• Paul Jackson's avatar
    [PATCH] cpusets: simple rename · 18a19cb3
    Paul Jackson authored
    
    
    Add support for renaming cpusets.  Only allow simple rename of cpuset
    directories in place.  Don't allow moving cpusets elsewhere in hierarchy or
    renaming the special cpuset files in each cpuset directory.
    
    The usefulness of this simple rename became apparent when developing task
    migration facilities.  It allows building a second cpuset hierarchy using
    new names and containing new CPUs and Memory Nodes, moving tasks from the
    old to the new cpusets, removing the old cpusets, and then renaming the new
    cpusets to be just like the old names, so that any knowledge that the tasks
    had of their cpuset names will still be valid.
    
    Leaf node cpusets can be migrated to other CPUs or Memory Nodes by just
    updating their 'cpus' and 'mems' files, but because no cpuset can contain
    CPUs or Nodes not in its parent cpuset, one cannot do this in a cpuset
    hierarchy without first expanding all the non-leaf cpusets to contain the
    union of both the old and new CPUs and Nodes, which would obfuscate the
    one-to-one migration of a task from one cpuset to another required to
    correctly migrate the physical page frames currently allocated to that
    task.
    
    Signed-off-by: default avatarPaul Jackson <pj@sgi.com>
    Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
    18a19cb3