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Deinorius

Member

Registered: 2024-08-11

Posts: 4

Mid CPU utilization exactly every 30 minutes without clue

Hello.

I'm not really a newbie, but in this case I absolutely have no idea, where to start searching for clues to solve this issue.
For quite a long time I have this Qt bug, that can be circumvented with an environment variable, but because of this bug I initially thought this might be an issue with Plasma, but when I look in btop, I get shown the utilization but no info about what package it causes. I added screenshots about this.
Temperatures get quite high. Duration is about 30-60 s long, but connected to my DockingStation I sometimes noticed around 100 s or more too.

I looked at dmesg and journal outputs and there's nothing that would give any hint, why this is happening, especially because it happens every 30 min. The time changes with the moment I wake up my laptop from standby, but it happens after a cold boot as well.
The only messages in journal at these times are temperature notifications from thinkfan and this (but those are shown all the time):

rtkit-daemon[1697]: Supervising 0|1 threads of 0|1 processes of 0 users.

Here, you can see it at that moment. It's not a high utilization, but temperature gets quite high, and thus it lets the fan kick in noticeably. So I notice this every time. Running with battery, temperatures are low enough and the duration seems to be shorter, but because I don't have btop always on top, it might differ.

CPU utilization while happening

This screenshot shows the bug with added GPU util. This is completely random and right now, I can't say I've seen it lately.

CPU and GPU utilization

Here the GPU utilization changed when I brought up the system panel, but contrary to the Qt bug, where GPU utilization goes through the roof while the system panel is hidden - here it goes up, when the panel isn't hidden. WTF?!

GPU utilization changing with system panel

I hope, someone has an idea. I don't know what to do.

Last edited by Deinorius (2025-11-10 15:39:15)

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 75,086

Re: Mid CPU utilization exactly every 30 minutes without clue

It's not only more percentage, the CPU steps up from 400MHz to 3.8GHz (that's driving the temperature)

I initially thought this might be an issue with Plasma, but when I look in btop, I get shown the utilization but no info about what package

exactly every 30 minutes without clue

Run not-plasma for an hour, do you still get those spikes?

Edit: and try eg. the LTS kernel, maybe some module is going wild.

Last edited by seth (2025-11-10 20:16:43)

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Deinorius

Member

Registered: 2024-08-11

Posts: 4

Re: Mid CPU utilization exactly every 30 minutes without clue

Definitely worth a try. I'll hopefully get back with something.