1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Read-Copy Update module-based scalability-test facility 4 * 5 * Copyright (C) IBM Corporation, 2015 6 * 7 * Authors: Paul E. McKenney <paulmck@linux.ibm.com> 8 */ 9 10 #define pr_fmt(fmt) fmt 11 12 #include <linux/types.h> 13 #include <linux/kernel.h> 14 #include <linux/init.h> 15 #include <linux/mm.h> 16 #include <linux/module.h> 17 #include <linux/kthread.h> 18 #include <linux/err.h> 19 #include <linux/spinlock.h> 20 #include <linux/smp.h> 21 #include <linux/rcupdate.h> 22 #include <linux/interrupt.h> 23 #include <linux/sched.h> 24 #include <uapi/linux/sched/types.h> 25 #include <linux/atomic.h> 26 #include <linux/bitops.h> 27 #include <linux/completion.h> 28 #include <linux/moduleparam.h> 29 #include <linux/percpu.h> 30 #include <linux/notifier.h> 31 #include <linux/reboot.h> 32 #include <linux/freezer.h> 33 #include <linux/cpu.h> 34 #include <linux/delay.h> 35 #include <linux/stat.h> 36 #include <linux/srcu.h> 37 #include <linux/slab.h> 38 #include <asm/byteorder.h> 39 #include <linux/torture.h> 40 #include <linux/vmalloc.h> 41 #include <linux/rcupdate_trace.h> 42 43 #include "rcu.h" 44 45 MODULE_LICENSE("GPL"); 46 MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>"); 47 48 #define SCALE_FLAG "-scale:" 49 #define SCALEOUT_STRING(s) \ 50 pr_alert("%s" SCALE_FLAG " %s\n", scale_type, s) 51 #define VERBOSE_SCALEOUT_STRING(s) \ 52 do { if (verbose) pr_alert("%s" SCALE_FLAG " %s\n", scale_type, s); } while (0) 53 #define SCALEOUT_ERRSTRING(s) \ 54 pr_alert("%s" SCALE_FLAG "!!! %s\n", scale_type, s) 55 56 /* 57 * The intended use cases for the nreaders and nwriters module parameters 58 * are as follows: 59 * 60 * 1. Specify only the nr_cpus kernel boot parameter. This will 61 * set both nreaders and nwriters to the value specified by 62 * nr_cpus for a mixed reader/writer test. 63 * 64 * 2. Specify the nr_cpus kernel boot parameter, but set 65 * rcuscale.nreaders to zero. This will set nwriters to the 66 * value specified by nr_cpus for an update-only test. 67 * 68 * 3. Specify the nr_cpus kernel boot parameter, but set 69 * rcuscale.nwriters to zero. This will set nreaders to the 70 * value specified by nr_cpus for a read-only test. 71 * 72 * Various other use cases may of course be specified. 73 * 74 * Note that this test's readers are intended only as a test load for 75 * the writers. The reader scalability statistics will be overly 76 * pessimistic due to the per-critical-section interrupt disabling, 77 * test-end checks, and the pair of calls through pointers. 78 */ 79 80 #ifdef MODULE 81 # define RCUSCALE_SHUTDOWN 0 82 #else 83 # define RCUSCALE_SHUTDOWN 1 84 #endif 85 86 torture_param(bool, gp_async, false, "Use asynchronous GP wait primitives"); 87 torture_param(int, gp_async_max, 1000, "Max # outstanding waits per reader"); 88 torture_param(bool, gp_exp, false, "Use expedited GP wait primitives"); 89 torture_param(int, holdoff, 10, "Holdoff time before test start (s)"); 90 torture_param(int, nreaders, -1, "Number of RCU reader threads"); 91 torture_param(int, nwriters, -1, "Number of RCU updater threads"); 92 torture_param(bool, shutdown, RCUSCALE_SHUTDOWN, 93 "Shutdown at end of scalability tests."); 94 torture_param(int, verbose, 1, "Enable verbose debugging printk()s"); 95 torture_param(int, writer_holdoff, 0, "Holdoff (us) between GPs, zero to disable"); 96 torture_param(int, kfree_rcu_test, 0, "Do we run a kfree_rcu() scale test?"); 97 torture_param(int, kfree_mult, 1, "Multiple of kfree_obj size to allocate."); 98 99 static char *scale_type = "rcu"; 100 module_param(scale_type, charp, 0444); 101 MODULE_PARM_DESC(scale_type, "Type of RCU to scalability-test (rcu, srcu, ...)"); 102 103 static int nrealreaders; 104 static int nrealwriters; 105 static struct task_struct **writer_tasks; 106 static struct task_struct **reader_tasks; 107 static struct task_struct *shutdown_task; 108 109 static u64 **writer_durations; 110 static int *writer_n_durations; 111 static atomic_t n_rcu_scale_reader_started; 112 static atomic_t n_rcu_scale_writer_started; 113 static atomic_t n_rcu_scale_writer_finished; 114 static wait_queue_head_t shutdown_wq; 115 static u64 t_rcu_scale_writer_started; 116 static u64 t_rcu_scale_writer_finished; 117 static unsigned long b_rcu_gp_test_started; 118 static unsigned long b_rcu_gp_test_finished; 119 static DEFINE_PER_CPU(atomic_t, n_async_inflight); 120 121 #define MAX_MEAS 10000 122 #define MIN_MEAS 100 123 124 /* 125 * Operations vector for selecting different types of tests. 126 */ 127 128 struct rcu_scale_ops { 129 int ptype; 130 void (*init)(void); 131 void (*cleanup)(void); 132 int (*readlock)(void); 133 void (*readunlock)(int idx); 134 unsigned long (*get_gp_seq)(void); 135 unsigned long (*gp_diff)(unsigned long new, unsigned long old); 136 unsigned long (*exp_completed)(void); 137 void (*async)(struct rcu_head *head, rcu_callback_t func); 138 void (*gp_barrier)(void); 139 void (*sync)(void); 140 void (*exp_sync)(void); 141 const char *name; 142 }; 143 144 static struct rcu_scale_ops *cur_ops; 145 146 /* 147 * Definitions for rcu scalability testing. 148 */ 149 150 static int rcu_scale_read_lock(void) __acquires(RCU) 151 { 152 rcu_read_lock(); 153 return 0; 154 } 155 156 static void rcu_scale_read_unlock(int idx) __releases(RCU) 157 { 158 rcu_read_unlock(); 159 } 160 161 static unsigned long __maybe_unused rcu_no_completed(void) 162 { 163 return 0; 164 } 165 166 static void rcu_sync_scale_init(void) 167 { 168 } 169 170 static struct rcu_scale_ops rcu_ops = { 171 .ptype = RCU_FLAVOR, 172 .init = rcu_sync_scale_init, 173 .readlock = rcu_scale_read_lock, 174 .readunlock = rcu_scale_read_unlock, 175 .get_gp_seq = rcu_get_gp_seq, 176 .gp_diff = rcu_seq_diff, 177 .exp_completed = rcu_exp_batches_completed, 178 .async = call_rcu, 179 .gp_barrier = rcu_barrier, 180 .sync = synchronize_rcu, 181 .exp_sync = synchronize_rcu_expedited, 182 .name = "rcu" 183 }; 184 185 /* 186 * Definitions for srcu scalability testing. 187 */ 188 189 DEFINE_STATIC_SRCU(srcu_ctl_scale); 190 static struct srcu_struct *srcu_ctlp = &srcu_ctl_scale; 191 192 static int srcu_scale_read_lock(void) __acquires(srcu_ctlp) 193 { 194 return srcu_read_lock(srcu_ctlp); 195 } 196 197 static void srcu_scale_read_unlock(int idx) __releases(srcu_ctlp) 198 { 199 srcu_read_unlock(srcu_ctlp, idx); 200 } 201 202 static unsigned long srcu_scale_completed(void) 203 { 204 return srcu_batches_completed(srcu_ctlp); 205 } 206 207 static void srcu_call_rcu(struct rcu_head *head, rcu_callback_t func) 208 { 209 call_srcu(srcu_ctlp, head, func); 210 } 211 212 static void srcu_rcu_barrier(void) 213 { 214 srcu_barrier(srcu_ctlp); 215 } 216 217 static void srcu_scale_synchronize(void) 218 { 219 synchronize_srcu(srcu_ctlp); 220 } 221 222 static void srcu_scale_synchronize_expedited(void) 223 { 224 synchronize_srcu_expedited(srcu_ctlp); 225 } 226 227 static struct rcu_scale_ops srcu_ops = { 228 .ptype = SRCU_FLAVOR, 229 .init = rcu_sync_scale_init, 230 .readlock = srcu_scale_read_lock, 231 .readunlock = srcu_scale_read_unlock, 232 .get_gp_seq = srcu_scale_completed, 233 .gp_diff = rcu_seq_diff, 234 .exp_completed = srcu_scale_completed, 235 .async = srcu_call_rcu, 236 .gp_barrier = srcu_rcu_barrier, 237 .sync = srcu_scale_synchronize, 238 .exp_sync = srcu_scale_synchronize_expedited, 239 .name = "srcu" 240 }; 241 242 static struct srcu_struct srcud; 243 244 static void srcu_sync_scale_init(void) 245 { 246 srcu_ctlp = &srcud; 247 init_srcu_struct(srcu_ctlp); 248 } 249 250 static void srcu_sync_scale_cleanup(void) 251 { 252 cleanup_srcu_struct(srcu_ctlp); 253 } 254 255 static struct rcu_scale_ops srcud_ops = { 256 .ptype = SRCU_FLAVOR, 257 .init = srcu_sync_scale_init, 258 .cleanup = srcu_sync_scale_cleanup, 259 .readlock = srcu_scale_read_lock, 260 .readunlock = srcu_scale_read_unlock, 261 .get_gp_seq = srcu_scale_completed, 262 .gp_diff = rcu_seq_diff, 263 .exp_completed = srcu_scale_completed, 264 .async = srcu_call_rcu, 265 .gp_barrier = srcu_rcu_barrier, 266 .sync = srcu_scale_synchronize, 267 .exp_sync = srcu_scale_synchronize_expedited, 268 .name = "srcud" 269 }; 270 271 #ifdef CONFIG_TASKS_RCU 272 273 /* 274 * Definitions for RCU-tasks scalability testing. 275 */ 276 277 static int tasks_scale_read_lock(void) 278 { 279 return 0; 280 } 281 282 static void tasks_scale_read_unlock(int idx) 283 { 284 } 285 286 static struct rcu_scale_ops tasks_ops = { 287 .ptype = RCU_TASKS_FLAVOR, 288 .init = rcu_sync_scale_init, 289 .readlock = tasks_scale_read_lock, 290 .readunlock = tasks_scale_read_unlock, 291 .get_gp_seq = rcu_no_completed, 292 .gp_diff = rcu_seq_diff, 293 .async = call_rcu_tasks, 294 .gp_barrier = rcu_barrier_tasks, 295 .sync = synchronize_rcu_tasks, 296 .exp_sync = synchronize_rcu_tasks, 297 .name = "tasks" 298 }; 299 300 #define TASKS_OPS &tasks_ops, 301 302 #else // #ifdef CONFIG_TASKS_RCU 303 304 #define TASKS_OPS 305 306 #endif // #else // #ifdef CONFIG_TASKS_RCU 307 308 #ifdef CONFIG_TASKS_TRACE_RCU 309 310 /* 311 * Definitions for RCU-tasks-trace scalability testing. 312 */ 313 314 static int tasks_trace_scale_read_lock(void) 315 { 316 rcu_read_lock_trace(); 317 return 0; 318 } 319 320 static void tasks_trace_scale_read_unlock(int idx) 321 { 322 rcu_read_unlock_trace(); 323 } 324 325 static struct rcu_scale_ops tasks_tracing_ops = { 326 .ptype = RCU_TASKS_FLAVOR, 327 .init = rcu_sync_scale_init, 328 .readlock = tasks_trace_scale_read_lock, 329 .readunlock = tasks_trace_scale_read_unlock, 330 .get_gp_seq = rcu_no_completed, 331 .gp_diff = rcu_seq_diff, 332 .async = call_rcu_tasks_trace, 333 .gp_barrier = rcu_barrier_tasks_trace, 334 .sync = synchronize_rcu_tasks_trace, 335 .exp_sync = synchronize_rcu_tasks_trace, 336 .name = "tasks-tracing" 337 }; 338 339 #define TASKS_TRACING_OPS &tasks_tracing_ops, 340 341 #else // #ifdef CONFIG_TASKS_TRACE_RCU 342 343 #define TASKS_TRACING_OPS 344 345 #endif // #else // #ifdef CONFIG_TASKS_TRACE_RCU 346 347 static unsigned long rcuscale_seq_diff(unsigned long new, unsigned long old) 348 { 349 if (!cur_ops->gp_diff) 350 return new - old; 351 return cur_ops->gp_diff(new, old); 352 } 353 354 /* 355 * If scalability tests complete, wait for shutdown to commence. 356 */ 357 static void rcu_scale_wait_shutdown(void) 358 { 359 cond_resched_tasks_rcu_qs(); 360 if (atomic_read(&n_rcu_scale_writer_finished) < nrealwriters) 361 return; 362 while (!torture_must_stop()) 363 schedule_timeout_uninterruptible(1); 364 } 365 366 /* 367 * RCU scalability reader kthread. Repeatedly does empty RCU read-side 368 * critical section, minimizing update-side interference. However, the 369 * point of this test is not to evaluate reader scalability, but instead 370 * to serve as a test load for update-side scalability testing. 371 */ 372 static int 373 rcu_scale_reader(void *arg) 374 { 375 unsigned long flags; 376 int idx; 377 long me = (long)arg; 378 379 VERBOSE_SCALEOUT_STRING("rcu_scale_reader task started"); 380 set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids)); 381 set_user_nice(current, MAX_NICE); 382 atomic_inc(&n_rcu_scale_reader_started); 383 384 do { 385 local_irq_save(flags); 386 idx = cur_ops->readlock(); 387 cur_ops->readunlock(idx); 388 local_irq_restore(flags); 389 rcu_scale_wait_shutdown(); 390 } while (!torture_must_stop()); 391 torture_kthread_stopping("rcu_scale_reader"); 392 return 0; 393 } 394 395 /* 396 * Callback function for asynchronous grace periods from rcu_scale_writer(). 397 */ 398 static void rcu_scale_async_cb(struct rcu_head *rhp) 399 { 400 atomic_dec(this_cpu_ptr(&n_async_inflight)); 401 kfree(rhp); 402 } 403 404 /* 405 * RCU scale writer kthread. Repeatedly does a grace period. 406 */ 407 static int 408 rcu_scale_writer(void *arg) 409 { 410 int i = 0; 411 int i_max; 412 long me = (long)arg; 413 struct rcu_head *rhp = NULL; 414 bool started = false, done = false, alldone = false; 415 u64 t; 416 u64 *wdp; 417 u64 *wdpp = writer_durations[me]; 418 419 VERBOSE_SCALEOUT_STRING("rcu_scale_writer task started"); 420 WARN_ON(!wdpp); 421 set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids)); 422 sched_set_fifo_low(current); 423 424 if (holdoff) 425 schedule_timeout_uninterruptible(holdoff * HZ); 426 427 /* 428 * Wait until rcu_end_inkernel_boot() is called for normal GP tests 429 * so that RCU is not always expedited for normal GP tests. 430 * The system_state test is approximate, but works well in practice. 431 */ 432 while (!gp_exp && system_state != SYSTEM_RUNNING) 433 schedule_timeout_uninterruptible(1); 434 435 t = ktime_get_mono_fast_ns(); 436 if (atomic_inc_return(&n_rcu_scale_writer_started) >= nrealwriters) { 437 t_rcu_scale_writer_started = t; 438 if (gp_exp) { 439 b_rcu_gp_test_started = 440 cur_ops->exp_completed() / 2; 441 } else { 442 b_rcu_gp_test_started = cur_ops->get_gp_seq(); 443 } 444 } 445 446 do { 447 if (writer_holdoff) 448 udelay(writer_holdoff); 449 wdp = &wdpp[i]; 450 *wdp = ktime_get_mono_fast_ns(); 451 if (gp_async) { 452 retry: 453 if (!rhp) 454 rhp = kmalloc(sizeof(*rhp), GFP_KERNEL); 455 if (rhp && atomic_read(this_cpu_ptr(&n_async_inflight)) < gp_async_max) { 456 atomic_inc(this_cpu_ptr(&n_async_inflight)); 457 cur_ops->async(rhp, rcu_scale_async_cb); 458 rhp = NULL; 459 } else if (!kthread_should_stop()) { 460 cur_ops->gp_barrier(); 461 goto retry; 462 } else { 463 kfree(rhp); /* Because we are stopping. */ 464 } 465 } else if (gp_exp) { 466 cur_ops->exp_sync(); 467 } else { 468 cur_ops->sync(); 469 } 470 t = ktime_get_mono_fast_ns(); 471 *wdp = t - *wdp; 472 i_max = i; 473 if (!started && 474 atomic_read(&n_rcu_scale_writer_started) >= nrealwriters) 475 started = true; 476 if (!done && i >= MIN_MEAS) { 477 done = true; 478 sched_set_normal(current, 0); 479 pr_alert("%s%s rcu_scale_writer %ld has %d measurements\n", 480 scale_type, SCALE_FLAG, me, MIN_MEAS); 481 if (atomic_inc_return(&n_rcu_scale_writer_finished) >= 482 nrealwriters) { 483 schedule_timeout_interruptible(10); 484 rcu_ftrace_dump(DUMP_ALL); 485 SCALEOUT_STRING("Test complete"); 486 t_rcu_scale_writer_finished = t; 487 if (gp_exp) { 488 b_rcu_gp_test_finished = 489 cur_ops->exp_completed() / 2; 490 } else { 491 b_rcu_gp_test_finished = 492 cur_ops->get_gp_seq(); 493 } 494 if (shutdown) { 495 smp_mb(); /* Assign before wake. */ 496 wake_up(&shutdown_wq); 497 } 498 } 499 } 500 if (done && !alldone && 501 atomic_read(&n_rcu_scale_writer_finished) >= nrealwriters) 502 alldone = true; 503 if (started && !alldone && i < MAX_MEAS - 1) 504 i++; 505 rcu_scale_wait_shutdown(); 506 } while (!torture_must_stop()); 507 if (gp_async) { 508 cur_ops->gp_barrier(); 509 } 510 writer_n_durations[me] = i_max + 1; 511 torture_kthread_stopping("rcu_scale_writer"); 512 return 0; 513 } 514 515 static void 516 rcu_scale_print_module_parms(struct rcu_scale_ops *cur_ops, const char *tag) 517 { 518 pr_alert("%s" SCALE_FLAG 519 "--- %s: nreaders=%d nwriters=%d verbose=%d shutdown=%d\n", 520 scale_type, tag, nrealreaders, nrealwriters, verbose, shutdown); 521 } 522 523 static void 524 rcu_scale_cleanup(void) 525 { 526 int i; 527 int j; 528 int ngps = 0; 529 u64 *wdp; 530 u64 *wdpp; 531 532 /* 533 * Would like warning at start, but everything is expedited 534 * during the mid-boot phase, so have to wait till the end. 535 */ 536 if (rcu_gp_is_expedited() && !rcu_gp_is_normal() && !gp_exp) 537 SCALEOUT_ERRSTRING("All grace periods expedited, no normal ones to measure!"); 538 if (rcu_gp_is_normal() && gp_exp) 539 SCALEOUT_ERRSTRING("All grace periods normal, no expedited ones to measure!"); 540 if (gp_exp && gp_async) 541 SCALEOUT_ERRSTRING("No expedited async GPs, so went with async!"); 542 543 if (torture_cleanup_begin()) 544 return; 545 if (!cur_ops) { 546 torture_cleanup_end(); 547 return; 548 } 549 550 if (reader_tasks) { 551 for (i = 0; i < nrealreaders; i++) 552 torture_stop_kthread(rcu_scale_reader, 553 reader_tasks[i]); 554 kfree(reader_tasks); 555 } 556 557 if (writer_tasks) { 558 for (i = 0; i < nrealwriters; i++) { 559 torture_stop_kthread(rcu_scale_writer, 560 writer_tasks[i]); 561 if (!writer_n_durations) 562 continue; 563 j = writer_n_durations[i]; 564 pr_alert("%s%s writer %d gps: %d\n", 565 scale_type, SCALE_FLAG, i, j); 566 ngps += j; 567 } 568 pr_alert("%s%s start: %llu end: %llu duration: %llu gps: %d batches: %ld\n", 569 scale_type, SCALE_FLAG, 570 t_rcu_scale_writer_started, t_rcu_scale_writer_finished, 571 t_rcu_scale_writer_finished - 572 t_rcu_scale_writer_started, 573 ngps, 574 rcuscale_seq_diff(b_rcu_gp_test_finished, 575 b_rcu_gp_test_started)); 576 for (i = 0; i < nrealwriters; i++) { 577 if (!writer_durations) 578 break; 579 if (!writer_n_durations) 580 continue; 581 wdpp = writer_durations[i]; 582 if (!wdpp) 583 continue; 584 for (j = 0; j < writer_n_durations[i]; j++) { 585 wdp = &wdpp[j]; 586 pr_alert("%s%s %4d writer-duration: %5d %llu\n", 587 scale_type, SCALE_FLAG, 588 i, j, *wdp); 589 if (j % 100 == 0) 590 schedule_timeout_uninterruptible(1); 591 } 592 kfree(writer_durations[i]); 593 } 594 kfree(writer_tasks); 595 kfree(writer_durations); 596 kfree(writer_n_durations); 597 } 598 599 /* Do torture-type-specific cleanup operations. */ 600 if (cur_ops->cleanup != NULL) 601 cur_ops->cleanup(); 602 603 torture_cleanup_end(); 604 } 605 606 /* 607 * Return the number if non-negative. If -1, the number of CPUs. 608 * If less than -1, that much less than the number of CPUs, but 609 * at least one. 610 */ 611 static int compute_real(int n) 612 { 613 int nr; 614 615 if (n >= 0) { 616 nr = n; 617 } else { 618 nr = num_online_cpus() + 1 + n; 619 if (nr <= 0) 620 nr = 1; 621 } 622 return nr; 623 } 624 625 /* 626 * RCU scalability shutdown kthread. Just waits to be awakened, then shuts 627 * down system. 628 */ 629 static int 630 rcu_scale_shutdown(void *arg) 631 { 632 wait_event(shutdown_wq, 633 atomic_read(&n_rcu_scale_writer_finished) >= nrealwriters); 634 smp_mb(); /* Wake before output. */ 635 rcu_scale_cleanup(); 636 kernel_power_off(); 637 return -EINVAL; 638 } 639 640 /* 641 * kfree_rcu() scalability tests: Start a kfree_rcu() loop on all CPUs for number 642 * of iterations and measure total time and number of GP for all iterations to complete. 643 */ 644 645 torture_param(int, kfree_nthreads, -1, "Number of threads running loops of kfree_rcu()."); 646 torture_param(int, kfree_alloc_num, 8000, "Number of allocations and frees done in an iteration."); 647 torture_param(int, kfree_loops, 10, "Number of loops doing kfree_alloc_num allocations and frees."); 648 torture_param(bool, kfree_rcu_test_double, false, "Do we run a kfree_rcu() double-argument scale test?"); 649 torture_param(bool, kfree_rcu_test_single, false, "Do we run a kfree_rcu() single-argument scale test?"); 650 651 static struct task_struct **kfree_reader_tasks; 652 static int kfree_nrealthreads; 653 static atomic_t n_kfree_scale_thread_started; 654 static atomic_t n_kfree_scale_thread_ended; 655 656 struct kfree_obj { 657 char kfree_obj[8]; 658 struct rcu_head rh; 659 }; 660 661 static int 662 kfree_scale_thread(void *arg) 663 { 664 int i, loop = 0; 665 long me = (long)arg; 666 struct kfree_obj *alloc_ptr; 667 u64 start_time, end_time; 668 long long mem_begin, mem_during = 0; 669 bool kfree_rcu_test_both; 670 DEFINE_TORTURE_RANDOM(tr); 671 672 VERBOSE_SCALEOUT_STRING("kfree_scale_thread task started"); 673 set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids)); 674 set_user_nice(current, MAX_NICE); 675 kfree_rcu_test_both = (kfree_rcu_test_single == kfree_rcu_test_double); 676 677 start_time = ktime_get_mono_fast_ns(); 678 679 if (atomic_inc_return(&n_kfree_scale_thread_started) >= kfree_nrealthreads) { 680 if (gp_exp) 681 b_rcu_gp_test_started = cur_ops->exp_completed() / 2; 682 else 683 b_rcu_gp_test_started = cur_ops->get_gp_seq(); 684 } 685 686 do { 687 if (!mem_during) { 688 mem_during = mem_begin = si_mem_available(); 689 } else if (loop % (kfree_loops / 4) == 0) { 690 mem_during = (mem_during + si_mem_available()) / 2; 691 } 692 693 for (i = 0; i < kfree_alloc_num; i++) { 694 alloc_ptr = kmalloc(kfree_mult * sizeof(struct kfree_obj), GFP_KERNEL); 695 if (!alloc_ptr) 696 return -ENOMEM; 697 698 // By default kfree_rcu_test_single and kfree_rcu_test_double are 699 // initialized to false. If both have the same value (false or true) 700 // both are randomly tested, otherwise only the one with value true 701 // is tested. 702 if ((kfree_rcu_test_single && !kfree_rcu_test_double) || 703 (kfree_rcu_test_both && torture_random(&tr) & 0x800)) 704 kfree_rcu(alloc_ptr); 705 else 706 kfree_rcu(alloc_ptr, rh); 707 } 708 709 cond_resched(); 710 } while (!torture_must_stop() && ++loop < kfree_loops); 711 712 if (atomic_inc_return(&n_kfree_scale_thread_ended) >= kfree_nrealthreads) { 713 end_time = ktime_get_mono_fast_ns(); 714 715 if (gp_exp) 716 b_rcu_gp_test_finished = cur_ops->exp_completed() / 2; 717 else 718 b_rcu_gp_test_finished = cur_ops->get_gp_seq(); 719 720 pr_alert("Total time taken by all kfree'ers: %llu ns, loops: %d, batches: %ld, memory footprint: %lldMB\n", 721 (unsigned long long)(end_time - start_time), kfree_loops, 722 rcuscale_seq_diff(b_rcu_gp_test_finished, b_rcu_gp_test_started), 723 (mem_begin - mem_during) >> (20 - PAGE_SHIFT)); 724 725 if (shutdown) { 726 smp_mb(); /* Assign before wake. */ 727 wake_up(&shutdown_wq); 728 } 729 } 730 731 torture_kthread_stopping("kfree_scale_thread"); 732 return 0; 733 } 734 735 static void 736 kfree_scale_cleanup(void) 737 { 738 int i; 739 740 if (torture_cleanup_begin()) 741 return; 742 743 if (kfree_reader_tasks) { 744 for (i = 0; i < kfree_nrealthreads; i++) 745 torture_stop_kthread(kfree_scale_thread, 746 kfree_reader_tasks[i]); 747 kfree(kfree_reader_tasks); 748 } 749 750 torture_cleanup_end(); 751 } 752 753 /* 754 * shutdown kthread. Just waits to be awakened, then shuts down system. 755 */ 756 static int 757 kfree_scale_shutdown(void *arg) 758 { 759 wait_event(shutdown_wq, 760 atomic_read(&n_kfree_scale_thread_ended) >= kfree_nrealthreads); 761 762 smp_mb(); /* Wake before output. */ 763 764 kfree_scale_cleanup(); 765 kernel_power_off(); 766 return -EINVAL; 767 } 768 769 static int __init 770 kfree_scale_init(void) 771 { 772 long i; 773 int firsterr = 0; 774 775 kfree_nrealthreads = compute_real(kfree_nthreads); 776 /* Start up the kthreads. */ 777 if (shutdown) { 778 init_waitqueue_head(&shutdown_wq); 779 firsterr = torture_create_kthread(kfree_scale_shutdown, NULL, 780 shutdown_task); 781 if (torture_init_error(firsterr)) 782 goto unwind; 783 schedule_timeout_uninterruptible(1); 784 } 785 786 pr_alert("kfree object size=%zu\n", kfree_mult * sizeof(struct kfree_obj)); 787 788 kfree_reader_tasks = kcalloc(kfree_nrealthreads, sizeof(kfree_reader_tasks[0]), 789 GFP_KERNEL); 790 if (kfree_reader_tasks == NULL) { 791 firsterr = -ENOMEM; 792 goto unwind; 793 } 794 795 for (i = 0; i < kfree_nrealthreads; i++) { 796 firsterr = torture_create_kthread(kfree_scale_thread, (void *)i, 797 kfree_reader_tasks[i]); 798 if (torture_init_error(firsterr)) 799 goto unwind; 800 } 801 802 while (atomic_read(&n_kfree_scale_thread_started) < kfree_nrealthreads) 803 schedule_timeout_uninterruptible(1); 804 805 torture_init_end(); 806 return 0; 807 808 unwind: 809 torture_init_end(); 810 kfree_scale_cleanup(); 811 return firsterr; 812 } 813 814 static int __init 815 rcu_scale_init(void) 816 { 817 long i; 818 int firsterr = 0; 819 static struct rcu_scale_ops *scale_ops[] = { 820 &rcu_ops, &srcu_ops, &srcud_ops, TASKS_OPS TASKS_TRACING_OPS 821 }; 822 823 if (!torture_init_begin(scale_type, verbose)) 824 return -EBUSY; 825 826 /* Process args and announce that the scalability'er is on the job. */ 827 for (i = 0; i < ARRAY_SIZE(scale_ops); i++) { 828 cur_ops = scale_ops[i]; 829 if (strcmp(scale_type, cur_ops->name) == 0) 830 break; 831 } 832 if (i == ARRAY_SIZE(scale_ops)) { 833 pr_alert("rcu-scale: invalid scale type: \"%s\"\n", scale_type); 834 pr_alert("rcu-scale types:"); 835 for (i = 0; i < ARRAY_SIZE(scale_ops); i++) 836 pr_cont(" %s", scale_ops[i]->name); 837 pr_cont("\n"); 838 firsterr = -EINVAL; 839 cur_ops = NULL; 840 goto unwind; 841 } 842 if (cur_ops->init) 843 cur_ops->init(); 844 845 if (kfree_rcu_test) 846 return kfree_scale_init(); 847 848 nrealwriters = compute_real(nwriters); 849 nrealreaders = compute_real(nreaders); 850 atomic_set(&n_rcu_scale_reader_started, 0); 851 atomic_set(&n_rcu_scale_writer_started, 0); 852 atomic_set(&n_rcu_scale_writer_finished, 0); 853 rcu_scale_print_module_parms(cur_ops, "Start of test"); 854 855 /* Start up the kthreads. */ 856 857 if (shutdown) { 858 init_waitqueue_head(&shutdown_wq); 859 firsterr = torture_create_kthread(rcu_scale_shutdown, NULL, 860 shutdown_task); 861 if (torture_init_error(firsterr)) 862 goto unwind; 863 schedule_timeout_uninterruptible(1); 864 } 865 reader_tasks = kcalloc(nrealreaders, sizeof(reader_tasks[0]), 866 GFP_KERNEL); 867 if (reader_tasks == NULL) { 868 SCALEOUT_ERRSTRING("out of memory"); 869 firsterr = -ENOMEM; 870 goto unwind; 871 } 872 for (i = 0; i < nrealreaders; i++) { 873 firsterr = torture_create_kthread(rcu_scale_reader, (void *)i, 874 reader_tasks[i]); 875 if (torture_init_error(firsterr)) 876 goto unwind; 877 } 878 while (atomic_read(&n_rcu_scale_reader_started) < nrealreaders) 879 schedule_timeout_uninterruptible(1); 880 writer_tasks = kcalloc(nrealwriters, sizeof(reader_tasks[0]), 881 GFP_KERNEL); 882 writer_durations = kcalloc(nrealwriters, sizeof(*writer_durations), 883 GFP_KERNEL); 884 writer_n_durations = 885 kcalloc(nrealwriters, sizeof(*writer_n_durations), 886 GFP_KERNEL); 887 if (!writer_tasks || !writer_durations || !writer_n_durations) { 888 SCALEOUT_ERRSTRING("out of memory"); 889 firsterr = -ENOMEM; 890 goto unwind; 891 } 892 for (i = 0; i < nrealwriters; i++) { 893 writer_durations[i] = 894 kcalloc(MAX_MEAS, sizeof(*writer_durations[i]), 895 GFP_KERNEL); 896 if (!writer_durations[i]) { 897 firsterr = -ENOMEM; 898 goto unwind; 899 } 900 firsterr = torture_create_kthread(rcu_scale_writer, (void *)i, 901 writer_tasks[i]); 902 if (torture_init_error(firsterr)) 903 goto unwind; 904 } 905 torture_init_end(); 906 return 0; 907 908 unwind: 909 torture_init_end(); 910 rcu_scale_cleanup(); 911 if (shutdown) { 912 WARN_ON(!IS_MODULE(CONFIG_RCU_SCALE_TEST)); 913 kernel_power_off(); 914 } 915 return firsterr; 916 } 917 918 module_init(rcu_scale_init); 919 module_exit(rcu_scale_cleanup); 920