netisr defered - active only one thread

[Ryan Stone]

On Thu, Feb 2, 2012 at 2:09 PM, Alexander V. Chernikov
<melifaro at freebsd.org> wrote:
> As far as I understand, the only effect of setting bindthreads to 1 causes
> intr_event_bind() to bind soft netisr to appropriate CPU. Can you point me
> to ML discussion or some other info clarifying this bug?

http://lists.freebsd.org/pipermail/freebsd-hackers/2012-January/037597.html

The intended behaviour is as you describe, unfortunately subsequent
threads that are spawned in the intr process inherit the CPU affinity
of the last netisr through to be bound to a CPU.