Bug 510886

Summary:	With NVIDIA GPU, using a color-scheme-following Plasma style makes popups take longer to open
Product:	[Plasma] plasmashell	Reporter:	Luan Vitor Simião Oliveira <luanv.oliveira>
Component:	Panel	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	CONFIRMED ---
Severity:	normal	CC:	kdedev, mikel5764, nate, niccolo.venerandi, noahadvs, rotlug77
Priority:	NOR	Keywords:	efficiency-and-performance
Version First Reported In:	6.3.4
Target Milestone:	1.0
Platform:	Fedora RPMs
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	flamegraph video demo perf profile color wheel

Description Luan Vitor Simião Oliveira 2025-10-21 20:20:07 UTC

SUMMARY
kickoff takes ~150ms to open after i release the <super> key on my keyboard.
runing a profile on plasmashell process while spamming the super key reveals that it spends quite some time on PlasmaTheme::syncColors() 

STEPS TO REPRODUCE
1. press and release <super> key
2. wait for kickoff to show up

OBSERVED RESULT
kickoff shows up 150ms after the key is released

EXPECTED RESULT
kickoff shows up 33.3ms to  66.6ms after the key is released


SOFTWARE/OS VERSIONS
Operating System: Fedora Linux 42
KDE Plasma Version: 6.4.5
KDE Frameworks Version: 6.19.0
Qt Version: 6.9.2
Kernel Version: 6.16.12-200.fc42.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 9800X3D 8-Core Processor
Memory: 32 GiB of RAM (30.5 GiB usable)
Graphics Processor 1: NVIDIA GeForce RTX 4070 Ti SUPER (580.95.05)
Graphics Processor 2: AMD Radeon Graphics
Manufacturer: ASUS

ADDITIONAL INFORMATION
attached is a 480fps video sped down to 30 demonstrating the issue (the light flicker is at 60hz so you can that as a time reference)
will also attach a flame graph and the perf trace

Comment 1 Luan Vitor Simião Oliveira 2025-10-21 20:26:50 UTC

Created attachment 185972 [details]
flamegraph

Comment 2 Luan Vitor Simião Oliveira 2025-10-21 20:57:40 UTC

Created attachment 185976 [details]
video demo

Comment 3 Luan Vitor Simião Oliveira 2025-10-21 21:11:50 UTC

Created attachment 185977 [details]
perf profile

Comment 4 TraceyC 2025-10-22 20:31:58 UTC

Thanks for the bug report and the detailed troubleshooting! The developers will take a closer loko.

Comment 5 Nate Graham 2025-10-23 15:28:01 UTC

Indeed, thanks a lot for the helpful debugging! Are you using the default Breeze Plasma Style/color scheme, or any non-default ones?

Comment 6 Luan Vitor Simião Oliveira 2025-10-23 17:29:05 UTC

i am using only the plasma and color theme from here: https://github.com/juxtopposed/Mystical-Blue-Theme/

Comment 7 Nate Graham 2025-10-23 17:32:30 UTC

Thanks. And does the issue happen with the default Breeze Global Theme?

Comment 8 Luan Vitor Simião Oliveira 2025-10-23 17:46:27 UTC

upon Furter testing this only happens if the selected plasma theme does not have the little color wheel in the corner (including plasma light/dark)

Comment 9 Luan Vitor Simião Oliveira 2025-10-23 17:47:46 UTC

Created attachment 186049 [details]
color wheel

Comment 10 Luan Vitor Simião Oliveira 2025-10-23 17:51:06 UTC

(In reply to Luan Vitor Simião Oliveira from comment #8)
> upon Furter testing this only happens if the selected plasma theme does not
> have the little color wheel in the corner (including plasma light/dark)

clarification: the themes called "breeze light/dark" have the slow behavior while just "Breeze" does not

Comment 11 Nate Graham 2025-10-23 18:18:24 UTC

Thanks a lot. Looks like it's Bug 503506. This bug report you opened is much better with the debugging, so I'm going to forward dupe that one to this one.

Comment 12 Nate Graham 2025-10-23 18:19:02 UTC

*** Bug 503506 has been marked as a duplicate of this bug. ***