From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-12-ewr.dyndns.com (mxout-052-ewr.mailhop.org [216.146.33.52]) by lists.bufferbloat.net (Postfix) with ESMTP id 5BEA92E0271 for ; Tue, 15 Mar 2011 18:02:44 -0700 (PDT) Received: from scan-11-ewr.mailhop.org (scan-11-ewr.local [10.0.141.229]) by mail-12-ewr.dyndns.com (Postfix) with ESMTP id 66962932107 for ; Wed, 16 Mar 2011 01:02:42 +0000 (UTC) X-Spam-Score: 0.1 () X-Mail-Handler: MailHop by DynDNS X-Originating-IP: 75.145.127.229 Received: from gw.co.teklibre.org (75-145-127-229-Colorado.hfc.comcastbusiness.net [75.145.127.229]) by mail-12-ewr.dyndns.com (Postfix) with ESMTP id 243349320F7 for ; Wed, 16 Mar 2011 01:02:41 +0000 (UTC) Received: from cruithne.co.teklibre.org (unknown [IPv6:2002:4b91:7fe5:1::20]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "cruithne.co.teklibre.org", Issuer "CA Cert Signing Authority" (verified OK)) by gw.co.teklibre.org (Postfix) with ESMTPS id A0B305EADB for ; Tue, 15 Mar 2011 19:02:40 -0600 (MDT) Received: by cruithne.co.teklibre.org (Postfix, from userid 1000) id 68FD512085F; Tue, 15 Mar 2011 19:02:39 -0600 (MDT) From: d@taht.net (Dave =?utf-8?Q?T=C3=A4ht?=) To: Jonathan Morton Organization: Teklibre - http://www.teklibre.com References: <4D7F4121.40307@freedesktop.org> <20110315175942.GA10064@goldfish> <1300212877.2087.2155.camel@tardy> <20110315183111.GB2542@tuxdriver.com> <29B06777-CC5F-4802-8727-B04F58CDA9E3@gmail.com> <20110315205146.GF2542@tuxdriver.com> <219C7840-ED79-49EA-929D-96C5A6200401@gmail.com> <20110315151946.31e86b46@nehalam> <1300228592.2087.2191.camel@tardy> <1300229578.2565.29.camel@edumazet-laptop> <87fwqo54n7.fsf@cruithne.co.teklibre.org> <823E2A7B-4F46-4159-8029-BD3B075CC4CE@gmail.com> Date: Tue, 15 Mar 2011 19:02:39 -0600 In-Reply-To: <823E2A7B-4F46-4159-8029-BD3B075CC4CE@gmail.com> (Jonathan Morton's message of "Wed, 16 Mar 2011 02:49:42 +0200") Message-ID: <87bp1b6fo0.fsf@cruithne.co.teklibre.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Cc: Stephen Hemminger , bloat@lists.bufferbloat.net Subject: Re: [Bloat] Random idea in reaction to all the discussion of TCP flavours - timestamps? X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 16 Mar 2011 01:02:44 -0000 Jonathan Morton writes: > On 16 Mar, 2011, at 1:46 am, Dave T=C3=A4ht wrote: > >>> 1) Wired devices, where we want to push more 10+ Gbps, so we can assume >>> a posted skb is transmitted immediately. Even a basic qdisc can be a >>> performance bottleneck. Set TX ring size to 256 or 1024+ buffers to >>> avoid taking too many interrupts. >>=20 >> To talk to this a bit, the huge dynamic range discrepancy between a >> 10GigE device and what it may be connected to worries me. Some form of >> fair queuing should be applied before the data hits the driver. > > You mean plugging a 10GigE card into a 10Base-T hub? :-D More like 10GigE into a 1Gig switch. Or spewing out the entire contents of a stream to one destination across the internet.=20 > > For less ridiculous topologies, the queues would mostly be in other devic= es. But you flood them less with fair queuing, which was my point. Nagle: http://en.wikipedia.org/wiki/Fair_queuing > - Jonathan > --=20 Dave Taht http://nex-6.taht.net