Hey KDE Users,

my plasma taskbar + krunner freeze regularly and I would like to determine the root cause.
I suspect that it might have sth to do with my sound driver (I use sof-firmware).

How can can I see which processes actually froze? Is there a log file somewhere where I can see what happened.
Currently I have to restart my plasma shell every 30 minutes or so, which is really annoying.

Thank you for your help.

Hi,
you can type
dmesg (or sudo dmesg if needed)
to see kernel messages. Freezes tend to be related to graphics issues, sou you could look for errors concerning graphics.

I doubt that it's a kde app that freezes, it'll rather be a driver issue (but ymmv).
Did those issues start after a kernel update?
Regards
Andreas

Yes, the trouble started after a kernel update. And I know that they had big changes concerning the sound driver for my machine. Switching to a new driver based on sof-firmware.

As to dmesg/journalctl: I have already looked at this. The only suspicious messages there are
sof-audio-pci 0000:00:1f.3: error: no reply expected, received 0x0
wpa_supplicant[587]: nl80211: kernel reports: Attribute failed policy validation
wpa_supplicant[587]: Failed to create interface p2p-dev-wlp0s20f3: -22 (Invalid argument)
wpa_supplicant[587]: nl80211: Failed to create a P2P Device interface p2p-dev-wlp0s20f3

The problem is that all programs and even sound work flawlessly nevertheless. But it seems as if plasma freezes because of this issue. I can simply restart the plasmashell using an already open terminal and the computer continues to work fine.

So it seems to me, that some driver issue/response or whatever triggers a bug in plasma and makes it freeze. And I currently don't know a way to find out what happens and how to even provide a meaningful bugreport.

Some more information about the exact Plasma version and distribution as well as RAM and SWAP settings could be helpful...

I'm running the latest Plasma Version on Arch Linux 5.18.5 (16 GB of RAM + 20 GB swap partition)

But I'm pretty sure, we cannot debug this with this information alone. If there aren't any log files that are written, or debug settings that can be enabled, I doubt we can trace this one down.

Thanks in advance nevertheless.

Switch back to a lts kernel where the problem does not occur. I have a netbook where I have to use 4.19 kernel!

As long as you do not have any hardware that needs a newer kernel, I see no disadvantage in using an older kernel as long as you get security updates for it.

It's correct that it works in 4.19 but the current LTS kernel version is 5.4 where it doesn't work.

So yes, there are workarounds. But shouldn't we aim at figuring out, why plasma is freezing nevertheless. There is a bug and we should fix it instead of working around it. I am pretty sure that the same bug may cause trouble for other people in other circumstances.

I am willing to track this bug down, if anyone can tell me a way to narrow the problem down.

Then you might want to use

journalctl -f

and keep it running in a terminal window until a freeze occurs. I have understood that your pc does not crash completely, so you should see something in the journal.

Then you can write a bug report (I still do not think that this is a kde issue, rather a kernel driver issue).

Read up on journalctl here:

https://www.loggly.com/ultimate-guide/using-journalctl/

Regards,

Andreas
Edit: I see that this is a commercial site I linked to. You will find other resources concerning journalctl .

I already looked at dmesg and journalctl outputs and there wasn't anything specific besides the errors, that I have already posted.

If nobody has an idea, I will have to permanently switch to Gnome, which worked flawlessly so far.

The problem is that an actual crash (access violation) would show up in the logs.

If you really want to track this down and are quite confident that it is a plasma issue, you can try to debug this.

Read here

https://community.kde.org/Guidelines_an ... sh_reports

on how to do it. But as (as you say) it is not really a crash, rather a freeze, I am not sure on how to do that.

I have being struggling with this issue now for more than 2 years. I changed all the hardware already to test if this freezing of the system is anyhow hardware related (changed power supply, video board, ram, motherboard, everything) and it keeps freezing. I'm abandoning KDE Plasma that I love for now because I simply can't work. Need to restart the computer everytime the system freezes completely and makes my keyboard impossible to use, mouse freezes, nothing works except to hit the reset button. Please, solve this, I have almost tears in my eyes because I need to work and with this terrible freezing problem I can't do it anymore with KDE plasma (by the way, yes, I tried almost every single distro with KDE plasma and problem persists).

If the crashes are just KDE/X locking up, and you have an ssh daemon running, you could try to ssh into the crashed system from another computer.

bioduds wrote:I have being struggling with this issue now for more than 2 years. I changed all the hardware already to test if this freezing of the system is anyhow hardware related (changed power supply, video board, ram, motherboard, everything) and it keeps freezing....

How about a bit more precision in your question:
your exact Plasma version and distribution?
X or Wayland?
Native installation or VM and if the latter, which?
What did you change from the default installation?
What 3rd-party software are you running that could cause a problem?

A look at the system logs (accessible via Ksyslog) should also give a clue. All those log files are also accessible without a GUI, depending on the distribution those should usually be located in /var/log

Hi, I've been following this issue because its happening to me as well, completely random, logs not informative.

I dual boot Kubuntu 20.04 and Ubuntu Studio 21.04 or .10. Kubuntu froze again last night after about 5 or 6 days without a freeze. Recently Ubuntu studio switched to plasma, Ub. studio has also frozen on me.

I have tried alt + Sysreq + B, keyboard contines to be useless. I am positive that the alt+sysreq is active, I've tested it when the machine was not frozen.

I do have a bit more information which I hope will help. By happenstance I logged into my Kubuntu machine via ssh from my local home network server machine, all was well. The latest freeze was a few minutes after this, I tried ssh again and it failed with a similar message as when you give ssh a bad URL.

So it appears to be a complete kernel freeze? There is no discernible pattern here as to when or why the computer freezes.

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.

Summary: I started keeping htop open all day long and on two occasions when it froze the top 8 or so processes were always Firefox browser. Firefox was always the second or third appl. I started each day, and it was open all day.

So I resolved to stop using firefox and searched for other browsers settling on "pale moon" first. Nice, but it has some pages it can't read. So I also started using Falkon browser (in the distros), which works well but also has drawbacks (and advantages). Between the two browsers I can work all day as I had with Firefox.

There was only one problem: I'm addicted to NetFlix, neither of the two replacement browsers can view the movies. So, in the evening, after my work day I opened FireFox to view NetFlix. There was a freeze. So I bit the very bitter pill of downloading Chrome and use it to view NetFlix. And there was a freeze while watching a movie.

I currently use Chrome for NetFlix, it has only done the freeze once.

But the upshot is, I've not had any freezing as long as I have not had FIreFox or Chrome open. This is a random problem, yes. But. I could be assured of have at least 1 freeze per week, now I don't have them as long as I follow these rules.