• Paul Jackson's avatar
    [PATCH] cpuset: skip rcu check if task is in root cpuset · 03a285f5
    Paul Jackson authored
    
    
    For systems that aren't using cpusets, but have them CONFIG_CPUSET enabled in
    their kernel (eventually this may be most distribution kernels), this patch
    removes even the minimal rcu_read_lock() from the memory page allocation path.
    
    Actually, it removes that rcu call for any task that is in the root cpuset
    (top_cpuset), which on systems not actively using cpusets, is all tasks.
    
    We don't need the rcu check for tasks in the top_cpuset, because the
    top_cpuset is statically allocated, so at no risk of being freed out from
    underneath us.
    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>
    03a285f5