From owner-freebsd-acpi@FreeBSD.ORG Mon Nov 10 20:36:46 2008 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 3418B1065962 for ; Mon, 10 Nov 2008 20:36:46 +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 AF4A38FC16 for ; Mon, 10 Nov 2008 20:36:45 +0000 (UTC) (envelope-from mav@FreeBSD.org) X-Spam-Flag: SKIP X-Spam-Yversion: Spamooborona-2.1.0 Received: from [77.52.118.234] (account mav@alkar.net HELO mavbook.mavhome.dp.ua) by cmail.optima.ua (CommuniGate Pro SMTP 5.2.9) with ESMTPSA id 227514485; Mon, 10 Nov 2008 22:36:43 +0200 Message-ID: <49189B47.7090509@FreeBSD.org> Date: Mon, 10 Nov 2008 22:36:23 +0200 From: Alexander Motin User-Agent: Thunderbird 2.0.0.17 (X11/20081029) MIME-Version: 1.0 To: Nate Lawson References: <491404BF.1090807@FreeBSD.org> <49186111.9020103@root.org> In-Reply-To: <49186111.9020103@root.org> Content-Type: text/plain; charset=KOI8-R; format=flowed Content-Transfer-Encoding: 7bit Cc: FreeBSD acpi Subject: Re: RFC: powerd algorithms enhancements 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: Mon, 10 Nov 2008 20:36:46 -0000 Nate Lawson wrote: > Alexander Motin wrote: >> 2. To make powerd's operation independent from number and size of >> frequency levels I have added internal frequency counter which >> translated into real frequencies only on a last stage and only as good >> as gone. Some systems may have only several power levels, while mine has >> 17 of them, so adaptation time in completely different. It would be good >> if algorithm was not depending on it. > > I don't understand the advantage of this. Universality and predictiveness. Systems with 2 and with 32 levels will drop/rise frequency with same absolute rate. If we are trying to speak about some comparing, algorithm should be hardware independent. > There's a patch Cyrille Szymanski has sent me to review that implements > the FLAT and PAST algorithms in powerd. I think we should not add new > modes that are heuristics (including this one) until we have a chance to > compare it to algorithms that have been the result of real research. So show it to us. This area is heuristic by default as there is several opposite criteriums, so any algorithm will be heuristic. -- Alexander Motin