From: Thomas Gleixner Date: Tue, 9 Mar 2021 09:55:58 +0100 Subject: [PATCH 20/20] rcu: Prevent false positive softirq warning on RT 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 Tested-by: Sebastian Andrzej Siewior Reviewed-by: Paul E. McKenney Signed-off-by: Sebastian Andrzej Siewior --- include/linux/rcupdate.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -328,7 +328,8 @@ 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"); \