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 long long n_reclaims = 0LL; 37 static long long n_nodes_removed = 0LL; 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 #else 95 #error Invalid TEST_LIST_TYPE 96 #endif 97 struct rcu_head rcu; 98 }; 99 100 static void reclaim_list_el(struct rcu_head *prcu) 101 { 102 struct list_element *el = container_of(prcu, struct list_element, rcu); 103 g_free(el); 104 /* Accessed only from call_rcu thread. */ 105 n_reclaims++; 106 } 107 108 #if TEST_LIST_TYPE == 1 109 static QLIST_HEAD(q_list_head, list_element) Q_list_head; 110 111 #define TEST_NAME "qlist" 112 #define TEST_LIST_REMOVE_RCU QLIST_REMOVE_RCU 113 #define TEST_LIST_INSERT_AFTER_RCU QLIST_INSERT_AFTER_RCU 114 #define TEST_LIST_INSERT_HEAD_RCU QLIST_INSERT_HEAD_RCU 115 #define TEST_LIST_FOREACH_RCU QLIST_FOREACH_RCU 116 #define TEST_LIST_FOREACH_SAFE_RCU QLIST_FOREACH_SAFE_RCU 117 118 #elif TEST_LIST_TYPE == 2 119 static QSIMPLEQ_HEAD(, list_element) Q_list_head = 120 QSIMPLEQ_HEAD_INITIALIZER(Q_list_head); 121 122 #define TEST_NAME "qsimpleq" 123 #define TEST_LIST_REMOVE_RCU(el, f) \ 124 QSIMPLEQ_REMOVE_RCU(&Q_list_head, el, list_element, f) 125 126 #define TEST_LIST_INSERT_AFTER_RCU(list_el, el, f) \ 127 QSIMPLEQ_INSERT_AFTER_RCU(&Q_list_head, list_el, el, f) 128 129 #define TEST_LIST_INSERT_HEAD_RCU QSIMPLEQ_INSERT_HEAD_RCU 130 #define TEST_LIST_FOREACH_RCU QSIMPLEQ_FOREACH_RCU 131 #define TEST_LIST_FOREACH_SAFE_RCU QSIMPLEQ_FOREACH_SAFE_RCU 132 #else 133 #error Invalid TEST_LIST_TYPE 134 #endif 135 136 static void *rcu_q_reader(void *arg) 137 { 138 long long n_reads_local = 0; 139 struct list_element *el; 140 141 rcu_register_thread(); 142 143 *(struct rcu_reader_data **)arg = &rcu_reader; 144 atomic_inc(&nthreadsrunning); 145 while (atomic_read(&goflag) == GOFLAG_INIT) { 146 g_usleep(1000); 147 } 148 149 while (atomic_read(&goflag) == GOFLAG_RUN) { 150 rcu_read_lock(); 151 TEST_LIST_FOREACH_RCU(el, &Q_list_head, entry) { 152 n_reads_local++; 153 if (atomic_read(&goflag) == GOFLAG_STOP) { 154 break; 155 } 156 } 157 rcu_read_unlock(); 158 159 g_usleep(100); 160 } 161 qemu_mutex_lock(&counts_mutex); 162 n_reads += n_reads_local; 163 qemu_mutex_unlock(&counts_mutex); 164 165 rcu_unregister_thread(); 166 return NULL; 167 } 168 169 170 static void *rcu_q_updater(void *arg) 171 { 172 int j, target_el; 173 long long n_nodes_local = 0; 174 long long n_updates_local = 0; 175 long long n_removed_local = 0; 176 struct list_element *el, *prev_el; 177 178 *(struct rcu_reader_data **)arg = &rcu_reader; 179 atomic_inc(&nthreadsrunning); 180 while (atomic_read(&goflag) == GOFLAG_INIT) { 181 g_usleep(1000); 182 } 183 184 while (atomic_read(&goflag) == GOFLAG_RUN) { 185 target_el = select_random_el(RCU_Q_LEN); 186 j = 0; 187 /* FOREACH_RCU could work here but let's use both macros */ 188 TEST_LIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) { 189 j++; 190 if (target_el == j) { 191 TEST_LIST_REMOVE_RCU(prev_el, entry); 192 /* may be more than one updater in the future */ 193 call_rcu1(&prev_el->rcu, reclaim_list_el); 194 n_removed_local++; 195 break; 196 } 197 } 198 if (atomic_read(&goflag) == GOFLAG_STOP) { 199 break; 200 } 201 target_el = select_random_el(RCU_Q_LEN); 202 j = 0; 203 TEST_LIST_FOREACH_RCU(el, &Q_list_head, entry) { 204 j++; 205 if (target_el == j) { 206 struct list_element *new_el = g_new(struct list_element, 1); 207 n_nodes += n_nodes_local; 208 TEST_LIST_INSERT_AFTER_RCU(el, new_el, entry); 209 break; 210 } 211 } 212 213 n_updates_local += 2; 214 synchronize_rcu(); 215 } 216 synchronize_rcu(); 217 qemu_mutex_lock(&counts_mutex); 218 n_nodes += n_nodes_local; 219 n_updates += n_updates_local; 220 n_nodes_removed += n_removed_local; 221 qemu_mutex_unlock(&counts_mutex); 222 return NULL; 223 } 224 225 static void rcu_qtest_init(void) 226 { 227 struct list_element *new_el; 228 int i; 229 nthreadsrunning = 0; 230 srand(time(0)); 231 for (i = 0; i < RCU_Q_LEN; i++) { 232 new_el = g_new(struct list_element, 1); 233 TEST_LIST_INSERT_HEAD_RCU(&Q_list_head, new_el, entry); 234 } 235 qemu_mutex_lock(&counts_mutex); 236 n_nodes += RCU_Q_LEN; 237 qemu_mutex_unlock(&counts_mutex); 238 } 239 240 static void rcu_qtest_run(int duration, int nreaders) 241 { 242 int nthreads = nreaders + 1; 243 while (atomic_read(&nthreadsrunning) < nthreads) { 244 g_usleep(1000); 245 } 246 247 atomic_set(&goflag, GOFLAG_RUN); 248 sleep(duration); 249 atomic_set(&goflag, GOFLAG_STOP); 250 wait_all_threads(); 251 } 252 253 254 static void rcu_qtest(const char *test, int duration, int nreaders) 255 { 256 int i; 257 long long n_removed_local = 0; 258 259 struct list_element *el, *prev_el; 260 261 rcu_qtest_init(); 262 for (i = 0; i < nreaders; i++) { 263 create_thread(rcu_q_reader); 264 } 265 create_thread(rcu_q_updater); 266 rcu_qtest_run(duration, nreaders); 267 268 TEST_LIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) { 269 TEST_LIST_REMOVE_RCU(prev_el, entry); 270 call_rcu1(&prev_el->rcu, reclaim_list_el); 271 n_removed_local++; 272 } 273 qemu_mutex_lock(&counts_mutex); 274 n_nodes_removed += n_removed_local; 275 qemu_mutex_unlock(&counts_mutex); 276 synchronize_rcu(); 277 while (n_nodes_removed > n_reclaims) { 278 g_usleep(100); 279 synchronize_rcu(); 280 } 281 if (g_test_in_charge) { 282 g_assert_cmpint(n_nodes_removed, ==, n_reclaims); 283 } else { 284 printf("%s: %d readers; 1 updater; nodes read: " \ 285 "%lld, nodes removed: %lld; nodes reclaimed: %lld\n", 286 test, nthreadsrunning - 1, n_reads, n_nodes_removed, n_reclaims); 287 exit(0); 288 } 289 } 290 291 static void usage(int argc, char *argv[]) 292 { 293 fprintf(stderr, "Usage: %s duration nreaders\n", argv[0]); 294 exit(-1); 295 } 296 297 static int gtest_seconds; 298 299 static void gtest_rcuq_one(void) 300 { 301 rcu_qtest("rcuqtest", gtest_seconds / 4, 1); 302 } 303 304 static void gtest_rcuq_few(void) 305 { 306 rcu_qtest("rcuqtest", gtest_seconds / 4, 5); 307 } 308 309 static void gtest_rcuq_many(void) 310 { 311 rcu_qtest("rcuqtest", gtest_seconds / 2, 20); 312 } 313 314 315 int main(int argc, char *argv[]) 316 { 317 int duration = 0, readers = 0; 318 319 qemu_mutex_init(&counts_mutex); 320 if (argc >= 2) { 321 if (argv[1][0] == '-') { 322 g_test_init(&argc, &argv, NULL); 323 if (g_test_quick()) { 324 gtest_seconds = 4; 325 } else { 326 gtest_seconds = 20; 327 } 328 g_test_add_func("/rcu/"TEST_NAME"/single-threaded", gtest_rcuq_one); 329 g_test_add_func("/rcu/"TEST_NAME"/short-few", gtest_rcuq_few); 330 g_test_add_func("/rcu/"TEST_NAME"/long-many", gtest_rcuq_many); 331 g_test_in_charge = 1; 332 return g_test_run(); 333 } 334 duration = strtoul(argv[1], NULL, 0); 335 } 336 if (argc >= 3) { 337 readers = strtoul(argv[2], NULL, 0); 338 } 339 if (duration && readers) { 340 rcu_qtest(argv[0], duration, readers); 341 return 0; 342 } 343 344 usage(argc, argv); 345 return -1; 346 } 347