kernel: cgroup: push rcu read locking from css_is_ancestor() to callsite

Library functions should not grab locks when the callsites can do it,
even if the lock nests like the rcu read-side lock does.

Push the rcu_read_lock() from css_is_ancestor() to its single user,
mem_cgroup_same_or_subtree() in preparation for another user that may
already hold the rcu read-side lock.

Signed-off-by: Johannes Weiner <[email protected]>
Cc: Konstantin Khlebnikov <[email protected]>
Acked-by: KAMEZAWA Hiroyuki <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Acked-by: Li Zefan <[email protected]>
Cc: Li Zefan <[email protected]>
Cc: Tejun Heo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions