From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-x22a.google.com (mail-lf0-x22a.google.com [IPv6:2a00:1450:4010:c07::22a]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id A5AFC3B29F for ; Tue, 27 Sep 2016 14:56:57 -0400 (EDT) Received: by mail-lf0-x22a.google.com with SMTP id b71so33140036lfg.0 for ; Tue, 27 Sep 2016 11:56:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=b61Xbi1MB/17JtAdCYUZxLmdXKjqLkEVXcFxMbIwJc4=; b=oEzPIzn/Pee5PAKJLq5T8QVYgx9tt02yu0HmlEc0mcr1xjXwNBHeIFhr90cm6a6/Nq lss1ZBtgjjSEjdVLUlFN2Z6PO4B4sTAXK4G1Mk5wUeod4yHTxI2vC2+kjbcM0bWxMbhx m/qcnyK93uH3HG2HdxWpzberaYLBLNWjrkawncDasoVekPD8Bhha0E0xrwIogn9zJzaa mzxbyNL1KmHy2psFysxJ+1ODC0IqjvOiYsMOkMsr8P7pksJe7BMqoVdSZ9/SCtIIOPqL hQf8M0ZmMvD89YRfFrYieQpXtLY0TwJ2ChP+Az2BXkmRcvWV5GpCzEMddFv6cwu0Ktu4 gomg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=b61Xbi1MB/17JtAdCYUZxLmdXKjqLkEVXcFxMbIwJc4=; b=X/iIc7c0z4lta9r5rTQV3yL0zUa2NEwHP9l20AC+zm+skOJogy7xvmkrgRZDBT9N9y IvJDxMZGVSNWJHNaWDEv2SvuvL8IZsYmiLfZDNBc42b5LUxtc6BIC843DpO76wYMavEY wQ3ekrNHIgwgM5Q9W5xbCgflONe15ZolvR+8P/xKen6TeiySppHKHDS9rokMd/nCeW8Z HI4yuul3X1/kNn2oqY9hIhMKIpR5NyKDkAcnd1lhaU/pgEBLPjg/RdBG5Ik1LAv5gLtL R3eTpQd2i/YIGdoEgIYDWBWcSK8dmWac2/WpaWKecVP9EbQvo3DypZN3NmdByfY61Cfb 4Q/Q== X-Gm-Message-State: AE9vXwM2IOGMyFVGsErnd+m6ijORKiyyvsWiAKr1CeyTzEFmnHPp/pUO5N9bc1vnrt8YjA== X-Received: by 10.25.160.6 with SMTP id j6mr11521658lfe.159.1475002616363; Tue, 27 Sep 2016 11:56:56 -0700 (PDT) Received: from [192.168.100.13] (37-33-90-35.bb.dnainternet.fi. [37.33.90.35]) by smtp.gmail.com with ESMTPSA id u134sm371701lja.18.2016.09.27.11.56.55 (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 27 Sep 2016 11:56:55 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) From: Jonathan Morton In-Reply-To: Date: Tue, 27 Sep 2016 21:56:53 +0300 Cc: cake@lists.bufferbloat.net Content-Transfer-Encoding: quoted-printable Message-Id: <27B5A7E3-203D-468F-B487-BFFC9294D857@gmail.com> References: <32E6B0A0-6014-4510-9D97-02645F0EFDFD@gmail.com> To: Dave Taht X-Mailer: Apple Mail (2.3124) Subject: Re: [Cake] cake for net-next 4.8 X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 27 Sep 2016 18:56:57 -0000 > On 27 Sep, 2016, at 21:18, Dave Taht wrote: >=20 >> On Tue, Sep 27, 2016 at 10:52 AM, Jonathan Morton = wrote: >>=20 >>> On 25 Sep, 2016, at 21:30, Dave Taht wrote: >>>=20 >>> Judging from me tearing apart how TCP BBR works (presently) with = ecn, >>> it looks like we need to add the equivalent to fq_codel ce_threshold >>> behaviors as well. >>=20 >> If I=E2=80=99m reading the legend correctly, you are setting = ce_threshold to 1ms to get the better-controlled result. But that = effectively disables the codel algorithm and turns it into a simple = =E2=80=9Cmark all packets over 1ms sojourn=E2=80=9D for ECN capable = traffic, because it=E2=80=99s a tighter limit than codel=E2=80=99s = target. That=E2=80=99s too aggressive for non-BBR traffic. >=20 > Yes it is. :) However the consensus appears to be that ECN should be > an earlier signal than drop, and the work over on the tcp-prague list > centers around repurposing ECT(1) as more like a DCTCP multi-bit > signal. My interpretation of the consensus is more subtle: we need a signal = earlier than we currently do, and with a weaker meaning, but we still = need the strong, later signal. I don=E2=80=99t think we should use CE for that; it has a = long-established and widely-deployed meaning. We *can* use ECT(1), = which is presently unused in practice. > I'm really not sure if what I've seen with ce_threshold is the > desired behavior, vs a vs BBR, thus far - but I'd like to see the > option for it enter cake. Before I even consider doing that, could you add a comparable run with = the current version of cake to that graph? COBALT is not quite = identical to Codel, and this looks like a case where one of the = differences could be important. - Jonathan Morton