From owner-freebsd-performance@FreeBSD.ORG Tue Jan 3 07:37:40 2012 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 4F10C1065670 for ; Tue, 3 Jan 2012 07:37:40 +0000 (UTC) (envelope-from dieterbsd@engineer.com) Received: from mailout-us.gmx.com (mailout-us.gmx.com [74.208.5.67]) by mx1.freebsd.org (Postfix) with SMTP id EC1B78FC08 for ; Tue, 3 Jan 2012 07:37:39 +0000 (UTC) Received: (qmail 25271 invoked by uid 0); 3 Jan 2012 07:37:38 -0000 Received: from 67.206.183.46 by rms-us008.v300.gmx.net with HTTP Content-Type: text/plain; charset="utf-8" Date: Tue, 03 Jan 2012 02:37:34 -0500 From: "Dieter BSD" Message-ID: <20120103073736.218240@gmx.com> MIME-Version: 1.0 To: freebsd-performance@freebsd.org X-Authenticated: #74169980 X-Flags: 0001 X-Mailer: GMX.com Web Mailer x-registered: 0 Content-Transfer-Encoding: 8bit X-GMX-UID: F9VwbyQ03zOlNR3dAHAhDZ5+IGRvb8Cg Subject: Re: cmp(1) has a bottleneck, but where? 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: Tue, 03 Jan 2012 07:37:40 -0000 >>>> Task: cp(1) a several-GB file from one drive to another, >>>> then run cmp(1) to verify. Cp runs as expected, but >>>> cmp runs slower than expected. Neither the disks >>>> nor the cpu is maxed out. Local drives, no network >>>> involved. Machine is otherwise idle. >>> >>> 1. How are you running cmp? >>> 2. Why do you claim cmp is the bottleneck? Is it spinning the CPU? >> >> cmp big_file /other_disk/big_file >> >> Cmp is running slower than it should. It isn't cpu bound ( 67.5%Idle ) >> but it isn't disk bound either. Seems like it should be one or the >> other. > >    What gets output on the console when you do CTRL-T? load: 0.59  cmd: cmp 93304 [vnread] 56.99r 8.50u 3.80s 23% 720k load: 0.59  cmd: cmp 93304 [vnread] 57.68r 8.60u 3.85s 22% 720k load: 0.54  cmd: cmp 93304 [vnread] 60.69r 9.03u 4.12s 22% 780k load: 0.54  cmd: cmp 93304 [runnable] 63.79r 9.58u 4.26s 22% 720k load: 0.58  cmd: cmp 93304 [runnable] 68.33r 10.28u 4.62s 21% 788k load: 0.53  cmd: cmp 93304 [runnable] 71.92r 10.78u 4.94s 23% 720k load: 0.53  cmd: cmp 93304 [vnread] 72.31r 10.84u 4.96s 21% 780k load: 0.44  cmd: cmp 93304 [vnread] 198.84r 30.64u 14.36s 23% 720k