Block layer need to call this function after holding rcu lock in a real hot path, so introduce this helper.
Cc: Bart Van Assche <[email protected]> Cc: Tejun Heo <[email protected]> Signed-off-by: Ming Lei <[email protected]> --- include/linux/percpu-refcount.h | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h index c13dceb87b60..a0f22586a28d 100644 --- a/include/linux/percpu-refcount.h +++ b/include/linux/percpu-refcount.h @@ -221,6 +221,21 @@ static inline bool percpu_ref_tryget(struct percpu_ref *ref) return ret; } +static inline bool __percpu_ref_tryget_live(struct percpu_ref *ref) +{ + unsigned long __percpu *percpu_count; + bool ret = false; + + if (__ref_is_percpu(ref, &percpu_count)) { + this_cpu_inc(*percpu_count); + ret = true; + } else if (!(ref->percpu_count_ptr & __PERCPU_REF_DEAD)) { + ret = atomic_long_inc_not_zero(&ref->count); + } + + return ret; +} + /** * percpu_ref_tryget_live - try to increment a live percpu refcount * @ref: percpu_ref to try-get @@ -238,18 +253,10 @@ static inline bool percpu_ref_tryget(struct percpu_ref *ref) */ static inline bool percpu_ref_tryget_live(struct percpu_ref *ref) { - unsigned long __percpu *percpu_count; - bool ret = false; + bool ret; rcu_read_lock_sched(); - - if (__ref_is_percpu(ref, &percpu_count)) { - this_cpu_inc(*percpu_count); - ret = true; - } else if (!(ref->percpu_count_ptr & __PERCPU_REF_DEAD)) { - ret = atomic_long_inc_not_zero(&ref->count); - } - + ret = __percpu_ref_tryget_live(ref); rcu_read_unlock_sched(); return ret; -- 2.9.5
