NAME

mlockall, munlockall - lock or unlock address space

SYNOPSIS

#include <sys/mman.h>

int mlockall(int flags);
int munlockall(void);

DESCRIPTION

The function mlockall causes all pages mapped by an address space to be locked in memory. The effect of mlockall(flags) is equivalent to:

     memcntl(0, 0, MC_LOCKAS, flags, 0, 0)
The value of flags determines whether the pages to be locked
are  those currently mapped by the address space, those that
will be mapped in the future, or both:
           MCL_CURRENT   Lock current mappings
           MCL_FUTURE    Lock future mappings
The function munlockall  removes  address  space  locks  and
locks  on mappings in the address space.  The effect of mun-
lockall is equivalent to:

     memcntl(0, 0, MC_UNLOCKAS, 0, 0, 0)
Locks established with mlockall are not inherited by a child
process after a fork and are not nested.

SEE ALSO

fork(2), memcntl(2), mlock(3C), mmap(2), plock(2),
sysconf(3C).

DIAGNOSTICS

Upon successful completion, the functions mlockall and munlockall return 0; otherwise, they return -1 and set errno to indicate the error.

NOTES

Use of mlockall and munlockall requires that the user have appropriate privileges.