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/kasan.h>
29 #include <linux/module.h>
30 #include <linux/suspend.h>
31 #include <linux/pagevec.h>
32 #include <linux/blkdev.h>
33 #include <linux/slab.h>
34 #include <linux/ratelimit.h>
35 #include <linux/oom.h>
36 #include <linux/notifier.h>
37 #include <linux/topology.h>
38 #include <linux/sysctl.h>
39 #include <linux/cpu.h>
40 #include <linux/cpuset.h>
41 #include <linux/memory_hotplug.h>
42 #include <linux/nodemask.h>
43 #include <linux/vmalloc.h>
44 #include <linux/vmstat.h>
45 #include <linux/mempolicy.h>
46 #include <linux/stop_machine.h>
47 #include <linux/sort.h>
48 #include <linux/pfn.h>
49 #include <linux/backing-dev.h>
50 #include <linux/fault-inject.h>
51 #include <linux/page-isolation.h>
52 #include <linux/page_ext.h>
53 #include <linux/debugobjects.h>
54 #include <linux/kmemleak.h>
55 #include <linux/compaction.h>
56 #include <trace/events/kmem.h>
57 #include <linux/prefetch.h>
58 #include <linux/mm_inline.h>
59 #include <linux/migrate.h>
60 #include <linux/page_ext.h>
61 #include <linux/hugetlb.h>
62 #include <linux/sched/rt.h>
63 #include <linux/page_owner.h>
64 #include <linux/kthread.h>
66 #include <asm/sections.h>
67 #include <asm/tlbflush.h>
68 #include <asm/div64.h>
71 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
72 static DEFINE_MUTEX(pcp_batch_high_lock
);
73 #define MIN_PERCPU_PAGELIST_FRACTION (8)
75 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
76 DEFINE_PER_CPU(int, numa_node
);
77 EXPORT_PER_CPU_SYMBOL(numa_node
);
80 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
82 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
83 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
84 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
85 * defined in <linux/topology.h>.
87 DEFINE_PER_CPU(int, _numa_mem_
); /* Kernel "local memory" node */
88 EXPORT_PER_CPU_SYMBOL(_numa_mem_
);
89 int _node_numa_mem_
[MAX_NUMNODES
];
93 * Array of node states.
95 nodemask_t node_states
[NR_NODE_STATES
] __read_mostly
= {
96 [N_POSSIBLE
] = NODE_MASK_ALL
,
97 [N_ONLINE
] = { { [0] = 1UL } },
99 [N_NORMAL_MEMORY
] = { { [0] = 1UL } },
100 #ifdef CONFIG_HIGHMEM
101 [N_HIGH_MEMORY
] = { { [0] = 1UL } },
103 #ifdef CONFIG_MOVABLE_NODE
104 [N_MEMORY
] = { { [0] = 1UL } },
106 [N_CPU
] = { { [0] = 1UL } },
109 EXPORT_SYMBOL(node_states
);
111 /* Protect totalram_pages and zone->managed_pages */
112 static DEFINE_SPINLOCK(managed_page_count_lock
);
114 unsigned long totalram_pages __read_mostly
;
115 unsigned long totalreserve_pages __read_mostly
;
116 unsigned long totalcma_pages __read_mostly
;
118 * When calculating the number of globally allowed dirty pages, there
119 * is a certain number of per-zone reserves that should not be
120 * considered dirtyable memory. This is the sum of those reserves
121 * over all existing zones that contribute dirtyable memory.
123 unsigned long dirty_balance_reserve __read_mostly
;
125 int percpu_pagelist_fraction
;
126 gfp_t gfp_allowed_mask __read_mostly
= GFP_BOOT_MASK
;
128 #ifdef CONFIG_PM_SLEEP
130 * The following functions are used by the suspend/hibernate code to temporarily
131 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
132 * while devices are suspended. To avoid races with the suspend/hibernate code,
133 * they should always be called with pm_mutex held (gfp_allowed_mask also should
134 * only be modified with pm_mutex held, unless the suspend/hibernate code is
135 * guaranteed not to run in parallel with that modification).
138 static gfp_t saved_gfp_mask
;
140 void pm_restore_gfp_mask(void)
142 WARN_ON(!mutex_is_locked(&pm_mutex
));
143 if (saved_gfp_mask
) {
144 gfp_allowed_mask
= saved_gfp_mask
;
149 void pm_restrict_gfp_mask(void)
151 WARN_ON(!mutex_is_locked(&pm_mutex
));
152 WARN_ON(saved_gfp_mask
);
153 saved_gfp_mask
= gfp_allowed_mask
;
154 gfp_allowed_mask
&= ~GFP_IOFS
;
157 bool pm_suspended_storage(void)
159 if ((gfp_allowed_mask
& GFP_IOFS
) == GFP_IOFS
)
163 #endif /* CONFIG_PM_SLEEP */
165 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
166 int pageblock_order __read_mostly
;
169 static void __free_pages_ok(struct page
*page
, unsigned int order
);
172 * results with 256, 32 in the lowmem_reserve sysctl:
173 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
174 * 1G machine -> (16M dma, 784M normal, 224M high)
175 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
176 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
177 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
179 * TBD: should special case ZONE_DMA32 machines here - in those we normally
180 * don't need any ZONE_NORMAL reservation
182 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
183 #ifdef CONFIG_ZONE_DMA
186 #ifdef CONFIG_ZONE_DMA32
189 #ifdef CONFIG_HIGHMEM
195 EXPORT_SYMBOL(totalram_pages
);
197 static char * const zone_names
[MAX_NR_ZONES
] = {
198 #ifdef CONFIG_ZONE_DMA
201 #ifdef CONFIG_ZONE_DMA32
205 #ifdef CONFIG_HIGHMEM
211 int min_free_kbytes
= 1024;
212 int user_min_free_kbytes
= -1;
214 static unsigned long __meminitdata nr_kernel_pages
;
215 static unsigned long __meminitdata nr_all_pages
;
216 static unsigned long __meminitdata dma_reserve
;
218 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
219 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
220 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
221 static unsigned long __initdata required_kernelcore
;
222 static unsigned long __initdata required_movablecore
;
223 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
225 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
227 EXPORT_SYMBOL(movable_zone
);
228 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
231 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
232 int nr_online_nodes __read_mostly
= 1;
233 EXPORT_SYMBOL(nr_node_ids
);
234 EXPORT_SYMBOL(nr_online_nodes
);
237 int page_group_by_mobility_disabled __read_mostly
;
239 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
240 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
242 pgdat
->first_deferred_pfn
= ULONG_MAX
;
245 /* Returns true if the struct page for the pfn is uninitialised */
246 static inline bool __meminit
early_page_uninitialised(unsigned long pfn
)
248 if (pfn
>= NODE_DATA(early_pfn_to_nid(pfn
))->first_deferred_pfn
)
254 static inline bool early_page_nid_uninitialised(unsigned long pfn
, int nid
)
256 if (pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
263 * Returns false when the remaining initialisation should be deferred until
264 * later in the boot cycle when it can be parallelised.
266 static inline bool update_defer_init(pg_data_t
*pgdat
,
267 unsigned long pfn
, unsigned long zone_end
,
268 unsigned long *nr_initialised
)
270 /* Always populate low zones for address-contrained allocations */
271 if (zone_end
< pgdat_end_pfn(pgdat
))
274 /* Initialise at least 2G of the highest zone */
276 if (*nr_initialised
> (2UL << (30 - PAGE_SHIFT
)) &&
277 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
278 pgdat
->first_deferred_pfn
= pfn
;
285 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
289 static inline bool early_page_uninitialised(unsigned long pfn
)
294 static inline bool early_page_nid_uninitialised(unsigned long pfn
, int nid
)
299 static inline bool update_defer_init(pg_data_t
*pgdat
,
300 unsigned long pfn
, unsigned long zone_end
,
301 unsigned long *nr_initialised
)
308 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
310 if (unlikely(page_group_by_mobility_disabled
&&
311 migratetype
< MIGRATE_PCPTYPES
))
312 migratetype
= MIGRATE_UNMOVABLE
;
314 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
315 PB_migrate
, PB_migrate_end
);
318 #ifdef CONFIG_DEBUG_VM
319 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
323 unsigned long pfn
= page_to_pfn(page
);
324 unsigned long sp
, start_pfn
;
327 seq
= zone_span_seqbegin(zone
);
328 start_pfn
= zone
->zone_start_pfn
;
329 sp
= zone
->spanned_pages
;
330 if (!zone_spans_pfn(zone
, pfn
))
332 } while (zone_span_seqretry(zone
, seq
));
335 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
336 pfn
, zone_to_nid(zone
), zone
->name
,
337 start_pfn
, start_pfn
+ sp
);
342 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
344 if (!pfn_valid_within(page_to_pfn(page
)))
346 if (zone
!= page_zone(page
))
352 * Temporary debugging check for pages not lying within a given zone.
354 static int bad_range(struct zone
*zone
, struct page
*page
)
356 if (page_outside_zone_boundaries(zone
, page
))
358 if (!page_is_consistent(zone
, page
))
364 static inline int bad_range(struct zone
*zone
, struct page
*page
)
370 static void bad_page(struct page
*page
, const char *reason
,
371 unsigned long bad_flags
)
373 static unsigned long resume
;
374 static unsigned long nr_shown
;
375 static unsigned long nr_unshown
;
377 /* Don't complain about poisoned pages */
378 if (PageHWPoison(page
)) {
379 page_mapcount_reset(page
); /* remove PageBuddy */
384 * Allow a burst of 60 reports, then keep quiet for that minute;
385 * or allow a steady drip of one report per second.
387 if (nr_shown
== 60) {
388 if (time_before(jiffies
, resume
)) {
394 "BUG: Bad page state: %lu messages suppressed\n",
401 resume
= jiffies
+ 60 * HZ
;
403 printk(KERN_ALERT
"BUG: Bad page state in process %s pfn:%05lx\n",
404 current
->comm
, page_to_pfn(page
));
405 dump_page_badflags(page
, reason
, bad_flags
);
410 /* Leave bad fields for debug, except PageBuddy could make trouble */
411 page_mapcount_reset(page
); /* remove PageBuddy */
412 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
416 * Higher-order pages are called "compound pages". They are structured thusly:
418 * The first PAGE_SIZE page is called the "head page".
420 * The remaining PAGE_SIZE pages are called "tail pages".
422 * All pages have PG_compound set. All tail pages have their ->first_page
423 * pointing at the head page.
425 * The first tail page's ->lru.next holds the address of the compound page's
426 * put_page() function. Its ->lru.prev holds the order of allocation.
427 * This usage means that zero-order pages may not be compound.
430 static void free_compound_page(struct page
*page
)
432 __free_pages_ok(page
, compound_order(page
));
435 void prep_compound_page(struct page
*page
, unsigned long order
)
438 int nr_pages
= 1 << order
;
440 set_compound_page_dtor(page
, free_compound_page
);
441 set_compound_order(page
, order
);
443 for (i
= 1; i
< nr_pages
; i
++) {
444 struct page
*p
= page
+ i
;
445 set_page_count(p
, 0);
446 p
->first_page
= page
;
447 /* Make sure p->first_page is always valid for PageTail() */
453 #ifdef CONFIG_DEBUG_PAGEALLOC
454 unsigned int _debug_guardpage_minorder
;
455 bool _debug_pagealloc_enabled __read_mostly
;
456 bool _debug_guardpage_enabled __read_mostly
;
458 static int __init
early_debug_pagealloc(char *buf
)
463 if (strcmp(buf
, "on") == 0)
464 _debug_pagealloc_enabled
= true;
468 early_param("debug_pagealloc", early_debug_pagealloc
);
470 static bool need_debug_guardpage(void)
472 /* If we don't use debug_pagealloc, we don't need guard page */
473 if (!debug_pagealloc_enabled())
479 static void init_debug_guardpage(void)
481 if (!debug_pagealloc_enabled())
484 _debug_guardpage_enabled
= true;
487 struct page_ext_operations debug_guardpage_ops
= {
488 .need
= need_debug_guardpage
,
489 .init
= init_debug_guardpage
,
492 static int __init
debug_guardpage_minorder_setup(char *buf
)
496 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
497 printk(KERN_ERR
"Bad debug_guardpage_minorder value\n");
500 _debug_guardpage_minorder
= res
;
501 printk(KERN_INFO
"Setting debug_guardpage_minorder to %lu\n", res
);
504 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
506 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
507 unsigned int order
, int migratetype
)
509 struct page_ext
*page_ext
;
511 if (!debug_guardpage_enabled())
514 page_ext
= lookup_page_ext(page
);
515 __set_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
517 INIT_LIST_HEAD(&page
->lru
);
518 set_page_private(page
, order
);
519 /* Guard pages are not available for any usage */
520 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
523 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
524 unsigned int order
, int migratetype
)
526 struct page_ext
*page_ext
;
528 if (!debug_guardpage_enabled())
531 page_ext
= lookup_page_ext(page
);
532 __clear_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
534 set_page_private(page
, 0);
535 if (!is_migrate_isolate(migratetype
))
536 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
539 struct page_ext_operations debug_guardpage_ops
= { NULL
, };
540 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
541 unsigned int order
, int migratetype
) {}
542 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
543 unsigned int order
, int migratetype
) {}
546 static inline void set_page_order(struct page
*page
, unsigned int order
)
548 set_page_private(page
, order
);
549 __SetPageBuddy(page
);
552 static inline void rmv_page_order(struct page
*page
)
554 __ClearPageBuddy(page
);
555 set_page_private(page
, 0);
559 * This function checks whether a page is free && is the buddy
560 * we can do coalesce a page and its buddy if
561 * (a) the buddy is not in a hole &&
562 * (b) the buddy is in the buddy system &&
563 * (c) a page and its buddy have the same order &&
564 * (d) a page and its buddy are in the same zone.
566 * For recording whether a page is in the buddy system, we set ->_mapcount
567 * PAGE_BUDDY_MAPCOUNT_VALUE.
568 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
569 * serialized by zone->lock.
571 * For recording page's order, we use page_private(page).
573 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
576 if (!pfn_valid_within(page_to_pfn(buddy
)))
579 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
580 if (page_zone_id(page
) != page_zone_id(buddy
))
583 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
588 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
590 * zone check is done late to avoid uselessly
591 * calculating zone/node ids for pages that could
594 if (page_zone_id(page
) != page_zone_id(buddy
))
597 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
605 * Freeing function for a buddy system allocator.
607 * The concept of a buddy system is to maintain direct-mapped table
608 * (containing bit values) for memory blocks of various "orders".
609 * The bottom level table contains the map for the smallest allocatable
610 * units of memory (here, pages), and each level above it describes
611 * pairs of units from the levels below, hence, "buddies".
612 * At a high level, all that happens here is marking the table entry
613 * at the bottom level available, and propagating the changes upward
614 * as necessary, plus some accounting needed to play nicely with other
615 * parts of the VM system.
616 * At each level, we keep a list of pages, which are heads of continuous
617 * free pages of length of (1 << order) and marked with _mapcount
618 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
620 * So when we are allocating or freeing one, we can derive the state of the
621 * other. That is, if we allocate a small block, and both were
622 * free, the remainder of the region must be split into blocks.
623 * If a block is freed, and its buddy is also free, then this
624 * triggers coalescing into a block of larger size.
629 static inline void __free_one_page(struct page
*page
,
631 struct zone
*zone
, unsigned int order
,
634 unsigned long page_idx
;
635 unsigned long combined_idx
;
636 unsigned long uninitialized_var(buddy_idx
);
638 int max_order
= MAX_ORDER
;
640 VM_BUG_ON(!zone_is_initialized(zone
));
641 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
643 VM_BUG_ON(migratetype
== -1);
644 if (is_migrate_isolate(migratetype
)) {
646 * We restrict max order of merging to prevent merge
647 * between freepages on isolate pageblock and normal
648 * pageblock. Without this, pageblock isolation
649 * could cause incorrect freepage accounting.
651 max_order
= min(MAX_ORDER
, pageblock_order
+ 1);
653 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
656 page_idx
= pfn
& ((1 << max_order
) - 1);
658 VM_BUG_ON_PAGE(page_idx
& ((1 << order
) - 1), page
);
659 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
661 while (order
< max_order
- 1) {
662 buddy_idx
= __find_buddy_index(page_idx
, order
);
663 buddy
= page
+ (buddy_idx
- page_idx
);
664 if (!page_is_buddy(page
, buddy
, order
))
667 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
668 * merge with it and move up one order.
670 if (page_is_guard(buddy
)) {
671 clear_page_guard(zone
, buddy
, order
, migratetype
);
673 list_del(&buddy
->lru
);
674 zone
->free_area
[order
].nr_free
--;
675 rmv_page_order(buddy
);
677 combined_idx
= buddy_idx
& page_idx
;
678 page
= page
+ (combined_idx
- page_idx
);
679 page_idx
= combined_idx
;
682 set_page_order(page
, order
);
685 * If this is not the largest possible page, check if the buddy
686 * of the next-highest order is free. If it is, it's possible
687 * that pages are being freed that will coalesce soon. In case,
688 * that is happening, add the free page to the tail of the list
689 * so it's less likely to be used soon and more likely to be merged
690 * as a higher order page
692 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
693 struct page
*higher_page
, *higher_buddy
;
694 combined_idx
= buddy_idx
& page_idx
;
695 higher_page
= page
+ (combined_idx
- page_idx
);
696 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
697 higher_buddy
= higher_page
+ (buddy_idx
- combined_idx
);
698 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
699 list_add_tail(&page
->lru
,
700 &zone
->free_area
[order
].free_list
[migratetype
]);
705 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
707 zone
->free_area
[order
].nr_free
++;
710 static inline int free_pages_check(struct page
*page
)
712 const char *bad_reason
= NULL
;
713 unsigned long bad_flags
= 0;
715 if (unlikely(page_mapcount(page
)))
716 bad_reason
= "nonzero mapcount";
717 if (unlikely(page
->mapping
!= NULL
))
718 bad_reason
= "non-NULL mapping";
719 if (unlikely(atomic_read(&page
->_count
) != 0))
720 bad_reason
= "nonzero _count";
721 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
722 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
723 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
726 if (unlikely(page
->mem_cgroup
))
727 bad_reason
= "page still charged to cgroup";
729 if (unlikely(bad_reason
)) {
730 bad_page(page
, bad_reason
, bad_flags
);
733 page_cpupid_reset_last(page
);
734 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
735 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
740 * Frees a number of pages from the PCP lists
741 * Assumes all pages on list are in same zone, and of same order.
742 * count is the number of pages to free.
744 * If the zone was previously in an "all pages pinned" state then look to
745 * see if this freeing clears that state.
747 * And clear the zone's pages_scanned counter, to hold off the "all pages are
748 * pinned" detection logic.
750 static void free_pcppages_bulk(struct zone
*zone
, int count
,
751 struct per_cpu_pages
*pcp
)
756 unsigned long nr_scanned
;
758 spin_lock(&zone
->lock
);
759 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
761 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
765 struct list_head
*list
;
768 * Remove pages from lists in a round-robin fashion. A
769 * batch_free count is maintained that is incremented when an
770 * empty list is encountered. This is so more pages are freed
771 * off fuller lists instead of spinning excessively around empty
776 if (++migratetype
== MIGRATE_PCPTYPES
)
778 list
= &pcp
->lists
[migratetype
];
779 } while (list_empty(list
));
781 /* This is the only non-empty list. Free them all. */
782 if (batch_free
== MIGRATE_PCPTYPES
)
783 batch_free
= to_free
;
786 int mt
; /* migratetype of the to-be-freed page */
788 page
= list_entry(list
->prev
, struct page
, lru
);
789 /* must delete as __free_one_page list manipulates */
790 list_del(&page
->lru
);
791 mt
= get_freepage_migratetype(page
);
792 if (unlikely(has_isolate_pageblock(zone
)))
793 mt
= get_pageblock_migratetype(page
);
795 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
796 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
);
797 trace_mm_page_pcpu_drain(page
, 0, mt
);
798 } while (--to_free
&& --batch_free
&& !list_empty(list
));
800 spin_unlock(&zone
->lock
);
803 static void free_one_page(struct zone
*zone
,
804 struct page
*page
, unsigned long pfn
,
808 unsigned long nr_scanned
;
809 spin_lock(&zone
->lock
);
810 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
812 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
814 if (unlikely(has_isolate_pageblock(zone
) ||
815 is_migrate_isolate(migratetype
))) {
816 migratetype
= get_pfnblock_migratetype(page
, pfn
);
818 __free_one_page(page
, pfn
, zone
, order
, migratetype
);
819 spin_unlock(&zone
->lock
);
822 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
824 if (!IS_ENABLED(CONFIG_DEBUG_VM
))
826 if (unlikely(!PageTail(page
))) {
827 bad_page(page
, "PageTail not set", 0);
830 if (unlikely(page
->first_page
!= head_page
)) {
831 bad_page(page
, "first_page not consistent", 0);
837 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
838 unsigned long zone
, int nid
)
840 set_page_links(page
, zone
, nid
, pfn
);
841 init_page_count(page
);
842 page_mapcount_reset(page
);
843 page_cpupid_reset_last(page
);
845 INIT_LIST_HEAD(&page
->lru
);
846 #ifdef WANT_PAGE_VIRTUAL
847 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
848 if (!is_highmem_idx(zone
))
849 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
853 static void __meminit
__init_single_pfn(unsigned long pfn
, unsigned long zone
,
856 return __init_single_page(pfn_to_page(pfn
), pfn
, zone
, nid
);
859 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
860 static void init_reserved_page(unsigned long pfn
)
865 if (!early_page_uninitialised(pfn
))
868 nid
= early_pfn_to_nid(pfn
);
869 pgdat
= NODE_DATA(nid
);
871 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
872 struct zone
*zone
= &pgdat
->node_zones
[zid
];
874 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
877 __init_single_pfn(pfn
, zid
, nid
);
880 static inline void init_reserved_page(unsigned long pfn
)
883 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
886 * Initialised pages do not have PageReserved set. This function is
887 * called for each range allocated by the bootmem allocator and
888 * marks the pages PageReserved. The remaining valid pages are later
889 * sent to the buddy page allocator.
891 void __meminit
reserve_bootmem_region(unsigned long start
, unsigned long end
)
893 unsigned long start_pfn
= PFN_DOWN(start
);
894 unsigned long end_pfn
= PFN_UP(end
);
896 for (; start_pfn
< end_pfn
; start_pfn
++) {
897 if (pfn_valid(start_pfn
)) {
898 struct page
*page
= pfn_to_page(start_pfn
);
900 init_reserved_page(start_pfn
);
901 SetPageReserved(page
);
906 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
908 bool compound
= PageCompound(page
);
911 VM_BUG_ON_PAGE(PageTail(page
), page
);
912 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
914 trace_mm_page_free(page
, order
);
915 kmemcheck_free_shadow(page
, order
);
916 kasan_free_pages(page
, order
);
919 page
->mapping
= NULL
;
920 bad
+= free_pages_check(page
);
921 for (i
= 1; i
< (1 << order
); i
++) {
923 bad
+= free_tail_pages_check(page
, page
+ i
);
924 bad
+= free_pages_check(page
+ i
);
929 reset_page_owner(page
, order
);
931 if (!PageHighMem(page
)) {
932 debug_check_no_locks_freed(page_address(page
),
934 debug_check_no_obj_freed(page_address(page
),
937 arch_free_page(page
, order
);
938 kernel_map_pages(page
, 1 << order
, 0);
943 static void __free_pages_ok(struct page
*page
, unsigned int order
)
947 unsigned long pfn
= page_to_pfn(page
);
949 if (!free_pages_prepare(page
, order
))
952 migratetype
= get_pfnblock_migratetype(page
, pfn
);
953 local_irq_save(flags
);
954 __count_vm_events(PGFREE
, 1 << order
);
955 set_freepage_migratetype(page
, migratetype
);
956 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
957 local_irq_restore(flags
);
960 static void __init
__free_pages_boot_core(struct page
*page
,
961 unsigned long pfn
, unsigned int order
)
963 unsigned int nr_pages
= 1 << order
;
964 struct page
*p
= page
;
968 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
970 __ClearPageReserved(p
);
971 set_page_count(p
, 0);
973 __ClearPageReserved(p
);
974 set_page_count(p
, 0);
976 page_zone(page
)->managed_pages
+= nr_pages
;
977 set_page_refcounted(page
);
978 __free_pages(page
, order
);
981 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
982 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
984 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
986 int __meminit
early_pfn_to_nid(unsigned long pfn
)
988 static DEFINE_SPINLOCK(early_pfn_lock
);
991 spin_lock(&early_pfn_lock
);
992 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
995 spin_unlock(&early_pfn_lock
);
1001 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1002 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1003 struct mminit_pfnnid_cache
*state
)
1007 nid
= __early_pfn_to_nid(pfn
, state
);
1008 if (nid
>= 0 && nid
!= node
)
1013 /* Only safe to use early in boot when initialisation is single-threaded */
1014 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1016 return meminit_pfn_in_nid(pfn
, node
, &early_pfnnid_cache
);
1021 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1025 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1026 struct mminit_pfnnid_cache
*state
)
1033 void __init
__free_pages_bootmem(struct page
*page
, unsigned long pfn
,
1036 if (early_page_uninitialised(pfn
))
1038 return __free_pages_boot_core(page
, pfn
, order
);
1041 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1042 static void __init
deferred_free_range(struct page
*page
,
1043 unsigned long pfn
, int nr_pages
)
1050 /* Free a large naturally-aligned chunk if possible */
1051 if (nr_pages
== MAX_ORDER_NR_PAGES
&&
1052 (pfn
& (MAX_ORDER_NR_PAGES
-1)) == 0) {
1053 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1054 __free_pages_boot_core(page
, pfn
, MAX_ORDER
-1);
1058 for (i
= 0; i
< nr_pages
; i
++, page
++, pfn
++)
1059 __free_pages_boot_core(page
, pfn
, 0);
1062 /* Completion tracking for deferred_init_memmap() threads */
1063 static atomic_t pgdat_init_n_undone __initdata
;
1064 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1066 static inline void __init
pgdat_init_report_one_done(void)
1068 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1069 complete(&pgdat_init_all_done_comp
);
1072 /* Initialise remaining memory on a node */
1073 static int __init
deferred_init_memmap(void *data
)
1075 pg_data_t
*pgdat
= data
;
1076 int nid
= pgdat
->node_id
;
1077 struct mminit_pfnnid_cache nid_init_state
= { };
1078 unsigned long start
= jiffies
;
1079 unsigned long nr_pages
= 0;
1080 unsigned long walk_start
, walk_end
;
1083 unsigned long first_init_pfn
= pgdat
->first_deferred_pfn
;
1084 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1086 if (first_init_pfn
== ULONG_MAX
) {
1087 pgdat_init_report_one_done();
1091 /* Bind memory initialisation thread to a local node if possible */
1092 if (!cpumask_empty(cpumask
))
1093 set_cpus_allowed_ptr(current
, cpumask
);
1095 /* Sanity check boundaries */
1096 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1097 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1098 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1100 /* Only the highest zone is deferred so find it */
1101 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1102 zone
= pgdat
->node_zones
+ zid
;
1103 if (first_init_pfn
< zone_end_pfn(zone
))
1107 for_each_mem_pfn_range(i
, nid
, &walk_start
, &walk_end
, NULL
) {
1108 unsigned long pfn
, end_pfn
;
1109 struct page
*page
= NULL
;
1110 struct page
*free_base_page
= NULL
;
1111 unsigned long free_base_pfn
= 0;
1114 end_pfn
= min(walk_end
, zone_end_pfn(zone
));
1115 pfn
= first_init_pfn
;
1116 if (pfn
< walk_start
)
1118 if (pfn
< zone
->zone_start_pfn
)
1119 pfn
= zone
->zone_start_pfn
;
1121 for (; pfn
< end_pfn
; pfn
++) {
1122 if (!pfn_valid_within(pfn
))
1126 * Ensure pfn_valid is checked every
1127 * MAX_ORDER_NR_PAGES for memory holes
1129 if ((pfn
& (MAX_ORDER_NR_PAGES
- 1)) == 0) {
1130 if (!pfn_valid(pfn
)) {
1136 if (!meminit_pfn_in_nid(pfn
, nid
, &nid_init_state
)) {
1141 /* Minimise pfn page lookups and scheduler checks */
1142 if (page
&& (pfn
& (MAX_ORDER_NR_PAGES
- 1)) != 0) {
1145 nr_pages
+= nr_to_free
;
1146 deferred_free_range(free_base_page
,
1147 free_base_pfn
, nr_to_free
);
1148 free_base_page
= NULL
;
1149 free_base_pfn
= nr_to_free
= 0;
1151 page
= pfn_to_page(pfn
);
1156 VM_BUG_ON(page_zone(page
) != zone
);
1160 __init_single_page(page
, pfn
, zid
, nid
);
1161 if (!free_base_page
) {
1162 free_base_page
= page
;
1163 free_base_pfn
= pfn
;
1168 /* Where possible, batch up pages for a single free */
1171 /* Free the current block of pages to allocator */
1172 nr_pages
+= nr_to_free
;
1173 deferred_free_range(free_base_page
, free_base_pfn
,
1175 free_base_page
= NULL
;
1176 free_base_pfn
= nr_to_free
= 0;
1179 first_init_pfn
= max(end_pfn
, first_init_pfn
);
1182 /* Sanity check that the next zone really is unpopulated */
1183 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1185 pr_info("node %d initialised, %lu pages in %ums\n", nid
, nr_pages
,
1186 jiffies_to_msecs(jiffies
- start
));
1188 pgdat_init_report_one_done();
1192 void __init
page_alloc_init_late(void)
1196 /* There will be num_node_state(N_MEMORY) threads */
1197 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
1198 for_each_node_state(nid
, N_MEMORY
) {
1199 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
1202 /* Block until all are initialised */
1203 wait_for_completion(&pgdat_init_all_done_comp
);
1205 /* Reinit limits that are based on free pages after the kernel is up */
1206 files_maxfiles_init();
1208 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1211 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1212 void __init
init_cma_reserved_pageblock(struct page
*page
)
1214 unsigned i
= pageblock_nr_pages
;
1215 struct page
*p
= page
;
1218 __ClearPageReserved(p
);
1219 set_page_count(p
, 0);
1222 set_pageblock_migratetype(page
, MIGRATE_CMA
);
1224 if (pageblock_order
>= MAX_ORDER
) {
1225 i
= pageblock_nr_pages
;
1228 set_page_refcounted(p
);
1229 __free_pages(p
, MAX_ORDER
- 1);
1230 p
+= MAX_ORDER_NR_PAGES
;
1231 } while (i
-= MAX_ORDER_NR_PAGES
);
1233 set_page_refcounted(page
);
1234 __free_pages(page
, pageblock_order
);
1237 adjust_managed_page_count(page
, pageblock_nr_pages
);
1242 * The order of subdivision here is critical for the IO subsystem.
1243 * Please do not alter this order without good reasons and regression
1244 * testing. Specifically, as large blocks of memory are subdivided,
1245 * the order in which smaller blocks are delivered depends on the order
1246 * they're subdivided in this function. This is the primary factor
1247 * influencing the order in which pages are delivered to the IO
1248 * subsystem according to empirical testing, and this is also justified
1249 * by considering the behavior of a buddy system containing a single
1250 * large block of memory acted on by a series of small allocations.
1251 * This behavior is a critical factor in sglist merging's success.
1255 static inline void expand(struct zone
*zone
, struct page
*page
,
1256 int low
, int high
, struct free_area
*area
,
1259 unsigned long size
= 1 << high
;
1261 while (high
> low
) {
1265 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
1267 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC
) &&
1268 debug_guardpage_enabled() &&
1269 high
< debug_guardpage_minorder()) {
1271 * Mark as guard pages (or page), that will allow to
1272 * merge back to allocator when buddy will be freed.
1273 * Corresponding page table entries will not be touched,
1274 * pages will stay not present in virtual address space
1276 set_page_guard(zone
, &page
[size
], high
, migratetype
);
1279 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
1281 set_page_order(&page
[size
], high
);
1286 * This page is about to be returned from the page allocator
1288 static inline int check_new_page(struct page
*page
)
1290 const char *bad_reason
= NULL
;
1291 unsigned long bad_flags
= 0;
1293 if (unlikely(page_mapcount(page
)))
1294 bad_reason
= "nonzero mapcount";
1295 if (unlikely(page
->mapping
!= NULL
))
1296 bad_reason
= "non-NULL mapping";
1297 if (unlikely(atomic_read(&page
->_count
) != 0))
1298 bad_reason
= "nonzero _count";
1299 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
1300 bad_reason
= "HWPoisoned (hardware-corrupted)";
1301 bad_flags
= __PG_HWPOISON
;
1303 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
1304 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
1305 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
1308 if (unlikely(page
->mem_cgroup
))
1309 bad_reason
= "page still charged to cgroup";
1311 if (unlikely(bad_reason
)) {
1312 bad_page(page
, bad_reason
, bad_flags
);
1318 static int prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
1323 for (i
= 0; i
< (1 << order
); i
++) {
1324 struct page
*p
= page
+ i
;
1325 if (unlikely(check_new_page(p
)))
1329 set_page_private(page
, 0);
1330 set_page_refcounted(page
);
1332 arch_alloc_page(page
, order
);
1333 kernel_map_pages(page
, 1 << order
, 1);
1334 kasan_alloc_pages(page
, order
);
1336 if (gfp_flags
& __GFP_ZERO
)
1337 for (i
= 0; i
< (1 << order
); i
++)
1338 clear_highpage(page
+ i
);
1340 if (order
&& (gfp_flags
& __GFP_COMP
))
1341 prep_compound_page(page
, order
);
1343 set_page_owner(page
, order
, gfp_flags
);
1346 * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was necessary to
1347 * allocate the page. The expectation is that the caller is taking
1348 * steps that will free more memory. The caller should avoid the page
1349 * being used for !PFMEMALLOC purposes.
1351 page
->pfmemalloc
= !!(alloc_flags
& ALLOC_NO_WATERMARKS
);
1357 * Go through the free lists for the given migratetype and remove
1358 * the smallest available page from the freelists
1361 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
1364 unsigned int current_order
;
1365 struct free_area
*area
;
1368 /* Find a page of the appropriate size in the preferred list */
1369 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
1370 area
= &(zone
->free_area
[current_order
]);
1371 if (list_empty(&area
->free_list
[migratetype
]))
1374 page
= list_entry(area
->free_list
[migratetype
].next
,
1376 list_del(&page
->lru
);
1377 rmv_page_order(page
);
1379 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1380 set_freepage_migratetype(page
, migratetype
);
1389 * This array describes the order lists are fallen back to when
1390 * the free lists for the desirable migrate type are depleted
1392 static int fallbacks
[MIGRATE_TYPES
][4] = {
1393 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
1394 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
1395 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
1397 [MIGRATE_CMA
] = { MIGRATE_RESERVE
}, /* Never used */
1399 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
}, /* Never used */
1400 #ifdef CONFIG_MEMORY_ISOLATION
1401 [MIGRATE_ISOLATE
] = { MIGRATE_RESERVE
}, /* Never used */
1406 static struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1409 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
1412 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1413 unsigned int order
) { return NULL
; }
1417 * Move the free pages in a range to the free lists of the requested type.
1418 * Note that start_page and end_pages are not aligned on a pageblock
1419 * boundary. If alignment is required, use move_freepages_block()
1421 int move_freepages(struct zone
*zone
,
1422 struct page
*start_page
, struct page
*end_page
,
1426 unsigned long order
;
1427 int pages_moved
= 0;
1429 #ifndef CONFIG_HOLES_IN_ZONE
1431 * page_zone is not safe to call in this context when
1432 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1433 * anyway as we check zone boundaries in move_freepages_block().
1434 * Remove at a later date when no bug reports exist related to
1435 * grouping pages by mobility
1437 VM_BUG_ON(page_zone(start_page
) != page_zone(end_page
));
1440 for (page
= start_page
; page
<= end_page
;) {
1441 /* Make sure we are not inadvertently changing nodes */
1442 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
1444 if (!pfn_valid_within(page_to_pfn(page
))) {
1449 if (!PageBuddy(page
)) {
1454 order
= page_order(page
);
1455 list_move(&page
->lru
,
1456 &zone
->free_area
[order
].free_list
[migratetype
]);
1457 set_freepage_migratetype(page
, migratetype
);
1459 pages_moved
+= 1 << order
;
1465 int move_freepages_block(struct zone
*zone
, struct page
*page
,
1468 unsigned long start_pfn
, end_pfn
;
1469 struct page
*start_page
, *end_page
;
1471 start_pfn
= page_to_pfn(page
);
1472 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
1473 start_page
= pfn_to_page(start_pfn
);
1474 end_page
= start_page
+ pageblock_nr_pages
- 1;
1475 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
1477 /* Do not cross zone boundaries */
1478 if (!zone_spans_pfn(zone
, start_pfn
))
1480 if (!zone_spans_pfn(zone
, end_pfn
))
1483 return move_freepages(zone
, start_page
, end_page
, migratetype
);
1486 static void change_pageblock_range(struct page
*pageblock_page
,
1487 int start_order
, int migratetype
)
1489 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1491 while (nr_pageblocks
--) {
1492 set_pageblock_migratetype(pageblock_page
, migratetype
);
1493 pageblock_page
+= pageblock_nr_pages
;
1498 * When we are falling back to another migratetype during allocation, try to
1499 * steal extra free pages from the same pageblocks to satisfy further
1500 * allocations, instead of polluting multiple pageblocks.
1502 * If we are stealing a relatively large buddy page, it is likely there will
1503 * be more free pages in the pageblock, so try to steal them all. For
1504 * reclaimable and unmovable allocations, we steal regardless of page size,
1505 * as fragmentation caused by those allocations polluting movable pageblocks
1506 * is worse than movable allocations stealing from unmovable and reclaimable
1509 static bool can_steal_fallback(unsigned int order
, int start_mt
)
1512 * Leaving this order check is intended, although there is
1513 * relaxed order check in next check. The reason is that
1514 * we can actually steal whole pageblock if this condition met,
1515 * but, below check doesn't guarantee it and that is just heuristic
1516 * so could be changed anytime.
1518 if (order
>= pageblock_order
)
1521 if (order
>= pageblock_order
/ 2 ||
1522 start_mt
== MIGRATE_RECLAIMABLE
||
1523 start_mt
== MIGRATE_UNMOVABLE
||
1524 page_group_by_mobility_disabled
)
1531 * This function implements actual steal behaviour. If order is large enough,
1532 * we can steal whole pageblock. If not, we first move freepages in this
1533 * pageblock and check whether half of pages are moved or not. If half of
1534 * pages are moved, we can change migratetype of pageblock and permanently
1535 * use it's pages as requested migratetype in the future.
1537 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
1540 int current_order
= page_order(page
);
1543 /* Take ownership for orders >= pageblock_order */
1544 if (current_order
>= pageblock_order
) {
1545 change_pageblock_range(page
, current_order
, start_type
);
1549 pages
= move_freepages_block(zone
, page
, start_type
);
1551 /* Claim the whole block if over half of it is free */
1552 if (pages
>= (1 << (pageblock_order
-1)) ||
1553 page_group_by_mobility_disabled
)
1554 set_pageblock_migratetype(page
, start_type
);
1558 * Check whether there is a suitable fallback freepage with requested order.
1559 * If only_stealable is true, this function returns fallback_mt only if
1560 * we can steal other freepages all together. This would help to reduce
1561 * fragmentation due to mixed migratetype pages in one pageblock.
1563 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
1564 int migratetype
, bool only_stealable
, bool *can_steal
)
1569 if (area
->nr_free
== 0)
1574 fallback_mt
= fallbacks
[migratetype
][i
];
1575 if (fallback_mt
== MIGRATE_RESERVE
)
1578 if (list_empty(&area
->free_list
[fallback_mt
]))
1581 if (can_steal_fallback(order
, migratetype
))
1584 if (!only_stealable
)
1594 /* Remove an element from the buddy allocator from the fallback list */
1595 static inline struct page
*
1596 __rmqueue_fallback(struct zone
*zone
, unsigned int order
, int start_migratetype
)
1598 struct free_area
*area
;
1599 unsigned int current_order
;
1604 /* Find the largest possible block of pages in the other list */
1605 for (current_order
= MAX_ORDER
-1;
1606 current_order
>= order
&& current_order
<= MAX_ORDER
-1;
1608 area
= &(zone
->free_area
[current_order
]);
1609 fallback_mt
= find_suitable_fallback(area
, current_order
,
1610 start_migratetype
, false, &can_steal
);
1611 if (fallback_mt
== -1)
1614 page
= list_entry(area
->free_list
[fallback_mt
].next
,
1617 steal_suitable_fallback(zone
, page
, start_migratetype
);
1619 /* Remove the page from the freelists */
1621 list_del(&page
->lru
);
1622 rmv_page_order(page
);
1624 expand(zone
, page
, order
, current_order
, area
,
1627 * The freepage_migratetype may differ from pageblock's
1628 * migratetype depending on the decisions in
1629 * try_to_steal_freepages(). This is OK as long as it
1630 * does not differ for MIGRATE_CMA pageblocks. For CMA
1631 * we need to make sure unallocated pages flushed from
1632 * pcp lists are returned to the correct freelist.
1634 set_freepage_migratetype(page
, start_migratetype
);
1636 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
1637 start_migratetype
, fallback_mt
);
1646 * Do the hard work of removing an element from the buddy allocator.
1647 * Call me with the zone->lock already held.
1649 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
1655 page
= __rmqueue_smallest(zone
, order
, migratetype
);
1657 if (unlikely(!page
) && migratetype
!= MIGRATE_RESERVE
) {
1658 if (migratetype
== MIGRATE_MOVABLE
)
1659 page
= __rmqueue_cma_fallback(zone
, order
);
1662 page
= __rmqueue_fallback(zone
, order
, migratetype
);
1665 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1666 * is used because __rmqueue_smallest is an inline function
1667 * and we want just one call site
1670 migratetype
= MIGRATE_RESERVE
;
1675 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1680 * Obtain a specified number of elements from the buddy allocator, all under
1681 * a single hold of the lock, for efficiency. Add them to the supplied list.
1682 * Returns the number of new pages which were placed at *list.
1684 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1685 unsigned long count
, struct list_head
*list
,
1686 int migratetype
, bool cold
)
1690 spin_lock(&zone
->lock
);
1691 for (i
= 0; i
< count
; ++i
) {
1692 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
1693 if (unlikely(page
== NULL
))
1697 * Split buddy pages returned by expand() are received here
1698 * in physical page order. The page is added to the callers and
1699 * list and the list head then moves forward. From the callers
1700 * perspective, the linked list is ordered by page number in
1701 * some conditions. This is useful for IO devices that can
1702 * merge IO requests if the physical pages are ordered
1706 list_add(&page
->lru
, list
);
1708 list_add_tail(&page
->lru
, list
);
1710 if (is_migrate_cma(get_freepage_migratetype(page
)))
1711 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
1714 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
1715 spin_unlock(&zone
->lock
);
1721 * Called from the vmstat counter updater to drain pagesets of this
1722 * currently executing processor on remote nodes after they have
1725 * Note that this function must be called with the thread pinned to
1726 * a single processor.
1728 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
1730 unsigned long flags
;
1731 int to_drain
, batch
;
1733 local_irq_save(flags
);
1734 batch
= READ_ONCE(pcp
->batch
);
1735 to_drain
= min(pcp
->count
, batch
);
1737 free_pcppages_bulk(zone
, to_drain
, pcp
);
1738 pcp
->count
-= to_drain
;
1740 local_irq_restore(flags
);
1745 * Drain pcplists of the indicated processor and zone.
1747 * The processor must either be the current processor and the
1748 * thread pinned to the current processor or a processor that
1751 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
1753 unsigned long flags
;
1754 struct per_cpu_pageset
*pset
;
1755 struct per_cpu_pages
*pcp
;
1757 local_irq_save(flags
);
1758 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
1762 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1765 local_irq_restore(flags
);
1769 * Drain pcplists of all zones on the indicated processor.
1771 * The processor must either be the current processor and the
1772 * thread pinned to the current processor or a processor that
1775 static void drain_pages(unsigned int cpu
)
1779 for_each_populated_zone(zone
) {
1780 drain_pages_zone(cpu
, zone
);
1785 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1787 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
1788 * the single zone's pages.
1790 void drain_local_pages(struct zone
*zone
)
1792 int cpu
= smp_processor_id();
1795 drain_pages_zone(cpu
, zone
);
1801 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1803 * When zone parameter is non-NULL, spill just the single zone's pages.
1805 * Note that this code is protected against sending an IPI to an offline
1806 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1807 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1808 * nothing keeps CPUs from showing up after we populated the cpumask and
1809 * before the call to on_each_cpu_mask().
1811 void drain_all_pages(struct zone
*zone
)
1816 * Allocate in the BSS so we wont require allocation in
1817 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1819 static cpumask_t cpus_with_pcps
;
1822 * We don't care about racing with CPU hotplug event
1823 * as offline notification will cause the notified
1824 * cpu to drain that CPU pcps and on_each_cpu_mask
1825 * disables preemption as part of its processing
1827 for_each_online_cpu(cpu
) {
1828 struct per_cpu_pageset
*pcp
;
1830 bool has_pcps
= false;
1833 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
1837 for_each_populated_zone(z
) {
1838 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
1839 if (pcp
->pcp
.count
) {
1847 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
1849 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
1851 on_each_cpu_mask(&cpus_with_pcps
, (smp_call_func_t
) drain_local_pages
,
1855 #ifdef CONFIG_HIBERNATION
1857 void mark_free_pages(struct zone
*zone
)
1859 unsigned long pfn
, max_zone_pfn
;
1860 unsigned long flags
;
1861 unsigned int order
, t
;
1862 struct list_head
*curr
;
1864 if (zone_is_empty(zone
))
1867 spin_lock_irqsave(&zone
->lock
, flags
);
1869 max_zone_pfn
= zone_end_pfn(zone
);
1870 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1871 if (pfn_valid(pfn
)) {
1872 struct page
*page
= pfn_to_page(pfn
);
1874 if (!swsusp_page_is_forbidden(page
))
1875 swsusp_unset_page_free(page
);
1878 for_each_migratetype_order(order
, t
) {
1879 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
1882 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
1883 for (i
= 0; i
< (1UL << order
); i
++)
1884 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
1887 spin_unlock_irqrestore(&zone
->lock
, flags
);
1889 #endif /* CONFIG_PM */
1892 * Free a 0-order page
1893 * cold == true ? free a cold page : free a hot page
1895 void free_hot_cold_page(struct page
*page
, bool cold
)
1897 struct zone
*zone
= page_zone(page
);
1898 struct per_cpu_pages
*pcp
;
1899 unsigned long flags
;
1900 unsigned long pfn
= page_to_pfn(page
);
1903 if (!free_pages_prepare(page
, 0))
1906 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1907 set_freepage_migratetype(page
, migratetype
);
1908 local_irq_save(flags
);
1909 __count_vm_event(PGFREE
);
1912 * We only track unmovable, reclaimable and movable on pcp lists.
1913 * Free ISOLATE pages back to the allocator because they are being
1914 * offlined but treat RESERVE as movable pages so we can get those
1915 * areas back if necessary. Otherwise, we may have to free
1916 * excessively into the page allocator
1918 if (migratetype
>= MIGRATE_PCPTYPES
) {
1919 if (unlikely(is_migrate_isolate(migratetype
))) {
1920 free_one_page(zone
, page
, pfn
, 0, migratetype
);
1923 migratetype
= MIGRATE_MOVABLE
;
1926 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1928 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
1930 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
1932 if (pcp
->count
>= pcp
->high
) {
1933 unsigned long batch
= READ_ONCE(pcp
->batch
);
1934 free_pcppages_bulk(zone
, batch
, pcp
);
1935 pcp
->count
-= batch
;
1939 local_irq_restore(flags
);
1943 * Free a list of 0-order pages
1945 void free_hot_cold_page_list(struct list_head
*list
, bool cold
)
1947 struct page
*page
, *next
;
1949 list_for_each_entry_safe(page
, next
, list
, lru
) {
1950 trace_mm_page_free_batched(page
, cold
);
1951 free_hot_cold_page(page
, cold
);
1956 * split_page takes a non-compound higher-order page, and splits it into
1957 * n (1<<order) sub-pages: page[0..n]
1958 * Each sub-page must be freed individually.
1960 * Note: this is probably too low level an operation for use in drivers.
1961 * Please consult with lkml before using this in your driver.
1963 void split_page(struct page
*page
, unsigned int order
)
1968 VM_BUG_ON_PAGE(PageCompound(page
), page
);
1969 VM_BUG_ON_PAGE(!page_count(page
), page
);
1971 #ifdef CONFIG_KMEMCHECK
1973 * Split shadow pages too, because free(page[0]) would
1974 * otherwise free the whole shadow.
1976 if (kmemcheck_page_is_tracked(page
))
1977 split_page(virt_to_page(page
[0].shadow
), order
);
1980 gfp_mask
= get_page_owner_gfp(page
);
1981 set_page_owner(page
, 0, gfp_mask
);
1982 for (i
= 1; i
< (1 << order
); i
++) {
1983 set_page_refcounted(page
+ i
);
1984 set_page_owner(page
+ i
, 0, gfp_mask
);
1987 EXPORT_SYMBOL_GPL(split_page
);
1989 int __isolate_free_page(struct page
*page
, unsigned int order
)
1991 unsigned long watermark
;
1995 BUG_ON(!PageBuddy(page
));
1997 zone
= page_zone(page
);
1998 mt
= get_pageblock_migratetype(page
);
2000 if (!is_migrate_isolate(mt
)) {
2001 /* Obey watermarks as if the page was being allocated */
2002 watermark
= low_wmark_pages(zone
) + (1 << order
);
2003 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
2006 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
2009 /* Remove page from free list */
2010 list_del(&page
->lru
);
2011 zone
->free_area
[order
].nr_free
--;
2012 rmv_page_order(page
);
2014 set_page_owner(page
, order
, __GFP_MOVABLE
);
2016 /* Set the pageblock if the isolated page is at least a pageblock */
2017 if (order
>= pageblock_order
- 1) {
2018 struct page
*endpage
= page
+ (1 << order
) - 1;
2019 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
2020 int mt
= get_pageblock_migratetype(page
);
2021 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
))
2022 set_pageblock_migratetype(page
,
2028 return 1UL << order
;
2032 * Similar to split_page except the page is already free. As this is only
2033 * being used for migration, the migratetype of the block also changes.
2034 * As this is called with interrupts disabled, the caller is responsible
2035 * for calling arch_alloc_page() and kernel_map_page() after interrupts
2038 * Note: this is probably too low level an operation for use in drivers.
2039 * Please consult with lkml before using this in your driver.
2041 int split_free_page(struct page
*page
)
2046 order
= page_order(page
);
2048 nr_pages
= __isolate_free_page(page
, order
);
2052 /* Split into individual pages */
2053 set_page_refcounted(page
);
2054 split_page(page
, order
);
2059 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2062 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
2063 struct zone
*zone
, unsigned int order
,
2064 gfp_t gfp_flags
, int migratetype
)
2066 unsigned long flags
;
2068 bool cold
= ((gfp_flags
& __GFP_COLD
) != 0);
2070 if (likely(order
== 0)) {
2071 struct per_cpu_pages
*pcp
;
2072 struct list_head
*list
;
2074 local_irq_save(flags
);
2075 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2076 list
= &pcp
->lists
[migratetype
];
2077 if (list_empty(list
)) {
2078 pcp
->count
+= rmqueue_bulk(zone
, 0,
2081 if (unlikely(list_empty(list
)))
2086 page
= list_entry(list
->prev
, struct page
, lru
);
2088 page
= list_entry(list
->next
, struct page
, lru
);
2090 list_del(&page
->lru
);
2093 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
2095 * __GFP_NOFAIL is not to be used in new code.
2097 * All __GFP_NOFAIL callers should be fixed so that they
2098 * properly detect and handle allocation failures.
2100 * We most definitely don't want callers attempting to
2101 * allocate greater than order-1 page units with
2104 WARN_ON_ONCE(order
> 1);
2106 spin_lock_irqsave(&zone
->lock
, flags
);
2107 page
= __rmqueue(zone
, order
, migratetype
);
2108 spin_unlock(&zone
->lock
);
2111 __mod_zone_freepage_state(zone
, -(1 << order
),
2112 get_freepage_migratetype(page
));
2115 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
, -(1 << order
));
2116 if (atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]) <= 0 &&
2117 !test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
))
2118 set_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2120 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
2121 zone_statistics(preferred_zone
, zone
, gfp_flags
);
2122 local_irq_restore(flags
);
2124 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
2128 local_irq_restore(flags
);
2132 #ifdef CONFIG_FAIL_PAGE_ALLOC
2135 struct fault_attr attr
;
2137 u32 ignore_gfp_highmem
;
2138 u32 ignore_gfp_wait
;
2140 } fail_page_alloc
= {
2141 .attr
= FAULT_ATTR_INITIALIZER
,
2142 .ignore_gfp_wait
= 1,
2143 .ignore_gfp_highmem
= 1,
2147 static int __init
setup_fail_page_alloc(char *str
)
2149 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
2151 __setup("fail_page_alloc=", setup_fail_page_alloc
);
2153 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2155 if (order
< fail_page_alloc
.min_order
)
2157 if (gfp_mask
& __GFP_NOFAIL
)
2159 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
2161 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
2164 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
2167 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2169 static int __init
fail_page_alloc_debugfs(void)
2171 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
2174 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
2175 &fail_page_alloc
.attr
);
2177 return PTR_ERR(dir
);
2179 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
2180 &fail_page_alloc
.ignore_gfp_wait
))
2182 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
2183 &fail_page_alloc
.ignore_gfp_highmem
))
2185 if (!debugfs_create_u32("min-order", mode
, dir
,
2186 &fail_page_alloc
.min_order
))
2191 debugfs_remove_recursive(dir
);
2196 late_initcall(fail_page_alloc_debugfs
);
2198 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2200 #else /* CONFIG_FAIL_PAGE_ALLOC */
2202 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2207 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2210 * Return true if free pages are above 'mark'. This takes into account the order
2211 * of the allocation.
2213 static bool __zone_watermark_ok(struct zone
*z
, unsigned int order
,
2214 unsigned long mark
, int classzone_idx
, int alloc_flags
,
2217 /* free_pages may go negative - that's OK */
2222 free_pages
-= (1 << order
) - 1;
2223 if (alloc_flags
& ALLOC_HIGH
)
2225 if (alloc_flags
& ALLOC_HARDER
)
2228 /* If allocation can't use CMA areas don't use free CMA pages */
2229 if (!(alloc_flags
& ALLOC_CMA
))
2230 free_cma
= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2233 if (free_pages
- free_cma
<= min
+ z
->lowmem_reserve
[classzone_idx
])
2235 for (o
= 0; o
< order
; o
++) {
2236 /* At the next order, this order's pages become unavailable */
2237 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
2239 /* Require fewer higher order pages to be free */
2242 if (free_pages
<= min
)
2248 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2249 int classzone_idx
, int alloc_flags
)
2251 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
2252 zone_page_state(z
, NR_FREE_PAGES
));
2255 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
2256 unsigned long mark
, int classzone_idx
, int alloc_flags
)
2258 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
2260 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
2261 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
2263 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
2269 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
2270 * skip over zones that are not allowed by the cpuset, or that have
2271 * been recently (in last second) found to be nearly full. See further
2272 * comments in mmzone.h. Reduces cache footprint of zonelist scans
2273 * that have to skip over a lot of full or unallowed zones.
2275 * If the zonelist cache is present in the passed zonelist, then
2276 * returns a pointer to the allowed node mask (either the current
2277 * tasks mems_allowed, or node_states[N_MEMORY].)
2279 * If the zonelist cache is not available for this zonelist, does
2280 * nothing and returns NULL.
2282 * If the fullzones BITMAP in the zonelist cache is stale (more than
2283 * a second since last zap'd) then we zap it out (clear its bits.)
2285 * We hold off even calling zlc_setup, until after we've checked the
2286 * first zone in the zonelist, on the theory that most allocations will
2287 * be satisfied from that first zone, so best to examine that zone as
2288 * quickly as we can.
2290 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
2292 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
2293 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
2295 zlc
= zonelist
->zlcache_ptr
;
2299 if (time_after(jiffies
, zlc
->last_full_zap
+ HZ
)) {
2300 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
2301 zlc
->last_full_zap
= jiffies
;
2304 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
2305 &cpuset_current_mems_allowed
:
2306 &node_states
[N_MEMORY
];
2307 return allowednodes
;
2311 * Given 'z' scanning a zonelist, run a couple of quick checks to see
2312 * if it is worth looking at further for free memory:
2313 * 1) Check that the zone isn't thought to be full (doesn't have its
2314 * bit set in the zonelist_cache fullzones BITMAP).
2315 * 2) Check that the zones node (obtained from the zonelist_cache
2316 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
2317 * Return true (non-zero) if zone is worth looking at further, or
2318 * else return false (zero) if it is not.
2320 * This check -ignores- the distinction between various watermarks,
2321 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
2322 * found to be full for any variation of these watermarks, it will
2323 * be considered full for up to one second by all requests, unless
2324 * we are so low on memory on all allowed nodes that we are forced
2325 * into the second scan of the zonelist.
2327 * In the second scan we ignore this zonelist cache and exactly
2328 * apply the watermarks to all zones, even it is slower to do so.
2329 * We are low on memory in the second scan, and should leave no stone
2330 * unturned looking for a free page.
2332 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
2333 nodemask_t
*allowednodes
)
2335 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
2336 int i
; /* index of *z in zonelist zones */
2337 int n
; /* node that zone *z is on */
2339 zlc
= zonelist
->zlcache_ptr
;
2343 i
= z
- zonelist
->_zonerefs
;
2346 /* This zone is worth trying if it is allowed but not full */
2347 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
2351 * Given 'z' scanning a zonelist, set the corresponding bit in
2352 * zlc->fullzones, so that subsequent attempts to allocate a page
2353 * from that zone don't waste time re-examining it.
2355 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
2357 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
2358 int i
; /* index of *z in zonelist zones */
2360 zlc
= zonelist
->zlcache_ptr
;
2364 i
= z
- zonelist
->_zonerefs
;
2366 set_bit(i
, zlc
->fullzones
);
2370 * clear all zones full, called after direct reclaim makes progress so that
2371 * a zone that was recently full is not skipped over for up to a second
2373 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
2375 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
2377 zlc
= zonelist
->zlcache_ptr
;
2381 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
2384 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2386 return local_zone
->node
== zone
->node
;
2389 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2391 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <
2395 #else /* CONFIG_NUMA */
2397 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
2402 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
2403 nodemask_t
*allowednodes
)
2408 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
2412 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
2416 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2421 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2426 #endif /* CONFIG_NUMA */
2428 static void reset_alloc_batches(struct zone
*preferred_zone
)
2430 struct zone
*zone
= preferred_zone
->zone_pgdat
->node_zones
;
2433 mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
2434 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
2435 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
2436 clear_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2437 } while (zone
++ != preferred_zone
);
2441 * get_page_from_freelist goes through the zonelist trying to allocate
2444 static struct page
*
2445 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
2446 const struct alloc_context
*ac
)
2448 struct zonelist
*zonelist
= ac
->zonelist
;
2450 struct page
*page
= NULL
;
2452 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
2453 int zlc_active
= 0; /* set if using zonelist_cache */
2454 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
2455 bool consider_zone_dirty
= (alloc_flags
& ALLOC_WMARK_LOW
) &&
2456 (gfp_mask
& __GFP_WRITE
);
2457 int nr_fair_skipped
= 0;
2458 bool zonelist_rescan
;
2461 zonelist_rescan
= false;
2464 * Scan zonelist, looking for a zone with enough free.
2465 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2467 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
2471 if (IS_ENABLED(CONFIG_NUMA
) && zlc_active
&&
2472 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
2474 if (cpusets_enabled() &&
2475 (alloc_flags
& ALLOC_CPUSET
) &&
2476 !cpuset_zone_allowed(zone
, gfp_mask
))
2479 * Distribute pages in proportion to the individual
2480 * zone size to ensure fair page aging. The zone a
2481 * page was allocated in should have no effect on the
2482 * time the page has in memory before being reclaimed.
2484 if (alloc_flags
& ALLOC_FAIR
) {
2485 if (!zone_local(ac
->preferred_zone
, zone
))
2487 if (test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
)) {
2493 * When allocating a page cache page for writing, we
2494 * want to get it from a zone that is within its dirty
2495 * limit, such that no single zone holds more than its
2496 * proportional share of globally allowed dirty pages.
2497 * The dirty limits take into account the zone's
2498 * lowmem reserves and high watermark so that kswapd
2499 * should be able to balance it without having to
2500 * write pages from its LRU list.
2502 * This may look like it could increase pressure on
2503 * lower zones by failing allocations in higher zones
2504 * before they are full. But the pages that do spill
2505 * over are limited as the lower zones are protected
2506 * by this very same mechanism. It should not become
2507 * a practical burden to them.
2509 * XXX: For now, allow allocations to potentially
2510 * exceed the per-zone dirty limit in the slowpath
2511 * (ALLOC_WMARK_LOW unset) before going into reclaim,
2512 * which is important when on a NUMA setup the allowed
2513 * zones are together not big enough to reach the
2514 * global limit. The proper fix for these situations
2515 * will require awareness of zones in the
2516 * dirty-throttling and the flusher threads.
2518 if (consider_zone_dirty
&& !zone_dirty_ok(zone
))
2521 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
2522 if (!zone_watermark_ok(zone
, order
, mark
,
2523 ac
->classzone_idx
, alloc_flags
)) {
2526 /* Checked here to keep the fast path fast */
2527 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
2528 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
2531 if (IS_ENABLED(CONFIG_NUMA
) &&
2532 !did_zlc_setup
&& nr_online_nodes
> 1) {
2534 * we do zlc_setup if there are multiple nodes
2535 * and before considering the first zone allowed
2538 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
2543 if (zone_reclaim_mode
== 0 ||
2544 !zone_allows_reclaim(ac
->preferred_zone
, zone
))
2545 goto this_zone_full
;
2548 * As we may have just activated ZLC, check if the first
2549 * eligible zone has failed zone_reclaim recently.
2551 if (IS_ENABLED(CONFIG_NUMA
) && zlc_active
&&
2552 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
2555 ret
= zone_reclaim(zone
, gfp_mask
, order
);
2557 case ZONE_RECLAIM_NOSCAN
:
2560 case ZONE_RECLAIM_FULL
:
2561 /* scanned but unreclaimable */
2564 /* did we reclaim enough */
2565 if (zone_watermark_ok(zone
, order
, mark
,
2566 ac
->classzone_idx
, alloc_flags
))
2570 * Failed to reclaim enough to meet watermark.
2571 * Only mark the zone full if checking the min
2572 * watermark or if we failed to reclaim just
2573 * 1<<order pages or else the page allocator
2574 * fastpath will prematurely mark zones full
2575 * when the watermark is between the low and
2578 if (((alloc_flags
& ALLOC_WMARK_MASK
) == ALLOC_WMARK_MIN
) ||
2579 ret
== ZONE_RECLAIM_SOME
)
2580 goto this_zone_full
;
2587 page
= buffered_rmqueue(ac
->preferred_zone
, zone
, order
,
2588 gfp_mask
, ac
->migratetype
);
2590 if (prep_new_page(page
, order
, gfp_mask
, alloc_flags
))
2595 if (IS_ENABLED(CONFIG_NUMA
) && zlc_active
)
2596 zlc_mark_zone_full(zonelist
, z
);
2600 * The first pass makes sure allocations are spread fairly within the
2601 * local node. However, the local node might have free pages left
2602 * after the fairness batches are exhausted, and remote zones haven't
2603 * even been considered yet. Try once more without fairness, and
2604 * include remote zones now, before entering the slowpath and waking
2605 * kswapd: prefer spilling to a remote zone over swapping locally.
2607 if (alloc_flags
& ALLOC_FAIR
) {
2608 alloc_flags
&= ~ALLOC_FAIR
;
2609 if (nr_fair_skipped
) {
2610 zonelist_rescan
= true;
2611 reset_alloc_batches(ac
->preferred_zone
);
2613 if (nr_online_nodes
> 1)
2614 zonelist_rescan
= true;
2617 if (unlikely(IS_ENABLED(CONFIG_NUMA
) && zlc_active
)) {
2618 /* Disable zlc cache for second zonelist scan */
2620 zonelist_rescan
= true;
2623 if (zonelist_rescan
)
2630 * Large machines with many possible nodes should not always dump per-node
2631 * meminfo in irq context.
2633 static inline bool should_suppress_show_mem(void)
2638 ret
= in_interrupt();
2643 static DEFINE_RATELIMIT_STATE(nopage_rs
,
2644 DEFAULT_RATELIMIT_INTERVAL
,
2645 DEFAULT_RATELIMIT_BURST
);
2647 void warn_alloc_failed(gfp_t gfp_mask
, int order
, const char *fmt
, ...)
2649 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
2651 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
2652 debug_guardpage_minorder() > 0)
2656 * This documents exceptions given to allocations in certain
2657 * contexts that are allowed to allocate outside current's set
2660 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2661 if (test_thread_flag(TIF_MEMDIE
) ||
2662 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
2663 filter
&= ~SHOW_MEM_FILTER_NODES
;
2664 if (in_interrupt() || !(gfp_mask
& __GFP_WAIT
))
2665 filter
&= ~SHOW_MEM_FILTER_NODES
;
2668 struct va_format vaf
;
2671 va_start(args
, fmt
);
2676 pr_warn("%pV", &vaf
);
2681 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
2682 current
->comm
, order
, gfp_mask
);
2685 if (!should_suppress_show_mem())
2689 static inline struct page
*
2690 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
2691 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
2695 *did_some_progress
= 0;
2698 * Acquire the oom lock. If that fails, somebody else is
2699 * making progress for us.
2701 if (!mutex_trylock(&oom_lock
)) {
2702 *did_some_progress
= 1;
2703 schedule_timeout_uninterruptible(1);
2708 * Go through the zonelist yet one more time, keep very high watermark
2709 * here, this is only to catch a parallel oom killing, we must fail if
2710 * we're still under heavy pressure.
2712 page
= get_page_from_freelist(gfp_mask
| __GFP_HARDWALL
, order
,
2713 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
2717 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2718 /* Coredumps can quickly deplete all memory reserves */
2719 if (current
->flags
& PF_DUMPCORE
)
2721 /* The OOM killer will not help higher order allocs */
2722 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2724 /* The OOM killer does not needlessly kill tasks for lowmem */
2725 if (ac
->high_zoneidx
< ZONE_NORMAL
)
2727 /* The OOM killer does not compensate for IO-less reclaim */
2728 if (!(gfp_mask
& __GFP_FS
)) {
2730 * XXX: Page reclaim didn't yield anything,
2731 * and the OOM killer can't be invoked, but
2732 * keep looping as per tradition.
2734 *did_some_progress
= 1;
2737 if (pm_suspended_storage())
2739 /* The OOM killer may not free memory on a specific node */
2740 if (gfp_mask
& __GFP_THISNODE
)
2743 /* Exhausted what can be done so it's blamo time */
2744 if (out_of_memory(ac
->zonelist
, gfp_mask
, order
, ac
->nodemask
, false)
2745 || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
))
2746 *did_some_progress
= 1;
2748 mutex_unlock(&oom_lock
);
2752 #ifdef CONFIG_COMPACTION
2753 /* Try memory compaction for high-order allocations before reclaim */
2754 static struct page
*
2755 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2756 int alloc_flags
, const struct alloc_context
*ac
,
2757 enum migrate_mode mode
, int *contended_compaction
,
2758 bool *deferred_compaction
)
2760 unsigned long compact_result
;
2766 current
->flags
|= PF_MEMALLOC
;
2767 compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
2768 mode
, contended_compaction
);
2769 current
->flags
&= ~PF_MEMALLOC
;
2771 switch (compact_result
) {
2772 case COMPACT_DEFERRED
:
2773 *deferred_compaction
= true;
2775 case COMPACT_SKIPPED
:
2782 * At least in one zone compaction wasn't deferred or skipped, so let's
2783 * count a compaction stall
2785 count_vm_event(COMPACTSTALL
);
2787 page
= get_page_from_freelist(gfp_mask
, order
,
2788 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
2791 struct zone
*zone
= page_zone(page
);
2793 zone
->compact_blockskip_flush
= false;
2794 compaction_defer_reset(zone
, order
, true);
2795 count_vm_event(COMPACTSUCCESS
);
2800 * It's bad if compaction run occurs and fails. The most likely reason
2801 * is that pages exist, but not enough to satisfy watermarks.
2803 count_vm_event(COMPACTFAIL
);
2810 static inline struct page
*
2811 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2812 int alloc_flags
, const struct alloc_context
*ac
,
2813 enum migrate_mode mode
, int *contended_compaction
,
2814 bool *deferred_compaction
)
2818 #endif /* CONFIG_COMPACTION */
2820 /* Perform direct synchronous page reclaim */
2822 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
2823 const struct alloc_context
*ac
)
2825 struct reclaim_state reclaim_state
;
2830 /* We now go into synchronous reclaim */
2831 cpuset_memory_pressure_bump();
2832 current
->flags
|= PF_MEMALLOC
;
2833 lockdep_set_current_reclaim_state(gfp_mask
);
2834 reclaim_state
.reclaimed_slab
= 0;
2835 current
->reclaim_state
= &reclaim_state
;
2837 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
2840 current
->reclaim_state
= NULL
;
2841 lockdep_clear_current_reclaim_state();
2842 current
->flags
&= ~PF_MEMALLOC
;
2849 /* The really slow allocator path where we enter direct reclaim */
2850 static inline struct page
*
2851 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
2852 int alloc_flags
, const struct alloc_context
*ac
,
2853 unsigned long *did_some_progress
)
2855 struct page
*page
= NULL
;
2856 bool drained
= false;
2858 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
2859 if (unlikely(!(*did_some_progress
)))
2862 /* After successful reclaim, reconsider all zones for allocation */
2863 if (IS_ENABLED(CONFIG_NUMA
))
2864 zlc_clear_zones_full(ac
->zonelist
);
2867 page
= get_page_from_freelist(gfp_mask
, order
,
2868 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
2871 * If an allocation failed after direct reclaim, it could be because
2872 * pages are pinned on the per-cpu lists. Drain them and try again
2874 if (!page
&& !drained
) {
2875 drain_all_pages(NULL
);
2884 * This is called in the allocator slow-path if the allocation request is of
2885 * sufficient urgency to ignore watermarks and take other desperate measures
2887 static inline struct page
*
2888 __alloc_pages_high_priority(gfp_t gfp_mask
, unsigned int order
,
2889 const struct alloc_context
*ac
)
2894 page
= get_page_from_freelist(gfp_mask
, order
,
2895 ALLOC_NO_WATERMARKS
, ac
);
2897 if (!page
&& gfp_mask
& __GFP_NOFAIL
)
2898 wait_iff_congested(ac
->preferred_zone
, BLK_RW_ASYNC
,
2900 } while (!page
&& (gfp_mask
& __GFP_NOFAIL
));
2905 static void wake_all_kswapds(unsigned int order
, const struct alloc_context
*ac
)
2910 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
2911 ac
->high_zoneidx
, ac
->nodemask
)
2912 wakeup_kswapd(zone
, order
, zone_idx(ac
->preferred_zone
));
2916 gfp_to_alloc_flags(gfp_t gfp_mask
)
2918 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
2919 const bool atomic
= !(gfp_mask
& (__GFP_WAIT
| __GFP_NO_KSWAPD
));
2921 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2922 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
2925 * The caller may dip into page reserves a bit more if the caller
2926 * cannot run direct reclaim, or if the caller has realtime scheduling
2927 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2928 * set both ALLOC_HARDER (atomic == true) and ALLOC_HIGH (__GFP_HIGH).
2930 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
2934 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
2935 * if it can't schedule.
2937 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2938 alloc_flags
|= ALLOC_HARDER
;
2940 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
2941 * comment for __cpuset_node_allowed().
2943 alloc_flags
&= ~ALLOC_CPUSET
;
2944 } else if (unlikely(rt_task(current
)) && !in_interrupt())
2945 alloc_flags
|= ALLOC_HARDER
;
2947 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
2948 if (gfp_mask
& __GFP_MEMALLOC
)
2949 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2950 else if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
2951 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2952 else if (!in_interrupt() &&
2953 ((current
->flags
& PF_MEMALLOC
) ||
2954 unlikely(test_thread_flag(TIF_MEMDIE
))))
2955 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2958 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
2959 alloc_flags
|= ALLOC_CMA
;
2964 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
2966 return !!(gfp_to_alloc_flags(gfp_mask
) & ALLOC_NO_WATERMARKS
);
2969 static inline struct page
*
2970 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
2971 struct alloc_context
*ac
)
2973 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
2974 struct page
*page
= NULL
;
2976 unsigned long pages_reclaimed
= 0;
2977 unsigned long did_some_progress
;
2978 enum migrate_mode migration_mode
= MIGRATE_ASYNC
;
2979 bool deferred_compaction
= false;
2980 int contended_compaction
= COMPACT_CONTENDED_NONE
;
2983 * In the slowpath, we sanity check order to avoid ever trying to
2984 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
2985 * be using allocators in order of preference for an area that is
2988 if (order
>= MAX_ORDER
) {
2989 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
2994 * If this allocation cannot block and it is for a specific node, then
2995 * fail early. There's no need to wakeup kswapd or retry for a
2996 * speculative node-specific allocation.
2998 if (IS_ENABLED(CONFIG_NUMA
) && (gfp_mask
& __GFP_THISNODE
) && !wait
)
3002 if (!(gfp_mask
& __GFP_NO_KSWAPD
))
3003 wake_all_kswapds(order
, ac
);
3006 * OK, we're below the kswapd watermark and have kicked background
3007 * reclaim. Now things get more complex, so set up alloc_flags according
3008 * to how we want to proceed.
3010 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
3013 * Find the true preferred zone if the allocation is unconstrained by
3016 if (!(alloc_flags
& ALLOC_CPUSET
) && !ac
->nodemask
) {
3017 struct zoneref
*preferred_zoneref
;
3018 preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3019 ac
->high_zoneidx
, NULL
, &ac
->preferred_zone
);
3020 ac
->classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
3023 /* This is the last chance, in general, before the goto nopage. */
3024 page
= get_page_from_freelist(gfp_mask
, order
,
3025 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3029 /* Allocate without watermarks if the context allows */
3030 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
3032 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
3033 * the allocation is high priority and these type of
3034 * allocations are system rather than user orientated
3036 ac
->zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
3038 page
= __alloc_pages_high_priority(gfp_mask
, order
, ac
);
3045 /* Atomic allocations - we can't balance anything */
3048 * All existing users of the deprecated __GFP_NOFAIL are
3049 * blockable, so warn of any new users that actually allow this
3050 * type of allocation to fail.
3052 WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
);
3056 /* Avoid recursion of direct reclaim */
3057 if (current
->flags
& PF_MEMALLOC
)
3060 /* Avoid allocations with no watermarks from looping endlessly */
3061 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
3065 * Try direct compaction. The first pass is asynchronous. Subsequent
3066 * attempts after direct reclaim are synchronous
3068 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
3070 &contended_compaction
,
3071 &deferred_compaction
);
3075 /* Checks for THP-specific high-order allocations */
3076 if ((gfp_mask
& GFP_TRANSHUGE
) == GFP_TRANSHUGE
) {
3078 * If compaction is deferred for high-order allocations, it is
3079 * because sync compaction recently failed. If this is the case
3080 * and the caller requested a THP allocation, we do not want
3081 * to heavily disrupt the system, so we fail the allocation
3082 * instead of entering direct reclaim.
3084 if (deferred_compaction
)
3088 * In all zones where compaction was attempted (and not
3089 * deferred or skipped), lock contention has been detected.
3090 * For THP allocation we do not want to disrupt the others
3091 * so we fallback to base pages instead.
3093 if (contended_compaction
== COMPACT_CONTENDED_LOCK
)
3097 * If compaction was aborted due to need_resched(), we do not
3098 * want to further increase allocation latency, unless it is
3099 * khugepaged trying to collapse.
3101 if (contended_compaction
== COMPACT_CONTENDED_SCHED
3102 && !(current
->flags
& PF_KTHREAD
))
3107 * It can become very expensive to allocate transparent hugepages at
3108 * fault, so use asynchronous memory compaction for THP unless it is
3109 * khugepaged trying to collapse.
3111 if ((gfp_mask
& GFP_TRANSHUGE
) != GFP_TRANSHUGE
||
3112 (current
->flags
& PF_KTHREAD
))
3113 migration_mode
= MIGRATE_SYNC_LIGHT
;
3115 /* Try direct reclaim and then allocating */
3116 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
3117 &did_some_progress
);
3121 /* Do not loop if specifically requested */
3122 if (gfp_mask
& __GFP_NORETRY
)
3125 /* Keep reclaiming pages as long as there is reasonable progress */
3126 pages_reclaimed
+= did_some_progress
;
3127 if ((did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
) ||
3128 ((gfp_mask
& __GFP_REPEAT
) && pages_reclaimed
< (1 << order
))) {
3129 /* Wait for some write requests to complete then retry */
3130 wait_iff_congested(ac
->preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
3134 /* Reclaim has failed us, start killing things */
3135 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
3139 /* Retry as long as the OOM killer is making progress */
3140 if (did_some_progress
)
3145 * High-order allocations do not necessarily loop after
3146 * direct reclaim and reclaim/compaction depends on compaction
3147 * being called after reclaim so call directly if necessary
3149 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
,
3151 &contended_compaction
,
3152 &deferred_compaction
);
3156 warn_alloc_failed(gfp_mask
, order
, NULL
);
3162 * This is the 'heart' of the zoned buddy allocator.
3165 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
3166 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
3168 struct zoneref
*preferred_zoneref
;
3169 struct page
*page
= NULL
;
3170 unsigned int cpuset_mems_cookie
;
3171 int alloc_flags
= ALLOC_WMARK_LOW
|ALLOC_CPUSET
|ALLOC_FAIR
;
3172 gfp_t alloc_mask
; /* The gfp_t that was actually used for allocation */
3173 struct alloc_context ac
= {
3174 .high_zoneidx
= gfp_zone(gfp_mask
),
3175 .nodemask
= nodemask
,
3176 .migratetype
= gfpflags_to_migratetype(gfp_mask
),
3179 gfp_mask
&= gfp_allowed_mask
;
3181 lockdep_trace_alloc(gfp_mask
);
3183 might_sleep_if(gfp_mask
& __GFP_WAIT
);
3185 if (should_fail_alloc_page(gfp_mask
, order
))
3189 * Check the zones suitable for the gfp_mask contain at least one
3190 * valid zone. It's possible to have an empty zonelist as a result
3191 * of __GFP_THISNODE and a memoryless node
3193 if (unlikely(!zonelist
->_zonerefs
->zone
))
3196 if (IS_ENABLED(CONFIG_CMA
) && ac
.migratetype
== MIGRATE_MOVABLE
)
3197 alloc_flags
|= ALLOC_CMA
;
3200 cpuset_mems_cookie
= read_mems_allowed_begin();
3202 /* We set it here, as __alloc_pages_slowpath might have changed it */
3203 ac
.zonelist
= zonelist
;
3204 /* The preferred zone is used for statistics later */
3205 preferred_zoneref
= first_zones_zonelist(ac
.zonelist
, ac
.high_zoneidx
,
3206 ac
.nodemask
? : &cpuset_current_mems_allowed
,
3207 &ac
.preferred_zone
);
3208 if (!ac
.preferred_zone
)
3210 ac
.classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
3212 /* First allocation attempt */
3213 alloc_mask
= gfp_mask
|__GFP_HARDWALL
;
3214 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
3215 if (unlikely(!page
)) {
3217 * Runtime PM, block IO and its error handling path
3218 * can deadlock because I/O on the device might not
3221 alloc_mask
= memalloc_noio_flags(gfp_mask
);
3223 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
3226 if (kmemcheck_enabled
&& page
)
3227 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
3229 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
3233 * When updating a task's mems_allowed, it is possible to race with
3234 * parallel threads in such a way that an allocation can fail while
3235 * the mask is being updated. If a page allocation is about to fail,
3236 * check if the cpuset changed during allocation and if so, retry.
3238 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
)))
3243 EXPORT_SYMBOL(__alloc_pages_nodemask
);
3246 * Common helper functions.
3248 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
3253 * __get_free_pages() returns a 32-bit address, which cannot represent
3256 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
3258 page
= alloc_pages(gfp_mask
, order
);
3261 return (unsigned long) page_address(page
);
3263 EXPORT_SYMBOL(__get_free_pages
);
3265 unsigned long get_zeroed_page(gfp_t gfp_mask
)
3267 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
3269 EXPORT_SYMBOL(get_zeroed_page
);
3271 void __free_pages(struct page
*page
, unsigned int order
)
3273 if (put_page_testzero(page
)) {
3275 free_hot_cold_page(page
, false);
3277 __free_pages_ok(page
, order
);
3281 EXPORT_SYMBOL(__free_pages
);
3283 void free_pages(unsigned long addr
, unsigned int order
)
3286 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3287 __free_pages(virt_to_page((void *)addr
), order
);
3291 EXPORT_SYMBOL(free_pages
);
3295 * An arbitrary-length arbitrary-offset area of memory which resides
3296 * within a 0 or higher order page. Multiple fragments within that page
3297 * are individually refcounted, in the page's reference counter.
3299 * The page_frag functions below provide a simple allocation framework for
3300 * page fragments. This is used by the network stack and network device
3301 * drivers to provide a backing region of memory for use as either an
3302 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3304 static struct page
*__page_frag_refill(struct page_frag_cache
*nc
,
3307 struct page
*page
= NULL
;
3308 gfp_t gfp
= gfp_mask
;
3310 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3311 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
3313 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
3314 PAGE_FRAG_CACHE_MAX_ORDER
);
3315 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
3317 if (unlikely(!page
))
3318 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
3320 nc
->va
= page
? page_address(page
) : NULL
;
3325 void *__alloc_page_frag(struct page_frag_cache
*nc
,
3326 unsigned int fragsz
, gfp_t gfp_mask
)
3328 unsigned int size
= PAGE_SIZE
;
3332 if (unlikely(!nc
->va
)) {
3334 page
= __page_frag_refill(nc
, gfp_mask
);
3338 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3339 /* if size can vary use size else just use PAGE_SIZE */
3342 /* Even if we own the page, we do not use atomic_set().
3343 * This would break get_page_unless_zero() users.
3345 atomic_add(size
- 1, &page
->_count
);
3347 /* reset page count bias and offset to start of new frag */
3348 nc
->pfmemalloc
= page
->pfmemalloc
;
3349 nc
->pagecnt_bias
= size
;
3353 offset
= nc
->offset
- fragsz
;
3354 if (unlikely(offset
< 0)) {
3355 page
= virt_to_page(nc
->va
);
3357 if (!atomic_sub_and_test(nc
->pagecnt_bias
, &page
->_count
))
3360 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3361 /* if size can vary use size else just use PAGE_SIZE */
3364 /* OK, page count is 0, we can safely set it */
3365 atomic_set(&page
->_count
, size
);
3367 /* reset page count bias and offset to start of new frag */
3368 nc
->pagecnt_bias
= size
;
3369 offset
= size
- fragsz
;
3373 nc
->offset
= offset
;
3375 return nc
->va
+ offset
;
3377 EXPORT_SYMBOL(__alloc_page_frag
);
3380 * Frees a page fragment allocated out of either a compound or order 0 page.
3382 void __free_page_frag(void *addr
)
3384 struct page
*page
= virt_to_head_page(addr
);
3386 if (unlikely(put_page_testzero(page
)))
3387 __free_pages_ok(page
, compound_order(page
));
3389 EXPORT_SYMBOL(__free_page_frag
);
3392 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
3393 * of the current memory cgroup.
3395 * It should be used when the caller would like to use kmalloc, but since the
3396 * allocation is large, it has to fall back to the page allocator.
3398 struct page
*alloc_kmem_pages(gfp_t gfp_mask
, unsigned int order
)
3401 struct mem_cgroup
*memcg
= NULL
;
3403 if (!memcg_kmem_newpage_charge(gfp_mask
, &memcg
, order
))
3405 page
= alloc_pages(gfp_mask
, order
);
3406 memcg_kmem_commit_charge(page
, memcg
, order
);
3410 struct page
*alloc_kmem_pages_node(int nid
, gfp_t gfp_mask
, unsigned int order
)
3413 struct mem_cgroup
*memcg
= NULL
;
3415 if (!memcg_kmem_newpage_charge(gfp_mask
, &memcg
, order
))
3417 page
= alloc_pages_node(nid
, gfp_mask
, order
);
3418 memcg_kmem_commit_charge(page
, memcg
, order
);
3423 * __free_kmem_pages and free_kmem_pages will free pages allocated with
3426 void __free_kmem_pages(struct page
*page
, unsigned int order
)
3428 memcg_kmem_uncharge_pages(page
, order
);
3429 __free_pages(page
, order
);
3432 void free_kmem_pages(unsigned long addr
, unsigned int order
)
3435 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3436 __free_kmem_pages(virt_to_page((void *)addr
), order
);
3440 static void *make_alloc_exact(unsigned long addr
, unsigned order
, size_t size
)
3443 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
3444 unsigned long used
= addr
+ PAGE_ALIGN(size
);
3446 split_page(virt_to_page((void *)addr
), order
);
3447 while (used
< alloc_end
) {
3452 return (void *)addr
;
3456 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
3457 * @size: the number of bytes to allocate
3458 * @gfp_mask: GFP flags for the allocation
3460 * This function is similar to alloc_pages(), except that it allocates the
3461 * minimum number of pages to satisfy the request. alloc_pages() can only
3462 * allocate memory in power-of-two pages.
3464 * This function is also limited by MAX_ORDER.
3466 * Memory allocated by this function must be released by free_pages_exact().
3468 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
3470 unsigned int order
= get_order(size
);
3473 addr
= __get_free_pages(gfp_mask
, order
);
3474 return make_alloc_exact(addr
, order
, size
);
3476 EXPORT_SYMBOL(alloc_pages_exact
);
3479 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3481 * @nid: the preferred node ID where memory should be allocated
3482 * @size: the number of bytes to allocate
3483 * @gfp_mask: GFP flags for the allocation
3485 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3487 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
3490 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
3492 unsigned order
= get_order(size
);
3493 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
3496 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
3500 * free_pages_exact - release memory allocated via alloc_pages_exact()
3501 * @virt: the value returned by alloc_pages_exact.
3502 * @size: size of allocation, same value as passed to alloc_pages_exact().
3504 * Release the memory allocated by a previous call to alloc_pages_exact.
3506 void free_pages_exact(void *virt
, size_t size
)
3508 unsigned long addr
= (unsigned long)virt
;
3509 unsigned long end
= addr
+ PAGE_ALIGN(size
);
3511 while (addr
< end
) {
3516 EXPORT_SYMBOL(free_pages_exact
);
3519 * nr_free_zone_pages - count number of pages beyond high watermark
3520 * @offset: The zone index of the highest zone
3522 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3523 * high watermark within all zones at or below a given zone index. For each
3524 * zone, the number of pages is calculated as:
3525 * managed_pages - high_pages
3527 static unsigned long nr_free_zone_pages(int offset
)
3532 /* Just pick one node, since fallback list is circular */
3533 unsigned long sum
= 0;
3535 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
3537 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
3538 unsigned long size
= zone
->managed_pages
;
3539 unsigned long high
= high_wmark_pages(zone
);
3548 * nr_free_buffer_pages - count number of pages beyond high watermark
3550 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3551 * watermark within ZONE_DMA and ZONE_NORMAL.
3553 unsigned long nr_free_buffer_pages(void)
3555 return nr_free_zone_pages(gfp_zone(GFP_USER
));
3557 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
3560 * nr_free_pagecache_pages - count number of pages beyond high watermark
3562 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3563 * high watermark within all zones.
3565 unsigned long nr_free_pagecache_pages(void)
3567 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
3570 static inline void show_node(struct zone
*zone
)
3572 if (IS_ENABLED(CONFIG_NUMA
))
3573 printk("Node %d ", zone_to_nid(zone
));
3576 void si_meminfo(struct sysinfo
*val
)
3578 val
->totalram
= totalram_pages
;
3579 val
->sharedram
= global_page_state(NR_SHMEM
);
3580 val
->freeram
= global_page_state(NR_FREE_PAGES
);
3581 val
->bufferram
= nr_blockdev_pages();
3582 val
->totalhigh
= totalhigh_pages
;
3583 val
->freehigh
= nr_free_highpages();
3584 val
->mem_unit
= PAGE_SIZE
;
3587 EXPORT_SYMBOL(si_meminfo
);
3590 void si_meminfo_node(struct sysinfo
*val
, int nid
)
3592 int zone_type
; /* needs to be signed */
3593 unsigned long managed_pages
= 0;
3594 pg_data_t
*pgdat
= NODE_DATA(nid
);
3596 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
3597 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
3598 val
->totalram
= managed_pages
;
3599 val
->sharedram
= node_page_state(nid
, NR_SHMEM
);
3600 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
3601 #ifdef CONFIG_HIGHMEM
3602 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].managed_pages
;
3603 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
3609 val
->mem_unit
= PAGE_SIZE
;
3614 * Determine whether the node should be displayed or not, depending on whether
3615 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3617 bool skip_free_areas_node(unsigned int flags
, int nid
)
3620 unsigned int cpuset_mems_cookie
;
3622 if (!(flags
& SHOW_MEM_FILTER_NODES
))
3626 cpuset_mems_cookie
= read_mems_allowed_begin();
3627 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
3628 } while (read_mems_allowed_retry(cpuset_mems_cookie
));
3633 #define K(x) ((x) << (PAGE_SHIFT-10))
3635 static void show_migration_types(unsigned char type
)
3637 static const char types
[MIGRATE_TYPES
] = {
3638 [MIGRATE_UNMOVABLE
] = 'U',
3639 [MIGRATE_RECLAIMABLE
] = 'E',
3640 [MIGRATE_MOVABLE
] = 'M',
3641 [MIGRATE_RESERVE
] = 'R',
3643 [MIGRATE_CMA
] = 'C',
3645 #ifdef CONFIG_MEMORY_ISOLATION
3646 [MIGRATE_ISOLATE
] = 'I',
3649 char tmp
[MIGRATE_TYPES
+ 1];
3653 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
3654 if (type
& (1 << i
))
3659 printk("(%s) ", tmp
);
3663 * Show free area list (used inside shift_scroll-lock stuff)
3664 * We also calculate the percentage fragmentation. We do this by counting the
3665 * memory on each free list with the exception of the first item on the list.
3668 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
3671 void show_free_areas(unsigned int filter
)
3673 unsigned long free_pcp
= 0;
3677 for_each_populated_zone(zone
) {
3678 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3681 for_each_online_cpu(cpu
)
3682 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
3685 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3686 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3687 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
3688 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3689 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3690 " free:%lu free_pcp:%lu free_cma:%lu\n",
3691 global_page_state(NR_ACTIVE_ANON
),
3692 global_page_state(NR_INACTIVE_ANON
),
3693 global_page_state(NR_ISOLATED_ANON
),
3694 global_page_state(NR_ACTIVE_FILE
),
3695 global_page_state(NR_INACTIVE_FILE
),
3696 global_page_state(NR_ISOLATED_FILE
),
3697 global_page_state(NR_UNEVICTABLE
),
3698 global_page_state(NR_FILE_DIRTY
),
3699 global_page_state(NR_WRITEBACK
),
3700 global_page_state(NR_UNSTABLE_NFS
),
3701 global_page_state(NR_SLAB_RECLAIMABLE
),
3702 global_page_state(NR_SLAB_UNRECLAIMABLE
),
3703 global_page_state(NR_FILE_MAPPED
),
3704 global_page_state(NR_SHMEM
),
3705 global_page_state(NR_PAGETABLE
),
3706 global_page_state(NR_BOUNCE
),
3707 global_page_state(NR_FREE_PAGES
),
3709 global_page_state(NR_FREE_CMA_PAGES
));
3711 for_each_populated_zone(zone
) {
3714 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3718 for_each_online_cpu(cpu
)
3719 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
3727 " active_anon:%lukB"
3728 " inactive_anon:%lukB"
3729 " active_file:%lukB"
3730 " inactive_file:%lukB"
3731 " unevictable:%lukB"
3732 " isolated(anon):%lukB"
3733 " isolated(file):%lukB"
3741 " slab_reclaimable:%lukB"
3742 " slab_unreclaimable:%lukB"
3743 " kernel_stack:%lukB"
3750 " writeback_tmp:%lukB"
3751 " pages_scanned:%lu"
3752 " all_unreclaimable? %s"
3755 K(zone_page_state(zone
, NR_FREE_PAGES
)),
3756 K(min_wmark_pages(zone
)),
3757 K(low_wmark_pages(zone
)),
3758 K(high_wmark_pages(zone
)),
3759 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
3760 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
3761 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
3762 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
3763 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
3764 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
3765 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
3766 K(zone
->present_pages
),
3767 K(zone
->managed_pages
),
3768 K(zone_page_state(zone
, NR_MLOCK
)),
3769 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
3770 K(zone_page_state(zone
, NR_WRITEBACK
)),
3771 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
3772 K(zone_page_state(zone
, NR_SHMEM
)),
3773 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
3774 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
3775 zone_page_state(zone
, NR_KERNEL_STACK
) *
3777 K(zone_page_state(zone
, NR_PAGETABLE
)),
3778 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
3779 K(zone_page_state(zone
, NR_BOUNCE
)),
3781 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
3782 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)),
3783 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
3784 K(zone_page_state(zone
, NR_PAGES_SCANNED
)),
3785 (!zone_reclaimable(zone
) ? "yes" : "no")
3787 printk("lowmem_reserve[]:");
3788 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3789 printk(" %ld", zone
->lowmem_reserve
[i
]);
3793 for_each_populated_zone(zone
) {
3794 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
3795 unsigned char types
[MAX_ORDER
];
3797 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3800 printk("%s: ", zone
->name
);
3802 spin_lock_irqsave(&zone
->lock
, flags
);
3803 for (order
= 0; order
< MAX_ORDER
; order
++) {
3804 struct free_area
*area
= &zone
->free_area
[order
];
3807 nr
[order
] = area
->nr_free
;
3808 total
+= nr
[order
] << order
;
3811 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
3812 if (!list_empty(&area
->free_list
[type
]))
3813 types
[order
] |= 1 << type
;
3816 spin_unlock_irqrestore(&zone
->lock
, flags
);
3817 for (order
= 0; order
< MAX_ORDER
; order
++) {
3818 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
3820 show_migration_types(types
[order
]);
3822 printk("= %lukB\n", K(total
));
3825 hugetlb_show_meminfo();
3827 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
3829 show_swap_cache_info();
3832 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
3834 zoneref
->zone
= zone
;
3835 zoneref
->zone_idx
= zone_idx(zone
);
3839 * Builds allocation fallback zone lists.
3841 * Add all populated zones of a node to the zonelist.
3843 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
3847 enum zone_type zone_type
= MAX_NR_ZONES
;
3851 zone
= pgdat
->node_zones
+ zone_type
;
3852 if (populated_zone(zone
)) {
3853 zoneref_set_zone(zone
,
3854 &zonelist
->_zonerefs
[nr_zones
++]);
3855 check_highest_zone(zone_type
);
3857 } while (zone_type
);
3865 * 0 = automatic detection of better ordering.
3866 * 1 = order by ([node] distance, -zonetype)
3867 * 2 = order by (-zonetype, [node] distance)
3869 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3870 * the same zonelist. So only NUMA can configure this param.
3872 #define ZONELIST_ORDER_DEFAULT 0
3873 #define ZONELIST_ORDER_NODE 1
3874 #define ZONELIST_ORDER_ZONE 2
3876 /* zonelist order in the kernel.
3877 * set_zonelist_order() will set this to NODE or ZONE.
3879 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3880 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
3884 /* The value user specified ....changed by config */
3885 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3886 /* string for sysctl */
3887 #define NUMA_ZONELIST_ORDER_LEN 16
3888 char numa_zonelist_order
[16] = "default";
3891 * interface for configure zonelist ordering.
3892 * command line option "numa_zonelist_order"
3893 * = "[dD]efault - default, automatic configuration.
3894 * = "[nN]ode - order by node locality, then by zone within node
3895 * = "[zZ]one - order by zone, then by locality within zone
3898 static int __parse_numa_zonelist_order(char *s
)
3900 if (*s
== 'd' || *s
== 'D') {
3901 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3902 } else if (*s
== 'n' || *s
== 'N') {
3903 user_zonelist_order
= ZONELIST_ORDER_NODE
;
3904 } else if (*s
== 'z' || *s
== 'Z') {
3905 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
3908 "Ignoring invalid numa_zonelist_order value: "
3915 static __init
int setup_numa_zonelist_order(char *s
)
3922 ret
= __parse_numa_zonelist_order(s
);
3924 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
3928 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
3931 * sysctl handler for numa_zonelist_order
3933 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
3934 void __user
*buffer
, size_t *length
,
3937 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
3939 static DEFINE_MUTEX(zl_order_mutex
);
3941 mutex_lock(&zl_order_mutex
);
3943 if (strlen((char *)table
->data
) >= NUMA_ZONELIST_ORDER_LEN
) {
3947 strcpy(saved_string
, (char *)table
->data
);
3949 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
3953 int oldval
= user_zonelist_order
;
3955 ret
= __parse_numa_zonelist_order((char *)table
->data
);
3958 * bogus value. restore saved string
3960 strncpy((char *)table
->data
, saved_string
,
3961 NUMA_ZONELIST_ORDER_LEN
);
3962 user_zonelist_order
= oldval
;
3963 } else if (oldval
!= user_zonelist_order
) {
3964 mutex_lock(&zonelists_mutex
);
3965 build_all_zonelists(NULL
, NULL
);
3966 mutex_unlock(&zonelists_mutex
);
3970 mutex_unlock(&zl_order_mutex
);
3975 #define MAX_NODE_LOAD (nr_online_nodes)
3976 static int node_load
[MAX_NUMNODES
];
3979 * find_next_best_node - find the next node that should appear in a given node's fallback list
3980 * @node: node whose fallback list we're appending
3981 * @used_node_mask: nodemask_t of already used nodes
3983 * We use a number of factors to determine which is the next node that should
3984 * appear on a given node's fallback list. The node should not have appeared
3985 * already in @node's fallback list, and it should be the next closest node
3986 * according to the distance array (which contains arbitrary distance values
3987 * from each node to each node in the system), and should also prefer nodes
3988 * with no CPUs, since presumably they'll have very little allocation pressure
3989 * on them otherwise.
3990 * It returns -1 if no node is found.
3992 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
3995 int min_val
= INT_MAX
;
3996 int best_node
= NUMA_NO_NODE
;
3997 const struct cpumask
*tmp
= cpumask_of_node(0);
3999 /* Use the local node if we haven't already */
4000 if (!node_isset(node
, *used_node_mask
)) {
4001 node_set(node
, *used_node_mask
);
4005 for_each_node_state(n
, N_MEMORY
) {
4007 /* Don't want a node to appear more than once */
4008 if (node_isset(n
, *used_node_mask
))
4011 /* Use the distance array to find the distance */
4012 val
= node_distance(node
, n
);
4014 /* Penalize nodes under us ("prefer the next node") */
4017 /* Give preference to headless and unused nodes */
4018 tmp
= cpumask_of_node(n
);
4019 if (!cpumask_empty(tmp
))
4020 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
4022 /* Slight preference for less loaded node */
4023 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
4024 val
+= node_load
[n
];
4026 if (val
< min_val
) {
4033 node_set(best_node
, *used_node_mask
);
4040 * Build zonelists ordered by node and zones within node.
4041 * This results in maximum locality--normal zone overflows into local
4042 * DMA zone, if any--but risks exhausting DMA zone.
4044 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
4047 struct zonelist
*zonelist
;
4049 zonelist
= &pgdat
->node_zonelists
[0];
4050 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
4052 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4053 zonelist
->_zonerefs
[j
].zone
= NULL
;
4054 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4058 * Build gfp_thisnode zonelists
4060 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
4063 struct zonelist
*zonelist
;
4065 zonelist
= &pgdat
->node_zonelists
[1];
4066 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4067 zonelist
->_zonerefs
[j
].zone
= NULL
;
4068 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4072 * Build zonelists ordered by zone and nodes within zones.
4073 * This results in conserving DMA zone[s] until all Normal memory is
4074 * exhausted, but results in overflowing to remote node while memory
4075 * may still exist in local DMA zone.
4077 static int node_order
[MAX_NUMNODES
];
4079 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
4082 int zone_type
; /* needs to be signed */
4084 struct zonelist
*zonelist
;
4086 zonelist
= &pgdat
->node_zonelists
[0];
4088 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
4089 for (j
= 0; j
< nr_nodes
; j
++) {
4090 node
= node_order
[j
];
4091 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
4092 if (populated_zone(z
)) {
4094 &zonelist
->_zonerefs
[pos
++]);
4095 check_highest_zone(zone_type
);
4099 zonelist
->_zonerefs
[pos
].zone
= NULL
;
4100 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
4103 #if defined(CONFIG_64BIT)
4105 * Devices that require DMA32/DMA are relatively rare and do not justify a
4106 * penalty to every machine in case the specialised case applies. Default
4107 * to Node-ordering on 64-bit NUMA machines
4109 static int default_zonelist_order(void)
4111 return ZONELIST_ORDER_NODE
;
4115 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4116 * by the kernel. If processes running on node 0 deplete the low memory zone
4117 * then reclaim will occur more frequency increasing stalls and potentially
4118 * be easier to OOM if a large percentage of the zone is under writeback or
4119 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4120 * Hence, default to zone ordering on 32-bit.
4122 static int default_zonelist_order(void)
4124 return ZONELIST_ORDER_ZONE
;
4126 #endif /* CONFIG_64BIT */
4128 static void set_zonelist_order(void)
4130 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
4131 current_zonelist_order
= default_zonelist_order();
4133 current_zonelist_order
= user_zonelist_order
;
4136 static void build_zonelists(pg_data_t
*pgdat
)
4140 nodemask_t used_mask
;
4141 int local_node
, prev_node
;
4142 struct zonelist
*zonelist
;
4143 int order
= current_zonelist_order
;
4145 /* initialize zonelists */
4146 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
4147 zonelist
= pgdat
->node_zonelists
+ i
;
4148 zonelist
->_zonerefs
[0].zone
= NULL
;
4149 zonelist
->_zonerefs
[0].zone_idx
= 0;
4152 /* NUMA-aware ordering of nodes */
4153 local_node
= pgdat
->node_id
;
4154 load
= nr_online_nodes
;
4155 prev_node
= local_node
;
4156 nodes_clear(used_mask
);
4158 memset(node_order
, 0, sizeof(node_order
));
4161 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
4163 * We don't want to pressure a particular node.
4164 * So adding penalty to the first node in same
4165 * distance group to make it round-robin.
4167 if (node_distance(local_node
, node
) !=
4168 node_distance(local_node
, prev_node
))
4169 node_load
[node
] = load
;
4173 if (order
== ZONELIST_ORDER_NODE
)
4174 build_zonelists_in_node_order(pgdat
, node
);
4176 node_order
[j
++] = node
; /* remember order */
4179 if (order
== ZONELIST_ORDER_ZONE
) {
4180 /* calculate node order -- i.e., DMA last! */
4181 build_zonelists_in_zone_order(pgdat
, j
);
4184 build_thisnode_zonelists(pgdat
);
4187 /* Construct the zonelist performance cache - see further mmzone.h */
4188 static void build_zonelist_cache(pg_data_t
*pgdat
)
4190 struct zonelist
*zonelist
;
4191 struct zonelist_cache
*zlc
;
4194 zonelist
= &pgdat
->node_zonelists
[0];
4195 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
4196 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
4197 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
4198 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
4201 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4203 * Return node id of node used for "local" allocations.
4204 * I.e., first node id of first zone in arg node's generic zonelist.
4205 * Used for initializing percpu 'numa_mem', which is used primarily
4206 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4208 int local_memory_node(int node
)
4212 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
4213 gfp_zone(GFP_KERNEL
),
4220 #else /* CONFIG_NUMA */
4222 static void set_zonelist_order(void)
4224 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
4227 static void build_zonelists(pg_data_t
*pgdat
)
4229 int node
, local_node
;
4231 struct zonelist
*zonelist
;
4233 local_node
= pgdat
->node_id
;
4235 zonelist
= &pgdat
->node_zonelists
[0];
4236 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4239 * Now we build the zonelist so that it contains the zones
4240 * of all the other nodes.
4241 * We don't want to pressure a particular node, so when
4242 * building the zones for node N, we make sure that the
4243 * zones coming right after the local ones are those from
4244 * node N+1 (modulo N)
4246 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
4247 if (!node_online(node
))
4249 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4251 for (node
= 0; node
< local_node
; node
++) {
4252 if (!node_online(node
))
4254 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4257 zonelist
->_zonerefs
[j
].zone
= NULL
;
4258 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4261 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
4262 static void build_zonelist_cache(pg_data_t
*pgdat
)
4264 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
4267 #endif /* CONFIG_NUMA */
4270 * Boot pageset table. One per cpu which is going to be used for all
4271 * zones and all nodes. The parameters will be set in such a way
4272 * that an item put on a list will immediately be handed over to
4273 * the buddy list. This is safe since pageset manipulation is done
4274 * with interrupts disabled.
4276 * The boot_pagesets must be kept even after bootup is complete for
4277 * unused processors and/or zones. They do play a role for bootstrapping
4278 * hotplugged processors.
4280 * zoneinfo_show() and maybe other functions do
4281 * not check if the processor is online before following the pageset pointer.
4282 * Other parts of the kernel may not check if the zone is available.
4284 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
4285 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
4286 static void setup_zone_pageset(struct zone
*zone
);
4289 * Global mutex to protect against size modification of zonelists
4290 * as well as to serialize pageset setup for the new populated zone.
4292 DEFINE_MUTEX(zonelists_mutex
);
4294 /* return values int ....just for stop_machine() */
4295 static int __build_all_zonelists(void *data
)
4299 pg_data_t
*self
= data
;
4302 memset(node_load
, 0, sizeof(node_load
));
4305 if (self
&& !node_online(self
->node_id
)) {
4306 build_zonelists(self
);
4307 build_zonelist_cache(self
);
4310 for_each_online_node(nid
) {
4311 pg_data_t
*pgdat
= NODE_DATA(nid
);
4313 build_zonelists(pgdat
);
4314 build_zonelist_cache(pgdat
);
4318 * Initialize the boot_pagesets that are going to be used
4319 * for bootstrapping processors. The real pagesets for
4320 * each zone will be allocated later when the per cpu
4321 * allocator is available.
4323 * boot_pagesets are used also for bootstrapping offline
4324 * cpus if the system is already booted because the pagesets
4325 * are needed to initialize allocators on a specific cpu too.
4326 * F.e. the percpu allocator needs the page allocator which
4327 * needs the percpu allocator in order to allocate its pagesets
4328 * (a chicken-egg dilemma).
4330 for_each_possible_cpu(cpu
) {
4331 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
4333 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4335 * We now know the "local memory node" for each node--
4336 * i.e., the node of the first zone in the generic zonelist.
4337 * Set up numa_mem percpu variable for on-line cpus. During
4338 * boot, only the boot cpu should be on-line; we'll init the
4339 * secondary cpus' numa_mem as they come on-line. During
4340 * node/memory hotplug, we'll fixup all on-line cpus.
4342 if (cpu_online(cpu
))
4343 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
4350 static noinline
void __init
4351 build_all_zonelists_init(void)
4353 __build_all_zonelists(NULL
);
4354 mminit_verify_zonelist();
4355 cpuset_init_current_mems_allowed();
4359 * Called with zonelists_mutex held always
4360 * unless system_state == SYSTEM_BOOTING.
4362 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4363 * [we're only called with non-NULL zone through __meminit paths] and
4364 * (2) call of __init annotated helper build_all_zonelists_init
4365 * [protected by SYSTEM_BOOTING].
4367 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
4369 set_zonelist_order();
4371 if (system_state
== SYSTEM_BOOTING
) {
4372 build_all_zonelists_init();
4374 #ifdef CONFIG_MEMORY_HOTPLUG
4376 setup_zone_pageset(zone
);
4378 /* we have to stop all cpus to guarantee there is no user
4380 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
4381 /* cpuset refresh routine should be here */
4383 vm_total_pages
= nr_free_pagecache_pages();
4385 * Disable grouping by mobility if the number of pages in the
4386 * system is too low to allow the mechanism to work. It would be
4387 * more accurate, but expensive to check per-zone. This check is
4388 * made on memory-hotadd so a system can start with mobility
4389 * disabled and enable it later
4391 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
4392 page_group_by_mobility_disabled
= 1;
4394 page_group_by_mobility_disabled
= 0;
4396 pr_info("Built %i zonelists in %s order, mobility grouping %s. "
4397 "Total pages: %ld\n",
4399 zonelist_order_name
[current_zonelist_order
],
4400 page_group_by_mobility_disabled
? "off" : "on",
4403 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
4408 * Helper functions to size the waitqueue hash table.
4409 * Essentially these want to choose hash table sizes sufficiently
4410 * large so that collisions trying to wait on pages are rare.
4411 * But in fact, the number of active page waitqueues on typical
4412 * systems is ridiculously low, less than 200. So this is even
4413 * conservative, even though it seems large.
4415 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
4416 * waitqueues, i.e. the size of the waitq table given the number of pages.
4418 #define PAGES_PER_WAITQUEUE 256
4420 #ifndef CONFIG_MEMORY_HOTPLUG
4421 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
4423 unsigned long size
= 1;
4425 pages
/= PAGES_PER_WAITQUEUE
;
4427 while (size
< pages
)
4431 * Once we have dozens or even hundreds of threads sleeping
4432 * on IO we've got bigger problems than wait queue collision.
4433 * Limit the size of the wait table to a reasonable size.
4435 size
= min(size
, 4096UL);
4437 return max(size
, 4UL);
4441 * A zone's size might be changed by hot-add, so it is not possible to determine
4442 * a suitable size for its wait_table. So we use the maximum size now.
4444 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
4446 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
4447 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
4448 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
4450 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
4451 * or more by the traditional way. (See above). It equals:
4453 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
4454 * ia64(16K page size) : = ( 8G + 4M)byte.
4455 * powerpc (64K page size) : = (32G +16M)byte.
4457 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
4464 * This is an integer logarithm so that shifts can be used later
4465 * to extract the more random high bits from the multiplicative
4466 * hash function before the remainder is taken.
4468 static inline unsigned long wait_table_bits(unsigned long size
)
4474 * Check if a pageblock contains reserved pages
4476 static int pageblock_is_reserved(unsigned long start_pfn
, unsigned long end_pfn
)
4480 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
4481 if (!pfn_valid_within(pfn
) || PageReserved(pfn_to_page(pfn
)))
4488 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
4489 * of blocks reserved is based on min_wmark_pages(zone). The memory within
4490 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
4491 * higher will lead to a bigger reserve which will get freed as contiguous
4492 * blocks as reclaim kicks in
4494 static void setup_zone_migrate_reserve(struct zone
*zone
)
4496 unsigned long start_pfn
, pfn
, end_pfn
, block_end_pfn
;
4498 unsigned long block_migratetype
;
4503 * Get the start pfn, end pfn and the number of blocks to reserve
4504 * We have to be careful to be aligned to pageblock_nr_pages to
4505 * make sure that we always check pfn_valid for the first page in
4508 start_pfn
= zone
->zone_start_pfn
;
4509 end_pfn
= zone_end_pfn(zone
);
4510 start_pfn
= roundup(start_pfn
, pageblock_nr_pages
);
4511 reserve
= roundup(min_wmark_pages(zone
), pageblock_nr_pages
) >>
4515 * Reserve blocks are generally in place to help high-order atomic
4516 * allocations that are short-lived. A min_free_kbytes value that
4517 * would result in more than 2 reserve blocks for atomic allocations
4518 * is assumed to be in place to help anti-fragmentation for the
4519 * future allocation of hugepages at runtime.
4521 reserve
= min(2, reserve
);
4522 old_reserve
= zone
->nr_migrate_reserve_block
;
4524 /* When memory hot-add, we almost always need to do nothing */
4525 if (reserve
== old_reserve
)
4527 zone
->nr_migrate_reserve_block
= reserve
;
4529 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
4530 if (!early_page_nid_uninitialised(pfn
, zone_to_nid(zone
)))
4533 if (!pfn_valid(pfn
))
4535 page
= pfn_to_page(pfn
);
4537 /* Watch out for overlapping nodes */
4538 if (page_to_nid(page
) != zone_to_nid(zone
))
4541 block_migratetype
= get_pageblock_migratetype(page
);
4543 /* Only test what is necessary when the reserves are not met */
4546 * Blocks with reserved pages will never free, skip
4549 block_end_pfn
= min(pfn
+ pageblock_nr_pages
, end_pfn
);
4550 if (pageblock_is_reserved(pfn
, block_end_pfn
))
4553 /* If this block is reserved, account for it */
4554 if (block_migratetype
== MIGRATE_RESERVE
) {
4559 /* Suitable for reserving if this block is movable */
4560 if (block_migratetype
== MIGRATE_MOVABLE
) {
4561 set_pageblock_migratetype(page
,
4563 move_freepages_block(zone
, page
,
4568 } else if (!old_reserve
) {
4570 * At boot time we don't need to scan the whole zone
4571 * for turning off MIGRATE_RESERVE.
4577 * If the reserve is met and this is a previous reserved block,
4580 if (block_migratetype
== MIGRATE_RESERVE
) {
4581 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4582 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
4588 * Initially all pages are reserved - free ones are freed
4589 * up by free_all_bootmem() once the early boot process is
4590 * done. Non-atomic initialization, single-pass.
4592 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
4593 unsigned long start_pfn
, enum memmap_context context
)
4595 pg_data_t
*pgdat
= NODE_DATA(nid
);
4596 unsigned long end_pfn
= start_pfn
+ size
;
4599 unsigned long nr_initialised
= 0;
4601 if (highest_memmap_pfn
< end_pfn
- 1)
4602 highest_memmap_pfn
= end_pfn
- 1;
4604 z
= &pgdat
->node_zones
[zone
];
4605 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
4607 * There can be holes in boot-time mem_map[]s
4608 * handed to this function. They do not
4609 * exist on hotplugged memory.
4611 if (context
== MEMMAP_EARLY
) {
4612 if (!early_pfn_valid(pfn
))
4614 if (!early_pfn_in_nid(pfn
, nid
))
4616 if (!update_defer_init(pgdat
, pfn
, end_pfn
,
4622 * Mark the block movable so that blocks are reserved for
4623 * movable at startup. This will force kernel allocations
4624 * to reserve their blocks rather than leaking throughout
4625 * the address space during boot when many long-lived
4626 * kernel allocations are made. Later some blocks near
4627 * the start are marked MIGRATE_RESERVE by
4628 * setup_zone_migrate_reserve()
4630 * bitmap is created for zone's valid pfn range. but memmap
4631 * can be created for invalid pages (for alignment)
4632 * check here not to call set_pageblock_migratetype() against
4635 if (!(pfn
& (pageblock_nr_pages
- 1))) {
4636 struct page
*page
= pfn_to_page(pfn
);
4638 __init_single_page(page
, pfn
, zone
, nid
);
4639 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4641 __init_single_pfn(pfn
, zone
, nid
);
4646 static void __meminit
zone_init_free_lists(struct zone
*zone
)
4648 unsigned int order
, t
;
4649 for_each_migratetype_order(order
, t
) {
4650 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
4651 zone
->free_area
[order
].nr_free
= 0;
4655 #ifndef __HAVE_ARCH_MEMMAP_INIT
4656 #define memmap_init(size, nid, zone, start_pfn) \
4657 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4660 static int zone_batchsize(struct zone
*zone
)
4666 * The per-cpu-pages pools are set to around 1000th of the
4667 * size of the zone. But no more than 1/2 of a meg.
4669 * OK, so we don't know how big the cache is. So guess.
4671 batch
= zone
->managed_pages
/ 1024;
4672 if (batch
* PAGE_SIZE
> 512 * 1024)
4673 batch
= (512 * 1024) / PAGE_SIZE
;
4674 batch
/= 4; /* We effectively *= 4 below */
4679 * Clamp the batch to a 2^n - 1 value. Having a power
4680 * of 2 value was found to be more likely to have
4681 * suboptimal cache aliasing properties in some cases.
4683 * For example if 2 tasks are alternately allocating
4684 * batches of pages, one task can end up with a lot
4685 * of pages of one half of the possible page colors
4686 * and the other with pages of the other colors.
4688 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
4693 /* The deferral and batching of frees should be suppressed under NOMMU
4696 * The problem is that NOMMU needs to be able to allocate large chunks
4697 * of contiguous memory as there's no hardware page translation to
4698 * assemble apparent contiguous memory from discontiguous pages.
4700 * Queueing large contiguous runs of pages for batching, however,
4701 * causes the pages to actually be freed in smaller chunks. As there
4702 * can be a significant delay between the individual batches being
4703 * recycled, this leads to the once large chunks of space being
4704 * fragmented and becoming unavailable for high-order allocations.
4711 * pcp->high and pcp->batch values are related and dependent on one another:
4712 * ->batch must never be higher then ->high.
4713 * The following function updates them in a safe manner without read side
4716 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4717 * those fields changing asynchronously (acording the the above rule).
4719 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4720 * outside of boot time (or some other assurance that no concurrent updaters
4723 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
4724 unsigned long batch
)
4726 /* start with a fail safe value for batch */
4730 /* Update high, then batch, in order */
4737 /* a companion to pageset_set_high() */
4738 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
4740 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
4743 static void pageset_init(struct per_cpu_pageset
*p
)
4745 struct per_cpu_pages
*pcp
;
4748 memset(p
, 0, sizeof(*p
));
4752 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
4753 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
4756 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
4759 pageset_set_batch(p
, batch
);
4763 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4764 * to the value high for the pageset p.
4766 static void pageset_set_high(struct per_cpu_pageset
*p
,
4769 unsigned long batch
= max(1UL, high
/ 4);
4770 if ((high
/ 4) > (PAGE_SHIFT
* 8))
4771 batch
= PAGE_SHIFT
* 8;
4773 pageset_update(&p
->pcp
, high
, batch
);
4776 static void pageset_set_high_and_batch(struct zone
*zone
,
4777 struct per_cpu_pageset
*pcp
)
4779 if (percpu_pagelist_fraction
)
4780 pageset_set_high(pcp
,
4781 (zone
->managed_pages
/
4782 percpu_pagelist_fraction
));
4784 pageset_set_batch(pcp
, zone_batchsize(zone
));
4787 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
4789 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
4792 pageset_set_high_and_batch(zone
, pcp
);
4795 static void __meminit
setup_zone_pageset(struct zone
*zone
)
4798 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
4799 for_each_possible_cpu(cpu
)
4800 zone_pageset_init(zone
, cpu
);
4804 * Allocate per cpu pagesets and initialize them.
4805 * Before this call only boot pagesets were available.
4807 void __init
setup_per_cpu_pageset(void)
4811 for_each_populated_zone(zone
)
4812 setup_zone_pageset(zone
);
4815 static noinline __init_refok
4816 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
4822 * The per-page waitqueue mechanism uses hashed waitqueues
4825 zone
->wait_table_hash_nr_entries
=
4826 wait_table_hash_nr_entries(zone_size_pages
);
4827 zone
->wait_table_bits
=
4828 wait_table_bits(zone
->wait_table_hash_nr_entries
);
4829 alloc_size
= zone
->wait_table_hash_nr_entries
4830 * sizeof(wait_queue_head_t
);
4832 if (!slab_is_available()) {
4833 zone
->wait_table
= (wait_queue_head_t
*)
4834 memblock_virt_alloc_node_nopanic(
4835 alloc_size
, zone
->zone_pgdat
->node_id
);
4838 * This case means that a zone whose size was 0 gets new memory
4839 * via memory hot-add.
4840 * But it may be the case that a new node was hot-added. In
4841 * this case vmalloc() will not be able to use this new node's
4842 * memory - this wait_table must be initialized to use this new
4843 * node itself as well.
4844 * To use this new node's memory, further consideration will be
4847 zone
->wait_table
= vmalloc(alloc_size
);
4849 if (!zone
->wait_table
)
4852 for (i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
4853 init_waitqueue_head(zone
->wait_table
+ i
);
4858 static __meminit
void zone_pcp_init(struct zone
*zone
)
4861 * per cpu subsystem is not up at this point. The following code
4862 * relies on the ability of the linker to provide the
4863 * offset of a (static) per cpu variable into the per cpu area.
4865 zone
->pageset
= &boot_pageset
;
4867 if (populated_zone(zone
))
4868 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
4869 zone
->name
, zone
->present_pages
,
4870 zone_batchsize(zone
));
4873 int __meminit
init_currently_empty_zone(struct zone
*zone
,
4874 unsigned long zone_start_pfn
,
4876 enum memmap_context context
)
4878 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
4880 ret
= zone_wait_table_init(zone
, size
);
4883 pgdat
->nr_zones
= zone_idx(zone
) + 1;
4885 zone
->zone_start_pfn
= zone_start_pfn
;
4887 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
4888 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4890 (unsigned long)zone_idx(zone
),
4891 zone_start_pfn
, (zone_start_pfn
+ size
));
4893 zone_init_free_lists(zone
);
4898 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4899 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4902 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4904 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
4905 struct mminit_pfnnid_cache
*state
)
4907 unsigned long start_pfn
, end_pfn
;
4910 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
4911 return state
->last_nid
;
4913 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
4915 state
->last_start
= start_pfn
;
4916 state
->last_end
= end_pfn
;
4917 state
->last_nid
= nid
;
4922 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4925 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
4926 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4927 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
4929 * If an architecture guarantees that all ranges registered contain no holes
4930 * and may be freed, this this function may be used instead of calling
4931 * memblock_free_early_nid() manually.
4933 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
4935 unsigned long start_pfn
, end_pfn
;
4938 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
4939 start_pfn
= min(start_pfn
, max_low_pfn
);
4940 end_pfn
= min(end_pfn
, max_low_pfn
);
4942 if (start_pfn
< end_pfn
)
4943 memblock_free_early_nid(PFN_PHYS(start_pfn
),
4944 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
4950 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4951 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4953 * If an architecture guarantees that all ranges registered contain no holes and may
4954 * be freed, this function may be used instead of calling memory_present() manually.
4956 void __init
sparse_memory_present_with_active_regions(int nid
)
4958 unsigned long start_pfn
, end_pfn
;
4961 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
4962 memory_present(this_nid
, start_pfn
, end_pfn
);
4966 * get_pfn_range_for_nid - Return the start and end page frames for a node
4967 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4968 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
4969 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
4971 * It returns the start and end page frame of a node based on information
4972 * provided by memblock_set_node(). If called for a node
4973 * with no available memory, a warning is printed and the start and end
4976 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
4977 unsigned long *start_pfn
, unsigned long *end_pfn
)
4979 unsigned long this_start_pfn
, this_end_pfn
;
4985 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
4986 *start_pfn
= min(*start_pfn
, this_start_pfn
);
4987 *end_pfn
= max(*end_pfn
, this_end_pfn
);
4990 if (*start_pfn
== -1UL)
4995 * This finds a zone that can be used for ZONE_MOVABLE pages. The
4996 * assumption is made that zones within a node are ordered in monotonic
4997 * increasing memory addresses so that the "highest" populated zone is used
4999 static void __init
find_usable_zone_for_movable(void)
5002 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
5003 if (zone_index
== ZONE_MOVABLE
)
5006 if (arch_zone_highest_possible_pfn
[zone_index
] >
5007 arch_zone_lowest_possible_pfn
[zone_index
])
5011 VM_BUG_ON(zone_index
== -1);
5012 movable_zone
= zone_index
;
5016 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5017 * because it is sized independent of architecture. Unlike the other zones,
5018 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5019 * in each node depending on the size of each node and how evenly kernelcore
5020 * is distributed. This helper function adjusts the zone ranges
5021 * provided by the architecture for a given node by using the end of the
5022 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5023 * zones within a node are in order of monotonic increases memory addresses
5025 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
5026 unsigned long zone_type
,
5027 unsigned long node_start_pfn
,
5028 unsigned long node_end_pfn
,
5029 unsigned long *zone_start_pfn
,
5030 unsigned long *zone_end_pfn
)
5032 /* Only adjust if ZONE_MOVABLE is on this node */
5033 if (zone_movable_pfn
[nid
]) {
5034 /* Size ZONE_MOVABLE */
5035 if (zone_type
== ZONE_MOVABLE
) {
5036 *zone_start_pfn
= zone_movable_pfn
[nid
];
5037 *zone_end_pfn
= min(node_end_pfn
,
5038 arch_zone_highest_possible_pfn
[movable_zone
]);
5040 /* Adjust for ZONE_MOVABLE starting within this range */
5041 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
5042 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
5043 *zone_end_pfn
= zone_movable_pfn
[nid
];
5045 /* Check if this whole range is within ZONE_MOVABLE */
5046 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
5047 *zone_start_pfn
= *zone_end_pfn
;
5052 * Return the number of pages a zone spans in a node, including holes
5053 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5055 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5056 unsigned long zone_type
,
5057 unsigned long node_start_pfn
,
5058 unsigned long node_end_pfn
,
5059 unsigned long *ignored
)
5061 unsigned long zone_start_pfn
, zone_end_pfn
;
5063 /* When hotadd a new node, the node should be empty */
5064 if (!node_start_pfn
&& !node_end_pfn
)
5067 /* Get the start and end of the zone */
5068 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
5069 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
5070 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5071 node_start_pfn
, node_end_pfn
,
5072 &zone_start_pfn
, &zone_end_pfn
);
5074 /* Check that this node has pages within the zone's required range */
5075 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
5078 /* Move the zone boundaries inside the node if necessary */
5079 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
5080 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
5082 /* Return the spanned pages */
5083 return zone_end_pfn
- zone_start_pfn
;
5087 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5088 * then all holes in the requested range will be accounted for.
5090 unsigned long __meminit
__absent_pages_in_range(int nid
,
5091 unsigned long range_start_pfn
,
5092 unsigned long range_end_pfn
)
5094 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
5095 unsigned long start_pfn
, end_pfn
;
5098 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5099 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
5100 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
5101 nr_absent
-= end_pfn
- start_pfn
;
5107 * absent_pages_in_range - Return number of page frames in holes within a range
5108 * @start_pfn: The start PFN to start searching for holes
5109 * @end_pfn: The end PFN to stop searching for holes
5111 * It returns the number of pages frames in memory holes within a range.
5113 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
5114 unsigned long end_pfn
)
5116 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
5119 /* Return the number of page frames in holes in a zone on a node */
5120 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5121 unsigned long zone_type
,
5122 unsigned long node_start_pfn
,
5123 unsigned long node_end_pfn
,
5124 unsigned long *ignored
)
5126 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
5127 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
5128 unsigned long zone_start_pfn
, zone_end_pfn
;
5130 /* When hotadd a new node, the node should be empty */
5131 if (!node_start_pfn
&& !node_end_pfn
)
5134 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
5135 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
5137 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5138 node_start_pfn
, node_end_pfn
,
5139 &zone_start_pfn
, &zone_end_pfn
);
5140 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
5143 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5144 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5145 unsigned long zone_type
,
5146 unsigned long node_start_pfn
,
5147 unsigned long node_end_pfn
,
5148 unsigned long *zones_size
)
5150 return zones_size
[zone_type
];
5153 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5154 unsigned long zone_type
,
5155 unsigned long node_start_pfn
,
5156 unsigned long node_end_pfn
,
5157 unsigned long *zholes_size
)
5162 return zholes_size
[zone_type
];
5165 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5167 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
5168 unsigned long node_start_pfn
,
5169 unsigned long node_end_pfn
,
5170 unsigned long *zones_size
,
5171 unsigned long *zholes_size
)
5173 unsigned long realtotalpages
= 0, totalpages
= 0;
5176 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5177 struct zone
*zone
= pgdat
->node_zones
+ i
;
5178 unsigned long size
, real_size
;
5180 size
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
5184 real_size
= size
- zone_absent_pages_in_node(pgdat
->node_id
, i
,
5185 node_start_pfn
, node_end_pfn
,
5187 zone
->spanned_pages
= size
;
5188 zone
->present_pages
= real_size
;
5191 realtotalpages
+= real_size
;
5194 pgdat
->node_spanned_pages
= totalpages
;
5195 pgdat
->node_present_pages
= realtotalpages
;
5196 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
5200 #ifndef CONFIG_SPARSEMEM
5202 * Calculate the size of the zone->blockflags rounded to an unsigned long
5203 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5204 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5205 * round what is now in bits to nearest long in bits, then return it in
5208 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
5210 unsigned long usemapsize
;
5212 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
5213 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
5214 usemapsize
= usemapsize
>> pageblock_order
;
5215 usemapsize
*= NR_PAGEBLOCK_BITS
;
5216 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
5218 return usemapsize
/ 8;
5221 static void __init
setup_usemap(struct pglist_data
*pgdat
,
5223 unsigned long zone_start_pfn
,
5224 unsigned long zonesize
)
5226 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
5227 zone
->pageblock_flags
= NULL
;
5229 zone
->pageblock_flags
=
5230 memblock_virt_alloc_node_nopanic(usemapsize
,
5234 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
5235 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
5236 #endif /* CONFIG_SPARSEMEM */
5238 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5240 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5241 void __paginginit
set_pageblock_order(void)
5245 /* Check that pageblock_nr_pages has not already been setup */
5246 if (pageblock_order
)
5249 if (HPAGE_SHIFT
> PAGE_SHIFT
)
5250 order
= HUGETLB_PAGE_ORDER
;
5252 order
= MAX_ORDER
- 1;
5255 * Assume the largest contiguous order of interest is a huge page.
5256 * This value may be variable depending on boot parameters on IA64 and
5259 pageblock_order
= order
;
5261 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5264 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5265 * is unused as pageblock_order is set at compile-time. See
5266 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5269 void __paginginit
set_pageblock_order(void)
5273 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5275 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
5276 unsigned long present_pages
)
5278 unsigned long pages
= spanned_pages
;
5281 * Provide a more accurate estimation if there are holes within
5282 * the zone and SPARSEMEM is in use. If there are holes within the
5283 * zone, each populated memory region may cost us one or two extra
5284 * memmap pages due to alignment because memmap pages for each
5285 * populated regions may not naturally algined on page boundary.
5286 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5288 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
5289 IS_ENABLED(CONFIG_SPARSEMEM
))
5290 pages
= present_pages
;
5292 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
5296 * Set up the zone data structures:
5297 * - mark all pages reserved
5298 * - mark all memory queues empty
5299 * - clear the memory bitmaps
5301 * NOTE: pgdat should get zeroed by caller.
5303 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
,
5304 unsigned long node_start_pfn
, unsigned long node_end_pfn
)
5307 int nid
= pgdat
->node_id
;
5308 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
5311 pgdat_resize_init(pgdat
);
5312 #ifdef CONFIG_NUMA_BALANCING
5313 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
5314 pgdat
->numabalancing_migrate_nr_pages
= 0;
5315 pgdat
->numabalancing_migrate_next_window
= jiffies
;
5317 init_waitqueue_head(&pgdat
->kswapd_wait
);
5318 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
5319 pgdat_page_ext_init(pgdat
);
5321 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5322 struct zone
*zone
= pgdat
->node_zones
+ j
;
5323 unsigned long size
, realsize
, freesize
, memmap_pages
;
5325 size
= zone
->spanned_pages
;
5326 realsize
= freesize
= zone
->present_pages
;
5329 * Adjust freesize so that it accounts for how much memory
5330 * is used by this zone for memmap. This affects the watermark
5331 * and per-cpu initialisations
5333 memmap_pages
= calc_memmap_size(size
, realsize
);
5334 if (!is_highmem_idx(j
)) {
5335 if (freesize
>= memmap_pages
) {
5336 freesize
-= memmap_pages
;
5339 " %s zone: %lu pages used for memmap\n",
5340 zone_names
[j
], memmap_pages
);
5343 " %s zone: %lu pages exceeds freesize %lu\n",
5344 zone_names
[j
], memmap_pages
, freesize
);
5347 /* Account for reserved pages */
5348 if (j
== 0 && freesize
> dma_reserve
) {
5349 freesize
-= dma_reserve
;
5350 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
5351 zone_names
[0], dma_reserve
);
5354 if (!is_highmem_idx(j
))
5355 nr_kernel_pages
+= freesize
;
5356 /* Charge for highmem memmap if there are enough kernel pages */
5357 else if (nr_kernel_pages
> memmap_pages
* 2)
5358 nr_kernel_pages
-= memmap_pages
;
5359 nr_all_pages
+= freesize
;
5362 * Set an approximate value for lowmem here, it will be adjusted
5363 * when the bootmem allocator frees pages into the buddy system.
5364 * And all highmem pages will be managed by the buddy system.
5366 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
5369 zone
->min_unmapped_pages
= (freesize
*sysctl_min_unmapped_ratio
)
5371 zone
->min_slab_pages
= (freesize
* sysctl_min_slab_ratio
) / 100;
5373 zone
->name
= zone_names
[j
];
5374 spin_lock_init(&zone
->lock
);
5375 spin_lock_init(&zone
->lru_lock
);
5376 zone_seqlock_init(zone
);
5377 zone
->zone_pgdat
= pgdat
;
5378 zone_pcp_init(zone
);
5380 /* For bootup, initialized properly in watermark setup */
5381 mod_zone_page_state(zone
, NR_ALLOC_BATCH
, zone
->managed_pages
);
5383 lruvec_init(&zone
->lruvec
);
5387 set_pageblock_order();
5388 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
5389 ret
= init_currently_empty_zone(zone
, zone_start_pfn
,
5390 size
, MEMMAP_EARLY
);
5392 memmap_init(size
, nid
, j
, zone_start_pfn
);
5393 zone_start_pfn
+= size
;
5397 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
5399 /* Skip empty nodes */
5400 if (!pgdat
->node_spanned_pages
)
5403 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5404 /* ia64 gets its own node_mem_map, before this, without bootmem */
5405 if (!pgdat
->node_mem_map
) {
5406 unsigned long size
, start
, end
;
5410 * The zone's endpoints aren't required to be MAX_ORDER
5411 * aligned but the node_mem_map endpoints must be in order
5412 * for the buddy allocator to function correctly.
5414 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
5415 end
= pgdat_end_pfn(pgdat
);
5416 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
5417 size
= (end
- start
) * sizeof(struct page
);
5418 map
= alloc_remap(pgdat
->node_id
, size
);
5420 map
= memblock_virt_alloc_node_nopanic(size
,
5422 pgdat
->node_mem_map
= map
+ (pgdat
->node_start_pfn
- start
);
5424 #ifndef CONFIG_NEED_MULTIPLE_NODES
5426 * With no DISCONTIG, the global mem_map is just set as node 0's
5428 if (pgdat
== NODE_DATA(0)) {
5429 mem_map
= NODE_DATA(0)->node_mem_map
;
5430 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5431 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
5432 mem_map
-= (pgdat
->node_start_pfn
- ARCH_PFN_OFFSET
);
5433 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5436 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
5439 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
5440 unsigned long node_start_pfn
, unsigned long *zholes_size
)
5442 pg_data_t
*pgdat
= NODE_DATA(nid
);
5443 unsigned long start_pfn
= 0;
5444 unsigned long end_pfn
= 0;
5446 /* pg_data_t should be reset to zero when it's allocated */
5447 WARN_ON(pgdat
->nr_zones
|| pgdat
->classzone_idx
);
5449 reset_deferred_meminit(pgdat
);
5450 pgdat
->node_id
= nid
;
5451 pgdat
->node_start_pfn
= node_start_pfn
;
5452 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5453 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
5454 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
5455 (u64
)start_pfn
<< PAGE_SHIFT
, ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
5457 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
5458 zones_size
, zholes_size
);
5460 alloc_node_mem_map(pgdat
);
5461 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5462 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
5463 nid
, (unsigned long)pgdat
,
5464 (unsigned long)pgdat
->node_mem_map
);
5467 free_area_init_core(pgdat
, start_pfn
, end_pfn
);
5470 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5472 #if MAX_NUMNODES > 1
5474 * Figure out the number of possible node ids.
5476 void __init
setup_nr_node_ids(void)
5479 unsigned int highest
= 0;
5481 for_each_node_mask(node
, node_possible_map
)
5483 nr_node_ids
= highest
+ 1;
5488 * node_map_pfn_alignment - determine the maximum internode alignment
5490 * This function should be called after node map is populated and sorted.
5491 * It calculates the maximum power of two alignment which can distinguish
5494 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5495 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5496 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5497 * shifted, 1GiB is enough and this function will indicate so.
5499 * This is used to test whether pfn -> nid mapping of the chosen memory
5500 * model has fine enough granularity to avoid incorrect mapping for the
5501 * populated node map.
5503 * Returns the determined alignment in pfn's. 0 if there is no alignment
5504 * requirement (single node).
5506 unsigned long __init
node_map_pfn_alignment(void)
5508 unsigned long accl_mask
= 0, last_end
= 0;
5509 unsigned long start
, end
, mask
;
5513 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
5514 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
5521 * Start with a mask granular enough to pin-point to the
5522 * start pfn and tick off bits one-by-one until it becomes
5523 * too coarse to separate the current node from the last.
5525 mask
= ~((1 << __ffs(start
)) - 1);
5526 while (mask
&& last_end
<= (start
& (mask
<< 1)))
5529 /* accumulate all internode masks */
5533 /* convert mask to number of pages */
5534 return ~accl_mask
+ 1;
5537 /* Find the lowest pfn for a node */
5538 static unsigned long __init
find_min_pfn_for_node(int nid
)
5540 unsigned long min_pfn
= ULONG_MAX
;
5541 unsigned long start_pfn
;
5544 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
5545 min_pfn
= min(min_pfn
, start_pfn
);
5547 if (min_pfn
== ULONG_MAX
) {
5549 "Could not find start_pfn for node %d\n", nid
);
5557 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5559 * It returns the minimum PFN based on information provided via
5560 * memblock_set_node().
5562 unsigned long __init
find_min_pfn_with_active_regions(void)
5564 return find_min_pfn_for_node(MAX_NUMNODES
);
5568 * early_calculate_totalpages()
5569 * Sum pages in active regions for movable zone.
5570 * Populate N_MEMORY for calculating usable_nodes.
5572 static unsigned long __init
early_calculate_totalpages(void)
5574 unsigned long totalpages
= 0;
5575 unsigned long start_pfn
, end_pfn
;
5578 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
5579 unsigned long pages
= end_pfn
- start_pfn
;
5581 totalpages
+= pages
;
5583 node_set_state(nid
, N_MEMORY
);
5589 * Find the PFN the Movable zone begins in each node. Kernel memory
5590 * is spread evenly between nodes as long as the nodes have enough
5591 * memory. When they don't, some nodes will have more kernelcore than
5594 static void __init
find_zone_movable_pfns_for_nodes(void)
5597 unsigned long usable_startpfn
;
5598 unsigned long kernelcore_node
, kernelcore_remaining
;
5599 /* save the state before borrow the nodemask */
5600 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
5601 unsigned long totalpages
= early_calculate_totalpages();
5602 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
5603 struct memblock_region
*r
;
5605 /* Need to find movable_zone earlier when movable_node is specified. */
5606 find_usable_zone_for_movable();
5609 * If movable_node is specified, ignore kernelcore and movablecore
5612 if (movable_node_is_enabled()) {
5613 for_each_memblock(memory
, r
) {
5614 if (!memblock_is_hotpluggable(r
))
5619 usable_startpfn
= PFN_DOWN(r
->base
);
5620 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
5621 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
5629 * If movablecore=nn[KMG] was specified, calculate what size of
5630 * kernelcore that corresponds so that memory usable for
5631 * any allocation type is evenly spread. If both kernelcore
5632 * and movablecore are specified, then the value of kernelcore
5633 * will be used for required_kernelcore if it's greater than
5634 * what movablecore would have allowed.
5636 if (required_movablecore
) {
5637 unsigned long corepages
;
5640 * Round-up so that ZONE_MOVABLE is at least as large as what
5641 * was requested by the user
5643 required_movablecore
=
5644 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
5645 corepages
= totalpages
- required_movablecore
;
5647 required_kernelcore
= max(required_kernelcore
, corepages
);
5650 /* If kernelcore was not specified, there is no ZONE_MOVABLE */
5651 if (!required_kernelcore
)
5654 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5655 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
5658 /* Spread kernelcore memory as evenly as possible throughout nodes */
5659 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5660 for_each_node_state(nid
, N_MEMORY
) {
5661 unsigned long start_pfn
, end_pfn
;
5664 * Recalculate kernelcore_node if the division per node
5665 * now exceeds what is necessary to satisfy the requested
5666 * amount of memory for the kernel
5668 if (required_kernelcore
< kernelcore_node
)
5669 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5672 * As the map is walked, we track how much memory is usable
5673 * by the kernel using kernelcore_remaining. When it is
5674 * 0, the rest of the node is usable by ZONE_MOVABLE
5676 kernelcore_remaining
= kernelcore_node
;
5678 /* Go through each range of PFNs within this node */
5679 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5680 unsigned long size_pages
;
5682 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
5683 if (start_pfn
>= end_pfn
)
5686 /* Account for what is only usable for kernelcore */
5687 if (start_pfn
< usable_startpfn
) {
5688 unsigned long kernel_pages
;
5689 kernel_pages
= min(end_pfn
, usable_startpfn
)
5692 kernelcore_remaining
-= min(kernel_pages
,
5693 kernelcore_remaining
);
5694 required_kernelcore
-= min(kernel_pages
,
5695 required_kernelcore
);
5697 /* Continue if range is now fully accounted */
5698 if (end_pfn
<= usable_startpfn
) {
5701 * Push zone_movable_pfn to the end so
5702 * that if we have to rebalance
5703 * kernelcore across nodes, we will
5704 * not double account here
5706 zone_movable_pfn
[nid
] = end_pfn
;
5709 start_pfn
= usable_startpfn
;
5713 * The usable PFN range for ZONE_MOVABLE is from
5714 * start_pfn->end_pfn. Calculate size_pages as the
5715 * number of pages used as kernelcore
5717 size_pages
= end_pfn
- start_pfn
;
5718 if (size_pages
> kernelcore_remaining
)
5719 size_pages
= kernelcore_remaining
;
5720 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
5723 * Some kernelcore has been met, update counts and
5724 * break if the kernelcore for this node has been
5727 required_kernelcore
-= min(required_kernelcore
,
5729 kernelcore_remaining
-= size_pages
;
5730 if (!kernelcore_remaining
)
5736 * If there is still required_kernelcore, we do another pass with one
5737 * less node in the count. This will push zone_movable_pfn[nid] further
5738 * along on the nodes that still have memory until kernelcore is
5742 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
5746 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5747 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
5748 zone_movable_pfn
[nid
] =
5749 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
5752 /* restore the node_state */
5753 node_states
[N_MEMORY
] = saved_node_state
;
5756 /* Any regular or high memory on that node ? */
5757 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
5759 enum zone_type zone_type
;
5761 if (N_MEMORY
== N_NORMAL_MEMORY
)
5764 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
5765 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
5766 if (populated_zone(zone
)) {
5767 node_set_state(nid
, N_HIGH_MEMORY
);
5768 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
5769 zone_type
<= ZONE_NORMAL
)
5770 node_set_state(nid
, N_NORMAL_MEMORY
);
5777 * free_area_init_nodes - Initialise all pg_data_t and zone data
5778 * @max_zone_pfn: an array of max PFNs for each zone
5780 * This will call free_area_init_node() for each active node in the system.
5781 * Using the page ranges provided by memblock_set_node(), the size of each
5782 * zone in each node and their holes is calculated. If the maximum PFN
5783 * between two adjacent zones match, it is assumed that the zone is empty.
5784 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5785 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5786 * starts where the previous one ended. For example, ZONE_DMA32 starts
5787 * at arch_max_dma_pfn.
5789 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
5791 unsigned long start_pfn
, end_pfn
;
5794 /* Record where the zone boundaries are */
5795 memset(arch_zone_lowest_possible_pfn
, 0,
5796 sizeof(arch_zone_lowest_possible_pfn
));
5797 memset(arch_zone_highest_possible_pfn
, 0,
5798 sizeof(arch_zone_highest_possible_pfn
));
5799 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
5800 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
5801 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
5802 if (i
== ZONE_MOVABLE
)
5804 arch_zone_lowest_possible_pfn
[i
] =
5805 arch_zone_highest_possible_pfn
[i
-1];
5806 arch_zone_highest_possible_pfn
[i
] =
5807 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
5809 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
5810 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
5812 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
5813 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
5814 find_zone_movable_pfns_for_nodes();
5816 /* Print out the zone ranges */
5817 pr_info("Zone ranges:\n");
5818 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5819 if (i
== ZONE_MOVABLE
)
5821 pr_info(" %-8s ", zone_names
[i
]);
5822 if (arch_zone_lowest_possible_pfn
[i
] ==
5823 arch_zone_highest_possible_pfn
[i
])
5826 pr_cont("[mem %#018Lx-%#018Lx]\n",
5827 (u64
)arch_zone_lowest_possible_pfn
[i
]
5829 ((u64
)arch_zone_highest_possible_pfn
[i
]
5830 << PAGE_SHIFT
) - 1);
5833 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5834 pr_info("Movable zone start for each node\n");
5835 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
5836 if (zone_movable_pfn
[i
])
5837 pr_info(" Node %d: %#018Lx\n", i
,
5838 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
5841 /* Print out the early node map */
5842 pr_info("Early memory node ranges\n");
5843 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
5844 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
5845 (u64
)start_pfn
<< PAGE_SHIFT
,
5846 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
5848 /* Initialise every node */
5849 mminit_verify_pageflags_layout();
5850 setup_nr_node_ids();
5851 for_each_online_node(nid
) {
5852 pg_data_t
*pgdat
= NODE_DATA(nid
);
5853 free_area_init_node(nid
, NULL
,
5854 find_min_pfn_for_node(nid
), NULL
);
5856 /* Any memory on that node */
5857 if (pgdat
->node_present_pages
)
5858 node_set_state(nid
, N_MEMORY
);
5859 check_for_memory(pgdat
, nid
);
5863 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
5865 unsigned long long coremem
;
5869 coremem
= memparse(p
, &p
);
5870 *core
= coremem
>> PAGE_SHIFT
;
5872 /* Paranoid check that UL is enough for the coremem value */
5873 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
5879 * kernelcore=size sets the amount of memory for use for allocations that
5880 * cannot be reclaimed or migrated.
5882 static int __init
cmdline_parse_kernelcore(char *p
)
5884 return cmdline_parse_core(p
, &required_kernelcore
);
5888 * movablecore=size sets the amount of memory for use for allocations that
5889 * can be reclaimed or migrated.
5891 static int __init
cmdline_parse_movablecore(char *p
)
5893 return cmdline_parse_core(p
, &required_movablecore
);
5896 early_param("kernelcore", cmdline_parse_kernelcore
);
5897 early_param("movablecore", cmdline_parse_movablecore
);
5899 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5901 void adjust_managed_page_count(struct page
*page
, long count
)
5903 spin_lock(&managed_page_count_lock
);
5904 page_zone(page
)->managed_pages
+= count
;
5905 totalram_pages
+= count
;
5906 #ifdef CONFIG_HIGHMEM
5907 if (PageHighMem(page
))
5908 totalhigh_pages
+= count
;
5910 spin_unlock(&managed_page_count_lock
);
5912 EXPORT_SYMBOL(adjust_managed_page_count
);
5914 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
5917 unsigned long pages
= 0;
5919 start
= (void *)PAGE_ALIGN((unsigned long)start
);
5920 end
= (void *)((unsigned long)end
& PAGE_MASK
);
5921 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
5922 if ((unsigned int)poison
<= 0xFF)
5923 memset(pos
, poison
, PAGE_SIZE
);
5924 free_reserved_page(virt_to_page(pos
));
5928 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
5929 s
, pages
<< (PAGE_SHIFT
- 10), start
, end
);
5933 EXPORT_SYMBOL(free_reserved_area
);
5935 #ifdef CONFIG_HIGHMEM
5936 void free_highmem_page(struct page
*page
)
5938 __free_reserved_page(page
);
5940 page_zone(page
)->managed_pages
++;
5946 void __init
mem_init_print_info(const char *str
)
5948 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
5949 unsigned long init_code_size
, init_data_size
;
5951 physpages
= get_num_physpages();
5952 codesize
= _etext
- _stext
;
5953 datasize
= _edata
- _sdata
;
5954 rosize
= __end_rodata
- __start_rodata
;
5955 bss_size
= __bss_stop
- __bss_start
;
5956 init_data_size
= __init_end
- __init_begin
;
5957 init_code_size
= _einittext
- _sinittext
;
5960 * Detect special cases and adjust section sizes accordingly:
5961 * 1) .init.* may be embedded into .data sections
5962 * 2) .init.text.* may be out of [__init_begin, __init_end],
5963 * please refer to arch/tile/kernel/vmlinux.lds.S.
5964 * 3) .rodata.* may be embedded into .text or .data sections.
5966 #define adj_init_size(start, end, size, pos, adj) \
5968 if (start <= pos && pos < end && size > adj) \
5972 adj_init_size(__init_begin
, __init_end
, init_data_size
,
5973 _sinittext
, init_code_size
);
5974 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
5975 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
5976 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
5977 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
5979 #undef adj_init_size
5981 pr_info("Memory: %luK/%luK available "
5982 "(%luK kernel code, %luK rwdata, %luK rodata, "
5983 "%luK init, %luK bss, %luK reserved, %luK cma-reserved"
5984 #ifdef CONFIG_HIGHMEM
5988 nr_free_pages() << (PAGE_SHIFT
-10), physpages
<< (PAGE_SHIFT
-10),
5989 codesize
>> 10, datasize
>> 10, rosize
>> 10,
5990 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
5991 (physpages
- totalram_pages
- totalcma_pages
) << (PAGE_SHIFT
-10),
5992 totalcma_pages
<< (PAGE_SHIFT
-10),
5993 #ifdef CONFIG_HIGHMEM
5994 totalhigh_pages
<< (PAGE_SHIFT
-10),
5996 str
? ", " : "", str
? str
: "");
6000 * set_dma_reserve - set the specified number of pages reserved in the first zone
6001 * @new_dma_reserve: The number of pages to mark reserved
6003 * The per-cpu batchsize and zone watermarks are determined by present_pages.
6004 * In the DMA zone, a significant percentage may be consumed by kernel image
6005 * and other unfreeable allocations which can skew the watermarks badly. This
6006 * function may optionally be used to account for unfreeable pages in the
6007 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6008 * smaller per-cpu batchsize.
6010 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
6012 dma_reserve
= new_dma_reserve
;
6015 void __init
free_area_init(unsigned long *zones_size
)
6017 free_area_init_node(0, zones_size
,
6018 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
6021 static int page_alloc_cpu_notify(struct notifier_block
*self
,
6022 unsigned long action
, void *hcpu
)
6024 int cpu
= (unsigned long)hcpu
;
6026 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
6027 lru_add_drain_cpu(cpu
);
6031 * Spill the event counters of the dead processor
6032 * into the current processors event counters.
6033 * This artificially elevates the count of the current
6036 vm_events_fold_cpu(cpu
);
6039 * Zero the differential counters of the dead processor
6040 * so that the vm statistics are consistent.
6042 * This is only okay since the processor is dead and cannot
6043 * race with what we are doing.
6045 cpu_vm_stats_fold(cpu
);
6050 void __init
page_alloc_init(void)
6052 hotcpu_notifier(page_alloc_cpu_notify
, 0);
6056 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
6057 * or min_free_kbytes changes.
6059 static void calculate_totalreserve_pages(void)
6061 struct pglist_data
*pgdat
;
6062 unsigned long reserve_pages
= 0;
6063 enum zone_type i
, j
;
6065 for_each_online_pgdat(pgdat
) {
6066 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6067 struct zone
*zone
= pgdat
->node_zones
+ i
;
6070 /* Find valid and maximum lowmem_reserve in the zone */
6071 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
6072 if (zone
->lowmem_reserve
[j
] > max
)
6073 max
= zone
->lowmem_reserve
[j
];
6076 /* we treat the high watermark as reserved pages. */
6077 max
+= high_wmark_pages(zone
);
6079 if (max
> zone
->managed_pages
)
6080 max
= zone
->managed_pages
;
6081 reserve_pages
+= max
;
6083 * Lowmem reserves are not available to
6084 * GFP_HIGHUSER page cache allocations and
6085 * kswapd tries to balance zones to their high
6086 * watermark. As a result, neither should be
6087 * regarded as dirtyable memory, to prevent a
6088 * situation where reclaim has to clean pages
6089 * in order to balance the zones.
6091 zone
->dirty_balance_reserve
= max
;
6094 dirty_balance_reserve
= reserve_pages
;
6095 totalreserve_pages
= reserve_pages
;
6099 * setup_per_zone_lowmem_reserve - called whenever
6100 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone
6101 * has a correct pages reserved value, so an adequate number of
6102 * pages are left in the zone after a successful __alloc_pages().
6104 static void setup_per_zone_lowmem_reserve(void)
6106 struct pglist_data
*pgdat
;
6107 enum zone_type j
, idx
;
6109 for_each_online_pgdat(pgdat
) {
6110 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6111 struct zone
*zone
= pgdat
->node_zones
+ j
;
6112 unsigned long managed_pages
= zone
->managed_pages
;
6114 zone
->lowmem_reserve
[j
] = 0;
6118 struct zone
*lower_zone
;
6122 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
6123 sysctl_lowmem_reserve_ratio
[idx
] = 1;
6125 lower_zone
= pgdat
->node_zones
+ idx
;
6126 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
6127 sysctl_lowmem_reserve_ratio
[idx
];
6128 managed_pages
+= lower_zone
->managed_pages
;
6133 /* update totalreserve_pages */
6134 calculate_totalreserve_pages();
6137 static void __setup_per_zone_wmarks(void)
6139 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
6140 unsigned long lowmem_pages
= 0;
6142 unsigned long flags
;
6144 /* Calculate total number of !ZONE_HIGHMEM pages */
6145 for_each_zone(zone
) {
6146 if (!is_highmem(zone
))
6147 lowmem_pages
+= zone
->managed_pages
;
6150 for_each_zone(zone
) {
6153 spin_lock_irqsave(&zone
->lock
, flags
);
6154 tmp
= (u64
)pages_min
* zone
->managed_pages
;
6155 do_div(tmp
, lowmem_pages
);
6156 if (is_highmem(zone
)) {
6158 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6159 * need highmem pages, so cap pages_min to a small
6162 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6163 * deltas control asynch page reclaim, and so should
6164 * not be capped for highmem.
6166 unsigned long min_pages
;
6168 min_pages
= zone
->managed_pages
/ 1024;
6169 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
6170 zone
->watermark
[WMARK_MIN
] = min_pages
;
6173 * If it's a lowmem zone, reserve a number of pages
6174 * proportionate to the zone's size.
6176 zone
->watermark
[WMARK_MIN
] = tmp
;
6179 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + (tmp
>> 2);
6180 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + (tmp
>> 1);
6182 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
6183 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
6184 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
6186 setup_zone_migrate_reserve(zone
);
6187 spin_unlock_irqrestore(&zone
->lock
, flags
);
6190 /* update totalreserve_pages */
6191 calculate_totalreserve_pages();
6195 * setup_per_zone_wmarks - called when min_free_kbytes changes
6196 * or when memory is hot-{added|removed}
6198 * Ensures that the watermark[min,low,high] values for each zone are set
6199 * correctly with respect to min_free_kbytes.
6201 void setup_per_zone_wmarks(void)
6203 mutex_lock(&zonelists_mutex
);
6204 __setup_per_zone_wmarks();
6205 mutex_unlock(&zonelists_mutex
);
6209 * The inactive anon list should be small enough that the VM never has to
6210 * do too much work, but large enough that each inactive page has a chance
6211 * to be referenced again before it is swapped out.
6213 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
6214 * INACTIVE_ANON pages on this zone's LRU, maintained by the
6215 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
6216 * the anonymous pages are kept on the inactive list.
6219 * memory ratio inactive anon
6220 * -------------------------------------
6229 static void __meminit
calculate_zone_inactive_ratio(struct zone
*zone
)
6231 unsigned int gb
, ratio
;
6233 /* Zone size in gigabytes */
6234 gb
= zone
->managed_pages
>> (30 - PAGE_SHIFT
);
6236 ratio
= int_sqrt(10 * gb
);
6240 zone
->inactive_ratio
= ratio
;
6243 static void __meminit
setup_per_zone_inactive_ratio(void)
6248 calculate_zone_inactive_ratio(zone
);
6252 * Initialise min_free_kbytes.
6254 * For small machines we want it small (128k min). For large machines
6255 * we want it large (64MB max). But it is not linear, because network
6256 * bandwidth does not increase linearly with machine size. We use
6258 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6259 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6275 int __meminit
init_per_zone_wmark_min(void)
6277 unsigned long lowmem_kbytes
;
6278 int new_min_free_kbytes
;
6280 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
6281 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
6283 if (new_min_free_kbytes
> user_min_free_kbytes
) {
6284 min_free_kbytes
= new_min_free_kbytes
;
6285 if (min_free_kbytes
< 128)
6286 min_free_kbytes
= 128;
6287 if (min_free_kbytes
> 65536)
6288 min_free_kbytes
= 65536;
6290 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6291 new_min_free_kbytes
, user_min_free_kbytes
);
6293 setup_per_zone_wmarks();
6294 refresh_zone_stat_thresholds();
6295 setup_per_zone_lowmem_reserve();
6296 setup_per_zone_inactive_ratio();
6299 module_init(init_per_zone_wmark_min
)
6302 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6303 * that we can call two helper functions whenever min_free_kbytes
6306 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
6307 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6311 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6316 user_min_free_kbytes
= min_free_kbytes
;
6317 setup_per_zone_wmarks();
6323 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6324 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6329 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6334 zone
->min_unmapped_pages
= (zone
->managed_pages
*
6335 sysctl_min_unmapped_ratio
) / 100;
6339 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6340 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6345 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6350 zone
->min_slab_pages
= (zone
->managed_pages
*
6351 sysctl_min_slab_ratio
) / 100;
6357 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6358 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6359 * whenever sysctl_lowmem_reserve_ratio changes.
6361 * The reserve ratio obviously has absolutely no relation with the
6362 * minimum watermarks. The lowmem reserve ratio can only make sense
6363 * if in function of the boot time zone sizes.
6365 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6366 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6368 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6369 setup_per_zone_lowmem_reserve();
6374 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6375 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6376 * pagelist can have before it gets flushed back to buddy allocator.
6378 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
6379 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6382 int old_percpu_pagelist_fraction
;
6385 mutex_lock(&pcp_batch_high_lock
);
6386 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
6388 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6389 if (!write
|| ret
< 0)
6392 /* Sanity checking to avoid pcp imbalance */
6393 if (percpu_pagelist_fraction
&&
6394 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
6395 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
6401 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
6404 for_each_populated_zone(zone
) {
6407 for_each_possible_cpu(cpu
)
6408 pageset_set_high_and_batch(zone
,
6409 per_cpu_ptr(zone
->pageset
, cpu
));
6412 mutex_unlock(&pcp_batch_high_lock
);
6417 int hashdist
= HASHDIST_DEFAULT
;
6419 static int __init
set_hashdist(char *str
)
6423 hashdist
= simple_strtoul(str
, &str
, 0);
6426 __setup("hashdist=", set_hashdist
);
6430 * allocate a large system hash table from bootmem
6431 * - it is assumed that the hash table must contain an exact power-of-2
6432 * quantity of entries
6433 * - limit is the number of hash buckets, not the total allocation size
6435 void *__init
alloc_large_system_hash(const char *tablename
,
6436 unsigned long bucketsize
,
6437 unsigned long numentries
,
6440 unsigned int *_hash_shift
,
6441 unsigned int *_hash_mask
,
6442 unsigned long low_limit
,
6443 unsigned long high_limit
)
6445 unsigned long long max
= high_limit
;
6446 unsigned long log2qty
, size
;
6449 /* allow the kernel cmdline to have a say */
6451 /* round applicable memory size up to nearest megabyte */
6452 numentries
= nr_kernel_pages
;
6454 /* It isn't necessary when PAGE_SIZE >= 1MB */
6455 if (PAGE_SHIFT
< 20)
6456 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
6458 /* limit to 1 bucket per 2^scale bytes of low memory */
6459 if (scale
> PAGE_SHIFT
)
6460 numentries
>>= (scale
- PAGE_SHIFT
);
6462 numentries
<<= (PAGE_SHIFT
- scale
);
6464 /* Make sure we've got at least a 0-order allocation.. */
6465 if (unlikely(flags
& HASH_SMALL
)) {
6466 /* Makes no sense without HASH_EARLY */
6467 WARN_ON(!(flags
& HASH_EARLY
));
6468 if (!(numentries
>> *_hash_shift
)) {
6469 numentries
= 1UL << *_hash_shift
;
6470 BUG_ON(!numentries
);
6472 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
6473 numentries
= PAGE_SIZE
/ bucketsize
;
6475 numentries
= roundup_pow_of_two(numentries
);
6477 /* limit allocation size to 1/16 total memory by default */
6479 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
6480 do_div(max
, bucketsize
);
6482 max
= min(max
, 0x80000000ULL
);
6484 if (numentries
< low_limit
)
6485 numentries
= low_limit
;
6486 if (numentries
> max
)
6489 log2qty
= ilog2(numentries
);
6492 size
= bucketsize
<< log2qty
;
6493 if (flags
& HASH_EARLY
)
6494 table
= memblock_virt_alloc_nopanic(size
, 0);
6496 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
6499 * If bucketsize is not a power-of-two, we may free
6500 * some pages at the end of hash table which
6501 * alloc_pages_exact() automatically does
6503 if (get_order(size
) < MAX_ORDER
) {
6504 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
6505 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
6508 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
6511 panic("Failed to allocate %s hash table\n", tablename
);
6513 printk(KERN_INFO
"%s hash table entries: %ld (order: %d, %lu bytes)\n",
6516 ilog2(size
) - PAGE_SHIFT
,
6520 *_hash_shift
= log2qty
;
6522 *_hash_mask
= (1 << log2qty
) - 1;
6527 /* Return a pointer to the bitmap storing bits affecting a block of pages */
6528 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
6531 #ifdef CONFIG_SPARSEMEM
6532 return __pfn_to_section(pfn
)->pageblock_flags
;
6534 return zone
->pageblock_flags
;
6535 #endif /* CONFIG_SPARSEMEM */
6538 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
6540 #ifdef CONFIG_SPARSEMEM
6541 pfn
&= (PAGES_PER_SECTION
-1);
6542 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6544 pfn
= pfn
- round_down(zone
->zone_start_pfn
, pageblock_nr_pages
);
6545 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6546 #endif /* CONFIG_SPARSEMEM */
6550 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
6551 * @page: The page within the block of interest
6552 * @pfn: The target page frame number
6553 * @end_bitidx: The last bit of interest to retrieve
6554 * @mask: mask of bits that the caller is interested in
6556 * Return: pageblock_bits flags
6558 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
6559 unsigned long end_bitidx
,
6563 unsigned long *bitmap
;
6564 unsigned long bitidx
, word_bitidx
;
6567 zone
= page_zone(page
);
6568 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6569 bitidx
= pfn_to_bitidx(zone
, pfn
);
6570 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6571 bitidx
&= (BITS_PER_LONG
-1);
6573 word
= bitmap
[word_bitidx
];
6574 bitidx
+= end_bitidx
;
6575 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
6579 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
6580 * @page: The page within the block of interest
6581 * @flags: The flags to set
6582 * @pfn: The target page frame number
6583 * @end_bitidx: The last bit of interest
6584 * @mask: mask of bits that the caller is interested in
6586 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
6588 unsigned long end_bitidx
,
6592 unsigned long *bitmap
;
6593 unsigned long bitidx
, word_bitidx
;
6594 unsigned long old_word
, word
;
6596 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
6598 zone
= page_zone(page
);
6599 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6600 bitidx
= pfn_to_bitidx(zone
, pfn
);
6601 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6602 bitidx
&= (BITS_PER_LONG
-1);
6604 VM_BUG_ON_PAGE(!zone_spans_pfn(zone
, pfn
), page
);
6606 bitidx
+= end_bitidx
;
6607 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
6608 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
6610 word
= READ_ONCE(bitmap
[word_bitidx
]);
6612 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
6613 if (word
== old_word
)
6620 * This function checks whether pageblock includes unmovable pages or not.
6621 * If @count is not zero, it is okay to include less @count unmovable pages
6623 * PageLRU check without isolation or lru_lock could race so that
6624 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6625 * expect this function should be exact.
6627 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
6628 bool skip_hwpoisoned_pages
)
6630 unsigned long pfn
, iter
, found
;
6634 * For avoiding noise data, lru_add_drain_all() should be called
6635 * If ZONE_MOVABLE, the zone never contains unmovable pages
6637 if (zone_idx(zone
) == ZONE_MOVABLE
)
6639 mt
= get_pageblock_migratetype(page
);
6640 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
6643 pfn
= page_to_pfn(page
);
6644 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
6645 unsigned long check
= pfn
+ iter
;
6647 if (!pfn_valid_within(check
))
6650 page
= pfn_to_page(check
);
6653 * Hugepages are not in LRU lists, but they're movable.
6654 * We need not scan over tail pages bacause we don't
6655 * handle each tail page individually in migration.
6657 if (PageHuge(page
)) {
6658 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
6663 * We can't use page_count without pin a page
6664 * because another CPU can free compound page.
6665 * This check already skips compound tails of THP
6666 * because their page->_count is zero at all time.
6668 if (!atomic_read(&page
->_count
)) {
6669 if (PageBuddy(page
))
6670 iter
+= (1 << page_order(page
)) - 1;
6675 * The HWPoisoned page may be not in buddy system, and
6676 * page_count() is not 0.
6678 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
6684 * If there are RECLAIMABLE pages, we need to check
6685 * it. But now, memory offline itself doesn't call
6686 * shrink_node_slabs() and it still to be fixed.
6689 * If the page is not RAM, page_count()should be 0.
6690 * we don't need more check. This is an _used_ not-movable page.
6692 * The problematic thing here is PG_reserved pages. PG_reserved
6693 * is set to both of a memory hole page and a _used_ kernel
6702 bool is_pageblock_removable_nolock(struct page
*page
)
6708 * We have to be careful here because we are iterating over memory
6709 * sections which are not zone aware so we might end up outside of
6710 * the zone but still within the section.
6711 * We have to take care about the node as well. If the node is offline
6712 * its NODE_DATA will be NULL - see page_zone.
6714 if (!node_online(page_to_nid(page
)))
6717 zone
= page_zone(page
);
6718 pfn
= page_to_pfn(page
);
6719 if (!zone_spans_pfn(zone
, pfn
))
6722 return !has_unmovable_pages(zone
, page
, 0, true);
6727 static unsigned long pfn_max_align_down(unsigned long pfn
)
6729 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6730 pageblock_nr_pages
) - 1);
6733 static unsigned long pfn_max_align_up(unsigned long pfn
)
6735 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6736 pageblock_nr_pages
));
6739 /* [start, end) must belong to a single zone. */
6740 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
6741 unsigned long start
, unsigned long end
)
6743 /* This function is based on compact_zone() from compaction.c. */
6744 unsigned long nr_reclaimed
;
6745 unsigned long pfn
= start
;
6746 unsigned int tries
= 0;
6751 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
6752 if (fatal_signal_pending(current
)) {
6757 if (list_empty(&cc
->migratepages
)) {
6758 cc
->nr_migratepages
= 0;
6759 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
6765 } else if (++tries
== 5) {
6766 ret
= ret
< 0 ? ret
: -EBUSY
;
6770 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
6772 cc
->nr_migratepages
-= nr_reclaimed
;
6774 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
6775 NULL
, 0, cc
->mode
, MR_CMA
);
6778 putback_movable_pages(&cc
->migratepages
);
6785 * alloc_contig_range() -- tries to allocate given range of pages
6786 * @start: start PFN to allocate
6787 * @end: one-past-the-last PFN to allocate
6788 * @migratetype: migratetype of the underlaying pageblocks (either
6789 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
6790 * in range must have the same migratetype and it must
6791 * be either of the two.
6793 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
6794 * aligned, however it's the caller's responsibility to guarantee that
6795 * we are the only thread that changes migrate type of pageblocks the
6798 * The PFN range must belong to a single zone.
6800 * Returns zero on success or negative error code. On success all
6801 * pages which PFN is in [start, end) are allocated for the caller and
6802 * need to be freed with free_contig_range().
6804 int alloc_contig_range(unsigned long start
, unsigned long end
,
6805 unsigned migratetype
)
6807 unsigned long outer_start
, outer_end
;
6810 struct compact_control cc
= {
6811 .nr_migratepages
= 0,
6813 .zone
= page_zone(pfn_to_page(start
)),
6814 .mode
= MIGRATE_SYNC
,
6815 .ignore_skip_hint
= true,
6817 INIT_LIST_HEAD(&cc
.migratepages
);
6820 * What we do here is we mark all pageblocks in range as
6821 * MIGRATE_ISOLATE. Because pageblock and max order pages may
6822 * have different sizes, and due to the way page allocator
6823 * work, we align the range to biggest of the two pages so
6824 * that page allocator won't try to merge buddies from
6825 * different pageblocks and change MIGRATE_ISOLATE to some
6826 * other migration type.
6828 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
6829 * migrate the pages from an unaligned range (ie. pages that
6830 * we are interested in). This will put all the pages in
6831 * range back to page allocator as MIGRATE_ISOLATE.
6833 * When this is done, we take the pages in range from page
6834 * allocator removing them from the buddy system. This way
6835 * page allocator will never consider using them.
6837 * This lets us mark the pageblocks back as
6838 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
6839 * aligned range but not in the unaligned, original range are
6840 * put back to page allocator so that buddy can use them.
6843 ret
= start_isolate_page_range(pfn_max_align_down(start
),
6844 pfn_max_align_up(end
), migratetype
,
6849 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
6854 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
6855 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
6856 * more, all pages in [start, end) are free in page allocator.
6857 * What we are going to do is to allocate all pages from
6858 * [start, end) (that is remove them from page allocator).
6860 * The only problem is that pages at the beginning and at the
6861 * end of interesting range may be not aligned with pages that
6862 * page allocator holds, ie. they can be part of higher order
6863 * pages. Because of this, we reserve the bigger range and
6864 * once this is done free the pages we are not interested in.
6866 * We don't have to hold zone->lock here because the pages are
6867 * isolated thus they won't get removed from buddy.
6870 lru_add_drain_all();
6871 drain_all_pages(cc
.zone
);
6874 outer_start
= start
;
6875 while (!PageBuddy(pfn_to_page(outer_start
))) {
6876 if (++order
>= MAX_ORDER
) {
6880 outer_start
&= ~0UL << order
;
6883 /* Make sure the range is really isolated. */
6884 if (test_pages_isolated(outer_start
, end
, false)) {
6885 pr_info("%s: [%lx, %lx) PFNs busy\n",
6886 __func__
, outer_start
, end
);
6891 /* Grab isolated pages from freelists. */
6892 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
6898 /* Free head and tail (if any) */
6899 if (start
!= outer_start
)
6900 free_contig_range(outer_start
, start
- outer_start
);
6901 if (end
!= outer_end
)
6902 free_contig_range(end
, outer_end
- end
);
6905 undo_isolate_page_range(pfn_max_align_down(start
),
6906 pfn_max_align_up(end
), migratetype
);
6910 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
6912 unsigned int count
= 0;
6914 for (; nr_pages
--; pfn
++) {
6915 struct page
*page
= pfn_to_page(pfn
);
6917 count
+= page_count(page
) != 1;
6920 WARN(count
!= 0, "%d pages are still in use!\n", count
);
6924 #ifdef CONFIG_MEMORY_HOTPLUG
6926 * The zone indicated has a new number of managed_pages; batch sizes and percpu
6927 * page high values need to be recalulated.
6929 void __meminit
zone_pcp_update(struct zone
*zone
)
6932 mutex_lock(&pcp_batch_high_lock
);
6933 for_each_possible_cpu(cpu
)
6934 pageset_set_high_and_batch(zone
,
6935 per_cpu_ptr(zone
->pageset
, cpu
));
6936 mutex_unlock(&pcp_batch_high_lock
);
6940 void zone_pcp_reset(struct zone
*zone
)
6942 unsigned long flags
;
6944 struct per_cpu_pageset
*pset
;
6946 /* avoid races with drain_pages() */
6947 local_irq_save(flags
);
6948 if (zone
->pageset
!= &boot_pageset
) {
6949 for_each_online_cpu(cpu
) {
6950 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
6951 drain_zonestat(zone
, pset
);
6953 free_percpu(zone
->pageset
);
6954 zone
->pageset
= &boot_pageset
;
6956 local_irq_restore(flags
);
6959 #ifdef CONFIG_MEMORY_HOTREMOVE
6961 * All pages in the range must be isolated before calling this.
6964 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
6968 unsigned int order
, i
;
6970 unsigned long flags
;
6971 /* find the first valid pfn */
6972 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
6977 zone
= page_zone(pfn_to_page(pfn
));
6978 spin_lock_irqsave(&zone
->lock
, flags
);
6980 while (pfn
< end_pfn
) {
6981 if (!pfn_valid(pfn
)) {
6985 page
= pfn_to_page(pfn
);
6987 * The HWPoisoned page may be not in buddy system, and
6988 * page_count() is not 0.
6990 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
6992 SetPageReserved(page
);
6996 BUG_ON(page_count(page
));
6997 BUG_ON(!PageBuddy(page
));
6998 order
= page_order(page
);
6999 #ifdef CONFIG_DEBUG_VM
7000 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
7001 pfn
, 1 << order
, end_pfn
);
7003 list_del(&page
->lru
);
7004 rmv_page_order(page
);
7005 zone
->free_area
[order
].nr_free
--;
7006 for (i
= 0; i
< (1 << order
); i
++)
7007 SetPageReserved((page
+i
));
7008 pfn
+= (1 << order
);
7010 spin_unlock_irqrestore(&zone
->lock
, flags
);
7014 #ifdef CONFIG_MEMORY_FAILURE
7015 bool is_free_buddy_page(struct page
*page
)
7017 struct zone
*zone
= page_zone(page
);
7018 unsigned long pfn
= page_to_pfn(page
);
7019 unsigned long flags
;
7022 spin_lock_irqsave(&zone
->lock
, flags
);
7023 for (order
= 0; order
< MAX_ORDER
; order
++) {
7024 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
7026 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
7029 spin_unlock_irqrestore(&zone
->lock
, flags
);
7031 return order
< MAX_ORDER
;