IPC_NAMESPACES
Section: Linux Programmer's Manual (7)
Updated: 2019-08-02
Page Index
NAME
ipc_namespaces - overview of Linux IPC namespaces
DESCRIPTION
IPC namespaces isolate certain IPC resources,
namely, System V IPC objects (see
sysvipc(7))
and (since Linux 2.6.30)
POSIX message queues (see
mq_overview(7)).
The common characteristic of these IPC mechanisms is that IPC
objects are identified by mechanisms other than filesystem
pathnames.
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.
The following
/proc
interfaces are distinct in each IPC namespace:
- *
-
The POSIX message queue interfaces in
/proc/sys/fs/mqueue.
- *
-
The System V IPC interfaces in
/proc/sys/kernel,
namely:
msgmax,
msgmnb,
msgmni,
sem,
shmall,
shmmax,
shmmni,
and
shm_rmid_forced.
- *
-
The System V IPC interfaces in
/proc/sysvipc.
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.
Use of IPC namespaces requires a kernel that is configured with the
CONFIG_IPC_NS
option.
SEE ALSO
nsenter(1),
unshare(1),
clone(2),
setns(2),
unshare(2),
mq_overview(7),
namespaces(7),
sysvipc(7)
COLOPHON
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man-pages
project.
A description of the project,
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and the latest version of this page,
can be found at
https://www.kernel.org/doc/man-pages/.