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/compaction.h>
55 #include <trace/events/kmem.h>
56 #include <linux/ftrace_event.h>
57 #include <linux/memcontrol.h>
58 #include <linux/prefetch.h>
59 #include <linux/migrate.h>
60 #include <linux/page-debug-flags.h>
62 #include <asm/tlbflush.h>
63 #include <asm/div64.h>
66 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
67 DEFINE_PER_CPU(int, numa_node
);
68 EXPORT_PER_CPU_SYMBOL(numa_node
);
71 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
73 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
74 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
75 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
76 * defined in <linux/topology.h>.
78 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
79 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
83 * Array of node states.
85 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
86 [N_POSSIBLE
] = NODE_MASK_ALL
,
87 [N_ONLINE
] = { { [0] = 1UL } },
89 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
91 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
93 [N_CPU
] = { { [0] = 1UL } },
96 EXPORT_SYMBOL(node_states
);
98 unsigned long totalram_pages __read_mostly
;
99 unsigned long totalreserve_pages __read_mostly
;
101 * When calculating the number of globally allowed dirty pages, there
102 * is a certain number of per-zone reserves that should not be
103 * considered dirtyable memory. This is the sum of those reserves
104 * over all existing zones that contribute dirtyable memory.
106 unsigned long dirty_balance_reserve __read_mostly
;
108 int percpu_pagelist_fraction
;
109 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
111 #ifdef CONFIG_PM_SLEEP
113 * The following functions are used by the suspend/hibernate code to temporarily
114 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
115 * while devices are suspended. To avoid races with the suspend/hibernate code,
116 * they should always be called with pm_mutex held (gfp_allowed_mask also should
117 * only be modified with pm_mutex held, unless the suspend/hibernate code is
118 * guaranteed not to run in parallel with that modification).
121 static gfp_t saved_gfp_mask
;
123 void pm_restore_gfp_mask(void)
125 WARN_ON(!mutex_is_locked(&pm_mutex
));
126 if (saved_gfp_mask
) {
127 gfp_allowed_mask
= saved_gfp_mask
;
132 void pm_restrict_gfp_mask(void)
134 WARN_ON(!mutex_is_locked(&pm_mutex
));
135 WARN_ON(saved_gfp_mask
);
136 saved_gfp_mask
= gfp_allowed_mask
;
137 gfp_allowed_mask
&= ~GFP_IOFS
;
140 bool pm_suspended_storage(void)
142 if ((gfp_allowed_mask
& GFP_IOFS
) == GFP_IOFS
)
146 #endif /* CONFIG_PM_SLEEP */
148 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
149 int pageblock_order __read_mostly
;
152 static void __free_pages_ok(struct page
*page
, unsigned int order
);
155 * results with 256, 32 in the lowmem_reserve sysctl:
156 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
157 * 1G machine -> (16M dma, 784M normal, 224M high)
158 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
159 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
160 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
162 * TBD: should special case ZONE_DMA32 machines here - in those we normally
163 * don't need any ZONE_NORMAL reservation
165 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
166 #ifdef CONFIG_ZONE_DMA
169 #ifdef CONFIG_ZONE_DMA32
172 #ifdef CONFIG_HIGHMEM
178 EXPORT_SYMBOL(totalram_pages
);
180 static char * const zone_names
[MAX_NR_ZONES
] = {
181 #ifdef CONFIG_ZONE_DMA
184 #ifdef CONFIG_ZONE_DMA32
188 #ifdef CONFIG_HIGHMEM
194 int min_free_kbytes
= 1024;
196 static unsigned long __meminitdata nr_kernel_pages
;
197 static unsigned long __meminitdata nr_all_pages
;
198 static unsigned long __meminitdata dma_reserve
;
200 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
201 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
202 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
203 static unsigned long __initdata required_kernelcore
;
204 static unsigned long __initdata required_movablecore
;
205 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
207 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
209 EXPORT_SYMBOL(movable_zone
);
210 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
213 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
214 int nr_online_nodes __read_mostly
= 1;
215 EXPORT_SYMBOL(nr_node_ids
);
216 EXPORT_SYMBOL(nr_online_nodes
);
219 int page_group_by_mobility_disabled __read_mostly
;
223 * Don't use set_pageblock_migratetype(page, MIGRATE_ISOLATE) directly.
224 * Instead, use {un}set_pageblock_isolate.
226 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
229 if (unlikely(page_group_by_mobility_disabled
))
230 migratetype
= MIGRATE_UNMOVABLE
;
232 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
233 PB_migrate
, PB_migrate_end
);
236 bool oom_killer_disabled __read_mostly
;
238 #ifdef CONFIG_DEBUG_VM
239 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
243 unsigned long pfn
= page_to_pfn(page
);
246 seq
= zone_span_seqbegin(zone
);
247 if (pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
249 else if (pfn
< zone
->zone_start_pfn
)
251 } while (zone_span_seqretry(zone
, seq
));
256 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
258 if (!pfn_valid_within(page_to_pfn(page
)))
260 if (zone
!= page_zone(page
))
266 * Temporary debugging check for pages not lying within a given zone.
268 static int bad_range(struct zone
*zone
, struct page
*page
)
270 if (page_outside_zone_boundaries(zone
, page
))
272 if (!page_is_consistent(zone
, page
))
278 static inline int bad_range(struct zone
*zone
, struct page
*page
)
284 static void bad_page(struct page
*page
)
286 static unsigned long resume
;
287 static unsigned long nr_shown
;
288 static unsigned long nr_unshown
;
290 /* Don't complain about poisoned pages */
291 if (PageHWPoison(page
)) {
292 reset_page_mapcount(page
); /* remove PageBuddy */
297 * Allow a burst of 60 reports, then keep quiet for that minute;
298 * or allow a steady drip of one report per second.
300 if (nr_shown
== 60) {
301 if (time_before(jiffies
, resume
)) {
307 "BUG: Bad page state: %lu messages suppressed\n",
314 resume
= jiffies
+ 60 * HZ
;
316 printk(KERN_ALERT
"BUG: Bad page state in process %s pfn:%05lx\n",
317 current
->comm
, page_to_pfn(page
));
323 /* Leave bad fields for debug, except PageBuddy could make trouble */
324 reset_page_mapcount(page
); /* remove PageBuddy */
325 add_taint(TAINT_BAD_PAGE
);
329 * Higher-order pages are called "compound pages". They are structured thusly:
331 * The first PAGE_SIZE page is called the "head page".
333 * The remaining PAGE_SIZE pages are called "tail pages".
335 * All pages have PG_compound set. All tail pages have their ->first_page
336 * pointing at the head page.
338 * The first tail page's ->lru.next holds the address of the compound page's
339 * put_page() function. Its ->lru.prev holds the order of allocation.
340 * This usage means that zero-order pages may not be compound.
343 static void free_compound_page(struct page
*page
)
345 __free_pages_ok(page
, compound_order(page
));
348 void prep_compound_page(struct page
*page
, unsigned long order
)
351 int nr_pages
= 1 << order
;
353 set_compound_page_dtor(page
, free_compound_page
);
354 set_compound_order(page
, order
);
356 for (i
= 1; i
< nr_pages
; i
++) {
357 struct page
*p
= page
+ i
;
359 set_page_count(p
, 0);
360 p
->first_page
= page
;
364 /* update __split_huge_page_refcount if you change this function */
365 static int destroy_compound_page(struct page
*page
, unsigned long order
)
368 int nr_pages
= 1 << order
;
371 if (unlikely(compound_order(page
) != order
) ||
372 unlikely(!PageHead(page
))) {
377 __ClearPageHead(page
);
379 for (i
= 1; i
< nr_pages
; i
++) {
380 struct page
*p
= page
+ i
;
382 if (unlikely(!PageTail(p
) || (p
->first_page
!= page
))) {
392 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
397 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
398 * and __GFP_HIGHMEM from hard or soft interrupt context.
400 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
401 for (i
= 0; i
< (1 << order
); i
++)
402 clear_highpage(page
+ i
);
405 #ifdef CONFIG_DEBUG_PAGEALLOC
406 unsigned int _debug_guardpage_minorder
;
408 static int __init
debug_guardpage_minorder_setup(char *buf
)
412 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
413 printk(KERN_ERR
"Bad debug_guardpage_minorder value\n");
416 _debug_guardpage_minorder
= res
;
417 printk(KERN_INFO
"Setting debug_guardpage_minorder to %lu\n", res
);
420 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
422 static inline void set_page_guard_flag(struct page
*page
)
424 __set_bit(PAGE_DEBUG_FLAG_GUARD
, &page
->debug_flags
);
427 static inline void clear_page_guard_flag(struct page
*page
)
429 __clear_bit(PAGE_DEBUG_FLAG_GUARD
, &page
->debug_flags
);
432 static inline void set_page_guard_flag(struct page
*page
) { }
433 static inline void clear_page_guard_flag(struct page
*page
) { }
436 static inline void set_page_order(struct page
*page
, int order
)
438 set_page_private(page
, order
);
439 __SetPageBuddy(page
);
442 static inline void rmv_page_order(struct page
*page
)
444 __ClearPageBuddy(page
);
445 set_page_private(page
, 0);
449 * Locate the struct page for both the matching buddy in our
450 * pair (buddy1) and the combined O(n+1) page they form (page).
452 * 1) Any buddy B1 will have an order O twin B2 which satisfies
453 * the following equation:
455 * For example, if the starting buddy (buddy2) is #8 its order
457 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
459 * 2) Any buddy B will have an order O+1 parent P which
460 * satisfies the following equation:
463 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
465 static inline unsigned long
466 __find_buddy_index(unsigned long page_idx
, unsigned int order
)
468 return page_idx
^ (1 << order
);
472 * This function checks whether a page is free && is the buddy
473 * we can do coalesce a page and its buddy if
474 * (a) the buddy is not in a hole &&
475 * (b) the buddy is in the buddy system &&
476 * (c) a page and its buddy have the same order &&
477 * (d) a page and its buddy are in the same zone.
479 * For recording whether a page is in the buddy system, we set ->_mapcount -2.
480 * Setting, clearing, and testing _mapcount -2 is serialized by zone->lock.
482 * For recording page's order, we use page_private(page).
484 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
487 if (!pfn_valid_within(page_to_pfn(buddy
)))
490 if (page_zone_id(page
) != page_zone_id(buddy
))
493 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
494 VM_BUG_ON(page_count(buddy
) != 0);
498 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
499 VM_BUG_ON(page_count(buddy
) != 0);
506 * Freeing function for a buddy system allocator.
508 * The concept of a buddy system is to maintain direct-mapped table
509 * (containing bit values) for memory blocks of various "orders".
510 * The bottom level table contains the map for the smallest allocatable
511 * units of memory (here, pages), and each level above it describes
512 * pairs of units from the levels below, hence, "buddies".
513 * At a high level, all that happens here is marking the table entry
514 * at the bottom level available, and propagating the changes upward
515 * as necessary, plus some accounting needed to play nicely with other
516 * parts of the VM system.
517 * At each level, we keep a list of pages, which are heads of continuous
518 * free pages of length of (1 << order) and marked with _mapcount -2. Page's
519 * order is recorded in page_private(page) field.
520 * So when we are allocating or freeing one, we can derive the state of the
521 * other. That is, if we allocate a small block, and both were
522 * free, the remainder of the region must be split into blocks.
523 * If a block is freed, and its buddy is also free, then this
524 * triggers coalescing into a block of larger size.
529 static inline void __free_one_page(struct page
*page
,
530 struct zone
*zone
, unsigned int order
,
533 unsigned long page_idx
;
534 unsigned long combined_idx
;
535 unsigned long uninitialized_var(buddy_idx
);
538 if (unlikely(PageCompound(page
)))
539 if (unlikely(destroy_compound_page(page
, order
)))
542 VM_BUG_ON(migratetype
== -1);
544 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
546 VM_BUG_ON(page_idx
& ((1 << order
) - 1));
547 VM_BUG_ON(bad_range(zone
, page
));
549 while (order
< MAX_ORDER
-1) {
550 buddy_idx
= __find_buddy_index(page_idx
, order
);
551 buddy
= page
+ (buddy_idx
- page_idx
);
552 if (!page_is_buddy(page
, buddy
, order
))
555 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
556 * merge with it and move up one order.
558 if (page_is_guard(buddy
)) {
559 clear_page_guard_flag(buddy
);
560 set_page_private(page
, 0);
561 __mod_zone_freepage_state(zone
, 1 << order
,
564 list_del(&buddy
->lru
);
565 zone
->free_area
[order
].nr_free
--;
566 rmv_page_order(buddy
);
568 combined_idx
= buddy_idx
& page_idx
;
569 page
= page
+ (combined_idx
- page_idx
);
570 page_idx
= combined_idx
;
573 set_page_order(page
, order
);
576 * If this is not the largest possible page, check if the buddy
577 * of the next-highest order is free. If it is, it's possible
578 * that pages are being freed that will coalesce soon. In case,
579 * that is happening, add the free page to the tail of the list
580 * so it's less likely to be used soon and more likely to be merged
581 * as a higher order page
583 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
584 struct page
*higher_page
, *higher_buddy
;
585 combined_idx
= buddy_idx
& page_idx
;
586 higher_page
= page
+ (combined_idx
- page_idx
);
587 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
588 higher_buddy
= higher_page
+ (buddy_idx
- combined_idx
);
589 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
590 list_add_tail(&page
->lru
,
591 &zone
->free_area
[order
].free_list
[migratetype
]);
596 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
598 zone
->free_area
[order
].nr_free
++;
602 * free_page_mlock() -- clean up attempts to free and mlocked() page.
603 * Page should not be on lru, so no need to fix that up.
604 * free_pages_check() will verify...
606 static inline void free_page_mlock(struct page
*page
)
608 __dec_zone_page_state(page
, NR_MLOCK
);
609 __count_vm_event(UNEVICTABLE_MLOCKFREED
);
612 static inline int free_pages_check(struct page
*page
)
614 if (unlikely(page_mapcount(page
) |
615 (page
->mapping
!= NULL
) |
616 (atomic_read(&page
->_count
) != 0) |
617 (page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
) |
618 (mem_cgroup_bad_page_check(page
)))) {
622 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
623 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
628 * Frees a number of pages from the PCP lists
629 * Assumes all pages on list are in same zone, and of same order.
630 * count is the number of pages to free.
632 * If the zone was previously in an "all pages pinned" state then look to
633 * see if this freeing clears that state.
635 * And clear the zone's pages_scanned counter, to hold off the "all pages are
636 * pinned" detection logic.
638 static void free_pcppages_bulk(struct zone
*zone
, int count
,
639 struct per_cpu_pages
*pcp
)
645 spin_lock(&zone
->lock
);
646 zone
->all_unreclaimable
= 0;
647 zone
->pages_scanned
= 0;
651 struct list_head
*list
;
654 * Remove pages from lists in a round-robin fashion. A
655 * batch_free count is maintained that is incremented when an
656 * empty list is encountered. This is so more pages are freed
657 * off fuller lists instead of spinning excessively around empty
662 if (++migratetype
== MIGRATE_PCPTYPES
)
664 list
= &pcp
->lists
[migratetype
];
665 } while (list_empty(list
));
667 /* This is the only non-empty list. Free them all. */
668 if (batch_free
== MIGRATE_PCPTYPES
)
669 batch_free
= to_free
;
672 int mt
; /* migratetype of the to-be-freed page */
674 page
= list_entry(list
->prev
, struct page
, lru
);
675 /* must delete as __free_one_page list manipulates */
676 list_del(&page
->lru
);
677 mt
= get_freepage_migratetype(page
);
678 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
679 __free_one_page(page
, zone
, 0, mt
);
680 trace_mm_page_pcpu_drain(page
, 0, mt
);
681 if (is_migrate_cma(mt
))
682 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
, 1);
683 } while (--to_free
&& --batch_free
&& !list_empty(list
));
685 __mod_zone_page_state(zone
, NR_FREE_PAGES
, count
);
686 spin_unlock(&zone
->lock
);
689 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
,
692 spin_lock(&zone
->lock
);
693 zone
->all_unreclaimable
= 0;
694 zone
->pages_scanned
= 0;
696 __free_one_page(page
, zone
, order
, migratetype
);
697 if (unlikely(migratetype
!= MIGRATE_ISOLATE
))
698 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
699 spin_unlock(&zone
->lock
);
702 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
707 trace_mm_page_free(page
, order
);
708 kmemcheck_free_shadow(page
, order
);
711 page
->mapping
= NULL
;
712 for (i
= 0; i
< (1 << order
); i
++)
713 bad
+= free_pages_check(page
+ i
);
717 if (!PageHighMem(page
)) {
718 debug_check_no_locks_freed(page_address(page
),PAGE_SIZE
<<order
);
719 debug_check_no_obj_freed(page_address(page
),
722 arch_free_page(page
, order
);
723 kernel_map_pages(page
, 1 << order
, 0);
728 static void __free_pages_ok(struct page
*page
, unsigned int order
)
731 int wasMlocked
= __TestClearPageMlocked(page
);
734 if (!free_pages_prepare(page
, order
))
737 local_irq_save(flags
);
738 if (unlikely(wasMlocked
))
739 free_page_mlock(page
);
740 __count_vm_events(PGFREE
, 1 << order
);
741 migratetype
= get_pageblock_migratetype(page
);
742 set_freepage_migratetype(page
, migratetype
);
743 free_one_page(page_zone(page
), page
, order
, migratetype
);
744 local_irq_restore(flags
);
747 void __meminit
__free_pages_bootmem(struct page
*page
, unsigned int order
)
749 unsigned int nr_pages
= 1 << order
;
753 for (loop
= 0; loop
< nr_pages
; loop
++) {
754 struct page
*p
= &page
[loop
];
756 if (loop
+ 1 < nr_pages
)
758 __ClearPageReserved(p
);
759 set_page_count(p
, 0);
762 set_page_refcounted(page
);
763 __free_pages(page
, order
);
767 /* Free whole pageblock and set it's migration type to MIGRATE_CMA. */
768 void __init
init_cma_reserved_pageblock(struct page
*page
)
770 unsigned i
= pageblock_nr_pages
;
771 struct page
*p
= page
;
774 __ClearPageReserved(p
);
775 set_page_count(p
, 0);
778 set_page_refcounted(page
);
779 set_pageblock_migratetype(page
, MIGRATE_CMA
);
780 __free_pages(page
, pageblock_order
);
781 totalram_pages
+= pageblock_nr_pages
;
786 * The order of subdivision here is critical for the IO subsystem.
787 * Please do not alter this order without good reasons and regression
788 * testing. Specifically, as large blocks of memory are subdivided,
789 * the order in which smaller blocks are delivered depends on the order
790 * they're subdivided in this function. This is the primary factor
791 * influencing the order in which pages are delivered to the IO
792 * subsystem according to empirical testing, and this is also justified
793 * by considering the behavior of a buddy system containing a single
794 * large block of memory acted on by a series of small allocations.
795 * This behavior is a critical factor in sglist merging's success.
799 static inline void expand(struct zone
*zone
, struct page
*page
,
800 int low
, int high
, struct free_area
*area
,
803 unsigned long size
= 1 << high
;
809 VM_BUG_ON(bad_range(zone
, &page
[size
]));
811 #ifdef CONFIG_DEBUG_PAGEALLOC
812 if (high
< debug_guardpage_minorder()) {
814 * Mark as guard pages (or page), that will allow to
815 * merge back to allocator when buddy will be freed.
816 * Corresponding page table entries will not be touched,
817 * pages will stay not present in virtual address space
819 INIT_LIST_HEAD(&page
[size
].lru
);
820 set_page_guard_flag(&page
[size
]);
821 set_page_private(&page
[size
], high
);
822 /* Guard pages are not available for any usage */
823 __mod_zone_freepage_state(zone
, -(1 << high
),
828 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
830 set_page_order(&page
[size
], high
);
835 * This page is about to be returned from the page allocator
837 static inline int check_new_page(struct page
*page
)
839 if (unlikely(page_mapcount(page
) |
840 (page
->mapping
!= NULL
) |
841 (atomic_read(&page
->_count
) != 0) |
842 (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
) |
843 (mem_cgroup_bad_page_check(page
)))) {
850 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
854 for (i
= 0; i
< (1 << order
); i
++) {
855 struct page
*p
= page
+ i
;
856 if (unlikely(check_new_page(p
)))
860 set_page_private(page
, 0);
861 set_page_refcounted(page
);
863 arch_alloc_page(page
, order
);
864 kernel_map_pages(page
, 1 << order
, 1);
866 if (gfp_flags
& __GFP_ZERO
)
867 prep_zero_page(page
, order
, gfp_flags
);
869 if (order
&& (gfp_flags
& __GFP_COMP
))
870 prep_compound_page(page
, order
);
876 * Go through the free lists for the given migratetype and remove
877 * the smallest available page from the freelists
880 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
883 unsigned int current_order
;
884 struct free_area
* area
;
887 /* Find a page of the appropriate size in the preferred list */
888 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
889 area
= &(zone
->free_area
[current_order
]);
890 if (list_empty(&area
->free_list
[migratetype
]))
893 page
= list_entry(area
->free_list
[migratetype
].next
,
895 list_del(&page
->lru
);
896 rmv_page_order(page
);
898 expand(zone
, page
, order
, current_order
, area
, migratetype
);
907 * This array describes the order lists are fallen back to when
908 * the free lists for the desirable migrate type are depleted
910 static int fallbacks
[MIGRATE_TYPES
][4] = {
911 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
912 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
914 [MIGRATE_MOVABLE
] = { MIGRATE_CMA
, MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
915 [MIGRATE_CMA
] = { MIGRATE_RESERVE
}, /* Never used */
917 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
919 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
}, /* Never used */
920 [MIGRATE_ISOLATE
] = { MIGRATE_RESERVE
}, /* Never used */
924 * Move the free pages in a range to the free lists of the requested type.
925 * Note that start_page and end_pages are not aligned on a pageblock
926 * boundary. If alignment is required, use move_freepages_block()
928 int move_freepages(struct zone
*zone
,
929 struct page
*start_page
, struct page
*end_page
,
936 #ifndef CONFIG_HOLES_IN_ZONE
938 * page_zone is not safe to call in this context when
939 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
940 * anyway as we check zone boundaries in move_freepages_block().
941 * Remove at a later date when no bug reports exist related to
942 * grouping pages by mobility
944 BUG_ON(page_zone(start_page
) != page_zone(end_page
));
947 for (page
= start_page
; page
<= end_page
;) {
948 /* Make sure we are not inadvertently changing nodes */
949 VM_BUG_ON(page_to_nid(page
) != zone_to_nid(zone
));
951 if (!pfn_valid_within(page_to_pfn(page
))) {
956 if (!PageBuddy(page
)) {
961 order
= page_order(page
);
962 list_move(&page
->lru
,
963 &zone
->free_area
[order
].free_list
[migratetype
]);
964 set_freepage_migratetype(page
, migratetype
);
966 pages_moved
+= 1 << order
;
972 int move_freepages_block(struct zone
*zone
, struct page
*page
,
975 unsigned long start_pfn
, end_pfn
;
976 struct page
*start_page
, *end_page
;
978 start_pfn
= page_to_pfn(page
);
979 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
980 start_page
= pfn_to_page(start_pfn
);
981 end_page
= start_page
+ pageblock_nr_pages
- 1;
982 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
984 /* Do not cross zone boundaries */
985 if (start_pfn
< zone
->zone_start_pfn
)
987 if (end_pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
990 return move_freepages(zone
, start_page
, end_page
, migratetype
);
993 static void change_pageblock_range(struct page
*pageblock_page
,
994 int start_order
, int migratetype
)
996 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
998 while (nr_pageblocks
--) {
999 set_pageblock_migratetype(pageblock_page
, migratetype
);
1000 pageblock_page
+= pageblock_nr_pages
;
1004 /* Remove an element from the buddy allocator from the fallback list */
1005 static inline struct page
*
1006 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
)
1008 struct free_area
* area
;
1013 /* Find the largest possible block of pages in the other list */
1014 for (current_order
= MAX_ORDER
-1; current_order
>= order
;
1017 migratetype
= fallbacks
[start_migratetype
][i
];
1019 /* MIGRATE_RESERVE handled later if necessary */
1020 if (migratetype
== MIGRATE_RESERVE
)
1023 area
= &(zone
->free_area
[current_order
]);
1024 if (list_empty(&area
->free_list
[migratetype
]))
1027 page
= list_entry(area
->free_list
[migratetype
].next
,
1032 * If breaking a large block of pages, move all free
1033 * pages to the preferred allocation list. If falling
1034 * back for a reclaimable kernel allocation, be more
1035 * aggressive about taking ownership of free pages
1037 * On the other hand, never change migration
1038 * type of MIGRATE_CMA pageblocks nor move CMA
1039 * pages on different free lists. We don't
1040 * want unmovable pages to be allocated from
1041 * MIGRATE_CMA areas.
1043 if (!is_migrate_cma(migratetype
) &&
1044 (unlikely(current_order
>= pageblock_order
/ 2) ||
1045 start_migratetype
== MIGRATE_RECLAIMABLE
||
1046 page_group_by_mobility_disabled
)) {
1048 pages
= move_freepages_block(zone
, page
,
1051 /* Claim the whole block if over half of it is free */
1052 if (pages
>= (1 << (pageblock_order
-1)) ||
1053 page_group_by_mobility_disabled
)
1054 set_pageblock_migratetype(page
,
1057 migratetype
= start_migratetype
;
1060 /* Remove the page from the freelists */
1061 list_del(&page
->lru
);
1062 rmv_page_order(page
);
1064 /* Take ownership for orders >= pageblock_order */
1065 if (current_order
>= pageblock_order
&&
1066 !is_migrate_cma(migratetype
))
1067 change_pageblock_range(page
, current_order
,
1070 expand(zone
, page
, order
, current_order
, area
,
1071 is_migrate_cma(migratetype
)
1072 ? migratetype
: start_migratetype
);
1074 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
1075 start_migratetype
, migratetype
);
1085 * Do the hard work of removing an element from the buddy allocator.
1086 * Call me with the zone->lock already held.
1088 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
1094 page
= __rmqueue_smallest(zone
, order
, migratetype
);
1096 if (unlikely(!page
) && migratetype
!= MIGRATE_RESERVE
) {
1097 page
= __rmqueue_fallback(zone
, order
, migratetype
);
1100 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1101 * is used because __rmqueue_smallest is an inline function
1102 * and we want just one call site
1105 migratetype
= MIGRATE_RESERVE
;
1110 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1115 * Obtain a specified number of elements from the buddy allocator, all under
1116 * a single hold of the lock, for efficiency. Add them to the supplied list.
1117 * Returns the number of new pages which were placed at *list.
1119 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1120 unsigned long count
, struct list_head
*list
,
1121 int migratetype
, int cold
)
1123 int mt
= migratetype
, i
;
1125 spin_lock(&zone
->lock
);
1126 for (i
= 0; i
< count
; ++i
) {
1127 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
1128 if (unlikely(page
== NULL
))
1132 * Split buddy pages returned by expand() are received here
1133 * in physical page order. The page is added to the callers and
1134 * list and the list head then moves forward. From the callers
1135 * perspective, the linked list is ordered by page number in
1136 * some conditions. This is useful for IO devices that can
1137 * merge IO requests if the physical pages are ordered
1140 if (likely(cold
== 0))
1141 list_add(&page
->lru
, list
);
1143 list_add_tail(&page
->lru
, list
);
1144 if (IS_ENABLED(CONFIG_CMA
)) {
1145 mt
= get_pageblock_migratetype(page
);
1146 if (!is_migrate_cma(mt
) && mt
!= MIGRATE_ISOLATE
)
1149 set_freepage_migratetype(page
, mt
);
1151 if (is_migrate_cma(mt
))
1152 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
1155 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
1156 spin_unlock(&zone
->lock
);
1162 * Called from the vmstat counter updater to drain pagesets of this
1163 * currently executing processor on remote nodes after they have
1166 * Note that this function must be called with the thread pinned to
1167 * a single processor.
1169 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
1171 unsigned long flags
;
1174 local_irq_save(flags
);
1175 if (pcp
->count
>= pcp
->batch
)
1176 to_drain
= pcp
->batch
;
1178 to_drain
= pcp
->count
;
1180 free_pcppages_bulk(zone
, to_drain
, pcp
);
1181 pcp
->count
-= to_drain
;
1183 local_irq_restore(flags
);
1188 * Drain pages of the indicated processor.
1190 * The processor must either be the current processor and the
1191 * thread pinned to the current processor or a processor that
1194 static void drain_pages(unsigned int cpu
)
1196 unsigned long flags
;
1199 for_each_populated_zone(zone
) {
1200 struct per_cpu_pageset
*pset
;
1201 struct per_cpu_pages
*pcp
;
1203 local_irq_save(flags
);
1204 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
1208 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1211 local_irq_restore(flags
);
1216 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1218 void drain_local_pages(void *arg
)
1220 drain_pages(smp_processor_id());
1224 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1226 * Note that this code is protected against sending an IPI to an offline
1227 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1228 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1229 * nothing keeps CPUs from showing up after we populated the cpumask and
1230 * before the call to on_each_cpu_mask().
1232 void drain_all_pages(void)
1235 struct per_cpu_pageset
*pcp
;
1239 * Allocate in the BSS so we wont require allocation in
1240 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1242 static cpumask_t cpus_with_pcps
;
1245 * We don't care about racing with CPU hotplug event
1246 * as offline notification will cause the notified
1247 * cpu to drain that CPU pcps and on_each_cpu_mask
1248 * disables preemption as part of its processing
1250 for_each_online_cpu(cpu
) {
1251 bool has_pcps
= false;
1252 for_each_populated_zone(zone
) {
1253 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
1254 if (pcp
->pcp
.count
) {
1260 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
1262 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
1264 on_each_cpu_mask(&cpus_with_pcps
, drain_local_pages
, NULL
, 1);
1267 #ifdef CONFIG_HIBERNATION
1269 void mark_free_pages(struct zone
*zone
)
1271 unsigned long pfn
, max_zone_pfn
;
1272 unsigned long flags
;
1274 struct list_head
*curr
;
1276 if (!zone
->spanned_pages
)
1279 spin_lock_irqsave(&zone
->lock
, flags
);
1281 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
1282 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1283 if (pfn_valid(pfn
)) {
1284 struct page
*page
= pfn_to_page(pfn
);
1286 if (!swsusp_page_is_forbidden(page
))
1287 swsusp_unset_page_free(page
);
1290 for_each_migratetype_order(order
, t
) {
1291 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
1294 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
1295 for (i
= 0; i
< (1UL << order
); i
++)
1296 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
1299 spin_unlock_irqrestore(&zone
->lock
, flags
);
1301 #endif /* CONFIG_PM */
1304 * Free a 0-order page
1305 * cold == 1 ? free a cold page : free a hot page
1307 void free_hot_cold_page(struct page
*page
, int cold
)
1309 struct zone
*zone
= page_zone(page
);
1310 struct per_cpu_pages
*pcp
;
1311 unsigned long flags
;
1313 int wasMlocked
= __TestClearPageMlocked(page
);
1315 if (!free_pages_prepare(page
, 0))
1318 migratetype
= get_pageblock_migratetype(page
);
1319 set_freepage_migratetype(page
, migratetype
);
1320 local_irq_save(flags
);
1321 if (unlikely(wasMlocked
))
1322 free_page_mlock(page
);
1323 __count_vm_event(PGFREE
);
1326 * We only track unmovable, reclaimable and movable on pcp lists.
1327 * Free ISOLATE pages back to the allocator because they are being
1328 * offlined but treat RESERVE as movable pages so we can get those
1329 * areas back if necessary. Otherwise, we may have to free
1330 * excessively into the page allocator
1332 if (migratetype
>= MIGRATE_PCPTYPES
) {
1333 if (unlikely(migratetype
== MIGRATE_ISOLATE
)) {
1334 free_one_page(zone
, page
, 0, migratetype
);
1337 migratetype
= MIGRATE_MOVABLE
;
1340 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1342 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
1344 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
1346 if (pcp
->count
>= pcp
->high
) {
1347 free_pcppages_bulk(zone
, pcp
->batch
, pcp
);
1348 pcp
->count
-= pcp
->batch
;
1352 local_irq_restore(flags
);
1356 * Free a list of 0-order pages
1358 void free_hot_cold_page_list(struct list_head
*list
, int cold
)
1360 struct page
*page
, *next
;
1362 list_for_each_entry_safe(page
, next
, list
, lru
) {
1363 trace_mm_page_free_batched(page
, cold
);
1364 free_hot_cold_page(page
, cold
);
1369 * split_page takes a non-compound higher-order page, and splits it into
1370 * n (1<<order) sub-pages: page[0..n]
1371 * Each sub-page must be freed individually.
1373 * Note: this is probably too low level an operation for use in drivers.
1374 * Please consult with lkml before using this in your driver.
1376 void split_page(struct page
*page
, unsigned int order
)
1380 VM_BUG_ON(PageCompound(page
));
1381 VM_BUG_ON(!page_count(page
));
1383 #ifdef CONFIG_KMEMCHECK
1385 * Split shadow pages too, because free(page[0]) would
1386 * otherwise free the whole shadow.
1388 if (kmemcheck_page_is_tracked(page
))
1389 split_page(virt_to_page(page
[0].shadow
), order
);
1392 for (i
= 1; i
< (1 << order
); i
++)
1393 set_page_refcounted(page
+ i
);
1397 * Similar to the split_page family of functions except that the page
1398 * required at the given order and being isolated now to prevent races
1399 * with parallel allocators
1401 int capture_free_page(struct page
*page
, int alloc_order
, int migratetype
)
1404 unsigned long watermark
;
1408 BUG_ON(!PageBuddy(page
));
1410 zone
= page_zone(page
);
1411 order
= page_order(page
);
1413 /* Obey watermarks as if the page was being allocated */
1414 watermark
= low_wmark_pages(zone
) + (1 << order
);
1415 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
1418 /* Remove page from free list */
1419 list_del(&page
->lru
);
1420 zone
->free_area
[order
].nr_free
--;
1421 rmv_page_order(page
);
1423 mt
= get_pageblock_migratetype(page
);
1424 if (unlikely(mt
!= MIGRATE_ISOLATE
))
1425 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
1427 if (alloc_order
!= order
)
1428 expand(zone
, page
, alloc_order
, order
,
1429 &zone
->free_area
[order
], migratetype
);
1431 /* Set the pageblock if the captured page is at least a pageblock */
1432 if (order
>= pageblock_order
- 1) {
1433 struct page
*endpage
= page
+ (1 << order
) - 1;
1434 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
1435 int mt
= get_pageblock_migratetype(page
);
1436 if (mt
!= MIGRATE_ISOLATE
&& !is_migrate_cma(mt
))
1437 set_pageblock_migratetype(page
,
1442 return 1UL << order
;
1446 * Similar to split_page except the page is already free. As this is only
1447 * being used for migration, the migratetype of the block also changes.
1448 * As this is called with interrupts disabled, the caller is responsible
1449 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1452 * Note: this is probably too low level an operation for use in drivers.
1453 * Please consult with lkml before using this in your driver.
1455 int split_free_page(struct page
*page
)
1460 BUG_ON(!PageBuddy(page
));
1461 order
= page_order(page
);
1463 nr_pages
= capture_free_page(page
, order
, 0);
1467 /* Split into individual pages */
1468 set_page_refcounted(page
);
1469 split_page(page
, order
);
1474 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1475 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1479 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
1480 struct zone
*zone
, int order
, gfp_t gfp_flags
,
1483 unsigned long flags
;
1485 int cold
= !!(gfp_flags
& __GFP_COLD
);
1488 if (likely(order
== 0)) {
1489 struct per_cpu_pages
*pcp
;
1490 struct list_head
*list
;
1492 local_irq_save(flags
);
1493 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1494 list
= &pcp
->lists
[migratetype
];
1495 if (list_empty(list
)) {
1496 pcp
->count
+= rmqueue_bulk(zone
, 0,
1499 if (unlikely(list_empty(list
)))
1504 page
= list_entry(list
->prev
, struct page
, lru
);
1506 page
= list_entry(list
->next
, struct page
, lru
);
1508 list_del(&page
->lru
);
1511 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
1513 * __GFP_NOFAIL is not to be used in new code.
1515 * All __GFP_NOFAIL callers should be fixed so that they
1516 * properly detect and handle allocation failures.
1518 * We most definitely don't want callers attempting to
1519 * allocate greater than order-1 page units with
1522 WARN_ON_ONCE(order
> 1);
1524 spin_lock_irqsave(&zone
->lock
, flags
);
1525 page
= __rmqueue(zone
, order
, migratetype
);
1526 spin_unlock(&zone
->lock
);
1529 __mod_zone_freepage_state(zone
, -(1 << order
),
1530 get_pageblock_migratetype(page
));
1533 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
1534 zone_statistics(preferred_zone
, zone
, gfp_flags
);
1535 local_irq_restore(flags
);
1537 VM_BUG_ON(bad_range(zone
, page
));
1538 if (prep_new_page(page
, order
, gfp_flags
))
1543 local_irq_restore(flags
);
1547 #ifdef CONFIG_FAIL_PAGE_ALLOC
1550 struct fault_attr attr
;
1552 u32 ignore_gfp_highmem
;
1553 u32 ignore_gfp_wait
;
1555 } fail_page_alloc
= {
1556 .attr
= FAULT_ATTR_INITIALIZER
,
1557 .ignore_gfp_wait
= 1,
1558 .ignore_gfp_highmem
= 1,
1562 static int __init
setup_fail_page_alloc(char *str
)
1564 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
1566 __setup("fail_page_alloc=", setup_fail_page_alloc
);
1568 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1570 if (order
< fail_page_alloc
.min_order
)
1572 if (gfp_mask
& __GFP_NOFAIL
)
1574 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
1576 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
1579 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
1582 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1584 static int __init
fail_page_alloc_debugfs(void)
1586 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
1589 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
1590 &fail_page_alloc
.attr
);
1592 return PTR_ERR(dir
);
1594 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
1595 &fail_page_alloc
.ignore_gfp_wait
))
1597 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
1598 &fail_page_alloc
.ignore_gfp_highmem
))
1600 if (!debugfs_create_u32("min-order", mode
, dir
,
1601 &fail_page_alloc
.min_order
))
1606 debugfs_remove_recursive(dir
);
1611 late_initcall(fail_page_alloc_debugfs
);
1613 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1615 #else /* CONFIG_FAIL_PAGE_ALLOC */
1617 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1622 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1625 * Return true if free pages are above 'mark'. This takes into account the order
1626 * of the allocation.
1628 static bool __zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1629 int classzone_idx
, int alloc_flags
, long free_pages
)
1631 /* free_pages my go negative - that's OK */
1633 long lowmem_reserve
= z
->lowmem_reserve
[classzone_idx
];
1636 free_pages
-= (1 << order
) - 1;
1637 if (alloc_flags
& ALLOC_HIGH
)
1639 if (alloc_flags
& ALLOC_HARDER
)
1642 /* If allocation can't use CMA areas don't use free CMA pages */
1643 if (!(alloc_flags
& ALLOC_CMA
))
1644 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
1646 if (free_pages
<= min
+ lowmem_reserve
)
1648 for (o
= 0; o
< order
; o
++) {
1649 /* At the next order, this order's pages become unavailable */
1650 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1652 /* Require fewer higher order pages to be free */
1655 if (free_pages
<= min
)
1661 #ifdef CONFIG_MEMORY_ISOLATION
1662 static inline unsigned long nr_zone_isolate_freepages(struct zone
*zone
)
1664 if (unlikely(zone
->nr_pageblock_isolate
))
1665 return zone
->nr_pageblock_isolate
* pageblock_nr_pages
;
1669 static inline unsigned long nr_zone_isolate_freepages(struct zone
*zone
)
1675 bool zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1676 int classzone_idx
, int alloc_flags
)
1678 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1679 zone_page_state(z
, NR_FREE_PAGES
));
1682 bool zone_watermark_ok_safe(struct zone
*z
, int order
, unsigned long mark
,
1683 int classzone_idx
, int alloc_flags
)
1685 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
1687 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
1688 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
1691 * If the zone has MIGRATE_ISOLATE type free pages, we should consider
1692 * it. nr_zone_isolate_freepages is never accurate so kswapd might not
1693 * sleep although it could do so. But this is more desirable for memory
1694 * hotplug than sleeping which can cause a livelock in the direct
1697 free_pages
-= nr_zone_isolate_freepages(z
);
1698 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1704 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1705 * skip over zones that are not allowed by the cpuset, or that have
1706 * been recently (in last second) found to be nearly full. See further
1707 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1708 * that have to skip over a lot of full or unallowed zones.
1710 * If the zonelist cache is present in the passed in zonelist, then
1711 * returns a pointer to the allowed node mask (either the current
1712 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1714 * If the zonelist cache is not available for this zonelist, does
1715 * nothing and returns NULL.
1717 * If the fullzones BITMAP in the zonelist cache is stale (more than
1718 * a second since last zap'd) then we zap it out (clear its bits.)
1720 * We hold off even calling zlc_setup, until after we've checked the
1721 * first zone in the zonelist, on the theory that most allocations will
1722 * be satisfied from that first zone, so best to examine that zone as
1723 * quickly as we can.
1725 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1727 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1728 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1730 zlc
= zonelist
->zlcache_ptr
;
1734 if (time_after(jiffies
, zlc
->last_full_zap
+ HZ
)) {
1735 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1736 zlc
->last_full_zap
= jiffies
;
1739 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1740 &cpuset_current_mems_allowed
:
1741 &node_states
[N_HIGH_MEMORY
];
1742 return allowednodes
;
1746 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1747 * if it is worth looking at further for free memory:
1748 * 1) Check that the zone isn't thought to be full (doesn't have its
1749 * bit set in the zonelist_cache fullzones BITMAP).
1750 * 2) Check that the zones node (obtained from the zonelist_cache
1751 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1752 * Return true (non-zero) if zone is worth looking at further, or
1753 * else return false (zero) if it is not.
1755 * This check -ignores- the distinction between various watermarks,
1756 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1757 * found to be full for any variation of these watermarks, it will
1758 * be considered full for up to one second by all requests, unless
1759 * we are so low on memory on all allowed nodes that we are forced
1760 * into the second scan of the zonelist.
1762 * In the second scan we ignore this zonelist cache and exactly
1763 * apply the watermarks to all zones, even it is slower to do so.
1764 * We are low on memory in the second scan, and should leave no stone
1765 * unturned looking for a free page.
1767 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1768 nodemask_t
*allowednodes
)
1770 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1771 int i
; /* index of *z in zonelist zones */
1772 int n
; /* node that zone *z is on */
1774 zlc
= zonelist
->zlcache_ptr
;
1778 i
= z
- zonelist
->_zonerefs
;
1781 /* This zone is worth trying if it is allowed but not full */
1782 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1786 * Given 'z' scanning a zonelist, set the corresponding bit in
1787 * zlc->fullzones, so that subsequent attempts to allocate a page
1788 * from that zone don't waste time re-examining it.
1790 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1792 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1793 int i
; /* index of *z in zonelist zones */
1795 zlc
= zonelist
->zlcache_ptr
;
1799 i
= z
- zonelist
->_zonerefs
;
1801 set_bit(i
, zlc
->fullzones
);
1805 * clear all zones full, called after direct reclaim makes progress so that
1806 * a zone that was recently full is not skipped over for up to a second
1808 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
1810 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1812 zlc
= zonelist
->zlcache_ptr
;
1816 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1819 #else /* CONFIG_NUMA */
1821 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1826 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1827 nodemask_t
*allowednodes
)
1832 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1836 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
1839 #endif /* CONFIG_NUMA */
1842 * get_page_from_freelist goes through the zonelist trying to allocate
1845 static struct page
*
1846 get_page_from_freelist(gfp_t gfp_mask
, nodemask_t
*nodemask
, unsigned int order
,
1847 struct zonelist
*zonelist
, int high_zoneidx
, int alloc_flags
,
1848 struct zone
*preferred_zone
, int migratetype
)
1851 struct page
*page
= NULL
;
1854 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1855 int zlc_active
= 0; /* set if using zonelist_cache */
1856 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1858 classzone_idx
= zone_idx(preferred_zone
);
1861 * Scan zonelist, looking for a zone with enough free.
1862 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1864 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
1865 high_zoneidx
, nodemask
) {
1866 if (NUMA_BUILD
&& zlc_active
&&
1867 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1869 if ((alloc_flags
& ALLOC_CPUSET
) &&
1870 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1873 * When allocating a page cache page for writing, we
1874 * want to get it from a zone that is within its dirty
1875 * limit, such that no single zone holds more than its
1876 * proportional share of globally allowed dirty pages.
1877 * The dirty limits take into account the zone's
1878 * lowmem reserves and high watermark so that kswapd
1879 * should be able to balance it without having to
1880 * write pages from its LRU list.
1882 * This may look like it could increase pressure on
1883 * lower zones by failing allocations in higher zones
1884 * before they are full. But the pages that do spill
1885 * over are limited as the lower zones are protected
1886 * by this very same mechanism. It should not become
1887 * a practical burden to them.
1889 * XXX: For now, allow allocations to potentially
1890 * exceed the per-zone dirty limit in the slowpath
1891 * (ALLOC_WMARK_LOW unset) before going into reclaim,
1892 * which is important when on a NUMA setup the allowed
1893 * zones are together not big enough to reach the
1894 * global limit. The proper fix for these situations
1895 * will require awareness of zones in the
1896 * dirty-throttling and the flusher threads.
1898 if ((alloc_flags
& ALLOC_WMARK_LOW
) &&
1899 (gfp_mask
& __GFP_WRITE
) && !zone_dirty_ok(zone
))
1900 goto this_zone_full
;
1902 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
1903 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
1907 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
1908 if (zone_watermark_ok(zone
, order
, mark
,
1909 classzone_idx
, alloc_flags
))
1912 if (NUMA_BUILD
&& !did_zlc_setup
&& nr_online_nodes
> 1) {
1914 * we do zlc_setup if there are multiple nodes
1915 * and before considering the first zone allowed
1918 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1923 if (zone_reclaim_mode
== 0)
1924 goto this_zone_full
;
1927 * As we may have just activated ZLC, check if the first
1928 * eligible zone has failed zone_reclaim recently.
1930 if (NUMA_BUILD
&& zlc_active
&&
1931 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1934 ret
= zone_reclaim(zone
, gfp_mask
, order
);
1936 case ZONE_RECLAIM_NOSCAN
:
1939 case ZONE_RECLAIM_FULL
:
1940 /* scanned but unreclaimable */
1943 /* did we reclaim enough */
1944 if (!zone_watermark_ok(zone
, order
, mark
,
1945 classzone_idx
, alloc_flags
))
1946 goto this_zone_full
;
1951 page
= buffered_rmqueue(preferred_zone
, zone
, order
,
1952 gfp_mask
, migratetype
);
1957 zlc_mark_zone_full(zonelist
, z
);
1960 if (unlikely(NUMA_BUILD
&& page
== NULL
&& zlc_active
)) {
1961 /* Disable zlc cache for second zonelist scan */
1968 * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was
1969 * necessary to allocate the page. The expectation is
1970 * that the caller is taking steps that will free more
1971 * memory. The caller should avoid the page being used
1972 * for !PFMEMALLOC purposes.
1974 page
->pfmemalloc
= !!(alloc_flags
& ALLOC_NO_WATERMARKS
);
1980 * Large machines with many possible nodes should not always dump per-node
1981 * meminfo in irq context.
1983 static inline bool should_suppress_show_mem(void)
1988 ret
= in_interrupt();
1993 static DEFINE_RATELIMIT_STATE(nopage_rs
,
1994 DEFAULT_RATELIMIT_INTERVAL
,
1995 DEFAULT_RATELIMIT_BURST
);
1997 void warn_alloc_failed(gfp_t gfp_mask
, int order
, const char *fmt
, ...)
1999 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
2001 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
2002 debug_guardpage_minorder() > 0)
2006 * This documents exceptions given to allocations in certain
2007 * contexts that are allowed to allocate outside current's set
2010 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2011 if (test_thread_flag(TIF_MEMDIE
) ||
2012 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
2013 filter
&= ~SHOW_MEM_FILTER_NODES
;
2014 if (in_interrupt() || !(gfp_mask
& __GFP_WAIT
))
2015 filter
&= ~SHOW_MEM_FILTER_NODES
;
2018 struct va_format vaf
;
2021 va_start(args
, fmt
);
2026 pr_warn("%pV", &vaf
);
2031 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
2032 current
->comm
, order
, gfp_mask
);
2035 if (!should_suppress_show_mem())
2040 should_alloc_retry(gfp_t gfp_mask
, unsigned int order
,
2041 unsigned long did_some_progress
,
2042 unsigned long pages_reclaimed
)
2044 /* Do not loop if specifically requested */
2045 if (gfp_mask
& __GFP_NORETRY
)
2048 /* Always retry if specifically requested */
2049 if (gfp_mask
& __GFP_NOFAIL
)
2053 * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
2054 * making forward progress without invoking OOM. Suspend also disables
2055 * storage devices so kswapd will not help. Bail if we are suspending.
2057 if (!did_some_progress
&& pm_suspended_storage())
2061 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
2062 * means __GFP_NOFAIL, but that may not be true in other
2065 if (order
<= PAGE_ALLOC_COSTLY_ORDER
)
2069 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
2070 * specified, then we retry until we no longer reclaim any pages
2071 * (above), or we've reclaimed an order of pages at least as
2072 * large as the allocation's order. In both cases, if the
2073 * allocation still fails, we stop retrying.
2075 if (gfp_mask
& __GFP_REPEAT
&& pages_reclaimed
< (1 << order
))
2081 static inline struct page
*
2082 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
2083 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2084 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2089 /* Acquire the OOM killer lock for the zones in zonelist */
2090 if (!try_set_zonelist_oom(zonelist
, gfp_mask
)) {
2091 schedule_timeout_uninterruptible(1);
2096 * Go through the zonelist yet one more time, keep very high watermark
2097 * here, this is only to catch a parallel oom killing, we must fail if
2098 * we're still under heavy pressure.
2100 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
,
2101 order
, zonelist
, high_zoneidx
,
2102 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
,
2103 preferred_zone
, migratetype
);
2107 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2108 /* The OOM killer will not help higher order allocs */
2109 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2111 /* The OOM killer does not needlessly kill tasks for lowmem */
2112 if (high_zoneidx
< ZONE_NORMAL
)
2115 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
2116 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
2117 * The caller should handle page allocation failure by itself if
2118 * it specifies __GFP_THISNODE.
2119 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
2121 if (gfp_mask
& __GFP_THISNODE
)
2124 /* Exhausted what can be done so it's blamo time */
2125 out_of_memory(zonelist
, gfp_mask
, order
, nodemask
, false);
2128 clear_zonelist_oom(zonelist
, gfp_mask
);
2132 #ifdef CONFIG_COMPACTION
2133 /* Try memory compaction for high-order allocations before reclaim */
2134 static struct page
*
2135 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2136 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2137 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2138 int migratetype
, bool sync_migration
,
2139 bool *contended_compaction
, bool *deferred_compaction
,
2140 unsigned long *did_some_progress
)
2142 struct page
*page
= NULL
;
2147 if (compaction_deferred(preferred_zone
, order
)) {
2148 *deferred_compaction
= true;
2152 current
->flags
|= PF_MEMALLOC
;
2153 *did_some_progress
= try_to_compact_pages(zonelist
, order
, gfp_mask
,
2154 nodemask
, sync_migration
,
2155 contended_compaction
, &page
);
2156 current
->flags
&= ~PF_MEMALLOC
;
2158 /* If compaction captured a page, prep and use it */
2160 prep_new_page(page
, order
, gfp_mask
);
2164 if (*did_some_progress
!= COMPACT_SKIPPED
) {
2165 /* Page migration frees to the PCP lists but we want merging */
2166 drain_pages(get_cpu());
2169 page
= get_page_from_freelist(gfp_mask
, nodemask
,
2170 order
, zonelist
, high_zoneidx
,
2171 alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2172 preferred_zone
, migratetype
);
2175 preferred_zone
->compact_blockskip_flush
= false;
2176 preferred_zone
->compact_considered
= 0;
2177 preferred_zone
->compact_defer_shift
= 0;
2178 if (order
>= preferred_zone
->compact_order_failed
)
2179 preferred_zone
->compact_order_failed
= order
+ 1;
2180 count_vm_event(COMPACTSUCCESS
);
2185 * It's bad if compaction run occurs and fails.
2186 * The most likely reason is that pages exist,
2187 * but not enough to satisfy watermarks.
2189 count_vm_event(COMPACTFAIL
);
2192 * As async compaction considers a subset of pageblocks, only
2193 * defer if the failure was a sync compaction failure.
2196 defer_compaction(preferred_zone
, order
);
2204 static inline struct page
*
2205 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2206 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2207 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2208 int migratetype
, bool sync_migration
,
2209 bool *contended_compaction
, bool *deferred_compaction
,
2210 unsigned long *did_some_progress
)
2214 #endif /* CONFIG_COMPACTION */
2216 /* Perform direct synchronous page reclaim */
2218 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
, struct zonelist
*zonelist
,
2219 nodemask_t
*nodemask
)
2221 struct reclaim_state reclaim_state
;
2226 /* We now go into synchronous reclaim */
2227 cpuset_memory_pressure_bump();
2228 current
->flags
|= PF_MEMALLOC
;
2229 lockdep_set_current_reclaim_state(gfp_mask
);
2230 reclaim_state
.reclaimed_slab
= 0;
2231 current
->reclaim_state
= &reclaim_state
;
2233 progress
= try_to_free_pages(zonelist
, order
, gfp_mask
, nodemask
);
2235 current
->reclaim_state
= NULL
;
2236 lockdep_clear_current_reclaim_state();
2237 current
->flags
&= ~PF_MEMALLOC
;
2244 /* The really slow allocator path where we enter direct reclaim */
2245 static inline struct page
*
2246 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
2247 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2248 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2249 int migratetype
, unsigned long *did_some_progress
)
2251 struct page
*page
= NULL
;
2252 bool drained
= false;
2254 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, zonelist
,
2256 if (unlikely(!(*did_some_progress
)))
2259 /* After successful reclaim, reconsider all zones for allocation */
2261 zlc_clear_zones_full(zonelist
);
2264 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
2265 zonelist
, high_zoneidx
,
2266 alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2267 preferred_zone
, migratetype
);
2270 * If an allocation failed after direct reclaim, it could be because
2271 * pages are pinned on the per-cpu lists. Drain them and try again
2273 if (!page
&& !drained
) {
2283 * This is called in the allocator slow-path if the allocation request is of
2284 * sufficient urgency to ignore watermarks and take other desperate measures
2286 static inline struct page
*
2287 __alloc_pages_high_priority(gfp_t gfp_mask
, unsigned int order
,
2288 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2289 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2295 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
2296 zonelist
, high_zoneidx
, ALLOC_NO_WATERMARKS
,
2297 preferred_zone
, migratetype
);
2299 if (!page
&& gfp_mask
& __GFP_NOFAIL
)
2300 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2301 } while (!page
&& (gfp_mask
& __GFP_NOFAIL
));
2307 void wake_all_kswapd(unsigned int order
, struct zonelist
*zonelist
,
2308 enum zone_type high_zoneidx
,
2309 enum zone_type classzone_idx
)
2314 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
)
2315 wakeup_kswapd(zone
, order
, classzone_idx
);
2319 gfp_to_alloc_flags(gfp_t gfp_mask
)
2321 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
2322 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2324 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2325 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
2328 * The caller may dip into page reserves a bit more if the caller
2329 * cannot run direct reclaim, or if the caller has realtime scheduling
2330 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2331 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
2333 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
2337 * Not worth trying to allocate harder for
2338 * __GFP_NOMEMALLOC even if it can't schedule.
2340 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2341 alloc_flags
|= ALLOC_HARDER
;
2343 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
2344 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
2346 alloc_flags
&= ~ALLOC_CPUSET
;
2347 } else if (unlikely(rt_task(current
)) && !in_interrupt())
2348 alloc_flags
|= ALLOC_HARDER
;
2350 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
2351 if (gfp_mask
& __GFP_MEMALLOC
)
2352 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2353 else if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
2354 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2355 else if (!in_interrupt() &&
2356 ((current
->flags
& PF_MEMALLOC
) ||
2357 unlikely(test_thread_flag(TIF_MEMDIE
))))
2358 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2361 if (allocflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
2362 alloc_flags
|= ALLOC_CMA
;
2367 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
2369 return !!(gfp_to_alloc_flags(gfp_mask
) & ALLOC_NO_WATERMARKS
);
2372 static inline struct page
*
2373 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
2374 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2375 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2378 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2379 struct page
*page
= NULL
;
2381 unsigned long pages_reclaimed
= 0;
2382 unsigned long did_some_progress
;
2383 bool sync_migration
= false;
2384 bool deferred_compaction
= false;
2385 bool contended_compaction
= false;
2388 * In the slowpath, we sanity check order to avoid ever trying to
2389 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2390 * be using allocators in order of preference for an area that is
2393 if (order
>= MAX_ORDER
) {
2394 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
2399 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
2400 * __GFP_NOWARN set) should not cause reclaim since the subsystem
2401 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
2402 * using a larger set of nodes after it has established that the
2403 * allowed per node queues are empty and that nodes are
2406 if (NUMA_BUILD
&& (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
2410 wake_all_kswapd(order
, zonelist
, high_zoneidx
,
2411 zone_idx(preferred_zone
));
2414 * OK, we're below the kswapd watermark and have kicked background
2415 * reclaim. Now things get more complex, so set up alloc_flags according
2416 * to how we want to proceed.
2418 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
2421 * Find the true preferred zone if the allocation is unconstrained by
2424 if (!(alloc_flags
& ALLOC_CPUSET
) && !nodemask
)
2425 first_zones_zonelist(zonelist
, high_zoneidx
, NULL
,
2429 /* This is the last chance, in general, before the goto nopage. */
2430 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
, zonelist
,
2431 high_zoneidx
, alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2432 preferred_zone
, migratetype
);
2436 /* Allocate without watermarks if the context allows */
2437 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
2439 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
2440 * the allocation is high priority and these type of
2441 * allocations are system rather than user orientated
2443 zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
2445 page
= __alloc_pages_high_priority(gfp_mask
, order
,
2446 zonelist
, high_zoneidx
, nodemask
,
2447 preferred_zone
, migratetype
);
2453 /* Atomic allocations - we can't balance anything */
2457 /* Avoid recursion of direct reclaim */
2458 if (current
->flags
& PF_MEMALLOC
)
2461 /* Avoid allocations with no watermarks from looping endlessly */
2462 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
2466 * Try direct compaction. The first pass is asynchronous. Subsequent
2467 * attempts after direct reclaim are synchronous
2469 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
2470 zonelist
, high_zoneidx
,
2472 alloc_flags
, preferred_zone
,
2473 migratetype
, sync_migration
,
2474 &contended_compaction
,
2475 &deferred_compaction
,
2476 &did_some_progress
);
2479 sync_migration
= true;
2482 * If compaction is deferred for high-order allocations, it is because
2483 * sync compaction recently failed. In this is the case and the caller
2484 * requested a movable allocation that does not heavily disrupt the
2485 * system then fail the allocation instead of entering direct reclaim.
2487 if ((deferred_compaction
|| contended_compaction
) &&
2488 (gfp_mask
& (__GFP_MOVABLE
|__GFP_REPEAT
)) == __GFP_MOVABLE
)
2491 /* Try direct reclaim and then allocating */
2492 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
,
2493 zonelist
, high_zoneidx
,
2495 alloc_flags
, preferred_zone
,
2496 migratetype
, &did_some_progress
);
2501 * If we failed to make any progress reclaiming, then we are
2502 * running out of options and have to consider going OOM
2504 if (!did_some_progress
) {
2505 if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
2506 if (oom_killer_disabled
)
2508 /* Coredumps can quickly deplete all memory reserves */
2509 if ((current
->flags
& PF_DUMPCORE
) &&
2510 !(gfp_mask
& __GFP_NOFAIL
))
2512 page
= __alloc_pages_may_oom(gfp_mask
, order
,
2513 zonelist
, high_zoneidx
,
2514 nodemask
, preferred_zone
,
2519 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2521 * The oom killer is not called for high-order
2522 * allocations that may fail, so if no progress
2523 * is being made, there are no other options and
2524 * retrying is unlikely to help.
2526 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2529 * The oom killer is not called for lowmem
2530 * allocations to prevent needlessly killing
2533 if (high_zoneidx
< ZONE_NORMAL
)
2541 /* Check if we should retry the allocation */
2542 pages_reclaimed
+= did_some_progress
;
2543 if (should_alloc_retry(gfp_mask
, order
, did_some_progress
,
2545 /* Wait for some write requests to complete then retry */
2546 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2550 * High-order allocations do not necessarily loop after
2551 * direct reclaim and reclaim/compaction depends on compaction
2552 * being called after reclaim so call directly if necessary
2554 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
2555 zonelist
, high_zoneidx
,
2557 alloc_flags
, preferred_zone
,
2558 migratetype
, sync_migration
,
2559 &contended_compaction
,
2560 &deferred_compaction
,
2561 &did_some_progress
);
2567 warn_alloc_failed(gfp_mask
, order
, NULL
);
2570 if (kmemcheck_enabled
)
2571 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
2577 * This is the 'heart' of the zoned buddy allocator.
2580 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
2581 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
2583 enum zone_type high_zoneidx
= gfp_zone(gfp_mask
);
2584 struct zone
*preferred_zone
;
2585 struct page
*page
= NULL
;
2586 int migratetype
= allocflags_to_migratetype(gfp_mask
);
2587 unsigned int cpuset_mems_cookie
;
2588 int alloc_flags
= ALLOC_WMARK_LOW
|ALLOC_CPUSET
;
2590 gfp_mask
&= gfp_allowed_mask
;
2592 lockdep_trace_alloc(gfp_mask
);
2594 might_sleep_if(gfp_mask
& __GFP_WAIT
);
2596 if (should_fail_alloc_page(gfp_mask
, order
))
2600 * Check the zones suitable for the gfp_mask contain at least one
2601 * valid zone. It's possible to have an empty zonelist as a result
2602 * of GFP_THISNODE and a memoryless node
2604 if (unlikely(!zonelist
->_zonerefs
->zone
))
2608 cpuset_mems_cookie
= get_mems_allowed();
2610 /* The preferred zone is used for statistics later */
2611 first_zones_zonelist(zonelist
, high_zoneidx
,
2612 nodemask
? : &cpuset_current_mems_allowed
,
2614 if (!preferred_zone
)
2618 if (allocflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
2619 alloc_flags
|= ALLOC_CMA
;
2621 /* First allocation attempt */
2622 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
, order
,
2623 zonelist
, high_zoneidx
, alloc_flags
,
2624 preferred_zone
, migratetype
);
2625 if (unlikely(!page
))
2626 page
= __alloc_pages_slowpath(gfp_mask
, order
,
2627 zonelist
, high_zoneidx
, nodemask
,
2628 preferred_zone
, migratetype
);
2630 trace_mm_page_alloc(page
, order
, gfp_mask
, migratetype
);
2634 * When updating a task's mems_allowed, it is possible to race with
2635 * parallel threads in such a way that an allocation can fail while
2636 * the mask is being updated. If a page allocation is about to fail,
2637 * check if the cpuset changed during allocation and if so, retry.
2639 if (unlikely(!put_mems_allowed(cpuset_mems_cookie
) && !page
))
2644 EXPORT_SYMBOL(__alloc_pages_nodemask
);
2647 * Common helper functions.
2649 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
2654 * __get_free_pages() returns a 32-bit address, which cannot represent
2657 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
2659 page
= alloc_pages(gfp_mask
, order
);
2662 return (unsigned long) page_address(page
);
2664 EXPORT_SYMBOL(__get_free_pages
);
2666 unsigned long get_zeroed_page(gfp_t gfp_mask
)
2668 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
2670 EXPORT_SYMBOL(get_zeroed_page
);
2672 void __free_pages(struct page
*page
, unsigned int order
)
2674 if (put_page_testzero(page
)) {
2676 free_hot_cold_page(page
, 0);
2678 __free_pages_ok(page
, order
);
2682 EXPORT_SYMBOL(__free_pages
);
2684 void free_pages(unsigned long addr
, unsigned int order
)
2687 VM_BUG_ON(!virt_addr_valid((void *)addr
));
2688 __free_pages(virt_to_page((void *)addr
), order
);
2692 EXPORT_SYMBOL(free_pages
);
2694 static void *make_alloc_exact(unsigned long addr
, unsigned order
, size_t size
)
2697 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
2698 unsigned long used
= addr
+ PAGE_ALIGN(size
);
2700 split_page(virt_to_page((void *)addr
), order
);
2701 while (used
< alloc_end
) {
2706 return (void *)addr
;
2710 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2711 * @size: the number of bytes to allocate
2712 * @gfp_mask: GFP flags for the allocation
2714 * This function is similar to alloc_pages(), except that it allocates the
2715 * minimum number of pages to satisfy the request. alloc_pages() can only
2716 * allocate memory in power-of-two pages.
2718 * This function is also limited by MAX_ORDER.
2720 * Memory allocated by this function must be released by free_pages_exact().
2722 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
2724 unsigned int order
= get_order(size
);
2727 addr
= __get_free_pages(gfp_mask
, order
);
2728 return make_alloc_exact(addr
, order
, size
);
2730 EXPORT_SYMBOL(alloc_pages_exact
);
2733 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
2735 * @nid: the preferred node ID where memory should be allocated
2736 * @size: the number of bytes to allocate
2737 * @gfp_mask: GFP flags for the allocation
2739 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
2741 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
2744 void *alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
2746 unsigned order
= get_order(size
);
2747 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
2750 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
2752 EXPORT_SYMBOL(alloc_pages_exact_nid
);
2755 * free_pages_exact - release memory allocated via alloc_pages_exact()
2756 * @virt: the value returned by alloc_pages_exact.
2757 * @size: size of allocation, same value as passed to alloc_pages_exact().
2759 * Release the memory allocated by a previous call to alloc_pages_exact.
2761 void free_pages_exact(void *virt
, size_t size
)
2763 unsigned long addr
= (unsigned long)virt
;
2764 unsigned long end
= addr
+ PAGE_ALIGN(size
);
2766 while (addr
< end
) {
2771 EXPORT_SYMBOL(free_pages_exact
);
2773 static unsigned int nr_free_zone_pages(int offset
)
2778 /* Just pick one node, since fallback list is circular */
2779 unsigned int sum
= 0;
2781 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
2783 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
2784 unsigned long size
= zone
->present_pages
;
2785 unsigned long high
= high_wmark_pages(zone
);
2794 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
2796 unsigned int nr_free_buffer_pages(void)
2798 return nr_free_zone_pages(gfp_zone(GFP_USER
));
2800 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
2803 * Amount of free RAM allocatable within all zones
2805 unsigned int nr_free_pagecache_pages(void)
2807 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
2810 static inline void show_node(struct zone
*zone
)
2813 printk("Node %d ", zone_to_nid(zone
));
2816 void si_meminfo(struct sysinfo
*val
)
2818 val
->totalram
= totalram_pages
;
2820 val
->freeram
= global_page_state(NR_FREE_PAGES
);
2821 val
->bufferram
= nr_blockdev_pages();
2822 val
->totalhigh
= totalhigh_pages
;
2823 val
->freehigh
= nr_free_highpages();
2824 val
->mem_unit
= PAGE_SIZE
;
2827 EXPORT_SYMBOL(si_meminfo
);
2830 void si_meminfo_node(struct sysinfo
*val
, int nid
)
2832 pg_data_t
*pgdat
= NODE_DATA(nid
);
2834 val
->totalram
= pgdat
->node_present_pages
;
2835 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
2836 #ifdef CONFIG_HIGHMEM
2837 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
2838 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
2844 val
->mem_unit
= PAGE_SIZE
;
2849 * Determine whether the node should be displayed or not, depending on whether
2850 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
2852 bool skip_free_areas_node(unsigned int flags
, int nid
)
2855 unsigned int cpuset_mems_cookie
;
2857 if (!(flags
& SHOW_MEM_FILTER_NODES
))
2861 cpuset_mems_cookie
= get_mems_allowed();
2862 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
2863 } while (!put_mems_allowed(cpuset_mems_cookie
));
2868 #define K(x) ((x) << (PAGE_SHIFT-10))
2871 * Show free area list (used inside shift_scroll-lock stuff)
2872 * We also calculate the percentage fragmentation. We do this by counting the
2873 * memory on each free list with the exception of the first item on the list.
2874 * Suppresses nodes that are not allowed by current's cpuset if
2875 * SHOW_MEM_FILTER_NODES is passed.
2877 void show_free_areas(unsigned int filter
)
2882 for_each_populated_zone(zone
) {
2883 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
2886 printk("%s per-cpu:\n", zone
->name
);
2888 for_each_online_cpu(cpu
) {
2889 struct per_cpu_pageset
*pageset
;
2891 pageset
= per_cpu_ptr(zone
->pageset
, cpu
);
2893 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
2894 cpu
, pageset
->pcp
.high
,
2895 pageset
->pcp
.batch
, pageset
->pcp
.count
);
2899 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
2900 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
2902 " dirty:%lu writeback:%lu unstable:%lu\n"
2903 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2904 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
2906 global_page_state(NR_ACTIVE_ANON
),
2907 global_page_state(NR_INACTIVE_ANON
),
2908 global_page_state(NR_ISOLATED_ANON
),
2909 global_page_state(NR_ACTIVE_FILE
),
2910 global_page_state(NR_INACTIVE_FILE
),
2911 global_page_state(NR_ISOLATED_FILE
),
2912 global_page_state(NR_UNEVICTABLE
),
2913 global_page_state(NR_FILE_DIRTY
),
2914 global_page_state(NR_WRITEBACK
),
2915 global_page_state(NR_UNSTABLE_NFS
),
2916 global_page_state(NR_FREE_PAGES
),
2917 global_page_state(NR_SLAB_RECLAIMABLE
),
2918 global_page_state(NR_SLAB_UNRECLAIMABLE
),
2919 global_page_state(NR_FILE_MAPPED
),
2920 global_page_state(NR_SHMEM
),
2921 global_page_state(NR_PAGETABLE
),
2922 global_page_state(NR_BOUNCE
),
2923 global_page_state(NR_FREE_CMA_PAGES
));
2925 for_each_populated_zone(zone
) {
2928 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
2936 " active_anon:%lukB"
2937 " inactive_anon:%lukB"
2938 " active_file:%lukB"
2939 " inactive_file:%lukB"
2940 " unevictable:%lukB"
2941 " isolated(anon):%lukB"
2942 " isolated(file):%lukB"
2949 " slab_reclaimable:%lukB"
2950 " slab_unreclaimable:%lukB"
2951 " kernel_stack:%lukB"
2956 " writeback_tmp:%lukB"
2957 " pages_scanned:%lu"
2958 " all_unreclaimable? %s"
2961 K(zone_page_state(zone
, NR_FREE_PAGES
)),
2962 K(min_wmark_pages(zone
)),
2963 K(low_wmark_pages(zone
)),
2964 K(high_wmark_pages(zone
)),
2965 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
2966 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
2967 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
2968 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
2969 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
2970 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
2971 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
2972 K(zone
->present_pages
),
2973 K(zone_page_state(zone
, NR_MLOCK
)),
2974 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
2975 K(zone_page_state(zone
, NR_WRITEBACK
)),
2976 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
2977 K(zone_page_state(zone
, NR_SHMEM
)),
2978 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
2979 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
2980 zone_page_state(zone
, NR_KERNEL_STACK
) *
2982 K(zone_page_state(zone
, NR_PAGETABLE
)),
2983 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
2984 K(zone_page_state(zone
, NR_BOUNCE
)),
2985 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)),
2986 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
2987 zone
->pages_scanned
,
2988 (zone
->all_unreclaimable
? "yes" : "no")
2990 printk("lowmem_reserve[]:");
2991 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
2992 printk(" %lu", zone
->lowmem_reserve
[i
]);
2996 for_each_populated_zone(zone
) {
2997 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
2999 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3002 printk("%s: ", zone
->name
);
3004 spin_lock_irqsave(&zone
->lock
, flags
);
3005 for (order
= 0; order
< MAX_ORDER
; order
++) {
3006 nr
[order
] = zone
->free_area
[order
].nr_free
;
3007 total
+= nr
[order
] << order
;
3009 spin_unlock_irqrestore(&zone
->lock
, flags
);
3010 for (order
= 0; order
< MAX_ORDER
; order
++)
3011 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
3012 printk("= %lukB\n", K(total
));
3015 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
3017 show_swap_cache_info();
3020 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
3022 zoneref
->zone
= zone
;
3023 zoneref
->zone_idx
= zone_idx(zone
);
3027 * Builds allocation fallback zone lists.
3029 * Add all populated zones of a node to the zonelist.
3031 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
3032 int nr_zones
, enum zone_type zone_type
)
3036 BUG_ON(zone_type
>= MAX_NR_ZONES
);
3041 zone
= pgdat
->node_zones
+ zone_type
;
3042 if (populated_zone(zone
)) {
3043 zoneref_set_zone(zone
,
3044 &zonelist
->_zonerefs
[nr_zones
++]);
3045 check_highest_zone(zone_type
);
3048 } while (zone_type
);
3055 * 0 = automatic detection of better ordering.
3056 * 1 = order by ([node] distance, -zonetype)
3057 * 2 = order by (-zonetype, [node] distance)
3059 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3060 * the same zonelist. So only NUMA can configure this param.
3062 #define ZONELIST_ORDER_DEFAULT 0
3063 #define ZONELIST_ORDER_NODE 1
3064 #define ZONELIST_ORDER_ZONE 2
3066 /* zonelist order in the kernel.
3067 * set_zonelist_order() will set this to NODE or ZONE.
3069 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3070 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
3074 /* The value user specified ....changed by config */
3075 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3076 /* string for sysctl */
3077 #define NUMA_ZONELIST_ORDER_LEN 16
3078 char numa_zonelist_order
[16] = "default";
3081 * interface for configure zonelist ordering.
3082 * command line option "numa_zonelist_order"
3083 * = "[dD]efault - default, automatic configuration.
3084 * = "[nN]ode - order by node locality, then by zone within node
3085 * = "[zZ]one - order by zone, then by locality within zone
3088 static int __parse_numa_zonelist_order(char *s
)
3090 if (*s
== 'd' || *s
== 'D') {
3091 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3092 } else if (*s
== 'n' || *s
== 'N') {
3093 user_zonelist_order
= ZONELIST_ORDER_NODE
;
3094 } else if (*s
== 'z' || *s
== 'Z') {
3095 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
3098 "Ignoring invalid numa_zonelist_order value: "
3105 static __init
int setup_numa_zonelist_order(char *s
)
3112 ret
= __parse_numa_zonelist_order(s
);
3114 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
3118 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
3121 * sysctl handler for numa_zonelist_order
3123 int numa_zonelist_order_handler(ctl_table
*table
, int write
,
3124 void __user
*buffer
, size_t *length
,
3127 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
3129 static DEFINE_MUTEX(zl_order_mutex
);
3131 mutex_lock(&zl_order_mutex
);
3133 strcpy(saved_string
, (char*)table
->data
);
3134 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
3138 int oldval
= user_zonelist_order
;
3139 if (__parse_numa_zonelist_order((char*)table
->data
)) {
3141 * bogus value. restore saved string
3143 strncpy((char*)table
->data
, saved_string
,
3144 NUMA_ZONELIST_ORDER_LEN
);
3145 user_zonelist_order
= oldval
;
3146 } else if (oldval
!= user_zonelist_order
) {
3147 mutex_lock(&zonelists_mutex
);
3148 build_all_zonelists(NULL
, NULL
);
3149 mutex_unlock(&zonelists_mutex
);
3153 mutex_unlock(&zl_order_mutex
);
3158 #define MAX_NODE_LOAD (nr_online_nodes)
3159 static int node_load
[MAX_NUMNODES
];
3162 * find_next_best_node - find the next node that should appear in a given node's fallback list
3163 * @node: node whose fallback list we're appending
3164 * @used_node_mask: nodemask_t of already used nodes
3166 * We use a number of factors to determine which is the next node that should
3167 * appear on a given node's fallback list. The node should not have appeared
3168 * already in @node's fallback list, and it should be the next closest node
3169 * according to the distance array (which contains arbitrary distance values
3170 * from each node to each node in the system), and should also prefer nodes
3171 * with no CPUs, since presumably they'll have very little allocation pressure
3172 * on them otherwise.
3173 * It returns -1 if no node is found.
3175 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
3178 int min_val
= INT_MAX
;
3180 const struct cpumask
*tmp
= cpumask_of_node(0);
3182 /* Use the local node if we haven't already */
3183 if (!node_isset(node
, *used_node_mask
)) {
3184 node_set(node
, *used_node_mask
);
3188 for_each_node_state(n
, N_HIGH_MEMORY
) {
3190 /* Don't want a node to appear more than once */
3191 if (node_isset(n
, *used_node_mask
))
3194 /* Use the distance array to find the distance */
3195 val
= node_distance(node
, n
);
3197 /* Penalize nodes under us ("prefer the next node") */
3200 /* Give preference to headless and unused nodes */
3201 tmp
= cpumask_of_node(n
);
3202 if (!cpumask_empty(tmp
))
3203 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
3205 /* Slight preference for less loaded node */
3206 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
3207 val
+= node_load
[n
];
3209 if (val
< min_val
) {
3216 node_set(best_node
, *used_node_mask
);
3223 * Build zonelists ordered by node and zones within node.
3224 * This results in maximum locality--normal zone overflows into local
3225 * DMA zone, if any--but risks exhausting DMA zone.
3227 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
3230 struct zonelist
*zonelist
;
3232 zonelist
= &pgdat
->node_zonelists
[0];
3233 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
3235 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3237 zonelist
->_zonerefs
[j
].zone
= NULL
;
3238 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3242 * Build gfp_thisnode zonelists
3244 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
3247 struct zonelist
*zonelist
;
3249 zonelist
= &pgdat
->node_zonelists
[1];
3250 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
3251 zonelist
->_zonerefs
[j
].zone
= NULL
;
3252 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3256 * Build zonelists ordered by zone and nodes within zones.
3257 * This results in conserving DMA zone[s] until all Normal memory is
3258 * exhausted, but results in overflowing to remote node while memory
3259 * may still exist in local DMA zone.
3261 static int node_order
[MAX_NUMNODES
];
3263 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
3266 int zone_type
; /* needs to be signed */
3268 struct zonelist
*zonelist
;
3270 zonelist
= &pgdat
->node_zonelists
[0];
3272 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
3273 for (j
= 0; j
< nr_nodes
; j
++) {
3274 node
= node_order
[j
];
3275 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
3276 if (populated_zone(z
)) {
3278 &zonelist
->_zonerefs
[pos
++]);
3279 check_highest_zone(zone_type
);
3283 zonelist
->_zonerefs
[pos
].zone
= NULL
;
3284 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
3287 static int default_zonelist_order(void)
3290 unsigned long low_kmem_size
,total_size
;
3294 * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
3295 * If they are really small and used heavily, the system can fall
3296 * into OOM very easily.
3297 * This function detect ZONE_DMA/DMA32 size and configures zone order.
3299 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
3302 for_each_online_node(nid
) {
3303 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
3304 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
3305 if (populated_zone(z
)) {
3306 if (zone_type
< ZONE_NORMAL
)
3307 low_kmem_size
+= z
->present_pages
;
3308 total_size
+= z
->present_pages
;
3309 } else if (zone_type
== ZONE_NORMAL
) {
3311 * If any node has only lowmem, then node order
3312 * is preferred to allow kernel allocations
3313 * locally; otherwise, they can easily infringe
3314 * on other nodes when there is an abundance of
3315 * lowmem available to allocate from.
3317 return ZONELIST_ORDER_NODE
;
3321 if (!low_kmem_size
|| /* there are no DMA area. */
3322 low_kmem_size
> total_size
/2) /* DMA/DMA32 is big. */
3323 return ZONELIST_ORDER_NODE
;
3325 * look into each node's config.
3326 * If there is a node whose DMA/DMA32 memory is very big area on
3327 * local memory, NODE_ORDER may be suitable.
3329 average_size
= total_size
/
3330 (nodes_weight(node_states
[N_HIGH_MEMORY
]) + 1);
3331 for_each_online_node(nid
) {
3334 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
3335 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
3336 if (populated_zone(z
)) {
3337 if (zone_type
< ZONE_NORMAL
)
3338 low_kmem_size
+= z
->present_pages
;
3339 total_size
+= z
->present_pages
;
3342 if (low_kmem_size
&&
3343 total_size
> average_size
&& /* ignore small node */
3344 low_kmem_size
> total_size
* 70/100)
3345 return ZONELIST_ORDER_NODE
;
3347 return ZONELIST_ORDER_ZONE
;
3350 static void set_zonelist_order(void)
3352 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
3353 current_zonelist_order
= default_zonelist_order();
3355 current_zonelist_order
= user_zonelist_order
;
3358 static void build_zonelists(pg_data_t
*pgdat
)
3362 nodemask_t used_mask
;
3363 int local_node
, prev_node
;
3364 struct zonelist
*zonelist
;
3365 int order
= current_zonelist_order
;
3367 /* initialize zonelists */
3368 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
3369 zonelist
= pgdat
->node_zonelists
+ i
;
3370 zonelist
->_zonerefs
[0].zone
= NULL
;
3371 zonelist
->_zonerefs
[0].zone_idx
= 0;
3374 /* NUMA-aware ordering of nodes */
3375 local_node
= pgdat
->node_id
;
3376 load
= nr_online_nodes
;
3377 prev_node
= local_node
;
3378 nodes_clear(used_mask
);
3380 memset(node_order
, 0, sizeof(node_order
));
3383 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
3384 int distance
= node_distance(local_node
, node
);
3387 * If another node is sufficiently far away then it is better
3388 * to reclaim pages in a zone before going off node.
3390 if (distance
> RECLAIM_DISTANCE
)
3391 zone_reclaim_mode
= 1;
3394 * We don't want to pressure a particular node.
3395 * So adding penalty to the first node in same
3396 * distance group to make it round-robin.
3398 if (distance
!= node_distance(local_node
, prev_node
))
3399 node_load
[node
] = load
;
3403 if (order
== ZONELIST_ORDER_NODE
)
3404 build_zonelists_in_node_order(pgdat
, node
);
3406 node_order
[j
++] = node
; /* remember order */
3409 if (order
== ZONELIST_ORDER_ZONE
) {
3410 /* calculate node order -- i.e., DMA last! */
3411 build_zonelists_in_zone_order(pgdat
, j
);
3414 build_thisnode_zonelists(pgdat
);
3417 /* Construct the zonelist performance cache - see further mmzone.h */
3418 static void build_zonelist_cache(pg_data_t
*pgdat
)
3420 struct zonelist
*zonelist
;
3421 struct zonelist_cache
*zlc
;
3424 zonelist
= &pgdat
->node_zonelists
[0];
3425 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
3426 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
3427 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
3428 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
3431 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3433 * Return node id of node used for "local" allocations.
3434 * I.e., first node id of first zone in arg node's generic zonelist.
3435 * Used for initializing percpu 'numa_mem', which is used primarily
3436 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3438 int local_memory_node(int node
)
3442 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
3443 gfp_zone(GFP_KERNEL
),
3450 #else /* CONFIG_NUMA */
3452 static void set_zonelist_order(void)
3454 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
3457 static void build_zonelists(pg_data_t
*pgdat
)
3459 int node
, local_node
;
3461 struct zonelist
*zonelist
;
3463 local_node
= pgdat
->node_id
;
3465 zonelist
= &pgdat
->node_zonelists
[0];
3466 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
3469 * Now we build the zonelist so that it contains the zones
3470 * of all the other nodes.
3471 * We don't want to pressure a particular node, so when
3472 * building the zones for node N, we make sure that the
3473 * zones coming right after the local ones are those from
3474 * node N+1 (modulo N)
3476 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
3477 if (!node_online(node
))
3479 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3482 for (node
= 0; node
< local_node
; node
++) {
3483 if (!node_online(node
))
3485 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3489 zonelist
->_zonerefs
[j
].zone
= NULL
;
3490 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3493 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3494 static void build_zonelist_cache(pg_data_t
*pgdat
)
3496 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
3499 #endif /* CONFIG_NUMA */
3502 * Boot pageset table. One per cpu which is going to be used for all
3503 * zones and all nodes. The parameters will be set in such a way
3504 * that an item put on a list will immediately be handed over to
3505 * the buddy list. This is safe since pageset manipulation is done
3506 * with interrupts disabled.
3508 * The boot_pagesets must be kept even after bootup is complete for
3509 * unused processors and/or zones. They do play a role for bootstrapping
3510 * hotplugged processors.
3512 * zoneinfo_show() and maybe other functions do
3513 * not check if the processor is online before following the pageset pointer.
3514 * Other parts of the kernel may not check if the zone is available.
3516 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
3517 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
3518 static void setup_zone_pageset(struct zone
*zone
);
3521 * Global mutex to protect against size modification of zonelists
3522 * as well as to serialize pageset setup for the new populated zone.
3524 DEFINE_MUTEX(zonelists_mutex
);
3526 /* return values int ....just for stop_machine() */
3527 static int __build_all_zonelists(void *data
)
3531 pg_data_t
*self
= data
;
3534 memset(node_load
, 0, sizeof(node_load
));
3537 if (self
&& !node_online(self
->node_id
)) {
3538 build_zonelists(self
);
3539 build_zonelist_cache(self
);
3542 for_each_online_node(nid
) {
3543 pg_data_t
*pgdat
= NODE_DATA(nid
);
3545 build_zonelists(pgdat
);
3546 build_zonelist_cache(pgdat
);
3550 * Initialize the boot_pagesets that are going to be used
3551 * for bootstrapping processors. The real pagesets for
3552 * each zone will be allocated later when the per cpu
3553 * allocator is available.
3555 * boot_pagesets are used also for bootstrapping offline
3556 * cpus if the system is already booted because the pagesets
3557 * are needed to initialize allocators on a specific cpu too.
3558 * F.e. the percpu allocator needs the page allocator which
3559 * needs the percpu allocator in order to allocate its pagesets
3560 * (a chicken-egg dilemma).
3562 for_each_possible_cpu(cpu
) {
3563 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
3565 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3567 * We now know the "local memory node" for each node--
3568 * i.e., the node of the first zone in the generic zonelist.
3569 * Set up numa_mem percpu variable for on-line cpus. During
3570 * boot, only the boot cpu should be on-line; we'll init the
3571 * secondary cpus' numa_mem as they come on-line. During
3572 * node/memory hotplug, we'll fixup all on-line cpus.
3574 if (cpu_online(cpu
))
3575 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
3583 * Called with zonelists_mutex held always
3584 * unless system_state == SYSTEM_BOOTING.
3586 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
3588 set_zonelist_order();
3590 if (system_state
== SYSTEM_BOOTING
) {
3591 __build_all_zonelists(NULL
);
3592 mminit_verify_zonelist();
3593 cpuset_init_current_mems_allowed();
3595 /* we have to stop all cpus to guarantee there is no user
3597 #ifdef CONFIG_MEMORY_HOTPLUG
3599 setup_zone_pageset(zone
);
3601 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
3602 /* cpuset refresh routine should be here */
3604 vm_total_pages
= nr_free_pagecache_pages();
3606 * Disable grouping by mobility if the number of pages in the
3607 * system is too low to allow the mechanism to work. It would be
3608 * more accurate, but expensive to check per-zone. This check is
3609 * made on memory-hotadd so a system can start with mobility
3610 * disabled and enable it later
3612 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
3613 page_group_by_mobility_disabled
= 1;
3615 page_group_by_mobility_disabled
= 0;
3617 printk("Built %i zonelists in %s order, mobility grouping %s. "
3618 "Total pages: %ld\n",
3620 zonelist_order_name
[current_zonelist_order
],
3621 page_group_by_mobility_disabled
? "off" : "on",
3624 printk("Policy zone: %s\n", zone_names
[policy_zone
]);
3629 * Helper functions to size the waitqueue hash table.
3630 * Essentially these want to choose hash table sizes sufficiently
3631 * large so that collisions trying to wait on pages are rare.
3632 * But in fact, the number of active page waitqueues on typical
3633 * systems is ridiculously low, less than 200. So this is even
3634 * conservative, even though it seems large.
3636 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3637 * waitqueues, i.e. the size of the waitq table given the number of pages.
3639 #define PAGES_PER_WAITQUEUE 256
3641 #ifndef CONFIG_MEMORY_HOTPLUG
3642 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3644 unsigned long size
= 1;
3646 pages
/= PAGES_PER_WAITQUEUE
;
3648 while (size
< pages
)
3652 * Once we have dozens or even hundreds of threads sleeping
3653 * on IO we've got bigger problems than wait queue collision.
3654 * Limit the size of the wait table to a reasonable size.
3656 size
= min(size
, 4096UL);
3658 return max(size
, 4UL);
3662 * A zone's size might be changed by hot-add, so it is not possible to determine
3663 * a suitable size for its wait_table. So we use the maximum size now.
3665 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
3667 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
3668 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3669 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
3671 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3672 * or more by the traditional way. (See above). It equals:
3674 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
3675 * ia64(16K page size) : = ( 8G + 4M)byte.
3676 * powerpc (64K page size) : = (32G +16M)byte.
3678 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3685 * This is an integer logarithm so that shifts can be used later
3686 * to extract the more random high bits from the multiplicative
3687 * hash function before the remainder is taken.
3689 static inline unsigned long wait_table_bits(unsigned long size
)
3694 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
3697 * Check if a pageblock contains reserved pages
3699 static int pageblock_is_reserved(unsigned long start_pfn
, unsigned long end_pfn
)
3703 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
3704 if (!pfn_valid_within(pfn
) || PageReserved(pfn_to_page(pfn
)))
3711 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3712 * of blocks reserved is based on min_wmark_pages(zone). The memory within
3713 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3714 * higher will lead to a bigger reserve which will get freed as contiguous
3715 * blocks as reclaim kicks in
3717 static void setup_zone_migrate_reserve(struct zone
*zone
)
3719 unsigned long start_pfn
, pfn
, end_pfn
, block_end_pfn
;
3721 unsigned long block_migratetype
;
3725 * Get the start pfn, end pfn and the number of blocks to reserve
3726 * We have to be careful to be aligned to pageblock_nr_pages to
3727 * make sure that we always check pfn_valid for the first page in
3730 start_pfn
= zone
->zone_start_pfn
;
3731 end_pfn
= start_pfn
+ zone
->spanned_pages
;
3732 start_pfn
= roundup(start_pfn
, pageblock_nr_pages
);
3733 reserve
= roundup(min_wmark_pages(zone
), pageblock_nr_pages
) >>
3737 * Reserve blocks are generally in place to help high-order atomic
3738 * allocations that are short-lived. A min_free_kbytes value that
3739 * would result in more than 2 reserve blocks for atomic allocations
3740 * is assumed to be in place to help anti-fragmentation for the
3741 * future allocation of hugepages at runtime.
3743 reserve
= min(2, reserve
);
3745 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
3746 if (!pfn_valid(pfn
))
3748 page
= pfn_to_page(pfn
);
3750 /* Watch out for overlapping nodes */
3751 if (page_to_nid(page
) != zone_to_nid(zone
))
3754 block_migratetype
= get_pageblock_migratetype(page
);
3756 /* Only test what is necessary when the reserves are not met */
3759 * Blocks with reserved pages will never free, skip
3762 block_end_pfn
= min(pfn
+ pageblock_nr_pages
, end_pfn
);
3763 if (pageblock_is_reserved(pfn
, block_end_pfn
))
3766 /* If this block is reserved, account for it */
3767 if (block_migratetype
== MIGRATE_RESERVE
) {
3772 /* Suitable for reserving if this block is movable */
3773 if (block_migratetype
== MIGRATE_MOVABLE
) {
3774 set_pageblock_migratetype(page
,
3776 move_freepages_block(zone
, page
,
3784 * If the reserve is met and this is a previous reserved block,
3787 if (block_migratetype
== MIGRATE_RESERVE
) {
3788 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3789 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
3795 * Initially all pages are reserved - free ones are freed
3796 * up by free_all_bootmem() once the early boot process is
3797 * done. Non-atomic initialization, single-pass.
3799 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
3800 unsigned long start_pfn
, enum memmap_context context
)
3803 unsigned long end_pfn
= start_pfn
+ size
;
3807 if (highest_memmap_pfn
< end_pfn
- 1)
3808 highest_memmap_pfn
= end_pfn
- 1;
3810 z
= &NODE_DATA(nid
)->node_zones
[zone
];
3811 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
3813 * There can be holes in boot-time mem_map[]s
3814 * handed to this function. They do not
3815 * exist on hotplugged memory.
3817 if (context
== MEMMAP_EARLY
) {
3818 if (!early_pfn_valid(pfn
))
3820 if (!early_pfn_in_nid(pfn
, nid
))
3823 page
= pfn_to_page(pfn
);
3824 set_page_links(page
, zone
, nid
, pfn
);
3825 mminit_verify_page_links(page
, zone
, nid
, pfn
);
3826 init_page_count(page
);
3827 reset_page_mapcount(page
);
3828 SetPageReserved(page
);
3830 * Mark the block movable so that blocks are reserved for
3831 * movable at startup. This will force kernel allocations
3832 * to reserve their blocks rather than leaking throughout
3833 * the address space during boot when many long-lived
3834 * kernel allocations are made. Later some blocks near
3835 * the start are marked MIGRATE_RESERVE by
3836 * setup_zone_migrate_reserve()
3838 * bitmap is created for zone's valid pfn range. but memmap
3839 * can be created for invalid pages (for alignment)
3840 * check here not to call set_pageblock_migratetype() against
3843 if ((z
->zone_start_pfn
<= pfn
)
3844 && (pfn
< z
->zone_start_pfn
+ z
->spanned_pages
)
3845 && !(pfn
& (pageblock_nr_pages
- 1)))
3846 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3848 INIT_LIST_HEAD(&page
->lru
);
3849 #ifdef WANT_PAGE_VIRTUAL
3850 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
3851 if (!is_highmem_idx(zone
))
3852 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
3857 static void __meminit
zone_init_free_lists(struct zone
*zone
)
3860 for_each_migratetype_order(order
, t
) {
3861 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
3862 zone
->free_area
[order
].nr_free
= 0;
3866 #ifndef __HAVE_ARCH_MEMMAP_INIT
3867 #define memmap_init(size, nid, zone, start_pfn) \
3868 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
3871 static int __meminit
zone_batchsize(struct zone
*zone
)
3877 * The per-cpu-pages pools are set to around 1000th of the
3878 * size of the zone. But no more than 1/2 of a meg.
3880 * OK, so we don't know how big the cache is. So guess.
3882 batch
= zone
->present_pages
/ 1024;
3883 if (batch
* PAGE_SIZE
> 512 * 1024)
3884 batch
= (512 * 1024) / PAGE_SIZE
;
3885 batch
/= 4; /* We effectively *= 4 below */
3890 * Clamp the batch to a 2^n - 1 value. Having a power
3891 * of 2 value was found to be more likely to have
3892 * suboptimal cache aliasing properties in some cases.
3894 * For example if 2 tasks are alternately allocating
3895 * batches of pages, one task can end up with a lot
3896 * of pages of one half of the possible page colors
3897 * and the other with pages of the other colors.
3899 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
3904 /* The deferral and batching of frees should be suppressed under NOMMU
3907 * The problem is that NOMMU needs to be able to allocate large chunks
3908 * of contiguous memory as there's no hardware page translation to
3909 * assemble apparent contiguous memory from discontiguous pages.
3911 * Queueing large contiguous runs of pages for batching, however,
3912 * causes the pages to actually be freed in smaller chunks. As there
3913 * can be a significant delay between the individual batches being
3914 * recycled, this leads to the once large chunks of space being
3915 * fragmented and becoming unavailable for high-order allocations.
3921 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
3923 struct per_cpu_pages
*pcp
;
3926 memset(p
, 0, sizeof(*p
));
3930 pcp
->high
= 6 * batch
;
3931 pcp
->batch
= max(1UL, 1 * batch
);
3932 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
3933 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
3937 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
3938 * to the value high for the pageset p.
3941 static void setup_pagelist_highmark(struct per_cpu_pageset
*p
,
3944 struct per_cpu_pages
*pcp
;
3948 pcp
->batch
= max(1UL, high
/4);
3949 if ((high
/4) > (PAGE_SHIFT
* 8))
3950 pcp
->batch
= PAGE_SHIFT
* 8;
3953 static void __meminit
setup_zone_pageset(struct zone
*zone
)
3957 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
3959 for_each_possible_cpu(cpu
) {
3960 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
3962 setup_pageset(pcp
, zone_batchsize(zone
));
3964 if (percpu_pagelist_fraction
)
3965 setup_pagelist_highmark(pcp
,
3966 (zone
->present_pages
/
3967 percpu_pagelist_fraction
));
3972 * Allocate per cpu pagesets and initialize them.
3973 * Before this call only boot pagesets were available.
3975 void __init
setup_per_cpu_pageset(void)
3979 for_each_populated_zone(zone
)
3980 setup_zone_pageset(zone
);
3983 static noinline __init_refok
3984 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
3987 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
3991 * The per-page waitqueue mechanism uses hashed waitqueues
3994 zone
->wait_table_hash_nr_entries
=
3995 wait_table_hash_nr_entries(zone_size_pages
);
3996 zone
->wait_table_bits
=
3997 wait_table_bits(zone
->wait_table_hash_nr_entries
);
3998 alloc_size
= zone
->wait_table_hash_nr_entries
3999 * sizeof(wait_queue_head_t
);
4001 if (!slab_is_available()) {
4002 zone
->wait_table
= (wait_queue_head_t
*)
4003 alloc_bootmem_node_nopanic(pgdat
, alloc_size
);
4006 * This case means that a zone whose size was 0 gets new memory
4007 * via memory hot-add.
4008 * But it may be the case that a new node was hot-added. In
4009 * this case vmalloc() will not be able to use this new node's
4010 * memory - this wait_table must be initialized to use this new
4011 * node itself as well.
4012 * To use this new node's memory, further consideration will be
4015 zone
->wait_table
= vmalloc(alloc_size
);
4017 if (!zone
->wait_table
)
4020 for(i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
4021 init_waitqueue_head(zone
->wait_table
+ i
);
4026 static __meminit
void zone_pcp_init(struct zone
*zone
)
4029 * per cpu subsystem is not up at this point. The following code
4030 * relies on the ability of the linker to provide the
4031 * offset of a (static) per cpu variable into the per cpu area.
4033 zone
->pageset
= &boot_pageset
;
4035 if (zone
->present_pages
)
4036 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
4037 zone
->name
, zone
->present_pages
,
4038 zone_batchsize(zone
));
4041 int __meminit
init_currently_empty_zone(struct zone
*zone
,
4042 unsigned long zone_start_pfn
,
4044 enum memmap_context context
)
4046 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
4048 ret
= zone_wait_table_init(zone
, size
);
4051 pgdat
->nr_zones
= zone_idx(zone
) + 1;
4053 zone
->zone_start_pfn
= zone_start_pfn
;
4055 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
4056 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4058 (unsigned long)zone_idx(zone
),
4059 zone_start_pfn
, (zone_start_pfn
+ size
));
4061 zone_init_free_lists(zone
);
4066 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4067 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4069 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4070 * Architectures may implement their own version but if add_active_range()
4071 * was used and there are no special requirements, this is a convenient
4074 int __meminit
__early_pfn_to_nid(unsigned long pfn
)
4076 unsigned long start_pfn
, end_pfn
;
4079 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
4080 if (start_pfn
<= pfn
&& pfn
< end_pfn
)
4082 /* This is a memory hole */
4085 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4087 int __meminit
early_pfn_to_nid(unsigned long pfn
)
4091 nid
= __early_pfn_to_nid(pfn
);
4094 /* just returns 0 */
4098 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
4099 bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
4103 nid
= __early_pfn_to_nid(pfn
);
4104 if (nid
>= 0 && nid
!= node
)
4111 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
4112 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4113 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
4115 * If an architecture guarantees that all ranges registered with
4116 * add_active_ranges() contain no holes and may be freed, this
4117 * this function may be used instead of calling free_bootmem() manually.
4119 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
4121 unsigned long start_pfn
, end_pfn
;
4124 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
4125 start_pfn
= min(start_pfn
, max_low_pfn
);
4126 end_pfn
= min(end_pfn
, max_low_pfn
);
4128 if (start_pfn
< end_pfn
)
4129 free_bootmem_node(NODE_DATA(this_nid
),
4130 PFN_PHYS(start_pfn
),
4131 (end_pfn
- start_pfn
) << PAGE_SHIFT
);
4136 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4137 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4139 * If an architecture guarantees that all ranges registered with
4140 * add_active_ranges() contain no holes and may be freed, this
4141 * function may be used instead of calling memory_present() manually.
4143 void __init
sparse_memory_present_with_active_regions(int nid
)
4145 unsigned long start_pfn
, end_pfn
;
4148 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
4149 memory_present(this_nid
, start_pfn
, end_pfn
);
4153 * get_pfn_range_for_nid - Return the start and end page frames for a node
4154 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4155 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
4156 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
4158 * It returns the start and end page frame of a node based on information
4159 * provided by an arch calling add_active_range(). If called for a node
4160 * with no available memory, a warning is printed and the start and end
4163 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
4164 unsigned long *start_pfn
, unsigned long *end_pfn
)
4166 unsigned long this_start_pfn
, this_end_pfn
;
4172 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
4173 *start_pfn
= min(*start_pfn
, this_start_pfn
);
4174 *end_pfn
= max(*end_pfn
, this_end_pfn
);
4177 if (*start_pfn
== -1UL)
4182 * This finds a zone that can be used for ZONE_MOVABLE pages. The
4183 * assumption is made that zones within a node are ordered in monotonic
4184 * increasing memory addresses so that the "highest" populated zone is used
4186 static void __init
find_usable_zone_for_movable(void)
4189 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
4190 if (zone_index
== ZONE_MOVABLE
)
4193 if (arch_zone_highest_possible_pfn
[zone_index
] >
4194 arch_zone_lowest_possible_pfn
[zone_index
])
4198 VM_BUG_ON(zone_index
== -1);
4199 movable_zone
= zone_index
;
4203 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4204 * because it is sized independent of architecture. Unlike the other zones,
4205 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4206 * in each node depending on the size of each node and how evenly kernelcore
4207 * is distributed. This helper function adjusts the zone ranges
4208 * provided by the architecture for a given node by using the end of the
4209 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4210 * zones within a node are in order of monotonic increases memory addresses
4212 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
4213 unsigned long zone_type
,
4214 unsigned long node_start_pfn
,
4215 unsigned long node_end_pfn
,
4216 unsigned long *zone_start_pfn
,
4217 unsigned long *zone_end_pfn
)
4219 /* Only adjust if ZONE_MOVABLE is on this node */
4220 if (zone_movable_pfn
[nid
]) {
4221 /* Size ZONE_MOVABLE */
4222 if (zone_type
== ZONE_MOVABLE
) {
4223 *zone_start_pfn
= zone_movable_pfn
[nid
];
4224 *zone_end_pfn
= min(node_end_pfn
,
4225 arch_zone_highest_possible_pfn
[movable_zone
]);
4227 /* Adjust for ZONE_MOVABLE starting within this range */
4228 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
4229 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
4230 *zone_end_pfn
= zone_movable_pfn
[nid
];
4232 /* Check if this whole range is within ZONE_MOVABLE */
4233 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
4234 *zone_start_pfn
= *zone_end_pfn
;
4239 * Return the number of pages a zone spans in a node, including holes
4240 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4242 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4243 unsigned long zone_type
,
4244 unsigned long *ignored
)
4246 unsigned long node_start_pfn
, node_end_pfn
;
4247 unsigned long zone_start_pfn
, zone_end_pfn
;
4249 /* Get the start and end of the node and zone */
4250 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
4251 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
4252 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
4253 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4254 node_start_pfn
, node_end_pfn
,
4255 &zone_start_pfn
, &zone_end_pfn
);
4257 /* Check that this node has pages within the zone's required range */
4258 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
4261 /* Move the zone boundaries inside the node if necessary */
4262 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
4263 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
4265 /* Return the spanned pages */
4266 return zone_end_pfn
- zone_start_pfn
;
4270 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4271 * then all holes in the requested range will be accounted for.
4273 unsigned long __meminit
__absent_pages_in_range(int nid
,
4274 unsigned long range_start_pfn
,
4275 unsigned long range_end_pfn
)
4277 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
4278 unsigned long start_pfn
, end_pfn
;
4281 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
4282 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
4283 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
4284 nr_absent
-= end_pfn
- start_pfn
;
4290 * absent_pages_in_range - Return number of page frames in holes within a range
4291 * @start_pfn: The start PFN to start searching for holes
4292 * @end_pfn: The end PFN to stop searching for holes
4294 * It returns the number of pages frames in memory holes within a range.
4296 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
4297 unsigned long end_pfn
)
4299 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
4302 /* Return the number of page frames in holes in a zone on a node */
4303 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4304 unsigned long zone_type
,
4305 unsigned long *ignored
)
4307 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
4308 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
4309 unsigned long node_start_pfn
, node_end_pfn
;
4310 unsigned long zone_start_pfn
, zone_end_pfn
;
4312 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
4313 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
4314 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
4316 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4317 node_start_pfn
, node_end_pfn
,
4318 &zone_start_pfn
, &zone_end_pfn
);
4319 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
4322 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4323 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4324 unsigned long zone_type
,
4325 unsigned long *zones_size
)
4327 return zones_size
[zone_type
];
4330 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4331 unsigned long zone_type
,
4332 unsigned long *zholes_size
)
4337 return zholes_size
[zone_type
];
4340 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4342 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
4343 unsigned long *zones_size
, unsigned long *zholes_size
)
4345 unsigned long realtotalpages
, totalpages
= 0;
4348 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4349 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
4351 pgdat
->node_spanned_pages
= totalpages
;
4353 realtotalpages
= totalpages
;
4354 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4356 zone_absent_pages_in_node(pgdat
->node_id
, i
,
4358 pgdat
->node_present_pages
= realtotalpages
;
4359 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
4363 #ifndef CONFIG_SPARSEMEM
4365 * Calculate the size of the zone->blockflags rounded to an unsigned long
4366 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4367 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4368 * round what is now in bits to nearest long in bits, then return it in
4371 static unsigned long __init
usemap_size(unsigned long zonesize
)
4373 unsigned long usemapsize
;
4375 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
4376 usemapsize
= usemapsize
>> pageblock_order
;
4377 usemapsize
*= NR_PAGEBLOCK_BITS
;
4378 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
4380 return usemapsize
/ 8;
4383 static void __init
setup_usemap(struct pglist_data
*pgdat
,
4384 struct zone
*zone
, unsigned long zonesize
)
4386 unsigned long usemapsize
= usemap_size(zonesize
);
4387 zone
->pageblock_flags
= NULL
;
4389 zone
->pageblock_flags
= alloc_bootmem_node_nopanic(pgdat
,
4393 static inline void setup_usemap(struct pglist_data
*pgdat
,
4394 struct zone
*zone
, unsigned long zonesize
) {}
4395 #endif /* CONFIG_SPARSEMEM */
4397 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4399 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4400 void __init
set_pageblock_order(void)
4404 /* Check that pageblock_nr_pages has not already been setup */
4405 if (pageblock_order
)
4408 if (HPAGE_SHIFT
> PAGE_SHIFT
)
4409 order
= HUGETLB_PAGE_ORDER
;
4411 order
= MAX_ORDER
- 1;
4414 * Assume the largest contiguous order of interest is a huge page.
4415 * This value may be variable depending on boot parameters on IA64 and
4418 pageblock_order
= order
;
4420 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4423 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4424 * is unused as pageblock_order is set at compile-time. See
4425 * include/linux/pageblock-flags.h for the values of pageblock_order based on
4428 void __init
set_pageblock_order(void)
4432 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4435 * Set up the zone data structures:
4436 * - mark all pages reserved
4437 * - mark all memory queues empty
4438 * - clear the memory bitmaps
4440 * NOTE: pgdat should get zeroed by caller.
4442 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
,
4443 unsigned long *zones_size
, unsigned long *zholes_size
)
4446 int nid
= pgdat
->node_id
;
4447 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
4450 pgdat_resize_init(pgdat
);
4451 init_waitqueue_head(&pgdat
->kswapd_wait
);
4452 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
4453 pgdat_page_cgroup_init(pgdat
);
4455 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4456 struct zone
*zone
= pgdat
->node_zones
+ j
;
4457 unsigned long size
, realsize
, memmap_pages
;
4459 size
= zone_spanned_pages_in_node(nid
, j
, zones_size
);
4460 realsize
= size
- zone_absent_pages_in_node(nid
, j
,
4464 * Adjust realsize so that it accounts for how much memory
4465 * is used by this zone for memmap. This affects the watermark
4466 * and per-cpu initialisations
4469 PAGE_ALIGN(size
* sizeof(struct page
)) >> PAGE_SHIFT
;
4470 if (realsize
>= memmap_pages
) {
4471 realsize
-= memmap_pages
;
4474 " %s zone: %lu pages used for memmap\n",
4475 zone_names
[j
], memmap_pages
);
4478 " %s zone: %lu pages exceeds realsize %lu\n",
4479 zone_names
[j
], memmap_pages
, realsize
);
4481 /* Account for reserved pages */
4482 if (j
== 0 && realsize
> dma_reserve
) {
4483 realsize
-= dma_reserve
;
4484 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
4485 zone_names
[0], dma_reserve
);
4488 if (!is_highmem_idx(j
))
4489 nr_kernel_pages
+= realsize
;
4490 nr_all_pages
+= realsize
;
4492 zone
->spanned_pages
= size
;
4493 zone
->present_pages
= realsize
;
4496 zone
->min_unmapped_pages
= (realsize
*sysctl_min_unmapped_ratio
)
4498 zone
->min_slab_pages
= (realsize
* sysctl_min_slab_ratio
) / 100;
4500 zone
->name
= zone_names
[j
];
4501 spin_lock_init(&zone
->lock
);
4502 spin_lock_init(&zone
->lru_lock
);
4503 zone_seqlock_init(zone
);
4504 zone
->zone_pgdat
= pgdat
;
4506 zone_pcp_init(zone
);
4507 lruvec_init(&zone
->lruvec
, zone
);
4511 set_pageblock_order();
4512 setup_usemap(pgdat
, zone
, size
);
4513 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
4514 size
, MEMMAP_EARLY
);
4516 memmap_init(size
, nid
, j
, zone_start_pfn
);
4517 zone_start_pfn
+= size
;
4521 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
4523 /* Skip empty nodes */
4524 if (!pgdat
->node_spanned_pages
)
4527 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4528 /* ia64 gets its own node_mem_map, before this, without bootmem */
4529 if (!pgdat
->node_mem_map
) {
4530 unsigned long size
, start
, end
;
4534 * The zone's endpoints aren't required to be MAX_ORDER
4535 * aligned but the node_mem_map endpoints must be in order
4536 * for the buddy allocator to function correctly.
4538 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
4539 end
= pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
4540 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
4541 size
= (end
- start
) * sizeof(struct page
);
4542 map
= alloc_remap(pgdat
->node_id
, size
);
4544 map
= alloc_bootmem_node_nopanic(pgdat
, size
);
4545 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
4547 #ifndef CONFIG_NEED_MULTIPLE_NODES
4549 * With no DISCONTIG, the global mem_map is just set as node 0's
4551 if (pgdat
== NODE_DATA(0)) {
4552 mem_map
= NODE_DATA(0)->node_mem_map
;
4553 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4554 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
4555 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
4556 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4559 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4562 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
4563 unsigned long node_start_pfn
, unsigned long *zholes_size
)
4565 pg_data_t
*pgdat
= NODE_DATA(nid
);
4567 /* pg_data_t should be reset to zero when it's allocated */
4568 WARN_ON(pgdat
->nr_zones
|| pgdat
->classzone_idx
);
4570 pgdat
->node_id
= nid
;
4571 pgdat
->node_start_pfn
= node_start_pfn
;
4572 calculate_node_totalpages(pgdat
, zones_size
, zholes_size
);
4574 alloc_node_mem_map(pgdat
);
4575 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4576 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
4577 nid
, (unsigned long)pgdat
,
4578 (unsigned long)pgdat
->node_mem_map
);
4581 free_area_init_core(pgdat
, zones_size
, zholes_size
);
4584 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4586 #if MAX_NUMNODES > 1
4588 * Figure out the number of possible node ids.
4590 static void __init
setup_nr_node_ids(void)
4593 unsigned int highest
= 0;
4595 for_each_node_mask(node
, node_possible_map
)
4597 nr_node_ids
= highest
+ 1;
4600 static inline void setup_nr_node_ids(void)
4606 * node_map_pfn_alignment - determine the maximum internode alignment
4608 * This function should be called after node map is populated and sorted.
4609 * It calculates the maximum power of two alignment which can distinguish
4612 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
4613 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
4614 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
4615 * shifted, 1GiB is enough and this function will indicate so.
4617 * This is used to test whether pfn -> nid mapping of the chosen memory
4618 * model has fine enough granularity to avoid incorrect mapping for the
4619 * populated node map.
4621 * Returns the determined alignment in pfn's. 0 if there is no alignment
4622 * requirement (single node).
4624 unsigned long __init
node_map_pfn_alignment(void)
4626 unsigned long accl_mask
= 0, last_end
= 0;
4627 unsigned long start
, end
, mask
;
4631 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
4632 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
4639 * Start with a mask granular enough to pin-point to the
4640 * start pfn and tick off bits one-by-one until it becomes
4641 * too coarse to separate the current node from the last.
4643 mask
= ~((1 << __ffs(start
)) - 1);
4644 while (mask
&& last_end
<= (start
& (mask
<< 1)))
4647 /* accumulate all internode masks */
4651 /* convert mask to number of pages */
4652 return ~accl_mask
+ 1;
4655 /* Find the lowest pfn for a node */
4656 static unsigned long __init
find_min_pfn_for_node(int nid
)
4658 unsigned long min_pfn
= ULONG_MAX
;
4659 unsigned long start_pfn
;
4662 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
4663 min_pfn
= min(min_pfn
, start_pfn
);
4665 if (min_pfn
== ULONG_MAX
) {
4667 "Could not find start_pfn for node %d\n", nid
);
4675 * find_min_pfn_with_active_regions - Find the minimum PFN registered
4677 * It returns the minimum PFN based on information provided via
4678 * add_active_range().
4680 unsigned long __init
find_min_pfn_with_active_regions(void)
4682 return find_min_pfn_for_node(MAX_NUMNODES
);
4686 * early_calculate_totalpages()
4687 * Sum pages in active regions for movable zone.
4688 * Populate N_HIGH_MEMORY for calculating usable_nodes.
4690 static unsigned long __init
early_calculate_totalpages(void)
4692 unsigned long totalpages
= 0;
4693 unsigned long start_pfn
, end_pfn
;
4696 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
4697 unsigned long pages
= end_pfn
- start_pfn
;
4699 totalpages
+= pages
;
4701 node_set_state(nid
, N_HIGH_MEMORY
);
4707 * Find the PFN the Movable zone begins in each node. Kernel memory
4708 * is spread evenly between nodes as long as the nodes have enough
4709 * memory. When they don't, some nodes will have more kernelcore than
4712 static void __init
find_zone_movable_pfns_for_nodes(void)
4715 unsigned long usable_startpfn
;
4716 unsigned long kernelcore_node
, kernelcore_remaining
;
4717 /* save the state before borrow the nodemask */
4718 nodemask_t saved_node_state
= node_states
[N_HIGH_MEMORY
];
4719 unsigned long totalpages
= early_calculate_totalpages();
4720 int usable_nodes
= nodes_weight(node_states
[N_HIGH_MEMORY
]);
4723 * If movablecore was specified, calculate what size of
4724 * kernelcore that corresponds so that memory usable for
4725 * any allocation type is evenly spread. If both kernelcore
4726 * and movablecore are specified, then the value of kernelcore
4727 * will be used for required_kernelcore if it's greater than
4728 * what movablecore would have allowed.
4730 if (required_movablecore
) {
4731 unsigned long corepages
;
4734 * Round-up so that ZONE_MOVABLE is at least as large as what
4735 * was requested by the user
4737 required_movablecore
=
4738 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
4739 corepages
= totalpages
- required_movablecore
;
4741 required_kernelcore
= max(required_kernelcore
, corepages
);
4744 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
4745 if (!required_kernelcore
)
4748 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
4749 find_usable_zone_for_movable();
4750 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
4753 /* Spread kernelcore memory as evenly as possible throughout nodes */
4754 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4755 for_each_node_state(nid
, N_HIGH_MEMORY
) {
4756 unsigned long start_pfn
, end_pfn
;
4759 * Recalculate kernelcore_node if the division per node
4760 * now exceeds what is necessary to satisfy the requested
4761 * amount of memory for the kernel
4763 if (required_kernelcore
< kernelcore_node
)
4764 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4767 * As the map is walked, we track how much memory is usable
4768 * by the kernel using kernelcore_remaining. When it is
4769 * 0, the rest of the node is usable by ZONE_MOVABLE
4771 kernelcore_remaining
= kernelcore_node
;
4773 /* Go through each range of PFNs within this node */
4774 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
4775 unsigned long size_pages
;
4777 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
4778 if (start_pfn
>= end_pfn
)
4781 /* Account for what is only usable for kernelcore */
4782 if (start_pfn
< usable_startpfn
) {
4783 unsigned long kernel_pages
;
4784 kernel_pages
= min(end_pfn
, usable_startpfn
)
4787 kernelcore_remaining
-= min(kernel_pages
,
4788 kernelcore_remaining
);
4789 required_kernelcore
-= min(kernel_pages
,
4790 required_kernelcore
);
4792 /* Continue if range is now fully accounted */
4793 if (end_pfn
<= usable_startpfn
) {
4796 * Push zone_movable_pfn to the end so
4797 * that if we have to rebalance
4798 * kernelcore across nodes, we will
4799 * not double account here
4801 zone_movable_pfn
[nid
] = end_pfn
;
4804 start_pfn
= usable_startpfn
;
4808 * The usable PFN range for ZONE_MOVABLE is from
4809 * start_pfn->end_pfn. Calculate size_pages as the
4810 * number of pages used as kernelcore
4812 size_pages
= end_pfn
- start_pfn
;
4813 if (size_pages
> kernelcore_remaining
)
4814 size_pages
= kernelcore_remaining
;
4815 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
4818 * Some kernelcore has been met, update counts and
4819 * break if the kernelcore for this node has been
4822 required_kernelcore
-= min(required_kernelcore
,
4824 kernelcore_remaining
-= size_pages
;
4825 if (!kernelcore_remaining
)
4831 * If there is still required_kernelcore, we do another pass with one
4832 * less node in the count. This will push zone_movable_pfn[nid] further
4833 * along on the nodes that still have memory until kernelcore is
4837 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
4840 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
4841 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
4842 zone_movable_pfn
[nid
] =
4843 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
4846 /* restore the node_state */
4847 node_states
[N_HIGH_MEMORY
] = saved_node_state
;
4850 /* Any regular memory on that node ? */
4851 static void __init
check_for_regular_memory(pg_data_t
*pgdat
)
4853 #ifdef CONFIG_HIGHMEM
4854 enum zone_type zone_type
;
4856 for (zone_type
= 0; zone_type
<= ZONE_NORMAL
; zone_type
++) {
4857 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4858 if (zone
->present_pages
) {
4859 node_set_state(zone_to_nid(zone
), N_NORMAL_MEMORY
);
4867 * free_area_init_nodes - Initialise all pg_data_t and zone data
4868 * @max_zone_pfn: an array of max PFNs for each zone
4870 * This will call free_area_init_node() for each active node in the system.
4871 * Using the page ranges provided by add_active_range(), the size of each
4872 * zone in each node and their holes is calculated. If the maximum PFN
4873 * between two adjacent zones match, it is assumed that the zone is empty.
4874 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
4875 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
4876 * starts where the previous one ended. For example, ZONE_DMA32 starts
4877 * at arch_max_dma_pfn.
4879 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
4881 unsigned long start_pfn
, end_pfn
;
4884 /* Record where the zone boundaries are */
4885 memset(arch_zone_lowest_possible_pfn
, 0,
4886 sizeof(arch_zone_lowest_possible_pfn
));
4887 memset(arch_zone_highest_possible_pfn
, 0,
4888 sizeof(arch_zone_highest_possible_pfn
));
4889 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
4890 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
4891 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
4892 if (i
== ZONE_MOVABLE
)
4894 arch_zone_lowest_possible_pfn
[i
] =
4895 arch_zone_highest_possible_pfn
[i
-1];
4896 arch_zone_highest_possible_pfn
[i
] =
4897 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
4899 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
4900 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
4902 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
4903 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
4904 find_zone_movable_pfns_for_nodes();
4906 /* Print out the zone ranges */
4907 printk("Zone ranges:\n");
4908 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4909 if (i
== ZONE_MOVABLE
)
4911 printk(KERN_CONT
" %-8s ", zone_names
[i
]);
4912 if (arch_zone_lowest_possible_pfn
[i
] ==
4913 arch_zone_highest_possible_pfn
[i
])
4914 printk(KERN_CONT
"empty\n");
4916 printk(KERN_CONT
"[mem %0#10lx-%0#10lx]\n",
4917 arch_zone_lowest_possible_pfn
[i
] << PAGE_SHIFT
,
4918 (arch_zone_highest_possible_pfn
[i
]
4919 << PAGE_SHIFT
) - 1);
4922 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
4923 printk("Movable zone start for each node\n");
4924 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
4925 if (zone_movable_pfn
[i
])
4926 printk(" Node %d: %#010lx\n", i
,
4927 zone_movable_pfn
[i
] << PAGE_SHIFT
);
4930 /* Print out the early node map */
4931 printk("Early memory node ranges\n");
4932 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
4933 printk(" node %3d: [mem %#010lx-%#010lx]\n", nid
,
4934 start_pfn
<< PAGE_SHIFT
, (end_pfn
<< PAGE_SHIFT
) - 1);
4936 /* Initialise every node */
4937 mminit_verify_pageflags_layout();
4938 setup_nr_node_ids();
4939 for_each_online_node(nid
) {
4940 pg_data_t
*pgdat
= NODE_DATA(nid
);
4941 free_area_init_node(nid
, NULL
,
4942 find_min_pfn_for_node(nid
), NULL
);
4944 /* Any memory on that node */
4945 if (pgdat
->node_present_pages
)
4946 node_set_state(nid
, N_HIGH_MEMORY
);
4947 check_for_regular_memory(pgdat
);
4951 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
4953 unsigned long long coremem
;
4957 coremem
= memparse(p
, &p
);
4958 *core
= coremem
>> PAGE_SHIFT
;
4960 /* Paranoid check that UL is enough for the coremem value */
4961 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
4967 * kernelcore=size sets the amount of memory for use for allocations that
4968 * cannot be reclaimed or migrated.
4970 static int __init
cmdline_parse_kernelcore(char *p
)
4972 return cmdline_parse_core(p
, &required_kernelcore
);
4976 * movablecore=size sets the amount of memory for use for allocations that
4977 * can be reclaimed or migrated.
4979 static int __init
cmdline_parse_movablecore(char *p
)
4981 return cmdline_parse_core(p
, &required_movablecore
);
4984 early_param("kernelcore", cmdline_parse_kernelcore
);
4985 early_param("movablecore", cmdline_parse_movablecore
);
4987 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4990 * set_dma_reserve - set the specified number of pages reserved in the first zone
4991 * @new_dma_reserve: The number of pages to mark reserved
4993 * The per-cpu batchsize and zone watermarks are determined by present_pages.
4994 * In the DMA zone, a significant percentage may be consumed by kernel image
4995 * and other unfreeable allocations which can skew the watermarks badly. This
4996 * function may optionally be used to account for unfreeable pages in the
4997 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
4998 * smaller per-cpu batchsize.
5000 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
5002 dma_reserve
= new_dma_reserve
;
5005 void __init
free_area_init(unsigned long *zones_size
)
5007 free_area_init_node(0, zones_size
,
5008 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
5011 static int page_alloc_cpu_notify(struct notifier_block
*self
,
5012 unsigned long action
, void *hcpu
)
5014 int cpu
= (unsigned long)hcpu
;
5016 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
5017 lru_add_drain_cpu(cpu
);
5021 * Spill the event counters of the dead processor
5022 * into the current processors event counters.
5023 * This artificially elevates the count of the current
5026 vm_events_fold_cpu(cpu
);
5029 * Zero the differential counters of the dead processor
5030 * so that the vm statistics are consistent.
5032 * This is only okay since the processor is dead and cannot
5033 * race with what we are doing.
5035 refresh_cpu_vm_stats(cpu
);
5040 void __init
page_alloc_init(void)
5042 hotcpu_notifier(page_alloc_cpu_notify
, 0);
5046 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
5047 * or min_free_kbytes changes.
5049 static void calculate_totalreserve_pages(void)
5051 struct pglist_data
*pgdat
;
5052 unsigned long reserve_pages
= 0;
5053 enum zone_type i
, j
;
5055 for_each_online_pgdat(pgdat
) {
5056 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5057 struct zone
*zone
= pgdat
->node_zones
+ i
;
5058 unsigned long max
= 0;
5060 /* Find valid and maximum lowmem_reserve in the zone */
5061 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
5062 if (zone
->lowmem_reserve
[j
] > max
)
5063 max
= zone
->lowmem_reserve
[j
];
5066 /* we treat the high watermark as reserved pages. */
5067 max
+= high_wmark_pages(zone
);
5069 if (max
> zone
->present_pages
)
5070 max
= zone
->present_pages
;
5071 reserve_pages
+= max
;
5073 * Lowmem reserves are not available to
5074 * GFP_HIGHUSER page cache allocations and
5075 * kswapd tries to balance zones to their high
5076 * watermark. As a result, neither should be
5077 * regarded as dirtyable memory, to prevent a
5078 * situation where reclaim has to clean pages
5079 * in order to balance the zones.
5081 zone
->dirty_balance_reserve
= max
;
5084 dirty_balance_reserve
= reserve_pages
;
5085 totalreserve_pages
= reserve_pages
;
5089 * setup_per_zone_lowmem_reserve - called whenever
5090 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
5091 * has a correct pages reserved value, so an adequate number of
5092 * pages are left in the zone after a successful __alloc_pages().
5094 static void setup_per_zone_lowmem_reserve(void)
5096 struct pglist_data
*pgdat
;
5097 enum zone_type j
, idx
;
5099 for_each_online_pgdat(pgdat
) {
5100 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5101 struct zone
*zone
= pgdat
->node_zones
+ j
;
5102 unsigned long present_pages
= zone
->present_pages
;
5104 zone
->lowmem_reserve
[j
] = 0;
5108 struct zone
*lower_zone
;
5112 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
5113 sysctl_lowmem_reserve_ratio
[idx
] = 1;
5115 lower_zone
= pgdat
->node_zones
+ idx
;
5116 lower_zone
->lowmem_reserve
[j
] = present_pages
/
5117 sysctl_lowmem_reserve_ratio
[idx
];
5118 present_pages
+= lower_zone
->present_pages
;
5123 /* update totalreserve_pages */
5124 calculate_totalreserve_pages();
5127 static void __setup_per_zone_wmarks(void)
5129 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
5130 unsigned long lowmem_pages
= 0;
5132 unsigned long flags
;
5134 /* Calculate total number of !ZONE_HIGHMEM pages */
5135 for_each_zone(zone
) {
5136 if (!is_highmem(zone
))
5137 lowmem_pages
+= zone
->present_pages
;
5140 for_each_zone(zone
) {
5143 spin_lock_irqsave(&zone
->lock
, flags
);
5144 tmp
= (u64
)pages_min
* zone
->present_pages
;
5145 do_div(tmp
, lowmem_pages
);
5146 if (is_highmem(zone
)) {
5148 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
5149 * need highmem pages, so cap pages_min to a small
5152 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
5153 * deltas controls asynch page reclaim, and so should
5154 * not be capped for highmem.
5158 min_pages
= zone
->present_pages
/ 1024;
5159 if (min_pages
< SWAP_CLUSTER_MAX
)
5160 min_pages
= SWAP_CLUSTER_MAX
;
5161 if (min_pages
> 128)
5163 zone
->watermark
[WMARK_MIN
] = min_pages
;
5166 * If it's a lowmem zone, reserve a number of pages
5167 * proportionate to the zone's size.
5169 zone
->watermark
[WMARK_MIN
] = tmp
;
5172 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + (tmp
>> 2);
5173 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + (tmp
>> 1);
5175 zone
->watermark
[WMARK_MIN
] += cma_wmark_pages(zone
);
5176 zone
->watermark
[WMARK_LOW
] += cma_wmark_pages(zone
);
5177 zone
->watermark
[WMARK_HIGH
] += cma_wmark_pages(zone
);
5179 setup_zone_migrate_reserve(zone
);
5180 spin_unlock_irqrestore(&zone
->lock
, flags
);
5183 /* update totalreserve_pages */
5184 calculate_totalreserve_pages();
5188 * setup_per_zone_wmarks - called when min_free_kbytes changes
5189 * or when memory is hot-{added|removed}
5191 * Ensures that the watermark[min,low,high] values for each zone are set
5192 * correctly with respect to min_free_kbytes.
5194 void setup_per_zone_wmarks(void)
5196 mutex_lock(&zonelists_mutex
);
5197 __setup_per_zone_wmarks();
5198 mutex_unlock(&zonelists_mutex
);
5202 * The inactive anon list should be small enough that the VM never has to
5203 * do too much work, but large enough that each inactive page has a chance
5204 * to be referenced again before it is swapped out.
5206 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
5207 * INACTIVE_ANON pages on this zone's LRU, maintained by the
5208 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
5209 * the anonymous pages are kept on the inactive list.
5212 * memory ratio inactive anon
5213 * -------------------------------------
5222 static void __meminit
calculate_zone_inactive_ratio(struct zone
*zone
)
5224 unsigned int gb
, ratio
;
5226 /* Zone size in gigabytes */
5227 gb
= zone
->present_pages
>> (30 - PAGE_SHIFT
);
5229 ratio
= int_sqrt(10 * gb
);
5233 zone
->inactive_ratio
= ratio
;
5236 static void __meminit
setup_per_zone_inactive_ratio(void)
5241 calculate_zone_inactive_ratio(zone
);
5245 * Initialise min_free_kbytes.
5247 * For small machines we want it small (128k min). For large machines
5248 * we want it large (64MB max). But it is not linear, because network
5249 * bandwidth does not increase linearly with machine size. We use
5251 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5252 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
5268 int __meminit
init_per_zone_wmark_min(void)
5270 unsigned long lowmem_kbytes
;
5272 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
5274 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
5275 if (min_free_kbytes
< 128)
5276 min_free_kbytes
= 128;
5277 if (min_free_kbytes
> 65536)
5278 min_free_kbytes
= 65536;
5279 setup_per_zone_wmarks();
5280 refresh_zone_stat_thresholds();
5281 setup_per_zone_lowmem_reserve();
5282 setup_per_zone_inactive_ratio();
5285 module_init(init_per_zone_wmark_min
)
5288 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5289 * that we can call two helper functions whenever min_free_kbytes
5292 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
5293 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5295 proc_dointvec(table
, write
, buffer
, length
, ppos
);
5297 setup_per_zone_wmarks();
5302 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
5303 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5308 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5313 zone
->min_unmapped_pages
= (zone
->present_pages
*
5314 sysctl_min_unmapped_ratio
) / 100;
5318 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
5319 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5324 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5329 zone
->min_slab_pages
= (zone
->present_pages
*
5330 sysctl_min_slab_ratio
) / 100;
5336 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5337 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5338 * whenever sysctl_lowmem_reserve_ratio changes.
5340 * The reserve ratio obviously has absolutely no relation with the
5341 * minimum watermarks. The lowmem reserve ratio can only make sense
5342 * if in function of the boot time zone sizes.
5344 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
5345 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5347 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5348 setup_per_zone_lowmem_reserve();
5353 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5354 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
5355 * can have before it gets flushed back to buddy allocator.
5358 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
5359 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5365 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5366 if (!write
|| (ret
< 0))
5368 for_each_populated_zone(zone
) {
5369 for_each_possible_cpu(cpu
) {
5371 high
= zone
->present_pages
/ percpu_pagelist_fraction
;
5372 setup_pagelist_highmark(
5373 per_cpu_ptr(zone
->pageset
, cpu
), high
);
5379 int hashdist
= HASHDIST_DEFAULT
;
5382 static int __init
set_hashdist(char *str
)
5386 hashdist
= simple_strtoul(str
, &str
, 0);
5389 __setup("hashdist=", set_hashdist
);
5393 * allocate a large system hash table from bootmem
5394 * - it is assumed that the hash table must contain an exact power-of-2
5395 * quantity of entries
5396 * - limit is the number of hash buckets, not the total allocation size
5398 void *__init
alloc_large_system_hash(const char *tablename
,
5399 unsigned long bucketsize
,
5400 unsigned long numentries
,
5403 unsigned int *_hash_shift
,
5404 unsigned int *_hash_mask
,
5405 unsigned long low_limit
,
5406 unsigned long high_limit
)
5408 unsigned long long max
= high_limit
;
5409 unsigned long log2qty
, size
;
5412 /* allow the kernel cmdline to have a say */
5414 /* round applicable memory size up to nearest megabyte */
5415 numentries
= nr_kernel_pages
;
5416 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
5417 numentries
>>= 20 - PAGE_SHIFT
;
5418 numentries
<<= 20 - PAGE_SHIFT
;
5420 /* limit to 1 bucket per 2^scale bytes of low memory */
5421 if (scale
> PAGE_SHIFT
)
5422 numentries
>>= (scale
- PAGE_SHIFT
);
5424 numentries
<<= (PAGE_SHIFT
- scale
);
5426 /* Make sure we've got at least a 0-order allocation.. */
5427 if (unlikely(flags
& HASH_SMALL
)) {
5428 /* Makes no sense without HASH_EARLY */
5429 WARN_ON(!(flags
& HASH_EARLY
));
5430 if (!(numentries
>> *_hash_shift
)) {
5431 numentries
= 1UL << *_hash_shift
;
5432 BUG_ON(!numentries
);
5434 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
5435 numentries
= PAGE_SIZE
/ bucketsize
;
5437 numentries
= roundup_pow_of_two(numentries
);
5439 /* limit allocation size to 1/16 total memory by default */
5441 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
5442 do_div(max
, bucketsize
);
5444 max
= min(max
, 0x80000000ULL
);
5446 if (numentries
< low_limit
)
5447 numentries
= low_limit
;
5448 if (numentries
> max
)
5451 log2qty
= ilog2(numentries
);
5454 size
= bucketsize
<< log2qty
;
5455 if (flags
& HASH_EARLY
)
5456 table
= alloc_bootmem_nopanic(size
);
5458 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
5461 * If bucketsize is not a power-of-two, we may free
5462 * some pages at the end of hash table which
5463 * alloc_pages_exact() automatically does
5465 if (get_order(size
) < MAX_ORDER
) {
5466 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
5467 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
5470 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
5473 panic("Failed to allocate %s hash table\n", tablename
);
5475 printk(KERN_INFO
"%s hash table entries: %ld (order: %d, %lu bytes)\n",
5478 ilog2(size
) - PAGE_SHIFT
,
5482 *_hash_shift
= log2qty
;
5484 *_hash_mask
= (1 << log2qty
) - 1;
5489 /* Return a pointer to the bitmap storing bits affecting a block of pages */
5490 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
5493 #ifdef CONFIG_SPARSEMEM
5494 return __pfn_to_section(pfn
)->pageblock_flags
;
5496 return zone
->pageblock_flags
;
5497 #endif /* CONFIG_SPARSEMEM */
5500 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
5502 #ifdef CONFIG_SPARSEMEM
5503 pfn
&= (PAGES_PER_SECTION
-1);
5504 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5506 pfn
= pfn
- zone
->zone_start_pfn
;
5507 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5508 #endif /* CONFIG_SPARSEMEM */
5512 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5513 * @page: The page within the block of interest
5514 * @start_bitidx: The first bit of interest to retrieve
5515 * @end_bitidx: The last bit of interest
5516 * returns pageblock_bits flags
5518 unsigned long get_pageblock_flags_group(struct page
*page
,
5519 int start_bitidx
, int end_bitidx
)
5522 unsigned long *bitmap
;
5523 unsigned long pfn
, bitidx
;
5524 unsigned long flags
= 0;
5525 unsigned long value
= 1;
5527 zone
= page_zone(page
);
5528 pfn
= page_to_pfn(page
);
5529 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5530 bitidx
= pfn_to_bitidx(zone
, pfn
);
5532 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5533 if (test_bit(bitidx
+ start_bitidx
, bitmap
))
5540 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5541 * @page: The page within the block of interest
5542 * @start_bitidx: The first bit of interest
5543 * @end_bitidx: The last bit of interest
5544 * @flags: The flags to set
5546 void set_pageblock_flags_group(struct page
*page
, unsigned long flags
,
5547 int start_bitidx
, int end_bitidx
)
5550 unsigned long *bitmap
;
5551 unsigned long pfn
, bitidx
;
5552 unsigned long value
= 1;
5554 zone
= page_zone(page
);
5555 pfn
= page_to_pfn(page
);
5556 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5557 bitidx
= pfn_to_bitidx(zone
, pfn
);
5558 VM_BUG_ON(pfn
< zone
->zone_start_pfn
);
5559 VM_BUG_ON(pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
);
5561 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5563 __set_bit(bitidx
+ start_bitidx
, bitmap
);
5565 __clear_bit(bitidx
+ start_bitidx
, bitmap
);
5569 * This function checks whether pageblock includes unmovable pages or not.
5570 * If @count is not zero, it is okay to include less @count unmovable pages
5572 * PageLRU check wihtout isolation or lru_lock could race so that
5573 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
5574 * expect this function should be exact.
5576 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
)
5578 unsigned long pfn
, iter
, found
;
5582 * For avoiding noise data, lru_add_drain_all() should be called
5583 * If ZONE_MOVABLE, the zone never contains unmovable pages
5585 if (zone_idx(zone
) == ZONE_MOVABLE
)
5587 mt
= get_pageblock_migratetype(page
);
5588 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
5591 pfn
= page_to_pfn(page
);
5592 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
5593 unsigned long check
= pfn
+ iter
;
5595 if (!pfn_valid_within(check
))
5598 page
= pfn_to_page(check
);
5600 * We can't use page_count without pin a page
5601 * because another CPU can free compound page.
5602 * This check already skips compound tails of THP
5603 * because their page->_count is zero at all time.
5605 if (!atomic_read(&page
->_count
)) {
5606 if (PageBuddy(page
))
5607 iter
+= (1 << page_order(page
)) - 1;
5614 * If there are RECLAIMABLE pages, we need to check it.
5615 * But now, memory offline itself doesn't call shrink_slab()
5616 * and it still to be fixed.
5619 * If the page is not RAM, page_count()should be 0.
5620 * we don't need more check. This is an _used_ not-movable page.
5622 * The problematic thing here is PG_reserved pages. PG_reserved
5623 * is set to both of a memory hole page and a _used_ kernel
5632 bool is_pageblock_removable_nolock(struct page
*page
)
5638 * We have to be careful here because we are iterating over memory
5639 * sections which are not zone aware so we might end up outside of
5640 * the zone but still within the section.
5641 * We have to take care about the node as well. If the node is offline
5642 * its NODE_DATA will be NULL - see page_zone.
5644 if (!node_online(page_to_nid(page
)))
5647 zone
= page_zone(page
);
5648 pfn
= page_to_pfn(page
);
5649 if (zone
->zone_start_pfn
> pfn
||
5650 zone
->zone_start_pfn
+ zone
->spanned_pages
<= pfn
)
5653 return !has_unmovable_pages(zone
, page
, 0);
5658 static unsigned long pfn_max_align_down(unsigned long pfn
)
5660 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
5661 pageblock_nr_pages
) - 1);
5664 static unsigned long pfn_max_align_up(unsigned long pfn
)
5666 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
5667 pageblock_nr_pages
));
5670 /* [start, end) must belong to a single zone. */
5671 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
5672 unsigned long start
, unsigned long end
)
5674 /* This function is based on compact_zone() from compaction.c. */
5676 unsigned long pfn
= start
;
5677 unsigned int tries
= 0;
5680 migrate_prep_local();
5682 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
5683 if (fatal_signal_pending(current
)) {
5688 if (list_empty(&cc
->migratepages
)) {
5689 cc
->nr_migratepages
= 0;
5690 pfn
= isolate_migratepages_range(cc
->zone
, cc
,
5697 } else if (++tries
== 5) {
5698 ret
= ret
< 0 ? ret
: -EBUSY
;
5702 reclaim_clean_pages_from_list(cc
->zone
, &cc
->migratepages
);
5704 ret
= migrate_pages(&cc
->migratepages
,
5705 alloc_migrate_target
,
5706 0, false, MIGRATE_SYNC
);
5709 putback_lru_pages(&cc
->migratepages
);
5710 return ret
> 0 ? 0 : ret
;
5714 * Update zone's cma pages counter used for watermark level calculation.
5716 static inline void __update_cma_watermarks(struct zone
*zone
, int count
)
5718 unsigned long flags
;
5719 spin_lock_irqsave(&zone
->lock
, flags
);
5720 zone
->min_cma_pages
+= count
;
5721 spin_unlock_irqrestore(&zone
->lock
, flags
);
5722 setup_per_zone_wmarks();
5726 * Trigger memory pressure bump to reclaim some pages in order to be able to
5727 * allocate 'count' pages in single page units. Does similar work as
5728 *__alloc_pages_slowpath() function.
5730 static int __reclaim_pages(struct zone
*zone
, gfp_t gfp_mask
, int count
)
5732 enum zone_type high_zoneidx
= gfp_zone(gfp_mask
);
5733 struct zonelist
*zonelist
= node_zonelist(0, gfp_mask
);
5734 int did_some_progress
= 0;
5738 * Increase level of watermarks to force kswapd do his job
5739 * to stabilise at new watermark level.
5741 __update_cma_watermarks(zone
, count
);
5743 /* Obey watermarks as if the page was being allocated */
5744 while (!zone_watermark_ok(zone
, 0, low_wmark_pages(zone
), 0, 0)) {
5745 wake_all_kswapd(order
, zonelist
, high_zoneidx
, zone_idx(zone
));
5747 did_some_progress
= __perform_reclaim(gfp_mask
, order
, zonelist
,
5749 if (!did_some_progress
) {
5750 /* Exhausted what can be done so it's blamo time */
5751 out_of_memory(zonelist
, gfp_mask
, order
, NULL
, false);
5755 /* Restore original watermark levels. */
5756 __update_cma_watermarks(zone
, -count
);
5762 * alloc_contig_range() -- tries to allocate given range of pages
5763 * @start: start PFN to allocate
5764 * @end: one-past-the-last PFN to allocate
5765 * @migratetype: migratetype of the underlaying pageblocks (either
5766 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
5767 * in range must have the same migratetype and it must
5768 * be either of the two.
5770 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
5771 * aligned, however it's the caller's responsibility to guarantee that
5772 * we are the only thread that changes migrate type of pageblocks the
5775 * The PFN range must belong to a single zone.
5777 * Returns zero on success or negative error code. On success all
5778 * pages which PFN is in [start, end) are allocated for the caller and
5779 * need to be freed with free_contig_range().
5781 int alloc_contig_range(unsigned long start
, unsigned long end
,
5782 unsigned migratetype
)
5784 struct zone
*zone
= page_zone(pfn_to_page(start
));
5785 unsigned long outer_start
, outer_end
;
5788 struct compact_control cc
= {
5789 .nr_migratepages
= 0,
5791 .zone
= page_zone(pfn_to_page(start
)),
5793 .ignore_skip_hint
= true,
5795 INIT_LIST_HEAD(&cc
.migratepages
);
5798 * What we do here is we mark all pageblocks in range as
5799 * MIGRATE_ISOLATE. Because pageblock and max order pages may
5800 * have different sizes, and due to the way page allocator
5801 * work, we align the range to biggest of the two pages so
5802 * that page allocator won't try to merge buddies from
5803 * different pageblocks and change MIGRATE_ISOLATE to some
5804 * other migration type.
5806 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
5807 * migrate the pages from an unaligned range (ie. pages that
5808 * we are interested in). This will put all the pages in
5809 * range back to page allocator as MIGRATE_ISOLATE.
5811 * When this is done, we take the pages in range from page
5812 * allocator removing them from the buddy system. This way
5813 * page allocator will never consider using them.
5815 * This lets us mark the pageblocks back as
5816 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
5817 * aligned range but not in the unaligned, original range are
5818 * put back to page allocator so that buddy can use them.
5821 ret
= start_isolate_page_range(pfn_max_align_down(start
),
5822 pfn_max_align_up(end
), migratetype
);
5826 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
5831 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
5832 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
5833 * more, all pages in [start, end) are free in page allocator.
5834 * What we are going to do is to allocate all pages from
5835 * [start, end) (that is remove them from page allocator).
5837 * The only problem is that pages at the beginning and at the
5838 * end of interesting range may be not aligned with pages that
5839 * page allocator holds, ie. they can be part of higher order
5840 * pages. Because of this, we reserve the bigger range and
5841 * once this is done free the pages we are not interested in.
5843 * We don't have to hold zone->lock here because the pages are
5844 * isolated thus they won't get removed from buddy.
5847 lru_add_drain_all();
5851 outer_start
= start
;
5852 while (!PageBuddy(pfn_to_page(outer_start
))) {
5853 if (++order
>= MAX_ORDER
) {
5857 outer_start
&= ~0UL << order
;
5860 /* Make sure the range is really isolated. */
5861 if (test_pages_isolated(outer_start
, end
)) {
5862 pr_warn("alloc_contig_range test_pages_isolated(%lx, %lx) failed\n",
5869 * Reclaim enough pages to make sure that contiguous allocation
5870 * will not starve the system.
5872 __reclaim_pages(zone
, GFP_HIGHUSER_MOVABLE
, end
-start
);
5874 /* Grab isolated pages from freelists. */
5875 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
5881 /* Free head and tail (if any) */
5882 if (start
!= outer_start
)
5883 free_contig_range(outer_start
, start
- outer_start
);
5884 if (end
!= outer_end
)
5885 free_contig_range(end
, outer_end
- end
);
5888 undo_isolate_page_range(pfn_max_align_down(start
),
5889 pfn_max_align_up(end
), migratetype
);
5893 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
5895 for (; nr_pages
--; ++pfn
)
5896 __free_page(pfn_to_page(pfn
));
5900 #ifdef CONFIG_MEMORY_HOTPLUG
5901 static int __meminit
__zone_pcp_update(void *data
)
5903 struct zone
*zone
= data
;
5905 unsigned long batch
= zone_batchsize(zone
), flags
;
5907 for_each_possible_cpu(cpu
) {
5908 struct per_cpu_pageset
*pset
;
5909 struct per_cpu_pages
*pcp
;
5911 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
5914 local_irq_save(flags
);
5916 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
5917 setup_pageset(pset
, batch
);
5918 local_irq_restore(flags
);
5923 void __meminit
zone_pcp_update(struct zone
*zone
)
5925 stop_machine(__zone_pcp_update
, zone
, NULL
);
5929 #ifdef CONFIG_MEMORY_HOTREMOVE
5930 void zone_pcp_reset(struct zone
*zone
)
5932 unsigned long flags
;
5934 /* avoid races with drain_pages() */
5935 local_irq_save(flags
);
5936 if (zone
->pageset
!= &boot_pageset
) {
5937 free_percpu(zone
->pageset
);
5938 zone
->pageset
= &boot_pageset
;
5940 local_irq_restore(flags
);
5944 * All pages in the range must be isolated before calling this.
5947 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
5953 unsigned long flags
;
5954 /* find the first valid pfn */
5955 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
5960 zone
= page_zone(pfn_to_page(pfn
));
5961 spin_lock_irqsave(&zone
->lock
, flags
);
5963 while (pfn
< end_pfn
) {
5964 if (!pfn_valid(pfn
)) {
5968 page
= pfn_to_page(pfn
);
5969 BUG_ON(page_count(page
));
5970 BUG_ON(!PageBuddy(page
));
5971 order
= page_order(page
);
5972 #ifdef CONFIG_DEBUG_VM
5973 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
5974 pfn
, 1 << order
, end_pfn
);
5976 list_del(&page
->lru
);
5977 rmv_page_order(page
);
5978 zone
->free_area
[order
].nr_free
--;
5979 __mod_zone_page_state(zone
, NR_FREE_PAGES
,
5981 for (i
= 0; i
< (1 << order
); i
++)
5982 SetPageReserved((page
+i
));
5983 pfn
+= (1 << order
);
5985 spin_unlock_irqrestore(&zone
->lock
, flags
);
5989 #ifdef CONFIG_MEMORY_FAILURE
5990 bool is_free_buddy_page(struct page
*page
)
5992 struct zone
*zone
= page_zone(page
);
5993 unsigned long pfn
= page_to_pfn(page
);
5994 unsigned long flags
;
5997 spin_lock_irqsave(&zone
->lock
, flags
);
5998 for (order
= 0; order
< MAX_ORDER
; order
++) {
5999 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
6001 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
6004 spin_unlock_irqrestore(&zone
->lock
, flags
);
6006 return order
< MAX_ORDER
;
6010 static const struct trace_print_flags pageflag_names
[] = {
6011 {1UL << PG_locked
, "locked" },
6012 {1UL << PG_error
, "error" },
6013 {1UL << PG_referenced
, "referenced" },
6014 {1UL << PG_uptodate
, "uptodate" },
6015 {1UL << PG_dirty
, "dirty" },
6016 {1UL << PG_lru
, "lru" },
6017 {1UL << PG_active
, "active" },
6018 {1UL << PG_slab
, "slab" },
6019 {1UL << PG_owner_priv_1
, "owner_priv_1" },
6020 {1UL << PG_arch_1
, "arch_1" },
6021 {1UL << PG_reserved
, "reserved" },
6022 {1UL << PG_private
, "private" },
6023 {1UL << PG_private_2
, "private_2" },
6024 {1UL << PG_writeback
, "writeback" },
6025 #ifdef CONFIG_PAGEFLAGS_EXTENDED
6026 {1UL << PG_head
, "head" },
6027 {1UL << PG_tail
, "tail" },
6029 {1UL << PG_compound
, "compound" },
6031 {1UL << PG_swapcache
, "swapcache" },
6032 {1UL << PG_mappedtodisk
, "mappedtodisk" },
6033 {1UL << PG_reclaim
, "reclaim" },
6034 {1UL << PG_swapbacked
, "swapbacked" },
6035 {1UL << PG_unevictable
, "unevictable" },
6037 {1UL << PG_mlocked
, "mlocked" },
6039 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
6040 {1UL << PG_uncached
, "uncached" },
6042 #ifdef CONFIG_MEMORY_FAILURE
6043 {1UL << PG_hwpoison
, "hwpoison" },
6045 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6046 {1UL << PG_compound_lock
, "compound_lock" },
6050 static void dump_page_flags(unsigned long flags
)
6052 const char *delim
= "";
6056 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names
) != __NR_PAGEFLAGS
);
6058 printk(KERN_ALERT
"page flags: %#lx(", flags
);
6060 /* remove zone id */
6061 flags
&= (1UL << NR_PAGEFLAGS
) - 1;
6063 for (i
= 0; i
< ARRAY_SIZE(pageflag_names
) && flags
; i
++) {
6065 mask
= pageflag_names
[i
].mask
;
6066 if ((flags
& mask
) != mask
)
6070 printk("%s%s", delim
, pageflag_names
[i
].name
);
6074 /* check for left over flags */
6076 printk("%s%#lx", delim
, flags
);
6081 void dump_page(struct page
*page
)
6084 "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
6085 page
, atomic_read(&page
->_count
), page_mapcount(page
),
6086 page
->mapping
, page
->index
);
6087 dump_page_flags(page
->flags
);
6088 mem_cgroup_print_bad_page(page
);
6091 /* reset zone->present_pages */
6092 void reset_zone_present_pages(void)
6097 for_each_node_state(nid
, N_HIGH_MEMORY
) {
6098 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6099 z
= NODE_DATA(nid
)->node_zones
+ i
;
6100 z
->present_pages
= 0;
6105 /* calculate zone's present pages in buddy system */
6106 void fixup_zone_present_pages(int nid
, unsigned long start_pfn
,
6107 unsigned long end_pfn
)
6110 unsigned long zone_start_pfn
, zone_end_pfn
;
6113 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6114 z
= NODE_DATA(nid
)->node_zones
+ i
;
6115 zone_start_pfn
= z
->zone_start_pfn
;
6116 zone_end_pfn
= zone_start_pfn
+ z
->spanned_pages
;
6118 /* if the two regions intersect */
6119 if (!(zone_start_pfn
>= end_pfn
|| zone_end_pfn
<= start_pfn
))
6120 z
->present_pages
+= min(end_pfn
, zone_end_pfn
) -
6121 max(start_pfn
, zone_start_pfn
);