Bug 201843

Summary: Micro-stuttering each second on amdgpu only on 2560x1440
Product: Drivers Reporter: Oleg Chernovskiy (kairllur)
Component: Video(DRI - non Intel)Assignee: drivers_video-dri
Status: RESOLVED CODE_FIX    
Severity: normal CC: fin4478
Priority: P1    
Hardware: x86-64   
OS: Linux   
Kernel Version: 4.19.2-arch1-1-ARCH Subsystem:
Regression: No Bisected commit-id:
Attachments: GPU stutter visualized - DOOM
No stutter - DOOM 1920x1080

Description Oleg Chernovskiy 2018-12-02 17:07:08 UTC
Created attachment 279797 [details]
GPU stutter visualized - DOOM

Hello, it's me again.

I notice that in many games if I play on my native screen resolution (2560x1440) the games always have micro-stutter. If I switch to 1920x1080 it is resolved.

Facts:
- The micro-stutter doesn't show up right after launch, you have to play a bit for it to start
- If I set power_dpm_force_performance_level to low and then to high/auto again the micro-stutter disappears and then gradually accumulates again
- I always play with window compositing disabled (KDE)

Hardware info:
System:    Kernel: 4.19.2-arch1-1-ARCH x86_64 bits: 64 compiler: gcc v: 8.2.1 
           Desktop: KDE Plasma 5.14.4 Distro: Arch Linux 
Machine:   Type: Desktop Mobo: ASRock model: X370 Gaming K4 UEFI: American Megatrends 
           v: P4.70 date: 04/18/2018 
CPU:       Topology: 8-Core model: AMD Ryzen 7 1700X bits: 64 type: MT MCP arch: Zen rev: 1 L2 cache: 4096 KiB 
           flags: lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3 svm bogomips: 108626 
           Speed: 1960 MHz min/max: 2200/3400 MHz Core speeds (MHz): 1: 1943 2: 1966 3: 3270 4: 3224 5: 2247 
           6: 2317 7: 3084 8: 3224 9: 3447 10: 3390 11: 2669 12: 2669 13: 3194 14: 3067 15: 3220 16: 3329 
Graphics:  Device-1: Advanced Micro Devices [AMD/ATI] Ellesmere [Radeon RX 470/480/570/570X/580/580X] 
           driver: amdgpu v: kernel bus ID: 26:00.0 
           Display: x11 server: X.Org 1.20.3 driver: modesetting unloaded: fbdev,vesa 
           resolution: 2560x1440~60Hz 
           OpenGL: renderer: AMD Radeon RX 480 Graphics (POLARIS10 DRM 3.27.0 4.19.2-arch1-1-ARCH LLVM 7.0.0) 
           v: 4.5 Mesa 18.2.5 direct render: Yes 
Info:      Memory: 31.41 GiB used: 12.89 GiB (41.0%)

Misc:

Total Samples: 
76167 (6.493KHz)
    amdgpu:amdgpu_mm_rreg: 
1527 (1527 samples, 2% of total, 130.2Hz)
    amdgpu:amdgpu_mm_wreg: 
97 (97 samples, 0.127% of total, 8.269Hz)
    WARNING: 
Sampling frequency below 100Hz
    amdgpu:amdgpu_iv: 
1520 (1520 samples, 2% of total, 129.6Hz)
    amdgpu:amdgpu_cs: 
2426 (2426 samples, 3.19% of total, 206.8Hz)
    amdgpu:amdgpu_cs_ioctl: 
1190 (1190 samples, 1.56% of total, 101.4Hz)
    amdgpu:amdgpu_vm_bo_mapping: 
1.297E+04 (1.297E+04 samples, 17% of total, 1.105KHz)
    amdgpu:amdgpu_vm_bo_cs: 
1.399E+04 (1.399E+04 samples, 18.4% of total, 1.193KHz)
    amdgpu:amdgpu_bo_list_set: 
4.126E+04 (4.126E+04 samples, 54.2% of total, 3.518KHz)
    amdgpu:amdgpu_cs_bo_status: 
1188 (1188 samples, 1.56% of total, 101.3Hz)
Comment 1 Oleg Chernovskiy 2018-12-02 17:10:03 UTC
Created attachment 279799 [details]
No stutter - DOOM 1920x1080

Attacting sample in 1920x1080 without stuttering, same PC, same hardware, same screen
Comment 2 fin4478 2018-12-02 18:36:59 UTC
You are using old kernel and Mesa and the problem can be in the game, DXVK and wine. Use 4.20-rc4 or AMD drm-next-4.21-wip kernel and Mesa git. Arch linux has Mesa git but it is older than Oibaf ppa Mesa. I could not see any difference in your pictures. You can adjust game settings too. AMD developers have better to do than react this kind of bug reports.
Comment 3 Oleg Chernovskiy 2018-12-02 19:36:08 UTC
> I could not see any difference in your pictures.

Okay, please explain what GPU is doing exactly once per second on the graphs when I look at nothing but the wall in the game?

> AMD developers have better to do than react this kind of bug reports.

You too

> You are using old kernel and Mesa and the problem can be in the game, DXVK
> and wine. 

- I'm not using DXVK
- This bug also affects native games
- I'll retest it on new kernel and mesa if _real_ AMD developers say so
Comment 4 Oleg Chernovskiy 2018-12-09 08:39:05 UTC
Did an upgrade to 4.20 (Alex Deucher branch), Mesa 19 and this is indeed resolved. Apologies to the previous commenter.