From owner-freebsd-questions@FreeBSD.ORG Sun Oct 10 21:28:36 2010 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 4988C106566B for ; Sun, 10 Oct 2010 21:28:36 +0000 (UTC) (envelope-from bruce@cran.org.uk) Received: from muon.cran.org.uk (muon.cran.org.uk [IPv6:2a01:348:0:15:5d59:5c40:0:1]) by mx1.freebsd.org (Postfix) with ESMTP id D8DFF8FC0A for ; Sun, 10 Oct 2010 21:28:35 +0000 (UTC) Received: from muon.cran.org.uk (localhost [127.0.0.1]) by muon.cran.org.uk (Postfix) with ESMTP id 0626CE83BF; Sun, 10 Oct 2010 22:28:35 +0100 (BST) Received: from core.nessbank (client-86-31-64-159.midd.adsl.virginmedia.com [86.31.64.159]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by muon.cran.org.uk (Postfix) with ESMTPSA; Sun, 10 Oct 2010 22:28:34 +0100 (BST) From: Bruce Cran To: bf1783@gmail.com Date: Sun, 10 Oct 2010 22:28:33 +0100 User-Agent: KMail/1.13.5 (FreeBSD/9.0-CURRENT; KDE/4.5.1; amd64; ; ) References: In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201010102228.33095.bruce@cran.org.uk> Cc: freebsd-questions@freebsd.org Subject: Re: VIA EPIA 5000 and ACPI Cx levels X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 10 Oct 2010 21:28:36 -0000 On Sunday 10 October 2010 21:49:30 b. f. wrote: > If it has an i8254, that can also be used in one-shot mode if > hint.attimer.0.timecounter=0 is used, since r212778. Thanks, I didn't know about that. After enabling it things are quite different: kern.eventtimer.periodic is now 1, and setting hw.acpi.cpu.cx_lowest=C2 results in 100% time being reported as being spent in C2 mode according to dev.cpu.0.cx_usage - using C3 causes the system to hang. Shouldn't a fully loaded CPU spent more time in C1 state though? When I run a program that results in 0% idle time cx_usage still reports that no time was spent in C1 state. > But for low > values of kern.hz, I've found that periodic mode can result in fewer > interrupts (albeit increased latencies and lower accuracy in > accounting) than one-shot mode, if kern.eventtimer.singlemul=1. As > for the power-saving states, are you using a simple 'sysctl > dev.cpu.0.cx_usage' to find the percentages? If you're doing > something more involved, you may be affecting the measurements. Also, > does the system think that the deeper sleep states are available on > your machine? If so, what are their latencies? If they are high, > they may be used less often, or not at all. I'm just using dev.cpu.0.cx_usage to check the Cx level usage. According to dev.cpu.0.cx_supported, I have: C1/0, C2/90, C3/900 > Did you follow some of > the other recommendations to allow more sleeping, like at: > > http://wiki.freebsd.org/TuningPowerConsumption I haven't done anything extra yet, since I was mainly interested in seeing if one-shot mode worked on this box. I can't use powerd because running at 266MHz (I only have 533 and 266 available) results in too much of a slowdown. -- Bruce Cran