xref: /linux-6.15/include/linux/sched/rt.h (revision a5f6ea29)
1 #ifndef _SCHED_RT_H
2 #define _SCHED_RT_H
3 
4 /*
5  * Priority of a process goes from 0..MAX_PRIO-1, valid RT
6  * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
7  * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
8  * values are inverted: lower p->prio value means higher priority.
9  *
10  * The MAX_USER_RT_PRIO value allows the actual maximum
11  * RT priority to be separate from the value exported to
12  * user-space.  This allows kernel threads to set their
13  * priority to a value higher than any user task. Note:
14  * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
15  */
16 
17 #define MAX_USER_RT_PRIO	100
18 #define MAX_RT_PRIO		MAX_USER_RT_PRIO
19 
20 #define MAX_PRIO		(MAX_RT_PRIO + 40)
21 #define DEFAULT_PRIO		(MAX_RT_PRIO + 20)
22 
23 static inline int rt_prio(int prio)
24 {
25 	if (unlikely(prio < MAX_RT_PRIO))
26 		return 1;
27 	return 0;
28 }
29 
30 static inline int rt_task(struct task_struct *p)
31 {
32 	return rt_prio(p->prio);
33 }
34 
35 #ifdef CONFIG_RT_MUTEXES
36 extern int rt_mutex_getprio(struct task_struct *p);
37 extern void rt_mutex_setprio(struct task_struct *p, int prio);
38 extern struct task_struct *rt_mutex_get_top_task(struct task_struct *task);
39 extern void rt_mutex_adjust_pi(struct task_struct *p);
40 static inline bool tsk_is_pi_blocked(struct task_struct *tsk)
41 {
42 	return tsk->pi_blocked_on != NULL;
43 }
44 #else
45 static inline int rt_mutex_getprio(struct task_struct *p)
46 {
47 	return p->normal_prio;
48 }
49 static inline struct task_struct *rt_mutex_get_top_task(struct task_struct *task)
50 {
51 	return NULL;
52 }
53 # define rt_mutex_adjust_pi(p)		do { } while (0)
54 static inline bool tsk_is_pi_blocked(struct task_struct *tsk)
55 {
56 	return false;
57 }
58 #endif
59 
60 extern void normalize_rt_tasks(void);
61 
62 
63 /*
64  * default timeslice is 100 msecs (used only for SCHED_RR tasks).
65  * Timeslices get refilled after they expire.
66  */
67 #define RR_TIMESLICE		(100 * HZ / 1000)
68 
69 #endif /* _SCHED_RT_H */
70