From owner-freebsd-acpi@FreeBSD.ORG Fri Sep 18 16:13:05 2009 Return-Path: Delivered-To: freebsd-acpi@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 1F8B8106568B; Fri, 18 Sep 2009 16:13:05 +0000 (UTC) (envelope-from mavbsd@gmail.com) Received: from mail-ew0-f208.google.com (mail-ew0-f208.google.com [209.85.219.208]) by mx1.freebsd.org (Postfix) with ESMTP id 2CD828FC19; Fri, 18 Sep 2009 16:13:03 +0000 (UTC) Received: by ewy4 with SMTP id 4so598710ewy.36 for ; Fri, 18 Sep 2009 09:13:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:sender:message-id:date:from :user-agent:mime-version:to:cc:subject:references:in-reply-to :x-enigmail-version:content-type:content-transfer-encoding; bh=dvVQ4I1Y6M6sm3XLPKPfWsvbtQ+SuPFsA/pk6KxOxXI=; b=fS+LbPGdUGCEfNiDtLaayFkhT7pN640D1qidDT610oaL9gsX7Q2XRTILyoexUjq254 MbzJ995NlDCbCpSevPJ/0wtWYnGv3AdeiIljcBTBhXe6/a6ZSJajYHJeDlXFSp7NHij0 5nZBES6kG6Vew2nsbA+twxXhNVWr427HxAa9I= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:x-enigmail-version:content-type :content-transfer-encoding; b=kb81Dz64Ss9w23N4ttzGAl+EN3WbRQcLZ5O2HtzfUJnn1wc2S6YISXpdyS3Tts6wYy D7QKPyQjJZCbE7rDOXhYXc3WRGE68/YoMehouiyi3tBjTqQPcRwqsWJC5h1Id5yA+d5+ AJbUn1xa9vVoFe28LXo/6g8SVsjBgidWRt/LE= Received: by 10.211.131.34 with SMTP id i34mr2225687ebn.35.1253288891537; Fri, 18 Sep 2009 08:48:11 -0700 (PDT) Received: from mavbook.mavhome.dp.ua (lapwing-gw-1.csx.cam.ac.uk [131.111.1.66]) by mx.google.com with ESMTPS id 10sm5171051eyz.10.2009.09.18.08.48.10 (version=SSLv3 cipher=RC4-MD5); Fri, 18 Sep 2009 08:48:11 -0700 (PDT) Sender: Alexander Motin Message-ID: <4AB3ABB7.30800@FreeBSD.org> Date: Fri, 18 Sep 2009 18:48:07 +0300 From: Alexander Motin User-Agent: Thunderbird 2.0.0.23 (X11/20090901) MIME-Version: 1.0 To: "b. f." References: In-Reply-To: X-Enigmail-Version: 0.96.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: jkim@FreeBSD.org, freebsd-acpi@FreeBSD.org, brueffer@FreeBSD.org, jhb@FreeBSD.org Subject: Re: acpi(4) corrections, clarifications X-BeenThere: freebsd-acpi@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: ACPI and power management development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 18 Sep 2009 16:13:05 -0000 b. f. wrote: > While this documentation cleanup is going on, I'd like to point out > that acpi(4) could use some improvements: > > (1)In the "SYSCTL VARIABLES" section, under hw.acpi.cpu.cx_lowest, > acpi(4) states "To enable ACPI CPU idling control, > machdep.cpu_idle_hlt must be set to 1". However, apparently only the > pc98 port still uses this OID, while amd64, i386, etc., use something > like machdep.idle=hlt, so this remark should be changed. And in any > case, is this statement correct? Can't idling now be used with other > values of machdep.idle, like mwait, mwait_hlt, amdc1e, hlt, and acpi? > > (2)Under the "BUGS" section, acpi(4) states: > > "The acpi CPU idle power management drive conflicts with the local > APIC (LAPIC) timer. Disable APIC mode with hint.apic.0.disabled or do > not use the C2 and C3 states if APIC mode is enabled." > > However, mav@, in his recent series of recommendations on > power-saving, advocated the use of hints like hint.apic.0.clock="0" > instead. Is simply turning off the timer sufficient to use the deeper > sleep states, or must all of the local apic be disabled? Some > machines won't boot with hint.apic.0.disabled, so it would be useful > to determine whether this is really necessary. It is enough to disable APIC timer to use C2/C3. No need to disable whole APIC. There were some objections that legacy timers may not route their interrupts properly on some new systems, but I am not sure whether disabling whole APIC help them somehow, but SMP it kill definitely. -- Alexander Motin