Re: [PATCH] sched: Don't allow priority switch to realtime when the task doesn't belong to init_task_group and when CONFIG_RT_GROUP_SCHED isn't set

[Peter Zijlstra <a.p.zijlstra@chello.nl>]

On Tue, 2008-11-25 at 12:51 -0600, Chris Friesen wrote:
> Peter Zijlstra wrote:
> > On Mon, 2008-11-24 at 09:24 -0600, Chris Friesen wrote:
> > 
> >>Peter Zijlstra wrote:
> 
> >>>Furthermore your statement shows another misconception, a group of
> >>>ungrouped tasks doesn't make sense.
> >>
> >>Arguably there is such a group, which is "the set of all RT tasks".
> > 
> > 
> > Sure, I understand that, and in fact that's how its implemented, no
> > group is still one group (which is how you can bootstrap math from
> > group/set theory).
> > 
> > But its not a manageable group in the cgroup sense, its just the
> > collection of RT tasks.
> 
> True, but it would be valuable to have statistics for how much cpu time 
> the RT tasks are consuming.

True, I have patches for that though, and this is unrelated to cgroups.

The more interesting thing is using that time to scale the sched_other
balancing.