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From: "Joel Fernandes (Google)" <joel@joelfernandes.org>
To: linux-kernel@vger.kernel.org
Cc: "Joel Fernandes (Google)" <joel@joelfernandes.org>,
	Josh Triplett <josh@joshtriplett.org>,
	Lai Jiangshan <jiangshanlai@gmail.com>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Neeraj Upadhyay <neeraju@codeaurora.org>,
	"Paul E. McKenney" <paulmck@kernel.org>,
	rcu@vger.kernel.org, Steven Rostedt <rostedt@goodmis.org>
Subject: [PATCH v2 2/3] rcu/tree: Clarify comments about FQS loop reporting quiescent states
Date: Thu, 30 Jul 2020 20:40:11 -0400
Message-ID: <20200731004012.2324147-2-joel@joelfernandes.org> (raw)
In-Reply-To: <20200731004012.2324147-1-joel@joelfernandes.org>

At least since v4.19, the FQS loop no longer reports quiescent states
unless it is a dire situation where an offlined CPU failed to report
a quiescent state. Let us clarify the comment in rcu_gp_init() inorder
to keep the comment current.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
 kernel/rcu/tree.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 6b6fc28bb670..a621932cc385 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1701,8 +1701,8 @@ static bool rcu_gp_init(void)
 	 * Apply per-leaf buffered online and offline operations to the
-	 * rcu_node tree.  Note that this new grace period need not wait
-	 * for subsequent online CPUs, and that quiescent-state forcing
+	 * rcu_node tree.  Note that this new grace period need not wait for
+	 * subsequent online CPUs, and that RCU hooks in CPU offlining path
 	 * will handle subsequent offline CPUs.
 	rcu_state.gp_state = RCU_GP_ONOFF;

  reply index

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-31  0:40 [PATCH v2 1/3] rcu/tree: Add a warning if CPU being onlined did not report QS already Joel Fernandes (Google)
2020-07-31  0:40 ` Joel Fernandes (Google) [this message]
2020-07-31  0:40 ` [PATCH v2 3/3] rcu/tree: Make FQS complaining about offline CPU more aggressive Joel Fernandes (Google)
2020-07-31  1:36   ` Paul E. McKenney

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