diff options
| -rw-r--r-- | include/linux/percpu-rwsem.h | 10 | ||||
| -rw-r--r-- | kernel/locking/percpu-rwsem.c | 2 |
2 files changed, 8 insertions, 4 deletions
diff --git a/include/linux/percpu-rwsem.h b/include/linux/percpu-rwsem.h index 4ceaa1921951..bb5b71c1e446 100644 --- a/include/linux/percpu-rwsem.h +++ b/include/linux/percpu-rwsem.h @@ -59,8 +59,9 @@ static inline void percpu_down_read(struct percpu_rw_semaphore *sem) * and that once the synchronize_rcu() is done, the writer will see * anything we did within this RCU-sched read-size critical section. */ - __this_cpu_inc(*sem->read_count); - if (unlikely(!rcu_sync_is_idle(&sem->rss))) + if (likely(rcu_sync_is_idle(&sem->rss))) + __this_cpu_inc(*sem->read_count); + else __percpu_down_read(sem, false); /* Unconditional memory barrier */ /* * The preempt_enable() prevents the compiler from @@ -77,8 +78,9 @@ static inline bool percpu_down_read_trylock(struct percpu_rw_semaphore *sem) /* * Same as in percpu_down_read(). */ - __this_cpu_inc(*sem->read_count); - if (unlikely(!rcu_sync_is_idle(&sem->rss))) + if (likely(rcu_sync_is_idle(&sem->rss))) + __this_cpu_inc(*sem->read_count); + else ret = __percpu_down_read(sem, true); /* Unconditional memory barrier */ preempt_enable(); /* diff --git a/kernel/locking/percpu-rwsem.c b/kernel/locking/percpu-rwsem.c index 969389df6eee..becf925b27b5 100644 --- a/kernel/locking/percpu-rwsem.c +++ b/kernel/locking/percpu-rwsem.c @@ -47,6 +47,8 @@ EXPORT_SYMBOL_GPL(percpu_free_rwsem); bool __percpu_down_read(struct percpu_rw_semaphore *sem, bool try) { + __this_cpu_inc(*sem->read_count); + /* * Due to having preemption disabled the decrement happens on * the same CPU as the increment, avoiding the |