From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-x22b.google.com (mail-lf0-x22b.google.com [IPv6:2a00:1450:4010:c07::22b]) (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 04D253B2A4 for ; Thu, 26 Apr 2018 10:42:06 -0400 (EDT) Received: by mail-lf0-x22b.google.com with SMTP id o123-v6so28553658lfe.8 for ; Thu, 26 Apr 2018 07:42:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=idw1ueqHrL2r+1kzzCtz1hAIMj0sIU4POgo5g6OkVx8=; b=lNELLVaN7EdKgM/s7uFzOwYXrsd488Zaps6ZHPJeccUEiL3Q/RhOZQznT1Rizt3jB7 HU5a2Gw1XZFumpvnx/couYV59yF7EtHNh3LSRwojT1bgbhG90IXq0HEypypY+Z5TKuTU l3Zd4OQrYN7BuhI2i7enaQfxN+Zn883BFPdWJClfSyWH8P7byYpBi1IYB2tQgq9IeWx2 HsQL51b1TcJp6WFvUKTPiuzSWC1eIK6aGIUExf0+dvHVQDiFdap0fUOYGzK5PdglQvr9 XFZ2e9T/Z8L2KMLiDohPlo38sieOV5pkGyTqBeBIoYwiq8KJOPsCkyv0hxfCL8RCWYDD sFjw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=idw1ueqHrL2r+1kzzCtz1hAIMj0sIU4POgo5g6OkVx8=; b=Z2Hsz1txxQtbmV3nDZZz8lww7M5bdjmPA/rMl0BqQ+l4f2akKeQUIsB3t7juFSjjBr /qAl+QCyoVH3/urF4/bHc9HzyXk/+OpVABMNm5f0xIyoh79bhP5Lr5SjA9CiZ0eHE4X6 KR8tPu/s4++Ran5p1qIsTPCollQ5Byrq+IB4Jma+Tlo8y2Nnpaia/HudO9sajh2gztb0 tvHMFPYan6sBgKokJnHGGWwXYq6ulZvzl5t99k7w1fT/EGMvnvUNMzwPbpu47vOrciRW bGZ1Bxatjw68mVo8bz7sb0TbmD2QKPq++vk9ePenPwbDM2Nw/wgoxxBrWCHHVuJfvaVy qTSw== X-Gm-Message-State: ALQs6tAGtmRQWfjYD7CoADwTEURAOFcphPRTCfLWX8yRGHXplOG74Xie 36GvZ1njO9cNcpM2wx/lRXw= X-Google-Smtp-Source: AIpwx48APKbqS/+m8C4mEr1NYO3skW6BXMyrxyCjQpfJVWXY3RF3eyccyA9snWDdQLW1FhG2mOVZAg== X-Received: by 10.46.45.10 with SMTP id t10mr22310337ljt.110.1524753725908; Thu, 26 Apr 2018 07:42:05 -0700 (PDT) Received: from [192.168.239.216] (83-245-234-255-nat-p.elisa-mobile.fi. [83.245.234.255]) by smtp.gmail.com with ESMTPSA id m4-v6sm4442673lfg.69.2018.04.26.07.42.04 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 26 Apr 2018 07:42:05 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 11.3 \(3445.6.18\)) From: Jonathan Morton In-Reply-To: <51A5A6AB-4B1C-4795-8136-9EB63E59598B@gmx.de> Date: Thu, 26 Apr 2018 17:42:03 +0300 Cc: Kevin Darbyshire-Bryant , "cake@lists.bufferbloat.net" Content-Transfer-Encoding: quoted-printable Message-Id: <79A11608-89FF-4353-822A-8A31D6FAC891@gmail.com> References: <87vacf3th7.fsf@toke.dk> <46C6A124-61F3-4503-B310-C55D46597EED@gmail.com> <51A5A6AB-4B1C-4795-8136-9EB63E59598B@gmx.de> To: Sebastian Moeller X-Mailer: Apple Mail (2.3445.6.18) Subject: Re: [Cake] CAKE upstreaming - testers wanted, ACK filtering rescuers needed 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: Thu, 26 Apr 2018 14:42:07 -0000 > I really liked you initial idea to make the threshold when to segment = a superpacket based on the duration that packet would hogg the = wire/shaper, as that gives an intuitive feel for the worst case = inter-flow latency induced. Especially this would allow on many links = intermediate sized superpackets to survive fine while turning 64K = "oil-tankers" into a fleet of speedboats ;). This temporal threshold = would also automatically solve the higher bandwdth cases elegantly. What = was the reason to rip that out again? It probably had something to do with needing to scale that threshold = with the number of active flows, which isn't necessarily known at = enqueue time with sufficient accuracy to be relevant at dequeue, in = order to be able to guarantee a given peak inter-flow induced latency. = Unconditional segmentation made the question easy and didn't seem to = have very much effect on the CPU (at the link rates we were targeting). It might still be reasonable to assume the number of active flows won't = change *much* between enqueue and dequeue. So then we could set the = threshold at, say, half the Codel target divided by the number of active = flows plus one. - Jonathan Morton