Bug 489665

Summary:	KWin (x11) hangs when ALT - TAB pressed after suspend/resume
Product:	[Plasma] kwin	Reporter:	LyCC <flevi99>
Component:	tabbox	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	nate
Priority:	NOR	Keywords:	X11-only
Version First Reported In:	6.1.1
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description LyCC 2024-07-03 09:09:00 UTC

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SUMMARY

KWin (x11) hangs when ALT - TAB pressed after suspend/resume. kwin process goes 100% CPU, GUI goes unresponsive, when the process is killed, GUI works again until next alt-tab. Works perfectly fine on first boot, until sleep/resume.


STEPS TO REPRODUCE
1.  sleep computer with multiple windows opened
2.  resume
3.  press alt-tab when multiple windows are opened

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 6.1.1
KDE Frameworks Version: 6.3.0
Qt Version:  6.7.2

Comment 1 LyCC 2024-07-14 17:05:42 UTC

Disabling "compact/thumbnail/etc" combo fixes the issue. 

Quick windows switching where the preview bar does not appears is working, however, pressing longer ALT-TAB hangs the 
/usr/bin/kwin_x11 --replace 
process with 100 CPU usage and the entire GUI becomes unresponsive until this process is killed.

Comment 2 TraceyC 2025-02-24 17:58:34 UTC

Adding the x11-only keyword