From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pz0-f43.google.com (mail-pz0-f43.google.com [209.85.210.43]) (using TLSv1 with cipher RC4-MD5 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id B1CEE200681 for ; Sun, 13 May 2012 23:33:38 -0700 (PDT) Received: by dajz8 with SMTP id z8so8865656daj.16 for ; Sun, 13 May 2012 23:33:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; bh=Z/GOjW926Qir+HNFKHkWSaqOvKk9J8BJZP8LjDrUg6g=; b=YsJ/0QqdxUcEVBeaPBnEHDTR7qmqD+7Je/2gbGtHnmI0l5b/7o1gyZ7XpO1o7h6w5m fgp39L7YY7lwGwH8bqcMbq7kunX/0uy8oaCJrjuMtQctcyKNzBMZSl9AztOy/2PxFHUm v86d1lo7mC6Sbc2W+Qfiq3qlwYAU9zYE6E+qNAUxce7/THoeYSVEXP6c8Xd0d8IdzS6s XrZw7Njza3UradWQ6rGG5LUpdawvHWx3O1WcAHbD944rFqC3KHB09UXWwnczDbeOiJIU fABaPPFtg268M03F/Bsdyz6zYHuyQe+PJhl6JYwr0RuqmhNBeY+HaSge1ujRe6/7Z5By gLiw== Received: by 10.68.225.198 with SMTP id rm6mr19285689pbc.89.1336977218191; Sun, 13 May 2012 23:33:38 -0700 (PDT) Received: from ?IPv6:2001:4f8:3:203::c001? ([2001:4f8:3:203::c001]) by mx.google.com with ESMTPS id oz9sm21285881pbc.68.2012.05.13.23.33.36 (version=SSLv3 cipher=OTHER); Sun, 13 May 2012 23:33:37 -0700 (PDT) Message-ID: <4FB0A73F.9090501@gmail.com> Date: Sun, 13 May 2012 23:33:35 -0700 From: dave taht User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:11.0) Gecko/20120410 Thunderbird/11.0.1 MIME-Version: 1.0 To: Eric Dumazet References: <1336855256.31653.1329.camel@edumazet-glaptop> <20120512.164513.1156706853054390966.davem@davemloft.net> <1336859324.31653.1385.camel@edumazet-glaptop> <20120512.175217.1632102067268101115.davem@davemloft.net> <1336893803.8512.43.camel@edumazet-glaptop> <4FB09F8D.6070403@gmail.com> <1336976277.8512.46.camel@edumazet-glaptop> In-Reply-To: <1336976277.8512.46.camel@edumazet-glaptop> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: codel@lists.bufferbloat.net Subject: Re: [Codel] [PATCH net-next] codel: use Newton method instead of sqrt() and divides 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: Mon, 14 May 2012 06:33:39 -0000 On 05/13/2012 11:17 PM, Eric Dumazet wrote: > On Sun, 2012-05-13 at 23:00 -0700, dave taht wrote: >> I am sitting here with the latest fq_codel implementation on cerowrt, and >> this new 16 bit change. >> >> With either interface, running netserver on the router, I get >> ~260Mbit/sec out of it, >> with fq_codel on. It's quite marvelous, as ping times stay in the 2-3ms >> range... >> > If you disable TSO and GSO, do you still get good numbers ? > >> Running traffic through the router with two fq_codels is another story. >> >> I get only 91.6Mbit out of it (and the cpu on the router is loafing). I >> was rather puzzled as >> this is sooclose to 100Mbit as for me to assume that I had goofed and >> was running >> at line rate, but no, I'm at gigE on both sides. >> >> A) Scheduler granularity? HZ_256 and NO_HZ here. Not sure of the clock res I rebooted the whole lab... (it's very satisfying to do that, watching all the lights blinking) Even more satisifying was getting back to where I had ~240Mbit through fq_codel on both sides. (and it didn't crash due to the other bug I'd been battling) I'm thinking I'd ended up with a ifb lying around, or something getting routed through wireless... > fq_codel has no HZ dependencies. (it uses ktime_get()) > > But are you using fq_codel alone (as the root qdisc), or as leaves in a > more complex tree ? I HAD been using htb and ifb in front of codel. I thought I'd deleted it entirely... I had rebooted the router, but something else in the chain was funky... (installed net-next on the test servers to make sure, too) Anyway: root@codel:~# QMODEL=fq_codel QDEBUG=1 IFACE=ge00 /usr/sbin/debloat (this script disables tso/gso/etc) qdisc del dev ge00 root qdisc add dev ge00 handle a root fq_codel root@codel:~# tc -s qdisc show dev se00 qdisc fq_codel a: root refcnt 2 limit 10240p flows 1024 quantum 1514 target 5.0ms interval 100.0ms ecn Sent 3639976192 bytes 2436533 pkt (dropped 0, overlimits 0 requeues 77594) backlog 240534b 161p requeues 77594 maxpacket 1494 drop_overlimit 0 new_flow_count 373 ecn_mark 367 new_flows_len 0 old_flows_len 4 > >> B) The new error in the new sqrt routine actually significant enough to >> show up So never mind....... >> I will try a 20ms target and revert to the previous fuller precision >> version. I wish I had data on the previous version but was battling an >> entirely different bug, then. never mind. next time before emailing I'll hit the big red lab button. >> Has anyone hooked up a chain of codel ns3 sims to each other? >> >> Or a few gigE boxes through each other? This is still an interesting question, though, as ecn is not well understood... >