Full screen glxgears stuttering on Wayland (due to i915 driver)
Affected version
Ubuntu 24.04
Mutter: 46.0-1ubuntu9
GPU model: Intel Corporation Meteor Lake-P [Intel Arc Graphics]
Graphics driver in use: i915
Bug summary
Frame drops when running glxgears in fullscreen mode.
The issue only appears in Wayland.
Add CLUTTER_PAINT=disable-dynamic-max-render-time fixes it
Steps to reproduce
- run glxgears in fullscreen mode
- observe the fps
What happened
$ glxgears -fullscreen
Running synchronized to the vertical refresh. The framerate should be
approximately the same as the monitor refresh rate.
300 frames in 5.0 seconds = 59.810 FPS
227 frames in 5.0 seconds = 45.341 FPS
159 frames in 5.0 seconds = 31.749 FPS
168 frames in 5.0 seconds = 33.428 FPS
176 frames in 5.0 seconds = 35.128 FPS
194 frames in 5.0 seconds = 38.714 FPS
286 frames in 5.0 seconds = 56.876 FPS
287 frames in 5.0 seconds = 57.068 FPS
What did you expect to happen
The framerate should be stable and approximately the same as the monitor refresh rate.
Relevant logs, screenshots, screencasts etc.
journalctl -f /usr/bin/gnome-shell (with CLUTTER_SHOW_FPS=1 COGL_DEBUG=sync-frame)
Jun 05 13:45:51 TRMB-DVT2-C6 gnome-shell[3491]: *** eDP-1 frame timings over 1.0s: 47.00 FPS, average: 0.2ms, peak: 0.3ms
Jun 05 13:45:52 TRMB-DVT2-C6 gnome-shell[3491]: *** eDP-1 frame timings over 1.0s: 51.00 FPS, average: 0.2ms, peak: 0.3ms
Jun 05 13:45:53 TRMB-DVT2-C6 gnome-shell[3491]: *** eDP-1 frame timings over 1.0s: 39.34 FPS, average: 0.2ms, peak: 0.3ms
Jun 05 13:45:54 TRMB-DVT2-C6 gnome-shell[3491]: *** eDP-1 frame timings over 1.0s: 35.00 FPS, average: 0.2ms, peak: 0.3ms
Jun 05 13:45:55 TRMB-DVT2-C6 gnome-shell[3491]: *** eDP-1 frame timings over 1.0s: 37.38 FPS, average: 0.2ms, peak: 0.3ms
Jun 05 13:45:56 TRMB-DVT2-C6 gnome-shell[3491]: *** eDP-1 frame timings over 1.0s: 40.00 FPS, average: 0.2ms, peak: 0.3ms
Jun 05 13:45:57 TRMB-DVT2-C6 gnome-shell[3491]: *** eDP-1 frame timings over 1.0s: 45.00 FPS, average: 0.2ms, peak: 0.3ms
Jun 05 13:45:58 TRMB-DVT2-C6 gnome-shell[3491]: *** eDP-1 frame timings over 1.0s: 36.39 FPS, average: 0.2ms, peak: 0.3ms
Jun 05 13:45:59 TRMB-DVT2-C6 gnome-shell[3491]: *** eDP-1 frame timings over 1.0s: 31.47 FPS, average: 0.2ms, peak: 0.3ms
Jun 05 13:46:00 TRMB-DVT2-C6 gnome-shell[3491]: *** eDP-1 frame timings over 1.0s: 33.88 FPS, average: 0.3ms, peak: 0.5ms