From owner-freebsd-acpi@FreeBSD.ORG Sun Dec 4 03:05:59 2005 Return-Path: X-Original-To: freebsd-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 704B016A41F for ; Sun, 4 Dec 2005 03:05:59 +0000 (GMT) (envelope-from kjelderg@gmail.com) Received: from zproxy.gmail.com (zproxy.gmail.com [64.233.162.193]) by mx1.FreeBSD.org (Postfix) with ESMTP id EC57943D5C for ; Sun, 4 Dec 2005 03:05:58 +0000 (GMT) (envelope-from kjelderg@gmail.com) Received: by zproxy.gmail.com with SMTP id i11so800870nzh for ; Sat, 03 Dec 2005 19:05:58 -0800 (PST) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=j5WGgYzy0PQzGXgCmG8EWidFMyKloEmGn6S2G/TOgTa22jBnLWahAATWbDRmMwAUlMNj+qQSstFqGeid4lp6hUY/esembz/9qQgtS/3QAeCfJo4n8aD11rfil/ABFZm/0cDr/F/qtuBLJeHfFHRXlHzmDa1TXyzfcqjr8VvOU8g= Received: by 10.65.188.8 with SMTP id q8mr2156695qbp; Sat, 03 Dec 2005 19:05:58 -0800 (PST) Received: by 10.65.22.9 with HTTP; Sat, 3 Dec 2005 19:05:58 -0800 (PST) Message-ID: Date: Sun, 4 Dec 2005 12:05:58 +0900 From: Eric Kjeldergaard To: freebsd-acpi@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Subject: cpufreq and schedulers instead of powerd 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: Sun, 04 Dec 2005 03:05:59 -0000 Hello all. I hope this is the right place for such an item. I've been pondering processor dynamic clocking for a while and recently have been wondering if it is optimal to have the processor rate chosen by a daemon as it is now, or rather integrate the downclocking into the scheduler. My reasoning largely is based on the thought of overhead for switching processor speeds. With modernish processors (especially the Pentium-m) it seems that the time to change operating frequencies is very low which would lead me to think that something like a scheduler could take advantage of that and clock them down faster and more often. Also, schedulers (I've been looking mainly at ULE) have more knowledge about processor usage than just the current load which appears to be all that powerd looks at. Does anyone have any additional information on dynamic clock handling in OS schedulers or information on why freebsd chose powerd over an implementation in scheduler(s)? Eric Kjeldergaard -- If I write a signature, my emails will appear more personalised.