From owner-freebsd-stable@FreeBSD.ORG Fri May 12 22:14:18 2006 Return-Path: X-Original-To: stable@freebsd.org Delivered-To: freebsd-stable@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 69A5016A5C4 for ; Fri, 12 May 2006 22:14:18 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from pi.codefab.com (pi.codefab.com [199.103.21.227]) by mx1.FreeBSD.org (Postfix) with ESMTP id 111D043D45 for ; Fri, 12 May 2006 22:14:18 +0000 (GMT) (envelope-from cswiger@mac.com) Received: from localhost (localhost [127.0.0.1]) by pi.codefab.com (Postfix) with ESMTP id 78BEB5CE2; Fri, 12 May 2006 18:14:17 -0400 (EDT) X-Virus-Scanned: amavisd-new at codefab.com Received: from pi.codefab.com ([127.0.0.1]) by localhost (pi.codefab.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id MRtQzc8hPHD0; Fri, 12 May 2006 18:14:16 -0400 (EDT) Received: from [192.168.1.251] (pool-68-160-235-217.ny325.east.verizon.net [68.160.235.217]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by pi.codefab.com (Postfix) with ESMTP id AFD3B5C9C; Fri, 12 May 2006 18:14:16 -0400 (EDT) Message-ID: <446508B6.4000305@mac.com> Date: Fri, 12 May 2006 18:14:14 -0400 From: Chuck Swiger User-Agent: Thunderbird 1.5.0.2 (Windows/20060308) MIME-Version: 1.0 To: Ivan Voras References: <4464FA8D.5060309@fer.hr> In-Reply-To: <4464FA8D.5060309@fer.hr> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: stable@freebsd.org Subject: Re: pagezero again 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: Fri, 12 May 2006 22:14:18 -0000 Ivan Voras wrote: > Some time ago I reported that pagezero kernel thread sometime takes > (what seems to me) a too large chunk of available CPU (30%) on a very > busy web server. There were no replies :( Since then, I've > reconfigured apache to use PHP as a fastcgi module and the problem > seems to have gotten worse - now it *always* takes ~25-30% CPU, and my > "System" time stat shows it (its almost always ~30%). > > From what I can understand, pagezero thread fills kernel's pool of > zeroed pages. This looks non-threteaning, but what would cause such > high demand of zeroed pages on my system? Generally, a whole bunch of processes that are demanding a lot or memory and/or swapping would do it. What does "vmstat 1" look like...? -- -Chuck