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 (__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 #    if defined (hpux) && defined (HAVE_PSTAT_GETDYNAMIC)
 411 #     include <sys/pstat.h>
 412 #    endif
 413
 414 #    ifndef KERNEL_FILE
 415 #     define KERNEL_FILE "/vmunix"
 416 #    endif /* KERNEL_FILE */
 417
 418 #    ifndef LDAV_SYMBOL
 419 #     define LDAV_SYMBOL "_avenrun"
 420 #    endif /* LDAV_SYMBOL */
 421 #   endif /* __linux__ */
 422
 423 #  else /* VMS */
 424
 425 #   ifndef eunice
 426 #    include <iodef.h>
 427 #    include <descrip.h>
 428 #   else /* eunice */
 429 #    include <vms/iodef.h>
 430 #   endif /* eunice */
 431 #  endif /* VMS */
 432
 433 #  ifndef LDAV_CVT
 434 #   define LDAV_CVT(n) ((double) (n))
 435 #  endif /* !LDAV_CVT */
 436
 437 # endif /* LOAD_AVE_TYPE */
 438
 439 # ifdef NeXT
 440 #  ifdef HAVE_MACH_MACH_H
 441 #   include <mach/mach.h>
 442 #  else
 443 #   include <mach.h>
 444 #  endif
 445 # endif /* NeXT */
 446
 447 # ifdef sgi
 448 #  include <sys/sysmp.h>
 449 # endif /* sgi */
 450
 451 # ifdef UMAX
 452 #  include <stdio.h>
 453 #  include <signal.h>
 454 #  include <sys/time.h>
 455 #  include <sys/wait.h>
 456 #  include <sys/syscall.h>
 457
 458 #  ifdef UMAX_43
 459 #   include <machine/cpu.h>
 460 #   include <inq_stats/statistics.h>
 461 #   include <inq_stats/sysstats.h>
 462 #   include <inq_stats/cpustats.h>
 463 #   include <inq_stats/procstats.h>
 464 #  else /* Not UMAX_43.  */
 465 #   include <sys/sysdefs.h>
 466 #   include <sys/statistics.h>
 467 #   include <sys/sysstats.h>
 468 #   include <sys/cpudefs.h>
 469 #   include <sys/cpustats.h>
 470 #   include <sys/procstats.h>
 471 #  endif /* Not UMAX_43.  */
 472 # endif /* UMAX */
 473
 474 # ifdef DGUX
 475 #  include <sys/dg_sys_info.h>
 476 # endif
 477
 478 # if defined(HAVE_FCNTL_H) || defined(_POSIX_VERSION)
 479 #  include <fcntl.h>
 480 # else
 481 #  include <sys/file.h>
 482 # endif
 483 \f
 484 /* Avoid static vars inside a function since in HPUX they dump as pure.  */
 485
 486 # ifdef NeXT
 487 static processor_set_t default_set;
 488 static int getloadavg_initialized;
 489 # endif /* NeXT */
 490
 491 # ifdef UMAX
 492 static unsigned int cpus = 0;
 493 static unsigned int samples;
 494 # endif /* UMAX */
 495
 496 # ifdef DGUX
 497 static struct dg_sys_info_load_info load_info;  /* what-a-mouthful! */
 498 # endif /* DGUX */
 499
 500 # ifdef LOAD_AVE_TYPE
 501 /* File descriptor open to /dev/kmem or VMS load ave driver.  */
 502 static int channel;
 503 /* Nonzero iff channel is valid.  */
 504 static int getloadavg_initialized;
 505 /* Offset in kmem to seek to read load average, or 0 means invalid.  */
 506 static long offset;
 507
 508 #  if !defined(VMS) && !defined(sgi) && !defined(__linux__)
 509 static struct nlist nl[2];
 510 #  endif /* Not VMS or sgi */
 511
 512 #  ifdef SUNOS_5
 513 static kvm_t *kd;
 514 #  endif /* SUNOS_5 */
 515
 516 # endif /* LOAD_AVE_TYPE */
 517 \f
 518 /* Put the 1 minute, 5 minute and 15 minute load averages
 519    into the first NELEM elements of LOADAVG.
 520    Return the number written (never more than 3, but may be less than NELEM),
 521    or -1 if an error occurred.  */
 522
 523 int
 524 getloadavg (loadavg, nelem)
 525      double loadavg[];
 526      int nelem;
 527 {
 528   int elem = 0;                 /* Return value.  */
 529
 530 # ifdef NO_GET_LOAD_AVG
 531 #  define LDAV_DONE
 532   /* Set errno to zero to indicate that there was no particular error;
 533      this function just can't work at all on this system.  */
 534   errno = 0;
 535   elem = -1;
 536 # endif
 537
 538 # if !defined (LDAV_DONE) && defined (SUNOS_5)
 539 /* Use libkstat because we don't have to be root.  */
 540 #  define LDAV_DONE
 541   kstat_ctl_t *kc;
 542   kstat_t *ksp;
 543   kstat_named_t *kn;
 544
 545   kc = kstat_open ();
 546   if (kc == 0)
 547     return -1;
 548   ksp = kstat_lookup (kc, "unix", 0, "system_misc");
 549   if (ksp == 0 )
 550     return -1;
 551   if (kstat_read (kc, ksp, 0) == -1)
 552     return -1;
 553
 554
 555   kn = kstat_data_lookup (ksp, "avenrun_1min");
 556   if (kn == 0)
 557     {
 558       /* Return -1 if no load average information is available.  */
 559       nelem = 0;
 560       elem = -1;
 561     }
 562
 563   if (nelem >= 1)
 564     loadavg[elem++] = (double) kn->value.ul/FSCALE;
 565
 566   if (nelem >= 2)
 567     {
 568       kn = kstat_data_lookup (ksp, "avenrun_5min");
 569       if (kn != 0)
 570         {
 571           loadavg[elem++] = (double) kn->value.ul/FSCALE;
 572
 573           if (nelem >= 3)
 574             {
 575               kn = kstat_data_lookup (ksp, "avenrun_15min");
 576               if (kn != 0)
 577                 loadavg[elem++] = (double) kn->value.ul/FSCALE;
 578             }
 579         }
 580     }
 581
 582   kstat_close (kc);
 583 # endif /* SUNOS_5 */
 584
 585 # if !defined (LDAV_DONE) && defined (hpux) && defined (HAVE_PSTAT_GETDYNAMIC)
 586 /* Use pstat_getdynamic() because we don't have to be root.  */
 587 #  define LDAV_DONE
 588 #  undef LOAD_AVE_TYPE
 589
 590   struct pst_dynamic dyn_info;
 591   if (pstat_getdynamic (&dyn_info, sizeof (dyn_info), 0, 0) < 0)
 592     return -1;
 593   if (nelem > 0)
 594     loadavg[elem++] = dyn_info.psd_avg_1_min;
 595   if (nelem > 1)
 596     loadavg[elem++] = dyn_info.psd_avg_5_min;
 597   if (nelem > 2)
 598     loadavg[elem++] = dyn_info.psd_avg_15_min;
 599
 600 # endif /* hpux && HAVE_PSTAT_GETDYNAMIC */
 601
 602 # if !defined (LDAV_DONE) && defined (__linux__)
 603 #  define LDAV_DONE
 604 #  undef LOAD_AVE_TYPE
 605
 606 #  ifndef LINUX_LDAV_FILE
 607 #   define LINUX_LDAV_FILE "/proc/loadavg"
 608 #  endif
 609
 610   char ldavgbuf[40];
 611   double load_ave[3];
 612   int fd, count;
 613
 614   fd = open (LINUX_LDAV_FILE, O_RDONLY);
 615   if (fd == -1)
 616     return -1;
 617   count = read (fd, ldavgbuf, 40);
 618   (void) close (fd);
 619   if (count <= 0)
 620     return -1;
 621
 622   count = sscanf (ldavgbuf, "%lf %lf %lf",
 623                   &load_ave[0], &load_ave[1], &load_ave[2]);
 624   if (count < 1)
 625     return -1;
 626
 627   for (elem = 0; elem < nelem && elem < count; elem++)
 628     loadavg[elem] = load_ave[elem];
 629
 630   return elem;
 631
 632 # endif /* __linux__ */
 633
 634 # if !defined (LDAV_DONE) && defined (__NetBSD__)
 635 #  define LDAV_DONE
 636 #  undef LOAD_AVE_TYPE
 637
 638 #  ifndef NETBSD_LDAV_FILE
 639 #   define NETBSD_LDAV_FILE "/kern/loadavg"
 640 #  endif
 641
 642   unsigned long int load_ave[3], scale;
 643   int count;
 644   FILE *fp;
 645
 646   fp = fopen (NETBSD_LDAV_FILE, "r");
 647   if (fp == NULL)
 648     return -1;
 649   count = fscanf (fp, "%lu %lu %lu %lu\n",
 650                   &load_ave[0], &load_ave[1], &load_ave[2],
 651                   &scale);
 652   (void) fclose (fp);
 653   if (count != 4)
 654     return -1;
 655
 656   for (elem = 0; elem < nelem; elem++)
 657     loadavg[elem] = (double) load_ave[elem] / (double) scale;
 658
 659   return elem;
 660
 661 # endif /* __NetBSD__ */
 662
 663 # if !defined (LDAV_DONE) && defined (NeXT)
 664 #  define LDAV_DONE
 665   /* The NeXT code was adapted from iscreen 3.2.  */
 666
 667   host_t host;
 668   struct processor_set_basic_info info;
 669   unsigned info_count;
 670
 671   /* We only know how to get the 1-minute average for this system,
 672      so even if the caller asks for more than 1, we only return 1.  */
 673
 674   if (!getloadavg_initialized)
 675     {
 676       if (processor_set_default (host_self (), &default_set) == KERN_SUCCESS)
 677         getloadavg_initialized = 1;
 678     }
 679
 680   if (getloadavg_initialized)
 681     {
 682       info_count = PROCESSOR_SET_BASIC_INFO_COUNT;
 683       if (processor_set_info (default_set, PROCESSOR_SET_BASIC_INFO, &host,
 684                               (processor_set_info_t) &info, &info_count)
 685           != KERN_SUCCESS)
 686         getloadavg_initialized = 0;
 687       else
 688         {
 689           if (nelem > 0)
 690             loadavg[elem++] = (double) info.load_average / LOAD_SCALE;
 691         }
 692     }
 693
 694   if (!getloadavg_initialized)
 695     return -1;
 696 # endif /* NeXT */
 697
 698 # if !defined (LDAV_DONE) && defined (UMAX)
 699 #  define LDAV_DONE
 700 /* UMAX 4.2, which runs on the Encore Multimax multiprocessor, does not
 701    have a /dev/kmem.  Information about the workings of the running kernel
 702    can be gathered with inq_stats system calls.
 703    We only know how to get the 1-minute average for this system.  */
 704
 705   struct proc_summary proc_sum_data;
 706   struct stat_descr proc_info;
 707   double load;
 708   register unsigned int i, j;
 709
 710   if (cpus == 0)
 711     {
 712       register unsigned int c, i;
 713       struct cpu_config conf;
 714       struct stat_descr desc;
 715
 716       desc.sd_next = 0;
 717       desc.sd_subsys = SUBSYS_CPU;
 718       desc.sd_type = CPUTYPE_CONFIG;
 719       desc.sd_addr = (char *) &conf;
 720       desc.sd_size = sizeof conf;
 721
 722       if (inq_stats (1, &desc))
 723         return -1;
 724
 725       c = 0;
 726       for (i = 0; i < conf.config_maxclass; ++i)
 727         {
 728           struct class_stats stats;
 729           bzero ((char *) &stats, sizeof stats);
 730
 731           desc.sd_type = CPUTYPE_CLASS;
 732           desc.sd_objid = i;
 733           desc.sd_addr = (char *) &stats;
 734           desc.sd_size = sizeof stats;
 735
 736           if (inq_stats (1, &desc))
 737             return -1;
 738
 739           c += stats.class_numcpus;
 740         }
 741       cpus = c;
 742       samples = cpus < 2 ? 3 : (2 * cpus / 3);
 743     }
 744
 745   proc_info.sd_next = 0;
 746   proc_info.sd_subsys = SUBSYS_PROC;
 747   proc_info.sd_type = PROCTYPE_SUMMARY;
 748   proc_info.sd_addr = (char *) &proc_sum_data;
 749   proc_info.sd_size = sizeof (struct proc_summary);
 750   proc_info.sd_sizeused = 0;
 751
 752   if (inq_stats (1, &proc_info) != 0)
 753     return -1;
 754
 755   load = proc_sum_data.ps_nrunnable;
 756   j = 0;
 757   for (i = samples - 1; i > 0; --i)
 758     {
 759       load += proc_sum_data.ps_nrun[j];
 760       if (j++ == PS_NRUNSIZE)
 761         j = 0;
 762     }
 763
 764   if (nelem > 0)
 765     loadavg[elem++] = load / samples / cpus;
 766 # endif /* UMAX */
 767
 768 # if !defined (LDAV_DONE) && defined (DGUX)
 769 #  define LDAV_DONE
 770   /* This call can return -1 for an error, but with good args
 771      it's not supposed to fail.  The first argument is for no
 772      apparent reason of type `long int *'.  */
 773   dg_sys_info ((long int *) &load_info,
 774                DG_SYS_INFO_LOAD_INFO_TYPE,
 775                DG_SYS_INFO_LOAD_VERSION_0);
 776
 777   if (nelem > 0)
 778     loadavg[elem++] = load_info.one_minute;
 779   if (nelem > 1)
 780     loadavg[elem++] = load_info.five_minute;
 781   if (nelem > 2)
 782     loadavg[elem++] = load_info.fifteen_minute;
 783 # endif /* DGUX */
 784
 785 # if !defined (LDAV_DONE) && defined (apollo)
 786 #  define LDAV_DONE
 787 /* Apollo code from lisch@mentorg.com (Ray Lischner).
 788
 789    This system call is not documented.  The load average is obtained as
 790    three long integers, for the load average over the past minute,
 791    five minutes, and fifteen minutes.  Each value is a scaled integer,
 792    with 16 bits of integer part and 16 bits of fraction part.
 793
 794    I'm not sure which operating system first supported this system call,
 795    but I know that SR10.2 supports it.  */
 796
 797   extern void proc1_$get_loadav ();
 798   unsigned long load_ave[3];
 799
 800   proc1_$get_loadav (load_ave);
 801
 802   if (nelem > 0)
 803     loadavg[elem++] = load_ave[0] / 65536.0;
 804   if (nelem > 1)
 805     loadavg[elem++] = load_ave[1] / 65536.0;
 806   if (nelem > 2)
 807     loadavg[elem++] = load_ave[2] / 65536.0;
 808 # endif /* apollo */
 809
 810 # if !defined (LDAV_DONE) && defined (OSF_MIPS)
 811 #  define LDAV_DONE
 812
 813   struct tbl_loadavg load_ave;
 814   table (TBL_LOADAVG, 0, &load_ave, 1, sizeof (load_ave));
 815   loadavg[elem++]
 816     = (load_ave.tl_lscale == 0
 817        ? load_ave.tl_avenrun.d[0]
 818        : (load_ave.tl_avenrun.l[0] / (double) load_ave.tl_lscale));
 819 # endif /* OSF_MIPS */
 820
 821 # if !defined (LDAV_DONE) && (defined (MSDOS) || defined (WIN32))
 822 #  define LDAV_DONE
 823
 824   /* A faithful emulation is going to have to be saved for a rainy day.  */
 825   for ( ; elem < nelem; elem++)
 826     {
 827       loadavg[elem] = 0.0;
 828     }
 829 # endif  /* MSDOS */
 830
 831 # if !defined (LDAV_DONE) && defined (OSF_ALPHA)
 832 #  define LDAV_DONE
 833
 834   struct tbl_loadavg load_ave;
 835   table (TBL_LOADAVG, 0, &load_ave, 1, sizeof (load_ave));
 836   for (elem = 0; elem < nelem; elem++)
 837     loadavg[elem]
 838       = (load_ave.tl_lscale == 0
 839        ? load_ave.tl_avenrun.d[elem]
 840        : (load_ave.tl_avenrun.l[elem] / (double) load_ave.tl_lscale));
 841 # endif /* OSF_ALPHA */
 842
 843 # if !defined (LDAV_DONE) && defined (VMS)
 844   /* VMS specific code -- read from the Load Ave driver.  */
 845
 846   LOAD_AVE_TYPE load_ave[3];
 847   static int getloadavg_initialized = 0;
 848 #  ifdef eunice
 849   struct
 850   {
 851     int dsc$w_length;
 852     char *dsc$a_pointer;
 853   } descriptor;
 854 #  endif
 855
 856   /* Ensure that there is a channel open to the load ave device.  */
 857   if (!getloadavg_initialized)
 858     {
 859       /* Attempt to open the channel.  */
 860 #  ifdef eunice
 861       descriptor.dsc$w_length = 18;
 862       descriptor.dsc$a_pointer = "$$VMS_LOAD_AVERAGE";
 863 #  else
 864       $DESCRIPTOR (descriptor, "LAV0:");
 865 #  endif
 866       if (sys$assign (&descriptor, &channel, 0, 0) & 1)
 867         getloadavg_initialized = 1;
 868     }
 869
 870   /* Read the load average vector.  */
 871   if (getloadavg_initialized
 872       && !(sys$qiow (0, channel, IO$_READVBLK, 0, 0, 0,
 873                      load_ave, 12, 0, 0, 0, 0) & 1))
 874     {
 875       sys$dassgn (channel);
 876       getloadavg_initialized = 0;
 877     }
 878
 879   if (!getloadavg_initialized)
 880     return -1;
 881 # endif /* VMS */
 882
 883 # if !defined (LDAV_DONE) && defined(LOAD_AVE_TYPE) && !defined(VMS)
 884
 885   /* UNIX-specific code -- read the average from /dev/kmem.  */
 886
 887 #  define LDAV_PRIVILEGED               /* This code requires special installation.  */
 888
 889   LOAD_AVE_TYPE load_ave[3];
 890
 891   /* Get the address of LDAV_SYMBOL.  */
 892   if (offset == 0)
 893     {
 894 #  ifndef sgi
 895 #   ifndef NLIST_STRUCT
 896       strcpy (nl[0].n_name, LDAV_SYMBOL);
 897       strcpy (nl[1].n_name, "");
 898 #   else /* NLIST_STRUCT */
 899 #    ifdef NLIST_NAME_UNION
 900       nl[0].n_un.n_name = LDAV_SYMBOL;
 901       nl[1].n_un.n_name = 0;
 902 #    else /* not NLIST_NAME_UNION */
 903       nl[0].n_name = LDAV_SYMBOL;
 904       nl[1].n_name = 0;
 905 #    endif /* not NLIST_NAME_UNION */
 906 #   endif /* NLIST_STRUCT */
 907
 908 #   ifndef SUNOS_5
 909       if (
 910 #    if !(defined (_AIX) && !defined (ps2))
 911           nlist (KERNEL_FILE, nl)
 912 #    else  /* _AIX */
 913           knlist (nl, 1, sizeof (nl[0]))
 914 #    endif
 915           >= 0)
 916           /* Omit "&& nl[0].n_type != 0 " -- it breaks on Sun386i.  */
 917           {
 918 #    ifdef FIXUP_KERNEL_SYMBOL_ADDR
 919             FIXUP_KERNEL_SYMBOL_ADDR (nl);
 920 #    endif
 921             offset = nl[0].n_value;
 922           }
 923 #   endif /* !SUNOS_5 */
 924 #  else  /* sgi */
 925       int ldav_off;
 926
 927       ldav_off = sysmp (MP_KERNADDR, MPKA_AVENRUN);
 928       if (ldav_off != -1)
 929         offset = (long) ldav_off & 0x7fffffff;
 930 #  endif /* sgi */
 931     }
 932
 933   /* Make sure we have /dev/kmem open.  */
 934   if (!getloadavg_initialized)
 935     {
 936 #  ifndef SUNOS_5
 937       channel = open ("/dev/kmem", 0);
 938       if (channel >= 0)
 939         {
 940           /* Set the channel to close on exec, so it does not
 941              litter any child's descriptor table.  */
 942 #   ifdef FD_SETFD
 943 #    ifndef FD_CLOEXEC
 944 #     define FD_CLOEXEC 1
 945 #    endif
 946           (void) fcntl (channel, F_SETFD, FD_CLOEXEC);
 947 #   endif
 948           getloadavg_initialized = 1;
 949         }
 950 #  else /* SUNOS_5 */
 951       /* We pass 0 for the kernel, corefile, and swapfile names
 952          to use the currently running kernel.  */
 953       kd = kvm_open (0, 0, 0, O_RDONLY, 0);
 954       if (kd != 0)
 955         {
 956           /* nlist the currently running kernel.  */
 957           kvm_nlist (kd, nl);
 958           offset = nl[0].n_value;
 959           getloadavg_initialized = 1;
 960         }
 961 #  endif /* SUNOS_5 */
 962     }
 963
 964   /* If we can, get the load average values.  */
 965   if (offset && getloadavg_initialized)
 966     {
 967       /* Try to read the load.  */
 968 #  ifndef SUNOS_5
 969       if (lseek (channel, offset, 0) == -1L
 970           || read (channel, (char *) load_ave, sizeof (load_ave))
 971           != sizeof (load_ave))
 972         {
 973           close (channel);
 974           getloadavg_initialized = 0;
 975         }
 976 #  else  /* SUNOS_5 */
 977       if (kvm_read (kd, offset, (char *) load_ave, sizeof (load_ave))
 978           != sizeof (load_ave))
 979         {
 980           kvm_close (kd);
 981           getloadavg_initialized = 0;
 982         }
 983 #  endif /* SUNOS_5 */
 984     }
 985
 986   if (offset == 0 || !getloadavg_initialized)
 987     return -1;
 988 # endif /* LOAD_AVE_TYPE and not VMS */
 989
 990 # if !defined (LDAV_DONE) && defined (LOAD_AVE_TYPE) /* Including VMS.  */
 991   if (nelem > 0)
 992     loadavg[elem++] = LDAV_CVT (load_ave[0]);
 993   if (nelem > 1)
 994     loadavg[elem++] = LDAV_CVT (load_ave[1]);
 995   if (nelem > 2)
 996     loadavg[elem++] = LDAV_CVT (load_ave[2]);
 997
 998 #  define LDAV_DONE
 999 # endif /* !LDAV_DONE && LOAD_AVE_TYPE */
1000
1001 # ifdef LDAV_DONE
1002   return elem;
1003 # else
1004   /* Set errno to zero to indicate that there was no particular error;
1005      this function just can't work at all on this system.  */
1006   errno = 0;
1007   return -1;
1008 # endif
1009 }
1010
1011 #endif /* ! HAVE_GETLOADAVG */
1012 \f
1013 #ifdef TEST
1014 void
1015 main (argc, argv)
1016      int argc;
1017      char **argv;
1018 {
1019   int naptime = 0;
1020
1021   if (argc > 1)
1022     naptime = atoi (argv[1]);
1023
1024   while (1)
1025     {
1026       double avg[3];
1027       int loads;
1028
1029       errno = 0;                /* Don't be misled if it doesn't set errno.  */
1030       loads = getloadavg (avg, 3);
1031       if (loads == -1)
1032         {
1033           perror ("Error getting load average");
1034           exit (1);
1035         }
1036       if (loads > 0)
1037         printf ("1-minute: %f  ", avg[0]);
1038       if (loads > 1)
1039         printf ("5-minute: %f  ", avg[1]);
1040       if (loads > 2)
1041         printf ("15-minute: %f  ", avg[2]);
1042       if (loads > 0)
1043         putchar ('\n');
1044
1045       if (naptime == 0)
1046         break;
1047       sleep (naptime);
1048     }
1049
1050   exit (0);
1051 }
1052 #endif /* TEST */