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| author | Michael Kerrisk <mtk.manpages@gmail.com> | 2019-08-26 22:28:45 +0200 |
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| committer | Michael Kerrisk <mtk.manpages@gmail.com> | 2019-08-26 23:14:49 +0200 |
| commit | 1d36b4e17ba99634af192913d55153780943ec0c (patch) | |
| tree | b5e3fc74baa41dae552f73e7be62f3c63615eafb | |
| parent | 872e676db5097413d695cb841b195de74b139baf (diff) | |
| download | man-pages-1d36b4e17ba99634af192913d55153780943ec0c.tar.gz | |
ipc_namespaces.7: New page with content migrated from namespaces(7)
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
| -rw-r--r-- | man7/ipc_namespaces.7 | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/man7/ipc_namespaces.7 b/man7/ipc_namespaces.7 new file mode 100644 index 0000000000..0adf2f7656 --- /dev/null +++ b/man7/ipc_namespaces.7 @@ -0,0 +1,86 @@ +.\" Copyright (c) 2019 by Michael Kerrisk <mtk.manpages@gmail.com> +.\" +.\" %%%LICENSE_START(VERBATIM) +.\" Permission is granted to make and distribute verbatim copies of this +.\" manual provided the copyright notice and this permission notice are +.\" preserved on all copies. +.\" +.\" Permission is granted to copy and distribute modified versions of this +.\" manual under the conditions for verbatim copying, provided that the +.\" entire resulting derived work is distributed under the terms of a +.\" permission notice identical to this one. +.\" +.\" Since the Linux kernel and libraries are constantly changing, this +.\" manual page may be incorrect or out-of-date. The author(s) assume no +.\" responsibility for errors or omissions, or for damages resulting from +.\" the use of the information contained herein. The author(s) may not +.\" have taken the same level of care in the production of this manual, +.\" which is licensed free of charge, as they might when working +.\" professionally. +.\" +.\" Formatted or processed versions of this manual, if unaccompanied by +.\" the source, must acknowledge the copyright and authors of this work. +.\" %%%LICENSE_END +.\" +.\" +.TH IPC_NAMESPACES 7 2019-08-02 "Linux" "Linux Programmer's Manual" +.SH NAME +namespaces \- overview of Linux IPC namespaces +.SH DESCRIPTION +IPC namespaces isolate certain IPC resources, +namely, System V IPC objects (see +.BR sysvipc (7)) +and (since Linux 2.6.30) +.\" commit 7eafd7c74c3f2e67c27621b987b28397110d643f +.\" https://lwn.net/Articles/312232/ +POSIX message queues (see +.BR mq_overview (7)). +The common characteristic of these IPC mechanisms is that IPC +objects are identified by mechanisms other than filesystem +pathnames. +.PP +Each IPC namespace has its own set of System V IPC identifiers and +its own POSIX message queue filesystem. +Objects created in an IPC namespace are visible to all other processes +that are members of that namespace, +but are not visible to processes in other IPC namespaces. +.PP +The following +.I /proc +interfaces are distinct in each IPC namespace: +.IP * 3 +The POSIX message queue interfaces in +.IR /proc/sys/fs/mqueue . +.IP * +The System V IPC interfaces in +.IR /proc/sys/kernel , +namely: +.IR msgmax , +.IR msgmnb , +.IR msgmni , +.IR sem , +.IR shmall , +.IR shmmax , +.IR shmmni , +and +.IR shm_rmid_forced . +.IP * +The System V IPC interfaces in +.IR /proc/sysvipc . +.PP +When an IPC namespace is destroyed +(i.e., when the last process that is a member of the namespace terminates), +all IPC objects in the namespace are automatically destroyed. +.PP +Use of IPC namespaces requires a kernel that is configured with the +.B CONFIG_IPC_NS +option. +.SH SEE ALSO +.BR nsenter (1), +.BR unshare (1), +.BR clone (2), +.BR setns (2), +.BR unshare (2), +.BR mq_overview (7), +.BR namespaces (7), +.BR sysvipc (7) |