tests/test_urcu_gc.c

   1 /*
   2  * test_urcu_gc.c
   3  *
   4  * Userspace RCU library - test program (with baatch reclamation)
   5  *
   6  * Copyright February 2009 - Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with this program; if not, write to the Free Software Foundation, Inc.,
  20  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22
  23 #define _GNU_SOURCE
  24 #include <stdio.h>
  25 #include <pthread.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <sys/types.h>
  29 #include <sys/wait.h>
  30 #include <unistd.h>
  31 #include <stdio.h>
  32 #include <assert.h>
  33 #include <sys/syscall.h>
  34 #include <sched.h>
  35 #include <errno.h>
  36
  37 #include <urcu/arch.h>
  38
  39 /* hardcoded number of CPUs */
  40 #define NR_CPUS 16384
  41
  42 #if defined(_syscall0)
  43 _syscall0(pid_t, gettid)
  44 #elif defined(__NR_gettid)
  45 static inline pid_t gettid(void)
  46 {
  47         return syscall(__NR_gettid);
  48 }
  49 #else
  50 #warning "use pid as tid"
  51 static inline pid_t gettid(void)
  52 {
  53         return getpid();
  54 }
  55 #endif
  56
  57 #ifndef DYNAMIC_LINK_TEST
  58 #define _LGPL_SOURCE
  59 #else
  60 #define debug_yield_read()
  61 #endif
  62 #include <urcu.h>
  63
  64 struct test_array {
  65         int a;
  66 };
  67
  68 static volatile int test_go, test_stop;
  69
  70 static unsigned long wdelay;
  71
  72 static struct test_array *test_rcu_pointer;
  73
  74 static unsigned int reclaim_batch = 1;
  75
  76 struct reclaim_queue {
  77         void **queue;   /* Beginning of queue */
  78         void **head;    /* Insert position */
  79 };
  80
  81 static struct reclaim_queue *pending_reclaims;
  82
  83 static unsigned long duration;
  84
  85 /* read-side C.S. duration, in loops */
  86 static unsigned long rduration;
  87
  88 static inline void loop_sleep(unsigned long l)
  89 {
  90         while(l-- != 0)
  91                 cpu_relax();
  92 }
  93
  94 static int verbose_mode;
  95
  96 #define printf_verbose(fmt, args...)            \
  97         do {                                    \
  98                 if (verbose_mode)               \
  99                         printf(fmt, args);      \
 100         } while (0)
 101
 102 static unsigned int cpu_affinities[NR_CPUS];
 103 static unsigned int next_aff = 0;
 104 static int use_affinity = 0;
 105
 106 pthread_mutex_t affinity_mutex = PTHREAD_MUTEX_INITIALIZER;
 107
 108 static void set_affinity(void)
 109 {
 110         cpu_set_t mask;
 111         int cpu;
 112         int ret;
 113
 114         if (!use_affinity)
 115                 return;
 116
 117         ret = pthread_mutex_lock(&affinity_mutex);
 118         if (ret) {
 119                 perror("Error in pthread mutex lock");
 120                 exit(-1);
 121         }
 122         cpu = cpu_affinities[next_aff++];
 123         ret = pthread_mutex_unlock(&affinity_mutex);
 124         if (ret) {
 125                 perror("Error in pthread mutex unlock");
 126                 exit(-1);
 127         }
 128         CPU_ZERO(&mask);
 129         CPU_SET(cpu, &mask);
 130         sched_setaffinity(0, sizeof(mask), &mask);
 131 }
 132
 133 /*
 134  * returns 0 if test should end.
 135  */
 136 static int test_duration_write(void)
 137 {
 138         return !test_stop;
 139 }
 140
 141 static int test_duration_read(void)
 142 {
 143         return !test_stop;
 144 }
 145
 146 static unsigned long long __thread nr_writes;
 147 static unsigned long long __thread nr_reads;
 148
 149 static
 150 unsigned long long __attribute__((aligned(CACHE_LINE_SIZE))) *tot_nr_writes;
 151
 152 static unsigned int nr_readers;
 153 static unsigned int nr_writers;
 154
 155 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
 156
 157 void rcu_copy_mutex_lock(void)
 158 {
 159         int ret;
 160         ret = pthread_mutex_lock(&rcu_copy_mutex);
 161         if (ret) {
 162                 perror("Error in pthread mutex lock");
 163                 exit(-1);
 164         }
 165 }
 166
 167 void rcu_copy_mutex_unlock(void)
 168 {
 169         int ret;
 170
 171         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 172         if (ret) {
 173                 perror("Error in pthread mutex unlock");
 174                 exit(-1);
 175         }
 176 }
 177
 178 void *thr_reader(void *_count)
 179 {
 180         unsigned long long *count = _count;
 181         struct test_array *local_ptr;
 182
 183         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 184                         "reader", pthread_self(), (unsigned long)gettid());
 185
 186         set_affinity();
 187
 188         rcu_register_thread();
 189
 190         while (!test_go)
 191         {
 192         }
 193         smp_mb();
 194
 195         for (;;) {
 196                 rcu_read_lock();
 197                 local_ptr = rcu_dereference(test_rcu_pointer);
 198                 debug_yield_read();
 199                 if (local_ptr)
 200                         assert(local_ptr->a == 8);
 201                 if (unlikely(rduration))
 202                         loop_sleep(rduration);
 203                 rcu_read_unlock();
 204                 nr_reads++;
 205                 if (unlikely(!test_duration_read()))
 206                         break;
 207         }
 208
 209         rcu_unregister_thread();
 210
 211         *count = nr_reads;
 212         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 213                         "reader", pthread_self(), (unsigned long)gettid());
 214         return ((void*)1);
 215
 216 }
 217
 218 static void rcu_gc_clear_queue(unsigned long wtidx)
 219 {
 220         void **p;
 221
 222         /* Wait for Q.S and empty queue */
 223         synchronize_rcu();
 224
 225         for (p = pending_reclaims[wtidx].queue;
 226                         p < pending_reclaims[wtidx].head; p++) {
 227                 /* poison */
 228                 if (*p)
 229                         ((struct test_array *)*p)->a = 0;
 230                 free(*p);
 231         }
 232         pending_reclaims[wtidx].head = pending_reclaims[wtidx].queue;
 233 }
 234
 235 /* Using per-thread queue */
 236 static void rcu_gc_reclaim(unsigned long wtidx, void *old)
 237 {
 238         /* Queue pointer */
 239         *pending_reclaims[wtidx].head = old;
 240         pending_reclaims[wtidx].head++;
 241
 242         if (likely(pending_reclaims[wtidx].head - pending_reclaims[wtidx].queue
 243                         < reclaim_batch))
 244                 return;
 245
 246         rcu_gc_clear_queue(wtidx);
 247 }
 248
 249 void *thr_writer(void *data)
 250 {
 251         unsigned long wtidx = (unsigned long)data;
 252 #ifdef TEST_LOCAL_GC
 253         struct test_array *old = NULL;
 254 #else
 255         struct test_array *new, *old;
 256 #endif
 257
 258         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 259                         "writer", pthread_self(), (unsigned long)gettid());
 260
 261         set_affinity();
 262
 263         while (!test_go)
 264         {
 265         }
 266         smp_mb();
 267
 268         for (;;) {
 269 #ifndef TEST_LOCAL_GC
 270                 new = malloc(sizeof(*new));
 271                 new->a = 8;
 272                 old = rcu_xchg_pointer(&test_rcu_pointer, new);
 273 #endif
 274                 rcu_gc_reclaim(wtidx, old);
 275                 nr_writes++;
 276                 if (unlikely(!test_duration_write()))
 277                         break;
 278                 if (unlikely(wdelay))
 279                         loop_sleep(wdelay);
 280         }
 281
 282         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 283                         "writer", pthread_self(), (unsigned long)gettid());
 284         tot_nr_writes[wtidx] = nr_writes;
 285         return ((void*)2);
 286 }
 287
 288 void show_usage(int argc, char **argv)
 289 {
 290         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 291 #ifdef DEBUG_YIELD
 292         printf(" [-r] [-w] (yield reader and/or writer)");
 293 #endif
 294         printf(" [-d delay] (writer period (us))");
 295         printf(" [-c duration] (reader C.S. duration (in loops))");
 296         printf(" [-v] (verbose output)");
 297         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 298         printf("\n");
 299 }
 300
 301 int main(int argc, char **argv)
 302 {
 303         int err;
 304         pthread_t *tid_reader, *tid_writer;
 305         void *tret;
 306         unsigned long long *count_reader;
 307         unsigned long long tot_reads = 0, tot_writes = 0;
 308         int i, a;
 309
 310         if (argc < 4) {
 311                 show_usage(argc, argv);
 312                 return -1;
 313         }
 314
 315         err = sscanf(argv[1], "%u", &nr_readers);
 316         if (err != 1) {
 317                 show_usage(argc, argv);
 318                 return -1;
 319         }
 320
 321         err = sscanf(argv[2], "%u", &nr_writers);
 322         if (err != 1) {
 323                 show_usage(argc, argv);
 324                 return -1;
 325         }
 326
 327         err = sscanf(argv[3], "%lu", &duration);
 328         if (err != 1) {
 329                 show_usage(argc, argv);
 330                 return -1;
 331         }
 332
 333         for (i = 4; i < argc; i++) {
 334                 if (argv[i][0] != '-')
 335                         continue;
 336                 switch (argv[i][1]) {
 337 #ifdef DEBUG_YIELD
 338                 case 'r':
 339                         yield_active |= YIELD_READ;
 340                         break;
 341                 case 'w':
 342                         yield_active |= YIELD_WRITE;
 343                         break;
 344 #endif
 345                 case 'a':
 346                         if (argc < i + 2) {
 347                                 show_usage(argc, argv);
 348                                 return -1;
 349                         }
 350                         a = atoi(argv[++i]);
 351                         cpu_affinities[next_aff++] = a;
 352                         use_affinity = 1;
 353                         printf_verbose("Adding CPU %d affinity\n", a);
 354                         break;
 355                 case 'b':
 356                         if (argc < i + 2) {
 357                                 show_usage(argc, argv);
 358                                 return -1;
 359                         }
 360                         reclaim_batch = atol(argv[++i]);
 361                         break;
 362                 case 'c':
 363                         if (argc < i + 2) {
 364                                 show_usage(argc, argv);
 365                                 return -1;
 366                         }
 367                         rduration = atol(argv[++i]);
 368                         break;
 369                 case 'd':
 370                         if (argc < i + 2) {
 371                                 show_usage(argc, argv);
 372                                 return -1;
 373                         }
 374                         wdelay = atol(argv[++i]);
 375                         break;
 376                 case 'v':
 377                         verbose_mode = 1;
 378                         break;
 379                 }
 380         }
 381
 382         printf_verbose("running test for %lu seconds, %u readers, %u writers.\n",
 383                 duration, nr_readers, nr_writers);
 384         printf_verbose("Writer delay : %lu loops.\n", wdelay);
 385         printf_verbose("Reader duration : %lu loops.\n", rduration);
 386         printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
 387                         "main", pthread_self(), (unsigned long)gettid());
 388
 389         tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
 390         tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
 391         count_reader = malloc(sizeof(*count_reader) * nr_readers);
 392         tot_nr_writes = malloc(sizeof(*tot_nr_writes) * nr_writers);
 393         pending_reclaims = malloc(sizeof(*pending_reclaims) * nr_writers);
 394         if (reclaim_batch * sizeof(*pending_reclaims[i].queue)
 395                         < CACHE_LINE_SIZE)
 396                 for (i = 0; i < nr_writers; i++)
 397                         pending_reclaims[i].queue = calloc(1, CACHE_LINE_SIZE);
 398         else
 399                 for (i = 0; i < nr_writers; i++)
 400                         pending_reclaims[i].queue = calloc(reclaim_batch,
 401                                         sizeof(*pending_reclaims[i].queue));
 402         for (i = 0; i < nr_writers; i++)
 403                 pending_reclaims[i].head = pending_reclaims[i].queue;
 404
 405         next_aff = 0;
 406
 407         for (i = 0; i < nr_readers; i++) {
 408                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 409                                      &count_reader[i]);
 410                 if (err != 0)
 411                         exit(1);
 412         }
 413         for (i = 0; i < nr_writers; i++) {
 414                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 415                                      (void *)(long)i);
 416                 if (err != 0)
 417                         exit(1);
 418         }
 419
 420         smp_mb();
 421
 422         test_go = 1;
 423
 424         sleep(duration);
 425
 426         test_stop = 1;
 427
 428         for (i = 0; i < nr_readers; i++) {
 429                 err = pthread_join(tid_reader[i], &tret);
 430                 if (err != 0)
 431                         exit(1);
 432                 tot_reads += count_reader[i];
 433         }
 434         for (i = 0; i < nr_writers; i++) {
 435                 err = pthread_join(tid_writer[i], &tret);
 436                 if (err != 0)
 437                         exit(1);
 438                 tot_writes += tot_nr_writes[i];
 439                 rcu_gc_clear_queue(i);
 440         }
 441
 442         printf_verbose("total number of reads : %llu, writes %llu\n", tot_reads,
 443                tot_writes);
 444         printf("SUMMARY %-25s testdur %4lu nr_readers %3u rdur %6lu "
 445                 "nr_writers %3u "
 446                 "wdelay %6lu nr_reads %12llu nr_writes %12llu nr_ops %12llu "
 447                 "batch %u\n",
 448                 argv[0], duration, nr_readers, rduration,
 449                 nr_writers, wdelay, tot_reads, tot_writes,
 450                 tot_reads + tot_writes, reclaim_batch);
 451         free(tid_reader);
 452         free(tid_writer);
 453         free(count_reader);
 454         free(tot_nr_writes);
 455         for (i = 0; i < nr_writers; i++)
 456                 free(pending_reclaims[i].queue);
 457         free(pending_reclaims);
 458
 459         return 0;
 460 }