From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-x235.google.com (mail-qt0-x235.google.com [IPv6:2607:f8b0:400d:c0d::235]) (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 424123B29E for ; Mon, 30 Apr 2018 17:27:45 -0400 (EDT) Received: by mail-qt0-x235.google.com with SMTP id h2-v6so12669032qtp.7 for ; Mon, 30 Apr 2018 14:27:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=g04cMgm3d8lvOHlBFSbe69hsg8881H2B9dg0v9pQHyU=; b=XYlYBOFzW9oX790of5xMnZYk/COu6soucxAyGSMGdsPVGIek45oDC2v7EZDP48vQSz QJseOZ8UEM7yomMD0jSk1g/kgFsLX/sRoi6Xwrb2TjbcZ+cpv/V1daVG9q7B+FTyYZmr aQ9yP4dWS6c6JJ59MYCNEMgabbC/QJp5krjnEyJZw9I2/7Q4uH43owxp8Dd+uKR9DgQ7 1zZ+jBjyjg9vCzg4MfF8blHzTGMPMTCSdiJNwTIBErA5YfmFQS2NUCiS9tL1k6c6TcFo mnY7pgUVotsxowd6ajTsgLk0WUktpjBlbrCme8AUvZdE+0Wu6YXBisGlGM76N/SxQ5rU e5YA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=g04cMgm3d8lvOHlBFSbe69hsg8881H2B9dg0v9pQHyU=; b=JvL4GJhqrBHYpbHCw4hAkk11OvJU2AWVcSJIf7kzsVE9RPXjCSPo5BWnWDOmdRdtZR WUIesYJk5cOpEP4YAR6IZgoAIkkTbZTOFyvA2+9vg0Rf9zxFwmyyCAl1d4AqDY0zBM53 ISrr6mDm4GDClgErCUAMcCf82ra9FJjImzd4kgaV3si/D5j9MItxfOt+BcZ/C0G92tDa 8Du2aug1j3oLwEYEtBWLixQe1skTPnlLCDwk3KIiWzklyiaUNs39ATKBpVXsKOOZJzP/ e15Vyu33OQEEUUe/zPxB74HOdqKzeYr/iVFcA77Jdkker7QQSIes5xm4fANc8ywp0f5V I2Sg== X-Gm-Message-State: ALQs6tA0dTy8ceZX6jwWYtRs4PrqnA2R7skYHeM3Ks6o/iMtkDWON/65 LtsghrwUiXAh47GEbq2cx15Tmah1+VaJA5xC6DY= X-Google-Smtp-Source: AB8JxZq2yTrAwx6OUxIk36fnKSBkVfJYqYZOX2Yx2Ph51PHL+l2zdMQLnKyr9/QgMCscYbZbpKiF4UIA8XZx5eYBLqs= X-Received: by 2002:a0c:b294:: with SMTP id r20-v6mr11880249qve.9.1525123664686; Mon, 30 Apr 2018 14:27:44 -0700 (PDT) MIME-Version: 1.0 Received: by 10.12.243.147 with HTTP; Mon, 30 Apr 2018 14:27:44 -0700 (PDT) In-Reply-To: References: <20180429213439.7389-1-toke@toke.dk> From: Dave Taht Date: Mon, 30 Apr 2018 14:27:44 -0700 Message-ID: To: Cong Wang Cc: =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= , Linux Kernel Network Developers , Cake List Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: Re: [Cake] [PATCH net-next v6] Add Common Applications Kept Enhanced (cake) qdisc 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: Mon, 30 Apr 2018 21:27:45 -0000 On Mon, Apr 30, 2018 at 2:21 PM, Cong Wang wrote= : > On Sun, Apr 29, 2018 at 2:34 PM, Toke H=C3=B8iland-J=C3=B8rgensen wrote: >> sch_cake targets the home router use case and is intended to squeeze the >> most bandwidth and latency out of even the slowest ISP links and routers= , >> while presenting an API simple enough that even an ISP can configure it. >> >> Example of use on a cable ISP uplink: >> >> tc qdisc add dev eth0 cake bandwidth 20Mbit nat docsis ack-filter >> >> To shape a cable download link (ifb and tc-mirred setup elided) >> >> tc qdisc add dev ifb0 cake bandwidth 200mbit nat docsis ingress wash >> >> CAKE is filled with: >> >> * A hybrid Codel/Blue AQM algorithm, "Cobalt", tied to an FQ_Codel >> derived Flow Queuing system, which autoconfigures based on the bandwid= th. >> * A novel "triple-isolate" mode (the default) which balances per-host >> and per-flow FQ even through NAT. >> * An deficit based shaper, that can also be used in an unlimited mode. >> * 8 way set associative hashing to reduce flow collisions to a minimum. >> * A reasonable interpretation of various diffserv latency/loss tradeoffs= . >> * Support for zeroing diffserv markings for entering and exiting traffic= . >> * Support for interacting well with Docsis 3.0 shaper framing. >> * Extensive support for DSL framing types. >> * Support for ack filtering. > > Why this TCP ACK filtering has to be built into CAKE qdisc rather than > an independent TC filter? Why other qdisc's can't use it? I actually have a tc - bpf based ack filter, during the development of cake's ack-thinner, that I should submit one of these days. It proved to be of limited use. Probably the biggest mistake we made is by calling this cake feature a filter. It isn't. Maybe we should have called it a "thinner" or something like that? In order to properly "thin" or "reduce" an ack stream you have to have a queue to look at and some related state. TC filters do not operate on queues, qdiscs do. Thus the "ack-filter" here is deeply embedded into cake's flow isolation and queue structures. > > >> * Extensive statistics for measuring, loss, ecn markings, latency >> variation. >> >> A paper describing the design of CAKE is available at >> https://arxiv.org/abs/1804.07617 >> > > Thanks. --=20 Dave T=C3=A4ht CEO, TekLibre, LLC http://www.teklibre.com Tel: 1-669-226-2619