diff options
| -rw-r--r-- | include/linux/percpu-rwsem.h | 6 | ||||
| -rw-r--r-- | kernel/locking/percpu-rwsem.c | 6 |
2 files changed, 12 insertions, 0 deletions
diff --git a/include/linux/percpu-rwsem.h b/include/linux/percpu-rwsem.h index 5fda40f97fe9..36b942b67b7d 100644 --- a/include/linux/percpu-rwsem.h +++ b/include/linux/percpu-rwsem.h @@ -121,9 +121,15 @@ static inline void percpu_up_read(struct percpu_rw_semaphore *sem) preempt_enable(); } +extern bool percpu_is_read_locked(struct percpu_rw_semaphore *); extern void percpu_down_write(struct percpu_rw_semaphore *); extern void percpu_up_write(struct percpu_rw_semaphore *); +static inline bool percpu_is_write_locked(struct percpu_rw_semaphore *sem) +{ + return atomic_read(&sem->block); +} + extern int __percpu_init_rwsem(struct percpu_rw_semaphore *, const char *, struct lock_class_key *); diff --git a/kernel/locking/percpu-rwsem.c b/kernel/locking/percpu-rwsem.c index 5fe4c5495ba3..185bd1c906b0 100644 --- a/kernel/locking/percpu-rwsem.c +++ b/kernel/locking/percpu-rwsem.c @@ -192,6 +192,12 @@ EXPORT_SYMBOL_GPL(__percpu_down_read); __sum; \ }) +bool percpu_is_read_locked(struct percpu_rw_semaphore *sem) +{ + return per_cpu_sum(*sem->read_count) != 0 && !atomic_read(&sem->block); +} +EXPORT_SYMBOL_GPL(percpu_is_read_locked); + /* * Return true if the modular sum of the sem->read_count per-CPU variable is * zero. If this sum is zero, then it is stable due to the fact that if any |