tests/test_ht.c

   1 /*
   2  * test_ht.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 #include "../urcu-ht.h"
  36
  37 #include "../arch.h"
  38
  39 /* Make this big enough to include the POWER5+ L3 cacheline size of 256B */
  40 #define CACHE_LINE_SIZE 4096
  41
  42 /* hardcoded number of CPUs */
  43 #define NR_CPUS 16384
  44
  45 #if defined(_syscall0)
  46 _syscall0(pid_t, gettid)
  47 #elif defined(__NR_gettid)
  48 static inline pid_t gettid(void)
  49 {
  50         return syscall(__NR_gettid);
  51 }
  52 #else
  53 #warning "use pid as tid"
  54 static inline pid_t gettid(void)
  55 {
  56         return getpid();
  57 }
  58 #endif
  59
  60 #ifndef DYNAMIC_LINK_TEST
  61 #define _LGPL_SOURCE
  62 #else
  63 #define debug_yield_read()
  64 #endif
  65 #include "../urcu.h"
  66
  67 static struct rcu_ht *test_ht;
  68
  69 struct test_array {
  70         int a;
  71 };
  72
  73 static volatile int test_go, test_stop;
  74
  75 static unsigned long wdelay;
  76
  77 static struct test_array *test_rcu_pointer;
  78
  79 static unsigned long duration;
  80
  81 /* read-side C.S. duration, in loops */
  82 static unsigned long rduration;
  83
  84 static inline void loop_sleep(unsigned long l)
  85 {
  86         while(l-- != 0)
  87                 cpu_relax();
  88 }
  89
  90 static int verbose_mode;
  91
  92 #define printf_verbose(fmt, args...)            \
  93         do {                                    \
  94                 if (verbose_mode)               \
  95                         printf(fmt, args);      \
  96         } while (0)
  97
  98 static unsigned int cpu_affinities[NR_CPUS];
  99 static unsigned int next_aff = 0;
 100 static int use_affinity = 0;
 101
 102 pthread_mutex_t affinity_mutex = PTHREAD_MUTEX_INITIALIZER;
 103
 104 static void set_affinity(void)
 105 {
 106         cpu_set_t mask;
 107         int cpu;
 108         int ret;
 109
 110         if (!use_affinity)
 111                 return;
 112
 113         ret = pthread_mutex_lock(&affinity_mutex);
 114         if (ret) {
 115                 perror("Error in pthread mutex lock");
 116                 exit(-1);
 117         }
 118         cpu = cpu_affinities[next_aff++];
 119         ret = pthread_mutex_unlock(&affinity_mutex);
 120         if (ret) {
 121                 perror("Error in pthread mutex unlock");
 122                 exit(-1);
 123         }
 124         CPU_ZERO(&mask);
 125         CPU_SET(cpu, &mask);
 126         sched_setaffinity(0, sizeof(mask), &mask);
 127 }
 128
 129 /*
 130  * returns 0 if test should end.
 131  */
 132 static int test_duration_write(void)
 133 {
 134         return !test_stop;
 135 }
 136
 137 static int test_duration_read(void)
 138 {
 139         return !test_stop;
 140 }
 141
 142 static unsigned long long __thread nr_writes;
 143 static unsigned long long __thread nr_reads;
 144
 145 static unsigned int nr_readers;
 146 static unsigned int nr_writers;
 147
 148 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
 149
 150 void rcu_copy_mutex_lock(void)
 151 {
 152         int ret;
 153         ret = pthread_mutex_lock(&rcu_copy_mutex);
 154         if (ret) {
 155                 perror("Error in pthread mutex lock");
 156                 exit(-1);
 157         }
 158 }
 159
 160 void rcu_copy_mutex_unlock(void)
 161 {
 162         int ret;
 163
 164         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 165         if (ret) {
 166                 perror("Error in pthread mutex unlock");
 167                 exit(-1);
 168         }
 169 }
 170
 171 /*
 172  * malloc/free are reusing memory areas too quickly, which does not let us
 173  * test races appropriately. Use a large circular array for allocations.
 174  * ARRAY_SIZE is larger than nr_writers, which insures we never run over our tail.
 175  */
 176 #define ARRAY_SIZE (1048576 * nr_writers)
 177 #define ARRAY_POISON 0xDEADBEEF
 178 static int array_index;
 179 static struct test_array *test_array;
 180
 181 static struct test_array *test_array_alloc(void)
 182 {
 183         struct test_array *ret;
 184         int index;
 185
 186         rcu_copy_mutex_lock();
 187         index = array_index % ARRAY_SIZE;
 188         assert(test_array[index].a == ARRAY_POISON ||
 189                 test_array[index].a == 0);
 190         ret = &test_array[index];
 191         array_index++;
 192         if (array_index == ARRAY_SIZE)
 193                 array_index = 0;
 194         rcu_copy_mutex_unlock();
 195         return ret;
 196 }
 197
 198 static void test_array_free(struct test_array *ptr)
 199 {
 200         if (!ptr)
 201                 return;
 202         rcu_copy_mutex_lock();
 203         ptr->a = ARRAY_POISON;
 204         rcu_copy_mutex_unlock();
 205 }
 206
 207 void *thr_reader(void *_count)
 208 {
 209         unsigned long long *count = _count;
 210         struct test_array *local_ptr;
 211
 212         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 213                         "reader", pthread_self(), (unsigned long)gettid());
 214
 215         set_affinity();
 216
 217         rcu_register_thread();
 218
 219         while (!test_go)
 220         {
 221         }
 222         smp_mb();
 223
 224         for (;;) {
 225                 rcu_read_lock();
 226                 local_ptr = rcu_dereference(test_rcu_pointer);
 227                 debug_yield_read();
 228                 if (local_ptr)
 229                         assert(local_ptr->a == 8);
 230                 if (unlikely(rduration))
 231                         loop_sleep(rduration);
 232                 rcu_read_unlock();
 233                 nr_reads++;
 234                 if (unlikely(!test_duration_read()))
 235                         break;
 236         }
 237
 238         rcu_unregister_thread();
 239
 240         *count = nr_reads;
 241         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 242                         "reader", pthread_self(), (unsigned long)gettid());
 243         return ((void*)1);
 244
 245 }
 246
 247 void *thr_writer(void *_count)
 248 {
 249         unsigned long long *count = _count;
 250         struct test_array *new, *old;
 251
 252         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 253                         "writer", pthread_self(), (unsigned long)gettid());
 254
 255         set_affinity();
 256
 257         while (!test_go)
 258         {
 259         }
 260         smp_mb();
 261
 262         for (;;) {
 263                 new = test_array_alloc();
 264                 new->a = 8;
 265                 old = rcu_publish_content(&test_rcu_pointer, new);
 266                 if (old)
 267                         old->a = 0;
 268                 test_array_free(old);
 269                 nr_writes++;
 270                 if (unlikely(!test_duration_write()))
 271                         break;
 272                 if (unlikely(wdelay))
 273                         loop_sleep(wdelay);
 274         }
 275
 276         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 277                         "writer", pthread_self(), (unsigned long)gettid());
 278         *count = nr_writes;
 279         return ((void*)2);
 280 }
 281
 282 void show_usage(int argc, char **argv)
 283 {
 284         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 285 #ifdef DEBUG_YIELD
 286         printf(" [-r] [-w] (yield reader and/or writer)");
 287 #endif
 288         printf(" [-d delay] (writer period (us))");
 289         printf(" [-c duration] (reader C.S. duration (in loops))");
 290         printf(" [-v] (verbose output)");
 291         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 292         printf("\n");
 293 }
 294
 295 int main(int argc, char **argv)
 296 {
 297         int err;
 298         pthread_t *tid_reader, *tid_writer;
 299         void *tret;
 300         unsigned long long *count_reader, *count_writer;
 301         unsigned long long tot_reads = 0, tot_writes = 0;
 302         int i, a;
 303
 304         if (argc < 4) {
 305                 show_usage(argc, argv);
 306                 return -1;
 307         }
 308
 309         err = sscanf(argv[1], "%u", &nr_readers);
 310         if (err != 1) {
 311                 show_usage(argc, argv);
 312                 return -1;
 313         }
 314
 315         err = sscanf(argv[2], "%u", &nr_writers);
 316         if (err != 1) {
 317                 show_usage(argc, argv);
 318                 return -1;
 319         }
 320
 321         err = sscanf(argv[3], "%lu", &duration);
 322         if (err != 1) {
 323                 show_usage(argc, argv);
 324                 return -1;
 325         }
 326
 327         for (i = 4; i < argc; i++) {
 328                 if (argv[i][0] != '-')
 329                         continue;
 330                 switch (argv[i][1]) {
 331 #ifdef DEBUG_YIELD
 332                 case 'r':
 333                         yield_active |= YIELD_READ;
 334                         break;
 335                 case 'w':
 336                         yield_active |= YIELD_WRITE;
 337                         break;
 338 #endif
 339                 case 'a':
 340                         if (argc < i + 2) {
 341                                 show_usage(argc, argv);
 342                                 return -1;
 343                         }
 344                         a = atoi(argv[++i]);
 345                         cpu_affinities[next_aff++] = a;
 346                         use_affinity = 1;
 347                         printf_verbose("Adding CPU %d affinity\n", a);
 348                         break;
 349                 case 'c':
 350                         if (argc < i + 2) {
 351                                 show_usage(argc, argv);
 352                                 return -1;
 353                         }
 354                         rduration = atol(argv[++i]);
 355                         break;
 356                 case 'd':
 357                         if (argc < i + 2) {
 358                                 show_usage(argc, argv);
 359                                 return -1;
 360                         }
 361                         wdelay = atol(argv[++i]);
 362                         break;
 363                 case 'v':
 364                         verbose_mode = 1;
 365                         break;
 366                 }
 367         }
 368
 369         printf_verbose("running test for %lu seconds, %u readers, %u writers.\n",
 370                 duration, nr_readers, nr_writers);
 371         printf_verbose("Writer delay : %lu loops.\n", wdelay);
 372         printf_verbose("Reader duration : %lu loops.\n", rduration);
 373         printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
 374                         "main", pthread_self(), (unsigned long)gettid());
 375
 376         test_array = malloc(sizeof(*test_array) * ARRAY_SIZE);
 377         tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
 378         tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
 379         count_reader = malloc(sizeof(*count_reader) * nr_readers);
 380         count_writer = malloc(sizeof(*count_writer) * nr_writers);
 381         test_ht = ht_new(stupid_hash, free);
 382         next_aff = 0;
 383
 384         for (i = 0; i < nr_readers; i++) {
 385                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 386                                      &count_reader[i]);
 387                 if (err != 0)
 388                         exit(1);
 389         }
 390         for (i = 0; i < nr_writers; i++) {
 391                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 392                                      &count_writer[i]);
 393                 if (err != 0)
 394                         exit(1);
 395         }
 396
 397         smp_mb();
 398
 399         test_go = 1;
 400
 401         sleep(duration);
 402
 403         test_stop = 1;
 404
 405         for (i = 0; i < nr_readers; i++) {
 406                 err = pthread_join(tid_reader[i], &tret);
 407                 if (err != 0)
 408                         exit(1);
 409                 tot_reads += count_reader[i];
 410         }
 411         for (i = 0; i < nr_writers; i++) {
 412                 err = pthread_join(tid_writer[i], &tret);
 413                 if (err != 0)
 414                         exit(1);
 415                 tot_writes += count_writer[i];
 416         }
 417         ht_destroy(test_ht);
 418
 419         printf_verbose("total number of reads : %llu, writes %llu\n", tot_reads,
 420                tot_writes);
 421         printf("SUMMARY %-25s testdur %4lu nr_readers %3u rdur %6lu "
 422                 "nr_writers %3u "
 423                 "wdelay %6lu nr_reads %12llu nr_writes %12llu nr_ops %12llu\n",
 424                 argv[0], duration, nr_readers, rduration,
 425                 nr_writers, wdelay, tot_reads, tot_writes,
 426                 tot_reads + tot_writes);
 427         test_array_free(test_rcu_pointer);
 428         free(test_array);
 429         free(tid_reader);
 430         free(tid_writer);
 431         free(count_reader);
 432         free(count_writer);
 433         return 0;
 434 }