Bug 508550

Summary:	System freezes on login to Plasma (Wayland) due to "powerdevil" consuming 220%+ CPU
Product:	[Plasma] plasmashell	Reporter:	Nikita <gogoevich154>
Component:	Power management & brightness	Assignee:	Plasma Bugs List <plasma-bugs>
Status:	RESOLVED WORKSFORME
Severity:	major	CC:	kdedev
Priority:	NOR
Version First Reported In:	master
Target Milestone:	1.0
Platform:	Arch Linux
OS:	Linux
See Also:	https://bugs.kde.org/show_bug.cgi?id=500835
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Nikita 2025-08-21 06:51:47 UTC

SUMMARY
System freezes on login to Plasma (Wayland) due to `powerdevil` consuming 220%+ CPU

STEPS TO REPRODUCE

1. Install Arch Linux and the `plasma-meta` package.
2. Log in to Plasma (Wayland) session via SDDM.
3. Wait for the loading gear animation to freeze.

OBSERVED RESULT

- Plasma session hangs after the gear animation freezes.
- Entire system becomes unresponsive.
- Switching to TTY shows `powerdevil` process consuming 220%+ CPU (confirmed via `btop`).
- After killing `powerdevil` with `killall`, the system becomes responsive again.

EXPECTED RESULT
Plasma (Wayland) session should start normally without `powerdevil` consuming excessive CPU or freezing the system.

SOFTWARE/OS VERSIONS
Operating System: Arch Linux
KDE Plasma Version: 6.4.4
KDE Frameworks Version: 6.17.0
Qt Version: 6.9.1
Kernel Version: 6.16.1-arch1-1 (64-bit)
Graphics Platform: Wayland
Processors: 4 × AMD Ryzen 3 3200U with Radeon Vega Mobile Gfx
Memory: 8 GiB of RAM (5.7 GiB usable)
Graphics Processor: AMD Radeon Vega 3 Graphics
Manufacturer: Acer
Product Name: Aspire A315-42
System Version: V1.08

ADDITIONAL INFORMATION

- The issue also occurs on live USB sessions of EndeavourOS and CachyOS (Plasma Wayland).

Comment 1 TraceyC 2025-08-21 21:37:18 UTC

I've not seen this on git-master or Plasma 6.4.4.
Can you please let us know what version of ddcutil is on your system? We had seen similar performance issues with 2.2.0.

Also, I'd like to ask for profiling with hotspot -  https://github.com/KDAB/hotspot?tab=readme-ov-file#using

You would record the powerdevil process with perf, while it's using high CPU. Then, look at the flamegraph in hotspot, to see where it consumes the most cycles. Hopefully, this will give us some information to go on.

Thanks.

Comment 2 Bug Janitor Service 2025-09-05 03:48:20 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 3 Bug Janitor Service 2025-09-20 03:48:21 UTC

🐛🧹 This bug has been in NEEDSINFO status with no change for at least 30 days. Closing as RESOLVED WORKSFORME.