From owner-freebsd-hackers  Tue Apr  1 15:47:26 1997
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To: Robert Withrow <witr@rwwa.com>
cc: hackers@freebsd.org
Subject: Re: Can anyone here help these people? 
In-reply-to: Your message of "Tue, 01 Apr 1997 17:16:05 EST."
             <199704012216.RAA04747@spooky.rwwa.com> 
From: David Greenman <dg@root.com>
Reply-To: dg@root.com
Date: Tue, 01 Apr 1997 15:48:34 -0800
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>There is an order of magnitude difference in the performance of
>postgress between FreeBSD and Linux, with FreeBSD loosing.  Here
>is a ktrace that shows the problem...
...
>Here it's almost 1/5 of a second between getting the "Pblank" (I don't
>know what that signifies, maybe it's a clue to something.) after the

   The problem is caused by the Nagle Congestion Avoidence algorithm. See
pages 269-270 of TCP/IP Illustrated, Volume 1. The problem can be eliminated
by setting the TCP_NODELAY socket option.

-DG

David Greenman
Core-team/Principal Architect, The FreeBSD Project