tree e2c09e4f265f3c2df2bb3fc2a5aff19165aa4135
parent c80ef9e0c021ff86771fdd72583c75d8f7b6a720
author Aleksa Sarai <cyphar@cyphar.com> 1433548934 +1000
committer Tejun Heo <tj@kernel.org> 1433755052 +0900

cgroup: use bitmask to filter for_each_subsys

Add a new macro for_each_subsys_which that allows all enabled cgroup
subsystems to be filtered by a bitmask, such that mask & (1 << ssid)
determines if the subsystem is to be processed in the loop body (where
ssid is the unique id of the subsystem).

Also replace the need_forkexit_callback with two separate bitmasks for
each callback to make (ss->{fork,exit}) checks unnecessary.

tj: add a short comment for "if (!CGROUP_SUBSYS_COUNT)".

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>