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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * trace irqs off critical timings
4 *
5 * Copyright (C) 2007-2008 Steven Rostedt <[email protected]>
6 * Copyright (C) 2008 Ingo Molnar <[email protected]>
7 *
8 * From code in the latency_tracer, that is:
9 *
10 * Copyright (C) 2004-2006 Ingo Molnar
11 * Copyright (C) 2004 Nadia Yvette Chambers
12 */
13#include <linux/kallsyms.h>
14#include <linux/uaccess.h>
15#include <linux/module.h>
16#include <linux/ftrace.h>
17#include <linux/kprobes.h>
18
19#include "trace.h"
20
21#include <trace/events/preemptirq.h>
22
23#if defined(CONFIG_IRQSOFF_TRACER) || defined(CONFIG_PREEMPT_TRACER)
24static struct trace_array *irqsoff_trace __read_mostly;
25static int tracer_enabled __read_mostly;
26
27static DEFINE_PER_CPU(int, tracing_cpu);
28
29static DEFINE_RAW_SPINLOCK(max_trace_lock);
30
31enum {
32 TRACER_IRQS_OFF = (1 << 1),
33 TRACER_PREEMPT_OFF = (1 << 2),
34};
35
36static int trace_type __read_mostly;
37
38static int save_flags;
39
40static void stop_irqsoff_tracer(struct trace_array *tr, int graph);
41static int start_irqsoff_tracer(struct trace_array *tr, int graph);
42
43#ifdef CONFIG_PREEMPT_TRACER
44static inline int
45preempt_trace(int pc)
46{
47 return ((trace_type & TRACER_PREEMPT_OFF) && pc);
48}
49#else
50# define preempt_trace(pc) (0)
51#endif
52
53#ifdef CONFIG_IRQSOFF_TRACER
54static inline int
55irq_trace(void)
56{
57 return ((trace_type & TRACER_IRQS_OFF) &&
58 irqs_disabled());
59}
60#else
61# define irq_trace() (0)
62#endif
63
64#ifdef CONFIG_FUNCTION_GRAPH_TRACER
65static int irqsoff_display_graph(struct trace_array *tr, int set);
66# define is_graph(tr) ((tr)->trace_flags & TRACE_ITER(DISPLAY_GRAPH))
67#else
68static inline int irqsoff_display_graph(struct trace_array *tr, int set)
69{
70 return -EINVAL;
71}
72# define is_graph(tr) false
73#endif
74
75/*
76 * Sequence count - we record it when starting a measurement and
77 * skip the latency if the sequence has changed - some other section
78 * did a maximum and could disturb our measurement with serial console
79 * printouts, etc. Truly coinciding maximum latencies should be rare
80 * and what happens together happens separately as well, so this doesn't
81 * decrease the validity of the maximum found:
82 */
83static __cacheline_aligned_in_smp unsigned long max_sequence;
84
85#ifdef CONFIG_FUNCTION_TRACER
86/*
87 * Prologue for the preempt and irqs off function tracers.
88 *
89 * Returns 1 if it is OK to continue, and data->disabled is
90 * incremented.
91 * 0 if the trace is to be ignored, and data->disabled
92 * is kept the same.
93 *
94 * Note, this function is also used outside this ifdef but
95 * inside the #ifdef of the function graph tracer below.
96 * This is OK, since the function graph tracer is
97 * dependent on the function tracer.
98 */
99static int func_prolog_dec(struct trace_array *tr,
100 struct trace_array_cpu **data,
101 unsigned long *flags)
102{
103 long disabled;
104 int cpu;
105
106 /*
107 * Does not matter if we preempt. We test the flags
108 * afterward, to see if irqs are disabled or not.
109 * If we preempt and get a false positive, the flags
110 * test will fail.
111 */
112 cpu = raw_smp_processor_id();
113 if (likely(!per_cpu(tracing_cpu, cpu)))
114 return 0;
115
116 local_save_flags(*flags);
117 /*
118 * Slight chance to get a false positive on tracing_cpu,
119 * although I'm starting to think there isn't a chance.
120 * Leave this for now just to be paranoid.
121 */
122 if (!irqs_disabled_flags(*flags) && !preempt_count())
123 return 0;
124
125 *data = per_cpu_ptr(tr->array_buffer.data, cpu);
126 disabled = local_inc_return(&(*data)->disabled);
127
128 if (likely(disabled == 1))
129 return 1;
130
131 local_dec(&(*data)->disabled);
132
133 return 0;
134}
135
136/*
137 * irqsoff uses its own tracer function to keep the overhead down:
138 */
139static void
140irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip,
141 struct ftrace_ops *op, struct ftrace_regs *fregs)
142{
143 struct trace_array *tr = irqsoff_trace;
144 struct trace_array_cpu *data;
145 unsigned long flags;
146 unsigned int trace_ctx;
147
148 if (!func_prolog_dec(tr, &data, &flags))
149 return;
150
151 trace_ctx = tracing_gen_ctx_flags(flags);
152
153 trace_function(tr, ip, parent_ip, trace_ctx, fregs);
154
155 local_dec(&data->disabled);
156}
157#endif /* CONFIG_FUNCTION_TRACER */
158
159#ifdef CONFIG_FUNCTION_GRAPH_TRACER
160static int irqsoff_display_graph(struct trace_array *tr, int set)
161{
162 int cpu;
163
164 if (!(is_graph(tr) ^ set))
165 return 0;
166
167 stop_irqsoff_tracer(irqsoff_trace, !set);
168
169 for_each_possible_cpu(cpu)
170 per_cpu(tracing_cpu, cpu) = 0;
171
172 tr->max_latency = 0;
173 tracing_reset_online_cpus(&irqsoff_trace->array_buffer);
174
175 return start_irqsoff_tracer(irqsoff_trace, set);
176}
177
178static int irqsoff_graph_entry(struct ftrace_graph_ent *trace,
179 struct fgraph_ops *gops,
180 struct ftrace_regs *fregs)
181{
182 struct trace_array *tr = irqsoff_trace;
183 struct trace_array_cpu *data;
184 unsigned long flags;
185 unsigned int trace_ctx;
186 u64 *calltime;
187 int ret = 0;
188
189 if (ftrace_graph_ignore_func(gops, trace))
190 return 0;
191 /*
192 * Do not trace a function if it's filtered by set_graph_notrace.
193 * Make the index of ret stack negative to indicate that it should
194 * ignore further functions. But it needs its own ret stack entry
195 * to recover the original index in order to continue tracing after
196 * returning from the function.
197 */
198 if (ftrace_graph_notrace_addr(trace->func))
199 return 1;
200
201 if (!func_prolog_dec(tr, &data, &flags))
202 return 0;
203
204 calltime = fgraph_reserve_data(gops->idx, sizeof(*calltime));
205 if (calltime) {
206 *calltime = trace_clock_local();
207 trace_ctx = tracing_gen_ctx_flags(flags);
208 ret = __trace_graph_entry(tr, trace, trace_ctx);
209 }
210 local_dec(&data->disabled);
211
212 return ret;
213}
214
215static void irqsoff_graph_return(struct ftrace_graph_ret *trace,
216 struct fgraph_ops *gops,
217 struct ftrace_regs *fregs)
218{
219 struct trace_array *tr = irqsoff_trace;
220 struct trace_array_cpu *data;
221 unsigned long flags;
222 unsigned int trace_ctx;
223 u64 *calltime;
224 u64 rettime;
225 int size;
226
227 ftrace_graph_addr_finish(gops, trace);
228
229 if (!func_prolog_dec(tr, &data, &flags))
230 return;
231
232 rettime = trace_clock_local();
233 calltime = fgraph_retrieve_data(gops->idx, &size);
234 if (calltime) {
235 trace_ctx = tracing_gen_ctx_flags(flags);
236 __trace_graph_return(tr, trace, trace_ctx, *calltime, rettime);
237 }
238 local_dec(&data->disabled);
239}
240
241static struct fgraph_ops fgraph_ops = {
242 .entryfunc = &irqsoff_graph_entry,
243 .retfunc = &irqsoff_graph_return,
244};
245
246static void irqsoff_trace_open(struct trace_iterator *iter)
247{
248 if (is_graph(iter->tr))
249 graph_trace_open(iter);
250}
251
252static void irqsoff_trace_close(struct trace_iterator *iter)
253{
254 if (iter->private)
255 graph_trace_close(iter);
256}
257
258#define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_CPU | \
259 TRACE_GRAPH_PRINT_PROC | \
260 TRACE_GRAPH_PRINT_REL_TIME | \
261 TRACE_GRAPH_PRINT_DURATION)
262
263static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
264{
265 /*
266 * In graph mode call the graph tracer output function,
267 * otherwise go with the TRACE_FN event handler
268 */
269 if (is_graph(iter->tr))
270 return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS);
271
272 return TRACE_TYPE_UNHANDLED;
273}
274
275static void irqsoff_print_header(struct seq_file *s)
276{
277 struct trace_array *tr = irqsoff_trace;
278
279 if (is_graph(tr))
280 print_graph_headers_flags(s, GRAPH_TRACER_FLAGS);
281 else
282 trace_default_header(s);
283}
284
285static void
286__trace_function(struct trace_array *tr,
287 unsigned long ip, unsigned long parent_ip,
288 unsigned int trace_ctx)
289{
290 if (is_graph(tr))
291 trace_graph_function(tr, ip, parent_ip, trace_ctx);
292 else
293 trace_function(tr, ip, parent_ip, trace_ctx, NULL);
294}
295
296#else
297static inline void
298__trace_function(struct trace_array *tr,
299 unsigned long ip, unsigned long parent_ip,
300 unsigned int trace_ctx)
301{
302 return trace_function(tr, ip, parent_ip, trace_ctx, NULL);
303}
304
305static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
306{
307 return TRACE_TYPE_UNHANDLED;
308}
309
310static void irqsoff_trace_open(struct trace_iterator *iter) { }
311static void irqsoff_trace_close(struct trace_iterator *iter) { }
312
313#ifdef CONFIG_FUNCTION_TRACER
314static void irqsoff_print_header(struct seq_file *s)
315{
316 trace_default_header(s);
317}
318#else
319static void irqsoff_print_header(struct seq_file *s)
320{
321 trace_latency_header(s);
322}
323#endif /* CONFIG_FUNCTION_TRACER */
324#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
325
326/*
327 * Should this new latency be reported/recorded?
328 */
329static bool report_latency(struct trace_array *tr, u64 delta)
330{
331 if (tracing_thresh) {
332 if (delta < tracing_thresh)
333 return false;
334 } else {
335 if (delta <= tr->max_latency)
336 return false;
337 }
338 return true;
339}
340
341static void
342check_critical_timing(struct trace_array *tr,
343 struct trace_array_cpu *data,
344 unsigned long parent_ip,
345 int cpu)
346{
347 u64 T0, T1, delta;
348 unsigned long flags;
349 unsigned int trace_ctx;
350
351 T0 = data->preempt_timestamp;
352 T1 = ftrace_now(cpu);
353 delta = T1-T0;
354
355 trace_ctx = tracing_gen_ctx();
356
357 if (!report_latency(tr, delta))
358 goto out;
359
360 raw_spin_lock_irqsave(&max_trace_lock, flags);
361
362 /* check if we are still the max latency */
363 if (!report_latency(tr, delta))
364 goto out_unlock;
365
366 __trace_function(tr, CALLER_ADDR0, parent_ip, trace_ctx);
367 /* Skip 5 functions to get to the irq/preempt enable function */
368 __trace_stack(tr, trace_ctx, 5);
369
370 if (data->critical_sequence != max_sequence)
371 goto out_unlock;
372
373 data->critical_end = parent_ip;
374
375 if (likely(!is_tracing_stopped())) {
376 tr->max_latency = delta;
377 update_max_tr_single(tr, current, cpu);
378 }
379
380 max_sequence++;
381
382out_unlock:
383 raw_spin_unlock_irqrestore(&max_trace_lock, flags);
384
385out:
386 data->critical_sequence = max_sequence;
387 data->preempt_timestamp = ftrace_now(cpu);
388 __trace_function(tr, CALLER_ADDR0, parent_ip, trace_ctx);
389}
390
391static nokprobe_inline void
392start_critical_timing(unsigned long ip, unsigned long parent_ip)
393{
394 int cpu;
395 struct trace_array *tr = irqsoff_trace;
396 struct trace_array_cpu *data;
397 long disabled;
398
399 if (!tracer_enabled || !tracing_is_enabled())
400 return;
401
402 cpu = raw_smp_processor_id();
403
404 if (per_cpu(tracing_cpu, cpu))
405 return;
406
407 data = per_cpu_ptr(tr->array_buffer.data, cpu);
408
409 if (unlikely(!data) || local_read(&data->disabled))
410 return;
411
412 disabled = local_inc_return(&data->disabled);
413
414 if (disabled == 1) {
415 data->critical_sequence = max_sequence;
416 data->preempt_timestamp = ftrace_now(cpu);
417 data->critical_start = parent_ip ? : ip;
418
419 __trace_function(tr, ip, parent_ip, tracing_gen_ctx());
420
421 per_cpu(tracing_cpu, cpu) = 1;
422 }
423
424 local_dec(&data->disabled);
425}
426
427static nokprobe_inline void
428stop_critical_timing(unsigned long ip, unsigned long parent_ip)
429{
430 int cpu;
431 struct trace_array *tr = irqsoff_trace;
432 struct trace_array_cpu *data;
433 unsigned int trace_ctx;
434 long disabled;
435
436 cpu = raw_smp_processor_id();
437 /* Always clear the tracing cpu on stopping the trace */
438 if (unlikely(per_cpu(tracing_cpu, cpu)))
439 per_cpu(tracing_cpu, cpu) = 0;
440 else
441 return;
442
443 if (!tracer_enabled || !tracing_is_enabled())
444 return;
445
446 data = per_cpu_ptr(tr->array_buffer.data, cpu);
447
448 if (unlikely(!data) ||
449 !data->critical_start || local_read(&data->disabled))
450 return;
451
452 disabled = local_inc_return(&data->disabled);
453
454 if (disabled == 1) {
455 trace_ctx = tracing_gen_ctx();
456 __trace_function(tr, ip, parent_ip, trace_ctx);
457 check_critical_timing(tr, data, parent_ip ? : ip, cpu);
458 data->critical_start = 0;
459 }
460
461 local_dec(&data->disabled);
462}
463
464/* start and stop critical timings used to for stoppage (in idle) */
465void start_critical_timings(void)
466{
467 if (preempt_trace(preempt_count()) || irq_trace())
468 start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
469}
470EXPORT_SYMBOL_GPL(start_critical_timings);
471NOKPROBE_SYMBOL(start_critical_timings);
472
473void stop_critical_timings(void)
474{
475 if (preempt_trace(preempt_count()) || irq_trace())
476 stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
477}
478EXPORT_SYMBOL_GPL(stop_critical_timings);
479NOKPROBE_SYMBOL(stop_critical_timings);
480
481#ifdef CONFIG_FUNCTION_TRACER
482static bool function_enabled;
483
484static int register_irqsoff_function(struct trace_array *tr, int graph, int set)
485{
486 int ret;
487
488 /* 'set' is set if TRACE_ITER(FUNCTION) is about to be set */
489 if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER(FUNCTION))))
490 return 0;
491
492 if (graph)
493 ret = register_ftrace_graph(&fgraph_ops);
494 else
495 ret = register_ftrace_function(tr->ops);
496
497 if (!ret)
498 function_enabled = true;
499
500 return ret;
501}
502
503static void unregister_irqsoff_function(struct trace_array *tr, int graph)
504{
505 if (!function_enabled)
506 return;
507
508 if (graph)
509 unregister_ftrace_graph(&fgraph_ops);
510 else
511 unregister_ftrace_function(tr->ops);
512
513 function_enabled = false;
514}
515
516static int irqsoff_function_set(struct trace_array *tr, u32 mask, int set)
517{
518 if (!(mask & TRACE_ITER(FUNCTION)))
519 return 0;
520
521 if (set)
522 register_irqsoff_function(tr, is_graph(tr), 1);
523 else
524 unregister_irqsoff_function(tr, is_graph(tr));
525 return 1;
526}
527#else
528static int register_irqsoff_function(struct trace_array *tr, int graph, int set)
529{
530 return 0;
531}
532static void unregister_irqsoff_function(struct trace_array *tr, int graph) { }
533static inline int irqsoff_function_set(struct trace_array *tr, u32 mask, int set)
534{
535 return 0;
536}
537#endif /* CONFIG_FUNCTION_TRACER */
538
539static int irqsoff_flag_changed(struct trace_array *tr, u64 mask, int set)
540{
541 struct tracer *tracer = tr->current_trace;
542
543 if (irqsoff_function_set(tr, mask, set))
544 return 0;
545
546#ifdef CONFIG_FUNCTION_GRAPH_TRACER
547 if (mask & TRACE_ITER(DISPLAY_GRAPH))
548 return irqsoff_display_graph(tr, set);
549#endif
550
551 return trace_keep_overwrite(tracer, mask, set);
552}
553
554static int start_irqsoff_tracer(struct trace_array *tr, int graph)
555{
556 int ret;
557
558 ret = register_irqsoff_function(tr, graph, 0);
559
560 if (!ret && tracing_is_enabled())
561 tracer_enabled = 1;
562 else
563 tracer_enabled = 0;
564
565 return ret;
566}
567
568static void stop_irqsoff_tracer(struct trace_array *tr, int graph)
569{
570 tracer_enabled = 0;
571
572 unregister_irqsoff_function(tr, graph);
573}
574
575static bool irqsoff_busy;
576
577static int __irqsoff_tracer_init(struct trace_array *tr)
578{
579 if (irqsoff_busy)
580 return -EBUSY;
581
582 save_flags = tr->trace_flags;
583
584 /* non overwrite screws up the latency tracers */
585 set_tracer_flag(tr, TRACE_ITER(OVERWRITE), 1);
586 set_tracer_flag(tr, TRACE_ITER(LATENCY_FMT), 1);
587 /* without pause, we will produce garbage if another latency occurs */
588 set_tracer_flag(tr, TRACE_ITER(PAUSE_ON_TRACE), 1);
589
590 tr->max_latency = 0;
591 irqsoff_trace = tr;
592 /* make sure that the tracer is visible */
593 smp_wmb();
594
595 ftrace_init_array_ops(tr, irqsoff_tracer_call);
596
597 /* Only toplevel instance supports graph tracing */
598 if (start_irqsoff_tracer(tr, (tr->flags & TRACE_ARRAY_FL_GLOBAL &&
599 is_graph(tr))))
600 printk(KERN_ERR "failed to start irqsoff tracer\n");
601
602 irqsoff_busy = true;
603 return 0;
604}
605
606static void __irqsoff_tracer_reset(struct trace_array *tr)
607{
608 int lat_flag = save_flags & TRACE_ITER(LATENCY_FMT);
609 int overwrite_flag = save_flags & TRACE_ITER(OVERWRITE);
610 int pause_flag = save_flags & TRACE_ITER(PAUSE_ON_TRACE);
611
612 stop_irqsoff_tracer(tr, is_graph(tr));
613
614 set_tracer_flag(tr, TRACE_ITER(LATENCY_FMT), lat_flag);
615 set_tracer_flag(tr, TRACE_ITER(OVERWRITE), overwrite_flag);
616 set_tracer_flag(tr, TRACE_ITER(PAUSE_ON_TRACE), pause_flag);
617 ftrace_reset_array_ops(tr);
618
619 irqsoff_busy = false;
620}
621
622static void irqsoff_tracer_start(struct trace_array *tr)
623{
624 tracer_enabled = 1;
625}
626
627static void irqsoff_tracer_stop(struct trace_array *tr)
628{
629 tracer_enabled = 0;
630}
631
632#ifdef CONFIG_IRQSOFF_TRACER
633/*
634 * We are only interested in hardirq on/off events:
635 */
636void tracer_hardirqs_on(unsigned long a0, unsigned long a1)
637{
638 if (!preempt_trace(preempt_count()) && irq_trace())
639 stop_critical_timing(a0, a1);
640}
641NOKPROBE_SYMBOL(tracer_hardirqs_on);
642
643void tracer_hardirqs_off(unsigned long a0, unsigned long a1)
644{
645 if (!preempt_trace(preempt_count()) && irq_trace())
646 start_critical_timing(a0, a1);
647}
648NOKPROBE_SYMBOL(tracer_hardirqs_off);
649
650static int irqsoff_tracer_init(struct trace_array *tr)
651{
652 trace_type = TRACER_IRQS_OFF;
653
654 return __irqsoff_tracer_init(tr);
655}
656
657static void irqsoff_tracer_reset(struct trace_array *tr)
658{
659 __irqsoff_tracer_reset(tr);
660}
661
662static struct tracer irqsoff_tracer __read_mostly =
663{
664 .name = "irqsoff",
665 .init = irqsoff_tracer_init,
666 .reset = irqsoff_tracer_reset,
667 .start = irqsoff_tracer_start,
668 .stop = irqsoff_tracer_stop,
669 .print_max = true,
670 .print_header = irqsoff_print_header,
671 .print_line = irqsoff_print_line,
672 .flag_changed = irqsoff_flag_changed,
673#ifdef CONFIG_FTRACE_SELFTEST
674 .selftest = trace_selftest_startup_irqsoff,
675#endif
676 .open = irqsoff_trace_open,
677 .close = irqsoff_trace_close,
678 .allow_instances = true,
679 .use_max_tr = true,
680};
681#endif /* CONFIG_IRQSOFF_TRACER */
682
683#ifdef CONFIG_PREEMPT_TRACER
684void tracer_preempt_on(unsigned long a0, unsigned long a1)
685{
686 if (preempt_trace(preempt_count()) && !irq_trace())
687 stop_critical_timing(a0, a1);
688}
689
690void tracer_preempt_off(unsigned long a0, unsigned long a1)
691{
692 if (preempt_trace(preempt_count()) && !irq_trace())
693 start_critical_timing(a0, a1);
694}
695
696static int preemptoff_tracer_init(struct trace_array *tr)
697{
698 trace_type = TRACER_PREEMPT_OFF;
699
700 return __irqsoff_tracer_init(tr);
701}
702
703static void preemptoff_tracer_reset(struct trace_array *tr)
704{
705 __irqsoff_tracer_reset(tr);
706}
707
708static struct tracer preemptoff_tracer __read_mostly =
709{
710 .name = "preemptoff",
711 .init = preemptoff_tracer_init,
712 .reset = preemptoff_tracer_reset,
713 .start = irqsoff_tracer_start,
714 .stop = irqsoff_tracer_stop,
715 .print_max = true,
716 .print_header = irqsoff_print_header,
717 .print_line = irqsoff_print_line,
718 .flag_changed = irqsoff_flag_changed,
719#ifdef CONFIG_FTRACE_SELFTEST
720 .selftest = trace_selftest_startup_preemptoff,
721#endif
722 .open = irqsoff_trace_open,
723 .close = irqsoff_trace_close,
724 .allow_instances = true,
725 .use_max_tr = true,
726};
727#endif /* CONFIG_PREEMPT_TRACER */
728
729#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
730
731static int preemptirqsoff_tracer_init(struct trace_array *tr)
732{
733 trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF;
734
735 return __irqsoff_tracer_init(tr);
736}
737
738static void preemptirqsoff_tracer_reset(struct trace_array *tr)
739{
740 __irqsoff_tracer_reset(tr);
741}
742
743static struct tracer preemptirqsoff_tracer __read_mostly =
744{
745 .name = "preemptirqsoff",
746 .init = preemptirqsoff_tracer_init,
747 .reset = preemptirqsoff_tracer_reset,
748 .start = irqsoff_tracer_start,
749 .stop = irqsoff_tracer_stop,
750 .print_max = true,
751 .print_header = irqsoff_print_header,
752 .print_line = irqsoff_print_line,
753 .flag_changed = irqsoff_flag_changed,
754#ifdef CONFIG_FTRACE_SELFTEST
755 .selftest = trace_selftest_startup_preemptirqsoff,
756#endif
757 .open = irqsoff_trace_open,
758 .close = irqsoff_trace_close,
759 .allow_instances = true,
760 .use_max_tr = true,
761};
762#endif
763
764__init static int init_irqsoff_tracer(void)
765{
766#ifdef CONFIG_IRQSOFF_TRACER
767 register_tracer(&irqsoff_tracer);
768#endif
769#ifdef CONFIG_PREEMPT_TRACER
770 register_tracer(&preemptoff_tracer);
771#endif
772#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
773 register_tracer(&preemptirqsoff_tracer);
774#endif
775
776 return 0;
777}
778core_initcall(init_irqsoff_tracer);
779#endif /* IRQSOFF_TRACER || PREEMPTOFF_TRACER */