Re: [RFC 4/8] Improve the tracking of active utilisation

[luca abeni]

Hi Peter,

On Wed, 27 Jan 2016 15:39:46 +0100
Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> On Wed, Jan 27, 2016 at 02:36:51PM +0100, Luca Abeni wrote:
> > Ok, so I implemented this idea, and I am currently testing it...
> > The first experiments seem to show that there are no problems, but I
> > just tried some simple workload (rt-app, or some other periodic
> > taskset scheduled by SCHED_DEADLINE). Do you have suggestions for
> > more "interesting" (and meaningful) tests/experiments?
> 
> rt-app is the workload generator, right?
> 
> I think the most interesting part here is the switched_from path, so
> you'd want the workload to include a !rt task that gets PI boosted to
> deadline every so often.
I am looking at the PI stuff right now... And I am not sure if
SCHED_DEADLINE does the right thing for PI :)

Anyway, I think the total SCHED_DEADLINE utilization (rd->dl_bw) is
currently not changed when a SCHED_OTHER task is boosted to
SCHED_DEADLINE due to PI... Right? Is this the desired behaviour?
If yes, I'll make sure that my patch does not change it.



			Thanks,
				Luca