From: Eric Dumazet <eric.dumazet@gmail.com>
To: David Miller <davem@redhat.com>
Cc: netdev@vger.kernel.org
Subject: Re: [PATCH net-net] net: loopback: set default mtu to 64K
Date: Mon, 24 Sep 2012 22:33:16 +0200 [thread overview]
Message-ID: <1348518796.26828.1651.camel@edumazet-glaptop> (raw)
In-Reply-To: <20120924.162442.1381532664983403691.davem@redhat.com>
On Mon, 2012-09-24 at 16:24 -0400, David Miller wrote:
> 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.
the biggest increase is with
netperf -- -m 63K
I reach 50000 Mbytes/second
next prev parent reply other threads:[~2012-09-24 20:33 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-24 8:28 [PATCH net-net] net: loopback: set default mtu to 64K Eric Dumazet
2012-09-24 20:24 ` David Miller
2012-09-24 20:33 ` Eric Dumazet [this message]
2012-09-24 20:38 ` David Miller
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