Bug 409036

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