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
;
129 * A cached value of the page's pageblock's migratetype, used when the page is
130 * put on a pcplist. Used to avoid the pageblock migratetype lookup when
131 * freeing from pcplists in most cases, at the cost of possibly becoming stale.
132 * Also the migratetype set in the page does not necessarily match the pcplist
133 * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
134 * other index - this ensures that it will be put on the correct CMA freelist.
136 static inline int get_pcppage_migratetype(struct page
*page
)
141 static inline void set_pcppage_migratetype(struct page
*page
, int migratetype
)
143 page
->index
= migratetype
;
146 #ifdef CONFIG_PM_SLEEP
148 * The following functions are used by the suspend/hibernate code to temporarily
149 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
150 * while devices are suspended. To avoid races with the suspend/hibernate code,
151 * they should always be called with pm_mutex held (gfp_allowed_mask also should
152 * only be modified with pm_mutex held, unless the suspend/hibernate code is
153 * guaranteed not to run in parallel with that modification).
156 static gfp_t saved_gfp_mask
;
158 void pm_restore_gfp_mask(void)
160 WARN_ON(!mutex_is_locked(&pm_mutex
));
161 if (saved_gfp_mask
) {
162 gfp_allowed_mask
= saved_gfp_mask
;
167 void pm_restrict_gfp_mask(void)
169 WARN_ON(!mutex_is_locked(&pm_mutex
));
170 WARN_ON(saved_gfp_mask
);
171 saved_gfp_mask
= gfp_allowed_mask
;
172 gfp_allowed_mask
&= ~GFP_IOFS
;
175 bool pm_suspended_storage(void)
177 if ((gfp_allowed_mask
& GFP_IOFS
) == GFP_IOFS
)
181 #endif /* CONFIG_PM_SLEEP */
183 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
184 int pageblock_order __read_mostly
;
187 static void __free_pages_ok(struct page
*page
, unsigned int order
);
190 * results with 256, 32 in the lowmem_reserve sysctl:
191 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
192 * 1G machine -> (16M dma, 784M normal, 224M high)
193 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
194 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
195 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA
197 * TBD: should special case ZONE_DMA32 machines here - in those we normally
198 * don't need any ZONE_NORMAL reservation
200 int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1] = {
201 #ifdef CONFIG_ZONE_DMA
204 #ifdef CONFIG_ZONE_DMA32
207 #ifdef CONFIG_HIGHMEM
213 EXPORT_SYMBOL(totalram_pages
);
215 static char * const zone_names
[MAX_NR_ZONES
] = {
216 #ifdef CONFIG_ZONE_DMA
219 #ifdef CONFIG_ZONE_DMA32
223 #ifdef CONFIG_HIGHMEM
227 #ifdef CONFIG_ZONE_DEVICE
232 int min_free_kbytes
= 1024;
233 int user_min_free_kbytes
= -1;
235 static unsigned long __meminitdata nr_kernel_pages
;
236 static unsigned long __meminitdata nr_all_pages
;
237 static unsigned long __meminitdata dma_reserve
;
239 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
240 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
241 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
242 static unsigned long __initdata required_kernelcore
;
243 static unsigned long __initdata required_movablecore
;
244 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
246 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
248 EXPORT_SYMBOL(movable_zone
);
249 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
252 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
253 int nr_online_nodes __read_mostly
= 1;
254 EXPORT_SYMBOL(nr_node_ids
);
255 EXPORT_SYMBOL(nr_online_nodes
);
258 int page_group_by_mobility_disabled __read_mostly
;
260 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
261 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
263 pgdat
->first_deferred_pfn
= ULONG_MAX
;
266 /* Returns true if the struct page for the pfn is uninitialised */
267 static inline bool __meminit
early_page_uninitialised(unsigned long pfn
)
269 if (pfn
>= NODE_DATA(early_pfn_to_nid(pfn
))->first_deferred_pfn
)
275 static inline bool early_page_nid_uninitialised(unsigned long pfn
, int nid
)
277 if (pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
284 * Returns false when the remaining initialisation should be deferred until
285 * later in the boot cycle when it can be parallelised.
287 static inline bool update_defer_init(pg_data_t
*pgdat
,
288 unsigned long pfn
, unsigned long zone_end
,
289 unsigned long *nr_initialised
)
291 /* Always populate low zones for address-contrained allocations */
292 if (zone_end
< pgdat_end_pfn(pgdat
))
295 /* Initialise at least 2G of the highest zone */
297 if (*nr_initialised
> (2UL << (30 - PAGE_SHIFT
)) &&
298 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
299 pgdat
->first_deferred_pfn
= pfn
;
306 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
310 static inline bool early_page_uninitialised(unsigned long pfn
)
315 static inline bool early_page_nid_uninitialised(unsigned long pfn
, int nid
)
320 static inline bool update_defer_init(pg_data_t
*pgdat
,
321 unsigned long pfn
, unsigned long zone_end
,
322 unsigned long *nr_initialised
)
329 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
331 if (unlikely(page_group_by_mobility_disabled
&&
332 migratetype
< MIGRATE_PCPTYPES
))
333 migratetype
= MIGRATE_UNMOVABLE
;
335 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
336 PB_migrate
, PB_migrate_end
);
339 #ifdef CONFIG_DEBUG_VM
340 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
344 unsigned long pfn
= page_to_pfn(page
);
345 unsigned long sp
, start_pfn
;
348 seq
= zone_span_seqbegin(zone
);
349 start_pfn
= zone
->zone_start_pfn
;
350 sp
= zone
->spanned_pages
;
351 if (!zone_spans_pfn(zone
, pfn
))
353 } while (zone_span_seqretry(zone
, seq
));
356 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
357 pfn
, zone_to_nid(zone
), zone
->name
,
358 start_pfn
, start_pfn
+ sp
);
363 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
365 if (!pfn_valid_within(page_to_pfn(page
)))
367 if (zone
!= page_zone(page
))
373 * Temporary debugging check for pages not lying within a given zone.
375 static int bad_range(struct zone
*zone
, struct page
*page
)
377 if (page_outside_zone_boundaries(zone
, page
))
379 if (!page_is_consistent(zone
, page
))
385 static inline int bad_range(struct zone
*zone
, struct page
*page
)
391 static void bad_page(struct page
*page
, const char *reason
,
392 unsigned long bad_flags
)
394 static unsigned long resume
;
395 static unsigned long nr_shown
;
396 static unsigned long nr_unshown
;
398 /* Don't complain about poisoned pages */
399 if (PageHWPoison(page
)) {
400 page_mapcount_reset(page
); /* remove PageBuddy */
405 * Allow a burst of 60 reports, then keep quiet for that minute;
406 * or allow a steady drip of one report per second.
408 if (nr_shown
== 60) {
409 if (time_before(jiffies
, resume
)) {
415 "BUG: Bad page state: %lu messages suppressed\n",
422 resume
= jiffies
+ 60 * HZ
;
424 printk(KERN_ALERT
"BUG: Bad page state in process %s pfn:%05lx\n",
425 current
->comm
, page_to_pfn(page
));
426 dump_page_badflags(page
, reason
, bad_flags
);
431 /* Leave bad fields for debug, except PageBuddy could make trouble */
432 page_mapcount_reset(page
); /* remove PageBuddy */
433 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
437 * Higher-order pages are called "compound pages". They are structured thusly:
439 * The first PAGE_SIZE page is called the "head page".
441 * The remaining PAGE_SIZE pages are called "tail pages".
443 * All pages have PG_compound set. All tail pages have their ->first_page
444 * pointing at the head page.
446 * The first tail page's ->lru.next holds the address of the compound page's
447 * put_page() function. Its ->lru.prev holds the order of allocation.
448 * This usage means that zero-order pages may not be compound.
451 static void free_compound_page(struct page
*page
)
453 __free_pages_ok(page
, compound_order(page
));
456 void prep_compound_page(struct page
*page
, unsigned long order
)
459 int nr_pages
= 1 << order
;
461 set_compound_page_dtor(page
, free_compound_page
);
462 set_compound_order(page
, order
);
464 for (i
= 1; i
< nr_pages
; i
++) {
465 struct page
*p
= page
+ i
;
466 set_page_count(p
, 0);
467 p
->first_page
= page
;
468 /* Make sure p->first_page is always valid for PageTail() */
474 #ifdef CONFIG_DEBUG_PAGEALLOC
475 unsigned int _debug_guardpage_minorder
;
476 bool _debug_pagealloc_enabled __read_mostly
;
477 bool _debug_guardpage_enabled __read_mostly
;
479 static int __init
early_debug_pagealloc(char *buf
)
484 if (strcmp(buf
, "on") == 0)
485 _debug_pagealloc_enabled
= true;
489 early_param("debug_pagealloc", early_debug_pagealloc
);
491 static bool need_debug_guardpage(void)
493 /* If we don't use debug_pagealloc, we don't need guard page */
494 if (!debug_pagealloc_enabled())
500 static void init_debug_guardpage(void)
502 if (!debug_pagealloc_enabled())
505 _debug_guardpage_enabled
= true;
508 struct page_ext_operations debug_guardpage_ops
= {
509 .need
= need_debug_guardpage
,
510 .init
= init_debug_guardpage
,
513 static int __init
debug_guardpage_minorder_setup(char *buf
)
517 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
518 printk(KERN_ERR
"Bad debug_guardpage_minorder value\n");
521 _debug_guardpage_minorder
= res
;
522 printk(KERN_INFO
"Setting debug_guardpage_minorder to %lu\n", res
);
525 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
527 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
528 unsigned int order
, int migratetype
)
530 struct page_ext
*page_ext
;
532 if (!debug_guardpage_enabled())
535 page_ext
= lookup_page_ext(page
);
536 __set_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
538 INIT_LIST_HEAD(&page
->lru
);
539 set_page_private(page
, order
);
540 /* Guard pages are not available for any usage */
541 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
544 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
545 unsigned int order
, int migratetype
)
547 struct page_ext
*page_ext
;
549 if (!debug_guardpage_enabled())
552 page_ext
= lookup_page_ext(page
);
553 __clear_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
555 set_page_private(page
, 0);
556 if (!is_migrate_isolate(migratetype
))
557 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
560 struct page_ext_operations debug_guardpage_ops
= { NULL
, };
561 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
562 unsigned int order
, int migratetype
) {}
563 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
564 unsigned int order
, int migratetype
) {}
567 static inline void set_page_order(struct page
*page
, unsigned int order
)
569 set_page_private(page
, order
);
570 __SetPageBuddy(page
);
573 static inline void rmv_page_order(struct page
*page
)
575 __ClearPageBuddy(page
);
576 set_page_private(page
, 0);
580 * This function checks whether a page is free && is the buddy
581 * we can do coalesce a page and its buddy if
582 * (a) the buddy is not in a hole &&
583 * (b) the buddy is in the buddy system &&
584 * (c) a page and its buddy have the same order &&
585 * (d) a page and its buddy are in the same zone.
587 * For recording whether a page is in the buddy system, we set ->_mapcount
588 * PAGE_BUDDY_MAPCOUNT_VALUE.
589 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
590 * serialized by zone->lock.
592 * For recording page's order, we use page_private(page).
594 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
597 if (!pfn_valid_within(page_to_pfn(buddy
)))
600 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
601 if (page_zone_id(page
) != page_zone_id(buddy
))
604 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
609 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
611 * zone check is done late to avoid uselessly
612 * calculating zone/node ids for pages that could
615 if (page_zone_id(page
) != page_zone_id(buddy
))
618 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
626 * Freeing function for a buddy system allocator.
628 * The concept of a buddy system is to maintain direct-mapped table
629 * (containing bit values) for memory blocks of various "orders".
630 * The bottom level table contains the map for the smallest allocatable
631 * units of memory (here, pages), and each level above it describes
632 * pairs of units from the levels below, hence, "buddies".
633 * At a high level, all that happens here is marking the table entry
634 * at the bottom level available, and propagating the changes upward
635 * as necessary, plus some accounting needed to play nicely with other
636 * parts of the VM system.
637 * At each level, we keep a list of pages, which are heads of continuous
638 * free pages of length of (1 << order) and marked with _mapcount
639 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
641 * So when we are allocating or freeing one, we can derive the state of the
642 * other. That is, if we allocate a small block, and both were
643 * free, the remainder of the region must be split into blocks.
644 * If a block is freed, and its buddy is also free, then this
645 * triggers coalescing into a block of larger size.
650 static inline void __free_one_page(struct page
*page
,
652 struct zone
*zone
, unsigned int order
,
655 unsigned long page_idx
;
656 unsigned long combined_idx
;
657 unsigned long uninitialized_var(buddy_idx
);
659 int max_order
= MAX_ORDER
;
661 VM_BUG_ON(!zone_is_initialized(zone
));
662 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
664 VM_BUG_ON(migratetype
== -1);
665 if (is_migrate_isolate(migratetype
)) {
667 * We restrict max order of merging to prevent merge
668 * between freepages on isolate pageblock and normal
669 * pageblock. Without this, pageblock isolation
670 * could cause incorrect freepage accounting.
672 max_order
= min(MAX_ORDER
, pageblock_order
+ 1);
674 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
677 page_idx
= pfn
& ((1 << max_order
) - 1);
679 VM_BUG_ON_PAGE(page_idx
& ((1 << order
) - 1), page
);
680 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
682 while (order
< max_order
- 1) {
683 buddy_idx
= __find_buddy_index(page_idx
, order
);
684 buddy
= page
+ (buddy_idx
- page_idx
);
685 if (!page_is_buddy(page
, buddy
, order
))
688 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
689 * merge with it and move up one order.
691 if (page_is_guard(buddy
)) {
692 clear_page_guard(zone
, buddy
, order
, migratetype
);
694 list_del(&buddy
->lru
);
695 zone
->free_area
[order
].nr_free
--;
696 rmv_page_order(buddy
);
698 combined_idx
= buddy_idx
& page_idx
;
699 page
= page
+ (combined_idx
- page_idx
);
700 page_idx
= combined_idx
;
703 set_page_order(page
, order
);
706 * If this is not the largest possible page, check if the buddy
707 * of the next-highest order is free. If it is, it's possible
708 * that pages are being freed that will coalesce soon. In case,
709 * that is happening, add the free page to the tail of the list
710 * so it's less likely to be used soon and more likely to be merged
711 * as a higher order page
713 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
714 struct page
*higher_page
, *higher_buddy
;
715 combined_idx
= buddy_idx
& page_idx
;
716 higher_page
= page
+ (combined_idx
- page_idx
);
717 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
718 higher_buddy
= higher_page
+ (buddy_idx
- combined_idx
);
719 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
720 list_add_tail(&page
->lru
,
721 &zone
->free_area
[order
].free_list
[migratetype
]);
726 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
728 zone
->free_area
[order
].nr_free
++;
731 static inline int free_pages_check(struct page
*page
)
733 const char *bad_reason
= NULL
;
734 unsigned long bad_flags
= 0;
736 if (unlikely(page_mapcount(page
)))
737 bad_reason
= "nonzero mapcount";
738 if (unlikely(page
->mapping
!= NULL
))
739 bad_reason
= "non-NULL mapping";
740 if (unlikely(atomic_read(&page
->_count
) != 0))
741 bad_reason
= "nonzero _count";
742 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
743 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
744 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
747 if (unlikely(page
->mem_cgroup
))
748 bad_reason
= "page still charged to cgroup";
750 if (unlikely(bad_reason
)) {
751 bad_page(page
, bad_reason
, bad_flags
);
754 page_cpupid_reset_last(page
);
755 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
756 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
761 * Frees a number of pages from the PCP lists
762 * Assumes all pages on list are in same zone, and of same order.
763 * count is the number of pages to free.
765 * If the zone was previously in an "all pages pinned" state then look to
766 * see if this freeing clears that state.
768 * And clear the zone's pages_scanned counter, to hold off the "all pages are
769 * pinned" detection logic.
771 static void free_pcppages_bulk(struct zone
*zone
, int count
,
772 struct per_cpu_pages
*pcp
)
777 unsigned long nr_scanned
;
779 spin_lock(&zone
->lock
);
780 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
782 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
786 struct list_head
*list
;
789 * Remove pages from lists in a round-robin fashion. A
790 * batch_free count is maintained that is incremented when an
791 * empty list is encountered. This is so more pages are freed
792 * off fuller lists instead of spinning excessively around empty
797 if (++migratetype
== MIGRATE_PCPTYPES
)
799 list
= &pcp
->lists
[migratetype
];
800 } while (list_empty(list
));
802 /* This is the only non-empty list. Free them all. */
803 if (batch_free
== MIGRATE_PCPTYPES
)
804 batch_free
= to_free
;
807 int mt
; /* migratetype of the to-be-freed page */
809 page
= list_entry(list
->prev
, struct page
, lru
);
810 /* must delete as __free_one_page list manipulates */
811 list_del(&page
->lru
);
813 mt
= get_pcppage_migratetype(page
);
814 /* MIGRATE_ISOLATE page should not go to pcplists */
815 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
816 /* Pageblock could have been isolated meanwhile */
817 if (unlikely(has_isolate_pageblock(zone
)))
818 mt
= get_pageblock_migratetype(page
);
820 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
821 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
);
822 trace_mm_page_pcpu_drain(page
, 0, mt
);
823 } while (--to_free
&& --batch_free
&& !list_empty(list
));
825 spin_unlock(&zone
->lock
);
828 static void free_one_page(struct zone
*zone
,
829 struct page
*page
, unsigned long pfn
,
833 unsigned long nr_scanned
;
834 spin_lock(&zone
->lock
);
835 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
837 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
839 if (unlikely(has_isolate_pageblock(zone
) ||
840 is_migrate_isolate(migratetype
))) {
841 migratetype
= get_pfnblock_migratetype(page
, pfn
);
843 __free_one_page(page
, pfn
, zone
, order
, migratetype
);
844 spin_unlock(&zone
->lock
);
847 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
849 if (!IS_ENABLED(CONFIG_DEBUG_VM
))
851 if (unlikely(!PageTail(page
))) {
852 bad_page(page
, "PageTail not set", 0);
855 if (unlikely(page
->first_page
!= head_page
)) {
856 bad_page(page
, "first_page not consistent", 0);
862 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
863 unsigned long zone
, int nid
)
865 set_page_links(page
, zone
, nid
, pfn
);
866 init_page_count(page
);
867 page_mapcount_reset(page
);
868 page_cpupid_reset_last(page
);
870 INIT_LIST_HEAD(&page
->lru
);
871 #ifdef WANT_PAGE_VIRTUAL
872 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
873 if (!is_highmem_idx(zone
))
874 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
878 static void __meminit
__init_single_pfn(unsigned long pfn
, unsigned long zone
,
881 return __init_single_page(pfn_to_page(pfn
), pfn
, zone
, nid
);
884 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
885 static void init_reserved_page(unsigned long pfn
)
890 if (!early_page_uninitialised(pfn
))
893 nid
= early_pfn_to_nid(pfn
);
894 pgdat
= NODE_DATA(nid
);
896 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
897 struct zone
*zone
= &pgdat
->node_zones
[zid
];
899 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
902 __init_single_pfn(pfn
, zid
, nid
);
905 static inline void init_reserved_page(unsigned long pfn
)
908 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
911 * Initialised pages do not have PageReserved set. This function is
912 * called for each range allocated by the bootmem allocator and
913 * marks the pages PageReserved. The remaining valid pages are later
914 * sent to the buddy page allocator.
916 void __meminit
reserve_bootmem_region(unsigned long start
, unsigned long end
)
918 unsigned long start_pfn
= PFN_DOWN(start
);
919 unsigned long end_pfn
= PFN_UP(end
);
921 for (; start_pfn
< end_pfn
; start_pfn
++) {
922 if (pfn_valid(start_pfn
)) {
923 struct page
*page
= pfn_to_page(start_pfn
);
925 init_reserved_page(start_pfn
);
926 SetPageReserved(page
);
931 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
933 bool compound
= PageCompound(page
);
936 VM_BUG_ON_PAGE(PageTail(page
), page
);
937 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
939 trace_mm_page_free(page
, order
);
940 kmemcheck_free_shadow(page
, order
);
941 kasan_free_pages(page
, order
);
944 page
->mapping
= NULL
;
945 bad
+= free_pages_check(page
);
946 for (i
= 1; i
< (1 << order
); i
++) {
948 bad
+= free_tail_pages_check(page
, page
+ i
);
949 bad
+= free_pages_check(page
+ i
);
954 reset_page_owner(page
, order
);
956 if (!PageHighMem(page
)) {
957 debug_check_no_locks_freed(page_address(page
),
959 debug_check_no_obj_freed(page_address(page
),
962 arch_free_page(page
, order
);
963 kernel_map_pages(page
, 1 << order
, 0);
968 static void __free_pages_ok(struct page
*page
, unsigned int order
)
972 unsigned long pfn
= page_to_pfn(page
);
974 if (!free_pages_prepare(page
, order
))
977 migratetype
= get_pfnblock_migratetype(page
, pfn
);
978 local_irq_save(flags
);
979 __count_vm_events(PGFREE
, 1 << order
);
980 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
981 local_irq_restore(flags
);
984 static void __init
__free_pages_boot_core(struct page
*page
,
985 unsigned long pfn
, unsigned int order
)
987 unsigned int nr_pages
= 1 << order
;
988 struct page
*p
= page
;
992 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
994 __ClearPageReserved(p
);
995 set_page_count(p
, 0);
997 __ClearPageReserved(p
);
998 set_page_count(p
, 0);
1000 page_zone(page
)->managed_pages
+= nr_pages
;
1001 set_page_refcounted(page
);
1002 __free_pages(page
, order
);
1005 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1006 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1008 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1010 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1012 static DEFINE_SPINLOCK(early_pfn_lock
);
1015 spin_lock(&early_pfn_lock
);
1016 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1019 spin_unlock(&early_pfn_lock
);
1025 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1026 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1027 struct mminit_pfnnid_cache
*state
)
1031 nid
= __early_pfn_to_nid(pfn
, state
);
1032 if (nid
>= 0 && nid
!= node
)
1037 /* Only safe to use early in boot when initialisation is single-threaded */
1038 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1040 return meminit_pfn_in_nid(pfn
, node
, &early_pfnnid_cache
);
1045 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1049 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1050 struct mminit_pfnnid_cache
*state
)
1057 void __init
__free_pages_bootmem(struct page
*page
, unsigned long pfn
,
1060 if (early_page_uninitialised(pfn
))
1062 return __free_pages_boot_core(page
, pfn
, order
);
1065 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1066 static void __init
deferred_free_range(struct page
*page
,
1067 unsigned long pfn
, int nr_pages
)
1074 /* Free a large naturally-aligned chunk if possible */
1075 if (nr_pages
== MAX_ORDER_NR_PAGES
&&
1076 (pfn
& (MAX_ORDER_NR_PAGES
-1)) == 0) {
1077 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1078 __free_pages_boot_core(page
, pfn
, MAX_ORDER
-1);
1082 for (i
= 0; i
< nr_pages
; i
++, page
++, pfn
++)
1083 __free_pages_boot_core(page
, pfn
, 0);
1086 /* Completion tracking for deferred_init_memmap() threads */
1087 static atomic_t pgdat_init_n_undone __initdata
;
1088 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1090 static inline void __init
pgdat_init_report_one_done(void)
1092 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1093 complete(&pgdat_init_all_done_comp
);
1096 /* Initialise remaining memory on a node */
1097 static int __init
deferred_init_memmap(void *data
)
1099 pg_data_t
*pgdat
= data
;
1100 int nid
= pgdat
->node_id
;
1101 struct mminit_pfnnid_cache nid_init_state
= { };
1102 unsigned long start
= jiffies
;
1103 unsigned long nr_pages
= 0;
1104 unsigned long walk_start
, walk_end
;
1107 unsigned long first_init_pfn
= pgdat
->first_deferred_pfn
;
1108 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1110 if (first_init_pfn
== ULONG_MAX
) {
1111 pgdat_init_report_one_done();
1115 /* Bind memory initialisation thread to a local node if possible */
1116 if (!cpumask_empty(cpumask
))
1117 set_cpus_allowed_ptr(current
, cpumask
);
1119 /* Sanity check boundaries */
1120 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1121 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1122 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1124 /* Only the highest zone is deferred so find it */
1125 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1126 zone
= pgdat
->node_zones
+ zid
;
1127 if (first_init_pfn
< zone_end_pfn(zone
))
1131 for_each_mem_pfn_range(i
, nid
, &walk_start
, &walk_end
, NULL
) {
1132 unsigned long pfn
, end_pfn
;
1133 struct page
*page
= NULL
;
1134 struct page
*free_base_page
= NULL
;
1135 unsigned long free_base_pfn
= 0;
1138 end_pfn
= min(walk_end
, zone_end_pfn(zone
));
1139 pfn
= first_init_pfn
;
1140 if (pfn
< walk_start
)
1142 if (pfn
< zone
->zone_start_pfn
)
1143 pfn
= zone
->zone_start_pfn
;
1145 for (; pfn
< end_pfn
; pfn
++) {
1146 if (!pfn_valid_within(pfn
))
1150 * Ensure pfn_valid is checked every
1151 * MAX_ORDER_NR_PAGES for memory holes
1153 if ((pfn
& (MAX_ORDER_NR_PAGES
- 1)) == 0) {
1154 if (!pfn_valid(pfn
)) {
1160 if (!meminit_pfn_in_nid(pfn
, nid
, &nid_init_state
)) {
1165 /* Minimise pfn page lookups and scheduler checks */
1166 if (page
&& (pfn
& (MAX_ORDER_NR_PAGES
- 1)) != 0) {
1169 nr_pages
+= nr_to_free
;
1170 deferred_free_range(free_base_page
,
1171 free_base_pfn
, nr_to_free
);
1172 free_base_page
= NULL
;
1173 free_base_pfn
= nr_to_free
= 0;
1175 page
= pfn_to_page(pfn
);
1180 VM_BUG_ON(page_zone(page
) != zone
);
1184 __init_single_page(page
, pfn
, zid
, nid
);
1185 if (!free_base_page
) {
1186 free_base_page
= page
;
1187 free_base_pfn
= pfn
;
1192 /* Where possible, batch up pages for a single free */
1195 /* Free the current block of pages to allocator */
1196 nr_pages
+= nr_to_free
;
1197 deferred_free_range(free_base_page
, free_base_pfn
,
1199 free_base_page
= NULL
;
1200 free_base_pfn
= nr_to_free
= 0;
1203 first_init_pfn
= max(end_pfn
, first_init_pfn
);
1206 /* Sanity check that the next zone really is unpopulated */
1207 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1209 pr_info("node %d initialised, %lu pages in %ums\n", nid
, nr_pages
,
1210 jiffies_to_msecs(jiffies
- start
));
1212 pgdat_init_report_one_done();
1216 void __init
page_alloc_init_late(void)
1220 /* There will be num_node_state(N_MEMORY) threads */
1221 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
1222 for_each_node_state(nid
, N_MEMORY
) {
1223 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
1226 /* Block until all are initialised */
1227 wait_for_completion(&pgdat_init_all_done_comp
);
1229 /* Reinit limits that are based on free pages after the kernel is up */
1230 files_maxfiles_init();
1232 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1235 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1236 void __init
init_cma_reserved_pageblock(struct page
*page
)
1238 unsigned i
= pageblock_nr_pages
;
1239 struct page
*p
= page
;
1242 __ClearPageReserved(p
);
1243 set_page_count(p
, 0);
1246 set_pageblock_migratetype(page
, MIGRATE_CMA
);
1248 if (pageblock_order
>= MAX_ORDER
) {
1249 i
= pageblock_nr_pages
;
1252 set_page_refcounted(p
);
1253 __free_pages(p
, MAX_ORDER
- 1);
1254 p
+= MAX_ORDER_NR_PAGES
;
1255 } while (i
-= MAX_ORDER_NR_PAGES
);
1257 set_page_refcounted(page
);
1258 __free_pages(page
, pageblock_order
);
1261 adjust_managed_page_count(page
, pageblock_nr_pages
);
1266 * The order of subdivision here is critical for the IO subsystem.
1267 * Please do not alter this order without good reasons and regression
1268 * testing. Specifically, as large blocks of memory are subdivided,
1269 * the order in which smaller blocks are delivered depends on the order
1270 * they're subdivided in this function. This is the primary factor
1271 * influencing the order in which pages are delivered to the IO
1272 * subsystem according to empirical testing, and this is also justified
1273 * by considering the behavior of a buddy system containing a single
1274 * large block of memory acted on by a series of small allocations.
1275 * This behavior is a critical factor in sglist merging's success.
1279 static inline void expand(struct zone
*zone
, struct page
*page
,
1280 int low
, int high
, struct free_area
*area
,
1283 unsigned long size
= 1 << high
;
1285 while (high
> low
) {
1289 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
1291 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC
) &&
1292 debug_guardpage_enabled() &&
1293 high
< debug_guardpage_minorder()) {
1295 * Mark as guard pages (or page), that will allow to
1296 * merge back to allocator when buddy will be freed.
1297 * Corresponding page table entries will not be touched,
1298 * pages will stay not present in virtual address space
1300 set_page_guard(zone
, &page
[size
], high
, migratetype
);
1303 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
1305 set_page_order(&page
[size
], high
);
1310 * This page is about to be returned from the page allocator
1312 static inline int check_new_page(struct page
*page
)
1314 const char *bad_reason
= NULL
;
1315 unsigned long bad_flags
= 0;
1317 if (unlikely(page_mapcount(page
)))
1318 bad_reason
= "nonzero mapcount";
1319 if (unlikely(page
->mapping
!= NULL
))
1320 bad_reason
= "non-NULL mapping";
1321 if (unlikely(atomic_read(&page
->_count
) != 0))
1322 bad_reason
= "nonzero _count";
1323 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
1324 bad_reason
= "HWPoisoned (hardware-corrupted)";
1325 bad_flags
= __PG_HWPOISON
;
1327 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
1328 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
1329 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
1332 if (unlikely(page
->mem_cgroup
))
1333 bad_reason
= "page still charged to cgroup";
1335 if (unlikely(bad_reason
)) {
1336 bad_page(page
, bad_reason
, bad_flags
);
1342 static int prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
1347 for (i
= 0; i
< (1 << order
); i
++) {
1348 struct page
*p
= page
+ i
;
1349 if (unlikely(check_new_page(p
)))
1353 set_page_private(page
, 0);
1354 set_page_refcounted(page
);
1356 arch_alloc_page(page
, order
);
1357 kernel_map_pages(page
, 1 << order
, 1);
1358 kasan_alloc_pages(page
, order
);
1360 if (gfp_flags
& __GFP_ZERO
)
1361 for (i
= 0; i
< (1 << order
); i
++)
1362 clear_highpage(page
+ i
);
1364 if (order
&& (gfp_flags
& __GFP_COMP
))
1365 prep_compound_page(page
, order
);
1367 set_page_owner(page
, order
, gfp_flags
);
1370 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1371 * allocate the page. The expectation is that the caller is taking
1372 * steps that will free more memory. The caller should avoid the page
1373 * being used for !PFMEMALLOC purposes.
1375 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
1376 set_page_pfmemalloc(page
);
1378 clear_page_pfmemalloc(page
);
1384 * Go through the free lists for the given migratetype and remove
1385 * the smallest available page from the freelists
1388 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
1391 unsigned int current_order
;
1392 struct free_area
*area
;
1395 /* Find a page of the appropriate size in the preferred list */
1396 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
1397 area
= &(zone
->free_area
[current_order
]);
1398 if (list_empty(&area
->free_list
[migratetype
]))
1401 page
= list_entry(area
->free_list
[migratetype
].next
,
1403 list_del(&page
->lru
);
1404 rmv_page_order(page
);
1406 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1407 set_pcppage_migratetype(page
, migratetype
);
1416 * This array describes the order lists are fallen back to when
1417 * the free lists for the desirable migrate type are depleted
1419 static int fallbacks
[MIGRATE_TYPES
][4] = {
1420 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
1421 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_RESERVE
},
1422 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_RESERVE
},
1424 [MIGRATE_CMA
] = { MIGRATE_RESERVE
}, /* Never used */
1426 [MIGRATE_RESERVE
] = { MIGRATE_RESERVE
}, /* Never used */
1427 #ifdef CONFIG_MEMORY_ISOLATION
1428 [MIGRATE_ISOLATE
] = { MIGRATE_RESERVE
}, /* Never used */
1433 static struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1436 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
1439 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1440 unsigned int order
) { return NULL
; }
1444 * Move the free pages in a range to the free lists of the requested type.
1445 * Note that start_page and end_pages are not aligned on a pageblock
1446 * boundary. If alignment is required, use move_freepages_block()
1448 int move_freepages(struct zone
*zone
,
1449 struct page
*start_page
, struct page
*end_page
,
1453 unsigned long order
;
1454 int pages_moved
= 0;
1456 #ifndef CONFIG_HOLES_IN_ZONE
1458 * page_zone is not safe to call in this context when
1459 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1460 * anyway as we check zone boundaries in move_freepages_block().
1461 * Remove at a later date when no bug reports exist related to
1462 * grouping pages by mobility
1464 VM_BUG_ON(page_zone(start_page
) != page_zone(end_page
));
1467 for (page
= start_page
; page
<= end_page
;) {
1468 /* Make sure we are not inadvertently changing nodes */
1469 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
1471 if (!pfn_valid_within(page_to_pfn(page
))) {
1476 if (!PageBuddy(page
)) {
1481 order
= page_order(page
);
1482 list_move(&page
->lru
,
1483 &zone
->free_area
[order
].free_list
[migratetype
]);
1485 pages_moved
+= 1 << order
;
1491 int move_freepages_block(struct zone
*zone
, struct page
*page
,
1494 unsigned long start_pfn
, end_pfn
;
1495 struct page
*start_page
, *end_page
;
1497 start_pfn
= page_to_pfn(page
);
1498 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
1499 start_page
= pfn_to_page(start_pfn
);
1500 end_page
= start_page
+ pageblock_nr_pages
- 1;
1501 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
1503 /* Do not cross zone boundaries */
1504 if (!zone_spans_pfn(zone
, start_pfn
))
1506 if (!zone_spans_pfn(zone
, end_pfn
))
1509 return move_freepages(zone
, start_page
, end_page
, migratetype
);
1512 static void change_pageblock_range(struct page
*pageblock_page
,
1513 int start_order
, int migratetype
)
1515 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1517 while (nr_pageblocks
--) {
1518 set_pageblock_migratetype(pageblock_page
, migratetype
);
1519 pageblock_page
+= pageblock_nr_pages
;
1524 * When we are falling back to another migratetype during allocation, try to
1525 * steal extra free pages from the same pageblocks to satisfy further
1526 * allocations, instead of polluting multiple pageblocks.
1528 * If we are stealing a relatively large buddy page, it is likely there will
1529 * be more free pages in the pageblock, so try to steal them all. For
1530 * reclaimable and unmovable allocations, we steal regardless of page size,
1531 * as fragmentation caused by those allocations polluting movable pageblocks
1532 * is worse than movable allocations stealing from unmovable and reclaimable
1535 static bool can_steal_fallback(unsigned int order
, int start_mt
)
1538 * Leaving this order check is intended, although there is
1539 * relaxed order check in next check. The reason is that
1540 * we can actually steal whole pageblock if this condition met,
1541 * but, below check doesn't guarantee it and that is just heuristic
1542 * so could be changed anytime.
1544 if (order
>= pageblock_order
)
1547 if (order
>= pageblock_order
/ 2 ||
1548 start_mt
== MIGRATE_RECLAIMABLE
||
1549 start_mt
== MIGRATE_UNMOVABLE
||
1550 page_group_by_mobility_disabled
)
1557 * This function implements actual steal behaviour. If order is large enough,
1558 * we can steal whole pageblock. If not, we first move freepages in this
1559 * pageblock and check whether half of pages are moved or not. If half of
1560 * pages are moved, we can change migratetype of pageblock and permanently
1561 * use it's pages as requested migratetype in the future.
1563 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
1566 int current_order
= page_order(page
);
1569 /* Take ownership for orders >= pageblock_order */
1570 if (current_order
>= pageblock_order
) {
1571 change_pageblock_range(page
, current_order
, start_type
);
1575 pages
= move_freepages_block(zone
, page
, start_type
);
1577 /* Claim the whole block if over half of it is free */
1578 if (pages
>= (1 << (pageblock_order
-1)) ||
1579 page_group_by_mobility_disabled
)
1580 set_pageblock_migratetype(page
, start_type
);
1584 * Check whether there is a suitable fallback freepage with requested order.
1585 * If only_stealable is true, this function returns fallback_mt only if
1586 * we can steal other freepages all together. This would help to reduce
1587 * fragmentation due to mixed migratetype pages in one pageblock.
1589 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
1590 int migratetype
, bool only_stealable
, bool *can_steal
)
1595 if (area
->nr_free
== 0)
1600 fallback_mt
= fallbacks
[migratetype
][i
];
1601 if (fallback_mt
== MIGRATE_RESERVE
)
1604 if (list_empty(&area
->free_list
[fallback_mt
]))
1607 if (can_steal_fallback(order
, migratetype
))
1610 if (!only_stealable
)
1620 /* Remove an element from the buddy allocator from the fallback list */
1621 static inline struct page
*
1622 __rmqueue_fallback(struct zone
*zone
, unsigned int order
, int start_migratetype
)
1624 struct free_area
*area
;
1625 unsigned int current_order
;
1630 /* Find the largest possible block of pages in the other list */
1631 for (current_order
= MAX_ORDER
-1;
1632 current_order
>= order
&& current_order
<= MAX_ORDER
-1;
1634 area
= &(zone
->free_area
[current_order
]);
1635 fallback_mt
= find_suitable_fallback(area
, current_order
,
1636 start_migratetype
, false, &can_steal
);
1637 if (fallback_mt
== -1)
1640 page
= list_entry(area
->free_list
[fallback_mt
].next
,
1643 steal_suitable_fallback(zone
, page
, start_migratetype
);
1645 /* Remove the page from the freelists */
1647 list_del(&page
->lru
);
1648 rmv_page_order(page
);
1650 expand(zone
, page
, order
, current_order
, area
,
1653 * The pcppage_migratetype may differ from pageblock's
1654 * migratetype depending on the decisions in
1655 * find_suitable_fallback(). This is OK as long as it does not
1656 * differ for MIGRATE_CMA pageblocks. Those can be used as
1657 * fallback only via special __rmqueue_cma_fallback() function
1659 set_pcppage_migratetype(page
, start_migratetype
);
1661 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
1662 start_migratetype
, fallback_mt
);
1671 * Do the hard work of removing an element from the buddy allocator.
1672 * Call me with the zone->lock already held.
1674 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
1680 page
= __rmqueue_smallest(zone
, order
, migratetype
);
1682 if (unlikely(!page
) && migratetype
!= MIGRATE_RESERVE
) {
1683 if (migratetype
== MIGRATE_MOVABLE
)
1684 page
= __rmqueue_cma_fallback(zone
, order
);
1687 page
= __rmqueue_fallback(zone
, order
, migratetype
);
1690 * Use MIGRATE_RESERVE rather than fail an allocation. goto
1691 * is used because __rmqueue_smallest is an inline function
1692 * and we want just one call site
1695 migratetype
= MIGRATE_RESERVE
;
1700 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1705 * Obtain a specified number of elements from the buddy allocator, all under
1706 * a single hold of the lock, for efficiency. Add them to the supplied list.
1707 * Returns the number of new pages which were placed at *list.
1709 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1710 unsigned long count
, struct list_head
*list
,
1711 int migratetype
, bool cold
)
1715 spin_lock(&zone
->lock
);
1716 for (i
= 0; i
< count
; ++i
) {
1717 struct page
*page
= __rmqueue(zone
, order
, migratetype
);
1718 if (unlikely(page
== NULL
))
1722 * Split buddy pages returned by expand() are received here
1723 * in physical page order. The page is added to the callers and
1724 * list and the list head then moves forward. From the callers
1725 * perspective, the linked list is ordered by page number in
1726 * some conditions. This is useful for IO devices that can
1727 * merge IO requests if the physical pages are ordered
1731 list_add(&page
->lru
, list
);
1733 list_add_tail(&page
->lru
, list
);
1735 if (is_migrate_cma(get_pcppage_migratetype(page
)))
1736 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
1739 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
1740 spin_unlock(&zone
->lock
);
1746 * Called from the vmstat counter updater to drain pagesets of this
1747 * currently executing processor on remote nodes after they have
1750 * Note that this function must be called with the thread pinned to
1751 * a single processor.
1753 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
1755 unsigned long flags
;
1756 int to_drain
, batch
;
1758 local_irq_save(flags
);
1759 batch
= READ_ONCE(pcp
->batch
);
1760 to_drain
= min(pcp
->count
, batch
);
1762 free_pcppages_bulk(zone
, to_drain
, pcp
);
1763 pcp
->count
-= to_drain
;
1765 local_irq_restore(flags
);
1770 * Drain pcplists of the indicated processor and zone.
1772 * The processor must either be the current processor and the
1773 * thread pinned to the current processor or a processor that
1776 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
1778 unsigned long flags
;
1779 struct per_cpu_pageset
*pset
;
1780 struct per_cpu_pages
*pcp
;
1782 local_irq_save(flags
);
1783 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
1787 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1790 local_irq_restore(flags
);
1794 * Drain pcplists of all zones on the indicated processor.
1796 * The processor must either be the current processor and the
1797 * thread pinned to the current processor or a processor that
1800 static void drain_pages(unsigned int cpu
)
1804 for_each_populated_zone(zone
) {
1805 drain_pages_zone(cpu
, zone
);
1810 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1812 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
1813 * the single zone's pages.
1815 void drain_local_pages(struct zone
*zone
)
1817 int cpu
= smp_processor_id();
1820 drain_pages_zone(cpu
, zone
);
1826 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
1828 * When zone parameter is non-NULL, spill just the single zone's pages.
1830 * Note that this code is protected against sending an IPI to an offline
1831 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
1832 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
1833 * nothing keeps CPUs from showing up after we populated the cpumask and
1834 * before the call to on_each_cpu_mask().
1836 void drain_all_pages(struct zone
*zone
)
1841 * Allocate in the BSS so we wont require allocation in
1842 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
1844 static cpumask_t cpus_with_pcps
;
1847 * We don't care about racing with CPU hotplug event
1848 * as offline notification will cause the notified
1849 * cpu to drain that CPU pcps and on_each_cpu_mask
1850 * disables preemption as part of its processing
1852 for_each_online_cpu(cpu
) {
1853 struct per_cpu_pageset
*pcp
;
1855 bool has_pcps
= false;
1858 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
1862 for_each_populated_zone(z
) {
1863 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
1864 if (pcp
->pcp
.count
) {
1872 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
1874 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
1876 on_each_cpu_mask(&cpus_with_pcps
, (smp_call_func_t
) drain_local_pages
,
1880 #ifdef CONFIG_HIBERNATION
1882 void mark_free_pages(struct zone
*zone
)
1884 unsigned long pfn
, max_zone_pfn
;
1885 unsigned long flags
;
1886 unsigned int order
, t
;
1887 struct list_head
*curr
;
1889 if (zone_is_empty(zone
))
1892 spin_lock_irqsave(&zone
->lock
, flags
);
1894 max_zone_pfn
= zone_end_pfn(zone
);
1895 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
1896 if (pfn_valid(pfn
)) {
1897 struct page
*page
= pfn_to_page(pfn
);
1899 if (!swsusp_page_is_forbidden(page
))
1900 swsusp_unset_page_free(page
);
1903 for_each_migratetype_order(order
, t
) {
1904 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
1907 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
1908 for (i
= 0; i
< (1UL << order
); i
++)
1909 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
1912 spin_unlock_irqrestore(&zone
->lock
, flags
);
1914 #endif /* CONFIG_PM */
1917 * Free a 0-order page
1918 * cold == true ? free a cold page : free a hot page
1920 void free_hot_cold_page(struct page
*page
, bool cold
)
1922 struct zone
*zone
= page_zone(page
);
1923 struct per_cpu_pages
*pcp
;
1924 unsigned long flags
;
1925 unsigned long pfn
= page_to_pfn(page
);
1928 if (!free_pages_prepare(page
, 0))
1931 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1932 set_pcppage_migratetype(page
, migratetype
);
1933 local_irq_save(flags
);
1934 __count_vm_event(PGFREE
);
1937 * We only track unmovable, reclaimable and movable on pcp lists.
1938 * Free ISOLATE pages back to the allocator because they are being
1939 * offlined but treat RESERVE as movable pages so we can get those
1940 * areas back if necessary. Otherwise, we may have to free
1941 * excessively into the page allocator
1943 if (migratetype
>= MIGRATE_PCPTYPES
) {
1944 if (unlikely(is_migrate_isolate(migratetype
))) {
1945 free_one_page(zone
, page
, pfn
, 0, migratetype
);
1948 migratetype
= MIGRATE_MOVABLE
;
1951 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
1953 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
1955 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
1957 if (pcp
->count
>= pcp
->high
) {
1958 unsigned long batch
= READ_ONCE(pcp
->batch
);
1959 free_pcppages_bulk(zone
, batch
, pcp
);
1960 pcp
->count
-= batch
;
1964 local_irq_restore(flags
);
1968 * Free a list of 0-order pages
1970 void free_hot_cold_page_list(struct list_head
*list
, bool cold
)
1972 struct page
*page
, *next
;
1974 list_for_each_entry_safe(page
, next
, list
, lru
) {
1975 trace_mm_page_free_batched(page
, cold
);
1976 free_hot_cold_page(page
, cold
);
1981 * split_page takes a non-compound higher-order page, and splits it into
1982 * n (1<<order) sub-pages: page[0..n]
1983 * Each sub-page must be freed individually.
1985 * Note: this is probably too low level an operation for use in drivers.
1986 * Please consult with lkml before using this in your driver.
1988 void split_page(struct page
*page
, unsigned int order
)
1993 VM_BUG_ON_PAGE(PageCompound(page
), page
);
1994 VM_BUG_ON_PAGE(!page_count(page
), page
);
1996 #ifdef CONFIG_KMEMCHECK
1998 * Split shadow pages too, because free(page[0]) would
1999 * otherwise free the whole shadow.
2001 if (kmemcheck_page_is_tracked(page
))
2002 split_page(virt_to_page(page
[0].shadow
), order
);
2005 gfp_mask
= get_page_owner_gfp(page
);
2006 set_page_owner(page
, 0, gfp_mask
);
2007 for (i
= 1; i
< (1 << order
); i
++) {
2008 set_page_refcounted(page
+ i
);
2009 set_page_owner(page
+ i
, 0, gfp_mask
);
2012 EXPORT_SYMBOL_GPL(split_page
);
2014 int __isolate_free_page(struct page
*page
, unsigned int order
)
2016 unsigned long watermark
;
2020 BUG_ON(!PageBuddy(page
));
2022 zone
= page_zone(page
);
2023 mt
= get_pageblock_migratetype(page
);
2025 if (!is_migrate_isolate(mt
)) {
2026 /* Obey watermarks as if the page was being allocated */
2027 watermark
= low_wmark_pages(zone
) + (1 << order
);
2028 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
2031 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
2034 /* Remove page from free list */
2035 list_del(&page
->lru
);
2036 zone
->free_area
[order
].nr_free
--;
2037 rmv_page_order(page
);
2039 set_page_owner(page
, order
, __GFP_MOVABLE
);
2041 /* Set the pageblock if the isolated page is at least a pageblock */
2042 if (order
>= pageblock_order
- 1) {
2043 struct page
*endpage
= page
+ (1 << order
) - 1;
2044 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
2045 int mt
= get_pageblock_migratetype(page
);
2046 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
))
2047 set_pageblock_migratetype(page
,
2053 return 1UL << order
;
2057 * Similar to split_page except the page is already free. As this is only
2058 * being used for migration, the migratetype of the block also changes.
2059 * As this is called with interrupts disabled, the caller is responsible
2060 * for calling arch_alloc_page() and kernel_map_page() after interrupts
2063 * Note: this is probably too low level an operation for use in drivers.
2064 * Please consult with lkml before using this in your driver.
2066 int split_free_page(struct page
*page
)
2071 order
= page_order(page
);
2073 nr_pages
= __isolate_free_page(page
, order
);
2077 /* Split into individual pages */
2078 set_page_refcounted(page
);
2079 split_page(page
, order
);
2084 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2087 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
2088 struct zone
*zone
, unsigned int order
,
2089 gfp_t gfp_flags
, int migratetype
)
2091 unsigned long flags
;
2093 bool cold
= ((gfp_flags
& __GFP_COLD
) != 0);
2095 if (likely(order
== 0)) {
2096 struct per_cpu_pages
*pcp
;
2097 struct list_head
*list
;
2099 local_irq_save(flags
);
2100 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2101 list
= &pcp
->lists
[migratetype
];
2102 if (list_empty(list
)) {
2103 pcp
->count
+= rmqueue_bulk(zone
, 0,
2106 if (unlikely(list_empty(list
)))
2111 page
= list_entry(list
->prev
, struct page
, lru
);
2113 page
= list_entry(list
->next
, struct page
, lru
);
2115 list_del(&page
->lru
);
2118 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
2120 * __GFP_NOFAIL is not to be used in new code.
2122 * All __GFP_NOFAIL callers should be fixed so that they
2123 * properly detect and handle allocation failures.
2125 * We most definitely don't want callers attempting to
2126 * allocate greater than order-1 page units with
2129 WARN_ON_ONCE(order
> 1);
2131 spin_lock_irqsave(&zone
->lock
, flags
);
2132 page
= __rmqueue(zone
, order
, migratetype
);
2133 spin_unlock(&zone
->lock
);
2136 __mod_zone_freepage_state(zone
, -(1 << order
),
2137 get_pcppage_migratetype(page
));
2140 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
, -(1 << order
));
2141 if (atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]) <= 0 &&
2142 !test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
))
2143 set_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2145 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
2146 zone_statistics(preferred_zone
, zone
, gfp_flags
);
2147 local_irq_restore(flags
);
2149 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
2153 local_irq_restore(flags
);
2157 #ifdef CONFIG_FAIL_PAGE_ALLOC
2160 struct fault_attr attr
;
2162 bool ignore_gfp_highmem
;
2163 bool ignore_gfp_wait
;
2165 } fail_page_alloc
= {
2166 .attr
= FAULT_ATTR_INITIALIZER
,
2167 .ignore_gfp_wait
= true,
2168 .ignore_gfp_highmem
= true,
2172 static int __init
setup_fail_page_alloc(char *str
)
2174 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
2176 __setup("fail_page_alloc=", setup_fail_page_alloc
);
2178 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2180 if (order
< fail_page_alloc
.min_order
)
2182 if (gfp_mask
& __GFP_NOFAIL
)
2184 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
2186 if (fail_page_alloc
.ignore_gfp_wait
&& (gfp_mask
& __GFP_WAIT
))
2189 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
2192 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2194 static int __init
fail_page_alloc_debugfs(void)
2196 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
2199 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
2200 &fail_page_alloc
.attr
);
2202 return PTR_ERR(dir
);
2204 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
2205 &fail_page_alloc
.ignore_gfp_wait
))
2207 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
2208 &fail_page_alloc
.ignore_gfp_highmem
))
2210 if (!debugfs_create_u32("min-order", mode
, dir
,
2211 &fail_page_alloc
.min_order
))
2216 debugfs_remove_recursive(dir
);
2221 late_initcall(fail_page_alloc_debugfs
);
2223 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2225 #else /* CONFIG_FAIL_PAGE_ALLOC */
2227 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2232 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2235 * Return true if free pages are above 'mark'. This takes into account the order
2236 * of the allocation.
2238 static bool __zone_watermark_ok(struct zone
*z
, unsigned int order
,
2239 unsigned long mark
, int classzone_idx
, int alloc_flags
,
2242 /* free_pages may go negative - that's OK */
2247 free_pages
-= (1 << order
) - 1;
2248 if (alloc_flags
& ALLOC_HIGH
)
2250 if (alloc_flags
& ALLOC_HARDER
)
2254 /* If allocation can't use CMA areas don't use free CMA pages */
2255 if (!(alloc_flags
& ALLOC_CMA
))
2256 free_cma
= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2259 if (free_pages
- free_cma
<= min
+ z
->lowmem_reserve
[classzone_idx
])
2261 for (o
= 0; o
< order
; o
++) {
2262 /* At the next order, this order's pages become unavailable */
2263 free_pages
-= z
->free_area
[o
].nr_free
<< o
;
2265 /* Require fewer higher order pages to be free */
2268 if (free_pages
<= min
)
2274 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2275 int classzone_idx
, int alloc_flags
)
2277 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
2278 zone_page_state(z
, NR_FREE_PAGES
));
2281 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
2282 unsigned long mark
, int classzone_idx
)
2284 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
2286 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
2287 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
2289 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, 0,
2295 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to
2296 * skip over zones that are not allowed by the cpuset, or that have
2297 * been recently (in last second) found to be nearly full. See further
2298 * comments in mmzone.h. Reduces cache footprint of zonelist scans
2299 * that have to skip over a lot of full or unallowed zones.
2301 * If the zonelist cache is present in the passed zonelist, then
2302 * returns a pointer to the allowed node mask (either the current
2303 * tasks mems_allowed, or node_states[N_MEMORY].)
2305 * If the zonelist cache is not available for this zonelist, does
2306 * nothing and returns NULL.
2308 * If the fullzones BITMAP in the zonelist cache is stale (more than
2309 * a second since last zap'd) then we zap it out (clear its bits.)
2311 * We hold off even calling zlc_setup, until after we've checked the
2312 * first zone in the zonelist, on the theory that most allocations will
2313 * be satisfied from that first zone, so best to examine that zone as
2314 * quickly as we can.
2316 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
2318 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
2319 nodemask_t
*allowednodes
; /* zonelist_cache approximation */
2321 zlc
= zonelist
->zlcache_ptr
;
2325 if (time_after(jiffies
, zlc
->last_full_zap
+ HZ
)) {
2326 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
2327 zlc
->last_full_zap
= jiffies
;
2330 allowednodes
= !in_interrupt() && (alloc_flags
& ALLOC_CPUSET
) ?
2331 &cpuset_current_mems_allowed
:
2332 &node_states
[N_MEMORY
];
2333 return allowednodes
;
2337 * Given 'z' scanning a zonelist, run a couple of quick checks to see
2338 * if it is worth looking at further for free memory:
2339 * 1) Check that the zone isn't thought to be full (doesn't have its
2340 * bit set in the zonelist_cache fullzones BITMAP).
2341 * 2) Check that the zones node (obtained from the zonelist_cache
2342 * z_to_n[] mapping) is allowed in the passed in allowednodes mask.
2343 * Return true (non-zero) if zone is worth looking at further, or
2344 * else return false (zero) if it is not.
2346 * This check -ignores- the distinction between various watermarks,
2347 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
2348 * found to be full for any variation of these watermarks, it will
2349 * be considered full for up to one second by all requests, unless
2350 * we are so low on memory on all allowed nodes that we are forced
2351 * into the second scan of the zonelist.
2353 * In the second scan we ignore this zonelist cache and exactly
2354 * apply the watermarks to all zones, even it is slower to do so.
2355 * We are low on memory in the second scan, and should leave no stone
2356 * unturned looking for a free page.
2358 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
2359 nodemask_t
*allowednodes
)
2361 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
2362 int i
; /* index of *z in zonelist zones */
2363 int n
; /* node that zone *z is on */
2365 zlc
= zonelist
->zlcache_ptr
;
2369 i
= z
- zonelist
->_zonerefs
;
2372 /* This zone is worth trying if it is allowed but not full */
2373 return node_isset(n
, *allowednodes
) && !test_bit(i
, zlc
->fullzones
);
2377 * Given 'z' scanning a zonelist, set the corresponding bit in
2378 * zlc->fullzones, so that subsequent attempts to allocate a page
2379 * from that zone don't waste time re-examining it.
2381 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
2383 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
2384 int i
; /* index of *z in zonelist zones */
2386 zlc
= zonelist
->zlcache_ptr
;
2390 i
= z
- zonelist
->_zonerefs
;
2392 set_bit(i
, zlc
->fullzones
);
2396 * clear all zones full, called after direct reclaim makes progress so that
2397 * a zone that was recently full is not skipped over for up to a second
2399 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
2401 struct zonelist_cache
*zlc
; /* cached zonelist speedup info */
2403 zlc
= zonelist
->zlcache_ptr
;
2407 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
2410 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2412 return local_zone
->node
== zone
->node
;
2415 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2417 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <
2421 #else /* CONFIG_NUMA */
2423 static nodemask_t
*zlc_setup(struct zonelist
*zonelist
, int alloc_flags
)
2428 static int zlc_zone_worth_trying(struct zonelist
*zonelist
, struct zoneref
*z
,
2429 nodemask_t
*allowednodes
)
2434 static void zlc_mark_zone_full(struct zonelist
*zonelist
, struct zoneref
*z
)
2438 static void zlc_clear_zones_full(struct zonelist
*zonelist
)
2442 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2447 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2452 #endif /* CONFIG_NUMA */
2454 static void reset_alloc_batches(struct zone
*preferred_zone
)
2456 struct zone
*zone
= preferred_zone
->zone_pgdat
->node_zones
;
2459 mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
2460 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
2461 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
2462 clear_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2463 } while (zone
++ != preferred_zone
);
2467 * get_page_from_freelist goes through the zonelist trying to allocate
2470 static struct page
*
2471 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
2472 const struct alloc_context
*ac
)
2474 struct zonelist
*zonelist
= ac
->zonelist
;
2476 struct page
*page
= NULL
;
2478 nodemask_t
*allowednodes
= NULL
;/* zonelist_cache approximation */
2479 int zlc_active
= 0; /* set if using zonelist_cache */
2480 int did_zlc_setup
= 0; /* just call zlc_setup() one time */
2481 int nr_fair_skipped
= 0;
2482 bool zonelist_rescan
;
2485 zonelist_rescan
= false;
2488 * Scan zonelist, looking for a zone with enough free.
2489 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2491 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
2495 if (IS_ENABLED(CONFIG_NUMA
) && zlc_active
&&
2496 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
2498 if (cpusets_enabled() &&
2499 (alloc_flags
& ALLOC_CPUSET
) &&
2500 !cpuset_zone_allowed(zone
, gfp_mask
))
2503 * Distribute pages in proportion to the individual
2504 * zone size to ensure fair page aging. The zone a
2505 * page was allocated in should have no effect on the
2506 * time the page has in memory before being reclaimed.
2508 if (alloc_flags
& ALLOC_FAIR
) {
2509 if (!zone_local(ac
->preferred_zone
, zone
))
2511 if (test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
)) {
2517 * When allocating a page cache page for writing, we
2518 * want to get it from a zone that is within its dirty
2519 * limit, such that no single zone holds more than its
2520 * proportional share of globally allowed dirty pages.
2521 * The dirty limits take into account the zone's
2522 * lowmem reserves and high watermark so that kswapd
2523 * should be able to balance it without having to
2524 * write pages from its LRU list.
2526 * This may look like it could increase pressure on
2527 * lower zones by failing allocations in higher zones
2528 * before they are full. But the pages that do spill
2529 * over are limited as the lower zones are protected
2530 * by this very same mechanism. It should not become
2531 * a practical burden to them.
2533 * XXX: For now, allow allocations to potentially
2534 * exceed the per-zone dirty limit in the slowpath
2535 * (spread_dirty_pages unset) before going into reclaim,
2536 * which is important when on a NUMA setup the allowed
2537 * zones are together not big enough to reach the
2538 * global limit. The proper fix for these situations
2539 * will require awareness of zones in the
2540 * dirty-throttling and the flusher threads.
2542 if (ac
->spread_dirty_pages
&& !zone_dirty_ok(zone
))
2545 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
2546 if (!zone_watermark_ok(zone
, order
, mark
,
2547 ac
->classzone_idx
, alloc_flags
)) {
2550 /* Checked here to keep the fast path fast */
2551 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
2552 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
2555 if (IS_ENABLED(CONFIG_NUMA
) &&
2556 !did_zlc_setup
&& nr_online_nodes
> 1) {
2558 * we do zlc_setup if there are multiple nodes
2559 * and before considering the first zone allowed
2562 allowednodes
= zlc_setup(zonelist
, alloc_flags
);
2567 if (zone_reclaim_mode
== 0 ||
2568 !zone_allows_reclaim(ac
->preferred_zone
, zone
))
2569 goto this_zone_full
;
2572 * As we may have just activated ZLC, check if the first
2573 * eligible zone has failed zone_reclaim recently.
2575 if (IS_ENABLED(CONFIG_NUMA
) && zlc_active
&&
2576 !zlc_zone_worth_trying(zonelist
, z
, allowednodes
))
2579 ret
= zone_reclaim(zone
, gfp_mask
, order
);
2581 case ZONE_RECLAIM_NOSCAN
:
2584 case ZONE_RECLAIM_FULL
:
2585 /* scanned but unreclaimable */
2588 /* did we reclaim enough */
2589 if (zone_watermark_ok(zone
, order
, mark
,
2590 ac
->classzone_idx
, alloc_flags
))
2594 * Failed to reclaim enough to meet watermark.
2595 * Only mark the zone full if checking the min
2596 * watermark or if we failed to reclaim just
2597 * 1<<order pages or else the page allocator
2598 * fastpath will prematurely mark zones full
2599 * when the watermark is between the low and
2602 if (((alloc_flags
& ALLOC_WMARK_MASK
) == ALLOC_WMARK_MIN
) ||
2603 ret
== ZONE_RECLAIM_SOME
)
2604 goto this_zone_full
;
2611 page
= buffered_rmqueue(ac
->preferred_zone
, zone
, order
,
2612 gfp_mask
, ac
->migratetype
);
2614 if (prep_new_page(page
, order
, gfp_mask
, alloc_flags
))
2619 if (IS_ENABLED(CONFIG_NUMA
) && zlc_active
)
2620 zlc_mark_zone_full(zonelist
, z
);
2624 * The first pass makes sure allocations are spread fairly within the
2625 * local node. However, the local node might have free pages left
2626 * after the fairness batches are exhausted, and remote zones haven't
2627 * even been considered yet. Try once more without fairness, and
2628 * include remote zones now, before entering the slowpath and waking
2629 * kswapd: prefer spilling to a remote zone over swapping locally.
2631 if (alloc_flags
& ALLOC_FAIR
) {
2632 alloc_flags
&= ~ALLOC_FAIR
;
2633 if (nr_fair_skipped
) {
2634 zonelist_rescan
= true;
2635 reset_alloc_batches(ac
->preferred_zone
);
2637 if (nr_online_nodes
> 1)
2638 zonelist_rescan
= true;
2641 if (unlikely(IS_ENABLED(CONFIG_NUMA
) && zlc_active
)) {
2642 /* Disable zlc cache for second zonelist scan */
2644 zonelist_rescan
= true;
2647 if (zonelist_rescan
)
2654 * Large machines with many possible nodes should not always dump per-node
2655 * meminfo in irq context.
2657 static inline bool should_suppress_show_mem(void)
2662 ret
= in_interrupt();
2667 static DEFINE_RATELIMIT_STATE(nopage_rs
,
2668 DEFAULT_RATELIMIT_INTERVAL
,
2669 DEFAULT_RATELIMIT_BURST
);
2671 void warn_alloc_failed(gfp_t gfp_mask
, int order
, const char *fmt
, ...)
2673 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
2675 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
2676 debug_guardpage_minorder() > 0)
2680 * This documents exceptions given to allocations in certain
2681 * contexts that are allowed to allocate outside current's set
2684 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2685 if (test_thread_flag(TIF_MEMDIE
) ||
2686 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
2687 filter
&= ~SHOW_MEM_FILTER_NODES
;
2688 if (in_interrupt() || !(gfp_mask
& __GFP_WAIT
))
2689 filter
&= ~SHOW_MEM_FILTER_NODES
;
2692 struct va_format vaf
;
2695 va_start(args
, fmt
);
2700 pr_warn("%pV", &vaf
);
2705 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
2706 current
->comm
, order
, gfp_mask
);
2709 if (!should_suppress_show_mem())
2713 static inline struct page
*
2714 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
2715 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
2717 struct oom_control oc
= {
2718 .zonelist
= ac
->zonelist
,
2719 .nodemask
= ac
->nodemask
,
2720 .gfp_mask
= gfp_mask
,
2725 *did_some_progress
= 0;
2728 * Acquire the oom lock. If that fails, somebody else is
2729 * making progress for us.
2731 if (!mutex_trylock(&oom_lock
)) {
2732 *did_some_progress
= 1;
2733 schedule_timeout_uninterruptible(1);
2738 * Go through the zonelist yet one more time, keep very high watermark
2739 * here, this is only to catch a parallel oom killing, we must fail if
2740 * we're still under heavy pressure.
2742 page
= get_page_from_freelist(gfp_mask
| __GFP_HARDWALL
, order
,
2743 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
2747 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2748 /* Coredumps can quickly deplete all memory reserves */
2749 if (current
->flags
& PF_DUMPCORE
)
2751 /* The OOM killer will not help higher order allocs */
2752 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2754 /* The OOM killer does not needlessly kill tasks for lowmem */
2755 if (ac
->high_zoneidx
< ZONE_NORMAL
)
2757 /* The OOM killer does not compensate for IO-less reclaim */
2758 if (!(gfp_mask
& __GFP_FS
)) {
2760 * XXX: Page reclaim didn't yield anything,
2761 * and the OOM killer can't be invoked, but
2762 * keep looping as per tradition.
2764 *did_some_progress
= 1;
2767 if (pm_suspended_storage())
2769 /* The OOM killer may not free memory on a specific node */
2770 if (gfp_mask
& __GFP_THISNODE
)
2773 /* Exhausted what can be done so it's blamo time */
2774 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
))
2775 *did_some_progress
= 1;
2777 mutex_unlock(&oom_lock
);
2781 #ifdef CONFIG_COMPACTION
2782 /* Try memory compaction for high-order allocations before reclaim */
2783 static struct page
*
2784 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2785 int alloc_flags
, const struct alloc_context
*ac
,
2786 enum migrate_mode mode
, int *contended_compaction
,
2787 bool *deferred_compaction
)
2789 unsigned long compact_result
;
2795 current
->flags
|= PF_MEMALLOC
;
2796 compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
2797 mode
, contended_compaction
);
2798 current
->flags
&= ~PF_MEMALLOC
;
2800 switch (compact_result
) {
2801 case COMPACT_DEFERRED
:
2802 *deferred_compaction
= true;
2804 case COMPACT_SKIPPED
:
2811 * At least in one zone compaction wasn't deferred or skipped, so let's
2812 * count a compaction stall
2814 count_vm_event(COMPACTSTALL
);
2816 page
= get_page_from_freelist(gfp_mask
, order
,
2817 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
2820 struct zone
*zone
= page_zone(page
);
2822 zone
->compact_blockskip_flush
= false;
2823 compaction_defer_reset(zone
, order
, true);
2824 count_vm_event(COMPACTSUCCESS
);
2829 * It's bad if compaction run occurs and fails. The most likely reason
2830 * is that pages exist, but not enough to satisfy watermarks.
2832 count_vm_event(COMPACTFAIL
);
2839 static inline struct page
*
2840 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2841 int alloc_flags
, const struct alloc_context
*ac
,
2842 enum migrate_mode mode
, int *contended_compaction
,
2843 bool *deferred_compaction
)
2847 #endif /* CONFIG_COMPACTION */
2849 /* Perform direct synchronous page reclaim */
2851 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
2852 const struct alloc_context
*ac
)
2854 struct reclaim_state reclaim_state
;
2859 /* We now go into synchronous reclaim */
2860 cpuset_memory_pressure_bump();
2861 current
->flags
|= PF_MEMALLOC
;
2862 lockdep_set_current_reclaim_state(gfp_mask
);
2863 reclaim_state
.reclaimed_slab
= 0;
2864 current
->reclaim_state
= &reclaim_state
;
2866 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
2869 current
->reclaim_state
= NULL
;
2870 lockdep_clear_current_reclaim_state();
2871 current
->flags
&= ~PF_MEMALLOC
;
2878 /* The really slow allocator path where we enter direct reclaim */
2879 static inline struct page
*
2880 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
2881 int alloc_flags
, const struct alloc_context
*ac
,
2882 unsigned long *did_some_progress
)
2884 struct page
*page
= NULL
;
2885 bool drained
= false;
2887 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
2888 if (unlikely(!(*did_some_progress
)))
2891 /* After successful reclaim, reconsider all zones for allocation */
2892 if (IS_ENABLED(CONFIG_NUMA
))
2893 zlc_clear_zones_full(ac
->zonelist
);
2896 page
= get_page_from_freelist(gfp_mask
, order
,
2897 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
2900 * If an allocation failed after direct reclaim, it could be because
2901 * pages are pinned on the per-cpu lists. Drain them and try again
2903 if (!page
&& !drained
) {
2904 drain_all_pages(NULL
);
2913 * This is called in the allocator slow-path if the allocation request is of
2914 * sufficient urgency to ignore watermarks and take other desperate measures
2916 static inline struct page
*
2917 __alloc_pages_high_priority(gfp_t gfp_mask
, unsigned int order
,
2918 const struct alloc_context
*ac
)
2923 page
= get_page_from_freelist(gfp_mask
, order
,
2924 ALLOC_NO_WATERMARKS
, ac
);
2926 if (!page
&& gfp_mask
& __GFP_NOFAIL
)
2927 wait_iff_congested(ac
->preferred_zone
, BLK_RW_ASYNC
,
2929 } while (!page
&& (gfp_mask
& __GFP_NOFAIL
));
2934 static void wake_all_kswapds(unsigned int order
, const struct alloc_context
*ac
)
2939 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
2940 ac
->high_zoneidx
, ac
->nodemask
)
2941 wakeup_kswapd(zone
, order
, zone_idx(ac
->preferred_zone
));
2945 gfp_to_alloc_flags(gfp_t gfp_mask
)
2947 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
2948 const bool atomic
= !(gfp_mask
& (__GFP_WAIT
| __GFP_NO_KSWAPD
));
2950 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2951 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
2954 * The caller may dip into page reserves a bit more if the caller
2955 * cannot run direct reclaim, or if the caller has realtime scheduling
2956 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
2957 * set both ALLOC_HARDER (atomic == true) and ALLOC_HIGH (__GFP_HIGH).
2959 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
2963 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
2964 * if it can't schedule.
2966 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2967 alloc_flags
|= ALLOC_HARDER
;
2969 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
2970 * comment for __cpuset_node_allowed().
2972 alloc_flags
&= ~ALLOC_CPUSET
;
2973 } else if (unlikely(rt_task(current
)) && !in_interrupt())
2974 alloc_flags
|= ALLOC_HARDER
;
2976 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
2977 if (gfp_mask
& __GFP_MEMALLOC
)
2978 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2979 else if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
2980 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2981 else if (!in_interrupt() &&
2982 ((current
->flags
& PF_MEMALLOC
) ||
2983 unlikely(test_thread_flag(TIF_MEMDIE
))))
2984 alloc_flags
|= ALLOC_NO_WATERMARKS
;
2987 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
2988 alloc_flags
|= ALLOC_CMA
;
2993 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
2995 return !!(gfp_to_alloc_flags(gfp_mask
) & ALLOC_NO_WATERMARKS
);
2998 static inline struct page
*
2999 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
3000 struct alloc_context
*ac
)
3002 const gfp_t wait
= gfp_mask
& __GFP_WAIT
;
3003 struct page
*page
= NULL
;
3005 unsigned long pages_reclaimed
= 0;
3006 unsigned long did_some_progress
;
3007 enum migrate_mode migration_mode
= MIGRATE_ASYNC
;
3008 bool deferred_compaction
= false;
3009 int contended_compaction
= COMPACT_CONTENDED_NONE
;
3012 * In the slowpath, we sanity check order to avoid ever trying to
3013 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3014 * be using allocators in order of preference for an area that is
3017 if (order
>= MAX_ORDER
) {
3018 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
3023 * If this allocation cannot block and it is for a specific node, then
3024 * fail early. There's no need to wakeup kswapd or retry for a
3025 * speculative node-specific allocation.
3027 if (IS_ENABLED(CONFIG_NUMA
) && (gfp_mask
& __GFP_THISNODE
) && !wait
)
3031 if (!(gfp_mask
& __GFP_NO_KSWAPD
))
3032 wake_all_kswapds(order
, ac
);
3035 * OK, we're below the kswapd watermark and have kicked background
3036 * reclaim. Now things get more complex, so set up alloc_flags according
3037 * to how we want to proceed.
3039 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
3042 * Find the true preferred zone if the allocation is unconstrained by
3045 if (!(alloc_flags
& ALLOC_CPUSET
) && !ac
->nodemask
) {
3046 struct zoneref
*preferred_zoneref
;
3047 preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3048 ac
->high_zoneidx
, NULL
, &ac
->preferred_zone
);
3049 ac
->classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
3052 /* This is the last chance, in general, before the goto nopage. */
3053 page
= get_page_from_freelist(gfp_mask
, order
,
3054 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3058 /* Allocate without watermarks if the context allows */
3059 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
3061 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
3062 * the allocation is high priority and these type of
3063 * allocations are system rather than user orientated
3065 ac
->zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
3067 page
= __alloc_pages_high_priority(gfp_mask
, order
, ac
);
3074 /* Atomic allocations - we can't balance anything */
3077 * All existing users of the deprecated __GFP_NOFAIL are
3078 * blockable, so warn of any new users that actually allow this
3079 * type of allocation to fail.
3081 WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
);
3085 /* Avoid recursion of direct reclaim */
3086 if (current
->flags
& PF_MEMALLOC
)
3089 /* Avoid allocations with no watermarks from looping endlessly */
3090 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
3094 * Try direct compaction. The first pass is asynchronous. Subsequent
3095 * attempts after direct reclaim are synchronous
3097 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
3099 &contended_compaction
,
3100 &deferred_compaction
);
3104 /* Checks for THP-specific high-order allocations */
3105 if ((gfp_mask
& GFP_TRANSHUGE
) == GFP_TRANSHUGE
) {
3107 * If compaction is deferred for high-order allocations, it is
3108 * because sync compaction recently failed. If this is the case
3109 * and the caller requested a THP allocation, we do not want
3110 * to heavily disrupt the system, so we fail the allocation
3111 * instead of entering direct reclaim.
3113 if (deferred_compaction
)
3117 * In all zones where compaction was attempted (and not
3118 * deferred or skipped), lock contention has been detected.
3119 * For THP allocation we do not want to disrupt the others
3120 * so we fallback to base pages instead.
3122 if (contended_compaction
== COMPACT_CONTENDED_LOCK
)
3126 * If compaction was aborted due to need_resched(), we do not
3127 * want to further increase allocation latency, unless it is
3128 * khugepaged trying to collapse.
3130 if (contended_compaction
== COMPACT_CONTENDED_SCHED
3131 && !(current
->flags
& PF_KTHREAD
))
3136 * It can become very expensive to allocate transparent hugepages at
3137 * fault, so use asynchronous memory compaction for THP unless it is
3138 * khugepaged trying to collapse.
3140 if ((gfp_mask
& GFP_TRANSHUGE
) != GFP_TRANSHUGE
||
3141 (current
->flags
& PF_KTHREAD
))
3142 migration_mode
= MIGRATE_SYNC_LIGHT
;
3144 /* Try direct reclaim and then allocating */
3145 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
3146 &did_some_progress
);
3150 /* Do not loop if specifically requested */
3151 if (gfp_mask
& __GFP_NORETRY
)
3154 /* Keep reclaiming pages as long as there is reasonable progress */
3155 pages_reclaimed
+= did_some_progress
;
3156 if ((did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
) ||
3157 ((gfp_mask
& __GFP_REPEAT
) && pages_reclaimed
< (1 << order
))) {
3158 /* Wait for some write requests to complete then retry */
3159 wait_iff_congested(ac
->preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
3163 /* Reclaim has failed us, start killing things */
3164 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
3168 /* Retry as long as the OOM killer is making progress */
3169 if (did_some_progress
)
3174 * High-order allocations do not necessarily loop after
3175 * direct reclaim and reclaim/compaction depends on compaction
3176 * being called after reclaim so call directly if necessary
3178 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
,
3180 &contended_compaction
,
3181 &deferred_compaction
);
3185 warn_alloc_failed(gfp_mask
, order
, NULL
);
3191 * This is the 'heart' of the zoned buddy allocator.
3194 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
3195 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
3197 struct zoneref
*preferred_zoneref
;
3198 struct page
*page
= NULL
;
3199 unsigned int cpuset_mems_cookie
;
3200 int alloc_flags
= ALLOC_WMARK_LOW
|ALLOC_CPUSET
|ALLOC_FAIR
;
3201 gfp_t alloc_mask
; /* The gfp_t that was actually used for allocation */
3202 struct alloc_context ac
= {
3203 .high_zoneidx
= gfp_zone(gfp_mask
),
3204 .nodemask
= nodemask
,
3205 .migratetype
= gfpflags_to_migratetype(gfp_mask
),
3208 gfp_mask
&= gfp_allowed_mask
;
3210 lockdep_trace_alloc(gfp_mask
);
3212 might_sleep_if(gfp_mask
& __GFP_WAIT
);
3214 if (should_fail_alloc_page(gfp_mask
, order
))
3218 * Check the zones suitable for the gfp_mask contain at least one
3219 * valid zone. It's possible to have an empty zonelist as a result
3220 * of __GFP_THISNODE and a memoryless node
3222 if (unlikely(!zonelist
->_zonerefs
->zone
))
3225 if (IS_ENABLED(CONFIG_CMA
) && ac
.migratetype
== MIGRATE_MOVABLE
)
3226 alloc_flags
|= ALLOC_CMA
;
3229 cpuset_mems_cookie
= read_mems_allowed_begin();
3231 /* We set it here, as __alloc_pages_slowpath might have changed it */
3232 ac
.zonelist
= zonelist
;
3234 /* Dirty zone balancing only done in the fast path */
3235 ac
.spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
3237 /* The preferred zone is used for statistics later */
3238 preferred_zoneref
= first_zones_zonelist(ac
.zonelist
, ac
.high_zoneidx
,
3239 ac
.nodemask
? : &cpuset_current_mems_allowed
,
3240 &ac
.preferred_zone
);
3241 if (!ac
.preferred_zone
)
3243 ac
.classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
3245 /* First allocation attempt */
3246 alloc_mask
= gfp_mask
|__GFP_HARDWALL
;
3247 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
3248 if (unlikely(!page
)) {
3250 * Runtime PM, block IO and its error handling path
3251 * can deadlock because I/O on the device might not
3254 alloc_mask
= memalloc_noio_flags(gfp_mask
);
3255 ac
.spread_dirty_pages
= false;
3257 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
3260 if (kmemcheck_enabled
&& page
)
3261 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
3263 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
3267 * When updating a task's mems_allowed, it is possible to race with
3268 * parallel threads in such a way that an allocation can fail while
3269 * the mask is being updated. If a page allocation is about to fail,
3270 * check if the cpuset changed during allocation and if so, retry.
3272 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
)))
3277 EXPORT_SYMBOL(__alloc_pages_nodemask
);
3280 * Common helper functions.
3282 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
3287 * __get_free_pages() returns a 32-bit address, which cannot represent
3290 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
3292 page
= alloc_pages(gfp_mask
, order
);
3295 return (unsigned long) page_address(page
);
3297 EXPORT_SYMBOL(__get_free_pages
);
3299 unsigned long get_zeroed_page(gfp_t gfp_mask
)
3301 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
3303 EXPORT_SYMBOL(get_zeroed_page
);
3305 void __free_pages(struct page
*page
, unsigned int order
)
3307 if (put_page_testzero(page
)) {
3309 free_hot_cold_page(page
, false);
3311 __free_pages_ok(page
, order
);
3315 EXPORT_SYMBOL(__free_pages
);
3317 void free_pages(unsigned long addr
, unsigned int order
)
3320 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3321 __free_pages(virt_to_page((void *)addr
), order
);
3325 EXPORT_SYMBOL(free_pages
);
3329 * An arbitrary-length arbitrary-offset area of memory which resides
3330 * within a 0 or higher order page. Multiple fragments within that page
3331 * are individually refcounted, in the page's reference counter.
3333 * The page_frag functions below provide a simple allocation framework for
3334 * page fragments. This is used by the network stack and network device
3335 * drivers to provide a backing region of memory for use as either an
3336 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3338 static struct page
*__page_frag_refill(struct page_frag_cache
*nc
,
3341 struct page
*page
= NULL
;
3342 gfp_t gfp
= gfp_mask
;
3344 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3345 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
3347 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
3348 PAGE_FRAG_CACHE_MAX_ORDER
);
3349 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
3351 if (unlikely(!page
))
3352 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
3354 nc
->va
= page
? page_address(page
) : NULL
;
3359 void *__alloc_page_frag(struct page_frag_cache
*nc
,
3360 unsigned int fragsz
, gfp_t gfp_mask
)
3362 unsigned int size
= PAGE_SIZE
;
3366 if (unlikely(!nc
->va
)) {
3368 page
= __page_frag_refill(nc
, gfp_mask
);
3372 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3373 /* if size can vary use size else just use PAGE_SIZE */
3376 /* Even if we own the page, we do not use atomic_set().
3377 * This would break get_page_unless_zero() users.
3379 atomic_add(size
- 1, &page
->_count
);
3381 /* reset page count bias and offset to start of new frag */
3382 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
3383 nc
->pagecnt_bias
= size
;
3387 offset
= nc
->offset
- fragsz
;
3388 if (unlikely(offset
< 0)) {
3389 page
= virt_to_page(nc
->va
);
3391 if (!atomic_sub_and_test(nc
->pagecnt_bias
, &page
->_count
))
3394 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3395 /* if size can vary use size else just use PAGE_SIZE */
3398 /* OK, page count is 0, we can safely set it */
3399 atomic_set(&page
->_count
, size
);
3401 /* reset page count bias and offset to start of new frag */
3402 nc
->pagecnt_bias
= size
;
3403 offset
= size
- fragsz
;
3407 nc
->offset
= offset
;
3409 return nc
->va
+ offset
;
3411 EXPORT_SYMBOL(__alloc_page_frag
);
3414 * Frees a page fragment allocated out of either a compound or order 0 page.
3416 void __free_page_frag(void *addr
)
3418 struct page
*page
= virt_to_head_page(addr
);
3420 if (unlikely(put_page_testzero(page
)))
3421 __free_pages_ok(page
, compound_order(page
));
3423 EXPORT_SYMBOL(__free_page_frag
);
3426 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
3427 * of the current memory cgroup.
3429 * It should be used when the caller would like to use kmalloc, but since the
3430 * allocation is large, it has to fall back to the page allocator.
3432 struct page
*alloc_kmem_pages(gfp_t gfp_mask
, unsigned int order
)
3436 page
= alloc_pages(gfp_mask
, order
);
3437 if (page
&& memcg_kmem_charge(page
, gfp_mask
, order
) != 0) {
3438 __free_pages(page
, order
);
3444 struct page
*alloc_kmem_pages_node(int nid
, gfp_t gfp_mask
, unsigned int order
)
3448 page
= alloc_pages_node(nid
, gfp_mask
, order
);
3449 if (page
&& memcg_kmem_charge(page
, gfp_mask
, order
) != 0) {
3450 __free_pages(page
, order
);
3457 * __free_kmem_pages and free_kmem_pages will free pages allocated with
3460 void __free_kmem_pages(struct page
*page
, unsigned int order
)
3462 memcg_kmem_uncharge(page
, order
);
3463 __free_pages(page
, order
);
3466 void free_kmem_pages(unsigned long addr
, unsigned int order
)
3469 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3470 __free_kmem_pages(virt_to_page((void *)addr
), order
);
3474 static void *make_alloc_exact(unsigned long addr
, unsigned order
, size_t size
)
3477 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
3478 unsigned long used
= addr
+ PAGE_ALIGN(size
);
3480 split_page(virt_to_page((void *)addr
), order
);
3481 while (used
< alloc_end
) {
3486 return (void *)addr
;
3490 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
3491 * @size: the number of bytes to allocate
3492 * @gfp_mask: GFP flags for the allocation
3494 * This function is similar to alloc_pages(), except that it allocates the
3495 * minimum number of pages to satisfy the request. alloc_pages() can only
3496 * allocate memory in power-of-two pages.
3498 * This function is also limited by MAX_ORDER.
3500 * Memory allocated by this function must be released by free_pages_exact().
3502 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
3504 unsigned int order
= get_order(size
);
3507 addr
= __get_free_pages(gfp_mask
, order
);
3508 return make_alloc_exact(addr
, order
, size
);
3510 EXPORT_SYMBOL(alloc_pages_exact
);
3513 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3515 * @nid: the preferred node ID where memory should be allocated
3516 * @size: the number of bytes to allocate
3517 * @gfp_mask: GFP flags for the allocation
3519 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3522 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
3524 unsigned order
= get_order(size
);
3525 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
3528 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
3532 * free_pages_exact - release memory allocated via alloc_pages_exact()
3533 * @virt: the value returned by alloc_pages_exact.
3534 * @size: size of allocation, same value as passed to alloc_pages_exact().
3536 * Release the memory allocated by a previous call to alloc_pages_exact.
3538 void free_pages_exact(void *virt
, size_t size
)
3540 unsigned long addr
= (unsigned long)virt
;
3541 unsigned long end
= addr
+ PAGE_ALIGN(size
);
3543 while (addr
< end
) {
3548 EXPORT_SYMBOL(free_pages_exact
);
3551 * nr_free_zone_pages - count number of pages beyond high watermark
3552 * @offset: The zone index of the highest zone
3554 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3555 * high watermark within all zones at or below a given zone index. For each
3556 * zone, the number of pages is calculated as:
3557 * managed_pages - high_pages
3559 static unsigned long nr_free_zone_pages(int offset
)
3564 /* Just pick one node, since fallback list is circular */
3565 unsigned long sum
= 0;
3567 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
3569 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
3570 unsigned long size
= zone
->managed_pages
;
3571 unsigned long high
= high_wmark_pages(zone
);
3580 * nr_free_buffer_pages - count number of pages beyond high watermark
3582 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3583 * watermark within ZONE_DMA and ZONE_NORMAL.
3585 unsigned long nr_free_buffer_pages(void)
3587 return nr_free_zone_pages(gfp_zone(GFP_USER
));
3589 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
3592 * nr_free_pagecache_pages - count number of pages beyond high watermark
3594 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3595 * high watermark within all zones.
3597 unsigned long nr_free_pagecache_pages(void)
3599 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
3602 static inline void show_node(struct zone
*zone
)
3604 if (IS_ENABLED(CONFIG_NUMA
))
3605 printk("Node %d ", zone_to_nid(zone
));
3608 void si_meminfo(struct sysinfo
*val
)
3610 val
->totalram
= totalram_pages
;
3611 val
->sharedram
= global_page_state(NR_SHMEM
);
3612 val
->freeram
= global_page_state(NR_FREE_PAGES
);
3613 val
->bufferram
= nr_blockdev_pages();
3614 val
->totalhigh
= totalhigh_pages
;
3615 val
->freehigh
= nr_free_highpages();
3616 val
->mem_unit
= PAGE_SIZE
;
3619 EXPORT_SYMBOL(si_meminfo
);
3622 void si_meminfo_node(struct sysinfo
*val
, int nid
)
3624 int zone_type
; /* needs to be signed */
3625 unsigned long managed_pages
= 0;
3626 pg_data_t
*pgdat
= NODE_DATA(nid
);
3628 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
3629 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
3630 val
->totalram
= managed_pages
;
3631 val
->sharedram
= node_page_state(nid
, NR_SHMEM
);
3632 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
3633 #ifdef CONFIG_HIGHMEM
3634 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].managed_pages
;
3635 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
3641 val
->mem_unit
= PAGE_SIZE
;
3646 * Determine whether the node should be displayed or not, depending on whether
3647 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3649 bool skip_free_areas_node(unsigned int flags
, int nid
)
3652 unsigned int cpuset_mems_cookie
;
3654 if (!(flags
& SHOW_MEM_FILTER_NODES
))
3658 cpuset_mems_cookie
= read_mems_allowed_begin();
3659 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
3660 } while (read_mems_allowed_retry(cpuset_mems_cookie
));
3665 #define K(x) ((x) << (PAGE_SHIFT-10))
3667 static void show_migration_types(unsigned char type
)
3669 static const char types
[MIGRATE_TYPES
] = {
3670 [MIGRATE_UNMOVABLE
] = 'U',
3671 [MIGRATE_RECLAIMABLE
] = 'E',
3672 [MIGRATE_MOVABLE
] = 'M',
3673 [MIGRATE_RESERVE
] = 'R',
3675 [MIGRATE_CMA
] = 'C',
3677 #ifdef CONFIG_MEMORY_ISOLATION
3678 [MIGRATE_ISOLATE
] = 'I',
3681 char tmp
[MIGRATE_TYPES
+ 1];
3685 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
3686 if (type
& (1 << i
))
3691 printk("(%s) ", tmp
);
3695 * Show free area list (used inside shift_scroll-lock stuff)
3696 * We also calculate the percentage fragmentation. We do this by counting the
3697 * memory on each free list with the exception of the first item on the list.
3700 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
3703 void show_free_areas(unsigned int filter
)
3705 unsigned long free_pcp
= 0;
3709 for_each_populated_zone(zone
) {
3710 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3713 for_each_online_cpu(cpu
)
3714 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
3717 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3718 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3719 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
3720 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3721 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3722 " free:%lu free_pcp:%lu free_cma:%lu\n",
3723 global_page_state(NR_ACTIVE_ANON
),
3724 global_page_state(NR_INACTIVE_ANON
),
3725 global_page_state(NR_ISOLATED_ANON
),
3726 global_page_state(NR_ACTIVE_FILE
),
3727 global_page_state(NR_INACTIVE_FILE
),
3728 global_page_state(NR_ISOLATED_FILE
),
3729 global_page_state(NR_UNEVICTABLE
),
3730 global_page_state(NR_FILE_DIRTY
),
3731 global_page_state(NR_WRITEBACK
),
3732 global_page_state(NR_UNSTABLE_NFS
),
3733 global_page_state(NR_SLAB_RECLAIMABLE
),
3734 global_page_state(NR_SLAB_UNRECLAIMABLE
),
3735 global_page_state(NR_FILE_MAPPED
),
3736 global_page_state(NR_SHMEM
),
3737 global_page_state(NR_PAGETABLE
),
3738 global_page_state(NR_BOUNCE
),
3739 global_page_state(NR_FREE_PAGES
),
3741 global_page_state(NR_FREE_CMA_PAGES
));
3743 for_each_populated_zone(zone
) {
3746 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3750 for_each_online_cpu(cpu
)
3751 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
3759 " active_anon:%lukB"
3760 " inactive_anon:%lukB"
3761 " active_file:%lukB"
3762 " inactive_file:%lukB"
3763 " unevictable:%lukB"
3764 " isolated(anon):%lukB"
3765 " isolated(file):%lukB"
3773 " slab_reclaimable:%lukB"
3774 " slab_unreclaimable:%lukB"
3775 " kernel_stack:%lukB"
3782 " writeback_tmp:%lukB"
3783 " pages_scanned:%lu"
3784 " all_unreclaimable? %s"
3787 K(zone_page_state(zone
, NR_FREE_PAGES
)),
3788 K(min_wmark_pages(zone
)),
3789 K(low_wmark_pages(zone
)),
3790 K(high_wmark_pages(zone
)),
3791 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
3792 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
3793 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
3794 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
3795 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
3796 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
3797 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
3798 K(zone
->present_pages
),
3799 K(zone
->managed_pages
),
3800 K(zone_page_state(zone
, NR_MLOCK
)),
3801 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
3802 K(zone_page_state(zone
, NR_WRITEBACK
)),
3803 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
3804 K(zone_page_state(zone
, NR_SHMEM
)),
3805 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
3806 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
3807 zone_page_state(zone
, NR_KERNEL_STACK
) *
3809 K(zone_page_state(zone
, NR_PAGETABLE
)),
3810 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
3811 K(zone_page_state(zone
, NR_BOUNCE
)),
3813 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
3814 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)),
3815 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
3816 K(zone_page_state(zone
, NR_PAGES_SCANNED
)),
3817 (!zone_reclaimable(zone
) ? "yes" : "no")
3819 printk("lowmem_reserve[]:");
3820 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3821 printk(" %ld", zone
->lowmem_reserve
[i
]);
3825 for_each_populated_zone(zone
) {
3826 unsigned long nr
[MAX_ORDER
], flags
, order
, total
= 0;
3827 unsigned char types
[MAX_ORDER
];
3829 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3832 printk("%s: ", zone
->name
);
3834 spin_lock_irqsave(&zone
->lock
, flags
);
3835 for (order
= 0; order
< MAX_ORDER
; order
++) {
3836 struct free_area
*area
= &zone
->free_area
[order
];
3839 nr
[order
] = area
->nr_free
;
3840 total
+= nr
[order
] << order
;
3843 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
3844 if (!list_empty(&area
->free_list
[type
]))
3845 types
[order
] |= 1 << type
;
3848 spin_unlock_irqrestore(&zone
->lock
, flags
);
3849 for (order
= 0; order
< MAX_ORDER
; order
++) {
3850 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
3852 show_migration_types(types
[order
]);
3854 printk("= %lukB\n", K(total
));
3857 hugetlb_show_meminfo();
3859 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
3861 show_swap_cache_info();
3864 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
3866 zoneref
->zone
= zone
;
3867 zoneref
->zone_idx
= zone_idx(zone
);
3871 * Builds allocation fallback zone lists.
3873 * Add all populated zones of a node to the zonelist.
3875 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
3879 enum zone_type zone_type
= MAX_NR_ZONES
;
3883 zone
= pgdat
->node_zones
+ zone_type
;
3884 if (populated_zone(zone
)) {
3885 zoneref_set_zone(zone
,
3886 &zonelist
->_zonerefs
[nr_zones
++]);
3887 check_highest_zone(zone_type
);
3889 } while (zone_type
);
3897 * 0 = automatic detection of better ordering.
3898 * 1 = order by ([node] distance, -zonetype)
3899 * 2 = order by (-zonetype, [node] distance)
3901 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3902 * the same zonelist. So only NUMA can configure this param.
3904 #define ZONELIST_ORDER_DEFAULT 0
3905 #define ZONELIST_ORDER_NODE 1
3906 #define ZONELIST_ORDER_ZONE 2
3908 /* zonelist order in the kernel.
3909 * set_zonelist_order() will set this to NODE or ZONE.
3911 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3912 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
3916 /* The value user specified ....changed by config */
3917 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3918 /* string for sysctl */
3919 #define NUMA_ZONELIST_ORDER_LEN 16
3920 char numa_zonelist_order
[16] = "default";
3923 * interface for configure zonelist ordering.
3924 * command line option "numa_zonelist_order"
3925 * = "[dD]efault - default, automatic configuration.
3926 * = "[nN]ode - order by node locality, then by zone within node
3927 * = "[zZ]one - order by zone, then by locality within zone
3930 static int __parse_numa_zonelist_order(char *s
)
3932 if (*s
== 'd' || *s
== 'D') {
3933 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3934 } else if (*s
== 'n' || *s
== 'N') {
3935 user_zonelist_order
= ZONELIST_ORDER_NODE
;
3936 } else if (*s
== 'z' || *s
== 'Z') {
3937 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
3940 "Ignoring invalid numa_zonelist_order value: "
3947 static __init
int setup_numa_zonelist_order(char *s
)
3954 ret
= __parse_numa_zonelist_order(s
);
3956 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
3960 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
3963 * sysctl handler for numa_zonelist_order
3965 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
3966 void __user
*buffer
, size_t *length
,
3969 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
3971 static DEFINE_MUTEX(zl_order_mutex
);
3973 mutex_lock(&zl_order_mutex
);
3975 if (strlen((char *)table
->data
) >= NUMA_ZONELIST_ORDER_LEN
) {
3979 strcpy(saved_string
, (char *)table
->data
);
3981 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
3985 int oldval
= user_zonelist_order
;
3987 ret
= __parse_numa_zonelist_order((char *)table
->data
);
3990 * bogus value. restore saved string
3992 strncpy((char *)table
->data
, saved_string
,
3993 NUMA_ZONELIST_ORDER_LEN
);
3994 user_zonelist_order
= oldval
;
3995 } else if (oldval
!= user_zonelist_order
) {
3996 mutex_lock(&zonelists_mutex
);
3997 build_all_zonelists(NULL
, NULL
);
3998 mutex_unlock(&zonelists_mutex
);
4002 mutex_unlock(&zl_order_mutex
);
4007 #define MAX_NODE_LOAD (nr_online_nodes)
4008 static int node_load
[MAX_NUMNODES
];
4011 * find_next_best_node - find the next node that should appear in a given node's fallback list
4012 * @node: node whose fallback list we're appending
4013 * @used_node_mask: nodemask_t of already used nodes
4015 * We use a number of factors to determine which is the next node that should
4016 * appear on a given node's fallback list. The node should not have appeared
4017 * already in @node's fallback list, and it should be the next closest node
4018 * according to the distance array (which contains arbitrary distance values
4019 * from each node to each node in the system), and should also prefer nodes
4020 * with no CPUs, since presumably they'll have very little allocation pressure
4021 * on them otherwise.
4022 * It returns -1 if no node is found.
4024 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
4027 int min_val
= INT_MAX
;
4028 int best_node
= NUMA_NO_NODE
;
4029 const struct cpumask
*tmp
= cpumask_of_node(0);
4031 /* Use the local node if we haven't already */
4032 if (!node_isset(node
, *used_node_mask
)) {
4033 node_set(node
, *used_node_mask
);
4037 for_each_node_state(n
, N_MEMORY
) {
4039 /* Don't want a node to appear more than once */
4040 if (node_isset(n
, *used_node_mask
))
4043 /* Use the distance array to find the distance */
4044 val
= node_distance(node
, n
);
4046 /* Penalize nodes under us ("prefer the next node") */
4049 /* Give preference to headless and unused nodes */
4050 tmp
= cpumask_of_node(n
);
4051 if (!cpumask_empty(tmp
))
4052 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
4054 /* Slight preference for less loaded node */
4055 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
4056 val
+= node_load
[n
];
4058 if (val
< min_val
) {
4065 node_set(best_node
, *used_node_mask
);
4072 * Build zonelists ordered by node and zones within node.
4073 * This results in maximum locality--normal zone overflows into local
4074 * DMA zone, if any--but risks exhausting DMA zone.
4076 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
4079 struct zonelist
*zonelist
;
4081 zonelist
= &pgdat
->node_zonelists
[0];
4082 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
4084 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4085 zonelist
->_zonerefs
[j
].zone
= NULL
;
4086 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4090 * Build gfp_thisnode zonelists
4092 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
4095 struct zonelist
*zonelist
;
4097 zonelist
= &pgdat
->node_zonelists
[1];
4098 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4099 zonelist
->_zonerefs
[j
].zone
= NULL
;
4100 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4104 * Build zonelists ordered by zone and nodes within zones.
4105 * This results in conserving DMA zone[s] until all Normal memory is
4106 * exhausted, but results in overflowing to remote node while memory
4107 * may still exist in local DMA zone.
4109 static int node_order
[MAX_NUMNODES
];
4111 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
4114 int zone_type
; /* needs to be signed */
4116 struct zonelist
*zonelist
;
4118 zonelist
= &pgdat
->node_zonelists
[0];
4120 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
4121 for (j
= 0; j
< nr_nodes
; j
++) {
4122 node
= node_order
[j
];
4123 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
4124 if (populated_zone(z
)) {
4126 &zonelist
->_zonerefs
[pos
++]);
4127 check_highest_zone(zone_type
);
4131 zonelist
->_zonerefs
[pos
].zone
= NULL
;
4132 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
4135 #if defined(CONFIG_64BIT)
4137 * Devices that require DMA32/DMA are relatively rare and do not justify a
4138 * penalty to every machine in case the specialised case applies. Default
4139 * to Node-ordering on 64-bit NUMA machines
4141 static int default_zonelist_order(void)
4143 return ZONELIST_ORDER_NODE
;
4147 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4148 * by the kernel. If processes running on node 0 deplete the low memory zone
4149 * then reclaim will occur more frequency increasing stalls and potentially
4150 * be easier to OOM if a large percentage of the zone is under writeback or
4151 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4152 * Hence, default to zone ordering on 32-bit.
4154 static int default_zonelist_order(void)
4156 return ZONELIST_ORDER_ZONE
;
4158 #endif /* CONFIG_64BIT */
4160 static void set_zonelist_order(void)
4162 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
4163 current_zonelist_order
= default_zonelist_order();
4165 current_zonelist_order
= user_zonelist_order
;
4168 static void build_zonelists(pg_data_t
*pgdat
)
4172 nodemask_t used_mask
;
4173 int local_node
, prev_node
;
4174 struct zonelist
*zonelist
;
4175 int order
= current_zonelist_order
;
4177 /* initialize zonelists */
4178 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
4179 zonelist
= pgdat
->node_zonelists
+ i
;
4180 zonelist
->_zonerefs
[0].zone
= NULL
;
4181 zonelist
->_zonerefs
[0].zone_idx
= 0;
4184 /* NUMA-aware ordering of nodes */
4185 local_node
= pgdat
->node_id
;
4186 load
= nr_online_nodes
;
4187 prev_node
= local_node
;
4188 nodes_clear(used_mask
);
4190 memset(node_order
, 0, sizeof(node_order
));
4193 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
4195 * We don't want to pressure a particular node.
4196 * So adding penalty to the first node in same
4197 * distance group to make it round-robin.
4199 if (node_distance(local_node
, node
) !=
4200 node_distance(local_node
, prev_node
))
4201 node_load
[node
] = load
;
4205 if (order
== ZONELIST_ORDER_NODE
)
4206 build_zonelists_in_node_order(pgdat
, node
);
4208 node_order
[j
++] = node
; /* remember order */
4211 if (order
== ZONELIST_ORDER_ZONE
) {
4212 /* calculate node order -- i.e., DMA last! */
4213 build_zonelists_in_zone_order(pgdat
, j
);
4216 build_thisnode_zonelists(pgdat
);
4219 /* Construct the zonelist performance cache - see further mmzone.h */
4220 static void build_zonelist_cache(pg_data_t
*pgdat
)
4222 struct zonelist
*zonelist
;
4223 struct zonelist_cache
*zlc
;
4226 zonelist
= &pgdat
->node_zonelists
[0];
4227 zonelist
->zlcache_ptr
= zlc
= &zonelist
->zlcache
;
4228 bitmap_zero(zlc
->fullzones
, MAX_ZONES_PER_ZONELIST
);
4229 for (z
= zonelist
->_zonerefs
; z
->zone
; z
++)
4230 zlc
->z_to_n
[z
- zonelist
->_zonerefs
] = zonelist_node_idx(z
);
4233 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4235 * Return node id of node used for "local" allocations.
4236 * I.e., first node id of first zone in arg node's generic zonelist.
4237 * Used for initializing percpu 'numa_mem', which is used primarily
4238 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4240 int local_memory_node(int node
)
4244 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
4245 gfp_zone(GFP_KERNEL
),
4252 #else /* CONFIG_NUMA */
4254 static void set_zonelist_order(void)
4256 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
4259 static void build_zonelists(pg_data_t
*pgdat
)
4261 int node
, local_node
;
4263 struct zonelist
*zonelist
;
4265 local_node
= pgdat
->node_id
;
4267 zonelist
= &pgdat
->node_zonelists
[0];
4268 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4271 * Now we build the zonelist so that it contains the zones
4272 * of all the other nodes.
4273 * We don't want to pressure a particular node, so when
4274 * building the zones for node N, we make sure that the
4275 * zones coming right after the local ones are those from
4276 * node N+1 (modulo N)
4278 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
4279 if (!node_online(node
))
4281 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4283 for (node
= 0; node
< local_node
; node
++) {
4284 if (!node_online(node
))
4286 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4289 zonelist
->_zonerefs
[j
].zone
= NULL
;
4290 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4293 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
4294 static void build_zonelist_cache(pg_data_t
*pgdat
)
4296 pgdat
->node_zonelists
[0].zlcache_ptr
= NULL
;
4299 #endif /* CONFIG_NUMA */
4302 * Boot pageset table. One per cpu which is going to be used for all
4303 * zones and all nodes. The parameters will be set in such a way
4304 * that an item put on a list will immediately be handed over to
4305 * the buddy list. This is safe since pageset manipulation is done
4306 * with interrupts disabled.
4308 * The boot_pagesets must be kept even after bootup is complete for
4309 * unused processors and/or zones. They do play a role for bootstrapping
4310 * hotplugged processors.
4312 * zoneinfo_show() and maybe other functions do
4313 * not check if the processor is online before following the pageset pointer.
4314 * Other parts of the kernel may not check if the zone is available.
4316 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
4317 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
4318 static void setup_zone_pageset(struct zone
*zone
);
4321 * Global mutex to protect against size modification of zonelists
4322 * as well as to serialize pageset setup for the new populated zone.
4324 DEFINE_MUTEX(zonelists_mutex
);
4326 /* return values int ....just for stop_machine() */
4327 static int __build_all_zonelists(void *data
)
4331 pg_data_t
*self
= data
;
4334 memset(node_load
, 0, sizeof(node_load
));
4337 if (self
&& !node_online(self
->node_id
)) {
4338 build_zonelists(self
);
4339 build_zonelist_cache(self
);
4342 for_each_online_node(nid
) {
4343 pg_data_t
*pgdat
= NODE_DATA(nid
);
4345 build_zonelists(pgdat
);
4346 build_zonelist_cache(pgdat
);
4350 * Initialize the boot_pagesets that are going to be used
4351 * for bootstrapping processors. The real pagesets for
4352 * each zone will be allocated later when the per cpu
4353 * allocator is available.
4355 * boot_pagesets are used also for bootstrapping offline
4356 * cpus if the system is already booted because the pagesets
4357 * are needed to initialize allocators on a specific cpu too.
4358 * F.e. the percpu allocator needs the page allocator which
4359 * needs the percpu allocator in order to allocate its pagesets
4360 * (a chicken-egg dilemma).
4362 for_each_possible_cpu(cpu
) {
4363 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
4365 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4367 * We now know the "local memory node" for each node--
4368 * i.e., the node of the first zone in the generic zonelist.
4369 * Set up numa_mem percpu variable for on-line cpus. During
4370 * boot, only the boot cpu should be on-line; we'll init the
4371 * secondary cpus' numa_mem as they come on-line. During
4372 * node/memory hotplug, we'll fixup all on-line cpus.
4374 if (cpu_online(cpu
))
4375 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
4382 static noinline
void __init
4383 build_all_zonelists_init(void)
4385 __build_all_zonelists(NULL
);
4386 mminit_verify_zonelist();
4387 cpuset_init_current_mems_allowed();
4391 * Called with zonelists_mutex held always
4392 * unless system_state == SYSTEM_BOOTING.
4394 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4395 * [we're only called with non-NULL zone through __meminit paths] and
4396 * (2) call of __init annotated helper build_all_zonelists_init
4397 * [protected by SYSTEM_BOOTING].
4399 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
4401 set_zonelist_order();
4403 if (system_state
== SYSTEM_BOOTING
) {
4404 build_all_zonelists_init();
4406 #ifdef CONFIG_MEMORY_HOTPLUG
4408 setup_zone_pageset(zone
);
4410 /* we have to stop all cpus to guarantee there is no user
4412 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
4413 /* cpuset refresh routine should be here */
4415 vm_total_pages
= nr_free_pagecache_pages();
4417 * Disable grouping by mobility if the number of pages in the
4418 * system is too low to allow the mechanism to work. It would be
4419 * more accurate, but expensive to check per-zone. This check is
4420 * made on memory-hotadd so a system can start with mobility
4421 * disabled and enable it later
4423 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
4424 page_group_by_mobility_disabled
= 1;
4426 page_group_by_mobility_disabled
= 0;
4428 pr_info("Built %i zonelists in %s order, mobility grouping %s. "
4429 "Total pages: %ld\n",
4431 zonelist_order_name
[current_zonelist_order
],
4432 page_group_by_mobility_disabled
? "off" : "on",
4435 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
4440 * Helper functions to size the waitqueue hash table.
4441 * Essentially these want to choose hash table sizes sufficiently
4442 * large so that collisions trying to wait on pages are rare.
4443 * But in fact, the number of active page waitqueues on typical
4444 * systems is ridiculously low, less than 200. So this is even
4445 * conservative, even though it seems large.
4447 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
4448 * waitqueues, i.e. the size of the waitq table given the number of pages.
4450 #define PAGES_PER_WAITQUEUE 256
4452 #ifndef CONFIG_MEMORY_HOTPLUG
4453 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
4455 unsigned long size
= 1;
4457 pages
/= PAGES_PER_WAITQUEUE
;
4459 while (size
< pages
)
4463 * Once we have dozens or even hundreds of threads sleeping
4464 * on IO we've got bigger problems than wait queue collision.
4465 * Limit the size of the wait table to a reasonable size.
4467 size
= min(size
, 4096UL);
4469 return max(size
, 4UL);
4473 * A zone's size might be changed by hot-add, so it is not possible to determine
4474 * a suitable size for its wait_table. So we use the maximum size now.
4476 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
4478 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
4479 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
4480 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
4482 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
4483 * or more by the traditional way. (See above). It equals:
4485 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
4486 * ia64(16K page size) : = ( 8G + 4M)byte.
4487 * powerpc (64K page size) : = (32G +16M)byte.
4489 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
4496 * This is an integer logarithm so that shifts can be used later
4497 * to extract the more random high bits from the multiplicative
4498 * hash function before the remainder is taken.
4500 static inline unsigned long wait_table_bits(unsigned long size
)
4506 * Check if a pageblock contains reserved pages
4508 static int pageblock_is_reserved(unsigned long start_pfn
, unsigned long end_pfn
)
4512 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
4513 if (!pfn_valid_within(pfn
) || PageReserved(pfn_to_page(pfn
)))
4520 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
4521 * of blocks reserved is based on min_wmark_pages(zone). The memory within
4522 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
4523 * higher will lead to a bigger reserve which will get freed as contiguous
4524 * blocks as reclaim kicks in
4526 static void setup_zone_migrate_reserve(struct zone
*zone
)
4528 unsigned long start_pfn
, pfn
, end_pfn
, block_end_pfn
;
4530 unsigned long block_migratetype
;
4535 * Get the start pfn, end pfn and the number of blocks to reserve
4536 * We have to be careful to be aligned to pageblock_nr_pages to
4537 * make sure that we always check pfn_valid for the first page in
4540 start_pfn
= zone
->zone_start_pfn
;
4541 end_pfn
= zone_end_pfn(zone
);
4542 start_pfn
= roundup(start_pfn
, pageblock_nr_pages
);
4543 reserve
= roundup(min_wmark_pages(zone
), pageblock_nr_pages
) >>
4547 * Reserve blocks are generally in place to help high-order atomic
4548 * allocations that are short-lived. A min_free_kbytes value that
4549 * would result in more than 2 reserve blocks for atomic allocations
4550 * is assumed to be in place to help anti-fragmentation for the
4551 * future allocation of hugepages at runtime.
4553 reserve
= min(2, reserve
);
4554 old_reserve
= zone
->nr_migrate_reserve_block
;
4556 /* When memory hot-add, we almost always need to do nothing */
4557 if (reserve
== old_reserve
)
4559 zone
->nr_migrate_reserve_block
= reserve
;
4561 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
4562 if (!early_page_nid_uninitialised(pfn
, zone_to_nid(zone
)))
4565 if (!pfn_valid(pfn
))
4567 page
= pfn_to_page(pfn
);
4569 /* Watch out for overlapping nodes */
4570 if (page_to_nid(page
) != zone_to_nid(zone
))
4573 block_migratetype
= get_pageblock_migratetype(page
);
4575 /* Only test what is necessary when the reserves are not met */
4578 * Blocks with reserved pages will never free, skip
4581 block_end_pfn
= min(pfn
+ pageblock_nr_pages
, end_pfn
);
4582 if (pageblock_is_reserved(pfn
, block_end_pfn
))
4585 /* If this block is reserved, account for it */
4586 if (block_migratetype
== MIGRATE_RESERVE
) {
4591 /* Suitable for reserving if this block is movable */
4592 if (block_migratetype
== MIGRATE_MOVABLE
) {
4593 set_pageblock_migratetype(page
,
4595 move_freepages_block(zone
, page
,
4600 } else if (!old_reserve
) {
4602 * At boot time we don't need to scan the whole zone
4603 * for turning off MIGRATE_RESERVE.
4609 * If the reserve is met and this is a previous reserved block,
4612 if (block_migratetype
== MIGRATE_RESERVE
) {
4613 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4614 move_freepages_block(zone
, page
, MIGRATE_MOVABLE
);
4620 * Initially all pages are reserved - free ones are freed
4621 * up by free_all_bootmem() once the early boot process is
4622 * done. Non-atomic initialization, single-pass.
4624 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
4625 unsigned long start_pfn
, enum memmap_context context
)
4627 pg_data_t
*pgdat
= NODE_DATA(nid
);
4628 unsigned long end_pfn
= start_pfn
+ size
;
4631 unsigned long nr_initialised
= 0;
4633 if (highest_memmap_pfn
< end_pfn
- 1)
4634 highest_memmap_pfn
= end_pfn
- 1;
4636 z
= &pgdat
->node_zones
[zone
];
4637 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
4639 * There can be holes in boot-time mem_map[]s
4640 * handed to this function. They do not
4641 * exist on hotplugged memory.
4643 if (context
== MEMMAP_EARLY
) {
4644 if (!early_pfn_valid(pfn
))
4646 if (!early_pfn_in_nid(pfn
, nid
))
4648 if (!update_defer_init(pgdat
, pfn
, end_pfn
,
4654 * Mark the block movable so that blocks are reserved for
4655 * movable at startup. This will force kernel allocations
4656 * to reserve their blocks rather than leaking throughout
4657 * the address space during boot when many long-lived
4658 * kernel allocations are made. Later some blocks near
4659 * the start are marked MIGRATE_RESERVE by
4660 * setup_zone_migrate_reserve()
4662 * bitmap is created for zone's valid pfn range. but memmap
4663 * can be created for invalid pages (for alignment)
4664 * check here not to call set_pageblock_migratetype() against
4667 if (!(pfn
& (pageblock_nr_pages
- 1))) {
4668 struct page
*page
= pfn_to_page(pfn
);
4670 __init_single_page(page
, pfn
, zone
, nid
);
4671 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4673 __init_single_pfn(pfn
, zone
, nid
);
4678 static void __meminit
zone_init_free_lists(struct zone
*zone
)
4680 unsigned int order
, t
;
4681 for_each_migratetype_order(order
, t
) {
4682 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
4683 zone
->free_area
[order
].nr_free
= 0;
4687 #ifndef __HAVE_ARCH_MEMMAP_INIT
4688 #define memmap_init(size, nid, zone, start_pfn) \
4689 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4692 static int zone_batchsize(struct zone
*zone
)
4698 * The per-cpu-pages pools are set to around 1000th of the
4699 * size of the zone. But no more than 1/2 of a meg.
4701 * OK, so we don't know how big the cache is. So guess.
4703 batch
= zone
->managed_pages
/ 1024;
4704 if (batch
* PAGE_SIZE
> 512 * 1024)
4705 batch
= (512 * 1024) / PAGE_SIZE
;
4706 batch
/= 4; /* We effectively *= 4 below */
4711 * Clamp the batch to a 2^n - 1 value. Having a power
4712 * of 2 value was found to be more likely to have
4713 * suboptimal cache aliasing properties in some cases.
4715 * For example if 2 tasks are alternately allocating
4716 * batches of pages, one task can end up with a lot
4717 * of pages of one half of the possible page colors
4718 * and the other with pages of the other colors.
4720 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
4725 /* The deferral and batching of frees should be suppressed under NOMMU
4728 * The problem is that NOMMU needs to be able to allocate large chunks
4729 * of contiguous memory as there's no hardware page translation to
4730 * assemble apparent contiguous memory from discontiguous pages.
4732 * Queueing large contiguous runs of pages for batching, however,
4733 * causes the pages to actually be freed in smaller chunks. As there
4734 * can be a significant delay between the individual batches being
4735 * recycled, this leads to the once large chunks of space being
4736 * fragmented and becoming unavailable for high-order allocations.
4743 * pcp->high and pcp->batch values are related and dependent on one another:
4744 * ->batch must never be higher then ->high.
4745 * The following function updates them in a safe manner without read side
4748 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4749 * those fields changing asynchronously (acording the the above rule).
4751 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4752 * outside of boot time (or some other assurance that no concurrent updaters
4755 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
4756 unsigned long batch
)
4758 /* start with a fail safe value for batch */
4762 /* Update high, then batch, in order */
4769 /* a companion to pageset_set_high() */
4770 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
4772 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
4775 static void pageset_init(struct per_cpu_pageset
*p
)
4777 struct per_cpu_pages
*pcp
;
4780 memset(p
, 0, sizeof(*p
));
4784 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
4785 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
4788 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
4791 pageset_set_batch(p
, batch
);
4795 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4796 * to the value high for the pageset p.
4798 static void pageset_set_high(struct per_cpu_pageset
*p
,
4801 unsigned long batch
= max(1UL, high
/ 4);
4802 if ((high
/ 4) > (PAGE_SHIFT
* 8))
4803 batch
= PAGE_SHIFT
* 8;
4805 pageset_update(&p
->pcp
, high
, batch
);
4808 static void pageset_set_high_and_batch(struct zone
*zone
,
4809 struct per_cpu_pageset
*pcp
)
4811 if (percpu_pagelist_fraction
)
4812 pageset_set_high(pcp
,
4813 (zone
->managed_pages
/
4814 percpu_pagelist_fraction
));
4816 pageset_set_batch(pcp
, zone_batchsize(zone
));
4819 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
4821 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
4824 pageset_set_high_and_batch(zone
, pcp
);
4827 static void __meminit
setup_zone_pageset(struct zone
*zone
)
4830 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
4831 for_each_possible_cpu(cpu
)
4832 zone_pageset_init(zone
, cpu
);
4836 * Allocate per cpu pagesets and initialize them.
4837 * Before this call only boot pagesets were available.
4839 void __init
setup_per_cpu_pageset(void)
4843 for_each_populated_zone(zone
)
4844 setup_zone_pageset(zone
);
4847 static noinline __init_refok
4848 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
4854 * The per-page waitqueue mechanism uses hashed waitqueues
4857 zone
->wait_table_hash_nr_entries
=
4858 wait_table_hash_nr_entries(zone_size_pages
);
4859 zone
->wait_table_bits
=
4860 wait_table_bits(zone
->wait_table_hash_nr_entries
);
4861 alloc_size
= zone
->wait_table_hash_nr_entries
4862 * sizeof(wait_queue_head_t
);
4864 if (!slab_is_available()) {
4865 zone
->wait_table
= (wait_queue_head_t
*)
4866 memblock_virt_alloc_node_nopanic(
4867 alloc_size
, zone
->zone_pgdat
->node_id
);
4870 * This case means that a zone whose size was 0 gets new memory
4871 * via memory hot-add.
4872 * But it may be the case that a new node was hot-added. In
4873 * this case vmalloc() will not be able to use this new node's
4874 * memory - this wait_table must be initialized to use this new
4875 * node itself as well.
4876 * To use this new node's memory, further consideration will be
4879 zone
->wait_table
= vmalloc(alloc_size
);
4881 if (!zone
->wait_table
)
4884 for (i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
4885 init_waitqueue_head(zone
->wait_table
+ i
);
4890 static __meminit
void zone_pcp_init(struct zone
*zone
)
4893 * per cpu subsystem is not up at this point. The following code
4894 * relies on the ability of the linker to provide the
4895 * offset of a (static) per cpu variable into the per cpu area.
4897 zone
->pageset
= &boot_pageset
;
4899 if (populated_zone(zone
))
4900 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
4901 zone
->name
, zone
->present_pages
,
4902 zone_batchsize(zone
));
4905 int __meminit
init_currently_empty_zone(struct zone
*zone
,
4906 unsigned long zone_start_pfn
,
4909 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
4911 ret
= zone_wait_table_init(zone
, size
);
4914 pgdat
->nr_zones
= zone_idx(zone
) + 1;
4916 zone
->zone_start_pfn
= zone_start_pfn
;
4918 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
4919 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4921 (unsigned long)zone_idx(zone
),
4922 zone_start_pfn
, (zone_start_pfn
+ size
));
4924 zone_init_free_lists(zone
);
4929 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4930 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4933 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4935 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
4936 struct mminit_pfnnid_cache
*state
)
4938 unsigned long start_pfn
, end_pfn
;
4941 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
4942 return state
->last_nid
;
4944 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
4946 state
->last_start
= start_pfn
;
4947 state
->last_end
= end_pfn
;
4948 state
->last_nid
= nid
;
4953 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4956 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
4957 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4958 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
4960 * If an architecture guarantees that all ranges registered contain no holes
4961 * and may be freed, this this function may be used instead of calling
4962 * memblock_free_early_nid() manually.
4964 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
4966 unsigned long start_pfn
, end_pfn
;
4969 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
4970 start_pfn
= min(start_pfn
, max_low_pfn
);
4971 end_pfn
= min(end_pfn
, max_low_pfn
);
4973 if (start_pfn
< end_pfn
)
4974 memblock_free_early_nid(PFN_PHYS(start_pfn
),
4975 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
4981 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4982 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4984 * If an architecture guarantees that all ranges registered contain no holes and may
4985 * be freed, this function may be used instead of calling memory_present() manually.
4987 void __init
sparse_memory_present_with_active_regions(int nid
)
4989 unsigned long start_pfn
, end_pfn
;
4992 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
4993 memory_present(this_nid
, start_pfn
, end_pfn
);
4997 * get_pfn_range_for_nid - Return the start and end page frames for a node
4998 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4999 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
5000 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
5002 * It returns the start and end page frame of a node based on information
5003 * provided by memblock_set_node(). If called for a node
5004 * with no available memory, a warning is printed and the start and end
5007 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
5008 unsigned long *start_pfn
, unsigned long *end_pfn
)
5010 unsigned long this_start_pfn
, this_end_pfn
;
5016 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
5017 *start_pfn
= min(*start_pfn
, this_start_pfn
);
5018 *end_pfn
= max(*end_pfn
, this_end_pfn
);
5021 if (*start_pfn
== -1UL)
5026 * This finds a zone that can be used for ZONE_MOVABLE pages. The
5027 * assumption is made that zones within a node are ordered in monotonic
5028 * increasing memory addresses so that the "highest" populated zone is used
5030 static void __init
find_usable_zone_for_movable(void)
5033 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
5034 if (zone_index
== ZONE_MOVABLE
)
5037 if (arch_zone_highest_possible_pfn
[zone_index
] >
5038 arch_zone_lowest_possible_pfn
[zone_index
])
5042 VM_BUG_ON(zone_index
== -1);
5043 movable_zone
= zone_index
;
5047 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
5048 * because it is sized independent of architecture. Unlike the other zones,
5049 * the starting point for ZONE_MOVABLE is not fixed. It may be different
5050 * in each node depending on the size of each node and how evenly kernelcore
5051 * is distributed. This helper function adjusts the zone ranges
5052 * provided by the architecture for a given node by using the end of the
5053 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
5054 * zones within a node are in order of monotonic increases memory addresses
5056 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
5057 unsigned long zone_type
,
5058 unsigned long node_start_pfn
,
5059 unsigned long node_end_pfn
,
5060 unsigned long *zone_start_pfn
,
5061 unsigned long *zone_end_pfn
)
5063 /* Only adjust if ZONE_MOVABLE is on this node */
5064 if (zone_movable_pfn
[nid
]) {
5065 /* Size ZONE_MOVABLE */
5066 if (zone_type
== ZONE_MOVABLE
) {
5067 *zone_start_pfn
= zone_movable_pfn
[nid
];
5068 *zone_end_pfn
= min(node_end_pfn
,
5069 arch_zone_highest_possible_pfn
[movable_zone
]);
5071 /* Adjust for ZONE_MOVABLE starting within this range */
5072 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
5073 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
5074 *zone_end_pfn
= zone_movable_pfn
[nid
];
5076 /* Check if this whole range is within ZONE_MOVABLE */
5077 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
5078 *zone_start_pfn
= *zone_end_pfn
;
5083 * Return the number of pages a zone spans in a node, including holes
5084 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5086 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5087 unsigned long zone_type
,
5088 unsigned long node_start_pfn
,
5089 unsigned long node_end_pfn
,
5090 unsigned long *ignored
)
5092 unsigned long zone_start_pfn
, zone_end_pfn
;
5094 /* When hotadd a new node from cpu_up(), the node should be empty */
5095 if (!node_start_pfn
&& !node_end_pfn
)
5098 /* Get the start and end of the zone */
5099 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
5100 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
5101 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5102 node_start_pfn
, node_end_pfn
,
5103 &zone_start_pfn
, &zone_end_pfn
);
5105 /* Check that this node has pages within the zone's required range */
5106 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
5109 /* Move the zone boundaries inside the node if necessary */
5110 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
5111 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
5113 /* Return the spanned pages */
5114 return zone_end_pfn
- zone_start_pfn
;
5118 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5119 * then all holes in the requested range will be accounted for.
5121 unsigned long __meminit
__absent_pages_in_range(int nid
,
5122 unsigned long range_start_pfn
,
5123 unsigned long range_end_pfn
)
5125 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
5126 unsigned long start_pfn
, end_pfn
;
5129 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5130 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
5131 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
5132 nr_absent
-= end_pfn
- start_pfn
;
5138 * absent_pages_in_range - Return number of page frames in holes within a range
5139 * @start_pfn: The start PFN to start searching for holes
5140 * @end_pfn: The end PFN to stop searching for holes
5142 * It returns the number of pages frames in memory holes within a range.
5144 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
5145 unsigned long end_pfn
)
5147 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
5150 /* Return the number of page frames in holes in a zone on a node */
5151 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5152 unsigned long zone_type
,
5153 unsigned long node_start_pfn
,
5154 unsigned long node_end_pfn
,
5155 unsigned long *ignored
)
5157 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
5158 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
5159 unsigned long zone_start_pfn
, zone_end_pfn
;
5161 /* When hotadd a new node from cpu_up(), the node should be empty */
5162 if (!node_start_pfn
&& !node_end_pfn
)
5165 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
5166 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
5168 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5169 node_start_pfn
, node_end_pfn
,
5170 &zone_start_pfn
, &zone_end_pfn
);
5171 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
5174 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5175 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5176 unsigned long zone_type
,
5177 unsigned long node_start_pfn
,
5178 unsigned long node_end_pfn
,
5179 unsigned long *zones_size
)
5181 return zones_size
[zone_type
];
5184 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5185 unsigned long zone_type
,
5186 unsigned long node_start_pfn
,
5187 unsigned long node_end_pfn
,
5188 unsigned long *zholes_size
)
5193 return zholes_size
[zone_type
];
5196 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5198 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
5199 unsigned long node_start_pfn
,
5200 unsigned long node_end_pfn
,
5201 unsigned long *zones_size
,
5202 unsigned long *zholes_size
)
5204 unsigned long realtotalpages
= 0, totalpages
= 0;
5207 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5208 struct zone
*zone
= pgdat
->node_zones
+ i
;
5209 unsigned long size
, real_size
;
5211 size
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
5215 real_size
= size
- zone_absent_pages_in_node(pgdat
->node_id
, i
,
5216 node_start_pfn
, node_end_pfn
,
5218 zone
->spanned_pages
= size
;
5219 zone
->present_pages
= real_size
;
5222 realtotalpages
+= real_size
;
5225 pgdat
->node_spanned_pages
= totalpages
;
5226 pgdat
->node_present_pages
= realtotalpages
;
5227 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
5231 #ifndef CONFIG_SPARSEMEM
5233 * Calculate the size of the zone->blockflags rounded to an unsigned long
5234 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5235 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5236 * round what is now in bits to nearest long in bits, then return it in
5239 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
5241 unsigned long usemapsize
;
5243 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
5244 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
5245 usemapsize
= usemapsize
>> pageblock_order
;
5246 usemapsize
*= NR_PAGEBLOCK_BITS
;
5247 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
5249 return usemapsize
/ 8;
5252 static void __init
setup_usemap(struct pglist_data
*pgdat
,
5254 unsigned long zone_start_pfn
,
5255 unsigned long zonesize
)
5257 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
5258 zone
->pageblock_flags
= NULL
;
5260 zone
->pageblock_flags
=
5261 memblock_virt_alloc_node_nopanic(usemapsize
,
5265 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
5266 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
5267 #endif /* CONFIG_SPARSEMEM */
5269 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5271 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5272 void __paginginit
set_pageblock_order(void)
5276 /* Check that pageblock_nr_pages has not already been setup */
5277 if (pageblock_order
)
5280 if (HPAGE_SHIFT
> PAGE_SHIFT
)
5281 order
= HUGETLB_PAGE_ORDER
;
5283 order
= MAX_ORDER
- 1;
5286 * Assume the largest contiguous order of interest is a huge page.
5287 * This value may be variable depending on boot parameters on IA64 and
5290 pageblock_order
= order
;
5292 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5295 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5296 * is unused as pageblock_order is set at compile-time. See
5297 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5300 void __paginginit
set_pageblock_order(void)
5304 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5306 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
5307 unsigned long present_pages
)
5309 unsigned long pages
= spanned_pages
;
5312 * Provide a more accurate estimation if there are holes within
5313 * the zone and SPARSEMEM is in use. If there are holes within the
5314 * zone, each populated memory region may cost us one or two extra
5315 * memmap pages due to alignment because memmap pages for each
5316 * populated regions may not naturally algined on page boundary.
5317 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5319 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
5320 IS_ENABLED(CONFIG_SPARSEMEM
))
5321 pages
= present_pages
;
5323 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
5327 * Set up the zone data structures:
5328 * - mark all pages reserved
5329 * - mark all memory queues empty
5330 * - clear the memory bitmaps
5332 * NOTE: pgdat should get zeroed by caller.
5334 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
)
5337 int nid
= pgdat
->node_id
;
5338 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
5341 pgdat_resize_init(pgdat
);
5342 #ifdef CONFIG_NUMA_BALANCING
5343 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
5344 pgdat
->numabalancing_migrate_nr_pages
= 0;
5345 pgdat
->numabalancing_migrate_next_window
= jiffies
;
5347 init_waitqueue_head(&pgdat
->kswapd_wait
);
5348 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
5349 pgdat_page_ext_init(pgdat
);
5351 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5352 struct zone
*zone
= pgdat
->node_zones
+ j
;
5353 unsigned long size
, realsize
, freesize
, memmap_pages
;
5355 size
= zone
->spanned_pages
;
5356 realsize
= freesize
= zone
->present_pages
;
5359 * Adjust freesize so that it accounts for how much memory
5360 * is used by this zone for memmap. This affects the watermark
5361 * and per-cpu initialisations
5363 memmap_pages
= calc_memmap_size(size
, realsize
);
5364 if (!is_highmem_idx(j
)) {
5365 if (freesize
>= memmap_pages
) {
5366 freesize
-= memmap_pages
;
5369 " %s zone: %lu pages used for memmap\n",
5370 zone_names
[j
], memmap_pages
);
5373 " %s zone: %lu pages exceeds freesize %lu\n",
5374 zone_names
[j
], memmap_pages
, freesize
);
5377 /* Account for reserved pages */
5378 if (j
== 0 && freesize
> dma_reserve
) {
5379 freesize
-= dma_reserve
;
5380 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
5381 zone_names
[0], dma_reserve
);
5384 if (!is_highmem_idx(j
))
5385 nr_kernel_pages
+= freesize
;
5386 /* Charge for highmem memmap if there are enough kernel pages */
5387 else if (nr_kernel_pages
> memmap_pages
* 2)
5388 nr_kernel_pages
-= memmap_pages
;
5389 nr_all_pages
+= freesize
;
5392 * Set an approximate value for lowmem here, it will be adjusted
5393 * when the bootmem allocator frees pages into the buddy system.
5394 * And all highmem pages will be managed by the buddy system.
5396 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
5399 zone
->min_unmapped_pages
= (freesize
*sysctl_min_unmapped_ratio
)
5401 zone
->min_slab_pages
= (freesize
* sysctl_min_slab_ratio
) / 100;
5403 zone
->name
= zone_names
[j
];
5404 spin_lock_init(&zone
->lock
);
5405 spin_lock_init(&zone
->lru_lock
);
5406 zone_seqlock_init(zone
);
5407 zone
->zone_pgdat
= pgdat
;
5408 zone_pcp_init(zone
);
5410 /* For bootup, initialized properly in watermark setup */
5411 mod_zone_page_state(zone
, NR_ALLOC_BATCH
, zone
->managed_pages
);
5413 lruvec_init(&zone
->lruvec
);
5417 set_pageblock_order();
5418 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
5419 ret
= init_currently_empty_zone(zone
, zone_start_pfn
, size
);
5421 memmap_init(size
, nid
, j
, zone_start_pfn
);
5422 zone_start_pfn
+= size
;
5426 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
5428 unsigned long __maybe_unused offset
= 0;
5430 /* Skip empty nodes */
5431 if (!pgdat
->node_spanned_pages
)
5434 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5435 /* ia64 gets its own node_mem_map, before this, without bootmem */
5436 if (!pgdat
->node_mem_map
) {
5437 unsigned long size
, start
, end
;
5441 * The zone's endpoints aren't required to be MAX_ORDER
5442 * aligned but the node_mem_map endpoints must be in order
5443 * for the buddy allocator to function correctly.
5445 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
5446 offset
= pgdat
->node_start_pfn
- start
;
5447 end
= pgdat_end_pfn(pgdat
);
5448 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
5449 size
= (end
- start
) * sizeof(struct page
);
5450 map
= alloc_remap(pgdat
->node_id
, size
);
5452 map
= memblock_virt_alloc_node_nopanic(size
,
5454 pgdat
->node_mem_map
= map
+ offset
;
5456 #ifndef CONFIG_NEED_MULTIPLE_NODES
5458 * With no DISCONTIG, the global mem_map is just set as node 0's
5460 if (pgdat
== NODE_DATA(0)) {
5461 mem_map
= NODE_DATA(0)->node_mem_map
;
5462 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
5463 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
5465 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5468 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
5471 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
5472 unsigned long node_start_pfn
, unsigned long *zholes_size
)
5474 pg_data_t
*pgdat
= NODE_DATA(nid
);
5475 unsigned long start_pfn
= 0;
5476 unsigned long end_pfn
= 0;
5478 /* pg_data_t should be reset to zero when it's allocated */
5479 WARN_ON(pgdat
->nr_zones
|| pgdat
->classzone_idx
);
5481 reset_deferred_meminit(pgdat
);
5482 pgdat
->node_id
= nid
;
5483 pgdat
->node_start_pfn
= node_start_pfn
;
5484 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5485 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
5486 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
5487 (u64
)start_pfn
<< PAGE_SHIFT
,
5488 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
5490 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
5491 zones_size
, zholes_size
);
5493 alloc_node_mem_map(pgdat
);
5494 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5495 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
5496 nid
, (unsigned long)pgdat
,
5497 (unsigned long)pgdat
->node_mem_map
);
5500 free_area_init_core(pgdat
);
5503 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5505 #if MAX_NUMNODES > 1
5507 * Figure out the number of possible node ids.
5509 void __init
setup_nr_node_ids(void)
5511 unsigned int highest
;
5513 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
5514 nr_node_ids
= highest
+ 1;
5519 * node_map_pfn_alignment - determine the maximum internode alignment
5521 * This function should be called after node map is populated and sorted.
5522 * It calculates the maximum power of two alignment which can distinguish
5525 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5526 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5527 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5528 * shifted, 1GiB is enough and this function will indicate so.
5530 * This is used to test whether pfn -> nid mapping of the chosen memory
5531 * model has fine enough granularity to avoid incorrect mapping for the
5532 * populated node map.
5534 * Returns the determined alignment in pfn's. 0 if there is no alignment
5535 * requirement (single node).
5537 unsigned long __init
node_map_pfn_alignment(void)
5539 unsigned long accl_mask
= 0, last_end
= 0;
5540 unsigned long start
, end
, mask
;
5544 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
5545 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
5552 * Start with a mask granular enough to pin-point to the
5553 * start pfn and tick off bits one-by-one until it becomes
5554 * too coarse to separate the current node from the last.
5556 mask
= ~((1 << __ffs(start
)) - 1);
5557 while (mask
&& last_end
<= (start
& (mask
<< 1)))
5560 /* accumulate all internode masks */
5564 /* convert mask to number of pages */
5565 return ~accl_mask
+ 1;
5568 /* Find the lowest pfn for a node */
5569 static unsigned long __init
find_min_pfn_for_node(int nid
)
5571 unsigned long min_pfn
= ULONG_MAX
;
5572 unsigned long start_pfn
;
5575 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
5576 min_pfn
= min(min_pfn
, start_pfn
);
5578 if (min_pfn
== ULONG_MAX
) {
5580 "Could not find start_pfn for node %d\n", nid
);
5588 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5590 * It returns the minimum PFN based on information provided via
5591 * memblock_set_node().
5593 unsigned long __init
find_min_pfn_with_active_regions(void)
5595 return find_min_pfn_for_node(MAX_NUMNODES
);
5599 * early_calculate_totalpages()
5600 * Sum pages in active regions for movable zone.
5601 * Populate N_MEMORY for calculating usable_nodes.
5603 static unsigned long __init
early_calculate_totalpages(void)
5605 unsigned long totalpages
= 0;
5606 unsigned long start_pfn
, end_pfn
;
5609 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
5610 unsigned long pages
= end_pfn
- start_pfn
;
5612 totalpages
+= pages
;
5614 node_set_state(nid
, N_MEMORY
);
5620 * Find the PFN the Movable zone begins in each node. Kernel memory
5621 * is spread evenly between nodes as long as the nodes have enough
5622 * memory. When they don't, some nodes will have more kernelcore than
5625 static void __init
find_zone_movable_pfns_for_nodes(void)
5628 unsigned long usable_startpfn
;
5629 unsigned long kernelcore_node
, kernelcore_remaining
;
5630 /* save the state before borrow the nodemask */
5631 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
5632 unsigned long totalpages
= early_calculate_totalpages();
5633 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
5634 struct memblock_region
*r
;
5636 /* Need to find movable_zone earlier when movable_node is specified. */
5637 find_usable_zone_for_movable();
5640 * If movable_node is specified, ignore kernelcore and movablecore
5643 if (movable_node_is_enabled()) {
5644 for_each_memblock(memory
, r
) {
5645 if (!memblock_is_hotpluggable(r
))
5650 usable_startpfn
= PFN_DOWN(r
->base
);
5651 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
5652 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
5660 * If movablecore=nn[KMG] was specified, calculate what size of
5661 * kernelcore that corresponds so that memory usable for
5662 * any allocation type is evenly spread. If both kernelcore
5663 * and movablecore are specified, then the value of kernelcore
5664 * will be used for required_kernelcore if it's greater than
5665 * what movablecore would have allowed.
5667 if (required_movablecore
) {
5668 unsigned long corepages
;
5671 * Round-up so that ZONE_MOVABLE is at least as large as what
5672 * was requested by the user
5674 required_movablecore
=
5675 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
5676 required_movablecore
= min(totalpages
, required_movablecore
);
5677 corepages
= totalpages
- required_movablecore
;
5679 required_kernelcore
= max(required_kernelcore
, corepages
);
5683 * If kernelcore was not specified or kernelcore size is larger
5684 * than totalpages, there is no ZONE_MOVABLE.
5686 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
5689 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5690 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
5693 /* Spread kernelcore memory as evenly as possible throughout nodes */
5694 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5695 for_each_node_state(nid
, N_MEMORY
) {
5696 unsigned long start_pfn
, end_pfn
;
5699 * Recalculate kernelcore_node if the division per node
5700 * now exceeds what is necessary to satisfy the requested
5701 * amount of memory for the kernel
5703 if (required_kernelcore
< kernelcore_node
)
5704 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5707 * As the map is walked, we track how much memory is usable
5708 * by the kernel using kernelcore_remaining. When it is
5709 * 0, the rest of the node is usable by ZONE_MOVABLE
5711 kernelcore_remaining
= kernelcore_node
;
5713 /* Go through each range of PFNs within this node */
5714 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5715 unsigned long size_pages
;
5717 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
5718 if (start_pfn
>= end_pfn
)
5721 /* Account for what is only usable for kernelcore */
5722 if (start_pfn
< usable_startpfn
) {
5723 unsigned long kernel_pages
;
5724 kernel_pages
= min(end_pfn
, usable_startpfn
)
5727 kernelcore_remaining
-= min(kernel_pages
,
5728 kernelcore_remaining
);
5729 required_kernelcore
-= min(kernel_pages
,
5730 required_kernelcore
);
5732 /* Continue if range is now fully accounted */
5733 if (end_pfn
<= usable_startpfn
) {
5736 * Push zone_movable_pfn to the end so
5737 * that if we have to rebalance
5738 * kernelcore across nodes, we will
5739 * not double account here
5741 zone_movable_pfn
[nid
] = end_pfn
;
5744 start_pfn
= usable_startpfn
;
5748 * The usable PFN range for ZONE_MOVABLE is from
5749 * start_pfn->end_pfn. Calculate size_pages as the
5750 * number of pages used as kernelcore
5752 size_pages
= end_pfn
- start_pfn
;
5753 if (size_pages
> kernelcore_remaining
)
5754 size_pages
= kernelcore_remaining
;
5755 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
5758 * Some kernelcore has been met, update counts and
5759 * break if the kernelcore for this node has been
5762 required_kernelcore
-= min(required_kernelcore
,
5764 kernelcore_remaining
-= size_pages
;
5765 if (!kernelcore_remaining
)
5771 * If there is still required_kernelcore, we do another pass with one
5772 * less node in the count. This will push zone_movable_pfn[nid] further
5773 * along on the nodes that still have memory until kernelcore is
5777 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
5781 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5782 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
5783 zone_movable_pfn
[nid
] =
5784 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
5787 /* restore the node_state */
5788 node_states
[N_MEMORY
] = saved_node_state
;
5791 /* Any regular or high memory on that node ? */
5792 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
5794 enum zone_type zone_type
;
5796 if (N_MEMORY
== N_NORMAL_MEMORY
)
5799 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
5800 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
5801 if (populated_zone(zone
)) {
5802 node_set_state(nid
, N_HIGH_MEMORY
);
5803 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
5804 zone_type
<= ZONE_NORMAL
)
5805 node_set_state(nid
, N_NORMAL_MEMORY
);
5812 * free_area_init_nodes - Initialise all pg_data_t and zone data
5813 * @max_zone_pfn: an array of max PFNs for each zone
5815 * This will call free_area_init_node() for each active node in the system.
5816 * Using the page ranges provided by memblock_set_node(), the size of each
5817 * zone in each node and their holes is calculated. If the maximum PFN
5818 * between two adjacent zones match, it is assumed that the zone is empty.
5819 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5820 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5821 * starts where the previous one ended. For example, ZONE_DMA32 starts
5822 * at arch_max_dma_pfn.
5824 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
5826 unsigned long start_pfn
, end_pfn
;
5829 /* Record where the zone boundaries are */
5830 memset(arch_zone_lowest_possible_pfn
, 0,
5831 sizeof(arch_zone_lowest_possible_pfn
));
5832 memset(arch_zone_highest_possible_pfn
, 0,
5833 sizeof(arch_zone_highest_possible_pfn
));
5834 arch_zone_lowest_possible_pfn
[0] = find_min_pfn_with_active_regions();
5835 arch_zone_highest_possible_pfn
[0] = max_zone_pfn
[0];
5836 for (i
= 1; i
< MAX_NR_ZONES
; i
++) {
5837 if (i
== ZONE_MOVABLE
)
5839 arch_zone_lowest_possible_pfn
[i
] =
5840 arch_zone_highest_possible_pfn
[i
-1];
5841 arch_zone_highest_possible_pfn
[i
] =
5842 max(max_zone_pfn
[i
], arch_zone_lowest_possible_pfn
[i
]);
5844 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
5845 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
5847 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
5848 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
5849 find_zone_movable_pfns_for_nodes();
5851 /* Print out the zone ranges */
5852 pr_info("Zone ranges:\n");
5853 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5854 if (i
== ZONE_MOVABLE
)
5856 pr_info(" %-8s ", zone_names
[i
]);
5857 if (arch_zone_lowest_possible_pfn
[i
] ==
5858 arch_zone_highest_possible_pfn
[i
])
5861 pr_cont("[mem %#018Lx-%#018Lx]\n",
5862 (u64
)arch_zone_lowest_possible_pfn
[i
]
5864 ((u64
)arch_zone_highest_possible_pfn
[i
]
5865 << PAGE_SHIFT
) - 1);
5868 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5869 pr_info("Movable zone start for each node\n");
5870 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
5871 if (zone_movable_pfn
[i
])
5872 pr_info(" Node %d: %#018Lx\n", i
,
5873 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
5876 /* Print out the early node map */
5877 pr_info("Early memory node ranges\n");
5878 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
5879 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
5880 (u64
)start_pfn
<< PAGE_SHIFT
,
5881 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
5883 /* Initialise every node */
5884 mminit_verify_pageflags_layout();
5885 setup_nr_node_ids();
5886 for_each_online_node(nid
) {
5887 pg_data_t
*pgdat
= NODE_DATA(nid
);
5888 free_area_init_node(nid
, NULL
,
5889 find_min_pfn_for_node(nid
), NULL
);
5891 /* Any memory on that node */
5892 if (pgdat
->node_present_pages
)
5893 node_set_state(nid
, N_MEMORY
);
5894 check_for_memory(pgdat
, nid
);
5898 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
5900 unsigned long long coremem
;
5904 coremem
= memparse(p
, &p
);
5905 *core
= coremem
>> PAGE_SHIFT
;
5907 /* Paranoid check that UL is enough for the coremem value */
5908 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
5914 * kernelcore=size sets the amount of memory for use for allocations that
5915 * cannot be reclaimed or migrated.
5917 static int __init
cmdline_parse_kernelcore(char *p
)
5919 return cmdline_parse_core(p
, &required_kernelcore
);
5923 * movablecore=size sets the amount of memory for use for allocations that
5924 * can be reclaimed or migrated.
5926 static int __init
cmdline_parse_movablecore(char *p
)
5928 return cmdline_parse_core(p
, &required_movablecore
);
5931 early_param("kernelcore", cmdline_parse_kernelcore
);
5932 early_param("movablecore", cmdline_parse_movablecore
);
5934 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5936 void adjust_managed_page_count(struct page
*page
, long count
)
5938 spin_lock(&managed_page_count_lock
);
5939 page_zone(page
)->managed_pages
+= count
;
5940 totalram_pages
+= count
;
5941 #ifdef CONFIG_HIGHMEM
5942 if (PageHighMem(page
))
5943 totalhigh_pages
+= count
;
5945 spin_unlock(&managed_page_count_lock
);
5947 EXPORT_SYMBOL(adjust_managed_page_count
);
5949 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
5952 unsigned long pages
= 0;
5954 start
= (void *)PAGE_ALIGN((unsigned long)start
);
5955 end
= (void *)((unsigned long)end
& PAGE_MASK
);
5956 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
5957 if ((unsigned int)poison
<= 0xFF)
5958 memset(pos
, poison
, PAGE_SIZE
);
5959 free_reserved_page(virt_to_page(pos
));
5963 pr_info("Freeing %s memory: %ldK (%p - %p)\n",
5964 s
, pages
<< (PAGE_SHIFT
- 10), start
, end
);
5968 EXPORT_SYMBOL(free_reserved_area
);
5970 #ifdef CONFIG_HIGHMEM
5971 void free_highmem_page(struct page
*page
)
5973 __free_reserved_page(page
);
5975 page_zone(page
)->managed_pages
++;
5981 void __init
mem_init_print_info(const char *str
)
5983 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
5984 unsigned long init_code_size
, init_data_size
;
5986 physpages
= get_num_physpages();
5987 codesize
= _etext
- _stext
;
5988 datasize
= _edata
- _sdata
;
5989 rosize
= __end_rodata
- __start_rodata
;
5990 bss_size
= __bss_stop
- __bss_start
;
5991 init_data_size
= __init_end
- __init_begin
;
5992 init_code_size
= _einittext
- _sinittext
;
5995 * Detect special cases and adjust section sizes accordingly:
5996 * 1) .init.* may be embedded into .data sections
5997 * 2) .init.text.* may be out of [__init_begin, __init_end],
5998 * please refer to arch/tile/kernel/vmlinux.lds.S.
5999 * 3) .rodata.* may be embedded into .text or .data sections.
6001 #define adj_init_size(start, end, size, pos, adj) \
6003 if (start <= pos && pos < end && size > adj) \
6007 adj_init_size(__init_begin
, __init_end
, init_data_size
,
6008 _sinittext
, init_code_size
);
6009 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
6010 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
6011 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
6012 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
6014 #undef adj_init_size
6016 pr_info("Memory: %luK/%luK available "
6017 "(%luK kernel code, %luK rwdata, %luK rodata, "
6018 "%luK init, %luK bss, %luK reserved, %luK cma-reserved"
6019 #ifdef CONFIG_HIGHMEM
6023 nr_free_pages() << (PAGE_SHIFT
-10), physpages
<< (PAGE_SHIFT
-10),
6024 codesize
>> 10, datasize
>> 10, rosize
>> 10,
6025 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
6026 (physpages
- totalram_pages
- totalcma_pages
) << (PAGE_SHIFT
-10),
6027 totalcma_pages
<< (PAGE_SHIFT
-10),
6028 #ifdef CONFIG_HIGHMEM
6029 totalhigh_pages
<< (PAGE_SHIFT
-10),
6031 str
? ", " : "", str
? str
: "");
6035 * set_dma_reserve - set the specified number of pages reserved in the first zone
6036 * @new_dma_reserve: The number of pages to mark reserved
6038 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
6039 * In the DMA zone, a significant percentage may be consumed by kernel image
6040 * and other unfreeable allocations which can skew the watermarks badly. This
6041 * function may optionally be used to account for unfreeable pages in the
6042 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
6043 * smaller per-cpu batchsize.
6045 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
6047 dma_reserve
= new_dma_reserve
;
6050 void __init
free_area_init(unsigned long *zones_size
)
6052 free_area_init_node(0, zones_size
,
6053 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
6056 static int page_alloc_cpu_notify(struct notifier_block
*self
,
6057 unsigned long action
, void *hcpu
)
6059 int cpu
= (unsigned long)hcpu
;
6061 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
6062 lru_add_drain_cpu(cpu
);
6066 * Spill the event counters of the dead processor
6067 * into the current processors event counters.
6068 * This artificially elevates the count of the current
6071 vm_events_fold_cpu(cpu
);
6074 * Zero the differential counters of the dead processor
6075 * so that the vm statistics are consistent.
6077 * This is only okay since the processor is dead and cannot
6078 * race with what we are doing.
6080 cpu_vm_stats_fold(cpu
);
6085 void __init
page_alloc_init(void)
6087 hotcpu_notifier(page_alloc_cpu_notify
, 0);
6091 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6092 * or min_free_kbytes changes.
6094 static void calculate_totalreserve_pages(void)
6096 struct pglist_data
*pgdat
;
6097 unsigned long reserve_pages
= 0;
6098 enum zone_type i
, j
;
6100 for_each_online_pgdat(pgdat
) {
6101 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6102 struct zone
*zone
= pgdat
->node_zones
+ i
;
6105 /* Find valid and maximum lowmem_reserve in the zone */
6106 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
6107 if (zone
->lowmem_reserve
[j
] > max
)
6108 max
= zone
->lowmem_reserve
[j
];
6111 /* we treat the high watermark as reserved pages. */
6112 max
+= high_wmark_pages(zone
);
6114 if (max
> zone
->managed_pages
)
6115 max
= zone
->managed_pages
;
6116 reserve_pages
+= max
;
6118 * Lowmem reserves are not available to
6119 * GFP_HIGHUSER page cache allocations and
6120 * kswapd tries to balance zones to their high
6121 * watermark. As a result, neither should be
6122 * regarded as dirtyable memory, to prevent a
6123 * situation where reclaim has to clean pages
6124 * in order to balance the zones.
6126 zone
->dirty_balance_reserve
= max
;
6129 dirty_balance_reserve
= reserve_pages
;
6130 totalreserve_pages
= reserve_pages
;
6134 * setup_per_zone_lowmem_reserve - called whenever
6135 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6136 * has a correct pages reserved value, so an adequate number of
6137 * pages are left in the zone after a successful __alloc_pages().
6139 static void setup_per_zone_lowmem_reserve(void)
6141 struct pglist_data
*pgdat
;
6142 enum zone_type j
, idx
;
6144 for_each_online_pgdat(pgdat
) {
6145 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6146 struct zone
*zone
= pgdat
->node_zones
+ j
;
6147 unsigned long managed_pages
= zone
->managed_pages
;
6149 zone
->lowmem_reserve
[j
] = 0;
6153 struct zone
*lower_zone
;
6157 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
6158 sysctl_lowmem_reserve_ratio
[idx
] = 1;
6160 lower_zone
= pgdat
->node_zones
+ idx
;
6161 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
6162 sysctl_lowmem_reserve_ratio
[idx
];
6163 managed_pages
+= lower_zone
->managed_pages
;
6168 /* update totalreserve_pages */
6169 calculate_totalreserve_pages();
6172 static void __setup_per_zone_wmarks(void)
6174 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
6175 unsigned long lowmem_pages
= 0;
6177 unsigned long flags
;
6179 /* Calculate total number of !ZONE_HIGHMEM pages */
6180 for_each_zone(zone
) {
6181 if (!is_highmem(zone
))
6182 lowmem_pages
+= zone
->managed_pages
;
6185 for_each_zone(zone
) {
6188 spin_lock_irqsave(&zone
->lock
, flags
);
6189 tmp
= (u64
)pages_min
* zone
->managed_pages
;
6190 do_div(tmp
, lowmem_pages
);
6191 if (is_highmem(zone
)) {
6193 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6194 * need highmem pages, so cap pages_min to a small
6197 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6198 * deltas control asynch page reclaim, and so should
6199 * not be capped for highmem.
6201 unsigned long min_pages
;
6203 min_pages
= zone
->managed_pages
/ 1024;
6204 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
6205 zone
->watermark
[WMARK_MIN
] = min_pages
;
6208 * If it's a lowmem zone, reserve a number of pages
6209 * proportionate to the zone's size.
6211 zone
->watermark
[WMARK_MIN
] = tmp
;
6214 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) + (tmp
>> 2);
6215 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) + (tmp
>> 1);
6217 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
6218 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
6219 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
6221 setup_zone_migrate_reserve(zone
);
6222 spin_unlock_irqrestore(&zone
->lock
, flags
);
6225 /* update totalreserve_pages */
6226 calculate_totalreserve_pages();
6230 * setup_per_zone_wmarks - called when min_free_kbytes changes
6231 * or when memory is hot-{added|removed}
6233 * Ensures that the watermark[min,low,high] values for each zone are set
6234 * correctly with respect to min_free_kbytes.
6236 void setup_per_zone_wmarks(void)
6238 mutex_lock(&zonelists_mutex
);
6239 __setup_per_zone_wmarks();
6240 mutex_unlock(&zonelists_mutex
);
6244 * The inactive anon list should be small enough that the VM never has to
6245 * do too much work, but large enough that each inactive page has a chance
6246 * to be referenced again before it is swapped out.
6248 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
6249 * INACTIVE_ANON pages on this zone's LRU, maintained by the
6250 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
6251 * the anonymous pages are kept on the inactive list.
6254 * memory ratio inactive anon
6255 * -------------------------------------
6264 static void __meminit
calculate_zone_inactive_ratio(struct zone
*zone
)
6266 unsigned int gb
, ratio
;
6268 /* Zone size in gigabytes */
6269 gb
= zone
->managed_pages
>> (30 - PAGE_SHIFT
);
6271 ratio
= int_sqrt(10 * gb
);
6275 zone
->inactive_ratio
= ratio
;
6278 static void __meminit
setup_per_zone_inactive_ratio(void)
6283 calculate_zone_inactive_ratio(zone
);
6287 * Initialise min_free_kbytes.
6289 * For small machines we want it small (128k min). For large machines
6290 * we want it large (64MB max). But it is not linear, because network
6291 * bandwidth does not increase linearly with machine size. We use
6293 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6294 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6310 int __meminit
init_per_zone_wmark_min(void)
6312 unsigned long lowmem_kbytes
;
6313 int new_min_free_kbytes
;
6315 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
6316 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
6318 if (new_min_free_kbytes
> user_min_free_kbytes
) {
6319 min_free_kbytes
= new_min_free_kbytes
;
6320 if (min_free_kbytes
< 128)
6321 min_free_kbytes
= 128;
6322 if (min_free_kbytes
> 65536)
6323 min_free_kbytes
= 65536;
6325 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6326 new_min_free_kbytes
, user_min_free_kbytes
);
6328 setup_per_zone_wmarks();
6329 refresh_zone_stat_thresholds();
6330 setup_per_zone_lowmem_reserve();
6331 setup_per_zone_inactive_ratio();
6334 module_init(init_per_zone_wmark_min
)
6337 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6338 * that we can call two helper functions whenever min_free_kbytes
6341 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
6342 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6346 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6351 user_min_free_kbytes
= min_free_kbytes
;
6352 setup_per_zone_wmarks();
6358 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6359 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6364 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6369 zone
->min_unmapped_pages
= (zone
->managed_pages
*
6370 sysctl_min_unmapped_ratio
) / 100;
6374 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6375 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6380 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6385 zone
->min_slab_pages
= (zone
->managed_pages
*
6386 sysctl_min_slab_ratio
) / 100;
6392 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6393 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6394 * whenever sysctl_lowmem_reserve_ratio changes.
6396 * The reserve ratio obviously has absolutely no relation with the
6397 * minimum watermarks. The lowmem reserve ratio can only make sense
6398 * if in function of the boot time zone sizes.
6400 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6401 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6403 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6404 setup_per_zone_lowmem_reserve();
6409 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6410 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6411 * pagelist can have before it gets flushed back to buddy allocator.
6413 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
6414 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6417 int old_percpu_pagelist_fraction
;
6420 mutex_lock(&pcp_batch_high_lock
);
6421 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
6423 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6424 if (!write
|| ret
< 0)
6427 /* Sanity checking to avoid pcp imbalance */
6428 if (percpu_pagelist_fraction
&&
6429 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
6430 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
6436 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
6439 for_each_populated_zone(zone
) {
6442 for_each_possible_cpu(cpu
)
6443 pageset_set_high_and_batch(zone
,
6444 per_cpu_ptr(zone
->pageset
, cpu
));
6447 mutex_unlock(&pcp_batch_high_lock
);
6452 int hashdist
= HASHDIST_DEFAULT
;
6454 static int __init
set_hashdist(char *str
)
6458 hashdist
= simple_strtoul(str
, &str
, 0);
6461 __setup("hashdist=", set_hashdist
);
6465 * allocate a large system hash table from bootmem
6466 * - it is assumed that the hash table must contain an exact power-of-2
6467 * quantity of entries
6468 * - limit is the number of hash buckets, not the total allocation size
6470 void *__init
alloc_large_system_hash(const char *tablename
,
6471 unsigned long bucketsize
,
6472 unsigned long numentries
,
6475 unsigned int *_hash_shift
,
6476 unsigned int *_hash_mask
,
6477 unsigned long low_limit
,
6478 unsigned long high_limit
)
6480 unsigned long long max
= high_limit
;
6481 unsigned long log2qty
, size
;
6484 /* allow the kernel cmdline to have a say */
6486 /* round applicable memory size up to nearest megabyte */
6487 numentries
= nr_kernel_pages
;
6489 /* It isn't necessary when PAGE_SIZE >= 1MB */
6490 if (PAGE_SHIFT
< 20)
6491 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
6493 /* limit to 1 bucket per 2^scale bytes of low memory */
6494 if (scale
> PAGE_SHIFT
)
6495 numentries
>>= (scale
- PAGE_SHIFT
);
6497 numentries
<<= (PAGE_SHIFT
- scale
);
6499 /* Make sure we've got at least a 0-order allocation.. */
6500 if (unlikely(flags
& HASH_SMALL
)) {
6501 /* Makes no sense without HASH_EARLY */
6502 WARN_ON(!(flags
& HASH_EARLY
));
6503 if (!(numentries
>> *_hash_shift
)) {
6504 numentries
= 1UL << *_hash_shift
;
6505 BUG_ON(!numentries
);
6507 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
6508 numentries
= PAGE_SIZE
/ bucketsize
;
6510 numentries
= roundup_pow_of_two(numentries
);
6512 /* limit allocation size to 1/16 total memory by default */
6514 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
6515 do_div(max
, bucketsize
);
6517 max
= min(max
, 0x80000000ULL
);
6519 if (numentries
< low_limit
)
6520 numentries
= low_limit
;
6521 if (numentries
> max
)
6524 log2qty
= ilog2(numentries
);
6527 size
= bucketsize
<< log2qty
;
6528 if (flags
& HASH_EARLY
)
6529 table
= memblock_virt_alloc_nopanic(size
, 0);
6531 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
6534 * If bucketsize is not a power-of-two, we may free
6535 * some pages at the end of hash table which
6536 * alloc_pages_exact() automatically does
6538 if (get_order(size
) < MAX_ORDER
) {
6539 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
6540 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
6543 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
6546 panic("Failed to allocate %s hash table\n", tablename
);
6548 printk(KERN_INFO
"%s hash table entries: %ld (order: %d, %lu bytes)\n",
6551 ilog2(size
) - PAGE_SHIFT
,
6555 *_hash_shift
= log2qty
;
6557 *_hash_mask
= (1 << log2qty
) - 1;
6562 /* Return a pointer to the bitmap storing bits affecting a block of pages */
6563 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
6566 #ifdef CONFIG_SPARSEMEM
6567 return __pfn_to_section(pfn
)->pageblock_flags
;
6569 return zone
->pageblock_flags
;
6570 #endif /* CONFIG_SPARSEMEM */
6573 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
6575 #ifdef CONFIG_SPARSEMEM
6576 pfn
&= (PAGES_PER_SECTION
-1);
6577 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6579 pfn
= pfn
- round_down(zone
->zone_start_pfn
, pageblock_nr_pages
);
6580 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6581 #endif /* CONFIG_SPARSEMEM */
6585 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
6586 * @page: The page within the block of interest
6587 * @pfn: The target page frame number
6588 * @end_bitidx: The last bit of interest to retrieve
6589 * @mask: mask of bits that the caller is interested in
6591 * Return: pageblock_bits flags
6593 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
6594 unsigned long end_bitidx
,
6598 unsigned long *bitmap
;
6599 unsigned long bitidx
, word_bitidx
;
6602 zone
= page_zone(page
);
6603 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6604 bitidx
= pfn_to_bitidx(zone
, pfn
);
6605 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6606 bitidx
&= (BITS_PER_LONG
-1);
6608 word
= bitmap
[word_bitidx
];
6609 bitidx
+= end_bitidx
;
6610 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
6614 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
6615 * @page: The page within the block of interest
6616 * @flags: The flags to set
6617 * @pfn: The target page frame number
6618 * @end_bitidx: The last bit of interest
6619 * @mask: mask of bits that the caller is interested in
6621 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
6623 unsigned long end_bitidx
,
6627 unsigned long *bitmap
;
6628 unsigned long bitidx
, word_bitidx
;
6629 unsigned long old_word
, word
;
6631 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
6633 zone
= page_zone(page
);
6634 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6635 bitidx
= pfn_to_bitidx(zone
, pfn
);
6636 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6637 bitidx
&= (BITS_PER_LONG
-1);
6639 VM_BUG_ON_PAGE(!zone_spans_pfn(zone
, pfn
), page
);
6641 bitidx
+= end_bitidx
;
6642 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
6643 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
6645 word
= READ_ONCE(bitmap
[word_bitidx
]);
6647 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
6648 if (word
== old_word
)
6655 * This function checks whether pageblock includes unmovable pages or not.
6656 * If @count is not zero, it is okay to include less @count unmovable pages
6658 * PageLRU check without isolation or lru_lock could race so that
6659 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6660 * expect this function should be exact.
6662 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
6663 bool skip_hwpoisoned_pages
)
6665 unsigned long pfn
, iter
, found
;
6669 * For avoiding noise data, lru_add_drain_all() should be called
6670 * If ZONE_MOVABLE, the zone never contains unmovable pages
6672 if (zone_idx(zone
) == ZONE_MOVABLE
)
6674 mt
= get_pageblock_migratetype(page
);
6675 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
6678 pfn
= page_to_pfn(page
);
6679 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
6680 unsigned long check
= pfn
+ iter
;
6682 if (!pfn_valid_within(check
))
6685 page
= pfn_to_page(check
);
6688 * Hugepages are not in LRU lists, but they're movable.
6689 * We need not scan over tail pages bacause we don't
6690 * handle each tail page individually in migration.
6692 if (PageHuge(page
)) {
6693 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
6698 * We can't use page_count without pin a page
6699 * because another CPU can free compound page.
6700 * This check already skips compound tails of THP
6701 * because their page->_count is zero at all time.
6703 if (!atomic_read(&page
->_count
)) {
6704 if (PageBuddy(page
))
6705 iter
+= (1 << page_order(page
)) - 1;
6710 * The HWPoisoned page may be not in buddy system, and
6711 * page_count() is not 0.
6713 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
6719 * If there are RECLAIMABLE pages, we need to check
6720 * it. But now, memory offline itself doesn't call
6721 * shrink_node_slabs() and it still to be fixed.
6724 * If the page is not RAM, page_count()should be 0.
6725 * we don't need more check. This is an _used_ not-movable page.
6727 * The problematic thing here is PG_reserved pages. PG_reserved
6728 * is set to both of a memory hole page and a _used_ kernel
6737 bool is_pageblock_removable_nolock(struct page
*page
)
6743 * We have to be careful here because we are iterating over memory
6744 * sections which are not zone aware so we might end up outside of
6745 * the zone but still within the section.
6746 * We have to take care about the node as well. If the node is offline
6747 * its NODE_DATA will be NULL - see page_zone.
6749 if (!node_online(page_to_nid(page
)))
6752 zone
= page_zone(page
);
6753 pfn
= page_to_pfn(page
);
6754 if (!zone_spans_pfn(zone
, pfn
))
6757 return !has_unmovable_pages(zone
, page
, 0, true);
6762 static unsigned long pfn_max_align_down(unsigned long pfn
)
6764 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6765 pageblock_nr_pages
) - 1);
6768 static unsigned long pfn_max_align_up(unsigned long pfn
)
6770 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6771 pageblock_nr_pages
));
6774 /* [start, end) must belong to a single zone. */
6775 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
6776 unsigned long start
, unsigned long end
)
6778 /* This function is based on compact_zone() from compaction.c. */
6779 unsigned long nr_reclaimed
;
6780 unsigned long pfn
= start
;
6781 unsigned int tries
= 0;
6786 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
6787 if (fatal_signal_pending(current
)) {
6792 if (list_empty(&cc
->migratepages
)) {
6793 cc
->nr_migratepages
= 0;
6794 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
6800 } else if (++tries
== 5) {
6801 ret
= ret
< 0 ? ret
: -EBUSY
;
6805 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
6807 cc
->nr_migratepages
-= nr_reclaimed
;
6809 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
6810 NULL
, 0, cc
->mode
, MR_CMA
);
6813 putback_movable_pages(&cc
->migratepages
);
6820 * alloc_contig_range() -- tries to allocate given range of pages
6821 * @start: start PFN to allocate
6822 * @end: one-past-the-last PFN to allocate
6823 * @migratetype: migratetype of the underlaying pageblocks (either
6824 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
6825 * in range must have the same migratetype and it must
6826 * be either of the two.
6828 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
6829 * aligned, however it's the caller's responsibility to guarantee that
6830 * we are the only thread that changes migrate type of pageblocks the
6833 * The PFN range must belong to a single zone.
6835 * Returns zero on success or negative error code. On success all
6836 * pages which PFN is in [start, end) are allocated for the caller and
6837 * need to be freed with free_contig_range().
6839 int alloc_contig_range(unsigned long start
, unsigned long end
,
6840 unsigned migratetype
)
6842 unsigned long outer_start
, outer_end
;
6845 struct compact_control cc
= {
6846 .nr_migratepages
= 0,
6848 .zone
= page_zone(pfn_to_page(start
)),
6849 .mode
= MIGRATE_SYNC
,
6850 .ignore_skip_hint
= true,
6852 INIT_LIST_HEAD(&cc
.migratepages
);
6855 * What we do here is we mark all pageblocks in range as
6856 * MIGRATE_ISOLATE. Because pageblock and max order pages may
6857 * have different sizes, and due to the way page allocator
6858 * work, we align the range to biggest of the two pages so
6859 * that page allocator won't try to merge buddies from
6860 * different pageblocks and change MIGRATE_ISOLATE to some
6861 * other migration type.
6863 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
6864 * migrate the pages from an unaligned range (ie. pages that
6865 * we are interested in). This will put all the pages in
6866 * range back to page allocator as MIGRATE_ISOLATE.
6868 * When this is done, we take the pages in range from page
6869 * allocator removing them from the buddy system. This way
6870 * page allocator will never consider using them.
6872 * This lets us mark the pageblocks back as
6873 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
6874 * aligned range but not in the unaligned, original range are
6875 * put back to page allocator so that buddy can use them.
6878 ret
= start_isolate_page_range(pfn_max_align_down(start
),
6879 pfn_max_align_up(end
), migratetype
,
6884 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
6889 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
6890 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
6891 * more, all pages in [start, end) are free in page allocator.
6892 * What we are going to do is to allocate all pages from
6893 * [start, end) (that is remove them from page allocator).
6895 * The only problem is that pages at the beginning and at the
6896 * end of interesting range may be not aligned with pages that
6897 * page allocator holds, ie. they can be part of higher order
6898 * pages. Because of this, we reserve the bigger range and
6899 * once this is done free the pages we are not interested in.
6901 * We don't have to hold zone->lock here because the pages are
6902 * isolated thus they won't get removed from buddy.
6905 lru_add_drain_all();
6906 drain_all_pages(cc
.zone
);
6909 outer_start
= start
;
6910 while (!PageBuddy(pfn_to_page(outer_start
))) {
6911 if (++order
>= MAX_ORDER
) {
6915 outer_start
&= ~0UL << order
;
6918 /* Make sure the range is really isolated. */
6919 if (test_pages_isolated(outer_start
, end
, false)) {
6920 pr_info("%s: [%lx, %lx) PFNs busy\n",
6921 __func__
, outer_start
, end
);
6926 /* Grab isolated pages from freelists. */
6927 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
6933 /* Free head and tail (if any) */
6934 if (start
!= outer_start
)
6935 free_contig_range(outer_start
, start
- outer_start
);
6936 if (end
!= outer_end
)
6937 free_contig_range(end
, outer_end
- end
);
6940 undo_isolate_page_range(pfn_max_align_down(start
),
6941 pfn_max_align_up(end
), migratetype
);
6945 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
6947 unsigned int count
= 0;
6949 for (; nr_pages
--; pfn
++) {
6950 struct page
*page
= pfn_to_page(pfn
);
6952 count
+= page_count(page
) != 1;
6955 WARN(count
!= 0, "%d pages are still in use!\n", count
);
6959 #ifdef CONFIG_MEMORY_HOTPLUG
6961 * The zone indicated has a new number of managed_pages; batch sizes and percpu
6962 * page high values need to be recalulated.
6964 void __meminit
zone_pcp_update(struct zone
*zone
)
6967 mutex_lock(&pcp_batch_high_lock
);
6968 for_each_possible_cpu(cpu
)
6969 pageset_set_high_and_batch(zone
,
6970 per_cpu_ptr(zone
->pageset
, cpu
));
6971 mutex_unlock(&pcp_batch_high_lock
);
6975 void zone_pcp_reset(struct zone
*zone
)
6977 unsigned long flags
;
6979 struct per_cpu_pageset
*pset
;
6981 /* avoid races with drain_pages() */
6982 local_irq_save(flags
);
6983 if (zone
->pageset
!= &boot_pageset
) {
6984 for_each_online_cpu(cpu
) {
6985 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
6986 drain_zonestat(zone
, pset
);
6988 free_percpu(zone
->pageset
);
6989 zone
->pageset
= &boot_pageset
;
6991 local_irq_restore(flags
);
6994 #ifdef CONFIG_MEMORY_HOTREMOVE
6996 * All pages in the range must be isolated before calling this.
6999 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
7003 unsigned int order
, i
;
7005 unsigned long flags
;
7006 /* find the first valid pfn */
7007 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
7012 zone
= page_zone(pfn_to_page(pfn
));
7013 spin_lock_irqsave(&zone
->lock
, flags
);
7015 while (pfn
< end_pfn
) {
7016 if (!pfn_valid(pfn
)) {
7020 page
= pfn_to_page(pfn
);
7022 * The HWPoisoned page may be not in buddy system, and
7023 * page_count() is not 0.
7025 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
7027 SetPageReserved(page
);
7031 BUG_ON(page_count(page
));
7032 BUG_ON(!PageBuddy(page
));
7033 order
= page_order(page
);
7034 #ifdef CONFIG_DEBUG_VM
7035 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
7036 pfn
, 1 << order
, end_pfn
);
7038 list_del(&page
->lru
);
7039 rmv_page_order(page
);
7040 zone
->free_area
[order
].nr_free
--;
7041 for (i
= 0; i
< (1 << order
); i
++)
7042 SetPageReserved((page
+i
));
7043 pfn
+= (1 << order
);
7045 spin_unlock_irqrestore(&zone
->lock
, flags
);
7049 #ifdef CONFIG_MEMORY_FAILURE
7050 bool is_free_buddy_page(struct page
*page
)
7052 struct zone
*zone
= page_zone(page
);
7053 unsigned long pfn
= page_to_pfn(page
);
7054 unsigned long flags
;
7057 spin_lock_irqsave(&zone
->lock
, flags
);
7058 for (order
= 0; order
< MAX_ORDER
; order
++) {
7059 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
7061 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
7064 spin_unlock_irqrestore(&zone
->lock
, flags
);
7066 return order
< MAX_ORDER
;