From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Hemminger <shemminger@vyatta.com>
Subject: Re: [PATCH v2] ipv4: Early TCP socket demux.
Date: Wed, 20 Jun 2012 14:04:54 -0700
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To: David Miller <davem@davemloft.net>
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On Wed, 20 Jun 2012 14:01:21 -0700 (PDT)
David Miller <davem@davemloft.net> wrote:

> From: Eric Dumazet <eric.dumazet@gmail.com>
> Date: Wed, 20 Jun 2012 20:40:04 +0200
> 
> > If someone wants to tune its linux router, he probably already disables
> > GRO because of various issues with too big packets.
> > 
> > GRO adds a significant cost to forwarding path.
> 
> No, Ben is right Eric.  GRO decreases the costs, because it means we
> only need to make one forwarding/netfilter/classification decision for
> N packets instead of 1.

GRO is also important for routers that interact with VM's.
It helps reduce the per-packet wakeup of the guest VM's.