https://github.com/torvalds/linux
Tip revision: 8e4a718ff38d8539938ec3421935904c27e00c39 authored by Linus Torvalds on 04 July 2009, 17:58:48 UTC
Linux 2.6.31-rc2
Linux 2.6.31-rc2
Tip revision: 8e4a718
shm.h
#ifndef _LINUX_SHM_H_
#define _LINUX_SHM_H_
#include <linux/ipc.h>
#include <linux/errno.h>
#ifdef __KERNEL__
#include <asm/page.h>
#else
#include <unistd.h>
#endif
/*
* SHMMAX, SHMMNI and SHMALL are upper limits are defaults which can
* be increased by sysctl
*/
#define SHMMAX 0x2000000 /* max shared seg size (bytes) */
#define SHMMIN 1 /* min shared seg size (bytes) */
#define SHMMNI 4096 /* max num of segs system wide */
#ifdef __KERNEL__
#define SHMALL (SHMMAX/PAGE_SIZE*(SHMMNI/16)) /* max shm system wide (pages) */
#else
#define SHMALL (SHMMAX/getpagesize()*(SHMMNI/16))
#endif
#define SHMSEG SHMMNI /* max shared segs per process */
#ifdef __KERNEL__
#include <asm/shmparam.h>
#endif
/* Obsolete, used only for backwards compatibility and libc5 compiles */
struct shmid_ds {
struct ipc_perm shm_perm; /* operation perms */
int shm_segsz; /* size of segment (bytes) */
__kernel_time_t shm_atime; /* last attach time */
__kernel_time_t shm_dtime; /* last detach time */
__kernel_time_t shm_ctime; /* last change time */
__kernel_ipc_pid_t shm_cpid; /* pid of creator */
__kernel_ipc_pid_t shm_lpid; /* pid of last operator */
unsigned short shm_nattch; /* no. of current attaches */
unsigned short shm_unused; /* compatibility */
void *shm_unused2; /* ditto - used by DIPC */
void *shm_unused3; /* unused */
};
/* Include the definition of shmid64_ds and shminfo64 */
#include <asm/shmbuf.h>
/* permission flag for shmget */
#define SHM_R 0400 /* or S_IRUGO from <linux/stat.h> */
#define SHM_W 0200 /* or S_IWUGO from <linux/stat.h> */
/* mode for attach */
#define SHM_RDONLY 010000 /* read-only access */
#define SHM_RND 020000 /* round attach address to SHMLBA boundary */
#define SHM_REMAP 040000 /* take-over region on attach */
#define SHM_EXEC 0100000 /* execution access */
/* super user shmctl commands */
#define SHM_LOCK 11
#define SHM_UNLOCK 12
/* ipcs ctl commands */
#define SHM_STAT 13
#define SHM_INFO 14
/* Obsolete, used only for backwards compatibility */
struct shminfo {
int shmmax;
int shmmin;
int shmmni;
int shmseg;
int shmall;
};
struct shm_info {
int used_ids;
unsigned long shm_tot; /* total allocated shm */
unsigned long shm_rss; /* total resident shm */
unsigned long shm_swp; /* total swapped shm */
unsigned long swap_attempts;
unsigned long swap_successes;
};
#ifdef __KERNEL__
struct shmid_kernel /* private to the kernel */
{
struct kern_ipc_perm shm_perm;
struct file * shm_file;
unsigned long shm_nattch;
unsigned long shm_segsz;
time_t shm_atim;
time_t shm_dtim;
time_t shm_ctim;
pid_t shm_cprid;
pid_t shm_lprid;
struct user_struct *mlock_user;
};
/* shm_mode upper byte flags */
#define SHM_DEST 01000 /* segment will be destroyed on last detach */
#define SHM_LOCKED 02000 /* segment will not be swapped */
#define SHM_HUGETLB 04000 /* segment will use huge TLB pages */
#define SHM_NORESERVE 010000 /* don't check for reservations */
#ifdef CONFIG_SYSVIPC
long do_shmat(int shmid, char __user *shmaddr, int shmflg, unsigned long *addr);
extern int is_file_shm_hugepages(struct file *file);
#else
static inline long do_shmat(int shmid, char __user *shmaddr,
int shmflg, unsigned long *addr)
{
return -ENOSYS;
}
static inline int is_file_shm_hugepages(struct file *file)
{
return 0;
}
#endif
#endif /* __KERNEL__ */
#endif /* _LINUX_SHM_H_ */