From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-x22c.google.com (mail-ob0-x22c.google.com [IPv6:2607:f8b0:4003:c01::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 6575F21F42F for ; Fri, 3 Oct 2014 08:46:04 -0700 (PDT) Received: by mail-ob0-f172.google.com with SMTP id wo20so1058033obc.17 for ; Fri, 03 Oct 2014 08:46:03 -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=MA1QamYRnW8NBvdP+4LNiTbkY1Q/LAWVSwdB8AsmwXg=; b=fjBW7kXJesAKxhGIwns1mwmlA2zKca3GuLzE3XHND1BZxzrVVjz7q44ENlXJt3ym0B SjoGHo+3udhGVWZvJAOwxbpRDqVSACpFCgyDcWjrk+qIIBkwjZLex8SiULNMW6+RcBKp yCEPaH5MtMRunT/fSuhyx5tH8T7sJ9ba7SJCsWa5+Z+J65fLBqK7oEy/LdKN/gnvGRUE YnmEwWLqBmKtbgb2it1SCeqgaj8G+zUNHEoG0MJtrsXnuFwBzS3x6tDBsYxRBNxSoC3V tukcojTM5aMUxTeAaASd2pI77rDPPlJE7pSt98lyKgsfQz2ojAAGGermg7zsh77qlrz0 IJ4A== MIME-Version: 1.0 X-Received: by 10.60.51.71 with SMTP id i7mr7971102oeo.41.1412351163777; Fri, 03 Oct 2014 08:46:03 -0700 (PDT) Received: by 10.202.227.76 with HTTP; Fri, 3 Oct 2014 08:46:03 -0700 (PDT) In-Reply-To: <542D05B9.1040601@redhat.com> References: <542D05B9.1040601@redhat.com> Date: Fri, 3 Oct 2014 08:46:03 -0700 Message-ID: From: Dave Taht To: Daniel Borkmann Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: fwestpha@redhat.com, "aqm@ietf.org" , dclc@irtf.org, bloat Subject: Re: [Bloat] DCTCP in linux net-next 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, 03 Oct 2014 15:46:33 -0000 The testing on this DCTCP implementation is documented at: https://git.kernel.org/cgit/linux/kernel/git/davem/net-next.git/commit/?id= =3De3118e8359bb7c59555aca60c725106e6d78c5ce Very Impressive! The use of classification to run this on the same data plane as other traffic was clever, also... Me being me, I'd wanted to test it against fq_codel, codel and pie (all of which support ECN) instead of RED, test it against competing cc algorithms (what harm could a cubic sender do in an otherwise dctcp environment?), all of which were impossible given the age of the patch prior set. I had no faith in the prior (pre-bql-era) results for DCTCP. I am also interested in what effects, if any, sch_fq had on the hosts vs a vs DCTCP. It looks like the code currently falls back to reno, not cubic, if ecn is not enabled, also... There are several tests in netperf-wrapper that could be easily modified to invoke dctcp instead to very rapidly get that sort of data. (the tests are things like cubic_reno reno_cubic_westwood_lp and the various tcp_square_wave tests, the 50 flow test, etc) Regrettably I'm not in a DC environment, I'm still out here, trying to fix the edge. Hopefully someone(s) else here will re-run their tests in with this modernized version of dctcp.... On Thu, Oct 2, 2014 at 12:58 AM, Daniel Borkmann wrot= e: > Hi Dave, > > [ also Cc'ing Florian as co-author ] > > On 10/02/2014 05:20 AM, Dave Taht wrote: >> >> I was surprised and delighted to see that DCTCP has now entered the >> linux net-next kernel (which means it will end up in linux 3.18 if it >> pans out)... >> >> http://thread.gmane.org/gmane.linux.network/332259 >> >> Benchmarkers fire up yer engines! The last benchmarks of DCTCP were >> all from the pre-bql era.... > > > Indeed, please do. ;) We did longer term measurements in a data center > environment as attached to the commit message, mostly to provoke incast > collapse. Results were looking quite promising. > >> In similar news, some patches are tightening up BQL. The improvements >> here are measured in >> 10s to 100s of us, and in cpu savings... >> >> https://patchwork.ozlabs.org/patch/394810/ > > > Thanks, > Daniel --=20 Dave T=C3=A4ht https://www.bufferbloat.net/projects/make-wifi-fast