Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 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 William Lee Irwin III |
| 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> |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 18 | #include <linux/marker.h> |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 19 | |
| 20 | #include "trace.h" |
| 21 | |
| 22 | static struct trace_array *wakeup_trace; |
| 23 | static int __read_mostly tracer_enabled; |
| 24 | |
| 25 | static struct task_struct *wakeup_task; |
| 26 | static int wakeup_cpu; |
| 27 | static unsigned wakeup_prio = -1; |
| 28 | |
| 29 | static DEFINE_SPINLOCK(wakeup_lock); |
| 30 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 31 | static void __wakeup_reset(struct trace_array *tr); |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 32 | |
Steven Rostedt | 7e18d8e | 2008-05-22 00:22:19 -0400 | [diff] [blame] | 33 | #ifdef CONFIG_FTRACE |
| 34 | /* |
| 35 | * irqsoff uses its own tracer function to keep the overhead down: |
| 36 | */ |
| 37 | static void |
| 38 | wakeup_tracer_call(unsigned long ip, unsigned long parent_ip) |
| 39 | { |
| 40 | struct trace_array *tr = wakeup_trace; |
| 41 | struct trace_array_cpu *data; |
| 42 | unsigned long flags; |
| 43 | long disabled; |
| 44 | int resched; |
| 45 | int cpu; |
| 46 | |
| 47 | if (likely(!wakeup_task)) |
| 48 | return; |
| 49 | |
| 50 | resched = need_resched(); |
| 51 | preempt_disable_notrace(); |
| 52 | |
| 53 | cpu = raw_smp_processor_id(); |
| 54 | data = tr->data[cpu]; |
| 55 | disabled = atomic_inc_return(&data->disabled); |
| 56 | if (unlikely(disabled != 1)) |
| 57 | goto out; |
| 58 | |
| 59 | spin_lock_irqsave(&wakeup_lock, flags); |
| 60 | |
| 61 | if (unlikely(!wakeup_task)) |
| 62 | goto unlock; |
| 63 | |
| 64 | /* |
| 65 | * The task can't disappear because it needs to |
| 66 | * wake up first, and we have the wakeup_lock. |
| 67 | */ |
| 68 | if (task_cpu(wakeup_task) != cpu) |
| 69 | goto unlock; |
| 70 | |
| 71 | trace_function(tr, data, ip, parent_ip, flags); |
| 72 | |
| 73 | unlock: |
| 74 | spin_unlock_irqrestore(&wakeup_lock, flags); |
| 75 | |
| 76 | out: |
| 77 | atomic_dec(&data->disabled); |
| 78 | |
| 79 | /* |
| 80 | * To prevent recursion from the scheduler, if the |
| 81 | * resched flag was set before we entered, then |
| 82 | * don't reschedule. |
| 83 | */ |
| 84 | if (resched) |
| 85 | preempt_enable_no_resched_notrace(); |
| 86 | else |
| 87 | preempt_enable_notrace(); |
| 88 | } |
| 89 | |
| 90 | static struct ftrace_ops trace_ops __read_mostly = |
| 91 | { |
| 92 | .func = wakeup_tracer_call, |
| 93 | }; |
| 94 | #endif /* CONFIG_FTRACE */ |
| 95 | |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 96 | /* |
| 97 | * Should this new latency be reported/recorded? |
| 98 | */ |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 99 | static int report_latency(cycle_t delta) |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 100 | { |
| 101 | if (tracing_thresh) { |
| 102 | if (delta < tracing_thresh) |
| 103 | return 0; |
| 104 | } else { |
| 105 | if (delta <= tracing_max_latency) |
| 106 | return 0; |
| 107 | } |
| 108 | return 1; |
| 109 | } |
| 110 | |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 111 | static void notrace |
| 112 | wakeup_sched_switch(void *private, void *rq, struct task_struct *prev, |
| 113 | struct task_struct *next) |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 114 | { |
| 115 | unsigned long latency = 0, t0 = 0, t1 = 0; |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 116 | struct trace_array **ptr = private; |
| 117 | struct trace_array *tr = *ptr; |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 118 | struct trace_array_cpu *data; |
| 119 | cycle_t T0, T1, delta; |
| 120 | unsigned long flags; |
| 121 | long disabled; |
| 122 | int cpu; |
| 123 | |
| 124 | if (unlikely(!tracer_enabled)) |
| 125 | return; |
| 126 | |
| 127 | /* |
| 128 | * When we start a new trace, we set wakeup_task to NULL |
| 129 | * and then set tracer_enabled = 1. We want to make sure |
| 130 | * that another CPU does not see the tracer_enabled = 1 |
| 131 | * and the wakeup_task with an older task, that might |
| 132 | * actually be the same as next. |
| 133 | */ |
| 134 | smp_rmb(); |
| 135 | |
| 136 | if (next != wakeup_task) |
| 137 | return; |
| 138 | |
Steven Rostedt | 7e18d8e | 2008-05-22 00:22:19 -0400 | [diff] [blame] | 139 | /* The task we are waiting for is waking up */ |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 140 | data = tr->data[wakeup_cpu]; |
| 141 | |
| 142 | /* disable local data, not wakeup_cpu data */ |
| 143 | cpu = raw_smp_processor_id(); |
| 144 | disabled = atomic_inc_return(&tr->data[cpu]->disabled); |
| 145 | if (likely(disabled != 1)) |
| 146 | goto out; |
| 147 | |
| 148 | spin_lock_irqsave(&wakeup_lock, flags); |
| 149 | |
| 150 | /* We could race with grabbing wakeup_lock */ |
| 151 | if (unlikely(!tracer_enabled || next != wakeup_task)) |
| 152 | goto out_unlock; |
| 153 | |
Steven Rostedt | 6fb44b7 | 2008-05-12 21:20:49 +0200 | [diff] [blame] | 154 | trace_function(tr, data, CALLER_ADDR1, CALLER_ADDR2, flags); |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 155 | |
| 156 | /* |
| 157 | * usecs conversion is slow so we try to delay the conversion |
| 158 | * as long as possible: |
| 159 | */ |
| 160 | T0 = data->preempt_timestamp; |
Ingo Molnar | 750ed1a | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 161 | T1 = ftrace_now(cpu); |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 162 | delta = T1-T0; |
| 163 | |
| 164 | if (!report_latency(delta)) |
| 165 | goto out_unlock; |
| 166 | |
| 167 | latency = nsecs_to_usecs(delta); |
| 168 | |
| 169 | tracing_max_latency = delta; |
| 170 | t0 = nsecs_to_usecs(T0); |
| 171 | t1 = nsecs_to_usecs(T1); |
| 172 | |
| 173 | update_max_tr(tr, wakeup_task, wakeup_cpu); |
| 174 | |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 175 | out_unlock: |
| 176 | __wakeup_reset(tr); |
| 177 | spin_unlock_irqrestore(&wakeup_lock, flags); |
| 178 | out: |
| 179 | atomic_dec(&tr->data[cpu]->disabled); |
| 180 | } |
| 181 | |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 182 | static notrace void |
| 183 | sched_switch_callback(void *probe_data, void *call_data, |
| 184 | const char *format, va_list *args) |
| 185 | { |
| 186 | struct task_struct *prev; |
| 187 | struct task_struct *next; |
| 188 | struct rq *__rq; |
| 189 | |
| 190 | /* skip prev_pid %d next_pid %d prev_state %ld */ |
| 191 | (void)va_arg(*args, int); |
| 192 | (void)va_arg(*args, int); |
| 193 | (void)va_arg(*args, long); |
| 194 | __rq = va_arg(*args, typeof(__rq)); |
| 195 | prev = va_arg(*args, typeof(prev)); |
| 196 | next = va_arg(*args, typeof(next)); |
| 197 | |
| 198 | tracing_record_cmdline(prev); |
| 199 | |
| 200 | /* |
| 201 | * If tracer_switch_func only points to the local |
| 202 | * switch func, it still needs the ptr passed to it. |
| 203 | */ |
| 204 | wakeup_sched_switch(probe_data, __rq, prev, next); |
| 205 | } |
| 206 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 207 | static void __wakeup_reset(struct trace_array *tr) |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 208 | { |
| 209 | struct trace_array_cpu *data; |
| 210 | int cpu; |
| 211 | |
| 212 | assert_spin_locked(&wakeup_lock); |
| 213 | |
| 214 | for_each_possible_cpu(cpu) { |
| 215 | data = tr->data[cpu]; |
| 216 | tracing_reset(data); |
| 217 | } |
| 218 | |
| 219 | wakeup_cpu = -1; |
| 220 | wakeup_prio = -1; |
| 221 | |
| 222 | if (wakeup_task) |
| 223 | put_task_struct(wakeup_task); |
| 224 | |
| 225 | wakeup_task = NULL; |
| 226 | } |
| 227 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 228 | static void wakeup_reset(struct trace_array *tr) |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 229 | { |
| 230 | unsigned long flags; |
| 231 | |
| 232 | spin_lock_irqsave(&wakeup_lock, flags); |
| 233 | __wakeup_reset(tr); |
| 234 | spin_unlock_irqrestore(&wakeup_lock, flags); |
| 235 | } |
| 236 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 237 | static void |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 238 | wakeup_check_start(struct trace_array *tr, struct task_struct *p, |
| 239 | struct task_struct *curr) |
| 240 | { |
| 241 | int cpu = smp_processor_id(); |
| 242 | unsigned long flags; |
| 243 | long disabled; |
| 244 | |
| 245 | if (likely(!rt_task(p)) || |
| 246 | p->prio >= wakeup_prio || |
| 247 | p->prio >= curr->prio) |
| 248 | return; |
| 249 | |
| 250 | disabled = atomic_inc_return(&tr->data[cpu]->disabled); |
| 251 | if (unlikely(disabled != 1)) |
| 252 | goto out; |
| 253 | |
| 254 | /* interrupts should be off from try_to_wake_up */ |
| 255 | spin_lock(&wakeup_lock); |
| 256 | |
| 257 | /* check for races. */ |
| 258 | if (!tracer_enabled || p->prio >= wakeup_prio) |
| 259 | goto out_locked; |
| 260 | |
| 261 | /* reset the trace */ |
| 262 | __wakeup_reset(tr); |
| 263 | |
| 264 | wakeup_cpu = task_cpu(p); |
| 265 | wakeup_prio = p->prio; |
| 266 | |
| 267 | wakeup_task = p; |
| 268 | get_task_struct(wakeup_task); |
| 269 | |
| 270 | local_save_flags(flags); |
| 271 | |
Ingo Molnar | 750ed1a | 2008-05-12 21:20:46 +0200 | [diff] [blame] | 272 | tr->data[wakeup_cpu]->preempt_timestamp = ftrace_now(cpu); |
Steven Rostedt | 6fb44b7 | 2008-05-12 21:20:49 +0200 | [diff] [blame] | 273 | trace_function(tr, tr->data[wakeup_cpu], |
| 274 | CALLER_ADDR1, CALLER_ADDR2, flags); |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 275 | |
| 276 | out_locked: |
| 277 | spin_unlock(&wakeup_lock); |
| 278 | out: |
| 279 | atomic_dec(&tr->data[cpu]->disabled); |
| 280 | } |
| 281 | |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 282 | static notrace void |
| 283 | wake_up_callback(void *probe_data, void *call_data, |
| 284 | const char *format, va_list *args) |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 285 | { |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 286 | struct trace_array **ptr = probe_data; |
| 287 | struct trace_array *tr = *ptr; |
| 288 | struct task_struct *curr; |
| 289 | struct task_struct *task; |
| 290 | struct rq *__rq; |
| 291 | |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 292 | if (likely(!tracer_enabled)) |
| 293 | return; |
| 294 | |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 295 | /* Skip pid %d state %ld */ |
| 296 | (void)va_arg(*args, int); |
| 297 | (void)va_arg(*args, long); |
| 298 | /* now get the meat: "rq %p task %p rq->curr %p" */ |
| 299 | __rq = va_arg(*args, typeof(__rq)); |
| 300 | task = va_arg(*args, typeof(task)); |
| 301 | curr = va_arg(*args, typeof(curr)); |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 302 | |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 303 | tracing_record_cmdline(task); |
| 304 | tracing_record_cmdline(curr); |
| 305 | |
| 306 | wakeup_check_start(tr, task, curr); |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 307 | } |
| 308 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 309 | static void start_wakeup_tracer(struct trace_array *tr) |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 310 | { |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 311 | int ret; |
| 312 | |
| 313 | ret = marker_probe_register("kernel_sched_wakeup", |
| 314 | "pid %d state %ld ## rq %p task %p rq->curr %p", |
| 315 | wake_up_callback, |
| 316 | &wakeup_trace); |
| 317 | if (ret) { |
| 318 | pr_info("wakeup trace: Couldn't add marker" |
| 319 | " probe to kernel_sched_wakeup\n"); |
| 320 | return; |
| 321 | } |
| 322 | |
| 323 | ret = marker_probe_register("kernel_sched_wakeup_new", |
| 324 | "pid %d state %ld ## rq %p task %p rq->curr %p", |
| 325 | wake_up_callback, |
| 326 | &wakeup_trace); |
| 327 | if (ret) { |
| 328 | pr_info("wakeup trace: Couldn't add marker" |
| 329 | " probe to kernel_sched_wakeup_new\n"); |
| 330 | goto fail_deprobe; |
| 331 | } |
| 332 | |
| 333 | ret = marker_probe_register("kernel_sched_schedule", |
| 334 | "prev_pid %d next_pid %d prev_state %ld " |
| 335 | "## rq %p prev %p next %p", |
| 336 | sched_switch_callback, |
| 337 | &wakeup_trace); |
| 338 | if (ret) { |
| 339 | pr_info("sched trace: Couldn't add marker" |
| 340 | " probe to kernel_sched_schedule\n"); |
| 341 | goto fail_deprobe_wake_new; |
| 342 | } |
| 343 | |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 344 | wakeup_reset(tr); |
| 345 | |
| 346 | /* |
| 347 | * Don't let the tracer_enabled = 1 show up before |
| 348 | * the wakeup_task is reset. This may be overkill since |
| 349 | * wakeup_reset does a spin_unlock after setting the |
| 350 | * wakeup_task to NULL, but I want to be safe. |
| 351 | * This is a slow path anyway. |
| 352 | */ |
| 353 | smp_wmb(); |
| 354 | |
Steven Rostedt | 7e18d8e | 2008-05-22 00:22:19 -0400 | [diff] [blame] | 355 | register_ftrace_function(&trace_ops); |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 356 | |
Steven Rostedt | ad59124 | 2008-07-10 20:58:13 -0400 | [diff] [blame^] | 357 | tracer_enabled = 1; |
| 358 | |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 359 | return; |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 360 | fail_deprobe_wake_new: |
| 361 | marker_probe_unregister("kernel_sched_wakeup_new", |
| 362 | wake_up_callback, |
| 363 | &wakeup_trace); |
| 364 | fail_deprobe: |
| 365 | marker_probe_unregister("kernel_sched_wakeup", |
| 366 | wake_up_callback, |
| 367 | &wakeup_trace); |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 368 | } |
| 369 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 370 | static void stop_wakeup_tracer(struct trace_array *tr) |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 371 | { |
| 372 | tracer_enabled = 0; |
Steven Rostedt | 7e18d8e | 2008-05-22 00:22:19 -0400 | [diff] [blame] | 373 | unregister_ftrace_function(&trace_ops); |
Mathieu Desnoyers | 5b82a1b | 2008-05-12 21:21:10 +0200 | [diff] [blame] | 374 | marker_probe_unregister("kernel_sched_schedule", |
| 375 | sched_switch_callback, |
| 376 | &wakeup_trace); |
| 377 | marker_probe_unregister("kernel_sched_wakeup_new", |
| 378 | wake_up_callback, |
| 379 | &wakeup_trace); |
| 380 | marker_probe_unregister("kernel_sched_wakeup", |
| 381 | wake_up_callback, |
| 382 | &wakeup_trace); |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 383 | } |
| 384 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 385 | static void wakeup_tracer_init(struct trace_array *tr) |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 386 | { |
| 387 | wakeup_trace = tr; |
| 388 | |
| 389 | if (tr->ctrl) |
| 390 | start_wakeup_tracer(tr); |
| 391 | } |
| 392 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 393 | static void wakeup_tracer_reset(struct trace_array *tr) |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 394 | { |
| 395 | if (tr->ctrl) { |
| 396 | stop_wakeup_tracer(tr); |
| 397 | /* make sure we put back any tasks we are tracing */ |
| 398 | wakeup_reset(tr); |
| 399 | } |
| 400 | } |
| 401 | |
| 402 | static void wakeup_tracer_ctrl_update(struct trace_array *tr) |
| 403 | { |
| 404 | if (tr->ctrl) |
| 405 | start_wakeup_tracer(tr); |
| 406 | else |
| 407 | stop_wakeup_tracer(tr); |
| 408 | } |
| 409 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 410 | static void wakeup_tracer_open(struct trace_iterator *iter) |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 411 | { |
| 412 | /* stop the trace while dumping */ |
| 413 | if (iter->tr->ctrl) |
| 414 | stop_wakeup_tracer(iter->tr); |
| 415 | } |
| 416 | |
Ingo Molnar | e309b41 | 2008-05-12 21:20:51 +0200 | [diff] [blame] | 417 | static void wakeup_tracer_close(struct trace_iterator *iter) |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 418 | { |
| 419 | /* forget about any processes we were recording */ |
| 420 | if (iter->tr->ctrl) |
| 421 | start_wakeup_tracer(iter->tr); |
| 422 | } |
| 423 | |
| 424 | static struct tracer wakeup_tracer __read_mostly = |
| 425 | { |
| 426 | .name = "wakeup", |
| 427 | .init = wakeup_tracer_init, |
| 428 | .reset = wakeup_tracer_reset, |
| 429 | .open = wakeup_tracer_open, |
| 430 | .close = wakeup_tracer_close, |
| 431 | .ctrl_update = wakeup_tracer_ctrl_update, |
| 432 | .print_max = 1, |
Steven Rostedt | 60a1177 | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 433 | #ifdef CONFIG_FTRACE_SELFTEST |
| 434 | .selftest = trace_selftest_startup_wakeup, |
| 435 | #endif |
Steven Rostedt | 352ad25 | 2008-05-12 21:20:42 +0200 | [diff] [blame] | 436 | }; |
| 437 | |
| 438 | __init static int init_wakeup_tracer(void) |
| 439 | { |
| 440 | int ret; |
| 441 | |
| 442 | ret = register_tracer(&wakeup_tracer); |
| 443 | if (ret) |
| 444 | return ret; |
| 445 | |
| 446 | return 0; |
| 447 | } |
| 448 | device_initcall(init_wakeup_tracer); |