From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [PATCH net-next 3/3] ipv4: gre: add GRO capability
Date: Thu, 27 Sep 2012 20:19:50 +0200
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Cc: David Miller <davem@davemloft.net>, netdev <netdev@vger.kernel.org>
To: Jesse Gross <jesse@nicira.com>
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On Thu, 2012-09-27 at 20:08 +0200, Eric Dumazet wrote:

> 
> This sounds not feasible with all kind of tunnels, for example IPIP
> tunnels, or UDP encapsulation, at least with current stack (not OVS)
> 
> Also note that pushing earlier means forcing the checksumming earlier
> and it consumes a lot of cpu cycles. Hopefully NIC will help us in the
> future.
> 
> Using a napi_struct permits to eventually have separate cpus, and things
> like RPS/RSS to split the load.

Also please note that my implementation doesnt bypass first IP stack
traversal (and firewalling if any), so its changing nothing in term
of existing setups.

So packets that should be forwarded will stay as they are (no tunnels
decapsulation/recapsulation)

Doing this in the generic GRO layer sounds a bit difficult.