I have a preliminary discussion with junsu and we are still confused with the idlepoll livelock issue.

http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/kern/kern_poll.c

With some specific configuration, enabling polling in idle loop would exhibit a strange livelock. CPU will soon be 100% consumed when there’s networking communication.

I have a preliminary patch against the issue. I will test it soon.