Re: [PATCH V2 1/3] Calculate Thermal Pressure

[Quentin Perret]

On Tuesday 16 Apr 2019 at 15:38:39 (-0400), Thara Gopinath wrote:
> +/**
> + * Function to update thermal pressure from cooling device
> + * or any framework responsible for capping cpu maximum
> + * capacity.
> + */
> +void sched_update_thermal_pressure(struct cpumask *cpus,
> +				   unsigned long cap_max_freq,
> +				   unsigned long max_freq)
> +{
> +	int cpu;
> +	unsigned long flags = 0;
> +	struct thermal_pressure *cpu_thermal;
> +
> +	for_each_cpu(cpu, cpus) {

Is it actually required to do this for each CPU ? You could calculate
the whole thing once for the first CPU, and apply the result to all CPUs
in the policy no ? All CPUs in a policy are capped and uncapped
synchronously.

> +		cpu_thermal = per_cpu(thermal_pressure_cpu, cpu);
> +		if (!cpu_thermal)
> +			return;
> +		spin_lock_irqsave(&cpu_thermal->lock, flags);
> +		thermal_pressure_update(cpu_thermal, cap_max_freq, max_freq, 1);
> +	}
> +}