Re: [PATCH v6 2/2] cpuidle: teo: Introduce util-awareness

[Qais Yousef <qyousef@layalina.io>]

Hi Kajetan

On 01/05/23 14:51, Kajetan Puchalski wrote:

[...]

> @@ -510,9 +598,11 @@ static int teo_enable_device(struct cpuidle_driver *drv,
>  			     struct cpuidle_device *dev)
>  {
>  	struct teo_cpu *cpu_data = per_cpu_ptr(&teo_cpus, dev->cpu);
> +	unsigned long max_capacity = arch_scale_cpu_capacity(dev->cpu);
>  	int i;
>  
>  	memset(cpu_data, 0, sizeof(*cpu_data));
> +	cpu_data->util_threshold = max_capacity >> UTIL_THRESHOLD_SHIFT;

Given that utilization is invariant, why do we set the threshold based on
cpu capacity?

I'm not sure if this is a problem, but on little cores this threshold would be
too low. Given that util is invariant - I wondered if we need to have a single
threshold for all type of CPUs instead. Have you tried something like that
while developing the patch?


Thanks

--
Qais Yousef