Re: [PATCH v9 bpf-next 01/14] net: skbuff: add data_len field to skb_shared_info

Alexander Duyck
2021-06-28T19:58:50Z

On Mon, Jun 14, 2021 at 5:50 AM Lorenzo Bianconi <lorenzo@kernel.org> wrote:
>
> data_len field will be used for paged frame len for xdp_buff/xdp_frame.
> This is a preliminary patch to properly support xdp-multibuff
>
> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> ---
> include/linux/skbuff.h | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
> index dbf820a50a39..332ec56c200d 100644
> --- a/include/linux/skbuff.h
> +++ b/include/linux/skbuff.h
> @@ -522,7 +522,10 @@ struct skb_shared_info {
> struct sk_buff *frag_list;
> struct skb_shared_hwtstamps hwtstamps;
> unsigned int gso_type;
> - u32 tskey;
> + union {
> + u32 tskey;
> + u32 data_len;
> + };
>

Rather than use the tskey field why not repurpose the gso_size field?
I would think in the XDP paths that the gso fields would be unused
since LRO and HW_GRO would be incompatible with XDP anyway.