From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262582AbVFVW4E (ORCPT ); Wed, 22 Jun 2005 18:56:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261175AbVFVWxR (ORCPT ); Wed, 22 Jun 2005 18:53:17 -0400 Received: from opersys.com ([64.40.108.71]:7953 "EHLO www.opersys.com") by vger.kernel.org with ESMTP id S262467AbVFVWvg (ORCPT ); Wed, 22 Jun 2005 18:51:36 -0400 Message-ID: <42B9EE0B.80802@opersys.com> Date: Wed, 22 Jun 2005 19:02:35 -0400 From: Karim Yaghmour Reply-To: karim@opersys.com Organization: Opersys inc. User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.2) Gecko/20040805 Netscape/7.2 X-Accept-Language: en-us, en, fr, fr-be, fr-ca, fr-fr MIME-Version: 1.0 To: Ingo Molnar CC: "Paul E. McKenney" , Kristian Benoit , linux-kernel@vger.kernel.org, bhuey@lnxw.com, andrea@suse.de, tglx@linutronix.de, pmarques@grupopie.com, bruce@andrew.cmu.edu, nickpiggin@yahoo.com.au, ak@muc.de, sdietrich@mvista.com, dwalker@mvista.com, hch@infradead.org, akpm@osdl.org, Philippe Gerum Subject: Re: PREEMPT_RT vs I-PIPE: the numbers, part 2 References: <42B77B8C.6050109@opersys.com> <20050622011931.GF1324@us.ibm.com> <42B9845B.8030404@opersys.com> <20050622162718.GD1296@us.ibm.com> <1119460803.5825.13.camel@localhost> <20050622185019.GG1296@us.ibm.com> <20050622190422.GA6572@elte.hu> <42B9C777.8040202@opersys.com> <20050622202242.GA17301@elte.hu> <42B9D208.4080305@opersys.com> <20050622224123.GA7658@elte.hu> In-Reply-To: <20050622224123.GA7658@elte.hu> 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 Ingo Molnar wrote: > otherwise par_test_irq_handler will run with interrupts enabled, opening > the window for other interrupts to be injected and increasing the > worst-case latency! Take a look at drivers/char/lpptest.c how to do this > properly. Also, double-check that there is no IRQ 7 thread running on > the PREEMPT_RT kernel, to make sure you are measuring irq latencies. We'll check on this also. Thanks for pointing it out. Karim -- Author, Speaker, Developer, Consultant Pushing Embedded and Real-Time Linux Systems Beyond the Limits http://www.opersys.com || karim@opersys.com || 1-866-677-4546