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 <linux/bounds.h>
19 #include <asm/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 * coelesce naturally under reasonable reclaim pressure and those which
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 return get_pageblock_flags_group(page, PB_migrate, PB_migrate_end);
57 struct list_head free_list[MIGRATE_TYPES];
58 unsigned long nr_free;
64 * zone->lock and zone->lru_lock are two of the hottest locks in the kernel.
65 * So add a wild amount of padding here to ensure that they fall into separate
66 * cachelines. There are very few zone structures in the machine, so space
67 * consumption is not a concern here.
69 #if defined(CONFIG_SMP)
72 } ____cacheline_internodealigned_in_smp;
73 #define ZONE_PADDING(name) struct zone_padding name;
75 #define ZONE_PADDING(name)
79 /* First 128 byte cacheline (assuming 64 bit words) */
82 NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */
83 NR_ACTIVE_ANON, /* " " " " " */
84 NR_INACTIVE_FILE, /* " " " " " */
85 NR_ACTIVE_FILE, /* " " " " " */
86 NR_UNEVICTABLE, /* " " " " " */
87 NR_MLOCK, /* mlock()ed pages found and moved off LRU */
88 NR_ANON_PAGES, /* Mapped anonymous pages */
89 NR_FILE_MAPPED, /* pagecache pages mapped into pagetables.
90 only modified from process context */
95 NR_SLAB_UNRECLAIMABLE,
96 NR_PAGETABLE, /* used for pagetables */
98 /* Second 128 byte cacheline */
99 NR_UNSTABLE_NFS, /* NFS unstable pages */
102 NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */
103 NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */
104 NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */
105 NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */
107 NUMA_HIT, /* allocated in intended node */
108 NUMA_MISS, /* allocated in non intended node */
109 NUMA_FOREIGN, /* was intended here, hit elsewhere */
110 NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */
111 NUMA_LOCAL, /* allocation from local node */
112 NUMA_OTHER, /* allocation from other node */
114 NR_VM_ZONE_STAT_ITEMS };
117 * We do arithmetic on the LRU lists in various places in the code,
118 * so it is important to keep the active lists LRU_ACTIVE higher in
119 * the array than the corresponding inactive lists, and to keep
120 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists.
122 * This has to be kept in sync with the statistics in zone_stat_item
123 * above and the descriptions in vmstat_text in mm/vmstat.c
130 LRU_INACTIVE_ANON = LRU_BASE,
131 LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE,
132 LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE,
133 LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE,
138 #define for_each_lru(l) for (l = 0; l < NR_LRU_LISTS; l++)
140 #define for_each_evictable_lru(l) for (l = 0; l <= LRU_ACTIVE_FILE; l++)
142 static inline int is_file_lru(enum lru_list l)
144 return (l == LRU_INACTIVE_FILE || l == LRU_ACTIVE_FILE);
147 static inline int is_active_lru(enum lru_list l)
149 return (l == LRU_ACTIVE_ANON || l == LRU_ACTIVE_FILE);
152 static inline int is_unevictable_lru(enum lru_list l)
154 return (l == LRU_UNEVICTABLE);
157 enum zone_watermarks {
164 #define min_wmark_pages(z) (z->watermark[WMARK_MIN])
165 #define low_wmark_pages(z) (z->watermark[WMARK_LOW])
166 #define high_wmark_pages(z) (z->watermark[WMARK_HIGH])
168 struct per_cpu_pages {
169 int count; /* number of pages in the list */
170 int high; /* high watermark, emptying needed */
171 int batch; /* chunk size for buddy add/remove */
172 struct list_head list; /* the list of pages */
175 struct per_cpu_pageset {
176 struct per_cpu_pages pcp;
182 s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS];
184 } ____cacheline_aligned_in_smp;
187 #define zone_pcp(__z, __cpu) ((__z)->pageset[(__cpu)])
189 #define zone_pcp(__z, __cpu) (&(__z)->pageset[(__cpu)])
192 #endif /* !__GENERATING_BOUNDS.H */
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.
205 * ---------------------------
206 * parisc, ia64, sparc <4G
209 * alpha Unlimited or 0-16MB.
211 * i386, x86_64 and multiple other arches
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.
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.
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
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
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
262 #error ZONES_SHIFT -- too many zones configured adjust calculation
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
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];
284 /* Fields commonly accessed by the page allocator */
286 /* zone watermarks, access with *_wmark_pages(zone) macros */
287 unsigned long watermark[NR_WMARK];
290 * We don't know if the memory that we're going to allocate will be freeable
291 * or/and it will be released eventually, so to avoid totally wasting several
292 * GB of ram we must reserve some of the lower zone memory (otherwise we risk
293 * to run OOM on the lower zones despite there's tons of freeable ram
294 * on the higher zones). This array is recalculated at runtime if the
295 * sysctl_lowmem_reserve_ratio sysctl changes.
297 unsigned long lowmem_reserve[MAX_NR_ZONES];
302 * zone reclaim becomes active if more unmapped pages exist.
304 unsigned long min_unmapped_pages;
305 unsigned long min_slab_pages;
306 struct per_cpu_pageset *pageset[NR_CPUS];
308 struct per_cpu_pageset pageset[NR_CPUS];
311 * free areas of different sizes
314 #ifdef CONFIG_MEMORY_HOTPLUG
315 /* see spanned/present_pages for more description */
316 seqlock_t span_seqlock;
318 struct free_area free_area[MAX_ORDER];
320 #ifndef CONFIG_SPARSEMEM
322 * Flags for a pageblock_nr_pages block. See pageblock-flags.h.
323 * In SPARSEMEM, this map is stored in struct mem_section
325 unsigned long *pageblock_flags;
326 #endif /* CONFIG_SPARSEMEM */
331 /* Fields commonly accessed by the page reclaim scanner */
334 struct list_head list;
337 struct zone_reclaim_stat reclaim_stat;
339 unsigned long pages_scanned; /* since last reclaim */
340 unsigned long flags; /* zone flags, see below */
342 /* Zone statistics */
343 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
346 * prev_priority holds the scanning priority for this zone. It is
347 * defined as the scanning priority at which we achieved our reclaim
348 * target at the previous try_to_free_pages() or balance_pgdat()
351 * We use prev_priority as a measure of how much stress page reclaim is
352 * under - it drives the swappiness decision: whether to unmap mapped
355 * Access to both this field is quite racy even on uniprocessor. But
356 * it is expected to average out OK.
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;
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:
422 } ____cacheline_internodealigned_in_smp;
425 ZONE_ALL_UNRECLAIMABLE, /* all pages pinned */
426 ZONE_RECLAIM_LOCKED, /* prevents concurrent reclaim */
427 ZONE_OOM_LOCKED, /* zone is in OOM killer zonelist */
430 static inline void zone_set_flag(struct zone *zone, zone_flags_t flag)
432 set_bit(flag, &zone->flags);
435 static inline int zone_test_and_set_flag(struct zone *zone, zone_flags_t flag)
437 return test_and_set_bit(flag, &zone->flags);
440 static inline void zone_clear_flag(struct zone *zone, zone_flags_t flag)
442 clear_bit(flag, &zone->flags);
445 static inline int zone_is_all_unreclaimable(const struct zone *zone)
447 return test_bit(ZONE_ALL_UNRECLAIMABLE, &zone->flags);
450 static inline int zone_is_reclaim_locked(const struct zone *zone)
452 return test_bit(ZONE_RECLAIM_LOCKED, &zone->flags);
455 static inline int zone_is_oom_locked(const struct zone *zone)
457 return test_bit(ZONE_OOM_LOCKED, &zone->flags);
461 * The "priority" of VM scanning is how much of the queues we will scan in one
462 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
463 * queues ("queue_length >> 12") during an aging round.
465 #define DEF_PRIORITY 12
467 /* Maximum number of zones on a zonelist */
468 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
473 * The NUMA zonelists are doubled becausse we need zonelists that restrict the
474 * allocations to a single node for GFP_THISNODE.
476 * [0] : Zonelist with fallback
477 * [1] : No fallback (GFP_THISNODE)
479 #define MAX_ZONELISTS 2
483 * We cache key information from each zonelist for smaller cache
484 * footprint when scanning for free pages in get_page_from_freelist().
486 * 1) The BITMAP fullzones tracks which zones in a zonelist have come
487 * up short of free memory since the last time (last_fullzone_zap)
488 * we zero'd fullzones.
489 * 2) The array z_to_n[] maps each zone in the zonelist to its node
490 * id, so that we can efficiently evaluate whether that node is
491 * set in the current tasks mems_allowed.
493 * Both fullzones and z_to_n[] are one-to-one with the zonelist,
494 * indexed by a zones offset in the zonelist zones[] array.
496 * The get_page_from_freelist() routine does two scans. During the
497 * first scan, we skip zones whose corresponding bit in 'fullzones'
498 * is set or whose corresponding node in current->mems_allowed (which
499 * comes from cpusets) is not set. During the second scan, we bypass
500 * this zonelist_cache, to ensure we look methodically at each zone.
502 * Once per second, we zero out (zap) fullzones, forcing us to
503 * reconsider nodes that might have regained more free memory.
504 * The field last_full_zap is the time we last zapped fullzones.
506 * This mechanism reduces the amount of time we waste repeatedly
507 * reexaming zones for free memory when they just came up low on
508 * memory momentarilly ago.
510 * The zonelist_cache struct members logically belong in struct
511 * zonelist. However, the mempolicy zonelists constructed for
512 * MPOL_BIND are intentionally variable length (and usually much
513 * shorter). A general purpose mechanism for handling structs with
514 * multiple variable length members is more mechanism than we want
515 * here. We resort to some special case hackery instead.
517 * The MPOL_BIND zonelists don't need this zonelist_cache (in good
518 * part because they are shorter), so we put the fixed length stuff
519 * at the front of the zonelist struct, ending in a variable length
520 * zones[], as is needed by MPOL_BIND.
522 * Then we put the optional zonelist cache on the end of the zonelist
523 * struct. This optional stuff is found by a 'zlcache_ptr' pointer in
524 * the fixed length portion at the front of the struct. This pointer
525 * both enables us to find the zonelist cache, and in the case of
526 * MPOL_BIND zonelists, (which will just set the zlcache_ptr to NULL)
527 * to know that the zonelist cache is not there.
529 * The end result is that struct zonelists come in two flavors:
530 * 1) The full, fixed length version, shown below, and
531 * 2) The custom zonelists for MPOL_BIND.
532 * The custom MPOL_BIND zonelists have a NULL zlcache_ptr and no zlcache.
534 * Even though there may be multiple CPU cores on a node modifying
535 * fullzones or last_full_zap in the same zonelist_cache at the same
536 * time, we don't lock it. This is just hint data - if it is wrong now
537 * and then, the allocator will still function, perhaps a bit slower.
541 struct zonelist_cache {
542 unsigned short z_to_n[MAX_ZONES_PER_ZONELIST]; /* zone->nid */
543 DECLARE_BITMAP(fullzones, MAX_ZONES_PER_ZONELIST); /* zone full? */
544 unsigned long last_full_zap; /* when last zap'd (jiffies) */
547 #define MAX_ZONELISTS 1
548 struct zonelist_cache;
552 * This struct contains information about a zone in a zonelist. It is stored
553 * here to avoid dereferences into large structures and lookups of tables
556 struct zone *zone; /* Pointer to actual zone */
557 int zone_idx; /* zone_idx(zoneref->zone) */
561 * One allocation request operates on a zonelist. A zonelist
562 * is a list of zones, the first one is the 'goal' of the
563 * allocation, the other zones are fallback zones, in decreasing
566 * If zlcache_ptr is not NULL, then it is just the address of zlcache,
567 * as explained above. If zlcache_ptr is NULL, there is no zlcache.
569 * To speed the reading of the zonelist, the zonerefs contain the zone index
570 * of the entry being read. Helper functions to access information given
571 * a struct zoneref are
573 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs
574 * zonelist_zone_idx() - Return the index of the zone for an entry
575 * zonelist_node_idx() - Return the index of the node for an entry
578 struct zonelist_cache *zlcache_ptr; // NULL or &zlcache
579 struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1];
581 struct zonelist_cache zlcache; // optional ...
585 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
586 struct node_active_region {
587 unsigned long start_pfn;
588 unsigned long end_pfn;
591 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
593 #ifndef CONFIG_DISCONTIGMEM
594 /* The array of struct pages - for discontigmem use pgdat->lmem_map */
595 extern struct page *mem_map;
599 * The pg_data_t structure is used in machines with CONFIG_DISCONTIGMEM
600 * (mostly NUMA machines?) to denote a higher-level memory zone than the
603 * On NUMA machines, each NUMA node would have a pg_data_t to describe
604 * it's memory layout.
606 * Memory statistics and page replacement data structures are maintained on a
610 typedef struct pglist_data {
611 struct zone node_zones[MAX_NR_ZONES];
612 struct zonelist node_zonelists[MAX_ZONELISTS];
614 #ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */
615 struct page *node_mem_map;
616 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
617 struct page_cgroup *node_page_cgroup;
620 struct bootmem_data *bdata;
621 #ifdef CONFIG_MEMORY_HOTPLUG
623 * Must be held any time you expect node_start_pfn, node_present_pages
624 * or node_spanned_pages stay constant. Holding this will also
625 * guarantee that any pfn_valid() stays that way.
627 * Nests above zone->lock and zone->size_seqlock.
629 spinlock_t node_size_lock;
631 unsigned long node_start_pfn;
632 unsigned long node_present_pages; /* total number of physical pages */
633 unsigned long node_spanned_pages; /* total size of physical page
634 range, including holes */
636 wait_queue_head_t kswapd_wait;
637 struct task_struct *kswapd;
638 int kswapd_max_order;
641 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
642 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
643 #ifdef CONFIG_FLAT_NODE_MEM_MAP
644 #define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr))
646 #define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr))
648 #define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr))
650 #include <linux/memory_hotplug.h>
652 void get_zone_counts(unsigned long *active, unsigned long *inactive,
653 unsigned long *free);
654 void build_all_zonelists(void);
655 void wakeup_kswapd(struct zone *zone, int order);
656 int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
657 int classzone_idx, int alloc_flags);
658 enum memmap_context {
662 extern int init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
664 enum memmap_context context);
666 #ifdef CONFIG_HAVE_MEMORY_PRESENT
667 void memory_present(int nid, unsigned long start, unsigned long end);
669 static inline void memory_present(int nid, unsigned long start, unsigned long end) {}
672 #ifdef CONFIG_NEED_NODE_MEMMAP_SIZE
673 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
677 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
679 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones)
681 static inline int populated_zone(struct zone *zone)
683 return (!!zone->present_pages);
686 extern int movable_zone;
688 static inline int zone_movable_is_highmem(void)
690 #if defined(CONFIG_HIGHMEM) && defined(CONFIG_ARCH_POPULATES_NODE_MAP)
691 return movable_zone == ZONE_HIGHMEM;
697 static inline int is_highmem_idx(enum zone_type idx)
699 #ifdef CONFIG_HIGHMEM
700 return (idx == ZONE_HIGHMEM ||
701 (idx == ZONE_MOVABLE && zone_movable_is_highmem()));
707 static inline int is_normal_idx(enum zone_type idx)
709 return (idx == ZONE_NORMAL);
713 * is_highmem - helper function to quickly check if a struct zone is a
714 * highmem zone or not. This is an attempt to keep references
715 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
716 * @zone - pointer to struct zone variable
718 static inline int is_highmem(struct zone *zone)
720 #ifdef CONFIG_HIGHMEM
721 int zone_off = (char *)zone - (char *)zone->zone_pgdat->node_zones;
722 return zone_off == ZONE_HIGHMEM * sizeof(*zone) ||
723 (zone_off == ZONE_MOVABLE * sizeof(*zone) &&
724 zone_movable_is_highmem());
730 static inline int is_normal(struct zone *zone)
732 return zone == zone->zone_pgdat->node_zones + ZONE_NORMAL;
735 static inline int is_dma32(struct zone *zone)
737 #ifdef CONFIG_ZONE_DMA32
738 return zone == zone->zone_pgdat->node_zones + ZONE_DMA32;
744 static inline int is_dma(struct zone *zone)
746 #ifdef CONFIG_ZONE_DMA
747 return zone == zone->zone_pgdat->node_zones + ZONE_DMA;
753 /* These two functions are used to setup the per zone pages min values */
756 int min_free_kbytes_sysctl_handler(struct ctl_table *, int, struct file *,
757 void __user *, size_t *, loff_t *);
758 extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1];
759 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, struct file *,
760 void __user *, size_t *, loff_t *);
761 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int, struct file *,
762 void __user *, size_t *, loff_t *);
763 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int,
764 struct file *, void __user *, size_t *, loff_t *);
765 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int,
766 struct file *, void __user *, size_t *, loff_t *);
768 extern int numa_zonelist_order_handler(struct ctl_table *, int,
769 struct file *, void __user *, size_t *, loff_t *);
770 extern char numa_zonelist_order[];
771 #define NUMA_ZONELIST_ORDER_LEN 16 /* string buffer size */
773 #ifndef CONFIG_NEED_MULTIPLE_NODES
775 extern struct pglist_data contig_page_data;
776 #define NODE_DATA(nid) (&contig_page_data)
777 #define NODE_MEM_MAP(nid) mem_map
779 #else /* CONFIG_NEED_MULTIPLE_NODES */
781 #include <asm/mmzone.h>
783 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
785 extern struct pglist_data *first_online_pgdat(void);
786 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
787 extern struct zone *next_zone(struct zone *zone);
790 * for_each_online_pgdat - helper macro to iterate over all online nodes
791 * @pgdat - pointer to a pg_data_t variable
793 #define for_each_online_pgdat(pgdat) \
794 for (pgdat = first_online_pgdat(); \
796 pgdat = next_online_pgdat(pgdat))
798 * for_each_zone - helper macro to iterate over all memory zones
799 * @zone - pointer to struct zone variable
801 * The user only needs to declare the zone variable, for_each_zone
804 #define for_each_zone(zone) \
805 for (zone = (first_online_pgdat())->node_zones; \
807 zone = next_zone(zone))
809 #define for_each_populated_zone(zone) \
810 for (zone = (first_online_pgdat())->node_zones; \
812 zone = next_zone(zone)) \
813 if (!populated_zone(zone)) \
817 static inline struct zone *zonelist_zone(struct zoneref *zoneref)
819 return zoneref->zone;
822 static inline int zonelist_zone_idx(struct zoneref *zoneref)
824 return zoneref->zone_idx;
827 static inline int zonelist_node_idx(struct zoneref *zoneref)
830 /* zone_to_nid not available in this context */
831 return zoneref->zone->node;
834 #endif /* CONFIG_NUMA */
838 * 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
839 * @z - The cursor used as a starting point for the search
840 * @highest_zoneidx - The zone index of the highest zone to return
841 * @nodes - An optional nodemask to filter the zonelist with
842 * @zone - The first suitable zone found is returned via this parameter
844 * This function returns the next zone at or below a given zone index that is
845 * within the allowed nodemask using a cursor as the starting point for the
846 * search. The zoneref returned is a cursor that represents the current zone
847 * being examined. It should be advanced by one before calling
848 * next_zones_zonelist again.
850 struct zoneref *next_zones_zonelist(struct zoneref *z,
851 enum zone_type highest_zoneidx,
856 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
857 * @zonelist - The zonelist to search for a suitable zone
858 * @highest_zoneidx - The zone index of the highest zone to return
859 * @nodes - An optional nodemask to filter the zonelist with
860 * @zone - The first suitable zone found is returned via this parameter
862 * This function returns the first zone at or below a given zone index that is
863 * within the allowed nodemask. The zoneref returned is a cursor that can be
864 * used to iterate the zonelist with next_zones_zonelist by advancing it by
865 * one before calling.
867 static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
868 enum zone_type highest_zoneidx,
872 return next_zones_zonelist(zonelist->_zonerefs, highest_zoneidx, nodes,
877 * 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
878 * @zone - The current zone in the iterator
879 * @z - The current pointer within zonelist->zones being iterated
880 * @zlist - The zonelist being iterated
881 * @highidx - The zone index of the highest zone to return
882 * @nodemask - Nodemask allowed by the allocator
884 * This iterator iterates though all zones at or below a given zone index and
885 * within a given nodemask
887 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
888 for (z = first_zones_zonelist(zlist, highidx, nodemask, &zone); \
890 z = next_zones_zonelist(++z, highidx, nodemask, &zone)) \
893 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
894 * @zone - The current zone in the iterator
895 * @z - The current pointer within zonelist->zones being iterated
896 * @zlist - The zonelist being iterated
897 * @highidx - The zone index of the highest zone to return
899 * This iterator iterates though all zones at or below a given zone index.
901 #define for_each_zone_zonelist(zone, z, zlist, highidx) \
902 for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL)
904 #ifdef CONFIG_SPARSEMEM
905 #include <asm/sparsemem.h>
908 #if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \
909 !defined(CONFIG_ARCH_POPULATES_NODE_MAP)
910 static inline unsigned long early_pfn_to_nid(unsigned long pfn)
916 #ifdef CONFIG_FLATMEM
917 #define pfn_to_nid(pfn) (0)
920 #define pfn_to_section_nr(pfn) ((pfn) >> PFN_SECTION_SHIFT)
921 #define section_nr_to_pfn(sec) ((sec) << PFN_SECTION_SHIFT)
923 #ifdef CONFIG_SPARSEMEM
926 * SECTION_SHIFT #bits space required to store a section #
928 * PA_SECTION_SHIFT physical address to/from section number
929 * PFN_SECTION_SHIFT pfn to/from section number
931 #define SECTIONS_SHIFT (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS)
933 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS)
934 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
936 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT)
938 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT)
939 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1))
941 #define SECTION_BLOCKFLAGS_BITS \
942 ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS)
944 #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
945 #error Allocator MAX_ORDER exceeds SECTION_SIZE
952 * This is, logically, a pointer to an array of struct
953 * pages. However, it is stored with some other magic.
954 * (see sparse.c::sparse_init_one_section())
956 * Additionally during early boot we encode node id of
957 * the location of the section here to guide allocation.
958 * (see sparse.c::memory_present())
960 * Making it a UL at least makes someone do a cast
961 * before using it wrong.
963 unsigned long section_mem_map;
965 /* See declaration of similar field in struct zone */
966 unsigned long *pageblock_flags;
967 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
969 * If !SPARSEMEM, pgdat doesn't have page_cgroup pointer. We use
970 * section. (see memcontrol.h/page_cgroup.h about this.)
972 struct page_cgroup *page_cgroup;
977 #ifdef CONFIG_SPARSEMEM_EXTREME
978 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section))
980 #define SECTIONS_PER_ROOT 1
983 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
984 #define NR_SECTION_ROOTS (NR_MEM_SECTIONS / SECTIONS_PER_ROOT)
985 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1)
987 #ifdef CONFIG_SPARSEMEM_EXTREME
988 extern struct mem_section *mem_section[NR_SECTION_ROOTS];
990 extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
993 static inline struct mem_section *__nr_to_section(unsigned long nr)
995 if (!mem_section[SECTION_NR_TO_ROOT(nr)])
997 return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];
999 extern int __section_nr(struct mem_section* ms);
1000 extern unsigned long usemap_size(void);
1003 * We use the lower bits of the mem_map pointer to store
1004 * a little bit of information. There should be at least
1005 * 3 bits here due to 32-bit alignment.
1007 #define SECTION_MARKED_PRESENT (1UL<<0)
1008 #define SECTION_HAS_MEM_MAP (1UL<<1)
1009 #define SECTION_MAP_LAST_BIT (1UL<<2)
1010 #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1))
1011 #define SECTION_NID_SHIFT 2
1013 static inline struct page *__section_mem_map_addr(struct mem_section *section)
1015 unsigned long map = section->section_mem_map;
1016 map &= SECTION_MAP_MASK;
1017 return (struct page *)map;
1020 static inline int present_section(struct mem_section *section)
1022 return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
1025 static inline int present_section_nr(unsigned long nr)
1027 return present_section(__nr_to_section(nr));
1030 static inline int valid_section(struct mem_section *section)
1032 return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
1035 static inline int valid_section_nr(unsigned long nr)
1037 return valid_section(__nr_to_section(nr));
1040 static inline struct mem_section *__pfn_to_section(unsigned long pfn)
1042 return __nr_to_section(pfn_to_section_nr(pfn));
1045 static inline int pfn_valid(unsigned long pfn)
1047 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
1049 return valid_section(__nr_to_section(pfn_to_section_nr(pfn)));
1052 static inline int pfn_present(unsigned long pfn)
1054 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
1056 return present_section(__nr_to_section(pfn_to_section_nr(pfn)));
1060 * These are _only_ used during initialisation, therefore they
1061 * can use __initdata ... They could have names to indicate
1065 #define pfn_to_nid(pfn) \
1067 unsigned long __pfn_to_nid_pfn = (pfn); \
1068 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \
1071 #define pfn_to_nid(pfn) (0)
1074 #define early_pfn_valid(pfn) pfn_valid(pfn)
1075 void sparse_init(void);
1077 #define sparse_init() do {} while (0)
1078 #define sparse_index_init(_sec, _nid) do {} while (0)
1079 #endif /* CONFIG_SPARSEMEM */
1081 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1082 bool early_pfn_in_nid(unsigned long pfn, int nid);
1084 #define early_pfn_in_nid(pfn, nid) (1)
1087 #ifndef early_pfn_valid
1088 #define early_pfn_valid(pfn) (1)
1091 void memory_present(int nid, unsigned long start, unsigned long end);
1092 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
1095 * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we
1096 * need to check pfn validility within that MAX_ORDER_NR_PAGES block.
1097 * pfn_valid_within() should be used in this case; we optimise this away
1098 * when we have no holes within a MAX_ORDER_NR_PAGES block.
1100 #ifdef CONFIG_HOLES_IN_ZONE
1101 #define pfn_valid_within(pfn) pfn_valid(pfn)
1103 #define pfn_valid_within(pfn) (1)
1106 #ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
1108 * pfn_valid() is meant to be able to tell if a given PFN has valid memmap
1109 * associated with it or not. In FLATMEM, it is expected that holes always
1110 * have valid memmap as long as there is valid PFNs either side of the hole.
1111 * In SPARSEMEM, it is assumed that a valid section has a memmap for the
1114 * However, an ARM, and maybe other embedded architectures in the future
1115 * free memmap backing holes to save memory on the assumption the memmap is
1116 * never used. The page_zone linkages are then broken even though pfn_valid()
1117 * returns true. A walker of the full memmap must then do this additional
1118 * check to ensure the memmap they are looking at is sane by making sure
1119 * the zone and PFN linkages are still valid. This is expensive, but walkers
1120 * of the full memmap are extremely rare.
1122 int memmap_valid_within(unsigned long pfn,
1123 struct page *page, struct zone *zone);
1125 static inline int memmap_valid_within(unsigned long pfn,
1126 struct page *page, struct zone *zone)
1130 #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */
1132 #endif /* !__GENERATING_BOUNDS.H */
1133 #endif /* !__ASSEMBLY__ */
1134 #endif /* _LINUX_MMZONE_H */