From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pb0-x22d.google.com (mail-pb0-x22d.google.com [IPv6:2607:f8b0:400e:c01::22d]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 7FC4321F21C for ; Sun, 23 Mar 2014 12:27:42 -0700 (PDT) Received: by mail-pb0-f45.google.com with SMTP id uo5so4525550pbc.18 for ; Sun, 23 Mar 2014 12:27:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:subject:from:to:cc:date:in-reply-to:references :content-type:content-transfer-encoding:mime-version; bh=aCbrrjzl65URGLp3sOC7x2Dn1wLXoKo5IAuWs+RJtkA=; b=XDspB++hYxBLL9Lcn+lchyyxNzHhbiKfdSoAOjdoF3o8Xk9jUpoOygCCBk4ny2ttee G0+c3a7hVnwEURmyF55rl7qEQsLpY4LD9GlTUsEJlzqbBQrEudXpQqflh3r88EjbDR8g V9pVE5w7VxvbYdbKX+OoSVxhwmL3joo4Md2WA9Uu4T7NEv/GAlxSkslLm16HvKhAM6Yq i1IO0aF2XeKY+pegSJYOCq9He6Q2wFUcUzTWSG2ccP3yAZoyAxhhejZi2D9gQXBx9/aN bmIWKFwKzISNSlUkmLA2yhdq2bpg0zrrmUF3Rf1s1/nHvYnT7PlNggPkvVxH62yIAtGe a0pw== X-Received: by 10.68.215.40 with SMTP id of8mr66292238pbc.15.1395602861815; Sun, 23 Mar 2014 12:27:41 -0700 (PDT) Received: from [172.19.250.181] ([172.19.250.181]) by mx.google.com with ESMTPSA id kc9sm26712704pbc.25.2014.03.23.12.27.40 for (version=SSLv3 cipher=RC4-SHA bits=128/128); Sun, 23 Mar 2014 12:27:41 -0700 (PDT) Message-ID: <1395602859.9117.19.camel@edumazet-glaptop2.roam.corp.google.com> From: Eric Dumazet To: Dave Taht Date: Sun, 23 Mar 2014 12:27:39 -0700 In-Reply-To: References: <20140318145221.GA31327@sesse.net> <07BD4518-2A7E-4F43-8978-791E3B2BDA2A@cisco.com> <87eh1wc05c.fsf@toke.dk> <87a9ckbz1q.fsf@toke.dk> <1395358884.9114.102.camel@edumazet-glaptop2.roam.corp.google.com> <1395414379.6441.17.camel@edumazet-glaptop2.roam.corp.google.com> <1395424311.8701.20.camel@edumazet-glaptop2.roam.corp.google.com> <1395439222.9117.3.camel@edumazet-glaptop2.roam.corp.google.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Cc: "Steinar H. Gunderson" , bloat Subject: Re: [Bloat] AQM creeping into L2 equipment X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 23 Mar 2014 19:27:44 -0000 On Fri, 2014-03-21 at 22:13 +0000, Dave Taht wrote: > Are you ready to make sch_fq the default in 3.15? sch_fq depends on ktime_get(), so it is a no go if you have clocksource using hpet. pfifo_fast doesn't have such issues. Another issue is TCP CUBIC Hystart 'ACK TRAIN' detection that triggers early, since goal of TSO autosizing + FQ/pacing is to get ACK clocking every ms. By design, it tends to get ACK trains, way before the cwnd might reach BDP.