ipc_namespaces(7) - man - phpman

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 objects (see sysvipc(7))
       and (since Linux 2.6.30) POSIX message queues (see mq_overview(7)).  The common  characteris‐
       tic  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 name‐
       space 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  5.10 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)