[Intel-gfx] [PATCH] drm/i915: enable HiZ Raw Stall Optimization

[Daniel Vetter]

On Mon, Jan 27, 2014 at 9:33 AM, Chia-I Wu <olvaffe at gmail.com> wrote:
> [Additional comments, and copy Ian and Chad for real]
>
> On Mon, Jan 27, 2014 at 4:18 PM, Chia-I Wu <olvaffe at gmail.com> wrote:
>> From: Chia-I Wu <olv at lunarg.com>
>>
>> The optimization is available on Ivy Bridge and later, and is disabled by
>> default.  Enabling it helps certain workloads such as GLBenchmark TRex test.
> With the patch applied, GLB27_TRex_C24Z16_FixedTimeStep goes from
> 99fps to 109fps on my Haswell, and from 60fps to 65fps on my Ivy
> Bridge.  No piglit regression on both GENs.
>
> I had a non-recoverable system hang once with the patch applied.  I
> was not sure if it is because of the patch or drm-intel-nightly (which
> I checkout out some weeks ago).  I did my tests today against latest
> drm-intel-next, and did not have any hang.  Since the optimization is
> disabled by default, I am curious if there is any caveat before
> enabling it.

Chad's still missing ;-) Also the hang might just be ppgtt fallout,
there's still a few regressions with that.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch