Re: [PATCH 1/4] sched/fair: Generalize the load/util averages resolution definition

[Peter Zijlstra]

On Mon, Oct 05, 2015 at 01:56:56AM +0800, Yuyang Du wrote:
> Metric needs certain resolution to allow detail we can look into,
> which also determines the range of the metric.
> 
> For instance, increasing the resolution of [0, 1] (two levels), one
> can multiply 1024 and get [0..1024] (1025 levels).
> 

>  /*
> + * Integer metrics need certain resolution to allow how much detail we
> + * can look into, e.g., load, load_avg, util_avg, freq, and capacity.
> + * We define a basic resolution constant number, and then formalize
> + * all these metrics based on that basic resolution.
> + */
> +# define SCHED_RESOLUTION_SHIFT	10
> +# define SCHED_RESOLUTION_SCALE	(1L << SCHED_RESOLUTION_SHIFT)
> +
> +/*

I find all that most confusing, maybe just refer to fixed point
arithmetic, that's a well defined and well understood concept.
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