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 <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 #define _LGPL_SOURCE
  60 #include "../urcu-qsbr.h"
  61
  62 struct test_array {
  63         int a;
  64 };
  65
  66 static volatile int test_go, test_stop;
  67
  68 static unsigned long wdelay;
  69
  70 static struct test_array *test_rcu_pointer;
  71
  72 static unsigned long duration;
  73
  74 /* read-side C.S. duration, in loops */
  75 static unsigned long rduration;
  76
  77 static inline void loop_sleep(unsigned long l)
  78 {
  79         while(l-- != 0)
  80                 cpu_relax();
  81 }
  82
  83 static int verbose_mode;
  84
  85 #define printf_verbose(fmt, args...)            \
  86         do {                                    \
  87                 if (verbose_mode)               \
  88                         printf(fmt, args);      \
  89         } while (0)
  90
  91 static unsigned int cpu_affinities[NR_CPUS];
  92 static unsigned int next_aff = 0;
  93 static int use_affinity = 0;
  94
  95 pthread_mutex_t affinity_mutex = PTHREAD_MUTEX_INITIALIZER;
  96
  97 static void set_affinity(void)
  98 {
  99         cpu_set_t mask;
 100         int cpu;
 101         int ret;
 102
 103         if (!use_affinity)
 104                 return;
 105
 106         ret = pthread_mutex_lock(&affinity_mutex);
 107         if (ret) {
 108                 perror("Error in pthread mutex lock");
 109                 exit(-1);
 110         }
 111         cpu = cpu_affinities[next_aff++];
 112         ret = pthread_mutex_unlock(&affinity_mutex);
 113         if (ret) {
 114                 perror("Error in pthread mutex unlock");
 115                 exit(-1);
 116         }
 117         CPU_ZERO(&mask);
 118         CPU_SET(cpu, &mask);
 119         sched_setaffinity(0, sizeof(mask), &mask);
 120 }
 121
 122 /*
 123  * returns 0 if test should end.
 124  */
 125 static int test_duration_write(void)
 126 {
 127         return !test_stop;
 128 }
 129
 130 static int test_duration_read(void)
 131 {
 132         return !test_stop;
 133 }
 134
 135 static unsigned long long __thread nr_writes;
 136 static unsigned long long __thread nr_reads;
 137
 138 static unsigned int nr_readers;
 139 static unsigned int nr_writers;
 140
 141 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
 142
 143 void rcu_copy_mutex_lock(void)
 144 {
 145         int ret;
 146         ret = pthread_mutex_lock(&rcu_copy_mutex);
 147         if (ret) {
 148                 perror("Error in pthread mutex lock");
 149                 exit(-1);
 150         }
 151 }
 152
 153 void rcu_copy_mutex_unlock(void)
 154 {
 155         int ret;
 156
 157         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 158         if (ret) {
 159                 perror("Error in pthread mutex unlock");
 160                 exit(-1);
 161         }
 162 }
 163
 164 /*
 165  * malloc/free are reusing memory areas too quickly, which does not let us
 166  * test races appropriately. Use a large circular array for allocations.
 167  * ARRAY_SIZE is larger than nr_writers, which insures we never run over our tail.
 168  */
 169 #define ARRAY_SIZE (1048576 * nr_writers)
 170 #define ARRAY_POISON 0xDEADBEEF
 171 static int array_index;
 172 static struct test_array *test_array;
 173
 174 static struct test_array *test_array_alloc(void)
 175 {
 176         struct test_array *ret;
 177         int index;
 178
 179         rcu_copy_mutex_lock();
 180         index = array_index % ARRAY_SIZE;
 181         assert(test_array[index].a == ARRAY_POISON ||
 182                 test_array[index].a == 0);
 183         ret = &test_array[index];
 184         array_index++;
 185         if (array_index == ARRAY_SIZE)
 186                 array_index = 0;
 187         rcu_copy_mutex_unlock();
 188         return ret;
 189 }
 190
 191 static void test_array_free(struct test_array *ptr)
 192 {
 193         if (!ptr)
 194                 return;
 195         rcu_copy_mutex_lock();
 196         ptr->a = ARRAY_POISON;
 197         rcu_copy_mutex_unlock();
 198 }
 199
 200 void *thr_reader(void *_count)
 201 {
 202         unsigned long long *count = _count;
 203         struct test_array *local_ptr;
 204
 205         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 206                         "reader", pthread_self(), (unsigned long)gettid());
 207
 208         set_affinity();
 209
 210         rcu_register_thread();
 211
 212         while (!test_go)
 213         {
 214         }
 215         smp_mb();
 216
 217         for (;;) {
 218                 _rcu_read_lock();
 219                 local_ptr = _rcu_dereference(test_rcu_pointer);
 220                 debug_yield_read();
 221                 if (local_ptr)
 222                         assert(local_ptr->a == 8);
 223                 if (unlikely(rduration))
 224                         loop_sleep(rduration);
 225                 _rcu_read_unlock();
 226                 nr_reads++;
 227                 /* QS each 1024 reads */
 228                 if (unlikely((nr_reads & ((1 << 10) - 1)) == 0))
 229                         _rcu_quiescent_state();
 230                 if (unlikely(!test_duration_read()))
 231                         break;
 232         }
 233
 234         rcu_unregister_thread();
 235
 236         *count = nr_reads;
 237         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 238                         "reader", pthread_self(), (unsigned long)gettid());
 239         return ((void*)1);
 240
 241 }
 242
 243 void *thr_writer(void *_count)
 244 {
 245         unsigned long long *count = _count;
 246         struct test_array *new, *old;
 247
 248         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 249                         "writer", pthread_self(), (unsigned long)gettid());
 250
 251         set_affinity();
 252
 253         while (!test_go)
 254         {
 255         }
 256         smp_mb();
 257
 258         for (;;) {
 259                 new = test_array_alloc();
 260                 new->a = 8;
 261                 old = _rcu_publish_content(&test_rcu_pointer, new);
 262                 /* can be done after unlock */
 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 }