20 Oct, 2007

1 commit

• 858d72ead   cgroups: implement namespace tracking subsystem ... Browse Code »

  When a task enters a new namespace via a clone() or unshare(), a new cgroup
  is created and the task moves into it.

  This version names cgroups which are automatically created using
  cgroup_clone() as "node_" where pid is the pid of the unsharing or
  cloned process. (Thanks Pavel for the idea) This is safe because if the
  process unshares again, it will create

  /cgroups/(...)/node_/node_

  The only possibilities (AFAICT) for a -EEXIST on unshare are

  1. pid wraparound
  2. a process fails an unshare, then tries again.

  Case 1 is unlikely enough that I ignore it (at least for now). In case 2, the
  node_ will be empty and can be rmdir'ed to make the subsequent unshare()
  succeed.

  Changelog:
  Name cloned cgroups as "node_".

  [clg@fr.ibm.com: fix order of cgroup subsystems in init/Kconfig]
  Signed-off-by: Serge E. Hallyn
  Cc: Paul Menage
  Signed-off-by: Cedric Le Goater
  Signed-off-by: Andrew Morton
  Signed-off-by: Linus Torvalds

  Serge E. Hallyn

  2007-10-20 02:53:37 +0800