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Date: Tue, 30 Jan 2024 16:47:16 +0100
From: Frederic Weisbecker <frederic@kernel.org>
To: Boqun Feng <boqun.feng@gmail.com>
Cc: linux-kernel@vger.kernel.org, rcu@vger.kernel.org,
	"Paul E . McKenney" <paulmck@kernel.org>,
	Neeraj Upadhyay <neeraj.iitr10@gmail.com>,
	Joel Fernandes <joel@joelfernandes.org>,
	Josh Triplett <josh@joshtriplett.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Lai Jiangshan <jiangshanlai@gmail.com>,
	Zqiang <qiang.zhang1211@gmail.com>
Subject: Re: [PATCH 1/8] rcu/exp: Remove full barrier upon main thread wakeup
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References: <20240129232349.3170819-1-boqun.feng@gmail.com>
 <20240129232349.3170819-2-boqun.feng@gmail.com>
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Le Mon, Jan 29, 2024 at 03:23:39PM -0800, Boqun Feng a ?crit :
> From: Frederic Weisbecker <frederic@kernel.org>
> 
> When an expedited grace period is ending, care must be taken so that all
> the quiescent states propagated up to the root are correctly ordered
> against the wake up of the main expedited grace period workqueue.
> 
> This ordering is already carried through the root rnp locking augmented
> by an smp_mb__after_unlock_lock() barrier.
> 
> Therefore the explicit smp_mb() placed before the wake up is not needed
> and can be removed.
> 
> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

[Offlist]

For further posting, don't forget to add your own SoB while posting patches :-)

Thanks!