1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_MMZONE_H
3 #define _LINUX_MMZONE_H
6 #ifndef __GENERATING_BOUNDS_H
8 #include <linux/spinlock.h>
9 #include <linux/list.h>
10 #include <linux/wait.h>
11 #include <linux/bitops.h>
12 #include <linux/cache.h>
13 #include <linux/threads.h>
14 #include <linux/numa.h>
15 #include <linux/init.h>
16 #include <linux/seqlock.h>
17 #include <linux/nodemask.h>
18 #include <linux/pageblock-flags.h>
19 #include <linux/page-flags-layout.h>
20 #include <linux/atomic.h>
21 #include <linux/mm_types.h>
22 #include <linux/page-flags.h>
25 /* Free memory management - zoned buddy allocator. */
26 #ifndef CONFIG_FORCE_MAX_ZONEORDER
29 #define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER
31 #define MAX_ORDER_NR_PAGES (1 << (MAX_ORDER - 1))
34 * PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed
35 * costly to service. That is between allocation orders which should
36 * coalesce naturally under reasonable reclaim pressure and those which
39 #define PAGE_ALLOC_COSTLY_ORDER 3
45 MIGRATE_PCPTYPES
, /* the number of types on the pcp lists */
46 MIGRATE_HIGHATOMIC
= MIGRATE_PCPTYPES
,
49 * MIGRATE_CMA migration type is designed to mimic the way
50 * ZONE_MOVABLE works. Only movable pages can be allocated
51 * from MIGRATE_CMA pageblocks and page allocator never
52 * implicitly change migration type of MIGRATE_CMA pageblock.
54 * The way to use it is to change migratetype of a range of
55 * pageblocks to MIGRATE_CMA which can be done by
56 * __free_pageblock_cma() function. What is important though
57 * is that a range of pageblocks must be aligned to
58 * MAX_ORDER_NR_PAGES should biggest page be bigger then
63 #ifdef CONFIG_MEMORY_ISOLATION
64 MIGRATE_ISOLATE
, /* can't allocate from here */
69 /* In mm/page_alloc.c; keep in sync also with show_migration_types() there */
70 extern const char * const migratetype_names
[MIGRATE_TYPES
];
73 # define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA)
74 # define is_migrate_cma_page(_page) (get_pageblock_migratetype(_page) == MIGRATE_CMA)
76 # define is_migrate_cma(migratetype) false
77 # define is_migrate_cma_page(_page) false
80 static inline bool is_migrate_movable(int mt
)
82 return is_migrate_cma(mt
) || mt
== MIGRATE_MOVABLE
;
85 #define for_each_migratetype_order(order, type) \
86 for (order = 0; order < MAX_ORDER; order++) \
87 for (type = 0; type < MIGRATE_TYPES; type++)
89 extern int page_group_by_mobility_disabled
;
91 #define NR_MIGRATETYPE_BITS (PB_migrate_end - PB_migrate + 1)
92 #define MIGRATETYPE_MASK ((1UL << NR_MIGRATETYPE_BITS) - 1)
94 #define get_pageblock_migratetype(page) \
95 get_pfnblock_flags_mask(page, page_to_pfn(page), \
96 PB_migrate_end, MIGRATETYPE_MASK)
99 struct list_head free_list
[MIGRATE_TYPES
];
100 unsigned long nr_free
;
103 /* Used for pages not on another list */
104 static inline void add_to_free_area(struct page
*page
, struct free_area
*area
,
107 list_add(&page
->lru
, &area
->free_list
[migratetype
]);
111 /* Used for pages not on another list */
112 static inline void add_to_free_area_tail(struct page
*page
, struct free_area
*area
,
115 list_add_tail(&page
->lru
, &area
->free_list
[migratetype
]);
119 #ifdef CONFIG_SHUFFLE_PAGE_ALLOCATOR
120 /* Used to preserve page allocation order entropy */
121 void add_to_free_area_random(struct page
*page
, struct free_area
*area
,
124 static inline void add_to_free_area_random(struct page
*page
,
125 struct free_area
*area
, int migratetype
)
127 add_to_free_area(page
, area
, migratetype
);
131 /* Used for pages which are on another list */
132 static inline void move_to_free_area(struct page
*page
, struct free_area
*area
,
135 list_move(&page
->lru
, &area
->free_list
[migratetype
]);
138 static inline struct page
*get_page_from_free_area(struct free_area
*area
,
141 return list_first_entry_or_null(&area
->free_list
[migratetype
],
145 static inline void del_page_from_free_area(struct page
*page
,
146 struct free_area
*area
)
148 list_del(&page
->lru
);
149 __ClearPageBuddy(page
);
150 set_page_private(page
, 0);
154 static inline bool free_area_empty(struct free_area
*area
, int migratetype
)
156 return list_empty(&area
->free_list
[migratetype
]);
162 * zone->lock and the zone lru_lock are two of the hottest locks in the kernel.
163 * So add a wild amount of padding here to ensure that they fall into separate
164 * cachelines. There are very few zone structures in the machine, so space
165 * consumption is not a concern here.
167 #if defined(CONFIG_SMP)
168 struct zone_padding
{
170 } ____cacheline_internodealigned_in_smp
;
171 #define ZONE_PADDING(name) struct zone_padding name;
173 #define ZONE_PADDING(name)
177 enum numa_stat_item
{
178 NUMA_HIT
, /* allocated in intended node */
179 NUMA_MISS
, /* allocated in non intended node */
180 NUMA_FOREIGN
, /* was intended here, hit elsewhere */
181 NUMA_INTERLEAVE_HIT
, /* interleaver preferred this zone */
182 NUMA_LOCAL
, /* allocation from local node */
183 NUMA_OTHER
, /* allocation from other node */
184 NR_VM_NUMA_STAT_ITEMS
187 #define NR_VM_NUMA_STAT_ITEMS 0
190 enum zone_stat_item
{
191 /* First 128 byte cacheline (assuming 64 bit words) */
193 NR_ZONE_LRU_BASE
, /* Used only for compaction and reclaim retry */
194 NR_ZONE_INACTIVE_ANON
= NR_ZONE_LRU_BASE
,
196 NR_ZONE_INACTIVE_FILE
,
199 NR_ZONE_WRITE_PENDING
, /* Count of dirty, writeback and unstable pages */
200 NR_MLOCK
, /* mlock()ed pages found and moved off LRU */
201 NR_PAGETABLE
, /* used for pagetables */
202 NR_KERNEL_STACK_KB
, /* measured in KiB */
203 /* Second 128 byte cacheline */
205 #if IS_ENABLED(CONFIG_ZSMALLOC)
206 NR_ZSPAGES
, /* allocated in zsmalloc */
209 NR_VM_ZONE_STAT_ITEMS
};
211 enum node_stat_item
{
213 NR_INACTIVE_ANON
= NR_LRU_BASE
, /* must match order of LRU_[IN]ACTIVE */
214 NR_ACTIVE_ANON
, /* " " " " " */
215 NR_INACTIVE_FILE
, /* " " " " " */
216 NR_ACTIVE_FILE
, /* " " " " " */
217 NR_UNEVICTABLE
, /* " " " " " */
218 NR_SLAB_RECLAIMABLE
, /* Please do not reorder this item */
219 NR_SLAB_UNRECLAIMABLE
, /* and this one without looking at
220 * memcg_flush_percpu_vmstats() first. */
221 NR_ISOLATED_ANON
, /* Temporary isolated pages from anon lru */
222 NR_ISOLATED_FILE
, /* Temporary isolated pages from file lru */
227 WORKINGSET_NODERECLAIM
,
228 NR_ANON_MAPPED
, /* Mapped anonymous pages */
229 NR_FILE_MAPPED
, /* pagecache pages mapped into pagetables.
230 only modified from process context */
234 NR_WRITEBACK_TEMP
, /* Writeback using temporary buffers */
235 NR_SHMEM
, /* shmem pages (included tmpfs/GEM pages) */
241 NR_UNSTABLE_NFS
, /* NFS unstable pages */
243 NR_VMSCAN_IMMEDIATE
, /* Prioritise for reclaim when writeback ends */
244 NR_DIRTIED
, /* page dirtyings since bootup */
245 NR_WRITTEN
, /* page writings since bootup */
246 NR_KERNEL_MISC_RECLAIMABLE
, /* reclaimable non-slab kernel pages */
247 NR_VM_NODE_STAT_ITEMS
251 * We do arithmetic on the LRU lists in various places in the code,
252 * so it is important to keep the active lists LRU_ACTIVE higher in
253 * the array than the corresponding inactive lists, and to keep
254 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists.
256 * This has to be kept in sync with the statistics in zone_stat_item
257 * above and the descriptions in vmstat_text in mm/vmstat.c
264 LRU_INACTIVE_ANON
= LRU_BASE
,
265 LRU_ACTIVE_ANON
= LRU_BASE
+ LRU_ACTIVE
,
266 LRU_INACTIVE_FILE
= LRU_BASE
+ LRU_FILE
,
267 LRU_ACTIVE_FILE
= LRU_BASE
+ LRU_FILE
+ LRU_ACTIVE
,
272 #define for_each_lru(lru) for (lru = 0; lru < NR_LRU_LISTS; lru++)
274 #define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_ACTIVE_FILE; lru++)
276 static inline int is_file_lru(enum lru_list lru
)
278 return (lru
== LRU_INACTIVE_FILE
|| lru
== LRU_ACTIVE_FILE
);
281 static inline int is_active_lru(enum lru_list lru
)
283 return (lru
== LRU_ACTIVE_ANON
|| lru
== LRU_ACTIVE_FILE
);
286 struct zone_reclaim_stat
{
288 * The pageout code in vmscan.c keeps track of how many of the
289 * mem/swap backed and file backed pages are referenced.
290 * The higher the rotated/scanned ratio, the more valuable
293 * The anon LRU stats live in [0], file LRU stats in [1]
295 unsigned long recent_rotated
[2];
296 unsigned long recent_scanned
[2];
300 struct list_head lists
[NR_LRU_LISTS
];
301 struct zone_reclaim_stat reclaim_stat
;
302 /* Evictions & activations on the inactive file list */
303 atomic_long_t inactive_age
;
304 /* Refaults at the time of last reclaim cycle */
305 unsigned long refaults
;
307 struct pglist_data
*pgdat
;
311 /* Isolate unmapped file */
312 #define ISOLATE_UNMAPPED ((__force isolate_mode_t)0x2)
313 /* Isolate for asynchronous migration */
314 #define ISOLATE_ASYNC_MIGRATE ((__force isolate_mode_t)0x4)
315 /* Isolate unevictable pages */
316 #define ISOLATE_UNEVICTABLE ((__force isolate_mode_t)0x8)
318 /* LRU Isolation modes. */
319 typedef unsigned __bitwise isolate_mode_t
;
321 enum zone_watermarks
{
328 #define min_wmark_pages(z) (z->_watermark[WMARK_MIN] + z->watermark_boost)
329 #define low_wmark_pages(z) (z->_watermark[WMARK_LOW] + z->watermark_boost)
330 #define high_wmark_pages(z) (z->_watermark[WMARK_HIGH] + z->watermark_boost)
331 #define wmark_pages(z, i) (z->_watermark[i] + z->watermark_boost)
333 struct per_cpu_pages
{
334 int count
; /* number of pages in the list */
335 int high
; /* high watermark, emptying needed */
336 int batch
; /* chunk size for buddy add/remove */
338 /* Lists of pages, one per migrate type stored on the pcp-lists */
339 struct list_head lists
[MIGRATE_PCPTYPES
];
342 struct per_cpu_pageset
{
343 struct per_cpu_pages pcp
;
346 u16 vm_numa_stat_diff
[NR_VM_NUMA_STAT_ITEMS
];
350 s8 vm_stat_diff
[NR_VM_ZONE_STAT_ITEMS
];
354 struct per_cpu_nodestat
{
356 s8 vm_node_stat_diff
[NR_VM_NODE_STAT_ITEMS
];
359 #endif /* !__GENERATING_BOUNDS.H */
362 #ifdef CONFIG_ZONE_DMA
364 * ZONE_DMA is used when there are devices that are not able
365 * to do DMA to all of addressable memory (ZONE_NORMAL). Then we
366 * carve out the portion of memory that is needed for these devices.
367 * The range is arch specific.
372 * ---------------------------
373 * parisc, ia64, sparc <4G
376 * alpha Unlimited or 0-16MB.
378 * i386, x86_64 and multiple other arches
383 #ifdef CONFIG_ZONE_DMA32
385 * x86_64 needs two ZONE_DMAs because it supports devices that are
386 * only able to do DMA to the lower 16M but also 32 bit devices that
387 * can only do DMA areas below 4G.
392 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be
393 * performed on pages in ZONE_NORMAL if the DMA devices support
394 * transfers to all addressable memory.
397 #ifdef CONFIG_HIGHMEM
399 * A memory area that is only addressable by the kernel through
400 * mapping portions into its own address space. This is for example
401 * used by i386 to allow the kernel to address the memory beyond
402 * 900MB. The kernel will set up special mappings (page
403 * table entries on i386) for each page that the kernel needs to
409 #ifdef CONFIG_ZONE_DEVICE
416 #ifndef __GENERATING_BOUNDS_H
419 /* Read-mostly fields */
421 /* zone watermarks, access with *_wmark_pages(zone) macros */
422 unsigned long _watermark
[NR_WMARK
];
423 unsigned long watermark_boost
;
425 unsigned long nr_reserved_highatomic
;
428 * We don't know if the memory that we're going to allocate will be
429 * freeable or/and it will be released eventually, so to avoid totally
430 * wasting several GB of ram we must reserve some of the lower zone
431 * memory (otherwise we risk to run OOM on the lower zones despite
432 * there being tons of freeable ram on the higher zones). This array is
433 * recalculated at runtime if the sysctl_lowmem_reserve_ratio sysctl
436 long lowmem_reserve
[MAX_NR_ZONES
];
441 struct pglist_data
*zone_pgdat
;
442 struct per_cpu_pageset __percpu
*pageset
;
444 #ifndef CONFIG_SPARSEMEM
446 * Flags for a pageblock_nr_pages block. See pageblock-flags.h.
447 * In SPARSEMEM, this map is stored in struct mem_section
449 unsigned long *pageblock_flags
;
450 #endif /* CONFIG_SPARSEMEM */
452 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
453 unsigned long zone_start_pfn
;
456 * spanned_pages is the total pages spanned by the zone, including
457 * holes, which is calculated as:
458 * spanned_pages = zone_end_pfn - zone_start_pfn;
460 * present_pages is physical pages existing within the zone, which
462 * present_pages = spanned_pages - absent_pages(pages in holes);
464 * managed_pages is present pages managed by the buddy system, which
465 * is calculated as (reserved_pages includes pages allocated by the
466 * bootmem allocator):
467 * managed_pages = present_pages - reserved_pages;
469 * So present_pages may be used by memory hotplug or memory power
470 * management logic to figure out unmanaged pages by checking
471 * (present_pages - managed_pages). And managed_pages should be used
472 * by page allocator and vm scanner to calculate all kinds of watermarks
477 * zone_start_pfn and spanned_pages are protected by span_seqlock.
478 * It is a seqlock because it has to be read outside of zone->lock,
479 * and it is done in the main allocator path. But, it is written
480 * quite infrequently.
482 * The span_seq lock is declared along with zone->lock because it is
483 * frequently read in proximity to zone->lock. It's good to
484 * give them a chance of being in the same cacheline.
486 * Write access to present_pages at runtime should be protected by
487 * mem_hotplug_begin/end(). Any reader who can't tolerant drift of
488 * present_pages should get_online_mems() to get a stable value.
490 atomic_long_t managed_pages
;
491 unsigned long spanned_pages
;
492 unsigned long present_pages
;
496 #ifdef CONFIG_MEMORY_ISOLATION
498 * Number of isolated pageblock. It is used to solve incorrect
499 * freepage counting problem due to racy retrieving migratetype
500 * of pageblock. Protected by zone->lock.
502 unsigned long nr_isolate_pageblock
;
505 #ifdef CONFIG_MEMORY_HOTPLUG
506 /* see spanned/present_pages for more description */
507 seqlock_t span_seqlock
;
512 /* Write-intensive fields used from the page allocator */
515 /* free areas of different sizes */
516 struct free_area free_area
[MAX_ORDER
];
518 /* zone flags, see below */
521 /* Primarily protects free_area */
524 /* Write-intensive fields used by compaction and vmstats. */
528 * When free pages are below this point, additional steps are taken
529 * when reading the number of free pages to avoid per-cpu counter
530 * drift allowing watermarks to be breached
532 unsigned long percpu_drift_mark
;
534 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
535 /* pfn where compaction free scanner should start */
536 unsigned long compact_cached_free_pfn
;
537 /* pfn where async and sync compaction migration scanner should start */
538 unsigned long compact_cached_migrate_pfn
[2];
539 unsigned long compact_init_migrate_pfn
;
540 unsigned long compact_init_free_pfn
;
543 #ifdef CONFIG_COMPACTION
545 * On compaction failure, 1<<compact_defer_shift compactions
546 * are skipped before trying again. The number attempted since
547 * last failure is tracked with compact_considered.
549 unsigned int compact_considered
;
550 unsigned int compact_defer_shift
;
551 int compact_order_failed
;
554 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
555 /* Set to true when the PG_migrate_skip bits should be cleared */
556 bool compact_blockskip_flush
;
562 /* Zone statistics */
563 atomic_long_t vm_stat
[NR_VM_ZONE_STAT_ITEMS
];
564 atomic_long_t vm_numa_stat
[NR_VM_NUMA_STAT_ITEMS
];
565 } ____cacheline_internodealigned_in_smp
;
568 PGDAT_CONGESTED
, /* pgdat has many dirty pages backed by
571 PGDAT_DIRTY
, /* reclaim scanning has recently found
572 * many dirty file pages at the tail
575 PGDAT_WRITEBACK
, /* reclaim scanning has recently found
576 * many pages under writeback
578 PGDAT_RECLAIM_LOCKED
, /* prevents concurrent reclaim */
582 ZONE_BOOSTED_WATERMARK
, /* zone recently boosted watermarks.
583 * Cleared when kswapd is woken.
587 static inline unsigned long zone_managed_pages(struct zone
*zone
)
589 return (unsigned long)atomic_long_read(&zone
->managed_pages
);
592 static inline unsigned long zone_end_pfn(const struct zone
*zone
)
594 return zone
->zone_start_pfn
+ zone
->spanned_pages
;
597 static inline bool zone_spans_pfn(const struct zone
*zone
, unsigned long pfn
)
599 return zone
->zone_start_pfn
<= pfn
&& pfn
< zone_end_pfn(zone
);
602 static inline bool zone_is_initialized(struct zone
*zone
)
604 return zone
->initialized
;
607 static inline bool zone_is_empty(struct zone
*zone
)
609 return zone
->spanned_pages
== 0;
613 * Return true if [start_pfn, start_pfn + nr_pages) range has a non-empty
614 * intersection with the given zone
616 static inline bool zone_intersects(struct zone
*zone
,
617 unsigned long start_pfn
, unsigned long nr_pages
)
619 if (zone_is_empty(zone
))
621 if (start_pfn
>= zone_end_pfn(zone
) ||
622 start_pfn
+ nr_pages
<= zone
->zone_start_pfn
)
629 * The "priority" of VM scanning is how much of the queues we will scan in one
630 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
631 * queues ("queue_length >> 12") during an aging round.
633 #define DEF_PRIORITY 12
635 /* Maximum number of zones on a zonelist */
636 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
639 ZONELIST_FALLBACK
, /* zonelist with fallback */
642 * The NUMA zonelists are doubled because we need zonelists that
643 * restrict the allocations to a single node for __GFP_THISNODE.
645 ZONELIST_NOFALLBACK
, /* zonelist without fallback (__GFP_THISNODE) */
651 * This struct contains information about a zone in a zonelist. It is stored
652 * here to avoid dereferences into large structures and lookups of tables
655 struct zone
*zone
; /* Pointer to actual zone */
656 int zone_idx
; /* zone_idx(zoneref->zone) */
660 * One allocation request operates on a zonelist. A zonelist
661 * is a list of zones, the first one is the 'goal' of the
662 * allocation, the other zones are fallback zones, in decreasing
665 * To speed the reading of the zonelist, the zonerefs contain the zone index
666 * of the entry being read. Helper functions to access information given
667 * a struct zoneref are
669 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs
670 * zonelist_zone_idx() - Return the index of the zone for an entry
671 * zonelist_node_idx() - Return the index of the node for an entry
674 struct zoneref _zonerefs
[MAX_ZONES_PER_ZONELIST
+ 1];
677 #ifndef CONFIG_DISCONTIGMEM
678 /* The array of struct pages - for discontigmem use pgdat->lmem_map */
679 extern struct page
*mem_map
;
682 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
683 struct deferred_split
{
684 spinlock_t split_queue_lock
;
685 struct list_head split_queue
;
686 unsigned long split_queue_len
;
691 * On NUMA machines, each NUMA node would have a pg_data_t to describe
692 * it's memory layout. On UMA machines there is a single pglist_data which
693 * describes the whole memory.
695 * Memory statistics and page replacement data structures are maintained on a
699 typedef struct pglist_data
{
700 struct zone node_zones
[MAX_NR_ZONES
];
701 struct zonelist node_zonelists
[MAX_ZONELISTS
];
703 #ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */
704 struct page
*node_mem_map
;
705 #ifdef CONFIG_PAGE_EXTENSION
706 struct page_ext
*node_page_ext
;
709 #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT)
711 * Must be held any time you expect node_start_pfn,
712 * node_present_pages, node_spanned_pages or nr_zones to stay constant.
714 * pgdat_resize_lock() and pgdat_resize_unlock() are provided to
715 * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG
716 * or CONFIG_DEFERRED_STRUCT_PAGE_INIT.
718 * Nests above zone->lock and zone->span_seqlock
720 spinlock_t node_size_lock
;
722 unsigned long node_start_pfn
;
723 unsigned long node_present_pages
; /* total number of physical pages */
724 unsigned long node_spanned_pages
; /* total size of physical page
725 range, including holes */
727 wait_queue_head_t kswapd_wait
;
728 wait_queue_head_t pfmemalloc_wait
;
729 struct task_struct
*kswapd
; /* Protected by
730 mem_hotplug_begin/end() */
732 enum zone_type kswapd_classzone_idx
;
734 int kswapd_failures
; /* Number of 'reclaimed == 0' runs */
736 #ifdef CONFIG_COMPACTION
737 int kcompactd_max_order
;
738 enum zone_type kcompactd_classzone_idx
;
739 wait_queue_head_t kcompactd_wait
;
740 struct task_struct
*kcompactd
;
743 * This is a per-node reserve of pages that are not available
744 * to userspace allocations.
746 unsigned long totalreserve_pages
;
750 * zone reclaim becomes active if more unmapped pages exist.
752 unsigned long min_unmapped_pages
;
753 unsigned long min_slab_pages
;
754 #endif /* CONFIG_NUMA */
756 /* Write-intensive fields used by page reclaim */
760 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
762 * If memory initialisation on large machines is deferred then this
763 * is the first PFN that needs to be initialised.
765 unsigned long first_deferred_pfn
;
766 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
768 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
769 struct deferred_split deferred_split_queue
;
772 /* Fields commonly accessed by the page reclaim scanner */
773 struct lruvec lruvec
;
779 /* Per-node vmstats */
780 struct per_cpu_nodestat __percpu
*per_cpu_nodestats
;
781 atomic_long_t vm_stat
[NR_VM_NODE_STAT_ITEMS
];
784 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
785 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
786 #ifdef CONFIG_FLAT_NODE_MEM_MAP
787 #define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr))
789 #define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr))
791 #define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr))
793 #define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn)
794 #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid))
796 static inline struct lruvec
*node_lruvec(struct pglist_data
*pgdat
)
798 return &pgdat
->lruvec
;
801 static inline unsigned long pgdat_end_pfn(pg_data_t
*pgdat
)
803 return pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
806 static inline bool pgdat_is_empty(pg_data_t
*pgdat
)
808 return !pgdat
->node_start_pfn
&& !pgdat
->node_spanned_pages
;
811 #include <linux/memory_hotplug.h>
813 void build_all_zonelists(pg_data_t
*pgdat
);
814 void wakeup_kswapd(struct zone
*zone
, gfp_t gfp_mask
, int order
,
815 enum zone_type classzone_idx
);
816 bool __zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
817 int classzone_idx
, unsigned int alloc_flags
,
819 bool zone_watermark_ok(struct zone
*z
, unsigned int order
,
820 unsigned long mark
, int classzone_idx
,
821 unsigned int alloc_flags
);
822 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
823 unsigned long mark
, int classzone_idx
);
824 enum memmap_context
{
828 extern void init_currently_empty_zone(struct zone
*zone
, unsigned long start_pfn
,
831 extern void lruvec_init(struct lruvec
*lruvec
);
833 static inline struct pglist_data
*lruvec_pgdat(struct lruvec
*lruvec
)
836 return lruvec
->pgdat
;
838 return container_of(lruvec
, struct pglist_data
, lruvec
);
842 extern unsigned long lruvec_lru_size(struct lruvec
*lruvec
, enum lru_list lru
, int zone_idx
);
844 #ifdef CONFIG_HAVE_MEMORY_PRESENT
845 void memory_present(int nid
, unsigned long start
, unsigned long end
);
847 static inline void memory_present(int nid
, unsigned long start
, unsigned long end
) {}
850 #if defined(CONFIG_SPARSEMEM)
851 void memblocks_present(void);
853 static inline void memblocks_present(void) {}
856 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
857 int local_memory_node(int node_id
);
859 static inline int local_memory_node(int node_id
) { return node_id
; };
863 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
865 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones)
868 * Returns true if a zone has pages managed by the buddy allocator.
869 * All the reclaim decisions have to use this function rather than
870 * populated_zone(). If the whole zone is reserved then we can easily
871 * end up with populated_zone() && !managed_zone().
873 static inline bool managed_zone(struct zone
*zone
)
875 return zone_managed_pages(zone
);
878 /* Returns true if a zone has memory */
879 static inline bool populated_zone(struct zone
*zone
)
881 return zone
->present_pages
;
885 static inline int zone_to_nid(struct zone
*zone
)
890 static inline void zone_set_nid(struct zone
*zone
, int nid
)
895 static inline int zone_to_nid(struct zone
*zone
)
900 static inline void zone_set_nid(struct zone
*zone
, int nid
) {}
903 extern int movable_zone
;
905 #ifdef CONFIG_HIGHMEM
906 static inline int zone_movable_is_highmem(void)
908 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
909 return movable_zone
== ZONE_HIGHMEM
;
911 return (ZONE_MOVABLE
- 1) == ZONE_HIGHMEM
;
916 static inline int is_highmem_idx(enum zone_type idx
)
918 #ifdef CONFIG_HIGHMEM
919 return (idx
== ZONE_HIGHMEM
||
920 (idx
== ZONE_MOVABLE
&& zone_movable_is_highmem()));
927 * is_highmem - helper function to quickly check if a struct zone is a
928 * highmem zone or not. This is an attempt to keep references
929 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
930 * @zone - pointer to struct zone variable
932 static inline int is_highmem(struct zone
*zone
)
934 #ifdef CONFIG_HIGHMEM
935 return is_highmem_idx(zone_idx(zone
));
941 /* These two functions are used to setup the per zone pages min values */
943 int min_free_kbytes_sysctl_handler(struct ctl_table
*, int,
944 void __user
*, size_t *, loff_t
*);
945 int watermark_boost_factor_sysctl_handler(struct ctl_table
*, int,
946 void __user
*, size_t *, loff_t
*);
947 int watermark_scale_factor_sysctl_handler(struct ctl_table
*, int,
948 void __user
*, size_t *, loff_t
*);
949 extern int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
];
950 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*, int,
951 void __user
*, size_t *, loff_t
*);
952 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*, int,
953 void __user
*, size_t *, loff_t
*);
954 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*, int,
955 void __user
*, size_t *, loff_t
*);
956 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*, int,
957 void __user
*, size_t *, loff_t
*);
959 extern int numa_zonelist_order_handler(struct ctl_table
*, int,
960 void __user
*, size_t *, loff_t
*);
961 extern char numa_zonelist_order
[];
962 #define NUMA_ZONELIST_ORDER_LEN 16
964 #ifndef CONFIG_NEED_MULTIPLE_NODES
966 extern struct pglist_data contig_page_data
;
967 #define NODE_DATA(nid) (&contig_page_data)
968 #define NODE_MEM_MAP(nid) mem_map
970 #else /* CONFIG_NEED_MULTIPLE_NODES */
972 #include <asm/mmzone.h>
974 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
976 extern struct pglist_data
*first_online_pgdat(void);
977 extern struct pglist_data
*next_online_pgdat(struct pglist_data
*pgdat
);
978 extern struct zone
*next_zone(struct zone
*zone
);
981 * for_each_online_pgdat - helper macro to iterate over all online nodes
982 * @pgdat - pointer to a pg_data_t variable
984 #define for_each_online_pgdat(pgdat) \
985 for (pgdat = first_online_pgdat(); \
987 pgdat = next_online_pgdat(pgdat))
989 * for_each_zone - helper macro to iterate over all memory zones
990 * @zone - pointer to struct zone variable
992 * The user only needs to declare the zone variable, for_each_zone
995 #define for_each_zone(zone) \
996 for (zone = (first_online_pgdat())->node_zones; \
998 zone = next_zone(zone))
1000 #define for_each_populated_zone(zone) \
1001 for (zone = (first_online_pgdat())->node_zones; \
1003 zone = next_zone(zone)) \
1004 if (!populated_zone(zone)) \
1005 ; /* do nothing */ \
1008 static inline struct zone
*zonelist_zone(struct zoneref
*zoneref
)
1010 return zoneref
->zone
;
1013 static inline int zonelist_zone_idx(struct zoneref
*zoneref
)
1015 return zoneref
->zone_idx
;
1018 static inline int zonelist_node_idx(struct zoneref
*zoneref
)
1020 return zone_to_nid(zoneref
->zone
);
1023 struct zoneref
*__next_zones_zonelist(struct zoneref
*z
,
1024 enum zone_type highest_zoneidx
,
1028 * next_zones_zonelist - Returns the next zone at or below highest_zoneidx within the allowed nodemask using a cursor within a zonelist as a starting point
1029 * @z - The cursor used as a starting point for the search
1030 * @highest_zoneidx - The zone index of the highest zone to return
1031 * @nodes - An optional nodemask to filter the zonelist with
1033 * This function returns the next zone at or below a given zone index that is
1034 * within the allowed nodemask using a cursor as the starting point for the
1035 * search. The zoneref returned is a cursor that represents the current zone
1036 * being examined. It should be advanced by one before calling
1037 * next_zones_zonelist again.
1039 static __always_inline
struct zoneref
*next_zones_zonelist(struct zoneref
*z
,
1040 enum zone_type highest_zoneidx
,
1043 if (likely(!nodes
&& zonelist_zone_idx(z
) <= highest_zoneidx
))
1045 return __next_zones_zonelist(z
, highest_zoneidx
, nodes
);
1049 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
1050 * @zonelist - The zonelist to search for a suitable zone
1051 * @highest_zoneidx - The zone index of the highest zone to return
1052 * @nodes - An optional nodemask to filter the zonelist with
1053 * @return - Zoneref pointer for the first suitable zone found (see below)
1055 * This function returns the first zone at or below a given zone index that is
1056 * within the allowed nodemask. The zoneref returned is a cursor that can be
1057 * used to iterate the zonelist with next_zones_zonelist by advancing it by
1058 * one before calling.
1060 * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is
1061 * never NULL). This may happen either genuinely, or due to concurrent nodemask
1062 * update due to cpuset modification.
1064 static inline struct zoneref
*first_zones_zonelist(struct zonelist
*zonelist
,
1065 enum zone_type highest_zoneidx
,
1068 return next_zones_zonelist(zonelist
->_zonerefs
,
1069 highest_zoneidx
, nodes
);
1073 * for_each_zone_zonelist_nodemask - helper macro to iterate over valid zones in a zonelist at or below a given zone index and within a nodemask
1074 * @zone - The current zone in the iterator
1075 * @z - The current pointer within zonelist->zones being iterated
1076 * @zlist - The zonelist being iterated
1077 * @highidx - The zone index of the highest zone to return
1078 * @nodemask - Nodemask allowed by the allocator
1080 * This iterator iterates though all zones at or below a given zone index and
1081 * within a given nodemask
1083 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
1084 for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z); \
1086 z = next_zones_zonelist(++z, highidx, nodemask), \
1087 zone = zonelist_zone(z))
1089 #define for_next_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
1090 for (zone = z->zone; \
1092 z = next_zones_zonelist(++z, highidx, nodemask), \
1093 zone = zonelist_zone(z))
1097 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
1098 * @zone - The current zone in the iterator
1099 * @z - The current pointer within zonelist->zones being iterated
1100 * @zlist - The zonelist being iterated
1101 * @highidx - The zone index of the highest zone to return
1103 * This iterator iterates though all zones at or below a given zone index.
1105 #define for_each_zone_zonelist(zone, z, zlist, highidx) \
1106 for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL)
1108 #ifdef CONFIG_SPARSEMEM
1109 #include <asm/sparsemem.h>
1112 #if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \
1113 !defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1114 static inline unsigned long early_pfn_to_nid(unsigned long pfn
)
1116 BUILD_BUG_ON(IS_ENABLED(CONFIG_NUMA
));
1121 #ifdef CONFIG_FLATMEM
1122 #define pfn_to_nid(pfn) (0)
1125 #ifdef CONFIG_SPARSEMEM
1128 * SECTION_SHIFT #bits space required to store a section #
1130 * PA_SECTION_SHIFT physical address to/from section number
1131 * PFN_SECTION_SHIFT pfn to/from section number
1133 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS)
1134 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
1136 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT)
1138 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT)
1139 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1))
1141 #define SECTION_BLOCKFLAGS_BITS \
1142 ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS)
1144 #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
1145 #error Allocator MAX_ORDER exceeds SECTION_SIZE
1148 static inline unsigned long pfn_to_section_nr(unsigned long pfn
)
1150 return pfn
>> PFN_SECTION_SHIFT
;
1152 static inline unsigned long section_nr_to_pfn(unsigned long sec
)
1154 return sec
<< PFN_SECTION_SHIFT
;
1157 #define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK)
1158 #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK)
1160 #define SUBSECTION_SHIFT 21
1162 #define PFN_SUBSECTION_SHIFT (SUBSECTION_SHIFT - PAGE_SHIFT)
1163 #define PAGES_PER_SUBSECTION (1UL << PFN_SUBSECTION_SHIFT)
1164 #define PAGE_SUBSECTION_MASK (~(PAGES_PER_SUBSECTION-1))
1166 #if SUBSECTION_SHIFT > SECTION_SIZE_BITS
1167 #error Subsection size exceeds section size
1169 #define SUBSECTIONS_PER_SECTION (1UL << (SECTION_SIZE_BITS - SUBSECTION_SHIFT))
1172 #define SUBSECTION_ALIGN_UP(pfn) ALIGN((pfn), PAGES_PER_SUBSECTION)
1173 #define SUBSECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SUBSECTION_MASK)
1175 struct mem_section_usage
{
1176 DECLARE_BITMAP(subsection_map
, SUBSECTIONS_PER_SECTION
);
1177 /* See declaration of similar field in struct zone */
1178 unsigned long pageblock_flags
[0];
1181 void subsection_map_init(unsigned long pfn
, unsigned long nr_pages
);
1185 struct mem_section
{
1187 * This is, logically, a pointer to an array of struct
1188 * pages. However, it is stored with some other magic.
1189 * (see sparse.c::sparse_init_one_section())
1191 * Additionally during early boot we encode node id of
1192 * the location of the section here to guide allocation.
1193 * (see sparse.c::memory_present())
1195 * Making it a UL at least makes someone do a cast
1196 * before using it wrong.
1198 unsigned long section_mem_map
;
1200 struct mem_section_usage
*usage
;
1201 #ifdef CONFIG_PAGE_EXTENSION
1203 * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use
1204 * section. (see page_ext.h about this.)
1206 struct page_ext
*page_ext
;
1210 * WARNING: mem_section must be a power-of-2 in size for the
1211 * calculation and use of SECTION_ROOT_MASK to make sense.
1215 #ifdef CONFIG_SPARSEMEM_EXTREME
1216 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section))
1218 #define SECTIONS_PER_ROOT 1
1221 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
1222 #define NR_SECTION_ROOTS DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT)
1223 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1)
1225 #ifdef CONFIG_SPARSEMEM_EXTREME
1226 extern struct mem_section
**mem_section
;
1228 extern struct mem_section mem_section
[NR_SECTION_ROOTS
][SECTIONS_PER_ROOT
];
1231 static inline unsigned long *section_to_usemap(struct mem_section
*ms
)
1233 return ms
->usage
->pageblock_flags
;
1236 static inline struct mem_section
*__nr_to_section(unsigned long nr
)
1238 #ifdef CONFIG_SPARSEMEM_EXTREME
1242 if (!mem_section
[SECTION_NR_TO_ROOT(nr
)])
1244 return &mem_section
[SECTION_NR_TO_ROOT(nr
)][nr
& SECTION_ROOT_MASK
];
1246 extern unsigned long __section_nr(struct mem_section
*ms
);
1247 extern size_t mem_section_usage_size(void);
1250 * We use the lower bits of the mem_map pointer to store
1251 * a little bit of information. The pointer is calculated
1252 * as mem_map - section_nr_to_pfn(pnum). The result is
1253 * aligned to the minimum alignment of the two values:
1254 * 1. All mem_map arrays are page-aligned.
1255 * 2. section_nr_to_pfn() always clears PFN_SECTION_SHIFT
1256 * lowest bits. PFN_SECTION_SHIFT is arch-specific
1257 * (equal SECTION_SIZE_BITS - PAGE_SHIFT), and the
1258 * worst combination is powerpc with 256k pages,
1259 * which results in PFN_SECTION_SHIFT equal 6.
1260 * To sum it up, at least 6 bits are available.
1262 #define SECTION_MARKED_PRESENT (1UL<<0)
1263 #define SECTION_HAS_MEM_MAP (1UL<<1)
1264 #define SECTION_IS_ONLINE (1UL<<2)
1265 #define SECTION_IS_EARLY (1UL<<3)
1266 #define SECTION_MAP_LAST_BIT (1UL<<4)
1267 #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1))
1268 #define SECTION_NID_SHIFT 3
1270 static inline struct page
*__section_mem_map_addr(struct mem_section
*section
)
1272 unsigned long map
= section
->section_mem_map
;
1273 map
&= SECTION_MAP_MASK
;
1274 return (struct page
*)map
;
1277 static inline int present_section(struct mem_section
*section
)
1279 return (section
&& (section
->section_mem_map
& SECTION_MARKED_PRESENT
));
1282 static inline int present_section_nr(unsigned long nr
)
1284 return present_section(__nr_to_section(nr
));
1287 static inline int valid_section(struct mem_section
*section
)
1289 return (section
&& (section
->section_mem_map
& SECTION_HAS_MEM_MAP
));
1292 static inline int early_section(struct mem_section
*section
)
1294 return (section
&& (section
->section_mem_map
& SECTION_IS_EARLY
));
1297 static inline int valid_section_nr(unsigned long nr
)
1299 return valid_section(__nr_to_section(nr
));
1302 static inline int online_section(struct mem_section
*section
)
1304 return (section
&& (section
->section_mem_map
& SECTION_IS_ONLINE
));
1307 static inline int online_section_nr(unsigned long nr
)
1309 return online_section(__nr_to_section(nr
));
1312 #ifdef CONFIG_MEMORY_HOTPLUG
1313 void online_mem_sections(unsigned long start_pfn
, unsigned long end_pfn
);
1314 #ifdef CONFIG_MEMORY_HOTREMOVE
1315 void offline_mem_sections(unsigned long start_pfn
, unsigned long end_pfn
);
1319 static inline struct mem_section
*__pfn_to_section(unsigned long pfn
)
1321 return __nr_to_section(pfn_to_section_nr(pfn
));
1324 extern unsigned long __highest_present_section_nr
;
1326 static inline int subsection_map_index(unsigned long pfn
)
1328 return (pfn
& ~(PAGE_SECTION_MASK
)) / PAGES_PER_SUBSECTION
;
1331 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1332 static inline int pfn_section_valid(struct mem_section
*ms
, unsigned long pfn
)
1334 int idx
= subsection_map_index(pfn
);
1336 return test_bit(idx
, ms
->usage
->subsection_map
);
1339 static inline int pfn_section_valid(struct mem_section
*ms
, unsigned long pfn
)
1345 #ifndef CONFIG_HAVE_ARCH_PFN_VALID
1346 static inline int pfn_valid(unsigned long pfn
)
1348 struct mem_section
*ms
;
1350 if (pfn_to_section_nr(pfn
) >= NR_MEM_SECTIONS
)
1352 ms
= __nr_to_section(pfn_to_section_nr(pfn
));
1353 if (!valid_section(ms
))
1356 * Traditionally early sections always returned pfn_valid() for
1357 * the entire section-sized span.
1359 return early_section(ms
) || pfn_section_valid(ms
, pfn
);
1363 static inline int pfn_present(unsigned long pfn
)
1365 if (pfn_to_section_nr(pfn
) >= NR_MEM_SECTIONS
)
1367 return present_section(__nr_to_section(pfn_to_section_nr(pfn
)));
1371 * These are _only_ used during initialisation, therefore they
1372 * can use __initdata ... They could have names to indicate
1376 #define pfn_to_nid(pfn) \
1378 unsigned long __pfn_to_nid_pfn = (pfn); \
1379 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \
1382 #define pfn_to_nid(pfn) (0)
1385 #define early_pfn_valid(pfn) pfn_valid(pfn)
1386 void sparse_init(void);
1388 #define sparse_init() do {} while (0)
1389 #define sparse_index_init(_sec, _nid) do {} while (0)
1390 #define pfn_present pfn_valid
1391 #define subsection_map_init(_pfn, _nr_pages) do {} while (0)
1392 #endif /* CONFIG_SPARSEMEM */
1395 * During memory init memblocks map pfns to nids. The search is expensive and
1396 * this caches recent lookups. The implementation of __early_pfn_to_nid
1397 * may treat start/end as pfns or sections.
1399 struct mminit_pfnnid_cache
{
1400 unsigned long last_start
;
1401 unsigned long last_end
;
1405 #ifndef early_pfn_valid
1406 #define early_pfn_valid(pfn) (1)
1409 void memory_present(int nid
, unsigned long start
, unsigned long end
);
1412 * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we
1413 * need to check pfn validity within that MAX_ORDER_NR_PAGES block.
1414 * pfn_valid_within() should be used in this case; we optimise this away
1415 * when we have no holes within a MAX_ORDER_NR_PAGES block.
1417 #ifdef CONFIG_HOLES_IN_ZONE
1418 #define pfn_valid_within(pfn) pfn_valid(pfn)
1420 #define pfn_valid_within(pfn) (1)
1423 #ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
1425 * pfn_valid() is meant to be able to tell if a given PFN has valid memmap
1426 * associated with it or not. This means that a struct page exists for this
1427 * pfn. The caller cannot assume the page is fully initialized in general.
1428 * Hotplugable pages might not have been onlined yet. pfn_to_online_page()
1429 * will ensure the struct page is fully online and initialized. Special pages
1430 * (e.g. ZONE_DEVICE) are never onlined and should be treated accordingly.
1432 * In FLATMEM, it is expected that holes always have valid memmap as long as
1433 * there is valid PFNs either side of the hole. In SPARSEMEM, it is assumed
1434 * that a valid section has a memmap for the entire section.
1436 * However, an ARM, and maybe other embedded architectures in the future
1437 * free memmap backing holes to save memory on the assumption the memmap is
1438 * never used. The page_zone linkages are then broken even though pfn_valid()
1439 * returns true. A walker of the full memmap must then do this additional
1440 * check to ensure the memmap they are looking at is sane by making sure
1441 * the zone and PFN linkages are still valid. This is expensive, but walkers
1442 * of the full memmap are extremely rare.
1444 bool memmap_valid_within(unsigned long pfn
,
1445 struct page
*page
, struct zone
*zone
);
1447 static inline bool memmap_valid_within(unsigned long pfn
,
1448 struct page
*page
, struct zone
*zone
)
1452 #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */
1454 #endif /* !__GENERATING_BOUNDS.H */
1455 #endif /* !__ASSEMBLY__ */
1456 #endif /* _LINUX_MMZONE_H */