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From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com,
	akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
	josh@joshtriplett.org, 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: [PATCH tip/core/rcu] Introduce check for callback list/count mismatch
Date: Thu, 5 Jul 2012 15:33:19 -0700	[thread overview]
Message-ID: <20120705223319.GA27331@linux.vnet.ibm.com> (raw)

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 <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

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);
 


             reply	other threads:[~2012-07-05 22:33 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-05 22:33 Paul E. McKenney [this message]
2012-07-05 22:55 ` [PATCH tip/core/rcu] Introduce check for callback list/count mismatch Josh Triplett

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