FYI:
If you're using John's wireless-testing.git then you'll see that your
system's load goes through the roof despite no activity. There's an
upstream patch now in Linus' repo that fixes an accounting bug in the
rcu code that will solve this:
https://github.com/mirrors/linux-2.6/commit/d72bce0e67e8afc6eb959f656013cbb577426f1e.patch
I think it's harmless, but might confuse you as it did me. It should
be fixed whenever John next does a pull and gets the above patch.
Dan