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Message-Id: <1512157876-24665-8-git-send-email-paulmck@linux.vnet.ibm.com>
Date: Fri, 1 Dec 2017 11:51:03 -0800
From: "Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
To: linux-kernel@...r.kernel.org
Cc: mingo@...nel.org, jiangshanlai@...il.com, dipankar@...ibm.com,
akpm@...ux-foundation.org, mathieu.desnoyers@...icios.com,
josh@...htriplett.org, tglx@...utronix.de, peterz@...radead.org,
rostedt@...dmis.org, dhowells@...hat.com, edumazet@...gle.com,
fweisbec@...il.com, oleg@...hat.com,
"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
Ingo Molnar <mingo@...hat.com>
Subject: [PATCH tip/core/rcu 08/21] 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@...ux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Ingo Molnar <mingo@...hat.com>
---
include/linux/seqlock.h | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h
index f189a8a3bbb8..bcf4cf26b8c8 100644
--- 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;
}
--
2.5.2
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