lib/getloadavg.c

   1 /* Get the system load averages.
   2    Copyright (C) 1985, 86, 87, 88, 89, 91, 92, 93, 1994, 1995
   3         Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2, or (at your option)
   8    any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software
  17    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  18    USA.  */
  19
  20 /* Compile-time symbols that this file uses:
  21
  22    FIXUP_KERNEL_SYMBOL_ADDR()   Adjust address in returned struct nlist.
  23    KERNEL_FILE                  Pathname of the kernel to nlist.
  24    LDAV_CVT()                   Scale the load average from the kernel.
  25                                 Returns a double.
  26    LDAV_SYMBOL                  Name of kernel symbol giving load average.
  27    LOAD_AVE_TYPE                Type of the load average array in the kernel.
  28                                 Must be defined unless one of
  29                                 apollo, DGUX, NeXT, or UMAX is defined;
  30                                 otherwise, no load average is available.
  31    NLIST_STRUCT                 Include nlist.h, not a.out.h, and
  32                                 the nlist n_name element is a pointer,
  33                                 not an array.
  34    NLIST_NAME_UNION             struct nlist has an n_un member, not n_name.
  35    LINUX_LDAV_FILE              [__linux__]: File containing load averages.
  36
  37    Specific system predefines this file uses, aside from setting
  38    default values if not emacs:
  39
  40    apollo
  41    BSD                          Real BSD, not just BSD-like.
  42    convex
  43    DGUX
  44    eunice                       UNIX emulator under VMS.
  45    hpux
  46    MSDOS                        No-op for MSDOS.
  47    NeXT
  48    sgi
  49    sequent                      Sequent Dynix 3.x.x (BSD)
  50    _SEQUENT_                    Sequent DYNIX/ptx 1.x.x (SYSV)
  51    sony_news                    NEWS-OS (works at least for 4.1C)
  52    UMAX
  53    UMAX4_3
  54    VMS
  55    WIN32                        No-op for Windows95/NT.
  56    __linux__                    Linux: assumes /proc filesystem mounted.
  57                                 Support from Michael K. Johnson.
  58    __NetBSD__                   NetBSD: assumes /kern filesystem mounted.
  59
  60    In addition, to avoid nesting many #ifdefs, we internally set
  61    LDAV_DONE to indicate that the load average has been computed.
  62
  63    We also #define LDAV_PRIVILEGED if a program will require
  64    special installation to be able to call getloadavg.  */
  65
  66 /* This should always be first.  */
  67 #ifdef HAVE_CONFIG_H
  68 #include <config.h>
  69 #endif
  70
  71 #include <sys/types.h>
  72
  73 /* Both the Emacs and non-Emacs sections want this.  Some
  74    configuration files' definitions for the LOAD_AVE_CVT macro (like
  75    sparc.h's) use macros like FSCALE, defined here.  */
  76 #ifdef unix
  77 #include <sys/param.h>
  78 #endif
  79
  80
  81 /* Exclude all the code except the test program at the end
  82    if the system has its own `getloadavg' function.
  83
  84    The declaration of `errno' is needed by the test program
  85    as well as the function itself, so it comes first.  */
  86
  87 #include <errno.h>
  88
  89 #ifndef errno
  90 extern int errno;
  91 #endif
  92
  93 #ifndef HAVE_GETLOADAVG
  94
  95
  96 /* The existing Emacs configuration files define a macro called
  97    LOAD_AVE_CVT, which accepts a value of type LOAD_AVE_TYPE, and
  98    returns the load average multiplied by 100.  What we actually want
  99    is a macro called LDAV_CVT, which returns the load average as an
 100    unmultiplied double.
 101
 102    For backwards compatibility, we'll define LDAV_CVT in terms of
 103    LOAD_AVE_CVT, but future machine config files should just define
 104    LDAV_CVT directly.  */
 105
 106 #if !defined(LDAV_CVT) && defined(LOAD_AVE_CVT)
 107 #define LDAV_CVT(n) (LOAD_AVE_CVT (n) / 100.0)
 108 #endif
 109
 110 #if !defined (BSD) && defined (ultrix)
 111 /* Ultrix behaves like BSD on Vaxen.  */
 112 #define BSD
 113 #endif
 114
 115 #ifdef NeXT
 116 /* NeXT in the 2.{0,1,2} releases defines BSD in <sys/param.h>, which
 117    conflicts with the definition understood in this file, that this
 118    really is BSD. */
 119 #undef BSD
 120
 121 /* NeXT defines FSCALE in <sys/param.h>.  However, we take FSCALE being
 122    defined to mean that the nlist method should be used, which is not true.  */
 123 #undef FSCALE
 124 #endif
 125
 126 /* Set values that are different from the defaults, which are
 127    set a little farther down with #ifndef.  */
 128
 129
 130 /* Some shorthands.  */
 131
 132 #if defined (HPUX) && !defined (hpux)
 133 #define hpux
 134 #endif
 135
 136 #if defined (__hpux) && !defined (hpux)
 137 #define hpux
 138 #endif
 139
 140 #if defined (__sun) && !defined (sun)
 141 #define sun
 142 #endif
 143
 144 #if defined(hp300) && !defined(hpux)
 145 #define MORE_BSD
 146 #endif
 147
 148 #if defined(ultrix) && defined(mips)
 149 #define decstation
 150 #endif
 151
 152 #if defined (__SVR4) && !defined (SVR4)
 153 #define SVR4
 154 #endif
 155
 156 #if (defined(sun) && defined(SVR4)) || defined (SOLARIS2)
 157 #define SUNOS_5
 158 #endif
 159
 160 #if defined (__osf__) && (defined (__alpha) || defined (__alpha__))
 161 #define OSF_ALPHA
 162 #include <sys/table.h>
 163 #endif
 164
 165 #if defined (__osf__) && (defined (mips) || defined (__mips__))
 166 #define OSF_MIPS
 167 #include <sys/table.h>
 168 #endif
 169
 170 /* UTek's /bin/cc on the 4300 has no architecture specific cpp define by
 171    default, but _MACH_IND_SYS_TYPES is defined in <sys/types.h>.  Combine
 172    that with a couple of other things and we'll have a unique match.  */
 173 #if !defined (tek4300) && defined (unix) && defined (m68k) && defined (mc68000) && defined (mc68020) && defined (_MACH_IND_SYS_TYPES)
 174 #define tek4300                 /* Define by emacs, but not by other users.  */
 175 #endif
 176
 177
 178 /* VAX C can't handle multi-line #ifs, or lines longer than 256 chars.  */
 179 #ifndef LOAD_AVE_TYPE
 180
 181 #ifdef MORE_BSD
 182 #define LOAD_AVE_TYPE long
 183 #endif
 184
 185 #ifdef sun
 186 #define LOAD_AVE_TYPE long
 187 #endif
 188
 189 #ifdef decstation
 190 #define LOAD_AVE_TYPE long
 191 #endif
 192
 193 #ifdef _SEQUENT_
 194 #define LOAD_AVE_TYPE long
 195 #endif
 196
 197 #ifdef sgi
 198 #define LOAD_AVE_TYPE long
 199 #endif
 200
 201 #ifdef SVR4
 202 #define LOAD_AVE_TYPE long
 203 #endif
 204
 205 #ifdef sony_news
 206 #define LOAD_AVE_TYPE long
 207 #endif
 208
 209 #ifdef sequent
 210 #define LOAD_AVE_TYPE long
 211 #endif
 212
 213 #ifdef OSF_ALPHA
 214 #define LOAD_AVE_TYPE long
 215 #endif
 216
 217 #if defined (ardent) && defined (titan)
 218 #define LOAD_AVE_TYPE long
 219 #endif
 220
 221 #ifdef tek4300
 222 #define LOAD_AVE_TYPE long
 223 #endif
 224
 225 #if defined(alliant) && defined(i860) /* Alliant FX/2800 */
 226 #define LOAD_AVE_TYPE long
 227 #endif
 228
 229 #ifdef _AIX
 230 #define LOAD_AVE_TYPE long
 231 #endif
 232
 233 #ifdef convex
 234 #define LOAD_AVE_TYPE double
 235 #ifndef LDAV_CVT
 236 #define LDAV_CVT(n) (n)
 237 #endif
 238 #endif
 239
 240 #endif /* No LOAD_AVE_TYPE.  */
 241
 242 #ifdef OSF_ALPHA
 243 /* <sys/param.h> defines an incorrect value for FSCALE on Alpha OSF/1,
 244    according to ghazi@noc.rutgers.edu.  */
 245 #undef FSCALE
 246 #define FSCALE 1024.0
 247 #endif
 248
 249 #if defined(alliant) && defined(i860) /* Alliant FX/2800 */
 250 /* <sys/param.h> defines an incorrect value for FSCALE on an
 251    Alliant FX/2800 Concentrix 2.2, according to ghazi@noc.rutgers.edu.  */
 252 #undef FSCALE
 253 #define FSCALE 100.0
 254 #endif
 255
 256
 257 #ifndef FSCALE
 258
 259 /* SunOS and some others define FSCALE in sys/param.h.  */
 260
 261 #ifdef MORE_BSD
 262 #define FSCALE 2048.0
 263 #endif
 264
 265 #if defined(MIPS) || defined(SVR4) || defined(decstation)
 266 #define FSCALE 256
 267 #endif
 268
 269 #if defined (sgi) || defined (sequent)
 270 /* Sometimes both MIPS and sgi are defined, so FSCALE was just defined
 271    above under #ifdef MIPS.  But we want the sgi value.  */
 272 #undef FSCALE
 273 #define FSCALE 1000.0
 274 #endif
 275
 276 #if defined (ardent) && defined (titan)
 277 #define FSCALE 65536.0
 278 #endif
 279
 280 #ifdef tek4300
 281 #define FSCALE 100.0
 282 #endif
 283
 284 #ifdef _AIX
 285 #define FSCALE 65536.0
 286 #endif
 287
 288 #endif  /* Not FSCALE.  */
 289
 290 #if !defined (LDAV_CVT) && defined (FSCALE)
 291 #define LDAV_CVT(n) (((double) (n)) / FSCALE)
 292 #endif
 293
 294 /* VAX C can't handle multi-line #ifs, or lines longer that 256 characters.  */
 295 #ifndef NLIST_STRUCT
 296
 297 #ifdef MORE_BSD
 298 #define NLIST_STRUCT
 299 #endif
 300
 301 #ifdef sun
 302 #define NLIST_STRUCT
 303 #endif
 304
 305 #ifdef decstation
 306 #define NLIST_STRUCT
 307 #endif
 308
 309 #ifdef hpux
 310 #define NLIST_STRUCT
 311 #endif
 312
 313 #if defined (_SEQUENT_) || defined (sequent)
 314 #define NLIST_STRUCT
 315 #endif
 316
 317 #ifdef sgi
 318 #define NLIST_STRUCT
 319 #endif
 320
 321 #ifdef SVR4
 322 #define NLIST_STRUCT
 323 #endif
 324
 325 #ifdef sony_news
 326 #define NLIST_STRUCT
 327 #endif
 328
 329 #ifdef OSF_ALPHA
 330 #define NLIST_STRUCT
 331 #endif
 332
 333 #if defined (ardent) && defined (titan)
 334 #define NLIST_STRUCT
 335 #endif
 336
 337 #ifdef tek4300
 338 #define NLIST_STRUCT
 339 #endif
 340
 341 #ifdef butterfly
 342 #define NLIST_STRUCT
 343 #endif
 344
 345 #if defined(alliant) && defined(i860) /* Alliant FX/2800 */
 346 #define NLIST_STRUCT
 347 #endif
 348
 349 #ifdef _AIX
 350 #define NLIST_STRUCT
 351 #endif
 352
 353 #endif /* defined (NLIST_STRUCT) */
 354
 355
 356 #if defined(sgi) || (defined(mips) && !defined(BSD))
 357 #define FIXUP_KERNEL_SYMBOL_ADDR(nl) ((nl)[0].n_value &= ~(1 << 31))
 358 #endif
 359
 360
 361 #if !defined (KERNEL_FILE) && defined (sequent)
 362 #define KERNEL_FILE "/dynix"
 363 #endif
 364
 365 #if !defined (KERNEL_FILE) && defined (hpux)
 366 #define KERNEL_FILE "/hp-ux"
 367 #endif
 368
 369 #if !defined(KERNEL_FILE) && (defined(_SEQUENT_) || defined(MIPS) || defined(SVR4) || defined(ISC) || defined (sgi) || (defined (ardent) && defined (titan)))
 370 #define KERNEL_FILE "/unix"
 371 #endif
 372
 373
 374 #if !defined (LDAV_SYMBOL) && defined (alliant)
 375 #define LDAV_SYMBOL "_Loadavg"
 376 #endif
 377
 378 #if !defined(LDAV_SYMBOL) && ((defined(hpux) && !defined(hp9000s300)) || defined(_SEQUENT_) || defined(SVR4) || defined(ISC) || defined(sgi) || (defined (ardent) && defined (titan)) || defined (_AIX))
 379 #define LDAV_SYMBOL "avenrun"
 380 #endif
 381
 382 #ifdef HAVE_UNISTD_H
 383 #include <unistd.h>
 384 #endif
 385
 386 #include <stdio.h>
 387
 388 /* LOAD_AVE_TYPE should only get defined if we're going to use the
 389    nlist method.  */
 390 #if !defined(LOAD_AVE_TYPE) && (defined(BSD) || defined(LDAV_CVT) || defined(KERNEL_FILE) || defined(LDAV_SYMBOL))
 391 #define LOAD_AVE_TYPE double
 392 #endif
 393
 394 #ifdef LOAD_AVE_TYPE
 395
 396 #ifndef VMS
 397 #ifndef __linux__
 398 #ifndef NLIST_STRUCT
 399 #include <a.out.h>
 400 #else /* NLIST_STRUCT */
 401 #include <nlist.h>
 402 #endif /* NLIST_STRUCT */
 403
 404 #ifdef SUNOS_5
 405 #include <fcntl.h>
 406 #include <kvm.h>
 407 #include <kstat.h>
 408 #endif
 409
 410 #ifndef KERNEL_FILE
 411 #define KERNEL_FILE "/vmunix"
 412 #endif /* KERNEL_FILE */
 413
 414 #ifndef LDAV_SYMBOL
 415 #define LDAV_SYMBOL "_avenrun"
 416 #endif /* LDAV_SYMBOL */
 417 #endif /* __linux__ */
 418
 419 #else /* VMS */
 420
 421 #ifndef eunice
 422 #include <iodef.h>
 423 #include <descrip.h>
 424 #else /* eunice */
 425 #include <vms/iodef.h>
 426 #endif /* eunice */
 427 #endif /* VMS */
 428
 429 #ifndef LDAV_CVT
 430 #define LDAV_CVT(n) ((double) (n))
 431 #endif /* !LDAV_CVT */
 432
 433 #endif /* LOAD_AVE_TYPE */
 434
 435 #ifdef NeXT
 436 #ifdef HAVE_MACH_MACH_H
 437 #include <mach/mach.h>
 438 #else
 439 #include <mach.h>
 440 #endif
 441 #endif /* NeXT */
 442
 443 #ifdef sgi
 444 #include <sys/sysmp.h>
 445 #endif /* sgi */
 446
 447 #ifdef UMAX
 448 #include <stdio.h>
 449 #include <signal.h>
 450 #include <sys/time.h>
 451 #include <sys/wait.h>
 452 #include <sys/syscall.h>
 453
 454 #ifdef UMAX_43
 455 #include <machine/cpu.h>
 456 #include <inq_stats/statistics.h>
 457 #include <inq_stats/sysstats.h>
 458 #include <inq_stats/cpustats.h>
 459 #include <inq_stats/procstats.h>
 460 #else /* Not UMAX_43.  */
 461 #include <sys/sysdefs.h>
 462 #include <sys/statistics.h>
 463 #include <sys/sysstats.h>
 464 #include <sys/cpudefs.h>
 465 #include <sys/cpustats.h>
 466 #include <sys/procstats.h>
 467 #endif /* Not UMAX_43.  */
 468 #endif /* UMAX */
 469
 470 #ifdef DGUX
 471 #include <sys/dg_sys_info.h>
 472 #endif
 473
 474 #if defined(HAVE_FCNTL_H) || defined(_POSIX_VERSION)
 475 #include <fcntl.h>
 476 #else
 477 #include <sys/file.h>
 478 #endif
 479 \f
 480 /* Avoid static vars inside a function since in HPUX they dump as pure.  */
 481
 482 #ifdef NeXT
 483 static processor_set_t default_set;
 484 static int getloadavg_initialized;
 485 #endif /* NeXT */
 486
 487 #ifdef UMAX
 488 static unsigned int cpus = 0;
 489 static unsigned int samples;
 490 #endif /* UMAX */
 491
 492 #ifdef DGUX
 493 static struct dg_sys_info_load_info load_info;  /* what-a-mouthful! */
 494 #endif /* DGUX */
 495
 496 #ifdef LOAD_AVE_TYPE
 497 /* File descriptor open to /dev/kmem or VMS load ave driver.  */
 498 static int channel;
 499 /* Nonzero iff channel is valid.  */
 500 static int getloadavg_initialized;
 501 /* Offset in kmem to seek to read load average, or 0 means invalid.  */
 502 static long offset;
 503
 504 #if !defined(VMS) && !defined(sgi) && !defined(__linux__)
 505 static struct nlist nl[2];
 506 #endif /* Not VMS or sgi */
 507
 508 #ifdef SUNOS_5
 509 static kvm_t *kd;
 510 #endif /* SUNOS_5 */
 511
 512 #endif /* LOAD_AVE_TYPE */
 513 \f
 514 /* Put the 1 minute, 5 minute and 15 minute load averages
 515    into the first NELEM elements of LOADAVG.
 516    Return the number written (never more than 3, but may be less than NELEM),
 517    or -1 if an error occurred.  */
 518
 519 int
 520 getloadavg (loadavg, nelem)
 521      double loadavg[];
 522      int nelem;
 523 {
 524   int elem = 0;                 /* Return value.  */
 525
 526 #ifdef NO_GET_LOAD_AVG
 527 #define LDAV_DONE
 528   /* Set errno to zero to indicate that there was no particular error;
 529      this function just can't work at all on this system.  */
 530   errno = 0;
 531   elem = -1;
 532 #endif
 533
 534 #if !defined (LDAV_DONE) && defined (SUNOS_5)
 535 /* Use libkstat because we don't have to be root.  */
 536 #define LDAV_DONE
 537   kstat_ctl_t *kc;
 538   kstat_t *ksp;
 539   kstat_named_t *kn;
 540
 541   kc = kstat_open ();
 542   if (kc == 0) return -1;
 543   ksp = kstat_lookup (kc, "unix", 0, "system_misc");
 544   if (ksp == 0 ) return -1;
 545   if (kstat_read (kc, ksp, 0) == -1) return -1;
 546
 547
 548   kn = kstat_data_lookup (ksp, "avenrun_1min");
 549   if (kn == 0)
 550     {
 551       /* Return -1 if no load average information is available.  */
 552       nelem = 0;
 553       elem = -1;
 554     }
 555
 556   if (nelem >= 1)
 557     loadavg[elem++] = (double) kn->value.ul/FSCALE;
 558
 559   if (nelem >= 2)
 560     {
 561       kn = kstat_data_lookup (ksp, "avenrun_5min");
 562       if (kn != 0)
 563         {
 564           loadavg[elem++] = (double) kn->value.ul/FSCALE;
 565
 566           if (nelem >= 3)
 567             {
 568               kn = kstat_data_lookup (ksp, "avenrun_15min");
 569               if (kn != 0)
 570                 loadavg[elem++] = (double) kn->value.ul/FSCALE;
 571             }
 572         }
 573     }
 574
 575   kstat_close (kc);
 576 #endif /* SUNOS_5 */
 577
 578 #if !defined (LDAV_DONE) && defined (__linux__)
 579 #define LDAV_DONE
 580 #undef LOAD_AVE_TYPE
 581
 582 #ifndef LINUX_LDAV_FILE
 583 #define LINUX_LDAV_FILE "/proc/loadavg"
 584 #endif
 585
 586   char ldavgbuf[40];
 587   double load_ave[3];
 588   int fd, count;
 589
 590   fd = open (LINUX_LDAV_FILE, O_RDONLY);
 591   if (fd == -1)
 592     return -1;
 593   count = read (fd, ldavgbuf, 40);
 594   (void) close (fd);
 595   if (count <= 0)
 596     return -1;
 597
 598   count = sscanf (ldavgbuf, "%lf %lf %lf",
 599                   &load_ave[0], &load_ave[1], &load_ave[2]);
 600   if (count < 1)
 601     return -1;
 602
 603   for (elem = 0; elem < nelem && elem < count; elem++)
 604     loadavg[elem] = load_ave[elem];
 605
 606   return elem;
 607
 608 #endif /* __linux__ */
 609
 610 #if !defined (LDAV_DONE) && defined (__NetBSD__)
 611 #define LDAV_DONE
 612 #undef LOAD_AVE_TYPE
 613
 614 #ifndef NETBSD_LDAV_FILE
 615 #define NETBSD_LDAV_FILE "/kern/loadavg"
 616 #endif
 617
 618   unsigned long int load_ave[3], scale;
 619   int count;
 620   FILE *fp;
 621
 622   fp = fopen (NETBSD_LDAV_FILE, "r");
 623   if (fp == NULL)
 624     return -1;
 625   count = fscanf (fp, "%lu %lu %lu %lu\n",
 626                   &load_ave[0], &load_ave[1], &load_ave[2],
 627                   &scale);
 628   (void) fclose (fp);
 629   if (count != 4)
 630     return -1;
 631
 632   for (elem = 0; elem < nelem; elem++)
 633     loadavg[elem] = (double) load_ave[elem] / (double) scale;
 634
 635   return elem;
 636
 637 #endif /* __NetBSD__ */
 638
 639 #if !defined (LDAV_DONE) && defined (NeXT)
 640 #define LDAV_DONE
 641   /* The NeXT code was adapted from iscreen 3.2.  */
 642
 643   host_t host;
 644   struct processor_set_basic_info info;
 645   unsigned info_count;
 646
 647   /* We only know how to get the 1-minute average for this system,
 648      so even if the caller asks for more than 1, we only return 1.  */
 649
 650   if (!getloadavg_initialized)
 651     {
 652       if (processor_set_default (host_self (), &default_set) == KERN_SUCCESS)
 653         getloadavg_initialized = 1;
 654     }
 655
 656   if (getloadavg_initialized)
 657     {
 658       info_count = PROCESSOR_SET_BASIC_INFO_COUNT;
 659       if (processor_set_info (default_set, PROCESSOR_SET_BASIC_INFO, &host,
 660                              (processor_set_info_t) &info, &info_count)
 661           != KERN_SUCCESS)
 662         getloadavg_initialized = 0;
 663       else
 664         {
 665           if (nelem > 0)
 666             loadavg[elem++] = (double) info.load_average / LOAD_SCALE;
 667         }
 668     }
 669
 670   if (!getloadavg_initialized)
 671     return -1;
 672 #endif /* NeXT */
 673
 674 #if !defined (LDAV_DONE) && defined (UMAX)
 675 #define LDAV_DONE
 676 /* UMAX 4.2, which runs on the Encore Multimax multiprocessor, does not
 677    have a /dev/kmem.  Information about the workings of the running kernel
 678    can be gathered with inq_stats system calls.
 679    We only know how to get the 1-minute average for this system.  */
 680
 681   struct proc_summary proc_sum_data;
 682   struct stat_descr proc_info;
 683   double load;
 684   register unsigned int i, j;
 685
 686   if (cpus == 0)
 687     {
 688       register unsigned int c, i;
 689       struct cpu_config conf;
 690       struct stat_descr desc;
 691
 692       desc.sd_next = 0;
 693       desc.sd_subsys = SUBSYS_CPU;
 694       desc.sd_type = CPUTYPE_CONFIG;
 695       desc.sd_addr = (char *) &conf;
 696       desc.sd_size = sizeof conf;
 697
 698       if (inq_stats (1, &desc))
 699         return -1;
 700
 701       c = 0;
 702       for (i = 0; i < conf.config_maxclass; ++i)
 703         {
 704           struct class_stats stats;
 705           bzero ((char *) &stats, sizeof stats);
 706
 707           desc.sd_type = CPUTYPE_CLASS;
 708           desc.sd_objid = i;
 709           desc.sd_addr = (char *) &stats;
 710           desc.sd_size = sizeof stats;
 711
 712           if (inq_stats (1, &desc))
 713             return -1;
 714
 715           c += stats.class_numcpus;
 716         }
 717       cpus = c;
 718       samples = cpus < 2 ? 3 : (2 * cpus / 3);
 719     }
 720
 721   proc_info.sd_next = 0;
 722   proc_info.sd_subsys = SUBSYS_PROC;
 723   proc_info.sd_type = PROCTYPE_SUMMARY;
 724   proc_info.sd_addr = (char *) &proc_sum_data;
 725   proc_info.sd_size = sizeof (struct proc_summary);
 726   proc_info.sd_sizeused = 0;
 727
 728   if (inq_stats (1, &proc_info) != 0)
 729     return -1;
 730
 731   load = proc_sum_data.ps_nrunnable;
 732   j = 0;
 733   for (i = samples - 1; i > 0; --i)
 734     {
 735       load += proc_sum_data.ps_nrun[j];
 736       if (j++ == PS_NRUNSIZE)
 737         j = 0;
 738     }
 739
 740   if (nelem > 0)
 741     loadavg[elem++] = load / samples / cpus;
 742 #endif /* UMAX */
 743
 744 #if !defined (LDAV_DONE) && defined (DGUX)
 745 #define LDAV_DONE
 746   /* This call can return -1 for an error, but with good args
 747      it's not supposed to fail.  The first argument is for no
 748      apparent reason of type `long int *'.  */
 749   dg_sys_info ((long int *) &load_info,
 750                DG_SYS_INFO_LOAD_INFO_TYPE,
 751                DG_SYS_INFO_LOAD_VERSION_0);
 752
 753   if (nelem > 0)
 754     loadavg[elem++] = load_info.one_minute;
 755   if (nelem > 1)
 756     loadavg[elem++] = load_info.five_minute;
 757   if (nelem > 2)
 758     loadavg[elem++] = load_info.fifteen_minute;
 759 #endif /* DGUX */
 760
 761 #if !defined (LDAV_DONE) && defined (apollo)
 762 #define LDAV_DONE
 763 /* Apollo code from lisch@mentorg.com (Ray Lischner).
 764
 765    This system call is not documented.  The load average is obtained as
 766    three long integers, for the load average over the past minute,
 767    five minutes, and fifteen minutes.  Each value is a scaled integer,
 768    with 16 bits of integer part and 16 bits of fraction part.
 769
 770    I'm not sure which operating system first supported this system call,
 771    but I know that SR10.2 supports it.  */
 772
 773   extern void proc1_$get_loadav ();
 774   unsigned long load_ave[3];
 775
 776   proc1_$get_loadav (load_ave);
 777
 778   if (nelem > 0)
 779     loadavg[elem++] = load_ave[0] / 65536.0;
 780   if (nelem > 1)
 781     loadavg[elem++] = load_ave[1] / 65536.0;
 782   if (nelem > 2)
 783     loadavg[elem++] = load_ave[2] / 65536.0;
 784 #endif /* apollo */
 785
 786 #if !defined (LDAV_DONE) && defined (OSF_MIPS)
 787 #define LDAV_DONE
 788
 789   struct tbl_loadavg load_ave;
 790   table (TBL_LOADAVG, 0, &load_ave, 1, sizeof (load_ave));
 791   loadavg[elem++]
 792     = (load_ave.tl_lscale == 0
 793        ? load_ave.tl_avenrun.d[0]
 794        : (load_ave.tl_avenrun.l[0] / (double) load_ave.tl_lscale));
 795 #endif  /* OSF_MIPS */
 796
 797 #if !defined (LDAV_DONE) && (defined (MSDOS) || defined (WIN32))
 798 #define LDAV_DONE
 799
 800   /* A faithful emulation is going to have to be saved for a rainy day.  */
 801   for ( ; elem < nelem; elem++)
 802     {
 803       loadavg[elem] = 0.0;
 804     }
 805 #endif  /* MSDOS */
 806
 807 #if !defined (LDAV_DONE) && defined (OSF_ALPHA)
 808 #define LDAV_DONE
 809
 810   struct tbl_loadavg load_ave;
 811   table (TBL_LOADAVG, 0, &load_ave, 1, sizeof (load_ave));
 812   for (elem = 0; elem < nelem; elem++)
 813     loadavg[elem]
 814       = (load_ave.tl_lscale == 0
 815        ? load_ave.tl_avenrun.d[elem]
 816        : (load_ave.tl_avenrun.l[elem] / (double) load_ave.tl_lscale));
 817 #endif /* OSF_ALPHA */
 818
 819 #if !defined (LDAV_DONE) && defined (VMS)
 820   /* VMS specific code -- read from the Load Ave driver.  */
 821
 822   LOAD_AVE_TYPE load_ave[3];
 823   static int getloadavg_initialized = 0;
 824 #ifdef eunice
 825   struct
 826   {
 827     int dsc$w_length;
 828     char *dsc$a_pointer;
 829   } descriptor;
 830 #endif
 831
 832   /* Ensure that there is a channel open to the load ave device.  */
 833   if (!getloadavg_initialized)
 834     {
 835       /* Attempt to open the channel.  */
 836 #ifdef eunice
 837       descriptor.dsc$w_length = 18;
 838       descriptor.dsc$a_pointer = "$$VMS_LOAD_AVERAGE";
 839 #else
 840       $DESCRIPTOR (descriptor, "LAV0:");
 841 #endif
 842       if (sys$assign (&descriptor, &channel, 0, 0) & 1)
 843         getloadavg_initialized = 1;
 844     }
 845
 846   /* Read the load average vector.  */
 847   if (getloadavg_initialized
 848       && !(sys$qiow (0, channel, IO$_READVBLK, 0, 0, 0,
 849                      load_ave, 12, 0, 0, 0, 0) & 1))
 850     {
 851       sys$dassgn (channel);
 852       getloadavg_initialized = 0;
 853     }
 854
 855   if (!getloadavg_initialized)
 856     return -1;
 857 #endif /* VMS */
 858
 859 #if !defined (LDAV_DONE) && defined(LOAD_AVE_TYPE) && !defined(VMS)
 860
 861   /* UNIX-specific code -- read the average from /dev/kmem.  */
 862
 863 #define LDAV_PRIVILEGED         /* This code requires special installation.  */
 864
 865   LOAD_AVE_TYPE load_ave[3];
 866
 867   /* Get the address of LDAV_SYMBOL.  */
 868   if (offset == 0)
 869     {
 870 #ifndef sgi
 871 #ifndef NLIST_STRUCT
 872       strcpy (nl[0].n_name, LDAV_SYMBOL);
 873       strcpy (nl[1].n_name, "");
 874 #else /* NLIST_STRUCT */
 875 #ifdef NLIST_NAME_UNION
 876       nl[0].n_un.n_name = LDAV_SYMBOL;
 877       nl[1].n_un.n_name = 0;
 878 #else /* not NLIST_NAME_UNION */
 879       nl[0].n_name = LDAV_SYMBOL;
 880       nl[1].n_name = 0;
 881 #endif /* not NLIST_NAME_UNION */
 882 #endif /* NLIST_STRUCT */
 883
 884 #ifndef SUNOS_5
 885       if (
 886 #if !(defined (_AIX) && !defined (ps2))
 887           nlist (KERNEL_FILE, nl)
 888 #else  /* _AIX */
 889           knlist (nl, 1, sizeof (nl[0]))
 890 #endif
 891           >= 0)
 892           /* Omit "&& nl[0].n_type != 0 " -- it breaks on Sun386i.  */
 893           {
 894 #ifdef FIXUP_KERNEL_SYMBOL_ADDR
 895             FIXUP_KERNEL_SYMBOL_ADDR (nl);
 896 #endif
 897             offset = nl[0].n_value;
 898           }
 899 #endif /* !SUNOS_5 */
 900 #else  /* sgi */
 901           int ldav_off;
 902
 903           ldav_off = sysmp (MP_KERNADDR, MPKA_AVENRUN);
 904           if (ldav_off != -1)
 905           offset = (long) ldav_off & 0x7fffffff;
 906 #endif /* sgi */
 907         }
 908
 909   /* Make sure we have /dev/kmem open.  */
 910   if (!getloadavg_initialized)
 911     {
 912 #ifndef SUNOS_5
 913       channel = open ("/dev/kmem", 0);
 914       if (channel >= 0)
 915         {
 916           /* Set the channel to close on exec, so it does not
 917              litter any child's descriptor table.  */
 918 #ifdef FD_SETFD
 919 #ifndef FD_CLOEXEC
 920 #define FD_CLOEXEC 1
 921 #endif
 922           (void) fcntl (channel, F_SETFD, FD_CLOEXEC);
 923 #endif
 924           getloadavg_initialized = 1;
 925         }
 926 #else /* SUNOS_5 */
 927       /* We pass 0 for the kernel, corefile, and swapfile names
 928          to use the currently running kernel.  */
 929       kd = kvm_open (0, 0, 0, O_RDONLY, 0);
 930       if (kd != 0)
 931         {
 932           /* nlist the currently running kernel.  */
 933           kvm_nlist (kd, nl);
 934           offset = nl[0].n_value;
 935           getloadavg_initialized = 1;
 936         }
 937 #endif /* SUNOS_5 */
 938     }
 939
 940   /* If we can, get the load average values.  */
 941   if (offset && getloadavg_initialized)
 942     {
 943       /* Try to read the load.  */
 944 #ifndef SUNOS_5
 945       if (lseek (channel, offset, 0) == -1L
 946           || read (channel, (char *) load_ave, sizeof (load_ave))
 947           != sizeof (load_ave))
 948         {
 949           close (channel);
 950           getloadavg_initialized = 0;
 951         }
 952 #else  /* SUNOS_5 */
 953       if (kvm_read (kd, offset, (char *) load_ave, sizeof (load_ave))
 954           != sizeof (load_ave))
 955         {
 956           kvm_close (kd);
 957           getloadavg_initialized = 0;
 958         }
 959 #endif /* SUNOS_5 */
 960     }
 961
 962   if (offset == 0 || !getloadavg_initialized)
 963     return -1;
 964 #endif /* LOAD_AVE_TYPE and not VMS */
 965
 966 #if !defined (LDAV_DONE) && defined (LOAD_AVE_TYPE) /* Including VMS.  */
 967   if (nelem > 0)
 968     loadavg[elem++] = LDAV_CVT (load_ave[0]);
 969   if (nelem > 1)
 970     loadavg[elem++] = LDAV_CVT (load_ave[1]);
 971   if (nelem > 2)
 972     loadavg[elem++] = LDAV_CVT (load_ave[2]);
 973
 974 #define LDAV_DONE
 975 #endif /* !LDAV_DONE && LOAD_AVE_TYPE */
 976
 977 #ifdef LDAV_DONE
 978   return elem;
 979 #else
 980   /* Set errno to zero to indicate that there was no particular error;
 981      this function just can't work at all on this system.  */
 982   errno = 0;
 983   return -1;
 984 #endif
 985 }
 986
 987 #endif /* ! HAVE_GETLOADAVG */
 988 \f
 989 #ifdef TEST
 990 void
 991 main (argc, argv)
 992      int argc;
 993      char **argv;
 994 {
 995   int naptime = 0;
 996
 997   if (argc > 1)
 998     naptime = atoi (argv[1]);
 999
1000   while (1)
1001     {
1002       double avg[3];
1003       int loads;
1004
1005       errno = 0;                /* Don't be misled if it doesn't set errno.  */
1006       loads = getloadavg (avg, 3);
1007       if (loads == -1)
1008         {
1009           perror ("Error getting load average");
1010           exit (1);
1011         }
1012       if (loads > 0)
1013         printf ("1-minute: %f  ", avg[0]);
1014       if (loads > 1)
1015         printf ("5-minute: %f  ", avg[1]);
1016       if (loads > 2)
1017         printf ("15-minute: %f  ", avg[2]);
1018       if (loads > 0)
1019         putchar ('\n');
1020
1021       if (naptime == 0)
1022         break;
1023       sleep (naptime);
1024     }
1025
1026   exit (0);
1027 }
1028 #endif /* TEST */