rcutorture: Add fqs_holdoff check before fqs_task is created

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>

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 30fc9d34e3297f86c822b1db5face539af2ee83d..a0b2520bd32b6bc0c9b4fc25f6d1312c418c62be 100644 (file)
--- 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);