Bug 464718

Summary:	NVIDIA Optimus: When using NVIDIA GPU on X11, high CPU usage when switching to different TTY
Product:	[Plasma] plasmashell	Reporter:	Oleksii Zolotarevskyi <rockingcat>
Component:	generic-performance	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	kde, nate
Priority:	NOR	Keywords:	X11-only
Version First Reported In:	5.26.4
Target Milestone:	1.0
Platform:	Manjaro
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Oleksii Zolotarevskyi 2023-01-23 23:29:32 UTC

SUMMARY
After switching to different TTY with Ctrl+Alt+F2, the process "plasmashell" starts using 100% CPU. The cooling fans also begin to ramp up.
Only happens when Nvidia is set as primary GPU. Doesn't happen when using Intel graphics.
When all non standard tray apps are closed, the problem persists.
When process "plasmashell" is killed, the CPU usage returns to normal.

STEPS TO REPRODUCE
1. Log into Plasma session
2. Switch to different TTY

OBSERVED RESULT
Process "plasmashell" starts using 100% CPU, when checked in "top".
Cooling fans ramp up.

EXPECTED RESULT
Process "plasmashell" doesn't use 100% CPU.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Manjaro Stable
KDE Plasma Version: 5.26.4
KDE Frameworks Version: 5.101.0
Qt Version: 5.15.7
Graphics Platform: X11

ADDITIONAL INFORMATION:
Laptop with Nvidia+Intel graphics
Nvidia driver version: 525.60.11

Comment 1 Nate Graham 2025-01-09 20:42:07 UTC

Sorry it took us so long to get to this. Are you still able to reproduce the issue in Plasma 6.2.5 or later? I can't try to reproduce it myself since I have no NVIDIA hardware.

Thanks!

Comment 2 Oleksii Zolotarevskyi 2025-01-10 02:36:12 UTC

No problem!
Unfortunately still present on Arch with Plasma 6.2.5

Comment 3 Bug Janitor Service 2025-01-25 03:47:03 UTC

🐛🧹 ⚠️ This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information, then set the bug status to REPORTED. If there is no change for at least 30 days, it will be automatically closed as RESOLVED WORKSFORME.

For more information about our bug triaging procedures, please read https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging.

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

Comment 4 Oleksii Zolotarevskyi 2025-01-25 11:04:00 UTC

Hi, just to clarify. The issue is still present in Plasma 6.2.5.

Comment 5 Nate Graham 2025-05-09 17:56:07 UTC

OK, next question: does it happen on Wayland too, or only on X11?

Comment 6 Oleksii Zolotarevskyi 2025-05-10 19:56:01 UTC

(In reply to Nate Graham from comment #5)
> OK, next question: does it happen on Wayland too, or only on X11?

As far as I know, on Wayland there is no way to set Nvidia as primary GPU, therefore it can only be reproduced on X11.