ipc_namespaces

IPC_NAMESPACES(7)          Linux Programmer's Manual         IPC_NAMESPACES(7)

NAME
       ipc_namespaces - overview of Linux IPC namespaces

DESCRIPTION
       IPC  namespaces isolate certain IPC resources, namely, System V IPC ob-
       jects (see sysvipc(7)) and (since Linux 2.6.30)  POSIX  message  queues
       (see  mq_overview(7)).   The  common characteristic of these IPC mecha-
       nisms 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  name-
       space are visible to all other processes that are members of that name-
       space, 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, ms-
          gmnb, 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
       This  page  is  part of release 5.05 of the Linux man-pages project.  A
       description of the project, information about reporting bugs,  and  the
       latest     version     of     this    page,    can    be    found    at
       https://www.kernel.org/doc/man-pages/.

Linux                             2019-08-02                 IPC_NAMESPACES(7)