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[linux-2.6/mini2440.git] / include / linux / mmzone.h
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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 <linux/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_RESERVE 3
42 #define MIGRATE_ISOLATE 4 /* can't allocate from here */
43 #define MIGRATE_TYPES 5
45 #define for_each_migratetype_order(order, type) \
46 for (order = 0; order < MAX_ORDER; order++) \
47 for (type = 0; type < MIGRATE_TYPES; type++)
49 extern int page_group_by_mobility_disabled;
51 static inline int get_pageblock_migratetype(struct page *page)
53 if (unlikely(page_group_by_mobility_disabled))
54 return MIGRATE_UNMOVABLE;
56 return get_pageblock_flags_group(page, PB_migrate, PB_migrate_end);
59 struct free_area {
60 struct list_head free_list[MIGRATE_TYPES];
61 unsigned long nr_free;
64 struct pglist_data;
67 * zone->lock and zone->lru_lock are two of the hottest locks in the kernel.
68 * So add a wild amount of padding here to ensure that they fall into separate
69 * cachelines. There are very few zone structures in the machine, so space
70 * consumption is not a concern here.
72 #if defined(CONFIG_SMP)
73 struct zone_padding {
74 char x[0];
75 } ____cacheline_internodealigned_in_smp;
76 #define ZONE_PADDING(name) struct zone_padding name;
77 #else
78 #define ZONE_PADDING(name)
79 #endif
81 enum zone_stat_item {
82 /* First 128 byte cacheline (assuming 64 bit words) */
83 NR_FREE_PAGES,
84 NR_INACTIVE,
85 NR_ACTIVE,
86 NR_ANON_PAGES, /* Mapped anonymous pages */
87 NR_FILE_MAPPED, /* pagecache pages mapped into pagetables.
88 only modified from process context */
89 NR_FILE_PAGES,
90 NR_FILE_DIRTY,
91 NR_WRITEBACK,
92 /* Second 128 byte cacheline */
93 NR_SLAB_RECLAIMABLE,
94 NR_SLAB_UNRECLAIMABLE,
95 NR_PAGETABLE, /* used for pagetables */
96 NR_UNSTABLE_NFS, /* NFS unstable pages */
97 NR_BOUNCE,
98 NR_VMSCAN_WRITE,
99 NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */
100 #ifdef CONFIG_NUMA
101 NUMA_HIT, /* allocated in intended node */
102 NUMA_MISS, /* allocated in non intended node */
103 NUMA_FOREIGN, /* was intended here, hit elsewhere */
104 NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */
105 NUMA_LOCAL, /* allocation from local node */
106 NUMA_OTHER, /* allocation from other node */
107 #endif
108 NR_VM_ZONE_STAT_ITEMS };
110 struct per_cpu_pages {
111 int count; /* number of pages in the list */
112 int high; /* high watermark, emptying needed */
113 int batch; /* chunk size for buddy add/remove */
114 struct list_head list; /* the list of pages */
117 struct per_cpu_pageset {
118 struct per_cpu_pages pcp;
119 #ifdef CONFIG_NUMA
120 s8 expire;
121 #endif
122 #ifdef CONFIG_SMP
123 s8 stat_threshold;
124 s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS];
125 #endif
126 } ____cacheline_aligned_in_smp;
128 #ifdef CONFIG_NUMA
129 #define zone_pcp(__z, __cpu) ((__z)->pageset[(__cpu)])
130 #else
131 #define zone_pcp(__z, __cpu) (&(__z)->pageset[(__cpu)])
132 #endif
134 #endif /* !__GENERATING_BOUNDS.H */
136 enum zone_type {
137 #ifdef CONFIG_ZONE_DMA
139 * ZONE_DMA is used when there are devices that are not able
140 * to do DMA to all of addressable memory (ZONE_NORMAL). Then we
141 * carve out the portion of memory that is needed for these devices.
142 * The range is arch specific.
144 * Some examples
146 * Architecture Limit
147 * ---------------------------
148 * parisc, ia64, sparc <4G
149 * s390 <2G
150 * arm Various
151 * alpha Unlimited or 0-16MB.
153 * i386, x86_64 and multiple other arches
154 * <16M.
156 ZONE_DMA,
157 #endif
158 #ifdef CONFIG_ZONE_DMA32
160 * x86_64 needs two ZONE_DMAs because it supports devices that are
161 * only able to do DMA to the lower 16M but also 32 bit devices that
162 * can only do DMA areas below 4G.
164 ZONE_DMA32,
165 #endif
167 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be
168 * performed on pages in ZONE_NORMAL if the DMA devices support
169 * transfers to all addressable memory.
171 ZONE_NORMAL,
172 #ifdef CONFIG_HIGHMEM
174 * A memory area that is only addressable by the kernel through
175 * mapping portions into its own address space. This is for example
176 * used by i386 to allow the kernel to address the memory beyond
177 * 900MB. The kernel will set up special mappings (page
178 * table entries on i386) for each page that the kernel needs to
179 * access.
181 ZONE_HIGHMEM,
182 #endif
183 ZONE_MOVABLE,
184 __MAX_NR_ZONES
187 #ifndef __GENERATING_BOUNDS_H
190 * When a memory allocation must conform to specific limitations (such
191 * as being suitable for DMA) the caller will pass in hints to the
192 * allocator in the gfp_mask, in the zone modifier bits. These bits
193 * are used to select a priority ordered list of memory zones which
194 * match the requested limits. See gfp_zone() in include/linux/gfp.h
197 #if MAX_NR_ZONES < 2
198 #define ZONES_SHIFT 0
199 #elif MAX_NR_ZONES <= 2
200 #define ZONES_SHIFT 1
201 #elif MAX_NR_ZONES <= 4
202 #define ZONES_SHIFT 2
203 #else
204 #error ZONES_SHIFT -- too many zones configured adjust calculation
205 #endif
207 struct zone {
208 /* Fields commonly accessed by the page allocator */
209 unsigned long pages_min, pages_low, pages_high;
211 * We don't know if the memory that we're going to allocate will be freeable
212 * or/and it will be released eventually, so to avoid totally wasting several
213 * GB of ram we must reserve some of the lower zone memory (otherwise we risk
214 * to run OOM on the lower zones despite there's tons of freeable ram
215 * on the higher zones). This array is recalculated at runtime if the
216 * sysctl_lowmem_reserve_ratio sysctl changes.
218 unsigned long lowmem_reserve[MAX_NR_ZONES];
220 #ifdef CONFIG_NUMA
221 int node;
223 * zone reclaim becomes active if more unmapped pages exist.
225 unsigned long min_unmapped_pages;
226 unsigned long min_slab_pages;
227 struct per_cpu_pageset *pageset[NR_CPUS];
228 #else
229 struct per_cpu_pageset pageset[NR_CPUS];
230 #endif
232 * free areas of different sizes
234 spinlock_t lock;
235 #ifdef CONFIG_MEMORY_HOTPLUG
236 /* see spanned/present_pages for more description */
237 seqlock_t span_seqlock;
238 #endif
239 struct free_area free_area[MAX_ORDER];
241 #ifndef CONFIG_SPARSEMEM
243 * Flags for a pageblock_nr_pages block. See pageblock-flags.h.
244 * In SPARSEMEM, this map is stored in struct mem_section
246 unsigned long *pageblock_flags;
247 #endif /* CONFIG_SPARSEMEM */
250 ZONE_PADDING(_pad1_)
252 /* Fields commonly accessed by the page reclaim scanner */
253 spinlock_t lru_lock;
254 struct list_head active_list;
255 struct list_head inactive_list;
256 unsigned long nr_scan_active;
257 unsigned long nr_scan_inactive;
258 unsigned long pages_scanned; /* since last reclaim */
259 unsigned long flags; /* zone flags, see below */
261 /* Zone statistics */
262 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
265 * prev_priority holds the scanning priority for this zone. It is
266 * defined as the scanning priority at which we achieved our reclaim
267 * target at the previous try_to_free_pages() or balance_pgdat()
268 * invokation.
270 * We use prev_priority as a measure of how much stress page reclaim is
271 * under - it drives the swappiness decision: whether to unmap mapped
272 * pages.
274 * Access to both this field is quite racy even on uniprocessor. But
275 * it is expected to average out OK.
277 int prev_priority;
280 ZONE_PADDING(_pad2_)
281 /* Rarely used or read-mostly fields */
284 * wait_table -- the array holding the hash table
285 * wait_table_hash_nr_entries -- the size of the hash table array
286 * wait_table_bits -- wait_table_size == (1 << wait_table_bits)
288 * The purpose of all these is to keep track of the people
289 * waiting for a page to become available and make them
290 * runnable again when possible. The trouble is that this
291 * consumes a lot of space, especially when so few things
292 * wait on pages at a given time. So instead of using
293 * per-page waitqueues, we use a waitqueue hash table.
295 * The bucket discipline is to sleep on the same queue when
296 * colliding and wake all in that wait queue when removing.
297 * When something wakes, it must check to be sure its page is
298 * truly available, a la thundering herd. The cost of a
299 * collision is great, but given the expected load of the
300 * table, they should be so rare as to be outweighed by the
301 * benefits from the saved space.
303 * __wait_on_page_locked() and unlock_page() in mm/filemap.c, are the
304 * primary users of these fields, and in mm/page_alloc.c
305 * free_area_init_core() performs the initialization of them.
307 wait_queue_head_t * wait_table;
308 unsigned long wait_table_hash_nr_entries;
309 unsigned long wait_table_bits;
312 * Discontig memory support fields.
314 struct pglist_data *zone_pgdat;
315 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
316 unsigned long zone_start_pfn;
319 * zone_start_pfn, spanned_pages and present_pages are all
320 * protected by span_seqlock. It is a seqlock because it has
321 * to be read outside of zone->lock, and it is done in the main
322 * allocator path. But, it is written quite infrequently.
324 * The lock is declared along with zone->lock because it is
325 * frequently read in proximity to zone->lock. It's good to
326 * give them a chance of being in the same cacheline.
328 unsigned long spanned_pages; /* total size, including holes */
329 unsigned long present_pages; /* amount of memory (excluding holes) */
332 * rarely used fields:
334 const char *name;
335 } ____cacheline_internodealigned_in_smp;
337 typedef enum {
338 ZONE_ALL_UNRECLAIMABLE, /* all pages pinned */
339 ZONE_RECLAIM_LOCKED, /* prevents concurrent reclaim */
340 ZONE_OOM_LOCKED, /* zone is in OOM killer zonelist */
341 } zone_flags_t;
343 static inline void zone_set_flag(struct zone *zone, zone_flags_t flag)
345 set_bit(flag, &zone->flags);
348 static inline int zone_test_and_set_flag(struct zone *zone, zone_flags_t flag)
350 return test_and_set_bit(flag, &zone->flags);
353 static inline void zone_clear_flag(struct zone *zone, zone_flags_t flag)
355 clear_bit(flag, &zone->flags);
358 static inline int zone_is_all_unreclaimable(const struct zone *zone)
360 return test_bit(ZONE_ALL_UNRECLAIMABLE, &zone->flags);
363 static inline int zone_is_reclaim_locked(const struct zone *zone)
365 return test_bit(ZONE_RECLAIM_LOCKED, &zone->flags);
368 static inline int zone_is_oom_locked(const struct zone *zone)
370 return test_bit(ZONE_OOM_LOCKED, &zone->flags);
374 * The "priority" of VM scanning is how much of the queues we will scan in one
375 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
376 * queues ("queue_length >> 12") during an aging round.
378 #define DEF_PRIORITY 12
380 /* Maximum number of zones on a zonelist */
381 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
383 #ifdef CONFIG_NUMA
386 * The NUMA zonelists are doubled becausse we need zonelists that restrict the
387 * allocations to a single node for GFP_THISNODE.
389 * [0] : Zonelist with fallback
390 * [1] : No fallback (GFP_THISNODE)
392 #define MAX_ZONELISTS 2
396 * We cache key information from each zonelist for smaller cache
397 * footprint when scanning for free pages in get_page_from_freelist().
399 * 1) The BITMAP fullzones tracks which zones in a zonelist have come
400 * up short of free memory since the last time (last_fullzone_zap)
401 * we zero'd fullzones.
402 * 2) The array z_to_n[] maps each zone in the zonelist to its node
403 * id, so that we can efficiently evaluate whether that node is
404 * set in the current tasks mems_allowed.
406 * Both fullzones and z_to_n[] are one-to-one with the zonelist,
407 * indexed by a zones offset in the zonelist zones[] array.
409 * The get_page_from_freelist() routine does two scans. During the
410 * first scan, we skip zones whose corresponding bit in 'fullzones'
411 * is set or whose corresponding node in current->mems_allowed (which
412 * comes from cpusets) is not set. During the second scan, we bypass
413 * this zonelist_cache, to ensure we look methodically at each zone.
415 * Once per second, we zero out (zap) fullzones, forcing us to
416 * reconsider nodes that might have regained more free memory.
417 * The field last_full_zap is the time we last zapped fullzones.
419 * This mechanism reduces the amount of time we waste repeatedly
420 * reexaming zones for free memory when they just came up low on
421 * memory momentarilly ago.
423 * The zonelist_cache struct members logically belong in struct
424 * zonelist. However, the mempolicy zonelists constructed for
425 * MPOL_BIND are intentionally variable length (and usually much
426 * shorter). A general purpose mechanism for handling structs with
427 * multiple variable length members is more mechanism than we want
428 * here. We resort to some special case hackery instead.
430 * The MPOL_BIND zonelists don't need this zonelist_cache (in good
431 * part because they are shorter), so we put the fixed length stuff
432 * at the front of the zonelist struct, ending in a variable length
433 * zones[], as is needed by MPOL_BIND.
435 * Then we put the optional zonelist cache on the end of the zonelist
436 * struct. This optional stuff is found by a 'zlcache_ptr' pointer in
437 * the fixed length portion at the front of the struct. This pointer
438 * both enables us to find the zonelist cache, and in the case of
439 * MPOL_BIND zonelists, (which will just set the zlcache_ptr to NULL)
440 * to know that the zonelist cache is not there.
442 * The end result is that struct zonelists come in two flavors:
443 * 1) The full, fixed length version, shown below, and
444 * 2) The custom zonelists for MPOL_BIND.
445 * The custom MPOL_BIND zonelists have a NULL zlcache_ptr and no zlcache.
447 * Even though there may be multiple CPU cores on a node modifying
448 * fullzones or last_full_zap in the same zonelist_cache at the same
449 * time, we don't lock it. This is just hint data - if it is wrong now
450 * and then, the allocator will still function, perhaps a bit slower.
454 struct zonelist_cache {
455 unsigned short z_to_n[MAX_ZONES_PER_ZONELIST]; /* zone->nid */
456 DECLARE_BITMAP(fullzones, MAX_ZONES_PER_ZONELIST); /* zone full? */
457 unsigned long last_full_zap; /* when last zap'd (jiffies) */
459 #else
460 #define MAX_ZONELISTS 1
461 struct zonelist_cache;
462 #endif
465 * This struct contains information about a zone in a zonelist. It is stored
466 * here to avoid dereferences into large structures and lookups of tables
468 struct zoneref {
469 struct zone *zone; /* Pointer to actual zone */
470 int zone_idx; /* zone_idx(zoneref->zone) */
474 * One allocation request operates on a zonelist. A zonelist
475 * is a list of zones, the first one is the 'goal' of the
476 * allocation, the other zones are fallback zones, in decreasing
477 * priority.
479 * If zlcache_ptr is not NULL, then it is just the address of zlcache,
480 * as explained above. If zlcache_ptr is NULL, there is no zlcache.
482 * To speed the reading of the zonelist, the zonerefs contain the zone index
483 * of the entry being read. Helper functions to access information given
484 * a struct zoneref are
486 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs
487 * zonelist_zone_idx() - Return the index of the zone for an entry
488 * zonelist_node_idx() - Return the index of the node for an entry
490 struct zonelist {
491 struct zonelist_cache *zlcache_ptr; // NULL or &zlcache
492 struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1];
493 #ifdef CONFIG_NUMA
494 struct zonelist_cache zlcache; // optional ...
495 #endif
498 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
499 struct node_active_region {
500 unsigned long start_pfn;
501 unsigned long end_pfn;
502 int nid;
504 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
506 #ifndef CONFIG_DISCONTIGMEM
507 /* The array of struct pages - for discontigmem use pgdat->lmem_map */
508 extern struct page *mem_map;
509 #endif
512 * The pg_data_t structure is used in machines with CONFIG_DISCONTIGMEM
513 * (mostly NUMA machines?) to denote a higher-level memory zone than the
514 * zone denotes.
516 * On NUMA machines, each NUMA node would have a pg_data_t to describe
517 * it's memory layout.
519 * Memory statistics and page replacement data structures are maintained on a
520 * per-zone basis.
522 struct bootmem_data;
523 typedef struct pglist_data {
524 struct zone node_zones[MAX_NR_ZONES];
525 struct zonelist node_zonelists[MAX_ZONELISTS];
526 int nr_zones;
527 #ifdef CONFIG_FLAT_NODE_MEM_MAP
528 struct page *node_mem_map;
529 #endif
530 struct bootmem_data *bdata;
531 #ifdef CONFIG_MEMORY_HOTPLUG
533 * Must be held any time you expect node_start_pfn, node_present_pages
534 * or node_spanned_pages stay constant. Holding this will also
535 * guarantee that any pfn_valid() stays that way.
537 * Nests above zone->lock and zone->size_seqlock.
539 spinlock_t node_size_lock;
540 #endif
541 unsigned long node_start_pfn;
542 unsigned long node_present_pages; /* total number of physical pages */
543 unsigned long node_spanned_pages; /* total size of physical page
544 range, including holes */
545 int node_id;
546 wait_queue_head_t kswapd_wait;
547 struct task_struct *kswapd;
548 int kswapd_max_order;
549 } pg_data_t;
551 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
552 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
553 #ifdef CONFIG_FLAT_NODE_MEM_MAP
554 #define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr))
555 #else
556 #define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr))
557 #endif
558 #define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr))
560 #include <linux/memory_hotplug.h>
562 void get_zone_counts(unsigned long *active, unsigned long *inactive,
563 unsigned long *free);
564 void build_all_zonelists(void);
565 void wakeup_kswapd(struct zone *zone, int order);
566 int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
567 int classzone_idx, int alloc_flags);
568 enum memmap_context {
569 MEMMAP_EARLY,
570 MEMMAP_HOTPLUG,
572 extern int init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
573 unsigned long size,
574 enum memmap_context context);
576 #ifdef CONFIG_HAVE_MEMORY_PRESENT
577 void memory_present(int nid, unsigned long start, unsigned long end);
578 #else
579 static inline void memory_present(int nid, unsigned long start, unsigned long end) {}
580 #endif
582 #ifdef CONFIG_NEED_NODE_MEMMAP_SIZE
583 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
584 #endif
587 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
589 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones)
591 static inline int populated_zone(struct zone *zone)
593 return (!!zone->present_pages);
596 extern int movable_zone;
598 static inline int zone_movable_is_highmem(void)
600 #if defined(CONFIG_HIGHMEM) && defined(CONFIG_ARCH_POPULATES_NODE_MAP)
601 return movable_zone == ZONE_HIGHMEM;
602 #else
603 return 0;
604 #endif
607 static inline int is_highmem_idx(enum zone_type idx)
609 #ifdef CONFIG_HIGHMEM
610 return (idx == ZONE_HIGHMEM ||
611 (idx == ZONE_MOVABLE && zone_movable_is_highmem()));
612 #else
613 return 0;
614 #endif
617 static inline int is_normal_idx(enum zone_type idx)
619 return (idx == ZONE_NORMAL);
623 * is_highmem - helper function to quickly check if a struct zone is a
624 * highmem zone or not. This is an attempt to keep references
625 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
626 * @zone - pointer to struct zone variable
628 static inline int is_highmem(struct zone *zone)
630 #ifdef CONFIG_HIGHMEM
631 int zone_off = (char *)zone - (char *)zone->zone_pgdat->node_zones;
632 return zone_off == ZONE_HIGHMEM * sizeof(*zone) ||
633 (zone_off == ZONE_MOVABLE * sizeof(*zone) &&
634 zone_movable_is_highmem());
635 #else
636 return 0;
637 #endif
640 static inline int is_normal(struct zone *zone)
642 return zone == zone->zone_pgdat->node_zones + ZONE_NORMAL;
645 static inline int is_dma32(struct zone *zone)
647 #ifdef CONFIG_ZONE_DMA32
648 return zone == zone->zone_pgdat->node_zones + ZONE_DMA32;
649 #else
650 return 0;
651 #endif
654 static inline int is_dma(struct zone *zone)
656 #ifdef CONFIG_ZONE_DMA
657 return zone == zone->zone_pgdat->node_zones + ZONE_DMA;
658 #else
659 return 0;
660 #endif
663 /* These two functions are used to setup the per zone pages min values */
664 struct ctl_table;
665 struct file;
666 int min_free_kbytes_sysctl_handler(struct ctl_table *, int, struct file *,
667 void __user *, size_t *, loff_t *);
668 extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1];
669 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, struct file *,
670 void __user *, size_t *, loff_t *);
671 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int, struct file *,
672 void __user *, size_t *, loff_t *);
673 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int,
674 struct file *, void __user *, size_t *, loff_t *);
675 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int,
676 struct file *, void __user *, size_t *, loff_t *);
678 extern int numa_zonelist_order_handler(struct ctl_table *, int,
679 struct file *, void __user *, size_t *, loff_t *);
680 extern char numa_zonelist_order[];
681 #define NUMA_ZONELIST_ORDER_LEN 16 /* string buffer size */
683 #include <linux/topology.h>
684 /* Returns the number of the current Node. */
685 #ifndef numa_node_id
686 #define numa_node_id() (cpu_to_node(raw_smp_processor_id()))
687 #endif
689 #ifndef CONFIG_NEED_MULTIPLE_NODES
691 extern struct pglist_data contig_page_data;
692 #define NODE_DATA(nid) (&contig_page_data)
693 #define NODE_MEM_MAP(nid) mem_map
695 #else /* CONFIG_NEED_MULTIPLE_NODES */
697 #include <asm/mmzone.h>
699 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
701 extern struct pglist_data *first_online_pgdat(void);
702 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
703 extern struct zone *next_zone(struct zone *zone);
706 * for_each_online_pgdat - helper macro to iterate over all online nodes
707 * @pgdat - pointer to a pg_data_t variable
709 #define for_each_online_pgdat(pgdat) \
710 for (pgdat = first_online_pgdat(); \
711 pgdat; \
712 pgdat = next_online_pgdat(pgdat))
714 * for_each_zone - helper macro to iterate over all memory zones
715 * @zone - pointer to struct zone variable
717 * The user only needs to declare the zone variable, for_each_zone
718 * fills it in.
720 #define for_each_zone(zone) \
721 for (zone = (first_online_pgdat())->node_zones; \
722 zone; \
723 zone = next_zone(zone))
725 static inline struct zone *zonelist_zone(struct zoneref *zoneref)
727 return zoneref->zone;
730 static inline int zonelist_zone_idx(struct zoneref *zoneref)
732 return zoneref->zone_idx;
735 static inline int zonelist_node_idx(struct zoneref *zoneref)
737 #ifdef CONFIG_NUMA
738 /* zone_to_nid not available in this context */
739 return zoneref->zone->node;
740 #else
741 return 0;
742 #endif /* CONFIG_NUMA */
746 * 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
747 * @z - The cursor used as a starting point for the search
748 * @highest_zoneidx - The zone index of the highest zone to return
749 * @nodes - An optional nodemask to filter the zonelist with
750 * @zone - The first suitable zone found is returned via this parameter
752 * This function returns the next zone at or below a given zone index that is
753 * within the allowed nodemask using a cursor as the starting point for the
754 * search. The zoneref returned is a cursor that is used as the next starting
755 * point for future calls to next_zones_zonelist().
757 struct zoneref *next_zones_zonelist(struct zoneref *z,
758 enum zone_type highest_zoneidx,
759 nodemask_t *nodes,
760 struct zone **zone);
763 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
764 * @zonelist - The zonelist to search for a suitable zone
765 * @highest_zoneidx - The zone index of the highest zone to return
766 * @nodes - An optional nodemask to filter the zonelist with
767 * @zone - The first suitable zone found is returned via this parameter
769 * This function returns the first zone at or below a given zone index that is
770 * within the allowed nodemask. The zoneref returned is a cursor that can be
771 * used to iterate the zonelist with next_zones_zonelist. The cursor should
772 * not be used by the caller as it does not match the value of the zone
773 * returned.
775 static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
776 enum zone_type highest_zoneidx,
777 nodemask_t *nodes,
778 struct zone **zone)
780 return next_zones_zonelist(zonelist->_zonerefs, highest_zoneidx, nodes,
781 zone);
785 * 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
786 * @zone - The current zone in the iterator
787 * @z - The current pointer within zonelist->zones being iterated
788 * @zlist - The zonelist being iterated
789 * @highidx - The zone index of the highest zone to return
790 * @nodemask - Nodemask allowed by the allocator
792 * This iterator iterates though all zones at or below a given zone index and
793 * within a given nodemask
795 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
796 for (z = first_zones_zonelist(zlist, highidx, nodemask, &zone); \
797 zone; \
798 z = next_zones_zonelist(z, highidx, nodemask, &zone)) \
801 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
802 * @zone - The current zone in the iterator
803 * @z - The current pointer within zonelist->zones being iterated
804 * @zlist - The zonelist being iterated
805 * @highidx - The zone index of the highest zone to return
807 * This iterator iterates though all zones at or below a given zone index.
809 #define for_each_zone_zonelist(zone, z, zlist, highidx) \
810 for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL)
812 #ifdef CONFIG_SPARSEMEM
813 #include <asm/sparsemem.h>
814 #endif
816 #if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \
817 !defined(CONFIG_ARCH_POPULATES_NODE_MAP)
818 static inline unsigned long early_pfn_to_nid(unsigned long pfn)
820 return 0;
822 #endif
824 #ifdef CONFIG_FLATMEM
825 #define pfn_to_nid(pfn) (0)
826 #endif
828 #define pfn_to_section_nr(pfn) ((pfn) >> PFN_SECTION_SHIFT)
829 #define section_nr_to_pfn(sec) ((sec) << PFN_SECTION_SHIFT)
831 #ifdef CONFIG_SPARSEMEM
834 * SECTION_SHIFT #bits space required to store a section #
836 * PA_SECTION_SHIFT physical address to/from section number
837 * PFN_SECTION_SHIFT pfn to/from section number
839 #define SECTIONS_SHIFT (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS)
841 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS)
842 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
844 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT)
846 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT)
847 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1))
849 #define SECTION_BLOCKFLAGS_BITS \
850 ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS)
852 #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
853 #error Allocator MAX_ORDER exceeds SECTION_SIZE
854 #endif
856 struct page;
857 struct mem_section {
859 * This is, logically, a pointer to an array of struct
860 * pages. However, it is stored with some other magic.
861 * (see sparse.c::sparse_init_one_section())
863 * Additionally during early boot we encode node id of
864 * the location of the section here to guide allocation.
865 * (see sparse.c::memory_present())
867 * Making it a UL at least makes someone do a cast
868 * before using it wrong.
870 unsigned long section_mem_map;
872 /* See declaration of similar field in struct zone */
873 unsigned long *pageblock_flags;
876 #ifdef CONFIG_SPARSEMEM_EXTREME
877 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section))
878 #else
879 #define SECTIONS_PER_ROOT 1
880 #endif
882 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
883 #define NR_SECTION_ROOTS (NR_MEM_SECTIONS / SECTIONS_PER_ROOT)
884 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1)
886 #ifdef CONFIG_SPARSEMEM_EXTREME
887 extern struct mem_section *mem_section[NR_SECTION_ROOTS];
888 #else
889 extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
890 #endif
892 static inline struct mem_section *__nr_to_section(unsigned long nr)
894 if (!mem_section[SECTION_NR_TO_ROOT(nr)])
895 return NULL;
896 return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];
898 extern int __section_nr(struct mem_section* ms);
899 extern unsigned long usemap_size(void);
902 * We use the lower bits of the mem_map pointer to store
903 * a little bit of information. There should be at least
904 * 3 bits here due to 32-bit alignment.
906 #define SECTION_MARKED_PRESENT (1UL<<0)
907 #define SECTION_HAS_MEM_MAP (1UL<<1)
908 #define SECTION_MAP_LAST_BIT (1UL<<2)
909 #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1))
910 #define SECTION_NID_SHIFT 2
912 static inline struct page *__section_mem_map_addr(struct mem_section *section)
914 unsigned long map = section->section_mem_map;
915 map &= SECTION_MAP_MASK;
916 return (struct page *)map;
919 static inline int present_section(struct mem_section *section)
921 return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
924 static inline int present_section_nr(unsigned long nr)
926 return present_section(__nr_to_section(nr));
929 static inline int valid_section(struct mem_section *section)
931 return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
934 static inline int valid_section_nr(unsigned long nr)
936 return valid_section(__nr_to_section(nr));
939 static inline struct mem_section *__pfn_to_section(unsigned long pfn)
941 return __nr_to_section(pfn_to_section_nr(pfn));
944 static inline int pfn_valid(unsigned long pfn)
946 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
947 return 0;
948 return valid_section(__nr_to_section(pfn_to_section_nr(pfn)));
951 static inline int pfn_present(unsigned long pfn)
953 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
954 return 0;
955 return present_section(__nr_to_section(pfn_to_section_nr(pfn)));
959 * These are _only_ used during initialisation, therefore they
960 * can use __initdata ... They could have names to indicate
961 * this restriction.
963 #ifdef CONFIG_NUMA
964 #define pfn_to_nid(pfn) \
965 ({ \
966 unsigned long __pfn_to_nid_pfn = (pfn); \
967 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \
969 #else
970 #define pfn_to_nid(pfn) (0)
971 #endif
973 #define early_pfn_valid(pfn) pfn_valid(pfn)
974 void sparse_init(void);
975 #else
976 #define sparse_init() do {} while (0)
977 #define sparse_index_init(_sec, _nid) do {} while (0)
978 #endif /* CONFIG_SPARSEMEM */
980 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
981 #define early_pfn_in_nid(pfn, nid) (early_pfn_to_nid(pfn) == (nid))
982 #else
983 #define early_pfn_in_nid(pfn, nid) (1)
984 #endif
986 #ifndef early_pfn_valid
987 #define early_pfn_valid(pfn) (1)
988 #endif
990 void memory_present(int nid, unsigned long start, unsigned long end);
991 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
994 * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we
995 * need to check pfn validility within that MAX_ORDER_NR_PAGES block.
996 * pfn_valid_within() should be used in this case; we optimise this away
997 * when we have no holes within a MAX_ORDER_NR_PAGES block.
999 #ifdef CONFIG_HOLES_IN_ZONE
1000 #define pfn_valid_within(pfn) pfn_valid(pfn)
1001 #else
1002 #define pfn_valid_within(pfn) (1)
1003 #endif
1005 #endif /* !__GENERATING_BOUNDS.H */
1006 #endif /* !__ASSEMBLY__ */
1007 #endif /* _LINUX_MMZONE_H */