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_IO
| __GFP_FS
);
175 bool pm_suspended_storage(void)
177 if ((gfp_allowed_mask
& (__GFP_IO
| __GFP_FS
)) == (__GFP_IO
| __GFP_FS
))
181 #endif /* CONFIG_PM_SLEEP */
183 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
184 unsigned 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 static void free_compound_page(struct page
*page
);
233 compound_page_dtor
* const compound_page_dtors
[] = {
236 #ifdef CONFIG_HUGETLB_PAGE
242 * Try to keep at least this much lowmem free. Do not allow normal
243 * allocations below this point, only high priority ones. Automatically
244 * tuned according to the amount of memory in the system.
246 int min_free_kbytes
= 1024;
247 int user_min_free_kbytes
= -1;
250 * Extra memory for the system to try freeing. Used to temporarily
251 * free memory, to make space for new workloads. Anyone can allocate
252 * down to the min watermarks controlled by min_free_kbytes above.
254 int extra_free_kbytes
= 0;
256 static unsigned long __meminitdata nr_kernel_pages
;
257 static unsigned long __meminitdata nr_all_pages
;
258 static unsigned long __meminitdata dma_reserve
;
260 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
261 static unsigned long __meminitdata arch_zone_lowest_possible_pfn
[MAX_NR_ZONES
];
262 static unsigned long __meminitdata arch_zone_highest_possible_pfn
[MAX_NR_ZONES
];
263 static unsigned long __initdata required_kernelcore
;
264 static unsigned long __initdata required_movablecore
;
265 static unsigned long __meminitdata zone_movable_pfn
[MAX_NUMNODES
];
267 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
269 EXPORT_SYMBOL(movable_zone
);
270 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
273 int nr_node_ids __read_mostly
= MAX_NUMNODES
;
274 int nr_online_nodes __read_mostly
= 1;
275 EXPORT_SYMBOL(nr_node_ids
);
276 EXPORT_SYMBOL(nr_online_nodes
);
279 int page_group_by_mobility_disabled __read_mostly
;
281 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
284 * Determine how many pages need to be initialized durig early boot
285 * (non-deferred initialization).
286 * The value of first_deferred_pfn will be set later, once non-deferred pages
287 * are initialized, but for now set it ULONG_MAX.
289 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
291 phys_addr_t start_addr
, end_addr
;
292 unsigned long max_pgcnt
;
293 unsigned long reserved
;
296 * Initialise at least 2G of a node but also take into account that
297 * two large system hashes that can take up 1GB for 0.25TB/node.
299 max_pgcnt
= max(2UL << (30 - PAGE_SHIFT
),
300 (pgdat
->node_spanned_pages
>> 8));
303 * Compensate the all the memblock reservations (e.g. crash kernel)
304 * from the initial estimation to make sure we will initialize enough
307 start_addr
= PFN_PHYS(pgdat
->node_start_pfn
);
308 end_addr
= PFN_PHYS(pgdat
->node_start_pfn
+ max_pgcnt
);
309 reserved
= memblock_reserved_memory_within(start_addr
, end_addr
);
310 max_pgcnt
+= PHYS_PFN(reserved
);
312 pgdat
->static_init_pgcnt
= min(max_pgcnt
, pgdat
->node_spanned_pages
);
313 pgdat
->first_deferred_pfn
= ULONG_MAX
;
316 /* Returns true if the struct page for the pfn is uninitialised */
317 static inline bool __meminit
early_page_uninitialised(unsigned long pfn
)
319 int nid
= early_pfn_to_nid(pfn
);
321 if (node_online(nid
) && pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
327 static inline bool early_page_nid_uninitialised(unsigned long pfn
, int nid
)
329 if (pfn
>= NODE_DATA(nid
)->first_deferred_pfn
)
336 * Returns false when the remaining initialisation should be deferred until
337 * later in the boot cycle when it can be parallelised.
339 static inline bool update_defer_init(pg_data_t
*pgdat
,
340 unsigned long pfn
, unsigned long zone_end
,
341 unsigned long *nr_initialised
)
343 /* Always populate low zones for address-contrained allocations */
344 if (zone_end
< pgdat_end_pfn(pgdat
))
346 /* Initialise at least 2G of the highest zone */
348 if ((*nr_initialised
> pgdat
->static_init_pgcnt
) &&
349 (pfn
& (PAGES_PER_SECTION
- 1)) == 0) {
350 pgdat
->first_deferred_pfn
= pfn
;
357 static inline void reset_deferred_meminit(pg_data_t
*pgdat
)
361 static inline bool early_page_uninitialised(unsigned long pfn
)
366 static inline bool early_page_nid_uninitialised(unsigned long pfn
, int nid
)
371 static inline bool update_defer_init(pg_data_t
*pgdat
,
372 unsigned long pfn
, unsigned long zone_end
,
373 unsigned long *nr_initialised
)
380 void set_pageblock_migratetype(struct page
*page
, int migratetype
)
382 if (unlikely(page_group_by_mobility_disabled
&&
383 migratetype
< MIGRATE_PCPTYPES
))
384 migratetype
= MIGRATE_UNMOVABLE
;
386 set_pageblock_flags_group(page
, (unsigned long)migratetype
,
387 PB_migrate
, PB_migrate_end
);
390 #ifdef CONFIG_DEBUG_VM
391 static int page_outside_zone_boundaries(struct zone
*zone
, struct page
*page
)
395 unsigned long pfn
= page_to_pfn(page
);
396 unsigned long sp
, start_pfn
;
399 seq
= zone_span_seqbegin(zone
);
400 start_pfn
= zone
->zone_start_pfn
;
401 sp
= zone
->spanned_pages
;
402 if (!zone_spans_pfn(zone
, pfn
))
404 } while (zone_span_seqretry(zone
, seq
));
407 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n",
408 pfn
, zone_to_nid(zone
), zone
->name
,
409 start_pfn
, start_pfn
+ sp
);
414 static int page_is_consistent(struct zone
*zone
, struct page
*page
)
416 if (!pfn_valid_within(page_to_pfn(page
)))
418 if (zone
!= page_zone(page
))
424 * Temporary debugging check for pages not lying within a given zone.
426 static int bad_range(struct zone
*zone
, struct page
*page
)
428 if (page_outside_zone_boundaries(zone
, page
))
430 if (!page_is_consistent(zone
, page
))
436 static inline int bad_range(struct zone
*zone
, struct page
*page
)
442 static void bad_page(struct page
*page
, const char *reason
,
443 unsigned long bad_flags
)
445 static unsigned long resume
;
446 static unsigned long nr_shown
;
447 static unsigned long nr_unshown
;
449 /* Don't complain about poisoned pages */
450 if (PageHWPoison(page
)) {
451 page_mapcount_reset(page
); /* remove PageBuddy */
456 * Allow a burst of 60 reports, then keep quiet for that minute;
457 * or allow a steady drip of one report per second.
459 if (nr_shown
== 60) {
460 if (time_before(jiffies
, resume
)) {
466 "BUG: Bad page state: %lu messages suppressed\n",
473 resume
= jiffies
+ 60 * HZ
;
475 printk(KERN_ALERT
"BUG: Bad page state in process %s pfn:%05lx\n",
476 current
->comm
, page_to_pfn(page
));
477 dump_page_badflags(page
, reason
, bad_flags
);
482 /* Leave bad fields for debug, except PageBuddy could make trouble */
483 page_mapcount_reset(page
); /* remove PageBuddy */
484 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
488 * Higher-order pages are called "compound pages". They are structured thusly:
490 * The first PAGE_SIZE page is called the "head page" and have PG_head set.
492 * The remaining PAGE_SIZE pages are called "tail pages". PageTail() is encoded
493 * in bit 0 of page->compound_head. The rest of bits is pointer to head page.
495 * The first tail page's ->compound_dtor holds the offset in array of compound
496 * page destructors. See compound_page_dtors.
498 * The first tail page's ->compound_order holds the order of allocation.
499 * This usage means that zero-order pages may not be compound.
502 static void free_compound_page(struct page
*page
)
504 __free_pages_ok(page
, compound_order(page
));
507 void prep_compound_page(struct page
*page
, unsigned int order
)
510 int nr_pages
= 1 << order
;
512 set_compound_page_dtor(page
, COMPOUND_PAGE_DTOR
);
513 set_compound_order(page
, order
);
515 for (i
= 1; i
< nr_pages
; i
++) {
516 struct page
*p
= page
+ i
;
517 set_page_count(p
, 0);
518 set_compound_head(p
, page
);
522 #ifdef CONFIG_DEBUG_PAGEALLOC
523 unsigned int _debug_guardpage_minorder
;
524 bool _debug_pagealloc_enabled __read_mostly
;
525 bool _debug_guardpage_enabled __read_mostly
;
527 static int __init
early_debug_pagealloc(char *buf
)
532 if (strcmp(buf
, "on") == 0)
533 _debug_pagealloc_enabled
= true;
537 early_param("debug_pagealloc", early_debug_pagealloc
);
539 static bool need_debug_guardpage(void)
541 /* If we don't use debug_pagealloc, we don't need guard page */
542 if (!debug_pagealloc_enabled())
548 static void init_debug_guardpage(void)
550 if (!debug_pagealloc_enabled())
553 _debug_guardpage_enabled
= true;
556 struct page_ext_operations debug_guardpage_ops
= {
557 .need
= need_debug_guardpage
,
558 .init
= init_debug_guardpage
,
561 static int __init
debug_guardpage_minorder_setup(char *buf
)
565 if (kstrtoul(buf
, 10, &res
) < 0 || res
> MAX_ORDER
/ 2) {
566 printk(KERN_ERR
"Bad debug_guardpage_minorder value\n");
569 _debug_guardpage_minorder
= res
;
570 printk(KERN_INFO
"Setting debug_guardpage_minorder to %lu\n", res
);
573 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup
);
575 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
576 unsigned int order
, int migratetype
)
578 struct page_ext
*page_ext
;
580 if (!debug_guardpage_enabled())
583 page_ext
= lookup_page_ext(page
);
584 if (unlikely(!page_ext
))
587 __set_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
589 INIT_LIST_HEAD(&page
->lru
);
590 set_page_private(page
, order
);
591 /* Guard pages are not available for any usage */
592 __mod_zone_freepage_state(zone
, -(1 << order
), migratetype
);
595 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
596 unsigned int order
, int migratetype
)
598 struct page_ext
*page_ext
;
600 if (!debug_guardpage_enabled())
603 page_ext
= lookup_page_ext(page
);
604 if (unlikely(!page_ext
))
607 __clear_bit(PAGE_EXT_DEBUG_GUARD
, &page_ext
->flags
);
609 set_page_private(page
, 0);
610 if (!is_migrate_isolate(migratetype
))
611 __mod_zone_freepage_state(zone
, (1 << order
), migratetype
);
614 struct page_ext_operations debug_guardpage_ops
= { NULL
, };
615 static inline void set_page_guard(struct zone
*zone
, struct page
*page
,
616 unsigned int order
, int migratetype
) {}
617 static inline void clear_page_guard(struct zone
*zone
, struct page
*page
,
618 unsigned int order
, int migratetype
) {}
621 static inline void set_page_order(struct page
*page
, unsigned int order
)
623 set_page_private(page
, order
);
624 __SetPageBuddy(page
);
627 static inline void rmv_page_order(struct page
*page
)
629 __ClearPageBuddy(page
);
630 set_page_private(page
, 0);
634 * This function checks whether a page is free && is the buddy
635 * we can do coalesce a page and its buddy if
636 * (a) the buddy is not in a hole &&
637 * (b) the buddy is in the buddy system &&
638 * (c) a page and its buddy have the same order &&
639 * (d) a page and its buddy are in the same zone.
641 * For recording whether a page is in the buddy system, we set ->_mapcount
642 * PAGE_BUDDY_MAPCOUNT_VALUE.
643 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is
644 * serialized by zone->lock.
646 * For recording page's order, we use page_private(page).
648 static inline int page_is_buddy(struct page
*page
, struct page
*buddy
,
651 if (!pfn_valid_within(page_to_pfn(buddy
)))
654 if (page_is_guard(buddy
) && page_order(buddy
) == order
) {
655 if (page_zone_id(page
) != page_zone_id(buddy
))
658 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
663 if (PageBuddy(buddy
) && page_order(buddy
) == order
) {
665 * zone check is done late to avoid uselessly
666 * calculating zone/node ids for pages that could
669 if (page_zone_id(page
) != page_zone_id(buddy
))
672 VM_BUG_ON_PAGE(page_count(buddy
) != 0, buddy
);
680 * Freeing function for a buddy system allocator.
682 * The concept of a buddy system is to maintain direct-mapped table
683 * (containing bit values) for memory blocks of various "orders".
684 * The bottom level table contains the map for the smallest allocatable
685 * units of memory (here, pages), and each level above it describes
686 * pairs of units from the levels below, hence, "buddies".
687 * At a high level, all that happens here is marking the table entry
688 * at the bottom level available, and propagating the changes upward
689 * as necessary, plus some accounting needed to play nicely with other
690 * parts of the VM system.
691 * At each level, we keep a list of pages, which are heads of continuous
692 * free pages of length of (1 << order) and marked with _mapcount
693 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page)
695 * So when we are allocating or freeing one, we can derive the state of the
696 * other. That is, if we allocate a small block, and both were
697 * free, the remainder of the region must be split into blocks.
698 * If a block is freed, and its buddy is also free, then this
699 * triggers coalescing into a block of larger size.
704 static inline void __free_one_page(struct page
*page
,
706 struct zone
*zone
, unsigned int order
,
709 unsigned long page_idx
;
710 unsigned long combined_idx
;
711 unsigned long uninitialized_var(buddy_idx
);
713 unsigned int max_order
;
715 max_order
= min_t(unsigned int, MAX_ORDER
, pageblock_order
+ 1);
717 VM_BUG_ON(!zone_is_initialized(zone
));
718 VM_BUG_ON_PAGE(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
, page
);
720 VM_BUG_ON(migratetype
== -1);
721 if (likely(!is_migrate_isolate(migratetype
)))
722 __mod_zone_freepage_state(zone
, 1 << order
, migratetype
);
724 page_idx
= pfn
& ((1 << MAX_ORDER
) - 1);
726 VM_BUG_ON_PAGE(page_idx
& ((1 << order
) - 1), page
);
727 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
730 while (order
< max_order
- 1) {
731 buddy_idx
= __find_buddy_index(page_idx
, order
);
732 buddy
= page
+ (buddy_idx
- page_idx
);
733 if (!page_is_buddy(page
, buddy
, order
))
736 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
737 * merge with it and move up one order.
739 if (page_is_guard(buddy
)) {
740 clear_page_guard(zone
, buddy
, order
, migratetype
);
742 list_del(&buddy
->lru
);
743 zone
->free_area
[order
].nr_free
--;
744 rmv_page_order(buddy
);
746 combined_idx
= buddy_idx
& page_idx
;
747 page
= page
+ (combined_idx
- page_idx
);
748 page_idx
= combined_idx
;
751 if (max_order
< MAX_ORDER
) {
752 /* If we are here, it means order is >= pageblock_order.
753 * We want to prevent merge between freepages on isolate
754 * pageblock and normal pageblock. Without this, pageblock
755 * isolation could cause incorrect freepage or CMA accounting.
757 * We don't want to hit this code for the more frequent
760 if (unlikely(has_isolate_pageblock(zone
))) {
763 buddy_idx
= __find_buddy_index(page_idx
, order
);
764 buddy
= page
+ (buddy_idx
- page_idx
);
765 buddy_mt
= get_pageblock_migratetype(buddy
);
767 if (migratetype
!= buddy_mt
768 && (is_migrate_isolate(migratetype
) ||
769 is_migrate_isolate(buddy_mt
)))
773 goto continue_merging
;
777 set_page_order(page
, order
);
780 * If this is not the largest possible page, check if the buddy
781 * of the next-highest order is free. If it is, it's possible
782 * that pages are being freed that will coalesce soon. In case,
783 * that is happening, add the free page to the tail of the list
784 * so it's less likely to be used soon and more likely to be merged
785 * as a higher order page
787 if ((order
< MAX_ORDER
-2) && pfn_valid_within(page_to_pfn(buddy
))) {
788 struct page
*higher_page
, *higher_buddy
;
789 combined_idx
= buddy_idx
& page_idx
;
790 higher_page
= page
+ (combined_idx
- page_idx
);
791 buddy_idx
= __find_buddy_index(combined_idx
, order
+ 1);
792 higher_buddy
= higher_page
+ (buddy_idx
- combined_idx
);
793 if (page_is_buddy(higher_page
, higher_buddy
, order
+ 1)) {
794 list_add_tail(&page
->lru
,
795 &zone
->free_area
[order
].free_list
[migratetype
]);
800 list_add(&page
->lru
, &zone
->free_area
[order
].free_list
[migratetype
]);
802 zone
->free_area
[order
].nr_free
++;
805 static inline int free_pages_check(struct page
*page
)
807 const char *bad_reason
= NULL
;
808 unsigned long bad_flags
= 0;
810 if (unlikely(page_mapcount(page
)))
811 bad_reason
= "nonzero mapcount";
812 if (unlikely(page
->mapping
!= NULL
))
813 bad_reason
= "non-NULL mapping";
814 if (unlikely(atomic_read(&page
->_count
) != 0))
815 bad_reason
= "nonzero _count";
816 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_FREE
)) {
817 bad_reason
= "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
818 bad_flags
= PAGE_FLAGS_CHECK_AT_FREE
;
821 if (unlikely(page
->mem_cgroup
))
822 bad_reason
= "page still charged to cgroup";
824 if (unlikely(bad_reason
)) {
825 bad_page(page
, bad_reason
, bad_flags
);
828 page_cpupid_reset_last(page
);
829 if (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)
830 page
->flags
&= ~PAGE_FLAGS_CHECK_AT_PREP
;
835 * Frees a number of pages from the PCP lists
836 * Assumes all pages on list are in same zone, and of same order.
837 * count is the number of pages to free.
839 * If the zone was previously in an "all pages pinned" state then look to
840 * see if this freeing clears that state.
842 * And clear the zone's pages_scanned counter, to hold off the "all pages are
843 * pinned" detection logic.
845 static void free_pcppages_bulk(struct zone
*zone
, int count
,
846 struct per_cpu_pages
*pcp
)
851 unsigned long nr_scanned
;
853 spin_lock(&zone
->lock
);
854 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
856 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
860 struct list_head
*list
;
863 * Remove pages from lists in a round-robin fashion. A
864 * batch_free count is maintained that is incremented when an
865 * empty list is encountered. This is so more pages are freed
866 * off fuller lists instead of spinning excessively around empty
871 if (++migratetype
== MIGRATE_PCPTYPES
)
873 list
= &pcp
->lists
[migratetype
];
874 } while (list_empty(list
));
876 /* This is the only non-empty list. Free them all. */
877 if (batch_free
== MIGRATE_PCPTYPES
)
878 batch_free
= to_free
;
881 int mt
; /* migratetype of the to-be-freed page */
883 page
= list_entry(list
->prev
, struct page
, lru
);
884 /* must delete as __free_one_page list manipulates */
885 list_del(&page
->lru
);
887 mt
= get_pcppage_migratetype(page
);
888 /* MIGRATE_ISOLATE page should not go to pcplists */
889 VM_BUG_ON_PAGE(is_migrate_isolate(mt
), page
);
890 /* Pageblock could have been isolated meanwhile */
891 if (unlikely(has_isolate_pageblock(zone
)))
892 mt
= get_pageblock_migratetype(page
);
894 __free_one_page(page
, page_to_pfn(page
), zone
, 0, mt
);
895 trace_mm_page_pcpu_drain(page
, 0, mt
);
896 } while (--to_free
&& --batch_free
&& !list_empty(list
));
898 spin_unlock(&zone
->lock
);
901 static void free_one_page(struct zone
*zone
,
902 struct page
*page
, unsigned long pfn
,
906 unsigned long nr_scanned
;
907 spin_lock(&zone
->lock
);
908 nr_scanned
= zone_page_state(zone
, NR_PAGES_SCANNED
);
910 __mod_zone_page_state(zone
, NR_PAGES_SCANNED
, -nr_scanned
);
912 if (unlikely(has_isolate_pageblock(zone
) ||
913 is_migrate_isolate(migratetype
))) {
914 migratetype
= get_pfnblock_migratetype(page
, pfn
);
916 __free_one_page(page
, pfn
, zone
, order
, migratetype
);
917 spin_unlock(&zone
->lock
);
920 static int free_tail_pages_check(struct page
*head_page
, struct page
*page
)
925 * We rely page->lru.next never has bit 0 set, unless the page
926 * is PageTail(). Let's make sure that's true even for poisoned ->lru.
928 BUILD_BUG_ON((unsigned long)LIST_POISON1
& 1);
930 if (!IS_ENABLED(CONFIG_DEBUG_VM
)) {
934 if (unlikely(!PageTail(page
))) {
935 bad_page(page
, "PageTail not set", 0);
938 if (unlikely(compound_head(page
) != head_page
)) {
939 bad_page(page
, "compound_head not consistent", 0);
944 clear_compound_head(page
);
948 static void __meminit
__init_single_page(struct page
*page
, unsigned long pfn
,
949 unsigned long zone
, int nid
)
951 set_page_links(page
, zone
, nid
, pfn
);
952 init_page_count(page
);
953 page_mapcount_reset(page
);
954 page_cpupid_reset_last(page
);
956 INIT_LIST_HEAD(&page
->lru
);
957 #ifdef WANT_PAGE_VIRTUAL
958 /* The shift won't overflow because ZONE_NORMAL is below 4G. */
959 if (!is_highmem_idx(zone
))
960 set_page_address(page
, __va(pfn
<< PAGE_SHIFT
));
964 static void __meminit
__init_single_pfn(unsigned long pfn
, unsigned long zone
,
967 return __init_single_page(pfn_to_page(pfn
), pfn
, zone
, nid
);
970 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
971 static void init_reserved_page(unsigned long pfn
)
976 if (!early_page_uninitialised(pfn
))
979 nid
= early_pfn_to_nid(pfn
);
980 pgdat
= NODE_DATA(nid
);
982 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
983 struct zone
*zone
= &pgdat
->node_zones
[zid
];
985 if (pfn
>= zone
->zone_start_pfn
&& pfn
< zone_end_pfn(zone
))
988 __init_single_pfn(pfn
, zid
, nid
);
991 static inline void init_reserved_page(unsigned long pfn
)
994 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
997 * Initialised pages do not have PageReserved set. This function is
998 * called for each range allocated by the bootmem allocator and
999 * marks the pages PageReserved. The remaining valid pages are later
1000 * sent to the buddy page allocator.
1002 void __meminit
reserve_bootmem_region(phys_addr_t start
, phys_addr_t end
)
1004 unsigned long start_pfn
= PFN_DOWN(start
);
1005 unsigned long end_pfn
= PFN_UP(end
);
1007 for (; start_pfn
< end_pfn
; start_pfn
++) {
1008 if (pfn_valid(start_pfn
)) {
1009 struct page
*page
= pfn_to_page(start_pfn
);
1011 init_reserved_page(start_pfn
);
1013 /* Avoid false-positive PageTail() */
1014 INIT_LIST_HEAD(&page
->lru
);
1016 SetPageReserved(page
);
1021 static bool free_pages_prepare(struct page
*page
, unsigned int order
)
1023 bool compound
= PageCompound(page
);
1026 VM_BUG_ON_PAGE(PageTail(page
), page
);
1027 VM_BUG_ON_PAGE(compound
&& compound_order(page
) != order
, page
);
1029 trace_mm_page_free(page
, order
);
1030 kmemcheck_free_shadow(page
, order
);
1031 kasan_free_pages(page
, order
);
1034 page
->mapping
= NULL
;
1035 bad
+= free_pages_check(page
);
1036 for (i
= 1; i
< (1 << order
); i
++) {
1038 bad
+= free_tail_pages_check(page
, page
+ i
);
1039 bad
+= free_pages_check(page
+ i
);
1044 reset_page_owner(page
, order
);
1046 if (!PageHighMem(page
)) {
1047 debug_check_no_locks_freed(page_address(page
),
1048 PAGE_SIZE
<< order
);
1049 debug_check_no_obj_freed(page_address(page
),
1050 PAGE_SIZE
<< order
);
1052 arch_free_page(page
, order
);
1053 kernel_map_pages(page
, 1 << order
, 0);
1058 static void __free_pages_ok(struct page
*page
, unsigned int order
)
1060 unsigned long flags
;
1062 unsigned long pfn
= page_to_pfn(page
);
1064 if (!free_pages_prepare(page
, order
))
1067 migratetype
= get_pfnblock_migratetype(page
, pfn
);
1068 local_irq_save(flags
);
1069 __count_vm_events(PGFREE
, 1 << order
);
1070 free_one_page(page_zone(page
), page
, pfn
, order
, migratetype
);
1071 local_irq_restore(flags
);
1074 static void __init
__free_pages_boot_core(struct page
*page
,
1075 unsigned long pfn
, unsigned int order
)
1077 unsigned int nr_pages
= 1 << order
;
1078 struct page
*p
= page
;
1082 for (loop
= 0; loop
< (nr_pages
- 1); loop
++, p
++) {
1084 __ClearPageReserved(p
);
1085 set_page_count(p
, 0);
1087 __ClearPageReserved(p
);
1088 set_page_count(p
, 0);
1090 page_zone(page
)->managed_pages
+= nr_pages
;
1091 set_page_refcounted(page
);
1092 __free_pages(page
, order
);
1095 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
1096 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1098 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata
;
1100 int __meminit
early_pfn_to_nid(unsigned long pfn
)
1102 static DEFINE_SPINLOCK(early_pfn_lock
);
1105 spin_lock(&early_pfn_lock
);
1106 nid
= __early_pfn_to_nid(pfn
, &early_pfnnid_cache
);
1108 nid
= first_online_node
;
1109 spin_unlock(&early_pfn_lock
);
1115 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1116 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1117 struct mminit_pfnnid_cache
*state
)
1121 nid
= __early_pfn_to_nid(pfn
, state
);
1122 if (nid
>= 0 && nid
!= node
)
1127 /* Only safe to use early in boot when initialisation is single-threaded */
1128 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1130 return meminit_pfn_in_nid(pfn
, node
, &early_pfnnid_cache
);
1135 static inline bool __meminit
early_pfn_in_nid(unsigned long pfn
, int node
)
1139 static inline bool __meminit
meminit_pfn_in_nid(unsigned long pfn
, int node
,
1140 struct mminit_pfnnid_cache
*state
)
1147 void __init
__free_pages_bootmem(struct page
*page
, unsigned long pfn
,
1150 if (early_page_uninitialised(pfn
))
1152 return __free_pages_boot_core(page
, pfn
, order
);
1155 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1156 static void __init
deferred_free_range(struct page
*page
,
1157 unsigned long pfn
, int nr_pages
)
1164 /* Free a large naturally-aligned chunk if possible */
1165 if (nr_pages
== MAX_ORDER_NR_PAGES
&&
1166 (pfn
& (MAX_ORDER_NR_PAGES
-1)) == 0) {
1167 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
1168 __free_pages_boot_core(page
, pfn
, MAX_ORDER
-1);
1172 for (i
= 0; i
< nr_pages
; i
++, page
++, pfn
++)
1173 __free_pages_boot_core(page
, pfn
, 0);
1176 /* Completion tracking for deferred_init_memmap() threads */
1177 static atomic_t pgdat_init_n_undone __initdata
;
1178 static __initdata
DECLARE_COMPLETION(pgdat_init_all_done_comp
);
1180 static inline void __init
pgdat_init_report_one_done(void)
1182 if (atomic_dec_and_test(&pgdat_init_n_undone
))
1183 complete(&pgdat_init_all_done_comp
);
1186 /* Initialise remaining memory on a node */
1187 static int __init
deferred_init_memmap(void *data
)
1189 pg_data_t
*pgdat
= data
;
1190 int nid
= pgdat
->node_id
;
1191 struct mminit_pfnnid_cache nid_init_state
= { };
1192 unsigned long start
= jiffies
;
1193 unsigned long nr_pages
= 0;
1194 unsigned long walk_start
, walk_end
;
1197 unsigned long first_init_pfn
= pgdat
->first_deferred_pfn
;
1198 const struct cpumask
*cpumask
= cpumask_of_node(pgdat
->node_id
);
1200 if (first_init_pfn
== ULONG_MAX
) {
1201 pgdat_init_report_one_done();
1205 /* Bind memory initialisation thread to a local node if possible */
1206 if (!cpumask_empty(cpumask
))
1207 set_cpus_allowed_ptr(current
, cpumask
);
1209 /* Sanity check boundaries */
1210 BUG_ON(pgdat
->first_deferred_pfn
< pgdat
->node_start_pfn
);
1211 BUG_ON(pgdat
->first_deferred_pfn
> pgdat_end_pfn(pgdat
));
1212 pgdat
->first_deferred_pfn
= ULONG_MAX
;
1214 /* Only the highest zone is deferred so find it */
1215 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1216 zone
= pgdat
->node_zones
+ zid
;
1217 if (first_init_pfn
< zone_end_pfn(zone
))
1221 for_each_mem_pfn_range(i
, nid
, &walk_start
, &walk_end
, NULL
) {
1222 unsigned long pfn
, end_pfn
;
1223 struct page
*page
= NULL
;
1224 struct page
*free_base_page
= NULL
;
1225 unsigned long free_base_pfn
= 0;
1228 end_pfn
= min(walk_end
, zone_end_pfn(zone
));
1229 pfn
= first_init_pfn
;
1230 if (pfn
< walk_start
)
1232 if (pfn
< zone
->zone_start_pfn
)
1233 pfn
= zone
->zone_start_pfn
;
1235 for (; pfn
< end_pfn
; pfn
++) {
1236 if (!pfn_valid_within(pfn
))
1240 * Ensure pfn_valid is checked every
1241 * MAX_ORDER_NR_PAGES for memory holes
1243 if ((pfn
& (MAX_ORDER_NR_PAGES
- 1)) == 0) {
1244 if (!pfn_valid(pfn
)) {
1250 if (!meminit_pfn_in_nid(pfn
, nid
, &nid_init_state
)) {
1255 /* Minimise pfn page lookups and scheduler checks */
1256 if (page
&& (pfn
& (MAX_ORDER_NR_PAGES
- 1)) != 0) {
1259 nr_pages
+= nr_to_free
;
1260 deferred_free_range(free_base_page
,
1261 free_base_pfn
, nr_to_free
);
1262 free_base_page
= NULL
;
1263 free_base_pfn
= nr_to_free
= 0;
1265 page
= pfn_to_page(pfn
);
1270 VM_BUG_ON(page_zone(page
) != zone
);
1274 __init_single_page(page
, pfn
, zid
, nid
);
1275 if (!free_base_page
) {
1276 free_base_page
= page
;
1277 free_base_pfn
= pfn
;
1282 /* Where possible, batch up pages for a single free */
1285 /* Free the current block of pages to allocator */
1286 nr_pages
+= nr_to_free
;
1287 deferred_free_range(free_base_page
, free_base_pfn
,
1289 free_base_page
= NULL
;
1290 free_base_pfn
= nr_to_free
= 0;
1293 first_init_pfn
= max(end_pfn
, first_init_pfn
);
1296 /* Sanity check that the next zone really is unpopulated */
1297 WARN_ON(++zid
< MAX_NR_ZONES
&& populated_zone(++zone
));
1299 pr_info("node %d initialised, %lu pages in %ums\n", nid
, nr_pages
,
1300 jiffies_to_msecs(jiffies
- start
));
1302 pgdat_init_report_one_done();
1306 void __init
page_alloc_init_late(void)
1310 /* There will be num_node_state(N_MEMORY) threads */
1311 atomic_set(&pgdat_init_n_undone
, num_node_state(N_MEMORY
));
1312 for_each_node_state(nid
, N_MEMORY
) {
1313 kthread_run(deferred_init_memmap
, NODE_DATA(nid
), "pgdatinit%d", nid
);
1316 /* Block until all are initialised */
1317 wait_for_completion(&pgdat_init_all_done_comp
);
1319 /* Reinit limits that are based on free pages after the kernel is up */
1320 files_maxfiles_init();
1322 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1325 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
1326 void __init
init_cma_reserved_pageblock(struct page
*page
)
1328 unsigned i
= pageblock_nr_pages
;
1329 struct page
*p
= page
;
1332 __ClearPageReserved(p
);
1333 set_page_count(p
, 0);
1336 set_pageblock_migratetype(page
, MIGRATE_CMA
);
1338 if (pageblock_order
>= MAX_ORDER
) {
1339 i
= pageblock_nr_pages
;
1342 set_page_refcounted(p
);
1343 __free_pages(p
, MAX_ORDER
- 1);
1344 p
+= MAX_ORDER_NR_PAGES
;
1345 } while (i
-= MAX_ORDER_NR_PAGES
);
1347 set_page_refcounted(page
);
1348 __free_pages(page
, pageblock_order
);
1351 adjust_managed_page_count(page
, pageblock_nr_pages
);
1356 * The order of subdivision here is critical for the IO subsystem.
1357 * Please do not alter this order without good reasons and regression
1358 * testing. Specifically, as large blocks of memory are subdivided,
1359 * the order in which smaller blocks are delivered depends on the order
1360 * they're subdivided in this function. This is the primary factor
1361 * influencing the order in which pages are delivered to the IO
1362 * subsystem according to empirical testing, and this is also justified
1363 * by considering the behavior of a buddy system containing a single
1364 * large block of memory acted on by a series of small allocations.
1365 * This behavior is a critical factor in sglist merging's success.
1369 static inline void expand(struct zone
*zone
, struct page
*page
,
1370 int low
, int high
, struct free_area
*area
,
1373 unsigned long size
= 1 << high
;
1375 while (high
> low
) {
1379 VM_BUG_ON_PAGE(bad_range(zone
, &page
[size
]), &page
[size
]);
1381 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC
) &&
1382 debug_guardpage_enabled() &&
1383 high
< debug_guardpage_minorder()) {
1385 * Mark as guard pages (or page), that will allow to
1386 * merge back to allocator when buddy will be freed.
1387 * Corresponding page table entries will not be touched,
1388 * pages will stay not present in virtual address space
1390 set_page_guard(zone
, &page
[size
], high
, migratetype
);
1393 list_add(&page
[size
].lru
, &area
->free_list
[migratetype
]);
1395 set_page_order(&page
[size
], high
);
1400 * This page is about to be returned from the page allocator
1402 static inline int check_new_page(struct page
*page
)
1404 const char *bad_reason
= NULL
;
1405 unsigned long bad_flags
= 0;
1407 if (unlikely(page_mapcount(page
)))
1408 bad_reason
= "nonzero mapcount";
1409 if (unlikely(page
->mapping
!= NULL
))
1410 bad_reason
= "non-NULL mapping";
1411 if (unlikely(atomic_read(&page
->_count
) != 0))
1412 bad_reason
= "nonzero _count";
1413 if (unlikely(page
->flags
& __PG_HWPOISON
)) {
1414 bad_reason
= "HWPoisoned (hardware-corrupted)";
1415 bad_flags
= __PG_HWPOISON
;
1417 if (unlikely(page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
)) {
1418 bad_reason
= "PAGE_FLAGS_CHECK_AT_PREP flag set";
1419 bad_flags
= PAGE_FLAGS_CHECK_AT_PREP
;
1422 if (unlikely(page
->mem_cgroup
))
1423 bad_reason
= "page still charged to cgroup";
1425 if (unlikely(bad_reason
)) {
1426 bad_page(page
, bad_reason
, bad_flags
);
1432 static int prep_new_page(struct page
*page
, unsigned int order
, gfp_t gfp_flags
,
1437 for (i
= 0; i
< (1 << order
); i
++) {
1438 struct page
*p
= page
+ i
;
1439 if (unlikely(check_new_page(p
)))
1443 set_page_private(page
, 0);
1444 set_page_refcounted(page
);
1446 arch_alloc_page(page
, order
);
1447 kernel_map_pages(page
, 1 << order
, 1);
1448 kasan_alloc_pages(page
, order
);
1450 if (gfp_flags
& __GFP_ZERO
)
1451 for (i
= 0; i
< (1 << order
); i
++)
1452 clear_highpage(page
+ i
);
1454 if (order
&& (gfp_flags
& __GFP_COMP
))
1455 prep_compound_page(page
, order
);
1457 set_page_owner(page
, order
, gfp_flags
);
1460 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
1461 * allocate the page. The expectation is that the caller is taking
1462 * steps that will free more memory. The caller should avoid the page
1463 * being used for !PFMEMALLOC purposes.
1465 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
1466 set_page_pfmemalloc(page
);
1468 clear_page_pfmemalloc(page
);
1474 * Go through the free lists for the given migratetype and remove
1475 * the smallest available page from the freelists
1478 struct page
*__rmqueue_smallest(struct zone
*zone
, unsigned int order
,
1481 unsigned int current_order
;
1482 struct free_area
*area
;
1485 /* Find a page of the appropriate size in the preferred list */
1486 for (current_order
= order
; current_order
< MAX_ORDER
; ++current_order
) {
1487 area
= &(zone
->free_area
[current_order
]);
1488 if (list_empty(&area
->free_list
[migratetype
]))
1491 page
= list_entry(area
->free_list
[migratetype
].next
,
1493 list_del(&page
->lru
);
1494 rmv_page_order(page
);
1496 expand(zone
, page
, order
, current_order
, area
, migratetype
);
1497 set_pcppage_migratetype(page
, migratetype
);
1506 * This array describes the order lists are fallen back to when
1507 * the free lists for the desirable migrate type are depleted
1509 static int fallbacks
[MIGRATE_TYPES
][4] = {
1510 [MIGRATE_UNMOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1511 [MIGRATE_RECLAIMABLE
] = { MIGRATE_UNMOVABLE
, MIGRATE_MOVABLE
, MIGRATE_TYPES
},
1512 [MIGRATE_MOVABLE
] = { MIGRATE_RECLAIMABLE
, MIGRATE_UNMOVABLE
, MIGRATE_TYPES
},
1514 [MIGRATE_CMA
] = { MIGRATE_TYPES
}, /* Never used */
1516 #ifdef CONFIG_MEMORY_ISOLATION
1517 [MIGRATE_ISOLATE
] = { MIGRATE_TYPES
}, /* Never used */
1522 static struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1525 return __rmqueue_smallest(zone
, order
, MIGRATE_CMA
);
1528 static inline struct page
*__rmqueue_cma_fallback(struct zone
*zone
,
1529 unsigned int order
) { return NULL
; }
1533 * Move the free pages in a range to the free lists of the requested type.
1534 * Note that start_page and end_pages are not aligned on a pageblock
1535 * boundary. If alignment is required, use move_freepages_block()
1537 int move_freepages(struct zone
*zone
,
1538 struct page
*start_page
, struct page
*end_page
,
1543 int pages_moved
= 0;
1545 #ifndef CONFIG_HOLES_IN_ZONE
1547 * page_zone is not safe to call in this context when
1548 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
1549 * anyway as we check zone boundaries in move_freepages_block().
1550 * Remove at a later date when no bug reports exist related to
1551 * grouping pages by mobility
1553 VM_BUG_ON(page_zone(start_page
) != page_zone(end_page
));
1556 for (page
= start_page
; page
<= end_page
;) {
1557 if (!pfn_valid_within(page_to_pfn(page
))) {
1562 /* Make sure we are not inadvertently changing nodes */
1563 VM_BUG_ON_PAGE(page_to_nid(page
) != zone_to_nid(zone
), page
);
1565 if (!PageBuddy(page
)) {
1570 order
= page_order(page
);
1571 list_move(&page
->lru
,
1572 &zone
->free_area
[order
].free_list
[migratetype
]);
1574 pages_moved
+= 1 << order
;
1580 int move_freepages_block(struct zone
*zone
, struct page
*page
,
1583 unsigned long start_pfn
, end_pfn
;
1584 struct page
*start_page
, *end_page
;
1586 start_pfn
= page_to_pfn(page
);
1587 start_pfn
= start_pfn
& ~(pageblock_nr_pages
-1);
1588 start_page
= pfn_to_page(start_pfn
);
1589 end_page
= start_page
+ pageblock_nr_pages
- 1;
1590 end_pfn
= start_pfn
+ pageblock_nr_pages
- 1;
1592 /* Do not cross zone boundaries */
1593 if (!zone_spans_pfn(zone
, start_pfn
))
1595 if (!zone_spans_pfn(zone
, end_pfn
))
1598 return move_freepages(zone
, start_page
, end_page
, migratetype
);
1601 static void change_pageblock_range(struct page
*pageblock_page
,
1602 int start_order
, int migratetype
)
1604 int nr_pageblocks
= 1 << (start_order
- pageblock_order
);
1606 while (nr_pageblocks
--) {
1607 set_pageblock_migratetype(pageblock_page
, migratetype
);
1608 pageblock_page
+= pageblock_nr_pages
;
1613 * When we are falling back to another migratetype during allocation, try to
1614 * steal extra free pages from the same pageblocks to satisfy further
1615 * allocations, instead of polluting multiple pageblocks.
1617 * If we are stealing a relatively large buddy page, it is likely there will
1618 * be more free pages in the pageblock, so try to steal them all. For
1619 * reclaimable and unmovable allocations, we steal regardless of page size,
1620 * as fragmentation caused by those allocations polluting movable pageblocks
1621 * is worse than movable allocations stealing from unmovable and reclaimable
1624 static bool can_steal_fallback(unsigned int order
, int start_mt
)
1627 * Leaving this order check is intended, although there is
1628 * relaxed order check in next check. The reason is that
1629 * we can actually steal whole pageblock if this condition met,
1630 * but, below check doesn't guarantee it and that is just heuristic
1631 * so could be changed anytime.
1633 if (order
>= pageblock_order
)
1636 if (order
>= pageblock_order
/ 2 ||
1637 start_mt
== MIGRATE_RECLAIMABLE
||
1638 start_mt
== MIGRATE_UNMOVABLE
||
1639 page_group_by_mobility_disabled
)
1646 * This function implements actual steal behaviour. If order is large enough,
1647 * we can steal whole pageblock. If not, we first move freepages in this
1648 * pageblock and check whether half of pages are moved or not. If half of
1649 * pages are moved, we can change migratetype of pageblock and permanently
1650 * use it's pages as requested migratetype in the future.
1652 static void steal_suitable_fallback(struct zone
*zone
, struct page
*page
,
1655 unsigned int current_order
= page_order(page
);
1658 /* Take ownership for orders >= pageblock_order */
1659 if (current_order
>= pageblock_order
) {
1660 change_pageblock_range(page
, current_order
, start_type
);
1664 pages
= move_freepages_block(zone
, page
, start_type
);
1666 /* Claim the whole block if over half of it is free */
1667 if (pages
>= (1 << (pageblock_order
-1)) ||
1668 page_group_by_mobility_disabled
)
1669 set_pageblock_migratetype(page
, start_type
);
1673 * Check whether there is a suitable fallback freepage with requested order.
1674 * If only_stealable is true, this function returns fallback_mt only if
1675 * we can steal other freepages all together. This would help to reduce
1676 * fragmentation due to mixed migratetype pages in one pageblock.
1678 int find_suitable_fallback(struct free_area
*area
, unsigned int order
,
1679 int migratetype
, bool only_stealable
, bool *can_steal
)
1684 if (area
->nr_free
== 0)
1689 fallback_mt
= fallbacks
[migratetype
][i
];
1690 if (fallback_mt
== MIGRATE_TYPES
)
1693 if (list_empty(&area
->free_list
[fallback_mt
]))
1696 if (can_steal_fallback(order
, migratetype
))
1699 if (!only_stealable
)
1710 * Reserve a pageblock for exclusive use of high-order atomic allocations if
1711 * there are no empty page blocks that contain a page with a suitable order
1713 static void reserve_highatomic_pageblock(struct page
*page
, struct zone
*zone
,
1714 unsigned int alloc_order
)
1717 unsigned long max_managed
, flags
;
1720 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
1721 * Check is race-prone but harmless.
1723 max_managed
= (zone
->managed_pages
/ 100) + pageblock_nr_pages
;
1724 if (zone
->nr_reserved_highatomic
>= max_managed
)
1727 spin_lock_irqsave(&zone
->lock
, flags
);
1729 /* Recheck the nr_reserved_highatomic limit under the lock */
1730 if (zone
->nr_reserved_highatomic
>= max_managed
)
1734 mt
= get_pageblock_migratetype(page
);
1735 if (mt
!= MIGRATE_HIGHATOMIC
&&
1736 !is_migrate_isolate(mt
) && !is_migrate_cma(mt
)) {
1737 zone
->nr_reserved_highatomic
+= pageblock_nr_pages
;
1738 set_pageblock_migratetype(page
, MIGRATE_HIGHATOMIC
);
1739 move_freepages_block(zone
, page
, MIGRATE_HIGHATOMIC
);
1743 spin_unlock_irqrestore(&zone
->lock
, flags
);
1747 * Used when an allocation is about to fail under memory pressure. This
1748 * potentially hurts the reliability of high-order allocations when under
1749 * intense memory pressure but failed atomic allocations should be easier
1750 * to recover from than an OOM.
1752 static void unreserve_highatomic_pageblock(const struct alloc_context
*ac
)
1754 struct zonelist
*zonelist
= ac
->zonelist
;
1755 unsigned long flags
;
1761 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
1763 /* Preserve at least one pageblock */
1764 if (zone
->nr_reserved_highatomic
<= pageblock_nr_pages
)
1767 spin_lock_irqsave(&zone
->lock
, flags
);
1768 for (order
= 0; order
< MAX_ORDER
; order
++) {
1769 struct free_area
*area
= &(zone
->free_area
[order
]);
1771 if (list_empty(&area
->free_list
[MIGRATE_HIGHATOMIC
]))
1774 page
= list_entry(area
->free_list
[MIGRATE_HIGHATOMIC
].next
,
1778 * In page freeing path, migratetype change is racy so
1779 * we can counter several free pages in a pageblock
1780 * in this loop althoug we changed the pageblock type
1781 * from highatomic to ac->migratetype. So we should
1782 * adjust the count once.
1784 if (get_pageblock_migratetype(page
) ==
1785 MIGRATE_HIGHATOMIC
) {
1787 * It should never happen but changes to
1788 * locking could inadvertently allow a per-cpu
1789 * drain to add pages to MIGRATE_HIGHATOMIC
1790 * while unreserving so be safe and watch for
1793 zone
->nr_reserved_highatomic
-= min(
1795 zone
->nr_reserved_highatomic
);
1799 * Convert to ac->migratetype and avoid the normal
1800 * pageblock stealing heuristics. Minimally, the caller
1801 * is doing the work and needs the pages. More
1802 * importantly, if the block was always converted to
1803 * MIGRATE_UNMOVABLE or another type then the number
1804 * of pageblocks that cannot be completely freed
1807 set_pageblock_migratetype(page
, ac
->migratetype
);
1808 move_freepages_block(zone
, page
, ac
->migratetype
);
1809 spin_unlock_irqrestore(&zone
->lock
, flags
);
1812 spin_unlock_irqrestore(&zone
->lock
, flags
);
1816 /* Remove an element from the buddy allocator from the fallback list */
1817 static inline struct page
*
1818 __rmqueue_fallback(struct zone
*zone
, unsigned int order
, int start_migratetype
)
1820 struct free_area
*area
;
1821 unsigned int current_order
;
1826 /* Find the largest possible block of pages in the other list */
1827 for (current_order
= MAX_ORDER
-1;
1828 current_order
>= order
&& current_order
<= MAX_ORDER
-1;
1830 area
= &(zone
->free_area
[current_order
]);
1831 fallback_mt
= find_suitable_fallback(area
, current_order
,
1832 start_migratetype
, false, &can_steal
);
1833 if (fallback_mt
== -1)
1836 page
= list_entry(area
->free_list
[fallback_mt
].next
,
1839 steal_suitable_fallback(zone
, page
, start_migratetype
);
1841 /* Remove the page from the freelists */
1843 list_del(&page
->lru
);
1844 rmv_page_order(page
);
1846 expand(zone
, page
, order
, current_order
, area
,
1849 * The pcppage_migratetype may differ from pageblock's
1850 * migratetype depending on the decisions in
1851 * find_suitable_fallback(). This is OK as long as it does not
1852 * differ for MIGRATE_CMA pageblocks. Those can be used as
1853 * fallback only via special __rmqueue_cma_fallback() function
1855 set_pcppage_migratetype(page
, start_migratetype
);
1857 trace_mm_page_alloc_extfrag(page
, order
, current_order
,
1858 start_migratetype
, fallback_mt
);
1867 * Do the hard work of removing an element from the buddy allocator.
1868 * Call me with the zone->lock already held.
1870 static struct page
*__rmqueue(struct zone
*zone
, unsigned int order
,
1871 int migratetype
, gfp_t gfp_flags
)
1875 page
= __rmqueue_smallest(zone
, order
, migratetype
);
1876 if (unlikely(!page
)) {
1877 if (migratetype
== MIGRATE_MOVABLE
)
1878 page
= __rmqueue_cma_fallback(zone
, order
);
1881 page
= __rmqueue_fallback(zone
, order
, migratetype
);
1884 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
1889 * Obtain a specified number of elements from the buddy allocator, all under
1890 * a single hold of the lock, for efficiency. Add them to the supplied list.
1891 * Returns the number of new pages which were placed at *list.
1893 static int rmqueue_bulk(struct zone
*zone
, unsigned int order
,
1894 unsigned long count
, struct list_head
*list
,
1895 int migratetype
, bool cold
)
1899 spin_lock(&zone
->lock
);
1900 for (i
= 0; i
< count
; ++i
) {
1901 struct page
*page
= __rmqueue(zone
, order
, migratetype
, 0);
1902 if (unlikely(page
== NULL
))
1906 * Split buddy pages returned by expand() are received here
1907 * in physical page order. The page is added to the callers and
1908 * list and the list head then moves forward. From the callers
1909 * perspective, the linked list is ordered by page number in
1910 * some conditions. This is useful for IO devices that can
1911 * merge IO requests if the physical pages are ordered
1915 list_add(&page
->lru
, list
);
1917 list_add_tail(&page
->lru
, list
);
1919 if (is_migrate_cma(get_pcppage_migratetype(page
)))
1920 __mod_zone_page_state(zone
, NR_FREE_CMA_PAGES
,
1923 __mod_zone_page_state(zone
, NR_FREE_PAGES
, -(i
<< order
));
1924 spin_unlock(&zone
->lock
);
1930 * Called from the vmstat counter updater to drain pagesets of this
1931 * currently executing processor on remote nodes after they have
1934 * Note that this function must be called with the thread pinned to
1935 * a single processor.
1937 void drain_zone_pages(struct zone
*zone
, struct per_cpu_pages
*pcp
)
1939 unsigned long flags
;
1940 int to_drain
, batch
;
1942 local_irq_save(flags
);
1943 batch
= READ_ONCE(pcp
->batch
);
1944 to_drain
= min(pcp
->count
, batch
);
1946 free_pcppages_bulk(zone
, to_drain
, pcp
);
1947 pcp
->count
-= to_drain
;
1949 local_irq_restore(flags
);
1954 * Drain pcplists of the indicated processor and zone.
1956 * The processor must either be the current processor and the
1957 * thread pinned to the current processor or a processor that
1960 static void drain_pages_zone(unsigned int cpu
, struct zone
*zone
)
1962 unsigned long flags
;
1963 struct per_cpu_pageset
*pset
;
1964 struct per_cpu_pages
*pcp
;
1966 local_irq_save(flags
);
1967 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
1971 free_pcppages_bulk(zone
, pcp
->count
, pcp
);
1974 local_irq_restore(flags
);
1978 * Drain pcplists of all zones on the indicated processor.
1980 * The processor must either be the current processor and the
1981 * thread pinned to the current processor or a processor that
1984 static void drain_pages(unsigned int cpu
)
1988 for_each_populated_zone(zone
) {
1989 drain_pages_zone(cpu
, zone
);
1994 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
1996 * The CPU has to be pinned. When zone parameter is non-NULL, spill just
1997 * the single zone's pages.
1999 void drain_local_pages(struct zone
*zone
)
2001 int cpu
= smp_processor_id();
2004 drain_pages_zone(cpu
, zone
);
2010 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
2012 * When zone parameter is non-NULL, spill just the single zone's pages.
2014 * Note that this code is protected against sending an IPI to an offline
2015 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
2016 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
2017 * nothing keeps CPUs from showing up after we populated the cpumask and
2018 * before the call to on_each_cpu_mask().
2020 void drain_all_pages(struct zone
*zone
)
2025 * Allocate in the BSS so we wont require allocation in
2026 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
2028 static cpumask_t cpus_with_pcps
;
2031 * We don't care about racing with CPU hotplug event
2032 * as offline notification will cause the notified
2033 * cpu to drain that CPU pcps and on_each_cpu_mask
2034 * disables preemption as part of its processing
2036 for_each_online_cpu(cpu
) {
2037 struct per_cpu_pageset
*pcp
;
2039 bool has_pcps
= false;
2042 pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
2046 for_each_populated_zone(z
) {
2047 pcp
= per_cpu_ptr(z
->pageset
, cpu
);
2048 if (pcp
->pcp
.count
) {
2056 cpumask_set_cpu(cpu
, &cpus_with_pcps
);
2058 cpumask_clear_cpu(cpu
, &cpus_with_pcps
);
2060 on_each_cpu_mask(&cpus_with_pcps
, (smp_call_func_t
) drain_local_pages
,
2064 #ifdef CONFIG_HIBERNATION
2066 void mark_free_pages(struct zone
*zone
)
2068 unsigned long pfn
, max_zone_pfn
;
2069 unsigned long flags
;
2070 unsigned int order
, t
;
2071 struct list_head
*curr
;
2073 if (zone_is_empty(zone
))
2076 spin_lock_irqsave(&zone
->lock
, flags
);
2078 max_zone_pfn
= zone_end_pfn(zone
);
2079 for (pfn
= zone
->zone_start_pfn
; pfn
< max_zone_pfn
; pfn
++)
2080 if (pfn_valid(pfn
)) {
2081 struct page
*page
= pfn_to_page(pfn
);
2083 if (!swsusp_page_is_forbidden(page
))
2084 swsusp_unset_page_free(page
);
2087 for_each_migratetype_order(order
, t
) {
2088 list_for_each(curr
, &zone
->free_area
[order
].free_list
[t
]) {
2091 pfn
= page_to_pfn(list_entry(curr
, struct page
, lru
));
2092 for (i
= 0; i
< (1UL << order
); i
++)
2093 swsusp_set_page_free(pfn_to_page(pfn
+ i
));
2096 spin_unlock_irqrestore(&zone
->lock
, flags
);
2098 #endif /* CONFIG_PM */
2101 * Free a 0-order page
2102 * cold == true ? free a cold page : free a hot page
2104 void free_hot_cold_page(struct page
*page
, bool cold
)
2106 struct zone
*zone
= page_zone(page
);
2107 struct per_cpu_pages
*pcp
;
2108 unsigned long flags
;
2109 unsigned long pfn
= page_to_pfn(page
);
2112 if (!free_pages_prepare(page
, 0))
2115 migratetype
= get_pfnblock_migratetype(page
, pfn
);
2116 set_pcppage_migratetype(page
, migratetype
);
2117 local_irq_save(flags
);
2118 __count_vm_event(PGFREE
);
2121 * We only track unmovable, reclaimable and movable on pcp lists.
2122 * Free ISOLATE pages back to the allocator because they are being
2123 * offlined but treat RESERVE as movable pages so we can get those
2124 * areas back if necessary. Otherwise, we may have to free
2125 * excessively into the page allocator
2127 if (migratetype
>= MIGRATE_PCPTYPES
) {
2128 if (unlikely(is_migrate_isolate(migratetype
))) {
2129 free_one_page(zone
, page
, pfn
, 0, migratetype
);
2132 migratetype
= MIGRATE_MOVABLE
;
2135 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2137 list_add(&page
->lru
, &pcp
->lists
[migratetype
]);
2139 list_add_tail(&page
->lru
, &pcp
->lists
[migratetype
]);
2141 if (pcp
->count
>= pcp
->high
) {
2142 unsigned long batch
= READ_ONCE(pcp
->batch
);
2143 free_pcppages_bulk(zone
, batch
, pcp
);
2144 pcp
->count
-= batch
;
2148 local_irq_restore(flags
);
2152 * Free a list of 0-order pages
2154 void free_hot_cold_page_list(struct list_head
*list
, bool cold
)
2156 struct page
*page
, *next
;
2158 list_for_each_entry_safe(page
, next
, list
, lru
) {
2159 trace_mm_page_free_batched(page
, cold
);
2160 free_hot_cold_page(page
, cold
);
2165 * split_page takes a non-compound higher-order page, and splits it into
2166 * n (1<<order) sub-pages: page[0..n]
2167 * Each sub-page must be freed individually.
2169 * Note: this is probably too low level an operation for use in drivers.
2170 * Please consult with lkml before using this in your driver.
2172 void split_page(struct page
*page
, unsigned int order
)
2177 VM_BUG_ON_PAGE(PageCompound(page
), page
);
2178 VM_BUG_ON_PAGE(!page_count(page
), page
);
2180 #ifdef CONFIG_KMEMCHECK
2182 * Split shadow pages too, because free(page[0]) would
2183 * otherwise free the whole shadow.
2185 if (kmemcheck_page_is_tracked(page
))
2186 split_page(virt_to_page(page
[0].shadow
), order
);
2189 gfp_mask
= get_page_owner_gfp(page
);
2190 set_page_owner(page
, 0, gfp_mask
);
2191 for (i
= 1; i
< (1 << order
); i
++) {
2192 set_page_refcounted(page
+ i
);
2193 set_page_owner(page
+ i
, 0, gfp_mask
);
2196 EXPORT_SYMBOL_GPL(split_page
);
2198 int __isolate_free_page(struct page
*page
, unsigned int order
)
2200 unsigned long watermark
;
2204 BUG_ON(!PageBuddy(page
));
2206 zone
= page_zone(page
);
2207 mt
= get_pageblock_migratetype(page
);
2209 if (!is_migrate_isolate(mt
)) {
2210 /* Obey watermarks as if the page was being allocated */
2211 watermark
= low_wmark_pages(zone
) + (1 << order
);
2212 if (!zone_watermark_ok(zone
, 0, watermark
, 0, 0))
2215 __mod_zone_freepage_state(zone
, -(1UL << order
), mt
);
2218 /* Remove page from free list */
2219 list_del(&page
->lru
);
2220 zone
->free_area
[order
].nr_free
--;
2221 rmv_page_order(page
);
2223 set_page_owner(page
, order
, __GFP_MOVABLE
);
2225 /* Set the pageblock if the isolated page is at least a pageblock */
2226 if (order
>= pageblock_order
- 1) {
2227 struct page
*endpage
= page
+ (1 << order
) - 1;
2228 for (; page
< endpage
; page
+= pageblock_nr_pages
) {
2229 int mt
= get_pageblock_migratetype(page
);
2230 if (!is_migrate_isolate(mt
) && !is_migrate_cma(mt
))
2231 set_pageblock_migratetype(page
,
2237 return 1UL << order
;
2241 * Similar to split_page except the page is already free. As this is only
2242 * being used for migration, the migratetype of the block also changes.
2243 * As this is called with interrupts disabled, the caller is responsible
2244 * for calling arch_alloc_page() and kernel_map_page() after interrupts
2247 * Note: this is probably too low level an operation for use in drivers.
2248 * Please consult with lkml before using this in your driver.
2250 int split_free_page(struct page
*page
)
2255 order
= page_order(page
);
2257 nr_pages
= __isolate_free_page(page
, order
);
2261 /* Split into individual pages */
2262 set_page_refcounted(page
);
2263 split_page(page
, order
);
2268 * Allocate a page from the given zone. Use pcplists for order-0 allocations.
2271 struct page
*buffered_rmqueue(struct zone
*preferred_zone
,
2272 struct zone
*zone
, unsigned int order
,
2273 gfp_t gfp_flags
, int alloc_flags
, int migratetype
)
2275 unsigned long flags
;
2277 bool cold
= ((gfp_flags
& __GFP_COLD
) != 0);
2279 if (likely(order
== 0)) {
2280 struct per_cpu_pages
*pcp
;
2281 struct list_head
*list
;
2283 local_irq_save(flags
);
2284 pcp
= &this_cpu_ptr(zone
->pageset
)->pcp
;
2285 list
= &pcp
->lists
[migratetype
];
2286 if (list_empty(list
)) {
2287 pcp
->count
+= rmqueue_bulk(zone
, 0,
2290 if (unlikely(list_empty(list
)))
2295 page
= list_entry(list
->prev
, struct page
, lru
);
2297 page
= list_entry(list
->next
, struct page
, lru
);
2299 list_del(&page
->lru
);
2302 if (unlikely(gfp_flags
& __GFP_NOFAIL
)) {
2304 * __GFP_NOFAIL is not to be used in new code.
2306 * All __GFP_NOFAIL callers should be fixed so that they
2307 * properly detect and handle allocation failures.
2309 * We most definitely don't want callers attempting to
2310 * allocate greater than order-1 page units with
2313 WARN_ON_ONCE(order
> 1);
2315 spin_lock_irqsave(&zone
->lock
, flags
);
2318 if (alloc_flags
& ALLOC_HARDER
) {
2319 page
= __rmqueue_smallest(zone
, order
, MIGRATE_HIGHATOMIC
);
2321 trace_mm_page_alloc_zone_locked(page
, order
, migratetype
);
2324 page
= __rmqueue(zone
, order
, migratetype
, gfp_flags
);
2325 spin_unlock(&zone
->lock
);
2328 __mod_zone_freepage_state(zone
, -(1 << order
),
2329 get_pcppage_migratetype(page
));
2332 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
, -(1 << order
));
2333 if (atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]) <= 0 &&
2334 !test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
))
2335 set_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2337 __count_zone_vm_events(PGALLOC
, zone
, 1 << order
);
2338 zone_statistics(preferred_zone
, zone
, gfp_flags
);
2339 local_irq_restore(flags
);
2341 VM_BUG_ON_PAGE(bad_range(zone
, page
), page
);
2345 local_irq_restore(flags
);
2349 #ifdef CONFIG_FAIL_PAGE_ALLOC
2352 struct fault_attr attr
;
2354 bool ignore_gfp_highmem
;
2355 bool ignore_gfp_reclaim
;
2357 } fail_page_alloc
= {
2358 .attr
= FAULT_ATTR_INITIALIZER
,
2359 .ignore_gfp_reclaim
= true,
2360 .ignore_gfp_highmem
= true,
2364 static int __init
setup_fail_page_alloc(char *str
)
2366 return setup_fault_attr(&fail_page_alloc
.attr
, str
);
2368 __setup("fail_page_alloc=", setup_fail_page_alloc
);
2370 static bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2372 if (order
< fail_page_alloc
.min_order
)
2374 if (gfp_mask
& __GFP_NOFAIL
)
2376 if (fail_page_alloc
.ignore_gfp_highmem
&& (gfp_mask
& __GFP_HIGHMEM
))
2378 if (fail_page_alloc
.ignore_gfp_reclaim
&&
2379 (gfp_mask
& __GFP_DIRECT_RECLAIM
))
2382 return should_fail(&fail_page_alloc
.attr
, 1 << order
);
2385 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
2387 static int __init
fail_page_alloc_debugfs(void)
2389 umode_t mode
= S_IFREG
| S_IRUSR
| S_IWUSR
;
2392 dir
= fault_create_debugfs_attr("fail_page_alloc", NULL
,
2393 &fail_page_alloc
.attr
);
2395 return PTR_ERR(dir
);
2397 if (!debugfs_create_bool("ignore-gfp-wait", mode
, dir
,
2398 &fail_page_alloc
.ignore_gfp_reclaim
))
2400 if (!debugfs_create_bool("ignore-gfp-highmem", mode
, dir
,
2401 &fail_page_alloc
.ignore_gfp_highmem
))
2403 if (!debugfs_create_u32("min-order", mode
, dir
,
2404 &fail_page_alloc
.min_order
))
2409 debugfs_remove_recursive(dir
);
2414 late_initcall(fail_page_alloc_debugfs
);
2416 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
2418 #else /* CONFIG_FAIL_PAGE_ALLOC */
2420 static inline bool should_fail_alloc_page(gfp_t gfp_mask
, unsigned int order
)
2425 #endif /* CONFIG_FAIL_PAGE_ALLOC */
2428 * Return true if free base pages are above 'mark'. For high-order checks it
2429 * will return true of the order-0 watermark is reached and there is at least
2430 * one free page of a suitable size. Checking now avoids taking the zone lock
2431 * to check in the allocation paths if no pages are free.
2433 static bool __zone_watermark_ok(struct zone
*z
, unsigned int order
,
2434 unsigned long mark
, int classzone_idx
, int alloc_flags
,
2439 const int alloc_harder
= (alloc_flags
& ALLOC_HARDER
);
2441 /* free_pages may go negative - that's OK */
2442 free_pages
-= (1 << order
) - 1;
2444 if (alloc_flags
& ALLOC_HIGH
)
2448 * If the caller does not have rights to ALLOC_HARDER then subtract
2449 * the high-atomic reserves. This will over-estimate the size of the
2450 * atomic reserve but it avoids a search.
2452 if (likely(!alloc_harder
))
2453 free_pages
-= z
->nr_reserved_highatomic
;
2458 /* If allocation can't use CMA areas don't use free CMA pages */
2459 if (!(alloc_flags
& ALLOC_CMA
))
2460 free_pages
-= zone_page_state(z
, NR_FREE_CMA_PAGES
);
2464 * Check watermarks for an order-0 allocation request. If these
2465 * are not met, then a high-order request also cannot go ahead
2466 * even if a suitable page happened to be free.
2468 if (free_pages
<= min
+ z
->lowmem_reserve
[classzone_idx
])
2471 /* If this is an order-0 request then the watermark is fine */
2475 /* For a high-order request, check at least one suitable page is free */
2476 for (o
= order
; o
< MAX_ORDER
; o
++) {
2477 struct free_area
*area
= &z
->free_area
[o
];
2486 for (mt
= 0; mt
< MIGRATE_PCPTYPES
; mt
++) {
2487 if (!list_empty(&area
->free_list
[mt
]))
2492 if ((alloc_flags
& ALLOC_CMA
) &&
2493 !list_empty(&area
->free_list
[MIGRATE_CMA
])) {
2501 bool zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
2502 int classzone_idx
, int alloc_flags
)
2504 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, alloc_flags
,
2505 zone_page_state(z
, NR_FREE_PAGES
));
2508 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
2509 unsigned long mark
, int classzone_idx
)
2511 long free_pages
= zone_page_state(z
, NR_FREE_PAGES
);
2513 if (z
->percpu_drift_mark
&& free_pages
< z
->percpu_drift_mark
)
2514 free_pages
= zone_page_state_snapshot(z
, NR_FREE_PAGES
);
2516 return __zone_watermark_ok(z
, order
, mark
, classzone_idx
, 0,
2521 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2523 return local_zone
->node
== zone
->node
;
2526 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2528 return node_distance(zone_to_nid(local_zone
), zone_to_nid(zone
)) <=
2531 #else /* CONFIG_NUMA */
2532 static bool zone_local(struct zone
*local_zone
, struct zone
*zone
)
2537 static bool zone_allows_reclaim(struct zone
*local_zone
, struct zone
*zone
)
2541 #endif /* CONFIG_NUMA */
2543 static void reset_alloc_batches(struct zone
*preferred_zone
)
2545 struct zone
*zone
= preferred_zone
->zone_pgdat
->node_zones
;
2548 mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
2549 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
2550 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
2551 clear_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
);
2552 } while (zone
++ != preferred_zone
);
2556 * get_page_from_freelist goes through the zonelist trying to allocate
2559 static struct page
*
2560 get_page_from_freelist(gfp_t gfp_mask
, unsigned int order
, int alloc_flags
,
2561 const struct alloc_context
*ac
)
2563 struct zonelist
*zonelist
= ac
->zonelist
;
2565 struct page
*page
= NULL
;
2567 int nr_fair_skipped
= 0;
2568 bool zonelist_rescan
;
2571 zonelist_rescan
= false;
2574 * Scan zonelist, looking for a zone with enough free.
2575 * See also __cpuset_node_allowed() comment in kernel/cpuset.c.
2577 for_each_zone_zonelist_nodemask(zone
, z
, zonelist
, ac
->high_zoneidx
,
2581 if (cpusets_enabled() &&
2582 (alloc_flags
& ALLOC_CPUSET
) &&
2583 !cpuset_zone_allowed(zone
, gfp_mask
))
2586 * Distribute pages in proportion to the individual
2587 * zone size to ensure fair page aging. The zone a
2588 * page was allocated in should have no effect on the
2589 * time the page has in memory before being reclaimed.
2591 if (alloc_flags
& ALLOC_FAIR
) {
2592 if (!zone_local(ac
->preferred_zone
, zone
))
2594 if (test_bit(ZONE_FAIR_DEPLETED
, &zone
->flags
)) {
2600 * When allocating a page cache page for writing, we
2601 * want to get it from a zone that is within its dirty
2602 * limit, such that no single zone holds more than its
2603 * proportional share of globally allowed dirty pages.
2604 * The dirty limits take into account the zone's
2605 * lowmem reserves and high watermark so that kswapd
2606 * should be able to balance it without having to
2607 * write pages from its LRU list.
2609 * This may look like it could increase pressure on
2610 * lower zones by failing allocations in higher zones
2611 * before they are full. But the pages that do spill
2612 * over are limited as the lower zones are protected
2613 * by this very same mechanism. It should not become
2614 * a practical burden to them.
2616 * XXX: For now, allow allocations to potentially
2617 * exceed the per-zone dirty limit in the slowpath
2618 * (spread_dirty_pages unset) before going into reclaim,
2619 * which is important when on a NUMA setup the allowed
2620 * zones are together not big enough to reach the
2621 * global limit. The proper fix for these situations
2622 * will require awareness of zones in the
2623 * dirty-throttling and the flusher threads.
2625 if (ac
->spread_dirty_pages
&& !zone_dirty_ok(zone
))
2628 mark
= zone
->watermark
[alloc_flags
& ALLOC_WMARK_MASK
];
2629 if (!zone_watermark_ok(zone
, order
, mark
,
2630 ac
->classzone_idx
, alloc_flags
)) {
2633 /* Checked here to keep the fast path fast */
2634 BUILD_BUG_ON(ALLOC_NO_WATERMARKS
< NR_WMARK
);
2635 if (alloc_flags
& ALLOC_NO_WATERMARKS
)
2638 if (zone_reclaim_mode
== 0 ||
2639 !zone_allows_reclaim(ac
->preferred_zone
, zone
))
2642 ret
= zone_reclaim(zone
, gfp_mask
, order
);
2644 case ZONE_RECLAIM_NOSCAN
:
2647 case ZONE_RECLAIM_FULL
:
2648 /* scanned but unreclaimable */
2651 /* did we reclaim enough */
2652 if (zone_watermark_ok(zone
, order
, mark
,
2653 ac
->classzone_idx
, alloc_flags
))
2661 page
= buffered_rmqueue(ac
->preferred_zone
, zone
, order
,
2662 gfp_mask
, alloc_flags
, ac
->migratetype
);
2664 if (prep_new_page(page
, order
, gfp_mask
, alloc_flags
))
2668 * If this is a high-order atomic allocation then check
2669 * if the pageblock should be reserved for the future
2671 if (unlikely(order
&& (alloc_flags
& ALLOC_HARDER
)))
2672 reserve_highatomic_pageblock(page
, zone
, order
);
2679 * The first pass makes sure allocations are spread fairly within the
2680 * local node. However, the local node might have free pages left
2681 * after the fairness batches are exhausted, and remote zones haven't
2682 * even been considered yet. Try once more without fairness, and
2683 * include remote zones now, before entering the slowpath and waking
2684 * kswapd: prefer spilling to a remote zone over swapping locally.
2686 if (alloc_flags
& ALLOC_FAIR
) {
2687 alloc_flags
&= ~ALLOC_FAIR
;
2688 if (nr_fair_skipped
) {
2689 zonelist_rescan
= true;
2690 reset_alloc_batches(ac
->preferred_zone
);
2692 if (nr_online_nodes
> 1)
2693 zonelist_rescan
= true;
2696 if (zonelist_rescan
)
2703 * Large machines with many possible nodes should not always dump per-node
2704 * meminfo in irq context.
2706 static inline bool should_suppress_show_mem(void)
2711 ret
= in_interrupt();
2716 static DEFINE_RATELIMIT_STATE(nopage_rs
,
2717 DEFAULT_RATELIMIT_INTERVAL
,
2718 DEFAULT_RATELIMIT_BURST
);
2720 void warn_alloc_failed(gfp_t gfp_mask
, unsigned int order
, const char *fmt
, ...)
2722 unsigned int filter
= SHOW_MEM_FILTER_NODES
;
2724 if ((gfp_mask
& __GFP_NOWARN
) || !__ratelimit(&nopage_rs
) ||
2725 debug_guardpage_minorder() > 0)
2729 * This documents exceptions given to allocations in certain
2730 * contexts that are allowed to allocate outside current's set
2733 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
2734 if (test_thread_flag(TIF_MEMDIE
) ||
2735 (current
->flags
& (PF_MEMALLOC
| PF_EXITING
)))
2736 filter
&= ~SHOW_MEM_FILTER_NODES
;
2737 if (in_interrupt() || !(gfp_mask
& __GFP_DIRECT_RECLAIM
))
2738 filter
&= ~SHOW_MEM_FILTER_NODES
;
2741 struct va_format vaf
;
2744 va_start(args
, fmt
);
2749 pr_warn("%pV", &vaf
);
2754 pr_warn("%s: page allocation failure: order:%u, mode:0x%x\n",
2755 current
->comm
, order
, gfp_mask
);
2758 if (!should_suppress_show_mem())
2762 static inline struct page
*
2763 __alloc_pages_may_oom(gfp_t gfp_mask
, unsigned int order
,
2764 const struct alloc_context
*ac
, unsigned long *did_some_progress
)
2766 struct oom_control oc
= {
2767 .zonelist
= ac
->zonelist
,
2768 .nodemask
= ac
->nodemask
,
2769 .gfp_mask
= gfp_mask
,
2774 *did_some_progress
= 0;
2777 * Acquire the oom lock. If that fails, somebody else is
2778 * making progress for us.
2780 if (!mutex_trylock(&oom_lock
)) {
2781 *did_some_progress
= 1;
2782 schedule_timeout_uninterruptible(1);
2787 * Go through the zonelist yet one more time, keep very high watermark
2788 * here, this is only to catch a parallel oom killing, we must fail if
2789 * we're still under heavy pressure.
2791 page
= get_page_from_freelist(gfp_mask
| __GFP_HARDWALL
, order
,
2792 ALLOC_WMARK_HIGH
|ALLOC_CPUSET
, ac
);
2796 if (!(gfp_mask
& __GFP_NOFAIL
)) {
2797 /* Coredumps can quickly deplete all memory reserves */
2798 if (current
->flags
& PF_DUMPCORE
)
2800 /* The OOM killer will not help higher order allocs */
2801 if (order
> PAGE_ALLOC_COSTLY_ORDER
)
2803 /* The OOM killer does not needlessly kill tasks for lowmem */
2804 if (ac
->high_zoneidx
< ZONE_NORMAL
)
2806 /* The OOM killer does not compensate for IO-less reclaim */
2807 if (!(gfp_mask
& __GFP_FS
)) {
2809 * XXX: Page reclaim didn't yield anything,
2810 * and the OOM killer can't be invoked, but
2811 * keep looping as per tradition.
2813 *did_some_progress
= 1;
2816 if (pm_suspended_storage())
2818 /* The OOM killer may not free memory on a specific node */
2819 if (gfp_mask
& __GFP_THISNODE
)
2822 /* Exhausted what can be done so it's blamo time */
2823 if (out_of_memory(&oc
) || WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
))
2824 *did_some_progress
= 1;
2826 mutex_unlock(&oom_lock
);
2830 #ifdef CONFIG_COMPACTION
2831 /* Try memory compaction for high-order allocations before reclaim */
2832 static struct page
*
2833 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2834 int alloc_flags
, const struct alloc_context
*ac
,
2835 enum migrate_mode mode
, int *contended_compaction
,
2836 bool *deferred_compaction
)
2838 unsigned long compact_result
;
2844 current
->flags
|= PF_MEMALLOC
;
2845 compact_result
= try_to_compact_pages(gfp_mask
, order
, alloc_flags
, ac
,
2846 mode
, contended_compaction
);
2847 current
->flags
&= ~PF_MEMALLOC
;
2849 switch (compact_result
) {
2850 case COMPACT_DEFERRED
:
2851 *deferred_compaction
= true;
2853 case COMPACT_SKIPPED
:
2860 * At least in one zone compaction wasn't deferred or skipped, so let's
2861 * count a compaction stall
2863 count_vm_event(COMPACTSTALL
);
2865 page
= get_page_from_freelist(gfp_mask
, order
,
2866 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
2869 struct zone
*zone
= page_zone(page
);
2871 zone
->compact_blockskip_flush
= false;
2872 compaction_defer_reset(zone
, order
, true);
2873 count_vm_event(COMPACTSUCCESS
);
2878 * It's bad if compaction run occurs and fails. The most likely reason
2879 * is that pages exist, but not enough to satisfy watermarks.
2881 count_vm_event(COMPACTFAIL
);
2888 static inline struct page
*
2889 __alloc_pages_direct_compact(gfp_t gfp_mask
, unsigned int order
,
2890 int alloc_flags
, const struct alloc_context
*ac
,
2891 enum migrate_mode mode
, int *contended_compaction
,
2892 bool *deferred_compaction
)
2896 #endif /* CONFIG_COMPACTION */
2898 /* Perform direct synchronous page reclaim */
2900 __perform_reclaim(gfp_t gfp_mask
, unsigned int order
,
2901 const struct alloc_context
*ac
)
2903 struct reclaim_state reclaim_state
;
2908 /* We now go into synchronous reclaim */
2909 cpuset_memory_pressure_bump();
2910 current
->flags
|= PF_MEMALLOC
;
2911 lockdep_set_current_reclaim_state(gfp_mask
);
2912 reclaim_state
.reclaimed_slab
= 0;
2913 current
->reclaim_state
= &reclaim_state
;
2915 progress
= try_to_free_pages(ac
->zonelist
, order
, gfp_mask
,
2918 current
->reclaim_state
= NULL
;
2919 lockdep_clear_current_reclaim_state();
2920 current
->flags
&= ~PF_MEMALLOC
;
2927 /* The really slow allocator path where we enter direct reclaim */
2928 static inline struct page
*
2929 __alloc_pages_direct_reclaim(gfp_t gfp_mask
, unsigned int order
,
2930 int alloc_flags
, const struct alloc_context
*ac
,
2931 unsigned long *did_some_progress
)
2933 struct page
*page
= NULL
;
2934 bool drained
= false;
2936 *did_some_progress
= __perform_reclaim(gfp_mask
, order
, ac
);
2937 if (unlikely(!(*did_some_progress
)))
2941 page
= get_page_from_freelist(gfp_mask
, order
,
2942 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
2945 * If an allocation failed after direct reclaim, it could be because
2946 * pages are pinned on the per-cpu lists or in high alloc reserves.
2947 * Shrink them them and try again
2949 if (!page
&& !drained
) {
2950 unreserve_highatomic_pageblock(ac
);
2951 drain_all_pages(NULL
);
2960 * This is called in the allocator slow-path if the allocation request is of
2961 * sufficient urgency to ignore watermarks and take other desperate measures
2963 static inline struct page
*
2964 __alloc_pages_high_priority(gfp_t gfp_mask
, unsigned int order
,
2965 const struct alloc_context
*ac
)
2970 page
= get_page_from_freelist(gfp_mask
, order
,
2971 ALLOC_NO_WATERMARKS
, ac
);
2973 if (!page
&& gfp_mask
& __GFP_NOFAIL
)
2974 wait_iff_congested(ac
->preferred_zone
, BLK_RW_ASYNC
,
2976 } while (!page
&& (gfp_mask
& __GFP_NOFAIL
));
2981 static void wake_all_kswapds(unsigned int order
, const struct alloc_context
*ac
)
2986 for_each_zone_zonelist_nodemask(zone
, z
, ac
->zonelist
,
2987 ac
->high_zoneidx
, ac
->nodemask
)
2988 wakeup_kswapd(zone
, order
, zone_idx(ac
->preferred_zone
));
2992 gfp_to_alloc_flags(gfp_t gfp_mask
)
2994 int alloc_flags
= ALLOC_WMARK_MIN
| ALLOC_CPUSET
;
2996 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2997 BUILD_BUG_ON(__GFP_HIGH
!= (__force gfp_t
) ALLOC_HIGH
);
3000 * The caller may dip into page reserves a bit more if the caller
3001 * cannot run direct reclaim, or if the caller has realtime scheduling
3002 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will
3003 * set both ALLOC_HARDER (__GFP_ATOMIC) and ALLOC_HIGH (__GFP_HIGH).
3005 alloc_flags
|= (__force
int) (gfp_mask
& __GFP_HIGH
);
3007 if (gfp_mask
& __GFP_ATOMIC
) {
3009 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even
3010 * if it can't schedule.
3012 if (!(gfp_mask
& __GFP_NOMEMALLOC
))
3013 alloc_flags
|= ALLOC_HARDER
;
3015 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the
3016 * comment for __cpuset_node_allowed().
3018 alloc_flags
&= ~ALLOC_CPUSET
;
3019 } else if (unlikely(rt_task(current
)) && !in_interrupt())
3020 alloc_flags
|= ALLOC_HARDER
;
3022 if (likely(!(gfp_mask
& __GFP_NOMEMALLOC
))) {
3023 if (gfp_mask
& __GFP_MEMALLOC
)
3024 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3025 else if (in_serving_softirq() && (current
->flags
& PF_MEMALLOC
))
3026 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3027 else if (!in_interrupt() &&
3028 ((current
->flags
& PF_MEMALLOC
) ||
3029 unlikely(test_thread_flag(TIF_MEMDIE
))))
3030 alloc_flags
|= ALLOC_NO_WATERMARKS
;
3033 if (gfpflags_to_migratetype(gfp_mask
) == MIGRATE_MOVABLE
)
3034 alloc_flags
|= ALLOC_CMA
;
3039 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask
)
3041 return !!(gfp_to_alloc_flags(gfp_mask
) & ALLOC_NO_WATERMARKS
);
3044 static inline bool is_thp_gfp_mask(gfp_t gfp_mask
)
3046 return (gfp_mask
& (GFP_TRANSHUGE
| __GFP_KSWAPD_RECLAIM
)) == GFP_TRANSHUGE
;
3049 static inline struct page
*
3050 __alloc_pages_slowpath(gfp_t gfp_mask
, unsigned int order
,
3051 struct alloc_context
*ac
)
3053 bool can_direct_reclaim
= gfp_mask
& __GFP_DIRECT_RECLAIM
;
3054 struct page
*page
= NULL
;
3056 unsigned long pages_reclaimed
= 0;
3057 unsigned long did_some_progress
;
3058 enum migrate_mode migration_mode
= MIGRATE_ASYNC
;
3059 bool deferred_compaction
= false;
3060 int contended_compaction
= COMPACT_CONTENDED_NONE
;
3063 * In the slowpath, we sanity check order to avoid ever trying to
3064 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
3065 * be using allocators in order of preference for an area that is
3068 if (order
>= MAX_ORDER
) {
3069 WARN_ON_ONCE(!(gfp_mask
& __GFP_NOWARN
));
3074 * We also sanity check to catch abuse of atomic reserves being used by
3075 * callers that are not in atomic context.
3077 if (WARN_ON_ONCE((gfp_mask
& (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)) ==
3078 (__GFP_ATOMIC
|__GFP_DIRECT_RECLAIM
)))
3079 gfp_mask
&= ~__GFP_ATOMIC
;
3082 * If this allocation cannot block and it is for a specific node, then
3083 * fail early. There's no need to wakeup kswapd or retry for a
3084 * speculative node-specific allocation.
3086 if (IS_ENABLED(CONFIG_NUMA
) && (gfp_mask
& __GFP_THISNODE
) && !can_direct_reclaim
)
3090 if (gfp_mask
& __GFP_KSWAPD_RECLAIM
)
3091 wake_all_kswapds(order
, ac
);
3094 * OK, we're below the kswapd watermark and have kicked background
3095 * reclaim. Now things get more complex, so set up alloc_flags according
3096 * to how we want to proceed.
3098 alloc_flags
= gfp_to_alloc_flags(gfp_mask
);
3101 * Find the true preferred zone if the allocation is unconstrained by
3104 if (!(alloc_flags
& ALLOC_CPUSET
) && !ac
->nodemask
) {
3105 struct zoneref
*preferred_zoneref
;
3106 preferred_zoneref
= first_zones_zonelist(ac
->zonelist
,
3107 ac
->high_zoneidx
, NULL
, &ac
->preferred_zone
);
3108 ac
->classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
3111 /* This is the last chance, in general, before the goto nopage. */
3112 page
= get_page_from_freelist(gfp_mask
, order
,
3113 alloc_flags
& ~ALLOC_NO_WATERMARKS
, ac
);
3117 /* Allocate without watermarks if the context allows */
3118 if (alloc_flags
& ALLOC_NO_WATERMARKS
) {
3120 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
3121 * the allocation is high priority and these type of
3122 * allocations are system rather than user orientated
3124 ac
->zonelist
= node_zonelist(numa_node_id(), gfp_mask
);
3126 page
= __alloc_pages_high_priority(gfp_mask
, order
, ac
);
3133 /* Caller is not willing to reclaim, we can't balance anything */
3134 if (!can_direct_reclaim
) {
3136 * All existing users of the deprecated __GFP_NOFAIL are
3137 * blockable, so warn of any new users that actually allow this
3138 * type of allocation to fail.
3140 WARN_ON_ONCE(gfp_mask
& __GFP_NOFAIL
);
3144 /* Avoid recursion of direct reclaim */
3145 if (current
->flags
& PF_MEMALLOC
)
3148 /* Avoid allocations with no watermarks from looping endlessly */
3149 if (test_thread_flag(TIF_MEMDIE
) && !(gfp_mask
& __GFP_NOFAIL
))
3153 * Try direct compaction. The first pass is asynchronous. Subsequent
3154 * attempts after direct reclaim are synchronous
3156 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
, ac
,
3158 &contended_compaction
,
3159 &deferred_compaction
);
3163 /* Checks for THP-specific high-order allocations */
3164 if (is_thp_gfp_mask(gfp_mask
)) {
3166 * If compaction is deferred for high-order allocations, it is
3167 * because sync compaction recently failed. If this is the case
3168 * and the caller requested a THP allocation, we do not want
3169 * to heavily disrupt the system, so we fail the allocation
3170 * instead of entering direct reclaim.
3172 if (deferred_compaction
)
3176 * In all zones where compaction was attempted (and not
3177 * deferred or skipped), lock contention has been detected.
3178 * For THP allocation we do not want to disrupt the others
3179 * so we fallback to base pages instead.
3181 if (contended_compaction
== COMPACT_CONTENDED_LOCK
)
3185 * If compaction was aborted due to need_resched(), we do not
3186 * want to further increase allocation latency, unless it is
3187 * khugepaged trying to collapse.
3189 if (contended_compaction
== COMPACT_CONTENDED_SCHED
3190 && !(current
->flags
& PF_KTHREAD
))
3195 * It can become very expensive to allocate transparent hugepages at
3196 * fault, so use asynchronous memory compaction for THP unless it is
3197 * khugepaged trying to collapse.
3199 if (!is_thp_gfp_mask(gfp_mask
) || (current
->flags
& PF_KTHREAD
))
3200 migration_mode
= MIGRATE_SYNC_LIGHT
;
3202 /* Try direct reclaim and then allocating */
3203 page
= __alloc_pages_direct_reclaim(gfp_mask
, order
, alloc_flags
, ac
,
3204 &did_some_progress
);
3208 /* Do not loop if specifically requested */
3209 if (gfp_mask
& __GFP_NORETRY
)
3212 /* Keep reclaiming pages as long as there is reasonable progress */
3213 pages_reclaimed
+= did_some_progress
;
3214 if ((did_some_progress
&& order
<= PAGE_ALLOC_COSTLY_ORDER
) ||
3215 ((gfp_mask
& __GFP_REPEAT
) && pages_reclaimed
< (1 << order
))) {
3216 /* Wait for some write requests to complete then retry */
3217 wait_iff_congested(ac
->preferred_zone
, BLK_RW_ASYNC
, HZ
/50);
3221 /* Reclaim has failed us, start killing things */
3222 page
= __alloc_pages_may_oom(gfp_mask
, order
, ac
, &did_some_progress
);
3226 /* Retry as long as the OOM killer is making progress */
3227 if (did_some_progress
)
3232 * High-order allocations do not necessarily loop after
3233 * direct reclaim and reclaim/compaction depends on compaction
3234 * being called after reclaim so call directly if necessary
3236 page
= __alloc_pages_direct_compact(gfp_mask
, order
, alloc_flags
,
3238 &contended_compaction
,
3239 &deferred_compaction
);
3243 warn_alloc_failed(gfp_mask
, order
, NULL
);
3249 * This is the 'heart' of the zoned buddy allocator.
3252 __alloc_pages_nodemask(gfp_t gfp_mask
, unsigned int order
,
3253 struct zonelist
*zonelist
, nodemask_t
*nodemask
)
3255 struct zoneref
*preferred_zoneref
;
3256 struct page
*page
= NULL
;
3257 unsigned int cpuset_mems_cookie
;
3258 int alloc_flags
= ALLOC_WMARK_LOW
|ALLOC_CPUSET
|ALLOC_FAIR
;
3259 gfp_t alloc_mask
; /* The gfp_t that was actually used for allocation */
3260 struct alloc_context ac
= {
3261 .high_zoneidx
= gfp_zone(gfp_mask
),
3262 .nodemask
= nodemask
,
3263 .migratetype
= gfpflags_to_migratetype(gfp_mask
),
3266 gfp_mask
&= gfp_allowed_mask
;
3268 lockdep_trace_alloc(gfp_mask
);
3270 might_sleep_if(gfp_mask
& __GFP_DIRECT_RECLAIM
);
3272 if (should_fail_alloc_page(gfp_mask
, order
))
3276 * Check the zones suitable for the gfp_mask contain at least one
3277 * valid zone. It's possible to have an empty zonelist as a result
3278 * of __GFP_THISNODE and a memoryless node
3280 if (unlikely(!zonelist
->_zonerefs
->zone
))
3283 if (IS_ENABLED(CONFIG_CMA
) && ac
.migratetype
== MIGRATE_MOVABLE
)
3284 alloc_flags
|= ALLOC_CMA
;
3287 cpuset_mems_cookie
= read_mems_allowed_begin();
3289 /* We set it here, as __alloc_pages_slowpath might have changed it */
3290 ac
.zonelist
= zonelist
;
3292 /* Dirty zone balancing only done in the fast path */
3293 ac
.spread_dirty_pages
= (gfp_mask
& __GFP_WRITE
);
3295 /* The preferred zone is used for statistics later */
3296 preferred_zoneref
= first_zones_zonelist(ac
.zonelist
, ac
.high_zoneidx
,
3297 ac
.nodemask
? : &cpuset_current_mems_allowed
,
3298 &ac
.preferred_zone
);
3299 if (!ac
.preferred_zone
)
3301 ac
.classzone_idx
= zonelist_zone_idx(preferred_zoneref
);
3303 /* First allocation attempt */
3304 alloc_mask
= gfp_mask
|__GFP_HARDWALL
;
3305 page
= get_page_from_freelist(alloc_mask
, order
, alloc_flags
, &ac
);
3306 if (unlikely(!page
)) {
3308 * Runtime PM, block IO and its error handling path
3309 * can deadlock because I/O on the device might not
3312 alloc_mask
= memalloc_noio_flags(gfp_mask
);
3313 ac
.spread_dirty_pages
= false;
3315 page
= __alloc_pages_slowpath(alloc_mask
, order
, &ac
);
3318 if (kmemcheck_enabled
&& page
)
3319 kmemcheck_pagealloc_alloc(page
, order
, gfp_mask
);
3321 trace_mm_page_alloc(page
, order
, alloc_mask
, ac
.migratetype
);
3325 * When updating a task's mems_allowed, it is possible to race with
3326 * parallel threads in such a way that an allocation can fail while
3327 * the mask is being updated. If a page allocation is about to fail,
3328 * check if the cpuset changed during allocation and if so, retry.
3330 if (unlikely(!page
&& read_mems_allowed_retry(cpuset_mems_cookie
)))
3335 EXPORT_SYMBOL(__alloc_pages_nodemask
);
3338 * Common helper functions.
3340 unsigned long __get_free_pages(gfp_t gfp_mask
, unsigned int order
)
3345 * __get_free_pages() returns a 32-bit address, which cannot represent
3348 VM_BUG_ON((gfp_mask
& __GFP_HIGHMEM
) != 0);
3350 page
= alloc_pages(gfp_mask
, order
);
3353 return (unsigned long) page_address(page
);
3355 EXPORT_SYMBOL(__get_free_pages
);
3357 unsigned long get_zeroed_page(gfp_t gfp_mask
)
3359 return __get_free_pages(gfp_mask
| __GFP_ZERO
, 0);
3361 EXPORT_SYMBOL(get_zeroed_page
);
3363 void __free_pages(struct page
*page
, unsigned int order
)
3365 if (put_page_testzero(page
)) {
3367 free_hot_cold_page(page
, false);
3369 __free_pages_ok(page
, order
);
3373 EXPORT_SYMBOL(__free_pages
);
3375 void free_pages(unsigned long addr
, unsigned int order
)
3378 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3379 __free_pages(virt_to_page((void *)addr
), order
);
3383 EXPORT_SYMBOL(free_pages
);
3387 * An arbitrary-length arbitrary-offset area of memory which resides
3388 * within a 0 or higher order page. Multiple fragments within that page
3389 * are individually refcounted, in the page's reference counter.
3391 * The page_frag functions below provide a simple allocation framework for
3392 * page fragments. This is used by the network stack and network device
3393 * drivers to provide a backing region of memory for use as either an
3394 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
3396 static struct page
*__page_frag_refill(struct page_frag_cache
*nc
,
3399 struct page
*page
= NULL
;
3400 gfp_t gfp
= gfp_mask
;
3402 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3403 gfp_mask
|= __GFP_COMP
| __GFP_NOWARN
| __GFP_NORETRY
|
3405 page
= alloc_pages_node(NUMA_NO_NODE
, gfp_mask
,
3406 PAGE_FRAG_CACHE_MAX_ORDER
);
3407 nc
->size
= page
? PAGE_FRAG_CACHE_MAX_SIZE
: PAGE_SIZE
;
3409 if (unlikely(!page
))
3410 page
= alloc_pages_node(NUMA_NO_NODE
, gfp
, 0);
3412 nc
->va
= page
? page_address(page
) : NULL
;
3417 void *__alloc_page_frag(struct page_frag_cache
*nc
,
3418 unsigned int fragsz
, gfp_t gfp_mask
)
3420 unsigned int size
= PAGE_SIZE
;
3424 if (unlikely(!nc
->va
)) {
3426 page
= __page_frag_refill(nc
, gfp_mask
);
3430 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3431 /* if size can vary use size else just use PAGE_SIZE */
3434 /* Even if we own the page, we do not use atomic_set().
3435 * This would break get_page_unless_zero() users.
3437 atomic_add(size
- 1, &page
->_count
);
3439 /* reset page count bias and offset to start of new frag */
3440 nc
->pfmemalloc
= page_is_pfmemalloc(page
);
3441 nc
->pagecnt_bias
= size
;
3445 offset
= nc
->offset
- fragsz
;
3446 if (unlikely(offset
< 0)) {
3447 page
= virt_to_page(nc
->va
);
3449 if (!atomic_sub_and_test(nc
->pagecnt_bias
, &page
->_count
))
3452 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
3453 /* if size can vary use size else just use PAGE_SIZE */
3456 /* OK, page count is 0, we can safely set it */
3457 atomic_set(&page
->_count
, size
);
3459 /* reset page count bias and offset to start of new frag */
3460 nc
->pagecnt_bias
= size
;
3461 offset
= size
- fragsz
;
3465 nc
->offset
= offset
;
3467 return nc
->va
+ offset
;
3469 EXPORT_SYMBOL(__alloc_page_frag
);
3472 * Frees a page fragment allocated out of either a compound or order 0 page.
3474 void __free_page_frag(void *addr
)
3476 struct page
*page
= virt_to_head_page(addr
);
3478 if (unlikely(put_page_testzero(page
)))
3479 __free_pages_ok(page
, compound_order(page
));
3481 EXPORT_SYMBOL(__free_page_frag
);
3484 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter
3485 * of the current memory cgroup.
3487 * It should be used when the caller would like to use kmalloc, but since the
3488 * allocation is large, it has to fall back to the page allocator.
3490 struct page
*alloc_kmem_pages(gfp_t gfp_mask
, unsigned int order
)
3494 page
= alloc_pages(gfp_mask
, order
);
3495 if (page
&& memcg_kmem_charge(page
, gfp_mask
, order
) != 0) {
3496 __free_pages(page
, order
);
3502 struct page
*alloc_kmem_pages_node(int nid
, gfp_t gfp_mask
, unsigned int order
)
3506 page
= alloc_pages_node(nid
, gfp_mask
, order
);
3507 if (page
&& memcg_kmem_charge(page
, gfp_mask
, order
) != 0) {
3508 __free_pages(page
, order
);
3515 * __free_kmem_pages and free_kmem_pages will free pages allocated with
3518 void __free_kmem_pages(struct page
*page
, unsigned int order
)
3520 memcg_kmem_uncharge(page
, order
);
3521 __free_pages(page
, order
);
3524 void free_kmem_pages(unsigned long addr
, unsigned int order
)
3527 VM_BUG_ON(!virt_addr_valid((void *)addr
));
3528 __free_kmem_pages(virt_to_page((void *)addr
), order
);
3532 static void *make_alloc_exact(unsigned long addr
, unsigned int order
,
3536 unsigned long alloc_end
= addr
+ (PAGE_SIZE
<< order
);
3537 unsigned long used
= addr
+ PAGE_ALIGN(size
);
3539 split_page(virt_to_page((void *)addr
), order
);
3540 while (used
< alloc_end
) {
3545 return (void *)addr
;
3549 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
3550 * @size: the number of bytes to allocate
3551 * @gfp_mask: GFP flags for the allocation
3553 * This function is similar to alloc_pages(), except that it allocates the
3554 * minimum number of pages to satisfy the request. alloc_pages() can only
3555 * allocate memory in power-of-two pages.
3557 * This function is also limited by MAX_ORDER.
3559 * Memory allocated by this function must be released by free_pages_exact().
3561 void *alloc_pages_exact(size_t size
, gfp_t gfp_mask
)
3563 unsigned int order
= get_order(size
);
3566 addr
= __get_free_pages(gfp_mask
, order
);
3567 return make_alloc_exact(addr
, order
, size
);
3569 EXPORT_SYMBOL(alloc_pages_exact
);
3572 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
3574 * @nid: the preferred node ID where memory should be allocated
3575 * @size: the number of bytes to allocate
3576 * @gfp_mask: GFP flags for the allocation
3578 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
3581 void * __meminit
alloc_pages_exact_nid(int nid
, size_t size
, gfp_t gfp_mask
)
3583 unsigned int order
= get_order(size
);
3584 struct page
*p
= alloc_pages_node(nid
, gfp_mask
, order
);
3587 return make_alloc_exact((unsigned long)page_address(p
), order
, size
);
3591 * free_pages_exact - release memory allocated via alloc_pages_exact()
3592 * @virt: the value returned by alloc_pages_exact.
3593 * @size: size of allocation, same value as passed to alloc_pages_exact().
3595 * Release the memory allocated by a previous call to alloc_pages_exact.
3597 void free_pages_exact(void *virt
, size_t size
)
3599 unsigned long addr
= (unsigned long)virt
;
3600 unsigned long end
= addr
+ PAGE_ALIGN(size
);
3602 while (addr
< end
) {
3607 EXPORT_SYMBOL(free_pages_exact
);
3610 * nr_free_zone_pages - count number of pages beyond high watermark
3611 * @offset: The zone index of the highest zone
3613 * nr_free_zone_pages() counts the number of counts pages which are beyond the
3614 * high watermark within all zones at or below a given zone index. For each
3615 * zone, the number of pages is calculated as:
3616 * managed_pages - high_pages
3618 static unsigned long nr_free_zone_pages(int offset
)
3623 /* Just pick one node, since fallback list is circular */
3624 unsigned long sum
= 0;
3626 struct zonelist
*zonelist
= node_zonelist(numa_node_id(), GFP_KERNEL
);
3628 for_each_zone_zonelist(zone
, z
, zonelist
, offset
) {
3629 unsigned long size
= zone
->managed_pages
;
3630 unsigned long high
= high_wmark_pages(zone
);
3639 * nr_free_buffer_pages - count number of pages beyond high watermark
3641 * nr_free_buffer_pages() counts the number of pages which are beyond the high
3642 * watermark within ZONE_DMA and ZONE_NORMAL.
3644 unsigned long nr_free_buffer_pages(void)
3646 return nr_free_zone_pages(gfp_zone(GFP_USER
));
3648 EXPORT_SYMBOL_GPL(nr_free_buffer_pages
);
3651 * nr_free_pagecache_pages - count number of pages beyond high watermark
3653 * nr_free_pagecache_pages() counts the number of pages which are beyond the
3654 * high watermark within all zones.
3656 unsigned long nr_free_pagecache_pages(void)
3658 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE
));
3661 static inline void show_node(struct zone
*zone
)
3663 if (IS_ENABLED(CONFIG_NUMA
))
3664 printk("Node %d ", zone_to_nid(zone
));
3667 void si_meminfo(struct sysinfo
*val
)
3669 val
->totalram
= totalram_pages
;
3670 val
->sharedram
= global_page_state(NR_SHMEM
);
3671 val
->freeram
= global_page_state(NR_FREE_PAGES
);
3672 val
->bufferram
= nr_blockdev_pages();
3673 val
->totalhigh
= totalhigh_pages
;
3674 val
->freehigh
= nr_free_highpages();
3675 val
->mem_unit
= PAGE_SIZE
;
3678 EXPORT_SYMBOL(si_meminfo
);
3681 void si_meminfo_node(struct sysinfo
*val
, int nid
)
3683 int zone_type
; /* needs to be signed */
3684 unsigned long managed_pages
= 0;
3685 pg_data_t
*pgdat
= NODE_DATA(nid
);
3687 for (zone_type
= 0; zone_type
< MAX_NR_ZONES
; zone_type
++)
3688 managed_pages
+= pgdat
->node_zones
[zone_type
].managed_pages
;
3689 val
->totalram
= managed_pages
;
3690 val
->sharedram
= node_page_state(nid
, NR_SHMEM
);
3691 val
->freeram
= node_page_state(nid
, NR_FREE_PAGES
);
3692 #ifdef CONFIG_HIGHMEM
3693 val
->totalhigh
= pgdat
->node_zones
[ZONE_HIGHMEM
].managed_pages
;
3694 val
->freehigh
= zone_page_state(&pgdat
->node_zones
[ZONE_HIGHMEM
],
3700 val
->mem_unit
= PAGE_SIZE
;
3705 * Determine whether the node should be displayed or not, depending on whether
3706 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
3708 bool skip_free_areas_node(unsigned int flags
, int nid
)
3711 unsigned int cpuset_mems_cookie
;
3713 if (!(flags
& SHOW_MEM_FILTER_NODES
))
3717 cpuset_mems_cookie
= read_mems_allowed_begin();
3718 ret
= !node_isset(nid
, cpuset_current_mems_allowed
);
3719 } while (read_mems_allowed_retry(cpuset_mems_cookie
));
3724 #define K(x) ((x) << (PAGE_SHIFT-10))
3726 static void show_migration_types(unsigned char type
)
3728 static const char types
[MIGRATE_TYPES
] = {
3729 [MIGRATE_UNMOVABLE
] = 'U',
3730 [MIGRATE_MOVABLE
] = 'M',
3731 [MIGRATE_RECLAIMABLE
] = 'E',
3732 [MIGRATE_HIGHATOMIC
] = 'H',
3734 [MIGRATE_CMA
] = 'C',
3736 #ifdef CONFIG_MEMORY_ISOLATION
3737 [MIGRATE_ISOLATE
] = 'I',
3740 char tmp
[MIGRATE_TYPES
+ 1];
3744 for (i
= 0; i
< MIGRATE_TYPES
; i
++) {
3745 if (type
& (1 << i
))
3750 printk("(%s) ", tmp
);
3754 * Show free area list (used inside shift_scroll-lock stuff)
3755 * We also calculate the percentage fragmentation. We do this by counting the
3756 * memory on each free list with the exception of the first item on the list.
3759 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
3762 void show_free_areas(unsigned int filter
)
3764 unsigned long free_pcp
= 0;
3768 for_each_populated_zone(zone
) {
3769 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3772 for_each_online_cpu(cpu
)
3773 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
3776 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
3777 " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
3778 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n"
3779 " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
3780 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
3781 " free:%lu free_pcp:%lu free_cma:%lu\n",
3782 global_page_state(NR_ACTIVE_ANON
),
3783 global_page_state(NR_INACTIVE_ANON
),
3784 global_page_state(NR_ISOLATED_ANON
),
3785 global_page_state(NR_ACTIVE_FILE
),
3786 global_page_state(NR_INACTIVE_FILE
),
3787 global_page_state(NR_ISOLATED_FILE
),
3788 global_page_state(NR_UNEVICTABLE
),
3789 global_page_state(NR_FILE_DIRTY
),
3790 global_page_state(NR_WRITEBACK
),
3791 global_page_state(NR_UNSTABLE_NFS
),
3792 global_page_state(NR_SLAB_RECLAIMABLE
),
3793 global_page_state(NR_SLAB_UNRECLAIMABLE
),
3794 global_page_state(NR_FILE_MAPPED
),
3795 global_page_state(NR_SHMEM
),
3796 global_page_state(NR_PAGETABLE
),
3797 global_page_state(NR_BOUNCE
),
3798 global_page_state(NR_FREE_PAGES
),
3800 global_page_state(NR_FREE_CMA_PAGES
));
3802 for_each_populated_zone(zone
) {
3805 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3809 for_each_online_cpu(cpu
)
3810 free_pcp
+= per_cpu_ptr(zone
->pageset
, cpu
)->pcp
.count
;
3818 " active_anon:%lukB"
3819 " inactive_anon:%lukB"
3820 " active_file:%lukB"
3821 " inactive_file:%lukB"
3822 " unevictable:%lukB"
3823 " isolated(anon):%lukB"
3824 " isolated(file):%lukB"
3832 " slab_reclaimable:%lukB"
3833 " slab_unreclaimable:%lukB"
3834 " kernel_stack:%lukB"
3841 " writeback_tmp:%lukB"
3842 " pages_scanned:%lu"
3843 " all_unreclaimable? %s"
3846 K(zone_page_state(zone
, NR_FREE_PAGES
)),
3847 K(min_wmark_pages(zone
)),
3848 K(low_wmark_pages(zone
)),
3849 K(high_wmark_pages(zone
)),
3850 K(zone_page_state(zone
, NR_ACTIVE_ANON
)),
3851 K(zone_page_state(zone
, NR_INACTIVE_ANON
)),
3852 K(zone_page_state(zone
, NR_ACTIVE_FILE
)),
3853 K(zone_page_state(zone
, NR_INACTIVE_FILE
)),
3854 K(zone_page_state(zone
, NR_UNEVICTABLE
)),
3855 K(zone_page_state(zone
, NR_ISOLATED_ANON
)),
3856 K(zone_page_state(zone
, NR_ISOLATED_FILE
)),
3857 K(zone
->present_pages
),
3858 K(zone
->managed_pages
),
3859 K(zone_page_state(zone
, NR_MLOCK
)),
3860 K(zone_page_state(zone
, NR_FILE_DIRTY
)),
3861 K(zone_page_state(zone
, NR_WRITEBACK
)),
3862 K(zone_page_state(zone
, NR_FILE_MAPPED
)),
3863 K(zone_page_state(zone
, NR_SHMEM
)),
3864 K(zone_page_state(zone
, NR_SLAB_RECLAIMABLE
)),
3865 K(zone_page_state(zone
, NR_SLAB_UNRECLAIMABLE
)),
3866 zone_page_state(zone
, NR_KERNEL_STACK
) *
3868 K(zone_page_state(zone
, NR_PAGETABLE
)),
3869 K(zone_page_state(zone
, NR_UNSTABLE_NFS
)),
3870 K(zone_page_state(zone
, NR_BOUNCE
)),
3872 K(this_cpu_read(zone
->pageset
->pcp
.count
)),
3873 K(zone_page_state(zone
, NR_FREE_CMA_PAGES
)),
3874 K(zone_page_state(zone
, NR_WRITEBACK_TEMP
)),
3875 K(zone_page_state(zone
, NR_PAGES_SCANNED
)),
3876 (!zone_reclaimable(zone
) ? "yes" : "no")
3878 printk("lowmem_reserve[]:");
3879 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
3880 printk(" %ld", zone
->lowmem_reserve
[i
]);
3884 for_each_populated_zone(zone
) {
3886 unsigned long nr
[MAX_ORDER
], flags
, total
= 0;
3887 unsigned char types
[MAX_ORDER
];
3889 if (skip_free_areas_node(filter
, zone_to_nid(zone
)))
3892 printk("%s: ", zone
->name
);
3894 spin_lock_irqsave(&zone
->lock
, flags
);
3895 for (order
= 0; order
< MAX_ORDER
; order
++) {
3896 struct free_area
*area
= &zone
->free_area
[order
];
3899 nr
[order
] = area
->nr_free
;
3900 total
+= nr
[order
] << order
;
3903 for (type
= 0; type
< MIGRATE_TYPES
; type
++) {
3904 if (!list_empty(&area
->free_list
[type
]))
3905 types
[order
] |= 1 << type
;
3908 spin_unlock_irqrestore(&zone
->lock
, flags
);
3909 for (order
= 0; order
< MAX_ORDER
; order
++) {
3910 printk("%lu*%lukB ", nr
[order
], K(1UL) << order
);
3912 show_migration_types(types
[order
]);
3914 printk("= %lukB\n", K(total
));
3917 hugetlb_show_meminfo();
3919 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES
));
3921 show_swap_cache_info();
3924 static void zoneref_set_zone(struct zone
*zone
, struct zoneref
*zoneref
)
3926 zoneref
->zone
= zone
;
3927 zoneref
->zone_idx
= zone_idx(zone
);
3931 * Builds allocation fallback zone lists.
3933 * Add all populated zones of a node to the zonelist.
3935 static int build_zonelists_node(pg_data_t
*pgdat
, struct zonelist
*zonelist
,
3939 enum zone_type zone_type
= MAX_NR_ZONES
;
3943 zone
= pgdat
->node_zones
+ zone_type
;
3944 if (populated_zone(zone
)) {
3945 zoneref_set_zone(zone
,
3946 &zonelist
->_zonerefs
[nr_zones
++]);
3947 check_highest_zone(zone_type
);
3949 } while (zone_type
);
3957 * 0 = automatic detection of better ordering.
3958 * 1 = order by ([node] distance, -zonetype)
3959 * 2 = order by (-zonetype, [node] distance)
3961 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
3962 * the same zonelist. So only NUMA can configure this param.
3964 #define ZONELIST_ORDER_DEFAULT 0
3965 #define ZONELIST_ORDER_NODE 1
3966 #define ZONELIST_ORDER_ZONE 2
3968 /* zonelist order in the kernel.
3969 * set_zonelist_order() will set this to NODE or ZONE.
3971 static int current_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3972 static char zonelist_order_name
[3][8] = {"Default", "Node", "Zone"};
3976 /* The value user specified ....changed by config */
3977 static int user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3978 /* string for sysctl */
3979 #define NUMA_ZONELIST_ORDER_LEN 16
3980 char numa_zonelist_order
[16] = "default";
3983 * interface for configure zonelist ordering.
3984 * command line option "numa_zonelist_order"
3985 * = "[dD]efault - default, automatic configuration.
3986 * = "[nN]ode - order by node locality, then by zone within node
3987 * = "[zZ]one - order by zone, then by locality within zone
3990 static int __parse_numa_zonelist_order(char *s
)
3992 if (*s
== 'd' || *s
== 'D') {
3993 user_zonelist_order
= ZONELIST_ORDER_DEFAULT
;
3994 } else if (*s
== 'n' || *s
== 'N') {
3995 user_zonelist_order
= ZONELIST_ORDER_NODE
;
3996 } else if (*s
== 'z' || *s
== 'Z') {
3997 user_zonelist_order
= ZONELIST_ORDER_ZONE
;
4000 "Ignoring invalid numa_zonelist_order value: "
4007 static __init
int setup_numa_zonelist_order(char *s
)
4014 ret
= __parse_numa_zonelist_order(s
);
4016 strlcpy(numa_zonelist_order
, s
, NUMA_ZONELIST_ORDER_LEN
);
4020 early_param("numa_zonelist_order", setup_numa_zonelist_order
);
4023 * sysctl handler for numa_zonelist_order
4025 int numa_zonelist_order_handler(struct ctl_table
*table
, int write
,
4026 void __user
*buffer
, size_t *length
,
4029 char saved_string
[NUMA_ZONELIST_ORDER_LEN
];
4031 static DEFINE_MUTEX(zl_order_mutex
);
4033 mutex_lock(&zl_order_mutex
);
4035 if (strlen((char *)table
->data
) >= NUMA_ZONELIST_ORDER_LEN
) {
4039 strcpy(saved_string
, (char *)table
->data
);
4041 ret
= proc_dostring(table
, write
, buffer
, length
, ppos
);
4045 int oldval
= user_zonelist_order
;
4047 ret
= __parse_numa_zonelist_order((char *)table
->data
);
4050 * bogus value. restore saved string
4052 strncpy((char *)table
->data
, saved_string
,
4053 NUMA_ZONELIST_ORDER_LEN
);
4054 user_zonelist_order
= oldval
;
4055 } else if (oldval
!= user_zonelist_order
) {
4056 mutex_lock(&zonelists_mutex
);
4057 build_all_zonelists(NULL
, NULL
);
4058 mutex_unlock(&zonelists_mutex
);
4062 mutex_unlock(&zl_order_mutex
);
4067 #define MAX_NODE_LOAD (nr_online_nodes)
4068 static int node_load
[MAX_NUMNODES
];
4071 * find_next_best_node - find the next node that should appear in a given node's fallback list
4072 * @node: node whose fallback list we're appending
4073 * @used_node_mask: nodemask_t of already used nodes
4075 * We use a number of factors to determine which is the next node that should
4076 * appear on a given node's fallback list. The node should not have appeared
4077 * already in @node's fallback list, and it should be the next closest node
4078 * according to the distance array (which contains arbitrary distance values
4079 * from each node to each node in the system), and should also prefer nodes
4080 * with no CPUs, since presumably they'll have very little allocation pressure
4081 * on them otherwise.
4082 * It returns -1 if no node is found.
4084 static int find_next_best_node(int node
, nodemask_t
*used_node_mask
)
4087 int min_val
= INT_MAX
;
4088 int best_node
= NUMA_NO_NODE
;
4089 const struct cpumask
*tmp
= cpumask_of_node(0);
4091 /* Use the local node if we haven't already */
4092 if (!node_isset(node
, *used_node_mask
)) {
4093 node_set(node
, *used_node_mask
);
4097 for_each_node_state(n
, N_MEMORY
) {
4099 /* Don't want a node to appear more than once */
4100 if (node_isset(n
, *used_node_mask
))
4103 /* Use the distance array to find the distance */
4104 val
= node_distance(node
, n
);
4106 /* Penalize nodes under us ("prefer the next node") */
4109 /* Give preference to headless and unused nodes */
4110 tmp
= cpumask_of_node(n
);
4111 if (!cpumask_empty(tmp
))
4112 val
+= PENALTY_FOR_NODE_WITH_CPUS
;
4114 /* Slight preference for less loaded node */
4115 val
*= (MAX_NODE_LOAD
*MAX_NUMNODES
);
4116 val
+= node_load
[n
];
4118 if (val
< min_val
) {
4125 node_set(best_node
, *used_node_mask
);
4132 * Build zonelists ordered by node and zones within node.
4133 * This results in maximum locality--normal zone overflows into local
4134 * DMA zone, if any--but risks exhausting DMA zone.
4136 static void build_zonelists_in_node_order(pg_data_t
*pgdat
, int node
)
4139 struct zonelist
*zonelist
;
4141 zonelist
= &pgdat
->node_zonelists
[0];
4142 for (j
= 0; zonelist
->_zonerefs
[j
].zone
!= NULL
; j
++)
4144 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4145 zonelist
->_zonerefs
[j
].zone
= NULL
;
4146 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4150 * Build gfp_thisnode zonelists
4152 static void build_thisnode_zonelists(pg_data_t
*pgdat
)
4155 struct zonelist
*zonelist
;
4157 zonelist
= &pgdat
->node_zonelists
[1];
4158 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4159 zonelist
->_zonerefs
[j
].zone
= NULL
;
4160 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4164 * Build zonelists ordered by zone and nodes within zones.
4165 * This results in conserving DMA zone[s] until all Normal memory is
4166 * exhausted, but results in overflowing to remote node while memory
4167 * may still exist in local DMA zone.
4169 static int node_order
[MAX_NUMNODES
];
4171 static void build_zonelists_in_zone_order(pg_data_t
*pgdat
, int nr_nodes
)
4174 int zone_type
; /* needs to be signed */
4176 struct zonelist
*zonelist
;
4178 zonelist
= &pgdat
->node_zonelists
[0];
4180 for (zone_type
= MAX_NR_ZONES
- 1; zone_type
>= 0; zone_type
--) {
4181 for (j
= 0; j
< nr_nodes
; j
++) {
4182 node
= node_order
[j
];
4183 z
= &NODE_DATA(node
)->node_zones
[zone_type
];
4184 if (populated_zone(z
)) {
4186 &zonelist
->_zonerefs
[pos
++]);
4187 check_highest_zone(zone_type
);
4191 zonelist
->_zonerefs
[pos
].zone
= NULL
;
4192 zonelist
->_zonerefs
[pos
].zone_idx
= 0;
4195 #if defined(CONFIG_64BIT)
4197 * Devices that require DMA32/DMA are relatively rare and do not justify a
4198 * penalty to every machine in case the specialised case applies. Default
4199 * to Node-ordering on 64-bit NUMA machines
4201 static int default_zonelist_order(void)
4203 return ZONELIST_ORDER_NODE
;
4207 * On 32-bit, the Normal zone needs to be preserved for allocations accessible
4208 * by the kernel. If processes running on node 0 deplete the low memory zone
4209 * then reclaim will occur more frequency increasing stalls and potentially
4210 * be easier to OOM if a large percentage of the zone is under writeback or
4211 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
4212 * Hence, default to zone ordering on 32-bit.
4214 static int default_zonelist_order(void)
4216 return ZONELIST_ORDER_ZONE
;
4218 #endif /* CONFIG_64BIT */
4220 static void set_zonelist_order(void)
4222 if (user_zonelist_order
== ZONELIST_ORDER_DEFAULT
)
4223 current_zonelist_order
= default_zonelist_order();
4225 current_zonelist_order
= user_zonelist_order
;
4228 static void build_zonelists(pg_data_t
*pgdat
)
4232 nodemask_t used_mask
;
4233 int local_node
, prev_node
;
4234 struct zonelist
*zonelist
;
4235 unsigned int order
= current_zonelist_order
;
4237 /* initialize zonelists */
4238 for (i
= 0; i
< MAX_ZONELISTS
; i
++) {
4239 zonelist
= pgdat
->node_zonelists
+ i
;
4240 zonelist
->_zonerefs
[0].zone
= NULL
;
4241 zonelist
->_zonerefs
[0].zone_idx
= 0;
4244 /* NUMA-aware ordering of nodes */
4245 local_node
= pgdat
->node_id
;
4246 load
= nr_online_nodes
;
4247 prev_node
= local_node
;
4248 nodes_clear(used_mask
);
4250 memset(node_order
, 0, sizeof(node_order
));
4253 while ((node
= find_next_best_node(local_node
, &used_mask
)) >= 0) {
4255 * We don't want to pressure a particular node.
4256 * So adding penalty to the first node in same
4257 * distance group to make it round-robin.
4259 if (node_distance(local_node
, node
) !=
4260 node_distance(local_node
, prev_node
))
4261 node_load
[node
] = load
;
4265 if (order
== ZONELIST_ORDER_NODE
)
4266 build_zonelists_in_node_order(pgdat
, node
);
4268 node_order
[j
++] = node
; /* remember order */
4271 if (order
== ZONELIST_ORDER_ZONE
) {
4272 /* calculate node order -- i.e., DMA last! */
4273 build_zonelists_in_zone_order(pgdat
, j
);
4276 build_thisnode_zonelists(pgdat
);
4279 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4281 * Return node id of node used for "local" allocations.
4282 * I.e., first node id of first zone in arg node's generic zonelist.
4283 * Used for initializing percpu 'numa_mem', which is used primarily
4284 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
4286 int local_memory_node(int node
)
4290 (void)first_zones_zonelist(node_zonelist(node
, GFP_KERNEL
),
4291 gfp_zone(GFP_KERNEL
),
4298 #else /* CONFIG_NUMA */
4300 static void set_zonelist_order(void)
4302 current_zonelist_order
= ZONELIST_ORDER_ZONE
;
4305 static void build_zonelists(pg_data_t
*pgdat
)
4307 int node
, local_node
;
4309 struct zonelist
*zonelist
;
4311 local_node
= pgdat
->node_id
;
4313 zonelist
= &pgdat
->node_zonelists
[0];
4314 j
= build_zonelists_node(pgdat
, zonelist
, 0);
4317 * Now we build the zonelist so that it contains the zones
4318 * of all the other nodes.
4319 * We don't want to pressure a particular node, so when
4320 * building the zones for node N, we make sure that the
4321 * zones coming right after the local ones are those from
4322 * node N+1 (modulo N)
4324 for (node
= local_node
+ 1; node
< MAX_NUMNODES
; node
++) {
4325 if (!node_online(node
))
4327 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4329 for (node
= 0; node
< local_node
; node
++) {
4330 if (!node_online(node
))
4332 j
= build_zonelists_node(NODE_DATA(node
), zonelist
, j
);
4335 zonelist
->_zonerefs
[j
].zone
= NULL
;
4336 zonelist
->_zonerefs
[j
].zone_idx
= 0;
4339 #endif /* CONFIG_NUMA */
4342 * Boot pageset table. One per cpu which is going to be used for all
4343 * zones and all nodes. The parameters will be set in such a way
4344 * that an item put on a list will immediately be handed over to
4345 * the buddy list. This is safe since pageset manipulation is done
4346 * with interrupts disabled.
4348 * The boot_pagesets must be kept even after bootup is complete for
4349 * unused processors and/or zones. They do play a role for bootstrapping
4350 * hotplugged processors.
4352 * zoneinfo_show() and maybe other functions do
4353 * not check if the processor is online before following the pageset pointer.
4354 * Other parts of the kernel may not check if the zone is available.
4356 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
);
4357 static DEFINE_PER_CPU(struct per_cpu_pageset
, boot_pageset
);
4358 static void setup_zone_pageset(struct zone
*zone
);
4361 * Global mutex to protect against size modification of zonelists
4362 * as well as to serialize pageset setup for the new populated zone.
4364 DEFINE_MUTEX(zonelists_mutex
);
4366 /* return values int ....just for stop_machine() */
4367 static int __build_all_zonelists(void *data
)
4371 pg_data_t
*self
= data
;
4374 memset(node_load
, 0, sizeof(node_load
));
4377 if (self
&& !node_online(self
->node_id
)) {
4378 build_zonelists(self
);
4381 for_each_online_node(nid
) {
4382 pg_data_t
*pgdat
= NODE_DATA(nid
);
4384 build_zonelists(pgdat
);
4388 * Initialize the boot_pagesets that are going to be used
4389 * for bootstrapping processors. The real pagesets for
4390 * each zone will be allocated later when the per cpu
4391 * allocator is available.
4393 * boot_pagesets are used also for bootstrapping offline
4394 * cpus if the system is already booted because the pagesets
4395 * are needed to initialize allocators on a specific cpu too.
4396 * F.e. the percpu allocator needs the page allocator which
4397 * needs the percpu allocator in order to allocate its pagesets
4398 * (a chicken-egg dilemma).
4400 for_each_possible_cpu(cpu
) {
4401 setup_pageset(&per_cpu(boot_pageset
, cpu
), 0);
4403 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
4405 * We now know the "local memory node" for each node--
4406 * i.e., the node of the first zone in the generic zonelist.
4407 * Set up numa_mem percpu variable for on-line cpus. During
4408 * boot, only the boot cpu should be on-line; we'll init the
4409 * secondary cpus' numa_mem as they come on-line. During
4410 * node/memory hotplug, we'll fixup all on-line cpus.
4412 if (cpu_online(cpu
))
4413 set_cpu_numa_mem(cpu
, local_memory_node(cpu_to_node(cpu
)));
4420 static noinline
void __init
4421 build_all_zonelists_init(void)
4423 __build_all_zonelists(NULL
);
4424 mminit_verify_zonelist();
4425 cpuset_init_current_mems_allowed();
4429 * Called with zonelists_mutex held always
4430 * unless system_state == SYSTEM_BOOTING.
4432 * __ref due to (1) call of __meminit annotated setup_zone_pageset
4433 * [we're only called with non-NULL zone through __meminit paths] and
4434 * (2) call of __init annotated helper build_all_zonelists_init
4435 * [protected by SYSTEM_BOOTING].
4437 void __ref
build_all_zonelists(pg_data_t
*pgdat
, struct zone
*zone
)
4439 set_zonelist_order();
4441 if (system_state
== SYSTEM_BOOTING
) {
4442 build_all_zonelists_init();
4444 #ifdef CONFIG_MEMORY_HOTPLUG
4446 setup_zone_pageset(zone
);
4448 /* we have to stop all cpus to guarantee there is no user
4450 stop_machine(__build_all_zonelists
, pgdat
, NULL
);
4451 /* cpuset refresh routine should be here */
4453 vm_total_pages
= nr_free_pagecache_pages();
4455 * Disable grouping by mobility if the number of pages in the
4456 * system is too low to allow the mechanism to work. It would be
4457 * more accurate, but expensive to check per-zone. This check is
4458 * made on memory-hotadd so a system can start with mobility
4459 * disabled and enable it later
4461 if (vm_total_pages
< (pageblock_nr_pages
* MIGRATE_TYPES
))
4462 page_group_by_mobility_disabled
= 1;
4464 page_group_by_mobility_disabled
= 0;
4466 pr_info("Built %i zonelists in %s order, mobility grouping %s. "
4467 "Total pages: %ld\n",
4469 zonelist_order_name
[current_zonelist_order
],
4470 page_group_by_mobility_disabled
? "off" : "on",
4473 pr_info("Policy zone: %s\n", zone_names
[policy_zone
]);
4478 * Helper functions to size the waitqueue hash table.
4479 * Essentially these want to choose hash table sizes sufficiently
4480 * large so that collisions trying to wait on pages are rare.
4481 * But in fact, the number of active page waitqueues on typical
4482 * systems is ridiculously low, less than 200. So this is even
4483 * conservative, even though it seems large.
4485 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
4486 * waitqueues, i.e. the size of the waitq table given the number of pages.
4488 #define PAGES_PER_WAITQUEUE 256
4490 #ifndef CONFIG_MEMORY_HOTPLUG
4491 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
4493 unsigned long size
= 1;
4495 pages
/= PAGES_PER_WAITQUEUE
;
4497 while (size
< pages
)
4501 * Once we have dozens or even hundreds of threads sleeping
4502 * on IO we've got bigger problems than wait queue collision.
4503 * Limit the size of the wait table to a reasonable size.
4505 size
= min(size
, 4096UL);
4507 return max(size
, 4UL);
4511 * A zone's size might be changed by hot-add, so it is not possible to determine
4512 * a suitable size for its wait_table. So we use the maximum size now.
4514 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie:
4516 * i386 (preemption config) : 4096 x 16 = 64Kbyte.
4517 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
4518 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte.
4520 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
4521 * or more by the traditional way. (See above). It equals:
4523 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte.
4524 * ia64(16K page size) : = ( 8G + 4M)byte.
4525 * powerpc (64K page size) : = (32G +16M)byte.
4527 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages
)
4534 * This is an integer logarithm so that shifts can be used later
4535 * to extract the more random high bits from the multiplicative
4536 * hash function before the remainder is taken.
4538 static inline unsigned long wait_table_bits(unsigned long size
)
4544 * Initially all pages are reserved - free ones are freed
4545 * up by free_all_bootmem() once the early boot process is
4546 * done. Non-atomic initialization, single-pass.
4548 void __meminit
memmap_init_zone(unsigned long size
, int nid
, unsigned long zone
,
4549 unsigned long start_pfn
, enum memmap_context context
)
4551 pg_data_t
*pgdat
= NODE_DATA(nid
);
4552 unsigned long end_pfn
= start_pfn
+ size
;
4555 unsigned long nr_initialised
= 0;
4557 if (highest_memmap_pfn
< end_pfn
- 1)
4558 highest_memmap_pfn
= end_pfn
- 1;
4560 z
= &pgdat
->node_zones
[zone
];
4561 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
4563 * There can be holes in boot-time mem_map[]s
4564 * handed to this function. They do not
4565 * exist on hotplugged memory.
4567 if (context
== MEMMAP_EARLY
) {
4568 if (!early_pfn_valid(pfn
))
4570 if (!early_pfn_in_nid(pfn
, nid
))
4572 if (!update_defer_init(pgdat
, pfn
, end_pfn
,
4578 * Mark the block movable so that blocks are reserved for
4579 * movable at startup. This will force kernel allocations
4580 * to reserve their blocks rather than leaking throughout
4581 * the address space during boot when many long-lived
4582 * kernel allocations are made.
4584 * bitmap is created for zone's valid pfn range. but memmap
4585 * can be created for invalid pages (for alignment)
4586 * check here not to call set_pageblock_migratetype() against
4589 if (!(pfn
& (pageblock_nr_pages
- 1))) {
4590 struct page
*page
= pfn_to_page(pfn
);
4592 __init_single_page(page
, pfn
, zone
, nid
);
4593 set_pageblock_migratetype(page
, MIGRATE_MOVABLE
);
4595 __init_single_pfn(pfn
, zone
, nid
);
4600 static void __meminit
zone_init_free_lists(struct zone
*zone
)
4602 unsigned int order
, t
;
4603 for_each_migratetype_order(order
, t
) {
4604 INIT_LIST_HEAD(&zone
->free_area
[order
].free_list
[t
]);
4605 zone
->free_area
[order
].nr_free
= 0;
4609 #ifndef __HAVE_ARCH_MEMMAP_INIT
4610 #define memmap_init(size, nid, zone, start_pfn) \
4611 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
4614 static int zone_batchsize(struct zone
*zone
)
4620 * The per-cpu-pages pools are set to around 1000th of the
4621 * size of the zone. But no more than 1/2 of a meg.
4623 * OK, so we don't know how big the cache is. So guess.
4625 batch
= zone
->managed_pages
/ 1024;
4626 if (batch
* PAGE_SIZE
> 512 * 1024)
4627 batch
= (512 * 1024) / PAGE_SIZE
;
4628 batch
/= 4; /* We effectively *= 4 below */
4633 * Clamp the batch to a 2^n - 1 value. Having a power
4634 * of 2 value was found to be more likely to have
4635 * suboptimal cache aliasing properties in some cases.
4637 * For example if 2 tasks are alternately allocating
4638 * batches of pages, one task can end up with a lot
4639 * of pages of one half of the possible page colors
4640 * and the other with pages of the other colors.
4642 batch
= rounddown_pow_of_two(batch
+ batch
/2) - 1;
4647 /* The deferral and batching of frees should be suppressed under NOMMU
4650 * The problem is that NOMMU needs to be able to allocate large chunks
4651 * of contiguous memory as there's no hardware page translation to
4652 * assemble apparent contiguous memory from discontiguous pages.
4654 * Queueing large contiguous runs of pages for batching, however,
4655 * causes the pages to actually be freed in smaller chunks. As there
4656 * can be a significant delay between the individual batches being
4657 * recycled, this leads to the once large chunks of space being
4658 * fragmented and becoming unavailable for high-order allocations.
4665 * pcp->high and pcp->batch values are related and dependent on one another:
4666 * ->batch must never be higher then ->high.
4667 * The following function updates them in a safe manner without read side
4670 * Any new users of pcp->batch and pcp->high should ensure they can cope with
4671 * those fields changing asynchronously (acording the the above rule).
4673 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function
4674 * outside of boot time (or some other assurance that no concurrent updaters
4677 static void pageset_update(struct per_cpu_pages
*pcp
, unsigned long high
,
4678 unsigned long batch
)
4680 /* start with a fail safe value for batch */
4684 /* Update high, then batch, in order */
4691 /* a companion to pageset_set_high() */
4692 static void pageset_set_batch(struct per_cpu_pageset
*p
, unsigned long batch
)
4694 pageset_update(&p
->pcp
, 6 * batch
, max(1UL, 1 * batch
));
4697 static void pageset_init(struct per_cpu_pageset
*p
)
4699 struct per_cpu_pages
*pcp
;
4702 memset(p
, 0, sizeof(*p
));
4706 for (migratetype
= 0; migratetype
< MIGRATE_PCPTYPES
; migratetype
++)
4707 INIT_LIST_HEAD(&pcp
->lists
[migratetype
]);
4710 static void setup_pageset(struct per_cpu_pageset
*p
, unsigned long batch
)
4713 pageset_set_batch(p
, batch
);
4717 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist
4718 * to the value high for the pageset p.
4720 static void pageset_set_high(struct per_cpu_pageset
*p
,
4723 unsigned long batch
= max(1UL, high
/ 4);
4724 if ((high
/ 4) > (PAGE_SHIFT
* 8))
4725 batch
= PAGE_SHIFT
* 8;
4727 pageset_update(&p
->pcp
, high
, batch
);
4730 static void pageset_set_high_and_batch(struct zone
*zone
,
4731 struct per_cpu_pageset
*pcp
)
4733 if (percpu_pagelist_fraction
)
4734 pageset_set_high(pcp
,
4735 (zone
->managed_pages
/
4736 percpu_pagelist_fraction
));
4738 pageset_set_batch(pcp
, zone_batchsize(zone
));
4741 static void __meminit
zone_pageset_init(struct zone
*zone
, int cpu
)
4743 struct per_cpu_pageset
*pcp
= per_cpu_ptr(zone
->pageset
, cpu
);
4746 pageset_set_high_and_batch(zone
, pcp
);
4749 static void __meminit
setup_zone_pageset(struct zone
*zone
)
4752 zone
->pageset
= alloc_percpu(struct per_cpu_pageset
);
4753 for_each_possible_cpu(cpu
)
4754 zone_pageset_init(zone
, cpu
);
4758 * Allocate per cpu pagesets and initialize them.
4759 * Before this call only boot pagesets were available.
4761 void __init
setup_per_cpu_pageset(void)
4765 for_each_populated_zone(zone
)
4766 setup_zone_pageset(zone
);
4769 static noinline __init_refok
4770 int zone_wait_table_init(struct zone
*zone
, unsigned long zone_size_pages
)
4776 * The per-page waitqueue mechanism uses hashed waitqueues
4779 zone
->wait_table_hash_nr_entries
=
4780 wait_table_hash_nr_entries(zone_size_pages
);
4781 zone
->wait_table_bits
=
4782 wait_table_bits(zone
->wait_table_hash_nr_entries
);
4783 alloc_size
= zone
->wait_table_hash_nr_entries
4784 * sizeof(wait_queue_head_t
);
4786 if (!slab_is_available()) {
4787 zone
->wait_table
= (wait_queue_head_t
*)
4788 memblock_virt_alloc_node_nopanic(
4789 alloc_size
, zone
->zone_pgdat
->node_id
);
4792 * This case means that a zone whose size was 0 gets new memory
4793 * via memory hot-add.
4794 * But it may be the case that a new node was hot-added. In
4795 * this case vmalloc() will not be able to use this new node's
4796 * memory - this wait_table must be initialized to use this new
4797 * node itself as well.
4798 * To use this new node's memory, further consideration will be
4801 zone
->wait_table
= vmalloc(alloc_size
);
4803 if (!zone
->wait_table
)
4806 for (i
= 0; i
< zone
->wait_table_hash_nr_entries
; ++i
)
4807 init_waitqueue_head(zone
->wait_table
+ i
);
4812 static __meminit
void zone_pcp_init(struct zone
*zone
)
4815 * per cpu subsystem is not up at this point. The following code
4816 * relies on the ability of the linker to provide the
4817 * offset of a (static) per cpu variable into the per cpu area.
4819 zone
->pageset
= &boot_pageset
;
4821 if (populated_zone(zone
))
4822 printk(KERN_DEBUG
" %s zone: %lu pages, LIFO batch:%u\n",
4823 zone
->name
, zone
->present_pages
,
4824 zone_batchsize(zone
));
4827 int __meminit
init_currently_empty_zone(struct zone
*zone
,
4828 unsigned long zone_start_pfn
,
4831 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
4833 ret
= zone_wait_table_init(zone
, size
);
4836 pgdat
->nr_zones
= zone_idx(zone
) + 1;
4838 zone
->zone_start_pfn
= zone_start_pfn
;
4840 mminit_dprintk(MMINIT_TRACE
, "memmap_init",
4841 "Initialising map node %d zone %lu pfns %lu -> %lu\n",
4843 (unsigned long)zone_idx(zone
),
4844 zone_start_pfn
, (zone_start_pfn
+ size
));
4846 zone_init_free_lists(zone
);
4851 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4852 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
4855 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
4857 int __meminit
__early_pfn_to_nid(unsigned long pfn
,
4858 struct mminit_pfnnid_cache
*state
)
4860 unsigned long start_pfn
, end_pfn
;
4863 if (state
->last_start
<= pfn
&& pfn
< state
->last_end
)
4864 return state
->last_nid
;
4866 nid
= memblock_search_pfn_nid(pfn
, &start_pfn
, &end_pfn
);
4868 state
->last_start
= start_pfn
;
4869 state
->last_end
= end_pfn
;
4870 state
->last_nid
= nid
;
4875 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
4878 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range
4879 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
4880 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid
4882 * If an architecture guarantees that all ranges registered contain no holes
4883 * and may be freed, this this function may be used instead of calling
4884 * memblock_free_early_nid() manually.
4886 void __init
free_bootmem_with_active_regions(int nid
, unsigned long max_low_pfn
)
4888 unsigned long start_pfn
, end_pfn
;
4891 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
) {
4892 start_pfn
= min(start_pfn
, max_low_pfn
);
4893 end_pfn
= min(end_pfn
, max_low_pfn
);
4895 if (start_pfn
< end_pfn
)
4896 memblock_free_early_nid(PFN_PHYS(start_pfn
),
4897 (end_pfn
- start_pfn
) << PAGE_SHIFT
,
4903 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4904 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4906 * If an architecture guarantees that all ranges registered contain no holes and may
4907 * be freed, this function may be used instead of calling memory_present() manually.
4909 void __init
sparse_memory_present_with_active_regions(int nid
)
4911 unsigned long start_pfn
, end_pfn
;
4914 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, &this_nid
)
4915 memory_present(this_nid
, start_pfn
, end_pfn
);
4919 * get_pfn_range_for_nid - Return the start and end page frames for a node
4920 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
4921 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
4922 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
4924 * It returns the start and end page frame of a node based on information
4925 * provided by memblock_set_node(). If called for a node
4926 * with no available memory, a warning is printed and the start and end
4929 void __meminit
get_pfn_range_for_nid(unsigned int nid
,
4930 unsigned long *start_pfn
, unsigned long *end_pfn
)
4932 unsigned long this_start_pfn
, this_end_pfn
;
4938 for_each_mem_pfn_range(i
, nid
, &this_start_pfn
, &this_end_pfn
, NULL
) {
4939 *start_pfn
= min(*start_pfn
, this_start_pfn
);
4940 *end_pfn
= max(*end_pfn
, this_end_pfn
);
4943 if (*start_pfn
== -1UL)
4948 * This finds a zone that can be used for ZONE_MOVABLE pages. The
4949 * assumption is made that zones within a node are ordered in monotonic
4950 * increasing memory addresses so that the "highest" populated zone is used
4952 static void __init
find_usable_zone_for_movable(void)
4955 for (zone_index
= MAX_NR_ZONES
- 1; zone_index
>= 0; zone_index
--) {
4956 if (zone_index
== ZONE_MOVABLE
)
4959 if (arch_zone_highest_possible_pfn
[zone_index
] >
4960 arch_zone_lowest_possible_pfn
[zone_index
])
4964 VM_BUG_ON(zone_index
== -1);
4965 movable_zone
= zone_index
;
4969 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
4970 * because it is sized independent of architecture. Unlike the other zones,
4971 * the starting point for ZONE_MOVABLE is not fixed. It may be different
4972 * in each node depending on the size of each node and how evenly kernelcore
4973 * is distributed. This helper function adjusts the zone ranges
4974 * provided by the architecture for a given node by using the end of the
4975 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
4976 * zones within a node are in order of monotonic increases memory addresses
4978 static void __meminit
adjust_zone_range_for_zone_movable(int nid
,
4979 unsigned long zone_type
,
4980 unsigned long node_start_pfn
,
4981 unsigned long node_end_pfn
,
4982 unsigned long *zone_start_pfn
,
4983 unsigned long *zone_end_pfn
)
4985 /* Only adjust if ZONE_MOVABLE is on this node */
4986 if (zone_movable_pfn
[nid
]) {
4987 /* Size ZONE_MOVABLE */
4988 if (zone_type
== ZONE_MOVABLE
) {
4989 *zone_start_pfn
= zone_movable_pfn
[nid
];
4990 *zone_end_pfn
= min(node_end_pfn
,
4991 arch_zone_highest_possible_pfn
[movable_zone
]);
4993 /* Adjust for ZONE_MOVABLE starting within this range */
4994 } else if (*zone_start_pfn
< zone_movable_pfn
[nid
] &&
4995 *zone_end_pfn
> zone_movable_pfn
[nid
]) {
4996 *zone_end_pfn
= zone_movable_pfn
[nid
];
4998 /* Check if this whole range is within ZONE_MOVABLE */
4999 } else if (*zone_start_pfn
>= zone_movable_pfn
[nid
])
5000 *zone_start_pfn
= *zone_end_pfn
;
5005 * Return the number of pages a zone spans in a node, including holes
5006 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
5008 static unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5009 unsigned long zone_type
,
5010 unsigned long node_start_pfn
,
5011 unsigned long node_end_pfn
,
5012 unsigned long *ignored
)
5014 unsigned long zone_start_pfn
, zone_end_pfn
;
5016 /* When hotadd a new node from cpu_up(), the node should be empty */
5017 if (!node_start_pfn
&& !node_end_pfn
)
5020 /* Get the start and end of the zone */
5021 zone_start_pfn
= arch_zone_lowest_possible_pfn
[zone_type
];
5022 zone_end_pfn
= arch_zone_highest_possible_pfn
[zone_type
];
5023 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5024 node_start_pfn
, node_end_pfn
,
5025 &zone_start_pfn
, &zone_end_pfn
);
5027 /* Check that this node has pages within the zone's required range */
5028 if (zone_end_pfn
< node_start_pfn
|| zone_start_pfn
> node_end_pfn
)
5031 /* Move the zone boundaries inside the node if necessary */
5032 zone_end_pfn
= min(zone_end_pfn
, node_end_pfn
);
5033 zone_start_pfn
= max(zone_start_pfn
, node_start_pfn
);
5035 /* Return the spanned pages */
5036 return zone_end_pfn
- zone_start_pfn
;
5040 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
5041 * then all holes in the requested range will be accounted for.
5043 unsigned long __meminit
__absent_pages_in_range(int nid
,
5044 unsigned long range_start_pfn
,
5045 unsigned long range_end_pfn
)
5047 unsigned long nr_absent
= range_end_pfn
- range_start_pfn
;
5048 unsigned long start_pfn
, end_pfn
;
5051 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5052 start_pfn
= clamp(start_pfn
, range_start_pfn
, range_end_pfn
);
5053 end_pfn
= clamp(end_pfn
, range_start_pfn
, range_end_pfn
);
5054 nr_absent
-= end_pfn
- start_pfn
;
5060 * absent_pages_in_range - Return number of page frames in holes within a range
5061 * @start_pfn: The start PFN to start searching for holes
5062 * @end_pfn: The end PFN to stop searching for holes
5064 * It returns the number of pages frames in memory holes within a range.
5066 unsigned long __init
absent_pages_in_range(unsigned long start_pfn
,
5067 unsigned long end_pfn
)
5069 return __absent_pages_in_range(MAX_NUMNODES
, start_pfn
, end_pfn
);
5072 /* Return the number of page frames in holes in a zone on a node */
5073 static unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5074 unsigned long zone_type
,
5075 unsigned long node_start_pfn
,
5076 unsigned long node_end_pfn
,
5077 unsigned long *ignored
)
5079 unsigned long zone_low
= arch_zone_lowest_possible_pfn
[zone_type
];
5080 unsigned long zone_high
= arch_zone_highest_possible_pfn
[zone_type
];
5081 unsigned long zone_start_pfn
, zone_end_pfn
;
5083 /* When hotadd a new node from cpu_up(), the node should be empty */
5084 if (!node_start_pfn
&& !node_end_pfn
)
5087 zone_start_pfn
= clamp(node_start_pfn
, zone_low
, zone_high
);
5088 zone_end_pfn
= clamp(node_end_pfn
, zone_low
, zone_high
);
5090 adjust_zone_range_for_zone_movable(nid
, zone_type
,
5091 node_start_pfn
, node_end_pfn
,
5092 &zone_start_pfn
, &zone_end_pfn
);
5093 return __absent_pages_in_range(nid
, zone_start_pfn
, zone_end_pfn
);
5096 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5097 static inline unsigned long __meminit
zone_spanned_pages_in_node(int nid
,
5098 unsigned long zone_type
,
5099 unsigned long node_start_pfn
,
5100 unsigned long node_end_pfn
,
5101 unsigned long *zones_size
)
5103 return zones_size
[zone_type
];
5106 static inline unsigned long __meminit
zone_absent_pages_in_node(int nid
,
5107 unsigned long zone_type
,
5108 unsigned long node_start_pfn
,
5109 unsigned long node_end_pfn
,
5110 unsigned long *zholes_size
)
5115 return zholes_size
[zone_type
];
5118 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5120 static void __meminit
calculate_node_totalpages(struct pglist_data
*pgdat
,
5121 unsigned long node_start_pfn
,
5122 unsigned long node_end_pfn
,
5123 unsigned long *zones_size
,
5124 unsigned long *zholes_size
)
5126 unsigned long realtotalpages
= 0, totalpages
= 0;
5129 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5130 struct zone
*zone
= pgdat
->node_zones
+ i
;
5131 unsigned long size
, real_size
;
5133 size
= zone_spanned_pages_in_node(pgdat
->node_id
, i
,
5137 real_size
= size
- zone_absent_pages_in_node(pgdat
->node_id
, i
,
5138 node_start_pfn
, node_end_pfn
,
5140 zone
->spanned_pages
= size
;
5141 zone
->present_pages
= real_size
;
5144 realtotalpages
+= real_size
;
5147 pgdat
->node_spanned_pages
= totalpages
;
5148 pgdat
->node_present_pages
= realtotalpages
;
5149 printk(KERN_DEBUG
"On node %d totalpages: %lu\n", pgdat
->node_id
,
5153 #ifndef CONFIG_SPARSEMEM
5155 * Calculate the size of the zone->blockflags rounded to an unsigned long
5156 * Start by making sure zonesize is a multiple of pageblock_order by rounding
5157 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
5158 * round what is now in bits to nearest long in bits, then return it in
5161 static unsigned long __init
usemap_size(unsigned long zone_start_pfn
, unsigned long zonesize
)
5163 unsigned long usemapsize
;
5165 zonesize
+= zone_start_pfn
& (pageblock_nr_pages
-1);
5166 usemapsize
= roundup(zonesize
, pageblock_nr_pages
);
5167 usemapsize
= usemapsize
>> pageblock_order
;
5168 usemapsize
*= NR_PAGEBLOCK_BITS
;
5169 usemapsize
= roundup(usemapsize
, 8 * sizeof(unsigned long));
5171 return usemapsize
/ 8;
5174 static void __init
setup_usemap(struct pglist_data
*pgdat
,
5176 unsigned long zone_start_pfn
,
5177 unsigned long zonesize
)
5179 unsigned long usemapsize
= usemap_size(zone_start_pfn
, zonesize
);
5180 zone
->pageblock_flags
= NULL
;
5182 zone
->pageblock_flags
=
5183 memblock_virt_alloc_node_nopanic(usemapsize
,
5187 static inline void setup_usemap(struct pglist_data
*pgdat
, struct zone
*zone
,
5188 unsigned long zone_start_pfn
, unsigned long zonesize
) {}
5189 #endif /* CONFIG_SPARSEMEM */
5191 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
5193 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
5194 void __paginginit
set_pageblock_order(void)
5198 /* Check that pageblock_nr_pages has not already been setup */
5199 if (pageblock_order
)
5202 if (HPAGE_SHIFT
> PAGE_SHIFT
)
5203 order
= HUGETLB_PAGE_ORDER
;
5205 order
= MAX_ORDER
- 1;
5208 * Assume the largest contiguous order of interest is a huge page.
5209 * This value may be variable depending on boot parameters on IA64 and
5212 pageblock_order
= order
;
5214 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5217 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
5218 * is unused as pageblock_order is set at compile-time. See
5219 * include/linux/pageblock-flags.h for the values of pageblock_order based on
5222 void __paginginit
set_pageblock_order(void)
5226 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
5228 static unsigned long __paginginit
calc_memmap_size(unsigned long spanned_pages
,
5229 unsigned long present_pages
)
5231 unsigned long pages
= spanned_pages
;
5234 * Provide a more accurate estimation if there are holes within
5235 * the zone and SPARSEMEM is in use. If there are holes within the
5236 * zone, each populated memory region may cost us one or two extra
5237 * memmap pages due to alignment because memmap pages for each
5238 * populated regions may not naturally algined on page boundary.
5239 * So the (present_pages >> 4) heuristic is a tradeoff for that.
5241 if (spanned_pages
> present_pages
+ (present_pages
>> 4) &&
5242 IS_ENABLED(CONFIG_SPARSEMEM
))
5243 pages
= present_pages
;
5245 return PAGE_ALIGN(pages
* sizeof(struct page
)) >> PAGE_SHIFT
;
5249 * Set up the zone data structures:
5250 * - mark all pages reserved
5251 * - mark all memory queues empty
5252 * - clear the memory bitmaps
5254 * NOTE: pgdat should get zeroed by caller.
5256 static void __paginginit
free_area_init_core(struct pglist_data
*pgdat
)
5259 int nid
= pgdat
->node_id
;
5260 unsigned long zone_start_pfn
= pgdat
->node_start_pfn
;
5263 pgdat_resize_init(pgdat
);
5264 #ifdef CONFIG_NUMA_BALANCING
5265 spin_lock_init(&pgdat
->numabalancing_migrate_lock
);
5266 pgdat
->numabalancing_migrate_nr_pages
= 0;
5267 pgdat
->numabalancing_migrate_next_window
= jiffies
;
5269 init_waitqueue_head(&pgdat
->kswapd_wait
);
5270 init_waitqueue_head(&pgdat
->pfmemalloc_wait
);
5271 pgdat_page_ext_init(pgdat
);
5273 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
5274 struct zone
*zone
= pgdat
->node_zones
+ j
;
5275 unsigned long size
, realsize
, freesize
, memmap_pages
;
5277 size
= zone
->spanned_pages
;
5278 realsize
= freesize
= zone
->present_pages
;
5281 * Adjust freesize so that it accounts for how much memory
5282 * is used by this zone for memmap. This affects the watermark
5283 * and per-cpu initialisations
5285 memmap_pages
= calc_memmap_size(size
, realsize
);
5286 if (!is_highmem_idx(j
)) {
5287 if (freesize
>= memmap_pages
) {
5288 freesize
-= memmap_pages
;
5291 " %s zone: %lu pages used for memmap\n",
5292 zone_names
[j
], memmap_pages
);
5295 " %s zone: %lu pages exceeds freesize %lu\n",
5296 zone_names
[j
], memmap_pages
, freesize
);
5299 /* Account for reserved pages */
5300 if (j
== 0 && freesize
> dma_reserve
) {
5301 freesize
-= dma_reserve
;
5302 printk(KERN_DEBUG
" %s zone: %lu pages reserved\n",
5303 zone_names
[0], dma_reserve
);
5306 if (!is_highmem_idx(j
))
5307 nr_kernel_pages
+= freesize
;
5308 /* Charge for highmem memmap if there are enough kernel pages */
5309 else if (nr_kernel_pages
> memmap_pages
* 2)
5310 nr_kernel_pages
-= memmap_pages
;
5311 nr_all_pages
+= freesize
;
5314 * Set an approximate value for lowmem here, it will be adjusted
5315 * when the bootmem allocator frees pages into the buddy system.
5316 * And all highmem pages will be managed by the buddy system.
5318 zone
->managed_pages
= is_highmem_idx(j
) ? realsize
: freesize
;
5321 zone
->min_unmapped_pages
= (freesize
*sysctl_min_unmapped_ratio
)
5323 zone
->min_slab_pages
= (freesize
* sysctl_min_slab_ratio
) / 100;
5325 zone
->name
= zone_names
[j
];
5326 spin_lock_init(&zone
->lock
);
5327 spin_lock_init(&zone
->lru_lock
);
5328 zone_seqlock_init(zone
);
5329 zone
->zone_pgdat
= pgdat
;
5330 zone_pcp_init(zone
);
5332 /* For bootup, initialized properly in watermark setup */
5333 mod_zone_page_state(zone
, NR_ALLOC_BATCH
, zone
->managed_pages
);
5335 lruvec_init(&zone
->lruvec
);
5339 set_pageblock_order();
5340 setup_usemap(pgdat
, zone
, zone_start_pfn
, size
);
5341 ret
= init_currently_empty_zone(zone
, zone_start_pfn
, size
);
5343 memmap_init(size
, nid
, j
, zone_start_pfn
);
5344 zone_start_pfn
+= size
;
5348 static void __init_refok
alloc_node_mem_map(struct pglist_data
*pgdat
)
5350 unsigned long __maybe_unused start
= 0;
5351 unsigned long __maybe_unused offset
= 0;
5353 /* Skip empty nodes */
5354 if (!pgdat
->node_spanned_pages
)
5357 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5358 start
= pgdat
->node_start_pfn
& ~(MAX_ORDER_NR_PAGES
- 1);
5359 offset
= pgdat
->node_start_pfn
- start
;
5360 /* ia64 gets its own node_mem_map, before this, without bootmem */
5361 if (!pgdat
->node_mem_map
) {
5362 unsigned long size
, end
;
5366 * The zone's endpoints aren't required to be MAX_ORDER
5367 * aligned but the node_mem_map endpoints must be in order
5368 * for the buddy allocator to function correctly.
5370 end
= pgdat_end_pfn(pgdat
);
5371 end
= ALIGN(end
, MAX_ORDER_NR_PAGES
);
5372 size
= (end
- start
) * sizeof(struct page
);
5373 map
= alloc_remap(pgdat
->node_id
, size
);
5375 map
= memblock_virt_alloc_node_nopanic(size
,
5377 pgdat
->node_mem_map
= map
+ offset
;
5379 #ifndef CONFIG_NEED_MULTIPLE_NODES
5381 * With no DISCONTIG, the global mem_map is just set as node 0's
5383 if (pgdat
== NODE_DATA(0)) {
5384 mem_map
= NODE_DATA(0)->node_mem_map
;
5385 #if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
5386 if (page_to_pfn(mem_map
) != pgdat
->node_start_pfn
)
5388 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5391 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
5394 void __paginginit
free_area_init_node(int nid
, unsigned long *zones_size
,
5395 unsigned long node_start_pfn
, unsigned long *zholes_size
)
5397 pg_data_t
*pgdat
= NODE_DATA(nid
);
5398 unsigned long start_pfn
= 0;
5399 unsigned long end_pfn
= 0;
5401 /* pg_data_t should be reset to zero when it's allocated */
5402 WARN_ON(pgdat
->nr_zones
|| pgdat
->classzone_idx
);
5404 pgdat
->node_id
= nid
;
5405 pgdat
->node_start_pfn
= node_start_pfn
;
5406 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5407 get_pfn_range_for_nid(nid
, &start_pfn
, &end_pfn
);
5408 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid
,
5409 (u64
)start_pfn
<< PAGE_SHIFT
,
5410 end_pfn
? ((u64
)end_pfn
<< PAGE_SHIFT
) - 1 : 0);
5412 calculate_node_totalpages(pgdat
, start_pfn
, end_pfn
,
5413 zones_size
, zholes_size
);
5415 alloc_node_mem_map(pgdat
);
5416 #ifdef CONFIG_FLAT_NODE_MEM_MAP
5417 printk(KERN_DEBUG
"free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
5418 nid
, (unsigned long)pgdat
,
5419 (unsigned long)pgdat
->node_mem_map
);
5422 reset_deferred_meminit(pgdat
);
5423 free_area_init_core(pgdat
);
5426 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
5428 #if MAX_NUMNODES > 1
5430 * Figure out the number of possible node ids.
5432 void __init
setup_nr_node_ids(void)
5434 unsigned int highest
;
5436 highest
= find_last_bit(node_possible_map
.bits
, MAX_NUMNODES
);
5437 nr_node_ids
= highest
+ 1;
5442 * node_map_pfn_alignment - determine the maximum internode alignment
5444 * This function should be called after node map is populated and sorted.
5445 * It calculates the maximum power of two alignment which can distinguish
5448 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
5449 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
5450 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
5451 * shifted, 1GiB is enough and this function will indicate so.
5453 * This is used to test whether pfn -> nid mapping of the chosen memory
5454 * model has fine enough granularity to avoid incorrect mapping for the
5455 * populated node map.
5457 * Returns the determined alignment in pfn's. 0 if there is no alignment
5458 * requirement (single node).
5460 unsigned long __init
node_map_pfn_alignment(void)
5462 unsigned long accl_mask
= 0, last_end
= 0;
5463 unsigned long start
, end
, mask
;
5467 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start
, &end
, &nid
) {
5468 if (!start
|| last_nid
< 0 || last_nid
== nid
) {
5475 * Start with a mask granular enough to pin-point to the
5476 * start pfn and tick off bits one-by-one until it becomes
5477 * too coarse to separate the current node from the last.
5479 mask
= ~((1 << __ffs(start
)) - 1);
5480 while (mask
&& last_end
<= (start
& (mask
<< 1)))
5483 /* accumulate all internode masks */
5487 /* convert mask to number of pages */
5488 return ~accl_mask
+ 1;
5491 /* Find the lowest pfn for a node */
5492 static unsigned long __init
find_min_pfn_for_node(int nid
)
5494 unsigned long min_pfn
= ULONG_MAX
;
5495 unsigned long start_pfn
;
5498 for_each_mem_pfn_range(i
, nid
, &start_pfn
, NULL
, NULL
)
5499 min_pfn
= min(min_pfn
, start_pfn
);
5501 if (min_pfn
== ULONG_MAX
) {
5503 "Could not find start_pfn for node %d\n", nid
);
5511 * find_min_pfn_with_active_regions - Find the minimum PFN registered
5513 * It returns the minimum PFN based on information provided via
5514 * memblock_set_node().
5516 unsigned long __init
find_min_pfn_with_active_regions(void)
5518 return find_min_pfn_for_node(MAX_NUMNODES
);
5522 * early_calculate_totalpages()
5523 * Sum pages in active regions for movable zone.
5524 * Populate N_MEMORY for calculating usable_nodes.
5526 static unsigned long __init
early_calculate_totalpages(void)
5528 unsigned long totalpages
= 0;
5529 unsigned long start_pfn
, end_pfn
;
5532 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
) {
5533 unsigned long pages
= end_pfn
- start_pfn
;
5535 totalpages
+= pages
;
5537 node_set_state(nid
, N_MEMORY
);
5543 * Find the PFN the Movable zone begins in each node. Kernel memory
5544 * is spread evenly between nodes as long as the nodes have enough
5545 * memory. When they don't, some nodes will have more kernelcore than
5548 static void __init
find_zone_movable_pfns_for_nodes(void)
5551 unsigned long usable_startpfn
;
5552 unsigned long kernelcore_node
, kernelcore_remaining
;
5553 /* save the state before borrow the nodemask */
5554 nodemask_t saved_node_state
= node_states
[N_MEMORY
];
5555 unsigned long totalpages
= early_calculate_totalpages();
5556 int usable_nodes
= nodes_weight(node_states
[N_MEMORY
]);
5557 struct memblock_region
*r
;
5559 /* Need to find movable_zone earlier when movable_node is specified. */
5560 find_usable_zone_for_movable();
5563 * If movable_node is specified, ignore kernelcore and movablecore
5566 if (movable_node_is_enabled()) {
5567 for_each_memblock(memory
, r
) {
5568 if (!memblock_is_hotpluggable(r
))
5573 usable_startpfn
= PFN_DOWN(r
->base
);
5574 zone_movable_pfn
[nid
] = zone_movable_pfn
[nid
] ?
5575 min(usable_startpfn
, zone_movable_pfn
[nid
]) :
5583 * If movablecore=nn[KMG] was specified, calculate what size of
5584 * kernelcore that corresponds so that memory usable for
5585 * any allocation type is evenly spread. If both kernelcore
5586 * and movablecore are specified, then the value of kernelcore
5587 * will be used for required_kernelcore if it's greater than
5588 * what movablecore would have allowed.
5590 if (required_movablecore
) {
5591 unsigned long corepages
;
5594 * Round-up so that ZONE_MOVABLE is at least as large as what
5595 * was requested by the user
5597 required_movablecore
=
5598 roundup(required_movablecore
, MAX_ORDER_NR_PAGES
);
5599 required_movablecore
= min(totalpages
, required_movablecore
);
5600 corepages
= totalpages
- required_movablecore
;
5602 required_kernelcore
= max(required_kernelcore
, corepages
);
5606 * If kernelcore was not specified or kernelcore size is larger
5607 * than totalpages, there is no ZONE_MOVABLE.
5609 if (!required_kernelcore
|| required_kernelcore
>= totalpages
)
5612 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
5613 usable_startpfn
= arch_zone_lowest_possible_pfn
[movable_zone
];
5616 /* Spread kernelcore memory as evenly as possible throughout nodes */
5617 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5618 for_each_node_state(nid
, N_MEMORY
) {
5619 unsigned long start_pfn
, end_pfn
;
5622 * Recalculate kernelcore_node if the division per node
5623 * now exceeds what is necessary to satisfy the requested
5624 * amount of memory for the kernel
5626 if (required_kernelcore
< kernelcore_node
)
5627 kernelcore_node
= required_kernelcore
/ usable_nodes
;
5630 * As the map is walked, we track how much memory is usable
5631 * by the kernel using kernelcore_remaining. When it is
5632 * 0, the rest of the node is usable by ZONE_MOVABLE
5634 kernelcore_remaining
= kernelcore_node
;
5636 /* Go through each range of PFNs within this node */
5637 for_each_mem_pfn_range(i
, nid
, &start_pfn
, &end_pfn
, NULL
) {
5638 unsigned long size_pages
;
5640 start_pfn
= max(start_pfn
, zone_movable_pfn
[nid
]);
5641 if (start_pfn
>= end_pfn
)
5644 /* Account for what is only usable for kernelcore */
5645 if (start_pfn
< usable_startpfn
) {
5646 unsigned long kernel_pages
;
5647 kernel_pages
= min(end_pfn
, usable_startpfn
)
5650 kernelcore_remaining
-= min(kernel_pages
,
5651 kernelcore_remaining
);
5652 required_kernelcore
-= min(kernel_pages
,
5653 required_kernelcore
);
5655 /* Continue if range is now fully accounted */
5656 if (end_pfn
<= usable_startpfn
) {
5659 * Push zone_movable_pfn to the end so
5660 * that if we have to rebalance
5661 * kernelcore across nodes, we will
5662 * not double account here
5664 zone_movable_pfn
[nid
] = end_pfn
;
5667 start_pfn
= usable_startpfn
;
5671 * The usable PFN range for ZONE_MOVABLE is from
5672 * start_pfn->end_pfn. Calculate size_pages as the
5673 * number of pages used as kernelcore
5675 size_pages
= end_pfn
- start_pfn
;
5676 if (size_pages
> kernelcore_remaining
)
5677 size_pages
= kernelcore_remaining
;
5678 zone_movable_pfn
[nid
] = start_pfn
+ size_pages
;
5681 * Some kernelcore has been met, update counts and
5682 * break if the kernelcore for this node has been
5685 required_kernelcore
-= min(required_kernelcore
,
5687 kernelcore_remaining
-= size_pages
;
5688 if (!kernelcore_remaining
)
5694 * If there is still required_kernelcore, we do another pass with one
5695 * less node in the count. This will push zone_movable_pfn[nid] further
5696 * along on the nodes that still have memory until kernelcore is
5700 if (usable_nodes
&& required_kernelcore
> usable_nodes
)
5704 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
5705 for (nid
= 0; nid
< MAX_NUMNODES
; nid
++)
5706 zone_movable_pfn
[nid
] =
5707 roundup(zone_movable_pfn
[nid
], MAX_ORDER_NR_PAGES
);
5710 /* restore the node_state */
5711 node_states
[N_MEMORY
] = saved_node_state
;
5714 /* Any regular or high memory on that node ? */
5715 static void check_for_memory(pg_data_t
*pgdat
, int nid
)
5717 enum zone_type zone_type
;
5719 if (N_MEMORY
== N_NORMAL_MEMORY
)
5722 for (zone_type
= 0; zone_type
<= ZONE_MOVABLE
- 1; zone_type
++) {
5723 struct zone
*zone
= &pgdat
->node_zones
[zone_type
];
5724 if (populated_zone(zone
)) {
5725 node_set_state(nid
, N_HIGH_MEMORY
);
5726 if (N_NORMAL_MEMORY
!= N_HIGH_MEMORY
&&
5727 zone_type
<= ZONE_NORMAL
)
5728 node_set_state(nid
, N_NORMAL_MEMORY
);
5735 * free_area_init_nodes - Initialise all pg_data_t and zone data
5736 * @max_zone_pfn: an array of max PFNs for each zone
5738 * This will call free_area_init_node() for each active node in the system.
5739 * Using the page ranges provided by memblock_set_node(), the size of each
5740 * zone in each node and their holes is calculated. If the maximum PFN
5741 * between two adjacent zones match, it is assumed that the zone is empty.
5742 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
5743 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
5744 * starts where the previous one ended. For example, ZONE_DMA32 starts
5745 * at arch_max_dma_pfn.
5747 void __init
free_area_init_nodes(unsigned long *max_zone_pfn
)
5749 unsigned long start_pfn
, end_pfn
;
5752 /* Record where the zone boundaries are */
5753 memset(arch_zone_lowest_possible_pfn
, 0,
5754 sizeof(arch_zone_lowest_possible_pfn
));
5755 memset(arch_zone_highest_possible_pfn
, 0,
5756 sizeof(arch_zone_highest_possible_pfn
));
5758 start_pfn
= find_min_pfn_with_active_regions();
5760 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5761 if (i
== ZONE_MOVABLE
)
5764 end_pfn
= max(max_zone_pfn
[i
], start_pfn
);
5765 arch_zone_lowest_possible_pfn
[i
] = start_pfn
;
5766 arch_zone_highest_possible_pfn
[i
] = end_pfn
;
5768 start_pfn
= end_pfn
;
5770 arch_zone_lowest_possible_pfn
[ZONE_MOVABLE
] = 0;
5771 arch_zone_highest_possible_pfn
[ZONE_MOVABLE
] = 0;
5773 /* Find the PFNs that ZONE_MOVABLE begins at in each node */
5774 memset(zone_movable_pfn
, 0, sizeof(zone_movable_pfn
));
5775 find_zone_movable_pfns_for_nodes();
5777 /* Print out the zone ranges */
5778 pr_info("Zone ranges:\n");
5779 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
5780 if (i
== ZONE_MOVABLE
)
5782 pr_info(" %-8s ", zone_names
[i
]);
5783 if (arch_zone_lowest_possible_pfn
[i
] ==
5784 arch_zone_highest_possible_pfn
[i
])
5787 pr_cont("[mem %#018Lx-%#018Lx]\n",
5788 (u64
)arch_zone_lowest_possible_pfn
[i
]
5790 ((u64
)arch_zone_highest_possible_pfn
[i
]
5791 << PAGE_SHIFT
) - 1);
5794 /* Print out the PFNs ZONE_MOVABLE begins at in each node */
5795 pr_info("Movable zone start for each node\n");
5796 for (i
= 0; i
< MAX_NUMNODES
; i
++) {
5797 if (zone_movable_pfn
[i
])
5798 pr_info(" Node %d: %#018Lx\n", i
,
5799 (u64
)zone_movable_pfn
[i
] << PAGE_SHIFT
);
5802 /* Print out the early node map */
5803 pr_info("Early memory node ranges\n");
5804 for_each_mem_pfn_range(i
, MAX_NUMNODES
, &start_pfn
, &end_pfn
, &nid
)
5805 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid
,
5806 (u64
)start_pfn
<< PAGE_SHIFT
,
5807 ((u64
)end_pfn
<< PAGE_SHIFT
) - 1);
5809 /* Initialise every node */
5810 mminit_verify_pageflags_layout();
5811 setup_nr_node_ids();
5812 for_each_online_node(nid
) {
5813 pg_data_t
*pgdat
= NODE_DATA(nid
);
5814 free_area_init_node(nid
, NULL
,
5815 find_min_pfn_for_node(nid
), NULL
);
5817 /* Any memory on that node */
5818 if (pgdat
->node_present_pages
)
5819 node_set_state(nid
, N_MEMORY
);
5820 check_for_memory(pgdat
, nid
);
5824 static int __init
cmdline_parse_core(char *p
, unsigned long *core
)
5826 unsigned long long coremem
;
5830 coremem
= memparse(p
, &p
);
5831 *core
= coremem
>> PAGE_SHIFT
;
5833 /* Paranoid check that UL is enough for the coremem value */
5834 WARN_ON((coremem
>> PAGE_SHIFT
) > ULONG_MAX
);
5840 * kernelcore=size sets the amount of memory for use for allocations that
5841 * cannot be reclaimed or migrated.
5843 static int __init
cmdline_parse_kernelcore(char *p
)
5845 return cmdline_parse_core(p
, &required_kernelcore
);
5849 * movablecore=size sets the amount of memory for use for allocations that
5850 * can be reclaimed or migrated.
5852 static int __init
cmdline_parse_movablecore(char *p
)
5854 return cmdline_parse_core(p
, &required_movablecore
);
5857 early_param("kernelcore", cmdline_parse_kernelcore
);
5858 early_param("movablecore", cmdline_parse_movablecore
);
5860 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5862 void adjust_managed_page_count(struct page
*page
, long count
)
5864 spin_lock(&managed_page_count_lock
);
5865 page_zone(page
)->managed_pages
+= count
;
5866 totalram_pages
+= count
;
5867 #ifdef CONFIG_HIGHMEM
5868 if (PageHighMem(page
))
5869 totalhigh_pages
+= count
;
5871 spin_unlock(&managed_page_count_lock
);
5873 EXPORT_SYMBOL(adjust_managed_page_count
);
5875 unsigned long free_reserved_area(void *start
, void *end
, int poison
, char *s
)
5878 unsigned long pages
= 0;
5880 start
= (void *)PAGE_ALIGN((unsigned long)start
);
5881 end
= (void *)((unsigned long)end
& PAGE_MASK
);
5882 for (pos
= start
; pos
< end
; pos
+= PAGE_SIZE
, pages
++) {
5883 if ((unsigned int)poison
<= 0xFF)
5884 memset(pos
, poison
, PAGE_SIZE
);
5885 free_reserved_page(virt_to_page(pos
));
5889 pr_info("Freeing %s memory: %ldK\n",
5890 s
, pages
<< (PAGE_SHIFT
- 10));
5894 EXPORT_SYMBOL(free_reserved_area
);
5896 #ifdef CONFIG_HIGHMEM
5897 void free_highmem_page(struct page
*page
)
5899 __free_reserved_page(page
);
5901 page_zone(page
)->managed_pages
++;
5907 void __init
mem_init_print_info(const char *str
)
5909 unsigned long physpages
, codesize
, datasize
, rosize
, bss_size
;
5910 unsigned long init_code_size
, init_data_size
;
5912 physpages
= get_num_physpages();
5913 codesize
= _etext
- _stext
;
5914 datasize
= _edata
- _sdata
;
5915 rosize
= __end_rodata
- __start_rodata
;
5916 bss_size
= __bss_stop
- __bss_start
;
5917 init_data_size
= __init_end
- __init_begin
;
5918 init_code_size
= _einittext
- _sinittext
;
5921 * Detect special cases and adjust section sizes accordingly:
5922 * 1) .init.* may be embedded into .data sections
5923 * 2) .init.text.* may be out of [__init_begin, __init_end],
5924 * please refer to arch/tile/kernel/vmlinux.lds.S.
5925 * 3) .rodata.* may be embedded into .text or .data sections.
5927 #define adj_init_size(start, end, size, pos, adj) \
5929 if (start <= pos && pos < end && size > adj) \
5933 adj_init_size(__init_begin
, __init_end
, init_data_size
,
5934 _sinittext
, init_code_size
);
5935 adj_init_size(_stext
, _etext
, codesize
, _sinittext
, init_code_size
);
5936 adj_init_size(_sdata
, _edata
, datasize
, __init_begin
, init_data_size
);
5937 adj_init_size(_stext
, _etext
, codesize
, __start_rodata
, rosize
);
5938 adj_init_size(_sdata
, _edata
, datasize
, __start_rodata
, rosize
);
5940 #undef adj_init_size
5942 pr_info("Memory: %luK/%luK available "
5943 "(%luK kernel code, %luK rwdata, %luK rodata, "
5944 "%luK init, %luK bss, %luK reserved, %luK cma-reserved"
5945 #ifdef CONFIG_HIGHMEM
5949 nr_free_pages() << (PAGE_SHIFT
-10), physpages
<< (PAGE_SHIFT
-10),
5950 codesize
>> 10, datasize
>> 10, rosize
>> 10,
5951 (init_data_size
+ init_code_size
) >> 10, bss_size
>> 10,
5952 (physpages
- totalram_pages
- totalcma_pages
) << (PAGE_SHIFT
-10),
5953 totalcma_pages
<< (PAGE_SHIFT
-10),
5954 #ifdef CONFIG_HIGHMEM
5955 totalhigh_pages
<< (PAGE_SHIFT
-10),
5957 str
? ", " : "", str
? str
: "");
5961 * set_dma_reserve - set the specified number of pages reserved in the first zone
5962 * @new_dma_reserve: The number of pages to mark reserved
5964 * The per-cpu batchsize and zone watermarks are determined by managed_pages.
5965 * In the DMA zone, a significant percentage may be consumed by kernel image
5966 * and other unfreeable allocations which can skew the watermarks badly. This
5967 * function may optionally be used to account for unfreeable pages in the
5968 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
5969 * smaller per-cpu batchsize.
5971 void __init
set_dma_reserve(unsigned long new_dma_reserve
)
5973 dma_reserve
= new_dma_reserve
;
5976 void __init
free_area_init(unsigned long *zones_size
)
5978 free_area_init_node(0, zones_size
,
5979 __pa(PAGE_OFFSET
) >> PAGE_SHIFT
, NULL
);
5982 static int page_alloc_cpu_notify(struct notifier_block
*self
,
5983 unsigned long action
, void *hcpu
)
5985 int cpu
= (unsigned long)hcpu
;
5987 if (action
== CPU_DEAD
|| action
== CPU_DEAD_FROZEN
) {
5988 lru_add_drain_cpu(cpu
);
5992 * Spill the event counters of the dead processor
5993 * into the current processors event counters.
5994 * This artificially elevates the count of the current
5997 vm_events_fold_cpu(cpu
);
6000 * Zero the differential counters of the dead processor
6001 * so that the vm statistics are consistent.
6003 * This is only okay since the processor is dead and cannot
6004 * race with what we are doing.
6006 cpu_vm_stats_fold(cpu
);
6011 void __init
page_alloc_init(void)
6013 hotcpu_notifier(page_alloc_cpu_notify
, 0);
6017 * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
6018 * or min_free_kbytes changes.
6020 static void calculate_totalreserve_pages(void)
6022 struct pglist_data
*pgdat
;
6023 unsigned long reserve_pages
= 0;
6024 enum zone_type i
, j
;
6026 for_each_online_pgdat(pgdat
) {
6027 for (i
= 0; i
< MAX_NR_ZONES
; i
++) {
6028 struct zone
*zone
= pgdat
->node_zones
+ i
;
6031 /* Find valid and maximum lowmem_reserve in the zone */
6032 for (j
= i
; j
< MAX_NR_ZONES
; j
++) {
6033 if (zone
->lowmem_reserve
[j
] > max
)
6034 max
= zone
->lowmem_reserve
[j
];
6037 /* we treat the high watermark as reserved pages. */
6038 max
+= high_wmark_pages(zone
);
6040 if (max
> zone
->managed_pages
)
6041 max
= zone
->managed_pages
;
6042 reserve_pages
+= max
;
6044 * Lowmem reserves are not available to
6045 * GFP_HIGHUSER page cache allocations and
6046 * kswapd tries to balance zones to their high
6047 * watermark. As a result, neither should be
6048 * regarded as dirtyable memory, to prevent a
6049 * situation where reclaim has to clean pages
6050 * in order to balance the zones.
6052 zone
->dirty_balance_reserve
= max
;
6055 dirty_balance_reserve
= reserve_pages
;
6056 totalreserve_pages
= reserve_pages
;
6060 * setup_per_zone_lowmem_reserve - called whenever
6061 * sysctl_lowmem_reserve_ratio changes. Ensures that each zone
6062 * has a correct pages reserved value, so an adequate number of
6063 * pages are left in the zone after a successful __alloc_pages().
6065 static void setup_per_zone_lowmem_reserve(void)
6067 struct pglist_data
*pgdat
;
6068 enum zone_type j
, idx
;
6070 for_each_online_pgdat(pgdat
) {
6071 for (j
= 0; j
< MAX_NR_ZONES
; j
++) {
6072 struct zone
*zone
= pgdat
->node_zones
+ j
;
6073 unsigned long managed_pages
= zone
->managed_pages
;
6075 zone
->lowmem_reserve
[j
] = 0;
6079 struct zone
*lower_zone
;
6083 if (sysctl_lowmem_reserve_ratio
[idx
] < 1)
6084 sysctl_lowmem_reserve_ratio
[idx
] = 1;
6086 lower_zone
= pgdat
->node_zones
+ idx
;
6087 lower_zone
->lowmem_reserve
[j
] = managed_pages
/
6088 sysctl_lowmem_reserve_ratio
[idx
];
6089 managed_pages
+= lower_zone
->managed_pages
;
6094 /* update totalreserve_pages */
6095 calculate_totalreserve_pages();
6098 static void __setup_per_zone_wmarks(void)
6100 unsigned long pages_min
= min_free_kbytes
>> (PAGE_SHIFT
- 10);
6101 unsigned long pages_low
= extra_free_kbytes
>> (PAGE_SHIFT
- 10);
6102 unsigned long lowmem_pages
= 0;
6104 unsigned long flags
;
6106 /* Calculate total number of !ZONE_HIGHMEM pages */
6107 for_each_zone(zone
) {
6108 if (!is_highmem(zone
))
6109 lowmem_pages
+= zone
->managed_pages
;
6112 for_each_zone(zone
) {
6115 spin_lock_irqsave(&zone
->lock
, flags
);
6116 min
= (u64
)pages_min
* zone
->managed_pages
;
6117 do_div(min
, lowmem_pages
);
6118 low
= (u64
)pages_low
* zone
->managed_pages
;
6119 do_div(low
, vm_total_pages
);
6121 if (is_highmem(zone
)) {
6123 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
6124 * need highmem pages, so cap pages_min to a small
6127 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
6128 * deltas control asynch page reclaim, and so should
6129 * not be capped for highmem.
6131 unsigned long min_pages
;
6133 min_pages
= zone
->managed_pages
/ 1024;
6134 min_pages
= clamp(min_pages
, SWAP_CLUSTER_MAX
, 128UL);
6135 zone
->watermark
[WMARK_MIN
] = min_pages
;
6138 * If it's a lowmem zone, reserve a number of pages
6139 * proportionate to the zone's size.
6141 zone
->watermark
[WMARK_MIN
] = min
;
6144 zone
->watermark
[WMARK_LOW
] = min_wmark_pages(zone
) +
6146 zone
->watermark
[WMARK_HIGH
] = min_wmark_pages(zone
) +
6149 __mod_zone_page_state(zone
, NR_ALLOC_BATCH
,
6150 high_wmark_pages(zone
) - low_wmark_pages(zone
) -
6151 atomic_long_read(&zone
->vm_stat
[NR_ALLOC_BATCH
]));
6153 spin_unlock_irqrestore(&zone
->lock
, flags
);
6156 /* update totalreserve_pages */
6157 calculate_totalreserve_pages();
6161 * setup_per_zone_wmarks - called when min_free_kbytes changes
6162 * or when memory is hot-{added|removed}
6164 * Ensures that the watermark[min,low,high] values for each zone are set
6165 * correctly with respect to min_free_kbytes.
6167 void setup_per_zone_wmarks(void)
6169 mutex_lock(&zonelists_mutex
);
6170 __setup_per_zone_wmarks();
6171 mutex_unlock(&zonelists_mutex
);
6175 * The inactive anon list should be small enough that the VM never has to
6176 * do too much work, but large enough that each inactive page has a chance
6177 * to be referenced again before it is swapped out.
6179 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
6180 * INACTIVE_ANON pages on this zone's LRU, maintained by the
6181 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
6182 * the anonymous pages are kept on the inactive list.
6185 * memory ratio inactive anon
6186 * -------------------------------------
6195 static void __meminit
calculate_zone_inactive_ratio(struct zone
*zone
)
6197 unsigned int gb
, ratio
;
6199 /* Zone size in gigabytes */
6200 gb
= zone
->managed_pages
>> (30 - PAGE_SHIFT
);
6202 ratio
= int_sqrt(10 * gb
);
6206 zone
->inactive_ratio
= ratio
;
6209 static void __meminit
setup_per_zone_inactive_ratio(void)
6214 calculate_zone_inactive_ratio(zone
);
6218 * Initialise min_free_kbytes.
6220 * For small machines we want it small (128k min). For large machines
6221 * we want it large (64MB max). But it is not linear, because network
6222 * bandwidth does not increase linearly with machine size. We use
6224 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
6225 * min_free_kbytes = sqrt(lowmem_kbytes * 16)
6241 int __meminit
init_per_zone_wmark_min(void)
6243 unsigned long lowmem_kbytes
;
6244 int new_min_free_kbytes
;
6246 lowmem_kbytes
= nr_free_buffer_pages() * (PAGE_SIZE
>> 10);
6247 new_min_free_kbytes
= int_sqrt(lowmem_kbytes
* 16);
6249 if (new_min_free_kbytes
> user_min_free_kbytes
) {
6250 min_free_kbytes
= new_min_free_kbytes
;
6251 if (min_free_kbytes
< 128)
6252 min_free_kbytes
= 128;
6253 if (min_free_kbytes
> 65536)
6254 min_free_kbytes
= 65536;
6256 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
6257 new_min_free_kbytes
, user_min_free_kbytes
);
6259 setup_per_zone_wmarks();
6260 refresh_zone_stat_thresholds();
6261 setup_per_zone_lowmem_reserve();
6262 setup_per_zone_inactive_ratio();
6265 core_initcall(init_per_zone_wmark_min
)
6268 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
6269 * that we can call two helper functions whenever min_free_kbytes
6270 * or extra_free_kbytes changes.
6272 int min_free_kbytes_sysctl_handler(struct ctl_table
*table
, int write
,
6273 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6277 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6282 user_min_free_kbytes
= min_free_kbytes
;
6283 setup_per_zone_wmarks();
6289 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6290 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6295 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6300 zone
->min_unmapped_pages
= (zone
->managed_pages
*
6301 sysctl_min_unmapped_ratio
) / 100;
6305 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6306 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6311 rc
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6316 zone
->min_slab_pages
= (zone
->managed_pages
*
6317 sysctl_min_slab_ratio
) / 100;
6323 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
6324 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
6325 * whenever sysctl_lowmem_reserve_ratio changes.
6327 * The reserve ratio obviously has absolutely no relation with the
6328 * minimum watermarks. The lowmem reserve ratio can only make sense
6329 * if in function of the boot time zone sizes.
6331 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*table
, int write
,
6332 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6334 proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6335 setup_per_zone_lowmem_reserve();
6340 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
6341 * cpu. It is the fraction of total pages in each zone that a hot per cpu
6342 * pagelist can have before it gets flushed back to buddy allocator.
6344 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*table
, int write
,
6345 void __user
*buffer
, size_t *length
, loff_t
*ppos
)
6348 int old_percpu_pagelist_fraction
;
6351 mutex_lock(&pcp_batch_high_lock
);
6352 old_percpu_pagelist_fraction
= percpu_pagelist_fraction
;
6354 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
6355 if (!write
|| ret
< 0)
6358 /* Sanity checking to avoid pcp imbalance */
6359 if (percpu_pagelist_fraction
&&
6360 percpu_pagelist_fraction
< MIN_PERCPU_PAGELIST_FRACTION
) {
6361 percpu_pagelist_fraction
= old_percpu_pagelist_fraction
;
6367 if (percpu_pagelist_fraction
== old_percpu_pagelist_fraction
)
6370 for_each_populated_zone(zone
) {
6373 for_each_possible_cpu(cpu
)
6374 pageset_set_high_and_batch(zone
,
6375 per_cpu_ptr(zone
->pageset
, cpu
));
6378 mutex_unlock(&pcp_batch_high_lock
);
6383 int hashdist
= HASHDIST_DEFAULT
;
6385 static int __init
set_hashdist(char *str
)
6389 hashdist
= simple_strtoul(str
, &str
, 0);
6392 __setup("hashdist=", set_hashdist
);
6396 * allocate a large system hash table from bootmem
6397 * - it is assumed that the hash table must contain an exact power-of-2
6398 * quantity of entries
6399 * - limit is the number of hash buckets, not the total allocation size
6401 void *__init
alloc_large_system_hash(const char *tablename
,
6402 unsigned long bucketsize
,
6403 unsigned long numentries
,
6406 unsigned int *_hash_shift
,
6407 unsigned int *_hash_mask
,
6408 unsigned long low_limit
,
6409 unsigned long high_limit
)
6411 unsigned long long max
= high_limit
;
6412 unsigned long log2qty
, size
;
6415 /* allow the kernel cmdline to have a say */
6417 /* round applicable memory size up to nearest megabyte */
6418 numentries
= nr_kernel_pages
;
6420 /* It isn't necessary when PAGE_SIZE >= 1MB */
6421 if (PAGE_SHIFT
< 20)
6422 numentries
= round_up(numentries
, (1<<20)/PAGE_SIZE
);
6424 /* limit to 1 bucket per 2^scale bytes of low memory */
6425 if (scale
> PAGE_SHIFT
)
6426 numentries
>>= (scale
- PAGE_SHIFT
);
6428 numentries
<<= (PAGE_SHIFT
- scale
);
6430 /* Make sure we've got at least a 0-order allocation.. */
6431 if (unlikely(flags
& HASH_SMALL
)) {
6432 /* Makes no sense without HASH_EARLY */
6433 WARN_ON(!(flags
& HASH_EARLY
));
6434 if (!(numentries
>> *_hash_shift
)) {
6435 numentries
= 1UL << *_hash_shift
;
6436 BUG_ON(!numentries
);
6438 } else if (unlikely((numentries
* bucketsize
) < PAGE_SIZE
))
6439 numentries
= PAGE_SIZE
/ bucketsize
;
6441 numentries
= roundup_pow_of_two(numentries
);
6443 /* limit allocation size to 1/16 total memory by default */
6445 max
= ((unsigned long long)nr_all_pages
<< PAGE_SHIFT
) >> 4;
6446 do_div(max
, bucketsize
);
6448 max
= min(max
, 0x80000000ULL
);
6450 if (numentries
< low_limit
)
6451 numentries
= low_limit
;
6452 if (numentries
> max
)
6455 log2qty
= ilog2(numentries
);
6458 size
= bucketsize
<< log2qty
;
6459 if (flags
& HASH_EARLY
)
6460 table
= memblock_virt_alloc_nopanic(size
, 0);
6462 table
= __vmalloc(size
, GFP_ATOMIC
, PAGE_KERNEL
);
6465 * If bucketsize is not a power-of-two, we may free
6466 * some pages at the end of hash table which
6467 * alloc_pages_exact() automatically does
6469 if (get_order(size
) < MAX_ORDER
) {
6470 table
= alloc_pages_exact(size
, GFP_ATOMIC
);
6471 kmemleak_alloc(table
, size
, 1, GFP_ATOMIC
);
6474 } while (!table
&& size
> PAGE_SIZE
&& --log2qty
);
6477 panic("Failed to allocate %s hash table\n", tablename
);
6479 printk(KERN_INFO
"%s hash table entries: %ld (order: %d, %lu bytes)\n",
6482 ilog2(size
) - PAGE_SHIFT
,
6486 *_hash_shift
= log2qty
;
6488 *_hash_mask
= (1 << log2qty
) - 1;
6493 /* Return a pointer to the bitmap storing bits affecting a block of pages */
6494 static inline unsigned long *get_pageblock_bitmap(struct zone
*zone
,
6497 #ifdef CONFIG_SPARSEMEM
6498 return __pfn_to_section(pfn
)->pageblock_flags
;
6500 return zone
->pageblock_flags
;
6501 #endif /* CONFIG_SPARSEMEM */
6504 static inline int pfn_to_bitidx(struct zone
*zone
, unsigned long pfn
)
6506 #ifdef CONFIG_SPARSEMEM
6507 pfn
&= (PAGES_PER_SECTION
-1);
6508 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6510 pfn
= pfn
- round_down(zone
->zone_start_pfn
, pageblock_nr_pages
);
6511 return (pfn
>> pageblock_order
) * NR_PAGEBLOCK_BITS
;
6512 #endif /* CONFIG_SPARSEMEM */
6516 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
6517 * @page: The page within the block of interest
6518 * @pfn: The target page frame number
6519 * @end_bitidx: The last bit of interest to retrieve
6520 * @mask: mask of bits that the caller is interested in
6522 * Return: pageblock_bits flags
6524 unsigned long get_pfnblock_flags_mask(struct page
*page
, unsigned long pfn
,
6525 unsigned long end_bitidx
,
6529 unsigned long *bitmap
;
6530 unsigned long bitidx
, word_bitidx
;
6533 zone
= page_zone(page
);
6534 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6535 bitidx
= pfn_to_bitidx(zone
, pfn
);
6536 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6537 bitidx
&= (BITS_PER_LONG
-1);
6539 word
= bitmap
[word_bitidx
];
6540 bitidx
+= end_bitidx
;
6541 return (word
>> (BITS_PER_LONG
- bitidx
- 1)) & mask
;
6545 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
6546 * @page: The page within the block of interest
6547 * @flags: The flags to set
6548 * @pfn: The target page frame number
6549 * @end_bitidx: The last bit of interest
6550 * @mask: mask of bits that the caller is interested in
6552 void set_pfnblock_flags_mask(struct page
*page
, unsigned long flags
,
6554 unsigned long end_bitidx
,
6558 unsigned long *bitmap
;
6559 unsigned long bitidx
, word_bitidx
;
6560 unsigned long old_word
, word
;
6562 BUILD_BUG_ON(NR_PAGEBLOCK_BITS
!= 4);
6564 zone
= page_zone(page
);
6565 bitmap
= get_pageblock_bitmap(zone
, pfn
);
6566 bitidx
= pfn_to_bitidx(zone
, pfn
);
6567 word_bitidx
= bitidx
/ BITS_PER_LONG
;
6568 bitidx
&= (BITS_PER_LONG
-1);
6570 VM_BUG_ON_PAGE(!zone_spans_pfn(zone
, pfn
), page
);
6572 bitidx
+= end_bitidx
;
6573 mask
<<= (BITS_PER_LONG
- bitidx
- 1);
6574 flags
<<= (BITS_PER_LONG
- bitidx
- 1);
6576 word
= READ_ONCE(bitmap
[word_bitidx
]);
6578 old_word
= cmpxchg(&bitmap
[word_bitidx
], word
, (word
& ~mask
) | flags
);
6579 if (word
== old_word
)
6586 * This function checks whether pageblock includes unmovable pages or not.
6587 * If @count is not zero, it is okay to include less @count unmovable pages
6589 * PageLRU check without isolation or lru_lock could race so that
6590 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
6591 * expect this function should be exact.
6593 bool has_unmovable_pages(struct zone
*zone
, struct page
*page
, int count
,
6594 bool skip_hwpoisoned_pages
)
6596 unsigned long pfn
, iter
, found
;
6600 * For avoiding noise data, lru_add_drain_all() should be called
6601 * If ZONE_MOVABLE, the zone never contains unmovable pages
6603 if (zone_idx(zone
) == ZONE_MOVABLE
)
6605 mt
= get_pageblock_migratetype(page
);
6606 if (mt
== MIGRATE_MOVABLE
|| is_migrate_cma(mt
))
6609 pfn
= page_to_pfn(page
);
6610 for (found
= 0, iter
= 0; iter
< pageblock_nr_pages
; iter
++) {
6611 unsigned long check
= pfn
+ iter
;
6613 if (!pfn_valid_within(check
))
6616 page
= pfn_to_page(check
);
6619 * Hugepages are not in LRU lists, but they're movable.
6620 * We need not scan over tail pages bacause we don't
6621 * handle each tail page individually in migration.
6623 if (PageHuge(page
)) {
6624 iter
= round_up(iter
+ 1, 1<<compound_order(page
)) - 1;
6629 * We can't use page_count without pin a page
6630 * because another CPU can free compound page.
6631 * This check already skips compound tails of THP
6632 * because their page->_count is zero at all time.
6634 if (!atomic_read(&page
->_count
)) {
6635 if (PageBuddy(page
))
6636 iter
+= (1 << page_order(page
)) - 1;
6641 * The HWPoisoned page may be not in buddy system, and
6642 * page_count() is not 0.
6644 if (skip_hwpoisoned_pages
&& PageHWPoison(page
))
6650 * If there are RECLAIMABLE pages, we need to check
6651 * it. But now, memory offline itself doesn't call
6652 * shrink_node_slabs() and it still to be fixed.
6655 * If the page is not RAM, page_count()should be 0.
6656 * we don't need more check. This is an _used_ not-movable page.
6658 * The problematic thing here is PG_reserved pages. PG_reserved
6659 * is set to both of a memory hole page and a _used_ kernel
6668 bool is_pageblock_removable_nolock(struct page
*page
)
6674 * We have to be careful here because we are iterating over memory
6675 * sections which are not zone aware so we might end up outside of
6676 * the zone but still within the section.
6677 * We have to take care about the node as well. If the node is offline
6678 * its NODE_DATA will be NULL - see page_zone.
6680 if (!node_online(page_to_nid(page
)))
6683 zone
= page_zone(page
);
6684 pfn
= page_to_pfn(page
);
6685 if (!zone_spans_pfn(zone
, pfn
))
6688 return !has_unmovable_pages(zone
, page
, 0, true);
6693 static unsigned long pfn_max_align_down(unsigned long pfn
)
6695 return pfn
& ~(max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6696 pageblock_nr_pages
) - 1);
6699 static unsigned long pfn_max_align_up(unsigned long pfn
)
6701 return ALIGN(pfn
, max_t(unsigned long, MAX_ORDER_NR_PAGES
,
6702 pageblock_nr_pages
));
6705 /* [start, end) must belong to a single zone. */
6706 static int __alloc_contig_migrate_range(struct compact_control
*cc
,
6707 unsigned long start
, unsigned long end
)
6709 /* This function is based on compact_zone() from compaction.c. */
6710 unsigned long nr_reclaimed
;
6711 unsigned long pfn
= start
;
6712 unsigned int tries
= 0;
6717 while (pfn
< end
|| !list_empty(&cc
->migratepages
)) {
6718 if (fatal_signal_pending(current
)) {
6723 if (list_empty(&cc
->migratepages
)) {
6724 cc
->nr_migratepages
= 0;
6725 pfn
= isolate_migratepages_range(cc
, pfn
, end
);
6731 } else if (++tries
== 5) {
6732 ret
= ret
< 0 ? ret
: -EBUSY
;
6736 nr_reclaimed
= reclaim_clean_pages_from_list(cc
->zone
,
6738 cc
->nr_migratepages
-= nr_reclaimed
;
6740 ret
= migrate_pages(&cc
->migratepages
, alloc_migrate_target
,
6741 NULL
, 0, cc
->mode
, MR_CMA
);
6744 putback_movable_pages(&cc
->migratepages
);
6751 * alloc_contig_range() -- tries to allocate given range of pages
6752 * @start: start PFN to allocate
6753 * @end: one-past-the-last PFN to allocate
6754 * @migratetype: migratetype of the underlaying pageblocks (either
6755 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks
6756 * in range must have the same migratetype and it must
6757 * be either of the two.
6759 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
6760 * aligned, however it's the caller's responsibility to guarantee that
6761 * we are the only thread that changes migrate type of pageblocks the
6764 * The PFN range must belong to a single zone.
6766 * Returns zero on success or negative error code. On success all
6767 * pages which PFN is in [start, end) are allocated for the caller and
6768 * need to be freed with free_contig_range().
6770 int alloc_contig_range(unsigned long start
, unsigned long end
,
6771 unsigned migratetype
)
6773 unsigned long outer_start
, outer_end
;
6777 struct compact_control cc
= {
6778 .nr_migratepages
= 0,
6780 .zone
= page_zone(pfn_to_page(start
)),
6781 .mode
= MIGRATE_SYNC
,
6782 .ignore_skip_hint
= true,
6784 INIT_LIST_HEAD(&cc
.migratepages
);
6787 * What we do here is we mark all pageblocks in range as
6788 * MIGRATE_ISOLATE. Because pageblock and max order pages may
6789 * have different sizes, and due to the way page allocator
6790 * work, we align the range to biggest of the two pages so
6791 * that page allocator won't try to merge buddies from
6792 * different pageblocks and change MIGRATE_ISOLATE to some
6793 * other migration type.
6795 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
6796 * migrate the pages from an unaligned range (ie. pages that
6797 * we are interested in). This will put all the pages in
6798 * range back to page allocator as MIGRATE_ISOLATE.
6800 * When this is done, we take the pages in range from page
6801 * allocator removing them from the buddy system. This way
6802 * page allocator will never consider using them.
6804 * This lets us mark the pageblocks back as
6805 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
6806 * aligned range but not in the unaligned, original range are
6807 * put back to page allocator so that buddy can use them.
6810 ret
= start_isolate_page_range(pfn_max_align_down(start
),
6811 pfn_max_align_up(end
), migratetype
,
6816 ret
= __alloc_contig_migrate_range(&cc
, start
, end
);
6821 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
6822 * aligned blocks that are marked as MIGRATE_ISOLATE. What's
6823 * more, all pages in [start, end) are free in page allocator.
6824 * What we are going to do is to allocate all pages from
6825 * [start, end) (that is remove them from page allocator).
6827 * The only problem is that pages at the beginning and at the
6828 * end of interesting range may be not aligned with pages that
6829 * page allocator holds, ie. they can be part of higher order
6830 * pages. Because of this, we reserve the bigger range and
6831 * once this is done free the pages we are not interested in.
6833 * We don't have to hold zone->lock here because the pages are
6834 * isolated thus they won't get removed from buddy.
6837 lru_add_drain_all();
6838 drain_all_pages(cc
.zone
);
6841 outer_start
= start
;
6842 while (!PageBuddy(pfn_to_page(outer_start
))) {
6843 if (++order
>= MAX_ORDER
) {
6847 outer_start
&= ~0UL << order
;
6850 /* Make sure the range is really isolated. */
6851 if (test_pages_isolated(outer_start
, end
, false)) {
6852 pr_info_ratelimited("%s: [%lx, %lx) PFNs busy\n",
6853 __func__
, outer_start
, end
);
6858 /* Grab isolated pages from freelists. */
6859 outer_end
= isolate_freepages_range(&cc
, outer_start
, end
);
6865 /* Free head and tail (if any) */
6866 if (start
!= outer_start
)
6867 free_contig_range(outer_start
, start
- outer_start
);
6868 if (end
!= outer_end
)
6869 free_contig_range(end
, outer_end
- end
);
6872 undo_isolate_page_range(pfn_max_align_down(start
),
6873 pfn_max_align_up(end
), migratetype
);
6877 void free_contig_range(unsigned long pfn
, unsigned nr_pages
)
6879 unsigned int count
= 0;
6881 for (; nr_pages
--; pfn
++) {
6882 struct page
*page
= pfn_to_page(pfn
);
6884 count
+= page_count(page
) != 1;
6887 WARN(count
!= 0, "%d pages are still in use!\n", count
);
6891 #ifdef CONFIG_MEMORY_HOTPLUG
6893 * The zone indicated has a new number of managed_pages; batch sizes and percpu
6894 * page high values need to be recalulated.
6896 void __meminit
zone_pcp_update(struct zone
*zone
)
6899 mutex_lock(&pcp_batch_high_lock
);
6900 for_each_possible_cpu(cpu
)
6901 pageset_set_high_and_batch(zone
,
6902 per_cpu_ptr(zone
->pageset
, cpu
));
6903 mutex_unlock(&pcp_batch_high_lock
);
6907 void zone_pcp_reset(struct zone
*zone
)
6909 unsigned long flags
;
6911 struct per_cpu_pageset
*pset
;
6913 /* avoid races with drain_pages() */
6914 local_irq_save(flags
);
6915 if (zone
->pageset
!= &boot_pageset
) {
6916 for_each_online_cpu(cpu
) {
6917 pset
= per_cpu_ptr(zone
->pageset
, cpu
);
6918 drain_zonestat(zone
, pset
);
6920 free_percpu(zone
->pageset
);
6921 zone
->pageset
= &boot_pageset
;
6923 local_irq_restore(flags
);
6926 #ifdef CONFIG_MEMORY_HOTREMOVE
6928 * All pages in the range must be isolated before calling this.
6931 __offline_isolated_pages(unsigned long start_pfn
, unsigned long end_pfn
)
6935 unsigned int order
, i
;
6937 unsigned long flags
;
6938 /* find the first valid pfn */
6939 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++)
6944 zone
= page_zone(pfn_to_page(pfn
));
6945 spin_lock_irqsave(&zone
->lock
, flags
);
6947 while (pfn
< end_pfn
) {
6948 if (!pfn_valid(pfn
)) {
6952 page
= pfn_to_page(pfn
);
6954 * The HWPoisoned page may be not in buddy system, and
6955 * page_count() is not 0.
6957 if (unlikely(!PageBuddy(page
) && PageHWPoison(page
))) {
6959 SetPageReserved(page
);
6963 BUG_ON(page_count(page
));
6964 BUG_ON(!PageBuddy(page
));
6965 order
= page_order(page
);
6966 #ifdef CONFIG_DEBUG_VM
6967 printk(KERN_INFO
"remove from free list %lx %d %lx\n",
6968 pfn
, 1 << order
, end_pfn
);
6970 list_del(&page
->lru
);
6971 rmv_page_order(page
);
6972 zone
->free_area
[order
].nr_free
--;
6973 for (i
= 0; i
< (1 << order
); i
++)
6974 SetPageReserved((page
+i
));
6975 pfn
+= (1 << order
);
6977 spin_unlock_irqrestore(&zone
->lock
, flags
);
6981 #ifdef CONFIG_MEMORY_FAILURE
6982 bool is_free_buddy_page(struct page
*page
)
6984 struct zone
*zone
= page_zone(page
);
6985 unsigned long pfn
= page_to_pfn(page
);
6986 unsigned long flags
;
6989 spin_lock_irqsave(&zone
->lock
, flags
);
6990 for (order
= 0; order
< MAX_ORDER
; order
++) {
6991 struct page
*page_head
= page
- (pfn
& ((1 << order
) - 1));
6993 if (PageBuddy(page_head
) && page_order(page_head
) >= order
)
6996 spin_unlock_irqrestore(&zone
->lock
, flags
);
6998 return order
< MAX_ORDER
;