linux-kernel - Re: [PATCH 15/17] kernel/cpu: add num_active

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Message-ID: <YcHS7c7zWVrLhIfV@hirez.programming.kicks-ass.net>
Date:   Tue, 21 Dec 2021 14:13:17 +0100
From:   Peter Zijlstra <peterz@...radead.org>
To:     Yury Norov <yury.norov@...il.com>
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Subject: Re: [PATCH 15/17] kernel/cpu: add num_active_cpu counter

On Sat, Dec 18, 2021 at 01:20:11PM -0800, Yury Norov wrote:
> Similarly to the online cpus, the cpu_active_mask is actively used
> in the kernel. This patch adds a counter for active cpus, so that
> users that call num_active_cpus() would know the result immediately,
> instead of calling the bitmap_weight for the mask.

Who cares about num_active_cpus() ?

> +EXPORT_SYMBOL(set_cpu_active);

NAK, this should *never*ever* be used from a module.