Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261307AbUJ3UQJ (ORCPT ); Sat, 30 Oct 2004 16:16:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261308AbUJ3UQI (ORCPT ); Sat, 30 Oct 2004 16:16:08 -0400 Received: from pop.gmx.net ([213.165.64.20]:51176 "HELO mail.gmx.net") by vger.kernel.org with SMTP id S261307AbUJ3UPw (ORCPT ); Sat, 30 Oct 2004 16:15:52 -0400 X-Authenticated: #4399952 Date: Sat, 30 Oct 2004 22:15:48 +0200 From: Florian Schmidt To: Lee Revell Cc: Ingo Molnar , Paul Davis , Thomas Gleixner , LKML , mark_h_johnson@raytheon.com, Bill Huey , Adam Heath , Michal Schmidt , Fernando Pablo Lopez-Lezcano , Karsten Wiese , jackit-devel , Rui Nuno Capela Subject: Re: [Fwd: Re: [patch] Real-Time Preemption, -RT-2.6.9-mm1-V0.4] Message-ID: <20041030221548.5e82fad5@mango.fruits.de> In-Reply-To: <1099165925.1972.22.camel@krustophenia.net> References: <20041029172243.GA19630@elte.hu> <20041029203619.37b54cba@mango.fruits.de> <20041029204220.GA6727@elte.hu> <20041029233117.6d29c383@mango.fruits.de> <20041029212545.GA13199@elte.hu> <1099086166.1468.4.camel@krustophenia.net> <20041029214602.GA15605@elte.hu> <1099091566.1461.8.camel@krustophenia.net> <20041030115808.GA29692@elte.hu> <1099158570.1972.5.camel@krustophenia.net> <20041030191725.GA29747@elte.hu> <20041030214738.1918ea1d@mango.fruits.de> <1099165925.1972.22.camel@krustophenia.net> X-Mailer: Sylpheed-Claws 0.9.12b (GTK+ 1.2.10; i386-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1375 Lines: 37 On Sat, 30 Oct 2004 15:52:04 -0400 Lee Revell wrote: > Yup there is definitely something not right: [snip] > You should modify the program to print something when it sees a big > miss. This would make it easier to figure out what kind of system > activity triggers the problem. right, i just wanted to avoid doing that from the process that polls itself, because a std::cout << "ugh!" << std::endl; might already be enough to skew the following irq's, right? anyways, this new version [just upped] prints a line when a missed irq was detected. Also this version understands a third parameter which acts as an upper threshold. A line is printed when the difference of the cycle count of two consecutive wakeups is greater than the threshold. run it once w/o threshold on an idle system to see what a useful thresh would be. i use it like this for example: ./rt_wakeup 1024 50000 1200000 What's the best way to find out the cycles/s of the cpu? This way the input/output could become a little nicer [because then i can calculate programatically how long a "perfect" period should be in cycles]. flo - 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/