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, write to the Free Software 18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 19 * 20 * Copyright (c) 2013 Mike D. Day, IBM Corporation. 21 */ 22 23 #include "qemu/osdep.h" 24 #include "qemu/atomic.h" 25 #include "qemu/rcu.h" 26 #include "qemu/thread.h" 27 #include "qemu/rcu_queue.h" 28 29 /* 30 * Test variables. 31 */ 32 33 static QemuMutex counts_mutex; 34 static long long n_reads = 0LL; 35 static long long n_updates = 0LL; 36 static int64_t n_reclaims; 37 static int64_t n_nodes_removed; 38 static long long n_nodes = 0LL; 39 static int g_test_in_charge = 0; 40 41 static int nthreadsrunning; 42 43 #define GOFLAG_INIT 0 44 #define GOFLAG_RUN 1 45 #define GOFLAG_STOP 2 46 47 static int goflag = GOFLAG_INIT; 48 49 #define RCU_READ_RUN 1000 50 #define RCU_UPDATE_RUN 10 51 #define NR_THREADS 100 52 #define RCU_Q_LEN 100 53 54 static QemuThread threads[NR_THREADS]; 55 static struct rcu_reader_data *data[NR_THREADS]; 56 static int n_threads; 57 58 static int select_random_el(int max) 59 { 60 return (rand() % max); 61 } 62 63 64 static void create_thread(void *(*func)(void *)) 65 { 66 if (n_threads >= NR_THREADS) { 67 fprintf(stderr, "Thread limit of %d exceeded!\n", NR_THREADS); 68 exit(-1); 69 } 70 qemu_thread_create(&threads[n_threads], "test", func, &data[n_threads], 71 QEMU_THREAD_JOINABLE); 72 n_threads++; 73 } 74 75 static void wait_all_threads(void) 76 { 77 int i; 78 79 for (i = 0; i < n_threads; i++) { 80 qemu_thread_join(&threads[i]); 81 } 82 n_threads = 0; 83 } 84 85 #ifndef TEST_LIST_TYPE 86 #define TEST_LIST_TYPE 1 87 #endif 88 89 struct list_element { 90 #if TEST_LIST_TYPE == 1 91 QLIST_ENTRY(list_element) entry; 92 #elif TEST_LIST_TYPE == 2 93 QSIMPLEQ_ENTRY(list_element) entry; 94 #elif TEST_LIST_TYPE == 3 95 QTAILQ_ENTRY(list_element) entry; 96 #else 97 #error Invalid TEST_LIST_TYPE 98 #endif 99 struct rcu_head rcu; 100 }; 101 102 static void reclaim_list_el(struct rcu_head *prcu) 103 { 104 struct list_element *el = container_of(prcu, struct list_element, rcu); 105 g_free(el); 106 /* Accessed only from call_rcu thread. */ 107 atomic_set_i64(&n_reclaims, n_reclaims + 1); 108 } 109 110 #if TEST_LIST_TYPE == 1 111 static QLIST_HEAD(, list_element) Q_list_head; 112 113 #define TEST_NAME "qlist" 114 #define TEST_LIST_REMOVE_RCU QLIST_REMOVE_RCU 115 #define TEST_LIST_INSERT_AFTER_RCU QLIST_INSERT_AFTER_RCU 116 #define TEST_LIST_INSERT_HEAD_RCU QLIST_INSERT_HEAD_RCU 117 #define TEST_LIST_FOREACH_RCU QLIST_FOREACH_RCU 118 #define TEST_LIST_FOREACH_SAFE_RCU QLIST_FOREACH_SAFE_RCU 119 120 #elif TEST_LIST_TYPE == 2 121 static QSIMPLEQ_HEAD(, list_element) Q_list_head = 122 QSIMPLEQ_HEAD_INITIALIZER(Q_list_head); 123 124 #define TEST_NAME "qsimpleq" 125 #define TEST_LIST_REMOVE_RCU(el, f) \ 126 QSIMPLEQ_REMOVE_RCU(&Q_list_head, el, list_element, f) 127 128 #define TEST_LIST_INSERT_AFTER_RCU(list_el, el, f) \ 129 QSIMPLEQ_INSERT_AFTER_RCU(&Q_list_head, list_el, el, f) 130 131 #define TEST_LIST_INSERT_HEAD_RCU QSIMPLEQ_INSERT_HEAD_RCU 132 #define TEST_LIST_FOREACH_RCU QSIMPLEQ_FOREACH_RCU 133 #define TEST_LIST_FOREACH_SAFE_RCU QSIMPLEQ_FOREACH_SAFE_RCU 134 135 #elif TEST_LIST_TYPE == 3 136 static QTAILQ_HEAD(, list_element) Q_list_head; 137 138 #define TEST_NAME "qtailq" 139 #define TEST_LIST_REMOVE_RCU(el, f) QTAILQ_REMOVE_RCU(&Q_list_head, el, f) 140 141 #define TEST_LIST_INSERT_AFTER_RCU(list_el, el, f) \ 142 QTAILQ_INSERT_AFTER_RCU(&Q_list_head, list_el, el, f) 143 144 #define TEST_LIST_INSERT_HEAD_RCU QTAILQ_INSERT_HEAD_RCU 145 #define TEST_LIST_FOREACH_RCU QTAILQ_FOREACH_RCU 146 #define TEST_LIST_FOREACH_SAFE_RCU QTAILQ_FOREACH_SAFE_RCU 147 #else 148 #error Invalid TEST_LIST_TYPE 149 #endif 150 151 static void *rcu_q_reader(void *arg) 152 { 153 long long n_reads_local = 0; 154 struct list_element *el; 155 156 rcu_register_thread(); 157 158 *(struct rcu_reader_data **)arg = &rcu_reader; 159 atomic_inc(&nthreadsrunning); 160 while (atomic_read(&goflag) == GOFLAG_INIT) { 161 g_usleep(1000); 162 } 163 164 while (atomic_read(&goflag) == GOFLAG_RUN) { 165 rcu_read_lock(); 166 TEST_LIST_FOREACH_RCU(el, &Q_list_head, entry) { 167 n_reads_local++; 168 if (atomic_read(&goflag) == GOFLAG_STOP) { 169 break; 170 } 171 } 172 rcu_read_unlock(); 173 174 g_usleep(100); 175 } 176 qemu_mutex_lock(&counts_mutex); 177 n_reads += n_reads_local; 178 qemu_mutex_unlock(&counts_mutex); 179 180 rcu_unregister_thread(); 181 return NULL; 182 } 183 184 185 static void *rcu_q_updater(void *arg) 186 { 187 int j, target_el; 188 long long n_nodes_local = 0; 189 long long n_updates_local = 0; 190 long long n_removed_local = 0; 191 struct list_element *el, *prev_el; 192 193 *(struct rcu_reader_data **)arg = &rcu_reader; 194 atomic_inc(&nthreadsrunning); 195 while (atomic_read(&goflag) == GOFLAG_INIT) { 196 g_usleep(1000); 197 } 198 199 while (atomic_read(&goflag) == GOFLAG_RUN) { 200 target_el = select_random_el(RCU_Q_LEN); 201 j = 0; 202 /* FOREACH_RCU could work here but let's use both macros */ 203 TEST_LIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) { 204 j++; 205 if (target_el == j) { 206 TEST_LIST_REMOVE_RCU(prev_el, entry); 207 /* may be more than one updater in the future */ 208 call_rcu1(&prev_el->rcu, reclaim_list_el); 209 n_removed_local++; 210 break; 211 } 212 } 213 if (atomic_read(&goflag) == GOFLAG_STOP) { 214 break; 215 } 216 target_el = select_random_el(RCU_Q_LEN); 217 j = 0; 218 TEST_LIST_FOREACH_RCU(el, &Q_list_head, entry) { 219 j++; 220 if (target_el == j) { 221 struct list_element *new_el = g_new(struct list_element, 1); 222 n_nodes += n_nodes_local; 223 TEST_LIST_INSERT_AFTER_RCU(el, new_el, entry); 224 break; 225 } 226 } 227 228 n_updates_local += 2; 229 synchronize_rcu(); 230 } 231 synchronize_rcu(); 232 qemu_mutex_lock(&counts_mutex); 233 n_nodes += n_nodes_local; 234 n_updates += n_updates_local; 235 atomic_set_i64(&n_nodes_removed, n_nodes_removed + n_removed_local); 236 qemu_mutex_unlock(&counts_mutex); 237 return NULL; 238 } 239 240 static void rcu_qtest_init(void) 241 { 242 struct list_element *new_el; 243 int i; 244 nthreadsrunning = 0; 245 srand(time(0)); 246 for (i = 0; i < RCU_Q_LEN; i++) { 247 new_el = g_new(struct list_element, 1); 248 TEST_LIST_INSERT_HEAD_RCU(&Q_list_head, new_el, entry); 249 } 250 qemu_mutex_lock(&counts_mutex); 251 n_nodes += RCU_Q_LEN; 252 qemu_mutex_unlock(&counts_mutex); 253 } 254 255 static void rcu_qtest_run(int duration, int nreaders) 256 { 257 int nthreads = nreaders + 1; 258 while (atomic_read(&nthreadsrunning) < nthreads) { 259 g_usleep(1000); 260 } 261 262 atomic_set(&goflag, GOFLAG_RUN); 263 sleep(duration); 264 atomic_set(&goflag, GOFLAG_STOP); 265 wait_all_threads(); 266 } 267 268 269 static void rcu_qtest(const char *test, int duration, int nreaders) 270 { 271 int i; 272 long long n_removed_local = 0; 273 274 struct list_element *el, *prev_el; 275 276 rcu_qtest_init(); 277 for (i = 0; i < nreaders; i++) { 278 create_thread(rcu_q_reader); 279 } 280 create_thread(rcu_q_updater); 281 rcu_qtest_run(duration, nreaders); 282 283 TEST_LIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) { 284 TEST_LIST_REMOVE_RCU(prev_el, entry); 285 call_rcu1(&prev_el->rcu, reclaim_list_el); 286 n_removed_local++; 287 } 288 qemu_mutex_lock(&counts_mutex); 289 atomic_set_i64(&n_nodes_removed, n_nodes_removed + n_removed_local); 290 qemu_mutex_unlock(&counts_mutex); 291 synchronize_rcu(); 292 while (atomic_read_i64(&n_nodes_removed) > atomic_read_i64(&n_reclaims)) { 293 g_usleep(100); 294 synchronize_rcu(); 295 } 296 if (g_test_in_charge) { 297 g_assert_cmpint(atomic_read_i64(&n_nodes_removed), ==, 298 atomic_read_i64(&n_reclaims)); 299 } else { 300 printf("%s: %d readers; 1 updater; nodes read: " \ 301 "%lld, nodes removed: %"PRIi64"; nodes reclaimed: %"PRIi64"\n", 302 test, nthreadsrunning - 1, n_reads, 303 atomic_read_i64(&n_nodes_removed), atomic_read_i64(&n_reclaims)); 304 exit(0); 305 } 306 } 307 308 static void usage(int argc, char *argv[]) 309 { 310 fprintf(stderr, "Usage: %s duration nreaders\n", argv[0]); 311 exit(-1); 312 } 313 314 static int gtest_seconds; 315 316 static void gtest_rcuq_one(void) 317 { 318 rcu_qtest("rcuqtest", gtest_seconds / 4, 1); 319 } 320 321 static void gtest_rcuq_few(void) 322 { 323 rcu_qtest("rcuqtest", gtest_seconds / 4, 5); 324 } 325 326 static void gtest_rcuq_many(void) 327 { 328 rcu_qtest("rcuqtest", gtest_seconds / 2, 20); 329 } 330 331 332 int main(int argc, char *argv[]) 333 { 334 int duration = 0, readers = 0; 335 336 qemu_mutex_init(&counts_mutex); 337 if (argc >= 2) { 338 if (argv[1][0] == '-') { 339 g_test_init(&argc, &argv, NULL); 340 if (g_test_quick()) { 341 gtest_seconds = 4; 342 } else { 343 gtest_seconds = 20; 344 } 345 g_test_add_func("/rcu/"TEST_NAME"/single-threaded", gtest_rcuq_one); 346 g_test_add_func("/rcu/"TEST_NAME"/short-few", gtest_rcuq_few); 347 g_test_add_func("/rcu/"TEST_NAME"/long-many", gtest_rcuq_many); 348 g_test_in_charge = 1; 349 return g_test_run(); 350 } 351 duration = strtoul(argv[1], NULL, 0); 352 } 353 if (argc >= 3) { 354 readers = strtoul(argv[2], NULL, 0); 355 } 356 if (duration && readers) { 357 rcu_qtest(argv[0], duration, readers); 358 return 0; 359 } 360 361 usage(argc, argv); 362 return -1; 363 } 364