Re: [Bugme-new] [Bug 11316] New: severe performance regression for iptables nat routing

From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Fri, 15 Aug 2008 20:32:35 +1000

loopback: Enable TSO

This patch enables TSO since the loopback device is naturally
capable of handling packets of any size.  This also means that
we won't enable GSO on lo which is good until GSO is fixed to
preserve netfilter state as netfilter treats loopback packets
in a special way.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

This, effectively, "enables" LRO on loopback.

And sure it's pretty obscure to shape, NAT, and end up forwarding
loopback received packets, but do you want to be the user trying to do
something like that and trying to find this particular patch which is
causing it to not work? :-)

I really don't know whether it's worth worrying about, I just wanted
to mention it.