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 struct fgraph_ops *gops)
117 {
118 struct trace_array *tr = wakeup_trace;
119 struct trace_array_cpu *data;
120 unsigned int trace_ctx;
121 int ret = 0;
122
123 if (ftrace_graph_ignore_func(gops, trace))
124 return 0;
125 /*
126 * Do not trace a function if it's filtered by set_graph_notrace.
127 * Make the index of ret stack negative to indicate that it should
128 * ignore further functions. But it needs its own ret stack entry
129 * to recover the original index in order to continue tracing after
130 * returning from the function.
131 */
132 if (ftrace_graph_notrace_addr(trace->func))
133 return 1;
134
135 if (!func_prolog_preempt_disable(tr, &data, &trace_ctx))
136 return 0;
137
138 ret = __trace_graph_entry(tr, trace, trace_ctx);
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 struct fgraph_ops *gops)
147 {
148 struct trace_array *tr = wakeup_trace;
149 struct trace_array_cpu *data;
150 unsigned int trace_ctx;
151
152 ftrace_graph_addr_finish(gops, trace);
153
154 if (!func_prolog_preempt_disable(tr, &data, &trace_ctx))
155 return;
156
157 __trace_graph_return(tr, trace, trace_ctx);
158 atomic_dec(&data->disabled);
159
160 preempt_enable_notrace();
161 return;
162 }
163
164 static struct fgraph_ops fgraph_wakeup_ops = {
165 .entryfunc = &wakeup_graph_entry,
166 .retfunc = &wakeup_graph_return,
167 };
168
169 static void wakeup_trace_open(struct trace_iterator *iter)
170 {
171 if (is_graph(iter->tr))
172 graph_trace_open(iter);
173 else
174 iter->private = NULL;
175 }
176
177 static void wakeup_trace_close(struct trace_iterator *iter)
178 {
179 if (iter->private)
180 graph_trace_close(iter);
181 }
182
183 #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_PROC | \
184 TRACE_GRAPH_PRINT_CPU | \
185 TRACE_GRAPH_PRINT_REL_TIME | \
186 TRACE_GRAPH_PRINT_DURATION | \
187 TRACE_GRAPH_PRINT_OVERHEAD | \
188 TRACE_GRAPH_PRINT_IRQS)
189
190 static enum print_line_t wakeup_print_line(struct trace_iterator *iter)
191 {
192 /*
193 * In graph mode call the graph tracer output function,
194 * otherwise go with the TRACE_FN event handler
195 */
196 if (is_graph(iter->tr))
197 return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS);
198
199 return TRACE_TYPE_UNHANDLED;
200 }
201
202 static void wakeup_print_header(struct seq_file *s)
203 {
204 if (is_graph(wakeup_trace))
205 print_graph_headers_flags(s, GRAPH_TRACER_FLAGS);
206 else
207 trace_default_header(s);
208 }
209 #endif /* else CONFIG_FUNCTION_GRAPH_TRACER */
210
211 /*
212 * wakeup uses its own tracer function to keep the overhead down:
213 */
214 static void
215 wakeup_tracer_call(unsigned long ip, unsigned long parent_ip,
216 struct ftrace_ops *op, struct ftrace_regs *fregs)
217 {
218 struct trace_array *tr = wakeup_trace;
219 struct trace_array_cpu *data;
220 unsigned long flags;
221 unsigned int trace_ctx;
222
223 if (!func_prolog_preempt_disable(tr, &data, &trace_ctx))
224 return;
225
226 local_irq_save(flags);
227 trace_function(tr, ip, parent_ip, trace_ctx);
228 local_irq_restore(flags);
229
230 atomic_dec(&data->disabled);
231 preempt_enable_notrace();
232 }
233
234 static int register_wakeup_function(struct trace_array *tr, int graph, int set)
235 {
236 int ret;
237
238 /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */
239 if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION)))
240 return 0;
241
242 if (graph)
243 ret = register_ftrace_graph(&fgraph_wakeup_ops);
244 else
245 ret = register_ftrace_function(tr->ops);
246
247 if (!ret)
248 function_enabled = true;
249
250 return ret;
251 }
252
253 static void unregister_wakeup_function(struct trace_array *tr, int graph)
254 {
255 if (!function_enabled)
256 return;
257
258 if (graph)
259 unregister_ftrace_graph(&fgraph_wakeup_ops);
260 else
261 unregister_ftrace_function(tr->ops);
262
263 function_enabled = false;
264 }
265
266 static int wakeup_function_set(struct trace_array *tr, u32 mask, int set)
267 {
268 if (!(mask & TRACE_ITER_FUNCTION))
269 return 0;
270
271 if (set)
272 register_wakeup_function(tr, is_graph(tr), 1);
273 else
274 unregister_wakeup_function(tr, is_graph(tr));
275 return 1;
276 }
277 #else /* CONFIG_FUNCTION_TRACER */
278 static int register_wakeup_function(struct trace_array *tr, int graph, int set)
279 {
280 return 0;
281 }
282 static void unregister_wakeup_function(struct trace_array *tr, int graph) { }
283 static int wakeup_function_set(struct trace_array *tr, u32 mask, int set)
284 {
285 return 0;
286 }
287 #endif /* else CONFIG_FUNCTION_TRACER */
288
289 #ifndef CONFIG_FUNCTION_GRAPH_TRACER
290 static enum print_line_t wakeup_print_line(struct trace_iterator *iter)
291 {
292 return TRACE_TYPE_UNHANDLED;
293 }
294
295 static void wakeup_trace_open(struct trace_iterator *iter) { }
296 static void wakeup_trace_close(struct trace_iterator *iter) { }
297
298 static void wakeup_print_header(struct seq_file *s)
299 {
300 trace_default_header(s);
301 }
302 #endif /* !CONFIG_FUNCTION_GRAPH_TRACER */
303
304 static void
305 __trace_function(struct trace_array *tr,
306 unsigned long ip, unsigned long parent_ip,
307 unsigned int trace_ctx)
308 {
309 if (is_graph(tr))
310 trace_graph_function(tr, ip, parent_ip, trace_ctx);
311 else
312 trace_function(tr, ip, parent_ip, trace_ctx);
313 }
314
315 static int wakeup_flag_changed(struct trace_array *tr, u32 mask, int set)
316 {
317 struct tracer *tracer = tr->current_trace;
318
319 if (wakeup_function_set(tr, mask, set))
320 return 0;
321
322 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
323 if (mask & TRACE_ITER_DISPLAY_GRAPH)
324 return wakeup_display_graph(tr, set);
325 #endif
326
327 return trace_keep_overwrite(tracer, mask, set);
328 }
329
330 static int start_func_tracer(struct trace_array *tr, int graph)
331 {
332 int ret;
333
334 ret = register_wakeup_function(tr, graph, 0);
335
336 if (!ret && tracing_is_enabled())
337 tracer_enabled = 1;
338 else
339 tracer_enabled = 0;
340
341 return ret;
342 }
343
344 static void stop_func_tracer(struct trace_array *tr, int graph)
345 {
346 tracer_enabled = 0;
347
348 unregister_wakeup_function(tr, graph);
349 }
350
351 /*
352 * Should this new latency be reported/recorded?
353 */
354 static bool report_latency(struct trace_array *tr, u64 delta)
355 {
356 if (tracing_thresh) {
357 if (delta < tracing_thresh)
358 return false;
359 } else {
360 if (delta <= tr->max_latency)
361 return false;
362 }
363 return true;
364 }
365
366 static void
367 probe_wakeup_migrate_task(void *ignore, struct task_struct *task, int cpu)
368 {
369 if (task != wakeup_task)
370 return;
371
372 wakeup_current_cpu = cpu;
373 }
374
375 static void
376 tracing_sched_switch_trace(struct trace_array *tr,
377 struct task_struct *prev,
378 struct task_struct *next,
379 unsigned int trace_ctx)
380 {
381 struct trace_event_call *call = &event_context_switch;
382 struct trace_buffer *buffer = tr->array_buffer.buffer;
383 struct ring_buffer_event *event;
384 struct ctx_switch_entry *entry;
385
386 event = trace_buffer_lock_reserve(buffer, TRACE_CTX,
387 sizeof(*entry), trace_ctx);
388 if (!event)
389 return;
390 entry = ring_buffer_event_data(event);
391 entry->prev_pid = prev->pid;
392 entry->prev_prio = prev->prio;
393 entry->prev_state = task_state_index(prev);
394 entry->next_pid = next->pid;
395 entry->next_prio = next->prio;
396 entry->next_state = task_state_index(next);
397 entry->next_cpu = task_cpu(next);
398
399 if (!call_filter_check_discard(call, entry, buffer, event))
400 trace_buffer_unlock_commit(tr, buffer, event, trace_ctx);
401 }
402
403 static void
404 tracing_sched_wakeup_trace(struct trace_array *tr,
405 struct task_struct *wakee,
406 struct task_struct *curr,
407 unsigned int trace_ctx)
408 {
409 struct trace_event_call *call = &event_wakeup;
410 struct ring_buffer_event *event;
411 struct ctx_switch_entry *entry;
412 struct trace_buffer *buffer = tr->array_buffer.buffer;
413
414 event = trace_buffer_lock_reserve(buffer, TRACE_WAKE,
415 sizeof(*entry), trace_ctx);
416 if (!event)
417 return;
418 entry = ring_buffer_event_data(event);
419 entry->prev_pid = curr->pid;
420 entry->prev_prio = curr->prio;
421 entry->prev_state = task_state_index(curr);
422 entry->next_pid = wakee->pid;
423 entry->next_prio = wakee->prio;
424 entry->next_state = task_state_index(wakee);
425 entry->next_cpu = task_cpu(wakee);
426
427 if (!call_filter_check_discard(call, entry, buffer, event))
428 trace_buffer_unlock_commit(tr, buffer, event, trace_ctx);
429 }
430
431 static void notrace
432 probe_wakeup_sched_switch(void *ignore, bool preempt,
433 struct task_struct *prev, struct task_struct *next,
434 unsigned int prev_state)
435 {
436 struct trace_array_cpu *data;
437 u64 T0, T1, delta;
438 unsigned long flags;
439 long disabled;
440 int cpu;
441 unsigned int trace_ctx;
442
443 tracing_record_cmdline(prev);
444
445 if (unlikely(!tracer_enabled))
446 return;
447
448 /*
449 * When we start a new trace, we set wakeup_task to NULL
450 * and then set tracer_enabled = 1. We want to make sure
451 * that another CPU does not see the tracer_enabled = 1
452 * and the wakeup_task with an older task, that might
453 * actually be the same as next.
454 */
455 smp_rmb();
456
457 if (next != wakeup_task)
458 return;
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 trace_ctx = tracing_gen_ctx_flags(flags);
468
469 arch_spin_lock(&wakeup_lock);
470
471 /* We could race with grabbing wakeup_lock */
472 if (unlikely(!tracer_enabled || next != wakeup_task))
473 goto out_unlock;
474
475 /* The task we are waiting for is waking up */
476 data = per_cpu_ptr(wakeup_trace->array_buffer.data, wakeup_cpu);
477
478 __trace_function(wakeup_trace, CALLER_ADDR0, CALLER_ADDR1, trace_ctx);
479 tracing_sched_switch_trace(wakeup_trace, prev, next, trace_ctx);
480 __trace_stack(wakeup_trace, trace_ctx, 0);
481
482 T0 = data->preempt_timestamp;
483 T1 = ftrace_now(cpu);
484 delta = T1-T0;
485
486 if (!report_latency(wakeup_trace, delta))
487 goto out_unlock;
488
489 if (likely(!is_tracing_stopped())) {
490 wakeup_trace->max_latency = delta;
491 update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu, NULL);
492 }
493
494 out_unlock:
495 __wakeup_reset(wakeup_trace);
496 arch_spin_unlock(&wakeup_lock);
497 local_irq_restore(flags);
498 out:
499 atomic_dec(&per_cpu_ptr(wakeup_trace->array_buffer.data, cpu)->disabled);
500 }
501
502 static void __wakeup_reset(struct trace_array *tr)
503 {
504 wakeup_cpu = -1;
505 wakeup_prio = -1;
506 tracing_dl = false;
507
508 if (wakeup_task)
509 put_task_struct(wakeup_task);
510
511 wakeup_task = NULL;
512 }
513
514 static void wakeup_reset(struct trace_array *tr)
515 {
516 unsigned long flags;
517
518 tracing_reset_online_cpus(&tr->array_buffer);
519
520 local_irq_save(flags);
521 arch_spin_lock(&wakeup_lock);
522 __wakeup_reset(tr);
523 arch_spin_unlock(&wakeup_lock);
524 local_irq_restore(flags);
525 }
526
527 static void
528 probe_wakeup(void *ignore, struct task_struct *p)
529 {
530 struct trace_array_cpu *data;
531 int cpu = smp_processor_id();
532 long disabled;
533 unsigned int trace_ctx;
534
535 if (likely(!tracer_enabled))
536 return;
537
538 tracing_record_cmdline(p);
539 tracing_record_cmdline(current);
540
541 /*
542 * Semantic is like this:
543 * - wakeup tracer handles all tasks in the system, independently
544 * from their scheduling class;
545 * - wakeup_rt tracer handles tasks belonging to sched_dl and
546 * sched_rt class;
547 * - wakeup_dl handles tasks belonging to sched_dl class only.
548 */
549 if (tracing_dl || (wakeup_dl && !dl_task(p)) ||
550 (wakeup_rt && !dl_task(p) && !rt_task(p)) ||
551 (!dl_task(p) && (p->prio >= wakeup_prio || p->prio >= current->prio)))
552 return;
553
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 trace_ctx = tracing_gen_ctx();
559
560 /* interrupts should be off from try_to_wake_up */
561 arch_spin_lock(&wakeup_lock);
562
563 /* check for races. */
564 if (!tracer_enabled || tracing_dl ||
565 (!dl_task(p) && p->prio >= wakeup_prio))
566 goto out_locked;
567
568 /* reset the trace */
569 __wakeup_reset(wakeup_trace);
570
571 wakeup_cpu = task_cpu(p);
572 wakeup_current_cpu = wakeup_cpu;
573 wakeup_prio = p->prio;
574
575 /*
576 * Once you start tracing a -deadline task, don't bother tracing
577 * another task until the first one wakes up.
578 */
579 if (dl_task(p))
580 tracing_dl = true;
581 else
582 tracing_dl = false;
583
584 wakeup_task = get_task_struct(p);
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, trace_ctx);
589 __trace_stack(wakeup_trace, trace_ctx, 0);
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, trace_ctx);
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 = false;
694 wakeup_rt = false;
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 = false;
704 wakeup_rt = true;
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 = true;
714 wakeup_rt = false;
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
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