From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757867Ab2FOUlA (ORCPT ); Fri, 15 Jun 2012 16:41:00 -0400 Received: from relay3-d.mail.gandi.net ([217.70.183.195]:53194 "EHLO relay3-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757602Ab2FOUk7 (ORCPT ); Fri, 15 Jun 2012 16:40:59 -0400 X-Originating-IP: 217.70.178.130 X-Originating-IP: 50.43.46.74 Date: Fri, 15 Jun 2012 13:40:48 -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, patches@linaro.org, "Paul E. McKenney" Subject: Re: [PATCH tip/core/rcu 01/14] rcu: Fix detection of abruptly-ending stall Message-ID: <20120615204048.GF31184@leaf> References: <20120615201256.GA26120@linux.vnet.ibm.com> <1339791195-26389-1-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: <1339791195-26389-1-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 Fri, Jun 15, 2012 at 01:13:02PM -0700, Paul E. McKenney wrote: > From: "Paul E. McKenney" > > The code that attempts to identify stalls that end just as we detect > them is broken by both flavors of initialization failure. This commit > therefore properly initializes and computes the count of the number > of reasons why the RCU grace period is stalled. > > Signed-off-by: Paul E. McKenney > Signed-off-by: Paul E. McKenney This approach definitely seems more robust against future code changes. Reviewed-by: Josh Triplett > --- > kernel/rcutree.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/rcutree.c b/kernel/rcutree.c > index 0da7b88..0f04480 100644 > --- a/kernel/rcutree.c > +++ b/kernel/rcutree.c > @@ -732,7 +732,7 @@ static void print_other_cpu_stall(struct rcu_state *rsp) > int cpu; > long delta; > unsigned long flags; > - int ndetected; > + int ndetected = 0; > struct rcu_node *rnp = rcu_get_root(rsp); > > /* Only let one CPU complain about others per time interval. */ > @@ -773,7 +773,7 @@ static void print_other_cpu_stall(struct rcu_state *rsp) > */ > rnp = rcu_get_root(rsp); > raw_spin_lock_irqsave(&rnp->lock, flags); > - ndetected = rcu_print_task_stall(rnp); > + ndetected += rcu_print_task_stall(rnp); > raw_spin_unlock_irqrestore(&rnp->lock, flags); > > print_cpu_stall_info_end(); > -- > 1.7.8 >