From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-il1-x12a.google.com (mail-il1-x12a.google.com [IPv6:2607:f8b0:4864:20::12a]) (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 503C03B29D for ; Tue, 21 Apr 2020 19:27:42 -0400 (EDT) Received: by mail-il1-x12a.google.com with SMTP id r2so89113ilo.6 for ; Tue, 21 Apr 2020 16:27:42 -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=Ha1/f1Q/C9GBnZpJ8gcUE5BX1rV9QWA9BTGQr3abt+A=; b=Kzy/Ap6Nqt8pQiIYk0XwRqIdyKk6XkaJmtuGuLYYMby42IPW2fWjNP2/oiaxo+XNoA 66mzZcdTqnbvERFxmnlg+ziHw9d1cpU2G5ysyGr/AtLqp5KvG+peIlI9BKMOLBkGBnWk xN+MZyBNTCsdpI8w2PiiyKTqnCcN5CGhRAl0DyzZ86Hsvp2Zkv9jeLeKgidTXGTfbK0a j9aIhNOPVTi6e5RYBdwx5pMbFHJtioIFpZkFn3gwtDqV/HLKpUIT6Rq522N9fQe1Mfnx tx/jTAnP/gsDtkIO9C4CzQ+eOX4hb8M5VQkHSWNUDr2hV6tEu5QCcRw1TLyTMXjXwcnS wgiQ== 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=Ha1/f1Q/C9GBnZpJ8gcUE5BX1rV9QWA9BTGQr3abt+A=; b=uRWNwQmqOPMThqeuuJFwg2DCnybd1AOJMvolqbg995QcyzFCvkFnakxSURQ4gciwUp Jf6c2wm5SyHwX9y4FkXWkeWMbaRQWTeAFEdeyXZCOA+WtB94yBzaS39sk6ike7Ccmfhu blb/qll7/qRaWBOFyVUMV3Qix720zHzWOFiwXDzsz8nBrtUxacsl4F+gNFTSxEJ6Gfwy sB/qcn7hJquaYyff+evEv9204o+BtdXEEeEq7bYkitps0XnME9aVQAMJc7Clp88/oHiA E+OdpGLU76C3LDZWD1efEquBOsHIBp2JMEhNlkUIHm5Thd/epTTX5+2IVMJtQJBmgCzZ qYVw== X-Gm-Message-State: AGi0PuZQc/t2EfZh4W3Xce1e+uXoeEeQSMFy9j52yVBK662fPmERxRJ/ /h+0OMqet7ojwdqd/k9HXRIdpPE5v9uHkgfD9aw= X-Google-Smtp-Source: APiQypKOvkSKFjPIB/cl4fWQIEFIpWorUTRGlyL752qCGnXcJnEPeOSboyRc1vvagXzTuplswdjB2tQia+CJiCWhRl0= X-Received: by 2002:a92:c7a9:: with SMTP id f9mr9822451ilk.0.1587511661758; Tue, 21 Apr 2020 16:27:41 -0700 (PDT) MIME-Version: 1.0 References: <75FEC2D9-BFC8-4FA2-A972-D11A823C5528@gmail.com> <603DFF79-D0C0-41BD-A2FB-E40B95A9CBB0@gmail.com> <2044323F-4CD0-4A75-91DF-FF2DA3E41B86@gmail.com> In-Reply-To: <2044323F-4CD0-4A75-91DF-FF2DA3E41B86@gmail.com> From: Dave Taht Date: Tue, 21 Apr 2020 16:27:30 -0700 Message-ID: To: Jonathan Morton Cc: Thibaut , Cake List Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: Re: [Cake] Advantages to tightly tuning latency X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 21 Apr 2020 23:27:42 -0000 On Tue, Apr 21, 2020 at 4:07 PM Jonathan Morton wro= te: > > > On 22 Apr, 2020, at 1:50 am, Dave Taht wrote: > > > > Jon, how's SCE looking? ready for a backport yet? > > We can't do any sort of wide deployment of SCE until it's been approved a= s an Internet experiment by the IETF. If the present algorithm on the qdisc is stable, I'd like to try it on wifi= . > Interested individuals can already compile the SCE-enabled kernel and jum= p through the hoops to try things out - carefully. There's a bit of infras= tructure code to go with the new TCP algorithms and qdiscs, so I'm not cert= ain how easy a backport would be; better to just build the (relatively) cur= rent code for now. Not on openwrt. It seemed easy to backport just cake there, and the rest of the code on dedicated servers and clients. Similarly I'd try for the wifi attempt also. I care about the cpu impact a lot. Also a recent string of postings on netdev that I have had too much PTSD to reply to seem to indicate that accecn *requires* that the tcp offload engine be disabled, which is difficult to swallow. Can SCE work with tcp offloads enabled (on the server, client and qdisc?)? The same post claimed that apple proved we could "just turn ecn on", and to explore that claim I updated my osx to the latest only to immediate find apple's heuristics *disabled* attempts at ecn negotiation on the second of two rrul tests, and I'd also poked into a worldwide dataset that showed WAY less ecn attempts making it from apple gear to the test server. Another post (which I have not responded to either) pointed to an improvement in the 3WHS that may or may not be genuinely useful, but at that point, I went back to fixing wifi with what I knew worked. The code itself, was not bad. Perhaps some review of that set of patches and thread is needed by some others with stronger stomachs. https://www.spinics.net/lists/netdev/msg638882.html > > IETF TSVWG interim meeting next week (the second of two replacing planned= in-person sessions at Vancouver) will discuss the big ECT(1) issue, which = is hotly disputed between SCE and L4S. The key question is whether ECT(1) = should become a classifier input to the network (orthogonal to Diffserv but= with some of the same basic problems), or an additional congestion signal = output from the network (indicating a lesser degree of congestion, to which= a smaller and more nuanced response is desired). It's anyone's guess how = that will turn out, but the technical merit is on our side and that really = should count for something. > > If you're keeping an eye on the TSVWG list, expect a major bombshell to d= rop there in the next few days. I do. I wish more did. Beverage in hand. :) > - Jonathan Morton > --=20 Make Music, Not War Dave T=C3=A4ht CTO, TekLibre, LLC http://www.teklibre.com Tel: 1-831-435-0729