I am relatively new to linux so please be patient with me if you try to help.
During the day I use my computer for work in which I have multiple programs running on a dual monitor setup. Usually, but not always, during the day at some seemingly random time the panel will freeze. I use a VM for work and have Virtual Box fullscreen on the monitor with the panel. This covers the panel so I have never actually seen this happen. I will minimize VB at some point and see that things are frozen. This has been happening since I started using linux as my primary OS, it didn’t just start happening after an update or something. I have just been dealing with it but would love to get help on figuring out what is causing it at least.
I can still use all the open programs without any real issues and I can open new programs using the terminal if I know how to call them and I can use key shortcuts. The only way I know of currently to unfreeze the panel is to reboot. I have tried restarting kwin with some commands I found online but they don’t seem to work. They do claim to be for Plasma 5 and I am on 6 so I assume that is why it isn’t working.
I do use this machine for gaming as well and after playing multiple games for many hours I have not had the same freezing issue. It’s only ever happened while I am working. I can only conclude it has something to do with one of the programs running at the time.
The 6 programs I typically have running are:
Betterbird (Thunderbird fork)
Vivaldi browser (flatpak version)
Dolphin w/split view
Virtual Box
qpdfview
LibreOffice (flatpak)
I have tried uninstalling the flatpak version of LibreOffice and using the non-flatpak version of LibreOffice calc. I tried using Firefox instead of Vivaldi. I tried these separately to keep the variables to a minimum and still got the freezing. I always have Betterbird open, even when gaming. So I don’t think it is any of these three programs. I would assume Dolphin isn’t the issue either since it’s a preinstalled program, but who knows for sure.
I am leaning towards VirtualBox or qpdfview being the culprit. Being relatively new to linux in general I don’t know what logs to look for or where to find them. I do have Gnome Logs installed and got the same 2 things appearing on the logs on two different days at the time of the freezes, based on the log times. There is also an icon that appears on the panel with the KDE icon but nothing pops up on the screen so I do not know what that is. I have multiple screenshots but can only post 1 at a time since I’m a new user. So first up are my specs
You can see the “QWindow” and “fuse: splice” lines once again.
Please let me know if there are any other logs I should look at or any ideas if you have any. I did upgrade from Plasma 5 to 6 if this is relevant.
So I have made some slight progress. I looked into “xdg-desktop-portal-kde” and “xdg-document-portal” and found others having issues with them in the past. One suggestion was to just kill that process. I went ahead and killed:
xdg-desktop-portal-kde
xdg-desktop-portal-gtk
xdg-desktop-portal
xdg-document-portal
processes hoping that the panel would resume, but it didn’t. I then found this post how to restart plasma panel where I started trying the commands in the fourth post:
systemctl restart --user plasma-plasmashell
which just seemed to hang in the terminal. So I cancelled that with ctrl + c and tried the second suggestion:
plasmashell --replace
which did replace my frozen panel with a working one.
Now that I have some results I will try to narrow down which processes, if any, are the true culprits next time I get a freeze. Perhaps just running the replace command will get it up and running again. That will be the first test…
Following up on this, I recently created a clean install of Fedora 40 Kinoite. It appears that this freeze occurs without fail every single time Spotify changes songs, but only when I have the built-in “Media Player” applet on the panel. Using a different applet does not cause this lock-up. Has anyone else been able to figure out what causes the issue for them?
So I still have not found a solution to this, but I have found ways to make it a bit easier on myself. I found that if I kill the xdg-desktop-portal-kde and xdg-document-portal processes and then run systemctl restart --user plasma-plasmashell it will restart the panel and I can continue using my computer without needing to do a full restart. I usually close all my running programs before doing so just to prevent losing any data. I need to restart my email client after running it also. If I don’t then I can’t add attachments to emails.
Previously I stated that running systemctl restart --user plasma-plasmashell didn’t seem to work for me, but I think I just didn’t give it enough time to do it’s thing.
To make this process even easier I setup this alias: alias rplasma='kill $(pidof xdg-desktop-portal-kde); kill $(pidof xdg-document-portal); systemctl restart --user plasma-plasmashell'
This kills the two aforementioned processes without needing to lookup their PIDs and then runs the restart plasmashell command all by typing rplasma into the terminal.
It takes probably 30 seconds to a minute to actually restart plasmashell. So it can seem like nothing is happening, just give it time.
The weird thing is that after I run through this process I can usually go many days without the panel freezing again. Not sure why that is.
I have the exact same observations — the Media Player widget seems to have caused* the freezing.
At first I thought it could be related to kwin (which sometimes crashes in 6+ too), but the freezing was* of much higher frequency than kwin crashes. Also, kwin crashes prompted me to report (which I did), Panel froze somewhat silently (required manual killing of plasmashell during its high CPU usage).
Often, expanding the Media Player widget (by clicking with the mouse) was the action that triggered the Panel freezing and high plasmashell CPU usage alone.
Other times, the issue popped seemingly at random times. Yet, always with the Media Player widget on the Panel. I tested one day with Media Player widget removed from the Panel, and haven’t experienced any issues then. I really can’t live without this little widget though, so one day of testing was excruciating enough
I have then tested a few (certainly more than 5) different music players (some of them also both as flatpak and native) to no avail. Actually even just playing audio through Firefox with the widget on Panel was enough to cause the freezing.
I didn’t do any “official” debugging as I haven’t yet learned how to debug the widget. I tried scouting the logs for plasmashell related causes using some command posted on the forum by Nate (if I remember correctly something along the lines of “core” and “dump”), before I recognized the Media Player widget as probable culprit, but couldn’t identify the issue there in the logs.
* I write in past tense because since updating to 6.2 on Fedora 40 I have not experienced the issue