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); | |
6d9b3fa5 | 221 | tr->max_latency = 0; |
7495a5be | 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 | */ | |
6d9b3fa5 | 347 | static int report_latency(struct trace_array *tr, cycle_t delta) |
352ad25a SR |
348 | { |
349 | if (tracing_thresh) { | |
350 | if (delta < tracing_thresh) | |
351 | return 0; | |
352 | } else { | |
6d9b3fa5 | 353 | if (delta <= tr->max_latency) |
352ad25a SR |
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 | ||
243f7610 SRRH |
368 | static void |
369 | tracing_sched_switch_trace(struct trace_array *tr, | |
370 | struct task_struct *prev, | |
371 | struct task_struct *next, | |
372 | unsigned long flags, int pc) | |
373 | { | |
374 | struct ftrace_event_call *call = &event_context_switch; | |
375 | struct ring_buffer *buffer = tr->trace_buffer.buffer; | |
376 | struct ring_buffer_event *event; | |
377 | struct ctx_switch_entry *entry; | |
378 | ||
379 | event = trace_buffer_lock_reserve(buffer, TRACE_CTX, | |
380 | sizeof(*entry), flags, pc); | |
381 | if (!event) | |
382 | return; | |
383 | entry = ring_buffer_event_data(event); | |
384 | entry->prev_pid = prev->pid; | |
385 | entry->prev_prio = prev->prio; | |
386 | entry->prev_state = prev->state; | |
387 | entry->next_pid = next->pid; | |
388 | entry->next_prio = next->prio; | |
389 | entry->next_state = next->state; | |
390 | entry->next_cpu = task_cpu(next); | |
391 | ||
392 | if (!call_filter_check_discard(call, entry, buffer, event)) | |
393 | trace_buffer_unlock_commit(buffer, event, flags, pc); | |
394 | } | |
395 | ||
396 | static void | |
397 | tracing_sched_wakeup_trace(struct trace_array *tr, | |
398 | struct task_struct *wakee, | |
399 | struct task_struct *curr, | |
400 | unsigned long flags, int pc) | |
401 | { | |
402 | struct ftrace_event_call *call = &event_wakeup; | |
403 | struct ring_buffer_event *event; | |
404 | struct ctx_switch_entry *entry; | |
405 | struct ring_buffer *buffer = tr->trace_buffer.buffer; | |
406 | ||
407 | event = trace_buffer_lock_reserve(buffer, TRACE_WAKE, | |
408 | sizeof(*entry), flags, pc); | |
409 | if (!event) | |
410 | return; | |
411 | entry = ring_buffer_event_data(event); | |
412 | entry->prev_pid = curr->pid; | |
413 | entry->prev_prio = curr->prio; | |
414 | entry->prev_state = curr->state; | |
415 | entry->next_pid = wakee->pid; | |
416 | entry->next_prio = wakee->prio; | |
417 | entry->next_state = wakee->state; | |
418 | entry->next_cpu = task_cpu(wakee); | |
419 | ||
420 | if (!call_filter_check_discard(call, entry, buffer, event)) | |
421 | trace_buffer_unlock_commit(buffer, event, flags, pc); | |
422 | } | |
423 | ||
5b82a1b0 | 424 | static void notrace |
38516ab5 SR |
425 | probe_wakeup_sched_switch(void *ignore, |
426 | struct task_struct *prev, struct task_struct *next) | |
352ad25a | 427 | { |
352ad25a SR |
428 | struct trace_array_cpu *data; |
429 | cycle_t T0, T1, delta; | |
430 | unsigned long flags; | |
431 | long disabled; | |
432 | int cpu; | |
38697053 | 433 | int pc; |
352ad25a | 434 | |
b07c3f19 MD |
435 | tracing_record_cmdline(prev); |
436 | ||
352ad25a SR |
437 | if (unlikely(!tracer_enabled)) |
438 | return; | |
439 | ||
440 | /* | |
441 | * When we start a new trace, we set wakeup_task to NULL | |
442 | * and then set tracer_enabled = 1. We want to make sure | |
443 | * that another CPU does not see the tracer_enabled = 1 | |
444 | * and the wakeup_task with an older task, that might | |
445 | * actually be the same as next. | |
446 | */ | |
447 | smp_rmb(); | |
448 | ||
449 | if (next != wakeup_task) | |
450 | return; | |
451 | ||
38697053 SR |
452 | pc = preempt_count(); |
453 | ||
352ad25a SR |
454 | /* disable local data, not wakeup_cpu data */ |
455 | cpu = raw_smp_processor_id(); | |
12883efb | 456 | disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); |
352ad25a SR |
457 | if (likely(disabled != 1)) |
458 | goto out; | |
459 | ||
e59494f4 | 460 | local_irq_save(flags); |
0199c4e6 | 461 | arch_spin_lock(&wakeup_lock); |
352ad25a SR |
462 | |
463 | /* We could race with grabbing wakeup_lock */ | |
464 | if (unlikely(!tracer_enabled || next != wakeup_task)) | |
465 | goto out_unlock; | |
466 | ||
9be24414 | 467 | /* The task we are waiting for is waking up */ |
12883efb | 468 | data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu); |
9be24414 | 469 | |
7495a5be | 470 | __trace_function(wakeup_trace, CALLER_ADDR0, CALLER_ADDR1, flags, pc); |
7be42151 | 471 | tracing_sched_switch_trace(wakeup_trace, prev, next, flags, pc); |
352ad25a | 472 | |
352ad25a | 473 | T0 = data->preempt_timestamp; |
750ed1a4 | 474 | T1 = ftrace_now(cpu); |
352ad25a SR |
475 | delta = T1-T0; |
476 | ||
6d9b3fa5 | 477 | if (!report_latency(wakeup_trace, delta)) |
352ad25a SR |
478 | goto out_unlock; |
479 | ||
b5130b1e | 480 | if (likely(!is_tracing_stopped())) { |
6d9b3fa5 | 481 | wakeup_trace->max_latency = delta; |
b5130b1e CE |
482 | update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu); |
483 | } | |
352ad25a | 484 | |
352ad25a | 485 | out_unlock: |
b07c3f19 | 486 | __wakeup_reset(wakeup_trace); |
0199c4e6 | 487 | arch_spin_unlock(&wakeup_lock); |
e59494f4 | 488 | local_irq_restore(flags); |
352ad25a | 489 | out: |
12883efb | 490 | atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); |
5b82a1b0 MD |
491 | } |
492 | ||
e309b41d | 493 | static void __wakeup_reset(struct trace_array *tr) |
352ad25a | 494 | { |
352ad25a SR |
495 | wakeup_cpu = -1; |
496 | wakeup_prio = -1; | |
af6ace76 | 497 | tracing_dl = 0; |
352ad25a SR |
498 | |
499 | if (wakeup_task) | |
500 | put_task_struct(wakeup_task); | |
501 | ||
502 | wakeup_task = NULL; | |
503 | } | |
504 | ||
e309b41d | 505 | static void wakeup_reset(struct trace_array *tr) |
352ad25a SR |
506 | { |
507 | unsigned long flags; | |
508 | ||
12883efb | 509 | tracing_reset_online_cpus(&tr->trace_buffer); |
2f26ebd5 | 510 | |
e59494f4 | 511 | local_irq_save(flags); |
0199c4e6 | 512 | arch_spin_lock(&wakeup_lock); |
352ad25a | 513 | __wakeup_reset(tr); |
0199c4e6 | 514 | arch_spin_unlock(&wakeup_lock); |
e59494f4 | 515 | local_irq_restore(flags); |
352ad25a SR |
516 | } |
517 | ||
e309b41d | 518 | static void |
38516ab5 | 519 | probe_wakeup(void *ignore, struct task_struct *p, int success) |
352ad25a | 520 | { |
f8ec1062 | 521 | struct trace_array_cpu *data; |
352ad25a SR |
522 | int cpu = smp_processor_id(); |
523 | unsigned long flags; | |
524 | long disabled; | |
38697053 | 525 | int pc; |
352ad25a | 526 | |
b07c3f19 MD |
527 | if (likely(!tracer_enabled)) |
528 | return; | |
529 | ||
530 | tracing_record_cmdline(p); | |
531 | tracing_record_cmdline(current); | |
532 | ||
af6ace76 DF |
533 | /* |
534 | * Semantic is like this: | |
535 | * - wakeup tracer handles all tasks in the system, independently | |
536 | * from their scheduling class; | |
537 | * - wakeup_rt tracer handles tasks belonging to sched_dl and | |
538 | * sched_rt class; | |
539 | * - wakeup_dl handles tasks belonging to sched_dl class only. | |
540 | */ | |
541 | if (tracing_dl || (wakeup_dl && !dl_task(p)) || | |
542 | (wakeup_rt && !dl_task(p) && !rt_task(p)) || | |
543 | (!dl_task(p) && (p->prio >= wakeup_prio || p->prio >= current->prio))) | |
352ad25a SR |
544 | return; |
545 | ||
38697053 | 546 | pc = preempt_count(); |
12883efb | 547 | disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); |
352ad25a SR |
548 | if (unlikely(disabled != 1)) |
549 | goto out; | |
550 | ||
551 | /* interrupts should be off from try_to_wake_up */ | |
0199c4e6 | 552 | arch_spin_lock(&wakeup_lock); |
352ad25a SR |
553 | |
554 | /* check for races. */ | |
af6ace76 DF |
555 | if (!tracer_enabled || tracing_dl || |
556 | (!dl_task(p) && p->prio >= wakeup_prio)) | |
352ad25a SR |
557 | goto out_locked; |
558 | ||
559 | /* reset the trace */ | |
b07c3f19 | 560 | __wakeup_reset(wakeup_trace); |
352ad25a SR |
561 | |
562 | wakeup_cpu = task_cpu(p); | |
478142c3 | 563 | wakeup_current_cpu = wakeup_cpu; |
352ad25a SR |
564 | wakeup_prio = p->prio; |
565 | ||
af6ace76 DF |
566 | /* |
567 | * Once you start tracing a -deadline task, don't bother tracing | |
568 | * another task until the first one wakes up. | |
569 | */ | |
570 | if (dl_task(p)) | |
571 | tracing_dl = 1; | |
572 | else | |
573 | tracing_dl = 0; | |
574 | ||
352ad25a SR |
575 | wakeup_task = p; |
576 | get_task_struct(wakeup_task); | |
577 | ||
578 | local_save_flags(flags); | |
579 | ||
12883efb | 580 | data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu); |
f8ec1062 | 581 | data->preempt_timestamp = ftrace_now(cpu); |
7be42151 | 582 | tracing_sched_wakeup_trace(wakeup_trace, p, current, flags, pc); |
301fd748 SR |
583 | |
584 | /* | |
585 | * We must be careful in using CALLER_ADDR2. But since wake_up | |
586 | * is not called by an assembly function (where as schedule is) | |
587 | * it should be safe to use it here. | |
588 | */ | |
7495a5be | 589 | __trace_function(wakeup_trace, CALLER_ADDR1, CALLER_ADDR2, flags, pc); |
352ad25a SR |
590 | |
591 | out_locked: | |
0199c4e6 | 592 | arch_spin_unlock(&wakeup_lock); |
352ad25a | 593 | out: |
12883efb | 594 | atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); |
352ad25a SR |
595 | } |
596 | ||
e309b41d | 597 | static void start_wakeup_tracer(struct trace_array *tr) |
352ad25a | 598 | { |
5b82a1b0 MD |
599 | int ret; |
600 | ||
38516ab5 | 601 | ret = register_trace_sched_wakeup(probe_wakeup, NULL); |
5b82a1b0 | 602 | if (ret) { |
b07c3f19 | 603 | pr_info("wakeup trace: Couldn't activate tracepoint" |
5b82a1b0 MD |
604 | " probe to kernel_sched_wakeup\n"); |
605 | return; | |
606 | } | |
607 | ||
38516ab5 | 608 | ret = register_trace_sched_wakeup_new(probe_wakeup, NULL); |
5b82a1b0 | 609 | if (ret) { |
b07c3f19 | 610 | pr_info("wakeup trace: Couldn't activate tracepoint" |
5b82a1b0 MD |
611 | " probe to kernel_sched_wakeup_new\n"); |
612 | goto fail_deprobe; | |
613 | } | |
614 | ||
38516ab5 | 615 | ret = register_trace_sched_switch(probe_wakeup_sched_switch, NULL); |
5b82a1b0 | 616 | if (ret) { |
b07c3f19 | 617 | pr_info("sched trace: Couldn't activate tracepoint" |
73d8b8bc | 618 | " probe to kernel_sched_switch\n"); |
5b82a1b0 MD |
619 | goto fail_deprobe_wake_new; |
620 | } | |
621 | ||
38516ab5 | 622 | ret = register_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL); |
478142c3 SR |
623 | if (ret) { |
624 | pr_info("wakeup trace: Couldn't activate tracepoint" | |
625 | " probe to kernel_sched_migrate_task\n"); | |
626 | return; | |
627 | } | |
628 | ||
352ad25a SR |
629 | wakeup_reset(tr); |
630 | ||
631 | /* | |
632 | * Don't let the tracer_enabled = 1 show up before | |
633 | * the wakeup_task is reset. This may be overkill since | |
634 | * wakeup_reset does a spin_unlock after setting the | |
635 | * wakeup_task to NULL, but I want to be safe. | |
636 | * This is a slow path anyway. | |
637 | */ | |
638 | smp_wmb(); | |
639 | ||
4104d326 | 640 | if (start_func_tracer(tr, is_graph())) |
7495a5be | 641 | printk(KERN_ERR "failed to start wakeup tracer\n"); |
ad591240 | 642 | |
352ad25a | 643 | return; |
5b82a1b0 | 644 | fail_deprobe_wake_new: |
38516ab5 | 645 | unregister_trace_sched_wakeup_new(probe_wakeup, NULL); |
5b82a1b0 | 646 | fail_deprobe: |
38516ab5 | 647 | unregister_trace_sched_wakeup(probe_wakeup, NULL); |
352ad25a SR |
648 | } |
649 | ||
e309b41d | 650 | static void stop_wakeup_tracer(struct trace_array *tr) |
352ad25a SR |
651 | { |
652 | tracer_enabled = 0; | |
4104d326 | 653 | stop_func_tracer(tr, is_graph()); |
38516ab5 SR |
654 | unregister_trace_sched_switch(probe_wakeup_sched_switch, NULL); |
655 | unregister_trace_sched_wakeup_new(probe_wakeup, NULL); | |
656 | unregister_trace_sched_wakeup(probe_wakeup, NULL); | |
657 | unregister_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL); | |
352ad25a SR |
658 | } |
659 | ||
65daaca7 SRRH |
660 | static bool wakeup_busy; |
661 | ||
3244351c | 662 | static int __wakeup_tracer_init(struct trace_array *tr) |
352ad25a | 663 | { |
613f04a0 SRRH |
664 | save_flags = trace_flags; |
665 | ||
666 | /* non overwrite screws up the latency tracers */ | |
2b6080f2 SR |
667 | set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1); |
668 | set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1); | |
e9d25fe6 | 669 | |
6d9b3fa5 | 670 | tr->max_latency = 0; |
352ad25a | 671 | wakeup_trace = tr; |
4104d326 | 672 | ftrace_init_array_ops(tr, wakeup_tracer_call); |
c76f0694 | 673 | start_wakeup_tracer(tr); |
65daaca7 SRRH |
674 | |
675 | wakeup_busy = true; | |
1c80025a | 676 | return 0; |
352ad25a SR |
677 | } |
678 | ||
3244351c SR |
679 | static int wakeup_tracer_init(struct trace_array *tr) |
680 | { | |
65daaca7 SRRH |
681 | if (wakeup_busy) |
682 | return -EBUSY; | |
683 | ||
af6ace76 | 684 | wakeup_dl = 0; |
3244351c SR |
685 | wakeup_rt = 0; |
686 | return __wakeup_tracer_init(tr); | |
687 | } | |
688 | ||
689 | static int wakeup_rt_tracer_init(struct trace_array *tr) | |
690 | { | |
65daaca7 SRRH |
691 | if (wakeup_busy) |
692 | return -EBUSY; | |
693 | ||
af6ace76 | 694 | wakeup_dl = 0; |
3244351c SR |
695 | wakeup_rt = 1; |
696 | return __wakeup_tracer_init(tr); | |
697 | } | |
698 | ||
af6ace76 DF |
699 | static int wakeup_dl_tracer_init(struct trace_array *tr) |
700 | { | |
65daaca7 SRRH |
701 | if (wakeup_busy) |
702 | return -EBUSY; | |
703 | ||
af6ace76 DF |
704 | wakeup_dl = 1; |
705 | wakeup_rt = 0; | |
706 | return __wakeup_tracer_init(tr); | |
707 | } | |
708 | ||
e309b41d | 709 | static void wakeup_tracer_reset(struct trace_array *tr) |
352ad25a | 710 | { |
613f04a0 SRRH |
711 | int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT; |
712 | int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE; | |
713 | ||
c76f0694 SR |
714 | stop_wakeup_tracer(tr); |
715 | /* make sure we put back any tasks we are tracing */ | |
716 | wakeup_reset(tr); | |
e9d25fe6 | 717 | |
2b6080f2 SR |
718 | set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag); |
719 | set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag); | |
4104d326 | 720 | ftrace_reset_array_ops(tr); |
65daaca7 | 721 | wakeup_busy = false; |
352ad25a SR |
722 | } |
723 | ||
9036990d SR |
724 | static void wakeup_tracer_start(struct trace_array *tr) |
725 | { | |
726 | wakeup_reset(tr); | |
727 | tracer_enabled = 1; | |
9036990d SR |
728 | } |
729 | ||
730 | static void wakeup_tracer_stop(struct trace_array *tr) | |
731 | { | |
732 | tracer_enabled = 0; | |
352ad25a SR |
733 | } |
734 | ||
735 | static struct tracer wakeup_tracer __read_mostly = | |
736 | { | |
737 | .name = "wakeup", | |
738 | .init = wakeup_tracer_init, | |
739 | .reset = wakeup_tracer_reset, | |
9036990d SR |
740 | .start = wakeup_tracer_start, |
741 | .stop = wakeup_tracer_stop, | |
f43c738b | 742 | .print_max = true, |
7495a5be JO |
743 | .print_header = wakeup_print_header, |
744 | .print_line = wakeup_print_line, | |
745 | .flags = &tracer_flags, | |
746 | .set_flag = wakeup_set_flag, | |
328df475 | 747 | .flag_changed = wakeup_flag_changed, |
60a11774 SR |
748 | #ifdef CONFIG_FTRACE_SELFTEST |
749 | .selftest = trace_selftest_startup_wakeup, | |
750 | #endif | |
7495a5be JO |
751 | .open = wakeup_trace_open, |
752 | .close = wakeup_trace_close, | |
65daaca7 | 753 | .allow_instances = true, |
f43c738b | 754 | .use_max_tr = true, |
352ad25a SR |
755 | }; |
756 | ||
3244351c SR |
757 | static struct tracer wakeup_rt_tracer __read_mostly = |
758 | { | |
759 | .name = "wakeup_rt", | |
760 | .init = wakeup_rt_tracer_init, | |
761 | .reset = wakeup_tracer_reset, | |
762 | .start = wakeup_tracer_start, | |
763 | .stop = wakeup_tracer_stop, | |
f43c738b | 764 | .print_max = true, |
7495a5be JO |
765 | .print_header = wakeup_print_header, |
766 | .print_line = wakeup_print_line, | |
767 | .flags = &tracer_flags, | |
768 | .set_flag = wakeup_set_flag, | |
328df475 | 769 | .flag_changed = wakeup_flag_changed, |
3244351c SR |
770 | #ifdef CONFIG_FTRACE_SELFTEST |
771 | .selftest = trace_selftest_startup_wakeup, | |
772 | #endif | |
7495a5be JO |
773 | .open = wakeup_trace_open, |
774 | .close = wakeup_trace_close, | |
65daaca7 | 775 | .allow_instances = true, |
f43c738b | 776 | .use_max_tr = true, |
3244351c SR |
777 | }; |
778 | ||
af6ace76 DF |
779 | static struct tracer wakeup_dl_tracer __read_mostly = |
780 | { | |
781 | .name = "wakeup_dl", | |
782 | .init = wakeup_dl_tracer_init, | |
783 | .reset = wakeup_tracer_reset, | |
784 | .start = wakeup_tracer_start, | |
785 | .stop = wakeup_tracer_stop, | |
af6ace76 DF |
786 | .print_max = true, |
787 | .print_header = wakeup_print_header, | |
788 | .print_line = wakeup_print_line, | |
789 | .flags = &tracer_flags, | |
790 | .set_flag = wakeup_set_flag, | |
791 | .flag_changed = wakeup_flag_changed, | |
792 | #ifdef CONFIG_FTRACE_SELFTEST | |
793 | .selftest = trace_selftest_startup_wakeup, | |
794 | #endif | |
795 | .open = wakeup_trace_open, | |
796 | .close = wakeup_trace_close, | |
797 | .use_max_tr = true, | |
798 | }; | |
799 | ||
352ad25a SR |
800 | __init static int init_wakeup_tracer(void) |
801 | { | |
802 | int ret; | |
803 | ||
804 | ret = register_tracer(&wakeup_tracer); | |
805 | if (ret) | |
806 | return ret; | |
807 | ||
3244351c SR |
808 | ret = register_tracer(&wakeup_rt_tracer); |
809 | if (ret) | |
810 | return ret; | |
811 | ||
af6ace76 DF |
812 | ret = register_tracer(&wakeup_dl_tracer); |
813 | if (ret) | |
814 | return ret; | |
815 | ||
352ad25a SR |
816 | return 0; |
817 | } | |
6f415672 | 818 | core_initcall(init_wakeup_tracer); |