xref: /freebsd/usr.sbin/powerd/powerd.c (revision 22cf89c938886d14f5796fc49f9f020c23ea8eaf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2004 Colin Percival
5  * Copyright (c) 2005 Nate Lawson
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted providing that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
25  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
26  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  * POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 #include <sys/param.h>
32 #include <sys/ioctl.h>
33 #include <sys/sysctl.h>
34 #include <sys/resource.h>
35 #include <sys/socket.h>
36 #include <sys/time.h>
37 #include <sys/un.h>
38 
39 #include <err.h>
40 #include <errno.h>
41 #include <fcntl.h>
42 #include <libutil.h>
43 #include <signal.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <sysexits.h>
48 #include <unistd.h>
49 
50 #ifdef __i386__
51 #define USE_APM
52 #endif
53 
54 #ifdef USE_APM
55 #include <machine/apm_bios.h>
56 #endif
57 
58 #define DEFAULT_ACTIVE_PERCENT	75
59 #define DEFAULT_IDLE_PERCENT	50
60 #define DEFAULT_POLL_INTERVAL	250	/* Poll interval in milliseconds */
61 
62 typedef enum {
63 	MODE_MIN,
64 	MODE_ADAPTIVE,
65 	MODE_HIADAPTIVE,
66 	MODE_MAX,
67 } modes_t;
68 
69 typedef enum {
70 	SRC_AC,
71 	SRC_BATTERY,
72 	SRC_UNKNOWN,
73 } power_src_t;
74 
75 static const char *modes[] = {
76 	"AC",
77 	"battery",
78 	"unknown"
79 };
80 
81 #define ACPIAC		"hw.acpi.acline"
82 #define PMUAC		"dev.pmu.0.acline"
83 #define APMDEV		"/dev/apm"
84 #define DEVDPIPE	"/var/run/devd.pipe"
85 #define DEVCTL_MAXBUF	1024
86 
87 static int	read_usage_times(int *load, int nonice);
88 static int	read_freqs(int *numfreqs, int **freqs, int **power,
89 		    int minfreq, int maxfreq);
90 static int	set_freq(int freq);
91 static void	acline_init(void);
92 static void	acline_read(void);
93 static int	devd_init(void);
94 static void	devd_close(void);
95 static void	handle_sigs(int sig);
96 static void	parse_mode(char *arg, int *mode, int ch);
97 static void	usage(void);
98 
99 /* Sysctl data structures. */
100 static int	cp_times_mib[2];
101 static int	freq_mib[4];
102 static int	levels_mib[4];
103 static int	acline_mib[4];
104 static size_t	acline_mib_len;
105 
106 /* Configuration */
107 static int	cpu_running_mark;
108 static int	cpu_idle_mark;
109 static int	poll_ival;
110 static int	vflag;
111 
112 static volatile sig_atomic_t exit_requested;
113 static power_src_t acline_status;
114 typedef enum {
115 	ac_none,
116 	ac_sysctl,
117 	ac_acpi_devd,
118 #ifdef USE_APM
119 	ac_apm,
120 #endif
121 } acline_mode_t;
122 static acline_mode_t acline_mode;
123 static acline_mode_t acline_mode_user = ac_none;
124 #ifdef USE_APM
125 static int	apm_fd = -1;
126 #endif
127 static int	devd_pipe = -1;
128 
129 #define DEVD_RETRY_INTERVAL 60 /* seconds */
130 static struct timeval tried_devd;
131 
132 /*
133  * This function returns summary load of all CPUs.  It was made so
134  * intentionally to not reduce performance in scenarios when several
135  * threads are processing requests as a pipeline -- running one at
136  * a time on different CPUs and waiting for each other.  If nonice
137  * is nonzero, only user+sys+intr time will be counted as load; any
138  * nice time will be treated as if idle.
139  */
140 static int
141 read_usage_times(int *load, int nonice)
142 {
143 	static long *cp_times = NULL, *cp_times_old = NULL;
144 	static int ncpus = 0;
145 	size_t cp_times_len;
146 	int error, cpu, i, total, excl;
147 
148 	if (cp_times == NULL) {
149 		cp_times_len = 0;
150 		error = sysctl(cp_times_mib, 2, NULL, &cp_times_len, NULL, 0);
151 		if (error)
152 			return (error);
153 		if ((cp_times = malloc(cp_times_len)) == NULL)
154 			return (errno);
155 		if ((cp_times_old = malloc(cp_times_len)) == NULL) {
156 			free(cp_times);
157 			cp_times = NULL;
158 			return (errno);
159 		}
160 		ncpus = cp_times_len / (sizeof(long) * CPUSTATES);
161 	}
162 
163 	cp_times_len = sizeof(long) * CPUSTATES * ncpus;
164 	error = sysctl(cp_times_mib, 2, cp_times, &cp_times_len, NULL, 0);
165 	if (error)
166 		return (error);
167 
168 	if (load) {
169 		*load = 0;
170 		for (cpu = 0; cpu < ncpus; cpu++) {
171 			total = 0;
172 			for (i = 0; i < CPUSTATES; i++) {
173 			    total += cp_times[cpu * CPUSTATES + i] -
174 				cp_times_old[cpu * CPUSTATES + i];
175 			}
176 			if (total == 0)
177 				continue;
178 			excl = cp_times[cpu * CPUSTATES + CP_IDLE] -
179 			    cp_times_old[cpu * CPUSTATES + CP_IDLE];
180 			if (nonice)
181 				excl += cp_times[cpu * CPUSTATES + CP_NICE] -
182 				    cp_times_old[cpu * CPUSTATES + CP_NICE];
183 			*load += 100 - excl * 100 / total;
184 		}
185 	}
186 
187 	memcpy(cp_times_old, cp_times, cp_times_len);
188 
189 	return (0);
190 }
191 
192 static int
193 read_freqs(int *numfreqs, int **freqs, int **power, int minfreq, int maxfreq)
194 {
195 	char *freqstr, *p, *q;
196 	int i, j;
197 	size_t len = 0;
198 
199 	if (sysctl(levels_mib, 4, NULL, &len, NULL, 0))
200 		return (-1);
201 	if ((freqstr = malloc(len)) == NULL)
202 		return (-1);
203 	if (sysctl(levels_mib, 4, freqstr, &len, NULL, 0)) {
204 		free(freqstr);
205 		return (-1);
206 	}
207 
208 	*numfreqs = 1;
209 	for (p = freqstr; *p != '\0'; p++)
210 		if (*p == ' ')
211 			(*numfreqs)++;
212 
213 	if ((*freqs = malloc(*numfreqs * sizeof(int))) == NULL) {
214 		free(freqstr);
215 		return (-1);
216 	}
217 	if ((*power = malloc(*numfreqs * sizeof(int))) == NULL) {
218 		free(freqstr);
219 		free(*freqs);
220 		return (-1);
221 	}
222 	for (i = 0, j = 0, p = freqstr; i < *numfreqs; i++) {
223 		q = strchr(p, ' ');
224 		if (q != NULL)
225 			*q = '\0';
226 		if (sscanf(p, "%d/%d", &(*freqs)[j], &(*power)[i]) != 2) {
227 			free(freqstr);
228 			free(*freqs);
229 			free(*power);
230 			return (-1);
231 		}
232 		if (((*freqs)[j] >= minfreq || minfreq == -1) &&
233 		    ((*freqs)[j] <= maxfreq || maxfreq == -1))
234 			j++;
235 		p = q + 1;
236 	}
237 
238 	*numfreqs = j;
239 	if ((*freqs = realloc(*freqs, *numfreqs * sizeof(int))) == NULL) {
240 		free(freqstr);
241 		free(*freqs);
242 		free(*power);
243 		return (-1);
244 	}
245 
246 	free(freqstr);
247 	return (0);
248 }
249 
250 static int
251 get_freq(void)
252 {
253 	size_t len;
254 	int curfreq;
255 
256 	len = sizeof(curfreq);
257 	if (sysctl(freq_mib, 4, &curfreq, &len, NULL, 0) != 0) {
258 		if (vflag)
259 			warn("error reading current CPU frequency");
260 		curfreq = 0;
261 	}
262 	return (curfreq);
263 }
264 
265 static int
266 set_freq(int freq)
267 {
268 
269 	if (sysctl(freq_mib, 4, NULL, NULL, &freq, sizeof(freq))) {
270 		if (errno != EPERM)
271 			return (-1);
272 	}
273 
274 	return (0);
275 }
276 
277 static int
278 get_freq_id(int freq, int *freqs, int numfreqs)
279 {
280 	int i = 1;
281 
282 	while (i < numfreqs) {
283 		if (freqs[i] < freq)
284 			break;
285 		i++;
286 	}
287 	return (i - 1);
288 }
289 
290 /*
291  * Try to use ACPI to find the AC line status.  If this fails, fall back
292  * to APM.  If nothing succeeds, we'll just run in default mode.
293  */
294 static void
295 acline_init(void)
296 {
297 	int skip_source_check;
298 
299 	acline_mib_len = 4;
300 	acline_status = SRC_UNKNOWN;
301 	skip_source_check = (acline_mode_user == ac_none ||
302 			     acline_mode_user == ac_acpi_devd);
303 
304 	if ((skip_source_check || acline_mode_user == ac_sysctl) &&
305 	    sysctlnametomib(ACPIAC, acline_mib, &acline_mib_len) == 0) {
306 		acline_mode = ac_sysctl;
307 		if (vflag)
308 			warnx("using sysctl for AC line status");
309 #ifdef __powerpc__
310 	} else if ((skip_source_check || acline_mode_user == ac_sysctl) &&
311 		   sysctlnametomib(PMUAC, acline_mib, &acline_mib_len) == 0) {
312 		acline_mode = ac_sysctl;
313 		if (vflag)
314 			warnx("using sysctl for AC line status");
315 #endif
316 #ifdef USE_APM
317 	} else if ((skip_source_check || acline_mode_user == ac_apm) &&
318 		   (apm_fd = open(APMDEV, O_RDONLY)) >= 0) {
319 		if (vflag)
320 			warnx("using APM for AC line status");
321 		acline_mode = ac_apm;
322 #endif
323 	} else {
324 		warnx("unable to determine AC line status");
325 		acline_mode = ac_none;
326 	}
327 }
328 
329 static void
330 acline_read(void)
331 {
332 	if (acline_mode == ac_acpi_devd) {
333 		char buf[DEVCTL_MAXBUF], *ptr;
334 		ssize_t rlen;
335 		int notify;
336 
337 		rlen = read(devd_pipe, buf, sizeof(buf));
338 		if (rlen == 0 || (rlen < 0 && errno != EWOULDBLOCK)) {
339 			if (vflag)
340 				warnx("lost devd connection, switching to sysctl");
341 			devd_close();
342 			acline_mode = ac_sysctl;
343 			/* FALLTHROUGH */
344 		}
345 		if (rlen > 0 &&
346 		    (ptr = strstr(buf, "system=ACPI")) != NULL &&
347 		    (ptr = strstr(ptr, "subsystem=ACAD")) != NULL &&
348 		    (ptr = strstr(ptr, "notify=")) != NULL &&
349 		    sscanf(ptr, "notify=%x", &notify) == 1)
350 			acline_status = (notify ? SRC_AC : SRC_BATTERY);
351 	}
352 	if (acline_mode == ac_sysctl) {
353 		int acline;
354 		size_t len;
355 
356 		len = sizeof(acline);
357 		if (sysctl(acline_mib, acline_mib_len, &acline, &len,
358 		    NULL, 0) == 0)
359 			acline_status = (acline ? SRC_AC : SRC_BATTERY);
360 		else
361 			acline_status = SRC_UNKNOWN;
362 	}
363 #ifdef USE_APM
364 	if (acline_mode == ac_apm) {
365 		struct apm_info info;
366 
367 		if (ioctl(apm_fd, APMIO_GETINFO, &info) == 0) {
368 			acline_status = (info.ai_acline ? SRC_AC : SRC_BATTERY);
369 		} else {
370 			close(apm_fd);
371 			apm_fd = -1;
372 			acline_mode = ac_none;
373 			acline_status = SRC_UNKNOWN;
374 		}
375 	}
376 #endif
377 	/* try to (re)connect to devd */
378 #ifdef USE_APM
379 	if ((acline_mode == ac_sysctl &&
380 	    (acline_mode_user == ac_none ||
381 	     acline_mode_user == ac_acpi_devd)) ||
382 	    (acline_mode == ac_apm &&
383 	     acline_mode_user == ac_acpi_devd)) {
384 #else
385 	if (acline_mode == ac_sysctl &&
386 	    (acline_mode_user == ac_none ||
387 	     acline_mode_user == ac_acpi_devd)) {
388 #endif
389 		struct timeval now;
390 
391 		gettimeofday(&now, NULL);
392 		if (now.tv_sec > tried_devd.tv_sec + DEVD_RETRY_INTERVAL) {
393 			if (devd_init() >= 0) {
394 				if (vflag)
395 					warnx("using devd for AC line status");
396 				acline_mode = ac_acpi_devd;
397 			}
398 			tried_devd = now;
399 		}
400 	}
401 }
402 
403 static int
404 devd_init(void)
405 {
406 	struct sockaddr_un devd_addr;
407 
408 	bzero(&devd_addr, sizeof(devd_addr));
409 	if ((devd_pipe = socket(PF_LOCAL, SOCK_STREAM|SOCK_NONBLOCK, 0)) < 0) {
410 		if (vflag)
411 			warn("%s(): socket()", __func__);
412 		return (-1);
413 	}
414 
415 	devd_addr.sun_family = PF_LOCAL;
416 	strlcpy(devd_addr.sun_path, DEVDPIPE, sizeof(devd_addr.sun_path));
417 	if (connect(devd_pipe, (struct sockaddr *)&devd_addr,
418 	    sizeof(devd_addr)) == -1) {
419 		if (vflag)
420 			warn("%s(): connect()", __func__);
421 		close(devd_pipe);
422 		devd_pipe = -1;
423 		return (-1);
424 	}
425 
426 	return (devd_pipe);
427 }
428 
429 static void
430 devd_close(void)
431 {
432 
433 	close(devd_pipe);
434 	devd_pipe = -1;
435 }
436 
437 static void
438 parse_mode(char *arg, int *mode, int ch)
439 {
440 
441 	if (strcmp(arg, "minimum") == 0 || strcmp(arg, "min") == 0)
442 		*mode = MODE_MIN;
443 	else if (strcmp(arg, "maximum") == 0 || strcmp(arg, "max") == 0)
444 		*mode = MODE_MAX;
445 	else if (strcmp(arg, "adaptive") == 0 || strcmp(arg, "adp") == 0)
446 		*mode = MODE_ADAPTIVE;
447 	else if (strcmp(arg, "hiadaptive") == 0 || strcmp(arg, "hadp") == 0)
448 		*mode = MODE_HIADAPTIVE;
449 	else
450 		errx(1, "bad option: -%c %s", (char)ch, optarg);
451 }
452 
453 static void
454 parse_acline_mode(char *arg, int ch)
455 {
456 	if (strcmp(arg, "sysctl") == 0)
457 		acline_mode_user = ac_sysctl;
458 	else if (strcmp(arg, "devd") == 0)
459 		acline_mode_user = ac_acpi_devd;
460 #ifdef USE_APM
461 	else if (strcmp(arg, "apm") == 0)
462 		acline_mode_user = ac_apm;
463 #endif
464 	else
465 		errx(1, "bad option: -%c %s", (char)ch, optarg);
466 }
467 
468 static void
469 handle_sigs(int __unused sig)
470 {
471 
472 	exit_requested = 1;
473 }
474 
475 static void
476 usage(void)
477 {
478 
479 	fprintf(stderr,
480 "usage: powerd [-v] [-a mode] [-b mode] [-i %%] [-m freq] [-M freq] [-N] [-n mode] [-p ival] [-r %%] [-s source] [-P pidfile]\n");
481 	exit(1);
482 }
483 
484 int
485 main(int argc, char * argv[])
486 {
487 	struct timeval timeout;
488 	fd_set fdset;
489 	int nfds;
490 	struct pidfh *pfh = NULL;
491 	const char *pidfile = NULL;
492 	int freq, curfreq, initfreq, *freqs, i, j, *mwatts, numfreqs, load;
493 	int minfreq = -1, maxfreq = -1;
494 	int ch, mode, mode_ac, mode_battery, mode_none, idle, to;
495 	uint64_t mjoules_used;
496 	size_t len;
497 	int nonice;
498 
499 	/* Default mode for all AC states is adaptive. */
500 	mode_ac = mode_none = MODE_HIADAPTIVE;
501 	mode_battery = MODE_ADAPTIVE;
502 	cpu_running_mark = DEFAULT_ACTIVE_PERCENT;
503 	cpu_idle_mark = DEFAULT_IDLE_PERCENT;
504 	poll_ival = DEFAULT_POLL_INTERVAL;
505 	mjoules_used = 0;
506 	vflag = 0;
507 	nonice = 0;
508 
509 	/* User must be root to control frequencies. */
510 	if (geteuid() != 0)
511 		errx(1, "must be root to run");
512 
513 	while ((ch = getopt(argc, argv, "a:b:i:m:M:Nn:p:P:r:s:v")) != -1)
514 		switch (ch) {
515 		case 'a':
516 			parse_mode(optarg, &mode_ac, ch);
517 			break;
518 		case 'b':
519 			parse_mode(optarg, &mode_battery, ch);
520 			break;
521 		case 's':
522 			parse_acline_mode(optarg, ch);
523 			break;
524 		case 'i':
525 			cpu_idle_mark = atoi(optarg);
526 			if (cpu_idle_mark < 0 || cpu_idle_mark > 100) {
527 				warnx("%d is not a valid percent",
528 				    cpu_idle_mark);
529 				usage();
530 			}
531 			break;
532 		case 'm':
533 			minfreq = atoi(optarg);
534 			if (minfreq < 0) {
535 				warnx("%d is not a valid CPU frequency",
536 				    minfreq);
537 				usage();
538 			}
539 			break;
540 		case 'M':
541 			maxfreq = atoi(optarg);
542 			if (maxfreq < 0) {
543 				warnx("%d is not a valid CPU frequency",
544 				    maxfreq);
545 				usage();
546 			}
547 			break;
548 		case 'N':
549 			nonice = 1;
550 			break;
551 		case 'n':
552 			parse_mode(optarg, &mode_none, ch);
553 			break;
554 		case 'p':
555 			poll_ival = atoi(optarg);
556 			if (poll_ival < 5) {
557 				warnx("poll interval is in units of ms");
558 				usage();
559 			}
560 			break;
561 		case 'P':
562 			pidfile = optarg;
563 			break;
564 		case 'r':
565 			cpu_running_mark = atoi(optarg);
566 			if (cpu_running_mark <= 0 || cpu_running_mark > 100) {
567 				warnx("%d is not a valid percent",
568 				    cpu_running_mark);
569 				usage();
570 			}
571 			break;
572 		case 'v':
573 			vflag = 1;
574 			break;
575 		default:
576 			usage();
577 		}
578 
579 	mode = mode_none;
580 
581 	/* Poll interval is in units of ms. */
582 	poll_ival *= 1000;
583 
584 	/* Look up various sysctl MIBs. */
585 	len = 2;
586 	if (sysctlnametomib("kern.cp_times", cp_times_mib, &len))
587 		err(1, "lookup kern.cp_times");
588 	len = 4;
589 	if (sysctlnametomib("dev.cpu.0.freq", freq_mib, &len))
590 		err(EX_UNAVAILABLE, "no cpufreq(4) support -- aborting");
591 	len = 4;
592 	if (sysctlnametomib("dev.cpu.0.freq_levels", levels_mib, &len))
593 		err(1, "lookup freq_levels");
594 
595 	/* Check if we can read the load and supported freqs. */
596 	if (read_usage_times(NULL, nonice))
597 		err(1, "read_usage_times");
598 	if (read_freqs(&numfreqs, &freqs, &mwatts, minfreq, maxfreq))
599 		err(1, "error reading supported CPU frequencies");
600 	if (numfreqs == 0)
601 		errx(1, "no CPU frequencies in user-specified range");
602 
603 	/* Run in the background unless in verbose mode. */
604 	if (!vflag) {
605 		pid_t otherpid;
606 
607 		pfh = pidfile_open(pidfile, 0600, &otherpid);
608 		if (pfh == NULL) {
609 			if (errno == EEXIST) {
610 				errx(1, "powerd already running, pid: %d",
611 				    otherpid);
612 			}
613 			warn("cannot open pid file");
614 		}
615 		if (daemon(0, 0) != 0) {
616 			warn("cannot enter daemon mode, exiting");
617 			pidfile_remove(pfh);
618 			exit(EXIT_FAILURE);
619 
620 		}
621 		pidfile_write(pfh);
622 	}
623 
624 	/* Decide whether to use ACPI or APM to read the AC line status. */
625 	acline_init();
626 
627 	/*
628 	 * Exit cleanly on signals.
629 	 */
630 	signal(SIGINT, handle_sigs);
631 	signal(SIGTERM, handle_sigs);
632 
633 	freq = initfreq = curfreq = get_freq();
634 	i = get_freq_id(curfreq, freqs, numfreqs);
635 	if (freq < 1)
636 		freq = 1;
637 
638 	/*
639 	 * If we are in adaptive mode and the current frequency is outside the
640 	 * user-defined range, adjust it to be within the user-defined range.
641 	 */
642 	acline_read();
643 	if (acline_status > SRC_UNKNOWN)
644 		errx(1, "invalid AC line status %d", acline_status);
645 	if ((acline_status == SRC_AC &&
646 	    (mode_ac == MODE_ADAPTIVE || mode_ac == MODE_HIADAPTIVE)) ||
647 	    (acline_status == SRC_BATTERY &&
648 	    (mode_battery == MODE_ADAPTIVE || mode_battery == MODE_HIADAPTIVE)) ||
649 	    (acline_status == SRC_UNKNOWN &&
650 	    (mode_none == MODE_ADAPTIVE || mode_none == MODE_HIADAPTIVE))) {
651 		/* Read the current frequency. */
652 		len = sizeof(curfreq);
653 		if (sysctl(freq_mib, 4, &curfreq, &len, NULL, 0) != 0) {
654 			if (vflag)
655 				warn("error reading current CPU frequency");
656 		}
657 		if (curfreq < freqs[numfreqs - 1]) {
658 			if (vflag) {
659 				printf("CPU frequency is below user-defined "
660 				    "minimum; changing frequency to %d "
661 				    "MHz\n", freqs[numfreqs - 1]);
662 			}
663 			if (set_freq(freqs[numfreqs - 1]) != 0) {
664 				warn("error setting CPU freq %d",
665 				    freqs[numfreqs - 1]);
666 			}
667 		} else if (curfreq > freqs[0]) {
668 			if (vflag) {
669 				printf("CPU frequency is above user-defined "
670 				    "maximum; changing frequency to %d "
671 				    "MHz\n", freqs[0]);
672 			}
673 			if (set_freq(freqs[0]) != 0) {
674 				warn("error setting CPU freq %d",
675 				    freqs[0]);
676 			}
677 		}
678 	}
679 
680 	idle = 0;
681 	/* Main loop. */
682 	for (;;) {
683 		FD_ZERO(&fdset);
684 		if (devd_pipe >= 0) {
685 			FD_SET(devd_pipe, &fdset);
686 			nfds = devd_pipe + 1;
687 		} else {
688 			nfds = 0;
689 		}
690 		if (mode == MODE_HIADAPTIVE || idle < 120)
691 			to = poll_ival;
692 		else if (idle < 360)
693 			to = poll_ival * 2;
694 		else
695 			to = poll_ival * 4;
696 		timeout.tv_sec = to / 1000000;
697 		timeout.tv_usec = to % 1000000;
698 		select(nfds, &fdset, NULL, &fdset, &timeout);
699 
700 		/* If the user requested we quit, print some statistics. */
701 		if (exit_requested) {
702 			if (vflag && mjoules_used != 0)
703 				printf("total joules used: %u.%03u\n",
704 				    (u_int)(mjoules_used / 1000),
705 				    (int)mjoules_used % 1000);
706 			break;
707 		}
708 
709 		/* Read the current AC status and record the mode. */
710 		acline_read();
711 		switch (acline_status) {
712 		case SRC_AC:
713 			mode = mode_ac;
714 			break;
715 		case SRC_BATTERY:
716 			mode = mode_battery;
717 			break;
718 		case SRC_UNKNOWN:
719 			mode = mode_none;
720 			break;
721 		default:
722 			errx(1, "invalid AC line status %d", acline_status);
723 		}
724 
725 		/* Read the current frequency. */
726 		if (idle % 32 == 0) {
727 			if ((curfreq = get_freq()) == 0)
728 				continue;
729 			i = get_freq_id(curfreq, freqs, numfreqs);
730 		}
731 		idle++;
732 		if (vflag) {
733 			/* Keep a sum of all power actually used. */
734 			if (mwatts[i] != -1)
735 				mjoules_used +=
736 				    (mwatts[i] * (poll_ival / 1000)) / 1000;
737 		}
738 
739 		/* Always switch to the lowest frequency in min mode. */
740 		if (mode == MODE_MIN) {
741 			freq = freqs[numfreqs - 1];
742 			if (curfreq != freq) {
743 				if (vflag) {
744 					printf("now operating on %s power; "
745 					    "changing frequency to %d MHz\n",
746 					    modes[acline_status], freq);
747 				}
748 				idle = 0;
749 				if (set_freq(freq) != 0) {
750 					warn("error setting CPU freq %d",
751 					    freq);
752 					continue;
753 				}
754 			}
755 			continue;
756 		}
757 
758 		/* Always switch to the highest frequency in max mode. */
759 		if (mode == MODE_MAX) {
760 			freq = freqs[0];
761 			if (curfreq != freq) {
762 				if (vflag) {
763 					printf("now operating on %s power; "
764 					    "changing frequency to %d MHz\n",
765 					    modes[acline_status], freq);
766 				}
767 				idle = 0;
768 				if (set_freq(freq) != 0) {
769 					warn("error setting CPU freq %d",
770 					    freq);
771 					continue;
772 				}
773 			}
774 			continue;
775 		}
776 
777 		/* Adaptive mode; get the current CPU usage times. */
778 		if (read_usage_times(&load, nonice)) {
779 			if (vflag)
780 				warn("read_usage_times() failed");
781 			continue;
782 		}
783 
784 		if (mode == MODE_ADAPTIVE) {
785 			if (load > cpu_running_mark) {
786 				if (load > 95 || load > cpu_running_mark * 2)
787 					freq *= 2;
788 				else
789 					freq = freq * load / cpu_running_mark;
790 				if (freq > freqs[0])
791 					freq = freqs[0];
792 			} else if (load < cpu_idle_mark &&
793 			    curfreq * load < freqs[get_freq_id(
794 			    freq * 7 / 8, freqs, numfreqs)] *
795 			    cpu_running_mark) {
796 				freq = freq * 7 / 8;
797 				if (freq < freqs[numfreqs - 1])
798 					freq = freqs[numfreqs - 1];
799 			}
800 		} else { /* MODE_HIADAPTIVE */
801 			if (load > cpu_running_mark / 2) {
802 				if (load > 95 || load > cpu_running_mark)
803 					freq *= 4;
804 				else
805 					freq = freq * load * 2 / cpu_running_mark;
806 				if (freq > freqs[0] * 2)
807 					freq = freqs[0] * 2;
808 			} else if (load < cpu_idle_mark / 2 &&
809 			    curfreq * load < freqs[get_freq_id(
810 			    freq * 31 / 32, freqs, numfreqs)] *
811 			    cpu_running_mark / 2) {
812 				freq = freq * 31 / 32;
813 				if (freq < freqs[numfreqs - 1])
814 					freq = freqs[numfreqs - 1];
815 			}
816 		}
817 		if (vflag) {
818 		    printf("load %3d%%, current freq %4d MHz (%2d), wanted freq %4d MHz\n",
819 			load, curfreq, i, freq);
820 		}
821 		j = get_freq_id(freq, freqs, numfreqs);
822 		if (i != j) {
823 			if (vflag) {
824 				printf("changing clock"
825 				    " speed from %d MHz to %d MHz\n",
826 				    freqs[i], freqs[j]);
827 			}
828 			idle = 0;
829 			if (set_freq(freqs[j]))
830 				warn("error setting CPU frequency %d",
831 				    freqs[j]);
832 		}
833 	}
834 	if (set_freq(initfreq))
835 		warn("error setting CPU frequency %d", initfreq);
836 	free(freqs);
837 	free(mwatts);
838 	devd_close();
839 	if (!vflag)
840 		pidfile_remove(pfh);
841 
842 	exit(0);
843 }
844