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From: Andrew Morton <akpm@linux-foundation.org>
To: Alexey Dobriyan <adobriyan@gmail.com>
Cc: tglx@linutronix.de, peterz@infradead.org, yury.norov@gmail.com,
	linux@rasmusvillemoes.dk, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] cpu: memoise number of possible cpus
Date: Thu, 18 Apr 2024 13:26:00 -0700	[thread overview]
Message-ID: <20240418132600.ffbf4d53b39eaaeaffc28198@linux-foundation.org> (raw)
In-Reply-To: <20240418041927.3903-1-adobriyan@gmail.com>

On Thu, 18 Apr 2024 07:19:27 +0300 Alexey Dobriyan <adobriyan@gmail.com> wrote:

> cpu_possible_mask is fixed after boot, so it makes sense
> to calculate number of possible cpus to
> a) make num_possible_cpus() faster (distros ship with _large_ NR_CPUS),
> b) unscrew codegen elsewhere replacing function call
>    with simple memory load.

There are a lot of calls to set_cpu_possible().  Perhaps calculating
num_possible_cpus within there would reduce risk of things getting out
of sync, either now or in the future.

reset_cpu_possible_mask() appears to have no callers.  Kill?



  reply	other threads:[~2024-04-18 20:26 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-18  4:19 [PATCH] cpu: memoise number of possible cpus Alexey Dobriyan
2024-04-18 20:26 ` Andrew Morton [this message]
2024-04-18 20:27   ` Andrew Morton
2024-04-19  5:32 ` Thomas Gleixner

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