I am using Kubuntu 15.10 with kwin 5.4.3. I am not sure how to replicate this.. it just happens from time to time. Here are some additional information (found the commands to get them on https://bugs.kde.org/show_bug.cgi?id=340294 but I don't really know what these are) $ grep -i glamor /var/log/Xorg.0.log` > glamor_kwin.txt $ qdbus org.kde.KWin /KWin supportInformation > qdbus_kwin.txt [press Ctrl+Alt+F1] [login] # this will allow you to attach gdb to kwin $ echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope # run gdb, log to "kwin.gdb" $ gdb --pid `pidof kwin` 2>&1 | tee gdb_kwin.txt # you're not in the gdb prompt ">" > bt [enter, enter, enter, ... until there's no more output] > detach > quit $ exit [press Ctrl+Alt+F7] Reproducible: Didn't try Steps to Reproduce: 1. Login 2. Do stuff 3. Flip a coin: sometimes the problem happens
Created attachment 95547 [details] See bug report (glamor)
Created attachment 95548 [details] See bug report (qbus)
(In reply to Marco T. from comment #1) > Created attachment 95547 [details] > See bug report (glamor)
Created attachment 95549 [details] See bug report (gdb)
The stacktrace shows a dormant thread. If this was dumped while the process was hich loading, the load will be in another thread. The stacktrace will only be of value if the system is loaded at that time. In case, switch the threads in gdb: > thread 2 > bt > thread 3 > bt > thread 4 > bt ... until you get "Thread ID <n> not known." Wild guess: is the CPU load related to switching the virtual terminal?
Created attachment 95553 [details] gdb for all threads
Sorry about that; it's exactly what I meant by "I don't really know what these are". I hope the new file helps.
just a hint for future: "t a a bt" gives one all thread backtraces.
Threads 2 & 3 may lock each other, unfortunately Qt has no debug symbols (you typically need to install the *-dev packages on debian based distros) Since it's QtQuick and you're not using an aurorae deco: can you relate this to some circumstances (you referenced a bug in the tabbox QML => alt+tab related?)
On top of my head, I cannot come up with any explanation. Tomorrow I will do a few of the usual things and see which one triggers the problem. What -dev packages should I install to make the reports more useful?
qt5-quick1 qt5-quickcontrols 5.5.1-3 qt5-script They might have slightly different names, though (no ubuntu here)
and you need the -dbg not -dev packages.
Hello Nazgul, it seems you were pending a better backtrace. Is this issue still reproducible for you with newer Plasma? If it's still somehow reproducible you can follow the instructions of the Kubuntu wiki to provide a better backtrace: https://wiki.kubuntu.org/Debug%20Symbol%20Packages Although depending on the package manager integration gdb itself might provide you with the correct command to install the missing debug packages.
Dear Bug Submitter, This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information as soon as possible and set the bug status as REPORTED. Due to regular bug tracker maintenance, if the bug is still in NEEDSINFO status with no change in 30 days the bug will be closed as RESOLVED > WORKSFORME due to lack of needed information. For more information about our bug triaging procedures please read the wiki located here: https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging If you have already provided the requested information, please mark the bug as REPORTED so that the KDE team knows that the bug is ready to be confirmed. Thank you for helping us make KDE software even better for everyone!
This bug has been in NEEDSINFO status with no change for at least 30 days. The bug is now closed as RESOLVED > WORKSFORME due to lack of needed information. For more information about our bug triaging procedures please read the wiki located here: https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging Thank you for helping us make KDE software even better for everyone!