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	id AA20823; Fri, 16 Feb 1996 14:03:41 -0500
Date: Fri, 16 Feb 1996 14:03:41 -0500
From: "Garrett A. Wollman" <wollman@lcs.mit.edu>
Message-Id: <9602161903.AA20823@halloran-eldar.lcs.mit.edu>
To: Conny Larsson <conny@teligent.se>
Cc: questions@freebsd.org
Subject: TCP/IP performance - urgent!
In-Reply-To: <Pine.BSF.3.91.960216194105.9578A-100000@kvaser.teligent.se>
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<<On Fri, 16 Feb 1996 20:02:45 +0100 (MET), Conny Larsson <conny@teligent.se> said:

>  In short, I get substantial performance degradation using TCP/IP 
> stream sockets when the size of the data being sent/received is within 
> certain intervals. 

You are probably experiencing performance degradation due to
interference between the mbuf and socket buffer layers.  In
/sys/kern/uipc_socket2.c, look for the line:

        sb->sb_mbmax = min(cc * 2, sb_max);

...and change the `* 2' factor to something more reasonable (like `*
8').  That should (if this is the source of your problem) cause
transfers to run faster, at the expense of more memory usage.

-GAWollman

--
Garrett A. Wollman   | Shashish is simple, it's discreet, it's brief. ... 
wollman@lcs.mit.edu  | Shashish is the bonding of hearts in spite of distance.
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