xref: /freebsd/usr.sbin/iostat/iostat.c (revision ab40f58ccfe6c07ebefddc72f4661a52fe746353)
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  * $FreeBSD$
31  */
32 /*
33  * Parts of this program are derived from the original FreeBSD iostat
34  * program:
35  */
36 /*-
37  * Copyright (c) 1986, 1991, 1993
38  *	The Regents of the University of California.  All rights reserved.
39  *
40  * Redistribution and use in source and binary forms, with or without
41  * modification, are permitted provided that the following conditions
42  * are met:
43  * 1. Redistributions of source code must retain the above copyright
44  *    notice, this list of conditions and the following disclaimer.
45  * 2. Redistributions in binary form must reproduce the above copyright
46  *    notice, this list of conditions and the following disclaimer in the
47  *    documentation and/or other materials provided with the distribution.
48  * 4. Neither the name of the University nor the names of its contributors
49  *    may be used to endorse or promote products derived from this software
50  *    without specific prior written permission.
51  *
52  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
53  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
55  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
56  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
57  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
58  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
60  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
61  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
62  * SUCH DAMAGE.
63  */
64 /*
65  * Ideas for the new iostat statistics output modes taken from the NetBSD
66  * version of iostat:
67  */
68 /*
69  * Copyright (c) 1996 John M. Vinopal
70  * All rights reserved.
71  *
72  * Redistribution and use in source and binary forms, with or without
73  * modification, are permitted provided that the following conditions
74  * are met:
75  * 1. Redistributions of source code must retain the above copyright
76  *    notice, this list of conditions and the following disclaimer.
77  * 2. Redistributions in binary form must reproduce the above copyright
78  *    notice, this list of conditions and the following disclaimer in the
79  *    documentation and/or other materials provided with the distribution.
80  * 3. All advertising materials mentioning features or use of this software
81  *    must display the following acknowledgement:
82  *      This product includes software developed for the NetBSD Project
83  *      by John M. Vinopal.
84  * 4. The name of the author may not be used to endorse or promote products
85  *    derived from this software without specific prior written permission.
86  *
87  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
88  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
89  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
90  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
91  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
92  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
93  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
94  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
95  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
96  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
97  * SUCH DAMAGE.
98  */
99 
100 
101 #include <sys/param.h>
102 #include <sys/errno.h>
103 #include <sys/resource.h>
104 #include <sys/sysctl.h>
105 
106 #include <ctype.h>
107 #include <devstat.h>
108 #include <err.h>
109 #include <fcntl.h>
110 #include <inttypes.h>
111 #include <kvm.h>
112 #include <limits.h>
113 #include <math.h>
114 #include <nlist.h>
115 #include <signal.h>
116 #include <stdio.h>
117 #include <stdlib.h>
118 #include <string.h>
119 #include <termios.h>
120 #include <unistd.h>
121 
122 static struct nlist namelist[] = {
123 #define X_TTY_NIN	0
124 	{ .n_name = "_tty_nin",
125 	  .n_type = 0, .n_other = 0, .n_desc = 0, .n_value = 0 },
126 #define X_TTY_NOUT	1
127 	{ .n_name = "_tty_nout",
128 	  .n_type = 0, .n_other = 0, .n_desc = 0, .n_value = 0 },
129 #define X_BOOTTIME	2
130 	{ .n_name = "_boottime",
131 	  .n_type = 0, .n_other = 0, .n_desc = 0, .n_value = 0 },
132 #define X_END		2
133 	{ .n_name = NULL,
134 	  .n_type = 0, .n_other = 0, .n_desc = 0, .n_value = 0 },
135 };
136 
137 #define	IOSTAT_DEFAULT_ROWS	20	/* Traditional default `wrows' */
138 
139 static struct statinfo cur, last;
140 static int num_devices;
141 static struct device_selection *dev_select;
142 static int maxshowdevs;
143 static volatile sig_atomic_t headercount;
144 static volatile sig_atomic_t wresized;	/* Tty resized, when non-zero. */
145 static volatile sig_atomic_t alarm_rang;
146 static volatile sig_atomic_t return_requested;
147 static unsigned short wrows;		/* Current number of tty rows. */
148 static int dflag = 0, Iflag = 0, Cflag = 0, Tflag = 0, oflag = 0, Kflag = 0;
149 static int xflag = 0, zflag = 0;
150 
151 /* local function declarations */
152 static void usage(void);
153 static void needhdr(int signo);
154 static void needresize(int signo);
155 static void needreturn(int signo);
156 static void alarm_clock(int signo);
157 static void doresize(void);
158 static void phdr(void);
159 static void devstats(int perf_select, long double etime, int havelast);
160 static void cpustats(void);
161 static int readvar(kvm_t *kd, const char *name, int nlid, void *ptr,
162 		   size_t len);
163 
164 static void
165 usage(void)
166 {
167 	/*
168 	 * We also support the following 'traditional' syntax:
169 	 * iostat [drives] [wait [count]]
170 	 * This isn't mentioned in the man page, or the usage statement,
171 	 * but it is supported.
172 	 */
173 	fprintf(stderr, "usage: iostat [-CdhIKoTxz?] [-c count] [-M core]"
174 		" [-n devs] [-N system]\n"
175 		"\t      [-t type,if,pass] [-w wait] [drives]\n");
176 }
177 
178 int
179 main(int argc, char **argv)
180 {
181 	int c, i;
182 	int tflag = 0, hflag = 0, cflag = 0, wflag = 0, nflag = 0;
183 	int count = 0, waittime = 0;
184 	char *memf = NULL, *nlistf = NULL;
185 	struct devstat_match *matches;
186 	struct itimerval alarmspec;
187 	int num_matches = 0;
188 	char errbuf[_POSIX2_LINE_MAX];
189 	kvm_t *kd = NULL;
190 	long generation;
191 	int num_devices_specified;
192 	int num_selected, num_selections;
193 	long select_generation;
194 	char **specified_devices;
195 	devstat_select_mode select_mode;
196 	float f;
197 	int havelast = 0;
198 
199 	matches = NULL;
200 	maxshowdevs = 3;
201 
202 	while ((c = getopt(argc, argv, "c:CdhIKM:n:N:ot:Tw:xz?")) != -1) {
203 		switch(c) {
204 			case 'c':
205 				cflag++;
206 				count = atoi(optarg);
207 				if (count < 1)
208 					errx(1, "count %d is < 1", count);
209 				break;
210 			case 'C':
211 				Cflag++;
212 				break;
213 			case 'd':
214 				dflag++;
215 				break;
216 			case 'h':
217 				hflag++;
218 				break;
219 			case 'I':
220 				Iflag++;
221 				break;
222 			case 'K':
223 				Kflag++;
224 				break;
225 			case 'M':
226 				memf = optarg;
227 				break;
228 			case 'n':
229 				nflag++;
230 				maxshowdevs = atoi(optarg);
231 				if (maxshowdevs < 0)
232 					errx(1, "number of devices %d is < 0",
233 					     maxshowdevs);
234 				break;
235 			case 'N':
236 				nlistf = optarg;
237 				break;
238 			case 'o':
239 				oflag++;
240 				break;
241 			case 't':
242 				tflag++;
243 				if (devstat_buildmatch(optarg, &matches,
244 						       &num_matches) != 0)
245 					errx(1, "%s", devstat_errbuf);
246 				break;
247 			case 'T':
248 				Tflag++;
249 				break;
250 			case 'w':
251 				wflag++;
252 				f = atof(optarg);
253 				waittime = f * 1000;
254 				if (waittime < 1)
255 					errx(1, "wait time is < 1ms");
256 				break;
257 			case 'x':
258 				xflag++;
259 				break;
260 			case 'z':
261 				zflag++;
262 				break;
263 			default:
264 				usage();
265 				exit(1);
266 				break;
267 		}
268 	}
269 
270 	argc -= optind;
271 	argv += optind;
272 
273 	if (nlistf != NULL || memf != NULL) {
274 		kd = kvm_openfiles(nlistf, memf, NULL, O_RDONLY, errbuf);
275 
276 		if (kd == NULL)
277 			errx(1, "kvm_openfiles: %s", errbuf);
278 
279 		if (kvm_nlist(kd, namelist) == -1)
280 			errx(1, "kvm_nlist: %s", kvm_geterr(kd));
281 	}
282 
283 	/*
284 	 * Make sure that the userland devstat version matches the kernel
285 	 * devstat version.  If not, exit and print a message informing
286 	 * the user of his mistake.
287 	 */
288 	if (devstat_checkversion(kd) < 0)
289 		errx(1, "%s", devstat_errbuf);
290 
291 	/*
292 	 * Make sure Tflag and/or Cflag are set if dflag == 0.  If dflag is
293 	 * greater than 0, they may be 0 or non-zero.
294 	 */
295 	if (dflag == 0 && xflag == 0) {
296 		Cflag = 1;
297 		Tflag = 1;
298 	}
299 
300 	/* find out how many devices we have */
301 	if ((num_devices = devstat_getnumdevs(kd)) < 0)
302 		err(1, "can't get number of devices");
303 
304 	/*
305 	 * Figure out how many devices we should display.
306 	 */
307 	if (nflag == 0) {
308 		if (xflag > 0)
309 			maxshowdevs = num_devices;
310 		else if (oflag > 0) {
311 			if ((dflag > 0) && (Cflag == 0) && (Tflag == 0))
312 				maxshowdevs = 5;
313 			else if ((dflag > 0) && (Tflag > 0) && (Cflag == 0))
314 				maxshowdevs = 5;
315 			else
316 				maxshowdevs = 4;
317 		} else {
318 			if ((dflag > 0) && (Cflag == 0))
319 				maxshowdevs = 4;
320 			else
321 				maxshowdevs = 3;
322 		}
323 	}
324 
325 	cur.dinfo = (struct devinfo *)calloc(1, sizeof(struct devinfo));
326 	if (cur.dinfo == NULL)
327 		err(1, "calloc failed");
328 
329 	last.dinfo = (struct devinfo *)calloc(1, sizeof(struct devinfo));
330 	if (last.dinfo == NULL)
331 		err(1, "calloc failed");
332 
333 	/*
334 	 * Grab all the devices.  We don't look to see if the list has
335 	 * changed here, since it almost certainly has.  We only look for
336 	 * errors.
337 	 */
338 	if (devstat_getdevs(kd, &cur) == -1)
339 		errx(1, "%s", devstat_errbuf);
340 
341 	num_devices = cur.dinfo->numdevs;
342 	generation = cur.dinfo->generation;
343 
344 	/*
345 	 * If the user specified any devices on the command line, see if
346 	 * they are in the list of devices we have now.
347 	 */
348 	specified_devices = (char **)malloc(sizeof(char *));
349 	if (specified_devices == NULL)
350 		err(1, "malloc failed");
351 
352 	for (num_devices_specified = 0; *argv; ++argv) {
353 		if (isdigit(**argv))
354 			break;
355 		num_devices_specified++;
356 		specified_devices = (char **)realloc(specified_devices,
357 						     sizeof(char *) *
358 						     num_devices_specified);
359 		if (specified_devices == NULL)
360 			err(1, "realloc failed");
361 
362 		specified_devices[num_devices_specified - 1] = *argv;
363 
364 	}
365 	if (nflag == 0 && maxshowdevs < num_devices_specified)
366 		maxshowdevs = num_devices_specified;
367 
368 	dev_select = NULL;
369 
370 	if ((num_devices_specified == 0) && (num_matches == 0))
371 		select_mode = DS_SELECT_ADD;
372 	else
373 		select_mode = DS_SELECT_ONLY;
374 
375 	/*
376 	 * At this point, selectdevs will almost surely indicate that the
377 	 * device list has changed, so we don't look for return values of 0
378 	 * or 1.  If we get back -1, though, there is an error.
379 	 */
380 	if (devstat_selectdevs(&dev_select, &num_selected,
381 			       &num_selections, &select_generation, generation,
382 			       cur.dinfo->devices, num_devices, matches,
383 			       num_matches, specified_devices,
384 			       num_devices_specified, select_mode, maxshowdevs,
385 			       hflag) == -1)
386 		errx(1, "%s", devstat_errbuf);
387 
388 	/*
389 	 * Look for the traditional wait time and count arguments.
390 	 */
391 	if (*argv) {
392 		f = atof(*argv);
393 		waittime = f * 1000;
394 
395 		/* Let the user know he goofed, but keep going anyway */
396 		if (wflag != 0)
397 			warnx("discarding previous wait interval, using"
398 			      " %g instead", waittime / 1000.0);
399 		wflag++;
400 
401 		if (*++argv) {
402 			count = atoi(*argv);
403 			if (cflag != 0)
404 				warnx("discarding previous count, using %d"
405 				      " instead", count);
406 			cflag++;
407 		} else
408 			count = -1;
409 	}
410 
411 	/*
412 	 * If the user specified a count, but not an interval, we default
413 	 * to an interval of 1 second.
414 	 */
415 	if ((wflag == 0) && (cflag > 0))
416 		waittime = 1 * 1000;
417 
418 	/*
419 	 * If the user specified a wait time, but not a count, we want to
420 	 * go on ad infinitum.  This can be redundant if the user uses the
421 	 * traditional method of specifying the wait, since in that case we
422 	 * already set count = -1 above.  Oh well.
423 	 */
424 	if ((wflag > 0) && (cflag == 0))
425 		count = -1;
426 
427 	bzero(cur.cp_time, sizeof(cur.cp_time));
428 	cur.tk_nout = 0;
429 	cur.tk_nin = 0;
430 
431 	/*
432 	 * Set the snap time to the system boot time (ie: zero), so the
433 	 * stats are calculated since system boot.
434 	 */
435 	cur.snap_time = 0;
436 
437 	/*
438 	 * If the user stops the program (control-Z) and then resumes it,
439 	 * print out the header again.
440 	 */
441 	(void)signal(SIGCONT, needhdr);
442 
443 	/*
444 	 * If our standard output is a tty, then install a SIGWINCH handler
445 	 * and set wresized so that our first iteration through the main
446 	 * iostat loop will peek at the terminal's current rows to find out
447 	 * how many lines can fit in a screenful of output.
448 	 */
449 	if (isatty(fileno(stdout)) != 0) {
450 		wresized = 1;
451 		(void)signal(SIGWINCH, needresize);
452 	} else {
453 		wresized = 0;
454 		wrows = IOSTAT_DEFAULT_ROWS;
455 	}
456 
457 	/*
458 	 * Register a SIGINT handler so that we can print out final statistics
459 	 * when we get that signal
460 	 */
461 	(void)signal(SIGINT, needreturn);
462 
463 	/*
464 	 * Register a SIGALRM handler to implement sleeps if the user uses the
465 	 * -c or -w options
466 	 */
467 	(void)signal(SIGALRM, alarm_clock);
468 	alarmspec.it_interval.tv_sec = waittime / 1000;
469 	alarmspec.it_interval.tv_usec = 1000 * (waittime % 1000);
470 	alarmspec.it_value.tv_sec = waittime / 1000;
471 	alarmspec.it_value.tv_usec = 1000 * (waittime % 1000);
472 	setitimer(ITIMER_REAL, &alarmspec, NULL);
473 
474 	for (headercount = 1;;) {
475 		struct devinfo *tmp_dinfo;
476 		long tmp;
477 		long double etime;
478 		sigset_t sigmask, oldsigmask;
479 
480 		if (Tflag > 0) {
481 			if ((readvar(kd, "kern.tty_nin", X_TTY_NIN, &cur.tk_nin,
482 			     sizeof(cur.tk_nin)) != 0)
483 			 || (readvar(kd, "kern.tty_nout", X_TTY_NOUT,
484 			     &cur.tk_nout, sizeof(cur.tk_nout))!= 0)) {
485 				Tflag = 0;
486 				warnx("disabling TTY statistics");
487 			}
488 		 }
489 
490 		if (Cflag > 0) {
491 			if (kd == NULL) {
492 				if (readvar(kd, "kern.cp_time", 0,
493 				    &cur.cp_time, sizeof(cur.cp_time)) != 0)
494 					Cflag = 0;
495 			} else {
496 				if (kvm_getcptime(kd, cur.cp_time) < 0) {
497 					warnx("kvm_getcptime: %s",
498 					    kvm_geterr(kd));
499 					Cflag = 0;
500 				}
501 			}
502 			if (Cflag == 0)
503 				warnx("disabling CPU time statistics");
504 		}
505 
506 		if (!--headercount) {
507 			phdr();
508 			if (wresized != 0)
509 				doresize();
510 			headercount = wrows;
511 		}
512 
513 		tmp_dinfo = last.dinfo;
514 		last.dinfo = cur.dinfo;
515 		cur.dinfo = tmp_dinfo;
516 
517 		last.snap_time = cur.snap_time;
518 
519 		/*
520 		 * Here what we want to do is refresh our device stats.
521 		 * devstat_getdevs() returns 1 when the device list has changed.
522 		 * If the device list has changed, we want to go through
523 		 * the selection process again, in case a device that we
524 		 * were previously displaying has gone away.
525 		 */
526 		switch (devstat_getdevs(kd, &cur)) {
527 		case -1:
528 			errx(1, "%s", devstat_errbuf);
529 			break;
530 		case 1: {
531 			int retval;
532 
533 			num_devices = cur.dinfo->numdevs;
534 			generation = cur.dinfo->generation;
535 			retval = devstat_selectdevs(&dev_select, &num_selected,
536 						    &num_selections,
537 						    &select_generation,
538 						    generation,
539 						    cur.dinfo->devices,
540 						    num_devices, matches,
541 						    num_matches,
542 						    specified_devices,
543 						    num_devices_specified,
544 						    select_mode, maxshowdevs,
545 						    hflag);
546 			switch(retval) {
547 			case -1:
548 				errx(1, "%s", devstat_errbuf);
549 				break;
550 			case 1:
551 				phdr();
552 				if (wresized != 0)
553 					doresize();
554 				headercount = wrows;
555 				break;
556 			default:
557 				break;
558 			}
559 			break;
560 		}
561 		default:
562 			break;
563 		}
564 
565 		/*
566 		 * We only want to re-select devices if we're in 'top'
567 		 * mode.  This is the only mode where the devices selected
568 		 * could actually change.
569 		 */
570 		if (hflag > 0) {
571 			int retval;
572 			retval = devstat_selectdevs(&dev_select, &num_selected,
573 						    &num_selections,
574 						    &select_generation,
575 						    generation,
576 						    cur.dinfo->devices,
577 						    num_devices, matches,
578 						    num_matches,
579 						    specified_devices,
580 						    num_devices_specified,
581 						    select_mode, maxshowdevs,
582 						    hflag);
583 			switch(retval) {
584 			case -1:
585 				errx(1,"%s", devstat_errbuf);
586 				break;
587 			case 1:
588 				phdr();
589 				if (wresized != 0)
590 					doresize();
591 				headercount = wrows;
592 				break;
593 			default:
594 				break;
595 			}
596 		}
597 
598 		if (Tflag > 0) {
599 			tmp = cur.tk_nin;
600 			cur.tk_nin -= last.tk_nin;
601 			last.tk_nin = tmp;
602 			tmp = cur.tk_nout;
603 			cur.tk_nout -= last.tk_nout;
604 			last.tk_nout = tmp;
605 		}
606 
607 		etime = cur.snap_time - last.snap_time;
608 
609 		if (etime == 0.0)
610 			etime = 1.0;
611 
612 		for (i = 0; i < CPUSTATES; i++) {
613 			tmp = cur.cp_time[i];
614 			cur.cp_time[i] -= last.cp_time[i];
615 			last.cp_time[i] = tmp;
616 		}
617 
618 		if (xflag == 0 && Tflag > 0)
619 			printf("%4.0Lf %5.0Lf", cur.tk_nin / etime,
620 			    cur.tk_nout / etime);
621 
622 		devstats(hflag, etime, havelast);
623 
624 		if (xflag == 0) {
625 			if (Cflag > 0)
626 				cpustats();
627 
628 			printf("\n");
629 		}
630 		fflush(stdout);
631 
632 		if ((count >= 0 && --count <= 0) || return_requested)
633 			break;
634 
635 		/*
636 		 * Use sigsuspend to safely sleep until either signal is
637 		 * received
638 		 */
639 		alarm_rang = 0;
640 		sigemptyset(&sigmask);
641 		sigaddset(&sigmask, SIGINT);
642 		sigaddset(&sigmask, SIGALRM);
643 		sigprocmask(SIG_BLOCK, &sigmask, &oldsigmask);
644 		while (! (alarm_rang || return_requested) ) {
645 			sigsuspend(&oldsigmask);
646 		}
647 		sigprocmask(SIG_UNBLOCK, &sigmask, NULL);
648 
649 		havelast = 1;
650 	}
651 
652 	exit(0);
653 }
654 
655 /*
656  * Force a header to be prepended to the next output.
657  */
658 void
659 needhdr(int signo __unused)
660 {
661 
662 	headercount = 1;
663 }
664 
665 /*
666  * When the terminal is resized, force an update of the maximum number of rows
667  * printed between each header repetition.  Then force a new header to be
668  * prepended to the next output.
669  */
670 void
671 needresize(int signo __unused)
672 {
673 
674 	wresized = 1;
675 	headercount = 1;
676 }
677 
678 /*
679  * Record the alarm so the main loop can break its sleep
680  */
681 void
682 alarm_clock(int signo __unused)
683 {
684 	alarm_rang = 1;
685 }
686 
687 /*
688  * Request that the main loop exit soon
689  */
690 void
691 needreturn(int signo __unused)
692 {
693 	return_requested = 1;
694 }
695 
696 /*
697  * Update the global `wrows' count of terminal rows.
698  */
699 void
700 doresize(void)
701 {
702 	int status;
703 	struct winsize w;
704 
705 	for (;;) {
706 		status = ioctl(fileno(stdout), TIOCGWINSZ, &w);
707 		if (status == -1 && errno == EINTR)
708 			continue;
709 		else if (status == -1)
710 			err(1, "ioctl");
711 		if (w.ws_row > 3)
712 			wrows = w.ws_row - 3;
713 		else
714 			wrows = IOSTAT_DEFAULT_ROWS;
715 		break;
716 	}
717 
718 	/*
719 	 * Inhibit doresize() calls until we are rescheduled by SIGWINCH.
720 	 */
721 	wresized = 0;
722 }
723 
724 static void
725 phdr(void)
726 {
727 	int i, printed;
728 	char devbuf[256];
729 
730 	/*
731 	 * If xflag is set, we need a per-loop header, not a page header, so
732 	 * just return.  We'll print the header in devstats().
733 	 */
734 	if (xflag > 0)
735 		return;
736 
737 	if (Tflag > 0)
738 		(void)printf("       tty");
739 	for (i = 0, printed=0;(i < num_devices) && (printed < maxshowdevs);i++){
740 		int di;
741 		if ((dev_select[i].selected != 0)
742 		 && (dev_select[i].selected <= maxshowdevs)) {
743 			di = dev_select[i].position;
744 			snprintf(devbuf, sizeof(devbuf), "%s%d",
745 					    cur.dinfo->devices[di].device_name,
746 					    cur.dinfo->devices[di].unit_number);
747 			if (oflag > 0)
748 				(void)printf("%13.6s ", devbuf);
749 			else
750 				printf("%16.6s ", devbuf);
751 			printed++;
752 		}
753 	}
754 	if (Cflag > 0)
755 		(void)printf("            cpu\n");
756 	else
757 		(void)printf("\n");
758 
759 	if (Tflag > 0)
760 		(void)printf(" tin  tout");
761 
762 	for (i=0, printed = 0;(i < num_devices) && (printed < maxshowdevs);i++){
763 		if ((dev_select[i].selected != 0)
764 		 && (dev_select[i].selected <= maxshowdevs)) {
765 			if (oflag > 0) {
766 				if (Iflag == 0)
767 					(void)printf(" sps tps msps ");
768 				else
769 					(void)printf(" blk xfr msps ");
770 			} else {
771 				if (Iflag == 0)
772 					printf("  KB/t tps  MB/s ");
773 				else
774 					printf("  KB/t xfrs   MB ");
775 			}
776 			printed++;
777 		}
778 	}
779 	if (Cflag > 0)
780 		(void)printf(" us ni sy in id\n");
781 	else
782 		printf("\n");
783 
784 }
785 
786 static void
787 devstats(int perf_select, long double etime, int havelast)
788 {
789 	int dn;
790 	long double transfers_per_second, transfers_per_second_read;
791 	long double transfers_per_second_write;
792 	long double kb_per_transfer, mb_per_second, mb_per_second_read;
793 	long double mb_per_second_write;
794 	u_int64_t total_bytes, total_transfers, total_blocks;
795 	u_int64_t total_bytes_read, total_transfers_read;
796 	u_int64_t total_bytes_write, total_transfers_write;
797 	long double busy_pct, busy_time;
798 	u_int64_t queue_len;
799 	long double total_mb, blocks_per_second, total_duration;
800 	long double ms_per_other, ms_per_read, ms_per_write, ms_per_transaction;
801 	int firstline = 1;
802 	char *devicename;
803 
804 	if (xflag > 0) {
805 		if (Cflag > 0) {
806 			printf("      cpu\n");
807 			printf(" us ni sy in id\n");
808 			cpustats();
809 			printf("\n");
810 		}
811 		printf("                        extended device statistics  ");
812 		if (Tflag > 0)
813 			printf("      tty ");
814 		printf("\n");
815 		if (Iflag == 0) {
816 			printf("device       r/s     w/s     kr/s     kw/s "
817 			    " ms/r  ms/w  ms/o  ms/t qlen  %%b  ");
818 		} else {
819 			printf("device           r/i         w/i         kr/i"
820 			    "         kw/i qlen   tsvc_t/i      sb/i  ");
821 		}
822 		if (Tflag > 0)
823 			printf("tin  tout ");
824 		printf("\n");
825 	}
826 
827 	for (dn = 0; dn < num_devices; dn++) {
828 		int di;
829 
830 		if (((perf_select == 0) && (dev_select[dn].selected == 0))
831 		 || (dev_select[dn].selected > maxshowdevs))
832 			continue;
833 
834 		di = dev_select[dn].position;
835 
836 		if (devstat_compute_statistics(&cur.dinfo->devices[di],
837 		    havelast ? &last.dinfo->devices[di] : NULL, etime,
838 		    DSM_TOTAL_BYTES, &total_bytes,
839 		    DSM_TOTAL_BYTES_READ, &total_bytes_read,
840 		    DSM_TOTAL_BYTES_WRITE, &total_bytes_write,
841 		    DSM_TOTAL_TRANSFERS, &total_transfers,
842 		    DSM_TOTAL_TRANSFERS_READ, &total_transfers_read,
843 		    DSM_TOTAL_TRANSFERS_WRITE, &total_transfers_write,
844 		    DSM_TOTAL_BLOCKS, &total_blocks,
845 		    DSM_KB_PER_TRANSFER, &kb_per_transfer,
846 		    DSM_TRANSFERS_PER_SECOND, &transfers_per_second,
847 		    DSM_TRANSFERS_PER_SECOND_READ, &transfers_per_second_read,
848 		    DSM_TRANSFERS_PER_SECOND_WRITE, &transfers_per_second_write,
849 		    DSM_MB_PER_SECOND, &mb_per_second,
850 		    DSM_MB_PER_SECOND_READ, &mb_per_second_read,
851 		    DSM_MB_PER_SECOND_WRITE, &mb_per_second_write,
852 		    DSM_BLOCKS_PER_SECOND, &blocks_per_second,
853 		    DSM_MS_PER_TRANSACTION, &ms_per_transaction,
854 		    DSM_MS_PER_TRANSACTION_READ, &ms_per_read,
855 		    DSM_MS_PER_TRANSACTION_WRITE, &ms_per_write,
856 		    DSM_MS_PER_TRANSACTION_OTHER, &ms_per_other,
857 		    DSM_BUSY_PCT, &busy_pct,
858 		    DSM_QUEUE_LENGTH, &queue_len,
859 		    DSM_TOTAL_DURATION, &total_duration,
860 		    DSM_TOTAL_BUSY_TIME, &busy_time,
861 		    DSM_NONE) != 0)
862 			errx(1, "%s", devstat_errbuf);
863 
864 		if (perf_select != 0) {
865 			dev_select[dn].bytes = total_bytes;
866 			if ((dev_select[dn].selected == 0)
867 			 || (dev_select[dn].selected > maxshowdevs))
868 				continue;
869 		}
870 
871 		if (Kflag > 0 || xflag > 0) {
872 			int block_size = cur.dinfo->devices[di].block_size;
873 			total_blocks = total_blocks * (block_size ?
874 						       block_size : 512) / 1024;
875 		}
876 
877 		if (xflag > 0) {
878 			if (asprintf(&devicename, "%s%d",
879 			    cur.dinfo->devices[di].device_name,
880 			    cur.dinfo->devices[di].unit_number) == -1)
881 				err(1, "asprintf");
882 			/*
883 			 * If zflag is set, skip any devices with zero I/O.
884 			 */
885 			if (zflag == 0 || transfers_per_second_read > 0.05 ||
886 			    transfers_per_second_write > 0.05 ||
887 			    mb_per_second_read > ((long double).0005)/1024 ||
888 			    mb_per_second_write > ((long double).0005)/1024 ||
889 			    busy_pct > 0.5) {
890 				if (Iflag == 0)
891 					printf("%-8.8s %7d %7d %8.1Lf "
892 					    "%8.1Lf %5d %5d %5d %5d "
893 					    "%4" PRIu64 " %3.0Lf ",
894 					    devicename,
895 					    (int)transfers_per_second_read,
896 					    (int)transfers_per_second_write,
897 					    mb_per_second_read * 1024,
898 					    mb_per_second_write * 1024,
899 					    (int)ms_per_read, (int)ms_per_write,
900 					    (int)ms_per_other,
901 					    (int)ms_per_transaction,
902 					    queue_len, busy_pct);
903 				else
904 					printf("%-8.8s %11.1Lf %11.1Lf "
905 					    "%12.1Lf %12.1Lf %4" PRIu64
906 					    " %10.1Lf %9.1Lf ",
907 					    devicename,
908 					    (long double)total_transfers_read,
909 					    (long double)total_transfers_write,
910 					    (long double)
911 					        total_bytes_read / 1024,
912 					    (long double)
913 					        total_bytes_write / 1024,
914 					    queue_len,
915 					    total_duration, busy_time);
916 				if (firstline) {
917 					/*
918 					 * If this is the first device
919 					 * we're printing, also print
920 					 * CPU or TTY stats if requested.
921 					 */
922 					firstline = 0;
923 					if (Tflag > 0)
924 						printf("%4.0Lf%5.0Lf",
925 						    cur.tk_nin / etime,
926 						    cur.tk_nout / etime);
927 				}
928 				printf("\n");
929 			}
930 			free(devicename);
931 		} else if (oflag > 0) {
932 			int msdig = (ms_per_transaction < 100.0) ? 1 : 0;
933 
934 			if (Iflag == 0)
935 				printf("%4.0Lf%4.0Lf%5.*Lf ",
936 				       blocks_per_second,
937 				       transfers_per_second,
938 				       msdig,
939 				       ms_per_transaction);
940 			else
941 				printf("%4.1" PRIu64 "%4.1" PRIu64 "%5.*Lf ",
942 				       total_blocks,
943 				       total_transfers,
944 				       msdig,
945 				       ms_per_transaction);
946 		} else {
947 			if (Iflag == 0)
948 				printf(" %5.2Lf %3.0Lf %5.2Lf ",
949 				       kb_per_transfer,
950 				       transfers_per_second,
951 				       mb_per_second);
952 			else {
953 				total_mb = total_bytes;
954 				total_mb /= 1024 * 1024;
955 
956 				printf(" %5.2Lf %3.1" PRIu64 " %5.2Lf ",
957 				       kb_per_transfer,
958 				       total_transfers,
959 				       total_mb);
960 			}
961 		}
962 	}
963 	if (xflag > 0 && zflag > 0 && firstline == 1 &&
964 	    (Tflag > 0 || Cflag > 0)) {
965 		/*
966 		 * If zflag is set and we did not print any device
967 		 * lines I/O because they were all zero,
968 		 * print TTY/CPU stats.
969 		 */
970 		printf("%52s","");
971 		if (Tflag > 0)
972 			printf("%4.0Lf %5.0Lf", cur.tk_nin / etime,
973 			    cur.tk_nout / etime);
974 		if (Cflag > 0)
975 			cpustats();
976 		printf("\n");
977 	}
978 }
979 
980 static void
981 cpustats(void)
982 {
983 	int state;
984 	double cptime;
985 
986 	cptime = 0.0;
987 
988 	for (state = 0; state < CPUSTATES; ++state)
989 		cptime += cur.cp_time[state];
990 	for (state = 0; state < CPUSTATES; ++state)
991 		printf(" %2.0f",
992 		       rint(100. * cur.cp_time[state] / (cptime ? cptime : 1)));
993 }
994 
995 static int
996 readvar(kvm_t *kd, const char *name, int nlid, void *ptr, size_t len)
997 {
998 	if (kd != NULL) {
999 		ssize_t nbytes;
1000 
1001 		nbytes = kvm_read(kd, namelist[nlid].n_value, ptr, len);
1002 
1003 		if (nbytes < 0) {
1004 			warnx("kvm_read(%s): %s", namelist[nlid].n_name,
1005 			    kvm_geterr(kd));
1006 			return (1);
1007 		} else if ((size_t)nbytes != len) {
1008 			warnx("kvm_read(%s): expected %zu bytes, got %zd bytes",
1009 			      namelist[nlid].n_name, len, nbytes);
1010 			return (1);
1011 		}
1012 	} else {
1013 		size_t nlen = len;
1014 
1015 		if (sysctlbyname(name, ptr, &nlen, NULL, 0) == -1) {
1016 			warn("sysctl(%s...) failed", name);
1017 			return (1);
1018 		}
1019 		if (nlen != len) {
1020 			warnx("sysctl(%s...): expected %lu, got %lu", name,
1021 			      (unsigned long)len, (unsigned long)nlen);
1022 			return (1);
1023 		}
1024 	}
1025 	return (0);
1026 }
1027