On 12/07/18 21:10, Or Gerlitz wrote:
> On Wed, Jul 11, 2018 at 11:06 PM, Jesper Dangaard Brouer
> <bro...@redhat.com> wrote:
>> One reason I didn't "just" send a patch, is that Edward so-fare only
>> implemented netif_receive_skb_list() and not napi_gro_receive_list().
> sfc does't support gro?! doesn't make sense.. Edward?
sfc has a flag EFX_RX_PKT_TCP set according to bits in the RX event, we
call napi_{get,gro}_frags() (via efx_rx_packet_gro()) for TCP packets and
netif_receive_skb() (or now the list handling) (via efx_rx_deliver()) for
non-TCP packets. So we avoid the GRO overhead for non-TCP workloads.
> Same TCP performance
>
> with GRO and no rx-batching
>
> or
>
> without GRO and yes rx-batching
>
> is by far not intuitive result
I'm also surprised by this. If I can find the time I'll try to do similar
experiments on sfc.
Jesper, are the CPU utilisations similar in both cases? You're sure your
stream isn't TX-limited?
-Ed
