For months I have been plagued with this annoying problem on my MSI GX620 laptop. At some point I upgraded my version to udev to 151.X and began to notice that the udevd process was using around 25% of my cpu. After months of putting up with poor battery life and a scalding hot keyboard I found a solution.
The problem was a result of a poorly implemented firmware on the Optiarc RW_AD_7560S on my GX620. Installing the newer firmware located here took care of the problem immediately. This updates the firmware to version SD05. I had to boot into windows and ran the executable in the 'win' folder.
Booting into linux, the problem was immediately solved.
Happy computing :)