Line data    Source code

       1             : /* SPDX-License-Identifier: GPL-2.0 */
       2             : #ifndef _LINUX_SCHED_PRIO_H
       3             : #define _LINUX_SCHED_PRIO_H
       4             : 
       5             : #define MAX_NICE        19
       6             : #define MIN_NICE        -20
       7             : #define NICE_WIDTH      (MAX_NICE - MIN_NICE + 1)
       8             : 
       9             : /*
      10             :  * Priority of a process goes from 0..MAX_PRIO-1, valid RT
      11             :  * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
      12             :  * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
      13             :  * values are inverted: lower p->prio value means higher priority.
      14             :  */
      15             : 
      16             : #define MAX_RT_PRIO             100
      17             : 
      18             : #define MAX_PRIO                (MAX_RT_PRIO + NICE_WIDTH)
      19             : #define DEFAULT_PRIO            (MAX_RT_PRIO + NICE_WIDTH / 2)
      20             : 
      21             : /*
      22             :  * Convert user-nice values [ -20 ... 0 ... 19 ]
      23             :  * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
      24             :  * and back.
      25             :  */
      26             : #define NICE_TO_PRIO(nice)      ((nice) + DEFAULT_PRIO)
      27             : #define PRIO_TO_NICE(prio)      ((prio) - DEFAULT_PRIO)
      28             : 
      29             : /*
      30             :  * Convert nice value [19,-20] to rlimit style value [1,40].
      31             :  */
      32             : static inline long nice_to_rlimit(long nice)
      33             : {
      34           0 :         return (MAX_NICE - nice + 1);
      35             : }
      36             : 
      37             : /*
      38             :  * Convert rlimit style value [1,40] to nice value [-20, 19].
      39             :  */
      40             : static inline long rlimit_to_nice(long prio)
      41             : {
      42             :         return (MAX_NICE - prio + 1);
      43             : }
      44             : 
      45             : #endif /* _LINUX_SCHED_PRIO_H */