1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * trace task wakeup timings 4 * 5 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> 6 * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com> 7 * 8 * Based on code from the latency_tracer, that is: 9 * 10 * Copyright (C) 2004-2006 Ingo Molnar 11 * Copyright (C) 2004 Nadia Yvette Chambers 12 */ 13 #include <linux/module.h> 14 #include <linux/kallsyms.h> 15 #include <linux/uaccess.h> 16 #include <linux/ftrace.h> 17 #include <linux/sched/rt.h> 18 #include <linux/sched/deadline.h> 19 #include <trace/events/sched.h> 20 #include "trace.h" 21 22 static struct trace_array *wakeup_trace; 23 static int __read_mostly tracer_enabled; 24 25 static struct task_struct *wakeup_task; 26 static int wakeup_cpu; 27 static int wakeup_current_cpu; 28 static unsigned wakeup_prio = -1; 29 static int wakeup_rt; 30 static int wakeup_dl; 31 static int tracing_dl = 0; 32 33 static arch_spinlock_t wakeup_lock = 34 (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; 35 36 static void wakeup_reset(struct trace_array *tr); 37 static void __wakeup_reset(struct trace_array *tr); 38 static int start_func_tracer(struct trace_array *tr, int graph); 39 static void stop_func_tracer(struct trace_array *tr, int graph); 40 41 static int save_flags; 42 43 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 44 # define is_graph(tr) ((tr)->trace_flags & TRACE_ITER_DISPLAY_GRAPH) 45 #else 46 # define is_graph(tr) false 47 #endif 48 49 #ifdef CONFIG_FUNCTION_TRACER 50 51 static bool function_enabled; 52 53 /* 54 * Prologue for the wakeup function tracers. 55 * 56 * Returns 1 if it is OK to continue, and preemption 57 * is disabled and data->disabled is incremented. 58 * 0 if the trace is to be ignored, and preemption 59 * is not disabled and data->disabled is 60 * kept the same. 61 * 62 * Note, this function is also used outside this ifdef but 63 * inside the #ifdef of the function graph tracer below. 64 * This is OK, since the function graph tracer is 65 * dependent on the function tracer. 66 */ 67 static int 68 func_prolog_preempt_disable(struct trace_array *tr, 69 struct trace_array_cpu **data, 70 int *pc) 71 { 72 long disabled; 73 int cpu; 74 75 if (likely(!wakeup_task)) 76 return 0; 77 78 *pc = preempt_count(); 79 preempt_disable_notrace(); 80 81 cpu = raw_smp_processor_id(); 82 if (cpu != wakeup_current_cpu) 83 goto out_enable; 84 85 *data = per_cpu_ptr(tr->array_buffer.data, cpu); 86 disabled = atomic_inc_return(&(*data)->disabled); 87 if (unlikely(disabled != 1)) 88 goto out; 89 90 return 1; 91 92 out: 93 atomic_dec(&(*data)->disabled); 94 95 out_enable: 96 preempt_enable_notrace(); 97 return 0; 98 } 99 100 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 101 102 static int wakeup_display_graph(struct trace_array *tr, int set) 103 { 104 if (!(is_graph(tr) ^ set)) 105 return 0; 106 107 stop_func_tracer(tr, !set); 108 109 wakeup_reset(wakeup_trace); 110 tr->max_latency = 0; 111 112 return start_func_tracer(tr, set); 113 } 114 115 static int wakeup_graph_entry(struct ftrace_graph_ent *trace) 116 { 117 struct trace_array *tr = wakeup_trace; 118 struct trace_array_cpu *data; 119 unsigned long flags; 120 int pc, ret = 0; 121 122 if (ftrace_graph_ignore_func(trace)) 123 return 0; 124 /* 125 * Do not trace a function if it's filtered by set_graph_notrace. 126 * Make the index of ret stack negative to indicate that it should 127 * ignore further functions. But it needs its own ret stack entry 128 * to recover the original index in order to continue tracing after 129 * returning from the function. 130 */ 131 if (ftrace_graph_notrace_addr(trace->func)) 132 return 1; 133 134 if (!func_prolog_preempt_disable(tr, &data, &pc)) 135 return 0; 136 137 local_save_flags(flags); 138 ret = __trace_graph_entry(tr, trace, flags, pc); 139 atomic_dec(&data->disabled); 140 preempt_enable_notrace(); 141 142 return ret; 143 } 144 145 static void wakeup_graph_return(struct ftrace_graph_ret *trace) 146 { 147 struct trace_array *tr = wakeup_trace; 148 struct trace_array_cpu *data; 149 unsigned long flags; 150 int pc; 151 152 ftrace_graph_addr_finish(trace); 153 154 if (!func_prolog_preempt_disable(tr, &data, &pc)) 155 return; 156 157 local_save_flags(flags); 158 __trace_graph_return(tr, trace, flags, pc); 159 atomic_dec(&data->disabled); 160 161 preempt_enable_notrace(); 162 return; 163 } 164 165 static struct fgraph_ops fgraph_wakeup_ops = { 166 .entryfunc = &wakeup_graph_entry, 167 .retfunc = &wakeup_graph_return, 168 }; 169 170 static void wakeup_trace_open(struct trace_iterator *iter) 171 { 172 if (is_graph(iter->tr)) 173 graph_trace_open(iter); 174 } 175 176 static void wakeup_trace_close(struct trace_iterator *iter) 177 { 178 if (iter->private) 179 graph_trace_close(iter); 180 } 181 182 #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_PROC | \ 183 TRACE_GRAPH_PRINT_CPU | \ 184 TRACE_GRAPH_PRINT_REL_TIME | \ 185 TRACE_GRAPH_PRINT_DURATION | \ 186 TRACE_GRAPH_PRINT_OVERHEAD | \ 187 TRACE_GRAPH_PRINT_IRQS) 188 189 static enum print_line_t wakeup_print_line(struct trace_iterator *iter) 190 { 191 /* 192 * In graph mode call the graph tracer output function, 193 * otherwise go with the TRACE_FN event handler 194 */ 195 if (is_graph(iter->tr)) 196 return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS); 197 198 return TRACE_TYPE_UNHANDLED; 199 } 200 201 static void wakeup_print_header(struct seq_file *s) 202 { 203 if (is_graph(wakeup_trace)) 204 print_graph_headers_flags(s, GRAPH_TRACER_FLAGS); 205 else 206 trace_default_header(s); 207 } 208 #endif /* else CONFIG_FUNCTION_GRAPH_TRACER */ 209 210 /* 211 * wakeup uses its own tracer function to keep the overhead down: 212 */ 213 static void 214 wakeup_tracer_call(unsigned long ip, unsigned long parent_ip, 215 struct ftrace_ops *op, struct ftrace_regs *fregs) 216 { 217 struct trace_array *tr = wakeup_trace; 218 struct trace_array_cpu *data; 219 unsigned long flags; 220 int pc; 221 222 if (!func_prolog_preempt_disable(tr, &data, &pc)) 223 return; 224 225 local_irq_save(flags); 226 trace_function(tr, ip, parent_ip, flags, pc); 227 local_irq_restore(flags); 228 229 atomic_dec(&data->disabled); 230 preempt_enable_notrace(); 231 } 232 233 static int register_wakeup_function(struct trace_array *tr, int graph, int set) 234 { 235 int ret; 236 237 /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */ 238 if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION))) 239 return 0; 240 241 if (graph) 242 ret = register_ftrace_graph(&fgraph_wakeup_ops); 243 else 244 ret = register_ftrace_function(tr->ops); 245 246 if (!ret) 247 function_enabled = true; 248 249 return ret; 250 } 251 252 static void unregister_wakeup_function(struct trace_array *tr, int graph) 253 { 254 if (!function_enabled) 255 return; 256 257 if (graph) 258 unregister_ftrace_graph(&fgraph_wakeup_ops); 259 else 260 unregister_ftrace_function(tr->ops); 261 262 function_enabled = false; 263 } 264 265 static int wakeup_function_set(struct trace_array *tr, u32 mask, int set) 266 { 267 if (!(mask & TRACE_ITER_FUNCTION)) 268 return 0; 269 270 if (set) 271 register_wakeup_function(tr, is_graph(tr), 1); 272 else 273 unregister_wakeup_function(tr, is_graph(tr)); 274 return 1; 275 } 276 #else /* CONFIG_FUNCTION_TRACER */ 277 static int register_wakeup_function(struct trace_array *tr, int graph, int set) 278 { 279 return 0; 280 } 281 static void unregister_wakeup_function(struct trace_array *tr, int graph) { } 282 static int wakeup_function_set(struct trace_array *tr, u32 mask, int set) 283 { 284 return 0; 285 } 286 #endif /* else CONFIG_FUNCTION_TRACER */ 287 288 #ifndef CONFIG_FUNCTION_GRAPH_TRACER 289 static enum print_line_t wakeup_print_line(struct trace_iterator *iter) 290 { 291 return TRACE_TYPE_UNHANDLED; 292 } 293 294 static void wakeup_trace_open(struct trace_iterator *iter) { } 295 static void wakeup_trace_close(struct trace_iterator *iter) { } 296 297 static void wakeup_print_header(struct seq_file *s) 298 { 299 trace_default_header(s); 300 } 301 #endif /* !CONFIG_FUNCTION_GRAPH_TRACER */ 302 303 static void 304 __trace_function(struct trace_array *tr, 305 unsigned long ip, unsigned long parent_ip, 306 unsigned long flags, int pc) 307 { 308 if (is_graph(tr)) 309 trace_graph_function(tr, ip, parent_ip, flags, pc); 310 else 311 trace_function(tr, ip, parent_ip, flags, pc); 312 } 313 314 static int wakeup_flag_changed(struct trace_array *tr, u32 mask, int set) 315 { 316 struct tracer *tracer = tr->current_trace; 317 318 if (wakeup_function_set(tr, mask, set)) 319 return 0; 320 321 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 322 if (mask & TRACE_ITER_DISPLAY_GRAPH) 323 return wakeup_display_graph(tr, set); 324 #endif 325 326 return trace_keep_overwrite(tracer, mask, set); 327 } 328 329 static int start_func_tracer(struct trace_array *tr, int graph) 330 { 331 int ret; 332 333 ret = register_wakeup_function(tr, graph, 0); 334 335 if (!ret && tracing_is_enabled()) 336 tracer_enabled = 1; 337 else 338 tracer_enabled = 0; 339 340 return ret; 341 } 342 343 static void stop_func_tracer(struct trace_array *tr, int graph) 344 { 345 tracer_enabled = 0; 346 347 unregister_wakeup_function(tr, graph); 348 } 349 350 /* 351 * Should this new latency be reported/recorded? 352 */ 353 static bool report_latency(struct trace_array *tr, u64 delta) 354 { 355 if (tracing_thresh) { 356 if (delta < tracing_thresh) 357 return false; 358 } else { 359 if (delta <= tr->max_latency) 360 return false; 361 } 362 return true; 363 } 364 365 static void 366 probe_wakeup_migrate_task(void *ignore, struct task_struct *task, int cpu) 367 { 368 if (task != wakeup_task) 369 return; 370 371 wakeup_current_cpu = cpu; 372 } 373 374 static void 375 tracing_sched_switch_trace(struct trace_array *tr, 376 struct task_struct *prev, 377 struct task_struct *next, 378 unsigned long flags, int pc) 379 { 380 struct trace_event_call *call = &event_context_switch; 381 struct trace_buffer *buffer = tr->array_buffer.buffer; 382 struct ring_buffer_event *event; 383 struct ctx_switch_entry *entry; 384 385 event = trace_buffer_lock_reserve(buffer, TRACE_CTX, 386 sizeof(*entry), flags, pc); 387 if (!event) 388 return; 389 entry = ring_buffer_event_data(event); 390 entry->prev_pid = prev->pid; 391 entry->prev_prio = prev->prio; 392 entry->prev_state = task_state_index(prev); 393 entry->next_pid = next->pid; 394 entry->next_prio = next->prio; 395 entry->next_state = task_state_index(next); 396 entry->next_cpu = task_cpu(next); 397 398 if (!call_filter_check_discard(call, entry, buffer, event)) 399 trace_buffer_unlock_commit(tr, buffer, event, flags, pc); 400 } 401 402 static void 403 tracing_sched_wakeup_trace(struct trace_array *tr, 404 struct task_struct *wakee, 405 struct task_struct *curr, 406 unsigned long flags, int pc) 407 { 408 struct trace_event_call *call = &event_wakeup; 409 struct ring_buffer_event *event; 410 struct ctx_switch_entry *entry; 411 struct trace_buffer *buffer = tr->array_buffer.buffer; 412 413 event = trace_buffer_lock_reserve(buffer, TRACE_WAKE, 414 sizeof(*entry), flags, pc); 415 if (!event) 416 return; 417 entry = ring_buffer_event_data(event); 418 entry->prev_pid = curr->pid; 419 entry->prev_prio = curr->prio; 420 entry->prev_state = task_state_index(curr); 421 entry->next_pid = wakee->pid; 422 entry->next_prio = wakee->prio; 423 entry->next_state = task_state_index(wakee); 424 entry->next_cpu = task_cpu(wakee); 425 426 if (!call_filter_check_discard(call, entry, buffer, event)) 427 trace_buffer_unlock_commit(tr, buffer, event, flags, pc); 428 } 429 430 static void notrace 431 probe_wakeup_sched_switch(void *ignore, bool preempt, 432 struct task_struct *prev, struct task_struct *next) 433 { 434 struct trace_array_cpu *data; 435 u64 T0, T1, delta; 436 unsigned long flags; 437 long disabled; 438 int cpu; 439 int pc; 440 441 tracing_record_cmdline(prev); 442 443 if (unlikely(!tracer_enabled)) 444 return; 445 446 /* 447 * When we start a new trace, we set wakeup_task to NULL 448 * and then set tracer_enabled = 1. We want to make sure 449 * that another CPU does not see the tracer_enabled = 1 450 * and the wakeup_task with an older task, that might 451 * actually be the same as next. 452 */ 453 smp_rmb(); 454 455 if (next != wakeup_task) 456 return; 457 458 pc = preempt_count(); 459 460 /* disable local data, not wakeup_cpu data */ 461 cpu = raw_smp_processor_id(); 462 disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->array_buffer.data, cpu)->disabled); 463 if (likely(disabled != 1)) 464 goto out; 465 466 local_irq_save(flags); 467 arch_spin_lock(&wakeup_lock); 468 469 /* We could race with grabbing wakeup_lock */ 470 if (unlikely(!tracer_enabled || next != wakeup_task)) 471 goto out_unlock; 472 473 /* The task we are waiting for is waking up */ 474 data = per_cpu_ptr(wakeup_trace->array_buffer.data, wakeup_cpu); 475 476 __trace_function(wakeup_trace, CALLER_ADDR0, CALLER_ADDR1, flags, pc); 477 tracing_sched_switch_trace(wakeup_trace, prev, next, flags, pc); 478 __trace_stack(wakeup_trace, flags, 0, pc); 479 480 T0 = data->preempt_timestamp; 481 T1 = ftrace_now(cpu); 482 delta = T1-T0; 483 484 if (!report_latency(wakeup_trace, delta)) 485 goto out_unlock; 486 487 if (likely(!is_tracing_stopped())) { 488 wakeup_trace->max_latency = delta; 489 update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu, NULL); 490 } 491 492 out_unlock: 493 __wakeup_reset(wakeup_trace); 494 arch_spin_unlock(&wakeup_lock); 495 local_irq_restore(flags); 496 out: 497 atomic_dec(&per_cpu_ptr(wakeup_trace->array_buffer.data, cpu)->disabled); 498 } 499 500 static void __wakeup_reset(struct trace_array *tr) 501 { 502 wakeup_cpu = -1; 503 wakeup_prio = -1; 504 tracing_dl = 0; 505 506 if (wakeup_task) 507 put_task_struct(wakeup_task); 508 509 wakeup_task = NULL; 510 } 511 512 static void wakeup_reset(struct trace_array *tr) 513 { 514 unsigned long flags; 515 516 tracing_reset_online_cpus(&tr->array_buffer); 517 518 local_irq_save(flags); 519 arch_spin_lock(&wakeup_lock); 520 __wakeup_reset(tr); 521 arch_spin_unlock(&wakeup_lock); 522 local_irq_restore(flags); 523 } 524 525 static void 526 probe_wakeup(void *ignore, struct task_struct *p) 527 { 528 struct trace_array_cpu *data; 529 int cpu = smp_processor_id(); 530 unsigned long flags; 531 long disabled; 532 int pc; 533 534 if (likely(!tracer_enabled)) 535 return; 536 537 tracing_record_cmdline(p); 538 tracing_record_cmdline(current); 539 540 /* 541 * Semantic is like this: 542 * - wakeup tracer handles all tasks in the system, independently 543 * from their scheduling class; 544 * - wakeup_rt tracer handles tasks belonging to sched_dl and 545 * sched_rt class; 546 * - wakeup_dl handles tasks belonging to sched_dl class only. 547 */ 548 if (tracing_dl || (wakeup_dl && !dl_task(p)) || 549 (wakeup_rt && !dl_task(p) && !rt_task(p)) || 550 (!dl_task(p) && (p->prio >= wakeup_prio || p->prio >= current->prio))) 551 return; 552 553 pc = preempt_count(); 554 disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->array_buffer.data, cpu)->disabled); 555 if (unlikely(disabled != 1)) 556 goto out; 557 558 /* interrupts should be off from try_to_wake_up */ 559 arch_spin_lock(&wakeup_lock); 560 561 /* check for races. */ 562 if (!tracer_enabled || tracing_dl || 563 (!dl_task(p) && p->prio >= wakeup_prio)) 564 goto out_locked; 565 566 /* reset the trace */ 567 __wakeup_reset(wakeup_trace); 568 569 wakeup_cpu = task_cpu(p); 570 wakeup_current_cpu = wakeup_cpu; 571 wakeup_prio = p->prio; 572 573 /* 574 * Once you start tracing a -deadline task, don't bother tracing 575 * another task until the first one wakes up. 576 */ 577 if (dl_task(p)) 578 tracing_dl = 1; 579 else 580 tracing_dl = 0; 581 582 wakeup_task = get_task_struct(p); 583 584 local_save_flags(flags); 585 586 data = per_cpu_ptr(wakeup_trace->array_buffer.data, wakeup_cpu); 587 data->preempt_timestamp = ftrace_now(cpu); 588 tracing_sched_wakeup_trace(wakeup_trace, p, current, flags, pc); 589 __trace_stack(wakeup_trace, flags, 0, pc); 590 591 /* 592 * We must be careful in using CALLER_ADDR2. But since wake_up 593 * is not called by an assembly function (where as schedule is) 594 * it should be safe to use it here. 595 */ 596 __trace_function(wakeup_trace, CALLER_ADDR1, CALLER_ADDR2, flags, pc); 597 598 out_locked: 599 arch_spin_unlock(&wakeup_lock); 600 out: 601 atomic_dec(&per_cpu_ptr(wakeup_trace->array_buffer.data, cpu)->disabled); 602 } 603 604 static void start_wakeup_tracer(struct trace_array *tr) 605 { 606 int ret; 607 608 ret = register_trace_sched_wakeup(probe_wakeup, NULL); 609 if (ret) { 610 pr_info("wakeup trace: Couldn't activate tracepoint" 611 " probe to kernel_sched_wakeup\n"); 612 return; 613 } 614 615 ret = register_trace_sched_wakeup_new(probe_wakeup, NULL); 616 if (ret) { 617 pr_info("wakeup trace: Couldn't activate tracepoint" 618 " probe to kernel_sched_wakeup_new\n"); 619 goto fail_deprobe; 620 } 621 622 ret = register_trace_sched_switch(probe_wakeup_sched_switch, NULL); 623 if (ret) { 624 pr_info("sched trace: Couldn't activate tracepoint" 625 " probe to kernel_sched_switch\n"); 626 goto fail_deprobe_wake_new; 627 } 628 629 ret = register_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL); 630 if (ret) { 631 pr_info("wakeup trace: Couldn't activate tracepoint" 632 " probe to kernel_sched_migrate_task\n"); 633 goto fail_deprobe_sched_switch; 634 } 635 636 wakeup_reset(tr); 637 638 /* 639 * Don't let the tracer_enabled = 1 show up before 640 * the wakeup_task is reset. This may be overkill since 641 * wakeup_reset does a spin_unlock after setting the 642 * wakeup_task to NULL, but I want to be safe. 643 * This is a slow path anyway. 644 */ 645 smp_wmb(); 646 647 if (start_func_tracer(tr, is_graph(tr))) 648 printk(KERN_ERR "failed to start wakeup tracer\n"); 649 650 return; 651 fail_deprobe_sched_switch: 652 unregister_trace_sched_switch(probe_wakeup_sched_switch, NULL); 653 fail_deprobe_wake_new: 654 unregister_trace_sched_wakeup_new(probe_wakeup, NULL); 655 fail_deprobe: 656 unregister_trace_sched_wakeup(probe_wakeup, NULL); 657 } 658 659 static void stop_wakeup_tracer(struct trace_array *tr) 660 { 661 tracer_enabled = 0; 662 stop_func_tracer(tr, is_graph(tr)); 663 unregister_trace_sched_switch(probe_wakeup_sched_switch, NULL); 664 unregister_trace_sched_wakeup_new(probe_wakeup, NULL); 665 unregister_trace_sched_wakeup(probe_wakeup, NULL); 666 unregister_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL); 667 } 668 669 static bool wakeup_busy; 670 671 static int __wakeup_tracer_init(struct trace_array *tr) 672 { 673 save_flags = tr->trace_flags; 674 675 /* non overwrite screws up the latency tracers */ 676 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1); 677 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1); 678 679 tr->max_latency = 0; 680 wakeup_trace = tr; 681 ftrace_init_array_ops(tr, wakeup_tracer_call); 682 start_wakeup_tracer(tr); 683 684 wakeup_busy = true; 685 return 0; 686 } 687 688 static int wakeup_tracer_init(struct trace_array *tr) 689 { 690 if (wakeup_busy) 691 return -EBUSY; 692 693 wakeup_dl = 0; 694 wakeup_rt = 0; 695 return __wakeup_tracer_init(tr); 696 } 697 698 static int wakeup_rt_tracer_init(struct trace_array *tr) 699 { 700 if (wakeup_busy) 701 return -EBUSY; 702 703 wakeup_dl = 0; 704 wakeup_rt = 1; 705 return __wakeup_tracer_init(tr); 706 } 707 708 static int wakeup_dl_tracer_init(struct trace_array *tr) 709 { 710 if (wakeup_busy) 711 return -EBUSY; 712 713 wakeup_dl = 1; 714 wakeup_rt = 0; 715 return __wakeup_tracer_init(tr); 716 } 717 718 static void wakeup_tracer_reset(struct trace_array *tr) 719 { 720 int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT; 721 int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE; 722 723 stop_wakeup_tracer(tr); 724 /* make sure we put back any tasks we are tracing */ 725 wakeup_reset(tr); 726 727 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag); 728 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag); 729 ftrace_reset_array_ops(tr); 730 wakeup_busy = false; 731 } 732 733 static void wakeup_tracer_start(struct trace_array *tr) 734 { 735 wakeup_reset(tr); 736 tracer_enabled = 1; 737 } 738 739 static void wakeup_tracer_stop(struct trace_array *tr) 740 { 741 tracer_enabled = 0; 742 } 743 744 static struct tracer wakeup_tracer __read_mostly = 745 { 746 .name = "wakeup", 747 .init = wakeup_tracer_init, 748 .reset = wakeup_tracer_reset, 749 .start = wakeup_tracer_start, 750 .stop = wakeup_tracer_stop, 751 .print_max = true, 752 .print_header = wakeup_print_header, 753 .print_line = wakeup_print_line, 754 .flag_changed = wakeup_flag_changed, 755 #ifdef CONFIG_FTRACE_SELFTEST 756 .selftest = trace_selftest_startup_wakeup, 757 #endif 758 .open = wakeup_trace_open, 759 .close = wakeup_trace_close, 760 .allow_instances = true, 761 .use_max_tr = true, 762 }; 763 764 static struct tracer wakeup_rt_tracer __read_mostly = 765 { 766 .name = "wakeup_rt", 767 .init = wakeup_rt_tracer_init, 768 .reset = wakeup_tracer_reset, 769 .start = wakeup_tracer_start, 770 .stop = wakeup_tracer_stop, 771 .print_max = true, 772 .print_header = wakeup_print_header, 773 .print_line = wakeup_print_line, 774 .flag_changed = wakeup_flag_changed, 775 #ifdef CONFIG_FTRACE_SELFTEST 776 .selftest = trace_selftest_startup_wakeup, 777 #endif 778 .open = wakeup_trace_open, 779 .close = wakeup_trace_close, 780 .allow_instances = true, 781 .use_max_tr = true, 782 }; 783 784 static struct tracer wakeup_dl_tracer __read_mostly = 785 { 786 .name = "wakeup_dl", 787 .init = wakeup_dl_tracer_init, 788 .reset = wakeup_tracer_reset, 789 .start = wakeup_tracer_start, 790 .stop = wakeup_tracer_stop, 791 .print_max = true, 792 .print_header = wakeup_print_header, 793 .print_line = wakeup_print_line, 794 .flag_changed = wakeup_flag_changed, 795 #ifdef CONFIG_FTRACE_SELFTEST 796 .selftest = trace_selftest_startup_wakeup, 797 #endif 798 .open = wakeup_trace_open, 799 .close = wakeup_trace_close, 800 .allow_instances = true, 801 .use_max_tr = true, 802 }; 803 804 __init static int init_wakeup_tracer(void) 805 { 806 int ret; 807 808 ret = register_tracer(&wakeup_tracer); 809 if (ret) 810 return ret; 811 812 ret = register_tracer(&wakeup_rt_tracer); 813 if (ret) 814 return ret; 815 816 ret = register_tracer(&wakeup_dl_tracer); 817 if (ret) 818 return ret; 819 820 return 0; 821 } 822 core_initcall(init_wakeup_tracer); 823