Re: [PATCH net v2 08/11] docs: net: document netdev notifier expectations

[Jakub Kicinski <kuba@kernel.org>]

On Thu, 27 Mar 2025 06:56:56 -0700 Stanislav Fomichev wrote:
> We don't have a consistent state yet, but document where we think
> we are and where we wanna be.

Thanks for adding the doc!

> +Notifiers and netdev instance lock
> +==================================
> +
> +For device drivers that implement shaping or queue management APIs,
> +some of the notifiers (``enum netdev_cmd``) are running under the netdev
> +instance lock.
> +
> +Currently only the following notifiers are running under the instance lock:

I'd repeat again here:

... for devices with locked ops:

> +* ``NETDEV_REGISTER``
> +* ``NETDEV_UP``
> +* ``NETDEV_UNREGISTER``

Can I ask the obvious question - anything specific that's hard in also
taking it in DOWN or just no time to investigate? Symmetry would be
great.

> +There are no clear expectations for the remaining notifiers. Notifiers not on
> +the list may run with or without the instance lock, potentially even invoking
> +the same notifier type with and without the lock from different code paths.
> +The goal is to eventually ensure that all (or most, with a few documented
> +exceptions) notifiers run under the instance lock.