When logging off, ksmserver5 will take up 100 % CPU after quitting of most of the apps. Then the session hangs (for any reasonable timespan) and I have to kill ksmserver5.

Reproducible: Sometimes

Steps to Reproduce:
I found no reliable way to reproduce, but for short session it seems to be okay. Might depend on anything, programs, suspends, I am sorry but I don't know. :-/



Attaching to the process with gdb gave that backtrace
Using host libthread_db library "/lib64/libthread_db.so.1".
0x00007fdb387b7e15 in _nv014tls () from /usr/lib64/libnvidia-tls.so.355.11
#0  0x00007fdb387b7e15 in _nv014tls () from /usr/lib64/libnvidia-tls.so.355.11
#1  0x00007fdb39ffac4d in ?? () from /usr/lib64/opengl/nvidia/lib/libGL.so.1
#2  0x00007fdb39ffb018 in ?? () from /usr/lib64/opengl/nvidia/lib/libGL.so.1
#3  0x00007fdb39fa07c2 in ?? () from /usr/lib64/opengl/nvidia/lib/libGL.so.1
#4  0x00007fdb39fcd29e in ?? () from /usr/lib64/opengl/nvidia/lib/libGL.so.1
#5  0x00007fdb39fd1be8 in ?? () from /usr/lib64/opengl/nvidia/lib/libGL.so.1
#6  0x00007fdb39fc44e3 in glXCreateContextAttribsARB () from /usr/lib64/opengl/nvidia/lib/libGL.so.1
#7  0x00007fdb31436874 in QGLXContext::init (this=0x1a9b510, screen=0x19bc8c0, share=<optimized out>) at qglxintegration.cpp:264
#8  0x00007fdb3143473b in QXcbGlxIntegration::createPlatformOpenGLContext (this=<optimized out>, context=0x7fff0da24ed0) at qxcbglxintegration.cpp:187
#9  0x00007fdb31351db1 in QXcbIntegration::createPlatformOpenGLContext (this=<optimized out>, context=0x7fff0da24ed0) at qxcbintegration.cpp:222
#10 0x00007fdb3bb3699d in QOpenGLContext::create (this=this@entry=0x7fff0da24ed0) at kernel/qopenglcontext.cpp:594
#11 0x00007fdb3143735a in QGLXContext::queryDummyContext () at qglxintegration.cpp:657
#12 0x00007fdb31437501 in QGLXContext::supportsThreading () at qglxintegration.cpp:688
#13 0x00007fdb32e599db in QSGRenderLoop::instance() () from /usr/lib64/libQt5Quick.so.5
#14 0x00007fdb32e8c63d in QQuickWindowPrivate::init(QQuickWindow*, QQuickRenderControl*) () from /usr/lib64/libQt5Quick.so.5
#15 0x00007fdb32f3afbd in QQuickView::QQuickView(QWindow*) () from /usr/lib64/libQt5Quick.so.5
#16 0x00007fdb3283eccc in ?? () from /usr/lib64/libkdeinit5_ksmserver.so
#17 0x00007fdb32840852 in ?? () from /usr/lib64/libkdeinit5_ksmserver.so
#18 0x00007fdb3284e4e6 in ?? () from /usr/lib64/libkdeinit5_ksmserver.so
#19 0x00007fdb32853c2f in ?? () from /usr/lib64/libkdeinit5_ksmserver.so
#20 0x00007fdb32853e73 in ?? () from /usr/lib64/libkdeinit5_ksmserver.so
#21 0x00007fdb34178f1c in QDBusConnectionPrivate::deliverCall (this=this@entry=0x1a6d9d0, object=object@entry=0x1ac4380, msg=..., metaTypes=..., slotIdx=11) at qdbusintegrator.cpp:979
#22 0x00007fdb3417d628 in QDBusConnectionPrivate::activateCall (this=this@entry=0x1a6d9d0, object=0x1ac4380, flags=flags@entry=273, msg=...) at qdbusintegrator.cpp:885
#23 0x00007fdb3417e0d3 in QDBusConnectionPrivate::activateObject (this=0x1a6d9d0, node=..., msg=..., pathStartPos=<optimized out>) at qdbusintegrator.cpp:1462
#24 0x00007fdb3417fd9e in QDBusActivateObjectEvent::placeMetaCall (this=0x1b36710) at qdbusintegrator.cpp:1580
#25 0x00007fdb3b7dad1a in QObject::event (this=0x1a8c950, e=<optimized out>) at kernel/qobject.cpp:1246
#26 0x00007fdb3a98db7c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib64/libQt5Widgets.so.5
#27 0x00007fdb3a98e230 in QApplication::notify(QObject*, QEvent*) () from /usr/lib64/libQt5Widgets.so.5
#28 0x00007fdb3b7a9d3b in QCoreApplication::notifyInternal (this=0x1940970, receiver=0x1a8c950, event=event@entry=0x1b36710) at kernel/qcoreapplication.cpp:965
#29 0x00007fdb3b7ac0b3 in QCoreApplication::sendEvent (event=0x1b36710, receiver=<optimized out>) at kernel/qcoreapplication.h:224
#30 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x18bb0b0) at kernel/qcoreapplication.cpp:1593
#31 0x00007fdb3b7ac678 in QCoreApplication::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1451
#32 0x00007fdb3b802f73 in postEventSourceDispatch (s=0x1a50a50) at kernel/qeventdispatcher_glib.cpp:271
#33 0x00007fdb38ee392d in g_main_context_dispatch () from /usr/lib64/libglib-2.0.so.0
#34 0x00007fdb38f4c058 in ?? () from /usr/lib64/libglib-2.0.so.0
#35 0x00007fdb38ee4dcc in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#36 0x00007fdb3b803367 in QEventDispatcherGlib::processEvents (this=0x1a5b600, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#37 0x00007fdb3b7a7532 in QEventLoop::exec (this=this@entry=0x7fff0da25c10, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#38 0x00007fdb3b7af62c in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1229
#39 0x00007fdb32835c49 in kdemain () from /usr/lib64/libkdeinit5_ksmserver.so
#40 0x0000000000408410 in ?? ()
#41 0x0000000000409c49 in ?? ()
#42 0x000000000040a1f0 in ?? ()
#43 0x0000000000404f14 in main ()

I produced 21 identical backtraces and checked with sysprof, which shows that the system is busy in _nv014tls.