Paolo Bonzini | 8fda74a | 2013-06-21 09:09:34 +0200 | [diff] [blame] | 1 | /* |
| 2 | * rcutorture.c: simple user-level performance/stress test of RCU. |
| 3 | * |
| 4 | * Usage: |
| 5 | * ./rcu <nreaders> rperf [ <seconds> ] |
| 6 | * Run a read-side performance test with the specified |
| 7 | * number of readers for <seconds> seconds. |
| 8 | * ./rcu <nupdaters> uperf [ <seconds> ] |
| 9 | * Run an update-side performance test with the specified |
| 10 | * number of updaters and specified duration. |
| 11 | * ./rcu <nreaders> perf [ <seconds> ] |
| 12 | * Run a combined read/update performance test with the specified |
| 13 | * number of readers and one updater and specified duration. |
| 14 | * |
| 15 | * The above tests produce output as follows: |
| 16 | * |
| 17 | * n_reads: 46008000 n_updates: 146026 nreaders: 2 nupdaters: 1 duration: 1 |
| 18 | * ns/read: 43.4707 ns/update: 6848.1 |
| 19 | * |
| 20 | * The first line lists the total number of RCU reads and updates executed |
| 21 | * during the test, the number of reader threads, the number of updater |
| 22 | * threads, and the duration of the test in seconds. The second line |
| 23 | * lists the average duration of each type of operation in nanoseconds, |
| 24 | * or "nan" if the corresponding type of operation was not performed. |
| 25 | * |
| 26 | * ./rcu <nreaders> stress [ <seconds> ] |
| 27 | * Run a stress test with the specified number of readers and |
| 28 | * one updater. |
| 29 | * |
| 30 | * This test produces output as follows: |
| 31 | * |
| 32 | * n_reads: 114633217 n_updates: 3903415 n_mberror: 0 |
| 33 | * rcu_stress_count: 114618391 14826 0 0 0 0 0 0 0 0 0 |
| 34 | * |
| 35 | * The first line lists the number of RCU read and update operations |
| 36 | * executed, followed by the number of memory-ordering violations |
| 37 | * (which will be zero in a correct RCU implementation). The second |
| 38 | * line lists the number of readers observing progressively more stale |
| 39 | * data. A correct RCU implementation will have all but the first two |
| 40 | * numbers non-zero. |
| 41 | * |
| 42 | * This program is free software; you can redistribute it and/or modify |
| 43 | * it under the terms of the GNU General Public License as published by |
| 44 | * the Free Software Foundation; either version 2 of the License, or |
| 45 | * (at your option) any later version. |
| 46 | * |
| 47 | * This program is distributed in the hope that it will be useful, |
| 48 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 49 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 50 | * GNU General Public License for more details. |
| 51 | * |
| 52 | * You should have received a copy of the GNU General Public License |
| 53 | * along with this program; if not, write to the Free Software |
| 54 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 55 | * |
| 56 | * Copyright (c) 2008 Paul E. McKenney, IBM Corporation. |
| 57 | */ |
| 58 | |
| 59 | /* |
| 60 | * Test variables. |
| 61 | */ |
| 62 | |
Peter Maydell | 681c28a | 2016-02-08 18:08:51 +0000 | [diff] [blame] | 63 | #include "qemu/osdep.h" |
Paolo Bonzini | 8fda74a | 2013-06-21 09:09:34 +0200 | [diff] [blame] | 64 | #include "qemu/atomic.h" |
| 65 | #include "qemu/rcu.h" |
Paolo Bonzini | 8fda74a | 2013-06-21 09:09:34 +0200 | [diff] [blame] | 66 | #include "qemu/thread.h" |
| 67 | |
| 68 | long long n_reads = 0LL; |
| 69 | long n_updates = 0L; |
| 70 | int nthreadsrunning; |
| 71 | |
| 72 | #define GOFLAG_INIT 0 |
| 73 | #define GOFLAG_RUN 1 |
| 74 | #define GOFLAG_STOP 2 |
| 75 | |
| 76 | static volatile int goflag = GOFLAG_INIT; |
| 77 | |
| 78 | #define RCU_READ_RUN 1000 |
| 79 | |
| 80 | #define NR_THREADS 100 |
Paolo Bonzini | 8a5956a | 2015-03-21 16:32:05 +0100 | [diff] [blame] | 81 | static QemuMutex counts_mutex; |
Paolo Bonzini | 8fda74a | 2013-06-21 09:09:34 +0200 | [diff] [blame] | 82 | static QemuThread threads[NR_THREADS]; |
| 83 | static struct rcu_reader_data *data[NR_THREADS]; |
| 84 | static int n_threads; |
| 85 | |
| 86 | static void create_thread(void *(*func)(void *)) |
| 87 | { |
| 88 | if (n_threads >= NR_THREADS) { |
| 89 | fprintf(stderr, "Thread limit of %d exceeded!\n", NR_THREADS); |
| 90 | exit(-1); |
| 91 | } |
| 92 | qemu_thread_create(&threads[n_threads], "test", func, &data[n_threads], |
| 93 | QEMU_THREAD_JOINABLE); |
| 94 | n_threads++; |
| 95 | } |
| 96 | |
| 97 | static void wait_all_threads(void) |
| 98 | { |
| 99 | int i; |
| 100 | |
| 101 | for (i = 0; i < n_threads; i++) { |
| 102 | qemu_thread_join(&threads[i]); |
| 103 | } |
| 104 | n_threads = 0; |
| 105 | } |
| 106 | |
| 107 | /* |
| 108 | * Performance test. |
| 109 | */ |
| 110 | |
| 111 | static void *rcu_read_perf_test(void *arg) |
| 112 | { |
| 113 | int i; |
| 114 | long long n_reads_local = 0; |
| 115 | |
| 116 | rcu_register_thread(); |
| 117 | |
| 118 | *(struct rcu_reader_data **)arg = &rcu_reader; |
| 119 | atomic_inc(&nthreadsrunning); |
| 120 | while (goflag == GOFLAG_INIT) { |
| 121 | g_usleep(1000); |
| 122 | } |
| 123 | while (goflag == GOFLAG_RUN) { |
| 124 | for (i = 0; i < RCU_READ_RUN; i++) { |
| 125 | rcu_read_lock(); |
| 126 | rcu_read_unlock(); |
| 127 | } |
| 128 | n_reads_local += RCU_READ_RUN; |
| 129 | } |
Paolo Bonzini | 8a5956a | 2015-03-21 16:32:05 +0100 | [diff] [blame] | 130 | qemu_mutex_lock(&counts_mutex); |
| 131 | n_reads += n_reads_local; |
| 132 | qemu_mutex_unlock(&counts_mutex); |
Paolo Bonzini | 8fda74a | 2013-06-21 09:09:34 +0200 | [diff] [blame] | 133 | |
| 134 | rcu_unregister_thread(); |
| 135 | return NULL; |
| 136 | } |
| 137 | |
| 138 | static void *rcu_update_perf_test(void *arg) |
| 139 | { |
| 140 | long long n_updates_local = 0; |
| 141 | |
| 142 | rcu_register_thread(); |
| 143 | |
| 144 | *(struct rcu_reader_data **)arg = &rcu_reader; |
| 145 | atomic_inc(&nthreadsrunning); |
| 146 | while (goflag == GOFLAG_INIT) { |
| 147 | g_usleep(1000); |
| 148 | } |
| 149 | while (goflag == GOFLAG_RUN) { |
| 150 | synchronize_rcu(); |
| 151 | n_updates_local++; |
| 152 | } |
Paolo Bonzini | 8a5956a | 2015-03-21 16:32:05 +0100 | [diff] [blame] | 153 | qemu_mutex_lock(&counts_mutex); |
| 154 | n_updates += n_updates_local; |
| 155 | qemu_mutex_unlock(&counts_mutex); |
Paolo Bonzini | 8fda74a | 2013-06-21 09:09:34 +0200 | [diff] [blame] | 156 | |
| 157 | rcu_unregister_thread(); |
| 158 | return NULL; |
| 159 | } |
| 160 | |
| 161 | static void perftestinit(void) |
| 162 | { |
| 163 | nthreadsrunning = 0; |
| 164 | } |
| 165 | |
| 166 | static void perftestrun(int nthreads, int duration, int nreaders, int nupdaters) |
| 167 | { |
| 168 | while (atomic_read(&nthreadsrunning) < nthreads) { |
| 169 | g_usleep(1000); |
| 170 | } |
| 171 | goflag = GOFLAG_RUN; |
| 172 | g_usleep(duration * G_USEC_PER_SEC); |
| 173 | goflag = GOFLAG_STOP; |
| 174 | wait_all_threads(); |
| 175 | printf("n_reads: %lld n_updates: %ld nreaders: %d nupdaters: %d duration: %d\n", |
| 176 | n_reads, n_updates, nreaders, nupdaters, duration); |
| 177 | printf("ns/read: %g ns/update: %g\n", |
| 178 | ((duration * 1000*1000*1000.*(double)nreaders) / |
| 179 | (double)n_reads), |
| 180 | ((duration * 1000*1000*1000.*(double)nupdaters) / |
| 181 | (double)n_updates)); |
| 182 | exit(0); |
| 183 | } |
| 184 | |
| 185 | static void perftest(int nreaders, int duration) |
| 186 | { |
| 187 | int i; |
| 188 | |
| 189 | perftestinit(); |
| 190 | for (i = 0; i < nreaders; i++) { |
| 191 | create_thread(rcu_read_perf_test); |
| 192 | } |
| 193 | create_thread(rcu_update_perf_test); |
| 194 | perftestrun(i + 1, duration, nreaders, 1); |
| 195 | } |
| 196 | |
| 197 | static void rperftest(int nreaders, int duration) |
| 198 | { |
| 199 | int i; |
| 200 | |
| 201 | perftestinit(); |
| 202 | for (i = 0; i < nreaders; i++) { |
| 203 | create_thread(rcu_read_perf_test); |
| 204 | } |
| 205 | perftestrun(i, duration, nreaders, 0); |
| 206 | } |
| 207 | |
| 208 | static void uperftest(int nupdaters, int duration) |
| 209 | { |
| 210 | int i; |
| 211 | |
| 212 | perftestinit(); |
| 213 | for (i = 0; i < nupdaters; i++) { |
| 214 | create_thread(rcu_update_perf_test); |
| 215 | } |
| 216 | perftestrun(i, duration, 0, nupdaters); |
| 217 | } |
| 218 | |
| 219 | /* |
| 220 | * Stress test. |
| 221 | */ |
| 222 | |
| 223 | #define RCU_STRESS_PIPE_LEN 10 |
| 224 | |
| 225 | struct rcu_stress { |
| 226 | int pipe_count; |
| 227 | int mbtest; |
| 228 | }; |
| 229 | |
| 230 | struct rcu_stress rcu_stress_array[RCU_STRESS_PIPE_LEN] = { { 0 } }; |
| 231 | struct rcu_stress *rcu_stress_current; |
| 232 | int rcu_stress_idx; |
| 233 | |
| 234 | int n_mberror; |
| 235 | long long rcu_stress_count[RCU_STRESS_PIPE_LEN + 1]; |
| 236 | |
| 237 | |
| 238 | static void *rcu_read_stress_test(void *arg) |
| 239 | { |
| 240 | int i; |
Paolo Bonzini | 8fda74a | 2013-06-21 09:09:34 +0200 | [diff] [blame] | 241 | struct rcu_stress *p; |
| 242 | int pc; |
| 243 | long long n_reads_local = 0; |
Paolo Bonzini | 8a5956a | 2015-03-21 16:32:05 +0100 | [diff] [blame] | 244 | long long rcu_stress_local[RCU_STRESS_PIPE_LEN + 1] = { 0 }; |
Paolo Bonzini | 8fda74a | 2013-06-21 09:09:34 +0200 | [diff] [blame] | 245 | volatile int garbage = 0; |
| 246 | |
| 247 | rcu_register_thread(); |
| 248 | |
| 249 | *(struct rcu_reader_data **)arg = &rcu_reader; |
| 250 | while (goflag == GOFLAG_INIT) { |
| 251 | g_usleep(1000); |
| 252 | } |
| 253 | while (goflag == GOFLAG_RUN) { |
| 254 | rcu_read_lock(); |
| 255 | p = atomic_rcu_read(&rcu_stress_current); |
| 256 | if (p->mbtest == 0) { |
| 257 | n_mberror++; |
| 258 | } |
Paolo Bonzini | d62cb4f | 2015-01-13 17:34:15 +0100 | [diff] [blame] | 259 | rcu_read_lock(); |
Paolo Bonzini | 8fda74a | 2013-06-21 09:09:34 +0200 | [diff] [blame] | 260 | for (i = 0; i < 100; i++) { |
| 261 | garbage++; |
| 262 | } |
Paolo Bonzini | d62cb4f | 2015-01-13 17:34:15 +0100 | [diff] [blame] | 263 | rcu_read_unlock(); |
Paolo Bonzini | 8fda74a | 2013-06-21 09:09:34 +0200 | [diff] [blame] | 264 | pc = p->pipe_count; |
| 265 | rcu_read_unlock(); |
| 266 | if ((pc > RCU_STRESS_PIPE_LEN) || (pc < 0)) { |
| 267 | pc = RCU_STRESS_PIPE_LEN; |
| 268 | } |
Paolo Bonzini | 8a5956a | 2015-03-21 16:32:05 +0100 | [diff] [blame] | 269 | rcu_stress_local[pc]++; |
Paolo Bonzini | 8fda74a | 2013-06-21 09:09:34 +0200 | [diff] [blame] | 270 | n_reads_local++; |
Paolo Bonzini | 8fda74a | 2013-06-21 09:09:34 +0200 | [diff] [blame] | 271 | } |
Paolo Bonzini | 8a5956a | 2015-03-21 16:32:05 +0100 | [diff] [blame] | 272 | qemu_mutex_lock(&counts_mutex); |
| 273 | n_reads += n_reads_local; |
| 274 | for (i = 0; i <= RCU_STRESS_PIPE_LEN; i++) { |
| 275 | rcu_stress_count[i] += rcu_stress_local[i]; |
| 276 | } |
| 277 | qemu_mutex_unlock(&counts_mutex); |
Paolo Bonzini | 8fda74a | 2013-06-21 09:09:34 +0200 | [diff] [blame] | 278 | |
| 279 | rcu_unregister_thread(); |
| 280 | return NULL; |
| 281 | } |
| 282 | |
| 283 | static void *rcu_update_stress_test(void *arg) |
| 284 | { |
| 285 | int i; |
| 286 | struct rcu_stress *p; |
| 287 | |
| 288 | rcu_register_thread(); |
| 289 | |
| 290 | *(struct rcu_reader_data **)arg = &rcu_reader; |
| 291 | while (goflag == GOFLAG_INIT) { |
| 292 | g_usleep(1000); |
| 293 | } |
| 294 | while (goflag == GOFLAG_RUN) { |
| 295 | i = rcu_stress_idx + 1; |
| 296 | if (i >= RCU_STRESS_PIPE_LEN) { |
| 297 | i = 0; |
| 298 | } |
| 299 | p = &rcu_stress_array[i]; |
| 300 | p->mbtest = 0; |
| 301 | smp_mb(); |
| 302 | p->pipe_count = 0; |
| 303 | p->mbtest = 1; |
| 304 | atomic_rcu_set(&rcu_stress_current, p); |
| 305 | rcu_stress_idx = i; |
| 306 | for (i = 0; i < RCU_STRESS_PIPE_LEN; i++) { |
| 307 | if (i != rcu_stress_idx) { |
| 308 | rcu_stress_array[i].pipe_count++; |
| 309 | } |
| 310 | } |
| 311 | synchronize_rcu(); |
| 312 | n_updates++; |
| 313 | } |
| 314 | |
| 315 | rcu_unregister_thread(); |
| 316 | return NULL; |
| 317 | } |
| 318 | |
| 319 | static void *rcu_fake_update_stress_test(void *arg) |
| 320 | { |
| 321 | rcu_register_thread(); |
| 322 | |
| 323 | *(struct rcu_reader_data **)arg = &rcu_reader; |
| 324 | while (goflag == GOFLAG_INIT) { |
| 325 | g_usleep(1000); |
| 326 | } |
| 327 | while (goflag == GOFLAG_RUN) { |
| 328 | synchronize_rcu(); |
| 329 | g_usleep(1000); |
| 330 | } |
| 331 | |
| 332 | rcu_unregister_thread(); |
| 333 | return NULL; |
| 334 | } |
| 335 | |
| 336 | static void stresstest(int nreaders, int duration) |
| 337 | { |
| 338 | int i; |
| 339 | |
| 340 | rcu_stress_current = &rcu_stress_array[0]; |
| 341 | rcu_stress_current->pipe_count = 0; |
| 342 | rcu_stress_current->mbtest = 1; |
| 343 | for (i = 0; i < nreaders; i++) { |
| 344 | create_thread(rcu_read_stress_test); |
| 345 | } |
| 346 | create_thread(rcu_update_stress_test); |
| 347 | for (i = 0; i < 5; i++) { |
| 348 | create_thread(rcu_fake_update_stress_test); |
| 349 | } |
| 350 | goflag = GOFLAG_RUN; |
| 351 | g_usleep(duration * G_USEC_PER_SEC); |
| 352 | goflag = GOFLAG_STOP; |
| 353 | wait_all_threads(); |
| 354 | printf("n_reads: %lld n_updates: %ld n_mberror: %d\n", |
| 355 | n_reads, n_updates, n_mberror); |
| 356 | printf("rcu_stress_count:"); |
| 357 | for (i = 0; i <= RCU_STRESS_PIPE_LEN; i++) { |
| 358 | printf(" %lld", rcu_stress_count[i]); |
| 359 | } |
| 360 | printf("\n"); |
| 361 | exit(0); |
| 362 | } |
| 363 | |
| 364 | /* GTest interface */ |
| 365 | |
| 366 | static void gtest_stress(int nreaders, int duration) |
| 367 | { |
| 368 | int i; |
| 369 | |
| 370 | rcu_stress_current = &rcu_stress_array[0]; |
| 371 | rcu_stress_current->pipe_count = 0; |
| 372 | rcu_stress_current->mbtest = 1; |
| 373 | for (i = 0; i < nreaders; i++) { |
| 374 | create_thread(rcu_read_stress_test); |
| 375 | } |
| 376 | create_thread(rcu_update_stress_test); |
| 377 | for (i = 0; i < 5; i++) { |
| 378 | create_thread(rcu_fake_update_stress_test); |
| 379 | } |
| 380 | goflag = GOFLAG_RUN; |
| 381 | g_usleep(duration * G_USEC_PER_SEC); |
| 382 | goflag = GOFLAG_STOP; |
| 383 | wait_all_threads(); |
| 384 | g_assert_cmpint(n_mberror, ==, 0); |
| 385 | for (i = 2; i <= RCU_STRESS_PIPE_LEN; i++) { |
| 386 | g_assert_cmpint(rcu_stress_count[i], ==, 0); |
| 387 | } |
| 388 | } |
| 389 | |
| 390 | static void gtest_stress_1_1(void) |
| 391 | { |
| 392 | gtest_stress(1, 1); |
| 393 | } |
| 394 | |
| 395 | static void gtest_stress_10_1(void) |
| 396 | { |
| 397 | gtest_stress(10, 1); |
| 398 | } |
| 399 | |
| 400 | static void gtest_stress_1_5(void) |
| 401 | { |
| 402 | gtest_stress(1, 5); |
| 403 | } |
| 404 | |
| 405 | static void gtest_stress_10_5(void) |
| 406 | { |
| 407 | gtest_stress(10, 5); |
| 408 | } |
| 409 | |
| 410 | /* |
| 411 | * Mainprogram. |
| 412 | */ |
| 413 | |
| 414 | static void usage(int argc, char *argv[]) |
| 415 | { |
| 416 | fprintf(stderr, "Usage: %s [nreaders [ perf | stress ] ]\n", argv[0]); |
| 417 | exit(-1); |
| 418 | } |
| 419 | |
| 420 | int main(int argc, char *argv[]) |
| 421 | { |
| 422 | int nreaders = 1; |
| 423 | int duration = 1; |
| 424 | |
Paolo Bonzini | 8a5956a | 2015-03-21 16:32:05 +0100 | [diff] [blame] | 425 | qemu_mutex_init(&counts_mutex); |
Paolo Bonzini | 8fda74a | 2013-06-21 09:09:34 +0200 | [diff] [blame] | 426 | if (argc >= 2 && argv[1][0] == '-') { |
| 427 | g_test_init(&argc, &argv, NULL); |
| 428 | if (g_test_quick()) { |
| 429 | g_test_add_func("/rcu/torture/1reader", gtest_stress_1_1); |
| 430 | g_test_add_func("/rcu/torture/10readers", gtest_stress_10_1); |
| 431 | } else { |
| 432 | g_test_add_func("/rcu/torture/1reader", gtest_stress_1_5); |
| 433 | g_test_add_func("/rcu/torture/10readers", gtest_stress_10_5); |
| 434 | } |
| 435 | return g_test_run(); |
| 436 | } |
| 437 | |
| 438 | if (argc >= 2) { |
| 439 | nreaders = strtoul(argv[1], NULL, 0); |
| 440 | } |
| 441 | if (argc > 3) { |
| 442 | duration = strtoul(argv[3], NULL, 0); |
| 443 | } |
| 444 | if (argc < 3 || strcmp(argv[2], "stress") == 0) { |
| 445 | stresstest(nreaders, duration); |
| 446 | } else if (strcmp(argv[2], "rperf") == 0) { |
| 447 | rperftest(nreaders, duration); |
| 448 | } else if (strcmp(argv[2], "uperf") == 0) { |
| 449 | uperftest(nreaders, duration); |
| 450 | } else if (strcmp(argv[2], "perf") == 0) { |
| 451 | perftest(nreaders, duration); |
| 452 | } |
| 453 | usage(argc, argv); |
| 454 | return 0; |
| 455 | } |