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
;
100 int percpu_pagelist_fraction
;
101 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
103 #ifdef CONFIG_PM_SLEEP
105 * The following functions are used by the suspend/hibernate code to temporarily
106 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
107 * while devices are suspended. To avoid races with the suspend/hibernate code,
108 * they should always be called with pm_mutex held (gfp_allowed_mask also should
109 * only be modified with pm_mutex held, unless the suspend/hibernate code is
110 * guaranteed not to run in parallel with that modification).
113 static gfp_t saved_gfp_mask
;
115 void pm_restore_gfp_mask(void)
117 WARN_ON(!mutex_is_locked(&pm_mutex
));
118 if (saved_gfp_mask
) {
119 gfp_allowed_mask
= saved_gfp_mask
;
124 void pm_restrict_gfp_mask(void)
126 WARN_ON(!mutex_is_locked(&pm_mutex
));
127 WARN_ON(saved_gfp_mask
);
128 saved_gfp_mask
= gfp_allowed_mask
;
129 gfp_allowed_mask
&= ~GFP_IOFS
;
132 bool pm_suspended_storage(void)
134 if ((gfp_allowed_mask
& GFP_IOFS
) == GFP_IOFS
)
138 #endif /* CONFIG_PM_SLEEP */
140 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
141 int pageblock_order __read_mostly
;
144 static void __free_pages_ok(struct page
*page
, unsigned int order
);
147 * results with 256, 32 in the lowmem_reserve sysctl:
148 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
149 * 1G machine -> (16M dma, 784M normal, 224M high)
150 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
151 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
152 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
154 * TBD: should special case ZONE_DMA32 machines here - in those we normally
155 * don't need any ZONE_NORMAL reservation
157 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
158 #ifdef CONFIG_ZONE_DMA
161 #ifdef CONFIG_ZONE_DMA32
164 #ifdef CONFIG_HIGHMEM
170 EXPORT_SYMBOL(totalram_pages
);
172 static char * const zone_names
[MAX_NR_ZONES
] = {
173 #ifdef CONFIG_ZONE_DMA
176 #ifdef CONFIG_ZONE_DMA32
180 #ifdef CONFIG_HIGHMEM
186 int min_free_kbytes
= 1024;
188 static unsigned long __meminitdata nr_kernel_pages
;
189 static unsigned long __meminitdata nr_all_pages
;
190 static unsigned long __meminitdata dma_reserve
;
192 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
193 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
194 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
195 static unsigned long __initdata required_kernelcore
;
196 static unsigned long __initdata required_movablecore
;
197 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
199 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
201 EXPORT_SYMBOL(movable_zone
);
202 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
205 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
206 int nr_online_nodes __read_mostly
= 1;
207 EXPORT_SYMBOL(nr_node_ids
);
208 EXPORT_SYMBOL(nr_online_nodes
);
211 int page_group_by_mobility_disabled __read_mostly
;
213 static void set_pageblock_migratetype(struct page
*page
, int migratetype
)
216 if (unlikely(page_group_by_mobility_disabled
))
217 migratetype
= MIGRATE_UNMOVABLE
;
219 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
220 PB_migrate
, PB_migrate_end
);
223 bool oom_killer_disabled __read_mostly
;
225 #ifdef CONFIG_DEBUG_VM
226 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
230 unsigned long pfn
= page_to_pfn(page
);
233 seq
= zone_span_seqbegin(zone
);
234 if (pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
236 else if (pfn
< zone
->zone_start_pfn
)
238 } while (zone_span_seqretry(zone
, seq
));
243 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
245 if (!pfn_valid_within(page_to_pfn(page
)))
247 if (zone
!= page_zone(page
))
253 * Temporary debugging check for pages not lying within a given zone.
255 static int bad_range(struct zone
*zone
, struct page
*page
)
257 if (page_outside_zone_boundaries(zone
, page
))
259 if (!page_is_consistent(zone
, page
))
265 static inline int bad_range(struct zone
*zone
, struct page
*page
)
271 static void bad_page(struct page
*page
)
273 static unsigned long resume
;
274 static unsigned long nr_shown
;
275 static unsigned long nr_unshown
;
277 /* Don't complain about poisoned pages */
278 if (PageHWPoison(page
)) {
279 reset_page_mapcount(page
); /* remove PageBuddy */
284 * Allow a burst of 60 reports, then keep quiet for that minute;
285 * or allow a steady drip of one report per second.
287 if (nr_shown
== 60) {
288 if (time_before(jiffies
, resume
)) {
294 "BUG: Bad page state: %lu messages suppressed\n",
301 resume
= jiffies
+ 60 * HZ
;
303 printk(KERN_ALERT
"BUG: Bad page state in process %s pfn:%05lx\n",
304 current
->comm
, page_to_pfn(page
));
310 /* Leave bad fields for debug, except PageBuddy could make trouble */
311 reset_page_mapcount(page
); /* remove PageBuddy */
312 add_taint(TAINT_BAD_PAGE
);
316 * Higher-order pages are called "compound pages". They are structured thusly:
318 * The first PAGE_SIZE page is called the "head page".
320 * The remaining PAGE_SIZE pages are called "tail pages".
322 * All pages have PG_compound set. All tail pages have their ->first_page
323 * pointing at the head page.
325 * The first tail page's ->lru.next holds the address of the compound page's
326 * put_page() function. Its ->lru.prev holds the order of allocation.
327 * This usage means that zero-order pages may not be compound.
330 static void free_compound_page(struct page
*page
)
332 __free_pages_ok(page
, compound_order(page
));
335 void prep_compound_page(struct page
*page
, unsigned long order
)
338 int nr_pages
= 1 << order
;
340 set_compound_page_dtor(page
, free_compound_page
);
341 set_compound_order(page
, order
);
343 for (i
= 1; i
< nr_pages
; i
++) {
344 struct page
*p
= page
+ i
;
346 set_page_count(p
, 0);
347 p
->first_page
= page
;
351 /* update __split_huge_page_refcount if you change this function */
352 static int destroy_compound_page(struct page
*page
, unsigned long order
)
355 int nr_pages
= 1 << order
;
358 if (unlikely(compound_order(page
) != order
) ||
359 unlikely(!PageHead(page
))) {
364 __ClearPageHead(page
);
366 for (i
= 1; i
< nr_pages
; i
++) {
367 struct page
*p
= page
+ i
;
369 if (unlikely(!PageTail(p
) || (p
->first_page
!= page
))) {
379 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
384 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
385 * and __GFP_HIGHMEM from hard or soft interrupt context.
387 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
388 for (i
= 0; i
< (1 << order
); i
++)
389 clear_highpage(page
+ i
);
392 #ifdef CONFIG_DEBUG_PAGEALLOC
393 unsigned int _debug_guardpage_minorder
;
395 static int __init
debug_guardpage_minorder_setup(char *buf
)
399 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
400 printk(KERN_ERR
"Bad debug_guardpage_minorder value\n");
403 _debug_guardpage_minorder
= res
;
404 printk(KERN_INFO
"Setting debug_guardpage_minorder to %lu\n", res
);
407 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
409 static inline void set_page_guard_flag(struct page
*page
)
411 __set_bit(PAGE_DEBUG_FLAG_GUARD
, &page
->debug_flags
);
414 static inline void clear_page_guard_flag(struct page
*page
)
416 __clear_bit(PAGE_DEBUG_FLAG_GUARD
, &page
->debug_flags
);
419 static inline void set_page_guard_flag(struct page
*page
) { }
420 static inline void clear_page_guard_flag(struct page
*page
) { }
423 static inline void set_page_order(struct page
*page
, int order
)
425 set_page_private(page
, order
);
426 __SetPageBuddy(page
);
429 static inline void rmv_page_order(struct page
*page
)
431 __ClearPageBuddy(page
);
432 set_page_private(page
, 0);
436 * Locate the struct page for both the matching buddy in our
437 * pair (buddy1) and the combined O(n+1) page they form (page).
439 * 1) Any buddy B1 will have an order O twin B2 which satisfies
440 * the following equation:
442 * For example, if the starting buddy (buddy2) is #8 its order
444 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
446 * 2) Any buddy B will have an order O+1 parent P which
447 * satisfies the following equation:
450 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
452 static inline unsigned long
453 __find_buddy_index(unsigned long page_idx
, unsigned int order
)
455 return page_idx
^ (1 << order
);
459 * This function checks whether a page is free && is the buddy
460 * we can do coalesce a page and its buddy if
461 * (a) the buddy is not in a hole &&
462 * (b) the buddy is in the buddy system &&
463 * (c) a page and its buddy have the same order &&
464 * (d) a page and its buddy are in the same zone.
466 * For recording whether a page is in the buddy system, we set ->_mapcount -2.
467 * Setting, clearing, and testing _mapcount -2 is serialized by zone->lock.
469 * For recording page's order, we use page_private(page).
471 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
474 if (!pfn_valid_within(page_to_pfn(buddy
)))
477 if (page_zone_id(page
) != page_zone_id(buddy
))
480 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
481 VM_BUG_ON(page_count(buddy
) != 0);
485 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
486 VM_BUG_ON(page_count(buddy
) != 0);
493 * Freeing function for a buddy system allocator.
495 * The concept of a buddy system is to maintain direct-mapped table
496 * (containing bit values) for memory blocks of various "orders".
497 * The bottom level table contains the map for the smallest allocatable
498 * units of memory (here, pages), and each level above it describes
499 * pairs of units from the levels below, hence, "buddies".
500 * At a high level, all that happens here is marking the table entry
501 * at the bottom level available, and propagating the changes upward
502 * as necessary, plus some accounting needed to play nicely with other
503 * parts of the VM system.
504 * At each level, we keep a list of pages, which are heads of continuous
505 * free pages of length of (1 << order) and marked with _mapcount -2. Page's
506 * order is recorded in page_private(page) field.
507 * So when we are allocating or freeing one, we can derive the state of the
508 * other. That is, if we allocate a small block, and both were
509 * free, the remainder of the region must be split into blocks.
510 * If a block is freed, and its buddy is also free, then this
511 * triggers coalescing into a block of larger size.
516 static inline void __free_one_page(struct page
*page
,
517 struct zone
*zone
, unsigned int order
,
520 unsigned long page_idx
;
521 unsigned long combined_idx
;
522 unsigned long uninitialized_var(buddy_idx
);
525 if (unlikely(PageCompound(page
)))
526 if (unlikely(destroy_compound_page(page
, order
)))
529 VM_BUG_ON(migratetype
== -1);
531 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
533 VM_BUG_ON(page_idx
& ((1 << order
) - 1));
534 VM_BUG_ON(bad_range(zone
, page
));
536 while (order
< MAX_ORDER
-1) {
537 buddy_idx
= __find_buddy_index(page_idx
, order
);
538 buddy
= page
+ (buddy_idx
- page_idx
);
539 if (!page_is_buddy(page
, buddy
, order
))
542 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
543 * merge with it and move up one order.
545 if (page_is_guard(buddy
)) {
546 clear_page_guard_flag(buddy
);
547 set_page_private(page
, 0);
548 __mod_zone_page_state(zone
, NR_FREE_PAGES
, 1 << order
);
550 list_del(&buddy
->lru
);
551 zone
->free_area
[order
].nr_free
--;
552 rmv_page_order(buddy
);
554 combined_idx
= buddy_idx
& page_idx
;
555 page
= page
+ (combined_idx
- page_idx
);
556 page_idx
= combined_idx
;
559 set_page_order(page
, order
);
562 * If this is not the largest possible page, check if the buddy
563 * of the next-highest order is free. If it is, it's possible
564 * that pages are being freed that will coalesce soon. In case,
565 * that is happening, add the free page to the tail of the list
566 * so it's less likely to be used soon and more likely to be merged
567 * as a higher order page
569 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
570 struct page
*higher_page
, *higher_buddy
;
571 combined_idx
= buddy_idx
& page_idx
;
572 higher_page
= page
+ (combined_idx
- page_idx
);
573 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
574 higher_buddy
= page
+ (buddy_idx
- combined_idx
);
575 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
576 list_add_tail(&page
->lru
,
577 &zone
->free_area
[order
].free_list
[migratetype
]);
582 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
584 zone
->free_area
[order
].nr_free
++;
588 * free_page_mlock() -- clean up attempts to free and mlocked() page.
589 * Page should not be on lru, so no need to fix that up.
590 * free_pages_check() will verify...
592 static inline void free_page_mlock(struct page
*page
)
594 __dec_zone_page_state(page
, NR_MLOCK
);
595 __count_vm_event(UNEVICTABLE_MLOCKFREED
);
598 static inline int free_pages_check(struct page
*page
)
600 if (unlikely(page_mapcount(page
) |
601 (page
->mapping
!= NULL
) |
602 (atomic_read(&page
->_count
) != 0) |
603 (page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
) |
604 (mem_cgroup_bad_page_check(page
)))) {
608 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
609 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
614 * Frees a number of pages from the PCP lists
615 * Assumes all pages on list are in same zone, and of same order.
616 * count is the number of pages to free.
618 * If the zone was previously in an "all pages pinned" state then look to
619 * see if this freeing clears that state.
621 * And clear the zone's pages_scanned counter, to hold off the "all pages are
622 * pinned" detection logic.
624 static void free_pcppages_bulk(struct zone
*zone
, int count
,
625 struct per_cpu_pages
*pcp
)
631 spin_lock(&zone
->lock
);
632 zone
->all_unreclaimable
= 0;
633 zone
->pages_scanned
= 0;
637 struct list_head
*list
;
640 * Remove pages from lists in a round-robin fashion. A
641 * batch_free count is maintained that is incremented when an
642 * empty list is encountered. This is so more pages are freed
643 * off fuller lists instead of spinning excessively around empty
648 if (++migratetype
== MIGRATE_PCPTYPES
)
650 list
= &pcp
->lists
[migratetype
];
651 } while (list_empty(list
));
653 /* This is the only non-empty list. Free them all. */
654 if (batch_free
== MIGRATE_PCPTYPES
)
655 batch_free
= to_free
;
658 page
= list_entry(list
->prev
, struct page
, lru
);
659 /* must delete as __free_one_page list manipulates */
660 list_del(&page
->lru
);
661 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
662 __free_one_page(page
, zone
, 0, page_private(page
));
663 trace_mm_page_pcpu_drain(page
, 0, page_private(page
));
664 } while (--to_free
&& --batch_free
&& !list_empty(list
));
666 __mod_zone_page_state(zone
, NR_FREE_PAGES
, count
);
667 spin_unlock(&zone
->lock
);
670 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
,
673 spin_lock(&zone
->lock
);
674 zone
->all_unreclaimable
= 0;
675 zone
->pages_scanned
= 0;
677 __free_one_page(page
, zone
, order
, migratetype
);
678 __mod_zone_page_state(zone
, NR_FREE_PAGES
, 1 << order
);
679 spin_unlock(&zone
->lock
);
682 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
687 trace_mm_page_free(page
, order
);
688 kmemcheck_free_shadow(page
, order
);
691 page
->mapping
= NULL
;
692 for (i
= 0; i
< (1 << order
); i
++)
693 bad
+= free_pages_check(page
+ i
);
697 if (!PageHighMem(page
)) {
698 debug_check_no_locks_freed(page_address(page
),PAGE_SIZE
<<order
);
699 debug_check_no_obj_freed(page_address(page
),
702 arch_free_page(page
, order
);
703 kernel_map_pages(page
, 1 << order
, 0);
708 static void __free_pages_ok(struct page
*page
, unsigned int order
)
711 int wasMlocked
= __TestClearPageMlocked(page
);
713 if (!free_pages_prepare(page
, order
))
716 local_irq_save(flags
);
717 if (unlikely(wasMlocked
))
718 free_page_mlock(page
);
719 __count_vm_events(PGFREE
, 1 << order
);
720 free_one_page(page_zone(page
), page
, order
,
721 get_pageblock_migratetype(page
));
722 local_irq_restore(flags
);
726 * permit the bootmem allocator to evade page validation on high-order frees
728 void __meminit
__free_pages_bootmem(struct page
*page
, unsigned int order
)
731 __ClearPageReserved(page
);
732 set_page_count(page
, 0);
733 set_page_refcounted(page
);
739 for (loop
= 0; loop
< (1 << order
); loop
++) {
740 struct page
*p
= &page
[loop
];
742 if (loop
+ 1 < (1 << order
))
744 __ClearPageReserved(p
);
745 set_page_count(p
, 0);
748 set_page_refcounted(page
);
749 __free_pages(page
, order
);
755 * The order of subdivision here is critical for the IO subsystem.
756 * Please do not alter this order without good reasons and regression
757 * testing. Specifically, as large blocks of memory are subdivided,
758 * the order in which smaller blocks are delivered depends on the order
759 * they're subdivided in this function. This is the primary factor
760 * influencing the order in which pages are delivered to the IO
761 * subsystem according to empirical testing, and this is also justified
762 * by considering the behavior of a buddy system containing a single
763 * large block of memory acted on by a series of small allocations.
764 * This behavior is a critical factor in sglist merging's success.
768 static inline void expand(struct zone
*zone
, struct page
*page
,
769 int low
, int high
, struct free_area
*area
,
772 unsigned long size
= 1 << high
;
778 VM_BUG_ON(bad_range(zone
, &page
[size
]));
780 #ifdef CONFIG_DEBUG_PAGEALLOC
781 if (high
< debug_guardpage_minorder()) {
783 * Mark as guard pages (or page), that will allow to
784 * merge back to allocator when buddy will be freed.
785 * Corresponding page table entries will not be touched,
786 * pages will stay not present in virtual address space
788 INIT_LIST_HEAD(&page
[size
].lru
);
789 set_page_guard_flag(&page
[size
]);
790 set_page_private(&page
[size
], high
);
791 /* Guard pages are not available for any usage */
792 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(1 << high
));
796 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
798 set_page_order(&page
[size
], high
);
803 * This page is about to be returned from the page allocator
805 static inline int check_new_page(struct page
*page
)
807 if (unlikely(page_mapcount(page
) |
808 (page
->mapping
!= NULL
) |
809 (atomic_read(&page
->_count
) != 0) |
810 (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
) |
811 (mem_cgroup_bad_page_check(page
)))) {
818 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
822 for (i
= 0; i
< (1 << order
); i
++) {
823 struct page
*p
= page
+ i
;
824 if (unlikely(check_new_page(p
)))
828 set_page_private(page
, 0);
829 set_page_refcounted(page
);
831 arch_alloc_page(page
, order
);
832 kernel_map_pages(page
, 1 << order
, 1);
834 if (gfp_flags
& __GFP_ZERO
)
835 prep_zero_page(page
, order
, gfp_flags
);
837 if (order
&& (gfp_flags
& __GFP_COMP
))
838 prep_compound_page(page
, order
);
844 * Go through the free lists for the given migratetype and remove
845 * the smallest available page from the freelists
848 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
851 unsigned int current_order
;
852 struct free_area
* area
;
855 /* Find a page of the appropriate size in the preferred list */
856 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
857 area
= &(zone
->free_area
[current_order
]);
858 if (list_empty(&area
->free_list
[migratetype
]))
861 page
= list_entry(area
->free_list
[migratetype
].next
,
863 list_del(&page
->lru
);
864 rmv_page_order(page
);
866 expand(zone
, page
, order
, current_order
, area
, migratetype
);
875 * This array describes the order lists are fallen back to when
876 * the free lists for the desirable migrate type are depleted
878 static int fallbacks
[MIGRATE_TYPES
][MIGRATE_TYPES
-1] = {
879 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
880 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
881 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
882 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
, MIGRATE_RESERVE
, MIGRATE_RESERVE
}, /* Never used */
886 * Move the free pages in a range to the free lists of the requested type.
887 * Note that start_page and end_pages are not aligned on a pageblock
888 * boundary. If alignment is required, use move_freepages_block()
890 static int move_freepages(struct zone
*zone
,
891 struct page
*start_page
, struct page
*end_page
,
898 #ifndef CONFIG_HOLES_IN_ZONE
900 * page_zone is not safe to call in this context when
901 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
902 * anyway as we check zone boundaries in move_freepages_block().
903 * Remove at a later date when no bug reports exist related to
904 * grouping pages by mobility
906 BUG_ON(page_zone(start_page
) != page_zone(end_page
));
909 for (page
= start_page
; page
<= end_page
;) {
910 /* Make sure we are not inadvertently changing nodes */
911 VM_BUG_ON(page_to_nid(page
) != zone_to_nid(zone
));
913 if (!pfn_valid_within(page_to_pfn(page
))) {
918 if (!PageBuddy(page
)) {
923 order
= page_order(page
);
924 list_move(&page
->lru
,
925 &zone
->free_area
[order
].free_list
[migratetype
]);
927 pages_moved
+= 1 << order
;
933 static int move_freepages_block(struct zone
*zone
, struct page
*page
,
936 unsigned long start_pfn
, end_pfn
;
937 struct page
*start_page
, *end_page
;
939 start_pfn
= page_to_pfn(page
);
940 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
941 start_page
= pfn_to_page(start_pfn
);
942 end_page
= start_page
+ pageblock_nr_pages
- 1;
943 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
945 /* Do not cross zone boundaries */
946 if (start_pfn
< zone
->zone_start_pfn
)
948 if (end_pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
951 return move_freepages(zone
, start_page
, end_page
, migratetype
);
954 static void change_pageblock_range(struct page
*pageblock_page
,
955 int start_order
, int migratetype
)
957 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
959 while (nr_pageblocks
--) {
960 set_pageblock_migratetype(pageblock_page
, migratetype
);
961 pageblock_page
+= pageblock_nr_pages
;
965 /* Remove an element from the buddy allocator from the fallback list */
966 static inline struct page
*
967 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
)
969 struct free_area
* area
;
974 /* Find the largest possible block of pages in the other list */
975 for (current_order
= MAX_ORDER
-1; current_order
>= order
;
977 for (i
= 0; i
< MIGRATE_TYPES
- 1; i
++) {
978 migratetype
= fallbacks
[start_migratetype
][i
];
980 /* MIGRATE_RESERVE handled later if necessary */
981 if (migratetype
== MIGRATE_RESERVE
)
984 area
= &(zone
->free_area
[current_order
]);
985 if (list_empty(&area
->free_list
[migratetype
]))
988 page
= list_entry(area
->free_list
[migratetype
].next
,
993 * If breaking a large block of pages, move all free
994 * pages to the preferred allocation list. If falling
995 * back for a reclaimable kernel allocation, be more
996 * aggressive about taking ownership of free pages
998 if (unlikely(current_order
>= (pageblock_order
>> 1)) ||
999 start_migratetype
== MIGRATE_RECLAIMABLE
||
1000 page_group_by_mobility_disabled
) {
1001 unsigned long pages
;
1002 pages
= move_freepages_block(zone
, page
,
1005 /* Claim the whole block if over half of it is free */
1006 if (pages
>= (1 << (pageblock_order
-1)) ||
1007 page_group_by_mobility_disabled
)
1008 set_pageblock_migratetype(page
,
1011 migratetype
= start_migratetype
;
1014 /* Remove the page from the freelists */
1015 list_del(&page
->lru
);
1016 rmv_page_order(page
);
1018 /* Take ownership for orders >= pageblock_order */
1019 if (current_order
>= pageblock_order
)
1020 change_pageblock_range(page
, current_order
,
1023 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1025 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
1026 start_migratetype
, migratetype
);
1036 * Do the hard work of removing an element from the buddy allocator.
1037 * Call me with the zone->lock already held.
1039 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
1045 page
= __rmqueue_smallest(zone
, order
, migratetype
);
1047 if (unlikely(!page
) && migratetype
!= MIGRATE_RESERVE
) {
1048 page
= __rmqueue_fallback(zone
, order
, migratetype
);
1051 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1052 * is used because __rmqueue_smallest is an inline function
1053 * and we want just one call site
1056 migratetype
= MIGRATE_RESERVE
;
1061 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1066 * Obtain a specified number of elements from the buddy allocator, all under
1067 * a single hold of the lock, for efficiency. Add them to the supplied list.
1068 * Returns the number of new pages which were placed at *list.
1070 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1071 unsigned long count
, struct list_head
*list
,
1072 int migratetype
, int cold
)
1076 spin_lock(&zone
->lock
);
1077 for (i
= 0; i
< count
; ++i
) {
1078 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
1079 if (unlikely(page
== NULL
))
1083 * Split buddy pages returned by expand() are received here
1084 * in physical page order. The page is added to the callers and
1085 * list and the list head then moves forward. From the callers
1086 * perspective, the linked list is ordered by page number in
1087 * some conditions. This is useful for IO devices that can
1088 * merge IO requests if the physical pages are ordered
1091 if (likely(cold
== 0))
1092 list_add(&page
->lru
, list
);
1094 list_add_tail(&page
->lru
, list
);
1095 set_page_private(page
, migratetype
);
1098 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
1099 spin_unlock(&zone
->lock
);
1105 * Called from the vmstat counter updater to drain pagesets of this
1106 * currently executing processor on remote nodes after they have
1109 * Note that this function must be called with the thread pinned to
1110 * a single processor.
1112 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
1114 unsigned long flags
;
1117 local_irq_save(flags
);
1118 if (pcp
->count
>= pcp
->batch
)
1119 to_drain
= pcp
->batch
;
1121 to_drain
= pcp
->count
;
1122 free_pcppages_bulk(zone
, to_drain
, pcp
);
1123 pcp
->count
-= to_drain
;
1124 local_irq_restore(flags
);
1129 * Drain pages of the indicated processor.
1131 * The processor must either be the current processor and the
1132 * thread pinned to the current processor or a processor that
1135 static void drain_pages(unsigned int cpu
)
1137 unsigned long flags
;
1140 for_each_populated_zone(zone
) {
1141 struct per_cpu_pageset
*pset
;
1142 struct per_cpu_pages
*pcp
;
1144 local_irq_save(flags
);
1145 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
1149 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1152 local_irq_restore(flags
);
1157 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1159 void drain_local_pages(void *arg
)
1161 drain_pages(smp_processor_id());
1165 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
1167 void drain_all_pages(void)
1169 on_each_cpu(drain_local_pages
, NULL
, 1);
1172 #ifdef CONFIG_HIBERNATION
1174 void mark_free_pages(struct zone
*zone
)
1176 unsigned long pfn
, max_zone_pfn
;
1177 unsigned long flags
;
1179 struct list_head
*curr
;
1181 if (!zone
->spanned_pages
)
1184 spin_lock_irqsave(&zone
->lock
, flags
);
1186 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
1187 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1188 if (pfn_valid(pfn
)) {
1189 struct page
*page
= pfn_to_page(pfn
);
1191 if (!swsusp_page_is_forbidden(page
))
1192 swsusp_unset_page_free(page
);
1195 for_each_migratetype_order(order
, t
) {
1196 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
1199 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
1200 for (i
= 0; i
< (1UL << order
); i
++)
1201 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
1204 spin_unlock_irqrestore(&zone
->lock
, flags
);
1206 #endif /* CONFIG_PM */
1209 * Free a 0-order page
1210 * cold == 1 ? free a cold page : free a hot page
1212 void free_hot_cold_page(struct page
*page
, int cold
)
1214 struct zone
*zone
= page_zone(page
);
1215 struct per_cpu_pages
*pcp
;
1216 unsigned long flags
;
1218 int wasMlocked
= __TestClearPageMlocked(page
);
1220 if (!free_pages_prepare(page
, 0))
1223 migratetype
= get_pageblock_migratetype(page
);
1224 set_page_private(page
, migratetype
);
1225 local_irq_save(flags
);
1226 if (unlikely(wasMlocked
))
1227 free_page_mlock(page
);
1228 __count_vm_event(PGFREE
);
1231 * We only track unmovable, reclaimable and movable on pcp lists.
1232 * Free ISOLATE pages back to the allocator because they are being
1233 * offlined but treat RESERVE as movable pages so we can get those
1234 * areas back if necessary. Otherwise, we may have to free
1235 * excessively into the page allocator
1237 if (migratetype
>= MIGRATE_PCPTYPES
) {
1238 if (unlikely(migratetype
== MIGRATE_ISOLATE
)) {
1239 free_one_page(zone
, page
, 0, migratetype
);
1242 migratetype
= MIGRATE_MOVABLE
;
1245 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1247 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
1249 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
1251 if (pcp
->count
>= pcp
->high
) {
1252 free_pcppages_bulk(zone
, pcp
->batch
, pcp
);
1253 pcp
->count
-= pcp
->batch
;
1257 local_irq_restore(flags
);
1261 * Free a list of 0-order pages
1263 void free_hot_cold_page_list(struct list_head
*list
, int cold
)
1265 struct page
*page
, *next
;
1267 list_for_each_entry_safe(page
, next
, list
, lru
) {
1268 trace_mm_page_free_batched(page
, cold
);
1269 free_hot_cold_page(page
, cold
);
1274 * split_page takes a non-compound higher-order page, and splits it into
1275 * n (1<<order) sub-pages: page[0..n]
1276 * Each sub-page must be freed individually.
1278 * Note: this is probably too low level an operation for use in drivers.
1279 * Please consult with lkml before using this in your driver.
1281 void split_page(struct page
*page
, unsigned int order
)
1285 VM_BUG_ON(PageCompound(page
));
1286 VM_BUG_ON(!page_count(page
));
1288 #ifdef CONFIG_KMEMCHECK
1290 * Split shadow pages too, because free(page[0]) would
1291 * otherwise free the whole shadow.
1293 if (kmemcheck_page_is_tracked(page
))
1294 split_page(virt_to_page(page
[0].shadow
), order
);
1297 for (i
= 1; i
< (1 << order
); i
++)
1298 set_page_refcounted(page
+ i
);
1302 * Similar to split_page except the page is already free. As this is only
1303 * being used for migration, the migratetype of the block also changes.
1304 * As this is called with interrupts disabled, the caller is responsible
1305 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1308 * Note: this is probably too low level an operation for use in drivers.
1309 * Please consult with lkml before using this in your driver.
1311 int split_free_page(struct page
*page
)
1314 unsigned long watermark
;
1317 BUG_ON(!PageBuddy(page
));
1319 zone
= page_zone(page
);
1320 order
= page_order(page
);
1322 /* Obey watermarks as if the page was being allocated */
1323 watermark
= low_wmark_pages(zone
) + (1 << order
);
1324 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
1327 /* Remove page from free list */
1328 list_del(&page
->lru
);
1329 zone
->free_area
[order
].nr_free
--;
1330 rmv_page_order(page
);
1331 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(1UL << order
));
1333 /* Split into individual pages */
1334 set_page_refcounted(page
);
1335 split_page(page
, order
);
1337 if (order
>= pageblock_order
- 1) {
1338 struct page
*endpage
= page
+ (1 << order
) - 1;
1339 for (; page
< endpage
; page
+= pageblock_nr_pages
)
1340 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1347 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1348 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1352 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
1353 struct zone
*zone
, int order
, gfp_t gfp_flags
,
1356 unsigned long flags
;
1358 int cold
= !!(gfp_flags
& __GFP_COLD
);
1361 if (likely(order
== 0)) {
1362 struct per_cpu_pages
*pcp
;
1363 struct list_head
*list
;
1365 local_irq_save(flags
);
1366 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1367 list
= &pcp
->lists
[migratetype
];
1368 if (list_empty(list
)) {
1369 pcp
->count
+= rmqueue_bulk(zone
, 0,
1372 if (unlikely(list_empty(list
)))
1377 page
= list_entry(list
->prev
, struct page
, lru
);
1379 page
= list_entry(list
->next
, struct page
, lru
);
1381 list_del(&page
->lru
);
1384 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
1386 * __GFP_NOFAIL is not to be used in new code.
1388 * All __GFP_NOFAIL callers should be fixed so that they
1389 * properly detect and handle allocation failures.
1391 * We most definitely don't want callers attempting to
1392 * allocate greater than order-1 page units with
1395 WARN_ON_ONCE(order
> 1);
1397 spin_lock_irqsave(&zone
->lock
, flags
);
1398 page
= __rmqueue(zone
, order
, migratetype
);
1399 spin_unlock(&zone
->lock
);
1402 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(1 << order
));
1405 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
1406 zone_statistics(preferred_zone
, zone
, gfp_flags
);
1407 local_irq_restore(flags
);
1409 VM_BUG_ON(bad_range(zone
, page
));
1410 if (prep_new_page(page
, order
, gfp_flags
))
1415 local_irq_restore(flags
);
1419 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
1420 #define ALLOC_WMARK_MIN WMARK_MIN
1421 #define ALLOC_WMARK_LOW WMARK_LOW
1422 #define ALLOC_WMARK_HIGH WMARK_HIGH
1423 #define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
1425 /* Mask to get the watermark bits */
1426 #define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
1428 #define ALLOC_HARDER 0x10 /* try to alloc harder */
1429 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
1430 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */
1432 #ifdef CONFIG_FAIL_PAGE_ALLOC
1435 struct fault_attr attr
;
1437 u32 ignore_gfp_highmem
;
1438 u32 ignore_gfp_wait
;
1440 } fail_page_alloc
= {
1441 .attr
= FAULT_ATTR_INITIALIZER
,
1442 .ignore_gfp_wait
= 1,
1443 .ignore_gfp_highmem
= 1,
1447 static int __init
setup_fail_page_alloc(char *str
)
1449 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
1451 __setup("fail_page_alloc=", setup_fail_page_alloc
);
1453 static int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1455 if (order
< fail_page_alloc
.min_order
)
1457 if (gfp_mask
& __GFP_NOFAIL
)
1459 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
1461 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
1464 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
1467 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1469 static int __init
fail_page_alloc_debugfs(void)
1471 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
1474 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
1475 &fail_page_alloc
.attr
);
1477 return PTR_ERR(dir
);
1479 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
1480 &fail_page_alloc
.ignore_gfp_wait
))
1482 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
1483 &fail_page_alloc
.ignore_gfp_highmem
))
1485 if (!debugfs_create_u32("min-order", mode
, dir
,
1486 &fail_page_alloc
.min_order
))
1491 debugfs_remove_recursive(dir
);
1496 late_initcall(fail_page_alloc_debugfs
);
1498 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1500 #else /* CONFIG_FAIL_PAGE_ALLOC */
1502 static inline int should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1507 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1510 * Return true if free pages are above 'mark'. This takes into account the order
1511 * of the allocation.
1513 static bool __zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1514 int classzone_idx
, int alloc_flags
, long free_pages
)
1516 /* free_pages my go negative - that's OK */
1520 free_pages
-= (1 << order
) + 1;
1521 if (alloc_flags
& ALLOC_HIGH
)
1523 if (alloc_flags
& ALLOC_HARDER
)
1526 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
1528 for (o
= 0; o
< order
; o
++) {
1529 /* At the next order, this order's pages become unavailable */
1530 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1532 /* Require fewer higher order pages to be free */
1535 if (free_pages
<= min
)
1541 bool zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1542 int classzone_idx
, int alloc_flags
)
1544 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1545 zone_page_state(z
, NR_FREE_PAGES
));
1548 bool zone_watermark_ok_safe(struct zone
*z
, int order
, unsigned long mark
,
1549 int classzone_idx
, int alloc_flags
)
1551 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
1553 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
1554 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
1556 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1562 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1563 * skip over zones that are not allowed by the cpuset, or that have
1564 * been recently (in last second) found to be nearly full. See further
1565 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1566 * that have to skip over a lot of full or unallowed zones.
1568 * If the zonelist cache is present in the passed in zonelist, then
1569 * returns a pointer to the allowed node mask (either the current
1570 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1572 * If the zonelist cache is not available for this zonelist, does
1573 * nothing and returns NULL.
1575 * If the fullzones BITMAP in the zonelist cache is stale (more than
1576 * a second since last zap'd) then we zap it out (clear its bits.)
1578 * We hold off even calling zlc_setup, until after we've checked the
1579 * first zone in the zonelist, on the theory that most allocations will
1580 * be satisfied from that first zone, so best to examine that zone as
1581 * quickly as we can.
1583 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1585 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1586 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1588 zlc
= zonelist
->zlcache_ptr
;
1592 if (time_after(jiffies
, zlc
->last_full_zap
+ HZ
)) {
1593 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1594 zlc
->last_full_zap
= jiffies
;
1597 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1598 &cpuset_current_mems_allowed
:
1599 &node_states
[N_HIGH_MEMORY
];
1600 return allowednodes
;
1604 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1605 * if it is worth looking at further for free memory:
1606 * 1) Check that the zone isn't thought to be full (doesn't have its
1607 * bit set in the zonelist_cache fullzones BITMAP).
1608 * 2) Check that the zones node (obtained from the zonelist_cache
1609 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1610 * Return true (non-zero) if zone is worth looking at further, or
1611 * else return false (zero) if it is not.
1613 * This check -ignores- the distinction between various watermarks,
1614 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1615 * found to be full for any variation of these watermarks, it will
1616 * be considered full for up to one second by all requests, unless
1617 * we are so low on memory on all allowed nodes that we are forced
1618 * into the second scan of the zonelist.
1620 * In the second scan we ignore this zonelist cache and exactly
1621 * apply the watermarks to all zones, even it is slower to do so.
1622 * We are low on memory in the second scan, and should leave no stone
1623 * unturned looking for a free page.
1625 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1626 nodemask_t
*allowednodes
)
1628 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1629 int i
; /* index of *z in zonelist zones */
1630 int n
; /* node that zone *z is on */
1632 zlc
= zonelist
->zlcache_ptr
;
1636 i
= z
- zonelist
->_zonerefs
;
1639 /* This zone is worth trying if it is allowed but not full */
1640 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1644 * Given 'z' scanning a zonelist, set the corresponding bit in
1645 * zlc->fullzones, so that subsequent attempts to allocate a page
1646 * from that zone don't waste time re-examining it.
1648 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1650 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1651 int i
; /* index of *z in zonelist zones */
1653 zlc
= zonelist
->zlcache_ptr
;
1657 i
= z
- zonelist
->_zonerefs
;
1659 set_bit(i
, zlc
->fullzones
);
1663 * clear all zones full, called after direct reclaim makes progress so that
1664 * a zone that was recently full is not skipped over for up to a second
1666 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
1668 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1670 zlc
= zonelist
->zlcache_ptr
;
1674 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1677 #else /* CONFIG_NUMA */
1679 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1684 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1685 nodemask_t
*allowednodes
)
1690 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1694 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
1697 #endif /* CONFIG_NUMA */
1700 * get_page_from_freelist goes through the zonelist trying to allocate
1703 static struct page
*
1704 get_page_from_freelist(gfp_t gfp_mask
, nodemask_t
*nodemask
, unsigned int order
,
1705 struct zonelist
*zonelist
, int high_zoneidx
, int alloc_flags
,
1706 struct zone
*preferred_zone
, int migratetype
)
1709 struct page
*page
= NULL
;
1712 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1713 int zlc_active
= 0; /* set if using zonelist_cache */
1714 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1716 classzone_idx
= zone_idx(preferred_zone
);
1719 * Scan zonelist, looking for a zone with enough free.
1720 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1722 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
1723 high_zoneidx
, nodemask
) {
1724 if (NUMA_BUILD
&& zlc_active
&&
1725 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1727 if ((alloc_flags
& ALLOC_CPUSET
) &&
1728 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1731 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
1732 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
1736 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
1737 if (zone_watermark_ok(zone
, order
, mark
,
1738 classzone_idx
, alloc_flags
))
1741 if (NUMA_BUILD
&& !did_zlc_setup
&& nr_online_nodes
> 1) {
1743 * we do zlc_setup if there are multiple nodes
1744 * and before considering the first zone allowed
1747 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1752 if (zone_reclaim_mode
== 0)
1753 goto this_zone_full
;
1756 * As we may have just activated ZLC, check if the first
1757 * eligible zone has failed zone_reclaim recently.
1759 if (NUMA_BUILD
&& zlc_active
&&
1760 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1763 ret
= zone_reclaim(zone
, gfp_mask
, order
);
1765 case ZONE_RECLAIM_NOSCAN
:
1768 case ZONE_RECLAIM_FULL
:
1769 /* scanned but unreclaimable */
1772 /* did we reclaim enough */
1773 if (!zone_watermark_ok(zone
, order
, mark
,
1774 classzone_idx
, alloc_flags
))
1775 goto this_zone_full
;
1780 page
= buffered_rmqueue(preferred_zone
, zone
, order
,
1781 gfp_mask
, migratetype
);
1786 zlc_mark_zone_full(zonelist
, z
);
1789 if (unlikely(NUMA_BUILD
&& page
== NULL
&& zlc_active
)) {
1790 /* Disable zlc cache for second zonelist scan */
1798 * Large machines with many possible nodes should not always dump per-node
1799 * meminfo in irq context.
1801 static inline bool should_suppress_show_mem(void)
1806 ret
= in_interrupt();
1811 static DEFINE_RATELIMIT_STATE(nopage_rs
,
1812 DEFAULT_RATELIMIT_INTERVAL
,
1813 DEFAULT_RATELIMIT_BURST
);
1815 void warn_alloc_failed(gfp_t gfp_mask
, int order
, const char *fmt
, ...)
1817 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
1819 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
1820 debug_guardpage_minorder() > 0)
1824 * This documents exceptions given to allocations in certain
1825 * contexts that are allowed to allocate outside current's set
1828 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
1829 if (test_thread_flag(TIF_MEMDIE
) ||
1830 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
1831 filter
&= ~SHOW_MEM_FILTER_NODES
;
1832 if (in_interrupt() || !(gfp_mask
& __GFP_WAIT
))
1833 filter
&= ~SHOW_MEM_FILTER_NODES
;
1836 struct va_format vaf
;
1839 va_start(args
, fmt
);
1844 pr_warn("%pV", &vaf
);
1849 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
1850 current
->comm
, order
, gfp_mask
);
1853 if (!should_suppress_show_mem())
1858 should_alloc_retry(gfp_t gfp_mask
, unsigned int order
,
1859 unsigned long did_some_progress
,
1860 unsigned long pages_reclaimed
)
1862 /* Do not loop if specifically requested */
1863 if (gfp_mask
& __GFP_NORETRY
)
1866 /* Always retry if specifically requested */
1867 if (gfp_mask
& __GFP_NOFAIL
)
1871 * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
1872 * making forward progress without invoking OOM. Suspend also disables
1873 * storage devices so kswapd will not help. Bail if we are suspending.
1875 if (!did_some_progress
&& pm_suspended_storage())
1879 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
1880 * means __GFP_NOFAIL, but that may not be true in other
1883 if (order
<= PAGE_ALLOC_COSTLY_ORDER
)
1887 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
1888 * specified, then we retry until we no longer reclaim any pages
1889 * (above), or we've reclaimed an order of pages at least as
1890 * large as the allocation's order. In both cases, if the
1891 * allocation still fails, we stop retrying.
1893 if (gfp_mask
& __GFP_REPEAT
&& pages_reclaimed
< (1 << order
))
1899 static inline struct page
*
1900 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
1901 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1902 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
1907 /* Acquire the OOM killer lock for the zones in zonelist */
1908 if (!try_set_zonelist_oom(zonelist
, gfp_mask
)) {
1909 schedule_timeout_uninterruptible(1);
1914 * Go through the zonelist yet one more time, keep very high watermark
1915 * here, this is only to catch a parallel oom killing, we must fail if
1916 * we're still under heavy pressure.
1918 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
,
1919 order
, zonelist
, high_zoneidx
,
1920 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
,
1921 preferred_zone
, migratetype
);
1925 if (!(gfp_mask
& __GFP_NOFAIL
)) {
1926 /* The OOM killer will not help higher order allocs */
1927 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
1929 /* The OOM killer does not needlessly kill tasks for lowmem */
1930 if (high_zoneidx
< ZONE_NORMAL
)
1933 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
1934 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
1935 * The caller should handle page allocation failure by itself if
1936 * it specifies __GFP_THISNODE.
1937 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
1939 if (gfp_mask
& __GFP_THISNODE
)
1942 /* Exhausted what can be done so it's blamo time */
1943 out_of_memory(zonelist
, gfp_mask
, order
, nodemask
);
1946 clear_zonelist_oom(zonelist
, gfp_mask
);
1950 #ifdef CONFIG_COMPACTION
1951 /* Try memory compaction for high-order allocations before reclaim */
1952 static struct page
*
1953 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
1954 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
1955 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
1956 int migratetype
, unsigned long *did_some_progress
,
1957 bool sync_migration
)
1961 if (!order
|| compaction_deferred(preferred_zone
))
1964 current
->flags
|= PF_MEMALLOC
;
1965 *did_some_progress
= try_to_compact_pages(zonelist
, order
, gfp_mask
,
1966 nodemask
, sync_migration
);
1967 current
->flags
&= ~PF_MEMALLOC
;
1968 if (*did_some_progress
!= COMPACT_SKIPPED
) {
1970 /* Page migration frees to the PCP lists but we want merging */
1971 drain_pages(get_cpu());
1974 page
= get_page_from_freelist(gfp_mask
, nodemask
,
1975 order
, zonelist
, high_zoneidx
,
1976 alloc_flags
, preferred_zone
,
1979 preferred_zone
->compact_considered
= 0;
1980 preferred_zone
->compact_defer_shift
= 0;
1981 count_vm_event(COMPACTSUCCESS
);
1986 * It's bad if compaction run occurs and fails.
1987 * The most likely reason is that pages exist,
1988 * but not enough to satisfy watermarks.
1990 count_vm_event(COMPACTFAIL
);
1991 defer_compaction(preferred_zone
);
1999 static inline struct page
*
2000 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2001 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2002 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2003 int migratetype
, unsigned long *did_some_progress
,
2004 bool sync_migration
)
2008 #endif /* CONFIG_COMPACTION */
2010 /* The really slow allocator path where we enter direct reclaim */
2011 static inline struct page
*
2012 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
2013 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2014 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2015 int migratetype
, unsigned long *did_some_progress
)
2017 struct page
*page
= NULL
;
2018 struct reclaim_state reclaim_state
;
2019 bool drained
= false;
2023 /* We now go into synchronous reclaim */
2024 cpuset_memory_pressure_bump();
2025 current
->flags
|= PF_MEMALLOC
;
2026 lockdep_set_current_reclaim_state(gfp_mask
);
2027 reclaim_state
.reclaimed_slab
= 0;
2028 current
->reclaim_state
= &reclaim_state
;
2030 *did_some_progress
= try_to_free_pages(zonelist
, order
, gfp_mask
, nodemask
);
2032 current
->reclaim_state
= NULL
;
2033 lockdep_clear_current_reclaim_state();
2034 current
->flags
&= ~PF_MEMALLOC
;
2038 if (unlikely(!(*did_some_progress
)))
2041 /* After successful reclaim, reconsider all zones for allocation */
2043 zlc_clear_zones_full(zonelist
);
2046 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
2047 zonelist
, high_zoneidx
,
2048 alloc_flags
, preferred_zone
,
2052 * If an allocation failed after direct reclaim, it could be because
2053 * pages are pinned on the per-cpu lists. Drain them and try again
2055 if (!page
&& !drained
) {
2065 * This is called in the allocator slow-path if the allocation request is of
2066 * sufficient urgency to ignore watermarks and take other desperate measures
2068 static inline struct page
*
2069 __alloc_pages_high_priority(gfp_t gfp_mask
, unsigned int order
,
2070 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2071 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2077 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
2078 zonelist
, high_zoneidx
, ALLOC_NO_WATERMARKS
,
2079 preferred_zone
, migratetype
);
2081 if (!page
&& gfp_mask
& __GFP_NOFAIL
)
2082 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2083 } while (!page
&& (gfp_mask
& __GFP_NOFAIL
));
2089 void wake_all_kswapd(unsigned int order
, struct zonelist
*zonelist
,
2090 enum zone_type high_zoneidx
,
2091 enum zone_type classzone_idx
)
2096 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
)
2097 wakeup_kswapd(zone
, order
, classzone_idx
);
2101 gfp_to_alloc_flags(gfp_t gfp_mask
)
2103 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
2104 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2106 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2107 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
2110 * The caller may dip into page reserves a bit more if the caller
2111 * cannot run direct reclaim, or if the caller has realtime scheduling
2112 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2113 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
2115 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
2119 * Not worth trying to allocate harder for
2120 * __GFP_NOMEMALLOC even if it can't schedule.
2122 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2123 alloc_flags
|= ALLOC_HARDER
;
2125 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
2126 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
2128 alloc_flags
&= ~ALLOC_CPUSET
;
2129 } else if (unlikely(rt_task(current
)) && !in_interrupt())
2130 alloc_flags
|= ALLOC_HARDER
;
2132 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
2133 if (!in_interrupt() &&
2134 ((current
->flags
& PF_MEMALLOC
) ||
2135 unlikely(test_thread_flag(TIF_MEMDIE
))))
2136 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2142 static inline struct page
*
2143 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
2144 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2145 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2148 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2149 struct page
*page
= NULL
;
2151 unsigned long pages_reclaimed
= 0;
2152 unsigned long did_some_progress
;
2153 bool sync_migration
= false;
2156 * In the slowpath, we sanity check order to avoid ever trying to
2157 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2158 * be using allocators in order of preference for an area that is
2161 if (order
>= MAX_ORDER
) {
2162 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
2167 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
2168 * __GFP_NOWARN set) should not cause reclaim since the subsystem
2169 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
2170 * using a larger set of nodes after it has established that the
2171 * allowed per node queues are empty and that nodes are
2174 if (NUMA_BUILD
&& (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
2178 if (!(gfp_mask
& __GFP_NO_KSWAPD
))
2179 wake_all_kswapd(order
, zonelist
, high_zoneidx
,
2180 zone_idx(preferred_zone
));
2183 * OK, we're below the kswapd watermark and have kicked background
2184 * reclaim. Now things get more complex, so set up alloc_flags according
2185 * to how we want to proceed.
2187 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
2190 * Find the true preferred zone if the allocation is unconstrained by
2193 if (!(alloc_flags
& ALLOC_CPUSET
) && !nodemask
)
2194 first_zones_zonelist(zonelist
, high_zoneidx
, NULL
,
2198 /* This is the last chance, in general, before the goto nopage. */
2199 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
, zonelist
,
2200 high_zoneidx
, alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2201 preferred_zone
, migratetype
);
2205 /* Allocate without watermarks if the context allows */
2206 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
2207 page
= __alloc_pages_high_priority(gfp_mask
, order
,
2208 zonelist
, high_zoneidx
, nodemask
,
2209 preferred_zone
, migratetype
);
2214 /* Atomic allocations - we can't balance anything */
2218 /* Avoid recursion of direct reclaim */
2219 if (current
->flags
& PF_MEMALLOC
)
2222 /* Avoid allocations with no watermarks from looping endlessly */
2223 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
2227 * Try direct compaction. The first pass is asynchronous. Subsequent
2228 * attempts after direct reclaim are synchronous
2230 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
2231 zonelist
, high_zoneidx
,
2233 alloc_flags
, preferred_zone
,
2234 migratetype
, &did_some_progress
,
2238 sync_migration
= true;
2240 /* Try direct reclaim and then allocating */
2241 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
,
2242 zonelist
, high_zoneidx
,
2244 alloc_flags
, preferred_zone
,
2245 migratetype
, &did_some_progress
);
2250 * If we failed to make any progress reclaiming, then we are
2251 * running out of options and have to consider going OOM
2253 if (!did_some_progress
) {
2254 if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
2255 if (oom_killer_disabled
)
2257 page
= __alloc_pages_may_oom(gfp_mask
, order
,
2258 zonelist
, high_zoneidx
,
2259 nodemask
, preferred_zone
,
2264 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2266 * The oom killer is not called for high-order
2267 * allocations that may fail, so if no progress
2268 * is being made, there are no other options and
2269 * retrying is unlikely to help.
2271 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2274 * The oom killer is not called for lowmem
2275 * allocations to prevent needlessly killing
2278 if (high_zoneidx
< ZONE_NORMAL
)
2286 /* Check if we should retry the allocation */
2287 pages_reclaimed
+= did_some_progress
;
2288 if (should_alloc_retry(gfp_mask
, order
, did_some_progress
,
2290 /* Wait for some write requests to complete then retry */
2291 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2295 * High-order allocations do not necessarily loop after
2296 * direct reclaim and reclaim/compaction depends on compaction
2297 * being called after reclaim so call directly if necessary
2299 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
2300 zonelist
, high_zoneidx
,
2302 alloc_flags
, preferred_zone
,
2303 migratetype
, &did_some_progress
,
2310 warn_alloc_failed(gfp_mask
, order
, NULL
);
2313 if (kmemcheck_enabled
)
2314 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
2320 * This is the 'heart' of the zoned buddy allocator.
2323 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
2324 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
2326 enum zone_type high_zoneidx
= gfp_zone(gfp_mask
);
2327 struct zone
*preferred_zone
;
2329 int migratetype
= allocflags_to_migratetype(gfp_mask
);
2331 gfp_mask
&= gfp_allowed_mask
;
2333 lockdep_trace_alloc(gfp_mask
);
2335 might_sleep_if(gfp_mask
& __GFP_WAIT
);
2337 if (should_fail_alloc_page(gfp_mask
, order
))
2341 * Check the zones suitable for the gfp_mask contain at least one
2342 * valid zone. It's possible to have an empty zonelist as a result
2343 * of GFP_THISNODE and a memoryless node
2345 if (unlikely(!zonelist
->_zonerefs
->zone
))
2349 /* The preferred zone is used for statistics later */
2350 first_zones_zonelist(zonelist
, high_zoneidx
,
2351 nodemask
? : &cpuset_current_mems_allowed
,
2353 if (!preferred_zone
) {
2358 /* First allocation attempt */
2359 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
, order
,
2360 zonelist
, high_zoneidx
, ALLOC_WMARK_LOW
|ALLOC_CPUSET
,
2361 preferred_zone
, migratetype
);
2362 if (unlikely(!page
))
2363 page
= __alloc_pages_slowpath(gfp_mask
, order
,
2364 zonelist
, high_zoneidx
, nodemask
,
2365 preferred_zone
, migratetype
);
2368 trace_mm_page_alloc(page
, order
, gfp_mask
, migratetype
);
2371 EXPORT_SYMBOL(__alloc_pages_nodemask
);
2374 * Common helper functions.
2376 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
2381 * __get_free_pages() returns a 32-bit address, which cannot represent
2384 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
2386 page
= alloc_pages(gfp_mask
, order
);
2389 return (unsigned long) page_address(page
);
2391 EXPORT_SYMBOL(__get_free_pages
);
2393 unsigned long get_zeroed_page(gfp_t gfp_mask
)
2395 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
2397 EXPORT_SYMBOL(get_zeroed_page
);
2399 void __free_pages(struct page
*page
, unsigned int order
)
2401 if (put_page_testzero(page
)) {
2403 free_hot_cold_page(page
, 0);
2405 __free_pages_ok(page
, order
);
2409 EXPORT_SYMBOL(__free_pages
);
2411 void free_pages(unsigned long addr
, unsigned int order
)
2414 VM_BUG_ON(!virt_addr_valid((void *)addr
));
2415 __free_pages(virt_to_page((void *)addr
), order
);
2419 EXPORT_SYMBOL(free_pages
);
2421 static void *make_alloc_exact(unsigned long addr
, unsigned order
, size_t size
)
2424 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
2425 unsigned long used
= addr
+ PAGE_ALIGN(size
);
2427 split_page(virt_to_page((void *)addr
), order
);
2428 while (used
< alloc_end
) {
2433 return (void *)addr
;
2437 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2438 * @size: the number of bytes to allocate
2439 * @gfp_mask: GFP flags for the allocation
2441 * This function is similar to alloc_pages(), except that it allocates the
2442 * minimum number of pages to satisfy the request. alloc_pages() can only
2443 * allocate memory in power-of-two pages.
2445 * This function is also limited by MAX_ORDER.
2447 * Memory allocated by this function must be released by free_pages_exact().
2449 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
2451 unsigned int order
= get_order(size
);
2454 addr
= __get_free_pages(gfp_mask
, order
);
2455 return make_alloc_exact(addr
, order
, size
);
2457 EXPORT_SYMBOL(alloc_pages_exact
);
2460 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
2462 * @nid: the preferred node ID where memory should be allocated
2463 * @size: the number of bytes to allocate
2464 * @gfp_mask: GFP flags for the allocation
2466 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
2468 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
2471 void *alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
2473 unsigned order
= get_order(size
);
2474 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
2477 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
2479 EXPORT_SYMBOL(alloc_pages_exact_nid
);
2482 * free_pages_exact - release memory allocated via alloc_pages_exact()
2483 * @virt: the value returned by alloc_pages_exact.
2484 * @size: size of allocation, same value as passed to alloc_pages_exact().
2486 * Release the memory allocated by a previous call to alloc_pages_exact.
2488 void free_pages_exact(void *virt
, size_t size
)
2490 unsigned long addr
= (unsigned long)virt
;
2491 unsigned long end
= addr
+ PAGE_ALIGN(size
);
2493 while (addr
< end
) {
2498 EXPORT_SYMBOL(free_pages_exact
);
2500 static unsigned int nr_free_zone_pages(int offset
)
2505 /* Just pick one node, since fallback list is circular */
2506 unsigned int sum
= 0;
2508 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
2510 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
2511 unsigned long size
= zone
->present_pages
;
2512 unsigned long high
= high_wmark_pages(zone
);
2521 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
2523 unsigned int nr_free_buffer_pages(void)
2525 return nr_free_zone_pages(gfp_zone(GFP_USER
));
2527 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
2530 * Amount of free RAM allocatable within all zones
2532 unsigned int nr_free_pagecache_pages(void)
2534 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
2537 static inline void show_node(struct zone
*zone
)
2540 printk("Node %d ", zone_to_nid(zone
));
2543 void si_meminfo(struct sysinfo
*val
)
2545 val
->totalram
= totalram_pages
;
2547 val
->freeram
= global_page_state(NR_FREE_PAGES
);
2548 val
->bufferram
= nr_blockdev_pages();
2549 val
->totalhigh
= totalhigh_pages
;
2550 val
->freehigh
= nr_free_highpages();
2551 val
->mem_unit
= PAGE_SIZE
;
2554 EXPORT_SYMBOL(si_meminfo
);
2557 void si_meminfo_node(struct sysinfo
*val
, int nid
)
2559 pg_data_t
*pgdat
= NODE_DATA(nid
);
2561 val
->totalram
= pgdat
->node_present_pages
;
2562 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
2563 #ifdef CONFIG_HIGHMEM
2564 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
2565 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
2571 val
->mem_unit
= PAGE_SIZE
;
2576 * Determine whether the node should be displayed or not, depending on whether
2577 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
2579 bool skip_free_areas_node(unsigned int flags
, int nid
)
2583 if (!(flags
& SHOW_MEM_FILTER_NODES
))
2587 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
2593 #define K(x) ((x) << (PAGE_SHIFT-10))
2596 * Show free area list (used inside shift_scroll-lock stuff)
2597 * We also calculate the percentage fragmentation. We do this by counting the
2598 * memory on each free list with the exception of the first item on the list.
2599 * Suppresses nodes that are not allowed by current's cpuset if
2600 * SHOW_MEM_FILTER_NODES is passed.
2602 void show_free_areas(unsigned int filter
)
2607 for_each_populated_zone(zone
) {
2608 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
2611 printk("%s per-cpu:\n", zone
->name
);
2613 for_each_online_cpu(cpu
) {
2614 struct per_cpu_pageset
*pageset
;
2616 pageset
= per_cpu_ptr(zone
->pageset
, cpu
);
2618 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
2619 cpu
, pageset
->pcp
.high
,
2620 pageset
->pcp
.batch
, pageset
->pcp
.count
);
2624 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
2625 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
2627 " dirty:%lu writeback:%lu unstable:%lu\n"
2628 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2629 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
2630 global_page_state(NR_ACTIVE_ANON
),
2631 global_page_state(NR_INACTIVE_ANON
),
2632 global_page_state(NR_ISOLATED_ANON
),
2633 global_page_state(NR_ACTIVE_FILE
),
2634 global_page_state(NR_INACTIVE_FILE
),
2635 global_page_state(NR_ISOLATED_FILE
),
2636 global_page_state(NR_UNEVICTABLE
),
2637 global_page_state(NR_FILE_DIRTY
),
2638 global_page_state(NR_WRITEBACK
),
2639 global_page_state(NR_UNSTABLE_NFS
),
2640 global_page_state(NR_FREE_PAGES
),
2641 global_page_state(NR_SLAB_RECLAIMABLE
),
2642 global_page_state(NR_SLAB_UNRECLAIMABLE
),
2643 global_page_state(NR_FILE_MAPPED
),
2644 global_page_state(NR_SHMEM
),
2645 global_page_state(NR_PAGETABLE
),
2646 global_page_state(NR_BOUNCE
));
2648 for_each_populated_zone(zone
) {
2651 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
2659 " active_anon:%lukB"
2660 " inactive_anon:%lukB"
2661 " active_file:%lukB"
2662 " inactive_file:%lukB"
2663 " unevictable:%lukB"
2664 " isolated(anon):%lukB"
2665 " isolated(file):%lukB"
2672 " slab_reclaimable:%lukB"
2673 " slab_unreclaimable:%lukB"
2674 " kernel_stack:%lukB"
2678 " writeback_tmp:%lukB"
2679 " pages_scanned:%lu"
2680 " all_unreclaimable? %s"
2683 K(zone_page_state(zone
, NR_FREE_PAGES
)),
2684 K(min_wmark_pages(zone
)),
2685 K(low_wmark_pages(zone
)),
2686 K(high_wmark_pages(zone
)),
2687 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
2688 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
2689 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
2690 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
2691 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
2692 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
2693 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
2694 K(zone
->present_pages
),
2695 K(zone_page_state(zone
, NR_MLOCK
)),
2696 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
2697 K(zone_page_state(zone
, NR_WRITEBACK
)),
2698 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
2699 K(zone_page_state(zone
, NR_SHMEM
)),
2700 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
2701 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
2702 zone_page_state(zone
, NR_KERNEL_STACK
) *
2704 K(zone_page_state(zone
, NR_PAGETABLE
)),
2705 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
2706 K(zone_page_state(zone
, NR_BOUNCE
)),
2707 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
2708 zone
->pages_scanned
,
2709 (zone
->all_unreclaimable
? "yes" : "no")
2711 printk("lowmem_reserve[]:");
2712 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
2713 printk(" %lu", zone
->lowmem_reserve
[i
]);
2717 for_each_populated_zone(zone
) {
2718 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
2720 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
2723 printk("%s: ", zone
->name
);
2725 spin_lock_irqsave(&zone
->lock
, flags
);
2726 for (order
= 0; order
< MAX_ORDER
; order
++) {
2727 nr
[order
] = zone
->free_area
[order
].nr_free
;
2728 total
+= nr
[order
] << order
;
2730 spin_unlock_irqrestore(&zone
->lock
, flags
);
2731 for (order
= 0; order
< MAX_ORDER
; order
++)
2732 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
2733 printk("= %lukB\n", K(total
));
2736 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
2738 show_swap_cache_info();
2741 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
2743 zoneref
->zone
= zone
;
2744 zoneref
->zone_idx
= zone_idx(zone
);
2748 * Builds allocation fallback zone lists.
2750 * Add all populated zones of a node to the zonelist.
2752 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
2753 int nr_zones
, enum zone_type zone_type
)
2757 BUG_ON(zone_type
>= MAX_NR_ZONES
);
2762 zone
= pgdat
->node_zones
+ zone_type
;
2763 if (populated_zone(zone
)) {
2764 zoneref_set_zone(zone
,
2765 &zonelist
->_zonerefs
[nr_zones
++]);
2766 check_highest_zone(zone_type
);
2769 } while (zone_type
);
2776 * 0 = automatic detection of better ordering.
2777 * 1 = order by ([node] distance, -zonetype)
2778 * 2 = order by (-zonetype, [node] distance)
2780 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
2781 * the same zonelist. So only NUMA can configure this param.
2783 #define ZONELIST_ORDER_DEFAULT 0
2784 #define ZONELIST_ORDER_NODE 1
2785 #define ZONELIST_ORDER_ZONE 2
2787 /* zonelist order in the kernel.
2788 * set_zonelist_order() will set this to NODE or ZONE.
2790 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2791 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
2795 /* The value user specified ....changed by config */
2796 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2797 /* string for sysctl */
2798 #define NUMA_ZONELIST_ORDER_LEN 16
2799 char numa_zonelist_order
[16] = "default";
2802 * interface for configure zonelist ordering.
2803 * command line option "numa_zonelist_order"
2804 * = "[dD]efault - default, automatic configuration.
2805 * = "[nN]ode - order by node locality, then by zone within node
2806 * = "[zZ]one - order by zone, then by locality within zone
2809 static int __parse_numa_zonelist_order(char *s
)
2811 if (*s
== 'd' || *s
== 'D') {
2812 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
2813 } else if (*s
== 'n' || *s
== 'N') {
2814 user_zonelist_order
= ZONELIST_ORDER_NODE
;
2815 } else if (*s
== 'z' || *s
== 'Z') {
2816 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
2819 "Ignoring invalid numa_zonelist_order value: "
2826 static __init
int setup_numa_zonelist_order(char *s
)
2833 ret
= __parse_numa_zonelist_order(s
);
2835 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
2839 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
2842 * sysctl handler for numa_zonelist_order
2844 int numa_zonelist_order_handler(ctl_table
*table
, int write
,
2845 void __user
*buffer
, size_t *length
,
2848 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
2850 static DEFINE_MUTEX(zl_order_mutex
);
2852 mutex_lock(&zl_order_mutex
);
2854 strcpy(saved_string
, (char*)table
->data
);
2855 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
2859 int oldval
= user_zonelist_order
;
2860 if (__parse_numa_zonelist_order((char*)table
->data
)) {
2862 * bogus value. restore saved string
2864 strncpy((char*)table
->data
, saved_string
,
2865 NUMA_ZONELIST_ORDER_LEN
);
2866 user_zonelist_order
= oldval
;
2867 } else if (oldval
!= user_zonelist_order
) {
2868 mutex_lock(&zonelists_mutex
);
2869 build_all_zonelists(NULL
);
2870 mutex_unlock(&zonelists_mutex
);
2874 mutex_unlock(&zl_order_mutex
);
2879 #define MAX_NODE_LOAD (nr_online_nodes)
2880 static int node_load
[MAX_NUMNODES
];
2883 * find_next_best_node - find the next node that should appear in a given node's fallback list
2884 * @node: node whose fallback list we're appending
2885 * @used_node_mask: nodemask_t of already used nodes
2887 * We use a number of factors to determine which is the next node that should
2888 * appear on a given node's fallback list. The node should not have appeared
2889 * already in @node's fallback list, and it should be the next closest node
2890 * according to the distance array (which contains arbitrary distance values
2891 * from each node to each node in the system), and should also prefer nodes
2892 * with no CPUs, since presumably they'll have very little allocation pressure
2893 * on them otherwise.
2894 * It returns -1 if no node is found.
2896 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
2899 int min_val
= INT_MAX
;
2901 const struct cpumask
*tmp
= cpumask_of_node(0);
2903 /* Use the local node if we haven't already */
2904 if (!node_isset(node
, *used_node_mask
)) {
2905 node_set(node
, *used_node_mask
);
2909 for_each_node_state(n
, N_HIGH_MEMORY
) {
2911 /* Don't want a node to appear more than once */
2912 if (node_isset(n
, *used_node_mask
))
2915 /* Use the distance array to find the distance */
2916 val
= node_distance(node
, n
);
2918 /* Penalize nodes under us ("prefer the next node") */
2921 /* Give preference to headless and unused nodes */
2922 tmp
= cpumask_of_node(n
);
2923 if (!cpumask_empty(tmp
))
2924 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
2926 /* Slight preference for less loaded node */
2927 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
2928 val
+= node_load
[n
];
2930 if (val
< min_val
) {
2937 node_set(best_node
, *used_node_mask
);
2944 * Build zonelists ordered by node and zones within node.
2945 * This results in maximum locality--normal zone overflows into local
2946 * DMA zone, if any--but risks exhausting DMA zone.
2948 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
2951 struct zonelist
*zonelist
;
2953 zonelist
= &pgdat
->node_zonelists
[0];
2954 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
2956 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
2958 zonelist
->_zonerefs
[j
].zone
= NULL
;
2959 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2963 * Build gfp_thisnode zonelists
2965 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
2968 struct zonelist
*zonelist
;
2970 zonelist
= &pgdat
->node_zonelists
[1];
2971 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
2972 zonelist
->_zonerefs
[j
].zone
= NULL
;
2973 zonelist
->_zonerefs
[j
].zone_idx
= 0;
2977 * Build zonelists ordered by zone and nodes within zones.
2978 * This results in conserving DMA zone[s] until all Normal memory is
2979 * exhausted, but results in overflowing to remote node while memory
2980 * may still exist in local DMA zone.
2982 static int node_order
[MAX_NUMNODES
];
2984 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
2987 int zone_type
; /* needs to be signed */
2989 struct zonelist
*zonelist
;
2991 zonelist
= &pgdat
->node_zonelists
[0];
2993 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
2994 for (j
= 0; j
< nr_nodes
; j
++) {
2995 node
= node_order
[j
];
2996 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
2997 if (populated_zone(z
)) {
2999 &zonelist
->_zonerefs
[pos
++]);
3000 check_highest_zone(zone_type
);
3004 zonelist
->_zonerefs
[pos
].zone
= NULL
;
3005 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
3008 static int default_zonelist_order(void)
3011 unsigned long low_kmem_size
,total_size
;
3015 * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
3016 * If they are really small and used heavily, the system can fall
3017 * into OOM very easily.
3018 * This function detect ZONE_DMA/DMA32 size and configures zone order.
3020 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
3023 for_each_online_node(nid
) {
3024 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
3025 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
3026 if (populated_zone(z
)) {
3027 if (zone_type
< ZONE_NORMAL
)
3028 low_kmem_size
+= z
->present_pages
;
3029 total_size
+= z
->present_pages
;
3030 } else if (zone_type
== ZONE_NORMAL
) {
3032 * If any node has only lowmem, then node order
3033 * is preferred to allow kernel allocations
3034 * locally; otherwise, they can easily infringe
3035 * on other nodes when there is an abundance of
3036 * lowmem available to allocate from.
3038 return ZONELIST_ORDER_NODE
;
3042 if (!low_kmem_size
|| /* there are no DMA area. */
3043 low_kmem_size
> total_size
/2) /* DMA/DMA32 is big. */
3044 return ZONELIST_ORDER_NODE
;
3046 * look into each node's config.
3047 * If there is a node whose DMA/DMA32 memory is very big area on
3048 * local memory, NODE_ORDER may be suitable.
3050 average_size
= total_size
/
3051 (nodes_weight(node_states
[N_HIGH_MEMORY
]) + 1);
3052 for_each_online_node(nid
) {
3055 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
3056 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
3057 if (populated_zone(z
)) {
3058 if (zone_type
< ZONE_NORMAL
)
3059 low_kmem_size
+= z
->present_pages
;
3060 total_size
+= z
->present_pages
;
3063 if (low_kmem_size
&&
3064 total_size
> average_size
&& /* ignore small node */
3065 low_kmem_size
> total_size
* 70/100)
3066 return ZONELIST_ORDER_NODE
;
3068 return ZONELIST_ORDER_ZONE
;
3071 static void set_zonelist_order(void)
3073 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
3074 current_zonelist_order
= default_zonelist_order();
3076 current_zonelist_order
= user_zonelist_order
;
3079 static void build_zonelists(pg_data_t
*pgdat
)
3083 nodemask_t used_mask
;
3084 int local_node
, prev_node
;
3085 struct zonelist
*zonelist
;
3086 int order
= current_zonelist_order
;
3088 /* initialize zonelists */
3089 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
3090 zonelist
= pgdat
->node_zonelists
+ i
;
3091 zonelist
->_zonerefs
[0].zone
= NULL
;
3092 zonelist
->_zonerefs
[0].zone_idx
= 0;
3095 /* NUMA-aware ordering of nodes */
3096 local_node
= pgdat
->node_id
;
3097 load
= nr_online_nodes
;
3098 prev_node
= local_node
;
3099 nodes_clear(used_mask
);
3101 memset(node_order
, 0, sizeof(node_order
));
3104 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
3105 int distance
= node_distance(local_node
, node
);
3108 * If another node is sufficiently far away then it is better
3109 * to reclaim pages in a zone before going off node.
3111 if (distance
> RECLAIM_DISTANCE
)
3112 zone_reclaim_mode
= 1;
3115 * We don't want to pressure a particular node.
3116 * So adding penalty to the first node in same
3117 * distance group to make it round-robin.
3119 if (distance
!= node_distance(local_node
, prev_node
))
3120 node_load
[node
] = load
;
3124 if (order
== ZONELIST_ORDER_NODE
)
3125 build_zonelists_in_node_order(pgdat
, node
);
3127 node_order
[j
++] = node
; /* remember order */
3130 if (order
== ZONELIST_ORDER_ZONE
) {
3131 /* calculate node order -- i.e., DMA last! */
3132 build_zonelists_in_zone_order(pgdat
, j
);
3135 build_thisnode_zonelists(pgdat
);
3138 /* Construct the zonelist performance cache - see further mmzone.h */
3139 static void build_zonelist_cache(pg_data_t
*pgdat
)
3141 struct zonelist
*zonelist
;
3142 struct zonelist_cache
*zlc
;
3145 zonelist
= &pgdat
->node_zonelists
[0];
3146 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
3147 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
3148 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
3149 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
3152 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3154 * Return node id of node used for "local" allocations.
3155 * I.e., first node id of first zone in arg node's generic zonelist.
3156 * Used for initializing percpu 'numa_mem', which is used primarily
3157 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3159 int local_memory_node(int node
)
3163 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
3164 gfp_zone(GFP_KERNEL
),
3171 #else /* CONFIG_NUMA */
3173 static void set_zonelist_order(void)
3175 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
3178 static void build_zonelists(pg_data_t
*pgdat
)
3180 int node
, local_node
;
3182 struct zonelist
*zonelist
;
3184 local_node
= pgdat
->node_id
;
3186 zonelist
= &pgdat
->node_zonelists
[0];
3187 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
3190 * Now we build the zonelist so that it contains the zones
3191 * of all the other nodes.
3192 * We don't want to pressure a particular node, so when
3193 * building the zones for node N, we make sure that the
3194 * zones coming right after the local ones are those from
3195 * node N+1 (modulo N)
3197 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
3198 if (!node_online(node
))
3200 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3203 for (node
= 0; node
< local_node
; node
++) {
3204 if (!node_online(node
))
3206 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3210 zonelist
->_zonerefs
[j
].zone
= NULL
;
3211 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3214 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3215 static void build_zonelist_cache(pg_data_t
*pgdat
)
3217 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
3220 #endif /* CONFIG_NUMA */
3223 * Boot pageset table. One per cpu which is going to be used for all
3224 * zones and all nodes. The parameters will be set in such a way
3225 * that an item put on a list will immediately be handed over to
3226 * the buddy list. This is safe since pageset manipulation is done
3227 * with interrupts disabled.
3229 * The boot_pagesets must be kept even after bootup is complete for
3230 * unused processors and/or zones. They do play a role for bootstrapping
3231 * hotplugged processors.
3233 * zoneinfo_show() and maybe other functions do
3234 * not check if the processor is online before following the pageset pointer.
3235 * Other parts of the kernel may not check if the zone is available.
3237 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
3238 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
3239 static void setup_zone_pageset(struct zone
*zone
);
3242 * Global mutex to protect against size modification of zonelists
3243 * as well as to serialize pageset setup for the new populated zone.
3245 DEFINE_MUTEX(zonelists_mutex
);
3247 /* return values int ....just for stop_machine() */
3248 static __init_refok
int __build_all_zonelists(void *data
)
3254 memset(node_load
, 0, sizeof(node_load
));
3256 for_each_online_node(nid
) {
3257 pg_data_t
*pgdat
= NODE_DATA(nid
);
3259 build_zonelists(pgdat
);
3260 build_zonelist_cache(pgdat
);
3264 * Initialize the boot_pagesets that are going to be used
3265 * for bootstrapping processors. The real pagesets for
3266 * each zone will be allocated later when the per cpu
3267 * allocator is available.
3269 * boot_pagesets are used also for bootstrapping offline
3270 * cpus if the system is already booted because the pagesets
3271 * are needed to initialize allocators on a specific cpu too.
3272 * F.e. the percpu allocator needs the page allocator which
3273 * needs the percpu allocator in order to allocate its pagesets
3274 * (a chicken-egg dilemma).
3276 for_each_possible_cpu(cpu
) {
3277 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
3279 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3281 * We now know the "local memory node" for each node--
3282 * i.e., the node of the first zone in the generic zonelist.
3283 * Set up numa_mem percpu variable for on-line cpus. During
3284 * boot, only the boot cpu should be on-line; we'll init the
3285 * secondary cpus' numa_mem as they come on-line. During
3286 * node/memory hotplug, we'll fixup all on-line cpus.
3288 if (cpu_online(cpu
))
3289 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
3297 * Called with zonelists_mutex held always
3298 * unless system_state == SYSTEM_BOOTING.
3300 void __ref
build_all_zonelists(void *data
)
3302 set_zonelist_order();
3304 if (system_state
== SYSTEM_BOOTING
) {
3305 __build_all_zonelists(NULL
);
3306 mminit_verify_zonelist();
3307 cpuset_init_current_mems_allowed();
3309 /* we have to stop all cpus to guarantee there is no user
3311 #ifdef CONFIG_MEMORY_HOTPLUG
3313 setup_zone_pageset((struct zone
*)data
);
3315 stop_machine(__build_all_zonelists
, NULL
, NULL
);
3316 /* cpuset refresh routine should be here */
3318 vm_total_pages
= nr_free_pagecache_pages();
3320 * Disable grouping by mobility if the number of pages in the
3321 * system is too low to allow the mechanism to work. It would be
3322 * more accurate, but expensive to check per-zone. This check is
3323 * made on memory-hotadd so a system can start with mobility
3324 * disabled and enable it later
3326 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
3327 page_group_by_mobility_disabled
= 1;
3329 page_group_by_mobility_disabled
= 0;
3331 printk("Built %i zonelists in %s order, mobility grouping %s. "
3332 "Total pages: %ld\n",
3334 zonelist_order_name
[current_zonelist_order
],
3335 page_group_by_mobility_disabled
? "off" : "on",
3338 printk("Policy zone: %s\n", zone_names
[policy_zone
]);
3343 * Helper functions to size the waitqueue hash table.
3344 * Essentially these want to choose hash table sizes sufficiently
3345 * large so that collisions trying to wait on pages are rare.
3346 * But in fact, the number of active page waitqueues on typical
3347 * systems is ridiculously low, less than 200. So this is even
3348 * conservative, even though it seems large.
3350 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3351 * waitqueues, i.e. the size of the waitq table given the number of pages.
3353 #define PAGES_PER_WAITQUEUE 256
3355 #ifndef CONFIG_MEMORY_HOTPLUG
3356 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3358 unsigned long size
= 1;
3360 pages
/= PAGES_PER_WAITQUEUE
;
3362 while (size
< pages
)
3366 * Once we have dozens or even hundreds of threads sleeping
3367 * on IO we've got bigger problems than wait queue collision.
3368 * Limit the size of the wait table to a reasonable size.
3370 size
= min(size
, 4096UL);
3372 return max(size
, 4UL);
3376 * A zone's size might be changed by hot-add, so it is not possible to determine
3377 * a suitable size for its wait_table. So we use the maximum size now.
3379 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
3381 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
3382 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3383 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
3385 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3386 * or more by the traditional way. (See above). It equals:
3388 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
3389 * ia64(16K page size) : = ( 8G + 4M)byte.
3390 * powerpc (64K page size) : = (32G +16M)byte.
3392 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3399 * This is an integer logarithm so that shifts can be used later
3400 * to extract the more random high bits from the multiplicative
3401 * hash function before the remainder is taken.
3403 static inline unsigned long wait_table_bits(unsigned long size
)
3408 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
3411 * Check if a pageblock contains reserved pages
3413 static int pageblock_is_reserved(unsigned long start_pfn
, unsigned long end_pfn
)
3417 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
3418 if (!pfn_valid_within(pfn
) || PageReserved(pfn_to_page(pfn
)))
3425 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3426 * of blocks reserved is based on min_wmark_pages(zone). The memory within
3427 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3428 * higher will lead to a bigger reserve which will get freed as contiguous
3429 * blocks as reclaim kicks in
3431 static void setup_zone_migrate_reserve(struct zone
*zone
)
3433 unsigned long start_pfn
, pfn
, end_pfn
, block_end_pfn
;
3435 unsigned long block_migratetype
;
3439 * Get the start pfn, end pfn and the number of blocks to reserve
3440 * We have to be careful to be aligned to pageblock_nr_pages to
3441 * make sure that we always check pfn_valid for the first page in
3444 start_pfn
= zone
->zone_start_pfn
;
3445 end_pfn
= start_pfn
+ zone
->spanned_pages
;
3446 start_pfn
= roundup(start_pfn
, pageblock_nr_pages
);
3447 reserve
= roundup(min_wmark_pages(zone
), pageblock_nr_pages
) >>
3451 * Reserve blocks are generally in place to help high-order atomic
3452 * allocations that are short-lived. A min_free_kbytes value that
3453 * would result in more than 2 reserve blocks for atomic allocations
3454 * is assumed to be in place to help anti-fragmentation for the
3455 * future allocation of hugepages at runtime.
3457 reserve
= min(2, reserve
);
3459 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
3460 if (!pfn_valid(pfn
))
3462 page
= pfn_to_page(pfn
);
3464 /* Watch out for overlapping nodes */
3465 if (page_to_nid(page
) != zone_to_nid(zone
))
3468 block_migratetype
= get_pageblock_migratetype(page
);
3470 /* Only test what is necessary when the reserves are not met */
3473 * Blocks with reserved pages will never free, skip
3476 block_end_pfn
= min(pfn
+ pageblock_nr_pages
, end_pfn
);
3477 if (pageblock_is_reserved(pfn
, block_end_pfn
))
3480 /* If this block is reserved, account for it */
3481 if (block_migratetype
== MIGRATE_RESERVE
) {
3486 /* Suitable for reserving if this block is movable */
3487 if (block_migratetype
== MIGRATE_MOVABLE
) {
3488 set_pageblock_migratetype(page
,
3490 move_freepages_block(zone
, page
,
3498 * If the reserve is met and this is a previous reserved block,
3501 if (block_migratetype
== MIGRATE_RESERVE
) {
3502 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3503 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
3509 * Initially all pages are reserved - free ones are freed
3510 * up by free_all_bootmem() once the early boot process is
3511 * done. Non-atomic initialization, single-pass.
3513 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
3514 unsigned long start_pfn
, enum memmap_context context
)
3517 unsigned long end_pfn
= start_pfn
+ size
;
3521 if (highest_memmap_pfn
< end_pfn
- 1)
3522 highest_memmap_pfn
= end_pfn
- 1;
3524 z
= &NODE_DATA(nid
)->node_zones
[zone
];
3525 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
3527 * There can be holes in boot-time mem_map[]s
3528 * handed to this function. They do not
3529 * exist on hotplugged memory.
3531 if (context
== MEMMAP_EARLY
) {
3532 if (!early_pfn_valid(pfn
))
3534 if (!early_pfn_in_nid(pfn
, nid
))
3537 page
= pfn_to_page(pfn
);
3538 set_page_links(page
, zone
, nid
, pfn
);
3539 mminit_verify_page_links(page
, zone
, nid
, pfn
);
3540 init_page_count(page
);
3541 reset_page_mapcount(page
);
3542 SetPageReserved(page
);
3544 * Mark the block movable so that blocks are reserved for
3545 * movable at startup. This will force kernel allocations
3546 * to reserve their blocks rather than leaking throughout
3547 * the address space during boot when many long-lived
3548 * kernel allocations are made. Later some blocks near
3549 * the start are marked MIGRATE_RESERVE by
3550 * setup_zone_migrate_reserve()
3552 * bitmap is created for zone's valid pfn range. but memmap
3553 * can be created for invalid pages (for alignment)
3554 * check here not to call set_pageblock_migratetype() against
3557 if ((z
->zone_start_pfn
<= pfn
)
3558 && (pfn
< z
->zone_start_pfn
+ z
->spanned_pages
)
3559 && !(pfn
& (pageblock_nr_pages
- 1)))
3560 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3562 INIT_LIST_HEAD(&page
->lru
);
3563 #ifdef WANT_PAGE_VIRTUAL
3564 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
3565 if (!is_highmem_idx(zone
))
3566 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
3571 static void __meminit
zone_init_free_lists(struct zone
*zone
)
3574 for_each_migratetype_order(order
, t
) {
3575 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
3576 zone
->free_area
[order
].nr_free
= 0;
3580 #ifndef __HAVE_ARCH_MEMMAP_INIT
3581 #define memmap_init(size, nid, zone, start_pfn) \
3582 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
3585 static int zone_batchsize(struct zone
*zone
)
3591 * The per-cpu-pages pools are set to around 1000th of the
3592 * size of the zone. But no more than 1/2 of a meg.
3594 * OK, so we don't know how big the cache is. So guess.
3596 batch
= zone
->present_pages
/ 1024;
3597 if (batch
* PAGE_SIZE
> 512 * 1024)
3598 batch
= (512 * 1024) / PAGE_SIZE
;
3599 batch
/= 4; /* We effectively *= 4 below */
3604 * Clamp the batch to a 2^n - 1 value. Having a power
3605 * of 2 value was found to be more likely to have
3606 * suboptimal cache aliasing properties in some cases.
3608 * For example if 2 tasks are alternately allocating
3609 * batches of pages, one task can end up with a lot
3610 * of pages of one half of the possible page colors
3611 * and the other with pages of the other colors.
3613 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
3618 /* The deferral and batching of frees should be suppressed under NOMMU
3621 * The problem is that NOMMU needs to be able to allocate large chunks
3622 * of contiguous memory as there's no hardware page translation to
3623 * assemble apparent contiguous memory from discontiguous pages.
3625 * Queueing large contiguous runs of pages for batching, however,
3626 * causes the pages to actually be freed in smaller chunks. As there
3627 * can be a significant delay between the individual batches being
3628 * recycled, this leads to the once large chunks of space being
3629 * fragmented and becoming unavailable for high-order allocations.
3635 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
3637 struct per_cpu_pages
*pcp
;
3640 memset(p
, 0, sizeof(*p
));
3644 pcp
->high
= 6 * batch
;
3645 pcp
->batch
= max(1UL, 1 * batch
);
3646 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
3647 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
3651 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
3652 * to the value high for the pageset p.
3655 static void setup_pagelist_highmark(struct per_cpu_pageset
*p
,
3658 struct per_cpu_pages
*pcp
;
3662 pcp
->batch
= max(1UL, high
/4);
3663 if ((high
/4) > (PAGE_SHIFT
* 8))
3664 pcp
->batch
= PAGE_SHIFT
* 8;
3667 static void setup_zone_pageset(struct zone
*zone
)
3671 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
3673 for_each_possible_cpu(cpu
) {
3674 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
3676 setup_pageset(pcp
, zone_batchsize(zone
));
3678 if (percpu_pagelist_fraction
)
3679 setup_pagelist_highmark(pcp
,
3680 (zone
->present_pages
/
3681 percpu_pagelist_fraction
));
3686 * Allocate per cpu pagesets and initialize them.
3687 * Before this call only boot pagesets were available.
3689 void __init
setup_per_cpu_pageset(void)
3693 for_each_populated_zone(zone
)
3694 setup_zone_pageset(zone
);
3697 static noinline __init_refok
3698 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
3701 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
3705 * The per-page waitqueue mechanism uses hashed waitqueues
3708 zone
->wait_table_hash_nr_entries
=
3709 wait_table_hash_nr_entries(zone_size_pages
);
3710 zone
->wait_table_bits
=
3711 wait_table_bits(zone
->wait_table_hash_nr_entries
);
3712 alloc_size
= zone
->wait_table_hash_nr_entries
3713 * sizeof(wait_queue_head_t
);
3715 if (!slab_is_available()) {
3716 zone
->wait_table
= (wait_queue_head_t
*)
3717 alloc_bootmem_node_nopanic(pgdat
, alloc_size
);
3720 * This case means that a zone whose size was 0 gets new memory
3721 * via memory hot-add.
3722 * But it may be the case that a new node was hot-added. In
3723 * this case vmalloc() will not be able to use this new node's
3724 * memory - this wait_table must be initialized to use this new
3725 * node itself as well.
3726 * To use this new node's memory, further consideration will be
3729 zone
->wait_table
= vmalloc(alloc_size
);
3731 if (!zone
->wait_table
)
3734 for(i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
3735 init_waitqueue_head(zone
->wait_table
+ i
);
3740 static int __zone_pcp_update(void *data
)
3742 struct zone
*zone
= data
;
3744 unsigned long batch
= zone_batchsize(zone
), flags
;
3746 for_each_possible_cpu(cpu
) {
3747 struct per_cpu_pageset
*pset
;
3748 struct per_cpu_pages
*pcp
;
3750 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
3753 local_irq_save(flags
);
3754 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
3755 setup_pageset(pset
, batch
);
3756 local_irq_restore(flags
);
3761 void zone_pcp_update(struct zone
*zone
)
3763 stop_machine(__zone_pcp_update
, zone
, NULL
);
3766 static __meminit
void zone_pcp_init(struct zone
*zone
)
3769 * per cpu subsystem is not up at this point. The following code
3770 * relies on the ability of the linker to provide the
3771 * offset of a (static) per cpu variable into the per cpu area.
3773 zone
->pageset
= &boot_pageset
;
3775 if (zone
->present_pages
)
3776 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
3777 zone
->name
, zone
->present_pages
,
3778 zone_batchsize(zone
));
3781 __meminit
int init_currently_empty_zone(struct zone
*zone
,
3782 unsigned long zone_start_pfn
,
3784 enum memmap_context context
)
3786 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
3788 ret
= zone_wait_table_init(zone
, size
);
3791 pgdat
->nr_zones
= zone_idx(zone
) + 1;
3793 zone
->zone_start_pfn
= zone_start_pfn
;
3795 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
3796 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
3798 (unsigned long)zone_idx(zone
),
3799 zone_start_pfn
, (zone_start_pfn
+ size
));
3801 zone_init_free_lists(zone
);
3806 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
3807 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
3809 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
3810 * Architectures may implement their own version but if add_active_range()
3811 * was used and there are no special requirements, this is a convenient
3814 int __meminit
__early_pfn_to_nid(unsigned long pfn
)
3816 unsigned long start_pfn
, end_pfn
;
3819 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
3820 if (start_pfn
<= pfn
&& pfn
< end_pfn
)
3822 /* This is a memory hole */
3825 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
3827 int __meminit
early_pfn_to_nid(unsigned long pfn
)
3831 nid
= __early_pfn_to_nid(pfn
);
3834 /* just returns 0 */
3838 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
3839 bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
3843 nid
= __early_pfn_to_nid(pfn
);
3844 if (nid
>= 0 && nid
!= node
)
3851 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
3852 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
3853 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
3855 * If an architecture guarantees that all ranges registered with
3856 * add_active_ranges() contain no holes and may be freed, this
3857 * this function may be used instead of calling free_bootmem() manually.
3859 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
3861 unsigned long start_pfn
, end_pfn
;
3864 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
3865 start_pfn
= min(start_pfn
, max_low_pfn
);
3866 end_pfn
= min(end_pfn
, max_low_pfn
);
3868 if (start_pfn
< end_pfn
)
3869 free_bootmem_node(NODE_DATA(this_nid
),
3870 PFN_PHYS(start_pfn
),
3871 (end_pfn
- start_pfn
) << PAGE_SHIFT
);
3875 int __init
add_from_early_node_map(struct range
*range
, int az
,
3876 int nr_range
, int nid
)
3878 unsigned long start_pfn
, end_pfn
;
3881 /* need to go over early_node_map to find out good range for node */
3882 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
)
3883 nr_range
= add_range(range
, az
, nr_range
, start_pfn
, end_pfn
);
3888 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3889 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3891 * If an architecture guarantees that all ranges registered with
3892 * add_active_ranges() contain no holes and may be freed, this
3893 * function may be used instead of calling memory_present() manually.
3895 void __init
sparse_memory_present_with_active_regions(int nid
)
3897 unsigned long start_pfn
, end_pfn
;
3900 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
3901 memory_present(this_nid
, start_pfn
, end_pfn
);
3905 * get_pfn_range_for_nid - Return the start and end page frames for a node
3906 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
3907 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
3908 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
3910 * It returns the start and end page frame of a node based on information
3911 * provided by an arch calling add_active_range(). If called for a node
3912 * with no available memory, a warning is printed and the start and end
3915 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
3916 unsigned long *start_pfn
, unsigned long *end_pfn
)
3918 unsigned long this_start_pfn
, this_end_pfn
;
3924 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
3925 *start_pfn
= min(*start_pfn
, this_start_pfn
);
3926 *end_pfn
= max(*end_pfn
, this_end_pfn
);
3929 if (*start_pfn
== -1UL)
3934 * This finds a zone that can be used for ZONE_MOVABLE pages. The
3935 * assumption is made that zones within a node are ordered in monotonic
3936 * increasing memory addresses so that the "highest" populated zone is used
3938 static void __init
find_usable_zone_for_movable(void)
3941 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
3942 if (zone_index
== ZONE_MOVABLE
)
3945 if (arch_zone_highest_possible_pfn
[zone_index
] >
3946 arch_zone_lowest_possible_pfn
[zone_index
])
3950 VM_BUG_ON(zone_index
== -1);
3951 movable_zone
= zone_index
;
3955 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
3956 * because it is sized independent of architecture. Unlike the other zones,
3957 * the starting point for ZONE_MOVABLE is not fixed. It may be different
3958 * in each node depending on the size of each node and how evenly kernelcore
3959 * is distributed. This helper function adjusts the zone ranges
3960 * provided by the architecture for a given node by using the end of the
3961 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
3962 * zones within a node are in order of monotonic increases memory addresses
3964 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
3965 unsigned long zone_type
,
3966 unsigned long node_start_pfn
,
3967 unsigned long node_end_pfn
,
3968 unsigned long *zone_start_pfn
,
3969 unsigned long *zone_end_pfn
)
3971 /* Only adjust if ZONE_MOVABLE is on this node */
3972 if (zone_movable_pfn
[nid
]) {
3973 /* Size ZONE_MOVABLE */
3974 if (zone_type
== ZONE_MOVABLE
) {
3975 *zone_start_pfn
= zone_movable_pfn
[nid
];
3976 *zone_end_pfn
= min(node_end_pfn
,
3977 arch_zone_highest_possible_pfn
[movable_zone
]);
3979 /* Adjust for ZONE_MOVABLE starting within this range */
3980 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
3981 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
3982 *zone_end_pfn
= zone_movable_pfn
[nid
];
3984 /* Check if this whole range is within ZONE_MOVABLE */
3985 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
3986 *zone_start_pfn
= *zone_end_pfn
;
3991 * Return the number of pages a zone spans in a node, including holes
3992 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
3994 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
3995 unsigned long zone_type
,
3996 unsigned long *ignored
)
3998 unsigned long node_start_pfn
, node_end_pfn
;
3999 unsigned long zone_start_pfn
, zone_end_pfn
;
4001 /* Get the start and end of the node and zone */
4002 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
4003 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
4004 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
4005 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4006 node_start_pfn
, node_end_pfn
,
4007 &zone_start_pfn
, &zone_end_pfn
);
4009 /* Check that this node has pages within the zone's required range */
4010 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
4013 /* Move the zone boundaries inside the node if necessary */
4014 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
4015 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
4017 /* Return the spanned pages */
4018 return zone_end_pfn
- zone_start_pfn
;
4022 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4023 * then all holes in the requested range will be accounted for.
4025 unsigned long __meminit
__absent_pages_in_range(int nid
,
4026 unsigned long range_start_pfn
,
4027 unsigned long range_end_pfn
)
4029 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
4030 unsigned long start_pfn
, end_pfn
;
4033 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
4034 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
4035 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
4036 nr_absent
-= end_pfn
- start_pfn
;
4042 * absent_pages_in_range - Return number of page frames in holes within a range
4043 * @start_pfn: The start PFN to start searching for holes
4044 * @end_pfn: The end PFN to stop searching for holes
4046 * It returns the number of pages frames in memory holes within a range.
4048 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
4049 unsigned long end_pfn
)
4051 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
4054 /* Return the number of page frames in holes in a zone on a node */
4055 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4056 unsigned long zone_type
,
4057 unsigned long *ignored
)
4059 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
4060 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
4061 unsigned long node_start_pfn
, node_end_pfn
;
4062 unsigned long zone_start_pfn
, zone_end_pfn
;
4064 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
4065 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
4066 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
4068 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4069 node_start_pfn
, node_end_pfn
,
4070 &zone_start_pfn
, &zone_end_pfn
);
4071 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
4074 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4075 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4076 unsigned long zone_type
,
4077 unsigned long *zones_size
)
4079 return zones_size
[zone_type
];
4082 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4083 unsigned long zone_type
,
4084 unsigned long *zholes_size
)
4089 return zholes_size
[zone_type
];
4092 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4094 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
4095 unsigned long *zones_size
, unsigned long *zholes_size
)
4097 unsigned long realtotalpages
, totalpages
= 0;
4100 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4101 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
4103 pgdat
->node_spanned_pages
= totalpages
;
4105 realtotalpages
= totalpages
;
4106 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4108 zone_absent_pages_in_node(pgdat
->node_id
, i
,
4110 pgdat
->node_present_pages
= realtotalpages
;
4111 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
4115 #ifndef CONFIG_SPARSEMEM
4117 * Calculate the size of the zone->blockflags rounded to an unsigned long
4118 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4119 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4120 * round what is now in bits to nearest long in bits, then return it in
4123 static unsigned long __init
usemap_size(unsigned long zonesize
)
4125 unsigned long usemapsize
;
4127 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
4128 usemapsize
= usemapsize
>> pageblock_order
;
4129 usemapsize
*= NR_PAGEBLOCK_BITS
;
4130 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
4132 return usemapsize
/ 8;
4135 static void __init
setup_usemap(struct pglist_data
*pgdat
,
4136 struct zone
*zone
, unsigned long zonesize
)
4138 unsigned long usemapsize
= usemap_size(zonesize
);
4139 zone
->pageblock_flags
= NULL
;
4141 zone
->pageblock_flags
= alloc_bootmem_node_nopanic(pgdat
,
4145 static inline void setup_usemap(struct pglist_data
*pgdat
,
4146 struct zone
*zone
, unsigned long zonesize
) {}
4147 #endif /* CONFIG_SPARSEMEM */
4149 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4151 /* Return a sensible default order for the pageblock size. */
4152 static inline int pageblock_default_order(void)
4154 if (HPAGE_SHIFT
> PAGE_SHIFT
)
4155 return HUGETLB_PAGE_ORDER
;
4160 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4161 static inline void __init
set_pageblock_order(unsigned int order
)
4163 /* Check that pageblock_nr_pages has not already been setup */
4164 if (pageblock_order
)
4168 * Assume the largest contiguous order of interest is a huge page.
4169 * This value may be variable depending on boot parameters on IA64
4171 pageblock_order
= order
;
4173 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4176 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4177 * and pageblock_default_order() are unused as pageblock_order is set
4178 * at compile-time. See include/linux/pageblock-flags.h for the values of
4179 * pageblock_order based on the kernel config
4181 static inline int pageblock_default_order(unsigned int order
)
4185 #define set_pageblock_order(x) do {} while (0)
4187 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4190 * Set up the zone data structures:
4191 * - mark all pages reserved
4192 * - mark all memory queues empty
4193 * - clear the memory bitmaps
4195 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
,
4196 unsigned long *zones_size
, unsigned long *zholes_size
)
4199 int nid
= pgdat
->node_id
;
4200 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
4203 pgdat_resize_init(pgdat
);
4204 pgdat
->nr_zones
= 0;
4205 init_waitqueue_head(&pgdat
->kswapd_wait
);
4206 pgdat
->kswapd_max_order
= 0;
4207 pgdat_page_cgroup_init(pgdat
);
4209 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4210 struct zone
*zone
= pgdat
->node_zones
+ j
;
4211 unsigned long size
, realsize
, memmap_pages
;
4214 size
= zone_spanned_pages_in_node(nid
, j
, zones_size
);
4215 realsize
= size
- zone_absent_pages_in_node(nid
, j
,
4219 * Adjust realsize so that it accounts for how much memory
4220 * is used by this zone for memmap. This affects the watermark
4221 * and per-cpu initialisations
4224 PAGE_ALIGN(size
* sizeof(struct page
)) >> PAGE_SHIFT
;
4225 if (realsize
>= memmap_pages
) {
4226 realsize
-= memmap_pages
;
4229 " %s zone: %lu pages used for memmap\n",
4230 zone_names
[j
], memmap_pages
);
4233 " %s zone: %lu pages exceeds realsize %lu\n",
4234 zone_names
[j
], memmap_pages
, realsize
);
4236 /* Account for reserved pages */
4237 if (j
== 0 && realsize
> dma_reserve
) {
4238 realsize
-= dma_reserve
;
4239 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
4240 zone_names
[0], dma_reserve
);
4243 if (!is_highmem_idx(j
))
4244 nr_kernel_pages
+= realsize
;
4245 nr_all_pages
+= realsize
;
4247 zone
->spanned_pages
= size
;
4248 zone
->present_pages
= realsize
;
4251 zone
->min_unmapped_pages
= (realsize
*sysctl_min_unmapped_ratio
)
4253 zone
->min_slab_pages
= (realsize
* sysctl_min_slab_ratio
) / 100;
4255 zone
->name
= zone_names
[j
];
4256 spin_lock_init(&zone
->lock
);
4257 spin_lock_init(&zone
->lru_lock
);
4258 zone_seqlock_init(zone
);
4259 zone
->zone_pgdat
= pgdat
;
4261 zone_pcp_init(zone
);
4263 INIT_LIST_HEAD(&zone
->lru
[l
].list
);
4264 zone
->reclaim_stat
.recent_rotated
[0] = 0;
4265 zone
->reclaim_stat
.recent_rotated
[1] = 0;
4266 zone
->reclaim_stat
.recent_scanned
[0] = 0;
4267 zone
->reclaim_stat
.recent_scanned
[1] = 0;
4268 zap_zone_vm_stats(zone
);
4273 set_pageblock_order(pageblock_default_order());
4274 setup_usemap(pgdat
, zone
, size
);
4275 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
4276 size
, MEMMAP_EARLY
);
4278 memmap_init(size
, nid
, j
, zone_start_pfn
);
4279 zone_start_pfn
+= size
;
4283 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
4285 /* Skip empty nodes */
4286 if (!pgdat
->node_spanned_pages
)
4289 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4290 /* ia64 gets its own node_mem_map, before this, without bootmem */
4291 if (!pgdat
->node_mem_map
) {
4292 unsigned long size
, start
, end
;
4296 * The zone's endpoints aren't required to be MAX_ORDER
4297 * aligned but the node_mem_map endpoints must be in order
4298 * for the buddy allocator to function correctly.
4300 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
4301 end
= pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
4302 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
4303 size
= (end
- start
) * sizeof(struct page
);
4304 map
= alloc_remap(pgdat
->node_id
, size
);
4306 map
= alloc_bootmem_node_nopanic(pgdat
, size
);
4307 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
4309 #ifndef CONFIG_NEED_MULTIPLE_NODES
4311 * With no DISCONTIG, the global mem_map is just set as node 0's
4313 if (pgdat
== NODE_DATA(0)) {
4314 mem_map
= NODE_DATA(0)->node_mem_map
;
4315 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4316 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
4317 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
4318 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4321 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4324 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
4325 unsigned long node_start_pfn
, unsigned long *zholes_size
)
4327 pg_data_t
*pgdat
= NODE_DATA(nid
);
4329 pgdat
->node_id
= nid
;
4330 pgdat
->node_start_pfn
= node_start_pfn
;
4331 calculate_node_totalpages(pgdat
, zones_size
, zholes_size
);
4333 alloc_node_mem_map(pgdat
);
4334 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4335 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
4336 nid
, (unsigned long)pgdat
,
4337 (unsigned long)pgdat
->node_mem_map
);
4340 free_area_init_core(pgdat
, zones_size
, zholes_size
);
4343 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4345 #if MAX_NUMNODES > 1
4347 * Figure out the number of possible node ids.
4349 static void __init
setup_nr_node_ids(void)
4352 unsigned int highest
= 0;
4354 for_each_node_mask(node
, node_possible_map
)
4356 nr_node_ids
= highest
+ 1;
4359 static inline void setup_nr_node_ids(void)
4365 * node_map_pfn_alignment - determine the maximum internode alignment
4367 * This function should be called after node map is populated and sorted.
4368 * It calculates the maximum power of two alignment which can distinguish
4371 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
4372 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
4373 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
4374 * shifted, 1GiB is enough and this function will indicate so.
4376 * This is used to test whether pfn -> nid mapping of the chosen memory
4377 * model has fine enough granularity to avoid incorrect mapping for the
4378 * populated node map.
4380 * Returns the determined alignment in pfn's. 0 if there is no alignment
4381 * requirement (single node).
4383 unsigned long __init
node_map_pfn_alignment(void)
4385 unsigned long accl_mask
= 0, last_end
= 0;
4386 unsigned long start
, end
, mask
;
4390 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
4391 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
4398 * Start with a mask granular enough to pin-point to the
4399 * start pfn and tick off bits one-by-one until it becomes
4400 * too coarse to separate the current node from the last.
4402 mask
= ~((1 << __ffs(start
)) - 1);
4403 while (mask
&& last_end
<= (start
& (mask
<< 1)))
4406 /* accumulate all internode masks */
4410 /* convert mask to number of pages */
4411 return ~accl_mask
+ 1;
4414 /* Find the lowest pfn for a node */
4415 static unsigned long __init
find_min_pfn_for_node(int nid
)
4417 unsigned long min_pfn
= ULONG_MAX
;
4418 unsigned long start_pfn
;
4421 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
4422 min_pfn
= min(min_pfn
, start_pfn
);
4424 if (min_pfn
== ULONG_MAX
) {
4426 "Could not find start_pfn for node %d\n", nid
);
4434 * find_min_pfn_with_active_regions - Find the minimum PFN registered
4436 * It returns the minimum PFN based on information provided via
4437 * add_active_range().
4439 unsigned long __init
find_min_pfn_with_active_regions(void)
4441 return find_min_pfn_for_node(MAX_NUMNODES
);
4445 * early_calculate_totalpages()
4446 * Sum pages in active regions for movable zone.
4447 * Populate N_HIGH_MEMORY for calculating usable_nodes.
4449 static unsigned long __init
early_calculate_totalpages(void)
4451 unsigned long totalpages
= 0;
4452 unsigned long start_pfn
, end_pfn
;
4455 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
4456 unsigned long pages
= end_pfn
- start_pfn
;
4458 totalpages
+= pages
;
4460 node_set_state(nid
, N_HIGH_MEMORY
);
4466 * Find the PFN the Movable zone begins in each node. Kernel memory
4467 * is spread evenly between nodes as long as the nodes have enough
4468 * memory. When they don't, some nodes will have more kernelcore than
4471 static void __init
find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn
)
4474 unsigned long usable_startpfn
;
4475 unsigned long kernelcore_node
, kernelcore_remaining
;
4476 /* save the state before borrow the nodemask */
4477 nodemask_t saved_node_state
= node_states
[N_HIGH_MEMORY
];
4478 unsigned long totalpages
= early_calculate_totalpages();
4479 int usable_nodes
= nodes_weight(node_states
[N_HIGH_MEMORY
]);
4482 * If movablecore was specified, calculate what size of
4483 * kernelcore that corresponds so that memory usable for
4484 * any allocation type is evenly spread. If both kernelcore
4485 * and movablecore are specified, then the value of kernelcore
4486 * will be used for required_kernelcore if it's greater than
4487 * what movablecore would have allowed.
4489 if (required_movablecore
) {
4490 unsigned long corepages
;
4493 * Round-up so that ZONE_MOVABLE is at least as large as what
4494 * was requested by the user
4496 required_movablecore
=
4497 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
4498 corepages
= totalpages
- required_movablecore
;
4500 required_kernelcore
= max(required_kernelcore
, corepages
);
4503 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
4504 if (!required_kernelcore
)
4507 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
4508 find_usable_zone_for_movable();
4509 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
4512 /* Spread kernelcore memory as evenly as possible throughout nodes */
4513 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4514 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4515 unsigned long start_pfn
, end_pfn
;
4518 * Recalculate kernelcore_node if the division per node
4519 * now exceeds what is necessary to satisfy the requested
4520 * amount of memory for the kernel
4522 if (required_kernelcore
< kernelcore_node
)
4523 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4526 * As the map is walked, we track how much memory is usable
4527 * by the kernel using kernelcore_remaining. When it is
4528 * 0, the rest of the node is usable by ZONE_MOVABLE
4530 kernelcore_remaining
= kernelcore_node
;
4532 /* Go through each range of PFNs within this node */
4533 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
4534 unsigned long size_pages
;
4536 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
4537 if (start_pfn
>= end_pfn
)
4540 /* Account for what is only usable for kernelcore */
4541 if (start_pfn
< usable_startpfn
) {
4542 unsigned long kernel_pages
;
4543 kernel_pages
= min(end_pfn
, usable_startpfn
)
4546 kernelcore_remaining
-= min(kernel_pages
,
4547 kernelcore_remaining
);
4548 required_kernelcore
-= min(kernel_pages
,
4549 required_kernelcore
);
4551 /* Continue if range is now fully accounted */
4552 if (end_pfn
<= usable_startpfn
) {
4555 * Push zone_movable_pfn to the end so
4556 * that if we have to rebalance
4557 * kernelcore across nodes, we will
4558 * not double account here
4560 zone_movable_pfn
[nid
] = end_pfn
;
4563 start_pfn
= usable_startpfn
;
4567 * The usable PFN range for ZONE_MOVABLE is from
4568 * start_pfn->end_pfn. Calculate size_pages as the
4569 * number of pages used as kernelcore
4571 size_pages
= end_pfn
- start_pfn
;
4572 if (size_pages
> kernelcore_remaining
)
4573 size_pages
= kernelcore_remaining
;
4574 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
4577 * Some kernelcore has been met, update counts and
4578 * break if the kernelcore for this node has been
4581 required_kernelcore
-= min(required_kernelcore
,
4583 kernelcore_remaining
-= size_pages
;
4584 if (!kernelcore_remaining
)
4590 * If there is still required_kernelcore, we do another pass with one
4591 * less node in the count. This will push zone_movable_pfn[nid] further
4592 * along on the nodes that still have memory until kernelcore is
4596 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
4599 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
4600 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
4601 zone_movable_pfn
[nid
] =
4602 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
4605 /* restore the node_state */
4606 node_states
[N_HIGH_MEMORY
] = saved_node_state
;
4609 /* Any regular memory on that node ? */
4610 static void check_for_regular_memory(pg_data_t
*pgdat
)
4612 #ifdef CONFIG_HIGHMEM
4613 enum zone_type zone_type
;
4615 for (zone_type
= 0; zone_type
<= ZONE_NORMAL
; zone_type
++) {
4616 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4617 if (zone
->present_pages
)
4618 node_set_state(zone_to_nid(zone
), N_NORMAL_MEMORY
);
4624 * free_area_init_nodes - Initialise all pg_data_t and zone data
4625 * @max_zone_pfn: an array of max PFNs for each zone
4627 * This will call free_area_init_node() for each active node in the system.
4628 * Using the page ranges provided by add_active_range(), the size of each
4629 * zone in each node and their holes is calculated. If the maximum PFN
4630 * between two adjacent zones match, it is assumed that the zone is empty.
4631 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
4632 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
4633 * starts where the previous one ended. For example, ZONE_DMA32 starts
4634 * at arch_max_dma_pfn.
4636 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
4638 unsigned long start_pfn
, end_pfn
;
4641 /* Record where the zone boundaries are */
4642 memset(arch_zone_lowest_possible_pfn
, 0,
4643 sizeof(arch_zone_lowest_possible_pfn
));
4644 memset(arch_zone_highest_possible_pfn
, 0,
4645 sizeof(arch_zone_highest_possible_pfn
));
4646 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
4647 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
4648 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
4649 if (i
== ZONE_MOVABLE
)
4651 arch_zone_lowest_possible_pfn
[i
] =
4652 arch_zone_highest_possible_pfn
[i
-1];
4653 arch_zone_highest_possible_pfn
[i
] =
4654 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
4656 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
4657 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
4659 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
4660 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
4661 find_zone_movable_pfns_for_nodes(zone_movable_pfn
);
4663 /* Print out the zone ranges */
4664 printk("Zone PFN ranges:\n");
4665 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4666 if (i
== ZONE_MOVABLE
)
4668 printk(" %-8s ", zone_names
[i
]);
4669 if (arch_zone_lowest_possible_pfn
[i
] ==
4670 arch_zone_highest_possible_pfn
[i
])
4673 printk("%0#10lx -> %0#10lx\n",
4674 arch_zone_lowest_possible_pfn
[i
],
4675 arch_zone_highest_possible_pfn
[i
]);
4678 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
4679 printk("Movable zone start PFN for each node\n");
4680 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
4681 if (zone_movable_pfn
[i
])
4682 printk(" Node %d: %lu\n", i
, zone_movable_pfn
[i
]);
4685 /* Print out the early_node_map[] */
4686 printk("Early memory PFN ranges\n");
4687 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
4688 printk(" %3d: %0#10lx -> %0#10lx\n", nid
, start_pfn
, end_pfn
);
4690 /* Initialise every node */
4691 mminit_verify_pageflags_layout();
4692 setup_nr_node_ids();
4693 for_each_online_node(nid
) {
4694 pg_data_t
*pgdat
= NODE_DATA(nid
);
4695 free_area_init_node(nid
, NULL
,
4696 find_min_pfn_for_node(nid
), NULL
);
4698 /* Any memory on that node */
4699 if (pgdat
->node_present_pages
)
4700 node_set_state(nid
, N_HIGH_MEMORY
);
4701 check_for_regular_memory(pgdat
);
4705 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
4707 unsigned long long coremem
;
4711 coremem
= memparse(p
, &p
);
4712 *core
= coremem
>> PAGE_SHIFT
;
4714 /* Paranoid check that UL is enough for the coremem value */
4715 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
4721 * kernelcore=size sets the amount of memory for use for allocations that
4722 * cannot be reclaimed or migrated.
4724 static int __init
cmdline_parse_kernelcore(char *p
)
4726 return cmdline_parse_core(p
, &required_kernelcore
);
4730 * movablecore=size sets the amount of memory for use for allocations that
4731 * can be reclaimed or migrated.
4733 static int __init
cmdline_parse_movablecore(char *p
)
4735 return cmdline_parse_core(p
, &required_movablecore
);
4738 early_param("kernelcore", cmdline_parse_kernelcore
);
4739 early_param("movablecore", cmdline_parse_movablecore
);
4741 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4744 * set_dma_reserve - set the specified number of pages reserved in the first zone
4745 * @new_dma_reserve: The number of pages to mark reserved
4747 * The per-cpu batchsize and zone watermarks are determined by present_pages.
4748 * In the DMA zone, a significant percentage may be consumed by kernel image
4749 * and other unfreeable allocations which can skew the watermarks badly. This
4750 * function may optionally be used to account for unfreeable pages in the
4751 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
4752 * smaller per-cpu batchsize.
4754 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
4756 dma_reserve
= new_dma_reserve
;
4759 void __init
free_area_init(unsigned long *zones_size
)
4761 free_area_init_node(0, zones_size
,
4762 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
4765 static int page_alloc_cpu_notify(struct notifier_block
*self
,
4766 unsigned long action
, void *hcpu
)
4768 int cpu
= (unsigned long)hcpu
;
4770 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
4774 * Spill the event counters of the dead processor
4775 * into the current processors event counters.
4776 * This artificially elevates the count of the current
4779 vm_events_fold_cpu(cpu
);
4782 * Zero the differential counters of the dead processor
4783 * so that the vm statistics are consistent.
4785 * This is only okay since the processor is dead and cannot
4786 * race with what we are doing.
4788 refresh_cpu_vm_stats(cpu
);
4793 void __init
page_alloc_init(void)
4795 hotcpu_notifier(page_alloc_cpu_notify
, 0);
4799 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
4800 * or min_free_kbytes changes.
4802 static void calculate_totalreserve_pages(void)
4804 struct pglist_data
*pgdat
;
4805 unsigned long reserve_pages
= 0;
4806 enum zone_type i
, j
;
4808 for_each_online_pgdat(pgdat
) {
4809 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4810 struct zone
*zone
= pgdat
->node_zones
+ i
;
4811 unsigned long max
= 0;
4813 /* Find valid and maximum lowmem_reserve in the zone */
4814 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
4815 if (zone
->lowmem_reserve
[j
] > max
)
4816 max
= zone
->lowmem_reserve
[j
];
4819 /* we treat the high watermark as reserved pages. */
4820 max
+= high_wmark_pages(zone
);
4822 if (max
> zone
->present_pages
)
4823 max
= zone
->present_pages
;
4824 reserve_pages
+= max
;
4827 totalreserve_pages
= reserve_pages
;
4831 * setup_per_zone_lowmem_reserve - called whenever
4832 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
4833 * has a correct pages reserved value, so an adequate number of
4834 * pages are left in the zone after a successful __alloc_pages().
4836 static void setup_per_zone_lowmem_reserve(void)
4838 struct pglist_data
*pgdat
;
4839 enum zone_type j
, idx
;
4841 for_each_online_pgdat(pgdat
) {
4842 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4843 struct zone
*zone
= pgdat
->node_zones
+ j
;
4844 unsigned long present_pages
= zone
->present_pages
;
4846 zone
->lowmem_reserve
[j
] = 0;
4850 struct zone
*lower_zone
;
4854 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
4855 sysctl_lowmem_reserve_ratio
[idx
] = 1;
4857 lower_zone
= pgdat
->node_zones
+ idx
;
4858 lower_zone
->lowmem_reserve
[j
] = present_pages
/
4859 sysctl_lowmem_reserve_ratio
[idx
];
4860 present_pages
+= lower_zone
->present_pages
;
4865 /* update totalreserve_pages */
4866 calculate_totalreserve_pages();
4870 * setup_per_zone_wmarks - called when min_free_kbytes changes
4871 * or when memory is hot-{added|removed}
4873 * Ensures that the watermark[min,low,high] values for each zone are set
4874 * correctly with respect to min_free_kbytes.
4876 void setup_per_zone_wmarks(void)
4878 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
4879 unsigned long lowmem_pages
= 0;
4881 unsigned long flags
;
4883 /* Calculate total number of !ZONE_HIGHMEM pages */
4884 for_each_zone(zone
) {
4885 if (!is_highmem(zone
))
4886 lowmem_pages
+= zone
->present_pages
;
4889 for_each_zone(zone
) {
4892 spin_lock_irqsave(&zone
->lock
, flags
);
4893 tmp
= (u64
)pages_min
* zone
->present_pages
;
4894 do_div(tmp
, lowmem_pages
);
4895 if (is_highmem(zone
)) {
4897 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
4898 * need highmem pages, so cap pages_min to a small
4901 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
4902 * deltas controls asynch page reclaim, and so should
4903 * not be capped for highmem.
4907 min_pages
= zone
->present_pages
/ 1024;
4908 if (min_pages
< SWAP_CLUSTER_MAX
)
4909 min_pages
= SWAP_CLUSTER_MAX
;
4910 if (min_pages
> 128)
4912 zone
->watermark
[WMARK_MIN
] = min_pages
;
4915 * If it's a lowmem zone, reserve a number of pages
4916 * proportionate to the zone's size.
4918 zone
->watermark
[WMARK_MIN
] = tmp
;
4921 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + (tmp
>> 2);
4922 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + (tmp
>> 1);
4923 setup_zone_migrate_reserve(zone
);
4924 spin_unlock_irqrestore(&zone
->lock
, flags
);
4927 /* update totalreserve_pages */
4928 calculate_totalreserve_pages();
4932 * The inactive anon list should be small enough that the VM never has to
4933 * do too much work, but large enough that each inactive page has a chance
4934 * to be referenced again before it is swapped out.
4936 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
4937 * INACTIVE_ANON pages on this zone's LRU, maintained by the
4938 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
4939 * the anonymous pages are kept on the inactive list.
4942 * memory ratio inactive anon
4943 * -------------------------------------
4952 static void __meminit
calculate_zone_inactive_ratio(struct zone
*zone
)
4954 unsigned int gb
, ratio
;
4956 /* Zone size in gigabytes */
4957 gb
= zone
->present_pages
>> (30 - PAGE_SHIFT
);
4959 ratio
= int_sqrt(10 * gb
);
4963 zone
->inactive_ratio
= ratio
;
4966 static void __meminit
setup_per_zone_inactive_ratio(void)
4971 calculate_zone_inactive_ratio(zone
);
4975 * Initialise min_free_kbytes.
4977 * For small machines we want it small (128k min). For large machines
4978 * we want it large (64MB max). But it is not linear, because network
4979 * bandwidth does not increase linearly with machine size. We use
4981 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
4982 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
4998 int __meminit
init_per_zone_wmark_min(void)
5000 unsigned long lowmem_kbytes
;
5002 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
5004 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
5005 if (min_free_kbytes
< 128)
5006 min_free_kbytes
= 128;
5007 if (min_free_kbytes
> 65536)
5008 min_free_kbytes
= 65536;
5009 setup_per_zone_wmarks();
5010 refresh_zone_stat_thresholds();
5011 setup_per_zone_lowmem_reserve();
5012 setup_per_zone_inactive_ratio();
5015 module_init(init_per_zone_wmark_min
)
5018 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5019 * that we can call two helper functions whenever min_free_kbytes
5022 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
5023 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5025 proc_dointvec(table
, write
, buffer
, length
, ppos
);
5027 setup_per_zone_wmarks();
5032 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
5033 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5038 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5043 zone
->min_unmapped_pages
= (zone
->present_pages
*
5044 sysctl_min_unmapped_ratio
) / 100;
5048 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
5049 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5054 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5059 zone
->min_slab_pages
= (zone
->present_pages
*
5060 sysctl_min_slab_ratio
) / 100;
5066 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5067 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5068 * whenever sysctl_lowmem_reserve_ratio changes.
5070 * The reserve ratio obviously has absolutely no relation with the
5071 * minimum watermarks. The lowmem reserve ratio can only make sense
5072 * if in function of the boot time zone sizes.
5074 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
5075 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5077 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5078 setup_per_zone_lowmem_reserve();
5083 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5084 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
5085 * can have before it gets flushed back to buddy allocator.
5088 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
5089 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5095 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5096 if (!write
|| (ret
== -EINVAL
))
5098 for_each_populated_zone(zone
) {
5099 for_each_possible_cpu(cpu
) {
5101 high
= zone
->present_pages
/ percpu_pagelist_fraction
;
5102 setup_pagelist_highmark(
5103 per_cpu_ptr(zone
->pageset
, cpu
), high
);
5109 int hashdist
= HASHDIST_DEFAULT
;
5112 static int __init
set_hashdist(char *str
)
5116 hashdist
= simple_strtoul(str
, &str
, 0);
5119 __setup("hashdist=", set_hashdist
);
5123 * allocate a large system hash table from bootmem
5124 * - it is assumed that the hash table must contain an exact power-of-2
5125 * quantity of entries
5126 * - limit is the number of hash buckets, not the total allocation size
5128 void *__init
alloc_large_system_hash(const char *tablename
,
5129 unsigned long bucketsize
,
5130 unsigned long numentries
,
5133 unsigned int *_hash_shift
,
5134 unsigned int *_hash_mask
,
5135 unsigned long limit
)
5137 unsigned long long max
= limit
;
5138 unsigned long log2qty
, size
;
5141 /* allow the kernel cmdline to have a say */
5143 /* round applicable memory size up to nearest megabyte */
5144 numentries
= nr_kernel_pages
;
5145 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
5146 numentries
>>= 20 - PAGE_SHIFT
;
5147 numentries
<<= 20 - PAGE_SHIFT
;
5149 /* limit to 1 bucket per 2^scale bytes of low memory */
5150 if (scale
> PAGE_SHIFT
)
5151 numentries
>>= (scale
- PAGE_SHIFT
);
5153 numentries
<<= (PAGE_SHIFT
- scale
);
5155 /* Make sure we've got at least a 0-order allocation.. */
5156 if (unlikely(flags
& HASH_SMALL
)) {
5157 /* Makes no sense without HASH_EARLY */
5158 WARN_ON(!(flags
& HASH_EARLY
));
5159 if (!(numentries
>> *_hash_shift
)) {
5160 numentries
= 1UL << *_hash_shift
;
5161 BUG_ON(!numentries
);
5163 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
5164 numentries
= PAGE_SIZE
/ bucketsize
;
5166 numentries
= roundup_pow_of_two(numentries
);
5168 /* limit allocation size to 1/16 total memory by default */
5170 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
5171 do_div(max
, bucketsize
);
5174 if (numentries
> max
)
5177 log2qty
= ilog2(numentries
);
5180 size
= bucketsize
<< log2qty
;
5181 if (flags
& HASH_EARLY
)
5182 table
= alloc_bootmem_nopanic(size
);
5184 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
5187 * If bucketsize is not a power-of-two, we may free
5188 * some pages at the end of hash table which
5189 * alloc_pages_exact() automatically does
5191 if (get_order(size
) < MAX_ORDER
) {
5192 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
5193 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
5196 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
5199 panic("Failed to allocate %s hash table\n", tablename
);
5201 printk(KERN_INFO
"%s hash table entries: %ld (order: %d, %lu bytes)\n",
5204 ilog2(size
) - PAGE_SHIFT
,
5208 *_hash_shift
= log2qty
;
5210 *_hash_mask
= (1 << log2qty
) - 1;
5215 /* Return a pointer to the bitmap storing bits affecting a block of pages */
5216 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
5219 #ifdef CONFIG_SPARSEMEM
5220 return __pfn_to_section(pfn
)->pageblock_flags
;
5222 return zone
->pageblock_flags
;
5223 #endif /* CONFIG_SPARSEMEM */
5226 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
5228 #ifdef CONFIG_SPARSEMEM
5229 pfn
&= (PAGES_PER_SECTION
-1);
5230 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5232 pfn
= pfn
- zone
->zone_start_pfn
;
5233 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5234 #endif /* CONFIG_SPARSEMEM */
5238 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5239 * @page: The page within the block of interest
5240 * @start_bitidx: The first bit of interest to retrieve
5241 * @end_bitidx: The last bit of interest
5242 * returns pageblock_bits flags
5244 unsigned long get_pageblock_flags_group(struct page
*page
,
5245 int start_bitidx
, int end_bitidx
)
5248 unsigned long *bitmap
;
5249 unsigned long pfn
, bitidx
;
5250 unsigned long flags
= 0;
5251 unsigned long value
= 1;
5253 zone
= page_zone(page
);
5254 pfn
= page_to_pfn(page
);
5255 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5256 bitidx
= pfn_to_bitidx(zone
, pfn
);
5258 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5259 if (test_bit(bitidx
+ start_bitidx
, bitmap
))
5266 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5267 * @page: The page within the block of interest
5268 * @start_bitidx: The first bit of interest
5269 * @end_bitidx: The last bit of interest
5270 * @flags: The flags to set
5272 void set_pageblock_flags_group(struct page
*page
, unsigned long flags
,
5273 int start_bitidx
, int end_bitidx
)
5276 unsigned long *bitmap
;
5277 unsigned long pfn
, bitidx
;
5278 unsigned long value
= 1;
5280 zone
= page_zone(page
);
5281 pfn
= page_to_pfn(page
);
5282 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5283 bitidx
= pfn_to_bitidx(zone
, pfn
);
5284 VM_BUG_ON(pfn
< zone
->zone_start_pfn
);
5285 VM_BUG_ON(pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
);
5287 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5289 __set_bit(bitidx
+ start_bitidx
, bitmap
);
5291 __clear_bit(bitidx
+ start_bitidx
, bitmap
);
5295 * This is designed as sub function...plz see page_isolation.c also.
5296 * set/clear page block's type to be ISOLATE.
5297 * page allocater never alloc memory from ISOLATE block.
5301 __count_immobile_pages(struct zone
*zone
, struct page
*page
, int count
)
5303 unsigned long pfn
, iter
, found
;
5305 * For avoiding noise data, lru_add_drain_all() should be called
5306 * If ZONE_MOVABLE, the zone never contains immobile pages
5308 if (zone_idx(zone
) == ZONE_MOVABLE
)
5311 if (get_pageblock_migratetype(page
) == MIGRATE_MOVABLE
)
5314 pfn
= page_to_pfn(page
);
5315 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
5316 unsigned long check
= pfn
+ iter
;
5318 if (!pfn_valid_within(check
))
5321 page
= pfn_to_page(check
);
5322 if (!page_count(page
)) {
5323 if (PageBuddy(page
))
5324 iter
+= (1 << page_order(page
)) - 1;
5330 * If there are RECLAIMABLE pages, we need to check it.
5331 * But now, memory offline itself doesn't call shrink_slab()
5332 * and it still to be fixed.
5335 * If the page is not RAM, page_count()should be 0.
5336 * we don't need more check. This is an _used_ not-movable page.
5338 * The problematic thing here is PG_reserved pages. PG_reserved
5339 * is set to both of a memory hole page and a _used_ kernel
5348 bool is_pageblock_removable_nolock(struct page
*page
)
5350 struct zone
*zone
= page_zone(page
);
5351 return __count_immobile_pages(zone
, page
, 0);
5354 int set_migratetype_isolate(struct page
*page
)
5357 unsigned long flags
, pfn
;
5358 struct memory_isolate_notify arg
;
5362 zone
= page_zone(page
);
5364 spin_lock_irqsave(&zone
->lock
, flags
);
5366 pfn
= page_to_pfn(page
);
5367 arg
.start_pfn
= pfn
;
5368 arg
.nr_pages
= pageblock_nr_pages
;
5369 arg
.pages_found
= 0;
5372 * It may be possible to isolate a pageblock even if the
5373 * migratetype is not MIGRATE_MOVABLE. The memory isolation
5374 * notifier chain is used by balloon drivers to return the
5375 * number of pages in a range that are held by the balloon
5376 * driver to shrink memory. If all the pages are accounted for
5377 * by balloons, are free, or on the LRU, isolation can continue.
5378 * Later, for example, when memory hotplug notifier runs, these
5379 * pages reported as "can be isolated" should be isolated(freed)
5380 * by the balloon driver through the memory notifier chain.
5382 notifier_ret
= memory_isolate_notify(MEM_ISOLATE_COUNT
, &arg
);
5383 notifier_ret
= notifier_to_errno(notifier_ret
);
5387 * FIXME: Now, memory hotplug doesn't call shrink_slab() by itself.
5388 * We just check MOVABLE pages.
5390 if (__count_immobile_pages(zone
, page
, arg
.pages_found
))
5394 * immobile means "not-on-lru" paes. If immobile is larger than
5395 * removable-by-driver pages reported by notifier, we'll fail.
5400 set_pageblock_migratetype(page
, MIGRATE_ISOLATE
);
5401 move_freepages_block(zone
, page
, MIGRATE_ISOLATE
);
5404 spin_unlock_irqrestore(&zone
->lock
, flags
);
5410 void unset_migratetype_isolate(struct page
*page
)
5413 unsigned long flags
;
5414 zone
= page_zone(page
);
5415 spin_lock_irqsave(&zone
->lock
, flags
);
5416 if (get_pageblock_migratetype(page
) != MIGRATE_ISOLATE
)
5418 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
5419 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
5421 spin_unlock_irqrestore(&zone
->lock
, flags
);
5424 #ifdef CONFIG_MEMORY_HOTREMOVE
5426 * All pages in the range must be isolated before calling this.
5429 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
5435 unsigned long flags
;
5436 /* find the first valid pfn */
5437 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
5442 zone
= page_zone(pfn_to_page(pfn
));
5443 spin_lock_irqsave(&zone
->lock
, flags
);
5445 while (pfn
< end_pfn
) {
5446 if (!pfn_valid(pfn
)) {
5450 page
= pfn_to_page(pfn
);
5451 BUG_ON(page_count(page
));
5452 BUG_ON(!PageBuddy(page
));
5453 order
= page_order(page
);
5454 #ifdef CONFIG_DEBUG_VM
5455 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
5456 pfn
, 1 << order
, end_pfn
);
5458 list_del(&page
->lru
);
5459 rmv_page_order(page
);
5460 zone
->free_area
[order
].nr_free
--;
5461 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
5463 for (i
= 0; i
< (1 << order
); i
++)
5464 SetPageReserved((page
+i
));
5465 pfn
+= (1 << order
);
5467 spin_unlock_irqrestore(&zone
->lock
, flags
);
5471 #ifdef CONFIG_MEMORY_FAILURE
5472 bool is_free_buddy_page(struct page
*page
)
5474 struct zone
*zone
= page_zone(page
);
5475 unsigned long pfn
= page_to_pfn(page
);
5476 unsigned long flags
;
5479 spin_lock_irqsave(&zone
->lock
, flags
);
5480 for (order
= 0; order
< MAX_ORDER
; order
++) {
5481 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
5483 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
5486 spin_unlock_irqrestore(&zone
->lock
, flags
);
5488 return order
< MAX_ORDER
;
5492 static struct trace_print_flags pageflag_names
[] = {
5493 {1UL << PG_locked
, "locked" },
5494 {1UL << PG_error
, "error" },
5495 {1UL << PG_referenced
, "referenced" },
5496 {1UL << PG_uptodate
, "uptodate" },
5497 {1UL << PG_dirty
, "dirty" },
5498 {1UL << PG_lru
, "lru" },
5499 {1UL << PG_active
, "active" },
5500 {1UL << PG_slab
, "slab" },
5501 {1UL << PG_owner_priv_1
, "owner_priv_1" },
5502 {1UL << PG_arch_1
, "arch_1" },
5503 {1UL << PG_reserved
, "reserved" },
5504 {1UL << PG_private
, "private" },
5505 {1UL << PG_private_2
, "private_2" },
5506 {1UL << PG_writeback
, "writeback" },
5507 #ifdef CONFIG_PAGEFLAGS_EXTENDED
5508 {1UL << PG_head
, "head" },
5509 {1UL << PG_tail
, "tail" },
5511 {1UL << PG_compound
, "compound" },
5513 {1UL << PG_swapcache
, "swapcache" },
5514 {1UL << PG_mappedtodisk
, "mappedtodisk" },
5515 {1UL << PG_reclaim
, "reclaim" },
5516 {1UL << PG_swapbacked
, "swapbacked" },
5517 {1UL << PG_unevictable
, "unevictable" },
5519 {1UL << PG_mlocked
, "mlocked" },
5521 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
5522 {1UL << PG_uncached
, "uncached" },
5524 #ifdef CONFIG_MEMORY_FAILURE
5525 {1UL << PG_hwpoison
, "hwpoison" },
5530 static void dump_page_flags(unsigned long flags
)
5532 const char *delim
= "";
5536 printk(KERN_ALERT
"page flags: %#lx(", flags
);
5538 /* remove zone id */
5539 flags
&= (1UL << NR_PAGEFLAGS
) - 1;
5541 for (i
= 0; pageflag_names
[i
].name
&& flags
; i
++) {
5543 mask
= pageflag_names
[i
].mask
;
5544 if ((flags
& mask
) != mask
)
5548 printk("%s%s", delim
, pageflag_names
[i
].name
);
5552 /* check for left over flags */
5554 printk("%s%#lx", delim
, flags
);
5559 void dump_page(struct page
*page
)
5562 "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
5563 page
, atomic_read(&page
->_count
), page_mapcount(page
),
5564 page
->mapping
, page
->index
);
5565 dump_page_flags(page
->flags
);
5566 mem_cgroup_print_bad_page(page
);