diff options
| -rw-r--r-- | include/linux/rwsem.h | 12 | ||||
| -rw-r--r-- | kernel/locking/rwsem.c | 14 |
2 files changed, 19 insertions, 7 deletions
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index c8b543d428b0..544853bed5b9 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -132,6 +132,18 @@ static inline int rwsem_is_contended(struct rw_semaphore *sem) return !list_empty(&sem->wait_list); } +#if defined(CONFIG_DEBUG_RWSEMS) || defined(CONFIG_DETECT_HUNG_TASK_BLOCKER) +/* + * Return just the real task structure pointer of the owner + */ +extern struct task_struct *rwsem_owner(struct rw_semaphore *sem); + +/* + * Return true if the rwsem is owned by a reader. + */ +extern bool is_rwsem_reader_owned(struct rw_semaphore *sem); +#endif + #else /* !CONFIG_PREEMPT_RT */ #include <linux/rwbase_rt.h> diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index 2ddb827e3bea..a310eb9896de 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -181,11 +181,11 @@ static inline void rwsem_set_reader_owned(struct rw_semaphore *sem) __rwsem_set_reader_owned(sem, current); } -#ifdef CONFIG_DEBUG_RWSEMS +#if defined(CONFIG_DEBUG_RWSEMS) || defined(CONFIG_DETECT_HUNG_TASK_BLOCKER) /* * Return just the real task structure pointer of the owner */ -static inline struct task_struct *rwsem_owner(struct rw_semaphore *sem) +struct task_struct *rwsem_owner(struct rw_semaphore *sem) { return (struct task_struct *) (atomic_long_read(&sem->owner) & ~RWSEM_OWNER_FLAGS_MASK); @@ -194,7 +194,7 @@ static inline struct task_struct *rwsem_owner(struct rw_semaphore *sem) /* * Return true if the rwsem is owned by a reader. */ -static inline bool is_rwsem_reader_owned(struct rw_semaphore *sem) +bool is_rwsem_reader_owned(struct rw_semaphore *sem) { /* * Check the count to see if it is write-locked. @@ -207,10 +207,10 @@ static inline bool is_rwsem_reader_owned(struct rw_semaphore *sem) } /* - * With CONFIG_DEBUG_RWSEMS configured, it will make sure that if there - * is a task pointer in owner of a reader-owned rwsem, it will be the - * real owner or one of the real owners. The only exception is when the - * unlock is done by up_read_non_owner(). + * With CONFIG_DEBUG_RWSEMS or CONFIG_DETECT_HUNG_TASK_BLOCKER configured, + * it will make sure that the owner field of a reader-owned rwsem either + * points to a real reader-owner(s) or gets cleared. The only exception is + * when the unlock is done by up_read_non_owner(). */ static inline void rwsem_clear_reader_owned(struct rw_semaphore *sem) { |