Summary I started the System Monitor from the command line as background task and then quit konsole as I saw how much output system monitor made. I had the program running for about 5-15 minutes. Suddenly the system got slower and slower, and then froze completely. I had to terminate the computer hard by turning power off. The only other window open was a web browser with 2 tabs. Steps to reproduce 1) open konsole 2) plasma-systemmonitor & 3) quit konsole after a minute or so 4) wait 5-15 minutes Observed Result The system has frozen (memory or cpu overload) EXPECTED RESULT System Monitor should not cause the system to freeze. Frankly, I doubt whether it is a good idea to ship software with such risky bugs to end users. A task manager should be fast and reliable. The System Monitor is quite the contrary. (I uninstalled it now.) Software / Operating System versions Operating System: KDE neon 5.22 KDE Plasma Version: 5.22.3 KDE Frameworks Version: 5.84.0 Qt Version: 5.15.3 Kernel Version: 5.8.0-59-generic (64-bit) Graphics Platform: Wayland Processors: 4 × Intel® Core™ i5-3570K CPU @ 3.40GHz Memory: 7.2 GiB of RAM Graphics Processor: Mesa DRI Intel® HD Graphics 4000
This is not reproducible. I have had system-monitor for hours. We need some logs to prove what's actually at fault. If you can provide more information it would be appreciated, but this report is not actionable at present especially as you have uininstalled it.
> This is not reproducible. I have had system-monitor for hours. Did you also do this with the same program version as I have, and did you follow the steps to reproduce? I think it is important to start system monitor in konsole. I guess the freeze might have had something to do with the exceptionally big command-line output. What about trying it with current KDE Neon User? I would expect the issue to be reproducable there. > this report is not actionable at present especially as you have uininstalled it. I do not wish to experience freezing systems any futher, nor do I maintain the System Monitor. It is the developer's task to debug and fix such conditions, not mine.
> We need some logs to prove what's actually at fault. Which logs / files do you need?
> Manuel Geißer 2021-07-16 10:07:12 UTC > David Edmundson 2021-07-16 10:17:08 UTC From looking at when you responded, you barely had enough time to try and reproduce, so please don't claim yet that it is not reproducible.
Not sure whether this matters, but when I had the system monitor running it lately did not display the graphs, animations, etc. I'd uploaded a screenshot to Bug 439478 (https://bugsfiles.kde.org/attachment.cgi?id=140110). This was not the case with previous versions of System Monitor.
The not displaying graphs is interesting. Can you run the following: wget 'https://invent.kde.org/frameworks/kquickcharts/-/raw/master/examples/snippets/linechart.qml' qmlscene linechart.qml and confirm if you see graphs, and if you have any CPU spikes
Invoking qmlscene fails with the following error: qmlscene: could not find a Qt installation of ''
Apparently this error message just meant I did not have qmlscene installed. After installing the qmlscene package, I do see the graphs and there are no cpu spikes.
I reinstalled the system monitor, but still don't see any graphs. Also, the program terminates with a segfault on exit... Here's a backtrace (probably useless due to missing symbols, but I can redo it): ``` Thread 8 "QSGRenderThread" received signal SIGSEGV, Segmentation fault. [Switching to Thread 0x7fffe1dec700 (LWP 7787)] 0x00007fffe981f41f in ?? () from /lib/x86_64-linux-gnu/libEGL_mesa.so.0 (gdb) bt full #0 0x00007fffe981f41f in ?? () from /lib/x86_64-linux-gnu/libEGL_mesa.so.0 No symbol table info available. #1 0x00007fffe981f828 in ?? () from /lib/x86_64-linux-gnu/libEGL_mesa.so.0 No symbol table info available. #2 0x00007fffe8836a4c in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so No symbol table info available. #3 0x00007fffe88371d9 in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so No symbol table info available. #4 0x00007fffe8833697 in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so No symbol table info available. #5 0x00007ffff5cc5b0a in QSGBatchRenderer::Renderer::renderBatches() () from /lib/x86_64-linux-gnu/libQt5Quick.so.5 No symbol table info available. #6 0x00007ffff5cc622a in QSGBatchRenderer::Renderer::render() () from /lib/x86_64-linux-gnu/libQt5Quick.so.5 No symbol table info available. #7 0x00007ffff5ca9de4 in QSGRenderer::renderScene(QSGBindable const&) () from /lib/x86_64-linux-gnu/libQt5Quick.so.5 No symbol table info available. #8 0x00007ffff5caa2b3 in QSGRenderer::renderScene(unsigned int) () from /lib/x86_64-linux-gnu/libQt5Quick.so.5 No symbol table info available. #9 0x00007ffff5d18fa7 in QSGDefaultRenderContext::renderNextFrame(QSGRenderer*, unsigned int) () from /lib/x86_64-linux-gnu/libQt5Quick.so.5 No symbol table info available. #10 0x00007ffff5d868f9 in QQuickWindowPrivate::renderSceneGraph(QSize const&, QSize const&) () from /lib/x86_64-linux-gnu/libQt5Quick.so.5 No symbol table info available. #11 0x00007ffff5d26ae9 in ?? () from /lib/x86_64-linux-gnu/libQt5Quick.so.5 No symbol table info available. #12 0x00007ffff5d2af77 in ?? () from /lib/x86_64-linux-gnu/libQt5Quick.so.5 No symbol table info available. #13 0x00007ffff653adbc in ?? () from /lib/x86_64-linux-gnu/libQt5Core.so.5 No symbol table info available. #14 0x00007ffff56fc609 in start_thread (arg=<optimized out>) at pthread_create.c:477 ret = <optimized out> pd = <optimized out> unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140736982861568, 2329164821534385652, 140737488343166, 140737488343167, 140737488343344, 140736982859072, -2329178297014639116, -2329150666724432396}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = { prev = 0x0, cleanup = 0x0, canceltype = 0}}} not_first_call = 0 #15 0x00007ffff61bb293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 ```
Now I installed some symbols (namely plasma-systemmonitor-dbgsym and qml-module-qtqml-dbgsym), and a segfault is not reproducable anymore after installing the latter. Really strange.
Moving from critical as we have no other user affected.
I think this incident probably was the same cause as Bug 433071. Since I am using LIBGL_ALWAYS_SOFTWARE=1, I haven't had any performance problems with plasma-systemmonitor, and the graphs now also show up again. I recently filed a Qt Bug about my graphics issues in QtQuick apps with OpenGL.