Bug 343260

Summary:	total desktop freeze on alt+tab
Product:	[Plasma] kwin	Reporter:	Nick Shaforostoff <shafff>
Component:	general	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED DUPLICATE
Severity:	grave
Priority:	NOR
Version:	5.1.95
Target Milestone:	---
Platform:	Ubuntu
OS:	Linux
Latest Commit:		Version Fixed In:
Attachments:	kwin backtraces kded backtraces

Description Nick Shaforostoff 2015-01-25 02:05:03 UTC

i have ubuntu vivid updated to latest packages with dist-upgrade on my netbook with atom n2600 (powervr gpu). i have a simple alt-tab switcher that displays windows as large icons on the bar appearing on the left side. 


Reproducible: Always

Steps to Reproduce:
sometimes (usually 10 times trying is enough) when i press alt+tab the desktop freezes totally. only mouse pointer can be moved.




i switched to console with ctrl+alt+f2 and saw that kded5 and kwin are eating 100% of cpu. i attached gdb to them and issued 'bt' command, then 'c' and waited few seconds then 'bt' again and so on. you can find output in files attached.

i had this freeze in vivd alpha1 as well, so it is not very new issue.

Comment 1 Nick Shaforostoff 2015-01-25 02:06:15 UTC

Created attachment 90634 [details]
kwin backtraces

Comment 2 Nick Shaforostoff 2015-01-25 02:07:29 UTC

Created attachment 90635 [details]
kded backtraces

at first the alt+tab freezes only for a second. but if i continue using it, it will freeze totally, and i will have to reboot ;(

Comment 3 Thomas Lübking 2015-01-25 02:09:40 UTC

likely bug #340294 -is that with the default breeze switcher (the vertical bar on the left side)?

Comment 4 Nick Shaforostoff 2015-01-25 02:46:46 UTC

yes

*** This bug has been marked as a duplicate of bug 340294 ***