One of the things that I just thought about is, that we can probably have openvpn call sched_setscheduler() using something like SCHED_RR. This might be of more use than just renicing the process. Considering we are in a fairly performance critical path for a userspace process this would seem to make sense. Not sure how to deal with SCHED_RR wrt to threads though. On my systems I haven't noticed much of a difference, when doing this, but my systems aren't heavily loaded either.
Thoughts, comments? -Aaron