irq cpu binding

[Adrian Chadd]

You still have to pin the nginx threads to whatever your limited set
of RSS CPUs are, or the benefits aren't really there.

I'd rather we just get librss defined in FreeBSD-HEAD and then have
nginx "know" about that for FreeBSD. It already has to know about the
linux way of doing it and it has to be conditional on it running
Linux. So it's not a big stretch to need to know about FreeBSD.

I haven't forwarded anything on to john yet, I'm busy trying to debug
the NUMA enumeration/configuration stuff i'm working on and why jhb's
patches break that for me. :)



-adrian