SUMMARY Each time I plug in my external screen, kwin just freezes up with 100% CPU load. I need to SIGKILL it from a tty (SIGTERM is being ignored), and then somehow get the desktop session to work again. SOFTWARE/OS VERSIONS Operating System: Debian GNU/Linux KDE Plasma Version: 5.26.0 KDE Frameworks Version: 5.98.0 Qt Version: 5.15.6 Kernel Version: 6.0.0-2-amd64 (64-bit) Graphics Platform: X11 Processors: 8 × Intel® Xeon® CPU E3-1505M v5 @ 2.80GHz Memory: 31,2 GiB of RAM Graphics Processor: Mesa Intel® HD Graphics P530 Manufacturer: LENOVO Product Name: 20ENCTO1WW System Version: ThinkPad P50 ADDITIONAL INFORMATION This is just the last in a series of crash/freeze/hang bugs that kwin_x11 is suffering from recently. I am not sure if there is something odd about my system or if nobody is using KDE on X11 any more and hence those codepaths are just bitrotting.
> nobody is using KDE on X11 any more and hence those codepaths are just bitrotting None of the KWin developers are, at least. So this is a very likely scenario. Is this a regression in Plasma 5.26?
Yes this started after upgrading to Plasma 5.26.0 from some 5.25.x. I am now using the wayland session and experiencing various problems there -- will file / have filed those as separate bugreports.
We haven't had any duplicate reports on X11. Not have we duplicated it in X11 testing. It could be caused by a rogue kwin script or other third party? Can you check you have none enabled. Please can you confirm if it's still an issue on 5.27? I'll close this report as there isn't enough information to do anything too useful, but if you can reproduce please run: sudo perf record --call-graph dwarf -p (`pidof kwin_x11`) and share the log
I have switched to Wayland to avoid all these X11 issues, and am not able to reproduce this any more.