xref: /freebsd/usr.sbin/iostat/iostat.c (revision 9336e0699bda8a301cd2bfa37106b6ec5e32012e)
1 /*
2  * Copyright (c) 1997, 1998, 2000, 2001  Kenneth D. Merry
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. The name of the author may not be used to endorse or promote products
14  *    derived from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $FreeBSD$
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  * 3. All advertising materials mentioning features or use of this software
47  *    must display the following acknowledgement:
48  *	This product includes software developed by the University of
49  *	California, Berkeley and its contributors.
50  * 4. Neither the name of the University nor the names of its contributors
51  *    may be used to endorse or promote products derived from this software
52  *    without specific prior written permission.
53  *
54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
64  * SUCH DAMAGE.
65  */
66 /*
67  * Ideas for the new iostat statistics output modes taken from the NetBSD
68  * version of iostat:
69  */
70 /*
71  * Copyright (c) 1996 John M. Vinopal
72  * All rights reserved.
73  *
74  * Redistribution and use in source and binary forms, with or without
75  * modification, are permitted provided that the following conditions
76  * are met:
77  * 1. Redistributions of source code must retain the above copyright
78  *    notice, this list of conditions and the following disclaimer.
79  * 2. Redistributions in binary form must reproduce the above copyright
80  *    notice, this list of conditions and the following disclaimer in the
81  *    documentation and/or other materials provided with the distribution.
82  * 3. All advertising materials mentioning features or use of this software
83  *    must display the following acknowledgement:
84  *      This product includes software developed for the NetBSD Project
85  *      by John M. Vinopal.
86  * 4. The name of the author may not be used to endorse or promote products
87  *    derived from this software without specific prior written permission.
88  *
89  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
90  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
91  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
92  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
93  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
94  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
95  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
96  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
97  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
98  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
99  * SUCH DAMAGE.
100  */
101 
102 
103 #include <sys/param.h>
104 #include <sys/errno.h>
105 #include <sys/resource.h>
106 #include <sys/sysctl.h>
107 
108 #include <err.h>
109 #include <ctype.h>
110 #include <fcntl.h>
111 #include <kvm.h>
112 #include <nlist.h>
113 #include <stdio.h>
114 #include <stdlib.h>
115 #include <string.h>
116 #include <unistd.h>
117 #include <limits.h>
118 #include <devstat.h>
119 #include <math.h>
120 
121 struct nlist namelist[] = {
122 #define X_TK_NIN	0
123 	{ "_tk_nin" },
124 #define X_TK_NOUT	1
125 	{ "_tk_nout" },
126 #define X_CP_TIME	2
127 	{ "_cp_time" },
128 #define X_BOOTTIME	3
129 	{ "_boottime" },
130 #define X_END		3
131 	{ NULL },
132 };
133 
134 struct statinfo cur, last;
135 int num_devices;
136 struct device_selection *dev_select;
137 int maxshowdevs;
138 volatile sig_atomic_t headercount;
139 int dflag = 0, Iflag = 0, Cflag = 0, Tflag = 0, oflag = 0, Kflag = 0;
140 int xflag = 0, zflag = 0;
141 
142 /* local function declarations */
143 static void usage(void);
144 static void needhdr(int signo);
145 static void phdr(void);
146 static void devstats(int perf_select, long double etime, int havelast);
147 static void cpustats(void);
148 static int readvar(kvm_t *kd, const char *name, int nlid, void *ptr,
149 		   size_t len);
150 
151 static void
152 usage(void)
153 {
154 	/*
155 	 * We also support the following 'traditional' syntax:
156 	 * iostat [drives] [wait [count]]
157 	 * This isn't mentioned in the man page, or the usage statement,
158 	 * but it is supported.
159 	 */
160 	fprintf(stderr, "usage: iostat [-CdhIKoTxz?] [-c count] [-M core]"
161 		" [-n devs] [-N system]\n"
162 		"\t      [-t type,if,pass] [-w wait] [drives]\n");
163 }
164 
165 int
166 main(int argc, char **argv)
167 {
168 	int c, i;
169 	int tflag = 0, hflag = 0, cflag = 0, wflag = 0, nflag = 0;
170 	int count = 0, waittime = 0;
171 	char *memf = NULL, *nlistf = NULL;
172 	struct devstat_match *matches;
173 	int num_matches = 0;
174 	char errbuf[_POSIX2_LINE_MAX];
175 	kvm_t *kd = NULL;
176 	long generation;
177 	int num_devices_specified;
178 	int num_selected, num_selections;
179 	long select_generation;
180 	char **specified_devices;
181 	devstat_select_mode select_mode;
182 	int havelast = 0;
183 
184 	matches = NULL;
185 	maxshowdevs = 3;
186 
187 	while ((c = getopt(argc, argv, "c:CdhIKM:n:N:ot:Tw:xz?")) != -1) {
188 		switch(c) {
189 			case 'c':
190 				cflag++;
191 				count = atoi(optarg);
192 				if (count < 1)
193 					errx(1, "count %d is < 1", count);
194 				break;
195 			case 'C':
196 				Cflag++;
197 				break;
198 			case 'd':
199 				dflag++;
200 				break;
201 			case 'h':
202 				hflag++;
203 				break;
204 			case 'I':
205 				Iflag++;
206 				break;
207 			case 'K':
208 				Kflag++;
209 				break;
210 			case 'M':
211 				memf = optarg;
212 				break;
213 			case 'n':
214 				nflag++;
215 				maxshowdevs = atoi(optarg);
216 				if (maxshowdevs < 0)
217 					errx(1, "number of devices %d is < 0",
218 					     maxshowdevs);
219 				break;
220 			case 'N':
221 				nlistf = optarg;
222 				break;
223 			case 'o':
224 				oflag++;
225 				break;
226 			case 't':
227 				tflag++;
228 				if (devstat_buildmatch(optarg, &matches,
229 						       &num_matches) != 0)
230 					errx(1, "%s", devstat_errbuf);
231 				break;
232 			case 'T':
233 				Tflag++;
234 				break;
235 			case 'w':
236 				wflag++;
237 				waittime = atoi(optarg);
238 				if (waittime < 1)
239 					errx(1, "wait time is < 1");
240 				break;
241 			case 'x':
242 				xflag++;
243 				break;
244 			case 'z':
245 				zflag++;
246 				break;
247 			default:
248 				usage();
249 				exit(1);
250 				break;
251 		}
252 	}
253 
254 	argc -= optind;
255 	argv += optind;
256 
257 	if (nlistf != NULL || memf != NULL) {
258 		kd = kvm_openfiles(nlistf, memf, NULL, O_RDONLY, errbuf);
259 
260 		if (kd == NULL)
261 			errx(1, "kvm_openfiles: %s", errbuf);
262 
263 		if (kvm_nlist(kd, namelist) == -1)
264 			errx(1, "kvm_nlist: %s", kvm_geterr(kd));
265 	}
266 
267 	/*
268 	 * Make sure that the userland devstat version matches the kernel
269 	 * devstat version.  If not, exit and print a message informing
270 	 * the user of his mistake.
271 	 */
272 	if (devstat_checkversion(kd) < 0)
273 		errx(1, "%s", devstat_errbuf);
274 
275 	/*
276 	 * Make sure Tflag and/or Cflag are set if dflag == 0.  If dflag is
277 	 * greater than 0, they may be 0 or non-zero.
278 	 */
279 	if (dflag == 0 && xflag == 0) {
280 		Cflag = 1;
281 		Tflag = 1;
282 	}
283 
284 	/* find out how many devices we have */
285 	if ((num_devices = devstat_getnumdevs(kd)) < 0)
286 		err(1, "can't get number of devices");
287 
288 	/*
289 	 * Figure out how many devices we should display.
290 	 */
291 	if (nflag == 0) {
292 		if (xflag > 0)
293 			maxshowdevs = num_devices;
294 		else if (oflag > 0) {
295 			if ((dflag > 0) && (Cflag == 0) && (Tflag == 0))
296 				maxshowdevs = 5;
297 			else if ((dflag > 0) && (Tflag > 0) && (Cflag == 0))
298 				maxshowdevs = 5;
299 			else
300 				maxshowdevs = 4;
301 		} else {
302 			if ((dflag > 0) && (Cflag == 0))
303 				maxshowdevs = 4;
304 			else
305 				maxshowdevs = 3;
306 		}
307 	}
308 
309 	cur.dinfo = (struct devinfo *)malloc(sizeof(struct devinfo));
310 	if (cur.dinfo == NULL)
311 		err(1, "malloc failed");
312 
313 	last.dinfo = (struct devinfo *)malloc(sizeof(struct devinfo));
314 	if (last.dinfo == NULL)
315 		err(1, "malloc failed");
316 
317 	bzero(cur.dinfo, sizeof(struct devinfo));
318 	bzero(last.dinfo, sizeof(struct devinfo));
319 
320 	/*
321 	 * Grab all the devices.  We don't look to see if the list has
322 	 * changed here, since it almost certainly has.  We only look for
323 	 * errors.
324 	 */
325 	if (devstat_getdevs(kd, &cur) == -1)
326 		errx(1, "%s", devstat_errbuf);
327 
328 	num_devices = cur.dinfo->numdevs;
329 	generation = cur.dinfo->generation;
330 
331 	/*
332 	 * If the user specified any devices on the command line, see if
333 	 * they are in the list of devices we have now.
334 	 */
335 	specified_devices = (char **)malloc(sizeof(char *));
336 	if (specified_devices == NULL)
337 		err(1, "malloc failed");
338 
339 	for (num_devices_specified = 0; *argv; ++argv) {
340 		if (isdigit(**argv))
341 			break;
342 		num_devices_specified++;
343 		specified_devices = (char **)realloc(specified_devices,
344 						     sizeof(char *) *
345 						     num_devices_specified);
346 		if (specified_devices == NULL)
347 			err(1, "realloc failed");
348 
349 		specified_devices[num_devices_specified - 1] = *argv;
350 
351 	}
352 	if (nflag == 0 && maxshowdevs < num_devices_specified)
353 		maxshowdevs = num_devices_specified;
354 
355 	dev_select = NULL;
356 
357 	if ((num_devices_specified == 0) && (num_matches == 0))
358 		select_mode = DS_SELECT_ADD;
359 	else
360 		select_mode = DS_SELECT_ONLY;
361 
362 	/*
363 	 * At this point, selectdevs will almost surely indicate that the
364 	 * device list has changed, so we don't look for return values of 0
365 	 * or 1.  If we get back -1, though, there is an error.
366 	 */
367 	if (devstat_selectdevs(&dev_select, &num_selected,
368 			       &num_selections, &select_generation, generation,
369 			       cur.dinfo->devices, num_devices, matches,
370 			       num_matches, specified_devices,
371 			       num_devices_specified, select_mode, maxshowdevs,
372 			       hflag) == -1)
373 		errx(1, "%s", devstat_errbuf);
374 
375 	/*
376 	 * Look for the traditional wait time and count arguments.
377 	 */
378 	if (*argv) {
379 		waittime = atoi(*argv);
380 
381 		/* Let the user know he goofed, but keep going anyway */
382 		if (wflag != 0)
383 			warnx("discarding previous wait interval, using"
384 			      " %d instead", waittime);
385 		wflag++;
386 
387 		if (*++argv) {
388 			count = atoi(*argv);
389 			if (cflag != 0)
390 				warnx("discarding previous count, using %d"
391 				      " instead", count);
392 			cflag++;
393 		} else
394 			count = -1;
395 	}
396 
397 	/*
398 	 * If the user specified a count, but not an interval, we default
399 	 * to an interval of 1 second.
400 	 */
401 	if ((wflag == 0) && (cflag > 0))
402 		waittime = 1;
403 
404 	/*
405 	 * If the user specified a wait time, but not a count, we want to
406 	 * go on ad infinitum.  This can be redundant if the user uses the
407 	 * traditional method of specifying the wait, since in that case we
408 	 * already set count = -1 above.  Oh well.
409 	 */
410 	if ((wflag > 0) && (cflag == 0))
411 		count = -1;
412 
413 	bzero(&cur.cp_time, sizeof(cur.cp_time));
414 	cur.tk_nout = 0;
415 	cur.tk_nin = 0;
416 
417 	/*
418 	 * Set the snap time to the system boot time (ie: zero), so the
419 	 * stats are calculated since system boot.
420 	 */
421 	cur.snap_time = 0;
422 
423 	/*
424 	 * If the user stops the program (control-Z) and then resumes it,
425 	 * print out the header again.
426 	 */
427 	(void)signal(SIGCONT, needhdr);
428 
429 	for (headercount = 1;;) {
430 		struct devinfo *tmp_dinfo;
431 		long tmp;
432 		long double etime;
433 
434 		if (Tflag > 0) {
435 			if ((readvar(kd, "kern.tty_nin", X_TK_NIN, &cur.tk_nin,
436 			     sizeof(cur.tk_nin)) != 0)
437 			 || (readvar(kd, "kern.tty_nout", X_TK_NOUT,
438 			     &cur.tk_nout, sizeof(cur.tk_nout))!= 0)) {
439 				Tflag = 0;
440 				warnx("disabling TTY statistics");
441 			}
442 		 }
443 
444 		if (Cflag > 0) {
445 			if (readvar(kd, "kern.cp_time", X_CP_TIME,
446 			    &cur.cp_time, sizeof(cur.cp_time)) != 0) {
447 				Cflag = 0;
448 				warnx("disabling CPU time statistics");
449 			}
450 		}
451 
452 		if (!--headercount) {
453 			phdr();
454 			headercount = 20;
455 		}
456 
457 		tmp_dinfo = last.dinfo;
458 		last.dinfo = cur.dinfo;
459 		cur.dinfo = tmp_dinfo;
460 
461 		last.snap_time = cur.snap_time;
462 
463 		/*
464 		 * Here what we want to do is refresh our device stats.
465 		 * devstat_getdevs() returns 1 when the device list has changed.
466 		 * If the device list has changed, we want to go through
467 		 * the selection process again, in case a device that we
468 		 * were previously displaying has gone away.
469 		 */
470 		switch (devstat_getdevs(kd, &cur)) {
471 		case -1:
472 			errx(1, "%s", devstat_errbuf);
473 			break;
474 		case 1: {
475 			int retval;
476 
477 			num_devices = cur.dinfo->numdevs;
478 			generation = cur.dinfo->generation;
479 			retval = devstat_selectdevs(&dev_select, &num_selected,
480 						    &num_selections,
481 						    &select_generation,
482 						    generation,
483 						    cur.dinfo->devices,
484 						    num_devices, matches,
485 						    num_matches,
486 						    specified_devices,
487 						    num_devices_specified,
488 						    select_mode, maxshowdevs,
489 						    hflag);
490 			switch(retval) {
491 			case -1:
492 				errx(1, "%s", devstat_errbuf);
493 				break;
494 			case 1:
495 				phdr();
496 				headercount = 20;
497 				break;
498 			default:
499 				break;
500 			}
501 			break;
502 		}
503 		default:
504 			break;
505 		}
506 
507 		/*
508 		 * We only want to re-select devices if we're in 'top'
509 		 * mode.  This is the only mode where the devices selected
510 		 * could actually change.
511 		 */
512 		if (hflag > 0) {
513 			int retval;
514 			retval = devstat_selectdevs(&dev_select, &num_selected,
515 						    &num_selections,
516 						    &select_generation,
517 						    generation,
518 						    cur.dinfo->devices,
519 						    num_devices, matches,
520 						    num_matches,
521 						    specified_devices,
522 						    num_devices_specified,
523 						    select_mode, maxshowdevs,
524 						    hflag);
525 			switch(retval) {
526 			case -1:
527 				errx(1,"%s", devstat_errbuf);
528 				break;
529 			case 1:
530 				phdr();
531 				headercount = 20;
532 				break;
533 			default:
534 				break;
535 			}
536 		}
537 
538 		if (Tflag > 0) {
539 			tmp = cur.tk_nin;
540 			cur.tk_nin -= last.tk_nin;
541 			last.tk_nin = tmp;
542 			tmp = cur.tk_nout;
543 			cur.tk_nout -= last.tk_nout;
544 			last.tk_nout = tmp;
545 		}
546 
547 		etime = cur.snap_time - last.snap_time;
548 
549 		if (etime == 0.0)
550 			etime = 1.0;
551 
552 		for (i = 0; i < CPUSTATES; i++) {
553 			tmp = cur.cp_time[i];
554 			cur.cp_time[i] -= last.cp_time[i];
555 			last.cp_time[i] = tmp;
556 		}
557 
558 		if (xflag == 0 && Tflag > 0)
559 			printf("%4.0Lf%5.0Lf", cur.tk_nin / etime,
560 			    cur.tk_nout / etime);
561 
562 		devstats(hflag, etime, havelast);
563 
564 		if (xflag == 0) {
565 			if (Cflag > 0)
566 				cpustats();
567 
568 			printf("\n");
569 		}
570 		fflush(stdout);
571 
572 		if (count >= 0 && --count <= 0)
573 			break;
574 
575 		sleep(waittime);
576 		havelast = 1;
577 	}
578 
579 	exit(0);
580 }
581 
582 /*
583  * Force a header to be prepended to the next output.
584  */
585 void
586 needhdr(int signo)
587 {
588 
589 	headercount = 1;
590 }
591 
592 static void
593 phdr(void)
594 {
595 	int i, printed;
596 
597 	/*
598 	 * If xflag is set, we need a per-loop header, not a page header, so
599 	 * just return.  We'll print the header in devstats().
600 	 */
601 	if (xflag > 0)
602 		return;
603 
604 	if (Tflag > 0)
605 		(void)printf("      tty");
606 	for (i = 0, printed=0;(i < num_devices) && (printed < maxshowdevs);i++){
607 		int di;
608 		if ((dev_select[i].selected != 0)
609 		 && (dev_select[i].selected <= maxshowdevs)) {
610 			di = dev_select[i].position;
611 			if (oflag > 0)
612 				(void)printf("%12.6s%d ",
613 					    cur.dinfo->devices[di].device_name,
614 					    cur.dinfo->devices[di].unit_number);
615 			else
616 				printf("%15.6s%d ",
617 					    cur.dinfo->devices[di].device_name,
618 					    cur.dinfo->devices[di].unit_number);
619 			printed++;
620 		}
621 	}
622 	if (Cflag > 0)
623 		(void)printf("            cpu\n");
624 	else
625 		(void)printf("\n");
626 
627 	if (Tflag > 0)
628 		(void)printf(" tin tout");
629 
630 	for (i=0, printed = 0;(i < num_devices) && (printed < maxshowdevs);i++){
631 		if ((dev_select[i].selected != 0)
632 		 && (dev_select[i].selected <= maxshowdevs)) {
633 			if (oflag > 0) {
634 				if (Iflag == 0)
635 					(void)printf(" sps tps msps ");
636 				else
637 					(void)printf(" blk xfr msps ");
638 			} else {
639 				if (Iflag == 0)
640 					printf("  KB/t tps  MB/s ");
641 				else
642 					printf("  KB/t xfrs   MB ");
643 			}
644 			printed++;
645 		}
646 	}
647 	if (Cflag > 0)
648 		(void)printf(" us ni sy in id\n");
649 	else
650 		printf("\n");
651 
652 }
653 
654 static void
655 devstats(int perf_select, long double etime, int havelast)
656 {
657 	int dn;
658 	long double transfers_per_second, transfers_per_second_read, transfers_per_second_write;
659 	long double kb_per_transfer, mb_per_second, mb_per_second_read, mb_per_second_write;
660 	u_int64_t total_bytes, total_transfers, total_blocks;
661 	u_int64_t total_bytes_read, total_transfers_read;
662 	u_int64_t total_bytes_write, total_transfers_write;
663 	long double busy_pct;
664 	u_int64_t queue_len;
665 	long double total_mb;
666 	long double blocks_per_second, ms_per_transaction;
667 	int firstline = 1;
668 	char *devname;
669 
670 	if (xflag > 0) {
671 		printf("                        extended device statistics  ");
672 		if (Tflag > 0)
673 			printf("     tty ");
674 		if (Cflag > 0)
675 			printf("           cpu ");
676 		printf("\n");
677 		if (Iflag == 0)
678 			printf(
679 		"device     r/s   w/s    kr/s    kw/s wait svc_t  %%b  "
680 			    );
681 		else
682 			printf(
683 		"device     r/i   w/i    kr/i    kw/i wait svc_t  %%b  "
684 			    );
685 		if (Tflag > 0)
686 			printf("tin tout ");
687 		if (Cflag > 0)
688 			printf("us ni sy in id ");
689 		printf("\n");
690 	}
691 
692 	for (dn = 0; dn < num_devices; dn++) {
693 		int di;
694 
695 		if (((perf_select == 0) && (dev_select[dn].selected == 0))
696 		 || (dev_select[dn].selected > maxshowdevs))
697 			continue;
698 
699 		di = dev_select[dn].position;
700 
701 		if (devstat_compute_statistics(&cur.dinfo->devices[di],
702 		    havelast ? &last.dinfo->devices[di] : NULL, etime,
703 		    DSM_TOTAL_BYTES, &total_bytes,
704 		    DSM_TOTAL_BYTES_READ, &total_bytes_read,
705 		    DSM_TOTAL_BYTES_WRITE, &total_bytes_write,
706 		    DSM_TOTAL_TRANSFERS, &total_transfers,
707 		    DSM_TOTAL_TRANSFERS_READ, &total_transfers_read,
708 		    DSM_TOTAL_TRANSFERS_WRITE, &total_transfers_write,
709 		    DSM_TOTAL_BLOCKS, &total_blocks,
710 		    DSM_KB_PER_TRANSFER, &kb_per_transfer,
711 		    DSM_TRANSFERS_PER_SECOND, &transfers_per_second,
712 		    DSM_TRANSFERS_PER_SECOND_READ, &transfers_per_second_read,
713 		    DSM_TRANSFERS_PER_SECOND_WRITE, &transfers_per_second_write,
714 		    DSM_MB_PER_SECOND, &mb_per_second,
715 		    DSM_MB_PER_SECOND_READ, &mb_per_second_read,
716 		    DSM_MB_PER_SECOND_WRITE, &mb_per_second_write,
717 		    DSM_BLOCKS_PER_SECOND, &blocks_per_second,
718 		    DSM_MS_PER_TRANSACTION, &ms_per_transaction,
719 		    DSM_BUSY_PCT, &busy_pct,
720 		    DSM_QUEUE_LENGTH, &queue_len,
721 		    DSM_NONE) != 0)
722 			errx(1, "%s", devstat_errbuf);
723 
724 		if (perf_select != 0) {
725 			dev_select[dn].bytes = total_bytes;
726 			if ((dev_select[dn].selected == 0)
727 			 || (dev_select[dn].selected > maxshowdevs))
728 				continue;
729 		}
730 
731 		if (Kflag > 0 || xflag > 0) {
732 			int block_size = cur.dinfo->devices[di].block_size;
733 			total_blocks = total_blocks * (block_size ?
734 						       block_size : 512) / 1024;
735 		}
736 
737 		if (xflag > 0) {
738 			asprintf(&devname, "%s%d",
739 			    cur.dinfo->devices[di].device_name,
740 			    cur.dinfo->devices[di].unit_number);
741 			/*
742 			 * If zflag is set, skip any devices with zero I/O.
743 			 */
744 			if (zflag == 0 || transfers_per_second_read > 0.05 ||
745 			    transfers_per_second_write > 0.05 ||
746 			    mb_per_second_read > ((long double).0005)/1024 ||
747 			    mb_per_second_write > ((long double).0005)/1024 ||
748 			    busy_pct > 0.5) {
749 				if (Iflag == 0)
750 					printf("%-8.8s %5.1Lf %5.1Lf %7.1Lf %7.1Lf %4qu %5.1Lf %3.0Lf ",
751 					    devname, transfers_per_second_read,
752 					    transfers_per_second_write,
753 					    mb_per_second_read * 1024,
754 					    mb_per_second_write * 1024,
755 					    queue_len,
756 					    ms_per_transaction, busy_pct);
757 				else
758 					printf("%-8.8s %5.1Lf %5.1Lf %7.1Lf %7.1Lf %4qu %5.1Lf %3.0Lf ",
759 					    devname,
760 					    (long double)total_transfers_read,
761 					    (long double)total_transfers_write,
762 					    (long double)
763 					        total_bytes_read / 1024,
764 					    (long double)
765 					        total_bytes_write / 1024,
766 					    queue_len,
767 					    ms_per_transaction, busy_pct);
768 				if (firstline) {
769 					/*
770 					 * If this is the first device
771 					 * we're printing, also print
772 					 * CPU or TTY stats if requested.
773 					 */
774 					firstline = 0;
775 					if (Tflag > 0)
776 						printf("%4.0Lf%5.0Lf",
777 						    cur.tk_nin / etime,
778 						    cur.tk_nout / etime);
779 					if (Cflag > 0)
780 						cpustats();
781 				}
782 				printf("\n");
783 			}
784 		} else if (oflag > 0) {
785 			int msdig = (ms_per_transaction < 100.0) ? 1 : 0;
786 
787 			if (Iflag == 0)
788 				printf("%4.0Lf%4.0Lf%5.*Lf ",
789 				       blocks_per_second,
790 				       transfers_per_second,
791 				       msdig,
792 				       ms_per_transaction);
793 			else
794 				printf("%4.1qu%4.1qu%5.*Lf ",
795 				       total_blocks,
796 				       total_transfers,
797 				       msdig,
798 				       ms_per_transaction);
799 		} else {
800 			if (Iflag == 0)
801 				printf(" %5.2Lf %3.0Lf %5.2Lf ",
802 				       kb_per_transfer,
803 				       transfers_per_second,
804 				       mb_per_second);
805 			else {
806 				total_mb = total_bytes;
807 				total_mb /= 1024 * 1024;
808 
809 				printf(" %5.2Lf %3.1qu %5.2Lf ",
810 				       kb_per_transfer,
811 				       total_transfers,
812 				       total_mb);
813 			}
814 		}
815 	}
816 	if (xflag > 0 && zflag > 0 && firstline == 1 &&
817 	    (Tflag > 0 || Cflag > 0)) {
818 		/*
819 		 * If zflag is set and we did not print any device
820 		 * lines I/O because they were all zero,
821 		 * print TTY/CPU stats.
822 		 */
823 		printf("%52s","");
824 		if (Tflag > 0)
825 			printf("%4.0Lf%5.0Lf", cur.tk_nin / etime,
826 			    cur.tk_nout / etime);
827 		if (Cflag > 0)
828 			cpustats();
829 		printf("\n");
830 	}
831 }
832 
833 static void
834 cpustats(void)
835 {
836 	int state;
837 	double time;
838 
839 	time = 0.0;
840 
841 	for (state = 0; state < CPUSTATES; ++state)
842 		time += cur.cp_time[state];
843 	for (state = 0; state < CPUSTATES; ++state)
844 		printf(" %2.0f",
845 		       rint(100. * cur.cp_time[state] / (time ? time : 1)));
846 }
847 
848 static int
849 readvar(kvm_t *kd, const char *name, int nlid, void *ptr, size_t len)
850 {
851 	if (kd != NULL) {
852 		ssize_t nbytes;
853 
854 		nbytes = kvm_read(kd, namelist[nlid].n_value, ptr, len);
855 
856 		if (nbytes < 0) {
857 			warnx("kvm_read(%s): %s", namelist[nlid].n_name,
858 			    kvm_geterr(kd));
859 			return (1);
860 		}
861 		if (nbytes != len) {
862 			warnx("kvm_read(%s): expected %zu bytes, got %zd bytes",
863 			      namelist[nlid].n_name, len, nbytes);
864 			return (1);
865 		}
866 	} else {
867 		size_t nlen = len;
868 
869 		if (sysctlbyname(name, ptr, &nlen, NULL, 0) == -1) {
870 			warn("sysctl(%s...) failed", name);
871 			return (1);
872 		}
873 		if (nlen != len) {
874 			warnx("sysctl(%s...): expected %lu, got %lu", name,
875 			      (unsigned long)len, (unsigned long)nlen);
876 			return (1);
877 		}
878 	}
879 	return (0);
880 }
881