Bug 460935 - Color picker applet is using a lot of CPU resources
Summary: Color picker applet is using a lot of CPU resources
Status: RESOLVED WORKSFORME
Alias: None
Product: kwin
Classification: Plasma
Component: effects-various (show other bugs)
Version: 5.26.1
Platform: Arch Linux Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2022-10-24 11:50 UTC by Dmitry Rubtsov
Modified: 2024-07-10 03:47 UTC (History)
6 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:
qydwhotmail: NVIDIA+


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Description Dmitry Rubtsov 2022-10-24 11:50:53 UTC
SUMMARY
When clicking Color Picker button to choose a color from screen, while in color picking mode, it causes high CPU usage, other apps becoming unresponsive, observed behavior as an example:
- Had a voice chat, I stopped hearing any audio from it until exiting color picking mode
- Were connected once through a remote connection, the app thought my PC is not even connected to the internet anymore after trying to pick a color.
- CPU fan speed rising up after few seconds, indicating high CPU usage.

STEPS TO REPRODUCE
1. Add Color Picker from Widgets
2. Click on dropper button

OBSERVED RESULT
High CPU usage, to point of causing other applications to halt until closing this mode.

EXPECTED RESULT
moderate CPU usage and letting other apps to continue working.

SOFTWARE/OS VERSIONS
Operating System: EndeavourOS (based on Archlinux)
KDE Plasma Version: 5.26.1
KDE Frameworks Version: 5.99.0
Qt Version: 5.15.6
Kernel Version: 6.0.2-arch1-1 (64-bit)

ADDITIONAL INFORMATION
Graphics Platform: X11
Comment 1 Nate Graham 2022-10-24 21:03:56 UTC
Cannot reproduce; no CPU spike for me when I click on the dropper but don't pick a color yet.
Comment 2 Dmitry Rubtsov 2022-10-25 05:23:27 UTC
A small update, not entire CPU is being used but seems only one or two physical cores is getting 100% usage by process called plasmashell when I use the color picker. Also trying to record with OBS shows me that Nvidia nvenc encoder failed to respond in 5 seconds, timed out. So it seems to be related to display, not particularly CPU. Again, halts my other apps, Discord for example. It could be me using nvidia gpu, but I'm not sure. Is there a way to profile a widget, without compiling and all that?
Comment 3 Fushan Wen 2022-10-25 16:39:41 UTC
I have amdgpu and also cannot reproduce. Should blame NVIDIA.
Comment 4 ratijas 2022-10-25 21:14:00 UTC
Can reproduce with NVIDIA, WTF.

Apps being unresponsive is kinda expected side effect, because color picker "freezes" the picture via KWin effects, and lets you select a color. But I certainly didn't expect them to become so unresponsive, up to the point that System Monitor -> History page don't get updated which the picture is "frozen". I can hear the fans go brrrr tho
Comment 5 Zamundaaa 2024-06-10 13:31:59 UTC
Is this still happening for you in Plasma 6?
Comment 6 Bug Janitor Service 2024-06-25 03:47:28 UTC
Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please
mark the bug as REPORTED so that the KDE team knows that the bug is
ready to be confirmed.

Thank you for helping us make KDE software even better for everyone!
Comment 7 Bug Janitor Service 2024-07-10 03:47:17 UTC
This bug has been in NEEDSINFO status with no change for at least
30 days. The bug is now closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

Thank you for helping us make KDE software even better for everyone!