iostat.c revision 82168 
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: head/usr.sbin/iostat/iostat.c 82168 2001-08-23 03:19:54Z ken $
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/dkstat.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 <stdio.h>
113#include <stdlib.h>
114#include <string.h>
115#include <unistd.h>
116#include <limits.h>
117#include <devstat.h>
118#include <math.h>
119
120struct nlist namelist[] = {
121#define X_TK_NIN	0
122	{ "_tk_nin" },
123#define X_TK_NOUT	1
124	{ "_tk_nout" },
125#define X_CP_TIME	2
126	{ "_cp_time" },
127#define X_BOOTTIME	3
128	{ "_boottime" },
129#define X_END		3
130	{ NULL },
131};
132
133struct statinfo cur, last;
134int num_devices;
135struct device_selection *dev_select;
136int maxshowdevs;
137int dflag = 0, Iflag = 0, Cflag = 0, Tflag = 0, oflag = 0, Kflag = 0;
138
139/* local function declarations */
140static void usage(void);
141static void phdr(int signo);
142static void devstats(int perf_select, long double etime, int havelast);
143static void cpustats(void);
144static int readvar(kvm_t *kd, const char *name, int nlid, void *ptr,
145		   size_t len);
146
147static void
148usage(void)
149{
150	/*
151	 * We also support the following 'traditional' syntax:
152	 * iostat [drives] [wait [count]]
153	 * This isn't mentioned in the man page, or the usage statement,
154	 * but it is supported.
155	 */
156	fprintf(stderr, "usage: iostat [-CdhIKoT?] [-c count] [-M core]"
157		" [-n devs] [-N system]\n"
158		"\t      [-t type,if,pass] [-w wait] [drives]\n");
159}
160
161int
162main(int argc, char **argv)
163{
164	int c;
165	register int i;
166	int tflag = 0, hflag = 0, cflag = 0, wflag = 0, nflag = 0;
167	int count = 0, waittime = 0;
168	char *memf = NULL, *nlistf = NULL;
169	struct devstat_match *matches;
170	int num_matches = 0;
171        char errbuf[_POSIX2_LINE_MAX];
172	kvm_t *kd = NULL;
173	int headercount;
174	long generation;
175	int num_devices_specified;
176	int num_selected, num_selections;
177	long select_generation;
178	char **specified_devices;
179	devstat_select_mode select_mode;
180	int havelast = 0;
181
182	matches = NULL;
183	maxshowdevs = 3;
184
185	while ((c = getopt(argc, argv, "c:CdhIKM:n:N:ot:Tw:?")) != -1) {
186		switch(c) {
187			case 'c':
188				cflag++;
189				count = atoi(optarg);
190				if (count < 1)
191					errx(1, "count %d is < 1", count);
192				break;
193			case 'C':
194				Cflag++;
195				break;
196			case 'd':
197				dflag++;
198				break;
199			case 'h':
200				hflag++;
201				break;
202			case 'I':
203				Iflag++;
204				break;
205			case 'K':
206				Kflag++;
207				break;
208			case 'M':
209				memf = optarg;
210				break;
211			case 'n':
212				nflag++;
213				maxshowdevs = atoi(optarg);
214				if (maxshowdevs < 0)
215					errx(1, "number of devices %d is < 0",
216					     maxshowdevs);
217				break;
218			case 'N':
219				nlistf = optarg;
220				break;
221			case 'o':
222				oflag++;
223				break;
224			case 't':
225				tflag++;
226				if (devstat_buildmatch(optarg, &matches,
227						       &num_matches) != 0)
228					errx(1, "%s", devstat_errbuf);
229				break;
230			case 'T':
231				Tflag++;
232				break;
233			case 'w':
234				wflag++;
235				waittime = atoi(optarg);
236				if (waittime < 1)
237					errx(1, "wait time is < 1");
238				break;
239			default:
240				usage();
241				exit(1);
242				break;
243		}
244	}
245
246	argc -= optind;
247	argv += optind;
248
249	if (nlistf != NULL || memf != NULL) {
250		kd = kvm_openfiles(nlistf, memf, NULL, O_RDONLY, errbuf);
251
252		if (kd == NULL)
253			errx(1, "kvm_openfiles: %s", errbuf);
254
255		if (kvm_nlist(kd, namelist) == -1)
256			errx(1, "kvm_nlist: %s", kvm_geterr(kd));
257	}
258
259	/*
260	 * Make sure that the userland devstat version matches the kernel
261	 * devstat version.  If not, exit and print a message informing
262	 * the user of his mistake.
263	 */
264	if (devstat_checkversion(kd) < 0)
265		errx(1, "%s", devstat_errbuf);
266
267	/*
268	 * Make sure Tflag and/or Cflag are set if dflag == 0.  If dflag is
269	 * greater than 0, they may be 0 or non-zero.
270	 */
271	if (dflag == 0) {
272		Cflag = 1;
273		Tflag = 1;
274	}
275
276	/*
277	 * Figure out how many devices we should display.
278	 */
279	if (nflag == 0) {
280		if (oflag > 0) {
281			if ((dflag > 0) && (Cflag == 0) && (Tflag == 0))
282				maxshowdevs = 5;
283			else if ((dflag > 0) && (Tflag > 0) && (Cflag == 0))
284				maxshowdevs = 5;
285			else
286				maxshowdevs = 4;
287		} else {
288			if ((dflag > 0) && (Cflag == 0))
289				maxshowdevs = 4;
290			else
291				maxshowdevs = 3;
292		}
293	}
294
295	/* find out how many devices we have */
296	if ((num_devices = devstat_getnumdevs(kd)) < 0)
297		err(1, "can't get number of devices");
298
299	cur.dinfo = (struct devinfo *)malloc(sizeof(struct devinfo));
300	if (cur.dinfo == NULL)
301		err(1, "malloc failed");
302
303	last.dinfo = (struct devinfo *)malloc(sizeof(struct devinfo));
304	if (last.dinfo == NULL)
305		err(1, "malloc failed");
306
307	bzero(cur.dinfo, sizeof(struct devinfo));
308	bzero(last.dinfo, sizeof(struct devinfo));
309
310	/*
311	 * Grab all the devices.  We don't look to see if the list has
312	 * changed here, since it almost certainly has.  We only look for
313	 * errors.
314	 */
315	if (devstat_getdevs(kd, &cur) == -1)
316		errx(1, "%s", devstat_errbuf);
317
318	num_devices = cur.dinfo->numdevs;
319	generation = cur.dinfo->generation;
320
321	/*
322	 * If the user specified any devices on the command line, see if
323	 * they are in the list of devices we have now.
324	 */
325	specified_devices = (char **)malloc(sizeof(char *));
326	if (specified_devices == NULL)
327		err(1, "malloc failed");
328
329	for (num_devices_specified = 0; *argv; ++argv) {
330		if (isdigit(**argv))
331			break;
332		num_devices_specified++;
333		specified_devices = (char **)realloc(specified_devices,
334						     sizeof(char *) *
335						     num_devices_specified);
336		if (specified_devices == NULL)
337			err(1, "realloc failed");
338
339		specified_devices[num_devices_specified - 1] = *argv;
340
341	}
342	if (nflag == 0 && maxshowdevs < num_devices_specified)
343		maxshowdevs = num_devices_specified;
344
345	dev_select = NULL;
346
347	if ((num_devices_specified == 0) && (num_matches == 0))
348		select_mode = DS_SELECT_ADD;
349	else
350		select_mode = DS_SELECT_ONLY;
351
352	/*
353	 * At this point, selectdevs will almost surely indicate that the
354	 * device list has changed, so we don't look for return values of 0
355	 * or 1.  If we get back -1, though, there is an error.
356	 */
357	if (devstat_selectdevs(&dev_select, &num_selected,
358			       &num_selections, &select_generation, generation,
359			       cur.dinfo->devices, num_devices, matches,
360			       num_matches, specified_devices,
361			       num_devices_specified, select_mode, maxshowdevs,
362			       hflag) == -1)
363		errx(1, "%s", devstat_errbuf);
364
365	/*
366	 * Look for the traditional wait time and count arguments.
367	 */
368	if (*argv) {
369		waittime = atoi(*argv);
370
371		/* Let the user know he goofed, but keep going anyway */
372		if (wflag != 0)
373			warnx("discarding previous wait interval, using"
374			      " %d instead", waittime);
375		wflag++;
376
377		if (*++argv) {
378			count = atoi(*argv);
379			if (cflag != 0)
380				warnx("discarding previous count, using %d"
381				      " instead", count);
382			cflag++;
383		} else
384			count = -1;
385	}
386
387	/*
388	 * If the user specified a count, but not an interval, we default
389	 * to an interval of 1 second.
390	 */
391	if ((wflag == 0) && (cflag > 0))
392		waittime = 1;
393
394	/*
395	 * If the user specified a wait time, but not a count, we want to
396	 * go on ad infinitum.  This can be redundant if the user uses the
397	 * traditional method of specifying the wait, since in that case we
398	 * already set count = -1 above.  Oh well.
399	 */
400	if ((wflag > 0) && (cflag == 0))
401		count = -1;
402
403	bzero(&cur.cp_time, sizeof(cur.cp_time));
404	cur.tk_nout = 0;
405	cur.tk_nin = 0;
406
407	/*
408	 * Set the busy time to the system boot time, so the stats are
409	 * calculated since system boot.
410	 */
411	if (readvar(kd, "kern.boottime", X_BOOTTIME, &cur.busy_time,
412		    sizeof(cur.busy_time)) != 0)
413		exit(1);
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, phdr);
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(0);
446			headercount = 20;
447		}
448
449		tmp_dinfo = last.dinfo;
450		last.dinfo = cur.dinfo;
451		cur.dinfo = tmp_dinfo;
452
453		last.busy_time = cur.busy_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(0);
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(0);
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 = devstat_compute_etime(cur.busy_time, last.busy_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
572static void
573phdr(int signo)
574{
575	register int i;
576	int printed;
577
578	if (Tflag > 0)
579		(void)printf("      tty");
580	for (i = 0, printed=0;(i < num_devices) && (printed < maxshowdevs);i++){
581		int di;
582		if ((dev_select[i].selected != 0)
583		 && (dev_select[i].selected <= maxshowdevs)) {
584			di = dev_select[i].position;
585			if (oflag > 0)
586				(void)printf("%12.6s%d ",
587					    cur.dinfo->devices[di].device_name,
588					    cur.dinfo->devices[di].unit_number);
589			else
590				printf("%15.6s%d ",
591					    cur.dinfo->devices[di].device_name,
592					    cur.dinfo->devices[di].unit_number);
593			printed++;
594		}
595	}
596	if (Cflag > 0)
597		(void)printf("            cpu\n");
598	else
599		(void)printf("\n");
600
601	if (Tflag > 0)
602		(void)printf(" tin tout");
603
604	for (i=0, printed = 0;(i < num_devices) && (printed < maxshowdevs);i++){
605		if ((dev_select[i].selected != 0)
606		 && (dev_select[i].selected <= maxshowdevs)) {
607			if (oflag > 0) {
608				if (Iflag == 0)
609					(void)printf(" sps tps msps ");
610				else
611					(void)printf(" blk xfr msps ");
612			} else {
613				if (Iflag == 0)
614					printf("  KB/t tps  MB/s ");
615				else
616					printf("  KB/t xfrs   MB ");
617			}
618			printed++;
619		}
620	}
621	if (Cflag > 0)
622		(void)printf(" us ni sy in id\n");
623	else
624		printf("\n");
625
626}
627
628static void
629devstats(int perf_select, long double etime, int havelast)
630{
631	register int dn;
632	long double transfers_per_second;
633	long double kb_per_transfer, mb_per_second;
634	u_int64_t total_bytes, total_transfers, total_blocks;
635	long double total_mb;
636	long double blocks_per_second, ms_per_transaction;
637
638	for (dn = 0; dn < num_devices; dn++) {
639		int di;
640
641		if (((perf_select == 0) && (dev_select[dn].selected == 0))
642		 || (dev_select[dn].selected > maxshowdevs))
643			continue;
644
645		di = dev_select[dn].position;
646
647		if (devstat_compute_statistics(&cur.dinfo->devices[di],
648		    havelast ? &last.dinfo->devices[di] : NULL, etime,
649		    DSM_TOTAL_BYTES, &total_bytes,
650		    DSM_TOTAL_TRANSFERS, &total_transfers,
651		    DSM_TOTAL_BLOCKS, &total_blocks,
652		    DSM_KB_PER_TRANSFER, &kb_per_transfer,
653		    DSM_TRANSFERS_PER_SECOND, &transfers_per_second,
654		    DSM_MB_PER_SECOND, &mb_per_second,
655		    DSM_BLOCKS_PER_SECOND, &blocks_per_second,
656		    DSM_MS_PER_TRANSACTION, &ms_per_transaction,
657		    DSM_NONE) != 0)
658			errx(1, "%s", devstat_errbuf);
659
660		if (perf_select != 0) {
661			dev_select[dn].bytes = total_bytes;
662			if ((dev_select[dn].selected == 0)
663			 || (dev_select[dn].selected > maxshowdevs))
664				continue;
665		}
666
667		if (Kflag) {
668			int block_size = cur.dinfo->devices[di].block_size;
669			total_blocks = total_blocks * (block_size ?
670						       block_size : 512) / 1024;
671		}
672
673		if (oflag > 0) {
674			int msdig = (ms_per_transaction < 100.0) ? 1 : 0;
675
676			if (Iflag == 0)
677				printf("%4.0Lf%4.0Lf%5.*Lf ",
678				       blocks_per_second,
679				       transfers_per_second,
680				       msdig,
681				       ms_per_transaction);
682			else
683				printf("%4.1qu%4.1qu%5.*Lf ",
684				       total_blocks,
685				       total_transfers,
686				       msdig,
687				       ms_per_transaction);
688		} else {
689			if (Iflag == 0)
690				printf(" %5.2Lf %3.0Lf %5.2Lf ",
691				       kb_per_transfer,
692				       transfers_per_second,
693				       mb_per_second);
694			else {
695				total_mb = total_bytes;
696				total_mb /= 1024 * 1024;
697
698				printf(" %5.2Lf %3.1qu %5.2Lf ",
699				       kb_per_transfer,
700				       total_transfers,
701				       total_mb);
702			}
703		}
704	}
705}
706
707static void
708cpustats(void)
709{
710	register int state;
711	double time;
712
713	time = 0.0;
714
715	for (state = 0; state < CPUSTATES; ++state)
716		time += cur.cp_time[state];
717	for (state = 0; state < CPUSTATES; ++state)
718		printf("%3.0f",
719		       rint(100. * cur.cp_time[state] / (time ? time : 1)));
720}
721
722static int
723readvar(kvm_t *kd, const char *name, int nlid, void *ptr, size_t len)
724{
725	if (kd != NULL) {
726		ssize_t nbytes;
727
728		nbytes = kvm_read(kd, nlid, ptr, len);
729
730		if (nbytes == 0) {
731			warnx("kvm_read(%s): %s", name, kvm_geterr(kd));
732			return (1);
733		}
734		if (nbytes != len) {
735			warnx("kvm_read(%s): expected %lu bytes, got %ld bytes",
736			      name, (unsigned long)len, (long)nbytes);
737			return (1);
738		}
739	} else {
740		size_t nlen = len;
741
742		if (sysctlbyname(name, ptr, &nlen, NULL, 0) == -1) {
743			warn("sysctl(%s...) failed", name);
744			return (1);
745		}
746		if (nlen != len) {
747			warnx("sysctl(%s...): expected %lu, got %lu", name,
748			      (unsigned long)len, (unsigned long)nlen);
749			return (1);
750		}
751	}
752	return (0);
753}
754