Re: [RFC 10/11] drm/i915: Export engine stats API to other users

Rogozhkin, Dmitry V
2017-09-19T20:11:34Z

On Tue, 2017-09-19 at 12:50 -0700, Ben Widawsky wrote:
> On 17-09-15 10:49:56, Tvrtko Ursulin wrote:
> >
> >On 14/09/2017 21:26, Chris Wilson wrote:
> >>Quoting Tvrtko Ursulin (2017-09-11 16:25:58)
> >>>From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> >>>
> >>>Other kernel users might want to look at total GPU busyness
> >>>in order to implement things like package power distribution
> >>>algorithms more efficiently.
> >>
> >>Who are we exporting these symbols to? Will you not need all the module
> >>ref handling and load ordering like around ips and audio?
> >
> >Hm yes indeed, I forgot about that.
> >
> >Perhaps Ben could comment on who is the user. If it is purely for
> >internal explorations, I'll stick the patch at the end of the series
> >as it is. If it has a more serious user I would need to implement a
> >proper solution.
> >
> >Regards,
> >
> >Tvrtko
>
> P-state driver was looking to use this as a way to make determinations about how
> much to limit CPU frequency. Srinivas was privy to the original discussion
>

I personally was surprised to see private API exposed rather than reuse
of PMU API. Do they really need a private path?