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