From owner-freebsd-performance@FreeBSD.ORG Sat Oct 17 16:58:46 2009 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 282E3106566B for ; Sat, 17 Oct 2009 16:58:46 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from asmtpout012.mac.com (asmtpout012.mac.com [17.148.16.87]) by mx1.freebsd.org (Postfix) with ESMTP id 100098FC14 for ; Sat, 17 Oct 2009 16:58:45 +0000 (UTC) MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Received: from [10.152.145.215] (72-165-115-225.dia.static.qwest.net [72.165.115.225]) by asmtp012.mac.com (Sun Java(tm) System Messaging Server 6.3-8.01 (built Dec 16 2008; 32bit)) with ESMTPSA id <0KRO00CSE1PBST00@asmtp012.mac.com> for freebsd-performance@freebsd.org; Sat, 17 Oct 2009 08:58:25 -0700 (PDT) Message-id: <0D9BF9F3-FDA1-4111-9E6C-733E1FD972F5@mac.com> From: Chuck Swiger To: Steve Dong In-reply-to: <000001ca4f3c$78dc3550$6501a8c0@china.huawei.com> Date: Sat, 17 Oct 2009 08:58:23 -0700 References: <78DB4AE8EF5F4A1EBD3992D7404B2725@china.huawei.com> <4831593800614E6796A45F20BA4B818E@china.huawei.com> <001301ca4e23$b96e35b0$3322c10a@china.huawei.com> <001c01ca4e24$f10f6e70$3322c10a@china.huawei.com> <20091016075336.03eb17f2.wmoran@collaborativefusion.com> <000001ca4f3c$78dc3550$6501a8c0@china.huawei.com> X-Mailer: Apple Mail (2.936) Cc: freebsd-performance@freebsd.org Subject: Re: Comparison of FreeBSD/Linux TCP Throughput performance X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 17 Oct 2009 16:58:46 -0000 Hi, Steve-- On Oct 17, 2009, at 8:14 AM, Steve Dong wrote: > If there's a better/lighter way to show these graphics, I'd like to > know. Sure-- put 'em on a webserver somewhere, and put links to them in your email to this mailing list. If you wanted to do even better than that, set up a simple webpage describing what you are doing in your comparison, have a link to the dmesg/boot output for each platform as a .txt file and a description of any system tweaks & tuning, have a link that points to a description of the test setup (ie, your ASCII diagram of the switch and 4 machines), then your graphs, then the raw data (or links to it, depending). You can then throw in netstat -s output, or NIC driver stats from sysctl, or switch stats, etc-- anything else that adds useful context. There are a fair number of posts in the list archives which describe how to benchmark reliably, and the people who are most likely to be making code changes to FreeBSD also tend to like to know whether you've collected enough data, in a controlled fashion, to have an idea as to whether your measurements are reproducible. I'm not a purist, and I believe you can get useful estimations without rigorous testing, but there are others who make the point that if you haven't provided at least a standard deviation, then you haven't collected enough data-- done enough trials-- to determine whether the results are meaningful. (See /usr/src/tools/tools/ministat/README) Of course, you're not obligated to do any of the above, but if you want the effort you've put in to be more useful, consider these a suggestion. Finally, the next step beyond that would be to try tweaking some things, and see what kind of changes you get from that versus the original performance. It might be the case that making a simple tuning change would have a significant difference in performance; if you can identify that, then FreeBSD or Linux developers can use that information to better tune the OS defaults. Regards, -- -Chuck