From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Pirko Subject: Re: [PATCH net-next v2] net: sched: red: don't reset the backlog on every stat dump Date: Wed, 17 Jan 2018 11:50:43 +0100 Message-ID: <20180117105043.GB2114@nanopsycho> References: <20180115040126.14190-1-jakub.kicinski@netronome.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: davem@davemloft.net, Nogah Frankel , netdev@vger.kernel.org, oss-drivers@netronome.com, xiyou.wangcong@gmail.com, edumazet@google.com, Yuval Mintz To: Jakub Kicinski Return-path: Received: from mail-wr0-f195.google.com ([209.85.128.195]:34675 "EHLO mail-wr0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750815AbeAQKuo (ORCPT ); Wed, 17 Jan 2018 05:50:44 -0500 Received: by mail-wr0-f195.google.com with SMTP id 36so18379048wrh.1 for ; Wed, 17 Jan 2018 02:50:44 -0800 (PST) Content-Disposition: inline In-Reply-To: <20180115040126.14190-1-jakub.kicinski@netronome.com> Sender: netdev-owner@vger.kernel.org List-ID: Mon, Jan 15, 2018 at 05:01:26AM CET, jakub.kicinski@netronome.com wrote: >Commit 0dfb33a0d7e2 ("sch_red: report backlog information") copied >child's backlog into RED's backlog. Back then RED did not maintain >its own backlog counts. This has changed after commit 2ccccf5fb43f >("net_sched: update hierarchical backlog too") and commit d7f4f332f082 >("sch_red: update backlog as well"). Copying is no longer necessary. > >Tested: > >$ tc -s qdisc show dev veth0 >qdisc red 1: root refcnt 2 limit 400000b min 30000b max 30000b ecn > Sent 20942 bytes 221 pkt (dropped 0, overlimits 0 requeues 0) > backlog 1260b 14p requeues 14 > marked 0 early 0 pdrop 0 other 0 >qdisc tbf 2: parent 1: rate 1Kbit burst 15000b lat 3585.0s > Sent 20942 bytes 221 pkt (dropped 0, overlimits 138 requeues 0) > backlog 1260b 14p requeues 14 > >Recently RED offload was added. We need to make sure drivers don't >depend on resetting the stats. This means backlog should be treated >like any other statistic: > > total_stat = new_hw_stat - prev_hw_stat; > >Adjust mlxsw. > >Signed-off-by: Jakub Kicinski Acked-by: Jiri Pirko