From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lb0-x229.google.com (mail-lb0-x229.google.com [IPv6:2a00:1450:4010:c04::229]) (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 4029221F552; Tue, 16 Jun 2015 22:49:25 -0700 (PDT) Received: by lbbti3 with SMTP id ti3so24162331lbb.1; Tue, 16 Jun 2015 22:49:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:content-type:content-transfer-encoding:subject:message-id:date :to:mime-version; bh=213tgucFlCpjK93tYDGkk9nnHc2A5VLJUWBpbFJcgdQ=; b=yCZTMsoL0zRk6Jq7+MixCxARIPeIJq3SGEjpLNI4vhKK2LsSRXDP5ICGP1fN1RnqaA kflTMsB3Vku/avdKJMwPti2Ydw6IEUTRGkOdkD6rrmaw2DLmJeprAS/SJwtrgsZtQJid zU9y1bsCXe1GrGtJsFIOd8HouGFvTUUO+bYoELT2V6am6WhRNRDwQW6IqdvUvFRBf1C5 foQIKZyjyNLE+aoNwe03/em9sRL/tVhNXVm9kX6MwVfgOgEuzoFCHUl8TdA5AbKw/oFg IJWIXnal7yWqAuixm2nngr8s6b4sNQW96HkYLdEIGTq7Z9fl5NGbiaTnmvr4K6xyDbNs WJ2Q== X-Received: by 10.112.168.165 with SMTP id zx5mr5774525lbb.111.1434520163333; Tue, 16 Jun 2015 22:49:23 -0700 (PDT) Received: from bass.home.chromatix.fi (87-93-133-238.bb.dnainternet.fi. [87.93.133.238]) by mx.google.com with ESMTPSA id ap9sm723386lbd.21.2015.06.16.22.49.18 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 16 Jun 2015 22:49:22 -0700 (PDT) From: Jonathan Morton Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Message-Id: <00270BE3-4932-4294-8917-8A9C2B462FCF@gmail.com> Date: Wed, 17 Jun 2015 08:49:14 +0300 To: cake@lists.bufferbloat.net, codel@lists.bufferbloat.net, bloat Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2098\)) X-Mailer: Apple Mail (2.2098) Subject: [Codel] Today's cake X-BeenThere: codel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: CoDel AQM discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 17 Jun 2015 05:49:54 -0000 I just put in three quite small tweaks to cake: 1) Codel now has a saturating increment for count, rather than a = wrapping one. 2) The active flow counter is now an atomic-access variable. This is = really just an abundance of caution. 3) The overload drop routine should now be somewhat more efficient in = most cases, since it iterates over the active flows rather than the = entire array. I haven=E2=80=99t measured how much of a difference it = makes in practice, but it should be positive. Point 1 turns out to matter rather a lot under unresponsive loads, given = that count is only 16 bits. The =E2=80=9C50 up 1 down asymmetric=E2=80=9D test now produces the = desired results for the download stream *without* the need to prioritise = the acks; Codel now reaches a steady-ish state where it drops enough of = them to keep everything moving, and this leaves more bandwidth in the up = direction for the 50 streams. The version of that test with a prioritised download stream reveals that = quite a lot of drops (as well as marks) are still occurring in the 50 = streams. This, to my mind, is a sign of too much aggression in the = switch from marking to dropping, but I need to work out the numbers to = be more confident about adjusting that. - Jonathan Morton