mlockall(2)

DESCRIPTION

The mlockall() system call allows the calling process to lock its entire virtual address space into memory, making it immune to all routine swapping.

flags may be one or both of the following:

Note that MCL_FUTURE does not imply MCL_CURRENT.

munlockall() or munlock() can be used to unlock all or a portion of the address space locked with mlockall(). A single call to munlockall() removes all locks from the process virtual address space. An munlock() call results in only the specified pages being unlocked.

Regardless of how many times a process locks a page, a single munlock() or munlockall() will unlock it.

When memory is shared by multiple processes and mlocks are applied to the same physical page by multiple processes, a page remains locked until the last lock is removed from that page.

Locks and MCL_FUTURE applied with mlockall() are not inherited by a child process.

The effective user ID of the calling process must be a superuser or the user must be a member of a group that has the MLOCK privilege (see getprivgrp(2) and setprivgrp(1M)).

Although plock() and the mlock() family of functions may be used together in an application, each may affect the other in unexpected ways. This practice is not recommended.

RETURN VALUE

mlockall() returns the following values:

ERRORS

If mlockall() fails, errno is set to one of the following values:

EXAMPLES

The following call to mlockall() locks the entire process virtual address space in memory and ensures that any future additions to the address space will also be locked in memory:

SEE ALSO

setprivgrp(1M), getprivgrp(2), mlock(2), munlock(2), munlockall(2), plock(2).

STANDARDS CONFORMANCE

mlockall(): POSIX Realtime Extensions, IEEE Std 1003.1b