Re: [PATCH] sched: Relax a restriction in sched_rt_can_attach()

Mike Galbraith
2015-05-04T14:09:42Z

On Mon, 2015-05-04 at 14:37 +0200, Peter Zijlstra wrote:
> On Mon, May 04, 2015 at 05:11:10PM +0800, Zefan Li wrote:
>
> > Some degree of flexibility is provided so that you may disable some controllers
> > in a subtree. For example:
> >
> > root ---> child1
> > (cpuset,memory,cpu) (cpuset,memory)
> > \
> > \-> child2
> > (cpu)
>
> Uhm, how does that work? Would a task their effective cgroup be the
> first parent that has a controller enabled?
>
> In particular, in your example, if T were part of child1, would its cpu
> controller be root?

That's what I'd hope for. I wanted to try that cgroup.subtree_control
gizmo to see for myself, but I don't have one, and probably won't get
one until I introduce systemd to my axe (again, it's a slow learner).

-Mike