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 <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 "../arch.h"
  37
  38 /* Make this big enough to include the POWER5+ L3 cacheline size of 256B */
  39 #define CACHE_LINE_SIZE 4096
  40
  41 /* hardcoded number of CPUs */
  42 #define NR_CPUS 16384
  43
  44 #if defined(_syscall0)
  45 _syscall0(pid_t, gettid)
  46 #elif defined(__NR_gettid)
  47 static inline pid_t gettid(void)
  48 {
  49         return syscall(__NR_gettid);
  50 }
  51 #else
  52 #warning "use pid as tid"
  53 static inline pid_t gettid(void)
  54 {
  55         return getpid();
  56 }
  57 #endif
  58
  59 #ifndef DYNAMIC_LINK_TEST
  60 #define _LGPL_SOURCE
  61 #else
  62 #define debug_yield_read()
  63 #endif
  64 #include "../urcu.h"
  65
  66 struct test_array {
  67         int a;
  68 };
  69
  70 static volatile int test_go, test_stop;
  71
  72 static unsigned long wdelay;
  73
  74 static struct test_array *test_rcu_pointer;
  75
  76 static unsigned long duration;
  77
  78 /* read-side C.S. duration, in loops */
  79 static unsigned long rduration;
  80
  81 static inline void loop_sleep(unsigned long l)
  82 {
  83         while(l-- != 0)
  84                 cpu_relax();
  85 }
  86
  87 static int verbose_mode;
  88
  89 #define printf_verbose(fmt, args...)            \
  90         do {                                    \
  91                 if (verbose_mode)               \
  92                         printf(fmt, args);      \
  93         } while (0)
  94
  95 static unsigned int cpu_affinities[NR_CPUS];
  96 static unsigned int next_aff = 0;
  97 static int use_affinity = 0;
  98
  99 pthread_mutex_t affinity_mutex = PTHREAD_MUTEX_INITIALIZER;
 100
 101 static void set_affinity(void)
 102 {
 103         cpu_set_t mask;
 104         int cpu;
 105         int ret;
 106
 107         if (!use_affinity)
 108                 return;
 109
 110         ret = pthread_mutex_lock(&affinity_mutex);
 111         if (ret) {
 112                 perror("Error in pthread mutex lock");
 113                 exit(-1);
 114         }
 115         cpu = cpu_affinities[next_aff++];
 116         ret = pthread_mutex_unlock(&affinity_mutex);
 117         if (ret) {
 118                 perror("Error in pthread mutex unlock");
 119                 exit(-1);
 120         }
 121         CPU_ZERO(&mask);
 122         CPU_SET(cpu, &mask);
 123         sched_setaffinity(0, sizeof(mask), &mask);
 124 }
 125
 126 /*
 127  * returns 0 if test should end.
 128  */
 129 static int test_duration_write(void)
 130 {
 131         return !test_stop;
 132 }
 133
 134 static int test_duration_read(void)
 135 {
 136         return !test_stop;
 137 }
 138
 139 static unsigned long long __thread nr_writes;
 140 static unsigned long long __thread nr_reads;
 141
 142 static unsigned int nr_readers;
 143 static unsigned int nr_writers;
 144
 145 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
 146
 147 void rcu_copy_mutex_lock(void)
 148 {
 149         int ret;
 150         ret = pthread_mutex_lock(&rcu_copy_mutex);
 151         if (ret) {
 152                 perror("Error in pthread mutex lock");
 153                 exit(-1);
 154         }
 155 }
 156
 157 void rcu_copy_mutex_unlock(void)
 158 {
 159         int ret;
 160
 161         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 162         if (ret) {
 163                 perror("Error in pthread mutex unlock");
 164                 exit(-1);
 165         }
 166 }
 167
 168 /*
 169  * malloc/free are reusing memory areas too quickly, which does not let us
 170  * test races appropriately. Use a large circular array for allocations.
 171  * ARRAY_SIZE is larger than nr_writers, which insures we never run over our tail.
 172  */
 173 #define ARRAY_SIZE (1048576 * nr_writers)
 174 #define ARRAY_POISON 0xDEADBEEF
 175 static int array_index;
 176 static struct test_array *test_array;
 177
 178 static struct test_array *test_array_alloc(void)
 179 {
 180         struct test_array *ret;
 181         int index;
 182
 183         rcu_copy_mutex_lock();
 184         index = array_index % ARRAY_SIZE;
 185         assert(test_array[index].a == ARRAY_POISON ||
 186                 test_array[index].a == 0);
 187         ret = &test_array[index];
 188         array_index++;
 189         if (array_index == ARRAY_SIZE)
 190                 array_index = 0;
 191         rcu_copy_mutex_unlock();
 192         return ret;
 193 }
 194
 195 static void test_array_free(struct test_array *ptr)
 196 {
 197         if (!ptr)
 198                 return;
 199         rcu_copy_mutex_lock();
 200         ptr->a = ARRAY_POISON;
 201         rcu_copy_mutex_unlock();
 202 }
 203
 204 void *thr_reader(void *_count)
 205 {
 206         unsigned long long *count = _count;
 207         struct test_array *local_ptr;
 208
 209         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 210                         "reader", pthread_self(), (unsigned long)gettid());
 211
 212         set_affinity();
 213
 214         rcu_register_thread();
 215
 216         while (!test_go)
 217         {
 218         }
 219         smp_mb();
 220
 221         for (;;) {
 222                 rcu_read_lock();
 223                 local_ptr = rcu_dereference(test_rcu_pointer);
 224                 debug_yield_read();
 225                 if (local_ptr)
 226                         assert(local_ptr->a == 8);
 227                 if (unlikely(rduration))
 228                         loop_sleep(rduration);
 229                 rcu_read_unlock();
 230                 nr_reads++;
 231                 if (unlikely(!test_duration_read()))
 232                         break;
 233         }
 234
 235         rcu_unregister_thread();
 236
 237         *count = nr_reads;
 238         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 239                         "reader", pthread_self(), (unsigned long)gettid());
 240         return ((void*)1);
 241
 242 }
 243
 244 void *thr_writer(void *_count)
 245 {
 246         unsigned long long *count = _count;
 247         struct test_array *new, *old;
 248
 249         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 250                         "writer", pthread_self(), (unsigned long)gettid());
 251
 252         set_affinity();
 253
 254         while (!test_go)
 255         {
 256         }
 257         smp_mb();
 258
 259         for (;;) {
 260                 new = test_array_alloc();
 261                 new->a = 8;
 262                 old = rcu_publish_content(&test_rcu_pointer, new);
 263                 if (old)
 264                         old->a = 0;
 265                 test_array_free(old);
 266                 nr_writes++;
 267                 if (unlikely(!test_duration_write()))
 268                         break;
 269                 if (unlikely(wdelay))
 270                         loop_sleep(wdelay);
 271         }
 272
 273         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 274                         "writer", pthread_self(), (unsigned long)gettid());
 275         *count = nr_writes;
 276         return ((void*)2);
 277 }
 278
 279 void show_usage(int argc, char **argv)
 280 {
 281         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 282 #ifdef DEBUG_YIELD
 283         printf(" [-r] [-w] (yield reader and/or writer)");
 284 #endif
 285         printf(" [-d delay] (writer period (us))");
 286         printf(" [-c duration] (reader C.S. duration (in loops))");
 287         printf(" [-v] (verbose output)");
 288         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 289         printf("\n");
 290 }
 291
 292 int main(int argc, char **argv)
 293 {
 294         int err;
 295         pthread_t *tid_reader, *tid_writer;
 296         void *tret;
 297         unsigned long long *count_reader, *count_writer;
 298         unsigned long long tot_reads = 0, tot_writes = 0;
 299         int i, a;
 300
 301         if (argc < 4) {
 302                 show_usage(argc, argv);
 303                 return -1;
 304         }
 305
 306         err = sscanf(argv[1], "%u", &nr_readers);
 307         if (err != 1) {
 308                 show_usage(argc, argv);
 309                 return -1;
 310         }
 311
 312         err = sscanf(argv[2], "%u", &nr_writers);
 313         if (err != 1) {
 314                 show_usage(argc, argv);
 315                 return -1;
 316         }
 317
 318         err = sscanf(argv[3], "%lu", &duration);
 319         if (err != 1) {
 320                 show_usage(argc, argv);
 321                 return -1;
 322         }
 323
 324         for (i = 4; i < argc; i++) {
 325                 if (argv[i][0] != '-')
 326                         continue;
 327                 switch (argv[i][1]) {
 328 #ifdef DEBUG_YIELD
 329                 case 'r':
 330                         yield_active |= YIELD_READ;
 331                         break;
 332                 case 'w':
 333                         yield_active |= YIELD_WRITE;
 334                         break;
 335 #endif
 336                 case 'a':
 337                         if (argc < i + 2) {
 338                                 show_usage(argc, argv);
 339                                 return -1;
 340                         }
 341                         a = atoi(argv[++i]);
 342                         cpu_affinities[next_aff++] = a;
 343                         use_affinity = 1;
 344                         printf_verbose("Adding CPU %d affinity\n", a);
 345                         break;
 346                 case 'c':
 347                         if (argc < i + 2) {
 348                                 show_usage(argc, argv);
 349                                 return -1;
 350                         }
 351                         rduration = atol(argv[++i]);
 352                         break;
 353                 case 'd':
 354                         if (argc < i + 2) {
 355                                 show_usage(argc, argv);
 356                                 return -1;
 357                         }
 358                         wdelay = atol(argv[++i]);
 359                         break;
 360                 case 'v':
 361                         verbose_mode = 1;
 362                         break;
 363                 }
 364         }
 365
 366         printf_verbose("running test for %lu seconds, %u readers, %u writers.\n",
 367                 duration, nr_readers, nr_writers);
 368         printf_verbose("Writer delay : %lu loops.\n", wdelay);
 369         printf_verbose("Reader duration : %lu loops.\n", rduration);
 370         printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
 371                         "main", pthread_self(), (unsigned long)gettid());
 372
 373         test_array = malloc(sizeof(*test_array) * ARRAY_SIZE);
 374         tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
 375         tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
 376         count_reader = malloc(sizeof(*count_reader) * nr_readers);
 377         count_writer = malloc(sizeof(*count_writer) * nr_writers);
 378
 379         next_aff = 0;
 380
 381         for (i = 0; i < nr_readers; i++) {
 382                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 383                                      &count_reader[i]);
 384                 if (err != 0)
 385                         exit(1);
 386         }
 387         for (i = 0; i < nr_writers; i++) {
 388                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 389                                      &count_writer[i]);
 390                 if (err != 0)
 391                         exit(1);
 392         }
 393
 394         smp_mb();
 395
 396         test_go = 1;
 397
 398         sleep(duration);
 399
 400         test_stop = 1;
 401
 402         for (i = 0; i < nr_readers; i++) {
 403                 err = pthread_join(tid_reader[i], &tret);
 404                 if (err != 0)
 405                         exit(1);
 406                 tot_reads += count_reader[i];
 407         }
 408         for (i = 0; i < nr_writers; i++) {
 409                 err = pthread_join(tid_writer[i], &tret);
 410                 if (err != 0)
 411                         exit(1);
 412                 tot_writes += count_writer[i];
 413         }
 414
 415         printf_verbose("total number of reads : %llu, writes %llu\n", tot_reads,
 416                tot_writes);
 417         printf("SUMMARY %-25s testdur %4lu nr_readers %3u rdur %6lu "
 418                 "nr_writers %3u "
 419                 "wdelay %6lu nr_reads %12llu nr_writes %12llu nr_ops %12llu\n",
 420                 argv[0], duration, nr_readers, rduration,
 421                 nr_writers, wdelay, tot_reads, tot_writes,
 422                 tot_reads + tot_writes);
 423         test_array_free(test_rcu_pointer);
 424         free(test_array);
 425         free(tid_reader);
 426         free(tid_writer);
 427         free(count_reader);
 428         free(count_writer);
 429         return 0;
 430 }