tests/test_qsbr.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-qsbr.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 static inline void loop_sleep(unsigned long l)
  81 {
  82         while(l-- != 0)
  83                 cpu_relax();
  84 }
  85
  86 static int verbose_mode;
  87
  88 #define printf_verbose(fmt, args...)            \
  89         do {                                    \
  90                 if (verbose_mode)               \
  91                         printf(fmt, args);      \
  92         } while (0)
  93
  94 static unsigned int cpu_affinities[NR_CPUS];
  95 static unsigned int next_aff = 0;
  96 static int use_affinity = 0;
  97
  98 pthread_mutex_t affinity_mutex = PTHREAD_MUTEX_INITIALIZER;
  99
 100 #ifndef HAVE_CPU_SET_T
 101 typedef unsigned long cpu_set_t;
 102 # define CPU_ZERO(cpuset) do { *(cpuset) = 0; } while(0)
 103 # define CPU_SET(cpu, cpuset) do { *(cpuset) |= (1UL << (cpu)); } while(0)
 104 #endif
 105
 106 static void set_affinity(void)
 107 {
 108         cpu_set_t mask;
 109         int cpu;
 110         int ret;
 111
 112         if (!use_affinity)
 113                 return;
 114
 115 #if HAVE_SCHED_SETAFFINITY
 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 #if SCHED_SETAFFINITY_ARGS == 2
 130         sched_setaffinity(0, &mask);
 131 #else
 132         sched_setaffinity(0, sizeof(mask), &mask);
 133 #endif
 134 #endif /* HAVE_SCHED_SETAFFINITY */
 135 }
 136
 137 /*
 138  * returns 0 if test should end.
 139  */
 140 static int test_duration_write(void)
 141 {
 142         return !test_stop;
 143 }
 144
 145 static int test_duration_read(void)
 146 {
 147         return !test_stop;
 148 }
 149
 150 static unsigned long long __thread nr_writes;
 151 static unsigned long long __thread nr_reads;
 152
 153 static unsigned int nr_readers;
 154 static unsigned int nr_writers;
 155
 156 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
 157
 158 void rcu_copy_mutex_lock(void)
 159 {
 160         int ret;
 161         ret = pthread_mutex_lock(&rcu_copy_mutex);
 162         if (ret) {
 163                 perror("Error in pthread mutex lock");
 164                 exit(-1);
 165         }
 166 }
 167
 168 void rcu_copy_mutex_unlock(void)
 169 {
 170         int ret;
 171
 172         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 173         if (ret) {
 174                 perror("Error in pthread mutex unlock");
 175                 exit(-1);
 176         }
 177 }
 178
 179 /*
 180  * malloc/free are reusing memory areas too quickly, which does not let us
 181  * test races appropriately. Use a large circular array for allocations.
 182  * ARRAY_SIZE is larger than nr_writers, which insures we never run over our tail.
 183  */
 184 #define ARRAY_SIZE (1048576 * nr_writers)
 185 #define ARRAY_POISON 0xDEADBEEF
 186 static int array_index;
 187 static struct test_array *test_array;
 188
 189 static struct test_array *test_array_alloc(void)
 190 {
 191         struct test_array *ret;
 192         int index;
 193
 194         rcu_copy_mutex_lock();
 195         index = array_index % ARRAY_SIZE;
 196         assert(test_array[index].a == ARRAY_POISON ||
 197                 test_array[index].a == 0);
 198         ret = &test_array[index];
 199         array_index++;
 200         if (array_index == ARRAY_SIZE)
 201                 array_index = 0;
 202         rcu_copy_mutex_unlock();
 203         return ret;
 204 }
 205
 206 static void test_array_free(struct test_array *ptr)
 207 {
 208         if (!ptr)
 209                 return;
 210         rcu_copy_mutex_lock();
 211         ptr->a = ARRAY_POISON;
 212         rcu_copy_mutex_unlock();
 213 }
 214
 215 void *thr_reader(void *_count)
 216 {
 217         unsigned long long *count = _count;
 218         struct test_array *local_ptr;
 219
 220         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 221                         "reader", pthread_self(), (unsigned long)gettid());
 222
 223         set_affinity();
 224
 225         rcu_register_thread();
 226
 227         while (!test_go)
 228         {
 229         }
 230         smp_mb();
 231
 232         for (;;) {
 233                 rcu_read_lock();
 234                 local_ptr = rcu_dereference(test_rcu_pointer);
 235                 debug_yield_read();
 236                 if (local_ptr)
 237                         assert(local_ptr->a == 8);
 238                 if (unlikely(rduration))
 239                         loop_sleep(rduration);
 240                 rcu_read_unlock();
 241                 nr_reads++;
 242                 /* QS each 1024 reads */
 243                 if (unlikely((nr_reads & ((1 << 10) - 1)) == 0))
 244                         rcu_quiescent_state();
 245                 if (unlikely(!test_duration_read()))
 246                         break;
 247         }
 248
 249         rcu_unregister_thread();
 250
 251         *count = nr_reads;
 252         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 253                         "reader", pthread_self(), (unsigned long)gettid());
 254         return ((void*)1);
 255
 256 }
 257
 258 void *thr_writer(void *_count)
 259 {
 260         unsigned long long *count = _count;
 261         struct test_array *new, *old;
 262
 263         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 264                         "writer", pthread_self(), (unsigned long)gettid());
 265
 266         set_affinity();
 267
 268         while (!test_go)
 269         {
 270         }
 271         smp_mb();
 272
 273         for (;;) {
 274                 new = test_array_alloc();
 275                 new->a = 8;
 276                 old = rcu_xchg_pointer(&test_rcu_pointer, new);
 277                 synchronize_rcu();
 278                 /* can be done after unlock */
 279                 if (old)
 280                         old->a = 0;
 281                 test_array_free(old);
 282                 nr_writes++;
 283                 if (unlikely(!test_duration_write()))
 284                         break;
 285                 if (unlikely(wdelay))
 286                         loop_sleep(wdelay);
 287         }
 288
 289         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 290                         "writer", pthread_self(), (unsigned long)gettid());
 291         *count = nr_writes;
 292         return ((void*)2);
 293 }
 294
 295 void show_usage(int argc, char **argv)
 296 {
 297         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 298 #ifdef DEBUG_YIELD
 299         printf(" [-r] [-w] (yield reader and/or writer)");
 300 #endif
 301         printf(" [-d delay] (writer period (us))");
 302         printf(" [-c duration] (reader C.S. duration (in loops))");
 303         printf(" [-v] (verbose output)");
 304         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 305         printf("\n");
 306 }
 307
 308 int main(int argc, char **argv)
 309 {
 310         int err;
 311         pthread_t *tid_reader, *tid_writer;
 312         void *tret;
 313         unsigned long long *count_reader, *count_writer;
 314         unsigned long long tot_reads = 0, tot_writes = 0;
 315         int i, a;
 316
 317         if (argc < 4) {
 318                 show_usage(argc, argv);
 319                 return -1;
 320         }
 321
 322         err = sscanf(argv[1], "%u", &nr_readers);
 323         if (err != 1) {
 324                 show_usage(argc, argv);
 325                 return -1;
 326         }
 327
 328         err = sscanf(argv[2], "%u", &nr_writers);
 329         if (err != 1) {
 330                 show_usage(argc, argv);
 331                 return -1;
 332         }
 333
 334         err = sscanf(argv[3], "%lu", &duration);
 335         if (err != 1) {
 336                 show_usage(argc, argv);
 337                 return -1;
 338         }
 339
 340         for (i = 4; i < argc; i++) {
 341                 if (argv[i][0] != '-')
 342                         continue;
 343                 switch (argv[i][1]) {
 344 #ifdef DEBUG_YIELD
 345                 case 'r':
 346                         yield_active |= YIELD_READ;
 347                         break;
 348                 case 'w':
 349                         yield_active |= YIELD_WRITE;
 350                         break;
 351 #endif
 352                 case 'a':
 353                         if (argc < i + 2) {
 354                                 show_usage(argc, argv);
 355                                 return -1;
 356                         }
 357                         a = atoi(argv[++i]);
 358                         cpu_affinities[next_aff++] = a;
 359                         use_affinity = 1;
 360                         printf_verbose("Adding CPU %d affinity\n", a);
 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         test_array = malloc(sizeof(*test_array) * ARRAY_SIZE);
 390         tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
 391         tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
 392         count_reader = malloc(sizeof(*count_reader) * nr_readers);
 393         count_writer = malloc(sizeof(*count_writer) * nr_writers);
 394
 395         next_aff = 0;
 396
 397         for (i = 0; i < nr_readers; i++) {
 398                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 399                                      &count_reader[i]);
 400                 if (err != 0)
 401                         exit(1);
 402         }
 403         for (i = 0; i < nr_writers; i++) {
 404                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 405                                      &count_writer[i]);
 406                 if (err != 0)
 407                         exit(1);
 408         }
 409
 410         smp_mb();
 411
 412         test_go = 1;
 413
 414         sleep(duration);
 415
 416         test_stop = 1;
 417
 418         for (i = 0; i < nr_readers; i++) {
 419                 err = pthread_join(tid_reader[i], &tret);
 420                 if (err != 0)
 421                         exit(1);
 422                 tot_reads += count_reader[i];
 423         }
 424         for (i = 0; i < nr_writers; i++) {
 425                 err = pthread_join(tid_writer[i], &tret);
 426                 if (err != 0)
 427                         exit(1);
 428                 tot_writes += count_writer[i];
 429         }
 430
 431         printf_verbose("total number of reads : %llu, writes %llu\n", tot_reads,
 432                tot_writes);
 433         printf("SUMMARY %-25s testdur %4lu nr_readers %3u rdur %6lu "
 434                 "nr_writers %3u "
 435                 "wdelay %6lu nr_reads %12llu nr_writes %12llu nr_ops %12llu\n",
 436                 argv[0], duration, nr_readers, rduration,
 437                 nr_writers, wdelay, tot_reads, tot_writes,
 438                 tot_reads + tot_writes);
 439         test_array_free(test_rcu_pointer);
 440         free(test_array);
 441         free(tid_reader);
 442         free(tid_writer);
 443         free(count_reader);
 444         free(count_writer);
 445         return 0;
 446 }