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