From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-x241.google.com (mail-lf0-x241.google.com [IPv6:2a00:1450:4010:c07::241]) (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 8CCCF3B29E for ; Thu, 2 Mar 2017 19:02:55 -0500 (EST) Received: by mail-lf0-x241.google.com with SMTP id r36so6871922lfi.0 for ; Thu, 02 Mar 2017 16:02:55 -0800 (PST) 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=N+S/P8B+JXultLNNEeKG5/yd0FccR9s8TUwd3t5QOaY=; b=R4cKULLMT7+bOFpjyUqDzlhj/vtFXHtkonRDNz3cAREKMmEcjeh03kZ8UB7u6n7+ZL GDGky6jEzXV+o35ZRz9DvifUODjm7ntGp5qTODi7/p4sXZMTFIa7s9A5pkWq+UPhCSTz RhEfDAHd6jXwESETG7b96PqaUQJKCyq3QqMA3HMf3TQhwvfg3m1FRGQRtf+L0AWrohql WDk7g2ZYvNOtRh3lUKT4FBrZu28Myi39OwXgnDWaXRQmS3ymZ9NW6CQ9mzgjRSCrCyE0 p0Qpdpa0TIu6uv8pWNb7hB+CAJWIl38Rl/x1Qzb8ZmsYxFn/T5syfC+28OfA7acY8s0Z CpAA== 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=N+S/P8B+JXultLNNEeKG5/yd0FccR9s8TUwd3t5QOaY=; b=OLp3uPu4B2F49kc41I6UlMcbiFYmwiWExcA7bcEz6wuR+Yllj3ej5FQ4fugiAMugwX j9msPIpeYW1WlcNfhsuWi1vBVgSCeqw49OaJffUJu5J6g4tnDhzuCIWV8Z5ENKIBRKHK yAHs+DHhA03ax/2rM3z6Gbqob0ZF0ltdlSOns/du5pMEjedn/1xJsP0ujZK7/Vv1xPiO n+W0hA3PZP9n9a/r2hw3jm+2b/hWErQ2nZm9tpBU+JsijRvPMBZQzL/VHDM9oGCM0zA7 1cucWwtoWac5dv2VgdvGFuKbdMICyUHbB6KmMKih5M28E+fAffMLvp6h25Dm6uCkQSXf 07Jg== X-Gm-Message-State: AMke39lWpd7cggTLAlk9BXrtta2cVVg1kCuL4U3L5EV6hxotJlXsT9G+MK0EN2a+gDrBnw== X-Received: by 10.25.196.21 with SMTP id u21mr5259036lff.81.1488499374476; Thu, 02 Mar 2017 16:02:54 -0800 (PST) Received: from [192.168.100.16] (37-219-206-78.nat.bb.dnainternet.fi. [37.219.206.78]) by smtp.gmail.com with ESMTPSA id h23sm2039139lji.34.2017.03.02.16.02.53 (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 02 Mar 2017 16:02:53 -0800 (PST) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) From: Jonathan Morton In-Reply-To: Date: Fri, 3 Mar 2017 02:02:51 +0200 Cc: =?utf-8?Q?Dave_T=C3=A4ht?= , cake@lists.bufferbloat.net, lede-dev@lists.infradead.org Content-Transfer-Encoding: quoted-printable Message-Id: <98E899EF-5E66-42CC-88AA-79FA80A4F228@gmail.com> References: <07479F0A-40DD-44E5-B67E-28117C7CF228@gmx.de> <1488400107.3610.1@smtp.autistici.org> <2B251BF1-C965-444D-A831-9981861E453E@gmx.de> <1488484262.16753.0@smtp.autistici.org> To: John Yates X-Mailer: Apple Mail (2.3124) Subject: Re: [Cake] [LEDE-DEV] Cake SQM killing my DIR-860L - was: [17.01] Kernel: bump to 4.4.51 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, 03 Mar 2017 00:02:55 -0000 > On 3 Mar, 2017, at 01:55, John Yates wrote: >=20 > The virtue of a prime number of buckets is that when you mod > your 32-bit hash value to get a bucket index you harvest _all_ > of the entropy in the hash, not just the entropy in the bits you > preserve. True, but you incur the cost of a division, which is very much = non-trivial on ARM CPUs, which are increasingly common in CPE. - Jonathan Morton