From: Tejun Heo <[email protected]> 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]> (cherry picked from commit acac7883ee7bcc32476963bce7baf73d44574dd1) Signed-off-by: Vladimir Davydov <[email protected]> --- include/linux/percpu-refcount.h | 3 ++- lib/percpu-refcount.c | 4 +--- 2 files changed, 3 insertions(+), 4 deletions(-) diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h index b61bd6f23985..8146aa9cd89e 100644 --- a/include/linux/percpu-refcount.h +++ b/include/linux/percpu-refcount.h @@ -66,7 +66,8 @@ 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(struct percpu_ref *ref); #define PCPU_STATUS_BITS 2 diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c index 9a78e55fa48f..b35eaac2954f 100644 --- a/lib/percpu-refcount.c +++ b/lib/percpu-refcount.c @@ -57,12 +57,10 @@ int percpu_ref_init(struct percpu_ref *ref, percpu_ref_func_t *release) 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); -- 2.1.4 _______________________________________________ Devel mailing list [email protected] https://lists.openvz.org/mailman/listinfo/devel
