Re: [PATCH net-next 00/13] nfp: abm: track all Qdiscs

[David Miller <davem@davemloft.net>]

From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Mon, 12 Nov 2018 14:58:06 -0800

> Our Qdisc offload so far has been very simplistic.  We held
> and array of marking thresholds and statistics sized to the
> number of PF queues.  This was sufficient since the only
> configuration we supported was single layer of RED Qdiscs
> (on top of MQ or not, but MQ isn't really about queuing).
> 
> As we move to add more Qdiscs it's time to actually try to
> track the full Qdisc hierarchy.  This allows us to make sure
> our offloaded configuration reflects the SW path better.
> We add graft notifications to MQ and RED (PRIO already sends
> them) to allow drivers offloading those to learn how Qdiscs
> are linked.  MQ graft gives us the obvious advantage of being
> able to track when Qdiscs are shared or moved.  It seems
> unlikely HW would offload RED's child Qdiscs but since the
> behaviour would change based on linked child we should
> stop offloading REDs with modified child.  RED will also
> handle the child differently during reconfig when limit
> parameter is set - so we have to inform the drivers about
> the limit, and have them reset the child state when
> appropriate.
> 
> The NFP driver will now allocate a structure to track each
> Qdisc and link it to its children.  We will also maintain
> a shadow copy of threshold settings - to save device writes
> and make it easier to apply defaults when config is
> re-evaluated.

Series applied, thanks.