From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-x22c.google.com (mail-wi0-x22c.google.com [IPv6:2a00:1450:400c:c05::22c]) (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 7666A21F730 for ; Sun, 26 Jul 2015 14:05:54 -0700 (PDT) Received: by wibxm9 with SMTP id xm9so92106268wib.1 for ; Sun, 26 Jul 2015 14:05:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:to:references:cc:from:message-id:date:user-agent :mime-version:in-reply-to:content-type:content-transfer-encoding; bh=6mqRvQV89JKQSs+vnBGorPvF6RnZ7/dhVyPLznnpapo=; b=BrQIV8/c+E4EH57JqY/wKhyh2L0cfYhNkKDl01ADwwF66n4ByzSfHwj7ry260izDr1 JVh77da1nhWpkjGnWr00fS2aJ0ySC0bdhCTApdyMEmBqILAb1OGxU91II2Lpp7cNJOxP 62CHLvOY9+Ojh63W6OmiHnP9Pz66kiZdtK2TiN2Lr04QY3pZIZ3vU2waU85b3bNXZ98j 6g/z03oKSABYeMTMkt8+SkuSg+4MBsRoQU6EGMed9bA0gsShF6JbahaRR+6rDaYnW1+7 m9vlRzrKRtv4JSOEmHB9BnS1Pei5pCURBUgBxIchF/FjibGqs5AUzhuF66mTdga71X92 RTPw== X-Received: by 10.194.250.69 with SMTP id za5mr48247012wjc.90.1437944753089; Sun, 26 Jul 2015 14:05:53 -0700 (PDT) Received: from volcano.localdomain (host-89-243-101-59.as13285.net. [89.243.101.59]) by smtp.googlemail.com with ESMTPSA id kb1sm2193550wjc.24.2015.07.26.14.05.51 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 26 Jul 2015 14:05:52 -0700 (PDT) To: Alec Robertson , Jonathan Morton References: <1437941360960.ed6ad09f@Nodemailer> From: Alan Jenkins Message-ID: <55B54BAE.5000002@gmail.com> Date: Sun, 26 Jul 2015 22:05:50 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: <1437941360960.ed6ad09f@Nodemailer> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit Cc: cake@lists.bufferbloat.net Subject: Re: [Cake] How to test Cake on TP-Link WDR3600 X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.13 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, 26 Jul 2015 21:06:23 -0000 On 26/07/15 21:09, Alec Robertson wrote: > I’ve just updated to the newest trunk release of OpenWRT Chaos Calmer > (fresh install) and the SQM QOS from OPKG interestingly does include > Cake as a qdisc but neither layer_cake.qos nor piece_of_cake.qos are > available as setup scripts. > > I’m still trying out Cake so I’ll be back soon with some feedback. > You should find the cake option there does nothing? It'll only work if you have the "kmod-sched-cake" package providing /lib/modules/*/sch_cake.ko. It's only in Dave's recent experimental builds. fq_codel is the more supported option and serves the same functions. If you can notice any difference yet, I think we'd love to hear about it. Currently I believe the noticeable differences are 1. if your router has TCP offloads enabled, cake undoes ("peels") it some to improve latency. (Getting this past review for mainline Linux sounds increasingly "interesting"). 2. for networks with many flows, cake works much harder to avoid "hash collision" (entirely?), so every flow gets a fair share. fq_codel defaults to 1000 hash buckets (but collision probability will increase well before that point, see "birthday paradox"). 1) seems a real concern for some new routers. If you are affected you could add a boot script using ethtool. The idea is it's not optimal to disable offloads universally... maybe if you're sharing a usb drive from the router as well or something. Having cake handle it works as a great default configuration. (I just suspect Linux devs would ask why the feature can't be enabled on other packet schedulers, e.g. by using a stackable peeler qdisc). Alan