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Date: Tue, 10 Oct 2023 07:52:31 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Jiri Pirko <jiri@resnulli.us>
Cc: netdev@vger.kernel.org, pabeni@redhat.com, davem@davemloft.net,
 edumazet@google.com, gal@nvidia.com
Subject: Re: [patch net-next] devlink: don't take instance lock for nested
 handle put
Message-ID: <20231010075231.322ced83@kernel.org>
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On Tue, 10 Oct 2023 09:31:20 +0200 Jiri Pirko wrote:
>> In Linux the PF is what controls the SFs, right?
>> Privileges, configuration/admin, resource control.
>> How can the parent disappear and children still exist.  
> 
> It's not like the PF instance disappears, the devlink port related to
> the SF is removed. Whan user does it, driver asks FW to shutdown the SF.
> That invokes FW flow which eventually leads to event delivered back to
> driver that removes the SF instance itself.

You understand what I'm saying tho, right?

If we can depend on the parent not disappearing before the child,
and the hierarchy is a DAG - the locking is much easier, because
parent can lock the child.

If it's only nVidia that put the control in hands of FW we shouldn't
complicate the core for y'all.