[patch 16/19] rcu: Prevent false positive softirq warning on RT

Thomas Gleixner
2020-11-13T14:24:39Z

Soft interrupt disabled sections can legitimately be preempted or schedule
out when blocking on a lock on RT enabled kernels so the RCU preempt check
warning has to be disabled for RT kernels.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
include/linux/rcupdate.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -319,7 +319,8 @@ static inline void rcu_preempt_sleep_che
#define rcu_sleep_check() \
do { \
rcu_preempt_sleep_check(); \
- RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map), \
+ if (!IS_ENABLED(CONFIG_PREEMPT_RT)) \
+ RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map), \
"Illegal context switch in RCU-bh read-side critical section"); \
RCU_LOCKDEP_WARN(lock_is_held(&rcu_sched_lock_map), \
"Illegal context switch in RCU-sched read-side critical section"); \