From 6251f9976af7656b6970a8820153f356430f5de2 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 24 Sep 2014 13:31:48 -0400 Subject: percpu_ref: minor code and comment updates * Some comments became stale. Updated. * percpu_ref_tryget() unnecessarily initializes @ret. Removed. * A blank line removed from percpu_ref_kill_rcu(). * Explicit function name in a WARN format string replaced with __func__. * WARN_ON() in percpu_ref_reinit() converted to WARN_ON_ONCE(). Signed-off-by: Tejun Heo Reviewed-by: Kent Overstreet --- include/linux/percpu-refcount.h | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) (limited to 'include/linux/percpu-refcount.h') diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h index f015f139d491..d44b027f74fd 100644 --- a/include/linux/percpu-refcount.h +++ b/include/linux/percpu-refcount.h @@ -115,8 +115,10 @@ static inline bool __pcpu_ref_alive(struct percpu_ref *ref, * percpu_ref_get - increment a percpu refcount * @ref: percpu_ref to get * - * Analagous to atomic_inc(). - */ + * Analagous to atomic_long_inc(). + * + * This function is safe to call as long as @ref is between init and exit. + */ static inline void percpu_ref_get(struct percpu_ref *ref) { unsigned long __percpu *pcpu_count; @@ -138,12 +140,12 @@ static inline void percpu_ref_get(struct percpu_ref *ref) * Increment a percpu refcount unless its count already reached zero. * Returns %true on success; %false on failure. * - * The caller is responsible for ensuring that @ref stays accessible. + * This function is safe to call as long as @ref is between init and exit. */ static inline bool percpu_ref_tryget(struct percpu_ref *ref) { unsigned long __percpu *pcpu_count; - int ret = false; + int ret; rcu_read_lock_sched(); @@ -166,12 +168,13 @@ static inline bool percpu_ref_tryget(struct percpu_ref *ref) * Increment a percpu refcount unless it has already been killed. Returns * %true on success; %false on failure. * - * Completion of percpu_ref_kill() in itself doesn't guarantee that tryget - * will fail. For such guarantee, percpu_ref_kill_and_confirm() should be - * used. After the confirm_kill callback is invoked, it's guaranteed that - * no new reference will be given out by percpu_ref_tryget(). + * Completion of percpu_ref_kill() in itself doesn't guarantee that this + * function will fail. For such guarantee, percpu_ref_kill_and_confirm() + * should be used. After the confirm_kill callback is invoked, it's + * guaranteed that no new reference will be given out by + * percpu_ref_tryget_live(). * - * The caller is responsible for ensuring that @ref stays accessible. + * This function is safe to call as long as @ref is between init and exit. */ static inline bool percpu_ref_tryget_live(struct percpu_ref *ref) { @@ -196,6 +199,8 @@ static inline bool percpu_ref_tryget_live(struct percpu_ref *ref) * * Decrement the refcount, and if 0, call the release function (which was passed * to percpu_ref_init()) + * + * This function is safe to call as long as @ref is between init and exit. */ static inline void percpu_ref_put(struct percpu_ref *ref) { @@ -216,6 +221,8 @@ static inline void percpu_ref_put(struct percpu_ref *ref) * @ref: percpu_ref to test * * Returns %true if @ref reached zero. + * + * This function is safe to call as long as @ref is between init and exit. */ static inline bool percpu_ref_is_zero(struct percpu_ref *ref) { -- cgit