1.\" $OpenBSD: mlockall.2,v 1.5 2008/06/26 05:42:05 ray Exp $ 2.\" $NetBSD: mlockall.2,v 1.6 2000/06/26 17:00:02 kleink Exp $ 3.\" 4.\" Copyright (c) 1999 The NetBSD Foundation, Inc. 5.\" All rights reserved. 6.\" 7.\" This code is derived from software contributed to The NetBSD Foundation 8.\" by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 9.\" NASA Ames Research Center. 10.\" 11.\" Redistribution and use in source and binary forms, with or without 12.\" modification, are permitted provided that the following conditions 13.\" are met: 14.\" 1. Redistributions of source code must retain the above copyright 15.\" notice, this list of conditions and the following disclaimer. 16.\" 2. Redistributions in binary form must reproduce the above copyright 17.\" notice, this list of conditions and the following disclaimer in the 18.\" documentation and/or other materials provided with the distribution. 19.\" 3. All advertising materials mentioning features or use of this software 20.\" must display the following acknowledgement: 21.\" This product includes software developed by the NetBSD 22.\" Foundation, Inc. and its contributors. 23.\" 4. Neither the name of The NetBSD Foundation nor the names of its 24.\" contributors may be used to endorse or promote products derived 25.\" from this software without specific prior written permission. 26.\" 27.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37.\" POSSIBILITY OF SUCH DAMAGE. 38.\" 39.Dd November 29, 2010 40.Dt MLOCKALL 2 41.Os 42.Sh NAME 43.Nm mlockall , 44.Nm munlockall 45.Nd lock (unlock) the address space of a process 46.Sh LIBRARY 47.Lb libc 48.Sh SYNOPSIS 49.In sys/types.h 50.In sys/mman.h 51.Ft int 52.Fn mlockall "int flags" 53.Ft int 54.Fn munlockall "void" 55.Sh DESCRIPTION 56The 57.Fn mlockall 58system call locks into memory the physical pages associated with the 59address space of a process until the address space is unlocked, the 60process exits, or execs another program image. 61.Pp 62The following flags affect the behavior of 63.Fn mlockall : 64.Bl -tag -width ".Dv MCL_CURRENT" 65.It Dv MCL_CURRENT 66Lock all pages currently mapped into the process's address space. 67.It Dv MCL_FUTURE 68Lock all pages mapped into the process's address space in the future, 69at the time the mapping is established. 70Note that this may cause future mappings to fail if those mappings 71cause resource limits to be exceeded. 72.El 73.Pp 74Since physical memory is a potentially scarce resource, processes are 75limited in how much they can lock down. 76A single process can lock the minimum of a system-wide 77.Dq wired pages 78limit and the per-process 79.Dv RLIMIT_MEMLOCK 80resource limit. 81.Pp 82The 83.Fn munlockall 84call unlocks any locked memory regions in the process address space. 85Any regions mapped after an 86.Fn munlockall 87call will not be locked. 88.Sh RETURN VALUES 89A return value of 0 indicates that the call 90succeeded and all pages in the range have either been locked or unlocked. 91A return value of \-1 indicates an error occurred and the locked 92status of all pages in the range remains unchanged. 93In this case, the global location 94.Va errno 95is set to indicate the error. 96.Sh ERRORS 97.Fn mlockall 98will fail if: 99.Bl -tag -width Er 100.It Bq Er EINVAL 101The 102.Fa flags 103argument is zero, or includes unimplemented flags. 104.It Bq Er ENOMEM 105Locking the indicated range would exceed either the system or per-process 106limit for locked memory. 107.It Bq Er EPERM 108The calling process does not have the appropriate privilege to perform 109the requested operation. 110.El 111.Sh SEE ALSO 112.Xr mincore 2 , 113.Xr mlock 2 , 114.Xr setrlimit 2 115.Sh STANDARDS 116The 117.Fn mlockall 118and 119.Fn munlockall 120functions are believed to conform to 121.St -p1003.1-2001 . 122.Sh HISTORY 123The 124.Fn mlockall 125and 126.Fn munlockall 127functions first appeared in 128.Dx 2.9 . 129.Sh BUGS 130The 131.Dv MCL_CURRENT 132flag does not function in 133.Dx 134currently. 135