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_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
);
58 struct list_head free_list
[MIGRATE_TYPES
];
59 unsigned long nr_free
;
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)
73 } ____cacheline_internodealigned_in_smp
;
74 #define ZONE_PADDING(name) struct zone_padding name;
76 #define ZONE_PADDING(name)
80 /* First 128 byte cacheline (assuming 64 bit words) */
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 */
96 NR_SLAB_UNRECLAIMABLE
,
97 NR_PAGETABLE
, /* used for pagetables */
99 /* Second 128 byte cacheline */
100 NR_UNSTABLE_NFS
, /* NFS unstable pages */
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) */
108 NUMA_HIT
, /* allocated in intended node */
109 NUMA_MISS
, /* allocated in non intended node */
110 NUMA_FOREIGN
, /* was intended here, hit elsewhere */
111 NUMA_INTERLEAVE_HIT
, /* interleaver preferred this zone */
112 NUMA_LOCAL
, /* allocation from local node */
113 NUMA_OTHER
, /* allocation from other node */
115 NR_VM_ZONE_STAT_ITEMS
};
118 * We do arithmetic on the LRU lists in various places in the code,
119 * so it is important to keep the active lists LRU_ACTIVE higher in
120 * the array than the corresponding inactive lists, and to keep
121 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists.
123 * This has to be kept in sync with the statistics in zone_stat_item
124 * above and the descriptions in vmstat_text in mm/vmstat.c
131 LRU_INACTIVE_ANON
= LRU_BASE
,
132 LRU_ACTIVE_ANON
= LRU_BASE
+ LRU_ACTIVE
,
133 LRU_INACTIVE_FILE
= LRU_BASE
+ LRU_FILE
,
134 LRU_ACTIVE_FILE
= LRU_BASE
+ LRU_FILE
+ LRU_ACTIVE
,
139 #define for_each_lru(l) for (l = 0; l < NR_LRU_LISTS; l++)
141 #define for_each_evictable_lru(l) for (l = 0; l <= LRU_ACTIVE_FILE; l++)
143 static inline int is_file_lru(enum lru_list l
)
145 return (l
== LRU_INACTIVE_FILE
|| l
== LRU_ACTIVE_FILE
);
148 static inline int is_active_lru(enum lru_list l
)
150 return (l
== LRU_ACTIVE_ANON
|| l
== LRU_ACTIVE_FILE
);
153 static inline int is_unevictable_lru(enum lru_list l
)
155 return (l
== LRU_UNEVICTABLE
);
158 enum zone_watermarks
{
165 #define min_wmark_pages(z) (z->watermark[WMARK_MIN])
166 #define low_wmark_pages(z) (z->watermark[WMARK_LOW])
167 #define high_wmark_pages(z) (z->watermark[WMARK_HIGH])
169 struct per_cpu_pages
{
170 int count
; /* number of pages in the list */
171 int high
; /* high watermark, emptying needed */
172 int batch
; /* chunk size for buddy add/remove */
174 /* Lists of pages, one per migrate type stored on the pcp-lists */
175 struct list_head lists
[MIGRATE_PCPTYPES
];
178 struct per_cpu_pageset
{
179 struct per_cpu_pages pcp
;
185 s8 vm_stat_diff
[NR_VM_ZONE_STAT_ITEMS
];
187 } ____cacheline_aligned_in_smp
;
190 #define zone_pcp(__z, __cpu) ((__z)->pageset[(__cpu)])
192 #define zone_pcp(__z, __cpu) (&(__z)->pageset[(__cpu)])
195 #endif /* !__GENERATING_BOUNDS.H */
198 #ifdef CONFIG_ZONE_DMA
200 * ZONE_DMA is used when there are devices that are not able
201 * to do DMA to all of addressable memory (ZONE_NORMAL). Then we
202 * carve out the portion of memory that is needed for these devices.
203 * The range is arch specific.
208 * ---------------------------
209 * parisc, ia64, sparc <4G
212 * alpha Unlimited or 0-16MB.
214 * i386, x86_64 and multiple other arches
219 #ifdef CONFIG_ZONE_DMA32
221 * x86_64 needs two ZONE_DMAs because it supports devices that are
222 * only able to do DMA to the lower 16M but also 32 bit devices that
223 * can only do DMA areas below 4G.
228 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be
229 * performed on pages in ZONE_NORMAL if the DMA devices support
230 * transfers to all addressable memory.
233 #ifdef CONFIG_HIGHMEM
235 * A memory area that is only addressable by the kernel through
236 * mapping portions into its own address space. This is for example
237 * used by i386 to allow the kernel to address the memory beyond
238 * 900MB. The kernel will set up special mappings (page
239 * table entries on i386) for each page that the kernel needs to
248 #ifndef __GENERATING_BOUNDS_H
251 * When a memory allocation must conform to specific limitations (such
252 * as being suitable for DMA) the caller will pass in hints to the
253 * allocator in the gfp_mask, in the zone modifier bits. These bits
254 * are used to select a priority ordered list of memory zones which
255 * match the requested limits. See gfp_zone() in include/linux/gfp.h
259 #define ZONES_SHIFT 0
260 #elif MAX_NR_ZONES <= 2
261 #define ZONES_SHIFT 1
262 #elif MAX_NR_ZONES <= 4
263 #define ZONES_SHIFT 2
265 #error ZONES_SHIFT -- too many zones configured adjust calculation
268 struct zone_reclaim_stat
{
270 * The pageout code in vmscan.c keeps track of how many of the
271 * mem/swap backed and file backed pages are refeferenced.
272 * The higher the rotated/scanned ratio, the more valuable
275 * The anon LRU stats live in [0], file LRU stats in [1]
277 unsigned long recent_rotated
[2];
278 unsigned long recent_scanned
[2];
281 * accumulated for batching
283 unsigned long nr_saved_scan
[NR_LRU_LISTS
];
287 /* Fields commonly accessed by the page allocator */
289 /* zone watermarks, access with *_wmark_pages(zone) macros */
290 unsigned long watermark
[NR_WMARK
];
293 * We don't know if the memory that we're going to allocate will be freeable
294 * or/and it will be released eventually, so to avoid totally wasting several
295 * GB of ram we must reserve some of the lower zone memory (otherwise we risk
296 * to run OOM on the lower zones despite there's tons of freeable ram
297 * on the higher zones). This array is recalculated at runtime if the
298 * sysctl_lowmem_reserve_ratio sysctl changes.
300 unsigned long lowmem_reserve
[MAX_NR_ZONES
];
305 * zone reclaim becomes active if more unmapped pages exist.
307 unsigned long min_unmapped_pages
;
308 unsigned long min_slab_pages
;
309 struct per_cpu_pageset
*pageset
[NR_CPUS
];
311 struct per_cpu_pageset pageset
[NR_CPUS
];
314 * free areas of different sizes
317 #ifdef CONFIG_MEMORY_HOTPLUG
318 /* see spanned/present_pages for more description */
319 seqlock_t span_seqlock
;
321 struct free_area free_area
[MAX_ORDER
];
323 #ifndef CONFIG_SPARSEMEM
325 * Flags for a pageblock_nr_pages block. See pageblock-flags.h.
326 * In SPARSEMEM, this map is stored in struct mem_section
328 unsigned long *pageblock_flags
;
329 #endif /* CONFIG_SPARSEMEM */
334 /* Fields commonly accessed by the page reclaim scanner */
337 struct list_head list
;
340 struct zone_reclaim_stat reclaim_stat
;
342 unsigned long pages_scanned
; /* since last reclaim */
343 unsigned long flags
; /* zone flags, see below */
345 /* Zone statistics */
346 atomic_long_t vm_stat
[NR_VM_ZONE_STAT_ITEMS
];
349 * prev_priority holds the scanning priority for this zone. It is
350 * defined as the scanning priority at which we achieved our reclaim
351 * target at the previous try_to_free_pages() or balance_pgdat()
354 * We use prev_priority as a measure of how much stress page reclaim is
355 * under - it drives the swappiness decision: whether to unmap mapped
358 * Access to both this field is quite racy even on uniprocessor. But
359 * it is expected to average out OK.
364 * The target ratio of ACTIVE_ANON to INACTIVE_ANON pages on
365 * this zone's LRU. Maintained by the pageout code.
367 unsigned int inactive_ratio
;
371 /* Rarely used or read-mostly fields */
374 * wait_table -- the array holding the hash table
375 * wait_table_hash_nr_entries -- the size of the hash table array
376 * wait_table_bits -- wait_table_size == (1 << wait_table_bits)
378 * The purpose of all these is to keep track of the people
379 * waiting for a page to become available and make them
380 * runnable again when possible. The trouble is that this
381 * consumes a lot of space, especially when so few things
382 * wait on pages at a given time. So instead of using
383 * per-page waitqueues, we use a waitqueue hash table.
385 * The bucket discipline is to sleep on the same queue when
386 * colliding and wake all in that wait queue when removing.
387 * When something wakes, it must check to be sure its page is
388 * truly available, a la thundering herd. The cost of a
389 * collision is great, but given the expected load of the
390 * table, they should be so rare as to be outweighed by the
391 * benefits from the saved space.
393 * __wait_on_page_locked() and unlock_page() in mm/filemap.c, are the
394 * primary users of these fields, and in mm/page_alloc.c
395 * free_area_init_core() performs the initialization of them.
397 wait_queue_head_t
* wait_table
;
398 unsigned long wait_table_hash_nr_entries
;
399 unsigned long wait_table_bits
;
402 * Discontig memory support fields.
404 struct pglist_data
*zone_pgdat
;
405 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
406 unsigned long zone_start_pfn
;
409 * zone_start_pfn, spanned_pages and present_pages are all
410 * protected by span_seqlock. It is a seqlock because it has
411 * to be read outside of zone->lock, and it is done in the main
412 * allocator path. But, it is written quite infrequently.
414 * The lock is declared along with zone->lock because it is
415 * frequently read in proximity to zone->lock. It's good to
416 * give them a chance of being in the same cacheline.
418 unsigned long spanned_pages
; /* total size, including holes */
419 unsigned long present_pages
; /* amount of memory (excluding holes) */
422 * rarely used fields:
425 } ____cacheline_internodealigned_in_smp
;
428 ZONE_ALL_UNRECLAIMABLE
, /* all pages pinned */
429 ZONE_RECLAIM_LOCKED
, /* prevents concurrent reclaim */
430 ZONE_OOM_LOCKED
, /* zone is in OOM killer zonelist */
433 static inline void zone_set_flag(struct zone
*zone
, zone_flags_t flag
)
435 set_bit(flag
, &zone
->flags
);
438 static inline int zone_test_and_set_flag(struct zone
*zone
, zone_flags_t flag
)
440 return test_and_set_bit(flag
, &zone
->flags
);
443 static inline void zone_clear_flag(struct zone
*zone
, zone_flags_t flag
)
445 clear_bit(flag
, &zone
->flags
);
448 static inline int zone_is_all_unreclaimable(const struct zone
*zone
)
450 return test_bit(ZONE_ALL_UNRECLAIMABLE
, &zone
->flags
);
453 static inline int zone_is_reclaim_locked(const struct zone
*zone
)
455 return test_bit(ZONE_RECLAIM_LOCKED
, &zone
->flags
);
458 static inline int zone_is_oom_locked(const struct zone
*zone
)
460 return test_bit(ZONE_OOM_LOCKED
, &zone
->flags
);
464 * The "priority" of VM scanning is how much of the queues we will scan in one
465 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
466 * queues ("queue_length >> 12") during an aging round.
468 #define DEF_PRIORITY 12
470 /* Maximum number of zones on a zonelist */
471 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
476 * The NUMA zonelists are doubled becausse we need zonelists that restrict the
477 * allocations to a single node for GFP_THISNODE.
479 * [0] : Zonelist with fallback
480 * [1] : No fallback (GFP_THISNODE)
482 #define MAX_ZONELISTS 2
486 * We cache key information from each zonelist for smaller cache
487 * footprint when scanning for free pages in get_page_from_freelist().
489 * 1) The BITMAP fullzones tracks which zones in a zonelist have come
490 * up short of free memory since the last time (last_fullzone_zap)
491 * we zero'd fullzones.
492 * 2) The array z_to_n[] maps each zone in the zonelist to its node
493 * id, so that we can efficiently evaluate whether that node is
494 * set in the current tasks mems_allowed.
496 * Both fullzones and z_to_n[] are one-to-one with the zonelist,
497 * indexed by a zones offset in the zonelist zones[] array.
499 * The get_page_from_freelist() routine does two scans. During the
500 * first scan, we skip zones whose corresponding bit in 'fullzones'
501 * is set or whose corresponding node in current->mems_allowed (which
502 * comes from cpusets) is not set. During the second scan, we bypass
503 * this zonelist_cache, to ensure we look methodically at each zone.
505 * Once per second, we zero out (zap) fullzones, forcing us to
506 * reconsider nodes that might have regained more free memory.
507 * The field last_full_zap is the time we last zapped fullzones.
509 * This mechanism reduces the amount of time we waste repeatedly
510 * reexaming zones for free memory when they just came up low on
511 * memory momentarilly ago.
513 * The zonelist_cache struct members logically belong in struct
514 * zonelist. However, the mempolicy zonelists constructed for
515 * MPOL_BIND are intentionally variable length (and usually much
516 * shorter). A general purpose mechanism for handling structs with
517 * multiple variable length members is more mechanism than we want
518 * here. We resort to some special case hackery instead.
520 * The MPOL_BIND zonelists don't need this zonelist_cache (in good
521 * part because they are shorter), so we put the fixed length stuff
522 * at the front of the zonelist struct, ending in a variable length
523 * zones[], as is needed by MPOL_BIND.
525 * Then we put the optional zonelist cache on the end of the zonelist
526 * struct. This optional stuff is found by a 'zlcache_ptr' pointer in
527 * the fixed length portion at the front of the struct. This pointer
528 * both enables us to find the zonelist cache, and in the case of
529 * MPOL_BIND zonelists, (which will just set the zlcache_ptr to NULL)
530 * to know that the zonelist cache is not there.
532 * The end result is that struct zonelists come in two flavors:
533 * 1) The full, fixed length version, shown below, and
534 * 2) The custom zonelists for MPOL_BIND.
535 * The custom MPOL_BIND zonelists have a NULL zlcache_ptr and no zlcache.
537 * Even though there may be multiple CPU cores on a node modifying
538 * fullzones or last_full_zap in the same zonelist_cache at the same
539 * time, we don't lock it. This is just hint data - if it is wrong now
540 * and then, the allocator will still function, perhaps a bit slower.
544 struct zonelist_cache
{
545 unsigned short z_to_n
[MAX_ZONES_PER_ZONELIST
]; /* zone->nid */
546 DECLARE_BITMAP(fullzones
, MAX_ZONES_PER_ZONELIST
); /* zone full? */
547 unsigned long last_full_zap
; /* when last zap'd (jiffies) */
550 #define MAX_ZONELISTS 1
551 struct zonelist_cache
;
555 * This struct contains information about a zone in a zonelist. It is stored
556 * here to avoid dereferences into large structures and lookups of tables
559 struct zone
*zone
; /* Pointer to actual zone */
560 int zone_idx
; /* zone_idx(zoneref->zone) */
564 * One allocation request operates on a zonelist. A zonelist
565 * is a list of zones, the first one is the 'goal' of the
566 * allocation, the other zones are fallback zones, in decreasing
569 * If zlcache_ptr is not NULL, then it is just the address of zlcache,
570 * as explained above. If zlcache_ptr is NULL, there is no zlcache.
572 * To speed the reading of the zonelist, the zonerefs contain the zone index
573 * of the entry being read. Helper functions to access information given
574 * a struct zoneref are
576 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs
577 * zonelist_zone_idx() - Return the index of the zone for an entry
578 * zonelist_node_idx() - Return the index of the node for an entry
581 struct zonelist_cache
*zlcache_ptr
; // NULL or &zlcache
582 struct zoneref _zonerefs
[MAX_ZONES_PER_ZONELIST
+ 1];
584 struct zonelist_cache zlcache
; // optional ...
588 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
589 struct node_active_region
{
590 unsigned long start_pfn
;
591 unsigned long end_pfn
;
594 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
596 #ifndef CONFIG_DISCONTIGMEM
597 /* The array of struct pages - for discontigmem use pgdat->lmem_map */
598 extern struct page
*mem_map
;
602 * The pg_data_t structure is used in machines with CONFIG_DISCONTIGMEM
603 * (mostly NUMA machines?) to denote a higher-level memory zone than the
606 * On NUMA machines, each NUMA node would have a pg_data_t to describe
607 * it's memory layout.
609 * Memory statistics and page replacement data structures are maintained on a
613 typedef struct pglist_data
{
614 struct zone node_zones
[MAX_NR_ZONES
];
615 struct zonelist node_zonelists
[MAX_ZONELISTS
];
617 #ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */
618 struct page
*node_mem_map
;
619 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
620 struct page_cgroup
*node_page_cgroup
;
623 struct bootmem_data
*bdata
;
624 #ifdef CONFIG_MEMORY_HOTPLUG
626 * Must be held any time you expect node_start_pfn, node_present_pages
627 * or node_spanned_pages stay constant. Holding this will also
628 * guarantee that any pfn_valid() stays that way.
630 * Nests above zone->lock and zone->size_seqlock.
632 spinlock_t node_size_lock
;
634 unsigned long node_start_pfn
;
635 unsigned long node_present_pages
; /* total number of physical pages */
636 unsigned long node_spanned_pages
; /* total size of physical page
637 range, including holes */
639 wait_queue_head_t kswapd_wait
;
640 struct task_struct
*kswapd
;
641 int kswapd_max_order
;
644 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
645 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
646 #ifdef CONFIG_FLAT_NODE_MEM_MAP
647 #define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr))
649 #define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr))
651 #define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr))
653 #include <linux/memory_hotplug.h>
655 void get_zone_counts(unsigned long *active
, unsigned long *inactive
,
656 unsigned long *free
);
657 void build_all_zonelists(void);
658 void wakeup_kswapd(struct zone
*zone
, int order
);
659 int zone_watermark_ok(struct zone
*z
, int order
, unsigned long mark
,
660 int classzone_idx
, int alloc_flags
);
661 enum memmap_context
{
665 extern int init_currently_empty_zone(struct zone
*zone
, unsigned long start_pfn
,
667 enum memmap_context context
);
669 #ifdef CONFIG_HAVE_MEMORY_PRESENT
670 void memory_present(int nid
, unsigned long start
, unsigned long end
);
672 static inline void memory_present(int nid
, unsigned long start
, unsigned long end
) {}
675 #ifdef CONFIG_NEED_NODE_MEMMAP_SIZE
676 unsigned long __init
node_memmap_size_bytes(int, unsigned long, unsigned long);
680 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
682 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones)
684 static inline int populated_zone(struct zone
*zone
)
686 return (!!zone
->present_pages
);
689 extern int movable_zone
;
691 static inline int zone_movable_is_highmem(void)
693 #if defined(CONFIG_HIGHMEM) && defined(CONFIG_ARCH_POPULATES_NODE_MAP)
694 return movable_zone
== ZONE_HIGHMEM
;
700 static inline int is_highmem_idx(enum zone_type idx
)
702 #ifdef CONFIG_HIGHMEM
703 return (idx
== ZONE_HIGHMEM
||
704 (idx
== ZONE_MOVABLE
&& zone_movable_is_highmem()));
710 static inline int is_normal_idx(enum zone_type idx
)
712 return (idx
== ZONE_NORMAL
);
716 * is_highmem - helper function to quickly check if a struct zone is a
717 * highmem zone or not. This is an attempt to keep references
718 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
719 * @zone - pointer to struct zone variable
721 static inline int is_highmem(struct zone
*zone
)
723 #ifdef CONFIG_HIGHMEM
724 int zone_off
= (char *)zone
- (char *)zone
->zone_pgdat
->node_zones
;
725 return zone_off
== ZONE_HIGHMEM
* sizeof(*zone
) ||
726 (zone_off
== ZONE_MOVABLE
* sizeof(*zone
) &&
727 zone_movable_is_highmem());
733 static inline int is_normal(struct zone
*zone
)
735 return zone
== zone
->zone_pgdat
->node_zones
+ ZONE_NORMAL
;
738 static inline int is_dma32(struct zone
*zone
)
740 #ifdef CONFIG_ZONE_DMA32
741 return zone
== zone
->zone_pgdat
->node_zones
+ ZONE_DMA32
;
747 static inline int is_dma(struct zone
*zone
)
749 #ifdef CONFIG_ZONE_DMA
750 return zone
== zone
->zone_pgdat
->node_zones
+ ZONE_DMA
;
756 /* These two functions are used to setup the per zone pages min values */
758 int min_free_kbytes_sysctl_handler(struct ctl_table
*, int,
759 void __user
*, size_t *, loff_t
*);
760 extern int sysctl_lowmem_reserve_ratio
[MAX_NR_ZONES
-1];
761 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table
*, int,
762 void __user
*, size_t *, loff_t
*);
763 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table
*, int,
764 void __user
*, size_t *, loff_t
*);
765 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table
*, int,
766 void __user
*, size_t *, loff_t
*);
767 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table
*, int,
768 void __user
*, size_t *, loff_t
*);
770 extern int numa_zonelist_order_handler(struct ctl_table
*, int,
771 void __user
*, size_t *, loff_t
*);
772 extern char numa_zonelist_order
[];
773 #define NUMA_ZONELIST_ORDER_LEN 16 /* string buffer size */
775 #ifndef CONFIG_NEED_MULTIPLE_NODES
777 extern struct pglist_data contig_page_data
;
778 #define NODE_DATA(nid) (&contig_page_data)
779 #define NODE_MEM_MAP(nid) mem_map
781 #else /* CONFIG_NEED_MULTIPLE_NODES */
783 #include <asm/mmzone.h>
785 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
787 extern struct pglist_data
*first_online_pgdat(void);
788 extern struct pglist_data
*next_online_pgdat(struct pglist_data
*pgdat
);
789 extern struct zone
*next_zone(struct zone
*zone
);
792 * for_each_online_pgdat - helper macro to iterate over all online nodes
793 * @pgdat - pointer to a pg_data_t variable
795 #define for_each_online_pgdat(pgdat) \
796 for (pgdat = first_online_pgdat(); \
798 pgdat = next_online_pgdat(pgdat))
800 * for_each_zone - helper macro to iterate over all memory zones
801 * @zone - pointer to struct zone variable
803 * The user only needs to declare the zone variable, for_each_zone
806 #define for_each_zone(zone) \
807 for (zone = (first_online_pgdat())->node_zones; \
809 zone = next_zone(zone))
811 #define for_each_populated_zone(zone) \
812 for (zone = (first_online_pgdat())->node_zones; \
814 zone = next_zone(zone)) \
815 if (!populated_zone(zone)) \
819 static inline struct zone
*zonelist_zone(struct zoneref
*zoneref
)
821 return zoneref
->zone
;
824 static inline int zonelist_zone_idx(struct zoneref
*zoneref
)
826 return zoneref
->zone_idx
;
829 static inline int zonelist_node_idx(struct zoneref
*zoneref
)
832 /* zone_to_nid not available in this context */
833 return zoneref
->zone
->node
;
836 #endif /* CONFIG_NUMA */
840 * 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
841 * @z - The cursor used as a starting point for the search
842 * @highest_zoneidx - The zone index of the highest zone to return
843 * @nodes - An optional nodemask to filter the zonelist with
844 * @zone - The first suitable zone found is returned via this parameter
846 * This function returns the next zone at or below a given zone index that is
847 * within the allowed nodemask using a cursor as the starting point for the
848 * search. The zoneref returned is a cursor that represents the current zone
849 * being examined. It should be advanced by one before calling
850 * next_zones_zonelist again.
852 struct zoneref
*next_zones_zonelist(struct zoneref
*z
,
853 enum zone_type highest_zoneidx
,
858 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
859 * @zonelist - The zonelist to search for a suitable zone
860 * @highest_zoneidx - The zone index of the highest zone to return
861 * @nodes - An optional nodemask to filter the zonelist with
862 * @zone - The first suitable zone found is returned via this parameter
864 * This function returns the first zone at or below a given zone index that is
865 * within the allowed nodemask. The zoneref returned is a cursor that can be
866 * used to iterate the zonelist with next_zones_zonelist by advancing it by
867 * one before calling.
869 static inline struct zoneref
*first_zones_zonelist(struct zonelist
*zonelist
,
870 enum zone_type highest_zoneidx
,
874 return next_zones_zonelist(zonelist
->_zonerefs
, highest_zoneidx
, nodes
,
879 * 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
880 * @zone - The current zone in the iterator
881 * @z - The current pointer within zonelist->zones being iterated
882 * @zlist - The zonelist being iterated
883 * @highidx - The zone index of the highest zone to return
884 * @nodemask - Nodemask allowed by the allocator
886 * This iterator iterates though all zones at or below a given zone index and
887 * within a given nodemask
889 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
890 for (z = first_zones_zonelist(zlist, highidx, nodemask, &zone); \
892 z = next_zones_zonelist(++z, highidx, nodemask, &zone)) \
895 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
896 * @zone - The current zone in the iterator
897 * @z - The current pointer within zonelist->zones being iterated
898 * @zlist - The zonelist being iterated
899 * @highidx - The zone index of the highest zone to return
901 * This iterator iterates though all zones at or below a given zone index.
903 #define for_each_zone_zonelist(zone, z, zlist, highidx) \
904 for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL)
906 #ifdef CONFIG_SPARSEMEM
907 #include <asm/sparsemem.h>
910 #if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \
911 !defined(CONFIG_ARCH_POPULATES_NODE_MAP)
912 static inline unsigned long early_pfn_to_nid(unsigned long pfn
)
918 #ifdef CONFIG_FLATMEM
919 #define pfn_to_nid(pfn) (0)
922 #define pfn_to_section_nr(pfn) ((pfn) >> PFN_SECTION_SHIFT)
923 #define section_nr_to_pfn(sec) ((sec) << PFN_SECTION_SHIFT)
925 #ifdef CONFIG_SPARSEMEM
928 * SECTION_SHIFT #bits space required to store a section #
930 * PA_SECTION_SHIFT physical address to/from section number
931 * PFN_SECTION_SHIFT pfn to/from section number
933 #define SECTIONS_SHIFT (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS)
935 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS)
936 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
938 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT)
940 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT)
941 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1))
943 #define SECTION_BLOCKFLAGS_BITS \
944 ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS)
946 #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
947 #error Allocator MAX_ORDER exceeds SECTION_SIZE
954 * This is, logically, a pointer to an array of struct
955 * pages. However, it is stored with some other magic.
956 * (see sparse.c::sparse_init_one_section())
958 * Additionally during early boot we encode node id of
959 * the location of the section here to guide allocation.
960 * (see sparse.c::memory_present())
962 * Making it a UL at least makes someone do a cast
963 * before using it wrong.
965 unsigned long section_mem_map
;
967 /* See declaration of similar field in struct zone */
968 unsigned long *pageblock_flags
;
969 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
971 * If !SPARSEMEM, pgdat doesn't have page_cgroup pointer. We use
972 * section. (see memcontrol.h/page_cgroup.h about this.)
974 struct page_cgroup
*page_cgroup
;
979 #ifdef CONFIG_SPARSEMEM_EXTREME
980 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section))
982 #define SECTIONS_PER_ROOT 1
985 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
986 #define NR_SECTION_ROOTS (NR_MEM_SECTIONS / SECTIONS_PER_ROOT)
987 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1)
989 #ifdef CONFIG_SPARSEMEM_EXTREME
990 extern struct mem_section
*mem_section
[NR_SECTION_ROOTS
];
992 extern struct mem_section mem_section
[NR_SECTION_ROOTS
][SECTIONS_PER_ROOT
];
995 static inline struct mem_section
*__nr_to_section(unsigned long nr
)
997 if (!mem_section
[SECTION_NR_TO_ROOT(nr
)])
999 return &mem_section
[SECTION_NR_TO_ROOT(nr
)][nr
& SECTION_ROOT_MASK
];
1001 extern int __section_nr(struct mem_section
* ms
);
1002 extern unsigned long usemap_size(void);
1005 * We use the lower bits of the mem_map pointer to store
1006 * a little bit of information. There should be at least
1007 * 3 bits here due to 32-bit alignment.
1009 #define SECTION_MARKED_PRESENT (1UL<<0)
1010 #define SECTION_HAS_MEM_MAP (1UL<<1)
1011 #define SECTION_MAP_LAST_BIT (1UL<<2)
1012 #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1))
1013 #define SECTION_NID_SHIFT 2
1015 static inline struct page
*__section_mem_map_addr(struct mem_section
*section
)
1017 unsigned long map
= section
->section_mem_map
;
1018 map
&= SECTION_MAP_MASK
;
1019 return (struct page
*)map
;
1022 static inline int present_section(struct mem_section
*section
)
1024 return (section
&& (section
->section_mem_map
& SECTION_MARKED_PRESENT
));
1027 static inline int present_section_nr(unsigned long nr
)
1029 return present_section(__nr_to_section(nr
));
1032 static inline int valid_section(struct mem_section
*section
)
1034 return (section
&& (section
->section_mem_map
& SECTION_HAS_MEM_MAP
));
1037 static inline int valid_section_nr(unsigned long nr
)
1039 return valid_section(__nr_to_section(nr
));
1042 static inline struct mem_section
*__pfn_to_section(unsigned long pfn
)
1044 return __nr_to_section(pfn_to_section_nr(pfn
));
1047 static inline int pfn_valid(unsigned long pfn
)
1049 if (pfn_to_section_nr(pfn
) >= NR_MEM_SECTIONS
)
1051 return valid_section(__nr_to_section(pfn_to_section_nr(pfn
)));
1054 static inline int pfn_present(unsigned long pfn
)
1056 if (pfn_to_section_nr(pfn
) >= NR_MEM_SECTIONS
)
1058 return present_section(__nr_to_section(pfn_to_section_nr(pfn
)));
1062 * These are _only_ used during initialisation, therefore they
1063 * can use __initdata ... They could have names to indicate
1067 #define pfn_to_nid(pfn) \
1069 unsigned long __pfn_to_nid_pfn = (pfn); \
1070 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \
1073 #define pfn_to_nid(pfn) (0)
1076 #define early_pfn_valid(pfn) pfn_valid(pfn)
1077 void sparse_init(void);
1079 #define sparse_init() do {} while (0)
1080 #define sparse_index_init(_sec, _nid) do {} while (0)
1081 #endif /* CONFIG_SPARSEMEM */
1083 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1084 bool early_pfn_in_nid(unsigned long pfn
, int nid
);
1086 #define early_pfn_in_nid(pfn, nid) (1)
1089 #ifndef early_pfn_valid
1090 #define early_pfn_valid(pfn) (1)
1093 void memory_present(int nid
, unsigned long start
, unsigned long end
);
1094 unsigned long __init
node_memmap_size_bytes(int, unsigned long, unsigned long);
1097 * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we
1098 * need to check pfn validility within that MAX_ORDER_NR_PAGES block.
1099 * pfn_valid_within() should be used in this case; we optimise this away
1100 * when we have no holes within a MAX_ORDER_NR_PAGES block.
1102 #ifdef CONFIG_HOLES_IN_ZONE
1103 #define pfn_valid_within(pfn) pfn_valid(pfn)
1105 #define pfn_valid_within(pfn) (1)
1108 #ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
1110 * pfn_valid() is meant to be able to tell if a given PFN has valid memmap
1111 * associated with it or not. In FLATMEM, it is expected that holes always
1112 * have valid memmap as long as there is valid PFNs either side of the hole.
1113 * In SPARSEMEM, it is assumed that a valid section has a memmap for the
1116 * However, an ARM, and maybe other embedded architectures in the future
1117 * free memmap backing holes to save memory on the assumption the memmap is
1118 * never used. The page_zone linkages are then broken even though pfn_valid()
1119 * returns true. A walker of the full memmap must then do this additional
1120 * check to ensure the memmap they are looking at is sane by making sure
1121 * the zone and PFN linkages are still valid. This is expensive, but walkers
1122 * of the full memmap are extremely rare.
1124 int memmap_valid_within(unsigned long pfn
,
1125 struct page
*page
, struct zone
*zone
);
1127 static inline int memmap_valid_within(unsigned long pfn
,
1128 struct page
*page
, struct zone
*zone
)
1132 #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */
1134 #endif /* !__GENERATING_BOUNDS.H */
1135 #endif /* !__ASSEMBLY__ */
1136 #endif /* _LINUX_MMZONE_H */