Dell, bluez-qt and high CPU usage by systemd-udevd

Hello everyone!

Recently, I guess after an update, my Manjaro KDE install on my Dell XPS 9570 started to fully use a CPU thread all the time, which of course drains the battery, and makes the computer hot and noisy.

The process using 100% of a thread was systemd-udevd, and I have narrowed the problem to a package: bluez-qt. From what I could gather, there is a bug which causes and endless loop, hence taking up a lot of CPU.

So far, I have tried to roll back to the latest LTS kernel (5.4.74-1), disabled the bluetooth from the BIOS (still disabled now), removing the package bluez and bluez-qt (with pacman -Rdd, in order not to remove dependancies such as powerdevil). It seems that only removing the last one (bluez-qt) has an effect, and make the process using a lot of CPU vanish. If I had to renounce to bluetooth on my laptop, it would not be a problem, since I never used it in more than 2 years, but the problem is that for some reason, uninstalling bluez-qt breaks a dependency, and basically I cannot access the power option anymore (I can’t set the time after which the computer suspends, etc).

When I go to the Power Management settings in KDE Plasma, here’s the error I get: Cannot load library /usr/lib/qt/plugins/ ( cannot open shared object file: No such file or directory)

Could it be possible to bypass that in order to continue to have access to these settings, which are fairly important? Thanks in advance!

Also, if it helps you: the battery icon disappears from the system tray applet in a panel, but I can still access the battery percentage via the specific battery indicator widget, and I can still access the energy consumption too.

is provided by powerdevil package. Either you had a partial update or something got corrupted.
sudo pacman-mirrors -f && sudo pacman -Syyu powerdevil

Thank you for your answer.
Actually, doing this forces me to reinstall bluez and bluez-qt, which causes my problem. Reinstalling powerdevil with pacman -Sdd doesn’t not work either (bluez* are not reinstalled, but I still can’t access the power management settings).

Same strange udev behavior on MSI GS637RD laptop as well. CPU usage is not that high like in your case, but stays steady at about 25% draining resources.

In my case, stopping the bluetooth service and restarting the systmed-udevd brings everything to normal. So I think, you may try installing the bluez-qt back and then

systemctl disable --now bluetooth

to stop and disable the bluetooth and

systemctl restart systemd-udevd

to restart the udevd service.

udevadm monitor to see what’s going on with udev after that.

In my case it is a bit more complicated because I use bluetooth every now and then so identifying and fixing the root cause would be much better.

@alive some problem with GS63VR.

I try disable bluetooth, but It does not work.

Hey, I have the MSI GS62 and experienced the same issue. In my case it was due to using the MSIKLM tool to configure the backlight. Disabling the udev rule fixed the issue. Check my reply over here for more details.

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