From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net-next 00/13] nfp: abm: track all Qdiscs Date: Wed, 14 Nov 2018 08:53:44 -0800 (PST) Message-ID: <20181114.085344.1817834028476838683.davem@davemloft.net> References: <20181112225819.29823-1-jakub.kicinski@netronome.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: oss-drivers@netronome.com, netdev@vger.kernel.org, jiri@resnulli.us, xiyou.wangcong@gmail.com, jhs@mojatatu.com To: jakub.kicinski@netronome.com Return-path: Received: from shards.monkeyblade.net ([23.128.96.9]:47158 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728085AbeKOC5p (ORCPT ); Wed, 14 Nov 2018 21:57:45 -0500 In-Reply-To: <20181112225819.29823-1-jakub.kicinski@netronome.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Jakub Kicinski 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.