[Mesa-dev] [PATCH 00/15] GL_AMD_performance_monitor

[Alex Deucher]

On Thu, Mar 19, 2015 at 6:40 PM, Robert Bragg <robert at sixbynine.org> wrote:
> Hi Samuel,
>
> I thought I should let you and others know of some related changes
> I've been playing around with to try and improve our support for the
> INTEL_performance_query extension in the i965 dri driver, since it's
> quite related to your work.
>
> Some of my work-in-progress changes can currently be seen on github here:
> https://github.com/rib/mesa/commits/wip/rib/i915_oa_perf
>
> I've only recently scrubbed up these mesa changes enough for reviewing
> to make much sense, so sorry I haven't sent out an RFC to the list
> before now about this.
>
> What I was finding is that it's not very helpful in practice to
> support the AMD_performance_monitor + INTEL_performance query
> extensions via the same core infrastructure and so since there weren't
> previously any other drivers implementing AMD_performance_monitor, my
> series currently just drops the combined infrastructure in favour of
> core support for just INTEL_performance_query.
>
> The main thing here that might be interesting to think about with
> respect to your work, is whether you might like to do anything
> differently with the main/performance_monitor.c support if you were
> the only user and if it strictly only dealt with the
> AMD_performance_monitor extension?
>
> I don't guess it would be controversial for us to look at removing the
> current i965 backend for both AMD_performance_monitor and
> INTEL_performance_query for an interim if that might be convenient for
> you to evolve the backend interface. (Currently the i965 backend
> doesn't report many usable metrics unfortunately - mainly just the
> pipeline statistics that are also accessible via query objects.) Ken
> and Petri who did much of the work here are already aware that I've
> been taking this approach as I ran it by them some time ago and their
> work still carries forward in the series I have but instead focused
> only on INTEL_performance_query for now.
>
> Anyway, I just thought I should throw that out there as a possibility
> to consider in case it might be helpful.

I would prefer to keep support for AMD_performance_monitor in mesa.
We may implement more extensive support for this extension in our
radeon open source drivers and it would be nice to be compatible with
our closed source drivers on both Linux and other OSes.

Alex