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>
61 #include <linux/sched/rt.h>
63 #include <asm/tlbflush.h>
64 #include <asm/div64.h>
67 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
68 DEFINE_PER_CPU(int, numa_node
);
69 EXPORT_PER_CPU_SYMBOL(numa_node
);
72 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
74 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
75 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
76 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
77 * defined in <linux/topology.h>.
79 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
80 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
84 * Array of node states.
86 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
87 [N_POSSIBLE
] = NODE_MASK_ALL
,
88 [N_ONLINE
] = { { [0] = 1UL } },
90 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
92 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
94 #ifdef CONFIG_MOVABLE_NODE
95 [N_MEMORY
] = { { [0] = 1UL } },
97 [N_CPU
] = { { [0] = 1UL } },
100 EXPORT_SYMBOL(node_states
);
102 unsigned long totalram_pages __read_mostly
;
103 unsigned long totalreserve_pages __read_mostly
;
105 * When calculating the number of globally allowed dirty pages, there
106 * is a certain number of per-zone reserves that should not be
107 * considered dirtyable memory. This is the sum of those reserves
108 * over all existing zones that contribute dirtyable memory.
110 unsigned long dirty_balance_reserve __read_mostly
;
112 int percpu_pagelist_fraction
;
113 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
115 #ifdef CONFIG_PM_SLEEP
117 * The following functions are used by the suspend/hibernate code to temporarily
118 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
119 * while devices are suspended. To avoid races with the suspend/hibernate code,
120 * they should always be called with pm_mutex held (gfp_allowed_mask also should
121 * only be modified with pm_mutex held, unless the suspend/hibernate code is
122 * guaranteed not to run in parallel with that modification).
125 static gfp_t saved_gfp_mask
;
127 void pm_restore_gfp_mask(void)
129 WARN_ON(!mutex_is_locked(&pm_mutex
));
130 if (saved_gfp_mask
) {
131 gfp_allowed_mask
= saved_gfp_mask
;
136 void pm_restrict_gfp_mask(void)
138 WARN_ON(!mutex_is_locked(&pm_mutex
));
139 WARN_ON(saved_gfp_mask
);
140 saved_gfp_mask
= gfp_allowed_mask
;
141 gfp_allowed_mask
&= ~GFP_IOFS
;
144 bool pm_suspended_storage(void)
146 if ((gfp_allowed_mask
& GFP_IOFS
) == GFP_IOFS
)
150 #endif /* CONFIG_PM_SLEEP */
152 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
153 int pageblock_order __read_mostly
;
156 static void __free_pages_ok(struct page
*page
, unsigned int order
);
159 * results with 256, 32 in the lowmem_reserve sysctl:
160 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
161 * 1G machine -> (16M dma, 784M normal, 224M high)
162 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
163 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
164 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
166 * TBD: should special case ZONE_DMA32 machines here - in those we normally
167 * don't need any ZONE_NORMAL reservation
169 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
170 #ifdef CONFIG_ZONE_DMA
173 #ifdef CONFIG_ZONE_DMA32
176 #ifdef CONFIG_HIGHMEM
182 EXPORT_SYMBOL(totalram_pages
);
184 static char * const zone_names
[MAX_NR_ZONES
] = {
185 #ifdef CONFIG_ZONE_DMA
188 #ifdef CONFIG_ZONE_DMA32
192 #ifdef CONFIG_HIGHMEM
198 int min_free_kbytes
= 1024;
200 static unsigned long __meminitdata nr_kernel_pages
;
201 static unsigned long __meminitdata nr_all_pages
;
202 static unsigned long __meminitdata dma_reserve
;
204 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
205 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
206 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
207 static unsigned long __initdata required_kernelcore
;
208 static unsigned long __initdata required_movablecore
;
209 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
211 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
213 EXPORT_SYMBOL(movable_zone
);
214 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
217 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
218 int nr_online_nodes __read_mostly
= 1;
219 EXPORT_SYMBOL(nr_node_ids
);
220 EXPORT_SYMBOL(nr_online_nodes
);
223 int page_group_by_mobility_disabled __read_mostly
;
225 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
228 if (unlikely(page_group_by_mobility_disabled
))
229 migratetype
= MIGRATE_UNMOVABLE
;
231 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
232 PB_migrate
, PB_migrate_end
);
235 bool oom_killer_disabled __read_mostly
;
237 #ifdef CONFIG_DEBUG_VM
238 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
242 unsigned long pfn
= page_to_pfn(page
);
245 seq
= zone_span_seqbegin(zone
);
246 if (pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
248 else if (pfn
< zone
->zone_start_pfn
)
250 } while (zone_span_seqretry(zone
, seq
));
255 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
257 if (!pfn_valid_within(page_to_pfn(page
)))
259 if (zone
!= page_zone(page
))
265 * Temporary debugging check for pages not lying within a given zone.
267 static int bad_range(struct zone
*zone
, struct page
*page
)
269 if (page_outside_zone_boundaries(zone
, page
))
271 if (!page_is_consistent(zone
, page
))
277 static inline int bad_range(struct zone
*zone
, struct page
*page
)
283 static void bad_page(struct page
*page
)
285 static unsigned long resume
;
286 static unsigned long nr_shown
;
287 static unsigned long nr_unshown
;
289 /* Don't complain about poisoned pages */
290 if (PageHWPoison(page
)) {
291 reset_page_mapcount(page
); /* remove PageBuddy */
296 * Allow a burst of 60 reports, then keep quiet for that minute;
297 * or allow a steady drip of one report per second.
299 if (nr_shown
== 60) {
300 if (time_before(jiffies
, resume
)) {
306 "BUG: Bad page state: %lu messages suppressed\n",
313 resume
= jiffies
+ 60 * HZ
;
315 printk(KERN_ALERT
"BUG: Bad page state in process %s pfn:%05lx\n",
316 current
->comm
, page_to_pfn(page
));
322 /* Leave bad fields for debug, except PageBuddy could make trouble */
323 reset_page_mapcount(page
); /* remove PageBuddy */
324 add_taint(TAINT_BAD_PAGE
);
328 * Higher-order pages are called "compound pages". They are structured thusly:
330 * The first PAGE_SIZE page is called the "head page".
332 * The remaining PAGE_SIZE pages are called "tail pages".
334 * All pages have PG_compound set. All tail pages have their ->first_page
335 * pointing at the head page.
337 * The first tail page's ->lru.next holds the address of the compound page's
338 * put_page() function. Its ->lru.prev holds the order of allocation.
339 * This usage means that zero-order pages may not be compound.
342 static void free_compound_page(struct page
*page
)
344 __free_pages_ok(page
, compound_order(page
));
347 void prep_compound_page(struct page
*page
, unsigned long order
)
350 int nr_pages
= 1 << order
;
352 set_compound_page_dtor(page
, free_compound_page
);
353 set_compound_order(page
, order
);
355 for (i
= 1; i
< nr_pages
; i
++) {
356 struct page
*p
= page
+ i
;
358 set_page_count(p
, 0);
359 p
->first_page
= page
;
363 /* update __split_huge_page_refcount if you change this function */
364 static int destroy_compound_page(struct page
*page
, unsigned long order
)
367 int nr_pages
= 1 << order
;
370 if (unlikely(compound_order(page
) != order
)) {
375 __ClearPageHead(page
);
377 for (i
= 1; i
< nr_pages
; i
++) {
378 struct page
*p
= page
+ i
;
380 if (unlikely(!PageTail(p
) || (p
->first_page
!= page
))) {
390 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
395 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
396 * and __GFP_HIGHMEM from hard or soft interrupt context.
398 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
399 for (i
= 0; i
< (1 << order
); i
++)
400 clear_highpage(page
+ i
);
403 #ifdef CONFIG_DEBUG_PAGEALLOC
404 unsigned int _debug_guardpage_minorder
;
406 static int __init
debug_guardpage_minorder_setup(char *buf
)
410 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
411 printk(KERN_ERR
"Bad debug_guardpage_minorder value\n");
414 _debug_guardpage_minorder
= res
;
415 printk(KERN_INFO
"Setting debug_guardpage_minorder to %lu\n", res
);
418 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
420 static inline void set_page_guard_flag(struct page
*page
)
422 __set_bit(PAGE_DEBUG_FLAG_GUARD
, &page
->debug_flags
);
425 static inline void clear_page_guard_flag(struct page
*page
)
427 __clear_bit(PAGE_DEBUG_FLAG_GUARD
, &page
->debug_flags
);
430 static inline void set_page_guard_flag(struct page
*page
) { }
431 static inline void clear_page_guard_flag(struct page
*page
) { }
434 static inline void set_page_order(struct page
*page
, int order
)
436 set_page_private(page
, order
);
437 __SetPageBuddy(page
);
440 static inline void rmv_page_order(struct page
*page
)
442 __ClearPageBuddy(page
);
443 set_page_private(page
, 0);
447 * Locate the struct page for both the matching buddy in our
448 * pair (buddy1) and the combined O(n+1) page they form (page).
450 * 1) Any buddy B1 will have an order O twin B2 which satisfies
451 * the following equation:
453 * For example, if the starting buddy (buddy2) is #8 its order
455 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
457 * 2) Any buddy B will have an order O+1 parent P which
458 * satisfies the following equation:
461 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
463 static inline unsigned long
464 __find_buddy_index(unsigned long page_idx
, unsigned int order
)
466 return page_idx
^ (1 << order
);
470 * This function checks whether a page is free && is the buddy
471 * we can do coalesce a page and its buddy if
472 * (a) the buddy is not in a hole &&
473 * (b) the buddy is in the buddy system &&
474 * (c) a page and its buddy have the same order &&
475 * (d) a page and its buddy are in the same zone.
477 * For recording whether a page is in the buddy system, we set ->_mapcount -2.
478 * Setting, clearing, and testing _mapcount -2 is serialized by zone->lock.
480 * For recording page's order, we use page_private(page).
482 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
485 if (!pfn_valid_within(page_to_pfn(buddy
)))
488 if (page_zone_id(page
) != page_zone_id(buddy
))
491 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
492 VM_BUG_ON(page_count(buddy
) != 0);
496 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
497 VM_BUG_ON(page_count(buddy
) != 0);
504 * Freeing function for a buddy system allocator.
506 * The concept of a buddy system is to maintain direct-mapped table
507 * (containing bit values) for memory blocks of various "orders".
508 * The bottom level table contains the map for the smallest allocatable
509 * units of memory (here, pages), and each level above it describes
510 * pairs of units from the levels below, hence, "buddies".
511 * At a high level, all that happens here is marking the table entry
512 * at the bottom level available, and propagating the changes upward
513 * as necessary, plus some accounting needed to play nicely with other
514 * parts of the VM system.
515 * At each level, we keep a list of pages, which are heads of continuous
516 * free pages of length of (1 << order) and marked with _mapcount -2. Page's
517 * order is recorded in page_private(page) field.
518 * So when we are allocating or freeing one, we can derive the state of the
519 * other. That is, if we allocate a small block, and both were
520 * free, the remainder of the region must be split into blocks.
521 * If a block is freed, and its buddy is also free, then this
522 * triggers coalescing into a block of larger size.
527 static inline void __free_one_page(struct page
*page
,
528 struct zone
*zone
, unsigned int order
,
531 unsigned long page_idx
;
532 unsigned long combined_idx
;
533 unsigned long uninitialized_var(buddy_idx
);
536 if (unlikely(PageCompound(page
)))
537 if (unlikely(destroy_compound_page(page
, order
)))
540 VM_BUG_ON(migratetype
== -1);
542 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
544 VM_BUG_ON(page_idx
& ((1 << order
) - 1));
545 VM_BUG_ON(bad_range(zone
, page
));
547 while (order
< MAX_ORDER
-1) {
548 buddy_idx
= __find_buddy_index(page_idx
, order
);
549 buddy
= page
+ (buddy_idx
- page_idx
);
550 if (!page_is_buddy(page
, buddy
, order
))
553 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
554 * merge with it and move up one order.
556 if (page_is_guard(buddy
)) {
557 clear_page_guard_flag(buddy
);
558 set_page_private(page
, 0);
559 __mod_zone_freepage_state(zone
, 1 << order
,
562 list_del(&buddy
->lru
);
563 zone
->free_area
[order
].nr_free
--;
564 rmv_page_order(buddy
);
566 combined_idx
= buddy_idx
& page_idx
;
567 page
= page
+ (combined_idx
- page_idx
);
568 page_idx
= combined_idx
;
571 set_page_order(page
, order
);
574 * If this is not the largest possible page, check if the buddy
575 * of the next-highest order is free. If it is, it's possible
576 * that pages are being freed that will coalesce soon. In case,
577 * that is happening, add the free page to the tail of the list
578 * so it's less likely to be used soon and more likely to be merged
579 * as a higher order page
581 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
582 struct page
*higher_page
, *higher_buddy
;
583 combined_idx
= buddy_idx
& page_idx
;
584 higher_page
= page
+ (combined_idx
- page_idx
);
585 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
586 higher_buddy
= higher_page
+ (buddy_idx
- combined_idx
);
587 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
588 list_add_tail(&page
->lru
,
589 &zone
->free_area
[order
].free_list
[migratetype
]);
594 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
596 zone
->free_area
[order
].nr_free
++;
599 static inline int free_pages_check(struct page
*page
)
601 if (unlikely(page_mapcount(page
) |
602 (page
->mapping
!= NULL
) |
603 (atomic_read(&page
->_count
) != 0) |
604 (page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
) |
605 (mem_cgroup_bad_page_check(page
)))) {
609 reset_page_last_nid(page
);
610 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
611 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
616 * Frees a number of pages from the PCP lists
617 * Assumes all pages on list are in same zone, and of same order.
618 * count is the number of pages to free.
620 * If the zone was previously in an "all pages pinned" state then look to
621 * see if this freeing clears that state.
623 * And clear the zone's pages_scanned counter, to hold off the "all pages are
624 * pinned" detection logic.
626 static void free_pcppages_bulk(struct zone
*zone
, int count
,
627 struct per_cpu_pages
*pcp
)
633 spin_lock(&zone
->lock
);
634 zone
->all_unreclaimable
= 0;
635 zone
->pages_scanned
= 0;
639 struct list_head
*list
;
642 * Remove pages from lists in a round-robin fashion. A
643 * batch_free count is maintained that is incremented when an
644 * empty list is encountered. This is so more pages are freed
645 * off fuller lists instead of spinning excessively around empty
650 if (++migratetype
== MIGRATE_PCPTYPES
)
652 list
= &pcp
->lists
[migratetype
];
653 } while (list_empty(list
));
655 /* This is the only non-empty list. Free them all. */
656 if (batch_free
== MIGRATE_PCPTYPES
)
657 batch_free
= to_free
;
660 int mt
; /* migratetype of the to-be-freed page */
662 page
= list_entry(list
->prev
, struct page
, lru
);
663 /* must delete as __free_one_page list manipulates */
664 list_del(&page
->lru
);
665 mt
= get_freepage_migratetype(page
);
666 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
667 __free_one_page(page
, zone
, 0, mt
);
668 trace_mm_page_pcpu_drain(page
, 0, mt
);
669 if (likely(get_pageblock_migratetype(page
) != MIGRATE_ISOLATE
)) {
670 __mod_zone_page_state(zone
, NR_FREE_PAGES
, 1);
671 if (is_migrate_cma(mt
))
672 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
, 1);
674 } while (--to_free
&& --batch_free
&& !list_empty(list
));
676 spin_unlock(&zone
->lock
);
679 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
,
682 spin_lock(&zone
->lock
);
683 zone
->all_unreclaimable
= 0;
684 zone
->pages_scanned
= 0;
686 __free_one_page(page
, zone
, order
, migratetype
);
687 if (unlikely(migratetype
!= MIGRATE_ISOLATE
))
688 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
689 spin_unlock(&zone
->lock
);
692 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
697 trace_mm_page_free(page
, order
);
698 kmemcheck_free_shadow(page
, order
);
701 page
->mapping
= NULL
;
702 for (i
= 0; i
< (1 << order
); i
++)
703 bad
+= free_pages_check(page
+ i
);
707 if (!PageHighMem(page
)) {
708 debug_check_no_locks_freed(page_address(page
),PAGE_SIZE
<<order
);
709 debug_check_no_obj_freed(page_address(page
),
712 arch_free_page(page
, order
);
713 kernel_map_pages(page
, 1 << order
, 0);
718 static void __free_pages_ok(struct page
*page
, unsigned int order
)
723 if (!free_pages_prepare(page
, order
))
726 local_irq_save(flags
);
727 __count_vm_events(PGFREE
, 1 << order
);
728 migratetype
= get_pageblock_migratetype(page
);
729 set_freepage_migratetype(page
, migratetype
);
730 free_one_page(page_zone(page
), page
, order
, migratetype
);
731 local_irq_restore(flags
);
735 * Read access to zone->managed_pages is safe because it's unsigned long,
736 * but we still need to serialize writers. Currently all callers of
737 * __free_pages_bootmem() except put_page_bootmem() should only be used
738 * at boot time. So for shorter boot time, we shift the burden to
739 * put_page_bootmem() to serialize writers.
741 void __meminit
__free_pages_bootmem(struct page
*page
, unsigned int order
)
743 unsigned int nr_pages
= 1 << order
;
747 for (loop
= 0; loop
< nr_pages
; loop
++) {
748 struct page
*p
= &page
[loop
];
750 if (loop
+ 1 < nr_pages
)
752 __ClearPageReserved(p
);
753 set_page_count(p
, 0);
756 page_zone(page
)->managed_pages
+= 1 << order
;
757 set_page_refcounted(page
);
758 __free_pages(page
, order
);
762 /* Free whole pageblock and set it's migration type to MIGRATE_CMA. */
763 void __init
init_cma_reserved_pageblock(struct page
*page
)
765 unsigned i
= pageblock_nr_pages
;
766 struct page
*p
= page
;
769 __ClearPageReserved(p
);
770 set_page_count(p
, 0);
773 set_page_refcounted(page
);
774 set_pageblock_migratetype(page
, MIGRATE_CMA
);
775 __free_pages(page
, pageblock_order
);
776 totalram_pages
+= pageblock_nr_pages
;
777 #ifdef CONFIG_HIGHMEM
778 if (PageHighMem(page
))
779 totalhigh_pages
+= pageblock_nr_pages
;
785 * The order of subdivision here is critical for the IO subsystem.
786 * Please do not alter this order without good reasons and regression
787 * testing. Specifically, as large blocks of memory are subdivided,
788 * the order in which smaller blocks are delivered depends on the order
789 * they're subdivided in this function. This is the primary factor
790 * influencing the order in which pages are delivered to the IO
791 * subsystem according to empirical testing, and this is also justified
792 * by considering the behavior of a buddy system containing a single
793 * large block of memory acted on by a series of small allocations.
794 * This behavior is a critical factor in sglist merging's success.
798 static inline void expand(struct zone
*zone
, struct page
*page
,
799 int low
, int high
, struct free_area
*area
,
802 unsigned long size
= 1 << high
;
808 VM_BUG_ON(bad_range(zone
, &page
[size
]));
810 #ifdef CONFIG_DEBUG_PAGEALLOC
811 if (high
< debug_guardpage_minorder()) {
813 * Mark as guard pages (or page), that will allow to
814 * merge back to allocator when buddy will be freed.
815 * Corresponding page table entries will not be touched,
816 * pages will stay not present in virtual address space
818 INIT_LIST_HEAD(&page
[size
].lru
);
819 set_page_guard_flag(&page
[size
]);
820 set_page_private(&page
[size
], high
);
821 /* Guard pages are not available for any usage */
822 __mod_zone_freepage_state(zone
, -(1 << high
),
827 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
829 set_page_order(&page
[size
], high
);
834 * This page is about to be returned from the page allocator
836 static inline int check_new_page(struct page
*page
)
838 if (unlikely(page_mapcount(page
) |
839 (page
->mapping
!= NULL
) |
840 (atomic_read(&page
->_count
) != 0) |
841 (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
) |
842 (mem_cgroup_bad_page_check(page
)))) {
849 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
853 for (i
= 0; i
< (1 << order
); i
++) {
854 struct page
*p
= page
+ i
;
855 if (unlikely(check_new_page(p
)))
859 set_page_private(page
, 0);
860 set_page_refcounted(page
);
862 arch_alloc_page(page
, order
);
863 kernel_map_pages(page
, 1 << order
, 1);
865 if (gfp_flags
& __GFP_ZERO
)
866 prep_zero_page(page
, order
, gfp_flags
);
868 if (order
&& (gfp_flags
& __GFP_COMP
))
869 prep_compound_page(page
, order
);
875 * Go through the free lists for the given migratetype and remove
876 * the smallest available page from the freelists
879 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
882 unsigned int current_order
;
883 struct free_area
* area
;
886 /* Find a page of the appropriate size in the preferred list */
887 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
888 area
= &(zone
->free_area
[current_order
]);
889 if (list_empty(&area
->free_list
[migratetype
]))
892 page
= list_entry(area
->free_list
[migratetype
].next
,
894 list_del(&page
->lru
);
895 rmv_page_order(page
);
897 expand(zone
, page
, order
, current_order
, area
, migratetype
);
906 * This array describes the order lists are fallen back to when
907 * the free lists for the desirable migrate type are depleted
909 static int fallbacks
[MIGRATE_TYPES
][4] = {
910 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
911 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
913 [MIGRATE_MOVABLE
] = { MIGRATE_CMA
, MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
914 [MIGRATE_CMA
] = { MIGRATE_RESERVE
}, /* Never used */
916 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
918 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
}, /* Never used */
919 [MIGRATE_ISOLATE
] = { MIGRATE_RESERVE
}, /* Never used */
923 * Move the free pages in a range to the free lists of the requested type.
924 * Note that start_page and end_pages are not aligned on a pageblock
925 * boundary. If alignment is required, use move_freepages_block()
927 int move_freepages(struct zone
*zone
,
928 struct page
*start_page
, struct page
*end_page
,
935 #ifndef CONFIG_HOLES_IN_ZONE
937 * page_zone is not safe to call in this context when
938 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
939 * anyway as we check zone boundaries in move_freepages_block().
940 * Remove at a later date when no bug reports exist related to
941 * grouping pages by mobility
943 BUG_ON(page_zone(start_page
) != page_zone(end_page
));
946 for (page
= start_page
; page
<= end_page
;) {
947 /* Make sure we are not inadvertently changing nodes */
948 VM_BUG_ON(page_to_nid(page
) != zone_to_nid(zone
));
950 if (!pfn_valid_within(page_to_pfn(page
))) {
955 if (!PageBuddy(page
)) {
960 order
= page_order(page
);
961 list_move(&page
->lru
,
962 &zone
->free_area
[order
].free_list
[migratetype
]);
963 set_freepage_migratetype(page
, migratetype
);
965 pages_moved
+= 1 << order
;
971 int move_freepages_block(struct zone
*zone
, struct page
*page
,
974 unsigned long start_pfn
, end_pfn
;
975 struct page
*start_page
, *end_page
;
977 start_pfn
= page_to_pfn(page
);
978 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
979 start_page
= pfn_to_page(start_pfn
);
980 end_page
= start_page
+ pageblock_nr_pages
- 1;
981 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
983 /* Do not cross zone boundaries */
984 if (start_pfn
< zone
->zone_start_pfn
)
986 if (end_pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
989 return move_freepages(zone
, start_page
, end_page
, migratetype
);
992 static void change_pageblock_range(struct page
*pageblock_page
,
993 int start_order
, int migratetype
)
995 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
997 while (nr_pageblocks
--) {
998 set_pageblock_migratetype(pageblock_page
, migratetype
);
999 pageblock_page
+= pageblock_nr_pages
;
1003 /* Remove an element from the buddy allocator from the fallback list */
1004 static inline struct page
*
1005 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
)
1007 struct free_area
* area
;
1012 /* Find the largest possible block of pages in the other list */
1013 for (current_order
= MAX_ORDER
-1; current_order
>= order
;
1016 migratetype
= fallbacks
[start_migratetype
][i
];
1018 /* MIGRATE_RESERVE handled later if necessary */
1019 if (migratetype
== MIGRATE_RESERVE
)
1022 area
= &(zone
->free_area
[current_order
]);
1023 if (list_empty(&area
->free_list
[migratetype
]))
1026 page
= list_entry(area
->free_list
[migratetype
].next
,
1031 * If breaking a large block of pages, move all free
1032 * pages to the preferred allocation list. If falling
1033 * back for a reclaimable kernel allocation, be more
1034 * aggressive about taking ownership of free pages
1036 * On the other hand, never change migration
1037 * type of MIGRATE_CMA pageblocks nor move CMA
1038 * pages on different free lists. We don't
1039 * want unmovable pages to be allocated from
1040 * MIGRATE_CMA areas.
1042 if (!is_migrate_cma(migratetype
) &&
1043 (unlikely(current_order
>= pageblock_order
/ 2) ||
1044 start_migratetype
== MIGRATE_RECLAIMABLE
||
1045 page_group_by_mobility_disabled
)) {
1047 pages
= move_freepages_block(zone
, page
,
1050 /* Claim the whole block if over half of it is free */
1051 if (pages
>= (1 << (pageblock_order
-1)) ||
1052 page_group_by_mobility_disabled
)
1053 set_pageblock_migratetype(page
,
1056 migratetype
= start_migratetype
;
1059 /* Remove the page from the freelists */
1060 list_del(&page
->lru
);
1061 rmv_page_order(page
);
1063 /* Take ownership for orders >= pageblock_order */
1064 if (current_order
>= pageblock_order
&&
1065 !is_migrate_cma(migratetype
))
1066 change_pageblock_range(page
, current_order
,
1069 expand(zone
, page
, order
, current_order
, area
,
1070 is_migrate_cma(migratetype
)
1071 ? migratetype
: start_migratetype
);
1073 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
1074 start_migratetype
, migratetype
);
1084 * Do the hard work of removing an element from the buddy allocator.
1085 * Call me with the zone->lock already held.
1087 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
1093 page
= __rmqueue_smallest(zone
, order
, migratetype
);
1095 if (unlikely(!page
) && migratetype
!= MIGRATE_RESERVE
) {
1096 page
= __rmqueue_fallback(zone
, order
, migratetype
);
1099 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1100 * is used because __rmqueue_smallest is an inline function
1101 * and we want just one call site
1104 migratetype
= MIGRATE_RESERVE
;
1109 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1114 * Obtain a specified number of elements from the buddy allocator, all under
1115 * a single hold of the lock, for efficiency. Add them to the supplied list.
1116 * Returns the number of new pages which were placed at *list.
1118 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1119 unsigned long count
, struct list_head
*list
,
1120 int migratetype
, int cold
)
1122 int mt
= migratetype
, i
;
1124 spin_lock(&zone
->lock
);
1125 for (i
= 0; i
< count
; ++i
) {
1126 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
1127 if (unlikely(page
== NULL
))
1131 * Split buddy pages returned by expand() are received here
1132 * in physical page order. The page is added to the callers and
1133 * list and the list head then moves forward. From the callers
1134 * perspective, the linked list is ordered by page number in
1135 * some conditions. This is useful for IO devices that can
1136 * merge IO requests if the physical pages are ordered
1139 if (likely(cold
== 0))
1140 list_add(&page
->lru
, list
);
1142 list_add_tail(&page
->lru
, list
);
1143 if (IS_ENABLED(CONFIG_CMA
)) {
1144 mt
= get_pageblock_migratetype(page
);
1145 if (!is_migrate_cma(mt
) && mt
!= MIGRATE_ISOLATE
)
1148 set_freepage_migratetype(page
, mt
);
1150 if (is_migrate_cma(mt
))
1151 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
1154 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
1155 spin_unlock(&zone
->lock
);
1161 * Called from the vmstat counter updater to drain pagesets of this
1162 * currently executing processor on remote nodes after they have
1165 * Note that this function must be called with the thread pinned to
1166 * a single processor.
1168 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
1170 unsigned long flags
;
1173 local_irq_save(flags
);
1174 if (pcp
->count
>= pcp
->batch
)
1175 to_drain
= pcp
->batch
;
1177 to_drain
= pcp
->count
;
1179 free_pcppages_bulk(zone
, to_drain
, pcp
);
1180 pcp
->count
-= to_drain
;
1182 local_irq_restore(flags
);
1187 * Drain pages of the indicated processor.
1189 * The processor must either be the current processor and the
1190 * thread pinned to the current processor or a processor that
1193 static void drain_pages(unsigned int cpu
)
1195 unsigned long flags
;
1198 for_each_populated_zone(zone
) {
1199 struct per_cpu_pageset
*pset
;
1200 struct per_cpu_pages
*pcp
;
1202 local_irq_save(flags
);
1203 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
1207 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1210 local_irq_restore(flags
);
1215 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1217 void drain_local_pages(void *arg
)
1219 drain_pages(smp_processor_id());
1223 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1225 * Note that this code is protected against sending an IPI to an offline
1226 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1227 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1228 * nothing keeps CPUs from showing up after we populated the cpumask and
1229 * before the call to on_each_cpu_mask().
1231 void drain_all_pages(void)
1234 struct per_cpu_pageset
*pcp
;
1238 * Allocate in the BSS so we wont require allocation in
1239 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1241 static cpumask_t cpus_with_pcps
;
1244 * We don't care about racing with CPU hotplug event
1245 * as offline notification will cause the notified
1246 * cpu to drain that CPU pcps and on_each_cpu_mask
1247 * disables preemption as part of its processing
1249 for_each_online_cpu(cpu
) {
1250 bool has_pcps
= false;
1251 for_each_populated_zone(zone
) {
1252 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
1253 if (pcp
->pcp
.count
) {
1259 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
1261 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
1263 on_each_cpu_mask(&cpus_with_pcps
, drain_local_pages
, NULL
, 1);
1266 #ifdef CONFIG_HIBERNATION
1268 void mark_free_pages(struct zone
*zone
)
1270 unsigned long pfn
, max_zone_pfn
;
1271 unsigned long flags
;
1273 struct list_head
*curr
;
1275 if (!zone
->spanned_pages
)
1278 spin_lock_irqsave(&zone
->lock
, flags
);
1280 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
1281 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1282 if (pfn_valid(pfn
)) {
1283 struct page
*page
= pfn_to_page(pfn
);
1285 if (!swsusp_page_is_forbidden(page
))
1286 swsusp_unset_page_free(page
);
1289 for_each_migratetype_order(order
, t
) {
1290 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
1293 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
1294 for (i
= 0; i
< (1UL << order
); i
++)
1295 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
1298 spin_unlock_irqrestore(&zone
->lock
, flags
);
1300 #endif /* CONFIG_PM */
1303 * Free a 0-order page
1304 * cold == 1 ? free a cold page : free a hot page
1306 void free_hot_cold_page(struct page
*page
, int cold
)
1308 struct zone
*zone
= page_zone(page
);
1309 struct per_cpu_pages
*pcp
;
1310 unsigned long flags
;
1313 if (!free_pages_prepare(page
, 0))
1316 migratetype
= get_pageblock_migratetype(page
);
1317 set_freepage_migratetype(page
, migratetype
);
1318 local_irq_save(flags
);
1319 __count_vm_event(PGFREE
);
1322 * We only track unmovable, reclaimable and movable on pcp lists.
1323 * Free ISOLATE pages back to the allocator because they are being
1324 * offlined but treat RESERVE as movable pages so we can get those
1325 * areas back if necessary. Otherwise, we may have to free
1326 * excessively into the page allocator
1328 if (migratetype
>= MIGRATE_PCPTYPES
) {
1329 if (unlikely(migratetype
== MIGRATE_ISOLATE
)) {
1330 free_one_page(zone
, page
, 0, migratetype
);
1333 migratetype
= MIGRATE_MOVABLE
;
1336 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1338 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
1340 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
1342 if (pcp
->count
>= pcp
->high
) {
1343 free_pcppages_bulk(zone
, pcp
->batch
, pcp
);
1344 pcp
->count
-= pcp
->batch
;
1348 local_irq_restore(flags
);
1352 * Free a list of 0-order pages
1354 void free_hot_cold_page_list(struct list_head
*list
, int cold
)
1356 struct page
*page
, *next
;
1358 list_for_each_entry_safe(page
, next
, list
, lru
) {
1359 trace_mm_page_free_batched(page
, cold
);
1360 free_hot_cold_page(page
, cold
);
1365 * split_page takes a non-compound higher-order page, and splits it into
1366 * n (1<<order) sub-pages: page[0..n]
1367 * Each sub-page must be freed individually.
1369 * Note: this is probably too low level an operation for use in drivers.
1370 * Please consult with lkml before using this in your driver.
1372 void split_page(struct page
*page
, unsigned int order
)
1376 VM_BUG_ON(PageCompound(page
));
1377 VM_BUG_ON(!page_count(page
));
1379 #ifdef CONFIG_KMEMCHECK
1381 * Split shadow pages too, because free(page[0]) would
1382 * otherwise free the whole shadow.
1384 if (kmemcheck_page_is_tracked(page
))
1385 split_page(virt_to_page(page
[0].shadow
), order
);
1388 for (i
= 1; i
< (1 << order
); i
++)
1389 set_page_refcounted(page
+ i
);
1392 static int __isolate_free_page(struct page
*page
, unsigned int order
)
1394 unsigned long watermark
;
1398 BUG_ON(!PageBuddy(page
));
1400 zone
= page_zone(page
);
1401 mt
= get_pageblock_migratetype(page
);
1403 if (mt
!= MIGRATE_ISOLATE
) {
1404 /* Obey watermarks as if the page was being allocated */
1405 watermark
= low_wmark_pages(zone
) + (1 << order
);
1406 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
1409 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
1412 /* Remove page from free list */
1413 list_del(&page
->lru
);
1414 zone
->free_area
[order
].nr_free
--;
1415 rmv_page_order(page
);
1417 /* Set the pageblock if the isolated page is at least a pageblock */
1418 if (order
>= pageblock_order
- 1) {
1419 struct page
*endpage
= page
+ (1 << order
) - 1;
1420 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
1421 int mt
= get_pageblock_migratetype(page
);
1422 if (mt
!= MIGRATE_ISOLATE
&& !is_migrate_cma(mt
))
1423 set_pageblock_migratetype(page
,
1428 return 1UL << order
;
1432 * Similar to split_page except the page is already free. As this is only
1433 * being used for migration, the migratetype of the block also changes.
1434 * As this is called with interrupts disabled, the caller is responsible
1435 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1438 * Note: this is probably too low level an operation for use in drivers.
1439 * Please consult with lkml before using this in your driver.
1441 int split_free_page(struct page
*page
)
1446 order
= page_order(page
);
1448 nr_pages
= __isolate_free_page(page
, order
);
1452 /* Split into individual pages */
1453 set_page_refcounted(page
);
1454 split_page(page
, order
);
1459 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1460 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1464 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
1465 struct zone
*zone
, int order
, gfp_t gfp_flags
,
1468 unsigned long flags
;
1470 int cold
= !!(gfp_flags
& __GFP_COLD
);
1473 if (likely(order
== 0)) {
1474 struct per_cpu_pages
*pcp
;
1475 struct list_head
*list
;
1477 local_irq_save(flags
);
1478 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1479 list
= &pcp
->lists
[migratetype
];
1480 if (list_empty(list
)) {
1481 pcp
->count
+= rmqueue_bulk(zone
, 0,
1484 if (unlikely(list_empty(list
)))
1489 page
= list_entry(list
->prev
, struct page
, lru
);
1491 page
= list_entry(list
->next
, struct page
, lru
);
1493 list_del(&page
->lru
);
1496 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
1498 * __GFP_NOFAIL is not to be used in new code.
1500 * All __GFP_NOFAIL callers should be fixed so that they
1501 * properly detect and handle allocation failures.
1503 * We most definitely don't want callers attempting to
1504 * allocate greater than order-1 page units with
1507 WARN_ON_ONCE(order
> 1);
1509 spin_lock_irqsave(&zone
->lock
, flags
);
1510 page
= __rmqueue(zone
, order
, migratetype
);
1511 spin_unlock(&zone
->lock
);
1514 __mod_zone_freepage_state(zone
, -(1 << order
),
1515 get_pageblock_migratetype(page
));
1518 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
1519 zone_statistics(preferred_zone
, zone
, gfp_flags
);
1520 local_irq_restore(flags
);
1522 VM_BUG_ON(bad_range(zone
, page
));
1523 if (prep_new_page(page
, order
, gfp_flags
))
1528 local_irq_restore(flags
);
1532 #ifdef CONFIG_FAIL_PAGE_ALLOC
1535 struct fault_attr attr
;
1537 u32 ignore_gfp_highmem
;
1538 u32 ignore_gfp_wait
;
1540 } fail_page_alloc
= {
1541 .attr
= FAULT_ATTR_INITIALIZER
,
1542 .ignore_gfp_wait
= 1,
1543 .ignore_gfp_highmem
= 1,
1547 static int __init
setup_fail_page_alloc(char *str
)
1549 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
1551 __setup("fail_page_alloc=", setup_fail_page_alloc
);
1553 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1555 if (order
< fail_page_alloc
.min_order
)
1557 if (gfp_mask
& __GFP_NOFAIL
)
1559 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
1561 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
1564 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
1567 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1569 static int __init
fail_page_alloc_debugfs(void)
1571 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
1574 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
1575 &fail_page_alloc
.attr
);
1577 return PTR_ERR(dir
);
1579 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
1580 &fail_page_alloc
.ignore_gfp_wait
))
1582 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
1583 &fail_page_alloc
.ignore_gfp_highmem
))
1585 if (!debugfs_create_u32("min-order", mode
, dir
,
1586 &fail_page_alloc
.min_order
))
1591 debugfs_remove_recursive(dir
);
1596 late_initcall(fail_page_alloc_debugfs
);
1598 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1600 #else /* CONFIG_FAIL_PAGE_ALLOC */
1602 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1607 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1610 * Return true if free pages are above 'mark'. This takes into account the order
1611 * of the allocation.
1613 static bool __zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1614 int classzone_idx
, int alloc_flags
, long free_pages
)
1616 /* free_pages my go negative - that's OK */
1618 long lowmem_reserve
= z
->lowmem_reserve
[classzone_idx
];
1621 free_pages
-= (1 << order
) - 1;
1622 if (alloc_flags
& ALLOC_HIGH
)
1624 if (alloc_flags
& ALLOC_HARDER
)
1627 /* If allocation can't use CMA areas don't use free CMA pages */
1628 if (!(alloc_flags
& ALLOC_CMA
))
1629 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
1631 if (free_pages
<= min
+ lowmem_reserve
)
1633 for (o
= 0; o
< order
; o
++) {
1634 /* At the next order, this order's pages become unavailable */
1635 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1637 /* Require fewer higher order pages to be free */
1640 if (free_pages
<= min
)
1646 bool zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1647 int classzone_idx
, int alloc_flags
)
1649 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1650 zone_page_state(z
, NR_FREE_PAGES
));
1653 bool zone_watermark_ok_safe(struct zone
*z
, int order
, unsigned long mark
,
1654 int classzone_idx
, int alloc_flags
)
1656 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
1658 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
1659 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
1661 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1667 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1668 * skip over zones that are not allowed by the cpuset, or that have
1669 * been recently (in last second) found to be nearly full. See further
1670 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1671 * that have to skip over a lot of full or unallowed zones.
1673 * If the zonelist cache is present in the passed in zonelist, then
1674 * returns a pointer to the allowed node mask (either the current
1675 * tasks mems_allowed, or node_states[N_MEMORY].)
1677 * If the zonelist cache is not available for this zonelist, does
1678 * nothing and returns NULL.
1680 * If the fullzones BITMAP in the zonelist cache is stale (more than
1681 * a second since last zap'd) then we zap it out (clear its bits.)
1683 * We hold off even calling zlc_setup, until after we've checked the
1684 * first zone in the zonelist, on the theory that most allocations will
1685 * be satisfied from that first zone, so best to examine that zone as
1686 * quickly as we can.
1688 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1690 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1691 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1693 zlc
= zonelist
->zlcache_ptr
;
1697 if (time_after(jiffies
, zlc
->last_full_zap
+ HZ
)) {
1698 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1699 zlc
->last_full_zap
= jiffies
;
1702 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1703 &cpuset_current_mems_allowed
:
1704 &node_states
[N_MEMORY
];
1705 return allowednodes
;
1709 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1710 * if it is worth looking at further for free memory:
1711 * 1) Check that the zone isn't thought to be full (doesn't have its
1712 * bit set in the zonelist_cache fullzones BITMAP).
1713 * 2) Check that the zones node (obtained from the zonelist_cache
1714 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1715 * Return true (non-zero) if zone is worth looking at further, or
1716 * else return false (zero) if it is not.
1718 * This check -ignores- the distinction between various watermarks,
1719 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1720 * found to be full for any variation of these watermarks, it will
1721 * be considered full for up to one second by all requests, unless
1722 * we are so low on memory on all allowed nodes that we are forced
1723 * into the second scan of the zonelist.
1725 * In the second scan we ignore this zonelist cache and exactly
1726 * apply the watermarks to all zones, even it is slower to do so.
1727 * We are low on memory in the second scan, and should leave no stone
1728 * unturned looking for a free page.
1730 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1731 nodemask_t
*allowednodes
)
1733 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1734 int i
; /* index of *z in zonelist zones */
1735 int n
; /* node that zone *z is on */
1737 zlc
= zonelist
->zlcache_ptr
;
1741 i
= z
- zonelist
->_zonerefs
;
1744 /* This zone is worth trying if it is allowed but not full */
1745 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1749 * Given 'z' scanning a zonelist, set the corresponding bit in
1750 * zlc->fullzones, so that subsequent attempts to allocate a page
1751 * from that zone don't waste time re-examining it.
1753 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1755 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1756 int i
; /* index of *z in zonelist zones */
1758 zlc
= zonelist
->zlcache_ptr
;
1762 i
= z
- zonelist
->_zonerefs
;
1764 set_bit(i
, zlc
->fullzones
);
1768 * clear all zones full, called after direct reclaim makes progress so that
1769 * a zone that was recently full is not skipped over for up to a second
1771 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
1773 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1775 zlc
= zonelist
->zlcache_ptr
;
1779 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1782 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
1784 return node_isset(local_zone
->node
, zone
->zone_pgdat
->reclaim_nodes
);
1787 static void __paginginit
init_zone_allows_reclaim(int nid
)
1791 for_each_online_node(i
)
1792 if (node_distance(nid
, i
) <= RECLAIM_DISTANCE
)
1793 node_set(i
, NODE_DATA(nid
)->reclaim_nodes
);
1795 zone_reclaim_mode
= 1;
1798 #else /* CONFIG_NUMA */
1800 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1805 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1806 nodemask_t
*allowednodes
)
1811 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1815 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
1819 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
1824 static inline void init_zone_allows_reclaim(int nid
)
1827 #endif /* CONFIG_NUMA */
1830 * get_page_from_freelist goes through the zonelist trying to allocate
1833 static struct page
*
1834 get_page_from_freelist(gfp_t gfp_mask
, nodemask_t
*nodemask
, unsigned int order
,
1835 struct zonelist
*zonelist
, int high_zoneidx
, int alloc_flags
,
1836 struct zone
*preferred_zone
, int migratetype
)
1839 struct page
*page
= NULL
;
1842 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1843 int zlc_active
= 0; /* set if using zonelist_cache */
1844 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1846 classzone_idx
= zone_idx(preferred_zone
);
1849 * Scan zonelist, looking for a zone with enough free.
1850 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1852 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
1853 high_zoneidx
, nodemask
) {
1854 if (IS_ENABLED(CONFIG_NUMA
) && zlc_active
&&
1855 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1857 if ((alloc_flags
& ALLOC_CPUSET
) &&
1858 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1861 * When allocating a page cache page for writing, we
1862 * want to get it from a zone that is within its dirty
1863 * limit, such that no single zone holds more than its
1864 * proportional share of globally allowed dirty pages.
1865 * The dirty limits take into account the zone's
1866 * lowmem reserves and high watermark so that kswapd
1867 * should be able to balance it without having to
1868 * write pages from its LRU list.
1870 * This may look like it could increase pressure on
1871 * lower zones by failing allocations in higher zones
1872 * before they are full. But the pages that do spill
1873 * over are limited as the lower zones are protected
1874 * by this very same mechanism. It should not become
1875 * a practical burden to them.
1877 * XXX: For now, allow allocations to potentially
1878 * exceed the per-zone dirty limit in the slowpath
1879 * (ALLOC_WMARK_LOW unset) before going into reclaim,
1880 * which is important when on a NUMA setup the allowed
1881 * zones are together not big enough to reach the
1882 * global limit. The proper fix for these situations
1883 * will require awareness of zones in the
1884 * dirty-throttling and the flusher threads.
1886 if ((alloc_flags
& ALLOC_WMARK_LOW
) &&
1887 (gfp_mask
& __GFP_WRITE
) && !zone_dirty_ok(zone
))
1888 goto this_zone_full
;
1890 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
1891 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
1895 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
1896 if (zone_watermark_ok(zone
, order
, mark
,
1897 classzone_idx
, alloc_flags
))
1900 if (IS_ENABLED(CONFIG_NUMA
) &&
1901 !did_zlc_setup
&& nr_online_nodes
> 1) {
1903 * we do zlc_setup if there are multiple nodes
1904 * and before considering the first zone allowed
1907 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1912 if (zone_reclaim_mode
== 0 ||
1913 !zone_allows_reclaim(preferred_zone
, zone
))
1914 goto this_zone_full
;
1917 * As we may have just activated ZLC, check if the first
1918 * eligible zone has failed zone_reclaim recently.
1920 if (IS_ENABLED(CONFIG_NUMA
) && zlc_active
&&
1921 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1924 ret
= zone_reclaim(zone
, gfp_mask
, order
);
1926 case ZONE_RECLAIM_NOSCAN
:
1929 case ZONE_RECLAIM_FULL
:
1930 /* scanned but unreclaimable */
1933 /* did we reclaim enough */
1934 if (!zone_watermark_ok(zone
, order
, mark
,
1935 classzone_idx
, alloc_flags
))
1936 goto this_zone_full
;
1941 page
= buffered_rmqueue(preferred_zone
, zone
, order
,
1942 gfp_mask
, migratetype
);
1946 if (IS_ENABLED(CONFIG_NUMA
))
1947 zlc_mark_zone_full(zonelist
, z
);
1950 if (unlikely(IS_ENABLED(CONFIG_NUMA
) && page
== NULL
&& zlc_active
)) {
1951 /* Disable zlc cache for second zonelist scan */
1958 * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was
1959 * necessary to allocate the page. The expectation is
1960 * that the caller is taking steps that will free more
1961 * memory. The caller should avoid the page being used
1962 * for !PFMEMALLOC purposes.
1964 page
->pfmemalloc
= !!(alloc_flags
& ALLOC_NO_WATERMARKS
);
1970 * Large machines with many possible nodes should not always dump per-node
1971 * meminfo in irq context.
1973 static inline bool should_suppress_show_mem(void)
1978 ret
= in_interrupt();
1983 static DEFINE_RATELIMIT_STATE(nopage_rs
,
1984 DEFAULT_RATELIMIT_INTERVAL
,
1985 DEFAULT_RATELIMIT_BURST
);
1987 void warn_alloc_failed(gfp_t gfp_mask
, int order
, const char *fmt
, ...)
1989 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
1991 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
1992 debug_guardpage_minorder() > 0)
1996 * This documents exceptions given to allocations in certain
1997 * contexts that are allowed to allocate outside current's set
2000 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2001 if (test_thread_flag(TIF_MEMDIE
) ||
2002 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
2003 filter
&= ~SHOW_MEM_FILTER_NODES
;
2004 if (in_interrupt() || !(gfp_mask
& __GFP_WAIT
))
2005 filter
&= ~SHOW_MEM_FILTER_NODES
;
2008 struct va_format vaf
;
2011 va_start(args
, fmt
);
2016 pr_warn("%pV", &vaf
);
2021 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
2022 current
->comm
, order
, gfp_mask
);
2025 if (!should_suppress_show_mem())
2030 should_alloc_retry(gfp_t gfp_mask
, unsigned int order
,
2031 unsigned long did_some_progress
,
2032 unsigned long pages_reclaimed
)
2034 /* Do not loop if specifically requested */
2035 if (gfp_mask
& __GFP_NORETRY
)
2038 /* Always retry if specifically requested */
2039 if (gfp_mask
& __GFP_NOFAIL
)
2043 * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
2044 * making forward progress without invoking OOM. Suspend also disables
2045 * storage devices so kswapd will not help. Bail if we are suspending.
2047 if (!did_some_progress
&& pm_suspended_storage())
2051 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
2052 * means __GFP_NOFAIL, but that may not be true in other
2055 if (order
<= PAGE_ALLOC_COSTLY_ORDER
)
2059 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
2060 * specified, then we retry until we no longer reclaim any pages
2061 * (above), or we've reclaimed an order of pages at least as
2062 * large as the allocation's order. In both cases, if the
2063 * allocation still fails, we stop retrying.
2065 if (gfp_mask
& __GFP_REPEAT
&& pages_reclaimed
< (1 << order
))
2071 static inline struct page
*
2072 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
2073 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2074 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2079 /* Acquire the OOM killer lock for the zones in zonelist */
2080 if (!try_set_zonelist_oom(zonelist
, gfp_mask
)) {
2081 schedule_timeout_uninterruptible(1);
2086 * Go through the zonelist yet one more time, keep very high watermark
2087 * here, this is only to catch a parallel oom killing, we must fail if
2088 * we're still under heavy pressure.
2090 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
,
2091 order
, zonelist
, high_zoneidx
,
2092 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
,
2093 preferred_zone
, migratetype
);
2097 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2098 /* The OOM killer will not help higher order allocs */
2099 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2101 /* The OOM killer does not needlessly kill tasks for lowmem */
2102 if (high_zoneidx
< ZONE_NORMAL
)
2105 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
2106 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
2107 * The caller should handle page allocation failure by itself if
2108 * it specifies __GFP_THISNODE.
2109 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
2111 if (gfp_mask
& __GFP_THISNODE
)
2114 /* Exhausted what can be done so it's blamo time */
2115 out_of_memory(zonelist
, gfp_mask
, order
, nodemask
, false);
2118 clear_zonelist_oom(zonelist
, gfp_mask
);
2122 #ifdef CONFIG_COMPACTION
2123 /* Try memory compaction for high-order allocations before reclaim */
2124 static struct page
*
2125 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2126 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2127 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2128 int migratetype
, bool sync_migration
,
2129 bool *contended_compaction
, bool *deferred_compaction
,
2130 unsigned long *did_some_progress
)
2135 if (compaction_deferred(preferred_zone
, order
)) {
2136 *deferred_compaction
= true;
2140 current
->flags
|= PF_MEMALLOC
;
2141 *did_some_progress
= try_to_compact_pages(zonelist
, order
, gfp_mask
,
2142 nodemask
, sync_migration
,
2143 contended_compaction
);
2144 current
->flags
&= ~PF_MEMALLOC
;
2146 if (*did_some_progress
!= COMPACT_SKIPPED
) {
2149 /* Page migration frees to the PCP lists but we want merging */
2150 drain_pages(get_cpu());
2153 page
= get_page_from_freelist(gfp_mask
, nodemask
,
2154 order
, zonelist
, high_zoneidx
,
2155 alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2156 preferred_zone
, migratetype
);
2158 preferred_zone
->compact_blockskip_flush
= false;
2159 preferred_zone
->compact_considered
= 0;
2160 preferred_zone
->compact_defer_shift
= 0;
2161 if (order
>= preferred_zone
->compact_order_failed
)
2162 preferred_zone
->compact_order_failed
= order
+ 1;
2163 count_vm_event(COMPACTSUCCESS
);
2168 * It's bad if compaction run occurs and fails.
2169 * The most likely reason is that pages exist,
2170 * but not enough to satisfy watermarks.
2172 count_vm_event(COMPACTFAIL
);
2175 * As async compaction considers a subset of pageblocks, only
2176 * defer if the failure was a sync compaction failure.
2179 defer_compaction(preferred_zone
, order
);
2187 static inline struct page
*
2188 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2189 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2190 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2191 int migratetype
, bool sync_migration
,
2192 bool *contended_compaction
, bool *deferred_compaction
,
2193 unsigned long *did_some_progress
)
2197 #endif /* CONFIG_COMPACTION */
2199 /* Perform direct synchronous page reclaim */
2201 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
, struct zonelist
*zonelist
,
2202 nodemask_t
*nodemask
)
2204 struct reclaim_state reclaim_state
;
2209 /* We now go into synchronous reclaim */
2210 cpuset_memory_pressure_bump();
2211 current
->flags
|= PF_MEMALLOC
;
2212 lockdep_set_current_reclaim_state(gfp_mask
);
2213 reclaim_state
.reclaimed_slab
= 0;
2214 current
->reclaim_state
= &reclaim_state
;
2216 progress
= try_to_free_pages(zonelist
, order
, gfp_mask
, nodemask
);
2218 current
->reclaim_state
= NULL
;
2219 lockdep_clear_current_reclaim_state();
2220 current
->flags
&= ~PF_MEMALLOC
;
2227 /* The really slow allocator path where we enter direct reclaim */
2228 static inline struct page
*
2229 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
2230 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2231 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2232 int migratetype
, unsigned long *did_some_progress
)
2234 struct page
*page
= NULL
;
2235 bool drained
= false;
2237 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, zonelist
,
2239 if (unlikely(!(*did_some_progress
)))
2242 /* After successful reclaim, reconsider all zones for allocation */
2243 if (IS_ENABLED(CONFIG_NUMA
))
2244 zlc_clear_zones_full(zonelist
);
2247 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
2248 zonelist
, high_zoneidx
,
2249 alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2250 preferred_zone
, migratetype
);
2253 * If an allocation failed after direct reclaim, it could be because
2254 * pages are pinned on the per-cpu lists. Drain them and try again
2256 if (!page
&& !drained
) {
2266 * This is called in the allocator slow-path if the allocation request is of
2267 * sufficient urgency to ignore watermarks and take other desperate measures
2269 static inline struct page
*
2270 __alloc_pages_high_priority(gfp_t gfp_mask
, unsigned int order
,
2271 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2272 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2278 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
2279 zonelist
, high_zoneidx
, ALLOC_NO_WATERMARKS
,
2280 preferred_zone
, migratetype
);
2282 if (!page
&& gfp_mask
& __GFP_NOFAIL
)
2283 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2284 } while (!page
&& (gfp_mask
& __GFP_NOFAIL
));
2290 void wake_all_kswapd(unsigned int order
, struct zonelist
*zonelist
,
2291 enum zone_type high_zoneidx
,
2292 enum zone_type classzone_idx
)
2297 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
)
2298 wakeup_kswapd(zone
, order
, classzone_idx
);
2302 gfp_to_alloc_flags(gfp_t gfp_mask
)
2304 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
2305 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2307 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2308 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
2311 * The caller may dip into page reserves a bit more if the caller
2312 * cannot run direct reclaim, or if the caller has realtime scheduling
2313 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2314 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
2316 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
2320 * Not worth trying to allocate harder for
2321 * __GFP_NOMEMALLOC even if it can't schedule.
2323 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2324 alloc_flags
|= ALLOC_HARDER
;
2326 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
2327 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
2329 alloc_flags
&= ~ALLOC_CPUSET
;
2330 } else if (unlikely(rt_task(current
)) && !in_interrupt())
2331 alloc_flags
|= ALLOC_HARDER
;
2333 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
2334 if (gfp_mask
& __GFP_MEMALLOC
)
2335 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2336 else if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
2337 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2338 else if (!in_interrupt() &&
2339 ((current
->flags
& PF_MEMALLOC
) ||
2340 unlikely(test_thread_flag(TIF_MEMDIE
))))
2341 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2344 if (allocflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
2345 alloc_flags
|= ALLOC_CMA
;
2350 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
2352 return !!(gfp_to_alloc_flags(gfp_mask
) & ALLOC_NO_WATERMARKS
);
2355 static inline struct page
*
2356 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
2357 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2358 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2361 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2362 struct page
*page
= NULL
;
2364 unsigned long pages_reclaimed
= 0;
2365 unsigned long did_some_progress
;
2366 bool sync_migration
= false;
2367 bool deferred_compaction
= false;
2368 bool contended_compaction
= false;
2371 * In the slowpath, we sanity check order to avoid ever trying to
2372 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2373 * be using allocators in order of preference for an area that is
2376 if (order
>= MAX_ORDER
) {
2377 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
2382 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
2383 * __GFP_NOWARN set) should not cause reclaim since the subsystem
2384 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
2385 * using a larger set of nodes after it has established that the
2386 * allowed per node queues are empty and that nodes are
2389 if (IS_ENABLED(CONFIG_NUMA
) &&
2390 (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
2394 if (!(gfp_mask
& __GFP_NO_KSWAPD
))
2395 wake_all_kswapd(order
, zonelist
, high_zoneidx
,
2396 zone_idx(preferred_zone
));
2399 * OK, we're below the kswapd watermark and have kicked background
2400 * reclaim. Now things get more complex, so set up alloc_flags according
2401 * to how we want to proceed.
2403 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
2406 * Find the true preferred zone if the allocation is unconstrained by
2409 if (!(alloc_flags
& ALLOC_CPUSET
) && !nodemask
)
2410 first_zones_zonelist(zonelist
, high_zoneidx
, NULL
,
2414 /* This is the last chance, in general, before the goto nopage. */
2415 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
, zonelist
,
2416 high_zoneidx
, alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2417 preferred_zone
, migratetype
);
2421 /* Allocate without watermarks if the context allows */
2422 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
2424 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
2425 * the allocation is high priority and these type of
2426 * allocations are system rather than user orientated
2428 zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
2430 page
= __alloc_pages_high_priority(gfp_mask
, order
,
2431 zonelist
, high_zoneidx
, nodemask
,
2432 preferred_zone
, migratetype
);
2438 /* Atomic allocations - we can't balance anything */
2442 /* Avoid recursion of direct reclaim */
2443 if (current
->flags
& PF_MEMALLOC
)
2446 /* Avoid allocations with no watermarks from looping endlessly */
2447 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
2451 * Try direct compaction. The first pass is asynchronous. Subsequent
2452 * attempts after direct reclaim are synchronous
2454 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
2455 zonelist
, high_zoneidx
,
2457 alloc_flags
, preferred_zone
,
2458 migratetype
, sync_migration
,
2459 &contended_compaction
,
2460 &deferred_compaction
,
2461 &did_some_progress
);
2464 sync_migration
= true;
2467 * If compaction is deferred for high-order allocations, it is because
2468 * sync compaction recently failed. In this is the case and the caller
2469 * requested a movable allocation that does not heavily disrupt the
2470 * system then fail the allocation instead of entering direct reclaim.
2472 if ((deferred_compaction
|| contended_compaction
) &&
2473 (gfp_mask
& __GFP_NO_KSWAPD
))
2476 /* Try direct reclaim and then allocating */
2477 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
,
2478 zonelist
, high_zoneidx
,
2480 alloc_flags
, preferred_zone
,
2481 migratetype
, &did_some_progress
);
2486 * If we failed to make any progress reclaiming, then we are
2487 * running out of options and have to consider going OOM
2489 if (!did_some_progress
) {
2490 if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
2491 if (oom_killer_disabled
)
2493 /* Coredumps can quickly deplete all memory reserves */
2494 if ((current
->flags
& PF_DUMPCORE
) &&
2495 !(gfp_mask
& __GFP_NOFAIL
))
2497 page
= __alloc_pages_may_oom(gfp_mask
, order
,
2498 zonelist
, high_zoneidx
,
2499 nodemask
, preferred_zone
,
2504 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2506 * The oom killer is not called for high-order
2507 * allocations that may fail, so if no progress
2508 * is being made, there are no other options and
2509 * retrying is unlikely to help.
2511 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2514 * The oom killer is not called for lowmem
2515 * allocations to prevent needlessly killing
2518 if (high_zoneidx
< ZONE_NORMAL
)
2526 /* Check if we should retry the allocation */
2527 pages_reclaimed
+= did_some_progress
;
2528 if (should_alloc_retry(gfp_mask
, order
, did_some_progress
,
2530 /* Wait for some write requests to complete then retry */
2531 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2535 * High-order allocations do not necessarily loop after
2536 * direct reclaim and reclaim/compaction depends on compaction
2537 * being called after reclaim so call directly if necessary
2539 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
2540 zonelist
, high_zoneidx
,
2542 alloc_flags
, preferred_zone
,
2543 migratetype
, sync_migration
,
2544 &contended_compaction
,
2545 &deferred_compaction
,
2546 &did_some_progress
);
2552 warn_alloc_failed(gfp_mask
, order
, NULL
);
2555 if (kmemcheck_enabled
)
2556 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
2562 * This is the 'heart' of the zoned buddy allocator.
2565 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
2566 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
2568 enum zone_type high_zoneidx
= gfp_zone(gfp_mask
);
2569 struct zone
*preferred_zone
;
2570 struct page
*page
= NULL
;
2571 int migratetype
= allocflags_to_migratetype(gfp_mask
);
2572 unsigned int cpuset_mems_cookie
;
2573 int alloc_flags
= ALLOC_WMARK_LOW
|ALLOC_CPUSET
;
2574 struct mem_cgroup
*memcg
= NULL
;
2576 gfp_mask
&= gfp_allowed_mask
;
2578 lockdep_trace_alloc(gfp_mask
);
2580 might_sleep_if(gfp_mask
& __GFP_WAIT
);
2582 if (should_fail_alloc_page(gfp_mask
, order
))
2586 * Check the zones suitable for the gfp_mask contain at least one
2587 * valid zone. It's possible to have an empty zonelist as a result
2588 * of GFP_THISNODE and a memoryless node
2590 if (unlikely(!zonelist
->_zonerefs
->zone
))
2594 * Will only have any effect when __GFP_KMEMCG is set. This is
2595 * verified in the (always inline) callee
2597 if (!memcg_kmem_newpage_charge(gfp_mask
, &memcg
, order
))
2601 cpuset_mems_cookie
= get_mems_allowed();
2603 /* The preferred zone is used for statistics later */
2604 first_zones_zonelist(zonelist
, high_zoneidx
,
2605 nodemask
? : &cpuset_current_mems_allowed
,
2607 if (!preferred_zone
)
2611 if (allocflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
2612 alloc_flags
|= ALLOC_CMA
;
2614 /* First allocation attempt */
2615 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
, order
,
2616 zonelist
, high_zoneidx
, alloc_flags
,
2617 preferred_zone
, migratetype
);
2618 if (unlikely(!page
))
2619 page
= __alloc_pages_slowpath(gfp_mask
, order
,
2620 zonelist
, high_zoneidx
, nodemask
,
2621 preferred_zone
, migratetype
);
2623 trace_mm_page_alloc(page
, order
, gfp_mask
, migratetype
);
2627 * When updating a task's mems_allowed, it is possible to race with
2628 * parallel threads in such a way that an allocation can fail while
2629 * the mask is being updated. If a page allocation is about to fail,
2630 * check if the cpuset changed during allocation and if so, retry.
2632 if (unlikely(!put_mems_allowed(cpuset_mems_cookie
) && !page
))
2635 memcg_kmem_commit_charge(page
, memcg
, order
);
2639 EXPORT_SYMBOL(__alloc_pages_nodemask
);
2642 * Common helper functions.
2644 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
2649 * __get_free_pages() returns a 32-bit address, which cannot represent
2652 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
2654 page
= alloc_pages(gfp_mask
, order
);
2657 return (unsigned long) page_address(page
);
2659 EXPORT_SYMBOL(__get_free_pages
);
2661 unsigned long get_zeroed_page(gfp_t gfp_mask
)
2663 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
2665 EXPORT_SYMBOL(get_zeroed_page
);
2667 void __free_pages(struct page
*page
, unsigned int order
)
2669 if (put_page_testzero(page
)) {
2671 free_hot_cold_page(page
, 0);
2673 __free_pages_ok(page
, order
);
2677 EXPORT_SYMBOL(__free_pages
);
2679 void free_pages(unsigned long addr
, unsigned int order
)
2682 VM_BUG_ON(!virt_addr_valid((void *)addr
));
2683 __free_pages(virt_to_page((void *)addr
), order
);
2687 EXPORT_SYMBOL(free_pages
);
2690 * __free_memcg_kmem_pages and free_memcg_kmem_pages will free
2691 * pages allocated with __GFP_KMEMCG.
2693 * Those pages are accounted to a particular memcg, embedded in the
2694 * corresponding page_cgroup. To avoid adding a hit in the allocator to search
2695 * for that information only to find out that it is NULL for users who have no
2696 * interest in that whatsoever, we provide these functions.
2698 * The caller knows better which flags it relies on.
2700 void __free_memcg_kmem_pages(struct page
*page
, unsigned int order
)
2702 memcg_kmem_uncharge_pages(page
, order
);
2703 __free_pages(page
, order
);
2706 void free_memcg_kmem_pages(unsigned long addr
, unsigned int order
)
2709 VM_BUG_ON(!virt_addr_valid((void *)addr
));
2710 __free_memcg_kmem_pages(virt_to_page((void *)addr
), order
);
2714 static void *make_alloc_exact(unsigned long addr
, unsigned order
, size_t size
)
2717 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
2718 unsigned long used
= addr
+ PAGE_ALIGN(size
);
2720 split_page(virt_to_page((void *)addr
), order
);
2721 while (used
< alloc_end
) {
2726 return (void *)addr
;
2730 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2731 * @size: the number of bytes to allocate
2732 * @gfp_mask: GFP flags for the allocation
2734 * This function is similar to alloc_pages(), except that it allocates the
2735 * minimum number of pages to satisfy the request. alloc_pages() can only
2736 * allocate memory in power-of-two pages.
2738 * This function is also limited by MAX_ORDER.
2740 * Memory allocated by this function must be released by free_pages_exact().
2742 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
2744 unsigned int order
= get_order(size
);
2747 addr
= __get_free_pages(gfp_mask
, order
);
2748 return make_alloc_exact(addr
, order
, size
);
2750 EXPORT_SYMBOL(alloc_pages_exact
);
2753 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
2755 * @nid: the preferred node ID where memory should be allocated
2756 * @size: the number of bytes to allocate
2757 * @gfp_mask: GFP flags for the allocation
2759 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
2761 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
2764 void *alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
2766 unsigned order
= get_order(size
);
2767 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
2770 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
2772 EXPORT_SYMBOL(alloc_pages_exact_nid
);
2775 * free_pages_exact - release memory allocated via alloc_pages_exact()
2776 * @virt: the value returned by alloc_pages_exact.
2777 * @size: size of allocation, same value as passed to alloc_pages_exact().
2779 * Release the memory allocated by a previous call to alloc_pages_exact.
2781 void free_pages_exact(void *virt
, size_t size
)
2783 unsigned long addr
= (unsigned long)virt
;
2784 unsigned long end
= addr
+ PAGE_ALIGN(size
);
2786 while (addr
< end
) {
2791 EXPORT_SYMBOL(free_pages_exact
);
2793 static unsigned int nr_free_zone_pages(int offset
)
2798 /* Just pick one node, since fallback list is circular */
2799 unsigned int sum
= 0;
2801 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
2803 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
2804 unsigned long size
= zone
->present_pages
;
2805 unsigned long high
= high_wmark_pages(zone
);
2814 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
2816 unsigned int nr_free_buffer_pages(void)
2818 return nr_free_zone_pages(gfp_zone(GFP_USER
));
2820 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
2823 * Amount of free RAM allocatable within all zones
2825 unsigned int nr_free_pagecache_pages(void)
2827 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
2830 static inline void show_node(struct zone
*zone
)
2832 if (IS_ENABLED(CONFIG_NUMA
))
2833 printk("Node %d ", zone_to_nid(zone
));
2836 void si_meminfo(struct sysinfo
*val
)
2838 val
->totalram
= totalram_pages
;
2840 val
->freeram
= global_page_state(NR_FREE_PAGES
);
2841 val
->bufferram
= nr_blockdev_pages();
2842 val
->totalhigh
= totalhigh_pages
;
2843 val
->freehigh
= nr_free_highpages();
2844 val
->mem_unit
= PAGE_SIZE
;
2847 EXPORT_SYMBOL(si_meminfo
);
2850 void si_meminfo_node(struct sysinfo
*val
, int nid
)
2852 pg_data_t
*pgdat
= NODE_DATA(nid
);
2854 val
->totalram
= pgdat
->node_present_pages
;
2855 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
2856 #ifdef CONFIG_HIGHMEM
2857 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
2858 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
2864 val
->mem_unit
= PAGE_SIZE
;
2869 * Determine whether the node should be displayed or not, depending on whether
2870 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
2872 bool skip_free_areas_node(unsigned int flags
, int nid
)
2875 unsigned int cpuset_mems_cookie
;
2877 if (!(flags
& SHOW_MEM_FILTER_NODES
))
2881 cpuset_mems_cookie
= get_mems_allowed();
2882 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
2883 } while (!put_mems_allowed(cpuset_mems_cookie
));
2888 #define K(x) ((x) << (PAGE_SHIFT-10))
2890 static void show_migration_types(unsigned char type
)
2892 static const char types
[MIGRATE_TYPES
] = {
2893 [MIGRATE_UNMOVABLE
] = 'U',
2894 [MIGRATE_RECLAIMABLE
] = 'E',
2895 [MIGRATE_MOVABLE
] = 'M',
2896 [MIGRATE_RESERVE
] = 'R',
2898 [MIGRATE_CMA
] = 'C',
2900 [MIGRATE_ISOLATE
] = 'I',
2902 char tmp
[MIGRATE_TYPES
+ 1];
2906 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
2907 if (type
& (1 << i
))
2912 printk("(%s) ", tmp
);
2916 * Show free area list (used inside shift_scroll-lock stuff)
2917 * We also calculate the percentage fragmentation. We do this by counting the
2918 * memory on each free list with the exception of the first item on the list.
2919 * Suppresses nodes that are not allowed by current's cpuset if
2920 * SHOW_MEM_FILTER_NODES is passed.
2922 void show_free_areas(unsigned int filter
)
2927 for_each_populated_zone(zone
) {
2928 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
2931 printk("%s per-cpu:\n", zone
->name
);
2933 for_each_online_cpu(cpu
) {
2934 struct per_cpu_pageset
*pageset
;
2936 pageset
= per_cpu_ptr(zone
->pageset
, cpu
);
2938 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
2939 cpu
, pageset
->pcp
.high
,
2940 pageset
->pcp
.batch
, pageset
->pcp
.count
);
2944 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
2945 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
2947 " dirty:%lu writeback:%lu unstable:%lu\n"
2948 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2949 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
2951 global_page_state(NR_ACTIVE_ANON
),
2952 global_page_state(NR_INACTIVE_ANON
),
2953 global_page_state(NR_ISOLATED_ANON
),
2954 global_page_state(NR_ACTIVE_FILE
),
2955 global_page_state(NR_INACTIVE_FILE
),
2956 global_page_state(NR_ISOLATED_FILE
),
2957 global_page_state(NR_UNEVICTABLE
),
2958 global_page_state(NR_FILE_DIRTY
),
2959 global_page_state(NR_WRITEBACK
),
2960 global_page_state(NR_UNSTABLE_NFS
),
2961 global_page_state(NR_FREE_PAGES
),
2962 global_page_state(NR_SLAB_RECLAIMABLE
),
2963 global_page_state(NR_SLAB_UNRECLAIMABLE
),
2964 global_page_state(NR_FILE_MAPPED
),
2965 global_page_state(NR_SHMEM
),
2966 global_page_state(NR_PAGETABLE
),
2967 global_page_state(NR_BOUNCE
),
2968 global_page_state(NR_FREE_CMA_PAGES
));
2970 for_each_populated_zone(zone
) {
2973 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
2981 " active_anon:%lukB"
2982 " inactive_anon:%lukB"
2983 " active_file:%lukB"
2984 " inactive_file:%lukB"
2985 " unevictable:%lukB"
2986 " isolated(anon):%lukB"
2987 " isolated(file):%lukB"
2995 " slab_reclaimable:%lukB"
2996 " slab_unreclaimable:%lukB"
2997 " kernel_stack:%lukB"
3002 " writeback_tmp:%lukB"
3003 " pages_scanned:%lu"
3004 " all_unreclaimable? %s"
3007 K(zone_page_state(zone
, NR_FREE_PAGES
)),
3008 K(min_wmark_pages(zone
)),
3009 K(low_wmark_pages(zone
)),
3010 K(high_wmark_pages(zone
)),
3011 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
3012 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
3013 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
3014 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
3015 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
3016 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
3017 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
3018 K(zone
->present_pages
),
3019 K(zone
->managed_pages
),
3020 K(zone_page_state(zone
, NR_MLOCK
)),
3021 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
3022 K(zone_page_state(zone
, NR_WRITEBACK
)),
3023 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
3024 K(zone_page_state(zone
, NR_SHMEM
)),
3025 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
3026 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
3027 zone_page_state(zone
, NR_KERNEL_STACK
) *
3029 K(zone_page_state(zone
, NR_PAGETABLE
)),
3030 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
3031 K(zone_page_state(zone
, NR_BOUNCE
)),
3032 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)),
3033 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
3034 zone
->pages_scanned
,
3035 (zone
->all_unreclaimable
? "yes" : "no")
3037 printk("lowmem_reserve[]:");
3038 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3039 printk(" %lu", zone
->lowmem_reserve
[i
]);
3043 for_each_populated_zone(zone
) {
3044 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
3045 unsigned char types
[MAX_ORDER
];
3047 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3050 printk("%s: ", zone
->name
);
3052 spin_lock_irqsave(&zone
->lock
, flags
);
3053 for (order
= 0; order
< MAX_ORDER
; order
++) {
3054 struct free_area
*area
= &zone
->free_area
[order
];
3057 nr
[order
] = area
->nr_free
;
3058 total
+= nr
[order
] << order
;
3061 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
3062 if (!list_empty(&area
->free_list
[type
]))
3063 types
[order
] |= 1 << type
;
3066 spin_unlock_irqrestore(&zone
->lock
, flags
);
3067 for (order
= 0; order
< MAX_ORDER
; order
++) {
3068 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
3070 show_migration_types(types
[order
]);
3072 printk("= %lukB\n", K(total
));
3075 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
3077 show_swap_cache_info();
3080 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
3082 zoneref
->zone
= zone
;
3083 zoneref
->zone_idx
= zone_idx(zone
);
3087 * Builds allocation fallback zone lists.
3089 * Add all populated zones of a node to the zonelist.
3091 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
3092 int nr_zones
, enum zone_type zone_type
)
3096 BUG_ON(zone_type
>= MAX_NR_ZONES
);
3101 zone
= pgdat
->node_zones
+ zone_type
;
3102 if (populated_zone(zone
)) {
3103 zoneref_set_zone(zone
,
3104 &zonelist
->_zonerefs
[nr_zones
++]);
3105 check_highest_zone(zone_type
);
3108 } while (zone_type
);
3115 * 0 = automatic detection of better ordering.
3116 * 1 = order by ([node] distance, -zonetype)
3117 * 2 = order by (-zonetype, [node] distance)
3119 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3120 * the same zonelist. So only NUMA can configure this param.
3122 #define ZONELIST_ORDER_DEFAULT 0
3123 #define ZONELIST_ORDER_NODE 1
3124 #define ZONELIST_ORDER_ZONE 2
3126 /* zonelist order in the kernel.
3127 * set_zonelist_order() will set this to NODE or ZONE.
3129 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3130 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
3134 /* The value user specified ....changed by config */
3135 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3136 /* string for sysctl */
3137 #define NUMA_ZONELIST_ORDER_LEN 16
3138 char numa_zonelist_order
[16] = "default";
3141 * interface for configure zonelist ordering.
3142 * command line option "numa_zonelist_order"
3143 * = "[dD]efault - default, automatic configuration.
3144 * = "[nN]ode - order by node locality, then by zone within node
3145 * = "[zZ]one - order by zone, then by locality within zone
3148 static int __parse_numa_zonelist_order(char *s
)
3150 if (*s
== 'd' || *s
== 'D') {
3151 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3152 } else if (*s
== 'n' || *s
== 'N') {
3153 user_zonelist_order
= ZONELIST_ORDER_NODE
;
3154 } else if (*s
== 'z' || *s
== 'Z') {
3155 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
3158 "Ignoring invalid numa_zonelist_order value: "
3165 static __init
int setup_numa_zonelist_order(char *s
)
3172 ret
= __parse_numa_zonelist_order(s
);
3174 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
3178 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
3181 * sysctl handler for numa_zonelist_order
3183 int numa_zonelist_order_handler(ctl_table
*table
, int write
,
3184 void __user
*buffer
, size_t *length
,
3187 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
3189 static DEFINE_MUTEX(zl_order_mutex
);
3191 mutex_lock(&zl_order_mutex
);
3193 strcpy(saved_string
, (char*)table
->data
);
3194 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
3198 int oldval
= user_zonelist_order
;
3199 if (__parse_numa_zonelist_order((char*)table
->data
)) {
3201 * bogus value. restore saved string
3203 strncpy((char*)table
->data
, saved_string
,
3204 NUMA_ZONELIST_ORDER_LEN
);
3205 user_zonelist_order
= oldval
;
3206 } else if (oldval
!= user_zonelist_order
) {
3207 mutex_lock(&zonelists_mutex
);
3208 build_all_zonelists(NULL
, NULL
);
3209 mutex_unlock(&zonelists_mutex
);
3213 mutex_unlock(&zl_order_mutex
);
3218 #define MAX_NODE_LOAD (nr_online_nodes)
3219 static int node_load
[MAX_NUMNODES
];
3222 * find_next_best_node - find the next node that should appear in a given node's fallback list
3223 * @node: node whose fallback list we're appending
3224 * @used_node_mask: nodemask_t of already used nodes
3226 * We use a number of factors to determine which is the next node that should
3227 * appear on a given node's fallback list. The node should not have appeared
3228 * already in @node's fallback list, and it should be the next closest node
3229 * according to the distance array (which contains arbitrary distance values
3230 * from each node to each node in the system), and should also prefer nodes
3231 * with no CPUs, since presumably they'll have very little allocation pressure
3232 * on them otherwise.
3233 * It returns -1 if no node is found.
3235 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
3238 int min_val
= INT_MAX
;
3240 const struct cpumask
*tmp
= cpumask_of_node(0);
3242 /* Use the local node if we haven't already */
3243 if (!node_isset(node
, *used_node_mask
)) {
3244 node_set(node
, *used_node_mask
);
3248 for_each_node_state(n
, N_MEMORY
) {
3250 /* Don't want a node to appear more than once */
3251 if (node_isset(n
, *used_node_mask
))
3254 /* Use the distance array to find the distance */
3255 val
= node_distance(node
, n
);
3257 /* Penalize nodes under us ("prefer the next node") */
3260 /* Give preference to headless and unused nodes */
3261 tmp
= cpumask_of_node(n
);
3262 if (!cpumask_empty(tmp
))
3263 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
3265 /* Slight preference for less loaded node */
3266 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
3267 val
+= node_load
[n
];
3269 if (val
< min_val
) {
3276 node_set(best_node
, *used_node_mask
);
3283 * Build zonelists ordered by node and zones within node.
3284 * This results in maximum locality--normal zone overflows into local
3285 * DMA zone, if any--but risks exhausting DMA zone.
3287 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
3290 struct zonelist
*zonelist
;
3292 zonelist
= &pgdat
->node_zonelists
[0];
3293 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
3295 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3297 zonelist
->_zonerefs
[j
].zone
= NULL
;
3298 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3302 * Build gfp_thisnode zonelists
3304 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
3307 struct zonelist
*zonelist
;
3309 zonelist
= &pgdat
->node_zonelists
[1];
3310 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
3311 zonelist
->_zonerefs
[j
].zone
= NULL
;
3312 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3316 * Build zonelists ordered by zone and nodes within zones.
3317 * This results in conserving DMA zone[s] until all Normal memory is
3318 * exhausted, but results in overflowing to remote node while memory
3319 * may still exist in local DMA zone.
3321 static int node_order
[MAX_NUMNODES
];
3323 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
3326 int zone_type
; /* needs to be signed */
3328 struct zonelist
*zonelist
;
3330 zonelist
= &pgdat
->node_zonelists
[0];
3332 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
3333 for (j
= 0; j
< nr_nodes
; j
++) {
3334 node
= node_order
[j
];
3335 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
3336 if (populated_zone(z
)) {
3338 &zonelist
->_zonerefs
[pos
++]);
3339 check_highest_zone(zone_type
);
3343 zonelist
->_zonerefs
[pos
].zone
= NULL
;
3344 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
3347 static int default_zonelist_order(void)
3350 unsigned long low_kmem_size
,total_size
;
3354 * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
3355 * If they are really small and used heavily, the system can fall
3356 * into OOM very easily.
3357 * This function detect ZONE_DMA/DMA32 size and configures zone order.
3359 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
3362 for_each_online_node(nid
) {
3363 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
3364 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
3365 if (populated_zone(z
)) {
3366 if (zone_type
< ZONE_NORMAL
)
3367 low_kmem_size
+= z
->present_pages
;
3368 total_size
+= z
->present_pages
;
3369 } else if (zone_type
== ZONE_NORMAL
) {
3371 * If any node has only lowmem, then node order
3372 * is preferred to allow kernel allocations
3373 * locally; otherwise, they can easily infringe
3374 * on other nodes when there is an abundance of
3375 * lowmem available to allocate from.
3377 return ZONELIST_ORDER_NODE
;
3381 if (!low_kmem_size
|| /* there are no DMA area. */
3382 low_kmem_size
> total_size
/2) /* DMA/DMA32 is big. */
3383 return ZONELIST_ORDER_NODE
;
3385 * look into each node's config.
3386 * If there is a node whose DMA/DMA32 memory is very big area on
3387 * local memory, NODE_ORDER may be suitable.
3389 average_size
= total_size
/
3390 (nodes_weight(node_states
[N_MEMORY
]) + 1);
3391 for_each_online_node(nid
) {
3394 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
3395 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
3396 if (populated_zone(z
)) {
3397 if (zone_type
< ZONE_NORMAL
)
3398 low_kmem_size
+= z
->present_pages
;
3399 total_size
+= z
->present_pages
;
3402 if (low_kmem_size
&&
3403 total_size
> average_size
&& /* ignore small node */
3404 low_kmem_size
> total_size
* 70/100)
3405 return ZONELIST_ORDER_NODE
;
3407 return ZONELIST_ORDER_ZONE
;
3410 static void set_zonelist_order(void)
3412 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
3413 current_zonelist_order
= default_zonelist_order();
3415 current_zonelist_order
= user_zonelist_order
;
3418 static void build_zonelists(pg_data_t
*pgdat
)
3422 nodemask_t used_mask
;
3423 int local_node
, prev_node
;
3424 struct zonelist
*zonelist
;
3425 int order
= current_zonelist_order
;
3427 /* initialize zonelists */
3428 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
3429 zonelist
= pgdat
->node_zonelists
+ i
;
3430 zonelist
->_zonerefs
[0].zone
= NULL
;
3431 zonelist
->_zonerefs
[0].zone_idx
= 0;
3434 /* NUMA-aware ordering of nodes */
3435 local_node
= pgdat
->node_id
;
3436 load
= nr_online_nodes
;
3437 prev_node
= local_node
;
3438 nodes_clear(used_mask
);
3440 memset(node_order
, 0, sizeof(node_order
));
3443 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
3445 * We don't want to pressure a particular node.
3446 * So adding penalty to the first node in same
3447 * distance group to make it round-robin.
3449 if (node_distance(local_node
, node
) !=
3450 node_distance(local_node
, prev_node
))
3451 node_load
[node
] = load
;
3455 if (order
== ZONELIST_ORDER_NODE
)
3456 build_zonelists_in_node_order(pgdat
, node
);
3458 node_order
[j
++] = node
; /* remember order */
3461 if (order
== ZONELIST_ORDER_ZONE
) {
3462 /* calculate node order -- i.e., DMA last! */
3463 build_zonelists_in_zone_order(pgdat
, j
);
3466 build_thisnode_zonelists(pgdat
);
3469 /* Construct the zonelist performance cache - see further mmzone.h */
3470 static void build_zonelist_cache(pg_data_t
*pgdat
)
3472 struct zonelist
*zonelist
;
3473 struct zonelist_cache
*zlc
;
3476 zonelist
= &pgdat
->node_zonelists
[0];
3477 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
3478 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
3479 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
3480 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
3483 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3485 * Return node id of node used for "local" allocations.
3486 * I.e., first node id of first zone in arg node's generic zonelist.
3487 * Used for initializing percpu 'numa_mem', which is used primarily
3488 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3490 int local_memory_node(int node
)
3494 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
3495 gfp_zone(GFP_KERNEL
),
3502 #else /* CONFIG_NUMA */
3504 static void set_zonelist_order(void)
3506 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
3509 static void build_zonelists(pg_data_t
*pgdat
)
3511 int node
, local_node
;
3513 struct zonelist
*zonelist
;
3515 local_node
= pgdat
->node_id
;
3517 zonelist
= &pgdat
->node_zonelists
[0];
3518 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
3521 * Now we build the zonelist so that it contains the zones
3522 * of all the other nodes.
3523 * We don't want to pressure a particular node, so when
3524 * building the zones for node N, we make sure that the
3525 * zones coming right after the local ones are those from
3526 * node N+1 (modulo N)
3528 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
3529 if (!node_online(node
))
3531 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3534 for (node
= 0; node
< local_node
; node
++) {
3535 if (!node_online(node
))
3537 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3541 zonelist
->_zonerefs
[j
].zone
= NULL
;
3542 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3545 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3546 static void build_zonelist_cache(pg_data_t
*pgdat
)
3548 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
3551 #endif /* CONFIG_NUMA */
3554 * Boot pageset table. One per cpu which is going to be used for all
3555 * zones and all nodes. The parameters will be set in such a way
3556 * that an item put on a list will immediately be handed over to
3557 * the buddy list. This is safe since pageset manipulation is done
3558 * with interrupts disabled.
3560 * The boot_pagesets must be kept even after bootup is complete for
3561 * unused processors and/or zones. They do play a role for bootstrapping
3562 * hotplugged processors.
3564 * zoneinfo_show() and maybe other functions do
3565 * not check if the processor is online before following the pageset pointer.
3566 * Other parts of the kernel may not check if the zone is available.
3568 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
3569 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
3570 static void setup_zone_pageset(struct zone
*zone
);
3573 * Global mutex to protect against size modification of zonelists
3574 * as well as to serialize pageset setup for the new populated zone.
3576 DEFINE_MUTEX(zonelists_mutex
);
3578 /* return values int ....just for stop_machine() */
3579 static int __build_all_zonelists(void *data
)
3583 pg_data_t
*self
= data
;
3586 memset(node_load
, 0, sizeof(node_load
));
3589 if (self
&& !node_online(self
->node_id
)) {
3590 build_zonelists(self
);
3591 build_zonelist_cache(self
);
3594 for_each_online_node(nid
) {
3595 pg_data_t
*pgdat
= NODE_DATA(nid
);
3597 build_zonelists(pgdat
);
3598 build_zonelist_cache(pgdat
);
3602 * Initialize the boot_pagesets that are going to be used
3603 * for bootstrapping processors. The real pagesets for
3604 * each zone will be allocated later when the per cpu
3605 * allocator is available.
3607 * boot_pagesets are used also for bootstrapping offline
3608 * cpus if the system is already booted because the pagesets
3609 * are needed to initialize allocators on a specific cpu too.
3610 * F.e. the percpu allocator needs the page allocator which
3611 * needs the percpu allocator in order to allocate its pagesets
3612 * (a chicken-egg dilemma).
3614 for_each_possible_cpu(cpu
) {
3615 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
3617 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3619 * We now know the "local memory node" for each node--
3620 * i.e., the node of the first zone in the generic zonelist.
3621 * Set up numa_mem percpu variable for on-line cpus. During
3622 * boot, only the boot cpu should be on-line; we'll init the
3623 * secondary cpus' numa_mem as they come on-line. During
3624 * node/memory hotplug, we'll fixup all on-line cpus.
3626 if (cpu_online(cpu
))
3627 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
3635 * Called with zonelists_mutex held always
3636 * unless system_state == SYSTEM_BOOTING.
3638 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
3640 set_zonelist_order();
3642 if (system_state
== SYSTEM_BOOTING
) {
3643 __build_all_zonelists(NULL
);
3644 mminit_verify_zonelist();
3645 cpuset_init_current_mems_allowed();
3647 /* we have to stop all cpus to guarantee there is no user
3649 #ifdef CONFIG_MEMORY_HOTPLUG
3651 setup_zone_pageset(zone
);
3653 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
3654 /* cpuset refresh routine should be here */
3656 vm_total_pages
= nr_free_pagecache_pages();
3658 * Disable grouping by mobility if the number of pages in the
3659 * system is too low to allow the mechanism to work. It would be
3660 * more accurate, but expensive to check per-zone. This check is
3661 * made on memory-hotadd so a system can start with mobility
3662 * disabled and enable it later
3664 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
3665 page_group_by_mobility_disabled
= 1;
3667 page_group_by_mobility_disabled
= 0;
3669 printk("Built %i zonelists in %s order, mobility grouping %s. "
3670 "Total pages: %ld\n",
3672 zonelist_order_name
[current_zonelist_order
],
3673 page_group_by_mobility_disabled
? "off" : "on",
3676 printk("Policy zone: %s\n", zone_names
[policy_zone
]);
3681 * Helper functions to size the waitqueue hash table.
3682 * Essentially these want to choose hash table sizes sufficiently
3683 * large so that collisions trying to wait on pages are rare.
3684 * But in fact, the number of active page waitqueues on typical
3685 * systems is ridiculously low, less than 200. So this is even
3686 * conservative, even though it seems large.
3688 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3689 * waitqueues, i.e. the size of the waitq table given the number of pages.
3691 #define PAGES_PER_WAITQUEUE 256
3693 #ifndef CONFIG_MEMORY_HOTPLUG
3694 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3696 unsigned long size
= 1;
3698 pages
/= PAGES_PER_WAITQUEUE
;
3700 while (size
< pages
)
3704 * Once we have dozens or even hundreds of threads sleeping
3705 * on IO we've got bigger problems than wait queue collision.
3706 * Limit the size of the wait table to a reasonable size.
3708 size
= min(size
, 4096UL);
3710 return max(size
, 4UL);
3714 * A zone's size might be changed by hot-add, so it is not possible to determine
3715 * a suitable size for its wait_table. So we use the maximum size now.
3717 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
3719 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
3720 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3721 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
3723 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3724 * or more by the traditional way. (See above). It equals:
3726 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
3727 * ia64(16K page size) : = ( 8G + 4M)byte.
3728 * powerpc (64K page size) : = (32G +16M)byte.
3730 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3737 * This is an integer logarithm so that shifts can be used later
3738 * to extract the more random high bits from the multiplicative
3739 * hash function before the remainder is taken.
3741 static inline unsigned long wait_table_bits(unsigned long size
)
3746 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
3749 * Check if a pageblock contains reserved pages
3751 static int pageblock_is_reserved(unsigned long start_pfn
, unsigned long end_pfn
)
3755 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
3756 if (!pfn_valid_within(pfn
) || PageReserved(pfn_to_page(pfn
)))
3763 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3764 * of blocks reserved is based on min_wmark_pages(zone). The memory within
3765 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3766 * higher will lead to a bigger reserve which will get freed as contiguous
3767 * blocks as reclaim kicks in
3769 static void setup_zone_migrate_reserve(struct zone
*zone
)
3771 unsigned long start_pfn
, pfn
, end_pfn
, block_end_pfn
;
3773 unsigned long block_migratetype
;
3777 * Get the start pfn, end pfn and the number of blocks to reserve
3778 * We have to be careful to be aligned to pageblock_nr_pages to
3779 * make sure that we always check pfn_valid for the first page in
3782 start_pfn
= zone
->zone_start_pfn
;
3783 end_pfn
= start_pfn
+ zone
->spanned_pages
;
3784 start_pfn
= roundup(start_pfn
, pageblock_nr_pages
);
3785 reserve
= roundup(min_wmark_pages(zone
), pageblock_nr_pages
) >>
3789 * Reserve blocks are generally in place to help high-order atomic
3790 * allocations that are short-lived. A min_free_kbytes value that
3791 * would result in more than 2 reserve blocks for atomic allocations
3792 * is assumed to be in place to help anti-fragmentation for the
3793 * future allocation of hugepages at runtime.
3795 reserve
= min(2, reserve
);
3797 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
3798 if (!pfn_valid(pfn
))
3800 page
= pfn_to_page(pfn
);
3802 /* Watch out for overlapping nodes */
3803 if (page_to_nid(page
) != zone_to_nid(zone
))
3806 block_migratetype
= get_pageblock_migratetype(page
);
3808 /* Only test what is necessary when the reserves are not met */
3811 * Blocks with reserved pages will never free, skip
3814 block_end_pfn
= min(pfn
+ pageblock_nr_pages
, end_pfn
);
3815 if (pageblock_is_reserved(pfn
, block_end_pfn
))
3818 /* If this block is reserved, account for it */
3819 if (block_migratetype
== MIGRATE_RESERVE
) {
3824 /* Suitable for reserving if this block is movable */
3825 if (block_migratetype
== MIGRATE_MOVABLE
) {
3826 set_pageblock_migratetype(page
,
3828 move_freepages_block(zone
, page
,
3836 * If the reserve is met and this is a previous reserved block,
3839 if (block_migratetype
== MIGRATE_RESERVE
) {
3840 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3841 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
3847 * Initially all pages are reserved - free ones are freed
3848 * up by free_all_bootmem() once the early boot process is
3849 * done. Non-atomic initialization, single-pass.
3851 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
3852 unsigned long start_pfn
, enum memmap_context context
)
3855 unsigned long end_pfn
= start_pfn
+ size
;
3859 if (highest_memmap_pfn
< end_pfn
- 1)
3860 highest_memmap_pfn
= end_pfn
- 1;
3862 z
= &NODE_DATA(nid
)->node_zones
[zone
];
3863 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
3865 * There can be holes in boot-time mem_map[]s
3866 * handed to this function. They do not
3867 * exist on hotplugged memory.
3869 if (context
== MEMMAP_EARLY
) {
3870 if (!early_pfn_valid(pfn
))
3872 if (!early_pfn_in_nid(pfn
, nid
))
3875 page
= pfn_to_page(pfn
);
3876 set_page_links(page
, zone
, nid
, pfn
);
3877 mminit_verify_page_links(page
, zone
, nid
, pfn
);
3878 init_page_count(page
);
3879 reset_page_mapcount(page
);
3880 reset_page_last_nid(page
);
3881 SetPageReserved(page
);
3883 * Mark the block movable so that blocks are reserved for
3884 * movable at startup. This will force kernel allocations
3885 * to reserve their blocks rather than leaking throughout
3886 * the address space during boot when many long-lived
3887 * kernel allocations are made. Later some blocks near
3888 * the start are marked MIGRATE_RESERVE by
3889 * setup_zone_migrate_reserve()
3891 * bitmap is created for zone's valid pfn range. but memmap
3892 * can be created for invalid pages (for alignment)
3893 * check here not to call set_pageblock_migratetype() against
3896 if ((z
->zone_start_pfn
<= pfn
)
3897 && (pfn
< z
->zone_start_pfn
+ z
->spanned_pages
)
3898 && !(pfn
& (pageblock_nr_pages
- 1)))
3899 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3901 INIT_LIST_HEAD(&page
->lru
);
3902 #ifdef WANT_PAGE_VIRTUAL
3903 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
3904 if (!is_highmem_idx(zone
))
3905 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
3910 static void __meminit
zone_init_free_lists(struct zone
*zone
)
3913 for_each_migratetype_order(order
, t
) {
3914 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
3915 zone
->free_area
[order
].nr_free
= 0;
3919 #ifndef __HAVE_ARCH_MEMMAP_INIT
3920 #define memmap_init(size, nid, zone, start_pfn) \
3921 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
3924 static int __meminit
zone_batchsize(struct zone
*zone
)
3930 * The per-cpu-pages pools are set to around 1000th of the
3931 * size of the zone. But no more than 1/2 of a meg.
3933 * OK, so we don't know how big the cache is. So guess.
3935 batch
= zone
->present_pages
/ 1024;
3936 if (batch
* PAGE_SIZE
> 512 * 1024)
3937 batch
= (512 * 1024) / PAGE_SIZE
;
3938 batch
/= 4; /* We effectively *= 4 below */
3943 * Clamp the batch to a 2^n - 1 value. Having a power
3944 * of 2 value was found to be more likely to have
3945 * suboptimal cache aliasing properties in some cases.
3947 * For example if 2 tasks are alternately allocating
3948 * batches of pages, one task can end up with a lot
3949 * of pages of one half of the possible page colors
3950 * and the other with pages of the other colors.
3952 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
3957 /* The deferral and batching of frees should be suppressed under NOMMU
3960 * The problem is that NOMMU needs to be able to allocate large chunks
3961 * of contiguous memory as there's no hardware page translation to
3962 * assemble apparent contiguous memory from discontiguous pages.
3964 * Queueing large contiguous runs of pages for batching, however,
3965 * causes the pages to actually be freed in smaller chunks. As there
3966 * can be a significant delay between the individual batches being
3967 * recycled, this leads to the once large chunks of space being
3968 * fragmented and becoming unavailable for high-order allocations.
3974 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
3976 struct per_cpu_pages
*pcp
;
3979 memset(p
, 0, sizeof(*p
));
3983 pcp
->high
= 6 * batch
;
3984 pcp
->batch
= max(1UL, 1 * batch
);
3985 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
3986 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
3990 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
3991 * to the value high for the pageset p.
3994 static void setup_pagelist_highmark(struct per_cpu_pageset
*p
,
3997 struct per_cpu_pages
*pcp
;
4001 pcp
->batch
= max(1UL, high
/4);
4002 if ((high
/4) > (PAGE_SHIFT
* 8))
4003 pcp
->batch
= PAGE_SHIFT
* 8;
4006 static void __meminit
setup_zone_pageset(struct zone
*zone
)
4010 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
4012 for_each_possible_cpu(cpu
) {
4013 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
4015 setup_pageset(pcp
, zone_batchsize(zone
));
4017 if (percpu_pagelist_fraction
)
4018 setup_pagelist_highmark(pcp
,
4019 (zone
->present_pages
/
4020 percpu_pagelist_fraction
));
4025 * Allocate per cpu pagesets and initialize them.
4026 * Before this call only boot pagesets were available.
4028 void __init
setup_per_cpu_pageset(void)
4032 for_each_populated_zone(zone
)
4033 setup_zone_pageset(zone
);
4036 static noinline __init_refok
4037 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
4040 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
4044 * The per-page waitqueue mechanism uses hashed waitqueues
4047 zone
->wait_table_hash_nr_entries
=
4048 wait_table_hash_nr_entries(zone_size_pages
);
4049 zone
->wait_table_bits
=
4050 wait_table_bits(zone
->wait_table_hash_nr_entries
);
4051 alloc_size
= zone
->wait_table_hash_nr_entries
4052 * sizeof(wait_queue_head_t
);
4054 if (!slab_is_available()) {
4055 zone
->wait_table
= (wait_queue_head_t
*)
4056 alloc_bootmem_node_nopanic(pgdat
, alloc_size
);
4059 * This case means that a zone whose size was 0 gets new memory
4060 * via memory hot-add.
4061 * But it may be the case that a new node was hot-added. In
4062 * this case vmalloc() will not be able to use this new node's
4063 * memory - this wait_table must be initialized to use this new
4064 * node itself as well.
4065 * To use this new node's memory, further consideration will be
4068 zone
->wait_table
= vmalloc(alloc_size
);
4070 if (!zone
->wait_table
)
4073 for(i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
4074 init_waitqueue_head(zone
->wait_table
+ i
);
4079 static __meminit
void zone_pcp_init(struct zone
*zone
)
4082 * per cpu subsystem is not up at this point. The following code
4083 * relies on the ability of the linker to provide the
4084 * offset of a (static) per cpu variable into the per cpu area.
4086 zone
->pageset
= &boot_pageset
;
4088 if (zone
->present_pages
)
4089 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
4090 zone
->name
, zone
->present_pages
,
4091 zone_batchsize(zone
));
4094 int __meminit
init_currently_empty_zone(struct zone
*zone
,
4095 unsigned long zone_start_pfn
,
4097 enum memmap_context context
)
4099 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
4101 ret
= zone_wait_table_init(zone
, size
);
4104 pgdat
->nr_zones
= zone_idx(zone
) + 1;
4106 zone
->zone_start_pfn
= zone_start_pfn
;
4108 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
4109 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4111 (unsigned long)zone_idx(zone
),
4112 zone_start_pfn
, (zone_start_pfn
+ size
));
4114 zone_init_free_lists(zone
);
4119 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4120 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4122 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4123 * Architectures may implement their own version but if add_active_range()
4124 * was used and there are no special requirements, this is a convenient
4127 int __meminit
__early_pfn_to_nid(unsigned long pfn
)
4129 unsigned long start_pfn
, end_pfn
;
4132 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
4133 if (start_pfn
<= pfn
&& pfn
< end_pfn
)
4135 /* This is a memory hole */
4138 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4140 int __meminit
early_pfn_to_nid(unsigned long pfn
)
4144 nid
= __early_pfn_to_nid(pfn
);
4147 /* just returns 0 */
4151 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
4152 bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
4156 nid
= __early_pfn_to_nid(pfn
);
4157 if (nid
>= 0 && nid
!= node
)
4164 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
4165 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4166 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
4168 * If an architecture guarantees that all ranges registered with
4169 * add_active_ranges() contain no holes and may be freed, this
4170 * this function may be used instead of calling free_bootmem() manually.
4172 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
4174 unsigned long start_pfn
, end_pfn
;
4177 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
4178 start_pfn
= min(start_pfn
, max_low_pfn
);
4179 end_pfn
= min(end_pfn
, max_low_pfn
);
4181 if (start_pfn
< end_pfn
)
4182 free_bootmem_node(NODE_DATA(this_nid
),
4183 PFN_PHYS(start_pfn
),
4184 (end_pfn
- start_pfn
) << PAGE_SHIFT
);
4189 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4190 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4192 * If an architecture guarantees that all ranges registered with
4193 * add_active_ranges() contain no holes and may be freed, this
4194 * function may be used instead of calling memory_present() manually.
4196 void __init
sparse_memory_present_with_active_regions(int nid
)
4198 unsigned long start_pfn
, end_pfn
;
4201 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
4202 memory_present(this_nid
, start_pfn
, end_pfn
);
4206 * get_pfn_range_for_nid - Return the start and end page frames for a node
4207 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4208 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
4209 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
4211 * It returns the start and end page frame of a node based on information
4212 * provided by an arch calling add_active_range(). If called for a node
4213 * with no available memory, a warning is printed and the start and end
4216 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
4217 unsigned long *start_pfn
, unsigned long *end_pfn
)
4219 unsigned long this_start_pfn
, this_end_pfn
;
4225 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
4226 *start_pfn
= min(*start_pfn
, this_start_pfn
);
4227 *end_pfn
= max(*end_pfn
, this_end_pfn
);
4230 if (*start_pfn
== -1UL)
4235 * This finds a zone that can be used for ZONE_MOVABLE pages. The
4236 * assumption is made that zones within a node are ordered in monotonic
4237 * increasing memory addresses so that the "highest" populated zone is used
4239 static void __init
find_usable_zone_for_movable(void)
4242 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
4243 if (zone_index
== ZONE_MOVABLE
)
4246 if (arch_zone_highest_possible_pfn
[zone_index
] >
4247 arch_zone_lowest_possible_pfn
[zone_index
])
4251 VM_BUG_ON(zone_index
== -1);
4252 movable_zone
= zone_index
;
4256 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4257 * because it is sized independent of architecture. Unlike the other zones,
4258 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4259 * in each node depending on the size of each node and how evenly kernelcore
4260 * is distributed. This helper function adjusts the zone ranges
4261 * provided by the architecture for a given node by using the end of the
4262 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4263 * zones within a node are in order of monotonic increases memory addresses
4265 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
4266 unsigned long zone_type
,
4267 unsigned long node_start_pfn
,
4268 unsigned long node_end_pfn
,
4269 unsigned long *zone_start_pfn
,
4270 unsigned long *zone_end_pfn
)
4272 /* Only adjust if ZONE_MOVABLE is on this node */
4273 if (zone_movable_pfn
[nid
]) {
4274 /* Size ZONE_MOVABLE */
4275 if (zone_type
== ZONE_MOVABLE
) {
4276 *zone_start_pfn
= zone_movable_pfn
[nid
];
4277 *zone_end_pfn
= min(node_end_pfn
,
4278 arch_zone_highest_possible_pfn
[movable_zone
]);
4280 /* Adjust for ZONE_MOVABLE starting within this range */
4281 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
4282 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
4283 *zone_end_pfn
= zone_movable_pfn
[nid
];
4285 /* Check if this whole range is within ZONE_MOVABLE */
4286 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
4287 *zone_start_pfn
= *zone_end_pfn
;
4292 * Return the number of pages a zone spans in a node, including holes
4293 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4295 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4296 unsigned long zone_type
,
4297 unsigned long *ignored
)
4299 unsigned long node_start_pfn
, node_end_pfn
;
4300 unsigned long zone_start_pfn
, zone_end_pfn
;
4302 /* Get the start and end of the node and zone */
4303 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
4304 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
4305 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
4306 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4307 node_start_pfn
, node_end_pfn
,
4308 &zone_start_pfn
, &zone_end_pfn
);
4310 /* Check that this node has pages within the zone's required range */
4311 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
4314 /* Move the zone boundaries inside the node if necessary */
4315 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
4316 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
4318 /* Return the spanned pages */
4319 return zone_end_pfn
- zone_start_pfn
;
4323 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4324 * then all holes in the requested range will be accounted for.
4326 unsigned long __meminit
__absent_pages_in_range(int nid
,
4327 unsigned long range_start_pfn
,
4328 unsigned long range_end_pfn
)
4330 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
4331 unsigned long start_pfn
, end_pfn
;
4334 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
4335 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
4336 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
4337 nr_absent
-= end_pfn
- start_pfn
;
4343 * absent_pages_in_range - Return number of page frames in holes within a range
4344 * @start_pfn: The start PFN to start searching for holes
4345 * @end_pfn: The end PFN to stop searching for holes
4347 * It returns the number of pages frames in memory holes within a range.
4349 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
4350 unsigned long end_pfn
)
4352 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
4355 /* Return the number of page frames in holes in a zone on a node */
4356 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4357 unsigned long zone_type
,
4358 unsigned long *ignored
)
4360 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
4361 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
4362 unsigned long node_start_pfn
, node_end_pfn
;
4363 unsigned long zone_start_pfn
, zone_end_pfn
;
4365 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
4366 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
4367 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
4369 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4370 node_start_pfn
, node_end_pfn
,
4371 &zone_start_pfn
, &zone_end_pfn
);
4372 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
4375 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4376 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4377 unsigned long zone_type
,
4378 unsigned long *zones_size
)
4380 return zones_size
[zone_type
];
4383 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4384 unsigned long zone_type
,
4385 unsigned long *zholes_size
)
4390 return zholes_size
[zone_type
];
4393 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4395 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
4396 unsigned long *zones_size
, unsigned long *zholes_size
)
4398 unsigned long realtotalpages
, totalpages
= 0;
4401 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4402 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
4404 pgdat
->node_spanned_pages
= totalpages
;
4406 realtotalpages
= totalpages
;
4407 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4409 zone_absent_pages_in_node(pgdat
->node_id
, i
,
4411 pgdat
->node_present_pages
= realtotalpages
;
4412 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
4416 #ifndef CONFIG_SPARSEMEM
4418 * Calculate the size of the zone->blockflags rounded to an unsigned long
4419 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4420 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4421 * round what is now in bits to nearest long in bits, then return it in
4424 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
4426 unsigned long usemapsize
;
4428 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
4429 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
4430 usemapsize
= usemapsize
>> pageblock_order
;
4431 usemapsize
*= NR_PAGEBLOCK_BITS
;
4432 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
4434 return usemapsize
/ 8;
4437 static void __init
setup_usemap(struct pglist_data
*pgdat
,
4439 unsigned long zone_start_pfn
,
4440 unsigned long zonesize
)
4442 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
4443 zone
->pageblock_flags
= NULL
;
4445 zone
->pageblock_flags
= alloc_bootmem_node_nopanic(pgdat
,
4449 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
4450 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
4451 #endif /* CONFIG_SPARSEMEM */
4453 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4455 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4456 void __init
set_pageblock_order(void)
4460 /* Check that pageblock_nr_pages has not already been setup */
4461 if (pageblock_order
)
4464 if (HPAGE_SHIFT
> PAGE_SHIFT
)
4465 order
= HUGETLB_PAGE_ORDER
;
4467 order
= MAX_ORDER
- 1;
4470 * Assume the largest contiguous order of interest is a huge page.
4471 * This value may be variable depending on boot parameters on IA64 and
4474 pageblock_order
= order
;
4476 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4479 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4480 * is unused as pageblock_order is set at compile-time. See
4481 * include/linux/pageblock-flags.h for the values of pageblock_order based on
4484 void __init
set_pageblock_order(void)
4488 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4490 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
4491 unsigned long present_pages
)
4493 unsigned long pages
= spanned_pages
;
4496 * Provide a more accurate estimation if there are holes within
4497 * the zone and SPARSEMEM is in use. If there are holes within the
4498 * zone, each populated memory region may cost us one or two extra
4499 * memmap pages due to alignment because memmap pages for each
4500 * populated regions may not naturally algined on page boundary.
4501 * So the (present_pages >> 4) heuristic is a tradeoff for that.
4503 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
4504 IS_ENABLED(CONFIG_SPARSEMEM
))
4505 pages
= present_pages
;
4507 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
4511 * Set up the zone data structures:
4512 * - mark all pages reserved
4513 * - mark all memory queues empty
4514 * - clear the memory bitmaps
4516 * NOTE: pgdat should get zeroed by caller.
4518 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
,
4519 unsigned long *zones_size
, unsigned long *zholes_size
)
4522 int nid
= pgdat
->node_id
;
4523 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
4526 pgdat_resize_init(pgdat
);
4527 #ifdef CONFIG_NUMA_BALANCING
4528 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
4529 pgdat
->numabalancing_migrate_nr_pages
= 0;
4530 pgdat
->numabalancing_migrate_next_window
= jiffies
;
4532 init_waitqueue_head(&pgdat
->kswapd_wait
);
4533 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
4534 pgdat_page_cgroup_init(pgdat
);
4536 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4537 struct zone
*zone
= pgdat
->node_zones
+ j
;
4538 unsigned long size
, realsize
, freesize
, memmap_pages
;
4540 size
= zone_spanned_pages_in_node(nid
, j
, zones_size
);
4541 realsize
= freesize
= size
- zone_absent_pages_in_node(nid
, j
,
4545 * Adjust freesize so that it accounts for how much memory
4546 * is used by this zone for memmap. This affects the watermark
4547 * and per-cpu initialisations
4549 memmap_pages
= calc_memmap_size(size
, realsize
);
4550 if (freesize
>= memmap_pages
) {
4551 freesize
-= memmap_pages
;
4554 " %s zone: %lu pages used for memmap\n",
4555 zone_names
[j
], memmap_pages
);
4558 " %s zone: %lu pages exceeds freesize %lu\n",
4559 zone_names
[j
], memmap_pages
, freesize
);
4561 /* Account for reserved pages */
4562 if (j
== 0 && freesize
> dma_reserve
) {
4563 freesize
-= dma_reserve
;
4564 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
4565 zone_names
[0], dma_reserve
);
4568 if (!is_highmem_idx(j
))
4569 nr_kernel_pages
+= freesize
;
4570 /* Charge for highmem memmap if there are enough kernel pages */
4571 else if (nr_kernel_pages
> memmap_pages
* 2)
4572 nr_kernel_pages
-= memmap_pages
;
4573 nr_all_pages
+= freesize
;
4575 zone
->spanned_pages
= size
;
4576 zone
->present_pages
= freesize
;
4578 * Set an approximate value for lowmem here, it will be adjusted
4579 * when the bootmem allocator frees pages into the buddy system.
4580 * And all highmem pages will be managed by the buddy system.
4582 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
4585 zone
->min_unmapped_pages
= (freesize
*sysctl_min_unmapped_ratio
)
4587 zone
->min_slab_pages
= (freesize
* sysctl_min_slab_ratio
) / 100;
4589 zone
->name
= zone_names
[j
];
4590 spin_lock_init(&zone
->lock
);
4591 spin_lock_init(&zone
->lru_lock
);
4592 zone_seqlock_init(zone
);
4593 zone
->zone_pgdat
= pgdat
;
4595 zone_pcp_init(zone
);
4596 lruvec_init(&zone
->lruvec
);
4600 set_pageblock_order();
4601 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
4602 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
4603 size
, MEMMAP_EARLY
);
4605 memmap_init(size
, nid
, j
, zone_start_pfn
);
4606 zone_start_pfn
+= size
;
4610 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
4612 /* Skip empty nodes */
4613 if (!pgdat
->node_spanned_pages
)
4616 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4617 /* ia64 gets its own node_mem_map, before this, without bootmem */
4618 if (!pgdat
->node_mem_map
) {
4619 unsigned long size
, start
, end
;
4623 * The zone's endpoints aren't required to be MAX_ORDER
4624 * aligned but the node_mem_map endpoints must be in order
4625 * for the buddy allocator to function correctly.
4627 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
4628 end
= pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
4629 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
4630 size
= (end
- start
) * sizeof(struct page
);
4631 map
= alloc_remap(pgdat
->node_id
, size
);
4633 map
= alloc_bootmem_node_nopanic(pgdat
, size
);
4634 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
4636 #ifndef CONFIG_NEED_MULTIPLE_NODES
4638 * With no DISCONTIG, the global mem_map is just set as node 0's
4640 if (pgdat
== NODE_DATA(0)) {
4641 mem_map
= NODE_DATA(0)->node_mem_map
;
4642 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4643 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
4644 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
4645 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4648 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4651 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
4652 unsigned long node_start_pfn
, unsigned long *zholes_size
)
4654 pg_data_t
*pgdat
= NODE_DATA(nid
);
4656 /* pg_data_t should be reset to zero when it's allocated */
4657 WARN_ON(pgdat
->nr_zones
|| pgdat
->classzone_idx
);
4659 pgdat
->node_id
= nid
;
4660 pgdat
->node_start_pfn
= node_start_pfn
;
4661 init_zone_allows_reclaim(nid
);
4662 calculate_node_totalpages(pgdat
, zones_size
, zholes_size
);
4664 alloc_node_mem_map(pgdat
);
4665 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4666 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
4667 nid
, (unsigned long)pgdat
,
4668 (unsigned long)pgdat
->node_mem_map
);
4671 free_area_init_core(pgdat
, zones_size
, zholes_size
);
4674 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4676 #if MAX_NUMNODES > 1
4678 * Figure out the number of possible node ids.
4680 static void __init
setup_nr_node_ids(void)
4683 unsigned int highest
= 0;
4685 for_each_node_mask(node
, node_possible_map
)
4687 nr_node_ids
= highest
+ 1;
4690 static inline void setup_nr_node_ids(void)
4696 * node_map_pfn_alignment - determine the maximum internode alignment
4698 * This function should be called after node map is populated and sorted.
4699 * It calculates the maximum power of two alignment which can distinguish
4702 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
4703 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
4704 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
4705 * shifted, 1GiB is enough and this function will indicate so.
4707 * This is used to test whether pfn -> nid mapping of the chosen memory
4708 * model has fine enough granularity to avoid incorrect mapping for the
4709 * populated node map.
4711 * Returns the determined alignment in pfn's. 0 if there is no alignment
4712 * requirement (single node).
4714 unsigned long __init
node_map_pfn_alignment(void)
4716 unsigned long accl_mask
= 0, last_end
= 0;
4717 unsigned long start
, end
, mask
;
4721 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
4722 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
4729 * Start with a mask granular enough to pin-point to the
4730 * start pfn and tick off bits one-by-one until it becomes
4731 * too coarse to separate the current node from the last.
4733 mask
= ~((1 << __ffs(start
)) - 1);
4734 while (mask
&& last_end
<= (start
& (mask
<< 1)))
4737 /* accumulate all internode masks */
4741 /* convert mask to number of pages */
4742 return ~accl_mask
+ 1;
4745 /* Find the lowest pfn for a node */
4746 static unsigned long __init
find_min_pfn_for_node(int nid
)
4748 unsigned long min_pfn
= ULONG_MAX
;
4749 unsigned long start_pfn
;
4752 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
4753 min_pfn
= min(min_pfn
, start_pfn
);
4755 if (min_pfn
== ULONG_MAX
) {
4757 "Could not find start_pfn for node %d\n", nid
);
4765 * find_min_pfn_with_active_regions - Find the minimum PFN registered
4767 * It returns the minimum PFN based on information provided via
4768 * add_active_range().
4770 unsigned long __init
find_min_pfn_with_active_regions(void)
4772 return find_min_pfn_for_node(MAX_NUMNODES
);
4776 * early_calculate_totalpages()
4777 * Sum pages in active regions for movable zone.
4778 * Populate N_MEMORY for calculating usable_nodes.
4780 static unsigned long __init
early_calculate_totalpages(void)
4782 unsigned long totalpages
= 0;
4783 unsigned long start_pfn
, end_pfn
;
4786 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
4787 unsigned long pages
= end_pfn
- start_pfn
;
4789 totalpages
+= pages
;
4791 node_set_state(nid
, N_MEMORY
);
4797 * Find the PFN the Movable zone begins in each node. Kernel memory
4798 * is spread evenly between nodes as long as the nodes have enough
4799 * memory. When they don't, some nodes will have more kernelcore than
4802 static void __init
find_zone_movable_pfns_for_nodes(void)
4805 unsigned long usable_startpfn
;
4806 unsigned long kernelcore_node
, kernelcore_remaining
;
4807 /* save the state before borrow the nodemask */
4808 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
4809 unsigned long totalpages
= early_calculate_totalpages();
4810 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
4813 * If movablecore was specified, calculate what size of
4814 * kernelcore that corresponds so that memory usable for
4815 * any allocation type is evenly spread. If both kernelcore
4816 * and movablecore are specified, then the value of kernelcore
4817 * will be used for required_kernelcore if it's greater than
4818 * what movablecore would have allowed.
4820 if (required_movablecore
) {
4821 unsigned long corepages
;
4824 * Round-up so that ZONE_MOVABLE is at least as large as what
4825 * was requested by the user
4827 required_movablecore
=
4828 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
4829 corepages
= totalpages
- required_movablecore
;
4831 required_kernelcore
= max(required_kernelcore
, corepages
);
4834 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
4835 if (!required_kernelcore
)
4838 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
4839 find_usable_zone_for_movable();
4840 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
4843 /* Spread kernelcore memory as evenly as possible throughout nodes */
4844 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4845 for_each_node_state(nid
, N_MEMORY
) {
4846 unsigned long start_pfn
, end_pfn
;
4849 * Recalculate kernelcore_node if the division per node
4850 * now exceeds what is necessary to satisfy the requested
4851 * amount of memory for the kernel
4853 if (required_kernelcore
< kernelcore_node
)
4854 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4857 * As the map is walked, we track how much memory is usable
4858 * by the kernel using kernelcore_remaining. When it is
4859 * 0, the rest of the node is usable by ZONE_MOVABLE
4861 kernelcore_remaining
= kernelcore_node
;
4863 /* Go through each range of PFNs within this node */
4864 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
4865 unsigned long size_pages
;
4867 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
4868 if (start_pfn
>= end_pfn
)
4871 /* Account for what is only usable for kernelcore */
4872 if (start_pfn
< usable_startpfn
) {
4873 unsigned long kernel_pages
;
4874 kernel_pages
= min(end_pfn
, usable_startpfn
)
4877 kernelcore_remaining
-= min(kernel_pages
,
4878 kernelcore_remaining
);
4879 required_kernelcore
-= min(kernel_pages
,
4880 required_kernelcore
);
4882 /* Continue if range is now fully accounted */
4883 if (end_pfn
<= usable_startpfn
) {
4886 * Push zone_movable_pfn to the end so
4887 * that if we have to rebalance
4888 * kernelcore across nodes, we will
4889 * not double account here
4891 zone_movable_pfn
[nid
] = end_pfn
;
4894 start_pfn
= usable_startpfn
;
4898 * The usable PFN range for ZONE_MOVABLE is from
4899 * start_pfn->end_pfn. Calculate size_pages as the
4900 * number of pages used as kernelcore
4902 size_pages
= end_pfn
- start_pfn
;
4903 if (size_pages
> kernelcore_remaining
)
4904 size_pages
= kernelcore_remaining
;
4905 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
4908 * Some kernelcore has been met, update counts and
4909 * break if the kernelcore for this node has been
4912 required_kernelcore
-= min(required_kernelcore
,
4914 kernelcore_remaining
-= size_pages
;
4915 if (!kernelcore_remaining
)
4921 * If there is still required_kernelcore, we do another pass with one
4922 * less node in the count. This will push zone_movable_pfn[nid] further
4923 * along on the nodes that still have memory until kernelcore is
4927 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
4930 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
4931 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
4932 zone_movable_pfn
[nid
] =
4933 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
4936 /* restore the node_state */
4937 node_states
[N_MEMORY
] = saved_node_state
;
4940 /* Any regular or high memory on that node ? */
4941 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
4943 enum zone_type zone_type
;
4945 if (N_MEMORY
== N_NORMAL_MEMORY
)
4948 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
4949 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4950 if (zone
->present_pages
) {
4951 node_set_state(nid
, N_HIGH_MEMORY
);
4952 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
4953 zone_type
<= ZONE_NORMAL
)
4954 node_set_state(nid
, N_NORMAL_MEMORY
);
4961 * free_area_init_nodes - Initialise all pg_data_t and zone data
4962 * @max_zone_pfn: an array of max PFNs for each zone
4964 * This will call free_area_init_node() for each active node in the system.
4965 * Using the page ranges provided by add_active_range(), the size of each
4966 * zone in each node and their holes is calculated. If the maximum PFN
4967 * between two adjacent zones match, it is assumed that the zone is empty.
4968 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
4969 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
4970 * starts where the previous one ended. For example, ZONE_DMA32 starts
4971 * at arch_max_dma_pfn.
4973 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
4975 unsigned long start_pfn
, end_pfn
;
4978 /* Record where the zone boundaries are */
4979 memset(arch_zone_lowest_possible_pfn
, 0,
4980 sizeof(arch_zone_lowest_possible_pfn
));
4981 memset(arch_zone_highest_possible_pfn
, 0,
4982 sizeof(arch_zone_highest_possible_pfn
));
4983 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
4984 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
4985 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
4986 if (i
== ZONE_MOVABLE
)
4988 arch_zone_lowest_possible_pfn
[i
] =
4989 arch_zone_highest_possible_pfn
[i
-1];
4990 arch_zone_highest_possible_pfn
[i
] =
4991 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
4993 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
4994 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
4996 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
4997 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
4998 find_zone_movable_pfns_for_nodes();
5000 /* Print out the zone ranges */
5001 printk("Zone ranges:\n");
5002 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5003 if (i
== ZONE_MOVABLE
)
5005 printk(KERN_CONT
" %-8s ", zone_names
[i
]);
5006 if (arch_zone_lowest_possible_pfn
[i
] ==
5007 arch_zone_highest_possible_pfn
[i
])
5008 printk(KERN_CONT
"empty\n");
5010 printk(KERN_CONT
"[mem %0#10lx-%0#10lx]\n",
5011 arch_zone_lowest_possible_pfn
[i
] << PAGE_SHIFT
,
5012 (arch_zone_highest_possible_pfn
[i
]
5013 << PAGE_SHIFT
) - 1);
5016 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5017 printk("Movable zone start for each node\n");
5018 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
5019 if (zone_movable_pfn
[i
])
5020 printk(" Node %d: %#010lx\n", i
,
5021 zone_movable_pfn
[i
] << PAGE_SHIFT
);
5024 /* Print out the early node map */
5025 printk("Early memory node ranges\n");
5026 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
5027 printk(" node %3d: [mem %#010lx-%#010lx]\n", nid
,
5028 start_pfn
<< PAGE_SHIFT
, (end_pfn
<< PAGE_SHIFT
) - 1);
5030 /* Initialise every node */
5031 mminit_verify_pageflags_layout();
5032 setup_nr_node_ids();
5033 for_each_online_node(nid
) {
5034 pg_data_t
*pgdat
= NODE_DATA(nid
);
5035 free_area_init_node(nid
, NULL
,
5036 find_min_pfn_for_node(nid
), NULL
);
5038 /* Any memory on that node */
5039 if (pgdat
->node_present_pages
)
5040 node_set_state(nid
, N_MEMORY
);
5041 check_for_memory(pgdat
, nid
);
5045 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
5047 unsigned long long coremem
;
5051 coremem
= memparse(p
, &p
);
5052 *core
= coremem
>> PAGE_SHIFT
;
5054 /* Paranoid check that UL is enough for the coremem value */
5055 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
5061 * kernelcore=size sets the amount of memory for use for allocations that
5062 * cannot be reclaimed or migrated.
5064 static int __init
cmdline_parse_kernelcore(char *p
)
5066 return cmdline_parse_core(p
, &required_kernelcore
);
5070 * movablecore=size sets the amount of memory for use for allocations that
5071 * can be reclaimed or migrated.
5073 static int __init
cmdline_parse_movablecore(char *p
)
5075 return cmdline_parse_core(p
, &required_movablecore
);
5078 early_param("kernelcore", cmdline_parse_kernelcore
);
5079 early_param("movablecore", cmdline_parse_movablecore
);
5081 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5084 * set_dma_reserve - set the specified number of pages reserved in the first zone
5085 * @new_dma_reserve: The number of pages to mark reserved
5087 * The per-cpu batchsize and zone watermarks are determined by present_pages.
5088 * In the DMA zone, a significant percentage may be consumed by kernel image
5089 * and other unfreeable allocations which can skew the watermarks badly. This
5090 * function may optionally be used to account for unfreeable pages in the
5091 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
5092 * smaller per-cpu batchsize.
5094 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
5096 dma_reserve
= new_dma_reserve
;
5099 void __init
free_area_init(unsigned long *zones_size
)
5101 free_area_init_node(0, zones_size
,
5102 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
5105 static int page_alloc_cpu_notify(struct notifier_block
*self
,
5106 unsigned long action
, void *hcpu
)
5108 int cpu
= (unsigned long)hcpu
;
5110 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
5111 lru_add_drain_cpu(cpu
);
5115 * Spill the event counters of the dead processor
5116 * into the current processors event counters.
5117 * This artificially elevates the count of the current
5120 vm_events_fold_cpu(cpu
);
5123 * Zero the differential counters of the dead processor
5124 * so that the vm statistics are consistent.
5126 * This is only okay since the processor is dead and cannot
5127 * race with what we are doing.
5129 refresh_cpu_vm_stats(cpu
);
5134 void __init
page_alloc_init(void)
5136 hotcpu_notifier(page_alloc_cpu_notify
, 0);
5140 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
5141 * or min_free_kbytes changes.
5143 static void calculate_totalreserve_pages(void)
5145 struct pglist_data
*pgdat
;
5146 unsigned long reserve_pages
= 0;
5147 enum zone_type i
, j
;
5149 for_each_online_pgdat(pgdat
) {
5150 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5151 struct zone
*zone
= pgdat
->node_zones
+ i
;
5152 unsigned long max
= 0;
5154 /* Find valid and maximum lowmem_reserve in the zone */
5155 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
5156 if (zone
->lowmem_reserve
[j
] > max
)
5157 max
= zone
->lowmem_reserve
[j
];
5160 /* we treat the high watermark as reserved pages. */
5161 max
+= high_wmark_pages(zone
);
5163 if (max
> zone
->present_pages
)
5164 max
= zone
->present_pages
;
5165 reserve_pages
+= max
;
5167 * Lowmem reserves are not available to
5168 * GFP_HIGHUSER page cache allocations and
5169 * kswapd tries to balance zones to their high
5170 * watermark. As a result, neither should be
5171 * regarded as dirtyable memory, to prevent a
5172 * situation where reclaim has to clean pages
5173 * in order to balance the zones.
5175 zone
->dirty_balance_reserve
= max
;
5178 dirty_balance_reserve
= reserve_pages
;
5179 totalreserve_pages
= reserve_pages
;
5183 * setup_per_zone_lowmem_reserve - called whenever
5184 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
5185 * has a correct pages reserved value, so an adequate number of
5186 * pages are left in the zone after a successful __alloc_pages().
5188 static void setup_per_zone_lowmem_reserve(void)
5190 struct pglist_data
*pgdat
;
5191 enum zone_type j
, idx
;
5193 for_each_online_pgdat(pgdat
) {
5194 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5195 struct zone
*zone
= pgdat
->node_zones
+ j
;
5196 unsigned long present_pages
= zone
->present_pages
;
5198 zone
->lowmem_reserve
[j
] = 0;
5202 struct zone
*lower_zone
;
5206 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
5207 sysctl_lowmem_reserve_ratio
[idx
] = 1;
5209 lower_zone
= pgdat
->node_zones
+ idx
;
5210 lower_zone
->lowmem_reserve
[j
] = present_pages
/
5211 sysctl_lowmem_reserve_ratio
[idx
];
5212 present_pages
+= lower_zone
->present_pages
;
5217 /* update totalreserve_pages */
5218 calculate_totalreserve_pages();
5221 static void __setup_per_zone_wmarks(void)
5223 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
5224 unsigned long lowmem_pages
= 0;
5226 unsigned long flags
;
5228 /* Calculate total number of !ZONE_HIGHMEM pages */
5229 for_each_zone(zone
) {
5230 if (!is_highmem(zone
))
5231 lowmem_pages
+= zone
->present_pages
;
5234 for_each_zone(zone
) {
5237 spin_lock_irqsave(&zone
->lock
, flags
);
5238 tmp
= (u64
)pages_min
* zone
->present_pages
;
5239 do_div(tmp
, lowmem_pages
);
5240 if (is_highmem(zone
)) {
5242 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
5243 * need highmem pages, so cap pages_min to a small
5246 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
5247 * deltas controls asynch page reclaim, and so should
5248 * not be capped for highmem.
5252 min_pages
= zone
->present_pages
/ 1024;
5253 if (min_pages
< SWAP_CLUSTER_MAX
)
5254 min_pages
= SWAP_CLUSTER_MAX
;
5255 if (min_pages
> 128)
5257 zone
->watermark
[WMARK_MIN
] = min_pages
;
5260 * If it's a lowmem zone, reserve a number of pages
5261 * proportionate to the zone's size.
5263 zone
->watermark
[WMARK_MIN
] = tmp
;
5266 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + (tmp
>> 2);
5267 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + (tmp
>> 1);
5269 setup_zone_migrate_reserve(zone
);
5270 spin_unlock_irqrestore(&zone
->lock
, flags
);
5273 /* update totalreserve_pages */
5274 calculate_totalreserve_pages();
5278 * setup_per_zone_wmarks - called when min_free_kbytes changes
5279 * or when memory is hot-{added|removed}
5281 * Ensures that the watermark[min,low,high] values for each zone are set
5282 * correctly with respect to min_free_kbytes.
5284 void setup_per_zone_wmarks(void)
5286 mutex_lock(&zonelists_mutex
);
5287 __setup_per_zone_wmarks();
5288 mutex_unlock(&zonelists_mutex
);
5292 * The inactive anon list should be small enough that the VM never has to
5293 * do too much work, but large enough that each inactive page has a chance
5294 * to be referenced again before it is swapped out.
5296 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
5297 * INACTIVE_ANON pages on this zone's LRU, maintained by the
5298 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
5299 * the anonymous pages are kept on the inactive list.
5302 * memory ratio inactive anon
5303 * -------------------------------------
5312 static void __meminit
calculate_zone_inactive_ratio(struct zone
*zone
)
5314 unsigned int gb
, ratio
;
5316 /* Zone size in gigabytes */
5317 gb
= zone
->present_pages
>> (30 - PAGE_SHIFT
);
5319 ratio
= int_sqrt(10 * gb
);
5323 zone
->inactive_ratio
= ratio
;
5326 static void __meminit
setup_per_zone_inactive_ratio(void)
5331 calculate_zone_inactive_ratio(zone
);
5335 * Initialise min_free_kbytes.
5337 * For small machines we want it small (128k min). For large machines
5338 * we want it large (64MB max). But it is not linear, because network
5339 * bandwidth does not increase linearly with machine size. We use
5341 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5342 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
5358 int __meminit
init_per_zone_wmark_min(void)
5360 unsigned long lowmem_kbytes
;
5362 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
5364 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
5365 if (min_free_kbytes
< 128)
5366 min_free_kbytes
= 128;
5367 if (min_free_kbytes
> 65536)
5368 min_free_kbytes
= 65536;
5369 setup_per_zone_wmarks();
5370 refresh_zone_stat_thresholds();
5371 setup_per_zone_lowmem_reserve();
5372 setup_per_zone_inactive_ratio();
5375 module_init(init_per_zone_wmark_min
)
5378 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5379 * that we can call two helper functions whenever min_free_kbytes
5382 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
5383 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5385 proc_dointvec(table
, write
, buffer
, length
, ppos
);
5387 setup_per_zone_wmarks();
5392 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
5393 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5398 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5403 zone
->min_unmapped_pages
= (zone
->present_pages
*
5404 sysctl_min_unmapped_ratio
) / 100;
5408 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
5409 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5414 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5419 zone
->min_slab_pages
= (zone
->present_pages
*
5420 sysctl_min_slab_ratio
) / 100;
5426 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5427 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5428 * whenever sysctl_lowmem_reserve_ratio changes.
5430 * The reserve ratio obviously has absolutely no relation with the
5431 * minimum watermarks. The lowmem reserve ratio can only make sense
5432 * if in function of the boot time zone sizes.
5434 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
5435 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5437 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5438 setup_per_zone_lowmem_reserve();
5443 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5444 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
5445 * can have before it gets flushed back to buddy allocator.
5448 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
5449 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5455 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5456 if (!write
|| (ret
< 0))
5458 for_each_populated_zone(zone
) {
5459 for_each_possible_cpu(cpu
) {
5461 high
= zone
->present_pages
/ percpu_pagelist_fraction
;
5462 setup_pagelist_highmark(
5463 per_cpu_ptr(zone
->pageset
, cpu
), high
);
5469 int hashdist
= HASHDIST_DEFAULT
;
5472 static int __init
set_hashdist(char *str
)
5476 hashdist
= simple_strtoul(str
, &str
, 0);
5479 __setup("hashdist=", set_hashdist
);
5483 * allocate a large system hash table from bootmem
5484 * - it is assumed that the hash table must contain an exact power-of-2
5485 * quantity of entries
5486 * - limit is the number of hash buckets, not the total allocation size
5488 void *__init
alloc_large_system_hash(const char *tablename
,
5489 unsigned long bucketsize
,
5490 unsigned long numentries
,
5493 unsigned int *_hash_shift
,
5494 unsigned int *_hash_mask
,
5495 unsigned long low_limit
,
5496 unsigned long high_limit
)
5498 unsigned long long max
= high_limit
;
5499 unsigned long log2qty
, size
;
5502 /* allow the kernel cmdline to have a say */
5504 /* round applicable memory size up to nearest megabyte */
5505 numentries
= nr_kernel_pages
;
5506 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
5507 numentries
>>= 20 - PAGE_SHIFT
;
5508 numentries
<<= 20 - PAGE_SHIFT
;
5510 /* limit to 1 bucket per 2^scale bytes of low memory */
5511 if (scale
> PAGE_SHIFT
)
5512 numentries
>>= (scale
- PAGE_SHIFT
);
5514 numentries
<<= (PAGE_SHIFT
- scale
);
5516 /* Make sure we've got at least a 0-order allocation.. */
5517 if (unlikely(flags
& HASH_SMALL
)) {
5518 /* Makes no sense without HASH_EARLY */
5519 WARN_ON(!(flags
& HASH_EARLY
));
5520 if (!(numentries
>> *_hash_shift
)) {
5521 numentries
= 1UL << *_hash_shift
;
5522 BUG_ON(!numentries
);
5524 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
5525 numentries
= PAGE_SIZE
/ bucketsize
;
5527 numentries
= roundup_pow_of_two(numentries
);
5529 /* limit allocation size to 1/16 total memory by default */
5531 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
5532 do_div(max
, bucketsize
);
5534 max
= min(max
, 0x80000000ULL
);
5536 if (numentries
< low_limit
)
5537 numentries
= low_limit
;
5538 if (numentries
> max
)
5541 log2qty
= ilog2(numentries
);
5544 size
= bucketsize
<< log2qty
;
5545 if (flags
& HASH_EARLY
)
5546 table
= alloc_bootmem_nopanic(size
);
5548 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
5551 * If bucketsize is not a power-of-two, we may free
5552 * some pages at the end of hash table which
5553 * alloc_pages_exact() automatically does
5555 if (get_order(size
) < MAX_ORDER
) {
5556 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
5557 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
5560 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
5563 panic("Failed to allocate %s hash table\n", tablename
);
5565 printk(KERN_INFO
"%s hash table entries: %ld (order: %d, %lu bytes)\n",
5568 ilog2(size
) - PAGE_SHIFT
,
5572 *_hash_shift
= log2qty
;
5574 *_hash_mask
= (1 << log2qty
) - 1;
5579 /* Return a pointer to the bitmap storing bits affecting a block of pages */
5580 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
5583 #ifdef CONFIG_SPARSEMEM
5584 return __pfn_to_section(pfn
)->pageblock_flags
;
5586 return zone
->pageblock_flags
;
5587 #endif /* CONFIG_SPARSEMEM */
5590 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
5592 #ifdef CONFIG_SPARSEMEM
5593 pfn
&= (PAGES_PER_SECTION
-1);
5594 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5596 pfn
= pfn
- round_down(zone
->zone_start_pfn
, pageblock_nr_pages
);
5597 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5598 #endif /* CONFIG_SPARSEMEM */
5602 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5603 * @page: The page within the block of interest
5604 * @start_bitidx: The first bit of interest to retrieve
5605 * @end_bitidx: The last bit of interest
5606 * returns pageblock_bits flags
5608 unsigned long get_pageblock_flags_group(struct page
*page
,
5609 int start_bitidx
, int end_bitidx
)
5612 unsigned long *bitmap
;
5613 unsigned long pfn
, bitidx
;
5614 unsigned long flags
= 0;
5615 unsigned long value
= 1;
5617 zone
= page_zone(page
);
5618 pfn
= page_to_pfn(page
);
5619 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5620 bitidx
= pfn_to_bitidx(zone
, pfn
);
5622 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5623 if (test_bit(bitidx
+ start_bitidx
, bitmap
))
5630 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5631 * @page: The page within the block of interest
5632 * @start_bitidx: The first bit of interest
5633 * @end_bitidx: The last bit of interest
5634 * @flags: The flags to set
5636 void set_pageblock_flags_group(struct page
*page
, unsigned long flags
,
5637 int start_bitidx
, int end_bitidx
)
5640 unsigned long *bitmap
;
5641 unsigned long pfn
, bitidx
;
5642 unsigned long value
= 1;
5644 zone
= page_zone(page
);
5645 pfn
= page_to_pfn(page
);
5646 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5647 bitidx
= pfn_to_bitidx(zone
, pfn
);
5648 VM_BUG_ON(pfn
< zone
->zone_start_pfn
);
5649 VM_BUG_ON(pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
);
5651 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5653 __set_bit(bitidx
+ start_bitidx
, bitmap
);
5655 __clear_bit(bitidx
+ start_bitidx
, bitmap
);
5659 * This function checks whether pageblock includes unmovable pages or not.
5660 * If @count is not zero, it is okay to include less @count unmovable pages
5662 * PageLRU check wihtout isolation or lru_lock could race so that
5663 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
5664 * expect this function should be exact.
5666 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
5667 bool skip_hwpoisoned_pages
)
5669 unsigned long pfn
, iter
, found
;
5673 * For avoiding noise data, lru_add_drain_all() should be called
5674 * If ZONE_MOVABLE, the zone never contains unmovable pages
5676 if (zone_idx(zone
) == ZONE_MOVABLE
)
5678 mt
= get_pageblock_migratetype(page
);
5679 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
5682 pfn
= page_to_pfn(page
);
5683 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
5684 unsigned long check
= pfn
+ iter
;
5686 if (!pfn_valid_within(check
))
5689 page
= pfn_to_page(check
);
5691 * We can't use page_count without pin a page
5692 * because another CPU can free compound page.
5693 * This check already skips compound tails of THP
5694 * because their page->_count is zero at all time.
5696 if (!atomic_read(&page
->_count
)) {
5697 if (PageBuddy(page
))
5698 iter
+= (1 << page_order(page
)) - 1;
5703 * The HWPoisoned page may be not in buddy system, and
5704 * page_count() is not 0.
5706 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
5712 * If there are RECLAIMABLE pages, we need to check it.
5713 * But now, memory offline itself doesn't call shrink_slab()
5714 * and it still to be fixed.
5717 * If the page is not RAM, page_count()should be 0.
5718 * we don't need more check. This is an _used_ not-movable page.
5720 * The problematic thing here is PG_reserved pages. PG_reserved
5721 * is set to both of a memory hole page and a _used_ kernel
5730 bool is_pageblock_removable_nolock(struct page
*page
)
5736 * We have to be careful here because we are iterating over memory
5737 * sections which are not zone aware so we might end up outside of
5738 * the zone but still within the section.
5739 * We have to take care about the node as well. If the node is offline
5740 * its NODE_DATA will be NULL - see page_zone.
5742 if (!node_online(page_to_nid(page
)))
5745 zone
= page_zone(page
);
5746 pfn
= page_to_pfn(page
);
5747 if (zone
->zone_start_pfn
> pfn
||
5748 zone
->zone_start_pfn
+ zone
->spanned_pages
<= pfn
)
5751 return !has_unmovable_pages(zone
, page
, 0, true);
5756 static unsigned long pfn_max_align_down(unsigned long pfn
)
5758 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
5759 pageblock_nr_pages
) - 1);
5762 static unsigned long pfn_max_align_up(unsigned long pfn
)
5764 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
5765 pageblock_nr_pages
));
5768 /* [start, end) must belong to a single zone. */
5769 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
5770 unsigned long start
, unsigned long end
)
5772 /* This function is based on compact_zone() from compaction.c. */
5773 unsigned long nr_reclaimed
;
5774 unsigned long pfn
= start
;
5775 unsigned int tries
= 0;
5780 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
5781 if (fatal_signal_pending(current
)) {
5786 if (list_empty(&cc
->migratepages
)) {
5787 cc
->nr_migratepages
= 0;
5788 pfn
= isolate_migratepages_range(cc
->zone
, cc
,
5795 } else if (++tries
== 5) {
5796 ret
= ret
< 0 ? ret
: -EBUSY
;
5800 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
5802 cc
->nr_migratepages
-= nr_reclaimed
;
5804 ret
= migrate_pages(&cc
->migratepages
,
5805 alloc_migrate_target
,
5806 0, false, MIGRATE_SYNC
,
5810 putback_movable_pages(&cc
->migratepages
);
5811 return ret
> 0 ? 0 : ret
;
5815 * alloc_contig_range() -- tries to allocate given range of pages
5816 * @start: start PFN to allocate
5817 * @end: one-past-the-last PFN to allocate
5818 * @migratetype: migratetype of the underlaying pageblocks (either
5819 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
5820 * in range must have the same migratetype and it must
5821 * be either of the two.
5823 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
5824 * aligned, however it's the caller's responsibility to guarantee that
5825 * we are the only thread that changes migrate type of pageblocks the
5828 * The PFN range must belong to a single zone.
5830 * Returns zero on success or negative error code. On success all
5831 * pages which PFN is in [start, end) are allocated for the caller and
5832 * need to be freed with free_contig_range().
5834 int alloc_contig_range(unsigned long start
, unsigned long end
,
5835 unsigned migratetype
)
5837 unsigned long outer_start
, outer_end
;
5840 struct compact_control cc
= {
5841 .nr_migratepages
= 0,
5843 .zone
= page_zone(pfn_to_page(start
)),
5845 .ignore_skip_hint
= true,
5847 INIT_LIST_HEAD(&cc
.migratepages
);
5850 * What we do here is we mark all pageblocks in range as
5851 * MIGRATE_ISOLATE. Because pageblock and max order pages may
5852 * have different sizes, and due to the way page allocator
5853 * work, we align the range to biggest of the two pages so
5854 * that page allocator won't try to merge buddies from
5855 * different pageblocks and change MIGRATE_ISOLATE to some
5856 * other migration type.
5858 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
5859 * migrate the pages from an unaligned range (ie. pages that
5860 * we are interested in). This will put all the pages in
5861 * range back to page allocator as MIGRATE_ISOLATE.
5863 * When this is done, we take the pages in range from page
5864 * allocator removing them from the buddy system. This way
5865 * page allocator will never consider using them.
5867 * This lets us mark the pageblocks back as
5868 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
5869 * aligned range but not in the unaligned, original range are
5870 * put back to page allocator so that buddy can use them.
5873 ret
= start_isolate_page_range(pfn_max_align_down(start
),
5874 pfn_max_align_up(end
), migratetype
,
5879 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
5884 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
5885 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
5886 * more, all pages in [start, end) are free in page allocator.
5887 * What we are going to do is to allocate all pages from
5888 * [start, end) (that is remove them from page allocator).
5890 * The only problem is that pages at the beginning and at the
5891 * end of interesting range may be not aligned with pages that
5892 * page allocator holds, ie. they can be part of higher order
5893 * pages. Because of this, we reserve the bigger range and
5894 * once this is done free the pages we are not interested in.
5896 * We don't have to hold zone->lock here because the pages are
5897 * isolated thus they won't get removed from buddy.
5900 lru_add_drain_all();
5904 outer_start
= start
;
5905 while (!PageBuddy(pfn_to_page(outer_start
))) {
5906 if (++order
>= MAX_ORDER
) {
5910 outer_start
&= ~0UL << order
;
5913 /* Make sure the range is really isolated. */
5914 if (test_pages_isolated(outer_start
, end
, false)) {
5915 pr_warn("alloc_contig_range test_pages_isolated(%lx, %lx) failed\n",
5922 /* Grab isolated pages from freelists. */
5923 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
5929 /* Free head and tail (if any) */
5930 if (start
!= outer_start
)
5931 free_contig_range(outer_start
, start
- outer_start
);
5932 if (end
!= outer_end
)
5933 free_contig_range(end
, outer_end
- end
);
5936 undo_isolate_page_range(pfn_max_align_down(start
),
5937 pfn_max_align_up(end
), migratetype
);
5941 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
5943 unsigned int count
= 0;
5945 for (; nr_pages
--; pfn
++) {
5946 struct page
*page
= pfn_to_page(pfn
);
5948 count
+= page_count(page
) != 1;
5951 WARN(count
!= 0, "%d pages are still in use!\n", count
);
5955 #ifdef CONFIG_MEMORY_HOTPLUG
5956 static int __meminit
__zone_pcp_update(void *data
)
5958 struct zone
*zone
= data
;
5960 unsigned long batch
= zone_batchsize(zone
), flags
;
5962 for_each_possible_cpu(cpu
) {
5963 struct per_cpu_pageset
*pset
;
5964 struct per_cpu_pages
*pcp
;
5966 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
5969 local_irq_save(flags
);
5971 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
5972 drain_zonestat(zone
, pset
);
5973 setup_pageset(pset
, batch
);
5974 local_irq_restore(flags
);
5979 void __meminit
zone_pcp_update(struct zone
*zone
)
5981 stop_machine(__zone_pcp_update
, zone
, NULL
);
5985 void zone_pcp_reset(struct zone
*zone
)
5987 unsigned long flags
;
5989 struct per_cpu_pageset
*pset
;
5991 /* avoid races with drain_pages() */
5992 local_irq_save(flags
);
5993 if (zone
->pageset
!= &boot_pageset
) {
5994 for_each_online_cpu(cpu
) {
5995 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
5996 drain_zonestat(zone
, pset
);
5998 free_percpu(zone
->pageset
);
5999 zone
->pageset
= &boot_pageset
;
6001 local_irq_restore(flags
);
6004 #ifdef CONFIG_MEMORY_HOTREMOVE
6006 * All pages in the range must be isolated before calling this.
6009 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
6015 unsigned long flags
;
6016 /* find the first valid pfn */
6017 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
6022 zone
= page_zone(pfn_to_page(pfn
));
6023 spin_lock_irqsave(&zone
->lock
, flags
);
6025 while (pfn
< end_pfn
) {
6026 if (!pfn_valid(pfn
)) {
6030 page
= pfn_to_page(pfn
);
6032 * The HWPoisoned page may be not in buddy system, and
6033 * page_count() is not 0.
6035 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
6037 SetPageReserved(page
);
6041 BUG_ON(page_count(page
));
6042 BUG_ON(!PageBuddy(page
));
6043 order
= page_order(page
);
6044 #ifdef CONFIG_DEBUG_VM
6045 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
6046 pfn
, 1 << order
, end_pfn
);
6048 list_del(&page
->lru
);
6049 rmv_page_order(page
);
6050 zone
->free_area
[order
].nr_free
--;
6051 for (i
= 0; i
< (1 << order
); i
++)
6052 SetPageReserved((page
+i
));
6053 pfn
+= (1 << order
);
6055 spin_unlock_irqrestore(&zone
->lock
, flags
);
6059 #ifdef CONFIG_MEMORY_FAILURE
6060 bool is_free_buddy_page(struct page
*page
)
6062 struct zone
*zone
= page_zone(page
);
6063 unsigned long pfn
= page_to_pfn(page
);
6064 unsigned long flags
;
6067 spin_lock_irqsave(&zone
->lock
, flags
);
6068 for (order
= 0; order
< MAX_ORDER
; order
++) {
6069 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
6071 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
6074 spin_unlock_irqrestore(&zone
->lock
, flags
);
6076 return order
< MAX_ORDER
;
6080 static const struct trace_print_flags pageflag_names
[] = {
6081 {1UL << PG_locked
, "locked" },
6082 {1UL << PG_error
, "error" },
6083 {1UL << PG_referenced
, "referenced" },
6084 {1UL << PG_uptodate
, "uptodate" },
6085 {1UL << PG_dirty
, "dirty" },
6086 {1UL << PG_lru
, "lru" },
6087 {1UL << PG_active
, "active" },
6088 {1UL << PG_slab
, "slab" },
6089 {1UL << PG_owner_priv_1
, "owner_priv_1" },
6090 {1UL << PG_arch_1
, "arch_1" },
6091 {1UL << PG_reserved
, "reserved" },
6092 {1UL << PG_private
, "private" },
6093 {1UL << PG_private_2
, "private_2" },
6094 {1UL << PG_writeback
, "writeback" },
6095 #ifdef CONFIG_PAGEFLAGS_EXTENDED
6096 {1UL << PG_head
, "head" },
6097 {1UL << PG_tail
, "tail" },
6099 {1UL << PG_compound
, "compound" },
6101 {1UL << PG_swapcache
, "swapcache" },
6102 {1UL << PG_mappedtodisk
, "mappedtodisk" },
6103 {1UL << PG_reclaim
, "reclaim" },
6104 {1UL << PG_swapbacked
, "swapbacked" },
6105 {1UL << PG_unevictable
, "unevictable" },
6107 {1UL << PG_mlocked
, "mlocked" },
6109 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
6110 {1UL << PG_uncached
, "uncached" },
6112 #ifdef CONFIG_MEMORY_FAILURE
6113 {1UL << PG_hwpoison
, "hwpoison" },
6115 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6116 {1UL << PG_compound_lock
, "compound_lock" },
6120 static void dump_page_flags(unsigned long flags
)
6122 const char *delim
= "";
6126 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names
) != __NR_PAGEFLAGS
);
6128 printk(KERN_ALERT
"page flags: %#lx(", flags
);
6130 /* remove zone id */
6131 flags
&= (1UL << NR_PAGEFLAGS
) - 1;
6133 for (i
= 0; i
< ARRAY_SIZE(pageflag_names
) && flags
; i
++) {
6135 mask
= pageflag_names
[i
].mask
;
6136 if ((flags
& mask
) != mask
)
6140 printk("%s%s", delim
, pageflag_names
[i
].name
);
6144 /* check for left over flags */
6146 printk("%s%#lx", delim
, flags
);
6151 void dump_page(struct page
*page
)
6154 "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
6155 page
, atomic_read(&page
->_count
), page_mapcount(page
),
6156 page
->mapping
, page
->index
);
6157 dump_page_flags(page
->flags
);
6158 mem_cgroup_print_bad_page(page
);