[PATCH] prinkt/nbcon: Add a scheduling point to nbcon_kthread_func().

[Sebastian Andrzej Siewior <bigeasy@linutronix.de>]

Constant printing can lead to a CPU hog in nbcon_kthread_func(). The
context is preemptible but on !PREEMPT kernels there is no explicit
preemption point which leads softlockup warnings.

Add an explicit preemption point in nbcon_kthread_func().

Reported-by: Derek Barbosa <debarbos@redhat.com>
Link: https://lore.kernel.org/ZnHF5j1DUDjN1kkq@debarbos-thinkpadt14sgen2i.remote.csb
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 kernel/printk/nbcon.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/printk/nbcon.c b/kernel/printk/nbcon.c
index bb9689f94d302..0813ce88a49c5 100644
--- a/kernel/printk/nbcon.c
+++ b/kernel/printk/nbcon.c
@@ -1119,6 +1119,7 @@ static int nbcon_kthread_func(void *__console)
 		}
 
 		console_srcu_read_unlock(cookie);
+		cond_resched();
 
 	} while (backlog);
 
-- 
2.45.2