| 1 | /* test-fair-rwlock.c |
| 2 | * |
| 3 | */ |
| 4 | |
| 5 | #include <linux/module.h> |
| 6 | #include <linux/proc_fs.h> |
| 7 | #include <linux/sched.h> |
| 8 | #include <linux/timex.h> |
| 9 | #include <linux/fair-rwlock.h> |
| 10 | #include <linux/kthread.h> |
| 11 | #include <linux/delay.h> |
| 12 | #include <linux/hardirq.h> |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/percpu.h> |
| 15 | #include <linux/spinlock.h> |
| 16 | #include <asm/ptrace.h> |
| 17 | |
| 18 | #if (NR_CPUS > 64 && (BITS_PER_LONG == 32 || NR_CPUS > 32768)) |
| 19 | #error "fair rwlock needs more bits per long to deal with that many CPUs" |
| 20 | #endif |
| 21 | |
| 22 | /* Test with no contention duration, in seconds */ |
| 23 | #define SINGLE_WRITER_TEST_DURATION 10 |
| 24 | #define SINGLE_READER_TEST_DURATION 10 |
| 25 | #define MULTIPLE_READERS_TEST_DURATION 10 |
| 26 | |
| 27 | /* Test duration, in seconds */ |
| 28 | #define TEST_DURATION 60 |
| 29 | |
| 30 | #define NR_VARS 100 |
| 31 | //#define NR_WRITERS 2 |
| 32 | #define NR_WRITERS 2 |
| 33 | //#define NR_TRYLOCK_WRITERS 2 |
| 34 | #define NR_TRYLOCK_WRITERS 0 |
| 35 | #define NR_READERS 4 |
| 36 | //#define NR_TRYLOCK_READERS 2 |
| 37 | #define NR_TRYLOCK_READERS 0 |
| 38 | |
| 39 | /* |
| 40 | * 1 : test standard rwlock |
| 41 | * 0 : test frwlock |
| 42 | */ |
| 43 | #define TEST_STD_RWLOCK 0 |
| 44 | |
| 45 | /* |
| 46 | * 1 : test with thread and interrupt readers. |
| 47 | * 0 : test only with thread readers. |
| 48 | */ |
| 49 | #define TEST_INTERRUPTS 1 |
| 50 | |
| 51 | #if (TEST_INTERRUPTS) |
| 52 | #define NR_INTERRUPT_READERS 1 |
| 53 | #define NR_TRYLOCK_INTERRUPT_READERS 1 |
| 54 | #else |
| 55 | #define NR_INTERRUPT_READERS 0 |
| 56 | #define NR_TRYLOCK_INTERRUPT_READERS 0 |
| 57 | #endif |
| 58 | |
| 59 | /* |
| 60 | * Writer iteration delay, in us. 0 for busy loop. Caution : writers can |
| 61 | * starve readers. |
| 62 | */ |
| 63 | #define WRITER_DELAY 100 |
| 64 | #define TRYLOCK_WRITER_DELAY 1000 |
| 65 | |
| 66 | /* |
| 67 | * Number of iterations after which a trylock writer fails. |
| 68 | * -1 for infinite loop. |
| 69 | */ |
| 70 | #define TRYLOCK_WRITERS_FAIL_ITER 100 |
| 71 | |
| 72 | /* Thread and interrupt reader delay, in ms */ |
| 73 | #define THREAD_READER_DELAY 0 /* busy loop */ |
| 74 | #define INTERRUPT_READER_DELAY 100 |
| 75 | |
| 76 | static int var[NR_VARS]; |
| 77 | static struct task_struct *reader_threads[NR_READERS]; |
| 78 | static struct task_struct *trylock_reader_threads[NR_TRYLOCK_READERS]; |
| 79 | static struct task_struct *writer_threads[NR_WRITERS]; |
| 80 | static struct task_struct *trylock_writer_threads[NR_TRYLOCK_WRITERS]; |
| 81 | static struct task_struct *interrupt_reader[NR_INTERRUPT_READERS]; |
| 82 | static struct task_struct *trylock_interrupt_reader[NR_TRYLOCK_INTERRUPT_READERS]; |
| 83 | |
| 84 | #if (TEST_STD_RWLOCK) |
| 85 | |
| 86 | static DEFINE_RWLOCK(std_rw_lock); |
| 87 | |
| 88 | #define wrap_read_lock() read_lock(&std_rw_lock) |
| 89 | #define wrap_read_trylock() read_trylock(&std_rw_lock) |
| 90 | #define wrap_read_unlock() read_unlock(&std_rw_lock) |
| 91 | |
| 92 | #define wrap_read_lock_irq() read_lock(&std_rw_lock) |
| 93 | #define wrap_read_trylock_irq() read_trylock(&std_rw_lock) |
| 94 | #define wrap_read_unlock_irq() read_unlock(&std_rw_lock) |
| 95 | |
| 96 | #if (TEST_INTERRUPTS) |
| 97 | #define wrap_write_lock() write_lock_irq(&std_rw_lock) |
| 98 | #define wrap_write_unlock() write_unlock_irq(&std_rw_lock) |
| 99 | #else |
| 100 | #define wrap_write_lock() write_lock(&std_rw_lock) |
| 101 | #define wrap_write_unlock() write_unlock(&std_rw_lock) |
| 102 | #endif |
| 103 | |
| 104 | #else |
| 105 | |
| 106 | static struct fair_rwlock frwlock = { |
| 107 | .value = ATOMIC_LONG_INIT(0), |
| 108 | }; |
| 109 | |
| 110 | #define wrap_read_lock() fair_read_lock(&frwlock) |
| 111 | #define wrap_read_trylock() fair_read_trylock(&frwlock) |
| 112 | #define wrap_read_unlock() fair_read_unlock(&frwlock) |
| 113 | |
| 114 | #define wrap_read_lock_irq() fair_read_lock_irq(&frwlock) |
| 115 | #define wrap_read_trylock_irq() fair_read_trylock_irq(&frwlock) |
| 116 | #define wrap_read_unlock_irq() fair_read_unlock_irq(&frwlock) |
| 117 | |
| 118 | #if (TEST_INTERRUPTS) |
| 119 | #define wrap_write_lock() fair_write_lock_irq(&frwlock) |
| 120 | #define wrap_write_unlock() fair_write_unlock_irq(&frwlock) |
| 121 | #else |
| 122 | #define wrap_write_lock() fair_write_lock(&frwlock) |
| 123 | #define wrap_write_unlock() fair_write_unlock(&frwlock) |
| 124 | #endif |
| 125 | |
| 126 | #endif |
| 127 | |
| 128 | static cycles_t cycles_calibration_min, |
| 129 | cycles_calibration_avg, |
| 130 | cycles_calibration_max; |
| 131 | |
| 132 | static inline cycles_t calibrate_cycles(cycles_t cycles) |
| 133 | { |
| 134 | return cycles - cycles_calibration_avg; |
| 135 | } |
| 136 | |
| 137 | struct proc_dir_entry *pentry = NULL; |
| 138 | |
| 139 | static int reader_thread(void *data) |
| 140 | { |
| 141 | int i; |
| 142 | int prev, cur; |
| 143 | unsigned long iter = 0; |
| 144 | cycles_t time1, time2, delay, delaymax = 0, delaymin = ULLONG_MAX, |
| 145 | delayavg = 0; |
| 146 | |
| 147 | printk("reader_thread/%lu runnning\n", (unsigned long)data); |
| 148 | do { |
| 149 | iter++; |
| 150 | preempt_disable(); /* for get_cycles accuracy */ |
| 151 | rdtsc_barrier(); |
| 152 | time1 = get_cycles(); |
| 153 | rdtsc_barrier(); |
| 154 | |
| 155 | wrap_read_lock(); |
| 156 | |
| 157 | rdtsc_barrier(); |
| 158 | time2 = get_cycles(); |
| 159 | rdtsc_barrier(); |
| 160 | delay = time2 - time1; |
| 161 | delaymax = max(delaymax, delay); |
| 162 | delaymin = min(delaymin, delay); |
| 163 | delayavg += delay; |
| 164 | prev = var[0]; |
| 165 | for (i = 1; i < NR_VARS; i++) { |
| 166 | cur = var[i]; |
| 167 | if (cur != prev) |
| 168 | printk(KERN_ALERT |
| 169 | "Unequal cur %d/prev %d at i %d, iter %lu " |
| 170 | "in thread\n", cur, prev, i, iter); |
| 171 | } |
| 172 | |
| 173 | wrap_read_unlock(); |
| 174 | |
| 175 | preempt_enable(); /* for get_cycles accuracy */ |
| 176 | if (THREAD_READER_DELAY) |
| 177 | msleep(THREAD_READER_DELAY); |
| 178 | } while (!kthread_should_stop()); |
| 179 | if (!iter) { |
| 180 | printk("reader_thread/%lu iterations : %lu", |
| 181 | (unsigned long)data, iter); |
| 182 | } else { |
| 183 | delayavg /= iter; |
| 184 | printk("reader_thread/%lu iterations : %lu, " |
| 185 | "lock delay [min,avg,max] %llu,%llu,%llu cycles\n", |
| 186 | (unsigned long)data, iter, |
| 187 | calibrate_cycles(delaymin), |
| 188 | calibrate_cycles(delayavg), |
| 189 | calibrate_cycles(delaymax)); |
| 190 | } |
| 191 | return 0; |
| 192 | } |
| 193 | |
| 194 | static int trylock_reader_thread(void *data) |
| 195 | { |
| 196 | int i; |
| 197 | int prev, cur; |
| 198 | unsigned long iter = 0, success_iter = 0; |
| 199 | |
| 200 | printk("trylock_reader_thread/%lu runnning\n", (unsigned long)data); |
| 201 | do { |
| 202 | while (!wrap_read_trylock()) |
| 203 | iter++; |
| 204 | success_iter++; |
| 205 | prev = var[0]; |
| 206 | for (i = 1; i < NR_VARS; i++) { |
| 207 | cur = var[i]; |
| 208 | if (cur != prev) |
| 209 | printk(KERN_ALERT |
| 210 | "Unequal cur %d/prev %d at i %d, iter %lu " |
| 211 | "in thread\n", cur, prev, i, iter); |
| 212 | } |
| 213 | wrap_read_unlock(); |
| 214 | if (THREAD_READER_DELAY) |
| 215 | msleep(THREAD_READER_DELAY); |
| 216 | } while (!kthread_should_stop()); |
| 217 | printk("trylock_reader_thread/%lu iterations : %lu, " |
| 218 | "successful iterations : %lu\n", |
| 219 | (unsigned long)data, iter, success_iter); |
| 220 | return 0; |
| 221 | } |
| 222 | |
| 223 | DEFINE_PER_CPU(cycles_t, int_delaymin); |
| 224 | DEFINE_PER_CPU(cycles_t, int_delayavg); |
| 225 | DEFINE_PER_CPU(cycles_t, int_delaymax); |
| 226 | DEFINE_PER_CPU(cycles_t, int_ipi_nr); |
| 227 | |
| 228 | static void interrupt_reader_ipi(void *data) |
| 229 | { |
| 230 | int i; |
| 231 | int prev, cur; |
| 232 | cycles_t time1, time2; |
| 233 | cycles_t *delaymax, *delaymin, *delayavg, *ipi_nr, delay; |
| 234 | |
| 235 | /* |
| 236 | * Skip the ipi caller, not in irq context. |
| 237 | */ |
| 238 | if (!in_irq()) |
| 239 | return; |
| 240 | |
| 241 | delaymax = &per_cpu(int_delaymax, smp_processor_id()); |
| 242 | delaymin = &per_cpu(int_delaymin, smp_processor_id()); |
| 243 | delayavg = &per_cpu(int_delayavg, smp_processor_id()); |
| 244 | ipi_nr = &per_cpu(int_ipi_nr, smp_processor_id()); |
| 245 | |
| 246 | rdtsc_barrier(); |
| 247 | time1 = get_cycles(); |
| 248 | rdtsc_barrier(); |
| 249 | |
| 250 | wrap_read_lock_irq(); |
| 251 | |
| 252 | rdtsc_barrier(); |
| 253 | time2 = get_cycles(); |
| 254 | rdtsc_barrier(); |
| 255 | delay = time2 - time1; |
| 256 | *delaymax = max(*delaymax, delay); |
| 257 | *delaymin = min(*delaymin, delay); |
| 258 | *delayavg += delay; |
| 259 | (*ipi_nr)++; |
| 260 | prev = var[0]; |
| 261 | for (i = 1; i < NR_VARS; i++) { |
| 262 | cur = var[i]; |
| 263 | if (cur != prev) |
| 264 | printk(KERN_ALERT |
| 265 | "Unequal cur %d/prev %d at i %d in interrupt\n", |
| 266 | cur, prev, i); |
| 267 | } |
| 268 | wrap_read_unlock_irq(); |
| 269 | } |
| 270 | |
| 271 | DEFINE_PER_CPU(unsigned long, trylock_int_iter); |
| 272 | DEFINE_PER_CPU(unsigned long, trylock_int_success); |
| 273 | |
| 274 | static void trylock_interrupt_reader_ipi(void *data) |
| 275 | { |
| 276 | int i; |
| 277 | int prev, cur; |
| 278 | |
| 279 | /* |
| 280 | * Skip the ipi caller, not in irq context. |
| 281 | */ |
| 282 | if (!in_irq()) |
| 283 | return; |
| 284 | |
| 285 | per_cpu(trylock_int_iter, smp_processor_id())++; |
| 286 | while (!wrap_read_trylock_irq()) |
| 287 | per_cpu(trylock_int_iter, smp_processor_id())++; |
| 288 | per_cpu(trylock_int_success, smp_processor_id())++; |
| 289 | prev = var[0]; |
| 290 | for (i = 1; i < NR_VARS; i++) { |
| 291 | cur = var[i]; |
| 292 | if (cur != prev) |
| 293 | printk(KERN_ALERT |
| 294 | "Unequal cur %d/prev %d at i %d in interrupt\n", |
| 295 | cur, prev, i); |
| 296 | } |
| 297 | wrap_read_unlock_irq(); |
| 298 | } |
| 299 | |
| 300 | |
| 301 | static int interrupt_reader_thread(void *data) |
| 302 | { |
| 303 | unsigned long iter = 0; |
| 304 | int i; |
| 305 | |
| 306 | for_each_online_cpu(i) { |
| 307 | per_cpu(int_delaymax, i) = 0; |
| 308 | per_cpu(int_delaymin, i) = ULLONG_MAX; |
| 309 | per_cpu(int_delayavg, i) = 0; |
| 310 | per_cpu(int_ipi_nr, i) = 0; |
| 311 | } |
| 312 | do { |
| 313 | iter++; |
| 314 | on_each_cpu(interrupt_reader_ipi, NULL, 0); |
| 315 | if (INTERRUPT_READER_DELAY) |
| 316 | msleep(INTERRUPT_READER_DELAY); |
| 317 | } while (!kthread_should_stop()); |
| 318 | printk("interrupt_reader_thread/%lu iterations : %lu\n", |
| 319 | (unsigned long)data, iter); |
| 320 | for_each_online_cpu(i) { |
| 321 | if (!per_cpu(int_ipi_nr, i)) |
| 322 | continue; |
| 323 | per_cpu(int_delayavg, i) /= per_cpu(int_ipi_nr, i); |
| 324 | printk("interrupt readers on CPU %i, " |
| 325 | "lock delay [min,avg,max] %llu,%llu,%llu cycles\n", |
| 326 | i, |
| 327 | calibrate_cycles(per_cpu(int_delaymin, i)), |
| 328 | calibrate_cycles(per_cpu(int_delayavg, i)), |
| 329 | calibrate_cycles(per_cpu(int_delaymax, i))); |
| 330 | } |
| 331 | return 0; |
| 332 | } |
| 333 | |
| 334 | static int trylock_interrupt_reader_thread(void *data) |
| 335 | { |
| 336 | unsigned long iter = 0; |
| 337 | int i; |
| 338 | |
| 339 | do { |
| 340 | iter++; |
| 341 | on_each_cpu(trylock_interrupt_reader_ipi, NULL, 0); |
| 342 | if (INTERRUPT_READER_DELAY) |
| 343 | msleep(INTERRUPT_READER_DELAY); |
| 344 | } while (!kthread_should_stop()); |
| 345 | printk("trylock_interrupt_reader_thread/%lu iterations : %lu\n", |
| 346 | (unsigned long)data, iter); |
| 347 | for_each_online_cpu(i) { |
| 348 | printk("trylock interrupt readers on CPU %i, " |
| 349 | "iterations %lu, " |
| 350 | "successful iterations : %lu\n", |
| 351 | i, per_cpu(trylock_int_iter, i), |
| 352 | per_cpu(trylock_int_success, i)); |
| 353 | per_cpu(trylock_int_iter, i) = 0; |
| 354 | per_cpu(trylock_int_success, i) = 0; |
| 355 | } |
| 356 | return 0; |
| 357 | } |
| 358 | |
| 359 | static int writer_thread(void *data) |
| 360 | { |
| 361 | int i; |
| 362 | int new; |
| 363 | unsigned long iter = 0; |
| 364 | cycles_t time1, time2, delay, delaymax = 0, delaymin = ULLONG_MAX, |
| 365 | delayavg = 0; |
| 366 | |
| 367 | printk("writer_thread/%lu runnning\n", (unsigned long)data); |
| 368 | do { |
| 369 | iter++; |
| 370 | preempt_disable(); /* for get_cycles accuracy */ |
| 371 | rdtsc_barrier(); |
| 372 | time1 = get_cycles(); |
| 373 | rdtsc_barrier(); |
| 374 | |
| 375 | wrap_write_lock(); |
| 376 | |
| 377 | rdtsc_barrier(); |
| 378 | time2 = get_cycles(); |
| 379 | rdtsc_barrier(); |
| 380 | delay = time2 - time1; |
| 381 | delaymax = max(delaymax, delay); |
| 382 | delaymin = min(delaymin, delay); |
| 383 | delayavg += delay; |
| 384 | new = (int)get_cycles(); |
| 385 | for (i = 0; i < NR_VARS; i++) { |
| 386 | var[i] = new; |
| 387 | } |
| 388 | |
| 389 | wrap_write_unlock(); |
| 390 | |
| 391 | preempt_enable(); /* for get_cycles accuracy */ |
| 392 | if (WRITER_DELAY > 0) |
| 393 | udelay(WRITER_DELAY); |
| 394 | } while (!kthread_should_stop()); |
| 395 | delayavg /= iter; |
| 396 | printk("writer_thread/%lu iterations : %lu, " |
| 397 | "lock delay [min,avg,max] %llu,%llu,%llu cycles\n", |
| 398 | (unsigned long)data, iter, |
| 399 | calibrate_cycles(delaymin), |
| 400 | calibrate_cycles(delayavg), |
| 401 | calibrate_cycles(delaymax)); |
| 402 | return 0; |
| 403 | } |
| 404 | |
| 405 | #if (TEST_STD_RWLOCK) |
| 406 | static int trylock_writer_thread(void *data) |
| 407 | { |
| 408 | int i; |
| 409 | int new; |
| 410 | unsigned long iter = 0, success = 0, fail = 0; |
| 411 | |
| 412 | printk("trylock_writer_thread/%lu runnning\n", (unsigned long)data); |
| 413 | do { |
| 414 | #if (TEST_INTERRUPTS) |
| 415 | /* std write trylock cannot disable interrupts. */ |
| 416 | local_irq_disable(); |
| 417 | #endif |
| 418 | |
| 419 | #if (TRYLOCK_WRITERS_FAIL_ITER == -1) |
| 420 | for (;;) { |
| 421 | iter++; |
| 422 | if (write_trylock(&std_rw_lock)) |
| 423 | goto locked; |
| 424 | } |
| 425 | #else |
| 426 | for (i = 0; i < TRYLOCK_WRITERS_FAIL_ITER; i++) { |
| 427 | iter++; |
| 428 | if (write_trylock(&std_rw_lock)) |
| 429 | goto locked; |
| 430 | } |
| 431 | #endif |
| 432 | fail++; |
| 433 | #if (TEST_INTERRUPTS) |
| 434 | local_irq_enable(); |
| 435 | #endif |
| 436 | goto loop; |
| 437 | locked: |
| 438 | success++; |
| 439 | new = (int)get_cycles(); |
| 440 | for (i = 0; i < NR_VARS; i++) { |
| 441 | var[i] = new; |
| 442 | } |
| 443 | #if (TEST_INTERRUPTS) |
| 444 | write_unlock_irq(&std_rw_lock); |
| 445 | #else |
| 446 | write_unlock(&std_rw_lock); |
| 447 | #endif |
| 448 | loop: |
| 449 | if (TRYLOCK_WRITER_DELAY > 0) |
| 450 | udelay(TRYLOCK_WRITER_DELAY); |
| 451 | } while (!kthread_should_stop()); |
| 452 | printk("trylock_writer_thread/%lu iterations : " |
| 453 | "[try,success,fail after %d try], " |
| 454 | "%lu,%lu,%lu\n", |
| 455 | (unsigned long)data, TRYLOCK_WRITERS_FAIL_ITER, |
| 456 | iter, success, fail); |
| 457 | return 0; |
| 458 | } |
| 459 | |
| 460 | #else /* !TEST_STD_RWLOCK */ |
| 461 | |
| 462 | static int trylock_writer_thread(void *data) |
| 463 | { |
| 464 | int i; |
| 465 | int new; |
| 466 | unsigned long iter = 0, success = 0, fail = 0; |
| 467 | |
| 468 | printk("trylock_writer_thread/%lu runnning\n", (unsigned long)data); |
| 469 | do { |
| 470 | iter++; |
| 471 | #if (TEST_INTERRUPTS) |
| 472 | if (fair_write_trylock_irq_else_subscribe(&frwlock)) |
| 473 | #else |
| 474 | if (fair_write_trylock_else_subscribe(&frwlock)) |
| 475 | #endif |
| 476 | goto locked; |
| 477 | |
| 478 | #if (TRYLOCK_WRITERS_FAIL_ITER == -1) |
| 479 | for (;;) { |
| 480 | iter++; |
| 481 | #if (TEST_INTERRUPTS) |
| 482 | if (fair_write_trylock_irq_subscribed(&frwlock)) |
| 483 | #else |
| 484 | if (fair_write_trylock_subscribed(&frwlock)) |
| 485 | #endif |
| 486 | goto locked; |
| 487 | } |
| 488 | #else |
| 489 | for (i = 0; i < TRYLOCK_WRITERS_FAIL_ITER - 1; i++) { |
| 490 | iter++; |
| 491 | #if (TEST_INTERRUPTS) |
| 492 | if (fair_write_trylock_irq_subscribed(&frwlock)) |
| 493 | #else |
| 494 | if (fair_write_trylock_subscribed(&frwlock)) |
| 495 | #endif |
| 496 | goto locked; |
| 497 | } |
| 498 | #endif |
| 499 | fail++; |
| 500 | fair_write_unsubscribe(&frwlock); |
| 501 | goto loop; |
| 502 | locked: |
| 503 | success++; |
| 504 | new = (int)get_cycles(); |
| 505 | for (i = 0; i < NR_VARS; i++) { |
| 506 | var[i] = new; |
| 507 | } |
| 508 | #if (TEST_INTERRUPTS) |
| 509 | fair_write_unlock_irq(&frwlock); |
| 510 | #else |
| 511 | fair_write_unlock(&frwlock); |
| 512 | #endif |
| 513 | loop: |
| 514 | if (TRYLOCK_WRITER_DELAY > 0) |
| 515 | udelay(TRYLOCK_WRITER_DELAY); |
| 516 | } while (!kthread_should_stop()); |
| 517 | printk("trylock_writer_thread/%lu iterations : " |
| 518 | "[try,success,fail after %d try], " |
| 519 | "%lu,%lu,%lu\n", |
| 520 | (unsigned long)data, TRYLOCK_WRITERS_FAIL_ITER, |
| 521 | iter, success, fail); |
| 522 | return 0; |
| 523 | } |
| 524 | |
| 525 | #endif /* TEST_STD_RWLOCK */ |
| 526 | |
| 527 | static void fair_rwlock_create(void) |
| 528 | { |
| 529 | unsigned long i; |
| 530 | |
| 531 | for (i = 0; i < NR_READERS; i++) { |
| 532 | printk("starting reader thread %lu\n", i); |
| 533 | reader_threads[i] = kthread_run(reader_thread, (void *)i, |
| 534 | "frwlock_reader"); |
| 535 | BUG_ON(!reader_threads[i]); |
| 536 | } |
| 537 | |
| 538 | for (i = 0; i < NR_TRYLOCK_READERS; i++) { |
| 539 | printk("starting trylock reader thread %lu\n", i); |
| 540 | trylock_reader_threads[i] = kthread_run(trylock_reader_thread, |
| 541 | (void *)i, "frwlock_trylock_reader"); |
| 542 | BUG_ON(!trylock_reader_threads[i]); |
| 543 | } |
| 544 | for (i = 0; i < NR_INTERRUPT_READERS; i++) { |
| 545 | printk("starting interrupt reader %lu\n", i); |
| 546 | interrupt_reader[i] = kthread_run(interrupt_reader_thread, |
| 547 | (void *)i, |
| 548 | "frwlock_interrupt_reader"); |
| 549 | } |
| 550 | for (i = 0; i < NR_TRYLOCK_INTERRUPT_READERS; i++) { |
| 551 | printk("starting trylock interrupt reader %lu\n", i); |
| 552 | trylock_interrupt_reader[i] = |
| 553 | kthread_run(trylock_interrupt_reader_thread, |
| 554 | (void *)i, "frwlock_trylock_interrupt_reader"); |
| 555 | } |
| 556 | for (i = 0; i < NR_WRITERS; i++) { |
| 557 | printk("starting writer thread %lu\n", i); |
| 558 | writer_threads[i] = kthread_run(writer_thread, (void *)i, |
| 559 | "frwlock_writer"); |
| 560 | BUG_ON(!writer_threads[i]); |
| 561 | } |
| 562 | for (i = 0; i < NR_TRYLOCK_WRITERS; i++) { |
| 563 | printk("starting trylock writer thread %lu\n", i); |
| 564 | trylock_writer_threads[i] = kthread_run(trylock_writer_thread, |
| 565 | (void *)i, "frwlock_trylock_writer"); |
| 566 | BUG_ON(!trylock_writer_threads[i]); |
| 567 | } |
| 568 | } |
| 569 | |
| 570 | static void fair_rwlock_stop(void) |
| 571 | { |
| 572 | unsigned long i; |
| 573 | |
| 574 | for (i = 0; i < NR_WRITERS; i++) |
| 575 | kthread_stop(writer_threads[i]); |
| 576 | for (i = 0; i < NR_TRYLOCK_WRITERS; i++) |
| 577 | kthread_stop(trylock_writer_threads[i]); |
| 578 | for (i = 0; i < NR_READERS; i++) |
| 579 | kthread_stop(reader_threads[i]); |
| 580 | for (i = 0; i < NR_TRYLOCK_READERS; i++) |
| 581 | kthread_stop(trylock_reader_threads[i]); |
| 582 | for (i = 0; i < NR_INTERRUPT_READERS; i++) |
| 583 | kthread_stop(interrupt_reader[i]); |
| 584 | for (i = 0; i < NR_TRYLOCK_INTERRUPT_READERS; i++) |
| 585 | kthread_stop(trylock_interrupt_reader[i]); |
| 586 | } |
| 587 | |
| 588 | |
| 589 | static void perform_test(const char *name, void (*callback)(void)) |
| 590 | { |
| 591 | printk("%s\n", name); |
| 592 | callback(); |
| 593 | } |
| 594 | |
| 595 | static int my_open(struct inode *inode, struct file *file) |
| 596 | { |
| 597 | unsigned long i; |
| 598 | cycles_t time1, time2, delay; |
| 599 | |
| 600 | printk("** get_cycles calibration **\n"); |
| 601 | cycles_calibration_min = ULLONG_MAX; |
| 602 | cycles_calibration_avg = 0; |
| 603 | cycles_calibration_max = 0; |
| 604 | |
| 605 | local_irq_disable(); |
| 606 | for (i = 0; i < 10; i++) { |
| 607 | rdtsc_barrier(); |
| 608 | time1 = get_cycles(); |
| 609 | rdtsc_barrier(); |
| 610 | rdtsc_barrier(); |
| 611 | time2 = get_cycles(); |
| 612 | rdtsc_barrier(); |
| 613 | delay = time2 - time1; |
| 614 | cycles_calibration_min = min(cycles_calibration_min, delay); |
| 615 | cycles_calibration_avg += delay; |
| 616 | cycles_calibration_max = max(cycles_calibration_max, delay); |
| 617 | } |
| 618 | cycles_calibration_avg /= 10; |
| 619 | local_irq_enable(); |
| 620 | |
| 621 | printk("get_cycles takes [min,avg,max] %llu,%llu,%llu cycles, " |
| 622 | "results calibrated on avg\n", |
| 623 | cycles_calibration_min, |
| 624 | cycles_calibration_avg, |
| 625 | cycles_calibration_max); |
| 626 | |
| 627 | printk("** Single writer test, no contention **\n"); |
| 628 | writer_threads[0] = kthread_run(writer_thread, (void *)0, |
| 629 | "frwlock_writer"); |
| 630 | BUG_ON(!writer_threads[0]); |
| 631 | ssleep(SINGLE_WRITER_TEST_DURATION); |
| 632 | kthread_stop(writer_threads[0]); |
| 633 | |
| 634 | printk("** Single trylock writer test, no contention **\n"); |
| 635 | trylock_writer_threads[0] = kthread_run(trylock_writer_thread, |
| 636 | (void *)0, |
| 637 | "trylock_frwlock_writer"); |
| 638 | BUG_ON(!trylock_writer_threads[0]); |
| 639 | ssleep(SINGLE_WRITER_TEST_DURATION); |
| 640 | kthread_stop(trylock_writer_threads[0]); |
| 641 | |
| 642 | printk("** Single reader test, no contention **\n"); |
| 643 | reader_threads[0] = kthread_run(reader_thread, (void *)0, |
| 644 | "frwlock_reader"); |
| 645 | BUG_ON(!reader_threads[0]); |
| 646 | ssleep(SINGLE_READER_TEST_DURATION); |
| 647 | kthread_stop(reader_threads[0]); |
| 648 | |
| 649 | printk("** Multiple readers test, no contention **\n"); |
| 650 | for (i = 0; i < NR_READERS; i++) { |
| 651 | printk("starting reader thread %lu\n", i); |
| 652 | reader_threads[i] = kthread_run(reader_thread, (void *)i, |
| 653 | "frwlock_reader"); |
| 654 | BUG_ON(!reader_threads[i]); |
| 655 | } |
| 656 | ssleep(SINGLE_READER_TEST_DURATION); |
| 657 | for (i = 0; i < NR_READERS; i++) |
| 658 | kthread_stop(reader_threads[i]); |
| 659 | |
| 660 | printk("** High contention test **\n"); |
| 661 | perform_test("fair-rwlock-create", fair_rwlock_create); |
| 662 | ssleep(TEST_DURATION); |
| 663 | perform_test("fair-rwlock-stop", fair_rwlock_stop); |
| 664 | |
| 665 | return -EPERM; |
| 666 | } |
| 667 | |
| 668 | |
| 669 | static struct file_operations my_operations = { |
| 670 | .open = my_open, |
| 671 | }; |
| 672 | |
| 673 | int init_module(void) |
| 674 | { |
| 675 | pentry = create_proc_entry("testfrwlock", 0444, NULL); |
| 676 | if (pentry) |
| 677 | pentry->proc_fops = &my_operations; |
| 678 | |
| 679 | printk("NR_CPUS : %d\n", NR_CPUS); |
| 680 | printk("THREAD_ROFFSET : %lX\n", THREAD_ROFFSET); |
| 681 | printk("THREAD_RMASK : %lX\n", THREAD_RMASK); |
| 682 | printk("SOFTIRQ_ROFFSET : %lX\n", SOFTIRQ_ROFFSET); |
| 683 | printk("SOFTIRQ_RMASK : %lX\n", SOFTIRQ_RMASK); |
| 684 | printk("HARDIRQ_ROFFSET : %lX\n", HARDIRQ_ROFFSET); |
| 685 | printk("HARDIRQ_RMASK : %lX\n", HARDIRQ_RMASK); |
| 686 | printk("SUBSCRIBERS_WOFFSET : %lX\n", SUBSCRIBERS_WOFFSET); |
| 687 | printk("SUBSCRIBERS_WMASK : %lX\n", SUBSCRIBERS_WMASK); |
| 688 | printk("WRITER_MUTEX : %lX\n", WRITER_MUTEX); |
| 689 | printk("SOFTIRQ_WMASK : %lX\n", SOFTIRQ_WMASK); |
| 690 | printk("HARDIRQ_WMASK : %lX\n", HARDIRQ_WMASK); |
| 691 | |
| 692 | return 0; |
| 693 | } |
| 694 | |
| 695 | void cleanup_module(void) |
| 696 | { |
| 697 | remove_proc_entry("testfrwlock", NULL); |
| 698 | } |
| 699 | |
| 700 | MODULE_LICENSE("GPL"); |
| 701 | MODULE_AUTHOR("Mathieu Desnoyers"); |
| 702 | MODULE_DESCRIPTION("Fair rwlock test"); |