From owner-freebsd-hackers@FreeBSD.ORG Wed Apr 9 04:50:18 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 8236737B401 for ; Wed, 9 Apr 2003 04:50:18 -0700 (PDT) Received: from srv1.cosmo-project.de (srv1.cosmo-project.de [213.83.6.106]) by mx1.FreeBSD.org (Postfix) with ESMTP id 28C5A43F75 for ; Wed, 9 Apr 2003 04:50:17 -0700 (PDT) (envelope-from ticso@cicely9.cicely.de) Received: from cicely5.cicely.de (cicely5.cicely.de [IPv6:3ffe:400:8d0:301:200:92ff:fe9b:20e7]) by srv1.cosmo-project.de (8.12.9/8.12.9) with ESMTP id h39Bo7cx068431 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=OK) for ; Wed, 9 Apr 2003 13:50:13 +0200 (CEST) (envelope-from ticso@cicely9.cicely.de) Received: from cicely9.cicely.de (cicely9.cicely.de [IPv6:3ffe:400:8d0:301:210:5aff:fe30:1c1a]) by cicely5.cicely.de (8.12.9/8.12.9) with ESMTP id h39Bo5AL057388 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 9 Apr 2003 13:50:07 +0200 (CEST) (envelope-from ticso@cicely9.cicely.de) Received: from cicely9.cicely.de (localhost [127.0.0.1]) by cicely9.cicely.de (8.12.9/8.12.8) with ESMTP id h39Bo4i3095274 for ; Wed, 9 Apr 2003 13:50:05 +0200 (CEST) (envelope-from ticso@cicely9.cicely.de) Received: (from ticso@localhost) by cicely9.cicely.de (8.12.9/8.12.9/Submit) id h39Bo31l095271 for hackers@freebsd.org; Wed, 9 Apr 2003 13:50:03 +0200 (CEST) (envelope-from ticso) Date: Wed, 9 Apr 2003 13:49:58 +0200 From: Bernd Walter To: hackers@freebsd.org Message-ID: <20030409114957.GN83126@cicely9.cicely.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Operating-System: FreeBSD cicely9.cicely.de 5.0-CURRENT alpha User-Agent: Mutt/1.5.3i Subject: realtime problem X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: ticso@cicely.de List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 09 Apr 2003 11:50:18 -0000 I need a realtime behavour in the (-current) kernel with 1ms resolution and a presision of 500us. I thought about these two ways: - use timeout(9), but it seems that on i386 we only have a resolution of 10ms. And I don't know of what presision quality I can expect. Can the resolution changed to 1ms as we have on alpha? - attach to the clock service routine. I asume the presision will be good enough. But how can I find out the resolution on a given hardware? What is the best way to solve the problem? -- B.Walter BWCT http://www.bwct.de ticso@bwct.de info@bwct.de