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/fs.h> 14 #include <linux/debugfs.h> 15 #include <linux/kallsyms.h> 16 #include <linux/uaccess.h> 17 #include <linux/ftrace.h> 18 #include <linux/sched/rt.h> 19 #include <linux/sched/deadline.h> 20 #include <trace/events/sched.h> 21 #include "trace.h" 22 23 static struct trace_array *wakeup_trace; 24 static int __read_mostly tracer_enabled; 25 26 static struct task_struct *wakeup_task; 27 static int wakeup_cpu; 28 static int wakeup_current_cpu; 29 static unsigned wakeup_prio = -1; 30 static int wakeup_rt; 31 static int wakeup_dl; 32 static int tracing_dl = 0; 33 34 static arch_spinlock_t wakeup_lock = 35 (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; 36 37 static void wakeup_reset(struct trace_array *tr); 38 static void __wakeup_reset(struct trace_array *tr); 39 static int wakeup_graph_entry(struct ftrace_graph_ent *trace); 40 static void wakeup_graph_return(struct ftrace_graph_ret *trace); 41 42 static int save_flags; 43 static bool function_enabled; 44 45 #define TRACE_DISPLAY_GRAPH 1 46 47 static struct tracer_opt trace_opts[] = { 48 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 49 /* display latency trace as call graph */ 50 { TRACER_OPT(display-graph, TRACE_DISPLAY_GRAPH) }, 51 #endif 52 { } /* Empty entry */ 53 }; 54 55 static struct tracer_flags tracer_flags = { 56 .val = 0, 57 .opts = trace_opts, 58 }; 59 60 #define is_graph() (tracer_flags.val & TRACE_DISPLAY_GRAPH) 61 62 #ifdef CONFIG_FUNCTION_TRACER 63 64 /* 65 * Prologue for the wakeup function tracers. 66 * 67 * Returns 1 if it is OK to continue, and preemption 68 * is disabled and data->disabled is incremented. 69 * 0 if the trace is to be ignored, and preemption 70 * is not disabled and data->disabled is 71 * kept the same. 72 * 73 * Note, this function is also used outside this ifdef but 74 * inside the #ifdef of the function graph tracer below. 75 * This is OK, since the function graph tracer is 76 * dependent on the function tracer. 77 */ 78 static int 79 func_prolog_preempt_disable(struct trace_array *tr, 80 struct trace_array_cpu **data, 81 int *pc) 82 { 83 long disabled; 84 int cpu; 85 86 if (likely(!wakeup_task)) 87 return 0; 88 89 *pc = preempt_count(); 90 preempt_disable_notrace(); 91 92 cpu = raw_smp_processor_id(); 93 if (cpu != wakeup_current_cpu) 94 goto out_enable; 95 96 *data = per_cpu_ptr(tr->trace_buffer.data, cpu); 97 disabled = atomic_inc_return(&(*data)->disabled); 98 if (unlikely(disabled != 1)) 99 goto out; 100 101 return 1; 102 103 out: 104 atomic_dec(&(*data)->disabled); 105 106 out_enable: 107 preempt_enable_notrace(); 108 return 0; 109 } 110 111 /* 112 * wakeup uses its own tracer function to keep the overhead down: 113 */ 114 static void 115 wakeup_tracer_call(unsigned long ip, unsigned long parent_ip, 116 struct ftrace_ops *op, struct pt_regs *pt_regs) 117 { 118 struct trace_array *tr = wakeup_trace; 119 struct trace_array_cpu *data; 120 unsigned long flags; 121 int pc; 122 123 if (!func_prolog_preempt_disable(tr, &data, &pc)) 124 return; 125 126 local_irq_save(flags); 127 trace_function(tr, ip, parent_ip, flags, pc); 128 local_irq_restore(flags); 129 130 atomic_dec(&data->disabled); 131 preempt_enable_notrace(); 132 } 133 #endif /* CONFIG_FUNCTION_TRACER */ 134 135 static int register_wakeup_function(struct trace_array *tr, int graph, int set) 136 { 137 int ret; 138 139 /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */ 140 if (function_enabled || (!set && !(trace_flags & TRACE_ITER_FUNCTION))) 141 return 0; 142 143 if (graph) 144 ret = register_ftrace_graph(&wakeup_graph_return, 145 &wakeup_graph_entry); 146 else 147 ret = register_ftrace_function(tr->ops); 148 149 if (!ret) 150 function_enabled = true; 151 152 return ret; 153 } 154 155 static void unregister_wakeup_function(struct trace_array *tr, int graph) 156 { 157 if (!function_enabled) 158 return; 159 160 if (graph) 161 unregister_ftrace_graph(); 162 else 163 unregister_ftrace_function(tr->ops); 164 165 function_enabled = false; 166 } 167 168 static void wakeup_function_set(struct trace_array *tr, int set) 169 { 170 if (set) 171 register_wakeup_function(tr, is_graph(), 1); 172 else 173 unregister_wakeup_function(tr, is_graph()); 174 } 175 176 static int wakeup_flag_changed(struct trace_array *tr, u32 mask, int set) 177 { 178 struct tracer *tracer = tr->current_trace; 179 180 if (mask & TRACE_ITER_FUNCTION) 181 wakeup_function_set(tr, set); 182 183 return trace_keep_overwrite(tracer, mask, set); 184 } 185 186 static int start_func_tracer(struct trace_array *tr, int graph) 187 { 188 int ret; 189 190 ret = register_wakeup_function(tr, graph, 0); 191 192 if (!ret && tracing_is_enabled()) 193 tracer_enabled = 1; 194 else 195 tracer_enabled = 0; 196 197 return ret; 198 } 199 200 static void stop_func_tracer(struct trace_array *tr, int graph) 201 { 202 tracer_enabled = 0; 203 204 unregister_wakeup_function(tr, graph); 205 } 206 207 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 208 static int 209 wakeup_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set) 210 { 211 212 if (!(bit & TRACE_DISPLAY_GRAPH)) 213 return -EINVAL; 214 215 if (!(is_graph() ^ set)) 216 return 0; 217 218 stop_func_tracer(tr, !set); 219 220 wakeup_reset(wakeup_trace); 221 tr->max_latency = 0; 222 223 return start_func_tracer(tr, set); 224 } 225 226 static int wakeup_graph_entry(struct ftrace_graph_ent *trace) 227 { 228 struct trace_array *tr = wakeup_trace; 229 struct trace_array_cpu *data; 230 unsigned long flags; 231 int pc, ret = 0; 232 233 if (!func_prolog_preempt_disable(tr, &data, &pc)) 234 return 0; 235 236 local_save_flags(flags); 237 ret = __trace_graph_entry(tr, trace, flags, pc); 238 atomic_dec(&data->disabled); 239 preempt_enable_notrace(); 240 241 return ret; 242 } 243 244 static void wakeup_graph_return(struct ftrace_graph_ret *trace) 245 { 246 struct trace_array *tr = wakeup_trace; 247 struct trace_array_cpu *data; 248 unsigned long flags; 249 int pc; 250 251 if (!func_prolog_preempt_disable(tr, &data, &pc)) 252 return; 253 254 local_save_flags(flags); 255 __trace_graph_return(tr, trace, flags, pc); 256 atomic_dec(&data->disabled); 257 258 preempt_enable_notrace(); 259 return; 260 } 261 262 static void wakeup_trace_open(struct trace_iterator *iter) 263 { 264 if (is_graph()) 265 graph_trace_open(iter); 266 } 267 268 static void wakeup_trace_close(struct trace_iterator *iter) 269 { 270 if (iter->private) 271 graph_trace_close(iter); 272 } 273 274 #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_PROC | \ 275 TRACE_GRAPH_PRINT_ABS_TIME | \ 276 TRACE_GRAPH_PRINT_DURATION) 277 278 static enum print_line_t wakeup_print_line(struct trace_iterator *iter) 279 { 280 /* 281 * In graph mode call the graph tracer output function, 282 * otherwise go with the TRACE_FN event handler 283 */ 284 if (is_graph()) 285 return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS); 286 287 return TRACE_TYPE_UNHANDLED; 288 } 289 290 static void wakeup_print_header(struct seq_file *s) 291 { 292 if (is_graph()) 293 print_graph_headers_flags(s, GRAPH_TRACER_FLAGS); 294 else 295 trace_default_header(s); 296 } 297 298 static void 299 __trace_function(struct trace_array *tr, 300 unsigned long ip, unsigned long parent_ip, 301 unsigned long flags, int pc) 302 { 303 if (is_graph()) 304 trace_graph_function(tr, ip, parent_ip, flags, pc); 305 else 306 trace_function(tr, ip, parent_ip, flags, pc); 307 } 308 #else 309 #define __trace_function trace_function 310 311 static int 312 wakeup_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set) 313 { 314 return -EINVAL; 315 } 316 317 static int wakeup_graph_entry(struct ftrace_graph_ent *trace) 318 { 319 return -1; 320 } 321 322 static enum print_line_t wakeup_print_line(struct trace_iterator *iter) 323 { 324 return TRACE_TYPE_UNHANDLED; 325 } 326 327 static void wakeup_graph_return(struct ftrace_graph_ret *trace) { } 328 static void wakeup_trace_open(struct trace_iterator *iter) { } 329 static void wakeup_trace_close(struct trace_iterator *iter) { } 330 331 #ifdef CONFIG_FUNCTION_TRACER 332 static void wakeup_print_header(struct seq_file *s) 333 { 334 trace_default_header(s); 335 } 336 #else 337 static void wakeup_print_header(struct seq_file *s) 338 { 339 trace_latency_header(s); 340 } 341 #endif /* CONFIG_FUNCTION_TRACER */ 342 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 343 344 /* 345 * Should this new latency be reported/recorded? 346 */ 347 static int report_latency(struct trace_array *tr, cycle_t delta) 348 { 349 if (tracing_thresh) { 350 if (delta < tracing_thresh) 351 return 0; 352 } else { 353 if (delta <= tr->max_latency) 354 return 0; 355 } 356 return 1; 357 } 358 359 static void 360 probe_wakeup_migrate_task(void *ignore, struct task_struct *task, int cpu) 361 { 362 if (task != wakeup_task) 363 return; 364 365 wakeup_current_cpu = cpu; 366 } 367 368 static void 369 tracing_sched_switch_trace(struct trace_array *tr, 370 struct task_struct *prev, 371 struct task_struct *next, 372 unsigned long flags, int pc) 373 { 374 struct ftrace_event_call *call = &event_context_switch; 375 struct ring_buffer *buffer = tr->trace_buffer.buffer; 376 struct ring_buffer_event *event; 377 struct ctx_switch_entry *entry; 378 379 event = trace_buffer_lock_reserve(buffer, TRACE_CTX, 380 sizeof(*entry), flags, pc); 381 if (!event) 382 return; 383 entry = ring_buffer_event_data(event); 384 entry->prev_pid = prev->pid; 385 entry->prev_prio = prev->prio; 386 entry->prev_state = prev->state; 387 entry->next_pid = next->pid; 388 entry->next_prio = next->prio; 389 entry->next_state = next->state; 390 entry->next_cpu = task_cpu(next); 391 392 if (!call_filter_check_discard(call, entry, buffer, event)) 393 trace_buffer_unlock_commit(buffer, event, flags, pc); 394 } 395 396 static void 397 tracing_sched_wakeup_trace(struct trace_array *tr, 398 struct task_struct *wakee, 399 struct task_struct *curr, 400 unsigned long flags, int pc) 401 { 402 struct ftrace_event_call *call = &event_wakeup; 403 struct ring_buffer_event *event; 404 struct ctx_switch_entry *entry; 405 struct ring_buffer *buffer = tr->trace_buffer.buffer; 406 407 event = trace_buffer_lock_reserve(buffer, TRACE_WAKE, 408 sizeof(*entry), flags, pc); 409 if (!event) 410 return; 411 entry = ring_buffer_event_data(event); 412 entry->prev_pid = curr->pid; 413 entry->prev_prio = curr->prio; 414 entry->prev_state = curr->state; 415 entry->next_pid = wakee->pid; 416 entry->next_prio = wakee->prio; 417 entry->next_state = wakee->state; 418 entry->next_cpu = task_cpu(wakee); 419 420 if (!call_filter_check_discard(call, entry, buffer, event)) 421 trace_buffer_unlock_commit(buffer, event, flags, pc); 422 } 423 424 static void notrace 425 probe_wakeup_sched_switch(void *ignore, 426 struct task_struct *prev, struct task_struct *next) 427 { 428 struct trace_array_cpu *data; 429 cycle_t T0, T1, delta; 430 unsigned long flags; 431 long disabled; 432 int cpu; 433 int pc; 434 435 tracing_record_cmdline(prev); 436 437 if (unlikely(!tracer_enabled)) 438 return; 439 440 /* 441 * When we start a new trace, we set wakeup_task to NULL 442 * and then set tracer_enabled = 1. We want to make sure 443 * that another CPU does not see the tracer_enabled = 1 444 * and the wakeup_task with an older task, that might 445 * actually be the same as next. 446 */ 447 smp_rmb(); 448 449 if (next != wakeup_task) 450 return; 451 452 pc = preempt_count(); 453 454 /* disable local data, not wakeup_cpu data */ 455 cpu = raw_smp_processor_id(); 456 disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); 457 if (likely(disabled != 1)) 458 goto out; 459 460 local_irq_save(flags); 461 arch_spin_lock(&wakeup_lock); 462 463 /* We could race with grabbing wakeup_lock */ 464 if (unlikely(!tracer_enabled || next != wakeup_task)) 465 goto out_unlock; 466 467 /* The task we are waiting for is waking up */ 468 data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu); 469 470 __trace_function(wakeup_trace, CALLER_ADDR0, CALLER_ADDR1, flags, pc); 471 tracing_sched_switch_trace(wakeup_trace, prev, next, flags, pc); 472 473 T0 = data->preempt_timestamp; 474 T1 = ftrace_now(cpu); 475 delta = T1-T0; 476 477 if (!report_latency(wakeup_trace, delta)) 478 goto out_unlock; 479 480 if (likely(!is_tracing_stopped())) { 481 wakeup_trace->max_latency = delta; 482 update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu); 483 } 484 485 out_unlock: 486 __wakeup_reset(wakeup_trace); 487 arch_spin_unlock(&wakeup_lock); 488 local_irq_restore(flags); 489 out: 490 atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); 491 } 492 493 static void __wakeup_reset(struct trace_array *tr) 494 { 495 wakeup_cpu = -1; 496 wakeup_prio = -1; 497 tracing_dl = 0; 498 499 if (wakeup_task) 500 put_task_struct(wakeup_task); 501 502 wakeup_task = NULL; 503 } 504 505 static void wakeup_reset(struct trace_array *tr) 506 { 507 unsigned long flags; 508 509 tracing_reset_online_cpus(&tr->trace_buffer); 510 511 local_irq_save(flags); 512 arch_spin_lock(&wakeup_lock); 513 __wakeup_reset(tr); 514 arch_spin_unlock(&wakeup_lock); 515 local_irq_restore(flags); 516 } 517 518 static void 519 probe_wakeup(void *ignore, struct task_struct *p, int success) 520 { 521 struct trace_array_cpu *data; 522 int cpu = smp_processor_id(); 523 unsigned long flags; 524 long disabled; 525 int pc; 526 527 if (likely(!tracer_enabled)) 528 return; 529 530 tracing_record_cmdline(p); 531 tracing_record_cmdline(current); 532 533 /* 534 * Semantic is like this: 535 * - wakeup tracer handles all tasks in the system, independently 536 * from their scheduling class; 537 * - wakeup_rt tracer handles tasks belonging to sched_dl and 538 * sched_rt class; 539 * - wakeup_dl handles tasks belonging to sched_dl class only. 540 */ 541 if (tracing_dl || (wakeup_dl && !dl_task(p)) || 542 (wakeup_rt && !dl_task(p) && !rt_task(p)) || 543 (!dl_task(p) && (p->prio >= wakeup_prio || p->prio >= current->prio))) 544 return; 545 546 pc = preempt_count(); 547 disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); 548 if (unlikely(disabled != 1)) 549 goto out; 550 551 /* interrupts should be off from try_to_wake_up */ 552 arch_spin_lock(&wakeup_lock); 553 554 /* check for races. */ 555 if (!tracer_enabled || tracing_dl || 556 (!dl_task(p) && p->prio >= wakeup_prio)) 557 goto out_locked; 558 559 /* reset the trace */ 560 __wakeup_reset(wakeup_trace); 561 562 wakeup_cpu = task_cpu(p); 563 wakeup_current_cpu = wakeup_cpu; 564 wakeup_prio = p->prio; 565 566 /* 567 * Once you start tracing a -deadline task, don't bother tracing 568 * another task until the first one wakes up. 569 */ 570 if (dl_task(p)) 571 tracing_dl = 1; 572 else 573 tracing_dl = 0; 574 575 wakeup_task = p; 576 get_task_struct(wakeup_task); 577 578 local_save_flags(flags); 579 580 data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu); 581 data->preempt_timestamp = ftrace_now(cpu); 582 tracing_sched_wakeup_trace(wakeup_trace, p, current, flags, pc); 583 584 /* 585 * We must be careful in using CALLER_ADDR2. But since wake_up 586 * is not called by an assembly function (where as schedule is) 587 * it should be safe to use it here. 588 */ 589 __trace_function(wakeup_trace, CALLER_ADDR1, CALLER_ADDR2, flags, pc); 590 591 out_locked: 592 arch_spin_unlock(&wakeup_lock); 593 out: 594 atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); 595 } 596 597 static void start_wakeup_tracer(struct trace_array *tr) 598 { 599 int ret; 600 601 ret = register_trace_sched_wakeup(probe_wakeup, NULL); 602 if (ret) { 603 pr_info("wakeup trace: Couldn't activate tracepoint" 604 " probe to kernel_sched_wakeup\n"); 605 return; 606 } 607 608 ret = register_trace_sched_wakeup_new(probe_wakeup, NULL); 609 if (ret) { 610 pr_info("wakeup trace: Couldn't activate tracepoint" 611 " probe to kernel_sched_wakeup_new\n"); 612 goto fail_deprobe; 613 } 614 615 ret = register_trace_sched_switch(probe_wakeup_sched_switch, NULL); 616 if (ret) { 617 pr_info("sched trace: Couldn't activate tracepoint" 618 " probe to kernel_sched_switch\n"); 619 goto fail_deprobe_wake_new; 620 } 621 622 ret = register_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL); 623 if (ret) { 624 pr_info("wakeup trace: Couldn't activate tracepoint" 625 " probe to kernel_sched_migrate_task\n"); 626 return; 627 } 628 629 wakeup_reset(tr); 630 631 /* 632 * Don't let the tracer_enabled = 1 show up before 633 * the wakeup_task is reset. This may be overkill since 634 * wakeup_reset does a spin_unlock after setting the 635 * wakeup_task to NULL, but I want to be safe. 636 * This is a slow path anyway. 637 */ 638 smp_wmb(); 639 640 if (start_func_tracer(tr, is_graph())) 641 printk(KERN_ERR "failed to start wakeup tracer\n"); 642 643 return; 644 fail_deprobe_wake_new: 645 unregister_trace_sched_wakeup_new(probe_wakeup, NULL); 646 fail_deprobe: 647 unregister_trace_sched_wakeup(probe_wakeup, NULL); 648 } 649 650 static void stop_wakeup_tracer(struct trace_array *tr) 651 { 652 tracer_enabled = 0; 653 stop_func_tracer(tr, is_graph()); 654 unregister_trace_sched_switch(probe_wakeup_sched_switch, NULL); 655 unregister_trace_sched_wakeup_new(probe_wakeup, NULL); 656 unregister_trace_sched_wakeup(probe_wakeup, NULL); 657 unregister_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL); 658 } 659 660 static bool wakeup_busy; 661 662 static int __wakeup_tracer_init(struct trace_array *tr) 663 { 664 save_flags = trace_flags; 665 666 /* non overwrite screws up the latency tracers */ 667 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1); 668 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1); 669 670 tr->max_latency = 0; 671 wakeup_trace = tr; 672 ftrace_init_array_ops(tr, wakeup_tracer_call); 673 start_wakeup_tracer(tr); 674 675 wakeup_busy = true; 676 return 0; 677 } 678 679 static int wakeup_tracer_init(struct trace_array *tr) 680 { 681 if (wakeup_busy) 682 return -EBUSY; 683 684 wakeup_dl = 0; 685 wakeup_rt = 0; 686 return __wakeup_tracer_init(tr); 687 } 688 689 static int wakeup_rt_tracer_init(struct trace_array *tr) 690 { 691 if (wakeup_busy) 692 return -EBUSY; 693 694 wakeup_dl = 0; 695 wakeup_rt = 1; 696 return __wakeup_tracer_init(tr); 697 } 698 699 static int wakeup_dl_tracer_init(struct trace_array *tr) 700 { 701 if (wakeup_busy) 702 return -EBUSY; 703 704 wakeup_dl = 1; 705 wakeup_rt = 0; 706 return __wakeup_tracer_init(tr); 707 } 708 709 static void wakeup_tracer_reset(struct trace_array *tr) 710 { 711 int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT; 712 int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE; 713 714 stop_wakeup_tracer(tr); 715 /* make sure we put back any tasks we are tracing */ 716 wakeup_reset(tr); 717 718 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag); 719 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag); 720 ftrace_reset_array_ops(tr); 721 wakeup_busy = false; 722 } 723 724 static void wakeup_tracer_start(struct trace_array *tr) 725 { 726 wakeup_reset(tr); 727 tracer_enabled = 1; 728 } 729 730 static void wakeup_tracer_stop(struct trace_array *tr) 731 { 732 tracer_enabled = 0; 733 } 734 735 static struct tracer wakeup_tracer __read_mostly = 736 { 737 .name = "wakeup", 738 .init = wakeup_tracer_init, 739 .reset = wakeup_tracer_reset, 740 .start = wakeup_tracer_start, 741 .stop = wakeup_tracer_stop, 742 .print_max = true, 743 .print_header = wakeup_print_header, 744 .print_line = wakeup_print_line, 745 .flags = &tracer_flags, 746 .set_flag = wakeup_set_flag, 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 .flags = &tracer_flags, 768 .set_flag = wakeup_set_flag, 769 .flag_changed = wakeup_flag_changed, 770 #ifdef CONFIG_FTRACE_SELFTEST 771 .selftest = trace_selftest_startup_wakeup, 772 #endif 773 .open = wakeup_trace_open, 774 .close = wakeup_trace_close, 775 .allow_instances = true, 776 .use_max_tr = true, 777 }; 778 779 static struct tracer wakeup_dl_tracer __read_mostly = 780 { 781 .name = "wakeup_dl", 782 .init = wakeup_dl_tracer_init, 783 .reset = wakeup_tracer_reset, 784 .start = wakeup_tracer_start, 785 .stop = wakeup_tracer_stop, 786 .print_max = true, 787 .print_header = wakeup_print_header, 788 .print_line = wakeup_print_line, 789 .flags = &tracer_flags, 790 .set_flag = wakeup_set_flag, 791 .flag_changed = wakeup_flag_changed, 792 #ifdef CONFIG_FTRACE_SELFTEST 793 .selftest = trace_selftest_startup_wakeup, 794 #endif 795 .open = wakeup_trace_open, 796 .close = wakeup_trace_close, 797 .use_max_tr = true, 798 }; 799 800 __init static int init_wakeup_tracer(void) 801 { 802 int ret; 803 804 ret = register_tracer(&wakeup_tracer); 805 if (ret) 806 return ret; 807 808 ret = register_tracer(&wakeup_rt_tracer); 809 if (ret) 810 return ret; 811 812 ret = register_tracer(&wakeup_dl_tracer); 813 if (ret) 814 return ret; 815 816 return 0; 817 } 818 core_initcall(init_wakeup_tracer); 819