Insanely high kernel RAM usage (over 9GB) in Mavericks

Solution 1:

A reboot seems to clear my system that experiences similar RAM allocation for the kernel, but it will climb up again over time. I have chatted with Apple support and they suggested an SMC reset, which I did along with a PRAM reset and so far, it seems to be under control. It's hovered just under 1GB as I've been working, and watched it dip down a couple of times when some apps were idle.

Long term, resetting SMC & PRAM didn't affect the memory allocation and I've tracked the insane memory usage to the "installd" process.

Open Activity Monitor and FORCE QUIT that process and watch the kernel usage drop down to normal levels. Unfortunately, you have to do this after every startup as it appears to be leaking memory on builds lower than 10.9.1 and 13B42.

Solution 2:

Fontbook was the cause for me, running at 3.9GB and kernel_task at 9GB. Force quitting fontbook caused the kernel_task to drop to 1.12GB and give my fan a break.