[Intel-gfx] [PATCH v3] drm/i915: Enable WaProgramMgsrForCorrectSliceSpecificMmioReads for Gen9

[Tvrtko Ursulin]

Hi,

On 08/03/2021 17:32, Chiou, Cooper wrote:
> I've tested on GLK, KBL, CFL Intel NUC devices and got the following performance results, there is no performance regression per my testing.
> 
> Patch: [v5] drm/i915: Enable WaProgramMgsrForCorrectSliceSpecificMmioReads for Gen9
> Test suite: phoronix-test-suite.supertuxkart.1024x768.Fullscreen.Ultimate.1.GranParadisoIsland.frames_per_second
> Kernel version: 5.12.0-rc1 (drm-tip)
> 
> a. Device: Intel NUC kit NUC7JY Gemini Lake Celeron J4005 @2.7GHz (2 Cores)
>      Without patch, fps=57.45
>      With patch, fps=57.49
> b. Device: Intel NUC kit NUC8BEH Coffee Lake Core i3-8109U @3.6GHz(4 Cores)
>      Without patch, fps=117.23
>      With patch, fps=117.27
> c. Device: Intel NUC kit NUC7i3BNH Kaby Lake Core i3-7100U @2.4GHz(4 Cores)
>      Without patch, fps=114.05
>      With patch, fps=114.34
> 
> Meanwhile, Intel lkp team has validated performance on lkp-kbl-nuc1 and no regression.
> f69d02e37a85645a  d912096c40cdc3bc9364966971 testcase/testparams/testbox
> ----------------  -------------------------- ---------------------------
>            %stddev      change         %stddev
>                \          |                \
>        29.79                       29.67
> phoronix-test-suite/performance-true-Fullscreen-Ultimate-1-Gran_Paradiso_Island__Approxima-supertuxkart-1.5.2-ucode=0xde/lkp-kbl-nuc1
>        29.79                       29.67        GEO-MEAN phoronix-test-suite.supertuxkart.1280x1024.Fullscreen.Ultimate.1.GranParadisoIsland.frames_per_second
> 

CI results are green so that is good.

Do the machines used for performance testing include unusual fusing? 
Worrying thing is that we were never able to reproduce the reported 
regression in house due lack of identical machine, right? Although I 
guess avoiding hangs trumps performance.

Regards,

Tvrtko