usr.sbin/iostat/iostat.c

   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_TK_NIN        0
 122         { "_tk_nin" },
 123 #define X_TK_NOUT       1
 124         { "_tk_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_TK_NIN, &cur.tk_nin,
 476                              sizeof(cur.tk_nin)) != 0)
 477                          || (readvar(kd, "kern.tty_nout", X_TK_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, transfers_per_second_write;
 785         long double kb_per_transfer, mb_per_second, mb_per_second_read, mb_per_second_write;
 786         u_int64_t total_bytes, total_transfers, total_blocks;
 787         u_int64_t total_bytes_read, total_transfers_read;
 788         u_int64_t total_bytes_write, total_transfers_write;
 789         long double busy_pct, busy_time;
 790         u_int64_t queue_len;
 791         long double total_mb;
 792         long double blocks_per_second, ms_per_transaction, total_duration;
 793         int firstline = 1;
 794         char *devname;
 795
 796         if (xflag > 0) {
 797                 printf("                        extended device statistics  ");
 798                 if (Tflag > 0)
 799                         printf("      tty ");
 800                 if (Cflag > 0)
 801                         printf("           cpu ");
 802                 printf("\n");
 803                 if (Iflag == 0) {
 804                         printf("device     r/s   w/s    kr/s    kw/s qlen "
 805                             "svc_t  %%b  ");
 806                 } else {
 807                         printf("device           r/i         w/i         kr/i"
 808                             "         kw/i qlen   tsvc_t/i      sb/i  ");
 809                 }
 810                 if (Tflag > 0)
 811                         printf("tin  tout ");
 812                 if (Cflag > 0)
 813                         printf("us ni sy in id ");
 814                 printf("\n");
 815         }
 816
 817         for (dn = 0; dn < num_devices; dn++) {
 818                 int di;
 819
 820                 if (((perf_select == 0) && (dev_select[dn].selected == 0))
 821                  || (dev_select[dn].selected > maxshowdevs))
 822                         continue;
 823
 824                 di = dev_select[dn].position;
 825
 826                 if (devstat_compute_statistics(&cur.dinfo->devices[di],
 827                     havelast ? &last.dinfo->devices[di] : NULL, etime,
 828                     DSM_TOTAL_BYTES, &total_bytes,
 829                     DSM_TOTAL_BYTES_READ, &total_bytes_read,
 830                     DSM_TOTAL_BYTES_WRITE, &total_bytes_write,
 831                     DSM_TOTAL_TRANSFERS, &total_transfers,
 832                     DSM_TOTAL_TRANSFERS_READ, &total_transfers_read,
 833                     DSM_TOTAL_TRANSFERS_WRITE, &total_transfers_write,
 834                     DSM_TOTAL_BLOCKS, &total_blocks,
 835                     DSM_KB_PER_TRANSFER, &kb_per_transfer,
 836                     DSM_TRANSFERS_PER_SECOND, &transfers_per_second,
 837                     DSM_TRANSFERS_PER_SECOND_READ, &transfers_per_second_read,
 838                     DSM_TRANSFERS_PER_SECOND_WRITE, &transfers_per_second_write,
 839                     DSM_MB_PER_SECOND, &mb_per_second,
 840                     DSM_MB_PER_SECOND_READ, &mb_per_second_read,
 841                     DSM_MB_PER_SECOND_WRITE, &mb_per_second_write,
 842                     DSM_BLOCKS_PER_SECOND, &blocks_per_second,
 843                     DSM_MS_PER_TRANSACTION, &ms_per_transaction,
 844                     DSM_BUSY_PCT, &busy_pct,
 845                     DSM_QUEUE_LENGTH, &queue_len,
 846                     DSM_TOTAL_DURATION, &total_duration,
 847                     DSM_TOTAL_BUSY_TIME, &busy_time,
 848                     DSM_NONE) != 0)
 849                         errx(1, "%s", devstat_errbuf);
 850
 851                 if (perf_select != 0) {
 852                         dev_select[dn].bytes = total_bytes;
 853                         if ((dev_select[dn].selected == 0)
 854                          || (dev_select[dn].selected > maxshowdevs))
 855                                 continue;
 856                 }
 857
 858                 if (Kflag > 0 || xflag > 0) {
 859                         int block_size = cur.dinfo->devices[di].block_size;
 860                         total_blocks = total_blocks * (block_size ?
 861                                                        block_size : 512) / 1024;
 862                 }
 863
 864                 if (xflag > 0) {
 865                         if (asprintf(&devname, "%s%d",
 866                             cur.dinfo->devices[di].device_name,
 867                             cur.dinfo->devices[di].unit_number) == -1)
 868                                 err(1, "asprintf");
 869                         /*
 870                          * If zflag is set, skip any devices with zero I/O.
 871                          */
 872                         if (zflag == 0 || transfers_per_second_read > 0.05 ||
 873                             transfers_per_second_write > 0.05 ||
 874                             mb_per_second_read > ((long double).0005)/1024 ||
 875                             mb_per_second_write > ((long double).0005)/1024 ||
 876                             busy_pct > 0.5) {
 877                                 if (Iflag == 0)
 878                                         printf("%-8.8s %5.1Lf %5.1Lf %7.1Lf %7.1Lf %4" PRIu64 " %5.1Lf %3.0Lf ",
 879                                             devname, transfers_per_second_read,
 880                                             transfers_per_second_write,
 881                                             mb_per_second_read * 1024,
 882                                             mb_per_second_write * 1024,
 883                                             queue_len,
 884                                             ms_per_transaction, busy_pct);
 885                                 else
 886                                         printf("%-8.8s %11.1Lf %11.1Lf "
 887                                             "%12.1Lf %12.1Lf %4" PRIu64
 888                                             " %10.1Lf %9.1Lf ",
 889                                             devname,
 890                                             (long double)total_transfers_read,
 891                                             (long double)total_transfers_write,
 892                                             (long double)
 893                                                 total_bytes_read / 1024,
 894                                             (long double)
 895                                                 total_bytes_write / 1024,
 896                                             queue_len,
 897                                             total_duration, busy_time);
 898                                 if (firstline) {
 899                                         /*
 900                                          * If this is the first device
 901                                          * we're printing, also print
 902                                          * CPU or TTY stats if requested.
 903                                          */
 904                                         firstline = 0;
 905                                         if (Tflag > 0)
 906                                                 printf("%4.0Lf%5.0Lf",
 907                                                     cur.tk_nin / etime,
 908                                                     cur.tk_nout / etime);
 909                                         if (Cflag > 0)
 910                                                 cpustats();
 911                                 }
 912                                 printf("\n");
 913                         }
 914                         free(devname);
 915                 } else if (oflag > 0) {
 916                         int msdig = (ms_per_transaction < 100.0) ? 1 : 0;
 917
 918                         if (Iflag == 0)
 919                                 printf("%4.0Lf%4.0Lf%5.*Lf ",
 920                                        blocks_per_second,
 921                                        transfers_per_second,
 922                                        msdig,
 923                                        ms_per_transaction);
 924                         else
 925                                 printf("%4.1" PRIu64 "%4.1" PRIu64 "%5.*Lf ",
 926                                        total_blocks,
 927                                        total_transfers,
 928                                        msdig,
 929                                        ms_per_transaction);
 930                 } else {
 931                         if (Iflag == 0)
 932                                 printf(" %5.2Lf %3.0Lf %5.2Lf ",
 933                                        kb_per_transfer,
 934                                        transfers_per_second,
 935                                        mb_per_second);
 936                         else {
 937                                 total_mb = total_bytes;
 938                                 total_mb /= 1024 * 1024;
 939
 940                                 printf(" %5.2Lf %3.1" PRIu64 " %5.2Lf ",
 941                                        kb_per_transfer,
 942                                        total_transfers,
 943                                        total_mb);
 944                         }
 945                 }
 946         }
 947         if (xflag > 0 && zflag > 0 && firstline == 1 &&
 948             (Tflag > 0 || Cflag > 0)) {
 949                 /*
 950                  * If zflag is set and we did not print any device
 951                  * lines I/O because they were all zero,
 952                  * print TTY/CPU stats.
 953                  */
 954                 printf("%52s","");
 955                 if (Tflag > 0)
 956                         printf("%4.0Lf %5.0Lf", cur.tk_nin / etime,
 957                             cur.tk_nout / etime);
 958                 if (Cflag > 0)
 959                         cpustats();
 960                 printf("\n");
 961         }
 962 }
 963
 964 static void
 965 cpustats(void)
 966 {
 967         int state;
 968         double time;
 969
 970         time = 0.0;
 971
 972         for (state = 0; state < CPUSTATES; ++state)
 973                 time += cur.cp_time[state];
 974         for (state = 0; state < CPUSTATES; ++state)
 975                 printf(" %2.0f",
 976                        rint(100. * cur.cp_time[state] / (time ? time : 1)));
 977 }
 978
 979 static int
 980 readvar(kvm_t *kd, const char *name, int nlid, void *ptr, size_t len)
 981 {
 982         if (kd != NULL) {
 983                 ssize_t nbytes;
 984
 985                 nbytes = kvm_read(kd, namelist[nlid].n_value, ptr, len);
 986
 987                 if (nbytes < 0) {
 988                         warnx("kvm_read(%s): %s", namelist[nlid].n_name,
 989                             kvm_geterr(kd));
 990                         return (1);
 991                 }
 992                 if (nbytes != len) {
 993                         warnx("kvm_read(%s): expected %zu bytes, got %zd bytes",
 994                               namelist[nlid].n_name, len, nbytes);
 995                         return (1);
 996                 }
 997         } else {
 998                 size_t nlen = len;
 999
1000                 if (sysctlbyname(name, ptr, &nlen, NULL, 0) == -1) {
1001                         warn("sysctl(%s...) failed", name);
1002                         return (1);
1003                 }
1004                 if (nlen != len) {
1005                         warnx("sysctl(%s...): expected %lu, got %lu", name,
1006                               (unsigned long)len, (unsigned long)nlen);
1007                         return (1);
1008                 }
1009         }
1010         return (0);
1011 }