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From: Joel Fernandes <joel@joelfernandes.org>
Date: Mon, 18 Dec 2023 10:27:56 -0500
Message-ID: <CAEXW_YS-p9G=fLO+-vYx9RQS9oovHbVs48aPDfGcQrNWUdXwWA@mail.gmail.com>
Subject: Re: [PATCH v2] srcu: Improve comments about acceleration leak
To: Frederic Weisbecker <frederic@kernel.org>
Cc: linux-kernel@vger.kernel.org, Lai Jiangshan <jiangshanlai@gmail.com>, 
	"Paul E. McKenney" <paulmck@kernel.org>, Josh Triplett <josh@joshtriplett.org>, 
	Steven Rostedt <rostedt@goodmis.org>, Mathieu Desnoyers <mathieu.desnoyers@efficios.com>, 
	Neeraj Upadhyay <neeraj.iitr10@gmail.com>, rcu@vger.kernel.org
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On Mon, Dec 18, 2023 at 7:13=E2=80=AFAM Frederic Weisbecker <frederic@kerne=
l.org> wrote:
>
> Le Sun, Dec 17, 2023 at 09:00:15PM -0500, Joel Fernandes a =C3=A9crit :
> > "Acceleration can never fail because the state of gp_seq value used
> > for acceleration is <=3D the state of gp_seq used for advancing."
> >
> > Does that sound correct now?
>
> That can be confusing since acceleration relies on rcu_seq_snap() while
> advance relies on rcu_seq_current(). And rcu_seq_snap() returns a snapsho=
t
> that may be above the subsequent rcu_seq_current() return value.
>
> So it should rather be something like:
>
> "The base current gp_seq value used to produce the snapshot has to
> be <=3D the gp_seq used for advancing."

Yeah "base current gp_seq" though probably equally confusing sounds a
bit better, so I'll just use that instead of "state of gp_seq".

With that can I add your Review tag?

 - Joel