From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754808Ab2HaR41 (ORCPT ); Fri, 31 Aug 2012 13:56:27 -0400 Received: from relay4-d.mail.gandi.net ([217.70.183.196]:41775 "EHLO relay4-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754378Ab2HaR40 (ORCPT ); Fri, 31 Aug 2012 13:56:26 -0400 X-Originating-IP: 217.70.178.144 X-Originating-IP: 173.246.103.110 Date: Fri, 31 Aug 2012 10:56:17 -0700 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, sbw@mit.edu, patches@linaro.org, "Paul E. McKenney" Subject: Re: [PATCH tip/core/rcu 03/15] rcu: Properly initialize ->boost_tasks on CPU offline Message-ID: <20120831175617.GA4259@jtriplet-mobl1> References: <20120830185607.GA32148@linux.vnet.ibm.com> <1346352988-32444-1-git-send-email-paulmck@linux.vnet.ibm.com> <1346352988-32444-3-git-send-email-paulmck@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1346352988-32444-3-git-send-email-paulmck@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, Aug 30, 2012 at 11:56:16AM -0700, Paul E. McKenney wrote: > From: "Paul E. McKenney" > > When rcu_preempt_offline_tasks() clears tasks from a leaf rcu_node > structure, it does not NULL out the structure's ->boost_tasks field. > This commit therefore fixes this issue. > > Signed-off-by: Paul E. McKenney > Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett > --- > kernel/rcutree_plugin.h | 7 ++++--- > 1 files changed, 4 insertions(+), 3 deletions(-) > > diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h > index 7f3244c..b1b4851 100644 > --- a/kernel/rcutree_plugin.h > +++ b/kernel/rcutree_plugin.h > @@ -584,8 +584,11 @@ static int rcu_preempt_offline_tasks(struct rcu_state *rsp, > raw_spin_unlock(&rnp_root->lock); /* irqs still disabled */ > } > > + rnp->gp_tasks = NULL; > + rnp->exp_tasks = NULL; > #ifdef CONFIG_RCU_BOOST > - /* In case root is being boosted and leaf is not. */ > + rnp->boost_tasks = NULL; > + /* In case root is being boosted and leaf was not. */ > raw_spin_lock(&rnp_root->lock); /* irqs already disabled */ > if (rnp_root->boost_tasks != NULL && > rnp_root->boost_tasks != rnp_root->gp_tasks) > @@ -593,8 +596,6 @@ static int rcu_preempt_offline_tasks(struct rcu_state *rsp, > raw_spin_unlock(&rnp_root->lock); /* irqs still disabled */ > #endif /* #ifdef CONFIG_RCU_BOOST */ > > - rnp->gp_tasks = NULL; > - rnp->exp_tasks = NULL; > return retval; > } > > -- > 1.7.8 >