How do I debug an out-of-control "kernel_task" process?
I had a similar question about how to identify files and programs connected to kernal_task using the following terminal command:

kextstat -l -k | awk '{n = sprintf("%d", $4); print n, $6}' | sort -n


This will display various kexts and the memory associated with them.  For example, 6184960 com.apple.driver.AirPort.Brcm4360 is a big hog for me, but I can't do much about it if I want to use wifi.

One of the suggestions I received was to look up all non-Apple kexts are taking up memory by piping the above to grep -v com.apple.  It's possible that some non-Apple programs are using up your resources.  You should be able to remove those without breaking anything.

The age old solution of course is to restart your computer.  Sometimes that's all it takes to set processes back to their normal levels of CPU usage.