From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f47.google.com (mail-wg0-f47.google.com [74.125.82.47]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 84CFB200B29 for ; Sun, 6 May 2012 11:26:58 -0700 (PDT) Received: by wgbfa7 with SMTP id fa7so3394387wgb.28 for ; Sun, 06 May 2012 11:26:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; bh=gFsYdaFy5kb1w61rhSAyNGjNbIZVatXIrR/nbPQFB9Y=; b=Mj5xoxCDio/oV+BvEIV/f63faxRt28jRWObEsf4AXOyabLp3zECgqFIYmssKNkvYFw lgoVBmPiZumO2+Slz5H3OetKE8qKMdOUCrtMIWKhAX9Y1jajfapRwC7yGyTA/UuRZQKZ 3iCJiGQHt6hJgr8m/BXTK2A74j8iAakq8kqe0tuT0NwdkSy79HVz2Or4WOUt894s+I8e PIlf4vZuwlKz1vnTD9IGyoPLalaR6Vef0MYkHY6xYyNs+dRz7Vchxa+Q8U+vFKgbV1x+ uO+x6XrYFSuq+BANvQIjWHEU5+qZcQsWtxjmV/VVJUBmPyb3nzvDIbhOBux4yJCkeybd 1Crg== MIME-Version: 1.0 Received: by 10.180.100.230 with SMTP id fb6mr3143416wib.3.1336328816587; Sun, 06 May 2012 11:26:56 -0700 (PDT) Received: by 10.223.112.66 with HTTP; Sun, 6 May 2012 11:26:56 -0700 (PDT) In-Reply-To: <1336328140.3752.2014.camel@edumazet-glaptop> References: <1336281092.3752.982.camel@edumazet-glaptop> <1336283203.3752.1032.camel@edumazet-glaptop> <1336315913.3752.1598.camel@edumazet-glaptop> <1336324134.3752.1825.camel@edumazet-glaptop> <4FA6B2FB.2030809@freedesktop.org> <1336328140.3752.2014.camel@edumazet-glaptop> Date: Sun, 6 May 2012 11:26:56 -0700 Message-ID: From: Dave Taht To: Eric Dumazet Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: codel@lists.bufferbloat.net Subject: Re: [Codel] usage of 'count' in codel X-BeenThere: codel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: CoDel AQM discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 06 May 2012 18:26:58 -0000 On Sun, May 6, 2012 at 11:15 AM, Eric Dumazet wrot= e: > On Sun, 2012-05-06 at 13:20 -0400, Jim Gettys wrote: > > > >> I sort of think that having some upper queue time bound makes sense, if >> only to ensure that TCP's quadratic (un)responsiveness never gets out of >> hand. =A0But we agreed that having an implementation we could play with = to >> observe reality would likely be better than hand-waving with no >> experience about how long the queue should be allowed to grow. > > Even with normal tcp flows, codel is not responsive enough and too > conservative as is. > > drop_next =3D control_law(drop_next) =A0 with interval/sqrt(count) > increments ? > > Something is _really_ wrong. > > Thats few drops per second when we need far more than this. > > interval =3D 100ms so you need count =3D 10000 to reach the rate of one d= rop > per ms, regardless of the link capacity. with the >>1 change. At 100Mbit I see observed delays that aren't bad, and queue lengths that are quite nice. That's with ethernet ratcheted down to 100Mbit with ethtool, no TSO/GSO with BQL. 1 netperf, 5ms delay on ping RTT 30, about ~12ms And in both cases the box on the other end is in drop tail. I don't trust htb at this point, if that's what you are using? qdisc codel 8007: root refcnt 2 limit 1000p minbytes 1514 target 5.0ms interval 100.0ms Sent 5995574344 bytes 3975635 pkt (dropped 145097, overlimits 0 requeues 1842324) backlog 86298b 58p requeues 1842324 count 4549 delay 6.7ms drop_next 580us What do you see at 10GigE with like 60 netperfs? (god, can you even drive 10GigE that hard? me is jealous of hardware. I CAN get to where I can drive GigE now, I just want to update both sides of the connection to be codel capable, and am waiting on a more final patch) > > control loop has no input on time of residence of packets. > > > --=20 Dave T=E4ht SKYPE: davetaht US Tel: 1-239-829-5608 http://www.bufferbloat.net