Application: kwin_x11 (5.10.1)

Qt Version: 5.9.0
Frameworks Version: 5.34.0
Operating System: Linux 4.11.3-1-ARCH x86_64
Distribution: "Arch Linux"

-- Information about the crash:
- What I was doing when the application crashed:

I was browsing with Google Chrome, and wanted to alt-tab away. However, the animation froze for about two seconds right before the window list appeared, then the screen flashed black and the KDE "program crashed" notification appeared.

- Unusual behavior I noticed:

Sometimes there are visual artifacts in the alt-tab window (either a background is missing, some area is blacked out, or all characters are replaced by rectangles). However, this is an older issue, so I doubt it's related.

- Settings

I'm using the Breeze application switcher, and OpenGL 3.1 compositing. vsync is off. However, this also happens with OpenGL 2.0 compositing. I haven't tried with XRender.

I'm using kwin 5.10.1-2, mesa 17.1.1-1, and linux 4.11.3-1 from Arch. I'm using an Intel i5-6600K CPU, and an AMD RX480 graphics card, with the open AMDGPU stack.

The crashing didn't happen under 5.10.1-1, but the visual artifacts did (and usually lasted until I restarted KWin).

However, I doubt the visual artifacts are a hardware issue, since they also happened on my old computer (i5-2500K, R9 270X) with both the fglrx and radeon driver stacks.

The crash can be reproduced sometimes.

-- Backtrace:
Application: Kwin (kwin_x11), signal: Segmentation fault
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f33af4a4840 (LWP 998))]

Thread 11 (Thread 0x7f3371408700 (LWP 1086)):
#0  0x00007f33a80d039d in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007f33ab44cac4 in  () at /usr/lib/libQt5Script.so.5
#2  0x00007f33ab44cb09 in  () at /usr/lib/libQt5Script.so.5
#3  0x00007f33a80ca297 in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007f33aef1325f in clone () at /usr/lib/libc.so.6

Thread 10 (Thread 0x7f337250a700 (LWP 1076)):
#0  0x00007f33a80d039d in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007f337d68a71b in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#2  0x00007f337d68a447 in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#3  0x00007f33a80ca297 in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007f33aef1325f in clone () at /usr/lib/libc.so.6

Thread 9 (Thread 0x7f3372d0b700 (LWP 1075)):
#0  0x00007f33a80d039d in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007f337d68a71b in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#2  0x00007f337d68a447 in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#3  0x00007f33a80ca297 in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007f33aef1325f in clone () at /usr/lib/libc.so.6

Thread 8 (Thread 0x7f337350c700 (LWP 1074)):
#0  0x00007f33a80d039d in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007f337d68a71b in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#2  0x00007f337d68a447 in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#3  0x00007f33a80ca297 in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007f33aef1325f in clone () at /usr/lib/libc.so.6

Thread 7 (Thread 0x7f3373d0d700 (LWP 1073)):
#0  0x00007f33a80d039d in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007f337d68a71b in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#2  0x00007f337d68a447 in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#3  0x00007f33a80ca297 in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007f33aef1325f in clone () at /usr/lib/libc.so.6

Thread 6 (Thread 0x7f337450e700 (LWP 1072)):
#0  0x00007f33a80d039d in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007f337d68a71b in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#2  0x00007f337d68a447 in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#3  0x00007f33a80ca297 in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007f33aef1325f in clone () at /usr/lib/libc.so.6

Thread 5 (Thread 0x7f3374d0f700 (LWP 1071)):
#0  0x00007f33a80d039d in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007f337d68a71b in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#2  0x00007f337d68a447 in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#3  0x00007f33a80ca297 in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007f33aef1325f in clone () at /usr/lib/libc.so.6

Thread 4 (Thread 0x7f338d272700 (LWP 1063)):
#0  0x00007f33aef09396 in ppoll () at /usr/lib/libc.so.6
#1  0x00007f33ac521471 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/libQt5Core.so.5
#2  0x00007f33ac522b5e in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#3  0x00007f33ac4cc21a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007f33ac2ee40a in QThread::exec() () at /usr/lib/libQt5Core.so.5
#5  0x00007f33a6dea645 in  () at /usr/lib/libQt5Qml.so.5
#6  0x00007f33ac2f2cbd in  () at /usr/lib/libQt5Core.so.5
#7  0x00007f33a80ca297 in start_thread () at /usr/lib/libpthread.so.0
#8  0x00007f33aef1325f in clone () at /usr/lib/libc.so.6

Thread 3 (Thread 0x7f338f65d700 (LWP 1012)):
#0  0x00007f33aef09396 in ppoll () at /usr/lib/libc.so.6
#1  0x00007f33ac521471 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/libQt5Core.so.5
#2  0x00007f33ac522b5e in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#3  0x00007f33ac4cc21a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007f33ac2ee40a in QThread::exec() () at /usr/lib/libQt5Core.so.5
#5  0x00007f33a5f9ad45 in  () at /usr/lib/libQt5DBus.so.5
#6  0x00007f33ac2f2cbd in  () at /usr/lib/libQt5Core.so.5
#7  0x00007f33a80ca297 in start_thread () at /usr/lib/libpthread.so.0
#8  0x00007f33aef1325f in clone () at /usr/lib/libc.so.6

Thread 2 (Thread 0x7f3395813700 (LWP 1009)):
#0  0x00007f33aef092bd in poll () at /usr/lib/libc.so.6
#1  0x00007f33adfef8e0 in  () at /usr/lib/libxcb.so.1
#2  0x00007f33adff1679 in xcb_wait_for_event () at /usr/lib/libxcb.so.1
#3  0x00007f33968eed49 in  () at /usr/lib/libQt5XcbQpa.so.5
#4  0x00007f33ac2f2cbd in  () at /usr/lib/libQt5Core.so.5
#5  0x00007f33a80ca297 in start_thread () at /usr/lib/libpthread.so.0
#6  0x00007f33aef1325f in clone () at /usr/lib/libc.so.6

Thread 1 (Thread 0x7f33af4a4840 (LWP 998)):
[KCrash Handler]
#6  0x00007f337da4b71e in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#7  0x00007f337d7b9f25 in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#8  0x00007f337d595940 in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#9  0x00007f337d555b30 in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#10 0x00007f337d555fb9 in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#11 0x00007f33a749d27f in QSGBatchRenderer::Renderer::renderMergedBatch(QSGBatchRenderer::Batch const*) () at /usr/lib/libQt5Quick.so.5
#12 0x00007f33a749e4c5 in QSGBatchRenderer::Renderer::renderBatches() () at /usr/lib/libQt5Quick.so.5
#13 0x00007f33a74a3c24 in QSGBatchRenderer::Renderer::render() () at /usr/lib/libQt5Quick.so.5
#14 0x00007f33a74945cd in QSGRenderer::renderScene(QSGBindable const&) () at /usr/lib/libQt5Quick.so.5
#15 0x00007f33a7494a8b in QSGRenderer::renderScene(unsigned int) () at /usr/lib/libQt5Quick.so.5
#16 0x00007f33a74ced40 in QSGDefaultRenderContext::renderNextFrame(QSGRenderer*, unsigned int) () at /usr/lib/libQt5Quick.so.5
#17 0x00007f33a752b868 in QQuickWindowPrivate::renderSceneGraph(QSize const&) () at /usr/lib/libQt5Quick.so.5
#18 0x00007f33a74c1139 in  () at /usr/lib/libQt5Quick.so.5
#19 0x00007f33a7535ad6 in QQuickWindow::event(QEvent*) () at /usr/lib/libQt5Quick.so.5
#20 0x00007f32cf6947ab in PlasmaQuick::Dialog::event(QEvent*) () at /usr/lib/libKF5PlasmaQuick.so.5
#21 0x00007f33ad1f846c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5
#22 0x00007f33ad1ffcf4 in QApplication::notify(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5
#23 0x00007f33ac4cdb98 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib/libQt5Core.so.5
#24 0x00007f33aca42751 in QWindowPrivate::deliverUpdateRequest() () at /usr/lib/libQt5Gui.so.5
#25 0x00007f33aca42c69 in QWindow::event(QEvent*) () at /usr/lib/libQt5Gui.so.5
#26 0x00007f33a7535a75 in QQuickWindow::event(QEvent*) () at /usr/lib/libQt5Quick.so.5
#27 0x00007f32cf6947ab in PlasmaQuick::Dialog::event(QEvent*) () at /usr/lib/libKF5PlasmaQuick.so.5
#28 0x00007f33ad1f846c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5
#29 0x00007f33ad1ffcf4 in QApplication::notify(QObject*, QEvent*) () at /usr/lib/libQt5Widgets.so.5
#30 0x00007f33ac4cdb98 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib/libQt5Core.so.5
#31 0x00007f33ac524bae in QTimerInfoList::activateTimers() () at /usr/lib/libQt5Core.so.5
#32 0x00007f33ac522dc2 in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#33 0x00007f33969515bd in  () at /usr/lib/libQt5XcbQpa.so.5
#34 0x00007f33ac4cc21a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#35 0x00007f33ac4d4a74 in QCoreApplication::exec() () at /usr/lib/libQt5Core.so.5
#36 0x00007f33af1d3fd5 in kdemain () at /usr/lib/libkdeinit5_kwin_x11.so
#37 0x00007f33aee4643a in __libc_start_main () at /usr/lib/libc.so.6
#38 0x000000000040069a in _start ()

Reported using DrKonqi