From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@redhat.com>
Subject: Re: [PATCH net-net] net: loopback: set default mtu to 64K
Date: Mon, 24 Sep 2012 16:24:42 -0400 (EDT)
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From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Mon, 24 Sep 2012 10:28:59 +0200

> From: Eric Dumazet <edumazet@google.com>
> 
> loopback current mtu of 16436 bytes allows no more than 3 MSS TCP
> segments per frame, or 48 Kbytes. Changing mtu to 64K allows TCP
> stack to build large frames and significantly reduces stack overhead.
> 
> Performance boost on bulk TCP transferts can be up to 30 %, partly
> because we now have one ACK message for two 64KB segments, and a lower
> probability of hitting /proc/sys/net/ipv4/tcp_reordering default limit.
> 
> Signed-off-by: Eric Dumazet <edumazet@google.com>

This gives a nice %13 improvement on my SPARC-T4 box as well.

Applied, thanks Eric.