From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-x22a.google.com (mail-ig0-x22a.google.com [IPv6:2607:f8b0:4001:c05::22a]) (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 883F221F340 for ; Wed, 22 Apr 2015 11:22:27 -0700 (PDT) Received: by iget9 with SMTP id t9so562934ige.1 for ; Wed, 22 Apr 2015 11:22:26 -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:mime-version:content-transfer-encoding; bh=N3qj8bxixYn37wlYGExTfaBzuUVjLZ9R3nqmRlGAwik=; b=cdfWc2PywtJEeeovqLFHL72ToA4RQ5kabfjA75tYVKdQO79GidoVM++p1QOWixAHzx uuUlkWZE7iP33O13Z+tnjs4SltlJoa9e5wn+52TpZZhmMnyN5tdYpSRkbvGvYSZnzRgY Zws1FHxGfUxi8PD/fpXdmuruJhYJY9SUA4cCy9Vpadx4Te08rG92wwa+gLcWDjcCJA3R LbyPGfHxWp1wWrUbNTwhYC5o5Q+yyFOrV+QwPBgAOZmOezkCWn+8RgxiGeRgth/qS4od IAERS1qHHxSBIACYrVwndTaMvi/VaTR08x6fSouBKu+bjlpT0fdGMRThXULq6rVk3+L3 6GFQ== X-Received: by 10.50.45.103 with SMTP id l7mr6406023igm.41.1429726946310; Wed, 22 Apr 2015 11:22:26 -0700 (PDT) Received: from [172.26.55.207] ([172.26.55.207]) by mx.google.com with ESMTPSA id kc1sm3812933igb.0.2015.04.22.11.22.24 (version=TLSv1.2 cipher=AES128-GCM-SHA256 bits=128/128); Wed, 22 Apr 2015 11:22:25 -0700 (PDT) Message-ID: <1429726944.18561.122.camel@edumazet-glaptop2.roam.corp.google.com> From: Eric Dumazet To: MUSCARIELLO Luca IMT/OLN Date: Wed, 22 Apr 2015 11:22:24 -0700 In-Reply-To: <5537DA20.1090008@orange.com> References: <8E4F61CA-4274-4414-B4C0-F582167D66D6@gmx.de> <2C987A4B-7459-43C1-A49C-72F600776B00@gmail.com> <14cd9e74e48.27f7.e972a4f4d859b00521b2b659602cb2f9@superduper.net> <20150422040453.GB36239@sesse.net> ,<1429676935.18561.42.camel@edumazet-glaptop2.roam.corp.google.com> <12383_1429692679_55376107_12383_9099_1_p7gmr0psut68sen0sao8o4lp.1429692550899@email.android.com> ,<1429710657.18561.68.camel@edumazet-glaptop2.roam.corp.google.com> <25065_1429716388_5537BDA4_25065_2328_1_63pyislbvtjf653k3qt8gw2c.1429715929544@email.android.com> <1429717468.18561.90.camel@edumazet-glaptop2.roam.corp.google.com> <5537CDB7.60301@orange.com> <1429722979.18561.112.camel@edumazet-glaptop2.roam.corp.google.com> <5537DA20.1090008@orange.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4-0ubuntu2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Cc: bloat Subject: Re: [Bloat] DSLReports Speed Test has latency measurement built-in 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: Wed, 22 Apr 2015 18:22:55 -0000 On Wed, 2015-04-22 at 19:28 +0200, MUSCARIELLO Luca IMT/OLN wrote: > On 04/22/2015 07:16 PM, Eric Dumazet wrote: > > > > sch_fq adds *pacing*, which in itself has benefits, regardless of fair > > queues : Smaller bursts, less self inflicted drops. > > This I understand. But it can't protect from non self inflicted drops. It really does. This is why we deployed sch_fq and let our competitors find this later. > > > > > If flows are competing, this is the role of Congestion Control module, > > not packet schedulers / AQM. > > Exactly. Two same CC modules competing on the same link, one w pacing > the other one w/o pacing. > The latter will have negative impact on the former in FIFO. Not in FQ > (fq_codel to clarify). Not on modern linux kernels, thanks to TCP Small Queues. > And that's my incentive argument which comes from the flow isolation > feature of FQ (_codel). fq_codel is not something you can deploy on the backbone routers, for known reasons. sch_fq is something you can deploy on hosts, where the codel part is irrelevant anyway (because of TCP Small Queues in modern linux kernels)