iostat.c revision 82723 
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 82723 2001-09-01 07:40:19Z kris $
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 <signal.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
121struct 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
134struct statinfo cur, last;
135int num_devices;
136struct device_selection *dev_select;
137int maxshowdevs;
138int dflag = 0, Iflag = 0, Cflag = 0, Tflag = 0, oflag = 0, Kflag = 0;
139volatile sig_atomic_t phdr_flag = 0;
140
141/* local function declarations */
142static void usage(void);
143static void phdr(int signo);
144static void do_phdr();
145static void devstats(int perf_select, long double etime, int havelast);
146static void cpustats(void);
147static int readvar(kvm_t *kd, const char *name, int nlid, void *ptr,
148		   size_t len);
149
150static void
151usage(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
164int
165main(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	int headercount;
177	long generation;
178	int num_devices_specified;
179	int num_selected, num_selections;
180	long select_generation;
181	char **specified_devices;
182	devstat_select_mode select_mode;
183	int havelast = 0;
184
185	matches = NULL;
186	maxshowdevs = 3;
187
188	while ((c = getopt(argc, argv, "c:CdhIKM:n:N:ot:Tw:?")) != -1) {
189		switch(c) {
190			case 'c':
191				cflag++;
192				count = atoi(optarg);
193				if (count < 1)
194					errx(1, "count %d is < 1", count);
195				break;
196			case 'C':
197				Cflag++;
198				break;
199			case 'd':
200				dflag++;
201				break;
202			case 'h':
203				hflag++;
204				break;
205			case 'I':
206				Iflag++;
207				break;
208			case 'K':
209				Kflag++;
210				break;
211			case 'M':
212				memf = optarg;
213				break;
214			case 'n':
215				nflag++;
216				maxshowdevs = atoi(optarg);
217				if (maxshowdevs < 0)
218					errx(1, "number of devices %d is < 0",
219					     maxshowdevs);
220				break;
221			case 'N':
222				nlistf = optarg;
223				break;
224			case 'o':
225				oflag++;
226				break;
227			case 't':
228				tflag++;
229				if (devstat_buildmatch(optarg, &matches,
230						       &num_matches) != 0)
231					errx(1, "%s", devstat_errbuf);
232				break;
233			case 'T':
234				Tflag++;
235				break;
236			case 'w':
237				wflag++;
238				waittime = atoi(optarg);
239				if (waittime < 1)
240					errx(1, "wait time is < 1");
241				break;
242			default:
243				usage();
244				exit(1);
245				break;
246		}
247	}
248
249	argc -= optind;
250	argv += optind;
251
252	if (nlistf != NULL || memf != NULL) {
253		kd = kvm_openfiles(nlistf, memf, NULL, O_RDONLY, errbuf);
254
255		if (kd == NULL)
256			errx(1, "kvm_openfiles: %s", errbuf);
257
258		if (kvm_nlist(kd, namelist) == -1)
259			errx(1, "kvm_nlist: %s", kvm_geterr(kd));
260	}
261
262	/*
263	 * Make sure that the userland devstat version matches the kernel
264	 * devstat version.  If not, exit and print a message informing
265	 * the user of his mistake.
266	 */
267	if (devstat_checkversion(kd) < 0)
268		errx(1, "%s", devstat_errbuf);
269
270	/*
271	 * Make sure Tflag and/or Cflag are set if dflag == 0.  If dflag is
272	 * greater than 0, they may be 0 or non-zero.
273	 */
274	if (dflag == 0) {
275		Cflag = 1;
276		Tflag = 1;
277	}
278
279	/*
280	 * Figure out how many devices we should display.
281	 */
282	if (nflag == 0) {
283		if (oflag > 0) {
284			if ((dflag > 0) && (Cflag == 0) && (Tflag == 0))
285				maxshowdevs = 5;
286			else if ((dflag > 0) && (Tflag > 0) && (Cflag == 0))
287				maxshowdevs = 5;
288			else
289				maxshowdevs = 4;
290		} else {
291			if ((dflag > 0) && (Cflag == 0))
292				maxshowdevs = 4;
293			else
294				maxshowdevs = 3;
295		}
296	}
297
298	/* find out how many devices we have */
299	if ((num_devices = devstat_getnumdevs(kd)) < 0)
300		err(1, "can't get number of devices");
301
302	cur.dinfo = (struct devinfo *)malloc(sizeof(struct devinfo));
303	if (cur.dinfo == NULL)
304		err(1, "malloc failed");
305
306	last.dinfo = (struct devinfo *)malloc(sizeof(struct devinfo));
307	if (last.dinfo == NULL)
308		err(1, "malloc failed");
309
310	bzero(cur.dinfo, sizeof(struct devinfo));
311	bzero(last.dinfo, sizeof(struct devinfo));
312
313	/*
314	 * Grab all the devices.  We don't look to see if the list has
315	 * changed here, since it almost certainly has.  We only look for
316	 * errors.
317	 */
318	if (devstat_getdevs(kd, &cur) == -1)
319		errx(1, "%s", devstat_errbuf);
320
321	num_devices = cur.dinfo->numdevs;
322	generation = cur.dinfo->generation;
323
324	/*
325	 * If the user specified any devices on the command line, see if
326	 * they are in the list of devices we have now.
327	 */
328	specified_devices = (char **)malloc(sizeof(char *));
329	if (specified_devices == NULL)
330		err(1, "malloc failed");
331
332	for (num_devices_specified = 0; *argv; ++argv) {
333		if (isdigit(**argv))
334			break;
335		num_devices_specified++;
336		specified_devices = (char **)realloc(specified_devices,
337						     sizeof(char *) *
338						     num_devices_specified);
339		if (specified_devices == NULL)
340			err(1, "realloc failed");
341
342		specified_devices[num_devices_specified - 1] = *argv;
343
344	}
345	if (nflag == 0 && maxshowdevs < num_devices_specified)
346		maxshowdevs = num_devices_specified;
347
348	dev_select = NULL;
349
350	if ((num_devices_specified == 0) && (num_matches == 0))
351		select_mode = DS_SELECT_ADD;
352	else
353		select_mode = DS_SELECT_ONLY;
354
355	/*
356	 * At this point, selectdevs will almost surely indicate that the
357	 * device list has changed, so we don't look for return values of 0
358	 * or 1.  If we get back -1, though, there is an error.
359	 */
360	if (devstat_selectdevs(&dev_select, &num_selected,
361			       &num_selections, &select_generation, generation,
362			       cur.dinfo->devices, num_devices, matches,
363			       num_matches, specified_devices,
364			       num_devices_specified, select_mode, maxshowdevs,
365			       hflag) == -1)
366		errx(1, "%s", devstat_errbuf);
367
368	/*
369	 * Look for the traditional wait time and count arguments.
370	 */
371	if (*argv) {
372		waittime = atoi(*argv);
373
374		/* Let the user know he goofed, but keep going anyway */
375		if (wflag != 0)
376			warnx("discarding previous wait interval, using"
377			      " %d instead", waittime);
378		wflag++;
379
380		if (*++argv) {
381			count = atoi(*argv);
382			if (cflag != 0)
383				warnx("discarding previous count, using %d"
384				      " instead", count);
385			cflag++;
386		} else
387			count = -1;
388	}
389
390	/*
391	 * If the user specified a count, but not an interval, we default
392	 * to an interval of 1 second.
393	 */
394	if ((wflag == 0) && (cflag > 0))
395		waittime = 1;
396
397	/*
398	 * If the user specified a wait time, but not a count, we want to
399	 * go on ad infinitum.  This can be redundant if the user uses the
400	 * traditional method of specifying the wait, since in that case we
401	 * already set count = -1 above.  Oh well.
402	 */
403	if ((wflag > 0) && (cflag == 0))
404		count = -1;
405
406	bzero(&cur.cp_time, sizeof(cur.cp_time));
407	cur.tk_nout = 0;
408	cur.tk_nin = 0;
409
410	/*
411	 * Set the busy time to the system boot time, so the stats are
412	 * calculated since system boot.
413	 */
414	if (readvar(kd, "kern.boottime", X_BOOTTIME, &cur.busy_time,
415		    sizeof(cur.busy_time)) != 0)
416		exit(1);
417
418	/*
419	 * If the user stops the program (control-Z) and then resumes it,
420	 * print out the header again.
421	 */
422	(void)signal(SIGCONT, phdr);
423
424	for (headercount = 1;;) {
425		struct devinfo *tmp_dinfo;
426		long tmp;
427		long double etime;
428
429		if (Tflag > 0) {
430			if ((readvar(kd, "kern.tty_nin", X_TK_NIN, &cur.tk_nin,
431			     sizeof(cur.tk_nin)) != 0)
432			 || (readvar(kd, "kern.tty_nout", X_TK_NOUT,
433			     &cur.tk_nout, sizeof(cur.tk_nout))!= 0)) {
434				Tflag = 0;
435				warnx("disabling TTY statistics");
436			}
437		 }
438
439		if (phdr_flag) {
440			phdr_flag = 0;
441			do_phdr();
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			do_phdr();
454			headercount = 20;
455		}
456
457		tmp_dinfo = last.dinfo;
458		last.dinfo = cur.dinfo;
459		cur.dinfo = tmp_dinfo;
460
461		last.busy_time = cur.busy_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				do_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				do_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 = devstat_compute_etime(cur.busy_time, last.busy_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 (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 (Cflag > 0)
565			cpustats();
566
567		printf("\n");
568		fflush(stdout);
569
570		if (count >= 0 && --count <= 0)
571			break;
572
573		sleep(waittime);
574		havelast = 1;
575	}
576
577	exit(0);
578}
579
580static void
581phdr(int signo)
582{
583
584	phdr_flag = 1;
585}
586
587static void
588do_phdr()
589{
590	register int i;
591	int printed;
592
593	if (Tflag > 0)
594		(void)printf("      tty");
595	for (i = 0, printed=0;(i < num_devices) && (printed < maxshowdevs);i++){
596		int di;
597		if ((dev_select[i].selected != 0)
598		 && (dev_select[i].selected <= maxshowdevs)) {
599			di = dev_select[i].position;
600			if (oflag > 0)
601				(void)printf("%12.6s%d ",
602					    cur.dinfo->devices[di].device_name,
603					    cur.dinfo->devices[di].unit_number);
604			else
605				printf("%15.6s%d ",
606					    cur.dinfo->devices[di].device_name,
607					    cur.dinfo->devices[di].unit_number);
608			printed++;
609		}
610	}
611	if (Cflag > 0)
612		(void)printf("            cpu\n");
613	else
614		(void)printf("\n");
615
616	if (Tflag > 0)
617		(void)printf(" tin tout");
618
619	for (i=0, printed = 0;(i < num_devices) && (printed < maxshowdevs);i++){
620		if ((dev_select[i].selected != 0)
621		 && (dev_select[i].selected <= maxshowdevs)) {
622			if (oflag > 0) {
623				if (Iflag == 0)
624					(void)printf(" sps tps msps ");
625				else
626					(void)printf(" blk xfr msps ");
627			} else {
628				if (Iflag == 0)
629					printf("  KB/t tps  MB/s ");
630				else
631					printf("  KB/t xfrs   MB ");
632			}
633			printed++;
634		}
635	}
636	if (Cflag > 0)
637		(void)printf(" us ni sy in id\n");
638	else
639		printf("\n");
640}
641
642static void
643devstats(int perf_select, long double etime, int havelast)
644{
645	register int dn;
646	long double transfers_per_second;
647	long double kb_per_transfer, mb_per_second;
648	u_int64_t total_bytes, total_transfers, total_blocks;
649	long double total_mb;
650	long double blocks_per_second, ms_per_transaction;
651
652	for (dn = 0; dn < num_devices; dn++) {
653		int di;
654
655		if (((perf_select == 0) && (dev_select[dn].selected == 0))
656		 || (dev_select[dn].selected > maxshowdevs))
657			continue;
658
659		di = dev_select[dn].position;
660
661		if (devstat_compute_statistics(&cur.dinfo->devices[di],
662		    havelast ? &last.dinfo->devices[di] : NULL, etime,
663		    DSM_TOTAL_BYTES, &total_bytes,
664		    DSM_TOTAL_TRANSFERS, &total_transfers,
665		    DSM_TOTAL_BLOCKS, &total_blocks,
666		    DSM_KB_PER_TRANSFER, &kb_per_transfer,
667		    DSM_TRANSFERS_PER_SECOND, &transfers_per_second,
668		    DSM_MB_PER_SECOND, &mb_per_second,
669		    DSM_BLOCKS_PER_SECOND, &blocks_per_second,
670		    DSM_MS_PER_TRANSACTION, &ms_per_transaction,
671		    DSM_NONE) != 0)
672			errx(1, "%s", devstat_errbuf);
673
674		if (perf_select != 0) {
675			dev_select[dn].bytes = total_bytes;
676			if ((dev_select[dn].selected == 0)
677			 || (dev_select[dn].selected > maxshowdevs))
678				continue;
679		}
680
681		if (Kflag) {
682			int block_size = cur.dinfo->devices[di].block_size;
683			total_blocks = total_blocks * (block_size ?
684						       block_size : 512) / 1024;
685		}
686
687		if (oflag > 0) {
688			int msdig = (ms_per_transaction < 100.0) ? 1 : 0;
689
690			if (Iflag == 0)
691				printf("%4.0Lf%4.0Lf%5.*Lf ",
692				       blocks_per_second,
693				       transfers_per_second,
694				       msdig,
695				       ms_per_transaction);
696			else
697				printf("%4.1qu%4.1qu%5.*Lf ",
698				       total_blocks,
699				       total_transfers,
700				       msdig,
701				       ms_per_transaction);
702		} else {
703			if (Iflag == 0)
704				printf(" %5.2Lf %3.0Lf %5.2Lf ",
705				       kb_per_transfer,
706				       transfers_per_second,
707				       mb_per_second);
708			else {
709				total_mb = total_bytes;
710				total_mb /= 1024 * 1024;
711
712				printf(" %5.2Lf %3.1qu %5.2Lf ",
713				       kb_per_transfer,
714				       total_transfers,
715				       total_mb);
716			}
717		}
718	}
719}
720
721static void
722cpustats(void)
723{
724	register int state;
725	double time;
726
727	time = 0.0;
728
729	for (state = 0; state < CPUSTATES; ++state)
730		time += cur.cp_time[state];
731	for (state = 0; state < CPUSTATES; ++state)
732		printf("%3.0f",
733		       rint(100. * cur.cp_time[state] / (time ? time : 1)));
734}
735
736static int
737readvar(kvm_t *kd, const char *name, int nlid, void *ptr, size_t len)
738{
739	if (kd != NULL) {
740		ssize_t nbytes;
741
742		nbytes = kvm_read(kd, nlid, ptr, len);
743
744		if (nbytes == 0) {
745			warnx("kvm_read(%s): %s", name, kvm_geterr(kd));
746			return (1);
747		}
748		if (nbytes != len) {
749			warnx("kvm_read(%s): expected %lu bytes, got %ld bytes",
750			      name, (unsigned long)len, (long)nbytes);
751			return (1);
752		}
753	} else {
754		size_t nlen = len;
755
756		if (sysctlbyname(name, ptr, &nlen, NULL, 0) == -1) {
757			warn("sysctl(%s...) failed", name);
758			return (1);
759		}
760		if (nlen != len) {
761			warnx("sysctl(%s...): expected %lu, got %lu", name,
762			      (unsigned long)len, (unsigned long)nlen);
763			return (1);
764		}
765	}
766	return (0);
767}
768