Two small changes. * Unlike most init functions, percpu_ref_init() allocates memory and may fail. Let's mark it with __must_check in case the caller forgets.
* percpu_ref_kill_rcu() is unnecessarily using ACCESS_ONCE() to dereference @ref->pcpu_count, which can be misleading. The pointer is guaranteed to be valid and visible and can't change underneath the function. Drop ACCESS_ONCE(). Signed-off-by: Tejun Heo <[email protected]> --- include/linux/percpu-refcount.h | 3 ++- lib/percpu-refcount.c | 4 +--- 2 files changed, 3 insertions(+), 4 deletions(-) --- a/include/linux/percpu-refcount.h +++ b/include/linux/percpu-refcount.h @@ -67,7 +67,8 @@ struct percpu_ref { struct rcu_head rcu; }; -int percpu_ref_init(struct percpu_ref *ref, percpu_ref_func_t *release); +int __must_check percpu_ref_init(struct percpu_ref *ref, + percpu_ref_func_t *release); void percpu_ref_kill_and_confirm(struct percpu_ref *ref, percpu_ref_func_t *confirm_kill); --- a/lib/percpu-refcount.c +++ b/lib/percpu-refcount.c @@ -57,12 +57,10 @@ int percpu_ref_init(struct percpu_ref *r static void percpu_ref_kill_rcu(struct rcu_head *rcu) { struct percpu_ref *ref = container_of(rcu, struct percpu_ref, rcu); - unsigned __percpu *pcpu_count; + unsigned __percpu *pcpu_count = ref->pcpu_count; unsigned count = 0; int cpu; - pcpu_count = ACCESS_ONCE(ref->pcpu_count); - /* Mask out PCPU_REF_DEAD */ pcpu_count = (unsigned __percpu *) (((unsigned long) pcpu_count) & ~PCPU_STATUS_MASK); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
