1 /*-
2  * Copyright (c) 2004 Colin Percival
3  * Copyright (c) 2005 Nate Lawson
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted providing that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
19  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
23  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
24  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25  * POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD: stable/10/usr.sbin/powerd/powerd.c 342983 2019-01-13 02:27:10Z avos $");
30 
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);
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.
137  */
138 static int
read_usage_times(int * load)139 read_usage_times(int *load)
140 {
141 	static long *cp_times = NULL, *cp_times_old = NULL;
142 	static int ncpus = 0;
143 	size_t cp_times_len;
144 	int error, cpu, i, total;
145 
146 	if (cp_times == NULL) {
147 		cp_times_len = 0;
148 		error = sysctl(cp_times_mib, 2, NULL, &cp_times_len, NULL, 0);
149 		if (error)
150 			return (error);
151 		if ((cp_times = malloc(cp_times_len)) == NULL)
152 			return (errno);
153 		if ((cp_times_old = malloc(cp_times_len)) == NULL) {
154 			free(cp_times);
155 			cp_times = NULL;
156 			return (errno);
157 		}
158 		ncpus = cp_times_len / (sizeof(long) * CPUSTATES);
159 	}
160 
161 	cp_times_len = sizeof(long) * CPUSTATES * ncpus;
162 	error = sysctl(cp_times_mib, 2, cp_times, &cp_times_len, NULL, 0);
163 	if (error)
164 		return (error);
165 
166 	if (load) {
167 		*load = 0;
168 		for (cpu = 0; cpu < ncpus; cpu++) {
169 			total = 0;
170 			for (i = 0; i < CPUSTATES; i++) {
171 			    total += cp_times[cpu * CPUSTATES + i] -
172 				cp_times_old[cpu * CPUSTATES + i];
173 			}
174 			if (total == 0)
175 				continue;
176 			*load += 100 - (cp_times[cpu * CPUSTATES + CP_IDLE] -
177 			    cp_times_old[cpu * CPUSTATES + CP_IDLE]) * 100 / total;
178 		}
179 	}
180 
181 	memcpy(cp_times_old, cp_times, cp_times_len);
182 
183 	return (0);
184 }
185 
186 static int
read_freqs(int * numfreqs,int ** freqs,int ** power,int minfreq,int maxfreq)187 read_freqs(int *numfreqs, int **freqs, int **power, int minfreq, int maxfreq)
188 {
189 	char *freqstr, *p, *q;
190 	int i, j;
191 	size_t len = 0;
192 
193 	if (sysctl(levels_mib, 4, NULL, &len, NULL, 0))
194 		return (-1);
195 	if ((freqstr = malloc(len)) == NULL)
196 		return (-1);
197 	if (sysctl(levels_mib, 4, freqstr, &len, NULL, 0))
198 		return (-1);
199 
200 	*numfreqs = 1;
201 	for (p = freqstr; *p != '\0'; p++)
202 		if (*p == ' ')
203 			(*numfreqs)++;
204 
205 	if ((*freqs = malloc(*numfreqs * sizeof(int))) == NULL) {
206 		free(freqstr);
207 		return (-1);
208 	}
209 	if ((*power = malloc(*numfreqs * sizeof(int))) == NULL) {
210 		free(freqstr);
211 		free(*freqs);
212 		return (-1);
213 	}
214 	for (i = 0, j = 0, p = freqstr; i < *numfreqs; i++) {
215 		q = strchr(p, ' ');
216 		if (q != NULL)
217 			*q = '\0';
218 		if (sscanf(p, "%d/%d", &(*freqs)[j], &(*power)[i]) != 2) {
219 			free(freqstr);
220 			free(*freqs);
221 			free(*power);
222 			return (-1);
223 		}
224 		if (((*freqs)[j] >= minfreq || minfreq == -1) &&
225 		    ((*freqs)[j] <= maxfreq || maxfreq == -1))
226 			j++;
227 		p = q + 1;
228 	}
229 
230 	*numfreqs = j;
231 	if ((*freqs = realloc(*freqs, *numfreqs * sizeof(int))) == NULL) {
232 		free(freqstr);
233 		free(*freqs);
234 		free(*power);
235 		return (-1);
236 	}
237 
238 	free(freqstr);
239 	return (0);
240 }
241 
242 static int
get_freq(void)243 get_freq(void)
244 {
245 	size_t len;
246 	int curfreq;
247 
248 	len = sizeof(curfreq);
249 	if (sysctl(freq_mib, 4, &curfreq, &len, NULL, 0) != 0) {
250 		if (vflag)
251 			warn("error reading current CPU frequency");
252 		curfreq = 0;
253 	}
254 	return (curfreq);
255 }
256 
257 static int
set_freq(int freq)258 set_freq(int freq)
259 {
260 
261 	if (sysctl(freq_mib, 4, NULL, NULL, &freq, sizeof(freq))) {
262 		if (errno != EPERM)
263 			return (-1);
264 	}
265 
266 	return (0);
267 }
268 
269 static int
get_freq_id(int freq,int * freqs,int numfreqs)270 get_freq_id(int freq, int *freqs, int numfreqs)
271 {
272 	int i = 1;
273 
274 	while (i < numfreqs) {
275 		if (freqs[i] < freq)
276 			break;
277 		i++;
278 	}
279 	return (i - 1);
280 }
281 
282 /*
283  * Try to use ACPI to find the AC line status.  If this fails, fall back
284  * to APM.  If nothing succeeds, we'll just run in default mode.
285  */
286 static void
acline_init(void)287 acline_init(void)
288 {
289 	int skip_source_check;
290 
291 	acline_mib_len = 4;
292 	acline_status = SRC_UNKNOWN;
293 	skip_source_check = (acline_mode_user == ac_none ||
294 			     acline_mode_user == ac_acpi_devd);
295 
296 	if ((skip_source_check || acline_mode_user == ac_sysctl) &&
297 	    sysctlnametomib(ACPIAC, acline_mib, &acline_mib_len) == 0) {
298 		acline_mode = ac_sysctl;
299 		if (vflag)
300 			warnx("using sysctl for AC line status");
301 #if __powerpc__
302 	} else if ((skip_source_check || acline_mode_user == ac_sysctl) &&
303 		   sysctlnametomib(PMUAC, acline_mib, &acline_mib_len) == 0) {
304 		acline_mode = ac_sysctl;
305 		if (vflag)
306 			warnx("using sysctl for AC line status");
307 #endif
308 #ifdef USE_APM
309 	} else if ((skip_source_check || acline_mode_user == ac_apm) &&
310 		   (apm_fd = open(APMDEV, O_RDONLY)) >= 0) {
311 		if (vflag)
312 			warnx("using APM for AC line status");
313 		acline_mode = ac_apm;
314 #endif
315 	} else {
316 		warnx("unable to determine AC line status");
317 		acline_mode = ac_none;
318 	}
319 }
320 
321 static void
acline_read(void)322 acline_read(void)
323 {
324 	if (acline_mode == ac_acpi_devd) {
325 		char buf[DEVCTL_MAXBUF], *ptr;
326 		ssize_t rlen;
327 		int notify;
328 
329 		rlen = read(devd_pipe, buf, sizeof(buf));
330 		if (rlen == 0 || (rlen < 0 && errno != EWOULDBLOCK)) {
331 			if (vflag)
332 				warnx("lost devd connection, switching to sysctl");
333 			devd_close();
334 			acline_mode = ac_sysctl;
335 			/* FALLTHROUGH */
336 		}
337 		if (rlen > 0 &&
338 		    (ptr = strstr(buf, "system=ACPI")) != NULL &&
339 		    (ptr = strstr(ptr, "subsystem=ACAD")) != NULL &&
340 		    (ptr = strstr(ptr, "notify=")) != NULL &&
341 		    sscanf(ptr, "notify=%x", &notify) == 1)
342 			acline_status = (notify ? SRC_AC : SRC_BATTERY);
343 	}
344 	if (acline_mode == ac_sysctl) {
345 		int acline;
346 		size_t len;
347 
348 		len = sizeof(acline);
349 		if (sysctl(acline_mib, acline_mib_len, &acline, &len,
350 		    NULL, 0) == 0)
351 			acline_status = (acline ? SRC_AC : SRC_BATTERY);
352 		else
353 			acline_status = SRC_UNKNOWN;
354 	}
355 #ifdef USE_APM
356 	if (acline_mode == ac_apm) {
357 		struct apm_info info;
358 
359 		if (ioctl(apm_fd, APMIO_GETINFO, &info) == 0) {
360 			acline_status = (info.ai_acline ? SRC_AC : SRC_BATTERY);
361 		} else {
362 			close(apm_fd);
363 			apm_fd = -1;
364 			acline_mode = ac_none;
365 			acline_status = SRC_UNKNOWN;
366 		}
367 	}
368 #endif
369 	/* try to (re)connect to devd */
370 #ifdef USE_APM
371 	if ((acline_mode == ac_sysctl &&
372 	    (acline_mode_user == ac_none ||
373 	     acline_mode_user == ac_acpi_devd)) ||
374 	    (acline_mode == ac_apm &&
375 	     acline_mode_user == ac_acpi_devd)) {
376 #else
377 	if (acline_mode == ac_sysctl &&
378 	    (acline_mode_user == ac_none ||
379 	     acline_mode_user == ac_acpi_devd)) {
380 #endif
381 		struct timeval now;
382 
383 		gettimeofday(&now, NULL);
384 		if (now.tv_sec > tried_devd.tv_sec + DEVD_RETRY_INTERVAL) {
385 			if (devd_init() >= 0) {
386 				if (vflag)
387 					warnx("using devd for AC line status");
388 				acline_mode = ac_acpi_devd;
389 			}
390 			tried_devd = now;
391 		}
392 	}
393 }
394 
395 static int
396 devd_init(void)
397 {
398 	struct sockaddr_un devd_addr;
399 
400 	bzero(&devd_addr, sizeof(devd_addr));
401 	if ((devd_pipe = socket(PF_LOCAL, SOCK_STREAM, 0)) < 0) {
402 		if (vflag)
403 			warn("%s(): socket()", __func__);
404 		return (-1);
405 	}
406 
407 	devd_addr.sun_family = PF_LOCAL;
408 	strlcpy(devd_addr.sun_path, DEVDPIPE, sizeof(devd_addr.sun_path));
409 	if (connect(devd_pipe, (struct sockaddr *)&devd_addr,
410 	    sizeof(devd_addr)) == -1) {
411 		if (vflag)
412 			warn("%s(): connect()", __func__);
413 		close(devd_pipe);
414 		devd_pipe = -1;
415 		return (-1);
416 	}
417 
418 	if (fcntl(devd_pipe, F_SETFL, O_NONBLOCK) == -1) {
419 		if (vflag)
420 			warn("%s(): fcntl()", __func__);
421 		close(devd_pipe);
422 		return (-1);
423 	}
424 
425 	return (devd_pipe);
426 }
427 
428 static void
429 devd_close(void)
430 {
431 
432 	close(devd_pipe);
433 	devd_pipe = -1;
434 }
435 
436 static void
437 parse_mode(char *arg, int *mode, int ch)
438 {
439 
440 	if (strcmp(arg, "minimum") == 0 || strcmp(arg, "min") == 0)
441 		*mode = MODE_MIN;
442 	else if (strcmp(arg, "maximum") == 0 || strcmp(arg, "max") == 0)
443 		*mode = MODE_MAX;
444 	else if (strcmp(arg, "adaptive") == 0 || strcmp(arg, "adp") == 0)
445 		*mode = MODE_ADAPTIVE;
446 	else if (strcmp(arg, "hiadaptive") == 0 || strcmp(arg, "hadp") == 0)
447 		*mode = MODE_HIADAPTIVE;
448 	else
449 		errx(1, "bad option: -%c %s", (char)ch, optarg);
450 }
451 
452 static void
453 parse_acline_mode(char *arg, int ch)
454 {
455 	if (strcmp(arg, "sysctl") == 0)
456 		acline_mode_user = ac_sysctl;
457 	else if (strcmp(arg, "devd") == 0)
458 		acline_mode_user = ac_acpi_devd;
459 #ifdef USE_APM
460 	else if (strcmp(arg, "apm") == 0)
461 		acline_mode_user = ac_apm;
462 #endif
463 	else
464 		errx(1, "bad option: -%c %s", (char)ch, optarg);
465 }
466 
467 static void
468 handle_sigs(int __unused sig)
469 {
470 
471 	exit_requested = 1;
472 }
473 
474 static void
475 usage(void)
476 {
477 
478 	fprintf(stderr,
479 "usage: powerd [-v] [-a mode] [-b mode] [-i %%] [-m freq] [-M freq] [-n mode] [-p ival] [-r %%] [-s source] [-P pidfile]\n");
480 	exit(1);
481 }
482 
483 int
484 main(int argc, char * argv[])
485 {
486 	struct timeval timeout;
487 	fd_set fdset;
488 	int nfds;
489 	struct pidfh *pfh = NULL;
490 	const char *pidfile = NULL;
491 	int freq, curfreq, initfreq, *freqs, i, j, *mwatts, numfreqs, load;
492 	int minfreq = -1, maxfreq = -1;
493 	int ch, mode, mode_ac, mode_battery, mode_none, idle, to;
494 	uint64_t mjoules_used;
495 	size_t len;
496 
497 	/* Default mode for all AC states is adaptive. */
498 	mode_ac = mode_none = MODE_HIADAPTIVE;
499 	mode_battery = MODE_ADAPTIVE;
500 	cpu_running_mark = DEFAULT_ACTIVE_PERCENT;
501 	cpu_idle_mark = DEFAULT_IDLE_PERCENT;
502 	poll_ival = DEFAULT_POLL_INTERVAL;
503 	mjoules_used = 0;
504 	vflag = 0;
505 
506 	/* User must be root to control frequencies. */
507 	if (geteuid() != 0)
508 		errx(1, "must be root to run");
509 
510 	while ((ch = getopt(argc, argv, "a:b:i:m:M:n:p:P:r:s:v")) != -1)
511 		switch (ch) {
512 		case 'a':
513 			parse_mode(optarg, &mode_ac, ch);
514 			break;
515 		case 'b':
516 			parse_mode(optarg, &mode_battery, ch);
517 			break;
518 		case 's':
519 			parse_acline_mode(optarg, ch);
520 			break;
521 		case 'i':
522 			cpu_idle_mark = atoi(optarg);
523 			if (cpu_idle_mark < 0 || cpu_idle_mark > 100) {
524 				warnx("%d is not a valid percent",
525 				    cpu_idle_mark);
526 				usage();
527 			}
528 			break;
529 		case 'm':
530 			minfreq = atoi(optarg);
531 			if (minfreq < 0) {
532 				warnx("%d is not a valid CPU frequency",
533 				    minfreq);
534 				usage();
535 			}
536 			break;
537 		case 'M':
538 			maxfreq = atoi(optarg);
539 			if (maxfreq < 0) {
540 				warnx("%d is not a valid CPU frequency",
541 				    maxfreq);
542 				usage();
543 			}
544 			break;
545 		case 'n':
546 			parse_mode(optarg, &mode_none, ch);
547 			break;
548 		case 'p':
549 			poll_ival = atoi(optarg);
550 			if (poll_ival < 5) {
551 				warnx("poll interval is in units of ms");
552 				usage();
553 			}
554 			break;
555 		case 'P':
556 			pidfile = optarg;
557 			break;
558 		case 'r':
559 			cpu_running_mark = atoi(optarg);
560 			if (cpu_running_mark <= 0 || cpu_running_mark > 100) {
561 				warnx("%d is not a valid percent",
562 				    cpu_running_mark);
563 				usage();
564 			}
565 			break;
566 		case 'v':
567 			vflag = 1;
568 			break;
569 		default:
570 			usage();
571 		}
572 
573 	mode = mode_none;
574 
575 	/* Poll interval is in units of ms. */
576 	poll_ival *= 1000;
577 
578 	/* Look up various sysctl MIBs. */
579 	len = 2;
580 	if (sysctlnametomib("kern.cp_times", cp_times_mib, &len))
581 		err(1, "lookup kern.cp_times");
582 	len = 4;
583 	if (sysctlnametomib("dev.cpu.0.freq", freq_mib, &len))
584 		err(EX_UNAVAILABLE, "no cpufreq(4) support -- aborting");
585 	len = 4;
586 	if (sysctlnametomib("dev.cpu.0.freq_levels", levels_mib, &len))
587 		err(1, "lookup freq_levels");
588 
589 	/* Check if we can read the load and supported freqs. */
590 	if (read_usage_times(NULL))
591 		err(1, "read_usage_times");
592 	if (read_freqs(&numfreqs, &freqs, &mwatts, minfreq, maxfreq))
593 		err(1, "error reading supported CPU frequencies");
594 	if (numfreqs == 0)
595 		errx(1, "no CPU frequencies in user-specified range");
596 
597 	/* Run in the background unless in verbose mode. */
598 	if (!vflag) {
599 		pid_t otherpid;
600 
601 		pfh = pidfile_open(pidfile, 0600, &otherpid);
602 		if (pfh == NULL) {
603 			if (errno == EEXIST) {
604 				errx(1, "powerd already running, pid: %d",
605 				    otherpid);
606 			}
607 			warn("cannot open pid file");
608 		}
609 		if (daemon(0, 0) != 0) {
610 			warn("cannot enter daemon mode, exiting");
611 			pidfile_remove(pfh);
612 			exit(EXIT_FAILURE);
613 
614 		}
615 		pidfile_write(pfh);
616 	}
617 
618 	/* Decide whether to use ACPI or APM to read the AC line status. */
619 	acline_init();
620 
621 	/*
622 	 * Exit cleanly on signals.
623 	 */
624 	signal(SIGINT, handle_sigs);
625 	signal(SIGTERM, handle_sigs);
626 
627 	freq = initfreq = curfreq = get_freq();
628 	i = get_freq_id(curfreq, freqs, numfreqs);
629 	if (freq < 1)
630 		freq = 1;
631 
632 	/*
633 	 * If we are in adaptive mode and the current frequency is outside the
634 	 * user-defined range, adjust it to be within the user-defined range.
635 	 */
636 	acline_read();
637 	if (acline_status > SRC_UNKNOWN)
638 		errx(1, "invalid AC line status %d", acline_status);
639 	if ((acline_status == SRC_AC &&
640 	    (mode_ac == MODE_ADAPTIVE || mode_ac == MODE_HIADAPTIVE)) ||
641 	    (acline_status == SRC_BATTERY &&
642 	    (mode_battery == MODE_ADAPTIVE || mode_battery == MODE_HIADAPTIVE)) ||
643 	    (acline_status == SRC_UNKNOWN &&
644 	    (mode_none == MODE_ADAPTIVE || mode_none == MODE_HIADAPTIVE))) {
645 		/* Read the current frequency. */
646 		len = sizeof(curfreq);
647 		if (sysctl(freq_mib, 4, &curfreq, &len, NULL, 0) != 0) {
648 			if (vflag)
649 				warn("error reading current CPU frequency");
650 		}
651 		if (curfreq < freqs[numfreqs - 1]) {
652 			if (vflag) {
653 				printf("CPU frequency is below user-defined "
654 				    "minimum; changing frequency to %d "
655 				    "MHz\n", freqs[numfreqs - 1]);
656 			}
657 			if (set_freq(freqs[numfreqs - 1]) != 0) {
658 				warn("error setting CPU freq %d",
659 				    freqs[numfreqs - 1]);
660 			}
661 		} else if (curfreq > freqs[0]) {
662 			if (vflag) {
663 				printf("CPU frequency is above user-defined "
664 				    "maximum; changing frequency to %d "
665 				    "MHz\n", freqs[0]);
666 			}
667 			if (set_freq(freqs[0]) != 0) {
668 				warn("error setting CPU freq %d",
669 				    freqs[0]);
670 			}
671 		}
672 	}
673 
674 	idle = 0;
675 	/* Main loop. */
676 	for (;;) {
677 		FD_ZERO(&fdset);
678 		if (devd_pipe >= 0) {
679 			FD_SET(devd_pipe, &fdset);
680 			nfds = devd_pipe + 1;
681 		} else {
682 			nfds = 0;
683 		}
684 		if (mode == MODE_HIADAPTIVE || idle < 120)
685 			to = poll_ival;
686 		else if (idle < 360)
687 			to = poll_ival * 2;
688 		else
689 			to = poll_ival * 4;
690 		timeout.tv_sec = to / 1000000;
691 		timeout.tv_usec = to % 1000000;
692 		select(nfds, &fdset, NULL, &fdset, &timeout);
693 
694 		/* If the user requested we quit, print some statistics. */
695 		if (exit_requested) {
696 			if (vflag && mjoules_used != 0)
697 				printf("total joules used: %u.%03u\n",
698 				    (u_int)(mjoules_used / 1000),
699 				    (int)mjoules_used % 1000);
700 			break;
701 		}
702 
703 		/* Read the current AC status and record the mode. */
704 		acline_read();
705 		switch (acline_status) {
706 		case SRC_AC:
707 			mode = mode_ac;
708 			break;
709 		case SRC_BATTERY:
710 			mode = mode_battery;
711 			break;
712 		case SRC_UNKNOWN:
713 			mode = mode_none;
714 			break;
715 		default:
716 			errx(1, "invalid AC line status %d", acline_status);
717 		}
718 
719 		/* Read the current frequency. */
720 		if (idle % 32 == 0) {
721 			if ((curfreq = get_freq()) == 0)
722 				continue;
723 			i = get_freq_id(curfreq, freqs, numfreqs);
724 		}
725 		idle++;
726 		if (vflag) {
727 			/* Keep a sum of all power actually used. */
728 			if (mwatts[i] != -1)
729 				mjoules_used +=
730 				    (mwatts[i] * (poll_ival / 1000)) / 1000;
731 		}
732 
733 		/* Always switch to the lowest frequency in min mode. */
734 		if (mode == MODE_MIN) {
735 			freq = freqs[numfreqs - 1];
736 			if (curfreq != freq) {
737 				if (vflag) {
738 					printf("now operating on %s power; "
739 					    "changing frequency to %d MHz\n",
740 					    modes[acline_status], freq);
741 				}
742 				idle = 0;
743 				if (set_freq(freq) != 0) {
744 					warn("error setting CPU freq %d",
745 					    freq);
746 					continue;
747 				}
748 			}
749 			continue;
750 		}
751 
752 		/* Always switch to the highest frequency in max mode. */
753 		if (mode == MODE_MAX) {
754 			freq = freqs[0];
755 			if (curfreq != freq) {
756 				if (vflag) {
757 					printf("now operating on %s power; "
758 					    "changing frequency to %d MHz\n",
759 					    modes[acline_status], freq);
760 				}
761 				idle = 0;
762 				if (set_freq(freq) != 0) {
763 					warn("error setting CPU freq %d",
764 					    freq);
765 					continue;
766 				}
767 			}
768 			continue;
769 		}
770 
771 		/* Adaptive mode; get the current CPU usage times. */
772 		if (read_usage_times(&load)) {
773 			if (vflag)
774 				warn("read_usage_times() failed");
775 			continue;
776 		}
777 
778 		if (mode == MODE_ADAPTIVE) {
779 			if (load > cpu_running_mark) {
780 				if (load > 95 || load > cpu_running_mark * 2)
781 					freq *= 2;
782 				else
783 					freq = freq * load / cpu_running_mark;
784 				if (freq > freqs[0])
785 					freq = freqs[0];
786 			} else if (load < cpu_idle_mark &&
787 			    curfreq * load < freqs[get_freq_id(
788 			    freq * 7 / 8, freqs, numfreqs)] *
789 			    cpu_running_mark) {
790 				freq = freq * 7 / 8;
791 				if (freq < freqs[numfreqs - 1])
792 					freq = freqs[numfreqs - 1];
793 			}
794 		} else { /* MODE_HIADAPTIVE */
795 			if (load > cpu_running_mark / 2) {
796 				if (load > 95 || load > cpu_running_mark)
797 					freq *= 4;
798 				else
799 					freq = freq * load * 2 / cpu_running_mark;
800 				if (freq > freqs[0] * 2)
801 					freq = freqs[0] * 2;
802 			} else if (load < cpu_idle_mark / 2 &&
803 			    curfreq * load < freqs[get_freq_id(
804 			    freq * 31 / 32, freqs, numfreqs)] *
805 			    cpu_running_mark / 2) {
806 				freq = freq * 31 / 32;
807 				if (freq < freqs[numfreqs - 1])
808 					freq = freqs[numfreqs - 1];
809 			}
810 		}
811 		if (vflag) {
812 		    printf("load %3d%%, current freq %4d MHz (%2d), wanted freq %4d MHz\n",
813 			load, curfreq, i, freq);
814 		}
815 		j = get_freq_id(freq, freqs, numfreqs);
816 		if (i != j) {
817 			if (vflag) {
818 				printf("changing clock"
819 				    " speed from %d MHz to %d MHz\n",
820 				    freqs[i], freqs[j]);
821 			}
822 			idle = 0;
823 			if (set_freq(freqs[j]))
824 				warn("error setting CPU frequency %d",
825 				    freqs[j]);
826 		}
827 	}
828 	if (set_freq(initfreq))
829 		warn("error setting CPU frequency %d", initfreq);
830 	free(freqs);
831 	free(mwatts);
832 	devd_close();
833 	if (!vflag)
834 		pidfile_remove(pfh);
835 
836 	exit(0);
837 }
838