tests/test_urcu_gc.c

   1 /*
   2  * test_urcu_gc.c
   3  *
   4  * Userspace RCU library - test program (with baatch reclamation)
   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.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 int reclaim_batch = 1;
  76
  77 struct reclaim_queue {
  78         void **queue;   /* Beginning of queue */
  79         void **head;    /* Insert position */
  80 };
  81
  82 static struct reclaim_queue *pending_reclaims;
  83
  84 static unsigned long duration;
  85
  86 /* read-side C.S. duration, in loops */
  87 static unsigned long rduration;
  88
  89 static inline void loop_sleep(unsigned long l)
  90 {
  91         while(l-- != 0)
  92                 cpu_relax();
  93 }
  94
  95 static int verbose_mode;
  96
  97 #define printf_verbose(fmt, args...)            \
  98         do {                                    \
  99                 if (verbose_mode)               \
 100                         printf(fmt, args);      \
 101         } while (0)
 102
 103 static unsigned int cpu_affinities[NR_CPUS];
 104 static unsigned int next_aff = 0;
 105 static int use_affinity = 0;
 106
 107 pthread_mutex_t affinity_mutex = PTHREAD_MUTEX_INITIALIZER;
 108
 109 #ifndef HAVE_CPU_SET_T
 110 typedef unsigned long cpu_set_t;
 111 # define CPU_ZERO(cpuset) do { *(cpuset) = 0; } while(0)
 112 # define CPU_SET(cpu, cpuset) do { *(cpuset) |= (1UL << (cpu)); } while(0)
 113 #endif
 114
 115 static void set_affinity(void)
 116 {
 117         cpu_set_t mask;
 118         int cpu;
 119         int ret;
 120
 121         if (!use_affinity)
 122                 return;
 123
 124 #if HAVE_SCHED_SETAFFINITY
 125         ret = pthread_mutex_lock(&affinity_mutex);
 126         if (ret) {
 127                 perror("Error in pthread mutex lock");
 128                 exit(-1);
 129         }
 130         cpu = cpu_affinities[next_aff++];
 131         ret = pthread_mutex_unlock(&affinity_mutex);
 132         if (ret) {
 133                 perror("Error in pthread mutex unlock");
 134                 exit(-1);
 135         }
 136
 137         CPU_ZERO(&mask);
 138         CPU_SET(cpu, &mask);
 139 #if SCHED_SETAFFINITY_ARGS == 2
 140         sched_setaffinity(0, &mask);
 141 #else
 142         sched_setaffinity(0, sizeof(mask), &mask);
 143 #endif
 144 #endif /* HAVE_SCHED_SETAFFINITY */
 145 }
 146
 147 /*
 148  * returns 0 if test should end.
 149  */
 150 static int test_duration_write(void)
 151 {
 152         return !test_stop;
 153 }
 154
 155 static int test_duration_read(void)
 156 {
 157         return !test_stop;
 158 }
 159
 160 static unsigned long long __thread nr_writes;
 161 static unsigned long long __thread nr_reads;
 162
 163 static
 164 unsigned long long __attribute__((aligned(CACHE_LINE_SIZE))) *tot_nr_writes;
 165
 166 static unsigned int nr_readers;
 167 static unsigned int nr_writers;
 168
 169 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
 170
 171 void rcu_copy_mutex_lock(void)
 172 {
 173         int ret;
 174         ret = pthread_mutex_lock(&rcu_copy_mutex);
 175         if (ret) {
 176                 perror("Error in pthread mutex lock");
 177                 exit(-1);
 178         }
 179 }
 180
 181 void rcu_copy_mutex_unlock(void)
 182 {
 183         int ret;
 184
 185         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 186         if (ret) {
 187                 perror("Error in pthread mutex unlock");
 188                 exit(-1);
 189         }
 190 }
 191
 192 void *thr_reader(void *_count)
 193 {
 194         unsigned long long *count = _count;
 195         struct test_array *local_ptr;
 196
 197         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 198                         "reader", pthread_self(), (unsigned long)gettid());
 199
 200         set_affinity();
 201
 202         rcu_register_thread();
 203
 204         while (!test_go)
 205         {
 206         }
 207         smp_mb();
 208
 209         for (;;) {
 210                 rcu_read_lock();
 211                 local_ptr = rcu_dereference(test_rcu_pointer);
 212                 debug_yield_read();
 213                 if (local_ptr)
 214                         assert(local_ptr->a == 8);
 215                 if (unlikely(rduration))
 216                         loop_sleep(rduration);
 217                 rcu_read_unlock();
 218                 nr_reads++;
 219                 if (unlikely(!test_duration_read()))
 220                         break;
 221         }
 222
 223         rcu_unregister_thread();
 224
 225         *count = nr_reads;
 226         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 227                         "reader", pthread_self(), (unsigned long)gettid());
 228         return ((void*)1);
 229
 230 }
 231
 232 static void rcu_gc_clear_queue(unsigned long wtidx)
 233 {
 234         void **p;
 235
 236         /* Wait for Q.S and empty queue */
 237         synchronize_rcu();
 238
 239         for (p = pending_reclaims[wtidx].queue;
 240                         p < pending_reclaims[wtidx].head; p++) {
 241                 /* poison */
 242                 if (*p)
 243                         ((struct test_array *)*p)->a = 0;
 244                 free(*p);
 245         }
 246         pending_reclaims[wtidx].head = pending_reclaims[wtidx].queue;
 247 }
 248
 249 /* Using per-thread queue */
 250 static void rcu_gc_reclaim(unsigned long wtidx, void *old)
 251 {
 252         /* Queue pointer */
 253         *pending_reclaims[wtidx].head = old;
 254         pending_reclaims[wtidx].head++;
 255
 256         if (likely(pending_reclaims[wtidx].head - pending_reclaims[wtidx].queue
 257                         < reclaim_batch))
 258                 return;
 259
 260         rcu_gc_clear_queue(wtidx);
 261 }
 262
 263 void *thr_writer(void *data)
 264 {
 265         unsigned long wtidx = (unsigned long)data;
 266 #ifdef TEST_LOCAL_GC
 267         struct test_array *old = NULL;
 268 #else
 269         struct test_array *new, *old;
 270 #endif
 271
 272         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 273                         "writer", pthread_self(), (unsigned long)gettid());
 274
 275         set_affinity();
 276
 277         while (!test_go)
 278         {
 279         }
 280         smp_mb();
 281
 282         for (;;) {
 283 #ifndef TEST_LOCAL_GC
 284                 new = malloc(sizeof(*new));
 285                 new->a = 8;
 286                 old = rcu_xchg_pointer(&test_rcu_pointer, new);
 287 #endif
 288                 rcu_gc_reclaim(wtidx, old);
 289                 nr_writes++;
 290                 if (unlikely(!test_duration_write()))
 291                         break;
 292                 if (unlikely(wdelay))
 293                         loop_sleep(wdelay);
 294         }
 295
 296         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 297                         "writer", pthread_self(), (unsigned long)gettid());
 298         tot_nr_writes[wtidx] = nr_writes;
 299         return ((void*)2);
 300 }
 301
 302 void show_usage(int argc, char **argv)
 303 {
 304         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 305 #ifdef DEBUG_YIELD
 306         printf(" [-r] [-w] (yield reader and/or writer)");
 307 #endif
 308         printf(" [-d delay] (writer period (us))");
 309         printf(" [-c duration] (reader C.S. duration (in loops))");
 310         printf(" [-v] (verbose output)");
 311         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 312         printf("\n");
 313 }
 314
 315 int main(int argc, char **argv)
 316 {
 317         int err;
 318         pthread_t *tid_reader, *tid_writer;
 319         void *tret;
 320         unsigned long long *count_reader;
 321         unsigned long long tot_reads = 0, tot_writes = 0;
 322         int i, a;
 323
 324         if (argc < 4) {
 325                 show_usage(argc, argv);
 326                 return -1;
 327         }
 328
 329         err = sscanf(argv[1], "%u", &nr_readers);
 330         if (err != 1) {
 331                 show_usage(argc, argv);
 332                 return -1;
 333         }
 334
 335         err = sscanf(argv[2], "%u", &nr_writers);
 336         if (err != 1) {
 337                 show_usage(argc, argv);
 338                 return -1;
 339         }
 340
 341         err = sscanf(argv[3], "%lu", &duration);
 342         if (err != 1) {
 343                 show_usage(argc, argv);
 344                 return -1;
 345         }
 346
 347         for (i = 4; i < argc; i++) {
 348                 if (argv[i][0] != '-')
 349                         continue;
 350                 switch (argv[i][1]) {
 351 #ifdef DEBUG_YIELD
 352                 case 'r':
 353                         yield_active |= YIELD_READ;
 354                         break;
 355                 case 'w':
 356                         yield_active |= YIELD_WRITE;
 357                         break;
 358 #endif
 359                 case 'a':
 360                         if (argc < i + 2) {
 361                                 show_usage(argc, argv);
 362                                 return -1;
 363                         }
 364                         a = atoi(argv[++i]);
 365                         cpu_affinities[next_aff++] = a;
 366                         use_affinity = 1;
 367                         printf_verbose("Adding CPU %d affinity\n", a);
 368                         break;
 369                 case 'b':
 370                         if (argc < i + 2) {
 371                                 show_usage(argc, argv);
 372                                 return -1;
 373                         }
 374                         reclaim_batch = atol(argv[++i]);
 375                         break;
 376                 case 'c':
 377                         if (argc < i + 2) {
 378                                 show_usage(argc, argv);
 379                                 return -1;
 380                         }
 381                         rduration = atol(argv[++i]);
 382                         break;
 383                 case 'd':
 384                         if (argc < i + 2) {
 385                                 show_usage(argc, argv);
 386                                 return -1;
 387                         }
 388                         wdelay = atol(argv[++i]);
 389                         break;
 390                 case 'v':
 391                         verbose_mode = 1;
 392                         break;
 393                 }
 394         }
 395
 396         printf_verbose("running test for %lu seconds, %u readers, %u writers.\n",
 397                 duration, nr_readers, nr_writers);
 398         printf_verbose("Writer delay : %lu loops.\n", wdelay);
 399         printf_verbose("Reader duration : %lu loops.\n", rduration);
 400         printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
 401                         "main", pthread_self(), (unsigned long)gettid());
 402
 403         tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
 404         tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
 405         count_reader = malloc(sizeof(*count_reader) * nr_readers);
 406         tot_nr_writes = malloc(sizeof(*tot_nr_writes) * nr_writers);
 407         pending_reclaims = malloc(sizeof(*pending_reclaims) * nr_writers);
 408         if (reclaim_batch * sizeof(*pending_reclaims[i].queue)
 409                         < CACHE_LINE_SIZE)
 410                 for (i = 0; i < nr_writers; i++)
 411                         pending_reclaims[i].queue = calloc(1, CACHE_LINE_SIZE);
 412         else
 413                 for (i = 0; i < nr_writers; i++)
 414                         pending_reclaims[i].queue = calloc(reclaim_batch,
 415                                         sizeof(*pending_reclaims[i].queue));
 416         for (i = 0; i < nr_writers; i++)
 417                 pending_reclaims[i].head = pending_reclaims[i].queue;
 418
 419         next_aff = 0;
 420
 421         for (i = 0; i < nr_readers; i++) {
 422                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 423                                      &count_reader[i]);
 424                 if (err != 0)
 425                         exit(1);
 426         }
 427         for (i = 0; i < nr_writers; i++) {
 428                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 429                                      (void *)(long)i);
 430                 if (err != 0)
 431                         exit(1);
 432         }
 433
 434         smp_mb();
 435
 436         test_go = 1;
 437
 438         sleep(duration);
 439
 440         test_stop = 1;
 441
 442         for (i = 0; i < nr_readers; i++) {
 443                 err = pthread_join(tid_reader[i], &tret);
 444                 if (err != 0)
 445                         exit(1);
 446                 tot_reads += count_reader[i];
 447         }
 448         for (i = 0; i < nr_writers; i++) {
 449                 err = pthread_join(tid_writer[i], &tret);
 450                 if (err != 0)
 451                         exit(1);
 452                 tot_writes += tot_nr_writes[i];
 453                 rcu_gc_clear_queue(i);
 454         }
 455
 456         printf_verbose("total number of reads : %llu, writes %llu\n", tot_reads,
 457                tot_writes);
 458         printf("SUMMARY %-25s testdur %4lu nr_readers %3u rdur %6lu "
 459                 "nr_writers %3u "
 460                 "wdelay %6lu nr_reads %12llu nr_writes %12llu nr_ops %12llu "
 461                 "batch %u\n",
 462                 argv[0], duration, nr_readers, rduration,
 463                 nr_writers, wdelay, tot_reads, tot_writes,
 464                 tot_reads + tot_writes, reclaim_batch);
 465         free(tid_reader);
 466         free(tid_writer);
 467         free(count_reader);
 468         free(tot_nr_writes);
 469         for (i = 0; i < nr_writers; i++)
 470                 free(pending_reclaims[i].queue);
 471         free(pending_reclaims);
 472
 473         return 0;
 474 }