On Wed, Feb 24, 2016 at 05:12:54PM -0500, Tejun Heo wrote: > Some controllers, perf_event for now and possibly freezer in the > future, don't really make sense to control explicitly through > "cgroup.subtree_control". For example, the primary role of perf_event > is identifying the cgroups of tasks; however, because the controller > also keeps a small amount of state per cgroup, it can't be replaced > with simple cgroup membership tests. > > This patch implements cgroup_subsys->implicit_on_dfl flag. When set, > the controller is implicitly enabled on all cgroups on the v2 > hierarchy so that utility type controllers such as perf_event can be > enabled and function transparently. > > An implicit controller doesn't show up in "cgroup.controllers" or > "cgroup.subtree_control", is exempt from no internal process rule and > can be stolen from the default hierarchy even if there are non-root > csses. > > v2: Reimplemented on top of the recent updates to css handling and > subsystem rebinding. Rebinding implicit subsystems is now a > simple matter of exempting it from the busy subsystem check. > > Signed-off-by: Tejun Heo <[email protected]>
Applying this one to cgroup/for-4.6. Waiting for the review of userland part on the second patch. Thanks. -- tejun
