After running for a while, `plasmashell` hogs the CPU.

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leyvi · Post by **leyvi** » Fri Jul 11, 2025 3:21 pm

I've been logged in for a few hours, and it's almost always at 100% usage, and RAM usage is now at nearly 2GiB. My system is almost unresponsive half the time. This has happened loads of times recently. Help!

rab0171610 · Post by **rab0171610** » Fri Jul 11, 2025 3:45 pm

This could happen with misbehaving plasmoids, themes, corrupt config files in the home directory, backgrounds and general user customization. To eliminate that as the cause it is recommended to log in as a new user to verify whether or not you can replicate the behavior. New users would be using a fresh home directory with the default KDE configuration.

If you cannot replicate it with a new user, then you can decide if you want to completely move or delete your kde config files and start with a fresh configuration or try moving them individually to try isolating the file that is causing the problem.

If you can replicate it with a new user, then the user configuration is likely eliminated as a contributing factor.

I would then give more information about your setup, your hardware (CPU, graphics, how much RAM), your emerge --info and any relevant information about your KDE installation as everyone's is not always the same on Gentoo.

You can also hit Alt+F2 to launch krunner and enter

Code: Select all

plasmashell --replace

to refresh the plasmashell. You can then monitor the behavior to try and understand what may be triggering the issue to occur.

If all else fails, you can file bugs upstream at KDE. They are usually very responsive and helpful. You can also search bug reports both at Gentoo and KDE to see if anything matches what you are experiencing.

leyvi · Post by **leyvi** » Sat Jul 12, 2025 5:52 pm

I think I should probably start with an upstream bug report.
I doubt this is desired behavior.

Goverp · Post by **Goverp** » Sat Jul 12, 2025 6:29 pm

leyvi,
I have what may be similar behaviour (though probably not) on one of my KDE userids (I have several on the same PC). KDE starts a process that should produce thumbnail previews of Desktop folders. On the other userids, this happens without problem, but on the problematic one it loops, hogging one CPU. On my desktop with 16 CPUs it isn't noticeable, but on my laptop with just two, ah, that's noticeable! The looping process continues even if I leave KDE and return to the command line. If I then reenter KDE, it starts a second CPU hog. They need SIGKILL to get rid of them.

It's a reported bug, but then so many things are.

The bypass is to enter KDE settings and switch off Desktop previews, wherever that is.

leyvi · Post by **leyvi** » Sat Jul 12, 2025 7:53 pm

Goverp wrote:The bypass is to enter KDE settings and switch off Desktop previews, wherever that is.

Sounds promising, but I couldn't find it (I searched for things like "preview").

Goverp · Post by **Goverp** » Sun Jul 13, 2025 10:58 am

Sorry, it's Desktop Folder Settings (RMB on the Desktop); go to the Icons tab; at the bottom there's "Previews - show preview thumbnails".
I note there's a button to list plugins - I bet there's one that's the problem on my system, but I need to bisect this button to find it...

leyvi · Post by **leyvi** » Sun Jul 13, 2025 11:11 am

Ah, I'm using widgets, so that's a no-go. What do I do instead?

!!! · Post by **!!!** » Sun Jul 13, 2025 2:01 pm

Does this happen to be baloo?

I had this problem after downloading the High Voltage SID Collection. Apparently, some indexing process wanted to know how the duration of those files. These files tend to loop forever and that kept the process busy.

rab0171610 · Post by **rab0171610** » Sun Jul 13, 2025 2:48 pm

leyvi wrote:Ah, I'm using widgets, so that's a no-go. What do I do instead?

Which is exactly the reason your need to test using a new user with the default configuration. Widgets aka Plasmoids, especially activity, system, disk, memory and system monitors have been known to cause issues like this. Eliminate that as the cause by using the system as a new user with the default configuration. At that point, you would move onto the next step of troubleshooting. Until then you are just grasping at straws. It will also save time if you decide to file a bug report as you can detail the steps you took to eliminate themes, plasmoids and user settings as a factor. This would also help the KDE Devs, who will probably ask you to do that in some form anyway. If that does not isolate the issue, then you can start trying the next steps, like disabling indexing if that is enabled (baloo), etc. If all else fails or you run out of ideas, then you file a bug, detailing all the troubleshooting steps you took to isolate the issue. Or you can just throw your hands up I guess.

wildhorse · Post by **wildhorse** » Mon Jul 14, 2025 8:07 am

Maybe Plasma's Hell is just doing exactly what it is suppose to do.

You could monitor your ill behaving system with top and irqtop.