diff options
Diffstat (limited to 'include/linux/sched/prio.h')
| -rw-r--r-- | include/linux/sched/prio.h | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/include/linux/sched/prio.h b/include/linux/sched/prio.h new file mode 100644 index 000000000000..ac322583c820 --- /dev/null +++ b/include/linux/sched/prio.h @@ -0,0 +1,44 @@ +#ifndef _SCHED_PRIO_H +#define _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)) + +#endif /* _SCHED_PRIO_H */ |