Re: gso: Attempt to handle mega-GRO packets

Eric Dumazet
2013-11-06T01:45:51Z

On Wed, 2013-11-06 at 09:30 +0800, Herbert Xu wrote:
> Here is a totally untested patch that tries to trivially process
> these new frags + frag_list skbs. It should actually be trivial
> to make this generate TSO packets by just adding a gso_ok check
> and short-circuit.
>
> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> index 3735fad..ec8e8bc 100644
> --- a/net/core/skbuff.c
> +++ b/net/core/skbuff.c
> @@ -2816,7 +2816,24 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features)
> hsize = len;
>
> if (!hsize && i >= nfrags) {
> - BUG_ON(fskb->len != len);
> + if (fskb->len != len) {
> + SKB_FRAG_ASSERT(fskb);
> +
> + nskb = skb_segment(fskb, features);
> +
> + err = PTR_ERR(nskb);
> + if (IS_ERR(nskb))
> + goto err;
> + err = -ENOMEM;
> +
> + if (segs)
> + tail->next = nskb;
> + else
> + segs = nskb;
> + tail = nskb;
> + while (tail->next)
> + tail = tail->next;
> + }
>
> pos += len;
> nskb = skb_clone(fskb, GFP_ATOMIC);
>
> Thanks,

Hmm, I do not think fskb has the headers in the general case.

It might work in the GRO case only.