From owner-freebsd-stable@FreeBSD.ORG Sat Dec 17 16:23:12 2011 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 10D45106566C; Sat, 17 Dec 2011 16:23:12 +0000 (UTC) (envelope-from jhellenthal@gmail.com) Received: from mail-iy0-f182.google.com (mail-iy0-f182.google.com [209.85.210.182]) by mx1.freebsd.org (Postfix) with ESMTP id BB43A8FC14; Sat, 17 Dec 2011 16:23:11 +0000 (UTC) Received: by iadj38 with SMTP id j38so3006042iad.13 for ; Sat, 17 Dec 2011 08:23:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to; bh=Y7W6wRVchrTIFv36x537CgJKSyfJxmryT+wnBB3bRi8=; b=C7XDZsFvQqTZnDjsuMhnEANRvJsbPJmnZNnyQ9SY3W2AUvAPLyiGb5huGVJvlJvsh3 nW7/RDNl3clt9PX/Vn8BaO9NAvYQho2j33w6H5wU46cKqc3EV3pNzrCiGk0kvbDgsvI0 S/AcHs8n1kRDsQtLeLLeBK/7Hdt9M7WnTJcG0= Received: by 10.50.207.40 with SMTP id lt8mr16447665igc.43.1324138991258; Sat, 17 Dec 2011 08:23:11 -0800 (PST) Received: from DataIX.net (24-247-9-230.dhcp.aldl.mi.charter.com. [24.247.9.230]) by mx.google.com with ESMTPS id wn9sm9076866igc.6.2011.12.17.08.23.09 (version=TLSv1/SSLv3 cipher=OTHER); Sat, 17 Dec 2011 08:23:10 -0800 (PST) Sender: Jason Hellenthal Received: from DataIX.net (localhost [127.0.0.1]) by DataIX.net (8.14.5/8.14.5) with ESMTP id pBHGN7uo021589 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sat, 17 Dec 2011 11:23:07 -0500 (EST) (envelope-from jhell@DataIX.net) Received: (from jhell@localhost) by DataIX.net (8.14.5/8.14.5/Submit) id pBHGN2mX021588; Sat, 17 Dec 2011 11:23:02 -0500 (EST) (envelope-from jhell@DataIX.net) Date: Sat, 17 Dec 2011 11:23:02 -0500 From: Jason Hellenthal To: Doug Barton Message-ID: <20111217162302.GB3875@DataIX.net> References: <4EEA5DD0.1040009@FreeBSD.org> <20111217162029.GA3875@DataIX.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20111217162029.GA3875@DataIX.net> Cc: freebsd-stable@freebsd.org Subject: Re: swi4: clock taking 40% cpu?!? 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: Sat, 17 Dec 2011 16:23:12 -0000 Should also mention the kern.sched may be playing a part in this too. On Sat, Dec 17, 2011 at 11:20:29AM -0500, Jason Hellenthal wrote: > > > On Thu, Dec 15, 2011 at 12:51:28PM -0800, Doug Barton wrote: > > Howdy, > > > > Web server under heavy'ish load (7 on a 2 cpu system) running > > 8.2-RELEASE-p4 i386 I'm seeing this: > > > > PID USERNAME PRI NICE SIZE RES STATE C TIME WCPU COMMAND > > 12 root -32 - 0K 112K WAIT 0 129:01 39.99% {swi4: clock} > > > > Any ideas why the clock should be taking so much cpu? HZ=100 if that > > makes a difference ... > > > > > > Without NTPd running test the following. > > > apply "/usr/bin/time -ph sleep %1" 300 600 900 > > If the results are skewed quite a bit then your system may benefit from a different HZ than what you have set. I have seen systems that require a HZ of 350 and as weird as it sounds NTPd may be tasting the clock too much just to try and keep time. > > -- > ;s =; -- ;s =;