[net-next-2.6.git] / include / linux / swap.h

#ifndef _LINUX_SWAP_H
#define _LINUX_SWAP_H

#include <linux/spinlock.h>
#include <linux/linkage.h>
#include <linux/mmzone.h>
#include <linux/list.h>
#include <linux/memcontrol.h>
#include <linux/sched.h>
#include <linux/node.h>

#include <asm/atomic.h>
#include <asm/page.h>

struct notifier_block;

struct bio;

#define SWAP_FLAG_PREFER	0x8000	/* set if swap priority specified */
#define SWAP_FLAG_PRIO_MASK	0x7fff
#define SWAP_FLAG_PRIO_SHIFT	0

static inline int current_is_kswapd(void)
{
	return current->flags & PF_KSWAPD;
}

/*
 * MAX_SWAPFILES defines the maximum number of swaptypes: things which can
 * be swapped to.  The swap type and the offset into that swap type are
 * encoded into pte's and into pgoff_t's in the swapcache.  Using five bits
 * for the type means that the maximum number of swapcache pages is 27 bits
 * on 32-bit-pgoff_t architectures.  And that assumes that the architecture packs
 * the type/offset into the pte as 5/27 as well.
 */
#define MAX_SWAPFILES_SHIFT	5

/*
 * Use some of the swap files numbers for other purposes. This
 * is a convenient way to hook into the VM to trigger special
 * actions on faults.
 */

/*
 * NUMA node memory migration support
 */
#ifdef CONFIG_MIGRATION
#define SWP_MIGRATION_NUM 2
#define SWP_MIGRATION_READ	(MAX_SWAPFILES + SWP_HWPOISON_NUM)
#define SWP_MIGRATION_WRITE	(MAX_SWAPFILES + SWP_HWPOISON_NUM + 1)
#else
#define SWP_MIGRATION_NUM 0
#endif

/*
 * Handling of hardware poisoned pages with memory corruption.
 */
#ifdef CONFIG_MEMORY_FAILURE
#define SWP_HWPOISON_NUM 1
#define SWP_HWPOISON		MAX_SWAPFILES
#else
#define SWP_HWPOISON_NUM 0
#endif

#define MAX_SWAPFILES \
	((1 << MAX_SWAPFILES_SHIFT) - SWP_MIGRATION_NUM - SWP_HWPOISON_NUM)

/*
 * Magic header for a swap area. The first part of the union is
 * what the swap magic looks like for the old (limited to 128MB)
 * swap area format, the second part of the union adds - in the
 * old reserved area - some extra information. Note that the first
 * kilobyte is reserved for boot loader or disk label stuff...
 *
 * Having the magic at the end of the PAGE_SIZE makes detecting swap
 * areas somewhat tricky on machines that support multiple page sizes.
 * For 2.5 we'll probably want to move the magic to just beyond the
 * bootbits...
 */
union swap_header {
	struct {
		char reserved[PAGE_SIZE - 10];
		char magic[10];			/* SWAP-SPACE or SWAPSPACE2 */
	} magic;
	struct {
		char		bootbits[1024];	/* Space for disklabel etc. */
		__u32		version;
		__u32		last_page;
		__u32		nr_badpages;
		unsigned char	sws_uuid[16];
		unsigned char	sws_volume[16];
		__u32		padding[117];
		__u32		badpages[1];
	} info;
};

 /* A swap entry has to fit into a "unsigned long", as
  * the entry is hidden in the "index" field of the
  * swapper address space.
  */
typedef struct {
	unsigned long val;
} swp_entry_t;

/*
 * current->reclaim_state points to one of these when a task is running
 * memory reclaim
 */
struct reclaim_state {
	unsigned long reclaimed_slab;
};

#ifdef __KERNEL__

struct address_space;
struct sysinfo;
struct writeback_control;
struct zone;

/*
 * A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of
 * disk blocks.  A list of swap extents maps the entire swapfile.  (Where the
 * term `swapfile' refers to either a blockdevice or an IS_REG file.  Apart
 * from setup, they're handled identically.
 *
 * We always assume that blocks are of size PAGE_SIZE.
 */
struct swap_extent {
	struct list_head list;
	pgoff_t start_page;
	pgoff_t nr_pages;
	sector_t start_block;
};

/*
 * Max bad pages in the new format..
 */
#define __swapoffset(x) ((unsigned long)&((union swap_header *)0)->x)
#define MAX_SWAP_BADPAGES \
	((__swapoffset(magic.magic) - __swapoffset(info.badpages)) / sizeof(int))

enum {
	SWP_USED	= (1 << 0),	/* is slot in swap_info[] used? */
	SWP_WRITEOK	= (1 << 1),	/* ok to write to this swap?	*/
	SWP_DISCARDABLE = (1 << 2),	/* blkdev supports discard */
	SWP_DISCARDING	= (1 << 3),	/* now discarding a free cluster */
	SWP_SOLIDSTATE	= (1 << 4),	/* blkdev seeks are cheap */
					/* add others here before... */
	SWP_SCANNING	= (1 << 8),	/* refcount in scan_swap_map */
};

#define SWAP_CLUSTER_MAX 32

#define SWAP_MAP_MAX	0x7ffe
#define SWAP_MAP_BAD	0x7fff
#define SWAP_HAS_CACHE  0x8000		/* There is a swap cache of entry. */
#define SWAP_COUNT_MASK (~SWAP_HAS_CACHE)
/*
 * The in-memory structure used to track swap areas.
 */
struct swap_info_struct {
	unsigned long	flags;		/* SWP_USED etc: see above */
	signed short	prio;		/* swap priority of this type */
	signed char	type;		/* strange name for an index */
	signed char	next;		/* next type on the swap list */
	struct file *swap_file;
	struct block_device *bdev;
	struct list_head extent_list;
	struct swap_extent *curr_swap_extent;
	unsigned short *swap_map;
	unsigned int lowest_bit;
	unsigned int highest_bit;
	unsigned int lowest_alloc;	/* while preparing discard cluster */
	unsigned int highest_alloc;	/* while preparing discard cluster */
	unsigned int cluster_next;
	unsigned int cluster_nr;
	unsigned int pages;
	unsigned int max;
	unsigned int inuse_pages;
	unsigned int old_block_size;
};

struct swap_list_t {
	int head;	/* head of priority-ordered swapfile list */
	int next;	/* swapfile to be used next */
};

/* Swap 50% full? Release swapcache more aggressively.. */
#define vm_swap_full() (nr_swap_pages*2 < total_swap_pages)

/* linux/mm/page_alloc.c */
extern unsigned long totalram_pages;
extern unsigned long totalreserve_pages;
extern unsigned int nr_free_buffer_pages(void);
extern unsigned int nr_free_pagecache_pages(void);

/* Definition of global_page_state not available yet */
#define nr_free_pages() global_page_state(NR_FREE_PAGES)


/* linux/mm/swap.c */
extern void __lru_cache_add(struct page *, enum lru_list lru);
extern void lru_cache_add_lru(struct page *, enum lru_list lru);
extern void activate_page(struct page *);
extern void mark_page_accessed(struct page *);
extern void lru_add_drain(void);
extern int lru_add_drain_all(void);
extern void rotate_reclaimable_page(struct page *page);
extern void swap_setup(void);

extern void add_page_to_unevictable_list(struct page *page);

/**
 * lru_cache_add: add a page to the page lists
 * @page: the page to add
 */
static inline void lru_cache_add_anon(struct page *page)
{
	__lru_cache_add(page, LRU_INACTIVE_ANON);
}

static inline void lru_cache_add_active_anon(struct page *page)
{
	__lru_cache_add(page, LRU_ACTIVE_ANON);
}

static inline void lru_cache_add_file(struct page *page)
{
	__lru_cache_add(page, LRU_INACTIVE_FILE);
}

static inline void lru_cache_add_active_file(struct page *page)
{
	__lru_cache_add(page, LRU_ACTIVE_FILE);
}

/* linux/mm/vmscan.c */
extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
					gfp_t gfp_mask, nodemask_t *mask);
extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem,
						  gfp_t gfp_mask, bool noswap,
						  unsigned int swappiness);
extern unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
						gfp_t gfp_mask, bool noswap,
						unsigned int swappiness,
						struct zone *zone,
						int nid);
extern int __isolate_lru_page(struct page *page, int mode, int file);
extern unsigned long shrink_all_memory(unsigned long nr_pages);
extern int vm_swappiness;
extern int remove_mapping(struct address_space *mapping, struct page *page);
extern long vm_total_pages;

#ifdef CONFIG_NUMA
extern int zone_reclaim_mode;
extern int sysctl_min_unmapped_ratio;
extern int sysctl_min_slab_ratio;
extern int zone_reclaim(struct zone *, gfp_t, unsigned int);
#else
#define zone_reclaim_mode 0
static inline int zone_reclaim(struct zone *z, gfp_t mask, unsigned int order)
{
	return 0;
}
#endif

extern int page_evictable(struct page *page, struct vm_area_struct *vma);
extern void scan_mapping_unevictable_pages(struct address_space *);

extern unsigned long scan_unevictable_pages;
extern int scan_unevictable_handler(struct ctl_table *, int,
					void __user *, size_t *, loff_t *);
extern int scan_unevictable_register_node(struct node *node);
extern void scan_unevictable_unregister_node(struct node *node);

extern int kswapd_run(int nid);
extern void kswapd_stop(int nid);

#ifdef CONFIG_MMU
/* linux/mm/shmem.c */
extern int shmem_unuse(swp_entry_t entry, struct page *page);
#endif /* CONFIG_MMU */

extern void swap_unplug_io_fn(struct backing_dev_info *, struct page *);

#ifdef CONFIG_SWAP
/* linux/mm/page_io.c */
extern int swap_readpage(struct page *);
extern int swap_writepage(struct page *page, struct writeback_control *wbc);
extern void end_swap_bio_read(struct bio *bio, int err);

/* linux/mm/swap_state.c */
extern struct address_space swapper_space;
#define total_swapcache_pages  swapper_space.nrpages
extern void show_swap_cache_info(void);
extern int add_to_swap(struct page *);
extern int add_to_swap_cache(struct page *, swp_entry_t, gfp_t);
extern void __delete_from_swap_cache(struct page *);
extern void delete_from_swap_cache(struct page *);
extern void free_page_and_swap_cache(struct page *);
extern void free_pages_and_swap_cache(struct page **, int);
extern struct page *lookup_swap_cache(swp_entry_t);
extern struct page *read_swap_cache_async(swp_entry_t, gfp_t,
			struct vm_area_struct *vma, unsigned long addr);
extern struct page *swapin_readahead(swp_entry_t, gfp_t,
			struct vm_area_struct *vma, unsigned long addr);

/* linux/mm/swapfile.c */
extern long nr_swap_pages;
extern long total_swap_pages;
extern void si_swapinfo(struct sysinfo *);
extern swp_entry_t get_swap_page(void);
extern swp_entry_t get_swap_page_of_type(int);
extern void swap_duplicate(swp_entry_t);
extern int swapcache_prepare(swp_entry_t);
extern int valid_swaphandles(swp_entry_t, unsigned long *);
extern void swap_free(swp_entry_t);
extern void swapcache_free(swp_entry_t, struct page *page);
extern int free_swap_and_cache(swp_entry_t);
extern int swap_type_of(dev_t, sector_t, struct block_device **);
extern unsigned int count_swap_pages(int, int);
extern sector_t map_swap_page(swp_entry_t, struct block_device **);
extern sector_t swapdev_block(int, pgoff_t);
extern int reuse_swap_page(struct page *);
extern int try_to_free_swap(struct page *);
struct backing_dev_info;

/* linux/mm/thrash.c */
extern struct mm_struct *swap_token_mm;
extern void grab_swap_token(struct mm_struct *);
extern void __put_swap_token(struct mm_struct *);

static inline int has_swap_token(struct mm_struct *mm)
{
	return (mm == swap_token_mm);
}

static inline void put_swap_token(struct mm_struct *mm)
{
	if (has_swap_token(mm))
		__put_swap_token(mm);
}

static inline void disable_swap_token(void)
{
	put_swap_token(swap_token_mm);
}

#ifdef CONFIG_CGROUP_MEM_RES_CTLR
extern void
mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout);
#else
static inline void
mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
{
}
#endif
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
extern void mem_cgroup_uncharge_swap(swp_entry_t ent);
#else
static inline void mem_cgroup_uncharge_swap(swp_entry_t ent)
{
}
#endif

#else /* CONFIG_SWAP */

#define nr_swap_pages				0L
#define total_swap_pages			0L
#define total_swapcache_pages			0UL

#define si_swapinfo(val) \
	do { (val)->freeswap = (val)->totalswap = 0; } while (0)
/* only sparc can not include linux/pagemap.h in this file
 * so leave page_cache_release and release_pages undeclared... */
#define free_page_and_swap_cache(page) \
	page_cache_release(page)
#define free_pages_and_swap_cache(pages, nr) \
	release_pages((pages), (nr), 0);

static inline void show_swap_cache_info(void)
{
}

#define free_swap_and_cache(swp)	is_migration_entry(swp)
#define swapcache_prepare(swp)		is_migration_entry(swp)

static inline void swap_duplicate(swp_entry_t swp)
{
}

static inline void swap_free(swp_entry_t swp)
{
}

static inline void swapcache_free(swp_entry_t swp, struct page *page)
{
}

static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask,
			struct vm_area_struct *vma, unsigned long addr)
{
	return NULL;
}

static inline int swap_writepage(struct page *p, struct writeback_control *wbc)
{
	return 0;
}

static inline struct page *lookup_swap_cache(swp_entry_t swp)
{
	return NULL;
}

static inline int add_to_swap(struct page *page)
{
	return 0;
}

static inline int add_to_swap_cache(struct page *page, swp_entry_t entry,
							gfp_t gfp_mask)
{
	return -1;
}

static inline void __delete_from_swap_cache(struct page *page)
{
}

static inline void delete_from_swap_cache(struct page *page)
{
}

#define reuse_swap_page(page)	(page_mapcount(page) == 1)

static inline int try_to_free_swap(struct page *page)
{
	return 0;
}

static inline swp_entry_t get_swap_page(void)
{
	swp_entry_t entry;
	entry.val = 0;
	return entry;
}

/* linux/mm/thrash.c */
static inline void put_swap_token(struct mm_struct *mm)
{
}

static inline void grab_swap_token(struct mm_struct *mm)
{
}

static inline int has_swap_token(struct mm_struct *mm)
{
	return 0;
}

static inline void disable_swap_token(void)
{
}

static inline void
mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent)
{
}

#endif /* CONFIG_SWAP */
#endif /* __KERNEL__*/
#endif /* _LINUX_SWAP_H */
Commit	Line	Data
1da177e4 LT	1	#ifndef _LINUX_SWAP_H
	2	#define _LINUX_SWAP_H
	3
1da177e4 LT	4	#include <linux/spinlock.h>
	5	#include <linux/linkage.h>
	6	#include <linux/mmzone.h>
	7	#include <linux/list.h>
66e1707b	8	#include <linux/memcontrol.h>
1da177e4	9	#include <linux/sched.h>
af936a16	10	#include <linux/node.h>
542d1c88	11
1da177e4 LT	12	#include <asm/atomic.h>
	13	#include <asm/page.h>
	14
8bc719d3 MS	15	struct notifier_block;
8bc719d3 MS	16
ab954160 AM	17	struct bio;
ab954160 AM	18
1da177e4 LT	19	#define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */
	20	#define SWAP_FLAG_PRIO_MASK 0x7fff
	21	#define SWAP_FLAG_PRIO_SHIFT 0
	22
	23	static inline int current_is_kswapd(void)
	24	{
	25	return current->flags & PF_KSWAPD;
	26	}
	27
	28	/*
	29	* MAX_SWAPFILES defines the maximum number of swaptypes: things which can
	30	* be swapped to. The swap type and the offset into that swap type are
	31	* encoded into pte's and into pgoff_t's in the swapcache. Using five bits
	32	* for the type means that the maximum number of swapcache pages is 27 bits
	33	* on 32-bit-pgoff_t architectures. And that assumes that the architecture packs
	34	* the type/offset into the pte as 5/27 as well.
	35	*/
	36	#define MAX_SWAPFILES_SHIFT 5
a7420aa5 AK	37
	38	/*
	39	* Use some of the swap files numbers for other purposes. This
	40	* is a convenient way to hook into the VM to trigger special
	41	* actions on faults.
	42	*/
	43
	44	/*
	45	* NUMA node memory migration support
	46	*/
	47	#ifdef CONFIG_MIGRATION
	48	#define SWP_MIGRATION_NUM 2
	49	#define SWP_MIGRATION_READ (MAX_SWAPFILES + SWP_HWPOISON_NUM)
	50	#define SWP_MIGRATION_WRITE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 1)
0697212a	51	#else
a7420aa5	52	#define SWP_MIGRATION_NUM 0
0697212a	53	#endif
1da177e4	54
a7420aa5 AK	55	/*
	56	* Handling of hardware poisoned pages with memory corruption.
	57	*/
	58	#ifdef CONFIG_MEMORY_FAILURE
	59	#define SWP_HWPOISON_NUM 1
	60	#define SWP_HWPOISON MAX_SWAPFILES
	61	#else
	62	#define SWP_HWPOISON_NUM 0
	63	#endif
	64
	65	#define MAX_SWAPFILES \
	66	((1 << MAX_SWAPFILES_SHIFT) - SWP_MIGRATION_NUM - SWP_HWPOISON_NUM)
	67
1da177e4 LT	68	/*
	69	* Magic header for a swap area. The first part of the union is
	70	* what the swap magic looks like for the old (limited to 128MB)
	71	* swap area format, the second part of the union adds - in the
	72	* old reserved area - some extra information. Note that the first
	73	* kilobyte is reserved for boot loader or disk label stuff...
	74	*
	75	* Having the magic at the end of the PAGE_SIZE makes detecting swap
	76	* areas somewhat tricky on machines that support multiple page sizes.
	77	* For 2.5 we'll probably want to move the magic to just beyond the
	78	* bootbits...
	79	*/
	80	union swap_header {
	81	struct {
	82	char reserved[PAGE_SIZE - 10];
	83	char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */
	84	} magic;
	85	struct {
e8f03d02 AD	86	char bootbits[1024]; /* Space for disklabel etc. */
	87	__u32 version;
	88	__u32 last_page;
	89	__u32 nr_badpages;
	90	unsigned char sws_uuid[16];
	91	unsigned char sws_volume[16];
	92	__u32 padding[117];
	93	__u32 badpages[1];
1da177e4 LT	94	} info;
	95	};
	96
	97	/* A swap entry has to fit into a "unsigned long", as
	98	* the entry is hidden in the "index" field of the
	99	* swapper address space.
	100	*/
	101	typedef struct {
	102	unsigned long val;
	103	} swp_entry_t;
	104
	105	/*
	106	* current->reclaim_state points to one of these when a task is running
	107	* memory reclaim
	108	*/
	109	struct reclaim_state {
	110	unsigned long reclaimed_slab;
	111	};
	112
	113	#ifdef __KERNEL__
	114
	115	struct address_space;
	116	struct sysinfo;
	117	struct writeback_control;
	118	struct zone;
	119
	120	/*
	121	* A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of
	122	* disk blocks. A list of swap extents maps the entire swapfile. (Where the
	123	* term `swapfile' refers to either a blockdevice or an IS_REG file. Apart
	124	* from setup, they're handled identically.
	125	*
	126	* We always assume that blocks are of size PAGE_SIZE.
	127	*/
	128	struct swap_extent {
	129	struct list_head list;
	130	pgoff_t start_page;
	131	pgoff_t nr_pages;
	132	sector_t start_block;
	133	};
	134
	135	/*
	136	* Max bad pages in the new format..
	137	*/
	138	#define __swapoffset(x) ((unsigned long)&((union swap_header *)0)->x)
	139	#define MAX_SWAP_BADPAGES \
	140	((__swapoffset(magic.magic) - __swapoffset(info.badpages)) / sizeof(int))
	141
	142	enum {
	143	SWP_USED = (1 << 0), /* is slot in swap_info[] used? */
	144	SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */
6a6ba831	145	SWP_DISCARDABLE = (1 << 2), /* blkdev supports discard */
7992fde7	146	SWP_DISCARDING = (1 << 3), /* now discarding a free cluster */
20137a49	147	SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */
52b7efdb HD	148	/* add others here before... */
52b7efdb HD	149	SWP_SCANNING = (1 << 8), /* refcount in scan_swap_map */
1da177e4 LT	150	};
	151
	152	#define SWAP_CLUSTER_MAX 32
	153
355cfa73 KH	154	#define SWAP_MAP_MAX 0x7ffe
	155	#define SWAP_MAP_BAD 0x7fff
	156	#define SWAP_HAS_CACHE 0x8000 /* There is a swap cache of entry. */
	157	#define SWAP_COUNT_MASK (~SWAP_HAS_CACHE)
1da177e4 LT	158	/*
1da177e4 LT	159	* The in-memory structure used to track swap areas.
1da177e4 LT	160	*/
1da177e4 LT	161	struct swap_info_struct {
efa90a98 HD	162	unsigned long flags; /* SWP_USED etc: see above */
	163	signed short prio; /* swap priority of this type */
	164	signed char type; /* strange name for an index */
	165	signed char next; /* next type on the swap list */
1da177e4 LT	166	struct file *swap_file;
	167	struct block_device *bdev;
	168	struct list_head extent_list;
1da177e4	169	struct swap_extent *curr_swap_extent;
ebebbbe9	170	unsigned short *swap_map;
1da177e4 LT	171	unsigned int lowest_bit;
1da177e4 LT	172	unsigned int highest_bit;
7992fde7 HD	173	unsigned int lowest_alloc; /* while preparing discard cluster */
7992fde7 HD	174	unsigned int highest_alloc; /* while preparing discard cluster */
1da177e4 LT	175	unsigned int cluster_next;
1da177e4 LT	176	unsigned int cluster_nr;
6eb396dc HD	177	unsigned int pages;
	178	unsigned int max;
	179	unsigned int inuse_pages;
ebebbbe9	180	unsigned int old_block_size;
1da177e4 LT	181	};
	182
	183	struct swap_list_t {
	184	int head; /* head of priority-ordered swapfile list */
	185	int next; /* swapfile to be used next */
	186	};
	187
	188	/* Swap 50% full? Release swapcache more aggressively.. */
	189	#define vm_swap_full() (nr_swap_pages*2 < total_swap_pages)
	190
1da177e4 LT	191	/* linux/mm/page_alloc.c */
1da177e4 LT	192	extern unsigned long totalram_pages;
cb45b0e9	193	extern unsigned long totalreserve_pages;
1da177e4 LT	194	extern unsigned int nr_free_buffer_pages(void);
	195	extern unsigned int nr_free_pagecache_pages(void);
	196
96177299 CL	197	/* Definition of global_page_state not available yet */
	198	#define nr_free_pages() global_page_state(NR_FREE_PAGES)
	199
	200
1da177e4	201	/* linux/mm/swap.c */
f04e9ebb KM	202	extern void __lru_cache_add(struct page *, enum lru_list lru);
f04e9ebb KM	203	extern void lru_cache_add_lru(struct page *, enum lru_list lru);
b3c97528 HH	204	extern void activate_page(struct page *);
b3c97528 HH	205	extern void mark_page_accessed(struct page *);
1da177e4	206	extern void lru_add_drain(void);
053837fc	207	extern int lru_add_drain_all(void);
ac6aadb2	208	extern void rotate_reclaimable_page(struct page *page);
1da177e4 LT	209	extern void swap_setup(void);
1da177e4 LT	210
894bc310 LS	211	extern void add_page_to_unevictable_list(struct page *page);
894bc310 LS	212
f04e9ebb KM	213	/**
	214	* lru_cache_add: add a page to the page lists
	215	* @page: the page to add
	216	*/
4f98a2fe	217	static inline void lru_cache_add_anon(struct page *page)
f04e9ebb	218	{
4f98a2fe	219	__lru_cache_add(page, LRU_INACTIVE_ANON);
f04e9ebb KM	220	}
f04e9ebb KM	221
4f98a2fe	222	static inline void lru_cache_add_active_anon(struct page *page)
f04e9ebb	223	{
4f98a2fe RR	224	__lru_cache_add(page, LRU_ACTIVE_ANON);
	225	}
	226
	227	static inline void lru_cache_add_file(struct page *page)
	228	{
	229	__lru_cache_add(page, LRU_INACTIVE_FILE);
	230	}
	231
	232	static inline void lru_cache_add_active_file(struct page *page)
	233	{
	234	__lru_cache_add(page, LRU_ACTIVE_FILE);
f04e9ebb KM	235	}
f04e9ebb KM	236
1da177e4	237	/* linux/mm/vmscan.c */
dac1d27b	238	extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
327c0e96	239	gfp_t gfp_mask, nodemask_t *mask);
e1a1cd59	240	extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem,
a7885eb8 KM	241	gfp_t gfp_mask, bool noswap,
a7885eb8 KM	242	unsigned int swappiness);
4e416953 BS	243	extern unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
	244	gfp_t gfp_mask, bool noswap,
	245	unsigned int swappiness,
	246	struct zone *zone,
	247	int nid);
4f98a2fe	248	extern int __isolate_lru_page(struct page *page, int mode, int file);
69e05944	249	extern unsigned long shrink_all_memory(unsigned long nr_pages);
1da177e4	250	extern int vm_swappiness;
b20a3503	251	extern int remove_mapping(struct address_space mapping, struct page page);
bd1e22b8	252	extern long vm_total_pages;
b20a3503	253
9eeff239 CL	254	#ifdef CONFIG_NUMA
9eeff239 CL	255	extern int zone_reclaim_mode;
9614634f	256	extern int sysctl_min_unmapped_ratio;
0ff38490	257	extern int sysctl_min_slab_ratio;
9eeff239 CL	258	extern int zone_reclaim(struct zone *, gfp_t, unsigned int);
	259	#else
	260	#define zone_reclaim_mode 0
	261	static inline int zone_reclaim(struct zone *z, gfp_t mask, unsigned int order)
	262	{
	263	return 0;
	264	}
	265	#endif
	266
894bc310	267	extern int page_evictable(struct page page, struct vm_area_struct vma);
89e004ea	268	extern void scan_mapping_unevictable_pages(struct address_space *);
af936a16 LS	269
af936a16 LS	270	extern unsigned long scan_unevictable_pages;
8d65af78	271	extern int scan_unevictable_handler(struct ctl_table *, int,
af936a16 LS	272	void __user , size_t , loff_t *);
	273	extern int scan_unevictable_register_node(struct node *node);
	274	extern void scan_unevictable_unregister_node(struct node *node);
894bc310	275
3218ae14	276	extern int kswapd_run(int nid);
8fe23e05	277	extern void kswapd_stop(int nid);
3218ae14	278
1da177e4 LT	279	#ifdef CONFIG_MMU
	280	/* linux/mm/shmem.c */
	281	extern int shmem_unuse(swp_entry_t entry, struct page *page);
	282	#endif /* CONFIG_MMU */
	283
	284	extern void swap_unplug_io_fn(struct backing_dev_info , struct page );
	285
	286	#ifdef CONFIG_SWAP
	287	/* linux/mm/page_io.c */
aca8bf32	288	extern int swap_readpage(struct page *);
1da177e4	289	extern int swap_writepage(struct page page, struct writeback_control wbc);
6712ecf8	290	extern void end_swap_bio_read(struct bio *bio, int err);
1da177e4 LT	291
	292	/* linux/mm/swap_state.c */
	293	extern struct address_space swapper_space;
	294	#define total_swapcache_pages swapper_space.nrpages
	295	extern void show_swap_cache_info(void);
ac47b003	296	extern int add_to_swap(struct page *);
73b1262f	297	extern int add_to_swap_cache(struct page *, swp_entry_t, gfp_t);
1da177e4 LT	298	extern void __delete_from_swap_cache(struct page *);
1da177e4 LT	299	extern void delete_from_swap_cache(struct page *);
1da177e4 LT	300	extern void free_page_and_swap_cache(struct page *);
1da177e4 LT	301	extern void free_pages_and_swap_cache(struct page **, int);
46017e95	302	extern struct page *lookup_swap_cache(swp_entry_t);
02098fea	303	extern struct page *read_swap_cache_async(swp_entry_t, gfp_t,
46017e95	304	struct vm_area_struct *vma, unsigned long addr);
02098fea	305	extern struct page *swapin_readahead(swp_entry_t, gfp_t,
46017e95 HD	306	struct vm_area_struct *vma, unsigned long addr);
46017e95 HD	307
1da177e4	308	/* linux/mm/swapfile.c */
b962716b	309	extern long nr_swap_pages;
1da177e4	310	extern long total_swap_pages;
1da177e4 LT	311	extern void si_swapinfo(struct sysinfo *);
1da177e4 LT	312	extern swp_entry_t get_swap_page(void);
f577eb30	313	extern swp_entry_t get_swap_page_of_type(int);
355cfa73	314	extern void swap_duplicate(swp_entry_t);
cb4b86ba	315	extern int swapcache_prepare(swp_entry_t);
1da177e4 LT	316	extern int valid_swaphandles(swp_entry_t, unsigned long *);
1da177e4 LT	317	extern void swap_free(swp_entry_t);
cb4b86ba	318	extern void swapcache_free(swp_entry_t, struct page *page);
2509ef26	319	extern int free_swap_and_cache(swp_entry_t);
7bf23687	320	extern int swap_type_of(dev_t, sector_t, struct block_device **);
f577eb30	321	extern unsigned int count_swap_pages(int, int);
f29ad6a9	322	extern sector_t map_swap_page(swp_entry_t, struct block_device **);
3aef83e0	323	extern sector_t swapdev_block(int, pgoff_t);
7b1fe597	324	extern int reuse_swap_page(struct page *);
a2c43eed	325	extern int try_to_free_swap(struct page *);
1da177e4 LT	326	struct backing_dev_info;
1da177e4 LT	327
1da177e4	328	/* linux/mm/thrash.c */
a5c9b696 HD	329	extern struct mm_struct *swap_token_mm;
a5c9b696 HD	330	extern void grab_swap_token(struct mm_struct *);
1da177e4 LT	331	extern void __put_swap_token(struct mm_struct *);
	332
	333	static inline int has_swap_token(struct mm_struct *mm)
	334	{
	335	return (mm == swap_token_mm);
	336	}
	337
	338	static inline void put_swap_token(struct mm_struct *mm)
	339	{
	340	if (has_swap_token(mm))
	341	__put_swap_token(mm);
	342	}
	343
f7b7fd8f RR	344	static inline void disable_swap_token(void)
	345	{
	346	put_swap_token(swap_token_mm);
	347	}
	348
d13d1443	349	#ifdef CONFIG_CGROUP_MEM_RES_CTLR
8a9478ca KH	350	extern void
8a9478ca KH	351	mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout);
d13d1443	352	#else
8c7c6e34	353	static inline void
8a9478ca	354	mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
8c7c6e34 KH	355	{
	356	}
	357	#endif
	358	#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
	359	extern void mem_cgroup_uncharge_swap(swp_entry_t ent);
	360	#else
	361	static inline void mem_cgroup_uncharge_swap(swp_entry_t ent)
d13d1443 KH	362	{
	363	}
	364	#endif
	365
1da177e4 LT	366	#else /* CONFIG_SWAP */
1da177e4 LT	367
b962716b HD	368	#define nr_swap_pages 0L
b962716b HD	369	#define total_swap_pages 0L
1da177e4 LT	370	#define total_swapcache_pages 0UL
	371
	372	#define si_swapinfo(val) \
	373	do { (val)->freeswap = (val)->totalswap = 0; } while (0)
9ae5b3c7 OH	374	/* only sparc can not include linux/pagemap.h in this file
9ae5b3c7 OH	375	* so leave page_cache_release and release_pages undeclared... */
1da177e4 LT	376	#define free_page_and_swap_cache(page) \
	377	page_cache_release(page)
	378	#define free_pages_and_swap_cache(pages, nr) \
	379	release_pages((pages), (nr), 0);
	380
bd96b9eb CK	381	static inline void show_swap_cache_info(void)
	382	{
	383	}
	384
2509ef26	385	#define free_swap_and_cache(swp) is_migration_entry(swp)
cb4b86ba	386	#define swapcache_prepare(swp) is_migration_entry(swp)
bd96b9eb	387
355cfa73 KH	388	static inline void swap_duplicate(swp_entry_t swp)
	389	{
	390	}
	391
bd96b9eb CK	392	static inline void swap_free(swp_entry_t swp)
	393	{
	394	}
	395
cb4b86ba KH	396	static inline void swapcache_free(swp_entry_t swp, struct page *page)
	397	{
	398	}
	399
02098fea	400	static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask,
bd96b9eb CK	401	struct vm_area_struct *vma, unsigned long addr)
	402	{
	403	return NULL;
	404	}
	405
9fab5619 HD	406	static inline int swap_writepage(struct page p, struct writeback_control wbc)
	407	{
	408	return 0;
	409	}
	410
bd96b9eb CK	411	static inline struct page *lookup_swap_cache(swp_entry_t swp)
	412	{
	413	return NULL;
	414	}
	415
60371d97 HD	416	static inline int add_to_swap(struct page *page)
	417	{
	418	return 0;
	419	}
	420
73b1262f HD	421	static inline int add_to_swap_cache(struct page *page, swp_entry_t entry,
73b1262f HD	422	gfp_t gfp_mask)
bd96b9eb	423	{
73b1262f	424	return -1;
bd96b9eb CK	425	}
	426
	427	static inline void __delete_from_swap_cache(struct page *page)
	428	{
	429	}
	430
	431	static inline void delete_from_swap_cache(struct page *page)
	432	{
	433	}
	434
7b1fe597	435	#define reuse_swap_page(page) (page_mapcount(page) == 1)
1da177e4	436
a2c43eed	437	static inline int try_to_free_swap(struct page *page)
68a22394 RR	438	{
	439	return 0;
	440	}
	441
1da177e4 LT	442	static inline swp_entry_t get_swap_page(void)
	443	{
	444	swp_entry_t entry;
	445	entry.val = 0;
	446	return entry;
	447	}
	448
	449	/* linux/mm/thrash.c */
a5abeeac JW	450	static inline void put_swap_token(struct mm_struct *mm)
	451	{
	452	}
	453
	454	static inline void grab_swap_token(struct mm_struct *mm)
	455	{
	456	}
	457
	458	static inline int has_swap_token(struct mm_struct *mm)
	459	{
	460	return 0;
	461	}
	462
	463	static inline void disable_swap_token(void)
	464	{
	465	}
1da177e4	466
e767e056 DN	467	static inline void
	468	mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent)
	469	{
	470	}
	471
1da177e4 LT	472	#endif /* CONFIG_SWAP */
	473	#endif /* __KERNEL__*/
	474	#endif /* _LINUX_SWAP_H */