If you would like to learn more there is a set of good links:
- https://bugzilla.redhat.com/show_bug.cgi?id=432451
- http://docs.oracle.com/cd/E24290_01/coh.371/e22838/tune_perftune.htm
- http://www.alexonlinux.com/smp-affinity-and-proper-interrupt-handling-in-linux
- http://www.alexonlinux.com/msi-x-the-right-way-to-spread-interrupt-load
- http://www.alexonlinux.com/why-interrupt-affinity-with-multiple-cores-is-not-such-a-good-thing