Kioworker using processor core only when dolphin open

General system Newbie
1

Hi all

After a recent update (not sure exactly when, but probably since early April '25) I’ve noticed that one of my CPU cores is always being used whenever Dolphin is open. Using htop, I tracked this to kioworker.

If I exit Dolphin, the problem goes away - kioworker exits and the fan will reduce back down after a minute or so.

I tried searching on this forum and elsewhere but didn’t find anything concrete - at least nothing that stood out for me.

Can someone explain what is going on, whether this is normal and what, if anything, I can do to stop this from happening - I don’t recall it being like this previously and it effectively means I have to keep Dolphin closed if I don’t want the PC to be noisy.

Appreciate any insights.

1 Like
2

Here dolphin doesn’t cause that issue. kioworker starts but fans are not giving any more noise. And htop does not show them as consuming CPU time much.

I’d guess it could have something to do with your some mounts that aren’t getting ready for dolphin maybe? In file /etc/fstab there might be a problem?

3

Thanks for the reply.

I don’t think it’s the mounts - I have 2 NVME drives: main system and a data drive. Data is encrypted and only mounts when I go to it and I don’t use it that often. No other drives aside from that.
Partitioning on “system” is simple too

  1. /EFI
  2. /
4

journalctl might give some clue of what’s happening with dolphin and kioworker.

Tip: run

date ; dolphin

then run

sudo journalctl -b -0

and it should be easy to locate the event using the time info in the journal.

Alternatively using another file manager (like thunar) might be a workaround for the problem.

1 Like
5

The same issue. The Kioworker process always loads the processor at exactly 8.2-8.3 percent.

1 Like
6

Sorry about the delay in replying.

output from sudo journalctl -b -0

[xxxxxxxxx@pc ~]$ sudo journalctl -b -0 | grep kio
May 12 12:23:03 AMR5 kioworker[2116]: kf.coreaddons: "Could not load plugin from /usr/lib/qt6/plugins/kf6/thumbcreator/appimagethumbnail.so: Cannot load library /usr/lib/qt6/plugins/kf6/thumbcreator/appimagethumbnail.so: libappimage.so.1.0: cannot open shared object file: No such file or directory"
May 12 12:23:03 AMR5 kioworker[2116]: kf.coreaddons: "Could not load plugin from /usr/lib/qt6/plugins/kf6/thumbcreator/appimagethumbnail.so: Cannot load library /usr/lib/qt6/plugins/kf6/thumbcreator/appimagethumbnail.so: libappimage.so.1.0: cannot open shared object file: No such file or directory"
May 12 12:39:47 AMR5 kioworker[5884]: kf.kio.core.connection: Socket not connected QLocalSocket::PeerClosedError
May 12 12:39:47 AMR5 kioworker[5884]: kf.kio.core: An error occurred during write. The worker terminates now.
May 12 12:39:47 AMR5 kioworker[5884]: QThreadStorage: entry 9 destroyed before end of thread 0x60fec6016360
May 12 12:39:47 AMR5 kioworker[5884]: QThreadStorage: entry 2 destroyed before end of thread 0x60fec6016360
May 12 12:39:47 AMR5 kioworker[5884]: QThreadStorage: entry 1 destroyed before end of thread 0x60fec6016360
May 12 12:49:27 AMR5 kioworker[7485]: kf.kio.core.connection: Socket not connected QLocalSocket::PeerClosedError
May 12 12:49:27 AMR5 kioworker[7485]: kf.kio.core: An error occurred during write. The worker terminates now.
May 12 12:49:27 AMR5 kioworker[7485]: QThreadStorage: entry 9 destroyed before end of thread 0x5764aec75360
May 12 12:49:27 AMR5 kioworker[7485]: QThreadStorage: entry 2 destroyed before end of thread 0x5764aec75360
May 12 12:49:27 AMR5 kioworker[7485]: QThreadStorage: entry 1 destroyed before end of thread 0x5764aec75360
May 12 18:58:37 AMR5 kioworker[64060]: kf.coreaddons: "Could not load plugin from /usr/lib/qt6/plugins/kf6/thumbcreator/appimagethumbnail.so: Cannot load library /usr/lib/qt6/plugins/kf6/thumbcreator/appimagethumbnail.so: libappimage.so.1.0: cannot open shared object file: No such file or directory"
May 12 18:58:37 AMR5 kioworker[64060]: qt.gui.imageio.jpeg: Not a JPEG file: starts with 0x4d 0x4d
May 12 18:58:37 AMR5 kioworker[64060]: qt.gui.imageio.jpeg: Not a JPEG file: starts with 0x4d 0x4d
May 12 18:59:53 AMR5 kioworker[64060]: kf.kio.core.connection: Socket not connected QLocalSocket::PeerClosedError
May 12 18:59:53 AMR5 kioworker[64060]: kf.kio.core: An error occurred during write. The worker terminates now.
May 12 18:59:53 AMR5 kioworker[64060]: QThreadStorage: entry 9 destroyed before end of thread 0x625cd4302360
May 12 18:59:53 AMR5 kioworker[64060]: QThreadStorage: entry 2 destroyed before end of thread 0x625cd4302360
May 12 18:59:53 AMR5 kioworker[64060]: QThreadStorage: entry 1 destroyed before end of thread 0x625cd4302360

This isn’t redacted - that’s all since I switched on pc about 6 hours ago.

Strangely, the behaviour has changed somewhat and no update done.
Previously I would see it for any folder that had more than a handful of files.
Now kioworker only spins up if going into a new folder.

7

That 100% one core happens here when I have unfinished/still processing video and Dolphin/kio constantly tries to create a thumbnail.

Your log also seems related to thumbnail creation and complaining about a malformed jpg or appimage file.

Maybe installing libappimage fixes it, it’s an optional dependency for kio-extras.