xref: /netbsd-src/lib/libc/sys/sched.c (revision c5b83981a9e5eb83a85512e7d3a7f3804f96e6d8)
1 /*	$NetBSD: sched.c,v 1.6 2018/01/04 20:57:29 kamil Exp $	*/
2 
3 /*
4  * Copyright (c) 2008, Mindaugas Rasiukevicius <rmind at NetBSD org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __RCSID("$NetBSD: sched.c,v 1.6 2018/01/04 20:57:29 kamil Exp $");
31 
32 #include "namespace.h"
33 #include <string.h>
34 #include <unistd.h>
35 #include <errno.h>
36 #include <sched.h>
37 #include <signal.h>
38 #include <sys/param.h>
39 #include <sys/types.h>
40 
41 /* All LWPs in the process */
42 #define	P_ALL_LWPS		0
43 
44 /*
45  * Scheduling parameters.
46  */
47 
48 int
sched_setparam(pid_t pid,const struct sched_param * param)49 sched_setparam(pid_t pid, const struct sched_param *param)
50 {
51 	struct sched_param sp;
52 
53 	memset(&sp, 0, sizeof(struct sched_param));
54 	sp.sched_priority = param->sched_priority;
55 	return _sched_setparam(pid, P_ALL_LWPS, SCHED_NONE, &sp);
56 }
57 
58 int
sched_getparam(pid_t pid,struct sched_param * param)59 sched_getparam(pid_t pid, struct sched_param *param)
60 {
61 
62 	return _sched_getparam(pid, P_ALL_LWPS, NULL, param);
63 }
64 
65 int
sched_setscheduler(pid_t pid,int policy,const struct sched_param * param)66 sched_setscheduler(pid_t pid, int policy, const struct sched_param *param)
67 {
68 	struct sched_param sp;
69 	int ret, old_policy;
70 
71 	ret = _sched_getparam(pid, P_ALL_LWPS, &old_policy, &sp);
72 	if (ret < 0)
73 		return ret;
74 
75 	memset(&sp, 0, sizeof(struct sched_param));
76 	sp.sched_priority = param->sched_priority;
77 	ret = _sched_setparam(pid, P_ALL_LWPS, policy, &sp);
78 	if (ret < 0)
79 		return ret;
80 
81 	return old_policy;
82 }
83 
84 int
sched_getscheduler(pid_t pid)85 sched_getscheduler(pid_t pid)
86 {
87 	struct sched_param sp;
88 	int ret, policy;
89 
90 	ret = _sched_getparam(pid, P_ALL_LWPS, &policy, &sp);
91 	if (ret < 0)
92 		return ret;
93 
94 	return policy;
95 }
96 
97 /*
98  * Scheduling priorities.
99  */
100 
101 int
sched_get_priority_max(int policy)102 sched_get_priority_max(int policy)
103 {
104 
105 	switch (policy) {
106 	case SCHED_OTHER:
107 		return PRI_NONE;
108 	case SCHED_RR:
109 	case SCHED_FIFO:
110 		return (int)sysconf(_SC_SCHED_PRI_MAX);
111 	default:
112 		errno = EINVAL;
113 		return -1;
114 	}
115 }
116 
117 int
sched_get_priority_min(int policy)118 sched_get_priority_min(int policy)
119 {
120 
121 	switch (policy) {
122 	case SCHED_OTHER:
123 		return PRI_NONE;
124 	case SCHED_RR:
125 	case SCHED_FIFO:
126 		return (int)sysconf(_SC_SCHED_PRI_MIN);
127 	default:
128 		errno = EINVAL;
129 		return -1;
130 	}
131 }
132 
133 int
134 /*ARGSUSED*/
sched_rr_get_interval(pid_t pid,struct timespec * interval)135 sched_rr_get_interval(pid_t pid, struct timespec *interval)
136 {
137 
138 	if (pid && kill(pid, 0) == -1)
139 		return -1;
140 	interval->tv_sec = 0;
141 	interval->tv_nsec = sysconf(_SC_SCHED_RT_TS) * 1000;
142 	return 0;
143 }
144 
145 /*
146  * Process affinity.
147  */
148 
149 int
sched_getaffinity_np(pid_t pid,size_t size,cpuset_t * cpuset)150 sched_getaffinity_np(pid_t pid, size_t size, cpuset_t *cpuset)
151 {
152 
153 	return _sched_getaffinity(pid, P_ALL_LWPS, size, cpuset);
154 }
155 
156 int
sched_setaffinity_np(pid_t pid,size_t size,cpuset_t * cpuset)157 sched_setaffinity_np(pid_t pid, size_t size, cpuset_t *cpuset)
158 {
159 
160 	return _sched_setaffinity(pid, P_ALL_LWPS, size, cpuset);
161 }
162