Bug 488871

Summary: `kwin_x11` hogs CPU
Product: [Plasma] kwin Reporter: Thorolf E.R. Weißhuhn <terw>
Component: performanceAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED FIXED    
Severity: normal CC: nate
Priority: NOR    
Version First Reported In: 6.0.5   
Target Milestone: ---   
Platform: openSUSE   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: system monitor showing high cpu usage of kwin_x11

Description Thorolf E.R. Weißhuhn 2024-06-21 07:50:32 UTC
Created attachment 170726 [details]
system monitor showing high cpu usage of kwin_x11

(this is likely reported in the wrong place, please move where it belongs)


SUMMARY

Since an update a week ago (Discover > update all > reboot), the `kwin_x11` hogs CP. Consequently, the machine becomes hot and the fan is always running high.

That CPU usage is usually in the th 20..35% range, even when `kwin_x11` is sleeping. 

STEPS TO REPRODUCE

1. Update
2. Reboot


OBSERVED RESULT

As stated above and in screenshot.


EXPECTED RESULT

`kwin_x11` should burn much less cycles.


SOFTWARE/OS VERSIONS

Operating System: openSUSE Tumbleweed 20240613
KDE Plasma Version: 6.0.5
KDE Frameworks Version: 6.3.0
Qt Version: 6.7.1
Kernel Version: 6.9.3-1-default (64-bit)
Graphics Platform: X11
Processors: 8 × 11th Gen Intel® Core™ i7-1165G7 @ 2.80GHz
Memory: 31,1 GiB of RAM
Graphics Processor: llvmpipe


This may be related to #465424; like there, I use an external HDPI monitor on a laptop.
Comment 1 Thorolf E.R. Weißhuhn 2024-06-22 10:28:18 UTC
I cannot reproduce now. Went back to a system snapshot about 2 weeks old, then a summary update (Discover) of all ~1.6k updates, now kwin_x11 stays in the lower 1-digit cpu usage percent.

Changing to resolved.