Re: [PATCH v8 net-next 5/5] tcp: reorganize tcp_sock fast path variables

[Eric Dumazet <edumazet@google.com>]

On Wed, Nov 29, 2023 at 8:28 AM Coco Li <lixiaoyan@google.com> wrote:
>
> The variables are organized according in the following way:
>
> - TX read-mostly hotpath cache lines
> - TXRX read-mostly hotpath cache lines
> - RX read-mostly hotpath cache lines
> - TX read-write hotpath cache line
> - TXRX read-write hotpath cache line
> - RX read-write hotpath cache line
>
> Fastpath cachelines end after rcvq_space.
>
> Cache line boundaries are enforced only between read-mostly and
> read-write. That is, if read-mostly tx cachelines bleed into
> read-mostly txrx cachelines, we do not care. We care about the
> boundaries between read and write cachelines because we want
> to prevent false sharing.
>
> Fast path variables span cache lines before change: 12
> Fast path variables span cache lines after change: 8
>
> Suggested-by: Eric Dumazet <edumazet@google.com>
> Reviewed-by: Wei Wang <weiwan@google.com>
> Reviewed-by: David Ahern <dsahern@kernel.org>
> Signed-off-by: Coco Li <lixiaoyan@google.com>


Reviewed-by: Eric Dumazet <edumazet@google.com>

Thanks !