iostat.c revision 112288
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 112288 2003-03-15 21:59:06Z phk $
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
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;
138volatile sig_atomic_t headercount;
139int dflag = 0, Iflag = 0, Cflag = 0, Tflag = 0, oflag = 0, Kflag = 0;
140
141/* local function declarations */
142static void usage(void);
143static void needhdr(int signo);
144static void phdr(void);
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	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 */
575void
576needhdr(int signo)
577{
578
579        headercount = 1;
580}
581
582static void
583phdr(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
638static void
639devstats(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
717static void
718cpustats(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
732static int
733readvar(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