From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933274Ab2GEWzl (ORCPT ); Thu, 5 Jul 2012 18:55:41 -0400 Received: from relay3-d.mail.gandi.net ([217.70.183.195]:56710 "EHLO relay3-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932163Ab2GEWzk (ORCPT ); Thu, 5 Jul 2012 18:55:40 -0400 X-Originating-IP: 217.70.178.130 X-Originating-IP: 50.43.46.74 Date: Thu, 5 Jul 2012 15:55:25 -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@efficios.com, 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 Subject: Re: [PATCH tip/core/rcu] Introduce check for callback list/count mismatch Message-ID: <20120705225525.GA26150@leaf> References: <20120705223319.GA27331@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120705223319.GA27331@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, Jul 05, 2012 at 03:33:19PM -0700, Paul E. McKenney wrote: > The recent bug that introduced the RCU callback list/count mismatch > showed the need for a diagnostic to check for this, which this patch > adds. > > Signed-off-by: Paul E. McKenney > Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett > diff --git a/kernel/rcutree.c b/kernel/rcutree.c > index 95c7b61..4154c95 100644 > --- a/kernel/rcutree.c > +++ b/kernel/rcutree.c > @@ -1612,6 +1612,7 @@ static void rcu_do_batch(struct rcu_state *rsp, struct rcu_data *rdp) > rdp->n_force_qs_snap = rsp->n_force_qs; > } else if (rdp->qlen < rdp->qlen_last_fqs_check - qhimark) > rdp->qlen_last_fqs_check = rdp->qlen; > + WARN_ON_ONCE((rdp->nxtlist == NULL) != (rdp->qlen == 0)); > > local_irq_restore(flags); > >