After fresh start, there are 3 instances of udevd --deamon. After restarting udev by init there are 2 or 1 (seen to be random) udevd --deamon running. Reproducible: Always Steps to Reproduce: 1. Boot system.
Thats a feature, not a bug. Udev daemon does fork worker processes once it gets work to be done. Later those are idle and wait for new stuff to do. Run pstree to see that all of these are children of one udevd process.
Closing as per Comment #1