kernel/trace/trace_irqsoff.c

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