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 SR |
132 | } |
133 | ||
134 | static struct ftrace_ops trace_ops __read_mostly = | |
135 | { | |
136 | .func = wakeup_tracer_call, | |
4740974a | 137 | .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE, |
7e18d8e7 | 138 | }; |
7e40798f | 139 | #endif /* CONFIG_FUNCTION_TRACER */ |
7495a5be | 140 | |
328df475 | 141 | static int register_wakeup_function(int graph, int set) |
7495a5be JO |
142 | { |
143 | int ret; | |
144 | ||
328df475 SRRH |
145 | /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */ |
146 | if (function_enabled || (!set && !(trace_flags & TRACE_ITER_FUNCTION))) | |
147 | return 0; | |
148 | ||
149 | if (graph) | |
7495a5be JO |
150 | ret = register_ftrace_graph(&wakeup_graph_return, |
151 | &wakeup_graph_entry); | |
328df475 SRRH |
152 | else |
153 | ret = register_ftrace_function(&trace_ops); | |
154 | ||
155 | if (!ret) | |
156 | function_enabled = true; | |
157 | ||
158 | return ret; | |
159 | } | |
160 | ||
161 | static void unregister_wakeup_function(int graph) | |
162 | { | |
163 | if (!function_enabled) | |
164 | return; | |
165 | ||
166 | if (graph) | |
167 | unregister_ftrace_graph(); | |
168 | else | |
169 | unregister_ftrace_function(&trace_ops); | |
170 | ||
171 | function_enabled = false; | |
172 | } | |
173 | ||
174 | static void wakeup_function_set(int set) | |
175 | { | |
176 | if (set) | |
177 | register_wakeup_function(is_graph(), 1); | |
178 | else | |
179 | unregister_wakeup_function(is_graph()); | |
180 | } | |
181 | ||
182 | static int wakeup_flag_changed(struct tracer *tracer, u32 mask, int set) | |
183 | { | |
184 | if (mask & TRACE_ITER_FUNCTION) | |
185 | wakeup_function_set(set); | |
186 | ||
187 | return trace_keep_overwrite(tracer, mask, set); | |
188 | } | |
189 | ||
190 | static int start_func_tracer(int graph) | |
191 | { | |
192 | int ret; | |
193 | ||
194 | ret = register_wakeup_function(graph, 0); | |
7495a5be JO |
195 | |
196 | if (!ret && tracing_is_enabled()) | |
197 | tracer_enabled = 1; | |
198 | else | |
199 | tracer_enabled = 0; | |
200 | ||
201 | return ret; | |
202 | } | |
203 | ||
204 | static void stop_func_tracer(int graph) | |
205 | { | |
206 | tracer_enabled = 0; | |
207 | ||
328df475 | 208 | unregister_wakeup_function(graph); |
7495a5be JO |
209 | } |
210 | ||
7495a5be JO |
211 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
212 | static int wakeup_set_flag(u32 old_flags, u32 bit, int set) | |
213 | { | |
214 | ||
215 | if (!(bit & TRACE_DISPLAY_GRAPH)) | |
216 | return -EINVAL; | |
217 | ||
218 | if (!(is_graph() ^ set)) | |
219 | return 0; | |
220 | ||
221 | stop_func_tracer(!set); | |
222 | ||
223 | wakeup_reset(wakeup_trace); | |
224 | tracing_max_latency = 0; | |
225 | ||
226 | return start_func_tracer(set); | |
227 | } | |
228 | ||
229 | static int wakeup_graph_entry(struct ftrace_graph_ent *trace) | |
230 | { | |
231 | struct trace_array *tr = wakeup_trace; | |
232 | struct trace_array_cpu *data; | |
233 | unsigned long flags; | |
542181d3 | 234 | int pc, ret = 0; |
7495a5be | 235 | |
542181d3 | 236 | if (!func_prolog_preempt_disable(tr, &data, &pc)) |
7495a5be JO |
237 | return 0; |
238 | ||
7495a5be JO |
239 | local_save_flags(flags); |
240 | ret = __trace_graph_entry(tr, trace, flags, pc); | |
7495a5be | 241 | atomic_dec(&data->disabled); |
7495a5be | 242 | preempt_enable_notrace(); |
542181d3 | 243 | |
7495a5be JO |
244 | return ret; |
245 | } | |
246 | ||
247 | static void wakeup_graph_return(struct ftrace_graph_ret *trace) | |
248 | { | |
249 | struct trace_array *tr = wakeup_trace; | |
250 | struct trace_array_cpu *data; | |
251 | unsigned long flags; | |
542181d3 | 252 | int pc; |
7495a5be | 253 | |
542181d3 | 254 | if (!func_prolog_preempt_disable(tr, &data, &pc)) |
7495a5be JO |
255 | return; |
256 | ||
7495a5be JO |
257 | local_save_flags(flags); |
258 | __trace_graph_return(tr, trace, flags, pc); | |
7495a5be JO |
259 | atomic_dec(&data->disabled); |
260 | ||
7495a5be JO |
261 | preempt_enable_notrace(); |
262 | return; | |
263 | } | |
264 | ||
265 | static void wakeup_trace_open(struct trace_iterator *iter) | |
266 | { | |
267 | if (is_graph()) | |
268 | graph_trace_open(iter); | |
269 | } | |
270 | ||
271 | static void wakeup_trace_close(struct trace_iterator *iter) | |
272 | { | |
273 | if (iter->private) | |
274 | graph_trace_close(iter); | |
275 | } | |
276 | ||
321e68b0 JO |
277 | #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_PROC | \ |
278 | TRACE_GRAPH_PRINT_ABS_TIME | \ | |
279 | TRACE_GRAPH_PRINT_DURATION) | |
7495a5be JO |
280 | |
281 | static enum print_line_t wakeup_print_line(struct trace_iterator *iter) | |
282 | { | |
283 | /* | |
284 | * In graph mode call the graph tracer output function, | |
285 | * otherwise go with the TRACE_FN event handler | |
286 | */ | |
287 | if (is_graph()) | |
288 | return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS); | |
289 | ||
290 | return TRACE_TYPE_UNHANDLED; | |
291 | } | |
292 | ||
293 | static void wakeup_print_header(struct seq_file *s) | |
294 | { | |
295 | if (is_graph()) | |
296 | print_graph_headers_flags(s, GRAPH_TRACER_FLAGS); | |
297 | else | |
298 | trace_default_header(s); | |
299 | } | |
300 | ||
301 | static void | |
302 | __trace_function(struct trace_array *tr, | |
303 | unsigned long ip, unsigned long parent_ip, | |
304 | unsigned long flags, int pc) | |
305 | { | |
306 | if (is_graph()) | |
307 | trace_graph_function(tr, ip, parent_ip, flags, pc); | |
308 | else | |
309 | trace_function(tr, ip, parent_ip, flags, pc); | |
310 | } | |
311 | #else | |
312 | #define __trace_function trace_function | |
313 | ||
314 | static int wakeup_set_flag(u32 old_flags, u32 bit, int set) | |
315 | { | |
316 | return -EINVAL; | |
317 | } | |
318 | ||
319 | static int wakeup_graph_entry(struct ftrace_graph_ent *trace) | |
320 | { | |
321 | return -1; | |
322 | } | |
323 | ||
324 | static enum print_line_t wakeup_print_line(struct trace_iterator *iter) | |
325 | { | |
326 | return TRACE_TYPE_UNHANDLED; | |
327 | } | |
328 | ||
329 | static void wakeup_graph_return(struct ftrace_graph_ret *trace) { } | |
7495a5be JO |
330 | static void wakeup_trace_open(struct trace_iterator *iter) { } |
331 | static void wakeup_trace_close(struct trace_iterator *iter) { } | |
7e9a49ef JO |
332 | |
333 | #ifdef CONFIG_FUNCTION_TRACER | |
334 | static void wakeup_print_header(struct seq_file *s) | |
335 | { | |
336 | trace_default_header(s); | |
337 | } | |
338 | #else | |
339 | static void wakeup_print_header(struct seq_file *s) | |
340 | { | |
341 | trace_latency_header(s); | |
342 | } | |
343 | #endif /* CONFIG_FUNCTION_TRACER */ | |
7495a5be JO |
344 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
345 | ||
352ad25a SR |
346 | /* |
347 | * Should this new latency be reported/recorded? | |
348 | */ | |
e309b41d | 349 | static int report_latency(cycle_t delta) |
352ad25a SR |
350 | { |
351 | if (tracing_thresh) { | |
352 | if (delta < tracing_thresh) | |
353 | return 0; | |
354 | } else { | |
355 | if (delta <= tracing_max_latency) | |
356 | return 0; | |
357 | } | |
358 | return 1; | |
359 | } | |
360 | ||
38516ab5 SR |
361 | static void |
362 | probe_wakeup_migrate_task(void *ignore, struct task_struct *task, int cpu) | |
478142c3 SR |
363 | { |
364 | if (task != wakeup_task) | |
365 | return; | |
366 | ||
367 | wakeup_current_cpu = cpu; | |
368 | } | |
369 | ||
5b82a1b0 | 370 | static void notrace |
38516ab5 SR |
371 | probe_wakeup_sched_switch(void *ignore, |
372 | struct task_struct *prev, struct task_struct *next) | |
352ad25a | 373 | { |
352ad25a SR |
374 | struct trace_array_cpu *data; |
375 | cycle_t T0, T1, delta; | |
376 | unsigned long flags; | |
377 | long disabled; | |
378 | int cpu; | |
38697053 | 379 | int pc; |
352ad25a | 380 | |
b07c3f19 MD |
381 | tracing_record_cmdline(prev); |
382 | ||
352ad25a SR |
383 | if (unlikely(!tracer_enabled)) |
384 | return; | |
385 | ||
386 | /* | |
387 | * When we start a new trace, we set wakeup_task to NULL | |
388 | * and then set tracer_enabled = 1. We want to make sure | |
389 | * that another CPU does not see the tracer_enabled = 1 | |
390 | * and the wakeup_task with an older task, that might | |
391 | * actually be the same as next. | |
392 | */ | |
393 | smp_rmb(); | |
394 | ||
395 | if (next != wakeup_task) | |
396 | return; | |
397 | ||
38697053 SR |
398 | pc = preempt_count(); |
399 | ||
352ad25a SR |
400 | /* disable local data, not wakeup_cpu data */ |
401 | cpu = raw_smp_processor_id(); | |
12883efb | 402 | disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); |
352ad25a SR |
403 | if (likely(disabled != 1)) |
404 | goto out; | |
405 | ||
e59494f4 | 406 | local_irq_save(flags); |
0199c4e6 | 407 | arch_spin_lock(&wakeup_lock); |
352ad25a SR |
408 | |
409 | /* We could race with grabbing wakeup_lock */ | |
410 | if (unlikely(!tracer_enabled || next != wakeup_task)) | |
411 | goto out_unlock; | |
412 | ||
9be24414 | 413 | /* The task we are waiting for is waking up */ |
12883efb | 414 | data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu); |
9be24414 | 415 | |
7495a5be | 416 | __trace_function(wakeup_trace, CALLER_ADDR0, CALLER_ADDR1, flags, pc); |
7be42151 | 417 | tracing_sched_switch_trace(wakeup_trace, prev, next, flags, pc); |
352ad25a | 418 | |
352ad25a | 419 | T0 = data->preempt_timestamp; |
750ed1a4 | 420 | T1 = ftrace_now(cpu); |
352ad25a SR |
421 | delta = T1-T0; |
422 | ||
423 | if (!report_latency(delta)) | |
424 | goto out_unlock; | |
425 | ||
b5130b1e CE |
426 | if (likely(!is_tracing_stopped())) { |
427 | tracing_max_latency = delta; | |
428 | update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu); | |
429 | } | |
352ad25a | 430 | |
352ad25a | 431 | out_unlock: |
b07c3f19 | 432 | __wakeup_reset(wakeup_trace); |
0199c4e6 | 433 | arch_spin_unlock(&wakeup_lock); |
e59494f4 | 434 | local_irq_restore(flags); |
352ad25a | 435 | out: |
12883efb | 436 | atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); |
5b82a1b0 MD |
437 | } |
438 | ||
e309b41d | 439 | static void __wakeup_reset(struct trace_array *tr) |
352ad25a | 440 | { |
352ad25a SR |
441 | wakeup_cpu = -1; |
442 | wakeup_prio = -1; | |
af6ace76 | 443 | tracing_dl = 0; |
352ad25a SR |
444 | |
445 | if (wakeup_task) | |
446 | put_task_struct(wakeup_task); | |
447 | ||
448 | wakeup_task = NULL; | |
449 | } | |
450 | ||
e309b41d | 451 | static void wakeup_reset(struct trace_array *tr) |
352ad25a SR |
452 | { |
453 | unsigned long flags; | |
454 | ||
12883efb | 455 | tracing_reset_online_cpus(&tr->trace_buffer); |
2f26ebd5 | 456 | |
e59494f4 | 457 | local_irq_save(flags); |
0199c4e6 | 458 | arch_spin_lock(&wakeup_lock); |
352ad25a | 459 | __wakeup_reset(tr); |
0199c4e6 | 460 | arch_spin_unlock(&wakeup_lock); |
e59494f4 | 461 | local_irq_restore(flags); |
352ad25a SR |
462 | } |
463 | ||
e309b41d | 464 | static void |
38516ab5 | 465 | probe_wakeup(void *ignore, struct task_struct *p, int success) |
352ad25a | 466 | { |
f8ec1062 | 467 | struct trace_array_cpu *data; |
352ad25a SR |
468 | int cpu = smp_processor_id(); |
469 | unsigned long flags; | |
470 | long disabled; | |
38697053 | 471 | int pc; |
352ad25a | 472 | |
b07c3f19 MD |
473 | if (likely(!tracer_enabled)) |
474 | return; | |
475 | ||
476 | tracing_record_cmdline(p); | |
477 | tracing_record_cmdline(current); | |
478 | ||
af6ace76 DF |
479 | /* |
480 | * Semantic is like this: | |
481 | * - wakeup tracer handles all tasks in the system, independently | |
482 | * from their scheduling class; | |
483 | * - wakeup_rt tracer handles tasks belonging to sched_dl and | |
484 | * sched_rt class; | |
485 | * - wakeup_dl handles tasks belonging to sched_dl class only. | |
486 | */ | |
487 | if (tracing_dl || (wakeup_dl && !dl_task(p)) || | |
488 | (wakeup_rt && !dl_task(p) && !rt_task(p)) || | |
489 | (!dl_task(p) && (p->prio >= wakeup_prio || p->prio >= current->prio))) | |
352ad25a SR |
490 | return; |
491 | ||
38697053 | 492 | pc = preempt_count(); |
12883efb | 493 | disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); |
352ad25a SR |
494 | if (unlikely(disabled != 1)) |
495 | goto out; | |
496 | ||
497 | /* interrupts should be off from try_to_wake_up */ | |
0199c4e6 | 498 | arch_spin_lock(&wakeup_lock); |
352ad25a SR |
499 | |
500 | /* check for races. */ | |
af6ace76 DF |
501 | if (!tracer_enabled || tracing_dl || |
502 | (!dl_task(p) && p->prio >= wakeup_prio)) | |
352ad25a SR |
503 | goto out_locked; |
504 | ||
505 | /* reset the trace */ | |
b07c3f19 | 506 | __wakeup_reset(wakeup_trace); |
352ad25a SR |
507 | |
508 | wakeup_cpu = task_cpu(p); | |
478142c3 | 509 | wakeup_current_cpu = wakeup_cpu; |
352ad25a SR |
510 | wakeup_prio = p->prio; |
511 | ||
af6ace76 DF |
512 | /* |
513 | * Once you start tracing a -deadline task, don't bother tracing | |
514 | * another task until the first one wakes up. | |
515 | */ | |
516 | if (dl_task(p)) | |
517 | tracing_dl = 1; | |
518 | else | |
519 | tracing_dl = 0; | |
520 | ||
352ad25a SR |
521 | wakeup_task = p; |
522 | get_task_struct(wakeup_task); | |
523 | ||
524 | local_save_flags(flags); | |
525 | ||
12883efb | 526 | data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu); |
f8ec1062 | 527 | data->preempt_timestamp = ftrace_now(cpu); |
7be42151 | 528 | tracing_sched_wakeup_trace(wakeup_trace, p, current, flags, pc); |
301fd748 SR |
529 | |
530 | /* | |
531 | * We must be careful in using CALLER_ADDR2. But since wake_up | |
532 | * is not called by an assembly function (where as schedule is) | |
533 | * it should be safe to use it here. | |
534 | */ | |
7495a5be | 535 | __trace_function(wakeup_trace, CALLER_ADDR1, CALLER_ADDR2, flags, pc); |
352ad25a SR |
536 | |
537 | out_locked: | |
0199c4e6 | 538 | arch_spin_unlock(&wakeup_lock); |
352ad25a | 539 | out: |
12883efb | 540 | atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); |
352ad25a SR |
541 | } |
542 | ||
e309b41d | 543 | static void start_wakeup_tracer(struct trace_array *tr) |
352ad25a | 544 | { |
5b82a1b0 MD |
545 | int ret; |
546 | ||
38516ab5 | 547 | ret = register_trace_sched_wakeup(probe_wakeup, NULL); |
5b82a1b0 | 548 | if (ret) { |
b07c3f19 | 549 | pr_info("wakeup trace: Couldn't activate tracepoint" |
5b82a1b0 MD |
550 | " probe to kernel_sched_wakeup\n"); |
551 | return; | |
552 | } | |
553 | ||
38516ab5 | 554 | ret = register_trace_sched_wakeup_new(probe_wakeup, NULL); |
5b82a1b0 | 555 | if (ret) { |
b07c3f19 | 556 | pr_info("wakeup trace: Couldn't activate tracepoint" |
5b82a1b0 MD |
557 | " probe to kernel_sched_wakeup_new\n"); |
558 | goto fail_deprobe; | |
559 | } | |
560 | ||
38516ab5 | 561 | ret = register_trace_sched_switch(probe_wakeup_sched_switch, NULL); |
5b82a1b0 | 562 | if (ret) { |
b07c3f19 | 563 | pr_info("sched trace: Couldn't activate tracepoint" |
73d8b8bc | 564 | " probe to kernel_sched_switch\n"); |
5b82a1b0 MD |
565 | goto fail_deprobe_wake_new; |
566 | } | |
567 | ||
38516ab5 | 568 | ret = register_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL); |
478142c3 SR |
569 | if (ret) { |
570 | pr_info("wakeup trace: Couldn't activate tracepoint" | |
571 | " probe to kernel_sched_migrate_task\n"); | |
572 | return; | |
573 | } | |
574 | ||
352ad25a SR |
575 | wakeup_reset(tr); |
576 | ||
577 | /* | |
578 | * Don't let the tracer_enabled = 1 show up before | |
579 | * the wakeup_task is reset. This may be overkill since | |
580 | * wakeup_reset does a spin_unlock after setting the | |
581 | * wakeup_task to NULL, but I want to be safe. | |
582 | * This is a slow path anyway. | |
583 | */ | |
584 | smp_wmb(); | |
585 | ||
7495a5be JO |
586 | if (start_func_tracer(is_graph())) |
587 | printk(KERN_ERR "failed to start wakeup tracer\n"); | |
ad591240 | 588 | |
352ad25a | 589 | return; |
5b82a1b0 | 590 | fail_deprobe_wake_new: |
38516ab5 | 591 | unregister_trace_sched_wakeup_new(probe_wakeup, NULL); |
5b82a1b0 | 592 | fail_deprobe: |
38516ab5 | 593 | unregister_trace_sched_wakeup(probe_wakeup, NULL); |
352ad25a SR |
594 | } |
595 | ||
e309b41d | 596 | static void stop_wakeup_tracer(struct trace_array *tr) |
352ad25a SR |
597 | { |
598 | tracer_enabled = 0; | |
7495a5be | 599 | stop_func_tracer(is_graph()); |
38516ab5 SR |
600 | unregister_trace_sched_switch(probe_wakeup_sched_switch, NULL); |
601 | unregister_trace_sched_wakeup_new(probe_wakeup, NULL); | |
602 | unregister_trace_sched_wakeup(probe_wakeup, NULL); | |
603 | unregister_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL); | |
352ad25a SR |
604 | } |
605 | ||
3244351c | 606 | static int __wakeup_tracer_init(struct trace_array *tr) |
352ad25a | 607 | { |
613f04a0 SRRH |
608 | save_flags = trace_flags; |
609 | ||
610 | /* non overwrite screws up the latency tracers */ | |
2b6080f2 SR |
611 | set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1); |
612 | set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1); | |
e9d25fe6 | 613 | |
745b1626 | 614 | tracing_max_latency = 0; |
352ad25a | 615 | wakeup_trace = tr; |
c76f0694 | 616 | start_wakeup_tracer(tr); |
1c80025a | 617 | return 0; |
352ad25a SR |
618 | } |
619 | ||
3244351c SR |
620 | static int wakeup_tracer_init(struct trace_array *tr) |
621 | { | |
af6ace76 | 622 | wakeup_dl = 0; |
3244351c SR |
623 | wakeup_rt = 0; |
624 | return __wakeup_tracer_init(tr); | |
625 | } | |
626 | ||
627 | static int wakeup_rt_tracer_init(struct trace_array *tr) | |
628 | { | |
af6ace76 | 629 | wakeup_dl = 0; |
3244351c SR |
630 | wakeup_rt = 1; |
631 | return __wakeup_tracer_init(tr); | |
632 | } | |
633 | ||
af6ace76 DF |
634 | static int wakeup_dl_tracer_init(struct trace_array *tr) |
635 | { | |
636 | wakeup_dl = 1; | |
637 | wakeup_rt = 0; | |
638 | return __wakeup_tracer_init(tr); | |
639 | } | |
640 | ||
e309b41d | 641 | static void wakeup_tracer_reset(struct trace_array *tr) |
352ad25a | 642 | { |
613f04a0 SRRH |
643 | int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT; |
644 | int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE; | |
645 | ||
c76f0694 SR |
646 | stop_wakeup_tracer(tr); |
647 | /* make sure we put back any tasks we are tracing */ | |
648 | wakeup_reset(tr); | |
e9d25fe6 | 649 | |
2b6080f2 SR |
650 | set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag); |
651 | set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag); | |
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); |