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/hugetlb.h>
62 #include <linux/sched/rt.h>
64 #include <asm/tlbflush.h>
65 #include <asm/div64.h>
68 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
69 DEFINE_PER_CPU(int, numa_node
);
70 EXPORT_PER_CPU_SYMBOL(numa_node
);
73 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
75 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
76 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
77 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
78 * defined in <linux/topology.h>.
80 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
81 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
85 * Array of node states.
87 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
88 [N_POSSIBLE
] = NODE_MASK_ALL
,
89 [N_ONLINE
] = { { [0] = 1UL } },
91 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
93 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
95 #ifdef CONFIG_MOVABLE_NODE
96 [N_MEMORY
] = { { [0] = 1UL } },
98 [N_CPU
] = { { [0] = 1UL } },
101 EXPORT_SYMBOL(node_states
);
103 unsigned long totalram_pages __read_mostly
;
104 unsigned long totalreserve_pages __read_mostly
;
106 * When calculating the number of globally allowed dirty pages, there
107 * is a certain number of per-zone reserves that should not be
108 * considered dirtyable memory. This is the sum of those reserves
109 * over all existing zones that contribute dirtyable memory.
111 unsigned long dirty_balance_reserve __read_mostly
;
113 int percpu_pagelist_fraction
;
114 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
116 #ifdef CONFIG_PM_SLEEP
118 * The following functions are used by the suspend/hibernate code to temporarily
119 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
120 * while devices are suspended. To avoid races with the suspend/hibernate code,
121 * they should always be called with pm_mutex held (gfp_allowed_mask also should
122 * only be modified with pm_mutex held, unless the suspend/hibernate code is
123 * guaranteed not to run in parallel with that modification).
126 static gfp_t saved_gfp_mask
;
128 void pm_restore_gfp_mask(void)
130 WARN_ON(!mutex_is_locked(&pm_mutex
));
131 if (saved_gfp_mask
) {
132 gfp_allowed_mask
= saved_gfp_mask
;
137 void pm_restrict_gfp_mask(void)
139 WARN_ON(!mutex_is_locked(&pm_mutex
));
140 WARN_ON(saved_gfp_mask
);
141 saved_gfp_mask
= gfp_allowed_mask
;
142 gfp_allowed_mask
&= ~GFP_IOFS
;
145 bool pm_suspended_storage(void)
147 if ((gfp_allowed_mask
& GFP_IOFS
) == GFP_IOFS
)
151 #endif /* CONFIG_PM_SLEEP */
153 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
154 int pageblock_order __read_mostly
;
157 static void __free_pages_ok(struct page
*page
, unsigned int order
);
160 * results with 256, 32 in the lowmem_reserve sysctl:
161 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
162 * 1G machine -> (16M dma, 784M normal, 224M high)
163 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
164 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
165 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
167 * TBD: should special case ZONE_DMA32 machines here - in those we normally
168 * don't need any ZONE_NORMAL reservation
170 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
171 #ifdef CONFIG_ZONE_DMA
174 #ifdef CONFIG_ZONE_DMA32
177 #ifdef CONFIG_HIGHMEM
183 EXPORT_SYMBOL(totalram_pages
);
185 static char * const zone_names
[MAX_NR_ZONES
] = {
186 #ifdef CONFIG_ZONE_DMA
189 #ifdef CONFIG_ZONE_DMA32
193 #ifdef CONFIG_HIGHMEM
199 int min_free_kbytes
= 1024;
201 static unsigned long __meminitdata nr_kernel_pages
;
202 static unsigned long __meminitdata nr_all_pages
;
203 static unsigned long __meminitdata dma_reserve
;
205 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
206 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
207 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
208 static unsigned long __initdata required_kernelcore
;
209 static unsigned long __initdata required_movablecore
;
210 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
212 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
214 EXPORT_SYMBOL(movable_zone
);
215 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
218 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
219 int nr_online_nodes __read_mostly
= 1;
220 EXPORT_SYMBOL(nr_node_ids
);
221 EXPORT_SYMBOL(nr_online_nodes
);
224 int page_group_by_mobility_disabled __read_mostly
;
226 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
229 if (unlikely(page_group_by_mobility_disabled
))
230 migratetype
= MIGRATE_UNMOVABLE
;
232 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
233 PB_migrate
, PB_migrate_end
);
236 bool oom_killer_disabled __read_mostly
;
238 #ifdef CONFIG_DEBUG_VM
239 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
243 unsigned long pfn
= page_to_pfn(page
);
244 unsigned long sp
, start_pfn
;
247 seq
= zone_span_seqbegin(zone
);
248 start_pfn
= zone
->zone_start_pfn
;
249 sp
= zone
->spanned_pages
;
250 if (!zone_spans_pfn(zone
, pfn
))
252 } while (zone_span_seqretry(zone
, seq
));
255 pr_err("page %lu outside zone [ %lu - %lu ]\n",
256 pfn
, start_pfn
, start_pfn
+ sp
);
261 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
263 if (!pfn_valid_within(page_to_pfn(page
)))
265 if (zone
!= page_zone(page
))
271 * Temporary debugging check for pages not lying within a given zone.
273 static int bad_range(struct zone
*zone
, struct page
*page
)
275 if (page_outside_zone_boundaries(zone
, page
))
277 if (!page_is_consistent(zone
, page
))
283 static inline int bad_range(struct zone
*zone
, struct page
*page
)
289 static void bad_page(struct page
*page
)
291 static unsigned long resume
;
292 static unsigned long nr_shown
;
293 static unsigned long nr_unshown
;
295 /* Don't complain about poisoned pages */
296 if (PageHWPoison(page
)) {
297 page_mapcount_reset(page
); /* remove PageBuddy */
302 * Allow a burst of 60 reports, then keep quiet for that minute;
303 * or allow a steady drip of one report per second.
305 if (nr_shown
== 60) {
306 if (time_before(jiffies
, resume
)) {
312 "BUG: Bad page state: %lu messages suppressed\n",
319 resume
= jiffies
+ 60 * HZ
;
321 printk(KERN_ALERT
"BUG: Bad page state in process %s pfn:%05lx\n",
322 current
->comm
, page_to_pfn(page
));
328 /* Leave bad fields for debug, except PageBuddy could make trouble */
329 page_mapcount_reset(page
); /* remove PageBuddy */
330 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
334 * Higher-order pages are called "compound pages". They are structured thusly:
336 * The first PAGE_SIZE page is called the "head page".
338 * The remaining PAGE_SIZE pages are called "tail pages".
340 * All pages have PG_compound set. All tail pages have their ->first_page
341 * pointing at the head page.
343 * The first tail page's ->lru.next holds the address of the compound page's
344 * put_page() function. Its ->lru.prev holds the order of allocation.
345 * This usage means that zero-order pages may not be compound.
348 static void free_compound_page(struct page
*page
)
350 __free_pages_ok(page
, compound_order(page
));
353 void prep_compound_page(struct page
*page
, unsigned long order
)
356 int nr_pages
= 1 << order
;
358 set_compound_page_dtor(page
, free_compound_page
);
359 set_compound_order(page
, order
);
361 for (i
= 1; i
< nr_pages
; i
++) {
362 struct page
*p
= page
+ i
;
364 set_page_count(p
, 0);
365 p
->first_page
= page
;
369 /* update __split_huge_page_refcount if you change this function */
370 static int destroy_compound_page(struct page
*page
, unsigned long order
)
373 int nr_pages
= 1 << order
;
376 if (unlikely(compound_order(page
) != order
)) {
381 __ClearPageHead(page
);
383 for (i
= 1; i
< nr_pages
; i
++) {
384 struct page
*p
= page
+ i
;
386 if (unlikely(!PageTail(p
) || (p
->first_page
!= page
))) {
396 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
401 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
402 * and __GFP_HIGHMEM from hard or soft interrupt context.
404 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
405 for (i
= 0; i
< (1 << order
); i
++)
406 clear_highpage(page
+ i
);
409 #ifdef CONFIG_DEBUG_PAGEALLOC
410 unsigned int _debug_guardpage_minorder
;
412 static int __init
debug_guardpage_minorder_setup(char *buf
)
416 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
417 printk(KERN_ERR
"Bad debug_guardpage_minorder value\n");
420 _debug_guardpage_minorder
= res
;
421 printk(KERN_INFO
"Setting debug_guardpage_minorder to %lu\n", res
);
424 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
426 static inline void set_page_guard_flag(struct page
*page
)
428 __set_bit(PAGE_DEBUG_FLAG_GUARD
, &page
->debug_flags
);
431 static inline void clear_page_guard_flag(struct page
*page
)
433 __clear_bit(PAGE_DEBUG_FLAG_GUARD
, &page
->debug_flags
);
436 static inline void set_page_guard_flag(struct page
*page
) { }
437 static inline void clear_page_guard_flag(struct page
*page
) { }
440 static inline void set_page_order(struct page
*page
, int order
)
442 set_page_private(page
, order
);
443 __SetPageBuddy(page
);
446 static inline void rmv_page_order(struct page
*page
)
448 __ClearPageBuddy(page
);
449 set_page_private(page
, 0);
453 * Locate the struct page for both the matching buddy in our
454 * pair (buddy1) and the combined O(n+1) page they form (page).
456 * 1) Any buddy B1 will have an order O twin B2 which satisfies
457 * the following equation:
459 * For example, if the starting buddy (buddy2) is #8 its order
461 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
463 * 2) Any buddy B will have an order O+1 parent P which
464 * satisfies the following equation:
467 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
469 static inline unsigned long
470 __find_buddy_index(unsigned long page_idx
, unsigned int order
)
472 return page_idx
^ (1 << order
);
476 * This function checks whether a page is free && is the buddy
477 * we can do coalesce a page and its buddy if
478 * (a) the buddy is not in a hole &&
479 * (b) the buddy is in the buddy system &&
480 * (c) a page and its buddy have the same order &&
481 * (d) a page and its buddy are in the same zone.
483 * For recording whether a page is in the buddy system, we set ->_mapcount -2.
484 * Setting, clearing, and testing _mapcount -2 is serialized by zone->lock.
486 * For recording page's order, we use page_private(page).
488 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
491 if (!pfn_valid_within(page_to_pfn(buddy
)))
494 if (page_zone_id(page
) != page_zone_id(buddy
))
497 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
498 VM_BUG_ON(page_count(buddy
) != 0);
502 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
503 VM_BUG_ON(page_count(buddy
) != 0);
510 * Freeing function for a buddy system allocator.
512 * The concept of a buddy system is to maintain direct-mapped table
513 * (containing bit values) for memory blocks of various "orders".
514 * The bottom level table contains the map for the smallest allocatable
515 * units of memory (here, pages), and each level above it describes
516 * pairs of units from the levels below, hence, "buddies".
517 * At a high level, all that happens here is marking the table entry
518 * at the bottom level available, and propagating the changes upward
519 * as necessary, plus some accounting needed to play nicely with other
520 * parts of the VM system.
521 * At each level, we keep a list of pages, which are heads of continuous
522 * free pages of length of (1 << order) and marked with _mapcount -2. Page's
523 * order is recorded in page_private(page) field.
524 * So when we are allocating or freeing one, we can derive the state of the
525 * other. That is, if we allocate a small block, and both were
526 * free, the remainder of the region must be split into blocks.
527 * If a block is freed, and its buddy is also free, then this
528 * triggers coalescing into a block of larger size.
533 static inline void __free_one_page(struct page
*page
,
534 struct zone
*zone
, unsigned int order
,
537 unsigned long page_idx
;
538 unsigned long combined_idx
;
539 unsigned long uninitialized_var(buddy_idx
);
542 VM_BUG_ON(!zone_is_initialized(zone
));
544 if (unlikely(PageCompound(page
)))
545 if (unlikely(destroy_compound_page(page
, order
)))
548 VM_BUG_ON(migratetype
== -1);
550 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
552 VM_BUG_ON(page_idx
& ((1 << order
) - 1));
553 VM_BUG_ON(bad_range(zone
, page
));
555 while (order
< MAX_ORDER
-1) {
556 buddy_idx
= __find_buddy_index(page_idx
, order
);
557 buddy
= page
+ (buddy_idx
- page_idx
);
558 if (!page_is_buddy(page
, buddy
, order
))
561 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
562 * merge with it and move up one order.
564 if (page_is_guard(buddy
)) {
565 clear_page_guard_flag(buddy
);
566 set_page_private(page
, 0);
567 __mod_zone_freepage_state(zone
, 1 << order
,
570 list_del(&buddy
->lru
);
571 zone
->free_area
[order
].nr_free
--;
572 rmv_page_order(buddy
);
574 combined_idx
= buddy_idx
& page_idx
;
575 page
= page
+ (combined_idx
- page_idx
);
576 page_idx
= combined_idx
;
579 set_page_order(page
, order
);
582 * If this is not the largest possible page, check if the buddy
583 * of the next-highest order is free. If it is, it's possible
584 * that pages are being freed that will coalesce soon. In case,
585 * that is happening, add the free page to the tail of the list
586 * so it's less likely to be used soon and more likely to be merged
587 * as a higher order page
589 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
590 struct page
*higher_page
, *higher_buddy
;
591 combined_idx
= buddy_idx
& page_idx
;
592 higher_page
= page
+ (combined_idx
- page_idx
);
593 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
594 higher_buddy
= higher_page
+ (buddy_idx
- combined_idx
);
595 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
596 list_add_tail(&page
->lru
,
597 &zone
->free_area
[order
].free_list
[migratetype
]);
602 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
604 zone
->free_area
[order
].nr_free
++;
607 static inline int free_pages_check(struct page
*page
)
609 if (unlikely(page_mapcount(page
) |
610 (page
->mapping
!= NULL
) |
611 (atomic_read(&page
->_count
) != 0) |
612 (page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
) |
613 (mem_cgroup_bad_page_check(page
)))) {
617 page_nid_reset_last(page
);
618 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
619 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
624 * Frees a number of pages from the PCP lists
625 * Assumes all pages on list are in same zone, and of same order.
626 * count is the number of pages to free.
628 * If the zone was previously in an "all pages pinned" state then look to
629 * see if this freeing clears that state.
631 * And clear the zone's pages_scanned counter, to hold off the "all pages are
632 * pinned" detection logic.
634 static void free_pcppages_bulk(struct zone
*zone
, int count
,
635 struct per_cpu_pages
*pcp
)
641 spin_lock(&zone
->lock
);
642 zone
->all_unreclaimable
= 0;
643 zone
->pages_scanned
= 0;
647 struct list_head
*list
;
650 * Remove pages from lists in a round-robin fashion. A
651 * batch_free count is maintained that is incremented when an
652 * empty list is encountered. This is so more pages are freed
653 * off fuller lists instead of spinning excessively around empty
658 if (++migratetype
== MIGRATE_PCPTYPES
)
660 list
= &pcp
->lists
[migratetype
];
661 } while (list_empty(list
));
663 /* This is the only non-empty list. Free them all. */
664 if (batch_free
== MIGRATE_PCPTYPES
)
665 batch_free
= to_free
;
668 int mt
; /* migratetype of the to-be-freed page */
670 page
= list_entry(list
->prev
, struct page
, lru
);
671 /* must delete as __free_one_page list manipulates */
672 list_del(&page
->lru
);
673 mt
= get_freepage_migratetype(page
);
674 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
675 __free_one_page(page
, zone
, 0, mt
);
676 trace_mm_page_pcpu_drain(page
, 0, mt
);
677 if (likely(!is_migrate_isolate_page(page
))) {
678 __mod_zone_page_state(zone
, NR_FREE_PAGES
, 1);
679 if (is_migrate_cma(mt
))
680 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
, 1);
682 } while (--to_free
&& --batch_free
&& !list_empty(list
));
684 spin_unlock(&zone
->lock
);
687 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
,
690 spin_lock(&zone
->lock
);
691 zone
->all_unreclaimable
= 0;
692 zone
->pages_scanned
= 0;
694 __free_one_page(page
, zone
, order
, migratetype
);
695 if (unlikely(!is_migrate_isolate(migratetype
)))
696 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
697 spin_unlock(&zone
->lock
);
700 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
705 trace_mm_page_free(page
, order
);
706 kmemcheck_free_shadow(page
, order
);
709 page
->mapping
= NULL
;
710 for (i
= 0; i
< (1 << order
); i
++)
711 bad
+= free_pages_check(page
+ i
);
715 if (!PageHighMem(page
)) {
716 debug_check_no_locks_freed(page_address(page
),PAGE_SIZE
<<order
);
717 debug_check_no_obj_freed(page_address(page
),
720 arch_free_page(page
, order
);
721 kernel_map_pages(page
, 1 << order
, 0);
726 static void __free_pages_ok(struct page
*page
, unsigned int order
)
731 if (!free_pages_prepare(page
, order
))
734 local_irq_save(flags
);
735 __count_vm_events(PGFREE
, 1 << order
);
736 migratetype
= get_pageblock_migratetype(page
);
737 set_freepage_migratetype(page
, migratetype
);
738 free_one_page(page_zone(page
), page
, order
, migratetype
);
739 local_irq_restore(flags
);
743 * Read access to zone->managed_pages is safe because it's unsigned long,
744 * but we still need to serialize writers. Currently all callers of
745 * __free_pages_bootmem() except put_page_bootmem() should only be used
746 * at boot time. So for shorter boot time, we shift the burden to
747 * put_page_bootmem() to serialize writers.
749 void __meminit
__free_pages_bootmem(struct page
*page
, unsigned int order
)
751 unsigned int nr_pages
= 1 << order
;
755 for (loop
= 0; loop
< nr_pages
; loop
++) {
756 struct page
*p
= &page
[loop
];
758 if (loop
+ 1 < nr_pages
)
760 __ClearPageReserved(p
);
761 set_page_count(p
, 0);
764 page_zone(page
)->managed_pages
+= 1 << order
;
765 set_page_refcounted(page
);
766 __free_pages(page
, order
);
770 /* Free whole pageblock and set it's migration type to MIGRATE_CMA. */
771 void __init
init_cma_reserved_pageblock(struct page
*page
)
773 unsigned i
= pageblock_nr_pages
;
774 struct page
*p
= page
;
777 __ClearPageReserved(p
);
778 set_page_count(p
, 0);
781 set_page_refcounted(page
);
782 set_pageblock_migratetype(page
, MIGRATE_CMA
);
783 __free_pages(page
, pageblock_order
);
784 totalram_pages
+= pageblock_nr_pages
;
785 #ifdef CONFIG_HIGHMEM
786 if (PageHighMem(page
))
787 totalhigh_pages
+= pageblock_nr_pages
;
793 * The order of subdivision here is critical for the IO subsystem.
794 * Please do not alter this order without good reasons and regression
795 * testing. Specifically, as large blocks of memory are subdivided,
796 * the order in which smaller blocks are delivered depends on the order
797 * they're subdivided in this function. This is the primary factor
798 * influencing the order in which pages are delivered to the IO
799 * subsystem according to empirical testing, and this is also justified
800 * by considering the behavior of a buddy system containing a single
801 * large block of memory acted on by a series of small allocations.
802 * This behavior is a critical factor in sglist merging's success.
806 static inline void expand(struct zone
*zone
, struct page
*page
,
807 int low
, int high
, struct free_area
*area
,
810 unsigned long size
= 1 << high
;
816 VM_BUG_ON(bad_range(zone
, &page
[size
]));
818 #ifdef CONFIG_DEBUG_PAGEALLOC
819 if (high
< debug_guardpage_minorder()) {
821 * Mark as guard pages (or page), that will allow to
822 * merge back to allocator when buddy will be freed.
823 * Corresponding page table entries will not be touched,
824 * pages will stay not present in virtual address space
826 INIT_LIST_HEAD(&page
[size
].lru
);
827 set_page_guard_flag(&page
[size
]);
828 set_page_private(&page
[size
], high
);
829 /* Guard pages are not available for any usage */
830 __mod_zone_freepage_state(zone
, -(1 << high
),
835 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
837 set_page_order(&page
[size
], high
);
842 * This page is about to be returned from the page allocator
844 static inline int check_new_page(struct page
*page
)
846 if (unlikely(page_mapcount(page
) |
847 (page
->mapping
!= NULL
) |
848 (atomic_read(&page
->_count
) != 0) |
849 (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
) |
850 (mem_cgroup_bad_page_check(page
)))) {
857 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
861 for (i
= 0; i
< (1 << order
); i
++) {
862 struct page
*p
= page
+ i
;
863 if (unlikely(check_new_page(p
)))
867 set_page_private(page
, 0);
868 set_page_refcounted(page
);
870 arch_alloc_page(page
, order
);
871 kernel_map_pages(page
, 1 << order
, 1);
873 if (gfp_flags
& __GFP_ZERO
)
874 prep_zero_page(page
, order
, gfp_flags
);
876 if (order
&& (gfp_flags
& __GFP_COMP
))
877 prep_compound_page(page
, order
);
883 * Go through the free lists for the given migratetype and remove
884 * the smallest available page from the freelists
887 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
890 unsigned int current_order
;
891 struct free_area
* area
;
894 /* Find a page of the appropriate size in the preferred list */
895 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
896 area
= &(zone
->free_area
[current_order
]);
897 if (list_empty(&area
->free_list
[migratetype
]))
900 page
= list_entry(area
->free_list
[migratetype
].next
,
902 list_del(&page
->lru
);
903 rmv_page_order(page
);
905 expand(zone
, page
, order
, current_order
, area
, migratetype
);
914 * This array describes the order lists are fallen back to when
915 * the free lists for the desirable migrate type are depleted
917 static int fallbacks
[MIGRATE_TYPES
][4] = {
918 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
919 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
921 [MIGRATE_MOVABLE
] = { MIGRATE_CMA
, MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
922 [MIGRATE_CMA
] = { MIGRATE_RESERVE
}, /* Never used */
924 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
926 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
}, /* Never used */
927 #ifdef CONFIG_MEMORY_ISOLATION
928 [MIGRATE_ISOLATE
] = { MIGRATE_RESERVE
}, /* Never used */
933 * Move the free pages in a range to the free lists of the requested type.
934 * Note that start_page and end_pages are not aligned on a pageblock
935 * boundary. If alignment is required, use move_freepages_block()
937 int move_freepages(struct zone
*zone
,
938 struct page
*start_page
, struct page
*end_page
,
945 #ifndef CONFIG_HOLES_IN_ZONE
947 * page_zone is not safe to call in this context when
948 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
949 * anyway as we check zone boundaries in move_freepages_block().
950 * Remove at a later date when no bug reports exist related to
951 * grouping pages by mobility
953 BUG_ON(page_zone(start_page
) != page_zone(end_page
));
956 for (page
= start_page
; page
<= end_page
;) {
957 /* Make sure we are not inadvertently changing nodes */
958 VM_BUG_ON(page_to_nid(page
) != zone_to_nid(zone
));
960 if (!pfn_valid_within(page_to_pfn(page
))) {
965 if (!PageBuddy(page
)) {
970 order
= page_order(page
);
971 list_move(&page
->lru
,
972 &zone
->free_area
[order
].free_list
[migratetype
]);
973 set_freepage_migratetype(page
, migratetype
);
975 pages_moved
+= 1 << order
;
981 int move_freepages_block(struct zone
*zone
, struct page
*page
,
984 unsigned long start_pfn
, end_pfn
;
985 struct page
*start_page
, *end_page
;
987 start_pfn
= page_to_pfn(page
);
988 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
989 start_page
= pfn_to_page(start_pfn
);
990 end_page
= start_page
+ pageblock_nr_pages
- 1;
991 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
993 /* Do not cross zone boundaries */
994 if (!zone_spans_pfn(zone
, start_pfn
))
996 if (!zone_spans_pfn(zone
, end_pfn
))
999 return move_freepages(zone
, start_page
, end_page
, migratetype
);
1002 static void change_pageblock_range(struct page
*pageblock_page
,
1003 int start_order
, int migratetype
)
1005 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1007 while (nr_pageblocks
--) {
1008 set_pageblock_migratetype(pageblock_page
, migratetype
);
1009 pageblock_page
+= pageblock_nr_pages
;
1013 /* Remove an element from the buddy allocator from the fallback list */
1014 static inline struct page
*
1015 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
)
1017 struct free_area
* area
;
1022 /* Find the largest possible block of pages in the other list */
1023 for (current_order
= MAX_ORDER
-1; current_order
>= order
;
1026 migratetype
= fallbacks
[start_migratetype
][i
];
1028 /* MIGRATE_RESERVE handled later if necessary */
1029 if (migratetype
== MIGRATE_RESERVE
)
1032 area
= &(zone
->free_area
[current_order
]);
1033 if (list_empty(&area
->free_list
[migratetype
]))
1036 page
= list_entry(area
->free_list
[migratetype
].next
,
1041 * If breaking a large block of pages, move all free
1042 * pages to the preferred allocation list. If falling
1043 * back for a reclaimable kernel allocation, be more
1044 * aggressive about taking ownership of free pages
1046 * On the other hand, never change migration
1047 * type of MIGRATE_CMA pageblocks nor move CMA
1048 * pages on different free lists. We don't
1049 * want unmovable pages to be allocated from
1050 * MIGRATE_CMA areas.
1052 if (!is_migrate_cma(migratetype
) &&
1053 (unlikely(current_order
>= pageblock_order
/ 2) ||
1054 start_migratetype
== MIGRATE_RECLAIMABLE
||
1055 page_group_by_mobility_disabled
)) {
1057 pages
= move_freepages_block(zone
, page
,
1060 /* Claim the whole block if over half of it is free */
1061 if (pages
>= (1 << (pageblock_order
-1)) ||
1062 page_group_by_mobility_disabled
)
1063 set_pageblock_migratetype(page
,
1066 migratetype
= start_migratetype
;
1069 /* Remove the page from the freelists */
1070 list_del(&page
->lru
);
1071 rmv_page_order(page
);
1073 /* Take ownership for orders >= pageblock_order */
1074 if (current_order
>= pageblock_order
&&
1075 !is_migrate_cma(migratetype
))
1076 change_pageblock_range(page
, current_order
,
1079 expand(zone
, page
, order
, current_order
, area
,
1080 is_migrate_cma(migratetype
)
1081 ? migratetype
: start_migratetype
);
1083 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
1084 start_migratetype
, migratetype
);
1094 * Do the hard work of removing an element from the buddy allocator.
1095 * Call me with the zone->lock already held.
1097 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
1103 page
= __rmqueue_smallest(zone
, order
, migratetype
);
1105 if (unlikely(!page
) && migratetype
!= MIGRATE_RESERVE
) {
1106 page
= __rmqueue_fallback(zone
, order
, migratetype
);
1109 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1110 * is used because __rmqueue_smallest is an inline function
1111 * and we want just one call site
1114 migratetype
= MIGRATE_RESERVE
;
1119 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1124 * Obtain a specified number of elements from the buddy allocator, all under
1125 * a single hold of the lock, for efficiency. Add them to the supplied list.
1126 * Returns the number of new pages which were placed at *list.
1128 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1129 unsigned long count
, struct list_head
*list
,
1130 int migratetype
, int cold
)
1132 int mt
= migratetype
, i
;
1134 spin_lock(&zone
->lock
);
1135 for (i
= 0; i
< count
; ++i
) {
1136 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
1137 if (unlikely(page
== NULL
))
1141 * Split buddy pages returned by expand() are received here
1142 * in physical page order. The page is added to the callers and
1143 * list and the list head then moves forward. From the callers
1144 * perspective, the linked list is ordered by page number in
1145 * some conditions. This is useful for IO devices that can
1146 * merge IO requests if the physical pages are ordered
1149 if (likely(cold
== 0))
1150 list_add(&page
->lru
, list
);
1152 list_add_tail(&page
->lru
, list
);
1153 if (IS_ENABLED(CONFIG_CMA
)) {
1154 mt
= get_pageblock_migratetype(page
);
1155 if (!is_migrate_cma(mt
) && !is_migrate_isolate(mt
))
1158 set_freepage_migratetype(page
, mt
);
1160 if (is_migrate_cma(mt
))
1161 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
1164 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
1165 spin_unlock(&zone
->lock
);
1171 * Called from the vmstat counter updater to drain pagesets of this
1172 * currently executing processor on remote nodes after they have
1175 * Note that this function must be called with the thread pinned to
1176 * a single processor.
1178 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
1180 unsigned long flags
;
1183 local_irq_save(flags
);
1184 if (pcp
->count
>= pcp
->batch
)
1185 to_drain
= pcp
->batch
;
1187 to_drain
= pcp
->count
;
1189 free_pcppages_bulk(zone
, to_drain
, pcp
);
1190 pcp
->count
-= to_drain
;
1192 local_irq_restore(flags
);
1197 * Drain pages of the indicated processor.
1199 * The processor must either be the current processor and the
1200 * thread pinned to the current processor or a processor that
1203 static void drain_pages(unsigned int cpu
)
1205 unsigned long flags
;
1208 for_each_populated_zone(zone
) {
1209 struct per_cpu_pageset
*pset
;
1210 struct per_cpu_pages
*pcp
;
1212 local_irq_save(flags
);
1213 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
1217 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1220 local_irq_restore(flags
);
1225 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1227 void drain_local_pages(void *arg
)
1229 drain_pages(smp_processor_id());
1233 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1235 * Note that this code is protected against sending an IPI to an offline
1236 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1237 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1238 * nothing keeps CPUs from showing up after we populated the cpumask and
1239 * before the call to on_each_cpu_mask().
1241 void drain_all_pages(void)
1244 struct per_cpu_pageset
*pcp
;
1248 * Allocate in the BSS so we wont require allocation in
1249 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1251 static cpumask_t cpus_with_pcps
;
1254 * We don't care about racing with CPU hotplug event
1255 * as offline notification will cause the notified
1256 * cpu to drain that CPU pcps and on_each_cpu_mask
1257 * disables preemption as part of its processing
1259 for_each_online_cpu(cpu
) {
1260 bool has_pcps
= false;
1261 for_each_populated_zone(zone
) {
1262 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
1263 if (pcp
->pcp
.count
) {
1269 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
1271 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
1273 on_each_cpu_mask(&cpus_with_pcps
, drain_local_pages
, NULL
, 1);
1276 #ifdef CONFIG_HIBERNATION
1278 void mark_free_pages(struct zone
*zone
)
1280 unsigned long pfn
, max_zone_pfn
;
1281 unsigned long flags
;
1283 struct list_head
*curr
;
1285 if (!zone
->spanned_pages
)
1288 spin_lock_irqsave(&zone
->lock
, flags
);
1290 max_zone_pfn
= zone_end_pfn(zone
);
1291 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1292 if (pfn_valid(pfn
)) {
1293 struct page
*page
= pfn_to_page(pfn
);
1295 if (!swsusp_page_is_forbidden(page
))
1296 swsusp_unset_page_free(page
);
1299 for_each_migratetype_order(order
, t
) {
1300 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
1303 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
1304 for (i
= 0; i
< (1UL << order
); i
++)
1305 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
1308 spin_unlock_irqrestore(&zone
->lock
, flags
);
1310 #endif /* CONFIG_PM */
1313 * Free a 0-order page
1314 * cold == 1 ? free a cold page : free a hot page
1316 void free_hot_cold_page(struct page
*page
, int cold
)
1318 struct zone
*zone
= page_zone(page
);
1319 struct per_cpu_pages
*pcp
;
1320 unsigned long flags
;
1323 if (!free_pages_prepare(page
, 0))
1326 migratetype
= get_pageblock_migratetype(page
);
1327 set_freepage_migratetype(page
, migratetype
);
1328 local_irq_save(flags
);
1329 __count_vm_event(PGFREE
);
1332 * We only track unmovable, reclaimable and movable on pcp lists.
1333 * Free ISOLATE pages back to the allocator because they are being
1334 * offlined but treat RESERVE as movable pages so we can get those
1335 * areas back if necessary. Otherwise, we may have to free
1336 * excessively into the page allocator
1338 if (migratetype
>= MIGRATE_PCPTYPES
) {
1339 if (unlikely(is_migrate_isolate(migratetype
))) {
1340 free_one_page(zone
, page
, 0, migratetype
);
1343 migratetype
= MIGRATE_MOVABLE
;
1346 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1348 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
1350 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
1352 if (pcp
->count
>= pcp
->high
) {
1353 free_pcppages_bulk(zone
, pcp
->batch
, pcp
);
1354 pcp
->count
-= pcp
->batch
;
1358 local_irq_restore(flags
);
1362 * Free a list of 0-order pages
1364 void free_hot_cold_page_list(struct list_head
*list
, int cold
)
1366 struct page
*page
, *next
;
1368 list_for_each_entry_safe(page
, next
, list
, lru
) {
1369 trace_mm_page_free_batched(page
, cold
);
1370 free_hot_cold_page(page
, cold
);
1375 * split_page takes a non-compound higher-order page, and splits it into
1376 * n (1<<order) sub-pages: page[0..n]
1377 * Each sub-page must be freed individually.
1379 * Note: this is probably too low level an operation for use in drivers.
1380 * Please consult with lkml before using this in your driver.
1382 void split_page(struct page
*page
, unsigned int order
)
1386 VM_BUG_ON(PageCompound(page
));
1387 VM_BUG_ON(!page_count(page
));
1389 #ifdef CONFIG_KMEMCHECK
1391 * Split shadow pages too, because free(page[0]) would
1392 * otherwise free the whole shadow.
1394 if (kmemcheck_page_is_tracked(page
))
1395 split_page(virt_to_page(page
[0].shadow
), order
);
1398 for (i
= 1; i
< (1 << order
); i
++)
1399 set_page_refcounted(page
+ i
);
1401 EXPORT_SYMBOL_GPL(split_page
);
1403 static int __isolate_free_page(struct page
*page
, unsigned int order
)
1405 unsigned long watermark
;
1409 BUG_ON(!PageBuddy(page
));
1411 zone
= page_zone(page
);
1412 mt
= get_pageblock_migratetype(page
);
1414 if (!is_migrate_isolate(mt
)) {
1415 /* Obey watermarks as if the page was being allocated */
1416 watermark
= low_wmark_pages(zone
) + (1 << order
);
1417 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
1420 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
1423 /* Remove page from free list */
1424 list_del(&page
->lru
);
1425 zone
->free_area
[order
].nr_free
--;
1426 rmv_page_order(page
);
1428 /* Set the pageblock if the isolated page is at least a pageblock */
1429 if (order
>= pageblock_order
- 1) {
1430 struct page
*endpage
= page
+ (1 << order
) - 1;
1431 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
1432 int mt
= get_pageblock_migratetype(page
);
1433 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
))
1434 set_pageblock_migratetype(page
,
1439 return 1UL << order
;
1443 * Similar to split_page except the page is already free. As this is only
1444 * being used for migration, the migratetype of the block also changes.
1445 * As this is called with interrupts disabled, the caller is responsible
1446 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1449 * Note: this is probably too low level an operation for use in drivers.
1450 * Please consult with lkml before using this in your driver.
1452 int split_free_page(struct page
*page
)
1457 order
= page_order(page
);
1459 nr_pages
= __isolate_free_page(page
, order
);
1463 /* Split into individual pages */
1464 set_page_refcounted(page
);
1465 split_page(page
, order
);
1470 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1471 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1475 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
1476 struct zone
*zone
, int order
, gfp_t gfp_flags
,
1479 unsigned long flags
;
1481 int cold
= !!(gfp_flags
& __GFP_COLD
);
1484 if (likely(order
== 0)) {
1485 struct per_cpu_pages
*pcp
;
1486 struct list_head
*list
;
1488 local_irq_save(flags
);
1489 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1490 list
= &pcp
->lists
[migratetype
];
1491 if (list_empty(list
)) {
1492 pcp
->count
+= rmqueue_bulk(zone
, 0,
1495 if (unlikely(list_empty(list
)))
1500 page
= list_entry(list
->prev
, struct page
, lru
);
1502 page
= list_entry(list
->next
, struct page
, lru
);
1504 list_del(&page
->lru
);
1507 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
1509 * __GFP_NOFAIL is not to be used in new code.
1511 * All __GFP_NOFAIL callers should be fixed so that they
1512 * properly detect and handle allocation failures.
1514 * We most definitely don't want callers attempting to
1515 * allocate greater than order-1 page units with
1518 WARN_ON_ONCE(order
> 1);
1520 spin_lock_irqsave(&zone
->lock
, flags
);
1521 page
= __rmqueue(zone
, order
, migratetype
);
1522 spin_unlock(&zone
->lock
);
1525 __mod_zone_freepage_state(zone
, -(1 << order
),
1526 get_pageblock_migratetype(page
));
1529 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
1530 zone_statistics(preferred_zone
, zone
, gfp_flags
);
1531 local_irq_restore(flags
);
1533 VM_BUG_ON(bad_range(zone
, page
));
1534 if (prep_new_page(page
, order
, gfp_flags
))
1539 local_irq_restore(flags
);
1543 #ifdef CONFIG_FAIL_PAGE_ALLOC
1546 struct fault_attr attr
;
1548 u32 ignore_gfp_highmem
;
1549 u32 ignore_gfp_wait
;
1551 } fail_page_alloc
= {
1552 .attr
= FAULT_ATTR_INITIALIZER
,
1553 .ignore_gfp_wait
= 1,
1554 .ignore_gfp_highmem
= 1,
1558 static int __init
setup_fail_page_alloc(char *str
)
1560 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
1562 __setup("fail_page_alloc=", setup_fail_page_alloc
);
1564 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1566 if (order
< fail_page_alloc
.min_order
)
1568 if (gfp_mask
& __GFP_NOFAIL
)
1570 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
1572 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
1575 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
1578 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1580 static int __init
fail_page_alloc_debugfs(void)
1582 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
1585 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
1586 &fail_page_alloc
.attr
);
1588 return PTR_ERR(dir
);
1590 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
1591 &fail_page_alloc
.ignore_gfp_wait
))
1593 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
1594 &fail_page_alloc
.ignore_gfp_highmem
))
1596 if (!debugfs_create_u32("min-order", mode
, dir
,
1597 &fail_page_alloc
.min_order
))
1602 debugfs_remove_recursive(dir
);
1607 late_initcall(fail_page_alloc_debugfs
);
1609 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1611 #else /* CONFIG_FAIL_PAGE_ALLOC */
1613 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1618 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1621 * Return true if free pages are above 'mark'. This takes into account the order
1622 * of the allocation.
1624 static bool __zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1625 int classzone_idx
, int alloc_flags
, long free_pages
)
1627 /* free_pages my go negative - that's OK */
1629 long lowmem_reserve
= z
->lowmem_reserve
[classzone_idx
];
1632 free_pages
-= (1 << order
) - 1;
1633 if (alloc_flags
& ALLOC_HIGH
)
1635 if (alloc_flags
& ALLOC_HARDER
)
1638 /* If allocation can't use CMA areas don't use free CMA pages */
1639 if (!(alloc_flags
& ALLOC_CMA
))
1640 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
1642 if (free_pages
<= min
+ lowmem_reserve
)
1644 for (o
= 0; o
< order
; o
++) {
1645 /* At the next order, this order's pages become unavailable */
1646 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1648 /* Require fewer higher order pages to be free */
1651 if (free_pages
<= min
)
1657 bool zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1658 int classzone_idx
, int alloc_flags
)
1660 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1661 zone_page_state(z
, NR_FREE_PAGES
));
1664 bool zone_watermark_ok_safe(struct zone
*z
, int order
, unsigned long mark
,
1665 int classzone_idx
, int alloc_flags
)
1667 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
1669 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
1670 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
1672 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1678 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1679 * skip over zones that are not allowed by the cpuset, or that have
1680 * been recently (in last second) found to be nearly full. See further
1681 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1682 * that have to skip over a lot of full or unallowed zones.
1684 * If the zonelist cache is present in the passed in zonelist, then
1685 * returns a pointer to the allowed node mask (either the current
1686 * tasks mems_allowed, or node_states[N_MEMORY].)
1688 * If the zonelist cache is not available for this zonelist, does
1689 * nothing and returns NULL.
1691 * If the fullzones BITMAP in the zonelist cache is stale (more than
1692 * a second since last zap'd) then we zap it out (clear its bits.)
1694 * We hold off even calling zlc_setup, until after we've checked the
1695 * first zone in the zonelist, on the theory that most allocations will
1696 * be satisfied from that first zone, so best to examine that zone as
1697 * quickly as we can.
1699 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1701 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1702 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1704 zlc
= zonelist
->zlcache_ptr
;
1708 if (time_after(jiffies
, zlc
->last_full_zap
+ HZ
)) {
1709 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1710 zlc
->last_full_zap
= jiffies
;
1713 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1714 &cpuset_current_mems_allowed
:
1715 &node_states
[N_MEMORY
];
1716 return allowednodes
;
1720 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1721 * if it is worth looking at further for free memory:
1722 * 1) Check that the zone isn't thought to be full (doesn't have its
1723 * bit set in the zonelist_cache fullzones BITMAP).
1724 * 2) Check that the zones node (obtained from the zonelist_cache
1725 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1726 * Return true (non-zero) if zone is worth looking at further, or
1727 * else return false (zero) if it is not.
1729 * This check -ignores- the distinction between various watermarks,
1730 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1731 * found to be full for any variation of these watermarks, it will
1732 * be considered full for up to one second by all requests, unless
1733 * we are so low on memory on all allowed nodes that we are forced
1734 * into the second scan of the zonelist.
1736 * In the second scan we ignore this zonelist cache and exactly
1737 * apply the watermarks to all zones, even it is slower to do so.
1738 * We are low on memory in the second scan, and should leave no stone
1739 * unturned looking for a free page.
1741 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1742 nodemask_t
*allowednodes
)
1744 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1745 int i
; /* index of *z in zonelist zones */
1746 int n
; /* node that zone *z is on */
1748 zlc
= zonelist
->zlcache_ptr
;
1752 i
= z
- zonelist
->_zonerefs
;
1755 /* This zone is worth trying if it is allowed but not full */
1756 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1760 * Given 'z' scanning a zonelist, set the corresponding bit in
1761 * zlc->fullzones, so that subsequent attempts to allocate a page
1762 * from that zone don't waste time re-examining it.
1764 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1766 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1767 int i
; /* index of *z in zonelist zones */
1769 zlc
= zonelist
->zlcache_ptr
;
1773 i
= z
- zonelist
->_zonerefs
;
1775 set_bit(i
, zlc
->fullzones
);
1779 * clear all zones full, called after direct reclaim makes progress so that
1780 * a zone that was recently full is not skipped over for up to a second
1782 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
1784 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1786 zlc
= zonelist
->zlcache_ptr
;
1790 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1793 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
1795 return node_isset(local_zone
->node
, zone
->zone_pgdat
->reclaim_nodes
);
1798 static void __paginginit
init_zone_allows_reclaim(int nid
)
1802 for_each_online_node(i
)
1803 if (node_distance(nid
, i
) <= RECLAIM_DISTANCE
)
1804 node_set(i
, NODE_DATA(nid
)->reclaim_nodes
);
1806 zone_reclaim_mode
= 1;
1809 #else /* CONFIG_NUMA */
1811 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1816 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1817 nodemask_t
*allowednodes
)
1822 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1826 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
1830 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
1835 static inline void init_zone_allows_reclaim(int nid
)
1838 #endif /* CONFIG_NUMA */
1841 * get_page_from_freelist goes through the zonelist trying to allocate
1844 static struct page
*
1845 get_page_from_freelist(gfp_t gfp_mask
, nodemask_t
*nodemask
, unsigned int order
,
1846 struct zonelist
*zonelist
, int high_zoneidx
, int alloc_flags
,
1847 struct zone
*preferred_zone
, int migratetype
)
1850 struct page
*page
= NULL
;
1853 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1854 int zlc_active
= 0; /* set if using zonelist_cache */
1855 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1857 classzone_idx
= zone_idx(preferred_zone
);
1860 * Scan zonelist, looking for a zone with enough free.
1861 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1863 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
1864 high_zoneidx
, nodemask
) {
1865 if (IS_ENABLED(CONFIG_NUMA
) && zlc_active
&&
1866 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1868 if ((alloc_flags
& ALLOC_CPUSET
) &&
1869 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1872 * When allocating a page cache page for writing, we
1873 * want to get it from a zone that is within its dirty
1874 * limit, such that no single zone holds more than its
1875 * proportional share of globally allowed dirty pages.
1876 * The dirty limits take into account the zone's
1877 * lowmem reserves and high watermark so that kswapd
1878 * should be able to balance it without having to
1879 * write pages from its LRU list.
1881 * This may look like it could increase pressure on
1882 * lower zones by failing allocations in higher zones
1883 * before they are full. But the pages that do spill
1884 * over are limited as the lower zones are protected
1885 * by this very same mechanism. It should not become
1886 * a practical burden to them.
1888 * XXX: For now, allow allocations to potentially
1889 * exceed the per-zone dirty limit in the slowpath
1890 * (ALLOC_WMARK_LOW unset) before going into reclaim,
1891 * which is important when on a NUMA setup the allowed
1892 * zones are together not big enough to reach the
1893 * global limit. The proper fix for these situations
1894 * will require awareness of zones in the
1895 * dirty-throttling and the flusher threads.
1897 if ((alloc_flags
& ALLOC_WMARK_LOW
) &&
1898 (gfp_mask
& __GFP_WRITE
) && !zone_dirty_ok(zone
))
1899 goto this_zone_full
;
1901 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
1902 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
1906 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
1907 if (zone_watermark_ok(zone
, order
, mark
,
1908 classzone_idx
, alloc_flags
))
1911 if (IS_ENABLED(CONFIG_NUMA
) &&
1912 !did_zlc_setup
&& nr_online_nodes
> 1) {
1914 * we do zlc_setup if there are multiple nodes
1915 * and before considering the first zone allowed
1918 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1923 if (zone_reclaim_mode
== 0 ||
1924 !zone_allows_reclaim(preferred_zone
, zone
))
1925 goto this_zone_full
;
1928 * As we may have just activated ZLC, check if the first
1929 * eligible zone has failed zone_reclaim recently.
1931 if (IS_ENABLED(CONFIG_NUMA
) && zlc_active
&&
1932 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1935 ret
= zone_reclaim(zone
, gfp_mask
, order
);
1937 case ZONE_RECLAIM_NOSCAN
:
1940 case ZONE_RECLAIM_FULL
:
1941 /* scanned but unreclaimable */
1944 /* did we reclaim enough */
1945 if (zone_watermark_ok(zone
, order
, mark
,
1946 classzone_idx
, alloc_flags
))
1950 * Failed to reclaim enough to meet watermark.
1951 * Only mark the zone full if checking the min
1952 * watermark or if we failed to reclaim just
1953 * 1<<order pages or else the page allocator
1954 * fastpath will prematurely mark zones full
1955 * when the watermark is between the low and
1958 if (((alloc_flags
& ALLOC_WMARK_MASK
) == ALLOC_WMARK_MIN
) ||
1959 ret
== ZONE_RECLAIM_SOME
)
1960 goto this_zone_full
;
1967 page
= buffered_rmqueue(preferred_zone
, zone
, order
,
1968 gfp_mask
, migratetype
);
1972 if (IS_ENABLED(CONFIG_NUMA
))
1973 zlc_mark_zone_full(zonelist
, z
);
1976 if (unlikely(IS_ENABLED(CONFIG_NUMA
) && page
== NULL
&& zlc_active
)) {
1977 /* Disable zlc cache for second zonelist scan */
1984 * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was
1985 * necessary to allocate the page. The expectation is
1986 * that the caller is taking steps that will free more
1987 * memory. The caller should avoid the page being used
1988 * for !PFMEMALLOC purposes.
1990 page
->pfmemalloc
= !!(alloc_flags
& ALLOC_NO_WATERMARKS
);
1996 * Large machines with many possible nodes should not always dump per-node
1997 * meminfo in irq context.
1999 static inline bool should_suppress_show_mem(void)
2004 ret
= in_interrupt();
2009 static DEFINE_RATELIMIT_STATE(nopage_rs
,
2010 DEFAULT_RATELIMIT_INTERVAL
,
2011 DEFAULT_RATELIMIT_BURST
);
2013 void warn_alloc_failed(gfp_t gfp_mask
, int order
, const char *fmt
, ...)
2015 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
2017 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
2018 debug_guardpage_minorder() > 0)
2022 * Walking all memory to count page types is very expensive and should
2023 * be inhibited in non-blockable contexts.
2025 if (!(gfp_mask
& __GFP_WAIT
))
2026 filter
|= SHOW_MEM_FILTER_PAGE_COUNT
;
2029 * This documents exceptions given to allocations in certain
2030 * contexts that are allowed to allocate outside current's set
2033 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2034 if (test_thread_flag(TIF_MEMDIE
) ||
2035 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
2036 filter
&= ~SHOW_MEM_FILTER_NODES
;
2037 if (in_interrupt() || !(gfp_mask
& __GFP_WAIT
))
2038 filter
&= ~SHOW_MEM_FILTER_NODES
;
2041 struct va_format vaf
;
2044 va_start(args
, fmt
);
2049 pr_warn("%pV", &vaf
);
2054 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
2055 current
->comm
, order
, gfp_mask
);
2058 if (!should_suppress_show_mem())
2063 should_alloc_retry(gfp_t gfp_mask
, unsigned int order
,
2064 unsigned long did_some_progress
,
2065 unsigned long pages_reclaimed
)
2067 /* Do not loop if specifically requested */
2068 if (gfp_mask
& __GFP_NORETRY
)
2071 /* Always retry if specifically requested */
2072 if (gfp_mask
& __GFP_NOFAIL
)
2076 * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
2077 * making forward progress without invoking OOM. Suspend also disables
2078 * storage devices so kswapd will not help. Bail if we are suspending.
2080 if (!did_some_progress
&& pm_suspended_storage())
2084 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
2085 * means __GFP_NOFAIL, but that may not be true in other
2088 if (order
<= PAGE_ALLOC_COSTLY_ORDER
)
2092 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
2093 * specified, then we retry until we no longer reclaim any pages
2094 * (above), or we've reclaimed an order of pages at least as
2095 * large as the allocation's order. In both cases, if the
2096 * allocation still fails, we stop retrying.
2098 if (gfp_mask
& __GFP_REPEAT
&& pages_reclaimed
< (1 << order
))
2104 static inline struct page
*
2105 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
2106 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2107 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2112 /* Acquire the OOM killer lock for the zones in zonelist */
2113 if (!try_set_zonelist_oom(zonelist
, gfp_mask
)) {
2114 schedule_timeout_uninterruptible(1);
2119 * Go through the zonelist yet one more time, keep very high watermark
2120 * here, this is only to catch a parallel oom killing, we must fail if
2121 * we're still under heavy pressure.
2123 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
,
2124 order
, zonelist
, high_zoneidx
,
2125 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
,
2126 preferred_zone
, migratetype
);
2130 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2131 /* The OOM killer will not help higher order allocs */
2132 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2134 /* The OOM killer does not needlessly kill tasks for lowmem */
2135 if (high_zoneidx
< ZONE_NORMAL
)
2138 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
2139 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
2140 * The caller should handle page allocation failure by itself if
2141 * it specifies __GFP_THISNODE.
2142 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
2144 if (gfp_mask
& __GFP_THISNODE
)
2147 /* Exhausted what can be done so it's blamo time */
2148 out_of_memory(zonelist
, gfp_mask
, order
, nodemask
, false);
2151 clear_zonelist_oom(zonelist
, gfp_mask
);
2155 #ifdef CONFIG_COMPACTION
2156 /* Try memory compaction for high-order allocations before reclaim */
2157 static struct page
*
2158 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2159 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2160 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2161 int migratetype
, bool sync_migration
,
2162 bool *contended_compaction
, bool *deferred_compaction
,
2163 unsigned long *did_some_progress
)
2168 if (compaction_deferred(preferred_zone
, order
)) {
2169 *deferred_compaction
= true;
2173 current
->flags
|= PF_MEMALLOC
;
2174 *did_some_progress
= try_to_compact_pages(zonelist
, order
, gfp_mask
,
2175 nodemask
, sync_migration
,
2176 contended_compaction
);
2177 current
->flags
&= ~PF_MEMALLOC
;
2179 if (*did_some_progress
!= COMPACT_SKIPPED
) {
2182 /* Page migration frees to the PCP lists but we want merging */
2183 drain_pages(get_cpu());
2186 page
= get_page_from_freelist(gfp_mask
, nodemask
,
2187 order
, zonelist
, high_zoneidx
,
2188 alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2189 preferred_zone
, migratetype
);
2191 preferred_zone
->compact_blockskip_flush
= false;
2192 preferred_zone
->compact_considered
= 0;
2193 preferred_zone
->compact_defer_shift
= 0;
2194 if (order
>= preferred_zone
->compact_order_failed
)
2195 preferred_zone
->compact_order_failed
= order
+ 1;
2196 count_vm_event(COMPACTSUCCESS
);
2201 * It's bad if compaction run occurs and fails.
2202 * The most likely reason is that pages exist,
2203 * but not enough to satisfy watermarks.
2205 count_vm_event(COMPACTFAIL
);
2208 * As async compaction considers a subset of pageblocks, only
2209 * defer if the failure was a sync compaction failure.
2212 defer_compaction(preferred_zone
, order
);
2220 static inline struct page
*
2221 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2222 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2223 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2224 int migratetype
, bool sync_migration
,
2225 bool *contended_compaction
, bool *deferred_compaction
,
2226 unsigned long *did_some_progress
)
2230 #endif /* CONFIG_COMPACTION */
2232 /* Perform direct synchronous page reclaim */
2234 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
, struct zonelist
*zonelist
,
2235 nodemask_t
*nodemask
)
2237 struct reclaim_state reclaim_state
;
2242 /* We now go into synchronous reclaim */
2243 cpuset_memory_pressure_bump();
2244 current
->flags
|= PF_MEMALLOC
;
2245 lockdep_set_current_reclaim_state(gfp_mask
);
2246 reclaim_state
.reclaimed_slab
= 0;
2247 current
->reclaim_state
= &reclaim_state
;
2249 progress
= try_to_free_pages(zonelist
, order
, gfp_mask
, nodemask
);
2251 current
->reclaim_state
= NULL
;
2252 lockdep_clear_current_reclaim_state();
2253 current
->flags
&= ~PF_MEMALLOC
;
2260 /* The really slow allocator path where we enter direct reclaim */
2261 static inline struct page
*
2262 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
2263 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2264 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2265 int migratetype
, unsigned long *did_some_progress
)
2267 struct page
*page
= NULL
;
2268 bool drained
= false;
2270 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, zonelist
,
2272 if (unlikely(!(*did_some_progress
)))
2275 /* After successful reclaim, reconsider all zones for allocation */
2276 if (IS_ENABLED(CONFIG_NUMA
))
2277 zlc_clear_zones_full(zonelist
);
2280 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
2281 zonelist
, high_zoneidx
,
2282 alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2283 preferred_zone
, migratetype
);
2286 * If an allocation failed after direct reclaim, it could be because
2287 * pages are pinned on the per-cpu lists. Drain them and try again
2289 if (!page
&& !drained
) {
2299 * This is called in the allocator slow-path if the allocation request is of
2300 * sufficient urgency to ignore watermarks and take other desperate measures
2302 static inline struct page
*
2303 __alloc_pages_high_priority(gfp_t gfp_mask
, unsigned int order
,
2304 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2305 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2311 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
2312 zonelist
, high_zoneidx
, ALLOC_NO_WATERMARKS
,
2313 preferred_zone
, migratetype
);
2315 if (!page
&& gfp_mask
& __GFP_NOFAIL
)
2316 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2317 } while (!page
&& (gfp_mask
& __GFP_NOFAIL
));
2323 void wake_all_kswapd(unsigned int order
, struct zonelist
*zonelist
,
2324 enum zone_type high_zoneidx
,
2325 enum zone_type classzone_idx
)
2330 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
)
2331 wakeup_kswapd(zone
, order
, classzone_idx
);
2335 gfp_to_alloc_flags(gfp_t gfp_mask
)
2337 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
2338 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2340 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2341 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
2344 * The caller may dip into page reserves a bit more if the caller
2345 * cannot run direct reclaim, or if the caller has realtime scheduling
2346 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2347 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
2349 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
2353 * Not worth trying to allocate harder for
2354 * __GFP_NOMEMALLOC even if it can't schedule.
2356 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2357 alloc_flags
|= ALLOC_HARDER
;
2359 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
2360 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
2362 alloc_flags
&= ~ALLOC_CPUSET
;
2363 } else if (unlikely(rt_task(current
)) && !in_interrupt())
2364 alloc_flags
|= ALLOC_HARDER
;
2366 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
2367 if (gfp_mask
& __GFP_MEMALLOC
)
2368 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2369 else if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
2370 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2371 else if (!in_interrupt() &&
2372 ((current
->flags
& PF_MEMALLOC
) ||
2373 unlikely(test_thread_flag(TIF_MEMDIE
))))
2374 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2377 if (allocflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
2378 alloc_flags
|= ALLOC_CMA
;
2383 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
2385 return !!(gfp_to_alloc_flags(gfp_mask
) & ALLOC_NO_WATERMARKS
);
2388 static inline struct page
*
2389 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
2390 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2391 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2394 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2395 struct page
*page
= NULL
;
2397 unsigned long pages_reclaimed
= 0;
2398 unsigned long did_some_progress
;
2399 bool sync_migration
= false;
2400 bool deferred_compaction
= false;
2401 bool contended_compaction
= false;
2404 * In the slowpath, we sanity check order to avoid ever trying to
2405 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2406 * be using allocators in order of preference for an area that is
2409 if (order
>= MAX_ORDER
) {
2410 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
2415 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
2416 * __GFP_NOWARN set) should not cause reclaim since the subsystem
2417 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
2418 * using a larger set of nodes after it has established that the
2419 * allowed per node queues are empty and that nodes are
2422 if (IS_ENABLED(CONFIG_NUMA
) &&
2423 (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
2427 if (!(gfp_mask
& __GFP_NO_KSWAPD
))
2428 wake_all_kswapd(order
, zonelist
, high_zoneidx
,
2429 zone_idx(preferred_zone
));
2432 * OK, we're below the kswapd watermark and have kicked background
2433 * reclaim. Now things get more complex, so set up alloc_flags according
2434 * to how we want to proceed.
2436 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
2439 * Find the true preferred zone if the allocation is unconstrained by
2442 if (!(alloc_flags
& ALLOC_CPUSET
) && !nodemask
)
2443 first_zones_zonelist(zonelist
, high_zoneidx
, NULL
,
2447 /* This is the last chance, in general, before the goto nopage. */
2448 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
, zonelist
,
2449 high_zoneidx
, alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2450 preferred_zone
, migratetype
);
2454 /* Allocate without watermarks if the context allows */
2455 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
2457 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
2458 * the allocation is high priority and these type of
2459 * allocations are system rather than user orientated
2461 zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
2463 page
= __alloc_pages_high_priority(gfp_mask
, order
,
2464 zonelist
, high_zoneidx
, nodemask
,
2465 preferred_zone
, migratetype
);
2471 /* Atomic allocations - we can't balance anything */
2475 /* Avoid recursion of direct reclaim */
2476 if (current
->flags
& PF_MEMALLOC
)
2479 /* Avoid allocations with no watermarks from looping endlessly */
2480 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
2484 * Try direct compaction. The first pass is asynchronous. Subsequent
2485 * attempts after direct reclaim are synchronous
2487 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
2488 zonelist
, high_zoneidx
,
2490 alloc_flags
, preferred_zone
,
2491 migratetype
, sync_migration
,
2492 &contended_compaction
,
2493 &deferred_compaction
,
2494 &did_some_progress
);
2497 sync_migration
= true;
2500 * If compaction is deferred for high-order allocations, it is because
2501 * sync compaction recently failed. In this is the case and the caller
2502 * requested a movable allocation that does not heavily disrupt the
2503 * system then fail the allocation instead of entering direct reclaim.
2505 if ((deferred_compaction
|| contended_compaction
) &&
2506 (gfp_mask
& __GFP_NO_KSWAPD
))
2509 /* Try direct reclaim and then allocating */
2510 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
,
2511 zonelist
, high_zoneidx
,
2513 alloc_flags
, preferred_zone
,
2514 migratetype
, &did_some_progress
);
2519 * If we failed to make any progress reclaiming, then we are
2520 * running out of options and have to consider going OOM
2522 if (!did_some_progress
) {
2523 if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
2524 if (oom_killer_disabled
)
2526 /* Coredumps can quickly deplete all memory reserves */
2527 if ((current
->flags
& PF_DUMPCORE
) &&
2528 !(gfp_mask
& __GFP_NOFAIL
))
2530 page
= __alloc_pages_may_oom(gfp_mask
, order
,
2531 zonelist
, high_zoneidx
,
2532 nodemask
, preferred_zone
,
2537 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2539 * The oom killer is not called for high-order
2540 * allocations that may fail, so if no progress
2541 * is being made, there are no other options and
2542 * retrying is unlikely to help.
2544 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2547 * The oom killer is not called for lowmem
2548 * allocations to prevent needlessly killing
2551 if (high_zoneidx
< ZONE_NORMAL
)
2559 /* Check if we should retry the allocation */
2560 pages_reclaimed
+= did_some_progress
;
2561 if (should_alloc_retry(gfp_mask
, order
, did_some_progress
,
2563 /* Wait for some write requests to complete then retry */
2564 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2568 * High-order allocations do not necessarily loop after
2569 * direct reclaim and reclaim/compaction depends on compaction
2570 * being called after reclaim so call directly if necessary
2572 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
2573 zonelist
, high_zoneidx
,
2575 alloc_flags
, preferred_zone
,
2576 migratetype
, sync_migration
,
2577 &contended_compaction
,
2578 &deferred_compaction
,
2579 &did_some_progress
);
2585 warn_alloc_failed(gfp_mask
, order
, NULL
);
2588 if (kmemcheck_enabled
)
2589 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
2595 * This is the 'heart' of the zoned buddy allocator.
2598 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
2599 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
2601 enum zone_type high_zoneidx
= gfp_zone(gfp_mask
);
2602 struct zone
*preferred_zone
;
2603 struct page
*page
= NULL
;
2604 int migratetype
= allocflags_to_migratetype(gfp_mask
);
2605 unsigned int cpuset_mems_cookie
;
2606 int alloc_flags
= ALLOC_WMARK_LOW
|ALLOC_CPUSET
;
2607 struct mem_cgroup
*memcg
= NULL
;
2609 gfp_mask
&= gfp_allowed_mask
;
2611 lockdep_trace_alloc(gfp_mask
);
2613 might_sleep_if(gfp_mask
& __GFP_WAIT
);
2615 if (should_fail_alloc_page(gfp_mask
, order
))
2619 * Check the zones suitable for the gfp_mask contain at least one
2620 * valid zone. It's possible to have an empty zonelist as a result
2621 * of GFP_THISNODE and a memoryless node
2623 if (unlikely(!zonelist
->_zonerefs
->zone
))
2627 * Will only have any effect when __GFP_KMEMCG is set. This is
2628 * verified in the (always inline) callee
2630 if (!memcg_kmem_newpage_charge(gfp_mask
, &memcg
, order
))
2634 cpuset_mems_cookie
= get_mems_allowed();
2636 /* The preferred zone is used for statistics later */
2637 first_zones_zonelist(zonelist
, high_zoneidx
,
2638 nodemask
? : &cpuset_current_mems_allowed
,
2640 if (!preferred_zone
)
2644 if (allocflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
2645 alloc_flags
|= ALLOC_CMA
;
2647 /* First allocation attempt */
2648 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
, order
,
2649 zonelist
, high_zoneidx
, alloc_flags
,
2650 preferred_zone
, migratetype
);
2651 if (unlikely(!page
)) {
2653 * Runtime PM, block IO and its error handling path
2654 * can deadlock because I/O on the device might not
2657 gfp_mask
= memalloc_noio_flags(gfp_mask
);
2658 page
= __alloc_pages_slowpath(gfp_mask
, order
,
2659 zonelist
, high_zoneidx
, nodemask
,
2660 preferred_zone
, migratetype
);
2663 trace_mm_page_alloc(page
, order
, gfp_mask
, migratetype
);
2667 * When updating a task's mems_allowed, it is possible to race with
2668 * parallel threads in such a way that an allocation can fail while
2669 * the mask is being updated. If a page allocation is about to fail,
2670 * check if the cpuset changed during allocation and if so, retry.
2672 if (unlikely(!put_mems_allowed(cpuset_mems_cookie
) && !page
))
2675 memcg_kmem_commit_charge(page
, memcg
, order
);
2679 EXPORT_SYMBOL(__alloc_pages_nodemask
);
2682 * Common helper functions.
2684 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
2689 * __get_free_pages() returns a 32-bit address, which cannot represent
2692 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
2694 page
= alloc_pages(gfp_mask
, order
);
2697 return (unsigned long) page_address(page
);
2699 EXPORT_SYMBOL(__get_free_pages
);
2701 unsigned long get_zeroed_page(gfp_t gfp_mask
)
2703 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
2705 EXPORT_SYMBOL(get_zeroed_page
);
2707 void __free_pages(struct page
*page
, unsigned int order
)
2709 if (put_page_testzero(page
)) {
2711 free_hot_cold_page(page
, 0);
2713 __free_pages_ok(page
, order
);
2717 EXPORT_SYMBOL(__free_pages
);
2719 void free_pages(unsigned long addr
, unsigned int order
)
2722 VM_BUG_ON(!virt_addr_valid((void *)addr
));
2723 __free_pages(virt_to_page((void *)addr
), order
);
2727 EXPORT_SYMBOL(free_pages
);
2730 * __free_memcg_kmem_pages and free_memcg_kmem_pages will free
2731 * pages allocated with __GFP_KMEMCG.
2733 * Those pages are accounted to a particular memcg, embedded in the
2734 * corresponding page_cgroup. To avoid adding a hit in the allocator to search
2735 * for that information only to find out that it is NULL for users who have no
2736 * interest in that whatsoever, we provide these functions.
2738 * The caller knows better which flags it relies on.
2740 void __free_memcg_kmem_pages(struct page
*page
, unsigned int order
)
2742 memcg_kmem_uncharge_pages(page
, order
);
2743 __free_pages(page
, order
);
2746 void free_memcg_kmem_pages(unsigned long addr
, unsigned int order
)
2749 VM_BUG_ON(!virt_addr_valid((void *)addr
));
2750 __free_memcg_kmem_pages(virt_to_page((void *)addr
), order
);
2754 static void *make_alloc_exact(unsigned long addr
, unsigned order
, size_t size
)
2757 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
2758 unsigned long used
= addr
+ PAGE_ALIGN(size
);
2760 split_page(virt_to_page((void *)addr
), order
);
2761 while (used
< alloc_end
) {
2766 return (void *)addr
;
2770 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2771 * @size: the number of bytes to allocate
2772 * @gfp_mask: GFP flags for the allocation
2774 * This function is similar to alloc_pages(), except that it allocates the
2775 * minimum number of pages to satisfy the request. alloc_pages() can only
2776 * allocate memory in power-of-two pages.
2778 * This function is also limited by MAX_ORDER.
2780 * Memory allocated by this function must be released by free_pages_exact().
2782 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
2784 unsigned int order
= get_order(size
);
2787 addr
= __get_free_pages(gfp_mask
, order
);
2788 return make_alloc_exact(addr
, order
, size
);
2790 EXPORT_SYMBOL(alloc_pages_exact
);
2793 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
2795 * @nid: the preferred node ID where memory should be allocated
2796 * @size: the number of bytes to allocate
2797 * @gfp_mask: GFP flags for the allocation
2799 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
2801 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
2804 void *alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
2806 unsigned order
= get_order(size
);
2807 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
2810 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
2812 EXPORT_SYMBOL(alloc_pages_exact_nid
);
2815 * free_pages_exact - release memory allocated via alloc_pages_exact()
2816 * @virt: the value returned by alloc_pages_exact.
2817 * @size: size of allocation, same value as passed to alloc_pages_exact().
2819 * Release the memory allocated by a previous call to alloc_pages_exact.
2821 void free_pages_exact(void *virt
, size_t size
)
2823 unsigned long addr
= (unsigned long)virt
;
2824 unsigned long end
= addr
+ PAGE_ALIGN(size
);
2826 while (addr
< end
) {
2831 EXPORT_SYMBOL(free_pages_exact
);
2834 * nr_free_zone_pages - count number of pages beyond high watermark
2835 * @offset: The zone index of the highest zone
2837 * nr_free_zone_pages() counts the number of counts pages which are beyond the
2838 * high watermark within all zones at or below a given zone index. For each
2839 * zone, the number of pages is calculated as:
2840 * present_pages - high_pages
2842 static unsigned long nr_free_zone_pages(int offset
)
2847 /* Just pick one node, since fallback list is circular */
2848 unsigned long sum
= 0;
2850 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
2852 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
2853 unsigned long size
= zone
->managed_pages
;
2854 unsigned long high
= high_wmark_pages(zone
);
2863 * nr_free_buffer_pages - count number of pages beyond high watermark
2865 * nr_free_buffer_pages() counts the number of pages which are beyond the high
2866 * watermark within ZONE_DMA and ZONE_NORMAL.
2868 unsigned long nr_free_buffer_pages(void)
2870 return nr_free_zone_pages(gfp_zone(GFP_USER
));
2872 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
2875 * nr_free_pagecache_pages - count number of pages beyond high watermark
2877 * nr_free_pagecache_pages() counts the number of pages which are beyond the
2878 * high watermark within all zones.
2880 unsigned long nr_free_pagecache_pages(void)
2882 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
2885 static inline void show_node(struct zone
*zone
)
2887 if (IS_ENABLED(CONFIG_NUMA
))
2888 printk("Node %d ", zone_to_nid(zone
));
2891 void si_meminfo(struct sysinfo
*val
)
2893 val
->totalram
= totalram_pages
;
2895 val
->freeram
= global_page_state(NR_FREE_PAGES
);
2896 val
->bufferram
= nr_blockdev_pages();
2897 val
->totalhigh
= totalhigh_pages
;
2898 val
->freehigh
= nr_free_highpages();
2899 val
->mem_unit
= PAGE_SIZE
;
2902 EXPORT_SYMBOL(si_meminfo
);
2905 void si_meminfo_node(struct sysinfo
*val
, int nid
)
2907 pg_data_t
*pgdat
= NODE_DATA(nid
);
2909 val
->totalram
= pgdat
->node_present_pages
;
2910 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
2911 #ifdef CONFIG_HIGHMEM
2912 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].managed_pages
;
2913 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
2919 val
->mem_unit
= PAGE_SIZE
;
2924 * Determine whether the node should be displayed or not, depending on whether
2925 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
2927 bool skip_free_areas_node(unsigned int flags
, int nid
)
2930 unsigned int cpuset_mems_cookie
;
2932 if (!(flags
& SHOW_MEM_FILTER_NODES
))
2936 cpuset_mems_cookie
= get_mems_allowed();
2937 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
2938 } while (!put_mems_allowed(cpuset_mems_cookie
));
2943 #define K(x) ((x) << (PAGE_SHIFT-10))
2945 static void show_migration_types(unsigned char type
)
2947 static const char types
[MIGRATE_TYPES
] = {
2948 [MIGRATE_UNMOVABLE
] = 'U',
2949 [MIGRATE_RECLAIMABLE
] = 'E',
2950 [MIGRATE_MOVABLE
] = 'M',
2951 [MIGRATE_RESERVE
] = 'R',
2953 [MIGRATE_CMA
] = 'C',
2955 #ifdef CONFIG_MEMORY_ISOLATION
2956 [MIGRATE_ISOLATE
] = 'I',
2959 char tmp
[MIGRATE_TYPES
+ 1];
2963 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
2964 if (type
& (1 << i
))
2969 printk("(%s) ", tmp
);
2973 * Show free area list (used inside shift_scroll-lock stuff)
2974 * We also calculate the percentage fragmentation. We do this by counting the
2975 * memory on each free list with the exception of the first item on the list.
2976 * Suppresses nodes that are not allowed by current's cpuset if
2977 * SHOW_MEM_FILTER_NODES is passed.
2979 void show_free_areas(unsigned int filter
)
2984 for_each_populated_zone(zone
) {
2985 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
2988 printk("%s per-cpu:\n", zone
->name
);
2990 for_each_online_cpu(cpu
) {
2991 struct per_cpu_pageset
*pageset
;
2993 pageset
= per_cpu_ptr(zone
->pageset
, cpu
);
2995 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
2996 cpu
, pageset
->pcp
.high
,
2997 pageset
->pcp
.batch
, pageset
->pcp
.count
);
3001 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3002 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3004 " dirty:%lu writeback:%lu unstable:%lu\n"
3005 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3006 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3008 global_page_state(NR_ACTIVE_ANON
),
3009 global_page_state(NR_INACTIVE_ANON
),
3010 global_page_state(NR_ISOLATED_ANON
),
3011 global_page_state(NR_ACTIVE_FILE
),
3012 global_page_state(NR_INACTIVE_FILE
),
3013 global_page_state(NR_ISOLATED_FILE
),
3014 global_page_state(NR_UNEVICTABLE
),
3015 global_page_state(NR_FILE_DIRTY
),
3016 global_page_state(NR_WRITEBACK
),
3017 global_page_state(NR_UNSTABLE_NFS
),
3018 global_page_state(NR_FREE_PAGES
),
3019 global_page_state(NR_SLAB_RECLAIMABLE
),
3020 global_page_state(NR_SLAB_UNRECLAIMABLE
),
3021 global_page_state(NR_FILE_MAPPED
),
3022 global_page_state(NR_SHMEM
),
3023 global_page_state(NR_PAGETABLE
),
3024 global_page_state(NR_BOUNCE
),
3025 global_page_state(NR_FREE_CMA_PAGES
));
3027 for_each_populated_zone(zone
) {
3030 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3038 " active_anon:%lukB"
3039 " inactive_anon:%lukB"
3040 " active_file:%lukB"
3041 " inactive_file:%lukB"
3042 " unevictable:%lukB"
3043 " isolated(anon):%lukB"
3044 " isolated(file):%lukB"
3052 " slab_reclaimable:%lukB"
3053 " slab_unreclaimable:%lukB"
3054 " kernel_stack:%lukB"
3059 " writeback_tmp:%lukB"
3060 " pages_scanned:%lu"
3061 " all_unreclaimable? %s"
3064 K(zone_page_state(zone
, NR_FREE_PAGES
)),
3065 K(min_wmark_pages(zone
)),
3066 K(low_wmark_pages(zone
)),
3067 K(high_wmark_pages(zone
)),
3068 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
3069 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
3070 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
3071 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
3072 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
3073 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
3074 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
3075 K(zone
->present_pages
),
3076 K(zone
->managed_pages
),
3077 K(zone_page_state(zone
, NR_MLOCK
)),
3078 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
3079 K(zone_page_state(zone
, NR_WRITEBACK
)),
3080 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
3081 K(zone_page_state(zone
, NR_SHMEM
)),
3082 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
3083 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
3084 zone_page_state(zone
, NR_KERNEL_STACK
) *
3086 K(zone_page_state(zone
, NR_PAGETABLE
)),
3087 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
3088 K(zone_page_state(zone
, NR_BOUNCE
)),
3089 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)),
3090 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
3091 zone
->pages_scanned
,
3092 (zone
->all_unreclaimable
? "yes" : "no")
3094 printk("lowmem_reserve[]:");
3095 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3096 printk(" %lu", zone
->lowmem_reserve
[i
]);
3100 for_each_populated_zone(zone
) {
3101 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
3102 unsigned char types
[MAX_ORDER
];
3104 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3107 printk("%s: ", zone
->name
);
3109 spin_lock_irqsave(&zone
->lock
, flags
);
3110 for (order
= 0; order
< MAX_ORDER
; order
++) {
3111 struct free_area
*area
= &zone
->free_area
[order
];
3114 nr
[order
] = area
->nr_free
;
3115 total
+= nr
[order
] << order
;
3118 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
3119 if (!list_empty(&area
->free_list
[type
]))
3120 types
[order
] |= 1 << type
;
3123 spin_unlock_irqrestore(&zone
->lock
, flags
);
3124 for (order
= 0; order
< MAX_ORDER
; order
++) {
3125 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
3127 show_migration_types(types
[order
]);
3129 printk("= %lukB\n", K(total
));
3132 hugetlb_show_meminfo();
3134 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
3136 show_swap_cache_info();
3139 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
3141 zoneref
->zone
= zone
;
3142 zoneref
->zone_idx
= zone_idx(zone
);
3146 * Builds allocation fallback zone lists.
3148 * Add all populated zones of a node to the zonelist.
3150 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
3151 int nr_zones
, enum zone_type zone_type
)
3155 BUG_ON(zone_type
>= MAX_NR_ZONES
);
3160 zone
= pgdat
->node_zones
+ zone_type
;
3161 if (populated_zone(zone
)) {
3162 zoneref_set_zone(zone
,
3163 &zonelist
->_zonerefs
[nr_zones
++]);
3164 check_highest_zone(zone_type
);
3167 } while (zone_type
);
3174 * 0 = automatic detection of better ordering.
3175 * 1 = order by ([node] distance, -zonetype)
3176 * 2 = order by (-zonetype, [node] distance)
3178 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3179 * the same zonelist. So only NUMA can configure this param.
3181 #define ZONELIST_ORDER_DEFAULT 0
3182 #define ZONELIST_ORDER_NODE 1
3183 #define ZONELIST_ORDER_ZONE 2
3185 /* zonelist order in the kernel.
3186 * set_zonelist_order() will set this to NODE or ZONE.
3188 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3189 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
3193 /* The value user specified ....changed by config */
3194 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3195 /* string for sysctl */
3196 #define NUMA_ZONELIST_ORDER_LEN 16
3197 char numa_zonelist_order
[16] = "default";
3200 * interface for configure zonelist ordering.
3201 * command line option "numa_zonelist_order"
3202 * = "[dD]efault - default, automatic configuration.
3203 * = "[nN]ode - order by node locality, then by zone within node
3204 * = "[zZ]one - order by zone, then by locality within zone
3207 static int __parse_numa_zonelist_order(char *s
)
3209 if (*s
== 'd' || *s
== 'D') {
3210 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3211 } else if (*s
== 'n' || *s
== 'N') {
3212 user_zonelist_order
= ZONELIST_ORDER_NODE
;
3213 } else if (*s
== 'z' || *s
== 'Z') {
3214 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
3217 "Ignoring invalid numa_zonelist_order value: "
3224 static __init
int setup_numa_zonelist_order(char *s
)
3231 ret
= __parse_numa_zonelist_order(s
);
3233 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
3237 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
3240 * sysctl handler for numa_zonelist_order
3242 int numa_zonelist_order_handler(ctl_table
*table
, int write
,
3243 void __user
*buffer
, size_t *length
,
3246 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
3248 static DEFINE_MUTEX(zl_order_mutex
);
3250 mutex_lock(&zl_order_mutex
);
3252 strcpy(saved_string
, (char*)table
->data
);
3253 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
3257 int oldval
= user_zonelist_order
;
3258 if (__parse_numa_zonelist_order((char*)table
->data
)) {
3260 * bogus value. restore saved string
3262 strncpy((char*)table
->data
, saved_string
,
3263 NUMA_ZONELIST_ORDER_LEN
);
3264 user_zonelist_order
= oldval
;
3265 } else if (oldval
!= user_zonelist_order
) {
3266 mutex_lock(&zonelists_mutex
);
3267 build_all_zonelists(NULL
, NULL
);
3268 mutex_unlock(&zonelists_mutex
);
3272 mutex_unlock(&zl_order_mutex
);
3277 #define MAX_NODE_LOAD (nr_online_nodes)
3278 static int node_load
[MAX_NUMNODES
];
3281 * find_next_best_node - find the next node that should appear in a given node's fallback list
3282 * @node: node whose fallback list we're appending
3283 * @used_node_mask: nodemask_t of already used nodes
3285 * We use a number of factors to determine which is the next node that should
3286 * appear on a given node's fallback list. The node should not have appeared
3287 * already in @node's fallback list, and it should be the next closest node
3288 * according to the distance array (which contains arbitrary distance values
3289 * from each node to each node in the system), and should also prefer nodes
3290 * with no CPUs, since presumably they'll have very little allocation pressure
3291 * on them otherwise.
3292 * It returns -1 if no node is found.
3294 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
3297 int min_val
= INT_MAX
;
3298 int best_node
= NUMA_NO_NODE
;
3299 const struct cpumask
*tmp
= cpumask_of_node(0);
3301 /* Use the local node if we haven't already */
3302 if (!node_isset(node
, *used_node_mask
)) {
3303 node_set(node
, *used_node_mask
);
3307 for_each_node_state(n
, N_MEMORY
) {
3309 /* Don't want a node to appear more than once */
3310 if (node_isset(n
, *used_node_mask
))
3313 /* Use the distance array to find the distance */
3314 val
= node_distance(node
, n
);
3316 /* Penalize nodes under us ("prefer the next node") */
3319 /* Give preference to headless and unused nodes */
3320 tmp
= cpumask_of_node(n
);
3321 if (!cpumask_empty(tmp
))
3322 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
3324 /* Slight preference for less loaded node */
3325 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
3326 val
+= node_load
[n
];
3328 if (val
< min_val
) {
3335 node_set(best_node
, *used_node_mask
);
3342 * Build zonelists ordered by node and zones within node.
3343 * This results in maximum locality--normal zone overflows into local
3344 * DMA zone, if any--but risks exhausting DMA zone.
3346 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
3349 struct zonelist
*zonelist
;
3351 zonelist
= &pgdat
->node_zonelists
[0];
3352 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
3354 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3356 zonelist
->_zonerefs
[j
].zone
= NULL
;
3357 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3361 * Build gfp_thisnode zonelists
3363 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
3366 struct zonelist
*zonelist
;
3368 zonelist
= &pgdat
->node_zonelists
[1];
3369 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
3370 zonelist
->_zonerefs
[j
].zone
= NULL
;
3371 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3375 * Build zonelists ordered by zone and nodes within zones.
3376 * This results in conserving DMA zone[s] until all Normal memory is
3377 * exhausted, but results in overflowing to remote node while memory
3378 * may still exist in local DMA zone.
3380 static int node_order
[MAX_NUMNODES
];
3382 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
3385 int zone_type
; /* needs to be signed */
3387 struct zonelist
*zonelist
;
3389 zonelist
= &pgdat
->node_zonelists
[0];
3391 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
3392 for (j
= 0; j
< nr_nodes
; j
++) {
3393 node
= node_order
[j
];
3394 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
3395 if (populated_zone(z
)) {
3397 &zonelist
->_zonerefs
[pos
++]);
3398 check_highest_zone(zone_type
);
3402 zonelist
->_zonerefs
[pos
].zone
= NULL
;
3403 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
3406 static int default_zonelist_order(void)
3409 unsigned long low_kmem_size
,total_size
;
3413 * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
3414 * If they are really small and used heavily, the system can fall
3415 * into OOM very easily.
3416 * This function detect ZONE_DMA/DMA32 size and configures zone order.
3418 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
3421 for_each_online_node(nid
) {
3422 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
3423 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
3424 if (populated_zone(z
)) {
3425 if (zone_type
< ZONE_NORMAL
)
3426 low_kmem_size
+= z
->present_pages
;
3427 total_size
+= z
->present_pages
;
3428 } else if (zone_type
== ZONE_NORMAL
) {
3430 * If any node has only lowmem, then node order
3431 * is preferred to allow kernel allocations
3432 * locally; otherwise, they can easily infringe
3433 * on other nodes when there is an abundance of
3434 * lowmem available to allocate from.
3436 return ZONELIST_ORDER_NODE
;
3440 if (!low_kmem_size
|| /* there are no DMA area. */
3441 low_kmem_size
> total_size
/2) /* DMA/DMA32 is big. */
3442 return ZONELIST_ORDER_NODE
;
3444 * look into each node's config.
3445 * If there is a node whose DMA/DMA32 memory is very big area on
3446 * local memory, NODE_ORDER may be suitable.
3448 average_size
= total_size
/
3449 (nodes_weight(node_states
[N_MEMORY
]) + 1);
3450 for_each_online_node(nid
) {
3453 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
3454 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
3455 if (populated_zone(z
)) {
3456 if (zone_type
< ZONE_NORMAL
)
3457 low_kmem_size
+= z
->present_pages
;
3458 total_size
+= z
->present_pages
;
3461 if (low_kmem_size
&&
3462 total_size
> average_size
&& /* ignore small node */
3463 low_kmem_size
> total_size
* 70/100)
3464 return ZONELIST_ORDER_NODE
;
3466 return ZONELIST_ORDER_ZONE
;
3469 static void set_zonelist_order(void)
3471 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
3472 current_zonelist_order
= default_zonelist_order();
3474 current_zonelist_order
= user_zonelist_order
;
3477 static void build_zonelists(pg_data_t
*pgdat
)
3481 nodemask_t used_mask
;
3482 int local_node
, prev_node
;
3483 struct zonelist
*zonelist
;
3484 int order
= current_zonelist_order
;
3486 /* initialize zonelists */
3487 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
3488 zonelist
= pgdat
->node_zonelists
+ i
;
3489 zonelist
->_zonerefs
[0].zone
= NULL
;
3490 zonelist
->_zonerefs
[0].zone_idx
= 0;
3493 /* NUMA-aware ordering of nodes */
3494 local_node
= pgdat
->node_id
;
3495 load
= nr_online_nodes
;
3496 prev_node
= local_node
;
3497 nodes_clear(used_mask
);
3499 memset(node_order
, 0, sizeof(node_order
));
3502 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
3504 * We don't want to pressure a particular node.
3505 * So adding penalty to the first node in same
3506 * distance group to make it round-robin.
3508 if (node_distance(local_node
, node
) !=
3509 node_distance(local_node
, prev_node
))
3510 node_load
[node
] = load
;
3514 if (order
== ZONELIST_ORDER_NODE
)
3515 build_zonelists_in_node_order(pgdat
, node
);
3517 node_order
[j
++] = node
; /* remember order */
3520 if (order
== ZONELIST_ORDER_ZONE
) {
3521 /* calculate node order -- i.e., DMA last! */
3522 build_zonelists_in_zone_order(pgdat
, j
);
3525 build_thisnode_zonelists(pgdat
);
3528 /* Construct the zonelist performance cache - see further mmzone.h */
3529 static void build_zonelist_cache(pg_data_t
*pgdat
)
3531 struct zonelist
*zonelist
;
3532 struct zonelist_cache
*zlc
;
3535 zonelist
= &pgdat
->node_zonelists
[0];
3536 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
3537 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
3538 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
3539 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
3542 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3544 * Return node id of node used for "local" allocations.
3545 * I.e., first node id of first zone in arg node's generic zonelist.
3546 * Used for initializing percpu 'numa_mem', which is used primarily
3547 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3549 int local_memory_node(int node
)
3553 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
3554 gfp_zone(GFP_KERNEL
),
3561 #else /* CONFIG_NUMA */
3563 static void set_zonelist_order(void)
3565 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
3568 static void build_zonelists(pg_data_t
*pgdat
)
3570 int node
, local_node
;
3572 struct zonelist
*zonelist
;
3574 local_node
= pgdat
->node_id
;
3576 zonelist
= &pgdat
->node_zonelists
[0];
3577 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
3580 * Now we build the zonelist so that it contains the zones
3581 * of all the other nodes.
3582 * We don't want to pressure a particular node, so when
3583 * building the zones for node N, we make sure that the
3584 * zones coming right after the local ones are those from
3585 * node N+1 (modulo N)
3587 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
3588 if (!node_online(node
))
3590 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3593 for (node
= 0; node
< local_node
; node
++) {
3594 if (!node_online(node
))
3596 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3600 zonelist
->_zonerefs
[j
].zone
= NULL
;
3601 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3604 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3605 static void build_zonelist_cache(pg_data_t
*pgdat
)
3607 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
3610 #endif /* CONFIG_NUMA */
3613 * Boot pageset table. One per cpu which is going to be used for all
3614 * zones and all nodes. The parameters will be set in such a way
3615 * that an item put on a list will immediately be handed over to
3616 * the buddy list. This is safe since pageset manipulation is done
3617 * with interrupts disabled.
3619 * The boot_pagesets must be kept even after bootup is complete for
3620 * unused processors and/or zones. They do play a role for bootstrapping
3621 * hotplugged processors.
3623 * zoneinfo_show() and maybe other functions do
3624 * not check if the processor is online before following the pageset pointer.
3625 * Other parts of the kernel may not check if the zone is available.
3627 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
3628 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
3629 static void setup_zone_pageset(struct zone
*zone
);
3632 * Global mutex to protect against size modification of zonelists
3633 * as well as to serialize pageset setup for the new populated zone.
3635 DEFINE_MUTEX(zonelists_mutex
);
3637 /* return values int ....just for stop_machine() */
3638 static int __build_all_zonelists(void *data
)
3642 pg_data_t
*self
= data
;
3645 memset(node_load
, 0, sizeof(node_load
));
3648 if (self
&& !node_online(self
->node_id
)) {
3649 build_zonelists(self
);
3650 build_zonelist_cache(self
);
3653 for_each_online_node(nid
) {
3654 pg_data_t
*pgdat
= NODE_DATA(nid
);
3656 build_zonelists(pgdat
);
3657 build_zonelist_cache(pgdat
);
3661 * Initialize the boot_pagesets that are going to be used
3662 * for bootstrapping processors. The real pagesets for
3663 * each zone will be allocated later when the per cpu
3664 * allocator is available.
3666 * boot_pagesets are used also for bootstrapping offline
3667 * cpus if the system is already booted because the pagesets
3668 * are needed to initialize allocators on a specific cpu too.
3669 * F.e. the percpu allocator needs the page allocator which
3670 * needs the percpu allocator in order to allocate its pagesets
3671 * (a chicken-egg dilemma).
3673 for_each_possible_cpu(cpu
) {
3674 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
3676 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3678 * We now know the "local memory node" for each node--
3679 * i.e., the node of the first zone in the generic zonelist.
3680 * Set up numa_mem percpu variable for on-line cpus. During
3681 * boot, only the boot cpu should be on-line; we'll init the
3682 * secondary cpus' numa_mem as they come on-line. During
3683 * node/memory hotplug, we'll fixup all on-line cpus.
3685 if (cpu_online(cpu
))
3686 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
3694 * Called with zonelists_mutex held always
3695 * unless system_state == SYSTEM_BOOTING.
3697 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
3699 set_zonelist_order();
3701 if (system_state
== SYSTEM_BOOTING
) {
3702 __build_all_zonelists(NULL
);
3703 mminit_verify_zonelist();
3704 cpuset_init_current_mems_allowed();
3706 /* we have to stop all cpus to guarantee there is no user
3708 #ifdef CONFIG_MEMORY_HOTPLUG
3710 setup_zone_pageset(zone
);
3712 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
3713 /* cpuset refresh routine should be here */
3715 vm_total_pages
= nr_free_pagecache_pages();
3717 * Disable grouping by mobility if the number of pages in the
3718 * system is too low to allow the mechanism to work. It would be
3719 * more accurate, but expensive to check per-zone. This check is
3720 * made on memory-hotadd so a system can start with mobility
3721 * disabled and enable it later
3723 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
3724 page_group_by_mobility_disabled
= 1;
3726 page_group_by_mobility_disabled
= 0;
3728 printk("Built %i zonelists in %s order, mobility grouping %s. "
3729 "Total pages: %ld\n",
3731 zonelist_order_name
[current_zonelist_order
],
3732 page_group_by_mobility_disabled
? "off" : "on",
3735 printk("Policy zone: %s\n", zone_names
[policy_zone
]);
3740 * Helper functions to size the waitqueue hash table.
3741 * Essentially these want to choose hash table sizes sufficiently
3742 * large so that collisions trying to wait on pages are rare.
3743 * But in fact, the number of active page waitqueues on typical
3744 * systems is ridiculously low, less than 200. So this is even
3745 * conservative, even though it seems large.
3747 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3748 * waitqueues, i.e. the size of the waitq table given the number of pages.
3750 #define PAGES_PER_WAITQUEUE 256
3752 #ifndef CONFIG_MEMORY_HOTPLUG
3753 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3755 unsigned long size
= 1;
3757 pages
/= PAGES_PER_WAITQUEUE
;
3759 while (size
< pages
)
3763 * Once we have dozens or even hundreds of threads sleeping
3764 * on IO we've got bigger problems than wait queue collision.
3765 * Limit the size of the wait table to a reasonable size.
3767 size
= min(size
, 4096UL);
3769 return max(size
, 4UL);
3773 * A zone's size might be changed by hot-add, so it is not possible to determine
3774 * a suitable size for its wait_table. So we use the maximum size now.
3776 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
3778 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
3779 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3780 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
3782 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3783 * or more by the traditional way. (See above). It equals:
3785 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
3786 * ia64(16K page size) : = ( 8G + 4M)byte.
3787 * powerpc (64K page size) : = (32G +16M)byte.
3789 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3796 * This is an integer logarithm so that shifts can be used later
3797 * to extract the more random high bits from the multiplicative
3798 * hash function before the remainder is taken.
3800 static inline unsigned long wait_table_bits(unsigned long size
)
3805 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
3808 * Check if a pageblock contains reserved pages
3810 static int pageblock_is_reserved(unsigned long start_pfn
, unsigned long end_pfn
)
3814 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
3815 if (!pfn_valid_within(pfn
) || PageReserved(pfn_to_page(pfn
)))
3822 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3823 * of blocks reserved is based on min_wmark_pages(zone). The memory within
3824 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3825 * higher will lead to a bigger reserve which will get freed as contiguous
3826 * blocks as reclaim kicks in
3828 static void setup_zone_migrate_reserve(struct zone
*zone
)
3830 unsigned long start_pfn
, pfn
, end_pfn
, block_end_pfn
;
3832 unsigned long block_migratetype
;
3836 * Get the start pfn, end pfn and the number of blocks to reserve
3837 * We have to be careful to be aligned to pageblock_nr_pages to
3838 * make sure that we always check pfn_valid for the first page in
3841 start_pfn
= zone
->zone_start_pfn
;
3842 end_pfn
= zone_end_pfn(zone
);
3843 start_pfn
= roundup(start_pfn
, pageblock_nr_pages
);
3844 reserve
= roundup(min_wmark_pages(zone
), pageblock_nr_pages
) >>
3848 * Reserve blocks are generally in place to help high-order atomic
3849 * allocations that are short-lived. A min_free_kbytes value that
3850 * would result in more than 2 reserve blocks for atomic allocations
3851 * is assumed to be in place to help anti-fragmentation for the
3852 * future allocation of hugepages at runtime.
3854 reserve
= min(2, reserve
);
3856 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
3857 if (!pfn_valid(pfn
))
3859 page
= pfn_to_page(pfn
);
3861 /* Watch out for overlapping nodes */
3862 if (page_to_nid(page
) != zone_to_nid(zone
))
3865 block_migratetype
= get_pageblock_migratetype(page
);
3867 /* Only test what is necessary when the reserves are not met */
3870 * Blocks with reserved pages will never free, skip
3873 block_end_pfn
= min(pfn
+ pageblock_nr_pages
, end_pfn
);
3874 if (pageblock_is_reserved(pfn
, block_end_pfn
))
3877 /* If this block is reserved, account for it */
3878 if (block_migratetype
== MIGRATE_RESERVE
) {
3883 /* Suitable for reserving if this block is movable */
3884 if (block_migratetype
== MIGRATE_MOVABLE
) {
3885 set_pageblock_migratetype(page
,
3887 move_freepages_block(zone
, page
,
3895 * If the reserve is met and this is a previous reserved block,
3898 if (block_migratetype
== MIGRATE_RESERVE
) {
3899 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3900 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
3906 * Initially all pages are reserved - free ones are freed
3907 * up by free_all_bootmem() once the early boot process is
3908 * done. Non-atomic initialization, single-pass.
3910 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
3911 unsigned long start_pfn
, enum memmap_context context
)
3914 unsigned long end_pfn
= start_pfn
+ size
;
3918 if (highest_memmap_pfn
< end_pfn
- 1)
3919 highest_memmap_pfn
= end_pfn
- 1;
3921 z
= &NODE_DATA(nid
)->node_zones
[zone
];
3922 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
3924 * There can be holes in boot-time mem_map[]s
3925 * handed to this function. They do not
3926 * exist on hotplugged memory.
3928 if (context
== MEMMAP_EARLY
) {
3929 if (!early_pfn_valid(pfn
))
3931 if (!early_pfn_in_nid(pfn
, nid
))
3934 page
= pfn_to_page(pfn
);
3935 set_page_links(page
, zone
, nid
, pfn
);
3936 mminit_verify_page_links(page
, zone
, nid
, pfn
);
3937 init_page_count(page
);
3938 page_mapcount_reset(page
);
3939 page_nid_reset_last(page
);
3940 SetPageReserved(page
);
3942 * Mark the block movable so that blocks are reserved for
3943 * movable at startup. This will force kernel allocations
3944 * to reserve their blocks rather than leaking throughout
3945 * the address space during boot when many long-lived
3946 * kernel allocations are made. Later some blocks near
3947 * the start are marked MIGRATE_RESERVE by
3948 * setup_zone_migrate_reserve()
3950 * bitmap is created for zone's valid pfn range. but memmap
3951 * can be created for invalid pages (for alignment)
3952 * check here not to call set_pageblock_migratetype() against
3955 if ((z
->zone_start_pfn
<= pfn
)
3956 && (pfn
< zone_end_pfn(z
))
3957 && !(pfn
& (pageblock_nr_pages
- 1)))
3958 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3960 INIT_LIST_HEAD(&page
->lru
);
3961 #ifdef WANT_PAGE_VIRTUAL
3962 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
3963 if (!is_highmem_idx(zone
))
3964 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
3969 static void __meminit
zone_init_free_lists(struct zone
*zone
)
3972 for_each_migratetype_order(order
, t
) {
3973 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
3974 zone
->free_area
[order
].nr_free
= 0;
3978 #ifndef __HAVE_ARCH_MEMMAP_INIT
3979 #define memmap_init(size, nid, zone, start_pfn) \
3980 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
3983 static int __meminit
zone_batchsize(struct zone
*zone
)
3989 * The per-cpu-pages pools are set to around 1000th of the
3990 * size of the zone. But no more than 1/2 of a meg.
3992 * OK, so we don't know how big the cache is. So guess.
3994 batch
= zone
->managed_pages
/ 1024;
3995 if (batch
* PAGE_SIZE
> 512 * 1024)
3996 batch
= (512 * 1024) / PAGE_SIZE
;
3997 batch
/= 4; /* We effectively *= 4 below */
4002 * Clamp the batch to a 2^n - 1 value. Having a power
4003 * of 2 value was found to be more likely to have
4004 * suboptimal cache aliasing properties in some cases.
4006 * For example if 2 tasks are alternately allocating
4007 * batches of pages, one task can end up with a lot
4008 * of pages of one half of the possible page colors
4009 * and the other with pages of the other colors.
4011 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
4016 /* The deferral and batching of frees should be suppressed under NOMMU
4019 * The problem is that NOMMU needs to be able to allocate large chunks
4020 * of contiguous memory as there's no hardware page translation to
4021 * assemble apparent contiguous memory from discontiguous pages.
4023 * Queueing large contiguous runs of pages for batching, however,
4024 * causes the pages to actually be freed in smaller chunks. As there
4025 * can be a significant delay between the individual batches being
4026 * recycled, this leads to the once large chunks of space being
4027 * fragmented and becoming unavailable for high-order allocations.
4033 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
4035 struct per_cpu_pages
*pcp
;
4038 memset(p
, 0, sizeof(*p
));
4042 pcp
->high
= 6 * batch
;
4043 pcp
->batch
= max(1UL, 1 * batch
);
4044 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
4045 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
4049 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
4050 * to the value high for the pageset p.
4053 static void setup_pagelist_highmark(struct per_cpu_pageset
*p
,
4056 struct per_cpu_pages
*pcp
;
4060 pcp
->batch
= max(1UL, high
/4);
4061 if ((high
/4) > (PAGE_SHIFT
* 8))
4062 pcp
->batch
= PAGE_SHIFT
* 8;
4065 static void __meminit
setup_zone_pageset(struct zone
*zone
)
4069 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
4071 for_each_possible_cpu(cpu
) {
4072 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
4074 setup_pageset(pcp
, zone_batchsize(zone
));
4076 if (percpu_pagelist_fraction
)
4077 setup_pagelist_highmark(pcp
,
4078 (zone
->managed_pages
/
4079 percpu_pagelist_fraction
));
4084 * Allocate per cpu pagesets and initialize them.
4085 * Before this call only boot pagesets were available.
4087 void __init
setup_per_cpu_pageset(void)
4091 for_each_populated_zone(zone
)
4092 setup_zone_pageset(zone
);
4095 static noinline __init_refok
4096 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
4099 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
4103 * The per-page waitqueue mechanism uses hashed waitqueues
4106 zone
->wait_table_hash_nr_entries
=
4107 wait_table_hash_nr_entries(zone_size_pages
);
4108 zone
->wait_table_bits
=
4109 wait_table_bits(zone
->wait_table_hash_nr_entries
);
4110 alloc_size
= zone
->wait_table_hash_nr_entries
4111 * sizeof(wait_queue_head_t
);
4113 if (!slab_is_available()) {
4114 zone
->wait_table
= (wait_queue_head_t
*)
4115 alloc_bootmem_node_nopanic(pgdat
, alloc_size
);
4118 * This case means that a zone whose size was 0 gets new memory
4119 * via memory hot-add.
4120 * But it may be the case that a new node was hot-added. In
4121 * this case vmalloc() will not be able to use this new node's
4122 * memory - this wait_table must be initialized to use this new
4123 * node itself as well.
4124 * To use this new node's memory, further consideration will be
4127 zone
->wait_table
= vmalloc(alloc_size
);
4129 if (!zone
->wait_table
)
4132 for(i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
4133 init_waitqueue_head(zone
->wait_table
+ i
);
4138 static __meminit
void zone_pcp_init(struct zone
*zone
)
4141 * per cpu subsystem is not up at this point. The following code
4142 * relies on the ability of the linker to provide the
4143 * offset of a (static) per cpu variable into the per cpu area.
4145 zone
->pageset
= &boot_pageset
;
4147 if (zone
->present_pages
)
4148 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
4149 zone
->name
, zone
->present_pages
,
4150 zone_batchsize(zone
));
4153 int __meminit
init_currently_empty_zone(struct zone
*zone
,
4154 unsigned long zone_start_pfn
,
4156 enum memmap_context context
)
4158 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
4160 ret
= zone_wait_table_init(zone
, size
);
4163 pgdat
->nr_zones
= zone_idx(zone
) + 1;
4165 zone
->zone_start_pfn
= zone_start_pfn
;
4167 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
4168 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4170 (unsigned long)zone_idx(zone
),
4171 zone_start_pfn
, (zone_start_pfn
+ size
));
4173 zone_init_free_lists(zone
);
4178 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4179 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4181 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4182 * Architectures may implement their own version but if add_active_range()
4183 * was used and there are no special requirements, this is a convenient
4186 int __meminit
__early_pfn_to_nid(unsigned long pfn
)
4188 unsigned long start_pfn
, end_pfn
;
4191 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
4192 if (start_pfn
<= pfn
&& pfn
< end_pfn
)
4194 /* This is a memory hole */
4197 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4199 int __meminit
early_pfn_to_nid(unsigned long pfn
)
4203 nid
= __early_pfn_to_nid(pfn
);
4206 /* just returns 0 */
4210 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
4211 bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
4215 nid
= __early_pfn_to_nid(pfn
);
4216 if (nid
>= 0 && nid
!= node
)
4223 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
4224 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4225 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
4227 * If an architecture guarantees that all ranges registered with
4228 * add_active_ranges() contain no holes and may be freed, this
4229 * this function may be used instead of calling free_bootmem() manually.
4231 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
4233 unsigned long start_pfn
, end_pfn
;
4236 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
4237 start_pfn
= min(start_pfn
, max_low_pfn
);
4238 end_pfn
= min(end_pfn
, max_low_pfn
);
4240 if (start_pfn
< end_pfn
)
4241 free_bootmem_node(NODE_DATA(this_nid
),
4242 PFN_PHYS(start_pfn
),
4243 (end_pfn
- start_pfn
) << PAGE_SHIFT
);
4248 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4249 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4251 * If an architecture guarantees that all ranges registered with
4252 * add_active_ranges() contain no holes and may be freed, this
4253 * function may be used instead of calling memory_present() manually.
4255 void __init
sparse_memory_present_with_active_regions(int nid
)
4257 unsigned long start_pfn
, end_pfn
;
4260 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
4261 memory_present(this_nid
, start_pfn
, end_pfn
);
4265 * get_pfn_range_for_nid - Return the start and end page frames for a node
4266 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4267 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
4268 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
4270 * It returns the start and end page frame of a node based on information
4271 * provided by an arch calling add_active_range(). If called for a node
4272 * with no available memory, a warning is printed and the start and end
4275 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
4276 unsigned long *start_pfn
, unsigned long *end_pfn
)
4278 unsigned long this_start_pfn
, this_end_pfn
;
4284 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
4285 *start_pfn
= min(*start_pfn
, this_start_pfn
);
4286 *end_pfn
= max(*end_pfn
, this_end_pfn
);
4289 if (*start_pfn
== -1UL)
4294 * This finds a zone that can be used for ZONE_MOVABLE pages. The
4295 * assumption is made that zones within a node are ordered in monotonic
4296 * increasing memory addresses so that the "highest" populated zone is used
4298 static void __init
find_usable_zone_for_movable(void)
4301 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
4302 if (zone_index
== ZONE_MOVABLE
)
4305 if (arch_zone_highest_possible_pfn
[zone_index
] >
4306 arch_zone_lowest_possible_pfn
[zone_index
])
4310 VM_BUG_ON(zone_index
== -1);
4311 movable_zone
= zone_index
;
4315 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4316 * because it is sized independent of architecture. Unlike the other zones,
4317 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4318 * in each node depending on the size of each node and how evenly kernelcore
4319 * is distributed. This helper function adjusts the zone ranges
4320 * provided by the architecture for a given node by using the end of the
4321 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4322 * zones within a node are in order of monotonic increases memory addresses
4324 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
4325 unsigned long zone_type
,
4326 unsigned long node_start_pfn
,
4327 unsigned long node_end_pfn
,
4328 unsigned long *zone_start_pfn
,
4329 unsigned long *zone_end_pfn
)
4331 /* Only adjust if ZONE_MOVABLE is on this node */
4332 if (zone_movable_pfn
[nid
]) {
4333 /* Size ZONE_MOVABLE */
4334 if (zone_type
== ZONE_MOVABLE
) {
4335 *zone_start_pfn
= zone_movable_pfn
[nid
];
4336 *zone_end_pfn
= min(node_end_pfn
,
4337 arch_zone_highest_possible_pfn
[movable_zone
]);
4339 /* Adjust for ZONE_MOVABLE starting within this range */
4340 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
4341 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
4342 *zone_end_pfn
= zone_movable_pfn
[nid
];
4344 /* Check if this whole range is within ZONE_MOVABLE */
4345 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
4346 *zone_start_pfn
= *zone_end_pfn
;
4351 * Return the number of pages a zone spans in a node, including holes
4352 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4354 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4355 unsigned long zone_type
,
4356 unsigned long *ignored
)
4358 unsigned long node_start_pfn
, node_end_pfn
;
4359 unsigned long zone_start_pfn
, zone_end_pfn
;
4361 /* Get the start and end of the node and zone */
4362 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
4363 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
4364 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
4365 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4366 node_start_pfn
, node_end_pfn
,
4367 &zone_start_pfn
, &zone_end_pfn
);
4369 /* Check that this node has pages within the zone's required range */
4370 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
4373 /* Move the zone boundaries inside the node if necessary */
4374 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
4375 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
4377 /* Return the spanned pages */
4378 return zone_end_pfn
- zone_start_pfn
;
4382 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4383 * then all holes in the requested range will be accounted for.
4385 unsigned long __meminit
__absent_pages_in_range(int nid
,
4386 unsigned long range_start_pfn
,
4387 unsigned long range_end_pfn
)
4389 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
4390 unsigned long start_pfn
, end_pfn
;
4393 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
4394 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
4395 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
4396 nr_absent
-= end_pfn
- start_pfn
;
4402 * absent_pages_in_range - Return number of page frames in holes within a range
4403 * @start_pfn: The start PFN to start searching for holes
4404 * @end_pfn: The end PFN to stop searching for holes
4406 * It returns the number of pages frames in memory holes within a range.
4408 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
4409 unsigned long end_pfn
)
4411 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
4414 /* Return the number of page frames in holes in a zone on a node */
4415 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4416 unsigned long zone_type
,
4417 unsigned long *ignored
)
4419 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
4420 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
4421 unsigned long node_start_pfn
, node_end_pfn
;
4422 unsigned long zone_start_pfn
, zone_end_pfn
;
4424 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
4425 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
4426 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
4428 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4429 node_start_pfn
, node_end_pfn
,
4430 &zone_start_pfn
, &zone_end_pfn
);
4431 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
4434 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4435 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4436 unsigned long zone_type
,
4437 unsigned long *zones_size
)
4439 return zones_size
[zone_type
];
4442 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4443 unsigned long zone_type
,
4444 unsigned long *zholes_size
)
4449 return zholes_size
[zone_type
];
4452 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4454 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
4455 unsigned long *zones_size
, unsigned long *zholes_size
)
4457 unsigned long realtotalpages
, totalpages
= 0;
4460 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4461 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
4463 pgdat
->node_spanned_pages
= totalpages
;
4465 realtotalpages
= totalpages
;
4466 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4468 zone_absent_pages_in_node(pgdat
->node_id
, i
,
4470 pgdat
->node_present_pages
= realtotalpages
;
4471 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
4475 #ifndef CONFIG_SPARSEMEM
4477 * Calculate the size of the zone->blockflags rounded to an unsigned long
4478 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4479 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4480 * round what is now in bits to nearest long in bits, then return it in
4483 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
4485 unsigned long usemapsize
;
4487 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
4488 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
4489 usemapsize
= usemapsize
>> pageblock_order
;
4490 usemapsize
*= NR_PAGEBLOCK_BITS
;
4491 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
4493 return usemapsize
/ 8;
4496 static void __init
setup_usemap(struct pglist_data
*pgdat
,
4498 unsigned long zone_start_pfn
,
4499 unsigned long zonesize
)
4501 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
4502 zone
->pageblock_flags
= NULL
;
4504 zone
->pageblock_flags
= alloc_bootmem_node_nopanic(pgdat
,
4508 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
4509 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
4510 #endif /* CONFIG_SPARSEMEM */
4512 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4514 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4515 void __init
set_pageblock_order(void)
4519 /* Check that pageblock_nr_pages has not already been setup */
4520 if (pageblock_order
)
4523 if (HPAGE_SHIFT
> PAGE_SHIFT
)
4524 order
= HUGETLB_PAGE_ORDER
;
4526 order
= MAX_ORDER
- 1;
4529 * Assume the largest contiguous order of interest is a huge page.
4530 * This value may be variable depending on boot parameters on IA64 and
4533 pageblock_order
= order
;
4535 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4538 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4539 * is unused as pageblock_order is set at compile-time. See
4540 * include/linux/pageblock-flags.h for the values of pageblock_order based on
4543 void __init
set_pageblock_order(void)
4547 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4549 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
4550 unsigned long present_pages
)
4552 unsigned long pages
= spanned_pages
;
4555 * Provide a more accurate estimation if there are holes within
4556 * the zone and SPARSEMEM is in use. If there are holes within the
4557 * zone, each populated memory region may cost us one or two extra
4558 * memmap pages due to alignment because memmap pages for each
4559 * populated regions may not naturally algined on page boundary.
4560 * So the (present_pages >> 4) heuristic is a tradeoff for that.
4562 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
4563 IS_ENABLED(CONFIG_SPARSEMEM
))
4564 pages
= present_pages
;
4566 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
4570 * Set up the zone data structures:
4571 * - mark all pages reserved
4572 * - mark all memory queues empty
4573 * - clear the memory bitmaps
4575 * NOTE: pgdat should get zeroed by caller.
4577 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
,
4578 unsigned long *zones_size
, unsigned long *zholes_size
)
4581 int nid
= pgdat
->node_id
;
4582 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
4585 pgdat_resize_init(pgdat
);
4586 #ifdef CONFIG_NUMA_BALANCING
4587 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
4588 pgdat
->numabalancing_migrate_nr_pages
= 0;
4589 pgdat
->numabalancing_migrate_next_window
= jiffies
;
4591 init_waitqueue_head(&pgdat
->kswapd_wait
);
4592 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
4593 pgdat_page_cgroup_init(pgdat
);
4595 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4596 struct zone
*zone
= pgdat
->node_zones
+ j
;
4597 unsigned long size
, realsize
, freesize
, memmap_pages
;
4599 size
= zone_spanned_pages_in_node(nid
, j
, zones_size
);
4600 realsize
= freesize
= size
- zone_absent_pages_in_node(nid
, j
,
4604 * Adjust freesize so that it accounts for how much memory
4605 * is used by this zone for memmap. This affects the watermark
4606 * and per-cpu initialisations
4608 memmap_pages
= calc_memmap_size(size
, realsize
);
4609 if (freesize
>= memmap_pages
) {
4610 freesize
-= memmap_pages
;
4613 " %s zone: %lu pages used for memmap\n",
4614 zone_names
[j
], memmap_pages
);
4617 " %s zone: %lu pages exceeds freesize %lu\n",
4618 zone_names
[j
], memmap_pages
, freesize
);
4620 /* Account for reserved pages */
4621 if (j
== 0 && freesize
> dma_reserve
) {
4622 freesize
-= dma_reserve
;
4623 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
4624 zone_names
[0], dma_reserve
);
4627 if (!is_highmem_idx(j
))
4628 nr_kernel_pages
+= freesize
;
4629 /* Charge for highmem memmap if there are enough kernel pages */
4630 else if (nr_kernel_pages
> memmap_pages
* 2)
4631 nr_kernel_pages
-= memmap_pages
;
4632 nr_all_pages
+= freesize
;
4634 zone
->spanned_pages
= size
;
4635 zone
->present_pages
= realsize
;
4637 * Set an approximate value for lowmem here, it will be adjusted
4638 * when the bootmem allocator frees pages into the buddy system.
4639 * And all highmem pages will be managed by the buddy system.
4641 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
4644 zone
->min_unmapped_pages
= (freesize
*sysctl_min_unmapped_ratio
)
4646 zone
->min_slab_pages
= (freesize
* sysctl_min_slab_ratio
) / 100;
4648 zone
->name
= zone_names
[j
];
4649 spin_lock_init(&zone
->lock
);
4650 spin_lock_init(&zone
->lru_lock
);
4651 zone_seqlock_init(zone
);
4652 zone
->zone_pgdat
= pgdat
;
4654 zone_pcp_init(zone
);
4655 lruvec_init(&zone
->lruvec
);
4659 set_pageblock_order();
4660 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
4661 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
4662 size
, MEMMAP_EARLY
);
4664 memmap_init(size
, nid
, j
, zone_start_pfn
);
4665 zone_start_pfn
+= size
;
4669 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
4671 /* Skip empty nodes */
4672 if (!pgdat
->node_spanned_pages
)
4675 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4676 /* ia64 gets its own node_mem_map, before this, without bootmem */
4677 if (!pgdat
->node_mem_map
) {
4678 unsigned long size
, start
, end
;
4682 * The zone's endpoints aren't required to be MAX_ORDER
4683 * aligned but the node_mem_map endpoints must be in order
4684 * for the buddy allocator to function correctly.
4686 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
4687 end
= pgdat_end_pfn(pgdat
);
4688 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
4689 size
= (end
- start
) * sizeof(struct page
);
4690 map
= alloc_remap(pgdat
->node_id
, size
);
4692 map
= alloc_bootmem_node_nopanic(pgdat
, size
);
4693 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
4695 #ifndef CONFIG_NEED_MULTIPLE_NODES
4697 * With no DISCONTIG, the global mem_map is just set as node 0's
4699 if (pgdat
== NODE_DATA(0)) {
4700 mem_map
= NODE_DATA(0)->node_mem_map
;
4701 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4702 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
4703 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
4704 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4707 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4710 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
4711 unsigned long node_start_pfn
, unsigned long *zholes_size
)
4713 pg_data_t
*pgdat
= NODE_DATA(nid
);
4715 /* pg_data_t should be reset to zero when it's allocated */
4716 WARN_ON(pgdat
->nr_zones
|| pgdat
->classzone_idx
);
4718 pgdat
->node_id
= nid
;
4719 pgdat
->node_start_pfn
= node_start_pfn
;
4720 init_zone_allows_reclaim(nid
);
4721 calculate_node_totalpages(pgdat
, zones_size
, zholes_size
);
4723 alloc_node_mem_map(pgdat
);
4724 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4725 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
4726 nid
, (unsigned long)pgdat
,
4727 (unsigned long)pgdat
->node_mem_map
);
4730 free_area_init_core(pgdat
, zones_size
, zholes_size
);
4733 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4735 #if MAX_NUMNODES > 1
4737 * Figure out the number of possible node ids.
4739 static void __init
setup_nr_node_ids(void)
4742 unsigned int highest
= 0;
4744 for_each_node_mask(node
, node_possible_map
)
4746 nr_node_ids
= highest
+ 1;
4749 static inline void setup_nr_node_ids(void)
4755 * node_map_pfn_alignment - determine the maximum internode alignment
4757 * This function should be called after node map is populated and sorted.
4758 * It calculates the maximum power of two alignment which can distinguish
4761 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
4762 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
4763 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
4764 * shifted, 1GiB is enough and this function will indicate so.
4766 * This is used to test whether pfn -> nid mapping of the chosen memory
4767 * model has fine enough granularity to avoid incorrect mapping for the
4768 * populated node map.
4770 * Returns the determined alignment in pfn's. 0 if there is no alignment
4771 * requirement (single node).
4773 unsigned long __init
node_map_pfn_alignment(void)
4775 unsigned long accl_mask
= 0, last_end
= 0;
4776 unsigned long start
, end
, mask
;
4780 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
4781 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
4788 * Start with a mask granular enough to pin-point to the
4789 * start pfn and tick off bits one-by-one until it becomes
4790 * too coarse to separate the current node from the last.
4792 mask
= ~((1 << __ffs(start
)) - 1);
4793 while (mask
&& last_end
<= (start
& (mask
<< 1)))
4796 /* accumulate all internode masks */
4800 /* convert mask to number of pages */
4801 return ~accl_mask
+ 1;
4804 /* Find the lowest pfn for a node */
4805 static unsigned long __init
find_min_pfn_for_node(int nid
)
4807 unsigned long min_pfn
= ULONG_MAX
;
4808 unsigned long start_pfn
;
4811 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
4812 min_pfn
= min(min_pfn
, start_pfn
);
4814 if (min_pfn
== ULONG_MAX
) {
4816 "Could not find start_pfn for node %d\n", nid
);
4824 * find_min_pfn_with_active_regions - Find the minimum PFN registered
4826 * It returns the minimum PFN based on information provided via
4827 * add_active_range().
4829 unsigned long __init
find_min_pfn_with_active_regions(void)
4831 return find_min_pfn_for_node(MAX_NUMNODES
);
4835 * early_calculate_totalpages()
4836 * Sum pages in active regions for movable zone.
4837 * Populate N_MEMORY for calculating usable_nodes.
4839 static unsigned long __init
early_calculate_totalpages(void)
4841 unsigned long totalpages
= 0;
4842 unsigned long start_pfn
, end_pfn
;
4845 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
4846 unsigned long pages
= end_pfn
- start_pfn
;
4848 totalpages
+= pages
;
4850 node_set_state(nid
, N_MEMORY
);
4856 * Find the PFN the Movable zone begins in each node. Kernel memory
4857 * is spread evenly between nodes as long as the nodes have enough
4858 * memory. When they don't, some nodes will have more kernelcore than
4861 static void __init
find_zone_movable_pfns_for_nodes(void)
4864 unsigned long usable_startpfn
;
4865 unsigned long kernelcore_node
, kernelcore_remaining
;
4866 /* save the state before borrow the nodemask */
4867 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
4868 unsigned long totalpages
= early_calculate_totalpages();
4869 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
4872 * If movablecore was specified, calculate what size of
4873 * kernelcore that corresponds so that memory usable for
4874 * any allocation type is evenly spread. If both kernelcore
4875 * and movablecore are specified, then the value of kernelcore
4876 * will be used for required_kernelcore if it's greater than
4877 * what movablecore would have allowed.
4879 if (required_movablecore
) {
4880 unsigned long corepages
;
4883 * Round-up so that ZONE_MOVABLE is at least as large as what
4884 * was requested by the user
4886 required_movablecore
=
4887 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
4888 corepages
= totalpages
- required_movablecore
;
4890 required_kernelcore
= max(required_kernelcore
, corepages
);
4893 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
4894 if (!required_kernelcore
)
4897 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
4898 find_usable_zone_for_movable();
4899 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
4902 /* Spread kernelcore memory as evenly as possible throughout nodes */
4903 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4904 for_each_node_state(nid
, N_MEMORY
) {
4905 unsigned long start_pfn
, end_pfn
;
4908 * Recalculate kernelcore_node if the division per node
4909 * now exceeds what is necessary to satisfy the requested
4910 * amount of memory for the kernel
4912 if (required_kernelcore
< kernelcore_node
)
4913 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4916 * As the map is walked, we track how much memory is usable
4917 * by the kernel using kernelcore_remaining. When it is
4918 * 0, the rest of the node is usable by ZONE_MOVABLE
4920 kernelcore_remaining
= kernelcore_node
;
4922 /* Go through each range of PFNs within this node */
4923 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
4924 unsigned long size_pages
;
4926 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
4927 if (start_pfn
>= end_pfn
)
4930 /* Account for what is only usable for kernelcore */
4931 if (start_pfn
< usable_startpfn
) {
4932 unsigned long kernel_pages
;
4933 kernel_pages
= min(end_pfn
, usable_startpfn
)
4936 kernelcore_remaining
-= min(kernel_pages
,
4937 kernelcore_remaining
);
4938 required_kernelcore
-= min(kernel_pages
,
4939 required_kernelcore
);
4941 /* Continue if range is now fully accounted */
4942 if (end_pfn
<= usable_startpfn
) {
4945 * Push zone_movable_pfn to the end so
4946 * that if we have to rebalance
4947 * kernelcore across nodes, we will
4948 * not double account here
4950 zone_movable_pfn
[nid
] = end_pfn
;
4953 start_pfn
= usable_startpfn
;
4957 * The usable PFN range for ZONE_MOVABLE is from
4958 * start_pfn->end_pfn. Calculate size_pages as the
4959 * number of pages used as kernelcore
4961 size_pages
= end_pfn
- start_pfn
;
4962 if (size_pages
> kernelcore_remaining
)
4963 size_pages
= kernelcore_remaining
;
4964 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
4967 * Some kernelcore has been met, update counts and
4968 * break if the kernelcore for this node has been
4971 required_kernelcore
-= min(required_kernelcore
,
4973 kernelcore_remaining
-= size_pages
;
4974 if (!kernelcore_remaining
)
4980 * If there is still required_kernelcore, we do another pass with one
4981 * less node in the count. This will push zone_movable_pfn[nid] further
4982 * along on the nodes that still have memory until kernelcore is
4986 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
4989 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
4990 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
4991 zone_movable_pfn
[nid
] =
4992 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
4995 /* restore the node_state */
4996 node_states
[N_MEMORY
] = saved_node_state
;
4999 /* Any regular or high memory on that node ? */
5000 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
5002 enum zone_type zone_type
;
5004 if (N_MEMORY
== N_NORMAL_MEMORY
)
5007 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
5008 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
5009 if (zone
->present_pages
) {
5010 node_set_state(nid
, N_HIGH_MEMORY
);
5011 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
5012 zone_type
<= ZONE_NORMAL
)
5013 node_set_state(nid
, N_NORMAL_MEMORY
);
5020 * free_area_init_nodes - Initialise all pg_data_t and zone data
5021 * @max_zone_pfn: an array of max PFNs for each zone
5023 * This will call free_area_init_node() for each active node in the system.
5024 * Using the page ranges provided by add_active_range(), the size of each
5025 * zone in each node and their holes is calculated. If the maximum PFN
5026 * between two adjacent zones match, it is assumed that the zone is empty.
5027 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5028 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5029 * starts where the previous one ended. For example, ZONE_DMA32 starts
5030 * at arch_max_dma_pfn.
5032 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
5034 unsigned long start_pfn
, end_pfn
;
5037 /* Record where the zone boundaries are */
5038 memset(arch_zone_lowest_possible_pfn
, 0,
5039 sizeof(arch_zone_lowest_possible_pfn
));
5040 memset(arch_zone_highest_possible_pfn
, 0,
5041 sizeof(arch_zone_highest_possible_pfn
));
5042 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
5043 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
5044 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
5045 if (i
== ZONE_MOVABLE
)
5047 arch_zone_lowest_possible_pfn
[i
] =
5048 arch_zone_highest_possible_pfn
[i
-1];
5049 arch_zone_highest_possible_pfn
[i
] =
5050 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
5052 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
5053 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
5055 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
5056 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
5057 find_zone_movable_pfns_for_nodes();
5059 /* Print out the zone ranges */
5060 printk("Zone ranges:\n");
5061 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5062 if (i
== ZONE_MOVABLE
)
5064 printk(KERN_CONT
" %-8s ", zone_names
[i
]);
5065 if (arch_zone_lowest_possible_pfn
[i
] ==
5066 arch_zone_highest_possible_pfn
[i
])
5067 printk(KERN_CONT
"empty\n");
5069 printk(KERN_CONT
"[mem %0#10lx-%0#10lx]\n",
5070 arch_zone_lowest_possible_pfn
[i
] << PAGE_SHIFT
,
5071 (arch_zone_highest_possible_pfn
[i
]
5072 << PAGE_SHIFT
) - 1);
5075 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5076 printk("Movable zone start for each node\n");
5077 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
5078 if (zone_movable_pfn
[i
])
5079 printk(" Node %d: %#010lx\n", i
,
5080 zone_movable_pfn
[i
] << PAGE_SHIFT
);
5083 /* Print out the early node map */
5084 printk("Early memory node ranges\n");
5085 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
5086 printk(" node %3d: [mem %#010lx-%#010lx]\n", nid
,
5087 start_pfn
<< PAGE_SHIFT
, (end_pfn
<< PAGE_SHIFT
) - 1);
5089 /* Initialise every node */
5090 mminit_verify_pageflags_layout();
5091 setup_nr_node_ids();
5092 for_each_online_node(nid
) {
5093 pg_data_t
*pgdat
= NODE_DATA(nid
);
5094 free_area_init_node(nid
, NULL
,
5095 find_min_pfn_for_node(nid
), NULL
);
5097 /* Any memory on that node */
5098 if (pgdat
->node_present_pages
)
5099 node_set_state(nid
, N_MEMORY
);
5100 check_for_memory(pgdat
, nid
);
5104 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
5106 unsigned long long coremem
;
5110 coremem
= memparse(p
, &p
);
5111 *core
= coremem
>> PAGE_SHIFT
;
5113 /* Paranoid check that UL is enough for the coremem value */
5114 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
5120 * kernelcore=size sets the amount of memory for use for allocations that
5121 * cannot be reclaimed or migrated.
5123 static int __init
cmdline_parse_kernelcore(char *p
)
5125 return cmdline_parse_core(p
, &required_kernelcore
);
5129 * movablecore=size sets the amount of memory for use for allocations that
5130 * can be reclaimed or migrated.
5132 static int __init
cmdline_parse_movablecore(char *p
)
5134 return cmdline_parse_core(p
, &required_movablecore
);
5137 early_param("kernelcore", cmdline_parse_kernelcore
);
5138 early_param("movablecore", cmdline_parse_movablecore
);
5140 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5142 unsigned long free_reserved_area(unsigned long start
, unsigned long end
,
5143 int poison
, char *s
)
5145 unsigned long pages
, pos
;
5147 pos
= start
= PAGE_ALIGN(start
);
5149 for (pages
= 0; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
5151 memset((void *)pos
, poison
, PAGE_SIZE
);
5152 free_reserved_page(virt_to_page(pos
));
5156 pr_info("Freeing %s memory: %ldK (%lx - %lx)\n",
5157 s
, pages
<< (PAGE_SHIFT
- 10), start
, end
);
5162 #ifdef CONFIG_HIGHMEM
5163 void free_highmem_page(struct page
*page
)
5165 __free_reserved_page(page
);
5172 * set_dma_reserve - set the specified number of pages reserved in the first zone
5173 * @new_dma_reserve: The number of pages to mark reserved
5175 * The per-cpu batchsize and zone watermarks are determined by present_pages.
5176 * In the DMA zone, a significant percentage may be consumed by kernel image
5177 * and other unfreeable allocations which can skew the watermarks badly. This
5178 * function may optionally be used to account for unfreeable pages in the
5179 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
5180 * smaller per-cpu batchsize.
5182 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
5184 dma_reserve
= new_dma_reserve
;
5187 void __init
free_area_init(unsigned long *zones_size
)
5189 free_area_init_node(0, zones_size
,
5190 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
5193 static int page_alloc_cpu_notify(struct notifier_block
*self
,
5194 unsigned long action
, void *hcpu
)
5196 int cpu
= (unsigned long)hcpu
;
5198 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
5199 lru_add_drain_cpu(cpu
);
5203 * Spill the event counters of the dead processor
5204 * into the current processors event counters.
5205 * This artificially elevates the count of the current
5208 vm_events_fold_cpu(cpu
);
5211 * Zero the differential counters of the dead processor
5212 * so that the vm statistics are consistent.
5214 * This is only okay since the processor is dead and cannot
5215 * race with what we are doing.
5217 refresh_cpu_vm_stats(cpu
);
5222 void __init
page_alloc_init(void)
5224 hotcpu_notifier(page_alloc_cpu_notify
, 0);
5228 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
5229 * or min_free_kbytes changes.
5231 static void calculate_totalreserve_pages(void)
5233 struct pglist_data
*pgdat
;
5234 unsigned long reserve_pages
= 0;
5235 enum zone_type i
, j
;
5237 for_each_online_pgdat(pgdat
) {
5238 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5239 struct zone
*zone
= pgdat
->node_zones
+ i
;
5240 unsigned long max
= 0;
5242 /* Find valid and maximum lowmem_reserve in the zone */
5243 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
5244 if (zone
->lowmem_reserve
[j
] > max
)
5245 max
= zone
->lowmem_reserve
[j
];
5248 /* we treat the high watermark as reserved pages. */
5249 max
+= high_wmark_pages(zone
);
5251 if (max
> zone
->managed_pages
)
5252 max
= zone
->managed_pages
;
5253 reserve_pages
+= max
;
5255 * Lowmem reserves are not available to
5256 * GFP_HIGHUSER page cache allocations and
5257 * kswapd tries to balance zones to their high
5258 * watermark. As a result, neither should be
5259 * regarded as dirtyable memory, to prevent a
5260 * situation where reclaim has to clean pages
5261 * in order to balance the zones.
5263 zone
->dirty_balance_reserve
= max
;
5266 dirty_balance_reserve
= reserve_pages
;
5267 totalreserve_pages
= reserve_pages
;
5271 * setup_per_zone_lowmem_reserve - called whenever
5272 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
5273 * has a correct pages reserved value, so an adequate number of
5274 * pages are left in the zone after a successful __alloc_pages().
5276 static void setup_per_zone_lowmem_reserve(void)
5278 struct pglist_data
*pgdat
;
5279 enum zone_type j
, idx
;
5281 for_each_online_pgdat(pgdat
) {
5282 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5283 struct zone
*zone
= pgdat
->node_zones
+ j
;
5284 unsigned long managed_pages
= zone
->managed_pages
;
5286 zone
->lowmem_reserve
[j
] = 0;
5290 struct zone
*lower_zone
;
5294 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
5295 sysctl_lowmem_reserve_ratio
[idx
] = 1;
5297 lower_zone
= pgdat
->node_zones
+ idx
;
5298 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
5299 sysctl_lowmem_reserve_ratio
[idx
];
5300 managed_pages
+= lower_zone
->managed_pages
;
5305 /* update totalreserve_pages */
5306 calculate_totalreserve_pages();
5309 static void __setup_per_zone_wmarks(void)
5311 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
5312 unsigned long lowmem_pages
= 0;
5314 unsigned long flags
;
5316 /* Calculate total number of !ZONE_HIGHMEM pages */
5317 for_each_zone(zone
) {
5318 if (!is_highmem(zone
))
5319 lowmem_pages
+= zone
->managed_pages
;
5322 for_each_zone(zone
) {
5325 spin_lock_irqsave(&zone
->lock
, flags
);
5326 tmp
= (u64
)pages_min
* zone
->managed_pages
;
5327 do_div(tmp
, lowmem_pages
);
5328 if (is_highmem(zone
)) {
5330 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
5331 * need highmem pages, so cap pages_min to a small
5334 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
5335 * deltas controls asynch page reclaim, and so should
5336 * not be capped for highmem.
5338 unsigned long min_pages
;
5340 min_pages
= zone
->managed_pages
/ 1024;
5341 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
5342 zone
->watermark
[WMARK_MIN
] = min_pages
;
5345 * If it's a lowmem zone, reserve a number of pages
5346 * proportionate to the zone's size.
5348 zone
->watermark
[WMARK_MIN
] = tmp
;
5351 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + (tmp
>> 2);
5352 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + (tmp
>> 1);
5354 setup_zone_migrate_reserve(zone
);
5355 spin_unlock_irqrestore(&zone
->lock
, flags
);
5358 /* update totalreserve_pages */
5359 calculate_totalreserve_pages();
5363 * setup_per_zone_wmarks - called when min_free_kbytes changes
5364 * or when memory is hot-{added|removed}
5366 * Ensures that the watermark[min,low,high] values for each zone are set
5367 * correctly with respect to min_free_kbytes.
5369 void setup_per_zone_wmarks(void)
5371 mutex_lock(&zonelists_mutex
);
5372 __setup_per_zone_wmarks();
5373 mutex_unlock(&zonelists_mutex
);
5377 * The inactive anon list should be small enough that the VM never has to
5378 * do too much work, but large enough that each inactive page has a chance
5379 * to be referenced again before it is swapped out.
5381 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
5382 * INACTIVE_ANON pages on this zone's LRU, maintained by the
5383 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
5384 * the anonymous pages are kept on the inactive list.
5387 * memory ratio inactive anon
5388 * -------------------------------------
5397 static void __meminit
calculate_zone_inactive_ratio(struct zone
*zone
)
5399 unsigned int gb
, ratio
;
5401 /* Zone size in gigabytes */
5402 gb
= zone
->managed_pages
>> (30 - PAGE_SHIFT
);
5404 ratio
= int_sqrt(10 * gb
);
5408 zone
->inactive_ratio
= ratio
;
5411 static void __meminit
setup_per_zone_inactive_ratio(void)
5416 calculate_zone_inactive_ratio(zone
);
5420 * Initialise min_free_kbytes.
5422 * For small machines we want it small (128k min). For large machines
5423 * we want it large (64MB max). But it is not linear, because network
5424 * bandwidth does not increase linearly with machine size. We use
5426 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5427 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
5443 int __meminit
init_per_zone_wmark_min(void)
5445 unsigned long lowmem_kbytes
;
5447 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
5449 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
5450 if (min_free_kbytes
< 128)
5451 min_free_kbytes
= 128;
5452 if (min_free_kbytes
> 65536)
5453 min_free_kbytes
= 65536;
5454 setup_per_zone_wmarks();
5455 refresh_zone_stat_thresholds();
5456 setup_per_zone_lowmem_reserve();
5457 setup_per_zone_inactive_ratio();
5460 module_init(init_per_zone_wmark_min
)
5463 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5464 * that we can call two helper functions whenever min_free_kbytes
5467 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
5468 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5470 proc_dointvec(table
, write
, buffer
, length
, ppos
);
5472 setup_per_zone_wmarks();
5477 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
5478 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5483 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5488 zone
->min_unmapped_pages
= (zone
->managed_pages
*
5489 sysctl_min_unmapped_ratio
) / 100;
5493 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
5494 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5499 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5504 zone
->min_slab_pages
= (zone
->managed_pages
*
5505 sysctl_min_slab_ratio
) / 100;
5511 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5512 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5513 * whenever sysctl_lowmem_reserve_ratio changes.
5515 * The reserve ratio obviously has absolutely no relation with the
5516 * minimum watermarks. The lowmem reserve ratio can only make sense
5517 * if in function of the boot time zone sizes.
5519 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
5520 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5522 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5523 setup_per_zone_lowmem_reserve();
5528 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5529 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
5530 * can have before it gets flushed back to buddy allocator.
5533 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
5534 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5540 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5541 if (!write
|| (ret
< 0))
5543 for_each_populated_zone(zone
) {
5544 for_each_possible_cpu(cpu
) {
5546 high
= zone
->managed_pages
/ percpu_pagelist_fraction
;
5547 setup_pagelist_highmark(
5548 per_cpu_ptr(zone
->pageset
, cpu
), high
);
5554 int hashdist
= HASHDIST_DEFAULT
;
5557 static int __init
set_hashdist(char *str
)
5561 hashdist
= simple_strtoul(str
, &str
, 0);
5564 __setup("hashdist=", set_hashdist
);
5568 * allocate a large system hash table from bootmem
5569 * - it is assumed that the hash table must contain an exact power-of-2
5570 * quantity of entries
5571 * - limit is the number of hash buckets, not the total allocation size
5573 void *__init
alloc_large_system_hash(const char *tablename
,
5574 unsigned long bucketsize
,
5575 unsigned long numentries
,
5578 unsigned int *_hash_shift
,
5579 unsigned int *_hash_mask
,
5580 unsigned long low_limit
,
5581 unsigned long high_limit
)
5583 unsigned long long max
= high_limit
;
5584 unsigned long log2qty
, size
;
5587 /* allow the kernel cmdline to have a say */
5589 /* round applicable memory size up to nearest megabyte */
5590 numentries
= nr_kernel_pages
;
5591 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
5592 numentries
>>= 20 - PAGE_SHIFT
;
5593 numentries
<<= 20 - PAGE_SHIFT
;
5595 /* limit to 1 bucket per 2^scale bytes of low memory */
5596 if (scale
> PAGE_SHIFT
)
5597 numentries
>>= (scale
- PAGE_SHIFT
);
5599 numentries
<<= (PAGE_SHIFT
- scale
);
5601 /* Make sure we've got at least a 0-order allocation.. */
5602 if (unlikely(flags
& HASH_SMALL
)) {
5603 /* Makes no sense without HASH_EARLY */
5604 WARN_ON(!(flags
& HASH_EARLY
));
5605 if (!(numentries
>> *_hash_shift
)) {
5606 numentries
= 1UL << *_hash_shift
;
5607 BUG_ON(!numentries
);
5609 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
5610 numentries
= PAGE_SIZE
/ bucketsize
;
5612 numentries
= roundup_pow_of_two(numentries
);
5614 /* limit allocation size to 1/16 total memory by default */
5616 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
5617 do_div(max
, bucketsize
);
5619 max
= min(max
, 0x80000000ULL
);
5621 if (numentries
< low_limit
)
5622 numentries
= low_limit
;
5623 if (numentries
> max
)
5626 log2qty
= ilog2(numentries
);
5629 size
= bucketsize
<< log2qty
;
5630 if (flags
& HASH_EARLY
)
5631 table
= alloc_bootmem_nopanic(size
);
5633 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
5636 * If bucketsize is not a power-of-two, we may free
5637 * some pages at the end of hash table which
5638 * alloc_pages_exact() automatically does
5640 if (get_order(size
) < MAX_ORDER
) {
5641 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
5642 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
5645 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
5648 panic("Failed to allocate %s hash table\n", tablename
);
5650 printk(KERN_INFO
"%s hash table entries: %ld (order: %d, %lu bytes)\n",
5653 ilog2(size
) - PAGE_SHIFT
,
5657 *_hash_shift
= log2qty
;
5659 *_hash_mask
= (1 << log2qty
) - 1;
5664 /* Return a pointer to the bitmap storing bits affecting a block of pages */
5665 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
5668 #ifdef CONFIG_SPARSEMEM
5669 return __pfn_to_section(pfn
)->pageblock_flags
;
5671 return zone
->pageblock_flags
;
5672 #endif /* CONFIG_SPARSEMEM */
5675 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
5677 #ifdef CONFIG_SPARSEMEM
5678 pfn
&= (PAGES_PER_SECTION
-1);
5679 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5681 pfn
= pfn
- round_down(zone
->zone_start_pfn
, pageblock_nr_pages
);
5682 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5683 #endif /* CONFIG_SPARSEMEM */
5687 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5688 * @page: The page within the block of interest
5689 * @start_bitidx: The first bit of interest to retrieve
5690 * @end_bitidx: The last bit of interest
5691 * returns pageblock_bits flags
5693 unsigned long get_pageblock_flags_group(struct page
*page
,
5694 int start_bitidx
, int end_bitidx
)
5697 unsigned long *bitmap
;
5698 unsigned long pfn
, bitidx
;
5699 unsigned long flags
= 0;
5700 unsigned long value
= 1;
5702 zone
= page_zone(page
);
5703 pfn
= page_to_pfn(page
);
5704 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5705 bitidx
= pfn_to_bitidx(zone
, pfn
);
5707 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5708 if (test_bit(bitidx
+ start_bitidx
, bitmap
))
5715 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5716 * @page: The page within the block of interest
5717 * @start_bitidx: The first bit of interest
5718 * @end_bitidx: The last bit of interest
5719 * @flags: The flags to set
5721 void set_pageblock_flags_group(struct page
*page
, unsigned long flags
,
5722 int start_bitidx
, int end_bitidx
)
5725 unsigned long *bitmap
;
5726 unsigned long pfn
, bitidx
;
5727 unsigned long value
= 1;
5729 zone
= page_zone(page
);
5730 pfn
= page_to_pfn(page
);
5731 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5732 bitidx
= pfn_to_bitidx(zone
, pfn
);
5733 VM_BUG_ON(!zone_spans_pfn(zone
, pfn
));
5735 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5737 __set_bit(bitidx
+ start_bitidx
, bitmap
);
5739 __clear_bit(bitidx
+ start_bitidx
, bitmap
);
5743 * This function checks whether pageblock includes unmovable pages or not.
5744 * If @count is not zero, it is okay to include less @count unmovable pages
5746 * PageLRU check wihtout isolation or lru_lock could race so that
5747 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
5748 * expect this function should be exact.
5750 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
5751 bool skip_hwpoisoned_pages
)
5753 unsigned long pfn
, iter
, found
;
5757 * For avoiding noise data, lru_add_drain_all() should be called
5758 * If ZONE_MOVABLE, the zone never contains unmovable pages
5760 if (zone_idx(zone
) == ZONE_MOVABLE
)
5762 mt
= get_pageblock_migratetype(page
);
5763 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
5766 pfn
= page_to_pfn(page
);
5767 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
5768 unsigned long check
= pfn
+ iter
;
5770 if (!pfn_valid_within(check
))
5773 page
= pfn_to_page(check
);
5775 * We can't use page_count without pin a page
5776 * because another CPU can free compound page.
5777 * This check already skips compound tails of THP
5778 * because their page->_count is zero at all time.
5780 if (!atomic_read(&page
->_count
)) {
5781 if (PageBuddy(page
))
5782 iter
+= (1 << page_order(page
)) - 1;
5787 * The HWPoisoned page may be not in buddy system, and
5788 * page_count() is not 0.
5790 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
5796 * If there are RECLAIMABLE pages, we need to check it.
5797 * But now, memory offline itself doesn't call shrink_slab()
5798 * and it still to be fixed.
5801 * If the page is not RAM, page_count()should be 0.
5802 * we don't need more check. This is an _used_ not-movable page.
5804 * The problematic thing here is PG_reserved pages. PG_reserved
5805 * is set to both of a memory hole page and a _used_ kernel
5814 bool is_pageblock_removable_nolock(struct page
*page
)
5820 * We have to be careful here because we are iterating over memory
5821 * sections which are not zone aware so we might end up outside of
5822 * the zone but still within the section.
5823 * We have to take care about the node as well. If the node is offline
5824 * its NODE_DATA will be NULL - see page_zone.
5826 if (!node_online(page_to_nid(page
)))
5829 zone
= page_zone(page
);
5830 pfn
= page_to_pfn(page
);
5831 if (!zone_spans_pfn(zone
, pfn
))
5834 return !has_unmovable_pages(zone
, page
, 0, true);
5839 static unsigned long pfn_max_align_down(unsigned long pfn
)
5841 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
5842 pageblock_nr_pages
) - 1);
5845 static unsigned long pfn_max_align_up(unsigned long pfn
)
5847 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
5848 pageblock_nr_pages
));
5851 /* [start, end) must belong to a single zone. */
5852 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
5853 unsigned long start
, unsigned long end
)
5855 /* This function is based on compact_zone() from compaction.c. */
5856 unsigned long nr_reclaimed
;
5857 unsigned long pfn
= start
;
5858 unsigned int tries
= 0;
5863 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
5864 if (fatal_signal_pending(current
)) {
5869 if (list_empty(&cc
->migratepages
)) {
5870 cc
->nr_migratepages
= 0;
5871 pfn
= isolate_migratepages_range(cc
->zone
, cc
,
5878 } else if (++tries
== 5) {
5879 ret
= ret
< 0 ? ret
: -EBUSY
;
5883 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
5885 cc
->nr_migratepages
-= nr_reclaimed
;
5887 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
5888 0, MIGRATE_SYNC
, MR_CMA
);
5891 putback_movable_pages(&cc
->migratepages
);
5898 * alloc_contig_range() -- tries to allocate given range of pages
5899 * @start: start PFN to allocate
5900 * @end: one-past-the-last PFN to allocate
5901 * @migratetype: migratetype of the underlaying pageblocks (either
5902 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
5903 * in range must have the same migratetype and it must
5904 * be either of the two.
5906 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
5907 * aligned, however it's the caller's responsibility to guarantee that
5908 * we are the only thread that changes migrate type of pageblocks the
5911 * The PFN range must belong to a single zone.
5913 * Returns zero on success or negative error code. On success all
5914 * pages which PFN is in [start, end) are allocated for the caller and
5915 * need to be freed with free_contig_range().
5917 int alloc_contig_range(unsigned long start
, unsigned long end
,
5918 unsigned migratetype
)
5920 unsigned long outer_start
, outer_end
;
5923 struct compact_control cc
= {
5924 .nr_migratepages
= 0,
5926 .zone
= page_zone(pfn_to_page(start
)),
5928 .ignore_skip_hint
= true,
5930 INIT_LIST_HEAD(&cc
.migratepages
);
5933 * What we do here is we mark all pageblocks in range as
5934 * MIGRATE_ISOLATE. Because pageblock and max order pages may
5935 * have different sizes, and due to the way page allocator
5936 * work, we align the range to biggest of the two pages so
5937 * that page allocator won't try to merge buddies from
5938 * different pageblocks and change MIGRATE_ISOLATE to some
5939 * other migration type.
5941 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
5942 * migrate the pages from an unaligned range (ie. pages that
5943 * we are interested in). This will put all the pages in
5944 * range back to page allocator as MIGRATE_ISOLATE.
5946 * When this is done, we take the pages in range from page
5947 * allocator removing them from the buddy system. This way
5948 * page allocator will never consider using them.
5950 * This lets us mark the pageblocks back as
5951 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
5952 * aligned range but not in the unaligned, original range are
5953 * put back to page allocator so that buddy can use them.
5956 ret
= start_isolate_page_range(pfn_max_align_down(start
),
5957 pfn_max_align_up(end
), migratetype
,
5962 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
5967 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
5968 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
5969 * more, all pages in [start, end) are free in page allocator.
5970 * What we are going to do is to allocate all pages from
5971 * [start, end) (that is remove them from page allocator).
5973 * The only problem is that pages at the beginning and at the
5974 * end of interesting range may be not aligned with pages that
5975 * page allocator holds, ie. they can be part of higher order
5976 * pages. Because of this, we reserve the bigger range and
5977 * once this is done free the pages we are not interested in.
5979 * We don't have to hold zone->lock here because the pages are
5980 * isolated thus they won't get removed from buddy.
5983 lru_add_drain_all();
5987 outer_start
= start
;
5988 while (!PageBuddy(pfn_to_page(outer_start
))) {
5989 if (++order
>= MAX_ORDER
) {
5993 outer_start
&= ~0UL << order
;
5996 /* Make sure the range is really isolated. */
5997 if (test_pages_isolated(outer_start
, end
, false)) {
5998 pr_warn("alloc_contig_range test_pages_isolated(%lx, %lx) failed\n",
6005 /* Grab isolated pages from freelists. */
6006 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
6012 /* Free head and tail (if any) */
6013 if (start
!= outer_start
)
6014 free_contig_range(outer_start
, start
- outer_start
);
6015 if (end
!= outer_end
)
6016 free_contig_range(end
, outer_end
- end
);
6019 undo_isolate_page_range(pfn_max_align_down(start
),
6020 pfn_max_align_up(end
), migratetype
);
6024 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
6026 unsigned int count
= 0;
6028 for (; nr_pages
--; pfn
++) {
6029 struct page
*page
= pfn_to_page(pfn
);
6031 count
+= page_count(page
) != 1;
6034 WARN(count
!= 0, "%d pages are still in use!\n", count
);
6038 #ifdef CONFIG_MEMORY_HOTPLUG
6039 static int __meminit
__zone_pcp_update(void *data
)
6041 struct zone
*zone
= data
;
6043 unsigned long batch
= zone_batchsize(zone
), flags
;
6045 for_each_possible_cpu(cpu
) {
6046 struct per_cpu_pageset
*pset
;
6047 struct per_cpu_pages
*pcp
;
6049 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
6052 local_irq_save(flags
);
6054 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
6055 drain_zonestat(zone
, pset
);
6056 setup_pageset(pset
, batch
);
6057 local_irq_restore(flags
);
6062 void __meminit
zone_pcp_update(struct zone
*zone
)
6064 stop_machine(__zone_pcp_update
, zone
, NULL
);
6068 void zone_pcp_reset(struct zone
*zone
)
6070 unsigned long flags
;
6072 struct per_cpu_pageset
*pset
;
6074 /* avoid races with drain_pages() */
6075 local_irq_save(flags
);
6076 if (zone
->pageset
!= &boot_pageset
) {
6077 for_each_online_cpu(cpu
) {
6078 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
6079 drain_zonestat(zone
, pset
);
6081 free_percpu(zone
->pageset
);
6082 zone
->pageset
= &boot_pageset
;
6084 local_irq_restore(flags
);
6087 #ifdef CONFIG_MEMORY_HOTREMOVE
6089 * All pages in the range must be isolated before calling this.
6092 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
6098 unsigned long flags
;
6099 /* find the first valid pfn */
6100 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
6105 zone
= page_zone(pfn_to_page(pfn
));
6106 spin_lock_irqsave(&zone
->lock
, flags
);
6108 while (pfn
< end_pfn
) {
6109 if (!pfn_valid(pfn
)) {
6113 page
= pfn_to_page(pfn
);
6115 * The HWPoisoned page may be not in buddy system, and
6116 * page_count() is not 0.
6118 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
6120 SetPageReserved(page
);
6124 BUG_ON(page_count(page
));
6125 BUG_ON(!PageBuddy(page
));
6126 order
= page_order(page
);
6127 #ifdef CONFIG_DEBUG_VM
6128 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
6129 pfn
, 1 << order
, end_pfn
);
6131 list_del(&page
->lru
);
6132 rmv_page_order(page
);
6133 zone
->free_area
[order
].nr_free
--;
6134 for (i
= 0; i
< (1 << order
); i
++)
6135 SetPageReserved((page
+i
));
6136 pfn
+= (1 << order
);
6138 spin_unlock_irqrestore(&zone
->lock
, flags
);
6142 #ifdef CONFIG_MEMORY_FAILURE
6143 bool is_free_buddy_page(struct page
*page
)
6145 struct zone
*zone
= page_zone(page
);
6146 unsigned long pfn
= page_to_pfn(page
);
6147 unsigned long flags
;
6150 spin_lock_irqsave(&zone
->lock
, flags
);
6151 for (order
= 0; order
< MAX_ORDER
; order
++) {
6152 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
6154 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
6157 spin_unlock_irqrestore(&zone
->lock
, flags
);
6159 return order
< MAX_ORDER
;
6163 static const struct trace_print_flags pageflag_names
[] = {
6164 {1UL << PG_locked
, "locked" },
6165 {1UL << PG_error
, "error" },
6166 {1UL << PG_referenced
, "referenced" },
6167 {1UL << PG_uptodate
, "uptodate" },
6168 {1UL << PG_dirty
, "dirty" },
6169 {1UL << PG_lru
, "lru" },
6170 {1UL << PG_active
, "active" },
6171 {1UL << PG_slab
, "slab" },
6172 {1UL << PG_owner_priv_1
, "owner_priv_1" },
6173 {1UL << PG_arch_1
, "arch_1" },
6174 {1UL << PG_reserved
, "reserved" },
6175 {1UL << PG_private
, "private" },
6176 {1UL << PG_private_2
, "private_2" },
6177 {1UL << PG_writeback
, "writeback" },
6178 #ifdef CONFIG_PAGEFLAGS_EXTENDED
6179 {1UL << PG_head
, "head" },
6180 {1UL << PG_tail
, "tail" },
6182 {1UL << PG_compound
, "compound" },
6184 {1UL << PG_swapcache
, "swapcache" },
6185 {1UL << PG_mappedtodisk
, "mappedtodisk" },
6186 {1UL << PG_reclaim
, "reclaim" },
6187 {1UL << PG_swapbacked
, "swapbacked" },
6188 {1UL << PG_unevictable
, "unevictable" },
6190 {1UL << PG_mlocked
, "mlocked" },
6192 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
6193 {1UL << PG_uncached
, "uncached" },
6195 #ifdef CONFIG_MEMORY_FAILURE
6196 {1UL << PG_hwpoison
, "hwpoison" },
6198 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6199 {1UL << PG_compound_lock
, "compound_lock" },
6203 static void dump_page_flags(unsigned long flags
)
6205 const char *delim
= "";
6209 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names
) != __NR_PAGEFLAGS
);
6211 printk(KERN_ALERT
"page flags: %#lx(", flags
);
6213 /* remove zone id */
6214 flags
&= (1UL << NR_PAGEFLAGS
) - 1;
6216 for (i
= 0; i
< ARRAY_SIZE(pageflag_names
) && flags
; i
++) {
6218 mask
= pageflag_names
[i
].mask
;
6219 if ((flags
& mask
) != mask
)
6223 printk("%s%s", delim
, pageflag_names
[i
].name
);
6227 /* check for left over flags */
6229 printk("%s%#lx", delim
, flags
);
6234 void dump_page(struct page
*page
)
6237 "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
6238 page
, atomic_read(&page
->_count
), page_mapcount(page
),
6239 page
->mapping
, page
->index
);
6240 dump_page_flags(page
->flags
);
6241 mem_cgroup_print_bad_page(page
);