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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@polymtl.ca,
	josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de,
	peterz@infradead.org, rostedt@goodmis.org,
	Valdis.Kletnieks@vt.edu, dhowells@redhat.com,
	edumazet@google.com, darren@dvhart.com, fweisbec@gmail.com,
	sbw@mit.edu, "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: [PATCH tip/core/rcu 7/7] rcu: Tone down debugging during boot-up and shutdown.
Date: Mon, 18 Mar 2013 14:16:56 -0700	[thread overview]
Message-ID: <1363641416-18642-7-git-send-email-paulmck@linux.vnet.ibm.com> (raw)
In-Reply-To: <1363641416-18642-1-git-send-email-paulmck@linux.vnet.ibm.com>

From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>

In some situations, randomly delaying RCU grace-period initialization
can cause more trouble than help.  This commit therefore restricts this
type of RCU self-torture to runtime, giving it a rest during boot and
shutdown.

Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
 kernel/rcutree.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 71df6f9..0e52250 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -1319,7 +1319,8 @@ static int rcu_gp_init(struct rcu_state *rsp)
 					    rnp->grphi, rnp->qsmask);
 		raw_spin_unlock_irq(&rnp->lock);
 #ifdef CONFIG_PROVE_RCU_DELAY
-		if ((random32() % (rcu_num_nodes * 8)) == 0)
+		if ((random32() % (rcu_num_nodes * 8)) == 0 &&
+		    system_state == SYSTEM_RUNNING)
 			schedule_timeout_uninterruptible(2);
 #endif /* #ifdef CONFIG_PROVE_RCU_DELAY */
 		cond_resched();
-- 
1.8.1.5


      parent reply	other threads:[~2013-03-18 21:17 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-03-18 21:16 [PATCH tip/core/rcu 0/7] Fixes for 3.9 Paul E. McKenney
2013-03-18 21:16 ` [PATCH tip/core/rcu 1/7] rcu: Fix spacing problem Paul E. McKenney
2013-03-18 21:16   ` [PATCH tip/core/rcu 2/7] rcu: Avoid invoking RCU core on offline CPUs Paul E. McKenney
2013-03-18 21:16   ` [PATCH tip/core/rcu 3/7] rcu: Remove comment referring to __stop_machine() Paul E. McKenney
2013-03-18 21:16   ` [PATCH tip/core/rcu 4/7] rcu: Delete unused rcu_node "wakemask" field Paul E. McKenney
2013-03-18 21:16   ` [PATCH tip/core/rcu 5/7] rcu: Fix hlist_bl_set_first_rcu() annotation Paul E. McKenney
2013-03-18 21:16   ` [PATCH tip/core/rcu 6/7] rcu: Add softirq-stall indications to stall-warning messages Paul E. McKenney
2013-03-18 21:16   ` Paul E. McKenney [this message]

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