Subject: Re: [PATCH net-next v2 1/8] net: gro: decouple GRO from the NAPI layer

From: Jakub Kicinski <[email-masked]>
Date: Mon, 13 Jan 2025 13:01:04 -0800

On Mon, 13 Jan 2025 14:50:02 +0100 Alexander Lobakin wrote:
> From: Paolo Abeni <[email-masked]>
> Date: Thu, 9 Jan 2025 15:24:16 +0100
> 
> > On 1/7/25 4:29 PM, Alexander Lobakin wrote:  
> >> @@ -623,21 +622,21 @@ static gro_result_t napi_skb_finish(struct napi_struct *napi,
> >>  	return ret;
> >>  }
> >>  
> >> -gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
> >> +gro_result_t gro_receive_skb(struct gro_node *gro, struct sk_buff *skb)
> >>  {
> >>  	gro_result_t ret;
> >>  
> >> -	skb_mark_napi_id(skb, napi);
> >> +	__skb_mark_napi_id(skb, gro->napi_id);  
> > 
> > Is this the only place where gro->napi_id is needed? If so, what about
> > moving skb_mark_napi_id() in napi_gro_receive() and remove such field?  
> 
> Yes, only here. I thought of this, too. But this will increase the
> object code of each napi_gro_receive() caller as it's now inline. So I
> stopped on this one.
> What do you think?

What if we make napi_gro_receive() a real function (not inline) 
and tail call gro_receive_skb()? Is the compiler not clever 
enough too optimize that?

Very nice work in general, the napi_id is gro sticks out..