1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */ 2*4882a593Smuzhiyun #ifndef _LINUX_SCHED_PRIO_H 3*4882a593Smuzhiyun #define _LINUX_SCHED_PRIO_H 4*4882a593Smuzhiyun 5*4882a593Smuzhiyun #define MAX_NICE 19 6*4882a593Smuzhiyun #define MIN_NICE -20 7*4882a593Smuzhiyun #define NICE_WIDTH (MAX_NICE - MIN_NICE + 1) 8*4882a593Smuzhiyun 9*4882a593Smuzhiyun /* 10*4882a593Smuzhiyun * Priority of a process goes from 0..MAX_PRIO-1, valid RT 11*4882a593Smuzhiyun * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH 12*4882a593Smuzhiyun * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority 13*4882a593Smuzhiyun * values are inverted: lower p->prio value means higher priority. 14*4882a593Smuzhiyun * 15*4882a593Smuzhiyun * The MAX_USER_RT_PRIO value allows the actual maximum 16*4882a593Smuzhiyun * RT priority to be separate from the value exported to 17*4882a593Smuzhiyun * user-space. This allows kernel threads to set their 18*4882a593Smuzhiyun * priority to a value higher than any user task. Note: 19*4882a593Smuzhiyun * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO. 20*4882a593Smuzhiyun */ 21*4882a593Smuzhiyun 22*4882a593Smuzhiyun #define MAX_USER_RT_PRIO 100 23*4882a593Smuzhiyun #define MAX_RT_PRIO MAX_USER_RT_PRIO 24*4882a593Smuzhiyun 25*4882a593Smuzhiyun #define MAX_PRIO (MAX_RT_PRIO + NICE_WIDTH) 26*4882a593Smuzhiyun #define DEFAULT_PRIO (MAX_RT_PRIO + NICE_WIDTH / 2) 27*4882a593Smuzhiyun 28*4882a593Smuzhiyun /* 29*4882a593Smuzhiyun * Convert user-nice values [ -20 ... 0 ... 19 ] 30*4882a593Smuzhiyun * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], 31*4882a593Smuzhiyun * and back. 32*4882a593Smuzhiyun */ 33*4882a593Smuzhiyun #define NICE_TO_PRIO(nice) ((nice) + DEFAULT_PRIO) 34*4882a593Smuzhiyun #define PRIO_TO_NICE(prio) ((prio) - DEFAULT_PRIO) 35*4882a593Smuzhiyun 36*4882a593Smuzhiyun /* 37*4882a593Smuzhiyun * 'User priority' is the nice value converted to something we 38*4882a593Smuzhiyun * can work with better when scaling various scheduler parameters, 39*4882a593Smuzhiyun * it's a [ 0 ... 39 ] range. 40*4882a593Smuzhiyun */ 41*4882a593Smuzhiyun #define USER_PRIO(p) ((p)-MAX_RT_PRIO) 42*4882a593Smuzhiyun #define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio) 43*4882a593Smuzhiyun #define MAX_USER_PRIO (USER_PRIO(MAX_PRIO)) 44*4882a593Smuzhiyun 45*4882a593Smuzhiyun /* 46*4882a593Smuzhiyun * Convert nice value [19,-20] to rlimit style value [1,40]. 47*4882a593Smuzhiyun */ nice_to_rlimit(long nice)48*4882a593Smuzhiyunstatic inline long nice_to_rlimit(long nice) 49*4882a593Smuzhiyun { 50*4882a593Smuzhiyun return (MAX_NICE - nice + 1); 51*4882a593Smuzhiyun } 52*4882a593Smuzhiyun 53*4882a593Smuzhiyun /* 54*4882a593Smuzhiyun * Convert rlimit style value [1,40] to nice value [-20, 19]. 55*4882a593Smuzhiyun */ rlimit_to_nice(long prio)56*4882a593Smuzhiyunstatic inline long rlimit_to_nice(long prio) 57*4882a593Smuzhiyun { 58*4882a593Smuzhiyun return (MAX_NICE - prio + 1); 59*4882a593Smuzhiyun } 60*4882a593Smuzhiyun 61*4882a593Smuzhiyun #endif /* _LINUX_SCHED_PRIO_H */ 62