kernel-ark/include/linux/mmzone.h
Christoph Lameter aa45484031 mm: page allocator: calculate a better estimate of NR_FREE_PAGES when memory is low and kswapd is awake
Ordinarily watermark checks are based on the vmstat NR_FREE_PAGES as it is
cheaper than scanning a number of lists.  To avoid synchronization
overhead, counter deltas are maintained on a per-cpu basis and drained
both periodically and when the delta is above a threshold.  On large CPU
systems, the difference between the estimated and real value of
NR_FREE_PAGES can be very high.  If NR_FREE_PAGES is much higher than
number of real free page in buddy, the VM can allocate pages below min
watermark, at worst reducing the real number of pages to zero.  Even if
the OOM killer kills some victim for freeing memory, it may not free
memory if the exit path requires a new page resulting in livelock.

This patch introduces a zone_page_state_snapshot() function (courtesy of
Christoph) that takes a slightly more accurate view of an arbitrary vmstat
counter.  It is used to read NR_FREE_PAGES while kswapd is awake to avoid
the watermark being accidentally broken.  The estimate is not perfect and
may result in cache line bounces but is expected to be lighter than the
IPI calls necessary to continually drain the per-cpu counters while kswapd
is awake.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-09 18:57:25 -07:00

1138 lines
35 KiB
C

#ifndef _LINUX_MMZONE_H
#define _LINUX_MMZONE_H
#ifndef __ASSEMBLY__
#ifndef __GENERATING_BOUNDS_H
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/wait.h>
#include <linux/bitops.h>
#include <linux/cache.h>
#include <linux/threads.h>
#include <linux/numa.h>
#include <linux/init.h>
#include <linux/seqlock.h>
#include <linux/nodemask.h>
#include <linux/pageblock-flags.h>
#include <generated/bounds.h>
#include <asm/atomic.h>
#include <asm/page.h>
/* Free memory management - zoned buddy allocator. */
#ifndef CONFIG_FORCE_MAX_ZONEORDER
#define MAX_ORDER 11
#else
#define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER
#endif
#define MAX_ORDER_NR_PAGES (1 << (MAX_ORDER - 1))
/*
* PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed
* costly to service. That is between allocation orders which should
* coelesce naturally under reasonable reclaim pressure and those which
* will not.
*/
#define PAGE_ALLOC_COSTLY_ORDER 3
#define MIGRATE_UNMOVABLE 0
#define MIGRATE_RECLAIMABLE 1
#define MIGRATE_MOVABLE 2
#define MIGRATE_PCPTYPES 3 /* the number of types on the pcp lists */
#define MIGRATE_RESERVE 3
#define MIGRATE_ISOLATE 4 /* can't allocate from here */
#define MIGRATE_TYPES 5
#define for_each_migratetype_order(order, type) \
for (order = 0; order < MAX_ORDER; order++) \
for (type = 0; type < MIGRATE_TYPES; type++)
extern int page_group_by_mobility_disabled;
static inline int get_pageblock_migratetype(struct page *page)
{
return get_pageblock_flags_group(page, PB_migrate, PB_migrate_end);
}
struct free_area {
struct list_head free_list[MIGRATE_TYPES];
unsigned long nr_free;
};
struct pglist_data;
/*
* zone->lock and zone->lru_lock are two of the hottest locks in the kernel.
* So add a wild amount of padding here to ensure that they fall into separate
* cachelines. There are very few zone structures in the machine, so space
* consumption is not a concern here.
*/
#if defined(CONFIG_SMP)
struct zone_padding {
char x[0];
} ____cacheline_internodealigned_in_smp;
#define ZONE_PADDING(name) struct zone_padding name;
#else
#define ZONE_PADDING(name)
#endif
enum zone_stat_item {
/* First 128 byte cacheline (assuming 64 bit words) */
NR_FREE_PAGES,
NR_LRU_BASE,
NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */
NR_ACTIVE_ANON, /* " " " " " */
NR_INACTIVE_FILE, /* " " " " " */
NR_ACTIVE_FILE, /* " " " " " */
NR_UNEVICTABLE, /* " " " " " */
NR_MLOCK, /* mlock()ed pages found and moved off LRU */
NR_ANON_PAGES, /* Mapped anonymous pages */
NR_FILE_MAPPED, /* pagecache pages mapped into pagetables.
only modified from process context */
NR_FILE_PAGES,
NR_FILE_DIRTY,
NR_WRITEBACK,
NR_SLAB_RECLAIMABLE,
NR_SLAB_UNRECLAIMABLE,
NR_PAGETABLE, /* used for pagetables */
NR_KERNEL_STACK,
/* Second 128 byte cacheline */
NR_UNSTABLE_NFS, /* NFS unstable pages */
NR_BOUNCE,
NR_VMSCAN_WRITE,
NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */
NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */
NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */
NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */
#ifdef CONFIG_NUMA
NUMA_HIT, /* allocated in intended node */
NUMA_MISS, /* allocated in non intended node */
NUMA_FOREIGN, /* was intended here, hit elsewhere */
NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */
NUMA_LOCAL, /* allocation from local node */
NUMA_OTHER, /* allocation from other node */
#endif
NR_VM_ZONE_STAT_ITEMS };
/*
* We do arithmetic on the LRU lists in various places in the code,
* so it is important to keep the active lists LRU_ACTIVE higher in
* the array than the corresponding inactive lists, and to keep
* the *_FILE lists LRU_FILE higher than the corresponding _ANON lists.
*
* This has to be kept in sync with the statistics in zone_stat_item
* above and the descriptions in vmstat_text in mm/vmstat.c
*/
#define LRU_BASE 0
#define LRU_ACTIVE 1
#define LRU_FILE 2
enum lru_list {
LRU_INACTIVE_ANON = LRU_BASE,
LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE,
LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE,
LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE,
LRU_UNEVICTABLE,
NR_LRU_LISTS
};
#define for_each_lru(l) for (l = 0; l < NR_LRU_LISTS; l++)
#define for_each_evictable_lru(l) for (l = 0; l <= LRU_ACTIVE_FILE; l++)
static inline int is_file_lru(enum lru_list l)
{
return (l == LRU_INACTIVE_FILE || l == LRU_ACTIVE_FILE);
}
static inline int is_active_lru(enum lru_list l)
{
return (l == LRU_ACTIVE_ANON || l == LRU_ACTIVE_FILE);
}
static inline int is_unevictable_lru(enum lru_list l)
{
return (l == LRU_UNEVICTABLE);
}
enum zone_watermarks {
WMARK_MIN,
WMARK_LOW,
WMARK_HIGH,
NR_WMARK
};
#define min_wmark_pages(z) (z->watermark[WMARK_MIN])
#define low_wmark_pages(z) (z->watermark[WMARK_LOW])
#define high_wmark_pages(z) (z->watermark[WMARK_HIGH])
struct per_cpu_pages {
int count; /* number of pages in the list */
int high; /* high watermark, emptying needed */
int batch; /* chunk size for buddy add/remove */
/* Lists of pages, one per migrate type stored on the pcp-lists */
struct list_head lists[MIGRATE_PCPTYPES];
};
struct per_cpu_pageset {
struct per_cpu_pages pcp;
#ifdef CONFIG_NUMA
s8 expire;
#endif
#ifdef CONFIG_SMP
s8 stat_threshold;
s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS];
#endif
};
#endif /* !__GENERATING_BOUNDS.H */
enum zone_type {
#ifdef CONFIG_ZONE_DMA
/*
* ZONE_DMA is used when there are devices that are not able
* to do DMA to all of addressable memory (ZONE_NORMAL). Then we
* carve out the portion of memory that is needed for these devices.
* The range is arch specific.
*
* Some examples
*
* Architecture Limit
* ---------------------------
* parisc, ia64, sparc <4G
* s390 <2G
* arm Various
* alpha Unlimited or 0-16MB.
*
* i386, x86_64 and multiple other arches
* <16M.
*/
ZONE_DMA,
#endif
#ifdef CONFIG_ZONE_DMA32
/*
* x86_64 needs two ZONE_DMAs because it supports devices that are
* only able to do DMA to the lower 16M but also 32 bit devices that
* can only do DMA areas below 4G.
*/
ZONE_DMA32,
#endif
/*
* Normal addressable memory is in ZONE_NORMAL. DMA operations can be
* performed on pages in ZONE_NORMAL if the DMA devices support
* transfers to all addressable memory.
*/
ZONE_NORMAL,
#ifdef CONFIG_HIGHMEM
/*
* A memory area that is only addressable by the kernel through
* mapping portions into its own address space. This is for example
* used by i386 to allow the kernel to address the memory beyond
* 900MB. The kernel will set up special mappings (page
* table entries on i386) for each page that the kernel needs to
* access.
*/
ZONE_HIGHMEM,
#endif
ZONE_MOVABLE,
__MAX_NR_ZONES
};
#ifndef __GENERATING_BOUNDS_H
/*
* When a memory allocation must conform to specific limitations (such
* as being suitable for DMA) the caller will pass in hints to the
* allocator in the gfp_mask, in the zone modifier bits. These bits
* are used to select a priority ordered list of memory zones which
* match the requested limits. See gfp_zone() in include/linux/gfp.h
*/
#if MAX_NR_ZONES < 2
#define ZONES_SHIFT 0
#elif MAX_NR_ZONES <= 2
#define ZONES_SHIFT 1
#elif MAX_NR_ZONES <= 4
#define ZONES_SHIFT 2
#else
#error ZONES_SHIFT -- too many zones configured adjust calculation
#endif
struct zone_reclaim_stat {
/*
* The pageout code in vmscan.c keeps track of how many of the
* mem/swap backed and file backed pages are refeferenced.
* The higher the rotated/scanned ratio, the more valuable
* that cache is.
*
* The anon LRU stats live in [0], file LRU stats in [1]
*/
unsigned long recent_rotated[2];
unsigned long recent_scanned[2];
/*
* accumulated for batching
*/
unsigned long nr_saved_scan[NR_LRU_LISTS];
};
struct zone {
/* Fields commonly accessed by the page allocator */
/* zone watermarks, access with *_wmark_pages(zone) macros */
unsigned long watermark[NR_WMARK];
/*
* When free pages are below this point, additional steps are taken
* when reading the number of free pages to avoid per-cpu counter
* drift allowing watermarks to be breached
*/
unsigned long percpu_drift_mark;
/*
* We don't know if the memory that we're going to allocate will be freeable
* or/and it will be released eventually, so to avoid totally wasting several
* GB of ram we must reserve some of the lower zone memory (otherwise we risk
* to run OOM on the lower zones despite there's tons of freeable ram
* on the higher zones). This array is recalculated at runtime if the
* sysctl_lowmem_reserve_ratio sysctl changes.
*/
unsigned long lowmem_reserve[MAX_NR_ZONES];
#ifdef CONFIG_NUMA
int node;
/*
* zone reclaim becomes active if more unmapped pages exist.
*/
unsigned long min_unmapped_pages;
unsigned long min_slab_pages;
#endif
struct per_cpu_pageset __percpu *pageset;
/*
* free areas of different sizes
*/
spinlock_t lock;
int all_unreclaimable; /* All pages pinned */
#ifdef CONFIG_MEMORY_HOTPLUG
/* see spanned/present_pages for more description */
seqlock_t span_seqlock;
#endif
struct free_area free_area[MAX_ORDER];
#ifndef CONFIG_SPARSEMEM
/*
* Flags for a pageblock_nr_pages block. See pageblock-flags.h.
* In SPARSEMEM, this map is stored in struct mem_section
*/
unsigned long *pageblock_flags;
#endif /* CONFIG_SPARSEMEM */
#ifdef CONFIG_COMPACTION
/*
* On compaction failure, 1<<compact_defer_shift compactions
* are skipped before trying again. The number attempted since
* last failure is tracked with compact_considered.
*/
unsigned int compact_considered;
unsigned int compact_defer_shift;
#endif
ZONE_PADDING(_pad1_)
/* Fields commonly accessed by the page reclaim scanner */
spinlock_t lru_lock;
struct zone_lru {
struct list_head list;
} lru[NR_LRU_LISTS];
struct zone_reclaim_stat reclaim_stat;
unsigned long pages_scanned; /* since last reclaim */
unsigned long flags; /* zone flags, see below */
/* Zone statistics */
atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
/*
* The target ratio of ACTIVE_ANON to INACTIVE_ANON pages on
* this zone's LRU. Maintained by the pageout code.
*/
unsigned int inactive_ratio;
ZONE_PADDING(_pad2_)
/* Rarely used or read-mostly fields */
/*
* wait_table -- the array holding the hash table
* wait_table_hash_nr_entries -- the size of the hash table array
* wait_table_bits -- wait_table_size == (1 << wait_table_bits)
*
* The purpose of all these is to keep track of the people
* waiting for a page to become available and make them
* runnable again when possible. The trouble is that this
* consumes a lot of space, especially when so few things
* wait on pages at a given time. So instead of using
* per-page waitqueues, we use a waitqueue hash table.
*
* The bucket discipline is to sleep on the same queue when
* colliding and wake all in that wait queue when removing.
* When something wakes, it must check to be sure its page is
* truly available, a la thundering herd. The cost of a
* collision is great, but given the expected load of the
* table, they should be so rare as to be outweighed by the
* benefits from the saved space.
*
* __wait_on_page_locked() and unlock_page() in mm/filemap.c, are the
* primary users of these fields, and in mm/page_alloc.c
* free_area_init_core() performs the initialization of them.
*/
wait_queue_head_t * wait_table;
unsigned long wait_table_hash_nr_entries;
unsigned long wait_table_bits;
/*
* Discontig memory support fields.
*/
struct pglist_data *zone_pgdat;
/* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
unsigned long zone_start_pfn;
/*
* zone_start_pfn, spanned_pages and present_pages are all
* protected by span_seqlock. It is a seqlock because it has
* to be read outside of zone->lock, and it is done in the main
* allocator path. But, it is written quite infrequently.
*
* The lock is declared along with zone->lock because it is
* frequently read in proximity to zone->lock. It's good to
* give them a chance of being in the same cacheline.
*/
unsigned long spanned_pages; /* total size, including holes */
unsigned long present_pages; /* amount of memory (excluding holes) */
/*
* rarely used fields:
*/
const char *name;
} ____cacheline_internodealigned_in_smp;
typedef enum {
ZONE_RECLAIM_LOCKED, /* prevents concurrent reclaim */
ZONE_OOM_LOCKED, /* zone is in OOM killer zonelist */
} zone_flags_t;
static inline void zone_set_flag(struct zone *zone, zone_flags_t flag)
{
set_bit(flag, &zone->flags);
}
static inline int zone_test_and_set_flag(struct zone *zone, zone_flags_t flag)
{
return test_and_set_bit(flag, &zone->flags);
}
static inline void zone_clear_flag(struct zone *zone, zone_flags_t flag)
{
clear_bit(flag, &zone->flags);
}
static inline int zone_is_reclaim_locked(const struct zone *zone)
{
return test_bit(ZONE_RECLAIM_LOCKED, &zone->flags);
}
static inline int zone_is_oom_locked(const struct zone *zone)
{
return test_bit(ZONE_OOM_LOCKED, &zone->flags);
}
#ifdef CONFIG_SMP
unsigned long zone_nr_free_pages(struct zone *zone);
#else
#define zone_nr_free_pages(zone) zone_page_state(zone, NR_FREE_PAGES)
#endif /* CONFIG_SMP */
/*
* The "priority" of VM scanning is how much of the queues we will scan in one
* go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
* queues ("queue_length >> 12") during an aging round.
*/
#define DEF_PRIORITY 12
/* Maximum number of zones on a zonelist */
#define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
#ifdef CONFIG_NUMA
/*
* The NUMA zonelists are doubled becausse we need zonelists that restrict the
* allocations to a single node for GFP_THISNODE.
*
* [0] : Zonelist with fallback
* [1] : No fallback (GFP_THISNODE)
*/
#define MAX_ZONELISTS 2
/*
* We cache key information from each zonelist for smaller cache
* footprint when scanning for free pages in get_page_from_freelist().
*
* 1) The BITMAP fullzones tracks which zones in a zonelist have come
* up short of free memory since the last time (last_fullzone_zap)
* we zero'd fullzones.
* 2) The array z_to_n[] maps each zone in the zonelist to its node
* id, so that we can efficiently evaluate whether that node is
* set in the current tasks mems_allowed.
*
* Both fullzones and z_to_n[] are one-to-one with the zonelist,
* indexed by a zones offset in the zonelist zones[] array.
*
* The get_page_from_freelist() routine does two scans. During the
* first scan, we skip zones whose corresponding bit in 'fullzones'
* is set or whose corresponding node in current->mems_allowed (which
* comes from cpusets) is not set. During the second scan, we bypass
* this zonelist_cache, to ensure we look methodically at each zone.
*
* Once per second, we zero out (zap) fullzones, forcing us to
* reconsider nodes that might have regained more free memory.
* The field last_full_zap is the time we last zapped fullzones.
*
* This mechanism reduces the amount of time we waste repeatedly
* reexaming zones for free memory when they just came up low on
* memory momentarilly ago.
*
* The zonelist_cache struct members logically belong in struct
* zonelist. However, the mempolicy zonelists constructed for
* MPOL_BIND are intentionally variable length (and usually much
* shorter). A general purpose mechanism for handling structs with
* multiple variable length members is more mechanism than we want
* here. We resort to some special case hackery instead.
*
* The MPOL_BIND zonelists don't need this zonelist_cache (in good
* part because they are shorter), so we put the fixed length stuff
* at the front of the zonelist struct, ending in a variable length
* zones[], as is needed by MPOL_BIND.
*
* Then we put the optional zonelist cache on the end of the zonelist
* struct. This optional stuff is found by a 'zlcache_ptr' pointer in
* the fixed length portion at the front of the struct. This pointer
* both enables us to find the zonelist cache, and in the case of
* MPOL_BIND zonelists, (which will just set the zlcache_ptr to NULL)
* to know that the zonelist cache is not there.
*
* The end result is that struct zonelists come in two flavors:
* 1) The full, fixed length version, shown below, and
* 2) The custom zonelists for MPOL_BIND.
* The custom MPOL_BIND zonelists have a NULL zlcache_ptr and no zlcache.
*
* Even though there may be multiple CPU cores on a node modifying
* fullzones or last_full_zap in the same zonelist_cache at the same
* time, we don't lock it. This is just hint data - if it is wrong now
* and then, the allocator will still function, perhaps a bit slower.
*/
struct zonelist_cache {
unsigned short z_to_n[MAX_ZONES_PER_ZONELIST]; /* zone->nid */
DECLARE_BITMAP(fullzones, MAX_ZONES_PER_ZONELIST); /* zone full? */
unsigned long last_full_zap; /* when last zap'd (jiffies) */
};
#else
#define MAX_ZONELISTS 1
struct zonelist_cache;
#endif
/*
* This struct contains information about a zone in a zonelist. It is stored
* here to avoid dereferences into large structures and lookups of tables
*/
struct zoneref {
struct zone *zone; /* Pointer to actual zone */
int zone_idx; /* zone_idx(zoneref->zone) */
};
/*
* One allocation request operates on a zonelist. A zonelist
* is a list of zones, the first one is the 'goal' of the
* allocation, the other zones are fallback zones, in decreasing
* priority.
*
* If zlcache_ptr is not NULL, then it is just the address of zlcache,
* as explained above. If zlcache_ptr is NULL, there is no zlcache.
* *
* To speed the reading of the zonelist, the zonerefs contain the zone index
* of the entry being read. Helper functions to access information given
* a struct zoneref are
*
* zonelist_zone() - Return the struct zone * for an entry in _zonerefs
* zonelist_zone_idx() - Return the index of the zone for an entry
* zonelist_node_idx() - Return the index of the node for an entry
*/
struct zonelist {
struct zonelist_cache *zlcache_ptr; // NULL or &zlcache
struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1];
#ifdef CONFIG_NUMA
struct zonelist_cache zlcache; // optional ...
#endif
};
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
struct node_active_region {
unsigned long start_pfn;
unsigned long end_pfn;
int nid;
};
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
#ifndef CONFIG_DISCONTIGMEM
/* The array of struct pages - for discontigmem use pgdat->lmem_map */
extern struct page *mem_map;
#endif
/*
* The pg_data_t structure is used in machines with CONFIG_DISCONTIGMEM
* (mostly NUMA machines?) to denote a higher-level memory zone than the
* zone denotes.
*
* On NUMA machines, each NUMA node would have a pg_data_t to describe
* it's memory layout.
*
* Memory statistics and page replacement data structures are maintained on a
* per-zone basis.
*/
struct bootmem_data;
typedef struct pglist_data {
struct zone node_zones[MAX_NR_ZONES];
struct zonelist node_zonelists[MAX_ZONELISTS];
int nr_zones;
#ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */
struct page *node_mem_map;
#ifdef CONFIG_CGROUP_MEM_RES_CTLR
struct page_cgroup *node_page_cgroup;
#endif
#endif
#ifndef CONFIG_NO_BOOTMEM
struct bootmem_data *bdata;
#endif
#ifdef CONFIG_MEMORY_HOTPLUG
/*
* Must be held any time you expect node_start_pfn, node_present_pages
* or node_spanned_pages stay constant. Holding this will also
* guarantee that any pfn_valid() stays that way.
*
* Nests above zone->lock and zone->size_seqlock.
*/
spinlock_t node_size_lock;
#endif
unsigned long node_start_pfn;
unsigned long node_present_pages; /* total number of physical pages */
unsigned long node_spanned_pages; /* total size of physical page
range, including holes */
int node_id;
wait_queue_head_t kswapd_wait;
struct task_struct *kswapd;
int kswapd_max_order;
} pg_data_t;
#define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
#define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
#ifdef CONFIG_FLAT_NODE_MEM_MAP
#define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr))
#else
#define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr))
#endif
#define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr))
#include <linux/memory_hotplug.h>
extern struct mutex zonelists_mutex;
void build_all_zonelists(void *data);
void wakeup_kswapd(struct zone *zone, int order);
int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
int classzone_idx, int alloc_flags);
enum memmap_context {
MEMMAP_EARLY,
MEMMAP_HOTPLUG,
};
extern int init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
unsigned long size,
enum memmap_context context);
#ifdef CONFIG_HAVE_MEMORY_PRESENT
void memory_present(int nid, unsigned long start, unsigned long end);
#else
static inline void memory_present(int nid, unsigned long start, unsigned long end) {}
#endif
#ifdef CONFIG_HAVE_MEMORYLESS_NODES
int local_memory_node(int node_id);
#else
static inline int local_memory_node(int node_id) { return node_id; };
#endif
#ifdef CONFIG_NEED_NODE_MEMMAP_SIZE
unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
#endif
/*
* zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
*/
#define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones)
static inline int populated_zone(struct zone *zone)
{
return (!!zone->present_pages);
}
extern int movable_zone;
static inline int zone_movable_is_highmem(void)
{
#if defined(CONFIG_HIGHMEM) && defined(CONFIG_ARCH_POPULATES_NODE_MAP)
return movable_zone == ZONE_HIGHMEM;
#else
return 0;
#endif
}
static inline int is_highmem_idx(enum zone_type idx)
{
#ifdef CONFIG_HIGHMEM
return (idx == ZONE_HIGHMEM ||
(idx == ZONE_MOVABLE && zone_movable_is_highmem()));
#else
return 0;
#endif
}
static inline int is_normal_idx(enum zone_type idx)
{
return (idx == ZONE_NORMAL);
}
/**
* is_highmem - helper function to quickly check if a struct zone is a
* highmem zone or not. This is an attempt to keep references
* to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
* @zone - pointer to struct zone variable
*/
static inline int is_highmem(struct zone *zone)
{
#ifdef CONFIG_HIGHMEM
int zone_off = (char *)zone - (char *)zone->zone_pgdat->node_zones;
return zone_off == ZONE_HIGHMEM * sizeof(*zone) ||
(zone_off == ZONE_MOVABLE * sizeof(*zone) &&
zone_movable_is_highmem());
#else
return 0;
#endif
}
static inline int is_normal(struct zone *zone)
{
return zone == zone->zone_pgdat->node_zones + ZONE_NORMAL;
}
static inline int is_dma32(struct zone *zone)
{
#ifdef CONFIG_ZONE_DMA32
return zone == zone->zone_pgdat->node_zones + ZONE_DMA32;
#else
return 0;
#endif
}
static inline int is_dma(struct zone *zone)
{
#ifdef CONFIG_ZONE_DMA
return zone == zone->zone_pgdat->node_zones + ZONE_DMA;
#else
return 0;
#endif
}
/* These two functions are used to setup the per zone pages min values */
struct ctl_table;
int min_free_kbytes_sysctl_handler(struct ctl_table *, int,
void __user *, size_t *, loff_t *);
extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1];
int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int,
void __user *, size_t *, loff_t *);
int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int,
void __user *, size_t *, loff_t *);
int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int,
void __user *, size_t *, loff_t *);
int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int,
void __user *, size_t *, loff_t *);
extern int numa_zonelist_order_handler(struct ctl_table *, int,
void __user *, size_t *, loff_t *);
extern char numa_zonelist_order[];
#define NUMA_ZONELIST_ORDER_LEN 16 /* string buffer size */
#ifndef CONFIG_NEED_MULTIPLE_NODES
extern struct pglist_data contig_page_data;
#define NODE_DATA(nid) (&contig_page_data)
#define NODE_MEM_MAP(nid) mem_map
#else /* CONFIG_NEED_MULTIPLE_NODES */
#include <asm/mmzone.h>
#endif /* !CONFIG_NEED_MULTIPLE_NODES */
extern struct pglist_data *first_online_pgdat(void);
extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
extern struct zone *next_zone(struct zone *zone);
/**
* for_each_online_pgdat - helper macro to iterate over all online nodes
* @pgdat - pointer to a pg_data_t variable
*/
#define for_each_online_pgdat(pgdat) \
for (pgdat = first_online_pgdat(); \
pgdat; \
pgdat = next_online_pgdat(pgdat))
/**
* for_each_zone - helper macro to iterate over all memory zones
* @zone - pointer to struct zone variable
*
* The user only needs to declare the zone variable, for_each_zone
* fills it in.
*/
#define for_each_zone(zone) \
for (zone = (first_online_pgdat())->node_zones; \
zone; \
zone = next_zone(zone))
#define for_each_populated_zone(zone) \
for (zone = (first_online_pgdat())->node_zones; \
zone; \
zone = next_zone(zone)) \
if (!populated_zone(zone)) \
; /* do nothing */ \
else
static inline struct zone *zonelist_zone(struct zoneref *zoneref)
{
return zoneref->zone;
}
static inline int zonelist_zone_idx(struct zoneref *zoneref)
{
return zoneref->zone_idx;
}
static inline int zonelist_node_idx(struct zoneref *zoneref)
{
#ifdef CONFIG_NUMA
/* zone_to_nid not available in this context */
return zoneref->zone->node;
#else
return 0;
#endif /* CONFIG_NUMA */
}
/**
* 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
* @z - The cursor used as a starting point for the search
* @highest_zoneidx - The zone index of the highest zone to return
* @nodes - An optional nodemask to filter the zonelist with
* @zone - The first suitable zone found is returned via this parameter
*
* This function returns the next zone at or below a given zone index that is
* within the allowed nodemask using a cursor as the starting point for the
* search. The zoneref returned is a cursor that represents the current zone
* being examined. It should be advanced by one before calling
* next_zones_zonelist again.
*/
struct zoneref *next_zones_zonelist(struct zoneref *z,
enum zone_type highest_zoneidx,
nodemask_t *nodes,
struct zone **zone);
/**
* first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
* @zonelist - The zonelist to search for a suitable zone
* @highest_zoneidx - The zone index of the highest zone to return
* @nodes - An optional nodemask to filter the zonelist with
* @zone - The first suitable zone found is returned via this parameter
*
* This function returns the first zone at or below a given zone index that is
* within the allowed nodemask. The zoneref returned is a cursor that can be
* used to iterate the zonelist with next_zones_zonelist by advancing it by
* one before calling.
*/
static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
enum zone_type highest_zoneidx,
nodemask_t *nodes,
struct zone **zone)
{
return next_zones_zonelist(zonelist->_zonerefs, highest_zoneidx, nodes,
zone);
}
/**
* 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
* @zone - The current zone in the iterator
* @z - The current pointer within zonelist->zones being iterated
* @zlist - The zonelist being iterated
* @highidx - The zone index of the highest zone to return
* @nodemask - Nodemask allowed by the allocator
*
* This iterator iterates though all zones at or below a given zone index and
* within a given nodemask
*/
#define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
for (z = first_zones_zonelist(zlist, highidx, nodemask, &zone); \
zone; \
z = next_zones_zonelist(++z, highidx, nodemask, &zone)) \
/**
* for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
* @zone - The current zone in the iterator
* @z - The current pointer within zonelist->zones being iterated
* @zlist - The zonelist being iterated
* @highidx - The zone index of the highest zone to return
*
* This iterator iterates though all zones at or below a given zone index.
*/
#define for_each_zone_zonelist(zone, z, zlist, highidx) \
for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL)
#ifdef CONFIG_SPARSEMEM
#include <asm/sparsemem.h>
#endif
#if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \
!defined(CONFIG_ARCH_POPULATES_NODE_MAP)
static inline unsigned long early_pfn_to_nid(unsigned long pfn)
{
return 0;
}
#endif
#ifdef CONFIG_FLATMEM
#define pfn_to_nid(pfn) (0)
#endif
#define pfn_to_section_nr(pfn) ((pfn) >> PFN_SECTION_SHIFT)
#define section_nr_to_pfn(sec) ((sec) << PFN_SECTION_SHIFT)
#ifdef CONFIG_SPARSEMEM
/*
* SECTION_SHIFT #bits space required to store a section #
*
* PA_SECTION_SHIFT physical address to/from section number
* PFN_SECTION_SHIFT pfn to/from section number
*/
#define SECTIONS_SHIFT (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS)
#define PA_SECTION_SHIFT (SECTION_SIZE_BITS)
#define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
#define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT)
#define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT)
#define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1))
#define SECTION_BLOCKFLAGS_BITS \
((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS)
#if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
#error Allocator MAX_ORDER exceeds SECTION_SIZE
#endif
struct page;
struct page_cgroup;
struct mem_section {
/*
* This is, logically, a pointer to an array of struct
* pages. However, it is stored with some other magic.
* (see sparse.c::sparse_init_one_section())
*
* Additionally during early boot we encode node id of
* the location of the section here to guide allocation.
* (see sparse.c::memory_present())
*
* Making it a UL at least makes someone do a cast
* before using it wrong.
*/
unsigned long section_mem_map;
/* See declaration of similar field in struct zone */
unsigned long *pageblock_flags;
#ifdef CONFIG_CGROUP_MEM_RES_CTLR
/*
* If !SPARSEMEM, pgdat doesn't have page_cgroup pointer. We use
* section. (see memcontrol.h/page_cgroup.h about this.)
*/
struct page_cgroup *page_cgroup;
unsigned long pad;
#endif
};
#ifdef CONFIG_SPARSEMEM_EXTREME
#define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section))
#else
#define SECTIONS_PER_ROOT 1
#endif
#define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
#define NR_SECTION_ROOTS DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT)
#define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1)
#ifdef CONFIG_SPARSEMEM_EXTREME
extern struct mem_section *mem_section[NR_SECTION_ROOTS];
#else
extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
#endif
static inline struct mem_section *__nr_to_section(unsigned long nr)
{
if (!mem_section[SECTION_NR_TO_ROOT(nr)])
return NULL;
return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];
}
extern int __section_nr(struct mem_section* ms);
extern unsigned long usemap_size(void);
/*
* We use the lower bits of the mem_map pointer to store
* a little bit of information. There should be at least
* 3 bits here due to 32-bit alignment.
*/
#define SECTION_MARKED_PRESENT (1UL<<0)
#define SECTION_HAS_MEM_MAP (1UL<<1)
#define SECTION_MAP_LAST_BIT (1UL<<2)
#define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1))
#define SECTION_NID_SHIFT 2
static inline struct page *__section_mem_map_addr(struct mem_section *section)
{
unsigned long map = section->section_mem_map;
map &= SECTION_MAP_MASK;
return (struct page *)map;
}
static inline int present_section(struct mem_section *section)
{
return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
}
static inline int present_section_nr(unsigned long nr)
{
return present_section(__nr_to_section(nr));
}
static inline int valid_section(struct mem_section *section)
{
return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
}
static inline int valid_section_nr(unsigned long nr)
{
return valid_section(__nr_to_section(nr));
}
static inline struct mem_section *__pfn_to_section(unsigned long pfn)
{
return __nr_to_section(pfn_to_section_nr(pfn));
}
static inline int pfn_valid(unsigned long pfn)
{
if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
return 0;
return valid_section(__nr_to_section(pfn_to_section_nr(pfn)));
}
static inline int pfn_present(unsigned long pfn)
{
if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
return 0;
return present_section(__nr_to_section(pfn_to_section_nr(pfn)));
}
/*
* These are _only_ used during initialisation, therefore they
* can use __initdata ... They could have names to indicate
* this restriction.
*/
#ifdef CONFIG_NUMA
#define pfn_to_nid(pfn) \
({ \
unsigned long __pfn_to_nid_pfn = (pfn); \
page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \
})
#else
#define pfn_to_nid(pfn) (0)
#endif
#define early_pfn_valid(pfn) pfn_valid(pfn)
void sparse_init(void);
#else
#define sparse_init() do {} while (0)
#define sparse_index_init(_sec, _nid) do {} while (0)
#endif /* CONFIG_SPARSEMEM */
#ifdef CONFIG_NODES_SPAN_OTHER_NODES
bool early_pfn_in_nid(unsigned long pfn, int nid);
#else
#define early_pfn_in_nid(pfn, nid) (1)
#endif
#ifndef early_pfn_valid
#define early_pfn_valid(pfn) (1)
#endif
void memory_present(int nid, unsigned long start, unsigned long end);
unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
/*
* If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we
* need to check pfn validility within that MAX_ORDER_NR_PAGES block.
* pfn_valid_within() should be used in this case; we optimise this away
* when we have no holes within a MAX_ORDER_NR_PAGES block.
*/
#ifdef CONFIG_HOLES_IN_ZONE
#define pfn_valid_within(pfn) pfn_valid(pfn)
#else
#define pfn_valid_within(pfn) (1)
#endif
#ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
/*
* pfn_valid() is meant to be able to tell if a given PFN has valid memmap
* associated with it or not. In FLATMEM, it is expected that holes always
* have valid memmap as long as there is valid PFNs either side of the hole.
* In SPARSEMEM, it is assumed that a valid section has a memmap for the
* entire section.
*
* However, an ARM, and maybe other embedded architectures in the future
* free memmap backing holes to save memory on the assumption the memmap is
* never used. The page_zone linkages are then broken even though pfn_valid()
* returns true. A walker of the full memmap must then do this additional
* check to ensure the memmap they are looking at is sane by making sure
* the zone and PFN linkages are still valid. This is expensive, but walkers
* of the full memmap are extremely rare.
*/
int memmap_valid_within(unsigned long pfn,
struct page *page, struct zone *zone);
#else
static inline int memmap_valid_within(unsigned long pfn,
struct page *page, struct zone *zone)
{
return 1;
}
#endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */
#endif /* !__GENERATING_BOUNDS.H */
#endif /* !__ASSEMBLY__ */
#endif /* _LINUX_MMZONE_H */