From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754831Ab2AXTX2 (ORCPT ); Tue, 24 Jan 2012 14:23:28 -0500 Received: from e7.ny.us.ibm.com ([32.97.182.137]:47633 "EHLO e7.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753729Ab2AXTX0 (ORCPT ); Tue, 24 Jan 2012 14:23:26 -0500 Date: Tue, 24 Jan 2012 11:09:05 -0800 From: "Paul E. McKenney" To: Frederic Weisbecker Cc: Eric Dumazet , Ingo Molnar , Linus Torvalds , linux-kernel@vger.kernel.org, Thomas Gleixner , Peter Zijlstra , Andrew Morton Subject: Re: [GIT PULL] RCU changes for v3.3 Message-ID: <20120124190904.GA2381@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20120105135432.GA31450@elte.hu> <1327422312.7231.22.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> <20120124165312.GG2531@linux.vnet.ibm.com> <20120124170414.GA20878@somewhere> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20120124170414.GA20878@somewhere> User-Agent: Mutt/1.5.21 (2010-09-15) X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12012419-5806-0000-0000-000011B2D761 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 24, 2012 at 06:04:17PM +0100, Frederic Weisbecker wrote: > On Tue, Jan 24, 2012 at 08:53:13AM -0800, Paul E. McKenney wrote: > > On Tue, Jan 24, 2012 at 05:25:12PM +0100, Eric Dumazet wrote: > > > Le jeudi 05 janvier 2012 à 14:54 +0100, Ingo Molnar a écrit : > > > > Linus, > > > > > > > > Please pull the latest core-rcu-for-linus git tree from: > > > > > > > > git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git core-rcu-for-linus > > > > > > > > Thanks, > > > > > > Hi guys > > > > > > New lockdep warning here : > > > > Hmmm... Looks like tracing from within the inner idle loop. > > > > Because RCU ignores CPUs in the inner idle loop (after the call to > > rcu_idle_enter()), RCU read-side critical sections are not legal there. > > > > One approach would be to delay the call to rcu_idle_enter() until after > > the tracing is done, and to ensure that the call to rcu_idle_exit() happens > > before any tracing. I am not seeing perf_trace_power(), so need to > > update and look again. Or are you looking at -next rather than mainline? > > perf_trace_power() is automatically generated by include/trace/ftrace.h > This is a tracepoint handler so we don't need to worry about it. The problem > is the call to the tracepoint itself. Agreed. I was just naively expecting "git grep perf_trace_power" to show me the call points. :-( Thanx, Paul