8 * SHMMAX, SHMMNI and SHMALL are upper limits are defaults which can
9 * be increased by sysctl
12 #define SHMMAX 0x2000000 /* max shared seg size (bytes) */
13 #define SHMMIN 1 /* min shared seg size (bytes) */
14 #define SHMMNI 4096 /* max num of segs system wide */
15 #define SHMALL (SHMMAX/PAGE_SIZE*(SHMMNI/16)) /* max shm system wide (pages) */
16 #define SHMSEG SHMMNI /* max shared segs per process */
18 #include <asm/shmparam.h>
20 /* Obsolete, used only for backwards compatibility and libc5 compiles */
22 struct ipc_perm shm_perm
; /* operation perms */
23 int shm_segsz
; /* size of segment (bytes) */
24 __kernel_time_t shm_atime
; /* last attach time */
25 __kernel_time_t shm_dtime
; /* last detach time */
26 __kernel_time_t shm_ctime
; /* last change time */
27 __kernel_ipc_pid_t shm_cpid
; /* pid of creator */
28 __kernel_ipc_pid_t shm_lpid
; /* pid of last operator */
29 unsigned short shm_nattch
; /* no. of current attaches */
30 unsigned short shm_unused
; /* compatibility */
31 void *shm_unused2
; /* ditto - used by DIPC */
32 void *shm_unused3
; /* unused */
35 /* Include the definition of shmid64_ds and shminfo64 */
36 #include <asm/shmbuf.h>
38 /* permission flag for shmget */
39 #define SHM_R 0400 /* or S_IRUGO from <linux/stat.h> */
40 #define SHM_W 0200 /* or S_IWUGO from <linux/stat.h> */
43 #define SHM_RDONLY 010000 /* read-only access */
44 #define SHM_RND 020000 /* round attach address to SHMLBA boundary */
45 #define SHM_REMAP 040000 /* take-over region on attach */
47 /* super user shmctl commands */
51 /* ipcs ctl commands */
55 /* Obsolete, used only for backwards compatibility */
66 unsigned long shm_tot
; /* total allocated shm */
67 unsigned long shm_rss
; /* total resident shm */
68 unsigned long shm_swp
; /* total swapped shm */
69 unsigned long swap_attempts
;
70 unsigned long swap_successes
;
75 /* shm_mode upper byte flags */
76 #define SHM_DEST 01000 /* segment will be destroyed on last detach */
77 #define SHM_LOCKED 02000 /* segment will not be swapped */
79 asmlinkage
long sys_shmget (key_t key
, size_t size
, int flag
);
80 asmlinkage
long sys_shmat (int shmid
, char *shmaddr
, int shmflg
, unsigned long *addr
);
81 asmlinkage
long sys_shmdt (char *shmaddr
);
82 asmlinkage
long sys_shmctl (int shmid
, int cmd
, struct shmid_ds
*buf
);
83 extern void shm_unuse(swp_entry_t entry
, struct page
*page
);
85 #endif /* __KERNEL__ */
87 #endif /* _LINUX_SHM_H_ */