From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261670AbVFUCCo (ORCPT ); Mon, 20 Jun 2005 22:02:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261859AbVFUB71 (ORCPT ); Mon, 20 Jun 2005 21:59:27 -0400 Received: from e4.ny.us.ibm.com ([32.97.182.144]:7050 "EHLO e4.ny.us.ibm.com") by vger.kernel.org with ESMTP id S261853AbVFUBz0 (ORCPT ); Mon, 20 Jun 2005 21:55:26 -0400 Date: Mon, 20 Jun 2005 18:55:42 -0700 From: "Paul E. McKenney" To: Kristian Benoit Cc: linux-kernel@vger.kernel.org, bhuey@lnxw.com, andrea@suse.de, tglx@linutronix.de, karim@opersys.com, mingo@elte.hu, 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, rpm@xenomai.org Subject: Re: PREEMPT_RT vs I-PIPE: the numbers, part 2 Message-ID: <20050621015542.GB1298@us.ibm.com> Reply-To: paulmck@us.ibm.com References: <1119287612.6863.1.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1119287612.6863.1.camel@localhost> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 20, 2005 at 01:13:32PM -0400, Kristian Benoit wrote: > We've finally been able to complete a second round of our tests. > Unfortunately, this has taken much longer than we ever anticipated. > Without going into too much detail, suffice it to say that we ran into > problems with each of our intended test configurations. Fortunately, > the results are that much more interesting and, we hope, more > accurately illustrate the performance of the approaches being > compared. Again, good stuff! It looks to me that I-PIPE is an example of a "nested OS", with Linux nested within the I-PIPE functionality. One could take the RTAI-Fusion approach, but this measurement is of I-PIPE rather than RTAI-Fusion, right? (And use of RTAI-Fusion might or might not change these results significantly, just trying to make sure I understand what these specific tests apply to.) Also, if I understand correctly, the interrupt latency measured is to the Linux kernel running within I-PIPE, rather than to I-PIPE itself. Is this the case, or am I confused? Thanx, Paul