xref: /freebsd/usr.sbin/iostat/iostat.c (revision f0adf7f5cdd241db2f2c817683191a6ef64a4e95)
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 
141 /* local function declarations */
142 static void usage(void);
143 static void needhdr(int signo);
144 static void phdr(void);
145 static void devstats(int perf_select, long double etime, int havelast);
146 static void cpustats(void);
147 static int readvar(kvm_t *kd, const char *name, int nlid, void *ptr,
148 		   size_t len);
149 
150 static void
151 usage(void)
152 {
153 	/*
154 	 * We also support the following 'traditional' syntax:
155 	 * iostat [drives] [wait [count]]
156 	 * This isn't mentioned in the man page, or the usage statement,
157 	 * but it is supported.
158 	 */
159 	fprintf(stderr, "usage: iostat [-CdhIKoT?] [-c count] [-M core]"
160 		" [-n devs] [-N system]\n"
161 		"\t      [-t type,if,pass] [-w wait] [drives]\n");
162 }
163 
164 int
165 main(int argc, char **argv)
166 {
167 	int c;
168 	register int 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:?")) != -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 			default:
242 				usage();
243 				exit(1);
244 				break;
245 		}
246 	}
247 
248 	argc -= optind;
249 	argv += optind;
250 
251 	if (nlistf != NULL || memf != NULL) {
252 		kd = kvm_openfiles(nlistf, memf, NULL, O_RDONLY, errbuf);
253 
254 		if (kd == NULL)
255 			errx(1, "kvm_openfiles: %s", errbuf);
256 
257 		if (kvm_nlist(kd, namelist) == -1)
258 			errx(1, "kvm_nlist: %s", kvm_geterr(kd));
259 	}
260 
261 	/*
262 	 * Make sure that the userland devstat version matches the kernel
263 	 * devstat version.  If not, exit and print a message informing
264 	 * the user of his mistake.
265 	 */
266 	if (devstat_checkversion(kd) < 0)
267 		errx(1, "%s", devstat_errbuf);
268 
269 	/*
270 	 * Make sure Tflag and/or Cflag are set if dflag == 0.  If dflag is
271 	 * greater than 0, they may be 0 or non-zero.
272 	 */
273 	if (dflag == 0) {
274 		Cflag = 1;
275 		Tflag = 1;
276 	}
277 
278 	/*
279 	 * Figure out how many devices we should display.
280 	 */
281 	if (nflag == 0) {
282 		if (oflag > 0) {
283 			if ((dflag > 0) && (Cflag == 0) && (Tflag == 0))
284 				maxshowdevs = 5;
285 			else if ((dflag > 0) && (Tflag > 0) && (Cflag == 0))
286 				maxshowdevs = 5;
287 			else
288 				maxshowdevs = 4;
289 		} else {
290 			if ((dflag > 0) && (Cflag == 0))
291 				maxshowdevs = 4;
292 			else
293 				maxshowdevs = 3;
294 		}
295 	}
296 
297 	/* find out how many devices we have */
298 	if ((num_devices = devstat_getnumdevs(kd)) < 0)
299 		err(1, "can't get number of devices");
300 
301 	cur.dinfo = (struct devinfo *)malloc(sizeof(struct devinfo));
302 	if (cur.dinfo == NULL)
303 		err(1, "malloc failed");
304 
305 	last.dinfo = (struct devinfo *)malloc(sizeof(struct devinfo));
306 	if (last.dinfo == NULL)
307 		err(1, "malloc failed");
308 
309 	bzero(cur.dinfo, sizeof(struct devinfo));
310 	bzero(last.dinfo, sizeof(struct devinfo));
311 
312 	/*
313 	 * Grab all the devices.  We don't look to see if the list has
314 	 * changed here, since it almost certainly has.  We only look for
315 	 * errors.
316 	 */
317 	if (devstat_getdevs(kd, &cur) == -1)
318 		errx(1, "%s", devstat_errbuf);
319 
320 	num_devices = cur.dinfo->numdevs;
321 	generation = cur.dinfo->generation;
322 
323 	/*
324 	 * If the user specified any devices on the command line, see if
325 	 * they are in the list of devices we have now.
326 	 */
327 	specified_devices = (char **)malloc(sizeof(char *));
328 	if (specified_devices == NULL)
329 		err(1, "malloc failed");
330 
331 	for (num_devices_specified = 0; *argv; ++argv) {
332 		if (isdigit(**argv))
333 			break;
334 		num_devices_specified++;
335 		specified_devices = (char **)realloc(specified_devices,
336 						     sizeof(char *) *
337 						     num_devices_specified);
338 		if (specified_devices == NULL)
339 			err(1, "realloc failed");
340 
341 		specified_devices[num_devices_specified - 1] = *argv;
342 
343 	}
344 	if (nflag == 0 && maxshowdevs < num_devices_specified)
345 		maxshowdevs = num_devices_specified;
346 
347 	dev_select = NULL;
348 
349 	if ((num_devices_specified == 0) && (num_matches == 0))
350 		select_mode = DS_SELECT_ADD;
351 	else
352 		select_mode = DS_SELECT_ONLY;
353 
354 	/*
355 	 * At this point, selectdevs will almost surely indicate that the
356 	 * device list has changed, so we don't look for return values of 0
357 	 * or 1.  If we get back -1, though, there is an error.
358 	 */
359 	if (devstat_selectdevs(&dev_select, &num_selected,
360 			       &num_selections, &select_generation, generation,
361 			       cur.dinfo->devices, num_devices, matches,
362 			       num_matches, specified_devices,
363 			       num_devices_specified, select_mode, maxshowdevs,
364 			       hflag) == -1)
365 		errx(1, "%s", devstat_errbuf);
366 
367 	/*
368 	 * Look for the traditional wait time and count arguments.
369 	 */
370 	if (*argv) {
371 		waittime = atoi(*argv);
372 
373 		/* Let the user know he goofed, but keep going anyway */
374 		if (wflag != 0)
375 			warnx("discarding previous wait interval, using"
376 			      " %d instead", waittime);
377 		wflag++;
378 
379 		if (*++argv) {
380 			count = atoi(*argv);
381 			if (cflag != 0)
382 				warnx("discarding previous count, using %d"
383 				      " instead", count);
384 			cflag++;
385 		} else
386 			count = -1;
387 	}
388 
389 	/*
390 	 * If the user specified a count, but not an interval, we default
391 	 * to an interval of 1 second.
392 	 */
393 	if ((wflag == 0) && (cflag > 0))
394 		waittime = 1;
395 
396 	/*
397 	 * If the user specified a wait time, but not a count, we want to
398 	 * go on ad infinitum.  This can be redundant if the user uses the
399 	 * traditional method of specifying the wait, since in that case we
400 	 * already set count = -1 above.  Oh well.
401 	 */
402 	if ((wflag > 0) && (cflag == 0))
403 		count = -1;
404 
405 	bzero(&cur.cp_time, sizeof(cur.cp_time));
406 	cur.tk_nout = 0;
407 	cur.tk_nin = 0;
408 
409 	/*
410 	 * Set the snap time to the system boot time (ie: zero), so the
411 	 * stats are calculated since system boot.
412 	 */
413 	cur.snap_time = 0;
414 
415 	/*
416 	 * If the user stops the program (control-Z) and then resumes it,
417 	 * print out the header again.
418 	 */
419 	(void)signal(SIGCONT, needhdr);
420 
421 	for (headercount = 1;;) {
422 		struct devinfo *tmp_dinfo;
423 		long tmp;
424 		long double etime;
425 
426 		if (Tflag > 0) {
427 			if ((readvar(kd, "kern.tty_nin", X_TK_NIN, &cur.tk_nin,
428 			     sizeof(cur.tk_nin)) != 0)
429 			 || (readvar(kd, "kern.tty_nout", X_TK_NOUT,
430 			     &cur.tk_nout, sizeof(cur.tk_nout))!= 0)) {
431 				Tflag = 0;
432 				warnx("disabling TTY statistics");
433 			}
434 		 }
435 
436 		if (Cflag > 0) {
437 			if (readvar(kd, "kern.cp_time", X_CP_TIME,
438 			    &cur.cp_time, sizeof(cur.cp_time)) != 0) {
439 				Cflag = 0;
440 				warnx("disabling CPU time statistics");
441 			}
442 		}
443 
444 		if (!--headercount) {
445 			phdr();
446 			headercount = 20;
447 		}
448 
449 		tmp_dinfo = last.dinfo;
450 		last.dinfo = cur.dinfo;
451 		cur.dinfo = tmp_dinfo;
452 
453 		last.snap_time = cur.snap_time;
454 
455 		/*
456 		 * Here what we want to do is refresh our device stats.
457 		 * devstat_getdevs() returns 1 when the device list has changed.
458 		 * If the device list has changed, we want to go through
459 		 * the selection process again, in case a device that we
460 		 * were previously displaying has gone away.
461 		 */
462 		switch (devstat_getdevs(kd, &cur)) {
463 		case -1:
464 			errx(1, "%s", devstat_errbuf);
465 			break;
466 		case 1: {
467 			int retval;
468 
469 			num_devices = cur.dinfo->numdevs;
470 			generation = cur.dinfo->generation;
471 			retval = devstat_selectdevs(&dev_select, &num_selected,
472 						    &num_selections,
473 						    &select_generation,
474 						    generation,
475 						    cur.dinfo->devices,
476 						    num_devices, matches,
477 						    num_matches,
478 						    specified_devices,
479 						    num_devices_specified,
480 						    select_mode, maxshowdevs,
481 						    hflag);
482 			switch(retval) {
483 			case -1:
484 				errx(1, "%s", devstat_errbuf);
485 				break;
486 			case 1:
487 				phdr();
488 				headercount = 20;
489 				break;
490 			default:
491 				break;
492 			}
493 			break;
494 		}
495 		default:
496 			break;
497 		}
498 
499 		/*
500 		 * We only want to re-select devices if we're in 'top'
501 		 * mode.  This is the only mode where the devices selected
502 		 * could actually change.
503 		 */
504 		if (hflag > 0) {
505 			int retval;
506 			retval = devstat_selectdevs(&dev_select, &num_selected,
507 						    &num_selections,
508 						    &select_generation,
509 						    generation,
510 						    cur.dinfo->devices,
511 						    num_devices, matches,
512 						    num_matches,
513 						    specified_devices,
514 						    num_devices_specified,
515 						    select_mode, maxshowdevs,
516 						    hflag);
517 			switch(retval) {
518 			case -1:
519 				errx(1,"%s", devstat_errbuf);
520 				break;
521 			case 1:
522 				phdr();
523 				headercount = 20;
524 				break;
525 			default:
526 				break;
527 			}
528 		}
529 
530 		if (Tflag > 0) {
531 			tmp = cur.tk_nin;
532 			cur.tk_nin -= last.tk_nin;
533 			last.tk_nin = tmp;
534 			tmp = cur.tk_nout;
535 			cur.tk_nout -= last.tk_nout;
536 			last.tk_nout = tmp;
537 		}
538 
539 		etime = cur.snap_time - last.snap_time;
540 
541 		if (etime == 0.0)
542 			etime = 1.0;
543 
544 		for (i = 0; i < CPUSTATES; i++) {
545 			tmp = cur.cp_time[i];
546 			cur.cp_time[i] -= last.cp_time[i];
547 			last.cp_time[i] = tmp;
548 		}
549 
550 		if (Tflag > 0)
551 			printf("%4.0Lf%5.0Lf", cur.tk_nin / etime,
552 				cur.tk_nout/etime);
553 
554 		devstats(hflag, etime, havelast);
555 
556 		if (Cflag > 0)
557 			cpustats();
558 
559 		printf("\n");
560 		fflush(stdout);
561 
562 		if (count >= 0 && --count <= 0)
563 			break;
564 
565 		sleep(waittime);
566 		havelast = 1;
567 	}
568 
569 	exit(0);
570 }
571 
572 /*
573  * Force a header to be prepended to the next output.
574  */
575 void
576 needhdr(int signo)
577 {
578 
579         headercount = 1;
580 }
581 
582 static void
583 phdr(void)
584 {
585 	register int i;
586 	int printed;
587 
588 	if (Tflag > 0)
589 		(void)printf("      tty");
590 	for (i = 0, printed=0;(i < num_devices) && (printed < maxshowdevs);i++){
591 		int di;
592 		if ((dev_select[i].selected != 0)
593 		 && (dev_select[i].selected <= maxshowdevs)) {
594 			di = dev_select[i].position;
595 			if (oflag > 0)
596 				(void)printf("%12.6s%d ",
597 					    cur.dinfo->devices[di].device_name,
598 					    cur.dinfo->devices[di].unit_number);
599 			else
600 				printf("%15.6s%d ",
601 					    cur.dinfo->devices[di].device_name,
602 					    cur.dinfo->devices[di].unit_number);
603 			printed++;
604 		}
605 	}
606 	if (Cflag > 0)
607 		(void)printf("            cpu\n");
608 	else
609 		(void)printf("\n");
610 
611 	if (Tflag > 0)
612 		(void)printf(" tin tout");
613 
614 	for (i=0, printed = 0;(i < num_devices) && (printed < maxshowdevs);i++){
615 		if ((dev_select[i].selected != 0)
616 		 && (dev_select[i].selected <= maxshowdevs)) {
617 			if (oflag > 0) {
618 				if (Iflag == 0)
619 					(void)printf(" sps tps msps ");
620 				else
621 					(void)printf(" blk xfr msps ");
622 			} else {
623 				if (Iflag == 0)
624 					printf("  KB/t tps  MB/s ");
625 				else
626 					printf("  KB/t xfrs   MB ");
627 			}
628 			printed++;
629 		}
630 	}
631 	if (Cflag > 0)
632 		(void)printf(" us ni sy in id\n");
633 	else
634 		printf("\n");
635 
636 }
637 
638 static void
639 devstats(int perf_select, long double etime, int havelast)
640 {
641 	register int dn;
642 	long double transfers_per_second;
643 	long double kb_per_transfer, mb_per_second;
644 	u_int64_t total_bytes, total_transfers, total_blocks;
645 	long double total_mb;
646 	long double blocks_per_second, ms_per_transaction;
647 
648 	for (dn = 0; dn < num_devices; dn++) {
649 		int di;
650 
651 		if (((perf_select == 0) && (dev_select[dn].selected == 0))
652 		 || (dev_select[dn].selected > maxshowdevs))
653 			continue;
654 
655 		di = dev_select[dn].position;
656 
657 		if (devstat_compute_statistics(&cur.dinfo->devices[di],
658 		    havelast ? &last.dinfo->devices[di] : NULL, etime,
659 		    DSM_TOTAL_BYTES, &total_bytes,
660 		    DSM_TOTAL_TRANSFERS, &total_transfers,
661 		    DSM_TOTAL_BLOCKS, &total_blocks,
662 		    DSM_KB_PER_TRANSFER, &kb_per_transfer,
663 		    DSM_TRANSFERS_PER_SECOND, &transfers_per_second,
664 		    DSM_MB_PER_SECOND, &mb_per_second,
665 		    DSM_BLOCKS_PER_SECOND, &blocks_per_second,
666 		    DSM_MS_PER_TRANSACTION, &ms_per_transaction,
667 		    DSM_NONE) != 0)
668 			errx(1, "%s", devstat_errbuf);
669 
670 		if (perf_select != 0) {
671 			dev_select[dn].bytes = total_bytes;
672 			if ((dev_select[dn].selected == 0)
673 			 || (dev_select[dn].selected > maxshowdevs))
674 				continue;
675 		}
676 
677 		if (Kflag) {
678 			int block_size = cur.dinfo->devices[di].block_size;
679 			total_blocks = total_blocks * (block_size ?
680 						       block_size : 512) / 1024;
681 		}
682 
683 		if (oflag > 0) {
684 			int msdig = (ms_per_transaction < 100.0) ? 1 : 0;
685 
686 			if (Iflag == 0)
687 				printf("%4.0Lf%4.0Lf%5.*Lf ",
688 				       blocks_per_second,
689 				       transfers_per_second,
690 				       msdig,
691 				       ms_per_transaction);
692 			else
693 				printf("%4.1qu%4.1qu%5.*Lf ",
694 				       total_blocks,
695 				       total_transfers,
696 				       msdig,
697 				       ms_per_transaction);
698 		} else {
699 			if (Iflag == 0)
700 				printf(" %5.2Lf %3.0Lf %5.2Lf ",
701 				       kb_per_transfer,
702 				       transfers_per_second,
703 				       mb_per_second);
704 			else {
705 				total_mb = total_bytes;
706 				total_mb /= 1024 * 1024;
707 
708 				printf(" %5.2Lf %3.1qu %5.2Lf ",
709 				       kb_per_transfer,
710 				       total_transfers,
711 				       total_mb);
712 			}
713 		}
714 	}
715 }
716 
717 static void
718 cpustats(void)
719 {
720 	register int state;
721 	double time;
722 
723 	time = 0.0;
724 
725 	for (state = 0; state < CPUSTATES; ++state)
726 		time += cur.cp_time[state];
727 	for (state = 0; state < CPUSTATES; ++state)
728 		printf(" %2.0f",
729 		       rint(100. * cur.cp_time[state] / (time ? time : 1)));
730 }
731 
732 static int
733 readvar(kvm_t *kd, const char *name, int nlid, void *ptr, size_t len)
734 {
735 	if (kd != NULL) {
736 		ssize_t nbytes;
737 
738 		nbytes = kvm_read(kd, nlid, ptr, len);
739 
740 		if (nbytes == 0) {
741 			warnx("kvm_read(%s): %s", name, kvm_geterr(kd));
742 			return (1);
743 		}
744 		if (nbytes != len) {
745 			warnx("kvm_read(%s): expected %lu bytes, got %ld bytes",
746 			      name, (unsigned long)len, (long)nbytes);
747 			return (1);
748 		}
749 	} else {
750 		size_t nlen = len;
751 
752 		if (sysctlbyname(name, ptr, &nlen, NULL, 0) == -1) {
753 			warn("sysctl(%s...) failed", name);
754 			return (1);
755 		}
756 		if (nlen != len) {
757 			warnx("sysctl(%s...): expected %lu, got %lu", name,
758 			      (unsigned long)len, (unsigned long)nlen);
759 			return (1);
760 		}
761 	}
762 	return (0);
763 }
764