Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     "Paul E. McKenney" <paulmck@kernel.org>,
        Neeraj Upadhyay <neeraju@codeaurora.org>,
        Sasha Levin <sashal@kernel.org>, josh@joshtriplett.org,
        rcu@vger.kernel.org
Subject: [PATCH AUTOSEL 5.15 017/146] rcu-tasks: Move RTGS_WAIT_CBS to beginning of rcu_tasks_kthread() loop
Date:   Mon,  8 Nov 2021 12:42:44 -0500
Message-Id: <20211108174453.1187052-17-sashal@kernel.org>
In-Reply-To: <20211108174453.1187052-1-sashal@kernel.org>
References: <20211108174453.1187052-1-sashal@kernel.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: "Paul E. McKenney" <paulmck@kernel.org>

[ Upstream commit 0db7c32ad3160ae06f497d48a74bd46a2a35e6bf ]

Early in debugging, it made some sense to differentiate the first
iteration from subsequent iterations, but now this just causes confusion.
This commit therefore moves the "set_tasks_gp_state(rtp, RTGS_WAIT_CBS)"
statement to the beginning of the "for" loop in rcu_tasks_kthread().

Reported-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/rcu/tasks.h | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index 806160c44b172..6591914af4864 100644
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -197,6 +197,7 @@ static int __noreturn rcu_tasks_kthread(void *arg)
 	 * This loop is terminated by the system going down.  ;-)
 	 */
 	for (;;) {
+		set_tasks_gp_state(rtp, RTGS_WAIT_CBS);
 
 		/* Pick up any new callbacks. */
 		raw_spin_lock_irqsave(&rtp->cbs_lock, flags);
@@ -236,8 +237,6 @@ static int __noreturn rcu_tasks_kthread(void *arg)
 		}
 		/* Paranoid sleep to keep this from entering a tight loop */
 		schedule_timeout_idle(rtp->gp_sleep);
-
-		set_tasks_gp_state(rtp, RTGS_WAIT_CBS);
 	}
 }
 
-- 
2.33.0