1 /* 2 * trace task wakeup timings 3 * 4 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> 5 * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com> 6 * 7 * Based on code from the latency_tracer, that is: 8 * 9 * Copyright (C) 2004-2006 Ingo Molnar 10 * Copyright (C) 2004 Nadia Yvette Chambers 11 */ 12 #include <linux/module.h> 13 #include <linux/kallsyms.h> 14 #include <linux/uaccess.h> 15 #include <linux/ftrace.h> 16 #include <linux/sched/rt.h> 17 #include <linux/sched/deadline.h> 18 #include <trace/events/sched.h> 19 #include "trace.h" 20 21 static struct trace_array *wakeup_trace; 22 static int __read_mostly tracer_enabled; 23 24 static struct task_struct *wakeup_task; 25 static int wakeup_cpu; 26 static int wakeup_current_cpu; 27 static unsigned wakeup_prio = -1; 28 static int wakeup_rt; 29 static int wakeup_dl; 30 static int tracing_dl = 0; 31 32 static arch_spinlock_t wakeup_lock = 33 (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; 34 35 static void wakeup_reset(struct trace_array *tr); 36 static void __wakeup_reset(struct trace_array *tr); 37 38 static int save_flags; 39 40 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 41 static int wakeup_display_graph(struct trace_array *tr, int set); 42 # define is_graph(tr) ((tr)->trace_flags & TRACE_ITER_DISPLAY_GRAPH) 43 #else 44 static inline int wakeup_display_graph(struct trace_array *tr, int set) 45 { 46 return 0; 47 } 48 # define is_graph(tr) false 49 #endif 50 51 52 #ifdef CONFIG_FUNCTION_TRACER 53 54 static int wakeup_graph_entry(struct ftrace_graph_ent *trace); 55 static void wakeup_graph_return(struct ftrace_graph_ret *trace); 56 57 static bool function_enabled; 58 59 /* 60 * Prologue for the wakeup function tracers. 61 * 62 * Returns 1 if it is OK to continue, and preemption 63 * is disabled and data->disabled is incremented. 64 * 0 if the trace is to be ignored, and preemption 65 * is not disabled and data->disabled is 66 * kept the same. 67 * 68 * Note, this function is also used outside this ifdef but 69 * inside the #ifdef of the function graph tracer below. 70 * This is OK, since the function graph tracer is 71 * dependent on the function tracer. 72 */ 73 static int 74 func_prolog_preempt_disable(struct trace_array *tr, 75 struct trace_array_cpu **data, 76 int *pc) 77 { 78 long disabled; 79 int cpu; 80 81 if (likely(!wakeup_task)) 82 return 0; 83 84 *pc = preempt_count(); 85 preempt_disable_notrace(); 86 87 cpu = raw_smp_processor_id(); 88 if (cpu != wakeup_current_cpu) 89 goto out_enable; 90 91 *data = per_cpu_ptr(tr->trace_buffer.data, cpu); 92 disabled = atomic_inc_return(&(*data)->disabled); 93 if (unlikely(disabled != 1)) 94 goto out; 95 96 return 1; 97 98 out: 99 atomic_dec(&(*data)->disabled); 100 101 out_enable: 102 preempt_enable_notrace(); 103 return 0; 104 } 105 106 /* 107 * wakeup uses its own tracer function to keep the overhead down: 108 */ 109 static void 110 wakeup_tracer_call(unsigned long ip, unsigned long parent_ip, 111 struct ftrace_ops *op, struct pt_regs *pt_regs) 112 { 113 struct trace_array *tr = wakeup_trace; 114 struct trace_array_cpu *data; 115 unsigned long flags; 116 int pc; 117 118 if (!func_prolog_preempt_disable(tr, &data, &pc)) 119 return; 120 121 local_irq_save(flags); 122 trace_function(tr, ip, parent_ip, flags, pc); 123 local_irq_restore(flags); 124 125 atomic_dec(&data->disabled); 126 preempt_enable_notrace(); 127 } 128 129 static int register_wakeup_function(struct trace_array *tr, int graph, int set) 130 { 131 int ret; 132 133 /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */ 134 if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION))) 135 return 0; 136 137 if (graph) 138 ret = register_ftrace_graph(&wakeup_graph_return, 139 &wakeup_graph_entry); 140 else 141 ret = register_ftrace_function(tr->ops); 142 143 if (!ret) 144 function_enabled = true; 145 146 return ret; 147 } 148 149 static void unregister_wakeup_function(struct trace_array *tr, int graph) 150 { 151 if (!function_enabled) 152 return; 153 154 if (graph) 155 unregister_ftrace_graph(); 156 else 157 unregister_ftrace_function(tr->ops); 158 159 function_enabled = false; 160 } 161 162 static int wakeup_function_set(struct trace_array *tr, u32 mask, int set) 163 { 164 if (!(mask & TRACE_ITER_FUNCTION)) 165 return 0; 166 167 if (set) 168 register_wakeup_function(tr, is_graph(tr), 1); 169 else 170 unregister_wakeup_function(tr, is_graph(tr)); 171 return 1; 172 } 173 #else 174 static int register_wakeup_function(struct trace_array *tr, int graph, int set) 175 { 176 return 0; 177 } 178 static void unregister_wakeup_function(struct trace_array *tr, int graph) { } 179 static int wakeup_function_set(struct trace_array *tr, u32 mask, int set) 180 { 181 return 0; 182 } 183 #endif /* CONFIG_FUNCTION_TRACER */ 184 185 static int wakeup_flag_changed(struct trace_array *tr, u32 mask, int set) 186 { 187 struct tracer *tracer = tr->current_trace; 188 189 if (wakeup_function_set(tr, mask, set)) 190 return 0; 191 192 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 193 if (mask & TRACE_ITER_DISPLAY_GRAPH) 194 return wakeup_display_graph(tr, set); 195 #endif 196 197 return trace_keep_overwrite(tracer, mask, set); 198 } 199 200 static int start_func_tracer(struct trace_array *tr, int graph) 201 { 202 int ret; 203 204 ret = register_wakeup_function(tr, graph, 0); 205 206 if (!ret && tracing_is_enabled()) 207 tracer_enabled = 1; 208 else 209 tracer_enabled = 0; 210 211 return ret; 212 } 213 214 static void stop_func_tracer(struct trace_array *tr, int graph) 215 { 216 tracer_enabled = 0; 217 218 unregister_wakeup_function(tr, graph); 219 } 220 221 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 222 static int wakeup_display_graph(struct trace_array *tr, int set) 223 { 224 if (!(is_graph(tr) ^ set)) 225 return 0; 226 227 stop_func_tracer(tr, !set); 228 229 wakeup_reset(wakeup_trace); 230 tr->max_latency = 0; 231 232 return start_func_tracer(tr, set); 233 } 234 235 static int wakeup_graph_entry(struct ftrace_graph_ent *trace) 236 { 237 struct trace_array *tr = wakeup_trace; 238 struct trace_array_cpu *data; 239 unsigned long flags; 240 int pc, ret = 0; 241 242 if (!func_prolog_preempt_disable(tr, &data, &pc)) 243 return 0; 244 245 local_save_flags(flags); 246 ret = __trace_graph_entry(tr, trace, flags, pc); 247 atomic_dec(&data->disabled); 248 preempt_enable_notrace(); 249 250 return ret; 251 } 252 253 static void wakeup_graph_return(struct ftrace_graph_ret *trace) 254 { 255 struct trace_array *tr = wakeup_trace; 256 struct trace_array_cpu *data; 257 unsigned long flags; 258 int pc; 259 260 if (!func_prolog_preempt_disable(tr, &data, &pc)) 261 return; 262 263 local_save_flags(flags); 264 __trace_graph_return(tr, trace, flags, pc); 265 atomic_dec(&data->disabled); 266 267 preempt_enable_notrace(); 268 return; 269 } 270 271 static void wakeup_trace_open(struct trace_iterator *iter) 272 { 273 if (is_graph(iter->tr)) 274 graph_trace_open(iter); 275 } 276 277 static void wakeup_trace_close(struct trace_iterator *iter) 278 { 279 if (iter->private) 280 graph_trace_close(iter); 281 } 282 283 #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_PROC | \ 284 TRACE_GRAPH_PRINT_ABS_TIME | \ 285 TRACE_GRAPH_PRINT_DURATION) 286 287 static enum print_line_t wakeup_print_line(struct trace_iterator *iter) 288 { 289 /* 290 * In graph mode call the graph tracer output function, 291 * otherwise go with the TRACE_FN event handler 292 */ 293 if (is_graph(iter->tr)) 294 return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS); 295 296 return TRACE_TYPE_UNHANDLED; 297 } 298 299 static void wakeup_print_header(struct seq_file *s) 300 { 301 if (is_graph(wakeup_trace)) 302 print_graph_headers_flags(s, GRAPH_TRACER_FLAGS); 303 else 304 trace_default_header(s); 305 } 306 307 static void 308 __trace_function(struct trace_array *tr, 309 unsigned long ip, unsigned long parent_ip, 310 unsigned long flags, int pc) 311 { 312 if (is_graph(tr)) 313 trace_graph_function(tr, ip, parent_ip, flags, pc); 314 else 315 trace_function(tr, ip, parent_ip, flags, pc); 316 } 317 #else 318 #define __trace_function trace_function 319 320 static enum print_line_t wakeup_print_line(struct trace_iterator *iter) 321 { 322 return TRACE_TYPE_UNHANDLED; 323 } 324 325 static void wakeup_trace_open(struct trace_iterator *iter) { } 326 static void wakeup_trace_close(struct trace_iterator *iter) { } 327 328 #ifdef CONFIG_FUNCTION_TRACER 329 static int wakeup_graph_entry(struct ftrace_graph_ent *trace) 330 { 331 return -1; 332 } 333 static void wakeup_graph_return(struct ftrace_graph_ret *trace) { } 334 static void wakeup_print_header(struct seq_file *s) 335 { 336 trace_default_header(s); 337 } 338 #else 339 static void wakeup_print_header(struct seq_file *s) 340 { 341 trace_latency_header(s); 342 } 343 #endif /* CONFIG_FUNCTION_TRACER */ 344 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 345 346 /* 347 * Should this new latency be reported/recorded? 348 */ 349 static bool report_latency(struct trace_array *tr, cycle_t delta) 350 { 351 if (tracing_thresh) { 352 if (delta < tracing_thresh) 353 return false; 354 } else { 355 if (delta <= tr->max_latency) 356 return false; 357 } 358 return true; 359 } 360 361 static void 362 probe_wakeup_migrate_task(void *ignore, struct task_struct *task, int cpu) 363 { 364 if (task != wakeup_task) 365 return; 366 367 wakeup_current_cpu = cpu; 368 } 369 370 static void 371 tracing_sched_switch_trace(struct trace_array *tr, 372 struct task_struct *prev, 373 struct task_struct *next, 374 unsigned long flags, int pc) 375 { 376 struct trace_event_call *call = &event_context_switch; 377 struct ring_buffer *buffer = tr->trace_buffer.buffer; 378 struct ring_buffer_event *event; 379 struct ctx_switch_entry *entry; 380 381 event = trace_buffer_lock_reserve(buffer, TRACE_CTX, 382 sizeof(*entry), flags, pc); 383 if (!event) 384 return; 385 entry = ring_buffer_event_data(event); 386 entry->prev_pid = prev->pid; 387 entry->prev_prio = prev->prio; 388 entry->prev_state = prev->state; 389 entry->next_pid = next->pid; 390 entry->next_prio = next->prio; 391 entry->next_state = next->state; 392 entry->next_cpu = task_cpu(next); 393 394 if (!call_filter_check_discard(call, entry, buffer, event)) 395 trace_buffer_unlock_commit(tr, buffer, event, flags, pc); 396 } 397 398 static void 399 tracing_sched_wakeup_trace(struct trace_array *tr, 400 struct task_struct *wakee, 401 struct task_struct *curr, 402 unsigned long flags, int pc) 403 { 404 struct trace_event_call *call = &event_wakeup; 405 struct ring_buffer_event *event; 406 struct ctx_switch_entry *entry; 407 struct ring_buffer *buffer = tr->trace_buffer.buffer; 408 409 event = trace_buffer_lock_reserve(buffer, TRACE_WAKE, 410 sizeof(*entry), flags, pc); 411 if (!event) 412 return; 413 entry = ring_buffer_event_data(event); 414 entry->prev_pid = curr->pid; 415 entry->prev_prio = curr->prio; 416 entry->prev_state = curr->state; 417 entry->next_pid = wakee->pid; 418 entry->next_prio = wakee->prio; 419 entry->next_state = wakee->state; 420 entry->next_cpu = task_cpu(wakee); 421 422 if (!call_filter_check_discard(call, entry, buffer, event)) 423 trace_buffer_unlock_commit(tr, buffer, event, flags, pc); 424 } 425 426 static void notrace 427 probe_wakeup_sched_switch(void *ignore, bool preempt, 428 struct task_struct *prev, struct task_struct *next) 429 { 430 struct trace_array_cpu *data; 431 cycle_t T0, T1, delta; 432 unsigned long flags; 433 long disabled; 434 int cpu; 435 int pc; 436 437 tracing_record_cmdline(prev); 438 439 if (unlikely(!tracer_enabled)) 440 return; 441 442 /* 443 * When we start a new trace, we set wakeup_task to NULL 444 * and then set tracer_enabled = 1. We want to make sure 445 * that another CPU does not see the tracer_enabled = 1 446 * and the wakeup_task with an older task, that might 447 * actually be the same as next. 448 */ 449 smp_rmb(); 450 451 if (next != wakeup_task) 452 return; 453 454 pc = preempt_count(); 455 456 /* disable local data, not wakeup_cpu data */ 457 cpu = raw_smp_processor_id(); 458 disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); 459 if (likely(disabled != 1)) 460 goto out; 461 462 local_irq_save(flags); 463 arch_spin_lock(&wakeup_lock); 464 465 /* We could race with grabbing wakeup_lock */ 466 if (unlikely(!tracer_enabled || next != wakeup_task)) 467 goto out_unlock; 468 469 /* The task we are waiting for is waking up */ 470 data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu); 471 472 __trace_function(wakeup_trace, CALLER_ADDR0, CALLER_ADDR1, flags, pc); 473 tracing_sched_switch_trace(wakeup_trace, prev, next, flags, pc); 474 475 T0 = data->preempt_timestamp; 476 T1 = ftrace_now(cpu); 477 delta = T1-T0; 478 479 if (!report_latency(wakeup_trace, delta)) 480 goto out_unlock; 481 482 if (likely(!is_tracing_stopped())) { 483 wakeup_trace->max_latency = delta; 484 update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu); 485 } 486 487 out_unlock: 488 __wakeup_reset(wakeup_trace); 489 arch_spin_unlock(&wakeup_lock); 490 local_irq_restore(flags); 491 out: 492 atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); 493 } 494 495 static void __wakeup_reset(struct trace_array *tr) 496 { 497 wakeup_cpu = -1; 498 wakeup_prio = -1; 499 tracing_dl = 0; 500 501 if (wakeup_task) 502 put_task_struct(wakeup_task); 503 504 wakeup_task = NULL; 505 } 506 507 static void wakeup_reset(struct trace_array *tr) 508 { 509 unsigned long flags; 510 511 tracing_reset_online_cpus(&tr->trace_buffer); 512 513 local_irq_save(flags); 514 arch_spin_lock(&wakeup_lock); 515 __wakeup_reset(tr); 516 arch_spin_unlock(&wakeup_lock); 517 local_irq_restore(flags); 518 } 519 520 static void 521 probe_wakeup(void *ignore, struct task_struct *p) 522 { 523 struct trace_array_cpu *data; 524 int cpu = smp_processor_id(); 525 unsigned long flags; 526 long disabled; 527 int pc; 528 529 if (likely(!tracer_enabled)) 530 return; 531 532 tracing_record_cmdline(p); 533 tracing_record_cmdline(current); 534 535 /* 536 * Semantic is like this: 537 * - wakeup tracer handles all tasks in the system, independently 538 * from their scheduling class; 539 * - wakeup_rt tracer handles tasks belonging to sched_dl and 540 * sched_rt class; 541 * - wakeup_dl handles tasks belonging to sched_dl class only. 542 */ 543 if (tracing_dl || (wakeup_dl && !dl_task(p)) || 544 (wakeup_rt && !dl_task(p) && !rt_task(p)) || 545 (!dl_task(p) && (p->prio >= wakeup_prio || p->prio >= current->prio))) 546 return; 547 548 pc = preempt_count(); 549 disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); 550 if (unlikely(disabled != 1)) 551 goto out; 552 553 /* interrupts should be off from try_to_wake_up */ 554 arch_spin_lock(&wakeup_lock); 555 556 /* check for races. */ 557 if (!tracer_enabled || tracing_dl || 558 (!dl_task(p) && p->prio >= wakeup_prio)) 559 goto out_locked; 560 561 /* reset the trace */ 562 __wakeup_reset(wakeup_trace); 563 564 wakeup_cpu = task_cpu(p); 565 wakeup_current_cpu = wakeup_cpu; 566 wakeup_prio = p->prio; 567 568 /* 569 * Once you start tracing a -deadline task, don't bother tracing 570 * another task until the first one wakes up. 571 */ 572 if (dl_task(p)) 573 tracing_dl = 1; 574 else 575 tracing_dl = 0; 576 577 wakeup_task = p; 578 get_task_struct(wakeup_task); 579 580 local_save_flags(flags); 581 582 data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu); 583 data->preempt_timestamp = ftrace_now(cpu); 584 tracing_sched_wakeup_trace(wakeup_trace, p, current, flags, pc); 585 586 /* 587 * We must be careful in using CALLER_ADDR2. But since wake_up 588 * is not called by an assembly function (where as schedule is) 589 * it should be safe to use it here. 590 */ 591 __trace_function(wakeup_trace, CALLER_ADDR1, CALLER_ADDR2, flags, pc); 592 593 out_locked: 594 arch_spin_unlock(&wakeup_lock); 595 out: 596 atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); 597 } 598 599 static void start_wakeup_tracer(struct trace_array *tr) 600 { 601 int ret; 602 603 ret = register_trace_sched_wakeup(probe_wakeup, NULL); 604 if (ret) { 605 pr_info("wakeup trace: Couldn't activate tracepoint" 606 " probe to kernel_sched_wakeup\n"); 607 return; 608 } 609 610 ret = register_trace_sched_wakeup_new(probe_wakeup, NULL); 611 if (ret) { 612 pr_info("wakeup trace: Couldn't activate tracepoint" 613 " probe to kernel_sched_wakeup_new\n"); 614 goto fail_deprobe; 615 } 616 617 ret = register_trace_sched_switch(probe_wakeup_sched_switch, NULL); 618 if (ret) { 619 pr_info("sched trace: Couldn't activate tracepoint" 620 " probe to kernel_sched_switch\n"); 621 goto fail_deprobe_wake_new; 622 } 623 624 ret = register_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL); 625 if (ret) { 626 pr_info("wakeup trace: Couldn't activate tracepoint" 627 " probe to kernel_sched_migrate_task\n"); 628 return; 629 } 630 631 wakeup_reset(tr); 632 633 /* 634 * Don't let the tracer_enabled = 1 show up before 635 * the wakeup_task is reset. This may be overkill since 636 * wakeup_reset does a spin_unlock after setting the 637 * wakeup_task to NULL, but I want to be safe. 638 * This is a slow path anyway. 639 */ 640 smp_wmb(); 641 642 if (start_func_tracer(tr, is_graph(tr))) 643 printk(KERN_ERR "failed to start wakeup tracer\n"); 644 645 return; 646 fail_deprobe_wake_new: 647 unregister_trace_sched_wakeup_new(probe_wakeup, NULL); 648 fail_deprobe: 649 unregister_trace_sched_wakeup(probe_wakeup, NULL); 650 } 651 652 static void stop_wakeup_tracer(struct trace_array *tr) 653 { 654 tracer_enabled = 0; 655 stop_func_tracer(tr, is_graph(tr)); 656 unregister_trace_sched_switch(probe_wakeup_sched_switch, NULL); 657 unregister_trace_sched_wakeup_new(probe_wakeup, NULL); 658 unregister_trace_sched_wakeup(probe_wakeup, NULL); 659 unregister_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL); 660 } 661 662 static bool wakeup_busy; 663 664 static int __wakeup_tracer_init(struct trace_array *tr) 665 { 666 save_flags = tr->trace_flags; 667 668 /* non overwrite screws up the latency tracers */ 669 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1); 670 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1); 671 672 tr->max_latency = 0; 673 wakeup_trace = tr; 674 ftrace_init_array_ops(tr, wakeup_tracer_call); 675 start_wakeup_tracer(tr); 676 677 wakeup_busy = true; 678 return 0; 679 } 680 681 static int wakeup_tracer_init(struct trace_array *tr) 682 { 683 if (wakeup_busy) 684 return -EBUSY; 685 686 wakeup_dl = 0; 687 wakeup_rt = 0; 688 return __wakeup_tracer_init(tr); 689 } 690 691 static int wakeup_rt_tracer_init(struct trace_array *tr) 692 { 693 if (wakeup_busy) 694 return -EBUSY; 695 696 wakeup_dl = 0; 697 wakeup_rt = 1; 698 return __wakeup_tracer_init(tr); 699 } 700 701 static int wakeup_dl_tracer_init(struct trace_array *tr) 702 { 703 if (wakeup_busy) 704 return -EBUSY; 705 706 wakeup_dl = 1; 707 wakeup_rt = 0; 708 return __wakeup_tracer_init(tr); 709 } 710 711 static void wakeup_tracer_reset(struct trace_array *tr) 712 { 713 int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT; 714 int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE; 715 716 stop_wakeup_tracer(tr); 717 /* make sure we put back any tasks we are tracing */ 718 wakeup_reset(tr); 719 720 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag); 721 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag); 722 ftrace_reset_array_ops(tr); 723 wakeup_busy = false; 724 } 725 726 static void wakeup_tracer_start(struct trace_array *tr) 727 { 728 wakeup_reset(tr); 729 tracer_enabled = 1; 730 } 731 732 static void wakeup_tracer_stop(struct trace_array *tr) 733 { 734 tracer_enabled = 0; 735 } 736 737 static struct tracer wakeup_tracer __read_mostly = 738 { 739 .name = "wakeup", 740 .init = wakeup_tracer_init, 741 .reset = wakeup_tracer_reset, 742 .start = wakeup_tracer_start, 743 .stop = wakeup_tracer_stop, 744 .print_max = true, 745 .print_header = wakeup_print_header, 746 .print_line = wakeup_print_line, 747 .flag_changed = wakeup_flag_changed, 748 #ifdef CONFIG_FTRACE_SELFTEST 749 .selftest = trace_selftest_startup_wakeup, 750 #endif 751 .open = wakeup_trace_open, 752 .close = wakeup_trace_close, 753 .allow_instances = true, 754 .use_max_tr = true, 755 }; 756 757 static struct tracer wakeup_rt_tracer __read_mostly = 758 { 759 .name = "wakeup_rt", 760 .init = wakeup_rt_tracer_init, 761 .reset = wakeup_tracer_reset, 762 .start = wakeup_tracer_start, 763 .stop = wakeup_tracer_stop, 764 .print_max = true, 765 .print_header = wakeup_print_header, 766 .print_line = wakeup_print_line, 767 .flag_changed = wakeup_flag_changed, 768 #ifdef CONFIG_FTRACE_SELFTEST 769 .selftest = trace_selftest_startup_wakeup, 770 #endif 771 .open = wakeup_trace_open, 772 .close = wakeup_trace_close, 773 .allow_instances = true, 774 .use_max_tr = true, 775 }; 776 777 static struct tracer wakeup_dl_tracer __read_mostly = 778 { 779 .name = "wakeup_dl", 780 .init = wakeup_dl_tracer_init, 781 .reset = wakeup_tracer_reset, 782 .start = wakeup_tracer_start, 783 .stop = wakeup_tracer_stop, 784 .print_max = true, 785 .print_header = wakeup_print_header, 786 .print_line = wakeup_print_line, 787 .flag_changed = wakeup_flag_changed, 788 #ifdef CONFIG_FTRACE_SELFTEST 789 .selftest = trace_selftest_startup_wakeup, 790 #endif 791 .open = wakeup_trace_open, 792 .close = wakeup_trace_close, 793 .use_max_tr = true, 794 }; 795 796 __init static int init_wakeup_tracer(void) 797 { 798 int ret; 799 800 ret = register_tracer(&wakeup_tracer); 801 if (ret) 802 return ret; 803 804 ret = register_tracer(&wakeup_rt_tracer); 805 if (ret) 806 return ret; 807 808 ret = register_tracer(&wakeup_dl_tracer); 809 if (ret) 810 return ret; 811 812 return 0; 813 } 814 core_initcall(init_wakeup_tracer); 815