Subject: Re: [RFC PATCH v3 net-next] Documentation: devlink: Add devlink-sd

From: Simon Horman <[email-masked]>
Date: Mon, 29 Jan 2024 10:56:04 +0000

On Thu, Jan 25, 2024 at 02:36:17PM -0800, William Tu wrote:
> Add devlink-sd, shared descriptor, documentation. The devlink-sd
> mechanism is targeted for configuration of the shared rx descriptors
> that server as a descriptor pool for ethernet reprsentors (reps)
> to better utilize memory. Following operations are provided:
>  * add/delete a shared descriptor pool
>  * Configure the pool's properties
>  * Bind/unbind a representor's rx channel to a descriptor pool
> 
> Propose new devlink objects because existing solutions below do
> not fit our use cases:
> 1) devlink params: Need to add many new params to support
>    the shared descriptor pool. It doesn't seem to be a good idea.
> 2) devlink-sb (shared buffer): very similar to the API proposed in
>    this patch, but devlink-sb is used in ASIC hardware switch buffer
>    and switch's port. Here the use case is switchdev mode with
>    reprensentor ports and its rx queues.
> 
> Signed-off-by: William Tu <[email-masked]>
> Change-Id: I1de0d9544ff8371955c6976b2d301b1630023100
> ---
> v3: read again myself and explain NAPI context and descriptor pool
> v2: work on Jiri's feedback
> - use more consistent device name, p0, pf0vf0, etc
> - several grammar and spelling errors
> - several changes to devlink sd api
>   - remove hex, remove sd show, make output 1:1 mapping, use
>   count instead of size, use "add" instead of "create"
>   - remove the use of "we"
> - remove the "default" and introduce "shared-descs" in switchdev mode
> - make description more consistent with definitions in ethtool,
> such as ring, channel, queue.
> ---
>  .../networking/devlink/devlink-sd.rst         | 296 ++++++++++++++++++
>  1 file changed, 296 insertions(+)
>  create mode 100644 Documentation/networking/devlink/devlink-sd.rst

Hi William,

a minor nit from my side:
I think that devlink-sd should be added to the toc in index.rst.

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