2 * linux/mm/page_alloc.c
4 * Manages the free list, the system allocates free pages here.
5 * Note that kmalloc() lives in slab.c
7 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
8 * Swap reorganised 29.12.95, Stephen Tweedie
9 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
10 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
11 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
12 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000
13 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
14 * (lots of bits borrowed from Ingo Molnar & Andrew Morton)
17 #include <linux/stddef.h>
19 #include <linux/swap.h>
20 #include <linux/interrupt.h>
21 #include <linux/pagemap.h>
22 #include <linux/jiffies.h>
23 #include <linux/bootmem.h>
24 #include <linux/memblock.h>
25 #include <linux/compiler.h>
26 #include <linux/kernel.h>
27 #include <linux/kmemcheck.h>
28 #include <linux/module.h>
29 #include <linux/suspend.h>
30 #include <linux/pagevec.h>
31 #include <linux/blkdev.h>
32 #include <linux/slab.h>
33 #include <linux/ratelimit.h>
34 #include <linux/oom.h>
35 #include <linux/notifier.h>
36 #include <linux/topology.h>
37 #include <linux/sysctl.h>
38 #include <linux/cpu.h>
39 #include <linux/cpuset.h>
40 #include <linux/memory_hotplug.h>
41 #include <linux/nodemask.h>
42 #include <linux/vmalloc.h>
43 #include <linux/vmstat.h>
44 #include <linux/mempolicy.h>
45 #include <linux/stop_machine.h>
46 #include <linux/sort.h>
47 #include <linux/pfn.h>
48 #include <linux/backing-dev.h>
49 #include <linux/fault-inject.h>
50 #include <linux/page-isolation.h>
51 #include <linux/page_cgroup.h>
52 #include <linux/debugobjects.h>
53 #include <linux/kmemleak.h>
54 #include <linux/compaction.h>
55 #include <trace/events/kmem.h>
56 #include <linux/ftrace_event.h>
57 #include <linux/memcontrol.h>
58 #include <linux/prefetch.h>
59 #include <linux/migrate.h>
60 #include <linux/page-debug-flags.h>
62 #include <asm/tlbflush.h>
63 #include <asm/div64.h>
66 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
67 DEFINE_PER_CPU(int, numa_node
);
68 EXPORT_PER_CPU_SYMBOL(numa_node
);
71 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
73 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
74 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
75 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
76 * defined in <linux/topology.h>.
78 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
79 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
83 * Array of node states.
85 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
86 [N_POSSIBLE
] = NODE_MASK_ALL
,
87 [N_ONLINE
] = { { [0] = 1UL } },
89 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
91 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
93 #ifdef CONFIG_MOVABLE_NODE
94 [N_MEMORY
] = { { [0] = 1UL } },
96 [N_CPU
] = { { [0] = 1UL } },
99 EXPORT_SYMBOL(node_states
);
101 unsigned long totalram_pages __read_mostly
;
102 unsigned long totalreserve_pages __read_mostly
;
104 * When calculating the number of globally allowed dirty pages, there
105 * is a certain number of per-zone reserves that should not be
106 * considered dirtyable memory. This is the sum of those reserves
107 * over all existing zones that contribute dirtyable memory.
109 unsigned long dirty_balance_reserve __read_mostly
;
111 int percpu_pagelist_fraction
;
112 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
114 #ifdef CONFIG_PM_SLEEP
116 * The following functions are used by the suspend/hibernate code to temporarily
117 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
118 * while devices are suspended. To avoid races with the suspend/hibernate code,
119 * they should always be called with pm_mutex held (gfp_allowed_mask also should
120 * only be modified with pm_mutex held, unless the suspend/hibernate code is
121 * guaranteed not to run in parallel with that modification).
124 static gfp_t saved_gfp_mask
;
126 void pm_restore_gfp_mask(void)
128 WARN_ON(!mutex_is_locked(&pm_mutex
));
129 if (saved_gfp_mask
) {
130 gfp_allowed_mask
= saved_gfp_mask
;
135 void pm_restrict_gfp_mask(void)
137 WARN_ON(!mutex_is_locked(&pm_mutex
));
138 WARN_ON(saved_gfp_mask
);
139 saved_gfp_mask
= gfp_allowed_mask
;
140 gfp_allowed_mask
&= ~GFP_IOFS
;
143 bool pm_suspended_storage(void)
145 if ((gfp_allowed_mask
& GFP_IOFS
) == GFP_IOFS
)
149 #endif /* CONFIG_PM_SLEEP */
151 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
152 int pageblock_order __read_mostly
;
155 static void __free_pages_ok(struct page
*page
, unsigned int order
);
158 * results with 256, 32 in the lowmem_reserve sysctl:
159 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
160 * 1G machine -> (16M dma, 784M normal, 224M high)
161 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
162 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
163 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
165 * TBD: should special case ZONE_DMA32 machines here - in those we normally
166 * don't need any ZONE_NORMAL reservation
168 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
169 #ifdef CONFIG_ZONE_DMA
172 #ifdef CONFIG_ZONE_DMA32
175 #ifdef CONFIG_HIGHMEM
181 EXPORT_SYMBOL(totalram_pages
);
183 static char * const zone_names
[MAX_NR_ZONES
] = {
184 #ifdef CONFIG_ZONE_DMA
187 #ifdef CONFIG_ZONE_DMA32
191 #ifdef CONFIG_HIGHMEM
197 int min_free_kbytes
= 1024;
199 static unsigned long __meminitdata nr_kernel_pages
;
200 static unsigned long __meminitdata nr_all_pages
;
201 static unsigned long __meminitdata dma_reserve
;
203 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
204 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
205 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
206 static unsigned long __initdata required_kernelcore
;
207 static unsigned long __initdata required_movablecore
;
208 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
210 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
212 EXPORT_SYMBOL(movable_zone
);
213 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
216 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
217 int nr_online_nodes __read_mostly
= 1;
218 EXPORT_SYMBOL(nr_node_ids
);
219 EXPORT_SYMBOL(nr_online_nodes
);
222 int page_group_by_mobility_disabled __read_mostly
;
224 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
227 if (unlikely(page_group_by_mobility_disabled
))
228 migratetype
= MIGRATE_UNMOVABLE
;
230 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
231 PB_migrate
, PB_migrate_end
);
234 bool oom_killer_disabled __read_mostly
;
236 #ifdef CONFIG_DEBUG_VM
237 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
241 unsigned long pfn
= page_to_pfn(page
);
244 seq
= zone_span_seqbegin(zone
);
245 if (pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
247 else if (pfn
< zone
->zone_start_pfn
)
249 } while (zone_span_seqretry(zone
, seq
));
254 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
256 if (!pfn_valid_within(page_to_pfn(page
)))
258 if (zone
!= page_zone(page
))
264 * Temporary debugging check for pages not lying within a given zone.
266 static int bad_range(struct zone
*zone
, struct page
*page
)
268 if (page_outside_zone_boundaries(zone
, page
))
270 if (!page_is_consistent(zone
, page
))
276 static inline int bad_range(struct zone
*zone
, struct page
*page
)
282 static void bad_page(struct page
*page
)
284 static unsigned long resume
;
285 static unsigned long nr_shown
;
286 static unsigned long nr_unshown
;
288 /* Don't complain about poisoned pages */
289 if (PageHWPoison(page
)) {
290 reset_page_mapcount(page
); /* remove PageBuddy */
295 * Allow a burst of 60 reports, then keep quiet for that minute;
296 * or allow a steady drip of one report per second.
298 if (nr_shown
== 60) {
299 if (time_before(jiffies
, resume
)) {
305 "BUG: Bad page state: %lu messages suppressed\n",
312 resume
= jiffies
+ 60 * HZ
;
314 printk(KERN_ALERT
"BUG: Bad page state in process %s pfn:%05lx\n",
315 current
->comm
, page_to_pfn(page
));
321 /* Leave bad fields for debug, except PageBuddy could make trouble */
322 reset_page_mapcount(page
); /* remove PageBuddy */
323 add_taint(TAINT_BAD_PAGE
);
327 * Higher-order pages are called "compound pages". They are structured thusly:
329 * The first PAGE_SIZE page is called the "head page".
331 * The remaining PAGE_SIZE pages are called "tail pages".
333 * All pages have PG_compound set. All tail pages have their ->first_page
334 * pointing at the head page.
336 * The first tail page's ->lru.next holds the address of the compound page's
337 * put_page() function. Its ->lru.prev holds the order of allocation.
338 * This usage means that zero-order pages may not be compound.
341 static void free_compound_page(struct page
*page
)
343 __free_pages_ok(page
, compound_order(page
));
346 void prep_compound_page(struct page
*page
, unsigned long order
)
349 int nr_pages
= 1 << order
;
351 set_compound_page_dtor(page
, free_compound_page
);
352 set_compound_order(page
, order
);
354 for (i
= 1; i
< nr_pages
; i
++) {
355 struct page
*p
= page
+ i
;
357 set_page_count(p
, 0);
358 p
->first_page
= page
;
362 /* update __split_huge_page_refcount if you change this function */
363 static int destroy_compound_page(struct page
*page
, unsigned long order
)
366 int nr_pages
= 1 << order
;
369 if (unlikely(compound_order(page
) != order
)) {
374 __ClearPageHead(page
);
376 for (i
= 1; i
< nr_pages
; i
++) {
377 struct page
*p
= page
+ i
;
379 if (unlikely(!PageTail(p
) || (p
->first_page
!= page
))) {
389 static inline void prep_zero_page(struct page
*page
, int order
, gfp_t gfp_flags
)
394 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
395 * and __GFP_HIGHMEM from hard or soft interrupt context.
397 VM_BUG_ON((gfp_flags
& __GFP_HIGHMEM
) && in_interrupt());
398 for (i
= 0; i
< (1 << order
); i
++)
399 clear_highpage(page
+ i
);
402 #ifdef CONFIG_DEBUG_PAGEALLOC
403 unsigned int _debug_guardpage_minorder
;
405 static int __init
debug_guardpage_minorder_setup(char *buf
)
409 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
410 printk(KERN_ERR
"Bad debug_guardpage_minorder value\n");
413 _debug_guardpage_minorder
= res
;
414 printk(KERN_INFO
"Setting debug_guardpage_minorder to %lu\n", res
);
417 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
419 static inline void set_page_guard_flag(struct page
*page
)
421 __set_bit(PAGE_DEBUG_FLAG_GUARD
, &page
->debug_flags
);
424 static inline void clear_page_guard_flag(struct page
*page
)
426 __clear_bit(PAGE_DEBUG_FLAG_GUARD
, &page
->debug_flags
);
429 static inline void set_page_guard_flag(struct page
*page
) { }
430 static inline void clear_page_guard_flag(struct page
*page
) { }
433 static inline void set_page_order(struct page
*page
, int order
)
435 set_page_private(page
, order
);
436 __SetPageBuddy(page
);
439 static inline void rmv_page_order(struct page
*page
)
441 __ClearPageBuddy(page
);
442 set_page_private(page
, 0);
446 * Locate the struct page for both the matching buddy in our
447 * pair (buddy1) and the combined O(n+1) page they form (page).
449 * 1) Any buddy B1 will have an order O twin B2 which satisfies
450 * the following equation:
452 * For example, if the starting buddy (buddy2) is #8 its order
454 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
456 * 2) Any buddy B will have an order O+1 parent P which
457 * satisfies the following equation:
460 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
462 static inline unsigned long
463 __find_buddy_index(unsigned long page_idx
, unsigned int order
)
465 return page_idx
^ (1 << order
);
469 * This function checks whether a page is free && is the buddy
470 * we can do coalesce a page and its buddy if
471 * (a) the buddy is not in a hole &&
472 * (b) the buddy is in the buddy system &&
473 * (c) a page and its buddy have the same order &&
474 * (d) a page and its buddy are in the same zone.
476 * For recording whether a page is in the buddy system, we set ->_mapcount -2.
477 * Setting, clearing, and testing _mapcount -2 is serialized by zone->lock.
479 * For recording page's order, we use page_private(page).
481 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
484 if (!pfn_valid_within(page_to_pfn(buddy
)))
487 if (page_zone_id(page
) != page_zone_id(buddy
))
490 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
491 VM_BUG_ON(page_count(buddy
) != 0);
495 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
496 VM_BUG_ON(page_count(buddy
) != 0);
503 * Freeing function for a buddy system allocator.
505 * The concept of a buddy system is to maintain direct-mapped table
506 * (containing bit values) for memory blocks of various "orders".
507 * The bottom level table contains the map for the smallest allocatable
508 * units of memory (here, pages), and each level above it describes
509 * pairs of units from the levels below, hence, "buddies".
510 * At a high level, all that happens here is marking the table entry
511 * at the bottom level available, and propagating the changes upward
512 * as necessary, plus some accounting needed to play nicely with other
513 * parts of the VM system.
514 * At each level, we keep a list of pages, which are heads of continuous
515 * free pages of length of (1 << order) and marked with _mapcount -2. Page's
516 * order is recorded in page_private(page) field.
517 * So when we are allocating or freeing one, we can derive the state of the
518 * other. That is, if we allocate a small block, and both were
519 * free, the remainder of the region must be split into blocks.
520 * If a block is freed, and its buddy is also free, then this
521 * triggers coalescing into a block of larger size.
526 static inline void __free_one_page(struct page
*page
,
527 struct zone
*zone
, unsigned int order
,
530 unsigned long page_idx
;
531 unsigned long combined_idx
;
532 unsigned long uninitialized_var(buddy_idx
);
535 if (unlikely(PageCompound(page
)))
536 if (unlikely(destroy_compound_page(page
, order
)))
539 VM_BUG_ON(migratetype
== -1);
541 page_idx
= page_to_pfn(page
) & ((1 << MAX_ORDER
) - 1);
543 VM_BUG_ON(page_idx
& ((1 << order
) - 1));
544 VM_BUG_ON(bad_range(zone
, page
));
546 while (order
< MAX_ORDER
-1) {
547 buddy_idx
= __find_buddy_index(page_idx
, order
);
548 buddy
= page
+ (buddy_idx
- page_idx
);
549 if (!page_is_buddy(page
, buddy
, order
))
552 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
553 * merge with it and move up one order.
555 if (page_is_guard(buddy
)) {
556 clear_page_guard_flag(buddy
);
557 set_page_private(page
, 0);
558 __mod_zone_freepage_state(zone
, 1 << order
,
561 list_del(&buddy
->lru
);
562 zone
->free_area
[order
].nr_free
--;
563 rmv_page_order(buddy
);
565 combined_idx
= buddy_idx
& page_idx
;
566 page
= page
+ (combined_idx
- page_idx
);
567 page_idx
= combined_idx
;
570 set_page_order(page
, order
);
573 * If this is not the largest possible page, check if the buddy
574 * of the next-highest order is free. If it is, it's possible
575 * that pages are being freed that will coalesce soon. In case,
576 * that is happening, add the free page to the tail of the list
577 * so it's less likely to be used soon and more likely to be merged
578 * as a higher order page
580 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
581 struct page
*higher_page
, *higher_buddy
;
582 combined_idx
= buddy_idx
& page_idx
;
583 higher_page
= page
+ (combined_idx
- page_idx
);
584 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
585 higher_buddy
= higher_page
+ (buddy_idx
- combined_idx
);
586 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
587 list_add_tail(&page
->lru
,
588 &zone
->free_area
[order
].free_list
[migratetype
]);
593 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
595 zone
->free_area
[order
].nr_free
++;
598 static inline int free_pages_check(struct page
*page
)
600 if (unlikely(page_mapcount(page
) |
601 (page
->mapping
!= NULL
) |
602 (atomic_read(&page
->_count
) != 0) |
603 (page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
) |
604 (mem_cgroup_bad_page_check(page
)))) {
608 reset_page_last_nid(page
);
609 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
610 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
615 * Frees a number of pages from the PCP lists
616 * Assumes all pages on list are in same zone, and of same order.
617 * count is the number of pages to free.
619 * If the zone was previously in an "all pages pinned" state then look to
620 * see if this freeing clears that state.
622 * And clear the zone's pages_scanned counter, to hold off the "all pages are
623 * pinned" detection logic.
625 static void free_pcppages_bulk(struct zone
*zone
, int count
,
626 struct per_cpu_pages
*pcp
)
632 spin_lock(&zone
->lock
);
633 zone
->all_unreclaimable
= 0;
634 zone
->pages_scanned
= 0;
638 struct list_head
*list
;
641 * Remove pages from lists in a round-robin fashion. A
642 * batch_free count is maintained that is incremented when an
643 * empty list is encountered. This is so more pages are freed
644 * off fuller lists instead of spinning excessively around empty
649 if (++migratetype
== MIGRATE_PCPTYPES
)
651 list
= &pcp
->lists
[migratetype
];
652 } while (list_empty(list
));
654 /* This is the only non-empty list. Free them all. */
655 if (batch_free
== MIGRATE_PCPTYPES
)
656 batch_free
= to_free
;
659 int mt
; /* migratetype of the to-be-freed page */
661 page
= list_entry(list
->prev
, struct page
, lru
);
662 /* must delete as __free_one_page list manipulates */
663 list_del(&page
->lru
);
664 mt
= get_freepage_migratetype(page
);
665 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
666 __free_one_page(page
, zone
, 0, mt
);
667 trace_mm_page_pcpu_drain(page
, 0, mt
);
668 if (likely(get_pageblock_migratetype(page
) != MIGRATE_ISOLATE
)) {
669 __mod_zone_page_state(zone
, NR_FREE_PAGES
, 1);
670 if (is_migrate_cma(mt
))
671 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
, 1);
673 } while (--to_free
&& --batch_free
&& !list_empty(list
));
675 spin_unlock(&zone
->lock
);
678 static void free_one_page(struct zone
*zone
, struct page
*page
, int order
,
681 spin_lock(&zone
->lock
);
682 zone
->all_unreclaimable
= 0;
683 zone
->pages_scanned
= 0;
685 __free_one_page(page
, zone
, order
, migratetype
);
686 if (unlikely(migratetype
!= MIGRATE_ISOLATE
))
687 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
688 spin_unlock(&zone
->lock
);
691 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
696 trace_mm_page_free(page
, order
);
697 kmemcheck_free_shadow(page
, order
);
700 page
->mapping
= NULL
;
701 for (i
= 0; i
< (1 << order
); i
++)
702 bad
+= free_pages_check(page
+ i
);
706 if (!PageHighMem(page
)) {
707 debug_check_no_locks_freed(page_address(page
),PAGE_SIZE
<<order
);
708 debug_check_no_obj_freed(page_address(page
),
711 arch_free_page(page
, order
);
712 kernel_map_pages(page
, 1 << order
, 0);
717 static void __free_pages_ok(struct page
*page
, unsigned int order
)
722 if (!free_pages_prepare(page
, order
))
725 local_irq_save(flags
);
726 __count_vm_events(PGFREE
, 1 << order
);
727 migratetype
= get_pageblock_migratetype(page
);
728 set_freepage_migratetype(page
, migratetype
);
729 free_one_page(page_zone(page
), page
, order
, migratetype
);
730 local_irq_restore(flags
);
734 * Read access to zone->managed_pages is safe because it's unsigned long,
735 * but we still need to serialize writers. Currently all callers of
736 * __free_pages_bootmem() except put_page_bootmem() should only be used
737 * at boot time. So for shorter boot time, we shift the burden to
738 * put_page_bootmem() to serialize writers.
740 void __meminit
__free_pages_bootmem(struct page
*page
, unsigned int order
)
742 unsigned int nr_pages
= 1 << order
;
746 for (loop
= 0; loop
< nr_pages
; loop
++) {
747 struct page
*p
= &page
[loop
];
749 if (loop
+ 1 < nr_pages
)
751 __ClearPageReserved(p
);
752 set_page_count(p
, 0);
755 page_zone(page
)->managed_pages
+= 1 << order
;
756 set_page_refcounted(page
);
757 __free_pages(page
, order
);
761 /* Free whole pageblock and set it's migration type to MIGRATE_CMA. */
762 void __init
init_cma_reserved_pageblock(struct page
*page
)
764 unsigned i
= pageblock_nr_pages
;
765 struct page
*p
= page
;
768 __ClearPageReserved(p
);
769 set_page_count(p
, 0);
772 set_page_refcounted(page
);
773 set_pageblock_migratetype(page
, MIGRATE_CMA
);
774 __free_pages(page
, pageblock_order
);
775 totalram_pages
+= pageblock_nr_pages
;
780 * The order of subdivision here is critical for the IO subsystem.
781 * Please do not alter this order without good reasons and regression
782 * testing. Specifically, as large blocks of memory are subdivided,
783 * the order in which smaller blocks are delivered depends on the order
784 * they're subdivided in this function. This is the primary factor
785 * influencing the order in which pages are delivered to the IO
786 * subsystem according to empirical testing, and this is also justified
787 * by considering the behavior of a buddy system containing a single
788 * large block of memory acted on by a series of small allocations.
789 * This behavior is a critical factor in sglist merging's success.
793 static inline void expand(struct zone
*zone
, struct page
*page
,
794 int low
, int high
, struct free_area
*area
,
797 unsigned long size
= 1 << high
;
803 VM_BUG_ON(bad_range(zone
, &page
[size
]));
805 #ifdef CONFIG_DEBUG_PAGEALLOC
806 if (high
< debug_guardpage_minorder()) {
808 * Mark as guard pages (or page), that will allow to
809 * merge back to allocator when buddy will be freed.
810 * Corresponding page table entries will not be touched,
811 * pages will stay not present in virtual address space
813 INIT_LIST_HEAD(&page
[size
].lru
);
814 set_page_guard_flag(&page
[size
]);
815 set_page_private(&page
[size
], high
);
816 /* Guard pages are not available for any usage */
817 __mod_zone_freepage_state(zone
, -(1 << high
),
822 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
824 set_page_order(&page
[size
], high
);
829 * This page is about to be returned from the page allocator
831 static inline int check_new_page(struct page
*page
)
833 if (unlikely(page_mapcount(page
) |
834 (page
->mapping
!= NULL
) |
835 (atomic_read(&page
->_count
) != 0) |
836 (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
) |
837 (mem_cgroup_bad_page_check(page
)))) {
844 static int prep_new_page(struct page
*page
, int order
, gfp_t gfp_flags
)
848 for (i
= 0; i
< (1 << order
); i
++) {
849 struct page
*p
= page
+ i
;
850 if (unlikely(check_new_page(p
)))
854 set_page_private(page
, 0);
855 set_page_refcounted(page
);
857 arch_alloc_page(page
, order
);
858 kernel_map_pages(page
, 1 << order
, 1);
860 if (gfp_flags
& __GFP_ZERO
)
861 prep_zero_page(page
, order
, gfp_flags
);
863 if (order
&& (gfp_flags
& __GFP_COMP
))
864 prep_compound_page(page
, order
);
870 * Go through the free lists for the given migratetype and remove
871 * the smallest available page from the freelists
874 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
877 unsigned int current_order
;
878 struct free_area
* area
;
881 /* Find a page of the appropriate size in the preferred list */
882 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
883 area
= &(zone
->free_area
[current_order
]);
884 if (list_empty(&area
->free_list
[migratetype
]))
887 page
= list_entry(area
->free_list
[migratetype
].next
,
889 list_del(&page
->lru
);
890 rmv_page_order(page
);
892 expand(zone
, page
, order
, current_order
, area
, migratetype
);
901 * This array describes the order lists are fallen back to when
902 * the free lists for the desirable migrate type are depleted
904 static int fallbacks
[MIGRATE_TYPES
][4] = {
905 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
906 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
908 [MIGRATE_MOVABLE
] = { MIGRATE_CMA
, MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
909 [MIGRATE_CMA
] = { MIGRATE_RESERVE
}, /* Never used */
911 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
913 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
}, /* Never used */
914 [MIGRATE_ISOLATE
] = { MIGRATE_RESERVE
}, /* Never used */
918 * Move the free pages in a range to the free lists of the requested type.
919 * Note that start_page and end_pages are not aligned on a pageblock
920 * boundary. If alignment is required, use move_freepages_block()
922 int move_freepages(struct zone
*zone
,
923 struct page
*start_page
, struct page
*end_page
,
930 #ifndef CONFIG_HOLES_IN_ZONE
932 * page_zone is not safe to call in this context when
933 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
934 * anyway as we check zone boundaries in move_freepages_block().
935 * Remove at a later date when no bug reports exist related to
936 * grouping pages by mobility
938 BUG_ON(page_zone(start_page
) != page_zone(end_page
));
941 for (page
= start_page
; page
<= end_page
;) {
942 /* Make sure we are not inadvertently changing nodes */
943 VM_BUG_ON(page_to_nid(page
) != zone_to_nid(zone
));
945 if (!pfn_valid_within(page_to_pfn(page
))) {
950 if (!PageBuddy(page
)) {
955 order
= page_order(page
);
956 list_move(&page
->lru
,
957 &zone
->free_area
[order
].free_list
[migratetype
]);
958 set_freepage_migratetype(page
, migratetype
);
960 pages_moved
+= 1 << order
;
966 int move_freepages_block(struct zone
*zone
, struct page
*page
,
969 unsigned long start_pfn
, end_pfn
;
970 struct page
*start_page
, *end_page
;
972 start_pfn
= page_to_pfn(page
);
973 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
974 start_page
= pfn_to_page(start_pfn
);
975 end_page
= start_page
+ pageblock_nr_pages
- 1;
976 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
978 /* Do not cross zone boundaries */
979 if (start_pfn
< zone
->zone_start_pfn
)
981 if (end_pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
)
984 return move_freepages(zone
, start_page
, end_page
, migratetype
);
987 static void change_pageblock_range(struct page
*pageblock_page
,
988 int start_order
, int migratetype
)
990 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
992 while (nr_pageblocks
--) {
993 set_pageblock_migratetype(pageblock_page
, migratetype
);
994 pageblock_page
+= pageblock_nr_pages
;
998 /* Remove an element from the buddy allocator from the fallback list */
999 static inline struct page
*
1000 __rmqueue_fallback(struct zone
*zone
, int order
, int start_migratetype
)
1002 struct free_area
* area
;
1007 /* Find the largest possible block of pages in the other list */
1008 for (current_order
= MAX_ORDER
-1; current_order
>= order
;
1011 migratetype
= fallbacks
[start_migratetype
][i
];
1013 /* MIGRATE_RESERVE handled later if necessary */
1014 if (migratetype
== MIGRATE_RESERVE
)
1017 area
= &(zone
->free_area
[current_order
]);
1018 if (list_empty(&area
->free_list
[migratetype
]))
1021 page
= list_entry(area
->free_list
[migratetype
].next
,
1026 * If breaking a large block of pages, move all free
1027 * pages to the preferred allocation list. If falling
1028 * back for a reclaimable kernel allocation, be more
1029 * aggressive about taking ownership of free pages
1031 * On the other hand, never change migration
1032 * type of MIGRATE_CMA pageblocks nor move CMA
1033 * pages on different free lists. We don't
1034 * want unmovable pages to be allocated from
1035 * MIGRATE_CMA areas.
1037 if (!is_migrate_cma(migratetype
) &&
1038 (unlikely(current_order
>= pageblock_order
/ 2) ||
1039 start_migratetype
== MIGRATE_RECLAIMABLE
||
1040 page_group_by_mobility_disabled
)) {
1042 pages
= move_freepages_block(zone
, page
,
1045 /* Claim the whole block if over half of it is free */
1046 if (pages
>= (1 << (pageblock_order
-1)) ||
1047 page_group_by_mobility_disabled
)
1048 set_pageblock_migratetype(page
,
1051 migratetype
= start_migratetype
;
1054 /* Remove the page from the freelists */
1055 list_del(&page
->lru
);
1056 rmv_page_order(page
);
1058 /* Take ownership for orders >= pageblock_order */
1059 if (current_order
>= pageblock_order
&&
1060 !is_migrate_cma(migratetype
))
1061 change_pageblock_range(page
, current_order
,
1064 expand(zone
, page
, order
, current_order
, area
,
1065 is_migrate_cma(migratetype
)
1066 ? migratetype
: start_migratetype
);
1068 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
1069 start_migratetype
, migratetype
);
1079 * Do the hard work of removing an element from the buddy allocator.
1080 * Call me with the zone->lock already held.
1082 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
1088 page
= __rmqueue_smallest(zone
, order
, migratetype
);
1090 if (unlikely(!page
) && migratetype
!= MIGRATE_RESERVE
) {
1091 page
= __rmqueue_fallback(zone
, order
, migratetype
);
1094 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1095 * is used because __rmqueue_smallest is an inline function
1096 * and we want just one call site
1099 migratetype
= MIGRATE_RESERVE
;
1104 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1109 * Obtain a specified number of elements from the buddy allocator, all under
1110 * a single hold of the lock, for efficiency. Add them to the supplied list.
1111 * Returns the number of new pages which were placed at *list.
1113 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1114 unsigned long count
, struct list_head
*list
,
1115 int migratetype
, int cold
)
1117 int mt
= migratetype
, i
;
1119 spin_lock(&zone
->lock
);
1120 for (i
= 0; i
< count
; ++i
) {
1121 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
1122 if (unlikely(page
== NULL
))
1126 * Split buddy pages returned by expand() are received here
1127 * in physical page order. The page is added to the callers and
1128 * list and the list head then moves forward. From the callers
1129 * perspective, the linked list is ordered by page number in
1130 * some conditions. This is useful for IO devices that can
1131 * merge IO requests if the physical pages are ordered
1134 if (likely(cold
== 0))
1135 list_add(&page
->lru
, list
);
1137 list_add_tail(&page
->lru
, list
);
1138 if (IS_ENABLED(CONFIG_CMA
)) {
1139 mt
= get_pageblock_migratetype(page
);
1140 if (!is_migrate_cma(mt
) && mt
!= MIGRATE_ISOLATE
)
1143 set_freepage_migratetype(page
, mt
);
1145 if (is_migrate_cma(mt
))
1146 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
1149 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
1150 spin_unlock(&zone
->lock
);
1156 * Called from the vmstat counter updater to drain pagesets of this
1157 * currently executing processor on remote nodes after they have
1160 * Note that this function must be called with the thread pinned to
1161 * a single processor.
1163 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
1165 unsigned long flags
;
1168 local_irq_save(flags
);
1169 if (pcp
->count
>= pcp
->batch
)
1170 to_drain
= pcp
->batch
;
1172 to_drain
= pcp
->count
;
1174 free_pcppages_bulk(zone
, to_drain
, pcp
);
1175 pcp
->count
-= to_drain
;
1177 local_irq_restore(flags
);
1182 * Drain pages of the indicated processor.
1184 * The processor must either be the current processor and the
1185 * thread pinned to the current processor or a processor that
1188 static void drain_pages(unsigned int cpu
)
1190 unsigned long flags
;
1193 for_each_populated_zone(zone
) {
1194 struct per_cpu_pageset
*pset
;
1195 struct per_cpu_pages
*pcp
;
1197 local_irq_save(flags
);
1198 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
1202 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1205 local_irq_restore(flags
);
1210 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1212 void drain_local_pages(void *arg
)
1214 drain_pages(smp_processor_id());
1218 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1220 * Note that this code is protected against sending an IPI to an offline
1221 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1222 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1223 * nothing keeps CPUs from showing up after we populated the cpumask and
1224 * before the call to on_each_cpu_mask().
1226 void drain_all_pages(void)
1229 struct per_cpu_pageset
*pcp
;
1233 * Allocate in the BSS so we wont require allocation in
1234 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1236 static cpumask_t cpus_with_pcps
;
1239 * We don't care about racing with CPU hotplug event
1240 * as offline notification will cause the notified
1241 * cpu to drain that CPU pcps and on_each_cpu_mask
1242 * disables preemption as part of its processing
1244 for_each_online_cpu(cpu
) {
1245 bool has_pcps
= false;
1246 for_each_populated_zone(zone
) {
1247 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
1248 if (pcp
->pcp
.count
) {
1254 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
1256 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
1258 on_each_cpu_mask(&cpus_with_pcps
, drain_local_pages
, NULL
, 1);
1261 #ifdef CONFIG_HIBERNATION
1263 void mark_free_pages(struct zone
*zone
)
1265 unsigned long pfn
, max_zone_pfn
;
1266 unsigned long flags
;
1268 struct list_head
*curr
;
1270 if (!zone
->spanned_pages
)
1273 spin_lock_irqsave(&zone
->lock
, flags
);
1275 max_zone_pfn
= zone
->zone_start_pfn
+ zone
->spanned_pages
;
1276 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1277 if (pfn_valid(pfn
)) {
1278 struct page
*page
= pfn_to_page(pfn
);
1280 if (!swsusp_page_is_forbidden(page
))
1281 swsusp_unset_page_free(page
);
1284 for_each_migratetype_order(order
, t
) {
1285 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
1288 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
1289 for (i
= 0; i
< (1UL << order
); i
++)
1290 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
1293 spin_unlock_irqrestore(&zone
->lock
, flags
);
1295 #endif /* CONFIG_PM */
1298 * Free a 0-order page
1299 * cold == 1 ? free a cold page : free a hot page
1301 void free_hot_cold_page(struct page
*page
, int cold
)
1303 struct zone
*zone
= page_zone(page
);
1304 struct per_cpu_pages
*pcp
;
1305 unsigned long flags
;
1308 if (!free_pages_prepare(page
, 0))
1311 migratetype
= get_pageblock_migratetype(page
);
1312 set_freepage_migratetype(page
, migratetype
);
1313 local_irq_save(flags
);
1314 __count_vm_event(PGFREE
);
1317 * We only track unmovable, reclaimable and movable on pcp lists.
1318 * Free ISOLATE pages back to the allocator because they are being
1319 * offlined but treat RESERVE as movable pages so we can get those
1320 * areas back if necessary. Otherwise, we may have to free
1321 * excessively into the page allocator
1323 if (migratetype
>= MIGRATE_PCPTYPES
) {
1324 if (unlikely(migratetype
== MIGRATE_ISOLATE
)) {
1325 free_one_page(zone
, page
, 0, migratetype
);
1328 migratetype
= MIGRATE_MOVABLE
;
1331 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1333 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
1335 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
1337 if (pcp
->count
>= pcp
->high
) {
1338 free_pcppages_bulk(zone
, pcp
->batch
, pcp
);
1339 pcp
->count
-= pcp
->batch
;
1343 local_irq_restore(flags
);
1347 * Free a list of 0-order pages
1349 void free_hot_cold_page_list(struct list_head
*list
, int cold
)
1351 struct page
*page
, *next
;
1353 list_for_each_entry_safe(page
, next
, list
, lru
) {
1354 trace_mm_page_free_batched(page
, cold
);
1355 free_hot_cold_page(page
, cold
);
1360 * split_page takes a non-compound higher-order page, and splits it into
1361 * n (1<<order) sub-pages: page[0..n]
1362 * Each sub-page must be freed individually.
1364 * Note: this is probably too low level an operation for use in drivers.
1365 * Please consult with lkml before using this in your driver.
1367 void split_page(struct page
*page
, unsigned int order
)
1371 VM_BUG_ON(PageCompound(page
));
1372 VM_BUG_ON(!page_count(page
));
1374 #ifdef CONFIG_KMEMCHECK
1376 * Split shadow pages too, because free(page[0]) would
1377 * otherwise free the whole shadow.
1379 if (kmemcheck_page_is_tracked(page
))
1380 split_page(virt_to_page(page
[0].shadow
), order
);
1383 for (i
= 1; i
< (1 << order
); i
++)
1384 set_page_refcounted(page
+ i
);
1387 static int __isolate_free_page(struct page
*page
, unsigned int order
)
1389 unsigned long watermark
;
1393 BUG_ON(!PageBuddy(page
));
1395 zone
= page_zone(page
);
1396 mt
= get_pageblock_migratetype(page
);
1398 if (mt
!= MIGRATE_ISOLATE
) {
1399 /* Obey watermarks as if the page was being allocated */
1400 watermark
= low_wmark_pages(zone
) + (1 << order
);
1401 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
1404 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
1407 /* Remove page from free list */
1408 list_del(&page
->lru
);
1409 zone
->free_area
[order
].nr_free
--;
1410 rmv_page_order(page
);
1412 /* Set the pageblock if the isolated page is at least a pageblock */
1413 if (order
>= pageblock_order
- 1) {
1414 struct page
*endpage
= page
+ (1 << order
) - 1;
1415 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
1416 int mt
= get_pageblock_migratetype(page
);
1417 if (mt
!= MIGRATE_ISOLATE
&& !is_migrate_cma(mt
))
1418 set_pageblock_migratetype(page
,
1423 return 1UL << order
;
1427 * Similar to split_page except the page is already free. As this is only
1428 * being used for migration, the migratetype of the block also changes.
1429 * As this is called with interrupts disabled, the caller is responsible
1430 * for calling arch_alloc_page() and kernel_map_page() after interrupts
1433 * Note: this is probably too low level an operation for use in drivers.
1434 * Please consult with lkml before using this in your driver.
1436 int split_free_page(struct page
*page
)
1441 order
= page_order(page
);
1443 nr_pages
= __isolate_free_page(page
, order
);
1447 /* Split into individual pages */
1448 set_page_refcounted(page
);
1449 split_page(page
, order
);
1454 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But
1455 * we cheat by calling it from here, in the order > 0 path. Saves a branch
1459 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
1460 struct zone
*zone
, int order
, gfp_t gfp_flags
,
1463 unsigned long flags
;
1465 int cold
= !!(gfp_flags
& __GFP_COLD
);
1468 if (likely(order
== 0)) {
1469 struct per_cpu_pages
*pcp
;
1470 struct list_head
*list
;
1472 local_irq_save(flags
);
1473 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1474 list
= &pcp
->lists
[migratetype
];
1475 if (list_empty(list
)) {
1476 pcp
->count
+= rmqueue_bulk(zone
, 0,
1479 if (unlikely(list_empty(list
)))
1484 page
= list_entry(list
->prev
, struct page
, lru
);
1486 page
= list_entry(list
->next
, struct page
, lru
);
1488 list_del(&page
->lru
);
1491 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
1493 * __GFP_NOFAIL is not to be used in new code.
1495 * All __GFP_NOFAIL callers should be fixed so that they
1496 * properly detect and handle allocation failures.
1498 * We most definitely don't want callers attempting to
1499 * allocate greater than order-1 page units with
1502 WARN_ON_ONCE(order
> 1);
1504 spin_lock_irqsave(&zone
->lock
, flags
);
1505 page
= __rmqueue(zone
, order
, migratetype
);
1506 spin_unlock(&zone
->lock
);
1509 __mod_zone_freepage_state(zone
, -(1 << order
),
1510 get_pageblock_migratetype(page
));
1513 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
1514 zone_statistics(preferred_zone
, zone
, gfp_flags
);
1515 local_irq_restore(flags
);
1517 VM_BUG_ON(bad_range(zone
, page
));
1518 if (prep_new_page(page
, order
, gfp_flags
))
1523 local_irq_restore(flags
);
1527 #ifdef CONFIG_FAIL_PAGE_ALLOC
1530 struct fault_attr attr
;
1532 u32 ignore_gfp_highmem
;
1533 u32 ignore_gfp_wait
;
1535 } fail_page_alloc
= {
1536 .attr
= FAULT_ATTR_INITIALIZER
,
1537 .ignore_gfp_wait
= 1,
1538 .ignore_gfp_highmem
= 1,
1542 static int __init
setup_fail_page_alloc(char *str
)
1544 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
1546 __setup("fail_page_alloc=", setup_fail_page_alloc
);
1548 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1550 if (order
< fail_page_alloc
.min_order
)
1552 if (gfp_mask
& __GFP_NOFAIL
)
1554 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
1556 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
1559 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
1562 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1564 static int __init
fail_page_alloc_debugfs(void)
1566 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
1569 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
1570 &fail_page_alloc
.attr
);
1572 return PTR_ERR(dir
);
1574 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
1575 &fail_page_alloc
.ignore_gfp_wait
))
1577 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
1578 &fail_page_alloc
.ignore_gfp_highmem
))
1580 if (!debugfs_create_u32("min-order", mode
, dir
,
1581 &fail_page_alloc
.min_order
))
1586 debugfs_remove_recursive(dir
);
1591 late_initcall(fail_page_alloc_debugfs
);
1593 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1595 #else /* CONFIG_FAIL_PAGE_ALLOC */
1597 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
1602 #endif /* CONFIG_FAIL_PAGE_ALLOC */
1605 * Return true if free pages are above 'mark'. This takes into account the order
1606 * of the allocation.
1608 static bool __zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1609 int classzone_idx
, int alloc_flags
, long free_pages
)
1611 /* free_pages my go negative - that's OK */
1613 long lowmem_reserve
= z
->lowmem_reserve
[classzone_idx
];
1616 free_pages
-= (1 << order
) - 1;
1617 if (alloc_flags
& ALLOC_HIGH
)
1619 if (alloc_flags
& ALLOC_HARDER
)
1622 /* If allocation can't use CMA areas don't use free CMA pages */
1623 if (!(alloc_flags
& ALLOC_CMA
))
1624 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
1626 if (free_pages
<= min
+ lowmem_reserve
)
1628 for (o
= 0; o
< order
; o
++) {
1629 /* At the next order, this order's pages become unavailable */
1630 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
1632 /* Require fewer higher order pages to be free */
1635 if (free_pages
<= min
)
1641 bool zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
1642 int classzone_idx
, int alloc_flags
)
1644 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1645 zone_page_state(z
, NR_FREE_PAGES
));
1648 bool zone_watermark_ok_safe(struct zone
*z
, int order
, unsigned long mark
,
1649 int classzone_idx
, int alloc_flags
)
1651 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
1653 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
1654 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
1656 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
1662 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
1663 * skip over zones that are not allowed by the cpuset, or that have
1664 * been recently (in last second) found to be nearly full. See further
1665 * comments in mmzone.h. Reduces cache footprint of zonelist scans
1666 * that have to skip over a lot of full or unallowed zones.
1668 * If the zonelist cache is present in the passed in zonelist, then
1669 * returns a pointer to the allowed node mask (either the current
1670 * tasks mems_allowed, or node_states[N_MEMORY].)
1672 * If the zonelist cache is not available for this zonelist, does
1673 * nothing and returns NULL.
1675 * If the fullzones BITMAP in the zonelist cache is stale (more than
1676 * a second since last zap'd) then we zap it out (clear its bits.)
1678 * We hold off even calling zlc_setup, until after we've checked the
1679 * first zone in the zonelist, on the theory that most allocations will
1680 * be satisfied from that first zone, so best to examine that zone as
1681 * quickly as we can.
1683 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1685 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1686 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
1688 zlc
= zonelist
->zlcache_ptr
;
1692 if (time_after(jiffies
, zlc
->last_full_zap
+ HZ
)) {
1693 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1694 zlc
->last_full_zap
= jiffies
;
1697 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
1698 &cpuset_current_mems_allowed
:
1699 &node_states
[N_MEMORY
];
1700 return allowednodes
;
1704 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1705 * if it is worth looking at further for free memory:
1706 * 1) Check that the zone isn't thought to be full (doesn't have its
1707 * bit set in the zonelist_cache fullzones BITMAP).
1708 * 2) Check that the zones node (obtained from the zonelist_cache
1709 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1710 * Return true (non-zero) if zone is worth looking at further, or
1711 * else return false (zero) if it is not.
1713 * This check -ignores- the distinction between various watermarks,
1714 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
1715 * found to be full for any variation of these watermarks, it will
1716 * be considered full for up to one second by all requests, unless
1717 * we are so low on memory on all allowed nodes that we are forced
1718 * into the second scan of the zonelist.
1720 * In the second scan we ignore this zonelist cache and exactly
1721 * apply the watermarks to all zones, even it is slower to do so.
1722 * We are low on memory in the second scan, and should leave no stone
1723 * unturned looking for a free page.
1725 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1726 nodemask_t
*allowednodes
)
1728 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1729 int i
; /* index of *z in zonelist zones */
1730 int n
; /* node that zone *z is on */
1732 zlc
= zonelist
->zlcache_ptr
;
1736 i
= z
- zonelist
->_zonerefs
;
1739 /* This zone is worth trying if it is allowed but not full */
1740 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
1744 * Given 'z' scanning a zonelist, set the corresponding bit in
1745 * zlc->fullzones, so that subsequent attempts to allocate a page
1746 * from that zone don't waste time re-examining it.
1748 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1750 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1751 int i
; /* index of *z in zonelist zones */
1753 zlc
= zonelist
->zlcache_ptr
;
1757 i
= z
- zonelist
->_zonerefs
;
1759 set_bit(i
, zlc
->fullzones
);
1763 * clear all zones full, called after direct reclaim makes progress so that
1764 * a zone that was recently full is not skipped over for up to a second
1766 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
1768 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
1770 zlc
= zonelist
->zlcache_ptr
;
1774 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
1777 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
1779 return node_isset(local_zone
->node
, zone
->zone_pgdat
->reclaim_nodes
);
1782 static void __paginginit
init_zone_allows_reclaim(int nid
)
1786 for_each_online_node(i
)
1787 if (node_distance(nid
, i
) <= RECLAIM_DISTANCE
)
1788 node_set(i
, NODE_DATA(nid
)->reclaim_nodes
);
1790 zone_reclaim_mode
= 1;
1793 #else /* CONFIG_NUMA */
1795 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
1800 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
1801 nodemask_t
*allowednodes
)
1806 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
1810 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
1814 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
1819 static inline void init_zone_allows_reclaim(int nid
)
1822 #endif /* CONFIG_NUMA */
1825 * get_page_from_freelist goes through the zonelist trying to allocate
1828 static struct page
*
1829 get_page_from_freelist(gfp_t gfp_mask
, nodemask_t
*nodemask
, unsigned int order
,
1830 struct zonelist
*zonelist
, int high_zoneidx
, int alloc_flags
,
1831 struct zone
*preferred_zone
, int migratetype
)
1834 struct page
*page
= NULL
;
1837 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
1838 int zlc_active
= 0; /* set if using zonelist_cache */
1839 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
1841 classzone_idx
= zone_idx(preferred_zone
);
1844 * Scan zonelist, looking for a zone with enough free.
1845 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1847 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
,
1848 high_zoneidx
, nodemask
) {
1849 if (IS_ENABLED(CONFIG_NUMA
) && zlc_active
&&
1850 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1852 if ((alloc_flags
& ALLOC_CPUSET
) &&
1853 !cpuset_zone_allowed_softwall(zone
, gfp_mask
))
1856 * When allocating a page cache page for writing, we
1857 * want to get it from a zone that is within its dirty
1858 * limit, such that no single zone holds more than its
1859 * proportional share of globally allowed dirty pages.
1860 * The dirty limits take into account the zone's
1861 * lowmem reserves and high watermark so that kswapd
1862 * should be able to balance it without having to
1863 * write pages from its LRU list.
1865 * This may look like it could increase pressure on
1866 * lower zones by failing allocations in higher zones
1867 * before they are full. But the pages that do spill
1868 * over are limited as the lower zones are protected
1869 * by this very same mechanism. It should not become
1870 * a practical burden to them.
1872 * XXX: For now, allow allocations to potentially
1873 * exceed the per-zone dirty limit in the slowpath
1874 * (ALLOC_WMARK_LOW unset) before going into reclaim,
1875 * which is important when on a NUMA setup the allowed
1876 * zones are together not big enough to reach the
1877 * global limit. The proper fix for these situations
1878 * will require awareness of zones in the
1879 * dirty-throttling and the flusher threads.
1881 if ((alloc_flags
& ALLOC_WMARK_LOW
) &&
1882 (gfp_mask
& __GFP_WRITE
) && !zone_dirty_ok(zone
))
1883 goto this_zone_full
;
1885 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
1886 if (!(alloc_flags
& ALLOC_NO_WATERMARKS
)) {
1890 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
1891 if (zone_watermark_ok(zone
, order
, mark
,
1892 classzone_idx
, alloc_flags
))
1895 if (IS_ENABLED(CONFIG_NUMA
) &&
1896 !did_zlc_setup
&& nr_online_nodes
> 1) {
1898 * we do zlc_setup if there are multiple nodes
1899 * and before considering the first zone allowed
1902 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
1907 if (zone_reclaim_mode
== 0 ||
1908 !zone_allows_reclaim(preferred_zone
, zone
))
1909 goto this_zone_full
;
1912 * As we may have just activated ZLC, check if the first
1913 * eligible zone has failed zone_reclaim recently.
1915 if (IS_ENABLED(CONFIG_NUMA
) && zlc_active
&&
1916 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
1919 ret
= zone_reclaim(zone
, gfp_mask
, order
);
1921 case ZONE_RECLAIM_NOSCAN
:
1924 case ZONE_RECLAIM_FULL
:
1925 /* scanned but unreclaimable */
1928 /* did we reclaim enough */
1929 if (!zone_watermark_ok(zone
, order
, mark
,
1930 classzone_idx
, alloc_flags
))
1931 goto this_zone_full
;
1936 page
= buffered_rmqueue(preferred_zone
, zone
, order
,
1937 gfp_mask
, migratetype
);
1941 if (IS_ENABLED(CONFIG_NUMA
))
1942 zlc_mark_zone_full(zonelist
, z
);
1945 if (unlikely(IS_ENABLED(CONFIG_NUMA
) && page
== NULL
&& zlc_active
)) {
1946 /* Disable zlc cache for second zonelist scan */
1953 * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was
1954 * necessary to allocate the page. The expectation is
1955 * that the caller is taking steps that will free more
1956 * memory. The caller should avoid the page being used
1957 * for !PFMEMALLOC purposes.
1959 page
->pfmemalloc
= !!(alloc_flags
& ALLOC_NO_WATERMARKS
);
1965 * Large machines with many possible nodes should not always dump per-node
1966 * meminfo in irq context.
1968 static inline bool should_suppress_show_mem(void)
1973 ret
= in_interrupt();
1978 static DEFINE_RATELIMIT_STATE(nopage_rs
,
1979 DEFAULT_RATELIMIT_INTERVAL
,
1980 DEFAULT_RATELIMIT_BURST
);
1982 void warn_alloc_failed(gfp_t gfp_mask
, int order
, const char *fmt
, ...)
1984 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
1986 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
1987 debug_guardpage_minorder() > 0)
1991 * This documents exceptions given to allocations in certain
1992 * contexts that are allowed to allocate outside current's set
1995 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
1996 if (test_thread_flag(TIF_MEMDIE
) ||
1997 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
1998 filter
&= ~SHOW_MEM_FILTER_NODES
;
1999 if (in_interrupt() || !(gfp_mask
& __GFP_WAIT
))
2000 filter
&= ~SHOW_MEM_FILTER_NODES
;
2003 struct va_format vaf
;
2006 va_start(args
, fmt
);
2011 pr_warn("%pV", &vaf
);
2016 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
2017 current
->comm
, order
, gfp_mask
);
2020 if (!should_suppress_show_mem())
2025 should_alloc_retry(gfp_t gfp_mask
, unsigned int order
,
2026 unsigned long did_some_progress
,
2027 unsigned long pages_reclaimed
)
2029 /* Do not loop if specifically requested */
2030 if (gfp_mask
& __GFP_NORETRY
)
2033 /* Always retry if specifically requested */
2034 if (gfp_mask
& __GFP_NOFAIL
)
2038 * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
2039 * making forward progress without invoking OOM. Suspend also disables
2040 * storage devices so kswapd will not help. Bail if we are suspending.
2042 if (!did_some_progress
&& pm_suspended_storage())
2046 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
2047 * means __GFP_NOFAIL, but that may not be true in other
2050 if (order
<= PAGE_ALLOC_COSTLY_ORDER
)
2054 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
2055 * specified, then we retry until we no longer reclaim any pages
2056 * (above), or we've reclaimed an order of pages at least as
2057 * large as the allocation's order. In both cases, if the
2058 * allocation still fails, we stop retrying.
2060 if (gfp_mask
& __GFP_REPEAT
&& pages_reclaimed
< (1 << order
))
2066 static inline struct page
*
2067 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
2068 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2069 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2074 /* Acquire the OOM killer lock for the zones in zonelist */
2075 if (!try_set_zonelist_oom(zonelist
, gfp_mask
)) {
2076 schedule_timeout_uninterruptible(1);
2081 * Go through the zonelist yet one more time, keep very high watermark
2082 * here, this is only to catch a parallel oom killing, we must fail if
2083 * we're still under heavy pressure.
2085 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
,
2086 order
, zonelist
, high_zoneidx
,
2087 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
,
2088 preferred_zone
, migratetype
);
2092 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2093 /* The OOM killer will not help higher order allocs */
2094 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2096 /* The OOM killer does not needlessly kill tasks for lowmem */
2097 if (high_zoneidx
< ZONE_NORMAL
)
2100 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
2101 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
2102 * The caller should handle page allocation failure by itself if
2103 * it specifies __GFP_THISNODE.
2104 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
2106 if (gfp_mask
& __GFP_THISNODE
)
2109 /* Exhausted what can be done so it's blamo time */
2110 out_of_memory(zonelist
, gfp_mask
, order
, nodemask
, false);
2113 clear_zonelist_oom(zonelist
, gfp_mask
);
2117 #ifdef CONFIG_COMPACTION
2118 /* Try memory compaction for high-order allocations before reclaim */
2119 static struct page
*
2120 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2121 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2122 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2123 int migratetype
, bool sync_migration
,
2124 bool *contended_compaction
, bool *deferred_compaction
,
2125 unsigned long *did_some_progress
)
2130 if (compaction_deferred(preferred_zone
, order
)) {
2131 *deferred_compaction
= true;
2135 current
->flags
|= PF_MEMALLOC
;
2136 *did_some_progress
= try_to_compact_pages(zonelist
, order
, gfp_mask
,
2137 nodemask
, sync_migration
,
2138 contended_compaction
);
2139 current
->flags
&= ~PF_MEMALLOC
;
2141 if (*did_some_progress
!= COMPACT_SKIPPED
) {
2144 /* Page migration frees to the PCP lists but we want merging */
2145 drain_pages(get_cpu());
2148 page
= get_page_from_freelist(gfp_mask
, nodemask
,
2149 order
, zonelist
, high_zoneidx
,
2150 alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2151 preferred_zone
, migratetype
);
2153 preferred_zone
->compact_blockskip_flush
= false;
2154 preferred_zone
->compact_considered
= 0;
2155 preferred_zone
->compact_defer_shift
= 0;
2156 if (order
>= preferred_zone
->compact_order_failed
)
2157 preferred_zone
->compact_order_failed
= order
+ 1;
2158 count_vm_event(COMPACTSUCCESS
);
2163 * It's bad if compaction run occurs and fails.
2164 * The most likely reason is that pages exist,
2165 * but not enough to satisfy watermarks.
2167 count_vm_event(COMPACTFAIL
);
2170 * As async compaction considers a subset of pageblocks, only
2171 * defer if the failure was a sync compaction failure.
2174 defer_compaction(preferred_zone
, order
);
2182 static inline struct page
*
2183 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2184 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2185 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2186 int migratetype
, bool sync_migration
,
2187 bool *contended_compaction
, bool *deferred_compaction
,
2188 unsigned long *did_some_progress
)
2192 #endif /* CONFIG_COMPACTION */
2194 /* Perform direct synchronous page reclaim */
2196 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
, struct zonelist
*zonelist
,
2197 nodemask_t
*nodemask
)
2199 struct reclaim_state reclaim_state
;
2204 /* We now go into synchronous reclaim */
2205 cpuset_memory_pressure_bump();
2206 current
->flags
|= PF_MEMALLOC
;
2207 lockdep_set_current_reclaim_state(gfp_mask
);
2208 reclaim_state
.reclaimed_slab
= 0;
2209 current
->reclaim_state
= &reclaim_state
;
2211 progress
= try_to_free_pages(zonelist
, order
, gfp_mask
, nodemask
);
2213 current
->reclaim_state
= NULL
;
2214 lockdep_clear_current_reclaim_state();
2215 current
->flags
&= ~PF_MEMALLOC
;
2222 /* The really slow allocator path where we enter direct reclaim */
2223 static inline struct page
*
2224 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
2225 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2226 nodemask_t
*nodemask
, int alloc_flags
, struct zone
*preferred_zone
,
2227 int migratetype
, unsigned long *did_some_progress
)
2229 struct page
*page
= NULL
;
2230 bool drained
= false;
2232 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, zonelist
,
2234 if (unlikely(!(*did_some_progress
)))
2237 /* After successful reclaim, reconsider all zones for allocation */
2238 if (IS_ENABLED(CONFIG_NUMA
))
2239 zlc_clear_zones_full(zonelist
);
2242 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
2243 zonelist
, high_zoneidx
,
2244 alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2245 preferred_zone
, migratetype
);
2248 * If an allocation failed after direct reclaim, it could be because
2249 * pages are pinned on the per-cpu lists. Drain them and try again
2251 if (!page
&& !drained
) {
2261 * This is called in the allocator slow-path if the allocation request is of
2262 * sufficient urgency to ignore watermarks and take other desperate measures
2264 static inline struct page
*
2265 __alloc_pages_high_priority(gfp_t gfp_mask
, unsigned int order
,
2266 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2267 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2273 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
,
2274 zonelist
, high_zoneidx
, ALLOC_NO_WATERMARKS
,
2275 preferred_zone
, migratetype
);
2277 if (!page
&& gfp_mask
& __GFP_NOFAIL
)
2278 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2279 } while (!page
&& (gfp_mask
& __GFP_NOFAIL
));
2285 void wake_all_kswapd(unsigned int order
, struct zonelist
*zonelist
,
2286 enum zone_type high_zoneidx
,
2287 enum zone_type classzone_idx
)
2292 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
)
2293 wakeup_kswapd(zone
, order
, classzone_idx
);
2297 gfp_to_alloc_flags(gfp_t gfp_mask
)
2299 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
2300 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2302 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2303 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
2306 * The caller may dip into page reserves a bit more if the caller
2307 * cannot run direct reclaim, or if the caller has realtime scheduling
2308 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2309 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
2311 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
2315 * Not worth trying to allocate harder for
2316 * __GFP_NOMEMALLOC even if it can't schedule.
2318 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2319 alloc_flags
|= ALLOC_HARDER
;
2321 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
2322 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
2324 alloc_flags
&= ~ALLOC_CPUSET
;
2325 } else if (unlikely(rt_task(current
)) && !in_interrupt())
2326 alloc_flags
|= ALLOC_HARDER
;
2328 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
2329 if (gfp_mask
& __GFP_MEMALLOC
)
2330 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2331 else if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
2332 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2333 else if (!in_interrupt() &&
2334 ((current
->flags
& PF_MEMALLOC
) ||
2335 unlikely(test_thread_flag(TIF_MEMDIE
))))
2336 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2339 if (allocflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
2340 alloc_flags
|= ALLOC_CMA
;
2345 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
2347 return !!(gfp_to_alloc_flags(gfp_mask
) & ALLOC_NO_WATERMARKS
);
2350 static inline struct page
*
2351 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
2352 struct zonelist
*zonelist
, enum zone_type high_zoneidx
,
2353 nodemask_t
*nodemask
, struct zone
*preferred_zone
,
2356 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2357 struct page
*page
= NULL
;
2359 unsigned long pages_reclaimed
= 0;
2360 unsigned long did_some_progress
;
2361 bool sync_migration
= false;
2362 bool deferred_compaction
= false;
2363 bool contended_compaction
= false;
2366 * In the slowpath, we sanity check order to avoid ever trying to
2367 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2368 * be using allocators in order of preference for an area that is
2371 if (order
>= MAX_ORDER
) {
2372 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
2377 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
2378 * __GFP_NOWARN set) should not cause reclaim since the subsystem
2379 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
2380 * using a larger set of nodes after it has established that the
2381 * allowed per node queues are empty and that nodes are
2384 if (IS_ENABLED(CONFIG_NUMA
) &&
2385 (gfp_mask
& GFP_THISNODE
) == GFP_THISNODE
)
2389 if (!(gfp_mask
& __GFP_NO_KSWAPD
))
2390 wake_all_kswapd(order
, zonelist
, high_zoneidx
,
2391 zone_idx(preferred_zone
));
2394 * OK, we're below the kswapd watermark and have kicked background
2395 * reclaim. Now things get more complex, so set up alloc_flags according
2396 * to how we want to proceed.
2398 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
2401 * Find the true preferred zone if the allocation is unconstrained by
2404 if (!(alloc_flags
& ALLOC_CPUSET
) && !nodemask
)
2405 first_zones_zonelist(zonelist
, high_zoneidx
, NULL
,
2409 /* This is the last chance, in general, before the goto nopage. */
2410 page
= get_page_from_freelist(gfp_mask
, nodemask
, order
, zonelist
,
2411 high_zoneidx
, alloc_flags
& ~ALLOC_NO_WATERMARKS
,
2412 preferred_zone
, migratetype
);
2416 /* Allocate without watermarks if the context allows */
2417 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
2419 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
2420 * the allocation is high priority and these type of
2421 * allocations are system rather than user orientated
2423 zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
2425 page
= __alloc_pages_high_priority(gfp_mask
, order
,
2426 zonelist
, high_zoneidx
, nodemask
,
2427 preferred_zone
, migratetype
);
2433 /* Atomic allocations - we can't balance anything */
2437 /* Avoid recursion of direct reclaim */
2438 if (current
->flags
& PF_MEMALLOC
)
2441 /* Avoid allocations with no watermarks from looping endlessly */
2442 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
2446 * Try direct compaction. The first pass is asynchronous. Subsequent
2447 * attempts after direct reclaim are synchronous
2449 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
2450 zonelist
, high_zoneidx
,
2452 alloc_flags
, preferred_zone
,
2453 migratetype
, sync_migration
,
2454 &contended_compaction
,
2455 &deferred_compaction
,
2456 &did_some_progress
);
2459 sync_migration
= true;
2462 * If compaction is deferred for high-order allocations, it is because
2463 * sync compaction recently failed. In this is the case and the caller
2464 * requested a movable allocation that does not heavily disrupt the
2465 * system then fail the allocation instead of entering direct reclaim.
2467 if ((deferred_compaction
|| contended_compaction
) &&
2468 (gfp_mask
& __GFP_NO_KSWAPD
))
2471 /* Try direct reclaim and then allocating */
2472 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
,
2473 zonelist
, high_zoneidx
,
2475 alloc_flags
, preferred_zone
,
2476 migratetype
, &did_some_progress
);
2481 * If we failed to make any progress reclaiming, then we are
2482 * running out of options and have to consider going OOM
2484 if (!did_some_progress
) {
2485 if ((gfp_mask
& __GFP_FS
) && !(gfp_mask
& __GFP_NORETRY
)) {
2486 if (oom_killer_disabled
)
2488 /* Coredumps can quickly deplete all memory reserves */
2489 if ((current
->flags
& PF_DUMPCORE
) &&
2490 !(gfp_mask
& __GFP_NOFAIL
))
2492 page
= __alloc_pages_may_oom(gfp_mask
, order
,
2493 zonelist
, high_zoneidx
,
2494 nodemask
, preferred_zone
,
2499 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2501 * The oom killer is not called for high-order
2502 * allocations that may fail, so if no progress
2503 * is being made, there are no other options and
2504 * retrying is unlikely to help.
2506 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2509 * The oom killer is not called for lowmem
2510 * allocations to prevent needlessly killing
2513 if (high_zoneidx
< ZONE_NORMAL
)
2521 /* Check if we should retry the allocation */
2522 pages_reclaimed
+= did_some_progress
;
2523 if (should_alloc_retry(gfp_mask
, order
, did_some_progress
,
2525 /* Wait for some write requests to complete then retry */
2526 wait_iff_congested(preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
2530 * High-order allocations do not necessarily loop after
2531 * direct reclaim and reclaim/compaction depends on compaction
2532 * being called after reclaim so call directly if necessary
2534 page
= __alloc_pages_direct_compact(gfp_mask
, order
,
2535 zonelist
, high_zoneidx
,
2537 alloc_flags
, preferred_zone
,
2538 migratetype
, sync_migration
,
2539 &contended_compaction
,
2540 &deferred_compaction
,
2541 &did_some_progress
);
2547 warn_alloc_failed(gfp_mask
, order
, NULL
);
2550 if (kmemcheck_enabled
)
2551 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
2557 * This is the 'heart' of the zoned buddy allocator.
2560 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
2561 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
2563 enum zone_type high_zoneidx
= gfp_zone(gfp_mask
);
2564 struct zone
*preferred_zone
;
2565 struct page
*page
= NULL
;
2566 int migratetype
= allocflags_to_migratetype(gfp_mask
);
2567 unsigned int cpuset_mems_cookie
;
2568 int alloc_flags
= ALLOC_WMARK_LOW
|ALLOC_CPUSET
;
2569 struct mem_cgroup
*memcg
= NULL
;
2571 gfp_mask
&= gfp_allowed_mask
;
2573 lockdep_trace_alloc(gfp_mask
);
2575 might_sleep_if(gfp_mask
& __GFP_WAIT
);
2577 if (should_fail_alloc_page(gfp_mask
, order
))
2581 * Check the zones suitable for the gfp_mask contain at least one
2582 * valid zone. It's possible to have an empty zonelist as a result
2583 * of GFP_THISNODE and a memoryless node
2585 if (unlikely(!zonelist
->_zonerefs
->zone
))
2589 * Will only have any effect when __GFP_KMEMCG is set. This is
2590 * verified in the (always inline) callee
2592 if (!memcg_kmem_newpage_charge(gfp_mask
, &memcg
, order
))
2596 cpuset_mems_cookie
= get_mems_allowed();
2598 /* The preferred zone is used for statistics later */
2599 first_zones_zonelist(zonelist
, high_zoneidx
,
2600 nodemask
? : &cpuset_current_mems_allowed
,
2602 if (!preferred_zone
)
2606 if (allocflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
2607 alloc_flags
|= ALLOC_CMA
;
2609 /* First allocation attempt */
2610 page
= get_page_from_freelist(gfp_mask
|__GFP_HARDWALL
, nodemask
, order
,
2611 zonelist
, high_zoneidx
, alloc_flags
,
2612 preferred_zone
, migratetype
);
2613 if (unlikely(!page
))
2614 page
= __alloc_pages_slowpath(gfp_mask
, order
,
2615 zonelist
, high_zoneidx
, nodemask
,
2616 preferred_zone
, migratetype
);
2618 trace_mm_page_alloc(page
, order
, gfp_mask
, migratetype
);
2622 * When updating a task's mems_allowed, it is possible to race with
2623 * parallel threads in such a way that an allocation can fail while
2624 * the mask is being updated. If a page allocation is about to fail,
2625 * check if the cpuset changed during allocation and if so, retry.
2627 if (unlikely(!put_mems_allowed(cpuset_mems_cookie
) && !page
))
2630 memcg_kmem_commit_charge(page
, memcg
, order
);
2634 EXPORT_SYMBOL(__alloc_pages_nodemask
);
2637 * Common helper functions.
2639 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
2644 * __get_free_pages() returns a 32-bit address, which cannot represent
2647 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
2649 page
= alloc_pages(gfp_mask
, order
);
2652 return (unsigned long) page_address(page
);
2654 EXPORT_SYMBOL(__get_free_pages
);
2656 unsigned long get_zeroed_page(gfp_t gfp_mask
)
2658 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
2660 EXPORT_SYMBOL(get_zeroed_page
);
2662 void __free_pages(struct page
*page
, unsigned int order
)
2664 if (put_page_testzero(page
)) {
2666 free_hot_cold_page(page
, 0);
2668 __free_pages_ok(page
, order
);
2672 EXPORT_SYMBOL(__free_pages
);
2674 void free_pages(unsigned long addr
, unsigned int order
)
2677 VM_BUG_ON(!virt_addr_valid((void *)addr
));
2678 __free_pages(virt_to_page((void *)addr
), order
);
2682 EXPORT_SYMBOL(free_pages
);
2685 * __free_memcg_kmem_pages and free_memcg_kmem_pages will free
2686 * pages allocated with __GFP_KMEMCG.
2688 * Those pages are accounted to a particular memcg, embedded in the
2689 * corresponding page_cgroup. To avoid adding a hit in the allocator to search
2690 * for that information only to find out that it is NULL for users who have no
2691 * interest in that whatsoever, we provide these functions.
2693 * The caller knows better which flags it relies on.
2695 void __free_memcg_kmem_pages(struct page
*page
, unsigned int order
)
2697 memcg_kmem_uncharge_pages(page
, order
);
2698 __free_pages(page
, order
);
2701 void free_memcg_kmem_pages(unsigned long addr
, unsigned int order
)
2704 VM_BUG_ON(!virt_addr_valid((void *)addr
));
2705 __free_memcg_kmem_pages(virt_to_page((void *)addr
), order
);
2709 static void *make_alloc_exact(unsigned long addr
, unsigned order
, size_t size
)
2712 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
2713 unsigned long used
= addr
+ PAGE_ALIGN(size
);
2715 split_page(virt_to_page((void *)addr
), order
);
2716 while (used
< alloc_end
) {
2721 return (void *)addr
;
2725 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
2726 * @size: the number of bytes to allocate
2727 * @gfp_mask: GFP flags for the allocation
2729 * This function is similar to alloc_pages(), except that it allocates the
2730 * minimum number of pages to satisfy the request. alloc_pages() can only
2731 * allocate memory in power-of-two pages.
2733 * This function is also limited by MAX_ORDER.
2735 * Memory allocated by this function must be released by free_pages_exact().
2737 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
2739 unsigned int order
= get_order(size
);
2742 addr
= __get_free_pages(gfp_mask
, order
);
2743 return make_alloc_exact(addr
, order
, size
);
2745 EXPORT_SYMBOL(alloc_pages_exact
);
2748 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
2750 * @nid: the preferred node ID where memory should be allocated
2751 * @size: the number of bytes to allocate
2752 * @gfp_mask: GFP flags for the allocation
2754 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
2756 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
2759 void *alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
2761 unsigned order
= get_order(size
);
2762 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
2765 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
2767 EXPORT_SYMBOL(alloc_pages_exact_nid
);
2770 * free_pages_exact - release memory allocated via alloc_pages_exact()
2771 * @virt: the value returned by alloc_pages_exact.
2772 * @size: size of allocation, same value as passed to alloc_pages_exact().
2774 * Release the memory allocated by a previous call to alloc_pages_exact.
2776 void free_pages_exact(void *virt
, size_t size
)
2778 unsigned long addr
= (unsigned long)virt
;
2779 unsigned long end
= addr
+ PAGE_ALIGN(size
);
2781 while (addr
< end
) {
2786 EXPORT_SYMBOL(free_pages_exact
);
2788 static unsigned int nr_free_zone_pages(int offset
)
2793 /* Just pick one node, since fallback list is circular */
2794 unsigned int sum
= 0;
2796 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
2798 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
2799 unsigned long size
= zone
->present_pages
;
2800 unsigned long high
= high_wmark_pages(zone
);
2809 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
2811 unsigned int nr_free_buffer_pages(void)
2813 return nr_free_zone_pages(gfp_zone(GFP_USER
));
2815 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
2818 * Amount of free RAM allocatable within all zones
2820 unsigned int nr_free_pagecache_pages(void)
2822 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
2825 static inline void show_node(struct zone
*zone
)
2827 if (IS_ENABLED(CONFIG_NUMA
))
2828 printk("Node %d ", zone_to_nid(zone
));
2831 void si_meminfo(struct sysinfo
*val
)
2833 val
->totalram
= totalram_pages
;
2835 val
->freeram
= global_page_state(NR_FREE_PAGES
);
2836 val
->bufferram
= nr_blockdev_pages();
2837 val
->totalhigh
= totalhigh_pages
;
2838 val
->freehigh
= nr_free_highpages();
2839 val
->mem_unit
= PAGE_SIZE
;
2842 EXPORT_SYMBOL(si_meminfo
);
2845 void si_meminfo_node(struct sysinfo
*val
, int nid
)
2847 pg_data_t
*pgdat
= NODE_DATA(nid
);
2849 val
->totalram
= pgdat
->node_present_pages
;
2850 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
2851 #ifdef CONFIG_HIGHMEM
2852 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].present_pages
;
2853 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
2859 val
->mem_unit
= PAGE_SIZE
;
2864 * Determine whether the node should be displayed or not, depending on whether
2865 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
2867 bool skip_free_areas_node(unsigned int flags
, int nid
)
2870 unsigned int cpuset_mems_cookie
;
2872 if (!(flags
& SHOW_MEM_FILTER_NODES
))
2876 cpuset_mems_cookie
= get_mems_allowed();
2877 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
2878 } while (!put_mems_allowed(cpuset_mems_cookie
));
2883 #define K(x) ((x) << (PAGE_SHIFT-10))
2885 static void show_migration_types(unsigned char type
)
2887 static const char types
[MIGRATE_TYPES
] = {
2888 [MIGRATE_UNMOVABLE
] = 'U',
2889 [MIGRATE_RECLAIMABLE
] = 'E',
2890 [MIGRATE_MOVABLE
] = 'M',
2891 [MIGRATE_RESERVE
] = 'R',
2893 [MIGRATE_CMA
] = 'C',
2895 [MIGRATE_ISOLATE
] = 'I',
2897 char tmp
[MIGRATE_TYPES
+ 1];
2901 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
2902 if (type
& (1 << i
))
2907 printk("(%s) ", tmp
);
2911 * Show free area list (used inside shift_scroll-lock stuff)
2912 * We also calculate the percentage fragmentation. We do this by counting the
2913 * memory on each free list with the exception of the first item on the list.
2914 * Suppresses nodes that are not allowed by current's cpuset if
2915 * SHOW_MEM_FILTER_NODES is passed.
2917 void show_free_areas(unsigned int filter
)
2922 for_each_populated_zone(zone
) {
2923 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
2926 printk("%s per-cpu:\n", zone
->name
);
2928 for_each_online_cpu(cpu
) {
2929 struct per_cpu_pageset
*pageset
;
2931 pageset
= per_cpu_ptr(zone
->pageset
, cpu
);
2933 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
2934 cpu
, pageset
->pcp
.high
,
2935 pageset
->pcp
.batch
, pageset
->pcp
.count
);
2939 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
2940 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
2942 " dirty:%lu writeback:%lu unstable:%lu\n"
2943 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2944 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
2946 global_page_state(NR_ACTIVE_ANON
),
2947 global_page_state(NR_INACTIVE_ANON
),
2948 global_page_state(NR_ISOLATED_ANON
),
2949 global_page_state(NR_ACTIVE_FILE
),
2950 global_page_state(NR_INACTIVE_FILE
),
2951 global_page_state(NR_ISOLATED_FILE
),
2952 global_page_state(NR_UNEVICTABLE
),
2953 global_page_state(NR_FILE_DIRTY
),
2954 global_page_state(NR_WRITEBACK
),
2955 global_page_state(NR_UNSTABLE_NFS
),
2956 global_page_state(NR_FREE_PAGES
),
2957 global_page_state(NR_SLAB_RECLAIMABLE
),
2958 global_page_state(NR_SLAB_UNRECLAIMABLE
),
2959 global_page_state(NR_FILE_MAPPED
),
2960 global_page_state(NR_SHMEM
),
2961 global_page_state(NR_PAGETABLE
),
2962 global_page_state(NR_BOUNCE
),
2963 global_page_state(NR_FREE_CMA_PAGES
));
2965 for_each_populated_zone(zone
) {
2968 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
2976 " active_anon:%lukB"
2977 " inactive_anon:%lukB"
2978 " active_file:%lukB"
2979 " inactive_file:%lukB"
2980 " unevictable:%lukB"
2981 " isolated(anon):%lukB"
2982 " isolated(file):%lukB"
2990 " slab_reclaimable:%lukB"
2991 " slab_unreclaimable:%lukB"
2992 " kernel_stack:%lukB"
2997 " writeback_tmp:%lukB"
2998 " pages_scanned:%lu"
2999 " all_unreclaimable? %s"
3002 K(zone_page_state(zone
, NR_FREE_PAGES
)),
3003 K(min_wmark_pages(zone
)),
3004 K(low_wmark_pages(zone
)),
3005 K(high_wmark_pages(zone
)),
3006 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
3007 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
3008 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
3009 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
3010 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
3011 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
3012 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
3013 K(zone
->present_pages
),
3014 K(zone
->managed_pages
),
3015 K(zone_page_state(zone
, NR_MLOCK
)),
3016 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
3017 K(zone_page_state(zone
, NR_WRITEBACK
)),
3018 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
3019 K(zone_page_state(zone
, NR_SHMEM
)),
3020 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
3021 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
3022 zone_page_state(zone
, NR_KERNEL_STACK
) *
3024 K(zone_page_state(zone
, NR_PAGETABLE
)),
3025 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
3026 K(zone_page_state(zone
, NR_BOUNCE
)),
3027 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)),
3028 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
3029 zone
->pages_scanned
,
3030 (zone
->all_unreclaimable
? "yes" : "no")
3032 printk("lowmem_reserve[]:");
3033 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3034 printk(" %lu", zone
->lowmem_reserve
[i
]);
3038 for_each_populated_zone(zone
) {
3039 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
3040 unsigned char types
[MAX_ORDER
];
3042 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3045 printk("%s: ", zone
->name
);
3047 spin_lock_irqsave(&zone
->lock
, flags
);
3048 for (order
= 0; order
< MAX_ORDER
; order
++) {
3049 struct free_area
*area
= &zone
->free_area
[order
];
3052 nr
[order
] = area
->nr_free
;
3053 total
+= nr
[order
] << order
;
3056 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
3057 if (!list_empty(&area
->free_list
[type
]))
3058 types
[order
] |= 1 << type
;
3061 spin_unlock_irqrestore(&zone
->lock
, flags
);
3062 for (order
= 0; order
< MAX_ORDER
; order
++) {
3063 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
3065 show_migration_types(types
[order
]);
3067 printk("= %lukB\n", K(total
));
3070 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
3072 show_swap_cache_info();
3075 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
3077 zoneref
->zone
= zone
;
3078 zoneref
->zone_idx
= zone_idx(zone
);
3082 * Builds allocation fallback zone lists.
3084 * Add all populated zones of a node to the zonelist.
3086 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
3087 int nr_zones
, enum zone_type zone_type
)
3091 BUG_ON(zone_type
>= MAX_NR_ZONES
);
3096 zone
= pgdat
->node_zones
+ zone_type
;
3097 if (populated_zone(zone
)) {
3098 zoneref_set_zone(zone
,
3099 &zonelist
->_zonerefs
[nr_zones
++]);
3100 check_highest_zone(zone_type
);
3103 } while (zone_type
);
3110 * 0 = automatic detection of better ordering.
3111 * 1 = order by ([node] distance, -zonetype)
3112 * 2 = order by (-zonetype, [node] distance)
3114 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3115 * the same zonelist. So only NUMA can configure this param.
3117 #define ZONELIST_ORDER_DEFAULT 0
3118 #define ZONELIST_ORDER_NODE 1
3119 #define ZONELIST_ORDER_ZONE 2
3121 /* zonelist order in the kernel.
3122 * set_zonelist_order() will set this to NODE or ZONE.
3124 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3125 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
3129 /* The value user specified ....changed by config */
3130 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3131 /* string for sysctl */
3132 #define NUMA_ZONELIST_ORDER_LEN 16
3133 char numa_zonelist_order
[16] = "default";
3136 * interface for configure zonelist ordering.
3137 * command line option "numa_zonelist_order"
3138 * = "[dD]efault - default, automatic configuration.
3139 * = "[nN]ode - order by node locality, then by zone within node
3140 * = "[zZ]one - order by zone, then by locality within zone
3143 static int __parse_numa_zonelist_order(char *s
)
3145 if (*s
== 'd' || *s
== 'D') {
3146 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3147 } else if (*s
== 'n' || *s
== 'N') {
3148 user_zonelist_order
= ZONELIST_ORDER_NODE
;
3149 } else if (*s
== 'z' || *s
== 'Z') {
3150 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
3153 "Ignoring invalid numa_zonelist_order value: "
3160 static __init
int setup_numa_zonelist_order(char *s
)
3167 ret
= __parse_numa_zonelist_order(s
);
3169 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
3173 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
3176 * sysctl handler for numa_zonelist_order
3178 int numa_zonelist_order_handler(ctl_table
*table
, int write
,
3179 void __user
*buffer
, size_t *length
,
3182 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
3184 static DEFINE_MUTEX(zl_order_mutex
);
3186 mutex_lock(&zl_order_mutex
);
3188 strcpy(saved_string
, (char*)table
->data
);
3189 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
3193 int oldval
= user_zonelist_order
;
3194 if (__parse_numa_zonelist_order((char*)table
->data
)) {
3196 * bogus value. restore saved string
3198 strncpy((char*)table
->data
, saved_string
,
3199 NUMA_ZONELIST_ORDER_LEN
);
3200 user_zonelist_order
= oldval
;
3201 } else if (oldval
!= user_zonelist_order
) {
3202 mutex_lock(&zonelists_mutex
);
3203 build_all_zonelists(NULL
, NULL
);
3204 mutex_unlock(&zonelists_mutex
);
3208 mutex_unlock(&zl_order_mutex
);
3213 #define MAX_NODE_LOAD (nr_online_nodes)
3214 static int node_load
[MAX_NUMNODES
];
3217 * find_next_best_node - find the next node that should appear in a given node's fallback list
3218 * @node: node whose fallback list we're appending
3219 * @used_node_mask: nodemask_t of already used nodes
3221 * We use a number of factors to determine which is the next node that should
3222 * appear on a given node's fallback list. The node should not have appeared
3223 * already in @node's fallback list, and it should be the next closest node
3224 * according to the distance array (which contains arbitrary distance values
3225 * from each node to each node in the system), and should also prefer nodes
3226 * with no CPUs, since presumably they'll have very little allocation pressure
3227 * on them otherwise.
3228 * It returns -1 if no node is found.
3230 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
3233 int min_val
= INT_MAX
;
3235 const struct cpumask
*tmp
= cpumask_of_node(0);
3237 /* Use the local node if we haven't already */
3238 if (!node_isset(node
, *used_node_mask
)) {
3239 node_set(node
, *used_node_mask
);
3243 for_each_node_state(n
, N_MEMORY
) {
3245 /* Don't want a node to appear more than once */
3246 if (node_isset(n
, *used_node_mask
))
3249 /* Use the distance array to find the distance */
3250 val
= node_distance(node
, n
);
3252 /* Penalize nodes under us ("prefer the next node") */
3255 /* Give preference to headless and unused nodes */
3256 tmp
= cpumask_of_node(n
);
3257 if (!cpumask_empty(tmp
))
3258 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
3260 /* Slight preference for less loaded node */
3261 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
3262 val
+= node_load
[n
];
3264 if (val
< min_val
) {
3271 node_set(best_node
, *used_node_mask
);
3278 * Build zonelists ordered by node and zones within node.
3279 * This results in maximum locality--normal zone overflows into local
3280 * DMA zone, if any--but risks exhausting DMA zone.
3282 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
3285 struct zonelist
*zonelist
;
3287 zonelist
= &pgdat
->node_zonelists
[0];
3288 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
3290 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3292 zonelist
->_zonerefs
[j
].zone
= NULL
;
3293 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3297 * Build gfp_thisnode zonelists
3299 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
3302 struct zonelist
*zonelist
;
3304 zonelist
= &pgdat
->node_zonelists
[1];
3305 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
3306 zonelist
->_zonerefs
[j
].zone
= NULL
;
3307 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3311 * Build zonelists ordered by zone and nodes within zones.
3312 * This results in conserving DMA zone[s] until all Normal memory is
3313 * exhausted, but results in overflowing to remote node while memory
3314 * may still exist in local DMA zone.
3316 static int node_order
[MAX_NUMNODES
];
3318 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
3321 int zone_type
; /* needs to be signed */
3323 struct zonelist
*zonelist
;
3325 zonelist
= &pgdat
->node_zonelists
[0];
3327 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
3328 for (j
= 0; j
< nr_nodes
; j
++) {
3329 node
= node_order
[j
];
3330 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
3331 if (populated_zone(z
)) {
3333 &zonelist
->_zonerefs
[pos
++]);
3334 check_highest_zone(zone_type
);
3338 zonelist
->_zonerefs
[pos
].zone
= NULL
;
3339 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
3342 static int default_zonelist_order(void)
3345 unsigned long low_kmem_size
,total_size
;
3349 * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
3350 * If they are really small and used heavily, the system can fall
3351 * into OOM very easily.
3352 * This function detect ZONE_DMA/DMA32 size and configures zone order.
3354 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
3357 for_each_online_node(nid
) {
3358 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
3359 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
3360 if (populated_zone(z
)) {
3361 if (zone_type
< ZONE_NORMAL
)
3362 low_kmem_size
+= z
->present_pages
;
3363 total_size
+= z
->present_pages
;
3364 } else if (zone_type
== ZONE_NORMAL
) {
3366 * If any node has only lowmem, then node order
3367 * is preferred to allow kernel allocations
3368 * locally; otherwise, they can easily infringe
3369 * on other nodes when there is an abundance of
3370 * lowmem available to allocate from.
3372 return ZONELIST_ORDER_NODE
;
3376 if (!low_kmem_size
|| /* there are no DMA area. */
3377 low_kmem_size
> total_size
/2) /* DMA/DMA32 is big. */
3378 return ZONELIST_ORDER_NODE
;
3380 * look into each node's config.
3381 * If there is a node whose DMA/DMA32 memory is very big area on
3382 * local memory, NODE_ORDER may be suitable.
3384 average_size
= total_size
/
3385 (nodes_weight(node_states
[N_MEMORY
]) + 1);
3386 for_each_online_node(nid
) {
3389 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++) {
3390 z
= &NODE_DATA(nid
)->node_zones
[zone_type
];
3391 if (populated_zone(z
)) {
3392 if (zone_type
< ZONE_NORMAL
)
3393 low_kmem_size
+= z
->present_pages
;
3394 total_size
+= z
->present_pages
;
3397 if (low_kmem_size
&&
3398 total_size
> average_size
&& /* ignore small node */
3399 low_kmem_size
> total_size
* 70/100)
3400 return ZONELIST_ORDER_NODE
;
3402 return ZONELIST_ORDER_ZONE
;
3405 static void set_zonelist_order(void)
3407 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
3408 current_zonelist_order
= default_zonelist_order();
3410 current_zonelist_order
= user_zonelist_order
;
3413 static void build_zonelists(pg_data_t
*pgdat
)
3417 nodemask_t used_mask
;
3418 int local_node
, prev_node
;
3419 struct zonelist
*zonelist
;
3420 int order
= current_zonelist_order
;
3422 /* initialize zonelists */
3423 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
3424 zonelist
= pgdat
->node_zonelists
+ i
;
3425 zonelist
->_zonerefs
[0].zone
= NULL
;
3426 zonelist
->_zonerefs
[0].zone_idx
= 0;
3429 /* NUMA-aware ordering of nodes */
3430 local_node
= pgdat
->node_id
;
3431 load
= nr_online_nodes
;
3432 prev_node
= local_node
;
3433 nodes_clear(used_mask
);
3435 memset(node_order
, 0, sizeof(node_order
));
3438 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
3440 * We don't want to pressure a particular node.
3441 * So adding penalty to the first node in same
3442 * distance group to make it round-robin.
3444 if (node_distance(local_node
, node
) !=
3445 node_distance(local_node
, prev_node
))
3446 node_load
[node
] = load
;
3450 if (order
== ZONELIST_ORDER_NODE
)
3451 build_zonelists_in_node_order(pgdat
, node
);
3453 node_order
[j
++] = node
; /* remember order */
3456 if (order
== ZONELIST_ORDER_ZONE
) {
3457 /* calculate node order -- i.e., DMA last! */
3458 build_zonelists_in_zone_order(pgdat
, j
);
3461 build_thisnode_zonelists(pgdat
);
3464 /* Construct the zonelist performance cache - see further mmzone.h */
3465 static void build_zonelist_cache(pg_data_t
*pgdat
)
3467 struct zonelist
*zonelist
;
3468 struct zonelist_cache
*zlc
;
3471 zonelist
= &pgdat
->node_zonelists
[0];
3472 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
3473 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
3474 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
3475 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
3478 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3480 * Return node id of node used for "local" allocations.
3481 * I.e., first node id of first zone in arg node's generic zonelist.
3482 * Used for initializing percpu 'numa_mem', which is used primarily
3483 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
3485 int local_memory_node(int node
)
3489 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
3490 gfp_zone(GFP_KERNEL
),
3497 #else /* CONFIG_NUMA */
3499 static void set_zonelist_order(void)
3501 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
3504 static void build_zonelists(pg_data_t
*pgdat
)
3506 int node
, local_node
;
3508 struct zonelist
*zonelist
;
3510 local_node
= pgdat
->node_id
;
3512 zonelist
= &pgdat
->node_zonelists
[0];
3513 j
= build_zonelists_node(pgdat
, zonelist
, 0, MAX_NR_ZONES
- 1);
3516 * Now we build the zonelist so that it contains the zones
3517 * of all the other nodes.
3518 * We don't want to pressure a particular node, so when
3519 * building the zones for node N, we make sure that the
3520 * zones coming right after the local ones are those from
3521 * node N+1 (modulo N)
3523 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
3524 if (!node_online(node
))
3526 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3529 for (node
= 0; node
< local_node
; node
++) {
3530 if (!node_online(node
))
3532 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
,
3536 zonelist
->_zonerefs
[j
].zone
= NULL
;
3537 zonelist
->_zonerefs
[j
].zone_idx
= 0;
3540 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3541 static void build_zonelist_cache(pg_data_t
*pgdat
)
3543 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
3546 #endif /* CONFIG_NUMA */
3549 * Boot pageset table. One per cpu which is going to be used for all
3550 * zones and all nodes. The parameters will be set in such a way
3551 * that an item put on a list will immediately be handed over to
3552 * the buddy list. This is safe since pageset manipulation is done
3553 * with interrupts disabled.
3555 * The boot_pagesets must be kept even after bootup is complete for
3556 * unused processors and/or zones. They do play a role for bootstrapping
3557 * hotplugged processors.
3559 * zoneinfo_show() and maybe other functions do
3560 * not check if the processor is online before following the pageset pointer.
3561 * Other parts of the kernel may not check if the zone is available.
3563 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
3564 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
3565 static void setup_zone_pageset(struct zone
*zone
);
3568 * Global mutex to protect against size modification of zonelists
3569 * as well as to serialize pageset setup for the new populated zone.
3571 DEFINE_MUTEX(zonelists_mutex
);
3573 /* return values int ....just for stop_machine() */
3574 static int __build_all_zonelists(void *data
)
3578 pg_data_t
*self
= data
;
3581 memset(node_load
, 0, sizeof(node_load
));
3584 if (self
&& !node_online(self
->node_id
)) {
3585 build_zonelists(self
);
3586 build_zonelist_cache(self
);
3589 for_each_online_node(nid
) {
3590 pg_data_t
*pgdat
= NODE_DATA(nid
);
3592 build_zonelists(pgdat
);
3593 build_zonelist_cache(pgdat
);
3597 * Initialize the boot_pagesets that are going to be used
3598 * for bootstrapping processors. The real pagesets for
3599 * each zone will be allocated later when the per cpu
3600 * allocator is available.
3602 * boot_pagesets are used also for bootstrapping offline
3603 * cpus if the system is already booted because the pagesets
3604 * are needed to initialize allocators on a specific cpu too.
3605 * F.e. the percpu allocator needs the page allocator which
3606 * needs the percpu allocator in order to allocate its pagesets
3607 * (a chicken-egg dilemma).
3609 for_each_possible_cpu(cpu
) {
3610 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
3612 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
3614 * We now know the "local memory node" for each node--
3615 * i.e., the node of the first zone in the generic zonelist.
3616 * Set up numa_mem percpu variable for on-line cpus. During
3617 * boot, only the boot cpu should be on-line; we'll init the
3618 * secondary cpus' numa_mem as they come on-line. During
3619 * node/memory hotplug, we'll fixup all on-line cpus.
3621 if (cpu_online(cpu
))
3622 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
3630 * Called with zonelists_mutex held always
3631 * unless system_state == SYSTEM_BOOTING.
3633 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
3635 set_zonelist_order();
3637 if (system_state
== SYSTEM_BOOTING
) {
3638 __build_all_zonelists(NULL
);
3639 mminit_verify_zonelist();
3640 cpuset_init_current_mems_allowed();
3642 /* we have to stop all cpus to guarantee there is no user
3644 #ifdef CONFIG_MEMORY_HOTPLUG
3646 setup_zone_pageset(zone
);
3648 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
3649 /* cpuset refresh routine should be here */
3651 vm_total_pages
= nr_free_pagecache_pages();
3653 * Disable grouping by mobility if the number of pages in the
3654 * system is too low to allow the mechanism to work. It would be
3655 * more accurate, but expensive to check per-zone. This check is
3656 * made on memory-hotadd so a system can start with mobility
3657 * disabled and enable it later
3659 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
3660 page_group_by_mobility_disabled
= 1;
3662 page_group_by_mobility_disabled
= 0;
3664 printk("Built %i zonelists in %s order, mobility grouping %s. "
3665 "Total pages: %ld\n",
3667 zonelist_order_name
[current_zonelist_order
],
3668 page_group_by_mobility_disabled
? "off" : "on",
3671 printk("Policy zone: %s\n", zone_names
[policy_zone
]);
3676 * Helper functions to size the waitqueue hash table.
3677 * Essentially these want to choose hash table sizes sufficiently
3678 * large so that collisions trying to wait on pages are rare.
3679 * But in fact, the number of active page waitqueues on typical
3680 * systems is ridiculously low, less than 200. So this is even
3681 * conservative, even though it seems large.
3683 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
3684 * waitqueues, i.e. the size of the waitq table given the number of pages.
3686 #define PAGES_PER_WAITQUEUE 256
3688 #ifndef CONFIG_MEMORY_HOTPLUG
3689 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3691 unsigned long size
= 1;
3693 pages
/= PAGES_PER_WAITQUEUE
;
3695 while (size
< pages
)
3699 * Once we have dozens or even hundreds of threads sleeping
3700 * on IO we've got bigger problems than wait queue collision.
3701 * Limit the size of the wait table to a reasonable size.
3703 size
= min(size
, 4096UL);
3705 return max(size
, 4UL);
3709 * A zone's size might be changed by hot-add, so it is not possible to determine
3710 * a suitable size for its wait_table. So we use the maximum size now.
3712 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
3714 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
3715 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
3716 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
3718 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
3719 * or more by the traditional way. (See above). It equals:
3721 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
3722 * ia64(16K page size) : = ( 8G + 4M)byte.
3723 * powerpc (64K page size) : = (32G +16M)byte.
3725 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
3732 * This is an integer logarithm so that shifts can be used later
3733 * to extract the more random high bits from the multiplicative
3734 * hash function before the remainder is taken.
3736 static inline unsigned long wait_table_bits(unsigned long size
)
3741 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
3744 * Check if a pageblock contains reserved pages
3746 static int pageblock_is_reserved(unsigned long start_pfn
, unsigned long end_pfn
)
3750 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
3751 if (!pfn_valid_within(pfn
) || PageReserved(pfn_to_page(pfn
)))
3758 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3759 * of blocks reserved is based on min_wmark_pages(zone). The memory within
3760 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3761 * higher will lead to a bigger reserve which will get freed as contiguous
3762 * blocks as reclaim kicks in
3764 static void setup_zone_migrate_reserve(struct zone
*zone
)
3766 unsigned long start_pfn
, pfn
, end_pfn
, block_end_pfn
;
3768 unsigned long block_migratetype
;
3772 * Get the start pfn, end pfn and the number of blocks to reserve
3773 * We have to be careful to be aligned to pageblock_nr_pages to
3774 * make sure that we always check pfn_valid for the first page in
3777 start_pfn
= zone
->zone_start_pfn
;
3778 end_pfn
= start_pfn
+ zone
->spanned_pages
;
3779 start_pfn
= roundup(start_pfn
, pageblock_nr_pages
);
3780 reserve
= roundup(min_wmark_pages(zone
), pageblock_nr_pages
) >>
3784 * Reserve blocks are generally in place to help high-order atomic
3785 * allocations that are short-lived. A min_free_kbytes value that
3786 * would result in more than 2 reserve blocks for atomic allocations
3787 * is assumed to be in place to help anti-fragmentation for the
3788 * future allocation of hugepages at runtime.
3790 reserve
= min(2, reserve
);
3792 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
3793 if (!pfn_valid(pfn
))
3795 page
= pfn_to_page(pfn
);
3797 /* Watch out for overlapping nodes */
3798 if (page_to_nid(page
) != zone_to_nid(zone
))
3801 block_migratetype
= get_pageblock_migratetype(page
);
3803 /* Only test what is necessary when the reserves are not met */
3806 * Blocks with reserved pages will never free, skip
3809 block_end_pfn
= min(pfn
+ pageblock_nr_pages
, end_pfn
);
3810 if (pageblock_is_reserved(pfn
, block_end_pfn
))
3813 /* If this block is reserved, account for it */
3814 if (block_migratetype
== MIGRATE_RESERVE
) {
3819 /* Suitable for reserving if this block is movable */
3820 if (block_migratetype
== MIGRATE_MOVABLE
) {
3821 set_pageblock_migratetype(page
,
3823 move_freepages_block(zone
, page
,
3831 * If the reserve is met and this is a previous reserved block,
3834 if (block_migratetype
== MIGRATE_RESERVE
) {
3835 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3836 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
3842 * Initially all pages are reserved - free ones are freed
3843 * up by free_all_bootmem() once the early boot process is
3844 * done. Non-atomic initialization, single-pass.
3846 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
3847 unsigned long start_pfn
, enum memmap_context context
)
3850 unsigned long end_pfn
= start_pfn
+ size
;
3854 if (highest_memmap_pfn
< end_pfn
- 1)
3855 highest_memmap_pfn
= end_pfn
- 1;
3857 z
= &NODE_DATA(nid
)->node_zones
[zone
];
3858 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
3860 * There can be holes in boot-time mem_map[]s
3861 * handed to this function. They do not
3862 * exist on hotplugged memory.
3864 if (context
== MEMMAP_EARLY
) {
3865 if (!early_pfn_valid(pfn
))
3867 if (!early_pfn_in_nid(pfn
, nid
))
3870 page
= pfn_to_page(pfn
);
3871 set_page_links(page
, zone
, nid
, pfn
);
3872 mminit_verify_page_links(page
, zone
, nid
, pfn
);
3873 init_page_count(page
);
3874 reset_page_mapcount(page
);
3875 reset_page_last_nid(page
);
3876 SetPageReserved(page
);
3878 * Mark the block movable so that blocks are reserved for
3879 * movable at startup. This will force kernel allocations
3880 * to reserve their blocks rather than leaking throughout
3881 * the address space during boot when many long-lived
3882 * kernel allocations are made. Later some blocks near
3883 * the start are marked MIGRATE_RESERVE by
3884 * setup_zone_migrate_reserve()
3886 * bitmap is created for zone's valid pfn range. but memmap
3887 * can be created for invalid pages (for alignment)
3888 * check here not to call set_pageblock_migratetype() against
3891 if ((z
->zone_start_pfn
<= pfn
)
3892 && (pfn
< z
->zone_start_pfn
+ z
->spanned_pages
)
3893 && !(pfn
& (pageblock_nr_pages
- 1)))
3894 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
3896 INIT_LIST_HEAD(&page
->lru
);
3897 #ifdef WANT_PAGE_VIRTUAL
3898 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
3899 if (!is_highmem_idx(zone
))
3900 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
3905 static void __meminit
zone_init_free_lists(struct zone
*zone
)
3908 for_each_migratetype_order(order
, t
) {
3909 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
3910 zone
->free_area
[order
].nr_free
= 0;
3914 #ifndef __HAVE_ARCH_MEMMAP_INIT
3915 #define memmap_init(size, nid, zone, start_pfn) \
3916 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
3919 static int __meminit
zone_batchsize(struct zone
*zone
)
3925 * The per-cpu-pages pools are set to around 1000th of the
3926 * size of the zone. But no more than 1/2 of a meg.
3928 * OK, so we don't know how big the cache is. So guess.
3930 batch
= zone
->present_pages
/ 1024;
3931 if (batch
* PAGE_SIZE
> 512 * 1024)
3932 batch
= (512 * 1024) / PAGE_SIZE
;
3933 batch
/= 4; /* We effectively *= 4 below */
3938 * Clamp the batch to a 2^n - 1 value. Having a power
3939 * of 2 value was found to be more likely to have
3940 * suboptimal cache aliasing properties in some cases.
3942 * For example if 2 tasks are alternately allocating
3943 * batches of pages, one task can end up with a lot
3944 * of pages of one half of the possible page colors
3945 * and the other with pages of the other colors.
3947 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
3952 /* The deferral and batching of frees should be suppressed under NOMMU
3955 * The problem is that NOMMU needs to be able to allocate large chunks
3956 * of contiguous memory as there's no hardware page translation to
3957 * assemble apparent contiguous memory from discontiguous pages.
3959 * Queueing large contiguous runs of pages for batching, however,
3960 * causes the pages to actually be freed in smaller chunks. As there
3961 * can be a significant delay between the individual batches being
3962 * recycled, this leads to the once large chunks of space being
3963 * fragmented and becoming unavailable for high-order allocations.
3969 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
3971 struct per_cpu_pages
*pcp
;
3974 memset(p
, 0, sizeof(*p
));
3978 pcp
->high
= 6 * batch
;
3979 pcp
->batch
= max(1UL, 1 * batch
);
3980 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
3981 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
3985 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
3986 * to the value high for the pageset p.
3989 static void setup_pagelist_highmark(struct per_cpu_pageset
*p
,
3992 struct per_cpu_pages
*pcp
;
3996 pcp
->batch
= max(1UL, high
/4);
3997 if ((high
/4) > (PAGE_SHIFT
* 8))
3998 pcp
->batch
= PAGE_SHIFT
* 8;
4001 static void __meminit
setup_zone_pageset(struct zone
*zone
)
4005 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
4007 for_each_possible_cpu(cpu
) {
4008 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
4010 setup_pageset(pcp
, zone_batchsize(zone
));
4012 if (percpu_pagelist_fraction
)
4013 setup_pagelist_highmark(pcp
,
4014 (zone
->present_pages
/
4015 percpu_pagelist_fraction
));
4020 * Allocate per cpu pagesets and initialize them.
4021 * Before this call only boot pagesets were available.
4023 void __init
setup_per_cpu_pageset(void)
4027 for_each_populated_zone(zone
)
4028 setup_zone_pageset(zone
);
4031 static noinline __init_refok
4032 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
4035 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
4039 * The per-page waitqueue mechanism uses hashed waitqueues
4042 zone
->wait_table_hash_nr_entries
=
4043 wait_table_hash_nr_entries(zone_size_pages
);
4044 zone
->wait_table_bits
=
4045 wait_table_bits(zone
->wait_table_hash_nr_entries
);
4046 alloc_size
= zone
->wait_table_hash_nr_entries
4047 * sizeof(wait_queue_head_t
);
4049 if (!slab_is_available()) {
4050 zone
->wait_table
= (wait_queue_head_t
*)
4051 alloc_bootmem_node_nopanic(pgdat
, alloc_size
);
4054 * This case means that a zone whose size was 0 gets new memory
4055 * via memory hot-add.
4056 * But it may be the case that a new node was hot-added. In
4057 * this case vmalloc() will not be able to use this new node's
4058 * memory - this wait_table must be initialized to use this new
4059 * node itself as well.
4060 * To use this new node's memory, further consideration will be
4063 zone
->wait_table
= vmalloc(alloc_size
);
4065 if (!zone
->wait_table
)
4068 for(i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
4069 init_waitqueue_head(zone
->wait_table
+ i
);
4074 static __meminit
void zone_pcp_init(struct zone
*zone
)
4077 * per cpu subsystem is not up at this point. The following code
4078 * relies on the ability of the linker to provide the
4079 * offset of a (static) per cpu variable into the per cpu area.
4081 zone
->pageset
= &boot_pageset
;
4083 if (zone
->present_pages
)
4084 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
4085 zone
->name
, zone
->present_pages
,
4086 zone_batchsize(zone
));
4089 int __meminit
init_currently_empty_zone(struct zone
*zone
,
4090 unsigned long zone_start_pfn
,
4092 enum memmap_context context
)
4094 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
4096 ret
= zone_wait_table_init(zone
, size
);
4099 pgdat
->nr_zones
= zone_idx(zone
) + 1;
4101 zone
->zone_start_pfn
= zone_start_pfn
;
4103 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
4104 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4106 (unsigned long)zone_idx(zone
),
4107 zone_start_pfn
, (zone_start_pfn
+ size
));
4109 zone_init_free_lists(zone
);
4114 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4115 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4117 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4118 * Architectures may implement their own version but if add_active_range()
4119 * was used and there are no special requirements, this is a convenient
4122 int __meminit
__early_pfn_to_nid(unsigned long pfn
)
4124 unsigned long start_pfn
, end_pfn
;
4127 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
4128 if (start_pfn
<= pfn
&& pfn
< end_pfn
)
4130 /* This is a memory hole */
4133 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4135 int __meminit
early_pfn_to_nid(unsigned long pfn
)
4139 nid
= __early_pfn_to_nid(pfn
);
4142 /* just returns 0 */
4146 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
4147 bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
4151 nid
= __early_pfn_to_nid(pfn
);
4152 if (nid
>= 0 && nid
!= node
)
4159 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
4160 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4161 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
4163 * If an architecture guarantees that all ranges registered with
4164 * add_active_ranges() contain no holes and may be freed, this
4165 * this function may be used instead of calling free_bootmem() manually.
4167 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
4169 unsigned long start_pfn
, end_pfn
;
4172 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
4173 start_pfn
= min(start_pfn
, max_low_pfn
);
4174 end_pfn
= min(end_pfn
, max_low_pfn
);
4176 if (start_pfn
< end_pfn
)
4177 free_bootmem_node(NODE_DATA(this_nid
),
4178 PFN_PHYS(start_pfn
),
4179 (end_pfn
- start_pfn
) << PAGE_SHIFT
);
4184 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4185 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4187 * If an architecture guarantees that all ranges registered with
4188 * add_active_ranges() contain no holes and may be freed, this
4189 * function may be used instead of calling memory_present() manually.
4191 void __init
sparse_memory_present_with_active_regions(int nid
)
4193 unsigned long start_pfn
, end_pfn
;
4196 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
4197 memory_present(this_nid
, start_pfn
, end_pfn
);
4201 * get_pfn_range_for_nid - Return the start and end page frames for a node
4202 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4203 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
4204 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
4206 * It returns the start and end page frame of a node based on information
4207 * provided by an arch calling add_active_range(). If called for a node
4208 * with no available memory, a warning is printed and the start and end
4211 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
4212 unsigned long *start_pfn
, unsigned long *end_pfn
)
4214 unsigned long this_start_pfn
, this_end_pfn
;
4220 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
4221 *start_pfn
= min(*start_pfn
, this_start_pfn
);
4222 *end_pfn
= max(*end_pfn
, this_end_pfn
);
4225 if (*start_pfn
== -1UL)
4230 * This finds a zone that can be used for ZONE_MOVABLE pages. The
4231 * assumption is made that zones within a node are ordered in monotonic
4232 * increasing memory addresses so that the "highest" populated zone is used
4234 static void __init
find_usable_zone_for_movable(void)
4237 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
4238 if (zone_index
== ZONE_MOVABLE
)
4241 if (arch_zone_highest_possible_pfn
[zone_index
] >
4242 arch_zone_lowest_possible_pfn
[zone_index
])
4246 VM_BUG_ON(zone_index
== -1);
4247 movable_zone
= zone_index
;
4251 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4252 * because it is sized independent of architecture. Unlike the other zones,
4253 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4254 * in each node depending on the size of each node and how evenly kernelcore
4255 * is distributed. This helper function adjusts the zone ranges
4256 * provided by the architecture for a given node by using the end of the
4257 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4258 * zones within a node are in order of monotonic increases memory addresses
4260 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
4261 unsigned long zone_type
,
4262 unsigned long node_start_pfn
,
4263 unsigned long node_end_pfn
,
4264 unsigned long *zone_start_pfn
,
4265 unsigned long *zone_end_pfn
)
4267 /* Only adjust if ZONE_MOVABLE is on this node */
4268 if (zone_movable_pfn
[nid
]) {
4269 /* Size ZONE_MOVABLE */
4270 if (zone_type
== ZONE_MOVABLE
) {
4271 *zone_start_pfn
= zone_movable_pfn
[nid
];
4272 *zone_end_pfn
= min(node_end_pfn
,
4273 arch_zone_highest_possible_pfn
[movable_zone
]);
4275 /* Adjust for ZONE_MOVABLE starting within this range */
4276 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
4277 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
4278 *zone_end_pfn
= zone_movable_pfn
[nid
];
4280 /* Check if this whole range is within ZONE_MOVABLE */
4281 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
4282 *zone_start_pfn
= *zone_end_pfn
;
4287 * Return the number of pages a zone spans in a node, including holes
4288 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
4290 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4291 unsigned long zone_type
,
4292 unsigned long *ignored
)
4294 unsigned long node_start_pfn
, node_end_pfn
;
4295 unsigned long zone_start_pfn
, zone_end_pfn
;
4297 /* Get the start and end of the node and zone */
4298 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
4299 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
4300 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
4301 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4302 node_start_pfn
, node_end_pfn
,
4303 &zone_start_pfn
, &zone_end_pfn
);
4305 /* Check that this node has pages within the zone's required range */
4306 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
4309 /* Move the zone boundaries inside the node if necessary */
4310 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
4311 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
4313 /* Return the spanned pages */
4314 return zone_end_pfn
- zone_start_pfn
;
4318 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
4319 * then all holes in the requested range will be accounted for.
4321 unsigned long __meminit
__absent_pages_in_range(int nid
,
4322 unsigned long range_start_pfn
,
4323 unsigned long range_end_pfn
)
4325 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
4326 unsigned long start_pfn
, end_pfn
;
4329 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
4330 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
4331 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
4332 nr_absent
-= end_pfn
- start_pfn
;
4338 * absent_pages_in_range - Return number of page frames in holes within a range
4339 * @start_pfn: The start PFN to start searching for holes
4340 * @end_pfn: The end PFN to stop searching for holes
4342 * It returns the number of pages frames in memory holes within a range.
4344 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
4345 unsigned long end_pfn
)
4347 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
4350 /* Return the number of page frames in holes in a zone on a node */
4351 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4352 unsigned long zone_type
,
4353 unsigned long *ignored
)
4355 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
4356 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
4357 unsigned long node_start_pfn
, node_end_pfn
;
4358 unsigned long zone_start_pfn
, zone_end_pfn
;
4360 get_pfn_range_for_nid(nid
, &node_start_pfn
, &node_end_pfn
);
4361 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
4362 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
4364 adjust_zone_range_for_zone_movable(nid
, zone_type
,
4365 node_start_pfn
, node_end_pfn
,
4366 &zone_start_pfn
, &zone_end_pfn
);
4367 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
4370 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4371 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
4372 unsigned long zone_type
,
4373 unsigned long *zones_size
)
4375 return zones_size
[zone_type
];
4378 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
4379 unsigned long zone_type
,
4380 unsigned long *zholes_size
)
4385 return zholes_size
[zone_type
];
4388 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4390 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
4391 unsigned long *zones_size
, unsigned long *zholes_size
)
4393 unsigned long realtotalpages
, totalpages
= 0;
4396 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4397 totalpages
+= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
4399 pgdat
->node_spanned_pages
= totalpages
;
4401 realtotalpages
= totalpages
;
4402 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
4404 zone_absent_pages_in_node(pgdat
->node_id
, i
,
4406 pgdat
->node_present_pages
= realtotalpages
;
4407 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
4411 #ifndef CONFIG_SPARSEMEM
4413 * Calculate the size of the zone->blockflags rounded to an unsigned long
4414 * Start by making sure zonesize is a multiple of pageblock_order by rounding
4415 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
4416 * round what is now in bits to nearest long in bits, then return it in
4419 static unsigned long __init
usemap_size(unsigned long zonesize
)
4421 unsigned long usemapsize
;
4423 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
4424 usemapsize
= usemapsize
>> pageblock_order
;
4425 usemapsize
*= NR_PAGEBLOCK_BITS
;
4426 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
4428 return usemapsize
/ 8;
4431 static void __init
setup_usemap(struct pglist_data
*pgdat
,
4432 struct zone
*zone
, unsigned long zonesize
)
4434 unsigned long usemapsize
= usemap_size(zonesize
);
4435 zone
->pageblock_flags
= NULL
;
4437 zone
->pageblock_flags
= alloc_bootmem_node_nopanic(pgdat
,
4441 static inline void setup_usemap(struct pglist_data
*pgdat
,
4442 struct zone
*zone
, unsigned long zonesize
) {}
4443 #endif /* CONFIG_SPARSEMEM */
4445 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4447 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4448 void __init
set_pageblock_order(void)
4452 /* Check that pageblock_nr_pages has not already been setup */
4453 if (pageblock_order
)
4456 if (HPAGE_SHIFT
> PAGE_SHIFT
)
4457 order
= HUGETLB_PAGE_ORDER
;
4459 order
= MAX_ORDER
- 1;
4462 * Assume the largest contiguous order of interest is a huge page.
4463 * This value may be variable depending on boot parameters on IA64 and
4466 pageblock_order
= order
;
4468 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4471 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4472 * is unused as pageblock_order is set at compile-time. See
4473 * include/linux/pageblock-flags.h for the values of pageblock_order based on
4476 void __init
set_pageblock_order(void)
4480 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
4482 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
4483 unsigned long present_pages
)
4485 unsigned long pages
= spanned_pages
;
4488 * Provide a more accurate estimation if there are holes within
4489 * the zone and SPARSEMEM is in use. If there are holes within the
4490 * zone, each populated memory region may cost us one or two extra
4491 * memmap pages due to alignment because memmap pages for each
4492 * populated regions may not naturally algined on page boundary.
4493 * So the (present_pages >> 4) heuristic is a tradeoff for that.
4495 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
4496 IS_ENABLED(CONFIG_SPARSEMEM
))
4497 pages
= present_pages
;
4499 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
4503 * Set up the zone data structures:
4504 * - mark all pages reserved
4505 * - mark all memory queues empty
4506 * - clear the memory bitmaps
4508 * NOTE: pgdat should get zeroed by caller.
4510 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
,
4511 unsigned long *zones_size
, unsigned long *zholes_size
)
4514 int nid
= pgdat
->node_id
;
4515 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
4518 pgdat_resize_init(pgdat
);
4519 #ifdef CONFIG_NUMA_BALANCING
4520 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
4521 pgdat
->numabalancing_migrate_nr_pages
= 0;
4522 pgdat
->numabalancing_migrate_next_window
= jiffies
;
4524 init_waitqueue_head(&pgdat
->kswapd_wait
);
4525 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
4526 pgdat_page_cgroup_init(pgdat
);
4528 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
4529 struct zone
*zone
= pgdat
->node_zones
+ j
;
4530 unsigned long size
, realsize
, freesize
, memmap_pages
;
4532 size
= zone_spanned_pages_in_node(nid
, j
, zones_size
);
4533 realsize
= freesize
= size
- zone_absent_pages_in_node(nid
, j
,
4537 * Adjust freesize so that it accounts for how much memory
4538 * is used by this zone for memmap. This affects the watermark
4539 * and per-cpu initialisations
4541 memmap_pages
= calc_memmap_size(size
, realsize
);
4542 if (freesize
>= memmap_pages
) {
4543 freesize
-= memmap_pages
;
4546 " %s zone: %lu pages used for memmap\n",
4547 zone_names
[j
], memmap_pages
);
4550 " %s zone: %lu pages exceeds freesize %lu\n",
4551 zone_names
[j
], memmap_pages
, freesize
);
4553 /* Account for reserved pages */
4554 if (j
== 0 && freesize
> dma_reserve
) {
4555 freesize
-= dma_reserve
;
4556 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
4557 zone_names
[0], dma_reserve
);
4560 if (!is_highmem_idx(j
))
4561 nr_kernel_pages
+= freesize
;
4562 /* Charge for highmem memmap if there are enough kernel pages */
4563 else if (nr_kernel_pages
> memmap_pages
* 2)
4564 nr_kernel_pages
-= memmap_pages
;
4565 nr_all_pages
+= freesize
;
4567 zone
->spanned_pages
= size
;
4568 zone
->present_pages
= freesize
;
4570 * Set an approximate value for lowmem here, it will be adjusted
4571 * when the bootmem allocator frees pages into the buddy system.
4572 * And all highmem pages will be managed by the buddy system.
4574 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
4577 zone
->min_unmapped_pages
= (freesize
*sysctl_min_unmapped_ratio
)
4579 zone
->min_slab_pages
= (freesize
* sysctl_min_slab_ratio
) / 100;
4581 zone
->name
= zone_names
[j
];
4582 spin_lock_init(&zone
->lock
);
4583 spin_lock_init(&zone
->lru_lock
);
4584 zone_seqlock_init(zone
);
4585 zone
->zone_pgdat
= pgdat
;
4587 zone_pcp_init(zone
);
4588 lruvec_init(&zone
->lruvec
);
4592 set_pageblock_order();
4593 setup_usemap(pgdat
, zone
, size
);
4594 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
4595 size
, MEMMAP_EARLY
);
4597 memmap_init(size
, nid
, j
, zone_start_pfn
);
4598 zone_start_pfn
+= size
;
4602 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
4604 /* Skip empty nodes */
4605 if (!pgdat
->node_spanned_pages
)
4608 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4609 /* ia64 gets its own node_mem_map, before this, without bootmem */
4610 if (!pgdat
->node_mem_map
) {
4611 unsigned long size
, start
, end
;
4615 * The zone's endpoints aren't required to be MAX_ORDER
4616 * aligned but the node_mem_map endpoints must be in order
4617 * for the buddy allocator to function correctly.
4619 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
4620 end
= pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
4621 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
4622 size
= (end
- start
) * sizeof(struct page
);
4623 map
= alloc_remap(pgdat
->node_id
, size
);
4625 map
= alloc_bootmem_node_nopanic(pgdat
, size
);
4626 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
4628 #ifndef CONFIG_NEED_MULTIPLE_NODES
4630 * With no DISCONTIG, the global mem_map is just set as node 0's
4632 if (pgdat
== NODE_DATA(0)) {
4633 mem_map
= NODE_DATA(0)->node_mem_map
;
4634 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4635 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
4636 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
4637 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4640 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
4643 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
4644 unsigned long node_start_pfn
, unsigned long *zholes_size
)
4646 pg_data_t
*pgdat
= NODE_DATA(nid
);
4648 /* pg_data_t should be reset to zero when it's allocated */
4649 WARN_ON(pgdat
->nr_zones
|| pgdat
->classzone_idx
);
4651 pgdat
->node_id
= nid
;
4652 pgdat
->node_start_pfn
= node_start_pfn
;
4653 init_zone_allows_reclaim(nid
);
4654 calculate_node_totalpages(pgdat
, zones_size
, zholes_size
);
4656 alloc_node_mem_map(pgdat
);
4657 #ifdef CONFIG_FLAT_NODE_MEM_MAP
4658 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
4659 nid
, (unsigned long)pgdat
,
4660 (unsigned long)pgdat
->node_mem_map
);
4663 free_area_init_core(pgdat
, zones_size
, zholes_size
);
4666 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4668 #if MAX_NUMNODES > 1
4670 * Figure out the number of possible node ids.
4672 static void __init
setup_nr_node_ids(void)
4675 unsigned int highest
= 0;
4677 for_each_node_mask(node
, node_possible_map
)
4679 nr_node_ids
= highest
+ 1;
4682 static inline void setup_nr_node_ids(void)
4688 * node_map_pfn_alignment - determine the maximum internode alignment
4690 * This function should be called after node map is populated and sorted.
4691 * It calculates the maximum power of two alignment which can distinguish
4694 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
4695 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
4696 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
4697 * shifted, 1GiB is enough and this function will indicate so.
4699 * This is used to test whether pfn -> nid mapping of the chosen memory
4700 * model has fine enough granularity to avoid incorrect mapping for the
4701 * populated node map.
4703 * Returns the determined alignment in pfn's. 0 if there is no alignment
4704 * requirement (single node).
4706 unsigned long __init
node_map_pfn_alignment(void)
4708 unsigned long accl_mask
= 0, last_end
= 0;
4709 unsigned long start
, end
, mask
;
4713 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
4714 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
4721 * Start with a mask granular enough to pin-point to the
4722 * start pfn and tick off bits one-by-one until it becomes
4723 * too coarse to separate the current node from the last.
4725 mask
= ~((1 << __ffs(start
)) - 1);
4726 while (mask
&& last_end
<= (start
& (mask
<< 1)))
4729 /* accumulate all internode masks */
4733 /* convert mask to number of pages */
4734 return ~accl_mask
+ 1;
4737 /* Find the lowest pfn for a node */
4738 static unsigned long __init
find_min_pfn_for_node(int nid
)
4740 unsigned long min_pfn
= ULONG_MAX
;
4741 unsigned long start_pfn
;
4744 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
4745 min_pfn
= min(min_pfn
, start_pfn
);
4747 if (min_pfn
== ULONG_MAX
) {
4749 "Could not find start_pfn for node %d\n", nid
);
4757 * find_min_pfn_with_active_regions - Find the minimum PFN registered
4759 * It returns the minimum PFN based on information provided via
4760 * add_active_range().
4762 unsigned long __init
find_min_pfn_with_active_regions(void)
4764 return find_min_pfn_for_node(MAX_NUMNODES
);
4768 * early_calculate_totalpages()
4769 * Sum pages in active regions for movable zone.
4770 * Populate N_MEMORY for calculating usable_nodes.
4772 static unsigned long __init
early_calculate_totalpages(void)
4774 unsigned long totalpages
= 0;
4775 unsigned long start_pfn
, end_pfn
;
4778 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
4779 unsigned long pages
= end_pfn
- start_pfn
;
4781 totalpages
+= pages
;
4783 node_set_state(nid
, N_MEMORY
);
4789 * Find the PFN the Movable zone begins in each node. Kernel memory
4790 * is spread evenly between nodes as long as the nodes have enough
4791 * memory. When they don't, some nodes will have more kernelcore than
4794 static void __init
find_zone_movable_pfns_for_nodes(void)
4797 unsigned long usable_startpfn
;
4798 unsigned long kernelcore_node
, kernelcore_remaining
;
4799 /* save the state before borrow the nodemask */
4800 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
4801 unsigned long totalpages
= early_calculate_totalpages();
4802 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
4805 * If movablecore was specified, calculate what size of
4806 * kernelcore that corresponds so that memory usable for
4807 * any allocation type is evenly spread. If both kernelcore
4808 * and movablecore are specified, then the value of kernelcore
4809 * will be used for required_kernelcore if it's greater than
4810 * what movablecore would have allowed.
4812 if (required_movablecore
) {
4813 unsigned long corepages
;
4816 * Round-up so that ZONE_MOVABLE is at least as large as what
4817 * was requested by the user
4819 required_movablecore
=
4820 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
4821 corepages
= totalpages
- required_movablecore
;
4823 required_kernelcore
= max(required_kernelcore
, corepages
);
4826 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
4827 if (!required_kernelcore
)
4830 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
4831 find_usable_zone_for_movable();
4832 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
4835 /* Spread kernelcore memory as evenly as possible throughout nodes */
4836 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4837 for_each_node_state(nid
, N_MEMORY
) {
4838 unsigned long start_pfn
, end_pfn
;
4841 * Recalculate kernelcore_node if the division per node
4842 * now exceeds what is necessary to satisfy the requested
4843 * amount of memory for the kernel
4845 if (required_kernelcore
< kernelcore_node
)
4846 kernelcore_node
= required_kernelcore
/ usable_nodes
;
4849 * As the map is walked, we track how much memory is usable
4850 * by the kernel using kernelcore_remaining. When it is
4851 * 0, the rest of the node is usable by ZONE_MOVABLE
4853 kernelcore_remaining
= kernelcore_node
;
4855 /* Go through each range of PFNs within this node */
4856 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
4857 unsigned long size_pages
;
4859 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
4860 if (start_pfn
>= end_pfn
)
4863 /* Account for what is only usable for kernelcore */
4864 if (start_pfn
< usable_startpfn
) {
4865 unsigned long kernel_pages
;
4866 kernel_pages
= min(end_pfn
, usable_startpfn
)
4869 kernelcore_remaining
-= min(kernel_pages
,
4870 kernelcore_remaining
);
4871 required_kernelcore
-= min(kernel_pages
,
4872 required_kernelcore
);
4874 /* Continue if range is now fully accounted */
4875 if (end_pfn
<= usable_startpfn
) {
4878 * Push zone_movable_pfn to the end so
4879 * that if we have to rebalance
4880 * kernelcore across nodes, we will
4881 * not double account here
4883 zone_movable_pfn
[nid
] = end_pfn
;
4886 start_pfn
= usable_startpfn
;
4890 * The usable PFN range for ZONE_MOVABLE is from
4891 * start_pfn->end_pfn. Calculate size_pages as the
4892 * number of pages used as kernelcore
4894 size_pages
= end_pfn
- start_pfn
;
4895 if (size_pages
> kernelcore_remaining
)
4896 size_pages
= kernelcore_remaining
;
4897 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
4900 * Some kernelcore has been met, update counts and
4901 * break if the kernelcore for this node has been
4904 required_kernelcore
-= min(required_kernelcore
,
4906 kernelcore_remaining
-= size_pages
;
4907 if (!kernelcore_remaining
)
4913 * If there is still required_kernelcore, we do another pass with one
4914 * less node in the count. This will push zone_movable_pfn[nid] further
4915 * along on the nodes that still have memory until kernelcore is
4919 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
4922 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
4923 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
4924 zone_movable_pfn
[nid
] =
4925 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
4928 /* restore the node_state */
4929 node_states
[N_MEMORY
] = saved_node_state
;
4932 /* Any regular or high memory on that node ? */
4933 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
4935 enum zone_type zone_type
;
4937 if (N_MEMORY
== N_NORMAL_MEMORY
)
4940 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
4941 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
4942 if (zone
->present_pages
) {
4943 node_set_state(nid
, N_HIGH_MEMORY
);
4944 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
4945 zone_type
<= ZONE_NORMAL
)
4946 node_set_state(nid
, N_NORMAL_MEMORY
);
4953 * free_area_init_nodes - Initialise all pg_data_t and zone data
4954 * @max_zone_pfn: an array of max PFNs for each zone
4956 * This will call free_area_init_node() for each active node in the system.
4957 * Using the page ranges provided by add_active_range(), the size of each
4958 * zone in each node and their holes is calculated. If the maximum PFN
4959 * between two adjacent zones match, it is assumed that the zone is empty.
4960 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
4961 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
4962 * starts where the previous one ended. For example, ZONE_DMA32 starts
4963 * at arch_max_dma_pfn.
4965 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
4967 unsigned long start_pfn
, end_pfn
;
4970 /* Record where the zone boundaries are */
4971 memset(arch_zone_lowest_possible_pfn
, 0,
4972 sizeof(arch_zone_lowest_possible_pfn
));
4973 memset(arch_zone_highest_possible_pfn
, 0,
4974 sizeof(arch_zone_highest_possible_pfn
));
4975 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
4976 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
4977 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
4978 if (i
== ZONE_MOVABLE
)
4980 arch_zone_lowest_possible_pfn
[i
] =
4981 arch_zone_highest_possible_pfn
[i
-1];
4982 arch_zone_highest_possible_pfn
[i
] =
4983 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
4985 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
4986 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
4988 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
4989 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
4990 find_zone_movable_pfns_for_nodes();
4992 /* Print out the zone ranges */
4993 printk("Zone ranges:\n");
4994 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
4995 if (i
== ZONE_MOVABLE
)
4997 printk(KERN_CONT
" %-8s ", zone_names
[i
]);
4998 if (arch_zone_lowest_possible_pfn
[i
] ==
4999 arch_zone_highest_possible_pfn
[i
])
5000 printk(KERN_CONT
"empty\n");
5002 printk(KERN_CONT
"[mem %0#10lx-%0#10lx]\n",
5003 arch_zone_lowest_possible_pfn
[i
] << PAGE_SHIFT
,
5004 (arch_zone_highest_possible_pfn
[i
]
5005 << PAGE_SHIFT
) - 1);
5008 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5009 printk("Movable zone start for each node\n");
5010 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
5011 if (zone_movable_pfn
[i
])
5012 printk(" Node %d: %#010lx\n", i
,
5013 zone_movable_pfn
[i
] << PAGE_SHIFT
);
5016 /* Print out the early node map */
5017 printk("Early memory node ranges\n");
5018 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
5019 printk(" node %3d: [mem %#010lx-%#010lx]\n", nid
,
5020 start_pfn
<< PAGE_SHIFT
, (end_pfn
<< PAGE_SHIFT
) - 1);
5022 /* Initialise every node */
5023 mminit_verify_pageflags_layout();
5024 setup_nr_node_ids();
5025 for_each_online_node(nid
) {
5026 pg_data_t
*pgdat
= NODE_DATA(nid
);
5027 free_area_init_node(nid
, NULL
,
5028 find_min_pfn_for_node(nid
), NULL
);
5030 /* Any memory on that node */
5031 if (pgdat
->node_present_pages
)
5032 node_set_state(nid
, N_MEMORY
);
5033 check_for_memory(pgdat
, nid
);
5037 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
5039 unsigned long long coremem
;
5043 coremem
= memparse(p
, &p
);
5044 *core
= coremem
>> PAGE_SHIFT
;
5046 /* Paranoid check that UL is enough for the coremem value */
5047 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
5053 * kernelcore=size sets the amount of memory for use for allocations that
5054 * cannot be reclaimed or migrated.
5056 static int __init
cmdline_parse_kernelcore(char *p
)
5058 return cmdline_parse_core(p
, &required_kernelcore
);
5062 * movablecore=size sets the amount of memory for use for allocations that
5063 * can be reclaimed or migrated.
5065 static int __init
cmdline_parse_movablecore(char *p
)
5067 return cmdline_parse_core(p
, &required_movablecore
);
5070 early_param("kernelcore", cmdline_parse_kernelcore
);
5071 early_param("movablecore", cmdline_parse_movablecore
);
5073 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5076 * set_dma_reserve - set the specified number of pages reserved in the first zone
5077 * @new_dma_reserve: The number of pages to mark reserved
5079 * The per-cpu batchsize and zone watermarks are determined by present_pages.
5080 * In the DMA zone, a significant percentage may be consumed by kernel image
5081 * and other unfreeable allocations which can skew the watermarks badly. This
5082 * function may optionally be used to account for unfreeable pages in the
5083 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
5084 * smaller per-cpu batchsize.
5086 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
5088 dma_reserve
= new_dma_reserve
;
5091 void __init
free_area_init(unsigned long *zones_size
)
5093 free_area_init_node(0, zones_size
,
5094 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
5097 static int page_alloc_cpu_notify(struct notifier_block
*self
,
5098 unsigned long action
, void *hcpu
)
5100 int cpu
= (unsigned long)hcpu
;
5102 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
5103 lru_add_drain_cpu(cpu
);
5107 * Spill the event counters of the dead processor
5108 * into the current processors event counters.
5109 * This artificially elevates the count of the current
5112 vm_events_fold_cpu(cpu
);
5115 * Zero the differential counters of the dead processor
5116 * so that the vm statistics are consistent.
5118 * This is only okay since the processor is dead and cannot
5119 * race with what we are doing.
5121 refresh_cpu_vm_stats(cpu
);
5126 void __init
page_alloc_init(void)
5128 hotcpu_notifier(page_alloc_cpu_notify
, 0);
5132 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
5133 * or min_free_kbytes changes.
5135 static void calculate_totalreserve_pages(void)
5137 struct pglist_data
*pgdat
;
5138 unsigned long reserve_pages
= 0;
5139 enum zone_type i
, j
;
5141 for_each_online_pgdat(pgdat
) {
5142 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5143 struct zone
*zone
= pgdat
->node_zones
+ i
;
5144 unsigned long max
= 0;
5146 /* Find valid and maximum lowmem_reserve in the zone */
5147 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
5148 if (zone
->lowmem_reserve
[j
] > max
)
5149 max
= zone
->lowmem_reserve
[j
];
5152 /* we treat the high watermark as reserved pages. */
5153 max
+= high_wmark_pages(zone
);
5155 if (max
> zone
->present_pages
)
5156 max
= zone
->present_pages
;
5157 reserve_pages
+= max
;
5159 * Lowmem reserves are not available to
5160 * GFP_HIGHUSER page cache allocations and
5161 * kswapd tries to balance zones to their high
5162 * watermark. As a result, neither should be
5163 * regarded as dirtyable memory, to prevent a
5164 * situation where reclaim has to clean pages
5165 * in order to balance the zones.
5167 zone
->dirty_balance_reserve
= max
;
5170 dirty_balance_reserve
= reserve_pages
;
5171 totalreserve_pages
= reserve_pages
;
5175 * setup_per_zone_lowmem_reserve - called whenever
5176 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
5177 * has a correct pages reserved value, so an adequate number of
5178 * pages are left in the zone after a successful __alloc_pages().
5180 static void setup_per_zone_lowmem_reserve(void)
5182 struct pglist_data
*pgdat
;
5183 enum zone_type j
, idx
;
5185 for_each_online_pgdat(pgdat
) {
5186 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5187 struct zone
*zone
= pgdat
->node_zones
+ j
;
5188 unsigned long present_pages
= zone
->present_pages
;
5190 zone
->lowmem_reserve
[j
] = 0;
5194 struct zone
*lower_zone
;
5198 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
5199 sysctl_lowmem_reserve_ratio
[idx
] = 1;
5201 lower_zone
= pgdat
->node_zones
+ idx
;
5202 lower_zone
->lowmem_reserve
[j
] = present_pages
/
5203 sysctl_lowmem_reserve_ratio
[idx
];
5204 present_pages
+= lower_zone
->present_pages
;
5209 /* update totalreserve_pages */
5210 calculate_totalreserve_pages();
5213 static void __setup_per_zone_wmarks(void)
5215 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
5216 unsigned long lowmem_pages
= 0;
5218 unsigned long flags
;
5220 /* Calculate total number of !ZONE_HIGHMEM pages */
5221 for_each_zone(zone
) {
5222 if (!is_highmem(zone
))
5223 lowmem_pages
+= zone
->present_pages
;
5226 for_each_zone(zone
) {
5229 spin_lock_irqsave(&zone
->lock
, flags
);
5230 tmp
= (u64
)pages_min
* zone
->present_pages
;
5231 do_div(tmp
, lowmem_pages
);
5232 if (is_highmem(zone
)) {
5234 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
5235 * need highmem pages, so cap pages_min to a small
5238 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
5239 * deltas controls asynch page reclaim, and so should
5240 * not be capped for highmem.
5244 min_pages
= zone
->present_pages
/ 1024;
5245 if (min_pages
< SWAP_CLUSTER_MAX
)
5246 min_pages
= SWAP_CLUSTER_MAX
;
5247 if (min_pages
> 128)
5249 zone
->watermark
[WMARK_MIN
] = min_pages
;
5252 * If it's a lowmem zone, reserve a number of pages
5253 * proportionate to the zone's size.
5255 zone
->watermark
[WMARK_MIN
] = tmp
;
5258 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + (tmp
>> 2);
5259 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + (tmp
>> 1);
5261 setup_zone_migrate_reserve(zone
);
5262 spin_unlock_irqrestore(&zone
->lock
, flags
);
5265 /* update totalreserve_pages */
5266 calculate_totalreserve_pages();
5270 * setup_per_zone_wmarks - called when min_free_kbytes changes
5271 * or when memory is hot-{added|removed}
5273 * Ensures that the watermark[min,low,high] values for each zone are set
5274 * correctly with respect to min_free_kbytes.
5276 void setup_per_zone_wmarks(void)
5278 mutex_lock(&zonelists_mutex
);
5279 __setup_per_zone_wmarks();
5280 mutex_unlock(&zonelists_mutex
);
5284 * The inactive anon list should be small enough that the VM never has to
5285 * do too much work, but large enough that each inactive page has a chance
5286 * to be referenced again before it is swapped out.
5288 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
5289 * INACTIVE_ANON pages on this zone's LRU, maintained by the
5290 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
5291 * the anonymous pages are kept on the inactive list.
5294 * memory ratio inactive anon
5295 * -------------------------------------
5304 static void __meminit
calculate_zone_inactive_ratio(struct zone
*zone
)
5306 unsigned int gb
, ratio
;
5308 /* Zone size in gigabytes */
5309 gb
= zone
->present_pages
>> (30 - PAGE_SHIFT
);
5311 ratio
= int_sqrt(10 * gb
);
5315 zone
->inactive_ratio
= ratio
;
5318 static void __meminit
setup_per_zone_inactive_ratio(void)
5323 calculate_zone_inactive_ratio(zone
);
5327 * Initialise min_free_kbytes.
5329 * For small machines we want it small (128k min). For large machines
5330 * we want it large (64MB max). But it is not linear, because network
5331 * bandwidth does not increase linearly with machine size. We use
5333 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
5334 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
5350 int __meminit
init_per_zone_wmark_min(void)
5352 unsigned long lowmem_kbytes
;
5354 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
5356 min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
5357 if (min_free_kbytes
< 128)
5358 min_free_kbytes
= 128;
5359 if (min_free_kbytes
> 65536)
5360 min_free_kbytes
= 65536;
5361 setup_per_zone_wmarks();
5362 refresh_zone_stat_thresholds();
5363 setup_per_zone_lowmem_reserve();
5364 setup_per_zone_inactive_ratio();
5367 module_init(init_per_zone_wmark_min
)
5370 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
5371 * that we can call two helper functions whenever min_free_kbytes
5374 int min_free_kbytes_sysctl_handler(ctl_table
*table
, int write
,
5375 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5377 proc_dointvec(table
, write
, buffer
, length
, ppos
);
5379 setup_per_zone_wmarks();
5384 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table
*table
, int write
,
5385 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5390 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5395 zone
->min_unmapped_pages
= (zone
->present_pages
*
5396 sysctl_min_unmapped_ratio
) / 100;
5400 int sysctl_min_slab_ratio_sysctl_handler(ctl_table
*table
, int write
,
5401 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5406 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5411 zone
->min_slab_pages
= (zone
->present_pages
*
5412 sysctl_min_slab_ratio
) / 100;
5418 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
5419 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
5420 * whenever sysctl_lowmem_reserve_ratio changes.
5422 * The reserve ratio obviously has absolutely no relation with the
5423 * minimum watermarks. The lowmem reserve ratio can only make sense
5424 * if in function of the boot time zone sizes.
5426 int lowmem_reserve_ratio_sysctl_handler(ctl_table
*table
, int write
,
5427 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5429 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5430 setup_per_zone_lowmem_reserve();
5435 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
5436 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
5437 * can have before it gets flushed back to buddy allocator.
5440 int percpu_pagelist_fraction_sysctl_handler(ctl_table
*table
, int write
,
5441 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
5447 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
5448 if (!write
|| (ret
< 0))
5450 for_each_populated_zone(zone
) {
5451 for_each_possible_cpu(cpu
) {
5453 high
= zone
->present_pages
/ percpu_pagelist_fraction
;
5454 setup_pagelist_highmark(
5455 per_cpu_ptr(zone
->pageset
, cpu
), high
);
5461 int hashdist
= HASHDIST_DEFAULT
;
5464 static int __init
set_hashdist(char *str
)
5468 hashdist
= simple_strtoul(str
, &str
, 0);
5471 __setup("hashdist=", set_hashdist
);
5475 * allocate a large system hash table from bootmem
5476 * - it is assumed that the hash table must contain an exact power-of-2
5477 * quantity of entries
5478 * - limit is the number of hash buckets, not the total allocation size
5480 void *__init
alloc_large_system_hash(const char *tablename
,
5481 unsigned long bucketsize
,
5482 unsigned long numentries
,
5485 unsigned int *_hash_shift
,
5486 unsigned int *_hash_mask
,
5487 unsigned long low_limit
,
5488 unsigned long high_limit
)
5490 unsigned long long max
= high_limit
;
5491 unsigned long log2qty
, size
;
5494 /* allow the kernel cmdline to have a say */
5496 /* round applicable memory size up to nearest megabyte */
5497 numentries
= nr_kernel_pages
;
5498 numentries
+= (1UL << (20 - PAGE_SHIFT
)) - 1;
5499 numentries
>>= 20 - PAGE_SHIFT
;
5500 numentries
<<= 20 - PAGE_SHIFT
;
5502 /* limit to 1 bucket per 2^scale bytes of low memory */
5503 if (scale
> PAGE_SHIFT
)
5504 numentries
>>= (scale
- PAGE_SHIFT
);
5506 numentries
<<= (PAGE_SHIFT
- scale
);
5508 /* Make sure we've got at least a 0-order allocation.. */
5509 if (unlikely(flags
& HASH_SMALL
)) {
5510 /* Makes no sense without HASH_EARLY */
5511 WARN_ON(!(flags
& HASH_EARLY
));
5512 if (!(numentries
>> *_hash_shift
)) {
5513 numentries
= 1UL << *_hash_shift
;
5514 BUG_ON(!numentries
);
5516 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
5517 numentries
= PAGE_SIZE
/ bucketsize
;
5519 numentries
= roundup_pow_of_two(numentries
);
5521 /* limit allocation size to 1/16 total memory by default */
5523 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
5524 do_div(max
, bucketsize
);
5526 max
= min(max
, 0x80000000ULL
);
5528 if (numentries
< low_limit
)
5529 numentries
= low_limit
;
5530 if (numentries
> max
)
5533 log2qty
= ilog2(numentries
);
5536 size
= bucketsize
<< log2qty
;
5537 if (flags
& HASH_EARLY
)
5538 table
= alloc_bootmem_nopanic(size
);
5540 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
5543 * If bucketsize is not a power-of-two, we may free
5544 * some pages at the end of hash table which
5545 * alloc_pages_exact() automatically does
5547 if (get_order(size
) < MAX_ORDER
) {
5548 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
5549 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
5552 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
5555 panic("Failed to allocate %s hash table\n", tablename
);
5557 printk(KERN_INFO
"%s hash table entries: %ld (order: %d, %lu bytes)\n",
5560 ilog2(size
) - PAGE_SHIFT
,
5564 *_hash_shift
= log2qty
;
5566 *_hash_mask
= (1 << log2qty
) - 1;
5571 /* Return a pointer to the bitmap storing bits affecting a block of pages */
5572 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
5575 #ifdef CONFIG_SPARSEMEM
5576 return __pfn_to_section(pfn
)->pageblock_flags
;
5578 return zone
->pageblock_flags
;
5579 #endif /* CONFIG_SPARSEMEM */
5582 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
5584 #ifdef CONFIG_SPARSEMEM
5585 pfn
&= (PAGES_PER_SECTION
-1);
5586 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5588 pfn
= pfn
- zone
->zone_start_pfn
;
5589 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
5590 #endif /* CONFIG_SPARSEMEM */
5594 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5595 * @page: The page within the block of interest
5596 * @start_bitidx: The first bit of interest to retrieve
5597 * @end_bitidx: The last bit of interest
5598 * returns pageblock_bits flags
5600 unsigned long get_pageblock_flags_group(struct page
*page
,
5601 int start_bitidx
, int end_bitidx
)
5604 unsigned long *bitmap
;
5605 unsigned long pfn
, bitidx
;
5606 unsigned long flags
= 0;
5607 unsigned long value
= 1;
5609 zone
= page_zone(page
);
5610 pfn
= page_to_pfn(page
);
5611 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5612 bitidx
= pfn_to_bitidx(zone
, pfn
);
5614 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5615 if (test_bit(bitidx
+ start_bitidx
, bitmap
))
5622 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5623 * @page: The page within the block of interest
5624 * @start_bitidx: The first bit of interest
5625 * @end_bitidx: The last bit of interest
5626 * @flags: The flags to set
5628 void set_pageblock_flags_group(struct page
*page
, unsigned long flags
,
5629 int start_bitidx
, int end_bitidx
)
5632 unsigned long *bitmap
;
5633 unsigned long pfn
, bitidx
;
5634 unsigned long value
= 1;
5636 zone
= page_zone(page
);
5637 pfn
= page_to_pfn(page
);
5638 bitmap
= get_pageblock_bitmap(zone
, pfn
);
5639 bitidx
= pfn_to_bitidx(zone
, pfn
);
5640 VM_BUG_ON(pfn
< zone
->zone_start_pfn
);
5641 VM_BUG_ON(pfn
>= zone
->zone_start_pfn
+ zone
->spanned_pages
);
5643 for (; start_bitidx
<= end_bitidx
; start_bitidx
++, value
<<= 1)
5645 __set_bit(bitidx
+ start_bitidx
, bitmap
);
5647 __clear_bit(bitidx
+ start_bitidx
, bitmap
);
5651 * This function checks whether pageblock includes unmovable pages or not.
5652 * If @count is not zero, it is okay to include less @count unmovable pages
5654 * PageLRU check wihtout isolation or lru_lock could race so that
5655 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
5656 * expect this function should be exact.
5658 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
5659 bool skip_hwpoisoned_pages
)
5661 unsigned long pfn
, iter
, found
;
5665 * For avoiding noise data, lru_add_drain_all() should be called
5666 * If ZONE_MOVABLE, the zone never contains unmovable pages
5668 if (zone_idx(zone
) == ZONE_MOVABLE
)
5670 mt
= get_pageblock_migratetype(page
);
5671 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
5674 pfn
= page_to_pfn(page
);
5675 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
5676 unsigned long check
= pfn
+ iter
;
5678 if (!pfn_valid_within(check
))
5681 page
= pfn_to_page(check
);
5683 * We can't use page_count without pin a page
5684 * because another CPU can free compound page.
5685 * This check already skips compound tails of THP
5686 * because their page->_count is zero at all time.
5688 if (!atomic_read(&page
->_count
)) {
5689 if (PageBuddy(page
))
5690 iter
+= (1 << page_order(page
)) - 1;
5695 * The HWPoisoned page may be not in buddy system, and
5696 * page_count() is not 0.
5698 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
5704 * If there are RECLAIMABLE pages, we need to check it.
5705 * But now, memory offline itself doesn't call shrink_slab()
5706 * and it still to be fixed.
5709 * If the page is not RAM, page_count()should be 0.
5710 * we don't need more check. This is an _used_ not-movable page.
5712 * The problematic thing here is PG_reserved pages. PG_reserved
5713 * is set to both of a memory hole page and a _used_ kernel
5722 bool is_pageblock_removable_nolock(struct page
*page
)
5728 * We have to be careful here because we are iterating over memory
5729 * sections which are not zone aware so we might end up outside of
5730 * the zone but still within the section.
5731 * We have to take care about the node as well. If the node is offline
5732 * its NODE_DATA will be NULL - see page_zone.
5734 if (!node_online(page_to_nid(page
)))
5737 zone
= page_zone(page
);
5738 pfn
= page_to_pfn(page
);
5739 if (zone
->zone_start_pfn
> pfn
||
5740 zone
->zone_start_pfn
+ zone
->spanned_pages
<= pfn
)
5743 return !has_unmovable_pages(zone
, page
, 0, true);
5748 static unsigned long pfn_max_align_down(unsigned long pfn
)
5750 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
5751 pageblock_nr_pages
) - 1);
5754 static unsigned long pfn_max_align_up(unsigned long pfn
)
5756 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
5757 pageblock_nr_pages
));
5760 /* [start, end) must belong to a single zone. */
5761 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
5762 unsigned long start
, unsigned long end
)
5764 /* This function is based on compact_zone() from compaction.c. */
5765 unsigned long nr_reclaimed
;
5766 unsigned long pfn
= start
;
5767 unsigned int tries
= 0;
5772 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
5773 if (fatal_signal_pending(current
)) {
5778 if (list_empty(&cc
->migratepages
)) {
5779 cc
->nr_migratepages
= 0;
5780 pfn
= isolate_migratepages_range(cc
->zone
, cc
,
5787 } else if (++tries
== 5) {
5788 ret
= ret
< 0 ? ret
: -EBUSY
;
5792 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
5794 cc
->nr_migratepages
-= nr_reclaimed
;
5796 ret
= migrate_pages(&cc
->migratepages
,
5797 alloc_migrate_target
,
5798 0, false, MIGRATE_SYNC
,
5802 putback_movable_pages(&cc
->migratepages
);
5803 return ret
> 0 ? 0 : ret
;
5807 * alloc_contig_range() -- tries to allocate given range of pages
5808 * @start: start PFN to allocate
5809 * @end: one-past-the-last PFN to allocate
5810 * @migratetype: migratetype of the underlaying pageblocks (either
5811 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
5812 * in range must have the same migratetype and it must
5813 * be either of the two.
5815 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
5816 * aligned, however it's the caller's responsibility to guarantee that
5817 * we are the only thread that changes migrate type of pageblocks the
5820 * The PFN range must belong to a single zone.
5822 * Returns zero on success or negative error code. On success all
5823 * pages which PFN is in [start, end) are allocated for the caller and
5824 * need to be freed with free_contig_range().
5826 int alloc_contig_range(unsigned long start
, unsigned long end
,
5827 unsigned migratetype
)
5829 unsigned long outer_start
, outer_end
;
5832 struct compact_control cc
= {
5833 .nr_migratepages
= 0,
5835 .zone
= page_zone(pfn_to_page(start
)),
5837 .ignore_skip_hint
= true,
5839 INIT_LIST_HEAD(&cc
.migratepages
);
5842 * What we do here is we mark all pageblocks in range as
5843 * MIGRATE_ISOLATE. Because pageblock and max order pages may
5844 * have different sizes, and due to the way page allocator
5845 * work, we align the range to biggest of the two pages so
5846 * that page allocator won't try to merge buddies from
5847 * different pageblocks and change MIGRATE_ISOLATE to some
5848 * other migration type.
5850 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
5851 * migrate the pages from an unaligned range (ie. pages that
5852 * we are interested in). This will put all the pages in
5853 * range back to page allocator as MIGRATE_ISOLATE.
5855 * When this is done, we take the pages in range from page
5856 * allocator removing them from the buddy system. This way
5857 * page allocator will never consider using them.
5859 * This lets us mark the pageblocks back as
5860 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
5861 * aligned range but not in the unaligned, original range are
5862 * put back to page allocator so that buddy can use them.
5865 ret
= start_isolate_page_range(pfn_max_align_down(start
),
5866 pfn_max_align_up(end
), migratetype
,
5871 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
5876 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
5877 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
5878 * more, all pages in [start, end) are free in page allocator.
5879 * What we are going to do is to allocate all pages from
5880 * [start, end) (that is remove them from page allocator).
5882 * The only problem is that pages at the beginning and at the
5883 * end of interesting range may be not aligned with pages that
5884 * page allocator holds, ie. they can be part of higher order
5885 * pages. Because of this, we reserve the bigger range and
5886 * once this is done free the pages we are not interested in.
5888 * We don't have to hold zone->lock here because the pages are
5889 * isolated thus they won't get removed from buddy.
5892 lru_add_drain_all();
5896 outer_start
= start
;
5897 while (!PageBuddy(pfn_to_page(outer_start
))) {
5898 if (++order
>= MAX_ORDER
) {
5902 outer_start
&= ~0UL << order
;
5905 /* Make sure the range is really isolated. */
5906 if (test_pages_isolated(outer_start
, end
, false)) {
5907 pr_warn("alloc_contig_range test_pages_isolated(%lx, %lx) failed\n",
5914 /* Grab isolated pages from freelists. */
5915 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
5921 /* Free head and tail (if any) */
5922 if (start
!= outer_start
)
5923 free_contig_range(outer_start
, start
- outer_start
);
5924 if (end
!= outer_end
)
5925 free_contig_range(end
, outer_end
- end
);
5928 undo_isolate_page_range(pfn_max_align_down(start
),
5929 pfn_max_align_up(end
), migratetype
);
5933 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
5935 unsigned int count
= 0;
5937 for (; nr_pages
--; pfn
++) {
5938 struct page
*page
= pfn_to_page(pfn
);
5940 count
+= page_count(page
) != 1;
5943 WARN(count
!= 0, "%d pages are still in use!\n", count
);
5947 #ifdef CONFIG_MEMORY_HOTPLUG
5948 static int __meminit
__zone_pcp_update(void *data
)
5950 struct zone
*zone
= data
;
5952 unsigned long batch
= zone_batchsize(zone
), flags
;
5954 for_each_possible_cpu(cpu
) {
5955 struct per_cpu_pageset
*pset
;
5956 struct per_cpu_pages
*pcp
;
5958 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
5961 local_irq_save(flags
);
5963 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
5964 drain_zonestat(zone
, pset
);
5965 setup_pageset(pset
, batch
);
5966 local_irq_restore(flags
);
5971 void __meminit
zone_pcp_update(struct zone
*zone
)
5973 stop_machine(__zone_pcp_update
, zone
, NULL
);
5977 void zone_pcp_reset(struct zone
*zone
)
5979 unsigned long flags
;
5981 struct per_cpu_pageset
*pset
;
5983 /* avoid races with drain_pages() */
5984 local_irq_save(flags
);
5985 if (zone
->pageset
!= &boot_pageset
) {
5986 for_each_online_cpu(cpu
) {
5987 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
5988 drain_zonestat(zone
, pset
);
5990 free_percpu(zone
->pageset
);
5991 zone
->pageset
= &boot_pageset
;
5993 local_irq_restore(flags
);
5996 #ifdef CONFIG_MEMORY_HOTREMOVE
5998 * All pages in the range must be isolated before calling this.
6001 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
6007 unsigned long flags
;
6008 /* find the first valid pfn */
6009 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
6014 zone
= page_zone(pfn_to_page(pfn
));
6015 spin_lock_irqsave(&zone
->lock
, flags
);
6017 while (pfn
< end_pfn
) {
6018 if (!pfn_valid(pfn
)) {
6022 page
= pfn_to_page(pfn
);
6024 * The HWPoisoned page may be not in buddy system, and
6025 * page_count() is not 0.
6027 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
6029 SetPageReserved(page
);
6033 BUG_ON(page_count(page
));
6034 BUG_ON(!PageBuddy(page
));
6035 order
= page_order(page
);
6036 #ifdef CONFIG_DEBUG_VM
6037 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
6038 pfn
, 1 << order
, end_pfn
);
6040 list_del(&page
->lru
);
6041 rmv_page_order(page
);
6042 zone
->free_area
[order
].nr_free
--;
6043 for (i
= 0; i
< (1 << order
); i
++)
6044 SetPageReserved((page
+i
));
6045 pfn
+= (1 << order
);
6047 spin_unlock_irqrestore(&zone
->lock
, flags
);
6051 #ifdef CONFIG_MEMORY_FAILURE
6052 bool is_free_buddy_page(struct page
*page
)
6054 struct zone
*zone
= page_zone(page
);
6055 unsigned long pfn
= page_to_pfn(page
);
6056 unsigned long flags
;
6059 spin_lock_irqsave(&zone
->lock
, flags
);
6060 for (order
= 0; order
< MAX_ORDER
; order
++) {
6061 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
6063 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
6066 spin_unlock_irqrestore(&zone
->lock
, flags
);
6068 return order
< MAX_ORDER
;
6072 static const struct trace_print_flags pageflag_names
[] = {
6073 {1UL << PG_locked
, "locked" },
6074 {1UL << PG_error
, "error" },
6075 {1UL << PG_referenced
, "referenced" },
6076 {1UL << PG_uptodate
, "uptodate" },
6077 {1UL << PG_dirty
, "dirty" },
6078 {1UL << PG_lru
, "lru" },
6079 {1UL << PG_active
, "active" },
6080 {1UL << PG_slab
, "slab" },
6081 {1UL << PG_owner_priv_1
, "owner_priv_1" },
6082 {1UL << PG_arch_1
, "arch_1" },
6083 {1UL << PG_reserved
, "reserved" },
6084 {1UL << PG_private
, "private" },
6085 {1UL << PG_private_2
, "private_2" },
6086 {1UL << PG_writeback
, "writeback" },
6087 #ifdef CONFIG_PAGEFLAGS_EXTENDED
6088 {1UL << PG_head
, "head" },
6089 {1UL << PG_tail
, "tail" },
6091 {1UL << PG_compound
, "compound" },
6093 {1UL << PG_swapcache
, "swapcache" },
6094 {1UL << PG_mappedtodisk
, "mappedtodisk" },
6095 {1UL << PG_reclaim
, "reclaim" },
6096 {1UL << PG_swapbacked
, "swapbacked" },
6097 {1UL << PG_unevictable
, "unevictable" },
6099 {1UL << PG_mlocked
, "mlocked" },
6101 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
6102 {1UL << PG_uncached
, "uncached" },
6104 #ifdef CONFIG_MEMORY_FAILURE
6105 {1UL << PG_hwpoison
, "hwpoison" },
6107 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
6108 {1UL << PG_compound_lock
, "compound_lock" },
6112 static void dump_page_flags(unsigned long flags
)
6114 const char *delim
= "";
6118 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names
) != __NR_PAGEFLAGS
);
6120 printk(KERN_ALERT
"page flags: %#lx(", flags
);
6122 /* remove zone id */
6123 flags
&= (1UL << NR_PAGEFLAGS
) - 1;
6125 for (i
= 0; i
< ARRAY_SIZE(pageflag_names
) && flags
; i
++) {
6127 mask
= pageflag_names
[i
].mask
;
6128 if ((flags
& mask
) != mask
)
6132 printk("%s%s", delim
, pageflag_names
[i
].name
);
6136 /* check for left over flags */
6138 printk("%s%#lx", delim
, flags
);
6143 void dump_page(struct page
*page
)
6146 "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
6147 page
, atomic_read(&page
->_count
), page_mapcount(page
),
6148 page
->mapping
, page
->index
);
6149 dump_page_flags(page
->flags
);
6150 mem_cgroup_print_bad_page(page
);