xref: /netbsd-src/usr.sbin/schedctl/schedctl.c (revision 8ac07aec990b9d2e483062509d0a9fa5b4f57cf2)
1 /*	$NetBSD: schedctl.c,v 1.5 2008/03/24 10:33:17 xtraeme 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 COPYRIGHT HOLDERS AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * schedctl(8) - a program to control scheduling of processes and threads.
31  */
32 
33 #include <sys/cdefs.h>
34 
35 #ifndef lint
36 __RCSID("$NetBSD: schedctl.c,v 1.5 2008/03/24 10:33:17 xtraeme Exp $");
37 #endif
38 
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 
43 #include <err.h>
44 #include <fcntl.h>
45 #include <kvm.h>
46 #include <unistd.h>
47 
48 #include <sys/pset.h>
49 #include <sys/sched.h>
50 #include <sys/sysctl.h>
51 #include <sys/types.h>
52 
53 static const char *class_str[] = {
54 	"SCHED_OTHER",
55 	"SCHED_FIFO",
56 	"SCHED_RR"
57 };
58 
59 static void	sched_set(pid_t, lwpid_t, int, struct sched_param *, cpuset_t *);
60 static void	thread_info(pid_t, lwpid_t);
61 static cpuset_t	*makecpuset(char *);
62 static char	*showcpuset(cpuset_t *);
63 static void	usage(void);
64 
65 static u_int	ncpu;
66 
67 int
68 main(int argc, char **argv)
69 {
70 	kvm_t *kd;
71 	struct kinfo_lwp *lwp_list, *lwp;
72 	struct sched_param *sp;
73 	cpuset_t *cpuset;
74 	int i, count, ch, policy;
75 	pid_t pid;
76 	lwpid_t lid;
77 	bool set;
78 
79 	ncpu = sysconf(_SC_NPROCESSORS_CONF);
80 
81 	pid = lid = 0;
82 	cpuset = NULL;
83 	set = false;
84 
85 	sp = calloc(1, sizeof(struct sched_param));
86 	if (sp == NULL)
87 		err(EXIT_FAILURE, "calloc");
88 
89 	sp->sched_priority = PRI_NONE;
90 	policy = SCHED_NONE;
91 
92 	while ((ch = getopt(argc, argv, "A:C:P:p:t:")) != -1) {
93 		switch (ch) {
94 		case 'p':
95 			/* PID */
96 			pid = atoi(optarg);
97 			break;
98 		case 't':
99 			/* Thread (LWP) ID */
100 			lid = atoi(optarg);
101 			break;
102 		case 'A':
103 			/* Affinity */
104 			cpuset = makecpuset(optarg);
105 			if (cpuset == NULL) {
106 				fprintf(stderr, "%s: invalid CPU value\n",
107 				    getprogname());
108 				exit(EXIT_FAILURE);
109 			}
110 			break;
111 		case 'C':
112 			/* Scheduling class */
113 			policy = atoi(optarg);
114 			if (policy < SCHED_OTHER || policy > SCHED_RR) {
115 				fprintf(stderr,
116 				    "%s: invalid scheduling class\n",
117 				    getprogname());
118 				exit(EXIT_FAILURE);
119 			}
120 			set = true;
121 			break;
122 		case 'P':
123 			/* Priority */
124 			sp->sched_priority = atoi(optarg);
125 			if (sp->sched_priority < sysconf(_SC_SCHED_PRI_MIN) ||
126 			    sp->sched_priority > sysconf(_SC_SCHED_PRI_MAX)) {
127 				fprintf(stderr, "%s: invalid priority\n",
128 				    getprogname());
129 				exit(EXIT_FAILURE);
130 			}
131 			set = true;
132 			break;
133 		default:
134 			usage();
135 		}
136 	}
137 
138 	/* At least PID must be specified */
139 	if (pid == 0)
140 		usage();
141 
142 	/* Set the scheduling information for thread/process */
143 	sched_set(pid, lid, policy, set ? sp : NULL, cpuset);
144 
145 	/* Show information about each thread */
146 	kd = kvm_open(NULL, NULL, NULL, KVM_NO_FILES, "kvm_open");
147 	if (kd == NULL)
148 		err(EXIT_FAILURE, "kvm_open");
149 	lwp_list = kvm_getlwps(kd, pid, 0, sizeof(struct kinfo_lwp), &count);
150 	if (lwp_list == NULL)
151 		err(EXIT_FAILURE, "kvm_getlwps");
152 	for (lwp = lwp_list, i = 0; i < count; lwp++, i++) {
153 		if (lid && lid != lwp->l_lid)
154 			continue;
155 		thread_info(pid, lwp->l_lid);
156 	}
157 	kvm_close(kd);
158 
159 	free(sp);
160 	free(cpuset);
161 	return 0;
162 }
163 
164 static void
165 sched_set(pid_t pid, lwpid_t lid, int policy,
166     struct sched_param *sp, cpuset_t *cpuset)
167 {
168 	int error;
169 
170 	if (sp) {
171 		/* Set the scheduling parameters for the thread */
172 		error = _sched_setparam(pid, lid, policy, sp);
173 		if (error < 0)
174 			err(EXIT_FAILURE, "_sched_setparam");
175 	}
176 	if (cpuset) {
177 		/* Set the CPU-set for affinity */
178 		error = _sched_setaffinity(pid, lid,
179 		    sizeof(cpuset_t), cpuset);
180 		if (error < 0)
181 			err(EXIT_FAILURE, "_sched_setaffinity");
182 	}
183 }
184 
185 static void
186 thread_info(pid_t pid, lwpid_t lid)
187 {
188 	struct sched_param sp;
189 	cpuset_t *cpuset;
190 	char *cpus;
191 	int error, policy;
192 
193 	cpuset = malloc(sizeof(cpuset_t));
194 	if (cpuset == NULL)
195 		err(EXIT_FAILURE, "malloc");
196 
197 	error = _sched_getparam(pid, lid, &policy, &sp);
198 	if (error < 0)
199 		err(EXIT_FAILURE, "_sched_getparam");
200 
201 	error = _sched_getaffinity(pid, lid, sizeof(cpuset_t), cpuset);
202 	if (error < 0)
203 		err(EXIT_FAILURE, "_sched_getaffinity");
204 
205 	printf("  LID:              %d\n", lid);
206 	printf("  Priority:         %d\n", sp.sched_priority);
207 	printf("  Class:            %s\n", class_str[policy]);
208 
209 	cpus = showcpuset(cpuset);
210 	printf("  Affinity (CPUs):  %s\n", cpus);
211 	free(cpus);
212 
213 	free(cpuset);
214 }
215 
216 static cpuset_t *
217 makecpuset(char *str)
218 {
219 	cpuset_t *cpuset;
220 	char *cpustr, *s;
221 
222 	if (str == NULL)
223 		return NULL;
224 
225 	cpuset = calloc(1, sizeof(cpuset_t));
226 	if (cpuset == NULL)
227 		err(EXIT_FAILURE, "malloc");
228 
229 	cpustr = strdup(str);
230 	if (cpustr == NULL)
231 		err(EXIT_FAILURE, "strdup");
232 	s = cpustr;
233 
234 	while (s != NULL) {
235 		char *p;
236 		int i;
237 
238 		/* Get the CPU number and validate the range */
239 		p = strsep(&s, ",");
240 		if (p == NULL) {
241 			free(cpuset);
242 			cpuset = NULL;
243 			break;
244 		}
245 		i = atoi(p);
246 		if (i == -1) {
247 			memset(cpuset, 0, sizeof(cpuset_t));
248 			break;
249 		}
250 		if ((unsigned int)i >= ncpu) {
251 			free(cpuset);
252 			cpuset = NULL;
253 			break;
254 		}
255 
256 		/* Set the bit */
257 		CPU_SET(i, cpuset);
258 	}
259 
260 	free(cpustr);
261 	return cpuset;
262 }
263 
264 static char *
265 showcpuset(cpuset_t *cpuset)
266 {
267 	char *buf;
268 	size_t size;
269 	int i;
270 
271 	size = 3 * ncpu;	/* XXX */
272 	buf = malloc(size + 1);
273 	if (buf == NULL)
274 		err(EXIT_FAILURE, "malloc");
275 	memset(buf, '\0', size + 1);
276 
277 	for (i = 0; i < ncpu; i++)
278 		if (CPU_ISSET(i, cpuset))
279 			snprintf(buf, size, "%s%d,", buf, i);
280 
281 	i = strlen(buf);
282 	if (i != 0) {
283 		buf[i - 1] = '\0';
284 	} else {
285 		strncpy(buf, "<none>", size);
286 	}
287 
288 	return buf;
289 }
290 
291 static void
292 usage(void)
293 {
294 	fprintf(stderr, "usage: %s -p pid [-t lid] [-A processor] "
295 	    "[-C class] [-P priority]\n", getprogname());
296 	exit(EXIT_FAILURE);
297 }
298