Re: [PATCH v3 1/2] gro: decrease size of CB

[Eric Dumazet]

On Mon, Mar 13, 2023 at 9:30 AM Richard Gobert <richardbgobert@xxxxxxxxx> wrote:
>
> The GRO control block (NAPI_GRO_CB) is currently at its maximum size.  This
> commit reduces its size by putting two groups of fields that are used only
> at different times into a union.
>
> Specifically, the fields frag0 and frag0_len are the fields that make up
> the frag0 optimisation mechanism, which is used during the initial parsing
> of the SKB.

Note that these fields could also be stored in some auto variable,
instead of skb.

>
> The fields last and age are used after the initial parsing, while the SKB
> is stored in the GRO list, waiting for other packets to arrive.
>
> There was one location in dev_gro_receive that modified the frag0 fields
> after setting last and age. I changed this accordingly without altering the
> code behaviour.
>
> Signed-off-by: Richard Gobert <richardbgobert@xxxxxxxxx>
> ---

SGTM, thanks.

Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>