From owner-freebsd-stable@FreeBSD.ORG Mon May 5 23:18:11 2008 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A5A5A1065685 for ; Mon, 5 May 2008 23:18:11 +0000 (UTC) (envelope-from ghelmer@palisadesys.com) Received: from cetus.palisadesys.com (cetus.palisadesys.com [205.237.115.21]) by mx1.freebsd.org (Postfix) with ESMTP id 57B158FC2C for ; Mon, 5 May 2008 23:18:11 +0000 (UTC) (envelope-from ghelmer@palisadesys.com) Received: from magellan.palisadesys.com (serverwatch [172.16.1.98]) by cetus.palisadesys.com (8.14.1/8.14.1) with ESMTP id m45Md6vd022602 for ; Mon, 5 May 2008 17:39:06 -0500 (CDT) (envelope-from ghelmer@palisadesys.com) Received: from [127.0.0.1] (cetus.palisadesys.com [205.237.115.21]) (authenticated bits=0) by magellan.palisadesys.com (8.14.1/8.14.1) with ESMTP id m45Md3nE061266 for ; Mon, 5 May 2008 17:39:04 -0500 (CDT) (envelope-from ghelmer@palisadesys.com) Message-ID: <481F8C9B.1080508@palisadesys.com> Date: Mon, 05 May 2008 17:39:23 -0500 From: Guy Helmer User-Agent: Thunderbird 2.0.0.14 (Windows/20080421) MIME-Version: 1.0 To: freebsd-stable@freebsd.org Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-3.0 (magellan.palisadesys.com [205.237.115.20]); Mon, 05 May 2008 17:39:04 -0500 (CDT) X-Palisade-MailScanner-Information: Please contact the ISP for more information X-Palisade-MailScanner: Found to be clean X-Palisade-MailScanner-SpamCheck: not spam (whitelisted), SpamAssassin (not cached, score=-3.799, required 6, ALL_TRUSTED -1.80, BAYES_00 -2.60, J_CHICKENPOX_32 0.60) X-Palisade-MailScanner-From: ghelmer@palisadesys.com Subject: Puzzling VM behavior in 6.3 X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 05 May 2008 23:18:11 -0000 I'm trying to track down a performance regression in a memory-hungry application that seems to be related to switching from FreeBSD 6 as of 2007-01-04 (6.2-ish) to a checkout as of 2007-10-04 (6.3-ish). With these two systems running identical software under load side-by-side on identical hardware, we've observed that the disk is busier on the 6.3 system under the same load, but there shouldn't be much file activity other than logging and the swap usage stays at 0. In trying to track this down, we've found the most significant differences are in statistics from parts of the VM system. A partial snapshot of "systat -vm" shows this: 6-STABLE 2007-10-04 sample Mem:KB REAL VIRTUAL VN PAGER SWAP PAGER Tot Share Tot Share Free in out in out Act 2174196 16428 2489520 29168 166416 count All 2340816 28304 6887896 45636 pages 6-STABLE 2007-01-04 sample Mem:KB REAL VIRTUAL VN PAGER SWAP PAGER Tot Share Tot Share Free in out in out Act 2092808 15184 2439012 25424 202272 count All 3949748 20856157408972 34392 pages We've also noticed large differences in some sysctl vm stats: 6-STABLE 2007-01-04 6-STABLE 2007-10-04 vm.stats.vm.v_forkpages: 660926510 1607169036 vm.stats.vm.v_pdpages: 608941 1793198 Does this information give anyone a clue as to where I should look next? Thanks for any help, Guy -- Guy Helmer, Ph.D. Chief System Architect Palisade Systems, Inc.