Multiple netgraph threads

[Alexander Motin]

Hi.

I have implemented a patch (for the HEAD) making netgraph to use several 
own threads for event queues processing instead of using single swinet. 
It should significantly improve netgraph SMP scalability on complicated 
workloads that require queueing by implementation (PPTP/L2TP) or stack 
size limitations. It works perfectly on my UP system, showing results 
close to original or even a bit better. I have no real SMP test server 
to measure real scalability, but test on HTT CPU works fine, utilizing 
both virtual cores at the predictable level.

Reviews and feedbacks are welcome.

URL: http://people.freebsd.org/~mav/netgraph.threads.patch

-- 
Alexander Motin