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 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 */ 46