Re: [PATCH net-next-2.6] gro: __napi_gro_receive() optimizations

[David Miller <davem@davemloft.net>]

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 25 Aug 2010 22:33:51 +0200

> @@ -102,19 +102,9 @@ vlan_gro_common(struct napi_struct *napi, struct vlan_group *grp,
>  	if (vlan_dev)
>  		skb->dev = vlan_dev;
>  	else if (vlan_id)
> -		goto drop;
> -
> -	for (p = napi->gro_list; p; p = p->next) {
> -		NAPI_GRO_CB(p)->same_flow =
> -			p->dev == skb->dev && !compare_ether_header(
> -				skb_mac_header(p), skb_gro_mac_header(skb));
> -		NAPI_GRO_CB(p)->flush = 0;
> -	}
> -
> -	return dev_gro_receive(napi, skb);
> +		return GRO_DROP;
>  
> -drop:
> -	return GRO_DROP;
> +	return __napi_gro_receive(napi, skb);

I was looking at this the other day and considering something
similar but I didn't do it because this now makes the call chain
deeper.

And that can make a performance difference.

I don't want to add this hunk unless some GRO perf regression tests
are done.

Thanks.