[dpdk-dev] [PATCH v2 2/2] gro: support VxLAN GRO

[Hu, Jiayu]

Hi Stephen,

> -----Original Message-----
> From: Stephen Hemminger [mailto:stephen at networkplumber.org]
> Sent: Thursday, December 14, 2017 11:03 AM
> To: Hu, Jiayu <jiayu.hu at intel.com>
> Cc: dev at dpdk.org; Ananyev, Konstantin <konstantin.ananyev at intel.com>;
> Tan, Jianfeng <jianfeng.tan at intel.com>; Chen, Junjie J
> <junjie.j.chen at intel.com>; Mcnamara, John <john.mcnamara at intel.com>;
> matvejchikov at gmail.com
> Subject: Re: [PATCH v2 2/2] gro: support VxLAN GRO
> 
> On Thu, 14 Dec 2017 10:49:39 +0800
> Jiayu Hu <jiayu.hu at intel.com> wrote:
> 
> > +	/* Don't merge packets whose outer DF bits are different. */
> > +	if (item->outer_is_atomic ^ outer_is_atomic)
> 
> unlikely() here?

Agree. Add it in the next version.

> 
> > +		return 0;
> > +
> > +	l2_offset = pkt->outer_l2_len + pkt->outer_l3_len;
> > +	cmp = check_seq_option(&item->inner_item, tcp_hdr, sent_seq,
> ip_id,
> > +			tcp_hl, tcp_dl, l2_offset, is_atomic);
> > +	if ((cmp == 1) && (outer_is_atomic || (outer_ip_id ==
> > +					item->outer_ip_id +
> > +					item->inner_item.nb_merged)))
> 
> More readable if you break the line at the ||

Exactly, I will change it in the next version.

> 
> > +		/* Append the packet. */
> > +		return 1;
> > +	else if ((cmp == -1) && (outer_is_atomic || (outer_ip_id + 1 ==
> > +					item->outer_ip_id)))
> 
> else unecessary after return. Similar line break for readabilty.

Correctly, I will change it.

> 
> > +		/* Prepend the packet. */
> > +		return -1;
> > +	else
> > +		return 0;
> > +}
> > +
> 
> maybe?
> 	if (cmp == 1) {
> 		if (outer_is_atomic ||
> 		    outer_ip_id == item->outer_ip_id + item-
> >inner_item.nb_merged)
> 			return 1;
> 	} else if (cmp == -1) {
> 		if (uter_is_atomic || outer_ip_id + 1 == item->outer_ip_id)
> 			return -1;
> 	}
> 	return 0;
> 

The reason to replace "if ((cmp == 1) && (outer_is_atomic ...))" with two if statements is
for readability?

But will two if statements make codes less efficient?

Thanks,
Jiayu