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From:   "Neeraj Upadhyay (AMD)" <neeraj.iitr10@gmail.com>
To:     rcu@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org, kernel-team@meta.com,
        rostedt@goodmis.org, paulmck@kernel.org, Neeraj.Upadhyay@amd.com,
        Zqiang <qiang.zhang1211@gmail.com>,
        Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Subject: [PATCH rcu 4/4] rcutorture: Add fqs_holdoff check before fqs_task is created
Date:   Tue, 12 Dec 2023 23:04:14 +0530
Message-Id: <20231212173414.11602-4-neeraj.iitr10@gmail.com>
In-Reply-To: <20231212173334.GA11572@neeraj.linux>
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From: Zqiang <qiang.zhang1211@gmail.com>

For rcutorture tests on RCU implementations that support
force-quiescent-state operations and that set the fqs_duration module
parameter greater than zero, the fqs_task kthread will be created.
However, if the fqs_holdoff module parameter is not set, then its default
value of zero will cause fqs_task enter a long-term busy loop until
stopped by kthread_stop().  This commit therefore adds a fqs_holdoff
check before the fqs_task is created, making sure that whenever the
fqs_task is created, the fqs_holdoff will be greater than zero.

Signed-off-by: Zqiang <qiang.zhang1211@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Neeraj Upadhyay (AMD) <neeraj.iitr10@gmail.com>
---
 kernel/rcu/rcutorture.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 30fc9d34e329..a0b2520bd32b 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -3872,7 +3872,9 @@ rcu_torture_init(void)
 	}
 	if (fqs_duration < 0)
 		fqs_duration = 0;
-	if (fqs_duration) {
+	if (fqs_holdoff < 0)
+		fqs_holdoff = 0;
+	if (fqs_duration && fqs_holdoff) {
 		/* Create the fqs thread */
 		firsterr = torture_create_kthread(rcu_torture_fqs, NULL,
 						  fqs_task);
-- 
2.40.1