On Fri, Nov 03, 2023 at 03:26:39PM +0800, Zqiang wrote:
> For rcutorture tests that support fqs operations and set fqs_duration
> greater than zero, the fqs_task kthread will be created. but if the
> fqs_holdoff is not set, the default value is zero, this cause fqs_task
> enter a long-term busy loop and won't voluntarily give up the CPU until
> stopped by kthread_stop(). this commit therefore add for fqs_holdoff check
> before the fqs_task is created, make sure the fqs_task is created when
> the fqs_holdoff is also greater than zero.
>
> Signed-off-by: Zqiang <qiang.zhang1211@xxxxxxxxx>
Queued and pushed, thank you!
Thanx, Paul
------------------------------------------------------------------------
commit 964f05cdec9f84be006fd836d64d04e79a50cb31
Author: Zqiang <qiang.zhang1211@xxxxxxxxx>
Date: Fri Nov 3 15:26:39 2023 +0800
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@xxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 83999e57b3eaf..9f0e6c1cad443 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -3886,7 +3886,9 @@ 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);
