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From: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
To: "Paul E . McKenney" <paulmck@kernel.org>
Cc: RCU <rcu@vger.kernel.org>,
	Neeraj upadhyay <Neeraj.Upadhyay@amd.com>,
	Boqun Feng <boqun.feng@gmail.com>,
	Hillf Danton <hdanton@sina.com>,
	Joel Fernandes <joel@joelfernandes.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Uladzislau Rezki <urezki@gmail.com>,
	Oleksiy Avramchenko <oleksiy.avramchenko@sony.com>,
	Frederic Weisbecker <frederic@kernel.org>,
	linke li <lilinke99@qq.com>,
	Linus Torvalds <torvalds@linux-foundation.org>
Subject: [PATCH 41/48] rcutorture: Re-use value stored to ->rtort_pipe_count instead of re-reading
Date: Tue,  7 May 2024 11:35:23 +0200
Message-Id: <20240507093530.3043-42-urezki@gmail.com>
In-Reply-To: <20240507093530.3043-1-urezki@gmail.com>
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From: linke li <lilinke99@qq.com>

Currently, the rcu_torture_pipe_update_one() writes the value (i + 1)
to rp->rtort_pipe_count, then immediately re-reads it in order to compare
it to RCU_TORTURE_PIPE_LEN.  This re-read is pointless because no other
update to rp->rtort_pipe_count can occur at this point.  This commit
therefore instead re-uses the (i + 1) value stored in the comparison
instead of re-reading rp->rtort_pipe_count.

Signed-off-by: linke li <lilinke99@qq.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
---
 kernel/rcu/rcutorture.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 0cb5452ecd94..dd7d5ba45740 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -467,7 +467,7 @@ rcu_torture_pipe_update_one(struct rcu_torture *rp)
 	atomic_inc(&rcu_torture_wcount[i]);
 	WRITE_ONCE(rp->rtort_pipe_count, i + 1);
 	ASSERT_EXCLUSIVE_WRITER(rp->rtort_pipe_count);
-	if (rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
+	if (i + 1 >= RCU_TORTURE_PIPE_LEN) {
 		rp->rtort_mbtest = 0;
 		return true;
 	}
-- 
2.39.2