RE: [PATCH net-next 08/12] r8152: support TSO

From: David Laight
Date: Tue Mar 04 2014 - 10:14:41 EST


From: Eric Dumazet
> On Tue, 2014-03-04 at 14:35 +0000, David Laight wrote:
>
> > Does that mean you are splitting the 64k 'ethernet packet' from TCP
> > is software? I've looked at the ax88179 where the hardware can do it.
> >
> > Is there really a gain doing segmentation here if you have to do the
> > extra data copy?
>
> There is no 'extra' copy.
>
> There is _already_ a copy, so what's the deal of doing this copy in a SG
> enabled way ?

Ok.

But there is one more copy than for a normal ethernet chipset which
can use multiple ring entries to send the MAC+IP+TCP headers from a
different buffer to the TCP userdata.

David

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