juus wrote:Hi,

I've been able to avoid lockups for almost two months now (my original post is under Juus Oct. 24). Summary is below but the TLDR: it only happens (to me) when a DRM enabled browser is open. I am running 64 bit Kubuntu 20.04.
....

I have seen this with chrome and the proprietary nvidia driver when playing youtube videos. But only on certain combinations of chrome, nvidia driver, and kernel. If I disable GPU acceleration in chrome the problem goes away. I'm on OpenSUSE Tumbleweed the problem usually resolves itself or reappears periodically when one of the kernel, chrome, or the video driver roll over to a new version (which is quite often). At the moment all three have been stable with no crashes for several months including across updates. I'm currently on Tumbleweed 20211227, kernel 5.15.8-1, nvidia 470.86-46, chrome-stable-96.0.4664.

So the key for my circumstances is to identify a stable combo of kernel, GPU, and browser (or to disable GPU acceleration in the browser).

These kinds of issues may also be caused by faulty hardware: RAM, motherboard settings, thermals, so it could be worth running some tests with tools like stress-ng or some GPU benchmarks such as Unigine_Valley or Unigine_Heaven_Benchmark.

BTW, if you're logging in via sddm, before logging in after a crash, it might be worth logging in on a console and preserving/checking $HOME/.local/share/sddm/xorg-session.log in case anything useful made it into the session log.

<sigh> My earlier suspicion that it was related to DRM enabled browsers is now debunked. I've had two more lockups while using Falkon too.
The top spot in htop when it froze was being used by KWin.

This is a very depressing problem! I now am saving everything immediately, particularly frustrating when one is a programmer hopping all over units...did I forget to save???

Is it not possible to develop a tool that we can use to help debug this? It has to have constant file update because the computer is not accessible after the freeze in any way. Normal logs have been useless. I've already mentioned one can not even ssh into the frozen computer. Help.

xorg session log was 0 bytes.

juus wrote:<sigh> My earlier suspicion that it was related to DRM enabled browsers is now debunked. I've had two more lockups while using Falkon too.
The top spot in htop when it froze was being used by KWin.

This is a very depressing problem! I now am saving everything immediately, particularly frustrating when one is a programmer hopping all over units...did I forget to save???

Is it not possible to develop a tool that we can use to help debug this? It has to have constant file update because the computer is not accessible after the freeze in any way. Normal logs have been useless. I've already mentioned one can not even ssh into the frozen computer. Help.

xorg session log was 0 bytes.

Is that with falkon –disable-gpu? In my experience it's not DRM, but GPU acceleration (particularly GPU video decoding for youtube) that can cause issues.

If a driver pulls down the whole operating system there is not much you can do to obtain info, it may be that OS buffers or disk buffers don't get flushed, so logs are incomplete. However, I do sometimes find something in the journalctl, coredumpctl, or ~/.local/share/sddm/xorg-session.log. You might tail logs, dmesg, etc, ~/.local/share/sddm/xorg-session.log to a remote machine, but they too may not be flushed if the OS is totally frozen.

In such circumstances, I generally revert to a known working combo of kernel, GPU driver, and browser.

It makes me a bit scared to say it, because saying it could make the Universe shudder and renege, but...

Since I installed Kubuntu 22.04, that is for 2 and half months, I've had no freezes.

I'm on the latest Arch and kernel version and Plasma is randomly freezing for me as well.
I randomly can't click anything on the desktop or the taskbar, only the programs that I already have running at the time of the freeze keep working.
It then fixes itself after some minutes and returns to work normally tho, idk what the problem is, but it's very annoying...
I'm currently using the nvidia-dkms drivers since zen and linux-rt refuse to start with the normal ones, but it happened before switching kernel as well...

I've run into similar issues. With KDE crashes before, I was always able to switch TTY, kill plasmashell, then switch back and use quick runner (alt+space, not sure what it's actually called) to restart plasmashell. Ever since encountering this issue though, it is a huge pain. I typically have many windows across many desktops open, and the do not restore nicely after a reboot. I've found that when this happens, I am able to switch TTY, kill plasmashell, then switch back. I then need to wait between 10s-10mins before the quick runner is "available" again, and from there i can restart plasmashell. Very frustrating.

I can consistently reproduce this issue on my machine though, everytime, which I believe is the first time anyones been able to do that. When I play a video with mpv 0.35.0, everything is fine. Until I fullscreen the video. Plasmashell utterly and completely locks up. The amount of time it take tailing journalctl, I see the logs just absolutely flooded with
```
Jan 27 22:31:17 <device name> xembedsniproxy[1018]: Container window visible, stack below
```
In fact, `sudo journalctl | grep xembedsniproxy | wc -l` tops just over 8 million. I believe the amount of time it takes to recover (waiting period for quick runner) is proportional to how long the full screen mpv state is in.

Is anyone able to provide the next steps to getting this fixed? I am willing to help here, I enjoy KDE but if this remains unfixed I will have to switch.

Some misc details that might help someone draw some correlations here: GTX 1070, 2 displays

Googled around and found this bug: https://bugs.kde.org/show_bug.cgi?id=425271

The workarounds mentioned here worked for me. Very frustrating

Same problem on kubuntu 22.10. First ever, many total freezes. Hard reboot is the only option.

I am having the same issue on Kubuntu 20.10. Random freeze, usually the only apps i have open are spotify, visual studio code. plasma widgets running are clipboard viewer, weather widget. Hope someone can figure this one out.

Operating System: Kubuntu 22.10
KDE Plasma Version: 5.25.5
KDE Frameworks Version: 5.98.0
Qt Version: 5.15.6
Kernel Version: 5.19.0-29-generic (64-bit)
Graphics Platform: X11
Processors: 8 × 11th Gen Intel® Core™ i7-1165G7 @ 2.80GHz
Memory: 31.1 GiB of RAM
Graphics Processor: Mesa Intel® Xe Graphics
Manufacturer: Dell Inc.
Product Name: Inspiron 15 3511

Just happened again. I think it has something todo with the notifications as i have a unrendered notification every time it freezes. I turned off notifications to see if this fixes the problem. Will report back if that solves it.

stratemeyerjw wrote:Just happened again. I think it has something todo with the notifications as i have a unrendered notification every time it freezes. I turned off notifications to see if this fixes the problem. Will report back if that solves it.

That seemed todo the trick for me. No freezing since I last posted.
I also removed all broken symbolic links. by -

Code: Select all

 sudo apt-get install symlinks && cd ~ && symlinks -r . -d

This helped with the plasma menu and searching. the system seems much more responsive.