xref: /freebsd/usr.sbin/iostat/iostat.c (revision 1f4bcc459a76b7aa664f3fd557684cd0ba6da352)
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  * 4. Neither the name of the University nor the names of its contributors
47  *    may be used to endorse or promote products derived from this software
48  *    without specific prior written permission.
49  *
50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60  * SUCH DAMAGE.
61  */
62 /*
63  * Ideas for the new iostat statistics output modes taken from the NetBSD
64  * version of iostat:
65  */
66 /*
67  * Copyright (c) 1996 John M. Vinopal
68  * All rights reserved.
69  *
70  * Redistribution and use in source and binary forms, with or without
71  * modification, are permitted provided that the following conditions
72  * are met:
73  * 1. Redistributions of source code must retain the above copyright
74  *    notice, this list of conditions and the following disclaimer.
75  * 2. Redistributions in binary form must reproduce the above copyright
76  *    notice, this list of conditions and the following disclaimer in the
77  *    documentation and/or other materials provided with the distribution.
78  * 3. All advertising materials mentioning features or use of this software
79  *    must display the following acknowledgement:
80  *      This product includes software developed for the NetBSD Project
81  *      by John M. Vinopal.
82  * 4. The name of the author may not be used to endorse or promote products
83  *    derived from this software without specific prior written permission.
84  *
85  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
86  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
87  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
88  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
89  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
90  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
91  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
92  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
93  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
94  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
95  * SUCH DAMAGE.
96  */
97 
98 
99 #include <sys/param.h>
100 #include <sys/errno.h>
101 #include <sys/resource.h>
102 #include <sys/sysctl.h>
103 
104 #include <ctype.h>
105 #include <devstat.h>
106 #include <err.h>
107 #include <fcntl.h>
108 #include <inttypes.h>
109 #include <kvm.h>
110 #include <limits.h>
111 #include <math.h>
112 #include <nlist.h>
113 #include <signal.h>
114 #include <stdio.h>
115 #include <stdlib.h>
116 #include <string.h>
117 #include <termios.h>
118 #include <unistd.h>
119 
120 struct nlist namelist[] = {
121 #define X_TTY_NIN	0
122 	{ "_tty_nin" },
123 #define X_TTY_NOUT	1
124 	{ "_tty_nout" },
125 #define X_BOOTTIME	2
126 	{ "_boottime" },
127 #define X_END		2
128 	{ NULL },
129 };
130 
131 #define	IOSTAT_DEFAULT_ROWS	20	/* Traditional default `wrows' */
132 
133 struct statinfo cur, last;
134 int num_devices;
135 struct device_selection *dev_select;
136 int maxshowdevs;
137 volatile sig_atomic_t headercount;
138 volatile sig_atomic_t wresized;		/* Tty resized, when non-zero. */
139 volatile sig_atomic_t alarm_rang;
140 volatile sig_atomic_t return_requested;
141 unsigned short wrows;			/* Current number of tty rows. */
142 int dflag = 0, Iflag = 0, Cflag = 0, Tflag = 0, oflag = 0, Kflag = 0;
143 int xflag = 0, zflag = 0;
144 
145 /* local function declarations */
146 static void usage(void);
147 static void needhdr(int signo);
148 static void needresize(int signo);
149 static void needreturn(int signo);
150 static void alarm_clock(int signo);
151 static void doresize(void);
152 static void phdr(void);
153 static void devstats(int perf_select, long double etime, int havelast);
154 static void cpustats(void);
155 static int readvar(kvm_t *kd, const char *name, int nlid, void *ptr,
156 		   size_t len);
157 
158 static void
159 usage(void)
160 {
161 	/*
162 	 * We also support the following 'traditional' syntax:
163 	 * iostat [drives] [wait [count]]
164 	 * This isn't mentioned in the man page, or the usage statement,
165 	 * but it is supported.
166 	 */
167 	fprintf(stderr, "usage: iostat [-CdhIKoTxz?] [-c count] [-M core]"
168 		" [-n devs] [-N system]\n"
169 		"\t      [-t type,if,pass] [-w wait] [drives]\n");
170 }
171 
172 int
173 main(int argc, char **argv)
174 {
175 	int c, i;
176 	int tflag = 0, hflag = 0, cflag = 0, wflag = 0, nflag = 0;
177 	int count = 0, waittime = 0;
178 	char *memf = NULL, *nlistf = NULL;
179 	struct devstat_match *matches;
180 	struct itimerval alarmspec;
181 	int num_matches = 0;
182 	char errbuf[_POSIX2_LINE_MAX];
183 	kvm_t *kd = NULL;
184 	long generation;
185 	int num_devices_specified;
186 	int num_selected, num_selections;
187 	long select_generation;
188 	char **specified_devices;
189 	devstat_select_mode select_mode;
190 	float f;
191 	int havelast = 0;
192 
193 	matches = NULL;
194 	maxshowdevs = 3;
195 
196 	while ((c = getopt(argc, argv, "c:CdhIKM:n:N:ot:Tw:xz?")) != -1) {
197 		switch(c) {
198 			case 'c':
199 				cflag++;
200 				count = atoi(optarg);
201 				if (count < 1)
202 					errx(1, "count %d is < 1", count);
203 				break;
204 			case 'C':
205 				Cflag++;
206 				break;
207 			case 'd':
208 				dflag++;
209 				break;
210 			case 'h':
211 				hflag++;
212 				break;
213 			case 'I':
214 				Iflag++;
215 				break;
216 			case 'K':
217 				Kflag++;
218 				break;
219 			case 'M':
220 				memf = optarg;
221 				break;
222 			case 'n':
223 				nflag++;
224 				maxshowdevs = atoi(optarg);
225 				if (maxshowdevs < 0)
226 					errx(1, "number of devices %d is < 0",
227 					     maxshowdevs);
228 				break;
229 			case 'N':
230 				nlistf = optarg;
231 				break;
232 			case 'o':
233 				oflag++;
234 				break;
235 			case 't':
236 				tflag++;
237 				if (devstat_buildmatch(optarg, &matches,
238 						       &num_matches) != 0)
239 					errx(1, "%s", devstat_errbuf);
240 				break;
241 			case 'T':
242 				Tflag++;
243 				break;
244 			case 'w':
245 				wflag++;
246 				f = atof(optarg);
247 				waittime = f * 1000;
248 				if (waittime < 1)
249 					errx(1, "wait time is < 1ms");
250 				break;
251 			case 'x':
252 				xflag++;
253 				break;
254 			case 'z':
255 				zflag++;
256 				break;
257 			default:
258 				usage();
259 				exit(1);
260 				break;
261 		}
262 	}
263 
264 	argc -= optind;
265 	argv += optind;
266 
267 	if (nlistf != NULL || memf != NULL) {
268 		kd = kvm_openfiles(nlistf, memf, NULL, O_RDONLY, errbuf);
269 
270 		if (kd == NULL)
271 			errx(1, "kvm_openfiles: %s", errbuf);
272 
273 		if (kvm_nlist(kd, namelist) == -1)
274 			errx(1, "kvm_nlist: %s", kvm_geterr(kd));
275 	}
276 
277 	/*
278 	 * Make sure that the userland devstat version matches the kernel
279 	 * devstat version.  If not, exit and print a message informing
280 	 * the user of his mistake.
281 	 */
282 	if (devstat_checkversion(kd) < 0)
283 		errx(1, "%s", devstat_errbuf);
284 
285 	/*
286 	 * Make sure Tflag and/or Cflag are set if dflag == 0.  If dflag is
287 	 * greater than 0, they may be 0 or non-zero.
288 	 */
289 	if (dflag == 0 && xflag == 0) {
290 		Cflag = 1;
291 		Tflag = 1;
292 	}
293 
294 	/* find out how many devices we have */
295 	if ((num_devices = devstat_getnumdevs(kd)) < 0)
296 		err(1, "can't get number of devices");
297 
298 	/*
299 	 * Figure out how many devices we should display.
300 	 */
301 	if (nflag == 0) {
302 		if (xflag > 0)
303 			maxshowdevs = num_devices;
304 		else if (oflag > 0) {
305 			if ((dflag > 0) && (Cflag == 0) && (Tflag == 0))
306 				maxshowdevs = 5;
307 			else if ((dflag > 0) && (Tflag > 0) && (Cflag == 0))
308 				maxshowdevs = 5;
309 			else
310 				maxshowdevs = 4;
311 		} else {
312 			if ((dflag > 0) && (Cflag == 0))
313 				maxshowdevs = 4;
314 			else
315 				maxshowdevs = 3;
316 		}
317 	}
318 
319 	cur.dinfo = (struct devinfo *)calloc(1, sizeof(struct devinfo));
320 	if (cur.dinfo == NULL)
321 		err(1, "calloc failed");
322 
323 	last.dinfo = (struct devinfo *)calloc(1, sizeof(struct devinfo));
324 	if (last.dinfo == NULL)
325 		err(1, "calloc failed");
326 
327 	/*
328 	 * Grab all the devices.  We don't look to see if the list has
329 	 * changed here, since it almost certainly has.  We only look for
330 	 * errors.
331 	 */
332 	if (devstat_getdevs(kd, &cur) == -1)
333 		errx(1, "%s", devstat_errbuf);
334 
335 	num_devices = cur.dinfo->numdevs;
336 	generation = cur.dinfo->generation;
337 
338 	/*
339 	 * If the user specified any devices on the command line, see if
340 	 * they are in the list of devices we have now.
341 	 */
342 	specified_devices = (char **)malloc(sizeof(char *));
343 	if (specified_devices == NULL)
344 		err(1, "malloc failed");
345 
346 	for (num_devices_specified = 0; *argv; ++argv) {
347 		if (isdigit(**argv))
348 			break;
349 		num_devices_specified++;
350 		specified_devices = (char **)realloc(specified_devices,
351 						     sizeof(char *) *
352 						     num_devices_specified);
353 		if (specified_devices == NULL)
354 			err(1, "realloc failed");
355 
356 		specified_devices[num_devices_specified - 1] = *argv;
357 
358 	}
359 	if (nflag == 0 && maxshowdevs < num_devices_specified)
360 		maxshowdevs = num_devices_specified;
361 
362 	dev_select = NULL;
363 
364 	if ((num_devices_specified == 0) && (num_matches == 0))
365 		select_mode = DS_SELECT_ADD;
366 	else
367 		select_mode = DS_SELECT_ONLY;
368 
369 	/*
370 	 * At this point, selectdevs will almost surely indicate that the
371 	 * device list has changed, so we don't look for return values of 0
372 	 * or 1.  If we get back -1, though, there is an error.
373 	 */
374 	if (devstat_selectdevs(&dev_select, &num_selected,
375 			       &num_selections, &select_generation, generation,
376 			       cur.dinfo->devices, num_devices, matches,
377 			       num_matches, specified_devices,
378 			       num_devices_specified, select_mode, maxshowdevs,
379 			       hflag) == -1)
380 		errx(1, "%s", devstat_errbuf);
381 
382 	/*
383 	 * Look for the traditional wait time and count arguments.
384 	 */
385 	if (*argv) {
386 		f = atof(*argv);
387 		waittime = f * 1000;
388 
389 		/* Let the user know he goofed, but keep going anyway */
390 		if (wflag != 0)
391 			warnx("discarding previous wait interval, using"
392 			      " %g instead", waittime / 1000.0);
393 		wflag++;
394 
395 		if (*++argv) {
396 			count = atoi(*argv);
397 			if (cflag != 0)
398 				warnx("discarding previous count, using %d"
399 				      " instead", count);
400 			cflag++;
401 		} else
402 			count = -1;
403 	}
404 
405 	/*
406 	 * If the user specified a count, but not an interval, we default
407 	 * to an interval of 1 second.
408 	 */
409 	if ((wflag == 0) && (cflag > 0))
410 		waittime = 1 * 1000;
411 
412 	/*
413 	 * If the user specified a wait time, but not a count, we want to
414 	 * go on ad infinitum.  This can be redundant if the user uses the
415 	 * traditional method of specifying the wait, since in that case we
416 	 * already set count = -1 above.  Oh well.
417 	 */
418 	if ((wflag > 0) && (cflag == 0))
419 		count = -1;
420 
421 	bzero(cur.cp_time, sizeof(cur.cp_time));
422 	cur.tk_nout = 0;
423 	cur.tk_nin = 0;
424 
425 	/*
426 	 * Set the snap time to the system boot time (ie: zero), so the
427 	 * stats are calculated since system boot.
428 	 */
429 	cur.snap_time = 0;
430 
431 	/*
432 	 * If the user stops the program (control-Z) and then resumes it,
433 	 * print out the header again.
434 	 */
435 	(void)signal(SIGCONT, needhdr);
436 
437 	/*
438 	 * If our standard output is a tty, then install a SIGWINCH handler
439 	 * and set wresized so that our first iteration through the main
440 	 * iostat loop will peek at the terminal's current rows to find out
441 	 * how many lines can fit in a screenful of output.
442 	 */
443 	if (isatty(fileno(stdout)) != 0) {
444 		wresized = 1;
445 		(void)signal(SIGWINCH, needresize);
446 	} else {
447 		wresized = 0;
448 		wrows = IOSTAT_DEFAULT_ROWS;
449 	}
450 
451 	/*
452 	 * Register a SIGINT handler so that we can print out final statistics
453 	 * when we get that signal
454 	 */
455 	(void)signal(SIGINT, needreturn);
456 
457 	/*
458 	 * Register a SIGALRM handler to implement sleeps if the user uses the
459 	 * -c or -w options
460 	 */
461 	(void)signal(SIGALRM, alarm_clock);
462 	alarmspec.it_interval.tv_sec = waittime / 1000;
463 	alarmspec.it_interval.tv_usec = 1000 * (waittime % 1000);
464 	alarmspec.it_value.tv_sec = waittime / 1000;
465 	alarmspec.it_value.tv_usec = 1000 * (waittime % 1000);
466 	setitimer(ITIMER_REAL, &alarmspec, NULL);
467 
468 	for (headercount = 1;;) {
469 		struct devinfo *tmp_dinfo;
470 		long tmp;
471 		long double etime;
472 		sigset_t sigmask, oldsigmask;
473 
474 		if (Tflag > 0) {
475 			if ((readvar(kd, "kern.tty_nin", X_TTY_NIN, &cur.tk_nin,
476 			     sizeof(cur.tk_nin)) != 0)
477 			 || (readvar(kd, "kern.tty_nout", X_TTY_NOUT,
478 			     &cur.tk_nout, sizeof(cur.tk_nout))!= 0)) {
479 				Tflag = 0;
480 				warnx("disabling TTY statistics");
481 			}
482 		 }
483 
484 		if (Cflag > 0) {
485 			if (kd == NULL) {
486 				if (readvar(kd, "kern.cp_time", 0,
487 				    &cur.cp_time, sizeof(cur.cp_time)) != 0)
488 					Cflag = 0;
489 			} else {
490 				if (kvm_getcptime(kd, cur.cp_time) < 0) {
491 					warnx("kvm_getcptime: %s",
492 					    kvm_geterr(kd));
493 					Cflag = 0;
494 				}
495 			}
496 			if (Cflag == 0)
497 				warnx("disabling CPU time statistics");
498 		}
499 
500 		if (!--headercount) {
501 			phdr();
502 			if (wresized != 0)
503 				doresize();
504 			headercount = wrows;
505 		}
506 
507 		tmp_dinfo = last.dinfo;
508 		last.dinfo = cur.dinfo;
509 		cur.dinfo = tmp_dinfo;
510 
511 		last.snap_time = cur.snap_time;
512 
513 		/*
514 		 * Here what we want to do is refresh our device stats.
515 		 * devstat_getdevs() returns 1 when the device list has changed.
516 		 * If the device list has changed, we want to go through
517 		 * the selection process again, in case a device that we
518 		 * were previously displaying has gone away.
519 		 */
520 		switch (devstat_getdevs(kd, &cur)) {
521 		case -1:
522 			errx(1, "%s", devstat_errbuf);
523 			break;
524 		case 1: {
525 			int retval;
526 
527 			num_devices = cur.dinfo->numdevs;
528 			generation = cur.dinfo->generation;
529 			retval = devstat_selectdevs(&dev_select, &num_selected,
530 						    &num_selections,
531 						    &select_generation,
532 						    generation,
533 						    cur.dinfo->devices,
534 						    num_devices, matches,
535 						    num_matches,
536 						    specified_devices,
537 						    num_devices_specified,
538 						    select_mode, maxshowdevs,
539 						    hflag);
540 			switch(retval) {
541 			case -1:
542 				errx(1, "%s", devstat_errbuf);
543 				break;
544 			case 1:
545 				phdr();
546 				if (wresized != 0)
547 					doresize();
548 				headercount = wrows;
549 				break;
550 			default:
551 				break;
552 			}
553 			break;
554 		}
555 		default:
556 			break;
557 		}
558 
559 		/*
560 		 * We only want to re-select devices if we're in 'top'
561 		 * mode.  This is the only mode where the devices selected
562 		 * could actually change.
563 		 */
564 		if (hflag > 0) {
565 			int retval;
566 			retval = devstat_selectdevs(&dev_select, &num_selected,
567 						    &num_selections,
568 						    &select_generation,
569 						    generation,
570 						    cur.dinfo->devices,
571 						    num_devices, matches,
572 						    num_matches,
573 						    specified_devices,
574 						    num_devices_specified,
575 						    select_mode, maxshowdevs,
576 						    hflag);
577 			switch(retval) {
578 			case -1:
579 				errx(1,"%s", devstat_errbuf);
580 				break;
581 			case 1:
582 				phdr();
583 				if (wresized != 0)
584 					doresize();
585 				headercount = wrows;
586 				break;
587 			default:
588 				break;
589 			}
590 		}
591 
592 		if (Tflag > 0) {
593 			tmp = cur.tk_nin;
594 			cur.tk_nin -= last.tk_nin;
595 			last.tk_nin = tmp;
596 			tmp = cur.tk_nout;
597 			cur.tk_nout -= last.tk_nout;
598 			last.tk_nout = tmp;
599 		}
600 
601 		etime = cur.snap_time - last.snap_time;
602 
603 		if (etime == 0.0)
604 			etime = 1.0;
605 
606 		for (i = 0; i < CPUSTATES; i++) {
607 			tmp = cur.cp_time[i];
608 			cur.cp_time[i] -= last.cp_time[i];
609 			last.cp_time[i] = tmp;
610 		}
611 
612 		if (xflag == 0 && Tflag > 0)
613 			printf("%4.0Lf %5.0Lf", cur.tk_nin / etime,
614 			    cur.tk_nout / etime);
615 
616 		devstats(hflag, etime, havelast);
617 
618 		if (xflag == 0) {
619 			if (Cflag > 0)
620 				cpustats();
621 
622 			printf("\n");
623 		}
624 		fflush(stdout);
625 
626 		if ((count >= 0 && --count <= 0) || return_requested)
627 			break;
628 
629 		/*
630 		 * Use sigsuspend to safely sleep until either signal is
631 		 * received
632 		 */
633 		alarm_rang = 0;
634 		sigemptyset(&sigmask);
635 		sigaddset(&sigmask, SIGINT);
636 		sigaddset(&sigmask, SIGALRM);
637 		sigprocmask(SIG_BLOCK, &sigmask, &oldsigmask);
638 		while (! (alarm_rang || return_requested) ) {
639 			sigsuspend(&oldsigmask);
640 		}
641 		sigprocmask(SIG_UNBLOCK, &sigmask, NULL);
642 
643 		havelast = 1;
644 	}
645 
646 	exit(0);
647 }
648 
649 /*
650  * Force a header to be prepended to the next output.
651  */
652 void
653 needhdr(int signo)
654 {
655 
656 	headercount = 1;
657 }
658 
659 /*
660  * When the terminal is resized, force an update of the maximum number of rows
661  * printed between each header repetition.  Then force a new header to be
662  * prepended to the next output.
663  */
664 void
665 needresize(int signo)
666 {
667 
668 	wresized = 1;
669 	headercount = 1;
670 }
671 
672 /*
673  * Record the alarm so the main loop can break its sleep
674  */
675 void
676 alarm_clock(int signo)
677 {
678 	alarm_rang = 1;
679 }
680 
681 /*
682  * Request that the main loop exit soon
683  */
684 void
685 needreturn(int signo)
686 {
687 	return_requested = 1;
688 }
689 
690 /*
691  * Update the global `wrows' count of terminal rows.
692  */
693 void
694 doresize(void)
695 {
696 	int status;
697 	struct winsize w;
698 
699 	for (;;) {
700 		status = ioctl(fileno(stdout), TIOCGWINSZ, &w);
701 		if (status == -1 && errno == EINTR)
702 			continue;
703 		else if (status == -1)
704 			err(1, "ioctl");
705 		if (w.ws_row > 3)
706 			wrows = w.ws_row - 3;
707 		else
708 			wrows = IOSTAT_DEFAULT_ROWS;
709 		break;
710 	}
711 
712 	/*
713 	 * Inhibit doresize() calls until we are rescheduled by SIGWINCH.
714 	 */
715 	wresized = 0;
716 }
717 
718 static void
719 phdr(void)
720 {
721 	int i, printed;
722 	char devbuf[256];
723 
724 	/*
725 	 * If xflag is set, we need a per-loop header, not a page header, so
726 	 * just return.  We'll print the header in devstats().
727 	 */
728 	if (xflag > 0)
729 		return;
730 
731 	if (Tflag > 0)
732 		(void)printf("       tty");
733 	for (i = 0, printed=0;(i < num_devices) && (printed < maxshowdevs);i++){
734 		int di;
735 		if ((dev_select[i].selected != 0)
736 		 && (dev_select[i].selected <= maxshowdevs)) {
737 			di = dev_select[i].position;
738 			snprintf(devbuf, sizeof(devbuf), "%s%d",
739 					    cur.dinfo->devices[di].device_name,
740 					    cur.dinfo->devices[di].unit_number);
741 			if (oflag > 0)
742 				(void)printf("%13.6s ", devbuf);
743 			else
744 				printf("%16.6s ", devbuf);
745 			printed++;
746 		}
747 	}
748 	if (Cflag > 0)
749 		(void)printf("            cpu\n");
750 	else
751 		(void)printf("\n");
752 
753 	if (Tflag > 0)
754 		(void)printf(" tin  tout");
755 
756 	for (i=0, printed = 0;(i < num_devices) && (printed < maxshowdevs);i++){
757 		if ((dev_select[i].selected != 0)
758 		 && (dev_select[i].selected <= maxshowdevs)) {
759 			if (oflag > 0) {
760 				if (Iflag == 0)
761 					(void)printf(" sps tps msps ");
762 				else
763 					(void)printf(" blk xfr msps ");
764 			} else {
765 				if (Iflag == 0)
766 					printf("  KB/t tps  MB/s ");
767 				else
768 					printf("  KB/t xfrs   MB ");
769 			}
770 			printed++;
771 		}
772 	}
773 	if (Cflag > 0)
774 		(void)printf(" us ni sy in id\n");
775 	else
776 		printf("\n");
777 
778 }
779 
780 static void
781 devstats(int perf_select, long double etime, int havelast)
782 {
783 	int dn;
784 	long double transfers_per_second, transfers_per_second_read;
785 	long double transfers_per_second_write;
786 	long double kb_per_transfer, mb_per_second, mb_per_second_read;
787 	long double mb_per_second_write;
788 	u_int64_t total_bytes, total_transfers, total_blocks;
789 	u_int64_t total_bytes_read, total_transfers_read;
790 	u_int64_t total_bytes_write, total_transfers_write;
791 	long double busy_pct, busy_time;
792 	u_int64_t queue_len;
793 	long double total_mb, blocks_per_second, total_duration;
794 	long double ms_per_other, ms_per_read, ms_per_write, ms_per_transaction;
795 	int firstline = 1;
796 	char *devname;
797 
798 	if (xflag > 0) {
799 		printf("                        extended device statistics  ");
800 		if (Tflag > 0)
801 			printf("      tty ");
802 		if (Cflag > 0)
803 			printf("           cpu ");
804 		printf("\n");
805 		if (Iflag == 0) {
806 			printf("device     r/s   w/s     kr/s     kw/s "
807 			    " ms/r  ms/w  ms/o  ms/t qlen  %%b  ");
808 		} else {
809 			printf("device           r/i         w/i         kr/i"
810 			    "         kw/i qlen   tsvc_t/i      sb/i  ");
811 		}
812 		if (Tflag > 0)
813 			printf("tin  tout ");
814 		if (Cflag > 0)
815 			printf("us ni sy in id ");
816 		printf("\n");
817 	}
818 
819 	for (dn = 0; dn < num_devices; dn++) {
820 		int di;
821 
822 		if (((perf_select == 0) && (dev_select[dn].selected == 0))
823 		 || (dev_select[dn].selected > maxshowdevs))
824 			continue;
825 
826 		di = dev_select[dn].position;
827 
828 		if (devstat_compute_statistics(&cur.dinfo->devices[di],
829 		    havelast ? &last.dinfo->devices[di] : NULL, etime,
830 		    DSM_TOTAL_BYTES, &total_bytes,
831 		    DSM_TOTAL_BYTES_READ, &total_bytes_read,
832 		    DSM_TOTAL_BYTES_WRITE, &total_bytes_write,
833 		    DSM_TOTAL_TRANSFERS, &total_transfers,
834 		    DSM_TOTAL_TRANSFERS_READ, &total_transfers_read,
835 		    DSM_TOTAL_TRANSFERS_WRITE, &total_transfers_write,
836 		    DSM_TOTAL_BLOCKS, &total_blocks,
837 		    DSM_KB_PER_TRANSFER, &kb_per_transfer,
838 		    DSM_TRANSFERS_PER_SECOND, &transfers_per_second,
839 		    DSM_TRANSFERS_PER_SECOND_READ, &transfers_per_second_read,
840 		    DSM_TRANSFERS_PER_SECOND_WRITE, &transfers_per_second_write,
841 		    DSM_MB_PER_SECOND, &mb_per_second,
842 		    DSM_MB_PER_SECOND_READ, &mb_per_second_read,
843 		    DSM_MB_PER_SECOND_WRITE, &mb_per_second_write,
844 		    DSM_BLOCKS_PER_SECOND, &blocks_per_second,
845 		    DSM_MS_PER_TRANSACTION, &ms_per_transaction,
846 		    DSM_MS_PER_TRANSACTION_READ, &ms_per_read,
847 		    DSM_MS_PER_TRANSACTION_WRITE, &ms_per_write,
848 		    DSM_MS_PER_TRANSACTION_OTHER, &ms_per_other,
849 		    DSM_BUSY_PCT, &busy_pct,
850 		    DSM_QUEUE_LENGTH, &queue_len,
851 		    DSM_TOTAL_DURATION, &total_duration,
852 		    DSM_TOTAL_BUSY_TIME, &busy_time,
853 		    DSM_NONE) != 0)
854 			errx(1, "%s", devstat_errbuf);
855 
856 		if (perf_select != 0) {
857 			dev_select[dn].bytes = total_bytes;
858 			if ((dev_select[dn].selected == 0)
859 			 || (dev_select[dn].selected > maxshowdevs))
860 				continue;
861 		}
862 
863 		if (Kflag > 0 || xflag > 0) {
864 			int block_size = cur.dinfo->devices[di].block_size;
865 			total_blocks = total_blocks * (block_size ?
866 						       block_size : 512) / 1024;
867 		}
868 
869 		if (xflag > 0) {
870 			if (asprintf(&devname, "%s%d",
871 			    cur.dinfo->devices[di].device_name,
872 			    cur.dinfo->devices[di].unit_number) == -1)
873 				err(1, "asprintf");
874 			/*
875 			 * If zflag is set, skip any devices with zero I/O.
876 			 */
877 			if (zflag == 0 || transfers_per_second_read > 0.05 ||
878 			    transfers_per_second_write > 0.05 ||
879 			    mb_per_second_read > ((long double).0005)/1024 ||
880 			    mb_per_second_write > ((long double).0005)/1024 ||
881 			    busy_pct > 0.5) {
882 				if (Iflag == 0)
883 					printf("%-8.8s %5d %5d %8.1Lf "
884 					    "%8.1Lf %5d %5d %5d %5d "
885 					    "%4" PRIu64 " %3.0Lf ",
886 					    devname,
887 					    (int)transfers_per_second_read,
888 					    (int)transfers_per_second_write,
889 					    mb_per_second_read * 1024,
890 					    mb_per_second_write * 1024,
891 					    (int)ms_per_read, (int)ms_per_write,
892 					    (int)ms_per_other,
893 					    (int)ms_per_transaction,
894 					    queue_len, busy_pct);
895 				else
896 					printf("%-8.8s %11.1Lf %11.1Lf "
897 					    "%12.1Lf %12.1Lf %4" PRIu64
898 					    " %10.1Lf %9.1Lf ",
899 					    devname,
900 					    (long double)total_transfers_read,
901 					    (long double)total_transfers_write,
902 					    (long double)
903 					        total_bytes_read / 1024,
904 					    (long double)
905 					        total_bytes_write / 1024,
906 					    queue_len,
907 					    total_duration, busy_time);
908 				if (firstline) {
909 					/*
910 					 * If this is the first device
911 					 * we're printing, also print
912 					 * CPU or TTY stats if requested.
913 					 */
914 					firstline = 0;
915 					if (Tflag > 0)
916 						printf("%4.0Lf%5.0Lf",
917 						    cur.tk_nin / etime,
918 						    cur.tk_nout / etime);
919 					if (Cflag > 0)
920 						cpustats();
921 				}
922 				printf("\n");
923 			}
924 			free(devname);
925 		} else if (oflag > 0) {
926 			int msdig = (ms_per_transaction < 100.0) ? 1 : 0;
927 
928 			if (Iflag == 0)
929 				printf("%4.0Lf%4.0Lf%5.*Lf ",
930 				       blocks_per_second,
931 				       transfers_per_second,
932 				       msdig,
933 				       ms_per_transaction);
934 			else
935 				printf("%4.1" PRIu64 "%4.1" PRIu64 "%5.*Lf ",
936 				       total_blocks,
937 				       total_transfers,
938 				       msdig,
939 				       ms_per_transaction);
940 		} else {
941 			if (Iflag == 0)
942 				printf(" %5.2Lf %3.0Lf %5.2Lf ",
943 				       kb_per_transfer,
944 				       transfers_per_second,
945 				       mb_per_second);
946 			else {
947 				total_mb = total_bytes;
948 				total_mb /= 1024 * 1024;
949 
950 				printf(" %5.2Lf %3.1" PRIu64 " %5.2Lf ",
951 				       kb_per_transfer,
952 				       total_transfers,
953 				       total_mb);
954 			}
955 		}
956 	}
957 	if (xflag > 0 && zflag > 0 && firstline == 1 &&
958 	    (Tflag > 0 || Cflag > 0)) {
959 		/*
960 		 * If zflag is set and we did not print any device
961 		 * lines I/O because they were all zero,
962 		 * print TTY/CPU stats.
963 		 */
964 		printf("%52s","");
965 		if (Tflag > 0)
966 			printf("%4.0Lf %5.0Lf", cur.tk_nin / etime,
967 			    cur.tk_nout / etime);
968 		if (Cflag > 0)
969 			cpustats();
970 		printf("\n");
971 	}
972 }
973 
974 static void
975 cpustats(void)
976 {
977 	int state;
978 	double time;
979 
980 	time = 0.0;
981 
982 	for (state = 0; state < CPUSTATES; ++state)
983 		time += cur.cp_time[state];
984 	for (state = 0; state < CPUSTATES; ++state)
985 		printf(" %2.0f",
986 		       rint(100. * cur.cp_time[state] / (time ? time : 1)));
987 }
988 
989 static int
990 readvar(kvm_t *kd, const char *name, int nlid, void *ptr, size_t len)
991 {
992 	if (kd != NULL) {
993 		ssize_t nbytes;
994 
995 		nbytes = kvm_read(kd, namelist[nlid].n_value, ptr, len);
996 
997 		if (nbytes < 0) {
998 			warnx("kvm_read(%s): %s", namelist[nlid].n_name,
999 			    kvm_geterr(kd));
1000 			return (1);
1001 		}
1002 		if (nbytes != len) {
1003 			warnx("kvm_read(%s): expected %zu bytes, got %zd bytes",
1004 			      namelist[nlid].n_name, len, nbytes);
1005 			return (1);
1006 		}
1007 	} else {
1008 		size_t nlen = len;
1009 
1010 		if (sysctlbyname(name, ptr, &nlen, NULL, 0) == -1) {
1011 			warn("sysctl(%s...) failed", name);
1012 			return (1);
1013 		}
1014 		if (nlen != len) {
1015 			warnx("sysctl(%s...): expected %lu, got %lu", name,
1016 			      (unsigned long)len, (unsigned long)nlen);
1017 			return (1);
1018 		}
1019 	}
1020 	return (0);
1021 }
1022