Created attachment 132646 [details] [review]
hack to apitrace for duplicating problem
We have an internal OpenGL benchmarking tool that measures the performance =
of
certain frames in apitrace files. We have been using this tool to measure
the performance of various releases of Mesa.
We recently found a large regression in Mesa performance of Half Life Episo=
de
2, as measured by our benchmarking tool. We measured the following frame ra=
tes
when running the benchmark with Mesa built from the listed source tags:
tag mesa-17.0.0 358.6 fps
tag mesa-17.1.3 151.1 fps
This is a reduction in performance of more than 2X.
Since the tool we use to measure performance is an internal tool and we can=
not
distribute it, I hacked apitrace to behave similar to our tool so that apit=
race
can be used to measure the performance of the problem frame. The frame rat=
es I
measured with this hacked apitrace benchmark are:
tag mesa-17.0.0 417.7 fps
commit 071d80b 393.9 fps
commit f81ede4 324.6 fps
tag mesa-17.1.3 196.0 fps
The hacked apitrace shows about the same performance drop between mesa-17.0=
.0
and mesa-17.1.3 as our original benchmark. I also include the results for
commits 071d80b and f81ede4 because commit f81ede4 seemed to show the single
largest performance drop of all commits between mesa-17.0.0 and mesa-17.1.3.
The configuration of the system I have been using to measure Mesa performan=
ce
is:
CPU: Intel(R) Core(TM) i5-6600K CPU @ 3.50GHz
RAM: 16Gb
GPU: AMD RX480
Attached is the patch I applied to apitrace to create my hacked apitrace th=
at
attempts to duplicate the original benchmark.
After building apitrace with the above patch, I used the following command =
to
measure performance:
vblank_mode=3D0 glretrace -b hl2_linux.trace
I can make the hl2_linux.trace trace file available on request. We cannot
widely distribute it because it contains Valve IP (i.e. game images). Please
send a request directly to david=
4;lunarg.com.
Note that we have observed similar performance drops for other games, but I
have concentrated on isolating and reporting on one frame in one game for n=
ow.