tests/test_qsbr_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@efficios.com>
   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 #define _LGPL_SOURCE
  59 #include <urcu-qsbr.h>
  60
  61 struct test_array {
  62         int a;
  63 };
  64
  65 static volatile int test_go, test_stop;
  66
  67 static unsigned long wdelay;
  68
  69 static struct test_array *test_rcu_pointer;
  70
  71 static unsigned long duration;
  72
  73 /* read-side C.S. duration, in loops */
  74 static unsigned long rduration;
  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
  85 /* write-side C.S. duration, in loops */
  86 static unsigned long wduration;
  87
  88 static inline void loop_sleep(unsigned long l)
  89 {
  90         while(l-- != 0)
  91                 cpu_relax();
  92 }
  93
  94 static int verbose_mode;
  95
  96 #define printf_verbose(fmt, args...)            \
  97         do {                                    \
  98                 if (verbose_mode)               \
  99                         printf(fmt, args);      \
 100         } while (0)
 101
 102 static unsigned int cpu_affinities[NR_CPUS];
 103 static unsigned int next_aff = 0;
 104 static int use_affinity = 0;
 105
 106 pthread_mutex_t affinity_mutex = PTHREAD_MUTEX_INITIALIZER;
 107
 108 #ifndef HAVE_CPU_SET_T
 109 typedef unsigned long cpu_set_t;
 110 # define CPU_ZERO(cpuset) do { *(cpuset) = 0; } while(0)
 111 # define CPU_SET(cpu, cpuset) do { *(cpuset) |= (1UL << (cpu)); } while(0)
 112 #endif
 113
 114 static void set_affinity(void)
 115 {
 116         cpu_set_t mask;
 117         int cpu;
 118         int ret;
 119
 120         if (!use_affinity)
 121                 return;
 122
 123 #if HAVE_SCHED_SETAFFINITY
 124         ret = pthread_mutex_lock(&affinity_mutex);
 125         if (ret) {
 126                 perror("Error in pthread mutex lock");
 127                 exit(-1);
 128         }
 129         cpu = cpu_affinities[next_aff++];
 130         ret = pthread_mutex_unlock(&affinity_mutex);
 131         if (ret) {
 132                 perror("Error in pthread mutex unlock");
 133                 exit(-1);
 134         }
 135
 136         CPU_ZERO(&mask);
 137         CPU_SET(cpu, &mask);
 138 #if SCHED_SETAFFINITY_ARGS == 2
 139         sched_setaffinity(0, &mask);
 140 #else
 141         sched_setaffinity(0, sizeof(mask), &mask);
 142 #endif
 143 #endif /* HAVE_SCHED_SETAFFINITY */
 144 }
 145
 146 /*
 147  * returns 0 if test should end.
 148  */
 149 static int test_duration_write(void)
 150 {
 151         return !test_stop;
 152 }
 153
 154 static int test_duration_read(void)
 155 {
 156         return !test_stop;
 157 }
 158
 159 static unsigned long long __thread nr_writes;
 160 static unsigned long long __thread nr_reads;
 161
 162 static unsigned int nr_readers;
 163 static unsigned int nr_writers;
 164
 165 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
 166 static
 167 unsigned long long __attribute__((aligned(CACHE_LINE_SIZE))) *tot_nr_writes;
 168
 169
 170 void rcu_copy_mutex_lock(void)
 171 {
 172         int ret;
 173         ret = pthread_mutex_lock(&rcu_copy_mutex);
 174         if (ret) {
 175                 perror("Error in pthread mutex lock");
 176                 exit(-1);
 177         }
 178 }
 179
 180 void rcu_copy_mutex_unlock(void)
 181 {
 182         int ret;
 183
 184         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 185         if (ret) {
 186                 perror("Error in pthread mutex unlock");
 187                 exit(-1);
 188         }
 189 }
 190
 191 void *thr_reader(void *_count)
 192 {
 193         unsigned long long *count = _count;
 194         struct test_array *local_ptr;
 195
 196         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 197                         "reader", pthread_self(), (unsigned long)gettid());
 198
 199         set_affinity();
 200
 201         rcu_register_thread();
 202
 203         while (!test_go)
 204         {
 205         }
 206         smp_mb();
 207
 208         for (;;) {
 209                 _rcu_read_lock();
 210                 local_ptr = _rcu_dereference(test_rcu_pointer);
 211                 debug_yield_read();
 212                 if (local_ptr)
 213                         assert(local_ptr->a == 8);
 214                 if (unlikely(rduration))
 215                         loop_sleep(rduration);
 216                 _rcu_read_unlock();
 217                 nr_reads++;
 218                 /* QS each 1024 reads */
 219                 if (unlikely((nr_reads & ((1 << 10) - 1)) == 0))
 220                         _rcu_quiescent_state();
 221                 if (unlikely(!test_duration_read()))
 222                         break;
 223         }
 224
 225         rcu_unregister_thread();
 226
 227         *count = nr_reads;
 228         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 229                         "reader", pthread_self(), (unsigned long)gettid());
 230         return ((void*)1);
 231
 232 }
 233
 234 static void rcu_gc_clear_queue(unsigned long wtidx)
 235 {
 236         void **p;
 237
 238         /* Wait for Q.S and empty queue */
 239         synchronize_rcu();
 240
 241         for (p = pending_reclaims[wtidx].queue;
 242                         p < pending_reclaims[wtidx].head; p++) {
 243                 /* poison */
 244                 if (*p)
 245                         ((struct test_array *)*p)->a = 0;
 246                 free(*p);
 247         }
 248         pending_reclaims[wtidx].head = pending_reclaims[wtidx].queue;
 249 }
 250
 251 /* Using per-thread queue */
 252 static void rcu_gc_reclaim(unsigned long wtidx, void *old)
 253 {
 254         /* Queue pointer */
 255         *pending_reclaims[wtidx].head = old;
 256         pending_reclaims[wtidx].head++;
 257
 258         if (likely(pending_reclaims[wtidx].head - pending_reclaims[wtidx].queue
 259                         < reclaim_batch))
 260                 return;
 261
 262         rcu_gc_clear_queue(wtidx);
 263 }
 264
 265 void *thr_writer(void *data)
 266 {
 267         unsigned long wtidx = (unsigned long)data;
 268 #ifdef TEST_LOCAL_GC
 269         struct test_array *old = NULL;
 270 #else
 271         struct test_array *new, *old;
 272 #endif
 273
 274         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 275                         "writer", pthread_self(), (unsigned long)gettid());
 276
 277         set_affinity();
 278
 279         while (!test_go)
 280         {
 281         }
 282         smp_mb();
 283
 284         for (;;) {
 285 #ifndef TEST_LOCAL_GC
 286                 new = malloc(sizeof(*new));
 287                 new->a = 8;
 288                 old = _rcu_xchg_pointer(&test_rcu_pointer, new);
 289 #endif
 290                 if (unlikely(wduration))
 291                         loop_sleep(wduration);
 292                 rcu_gc_reclaim(wtidx, old);
 293                 nr_writes++;
 294                 if (unlikely(!test_duration_write()))
 295                         break;
 296                 if (unlikely(wdelay))
 297                         loop_sleep(wdelay);
 298         }
 299
 300         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 301                         "writer", pthread_self(), (unsigned long)gettid());
 302         tot_nr_writes[wtidx] = nr_writes;
 303         return ((void*)2);
 304 }
 305
 306 void show_usage(int argc, char **argv)
 307 {
 308         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 309 #ifdef DEBUG_YIELD
 310         printf(" [-r] [-w] (yield reader and/or writer)");
 311 #endif
 312         printf(" [-b batch] (batch reclaim)");
 313         printf(" [-d delay] (writer period (us))");
 314         printf(" [-c duration] (reader C.S. duration (in loops))");
 315         printf(" [-e duration] (writer C.S. duration (in loops))");
 316         printf(" [-v] (verbose output)");
 317         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 318         printf("\n");
 319 }
 320
 321 int main(int argc, char **argv)
 322 {
 323         int err;
 324         pthread_t *tid_reader, *tid_writer;
 325         void *tret;
 326         unsigned long long *count_reader;
 327         unsigned long long tot_reads = 0, tot_writes = 0;
 328         int i, a;
 329
 330         if (argc < 4) {
 331                 show_usage(argc, argv);
 332                 return -1;
 333         }
 334
 335         err = sscanf(argv[1], "%u", &nr_readers);
 336         if (err != 1) {
 337                 show_usage(argc, argv);
 338                 return -1;
 339         }
 340
 341         err = sscanf(argv[2], "%u", &nr_writers);
 342         if (err != 1) {
 343                 show_usage(argc, argv);
 344                 return -1;
 345         }
 346
 347         err = sscanf(argv[3], "%lu", &duration);
 348         if (err != 1) {
 349                 show_usage(argc, argv);
 350                 return -1;
 351         }
 352
 353         for (i = 4; i < argc; i++) {
 354                 if (argv[i][0] != '-')
 355                         continue;
 356                 switch (argv[i][1]) {
 357 #ifdef DEBUG_YIELD
 358                 case 'r':
 359                         yield_active |= YIELD_READ;
 360                         break;
 361                 case 'w':
 362                         yield_active |= YIELD_WRITE;
 363                         break;
 364 #endif
 365                 case 'a':
 366                         if (argc < i + 2) {
 367                                 show_usage(argc, argv);
 368                                 return -1;
 369                         }
 370                         a = atoi(argv[++i]);
 371                         cpu_affinities[next_aff++] = a;
 372                         use_affinity = 1;
 373                         printf_verbose("Adding CPU %d affinity\n", a);
 374                         break;
 375                 case 'b':
 376                         if (argc < i + 2) {
 377                                 show_usage(argc, argv);
 378                                 return -1;
 379                         }
 380                         reclaim_batch = atol(argv[++i]);
 381                         break;
 382                 case 'c':
 383                         if (argc < i + 2) {
 384                                 show_usage(argc, argv);
 385                                 return -1;
 386                         }
 387                         rduration = atol(argv[++i]);
 388                         break;
 389                 case 'd':
 390                         if (argc < i + 2) {
 391                                 show_usage(argc, argv);
 392                                 return -1;
 393                         }
 394                         wdelay = atol(argv[++i]);
 395                         break;
 396                 case 'e':
 397                         if (argc < i + 2) {
 398                                 show_usage(argc, argv);
 399                                 return -1;
 400                         }
 401                         wduration = atol(argv[++i]);
 402                         break;
 403                 case 'v':
 404                         verbose_mode = 1;
 405                         break;
 406                 }
 407         }
 408
 409         printf_verbose("running test for %lu seconds, %u readers, %u writers.\n",
 410                 duration, nr_readers, nr_writers);
 411         printf_verbose("Writer delay : %lu loops.\n", wdelay);
 412         printf_verbose("Reader duration : %lu loops.\n", rduration);
 413         printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
 414                         "main", pthread_self(), (unsigned long)gettid());
 415
 416         tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
 417         tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
 418         count_reader = malloc(sizeof(*count_reader) * nr_readers);
 419         tot_nr_writes = malloc(sizeof(*tot_nr_writes) * nr_writers);
 420         pending_reclaims = malloc(sizeof(*pending_reclaims) * nr_writers);
 421         if (reclaim_batch * sizeof(*pending_reclaims[i].queue)
 422                         < CACHE_LINE_SIZE)
 423                 for (i = 0; i < nr_writers; i++)
 424                         pending_reclaims[i].queue = calloc(1, CACHE_LINE_SIZE);
 425         else
 426                 for (i = 0; i < nr_writers; i++)
 427                         pending_reclaims[i].queue = calloc(reclaim_batch,
 428                                         sizeof(*pending_reclaims[i].queue));
 429         for (i = 0; i < nr_writers; i++)
 430                 pending_reclaims[i].head = pending_reclaims[i].queue;
 431
 432         next_aff = 0;
 433
 434         for (i = 0; i < nr_readers; i++) {
 435                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 436                                      &count_reader[i]);
 437                 if (err != 0)
 438                         exit(1);
 439         }
 440         for (i = 0; i < nr_writers; i++) {
 441                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 442                                      (void *)(long)i);
 443                 if (err != 0)
 444                         exit(1);
 445         }
 446
 447         smp_mb();
 448
 449         test_go = 1;
 450
 451         sleep(duration);
 452
 453         test_stop = 1;
 454
 455         for (i = 0; i < nr_readers; i++) {
 456                 err = pthread_join(tid_reader[i], &tret);
 457                 if (err != 0)
 458                         exit(1);
 459                 tot_reads += count_reader[i];
 460         }
 461         for (i = 0; i < nr_writers; i++) {
 462                 err = pthread_join(tid_writer[i], &tret);
 463                 if (err != 0)
 464                         exit(1);
 465                 tot_writes += tot_nr_writes[i];
 466                 rcu_gc_clear_queue(i);
 467         }
 468
 469         printf_verbose("total number of reads : %llu, writes %llu\n", tot_reads,
 470                tot_writes);
 471         printf("SUMMARY %-25s testdur %4lu nr_readers %3u rdur %6lu wdur %6lu "
 472                 "nr_writers %3u "
 473                 "wdelay %6lu nr_reads %12llu nr_writes %12llu nr_ops %12llu "
 474                 "batch %u\n",
 475                 argv[0], duration, nr_readers, rduration, wduration,
 476                 nr_writers, wdelay, tot_reads, tot_writes,
 477                 tot_reads + tot_writes, reclaim_batch);
 478         free(tid_reader);
 479         free(tid_writer);
 480         free(count_reader);
 481         free(tot_nr_writes);
 482         for (i = 0; i < nr_writers; i++)
 483                 free(pending_reclaims[i].queue);
 484         free(pending_reclaims);
 485
 486         return 0;
 487 }