Bug 500402 - Excess CPU usage from png_read_image
Summary: Excess CPU usage from png_read_image
Status: REPORTED
Alias: None
Product: kwin
Classification: Plasma
Component: performance (other bugs)
Version First Reported In: 6.3.0
Platform: Other Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-02-19 12:54 UTC by derp
Modified: 2025-02-25 19:24 UTC (History)
2 users (show)

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

Attachments
sysprof screenshot (2.50 MB, image/png)
2025-02-19 12:54 UTC, derp 		Details
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Description derp 2025-02-19 12:54:27 UTC 
Created attachment 178584 [details]
sysprof screenshot

SUMMARY

I noticed excess cpu usage from png_read_image when benchmarking maximize-unmaximize scenario, related to SVG rendering.
This png loading can likely be cached.
I am not sure if it's related to the cursor or the window decoration drawing app icon.

The tested app was Discord with ozone Wayland.

STEPS TO REPRODUCE
1. Maximize the window by dragging to the top and then back to unmaximize
2. Repeat several times
3. Observe sysprof results

OBSERVED RESULT


EXPECTED RESULT


SOFTWARE/OS VERSIONS
Windows: 
macOS: 
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma: Fedora 41 AMDGPU
KDE Plasma Version: 6.3.0 
KDE Frameworks Version: 6.11.0 
Qt Version: 6.8.2

ADDITIONAL INFORMATION

attached sysprof screenshot