From owner-freebsd-hackers@FreeBSD.ORG Tue Aug 5 03:22:43 2003 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id D031C37B401 for ; Tue, 5 Aug 2003 03:22:43 -0700 (PDT) Received: from netlx014.civ.utwente.nl (netlx014.civ.utwente.nl [130.89.1.88]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7EE7D43FAF for ; Tue, 5 Aug 2003 03:22:42 -0700 (PDT) (envelope-from r.s.a.vandomburg@student.utwente.nl) Received: from student.utwente.nl (gog.student.utwente.nl [130.89.165.107]) by netlx014.civ.utwente.nl (8.11.4/HKD) with ESMTP id h75AMQY00298 for ; Tue, 5 Aug 2003 12:22:27 +0200 Message-ID: <3F2F8562.9090609@student.utwente.nl> Date: Tue, 05 Aug 2003 12:22:26 +0200 From: Roderick van Domburg Organization: University of Twente User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.4) Gecko/20030803 X-Accept-Language: en-us, en MIME-Version: 1.0 To: freebsd-hackers@freebsd.org X-Enigmail-Version: 0.76.4.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-UTwente-MailScanner: Found to be clean Subject: Re: Tuning HZ for semi-realtime applications X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 05 Aug 2003 10:22:44 -0000 There's this Linux kernel patch that allows for timeslice tuning. It's got the following rules of the thumb: * The optimal setting is your CPU's speed in MHz's / 2 * ...but there is no point in going above 1000 Hz * ...and be sure to use multiples of 100 Hz I am everything but an expert at scheduling, but somehow this makes sense: i.e. one jiffy for the scheduler and one jiffy for the process. Does all of this make any sense or is it just a load of hooey? Regards, Roderick