• Tejun Heo's avatar
    cgroup: drop module support · 3ed80a62
    Tejun Heo authored
    With module supported dropped from net_prio, no controller is using
    cgroup module support.  None of actual resource controllers can be
    built as a module and we aren't gonna add new controllers which don't
    control resources.  This patch drops module support from cgroup.
    
    * cgroup_[un]load_subsys() and cgroup_subsys->module removed.
    
    * As there's no point in distinguishing IS_BUILTIN() and IS_MODULE(),
      cgroup_subsys.h now uses IS_ENABLED() directly.
    
    * enum cgroup_subsys_id now exactly matches the list of enabled
      controllers as ordered in cgroup_subsys.h.
    
    * cgroup_subsys[] is now a contiguously occupied array.  Size
      specification is no longer necessary and dropped.
    
    * for_each_builtin_subsys() is removed and for_each_subsys() is
      updated to not require any locking.
    
    * module ref handling is removed from rebind_subsystems().
    
    * Module related comments dropped.
    
    v2: Rebased on top of fe1217c4
    
     ("net: net_cls: move cgroupfs
        classid handling into core").
    
    v3: Added {} around the if (need_forkexit_callback) block in
        cgroup_post_fork() for readability as suggested by Li.
    Signed-off-by: default avatarTejun Heo <tj@kernel.org>
    Acked-by: default avatarLi Zefan <lizefan@huawei.com>
    3ed80a62