Commit a10e3cbf authored by linke li's avatar linke li Committed by Uladzislau Rezki (Sony)
Browse files

rcutorture: Re-use value stored to ->rtort_pipe_count instead of re-reading 



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: default avatarlinke li <lilinke99@qq.com>
Reviewed-by: default avatarJoel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarUladzislau Rezki (Sony) <urezki@gmail.com>
parent 8b9b443f

kernel/rcu/rcutorture.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

	}