#include <stdio.h>

#define HZ			1000
#define MIN_TIMESLICE		( 10 * HZ / 1000)
#define MAX_TIMESLICE		(200 * HZ / 1000)
#define MAX_USER_RT_PRIO	100
#define MAX_RT_PRIO		MAX_USER_RT_PRIO
#define MAX_PRIO		(MAX_RT_PRIO + 40)
#define NICE_TO_PRIO(nice)	(MAX_RT_PRIO + (nice) + 20)
#define USER_PRIO(p)		((p)-MAX_RT_PRIO)
#define MAX_USER_PRIO		(USER_PRIO(MAX_PRIO))

#define BASE_TIMESLICE(p)	(MIN_TIMESLICE + \
	((MAX_TIMESLICE - MIN_TIMESLICE) * (MAX_PRIO-1-p)/(MAX_USER_PRIO - 1)))

#define BASE_TIMESLICE2(p)	(MAX_TIMESLICE - \
	((MAX_TIMESLICE - MIN_TIMESLICE) * (MAX_PRIO-1-p)/(MAX_USER_PRIO - 1)))

#define BASE_TIMESLICE3(p)	(prio < MAX_RT_PRIO ? MIN_TIMESLICE : (MAX_TIMESLICE - \
	((MAX_TIMESLICE - MIN_TIMESLICE) * (MAX_PRIO-1-p)/(MAX_USER_PRIO - 1))))

int main(int argc, char *argv[])
{
	// original timeslice calculation
	for (int nice = -20; nice <= 19; nice++)
		printf("nice: %d, timeslice: %d ms\n", nice, BASE_TIMESLICE(NICE_TO_PRIO(nice)) * 1000 / HZ);

	printf("\n");

	// reversed timeslice calculation
	for (int nice = -20; nice <= 19; nice++)
		printf("nice: %d, timeslice: %d ms\n", nice, BASE_TIMESLICE2(NICE_TO_PRIO(nice)) * 1000 / HZ);

	printf("\n");

	// dynamic priority based timeslice calculation
	for (int prio = 0; prio < MAX_PRIO; prio++)
		printf("prio: %d, timeslice: %d ms\n", prio, BASE_TIMESLICE3(prio) * 1000 / HZ);

	return 0;
}