From owner-freebsd-questions@FreeBSD.ORG Sun Oct 10 20:49:33 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 12341106566C for ; Sun, 10 Oct 2010 20:49:33 +0000 (UTC) (envelope-from bf1783@googlemail.com) Received: from mail-ew0-f54.google.com (mail-ew0-f54.google.com [209.85.215.54]) by mx1.freebsd.org (Postfix) with ESMTP id 9C8A58FC08 for ; Sun, 10 Oct 2010 20:49:32 +0000 (UTC) Received: by ewy27 with SMTP id 27so1428314ewy.13 for ; Sun, 10 Oct 2010 13:49:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:mime-version:received:received:reply-to:date :message-id:subject:from:to:cc:content-type; bh=uRS1jG6DesPy0GwI7qwhiKr/97h733wVesfrxJ/8LNk=; b=LEh7nQGm3bq4Rj7i9ZDtuKX1QbFfdeKgmcZREamqVZcfaJxza7TxIJZ4kjEHu0R98e 0r9YrlFfQaen4kxhpSErxCbwiv8YFnfZeacTffHjSHfKxjvSLl3zOVy5oI5j+Ch33ru0 14l/wtYAIJIsr2sTcqoGYRXdvZj7Y+oUcMiCg= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=mime-version:reply-to:date:message-id:subject:from:to:cc :content-type; b=MY+C5fLCtiUOXLoRp3zp1C64wl4cNrA672RUGleZJsvOrPmLS3wmjzoNeyh0SsP3V8 65ijz0x4x93l+v/IIMWaQJdG0olT6nP8Z4qq4SWJ/yUdq7D1UCI1ph7joHPYs/PQ6Zax txvEklQ9fU7URRK5vZ36/kNh7DivYfgydjb7s= MIME-Version: 1.0 Received: by 10.213.104.132 with SMTP id p4mr834497ebo.8.1286743770967; Sun, 10 Oct 2010 13:49:30 -0700 (PDT) Received: by 10.14.47.14 with HTTP; Sun, 10 Oct 2010 13:49:30 -0700 (PDT) Date: Sun, 10 Oct 2010 20:49:30 +0000 Message-ID: From: "b. f." To: Bruce Cran Content-Type: text/plain; charset=ISO-8859-1 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 Reply-To: bf1783@gmail.com List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 10 Oct 2010 20:49:33 -0000 >I recently upgraded to HEAD on my VIA EPIA C3 box, and had thought about >trying out the new one-shot timer mode. Reading mav@'s email it seems that >since it doesn't have LAPIC or HPET timers it won't work. However I thought I >should still get power savings by using higher Cx levels, but setting >hw.acpi.cpu.cx_lowest to C3 I'm only seeing 0.8% time spent in C2 mode, the >rest being in C1. The CPU's idle so I don't understand why it's not going into >deeper sleep modes. Is this likely to just be an ACPI bug? If it has an i8254, that can also be used in one-shot mode if hint.attimer.0.timecounter=0 is used, since r212778. 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. Did you follow some of the other recommendations to allow more sleeping, like at: http://wiki.freebsd.org/TuningPowerConsumption ? Or apply mav's extra patch to further reduce interrupts: http://people.freebsd.org/~mav/tm6292_idle.patch ? b.