• T
    cgroup: move ->subsys_mask from cgroupfs_root to cgroup · 94419627
    Tejun Heo 提交于
    cgroupfs_root->subsys_mask represents the controllers attached to the
    hierarchy.  This patch moves the field to cgroup.  Subsystem
    initialization and rebinding updates the top cgroup's subsys_mask.
    For !root cgroups, the subsys_mask bits are set from create_css() and
    cleared from kill_css(), which effectively means that all cgroups will
    have the same subsys_mask as the top cgroup.
    
    While this doesn't make any difference now, this will help
    implementation of the default unified hierarchy where !root cgroups
    may have subsets of the top_cgroup's subsys_mask.
    
    While at it, __kill_css() is split out of kill_css().  The former
    doesn't care about the subsys_mask while the latter becomes noop if
    the controller is already killed and clears the matching bit if not
    before proceeding to killing the css.  This will be used later by the
    default unified hierarchy implementation.
    Signed-off-by: NTejun Heo <tj@kernel.org>
    Acked-by: NLi Zefan <lizefan@huawei.com>
    94419627
cgroup.c 128.1 KB