Re: [PATCH v3 net-next] net: introduce dev_set_forwarding()

Eric Dumazet
2013-11-04T05:00:55Z

On Mon, 2013-11-04 at 12:29 +0800, Herbert Xu wrote:
> On Sun, Nov 03, 2013 at 08:23:02PM -0800, Eric Dumazet wrote:
> >
> > Well, GRO adds latencies for sure.
> >
> > You seem to assume the transmit only can happen when NAPI is done, but
> > its not true. As soon as GRO fills one packet (reaches max capacity),
> > packet is delivered and forwarded, even if NAPI handler is not yet
> > complete for the flow.
>
> Have you actually measured this? The latency added by GRO is pure
> processing overhead. This is tiny when compared to the time NAPI takes
> to wait.

Please take a look at

2e71a6f8084e net: gro: selective flush of packets