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>
23 #include <linux/local_lock.h>
26 /* Free memory management - zoned buddy allocator. */
27 #ifndef CONFIG_FORCE_MAX_ZONEORDER
30 #define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER
32 #define MAX_ORDER_NR_PAGES (1 << (MAX_ORDER - 1))
35 * PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed
36 * costly to service. That is between allocation orders which should
37 * coalesce naturally under reasonable reclaim pressure and those which
40 #define PAGE_ALLOC_COSTLY_ORDER 3
46 MIGRATE_PCPTYPES, /* the number of types on the pcp lists */
47 MIGRATE_HIGHATOMIC = MIGRATE_PCPTYPES,
50 * MIGRATE_CMA migration type is designed to mimic the way
51 * ZONE_MOVABLE works. Only movable pages can be allocated
52 * from MIGRATE_CMA pageblocks and page allocator never
53 * implicitly change migration type of MIGRATE_CMA pageblock.
55 * The way to use it is to change migratetype of a range of
56 * pageblocks to MIGRATE_CMA which can be done by
57 * __free_pageblock_cma() function. What is important though
58 * is that a range of pageblocks must be aligned to
59 * MAX_ORDER_NR_PAGES should biggest page be bigger than
64 #ifdef CONFIG_MEMORY_ISOLATION
65 MIGRATE_ISOLATE, /* can't allocate from here */
70 /* In mm/page_alloc.c; keep in sync also with show_migration_types() there */
71 extern const char * const migratetype_names[MIGRATE_TYPES];
74 # define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA)
75 # define is_migrate_cma_page(_page) (get_pageblock_migratetype(_page) == MIGRATE_CMA)
77 # define is_migrate_cma(migratetype) false
78 # define is_migrate_cma_page(_page) false
81 static inline bool is_migrate_movable(int mt)
83 return is_migrate_cma(mt) || mt == MIGRATE_MOVABLE;
86 #define for_each_migratetype_order(order, type) \
87 for (order = 0; order < MAX_ORDER; order++) \
88 for (type = 0; type < MIGRATE_TYPES; type++)
90 extern int page_group_by_mobility_disabled;
92 #define MIGRATETYPE_MASK ((1UL << PB_migratetype_bits) - 1)
94 #define get_pageblock_migratetype(page) \
95 get_pfnblock_flags_mask(page, page_to_pfn(page), MIGRATETYPE_MASK)
98 struct list_head free_list[MIGRATE_TYPES];
99 unsigned long nr_free;
102 static inline struct page *get_page_from_free_area(struct free_area *area,
105 return list_first_entry_or_null(&area->free_list[migratetype],
109 static inline bool free_area_empty(struct free_area *area, int migratetype)
111 return list_empty(&area->free_list[migratetype]);
117 * Add a wild amount of padding here to ensure datas fall into separate
118 * cachelines. There are very few zone structures in the machine, so space
119 * consumption is not a concern here.
121 #if defined(CONFIG_SMP)
122 struct zone_padding {
124 } ____cacheline_internodealigned_in_smp;
125 #define ZONE_PADDING(name) struct zone_padding name;
127 #define ZONE_PADDING(name)
131 enum numa_stat_item {
132 NUMA_HIT, /* allocated in intended node */
133 NUMA_MISS, /* allocated in non intended node */
134 NUMA_FOREIGN, /* was intended here, hit elsewhere */
135 NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */
136 NUMA_LOCAL, /* allocation from local node */
137 NUMA_OTHER, /* allocation from other node */
138 NR_VM_NUMA_EVENT_ITEMS
141 #define NR_VM_NUMA_EVENT_ITEMS 0
144 enum zone_stat_item {
145 /* First 128 byte cacheline (assuming 64 bit words) */
147 NR_ZONE_LRU_BASE, /* Used only for compaction and reclaim retry */
148 NR_ZONE_INACTIVE_ANON = NR_ZONE_LRU_BASE,
150 NR_ZONE_INACTIVE_FILE,
153 NR_ZONE_WRITE_PENDING, /* Count of dirty, writeback and unstable pages */
154 NR_MLOCK, /* mlock()ed pages found and moved off LRU */
155 /* Second 128 byte cacheline */
157 #if IS_ENABLED(CONFIG_ZSMALLOC)
158 NR_ZSPAGES, /* allocated in zsmalloc */
161 NR_VM_ZONE_STAT_ITEMS };
163 enum node_stat_item {
165 NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */
166 NR_ACTIVE_ANON, /* " " " " " */
167 NR_INACTIVE_FILE, /* " " " " " */
168 NR_ACTIVE_FILE, /* " " " " " */
169 NR_UNEVICTABLE, /* " " " " " */
170 NR_SLAB_RECLAIMABLE_B,
171 NR_SLAB_UNRECLAIMABLE_B,
172 NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */
173 NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */
175 WORKINGSET_REFAULT_BASE,
176 WORKINGSET_REFAULT_ANON = WORKINGSET_REFAULT_BASE,
177 WORKINGSET_REFAULT_FILE,
178 WORKINGSET_ACTIVATE_BASE,
179 WORKINGSET_ACTIVATE_ANON = WORKINGSET_ACTIVATE_BASE,
180 WORKINGSET_ACTIVATE_FILE,
181 WORKINGSET_RESTORE_BASE,
182 WORKINGSET_RESTORE_ANON = WORKINGSET_RESTORE_BASE,
183 WORKINGSET_RESTORE_FILE,
184 WORKINGSET_NODERECLAIM,
185 NR_ANON_MAPPED, /* Mapped anonymous pages */
186 NR_FILE_MAPPED, /* pagecache pages mapped into pagetables.
187 only modified from process context */
191 NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */
192 NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */
199 NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */
200 NR_DIRTIED, /* page dirtyings since bootup */
201 NR_WRITTEN, /* page writings since bootup */
202 NR_KERNEL_MISC_RECLAIMABLE, /* reclaimable non-slab kernel pages */
203 NR_FOLL_PIN_ACQUIRED, /* via: pin_user_page(), gup flag: FOLL_PIN */
204 NR_FOLL_PIN_RELEASED, /* pages returned via unpin_user_page() */
205 NR_KERNEL_STACK_KB, /* measured in KiB */
206 #if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
207 NR_KERNEL_SCS_KB, /* measured in KiB */
209 NR_PAGETABLE, /* used for pagetables */
213 NR_VM_NODE_STAT_ITEMS
217 * Returns true if the item should be printed in THPs (/proc/vmstat
218 * currently prints number of anon, file and shmem THPs. But the item
219 * is charged in pages).
221 static __always_inline bool vmstat_item_print_in_thp(enum node_stat_item item)
223 if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))
226 return item == NR_ANON_THPS ||
227 item == NR_FILE_THPS ||
228 item == NR_SHMEM_THPS ||
229 item == NR_SHMEM_PMDMAPPED ||
230 item == NR_FILE_PMDMAPPED;
234 * Returns true if the value is measured in bytes (most vmstat values are
235 * measured in pages). This defines the API part, the internal representation
236 * might be different.
238 static __always_inline bool vmstat_item_in_bytes(int idx)
241 * Global and per-node slab counters track slab pages.
242 * It's expected that changes are multiples of PAGE_SIZE.
243 * Internally values are stored in pages.
245 * Per-memcg and per-lruvec counters track memory, consumed
246 * by individual slab objects. These counters are actually
249 return (idx == NR_SLAB_RECLAIMABLE_B ||
250 idx == NR_SLAB_UNRECLAIMABLE_B);
254 * We do arithmetic on the LRU lists in various places in the code,
255 * so it is important to keep the active lists LRU_ACTIVE higher in
256 * the array than the corresponding inactive lists, and to keep
257 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists.
259 * This has to be kept in sync with the statistics in zone_stat_item
260 * above and the descriptions in vmstat_text in mm/vmstat.c
267 LRU_INACTIVE_ANON = LRU_BASE,
268 LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE,
269 LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE,
270 LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE,
275 #define for_each_lru(lru) for (lru = 0; lru < NR_LRU_LISTS; lru++)
277 #define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_ACTIVE_FILE; lru++)
279 static inline bool is_file_lru(enum lru_list lru)
281 return (lru == LRU_INACTIVE_FILE || lru == LRU_ACTIVE_FILE);
284 static inline bool is_active_lru(enum lru_list lru)
286 return (lru == LRU_ACTIVE_ANON || lru == LRU_ACTIVE_FILE);
289 #define ANON_AND_FILE 2
292 LRUVEC_CONGESTED, /* lruvec has many dirty pages
293 * backed by a congested BDI
298 struct list_head lists[NR_LRU_LISTS];
299 /* per lruvec lru_lock for memcg */
302 * These track the cost of reclaiming one LRU - file or anon -
303 * over the other. As the observed cost of reclaiming one LRU
304 * increases, the reclaim scan balance tips toward the other.
306 unsigned long anon_cost;
307 unsigned long file_cost;
308 /* Non-resident age, driven by LRU movement */
309 atomic_long_t nonresident_age;
310 /* Refaults at the time of last reclaim cycle */
311 unsigned long refaults[ANON_AND_FILE];
312 /* Various lruvec state flags (enum lruvec_flags) */
315 struct pglist_data *pgdat;
319 /* Isolate unmapped pages */
320 #define ISOLATE_UNMAPPED ((__force isolate_mode_t)0x2)
321 /* Isolate for asynchronous migration */
322 #define ISOLATE_ASYNC_MIGRATE ((__force isolate_mode_t)0x4)
323 /* Isolate unevictable pages */
324 #define ISOLATE_UNEVICTABLE ((__force isolate_mode_t)0x8)
326 /* LRU Isolation modes. */
327 typedef unsigned __bitwise isolate_mode_t;
329 enum zone_watermarks {
336 #define min_wmark_pages(z) (z->_watermark[WMARK_MIN] + z->watermark_boost)
337 #define low_wmark_pages(z) (z->_watermark[WMARK_LOW] + z->watermark_boost)
338 #define high_wmark_pages(z) (z->_watermark[WMARK_HIGH] + z->watermark_boost)
339 #define wmark_pages(z, i) (z->_watermark[i] + z->watermark_boost)
341 /* Fields and list protected by pagesets local_lock in page_alloc.c */
342 struct per_cpu_pages {
343 int count; /* number of pages in the list */
344 int high; /* high watermark, emptying needed */
345 int batch; /* chunk size for buddy add/remove */
346 short free_factor; /* batch scaling factor during free */
348 short expire; /* When 0, remote pagesets are drained */
351 /* Lists of pages, one per migrate type stored on the pcp-lists */
352 struct list_head lists[MIGRATE_PCPTYPES];
355 struct per_cpu_zonestat {
357 s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS];
362 * Low priority inaccurate counters that are only folded
363 * on demand. Use a large type to avoid the overhead of
364 * folding during refresh_cpu_vm_stats.
366 unsigned long vm_numa_event[NR_VM_NUMA_EVENT_ITEMS];
370 struct per_cpu_nodestat {
372 s8 vm_node_stat_diff[NR_VM_NODE_STAT_ITEMS];
375 #endif /* !__GENERATING_BOUNDS.H */
379 * ZONE_DMA and ZONE_DMA32 are used when there are peripherals not able
380 * to DMA to all of the addressable memory (ZONE_NORMAL).
381 * On architectures where this area covers the whole 32 bit address
382 * space ZONE_DMA32 is used. ZONE_DMA is left for the ones with smaller
383 * DMA addressing constraints. This distinction is important as a 32bit
384 * DMA mask is assumed when ZONE_DMA32 is defined. Some 64-bit
385 * platforms may need both zones as they support peripherals with
386 * different DMA addressing limitations.
388 #ifdef CONFIG_ZONE_DMA
391 #ifdef CONFIG_ZONE_DMA32
395 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be
396 * performed on pages in ZONE_NORMAL if the DMA devices support
397 * transfers to all addressable memory.
400 #ifdef CONFIG_HIGHMEM
402 * A memory area that is only addressable by the kernel through
403 * mapping portions into its own address space. This is for example
404 * used by i386 to allow the kernel to address the memory beyond
405 * 900MB. The kernel will set up special mappings (page
406 * table entries on i386) for each page that the kernel needs to
412 * ZONE_MOVABLE is similar to ZONE_NORMAL, except that it contains
413 * movable pages with few exceptional cases described below. Main use
414 * cases for ZONE_MOVABLE are to make memory offlining/unplug more
415 * likely to succeed, and to locally limit unmovable allocations - e.g.,
416 * to increase the number of THP/huge pages. Notable special cases are:
418 * 1. Pinned pages: (long-term) pinning of movable pages might
419 * essentially turn such pages unmovable. Therefore, we do not allow
420 * pinning long-term pages in ZONE_MOVABLE. When pages are pinned and
421 * faulted, they come from the right zone right away. However, it is
422 * still possible that address space already has pages in
423 * ZONE_MOVABLE at the time when pages are pinned (i.e. user has
424 * touches that memory before pinning). In such case we migrate them
425 * to a different zone. When migration fails - pinning fails.
426 * 2. memblock allocations: kernelcore/movablecore setups might create
427 * situations where ZONE_MOVABLE contains unmovable allocations
428 * after boot. Memory offlining and allocations fail early.
429 * 3. Memory holes: kernelcore/movablecore setups might create very rare
430 * situations where ZONE_MOVABLE contains memory holes after boot,
431 * for example, if we have sections that are only partially
432 * populated. Memory offlining and allocations fail early.
433 * 4. PG_hwpoison pages: while poisoned pages can be skipped during
434 * memory offlining, such pages cannot be allocated.
435 * 5. Unmovable PG_offline pages: in paravirtualized environments,
436 * hotplugged memory blocks might only partially be managed by the
437 * buddy (e.g., via XEN-balloon, Hyper-V balloon, virtio-mem). The
438 * parts not manged by the buddy are unmovable PG_offline pages. In
439 * some cases (virtio-mem), such pages can be skipped during
440 * memory offlining, however, cannot be moved/allocated. These
441 * techniques might use alloc_contig_range() to hide previously
442 * exposed pages from the buddy again (e.g., to implement some sort
443 * of memory unplug in virtio-mem).
444 * 6. ZERO_PAGE(0), kernelcore/movablecore setups might create
445 * situations where ZERO_PAGE(0) which is allocated differently
446 * on different platforms may end up in a movable zone. ZERO_PAGE(0)
447 * cannot be migrated.
448 * 7. Memory-hotplug: when using memmap_on_memory and onlining the
449 * memory to the MOVABLE zone, the vmemmap pages are also placed in
450 * such zone. Such pages cannot be really moved around as they are
451 * self-stored in the range, but they are treated as movable when
452 * the range they describe is about to be offlined.
454 * In general, no unmovable allocations that degrade memory offlining
455 * should end up in ZONE_MOVABLE. Allocators (like alloc_contig_range())
456 * have to expect that migrating pages in ZONE_MOVABLE can fail (even
457 * if has_unmovable_pages() states that there are no unmovable pages,
458 * there can be false negatives).
461 #ifdef CONFIG_ZONE_DEVICE
468 #ifndef __GENERATING_BOUNDS_H
470 #define ASYNC_AND_SYNC 2
473 /* Read-mostly fields */
475 /* zone watermarks, access with *_wmark_pages(zone) macros */
476 unsigned long _watermark[NR_WMARK];
477 unsigned long watermark_boost;
479 unsigned long nr_reserved_highatomic;
482 * We don't know if the memory that we're going to allocate will be
483 * freeable or/and it will be released eventually, so to avoid totally
484 * wasting several GB of ram we must reserve some of the lower zone
485 * memory (otherwise we risk to run OOM on the lower zones despite
486 * there being tons of freeable ram on the higher zones). This array is
487 * recalculated at runtime if the sysctl_lowmem_reserve_ratio sysctl
490 long lowmem_reserve[MAX_NR_ZONES];
495 struct pglist_data *zone_pgdat;
496 struct per_cpu_pages __percpu *per_cpu_pageset;
497 struct per_cpu_zonestat __percpu *per_cpu_zonestats;
499 * the high and batch values are copied to individual pagesets for
505 #ifndef CONFIG_SPARSEMEM
507 * Flags for a pageblock_nr_pages block. See pageblock-flags.h.
508 * In SPARSEMEM, this map is stored in struct mem_section
510 unsigned long *pageblock_flags;
511 #endif /* CONFIG_SPARSEMEM */
513 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
514 unsigned long zone_start_pfn;
517 * spanned_pages is the total pages spanned by the zone, including
518 * holes, which is calculated as:
519 * spanned_pages = zone_end_pfn - zone_start_pfn;
521 * present_pages is physical pages existing within the zone, which
523 * present_pages = spanned_pages - absent_pages(pages in holes);
525 * managed_pages is present pages managed by the buddy system, which
526 * is calculated as (reserved_pages includes pages allocated by the
527 * bootmem allocator):
528 * managed_pages = present_pages - reserved_pages;
530 * cma pages is present pages that are assigned for CMA use
533 * So present_pages may be used by memory hotplug or memory power
534 * management logic to figure out unmanaged pages by checking
535 * (present_pages - managed_pages). And managed_pages should be used
536 * by page allocator and vm scanner to calculate all kinds of watermarks
541 * zone_start_pfn and spanned_pages are protected by span_seqlock.
542 * It is a seqlock because it has to be read outside of zone->lock,
543 * and it is done in the main allocator path. But, it is written
544 * quite infrequently.
546 * The span_seq lock is declared along with zone->lock because it is
547 * frequently read in proximity to zone->lock. It's good to
548 * give them a chance of being in the same cacheline.
550 * Write access to present_pages at runtime should be protected by
551 * mem_hotplug_begin/end(). Any reader who can't tolerant drift of
552 * present_pages should get_online_mems() to get a stable value.
554 atomic_long_t managed_pages;
555 unsigned long spanned_pages;
556 unsigned long present_pages;
558 unsigned long cma_pages;
563 #ifdef CONFIG_MEMORY_ISOLATION
565 * Number of isolated pageblock. It is used to solve incorrect
566 * freepage counting problem due to racy retrieving migratetype
567 * of pageblock. Protected by zone->lock.
569 unsigned long nr_isolate_pageblock;
572 #ifdef CONFIG_MEMORY_HOTPLUG
573 /* see spanned/present_pages for more description */
574 seqlock_t span_seqlock;
579 /* Write-intensive fields used from the page allocator */
582 /* free areas of different sizes */
583 struct free_area free_area[MAX_ORDER];
585 /* zone flags, see below */
588 /* Primarily protects free_area */
591 /* Write-intensive fields used by compaction and vmstats. */
595 * When free pages are below this point, additional steps are taken
596 * when reading the number of free pages to avoid per-cpu counter
597 * drift allowing watermarks to be breached
599 unsigned long percpu_drift_mark;
601 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
602 /* pfn where compaction free scanner should start */
603 unsigned long compact_cached_free_pfn;
604 /* pfn where compaction migration scanner should start */
605 unsigned long compact_cached_migrate_pfn[ASYNC_AND_SYNC];
606 unsigned long compact_init_migrate_pfn;
607 unsigned long compact_init_free_pfn;
610 #ifdef CONFIG_COMPACTION
612 * On compaction failure, 1<<compact_defer_shift compactions
613 * are skipped before trying again. The number attempted since
614 * last failure is tracked with compact_considered.
615 * compact_order_failed is the minimum compaction failed order.
617 unsigned int compact_considered;
618 unsigned int compact_defer_shift;
619 int compact_order_failed;
622 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
623 /* Set to true when the PG_migrate_skip bits should be cleared */
624 bool compact_blockskip_flush;
630 /* Zone statistics */
631 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
632 atomic_long_t vm_numa_event[NR_VM_NUMA_EVENT_ITEMS];
633 } ____cacheline_internodealigned_in_smp;
636 PGDAT_DIRTY, /* reclaim scanning has recently found
637 * many dirty file pages at the tail
640 PGDAT_WRITEBACK, /* reclaim scanning has recently found
641 * many pages under writeback
643 PGDAT_RECLAIM_LOCKED, /* prevents concurrent reclaim */
647 ZONE_BOOSTED_WATERMARK, /* zone recently boosted watermarks.
648 * Cleared when kswapd is woken.
652 static inline unsigned long zone_managed_pages(struct zone *zone)
654 return (unsigned long)atomic_long_read(&zone->managed_pages);
657 static inline unsigned long zone_cma_pages(struct zone *zone)
660 return zone->cma_pages;
666 static inline unsigned long zone_end_pfn(const struct zone *zone)
668 return zone->zone_start_pfn + zone->spanned_pages;
671 static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn)
673 return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone);
676 static inline bool zone_is_initialized(struct zone *zone)
678 return zone->initialized;
681 static inline bool zone_is_empty(struct zone *zone)
683 return zone->spanned_pages == 0;
687 * Return true if [start_pfn, start_pfn + nr_pages) range has a non-empty
688 * intersection with the given zone
690 static inline bool zone_intersects(struct zone *zone,
691 unsigned long start_pfn, unsigned long nr_pages)
693 if (zone_is_empty(zone))
695 if (start_pfn >= zone_end_pfn(zone) ||
696 start_pfn + nr_pages <= zone->zone_start_pfn)
703 * The "priority" of VM scanning is how much of the queues we will scan in one
704 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
705 * queues ("queue_length >> 12") during an aging round.
707 #define DEF_PRIORITY 12
709 /* Maximum number of zones on a zonelist */
710 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
713 ZONELIST_FALLBACK, /* zonelist with fallback */
716 * The NUMA zonelists are doubled because we need zonelists that
717 * restrict the allocations to a single node for __GFP_THISNODE.
719 ZONELIST_NOFALLBACK, /* zonelist without fallback (__GFP_THISNODE) */
725 * This struct contains information about a zone in a zonelist. It is stored
726 * here to avoid dereferences into large structures and lookups of tables
729 struct zone *zone; /* Pointer to actual zone */
730 int zone_idx; /* zone_idx(zoneref->zone) */
734 * One allocation request operates on a zonelist. A zonelist
735 * is a list of zones, the first one is the 'goal' of the
736 * allocation, the other zones are fallback zones, in decreasing
739 * To speed the reading of the zonelist, the zonerefs contain the zone index
740 * of the entry being read. Helper functions to access information given
741 * a struct zoneref are
743 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs
744 * zonelist_zone_idx() - Return the index of the zone for an entry
745 * zonelist_node_idx() - Return the index of the node for an entry
748 struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1];
751 #ifndef CONFIG_DISCONTIGMEM
752 /* The array of struct pages - for discontigmem use pgdat->lmem_map */
753 extern struct page *mem_map;
756 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
757 struct deferred_split {
758 spinlock_t split_queue_lock;
759 struct list_head split_queue;
760 unsigned long split_queue_len;
765 * On NUMA machines, each NUMA node would have a pg_data_t to describe
766 * it's memory layout. On UMA machines there is a single pglist_data which
767 * describes the whole memory.
769 * Memory statistics and page replacement data structures are maintained on a
772 typedef struct pglist_data {
774 * node_zones contains just the zones for THIS node. Not all of the
775 * zones may be populated, but it is the full list. It is referenced by
776 * this node's node_zonelists as well as other node's node_zonelists.
778 struct zone node_zones[MAX_NR_ZONES];
781 * node_zonelists contains references to all zones in all nodes.
782 * Generally the first zones will be references to this node's
785 struct zonelist node_zonelists[MAX_ZONELISTS];
787 int nr_zones; /* number of populated zones in this node */
788 #ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */
789 struct page *node_mem_map;
790 #ifdef CONFIG_PAGE_EXTENSION
791 struct page_ext *node_page_ext;
794 #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT)
796 * Must be held any time you expect node_start_pfn,
797 * node_present_pages, node_spanned_pages or nr_zones to stay constant.
798 * Also synchronizes pgdat->first_deferred_pfn during deferred page
801 * pgdat_resize_lock() and pgdat_resize_unlock() are provided to
802 * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG
803 * or CONFIG_DEFERRED_STRUCT_PAGE_INIT.
805 * Nests above zone->lock and zone->span_seqlock
807 spinlock_t node_size_lock;
809 unsigned long node_start_pfn;
810 unsigned long node_present_pages; /* total number of physical pages */
811 unsigned long node_spanned_pages; /* total size of physical page
812 range, including holes */
814 wait_queue_head_t kswapd_wait;
815 wait_queue_head_t pfmemalloc_wait;
816 struct task_struct *kswapd; /* Protected by
817 mem_hotplug_begin/end() */
819 enum zone_type kswapd_highest_zoneidx;
821 int kswapd_failures; /* Number of 'reclaimed == 0' runs */
823 #ifdef CONFIG_COMPACTION
824 int kcompactd_max_order;
825 enum zone_type kcompactd_highest_zoneidx;
826 wait_queue_head_t kcompactd_wait;
827 struct task_struct *kcompactd;
830 * This is a per-node reserve of pages that are not available
831 * to userspace allocations.
833 unsigned long totalreserve_pages;
837 * node reclaim becomes active if more unmapped pages exist.
839 unsigned long min_unmapped_pages;
840 unsigned long min_slab_pages;
841 #endif /* CONFIG_NUMA */
843 /* Write-intensive fields used by page reclaim */
846 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
848 * If memory initialisation on large machines is deferred then this
849 * is the first PFN that needs to be initialised.
851 unsigned long first_deferred_pfn;
852 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
854 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
855 struct deferred_split deferred_split_queue;
858 /* Fields commonly accessed by the page reclaim scanner */
861 * NOTE: THIS IS UNUSED IF MEMCG IS ENABLED.
863 * Use mem_cgroup_lruvec() to look up lruvecs.
865 struct lruvec __lruvec;
871 /* Per-node vmstats */
872 struct per_cpu_nodestat __percpu *per_cpu_nodestats;
873 atomic_long_t vm_stat[NR_VM_NODE_STAT_ITEMS];
876 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
877 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
878 #ifdef CONFIG_FLAT_NODE_MEM_MAP
879 #define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr))
881 #define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr))
883 #define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr))
885 #define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn)
886 #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid))
888 static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat)
890 return pgdat->node_start_pfn + pgdat->node_spanned_pages;
893 static inline bool pgdat_is_empty(pg_data_t *pgdat)
895 return !pgdat->node_start_pfn && !pgdat->node_spanned_pages;
898 #include <linux/memory_hotplug.h>
900 void build_all_zonelists(pg_data_t *pgdat);
901 void wakeup_kswapd(struct zone *zone, gfp_t gfp_mask, int order,
902 enum zone_type highest_zoneidx);
903 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
904 int highest_zoneidx, unsigned int alloc_flags,
906 bool zone_watermark_ok(struct zone *z, unsigned int order,
907 unsigned long mark, int highest_zoneidx,
908 unsigned int alloc_flags);
909 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
910 unsigned long mark, int highest_zoneidx);
912 * Memory initialization context, use to differentiate memory added by
913 * the platform statically or via memory hotplug interface.
915 enum meminit_context {
920 extern void init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
923 extern void lruvec_init(struct lruvec *lruvec);
925 static inline struct pglist_data *lruvec_pgdat(struct lruvec *lruvec)
928 return lruvec->pgdat;
930 return container_of(lruvec, struct pglist_data, __lruvec);
934 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
935 int local_memory_node(int node_id);
937 static inline int local_memory_node(int node_id) { return node_id; };
941 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
943 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones)
945 #ifdef CONFIG_ZONE_DEVICE
946 static inline bool zone_is_zone_device(struct zone *zone)
948 return zone_idx(zone) == ZONE_DEVICE;
951 static inline bool zone_is_zone_device(struct zone *zone)
958 * Returns true if a zone has pages managed by the buddy allocator.
959 * All the reclaim decisions have to use this function rather than
960 * populated_zone(). If the whole zone is reserved then we can easily
961 * end up with populated_zone() && !managed_zone().
963 static inline bool managed_zone(struct zone *zone)
965 return zone_managed_pages(zone);
968 /* Returns true if a zone has memory */
969 static inline bool populated_zone(struct zone *zone)
971 return zone->present_pages;
975 static inline int zone_to_nid(struct zone *zone)
980 static inline void zone_set_nid(struct zone *zone, int nid)
985 static inline int zone_to_nid(struct zone *zone)
990 static inline void zone_set_nid(struct zone *zone, int nid) {}
993 extern int movable_zone;
995 static inline int is_highmem_idx(enum zone_type idx)
997 #ifdef CONFIG_HIGHMEM
998 return (idx == ZONE_HIGHMEM ||
999 (idx == ZONE_MOVABLE && movable_zone == ZONE_HIGHMEM));
1006 * is_highmem - helper function to quickly check if a struct zone is a
1007 * highmem zone or not. This is an attempt to keep references
1008 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
1009 * @zone: pointer to struct zone variable
1010 * Return: 1 for a highmem zone, 0 otherwise
1012 static inline int is_highmem(struct zone *zone)
1014 #ifdef CONFIG_HIGHMEM
1015 return is_highmem_idx(zone_idx(zone));
1021 /* These two functions are used to setup the per zone pages min values */
1024 int min_free_kbytes_sysctl_handler(struct ctl_table *, int, void *, size_t *,
1026 int watermark_scale_factor_sysctl_handler(struct ctl_table *, int, void *,
1027 size_t *, loff_t *);
1028 extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES];
1029 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, void *,
1030 size_t *, loff_t *);
1031 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int,
1032 void *, size_t *, loff_t *);
1033 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int,
1034 void *, size_t *, loff_t *);
1035 int numa_zonelist_order_handler(struct ctl_table *, int,
1036 void *, size_t *, loff_t *);
1037 extern char numa_zonelist_order[];
1038 #define NUMA_ZONELIST_ORDER_LEN 16
1040 #ifndef CONFIG_NEED_MULTIPLE_NODES
1042 extern struct pglist_data contig_page_data;
1043 #define NODE_DATA(nid) (&contig_page_data)
1044 #define NODE_MEM_MAP(nid) mem_map
1046 #else /* CONFIG_NEED_MULTIPLE_NODES */
1048 #include <asm/mmzone.h>
1050 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
1052 extern struct pglist_data *first_online_pgdat(void);
1053 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
1054 extern struct zone *next_zone(struct zone *zone);
1057 * for_each_online_pgdat - helper macro to iterate over all online nodes
1058 * @pgdat: pointer to a pg_data_t variable
1060 #define for_each_online_pgdat(pgdat) \
1061 for (pgdat = first_online_pgdat(); \
1063 pgdat = next_online_pgdat(pgdat))
1065 * for_each_zone - helper macro to iterate over all memory zones
1066 * @zone: pointer to struct zone variable
1068 * The user only needs to declare the zone variable, for_each_zone
1071 #define for_each_zone(zone) \
1072 for (zone = (first_online_pgdat())->node_zones; \
1074 zone = next_zone(zone))
1076 #define for_each_populated_zone(zone) \
1077 for (zone = (first_online_pgdat())->node_zones; \
1079 zone = next_zone(zone)) \
1080 if (!populated_zone(zone)) \
1081 ; /* do nothing */ \
1084 static inline struct zone *zonelist_zone(struct zoneref *zoneref)
1086 return zoneref->zone;
1089 static inline int zonelist_zone_idx(struct zoneref *zoneref)
1091 return zoneref->zone_idx;
1094 static inline int zonelist_node_idx(struct zoneref *zoneref)
1096 return zone_to_nid(zoneref->zone);
1099 struct zoneref *__next_zones_zonelist(struct zoneref *z,
1100 enum zone_type highest_zoneidx,
1104 * 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
1105 * @z: The cursor used as a starting point for the search
1106 * @highest_zoneidx: The zone index of the highest zone to return
1107 * @nodes: An optional nodemask to filter the zonelist with
1109 * This function returns the next zone at or below a given zone index that is
1110 * within the allowed nodemask using a cursor as the starting point for the
1111 * search. The zoneref returned is a cursor that represents the current zone
1112 * being examined. It should be advanced by one before calling
1113 * next_zones_zonelist again.
1115 * Return: the next zone at or below highest_zoneidx within the allowed
1116 * nodemask using a cursor within a zonelist as a starting point
1118 static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z,
1119 enum zone_type highest_zoneidx,
1122 if (likely(!nodes && zonelist_zone_idx(z) <= highest_zoneidx))
1124 return __next_zones_zonelist(z, highest_zoneidx, nodes);
1128 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
1129 * @zonelist: The zonelist to search for a suitable zone
1130 * @highest_zoneidx: The zone index of the highest zone to return
1131 * @nodes: An optional nodemask to filter the zonelist with
1133 * This function returns the first zone at or below a given zone index that is
1134 * within the allowed nodemask. The zoneref returned is a cursor that can be
1135 * used to iterate the zonelist with next_zones_zonelist by advancing it by
1136 * one before calling.
1138 * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is
1139 * never NULL). This may happen either genuinely, or due to concurrent nodemask
1140 * update due to cpuset modification.
1142 * Return: Zoneref pointer for the first suitable zone found
1144 static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
1145 enum zone_type highest_zoneidx,
1148 return next_zones_zonelist(zonelist->_zonerefs,
1149 highest_zoneidx, nodes);
1153 * 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
1154 * @zone: The current zone in the iterator
1155 * @z: The current pointer within zonelist->_zonerefs being iterated
1156 * @zlist: The zonelist being iterated
1157 * @highidx: The zone index of the highest zone to return
1158 * @nodemask: Nodemask allowed by the allocator
1160 * This iterator iterates though all zones at or below a given zone index and
1161 * within a given nodemask
1163 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
1164 for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z); \
1166 z = next_zones_zonelist(++z, highidx, nodemask), \
1167 zone = zonelist_zone(z))
1169 #define for_next_zone_zonelist_nodemask(zone, z, highidx, nodemask) \
1170 for (zone = z->zone; \
1172 z = next_zones_zonelist(++z, highidx, nodemask), \
1173 zone = zonelist_zone(z))
1177 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
1178 * @zone: The current zone in the iterator
1179 * @z: The current pointer within zonelist->zones being iterated
1180 * @zlist: The zonelist being iterated
1181 * @highidx: The zone index of the highest zone to return
1183 * This iterator iterates though all zones at or below a given zone index.
1185 #define for_each_zone_zonelist(zone, z, zlist, highidx) \
1186 for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL)
1188 #ifdef CONFIG_SPARSEMEM
1189 #include <asm/sparsemem.h>
1192 #ifdef CONFIG_FLATMEM
1193 #define pfn_to_nid(pfn) (0)
1196 #ifdef CONFIG_SPARSEMEM
1199 * SECTION_SHIFT #bits space required to store a section #
1201 * PA_SECTION_SHIFT physical address to/from section number
1202 * PFN_SECTION_SHIFT pfn to/from section number
1204 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS)
1205 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
1207 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT)
1209 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT)
1210 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1))
1212 #define SECTION_BLOCKFLAGS_BITS \
1213 ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS)
1215 #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
1216 #error Allocator MAX_ORDER exceeds SECTION_SIZE
1219 static inline unsigned long pfn_to_section_nr(unsigned long pfn)
1221 return pfn >> PFN_SECTION_SHIFT;
1223 static inline unsigned long section_nr_to_pfn(unsigned long sec)
1225 return sec << PFN_SECTION_SHIFT;
1228 #define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK)
1229 #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK)
1231 #define SUBSECTION_SHIFT 21
1232 #define SUBSECTION_SIZE (1UL << SUBSECTION_SHIFT)
1234 #define PFN_SUBSECTION_SHIFT (SUBSECTION_SHIFT - PAGE_SHIFT)
1235 #define PAGES_PER_SUBSECTION (1UL << PFN_SUBSECTION_SHIFT)
1236 #define PAGE_SUBSECTION_MASK (~(PAGES_PER_SUBSECTION-1))
1238 #if SUBSECTION_SHIFT > SECTION_SIZE_BITS
1239 #error Subsection size exceeds section size
1241 #define SUBSECTIONS_PER_SECTION (1UL << (SECTION_SIZE_BITS - SUBSECTION_SHIFT))
1244 #define SUBSECTION_ALIGN_UP(pfn) ALIGN((pfn), PAGES_PER_SUBSECTION)
1245 #define SUBSECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SUBSECTION_MASK)
1247 struct mem_section_usage {
1248 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1249 DECLARE_BITMAP(subsection_map, SUBSECTIONS_PER_SECTION);
1251 /* See declaration of similar field in struct zone */
1252 unsigned long pageblock_flags[0];
1255 void subsection_map_init(unsigned long pfn, unsigned long nr_pages);
1259 struct mem_section {
1261 * This is, logically, a pointer to an array of struct
1262 * pages. However, it is stored with some other magic.
1263 * (see sparse.c::sparse_init_one_section())
1265 * Additionally during early boot we encode node id of
1266 * the location of the section here to guide allocation.
1267 * (see sparse.c::memory_present())
1269 * Making it a UL at least makes someone do a cast
1270 * before using it wrong.
1272 unsigned long section_mem_map;
1274 struct mem_section_usage *usage;
1275 #ifdef CONFIG_PAGE_EXTENSION
1277 * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use
1278 * section. (see page_ext.h about this.)
1280 struct page_ext *page_ext;
1284 * WARNING: mem_section must be a power-of-2 in size for the
1285 * calculation and use of SECTION_ROOT_MASK to make sense.
1289 #ifdef CONFIG_SPARSEMEM_EXTREME
1290 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section))
1292 #define SECTIONS_PER_ROOT 1
1295 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
1296 #define NR_SECTION_ROOTS DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT)
1297 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1)
1299 #ifdef CONFIG_SPARSEMEM_EXTREME
1300 extern struct mem_section **mem_section;
1302 extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
1305 static inline unsigned long *section_to_usemap(struct mem_section *ms)
1307 return ms->usage->pageblock_flags;
1310 static inline struct mem_section *__nr_to_section(unsigned long nr)
1312 #ifdef CONFIG_SPARSEMEM_EXTREME
1316 if (!mem_section[SECTION_NR_TO_ROOT(nr)])
1318 return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];
1320 extern unsigned long __section_nr(struct mem_section *ms);
1321 extern size_t mem_section_usage_size(void);
1324 * We use the lower bits of the mem_map pointer to store
1325 * a little bit of information. The pointer is calculated
1326 * as mem_map - section_nr_to_pfn(pnum). The result is
1327 * aligned to the minimum alignment of the two values:
1328 * 1. All mem_map arrays are page-aligned.
1329 * 2. section_nr_to_pfn() always clears PFN_SECTION_SHIFT
1330 * lowest bits. PFN_SECTION_SHIFT is arch-specific
1331 * (equal SECTION_SIZE_BITS - PAGE_SHIFT), and the
1332 * worst combination is powerpc with 256k pages,
1333 * which results in PFN_SECTION_SHIFT equal 6.
1334 * To sum it up, at least 6 bits are available.
1336 #define SECTION_MARKED_PRESENT (1UL<<0)
1337 #define SECTION_HAS_MEM_MAP (1UL<<1)
1338 #define SECTION_IS_ONLINE (1UL<<2)
1339 #define SECTION_IS_EARLY (1UL<<3)
1340 #define SECTION_TAINT_ZONE_DEVICE (1UL<<4)
1341 #define SECTION_MAP_LAST_BIT (1UL<<5)
1342 #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1))
1343 #define SECTION_NID_SHIFT 3
1345 static inline struct page *__section_mem_map_addr(struct mem_section *section)
1347 unsigned long map = section->section_mem_map;
1348 map &= SECTION_MAP_MASK;
1349 return (struct page *)map;
1352 static inline int present_section(struct mem_section *section)
1354 return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
1357 static inline int present_section_nr(unsigned long nr)
1359 return present_section(__nr_to_section(nr));
1362 static inline int valid_section(struct mem_section *section)
1364 return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
1367 static inline int early_section(struct mem_section *section)
1369 return (section && (section->section_mem_map & SECTION_IS_EARLY));
1372 static inline int valid_section_nr(unsigned long nr)
1374 return valid_section(__nr_to_section(nr));
1377 static inline int online_section(struct mem_section *section)
1379 return (section && (section->section_mem_map & SECTION_IS_ONLINE));
1382 static inline int online_device_section(struct mem_section *section)
1384 unsigned long flags = SECTION_IS_ONLINE | SECTION_TAINT_ZONE_DEVICE;
1386 return section && ((section->section_mem_map & flags) == flags);
1389 static inline int online_section_nr(unsigned long nr)
1391 return online_section(__nr_to_section(nr));
1394 #ifdef CONFIG_MEMORY_HOTPLUG
1395 void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn);
1396 void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn);
1399 static inline struct mem_section *__pfn_to_section(unsigned long pfn)
1401 return __nr_to_section(pfn_to_section_nr(pfn));
1404 extern unsigned long __highest_present_section_nr;
1406 static inline int subsection_map_index(unsigned long pfn)
1408 return (pfn & ~(PAGE_SECTION_MASK)) / PAGES_PER_SUBSECTION;
1411 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1412 static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
1414 int idx = subsection_map_index(pfn);
1416 return test_bit(idx, ms->usage->subsection_map);
1419 static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
1425 #ifndef CONFIG_HAVE_ARCH_PFN_VALID
1426 static inline int pfn_valid(unsigned long pfn)
1428 struct mem_section *ms;
1430 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
1432 ms = __nr_to_section(pfn_to_section_nr(pfn));
1433 if (!valid_section(ms))
1436 * Traditionally early sections always returned pfn_valid() for
1437 * the entire section-sized span.
1439 return early_section(ms) || pfn_section_valid(ms, pfn);
1443 static inline int pfn_in_present_section(unsigned long pfn)
1445 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
1447 return present_section(__nr_to_section(pfn_to_section_nr(pfn)));
1450 static inline unsigned long next_present_section_nr(unsigned long section_nr)
1452 while (++section_nr <= __highest_present_section_nr) {
1453 if (present_section_nr(section_nr))
1461 * These are _only_ used during initialisation, therefore they
1462 * can use __initdata ... They could have names to indicate
1466 #define pfn_to_nid(pfn) \
1468 unsigned long __pfn_to_nid_pfn = (pfn); \
1469 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \
1472 #define pfn_to_nid(pfn) (0)
1475 void sparse_init(void);
1477 #define sparse_init() do {} while (0)
1478 #define sparse_index_init(_sec, _nid) do {} while (0)
1479 #define pfn_in_present_section pfn_valid
1480 #define subsection_map_init(_pfn, _nr_pages) do {} while (0)
1481 #endif /* CONFIG_SPARSEMEM */
1484 * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we
1485 * need to check pfn validity within that MAX_ORDER_NR_PAGES block.
1486 * pfn_valid_within() should be used in this case; we optimise this away
1487 * when we have no holes within a MAX_ORDER_NR_PAGES block.
1489 #ifdef CONFIG_HOLES_IN_ZONE
1490 #define pfn_valid_within(pfn) pfn_valid(pfn)
1492 #define pfn_valid_within(pfn) (1)
1495 #endif /* !__GENERATING_BOUNDS.H */
1496 #endif /* !__ASSEMBLY__ */
1497 #endif /* _LINUX_MMZONE_H */