xref: /freebsd/usr.sbin/iostat/iostat.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1997, 1998, 2000, 2001  Kenneth D. Merry
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  * 3. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 /*
31  * Parts of this program are derived from the original FreeBSD iostat
32  * program:
33  */
34 /*-
35  * Copyright (c) 1986, 1991, 1993
36  *	The Regents of the University of California.  All rights reserved.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  * 4. Neither the name of the University nor the names of its contributors
47  *    may be used to endorse or promote products derived from this software
48  *    without specific prior written permission.
49  *
50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60  * SUCH DAMAGE.
61  */
62 /*
63  * Ideas for the new iostat statistics output modes taken from the NetBSD
64  * version of iostat:
65  */
66 /*
67  * Copyright (c) 1996 John M. Vinopal
68  * All rights reserved.
69  *
70  * Redistribution and use in source and binary forms, with or without
71  * modification, are permitted provided that the following conditions
72  * are met:
73  * 1. Redistributions of source code must retain the above copyright
74  *    notice, this list of conditions and the following disclaimer.
75  * 2. Redistributions in binary form must reproduce the above copyright
76  *    notice, this list of conditions and the following disclaimer in the
77  *    documentation and/or other materials provided with the distribution.
78  * 3. All advertising materials mentioning features or use of this software
79  *    must display the following acknowledgement:
80  *      This product includes software developed for the NetBSD Project
81  *      by John M. Vinopal.
82  * 4. The name of the author may not be used to endorse or promote products
83  *    derived from this software without specific prior written permission.
84  *
85  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
86  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
87  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
88  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
89  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
90  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
91  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
92  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
93  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
94  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
95  * SUCH DAMAGE.
96  */
97 
98 
99 #include <sys/param.h>
100 #include <sys/errno.h>
101 #include <sys/resource.h>
102 #include <sys/sysctl.h>
103 
104 #include <ctype.h>
105 #include <devstat.h>
106 #include <err.h>
107 #include <fcntl.h>
108 #include <inttypes.h>
109 #include <kvm.h>
110 #include <limits.h>
111 #include <math.h>
112 #include <nlist.h>
113 #include <signal.h>
114 #include <stdio.h>
115 #include <stdlib.h>
116 #include <string.h>
117 #include <termios.h>
118 #include <unistd.h>
119 
120 static struct nlist namelist[] = {
121 #define X_TTY_NIN	0
122 	{ .n_name = "_tty_nin",
123 	  .n_type = 0, .n_other = 0, .n_desc = 0, .n_value = 0 },
124 #define X_TTY_NOUT	1
125 	{ .n_name = "_tty_nout",
126 	  .n_type = 0, .n_other = 0, .n_desc = 0, .n_value = 0 },
127 #define X_BOOTTIME	2
128 	{ .n_name = "_boottime",
129 	  .n_type = 0, .n_other = 0, .n_desc = 0, .n_value = 0 },
130 #define X_END		2
131 	{ .n_name = NULL,
132 	  .n_type = 0, .n_other = 0, .n_desc = 0, .n_value = 0 },
133 };
134 
135 #define	IOSTAT_DEFAULT_ROWS	20	/* Traditional default `wrows' */
136 
137 static struct statinfo cur, last;
138 static int num_devices;
139 static struct device_selection *dev_select;
140 static int maxshowdevs;
141 static volatile sig_atomic_t headercount;
142 static volatile sig_atomic_t wresized;	/* Tty resized, when non-zero. */
143 static volatile sig_atomic_t alarm_rang;
144 static volatile sig_atomic_t return_requested;
145 static unsigned short wrows;		/* Current number of tty rows. */
146 static int dflag = 0, Iflag = 0, Cflag = 0, Tflag = 0, oflag = 0, Kflag = 0;
147 static int xflag = 0, zflag = 0;
148 
149 /* local function declarations */
150 static void usage(void) __dead2;
151 static void needhdr(int signo);
152 static void needresize(int signo);
153 static void needreturn(int signo);
154 static void alarm_clock(int signo);
155 static void doresize(void);
156 static void phdr(void);
157 static void devstats(int perf_select, long double etime, int havelast);
158 static void cpustats(void);
159 static int readvar(kvm_t *kd, const char *name, int nlid, void *ptr,
160 		   size_t len);
161 
162 static void
163 usage(void)
164 {
165 	/*
166 	 * We also support the following 'traditional' syntax:
167 	 * iostat [drives] [wait [count]]
168 	 * This isn't mentioned in the man page, or the usage statement,
169 	 * but it is supported.
170 	 */
171 	fprintf(stderr, "usage: iostat [-CdhIKoTxz] [-c count] [-M core]"
172 		" [-n devs] [-N system]\n"
173 		"\t      [-t type,if,pass] [-w wait] [drives]\n");
174 	exit(1);
175 }
176 
177 int
178 main(int argc, char **argv)
179 {
180 	int c, i;
181 	int hflag = 0, cflag = 0, wflag = 0, nflag = 0;
182 	int count = 0, waittime = 0;
183 	char *memf = NULL, *nlistf = NULL;
184 	struct devstat_match *matches;
185 	struct itimerval alarmspec;
186 	int num_matches = 0;
187 	char errbuf[_POSIX2_LINE_MAX];
188 	kvm_t *kd = NULL;
189 	long generation;
190 	int num_devices_specified;
191 	int num_selected, num_selections;
192 	long select_generation;
193 	char **specified_devices;
194 	devstat_select_mode select_mode;
195 	float f;
196 	int havelast = 0;
197 
198 	matches = NULL;
199 	maxshowdevs = 3;
200 
201 	while ((c = getopt(argc, argv, "Cc:dhIKM:N:n:oTt:w:xz")) != -1) {
202 		switch (c) {
203 			case 'C':
204 				Cflag++;
205 				break;
206 			case 'c':
207 				cflag++;
208 				count = atoi(optarg);
209 				if (count < 1)
210 					errx(1, "count %d is < 1", count);
211 				break;
212 			case 'd':
213 				dflag++;
214 				break;
215 			case 'h':
216 				hflag++;
217 				break;
218 			case 'I':
219 				Iflag++;
220 				break;
221 			case 'K':
222 				Kflag++;
223 				break;
224 			case 'M':
225 				memf = optarg;
226 				break;
227 			case 'N':
228 				nlistf = optarg;
229 				break;
230 			case 'n':
231 				nflag++;
232 				maxshowdevs = atoi(optarg);
233 				if (maxshowdevs < 0)
234 					errx(1, "number of devices %d is < 0",
235 					     maxshowdevs);
236 				break;
237 			case 'o':
238 				oflag++;
239 				break;
240 			case 'T':
241 				Tflag++;
242 				break;
243 			case 't':
244 				if (devstat_buildmatch(optarg, &matches,
245 						       &num_matches) != 0)
246 					errx(1, "%s", devstat_errbuf);
247 				break;
248 			case 'w':
249 				wflag++;
250 				f = atof(optarg);
251 				waittime = f * 1000;
252 				if (waittime < 1)
253 					errx(1, "wait time is < 1ms");
254 				break;
255 			case 'x':
256 				xflag++;
257 				break;
258 			case 'z':
259 				zflag++;
260 				break;
261 			default:
262 				usage();
263 		}
264 	}
265 
266 	argc -= optind;
267 	argv += optind;
268 
269 	if (nlistf != NULL || memf != NULL) {
270 		kd = kvm_openfiles(nlistf, memf, NULL, O_RDONLY, errbuf);
271 
272 		if (kd == NULL)
273 			errx(1, "kvm_openfiles: %s", errbuf);
274 
275 		if (kvm_nlist(kd, namelist) == -1)
276 			errx(1, "kvm_nlist: %s", kvm_geterr(kd));
277 	}
278 
279 	/*
280 	 * Make sure that the userland devstat version matches the kernel
281 	 * devstat version.  If not, exit and print a message informing
282 	 * the user of his mistake.
283 	 */
284 	if (devstat_checkversion(kd) < 0)
285 		errx(1, "%s", devstat_errbuf);
286 
287 	/*
288 	 * Make sure Tflag and/or Cflag are set if dflag == 0.  If dflag is
289 	 * greater than 0, they may be 0 or non-zero.
290 	 */
291 	if (dflag == 0 && xflag == 0) {
292 		Cflag = 1;
293 		Tflag = 1;
294 	}
295 
296 	/* find out how many devices we have */
297 	if ((num_devices = devstat_getnumdevs(kd)) < 0)
298 		err(1, "can't get number of devices");
299 
300 	/*
301 	 * Figure out how many devices we should display.
302 	 */
303 	if (nflag == 0) {
304 		if (xflag > 0)
305 			maxshowdevs = num_devices;
306 		else if (oflag > 0) {
307 			if ((dflag > 0) && (Cflag == 0) && (Tflag == 0))
308 				maxshowdevs = 5;
309 			else if ((dflag > 0) && (Tflag > 0) && (Cflag == 0))
310 				maxshowdevs = 5;
311 			else
312 				maxshowdevs = 4;
313 		} else {
314 			if ((dflag > 0) && (Cflag == 0))
315 				maxshowdevs = 4;
316 			else
317 				maxshowdevs = 3;
318 		}
319 	}
320 
321 	cur.dinfo = (struct devinfo *)calloc(1, sizeof(struct devinfo));
322 	if (cur.dinfo == NULL)
323 		err(1, "calloc failed");
324 
325 	last.dinfo = (struct devinfo *)calloc(1, sizeof(struct devinfo));
326 	if (last.dinfo == NULL)
327 		err(1, "calloc failed");
328 
329 	/*
330 	 * Grab all the devices.  We don't look to see if the list has
331 	 * changed here, since it almost certainly has.  We only look for
332 	 * errors.
333 	 */
334 	if (devstat_getdevs(kd, &cur) == -1)
335 		errx(1, "%s", devstat_errbuf);
336 
337 	num_devices = cur.dinfo->numdevs;
338 	generation = cur.dinfo->generation;
339 
340 	/*
341 	 * If the user specified any devices on the command line, see if
342 	 * they are in the list of devices we have now.
343 	 */
344 	specified_devices = (char **)malloc(sizeof(char *));
345 	if (specified_devices == NULL)
346 		err(1, "malloc failed");
347 
348 	for (num_devices_specified = 0; *argv; ++argv) {
349 		if (isdigit(**argv))
350 			break;
351 		num_devices_specified++;
352 		specified_devices = (char **)realloc(specified_devices,
353 						     sizeof(char *) *
354 						     num_devices_specified);
355 		if (specified_devices == NULL)
356 			err(1, "realloc failed");
357 
358 		specified_devices[num_devices_specified - 1] = *argv;
359 
360 	}
361 	if (nflag == 0 && maxshowdevs < num_devices_specified)
362 		maxshowdevs = num_devices_specified;
363 
364 	dev_select = NULL;
365 
366 	if ((num_devices_specified == 0) && (num_matches == 0))
367 		select_mode = DS_SELECT_ADD;
368 	else
369 		select_mode = DS_SELECT_ONLY;
370 
371 	/*
372 	 * At this point, selectdevs will almost surely indicate that the
373 	 * device list has changed, so we don't look for return values of 0
374 	 * or 1.  If we get back -1, though, there is an error.
375 	 */
376 	if (devstat_selectdevs(&dev_select, &num_selected,
377 			       &num_selections, &select_generation, generation,
378 			       cur.dinfo->devices, num_devices, matches,
379 			       num_matches, specified_devices,
380 			       num_devices_specified, select_mode, maxshowdevs,
381 			       hflag) == -1)
382 		errx(1, "%s", devstat_errbuf);
383 
384 	/*
385 	 * Look for the traditional wait time and count arguments.
386 	 */
387 	if (*argv) {
388 		f = atof(*argv);
389 		waittime = f * 1000;
390 
391 		/* Let the user know he goofed, but keep going anyway */
392 		if (wflag != 0)
393 			warnx("discarding previous wait interval, using"
394 			      " %g instead", waittime / 1000.0);
395 		wflag++;
396 
397 		if (*++argv) {
398 			count = atoi(*argv);
399 			if (cflag != 0)
400 				warnx("discarding previous count, using %d"
401 				      " instead", count);
402 			cflag++;
403 		} else
404 			count = -1;
405 	}
406 
407 	/*
408 	 * If the user specified a count, but not an interval, we default
409 	 * to an interval of 1 second.
410 	 */
411 	if ((wflag == 0) && (cflag > 0))
412 		waittime = 1 * 1000;
413 
414 	/*
415 	 * If the user specified a wait time, but not a count, we want to
416 	 * go on ad infinitum.  This can be redundant if the user uses the
417 	 * traditional method of specifying the wait, since in that case we
418 	 * already set count = -1 above.  Oh well.
419 	 */
420 	if ((wflag > 0) && (cflag == 0))
421 		count = -1;
422 
423 	bzero(cur.cp_time, sizeof(cur.cp_time));
424 	cur.tk_nout = 0;
425 	cur.tk_nin = 0;
426 
427 	/*
428 	 * Set the snap time to the system boot time (ie: zero), so the
429 	 * stats are calculated since system boot.
430 	 */
431 	cur.snap_time = 0;
432 
433 	/*
434 	 * If the user stops the program (control-Z) and then resumes it,
435 	 * print out the header again.
436 	 */
437 	(void)signal(SIGCONT, needhdr);
438 
439 	/*
440 	 * If our standard output is a tty, then install a SIGWINCH handler
441 	 * and set wresized so that our first iteration through the main
442 	 * iostat loop will peek at the terminal's current rows to find out
443 	 * how many lines can fit in a screenful of output.
444 	 */
445 	if (isatty(fileno(stdout)) != 0) {
446 		wresized = 1;
447 		(void)signal(SIGWINCH, needresize);
448 	} else {
449 		wresized = 0;
450 		wrows = IOSTAT_DEFAULT_ROWS;
451 	}
452 
453 	/*
454 	 * Register a SIGINT handler so that we can print out final statistics
455 	 * when we get that signal
456 	 */
457 	(void)signal(SIGINT, needreturn);
458 
459 	/*
460 	 * Register a SIGALRM handler to implement sleeps if the user uses the
461 	 * -c or -w options
462 	 */
463 	(void)signal(SIGALRM, alarm_clock);
464 	alarmspec.it_interval.tv_sec = waittime / 1000;
465 	alarmspec.it_interval.tv_usec = 1000 * (waittime % 1000);
466 	alarmspec.it_value.tv_sec = waittime / 1000;
467 	alarmspec.it_value.tv_usec = 1000 * (waittime % 1000);
468 	setitimer(ITIMER_REAL, &alarmspec, NULL);
469 
470 	for (headercount = 1;;) {
471 		struct devinfo *tmp_dinfo;
472 		long tmp;
473 		long double etime;
474 		sigset_t sigmask, oldsigmask;
475 
476 		if (Tflag > 0) {
477 			if ((readvar(kd, "kern.tty_nin", X_TTY_NIN, &cur.tk_nin,
478 			     sizeof(cur.tk_nin)) != 0)
479 			 || (readvar(kd, "kern.tty_nout", X_TTY_NOUT,
480 			     &cur.tk_nout, sizeof(cur.tk_nout))!= 0)) {
481 				Tflag = 0;
482 				warnx("disabling TTY statistics");
483 			}
484 		 }
485 
486 		if (Cflag > 0) {
487 			if (kd == NULL) {
488 				if (readvar(kd, "kern.cp_time", 0,
489 				    &cur.cp_time, sizeof(cur.cp_time)) != 0)
490 					Cflag = 0;
491 			} else {
492 				if (kvm_getcptime(kd, cur.cp_time) < 0) {
493 					warnx("kvm_getcptime: %s",
494 					    kvm_geterr(kd));
495 					Cflag = 0;
496 				}
497 			}
498 			if (Cflag == 0)
499 				warnx("disabling CPU time statistics");
500 		}
501 
502 		if (!--headercount) {
503 			phdr();
504 			if (wresized != 0)
505 				doresize();
506 			headercount = wrows;
507 		}
508 
509 		tmp_dinfo = last.dinfo;
510 		last.dinfo = cur.dinfo;
511 		cur.dinfo = tmp_dinfo;
512 
513 		last.snap_time = cur.snap_time;
514 
515 		/*
516 		 * Here what we want to do is refresh our device stats.
517 		 * devstat_getdevs() returns 1 when the device list has changed.
518 		 * If the device list has changed, we want to go through
519 		 * the selection process again, in case a device that we
520 		 * were previously displaying has gone away.
521 		 */
522 		switch (devstat_getdevs(kd, &cur)) {
523 		case -1:
524 			errx(1, "%s", devstat_errbuf);
525 			break;
526 		case 1: {
527 			int retval;
528 
529 			num_devices = cur.dinfo->numdevs;
530 			generation = cur.dinfo->generation;
531 			retval = devstat_selectdevs(&dev_select, &num_selected,
532 						    &num_selections,
533 						    &select_generation,
534 						    generation,
535 						    cur.dinfo->devices,
536 						    num_devices, matches,
537 						    num_matches,
538 						    specified_devices,
539 						    num_devices_specified,
540 						    select_mode, maxshowdevs,
541 						    hflag);
542 			switch(retval) {
543 			case -1:
544 				errx(1, "%s", devstat_errbuf);
545 				break;
546 			case 1:
547 				phdr();
548 				if (wresized != 0)
549 					doresize();
550 				headercount = wrows;
551 				break;
552 			default:
553 				break;
554 			}
555 			break;
556 		}
557 		default:
558 			break;
559 		}
560 
561 		/*
562 		 * We only want to re-select devices if we're in 'top'
563 		 * mode.  This is the only mode where the devices selected
564 		 * could actually change.
565 		 */
566 		if (hflag > 0) {
567 			int retval;
568 			retval = devstat_selectdevs(&dev_select, &num_selected,
569 						    &num_selections,
570 						    &select_generation,
571 						    generation,
572 						    cur.dinfo->devices,
573 						    num_devices, matches,
574 						    num_matches,
575 						    specified_devices,
576 						    num_devices_specified,
577 						    select_mode, maxshowdevs,
578 						    hflag);
579 			switch(retval) {
580 			case -1:
581 				errx(1,"%s", devstat_errbuf);
582 				break;
583 			case 1:
584 				phdr();
585 				if (wresized != 0)
586 					doresize();
587 				headercount = wrows;
588 				break;
589 			default:
590 				break;
591 			}
592 		}
593 
594 		if (Tflag > 0) {
595 			tmp = cur.tk_nin;
596 			cur.tk_nin -= last.tk_nin;
597 			last.tk_nin = tmp;
598 			tmp = cur.tk_nout;
599 			cur.tk_nout -= last.tk_nout;
600 			last.tk_nout = tmp;
601 		}
602 
603 		etime = cur.snap_time - last.snap_time;
604 
605 		if (etime == 0.0)
606 			etime = 1.0;
607 
608 		for (i = 0; i < CPUSTATES; i++) {
609 			tmp = cur.cp_time[i];
610 			cur.cp_time[i] -= last.cp_time[i];
611 			last.cp_time[i] = tmp;
612 		}
613 
614 		if (xflag == 0 && Tflag > 0)
615 			printf("%4.0Lf %5.0Lf ", cur.tk_nin / etime,
616 			    cur.tk_nout / etime);
617 
618 		devstats(hflag, etime, havelast);
619 
620 		if (xflag == 0) {
621 			if (Cflag > 0)
622 				cpustats();
623 
624 			printf("\n");
625 		}
626 		fflush(stdout);
627 
628 		if ((count >= 0 && --count <= 0) || return_requested)
629 			break;
630 
631 		/*
632 		 * Use sigsuspend to safely sleep until either signal is
633 		 * received
634 		 */
635 		alarm_rang = 0;
636 		sigemptyset(&sigmask);
637 		sigaddset(&sigmask, SIGINT);
638 		sigaddset(&sigmask, SIGALRM);
639 		sigprocmask(SIG_BLOCK, &sigmask, &oldsigmask);
640 		while (! (alarm_rang || return_requested) ) {
641 			sigsuspend(&oldsigmask);
642 		}
643 		sigprocmask(SIG_UNBLOCK, &sigmask, NULL);
644 
645 		havelast = 1;
646 	}
647 
648 	exit(0);
649 }
650 
651 /*
652  * Force a header to be prepended to the next output.
653  */
654 void
655 needhdr(int signo __unused)
656 {
657 
658 	headercount = 1;
659 }
660 
661 /*
662  * When the terminal is resized, force an update of the maximum number of rows
663  * printed between each header repetition.  Then force a new header to be
664  * prepended to the next output.
665  */
666 void
667 needresize(int signo __unused)
668 {
669 
670 	wresized = 1;
671 	headercount = 1;
672 }
673 
674 /*
675  * Record the alarm so the main loop can break its sleep
676  */
677 void
678 alarm_clock(int signo __unused)
679 {
680 	alarm_rang = 1;
681 }
682 
683 /*
684  * Request that the main loop exit soon
685  */
686 void
687 needreturn(int signo __unused)
688 {
689 	return_requested = 1;
690 }
691 
692 /*
693  * Update the global `wrows' count of terminal rows.
694  */
695 void
696 doresize(void)
697 {
698 	int status;
699 	struct winsize w;
700 
701 	for (;;) {
702 		status = ioctl(fileno(stdout), TIOCGWINSZ, &w);
703 		if (status == -1 && errno == EINTR)
704 			continue;
705 		else if (status == -1)
706 			err(1, "ioctl");
707 		if (w.ws_row > 3)
708 			wrows = w.ws_row - 3;
709 		else
710 			wrows = IOSTAT_DEFAULT_ROWS;
711 		break;
712 	}
713 
714 	/*
715 	 * Inhibit doresize() calls until we are rescheduled by SIGWINCH.
716 	 */
717 	wresized = 0;
718 }
719 
720 static void
721 phdr(void)
722 {
723 	int i, printed;
724 	char devbuf[256];
725 
726 	/*
727 	 * If xflag is set, we need a per-loop header, not a page header, so
728 	 * just return.  We'll print the header in devstats().
729 	 */
730 	if (xflag > 0)
731 		return;
732 
733 	if (Tflag > 0)
734 		(void)printf("       tty ");
735 	for (i = 0, printed=0;(i < num_devices) && (printed < maxshowdevs);i++){
736 		int di;
737 		if ((dev_select[i].selected != 0)
738 		 && (dev_select[i].selected <= maxshowdevs)) {
739 			di = dev_select[i].position;
740 			snprintf(devbuf, sizeof(devbuf), "%s%d",
741 					    cur.dinfo->devices[di].device_name,
742 					    cur.dinfo->devices[di].unit_number);
743 			if (oflag > 0)
744 				(void)printf("%13.6s ", devbuf);
745 			else
746 				printf("%16.6s ", devbuf);
747 			printed++;
748 		}
749 	}
750 	if (Cflag > 0)
751 		(void)printf("            cpu\n");
752 	else
753 		(void)printf("\n");
754 
755 	if (Tflag > 0)
756 		(void)printf(" tin  tout ");
757 
758 	for (i=0, printed = 0;(i < num_devices) && (printed < maxshowdevs);i++){
759 		if ((dev_select[i].selected != 0)
760 		 && (dev_select[i].selected <= maxshowdevs)) {
761 			if (oflag > 0) {
762 				if (Iflag == 0)
763 					(void)printf(" sps tps msps ");
764 				else
765 					(void)printf(" blk xfr msps ");
766 			} else {
767 				if (Iflag == 0)
768 					printf("KB/t   tps  MB/s ");
769 				else
770 					printf("KB/t  xfrs    MB ");
771 			}
772 			printed++;
773 		}
774 	}
775 	if (Cflag > 0)
776 		(void)printf(" us ni sy in id\n");
777 	else
778 		printf("\n");
779 
780 }
781 
782 static void
783 devstats(int perf_select, long double etime, int havelast)
784 {
785 	int dn;
786 	long double transfers_per_second, transfers_per_second_read;
787 	long double transfers_per_second_write;
788 	long double kb_per_transfer, mb_per_second, mb_per_second_read;
789 	long double mb_per_second_write;
790 	u_int64_t total_bytes, total_transfers, total_blocks;
791 	u_int64_t total_bytes_read, total_transfers_read;
792 	u_int64_t total_bytes_write, total_transfers_write;
793 	long double busy_pct, busy_time;
794 	u_int64_t queue_len;
795 	long double total_mb, blocks_per_second, total_duration;
796 	long double ms_per_other, ms_per_read, ms_per_write, ms_per_transaction;
797 	int firstline = 1;
798 	char *devicename;
799 
800 	if (xflag > 0) {
801 		if (Cflag > 0) {
802 			printf("      cpu\n");
803 			printf(" us ni sy in id\n");
804 			cpustats();
805 			printf("\n");
806 		}
807 		printf("                        extended device statistics  ");
808 		if (Tflag > 0)
809 			printf("      tty ");
810 		printf("\n");
811 		if (Iflag == 0) {
812 			printf("device       r/s     w/s     kr/s     kw/s "
813 			    " ms/r  ms/w  ms/o  ms/t qlen  %%b  ");
814 		} else {
815 			printf("device           r/i         w/i         kr/i"
816 			    "         kw/i qlen   tsvc_t/i      sb/i  ");
817 		}
818 		if (Tflag > 0)
819 			printf("tin  tout ");
820 		printf("\n");
821 	}
822 
823 	for (dn = 0; dn < num_devices; dn++) {
824 		int di;
825 
826 		if (((perf_select == 0) && (dev_select[dn].selected == 0))
827 		 || (dev_select[dn].selected > maxshowdevs))
828 			continue;
829 
830 		di = dev_select[dn].position;
831 
832 		if (devstat_compute_statistics(&cur.dinfo->devices[di],
833 		    havelast ? &last.dinfo->devices[di] : NULL, etime,
834 		    DSM_TOTAL_BYTES, &total_bytes,
835 		    DSM_TOTAL_BYTES_READ, &total_bytes_read,
836 		    DSM_TOTAL_BYTES_WRITE, &total_bytes_write,
837 		    DSM_TOTAL_TRANSFERS, &total_transfers,
838 		    DSM_TOTAL_TRANSFERS_READ, &total_transfers_read,
839 		    DSM_TOTAL_TRANSFERS_WRITE, &total_transfers_write,
840 		    DSM_TOTAL_BLOCKS, &total_blocks,
841 		    DSM_KB_PER_TRANSFER, &kb_per_transfer,
842 		    DSM_TRANSFERS_PER_SECOND, &transfers_per_second,
843 		    DSM_TRANSFERS_PER_SECOND_READ, &transfers_per_second_read,
844 		    DSM_TRANSFERS_PER_SECOND_WRITE, &transfers_per_second_write,
845 		    DSM_MB_PER_SECOND, &mb_per_second,
846 		    DSM_MB_PER_SECOND_READ, &mb_per_second_read,
847 		    DSM_MB_PER_SECOND_WRITE, &mb_per_second_write,
848 		    DSM_BLOCKS_PER_SECOND, &blocks_per_second,
849 		    DSM_MS_PER_TRANSACTION, &ms_per_transaction,
850 		    DSM_MS_PER_TRANSACTION_READ, &ms_per_read,
851 		    DSM_MS_PER_TRANSACTION_WRITE, &ms_per_write,
852 		    DSM_MS_PER_TRANSACTION_OTHER, &ms_per_other,
853 		    DSM_BUSY_PCT, &busy_pct,
854 		    DSM_QUEUE_LENGTH, &queue_len,
855 		    DSM_TOTAL_DURATION, &total_duration,
856 		    DSM_TOTAL_BUSY_TIME, &busy_time,
857 		    DSM_NONE) != 0)
858 			errx(1, "%s", devstat_errbuf);
859 
860 		if (perf_select != 0) {
861 			dev_select[dn].bytes = total_bytes;
862 			if ((dev_select[dn].selected == 0)
863 			 || (dev_select[dn].selected > maxshowdevs))
864 				continue;
865 		}
866 
867 		if (Kflag > 0 || xflag > 0) {
868 			int block_size = cur.dinfo->devices[di].block_size;
869 			total_blocks = total_blocks * (block_size ?
870 						       block_size : 512) / 1024;
871 		}
872 
873 		if (xflag > 0) {
874 			if (asprintf(&devicename, "%s%d",
875 			    cur.dinfo->devices[di].device_name,
876 			    cur.dinfo->devices[di].unit_number) == -1)
877 				err(1, "asprintf");
878 			/*
879 			 * If zflag is set, skip any devices with zero I/O.
880 			 */
881 			if (zflag == 0 || transfers_per_second_read > 0.05 ||
882 			    transfers_per_second_write > 0.05 ||
883 			    mb_per_second_read > ((long double).0005)/1024 ||
884 			    mb_per_second_write > ((long double).0005)/1024 ||
885 			    busy_pct > 0.5) {
886 				if (Iflag == 0)
887 					printf("%-8.8s %7.0Lf %7.0Lf %8.1Lf "
888 					    "%8.1Lf %5.0Lf %5.0Lf %5.0Lf %5.0Lf"
889 					    " %4" PRIu64 " %3.0Lf ",
890 					    devicename,
891 					    transfers_per_second_read,
892 					    transfers_per_second_write,
893 					    mb_per_second_read * 1024,
894 					    mb_per_second_write * 1024,
895 					    ms_per_read, ms_per_write,
896 					    ms_per_other,
897 					    ms_per_transaction,
898 					    queue_len, busy_pct);
899 				else
900 					printf("%-8.8s %11.1Lf %11.1Lf "
901 					    "%12.1Lf %12.1Lf %4" PRIu64
902 					    " %10.1Lf %9.1Lf ",
903 					    devicename,
904 					    (long double)total_transfers_read,
905 					    (long double)total_transfers_write,
906 					    (long double)
907 					        total_bytes_read / 1024,
908 					    (long double)
909 					        total_bytes_write / 1024,
910 					    queue_len,
911 					    total_duration, busy_time);
912 				if (firstline) {
913 					/*
914 					 * If this is the first device
915 					 * we're printing, also print
916 					 * CPU or TTY stats if requested.
917 					 */
918 					firstline = 0;
919 					if (Tflag > 0)
920 						printf("%4.0Lf%5.0Lf",
921 						    cur.tk_nin / etime,
922 						    cur.tk_nout / etime);
923 				}
924 				printf("\n");
925 			}
926 			free(devicename);
927 		} else if (oflag > 0) {
928 			int msdig = (ms_per_transaction < 99.94) ? 1 : 0;
929 
930 			if (Iflag == 0)
931 				printf("%4.0Lf%4.0Lf%5.*Lf ",
932 				       blocks_per_second,
933 				       transfers_per_second,
934 				       msdig,
935 				       ms_per_transaction);
936 			else
937 				printf("%4" PRIu64 "%4" PRIu64 "%5.*Lf ",
938 				       total_blocks,
939 				       total_transfers,
940 				       msdig,
941 				       ms_per_transaction);
942 		} else {
943 			if (Iflag == 0)
944 				printf("%4.*Lf %5.0Lf %5.*Lf ",
945 				       kb_per_transfer >= 100 ? 0 : 1,
946 				       kb_per_transfer,
947 				       transfers_per_second,
948 				       mb_per_second >= 1000 ? 0 :
949 					(total_mb >= 100 ? 1 : 2),
950 				       mb_per_second);
951 			else {
952 				total_mb = total_bytes;
953 				total_mb /= 1024 * 1024;
954 
955 				printf("%4.*Lf %5" PRIu64 " %5.*Lf ",
956 				       kb_per_transfer >= 100 ? 0 : 1,
957 				       kb_per_transfer,
958 				       total_transfers,
959 				       total_mb >= 1000 ? 0 :
960 					(total_mb >= 100 ? 1 : 2),
961 				       total_mb);
962 			}
963 		}
964 	}
965 	if (xflag > 0 && zflag > 0 && firstline == 1 &&
966 	    (Tflag > 0 || Cflag > 0)) {
967 		/*
968 		 * If zflag is set and we did not print any device
969 		 * lines I/O because they were all zero,
970 		 * print TTY/CPU stats.
971 		 */
972 		printf("%52s","");
973 		if (Tflag > 0)
974 			printf("%4.0Lf %5.0Lf", cur.tk_nin / etime,
975 			    cur.tk_nout / etime);
976 		if (Cflag > 0)
977 			cpustats();
978 		printf("\n");
979 	}
980 }
981 
982 static void
983 cpustats(void)
984 {
985 	int state;
986 	double cptime;
987 
988 	cptime = 0.0;
989 
990 	for (state = 0; state < CPUSTATES; ++state)
991 		cptime += cur.cp_time[state];
992 	for (state = 0; state < CPUSTATES; ++state)
993 		printf(" %2.0f",
994 		       rint(100. * cur.cp_time[state] / (cptime ? cptime : 1)));
995 }
996 
997 static int
998 readvar(kvm_t *kd, const char *name, int nlid, void *ptr, size_t len)
999 {
1000 	if (kd != NULL) {
1001 		ssize_t nbytes;
1002 
1003 		nbytes = kvm_read(kd, namelist[nlid].n_value, ptr, len);
1004 
1005 		if (nbytes < 0) {
1006 			warnx("kvm_read(%s): %s", namelist[nlid].n_name,
1007 			    kvm_geterr(kd));
1008 			return (1);
1009 		} else if ((size_t)nbytes != len) {
1010 			warnx("kvm_read(%s): expected %zu bytes, got %zd bytes",
1011 			      namelist[nlid].n_name, len, nbytes);
1012 			return (1);
1013 		}
1014 	} else {
1015 		size_t nlen = len;
1016 
1017 		if (sysctlbyname(name, ptr, &nlen, NULL, 0) == -1) {
1018 			warn("sysctl(%s...) failed", name);
1019 			return (1);
1020 		}
1021 		if (nlen != len) {
1022 			warnx("sysctl(%s...): expected %lu, got %lu", name,
1023 			      (unsigned long)len, (unsigned long)nlen);
1024 			return (1);
1025 		}
1026 	}
1027 	return (0);
1028 }
1029