linux-kernel - Re: [patch V4 09/20] cpumask: Cache num_possible

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Message-ID: <fa998fb1-3054-4457-99df-c4cf1940fdc3@efficios.com>
Date: Mon, 17 Nov 2025 11:48:29 -0500
From: Mathieu Desnoyers <mathieu.desnoyers@...icios.com>
To: Thomas Gleixner <tglx@...utronix.de>, LKML <linux-kernel@...r.kernel.org>
Cc: Peter Zijlstra <peterz@...radead.org>,
 Gabriele Monaco <gmonaco@...hat.com>, Michael Jeanson
 <mjeanson@...icios.com>, Jens Axboe <axboe@...nel.dk>,
 "Paul E. McKenney" <paulmck@...nel.org>,
 "Gautham R. Shenoy" <gautham.shenoy@....com>,
 Florian Weimer <fweimer@...hat.com>, Tim Chen <tim.c.chen@...el.com>,
 Yury Norov <yury.norov@...il.com>, Shrikanth Hegde <sshegde@...ux.ibm.com>
Subject: Re: [patch V4 09/20] cpumask: Cache num_possible_cpus()

On 2025-11-16 15:48, Thomas Gleixner wrote:
> Reevaluating num_possible_cpus() over and over does not make sense. That
> becomes a constant after init as cpu_possible_mask is marked ro_after_init.
> 
> Cache the value during initialization and provide that for consumption.
> 
> Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
> Reviewed-by: Yury Norov <yury.norov@...il.com>

Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@...icios.com>

-- 
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com