nptl/perf.c

   1 /* Copyright (C) 2002-2021 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library 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 GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #define _GNU_SOURCE     1
  20 #include <argp.h>
  21 #include <error.h>
  22 #include <errno.h>
  23 #include <fcntl.h>
  24 #include <inttypes.h>
  25 #include <limits.h>
  26 #include <pthread.h>
  27 #include <signal.h>
  28 #include <stdbool.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <time.h>
  32 #include <unistd.h>
  33 #include <sys/param.h>
  34 #include <sys/types.h>
  35
  36 #ifndef MAX_THREADS
  37 # define MAX_THREADS            100000
  38 #endif
  39 #ifndef DEFAULT_THREADS
  40 # define DEFAULT_THREADS        50
  41 #endif
  42
  43
  44 #define OPT_TO_THREAD           300
  45 #define OPT_TO_PROCESS          301
  46 #define OPT_SYNC_SIGNAL         302
  47 #define OPT_SYNC_JOIN           303
  48 #define OPT_TOPLEVEL            304
  49
  50
  51 static const struct argp_option options[] =
  52   {
  53     { NULL, 0, NULL, 0, "\
  54 This is a test for threads so we allow ther user to selection the number of \
  55 threads which are used at any one time.  Independently the total number of \
  56 rounds can be selected.  This is the total number of threads which will have \
  57 run when the process terminates:" },
  58     { "threads", 't', "NUMBER", 0, "Number of threads used at once" },
  59     { "starts", 's', "NUMBER", 0, "Total number of working threads" },
  60     { "toplevel", OPT_TOPLEVEL, "NUMBER", 0,
  61       "Number of toplevel threads which start the other threads; this \
  62 implies --sync-join" },
  63
  64     { NULL, 0, NULL, 0, "\
  65 Each thread can do one of two things: sleep or do work.  The latter is 100% \
  66 CPU bound.  The work load is the probability a thread does work.  All values \
  67 from zero to 100 (inclusive) are valid.  How often each thread repeats this \
  68 can be determined by the number of rounds.  The work cost determines how long \
  69 each work session (not sleeping) takes.  If it is zero a thread would \
  70 effectively nothing.  By setting the number of rounds to zero the thread \
  71 does no work at all and pure thread creation times can be measured." },
  72     { "workload", 'w', "PERCENT", 0, "Percentage of time spent working" },
  73     { "workcost", 'c', "NUMBER", 0,
  74       "Factor in the cost of each round of working" },
  75     { "rounds", 'r', "NUMBER", 0, "Number of rounds each thread runs" },
  76
  77     { NULL, 0, NULL, 0, "\
  78 There are a number of different methods how thread creation can be \
  79 synchronized.  Synchronization is necessary since the number of concurrently \
  80 running threads is limited." },
  81     { "sync-signal", OPT_SYNC_SIGNAL, NULL, 0,
  82       "Synchronize using a signal (default)" },
  83     { "sync-join", OPT_SYNC_JOIN, NULL, 0, "Synchronize using pthread_join" },
  84
  85     { NULL, 0, NULL, 0, "\
  86 One parameter for each threads execution is the size of the stack.  If this \
  87 parameter is not used the system's default stack size is used.  If many \
  88 threads are used the stack size should be chosen quite small." },
  89     { "stacksize", 'S', "BYTES", 0, "Size of threads stack" },
  90     { "guardsize", 'g', "BYTES", 0,
  91       "Size of stack guard area; must fit into the stack" },
  92
  93     { NULL, 0, NULL, 0, "Signal options:" },
  94     { "to-thread", OPT_TO_THREAD, NULL, 0, "Send signal to main thread" },
  95     { "to-process", OPT_TO_PROCESS, NULL, 0,
  96       "Send signal to process (default)" },
  97
  98     { NULL, 0, NULL, 0, "Administrative options:" },
  99     { "progress", 'p', NULL, 0, "Show signs of progress" },
 100     { "timing", 'T', NULL, 0,
 101       "Measure time from startup to the last thread finishing" },
 102     { NULL, 0, NULL, 0, NULL }
 103   };
 104
 105 /* Prototype for option handler.  */
 106 static error_t parse_opt (int key, char *arg, struct argp_state *state);
 107
 108 /* Data structure to communicate with argp functions.  */
 109 static struct argp argp =
 110 {
 111   options, parse_opt
 112 };
 113
 114
 115 static unsigned long int threads = DEFAULT_THREADS;
 116 static unsigned long int workload = 75;
 117 static unsigned long int workcost = 20;
 118 static unsigned long int rounds = 10;
 119 static long int starts = 5000;
 120 static unsigned long int stacksize;
 121 static long int guardsize = -1;
 122 static bool progress;
 123 static bool timing;
 124 static bool to_thread;
 125 static unsigned long int toplevel = 1;
 126
 127
 128 static long int running;
 129 static pthread_mutex_t running_mutex = PTHREAD_MUTEX_INITIALIZER;
 130
 131 static pid_t pid;
 132 static pthread_t tmain;
 133
 134 static clockid_t cl;
 135 static struct timespec start_time;
 136
 137
 138 static pthread_mutex_t sum_mutex = PTHREAD_MUTEX_INITIALIZER;
 139 unsigned int sum;
 140
 141 static enum
 142   {
 143     sync_signal,
 144     sync_join
 145   }
 146 sync_method;
 147
 148
 149 /* We use 64bit values for the times.  */
 150 typedef unsigned long long int hp_timing_t;
 151
 152
 153 /* Attributes for all created threads.  */
 154 static pthread_attr_t attr;
 155
 156
 157 static void *
 158 work (void *arg)
 159 {
 160   unsigned long int i;
 161   unsigned int state = (unsigned long int) arg;
 162
 163   for (i = 0; i < rounds; ++i)
 164     {
 165       /* Determine what to do.  */
 166       unsigned int rnum;
 167
 168       /* Uniform distribution.  */
 169       do
 170         rnum = rand_r (&state);
 171       while (rnum >= UINT_MAX - (UINT_MAX % 100));
 172
 173       rnum %= 100;
 174
 175       if (rnum < workload)
 176         {
 177           int j;
 178           int a[4] = { i, rnum, i + rnum, rnum - i };
 179
 180           if (progress)
 181             write (STDERR_FILENO, "c", 1);
 182
 183           for (j = 0; j < workcost; ++j)
 184             {
 185               a[0] += a[3] >> 12;
 186               a[1] += a[2] >> 20;
 187               a[2] += a[1] ^ 0x3423423;
 188               a[3] += a[0] - a[1];
 189             }
 190
 191           pthread_mutex_lock (&sum_mutex);
 192           sum += a[0] + a[1] + a[2] + a[3];
 193           pthread_mutex_unlock (&sum_mutex);
 194         }
 195       else
 196         {
 197           /* Just sleep.  */
 198           struct timespec tv;
 199
 200           tv.tv_sec = 0;
 201           tv.tv_nsec = 10000000;
 202
 203           if (progress)
 204             write (STDERR_FILENO, "w", 1);
 205
 206           nanosleep (&tv, NULL);
 207         }
 208     }
 209
 210   return NULL;
 211 }
 212
 213
 214 static void *
 215 thread_function (void *arg)
 216 {
 217   work (arg);
 218
 219   pthread_mutex_lock (&running_mutex);
 220   if (--running <= 0 && starts <= 0)
 221     {
 222       /* We are done.  */
 223       if (progress)
 224         write (STDERR_FILENO, "\n", 1);
 225
 226       if (timing)
 227         {
 228           struct timespec end_time;
 229
 230           if (clock_gettime (cl, &end_time) == 0)
 231             {
 232               end_time.tv_sec -= start_time.tv_sec;
 233               end_time.tv_nsec -= start_time.tv_nsec;
 234               if (end_time.tv_nsec < 0)
 235                 {
 236                   end_time.tv_nsec += 1000000000;
 237                   --end_time.tv_sec;
 238                 }
 239
 240               printf ("\nRuntime: %lu.%09lu seconds\n",
 241                       (unsigned long int) end_time.tv_sec,
 242                       (unsigned long int) end_time.tv_nsec);
 243             }
 244         }
 245
 246       printf ("Result: %08x\n", sum);
 247
 248       exit (0);
 249     }
 250   pthread_mutex_unlock (&running_mutex);
 251
 252   if (sync_method == sync_signal)
 253     {
 254       if (to_thread)
 255         /* This code sends a signal to the main thread.  */
 256         pthread_kill (tmain, SIGUSR1);
 257       else
 258         /* Use this code to test sending a signal to the process.  */
 259         kill (pid, SIGUSR1);
 260     }
 261
 262   if (progress)
 263     write (STDERR_FILENO, "f", 1);
 264
 265   return NULL;
 266 }
 267
 268
 269 struct start_info
 270 {
 271   unsigned int starts;
 272   unsigned int threads;
 273 };
 274
 275
 276 static void *
 277 start_threads (void *arg)
 278 {
 279   struct start_info *si = arg;
 280   unsigned int starts = si->starts;
 281   pthread_t ths[si->threads];
 282   unsigned int state = starts;
 283   unsigned int n;
 284   unsigned int i = 0;
 285   int err;
 286
 287   if (progress)
 288     write (STDERR_FILENO, "T", 1);
 289
 290   memset (ths, '\0', sizeof (pthread_t) * si->threads);
 291
 292   while (starts-- > 0)
 293     {
 294       if (ths[i] != 0)
 295         {
 296           /* Wait for the threads in the order they were created.  */
 297           err = pthread_join (ths[i], NULL);
 298           if (err != 0)
 299             error (EXIT_FAILURE, err, "cannot join thread");
 300
 301           if (progress)
 302             write (STDERR_FILENO, "f", 1);
 303         }
 304
 305       err = pthread_create (&ths[i], &attr, work,
 306                             (void *) (long) (rand_r (&state) + starts + i));
 307
 308       if (err != 0)
 309         error (EXIT_FAILURE, err, "cannot start thread");
 310
 311       if (progress)
 312         write (STDERR_FILENO, "t", 1);
 313
 314       if (++i == si->threads)
 315         i = 0;
 316     }
 317
 318   n = i;
 319   do
 320     {
 321       if (ths[i] != 0)
 322         {
 323           err = pthread_join (ths[i], NULL);
 324           if (err != 0)
 325             error (EXIT_FAILURE, err, "cannot join thread");
 326
 327           if (progress)
 328             write (STDERR_FILENO, "f", 1);
 329         }
 330
 331       if (++i == si->threads)
 332         i = 0;
 333     }
 334   while (i != n);
 335
 336   if (progress)
 337     write (STDERR_FILENO, "F", 1);
 338
 339   return NULL;
 340 }
 341
 342
 343 int
 344 main (int argc, char *argv[])
 345 {
 346   int remaining;
 347   sigset_t ss;
 348   pthread_t th;
 349   pthread_t *ths = NULL;
 350   int empty = 0;
 351   int last;
 352   bool cont = true;
 353
 354   /* Parse and process arguments.  */
 355   argp_parse (&argp, argc, argv, 0, &remaining, NULL);
 356
 357   if (sync_method == sync_join)
 358     {
 359       ths = (pthread_t *) calloc (threads, sizeof (pthread_t));
 360       if (ths == NULL)
 361         error (EXIT_FAILURE, errno,
 362                "cannot allocate memory for thread descriptor array");
 363
 364       last = threads;
 365     }
 366   else
 367     {
 368       ths = &th;
 369       last = 1;
 370     }
 371
 372   if (toplevel > threads)
 373     {
 374       printf ("resetting number of toplevel threads to %lu to not surpass number to concurrent threads\n",
 375               threads);
 376       toplevel = threads;
 377     }
 378
 379   if (timing)
 380     {
 381       if (clock_getcpuclockid (0, &cl) != 0
 382           || clock_gettime (cl, &start_time) != 0)
 383         timing = false;
 384     }
 385
 386   /* We need this later.  */
 387   pid = getpid ();
 388   tmain = pthread_self ();
 389
 390   /* We use signal SIGUSR1 for communication between the threads and
 391      the main thread.  We only want sychronous notification.  */
 392   if (sync_method == sync_signal)
 393     {
 394       sigemptyset (&ss);
 395       sigaddset (&ss, SIGUSR1);
 396       if (sigprocmask (SIG_BLOCK, &ss, NULL) != 0)
 397         error (EXIT_FAILURE, errno, "cannot set signal mask");
 398     }
 399
 400   /* Create the thread attributes.  */
 401   pthread_attr_init (&attr);
 402
 403   /* If the user provided a stack size use it.  */
 404   if (stacksize != 0
 405       && pthread_attr_setstacksize (&attr, stacksize) != 0)
 406     puts ("could not set stack size; will use default");
 407   /* And stack guard size.  */
 408   if (guardsize != -1
 409       && pthread_attr_setguardsize (&attr, guardsize) != 0)
 410     puts ("invalid stack guard size; will use default");
 411
 412   /* All threads are created detached if we are not using pthread_join
 413      to synchronize.  */
 414   if (sync_method != sync_join)
 415     pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
 416
 417   if (sync_method == sync_signal)
 418     {
 419       while (1)
 420         {
 421           int err;
 422           bool do_wait = false;
 423
 424           pthread_mutex_lock (&running_mutex);
 425           if (starts-- < 0)
 426             cont = false;
 427           else
 428             do_wait = ++running >= threads && starts > 0;
 429
 430           pthread_mutex_unlock (&running_mutex);
 431
 432           if (! cont)
 433             break;
 434
 435           if (progress)
 436             write (STDERR_FILENO, "t", 1);
 437
 438           err = pthread_create (&ths[empty], &attr, thread_function,
 439                                 (void *) starts);
 440           if (err != 0)
 441             error (EXIT_FAILURE, err, "cannot start thread %lu", starts);
 442
 443           if (++empty == last)
 444             empty = 0;
 445
 446           if (do_wait)
 447             sigwaitinfo (&ss, NULL);
 448         }
 449
 450       /* Do nothing anymore.  On of the threads will terminate the program.  */
 451       sigfillset (&ss);
 452       sigdelset (&ss, SIGINT);
 453       while (1)
 454         sigsuspend (&ss);
 455     }
 456   else
 457     {
 458       pthread_t ths[toplevel];
 459       struct start_info si[toplevel];
 460       unsigned int i;
 461
 462       for (i = 0; i < toplevel; ++i)
 463         {
 464           unsigned int child_starts = starts / (toplevel - i);
 465           unsigned int child_threads = threads / (toplevel - i);
 466           int err;
 467
 468           si[i].starts = child_starts;
 469           si[i].threads = child_threads;
 470
 471           err = pthread_create (&ths[i], &attr, start_threads, &si[i]);
 472           if (err != 0)
 473             error (EXIT_FAILURE, err, "cannot start thread");
 474
 475           starts -= child_starts;
 476           threads -= child_threads;
 477         }
 478
 479       for (i = 0; i < toplevel; ++i)
 480         {
 481           int err = pthread_join (ths[i], NULL);
 482
 483           if (err != 0)
 484             error (EXIT_FAILURE, err, "cannot join thread");
 485         }
 486
 487       /* We are done.  */
 488       if (progress)
 489         write (STDERR_FILENO, "\n", 1);
 490
 491       if (timing)
 492         {
 493           struct timespec end_time;
 494
 495           if (clock_gettime (cl, &end_time) == 0)
 496             {
 497               end_time.tv_sec -= start_time.tv_sec;
 498               end_time.tv_nsec -= start_time.tv_nsec;
 499               if (end_time.tv_nsec < 0)
 500                 {
 501                   end_time.tv_nsec += 1000000000;
 502                   --end_time.tv_sec;
 503                 }
 504
 505               printf ("\nRuntime: %lu.%09lu seconds\n",
 506                       (unsigned long int) end_time.tv_sec,
 507                       (unsigned long int) end_time.tv_nsec);
 508             }
 509         }
 510
 511       printf ("Result: %08x\n", sum);
 512
 513       exit (0);
 514     }
 515
 516   /* NOTREACHED */
 517   return 0;
 518 }
 519
 520
 521 /* Handle program arguments.  */
 522 static error_t
 523 parse_opt (int key, char *arg, struct argp_state *state)
 524 {
 525   unsigned long int num;
 526   long int snum;
 527
 528   switch (key)
 529     {
 530     case 't':
 531       num = strtoul (arg, NULL, 0);
 532       if (num <= MAX_THREADS)
 533         threads = num;
 534       else
 535         printf ("\
 536 number of threads limited to %u; recompile with a higher limit if necessary",
 537                 MAX_THREADS);
 538       break;
 539
 540     case 'w':
 541       num = strtoul (arg, NULL, 0);
 542       if (num <= 100)
 543         workload = num;
 544       else
 545         puts ("workload must be between 0 and 100 percent");
 546       break;
 547
 548     case 'c':
 549       workcost = strtoul (arg, NULL, 0);
 550       break;
 551
 552     case 'r':
 553       rounds = strtoul (arg, NULL, 0);
 554       break;
 555
 556     case 's':
 557       starts = strtoul (arg, NULL, 0);
 558       break;
 559
 560     case 'S':
 561       num = strtoul (arg, NULL, 0);
 562       if (num >= PTHREAD_STACK_MIN)
 563         stacksize = num;
 564       else
 565         printf ("minimum stack size is %d\n", PTHREAD_STACK_MIN);
 566       break;
 567
 568     case 'g':
 569       snum = strtol (arg, NULL, 0);
 570       if (snum < 0)
 571         printf ("invalid guard size %s\n", arg);
 572       else
 573         guardsize = snum;
 574       break;
 575
 576     case 'p':
 577       progress = true;
 578       break;
 579
 580     case 'T':
 581       timing = true;
 582       break;
 583
 584     case OPT_TO_THREAD:
 585       to_thread = true;
 586       break;
 587
 588     case OPT_TO_PROCESS:
 589       to_thread = false;
 590       break;
 591
 592     case OPT_SYNC_SIGNAL:
 593       sync_method = sync_signal;
 594       break;
 595
 596     case OPT_SYNC_JOIN:
 597       sync_method = sync_join;
 598       break;
 599
 600     case OPT_TOPLEVEL:
 601       num = strtoul (arg, NULL, 0);
 602       if (num < MAX_THREADS)
 603         toplevel = num;
 604       else
 605         printf ("\
 606 number of threads limited to %u; recompile with a higher limit if necessary",
 607                 MAX_THREADS);
 608       sync_method = sync_join;
 609       break;
 610
 611     default:
 612       return ARGP_ERR_UNKNOWN;
 613     }
 614
 615   return 0;
 616 }
 617
 618
 619 static hp_timing_t
 620 get_clockfreq (void)
 621 {
 622   /* We read the information from the /proc filesystem.  It contains at
 623      least one line like
 624         cpu MHz         : 497.840237
 625      or also
 626         cpu MHz         : 497.841
 627      We search for this line and convert the number in an integer.  */
 628   static hp_timing_t result;
 629   int fd;
 630
 631   /* If this function was called before, we know the result.  */
 632   if (result != 0)
 633     return result;
 634
 635   fd = open ("/proc/cpuinfo", O_RDONLY);
 636   if (__glibc_likely (fd != -1))
 637     {
 638       /* XXX AFAIK the /proc filesystem can generate "files" only up
 639          to a size of 4096 bytes.  */
 640       char buf[4096];
 641       ssize_t n;
 642
 643       n = read (fd, buf, sizeof buf);
 644       if (__builtin_expect (n, 1) > 0)
 645         {
 646           char *mhz = memmem (buf, n, "cpu MHz", 7);
 647
 648           if (__glibc_likely (mhz != NULL))
 649             {
 650               char *endp = buf + n;
 651               int seen_decpoint = 0;
 652               int ndigits = 0;
 653
 654               /* Search for the beginning of the string.  */
 655               while (mhz < endp && (*mhz < '0' || *mhz > '9') && *mhz != '\n')
 656                 ++mhz;
 657
 658               while (mhz < endp && *mhz != '\n')
 659                 {
 660                   if (*mhz >= '0' && *mhz <= '9')
 661                     {
 662                       result *= 10;
 663                       result += *mhz - '0';
 664                       if (seen_decpoint)
 665                         ++ndigits;
 666                     }
 667                   else if (*mhz == '.')
 668                     seen_decpoint = 1;
 669
 670                   ++mhz;
 671                 }
 672
 673               /* Compensate for missing digits at the end.  */
 674               while (ndigits++ < 6)
 675                 result *= 10;
 676             }
 677         }
 678
 679       close (fd);
 680     }
 681
 682   return result;
 683 }
 684
 685
 686 int
 687 clock_getcpuclockid (pid_t pid, clockid_t *clock_id)
 688 {
 689   /* We don't allow any process ID but our own.  */
 690   if (pid != 0 && pid != getpid ())
 691     return EPERM;
 692
 693 #ifdef CLOCK_PROCESS_CPUTIME_ID
 694   /* Store the number.  */
 695   *clock_id = CLOCK_PROCESS_CPUTIME_ID;
 696
 697   return 0;
 698 #else
 699   /* We don't have a timer for that.  */
 700   return ENOENT;
 701 #endif
 702 }
 703
 704
 705 #ifdef i386
 706 #define HP_TIMING_NOW(Var)      __asm__ __volatile__ ("rdtsc" : "=A" (Var))
 707 #elif defined __x86_64__
 708 # define HP_TIMING_NOW(Var) \
 709   ({ unsigned int _hi, _lo; \
 710      asm volatile ("rdtsc" : "=a" (_lo), "=d" (_hi)); \
 711      (Var) = ((unsigned long long int) _hi << 32) | _lo; })
 712 #elif defined __ia64__
 713 #define HP_TIMING_NOW(Var)      __asm__ __volatile__ ("mov %0=ar.itc" : "=r" (Var) : : "memory")
 714 #else
 715 #error "HP_TIMING_NOW missing"
 716 #endif
 717
 718 /* Get current value of CLOCK and store it in TP.  */
 719 int
 720 clock_gettime (clockid_t clock_id, struct timespec *tp)
 721 {
 722   int retval = -1;
 723
 724   switch (clock_id)
 725     {
 726     case CLOCK_PROCESS_CPUTIME_ID:
 727       {
 728
 729         static hp_timing_t freq;
 730         hp_timing_t tsc;
 731
 732         /* Get the current counter.  */
 733         HP_TIMING_NOW (tsc);
 734
 735         if (freq == 0)
 736           {
 737             freq = get_clockfreq ();
 738             if (freq == 0)
 739               return EINVAL;
 740           }
 741
 742         /* Compute the seconds.  */
 743         tp->tv_sec = tsc / freq;
 744
 745         /* And the nanoseconds.  This computation should be stable until
 746            we get machines with about 16GHz frequency.  */
 747         tp->tv_nsec = ((tsc % freq) * UINT64_C (1000000000)) / freq;
 748
 749         retval = 0;
 750       }
 751     break;
 752
 753     default:
 754       errno = EINVAL;
 755       break;
 756     }
 757
 758   return retval;
 759 }