Re: [o(1) sched J0] higher priority smaller timeslices, in fact

[Davide Libenzi]

On Wed, 16 Jan 2002, Alexei Podtelezhnikov wrote:

>
> The comment and the actual macros are inconsistent.
> positive number * (19-n) is a decreasing function of n!

# man nice

> + * The higher a process's priority, the bigger timeslices
> + * it gets during one round of execution. But even the lowest
> + * priority process gets MIN_TIMESLICE worth of execution time.
> + */
>
> -#define NICE_TO_TIMESLICE(n)   (MIN_TIMESLICE + \
> -	((MAX_TIMESLICE - MIN_TIMESLICE) * (19 - (n))) / 39)
> +#define NICE_TO_TIMESLICE(n) (MIN_TIMESLICE + \
> +	((MAX_TIMESLICE - MIN_TIMESLICE) * (19-(n))) / 39)
>
> I still suggest a different set as faster and more readable at least to
> me. Just two operations instead of 4!

this seems quite readable to me, it's the equation at page 1 of any know
linear geometry book.

- Davide