Re: [PATCH net-next 3/3] ipv4: gre: add GRO capability

Jesse Gross
2012-09-27T17:52:34Z

On Thu, Sep 27, 2012 at 5:48 AM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> From: Eric Dumazet <edumazet@google.com>
>
> Add GRO capability to IPv4 GRE tunnels, using the gro_cells
> infrastructure.
>
> Tested using IPv4 and IPv6 TCP traffic inside this tunnel, and
> checking GRO is building large packets.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>

When I was thinking about doing this, my original plan was to handle
GRO/GSO by extending the current handlers to be able to look inside
GRE and then loop around to process the inner packet (similar to what
is done today with skb_flow_dissect() for RPS). Is there a reason to
do it in the device?

Pushing it earlier/later in the stack obviously increases the benefit
and it will also be more compatible with the forthcoming OVS tunneling
hooks, which will be flow based and therefore won't have a device.

Also, the next generation of NICs will support this type of thing in
hardware so putting the software versions very close to the NIC will
give us a more similar abstraction.