From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] pkt_sched: fq: fix non TCP flows pacing Date: Tue, 08 Oct 2013 16:53:18 -0400 (EDT) Message-ID: <20131008.165318.1392122841162708841.davem@davemloft.net> References: <1381182269.12191.27.camel@edumazet-glaptop.roam.corp.google.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, sesse@google.com To: eric.dumazet@gmail.com Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:55304 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753469Ab3JHUxU (ORCPT ); Tue, 8 Oct 2013 16:53:20 -0400 In-Reply-To: <1381182269.12191.27.camel@edumazet-glaptop.roam.corp.google.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet Date: Mon, 07 Oct 2013 14:44:29 -0700 > From: Eric Dumazet > > Steinar reported FQ pacing was not working for UDP flows. > > It looks like the initial sk->sk_pacing_rate value of 0 was > a wrong choice. We should init it to ~0U like sk_max_pacing_rate > > Then, TCA_FQ_FLOW_DEFAULT_RATE should be removed because it makes > no real sense. (The default rate is really : ~0U) > > While debugging this issue, I realized sk_pacing_rate is shared between > transport and packet scheduler without locking / barriers : > > We should use ACCESS_ONCE() to make sure compiler wont perform > multiple loads or stores. > > Reported-by: Steinar H. Gunderson > Signed-off-by: Eric Dumazet Is this meant for net or net-next? It doesn't apply cleanly to the former.