Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756226AbYGFJeO (ORCPT ); Sun, 6 Jul 2008 05:34:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752205AbYGFJd7 (ORCPT ); Sun, 6 Jul 2008 05:33:59 -0400 Received: from mail-out.m-online.net ([212.18.0.9]:59099 "EHLO mail-out.m-online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751960AbYGFJd5 (ORCPT ); Sun, 6 Jul 2008 05:33:57 -0400 X-Auth-Info: Oacw2Xe2vPY1jC0W0dpS/ZznlURtEMktAvDU3xgniuc= X-Auth-Info: Oacw2Xe2vPY1jC0W0dpS/ZznlURtEMktAvDU3xgniuc= X-Auth-Info: Oacw2Xe2vPY1jC0W0dpS/ZznlURtEMktAvDU3xgniuc= X-Auth-Info: Oacw2Xe2vPY1jC0W0dpS/ZznlURtEMktAvDU3xgniuc= X-Auth-Info: Oacw2Xe2vPY1jC0W0dpS/ZznlURtEMktAvDU3xgniuc= X-Auth-Info: Oacw2Xe2vPY1jC0W0dpS/ZznlURtEMktAvDU3xgniuc= X-Auth-Info: Oacw2Xe2vPY1jC0W0dpS/ZznlURtEMktAvDU3xgniuc= Message-ID: <487091AE.8060702@grandegger.com> Date: Sun, 06 Jul 2008 11:34:38 +0200 From: Wolfgang Grandegger User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Steven Rostedt CC: "Paul E. McKenney" , Luotao Fu , LKML , RT , Ingo Molnar , Thomas Gleixner Subject: Re: 2.6.24-rc8-rt1: Strange latencies on mpc5200 powerpc - RCU issue? References: <47976D06.1010900@grandegger.com> <479DF0A1.3000906@pengutronix.de> <479DF711.5090406@grandegger.com> <479F186A.4020004@pengutronix.de> <479F2C3C.1020203@grandegger.com> <20080130010716.GB16069@linux.vnet.ibm.com> <47A032E9.4080105@grandegger.com> <20080130102255.GA24890@linux.vnet.ibm.com> <47A0552D.20605@grandegger.com> <20080130105715.GE24890@linux.vnet.ibm.com> <20080130111559.GC20089@pengutronix.de> <486A3EBB.6030905@grandegger.com> <486B37BF.6030107@grandegger.com> In-Reply-To: X-Enigmail-Version: 0.95.6 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1180 Lines: 28 Steven Rostedt wrote: > On Wed, 2 Jul 2008, Wolfgang Grandegger wrote: > >> Steven Rostedt wrote: >>> On Tue, 1 Jul 2008, Wolfgang Grandegger wrote: >>>> I continue this thread because it's still not understood why enabling >>>> CONFIG_RCU_TRACE is necessary to get reasonable latencies on the >>>> MPC5200. It might also explain, why I get much worse latencies with >>>> 2.6.25.8-rt7. >>> Have you tried turning on ftrace? >> Hm, is it available for PowerPC? I have not found yet how to enable it. > > Hmm, should be. But I need to test it on my PPC box first before I can > tell you for sure. If you don't see a way to enable it, perhaps I haven't > updated the config options for PPC yet. I added HAVE_FTRACE and HAVE_DYNAMIC_FTRACE to "config PPC" but more seems to be missing, e.g. arch/powerpc/kernel/ftrace.c. Nevertheless, how would I trigger high latency events with ftrace. I there a description somewhere? Wolfgang. -- 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/