE
)
3140 zone_reclaim_mode
= 1;
3143 * We don't want to pressure a particular node.
3144 * So adding penalty to the first node in same
3145 * distance group to make it round-robin.
3147 if (distance
!= node_distance(local_node
, prev_node
))
3148 node_load
[node
] = load
;
3152 if (order
== ZONELIST_ORDER_NODE
)
3153 build_zonelists_in_node_order(pgdat
, node
);
3155 node_order
[j
++] = node
; /* remember order */
3158 if (order
== ZONELIST_ORDER_ZONE
) {
3159 /* calculate node order -- i.e., DMA last! */
3160 build_zonelists_in_zone_order(pgdat
, j
);
3163 build_thisnode_zonelists(pgdat
);
3166 /* Construct the zonelist performance cache - see further mmzone.h */
3167 static void build_zonelist_cache(pg_data_t
*pgdat
)
3169 struct zonelist
*zonelist
;
3170 struct zonelist_cache
*zlc
;
3173 zonelist
= &pgdat
->node_zonelists
[0];
3174 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
3175 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
3176 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
3177 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
3180 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3182 * Return node id of node used for "local" allocations.
3183 * I.e., first node id of first zone in arg node's generic zonelist.
3184 * Used for initializing percpu 'numa_mem', which is used primarily
3185 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3187 int local_memory_node(int node
)
3191 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
3192 gfp_zone(GFP_KERNEL
),
3199 #else /* CONFIG_NUMA */
3201 static void set_zonelist_order(void)
3203 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
3206 static void build_zonelists(pg_data_t
*pgdat
)
3208 int node
, local_node
;
3210 struct zonelist
*zonelist
;
3212 local_node
= pgdat
->node_id
;
3214 zonelist
= &pgdat
->node_zonelists
[0];
3215 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
3218 * Now we build the zonelist so that it contains the zones
3219 * of all the other nodes.
3220 * We don't want to pressure a particular node, so when
3221 * building the zones for node N, we make sure that the
3222 * zones coming right after the local ones are those from
3223 * node N+1 (modulo N)
3225 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
3226 if (!node_online(node
))
3228 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3231 for (node
= 0; node
< local_node
; node
++) {
3232 if (!node_online(node
))
3234 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3238 zonelist
->_zonerefs
[j
].zone
= NULL
;
3239 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3242 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3243 static void build_zonelist_cache(pg_data_t
*pgdat
)
3245 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
3248 #endif /* CONFIG_NUMA */
3251 * Boot pageset table. One per cpu which is going to be used for all
3252 * zones and all nodes. The parameters will be set in such a way
3253 * that an item put on a list will immediately be handed over to
3254 * the buddy list. This is safe since pageset manipulation is done
3255 * with interrupts disabled.
3257 * The boot_pagesets must be kept even after bootup is complete for
3258 * unused processors and/or zones. They do play a role for bootstrapping
3259 * hotplugged processors.
3261 * zoneinfo_show() and maybe other functions do
3262 * not check if the processor is online before following the pageset pointer.
3263 * Other parts of the kernel may not check if the zone is available.
3265 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
3266 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
3267 static void setup_zone_pageset(struct zone
*zone
);
3270 * Global mutex to protect against size modification of zonelists
3271 * as well as to serialize pageset setup for the new populated zone.
3273 DEFINE_MUTEX(zonelists_mutex
);
3275 /* return values int ....just for stop_machine() */
3276 static __init_refok
int __build_all_zonelists(void *data
)
3282 memset(node_load
, 0, sizeof(node_load
));
3284 for_each_online_node(nid
) {
3285 pg_data_t
*pgdat
= NODE_DATA(nid
);
3287 build_zonelists(pgdat
);
3288 build_zonelist_cache(pgdat
);
3292 * Initialize the boot_pagesets that are going to be used
3293 * for bootstrapping processors. The real pagesets for
3294 * each zone will be allocated later when the per cpu
3295 * allocator is available.
3297 * boot_pagesets are used also for bootstrapping offline
3298 * cpus if the system is already booted because the pagesets
3299 * are needed to initialize allocators on a specific cpu too.
3300 * F.e. the percpu allocator needs the page allocator which
3301 * needs the percpu allocator in order to allocate its pagesets
3302 * (a chicken-egg dilemma).
3304 for_each_possible_cpu(cpu
) {
3305 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
3307 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3309 * We now know the "local memory node" for each node--
3310 * i.e., the node of the first zone in the generic zonelist.
3311 * Set up numa_mem percpu variable for on-line cpus. During
3312 * boot, only the boot cpu should be on-line; we'll init the
3313 * secondary cpus' numa_mem as they come on-line. During
3314 * node/memory hotplug, we'll fixup all on-line cpus.
3316 if (cpu_online(cpu
))
3317 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
3325 * Called with zonelists_mutex held always
3326 * unless system_state == SYSTEM_BOOTING.
3328 void __ref
build_all_zonelists(void *data
)
3330 set_zonelist_order();
3332 if (system_state
== SYSTEM_BOOTING
) {
3333 __build_all_zonelists(NULL
);
3334 mminit_verify_zonelist();
3335 cpuset_init_current_mems_allowed();
3337 /* we have to stop all cpus to guarantee there is no user
3339 #ifdef CONFIG_MEMORY_HOTPLUG
3341 setup_zone_pageset((struct zone
*)data
);
3343 stop_machine(__build_all_zonelists
, NULL
, NULL
);
3344 /* cpuset refresh routine should be here */
3346 vm_total_pages
= nr_free_pagecache_pages();
3348 * Disable grouping by mobility if the number of pages in the
3349 * system is too low to allow the mechanism to work. It would be
3350 * more accurate, but expensive to check per-zone. This check is
3351 * made on memory-hotadd so a system can start with mobility
3352 * disabled and enable it later
3354 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
3355 page_group_by_mobility_disabled
= 1;
3357 page_group_by_mobility_disabled
= 0;
3359 printk("Built %i zonelists in %s order, mobility grouping %s. "
3360 "Total pages: %ld\n",
3362 zonelist_order_name
[current_zonelist_order
],
3363 page_group_by_mobility_disabled
? "off" : "on",
3366 printk("Policy zone: %s\n", zone_names
[policy_zone
]);
3371 * Helper functions to size the waitqueue hash table.
3372 * Essentially these want to choose hash table sizes sufficiently
3373 * large so that collisions trying to wait on pages are rare.
3374 * But in fact, the number of active page waitqueues on typical
3375 * systems is ridiculously low, less than 200. So this is even
3376 * conservative, even though it seems large.
3378 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3379 * waitqueues, i.e. the size of the waitq table given the number of pages.
3381 #define PAGES_PER_WAITQUEUE 256
3383 #ifndef CONFIG_MEMORY_HOTPLUG
3384 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3386 unsigned long size
= 1;
3388 pages
/= PAGES_PER_WAITQUEUE
;
3390 while (size
< pages
)
3394 * Once we have dozens or even hundreds of threads sleeping
3395 * on IO we've got bigger problems than wait queue collision.
3396 * Limit the size of the wait table to a reasonable size.
3398 size
= min(size
, 4096UL);
3400 return max(size
, 4UL);
3404 * A zone's size might be changed by hot-add, so it is not possible to determine
3405 * a suitable size for its wait_table. So we use the maximum size now.
3407 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
3409 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
3410 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3411 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
3413 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3414 * or more by the traditional way. (See above). It equals:
3416 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
3417 * ia64(16K page size) : = ( 8G + 4M)byte.
3418 * powerpc (64K page size) : = (32G +16M)byte.
3420 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3427 * This is an integer logarithm so that shifts can be used later
3428 * to extract the more random high bits from the multiplicative
3429 * hash function before the remainder is taken.
3431 static inline unsigned long wait_table_bits(unsigned long size
)
3436 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
3439 * Check if a pageblock contains reserved pages
3441 static int pageblock_is_reserved(unsigned long start_pfn
, unsigned long end_pfn
)
3445 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
3446 if (!pfn_valid_within(pfn
) || PageReserved(pfn_to_page(pfn
)))
3453 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3454 * of blocks reserved is based on min_wmark_pages(zone). The memory within
3455 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3456 * higher will lead to a bigger reserve which will get freed as contiguous
3457 * blocks as reclaim kicks in
3459 static void setup_zone_migrate_reserve(struct zone
*zone
)
3461 unsigned long start_pfn
, pfn
, end_pfn
, block_end_pfn
;
3463 unsigned long block_migratetype
;
3467 * Get the start pfn, end pfn and the number of blocks to reserve
3468 * We have to be careful to be aligned to pageblock_nr_pages to
3469 * make sure that we always check pfn_valid for the first page in
3472 start_pfn
= zone
->zone_start_pfn
;
3473 end_pfn
= start_pfn
+ zone
->spanned_pages
;
3474 start_pfn
= roundup(start_pfn
, pageblock_nr_pages
);
3475 reserve
= roundup(min_wmark_pages(zone
), pageblock_nr_pages
) >>
3479 * Reserve blocks are generally in place to help high-order atomic
3480 * allocations that are short-lived. A min_free_kbytes value that
3481 * would result in more than 2 reserve blocks for atomic allocations
3482 * is assumed to be in place to help anti-fragmentation for the
3483 * future allocation of hugepages at runtime.
3485 reserve
= min(2, reserve
);
3487 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
3488 if (!pfn_valid(pfn
))
3490 page
= pfn_to_page(pfn
);
3492 /* Watch out for overlapping nodes */
3493 if (page_to_nid(page
) != zone_to_nid(zone
))
3496 block_migratetype
= get_pageblock_migratetype(page
);
3498 /* Only test what is necessary when the reserves are not met */
3501 * Blocks with reserved pages will never free, skip
3504 block_end_pfn
= min(pfn
+ pageblock_nr_pages
, end_pfn
);
3505 if (pageblock_is_reserved(pfn
, block_end_pfn
))
3508 /* If this block is reserved, account for it */
3509 if (block_migratetype
== MIGRATE_RESERVE
) {
3514 /* Suitable for reserving if this block is movable */
3515 if (block_migratetype
== MIGRATE_MOVABLE
) {
3516 set_pageblock_migratetype(page
,
3518 move_freepages_block(zone
, page
,
3526 * If the reserve is met and this is a previous reserved block,
3529 if (block_migratetype
== MIGRATE_RESERVE
) {
3530 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3531 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
3537 * Initially all pages are reserved - free ones are freed
3538 * up by free_all_bootmem() once the early boot process is
3539 * done. Non-atomic initialization, single-pass.
3541 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
3542 unsigned long start_pfn
, enum memmap_context context
)
3545 unsigned long end_pfn
= start_pfn
+ size
;
3549 if (highest_memmap_pfn
< end_pfn
- 1)
3550 highest_memmap_pfn
= end_pfn
- 1;
3552 z
= &NODE_DATA(nid
)->node_zones
[zone
];
3553 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
3555 * There can be holes in boot-time mem_map[]s
3556 * handed to this function. They do not
3557 * exist on hotplugged memory.
3559 if (context
== MEMMAP_EARLY
) {
3560 if (!early_pfn_valid(pfn
))
3562 if (!early_pfn_in_nid(pfn
, nid
))
3565 page
= pfn_to_page(pfn
);
3566 set_page_links(page
, zone
, nid
, pfn
);
3567 mminit_verify_page_links(page
, zone
, nid
, pfn
);
3568 init_page_count(page
);
3569 reset_page_mapcount(page
);
3570 SetPageReserved(page
);
3572 * Mark the block movable so that blocks are reserved for
3573 * movable at startup. This will force kernel allocations
3574 * to reserve their blocks rather than leaking throughout
3575 * the address space during boot when many long-lived
3576 * kernel allocations are made. Later some blocks near
3577 * the start are marked MIGRATE_RESERVE by
3578 * setup_zone_migrate_reserve()
3580 * bitmap is created for zone's valid pfn range. but memmap
3581 * can be created for invalid pages (for alignment)
3582 * check here not to call set_pageblock_migratetype() against
3585 if ((z
->zone_start_pfn
<= pfn
)
3586 && (pfn
< z
->zone_start_pfn
+ z
->spanned_pages
)
3587 && !(pfn
& (pageblock_nr_pages
- 1)))
3588 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3590 INIT_LIST_HEAD(&page
->lru
);
3591 #ifdef WANT_PAGE_VIRTUAL
3592 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
3593 if (!is_highmem_idx(zone
))
3594 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
3599 static void __meminit
zone_init_free_lists(struct zone
*zone
)
3602 for_each_migratetype_order(order
, t
) {
3603 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
3604 zone
->free_area
[order
].nr_free
= 0;
3608 #ifndef __HAVE_ARCH_MEMMAP_INIT
3609 #define memmap_init(size, nid, zone, start_pfn) \
3610 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
3613 static int zone_batchsize(struct zone
*zone
)
3619 * The per-cpu-pages pools are set to around 1000th of the
3620 * size of the zone. But no more than 1/2 of a meg.
3622 * OK, so we don't know how big the cache is. So guess.
3624 batch
= zone
->present_pages
/ 1024;
3625 if (batch
* PAGE_SIZE
> 512 * 1024)
3626 batch
= (512 * 1024) / PAGE_SIZE
;
3627 batch
/= 4; /* We effectively *= 4 below */
3632 * Clamp the batch to a 2^n - 1 value. Having a power
3633 * of 2 value was found to be more likely to have
3634 * suboptimal cache aliasing properties in some cases.
3636 * For example if 2 tasks are alternately allocating
3637 * batches of pages, one task can end up with a lot
3638 * of pages of one half of the possible page colors
3639 * and the other with pages of the other colors.
3641 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
3646 /* The deferral and batching of frees should be suppressed under NOMMU
3649 * The problem is that NOMMU needs to be able to allocate large chunks
3650 * of contiguous memory as there's no hardware page translation to
3651 * assemble apparent contiguous memory from discontiguous pages.
3653 * Queueing large contiguous runs of pages for batching, however,
3654 * causes the pages to actually be freed in smaller chunks. As there
3655 * can be a significant delay between the individual batches being
3656 * recycled, this leads to the once large chunks of space being
3657 * fragmented and becoming unavailable for high-order allocations.
3663 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
3665 struct per_cpu_pages
*pcp
;
3668 memset(p
, 0, sizeof(*p
));
3672 pcp
->high
= 6 * batch
;
3673 pcp
->batch
= max(1UL, 1 * batch
);
3674 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
3675 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
3679 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
3680 * to the value high for the pageset p.
3683 static void setup_pagelist_highmark(struct per_cpu_pageset
*p
,
3686 struct per_cpu_pages
*pcp
;
3690 pcp
->batch
= max(1UL, high
/4);
3691 if ((high
/4) > (PAGE_SHIFT
* 8))
3692 pcp
->batch
= PAGE_SHIFT
* 8;
3695 static void setup_zone_pageset(struct zone
*zone
)
3699 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
3701 for_each_possible_cpu(cpu
) {
3702 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
3704 setup_pageset(pcp
, zone_batchsize(zone
));
3706 if (percpu_pagelist_fraction
)
3707 setup_pagelist_highmark(pcp
,
3708 (zone
->present_pages
/
3709 percpu_pagelist_fraction
));
3714 * Allocate per cpu pagesets and initialize them.
3715 * Before this call only boot pagesets were available.
3717 void __init
setup_per_cpu_pageset(void)
3721 for_each_populated_zone(zone
)
3722 setup_zone_pageset(zone
);
3725 static noinline __init_refok
3726 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
3729 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
3733 * The per-page waitqueue mechanism uses hashed waitqueues
3736 zone
->wait_table_hash_nr_entries
=
3737 wait_table_hash_nr_entries(zone_size_pages
);
3738 zone
->wait_table_bits
=
3739 wait_table_bits(zone
->wait_table_hash_nr_entries
);
3740 alloc_size
= zone
->wait_table_hash_nr_entries
3741 * sizeof(wait_queue_head_t
);
3743 if (!slab_is_available()) {
3744 zone
->wait_table
= (wait_queue_head_t
*)
3745 alloc_bootmem_node_nopanic(pgdat
, alloc_size
);
3748 * This case means that a zone whose size was 0 gets new memory
3749 * via memory hot-add.
3750 * But it may be the case that a new node was hot-added. In
3751 * this case vmalloc() will not be able to use this new node's
3752 * memory - this wait_table must be initialized to use this new
3753 * node itself as well.
3754 * To use this new node's memory, further consideration will be
3757 zone
->wait_table
= vmalloc(alloc_size
);
3759 if (!zone
->wait_table
)
3762 for(i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
3763 init_waitqueue_head(zone
->wait_table
+ i
);
3768 static int __zone_pcp_update(void *data
)
3770 struct zone
*zone
= data
;
3772 unsigned long batch
= zone_batchsize(zone
), flags
;
3774 for_each_possible_cpu(cpu
) {
3775 struct per_cpu_pageset
*pset
;
3776 struct per_cpu_pages
*pcp
;
3778 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
3781 local_irq_save(flags
);
3782 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
3783 setup_pageset(pset
, batch
);
3784 local_irq_restore(flags
);
3789 void zone_pcp_update(struct zone
*zone
)
3791 stop_machine(__zone_pcp_update
, zone
, NULL
);
3794 static __meminit
void zone_pcp_init(struct zone
*zone
)
3797 * per cpu subsystem is not up at this point. The following code
3798 * relies on the ability of the linker to provide the
3799 * offset of a (static) per cpu variable into the per cpu area.
3801 zone
->pageset
= &boot_pageset
;
3803 if (zone
->present_pages
)
3804 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
3805 zone
->name
, zone
->present_pages
,
3806 zone_batchsize(zone
));
3809 __meminit
int init_currently_empty_zone(struct zone
*zone
,
3810 unsigned long zone_start_pfn
,
3812 enum memmap_context context
)
3814 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
3816 ret
= zone_wait_table_init(zone
, size
);
3819 pgdat
->nr_zones
= zone_idx(zone
) + 1;
3821 zone
->zone_start_pfn
= zone_start_pfn
;
3823 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
3824 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
3826 (unsigned long)zone_idx(zone
),
3827 zone_start_pfn
, (zone_start_pfn
+ size
));
3829 zone_init_free_lists(zone
);
3834 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
3835 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
3837 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
3838 * Architectures may implement their own version but if add_active_range()
3839 * was used and there are no special requirements, this is a convenient
3842 int __meminit
__early_pfn_to_nid(unsigned long pfn
)
3844 unsigned long start_pfn
, end_pfn
;
3847 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
3848 if (start_pfn
<= pfn
&& pfn
< end_pfn
)
3850 /* This is a memory hole */
3853 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
3855 int __meminit
early_pfn_to_nid(unsigned long pfn
)
3859 nid
= __early_pfn_to_nid(pfn
);
3862 /* just returns 0 */
3866 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
3867 bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
3871 nid
= __early_pfn_to_nid(pfn
);
3872 if (nid
>= 0 && nid
!= node
)
3879 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
3880 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
3881 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
3883 * If an architecture guarantees that all ranges registered with
3884 * add_active_ranges() contain no holes and may be freed, this
3885 * this function may be used instead of calling free_bootmem() manually.
3887 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
3889 unsigned long start_pfn
, end_pfn
;
3892 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
3893 start_pfn
= min(start_pfn
, max_low_pfn
);
3894 end_pfn
= min(end_pfn
, max_low_pfn
);
3896 if (start_pfn
< end_pfn
)
3897 free_bootmem_node(NODE_DATA(this_nid
),
3898 PFN_PHYS(start_pfn
),
3899 (end_pfn
- start_pfn
) << PAGE_SHIFT
);
3903 int __init
add_from_early_node_map(struct range
*range
, int az
,
3904 int nr_range
, int nid
)
3906 unsigned long start_pfn
, end_pfn
;
3909 /* need to go over early_node_map to find out good range for node */
3910 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
)
3911 nr_range
= add_range(range
, az
, nr_range
, start_pfn
, end_pfn
);
3916 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3917 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3919 * If an architecture guarantees that all ranges registered with
3920 * add_active_ranges() contain no holes and may be freed, this
3921 * function may be used instead of calling memory_present() manually.
3923 void __init
sparse_memory_present_with_active_regions(int nid
)
3925 unsigned long start_pfn
, end_pfn
;
3928 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
3929 memory_present(this_nid
, start_pfn
, end_pfn
);
3933 * get_pfn_range_for_nid - Return the start and end page frames for a node
3934 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
3935 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
3936 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
3938 * It returns the start and end page frame of a node based on information
3939 * provided by an arch calling add_active_range(). If called for a node
3940 * with no available memory, a warning is printed and the start and end
3943 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
3944 unsigned long *start_pfn
, unsigned long *end_pfn
)
3946 unsigned long this_start_pfn
, this_end_pfn
;
3952 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
3953 *start_pfn
= min(*start_pfn
, this_start_pfn
);
3954 *end_pfn
= max(*end_pfn
, this_end_pfn
);
3957 if (*start_pfn
== -1UL)
3962 * This finds a zone that can be used for ZONE_MOVABLE pages. The
3963 * assumption is made that zones within a node are ordered in monotonic
3964 * increasing memory addresses so that the "highest" populated zone is used
3966 static void __init
find_usable_zone_for_movable(void)
3969 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
3970 if (zone_index
== ZONE_MOVABLE
)
3973 if (arch_zone_highest_possible_pfn
[zone_index
] >
3974 arch_zone_lowest_possible_pfn
[zone_index
])
3978 VM_BUG_ON(zone_index
== -1);
3979 movable_zone
= zone_index
;
3983 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
3984 * because it is sized independent of architecture. Unlike the other zones,
3985 * the starting point for ZONE_MOVABLE is not fixed. It may be different
3986 * in each node depending on the size of each node and how evenly kernelcore
3987 * is distributed. This helper function adjusts the zone ranges
3988 * provided by the architecture for a given node by using the end of the
3989 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
3990 * zones within a node are in order of monotonic increases memory addresses
3992 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
3993 unsigned long zone_type
,
3994 unsigned long node_start_pfn
,
3995 unsigned long node_end_pfn
,
3996 unsigned long *zone_start_pfn
,
3997 unsigned long *zone_end_pfn
)
3999 /* Only adjust if ZONE_MOVABLE is on this node */
4000 if (zone_movable_pfn
[nid
]) {
4001 /* Size ZONE_MOVABLE */
4002 if (zone_type
== ZONE_MOVABLE
) {
4003 *zone_start_pfn
= zone_movable_pfn
[nid
];
4004 *zone_end_pfn
= min(node_end_pfn
,
4005 arch_zone_highest_possible_pfn
[movable_zone
]);
4007 /* Adjust for ZONE_MOVABLE starting within this range */
4008 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
4009 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
4010 *zone_end_pfn
= zone_movable_pfn
[nid
];
4012 /* Check if this whole range is within ZONE_MOVABLE */
4013 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
4014 *zone_start_pfn
= *zone_end_pfn
;
4019 * Return the number of pages a zone spans in a node, including holes
4020 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4022 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4023 unsigned long zone_type
,
4024 unsigned long *ignored
)
4026 unsigned long node_start_pfn
, node_end_pfn
;
4027 unsigned long zone_start_pfn
, zone_end_pfn
;
4029 /* Get the start and end of the node and zone */
4030 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
4031 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
4032 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
4033 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4034 node_start_pfn
, node_end_pfn
,
4035 &zone_start_pfn
, &zone_end_pfn
);
4037 /* Check that this node has pages within the zone's required range */
4038 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
4041 /* Move the zone boundaries inside the node if necessary */
4042 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
4043 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
4045 /* Return the spanned pages */
4046 return zone_end_pfn
- zone_start_pfn
;
4050 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4051 * then all holes in the requested range will be accounted for.
4053 unsigned long __meminit
__absent_pages_in_range(int nid
,
4054 unsigned long range_start_pfn
,
4055 unsigned long range_end_pfn
)
4057 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
4058 unsigned long start_pfn
, end_pfn
;
4061 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
4062 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
4063 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
4064 nr_absent
-= end_pfn
- start_pfn
;
4070 * absent_pages_in_range - Return number of page frames in holes within a range
4071 * @start_pfn: The start PFN to start searching for holes
4072 * @end_pfn: The end PFN to stop searching for holes
4074 * It returns the number of pages frames in memory holes within a range.
4076 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
4077 unsigned long end_pfn
)
4079 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
4082 /* Return the number of page frames in holes in a zone on a node */
4083 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4084 unsigned long zone_type
,
4085 unsigned long *ignored
)
4087 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
4088 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
4089 unsigned long node_start_pfn
, node_end_pfn
;
4090 unsigned long zone_start_pfn
, zone_end_pfn
;
4092 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
4093 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
4094 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
4096 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4097 node_start_pfn
, node_end_pfn
,
4098 &zone_start_pfn
, &zone_end_pfn
);
4099 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
4102 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4103 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4104 unsigned long zone_type
,
4105 unsigned long *zones_size
)
4107 return zones_size
[zone_type
];
4110 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4111 unsigned long zone_type
,
4112 unsigned long *zholes_size
)
4117 return zholes_size
[zone_type
];
4120 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4122 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
4123 unsigned long *zones_size
, unsigned long *zholes_size
)
4125 unsigned long realtotalpages
, totalpages
= 0;
4128 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4129 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
4131 pgdat
->node_spanned_pages
= totalpages
;
4133 realtotalpages
= totalpages
;
4134 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4136 zone_absent_pages_in_node(pgdat
->node_id
, i
,
4138 pgdat
->node_present_pages
= realtotalpages
;
4139 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
4143 #ifndef CONFIG_SPARSEMEM
4145 * Calculate the size of the zone->blockflags rounded to an unsigned long
4146 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4147 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4148 * round what is now in bits to nearest long in bits, then return it in
4151 static unsigned long __init
usemap_size(unsigned long zonesize
)
4153 unsigned long usemapsize
;
4155 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
4156 usemapsize
= usemapsize
>> pageblock_order
;
4157 usemapsize
*= NR_PAGEBLOCK_BITS
;
4158 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
4160 return usemapsize
/ 8;
4163 static void __init
setup_usemap(struct pglist_data
*pgdat
,
4164 struct zone
*zone
, unsigned long zonesize
)
4166 unsigned long usemapsize
= usemap_size(zonesize
);
4167 zone
->pageblock_flags
= NULL
;
4169 zone
->pageblock_flags
= alloc_bootmem_node_nopanic(pgdat
,
4173 static inline void setup_usemap(struct pglist_data
*pgdat
,
4174 struct zone
*zone
, unsigned long zonesize
) {}
4175 #endif /* CONFIG_SPARSEMEM */
4177 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4179 /* Return a sensible default order for the pageblock size. */
4180 static inline int pageblock_default_order(void)
4182 if (HPAGE_SHIFT
> PAGE_SHIFT
)
4183 return HUGETLB_PAGE_ORDER
;
4188 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4189 static inline void __init
set_pageblock_order(unsigned int order
)
4191 /* Check that pageblock_nr_pages has not already been setup */
4192 if (pageblock_order
)
4196 * Assume the largest contiguous order of interest is a huge page.
4197 * This value may be variable depending on boot parameters on IA64
4199 pageblock_order
= order
;
4201 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4204 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4205 * and pageblock_default_order() are unused as pageblock_order is set
4206 * at compile-time. See include/linux/pageblock-flags.h for the values of
4207 * pageblock_order based on the kernel config
4209 static inline int pageblock_default_order(unsigned int order
)
4213 #define set_pageblock_order(x) do {} while (0)
4215 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4218 * Set up the zone data structures:
4219 * - mark all pages reserved
4220 * - mark all memory queues empty
4221 * - clear the memory bitmaps
4223 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
,
4224 unsigned long *zones_size
, unsigned long *zholes_size
)
4227 int nid
= pgdat
->node_id
;
4228 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
4231 pgdat_resize_init(pgdat
);
4232 pgdat
->nr_zones
= 0;
4233 init_waitqueue_head(&pgdat
->kswapd_wait
);
4234 pgdat
->kswapd_max_order
= 0;
4235 pgdat_page_cgroup_init(pgdat
);
4237 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4238 struct zone
*zone
= pgdat
->node_zones
+ j
;
4239 unsigned long size
, realsize
, memmap_pages
;
4242 size
= zone_spanned_pages_in_node(nid
, j
, zones_size
);
4243 realsize
= size
- zone_absent_pages_in_node(nid
, j
,
4247 * Adjust realsize so that it accounts for how much memory
4248 * is used by this zone for memmap. This affects the watermark
4249 * and per-cpu initialisations
4252 PAGE_ALIGN(size
* sizeof(struct page
)) >> PAGE_SHIFT
;
4253 if (realsize
>= memmap_pages
) {
4254 realsize
-= memmap_pages
;
4257 " %s zone: %lu pages used for memmap\n",
4258 zone_names
[j
], memmap_pages
);
4261 " %s zone: %lu pages exceeds realsize %lu\n",
4262 zone_names
[j
], memmap_pages
, realsize
);
4264 /* Account for reserved pages */
4265 if (j
== 0 && realsize
> dma_reserve
) {
4266 realsize
-= dma_reserve
;
4267 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
4268 zone_names
[0], dma_reserve
);
4271 if (!is_highmem_idx(j
))
4272 nr_kernel_pages
+= realsize
;
4273 nr_all_pages
+= realsize
;
4275 zone
->spanned_pages
= size
;
4276 zone
->present_pages
= realsize
;
4279 zone
->min_unmapped_pages
= (realsize
*sysctl_min_unmapped_ratio
)
4281 zone
->min_slab_pages
= (realsize
* sysctl_min_slab_ratio
) / 100;
4283 zone
->name
= zone_names
[j
];
4284 spin_lock_init(&zone
->lock
);
4285 spin_lock_init(&zone
->lru_lock
);
4286 zone_seqlock_init(zone
);
4287 zone
->zone_pgdat
= pgdat
;
4289 zone_pcp_init(zone
);
4291 INIT_LIST_HEAD(&zone
->lru
[l
].list
);
4292 zone
->reclaim_stat
.recent_rotated
[0] = 0;
4293 zone
->reclaim_stat
.recent_rotated
[1] = 0;
4294 zone
->reclaim_stat
.recent_scanned
[0] = 0;
4295 zone
->reclaim_stat
.recent_scanned
[1] = 0;
4296 zap_zone_vm_stats(zone
);
4301 set_pageblock_order(pageblock_default_order());
4302 setup_usemap(pgdat
, zone
, size
);
4303 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
4304 size
, MEMMAP_EARLY
);
4306 memmap_init(size
, nid
, j
, zone_start_pfn
);
4307 zone_start_pfn
+= size
;
4311 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
4313 /* Skip empty nodes */
4314 if (!pgdat
->node_spanned_pages
)
4317 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4318 /* ia64 gets its own node_mem_map, before this, without bootmem */
4319 if (!pgdat
->node_mem_map
) {
4320 unsigned long size
, start
, end
;
4324 * The zone's endpoints aren't required to be MAX_ORDER
4325 * aligned but the node_mem_map endpoints must be in order
4326 * for the buddy allocator to function correctly.
4328 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
4329 end
= pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
4330 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
4331 size
= (end
- start
) * sizeof(struct page
);
4332 map
= alloc_remap(pgdat
->node_id
, size
);
4334 map
= alloc_bootmem_node_nopanic(pgdat
, size
);
4335 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
4337 #ifndef CONFIG_NEED_MULTIPLE_NODES
4339 * With no DISCONTIG, the global mem_map is just set as node 0's
4341 if (pgdat
== NODE_DATA(0)) {
4342 mem_map
= NODE_DATA(0)->node_mem_map
;
4343 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4344 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
4345 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
4346 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4349 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4352 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
4353 unsigned long node_start_pfn
, unsigned long *zholes_size
)
4355 pg_data_t
*pgdat
= NODE_DATA(nid
);
4357 pgdat
->node_id
= nid
;
4358 pgdat
->node_start_pfn
= node_start_pfn
;
4359 calculate_node_totalpages(pgdat
, zones_size
, zholes_size
);
4361 alloc_node_mem_map(pgdat
);
4362 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4363 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
4364 nid
, (unsigned long)pgdat
,
4365 (unsigned long)pgdat
->node_mem_map
);
4368 free_area_init_core(pgdat
, zones_size
, zholes_size
);
4371 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4373 #if MAX_NUMNODES > 1
4375 * Figure out the number of possible node ids.
4377 static void __init
setup_nr_node_ids(void)
4380 unsigned int highest
= 0;
4382 for_each_node_mask(node
, node_possible_map
)
4384 nr_node_ids
= highest
+ 1;
4387 static inline void setup_nr_node_ids(void)
4393 * node_map_pfn_alignment - determine the maximum internode alignment
4395 * This function should be called after node map is populated and sorted.
4396 * It calculates the maximum power of two alignment which can distinguish
4399 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
4400 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
4401 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
4402 * shifted, 1GiB is enough and this function will indicate so.
4404 * This is used to test whether pfn -> nid mapping of the chosen memory
4405 * model has fine enough granularity to avoid incorrect mapping for the
4406 * populated node map.
4408 * Returns the determined alignment in pfn's. 0 if there is no alignment
4409 * requirement (single node).
4411 unsigned long __init
node_map_pfn_alignment(void)
4413 unsigned long accl_mask
= 0, last_end
= 0;
4414 unsigned long start
, end
, mask
;
4418 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
4419 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
4426 * Start with a mask granular enough to pin-point to the
4427 * start pfn and tick off bits one-by-one until it becomes
4428 * too coarse to separate the current node from the last.
4430 mask
= ~((1 << __ffs(start
)) - 1);
4431 while (mask
&& last_end
<= (start
& (mask
<< 1)))
4434 /* accumulate all internode masks */
4438 /* convert mask to number of pages */
4439 return ~accl_mask
+ 1;
4442 /* Find the lowest pfn for a node */
4443 static unsigned long __init
find_min_pfn_for_node(int nid
)
4445 unsigned long min_pfn
= ULONG_MAX
;
4446 unsigned long start_pfn
;
4449 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
4450 min_pfn
= min(min_pfn
, start_pfn
);
4452 if (min_pfn
== ULONG_MAX
) {
4454 "Could not find start_pfn for node %d\n", nid
);
4462 * find_min_pfn_with_active_regions - Find the minimum PFN registered
4464 * It returns the minimum PFN based on information provided via
4465 * add_active_range().
4467 unsigned long __init
find_min_pfn_with_active_regions(void)
4469 return find_min_pfn_for_node(MAX_NUMNODES
);
4473 * early_calculate_totalpages()
4474 * Sum pages in active regions for movable zone.
4475 * Populate N_HIGH_MEMORY for calculating usable_nodes.
4477 static unsigned long __init
early_calculate_totalpages(void)
4479 unsigned long totalpages
= 0;
4480 unsigned long start_pfn
, end_pfn
;
4483 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
4484 unsigned long pages
= end_pfn
- start_pfn
;
4486 totalpages
+= pages
;
4488 node_set_state(nid
, N_HIGH_MEMORY
);
4494 * Find the PFN the Movable zone begins in each node. Kernel memory
4495 * is spread evenly between nodes as long as the nodes have enough
4496 * memory. When they don't, some nodes will have more kernelcore than
4499 static void __init
find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn
)
4502 unsigned long usable_startpfn
;
4503 unsigned long kernelcore_node
, kernelcore_remaining
;
4504 /* save the state before borrow the nodemask */
4505 nodemask_t saved_node_state
= node_states
[N_HIGH_MEMORY
];
4506 unsigned long totalpages
= early_calculate_totalpages();
4507 int usable_nodes
= nodes_weight(node_states
[N_HIGH_MEMORY
]);
4510 * If movablecore was specified, calculate what size of
4511 * kernelcore that corresponds so that memory usable for
4512 * any allocation type is evenly spread. If both kernelcore
4513 * and movablecore are specified, then the value of kernelcore
4514 * will be used for required_kernelcore if it's greater than
4515 * what movablecore would have allowed.
4517 if (required_movablecore
) {
4518 unsigned long corepages
;
4521 * Round-up so that ZONE_MOVABLE is at least as large as what
4522 * was requested by the user
4524 required_movablecore
=
4525 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
4526 corepages
= totalpages
- required_movablecore
;
4528 required_kernelcore
= max(required_kernelcore
, corepages
);
4531 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
4532 if (!required_kernelcore
)
4535 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
4536 find_usable_zone_for_movable();
4537 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
4540 /* Spread kernelcore memory as evenly as possible throughout nodes */
4541 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4542 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4543 unsigned long start_pfn
, end_pfn
;
4546 * Recalculate kernelcore_node if the division per node
4547 * now exceeds what is necessary to satisfy the requested
4548 * amount of memory for the kernel
4550 if (required_kernelcore
< kernelcore_node
)
4551 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4554 * As the map is walked, we track how much memory is usable
4555 * by the kernel using kernelcore_remaining. When it is
4556 * 0, the rest of the node is usable by ZONE_MOVABLE
4558 kernelcore_remaining
= kernelcore_node
;
4560 /* Go through each range of PFNs within this node */
4561 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
4562 unsigned long size_pages
;
4564 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
4565 if (start_pfn
>= end_pfn
)
4568 /* Account for what is only usable for kernelcore */
4569 if (start_pfn
< usable_startpfn
) {
4570 unsigned long kernel_pages
;
4571 kernel_pages
= min(end_pfn
, usable_startpfn
)
4574 kernelcore_remaining
-= min(kernel_pages
,
4575 kernelcore_remaining
);
4576 required_kernelcore
-= min(kernel_pages
,
4577 required_kernelcore
);
4579 /* Continue if range is now fully accounted */
4580 if (end_pfn
<= usable_startpfn
) {
4583 * Push zone_movable_pfn to the end so
4584 * that if we have to rebalance
4585 * kernelcore across nodes, we will
4586 * not double account here
4588 zone_movable_pfn
[nid
] = end_pfn
;
4591 start_pfn
= usable_startpfn
;
4595 * The usable PFN range for ZONE_MOVABLE is from
4596 * start_pfn->end_pfn. Calculate size_pages as the
4597 * number of pages used as kernelcore
4599 size_pages
= end_pfn
- start_pfn
;
4600 if (size_pages
> kernelcore_remaining
)
4601 size_pages
= kernelcore_remaining
;
4602 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
4605 * Some kernelcore has been met, update counts and
4606 * break if the kernelcore for this node has been
4609 required_kernelcore
-= min(required_kernelcore
,
4611 kernelcore_remaining
-= size_pages
;
4612 if (!kernelcore_remaining
)
4618 * If there is still required_kernelcore, we do another pass with one
4619 * less node in the count. This will push zone_movable_pfn[nid] further
4620 * along on the nodes that still have memory until kernelcore is
4624 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
4627 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
4628 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
4629 zone_movable_pfn
[nid
] =
4630 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
4633 /* restore the node_state */
4634 node_states
[N_HIGH_MEMORY
] = saved_node_state
;
4637 /* Any regular memory on that node ? */
4638 static void check_for_regular_memory(pg_data_t
*pgdat
)
4640 #ifdef CONFIG_HIGHMEM
4641 enum zone_type zone_type
;
4643 for (zone_type
= 0; zone_type
<= ZONE_NORMAL
; zone_type
++) {
4644 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4645 if (zone
->present_pages
)
4646 node_set_state(zone_to_nid(zone
), N_NORMAL_MEMORY
);
4652 * free_area_init_nodes - Initialise all pg_data_t and zone data
4653 * @max_zone_pfn: an array of max PFNs for each zone
4655 * This will call free_area_init_node() for each active node in the system.
4656 * Using the page ranges provided by add_active_range(), the size of each
4657 * zone in each node and their holes is calculated. If the maximum PFN
4658 * between two adjacent zones match, it is assumed that the zone is empty.
4659 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
4660 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
4661 * starts where the previous one ended. For example, ZONE_DMA32 starts
4662 * at arch_max_dma_pfn.
4664 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
4666 unsigned long start_pfn
, end_pfn
;
4669 /* Record where the zone boundaries are */
4670 memset(arch_zone_lowest_possible_pfn
, 0,
4671 sizeof(arch_zone_lowest_possible_pfn
));
4672 memset(arch_zone_highest_possible_pfn
, 0,
4673 sizeof(arch_zone_highest_possible_pfn
));
4674 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
4675 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
4676 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
4677 if (i
== ZONE_MOVABLE
)
4679 arch_zone_lowest_possible_pfn
[i
] =
4680 arch_zone_highest_possible_pfn
[i
-1];
4681 arch_zone_highest_possible_pfn
[i
] =
4682 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
4684 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
4685 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
4687 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
4688 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
4689 find_zone_movable_pfns_for_nodes(zone_movable_pfn
);
4691 /* Print out the zone ranges */
4692 printk("Zone PFN ranges:\n");
4693 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4694 if (i
== ZONE_MOVABLE
)
4696 printk(" %-8s ", zone_names
[i
]);
4697 if (arch_zone_lowest_possible_pfn
[i
] ==
4698 arch_zone_highest_possible_pfn
[i
])
4701 printk("%0#10lx -> %0#10lx\n",
4702 arch_zone_lowest_possible_pfn
[i
],
4703 arch_zone_highest_possible_pfn
[i
]);
4706 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
4707 printk("Movable zone start PFN for each node\n");
4708 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
4709 if (zone_movable_pfn
[i
])
4710 printk(" Node %d: %lu\n", i
, zone_movable_pfn
[i
]);
4713 /* Print out the early_node_map[] */
4714 printk("Early memory PFN ranges\n");
4715 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
4716 printk(" %3d: %0#10lx -> %0#10lx\n", nid
, start_pfn
, end_pfn
);
4718 /* Initialise every node */
4719 mminit_verify_pageflags_layout();
4720 setup_nr_node_ids();
4721 for_each_online_node(nid
) {
4722 pg_data_t
*pgdat
= NODE_DATA(nid
);
4723 free_area_init_node(nid
, NULL
,
4724 find_min_pfn_for_node(nid
), NULL
);
4726 /* Any memory on that node */
4727 if (pgdat
->node_present_pages
)
4728 node_set_state(nid
, N_HIGH_MEMORY
);
4729 check_for_regular_memory(pgdat
);
4733 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
4735 unsigned long long coremem
;
4739 coremem
= memparse(p
, &p
);
4740 *core
= coremem
>> PAGE_SHIFT
;
4742 /* Paranoid check that UL is enough for the coremem value */
4743 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
4749 * kernelcore=size sets the amount of memory for use for allocations that
4750 * cannot be reclaimed or migrated.
4752 static int __init
cmdline_parse_kernelcore(char *p
)
4754 return cmdline_parse_core(p
, &required_kernelcore
);
4758 * movablecore=size sets the amount of memory for use for allocations that
4759 * can be reclaimed or migrated.
4761 static int __init
cmdline_parse_movablecore(char *p
)
4763 return cmdline_parse_core(p
, &required_movablecore
);
4766 early_param("kernelcore", cmdline_parse_kernelcore
);
4767 early_param("movablecore", cmdline_parse_movablecore
);
4769 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4772 * set_dma_reserve - set the specified number of pages reserved in the first zone
4773 * @new_dma_reserve: The number of pages to mark reserved
4775 * The per-cpu batchsize and zone watermarks are determined by present_pages.
4776 * In the DMA zone, a significant percentage may be consumed by kernel image
4777 * and other unfreeable allocations which can skew the watermarks badly. This
4778 * function may optionally be used to account for unfreeable pages in the
4779 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
4780 * smaller per-cpu batchsize.
4782 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
4784 dma_reserve
= new_dma_reserve
;
4787 void __init
free_area_init(unsigned long *zones_size
)
4789 free_area_init_node(0, zones_size
,
4790 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
4793 static int page_alloc_cpu_notify(struct notifier_block
*self
,
4794 unsigned long action
, void *hcpu
)
4796 int cpu
= (unsigned long)hcpu
;
4798 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
4802 * Spill the event counters of the dead processor
4803 * into the current processors event counters.
4804 * This artificially elevates the count of the current
4807 vm_events_fold_cpu(cpu
);
4810 * Zero the differential counters of the dead processor
4811 * so that the vm statistics are consistent.
4813 * This is only okay since the processor is dead and cannot
4814 * race with what we are doing.
4816 refresh_cpu_vm_stats(cpu
);
4821 void __init
page_alloc_init(void)
4823 hotcpu_notifier(page_alloc_cpu_notify
, 0);
4827 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
4828 * or min_free_kbytes changes.
4830 static void calculate_totalreserve_pages(void)
4832 struct pglist_data
*pgdat
;
4833 unsigned long reserve_pages
= 0;
4834 enum zone_type i
, j
;
4836 for_each_online_pgdat(pgdat
) {
4837 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4838 struct zone
*zone
= pgdat
->node_zones
+ i
;
4839 unsigned long max
= 0;
4841 /* Find valid and maximum lowmem_reserve in the zone */
4842 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
4843 if (zone
->lowmem_reserve
[j
] > max
)
4844 max
= zone
->lowmem_reserve
[j
];
4847 /* we treat the high watermark as reserved pages. */
4848 max
+= high_wmark_pages(zone
);
4850 if (max
> zone
->present_pages
)
4851 max
= zone
->present_pages
;
4852 reserve_pages
+= max
;
4854 * Lowmem reserves are not available to
4855 * GFP_HIGHUSER page cache allocations and
4856 * kswapd tries to balance zones to their high
4857 * watermark. As a result, neither should be
4858 * regarded as dirtyable memory, to prevent a
4859 * situation where reclaim has to clean pages
4860 * in order to balance the zones.
4862 zone
->dirty_balance_reserve
= max
;
4865 dirty_balance_reserve
= reserve_pages
;
4866 totalreserve_pages
= reserve_pages
;
4870 * setup_per_zone_lowmem_reserve - called whenever
4871 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
4872 * has a correct pages reserved value, so an adequate number of
4873 * pages are left in the zone after a successful __alloc_pages().
4875 static void setup_per_zone_lowmem_reserve(void)
4877 struct pglist_data
*pgdat
;
4878 enum zone_type j
, idx
;
4880 for_each_online_pgdat(pgdat
) {
4881 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4882 struct zone
*zone
= pgdat
->node_zones
+ j
;
4883 unsigned long present_pages
= zone
->present_pages
;
4885 zone
->lowmem_reserve
[j
] = 0;
4889 struct zone
*lower_zone
;
4893 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
4894 sysctl_lowmem_reserve_ratio
[idx
] = 1;
4896 lower_zone
= pgdat
->node_zones
+ idx
;
4897 lower_zone
->lowmem_reserve
[j
] = present_pages
/
4898 sysctl_lowmem_reserve_ratio
[idx
];
4899 present_pages
+= lower_zone
->present_pages
;
4904 /* update totalreserve_pages */
4905 calculate_totalreserve_pages();
4909 * setup_per_zone_wmarks - called when min_free_kbytes changes
4910 * or when memory is hot-{added|removed}
4912 * Ensures that the watermark[min,low,high] values for each zone are set
4913 * correctly with respect to min_free_kbytes.
4915 void setup_per_zone_wmarks(void)
4917 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
4918 unsigned long lowmem_pages
= 0;
4920 unsigned long flags
;
4922 /* Calculate total number of !ZONE_HIGHMEM pages */
4923 for_each_zone(zone
) {
4924 if (!is_highmem(zone
))
4925 lowmem_pages
+= zone
->present_pages
;
4928 for_each_zone(zone
) {
4931 spin_lock_irqsave(&zone
->lock
, flags
);
4932 tmp
= (u64
)pages_min
* zone
->present_pages
;
4933 do_div(tmp
, lowmem_pages
);
4934 if (is_highmem(zone
)) {
4936 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
4937 * need highmem pages, so cap pages_min to a small
4940 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
4941 * deltas controls asynch page reclaim, and so should
4942 * not be capped for highmem.
4946 min_pages
= zone
->present_pages
/ 1024;
4947 if (min_pages
< SWAP_CLUSTER_MAX
)
4948 min_pages
= SWAP_CLUSTER_MAX
;
4949 if (min_pages
> 128)
4951 zone
->watermark
[WMARK_MIN
] = min_pages
;
4954 * If it's a lowmem zone, reserve a number of pages
4955 * proportionate to the zone's size.
4957 zone
->watermark
[WMARK_MIN
] = tmp
;
4960 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + (tmp
>> 2);
4961 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + (tmp
>> 1);
4962 setup_zone_migrate_reserve(zone
);
4963 spin_unlock_irqrestore(&zone
->lock
, flags
);
4966 /* update totalreserve_pages */
4967 calculate_totalreserve_pages();
4971 * The inactive anon list should be small enough that the VM never has to
4972 * do too much work, but large enough that each inactive page has a chance
4973 * to be referenced again before it is swapped out.
4975 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
4976 * INACTIVE_ANON pages on this zone's LRU, maintained by the
4977 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
4978 * the anonymous pages are kept on the inactive list.
4981 * memory ratio inactive anon
4982 * -------------------------------------
4991 static void __meminit
calculate_zone_inactive_ratio(struct zone
*zone
)
4993 unsigned int gb
, ratio
;
4995 /* Zone size in gigabytes */
4996 gb
= zone
->present_pages
>> (30 - PAGE_SHIFT
);
4998 ratio
= int_sqrt(10 * gb
);
5002 zone
->inactive_ratio
= ratio
;
5005 static void __meminit
setup_per_zone_inactive_ratio(void)
5010 calculate_zone_inactive_ratio(zone
);
5014 * Initialise min_free_kbytes.
5016 * For small machines we want it small (128k min). For large machines
5017 * we want it large (64MB max). But it is not linear, because network
5018 * bandwidth does not increase linearly with machine size. We use
5020 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5021 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
5037 int __meminit
init_per_zone_wmark_min(void)
5039 unsigned long lowmem_kbytes
;
5041 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
5043 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
5044 if (min_free_kbytes
< 128)
5045 min_free_kbytes
= 128;
5046 if (min_free_kbytes
> 65536)
5047 min_free_kbytes
= 65536;
5048 setup_per_zone_wmarks();
5049 refresh_zone_stat_thresholds();
5050 setup_per_zone_lowmem_reserve();
5051 setup_per_zone_inactive_ratio();
5054 module_init(init_per_zone_wmark_min
)
5057 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5058 * that we can call two helper functions whenever min_free_kbytes
5061 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
5062 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5064 proc_dointvec(table
, write
, buffer
, length
, ppos
);
5066 setup_per_zone_wmarks();
5071 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
5072 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5077 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5082 zone
->min_unmapped_pages
= (zone
->present_pages
*
5083 sysctl_min_unmapped_ratio
) / 100;
5087 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
5088 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5093 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5098 zone
->min_slab_pages
= (zone
->present_pages
*
5099 sysctl_min_slab_ratio
) / 100;
5105 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5106 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5107 * whenever sysctl_lowmem_reserve_ratio changes.
5109 * The reserve ratio obviously has absolutely no relation with the
5110 * minimum watermarks. The lowmem reserve ratio can only make sense
5111 * if in function of the boot time zone sizes.
5113 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
5114 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5116 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5117 setup_per_zone_lowmem_reserve();
5122 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5123 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
5124 * can have before it gets flushed back to buddy allocator.
5127 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
5128 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5134 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5135 if (!write
|| (ret
== -EINVAL
))
5137 for_each_populated_zone(zone
) {
5138 for_each_possible_cpu(cpu
) {
5140 high
= zone
->present_pages
/ percpu_pagelist_fraction
;
5141 setup_pagelist_highmark(
5142 per_cpu_ptr(zone
->pageset
, cpu
), high
);
5148 int hashdist
= HASHDIST_DEFAULT
;
5151 static int __init
set_hashdist(char *str
)
5155 hashdist
= simple_strtoul(str
, &str
, 0);
5158 __setup("hashdist=", set_hashdist
);
5162 * allocate a large system hash table from bootmem
5163 * - it is assumed that the hash table must contain an exact power-of-2
5164 * quantity of entries
5165 * - limit is the number of hash buckets, not the total allocation size
5167 void *__init
alloc_large_system_hash(const char *tablename
,
5168 unsigned long bucketsize
,
5169 unsigned long numentries
,
5172 unsigned int *_hash_shift
,
5173 unsigned int *_hash_mask
,
5174 unsigned long limit
)
5176 unsigned long long max
= limit
;
5177 unsigned long log2qty
, size
;
5180 /* allow the kernel cmdline to have a say */
5182 /* round applicable memory size up to nearest megabyte */
5183 numentries
= nr_kernel_pages
;
5184 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
5185 numentries
>>= 20 - PAGE_SHIFT
;
5186 numentries
<<= 20 - PAGE_SHIFT
;
5188 /* limit to 1 bucket per 2^scale bytes of low memory */
5189 if (scale
> PAGE_SHIFT
)
5190 numentries
>>= (scale
- PAGE_SHIFT
);
5192 numentries
<<= (PAGE_SHIFT
- scale
);
5194 /* Make sure we've got at least a 0-order allocation.. */
5195 if (unlikely(flags
& HASH_SMALL
)) {
5196 /* Makes no sense without HASH_EARLY */
5197 WARN_ON(!(flags
& HASH_EARLY
));
5198 if (!(numentries
>> *_hash_shift
)) {
5199 numentries
= 1UL << *_hash_shift
;
5200 BUG_ON(!numentries
);
5202 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
5203 numentries
= PAGE_SIZE
/ bucketsize
;
5205 numentries
= roundup_pow_of_two(numentries
);
5207 /* limit allocation size to 1/16 total memory by default */
5209 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
5210 do_div(max
, bucketsize
);
5213 if (numentries
> max
)
5216 log2qty
= ilog2(numentries
);
5219 size
= bucketsize
<< log2qty
;
5220 if (flags
& HASH_EARLY
)
5221 table
= alloc_bootmem_nopanic(size
);
5223 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
5226 * If bucketsize is not a power-of-two, we may free
5227 * some pages at the end of hash table which
5228 * alloc_pages_exact() automatically does
5230 if (get_order(size
) < MAX_ORDER
) {
5231 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
5232 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
5235 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
5238 panic("Failed to allocate %s hash table\n", tablename
);
5240 printk(KERN_INFO
"%s hash table entries: %ld (order: %d, %lu bytes)\n",
5243 ilog2(size
) - PAGE_SHIFT
,
5247 *_hash_shift
= log2qty
;
5249 *_hash_mask
= (1 << log2qty
) - 1;
5254 /* Return a pointer to the bitmap storing bits affecting a block of pages */
5255 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
5258 #ifdef CONFIG_SPARSEMEM
5259 return __pfn_to_section(pfn
)->pageblock_flags
;
5261 return zone
->pageblock_flags
;
5262 #endif /* CONFIG_SPARSEMEM */
5265 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
5267 #ifdef CONFIG_SPARSEMEM
5268 pfn
&= (PAGES_PER_SECTION
-1);
5269 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5271 pfn
= pfn
- zone
->zone_start_pfn
;
5272 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5273 #endif /* CONFIG_SPARSEMEM */
5277 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5278 * @page: The page within the block of interest
5279 * @start_bitidx: The first bit of interest to retrieve
5280 * @end_bitidx: The last bit of interest
5281 * returns pageblock_bits flags
5283 unsigned long get_pageblock_flags_group(struct page
*page
,
5284 int start_bitidx
, int end_bitidx
)
5287 unsigned long *bitmap
;
5288 unsigned long pfn
, bitidx
;
5289 unsigned long flags
= 0;
5290 unsigned long value
= 1;
5292 zone
= page_zone(page
);
5293 pfn
= page_to_pfn(page
);
5294 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5295 bitidx
= pfn_to_bitidx(zone
, pfn
);
5297 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5298 if (test_bit(bitidx
+ start_bitidx
, bitmap
))
5305 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5306 * @page: The page within the block of interest
5307 * @start_bitidx: The first bit of interest
5308 * @end_bitidx: The last bit of interest
5309 * @flags: The flags to set
5311 void set_pageblock_flags_group(struct page
*page
, unsigned long flags
,
5312 int start_bitidx
, int end_bitidx
)
5315 unsigned long *bitmap
;
5316 unsigned long pfn
, bitidx
;
5317 unsigned long value
= 1;
5319 zone
= page_zone(page
);
5320 pfn
= page_to_pfn(page
);
5321 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5322 bitidx
= pfn_to_bitidx(zone
, pfn
);
5323 VM_BUG_ON(pfn
< zone
->zone_start_pfn
);
5324 VM_BUG_ON(pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
);
5326 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5328 __set_bit(bitidx
+ start_bitidx
, bitmap
);
5330 __clear_bit(bitidx
+ start_bitidx
, bitmap
);
5334 * This is designed as sub function...plz see page_isolation.c also.
5335 * set/clear page block's type to be ISOLATE.
5336 * page allocater never alloc memory from ISOLATE block.
5340 __count_immobile_pages(struct zone
*zone
, struct page
*page
, int count
)
5342 unsigned long pfn
, iter
, found
;
5344 * For avoiding noise data, lru_add_drain_all() should be called
5345 * If ZONE_MOVABLE, the zone never contains immobile pages
5347 if (zone_idx(zone
) == ZONE_MOVABLE
)
5350 if (get_pageblock_migratetype(page
) == MIGRATE_MOVABLE
)
5353 pfn
= page_to_pfn(page
);
5354 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
5355 unsigned long check
= pfn
+ iter
;
5357 if (!pfn_valid_within(check
))
5360 page
= pfn_to_page(check
);
5361 if (!page_count(page
)) {
5362 if (PageBuddy(page
))
5363 iter
+= (1 << page_order(page
)) - 1;
5369 * If there are RECLAIMABLE pages, we need to check it.
5370 * But now, memory offline itself doesn't call shrink_slab()
5371 * and it still to be fixed.
5374 * If the page is not RAM, page_count()should be 0.
5375 * we don't need more check. This is an _used_ not-movable page.
5377 * The problematic thing here is PG_reserved pages. PG_reserved
5378 * is set to both of a memory hole page and a _used_ kernel
5387 bool is_pageblock_removable_nolock(struct page
*page
)
5389 struct zone
*zone
= page_zone(page
);
5390 return __count_immobile_pages(zone
, page
, 0);
5393 int set_migratetype_isolate(struct page
*page
)
5396 unsigned long flags
, pfn
;
5397 struct memory_isolate_notify arg
;
5401 zone
= page_zone(page
);
5403 spin_lock_irqsave(&zone
->lock
, flags
);
5405 pfn
= page_to_pfn(page
);
5406 arg
.start_pfn
= pfn
;
5407 arg
.nr_pages
= pageblock_nr_pages
;
5408 arg
.pages_found
= 0;
5411 * It may be possible to isolate a pageblock even if the
5412 * migratetype is not MIGRATE_MOVABLE. The memory isolation
5413 * notifier chain is used by balloon drivers to return the
5414 * number of pages in a range that are held by the balloon
5415 * driver to shrink memory. If all the pages are accounted for
5416 * by balloons, are free, or on the LRU, isolation can continue.
5417 * Later, for example, when memory hotplug notifier runs, these
5418 * pages reported as "can be isolated" should be isolated(freed)
5419 * by the balloon driver through the memory notifier chain.
5421 notifier_ret
= memory_isolate_notify(MEM_ISOLATE_COUNT
, &arg
);
5422 notifier_ret
= notifier_to_errno(notifier_ret
);
5426 * FIXME: Now, memory hotplug doesn't call shrink_slab() by itself.
5427 * We just check MOVABLE pages.
5429 if (__count_immobile_pages(zone
, page
, arg
.pages_found
))
5433 * immobile means "not-on-lru" paes. If immobile is larger than
5434 * removable-by-driver pages reported by notifier, we'll fail.
5439 set_pageblock_migratetype(page
, MIGRATE_ISOLATE
);
5440 move_freepages_block(zone
, page
, MIGRATE_ISOLATE
);
5443 spin_unlock_irqrestore(&zone
->lock
, flags
);
5449 void unset_migratetype_isolate(struct page
*page
)
5452 unsigned long flags
;
5453 zone
= page_zone(page
);
5454 spin_lock_irqsave(&zone
->lock
, flags
);
5455 if (get_pageblock_migratetype(page
) != MIGRATE_ISOLATE
)
5457 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
5458 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
5460 spin_unlock_irqrestore(&zone
->lock
, flags
);
5463 #ifdef CONFIG_MEMORY_HOTREMOVE
5465 * All pages in the range must be isolated before calling this.
5468 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
5474 unsigned long flags
;
5475 /* find the first valid pfn */
5476 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
5481 zone
= page_zone(pfn_to_page(pfn
));
5482 spin_lock_irqsave(&zone
->lock
, flags
);
5484 while (pfn
< end_pfn
) {
5485 if (!pfn_valid(pfn
)) {
5489 page
= pfn_to_page(pfn
);
5490 BUG_ON(page_count(page
));
5491 BUG_ON(!PageBuddy(page
));
5492 order
= page_order(page
);
5493 #ifdef CONFIG_DEBUG_VM
5494 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
5495 pfn
, 1 << order
, end_pfn
);
5497 list_del(&page
->lru
);
5498 rmv_page_order(page
);
5499 zone
->free_area
[order
].nr_free
--;
5500 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
5502 for (i
= 0; i
< (1 << order
); i
++)
5503 SetPageReserved((page
+i
));
5504 pfn
+= (1 << order
);
5506 spin_unlock_irqrestore(&zone
->lock
, flags
);
5510 #ifdef CONFIG_MEMORY_FAILURE
5511 bool is_free_buddy_page(struct page
*page
)
5513 struct zone
*zone
= page_zone(page
);
5514 unsigned long pfn
= page_to_pfn(page
);
5515 unsigned long flags
;
5518 spin_lock_irqsave(&zone
->lock
, flags
);
5519 for (order
= 0; order
< MAX_ORDER
; order
++) {
5520 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
5522 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
5525 spin_unlock_irqrestore(&zone
->lock
, flags
);
5527 return order
< MAX_ORDER
;
5531 static struct trace_print_flags pageflag_names
[] = {
5532 {1UL << PG_locked
, "locked" },
5533 {1UL << PG_error
, "error" },
5534 {1UL << PG_referenced
, "referenced" },
5535 {1UL << PG_uptodate
, "uptodate" },
5536 {1UL << PG_dirty
, "dirty" },
5537 {1UL << PG_lru
, "lru" },
5538 {1UL << PG_active
, "active" },
5539 {1UL << PG_slab
, "slab" },
5540 {1UL << PG_owner_priv_1
, "owner_priv_1" },
5541 {1UL << PG_arch_1
, "arch_1" },
5542 {1UL << PG_reserved
, "reserved" },
5543 {1UL << PG_private
, "private" },
5544 {1UL << PG_private_2
, "private_2" },
5545 {1UL << PG_writeback
, "writeback" },
5546 #ifdef CONFIG_PAGEFLAGS_EXTENDED
5547 {1UL << PG_head
, "head" },
5548 {1UL << PG_tail
, "tail" },
5550 {1UL << PG_compound
, "compound" },
5552 {1UL << PG_swapcache
, "swapcache" },
5553 {1UL << PG_mappedtodisk
, "mappedtodisk" },
5554 {1UL << PG_reclaim
, "reclaim" },
5555 {1UL << PG_swapbacked
, "swapbacked" },
5556 {1UL << PG_unevictable
, "unevictable" },
5558 {1UL << PG_mlocked
, "mlocked" },
5560 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
5561 {1UL << PG_uncached
, "uncached" },
5563 #ifdef CONFIG_MEMORY_FAILURE
5564 {1UL << PG_hwpoison
, "hwpoison" },
5569 static void dump_page_flags(unsigned long flags
)
5571 const char *delim
= "";
5575 printk(KERN_ALERT
"page flags: %#lx(", flags
);
5577 /* remove zone id */
5578 flags
&= (1UL << NR_PAGEFLAGS
) - 1;
5580 for (i
= 0; pageflag_names
[i
].name
&& flags
; i
++) {
5582 mask
= pageflag_names
[i
].mask
;
5583 if ((flags
& mask
) != mask
)
5587 printk("%s%s", delim
, pageflag_names
[i
].name
);
5591 /* check for left over flags */
5593 printk("%s%#lx", delim
, flags
);
5598 void dump_page(struct page
*page
)
5601 "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
5602 page
, atomic_read(&page
->_count
), page_mapcount(page
),
5603 page
->mapping
, page
->index
);
5604 dump_page_flags(page
->flags
);
5605 mem_cgroup_print_bad_page(page
);