From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfgang Grandegger Subject: Re: High latencies on MPC5200 with patch-2.6.24-rc5-rt1 Date: Thu, 10 Jan 2008 22:49:58 +0100 Message-ID: <47869306.8000308@grandegger.com> References: <47834CB7.1030102@grandegger.com> <20080108154947.GB3177@pengutronix.de> <20080109090345.GG3177@pengutronix.de> <20080109225107.GV3177@pengutronix.de> <20080110000124.GW3177@pengutronix.de> <47861ACE.9060301@grandegger.com> <20080110143527.GI3177@pengutronix.de> <20080110162351.GN3177@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: Thomas Gleixner , linux-rt-users@vger.kernel.org, John Stultz To: Robert Schwebel Return-path: Received: from mail-out.m-online.net ([212.18.0.9]:39568 "EHLO mail-out.m-online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752918AbYAJVuD (ORCPT ); Thu, 10 Jan 2008 16:50:03 -0500 In-Reply-To: <20080110162351.GN3177@pengutronix.de> Sender: linux-rt-users-owner@vger.kernel.org List-ID: Robert Schwebel wrote: > On Thu, Jan 10, 2008 at 03:35:27PM +0100, Robert Schwebel wrote: >>> Could you run your cyclictest much longer? >> I'll re-test with your parameters. > > Done, here are the results (data and histogram): > > http://www.pengutronix.de/software/realtime-preempt/20080110-1-cyclictest/20080110-1-phyCORE-MPC5200B-tiny-data.png > http://www.pengutronix.de/software/realtime-preempt/20080110-1-cyclictest/20080110-1-phyCORE-MPC5200B-tiny-histo.png > > Especially the data plot is interesting: it shows that most of the shots > are below 80 us, but there are regular peaks. If you look carefully, you > also see that the peaks are "growing", which usually means that there is > some interference. A latency peak every 16.6 second, hm, interesting. > Time to activate latency hunting... Unfortunately, the latency tracer of the -rt kernel is not available for PowerPC. Wolfgang.