Bug 477976

Summary: system-monitor incorrectly reports CPU usage as 0% when it is close to 100%
Product: [Applications] plasma-systemmonitor Reporter: Nick Korotysh <tevute56>
Component: generalAssignee: KSysGuard Developers <ksysguard-bugs>
Status: RESOLVED FIXED    
Severity: normal CC: ahiemstra, fanzhuyifan, plasma-bugs-null, putr4.s
Priority: NOR Keywords: qt6
Version First Reported In: 5.90.0   
Target Milestone: ---   
Platform: Arch Linux   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: htop vs system-monitor

Description Nick Korotysh 2023-12-03 09:33:46 UTC
Created attachment 163806 [details]
htop vs system-monitor

SUMMARY
***
when all core are under high load (close to 100%), system monitor displays 0% CPU usage (both for total and per core)
***


STEPS TO REPRODUCE
1. open system monitor or add widget displaying CPU usage
2. run CPU-heavy task, for example compilation or 7z benchmark (7z b 10)
3. compare usage in system monitor and htop

OBSERVED RESULT
CPU usage is 0%, only sometimes reaches 100% for some core

EXPECTED RESULT
CPU usage is close to 100% for all cores

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: ArchLinux/KDE Plasma 6 Beta, Wayland
KDE Plasma Version: 5.90.0
KDE Frameworks Version: 5.246.0
Qt Version: 6.6.1

ADDITIONAL INFORMATION
not 100% usage seems to be reported correctly, see attached screenshot
Comment 1 Nick Korotysh 2023-12-21 00:01:29 UTC
fixed in 5.91, can be closed