From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.15.18]) (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 03E713B29E for ; Wed, 22 Nov 2017 08:51:48 -0500 (EST) Received: from [192.168.250.101] ([134.76.241.253]) by mail.gmx.com (mrgmx002 [212.227.17.190]) with ESMTPSA (Nemesis) id 0LeMij-1evr7m12FR-00q8H0; Wed, 22 Nov 2017 14:51:47 +0100 Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 10.3 \(3273\)) From: Sebastian Moeller In-Reply-To: Date: Wed, 22 Nov 2017 14:51:46 +0100 Cc: Cake List Content-Transfer-Encoding: quoted-printable Message-Id: <5043A111-A21A-4511-A32D-33398253E3C2@gmx.de> References: <107CB879-B196-40F1-A7C2-08B963B7A835@gmail.com> To: Pete Heist X-Mailer: Apple Mail (2.3273) X-Provags-ID: V03:K0:HsIT9zTnPjIr06JAIiFcfs2U4L0FgpXvGcKvy4pVuwD4bL2pxTq u3Au8Q0PaLNVR2Uu69Vsfhe9y4KaTUbCmoMQ6yJgrpQpxL2YIAUC+ft2E//VrNxQTfhHBR8 nAscbgebWyjaX1gHOr3QpE13tPds5Vd0PuDRVOPSKjYnmjoEvfepaBGkm6ZG2+ngkVO4q2x EFBZzHdEUu0jEMiNnUGDA== X-UI-Out-Filterresults: notjunk:1;V01:K0:6DhJ168jzCk=:DfxIUa4sX3rE1vIypc0hUd p7vDXQ5dg97+edaHXdFc8NAqeSN2gc+55vbmjHSoGChQrvPgN8HsNid63DMi2yzPICWWC0jM9 JlklTZO+Ia8QtZZIS9MMenW4lIpoGpUbYea0gR3qsw4kqdgYbzBPpVqnqWd8SOm6DGL6peMgy rL4ZmEHno4//ykw/s4V/jkFJtSQD3YmJa3ab5q6gT+Pyj0gHRe9yTiGoro2eGMtIBuPKN4ffA ZeTZb98taoO/fU7Ve9SiCNNMY3F+smP/Bp2j7S3VyEVGHFk1MX992rkb6z9PqssiHeFsmx2Gl 8nJXP0/ZOtWxpcR1UIMmhqPjPWeZRs2avfLGrvWuysnkgrij/NWwFG1aTC9j+9PH2zBgD9S5V 1fVys3W0S2Gmh4dsocwDyXHS9dmZ8ZQr7FLc/J+nD+Zs/aDXzUhkrAb9N4V/cQL6Z3JRFUf2O dC9tWo0bpyKMdqnY4EycdmR5JuTYQC+cklGXMWKnXdm4ceV/9oA1l7hTPSTGvPSLh0O5kTto6 okjLSLM6skgSjdrh/Bxc/kCeFplXyQP73O385E1lhSvHdgjvu2wnernsjmYP8QYahGgGxsPhV 7VcOR64MvDyCbe0tMw+VdE2rM3t8CjJNAHmsVU1BPx2xAnNp0/4YgK10Cb8ZgrPNCNgOw9X7y +xRvBav6rlkIdSfHhmgXcvkFq7QUTenFsYg4FEsTzUKP/VP3HIlpPXpR/sWbi1qWNMUBBuHFT mowg8msUtP3ZLxXJdNBJzdYmxebccBR6bDd7Gi3rLgZY1Yk6qBK6P62ly9sy9JXbyJNZLWQ+c 7/xo3OuR7wyTMsWfdcTYp0Cp7B24qjkvSSyOBOeGUVUNC0RwPc= Subject: Re: [Cake] small cake_hash optimization? 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: Wed, 22 Nov 2017 13:51:49 -0000 Hi Pete, [NITPICK] please note that "cake 950mbit " will only assume 14 bytes overhead = which does not reflect what is really happening on ethernet Gb Ethernet: 7 Byte Preamble + 1 Byte start of frame delimiter (SFD) + 12 Byte inter = frame gap (IFG) + 4 Byte Frame Check Sequence (FCS) + 6 (dest MAC) + 6 = (src MAC) + 2 (ethertype) 7 + 1 + 12 + 4 + 6 + 6 + 2 =3D 38 bytes so the actual consumed bandwidth for MTU 1500 packets will be: 950 * ((1538)/(1514)) =3D 965.06 Mbps so below a MTU of (14 * (1000/950) - 38) / (1 - (1000/950)) =3D 442 Byte = the cake shaper will not avoid filling the ethernet NIC's queues (which = might not be a bid issue with BQL). I guess my point is when shaping ethernet be sure to add "overhead 64 = mpu 84" to your cake invocation to actually account for the link layer = properties. [/NITPICK] Best Regards > On Nov 22, 2017, at 13:37, Pete Heist wrote: >=20 >=20 >> On Nov 22, 2017, at 11:06 AM, Pete Heist wrote: >>=20 >> I=E2=80=99ve not done any testing on what the real impact of this = change would be, or even if it breaks something. >=20 > Ok, at least a little crude testing with sar: >=20 > = https://docs.google.com/spreadsheets/d/1LKoq5NaswuHm9H1atXoZA1AhNDg6L4UYS3= Pn5lCsb1I/edit#gid=3D0 >=20 > ~10% less cake CPU at GigE in this case? What=E2=80=99s a better tool = for timing kernel module functions? >=20 > Would really need to test if host fairness still works, otherwise this = is irrelevant=E2=80=A6 >=20 > _______________________________________________ > Cake mailing list > Cake@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/cake