Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 10 Feb 2003 10:33:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 10 Feb 2003 10:33:22 -0500 Received: from wohnheim.fh-wedel.de ([195.37.86.122]:8658 "EHLO wohnheim.fh-wedel.de") by vger.kernel.org with ESMTP id ; Mon, 10 Feb 2003 10:33:21 -0500 Date: Mon, 10 Feb 2003 16:43:04 +0100 From: =?iso-8859-1?Q?J=F6rn?= Engel To: Dan Parks Cc: SA , linux-kernel@vger.kernel.org Subject: Re: interrupt latency ? Message-ID: <20030210154304.GA1973@wohnheim.fh-wedel.de> References: <200302071850.52781.no_spam@ntlworld.com> <20030210135822.GA14827@wohnheim.fh-wedel.de> <1044889126.1438.460.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1044889126.1438.460.camel@localhost> User-Agent: Mutt/1.3.28i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1009 Lines: 27 On Mon, 10 February 2003 09:58:46 -0500, Dan Parks wrote: > > Do you happen to have a program (or kernel module...) that times these > latencies? I've been trying to generate statistics about these kinds of > latencies, and have yet to be happy with any of my tests. That should be impossible to do. :) Write a simple handler for parport or so, that is called when line #1 toggles from low to high and responds by pulling line #2 from low to high. Now hook up a signal generator and an oszilloscope and measure the time from signal generation to the physical reaction. This way you get all the latency, not just the small amount you can measure inside the kernel. J?rn -- Everything should be made as simple as possible, but not simpler. -- Albert Einstein - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/