From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vw0-f43.google.com (mail-vw0-f43.google.com [209.85.212.43]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 11E70200620 for ; Wed, 19 Oct 2011 10:02:44 -0700 (PDT) Received: by vws13 with SMTP id 13so2428830vws.16 for ; Wed, 19 Oct 2011 10:02:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=sender:message-id:date:from:organization:user-agent:mime-version:to :cc:subject:references:in-reply-to:content-type :content-transfer-encoding; bh=G6YDOdzssCaDehoUVhdUwrluccnHa2OCTeavS7Szl0A=; b=fNRucMQiFeFX5VN276mQmjt5fayz0YC/9I8Xu//NV7PqtupBRgsz7FvVa7DWlOEcCJ Jge6zPniUKckRqbIekAjonnuksdMaU5vMnEu0dCpITd8cxc248JdZisIO5y3stgXYK2g L5mZ5txDPHHBfbcsIL6y1Fv8qnUNxllNuN3RI= Received: by 10.52.37.129 with SMTP id y1mr7476777vdj.23.1319043763990; Wed, 19 Oct 2011 10:02:43 -0700 (PDT) Received: from [172.30.45.112] (c-24-63-191-17.hsd1.ma.comcast.net. [24.63.191.17]) by mx.google.com with ESMTPS id l4sm6066931vdv.4.2011.10.19.10.02.42 (version=SSLv3 cipher=OTHER); Wed, 19 Oct 2011 10:02:43 -0700 (PDT) Sender: Jim Gettys Message-ID: <4E9F02B1.9090902@freedesktop.org> Date: Wed, 19 Oct 2011 13:02:41 -0400 From: Jim Gettys Organization: Bell Labs User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:7.0) Gecko/20110923 Thunderbird/7.0 MIME-Version: 1.0 To: Dave Taht Subject: Re: PF_ring and friends: Options for making Linux suck less when capturing packets References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: bloat-devel X-BeenThere: bloat-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: "Developers working on AQM, device drivers, and networking stacks" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 19 Oct 2011 17:02:45 -0000 On 10/19/2011 12:44 PM, Dave Taht wrote: > > Currently I can do tcpdump -i eth1 -s 200 -w /some/usb/stick.cap at > about 1.2 - 2MB/sec before saturating cpu on the wndr3700v2. (MB > =megabyte) > > I can r/w a usb stick at about 8/7 MB/sec. I haven' tried a 'real' > hard disk. > > About 50Mbit/sec I figure covers the 95 percentile of most home users > to their ISP. 100Mbit would be better. Being drop-free would be really > helpful on shorter tests.... > > I was also thinking about an in-kernel module that uses 'splice' to > send the data to a file... as well as the current jit work for bpf, > using netfilter, and various other alternatives. There may be faster USB sticks as well. Certainly, SD cards vary hugely for write performance, and you can buy way faster ones than the "cheap" ones you get. For example: http://www.amazon.com/Patriot-Xporter-Speed-Flash-PEF32GRUSB/dp/B003WUX6RO/ref=sr_1_1?ie=UTF8&qid=1319043694&sr=8-1 is much, much faster than most USB sticks (though most HDD's will still outperform it. - Jim