summaryrefslogtreecommitdiffstats
path: root/include/linux/swap.h
blob: d0873952ab9fe93d1bdc327e07337fb09ec49753 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
#ifndef _LINUX_SWAP_H
#define _LINUX_SWAP_H

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

#define MAX_SWAPFILES 8

#ifdef __KERNEL__

#include <asm/atomic.h>

#define SWP_USED	1
#define SWP_WRITEOK	3

#define SWAP_CLUSTER_MAX 32

struct swap_info_struct {
	unsigned int flags;
	kdev_t swap_device;
	struct dentry * swap_file;
	unsigned char * swap_map;
	unsigned char * swap_lockmap;
	unsigned int lowest_bit;
	unsigned int highest_bit;
	unsigned int cluster_next;
	unsigned int cluster_nr;
	int prio;			/* swap priority */
	int pages;
	unsigned long max;
	int next;			/* next entry on swap list */
};

extern int nr_swap_pages;
extern int nr_free_pages;
extern atomic_t nr_async_pages;
extern int min_free_pages;
extern int free_pages_low;
extern int free_pages_high;

/* Incomplete types for prototype declarations: */
struct task_struct;
struct vm_area_struct;
struct sysinfo;

/* linux/ipc/shm.c */
extern int shm_swap (int, int);

/* linux/mm/vmscan.c */
extern int try_to_free_page(int, int, int);

/* linux/mm/page_io.c */
extern void rw_swap_page(int, unsigned long, char *, int);
#define read_swap_page(nr,buf) \
	rw_swap_page(READ,(nr),(buf),1)
#define write_swap_page(nr,buf) \
	rw_swap_page(WRITE,(nr),(buf),1)
extern void swap_after_unlock_page (unsigned long entry);

/* linux/mm/page_alloc.c */
extern void swap_in(struct task_struct *, struct vm_area_struct *,
		    pte_t *, unsigned long, int);


/* linux/mm/swap_state.c */
extern void show_swap_cache_info(void);
extern int add_to_swap_cache(struct page *, unsigned long);
extern void swap_duplicate(unsigned long);

/* linux/mm/swapfile.c */
extern unsigned int nr_swapfiles;
extern struct swap_info_struct swap_info[];
void si_swapinfo(struct sysinfo *);
unsigned long get_swap_page(void);
extern void FASTCALL(swap_free(unsigned long));

/*
 * vm_ops not present page codes for shared memory.
 *
 * Will go away eventually..
 */
#define SHM_SWP_TYPE 0x40

/*
 * swap cache stuff (in linux/mm/swap_state.c)
 */

#define SWAP_CACHE_INFO

#ifdef SWAP_CACHE_INFO
extern unsigned long swap_cache_add_total;
extern unsigned long swap_cache_add_success;
extern unsigned long swap_cache_del_total;
extern unsigned long swap_cache_del_success;
extern unsigned long swap_cache_find_total;
extern unsigned long swap_cache_find_success;
#endif

extern inline unsigned long in_swap_cache(struct page *page)
{
	if (PageSwapCache(page))
		return page->pg_swap_entry;
	return 0;
}

extern inline long find_in_swap_cache(struct page *page)
{
#ifdef SWAP_CACHE_INFO
	swap_cache_find_total++;
#endif
	if (PageTestandClearSwapCache(page))  {
#ifdef SWAP_CACHE_INFO
		swap_cache_find_success++;
#endif	
		return page->pg_swap_entry;
	}
	return 0;
}

extern inline int delete_from_swap_cache(struct page *page)
{
#ifdef SWAP_CACHE_INFO
	swap_cache_del_total++;
#endif	
	if (PageTestandClearSwapCache(page))  {
#ifdef SWAP_CACHE_INFO
		swap_cache_del_success++;
#endif
		swap_free(page->pg_swap_entry);
		return 1;
	}
	return 0;
}


#endif /* __KERNEL__*/

#endif /* _LINUX_SWAP_H */