From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f45.google.com (mail-ed1-f45.google.com [209.85.208.45]) (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 7DFF13BA8E for ; Fri, 18 Jan 2019 09:33:03 -0500 (EST) Received: by mail-ed1-f45.google.com with SMTP id a20so11261410edc.8 for ; Fri, 18 Jan 2019 06:33:03 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version; bh=pU4O9nDU3bxoCA/PtTeglcum4hmET5zm8x6OvYozDRI=; b=OG8kFu6UreyrO1t4uGBD2Oz6vAaqd1xt8Df9xIxLBLksL4+hrYCuBUGUdJebe1ovPh JCiivheS/rR99cZ3tKSxegaHGEtTEy2Q6Zn+PHxaj/pdTi1WsZ323JImyCqzQc1Tlypj urfEmaP6qWIXTt3llEp316wQfTPPN942JASIlUdAYU07XXn8x+/FYSEI+ii+uVtu2O9J eIuxU94aFfONXtydJT6gXIy3hC4G/vmLGtodazzbnayiNbUMLNg4chXNMUtcrj48gMSp ZUMV5S2WEJTIklVKYRPqxVVVn8wjvM0YsLuna0DxjSMzYlL7qOluZR5E2BRxMc3MnFg3 bgUQ== X-Gm-Message-State: AJcUukdlEtPM+dA7EUrV5DrflkvB5534Dynzzn+uTZHVpPCVhH2I5+ow OHPsVzOjYqHn7CCMlY6nv8vb0tF1ue8= X-Google-Smtp-Source: ALg8bN6/6JsNR76Zlq/lhJMk8ZTVoNkzkdTp3n6BrcmhNjX724OWrO0yUyyU+0/GdqiOvKw6sVX7vA== X-Received: by 2002:a50:8907:: with SMTP id e7mr16335027ede.252.1547821982617; Fri, 18 Jan 2019 06:33:02 -0800 (PST) Received: from tohojo-x1-rh.localdomain (borgediget.toke.dk. [85.204.121.218]) by smtp.gmail.com with ESMTPSA id n23-v6sm3807029ejx.57.2019.01.18.06.33.01 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 18 Jan 2019 06:33:01 -0800 (PST) Received: by tohojo-x1-rh.localdomain (Postfix, from userid 1000) id 6F6A11833C1; Fri, 18 Jan 2019 15:32:59 +0100 (CET) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Jonathan Morton Cc: Georgios Amanakis , Cake List In-Reply-To: <2A195F4F-2F87-4742-93BE-273B5B8DB97D@gmail.com> References: <20190116033430.8446-1-gamanakis@gmail.com> <87pnsumg8s.fsf@toke.dk> <87pnsu3xac.fsf@toke.dk> <2A195F4F-2F87-4742-93BE-273B5B8DB97D@gmail.com> X-Clacks-Overhead: GNU Terry Pratchett Date: Fri, 18 Jan 2019 15:32:59 +0100 Message-ID: <87k1j23ujo.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Cake] dual-src/dsthost unfairness, only with bi-directional traffic 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, 18 Jan 2019 14:33:03 -0000 Jonathan Morton writes: >>> Yes, exactly. Would be interesting to hear what Jonathan, Toke and >>> others think. I want to see if fairness is preserved in this case with >>> sparse flows only. Could flent do this? >> >> Well, sparse flows are (by definition) not building a queue, so it >> doesn't really make sense to talk about fairness for them. How would you >> measure that? >> >> This is also the reason I agree that they shouldn't be counted for host >> fairness calculation purposes, BTW... > > The trick is that we need to keep fairness of the deficit > replenishments, which occur for sparse flows as well as bulk ones, but > in smaller amounts. The number of active flows is presently the > stand-in for this. It's possible to have a host backlogged with > hundreds of new flows which are, by definition, sparse. Right, there's some care needed to ensure we don't get weird behaviour during transients such as flow startup. > I'm still trying to get my head around how the modified code works in > detail. It's possible that a different implementation would either be > more concise and readable, or better model what is actually needed. > But I can't tell until I grok it. Cool, good to know you are on it; I'm happy to wait until you've had some time to form an opinion on this :) -Toke