Bug 103175

Summary: R9285 Unreal tournament perf regression with agd5f 4.15-wip kernels possibly CPU related
Product: DRI Reporter: Andy Furniss <adf.lists>
Component: DRM/AMDgpuAssignee: Default DRI bug account <dri-devel>
Status: RESOLVED DUPLICATE QA Contact:
Severity: normal    
Priority: medium    
Version: DRI git   
Hardware: Other   
OS: All   
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
good perf gallium hud on 4.14 kernel.
none
bad on previous 4.15 kernel cpu load different.
none
bad on latest 4.15-wip cpu still different but not as obvious. none

Description Andy Furniss 2017-10-09 17:31:58 UTC
Created attachment 134765 [details]
good perf gallium hud on 4.14 kernel.

R9285 Tonga, Compared to older kernels I have a perf regression with latest 4.14.0-rc3 based and previous 4.13-rc5 based agd5f 4.15-wip kernels.

This doesn't seem to affect other things like xonotic or unigine demos.

Issue = on fixes 4.14 and other older kernels I've tried, the game is OK ish perf wise, 25-60 fps.

On 4.15-wip its 10fps. Using HUD one obvious difference is that the slow case is only mostly using one cpu core, on a good kernel all 4 of my old phenom 2 x4 are used - possible red herring of course, I'll upload some screenshots.

The game is pre-alpha and doesn't always render properly - but it was vaguely playable fps wise until this kernel.
Comment 1 Andy Furniss 2017-10-09 17:33:38 UTC
Created attachment 134766 [details]
bad on previous 4.15 kernel cpu load different.

All tests done with both CPUs and GPU forced to perf.
Comment 2 Andy Furniss 2017-10-09 17:35:25 UTC
Created attachment 134767 [details]
bad on latest 4.15-wip cpu still different but not as obvious.
Comment 3 Michel Dänzer 2017-10-10 08:27:08 UTC
According to the HUD, the GPU load is actually higher in the bad cases. Have you checked what clocks the GPU runs at in each case?
Comment 5 Andy Furniss 2017-10-10 09:01:27 UTC
I had that fix and a couple of others on the first 4.15-wip I tried. They are in now AFAICT. I see Alex updated again since yesterday so I'll try that one later.

I did notice but forgot to highlight the GPU difference.
Given all the powerplay changes in 4.15-wip I do wonder if all is well but I would have expected Unigine/Xonotic to show it if something was wrong there.

One thing different about UT is it asks for more vram than I have, maybe that makes it stand out from other tests.

After posting this I did wonder whether the CPU difference is just because the fps is low and not the cause.

4.15-wip doesn't work for me going away from head (will throw  some vmfaults and then lock soon after startx) so bisecting is not an easy option.
Comment 6 Andy Furniss 2017-10-11 09:59:00 UTC
I tried latest 4.15-wip and it's still low perf.
On this test the perf was OK ish initially but degraded over the first 20 seconds.

For added hassle it seems that between 4.13 and 4.14-rc1 something changed that means I may hard lock when configuring ffmpeg! I am trying to find that one on linus git, but now agd5f have been rebased they are not stable for me.
Comment 7 Andy Furniss 2017-11-15 21:48:00 UTC
This is OK now with amd-staging-drm-next, I'll close when 4.15s get updated assuming they get whatever fixed it as well.
Comment 8 Andy Furniss 2017-11-16 15:35:01 UTC
It's not OK, I don't know what happened there, maybe I wasn't in the kernel I thought, though I am not convinced.
Whatever the reason, I can't get it to work now.
Comment 9 Andy Furniss 2017-11-22 00:44:36 UTC
possibly this is

https://bugs.freedesktop.org/show_bug.cgi?id=103100

Though I am not sure as I lock soon after startx if on the commit called there

On the commit before I am OK and UT perf is good.
Comment 10 Andy Furniss 2017-11-22 11:42:55 UTC
Testing from head of drm-next-4.15 I can change minor to 19 and 20 in
drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
and am stable so can test.

19 gives good perf 20 bad, so setting as duplicate.

*** This bug has been marked as a duplicate of bug 103100 ***

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