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 #define MAX_DL_PRIO 0 18 19 #define MAX_PRIO (MAX_RT_PRIO + NICE_WIDTH) 20 #define DEFAULT_PRIO (MAX_RT_PRIO + NICE_WIDTH / 2) 21 22 /* 23 * Convert user-nice values [ -20 ... 0 ... 19 ] 24 * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], 25 * and back. 26 */ 27 #define NICE_TO_PRIO(nice) ((nice) + DEFAULT_PRIO) 28 #define PRIO_TO_NICE(prio) ((prio) - DEFAULT_PRIO) 29 30 /* 31 * Convert nice value [19,-20] to rlimit style value [1,40]. 32 */ 33 static inline long nice_to_rlimit(long nice) 34 { 35 return (MAX_NICE - nice + 1); 36 } 37 38 /* 39 * Convert rlimit style value [1,40] to nice value [-20, 19]. 40 */ 41 static inline long rlimit_to_nice(long prio) 42 { 43 return (MAX_NICE - prio + 1); 44 } 45 46 #endif /* _LINUX_SCHED_PRIO_H */ 47