From owner-freebsd-acpi@FreeBSD.ORG Fri Oct 27 08:46:38 2006 Return-Path: X-Original-To: acpi@freebsd.org Delivered-To: freebsd-acpi@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 808EF16A5C1 for ; Fri, 27 Oct 2006 08:46:38 +0000 (UTC) (envelope-from smithi@nimnet.asn.au) Received: from gaia.nimnet.asn.au (nimbin.lnk.telstra.net [139.130.45.143]) by mx1.FreeBSD.org (Postfix) with ESMTP id CC32943D46 for ; Fri, 27 Oct 2006 08:46:35 +0000 (GMT) (envelope-from smithi@nimnet.asn.au) Received: from localhost (smithi@localhost) by gaia.nimnet.asn.au (8.8.8/8.8.8R1.4) with SMTP id SAA03550; Fri, 27 Oct 2006 18:45:23 +1000 (EST) (envelope-from smithi@nimnet.asn.au) Date: Fri, 27 Oct 2006 18:45:22 +1000 (EST) From: Ian Smith To: Kevin Oberman In-Reply-To: <20061026204328.C764F4504D@ptavv.es.net> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: acpi@freebsd.org Subject: Re: powerd: add support for limiting cpu frequency on adaptive mode 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, 27 Oct 2006 08:46:38 -0000 On Thu, 26 Oct 2006, Kevin Oberman wrote: > > Can someone look on the pr > > (http://www.freebsd.org/cgi/query-pr.cgi?pr=bin/104689) I sent. Maybe > > the patch is dirty but I think that idea is nice and with it battery > > lives really longer. > > YES! When I am on battery for an extended time, I am very happy to have > the system max out at a MUCH lower speed if I can keep basic capabilities > for simple stuff like editing and such. Slight slow-downs are not an > issue. The problem I see with this patch as it stands is that it affects both battery and AC power adaptive modes (ie, powerd default operating mode) Stepan says in the PR: "Apply the patch and run powerd: powerd -a maximum -b adaptive -m 558 Where 558 is maximum frequency on adaptive mode" I want to run adaptive mode on 'AC' both because it uses half the power when idle and greatly reduces the laptop's temperature (Thinkpad T23). 'AC' in quotes, this being a 100% solar power home; every watt counts. Were the -m switch function ANDed with (acline_status = SRC_BATTERY) or perhaps, allowing for SRC_UNKNOWN, (acline_status != SRC_AC) then you could still use adaptive mode at full speed on 'AC' when required and take advantage of setting a maximum speed while running on battery? > That said, power consumption is NOT intuitive. If I am playing an MP3 > (very constant CPU load) at a speed where the CPU is at about 80%, the > system uses more power than when the CPU is at 30%. In either case, the > MP3 playback is fine. (This was on my T30 with a 1.8G P4M CPU, so it's > not the best for power use.) The T23 is only a two-speed P3M (1133/733) so I've yet to see the full potential of powerd, nor have I played with its idle/busy shift points or examined hysteresis between load shift points at various freqs, but it's already a Very Good Thing here .. > I know that Windows wants to reduce maximum CPU speed when running on > battery, so I do believe this is a good thing. If limited to while running on battery only, I'd heartily agree. Meanwhile of course you can run powerd -b min though that might be overkill if you have lots of freqs available .. Cheers, Ian