SUMMARY After upgrade from plasma 6.1.90 to 6.2.0 the performance is heavily regressed. The mouse stutters every second when moved over a window and very heavily stuttering when touching the task bar. Performance is fine when only showing desktop. STEPS TO REPRODUCE 1. Open a terminal in a full screen 2. Move the mouse over the terminal and out to the taskbar area OBSERVED RESULT Heavy mouse and system stutter. CPU shows ~25% load for the app, plasmashell and kwin_wayland EXPECTED RESULT No stutter or increased CPU load is observed. SOFTWARE/OS VERSIONS Operating System: Fedora Linux 41 KDE Plasma Version: 6.2.0 KDE Frameworks Version: 6.7.0 Qt Version: 6.7.2 Kernel Version: 6.11.2-300.fc41.aarch64 (64-bit) Graphics Platform: Wayland Processors: 4 × ARM Cortex-A53, 2 × ARM Cortex-A72 Memory: 3.7 GiB of RAM Graphics Processor: Mali-T860 Product Name: Pine64 Pinebook Pro ADDITIONAL INFORMATION Everything was working as expected on 6.1.90
Video showing the issue: https://drive.proton.me/urls/FED55JV09M#Bib65kbJxW7h
Can you confirm if performance is still the same after wiping .config/kwinrc
(In reply to David Edmundson from comment #2) > Can you confirm if performance is still the same after wiping .config/kwinrc I've removed said file, rebooted and the issue is still there. I also noticed that overview effect is now broken (shows black screen) and following appears in the logs: Oct 16 15:44:57 kwin_wayland[1575]: kwin_scene_opengl: 0x4: GL_INVALID_OPERATION in glDrawElements Oct 16 15:44:57 kwin_wayland[1575]: kwin_scene_opengl: 0x4: GL_INVALID_OPERATION in glVertexAttribPointer(no array object bound) Oct 16 15:44:57 kwin_wayland[1575]: kwin_scene_opengl: 0x4: GL_INVALID_OPERATION in glVertexAttribPointer(no array object bound) Oct 16 15:44:57 kwin_wayland[1575]: kwin_scene_opengl: 0x4: GL_INVALID_OPERATION in glVertexAttribPointer(no array object bound) Oct 16 15:44:57 kwin_wayland[1575]: kwin_scene_opengl: 0x4: GL_INVALID_OPERATION in glDrawElements I'm waiting for the 6.2.1 to be build for F41, maybe the recent fixes for https://bugs.kde.org/show_bug.cgi?id=492152 will help with this regression as well?
Okay, good news, 6.2.1 fixes the performance regression. The notes for Fedora update mentions this: ``` This update re-applies a patch to fix poor performance when 3D acceleration is not available. It was applied to 6.1.90, but lost in the 6.2.0 update. ``` Which maybe the culprit of the regression? I'm not sure which patch exactly is referenced, but here it is.
For the record, that was tracked as https://bugs.kde.org/show_bug.cgi?id=493295 and fixed with https://invent.kde.org/plasma/kwin/-/commit/9370f7d19e4a047c72981d5b8f46a24eefd7cc83 .
*** This bug has been marked as a duplicate of bug 493295 ***