From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-x234.google.com (mail-wr0-x234.google.com [IPv6:2a00:1450:400c:c0c::234]) (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 F15823B29E for ; Sun, 19 Nov 2017 13:48:56 -0500 (EST) Received: by mail-wr0-x234.google.com with SMTP id u40so6168821wrf.10 for ; Sun, 19 Nov 2017 10:48:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=3tPllpwoZqBISkch6KofXPQZM0CNAuVZCBKrOersB8w=; b=ZrLh/292Lj6kLusKi0ORuVLL81BAn8jMIFcScUAWlGlC3vUcZ/EAWVGOYH14w599D8 VD8pbTgIRgvX0TV3O8yb/ej22JJRYUuqGQeXItQTevq5+IKBDv8Iw/yqcgPUvYArbrBn lxD6JtLBrcv4VD8K6UsN/gBC96orU9RR9dutGRKgLcvIxc6wwhDyhqn8UcA26nKMGhUW K8et0jzQuDs7gvaSjGT1VpVTk8D3ErgWjy7/BQ3s9HLQ8lcAjMdZItcIAlSLQa4cdU94 zyO8ewaNSgy3xNdb/cpj/XcqQMPhLh/MnpUt4kou5go2xEEnL/DhgUklt6DWfCdBQCiq 9yww== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=3tPllpwoZqBISkch6KofXPQZM0CNAuVZCBKrOersB8w=; b=gJjaP1hFIEZHkjDgwKPHW72brhnobEQeEguABCNQMU+GlpDNgzEwqf5jIrRU/yxDCV Uu++qWhTw5jp10IXGc/Oim/KkfxP38EITHznyijvCyzz5NYNtlTGRcFfEk1KQrVGgvK4 xTvc4kTcxH1oRSYKU71mmONQDshbPFLLgDg6+kp5pWvUCoaKybdJrggDB5sNOWdiqUyY rlt2wFySS2k96x3QaQoyXUdh1dJHYn28YeEmU72VoyZ64FEfk0py2SjEKrqi9yIXj9Kb 7trUYmFf8VPdPkXPOb+ziwgBzwOJfFgpzcMX8Y6PJ3ML/xQc0+1P8OoflbSwGOlTdGxY 242w== X-Gm-Message-State: AJaThX5StHnabRvPXnNZIKFue0ygi+TsyvcGsjXiKrNfQy73YOYKo8zI t2UbHml8GIgURhaoJFs/MzY= X-Google-Smtp-Source: AGs4zMYvCMfOFE9rtOk6ejHcCJNJQCd5LfvxejWAcHtPiZIHtDFBLWiZo99S7NiPyu+zRpQHzF6ySQ== X-Received: by 10.223.151.212 with SMTP id t20mr9873812wrb.2.1511117335974; Sun, 19 Nov 2017 10:48:55 -0800 (PST) Received: from [10.72.0.130] (h-1169.lbcfree.net. [185.99.119.68]) by smtp.gmail.com with ESMTPSA id v5sm5172577wme.26.2017.11.19.10.48.54 (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Sun, 19 Nov 2017 10:48:55 -0800 (PST) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) From: Pete Heist In-Reply-To: Date: Sun, 19 Nov 2017 19:48:58 +0100 Cc: Cake List Content-Transfer-Encoding: quoted-printable Message-Id: <4235D7B6-1CA6-4B57-BA00-97D3F7D44EFA@gmail.com> References: To: Dave Taht X-Mailer: Apple Mail (2.3124) Subject: Re: [Cake] [RFC PATCH 4/5] q_netem: support delivering packets in delayed time slots 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: Sun, 19 Nov 2017 18:48:57 -0000 > On Nov 18, 2017, at 8:02 PM, Dave Taht wrote: >=20 > On Sat, Nov 18, 2017 at 5:18 AM, Pete Heist = wrote: >>=20 >> On Nov 17, 2017, at 11:55 PM,dave.taht@gmail.com wrote: >>=20 >> Slotting is a crude approximation of the behaviors of shared media = such >> as cable, wifi, and LTE, which gather up a bunch of packets within a >> varying delay window and deliver them, relative to that, nearly all = at >> once. >>=20 >> Nice=E2=80=A6 >=20 > Meh. It really is "crude", and I keeping kicking about ways to somehow > emulate half (or less) duplex, variable rates around a mean, mcast, > etc. >=20 > it IS very nice to have a rate limiter that actually behaves a bit > more like wifi, and I hope to also add the new ack fitering stuff to > it. I guess there may never be a way to make this perfect, only to try to = reproduce the behavior that matters enough to make it usable for = testing. >> One of the things I also notice in my LAN tests is latencies for = different >> flows staying at more or less fixed (and different) positions = relative to >> the mean in flent results. Those positions, and the mean, can change = with >> each test run. Do you think this could result from the hashing to = different >> hardware queues (four in my case) changing between test runs? >=20 > yes if you are using bql probably. Is it sch_mq on top? Yep with bql. I hadn=E2=80=99t thought about mq before. What my qos = setup scripts are doing though is replacing the root qdisc (which now I = see defaults to mq) with a single cake instance. With bql, should rather = be leaving mq and putting four cake instances underneath it? >> And is it >> worth trying to simulate this effect, or not really? >=20 > Dunno. There are a couple ways to turn it off. Fair enough...=