Heavy mouse cursor lags when GPU utilized at 100%
Affected version
- OS: Fedora 34
- Mutter version: 40.1-2
- Mesa: 21.1.1
- Issue appear only in Wayland
Hardware
- CPU: Ryzen 3300X
- GPU: Radeon VII
Bug summary
Not sure is this a proper place for reporting this bug since it reproducible on GNOME-Wayland, KDE-Wayland and Sway. The problem is that when GPU loaded at 100% and some 3D application running in windowed mode the desktop experience become terrible because of huge mouse cursors lags and stutters. The problem is not occurs on Xorg session at all and no matter how many FPS application running and under heavy GPU utilization.
The problem is not limited just to this scenario and sometimes small stutters may occurs just by using desktop and mouse experience in general inconsistent compared to Xorg.
Steps to reproduce
- Run Wayland session in DE/WM such GNOME, KDE/Kwin, Sway.
- Run something which could utilize your GPU at 100%: rendering software or Hashcat app which usually available in official repos for example (
hashcat -b). - Run in same time benchmark software. Tiny GpuTest would enough. Download and extract.
- Run
./GpuTest /test=pixmark_piano /width=1920 /height=1080.
What happened
Mouse cursor starts stuttering, experience is very poor 2-40 FPS, sometimes cursor could stuck even for few seconds. Basically desktop unusable.
What did you expect to happen
Same experience as in Xorg session — no mouse lags at all, smooth and perfect.
Relevant logs, screenshots, screencasts etc.
Screencast demo: 07.06.2021_19_37_28