Bug 499959 - With Plasma 6.3.0 the CPU usage shown in Mission Center never goes below 5% on Debian
Summary: With Plasma 6.3.0 the CPU usage shown in Mission Center never goes below 5% o...
Status: RESOLVED UPSTREAM
Alias: None
Product: plasmashell
Classification: Plasma
Component: general (other bugs)
Version First Reported In: 6.3.0
Platform: Debian unstable Linux
: NOR normal
Target Milestone: 1.0
Assignee: Plasma Bugs List
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-02-13 06:08 UTC by John
Modified: 2025-02-14 06:18 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed/Implemented In:
Sentry Crash Report:


Attachments
Minimum possible CPU usage in Mission Center (180.38 KB, image/png)
2025-02-13 06:08 UTC, John
Details

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Description John 2025-02-13 06:08:18 UTC
Created attachment 178249 [details]
Minimum possible CPU usage in Mission Center

SUMMARY
With Plasma 6.3.0 the CPU usage never goes below 5% on Debian

STEPS TO REPRODUCE
1. Use Debian with the 'unstable' (Sid) repository.
2. Go into a virtual terminal with CTRL+ALT+ F3.
3. Run: sudo apt update.
4. Run: sudo apt full-upgrade.
5. Run: sudo systemctl reboot.

OBSERVED RESULT
Since I upgraded from Plasma 6.2.5 to 6.3.0, the CPU usage shown in Mission Center never goes below 5%.
The CPU usage in Plasma's System Monitor varies a lot and changes very quickly and I can see 1% and even 0. something, so below 1%, but it changes so quickly that is hard to see exactly 0. what it is. I guess the lowest there was 0.8 something.

EXPECTED RESULT
I expect that Mission Center, which seems to be actively developed by more developers, so a bit more trusted, is able to show again a minimum of 2% CPU usage when the computer is idle and no program is open.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma:
KDE Plasma Version: 6.3.0
KDE Frameworks Version: 6.10.0
Qt Version: 6.7.2
Kernel Version: 6.12.13-amd64 (64-bit)
Graphics Platform: Wayland


HARDWARE SPECIFICATIONS
Hardware: Laptop Dell Inspiron 5770 (17" 1080p@60Hz screen)
CPU: Intel® Core™ i5-8250U CPU @ 1.60GHz
GPU 1: Mesa Intel® UHD Graphics 620 (main)
GPU 2: AMD Radeon R5 M465 Series
RAM: 8 GiB (7.7 GiB usable)


ADDITIONAL INFORMATION
Debian weekly build downloaded from here:
https://cdimage.debian.org/cdimage/weekly-builds/amd64/iso-dvd/
Was installed and then switched from its 'testing' repository to the 'unstable' repository in this file:
/etc/apt/sources.list
Then Plasma was upgraded from version 6.2.5 to 6.3.0 from a virtual terminal with the 'sudo apt full-upgrade' command.
The screen's color accuracy is the default: Prefer efficiency.

BTW, I had to do multiple printscreens to be able to capture 5% as a lot of time by time the capture was done, it switched to 6% usage.
Comment 1 duha.bugs 2025-02-13 19:26:39 UTC
Mission Center is not developed by KDE. You will have to report the bug to them: https://gitlab.com/mission-center-devs/mission-center/-/issues
Comment 2 John 2025-02-14 06:18:47 UTC
(In reply to duha.bugs from comment #1)
> Mission Center is not developed by KDE. You will have to report the bug to
> them: https://gitlab.com/mission-center-devs/mission-center/-/issues

I understand that it's not developed by KDE, but I wanted to report a higher CPU usage just by upgrading Plasma from version 6.2.5 to 6.30 as everything else stayed the same (the computer, the OS, Mission Center).
And since Htop, that I like a lot and use from time to time is not able to give me a single percentage value of usage and Plasma's System Monitor just fluctuates a lot and too fast to figure out what is the average CPU usage like for the past minute, I had to use another tool and this one is the best, in my opinion.

I did a few more tests and I thing I figured out a problem with my before and after value.
I discovered that if I change in Plasma's Power and Battery widget the Power profile from "Power save" to "Balanced" the CPU usage shown in Mission Center can reach again 2% on idle.
Have a look:
https://imgur.com/WQe7wxS
Same with the Power profile set to "Performance"
Because of that I started looking for another independent option to understand if this different CPU usage problem depending on the power profile is a problem in Mission Center or Plasma, so:

I've taken this CPU measuring usage command that gives a single percentage value:
grep 'cpu ' /proc/stat | awk '{usage=($2+$4)*100/($2+$4+$5)} END {print usage "%"}'
From:
https://stackoverflow.com/a/9229580
And combined it with:
while script; do sleep 10; done
From:
https://stackoverflow.com/a/25158585
As I could not make it work with the 'watch' command.

The result being this command (which probably works better than with the 'watch' command as you can see a history of values).

while grep 'cpu ' /proc/stat | awk '{usage=($2+$4)*100/($2+$4+$5)} END {print usage "%"}'; do sleep 1; done;

I've switched the power profile and ran if for all 3 of them and it got me these results:
--------------------------------Power Save--------------------------------
5.06676%
5.0661%
5.06542%
5.06474%
5.0641%
5.06342%
5.06272%
5.06206%
5.06142%
5.06076%
--------------------------------Balanced--------------------------------
5.05539%
5.05476%
5.05411%
5.05347%
5.0528%
5.05217%
5.0515%
5.05088%
5.05024%
5.04962%
--------------------------------Performance--------------------------------
5.03792%
5.03726%
5.03656%
5.03585%
5.03515%
5.03445%
5.03376%
5.03304%
5.03234%
5.03166%

So the CPU usage is always around 5% (though decreasing a bit with the higher power profile) and most likely it was the same for Plasma 6.2.5 too and probably I had looked at it while having the Power profile set as "Power save" and didn't know that Mission Center would display an inaccurate result because of it.
I will try to report it upstream.
Good that Plasma 6.3.0 doesn't have a higher CPU usage than the previous one without any good reason!