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Commit | Line | Data |
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352ad25a SR |
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 | |
6d49e352 | 10 | * Copyright (C) 2004 Nadia Yvette Chambers |
352ad25a SR |
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> | |
8bd75c77 | 18 | #include <linux/sched/rt.h> |
2d3d891d | 19 | #include <linux/sched/deadline.h> |
ad8d75ff | 20 | #include <trace/events/sched.h> |
352ad25a SR |
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; | |
478142c3 | 28 | static int wakeup_current_cpu; |
352ad25a | 29 | static unsigned wakeup_prio = -1; |
3244351c | 30 | static int wakeup_rt; |
af6ace76 DF |
31 | static int wakeup_dl; |
32 | static int tracing_dl = 0; | |
352ad25a | 33 | |
445c8951 | 34 | static arch_spinlock_t wakeup_lock = |
edc35bd7 | 35 | (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; |
352ad25a | 36 | |
7495a5be | 37 | static void wakeup_reset(struct trace_array *tr); |
e309b41d | 38 | static void __wakeup_reset(struct trace_array *tr); |
7495a5be JO |
39 | static int wakeup_graph_entry(struct ftrace_graph_ent *trace); |
40 | static void wakeup_graph_return(struct ftrace_graph_ret *trace); | |
352ad25a | 41 | |
613f04a0 | 42 | static int save_flags; |
328df475 | 43 | static bool function_enabled; |
e9d25fe6 | 44 | |
7495a5be JO |
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 | ||
606576ce | 62 | #ifdef CONFIG_FUNCTION_TRACER |
542181d3 | 63 | |
7e18d8e7 | 64 | /* |
542181d3 SR |
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. | |
7e18d8e7 | 77 | */ |
542181d3 SR |
78 | static int |
79 | func_prolog_preempt_disable(struct trace_array *tr, | |
80 | struct trace_array_cpu **data, | |
81 | int *pc) | |
7e18d8e7 | 82 | { |
7e18d8e7 | 83 | long disabled; |
7e18d8e7 SR |
84 | int cpu; |
85 | ||
86 | if (likely(!wakeup_task)) | |
542181d3 | 87 | return 0; |
7e18d8e7 | 88 | |
542181d3 | 89 | *pc = preempt_count(); |
5168ae50 | 90 | preempt_disable_notrace(); |
7e18d8e7 SR |
91 | |
92 | cpu = raw_smp_processor_id(); | |
478142c3 SR |
93 | if (cpu != wakeup_current_cpu) |
94 | goto out_enable; | |
95 | ||
12883efb | 96 | *data = per_cpu_ptr(tr->trace_buffer.data, cpu); |
542181d3 | 97 | disabled = atomic_inc_return(&(*data)->disabled); |
7e18d8e7 SR |
98 | if (unlikely(disabled != 1)) |
99 | goto out; | |
100 | ||
542181d3 | 101 | return 1; |
7e18d8e7 | 102 | |
542181d3 SR |
103 | out: |
104 | atomic_dec(&(*data)->disabled); | |
7e18d8e7 | 105 | |
542181d3 SR |
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 | |
a1e2e31d SR |
115 | wakeup_tracer_call(unsigned long ip, unsigned long parent_ip, |
116 | struct ftrace_ops *op, struct pt_regs *pt_regs) | |
542181d3 SR |
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); | |
e59494f4 | 128 | local_irq_restore(flags); |
7e18d8e7 | 129 | |
7e18d8e7 | 130 | atomic_dec(&data->disabled); |
5168ae50 | 131 | preempt_enable_notrace(); |
7e18d8e7 | 132 | } |
7e40798f | 133 | #endif /* CONFIG_FUNCTION_TRACER */ |
7495a5be | 134 | |
4104d326 | 135 | static int register_wakeup_function(struct trace_array *tr, int graph, int set) |
7495a5be JO |
136 | { |
137 | int ret; | |
138 | ||
328df475 SRRH |
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) | |
7495a5be JO |
144 | ret = register_ftrace_graph(&wakeup_graph_return, |
145 | &wakeup_graph_entry); | |
328df475 | 146 | else |
4104d326 | 147 | ret = register_ftrace_function(tr->ops); |
328df475 SRRH |
148 | |
149 | if (!ret) | |
150 | function_enabled = true; | |
151 | ||
152 | return ret; | |
153 | } | |
154 | ||
4104d326 | 155 | static void unregister_wakeup_function(struct trace_array *tr, int graph) |
328df475 SRRH |
156 | { |
157 | if (!function_enabled) | |
158 | return; | |
159 | ||
160 | if (graph) | |
161 | unregister_ftrace_graph(); | |
162 | else | |
4104d326 | 163 | unregister_ftrace_function(tr->ops); |
328df475 SRRH |
164 | |
165 | function_enabled = false; | |
166 | } | |
167 | ||
4104d326 | 168 | static void wakeup_function_set(struct trace_array *tr, int set) |
328df475 SRRH |
169 | { |
170 | if (set) | |
4104d326 | 171 | register_wakeup_function(tr, is_graph(), 1); |
328df475 | 172 | else |
4104d326 | 173 | unregister_wakeup_function(tr, is_graph()); |
328df475 SRRH |
174 | } |
175 | ||
bf6065b5 | 176 | static int wakeup_flag_changed(struct trace_array *tr, u32 mask, int set) |
328df475 | 177 | { |
bf6065b5 SRRH |
178 | struct tracer *tracer = tr->current_trace; |
179 | ||
328df475 | 180 | if (mask & TRACE_ITER_FUNCTION) |
4104d326 | 181 | wakeup_function_set(tr, set); |
328df475 SRRH |
182 | |
183 | return trace_keep_overwrite(tracer, mask, set); | |
184 | } | |
185 | ||
4104d326 | 186 | static int start_func_tracer(struct trace_array *tr, int graph) |
328df475 SRRH |
187 | { |
188 | int ret; | |
189 | ||
4104d326 | 190 | ret = register_wakeup_function(tr, graph, 0); |
7495a5be JO |
191 | |
192 | if (!ret && tracing_is_enabled()) | |
193 | tracer_enabled = 1; | |
194 | else | |
195 | tracer_enabled = 0; | |
196 | ||
197 | return ret; | |
198 | } | |
199 | ||
4104d326 | 200 | static void stop_func_tracer(struct trace_array *tr, int graph) |
7495a5be JO |
201 | { |
202 | tracer_enabled = 0; | |
203 | ||
4104d326 | 204 | unregister_wakeup_function(tr, graph); |
7495a5be JO |
205 | } |
206 | ||
7495a5be | 207 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
8c1a49ae SRRH |
208 | static int |
209 | wakeup_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set) | |
7495a5be JO |
210 | { |
211 | ||
212 | if (!(bit & TRACE_DISPLAY_GRAPH)) | |
213 | return -EINVAL; | |
214 | ||
215 | if (!(is_graph() ^ set)) | |
216 | return 0; | |
217 | ||
4104d326 | 218 | stop_func_tracer(tr, !set); |
7495a5be JO |
219 | |
220 | wakeup_reset(wakeup_trace); | |
221 | tracing_max_latency = 0; | |
222 | ||
4104d326 | 223 | return start_func_tracer(tr, set); |
7495a5be JO |
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; | |
542181d3 | 231 | int pc, ret = 0; |
7495a5be | 232 | |
542181d3 | 233 | if (!func_prolog_preempt_disable(tr, &data, &pc)) |
7495a5be JO |
234 | return 0; |
235 | ||
7495a5be JO |
236 | local_save_flags(flags); |
237 | ret = __trace_graph_entry(tr, trace, flags, pc); | |
7495a5be | 238 | atomic_dec(&data->disabled); |
7495a5be | 239 | preempt_enable_notrace(); |
542181d3 | 240 | |
7495a5be JO |
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; | |
542181d3 | 249 | int pc; |
7495a5be | 250 | |
542181d3 | 251 | if (!func_prolog_preempt_disable(tr, &data, &pc)) |
7495a5be JO |
252 | return; |
253 | ||
7495a5be JO |
254 | local_save_flags(flags); |
255 | __trace_graph_return(tr, trace, flags, pc); | |
7495a5be JO |
256 | atomic_dec(&data->disabled); |
257 | ||
7495a5be JO |
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 | ||
321e68b0 JO |
274 | #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_PROC | \ |
275 | TRACE_GRAPH_PRINT_ABS_TIME | \ | |
276 | TRACE_GRAPH_PRINT_DURATION) | |
7495a5be JO |
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 | ||
8c1a49ae SRRH |
311 | static int |
312 | wakeup_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set) | |
7495a5be JO |
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) { } | |
7495a5be JO |
328 | static void wakeup_trace_open(struct trace_iterator *iter) { } |
329 | static void wakeup_trace_close(struct trace_iterator *iter) { } | |
7e9a49ef JO |
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 */ | |
7495a5be JO |
342 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
343 | ||
352ad25a SR |
344 | /* |
345 | * Should this new latency be reported/recorded? | |
346 | */ | |
e309b41d | 347 | static int report_latency(cycle_t delta) |
352ad25a SR |
348 | { |
349 | if (tracing_thresh) { | |
350 | if (delta < tracing_thresh) | |
351 | return 0; | |
352 | } else { | |
353 | if (delta <= tracing_max_latency) | |
354 | return 0; | |
355 | } | |
356 | return 1; | |
357 | } | |
358 | ||
38516ab5 SR |
359 | static void |
360 | probe_wakeup_migrate_task(void *ignore, struct task_struct *task, int cpu) | |
478142c3 SR |
361 | { |
362 | if (task != wakeup_task) | |
363 | return; | |
364 | ||
365 | wakeup_current_cpu = cpu; | |
366 | } | |
367 | ||
5b82a1b0 | 368 | static void notrace |
38516ab5 SR |
369 | probe_wakeup_sched_switch(void *ignore, |
370 | struct task_struct *prev, struct task_struct *next) | |
352ad25a | 371 | { |
352ad25a SR |
372 | struct trace_array_cpu *data; |
373 | cycle_t T0, T1, delta; | |
374 | unsigned long flags; | |
375 | long disabled; | |
376 | int cpu; | |
38697053 | 377 | int pc; |
352ad25a | 378 | |
b07c3f19 MD |
379 | tracing_record_cmdline(prev); |
380 | ||
352ad25a SR |
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 | ||
38697053 SR |
396 | pc = preempt_count(); |
397 | ||
352ad25a SR |
398 | /* disable local data, not wakeup_cpu data */ |
399 | cpu = raw_smp_processor_id(); | |
12883efb | 400 | disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); |
352ad25a SR |
401 | if (likely(disabled != 1)) |
402 | goto out; | |
403 | ||
e59494f4 | 404 | local_irq_save(flags); |
0199c4e6 | 405 | arch_spin_lock(&wakeup_lock); |
352ad25a SR |
406 | |
407 | /* We could race with grabbing wakeup_lock */ | |
408 | if (unlikely(!tracer_enabled || next != wakeup_task)) | |
409 | goto out_unlock; | |
410 | ||
9be24414 | 411 | /* The task we are waiting for is waking up */ |
12883efb | 412 | data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu); |
9be24414 | 413 | |
7495a5be | 414 | __trace_function(wakeup_trace, CALLER_ADDR0, CALLER_ADDR1, flags, pc); |
7be42151 | 415 | tracing_sched_switch_trace(wakeup_trace, prev, next, flags, pc); |
352ad25a | 416 | |
352ad25a | 417 | T0 = data->preempt_timestamp; |
750ed1a4 | 418 | T1 = ftrace_now(cpu); |
352ad25a SR |
419 | delta = T1-T0; |
420 | ||
421 | if (!report_latency(delta)) | |
422 | goto out_unlock; | |
423 | ||
b5130b1e CE |
424 | if (likely(!is_tracing_stopped())) { |
425 | tracing_max_latency = delta; | |
426 | update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu); | |
427 | } | |
352ad25a | 428 | |
352ad25a | 429 | out_unlock: |
b07c3f19 | 430 | __wakeup_reset(wakeup_trace); |
0199c4e6 | 431 | arch_spin_unlock(&wakeup_lock); |
e59494f4 | 432 | local_irq_restore(flags); |
352ad25a | 433 | out: |
12883efb | 434 | atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); |
5b82a1b0 MD |
435 | } |
436 | ||
e309b41d | 437 | static void __wakeup_reset(struct trace_array *tr) |
352ad25a | 438 | { |
352ad25a SR |
439 | wakeup_cpu = -1; |
440 | wakeup_prio = -1; | |
af6ace76 | 441 | tracing_dl = 0; |
352ad25a SR |
442 | |
443 | if (wakeup_task) | |
444 | put_task_struct(wakeup_task); | |
445 | ||
446 | wakeup_task = NULL; | |
447 | } | |
448 | ||
e309b41d | 449 | static void wakeup_reset(struct trace_array *tr) |
352ad25a SR |
450 | { |
451 | unsigned long flags; | |
452 | ||
12883efb | 453 | tracing_reset_online_cpus(&tr->trace_buffer); |
2f26ebd5 | 454 | |
e59494f4 | 455 | local_irq_save(flags); |
0199c4e6 | 456 | arch_spin_lock(&wakeup_lock); |
352ad25a | 457 | __wakeup_reset(tr); |
0199c4e6 | 458 | arch_spin_unlock(&wakeup_lock); |
e59494f4 | 459 | local_irq_restore(flags); |
352ad25a SR |
460 | } |
461 | ||
e309b41d | 462 | static void |
38516ab5 | 463 | probe_wakeup(void *ignore, struct task_struct *p, int success) |
352ad25a | 464 | { |
f8ec1062 | 465 | struct trace_array_cpu *data; |
352ad25a SR |
466 | int cpu = smp_processor_id(); |
467 | unsigned long flags; | |
468 | long disabled; | |
38697053 | 469 | int pc; |
352ad25a | 470 | |
b07c3f19 MD |
471 | if (likely(!tracer_enabled)) |
472 | return; | |
473 | ||
474 | tracing_record_cmdline(p); | |
475 | tracing_record_cmdline(current); | |
476 | ||
af6ace76 DF |
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))) | |
352ad25a SR |
488 | return; |
489 | ||
38697053 | 490 | pc = preempt_count(); |
12883efb | 491 | disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); |
352ad25a SR |
492 | if (unlikely(disabled != 1)) |
493 | goto out; | |
494 | ||
495 | /* interrupts should be off from try_to_wake_up */ | |
0199c4e6 | 496 | arch_spin_lock(&wakeup_lock); |
352ad25a SR |
497 | |
498 | /* check for races. */ | |
af6ace76 DF |
499 | if (!tracer_enabled || tracing_dl || |
500 | (!dl_task(p) && p->prio >= wakeup_prio)) | |
352ad25a SR |
501 | goto out_locked; |
502 | ||
503 | /* reset the trace */ | |
b07c3f19 | 504 | __wakeup_reset(wakeup_trace); |
352ad25a SR |
505 | |
506 | wakeup_cpu = task_cpu(p); | |
478142c3 | 507 | wakeup_current_cpu = wakeup_cpu; |
352ad25a SR |
508 | wakeup_prio = p->prio; |
509 | ||
af6ace76 DF |
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 | ||
352ad25a SR |
519 | wakeup_task = p; |
520 | get_task_struct(wakeup_task); | |
521 | ||
522 | local_save_flags(flags); | |
523 | ||
12883efb | 524 | data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu); |
f8ec1062 | 525 | data->preempt_timestamp = ftrace_now(cpu); |
7be42151 | 526 | tracing_sched_wakeup_trace(wakeup_trace, p, current, flags, pc); |
301fd748 SR |
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 | */ | |
7495a5be | 533 | __trace_function(wakeup_trace, CALLER_ADDR1, CALLER_ADDR2, flags, pc); |
352ad25a SR |
534 | |
535 | out_locked: | |
0199c4e6 | 536 | arch_spin_unlock(&wakeup_lock); |
352ad25a | 537 | out: |
12883efb | 538 | atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); |
352ad25a SR |
539 | } |
540 | ||
e309b41d | 541 | static void start_wakeup_tracer(struct trace_array *tr) |
352ad25a | 542 | { |
5b82a1b0 MD |
543 | int ret; |
544 | ||
38516ab5 | 545 | ret = register_trace_sched_wakeup(probe_wakeup, NULL); |
5b82a1b0 | 546 | if (ret) { |
b07c3f19 | 547 | pr_info("wakeup trace: Couldn't activate tracepoint" |
5b82a1b0 MD |
548 | " probe to kernel_sched_wakeup\n"); |
549 | return; | |
550 | } | |
551 | ||
38516ab5 | 552 | ret = register_trace_sched_wakeup_new(probe_wakeup, NULL); |
5b82a1b0 | 553 | if (ret) { |
b07c3f19 | 554 | pr_info("wakeup trace: Couldn't activate tracepoint" |
5b82a1b0 MD |
555 | " probe to kernel_sched_wakeup_new\n"); |
556 | goto fail_deprobe; | |
557 | } | |
558 | ||
38516ab5 | 559 | ret = register_trace_sched_switch(probe_wakeup_sched_switch, NULL); |
5b82a1b0 | 560 | if (ret) { |
b07c3f19 | 561 | pr_info("sched trace: Couldn't activate tracepoint" |
73d8b8bc | 562 | " probe to kernel_sched_switch\n"); |
5b82a1b0 MD |
563 | goto fail_deprobe_wake_new; |
564 | } | |
565 | ||
38516ab5 | 566 | ret = register_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL); |
478142c3 SR |
567 | if (ret) { |
568 | pr_info("wakeup trace: Couldn't activate tracepoint" | |
569 | " probe to kernel_sched_migrate_task\n"); | |
570 | return; | |
571 | } | |
572 | ||
352ad25a SR |
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 | ||
4104d326 | 584 | if (start_func_tracer(tr, is_graph())) |
7495a5be | 585 | printk(KERN_ERR "failed to start wakeup tracer\n"); |
ad591240 | 586 | |
352ad25a | 587 | return; |
5b82a1b0 | 588 | fail_deprobe_wake_new: |
38516ab5 | 589 | unregister_trace_sched_wakeup_new(probe_wakeup, NULL); |
5b82a1b0 | 590 | fail_deprobe: |
38516ab5 | 591 | unregister_trace_sched_wakeup(probe_wakeup, NULL); |
352ad25a SR |
592 | } |
593 | ||
e309b41d | 594 | static void stop_wakeup_tracer(struct trace_array *tr) |
352ad25a SR |
595 | { |
596 | tracer_enabled = 0; | |
4104d326 | 597 | stop_func_tracer(tr, is_graph()); |
38516ab5 SR |
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); | |
352ad25a SR |
602 | } |
603 | ||
3244351c | 604 | static int __wakeup_tracer_init(struct trace_array *tr) |
352ad25a | 605 | { |
613f04a0 SRRH |
606 | save_flags = trace_flags; |
607 | ||
608 | /* non overwrite screws up the latency tracers */ | |
2b6080f2 SR |
609 | set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1); |
610 | set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1); | |
e9d25fe6 | 611 | |
745b1626 | 612 | tracing_max_latency = 0; |
352ad25a | 613 | wakeup_trace = tr; |
4104d326 | 614 | ftrace_init_array_ops(tr, wakeup_tracer_call); |
c76f0694 | 615 | start_wakeup_tracer(tr); |
1c80025a | 616 | return 0; |
352ad25a SR |
617 | } |
618 | ||
3244351c SR |
619 | static int wakeup_tracer_init(struct trace_array *tr) |
620 | { | |
af6ace76 | 621 | wakeup_dl = 0; |
3244351c SR |
622 | wakeup_rt = 0; |
623 | return __wakeup_tracer_init(tr); | |
624 | } | |
625 | ||
626 | static int wakeup_rt_tracer_init(struct trace_array *tr) | |
627 | { | |
af6ace76 | 628 | wakeup_dl = 0; |
3244351c SR |
629 | wakeup_rt = 1; |
630 | return __wakeup_tracer_init(tr); | |
631 | } | |
632 | ||
af6ace76 DF |
633 | static int wakeup_dl_tracer_init(struct trace_array *tr) |
634 | { | |
635 | wakeup_dl = 1; | |
636 | wakeup_rt = 0; | |
637 | return __wakeup_tracer_init(tr); | |
638 | } | |
639 | ||
e309b41d | 640 | static void wakeup_tracer_reset(struct trace_array *tr) |
352ad25a | 641 | { |
613f04a0 SRRH |
642 | int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT; |
643 | int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE; | |
644 | ||
c76f0694 SR |
645 | stop_wakeup_tracer(tr); |
646 | /* make sure we put back any tasks we are tracing */ | |
647 | wakeup_reset(tr); | |
e9d25fe6 | 648 | |
2b6080f2 SR |
649 | set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag); |
650 | set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag); | |
4104d326 | 651 | ftrace_reset_array_ops(tr); |
352ad25a SR |
652 | } |
653 | ||
9036990d SR |
654 | static void wakeup_tracer_start(struct trace_array *tr) |
655 | { | |
656 | wakeup_reset(tr); | |
657 | tracer_enabled = 1; | |
9036990d SR |
658 | } |
659 | ||
660 | static void wakeup_tracer_stop(struct trace_array *tr) | |
661 | { | |
662 | tracer_enabled = 0; | |
352ad25a SR |
663 | } |
664 | ||
665 | static struct tracer wakeup_tracer __read_mostly = | |
666 | { | |
667 | .name = "wakeup", | |
668 | .init = wakeup_tracer_init, | |
669 | .reset = wakeup_tracer_reset, | |
9036990d SR |
670 | .start = wakeup_tracer_start, |
671 | .stop = wakeup_tracer_stop, | |
f43c738b | 672 | .print_max = true, |
7495a5be JO |
673 | .print_header = wakeup_print_header, |
674 | .print_line = wakeup_print_line, | |
675 | .flags = &tracer_flags, | |
676 | .set_flag = wakeup_set_flag, | |
328df475 | 677 | .flag_changed = wakeup_flag_changed, |
60a11774 SR |
678 | #ifdef CONFIG_FTRACE_SELFTEST |
679 | .selftest = trace_selftest_startup_wakeup, | |
680 | #endif | |
7495a5be JO |
681 | .open = wakeup_trace_open, |
682 | .close = wakeup_trace_close, | |
f43c738b | 683 | .use_max_tr = true, |
352ad25a SR |
684 | }; |
685 | ||
3244351c SR |
686 | static struct tracer wakeup_rt_tracer __read_mostly = |
687 | { | |
688 | .name = "wakeup_rt", | |
689 | .init = wakeup_rt_tracer_init, | |
690 | .reset = wakeup_tracer_reset, | |
691 | .start = wakeup_tracer_start, | |
692 | .stop = wakeup_tracer_stop, | |
6eaaa5d5 | 693 | .wait_pipe = poll_wait_pipe, |
f43c738b | 694 | .print_max = true, |
7495a5be JO |
695 | .print_header = wakeup_print_header, |
696 | .print_line = wakeup_print_line, | |
697 | .flags = &tracer_flags, | |
698 | .set_flag = wakeup_set_flag, | |
328df475 | 699 | .flag_changed = wakeup_flag_changed, |
3244351c SR |
700 | #ifdef CONFIG_FTRACE_SELFTEST |
701 | .selftest = trace_selftest_startup_wakeup, | |
702 | #endif | |
7495a5be JO |
703 | .open = wakeup_trace_open, |
704 | .close = wakeup_trace_close, | |
f43c738b | 705 | .use_max_tr = true, |
3244351c SR |
706 | }; |
707 | ||
af6ace76 DF |
708 | static struct tracer wakeup_dl_tracer __read_mostly = |
709 | { | |
710 | .name = "wakeup_dl", | |
711 | .init = wakeup_dl_tracer_init, | |
712 | .reset = wakeup_tracer_reset, | |
713 | .start = wakeup_tracer_start, | |
714 | .stop = wakeup_tracer_stop, | |
715 | .wait_pipe = poll_wait_pipe, | |
716 | .print_max = true, | |
717 | .print_header = wakeup_print_header, | |
718 | .print_line = wakeup_print_line, | |
719 | .flags = &tracer_flags, | |
720 | .set_flag = wakeup_set_flag, | |
721 | .flag_changed = wakeup_flag_changed, | |
722 | #ifdef CONFIG_FTRACE_SELFTEST | |
723 | .selftest = trace_selftest_startup_wakeup, | |
724 | #endif | |
725 | .open = wakeup_trace_open, | |
726 | .close = wakeup_trace_close, | |
727 | .use_max_tr = true, | |
728 | }; | |
729 | ||
352ad25a SR |
730 | __init static int init_wakeup_tracer(void) |
731 | { | |
732 | int ret; | |
733 | ||
734 | ret = register_tracer(&wakeup_tracer); | |
735 | if (ret) | |
736 | return ret; | |
737 | ||
3244351c SR |
738 | ret = register_tracer(&wakeup_rt_tracer); |
739 | if (ret) | |
740 | return ret; | |
741 | ||
af6ace76 DF |
742 | ret = register_tracer(&wakeup_dl_tracer); |
743 | if (ret) | |
744 | return ret; | |
745 | ||
352ad25a SR |
746 | return 0; |
747 | } | |
6f415672 | 748 | core_initcall(init_wakeup_tracer); |