[PATCH] doc: add link to mbuf layout history

[Morten Brørup]

> From: Thomas Monjalon [mailto:thomas at monjalon.net]
> Sent: Tuesday, 7 April 2026 10.06
> 
> In order to illustrate how mbuf is kept small,
> add a link to a page showing the mbuf layout for each version.
> 
> Signed-off-by: Thomas Monjalon <thomas at monjalon.net>
> ---
>  doc/guides/prog_guide/mbuf_lib.rst | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/doc/guides/prog_guide/mbuf_lib.rst
> b/doc/guides/prog_guide/mbuf_lib.rst
> index 382bfbdca4..97f8e72356 100644
> --- a/doc/guides/prog_guide/mbuf_lib.rst
> +++ b/doc/guides/prog_guide/mbuf_lib.rst
> @@ -8,11 +8,12 @@ The Packet (MBuf) library provides the ability to
> allocate and free buffers (mbu
>  that may be used by the DPDK application to store message buffers.
>  The message buffers are stored in a mempool, using the
> :doc:`mempool_lib`.
> 
> -A rte_mbuf struct generally carries network packet buffers, but it can
> actually
> -be any data (control data, events, ...).
> -The rte_mbuf header structure is kept as small as possible and
> currently uses
> -just two cache lines, with the most frequently used fields being on
> the first
> -of the two cache lines.
> +A ``struct rte_mbuf`` generally carries network packet buffers,
> +but it can actually be any data (control data, events, etc).
> +The ``rte_mbuf`` header structure is
> +`kept as small as possible
> <https://doc.dpdk.org/struct/mbuf/history.html>`_
> +and currently uses just two 64-byte cache lines,
> +with the most frequently used fields being on the first of the two
> cache lines.
> 
>  Design of Packet Buffers
>  ------------------------
> --
> 2.53.0

Hadn't noticed that illustration before, so good idea linking to it here.

Acked-by: Morten Brørup <mb at smartsharesystems.com>