From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754895Ab2BCCoK (ORCPT ); Thu, 2 Feb 2012 21:44:10 -0500 Received: from relay4-d.mail.gandi.net ([217.70.183.196]:51781 "EHLO relay4-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751208Ab2BCCoJ (ORCPT ); Thu, 2 Feb 2012 21:44:09 -0500 X-Originating-IP: 217.70.178.134 X-Originating-IP: 50.43.15.19 Date: Thu, 2 Feb 2012 18:43:46 -0800 From: Josh Triplett To: "Paul E. McKenney" Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, eric.dumazet@gmail.com, darren@dvhart.com, fweisbec@gmail.com, patches@linaro.org Subject: Re: [PATCH RFC 0/3] Fix cpuidle_idle_call() RCU usage Message-ID: <20120203024346.GE13456@leaf> References: <20120203011208.GA2004@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120203011208.GA2004@linux.vnet.ibm.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 02, 2012 at 05:12:08PM -0800, Paul E. McKenney wrote: > This patch series is a second attempt to fix the idle-loop uses of RCU, > see https://lkml.org/lkml/2012/2/1/741 for v1. Where the first series > attempted to drive rcu_idle_enter() and rcu_idle_exit() further down > into the Linux kernels multitude of idle loops, this patch instead > marks specific idle-loop operations containing RCU read-side critical > sections, as suggested by Nicolas Pitre and Steven Rostedt. The possibility > of code shared between idle and non-idle also requires the ability to nest > rcu_idle_enter() calls. The individual patches are as follows: > > 1. Allow nesting of rcu_idle_enter() and rcu_idle_exit(). > 2. Add an RCU_NONIDLE() macro to enclose idle-loop code that > contains RCU read-side critical sections. > 3. Use RCU_NONIDLE() to protect cpuidle_idle_call()'s tracepoints. > > This patchset has the distinct advantage of avoiding touching any > architecture-specific code. ;-) > > Thanx, Paul > > ------------------------------------------------------------------------ > > b/drivers/cpuidle/cpuidle.c | 12 ++++++++---- > b/include/linux/rcupdate.h | 27 +++++++++++++++++++++++++++ > b/kernel/rcu.h | 18 +++++++++++++++++- > b/kernel/rcutiny.c | 16 ++++++++++++---- > b/kernel/rcutree.c | 19 +++++++++++++------ > kernel/rcutiny.c | 2 ++ > kernel/rcutree.c | 2 ++ > 7 files changed, 81 insertions(+), 15 deletions(-) Looks good to me. Much cleaner. Reviewed-by: Josh Triplett