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

From: Eric Dumazet
Date: Tue Jun 06 2023 - 03:25:46 EST


On Thu, Jun 1, 2023 at 6:14 PM 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.
>
> 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>

Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>