[patch V2 14/15] locking/rtmutex: Restrict the trylock WARN_ON() to debug

From: Thomas Gleixner
Date: Fri Mar 26 2021 - 12:03:00 EST


The warning as written is expensive and not really required for a
production kernel. Make it depend on rt mutex debugging and use !in_task()
for the condition which generates far better code and gives the same
answer.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
kernel/locking/rtmutex.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -1456,7 +1456,7 @@ int __sched rt_mutex_trylock(struct rt_m
{
int ret;

- if (WARN_ON_ONCE(in_irq() || in_nmi() || in_serving_softirq()))
+ if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES) && WARN_ON_ONCE(!in_task()))
return 0;

/*