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.\" Copyright (C) Markus Kuhn, 1996
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.\" 1995-11-26  Markus Kuhn <mskuhn@cip.informatik.uni-erlangen.de>
.\"      First version written
.\" Modified, 27 May 2004, Michael Kerrisk <mtk-manpages@gmx.net>
.\"     Added notes on capability requirements
.\"
.TH MUNLOCKALL 2 2004-05-27 "Linux 2.6.6" "Linux Programmer's Manual"
.SH NAME
munlockall \- reenable paging for calling process
.SH SYNOPSIS
.nf
.B #include <sys/mman.h>
.sp
\fBint munlockall(void);
.fi
.SH DESCRIPTION
.B munlockall
reenables paging for all pages mapped into the address space of the
calling process.

Memory locks do not stack, i.e., pages which have been locked several times
by calls to
.B mlock
or
.B mlockall
will be unlocked by a single call to
.BR munlockall .
Pages which are mapped to several locations or by several processes stay
locked into RAM as long as they are locked at least at one location or by
at least one process.

On POSIX systems on which
.B mlockall
and
.B munlockall
are available,
.B _POSIX_MEMLOCK
is defined in
.I <unistd.h> .
.SH "RETURN VALUE"
On success,
.B munlockall
returns zero.  On error, \-1 is returned and
.I errno
is set appropriately.
.SH ERRORS
.TP
.B EPERM
The calling process has insufficient privilege to call 
.BR munlockall .
Under Linux the
.B CAP_IPC_LOCK
capability is required.
.\" Weirdness this way comes: CAP_IPC_LOCK is required for munlockall()
.\" and shmctl(SHM_UNLOCK), but is *not* required for munlock 
.\" (as at kernel 2.6.6)
.SH "CONFORMING TO"
POSIX.1b, SVr4
.SH "SEE ALSO"
.BR mlock (2),
.BR mlockall (2),
.BR munlock (2),
.BR capabilities (7)