I just gave in to the App Store's constant nagging about upgrading to Yosemite. Aside from an unhappy Chrome, there is this `kextd` process that's constantly running close to 95% CPU. This results in the fan also running constantly and my battery being drained.

Things I tried but didn't work:

* removed all the `.plist` files
* upgraded to 10.10.1 when it came out this morning
* called Apple support who had me delete a cache file (`/System/Library/Caches/com.apple.kext.caches/Startup/kernelcache/loadedkextmt.plist`)

The process doesn't start straight at boot, but maybe 10 minutes later during use.

How can I get this `kextd` process to quiet down?