Application: kwin_x11 (5.16.4) Qt Version: 5.12.2 Frameworks Version: 5.61.0 Operating System: Linux 5.0.0-25-generic x86_64 Distribution: Ubuntu 19.04 -- Information about the crash: 1. Connected docking station with 2 external displays 2. Powered on 3. Logged in. 4. Segfault happend I am using DisplayLink 5.2.14. -- Backtrace: Application: KWin (kwin_x11), signal: Segmentation fault Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". [Current thread is 1 (Thread 0x7f23a7056880 (LWP 2273))] Thread 2 (Thread 0x7f23a5553700 (LWP 2330)): #0 0x00007f23aef96826 in __GI_ppoll (fds=0x7f239800b498, nfds=1, timeout=<optimized out>, sigmask=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39 #1 0x00007f23adb01041 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /lib/x86_64-linux-gnu/libQt5Core.so.5 #2 0x00007f23adb024b9 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib/x86_64-linux-gnu/libQt5Core.so.5 #3 0x00007f23adab05bb in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib/x86_64-linux-gnu/libQt5Core.so.5 #4 0x00007f23ad8fb2c6 in QThread::exec() () at /lib/x86_64-linux-gnu/libQt5Core.so.5 #5 0x00007f23abcb5565 in () at /lib/x86_64-linux-gnu/libQt5DBus.so.5 #6 0x00007f23ad8fc612 in () at /lib/x86_64-linux-gnu/libQt5Core.so.5 #7 0x00007f23aca9d182 in start_thread (arg=<optimized out>) at pthread_create.c:486 #8 0x00007f23aefa2b1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 Thread 1 (Thread 0x7f23a7056880 (LWP 2273)): [KCrash Handler] #5 0x00007f23aebf60b7 in () at /lib/x86_64-linux-gnu/libkwin.so.5 #6 0x00007f23aec030b8 in KWin::Workspace::init() () at /lib/x86_64-linux-gnu/libkwin.so.5 #7 0x00007f23aec038de in KWin::Workspace::Workspace(QString const&) () at /lib/x86_64-linux-gnu/libkwin.so.5 #8 0x00007f23aec774e4 in KWin::Application::createWorkspace() () at /lib/x86_64-linux-gnu/libkwin.so.5 #9 0x00007f23af077c78 in () at /lib/x86_64-linux-gnu/libkdeinit5_kwin_x11.so #10 0x00007f23adadb563 in QMetaObject::activate(QObject*, int, int, void**) () at /lib/x86_64-linux-gnu/libQt5Core.so.5 #11 0x00007f23af078126 in () at /lib/x86_64-linux-gnu/libkdeinit5_kwin_x11.so #12 0x00007f23adadb563 in QMetaObject::activate(QObject*, int, int, void**) () at /lib/x86_64-linux-gnu/libQt5Core.so.5 #13 0x00007f23ae9a8da3 in () at /lib/x86_64-linux-gnu/libKF5WindowSystem.so.5 #14 0x00007f23ae9a9559 in KSelectionOwner::filterEvent(void*) () at /lib/x86_64-linux-gnu/libKF5WindowSystem.so.5 #15 0x00007f23adaaf44f in QAbstractEventDispatcher::filterNativeEvent(QByteArray const&, void*, long*) () at /lib/x86_64-linux-gnu/libQt5Core.so.5 #16 0x00007f23a6928580 in QXcbConnection::handleXcbEvent(xcb_generic_event_t*) () at /lib/x86_64-linux-gnu/libQt5XcbQpa.so.5 #17 0x00007f23a692950d in QXcbConnection::processXcbEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib/x86_64-linux-gnu/libQt5XcbQpa.so.5 #18 0x00007f23a6953a1c in () at /lib/x86_64-linux-gnu/libQt5XcbQpa.so.5 #19 0x00007f23adab05bb in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib/x86_64-linux-gnu/libQt5Core.so.5 #20 0x00007f23adab85e2 in QCoreApplication::exec() () at /lib/x86_64-linux-gnu/libQt5Core.so.5 #21 0x00007f23af079df8 in kdemain () at /lib/x86_64-linux-gnu/libkdeinit5_kwin_x11.so #22 0x00007f23aeeabb6b in __libc_start_main (main=0x556c3fec2050, argc=3, argv=0x7ffd9bc1d388, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffd9bc1d378) at ../csu/libc-start.c:308 #23 0x0000556c3fec208a in _start () [Inferior 1 (process 2273) detached] Reported using DrKonqi
The backtrace lacks debug symbols. Can you please install debug packages and submit a new backtrace?
Tried to reproduce with debug symbols installed. kwin_x11 didn't crash this time but kwin_x11 and plasmashell consume 100% CPU
Interesting... Can you please still post kwins backtrace?
Relevant wiki page: https://community.kde.org/KWin/Debugging
Here an udpate: I am using a Thinkpad T580 with a ThinkPad Hybrid USB-C with USB-A dock which uses DisplayLink. The problem I encountered yesterday was when I attached 2 external DVI displays. I believe the problem might have to do with the fact that I didn't have the dock connected to the Thinkpad at power on and/or DisplayLinkManager was not running when logging in. Later yesterday, support replaced those old DVI displays with two new ones using HDMI. Now, I can no longer reproduce the problem...
Created attachment 122399 [details] kwin_x11 backtrace
ok, waiting a bit longer I see kwin_x11 using 100% cpu even with 2 HDMI displays attached. I am using deb http://ppa.launchpad.net/kubuntu-ppa/backports/ubuntu disco main/debug but I wasn't able to get all debug symbols, eg: E: Unable to locate package libqt5gui5-dbg E: Unable to locate package libqt5gui5-dbgsym Where can I get these?
I'm sorry but I don't use Ubuntu. I suggest to ask that question on support forum of your distro.
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!
On Kubuntu, currently the debug packages don't match the installed packages. Hence I was not able to get annotated backtraces. In the meantime I switched my docking station and also changed attached displays. I didn't see the reported issue anymore. I suggest to close this bug report.