xref: /linux/include/linux/sched/deadline.h (revision 0913b580f8490caaaf08dd1591e0bc07ac2720cb)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_SCHED_DEADLINE_H
3 #define _LINUX_SCHED_DEADLINE_H
4 
5 /*
6  * SCHED_DEADLINE tasks has negative priorities, reflecting
7  * the fact that any of them has higher prio than RT and
8  * NORMAL/BATCH tasks.
9  */
10 
11 #include <linux/sched.h>
12 
dl_prio(int prio)13 static inline bool dl_prio(int prio)
14 {
15 	return unlikely(prio < MAX_DL_PRIO);
16 }
17 
18 /*
19  * Returns true if a task has a priority that belongs to DL class. PI-boosted
20  * tasks will return true. Use dl_policy() to ignore PI-boosted tasks.
21  */
dl_task(struct task_struct * p)22 static inline bool dl_task(struct task_struct *p)
23 {
24 	return dl_prio(p->prio);
25 }
26 
dl_time_before(u64 a,u64 b)27 static inline bool dl_time_before(u64 a, u64 b)
28 {
29 	return (s64)(a - b) < 0;
30 }
31 
32 struct root_domain;
33 extern void dl_add_task_root_domain(struct task_struct *p);
34 extern void dl_clear_root_domain(struct root_domain *rd);
35 extern void dl_clear_root_domain_cpu(int cpu);
36 /*
37  * Return whether moving DL task @p to @new_mask requires moving DL
38  * bandwidth accounting between root domains. This helper is specific to
39  * DL bandwidth move accounting semantics and is shared by
40  * cpuset_can_attach() and set_cpus_allowed_dl() so both paths use the
41  * same source root-domain test.
42  */
43 extern bool dl_task_needs_bw_move(struct task_struct *p,
44 				  const struct cpumask *new_mask);
45 
46 extern u64 dl_cookie;
47 extern bool dl_bw_visited(int cpu, u64 cookie);
48 
dl_server(struct sched_dl_entity * dl_se)49 static inline bool dl_server(struct sched_dl_entity *dl_se)
50 {
51 	return dl_se->dl_server;
52 }
53 
dl_task_of(struct sched_dl_entity * dl_se)54 static inline struct task_struct *dl_task_of(struct sched_dl_entity *dl_se)
55 {
56 	BUG_ON(dl_server(dl_se));
57 	return container_of(dl_se, struct task_struct, dl);
58 }
59 
60 /*
61  * Regarding the deadline, a task with implicit deadline has a relative
62  * deadline == relative period. A task with constrained deadline has a
63  * relative deadline <= relative period.
64  *
65  * We support constrained deadline tasks. However, there are some restrictions
66  * applied only for tasks which do not have an implicit deadline. See
67  * update_dl_entity() to know more about such restrictions.
68  *
69  * The dl_is_implicit() returns true if the task has an implicit deadline.
70  */
dl_is_implicit(struct sched_dl_entity * dl_se)71 static inline bool dl_is_implicit(struct sched_dl_entity *dl_se)
72 {
73 	return dl_se->dl_deadline == dl_se->dl_period;
74 }
75 
76 #endif /* _LINUX_SCHED_DEADLINE_H */
77