Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756100AbYGFAj6 (ORCPT ); Sat, 5 Jul 2008 20:39:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753174AbYGFAju (ORCPT ); Sat, 5 Jul 2008 20:39:50 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.124]:46534 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753057AbYGFAjt (ORCPT ); Sat, 5 Jul 2008 20:39:49 -0400 Date: Sat, 5 Jul 2008 20:39:46 -0400 (EDT) From: Steven Rostedt X-X-Sender: rostedt@gandalf.stny.rr.com To: Wolfgang Grandegger 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? In-Reply-To: <486B37BF.6030107@grandegger.com> Message-ID: 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> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 923 Lines: 26 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. -- Steve -- 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/