Bug 435477

Summary:	High polling rates misreport CPU usage as 0% with spikes
Product:	[Unmaintained] ksysguard	Reporter:	zgoethel12
Component:	ksysguard	Assignee:	KSysGuard Developers <ksysguard-bugs>
Status:	RESOLVED UNMAINTAINED
Severity:	normal	CC:	joseph, plasma-bugs-null, zgoethel12
Priority:	NOR	Keywords:	efficiency-and-performance
Version First Reported In:	5.21.3
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	Comparing the KSysGuard output to htop, which shows the expected CPU usage.

Description zgoethel12 2021-04-07 17:29:42 UTC

Created attachment 137411 [details]
Comparing the KSysGuard output to htop, which shows the expected CPU usage.

SUMMARY
When the "System Load" tab has a polling rate any faster than 0.5s, CPU load reports as 0% with occasional spikes.  Running a system stress results in occasional spikes of 100%.  The graph draws correctly if the window is rapidly resized.

https://www.youtube.com/watch?v=bkeOvN3hOH0

STEPS TO REPRODUCE
1. Use KDE Plasma/Arch kernel 5.12rc
2. Run all-core stress test
3. Set "System Load" tab to refresh every 0.01s

OBSERVED RESULT
CPU usage is reported as 0% with occasional momentary spikes to 100%.

EXPECTED RESULT
CPU usage should be pegged at 100% as reported in htop.


SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma:
(available in About System)
KDE Plasma Version: 5.12.3
KDE Frameworks Version: 5.80.0
Qt Version: 5.15.2

ADDITIONAL INFORMATION
Kernel 5.12.rc.d0314.g1e28eed-1
AMD Radeon RX 570 4GB
Compositor in OpenGL mode

Comment 1 Christoph Cullmann 2024-09-23 20:59:43 UTC

ksysguard is no longer maintained, in Plasma 6 there is the Plasma system monitor for this task.

If your issue still happens with the Plasma 6 replacement, please re-open and we can move this bug to the new product, thanks!