trace_irqsoff.c 18 KB

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