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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_SCHED_PRIO_H
#define _LINUX_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 /* _LINUX_SCHED_PRIO_H */