[Intel-gfx] [PATCH] drm/i915: Make sample_c messages go faster on Haswell.

[Daniel Vetter]

On Fri, Nov 07, 2014 at 10:46:31AM -0800, Matt Turner wrote:
> On Wed, Oct 29, 2014 at 2:12 PM, Kenneth Graunke <kenneth at whitecape.org> wrote:
> > Haswell significantly improved the performance of sampler_c messages,
> > but the optimization appears to be off by default.  Later platforms
> > remove this bit, and apparently always enable the optimization.
> >
> > Improves performance in "Counter Strike: Global Offensive" by 18%
> > at default settings on Iris Pro.  No Piglit regressions.
> 
> Discussion seems to have ended, but Mesa really needs this.
> 
> So, Kernel Team, how are we going to make sure Mesa gets this 18%
> performance improvement?

Someone writes the patches+tests and everything, gets it all reviewed and
I'll merge it.

I'd prefer if we could do this with the cmd parser, but that thing seems
to be eternally stuck. So a new execbuf flag is imo ok too. execbuf
already tracks a few other lonesome bits and makes sure userspace actually
gets the setting it requests, so should work out.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch