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

[Jakub Kicinski <kuba@kernel.org>]

On Thu, 27 Mar 2025 12:16:13 -0700 Jakub Kicinski wrote:
> > +* ``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.

Looking at patch 4 maybe we should do the opposite. This was my
original commit msg for locking UNREGISTER:

    net: make NETDEV_UNREGISTER and instance lock more consistent
    
    The NETDEV_UNREGISTER notifier gets called under the ops lock
    when device changes namespace but not during real unregistration.
    Take it consistently, XSK tries to poke at netdev queue state
    from this notifier.

So if the only caller currently under the lock is netns change, and 
we already split that to release the lock - maybe we can make
UNREGISTER always unlocked instead?