[Intel-xe] [PATCH v2 2/2] drm/xe/pmu: Enable PMU interface

[Dixit, Ashutosh]

On Mon, 24 Jul 2023 02:00:13 -0700, Ursulin, Tvrtko wrote:
>
>
> [Top-post since my dual email setup and this is the wrong one, sorry.]
>
> Glancing over the discussion - small correction - i915 did not solve the
> problem of hardware counters and sleeping device with the timer but with
> the park/unpark hooks.
>
> More similar to these group busyness counters would be the RC6, and you
> will notice there is nothing in the i915 sampling timer about RC6. There
> is just some complicated code in park/unpark to estimate RC6 while
> parked. But the estimation is beside the point for engine group busyness
> since it is the opposite metric (grows on busy vs grows idle).
>
> And I think you converged to the same solution already, so I just wanted
> to correct the 5ms timer inaccuracy.

Agreed. For a moment I was fantasizing that the timer would not be needed
in i915 either and we could just sample the values when parking, but that's
not true.

Ashutosh