From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io1-xd29.google.com (mail-io1-xd29.google.com [IPv6:2607:f8b0:4864:20::d29]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 7F01D3CB37 for ; Fri, 26 Jul 2019 11:05:25 -0400 (EDT) Received: by mail-io1-xd29.google.com with SMTP id k8so105482742iot.1 for ; Fri, 26 Jul 2019 08:05:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=FvwawBvbETOq4jCNgh80mwUnjQ2OUCNK1tEWlwAtcj0=; b=XCKw4O+9/rEIpFH4uMcaphokmLfH/rWenilbsTTJBdArAgp5Q3FtA7mOnSg/B/fw5S OnbwWoZ2Hk4dKFI2d7DmUGmwTb5y0gPSReTWyMpugOrZeRlJpnoVg1XdBqgzO6e+/66l H7MaHMKrQqAReJDaqx266Z9iKoWzVxpUv1GKlRj0W9b1ucCFO8ZqLitpuiHDZdIagKDM ZDD6sH4/zAfuPIJCgGJUF8piSFLQ5BfmyIxVpcziQSqpKWOniYPqS/SQHquGZ832rr6s i7Tii/AuKN+3/1szBp17rMaaiLeyyhnxgdHsYWeFHtkp+GHoqn4mypgGLIo24HjrQQrS ezEQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=FvwawBvbETOq4jCNgh80mwUnjQ2OUCNK1tEWlwAtcj0=; b=YTJJ06c+T4yrbFFV5gxK0DuLrkDJa1K6XVGN4p0t+lI6RerEwSiwQ5Fs5PZ5zts+gN ySwyRK5eKS+uBVE1oQaaDa7q/pBf2w7zOr1YbbmteeTfmBaABXwhAnrAC2HIkqoVOPmF ZiycuT2H1TqnCagcOpTNHSMzBbEY/oFHjGM6ouO4EN62ybt27bS8GTexvxeHhSHI832O 0427nPHpX2ZZl5oy+NZc851BNML7hWolUElWADawH8CluEzHCQ+WWlnL1V7zT7r4zgf8 Fo0GyQnXElkZhy6p66rBOY4/6D1lqfccNO1V6X7Y+03G7oaj6eVb5wL5y5v9zQCtngog iu2w== X-Gm-Message-State: APjAAAXitpVaCKp+XG1pohgM8nGGCGez6ZK69rNUT6KlDkyrPGX2ASBl PwdQjW+8zxSgeWwNgh1Bmtm8S9YxmNbgoYbLhB0= X-Google-Smtp-Source: APXvYqyuzOKZKAdTUAZiQprudg4CjM7kNVawevxcms5PDMkaoyN5b9WXpeV0TMpuOKndncRcbpbJv1yd42frYW0ik78= X-Received: by 2002:a02:c9d8:: with SMTP id c24mr44797358jap.38.1564153524677; Fri, 26 Jul 2019 08:05:24 -0700 (PDT) MIME-Version: 1.0 References: <364514D5-07F2-4388-A2CD-35ED1AE38405@akamai.com> <1238A446-6E05-4A55-8B3B-878C8F39FC75@gmail.com> <17B33B39-D25A-432C-9037-3A4835CCC0E1@gmail.com> <52F85CFC-B7CF-4C7A-88B8-AE0879B3CCFE@gmail.com> <87ef2myqzv.fsf@taht.net> <803D9CA8-220E-4F98-9B8E-6CE2916C3100@gmail.com> <0079BC6B-4792-48ED-90D3-D9A69407F316@gmx.de> <22af0671-fdd0-0953-fc96-55b34beb0be9@bobbriscoe.net> <3EB0D59D-69A7-4730-BCDF-10E5C61EF987@heistp.net> In-Reply-To: From: Dave Taht Date: Fri, 26 Jul 2019 08:05:11 -0700 Message-ID: To: Pete Heist Cc: "De Schepper, Koen (Nokia - BE/Antwerp)" , "ecn-sane@lists.bufferbloat.net" , "tsvwg@ietf.org" , Neal Cardwell Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: [Ecn-sane] The state of l4s, bbrv2, sce? X-BeenThere: ecn-sane@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Discussion of explicit congestion notification's impact on the Internet List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 26 Jul 2019 15:05:25 -0000 Changing the title.... I hope to be able to add some features and boxes to the worldwide flent fleet to gather up some more data. Simple stuff includes trying to verify more fully worldwide what happens when you twiddle the ecn bits, mildly longer term look at what happens when conflicting interpretations of these bits are in play somewhere on the path, bit longer than that getting an openwrt build up as a middlebox and vm, and then finally, finally see what happens on a couple kinds of wifi. There's now a flent server in mumbai, in particular, which I hope will shed some insight as to the state of networks in india, long term, on a variety of fronts. But none of it's ready lacking a good release to freeze on. 1) BBRv2 is now available for public hacking. I had a good readthrough last night. The published tree applies cleanly (with a small patch) to net-next. I've had a chance to read through the code (lots of good changes to bbr!). Although neal was careful to say in iccrg the optional ecn mode uses "dctcp/l4s-style signalling", he did not identify how that was actually applied at the middleboxes, and the supplied test scripts (gtests/net/tcp/bbr/nsperf) don't do that. All we know is that it's set to kick in at 20 packets. Is it fq_codel's ce_threshold? red? pie? dualpi? Does it revert to drop on overload? Is it running on bare metal? 260us is at the bare bottom of what linux can schedule reliably, vms are much worse. Couple notes: BBRv2 doesn't use ect(1) as an identifier. The chromium release has no support for ecn at all. Adding back in the stuff I'd first done to rfc3168 bbrv1 looks straightforward, making it do sce, less so. 2) To clarify something from the l4s team, are the results you've been presenting for years all from the 3.19 kernel? bsd? microsoft? ns2? ns3? what? The code on github is not worth testing against currently? It does have some needed features like a setsockopt for using up ect(1). should I use the issue tracker for that? I have some comments on dualpi in addition to my outstanding question about pie's default of drop at 10% mark rate vs dualpi's 0. Notably it's set to 1000 packets now (fq_codel defaults to 10,000 and we switched to memory limits both in it and cake given a modern packet's dynamic range of 64b to 64k). I've observed 10gige can be in the 2-3k packets range... has dualpi been tested above 1gige yet? 3) The current patches for sce need to get rebased for net-next. The sch_cake mods are easy but as the dctcp code did morph a bit since sce work forked it as did the other tcps. I took a stab at forward porting it to net-next, but I figure that development is hot and heavy and some patches will land after ietf. I do not mind taking a stab again at cleaning it up (helps me to understand what's going on), as how the algos currently (as of, like, yesterday) work is clear to me... what I'd like to do at least is also add 'em to the out of tree fq_codel_fast implementation. Did I miss anything about the current state of things? My basic testbed is a string of containers on a couple 12 core boxes on bare metal, and more advanced is the openwrt stuff part of my wifi lab. That's presently almost all 4.14 based on arm, mips, and x86, running both on real hardware and in emulation. On Fri, Jul 26, 2019 at 6:10 AM Pete Heist wrote: > > > > On Jul 25, 2019, at 12:14 PM, De Schepper, Koen (Nokia - BE/Antwerp) wrote: > > > > We have the testbed running our reference kernel version 3.19 with the = drop patch. Let me know if you want to see the difference in behavior betwe= en the =E2=80=9Cgood=E2=80=9D DCTCP and the =E2=80=9Cdeteriorated=E2=80=9D = DCTCP in the latest kernels too. There were several issues introduced which= made DCTCP both more aggressive, and currently less aggressive. It calls f= or better regression tests (for Prague at least) to make sure it=E2=80=99s = behavior is not changed too drastically by new updates. If enough people ar= e interested, we can organize a session in one of the available rooms. > > > > Pete, Jonathan, > > > > Also for testing further your tests, let me know when you are available= . > > Regarding testing, we now have a five node setup in our test environment = running a mixture of tcp-prague and dualq kernels to cover the scenarios Jo= n outlined earlier. With what little time we=E2=80=99ve had for it this wee= k, we=E2=80=99ve only done some basic tests, and seem to be seeing behavior= similar to what we saw at the hackathon, but we can discuss specific resul= ts following IETF 105. > > Our intention is to coordinate a public effort to create reproducible tes= t scenarios for L4S using flent. Details to follow post-conference. We do f= eel it=E2=80=99s important that all of our Linux testing be on modern 5.1+ = kernels, as the 3.19 series was end of life as of May 2015 (https://lwn.net= /Articles/643934/), so we'll try to keep up to date with any patches you mi= ght have for the newer kernels. > > Overall, I think we=E2=80=99ve improved the cooperation between the teams= this week (from zero to a little bit :), which should hopefully help move = both projects along... > _______________________________________________ > Ecn-sane mailing list > Ecn-sane@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/ecn-sane --=20 Dave T=C3=A4ht CTO, TekLibre, LLC http://www.teklibre.com Tel: 1-831-205-9740