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 19 #include "trace.h" 20 21 #include <trace/events/preemptirq.h> 22 23 #if defined(CONFIG_IRQSOFF_TRACER) || defined(CONFIG_PREEMPT_TRACER) 24 static struct trace_array *irqsoff_trace __read_mostly; 25 static int tracer_enabled __read_mostly; 26 27 static DEFINE_PER_CPU(int, tracing_cpu); 28 29 static DEFINE_RAW_SPINLOCK(max_trace_lock); 30 31 enum { 32 TRACER_IRQS_OFF = (1 << 1), 33 TRACER_PREEMPT_OFF = (1 << 2), 34 }; 35 36 static int trace_type __read_mostly; 37 38 static int save_flags; 39 40 static void stop_irqsoff_tracer(struct trace_array *tr, int graph); 41 static int start_irqsoff_tracer(struct trace_array *tr, int graph); 42 43 #ifdef CONFIG_PREEMPT_TRACER 44 static inline int 45 preempt_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 54 static inline int 55 irq_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 65 static int irqsoff_display_graph(struct trace_array *tr, int set); 66 # define is_graph(tr) ((tr)->trace_flags & TRACE_ITER_DISPLAY_GRAPH) 67 #else 68 static 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 */ 83 static __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 */ 99 static 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 = atomic_inc_return(&(*data)->disabled); 127 128 if (likely(disabled == 1)) 129 return 1; 130 131 atomic_dec(&(*data)->disabled); 132 133 return 0; 134 } 135 136 /* 137 * irqsoff uses its own tracer function to keep the overhead down: 138 */ 139 static void 140 irqsoff_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); 154 155 atomic_dec(&data->disabled); 156 } 157 #endif /* CONFIG_FUNCTION_TRACER */ 158 159 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 160 static 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 } 177 178 static 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 int ret; 187 188 if (ftrace_graph_ignore_func(gops, trace)) 189 return 0; 190 /* 191 * Do not trace a function if it's filtered by set_graph_notrace. 192 * Make the index of ret stack negative to indicate that it should 193 * ignore further functions. But it needs its own ret stack entry 194 * to recover the original index in order to continue tracing after 195 * returning from the function. 196 */ 197 if (ftrace_graph_notrace_addr(trace->func)) 198 return 1; 199 200 if (!func_prolog_dec(tr, &data, &flags)) 201 return 0; 202 203 trace_ctx = tracing_gen_ctx_flags(flags); 204 ret = __trace_graph_entry(tr, trace, trace_ctx); 205 atomic_dec(&data->disabled); 206 207 return ret; 208 } 209 210 static void irqsoff_graph_return(struct ftrace_graph_ret *trace, 211 struct fgraph_ops *gops, 212 struct ftrace_regs *fregs) 213 { 214 struct trace_array *tr = irqsoff_trace; 215 struct trace_array_cpu *data; 216 unsigned long flags; 217 unsigned int trace_ctx; 218 219 ftrace_graph_addr_finish(gops, trace); 220 221 if (!func_prolog_dec(tr, &data, &flags)) 222 return; 223 224 trace_ctx = tracing_gen_ctx_flags(flags); 225 __trace_graph_return(tr, trace, trace_ctx); 226 atomic_dec(&data->disabled); 227 } 228 229 static struct fgraph_ops fgraph_ops = { 230 .entryfunc = &irqsoff_graph_entry, 231 .retfunc = &irqsoff_graph_return, 232 }; 233 234 static void irqsoff_trace_open(struct trace_iterator *iter) 235 { 236 if (is_graph(iter->tr)) 237 graph_trace_open(iter); 238 else 239 iter->private = NULL; 240 } 241 242 static void irqsoff_trace_close(struct trace_iterator *iter) 243 { 244 if (iter->private) 245 graph_trace_close(iter); 246 } 247 248 #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_CPU | \ 249 TRACE_GRAPH_PRINT_PROC | \ 250 TRACE_GRAPH_PRINT_REL_TIME | \ 251 TRACE_GRAPH_PRINT_DURATION) 252 253 static enum print_line_t irqsoff_print_line(struct trace_iterator *iter) 254 { 255 /* 256 * In graph mode call the graph tracer output function, 257 * otherwise go with the TRACE_FN event handler 258 */ 259 if (is_graph(iter->tr)) 260 return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS); 261 262 return TRACE_TYPE_UNHANDLED; 263 } 264 265 static void irqsoff_print_header(struct seq_file *s) 266 { 267 struct trace_array *tr = irqsoff_trace; 268 269 if (is_graph(tr)) 270 print_graph_headers_flags(s, GRAPH_TRACER_FLAGS); 271 else 272 trace_default_header(s); 273 } 274 275 static void 276 __trace_function(struct trace_array *tr, 277 unsigned long ip, unsigned long parent_ip, 278 unsigned int trace_ctx) 279 { 280 if (is_graph(tr)) 281 trace_graph_function(tr, ip, parent_ip, trace_ctx); 282 else 283 trace_function(tr, ip, parent_ip, trace_ctx); 284 } 285 286 #else 287 #define __trace_function trace_function 288 289 static enum print_line_t irqsoff_print_line(struct trace_iterator *iter) 290 { 291 return TRACE_TYPE_UNHANDLED; 292 } 293 294 static void irqsoff_trace_open(struct trace_iterator *iter) { } 295 static void irqsoff_trace_close(struct trace_iterator *iter) { } 296 297 #ifdef CONFIG_FUNCTION_TRACER 298 static void irqsoff_print_header(struct seq_file *s) 299 { 300 trace_default_header(s); 301 } 302 #else 303 static void irqsoff_print_header(struct seq_file *s) 304 { 305 trace_latency_header(s); 306 } 307 #endif /* CONFIG_FUNCTION_TRACER */ 308 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 309 310 /* 311 * Should this new latency be reported/recorded? 312 */ 313 static bool report_latency(struct trace_array *tr, u64 delta) 314 { 315 if (tracing_thresh) { 316 if (delta < tracing_thresh) 317 return false; 318 } else { 319 if (delta <= tr->max_latency) 320 return false; 321 } 322 return true; 323 } 324 325 static void 326 check_critical_timing(struct trace_array *tr, 327 struct trace_array_cpu *data, 328 unsigned long parent_ip, 329 int cpu) 330 { 331 u64 T0, T1, delta; 332 unsigned long flags; 333 unsigned int trace_ctx; 334 335 T0 = data->preempt_timestamp; 336 T1 = ftrace_now(cpu); 337 delta = T1-T0; 338 339 trace_ctx = tracing_gen_ctx(); 340 341 if (!report_latency(tr, delta)) 342 goto out; 343 344 raw_spin_lock_irqsave(&max_trace_lock, flags); 345 346 /* check if we are still the max latency */ 347 if (!report_latency(tr, delta)) 348 goto out_unlock; 349 350 __trace_function(tr, CALLER_ADDR0, parent_ip, trace_ctx); 351 /* Skip 5 functions to get to the irq/preempt enable function */ 352 __trace_stack(tr, trace_ctx, 5); 353 354 if (data->critical_sequence != max_sequence) 355 goto out_unlock; 356 357 data->critical_end = parent_ip; 358 359 if (likely(!is_tracing_stopped())) { 360 tr->max_latency = delta; 361 update_max_tr_single(tr, current, cpu); 362 } 363 364 max_sequence++; 365 366 out_unlock: 367 raw_spin_unlock_irqrestore(&max_trace_lock, flags); 368 369 out: 370 data->critical_sequence = max_sequence; 371 data->preempt_timestamp = ftrace_now(cpu); 372 __trace_function(tr, CALLER_ADDR0, parent_ip, trace_ctx); 373 } 374 375 static nokprobe_inline void 376 start_critical_timing(unsigned long ip, unsigned long parent_ip) 377 { 378 int cpu; 379 struct trace_array *tr = irqsoff_trace; 380 struct trace_array_cpu *data; 381 382 if (!tracer_enabled || !tracing_is_enabled()) 383 return; 384 385 cpu = raw_smp_processor_id(); 386 387 if (per_cpu(tracing_cpu, cpu)) 388 return; 389 390 data = per_cpu_ptr(tr->array_buffer.data, cpu); 391 392 if (unlikely(!data) || atomic_read(&data->disabled)) 393 return; 394 395 atomic_inc(&data->disabled); 396 397 data->critical_sequence = max_sequence; 398 data->preempt_timestamp = ftrace_now(cpu); 399 data->critical_start = parent_ip ? : ip; 400 401 __trace_function(tr, ip, parent_ip, tracing_gen_ctx()); 402 403 per_cpu(tracing_cpu, cpu) = 1; 404 405 atomic_dec(&data->disabled); 406 } 407 408 static nokprobe_inline void 409 stop_critical_timing(unsigned long ip, unsigned long parent_ip) 410 { 411 int cpu; 412 struct trace_array *tr = irqsoff_trace; 413 struct trace_array_cpu *data; 414 unsigned int trace_ctx; 415 416 cpu = raw_smp_processor_id(); 417 /* Always clear the tracing cpu on stopping the trace */ 418 if (unlikely(per_cpu(tracing_cpu, cpu))) 419 per_cpu(tracing_cpu, cpu) = 0; 420 else 421 return; 422 423 if (!tracer_enabled || !tracing_is_enabled()) 424 return; 425 426 data = per_cpu_ptr(tr->array_buffer.data, cpu); 427 428 if (unlikely(!data) || 429 !data->critical_start || atomic_read(&data->disabled)) 430 return; 431 432 atomic_inc(&data->disabled); 433 434 trace_ctx = tracing_gen_ctx(); 435 __trace_function(tr, ip, parent_ip, trace_ctx); 436 check_critical_timing(tr, data, parent_ip ? : ip, cpu); 437 data->critical_start = 0; 438 atomic_dec(&data->disabled); 439 } 440 441 /* start and stop critical timings used to for stoppage (in idle) */ 442 void start_critical_timings(void) 443 { 444 if (preempt_trace(preempt_count()) || irq_trace()) 445 start_critical_timing(CALLER_ADDR0, CALLER_ADDR1); 446 } 447 EXPORT_SYMBOL_GPL(start_critical_timings); 448 NOKPROBE_SYMBOL(start_critical_timings); 449 450 void stop_critical_timings(void) 451 { 452 if (preempt_trace(preempt_count()) || irq_trace()) 453 stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); 454 } 455 EXPORT_SYMBOL_GPL(stop_critical_timings); 456 NOKPROBE_SYMBOL(stop_critical_timings); 457 458 #ifdef CONFIG_FUNCTION_TRACER 459 static bool function_enabled; 460 461 static int register_irqsoff_function(struct trace_array *tr, int graph, int set) 462 { 463 int ret; 464 465 /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */ 466 if (function_enabled || (!set && !(tr->trace_flags & TRACE_ITER_FUNCTION))) 467 return 0; 468 469 if (graph) 470 ret = register_ftrace_graph(&fgraph_ops); 471 else 472 ret = register_ftrace_function(tr->ops); 473 474 if (!ret) 475 function_enabled = true; 476 477 return ret; 478 } 479 480 static void unregister_irqsoff_function(struct trace_array *tr, int graph) 481 { 482 if (!function_enabled) 483 return; 484 485 if (graph) 486 unregister_ftrace_graph(&fgraph_ops); 487 else 488 unregister_ftrace_function(tr->ops); 489 490 function_enabled = false; 491 } 492 493 static int irqsoff_function_set(struct trace_array *tr, u32 mask, int set) 494 { 495 if (!(mask & TRACE_ITER_FUNCTION)) 496 return 0; 497 498 if (set) 499 register_irqsoff_function(tr, is_graph(tr), 1); 500 else 501 unregister_irqsoff_function(tr, is_graph(tr)); 502 return 1; 503 } 504 #else 505 static int register_irqsoff_function(struct trace_array *tr, int graph, int set) 506 { 507 return 0; 508 } 509 static void unregister_irqsoff_function(struct trace_array *tr, int graph) { } 510 static inline int irqsoff_function_set(struct trace_array *tr, u32 mask, int set) 511 { 512 return 0; 513 } 514 #endif /* CONFIG_FUNCTION_TRACER */ 515 516 static int irqsoff_flag_changed(struct trace_array *tr, u32 mask, int set) 517 { 518 struct tracer *tracer = tr->current_trace; 519 520 if (irqsoff_function_set(tr, mask, set)) 521 return 0; 522 523 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 524 if (mask & TRACE_ITER_DISPLAY_GRAPH) 525 return irqsoff_display_graph(tr, set); 526 #endif 527 528 return trace_keep_overwrite(tracer, mask, set); 529 } 530 531 static int start_irqsoff_tracer(struct trace_array *tr, int graph) 532 { 533 int ret; 534 535 ret = register_irqsoff_function(tr, graph, 0); 536 537 if (!ret && tracing_is_enabled()) 538 tracer_enabled = 1; 539 else 540 tracer_enabled = 0; 541 542 return ret; 543 } 544 545 static void stop_irqsoff_tracer(struct trace_array *tr, int graph) 546 { 547 tracer_enabled = 0; 548 549 unregister_irqsoff_function(tr, graph); 550 } 551 552 static bool irqsoff_busy; 553 554 static int __irqsoff_tracer_init(struct trace_array *tr) 555 { 556 if (irqsoff_busy) 557 return -EBUSY; 558 559 save_flags = tr->trace_flags; 560 561 /* non overwrite screws up the latency tracers */ 562 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1); 563 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1); 564 /* without pause, we will produce garbage if another latency occurs */ 565 set_tracer_flag(tr, TRACE_ITER_PAUSE_ON_TRACE, 1); 566 567 tr->max_latency = 0; 568 irqsoff_trace = tr; 569 /* make sure that the tracer is visible */ 570 smp_wmb(); 571 572 ftrace_init_array_ops(tr, irqsoff_tracer_call); 573 574 /* Only toplevel instance supports graph tracing */ 575 if (start_irqsoff_tracer(tr, (tr->flags & TRACE_ARRAY_FL_GLOBAL && 576 is_graph(tr)))) 577 printk(KERN_ERR "failed to start irqsoff tracer\n"); 578 579 irqsoff_busy = true; 580 return 0; 581 } 582 583 static void __irqsoff_tracer_reset(struct trace_array *tr) 584 { 585 int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT; 586 int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE; 587 int pause_flag = save_flags & TRACE_ITER_PAUSE_ON_TRACE; 588 589 stop_irqsoff_tracer(tr, is_graph(tr)); 590 591 set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag); 592 set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag); 593 set_tracer_flag(tr, TRACE_ITER_PAUSE_ON_TRACE, pause_flag); 594 ftrace_reset_array_ops(tr); 595 596 irqsoff_busy = false; 597 } 598 599 static void irqsoff_tracer_start(struct trace_array *tr) 600 { 601 tracer_enabled = 1; 602 } 603 604 static void irqsoff_tracer_stop(struct trace_array *tr) 605 { 606 tracer_enabled = 0; 607 } 608 609 #ifdef CONFIG_IRQSOFF_TRACER 610 /* 611 * We are only interested in hardirq on/off events: 612 */ 613 void tracer_hardirqs_on(unsigned long a0, unsigned long a1) 614 { 615 if (!preempt_trace(preempt_count()) && irq_trace()) 616 stop_critical_timing(a0, a1); 617 } 618 NOKPROBE_SYMBOL(tracer_hardirqs_on); 619 620 void tracer_hardirqs_off(unsigned long a0, unsigned long a1) 621 { 622 if (!preempt_trace(preempt_count()) && irq_trace()) 623 start_critical_timing(a0, a1); 624 } 625 NOKPROBE_SYMBOL(tracer_hardirqs_off); 626 627 static int irqsoff_tracer_init(struct trace_array *tr) 628 { 629 trace_type = TRACER_IRQS_OFF; 630 631 return __irqsoff_tracer_init(tr); 632 } 633 634 static void irqsoff_tracer_reset(struct trace_array *tr) 635 { 636 __irqsoff_tracer_reset(tr); 637 } 638 639 static struct tracer irqsoff_tracer __read_mostly = 640 { 641 .name = "irqsoff", 642 .init = irqsoff_tracer_init, 643 .reset = irqsoff_tracer_reset, 644 .start = irqsoff_tracer_start, 645 .stop = irqsoff_tracer_stop, 646 .print_max = true, 647 .print_header = irqsoff_print_header, 648 .print_line = irqsoff_print_line, 649 .flag_changed = irqsoff_flag_changed, 650 #ifdef CONFIG_FTRACE_SELFTEST 651 .selftest = trace_selftest_startup_irqsoff, 652 #endif 653 .open = irqsoff_trace_open, 654 .close = irqsoff_trace_close, 655 .allow_instances = true, 656 .use_max_tr = true, 657 }; 658 #endif /* CONFIG_IRQSOFF_TRACER */ 659 660 #ifdef CONFIG_PREEMPT_TRACER 661 void tracer_preempt_on(unsigned long a0, unsigned long a1) 662 { 663 if (preempt_trace(preempt_count()) && !irq_trace()) 664 stop_critical_timing(a0, a1); 665 } 666 667 void tracer_preempt_off(unsigned long a0, unsigned long a1) 668 { 669 if (preempt_trace(preempt_count()) && !irq_trace()) 670 start_critical_timing(a0, a1); 671 } 672 673 static int preemptoff_tracer_init(struct trace_array *tr) 674 { 675 trace_type = TRACER_PREEMPT_OFF; 676 677 return __irqsoff_tracer_init(tr); 678 } 679 680 static void preemptoff_tracer_reset(struct trace_array *tr) 681 { 682 __irqsoff_tracer_reset(tr); 683 } 684 685 static struct tracer preemptoff_tracer __read_mostly = 686 { 687 .name = "preemptoff", 688 .init = preemptoff_tracer_init, 689 .reset = preemptoff_tracer_reset, 690 .start = irqsoff_tracer_start, 691 .stop = irqsoff_tracer_stop, 692 .print_max = true, 693 .print_header = irqsoff_print_header, 694 .print_line = irqsoff_print_line, 695 .flag_changed = irqsoff_flag_changed, 696 #ifdef CONFIG_FTRACE_SELFTEST 697 .selftest = trace_selftest_startup_preemptoff, 698 #endif 699 .open = irqsoff_trace_open, 700 .close = irqsoff_trace_close, 701 .allow_instances = true, 702 .use_max_tr = true, 703 }; 704 #endif /* CONFIG_PREEMPT_TRACER */ 705 706 #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER) 707 708 static int preemptirqsoff_tracer_init(struct trace_array *tr) 709 { 710 trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF; 711 712 return __irqsoff_tracer_init(tr); 713 } 714 715 static void preemptirqsoff_tracer_reset(struct trace_array *tr) 716 { 717 __irqsoff_tracer_reset(tr); 718 } 719 720 static struct tracer preemptirqsoff_tracer __read_mostly = 721 { 722 .name = "preemptirqsoff", 723 .init = preemptirqsoff_tracer_init, 724 .reset = preemptirqsoff_tracer_reset, 725 .start = irqsoff_tracer_start, 726 .stop = irqsoff_tracer_stop, 727 .print_max = true, 728 .print_header = irqsoff_print_header, 729 .print_line = irqsoff_print_line, 730 .flag_changed = irqsoff_flag_changed, 731 #ifdef CONFIG_FTRACE_SELFTEST 732 .selftest = trace_selftest_startup_preemptirqsoff, 733 #endif 734 .open = irqsoff_trace_open, 735 .close = irqsoff_trace_close, 736 .allow_instances = true, 737 .use_max_tr = true, 738 }; 739 #endif 740 741 __init static int init_irqsoff_tracer(void) 742 { 743 #ifdef CONFIG_IRQSOFF_TRACER 744 register_tracer(&irqsoff_tracer); 745 #endif 746 #ifdef CONFIG_PREEMPT_TRACER 747 register_tracer(&preemptoff_tracer); 748 #endif 749 #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER) 750 register_tracer(&preemptirqsoff_tracer); 751 #endif 752 753 return 0; 754 } 755 core_initcall(init_irqsoff_tracer); 756 #endif /* IRQSOFF_TRACER || PREEMPTOFF_TRACER */ 757