From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-11-ewr.dyndns.com (mxout-044-ewr.mailhop.org [216.146.33.44]) by lists.bufferbloat.net (Postfix) with ESMTP id 71C822E0271 for ; Tue, 15 Mar 2011 17:49:47 -0700 (PDT) Received: from scan-11-ewr.mailhop.org (scan-11-ewr.local [10.0.141.229]) by mail-11-ewr.dyndns.com (Postfix) with ESMTP id 4353F92C612 for ; Wed, 16 Mar 2011 00:49:46 +0000 (UTC) X-Spam-Score: -1.0 (-) X-Mail-Handler: MailHop by DynDNS X-Originating-IP: 74.125.82.171 Received: from mail-wy0-f171.google.com (mail-wy0-f171.google.com [74.125.82.171]) by mail-11-ewr.dyndns.com (Postfix) with ESMTP id D226C92C5BC for ; Wed, 16 Mar 2011 00:49:45 +0000 (UTC) Received: by wyb32 with SMTP id 32so1409502wyb.16 for ; Tue, 15 Mar 2011 17:49:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:subject:mime-version:content-type:from :in-reply-to:date:cc:content-transfer-encoding:message-id:references :to:x-mailer; bh=/dqyqxte1pXjYARJQu75yQKX+cLcTQ66XkeTaxT+m/c=; b=SF6DgtfzjvFp4I9w0/MO2OwxDUJTV/qmp3xB8IL0vNhvw27ph2dbzIxisZK+i3W0Lb Vk1kZhbjxLPsRxQVdYz9hBD22vIAl2Jrb02c5j9cYQEpHRBp0uU8j6T0Ei5RGM6WWbFb cFMDhWbi3+RPIhentBhy3VVF2VegBOaAjR8r4= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:mime-version:content-type:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to:x-mailer; b=kZfSI8P5jIxMmXn8mak5dpttl/59+/OibTWqdL3ttH0iQs6iNiDlAGA9VADL6x2Kd2 y0NOp8S0OuEUaRqMd2wWsvUXFJ6CHP3ON7S4CVVkBKDWYBm4jl1UQ1rRM94jTcB/pgdi mjoAePZ0+C8h/qLTB/RGM2xD5ltoEgrgPdpUg= Received: by 10.216.171.133 with SMTP id r5mr4165540wel.91.1300236585242; Tue, 15 Mar 2011 17:49:45 -0700 (PDT) Received: from [192.168.239.42] (xdsl-83-150-84-172.nebulazone.fi [83.150.84.172]) by mx.google.com with ESMTPS id b54sm241888wer.45.2011.03.15.17.49.44 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 15 Mar 2011 17:49:44 -0700 (PDT) Mime-Version: 1.0 (Apple Message framework v1082) Content-Type: text/plain; charset=iso-8859-1 From: Jonathan Morton In-Reply-To: <87fwqo54n7.fsf@cruithne.co.teklibre.org> Date: Wed, 16 Mar 2011 02:49:42 +0200 Content-Transfer-Encoding: quoted-printable Message-Id: <823E2A7B-4F46-4159-8029-BD3B075CC4CE@gmail.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> To: d@taht.net (=?iso-8859-1?Q?Dave_T=E4ht?=) X-Mailer: Apple Mail (2.1082) 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 00:49:47 -0000 On 16 Mar, 2011, at 1:46 am, Dave T=E4ht 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 For less ridiculous topologies, the queues would mostly be in other = devices. - Jonathan