Bug 409036

Summary:	Random hangs with smart window placement on Wayland
Product:	[Plasma] kwin	Reporter:	Alois Wohlschlager <alois1>
Component:	wayland-generic	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED DUPLICATE
Severity:	grave	CC:	kde
Priority:	NOR
Version First Reported In:	5.16.1
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Alois Wohlschlager 2019-06-22 12:59:07 UTC

SUMMARY
When using the "Smart" window placement mode for KWin, this sometimes leads to a hung KWin.

STEPS TO REPRODUCE
1. Run the Wayland session
2. Make sure the window placement mode is "smart"
3. Open many windows

OBSERVED RESULT
Eventually, KWin will hang. Sysrq-R and examining the situation in a different TTY will show 100% CPU usage for KWin.

EXPECTED RESULT
KWin never hangs.

SOFTWARE/OS VERSIONS
Windows: n/a
macOS: n/a
Linux/KDE Plasma: Arch Linux w/ kernel 5.1.12-arch1-1-ARCH (fully updated as of 2019-06-22)
(available in About System)
KDE Plasma Version: 5.16.1
KDE Frameworks Version: 5.59.0
Qt Version: 5.12.4

ADDITIONAL INFORMATION
This bug does not occur on Xorg or with the "cascading" window placement mode.

Comment 1 David Edmundson 2019-06-22 13:07:01 UTC


*** This bug has been marked as a duplicate of bug 408754 ***