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