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_DESCRIPTION("Read-Copy Update module-based scalability-test facility"); 46 MODULE_LICENSE("GPL"); 47 MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>"); 48 49 #define SCALE_FLAG "-scale:" 50 #define SCALEOUT_STRING(s) \ 51 pr_alert("%s" SCALE_FLAG " %s\n", scale_type, s) 52 #define VERBOSE_SCALEOUT_STRING(s) \ 53 do { if (verbose) pr_alert("%s" SCALE_FLAG " %s\n", scale_type, s); } while (0) 54 #define SCALEOUT_ERRSTRING(s) \ 55 pr_alert("%s" SCALE_FLAG "!!! %s\n", scale_type, s) 56 57 /* 58 * The intended use cases for the nreaders and nwriters module parameters 59 * are as follows: 60 * 61 * 1. Specify only the nr_cpus kernel boot parameter. This will 62 * set both nreaders and nwriters to the value specified by 63 * nr_cpus for a mixed reader/writer test. 64 * 65 * 2. Specify the nr_cpus kernel boot parameter, but set 66 * rcuscale.nreaders to zero. This will set nwriters to the 67 * value specified by nr_cpus for an update-only test. 68 * 69 * 3. Specify the nr_cpus kernel boot parameter, but set 70 * rcuscale.nwriters to zero. This will set nreaders to the 71 * value specified by nr_cpus for a read-only test. 72 * 73 * Various other use cases may of course be specified. 74 * 75 * Note that this test's readers are intended only as a test load for 76 * the writers. The reader scalability statistics will be overly 77 * pessimistic due to the per-critical-section interrupt disabling, 78 * test-end checks, and the pair of calls through pointers. 79 */ 80 81 #ifdef MODULE 82 # define RCUSCALE_SHUTDOWN 0 83 #else 84 # define RCUSCALE_SHUTDOWN 1 85 #endif 86 87 torture_param(bool, gp_async, false, "Use asynchronous GP wait primitives"); 88 torture_param(int, gp_async_max, 1000, "Max # outstanding waits per writer"); 89 torture_param(bool, gp_exp, false, "Use expedited GP wait primitives"); 90 torture_param(int, holdoff, 10, "Holdoff time before test start (s)"); 91 torture_param(int, minruntime, 0, "Minimum run time (s)"); 92 torture_param(int, nreaders, -1, "Number of RCU reader threads"); 93 torture_param(int, nwriters, -1, "Number of RCU updater threads"); 94 torture_param(bool, shutdown, RCUSCALE_SHUTDOWN, 95 "Shutdown at end of scalability tests."); 96 torture_param(int, verbose, 1, "Enable verbose debugging printk()s"); 97 torture_param(int, writer_holdoff, 0, "Holdoff (us) between GPs, zero to disable"); 98 torture_param(int, writer_holdoff_jiffies, 0, "Holdoff (jiffies) between GPs, zero to disable"); 99 torture_param(int, kfree_rcu_test, 0, "Do we run a kfree_rcu() scale test?"); 100 torture_param(int, kfree_mult, 1, "Multiple of kfree_obj size to allocate."); 101 torture_param(int, kfree_by_call_rcu, 0, "Use call_rcu() to emulate kfree_rcu()?"); 102 103 static char *scale_type = "rcu"; 104 module_param(scale_type, charp, 0444); 105 MODULE_PARM_DESC(scale_type, "Type of RCU to scalability-test (rcu, srcu, ...)"); 106 107 static int nrealreaders; 108 static int nrealwriters; 109 static struct task_struct **writer_tasks; 110 static struct task_struct **reader_tasks; 111 static struct task_struct *shutdown_task; 112 113 static u64 **writer_durations; 114 static int *writer_n_durations; 115 static atomic_t n_rcu_scale_reader_started; 116 static atomic_t n_rcu_scale_writer_started; 117 static atomic_t n_rcu_scale_writer_finished; 118 static wait_queue_head_t shutdown_wq; 119 static u64 t_rcu_scale_writer_started; 120 static u64 t_rcu_scale_writer_finished; 121 static unsigned long b_rcu_gp_test_started; 122 static unsigned long b_rcu_gp_test_finished; 123 static DEFINE_PER_CPU(atomic_t, n_async_inflight); 124 125 #define MAX_MEAS 10000 126 #define MIN_MEAS 100 127 128 /* 129 * Operations vector for selecting different types of tests. 130 */ 131 132 struct rcu_scale_ops { 133 int ptype; 134 void (*init)(void); 135 void (*cleanup)(void); 136 int (*readlock)(void); 137 void (*readunlock)(int idx); 138 unsigned long (*get_gp_seq)(void); 139 unsigned long (*gp_diff)(unsigned long new, unsigned long old); 140 unsigned long (*exp_completed)(void); 141 void (*async)(struct rcu_head *head, rcu_callback_t func); 142 void (*gp_barrier)(void); 143 void (*sync)(void); 144 void (*exp_sync)(void); 145 struct task_struct *(*rso_gp_kthread)(void); 146 const char *name; 147 }; 148 149 static struct rcu_scale_ops *cur_ops; 150 151 /* 152 * Definitions for rcu scalability testing. 153 */ 154 155 static int rcu_scale_read_lock(void) __acquires(RCU) 156 { 157 rcu_read_lock(); 158 return 0; 159 } 160 161 static void rcu_scale_read_unlock(int idx) __releases(RCU) 162 { 163 rcu_read_unlock(); 164 } 165 166 static unsigned long __maybe_unused rcu_no_completed(void) 167 { 168 return 0; 169 } 170 171 static void rcu_sync_scale_init(void) 172 { 173 } 174 175 static struct rcu_scale_ops rcu_ops = { 176 .ptype = RCU_FLAVOR, 177 .init = rcu_sync_scale_init, 178 .readlock = rcu_scale_read_lock, 179 .readunlock = rcu_scale_read_unlock, 180 .get_gp_seq = rcu_get_gp_seq, 181 .gp_diff = rcu_seq_diff, 182 .exp_completed = rcu_exp_batches_completed, 183 .async = call_rcu_hurry, 184 .gp_barrier = rcu_barrier, 185 .sync = synchronize_rcu, 186 .exp_sync = synchronize_rcu_expedited, 187 .name = "rcu" 188 }; 189 190 /* 191 * Definitions for srcu scalability testing. 192 */ 193 194 DEFINE_STATIC_SRCU(srcu_ctl_scale); 195 static struct srcu_struct *srcu_ctlp = &srcu_ctl_scale; 196 197 static int srcu_scale_read_lock(void) __acquires(srcu_ctlp) 198 { 199 return srcu_read_lock(srcu_ctlp); 200 } 201 202 static void srcu_scale_read_unlock(int idx) __releases(srcu_ctlp) 203 { 204 srcu_read_unlock(srcu_ctlp, idx); 205 } 206 207 static unsigned long srcu_scale_completed(void) 208 { 209 return srcu_batches_completed(srcu_ctlp); 210 } 211 212 static void srcu_call_rcu(struct rcu_head *head, rcu_callback_t func) 213 { 214 call_srcu(srcu_ctlp, head, func); 215 } 216 217 static void srcu_rcu_barrier(void) 218 { 219 srcu_barrier(srcu_ctlp); 220 } 221 222 static void srcu_scale_synchronize(void) 223 { 224 synchronize_srcu(srcu_ctlp); 225 } 226 227 static void srcu_scale_synchronize_expedited(void) 228 { 229 synchronize_srcu_expedited(srcu_ctlp); 230 } 231 232 static struct rcu_scale_ops srcu_ops = { 233 .ptype = SRCU_FLAVOR, 234 .init = rcu_sync_scale_init, 235 .readlock = srcu_scale_read_lock, 236 .readunlock = srcu_scale_read_unlock, 237 .get_gp_seq = srcu_scale_completed, 238 .gp_diff = rcu_seq_diff, 239 .exp_completed = srcu_scale_completed, 240 .async = srcu_call_rcu, 241 .gp_barrier = srcu_rcu_barrier, 242 .sync = srcu_scale_synchronize, 243 .exp_sync = srcu_scale_synchronize_expedited, 244 .name = "srcu" 245 }; 246 247 static struct srcu_struct srcud; 248 249 static void srcu_sync_scale_init(void) 250 { 251 srcu_ctlp = &srcud; 252 init_srcu_struct(srcu_ctlp); 253 } 254 255 static void srcu_sync_scale_cleanup(void) 256 { 257 cleanup_srcu_struct(srcu_ctlp); 258 } 259 260 static struct rcu_scale_ops srcud_ops = { 261 .ptype = SRCU_FLAVOR, 262 .init = srcu_sync_scale_init, 263 .cleanup = srcu_sync_scale_cleanup, 264 .readlock = srcu_scale_read_lock, 265 .readunlock = srcu_scale_read_unlock, 266 .get_gp_seq = srcu_scale_completed, 267 .gp_diff = rcu_seq_diff, 268 .exp_completed = srcu_scale_completed, 269 .async = srcu_call_rcu, 270 .gp_barrier = srcu_rcu_barrier, 271 .sync = srcu_scale_synchronize, 272 .exp_sync = srcu_scale_synchronize_expedited, 273 .name = "srcud" 274 }; 275 276 #ifdef CONFIG_TASKS_RCU 277 278 /* 279 * Definitions for RCU-tasks scalability testing. 280 */ 281 282 static int tasks_scale_read_lock(void) 283 { 284 return 0; 285 } 286 287 static void tasks_scale_read_unlock(int idx) 288 { 289 } 290 291 static struct rcu_scale_ops tasks_ops = { 292 .ptype = RCU_TASKS_FLAVOR, 293 .init = rcu_sync_scale_init, 294 .readlock = tasks_scale_read_lock, 295 .readunlock = tasks_scale_read_unlock, 296 .get_gp_seq = rcu_no_completed, 297 .gp_diff = rcu_seq_diff, 298 .async = call_rcu_tasks, 299 .gp_barrier = rcu_barrier_tasks, 300 .sync = synchronize_rcu_tasks, 301 .exp_sync = synchronize_rcu_tasks, 302 .rso_gp_kthread = get_rcu_tasks_gp_kthread, 303 .name = "tasks" 304 }; 305 306 #define TASKS_OPS &tasks_ops, 307 308 #else // #ifdef CONFIG_TASKS_RCU 309 310 #define TASKS_OPS 311 312 #endif // #else // #ifdef CONFIG_TASKS_RCU 313 314 #ifdef CONFIG_TASKS_RUDE_RCU 315 316 /* 317 * Definitions for RCU-tasks-rude scalability testing. 318 */ 319 320 static int tasks_rude_scale_read_lock(void) 321 { 322 return 0; 323 } 324 325 static void tasks_rude_scale_read_unlock(int idx) 326 { 327 } 328 329 static struct rcu_scale_ops tasks_rude_ops = { 330 .ptype = RCU_TASKS_RUDE_FLAVOR, 331 .init = rcu_sync_scale_init, 332 .readlock = tasks_rude_scale_read_lock, 333 .readunlock = tasks_rude_scale_read_unlock, 334 .get_gp_seq = rcu_no_completed, 335 .gp_diff = rcu_seq_diff, 336 .sync = synchronize_rcu_tasks_rude, 337 .exp_sync = synchronize_rcu_tasks_rude, 338 .rso_gp_kthread = get_rcu_tasks_rude_gp_kthread, 339 .name = "tasks-rude" 340 }; 341 342 #define TASKS_RUDE_OPS &tasks_rude_ops, 343 344 #else // #ifdef CONFIG_TASKS_RUDE_RCU 345 346 #define TASKS_RUDE_OPS 347 348 #endif // #else // #ifdef CONFIG_TASKS_RUDE_RCU 349 350 #ifdef CONFIG_TASKS_TRACE_RCU 351 352 /* 353 * Definitions for RCU-tasks-trace scalability testing. 354 */ 355 356 static int tasks_trace_scale_read_lock(void) 357 { 358 rcu_read_lock_trace(); 359 return 0; 360 } 361 362 static void tasks_trace_scale_read_unlock(int idx) 363 { 364 rcu_read_unlock_trace(); 365 } 366 367 static struct rcu_scale_ops tasks_tracing_ops = { 368 .ptype = RCU_TASKS_FLAVOR, 369 .init = rcu_sync_scale_init, 370 .readlock = tasks_trace_scale_read_lock, 371 .readunlock = tasks_trace_scale_read_unlock, 372 .get_gp_seq = rcu_no_completed, 373 .gp_diff = rcu_seq_diff, 374 .async = call_rcu_tasks_trace, 375 .gp_barrier = rcu_barrier_tasks_trace, 376 .sync = synchronize_rcu_tasks_trace, 377 .exp_sync = synchronize_rcu_tasks_trace, 378 .rso_gp_kthread = get_rcu_tasks_trace_gp_kthread, 379 .name = "tasks-tracing" 380 }; 381 382 #define TASKS_TRACING_OPS &tasks_tracing_ops, 383 384 #else // #ifdef CONFIG_TASKS_TRACE_RCU 385 386 #define TASKS_TRACING_OPS 387 388 #endif // #else // #ifdef CONFIG_TASKS_TRACE_RCU 389 390 static unsigned long rcuscale_seq_diff(unsigned long new, unsigned long old) 391 { 392 if (!cur_ops->gp_diff) 393 return new - old; 394 return cur_ops->gp_diff(new, old); 395 } 396 397 /* 398 * If scalability tests complete, wait for shutdown to commence. 399 */ 400 static void rcu_scale_wait_shutdown(void) 401 { 402 cond_resched_tasks_rcu_qs(); 403 if (atomic_read(&n_rcu_scale_writer_finished) < nrealwriters) 404 return; 405 while (!torture_must_stop()) 406 schedule_timeout_uninterruptible(1); 407 } 408 409 /* 410 * RCU scalability reader kthread. Repeatedly does empty RCU read-side 411 * critical section, minimizing update-side interference. However, the 412 * point of this test is not to evaluate reader scalability, but instead 413 * to serve as a test load for update-side scalability testing. 414 */ 415 static int 416 rcu_scale_reader(void *arg) 417 { 418 unsigned long flags; 419 int idx; 420 long me = (long)arg; 421 422 VERBOSE_SCALEOUT_STRING("rcu_scale_reader task started"); 423 set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids)); 424 set_user_nice(current, MAX_NICE); 425 atomic_inc(&n_rcu_scale_reader_started); 426 427 do { 428 local_irq_save(flags); 429 idx = cur_ops->readlock(); 430 cur_ops->readunlock(idx); 431 local_irq_restore(flags); 432 rcu_scale_wait_shutdown(); 433 } while (!torture_must_stop()); 434 torture_kthread_stopping("rcu_scale_reader"); 435 return 0; 436 } 437 438 /* 439 * Callback function for asynchronous grace periods from rcu_scale_writer(). 440 */ 441 static void rcu_scale_async_cb(struct rcu_head *rhp) 442 { 443 atomic_dec(this_cpu_ptr(&n_async_inflight)); 444 kfree(rhp); 445 } 446 447 /* 448 * RCU scale writer kthread. Repeatedly does a grace period. 449 */ 450 static int 451 rcu_scale_writer(void *arg) 452 { 453 int i = 0; 454 int i_max; 455 unsigned long jdone; 456 long me = (long)arg; 457 struct rcu_head *rhp = NULL; 458 bool started = false, done = false, alldone = false; 459 u64 t; 460 DEFINE_TORTURE_RANDOM(tr); 461 u64 *wdp; 462 u64 *wdpp = writer_durations[me]; 463 464 VERBOSE_SCALEOUT_STRING("rcu_scale_writer task started"); 465 WARN_ON(!wdpp); 466 set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids)); 467 current->flags |= PF_NO_SETAFFINITY; 468 sched_set_fifo_low(current); 469 470 if (holdoff) 471 schedule_timeout_idle(holdoff * HZ); 472 473 /* 474 * Wait until rcu_end_inkernel_boot() is called for normal GP tests 475 * so that RCU is not always expedited for normal GP tests. 476 * The system_state test is approximate, but works well in practice. 477 */ 478 while (!gp_exp && system_state != SYSTEM_RUNNING) 479 schedule_timeout_uninterruptible(1); 480 481 t = ktime_get_mono_fast_ns(); 482 if (atomic_inc_return(&n_rcu_scale_writer_started) >= nrealwriters) { 483 t_rcu_scale_writer_started = t; 484 if (gp_exp) { 485 b_rcu_gp_test_started = 486 cur_ops->exp_completed() / 2; 487 } else { 488 b_rcu_gp_test_started = cur_ops->get_gp_seq(); 489 } 490 } 491 492 jdone = jiffies + minruntime * HZ; 493 do { 494 if (writer_holdoff) 495 udelay(writer_holdoff); 496 if (writer_holdoff_jiffies) 497 schedule_timeout_idle(torture_random(&tr) % writer_holdoff_jiffies + 1); 498 wdp = &wdpp[i]; 499 *wdp = ktime_get_mono_fast_ns(); 500 if (gp_async) { 501 retry: 502 if (!rhp) 503 rhp = kmalloc(sizeof(*rhp), GFP_KERNEL); 504 if (rhp && atomic_read(this_cpu_ptr(&n_async_inflight)) < gp_async_max) { 505 atomic_inc(this_cpu_ptr(&n_async_inflight)); 506 cur_ops->async(rhp, rcu_scale_async_cb); 507 rhp = NULL; 508 } else if (!kthread_should_stop()) { 509 cur_ops->gp_barrier(); 510 goto retry; 511 } else { 512 kfree(rhp); /* Because we are stopping. */ 513 } 514 } else if (gp_exp) { 515 cur_ops->exp_sync(); 516 } else { 517 cur_ops->sync(); 518 } 519 t = ktime_get_mono_fast_ns(); 520 *wdp = t - *wdp; 521 i_max = i; 522 if (!started && 523 atomic_read(&n_rcu_scale_writer_started) >= nrealwriters) 524 started = true; 525 if (!done && i >= MIN_MEAS && time_after(jiffies, jdone)) { 526 done = true; 527 sched_set_normal(current, 0); 528 pr_alert("%s%s rcu_scale_writer %ld has %d measurements\n", 529 scale_type, SCALE_FLAG, me, MIN_MEAS); 530 if (atomic_inc_return(&n_rcu_scale_writer_finished) >= 531 nrealwriters) { 532 schedule_timeout_interruptible(10); 533 rcu_ftrace_dump(DUMP_ALL); 534 SCALEOUT_STRING("Test complete"); 535 t_rcu_scale_writer_finished = t; 536 if (gp_exp) { 537 b_rcu_gp_test_finished = 538 cur_ops->exp_completed() / 2; 539 } else { 540 b_rcu_gp_test_finished = 541 cur_ops->get_gp_seq(); 542 } 543 if (shutdown) { 544 smp_mb(); /* Assign before wake. */ 545 wake_up(&shutdown_wq); 546 } 547 } 548 } 549 if (done && !alldone && 550 atomic_read(&n_rcu_scale_writer_finished) >= nrealwriters) 551 alldone = true; 552 if (started && !alldone && i < MAX_MEAS - 1) 553 i++; 554 rcu_scale_wait_shutdown(); 555 } while (!torture_must_stop()); 556 if (gp_async) { 557 cur_ops->gp_barrier(); 558 } 559 writer_n_durations[me] = i_max + 1; 560 torture_kthread_stopping("rcu_scale_writer"); 561 return 0; 562 } 563 564 static void 565 rcu_scale_print_module_parms(struct rcu_scale_ops *cur_ops, const char *tag) 566 { 567 pr_alert("%s" SCALE_FLAG 568 "--- %s: gp_async=%d gp_async_max=%d gp_exp=%d holdoff=%d minruntime=%d nreaders=%d nwriters=%d writer_holdoff=%d writer_holdoff_jiffies=%d verbose=%d shutdown=%d\n", 569 scale_type, tag, gp_async, gp_async_max, gp_exp, holdoff, minruntime, nrealreaders, nrealwriters, writer_holdoff, writer_holdoff_jiffies, verbose, shutdown); 570 } 571 572 /* 573 * Return the number if non-negative. If -1, the number of CPUs. 574 * If less than -1, that much less than the number of CPUs, but 575 * at least one. 576 */ 577 static int compute_real(int n) 578 { 579 int nr; 580 581 if (n >= 0) { 582 nr = n; 583 } else { 584 nr = num_online_cpus() + 1 + n; 585 if (nr <= 0) 586 nr = 1; 587 } 588 return nr; 589 } 590 591 /* 592 * kfree_rcu() scalability tests: Start a kfree_rcu() loop on all CPUs for number 593 * of iterations and measure total time and number of GP for all iterations to complete. 594 */ 595 596 torture_param(int, kfree_nthreads, -1, "Number of threads running loops of kfree_rcu()."); 597 torture_param(int, kfree_alloc_num, 8000, "Number of allocations and frees done in an iteration."); 598 torture_param(int, kfree_loops, 10, "Number of loops doing kfree_alloc_num allocations and frees."); 599 torture_param(bool, kfree_rcu_test_double, false, "Do we run a kfree_rcu() double-argument scale test?"); 600 torture_param(bool, kfree_rcu_test_single, false, "Do we run a kfree_rcu() single-argument scale test?"); 601 602 static struct task_struct **kfree_reader_tasks; 603 static int kfree_nrealthreads; 604 static atomic_t n_kfree_scale_thread_started; 605 static atomic_t n_kfree_scale_thread_ended; 606 static struct task_struct *kthread_tp; 607 static u64 kthread_stime; 608 609 struct kfree_obj { 610 char kfree_obj[8]; 611 struct rcu_head rh; 612 }; 613 614 /* Used if doing RCU-kfree'ing via call_rcu(). */ 615 static void kfree_call_rcu(struct rcu_head *rh) 616 { 617 struct kfree_obj *obj = container_of(rh, struct kfree_obj, rh); 618 619 kfree(obj); 620 } 621 622 static int 623 kfree_scale_thread(void *arg) 624 { 625 int i, loop = 0; 626 long me = (long)arg; 627 struct kfree_obj *alloc_ptr; 628 u64 start_time, end_time; 629 long long mem_begin, mem_during = 0; 630 bool kfree_rcu_test_both; 631 DEFINE_TORTURE_RANDOM(tr); 632 633 VERBOSE_SCALEOUT_STRING("kfree_scale_thread task started"); 634 set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids)); 635 set_user_nice(current, MAX_NICE); 636 kfree_rcu_test_both = (kfree_rcu_test_single == kfree_rcu_test_double); 637 638 start_time = ktime_get_mono_fast_ns(); 639 640 if (atomic_inc_return(&n_kfree_scale_thread_started) >= kfree_nrealthreads) { 641 if (gp_exp) 642 b_rcu_gp_test_started = cur_ops->exp_completed() / 2; 643 else 644 b_rcu_gp_test_started = cur_ops->get_gp_seq(); 645 } 646 647 do { 648 if (!mem_during) { 649 mem_during = mem_begin = si_mem_available(); 650 } else if (loop % (kfree_loops / 4) == 0) { 651 mem_during = (mem_during + si_mem_available()) / 2; 652 } 653 654 for (i = 0; i < kfree_alloc_num; i++) { 655 alloc_ptr = kmalloc(kfree_mult * sizeof(struct kfree_obj), GFP_KERNEL); 656 if (!alloc_ptr) 657 return -ENOMEM; 658 659 if (kfree_by_call_rcu) { 660 call_rcu(&(alloc_ptr->rh), kfree_call_rcu); 661 continue; 662 } 663 664 // By default kfree_rcu_test_single and kfree_rcu_test_double are 665 // initialized to false. If both have the same value (false or true) 666 // both are randomly tested, otherwise only the one with value true 667 // is tested. 668 if ((kfree_rcu_test_single && !kfree_rcu_test_double) || 669 (kfree_rcu_test_both && torture_random(&tr) & 0x800)) 670 kfree_rcu_mightsleep(alloc_ptr); 671 else 672 kfree_rcu(alloc_ptr, rh); 673 } 674 675 cond_resched(); 676 } while (!torture_must_stop() && ++loop < kfree_loops); 677 678 if (atomic_inc_return(&n_kfree_scale_thread_ended) >= kfree_nrealthreads) { 679 end_time = ktime_get_mono_fast_ns(); 680 681 if (gp_exp) 682 b_rcu_gp_test_finished = cur_ops->exp_completed() / 2; 683 else 684 b_rcu_gp_test_finished = cur_ops->get_gp_seq(); 685 686 pr_alert("Total time taken by all kfree'ers: %llu ns, loops: %d, batches: %ld, memory footprint: %lldMB\n", 687 (unsigned long long)(end_time - start_time), kfree_loops, 688 rcuscale_seq_diff(b_rcu_gp_test_finished, b_rcu_gp_test_started), 689 (mem_begin - mem_during) >> (20 - PAGE_SHIFT)); 690 691 if (shutdown) { 692 smp_mb(); /* Assign before wake. */ 693 wake_up(&shutdown_wq); 694 } 695 } 696 697 torture_kthread_stopping("kfree_scale_thread"); 698 return 0; 699 } 700 701 static void 702 kfree_scale_cleanup(void) 703 { 704 int i; 705 706 if (torture_cleanup_begin()) 707 return; 708 709 if (kfree_reader_tasks) { 710 for (i = 0; i < kfree_nrealthreads; i++) 711 torture_stop_kthread(kfree_scale_thread, 712 kfree_reader_tasks[i]); 713 kfree(kfree_reader_tasks); 714 } 715 716 torture_cleanup_end(); 717 } 718 719 /* 720 * shutdown kthread. Just waits to be awakened, then shuts down system. 721 */ 722 static int 723 kfree_scale_shutdown(void *arg) 724 { 725 wait_event_idle(shutdown_wq, 726 atomic_read(&n_kfree_scale_thread_ended) >= kfree_nrealthreads); 727 728 smp_mb(); /* Wake before output. */ 729 730 kfree_scale_cleanup(); 731 kernel_power_off(); 732 return -EINVAL; 733 } 734 735 // Used if doing RCU-kfree'ing via call_rcu(). 736 static unsigned long jiffies_at_lazy_cb; 737 static struct rcu_head lazy_test1_rh; 738 static int rcu_lazy_test1_cb_called; 739 static void call_rcu_lazy_test1(struct rcu_head *rh) 740 { 741 jiffies_at_lazy_cb = jiffies; 742 WRITE_ONCE(rcu_lazy_test1_cb_called, 1); 743 } 744 745 static int __init 746 kfree_scale_init(void) 747 { 748 int firsterr = 0; 749 long i; 750 unsigned long jif_start; 751 unsigned long orig_jif; 752 753 pr_alert("%s" SCALE_FLAG 754 "--- kfree_rcu_test: kfree_mult=%d kfree_by_call_rcu=%d kfree_nthreads=%d kfree_alloc_num=%d kfree_loops=%d kfree_rcu_test_double=%d kfree_rcu_test_single=%d\n", 755 scale_type, kfree_mult, kfree_by_call_rcu, kfree_nthreads, kfree_alloc_num, kfree_loops, kfree_rcu_test_double, kfree_rcu_test_single); 756 757 // Also, do a quick self-test to ensure laziness is as much as 758 // expected. 759 if (kfree_by_call_rcu && !IS_ENABLED(CONFIG_RCU_LAZY)) { 760 pr_alert("CONFIG_RCU_LAZY is disabled, falling back to kfree_rcu() for delayed RCU kfree'ing\n"); 761 kfree_by_call_rcu = 0; 762 } 763 764 if (kfree_by_call_rcu) { 765 /* do a test to check the timeout. */ 766 orig_jif = rcu_get_jiffies_lazy_flush(); 767 768 rcu_set_jiffies_lazy_flush(2 * HZ); 769 rcu_barrier(); 770 771 jif_start = jiffies; 772 jiffies_at_lazy_cb = 0; 773 call_rcu(&lazy_test1_rh, call_rcu_lazy_test1); 774 775 smp_cond_load_relaxed(&rcu_lazy_test1_cb_called, VAL == 1); 776 777 rcu_set_jiffies_lazy_flush(orig_jif); 778 779 if (WARN_ON_ONCE(jiffies_at_lazy_cb - jif_start < 2 * HZ)) { 780 pr_alert("ERROR: call_rcu() CBs are not being lazy as expected!\n"); 781 WARN_ON_ONCE(1); 782 return -1; 783 } 784 785 if (WARN_ON_ONCE(jiffies_at_lazy_cb - jif_start > 3 * HZ)) { 786 pr_alert("ERROR: call_rcu() CBs are being too lazy!\n"); 787 WARN_ON_ONCE(1); 788 return -1; 789 } 790 } 791 792 kfree_nrealthreads = compute_real(kfree_nthreads); 793 /* Start up the kthreads. */ 794 if (shutdown) { 795 init_waitqueue_head(&shutdown_wq); 796 firsterr = torture_create_kthread(kfree_scale_shutdown, NULL, 797 shutdown_task); 798 if (torture_init_error(firsterr)) 799 goto unwind; 800 schedule_timeout_uninterruptible(1); 801 } 802 803 pr_alert("kfree object size=%zu, kfree_by_call_rcu=%d\n", 804 kfree_mult * sizeof(struct kfree_obj), 805 kfree_by_call_rcu); 806 807 kfree_reader_tasks = kcalloc(kfree_nrealthreads, sizeof(kfree_reader_tasks[0]), 808 GFP_KERNEL); 809 if (kfree_reader_tasks == NULL) { 810 firsterr = -ENOMEM; 811 goto unwind; 812 } 813 814 for (i = 0; i < kfree_nrealthreads; i++) { 815 firsterr = torture_create_kthread(kfree_scale_thread, (void *)i, 816 kfree_reader_tasks[i]); 817 if (torture_init_error(firsterr)) 818 goto unwind; 819 } 820 821 while (atomic_read(&n_kfree_scale_thread_started) < kfree_nrealthreads) 822 schedule_timeout_uninterruptible(1); 823 824 torture_init_end(); 825 return 0; 826 827 unwind: 828 torture_init_end(); 829 kfree_scale_cleanup(); 830 return firsterr; 831 } 832 833 static void 834 rcu_scale_cleanup(void) 835 { 836 int i; 837 int j; 838 int ngps = 0; 839 u64 *wdp; 840 u64 *wdpp; 841 842 /* 843 * Would like warning at start, but everything is expedited 844 * during the mid-boot phase, so have to wait till the end. 845 */ 846 if (rcu_gp_is_expedited() && !rcu_gp_is_normal() && !gp_exp) 847 SCALEOUT_ERRSTRING("All grace periods expedited, no normal ones to measure!"); 848 if (rcu_gp_is_normal() && gp_exp) 849 SCALEOUT_ERRSTRING("All grace periods normal, no expedited ones to measure!"); 850 if (gp_exp && gp_async) 851 SCALEOUT_ERRSTRING("No expedited async GPs, so went with async!"); 852 853 // If built-in, just report all of the GP kthread's CPU time. 854 if (IS_BUILTIN(CONFIG_RCU_SCALE_TEST) && !kthread_tp && cur_ops->rso_gp_kthread) 855 kthread_tp = cur_ops->rso_gp_kthread(); 856 if (kthread_tp) { 857 u32 ns; 858 u64 us; 859 860 kthread_stime = kthread_tp->stime - kthread_stime; 861 us = div_u64_rem(kthread_stime, 1000, &ns); 862 pr_info("rcu_scale: Grace-period kthread CPU time: %llu.%03u us\n", us, ns); 863 show_rcu_gp_kthreads(); 864 } 865 if (kfree_rcu_test) { 866 kfree_scale_cleanup(); 867 return; 868 } 869 870 if (torture_cleanup_begin()) 871 return; 872 if (!cur_ops) { 873 torture_cleanup_end(); 874 return; 875 } 876 877 if (reader_tasks) { 878 for (i = 0; i < nrealreaders; i++) 879 torture_stop_kthread(rcu_scale_reader, 880 reader_tasks[i]); 881 kfree(reader_tasks); 882 } 883 884 if (writer_tasks) { 885 for (i = 0; i < nrealwriters; i++) { 886 torture_stop_kthread(rcu_scale_writer, 887 writer_tasks[i]); 888 if (!writer_n_durations) 889 continue; 890 j = writer_n_durations[i]; 891 pr_alert("%s%s writer %d gps: %d\n", 892 scale_type, SCALE_FLAG, i, j); 893 ngps += j; 894 } 895 pr_alert("%s%s start: %llu end: %llu duration: %llu gps: %d batches: %ld\n", 896 scale_type, SCALE_FLAG, 897 t_rcu_scale_writer_started, t_rcu_scale_writer_finished, 898 t_rcu_scale_writer_finished - 899 t_rcu_scale_writer_started, 900 ngps, 901 rcuscale_seq_diff(b_rcu_gp_test_finished, 902 b_rcu_gp_test_started)); 903 for (i = 0; i < nrealwriters; i++) { 904 if (!writer_durations) 905 break; 906 if (!writer_n_durations) 907 continue; 908 wdpp = writer_durations[i]; 909 if (!wdpp) 910 continue; 911 for (j = 0; j < writer_n_durations[i]; j++) { 912 wdp = &wdpp[j]; 913 pr_alert("%s%s %4d writer-duration: %5d %llu\n", 914 scale_type, SCALE_FLAG, 915 i, j, *wdp); 916 if (j % 100 == 0) 917 schedule_timeout_uninterruptible(1); 918 } 919 kfree(writer_durations[i]); 920 } 921 kfree(writer_tasks); 922 kfree(writer_durations); 923 kfree(writer_n_durations); 924 } 925 926 /* Do torture-type-specific cleanup operations. */ 927 if (cur_ops->cleanup != NULL) 928 cur_ops->cleanup(); 929 930 torture_cleanup_end(); 931 } 932 933 /* 934 * RCU scalability shutdown kthread. Just waits to be awakened, then shuts 935 * down system. 936 */ 937 static int 938 rcu_scale_shutdown(void *arg) 939 { 940 wait_event_idle(shutdown_wq, atomic_read(&n_rcu_scale_writer_finished) >= nrealwriters); 941 smp_mb(); /* Wake before output. */ 942 rcu_scale_cleanup(); 943 kernel_power_off(); 944 return -EINVAL; 945 } 946 947 static int __init 948 rcu_scale_init(void) 949 { 950 long i; 951 int firsterr = 0; 952 static struct rcu_scale_ops *scale_ops[] = { 953 &rcu_ops, &srcu_ops, &srcud_ops, TASKS_OPS TASKS_RUDE_OPS TASKS_TRACING_OPS 954 }; 955 956 if (!torture_init_begin(scale_type, verbose)) 957 return -EBUSY; 958 959 /* Process args and announce that the scalability'er is on the job. */ 960 for (i = 0; i < ARRAY_SIZE(scale_ops); i++) { 961 cur_ops = scale_ops[i]; 962 if (strcmp(scale_type, cur_ops->name) == 0) 963 break; 964 } 965 if (i == ARRAY_SIZE(scale_ops)) { 966 pr_alert("rcu-scale: invalid scale type: \"%s\"\n", scale_type); 967 pr_alert("rcu-scale types:"); 968 for (i = 0; i < ARRAY_SIZE(scale_ops); i++) 969 pr_cont(" %s", scale_ops[i]->name); 970 pr_cont("\n"); 971 firsterr = -EINVAL; 972 cur_ops = NULL; 973 goto unwind; 974 } 975 if (cur_ops->init) 976 cur_ops->init(); 977 978 if (cur_ops->rso_gp_kthread) { 979 kthread_tp = cur_ops->rso_gp_kthread(); 980 if (kthread_tp) 981 kthread_stime = kthread_tp->stime; 982 } 983 if (kfree_rcu_test) 984 return kfree_scale_init(); 985 986 nrealwriters = compute_real(nwriters); 987 nrealreaders = compute_real(nreaders); 988 atomic_set(&n_rcu_scale_reader_started, 0); 989 atomic_set(&n_rcu_scale_writer_started, 0); 990 atomic_set(&n_rcu_scale_writer_finished, 0); 991 rcu_scale_print_module_parms(cur_ops, "Start of test"); 992 993 /* Start up the kthreads. */ 994 995 if (shutdown) { 996 init_waitqueue_head(&shutdown_wq); 997 firsterr = torture_create_kthread(rcu_scale_shutdown, NULL, 998 shutdown_task); 999 if (torture_init_error(firsterr)) 1000 goto unwind; 1001 schedule_timeout_uninterruptible(1); 1002 } 1003 reader_tasks = kcalloc(nrealreaders, sizeof(reader_tasks[0]), 1004 GFP_KERNEL); 1005 if (reader_tasks == NULL) { 1006 SCALEOUT_ERRSTRING("out of memory"); 1007 firsterr = -ENOMEM; 1008 goto unwind; 1009 } 1010 for (i = 0; i < nrealreaders; i++) { 1011 firsterr = torture_create_kthread(rcu_scale_reader, (void *)i, 1012 reader_tasks[i]); 1013 if (torture_init_error(firsterr)) 1014 goto unwind; 1015 } 1016 while (atomic_read(&n_rcu_scale_reader_started) < nrealreaders) 1017 schedule_timeout_uninterruptible(1); 1018 writer_tasks = kcalloc(nrealwriters, sizeof(reader_tasks[0]), 1019 GFP_KERNEL); 1020 writer_durations = kcalloc(nrealwriters, sizeof(*writer_durations), 1021 GFP_KERNEL); 1022 writer_n_durations = 1023 kcalloc(nrealwriters, sizeof(*writer_n_durations), 1024 GFP_KERNEL); 1025 if (!writer_tasks || !writer_durations || !writer_n_durations) { 1026 SCALEOUT_ERRSTRING("out of memory"); 1027 firsterr = -ENOMEM; 1028 goto unwind; 1029 } 1030 for (i = 0; i < nrealwriters; i++) { 1031 writer_durations[i] = 1032 kcalloc(MAX_MEAS, sizeof(*writer_durations[i]), 1033 GFP_KERNEL); 1034 if (!writer_durations[i]) { 1035 firsterr = -ENOMEM; 1036 goto unwind; 1037 } 1038 firsterr = torture_create_kthread(rcu_scale_writer, (void *)i, 1039 writer_tasks[i]); 1040 if (torture_init_error(firsterr)) 1041 goto unwind; 1042 } 1043 torture_init_end(); 1044 return 0; 1045 1046 unwind: 1047 torture_init_end(); 1048 rcu_scale_cleanup(); 1049 if (shutdown) { 1050 WARN_ON(!IS_MODULE(CONFIG_RCU_SCALE_TEST)); 1051 kernel_power_off(); 1052 } 1053 return firsterr; 1054 } 1055 1056 module_init(rcu_scale_init); 1057 module_exit(rcu_scale_cleanup); 1058