[PATCH v2 5/9] percpu: Replace smp_read_barrier_depends() with lockless_dereference()

From: Pranith Kumar
Date: Fri Nov 21 2014 - 10:09:17 EST


Recently lockless_dereference() was added which can be used in place of
hard-coding smp_read_barrier_depends(). The following PATCH makes the change.

Signed-off-by: Pranith Kumar <bobby.prani@xxxxxxxxx>
---
include/linux/percpu-refcount.h | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h
index 494ab05..3cf6759 100644
--- a/include/linux/percpu-refcount.h
+++ b/include/linux/percpu-refcount.h
@@ -128,10 +128,8 @@ static inline void percpu_ref_kill(struct percpu_ref *ref)
static inline bool __ref_is_percpu(struct percpu_ref *ref,
unsigned long __percpu **percpu_countp)
{
- unsigned long percpu_ptr = ACCESS_ONCE(ref->percpu_count_ptr);
-
/* paired with smp_store_release() in percpu_ref_reinit() */
- smp_read_barrier_depends();
+ unsigned long percpu_ptr = lockless_dereference(ref->percpu_count_ptr);

if (unlikely(percpu_ptr & __PERCPU_REF_ATOMIC))
return false;
--
1.9.1

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