tests/test_urcu.c

   1 /*
   2  * test_urcu.c
   3  *
   4  * Userspace RCU library - test program
   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 "../config.h"
  25 #include <stdio.h>
  26 #include <pthread.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <sys/types.h>
  30 #include <sys/wait.h>
  31 #include <unistd.h>
  32 #include <stdio.h>
  33 #include <assert.h>
  34 #include <sys/syscall.h>
  35 #include <sched.h>
  36 #include <errno.h>
  37
  38 #include <urcu/arch.h>
  39
  40 /* hardcoded number of CPUs */
  41 #define NR_CPUS 16384
  42
  43 #if defined(_syscall0)
  44 _syscall0(pid_t, gettid)
  45 #elif defined(__NR_gettid)
  46 static inline pid_t gettid(void)
  47 {
  48         return syscall(__NR_gettid);
  49 }
  50 #else
  51 #warning "use pid as tid"
  52 static inline pid_t gettid(void)
  53 {
  54         return getpid();
  55 }
  56 #endif
  57
  58 #ifndef DYNAMIC_LINK_TEST
  59 #define _LGPL_SOURCE
  60 #else
  61 #define debug_yield_read()
  62 #endif
  63 #include <urcu.h>
  64
  65 struct test_array {
  66         int a;
  67 };
  68
  69 static volatile int test_go, test_stop;
  70
  71 static unsigned long wdelay;
  72
  73 static struct test_array *test_rcu_pointer;
  74
  75 static unsigned long duration;
  76
  77 /* read-side C.S. duration, in loops */
  78 static unsigned long rduration;
  79
  80 /* write-side C.S. duration, in loops */
  81 static unsigned long wduration;
  82
  83 static inline void loop_sleep(unsigned long l)
  84 {
  85         while(l-- != 0)
  86                 cpu_relax();
  87 }
  88
  89 static int verbose_mode;
  90
  91 #define printf_verbose(fmt, args...)            \
  92         do {                                    \
  93                 if (verbose_mode)               \
  94                         printf(fmt, args);      \
  95         } while (0)
  96
  97 static unsigned int cpu_affinities[NR_CPUS];
  98 static unsigned int next_aff = 0;
  99 static int use_affinity = 0;
 100
 101 pthread_mutex_t affinity_mutex = PTHREAD_MUTEX_INITIALIZER;
 102
 103 #ifndef HAVE_CPU_SET_T
 104 typedef unsigned long cpu_set_t;
 105 # define CPU_ZERO(cpuset) do { *(cpuset) = 0; } while(0)
 106 # define CPU_SET(cpu, cpuset) do { *(cpuset) |= (1UL << (cpu)); } while(0)
 107 #endif
 108
 109 static void set_affinity(void)
 110 {
 111         cpu_set_t mask;
 112         int cpu;
 113         int ret;
 114
 115         if (!use_affinity)
 116                 return;
 117
 118 #if HAVE_SCHED_SETAFFINITY
 119         ret = pthread_mutex_lock(&affinity_mutex);
 120         if (ret) {
 121                 perror("Error in pthread mutex lock");
 122                 exit(-1);
 123         }
 124         cpu = cpu_affinities[next_aff++];
 125         ret = pthread_mutex_unlock(&affinity_mutex);
 126         if (ret) {
 127                 perror("Error in pthread mutex unlock");
 128                 exit(-1);
 129         }
 130
 131         CPU_ZERO(&mask);
 132         CPU_SET(cpu, &mask);
 133 #if SCHED_SETAFFINITY_ARGS == 2
 134         sched_setaffinity(0, &mask);
 135 #else
 136         sched_setaffinity(0, sizeof(mask), &mask);
 137 #endif
 138 #endif /* HAVE_SCHED_SETAFFINITY */
 139 }
 140
 141 /*
 142  * returns 0 if test should end.
 143  */
 144 static int test_duration_write(void)
 145 {
 146         return !test_stop;
 147 }
 148
 149 static int test_duration_read(void)
 150 {
 151         return !test_stop;
 152 }
 153
 154 static unsigned long long __thread nr_writes;
 155 static unsigned long long __thread nr_reads;
 156
 157 static unsigned int nr_readers;
 158 static unsigned int nr_writers;
 159
 160 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
 161
 162 void rcu_copy_mutex_lock(void)
 163 {
 164         int ret;
 165         ret = pthread_mutex_lock(&rcu_copy_mutex);
 166         if (ret) {
 167                 perror("Error in pthread mutex lock");
 168                 exit(-1);
 169         }
 170 }
 171
 172 void rcu_copy_mutex_unlock(void)
 173 {
 174         int ret;
 175
 176         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 177         if (ret) {
 178                 perror("Error in pthread mutex unlock");
 179                 exit(-1);
 180         }
 181 }
 182
 183 /*
 184  * malloc/free are reusing memory areas too quickly, which does not let us
 185  * test races appropriately. Use a large circular array for allocations.
 186  * ARRAY_SIZE is larger than nr_writers, which insures we never run over our tail.
 187  */
 188 #define ARRAY_SIZE (1048576 * nr_writers)
 189 #define ARRAY_POISON 0xDEADBEEF
 190 static int array_index;
 191 static struct test_array *test_array;
 192
 193 static struct test_array *test_array_alloc(void)
 194 {
 195         struct test_array *ret;
 196         int index;
 197
 198         rcu_copy_mutex_lock();
 199         index = array_index % ARRAY_SIZE;
 200         assert(test_array[index].a == ARRAY_POISON ||
 201                 test_array[index].a == 0);
 202         ret = &test_array[index];
 203         array_index++;
 204         if (array_index == ARRAY_SIZE)
 205                 array_index = 0;
 206         rcu_copy_mutex_unlock();
 207         return ret;
 208 }
 209
 210 static void test_array_free(struct test_array *ptr)
 211 {
 212         if (!ptr)
 213                 return;
 214         rcu_copy_mutex_lock();
 215         ptr->a = ARRAY_POISON;
 216         rcu_copy_mutex_unlock();
 217 }
 218
 219 void *thr_reader(void *_count)
 220 {
 221         unsigned long long *count = _count;
 222         struct test_array *local_ptr;
 223
 224         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 225                         "reader", pthread_self(), (unsigned long)gettid());
 226
 227         set_affinity();
 228
 229         rcu_register_thread();
 230
 231         while (!test_go)
 232         {
 233         }
 234         smp_mb();
 235
 236         for (;;) {
 237                 rcu_read_lock();
 238                 local_ptr = rcu_dereference(test_rcu_pointer);
 239                 debug_yield_read();
 240                 if (local_ptr)
 241                         assert(local_ptr->a == 8);
 242                 if (unlikely(rduration))
 243                         loop_sleep(rduration);
 244                 rcu_read_unlock();
 245                 nr_reads++;
 246                 if (unlikely(!test_duration_read()))
 247                         break;
 248         }
 249
 250         rcu_unregister_thread();
 251
 252         *count = nr_reads;
 253         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 254                         "reader", pthread_self(), (unsigned long)gettid());
 255         return ((void*)1);
 256
 257 }
 258
 259 void *thr_writer(void *_count)
 260 {
 261         unsigned long long *count = _count;
 262         struct test_array *new, *old;
 263
 264         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 265                         "writer", pthread_self(), (unsigned long)gettid());
 266
 267         set_affinity();
 268
 269         while (!test_go)
 270         {
 271         }
 272         smp_mb();
 273
 274         for (;;) {
 275                 new = test_array_alloc();
 276                 new->a = 8;
 277                 old = rcu_xchg_pointer(&test_rcu_pointer, new);
 278                 if (unlikely(wduration))
 279                         loop_sleep(wduration);
 280                 synchronize_rcu();
 281                 if (old)
 282                         old->a = 0;
 283                 test_array_free(old);
 284                 nr_writes++;
 285                 if (unlikely(!test_duration_write()))
 286                         break;
 287                 if (unlikely(wdelay))
 288                         loop_sleep(wdelay);
 289         }
 290
 291         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 292                         "writer", pthread_self(), (unsigned long)gettid());
 293         *count = nr_writes;
 294         return ((void*)2);
 295 }
 296
 297 void show_usage(int argc, char **argv)
 298 {
 299         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 300 #ifdef DEBUG_YIELD
 301         printf(" [-r] [-w] (yield reader and/or writer)");
 302 #endif
 303         printf(" [-d delay] (writer period (us))");
 304         printf(" [-c duration] (reader C.S. duration (in loops))");
 305         printf(" [-e duration] (writer C.S. duration (in loops))");
 306         printf(" [-v] (verbose output)");
 307         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 308         printf("\n");
 309 }
 310
 311 int main(int argc, char **argv)
 312 {
 313         int err;
 314         pthread_t *tid_reader, *tid_writer;
 315         void *tret;
 316         unsigned long long *count_reader, *count_writer;
 317         unsigned long long tot_reads = 0, tot_writes = 0;
 318         int i, a;
 319
 320         if (argc < 4) {
 321                 show_usage(argc, argv);
 322                 return -1;
 323         }
 324
 325         err = sscanf(argv[1], "%u", &nr_readers);
 326         if (err != 1) {
 327                 show_usage(argc, argv);
 328                 return -1;
 329         }
 330
 331         err = sscanf(argv[2], "%u", &nr_writers);
 332         if (err != 1) {
 333                 show_usage(argc, argv);
 334                 return -1;
 335         }
 336
 337         err = sscanf(argv[3], "%lu", &duration);
 338         if (err != 1) {
 339                 show_usage(argc, argv);
 340                 return -1;
 341         }
 342
 343         for (i = 4; i < argc; i++) {
 344                 if (argv[i][0] != '-')
 345                         continue;
 346                 switch (argv[i][1]) {
 347 #ifdef DEBUG_YIELD
 348                 case 'r':
 349                         yield_active |= YIELD_READ;
 350                         break;
 351                 case 'w':
 352                         yield_active |= YIELD_WRITE;
 353                         break;
 354 #endif
 355                 case 'a':
 356                         if (argc < i + 2) {
 357                                 show_usage(argc, argv);
 358                                 return -1;
 359                         }
 360                         a = atoi(argv[++i]);
 361                         cpu_affinities[next_aff++] = a;
 362                         use_affinity = 1;
 363                         printf_verbose("Adding CPU %d affinity\n", a);
 364                         break;
 365                 case 'c':
 366                         if (argc < i + 2) {
 367                                 show_usage(argc, argv);
 368                                 return -1;
 369                         }
 370                         rduration = atol(argv[++i]);
 371                         break;
 372                 case 'd':
 373                         if (argc < i + 2) {
 374                                 show_usage(argc, argv);
 375                                 return -1;
 376                         }
 377                         wdelay = atol(argv[++i]);
 378                         break;
 379                 case 'e':
 380                         if (argc < i + 2) {
 381                                 show_usage(argc, argv);
 382                                 return -1;
 383                         }
 384                         wduration = atol(argv[++i]);
 385                         break;
 386                 case 'v':
 387                         verbose_mode = 1;
 388                         break;
 389                 }
 390         }
 391
 392         printf_verbose("running test for %lu seconds, %u readers, %u writers.\n",
 393                 duration, nr_readers, nr_writers);
 394         printf_verbose("Writer delay : %lu loops.\n", wdelay);
 395         printf_verbose("Reader duration : %lu loops.\n", rduration);
 396         printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
 397                         "main", pthread_self(), (unsigned long)gettid());
 398
 399         test_array = malloc(sizeof(*test_array) * ARRAY_SIZE);
 400         tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
 401         tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
 402         count_reader = malloc(sizeof(*count_reader) * nr_readers);
 403         count_writer = malloc(sizeof(*count_writer) * nr_writers);
 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                                      &count_writer[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 += count_writer[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\n",
 446                 argv[0], duration, nr_readers, rduration,
 447                 nr_writers, wdelay, tot_reads, tot_writes,
 448                 tot_reads + tot_writes);
 449         test_array_free(test_rcu_pointer);
 450         free(test_array);
 451         free(tid_reader);
 452         free(tid_writer);
 453         free(count_reader);
 454         free(count_writer);
 455         return 0;
 456 }