seqlock: Remove now-redundant smp_read_barrier_depends()

READ_ONCE() now implies smp_read_barrier_depends(), so this patch
removes the now-redundant smp_read_barrier_depends() from
raw_read_seqcount_latch().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>

diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h
index f189a8a..bcf4cf2 100644 (file)
--- a/include/linux/seqlock.h
+++ b/include/linux/seqlock.h
@@ -278,9 +278,8 @@ static inline void raw_write_seqcount_barrier(seqcount_t *s)
 
 static inline int raw_read_seqcount_latch(seqcount_t *s)
 {
-       int seq = READ_ONCE(s->sequence);
        /* Pairs with the first smp_wmb() in raw_write_seqcount_latch() */
-       smp_read_barrier_depends();
+       int seq = READ_ONCE(s->sequence); /* ^^^ */
        return seq;
 }