[PATCH tip/core/rcu 18/19] scftorture: Add cond_resched() to test loop

From: paulmck
Date: Mon Aug 31 2020 - 14:08:16 EST


From: "Paul E. McKenney" <paulmck@xxxxxxxxxx>

Although the test loop does randomly delay, which would provide quiescent
states and so forth, it is possible for there to be a series of long
smp_call_function*() handler runtimes with no delays, which results in
softlockup and RCU CPU stall warning messages. This commit therefore
inserts a cond_resched() into the main test loop.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
kernel/scftorture.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/kernel/scftorture.c b/kernel/scftorture.c
index fc22bcc..554a521 100644
--- a/kernel/scftorture.c
+++ b/kernel/scftorture.c
@@ -420,6 +420,7 @@ static int scftorture_invoker(void *arg)
set_cpus_allowed_ptr(current, cpumask_of(cpu));
was_offline = false;
}
+ cond_resched();
} while (!torture_must_stop());

VERBOSE_SCFTORTOUT("scftorture_invoker %d ended", scfp->cpu);
--
2.9.5