[dpdk-dev] [PATCH v7 1/2] mbuf: support attaching external buffer to mbuf

Andrew Rybchenko arybchenko at solarflare.com
Fri Apr 27 09:22:31 CEST 2018


On 04/27/2018 03:01 AM, Yongseok Koh wrote:
> This patch introduces a new way of attaching an external buffer to a mbuf.
>
> Attaching an external buffer is quite similar to mbuf indirection in
> replacing buffer addresses and length of a mbuf, but a few differences:
>    - When an indirect mbuf is attached, refcnt of the direct mbuf would be
>      2 as long as the direct mbuf itself isn't freed after the attachment.
>      In such cases, the buffer area of a direct mbuf must be read-only. But
>      external buffer has its own refcnt and it starts from 1. Unless
>      multiple mbufs are attached to a mbuf having an external buffer, the
>      external buffer is writable.
>    - There's no need to allocate buffer from a mempool. Any buffer can be
>      attached with appropriate free callback.
>    - Smaller metadata is required to maintain shared data such as refcnt.
>
> Signed-off-by: Yongseok Koh <yskoh at mellanox.com>
> Acked-by: Konstantin Ananyev <konstantin.ananyev at intel.com>
> Acked-by: Olivier Matz <olivier.matz at 6wind.com>

Many thanks,
Acked-by: Andrew Rybchenko <arybchenko at solarflare.com>


More information about the dev mailing list