Because READ_ONCE() now implies smp_read_barrier_depends(), the
smp_read_barrier_depends() in __ptr_ring_consume() is redundant;
this commit removes it and updates the comments.
Signed-off-by: Andrea Parri <parri.and...@gmail.com>
Cc: "David S. Miller" <da...@davemloft.net>
Cc: "Michael S. Tsirkin" <m...@redhat.com>
Cc: Jason Wang <jasow...@redhat.com>
Cc: John Fastabend <john.fastab...@gmail.com>
Cc: Eric Dumazet <eduma...@google.com>
Cc: <linux-ker...@vger.kernel.org>
Cc: <netdev@vger.kernel.org>
---
include/linux/ptr_ring.h | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h
index b884b7794187e..ddfed1dce9369 100644
--- a/include/linux/ptr_ring.h
+++ b/include/linux/ptr_ring.h
@@ -296,13 +296,14 @@ static inline void *__ptr_ring_consume(struct ptr_ring *r)
{
void *ptr;
+ /* The READ_ONCE in __ptr_ring_peek guarantees that anyone
+ * accessing data through the pointer is up to date. Pairs
+ * with smp_wmb in __ptr_ring_produce.
+ */
ptr = __ptr_ring_peek(r);
if (ptr)
__ptr_ring_discard_one(r);
- /* Make sure anyone accessing data through the pointer is up to date. */
- /* Pairs with smp_wmb in __ptr_ring_produce. */
- smp_read_barrier_depends();
return ptr;
}
--
2.7.4
