tree 68ff4165c8cab6f029a713e3a0a084f16f384ce6
parent 82fe9b0da0d50e2795a49c268676fd132cbc3eea
author Tejun Heo <tj@kernel.org> 1372186417 -0700
committer Tejun Heo <tj@kernel.org> 1372186417 -0700

cgroup: implement for_each_[builtin_]subsys()

There are quite a few places where all loaded [builtin] subsys are
iterated.  Implement for_each_[builtin_]subsys() and replace manual
iterations with those to simplify those places a bit.  The new
iterators automatically skip NULL subsystems.  This shouldn't cause
any functional difference.

Iteration loops which scan all subsystems and then skipping modular
ones explicitly are converted to use for_each_builtin_subsys().

While at it, reorder variable declarations and adjust whitespaces a
bit in the affected functions.

v2: Add lockdep_assert_held() in for_each_subsys() and add comments
    about synchronization as suggested by Li.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>