From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-x22e.google.com (mail-ob0-x22e.google.com [IPv6:2607:f8b0:4003:c01::22e]) (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 3EF0721F38D for ; Thu, 7 May 2015 21:20:29 -0700 (PDT) Received: by obblk2 with SMTP id lk2so47409952obb.0 for ; Thu, 07 May 2015 21:20:29 -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=liKGkkM+dA79XS0k3oMqUbK1HiF6K3f4TOhvaQ5iQK4=; b=CWWuU+vHpRtseR2S4dn3ZNs2H2sclopI1KAhbqUEpLLxNtzu0kTZO55qOH+n6JHbEu nGHsyyCY/DuQXYoDPwtxX6u1EouFTAQIw0aIaN2WHD9HAGPaZhuzVoZJO3ZIAtZgqLTy VtqGDaW41y95NzkOEfadhLPd+GuJgeNSN42nye7Bze8D84rry7wfRfbp0MWVFwe7iBRA 7XnkN8eRcIyLh4ruwanuHNYco0Sls2tZqyzajdSsaMXqn7CpZDAIh2wcNjoE5sdpzvFW ZjDFwdQxLSVtagSYQU35KZvT6UvRZlXgX8jvmSrjyWA8Uh7wCGAO7nBbyB4R/TWrJAvn Pcqg== MIME-Version: 1.0 X-Received: by 10.60.178.33 with SMTP id cv1mr1554241oec.11.1431058828970; Thu, 07 May 2015 21:20:28 -0700 (PDT) Received: by 10.202.71.139 with HTTP; Thu, 7 May 2015 21:20:28 -0700 (PDT) In-Reply-To: <1431057292.22756.6.camel@edumazet-glaptop2.roam.corp.google.com> References: <2288B614-B415-4017-A842-76E8F5DFDE4C@gmx.de> <553B06CE.1050209@superduper.net> <14ceed3c818.27f7.e972a4f4d859b00521b2b659602cb2f9@superduper.net> <0C930D43-A05B-48E2-BC01-792CAA72CAD1@gmx.de> <5549A1B8.50005@superduper.net> <9CF0E173-2CE5-4950-84D1-44EAEF174882@gmx.de> <14d2ed6f160.27f7.e972a4f4d859b00521b2b659602cb2f9@superduper.net> <1431057292.22756.6.camel@edumazet-glaptop2.roam.corp.google.com> Date: Thu, 7 May 2015 21:20:28 -0700 Message-ID: From: Dave Taht To: Eric Dumazet Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: bloat Subject: Re: [Bloat] DSLReports Speed Test has latency measurement built-in X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 08 May 2015 04:20:58 -0000 On Thu, May 7, 2015 at 8:54 PM, Eric Dumazet wrote= : > On Thu, 2015-05-07 at 16:09 -0700, Dave Taht wrote: > >> Recently I did some tests of 450+ flows (details on the cake mailing >> list) against sch_fq which got hopelessly buried (10000 packets in >> queue). cake and fq_pie did a lot better. > > Seriously, comparing sch_fq against fq_pie or fq_codel or cake is quite > strange. I have been beating back the folk that think fq is all you need for almost as long as the pure aqm'rs. Sometimes it makes me do crazy stuff like that test... or use pfifo_fast... just to have the data. In the 450 flow test, I was actually trying to exercise cake's ultimate deal-with-the-8way-set-associative collision code path, and ran the other qdiscs for giggles. I did not expect sch_fq to hit a backlog of 10k packets, frankly. > sch_fq has no CoDel part, it doesn't drop packets, unless you hit some > limit. > First intent for fq was for hosts, to implement TCP pacing at low cost. that was a test on a 1gige server running those qdiscs, not a router. I am sure the pacing bit works well when the host does not saturate its own card, but when it does, oh, my! > > Maybe you need an hybrid, and this is very possible to do that. fq_pie did well, as did cake. > I did recently one change in sch_fq. where non local flows can be hashed > in a stochastic way. You could eventually add CoDel capability to such > flows. > > http://git.kernel.org/cgit/linux/kernel/git/davem/net-next.git/commit/?id= =3D06eb395fa9856b5a87cf7d80baee2a0ed3cdb9d7 I am aware of that patch. My own take on things was that TSQ needs to be more aware of the total number of flows in this case. > > --=20 Dave T=C3=A4ht Open Networking needs **Open Source Hardware** https://plus.google.com/u/0/+EricRaymond/posts/JqxCe2pFr67