tests/benchmark/test_urcu_wfcq.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 concurrent queue
   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/wfcqueue.h>
  35
  36 enum test_sync {
  37         TEST_SYNC_NONE = 0,
  38         TEST_SYNC_MUTEX,
  39 };
  40
  41 static enum test_sync test_sync;
  42
  43 static int test_force_sync;
  44
  45 static volatile int test_stop_enqueue, test_stop_dequeue;
  46
  47 static unsigned long rduration;
  48
  49 static unsigned long duration;
  50
  51 /* read-side C.S. duration, in loops */
  52 static unsigned long wdelay;
  53
  54 static inline void loop_sleep(unsigned long loops)
  55 {
  56         while (loops-- != 0)
  57                 caa_cpu_relax();
  58 }
  59
  60 static int verbose_mode;
  61
  62 static int test_dequeue, test_splice, test_wait_empty;
  63 static unsigned int test_enqueue_stopped;
  64
  65 #define printf_verbose(fmt, args...)            \
  66         do {                                    \
  67                 if (verbose_mode)               \
  68                         printf(fmt, ## args);   \
  69         } while (0)
  70
  71 static unsigned int cpu_affinities[NR_CPUS];
  72 static unsigned int next_aff = 0;
  73 static int use_affinity = 0;
  74
  75 pthread_mutex_t affinity_mutex = PTHREAD_MUTEX_INITIALIZER;
  76
  77 static void set_affinity(void)
  78 {
  79 #ifdef HAVE_SCHED_SETAFFINITY
  80         cpu_set_t mask;
  81         int cpu, ret;
  82 #endif /* HAVE_SCHED_SETAFFINITY */
  83
  84         if (!use_affinity)
  85                 return;
  86
  87 #ifdef HAVE_SCHED_SETAFFINITY
  88         ret = pthread_mutex_lock(&affinity_mutex);
  89         if (ret) {
  90                 perror("Error in pthread mutex lock");
  91                 exit(-1);
  92         }
  93         cpu = cpu_affinities[next_aff++];
  94         ret = pthread_mutex_unlock(&affinity_mutex);
  95         if (ret) {
  96                 perror("Error in pthread mutex unlock");
  97                 exit(-1);
  98         }
  99
 100         CPU_ZERO(&mask);
 101         CPU_SET(cpu, &mask);
 102         sched_setaffinity(0, sizeof(mask), &mask);
 103 #endif /* HAVE_SCHED_SETAFFINITY */
 104 }
 105
 106 /*
 107  * returns 0 if test should end.
 108  */
 109 static int test_duration_dequeue(void)
 110 {
 111         return !uatomic_load(&test_stop_dequeue, CMM_RELAXED);
 112 }
 113
 114 static int test_duration_enqueue(void)
 115 {
 116         return !uatomic_load(&test_stop_enqueue, CMM_RELAXED);
 117 }
 118
 119 static DEFINE_URCU_TLS(unsigned long long, nr_dequeues);
 120 static DEFINE_URCU_TLS(unsigned long long, nr_enqueues);
 121
 122 static DEFINE_URCU_TLS(unsigned long long, nr_successful_dequeues);
 123 static DEFINE_URCU_TLS(unsigned long long, nr_successful_enqueues);
 124 static DEFINE_URCU_TLS(unsigned long long, nr_empty_dest_enqueues);
 125 static DEFINE_URCU_TLS(unsigned long long, nr_splice);
 126 static DEFINE_URCU_TLS(unsigned long long, nr_dequeue_last);
 127
 128 static unsigned int nr_enqueuers;
 129 static unsigned int nr_dequeuers;
 130
 131 static struct cds_wfcq_head __attribute__((aligned(CAA_CACHE_LINE_SIZE))) head;
 132 static struct cds_wfcq_tail __attribute__((aligned(CAA_CACHE_LINE_SIZE))) tail;
 133
 134 static void *thr_enqueuer(void *_count)
 135 {
 136         unsigned long long *count = _count;
 137         bool was_nonempty;
 138
 139         printf_verbose("thread_begin %s, tid %lu\n",
 140                         "enqueuer", urcu_get_thread_id());
 141
 142         set_affinity();
 143
 144         wait_until_go();
 145
 146         for (;;) {
 147                 struct cds_wfcq_node *node = malloc(sizeof(*node));
 148                 if (!node)
 149                         goto fail;
 150                 cds_wfcq_node_init(node);
 151                 was_nonempty = cds_wfcq_enqueue(&head, &tail, node);
 152                 URCU_TLS(nr_successful_enqueues)++;
 153                 if (!was_nonempty)
 154                         URCU_TLS(nr_empty_dest_enqueues)++;
 155
 156                 if (caa_unlikely(wdelay))
 157                         loop_sleep(wdelay);
 158 fail:
 159                 URCU_TLS(nr_enqueues)++;
 160                 if (caa_unlikely(!test_duration_enqueue()))
 161                         break;
 162         }
 163
 164         uatomic_inc(&test_enqueue_stopped);
 165         count[0] = URCU_TLS(nr_enqueues);
 166         count[1] = URCU_TLS(nr_successful_enqueues);
 167         count[2] = URCU_TLS(nr_empty_dest_enqueues);
 168         printf_verbose("enqueuer thread_end, tid %lu, "
 169                         "enqueues %llu successful_enqueues %llu, "
 170                         "empty_dest_enqueues %llu\n",
 171                         urcu_get_thread_id(),
 172                         URCU_TLS(nr_enqueues),
 173                         URCU_TLS(nr_successful_enqueues),
 174                         URCU_TLS(nr_empty_dest_enqueues));
 175         return ((void*)1);
 176
 177 }
 178
 179 static void do_test_dequeue(enum test_sync sync)
 180 {
 181         struct cds_wfcq_node *node;
 182         int state;
 183
 184         if (sync == TEST_SYNC_MUTEX)
 185                 node = cds_wfcq_dequeue_with_state_blocking(&head, &tail,
 186                                 &state);
 187         else
 188                 node = __cds_wfcq_dequeue_with_state_blocking(&head, &tail,
 189                                 &state);
 190
 191         if (state & CDS_WFCQ_STATE_LAST)
 192                 URCU_TLS(nr_dequeue_last)++;
 193
 194         if (node) {
 195                 free(node);
 196                 URCU_TLS(nr_successful_dequeues)++;
 197         }
 198         URCU_TLS(nr_dequeues)++;
 199 }
 200
 201 static void do_test_splice(enum test_sync sync)
 202 {
 203         struct cds_wfcq_head tmp_head;
 204         struct cds_wfcq_tail tmp_tail;
 205         struct cds_wfcq_node *node, *n;
 206         enum cds_wfcq_ret ret;
 207
 208         cds_wfcq_init(&tmp_head, &tmp_tail);
 209
 210         if (sync == TEST_SYNC_MUTEX)
 211                 ret = cds_wfcq_splice_blocking(&tmp_head, &tmp_tail,
 212                         &head, &tail);
 213         else
 214                 ret = __cds_wfcq_splice_blocking(&tmp_head, &tmp_tail,
 215                         &head, &tail);
 216
 217         switch (ret) {
 218         case CDS_WFCQ_RET_WOULDBLOCK:
 219                 urcu_posix_assert(0);   /* blocking call */
 220                 break;
 221         case CDS_WFCQ_RET_DEST_EMPTY:
 222                 URCU_TLS(nr_splice)++;
 223                 URCU_TLS(nr_dequeue_last)++;
 224                 /* ok */
 225                 break;
 226         case CDS_WFCQ_RET_DEST_NON_EMPTY:
 227                 urcu_posix_assert(0);   /* entirely unexpected */
 228                 break;
 229         case CDS_WFCQ_RET_SRC_EMPTY:
 230                 /* ok, we could even skip iteration on dest if we wanted */
 231                 break;
 232         }
 233
 234         __cds_wfcq_for_each_blocking_safe(&tmp_head, &tmp_tail, node, n) {
 235                 free(node);
 236                 URCU_TLS(nr_successful_dequeues)++;
 237                 URCU_TLS(nr_dequeues)++;
 238         }
 239         cds_wfcq_destroy(&tmp_head, &tmp_tail);
 240 }
 241
 242 static void *thr_dequeuer(void *_count)
 243 {
 244         unsigned long long *count = _count;
 245         unsigned int counter = 0;
 246
 247         printf_verbose("thread_begin %s, tid %lu\n",
 248                         "dequeuer", urcu_get_thread_id());
 249
 250         set_affinity();
 251
 252         wait_until_go();
 253
 254         for (;;) {
 255                 if (test_dequeue && test_splice) {
 256                         if (counter & 1)
 257                                 do_test_dequeue(test_sync);
 258                         else
 259                                 do_test_splice(test_sync);
 260                         counter++;
 261                 } else {
 262                         if (test_dequeue)
 263                                 do_test_dequeue(test_sync);
 264                         else
 265                                 do_test_splice(test_sync);
 266                 }
 267                 if (caa_unlikely(!test_duration_dequeue()))
 268                         break;
 269                 if (caa_unlikely(rduration))
 270                         loop_sleep(rduration);
 271         }
 272
 273         printf_verbose("dequeuer thread_end, tid %lu, "
 274                         "dequeues %llu, successful_dequeues %llu, "
 275                         "nr_splice %llu\n",
 276                         urcu_get_thread_id(),
 277                         URCU_TLS(nr_dequeues), URCU_TLS(nr_successful_dequeues),
 278                         URCU_TLS(nr_splice));
 279         count[0] = URCU_TLS(nr_dequeues);
 280         count[1] = URCU_TLS(nr_successful_dequeues);
 281         count[2] = URCU_TLS(nr_splice);
 282         count[3] = URCU_TLS(nr_dequeue_last);
 283         return ((void*)2);
 284 }
 285
 286 static void test_end(unsigned long long *nr_dequeues_l,
 287                 unsigned long long *nr_dequeue_last_l)
 288 {
 289         struct cds_wfcq_node *node;
 290         int state;
 291
 292         do {
 293                 node = cds_wfcq_dequeue_with_state_blocking(&head, &tail,
 294                                 &state);
 295                 if (node) {
 296                         if (state & CDS_WFCQ_STATE_LAST)
 297                                 (*nr_dequeue_last_l)++;
 298                         free(node);
 299                         (*nr_dequeues_l)++;
 300                 }
 301         } while (node);
 302 }
 303
 304 static void show_usage(char **argv)
 305 {
 306         printf("Usage : %s nr_dequeuers nr_enqueuers duration (s) <OPTIONS>\n",
 307                 argv[0]);
 308         printf("OPTIONS:\n");
 309         printf("        [-d delay] (enqueuer period (in loops))\n");
 310         printf("        [-c duration] (dequeuer period (in loops))\n");
 311         printf("        [-v] (verbose output)\n");
 312         printf("        [-a cpu#] [-a cpu#]... (affinity)\n");
 313         printf("        [-q] (test dequeue)\n");
 314         printf("        [-s] (test splice, enabled by default)\n");
 315         printf("        [-M] (use mutex external synchronization)\n");
 316         printf("                Note: default: no external synchronization used.\n");
 317         printf("        [-f] (force user-provided synchronization)\n");
 318         printf("        [-w] Wait for dequeuer to empty queue\n");
 319         printf("\n");
 320 }
 321
 322 int main(int argc, char **argv)
 323 {
 324         int err;
 325         pthread_t *tid_enqueuer, *tid_dequeuer;
 326         void *tret;
 327         unsigned long long *count_enqueuer, *count_dequeuer;
 328         unsigned long long tot_enqueues = 0, tot_dequeues = 0;
 329         unsigned long long tot_successful_enqueues = 0,
 330                            tot_successful_dequeues = 0,
 331                            tot_empty_dest_enqueues = 0,
 332                            tot_splice = 0, tot_dequeue_last = 0;
 333         unsigned long long end_dequeues = 0;
 334         int i, a, retval = 0;
 335         unsigned int i_thr;
 336
 337         if (argc < 4) {
 338                 show_usage(argv);
 339                 return -1;
 340         }
 341
 342         err = sscanf(argv[1], "%u", &nr_dequeuers);
 343         if (err != 1) {
 344                 show_usage(argv);
 345                 return -1;
 346         }
 347
 348         err = sscanf(argv[2], "%u", &nr_enqueuers);
 349         if (err != 1) {
 350                 show_usage(argv);
 351                 return -1;
 352         }
 353
 354         err = sscanf(argv[3], "%lu", &duration);
 355         if (err != 1) {
 356                 show_usage(argv);
 357                 return -1;
 358         }
 359
 360         for (i = 4; i < argc; i++) {
 361                 if (argv[i][0] != '-')
 362                         continue;
 363                 switch (argv[i][1]) {
 364                 case 'a':
 365                         if (argc < i + 2) {
 366                                 show_usage(argv);
 367                                 return -1;
 368                         }
 369                         a = atoi(argv[++i]);
 370                         cpu_affinities[next_aff++] = a;
 371                         use_affinity = 1;
 372                         printf_verbose("Adding CPU %d affinity\n", a);
 373                         break;
 374                 case 'c':
 375                         if (argc < i + 2) {
 376                                 show_usage(argv);
 377                                 return -1;
 378                         }
 379                         rduration = atol(argv[++i]);
 380                         break;
 381                 case 'd':
 382                         if (argc < i + 2) {
 383                                 show_usage(argv);
 384                                 return -1;
 385                         }
 386                         wdelay = atol(argv[++i]);
 387                         break;
 388                 case 'v':
 389                         verbose_mode = 1;
 390                         break;
 391                 case 'q':
 392                         test_dequeue = 1;
 393                         break;
 394                 case 's':
 395                         test_splice = 1;
 396                         break;
 397                 case 'M':
 398                         test_sync = TEST_SYNC_MUTEX;
 399                         break;
 400                 case 'w':
 401                         test_wait_empty = 1;
 402                         break;
 403                 case 'f':
 404                         test_force_sync = 1;
 405                         break;
 406                 }
 407         }
 408
 409         /* activate splice test by default */
 410         if (!test_dequeue && !test_splice)
 411                 test_splice = 1;
 412
 413         if (test_sync == TEST_SYNC_NONE && nr_dequeuers > 1 && test_dequeue) {
 414                 if (test_force_sync) {
 415                         fprintf(stderr, "[WARNING] Using dequeue concurrently "
 416                                 "with other dequeue or splice without external "
 417                                 "synchronization. Expect run-time failure.\n");
 418                 } else {
 419                         printf("Enforcing mutex synchronization\n");
 420                         test_sync = TEST_SYNC_MUTEX;
 421                 }
 422         }
 423
 424         printf_verbose("running test for %lu seconds, %u enqueuers, "
 425                        "%u dequeuers.\n",
 426                        duration, nr_enqueuers, nr_dequeuers);
 427         if (test_dequeue)
 428                 printf_verbose("dequeue test activated.\n");
 429         else
 430                 printf_verbose("splice test activated.\n");
 431         if (test_sync == TEST_SYNC_MUTEX)
 432                 printf_verbose("External sync: mutex.\n");
 433         else
 434                 printf_verbose("External sync: none.\n");
 435         if (test_wait_empty)
 436                 printf_verbose("Wait for dequeuers to empty queue.\n");
 437         printf_verbose("Writer delay : %lu loops.\n", rduration);
 438         printf_verbose("Reader duration : %lu loops.\n", wdelay);
 439         printf_verbose("thread %-6s, tid %lu\n",
 440                         "main", urcu_get_thread_id());
 441
 442         tid_enqueuer = calloc(nr_enqueuers, sizeof(*tid_enqueuer));
 443         tid_dequeuer = calloc(nr_dequeuers, sizeof(*tid_dequeuer));
 444         count_enqueuer = calloc(nr_enqueuers, 3 * sizeof(*count_enqueuer));
 445         count_dequeuer = calloc(nr_dequeuers, 4 * sizeof(*count_dequeuer));
 446         cds_wfcq_init(&head, &tail);
 447
 448         next_aff = 0;
 449
 450         for (i_thr = 0; i_thr < nr_enqueuers; i_thr++) {
 451                 err = pthread_create(&tid_enqueuer[i_thr], NULL, thr_enqueuer,
 452                                      &count_enqueuer[3 * i_thr]);
 453                 if (err != 0)
 454                         exit(1);
 455         }
 456         for (i_thr = 0; i_thr < nr_dequeuers; i_thr++) {
 457                 err = pthread_create(&tid_dequeuer[i_thr], NULL, thr_dequeuer,
 458                                      &count_dequeuer[4 * i_thr]);
 459                 if (err != 0)
 460                         exit(1);
 461         }
 462
 463         cmm_smp_mb();
 464
 465         begin_test();
 466
 467         for (i_thr = 0; i_thr < duration; i_thr++) {
 468                 sleep(1);
 469                 if (verbose_mode) {
 470                         fwrite(".", sizeof(char), 1, stdout);
 471                         fflush(stdout);
 472                 }
 473         }
 474
 475         uatomic_store(&test_stop_enqueue, 1, CMM_RELEASE);
 476
 477         if (test_wait_empty) {
 478                 while (nr_enqueuers != uatomic_read(&test_enqueue_stopped)) {
 479                         sleep(1);
 480                 }
 481                 while (!cds_wfcq_empty(&head, &tail)) {
 482                         sleep(1);
 483                 }
 484         }
 485
 486         uatomic_store(&test_stop_dequeue, 1, CMM_RELAXED);
 487
 488         for (i_thr = 0; i_thr < nr_enqueuers; i_thr++) {
 489                 err = pthread_join(tid_enqueuer[i_thr], &tret);
 490                 if (err != 0)
 491                         exit(1);
 492                 tot_enqueues += count_enqueuer[3 * i_thr];
 493                 tot_successful_enqueues += count_enqueuer[3 * i_thr + 1];
 494                 tot_empty_dest_enqueues += count_enqueuer[3 * i_thr + 2];
 495         }
 496         for (i_thr = 0; i_thr < nr_dequeuers; i_thr++) {
 497                 err = pthread_join(tid_dequeuer[i_thr], &tret);
 498                 if (err != 0)
 499                         exit(1);
 500                 tot_dequeues += count_dequeuer[4 * i_thr];
 501                 tot_successful_dequeues += count_dequeuer[4 * i_thr + 1];
 502                 tot_splice += count_dequeuer[4 * i_thr + 2];
 503                 tot_dequeue_last += count_dequeuer[4 * i_thr + 3];
 504         }
 505
 506         test_end(&end_dequeues, &tot_dequeue_last);
 507
 508         printf_verbose("total number of enqueues : %llu, dequeues %llu\n",
 509                        tot_enqueues, tot_dequeues);
 510         printf_verbose("total number of successful enqueues : %llu, "
 511                        "enqueues to empty dest : %llu, "
 512                        "successful dequeues %llu, "
 513                        "splice : %llu, dequeue_last : %llu\n",
 514                        tot_successful_enqueues,
 515                        tot_empty_dest_enqueues,
 516                        tot_successful_dequeues,
 517                        tot_splice, tot_dequeue_last);
 518         printf("SUMMARY %-25s testdur %4lu nr_enqueuers %3u wdelay %6lu "
 519                 "nr_dequeuers %3u "
 520                 "rdur %6lu nr_enqueues %12llu nr_dequeues %12llu "
 521                 "successful enqueues %12llu enqueues to empty dest %12llu "
 522                 "successful dequeues %12llu splice %12llu "
 523                 "dequeue_last %llu "
 524                 "end_dequeues %llu nr_ops %12llu\n",
 525                 argv[0], duration, nr_enqueuers, wdelay,
 526                 nr_dequeuers, rduration, tot_enqueues, tot_dequeues,
 527                 tot_successful_enqueues,
 528                 tot_empty_dest_enqueues,
 529                 tot_successful_dequeues, tot_splice, tot_dequeue_last,
 530                 end_dequeues,
 531                 tot_enqueues + tot_dequeues);
 532
 533         if (tot_successful_enqueues != tot_successful_dequeues + end_dequeues) {
 534                 printf("WARNING! Discrepancy between nr succ. enqueues %llu vs "
 535                        "succ. dequeues + end dequeues %llu.\n",
 536                        tot_successful_enqueues,
 537                        tot_successful_dequeues + end_dequeues);
 538                 retval = 1;
 539         }
 540
 541         /*
 542          * If only using splice to dequeue, the enqueuer should see
 543          * exactly as many empty queues than the number of non-empty
 544          * src splice.
 545          */
 546         if (tot_empty_dest_enqueues != tot_dequeue_last) {
 547                 printf("WARNING! Discrepancy between empty enqueue (%llu) and "
 548                         "number of dequeue of last element (%llu)\n",
 549                         tot_empty_dest_enqueues,
 550                         tot_dequeue_last);
 551                 retval = 1;
 552         }
 553         cds_wfcq_destroy(&head, &tail);
 554         free(count_enqueuer);
 555         free(count_dequeuer);
 556         free(tid_enqueuer);
 557         free(tid_dequeuer);
 558
 559         return retval;
 560 }