# Re: \[PATCH RFC v3 2/5\] net: Add NETIF\_F\_GRO\_LIST feature

- From: Steffen Klassert \<steffen.klassert@secunet.com\>
- Date: 2019-09-19 09:24:51 
- List: netdev
- Page: https://ratatoskr.run/netdev/2019/09/11147946
- Thread: https://ratatoskr.run/netdev/2019/09/11147879/t.md

```text
On Wed, Sep 18, 2019 at 12:10:31PM -0400, Willem de Bruijn wrote:
> On Wed, Sep 18, 2019 at 3:25 AM Steffen Klassert
> [ref] wrote:
> >
> > This adds a new NETIF_F_GRO_LIST feature flag. I will be used
> > to configure listfyed GRO what will be implemented with some
> > followup paches.
> 
> This should probably simultaneously introduce SKB_GSO_FRAGLIST as well
> as a BUILD_BUG_ON in net_gso_ok.

Yes, good point. I'll also rename NETIF_F_GRO_LIST to NETIF_F_GRO_FRAGLIST
and add NETIF_F_GSO_FRAGLIST what is currently missing.

> 
> Please also in the commit describe the constraints of skbs that have
> this type. If I'm not mistaken, an skb with either gso_size linear
> data or one gso_sized frag, followed by a frag_list of the same. With
> the exception of the last frag_list member, whose mss may be less than
> gso_size. This will help when reasoning about all the types of skbs we
> may see at segmentation, as we recently had to do [1]

We don't use skb_segment(), so I think we don't have this constraint.

> 
> Minor nit: I think it's listified, not listifyed.

I think neither of both words really exist :)
I'll rename it to fraglist GRO.

```