[deliverable/linux.git] / include / linux / sched / prio.h

#ifndef _SCHED_PRIO_H
#define _SCHED_PRIO_H

#define MAX_NICE	19
#define MIN_NICE	-20
#define NICE_WIDTH	(MAX_NICE - MIN_NICE + 1)

/*
 * Priority of a process goes from 0..MAX_PRIO-1, valid RT
 * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
 * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
 * values are inverted: lower p->prio value means higher priority.
 *
 * The MAX_USER_RT_PRIO value allows the actual maximum
 * RT priority to be separate from the value exported to
 * user-space.  This allows kernel threads to set their
 * priority to a value higher than any user task. Note:
 * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
 */

#define MAX_USER_RT_PRIO	100
#define MAX_RT_PRIO		MAX_USER_RT_PRIO

#define MAX_PRIO		(MAX_RT_PRIO + NICE_WIDTH)
#define DEFAULT_PRIO		(MAX_RT_PRIO + NICE_WIDTH / 2)

/*
 * Convert user-nice values [ -20 ... 0 ... 19 ]
 * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
 * and back.
 */
#define NICE_TO_PRIO(nice)	((nice) + DEFAULT_PRIO)
#define PRIO_TO_NICE(prio)	((prio) - DEFAULT_PRIO)

/*
 * 'User priority' is the nice value converted to something we
 * can work with better when scaling various scheduler parameters,
 * it's a [ 0 ... 39 ] range.
 */
#define USER_PRIO(p)		((p)-MAX_RT_PRIO)
#define TASK_USER_PRIO(p)	USER_PRIO((p)->static_prio)
#define MAX_USER_PRIO		(USER_PRIO(MAX_PRIO))

/*
 * Convert nice value [19,-20] to rlimit style value [1,40].
 */
static inline long nice_to_rlimit(long nice)
{
	return (MAX_NICE - nice + 1);
}

/*
 * Convert rlimit style value [1,40] to nice value [-20, 19].
 */
static inline long rlimit_to_nice(long prio)
{
	return (MAX_NICE - prio + 1);
}

#endif /* _SCHED_PRIO_H */
Commit	Line	Data
5c228079 DY	1	#ifndef _SCHED_PRIO_H
	2	#define _SCHED_PRIO_H
	3
3ee237dd DY	4	#define MAX_NICE 19
	5	#define MIN_NICE -20
	6	#define NICE_WIDTH (MAX_NICE - MIN_NICE + 1)
	7
5c228079 DY	8	/*
	9	* Priority of a process goes from 0..MAX_PRIO-1, valid RT
	10	* priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
	11	* tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
	12	* values are inverted: lower p->prio value means higher priority.
	13	*
	14	* The MAX_USER_RT_PRIO value allows the actual maximum
	15	* RT priority to be separate from the value exported to
	16	* user-space. This allows kernel threads to set their
	17	* priority to a value higher than any user task. Note:
	18	* MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
	19	*/
	20
	21	#define MAX_USER_RT_PRIO 100
	22	#define MAX_RT_PRIO MAX_USER_RT_PRIO
	23
3ee237dd DY	24	#define MAX_PRIO (MAX_RT_PRIO + NICE_WIDTH)
3ee237dd DY	25	#define DEFAULT_PRIO (MAX_RT_PRIO + NICE_WIDTH / 2)
5c228079	26
6b6350f1 DY	27	/*
	28	* Convert user-nice values [ -20 ... 0 ... 19 ]
	29	* to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
	30	* and back.
	31	*/
7e298d60 DY	32	#define NICE_TO_PRIO(nice) ((nice) + DEFAULT_PRIO)
7e298d60 DY	33	#define PRIO_TO_NICE(prio) ((prio) - DEFAULT_PRIO)
6b6350f1 DY	34
	35	/*
	36	* 'User priority' is the nice value converted to something we
	37	* can work with better when scaling various scheduler parameters,
	38	* it's a [ 0 ... 39 ] range.
	39	*/
	40	#define USER_PRIO(p) ((p)-MAX_RT_PRIO)
	41	#define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio)
	42	#define MAX_USER_PRIO (USER_PRIO(MAX_PRIO))
	43
7aa2c016 DY	44	/*
	45	* Convert nice value [19,-20] to rlimit style value [1,40].
	46	*/
	47	static inline long nice_to_rlimit(long nice)
	48	{
	49	return (MAX_NICE - nice + 1);
	50	}
	51
	52	/*
	53	* Convert rlimit style value [1,40] to nice value [-20, 19].
	54	*/
	55	static inline long rlimit_to_nice(long prio)
	56	{
	57	return (MAX_NICE - prio + 1);
	58	}
	59
5c228079	60	#endif /* _SCHED_PRIO_H */