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| author |   Andrea Parri <parri.andrea@gmail.com> | 2018-02-16 12:06:13 +0100 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2018-02-19 11:11:16 -0500 |
| commit | e3f9f41757f5ce1e95ef3bc3bfb72bbcdb23ece2 (patch) | |
| tree | 6975ad4371c3284e54919d92e98a935a8111d699 /include/linux/ptr_ring.h | |
| parent | tun: export flags, uid, gid, queue information over netlink (diff) | |
| download | linux-dev-e3f9f41757f5ce1e95ef3bc3bfb72bbcdb23ece2.tar.xz linux-dev-e3f9f41757f5ce1e95ef3bc3bfb72bbcdb23ece2.zip | |
ptr_ring: Remove now-redundant smp_read_barrier_depends()
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.andrea@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: <linux-kernel@vger.kernel.org>
Cc: <netdev@vger.kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/ptr_ring.h')
| -rw-r--r-- | include/linux/ptr_ring.h | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h index b884b7794187..ddfed1dce936 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; } |