1 #ifndef _LINUX_MMZONE_H
2 #define _LINUX_MMZONE_H
5 #ifndef __GENERATING_BOUNDS_H
7 #include <linux/spinlock.h>
8 #include <linux/list.h>
9 #include <linux/wait.h>
10 #include <linux/bitops.h>
11 #include <linux/cache.h>
12 #include <linux/threads.h>
13 #include <linux/numa.h>
14 #include <linux/init.h>
15 #include <linux/seqlock.h>
16 #include <linux/nodemask.h>
17 #include <linux/pageblock-flags.h>
18 #include <generated/bounds.h>
19 #include <linux/atomic.h>
22 /* Free memory management - zoned buddy allocator. */
23 #ifndef CONFIG_FORCE_MAX_ZONEORDER
26 #define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER
28 #define MAX_ORDER_NR_PAGES (1 << (MAX_ORDER - 1))
31 * PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed
32 * costly to service. That is between allocation orders which should
33 * coalesce naturally under reasonable reclaim pressure and those which
36 #define PAGE_ALLOC_COSTLY_ORDER 3
42 MIGRATE_PCPTYPES, /* the number of types on the pcp lists */
43 MIGRATE_RESERVE = MIGRATE_PCPTYPES,
46 * MIGRATE_CMA migration type is designed to mimic the way
47 * ZONE_MOVABLE works. Only movable pages can be allocated
48 * from MIGRATE_CMA pageblocks and page allocator never
49 * implicitly change migration type of MIGRATE_CMA pageblock.
51 * The way to use it is to change migratetype of a range of
52 * pageblocks to MIGRATE_CMA which can be done by
53 * __free_pageblock_cma() function. What is important though
54 * is that a range of pageblocks must be aligned to
55 * MAX_ORDER_NR_PAGES should biggest page be bigger then
60 MIGRATE_ISOLATE, /* can't allocate from here */
65 # define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA)
66 # define cma_wmark_pages(zone) zone->min_cma_pages
68 # define is_migrate_cma(migratetype) false
69 # define cma_wmark_pages(zone) 0
72 #define for_each_migratetype_order(order, type) \
73 for (order = 0; order < MAX_ORDER; order++) \
74 for (type = 0; type < MIGRATE_TYPES; type++)
76 extern int page_group_by_mobility_disabled;
78 static inline int get_pageblock_migratetype(struct page *page)
80 return get_pageblock_flags_group(page, PB_migrate, PB_migrate_end);
84 struct list_head free_list[MIGRATE_TYPES];
85 unsigned long nr_free;
91 * zone->lock and zone->lru_lock are two of the hottest locks in the kernel.
92 * So add a wild amount of padding here to ensure that they fall into separate
93 * cachelines. There are very few zone structures in the machine, so space
94 * consumption is not a concern here.
96 #if defined(CONFIG_SMP)
99 } ____cacheline_internodealigned_in_smp;
100 #define ZONE_PADDING(name) struct zone_padding name;
102 #define ZONE_PADDING(name)
105 enum zone_stat_item {
106 /* First 128 byte cacheline (assuming 64 bit words) */
109 NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */
110 NR_ACTIVE_ANON, /* " " " " " */
111 NR_INACTIVE_FILE, /* " " " " " */
112 NR_ACTIVE_FILE, /* " " " " " */
113 NR_UNEVICTABLE, /* " " " " " */
114 NR_MLOCK, /* mlock()ed pages found and moved off LRU */
115 NR_ANON_PAGES, /* Mapped anonymous pages */
116 NR_FILE_MAPPED, /* pagecache pages mapped into pagetables.
117 only modified from process context */
122 NR_SLAB_UNRECLAIMABLE,
123 NR_PAGETABLE, /* used for pagetables */
125 /* Second 128 byte cacheline */
126 NR_UNSTABLE_NFS, /* NFS unstable pages */
129 NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */
130 NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */
131 NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */
132 NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */
133 NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */
134 NR_DIRTIED, /* page dirtyings since bootup */
135 NR_WRITTEN, /* page writings since bootup */
137 NUMA_HIT, /* allocated in intended node */
138 NUMA_MISS, /* allocated in non intended node */
139 NUMA_FOREIGN, /* was intended here, hit elsewhere */
140 NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */
141 NUMA_LOCAL, /* allocation from local node */
142 NUMA_OTHER, /* allocation from other node */
144 NR_ANON_TRANSPARENT_HUGEPAGES,
146 NR_VM_ZONE_STAT_ITEMS };
149 * We do arithmetic on the LRU lists in various places in the code,
150 * so it is important to keep the active lists LRU_ACTIVE higher in
151 * the array than the corresponding inactive lists, and to keep
152 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists.
154 * This has to be kept in sync with the statistics in zone_stat_item
155 * above and the descriptions in vmstat_text in mm/vmstat.c
162 LRU_INACTIVE_ANON = LRU_BASE,
163 LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE,
164 LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE,
165 LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE,
170 #define for_each_lru(lru) for (lru = 0; lru < NR_LRU_LISTS; lru++)
172 #define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_ACTIVE_FILE; lru++)
174 static inline int is_file_lru(enum lru_list lru)
176 return (lru == LRU_INACTIVE_FILE || lru == LRU_ACTIVE_FILE);
179 static inline int is_active_lru(enum lru_list lru)
181 return (lru == LRU_ACTIVE_ANON || lru == LRU_ACTIVE_FILE);
184 static inline int is_unevictable_lru(enum lru_list lru)
186 return (lru == LRU_UNEVICTABLE);
189 struct zone_reclaim_stat {
191 * The pageout code in vmscan.c keeps track of how many of the
192 * mem/swap backed and file backed pages are referenced.
193 * The higher the rotated/scanned ratio, the more valuable
196 * The anon LRU stats live in [0], file LRU stats in [1]
198 unsigned long recent_rotated[2];
199 unsigned long recent_scanned[2];
203 struct list_head lists[NR_LRU_LISTS];
204 struct zone_reclaim_stat reclaim_stat;
210 /* Mask used at gathering information at once (see memcontrol.c) */
211 #define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE))
212 #define LRU_ALL_ANON (BIT(LRU_INACTIVE_ANON) | BIT(LRU_ACTIVE_ANON))
213 #define LRU_ALL ((1 << NR_LRU_LISTS) - 1)
215 /* Isolate clean file */
216 #define ISOLATE_CLEAN ((__force isolate_mode_t)0x1)
217 /* Isolate unmapped file */
218 #define ISOLATE_UNMAPPED ((__force isolate_mode_t)0x2)
219 /* Isolate for asynchronous migration */
220 #define ISOLATE_ASYNC_MIGRATE ((__force isolate_mode_t)0x4)
221 /* Isolate unevictable pages */
222 #define ISOLATE_UNEVICTABLE ((__force isolate_mode_t)0x8)
224 /* LRU Isolation modes. */
225 typedef unsigned __bitwise__ isolate_mode_t;
227 enum zone_watermarks {
234 #define min_wmark_pages(z) (z->watermark[WMARK_MIN])
235 #define low_wmark_pages(z) (z->watermark[WMARK_LOW])
236 #define high_wmark_pages(z) (z->watermark[WMARK_HIGH])
238 struct per_cpu_pages {
239 int count; /* number of pages in the list */
240 int high; /* high watermark, emptying needed */
241 int batch; /* chunk size for buddy add/remove */
243 /* Lists of pages, one per migrate type stored on the pcp-lists */
244 struct list_head lists[MIGRATE_PCPTYPES];
247 struct per_cpu_pageset {
248 struct per_cpu_pages pcp;
254 s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS];
258 #endif /* !__GENERATING_BOUNDS.H */
261 #ifdef CONFIG_ZONE_DMA
263 * ZONE_DMA is used when there are devices that are not able
264 * to do DMA to all of addressable memory (ZONE_NORMAL). Then we
265 * carve out the portion of memory that is needed for these devices.
266 * The range is arch specific.
271 * ---------------------------
272 * parisc, ia64, sparc <4G
275 * alpha Unlimited or 0-16MB.
277 * i386, x86_64 and multiple other arches
282 #ifdef CONFIG_ZONE_DMA32
284 * x86_64 needs two ZONE_DMAs because it supports devices that are
285 * only able to do DMA to the lower 16M but also 32 bit devices that
286 * can only do DMA areas below 4G.
291 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be
292 * performed on pages in ZONE_NORMAL if the DMA devices support
293 * transfers to all addressable memory.
296 #ifdef CONFIG_HIGHMEM
298 * A memory area that is only addressable by the kernel through
299 * mapping portions into its own address space. This is for example
300 * used by i386 to allow the kernel to address the memory beyond
301 * 900MB. The kernel will set up special mappings (page
302 * table entries on i386) for each page that the kernel needs to
311 #ifndef __GENERATING_BOUNDS_H
314 * When a memory allocation must conform to specific limitations (such
315 * as being suitable for DMA) the caller will pass in hints to the
316 * allocator in the gfp_mask, in the zone modifier bits. These bits
317 * are used to select a priority ordered list of memory zones which
318 * match the requested limits. See gfp_zone() in include/linux/gfp.h
322 #define ZONES_SHIFT 0
323 #elif MAX_NR_ZONES <= 2
324 #define ZONES_SHIFT 1
325 #elif MAX_NR_ZONES <= 4
326 #define ZONES_SHIFT 2
328 #error ZONES_SHIFT -- too many zones configured adjust calculation
332 /* Fields commonly accessed by the page allocator */
334 /* zone watermarks, access with *_wmark_pages(zone) macros */
335 unsigned long watermark[NR_WMARK];
338 * When free pages are below this point, additional steps are taken
339 * when reading the number of free pages to avoid per-cpu counter
340 * drift allowing watermarks to be breached
342 unsigned long percpu_drift_mark;
345 * We don't know if the memory that we're going to allocate will be freeable
346 * or/and it will be released eventually, so to avoid totally wasting several
347 * GB of ram we must reserve some of the lower zone memory (otherwise we risk
348 * to run OOM on the lower zones despite there's tons of freeable ram
349 * on the higher zones). This array is recalculated at runtime if the
350 * sysctl_lowmem_reserve_ratio sysctl changes.
352 unsigned long lowmem_reserve[MAX_NR_ZONES];
355 * This is a per-zone reserve of pages that should not be
356 * considered dirtyable memory.
358 unsigned long dirty_balance_reserve;
363 * zone reclaim becomes active if more unmapped pages exist.
365 unsigned long min_unmapped_pages;
366 unsigned long min_slab_pages;
368 struct per_cpu_pageset __percpu *pageset;
370 * free areas of different sizes
373 int all_unreclaimable; /* All pages pinned */
374 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
375 /* Set to true when the PG_migrate_skip bits should be cleared */
376 bool compact_blockskip_flush;
378 /* pfns where compaction scanners should start */
379 unsigned long compact_cached_free_pfn;
380 unsigned long compact_cached_migrate_pfn;
382 #ifdef CONFIG_MEMORY_HOTPLUG
383 /* see spanned/present_pages for more description */
384 seqlock_t span_seqlock;
388 * CMA needs to increase watermark levels during the allocation
389 * process to make sure that the system is not starved.
391 unsigned long min_cma_pages;
393 struct free_area free_area[MAX_ORDER];
395 #ifndef CONFIG_SPARSEMEM
397 * Flags for a pageblock_nr_pages block. See pageblock-flags.h.
398 * In SPARSEMEM, this map is stored in struct mem_section
400 unsigned long *pageblock_flags;
401 #endif /* CONFIG_SPARSEMEM */
403 #ifdef CONFIG_COMPACTION
405 * On compaction failure, 1<<compact_defer_shift compactions
406 * are skipped before trying again. The number attempted since
407 * last failure is tracked with compact_considered.
409 unsigned int compact_considered;
410 unsigned int compact_defer_shift;
411 int compact_order_failed;
416 /* Fields commonly accessed by the page reclaim scanner */
418 struct lruvec lruvec;
420 unsigned long pages_scanned; /* since last reclaim */
421 unsigned long flags; /* zone flags, see below */
423 /* Zone statistics */
424 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
427 * The target ratio of ACTIVE_ANON to INACTIVE_ANON pages on
428 * this zone's LRU. Maintained by the pageout code.
430 unsigned int inactive_ratio;
434 /* Rarely used or read-mostly fields */
437 * wait_table -- the array holding the hash table
438 * wait_table_hash_nr_entries -- the size of the hash table array
439 * wait_table_bits -- wait_table_size == (1 << wait_table_bits)
441 * The purpose of all these is to keep track of the people
442 * waiting for a page to become available and make them
443 * runnable again when possible. The trouble is that this
444 * consumes a lot of space, especially when so few things
445 * wait on pages at a given time. So instead of using
446 * per-page waitqueues, we use a waitqueue hash table.
448 * The bucket discipline is to sleep on the same queue when
449 * colliding and wake all in that wait queue when removing.
450 * When something wakes, it must check to be sure its page is
451 * truly available, a la thundering herd. The cost of a
452 * collision is great, but given the expected load of the
453 * table, they should be so rare as to be outweighed by the
454 * benefits from the saved space.
456 * __wait_on_page_locked() and unlock_page() in mm/filemap.c, are the
457 * primary users of these fields, and in mm/page_alloc.c
458 * free_area_init_core() performs the initialization of them.
460 wait_queue_head_t * wait_table;
461 unsigned long wait_table_hash_nr_entries;
462 unsigned long wait_table_bits;
465 * Discontig memory support fields.
467 struct pglist_data *zone_pgdat;
468 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
469 unsigned long zone_start_pfn;
472 * zone_start_pfn, spanned_pages and present_pages are all
473 * protected by span_seqlock. It is a seqlock because it has
474 * to be read outside of zone->lock, and it is done in the main
475 * allocator path. But, it is written quite infrequently.
477 * The lock is declared along with zone->lock because it is
478 * frequently read in proximity to zone->lock. It's good to
479 * give them a chance of being in the same cacheline.
481 unsigned long spanned_pages; /* total size, including holes */
482 unsigned long present_pages; /* amount of memory (excluding holes) */
485 * rarely used fields:
488 #ifdef CONFIG_MEMORY_ISOLATION
490 * the number of MIGRATE_ISOLATE *pageblock*.
491 * We need this for free page counting. Look at zone_watermark_ok_safe.
492 * It's protected by zone->lock
494 int nr_pageblock_isolate;
496 } ____cacheline_internodealigned_in_smp;
499 ZONE_RECLAIM_LOCKED, /* prevents concurrent reclaim */
500 ZONE_OOM_LOCKED, /* zone is in OOM killer zonelist */
501 ZONE_CONGESTED, /* zone has many dirty pages backed by
506 static inline void zone_set_flag(struct zone *zone, zone_flags_t flag)
508 set_bit(flag, &zone->flags);
511 static inline int zone_test_and_set_flag(struct zone *zone, zone_flags_t flag)
513 return test_and_set_bit(flag, &zone->flags);
516 static inline void zone_clear_flag(struct zone *zone, zone_flags_t flag)
518 clear_bit(flag, &zone->flags);
521 static inline int zone_is_reclaim_congested(const struct zone *zone)
523 return test_bit(ZONE_CONGESTED, &zone->flags);
526 static inline int zone_is_reclaim_locked(const struct zone *zone)
528 return test_bit(ZONE_RECLAIM_LOCKED, &zone->flags);
531 static inline int zone_is_oom_locked(const struct zone *zone)
533 return test_bit(ZONE_OOM_LOCKED, &zone->flags);
537 * The "priority" of VM scanning is how much of the queues we will scan in one
538 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
539 * queues ("queue_length >> 12") during an aging round.
541 #define DEF_PRIORITY 12
543 /* Maximum number of zones on a zonelist */
544 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
549 * The NUMA zonelists are doubled because we need zonelists that restrict the
550 * allocations to a single node for GFP_THISNODE.
552 * [0] : Zonelist with fallback
553 * [1] : No fallback (GFP_THISNODE)
555 #define MAX_ZONELISTS 2
559 * We cache key information from each zonelist for smaller cache
560 * footprint when scanning for free pages in get_page_from_freelist().
562 * 1) The BITMAP fullzones tracks which zones in a zonelist have come
563 * up short of free memory since the last time (last_fullzone_zap)
564 * we zero'd fullzones.
565 * 2) The array z_to_n[] maps each zone in the zonelist to its node
566 * id, so that we can efficiently evaluate whether that node is
567 * set in the current tasks mems_allowed.
569 * Both fullzones and z_to_n[] are one-to-one with the zonelist,
570 * indexed by a zones offset in the zonelist zones[] array.
572 * The get_page_from_freelist() routine does two scans. During the
573 * first scan, we skip zones whose corresponding bit in 'fullzones'
574 * is set or whose corresponding node in current->mems_allowed (which
575 * comes from cpusets) is not set. During the second scan, we bypass
576 * this zonelist_cache, to ensure we look methodically at each zone.
578 * Once per second, we zero out (zap) fullzones, forcing us to
579 * reconsider nodes that might have regained more free memory.
580 * The field last_full_zap is the time we last zapped fullzones.
582 * This mechanism reduces the amount of time we waste repeatedly
583 * reexaming zones for free memory when they just came up low on
584 * memory momentarilly ago.
586 * The zonelist_cache struct members logically belong in struct
587 * zonelist. However, the mempolicy zonelists constructed for
588 * MPOL_BIND are intentionally variable length (and usually much
589 * shorter). A general purpose mechanism for handling structs with
590 * multiple variable length members is more mechanism than we want
591 * here. We resort to some special case hackery instead.
593 * The MPOL_BIND zonelists don't need this zonelist_cache (in good
594 * part because they are shorter), so we put the fixed length stuff
595 * at the front of the zonelist struct, ending in a variable length
596 * zones[], as is needed by MPOL_BIND.
598 * Then we put the optional zonelist cache on the end of the zonelist
599 * struct. This optional stuff is found by a 'zlcache_ptr' pointer in
600 * the fixed length portion at the front of the struct. This pointer
601 * both enables us to find the zonelist cache, and in the case of
602 * MPOL_BIND zonelists, (which will just set the zlcache_ptr to NULL)
603 * to know that the zonelist cache is not there.
605 * The end result is that struct zonelists come in two flavors:
606 * 1) The full, fixed length version, shown below, and
607 * 2) The custom zonelists for MPOL_BIND.
608 * The custom MPOL_BIND zonelists have a NULL zlcache_ptr and no zlcache.
610 * Even though there may be multiple CPU cores on a node modifying
611 * fullzones or last_full_zap in the same zonelist_cache at the same
612 * time, we don't lock it. This is just hint data - if it is wrong now
613 * and then, the allocator will still function, perhaps a bit slower.
617 struct zonelist_cache {
618 unsigned short z_to_n[MAX_ZONES_PER_ZONELIST]; /* zone->nid */
619 DECLARE_BITMAP(fullzones, MAX_ZONES_PER_ZONELIST); /* zone full? */
620 unsigned long last_full_zap; /* when last zap'd (jiffies) */
623 #define MAX_ZONELISTS 1
624 struct zonelist_cache;
628 * This struct contains information about a zone in a zonelist. It is stored
629 * here to avoid dereferences into large structures and lookups of tables
632 struct zone *zone; /* Pointer to actual zone */
633 int zone_idx; /* zone_idx(zoneref->zone) */
637 * One allocation request operates on a zonelist. A zonelist
638 * is a list of zones, the first one is the 'goal' of the
639 * allocation, the other zones are fallback zones, in decreasing
642 * If zlcache_ptr is not NULL, then it is just the address of zlcache,
643 * as explained above. If zlcache_ptr is NULL, there is no zlcache.
645 * To speed the reading of the zonelist, the zonerefs contain the zone index
646 * of the entry being read. Helper functions to access information given
647 * a struct zoneref are
649 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs
650 * zonelist_zone_idx() - Return the index of the zone for an entry
651 * zonelist_node_idx() - Return the index of the node for an entry
654 struct zonelist_cache *zlcache_ptr; // NULL or &zlcache
655 struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1];
657 struct zonelist_cache zlcache; // optional ...
661 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
662 struct node_active_region {
663 unsigned long start_pfn;
664 unsigned long end_pfn;
667 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
669 #ifndef CONFIG_DISCONTIGMEM
670 /* The array of struct pages - for discontigmem use pgdat->lmem_map */
671 extern struct page *mem_map;
675 * The pg_data_t structure is used in machines with CONFIG_DISCONTIGMEM
676 * (mostly NUMA machines?) to denote a higher-level memory zone than the
679 * On NUMA machines, each NUMA node would have a pg_data_t to describe
680 * it's memory layout.
682 * Memory statistics and page replacement data structures are maintained on a
686 typedef struct pglist_data {
687 struct zone node_zones[MAX_NR_ZONES];
688 struct zonelist node_zonelists[MAX_ZONELISTS];
690 #ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */
691 struct page *node_mem_map;
693 struct page_cgroup *node_page_cgroup;
696 #ifndef CONFIG_NO_BOOTMEM
697 struct bootmem_data *bdata;
699 #ifdef CONFIG_MEMORY_HOTPLUG
701 * Must be held any time you expect node_start_pfn, node_present_pages
702 * or node_spanned_pages stay constant. Holding this will also
703 * guarantee that any pfn_valid() stays that way.
705 * Nests above zone->lock and zone->size_seqlock.
707 spinlock_t node_size_lock;
709 unsigned long node_start_pfn;
710 unsigned long node_present_pages; /* total number of physical pages */
711 unsigned long node_spanned_pages; /* total size of physical page
712 range, including holes */
714 nodemask_t reclaim_nodes; /* Nodes allowed to reclaim from */
715 wait_queue_head_t kswapd_wait;
716 wait_queue_head_t pfmemalloc_wait;
717 struct task_struct *kswapd; /* Protected by lock_memory_hotplug() */
718 int kswapd_max_order;
719 enum zone_type classzone_idx;
722 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
723 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
724 #ifdef CONFIG_FLAT_NODE_MEM_MAP
725 #define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr))
727 #define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr))
729 #define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr))
731 #define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn)
733 #define node_end_pfn(nid) ({\
734 pg_data_t *__pgdat = NODE_DATA(nid);\
735 __pgdat->node_start_pfn + __pgdat->node_spanned_pages;\
738 #include <linux/memory_hotplug.h>
740 extern struct mutex zonelists_mutex;
741 void build_all_zonelists(pg_data_t *pgdat, struct zone *zone);
742 void wakeup_kswapd(struct zone *zone, int order, enum zone_type classzone_idx);
743 bool zone_watermark_ok(struct zone *z, int order, unsigned long mark,
744 int classzone_idx, int alloc_flags);
745 bool zone_watermark_ok_safe(struct zone *z, int order, unsigned long mark,
746 int classzone_idx, int alloc_flags);
747 enum memmap_context {
751 extern int init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
753 enum memmap_context context);
755 extern void lruvec_init(struct lruvec *lruvec, struct zone *zone);
757 static inline struct zone *lruvec_zone(struct lruvec *lruvec)
762 return container_of(lruvec, struct zone, lruvec);
766 #ifdef CONFIG_HAVE_MEMORY_PRESENT
767 void memory_present(int nid, unsigned long start, unsigned long end);
769 static inline void memory_present(int nid, unsigned long start, unsigned long end) {}
772 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
773 int local_memory_node(int node_id);
775 static inline int local_memory_node(int node_id) { return node_id; };
778 #ifdef CONFIG_NEED_NODE_MEMMAP_SIZE
779 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
783 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
785 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones)
787 static inline int populated_zone(struct zone *zone)
789 return (!!zone->present_pages);
792 extern int movable_zone;
794 static inline int zone_movable_is_highmem(void)
796 #if defined(CONFIG_HIGHMEM) && defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
797 return movable_zone == ZONE_HIGHMEM;
803 static inline int is_highmem_idx(enum zone_type idx)
805 #ifdef CONFIG_HIGHMEM
806 return (idx == ZONE_HIGHMEM ||
807 (idx == ZONE_MOVABLE && zone_movable_is_highmem()));
813 static inline int is_normal_idx(enum zone_type idx)
815 return (idx == ZONE_NORMAL);
819 * is_highmem - helper function to quickly check if a struct zone is a
820 * highmem zone or not. This is an attempt to keep references
821 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
822 * @zone - pointer to struct zone variable
824 static inline int is_highmem(struct zone *zone)
826 #ifdef CONFIG_HIGHMEM
827 int zone_off = (char *)zone - (char *)zone->zone_pgdat->node_zones;
828 return zone_off == ZONE_HIGHMEM * sizeof(*zone) ||
829 (zone_off == ZONE_MOVABLE * sizeof(*zone) &&
830 zone_movable_is_highmem());
836 static inline int is_normal(struct zone *zone)
838 return zone == zone->zone_pgdat->node_zones + ZONE_NORMAL;
841 static inline int is_dma32(struct zone *zone)
843 #ifdef CONFIG_ZONE_DMA32
844 return zone == zone->zone_pgdat->node_zones + ZONE_DMA32;
850 static inline int is_dma(struct zone *zone)
852 #ifdef CONFIG_ZONE_DMA
853 return zone == zone->zone_pgdat->node_zones + ZONE_DMA;
859 /* These two functions are used to setup the per zone pages min values */
861 int min_free_kbytes_sysctl_handler(struct ctl_table *, int,
862 void __user *, size_t *, loff_t *);
863 extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1];
864 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int,
865 void __user *, size_t *, loff_t *);
866 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int,
867 void __user *, size_t *, loff_t *);
868 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int,
869 void __user *, size_t *, loff_t *);
870 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int,
871 void __user *, size_t *, loff_t *);
873 extern int numa_zonelist_order_handler(struct ctl_table *, int,
874 void __user *, size_t *, loff_t *);
875 extern char numa_zonelist_order[];
876 #define NUMA_ZONELIST_ORDER_LEN 16 /* string buffer size */
878 #ifndef CONFIG_NEED_MULTIPLE_NODES
880 extern struct pglist_data contig_page_data;
881 #define NODE_DATA(nid) (&contig_page_data)
882 #define NODE_MEM_MAP(nid) mem_map
884 #else /* CONFIG_NEED_MULTIPLE_NODES */
886 #include <asm/mmzone.h>
888 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
890 extern struct pglist_data *first_online_pgdat(void);
891 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
892 extern struct zone *next_zone(struct zone *zone);
895 * for_each_online_pgdat - helper macro to iterate over all online nodes
896 * @pgdat - pointer to a pg_data_t variable
898 #define for_each_online_pgdat(pgdat) \
899 for (pgdat = first_online_pgdat(); \
901 pgdat = next_online_pgdat(pgdat))
903 * for_each_zone - helper macro to iterate over all memory zones
904 * @zone - pointer to struct zone variable
906 * The user only needs to declare the zone variable, for_each_zone
909 #define for_each_zone(zone) \
910 for (zone = (first_online_pgdat())->node_zones; \
912 zone = next_zone(zone))
914 #define for_each_populated_zone(zone) \
915 for (zone = (first_online_pgdat())->node_zones; \
917 zone = next_zone(zone)) \
918 if (!populated_zone(zone)) \
922 static inline struct zone *zonelist_zone(struct zoneref *zoneref)
924 return zoneref->zone;
927 static inline int zonelist_zone_idx(struct zoneref *zoneref)
929 return zoneref->zone_idx;
932 static inline int zonelist_node_idx(struct zoneref *zoneref)
935 /* zone_to_nid not available in this context */
936 return zoneref->zone->node;
939 #endif /* CONFIG_NUMA */
943 * 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
944 * @z - The cursor used as a starting point for the search
945 * @highest_zoneidx - The zone index of the highest zone to return
946 * @nodes - An optional nodemask to filter the zonelist with
947 * @zone - The first suitable zone found is returned via this parameter
949 * This function returns the next zone at or below a given zone index that is
950 * within the allowed nodemask using a cursor as the starting point for the
951 * search. The zoneref returned is a cursor that represents the current zone
952 * being examined. It should be advanced by one before calling
953 * next_zones_zonelist again.
955 struct zoneref *next_zones_zonelist(struct zoneref *z,
956 enum zone_type highest_zoneidx,
961 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
962 * @zonelist - The zonelist to search for a suitable zone
963 * @highest_zoneidx - The zone index of the highest zone to return
964 * @nodes - An optional nodemask to filter the zonelist with
965 * @zone - The first suitable zone found is returned via this parameter
967 * This function returns the first zone at or below a given zone index that is
968 * within the allowed nodemask. The zoneref returned is a cursor that can be
969 * used to iterate the zonelist with next_zones_zonelist by advancing it by
970 * one before calling.
972 static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
973 enum zone_type highest_zoneidx,
977 return next_zones_zonelist(zonelist->_zonerefs, highest_zoneidx, nodes,
982 * 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
983 * @zone - The current zone in the iterator
984 * @z - The current pointer within zonelist->zones being iterated
985 * @zlist - The zonelist being iterated
986 * @highidx - The zone index of the highest zone to return
987 * @nodemask - Nodemask allowed by the allocator
989 * This iterator iterates though all zones at or below a given zone index and
990 * within a given nodemask
992 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
993 for (z = first_zones_zonelist(zlist, highidx, nodemask, &zone); \
995 z = next_zones_zonelist(++z, highidx, nodemask, &zone)) \
998 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
999 * @zone - The current zone in the iterator
1000 * @z - The current pointer within zonelist->zones being iterated
1001 * @zlist - The zonelist being iterated
1002 * @highidx - The zone index of the highest zone to return
1004 * This iterator iterates though all zones at or below a given zone index.
1006 #define for_each_zone_zonelist(zone, z, zlist, highidx) \
1007 for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL)
1009 #ifdef CONFIG_SPARSEMEM
1010 #include <asm/sparsemem.h>
1013 #if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \
1014 !defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
1015 static inline unsigned long early_pfn_to_nid(unsigned long pfn)
1021 #ifdef CONFIG_FLATMEM
1022 #define pfn_to_nid(pfn) (0)
1025 #ifdef CONFIG_SPARSEMEM
1028 * SECTION_SHIFT #bits space required to store a section #
1030 * PA_SECTION_SHIFT physical address to/from section number
1031 * PFN_SECTION_SHIFT pfn to/from section number
1033 #define SECTIONS_SHIFT (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS)
1035 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS)
1036 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
1038 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT)
1040 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT)
1041 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1))
1043 #define SECTION_BLOCKFLAGS_BITS \
1044 ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS)
1046 #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
1047 #error Allocator MAX_ORDER exceeds SECTION_SIZE
1050 #define pfn_to_section_nr(pfn) ((pfn) >> PFN_SECTION_SHIFT)
1051 #define section_nr_to_pfn(sec) ((sec) << PFN_SECTION_SHIFT)
1053 #define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK)
1054 #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK)
1058 struct mem_section {
1060 * This is, logically, a pointer to an array of struct
1061 * pages. However, it is stored with some other magic.
1062 * (see sparse.c::sparse_init_one_section())
1064 * Additionally during early boot we encode node id of
1065 * the location of the section here to guide allocation.
1066 * (see sparse.c::memory_present())
1068 * Making it a UL at least makes someone do a cast
1069 * before using it wrong.
1071 unsigned long section_mem_map;
1073 /* See declaration of similar field in struct zone */
1074 unsigned long *pageblock_flags;
1077 * If !SPARSEMEM, pgdat doesn't have page_cgroup pointer. We use
1078 * section. (see memcontrol.h/page_cgroup.h about this.)
1080 struct page_cgroup *page_cgroup;
1085 #ifdef CONFIG_SPARSEMEM_EXTREME
1086 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section))
1088 #define SECTIONS_PER_ROOT 1
1091 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
1092 #define NR_SECTION_ROOTS DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT)
1093 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1)
1095 #ifdef CONFIG_SPARSEMEM_EXTREME
1096 extern struct mem_section *mem_section[NR_SECTION_ROOTS];
1098 extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
1101 static inline struct mem_section *__nr_to_section(unsigned long nr)
1103 if (!mem_section[SECTION_NR_TO_ROOT(nr)])
1105 return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];
1107 extern int __section_nr(struct mem_section* ms);
1108 extern unsigned long usemap_size(void);
1111 * We use the lower bits of the mem_map pointer to store
1112 * a little bit of information. There should be at least
1113 * 3 bits here due to 32-bit alignment.
1115 #define SECTION_MARKED_PRESENT (1UL<<0)
1116 #define SECTION_HAS_MEM_MAP (1UL<<1)
1117 #define SECTION_MAP_LAST_BIT (1UL<<2)
1118 #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1))
1119 #define SECTION_NID_SHIFT 2
1121 static inline struct page *__section_mem_map_addr(struct mem_section *section)
1123 unsigned long map = section->section_mem_map;
1124 map &= SECTION_MAP_MASK;
1125 return (struct page *)map;
1128 static inline int present_section(struct mem_section *section)
1130 return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
1133 static inline int present_section_nr(unsigned long nr)
1135 return present_section(__nr_to_section(nr));
1138 static inline int valid_section(struct mem_section *section)
1140 return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
1143 static inline int valid_section_nr(unsigned long nr)
1145 return valid_section(__nr_to_section(nr));
1148 static inline struct mem_section *__pfn_to_section(unsigned long pfn)
1150 return __nr_to_section(pfn_to_section_nr(pfn));
1153 #ifndef CONFIG_HAVE_ARCH_PFN_VALID
1154 static inline int pfn_valid(unsigned long pfn)
1156 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
1158 return valid_section(__nr_to_section(pfn_to_section_nr(pfn)));
1162 static inline int pfn_present(unsigned long pfn)
1164 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
1166 return present_section(__nr_to_section(pfn_to_section_nr(pfn)));
1170 * These are _only_ used during initialisation, therefore they
1171 * can use __initdata ... They could have names to indicate
1175 #define pfn_to_nid(pfn) \
1177 unsigned long __pfn_to_nid_pfn = (pfn); \
1178 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \
1181 #define pfn_to_nid(pfn) (0)
1184 #define early_pfn_valid(pfn) pfn_valid(pfn)
1185 void sparse_init(void);
1187 #define sparse_init() do {} while (0)
1188 #define sparse_index_init(_sec, _nid) do {} while (0)
1189 #endif /* CONFIG_SPARSEMEM */
1191 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1192 bool early_pfn_in_nid(unsigned long pfn, int nid);
1194 #define early_pfn_in_nid(pfn, nid) (1)
1197 #ifndef early_pfn_valid
1198 #define early_pfn_valid(pfn) (1)
1201 void memory_present(int nid, unsigned long start, unsigned long end);
1202 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
1205 * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we
1206 * need to check pfn validility within that MAX_ORDER_NR_PAGES block.
1207 * pfn_valid_within() should be used in this case; we optimise this away
1208 * when we have no holes within a MAX_ORDER_NR_PAGES block.
1210 #ifdef CONFIG_HOLES_IN_ZONE
1211 #define pfn_valid_within(pfn) pfn_valid(pfn)
1213 #define pfn_valid_within(pfn) (1)
1216 #ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
1218 * pfn_valid() is meant to be able to tell if a given PFN has valid memmap
1219 * associated with it or not. In FLATMEM, it is expected that holes always
1220 * have valid memmap as long as there is valid PFNs either side of the hole.
1221 * In SPARSEMEM, it is assumed that a valid section has a memmap for the
1224 * However, an ARM, and maybe other embedded architectures in the future
1225 * free memmap backing holes to save memory on the assumption the memmap is
1226 * never used. The page_zone linkages are then broken even though pfn_valid()
1227 * returns true. A walker of the full memmap must then do this additional
1228 * check to ensure the memmap they are looking at is sane by making sure
1229 * the zone and PFN linkages are still valid. This is expensive, but walkers
1230 * of the full memmap are extremely rare.
1232 int memmap_valid_within(unsigned long pfn,
1233 struct page *page, struct zone *zone);
1235 static inline int memmap_valid_within(unsigned long pfn,
1236 struct page *page, struct zone *zone)
1240 #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */
1242 #endif /* !__GENERATING_BOUNDS.H */
1243 #endif /* !__ASSEMBLY__ */
1244 #endif /* _LINUX_MMZONE_H */