From owner-freebsd-mobile@FreeBSD.ORG Mon May 11 23:13:38 2009 Return-Path: Delivered-To: freebsd-mobile@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id CAE1B10656E2; Mon, 11 May 2009 23:13:38 +0000 (UTC) (envelope-from mav@FreeBSD.org) Received: from cmail.optima.ua (cmail.optima.ua [195.248.191.121]) by mx1.freebsd.org (Postfix) with ESMTP id D33CB8FC1B; Mon, 11 May 2009 23:13:37 +0000 (UTC) (envelope-from mav@FreeBSD.org) X-Spam-Flag: SKIP X-Spam-Yversion: Spamooborona-2.1.0 Received: from [66.135.97.2] (account mav@alkar.net HELO mavbook.mavhome.dp.ua) by cmail.optima.ua (CommuniGate Pro SMTP 5.2.9) with ESMTPSA id 242454679; Tue, 12 May 2009 02:13:35 +0300 Message-ID: <4A08B10E.4040702@FreeBSD.org> Date: Tue, 12 May 2009 02:13:18 +0300 From: Alexander Motin User-Agent: Thunderbird 2.0.0.21 (X11/20090405) MIME-Version: 1.0 To: "Paul B. Mahol" References: <49FE1826.4060000@FreeBSD.org> <4A07BC4D.7080604@freebsd.org> <4A081868.6010906@FreeBSD.org> <3a142e750905111308o62a11c8em5465ea9aa1cfaebc@mail.gmail.com> In-Reply-To: <3a142e750905111308o62a11c8em5465ea9aa1cfaebc@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: FreeBSD acpi , FreeBSD-Current , freebsd-mobile@freebsd.org Subject: Re: Fighting for the power. X-BeenThere: freebsd-mobile@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Mobile computing with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 11 May 2009 23:13:39 -0000 Paul B. Mahol wrote: > On 5/11/09, Alexander Motin wrote: >> Tim Kientzle wrote: >>> I started to try the "hint.apic.0.clock", but noticed >>> in your commit r191720: >>> Alexander Motin wrote: >>>> Add hint.apic.0.clock tunable. Setting it 0 disables using >>>> LAPIC timers as hard-/stat-/profclock sources falling back >>>> to using i8254 and rtc timers. >>>> ... >>>> This technique is not working for SMP yet, as only one CPU >>>> receives timer interrupts. But I think that problem could >>>> be fixed by forwarding interrupts to other CPUs with IPI. >>> Is anyone looking at this yet? >> I have implemented SMP support for i386 and amd64 in some of my later >> commits. > > And all those hacks helps verry little in my case, most gain I get when > laptop monitor is switched off. Even switching hard disk off improves battery > life very little. Monitor is surely one of major power consumers, but there are not so much things which you can do about it, as without power there will be no backlight. All you can do is tune backlight to minimum level required in every specific situation. What's about general effect, the main idea here is the same as in audio processing: result mostly depends on quality of the worst component. Your system may just have some other consumers which I don't have. For example, desktop CPU instead of mobile, desktop chipset instead of mobile, powerful external video instead of (or even in addition to) built-in, and so on. -- Alexander Motin