From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-x232.google.com (mail-qk0-x232.google.com [IPv6:2607:f8b0:400d:c09::232]) (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 67A073B2A4 for ; Fri, 24 Nov 2017 08:15:55 -0500 (EST) Received: by mail-qk0-x232.google.com with SMTP id a194so24491398qkc.9 for ; Fri, 24 Nov 2017 05:15:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=HCEKL+nexl5bw9t0mvscxASm6TCtxsT77t8SNl88mTY=; b=j+rj1ffpp6YQhD8d9nuCaG86hV7jdSppE7HC+dwyb1kBNbzdzJ9uP5a7J+KNXYjFGQ H/T/j4hAZg9S2hb2GjqnownY5JNFwz4ojwM/zq9r7ciJ0v82QU1CGlHFc41s5Ean1vtY s1dQmHlQqxIqVpA9hYbF8DuKf6d5sW3ciiq6lp0GrtsZXVvVDBTsiMPeuL1ovMd86mpB 9oSAb1D466iaPk6fN/G0zscrJnhzo5R2Nrgoq9iHOGJ3P8SZzdcTHQElJNvKSJAdBd/I 5nI7i6GPJHEY7FrUf6JrnBW0ANoqpIGi6I83ASJJttpZhNOWrCefose7/re9r/Dk9Ms1 jxUg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=HCEKL+nexl5bw9t0mvscxASm6TCtxsT77t8SNl88mTY=; b=pM1UucP52trYAq96AR6nYqngrqmYOxbzcYvDKYsYm/PSBmwhDMUt8NzhA/iFSPFzL8 v9yzx9h8xLGVVi6Cg/TIsF+xZm7gl4tHPI3tytNeYogZ98A+nWycRLBe6sSLRsCQ4c4m E2hXiMvtwbO+l/xbHiRKvxAmgvOZncJ8shbhG65InlFU8eSgJSR8+LF3ScuSpSX3QoH1 VIG91y9eHpRgFudAJ865m8iYXmlPxR2P54qWZVn/20QU8/Kjx1jsLLDZI98fpd1lMuI1 BadNuvgznb2ouFLSQ08aRH0QMKAlXxP30HvV/7N+Z8mOIshR714gcAKJO5hhRnVIpBMt lXrQ== X-Gm-Message-State: AJaThX6KhED51eZqsiV/0Gtb63J0A3Qt4M1sj/DT3m81rJewJB6BJpTb BbJfiTAdIZmciYu2YUWer6o= X-Google-Smtp-Source: AGs4zMZQulY13rQn4HjuJQ6rpAg4JAbcuXucYmT6U8fWr2n9b82hUyyo+hA6oBVKMnQDKpCK2OHxcQ== X-Received: by 10.55.52.129 with SMTP id b123mr44881898qka.137.1511529341863; Fri, 24 Nov 2017 05:15:41 -0800 (PST) Received: from mail.localdomain ([177.42.99.145]) by smtp.gmail.com with ESMTPSA id x39sm6377372qtc.92.2017.11.24.05.15.39 (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 24 Nov 2017 05:15:40 -0800 (PST) Received: from mail.propriete.com.br (localhost [127.0.0.1]) by mail.localdomain (Postfix) with ESMTP id BF50055B17; Fri, 24 Nov 2017 11:15:36 -0200 (BRST) Received: from localhost.localdomain (unknown [168.181.50.140]) by mail.propriete.com.br (Postfix) with ESMTPSA id 8F27D4C1F9; Fri, 24 Nov 2017 11:15:36 -0200 (BRST) Date: Fri, 24 Nov 2017 11:15:35 -0200 From: Marcelo Ricardo Leitner To: Sebastian Moeller Cc: Toke =?iso-8859-1?Q?H=F8iland-J=F8rgensen?= , Cake List , Pete Heist Message-ID: <20171124131534.GA32400@localhost.localdomain> References: <71FB183D-F848-4513-A6F6-D03FD0F10769@gmail.com> <52C2B216-220C-4C17-882C-9994867E86BB@gmail.com> <87tvxlvsex.fsf@nemesis.taht.net> <87609zapmt.fsf@toke.dk> <11A70C51-8436-46BD-BBD0-8A5E7A2C7AA3@gmx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <11A70C51-8436-46BD-BBD0-8A5E7A2C7AA3@gmx.de> User-Agent: Mutt/1.9.1 (2017-09-22) Subject: Re: [Cake] lan keyword affects host fairness 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: Fri, 24 Nov 2017 13:15:56 -0000 On Fri, Nov 24, 2017 at 01:06:12PM +0100, Sebastian Moeller wrote: > > > On Nov 24, 2017, at 12:21, Toke Høiland-Jørgensen wrote: > > > > Dave Taht writes: > > > >> Pete Heist writes: > >> > >>> On Nov 23, 2017, at 10:44 AM, Jonathan Morton wrote: > >>> > >>> This is most likely an interaction of the AQM with Linux' scheduling > >>> latency. > >>> > >>> At the 'lan' setting, the time comstants are similar in magnitude to the > >>> delays induced by Linux itself, so congestion might be signalled > >>> prematurely. The flows will then become sparse and total throughput reduced, > >>> leaving little or no back-pressure for the fairness logic to work against. > >> > >> Agreed. > >> > >> man page add: > >> > >> At the 'lan' setting(1ms), the time constants are similar in magnitude > >> to the jitter in the Linux kernel itself, so congestion might be > >> signalled prematurely. The flows will then become sparse and total > >> throughput reduced, leaving little or no back-pressure for the fairness > >> logic to work against. Use the "metro" setting for local lans unless you > >> have a custom kernel. > > > > Erm, doesn't this make the 'lan' keyword pretty much useless? So why not > > just remove it? Or redefine it to something that actually works? 3ms? > > The same applies for datacentre (0.1 ms), no? But I agree, let's not expose these as explicit keywords, one can always use "rtt [100us|1ms]" I assume... Which should also contain such disclaimer with it. "Values smaller than 10ms requires special handling.", for example. Marcelo