Re: [PATCH 13/17] kernel/cpu: add num_possible_cpus counter

Peter Zijlstra
2021-12-21T13:16:07Z

On Sat, Dec 18, 2021 at 01:20:09PM -0800, Yury Norov wrote:
> Similarly to the online cpus, the cpu_possible_mask is actively used
> in the kernel. This patch adds a counter for possible cpus, so that
> users that call num_possible_cpus() would know the result immediately,
> instead of calling the bitmap_weight for the mask underlying.

So what user actually cares about performance here enough to warrant
this?

> +EXPORT_SYMBOL(set_cpu_possible);

NAK