1 /* 2 * rcuq_test.c 3 * 4 * usage: rcuq_test <readers> <duration> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program. If not, see <https://www.gnu.org/licenses/>. 18 * 19 * Copyright (c) 2013 Mike D. Day, IBM Corporation. 20 */ 21 22 #include "qemu/osdep.h" 23 #include "qemu/atomic.h" 24 #include "qemu/rcu.h" 25 #include "qemu/thread.h" 26 #include "qemu/rcu_queue.h" 27 28 /* 29 * Test variables. 30 */ 31 32 static QemuMutex counts_mutex; 33 static long long n_reads = 0LL; 34 static long long n_updates = 0LL; 35 static int64_t n_reclaims; 36 static int64_t n_nodes_removed; 37 static long long n_nodes = 0LL; 38 static int g_test_in_charge = 0; 39 40 static int nthreadsrunning; 41 42 #define GOFLAG_INIT 0 43 #define GOFLAG_RUN 1 44 #define GOFLAG_STOP 2 45 46 static int goflag = GOFLAG_INIT; 47 48 #define RCU_READ_RUN 1000 49 #define RCU_UPDATE_RUN 10 50 #define NR_THREADS 100 51 #define RCU_Q_LEN 100 52 53 static QemuThread threads[NR_THREADS]; 54 static struct rcu_reader_data *data[NR_THREADS]; 55 static int n_threads; 56 57 static int select_random_el(int max) 58 { 59 return (rand() % max); 60 } 61 62 63 static void create_thread(void *(*func)(void *)) 64 { 65 if (n_threads >= NR_THREADS) { 66 fprintf(stderr, "Thread limit of %d exceeded!\n", NR_THREADS); 67 exit(-1); 68 } 69 qemu_thread_create(&threads[n_threads], "test", func, &data[n_threads], 70 QEMU_THREAD_JOINABLE); 71 n_threads++; 72 } 73 74 static void wait_all_threads(void) 75 { 76 int i; 77 78 for (i = 0; i < n_threads; i++) { 79 qemu_thread_join(&threads[i]); 80 } 81 n_threads = 0; 82 } 83 84 #ifndef TEST_LIST_TYPE 85 #define TEST_LIST_TYPE 1 86 #endif 87 88 struct list_element { 89 #if TEST_LIST_TYPE == 1 90 QLIST_ENTRY(list_element) entry; 91 #elif TEST_LIST_TYPE == 2 92 QSIMPLEQ_ENTRY(list_element) entry; 93 #elif TEST_LIST_TYPE == 3 94 QTAILQ_ENTRY(list_element) entry; 95 #elif TEST_LIST_TYPE == 4 96 QSLIST_ENTRY(list_element) entry; 97 #else 98 #error Invalid TEST_LIST_TYPE 99 #endif 100 struct rcu_head rcu; 101 }; 102 103 static void reclaim_list_el(struct rcu_head *prcu) 104 { 105 struct list_element *el = container_of(prcu, struct list_element, rcu); 106 g_free(el); 107 /* Accessed only from call_rcu thread. */ 108 qatomic_set_i64(&n_reclaims, n_reclaims + 1); 109 } 110 111 #if TEST_LIST_TYPE == 1 112 static QLIST_HEAD(, list_element) Q_list_head; 113 114 #define TEST_NAME "qlist" 115 #define TEST_LIST_REMOVE_RCU QLIST_REMOVE_RCU 116 #define TEST_LIST_INSERT_AFTER_RCU QLIST_INSERT_AFTER_RCU 117 #define TEST_LIST_INSERT_HEAD_RCU QLIST_INSERT_HEAD_RCU 118 #define TEST_LIST_FOREACH_RCU QLIST_FOREACH_RCU 119 #define TEST_LIST_FOREACH_SAFE_RCU QLIST_FOREACH_SAFE_RCU 120 121 #elif TEST_LIST_TYPE == 2 122 static QSIMPLEQ_HEAD(, list_element) Q_list_head = 123 QSIMPLEQ_HEAD_INITIALIZER(Q_list_head); 124 125 #define TEST_NAME "qsimpleq" 126 #define TEST_LIST_REMOVE_RCU(el, f) \ 127 QSIMPLEQ_REMOVE_RCU(&Q_list_head, el, list_element, f) 128 129 #define TEST_LIST_INSERT_AFTER_RCU(list_el, el, f) \ 130 QSIMPLEQ_INSERT_AFTER_RCU(&Q_list_head, list_el, el, f) 131 132 #define TEST_LIST_INSERT_HEAD_RCU QSIMPLEQ_INSERT_HEAD_RCU 133 #define TEST_LIST_FOREACH_RCU QSIMPLEQ_FOREACH_RCU 134 #define TEST_LIST_FOREACH_SAFE_RCU QSIMPLEQ_FOREACH_SAFE_RCU 135 136 #elif TEST_LIST_TYPE == 3 137 static QTAILQ_HEAD(, list_element) Q_list_head; 138 139 #define TEST_NAME "qtailq" 140 #define TEST_LIST_REMOVE_RCU(el, f) QTAILQ_REMOVE_RCU(&Q_list_head, el, f) 141 142 #define TEST_LIST_INSERT_AFTER_RCU(list_el, el, f) \ 143 QTAILQ_INSERT_AFTER_RCU(&Q_list_head, list_el, el, f) 144 145 #define TEST_LIST_INSERT_HEAD_RCU QTAILQ_INSERT_HEAD_RCU 146 #define TEST_LIST_FOREACH_RCU QTAILQ_FOREACH_RCU 147 #define TEST_LIST_FOREACH_SAFE_RCU QTAILQ_FOREACH_SAFE_RCU 148 149 #elif TEST_LIST_TYPE == 4 150 static QSLIST_HEAD(, list_element) Q_list_head; 151 152 #define TEST_NAME "qslist" 153 #define TEST_LIST_REMOVE_RCU(el, f) \ 154 QSLIST_REMOVE_RCU(&Q_list_head, el, list_element, f) 155 156 #define TEST_LIST_INSERT_AFTER_RCU(list_el, el, f) \ 157 QSLIST_INSERT_AFTER_RCU(&Q_list_head, list_el, el, f) 158 159 #define TEST_LIST_INSERT_HEAD_RCU QSLIST_INSERT_HEAD_RCU 160 #define TEST_LIST_FOREACH_RCU QSLIST_FOREACH_RCU 161 #define TEST_LIST_FOREACH_SAFE_RCU QSLIST_FOREACH_SAFE_RCU 162 #else 163 #error Invalid TEST_LIST_TYPE 164 #endif 165 166 static void *rcu_q_reader(void *arg) 167 { 168 long long n_reads_local = 0; 169 struct list_element *el; 170 171 rcu_register_thread(); 172 173 *(struct rcu_reader_data **)arg = get_ptr_rcu_reader(); 174 qatomic_inc(&nthreadsrunning); 175 while (qatomic_read(&goflag) == GOFLAG_INIT) { 176 g_usleep(1000); 177 } 178 179 while (qatomic_read(&goflag) == GOFLAG_RUN) { 180 rcu_read_lock(); 181 TEST_LIST_FOREACH_RCU(el, &Q_list_head, entry) { 182 n_reads_local++; 183 if (qatomic_read(&goflag) == GOFLAG_STOP) { 184 break; 185 } 186 } 187 rcu_read_unlock(); 188 189 g_usleep(100); 190 } 191 qemu_mutex_lock(&counts_mutex); 192 n_reads += n_reads_local; 193 qemu_mutex_unlock(&counts_mutex); 194 195 rcu_unregister_thread(); 196 return NULL; 197 } 198 199 200 static void *rcu_q_updater(void *arg) 201 { 202 int j, target_el; 203 long long n_nodes_local = 0; 204 long long n_updates_local = 0; 205 long long n_removed_local = 0; 206 struct list_element *el, *prev_el; 207 208 *(struct rcu_reader_data **)arg = get_ptr_rcu_reader(); 209 qatomic_inc(&nthreadsrunning); 210 while (qatomic_read(&goflag) == GOFLAG_INIT) { 211 g_usleep(1000); 212 } 213 214 while (qatomic_read(&goflag) == GOFLAG_RUN) { 215 target_el = select_random_el(RCU_Q_LEN); 216 j = 0; 217 /* FOREACH_RCU could work here but let's use both macros */ 218 TEST_LIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) { 219 j++; 220 if (target_el == j) { 221 TEST_LIST_REMOVE_RCU(prev_el, entry); 222 /* may be more than one updater in the future */ 223 call_rcu1(&prev_el->rcu, reclaim_list_el); 224 n_removed_local++; 225 break; 226 } 227 } 228 if (qatomic_read(&goflag) == GOFLAG_STOP) { 229 break; 230 } 231 target_el = select_random_el(RCU_Q_LEN); 232 j = 0; 233 TEST_LIST_FOREACH_RCU(el, &Q_list_head, entry) { 234 j++; 235 if (target_el == j) { 236 struct list_element *new_el = g_new(struct list_element, 1); 237 n_nodes_local++; 238 TEST_LIST_INSERT_AFTER_RCU(el, new_el, entry); 239 break; 240 } 241 } 242 243 n_updates_local += 2; 244 synchronize_rcu(); 245 } 246 synchronize_rcu(); 247 qemu_mutex_lock(&counts_mutex); 248 n_nodes += n_nodes_local; 249 n_updates += n_updates_local; 250 qatomic_set_i64(&n_nodes_removed, n_nodes_removed + n_removed_local); 251 qemu_mutex_unlock(&counts_mutex); 252 return NULL; 253 } 254 255 static void rcu_qtest_init(void) 256 { 257 struct list_element *new_el; 258 int i; 259 nthreadsrunning = 0; 260 srand(time(0)); 261 for (i = 0; i < RCU_Q_LEN; i++) { 262 new_el = g_new(struct list_element, 1); 263 TEST_LIST_INSERT_HEAD_RCU(&Q_list_head, new_el, entry); 264 } 265 qemu_mutex_lock(&counts_mutex); 266 n_nodes += RCU_Q_LEN; 267 qemu_mutex_unlock(&counts_mutex); 268 } 269 270 static void rcu_qtest_run(int duration, int nreaders) 271 { 272 int nthreads = nreaders + 1; 273 while (qatomic_read(&nthreadsrunning) < nthreads) { 274 g_usleep(1000); 275 } 276 277 qatomic_set(&goflag, GOFLAG_RUN); 278 sleep(duration); 279 qatomic_set(&goflag, GOFLAG_STOP); 280 wait_all_threads(); 281 } 282 283 284 static void rcu_qtest(const char *test, int duration, int nreaders) 285 { 286 int i; 287 long long n_removed_local = 0; 288 289 struct list_element *el, *prev_el; 290 291 rcu_qtest_init(); 292 for (i = 0; i < nreaders; i++) { 293 create_thread(rcu_q_reader); 294 } 295 create_thread(rcu_q_updater); 296 rcu_qtest_run(duration, nreaders); 297 298 TEST_LIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) { 299 TEST_LIST_REMOVE_RCU(prev_el, entry); 300 call_rcu1(&prev_el->rcu, reclaim_list_el); 301 n_removed_local++; 302 } 303 qemu_mutex_lock(&counts_mutex); 304 qatomic_set_i64(&n_nodes_removed, n_nodes_removed + n_removed_local); 305 qemu_mutex_unlock(&counts_mutex); 306 synchronize_rcu(); 307 while (qatomic_read_i64(&n_nodes_removed) > 308 qatomic_read_i64(&n_reclaims)) { 309 g_usleep(100); 310 synchronize_rcu(); 311 } 312 if (g_test_in_charge) { 313 g_assert_cmpint(qatomic_read_i64(&n_nodes_removed), ==, 314 qatomic_read_i64(&n_reclaims)); 315 } else { 316 printf("%s: %d readers; 1 updater; nodes read: " \ 317 "%lld, nodes removed: %"PRIi64"; nodes reclaimed: %"PRIi64"\n", 318 test, nthreadsrunning - 1, n_reads, 319 qatomic_read_i64(&n_nodes_removed), 320 qatomic_read_i64(&n_reclaims)); 321 exit(0); 322 } 323 } 324 325 static void usage(int argc, char *argv[]) 326 { 327 fprintf(stderr, "Usage: %s duration nreaders\n", argv[0]); 328 exit(-1); 329 } 330 331 static int gtest_seconds; 332 333 static void gtest_rcuq_one(void) 334 { 335 rcu_qtest("rcuqtest", gtest_seconds / 4, 1); 336 } 337 338 static void gtest_rcuq_few(void) 339 { 340 rcu_qtest("rcuqtest", gtest_seconds / 4, 5); 341 } 342 343 static void gtest_rcuq_many(void) 344 { 345 rcu_qtest("rcuqtest", gtest_seconds / 2, 20); 346 } 347 348 349 int main(int argc, char *argv[]) 350 { 351 int duration = 0, readers = 0; 352 353 qemu_mutex_init(&counts_mutex); 354 if (argc >= 2) { 355 if (argv[1][0] == '-') { 356 g_test_init(&argc, &argv, NULL); 357 if (g_test_quick()) { 358 gtest_seconds = 4; 359 } else { 360 gtest_seconds = 20; 361 } 362 g_test_add_func("/rcu/"TEST_NAME"/single-threaded", gtest_rcuq_one); 363 g_test_add_func("/rcu/"TEST_NAME"/short-few", gtest_rcuq_few); 364 g_test_add_func("/rcu/"TEST_NAME"/long-many", gtest_rcuq_many); 365 g_test_in_charge = 1; 366 return g_test_run(); 367 } 368 duration = strtoul(argv[1], NULL, 0); 369 } 370 if (argc >= 3) { 371 readers = strtoul(argv[2], NULL, 0); 372 } 373 if (duration && readers) { 374 rcu_qtest(argv[0], duration, readers); 375 return 0; 376 } 377 378 usage(argc, argv); 379 return -1; 380 } 381