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 #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 #define _LGPL_SOURCE
  57 #include "urcu-qsbr.h"
  58
  59 struct test_array {
  60         int a;
  61 };
  62
  63 static volatile int test_go, test_stop;
  64
  65 static unsigned long wdelay;
  66
  67 static struct test_array *test_rcu_pointer;
  68
  69 static unsigned long duration;
  70
  71 /* read-side C.S. duration, in loops */
  72 static unsigned long rduration;
  73
  74 static inline void loop_sleep(unsigned long l)
  75 {
  76         while(l-- != 0)
  77                 cpu_relax();
  78 }
  79
  80 static int verbose_mode;
  81
  82 #define printf_verbose(fmt, args...)            \
  83         do {                                    \
  84                 if (verbose_mode)               \
  85                         printf(fmt, args);      \
  86         } while (0)
  87
  88 /*
  89  * returns 0 if test should end.
  90  */
  91 static int test_duration_write(void)
  92 {
  93         return !test_stop;
  94 }
  95
  96 static int test_duration_read(void)
  97 {
  98         return !test_stop;
  99 }
 100
 101 static unsigned long long __thread nr_writes;
 102 static unsigned long long __thread nr_reads;
 103
 104 static unsigned int nr_readers;
 105 static unsigned int nr_writers;
 106
 107 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
 108
 109 void rcu_copy_mutex_lock(void)
 110 {
 111         int ret;
 112         ret = pthread_mutex_lock(&rcu_copy_mutex);
 113         if (ret) {
 114                 perror("Error in pthread mutex lock");
 115                 exit(-1);
 116         }
 117 }
 118
 119 void rcu_copy_mutex_unlock(void)
 120 {
 121         int ret;
 122
 123         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 124         if (ret) {
 125                 perror("Error in pthread mutex unlock");
 126                 exit(-1);
 127         }
 128 }
 129
 130 /*
 131  * malloc/free are reusing memory areas too quickly, which does not let us
 132  * test races appropriately. Use a large circular array for allocations.
 133  * ARRAY_SIZE is larger than nr_writers, which insures we never run over our tail.
 134  */
 135 #define ARRAY_SIZE (1048576 * nr_writers)
 136 #define ARRAY_POISON 0xDEADBEEF
 137 static int array_index;
 138 static struct test_array *test_array;
 139
 140 static struct test_array *test_array_alloc(void)
 141 {
 142         struct test_array *ret;
 143         int index;
 144
 145         rcu_copy_mutex_lock();
 146         index = array_index % ARRAY_SIZE;
 147         assert(test_array[index].a == ARRAY_POISON ||
 148                 test_array[index].a == 0);
 149         ret = &test_array[index];
 150         array_index++;
 151         if (array_index == ARRAY_SIZE)
 152                 array_index = 0;
 153         rcu_copy_mutex_unlock();
 154         return ret;
 155 }
 156
 157 static void test_array_free(struct test_array *ptr)
 158 {
 159         if (!ptr)
 160                 return;
 161         rcu_copy_mutex_lock();
 162         ptr->a = ARRAY_POISON;
 163         rcu_copy_mutex_unlock();
 164 }
 165
 166 void *thr_reader(void *_count)
 167 {
 168         unsigned long long *count = _count;
 169         struct test_array *local_ptr;
 170
 171         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 172                         "reader", pthread_self(), (unsigned long)gettid());
 173
 174         rcu_register_thread();
 175
 176         while (!test_go)
 177         {
 178         }
 179         smp_mb();
 180
 181         for (;;) {
 182                 _rcu_read_lock();
 183                 local_ptr = _rcu_dereference(test_rcu_pointer);
 184                 debug_yield_read();
 185                 if (local_ptr)
 186                         assert(local_ptr->a == 8);
 187                 if (unlikely(rduration))
 188                         loop_sleep(rduration);
 189                 _rcu_read_unlock();
 190                 nr_reads++;
 191                 /* QS each 1024 reads */
 192                 if (unlikely((nr_reads & ((1 << 10) - 1)) == 0))
 193                         _rcu_quiescent_state();
 194                 if (unlikely(!test_duration_read()))
 195                         break;
 196         }
 197
 198         rcu_unregister_thread();
 199
 200         *count = nr_reads;
 201         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 202                         "reader", pthread_self(), (unsigned long)gettid());
 203         return ((void*)1);
 204
 205 }
 206
 207 void *thr_writer(void *_count)
 208 {
 209         unsigned long long *count = _count;
 210         struct test_array *new, *old;
 211
 212         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 213                         "writer", pthread_self(), (unsigned long)gettid());
 214
 215         while (!test_go)
 216         {
 217         }
 218         smp_mb();
 219
 220         for (;;) {
 221                 new = test_array_alloc();
 222                 rcu_copy_mutex_lock();
 223                 old = test_rcu_pointer;
 224                 if (old)
 225                         assert(old->a == 8);
 226                 new->a = 8;
 227                 old = _rcu_publish_content(&test_rcu_pointer, new);
 228                 rcu_copy_mutex_unlock();
 229                 /* can be done after unlock */
 230                 if (old)
 231                         old->a = 0;
 232                 test_array_free(old);
 233                 nr_writes++;
 234                 if (unlikely(!test_duration_write()))
 235                         break;
 236                 if (unlikely(wdelay))
 237                         loop_sleep(wdelay);
 238         }
 239
 240         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 241                         "writer", pthread_self(), (unsigned long)gettid());
 242         *count = nr_writes;
 243         return ((void*)2);
 244 }
 245
 246 void show_usage(int argc, char **argv)
 247 {
 248         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 249 #ifdef DEBUG_YIELD
 250         printf(" [-r] [-w] (yield reader and/or writer)");
 251 #endif
 252         printf(" [-d delay] (writer period (us))");
 253         printf(" [-c duration] (reader C.S. duration (in loops))");
 254         printf(" [-v] (verbose output)");
 255         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 256         printf("\n");
 257 }
 258
 259 cpu_set_t affinity;
 260
 261 int main(int argc, char **argv)
 262 {
 263         int err;
 264         pthread_t *tid_reader, *tid_writer;
 265         void *tret;
 266         unsigned long long *count_reader, *count_writer;
 267         unsigned long long tot_reads = 0, tot_writes = 0;
 268         int i, a;
 269         int use_affinity = 0;
 270
 271         if (argc < 4) {
 272                 show_usage(argc, argv);
 273                 return -1;
 274         }
 275
 276         err = sscanf(argv[1], "%u", &nr_readers);
 277         if (err != 1) {
 278                 show_usage(argc, argv);
 279                 return -1;
 280         }
 281
 282         err = sscanf(argv[2], "%u", &nr_writers);
 283         if (err != 1) {
 284                 show_usage(argc, argv);
 285                 return -1;
 286         }
 287
 288         err = sscanf(argv[3], "%lu", &duration);
 289         if (err != 1) {
 290                 show_usage(argc, argv);
 291                 return -1;
 292         }
 293
 294         CPU_ZERO(&affinity);
 295
 296         for (i = 4; i < argc; i++) {
 297                 if (argv[i][0] != '-')
 298                         continue;
 299                 switch (argv[i][1]) {
 300 #ifdef DEBUG_YIELD
 301                 case 'r':
 302                         yield_active |= YIELD_READ;
 303                         break;
 304                 case 'w':
 305                         yield_active |= YIELD_WRITE;
 306                         break;
 307 #endif
 308                 case 'a':
 309                         if (argc < i + 2) {
 310                                 show_usage(argc, argv);
 311                                 return -1;
 312                         }
 313                         a = atoi(argv[++i]);
 314                         CPU_SET(a, &affinity);
 315                         use_affinity = 1;
 316                         printf_verbose("Adding CPU %d affinity\n", a);
 317                         break;
 318                 case 'c':
 319                         if (argc < i + 2) {
 320                                 show_usage(argc, argv);
 321                                 return -1;
 322                         }
 323                         rduration = atol(argv[++i]);
 324                         break;
 325                 case 'd':
 326                         if (argc < i + 2) {
 327                                 show_usage(argc, argv);
 328                                 return -1;
 329                         }
 330                         wdelay = atol(argv[++i]);
 331                         break;
 332                 case 'v':
 333                         verbose_mode = 1;
 334                         break;
 335                 }
 336         }
 337
 338         printf_verbose("running test for %lu seconds, %u readers, %u writers.\n",
 339                 duration, nr_readers, nr_writers);
 340         printf_verbose("Writer delay : %lu loops.\n", wdelay);
 341         printf_verbose("Reader duration : %lu loops.\n", rduration);
 342         printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
 343                         "main", pthread_self(), (unsigned long)gettid());
 344
 345         if (use_affinity
 346             && sched_setaffinity(0, sizeof(affinity), &affinity) < 0) {
 347                 perror("sched_setaffinity");
 348                 exit(-1);
 349         }
 350
 351         test_array = malloc(sizeof(*test_array) * ARRAY_SIZE);
 352         tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
 353         tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
 354         count_reader = malloc(sizeof(*count_reader) * nr_readers);
 355         count_writer = malloc(sizeof(*count_writer) * nr_writers);
 356
 357         for (i = 0; i < nr_readers; i++) {
 358                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 359                                      &count_reader[i]);
 360                 if (err != 0)
 361                         exit(1);
 362         }
 363         for (i = 0; i < nr_writers; i++) {
 364                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 365                                      &count_writer[i]);
 366                 if (err != 0)
 367                         exit(1);
 368         }
 369
 370         smp_mb();
 371
 372         test_go = 1;
 373
 374         sleep(duration);
 375
 376         test_stop = 1;
 377
 378         for (i = 0; i < nr_readers; i++) {
 379                 err = pthread_join(tid_reader[i], &tret);
 380                 if (err != 0)
 381                         exit(1);
 382                 tot_reads += count_reader[i];
 383         }
 384         for (i = 0; i < nr_writers; i++) {
 385                 err = pthread_join(tid_writer[i], &tret);
 386                 if (err != 0)
 387                         exit(1);
 388                 tot_writes += count_writer[i];
 389         }
 390
 391         printf_verbose("total number of reads : %llu, writes %llu\n", tot_reads,
 392                tot_writes);
 393         printf("SUMMARY %-25s testdur %4lu nr_readers %3u rdur %6lu "
 394                 "nr_writers %3u "
 395                 "wdelay %6lu nr_reads %12llu nr_writes %12llu nr_ops %12llu\n",
 396                 argv[0], duration, nr_readers, rduration,
 397                 nr_writers, wdelay, tot_reads, tot_writes,
 398                 tot_reads + tot_writes);
 399         test_array_free(test_rcu_pointer);
 400         free(test_array);
 401         free(tid_reader);
 402         free(tid_writer);
 403         free(count_reader);
 404         free(count_writer);
 405         return 0;
 406 }