tests/benchmark/test_urcu_wfs.c

   1 // SPDX-FileCopyrightText: 2010 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   2 // SPDX-FileCopyrightText: 2010 Paolo Bonzini <pbonzini@redhat.com>
   3 //
   4 // SPDX-License-Identifier: GPL-2.0-or-later
   5
   6  /*
   7  * Userspace RCU library - example RCU-based lock-free stack
   8  */
   9
  10 #include <stdio.h>
  11 #include <pthread.h>
  12 #include <stdlib.h>
  13 #include <stdint.h>
  14 #include <stdbool.h>
  15 #include <string.h>
  16 #include <sys/types.h>
  17 #include <sys/wait.h>
  18 #include <unistd.h>
  19 #include <stdio.h>
  20 #include <errno.h>
  21
  22 #include <urcu/arch.h>
  23 #include <urcu/assert.h>
  24 #include <urcu/tls-compat.h>
  25 #include <urcu/uatomic.h>
  26 #include "thread-id.h"
  27
  28 /* hardcoded number of CPUs */
  29 #define NR_CPUS 16384
  30
  31 #ifndef DYNAMIC_LINK_TEST
  32 #define _LGPL_SOURCE
  33 #endif
  34 #include <urcu/wfstack.h>
  35
  36 /*
  37  * External synchronization used.
  38  */
  39 enum test_sync {
  40         TEST_SYNC_NONE = 0,
  41         TEST_SYNC_MUTEX,
  42 };
  43
  44 static enum test_sync test_sync;
  45
  46 static int test_force_sync;
  47
  48 static volatile int test_stop_enqueue, test_stop_dequeue;
  49
  50 static unsigned long rduration;
  51
  52 static unsigned long duration;
  53
  54 /* read-side C.S. duration, in loops */
  55 static unsigned long wdelay;
  56
  57 static inline void loop_sleep(unsigned long loops)
  58 {
  59         while (loops-- != 0)
  60                 caa_cpu_relax();
  61 }
  62
  63 static int verbose_mode;
  64
  65 static int test_pop, test_pop_all, test_wait_empty;
  66 static unsigned int test_enqueue_stopped;
  67
  68 #define printf_verbose(fmt, args...)            \
  69         do {                                    \
  70                 if (verbose_mode)               \
  71                         printf(fmt, ## args);   \
  72         } while (0)
  73
  74 static unsigned int cpu_affinities[NR_CPUS];
  75 static unsigned int next_aff = 0;
  76 static int use_affinity = 0;
  77
  78 pthread_mutex_t affinity_mutex = PTHREAD_MUTEX_INITIALIZER;
  79
  80 static void set_affinity(void)
  81 {
  82 #ifdef HAVE_SCHED_SETAFFINITY
  83         cpu_set_t mask;
  84         int cpu, ret;
  85 #endif /* HAVE_SCHED_SETAFFINITY */
  86
  87         if (!use_affinity)
  88                 return;
  89
  90 #ifdef HAVE_SCHED_SETAFFINITY
  91         ret = pthread_mutex_lock(&affinity_mutex);
  92         if (ret) {
  93                 perror("Error in pthread mutex lock");
  94                 exit(-1);
  95         }
  96         cpu = cpu_affinities[next_aff++];
  97         ret = pthread_mutex_unlock(&affinity_mutex);
  98         if (ret) {
  99                 perror("Error in pthread mutex unlock");
 100                 exit(-1);
 101         }
 102
 103         CPU_ZERO(&mask);
 104         CPU_SET(cpu, &mask);
 105         sched_setaffinity(0, sizeof(mask), &mask);
 106 #endif /* HAVE_SCHED_SETAFFINITY */
 107 }
 108
 109 /*
 110  * returns 0 if test should end.
 111  */
 112 static int test_duration_dequeue(void)
 113 {
 114         return !uatomic_load(&test_stop_dequeue, CMM_RELAXED);
 115 }
 116
 117 static int test_duration_enqueue(void)
 118 {
 119         return !uatomic_load(&test_stop_enqueue, CMM_RELAXED);
 120 }
 121
 122 static DEFINE_URCU_TLS(unsigned long long, nr_dequeues);
 123 static DEFINE_URCU_TLS(unsigned long long, nr_enqueues);
 124
 125 static DEFINE_URCU_TLS(unsigned long long, nr_successful_dequeues);
 126 static DEFINE_URCU_TLS(unsigned long long, nr_successful_enqueues);
 127 static DEFINE_URCU_TLS(unsigned long long, nr_empty_dest_enqueues);
 128 static DEFINE_URCU_TLS(unsigned long long, nr_pop_all);
 129 static DEFINE_URCU_TLS(unsigned long long, nr_pop_last);
 130
 131 static unsigned int nr_enqueuers;
 132 static unsigned int nr_dequeuers;
 133
 134 static struct cds_wfs_stack s;
 135
 136 static void *thr_enqueuer(void *_count)
 137 {
 138         unsigned long long *count = _count;
 139         bool was_nonempty;
 140
 141         printf_verbose("thread_begin %s, tid %lu\n",
 142                         "enqueuer", urcu_get_thread_id());
 143
 144         set_affinity();
 145
 146         wait_until_go();
 147
 148         for (;;) {
 149                 struct cds_wfs_node *node = malloc(sizeof(*node));
 150                 if (!node)
 151                         goto fail;
 152                 cds_wfs_node_init(node);
 153                 was_nonempty = cds_wfs_push(&s, node);
 154                 URCU_TLS(nr_successful_enqueues)++;
 155                 if (!was_nonempty)
 156                         URCU_TLS(nr_empty_dest_enqueues)++;
 157
 158                 if (caa_unlikely(wdelay))
 159                         loop_sleep(wdelay);
 160 fail:
 161                 URCU_TLS(nr_enqueues)++;
 162                 if (caa_unlikely(!test_duration_enqueue()))
 163                         break;
 164         }
 165
 166         uatomic_inc(&test_enqueue_stopped);
 167         count[0] = URCU_TLS(nr_enqueues);
 168         count[1] = URCU_TLS(nr_successful_enqueues);
 169         count[2] = URCU_TLS(nr_empty_dest_enqueues);
 170         printf_verbose("enqueuer thread_end, tid %lu, "
 171                         "enqueues %llu successful_enqueues %llu, "
 172                         "empty_dest_enqueues %llu\n",
 173                         urcu_get_thread_id(),
 174                         URCU_TLS(nr_enqueues),
 175                         URCU_TLS(nr_successful_enqueues),
 176                         URCU_TLS(nr_empty_dest_enqueues));
 177         return ((void*)1);
 178
 179 }
 180
 181 static void do_test_pop(enum test_sync sync)
 182 {
 183         struct cds_wfs_node *node;
 184         int state;
 185
 186         if (sync == TEST_SYNC_MUTEX)
 187                 cds_wfs_pop_lock(&s);
 188         node = __cds_wfs_pop_with_state_blocking(&s, &state);
 189         if (sync == TEST_SYNC_MUTEX)
 190                 cds_wfs_pop_unlock(&s);
 191
 192         if (node) {
 193                 if (state & CDS_WFS_STATE_LAST)
 194                         URCU_TLS(nr_pop_last)++;
 195                 free(node);
 196                 URCU_TLS(nr_successful_dequeues)++;
 197         }
 198         URCU_TLS(nr_dequeues)++;
 199 }
 200
 201 static void do_test_pop_all(enum test_sync sync)
 202 {
 203         struct cds_wfs_head *head;
 204         struct cds_wfs_node *node, *n;
 205
 206         if (sync == TEST_SYNC_MUTEX)
 207                 cds_wfs_pop_lock(&s);
 208         head = __cds_wfs_pop_all(&s);
 209         if (sync == TEST_SYNC_MUTEX)
 210                 cds_wfs_pop_unlock(&s);
 211
 212         /* Check if empty */
 213         if (cds_wfs_first(head) == NULL)
 214                 return;
 215
 216         URCU_TLS(nr_pop_all)++;
 217         URCU_TLS(nr_pop_last)++;
 218
 219         cds_wfs_for_each_blocking_safe(head, node, n) {
 220                 free(node);
 221                 URCU_TLS(nr_successful_dequeues)++;
 222                 URCU_TLS(nr_dequeues)++;
 223         }
 224 }
 225
 226 static void *thr_dequeuer(void *_count)
 227 {
 228         unsigned long long *count = _count;
 229         unsigned int counter = 0;
 230
 231         printf_verbose("thread_begin %s, tid %lu\n",
 232                         "dequeuer", urcu_get_thread_id());
 233
 234         set_affinity();
 235
 236         wait_until_go();
 237
 238         urcu_posix_assert(test_pop || test_pop_all);
 239
 240         for (;;) {
 241                 if (test_pop && test_pop_all) {
 242                         if (counter & 1)
 243                                 do_test_pop(test_sync);
 244                         else
 245                                 do_test_pop_all(test_sync);
 246                         counter++;
 247                 } else {
 248                         if (test_pop)
 249                                 do_test_pop(test_sync);
 250                         else
 251                                 do_test_pop_all(test_sync);
 252                 }
 253
 254                 if (caa_unlikely(!test_duration_dequeue()))
 255                         break;
 256                 if (caa_unlikely(rduration))
 257                         loop_sleep(rduration);
 258         }
 259
 260         printf_verbose("dequeuer thread_end, tid %lu, "
 261                         "dequeues %llu, successful_dequeues %llu "
 262                         "pop_all %llu pop_last %llu\n",
 263                         urcu_get_thread_id(),
 264                         URCU_TLS(nr_dequeues), URCU_TLS(nr_successful_dequeues),
 265                         URCU_TLS(nr_pop_all),
 266                         URCU_TLS(nr_pop_last));
 267         count[0] = URCU_TLS(nr_dequeues);
 268         count[1] = URCU_TLS(nr_successful_dequeues);
 269         count[2] = URCU_TLS(nr_pop_all);
 270         count[3] = URCU_TLS(nr_pop_last);
 271         return ((void*)2);
 272 }
 273
 274 static void test_end(unsigned long long *nr_dequeues_l,
 275                 unsigned long long *nr_pop_last_l)
 276 {
 277         struct cds_wfs_node *node;
 278         int state;
 279
 280         do {
 281                 node = cds_wfs_pop_with_state_blocking(&s, &state);
 282                 if (node) {
 283                         if (state & CDS_WFS_STATE_LAST)
 284                                 (*nr_pop_last_l)++;
 285                         free(node);
 286                         (*nr_dequeues_l)++;
 287                 }
 288         } while (node);
 289 }
 290
 291 static void show_usage(char **argv)
 292 {
 293         printf("Usage : %s nr_dequeuers nr_enqueuers duration (s) <OPTIONS>\n",
 294                 argv[0]);
 295         printf("OPTIONS:\n");
 296         printf("        [-d delay] (enqueuer period (in loops))\n");
 297         printf("        [-c duration] (dequeuer period (in loops))\n");
 298         printf("        [-v] (verbose output)\n");
 299         printf("        [-a cpu#] [-a cpu#]... (affinity)\n");
 300         printf("        [-p] (test pop)\n");
 301         printf("        [-P] (test pop_all, enabled by default)\n");
 302         printf("        [-M] (use mutex external synchronization)\n");
 303         printf("                Note: default: no external synchronization used.\n");
 304         printf("        [-f] (force user-provided synchronization)\n");
 305         printf("        [-w] Wait for dequeuer to empty stack\n");
 306         printf("\n");
 307 }
 308
 309 int main(int argc, char **argv)
 310 {
 311         int err;
 312         pthread_t *tid_enqueuer, *tid_dequeuer;
 313         void *tret;
 314         unsigned long long *count_enqueuer, *count_dequeuer;
 315         unsigned long long tot_enqueues = 0, tot_dequeues = 0;
 316         unsigned long long tot_successful_enqueues = 0,
 317                            tot_successful_dequeues = 0,
 318                            tot_empty_dest_enqueues = 0,
 319                            tot_pop_all = 0, tot_pop_last = 0;
 320         unsigned long long end_dequeues = 0;
 321         int i, a, retval = 0;
 322         unsigned int i_thr;
 323
 324         if (argc < 4) {
 325                 show_usage(argv);
 326                 return -1;
 327         }
 328
 329         err = sscanf(argv[1], "%u", &nr_dequeuers);
 330         if (err != 1) {
 331                 show_usage(argv);
 332                 return -1;
 333         }
 334
 335         err = sscanf(argv[2], "%u", &nr_enqueuers);
 336         if (err != 1) {
 337                 show_usage(argv);
 338                 return -1;
 339         }
 340
 341         err = sscanf(argv[3], "%lu", &duration);
 342         if (err != 1) {
 343                 show_usage(argv);
 344                 return -1;
 345         }
 346
 347         for (i = 4; i < argc; i++) {
 348                 if (argv[i][0] != '-')
 349                         continue;
 350                 switch (argv[i][1]) {
 351                 case 'a':
 352                         if (argc < i + 2) {
 353                                 show_usage(argv);
 354                                 return -1;
 355                         }
 356                         a = atoi(argv[++i]);
 357                         cpu_affinities[next_aff++] = a;
 358                         use_affinity = 1;
 359                         printf_verbose("Adding CPU %d affinity\n", a);
 360                         break;
 361                 case 'c':
 362                         if (argc < i + 2) {
 363                                 show_usage(argv);
 364                                 return -1;
 365                         }
 366                         rduration = atol(argv[++i]);
 367                         break;
 368                 case 'd':
 369                         if (argc < i + 2) {
 370                                 show_usage(argv);
 371                                 return -1;
 372                         }
 373                         wdelay = atol(argv[++i]);
 374                         break;
 375                 case 'v':
 376                         verbose_mode = 1;
 377                         break;
 378                 case 'p':
 379                         test_pop = 1;
 380                         break;
 381                 case 'P':
 382                         test_pop_all = 1;
 383                         break;
 384                 case 'M':
 385                         test_sync = TEST_SYNC_MUTEX;
 386                         break;
 387                 case 'w':
 388                         test_wait_empty = 1;
 389                         break;
 390                 case 'f':
 391                         test_force_sync = 1;
 392                         break;
 393                 }
 394         }
 395
 396         /* activate pop_all test by default */
 397         if (!test_pop && !test_pop_all)
 398                 test_pop_all = 1;
 399
 400         if (test_sync == TEST_SYNC_NONE && nr_dequeuers > 1 && test_pop) {
 401                 if (test_force_sync) {
 402                         fprintf(stderr, "[WARNING] Using pop concurrently "
 403                                 "with other pop or pop_all without external "
 404                                 "synchronization. Expect run-time failure.\n");
 405                 } else {
 406                         printf("Enforcing mutex synchronization\n");
 407                         test_sync = TEST_SYNC_MUTEX;
 408                 }
 409         }
 410
 411         printf_verbose("running test for %lu seconds, %u enqueuers, "
 412                        "%u dequeuers.\n",
 413                        duration, nr_enqueuers, nr_dequeuers);
 414         if (test_pop)
 415                 printf_verbose("pop test activated.\n");
 416         if (test_pop_all)
 417                 printf_verbose("pop_all test activated.\n");
 418         if (test_sync == TEST_SYNC_MUTEX)
 419                 printf_verbose("External sync: mutex.\n");
 420         else
 421                 printf_verbose("External sync: none.\n");
 422         if (test_wait_empty)
 423                 printf_verbose("Wait for dequeuers to empty stack.\n");
 424         printf_verbose("Writer delay : %lu loops.\n", rduration);
 425         printf_verbose("Reader duration : %lu loops.\n", wdelay);
 426         printf_verbose("thread %-6s, tid %lu\n",
 427                         "main", urcu_get_thread_id());
 428
 429         tid_enqueuer = calloc(nr_enqueuers, sizeof(*tid_enqueuer));
 430         tid_dequeuer = calloc(nr_dequeuers, sizeof(*tid_dequeuer));
 431         count_enqueuer = calloc(nr_enqueuers, 3 * sizeof(*count_enqueuer));
 432         count_dequeuer = calloc(nr_dequeuers, 4 * sizeof(*count_dequeuer));
 433         cds_wfs_init(&s);
 434
 435         next_aff = 0;
 436
 437         for (i_thr = 0; i_thr < nr_enqueuers; i_thr++) {
 438                 err = pthread_create(&tid_enqueuer[i], NULL, thr_enqueuer,
 439                                      &count_enqueuer[3 * i_thr]);
 440                 if (err != 0)
 441                         exit(1);
 442         }
 443         for (i_thr = 0; i_thr < nr_dequeuers; i_thr++) {
 444                 err = pthread_create(&tid_dequeuer[i_thr], NULL, thr_dequeuer,
 445                                      &count_dequeuer[4 * i_thr]);
 446                 if (err != 0)
 447                         exit(1);
 448         }
 449
 450         cmm_smp_mb();
 451
 452         begin_test();
 453
 454         for (i_thr = 0; i_thr < duration; i_thr++) {
 455                 sleep(1);
 456                 if (verbose_mode) {
 457                         fwrite(".", sizeof(char), 1, stdout);
 458                         fflush(stdout);
 459                 }
 460         }
 461
 462         uatomic_store(&test_stop_enqueue, 1, CMM_RELEASE);
 463
 464         if (test_wait_empty) {
 465                 while (nr_enqueuers != uatomic_read(&test_enqueue_stopped)) {
 466                         sleep(1);
 467                 }
 468                 while (!cds_wfs_empty(&s)) {
 469                         sleep(1);
 470                 }
 471         }
 472
 473         uatomic_store(&test_stop_dequeue, 1, CMM_RELAXED);
 474
 475         for (i_thr = 0; i_thr < nr_enqueuers; i_thr++) {
 476                 err = pthread_join(tid_enqueuer[i_thr], &tret);
 477                 if (err != 0)
 478                         exit(1);
 479                 tot_enqueues += count_enqueuer[3 * i_thr];
 480                 tot_successful_enqueues += count_enqueuer[3 * i_thr + 1];
 481                 tot_empty_dest_enqueues += count_enqueuer[3 * i_thr + 2];
 482         }
 483         for (i_thr = 0; i_thr < nr_dequeuers; i_thr++) {
 484                 err = pthread_join(tid_dequeuer[i_thr], &tret);
 485                 if (err != 0)
 486                         exit(1);
 487                 tot_dequeues += count_dequeuer[4 * i_thr];
 488                 tot_successful_dequeues += count_dequeuer[4 * i_thr + 1];
 489                 tot_pop_all += count_dequeuer[4 * i_thr + 2];
 490                 tot_pop_last += count_dequeuer[4 * i_thr + 3];
 491         }
 492
 493         test_end(&end_dequeues, &tot_pop_last);
 494
 495         printf_verbose("total number of enqueues : %llu, dequeues %llu\n",
 496                        tot_enqueues, tot_dequeues);
 497         printf_verbose("total number of successful enqueues : %llu, "
 498                        "enqueues to empty dest : %llu, "
 499                        "successful dequeues %llu, "
 500                        "pop_all : %llu, pop_last : %llu\n",
 501                        tot_successful_enqueues,
 502                        tot_empty_dest_enqueues,
 503                        tot_successful_dequeues,
 504                        tot_pop_all, tot_pop_last);
 505         printf("SUMMARY %-25s testdur %4lu nr_enqueuers %3u wdelay %6lu "
 506                 "nr_dequeuers %3u "
 507                 "rdur %6lu nr_enqueues %12llu nr_dequeues %12llu "
 508                 "successful enqueues %12llu enqueues to empty dest %12llu "
 509                 "successful dequeues %12llu pop_all %12llu "
 510                 "pop_last %llu end_dequeues %llu nr_ops %12llu\n",
 511                 argv[0], duration, nr_enqueuers, wdelay,
 512                 nr_dequeuers, rduration, tot_enqueues, tot_dequeues,
 513                 tot_successful_enqueues,
 514                 tot_empty_dest_enqueues,
 515                 tot_successful_dequeues, tot_pop_all, tot_pop_last,
 516                 end_dequeues,
 517                 tot_enqueues + tot_dequeues);
 518         if (tot_successful_enqueues != tot_successful_dequeues + end_dequeues) {
 519                 printf("WARNING! Discrepancy between nr succ. enqueues %llu vs "
 520                        "succ. dequeues + end dequeues %llu.\n",
 521                        tot_successful_enqueues,
 522                        tot_successful_dequeues + end_dequeues);
 523                 retval = 1;
 524         }
 525         /*
 526          * The enqueuer should see exactly as many empty queues than the
 527          * number of non-empty stacks dequeued.
 528          */
 529         if (tot_empty_dest_enqueues != tot_pop_last) {
 530                 printf("WARNING! Discrepancy between empty enqueue (%llu) and "
 531                         "number of pop last (%llu)\n",
 532                         tot_empty_dest_enqueues,
 533                         tot_pop_last);
 534                 retval = 1;
 535         }
 536
 537         cds_wfs_destroy(&s);
 538         free(count_enqueuer);
 539         free(count_dequeuer);
 540         free(tid_enqueuer);
 541         free(tid_dequeuer);
 542
 543         return retval;
 544 }