kernel/trace/trace_sched_wakeup.c

   1 /*
   2  * trace task wakeup timings
   3  *
   4  * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
   5  * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
   6  *
   7  * Based on code from the latency_tracer, that is:
   8  *
   9  *  Copyright (C) 2004-2006 Ingo Molnar
  10  *  Copyright (C) 2004 Nadia Yvette Chambers
  11  */
  12 #include <linux/module.h>
  13 #include <linux/fs.h>
  14 #include <linux/debugfs.h>
  15 #include <linux/kallsyms.h>
  16 #include <linux/uaccess.h>
  17 #include <linux/ftrace.h>
  18 #include <linux/sched/rt.h>
  19 #include <linux/sched/deadline.h>
  20 #include <trace/events/sched.h>
  21 #include "trace.h"
  22
  23 static struct trace_array       *wakeup_trace;
  24 static int __read_mostly        tracer_enabled;
  25
  26 static struct task_struct       *wakeup_task;
  27 static int                      wakeup_cpu;
  28 static int                      wakeup_current_cpu;
  29 static unsigned                 wakeup_prio = -1;
  30 static int                      wakeup_rt;
  31 static int                      wakeup_dl;
  32 static int                      tracing_dl = 0;
  33
  34 static arch_spinlock_t wakeup_lock =
  35         (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
  36
  37 static void wakeup_reset(struct trace_array *tr);
  38 static void __wakeup_reset(struct trace_array *tr);
  39 static int wakeup_graph_entry(struct ftrace_graph_ent *trace);
  40 static void wakeup_graph_return(struct ftrace_graph_ret *trace);
  41
  42 static int save_flags;
  43 static bool function_enabled;
  44
  45 #define TRACE_DISPLAY_GRAPH     1
  46
  47 static struct tracer_opt trace_opts[] = {
  48 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
  49         /* display latency trace as call graph */
  50         { TRACER_OPT(display-graph, TRACE_DISPLAY_GRAPH) },
  51 #endif
  52         { } /* Empty entry */
  53 };
  54
  55 static struct tracer_flags tracer_flags = {
  56         .val  = 0,
  57         .opts = trace_opts,
  58 };
  59
  60 #define is_graph() (tracer_flags.val & TRACE_DISPLAY_GRAPH)
  61
  62 #ifdef CONFIG_FUNCTION_TRACER
  63
  64 /*
  65  * Prologue for the wakeup function tracers.
  66  *
  67  * Returns 1 if it is OK to continue, and preemption
  68  *            is disabled and data->disabled is incremented.
  69  *         0 if the trace is to be ignored, and preemption
  70  *            is not disabled and data->disabled is
  71  *            kept the same.
  72  *
  73  * Note, this function is also used outside this ifdef but
  74  *  inside the #ifdef of the function graph tracer below.
  75  *  This is OK, since the function graph tracer is
  76  *  dependent on the function tracer.
  77  */
  78 static int
  79 func_prolog_preempt_disable(struct trace_array *tr,
  80                             struct trace_array_cpu **data,
  81                             int *pc)
  82 {
  83         long disabled;
  84         int cpu;
  85
  86         if (likely(!wakeup_task))
  87                 return 0;
  88
  89         *pc = preempt_count();
  90         preempt_disable_notrace();
  91
  92         cpu = raw_smp_processor_id();
  93         if (cpu != wakeup_current_cpu)
  94                 goto out_enable;
  95
  96         *data = per_cpu_ptr(tr->trace_buffer.data, cpu);
  97         disabled = atomic_inc_return(&(*data)->disabled);
  98         if (unlikely(disabled != 1))
  99                 goto out;
 100
 101         return 1;
 102
 103 out:
 104         atomic_dec(&(*data)->disabled);
 105
 106 out_enable:
 107         preempt_enable_notrace();
 108         return 0;
 109 }
 110
 111 /*
 112  * wakeup uses its own tracer function to keep the overhead down:
 113  */
 114 static void
 115 wakeup_tracer_call(unsigned long ip, unsigned long parent_ip,
 116                    struct ftrace_ops *op, struct pt_regs *pt_regs)
 117 {
 118         struct trace_array *tr = wakeup_trace;
 119         struct trace_array_cpu *data;
 120         unsigned long flags;
 121         int pc;
 122
 123         if (!func_prolog_preempt_disable(tr, &data, &pc))
 124                 return;
 125
 126         local_irq_save(flags);
 127         trace_function(tr, ip, parent_ip, flags, pc);
 128         local_irq_restore(flags);
 129
 130         atomic_dec(&data->disabled);
 131         preempt_enable_notrace();
 132 }
 133 #endif /* CONFIG_FUNCTION_TRACER */
 134
 135 static int register_wakeup_function(struct trace_array *tr, int graph, int set)
 136 {
 137         int ret;
 138
 139         /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */
 140         if (function_enabled || (!set && !(trace_flags & TRACE_ITER_FUNCTION)))
 141                 return 0;
 142
 143         if (graph)
 144                 ret = register_ftrace_graph(&wakeup_graph_return,
 145                                             &wakeup_graph_entry);
 146         else
 147                 ret = register_ftrace_function(tr->ops);
 148
 149         if (!ret)
 150                 function_enabled = true;
 151
 152         return ret;
 153 }
 154
 155 static void unregister_wakeup_function(struct trace_array *tr, int graph)
 156 {
 157         if (!function_enabled)
 158                 return;
 159
 160         if (graph)
 161                 unregister_ftrace_graph();
 162         else
 163                 unregister_ftrace_function(tr->ops);
 164
 165         function_enabled = false;
 166 }
 167
 168 static void wakeup_function_set(struct trace_array *tr, int set)
 169 {
 170         if (set)
 171                 register_wakeup_function(tr, is_graph(), 1);
 172         else
 173                 unregister_wakeup_function(tr, is_graph());
 174 }
 175
 176 static int wakeup_flag_changed(struct trace_array *tr, u32 mask, int set)
 177 {
 178         struct tracer *tracer = tr->current_trace;
 179
 180         if (mask & TRACE_ITER_FUNCTION)
 181                 wakeup_function_set(tr, set);
 182
 183         return trace_keep_overwrite(tracer, mask, set);
 184 }
 185
 186 static int start_func_tracer(struct trace_array *tr, int graph)
 187 {
 188         int ret;
 189
 190         ret = register_wakeup_function(tr, graph, 0);
 191
 192         if (!ret && tracing_is_enabled())
 193                 tracer_enabled = 1;
 194         else
 195                 tracer_enabled = 0;
 196
 197         return ret;
 198 }
 199
 200 static void stop_func_tracer(struct trace_array *tr, int graph)
 201 {
 202         tracer_enabled = 0;
 203
 204         unregister_wakeup_function(tr, graph);
 205 }
 206
 207 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 208 static int
 209 wakeup_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
 210 {
 211
 212         if (!(bit & TRACE_DISPLAY_GRAPH))
 213                 return -EINVAL;
 214
 215         if (!(is_graph() ^ set))
 216                 return 0;
 217
 218         stop_func_tracer(tr, !set);
 219
 220         wakeup_reset(wakeup_trace);
 221         tr->max_latency = 0;
 222
 223         return start_func_tracer(tr, set);
 224 }
 225
 226 static int wakeup_graph_entry(struct ftrace_graph_ent *trace)
 227 {
 228         struct trace_array *tr = wakeup_trace;
 229         struct trace_array_cpu *data;
 230         unsigned long flags;
 231         int pc, ret = 0;
 232
 233         if (!func_prolog_preempt_disable(tr, &data, &pc))
 234                 return 0;
 235
 236         local_save_flags(flags);
 237         ret = __trace_graph_entry(tr, trace, flags, pc);
 238         atomic_dec(&data->disabled);
 239         preempt_enable_notrace();
 240
 241         return ret;
 242 }
 243
 244 static void wakeup_graph_return(struct ftrace_graph_ret *trace)
 245 {
 246         struct trace_array *tr = wakeup_trace;
 247         struct trace_array_cpu *data;
 248         unsigned long flags;
 249         int pc;
 250
 251         if (!func_prolog_preempt_disable(tr, &data, &pc))
 252                 return;
 253
 254         local_save_flags(flags);
 255         __trace_graph_return(tr, trace, flags, pc);
 256         atomic_dec(&data->disabled);
 257
 258         preempt_enable_notrace();
 259         return;
 260 }
 261
 262 static void wakeup_trace_open(struct trace_iterator *iter)
 263 {
 264         if (is_graph())
 265                 graph_trace_open(iter);
 266 }
 267
 268 static void wakeup_trace_close(struct trace_iterator *iter)
 269 {
 270         if (iter->private)
 271                 graph_trace_close(iter);
 272 }
 273
 274 #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_PROC | \
 275                             TRACE_GRAPH_PRINT_ABS_TIME | \
 276                             TRACE_GRAPH_PRINT_DURATION)
 277
 278 static enum print_line_t wakeup_print_line(struct trace_iterator *iter)
 279 {
 280         /*
 281          * In graph mode call the graph tracer output function,
 282          * otherwise go with the TRACE_FN event handler
 283          */
 284         if (is_graph())
 285                 return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS);
 286
 287         return TRACE_TYPE_UNHANDLED;
 288 }
 289
 290 static void wakeup_print_header(struct seq_file *s)
 291 {
 292         if (is_graph())
 293                 print_graph_headers_flags(s, GRAPH_TRACER_FLAGS);
 294         else
 295                 trace_default_header(s);
 296 }
 297
 298 static void
 299 __trace_function(struct trace_array *tr,
 300                  unsigned long ip, unsigned long parent_ip,
 301                  unsigned long flags, int pc)
 302 {
 303         if (is_graph())
 304                 trace_graph_function(tr, ip, parent_ip, flags, pc);
 305         else
 306                 trace_function(tr, ip, parent_ip, flags, pc);
 307 }
 308 #else
 309 #define __trace_function trace_function
 310
 311 static int
 312 wakeup_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
 313 {
 314         return -EINVAL;
 315 }
 316
 317 static int wakeup_graph_entry(struct ftrace_graph_ent *trace)
 318 {
 319         return -1;
 320 }
 321
 322 static enum print_line_t wakeup_print_line(struct trace_iterator *iter)
 323 {
 324         return TRACE_TYPE_UNHANDLED;
 325 }
 326
 327 static void wakeup_graph_return(struct ftrace_graph_ret *trace) { }
 328 static void wakeup_trace_open(struct trace_iterator *iter) { }
 329 static void wakeup_trace_close(struct trace_iterator *iter) { }
 330
 331 #ifdef CONFIG_FUNCTION_TRACER
 332 static void wakeup_print_header(struct seq_file *s)
 333 {
 334         trace_default_header(s);
 335 }
 336 #else
 337 static void wakeup_print_header(struct seq_file *s)
 338 {
 339         trace_latency_header(s);
 340 }
 341 #endif /* CONFIG_FUNCTION_TRACER */
 342 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 343
 344 /*
 345  * Should this new latency be reported/recorded?
 346  */
 347 static int report_latency(struct trace_array *tr, cycle_t delta)
 348 {
 349         if (tracing_thresh) {
 350                 if (delta < tracing_thresh)
 351                         return 0;
 352         } else {
 353                 if (delta <= tr->max_latency)
 354                         return 0;
 355         }
 356         return 1;
 357 }
 358
 359 static void
 360 probe_wakeup_migrate_task(void *ignore, struct task_struct *task, int cpu)
 361 {
 362         if (task != wakeup_task)
 363                 return;
 364
 365         wakeup_current_cpu = cpu;
 366 }
 367
 368 static void notrace
 369 probe_wakeup_sched_switch(void *ignore,
 370                           struct task_struct *prev, struct task_struct *next)
 371 {
 372         struct trace_array_cpu *data;
 373         cycle_t T0, T1, delta;
 374         unsigned long flags;
 375         long disabled;
 376         int cpu;
 377         int pc;
 378
 379         tracing_record_cmdline(prev);
 380
 381         if (unlikely(!tracer_enabled))
 382                 return;
 383
 384         /*
 385          * When we start a new trace, we set wakeup_task to NULL
 386          * and then set tracer_enabled = 1. We want to make sure
 387          * that another CPU does not see the tracer_enabled = 1
 388          * and the wakeup_task with an older task, that might
 389          * actually be the same as next.
 390          */
 391         smp_rmb();
 392
 393         if (next != wakeup_task)
 394                 return;
 395
 396         pc = preempt_count();
 397
 398         /* disable local data, not wakeup_cpu data */
 399         cpu = raw_smp_processor_id();
 400         disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled);
 401         if (likely(disabled != 1))
 402                 goto out;
 403
 404         local_irq_save(flags);
 405         arch_spin_lock(&wakeup_lock);
 406
 407         /* We could race with grabbing wakeup_lock */
 408         if (unlikely(!tracer_enabled || next != wakeup_task))
 409                 goto out_unlock;
 410
 411         /* The task we are waiting for is waking up */
 412         data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu);
 413
 414         __trace_function(wakeup_trace, CALLER_ADDR0, CALLER_ADDR1, flags, pc);
 415         tracing_sched_switch_trace(wakeup_trace, prev, next, flags, pc);
 416
 417         T0 = data->preempt_timestamp;
 418         T1 = ftrace_now(cpu);
 419         delta = T1-T0;
 420
 421         if (!report_latency(wakeup_trace, delta))
 422                 goto out_unlock;
 423
 424         if (likely(!is_tracing_stopped())) {
 425                 wakeup_trace->max_latency = delta;
 426                 update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu);
 427         }
 428
 429 out_unlock:
 430         __wakeup_reset(wakeup_trace);
 431         arch_spin_unlock(&wakeup_lock);
 432         local_irq_restore(flags);
 433 out:
 434         atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled);
 435 }
 436
 437 static void __wakeup_reset(struct trace_array *tr)
 438 {
 439         wakeup_cpu = -1;
 440         wakeup_prio = -1;
 441         tracing_dl = 0;
 442
 443         if (wakeup_task)
 444                 put_task_struct(wakeup_task);
 445
 446         wakeup_task = NULL;
 447 }
 448
 449 static void wakeup_reset(struct trace_array *tr)
 450 {
 451         unsigned long flags;
 452
 453         tracing_reset_online_cpus(&tr->trace_buffer);
 454
 455         local_irq_save(flags);
 456         arch_spin_lock(&wakeup_lock);
 457         __wakeup_reset(tr);
 458         arch_spin_unlock(&wakeup_lock);
 459         local_irq_restore(flags);
 460 }
 461
 462 static void
 463 probe_wakeup(void *ignore, struct task_struct *p, int success)
 464 {
 465         struct trace_array_cpu *data;
 466         int cpu = smp_processor_id();
 467         unsigned long flags;
 468         long disabled;
 469         int pc;
 470
 471         if (likely(!tracer_enabled))
 472                 return;
 473
 474         tracing_record_cmdline(p);
 475         tracing_record_cmdline(current);
 476
 477         /*
 478          * Semantic is like this:
 479          *  - wakeup tracer handles all tasks in the system, independently
 480          *    from their scheduling class;
 481          *  - wakeup_rt tracer handles tasks belonging to sched_dl and
 482          *    sched_rt class;
 483          *  - wakeup_dl handles tasks belonging to sched_dl class only.
 484          */
 485         if (tracing_dl || (wakeup_dl && !dl_task(p)) ||
 486             (wakeup_rt && !dl_task(p) && !rt_task(p)) ||
 487             (!dl_task(p) && (p->prio >= wakeup_prio || p->prio >= current->prio)))
 488                 return;
 489
 490         pc = preempt_count();
 491         disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled);
 492         if (unlikely(disabled != 1))
 493                 goto out;
 494
 495         /* interrupts should be off from try_to_wake_up */
 496         arch_spin_lock(&wakeup_lock);
 497
 498         /* check for races. */
 499         if (!tracer_enabled || tracing_dl ||
 500             (!dl_task(p) && p->prio >= wakeup_prio))
 501                 goto out_locked;
 502
 503         /* reset the trace */
 504         __wakeup_reset(wakeup_trace);
 505
 506         wakeup_cpu = task_cpu(p);
 507         wakeup_current_cpu = wakeup_cpu;
 508         wakeup_prio = p->prio;
 509
 510         /*
 511          * Once you start tracing a -deadline task, don't bother tracing
 512          * another task until the first one wakes up.
 513          */
 514         if (dl_task(p))
 515                 tracing_dl = 1;
 516         else
 517                 tracing_dl = 0;
 518
 519         wakeup_task = p;
 520         get_task_struct(wakeup_task);
 521
 522         local_save_flags(flags);
 523
 524         data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu);
 525         data->preempt_timestamp = ftrace_now(cpu);
 526         tracing_sched_wakeup_trace(wakeup_trace, p, current, flags, pc);
 527
 528         /*
 529          * We must be careful in using CALLER_ADDR2. But since wake_up
 530          * is not called by an assembly function  (where as schedule is)
 531          * it should be safe to use it here.
 532          */
 533         __trace_function(wakeup_trace, CALLER_ADDR1, CALLER_ADDR2, flags, pc);
 534
 535 out_locked:
 536         arch_spin_unlock(&wakeup_lock);
 537 out:
 538         atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled);
 539 }
 540
 541 static void start_wakeup_tracer(struct trace_array *tr)
 542 {
 543         int ret;
 544
 545         ret = register_trace_sched_wakeup(probe_wakeup, NULL);
 546         if (ret) {
 547                 pr_info("wakeup trace: Couldn't activate tracepoint"
 548                         " probe to kernel_sched_wakeup\n");
 549                 return;
 550         }
 551
 552         ret = register_trace_sched_wakeup_new(probe_wakeup, NULL);
 553         if (ret) {
 554                 pr_info("wakeup trace: Couldn't activate tracepoint"
 555                         " probe to kernel_sched_wakeup_new\n");
 556                 goto fail_deprobe;
 557         }
 558
 559         ret = register_trace_sched_switch(probe_wakeup_sched_switch, NULL);
 560         if (ret) {
 561                 pr_info("sched trace: Couldn't activate tracepoint"
 562                         " probe to kernel_sched_switch\n");
 563                 goto fail_deprobe_wake_new;
 564         }
 565
 566         ret = register_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL);
 567         if (ret) {
 568                 pr_info("wakeup trace: Couldn't activate tracepoint"
 569                         " probe to kernel_sched_migrate_task\n");
 570                 return;
 571         }
 572
 573         wakeup_reset(tr);
 574
 575         /*
 576          * Don't let the tracer_enabled = 1 show up before
 577          * the wakeup_task is reset. This may be overkill since
 578          * wakeup_reset does a spin_unlock after setting the
 579          * wakeup_task to NULL, but I want to be safe.
 580          * This is a slow path anyway.
 581          */
 582         smp_wmb();
 583
 584         if (start_func_tracer(tr, is_graph()))
 585                 printk(KERN_ERR "failed to start wakeup tracer\n");
 586
 587         return;
 588 fail_deprobe_wake_new:
 589         unregister_trace_sched_wakeup_new(probe_wakeup, NULL);
 590 fail_deprobe:
 591         unregister_trace_sched_wakeup(probe_wakeup, NULL);
 592 }
 593
 594 static void stop_wakeup_tracer(struct trace_array *tr)
 595 {
 596         tracer_enabled = 0;
 597         stop_func_tracer(tr, is_graph());
 598         unregister_trace_sched_switch(probe_wakeup_sched_switch, NULL);
 599         unregister_trace_sched_wakeup_new(probe_wakeup, NULL);
 600         unregister_trace_sched_wakeup(probe_wakeup, NULL);
 601         unregister_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL);
 602 }
 603
 604 static bool wakeup_busy;
 605
 606 static int __wakeup_tracer_init(struct trace_array *tr)
 607 {
 608         save_flags = trace_flags;
 609
 610         /* non overwrite screws up the latency tracers */
 611         set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1);
 612         set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1);
 613
 614         tr->max_latency = 0;
 615         wakeup_trace = tr;
 616         ftrace_init_array_ops(tr, wakeup_tracer_call);
 617         start_wakeup_tracer(tr);
 618
 619         wakeup_busy = true;
 620         return 0;
 621 }
 622
 623 static int wakeup_tracer_init(struct trace_array *tr)
 624 {
 625         if (wakeup_busy)
 626                 return -EBUSY;
 627
 628         wakeup_dl = 0;
 629         wakeup_rt = 0;
 630         return __wakeup_tracer_init(tr);
 631 }
 632
 633 static int wakeup_rt_tracer_init(struct trace_array *tr)
 634 {
 635         if (wakeup_busy)
 636                 return -EBUSY;
 637
 638         wakeup_dl = 0;
 639         wakeup_rt = 1;
 640         return __wakeup_tracer_init(tr);
 641 }
 642
 643 static int wakeup_dl_tracer_init(struct trace_array *tr)
 644 {
 645         if (wakeup_busy)
 646                 return -EBUSY;
 647
 648         wakeup_dl = 1;
 649         wakeup_rt = 0;
 650         return __wakeup_tracer_init(tr);
 651 }
 652
 653 static void wakeup_tracer_reset(struct trace_array *tr)
 654 {
 655         int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT;
 656         int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE;
 657
 658         stop_wakeup_tracer(tr);
 659         /* make sure we put back any tasks we are tracing */
 660         wakeup_reset(tr);
 661
 662         set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag);
 663         set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag);
 664         ftrace_reset_array_ops(tr);
 665         wakeup_busy = false;
 666 }
 667
 668 static void wakeup_tracer_start(struct trace_array *tr)
 669 {
 670         wakeup_reset(tr);
 671         tracer_enabled = 1;
 672 }
 673
 674 static void wakeup_tracer_stop(struct trace_array *tr)
 675 {
 676         tracer_enabled = 0;
 677 }
 678
 679 static struct tracer wakeup_tracer __read_mostly =
 680 {
 681         .name           = "wakeup",
 682         .init           = wakeup_tracer_init,
 683         .reset          = wakeup_tracer_reset,
 684         .start          = wakeup_tracer_start,
 685         .stop           = wakeup_tracer_stop,
 686         .print_max      = true,
 687         .print_header   = wakeup_print_header,
 688         .print_line     = wakeup_print_line,
 689         .flags          = &tracer_flags,
 690         .set_flag       = wakeup_set_flag,
 691         .flag_changed   = wakeup_flag_changed,
 692 #ifdef CONFIG_FTRACE_SELFTEST
 693         .selftest    = trace_selftest_startup_wakeup,
 694 #endif
 695         .open           = wakeup_trace_open,
 696         .close          = wakeup_trace_close,
 697         .allow_instances = true,
 698         .use_max_tr     = true,
 699 };
 700
 701 static struct tracer wakeup_rt_tracer __read_mostly =
 702 {
 703         .name           = "wakeup_rt",
 704         .init           = wakeup_rt_tracer_init,
 705         .reset          = wakeup_tracer_reset,
 706         .start          = wakeup_tracer_start,
 707         .stop           = wakeup_tracer_stop,
 708         .print_max      = true,
 709         .print_header   = wakeup_print_header,
 710         .print_line     = wakeup_print_line,
 711         .flags          = &tracer_flags,
 712         .set_flag       = wakeup_set_flag,
 713         .flag_changed   = wakeup_flag_changed,
 714 #ifdef CONFIG_FTRACE_SELFTEST
 715         .selftest    = trace_selftest_startup_wakeup,
 716 #endif
 717         .open           = wakeup_trace_open,
 718         .close          = wakeup_trace_close,
 719         .allow_instances = true,
 720         .use_max_tr     = true,
 721 };
 722
 723 static struct tracer wakeup_dl_tracer __read_mostly =
 724 {
 725         .name           = "wakeup_dl",
 726         .init           = wakeup_dl_tracer_init,
 727         .reset          = wakeup_tracer_reset,
 728         .start          = wakeup_tracer_start,
 729         .stop           = wakeup_tracer_stop,
 730         .print_max      = true,
 731         .print_header   = wakeup_print_header,
 732         .print_line     = wakeup_print_line,
 733         .flags          = &tracer_flags,
 734         .set_flag       = wakeup_set_flag,
 735         .flag_changed   = wakeup_flag_changed,
 736 #ifdef CONFIG_FTRACE_SELFTEST
 737         .selftest    = trace_selftest_startup_wakeup,
 738 #endif
 739         .open           = wakeup_trace_open,
 740         .close          = wakeup_trace_close,
 741         .use_max_tr     = true,
 742 };
 743
 744 __init static int init_wakeup_tracer(void)
 745 {
 746         int ret;
 747
 748         ret = register_tracer(&wakeup_tracer);
 749         if (ret)
 750                 return ret;
 751
 752         ret = register_tracer(&wakeup_rt_tracer);
 753         if (ret)
 754                 return ret;
 755
 756         ret = register_tracer(&wakeup_dl_tracer);
 757         if (ret)
 758                 return ret;
 759
 760         return 0;
 761 }
 762 core_initcall(init_wakeup_tracer);