Re: [PATCH v3] Add generic exponentially weighted moving average (EWMA) function

[KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>]

Hi

I'm plaing this a bit and I have to say this doesn't works as I expected
because ewma_init() has very easy confusable.

so, I have one request.


> +/**
> + * ewma_init() - Initialize EWMA parameters
> + * @avg: Average structure
> + * @factor: Factor to use for the scaled up internal value. The maximum value
> + *	of averages can be UINT_MAX/(factor*weight).
> + * @weight: Exponential weight, or decay rate. This defines how fast the
> + * 	influence of older values decreases. Has to be bigger than 1.
> + *
> + * Initialize the EWMA parameters for a given struct ewma @avg.
> + */
> +struct ewma*
> +ewma_init(struct ewma *avg, const unsigned int factor,
> +	  const unsigned int weight)
> +{
> +	WARN_ON(weight <= 1 || factor == 0);
> +	avg->weight = weight;
> +	avg->factor = factor;
> +	return avg;
> +}
> +EXPORT_SYMBOL(ewma_init);

Please initalize avg->internal too.


and nit, I don't understand what you intend by 'const unsigned int'. I think
we can remove this const safely. it's more easy readable.