Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / include / linux / mmzone.h
blob02ecb0189b1d9d1fcf0fff2900178045b40cedff
1 #ifndef _LINUX_MMZONE_H
2 #define _LINUX_MMZONE_H
4 #ifndef __ASSEMBLY__
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 <asm/atomic.h>
20 #include <asm/page.h>
22 /* Free memory management - zoned buddy allocator. */
23 #ifndef CONFIG_FORCE_MAX_ZONEORDER
24 #define MAX_ORDER 11
25 #else
26 #define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER
27 #endif
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 * coelesce naturally under reasonable reclaim pressure and those which
34 * will not.
36 #define PAGE_ALLOC_COSTLY_ORDER 3
38 #define MIGRATE_UNMOVABLE 0
39 #define MIGRATE_RECLAIMABLE 1
40 #define MIGRATE_MOVABLE 2
41 #define MIGRATE_PCPTYPES 3 /* the number of types on the pcp lists */
42 #define MIGRATE_RESERVE 3
43 #define MIGRATE_ISOLATE 4 /* can't allocate from here */
44 #define MIGRATE_TYPES 5
46 #define for_each_migratetype_order(order, type) \
47 for (order = 0; order < MAX_ORDER; order++) \
48 for (type = 0; type < MIGRATE_TYPES; type++)
50 extern int page_group_by_mobility_disabled;
52 static inline int get_pageblock_migratetype(struct page *page)
54 return get_pageblock_flags_group(page, PB_migrate, PB_migrate_end);
57 struct free_area {
58 struct list_head free_list[MIGRATE_TYPES];
59 unsigned long nr_free;
62 struct pglist_data;
65 * zone->lock and zone->lru_lock are two of the hottest locks in the kernel.
66 * So add a wild amount of padding here to ensure that they fall into separate
67 * cachelines. There are very few zone structures in the machine, so space
68 * consumption is not a concern here.
70 #if defined(CONFIG_SMP)
71 struct zone_padding {
72 char x[0];
73 } ____cacheline_internodealigned_in_smp;
74 #define ZONE_PADDING(name) struct zone_padding name;
75 #else
76 #define ZONE_PADDING(name)
77 #endif
79 enum zone_stat_item {
80 /* First 128 byte cacheline (assuming 64 bit words) */
81 NR_FREE_PAGES,
82 NR_LRU_BASE,
83 NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */
84 NR_ACTIVE_ANON, /* " " " " " */
85 NR_INACTIVE_FILE, /* " " " " " */
86 NR_ACTIVE_FILE, /* " " " " " */
87 NR_UNEVICTABLE, /* " " " " " */
88 NR_MLOCK, /* mlock()ed pages found and moved off LRU */
89 NR_ANON_PAGES, /* Mapped anonymous pages */
90 NR_FILE_MAPPED, /* pagecache pages mapped into pagetables.
91 only modified from process context */
92 NR_FILE_PAGES,
93 NR_FILE_DIRTY,
94 NR_WRITEBACK,
95 NR_SLAB_RECLAIMABLE,
96 NR_SLAB_UNRECLAIMABLE,
97 NR_PAGETABLE, /* used for pagetables */
98 NR_KERNEL_STACK,
99 /* Second 128 byte cacheline */
100 NR_UNSTABLE_NFS, /* NFS unstable pages */
101 NR_BOUNCE,
102 NR_VMSCAN_WRITE,
103 NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */
104 NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */
105 NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */
106 NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */
107 NR_DIRTIED, /* page dirtyings since bootup */
108 NR_WRITTEN, /* page writings since bootup */
109 #ifdef CONFIG_NUMA
110 NUMA_HIT, /* allocated in intended node */
111 NUMA_MISS, /* allocated in non intended node */
112 NUMA_FOREIGN, /* was intended here, hit elsewhere */
113 NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */
114 NUMA_LOCAL, /* allocation from local node */
115 NUMA_OTHER, /* allocation from other node */
116 #endif
117 NR_ANON_TRANSPARENT_HUGEPAGES,
118 NR_VM_ZONE_STAT_ITEMS };
121 * We do arithmetic on the LRU lists in various places in the code,
122 * so it is important to keep the active lists LRU_ACTIVE higher in
123 * the array than the corresponding inactive lists, and to keep
124 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists.
126 * This has to be kept in sync with the statistics in zone_stat_item
127 * above and the descriptions in vmstat_text in mm/vmstat.c
129 #define LRU_BASE 0
130 #define LRU_ACTIVE 1
131 #define LRU_FILE 2
133 enum lru_list {
134 LRU_INACTIVE_ANON = LRU_BASE,
135 LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE,
136 LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE,
137 LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE,
138 LRU_UNEVICTABLE,
139 NR_LRU_LISTS
142 #define for_each_lru(l) for (l = 0; l < NR_LRU_LISTS; l++)
144 #define for_each_evictable_lru(l) for (l = 0; l <= LRU_ACTIVE_FILE; l++)
146 static inline int is_file_lru(enum lru_list l)
148 return (l == LRU_INACTIVE_FILE || l == LRU_ACTIVE_FILE);
151 static inline int is_active_lru(enum lru_list l)
153 return (l == LRU_ACTIVE_ANON || l == LRU_ACTIVE_FILE);
156 static inline int is_unevictable_lru(enum lru_list l)
158 return (l == LRU_UNEVICTABLE);
161 enum zone_watermarks {
162 WMARK_MIN,
163 WMARK_LOW,
164 WMARK_HIGH,
165 NR_WMARK
168 #define min_wmark_pages(z) (z->watermark[WMARK_MIN])
169 #define low_wmark_pages(z) (z->watermark[WMARK_LOW])
170 #define high_wmark_pages(z) (z->watermark[WMARK_HIGH])
172 struct per_cpu_pages {
173 int count; /* number of pages in the list */
174 int high; /* high watermark, emptying needed */
175 int batch; /* chunk size for buddy add/remove */
177 /* Lists of pages, one per migrate type stored on the pcp-lists */
178 struct list_head lists[MIGRATE_PCPTYPES];
181 struct per_cpu_pageset {
182 struct per_cpu_pages pcp;
183 #ifdef CONFIG_NUMA
184 s8 expire;
185 #endif
186 #ifdef CONFIG_SMP
187 s8 stat_threshold;
188 s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS];
189 #endif
192 #endif /* !__GENERATING_BOUNDS.H */
194 enum zone_type {
195 #ifdef CONFIG_ZONE_DMA
197 * ZONE_DMA is used when there are devices that are not able
198 * to do DMA to all of addressable memory (ZONE_NORMAL). Then we
199 * carve out the portion of memory that is needed for these devices.
200 * The range is arch specific.
202 * Some examples
204 * Architecture Limit
205 * ---------------------------
206 * parisc, ia64, sparc <4G
207 * s390 <2G
208 * arm Various
209 * alpha Unlimited or 0-16MB.
211 * i386, x86_64 and multiple other arches
212 * <16M.
214 ZONE_DMA,
215 #endif
216 #ifdef CONFIG_ZONE_DMA32
218 * x86_64 needs two ZONE_DMAs because it supports devices that are
219 * only able to do DMA to the lower 16M but also 32 bit devices that
220 * can only do DMA areas below 4G.
222 ZONE_DMA32,
223 #endif
225 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be
226 * performed on pages in ZONE_NORMAL if the DMA devices support
227 * transfers to all addressable memory.
229 ZONE_NORMAL,
230 #ifdef CONFIG_HIGHMEM
232 * A memory area that is only addressable by the kernel through
233 * mapping portions into its own address space. This is for example
234 * used by i386 to allow the kernel to address the memory beyond
235 * 900MB. The kernel will set up special mappings (page
236 * table entries on i386) for each page that the kernel needs to
237 * access.
239 ZONE_HIGHMEM,
240 #endif
241 ZONE_MOVABLE,
242 __MAX_NR_ZONES
245 #ifndef __GENERATING_BOUNDS_H
248 * When a memory allocation must conform to specific limitations (such
249 * as being suitable for DMA) the caller will pass in hints to the
250 * allocator in the gfp_mask, in the zone modifier bits. These bits
251 * are used to select a priority ordered list of memory zones which
252 * match the requested limits. See gfp_zone() in include/linux/gfp.h
255 #if MAX_NR_ZONES < 2
256 #define ZONES_SHIFT 0
257 #elif MAX_NR_ZONES <= 2
258 #define ZONES_SHIFT 1
259 #elif MAX_NR_ZONES <= 4
260 #define ZONES_SHIFT 2
261 #else
262 #error ZONES_SHIFT -- too many zones configured adjust calculation
263 #endif
265 struct zone_reclaim_stat {
267 * The pageout code in vmscan.c keeps track of how many of the
268 * mem/swap backed and file backed pages are refeferenced.
269 * The higher the rotated/scanned ratio, the more valuable
270 * that cache is.
272 * The anon LRU stats live in [0], file LRU stats in [1]
274 unsigned long recent_rotated[2];
275 unsigned long recent_scanned[2];
278 * accumulated for batching
280 unsigned long nr_saved_scan[NR_LRU_LISTS];
283 struct zone {
284 /* Fields commonly accessed by the page allocator */
286 /* zone watermarks, access with *_wmark_pages(zone) macros */
287 unsigned long watermark[NR_WMARK];
290 * When free pages are below this point, additional steps are taken
291 * when reading the number of free pages to avoid per-cpu counter
292 * drift allowing watermarks to be breached
294 unsigned long percpu_drift_mark;
297 * We don't know if the memory that we're going to allocate will be freeable
298 * or/and it will be released eventually, so to avoid totally wasting several
299 * GB of ram we must reserve some of the lower zone memory (otherwise we risk
300 * to run OOM on the lower zones despite there's tons of freeable ram
301 * on the higher zones). This array is recalculated at runtime if the
302 * sysctl_lowmem_reserve_ratio sysctl changes.
304 unsigned long lowmem_reserve[MAX_NR_ZONES];
306 #ifdef CONFIG_NUMA
307 int node;
309 * zone reclaim becomes active if more unmapped pages exist.
311 unsigned long min_unmapped_pages;
312 unsigned long min_slab_pages;
313 #endif
314 struct per_cpu_pageset __percpu *pageset;
316 * free areas of different sizes
318 spinlock_t lock;
319 int all_unreclaimable; /* All pages pinned */
320 #ifdef CONFIG_MEMORY_HOTPLUG
321 /* see spanned/present_pages for more description */
322 seqlock_t span_seqlock;
323 #endif
324 struct free_area free_area[MAX_ORDER];
326 #ifndef CONFIG_SPARSEMEM
328 * Flags for a pageblock_nr_pages block. See pageblock-flags.h.
329 * In SPARSEMEM, this map is stored in struct mem_section
331 unsigned long *pageblock_flags;
332 #endif /* CONFIG_SPARSEMEM */
334 #ifdef CONFIG_COMPACTION
336 * On compaction failure, 1<<compact_defer_shift compactions
337 * are skipped before trying again. The number attempted since
338 * last failure is tracked with compact_considered.
340 unsigned int compact_considered;
341 unsigned int compact_defer_shift;
342 #endif
344 ZONE_PADDING(_pad1_)
346 /* Fields commonly accessed by the page reclaim scanner */
347 spinlock_t lru_lock;
348 struct zone_lru {
349 struct list_head list;
350 } lru[NR_LRU_LISTS];
352 struct zone_reclaim_stat reclaim_stat;
354 unsigned long pages_scanned; /* since last reclaim */
355 unsigned long flags; /* zone flags, see below */
357 /* Zone statistics */
358 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
361 * The target ratio of ACTIVE_ANON to INACTIVE_ANON pages on
362 * this zone's LRU. Maintained by the pageout code.
364 unsigned int inactive_ratio;
367 ZONE_PADDING(_pad2_)
368 /* Rarely used or read-mostly fields */
371 * wait_table -- the array holding the hash table
372 * wait_table_hash_nr_entries -- the size of the hash table array
373 * wait_table_bits -- wait_table_size == (1 << wait_table_bits)
375 * The purpose of all these is to keep track of the people
376 * waiting for a page to become available and make them
377 * runnable again when possible. The trouble is that this
378 * consumes a lot of space, especially when so few things
379 * wait on pages at a given time. So instead of using
380 * per-page waitqueues, we use a waitqueue hash table.
382 * The bucket discipline is to sleep on the same queue when
383 * colliding and wake all in that wait queue when removing.
384 * When something wakes, it must check to be sure its page is
385 * truly available, a la thundering herd. The cost of a
386 * collision is great, but given the expected load of the
387 * table, they should be so rare as to be outweighed by the
388 * benefits from the saved space.
390 * __wait_on_page_locked() and unlock_page() in mm/filemap.c, are the
391 * primary users of these fields, and in mm/page_alloc.c
392 * free_area_init_core() performs the initialization of them.
394 wait_queue_head_t * wait_table;
395 unsigned long wait_table_hash_nr_entries;
396 unsigned long wait_table_bits;
399 * Discontig memory support fields.
401 struct pglist_data *zone_pgdat;
402 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
403 unsigned long zone_start_pfn;
406 * zone_start_pfn, spanned_pages and present_pages are all
407 * protected by span_seqlock. It is a seqlock because it has
408 * to be read outside of zone->lock, and it is done in the main
409 * allocator path. But, it is written quite infrequently.
411 * The lock is declared along with zone->lock because it is
412 * frequently read in proximity to zone->lock. It's good to
413 * give them a chance of being in the same cacheline.
415 unsigned long spanned_pages; /* total size, including holes */
416 unsigned long present_pages; /* amount of memory (excluding holes) */
419 * rarely used fields:
421 const char *name;
422 } ____cacheline_internodealigned_in_smp;
424 typedef enum {
425 ZONE_RECLAIM_LOCKED, /* prevents concurrent reclaim */
426 ZONE_OOM_LOCKED, /* zone is in OOM killer zonelist */
427 ZONE_CONGESTED, /* zone has many dirty pages backed by
428 * a congested BDI
430 } zone_flags_t;
432 static inline void zone_set_flag(struct zone *zone, zone_flags_t flag)
434 set_bit(flag, &zone->flags);
437 static inline int zone_test_and_set_flag(struct zone *zone, zone_flags_t flag)
439 return test_and_set_bit(flag, &zone->flags);
442 static inline void zone_clear_flag(struct zone *zone, zone_flags_t flag)
444 clear_bit(flag, &zone->flags);
447 static inline int zone_is_reclaim_congested(const struct zone *zone)
449 return test_bit(ZONE_CONGESTED, &zone->flags);
452 static inline int zone_is_reclaim_locked(const struct zone *zone)
454 return test_bit(ZONE_RECLAIM_LOCKED, &zone->flags);
457 static inline int zone_is_oom_locked(const struct zone *zone)
459 return test_bit(ZONE_OOM_LOCKED, &zone->flags);
463 * The "priority" of VM scanning is how much of the queues we will scan in one
464 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
465 * queues ("queue_length >> 12") during an aging round.
467 #define DEF_PRIORITY 12
469 /* Maximum number of zones on a zonelist */
470 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
472 #ifdef CONFIG_NUMA
475 * The NUMA zonelists are doubled becausse we need zonelists that restrict the
476 * allocations to a single node for GFP_THISNODE.
478 * [0] : Zonelist with fallback
479 * [1] : No fallback (GFP_THISNODE)
481 #define MAX_ZONELISTS 2
485 * We cache key information from each zonelist for smaller cache
486 * footprint when scanning for free pages in get_page_from_freelist().
488 * 1) The BITMAP fullzones tracks which zones in a zonelist have come
489 * up short of free memory since the last time (last_fullzone_zap)
490 * we zero'd fullzones.
491 * 2) The array z_to_n[] maps each zone in the zonelist to its node
492 * id, so that we can efficiently evaluate whether that node is
493 * set in the current tasks mems_allowed.
495 * Both fullzones and z_to_n[] are one-to-one with the zonelist,
496 * indexed by a zones offset in the zonelist zones[] array.
498 * The get_page_from_freelist() routine does two scans. During the
499 * first scan, we skip zones whose corresponding bit in 'fullzones'
500 * is set or whose corresponding node in current->mems_allowed (which
501 * comes from cpusets) is not set. During the second scan, we bypass
502 * this zonelist_cache, to ensure we look methodically at each zone.
504 * Once per second, we zero out (zap) fullzones, forcing us to
505 * reconsider nodes that might have regained more free memory.
506 * The field last_full_zap is the time we last zapped fullzones.
508 * This mechanism reduces the amount of time we waste repeatedly
509 * reexaming zones for free memory when they just came up low on
510 * memory momentarilly ago.
512 * The zonelist_cache struct members logically belong in struct
513 * zonelist. However, the mempolicy zonelists constructed for
514 * MPOL_BIND are intentionally variable length (and usually much
515 * shorter). A general purpose mechanism for handling structs with
516 * multiple variable length members is more mechanism than we want
517 * here. We resort to some special case hackery instead.
519 * The MPOL_BIND zonelists don't need this zonelist_cache (in good
520 * part because they are shorter), so we put the fixed length stuff
521 * at the front of the zonelist struct, ending in a variable length
522 * zones[], as is needed by MPOL_BIND.
524 * Then we put the optional zonelist cache on the end of the zonelist
525 * struct. This optional stuff is found by a 'zlcache_ptr' pointer in
526 * the fixed length portion at the front of the struct. This pointer
527 * both enables us to find the zonelist cache, and in the case of
528 * MPOL_BIND zonelists, (which will just set the zlcache_ptr to NULL)
529 * to know that the zonelist cache is not there.
531 * The end result is that struct zonelists come in two flavors:
532 * 1) The full, fixed length version, shown below, and
533 * 2) The custom zonelists for MPOL_BIND.
534 * The custom MPOL_BIND zonelists have a NULL zlcache_ptr and no zlcache.
536 * Even though there may be multiple CPU cores on a node modifying
537 * fullzones or last_full_zap in the same zonelist_cache at the same
538 * time, we don't lock it. This is just hint data - if it is wrong now
539 * and then, the allocator will still function, perhaps a bit slower.
543 struct zonelist_cache {
544 unsigned short z_to_n[MAX_ZONES_PER_ZONELIST]; /* zone->nid */
545 DECLARE_BITMAP(fullzones, MAX_ZONES_PER_ZONELIST); /* zone full? */
546 unsigned long last_full_zap; /* when last zap'd (jiffies) */
548 #else
549 #define MAX_ZONELISTS 1
550 struct zonelist_cache;
551 #endif
554 * This struct contains information about a zone in a zonelist. It is stored
555 * here to avoid dereferences into large structures and lookups of tables
557 struct zoneref {
558 struct zone *zone; /* Pointer to actual zone */
559 int zone_idx; /* zone_idx(zoneref->zone) */
563 * One allocation request operates on a zonelist. A zonelist
564 * is a list of zones, the first one is the 'goal' of the
565 * allocation, the other zones are fallback zones, in decreasing
566 * priority.
568 * If zlcache_ptr is not NULL, then it is just the address of zlcache,
569 * as explained above. If zlcache_ptr is NULL, there is no zlcache.
571 * To speed the reading of the zonelist, the zonerefs contain the zone index
572 * of the entry being read. Helper functions to access information given
573 * a struct zoneref are
575 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs
576 * zonelist_zone_idx() - Return the index of the zone for an entry
577 * zonelist_node_idx() - Return the index of the node for an entry
579 struct zonelist {
580 struct zonelist_cache *zlcache_ptr; // NULL or &zlcache
581 struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1];
582 #ifdef CONFIG_NUMA
583 struct zonelist_cache zlcache; // optional ...
584 #endif
587 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
588 struct node_active_region {
589 unsigned long start_pfn;
590 unsigned long end_pfn;
591 int nid;
593 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
595 #ifndef CONFIG_DISCONTIGMEM
596 /* The array of struct pages - for discontigmem use pgdat->lmem_map */
597 extern struct page *mem_map;
598 #endif
601 * The pg_data_t structure is used in machines with CONFIG_DISCONTIGMEM
602 * (mostly NUMA machines?) to denote a higher-level memory zone than the
603 * zone denotes.
605 * On NUMA machines, each NUMA node would have a pg_data_t to describe
606 * it's memory layout.
608 * Memory statistics and page replacement data structures are maintained on a
609 * per-zone basis.
611 struct bootmem_data;
612 typedef struct pglist_data {
613 struct zone node_zones[MAX_NR_ZONES];
614 struct zonelist node_zonelists[MAX_ZONELISTS];
615 int nr_zones;
616 #ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */
617 struct page *node_mem_map;
618 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
619 struct page_cgroup *node_page_cgroup;
620 #endif
621 #endif
622 #ifndef CONFIG_NO_BOOTMEM
623 struct bootmem_data *bdata;
624 #endif
625 #ifdef CONFIG_MEMORY_HOTPLUG
627 * Must be held any time you expect node_start_pfn, node_present_pages
628 * or node_spanned_pages stay constant. Holding this will also
629 * guarantee that any pfn_valid() stays that way.
631 * Nests above zone->lock and zone->size_seqlock.
633 spinlock_t node_size_lock;
634 #endif
635 unsigned long node_start_pfn;
636 unsigned long node_present_pages; /* total number of physical pages */
637 unsigned long node_spanned_pages; /* total size of physical page
638 range, including holes */
639 int node_id;
640 wait_queue_head_t kswapd_wait;
641 struct task_struct *kswapd;
642 int kswapd_max_order;
643 enum zone_type classzone_idx;
644 } pg_data_t;
646 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
647 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
648 #ifdef CONFIG_FLAT_NODE_MEM_MAP
649 #define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr))
650 #else
651 #define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr))
652 #endif
653 #define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr))
655 #include <linux/memory_hotplug.h>
657 extern struct mutex zonelists_mutex;
658 void build_all_zonelists(void *data);
659 void wakeup_kswapd(struct zone *zone, int order, enum zone_type classzone_idx);
660 bool zone_watermark_ok(struct zone *z, int order, unsigned long mark,
661 int classzone_idx, int alloc_flags);
662 bool zone_watermark_ok_safe(struct zone *z, int order, unsigned long mark,
663 int classzone_idx, int alloc_flags);
664 enum memmap_context {
665 MEMMAP_EARLY,
666 MEMMAP_HOTPLUG,
668 extern int init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
669 unsigned long size,
670 enum memmap_context context);
672 #ifdef CONFIG_HAVE_MEMORY_PRESENT
673 void memory_present(int nid, unsigned long start, unsigned long end);
674 #else
675 static inline void memory_present(int nid, unsigned long start, unsigned long end) {}
676 #endif
678 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
679 int local_memory_node(int node_id);
680 #else
681 static inline int local_memory_node(int node_id) { return node_id; };
682 #endif
684 #ifdef CONFIG_NEED_NODE_MEMMAP_SIZE
685 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
686 #endif
689 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
691 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones)
693 static inline int populated_zone(struct zone *zone)
695 return (!!zone->present_pages);
698 extern int movable_zone;
700 static inline int zone_movable_is_highmem(void)
702 #if defined(CONFIG_HIGHMEM) && defined(CONFIG_ARCH_POPULATES_NODE_MAP)
703 return movable_zone == ZONE_HIGHMEM;
704 #else
705 return 0;
706 #endif
709 static inline int is_highmem_idx(enum zone_type idx)
711 #ifdef CONFIG_HIGHMEM
712 return (idx == ZONE_HIGHMEM ||
713 (idx == ZONE_MOVABLE && zone_movable_is_highmem()));
714 #else
715 return 0;
716 #endif
719 static inline int is_normal_idx(enum zone_type idx)
721 return (idx == ZONE_NORMAL);
725 * is_highmem - helper function to quickly check if a struct zone is a
726 * highmem zone or not. This is an attempt to keep references
727 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
728 * @zone - pointer to struct zone variable
730 static inline int is_highmem(struct zone *zone)
732 #ifdef CONFIG_HIGHMEM
733 int zone_off = (char *)zone - (char *)zone->zone_pgdat->node_zones;
734 return zone_off == ZONE_HIGHMEM * sizeof(*zone) ||
735 (zone_off == ZONE_MOVABLE * sizeof(*zone) &&
736 zone_movable_is_highmem());
737 #else
738 return 0;
739 #endif
742 static inline int is_normal(struct zone *zone)
744 return zone == zone->zone_pgdat->node_zones + ZONE_NORMAL;
747 static inline int is_dma32(struct zone *zone)
749 #ifdef CONFIG_ZONE_DMA32
750 return zone == zone->zone_pgdat->node_zones + ZONE_DMA32;
751 #else
752 return 0;
753 #endif
756 static inline int is_dma(struct zone *zone)
758 #ifdef CONFIG_ZONE_DMA
759 return zone == zone->zone_pgdat->node_zones + ZONE_DMA;
760 #else
761 return 0;
762 #endif
765 /* These two functions are used to setup the per zone pages min values */
766 struct ctl_table;
767 int min_free_kbytes_sysctl_handler(struct ctl_table *, int,
768 void __user *, size_t *, loff_t *);
769 extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1];
770 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int,
771 void __user *, size_t *, loff_t *);
772 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int,
773 void __user *, size_t *, loff_t *);
774 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int,
775 void __user *, size_t *, loff_t *);
776 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int,
777 void __user *, size_t *, loff_t *);
779 extern int numa_zonelist_order_handler(struct ctl_table *, int,
780 void __user *, size_t *, loff_t *);
781 extern char numa_zonelist_order[];
782 #define NUMA_ZONELIST_ORDER_LEN 16 /* string buffer size */
784 #ifndef CONFIG_NEED_MULTIPLE_NODES
786 extern struct pglist_data contig_page_data;
787 #define NODE_DATA(nid) (&contig_page_data)
788 #define NODE_MEM_MAP(nid) mem_map
790 #else /* CONFIG_NEED_MULTIPLE_NODES */
792 #include <asm/mmzone.h>
794 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
796 extern struct pglist_data *first_online_pgdat(void);
797 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
798 extern struct zone *next_zone(struct zone *zone);
801 * for_each_online_pgdat - helper macro to iterate over all online nodes
802 * @pgdat - pointer to a pg_data_t variable
804 #define for_each_online_pgdat(pgdat) \
805 for (pgdat = first_online_pgdat(); \
806 pgdat; \
807 pgdat = next_online_pgdat(pgdat))
809 * for_each_zone - helper macro to iterate over all memory zones
810 * @zone - pointer to struct zone variable
812 * The user only needs to declare the zone variable, for_each_zone
813 * fills it in.
815 #define for_each_zone(zone) \
816 for (zone = (first_online_pgdat())->node_zones; \
817 zone; \
818 zone = next_zone(zone))
820 #define for_each_populated_zone(zone) \
821 for (zone = (first_online_pgdat())->node_zones; \
822 zone; \
823 zone = next_zone(zone)) \
824 if (!populated_zone(zone)) \
825 ; /* do nothing */ \
826 else
828 static inline struct zone *zonelist_zone(struct zoneref *zoneref)
830 return zoneref->zone;
833 static inline int zonelist_zone_idx(struct zoneref *zoneref)
835 return zoneref->zone_idx;
838 static inline int zonelist_node_idx(struct zoneref *zoneref)
840 #ifdef CONFIG_NUMA
841 /* zone_to_nid not available in this context */
842 return zoneref->zone->node;
843 #else
844 return 0;
845 #endif /* CONFIG_NUMA */
849 * 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
850 * @z - The cursor used as a starting point for the search
851 * @highest_zoneidx - The zone index of the highest zone to return
852 * @nodes - An optional nodemask to filter the zonelist with
853 * @zone - The first suitable zone found is returned via this parameter
855 * This function returns the next zone at or below a given zone index that is
856 * within the allowed nodemask using a cursor as the starting point for the
857 * search. The zoneref returned is a cursor that represents the current zone
858 * being examined. It should be advanced by one before calling
859 * next_zones_zonelist again.
861 struct zoneref *next_zones_zonelist(struct zoneref *z,
862 enum zone_type highest_zoneidx,
863 nodemask_t *nodes,
864 struct zone **zone);
867 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
868 * @zonelist - The zonelist to search for a suitable zone
869 * @highest_zoneidx - The zone index of the highest zone to return
870 * @nodes - An optional nodemask to filter the zonelist with
871 * @zone - The first suitable zone found is returned via this parameter
873 * This function returns the first zone at or below a given zone index that is
874 * within the allowed nodemask. The zoneref returned is a cursor that can be
875 * used to iterate the zonelist with next_zones_zonelist by advancing it by
876 * one before calling.
878 static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
879 enum zone_type highest_zoneidx,
880 nodemask_t *nodes,
881 struct zone **zone)
883 return next_zones_zonelist(zonelist->_zonerefs, highest_zoneidx, nodes,
884 zone);
888 * 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
889 * @zone - The current zone in the iterator
890 * @z - The current pointer within zonelist->zones being iterated
891 * @zlist - The zonelist being iterated
892 * @highidx - The zone index of the highest zone to return
893 * @nodemask - Nodemask allowed by the allocator
895 * This iterator iterates though all zones at or below a given zone index and
896 * within a given nodemask
898 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
899 for (z = first_zones_zonelist(zlist, highidx, nodemask, &zone); \
900 zone; \
901 z = next_zones_zonelist(++z, highidx, nodemask, &zone)) \
904 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
905 * @zone - The current zone in the iterator
906 * @z - The current pointer within zonelist->zones being iterated
907 * @zlist - The zonelist being iterated
908 * @highidx - The zone index of the highest zone to return
910 * This iterator iterates though all zones at or below a given zone index.
912 #define for_each_zone_zonelist(zone, z, zlist, highidx) \
913 for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL)
915 #ifdef CONFIG_SPARSEMEM
916 #include <asm/sparsemem.h>
917 #endif
919 #if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \
920 !defined(CONFIG_ARCH_POPULATES_NODE_MAP)
921 static inline unsigned long early_pfn_to_nid(unsigned long pfn)
923 return 0;
925 #endif
927 #ifdef CONFIG_FLATMEM
928 #define pfn_to_nid(pfn) (0)
929 #endif
931 #define pfn_to_section_nr(pfn) ((pfn) >> PFN_SECTION_SHIFT)
932 #define section_nr_to_pfn(sec) ((sec) << PFN_SECTION_SHIFT)
934 #ifdef CONFIG_SPARSEMEM
937 * SECTION_SHIFT #bits space required to store a section #
939 * PA_SECTION_SHIFT physical address to/from section number
940 * PFN_SECTION_SHIFT pfn to/from section number
942 #define SECTIONS_SHIFT (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS)
944 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS)
945 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
947 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT)
949 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT)
950 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1))
952 #define SECTION_BLOCKFLAGS_BITS \
953 ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS)
955 #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
956 #error Allocator MAX_ORDER exceeds SECTION_SIZE
957 #endif
959 struct page;
960 struct page_cgroup;
961 struct mem_section {
963 * This is, logically, a pointer to an array of struct
964 * pages. However, it is stored with some other magic.
965 * (see sparse.c::sparse_init_one_section())
967 * Additionally during early boot we encode node id of
968 * the location of the section here to guide allocation.
969 * (see sparse.c::memory_present())
971 * Making it a UL at least makes someone do a cast
972 * before using it wrong.
974 unsigned long section_mem_map;
976 /* See declaration of similar field in struct zone */
977 unsigned long *pageblock_flags;
978 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
980 * If !SPARSEMEM, pgdat doesn't have page_cgroup pointer. We use
981 * section. (see memcontrol.h/page_cgroup.h about this.)
983 struct page_cgroup *page_cgroup;
984 unsigned long pad;
985 #endif
988 #ifdef CONFIG_SPARSEMEM_EXTREME
989 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section))
990 #else
991 #define SECTIONS_PER_ROOT 1
992 #endif
994 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
995 #define NR_SECTION_ROOTS DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT)
996 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1)
998 #ifdef CONFIG_SPARSEMEM_EXTREME
999 extern struct mem_section *mem_section[NR_SECTION_ROOTS];
1000 #else
1001 extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
1002 #endif
1004 static inline struct mem_section *__nr_to_section(unsigned long nr)
1006 if (!mem_section[SECTION_NR_TO_ROOT(nr)])
1007 return NULL;
1008 return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];
1010 extern int __section_nr(struct mem_section* ms);
1011 extern unsigned long usemap_size(void);
1014 * We use the lower bits of the mem_map pointer to store
1015 * a little bit of information. There should be at least
1016 * 3 bits here due to 32-bit alignment.
1018 #define SECTION_MARKED_PRESENT (1UL<<0)
1019 #define SECTION_HAS_MEM_MAP (1UL<<1)
1020 #define SECTION_MAP_LAST_BIT (1UL<<2)
1021 #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1))
1022 #define SECTION_NID_SHIFT 2
1024 static inline struct page *__section_mem_map_addr(struct mem_section *section)
1026 unsigned long map = section->section_mem_map;
1027 map &= SECTION_MAP_MASK;
1028 return (struct page *)map;
1031 static inline int present_section(struct mem_section *section)
1033 return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
1036 static inline int present_section_nr(unsigned long nr)
1038 return present_section(__nr_to_section(nr));
1041 static inline int valid_section(struct mem_section *section)
1043 return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
1046 static inline int valid_section_nr(unsigned long nr)
1048 return valid_section(__nr_to_section(nr));
1051 static inline struct mem_section *__pfn_to_section(unsigned long pfn)
1053 return __nr_to_section(pfn_to_section_nr(pfn));
1056 static inline int pfn_valid(unsigned long pfn)
1058 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
1059 return 0;
1060 return valid_section(__nr_to_section(pfn_to_section_nr(pfn)));
1063 static inline int pfn_present(unsigned long pfn)
1065 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
1066 return 0;
1067 return present_section(__nr_to_section(pfn_to_section_nr(pfn)));
1071 * These are _only_ used during initialisation, therefore they
1072 * can use __initdata ... They could have names to indicate
1073 * this restriction.
1075 #ifdef CONFIG_NUMA
1076 #define pfn_to_nid(pfn) \
1077 ({ \
1078 unsigned long __pfn_to_nid_pfn = (pfn); \
1079 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \
1081 #else
1082 #define pfn_to_nid(pfn) (0)
1083 #endif
1085 #define early_pfn_valid(pfn) pfn_valid(pfn)
1086 void sparse_init(void);
1087 #else
1088 #define sparse_init() do {} while (0)
1089 #define sparse_index_init(_sec, _nid) do {} while (0)
1090 #endif /* CONFIG_SPARSEMEM */
1092 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1093 bool early_pfn_in_nid(unsigned long pfn, int nid);
1094 #else
1095 #define early_pfn_in_nid(pfn, nid) (1)
1096 #endif
1098 #ifndef early_pfn_valid
1099 #define early_pfn_valid(pfn) (1)
1100 #endif
1102 void memory_present(int nid, unsigned long start, unsigned long end);
1103 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
1106 * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we
1107 * need to check pfn validility within that MAX_ORDER_NR_PAGES block.
1108 * pfn_valid_within() should be used in this case; we optimise this away
1109 * when we have no holes within a MAX_ORDER_NR_PAGES block.
1111 #ifdef CONFIG_HOLES_IN_ZONE
1112 #define pfn_valid_within(pfn) pfn_valid(pfn)
1113 #else
1114 #define pfn_valid_within(pfn) (1)
1115 #endif
1117 #ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
1119 * pfn_valid() is meant to be able to tell if a given PFN has valid memmap
1120 * associated with it or not. In FLATMEM, it is expected that holes always
1121 * have valid memmap as long as there is valid PFNs either side of the hole.
1122 * In SPARSEMEM, it is assumed that a valid section has a memmap for the
1123 * entire section.
1125 * However, an ARM, and maybe other embedded architectures in the future
1126 * free memmap backing holes to save memory on the assumption the memmap is
1127 * never used. The page_zone linkages are then broken even though pfn_valid()
1128 * returns true. A walker of the full memmap must then do this additional
1129 * check to ensure the memmap they are looking at is sane by making sure
1130 * the zone and PFN linkages are still valid. This is expensive, but walkers
1131 * of the full memmap are extremely rare.
1133 int memmap_valid_within(unsigned long pfn,
1134 struct page *page, struct zone *zone);
1135 #else
1136 static inline int memmap_valid_within(unsigned long pfn,
1137 struct page *page, struct zone *zone)
1139 return 1;
1141 #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */
1143 #endif /* !__GENERATING_BOUNDS.H */
1144 #endif /* !__ASSEMBLY__ */
1145 #endif /* _LINUX_MMZONE_H */