19.04 systemd-udevd at 100%

[dwater]

Anyone any idea why this process is at 100% constantly?

[1fallen]

some folks have solved it by completely disabling Bluetooth from the BIOS.
Bugs on this have been filed: https://bugzilla.kernel.org/show_bug.cgi?id=199035
https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1759836
I know its for 18.04 but still happening.
But try a workaround to see if it helps:

Immediately after booting, run the following commands:


sudo systemctl stop systemd-udevd systemd-udevd-kernel.socket systemd-udevd-control.socket
sudo systemctl start systemd-udevd systemd-udevd-kernel.socket systemd-udevd-control.socket

If you need to dig deeper use:

udevadm monitor
This would be an example of many outcomes like:

monitor will print the received events for:
UDEV - the event which udev sends out after rule processing
KERNEL - the kernel uevent

Example of a faulty driver:

(random lines but repeating all the same indefinitely):

...
KERNEL[10072.040174] remove /module/nvidia (module)
UDEV [10072.062670] add /module/nvidia (module)
UDEV [10072.063617] add /kernel/slab/:A-0000256/cgroup/filp(40652:nvidia-persistenced.service) (cgroup)
UDEV [10072.076901] remove /module/nvidia (module)
UDEV [10072.109365] add /kernel/slab/:aA-0000192/cgroup/dentry(40652:nvidia-persistenced.service) (cgroup)
KERNEL[10072.138225] add /module/nvidia (module)
KERNEL[10072.139241] add /kernel/slab/:0012288 (slab)
KERNEL[10072.139651] remove /kernel/slab/:0012288 (slab)
...

this is caused by the fact that the nvidia driver is active but the nvidia card is disabled in BIOS.