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 bool wakeup_rt; 30 static bool wakeup_dl; 31 static bool tracing_dl; 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 unsigned int *trace_ctx) 71 { 72 long disabled; 73 int cpu; 74 75 if (likely(!wakeup_task)) 76 return 0; 77 78 *trace_ctx = tracing_gen_ctx(); 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 int trace_ctx; 120 int 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, &trace_ctx)) 135 return 0; 136 137 ret = __trace_graph_entry(tr, trace, trace_ctx); 138 atomic_dec(&data->disabled); 139 preempt_enable_notrace(); 140 141 return ret; 142 } 143 144 static void wakeup_graph_return(struct ftrace_graph_ret *trace) 145 { 146 struct trace_array *tr = wakeup_trace; 147 struct trace_array_cpu *data; 148 unsigned int trace_ctx; 149 150 ftrace_graph_addr_finish(trace); 151 152 if (!func_prolog_preempt_disable(tr, &data, &trace_ctx)) 153 return; 154 155 __trace_graph_return(tr, trace, trace_ctx); 156 atomic_dec(&data->disabled); 157 158 preempt_enable_notrace(); 159 return; 160 } 161 162 static struct fgraph_ops fgraph_wakeup_ops = { 163 .entryfunc = &wakeup_graph_entry, 164 .retfunc = &wakeup_graph_return, 165 }; 166 167 static void wakeup_trace_open(struct trace_iterator *iter) 168 { 169 if (is_graph(iter->tr)) 170 graph_trace_open(iter); 171 else 172 iter->private = NULL; 173 } 174 175 static void wakeup_trace_close(struct trace_iterator *iter) 176 { 177 if (iter->private) 178 graph_trace_close(iter); 179 } 180 181 #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_PROC | \ 182 TRACE_GRAPH_PRINT_CPU | \ 183 TRACE_GRAPH_PRINT_REL_TIME | \ 184 TRACE_GRAPH_PRINT_DURATION | \ 185 TRACE_GRAPH_PRINT_OVERHEAD | \ 186 TRACE_GRAPH_PRINT_IRQS) 187 188 static enum print_line_t wakeup_print_line(struct trace_iterator *iter) 189 { 190 /* 191 * In graph mode call the graph tracer output function, 192 * otherwise go with the TRACE_FN event handler 193 */ 194 if (is_graph(iter->tr)) 195 return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS); 196 197 return TRACE_TYPE_UNHANDLED; 198 } 199 200 static void wakeup_print_header(struct seq_file *s) 201 { 202 if (is_graph(wakeup_trace)) 203 print_graph_headers_flags(s, GRAPH_TRACER_FLAGS); 204 else 205 trace_default_header(s); 206 } 207 #endif /* else CONFIG_FUNCTION_GRAPH_TRACER */ 208 209 /* 210 * wakeup uses its own tracer function to keep the overhead down: 211 */ 212 static void 213 wakeup_tracer_call(unsigned long ip, unsigned long parent_ip, 214 struct ftrace_ops *op, struct ftrace_regs *fregs) 215 { 216 struct trace_array *tr = wakeup_trace; 217 struct trace_array_cpu *data; 218 unsigned long flags; 219 unsigned int trace_ctx; 220 221 if (!func_prolog_preempt_disable(tr, &data, &trace_ctx)) 222 return; 223 224 local_irq_save(flags); 225 trace_function(tr, ip, parent_ip, trace_ctx); 226 local_irq_restore(flags); 227 228 atomic_dec(&data->disabled); 229 preempt_enable_notrace(); 230 } 231 232 static int register_wakeup_function(struct trace_array *tr, int graph, int set) 233 { 234 int ret; 235 236 /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */ 237 if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION))) 238 return 0; 239 240 if (graph) 241 ret = register_ftrace_graph(&fgraph_wakeup_ops); 242 else 243 ret = register_ftrace_function(tr->ops); 244 245 if (!ret) 246 function_enabled = true; 247 248 return ret; 249 } 250 251 static void unregister_wakeup_function(struct trace_array *tr, int graph) 252 { 253 if (!function_enabled) 254 return; 255 256 if (graph) 257 unregister_ftrace_graph(&fgraph_wakeup_ops); 258 else 259 unregister_ftrace_function(tr->ops); 260 261 function_enabled = false; 262 } 263 264 static int wakeup_function_set(struct trace_array *tr, u32 mask, int set) 265 { 266 if (!(mask & TRACE_ITER_FUNCTION)) 267 return 0; 268 269 if (set) 270 register_wakeup_function(tr, is_graph(tr), 1); 271 else 272 unregister_wakeup_function(tr, is_graph(tr)); 273 return 1; 274 } 275 #else /* CONFIG_FUNCTION_TRACER */ 276 static int register_wakeup_function(struct trace_array *tr, int graph, int set) 277 { 278 return 0; 279 } 280 static void unregister_wakeup_function(struct trace_array *tr, int graph) { } 281 static int wakeup_function_set(struct trace_array *tr, u32 mask, int set) 282 { 283 return 0; 284 } 285 #endif /* else CONFIG_FUNCTION_TRACER */ 286 287 #ifndef CONFIG_FUNCTION_GRAPH_TRACER 288 static enum print_line_t wakeup_print_line(struct trace_iterator *iter) 289 { 290 return TRACE_TYPE_UNHANDLED; 291 } 292 293 static void wakeup_trace_open(struct trace_iterator *iter) { } 294 static void wakeup_trace_close(struct trace_iterator *iter) { } 295 296 static void wakeup_print_header(struct seq_file *s) 297 { 298 trace_default_header(s); 299 } 300 #endif /* !CONFIG_FUNCTION_GRAPH_TRACER */ 301 302 static void 303 __trace_function(struct trace_array *tr, 304 unsigned long ip, unsigned long parent_ip, 305 unsigned int trace_ctx) 306 { 307 if (is_graph(tr)) 308 trace_graph_function(tr, ip, parent_ip, trace_ctx); 309 else 310 trace_function(tr, ip, parent_ip, trace_ctx); 311 } 312 313 static int wakeup_flag_changed(struct trace_array *tr, u32 mask, int set) 314 { 315 struct tracer *tracer = tr->current_trace; 316 317 if (wakeup_function_set(tr, mask, set)) 318 return 0; 319 320 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 321 if (mask & TRACE_ITER_DISPLAY_GRAPH) 322 return wakeup_display_graph(tr, set); 323 #endif 324 325 return trace_keep_overwrite(tracer, mask, set); 326 } 327 328 static int start_func_tracer(struct trace_array *tr, int graph) 329 { 330 int ret; 331 332 ret = register_wakeup_function(tr, graph, 0); 333 334 if (!ret && tracing_is_enabled()) 335 tracer_enabled = 1; 336 else 337 tracer_enabled = 0; 338 339 return ret; 340 } 341 342 static void stop_func_tracer(struct trace_array *tr, int graph) 343 { 344 tracer_enabled = 0; 345 346 unregister_wakeup_function(tr, graph); 347 } 348 349 /* 350 * Should this new latency be reported/recorded? 351 */ 352 static bool report_latency(struct trace_array *tr, u64 delta) 353 { 354 if (tracing_thresh) { 355 if (delta < tracing_thresh) 356 return false; 357 } else { 358 if (delta <= tr->max_latency) 359 return false; 360 } 361 return true; 362 } 363 364 static void 365 probe_wakeup_migrate_task(void *ignore, struct task_struct *task, int cpu) 366 { 367 if (task != wakeup_task) 368 return; 369 370 wakeup_current_cpu = cpu; 371 } 372 373 static void 374 tracing_sched_switch_trace(struct trace_array *tr, 375 struct task_struct *prev, 376 struct task_struct *next, 377 unsigned int trace_ctx) 378 { 379 struct trace_event_call *call = &event_context_switch; 380 struct trace_buffer *buffer = tr->array_buffer.buffer; 381 struct ring_buffer_event *event; 382 struct ctx_switch_entry *entry; 383 384 event = trace_buffer_lock_reserve(buffer, TRACE_CTX, 385 sizeof(*entry), trace_ctx); 386 if (!event) 387 return; 388 entry = ring_buffer_event_data(event); 389 entry->prev_pid = prev->pid; 390 entry->prev_prio = prev->prio; 391 entry->prev_state = task_state_index(prev); 392 entry->next_pid = next->pid; 393 entry->next_prio = next->prio; 394 entry->next_state = task_state_index(next); 395 entry->next_cpu = task_cpu(next); 396 397 if (!call_filter_check_discard(call, entry, buffer, event)) 398 trace_buffer_unlock_commit(tr, buffer, event, trace_ctx); 399 } 400 401 static void 402 tracing_sched_wakeup_trace(struct trace_array *tr, 403 struct task_struct *wakee, 404 struct task_struct *curr, 405 unsigned int trace_ctx) 406 { 407 struct trace_event_call *call = &event_wakeup; 408 struct ring_buffer_event *event; 409 struct ctx_switch_entry *entry; 410 struct trace_buffer *buffer = tr->array_buffer.buffer; 411 412 event = trace_buffer_lock_reserve(buffer, TRACE_WAKE, 413 sizeof(*entry), trace_ctx); 414 if (!event) 415 return; 416 entry = ring_buffer_event_data(event); 417 entry->prev_pid = curr->pid; 418 entry->prev_prio = curr->prio; 419 entry->prev_state = task_state_index(curr); 420 entry->next_pid = wakee->pid; 421 entry->next_prio = wakee->prio; 422 entry->next_state = task_state_index(wakee); 423 entry->next_cpu = task_cpu(wakee); 424 425 if (!call_filter_check_discard(call, entry, buffer, event)) 426 trace_buffer_unlock_commit(tr, buffer, event, trace_ctx); 427 } 428 429 static void notrace 430 probe_wakeup_sched_switch(void *ignore, bool preempt, 431 struct task_struct *prev, struct task_struct *next, 432 unsigned int prev_state) 433 { 434 struct trace_array_cpu *data; 435 u64 T0, T1, delta; 436 unsigned long flags; 437 long disabled; 438 int cpu; 439 unsigned int trace_ctx; 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 /* disable local data, not wakeup_cpu data */ 459 cpu = raw_smp_processor_id(); 460 disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->array_buffer.data, cpu)->disabled); 461 if (likely(disabled != 1)) 462 goto out; 463 464 local_irq_save(flags); 465 trace_ctx = tracing_gen_ctx_flags(flags); 466 467 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, trace_ctx); 477 tracing_sched_switch_trace(wakeup_trace, prev, next, trace_ctx); 478 __trace_stack(wakeup_trace, trace_ctx, 0); 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 = false; 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 long disabled; 531 unsigned int trace_ctx; 532 533 if (likely(!tracer_enabled)) 534 return; 535 536 tracing_record_cmdline(p); 537 tracing_record_cmdline(current); 538 539 /* 540 * Semantic is like this: 541 * - wakeup tracer handles all tasks in the system, independently 542 * from their scheduling class; 543 * - wakeup_rt tracer handles tasks belonging to sched_dl and 544 * sched_rt class; 545 * - wakeup_dl handles tasks belonging to sched_dl class only. 546 */ 547 if (tracing_dl || (wakeup_dl && !dl_task(p)) || 548 (wakeup_rt && !dl_task(p) && !rt_task(p)) || 549 (!dl_task(p) && (p->prio >= wakeup_prio || p->prio >= current->prio))) 550 return; 551 552 disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->array_buffer.data, cpu)->disabled); 553 if (unlikely(disabled != 1)) 554 goto out; 555 556 trace_ctx = tracing_gen_ctx(); 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 = true; 579 else 580 tracing_dl = false; 581 582 wakeup_task = get_task_struct(p); 583 584 data = per_cpu_ptr(wakeup_trace->array_buffer.data, wakeup_cpu); 585 data->preempt_timestamp = ftrace_now(cpu); 586 tracing_sched_wakeup_trace(wakeup_trace, p, current, trace_ctx); 587 __trace_stack(wakeup_trace, trace_ctx, 0); 588 589 /* 590 * We must be careful in using CALLER_ADDR2. But since wake_up 591 * is not called by an assembly function (where as schedule is) 592 * it should be safe to use it here. 593 */ 594 __trace_function(wakeup_trace, CALLER_ADDR1, CALLER_ADDR2, trace_ctx); 595 596 out_locked: 597 arch_spin_unlock(&wakeup_lock); 598 out: 599 atomic_dec(&per_cpu_ptr(wakeup_trace->array_buffer.data, cpu)->disabled); 600 } 601 602 static void start_wakeup_tracer(struct trace_array *tr) 603 { 604 int ret; 605 606 ret = register_trace_sched_wakeup(probe_wakeup, NULL); 607 if (ret) { 608 pr_info("wakeup trace: Couldn't activate tracepoint" 609 " probe to kernel_sched_wakeup\n"); 610 return; 611 } 612 613 ret = register_trace_sched_wakeup_new(probe_wakeup, NULL); 614 if (ret) { 615 pr_info("wakeup trace: Couldn't activate tracepoint" 616 " probe to kernel_sched_wakeup_new\n"); 617 goto fail_deprobe; 618 } 619 620 ret = register_trace_sched_switch(probe_wakeup_sched_switch, NULL); 621 if (ret) { 622 pr_info("sched trace: Couldn't activate tracepoint" 623 " probe to kernel_sched_switch\n"); 624 goto fail_deprobe_wake_new; 625 } 626 627 ret = register_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL); 628 if (ret) { 629 pr_info("wakeup trace: Couldn't activate tracepoint" 630 " probe to kernel_sched_migrate_task\n"); 631 goto fail_deprobe_sched_switch; 632 } 633 634 wakeup_reset(tr); 635 636 /* 637 * Don't let the tracer_enabled = 1 show up before 638 * the wakeup_task is reset. This may be overkill since 639 * wakeup_reset does a spin_unlock after setting the 640 * wakeup_task to NULL, but I want to be safe. 641 * This is a slow path anyway. 642 */ 643 smp_wmb(); 644 645 if (start_func_tracer(tr, is_graph(tr))) 646 printk(KERN_ERR "failed to start wakeup tracer\n"); 647 648 return; 649 fail_deprobe_sched_switch: 650 unregister_trace_sched_switch(probe_wakeup_sched_switch, NULL); 651 fail_deprobe_wake_new: 652 unregister_trace_sched_wakeup_new(probe_wakeup, NULL); 653 fail_deprobe: 654 unregister_trace_sched_wakeup(probe_wakeup, NULL); 655 } 656 657 static void stop_wakeup_tracer(struct trace_array *tr) 658 { 659 tracer_enabled = 0; 660 stop_func_tracer(tr, is_graph(tr)); 661 unregister_trace_sched_switch(probe_wakeup_sched_switch, NULL); 662 unregister_trace_sched_wakeup_new(probe_wakeup, NULL); 663 unregister_trace_sched_wakeup(probe_wakeup, NULL); 664 unregister_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL); 665 } 666 667 static bool wakeup_busy; 668 669 static int __wakeup_tracer_init(struct trace_array *tr) 670 { 671 save_flags = tr->trace_flags; 672 673 /* non overwrite screws up the latency tracers */ 674 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1); 675 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1); 676 677 tr->max_latency = 0; 678 wakeup_trace = tr; 679 ftrace_init_array_ops(tr, wakeup_tracer_call); 680 start_wakeup_tracer(tr); 681 682 wakeup_busy = true; 683 return 0; 684 } 685 686 static int wakeup_tracer_init(struct trace_array *tr) 687 { 688 if (wakeup_busy) 689 return -EBUSY; 690 691 wakeup_dl = false; 692 wakeup_rt = false; 693 return __wakeup_tracer_init(tr); 694 } 695 696 static int wakeup_rt_tracer_init(struct trace_array *tr) 697 { 698 if (wakeup_busy) 699 return -EBUSY; 700 701 wakeup_dl = false; 702 wakeup_rt = true; 703 return __wakeup_tracer_init(tr); 704 } 705 706 static int wakeup_dl_tracer_init(struct trace_array *tr) 707 { 708 if (wakeup_busy) 709 return -EBUSY; 710 711 wakeup_dl = true; 712 wakeup_rt = false; 713 return __wakeup_tracer_init(tr); 714 } 715 716 static void wakeup_tracer_reset(struct trace_array *tr) 717 { 718 int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT; 719 int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE; 720 721 stop_wakeup_tracer(tr); 722 /* make sure we put back any tasks we are tracing */ 723 wakeup_reset(tr); 724 725 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag); 726 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag); 727 ftrace_reset_array_ops(tr); 728 wakeup_busy = false; 729 } 730 731 static void wakeup_tracer_start(struct trace_array *tr) 732 { 733 wakeup_reset(tr); 734 tracer_enabled = 1; 735 } 736 737 static void wakeup_tracer_stop(struct trace_array *tr) 738 { 739 tracer_enabled = 0; 740 } 741 742 static struct tracer wakeup_tracer __read_mostly = 743 { 744 .name = "wakeup", 745 .init = wakeup_tracer_init, 746 .reset = wakeup_tracer_reset, 747 .start = wakeup_tracer_start, 748 .stop = wakeup_tracer_stop, 749 .print_max = true, 750 .print_header = wakeup_print_header, 751 .print_line = wakeup_print_line, 752 .flag_changed = wakeup_flag_changed, 753 #ifdef CONFIG_FTRACE_SELFTEST 754 .selftest = trace_selftest_startup_wakeup, 755 #endif 756 .open = wakeup_trace_open, 757 .close = wakeup_trace_close, 758 .allow_instances = true, 759 .use_max_tr = true, 760 }; 761 762 static struct tracer wakeup_rt_tracer __read_mostly = 763 { 764 .name = "wakeup_rt", 765 .init = wakeup_rt_tracer_init, 766 .reset = wakeup_tracer_reset, 767 .start = wakeup_tracer_start, 768 .stop = wakeup_tracer_stop, 769 .print_max = true, 770 .print_header = wakeup_print_header, 771 .print_line = wakeup_print_line, 772 .flag_changed = wakeup_flag_changed, 773 #ifdef CONFIG_FTRACE_SELFTEST 774 .selftest = trace_selftest_startup_wakeup, 775 #endif 776 .open = wakeup_trace_open, 777 .close = wakeup_trace_close, 778 .allow_instances = true, 779 .use_max_tr = true, 780 }; 781 782 static struct tracer wakeup_dl_tracer __read_mostly = 783 { 784 .name = "wakeup_dl", 785 .init = wakeup_dl_tracer_init, 786 .reset = wakeup_tracer_reset, 787 .start = wakeup_tracer_start, 788 .stop = wakeup_tracer_stop, 789 .print_max = true, 790 .print_header = wakeup_print_header, 791 .print_line = wakeup_print_line, 792 .flag_changed = wakeup_flag_changed, 793 #ifdef CONFIG_FTRACE_SELFTEST 794 .selftest = trace_selftest_startup_wakeup, 795 #endif 796 .open = wakeup_trace_open, 797 .close = wakeup_trace_close, 798 .allow_instances = true, 799 .use_max_tr = true, 800 }; 801 802 __init static int init_wakeup_tracer(void) 803 { 804 int ret; 805 806 ret = register_tracer(&wakeup_tracer); 807 if (ret) 808 return ret; 809 810 ret = register_tracer(&wakeup_rt_tracer); 811 if (ret) 812 return ret; 813 814 ret = register_tracer(&wakeup_dl_tracer); 815 if (ret) 816 return ret; 817 818 return 0; 819 } 820 core_initcall(init_wakeup_tracer); 821