freebsd4.11 patch for nfs over tcp

[rick at snowhite.cis.uoguelph.ca]

> I always point people at "Rethinking the TCP Nagle Algorithm" (Mogul &
> Minshall) when this comes up. It's a nice readable paper on the issues
> and some propsed solutions.

And, yes, it does cause performance problems for NFS. If an RPC is in the
send queue, it delays sending the request. For the case I was testing
that normally takes 5 seconds, it took about 3 minutes. You could
watch the server's disk led "blink <wait a bit>, blink...".

As an historical note, it was Tom Talpey who suggested turning off the
Nagle algorithm to me in 1989, when I was observing slow NFS over TCP on
a MicroVAXII (now, that means REALLY SLOOWWWW).

rick