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 than
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 MIGRATETYPE_MASK ((1UL << PB_migratetype_bits) - 1)
93 #define get_pageblock_migratetype(page) \
94 get_pfnblock_flags_mask(page, page_to_pfn(page), MIGRATETYPE_MASK)
97 struct list_head free_list
[MIGRATE_TYPES
];
98 unsigned long nr_free
;
101 static inline struct page
*get_page_from_free_area(struct free_area
*area
,
104 return list_first_entry_or_null(&area
->free_list
[migratetype
],
108 static inline bool free_area_empty(struct free_area
*area
, int migratetype
)
110 return list_empty(&area
->free_list
[migratetype
]);
116 * Add a wild amount of padding here to ensure datas fall into separate
117 * cachelines. There are very few zone structures in the machine, so space
118 * consumption is not a concern here.
120 #if defined(CONFIG_SMP)
121 struct zone_padding
{
123 } ____cacheline_internodealigned_in_smp
;
124 #define ZONE_PADDING(name) struct zone_padding name;
126 #define ZONE_PADDING(name)
130 enum numa_stat_item
{
131 NUMA_HIT
, /* allocated in intended node */
132 NUMA_MISS
, /* allocated in non intended node */
133 NUMA_FOREIGN
, /* was intended here, hit elsewhere */
134 NUMA_INTERLEAVE_HIT
, /* interleaver preferred this zone */
135 NUMA_LOCAL
, /* allocation from local node */
136 NUMA_OTHER
, /* allocation from other node */
137 NR_VM_NUMA_STAT_ITEMS
140 #define NR_VM_NUMA_STAT_ITEMS 0
143 enum zone_stat_item
{
144 /* First 128 byte cacheline (assuming 64 bit words) */
146 NR_ZONE_LRU_BASE
, /* Used only for compaction and reclaim retry */
147 NR_ZONE_INACTIVE_ANON
= NR_ZONE_LRU_BASE
,
149 NR_ZONE_INACTIVE_FILE
,
152 NR_ZONE_WRITE_PENDING
, /* Count of dirty, writeback and unstable pages */
153 NR_MLOCK
, /* mlock()ed pages found and moved off LRU */
154 /* Second 128 byte cacheline */
156 #if IS_ENABLED(CONFIG_ZSMALLOC)
157 NR_ZSPAGES
, /* allocated in zsmalloc */
160 NR_VM_ZONE_STAT_ITEMS
};
162 enum node_stat_item
{
164 NR_INACTIVE_ANON
= NR_LRU_BASE
, /* must match order of LRU_[IN]ACTIVE */
165 NR_ACTIVE_ANON
, /* " " " " " */
166 NR_INACTIVE_FILE
, /* " " " " " */
167 NR_ACTIVE_FILE
, /* " " " " " */
168 NR_UNEVICTABLE
, /* " " " " " */
169 NR_SLAB_RECLAIMABLE_B
,
170 NR_SLAB_UNRECLAIMABLE_B
,
171 NR_ISOLATED_ANON
, /* Temporary isolated pages from anon lru */
172 NR_ISOLATED_FILE
, /* Temporary isolated pages from file lru */
174 WORKINGSET_REFAULT_BASE
,
175 WORKINGSET_REFAULT_ANON
= WORKINGSET_REFAULT_BASE
,
176 WORKINGSET_REFAULT_FILE
,
177 WORKINGSET_ACTIVATE_BASE
,
178 WORKINGSET_ACTIVATE_ANON
= WORKINGSET_ACTIVATE_BASE
,
179 WORKINGSET_ACTIVATE_FILE
,
180 WORKINGSET_RESTORE_BASE
,
181 WORKINGSET_RESTORE_ANON
= WORKINGSET_RESTORE_BASE
,
182 WORKINGSET_RESTORE_FILE
,
183 WORKINGSET_NODERECLAIM
,
184 NR_ANON_MAPPED
, /* Mapped anonymous pages */
185 NR_FILE_MAPPED
, /* pagecache pages mapped into pagetables.
186 only modified from process context */
190 NR_WRITEBACK_TEMP
, /* Writeback using temporary buffers */
191 NR_SHMEM
, /* shmem pages (included tmpfs/GEM pages) */
198 NR_VMSCAN_IMMEDIATE
, /* Prioritise for reclaim when writeback ends */
199 NR_DIRTIED
, /* page dirtyings since bootup */
200 NR_WRITTEN
, /* page writings since bootup */
201 NR_KERNEL_MISC_RECLAIMABLE
, /* reclaimable non-slab kernel pages */
202 NR_FOLL_PIN_ACQUIRED
, /* via: pin_user_page(), gup flag: FOLL_PIN */
203 NR_FOLL_PIN_RELEASED
, /* pages returned via unpin_user_page() */
204 NR_KERNEL_STACK_KB
, /* measured in KiB */
205 #if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
206 NR_KERNEL_SCS_KB
, /* measured in KiB */
208 NR_PAGETABLE
, /* used for pagetables */
212 NR_VM_NODE_STAT_ITEMS
216 * Returns true if the item should be printed in THPs (/proc/vmstat
217 * currently prints number of anon, file and shmem THPs. But the item
218 * is charged in pages).
220 static __always_inline
bool vmstat_item_print_in_thp(enum node_stat_item item
)
222 if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE
))
225 return item
== NR_ANON_THPS
||
226 item
== NR_FILE_THPS
||
227 item
== NR_SHMEM_THPS
||
228 item
== NR_SHMEM_PMDMAPPED
||
229 item
== NR_FILE_PMDMAPPED
;
233 * Returns true if the value is measured in bytes (most vmstat values are
234 * measured in pages). This defines the API part, the internal representation
235 * might be different.
237 static __always_inline
bool vmstat_item_in_bytes(int idx
)
240 * Global and per-node slab counters track slab pages.
241 * It's expected that changes are multiples of PAGE_SIZE.
242 * Internally values are stored in pages.
244 * Per-memcg and per-lruvec counters track memory, consumed
245 * by individual slab objects. These counters are actually
248 return (idx
== NR_SLAB_RECLAIMABLE_B
||
249 idx
== NR_SLAB_UNRECLAIMABLE_B
);
253 * We do arithmetic on the LRU lists in various places in the code,
254 * so it is important to keep the active lists LRU_ACTIVE higher in
255 * the array than the corresponding inactive lists, and to keep
256 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists.
258 * This has to be kept in sync with the statistics in zone_stat_item
259 * above and the descriptions in vmstat_text in mm/vmstat.c
266 LRU_INACTIVE_ANON
= LRU_BASE
,
267 LRU_ACTIVE_ANON
= LRU_BASE
+ LRU_ACTIVE
,
268 LRU_INACTIVE_FILE
= LRU_BASE
+ LRU_FILE
,
269 LRU_ACTIVE_FILE
= LRU_BASE
+ LRU_FILE
+ LRU_ACTIVE
,
274 #define for_each_lru(lru) for (lru = 0; lru < NR_LRU_LISTS; lru++)
276 #define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_ACTIVE_FILE; lru++)
278 static inline bool is_file_lru(enum lru_list lru
)
280 return (lru
== LRU_INACTIVE_FILE
|| lru
== LRU_ACTIVE_FILE
);
283 static inline bool is_active_lru(enum lru_list lru
)
285 return (lru
== LRU_ACTIVE_ANON
|| lru
== LRU_ACTIVE_FILE
);
288 #define ANON_AND_FILE 2
291 LRUVEC_CONGESTED
, /* lruvec has many dirty pages
292 * backed by a congested BDI
297 struct list_head lists
[NR_LRU_LISTS
];
298 /* per lruvec lru_lock for memcg */
301 * These track the cost of reclaiming one LRU - file or anon -
302 * over the other. As the observed cost of reclaiming one LRU
303 * increases, the reclaim scan balance tips toward the other.
305 unsigned long anon_cost
;
306 unsigned long file_cost
;
307 /* Non-resident age, driven by LRU movement */
308 atomic_long_t nonresident_age
;
309 /* Refaults at the time of last reclaim cycle */
310 unsigned long refaults
[ANON_AND_FILE
];
311 /* Various lruvec state flags (enum lruvec_flags) */
314 struct pglist_data
*pgdat
;
318 /* Isolate unmapped pages */
319 #define ISOLATE_UNMAPPED ((__force isolate_mode_t)0x2)
320 /* Isolate for asynchronous migration */
321 #define ISOLATE_ASYNC_MIGRATE ((__force isolate_mode_t)0x4)
322 /* Isolate unevictable pages */
323 #define ISOLATE_UNEVICTABLE ((__force isolate_mode_t)0x8)
325 /* LRU Isolation modes. */
326 typedef unsigned __bitwise isolate_mode_t
;
328 enum zone_watermarks
{
335 #define min_wmark_pages(z) (z->_watermark[WMARK_MIN] + z->watermark_boost)
336 #define low_wmark_pages(z) (z->_watermark[WMARK_LOW] + z->watermark_boost)
337 #define high_wmark_pages(z) (z->_watermark[WMARK_HIGH] + z->watermark_boost)
338 #define wmark_pages(z, i) (z->_watermark[i] + z->watermark_boost)
340 struct per_cpu_pages
{
341 int count
; /* number of pages in the list */
342 int high
; /* high watermark, emptying needed */
343 int batch
; /* chunk size for buddy add/remove */
345 /* Lists of pages, one per migrate type stored on the pcp-lists */
346 struct list_head lists
[MIGRATE_PCPTYPES
];
349 struct per_cpu_pageset
{
350 struct per_cpu_pages pcp
;
353 u16 vm_numa_stat_diff
[NR_VM_NUMA_STAT_ITEMS
];
357 s8 vm_stat_diff
[NR_VM_ZONE_STAT_ITEMS
];
361 struct per_cpu_nodestat
{
363 s8 vm_node_stat_diff
[NR_VM_NODE_STAT_ITEMS
];
366 #endif /* !__GENERATING_BOUNDS.H */
370 * ZONE_DMA and ZONE_DMA32 are used when there are peripherals not able
371 * to DMA to all of the addressable memory (ZONE_NORMAL).
372 * On architectures where this area covers the whole 32 bit address
373 * space ZONE_DMA32 is used. ZONE_DMA is left for the ones with smaller
374 * DMA addressing constraints. This distinction is important as a 32bit
375 * DMA mask is assumed when ZONE_DMA32 is defined. Some 64-bit
376 * platforms may need both zones as they support peripherals with
377 * different DMA addressing limitations.
379 #ifdef CONFIG_ZONE_DMA
382 #ifdef CONFIG_ZONE_DMA32
386 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be
387 * performed on pages in ZONE_NORMAL if the DMA devices support
388 * transfers to all addressable memory.
391 #ifdef CONFIG_HIGHMEM
393 * A memory area that is only addressable by the kernel through
394 * mapping portions into its own address space. This is for example
395 * used by i386 to allow the kernel to address the memory beyond
396 * 900MB. The kernel will set up special mappings (page
397 * table entries on i386) for each page that the kernel needs to
403 * ZONE_MOVABLE is similar to ZONE_NORMAL, except that it contains
404 * movable pages with few exceptional cases described below. Main use
405 * cases for ZONE_MOVABLE are to make memory offlining/unplug more
406 * likely to succeed, and to locally limit unmovable allocations - e.g.,
407 * to increase the number of THP/huge pages. Notable special cases are:
409 * 1. Pinned pages: (long-term) pinning of movable pages might
410 * essentially turn such pages unmovable. Therefore, we do not allow
411 * pinning long-term pages in ZONE_MOVABLE. When pages are pinned and
412 * faulted, they come from the right zone right away. However, it is
413 * still possible that address space already has pages in
414 * ZONE_MOVABLE at the time when pages are pinned (i.e. user has
415 * touches that memory before pinning). In such case we migrate them
416 * to a different zone. When migration fails - pinning fails.
417 * 2. memblock allocations: kernelcore/movablecore setups might create
418 * situations where ZONE_MOVABLE contains unmovable allocations
419 * after boot. Memory offlining and allocations fail early.
420 * 3. Memory holes: kernelcore/movablecore setups might create very rare
421 * situations where ZONE_MOVABLE contains memory holes after boot,
422 * for example, if we have sections that are only partially
423 * populated. Memory offlining and allocations fail early.
424 * 4. PG_hwpoison pages: while poisoned pages can be skipped during
425 * memory offlining, such pages cannot be allocated.
426 * 5. Unmovable PG_offline pages: in paravirtualized environments,
427 * hotplugged memory blocks might only partially be managed by the
428 * buddy (e.g., via XEN-balloon, Hyper-V balloon, virtio-mem). The
429 * parts not manged by the buddy are unmovable PG_offline pages. In
430 * some cases (virtio-mem), such pages can be skipped during
431 * memory offlining, however, cannot be moved/allocated. These
432 * techniques might use alloc_contig_range() to hide previously
433 * exposed pages from the buddy again (e.g., to implement some sort
434 * of memory unplug in virtio-mem).
435 * 6. ZERO_PAGE(0), kernelcore/movablecore setups might create
436 * situations where ZERO_PAGE(0) which is allocated differently
437 * on different platforms may end up in a movable zone. ZERO_PAGE(0)
438 * cannot be migrated.
439 * 7. Memory-hotplug: when using memmap_on_memory and onlining the
440 * memory to the MOVABLE zone, the vmemmap pages are also placed in
441 * such zone. Such pages cannot be really moved around as they are
442 * self-stored in the range, but they are treated as movable when
443 * the range they describe is about to be offlined.
445 * In general, no unmovable allocations that degrade memory offlining
446 * should end up in ZONE_MOVABLE. Allocators (like alloc_contig_range())
447 * have to expect that migrating pages in ZONE_MOVABLE can fail (even
448 * if has_unmovable_pages() states that there are no unmovable pages,
449 * there can be false negatives).
452 #ifdef CONFIG_ZONE_DEVICE
459 #ifndef __GENERATING_BOUNDS_H
461 #define ASYNC_AND_SYNC 2
464 /* Read-mostly fields */
466 /* zone watermarks, access with *_wmark_pages(zone) macros */
467 unsigned long _watermark
[NR_WMARK
];
468 unsigned long watermark_boost
;
470 unsigned long nr_reserved_highatomic
;
473 * We don't know if the memory that we're going to allocate will be
474 * freeable or/and it will be released eventually, so to avoid totally
475 * wasting several GB of ram we must reserve some of the lower zone
476 * memory (otherwise we risk to run OOM on the lower zones despite
477 * there being tons of freeable ram on the higher zones). This array is
478 * recalculated at runtime if the sysctl_lowmem_reserve_ratio sysctl
481 long lowmem_reserve
[MAX_NR_ZONES
];
486 struct pglist_data
*zone_pgdat
;
487 struct per_cpu_pageset __percpu
*pageset
;
489 * the high and batch values are copied to individual pagesets for
495 #ifndef CONFIG_SPARSEMEM
497 * Flags for a pageblock_nr_pages block. See pageblock-flags.h.
498 * In SPARSEMEM, this map is stored in struct mem_section
500 unsigned long *pageblock_flags
;
501 #endif /* CONFIG_SPARSEMEM */
503 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
504 unsigned long zone_start_pfn
;
507 * spanned_pages is the total pages spanned by the zone, including
508 * holes, which is calculated as:
509 * spanned_pages = zone_end_pfn - zone_start_pfn;
511 * present_pages is physical pages existing within the zone, which
513 * present_pages = spanned_pages - absent_pages(pages in holes);
515 * managed_pages is present pages managed by the buddy system, which
516 * is calculated as (reserved_pages includes pages allocated by the
517 * bootmem allocator):
518 * managed_pages = present_pages - reserved_pages;
520 * cma pages is present pages that are assigned for CMA use
523 * So present_pages may be used by memory hotplug or memory power
524 * management logic to figure out unmanaged pages by checking
525 * (present_pages - managed_pages). And managed_pages should be used
526 * by page allocator and vm scanner to calculate all kinds of watermarks
531 * zone_start_pfn and spanned_pages are protected by span_seqlock.
532 * It is a seqlock because it has to be read outside of zone->lock,
533 * and it is done in the main allocator path. But, it is written
534 * quite infrequently.
536 * The span_seq lock is declared along with zone->lock because it is
537 * frequently read in proximity to zone->lock. It's good to
538 * give them a chance of being in the same cacheline.
540 * Write access to present_pages at runtime should be protected by
541 * mem_hotplug_begin/end(). Any reader who can't tolerant drift of
542 * present_pages should get_online_mems() to get a stable value.
544 atomic_long_t managed_pages
;
545 unsigned long spanned_pages
;
546 unsigned long present_pages
;
548 unsigned long cma_pages
;
553 #ifdef CONFIG_MEMORY_ISOLATION
555 * Number of isolated pageblock. It is used to solve incorrect
556 * freepage counting problem due to racy retrieving migratetype
557 * of pageblock. Protected by zone->lock.
559 unsigned long nr_isolate_pageblock
;
562 #ifdef CONFIG_MEMORY_HOTPLUG
563 /* see spanned/present_pages for more description */
564 seqlock_t span_seqlock
;
569 /* Write-intensive fields used from the page allocator */
572 /* free areas of different sizes */
573 struct free_area free_area
[MAX_ORDER
];
575 /* zone flags, see below */
578 /* Primarily protects free_area */
581 /* Write-intensive fields used by compaction and vmstats. */
585 * When free pages are below this point, additional steps are taken
586 * when reading the number of free pages to avoid per-cpu counter
587 * drift allowing watermarks to be breached
589 unsigned long percpu_drift_mark
;
591 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
592 /* pfn where compaction free scanner should start */
593 unsigned long compact_cached_free_pfn
;
594 /* pfn where compaction migration scanner should start */
595 unsigned long compact_cached_migrate_pfn
[ASYNC_AND_SYNC
];
596 unsigned long compact_init_migrate_pfn
;
597 unsigned long compact_init_free_pfn
;
600 #ifdef CONFIG_COMPACTION
602 * On compaction failure, 1<<compact_defer_shift compactions
603 * are skipped before trying again. The number attempted since
604 * last failure is tracked with compact_considered.
605 * compact_order_failed is the minimum compaction failed order.
607 unsigned int compact_considered
;
608 unsigned int compact_defer_shift
;
609 int compact_order_failed
;
612 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
613 /* Set to true when the PG_migrate_skip bits should be cleared */
614 bool compact_blockskip_flush
;
620 /* Zone statistics */
621 atomic_long_t vm_stat
[NR_VM_ZONE_STAT_ITEMS
];
622 atomic_long_t vm_numa_stat
[NR_VM_NUMA_STAT_ITEMS
];
623 } ____cacheline_internodealigned_in_smp
;
626 PGDAT_DIRTY
, /* reclaim scanning has recently found
627 * many dirty file pages at the tail
630 PGDAT_WRITEBACK
, /* reclaim scanning has recently found
631 * many pages under writeback
633 PGDAT_RECLAIM_LOCKED
, /* prevents concurrent reclaim */
637 ZONE_BOOSTED_WATERMARK
, /* zone recently boosted watermarks.
638 * Cleared when kswapd is woken.
642 static inline unsigned long zone_managed_pages(struct zone
*zone
)
644 return (unsigned long)atomic_long_read(&zone
->managed_pages
);
647 static inline unsigned long zone_cma_pages(struct zone
*zone
)
650 return zone
->cma_pages
;
656 static inline unsigned long zone_end_pfn(const struct zone
*zone
)
658 return zone
->zone_start_pfn
+ zone
->spanned_pages
;
661 static inline bool zone_spans_pfn(const struct zone
*zone
, unsigned long pfn
)
663 return zone
->zone_start_pfn
<= pfn
&& pfn
< zone_end_pfn(zone
);
666 static inline bool zone_is_initialized(struct zone
*zone
)
668 return zone
->initialized
;
671 static inline bool zone_is_empty(struct zone
*zone
)
673 return zone
->spanned_pages
== 0;
677 * Return true if [start_pfn, start_pfn + nr_pages) range has a non-empty
678 * intersection with the given zone
680 static inline bool zone_intersects(struct zone
*zone
,
681 unsigned long start_pfn
, unsigned long nr_pages
)
683 if (zone_is_empty(zone
))
685 if (start_pfn
>= zone_end_pfn(zone
) ||
686 start_pfn
+ nr_pages
<= zone
->zone_start_pfn
)
693 * The "priority" of VM scanning is how much of the queues we will scan in one
694 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
695 * queues ("queue_length >> 12") during an aging round.
697 #define DEF_PRIORITY 12
699 /* Maximum number of zones on a zonelist */
700 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
703 ZONELIST_FALLBACK
, /* zonelist with fallback */
706 * The NUMA zonelists are doubled because we need zonelists that
707 * restrict the allocations to a single node for __GFP_THISNODE.
709 ZONELIST_NOFALLBACK
, /* zonelist without fallback (__GFP_THISNODE) */
715 * This struct contains information about a zone in a zonelist. It is stored
716 * here to avoid dereferences into large structures and lookups of tables
719 struct zone
*zone
; /* Pointer to actual zone */
720 int zone_idx
; /* zone_idx(zoneref->zone) */
724 * One allocation request operates on a zonelist. A zonelist
725 * is a list of zones, the first one is the 'goal' of the
726 * allocation, the other zones are fallback zones, in decreasing
729 * To speed the reading of the zonelist, the zonerefs contain the zone index
730 * of the entry being read. Helper functions to access information given
731 * a struct zoneref are
733 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs
734 * zonelist_zone_idx() - Return the index of the zone for an entry
735 * zonelist_node_idx() - Return the index of the node for an entry
738 struct zoneref _zonerefs
[MAX_ZONES_PER_ZONELIST
+ 1];
741 #ifndef CONFIG_DISCONTIGMEM
742 /* The array of struct pages - for discontigmem use pgdat->lmem_map */
743 extern struct page
*mem_map
;
746 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
747 struct deferred_split
{
748 spinlock_t split_queue_lock
;
749 struct list_head split_queue
;
750 unsigned long split_queue_len
;
755 * On NUMA machines, each NUMA node would have a pg_data_t to describe
756 * it's memory layout. On UMA machines there is a single pglist_data which
757 * describes the whole memory.
759 * Memory statistics and page replacement data structures are maintained on a
762 typedef struct pglist_data
{
764 * node_zones contains just the zones for THIS node. Not all of the
765 * zones may be populated, but it is the full list. It is referenced by
766 * this node's node_zonelists as well as other node's node_zonelists.
768 struct zone node_zones
[MAX_NR_ZONES
];
771 * node_zonelists contains references to all zones in all nodes.
772 * Generally the first zones will be references to this node's
775 struct zonelist node_zonelists
[MAX_ZONELISTS
];
777 int nr_zones
; /* number of populated zones in this node */
778 #ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */
779 struct page
*node_mem_map
;
780 #ifdef CONFIG_PAGE_EXTENSION
781 struct page_ext
*node_page_ext
;
784 #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT)
786 * Must be held any time you expect node_start_pfn,
787 * node_present_pages, node_spanned_pages or nr_zones to stay constant.
788 * Also synchronizes pgdat->first_deferred_pfn during deferred page
791 * pgdat_resize_lock() and pgdat_resize_unlock() are provided to
792 * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG
793 * or CONFIG_DEFERRED_STRUCT_PAGE_INIT.
795 * Nests above zone->lock and zone->span_seqlock
797 spinlock_t node_size_lock
;
799 unsigned long node_start_pfn
;
800 unsigned long node_present_pages
; /* total number of physical pages */
801 unsigned long node_spanned_pages
; /* total size of physical page
802 range, including holes */
804 wait_queue_head_t kswapd_wait
;
805 wait_queue_head_t pfmemalloc_wait
;
806 struct task_struct
*kswapd
; /* Protected by
807 mem_hotplug_begin/end() */
809 enum zone_type kswapd_highest_zoneidx
;
811 int kswapd_failures
; /* Number of 'reclaimed == 0' runs */
813 #ifdef CONFIG_COMPACTION
814 int kcompactd_max_order
;
815 enum zone_type kcompactd_highest_zoneidx
;
816 wait_queue_head_t kcompactd_wait
;
817 struct task_struct
*kcompactd
;
820 * This is a per-node reserve of pages that are not available
821 * to userspace allocations.
823 unsigned long totalreserve_pages
;
827 * node reclaim becomes active if more unmapped pages exist.
829 unsigned long min_unmapped_pages
;
830 unsigned long min_slab_pages
;
831 #endif /* CONFIG_NUMA */
833 /* Write-intensive fields used by page reclaim */
836 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
838 * If memory initialisation on large machines is deferred then this
839 * is the first PFN that needs to be initialised.
841 unsigned long first_deferred_pfn
;
842 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
844 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
845 struct deferred_split deferred_split_queue
;
848 /* Fields commonly accessed by the page reclaim scanner */
851 * NOTE: THIS IS UNUSED IF MEMCG IS ENABLED.
853 * Use mem_cgroup_lruvec() to look up lruvecs.
855 struct lruvec __lruvec
;
861 /* Per-node vmstats */
862 struct per_cpu_nodestat __percpu
*per_cpu_nodestats
;
863 atomic_long_t vm_stat
[NR_VM_NODE_STAT_ITEMS
];
866 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
867 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
868 #ifdef CONFIG_FLAT_NODE_MEM_MAP
869 #define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr))
871 #define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr))
873 #define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr))
875 #define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn)
876 #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid))
878 static inline unsigned long pgdat_end_pfn(pg_data_t
*pgdat
)
880 return pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
;
883 static inline bool pgdat_is_empty(pg_data_t
*pgdat
)
885 return !pgdat
->node_start_pfn
&& !pgdat
->node_spanned_pages
;
888 #include <linux/memory_hotplug.h>
890 void build_all_zonelists(pg_data_t
*pgdat
);
891 void wakeup_kswapd(struct zone
*zone
, gfp_t gfp_mask
, int order
,
892 enum zone_type highest_zoneidx
);
893 bool __zone_watermark_ok(struct zone
*z
, unsigned int order
, unsigned long mark
,
894 int highest_zoneidx
, unsigned int alloc_flags
,
896 bool zone_watermark_ok(struct zone
*z
, unsigned int order
,
897 unsigned long mark
, int highest_zoneidx
,
898 unsigned int alloc_flags
);
899 bool zone_watermark_ok_safe(struct zone
*z
, unsigned int order
,
900 unsigned long mark
, int highest_zoneidx
);
902 * Memory initialization context, use to differentiate memory added by
903 * the platform statically or via memory hotplug interface.
905 enum meminit_context
{
910 extern void init_currently_empty_zone(struct zone
*zone
, unsigned long start_pfn
,
913 extern void lruvec_init(struct lruvec
*lruvec
);
915 static inline struct pglist_data
*lruvec_pgdat(struct lruvec
*lruvec
)
918 return lruvec
->pgdat
;
920 return container_of(lruvec
, struct pglist_data
, __lruvec
);
924 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
925 int local_memory_node(int node_id
);
927 static inline int local_memory_node(int node_id
) { return node_id
; };
931 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
933 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones)
935 #ifdef CONFIG_ZONE_DEVICE
936 static inline bool zone_is_zone_device(struct zone
*zone
)
938 return zone_idx(zone
) == ZONE_DEVICE
;
941 static inline bool zone_is_zone_device(struct zone
*zone
)
948 * Returns true if a zone has pages managed by the buddy allocator.
949 * All the reclaim decisions have to use this function rather than
950 * populated_zone(). If the whole zone is reserved then we can easily
951 * end up with populated_zone() && !managed_zone().
953 static inline bool managed_zone(struct zone
*zone
)
955 return zone_managed_pages(zone
);
958 /* Returns true if a zone has memory */
959 static inline bool populated_zone(struct zone
*zone
)
961 return zone
->present_pages
;
965 static inline int zone_to_nid(struct zone
*zone
)
970 static inline void zone_set_nid(struct zone
*zone
, int nid
)
975 static inline int zone_to_nid(struct zone
*zone
)
980 static inline void zone_set_nid(struct zone
*zone
, int nid
) {}
983 extern int movable_zone
;
985 #ifdef CONFIG_HIGHMEM
986 static inline int zone_movable_is_highmem(void)
988 #ifdef CONFIG_NEED_MULTIPLE_NODES
989 return movable_zone
== ZONE_HIGHMEM
;
991 return (ZONE_MOVABLE
- 1) == ZONE_HIGHMEM
;
996 static inline int is_highmem_idx(enum zone_type idx
)
998 #ifdef CONFIG_HIGHMEM
999 return (idx
== ZONE_HIGHMEM
||
1000 (idx
== ZONE_MOVABLE
&& zone_movable_is_highmem()));
1007 * is_highmem - helper function to quickly check if a struct zone is a
1008 * highmem zone or not. This is an attempt to keep references
1009 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
1010 * @zone: pointer to struct zone variable
1011 * Return: 1 for a highmem zone, 0 otherwise
1013 static inline int is_highmem(struct zone
*zone
)
1015 #ifdef CONFIG_HIGHMEM
1016 return is_highmem_idx(zone_idx(zone
));
1022 /* These two functions are used to setup the per zone pages min values */
1025 int min_free_kbytes_sysctl_handler(struct ctl_table
*, int, void *, size_t *,
1027 int watermark_scale_factor_sysctl_handler(struct ctl_table
*, int, void *,
1028 size_t *, loff_t
*);
1029 extern int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
];
1030 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*, int, void *,
1031 size_t *, loff_t
*);
1032 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*, int,
1033 void *, size_t *, loff_t
*);
1034 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*, int,
1035 void *, size_t *, loff_t
*);
1036 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*, int,
1037 void *, size_t *, loff_t
*);
1038 int numa_zonelist_order_handler(struct ctl_table
*, int,
1039 void *, size_t *, loff_t
*);
1040 extern int percpu_pagelist_fraction
;
1041 extern char numa_zonelist_order
[];
1042 #define NUMA_ZONELIST_ORDER_LEN 16
1044 #ifndef CONFIG_NEED_MULTIPLE_NODES
1046 extern struct pglist_data contig_page_data
;
1047 #define NODE_DATA(nid) (&contig_page_data)
1048 #define NODE_MEM_MAP(nid) mem_map
1050 #else /* CONFIG_NEED_MULTIPLE_NODES */
1052 #include <asm/mmzone.h>
1054 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
1056 extern struct pglist_data
*first_online_pgdat(void);
1057 extern struct pglist_data
*next_online_pgdat(struct pglist_data
*pgdat
);
1058 extern struct zone
*next_zone(struct zone
*zone
);
1061 * for_each_online_pgdat - helper macro to iterate over all online nodes
1062 * @pgdat: pointer to a pg_data_t variable
1064 #define for_each_online_pgdat(pgdat) \
1065 for (pgdat = first_online_pgdat(); \
1067 pgdat = next_online_pgdat(pgdat))
1069 * for_each_zone - helper macro to iterate over all memory zones
1070 * @zone: pointer to struct zone variable
1072 * The user only needs to declare the zone variable, for_each_zone
1075 #define for_each_zone(zone) \
1076 for (zone = (first_online_pgdat())->node_zones; \
1078 zone = next_zone(zone))
1080 #define for_each_populated_zone(zone) \
1081 for (zone = (first_online_pgdat())->node_zones; \
1083 zone = next_zone(zone)) \
1084 if (!populated_zone(zone)) \
1085 ; /* do nothing */ \
1088 static inline struct zone
*zonelist_zone(struct zoneref
*zoneref
)
1090 return zoneref
->zone
;
1093 static inline int zonelist_zone_idx(struct zoneref
*zoneref
)
1095 return zoneref
->zone_idx
;
1098 static inline int zonelist_node_idx(struct zoneref
*zoneref
)
1100 return zone_to_nid(zoneref
->zone
);
1103 struct zoneref
*__next_zones_zonelist(struct zoneref
*z
,
1104 enum zone_type highest_zoneidx
,
1108 * 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
1109 * @z: The cursor used as a starting point for the search
1110 * @highest_zoneidx: The zone index of the highest zone to return
1111 * @nodes: An optional nodemask to filter the zonelist with
1113 * This function returns the next zone at or below a given zone index that is
1114 * within the allowed nodemask using a cursor as the starting point for the
1115 * search. The zoneref returned is a cursor that represents the current zone
1116 * being examined. It should be advanced by one before calling
1117 * next_zones_zonelist again.
1119 * Return: the next zone at or below highest_zoneidx within the allowed
1120 * nodemask using a cursor within a zonelist as a starting point
1122 static __always_inline
struct zoneref
*next_zones_zonelist(struct zoneref
*z
,
1123 enum zone_type highest_zoneidx
,
1126 if (likely(!nodes
&& zonelist_zone_idx(z
) <= highest_zoneidx
))
1128 return __next_zones_zonelist(z
, highest_zoneidx
, nodes
);
1132 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
1133 * @zonelist: The zonelist to search for a suitable zone
1134 * @highest_zoneidx: The zone index of the highest zone to return
1135 * @nodes: An optional nodemask to filter the zonelist with
1137 * This function returns the first zone at or below a given zone index that is
1138 * within the allowed nodemask. The zoneref returned is a cursor that can be
1139 * used to iterate the zonelist with next_zones_zonelist by advancing it by
1140 * one before calling.
1142 * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is
1143 * never NULL). This may happen either genuinely, or due to concurrent nodemask
1144 * update due to cpuset modification.
1146 * Return: Zoneref pointer for the first suitable zone found
1148 static inline struct zoneref
*first_zones_zonelist(struct zonelist
*zonelist
,
1149 enum zone_type highest_zoneidx
,
1152 return next_zones_zonelist(zonelist
->_zonerefs
,
1153 highest_zoneidx
, nodes
);
1157 * 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
1158 * @zone: The current zone in the iterator
1159 * @z: The current pointer within zonelist->_zonerefs being iterated
1160 * @zlist: The zonelist being iterated
1161 * @highidx: The zone index of the highest zone to return
1162 * @nodemask: Nodemask allowed by the allocator
1164 * This iterator iterates though all zones at or below a given zone index and
1165 * within a given nodemask
1167 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
1168 for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z); \
1170 z = next_zones_zonelist(++z, highidx, nodemask), \
1171 zone = zonelist_zone(z))
1173 #define for_next_zone_zonelist_nodemask(zone, z, highidx, nodemask) \
1174 for (zone = z->zone; \
1176 z = next_zones_zonelist(++z, highidx, nodemask), \
1177 zone = zonelist_zone(z))
1181 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
1182 * @zone: The current zone in the iterator
1183 * @z: The current pointer within zonelist->zones being iterated
1184 * @zlist: The zonelist being iterated
1185 * @highidx: The zone index of the highest zone to return
1187 * This iterator iterates though all zones at or below a given zone index.
1189 #define for_each_zone_zonelist(zone, z, zlist, highidx) \
1190 for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL)
1192 #ifdef CONFIG_SPARSEMEM
1193 #include <asm/sparsemem.h>
1196 #ifdef CONFIG_FLATMEM
1197 #define pfn_to_nid(pfn) (0)
1200 #ifdef CONFIG_SPARSEMEM
1203 * SECTION_SHIFT #bits space required to store a section #
1205 * PA_SECTION_SHIFT physical address to/from section number
1206 * PFN_SECTION_SHIFT pfn to/from section number
1208 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS)
1209 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
1211 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT)
1213 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT)
1214 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1))
1216 #define SECTION_BLOCKFLAGS_BITS \
1217 ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS)
1219 #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
1220 #error Allocator MAX_ORDER exceeds SECTION_SIZE
1223 static inline unsigned long pfn_to_section_nr(unsigned long pfn
)
1225 return pfn
>> PFN_SECTION_SHIFT
;
1227 static inline unsigned long section_nr_to_pfn(unsigned long sec
)
1229 return sec
<< PFN_SECTION_SHIFT
;
1232 #define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK)
1233 #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK)
1235 #define SUBSECTION_SHIFT 21
1236 #define SUBSECTION_SIZE (1UL << SUBSECTION_SHIFT)
1238 #define PFN_SUBSECTION_SHIFT (SUBSECTION_SHIFT - PAGE_SHIFT)
1239 #define PAGES_PER_SUBSECTION (1UL << PFN_SUBSECTION_SHIFT)
1240 #define PAGE_SUBSECTION_MASK (~(PAGES_PER_SUBSECTION-1))
1242 #if SUBSECTION_SHIFT > SECTION_SIZE_BITS
1243 #error Subsection size exceeds section size
1245 #define SUBSECTIONS_PER_SECTION (1UL << (SECTION_SIZE_BITS - SUBSECTION_SHIFT))
1248 #define SUBSECTION_ALIGN_UP(pfn) ALIGN((pfn), PAGES_PER_SUBSECTION)
1249 #define SUBSECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SUBSECTION_MASK)
1251 struct mem_section_usage
{
1252 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1253 DECLARE_BITMAP(subsection_map
, SUBSECTIONS_PER_SECTION
);
1255 /* See declaration of similar field in struct zone */
1256 unsigned long pageblock_flags
[0];
1259 void subsection_map_init(unsigned long pfn
, unsigned long nr_pages
);
1263 struct mem_section
{
1265 * This is, logically, a pointer to an array of struct
1266 * pages. However, it is stored with some other magic.
1267 * (see sparse.c::sparse_init_one_section())
1269 * Additionally during early boot we encode node id of
1270 * the location of the section here to guide allocation.
1271 * (see sparse.c::memory_present())
1273 * Making it a UL at least makes someone do a cast
1274 * before using it wrong.
1276 unsigned long section_mem_map
;
1278 struct mem_section_usage
*usage
;
1279 #ifdef CONFIG_PAGE_EXTENSION
1281 * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use
1282 * section. (see page_ext.h about this.)
1284 struct page_ext
*page_ext
;
1288 * WARNING: mem_section must be a power-of-2 in size for the
1289 * calculation and use of SECTION_ROOT_MASK to make sense.
1293 #ifdef CONFIG_SPARSEMEM_EXTREME
1294 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section))
1296 #define SECTIONS_PER_ROOT 1
1299 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
1300 #define NR_SECTION_ROOTS DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT)
1301 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1)
1303 #ifdef CONFIG_SPARSEMEM_EXTREME
1304 extern struct mem_section
**mem_section
;
1306 extern struct mem_section mem_section
[NR_SECTION_ROOTS
][SECTIONS_PER_ROOT
];
1309 static inline unsigned long *section_to_usemap(struct mem_section
*ms
)
1311 return ms
->usage
->pageblock_flags
;
1314 static inline struct mem_section
*__nr_to_section(unsigned long nr
)
1316 #ifdef CONFIG_SPARSEMEM_EXTREME
1320 if (!mem_section
[SECTION_NR_TO_ROOT(nr
)])
1322 return &mem_section
[SECTION_NR_TO_ROOT(nr
)][nr
& SECTION_ROOT_MASK
];
1324 extern unsigned long __section_nr(struct mem_section
*ms
);
1325 extern size_t mem_section_usage_size(void);
1328 * We use the lower bits of the mem_map pointer to store
1329 * a little bit of information. The pointer is calculated
1330 * as mem_map - section_nr_to_pfn(pnum). The result is
1331 * aligned to the minimum alignment of the two values:
1332 * 1. All mem_map arrays are page-aligned.
1333 * 2. section_nr_to_pfn() always clears PFN_SECTION_SHIFT
1334 * lowest bits. PFN_SECTION_SHIFT is arch-specific
1335 * (equal SECTION_SIZE_BITS - PAGE_SHIFT), and the
1336 * worst combination is powerpc with 256k pages,
1337 * which results in PFN_SECTION_SHIFT equal 6.
1338 * To sum it up, at least 6 bits are available.
1340 #define SECTION_MARKED_PRESENT (1UL<<0)
1341 #define SECTION_HAS_MEM_MAP (1UL<<1)
1342 #define SECTION_IS_ONLINE (1UL<<2)
1343 #define SECTION_IS_EARLY (1UL<<3)
1344 #define SECTION_TAINT_ZONE_DEVICE (1UL<<4)
1345 #define SECTION_MAP_LAST_BIT (1UL<<5)
1346 #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1))
1347 #define SECTION_NID_SHIFT 3
1349 static inline struct page
*__section_mem_map_addr(struct mem_section
*section
)
1351 unsigned long map
= section
->section_mem_map
;
1352 map
&= SECTION_MAP_MASK
;
1353 return (struct page
*)map
;
1356 static inline int present_section(struct mem_section
*section
)
1358 return (section
&& (section
->section_mem_map
& SECTION_MARKED_PRESENT
));
1361 static inline int present_section_nr(unsigned long nr
)
1363 return present_section(__nr_to_section(nr
));
1366 static inline int valid_section(struct mem_section
*section
)
1368 return (section
&& (section
->section_mem_map
& SECTION_HAS_MEM_MAP
));
1371 static inline int early_section(struct mem_section
*section
)
1373 return (section
&& (section
->section_mem_map
& SECTION_IS_EARLY
));
1376 static inline int valid_section_nr(unsigned long nr
)
1378 return valid_section(__nr_to_section(nr
));
1381 static inline int online_section(struct mem_section
*section
)
1383 return (section
&& (section
->section_mem_map
& SECTION_IS_ONLINE
));
1386 static inline int online_device_section(struct mem_section
*section
)
1388 unsigned long flags
= SECTION_IS_ONLINE
| SECTION_TAINT_ZONE_DEVICE
;
1390 return section
&& ((section
->section_mem_map
& flags
) == flags
);
1393 static inline int online_section_nr(unsigned long nr
)
1395 return online_section(__nr_to_section(nr
));
1398 #ifdef CONFIG_MEMORY_HOTPLUG
1399 void online_mem_sections(unsigned long start_pfn
, unsigned long end_pfn
);
1400 void offline_mem_sections(unsigned long start_pfn
, unsigned long end_pfn
);
1403 static inline struct mem_section
*__pfn_to_section(unsigned long pfn
)
1405 return __nr_to_section(pfn_to_section_nr(pfn
));
1408 extern unsigned long __highest_present_section_nr
;
1410 static inline int subsection_map_index(unsigned long pfn
)
1412 return (pfn
& ~(PAGE_SECTION_MASK
)) / PAGES_PER_SUBSECTION
;
1415 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1416 static inline int pfn_section_valid(struct mem_section
*ms
, unsigned long pfn
)
1418 int idx
= subsection_map_index(pfn
);
1420 return test_bit(idx
, ms
->usage
->subsection_map
);
1423 static inline int pfn_section_valid(struct mem_section
*ms
, unsigned long pfn
)
1429 #ifndef CONFIG_HAVE_ARCH_PFN_VALID
1430 static inline int pfn_valid(unsigned long pfn
)
1432 struct mem_section
*ms
;
1434 if (pfn_to_section_nr(pfn
) >= NR_MEM_SECTIONS
)
1436 ms
= __nr_to_section(pfn_to_section_nr(pfn
));
1437 if (!valid_section(ms
))
1440 * Traditionally early sections always returned pfn_valid() for
1441 * the entire section-sized span.
1443 return early_section(ms
) || pfn_section_valid(ms
, pfn
);
1447 static inline int pfn_in_present_section(unsigned long pfn
)
1449 if (pfn_to_section_nr(pfn
) >= NR_MEM_SECTIONS
)
1451 return present_section(__nr_to_section(pfn_to_section_nr(pfn
)));
1454 static inline unsigned long next_present_section_nr(unsigned long section_nr
)
1456 while (++section_nr
<= __highest_present_section_nr
) {
1457 if (present_section_nr(section_nr
))
1465 * These are _only_ used during initialisation, therefore they
1466 * can use __initdata ... They could have names to indicate
1470 #define pfn_to_nid(pfn) \
1472 unsigned long __pfn_to_nid_pfn = (pfn); \
1473 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \
1476 #define pfn_to_nid(pfn) (0)
1479 void sparse_init(void);
1481 #define sparse_init() do {} while (0)
1482 #define sparse_index_init(_sec, _nid) do {} while (0)
1483 #define pfn_in_present_section pfn_valid
1484 #define subsection_map_init(_pfn, _nr_pages) do {} while (0)
1485 #endif /* CONFIG_SPARSEMEM */
1488 * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we
1489 * need to check pfn validity within that MAX_ORDER_NR_PAGES block.
1490 * pfn_valid_within() should be used in this case; we optimise this away
1491 * when we have no holes within a MAX_ORDER_NR_PAGES block.
1493 #ifdef CONFIG_HOLES_IN_ZONE
1494 #define pfn_valid_within(pfn) pfn_valid(pfn)
1496 #define pfn_valid_within(pfn) (1)
1499 #endif /* !__GENERATING_BOUNDS.H */
1500 #endif /* !__ASSEMBLY__ */
1501 #endif /* _LINUX_MMZONE_H */