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 39 static int save_flags; 40 41 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 42 static int wakeup_display_graph(struct trace_array *tr, int set); 43 # define is_graph(tr) ((tr)->trace_flags & TRACE_ITER_DISPLAY_GRAPH) 44 #else 45 static inline int wakeup_display_graph(struct trace_array *tr, int set) 46 { 47 return 0; 48 } 49 # define is_graph(tr) false 50 #endif 51 52 53 #ifdef CONFIG_FUNCTION_TRACER 54 55 static int wakeup_graph_entry(struct ftrace_graph_ent *trace); 56 static void wakeup_graph_return(struct ftrace_graph_ret *trace); 57 58 static bool function_enabled; 59 60 /* 61 * Prologue for the wakeup function tracers. 62 * 63 * Returns 1 if it is OK to continue, and preemption 64 * is disabled and data->disabled is incremented. 65 * 0 if the trace is to be ignored, and preemption 66 * is not disabled and data->disabled is 67 * kept the same. 68 * 69 * Note, this function is also used outside this ifdef but 70 * inside the #ifdef of the function graph tracer below. 71 * This is OK, since the function graph tracer is 72 * dependent on the function tracer. 73 */ 74 static int 75 func_prolog_preempt_disable(struct trace_array *tr, 76 struct trace_array_cpu **data, 77 int *pc) 78 { 79 long disabled; 80 int cpu; 81 82 if (likely(!wakeup_task)) 83 return 0; 84 85 *pc = preempt_count(); 86 preempt_disable_notrace(); 87 88 cpu = raw_smp_processor_id(); 89 if (cpu != wakeup_current_cpu) 90 goto out_enable; 91 92 *data = per_cpu_ptr(tr->trace_buffer.data, cpu); 93 disabled = atomic_inc_return(&(*data)->disabled); 94 if (unlikely(disabled != 1)) 95 goto out; 96 97 return 1; 98 99 out: 100 atomic_dec(&(*data)->disabled); 101 102 out_enable: 103 preempt_enable_notrace(); 104 return 0; 105 } 106 107 /* 108 * wakeup uses its own tracer function to keep the overhead down: 109 */ 110 static void 111 wakeup_tracer_call(unsigned long ip, unsigned long parent_ip, 112 struct ftrace_ops *op, struct pt_regs *pt_regs) 113 { 114 struct trace_array *tr = wakeup_trace; 115 struct trace_array_cpu *data; 116 unsigned long flags; 117 int pc; 118 119 if (!func_prolog_preempt_disable(tr, &data, &pc)) 120 return; 121 122 local_irq_save(flags); 123 trace_function(tr, ip, parent_ip, flags, pc); 124 local_irq_restore(flags); 125 126 atomic_dec(&data->disabled); 127 preempt_enable_notrace(); 128 } 129 130 static int register_wakeup_function(struct trace_array *tr, int graph, int set) 131 { 132 int ret; 133 134 /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */ 135 if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION))) 136 return 0; 137 138 if (graph) 139 ret = register_ftrace_graph(&wakeup_graph_return, 140 &wakeup_graph_entry); 141 else 142 ret = register_ftrace_function(tr->ops); 143 144 if (!ret) 145 function_enabled = true; 146 147 return ret; 148 } 149 150 static void unregister_wakeup_function(struct trace_array *tr, int graph) 151 { 152 if (!function_enabled) 153 return; 154 155 if (graph) 156 unregister_ftrace_graph(); 157 else 158 unregister_ftrace_function(tr->ops); 159 160 function_enabled = false; 161 } 162 163 static int wakeup_function_set(struct trace_array *tr, u32 mask, int set) 164 { 165 if (!(mask & TRACE_ITER_FUNCTION)) 166 return 0; 167 168 if (set) 169 register_wakeup_function(tr, is_graph(tr), 1); 170 else 171 unregister_wakeup_function(tr, is_graph(tr)); 172 return 1; 173 } 174 #else 175 static int register_wakeup_function(struct trace_array *tr, int graph, int set) 176 { 177 return 0; 178 } 179 static void unregister_wakeup_function(struct trace_array *tr, int graph) { } 180 static int wakeup_function_set(struct trace_array *tr, u32 mask, int set) 181 { 182 return 0; 183 } 184 #endif /* CONFIG_FUNCTION_TRACER */ 185 186 static int wakeup_flag_changed(struct trace_array *tr, u32 mask, int set) 187 { 188 struct tracer *tracer = tr->current_trace; 189 190 if (wakeup_function_set(tr, mask, set)) 191 return 0; 192 193 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 194 if (mask & TRACE_ITER_DISPLAY_GRAPH) 195 return wakeup_display_graph(tr, set); 196 #endif 197 198 return trace_keep_overwrite(tracer, mask, set); 199 } 200 201 static int start_func_tracer(struct trace_array *tr, int graph) 202 { 203 int ret; 204 205 ret = register_wakeup_function(tr, graph, 0); 206 207 if (!ret && tracing_is_enabled()) 208 tracer_enabled = 1; 209 else 210 tracer_enabled = 0; 211 212 return ret; 213 } 214 215 static void stop_func_tracer(struct trace_array *tr, int graph) 216 { 217 tracer_enabled = 0; 218 219 unregister_wakeup_function(tr, graph); 220 } 221 222 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 223 static int wakeup_display_graph(struct trace_array *tr, int set) 224 { 225 if (!(is_graph(tr) ^ set)) 226 return 0; 227 228 stop_func_tracer(tr, !set); 229 230 wakeup_reset(wakeup_trace); 231 tr->max_latency = 0; 232 233 return start_func_tracer(tr, set); 234 } 235 236 static int wakeup_graph_entry(struct ftrace_graph_ent *trace) 237 { 238 struct trace_array *tr = wakeup_trace; 239 struct trace_array_cpu *data; 240 unsigned long flags; 241 int pc, ret = 0; 242 243 if (ftrace_graph_ignore_func(trace)) 244 return 0; 245 /* 246 * Do not trace a function if it's filtered by set_graph_notrace. 247 * Make the index of ret stack negative to indicate that it should 248 * ignore further functions. But it needs its own ret stack entry 249 * to recover the original index in order to continue tracing after 250 * returning from the function. 251 */ 252 if (ftrace_graph_notrace_addr(trace->func)) 253 return 1; 254 255 if (!func_prolog_preempt_disable(tr, &data, &pc)) 256 return 0; 257 258 local_save_flags(flags); 259 ret = __trace_graph_entry(tr, trace, flags, pc); 260 atomic_dec(&data->disabled); 261 preempt_enable_notrace(); 262 263 return ret; 264 } 265 266 static void wakeup_graph_return(struct ftrace_graph_ret *trace) 267 { 268 struct trace_array *tr = wakeup_trace; 269 struct trace_array_cpu *data; 270 unsigned long flags; 271 int pc; 272 273 ftrace_graph_addr_finish(trace); 274 275 if (!func_prolog_preempt_disable(tr, &data, &pc)) 276 return; 277 278 local_save_flags(flags); 279 __trace_graph_return(tr, trace, flags, pc); 280 atomic_dec(&data->disabled); 281 282 preempt_enable_notrace(); 283 return; 284 } 285 286 static void wakeup_trace_open(struct trace_iterator *iter) 287 { 288 if (is_graph(iter->tr)) 289 graph_trace_open(iter); 290 } 291 292 static void wakeup_trace_close(struct trace_iterator *iter) 293 { 294 if (iter->private) 295 graph_trace_close(iter); 296 } 297 298 #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_PROC | \ 299 TRACE_GRAPH_PRINT_ABS_TIME | \ 300 TRACE_GRAPH_PRINT_DURATION) 301 302 static enum print_line_t wakeup_print_line(struct trace_iterator *iter) 303 { 304 /* 305 * In graph mode call the graph tracer output function, 306 * otherwise go with the TRACE_FN event handler 307 */ 308 if (is_graph(iter->tr)) 309 return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS); 310 311 return TRACE_TYPE_UNHANDLED; 312 } 313 314 static void wakeup_print_header(struct seq_file *s) 315 { 316 if (is_graph(wakeup_trace)) 317 print_graph_headers_flags(s, GRAPH_TRACER_FLAGS); 318 else 319 trace_default_header(s); 320 } 321 322 static void 323 __trace_function(struct trace_array *tr, 324 unsigned long ip, unsigned long parent_ip, 325 unsigned long flags, int pc) 326 { 327 if (is_graph(tr)) 328 trace_graph_function(tr, ip, parent_ip, flags, pc); 329 else 330 trace_function(tr, ip, parent_ip, flags, pc); 331 } 332 #else 333 #define __trace_function trace_function 334 335 static enum print_line_t wakeup_print_line(struct trace_iterator *iter) 336 { 337 return TRACE_TYPE_UNHANDLED; 338 } 339 340 static void wakeup_trace_open(struct trace_iterator *iter) { } 341 static void wakeup_trace_close(struct trace_iterator *iter) { } 342 343 #ifdef CONFIG_FUNCTION_TRACER 344 static int wakeup_graph_entry(struct ftrace_graph_ent *trace) 345 { 346 return -1; 347 } 348 static void wakeup_graph_return(struct ftrace_graph_ret *trace) { } 349 static void wakeup_print_header(struct seq_file *s) 350 { 351 trace_default_header(s); 352 } 353 #else 354 static void wakeup_print_header(struct seq_file *s) 355 { 356 trace_latency_header(s); 357 } 358 #endif /* CONFIG_FUNCTION_TRACER */ 359 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 360 361 /* 362 * Should this new latency be reported/recorded? 363 */ 364 static bool report_latency(struct trace_array *tr, u64 delta) 365 { 366 if (tracing_thresh) { 367 if (delta < tracing_thresh) 368 return false; 369 } else { 370 if (delta <= tr->max_latency) 371 return false; 372 } 373 return true; 374 } 375 376 static void 377 probe_wakeup_migrate_task(void *ignore, struct task_struct *task, int cpu) 378 { 379 if (task != wakeup_task) 380 return; 381 382 wakeup_current_cpu = cpu; 383 } 384 385 static void 386 tracing_sched_switch_trace(struct trace_array *tr, 387 struct task_struct *prev, 388 struct task_struct *next, 389 unsigned long flags, int pc) 390 { 391 struct trace_event_call *call = &event_context_switch; 392 struct ring_buffer *buffer = tr->trace_buffer.buffer; 393 struct ring_buffer_event *event; 394 struct ctx_switch_entry *entry; 395 396 event = trace_buffer_lock_reserve(buffer, TRACE_CTX, 397 sizeof(*entry), flags, pc); 398 if (!event) 399 return; 400 entry = ring_buffer_event_data(event); 401 entry->prev_pid = prev->pid; 402 entry->prev_prio = prev->prio; 403 entry->prev_state = task_state_index(prev); 404 entry->next_pid = next->pid; 405 entry->next_prio = next->prio; 406 entry->next_state = task_state_index(next); 407 entry->next_cpu = task_cpu(next); 408 409 if (!call_filter_check_discard(call, entry, buffer, event)) 410 trace_buffer_unlock_commit(tr, buffer, event, flags, pc); 411 } 412 413 static void 414 tracing_sched_wakeup_trace(struct trace_array *tr, 415 struct task_struct *wakee, 416 struct task_struct *curr, 417 unsigned long flags, int pc) 418 { 419 struct trace_event_call *call = &event_wakeup; 420 struct ring_buffer_event *event; 421 struct ctx_switch_entry *entry; 422 struct ring_buffer *buffer = tr->trace_buffer.buffer; 423 424 event = trace_buffer_lock_reserve(buffer, TRACE_WAKE, 425 sizeof(*entry), flags, pc); 426 if (!event) 427 return; 428 entry = ring_buffer_event_data(event); 429 entry->prev_pid = curr->pid; 430 entry->prev_prio = curr->prio; 431 entry->prev_state = task_state_index(curr); 432 entry->next_pid = wakee->pid; 433 entry->next_prio = wakee->prio; 434 entry->next_state = task_state_index(wakee); 435 entry->next_cpu = task_cpu(wakee); 436 437 if (!call_filter_check_discard(call, entry, buffer, event)) 438 trace_buffer_unlock_commit(tr, buffer, event, flags, pc); 439 } 440 441 static void notrace 442 probe_wakeup_sched_switch(void *ignore, bool preempt, 443 struct task_struct *prev, struct task_struct *next) 444 { 445 struct trace_array_cpu *data; 446 u64 T0, T1, delta; 447 unsigned long flags; 448 long disabled; 449 int cpu; 450 int pc; 451 452 tracing_record_cmdline(prev); 453 454 if (unlikely(!tracer_enabled)) 455 return; 456 457 /* 458 * When we start a new trace, we set wakeup_task to NULL 459 * and then set tracer_enabled = 1. We want to make sure 460 * that another CPU does not see the tracer_enabled = 1 461 * and the wakeup_task with an older task, that might 462 * actually be the same as next. 463 */ 464 smp_rmb(); 465 466 if (next != wakeup_task) 467 return; 468 469 pc = preempt_count(); 470 471 /* disable local data, not wakeup_cpu data */ 472 cpu = raw_smp_processor_id(); 473 disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); 474 if (likely(disabled != 1)) 475 goto out; 476 477 local_irq_save(flags); 478 arch_spin_lock(&wakeup_lock); 479 480 /* We could race with grabbing wakeup_lock */ 481 if (unlikely(!tracer_enabled || next != wakeup_task)) 482 goto out_unlock; 483 484 /* The task we are waiting for is waking up */ 485 data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu); 486 487 __trace_function(wakeup_trace, CALLER_ADDR0, CALLER_ADDR1, flags, pc); 488 tracing_sched_switch_trace(wakeup_trace, prev, next, flags, pc); 489 490 T0 = data->preempt_timestamp; 491 T1 = ftrace_now(cpu); 492 delta = T1-T0; 493 494 if (!report_latency(wakeup_trace, delta)) 495 goto out_unlock; 496 497 if (likely(!is_tracing_stopped())) { 498 wakeup_trace->max_latency = delta; 499 update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu); 500 } 501 502 out_unlock: 503 __wakeup_reset(wakeup_trace); 504 arch_spin_unlock(&wakeup_lock); 505 local_irq_restore(flags); 506 out: 507 atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); 508 } 509 510 static void __wakeup_reset(struct trace_array *tr) 511 { 512 wakeup_cpu = -1; 513 wakeup_prio = -1; 514 tracing_dl = 0; 515 516 if (wakeup_task) 517 put_task_struct(wakeup_task); 518 519 wakeup_task = NULL; 520 } 521 522 static void wakeup_reset(struct trace_array *tr) 523 { 524 unsigned long flags; 525 526 tracing_reset_online_cpus(&tr->trace_buffer); 527 528 local_irq_save(flags); 529 arch_spin_lock(&wakeup_lock); 530 __wakeup_reset(tr); 531 arch_spin_unlock(&wakeup_lock); 532 local_irq_restore(flags); 533 } 534 535 static void 536 probe_wakeup(void *ignore, struct task_struct *p) 537 { 538 struct trace_array_cpu *data; 539 int cpu = smp_processor_id(); 540 unsigned long flags; 541 long disabled; 542 int pc; 543 544 if (likely(!tracer_enabled)) 545 return; 546 547 tracing_record_cmdline(p); 548 tracing_record_cmdline(current); 549 550 /* 551 * Semantic is like this: 552 * - wakeup tracer handles all tasks in the system, independently 553 * from their scheduling class; 554 * - wakeup_rt tracer handles tasks belonging to sched_dl and 555 * sched_rt class; 556 * - wakeup_dl handles tasks belonging to sched_dl class only. 557 */ 558 if (tracing_dl || (wakeup_dl && !dl_task(p)) || 559 (wakeup_rt && !dl_task(p) && !rt_task(p)) || 560 (!dl_task(p) && (p->prio >= wakeup_prio || p->prio >= current->prio))) 561 return; 562 563 pc = preempt_count(); 564 disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); 565 if (unlikely(disabled != 1)) 566 goto out; 567 568 /* interrupts should be off from try_to_wake_up */ 569 arch_spin_lock(&wakeup_lock); 570 571 /* check for races. */ 572 if (!tracer_enabled || tracing_dl || 573 (!dl_task(p) && p->prio >= wakeup_prio)) 574 goto out_locked; 575 576 /* reset the trace */ 577 __wakeup_reset(wakeup_trace); 578 579 wakeup_cpu = task_cpu(p); 580 wakeup_current_cpu = wakeup_cpu; 581 wakeup_prio = p->prio; 582 583 /* 584 * Once you start tracing a -deadline task, don't bother tracing 585 * another task until the first one wakes up. 586 */ 587 if (dl_task(p)) 588 tracing_dl = 1; 589 else 590 tracing_dl = 0; 591 592 wakeup_task = p; 593 get_task_struct(wakeup_task); 594 595 local_save_flags(flags); 596 597 data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu); 598 data->preempt_timestamp = ftrace_now(cpu); 599 tracing_sched_wakeup_trace(wakeup_trace, p, current, flags, pc); 600 601 /* 602 * We must be careful in using CALLER_ADDR2. But since wake_up 603 * is not called by an assembly function (where as schedule is) 604 * it should be safe to use it here. 605 */ 606 __trace_function(wakeup_trace, CALLER_ADDR1, CALLER_ADDR2, flags, pc); 607 608 out_locked: 609 arch_spin_unlock(&wakeup_lock); 610 out: 611 atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); 612 } 613 614 static void start_wakeup_tracer(struct trace_array *tr) 615 { 616 int ret; 617 618 ret = register_trace_sched_wakeup(probe_wakeup, NULL); 619 if (ret) { 620 pr_info("wakeup trace: Couldn't activate tracepoint" 621 " probe to kernel_sched_wakeup\n"); 622 return; 623 } 624 625 ret = register_trace_sched_wakeup_new(probe_wakeup, NULL); 626 if (ret) { 627 pr_info("wakeup trace: Couldn't activate tracepoint" 628 " probe to kernel_sched_wakeup_new\n"); 629 goto fail_deprobe; 630 } 631 632 ret = register_trace_sched_switch(probe_wakeup_sched_switch, NULL); 633 if (ret) { 634 pr_info("sched trace: Couldn't activate tracepoint" 635 " probe to kernel_sched_switch\n"); 636 goto fail_deprobe_wake_new; 637 } 638 639 ret = register_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL); 640 if (ret) { 641 pr_info("wakeup trace: Couldn't activate tracepoint" 642 " probe to kernel_sched_migrate_task\n"); 643 return; 644 } 645 646 wakeup_reset(tr); 647 648 /* 649 * Don't let the tracer_enabled = 1 show up before 650 * the wakeup_task is reset. This may be overkill since 651 * wakeup_reset does a spin_unlock after setting the 652 * wakeup_task to NULL, but I want to be safe. 653 * This is a slow path anyway. 654 */ 655 smp_wmb(); 656 657 if (start_func_tracer(tr, is_graph(tr))) 658 printk(KERN_ERR "failed to start wakeup tracer\n"); 659 660 return; 661 fail_deprobe_wake_new: 662 unregister_trace_sched_wakeup_new(probe_wakeup, NULL); 663 fail_deprobe: 664 unregister_trace_sched_wakeup(probe_wakeup, NULL); 665 } 666 667 static void stop_wakeup_tracer(struct trace_array *tr) 668 { 669 tracer_enabled = 0; 670 stop_func_tracer(tr, is_graph(tr)); 671 unregister_trace_sched_switch(probe_wakeup_sched_switch, NULL); 672 unregister_trace_sched_wakeup_new(probe_wakeup, NULL); 673 unregister_trace_sched_wakeup(probe_wakeup, NULL); 674 unregister_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL); 675 } 676 677 static bool wakeup_busy; 678 679 static int __wakeup_tracer_init(struct trace_array *tr) 680 { 681 save_flags = tr->trace_flags; 682 683 /* non overwrite screws up the latency tracers */ 684 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1); 685 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1); 686 687 tr->max_latency = 0; 688 wakeup_trace = tr; 689 ftrace_init_array_ops(tr, wakeup_tracer_call); 690 start_wakeup_tracer(tr); 691 692 wakeup_busy = true; 693 return 0; 694 } 695 696 static int wakeup_tracer_init(struct trace_array *tr) 697 { 698 if (wakeup_busy) 699 return -EBUSY; 700 701 wakeup_dl = 0; 702 wakeup_rt = 0; 703 return __wakeup_tracer_init(tr); 704 } 705 706 static int wakeup_rt_tracer_init(struct trace_array *tr) 707 { 708 if (wakeup_busy) 709 return -EBUSY; 710 711 wakeup_dl = 0; 712 wakeup_rt = 1; 713 return __wakeup_tracer_init(tr); 714 } 715 716 static int wakeup_dl_tracer_init(struct trace_array *tr) 717 { 718 if (wakeup_busy) 719 return -EBUSY; 720 721 wakeup_dl = 1; 722 wakeup_rt = 0; 723 return __wakeup_tracer_init(tr); 724 } 725 726 static void wakeup_tracer_reset(struct trace_array *tr) 727 { 728 int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT; 729 int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE; 730 731 stop_wakeup_tracer(tr); 732 /* make sure we put back any tasks we are tracing */ 733 wakeup_reset(tr); 734 735 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag); 736 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag); 737 ftrace_reset_array_ops(tr); 738 wakeup_busy = false; 739 } 740 741 static void wakeup_tracer_start(struct trace_array *tr) 742 { 743 wakeup_reset(tr); 744 tracer_enabled = 1; 745 } 746 747 static void wakeup_tracer_stop(struct trace_array *tr) 748 { 749 tracer_enabled = 0; 750 } 751 752 static struct tracer wakeup_tracer __read_mostly = 753 { 754 .name = "wakeup", 755 .init = wakeup_tracer_init, 756 .reset = wakeup_tracer_reset, 757 .start = wakeup_tracer_start, 758 .stop = wakeup_tracer_stop, 759 .print_max = true, 760 .print_header = wakeup_print_header, 761 .print_line = wakeup_print_line, 762 .flag_changed = wakeup_flag_changed, 763 #ifdef CONFIG_FTRACE_SELFTEST 764 .selftest = trace_selftest_startup_wakeup, 765 #endif 766 .open = wakeup_trace_open, 767 .close = wakeup_trace_close, 768 .allow_instances = true, 769 .use_max_tr = true, 770 }; 771 772 static struct tracer wakeup_rt_tracer __read_mostly = 773 { 774 .name = "wakeup_rt", 775 .init = wakeup_rt_tracer_init, 776 .reset = wakeup_tracer_reset, 777 .start = wakeup_tracer_start, 778 .stop = wakeup_tracer_stop, 779 .print_max = true, 780 .print_header = wakeup_print_header, 781 .print_line = wakeup_print_line, 782 .flag_changed = wakeup_flag_changed, 783 #ifdef CONFIG_FTRACE_SELFTEST 784 .selftest = trace_selftest_startup_wakeup, 785 #endif 786 .open = wakeup_trace_open, 787 .close = wakeup_trace_close, 788 .allow_instances = true, 789 .use_max_tr = true, 790 }; 791 792 static struct tracer wakeup_dl_tracer __read_mostly = 793 { 794 .name = "wakeup_dl", 795 .init = wakeup_dl_tracer_init, 796 .reset = wakeup_tracer_reset, 797 .start = wakeup_tracer_start, 798 .stop = wakeup_tracer_stop, 799 .print_max = true, 800 .print_header = wakeup_print_header, 801 .print_line = wakeup_print_line, 802 .flag_changed = wakeup_flag_changed, 803 #ifdef CONFIG_FTRACE_SELFTEST 804 .selftest = trace_selftest_startup_wakeup, 805 #endif 806 .open = wakeup_trace_open, 807 .close = wakeup_trace_close, 808 .allow_instances = true, 809 .use_max_tr = true, 810 }; 811 812 __init static int init_wakeup_tracer(void) 813 { 814 int ret; 815 816 ret = register_tracer(&wakeup_tracer); 817 if (ret) 818 return ret; 819 820 ret = register_tracer(&wakeup_rt_tracer); 821 if (ret) 822 return ret; 823 824 ret = register_tracer(&wakeup_dl_tracer); 825 if (ret) 826 return ret; 827 828 return 0; 829 } 830 core_initcall(init_wakeup_tracer); 831