[Intel-gfx] [PATCH igt 3/3] igt/perf_pmu: Idle the GPU before starting to measure busyness

[Chris Wilson]

Quoting Chris Wilson (2017-11-23 16:02:20)
> Quoting Tvrtko Ursulin (2017-11-23 13:37:30)
> > 
> > On 23/11/2017 08:22, Chris Wilson wrote:
> > > Make sure the HW is idle before we start sampling the GPU for busyness.
> > > If we do not rest for long enough between tests, we may carry the
> > > sampling over.
> > 
> > I'd rather not have this since as I said yesterday each opened PMU event 
> > is supposed to record the initial counter value as reference. If that is 
> > failing or not good enough on some tests/platforms I would rather first 
> > understand why and how.
> 
> All legacy sampling fails... :| I'm putting it back!

So presumably it is coupling with the parking.
-Chris