Re: [PATCH 1/4] cpufreq: Add a cpufreq pressure feedback for the scheduler

[Lukasz Luba <lukasz.luba@arm.com>]

On 12/12/23 14:27, Vincent Guittot wrote:
> Provide to the scheduler a feedback about the temporary max available
> capacity. Unlike arch_update_thermal_pressure, this doesn't need to be
> filtered as the pressure will happen for dozens ms or more.
> 
> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
> ---
>   drivers/cpufreq/cpufreq.c | 48 +++++++++++++++++++++++++++++++++++++++
>   include/linux/cpufreq.h   | 10 ++++++++
>   2 files changed, 58 insertions(+)
> 
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index 44db4f59c4cc..7d5f71be8d29 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -2563,6 +2563,50 @@ int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
>   }
>   EXPORT_SYMBOL(cpufreq_get_policy);
>   
> +DEFINE_PER_CPU(unsigned long, cpufreq_pressure);
> +EXPORT_PER_CPU_SYMBOL_GPL(cpufreq_pressure);

Why do we export this variable when we have get/update functions?
Do we expect modules would manipulate those per-cpu variables
independently and not like we do per-cpumask in the update func.?