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> | |
352ad25a SR |
13 | #include <linux/kallsyms.h> |
14 | #include <linux/uaccess.h> | |
15 | #include <linux/ftrace.h> | |
8bd75c77 | 16 | #include <linux/sched/rt.h> |
2d3d891d | 17 | #include <linux/sched/deadline.h> |
ad8d75ff | 18 | #include <trace/events/sched.h> |
352ad25a SR |
19 | #include "trace.h" |
20 | ||
21 | static struct trace_array *wakeup_trace; | |
22 | static int __read_mostly tracer_enabled; | |
23 | ||
24 | static struct task_struct *wakeup_task; | |
25 | static int wakeup_cpu; | |
478142c3 | 26 | static int wakeup_current_cpu; |
352ad25a | 27 | static unsigned wakeup_prio = -1; |
3244351c | 28 | static int wakeup_rt; |
af6ace76 DF |
29 | static int wakeup_dl; |
30 | static int tracing_dl = 0; | |
352ad25a | 31 | |
445c8951 | 32 | static arch_spinlock_t wakeup_lock = |
edc35bd7 | 33 | (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; |
352ad25a | 34 | |
7495a5be | 35 | static void wakeup_reset(struct trace_array *tr); |
e309b41d | 36 | static void __wakeup_reset(struct trace_array *tr); |
7495a5be JO |
37 | static int wakeup_graph_entry(struct ftrace_graph_ent *trace); |
38 | static void wakeup_graph_return(struct ftrace_graph_ret *trace); | |
352ad25a | 39 | |
613f04a0 | 40 | static int save_flags; |
328df475 | 41 | static bool function_enabled; |
e9d25fe6 | 42 | |
7495a5be JO |
43 | #define TRACE_DISPLAY_GRAPH 1 |
44 | ||
45 | static struct tracer_opt trace_opts[] = { | |
46 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
47 | /* display latency trace as call graph */ | |
48 | { TRACER_OPT(display-graph, TRACE_DISPLAY_GRAPH) }, | |
49 | #endif | |
50 | { } /* Empty entry */ | |
51 | }; | |
52 | ||
53 | static struct tracer_flags tracer_flags = { | |
54 | .val = 0, | |
55 | .opts = trace_opts, | |
56 | }; | |
57 | ||
58 | #define is_graph() (tracer_flags.val & TRACE_DISPLAY_GRAPH) | |
59 | ||
606576ce | 60 | #ifdef CONFIG_FUNCTION_TRACER |
542181d3 | 61 | |
7e18d8e7 | 62 | /* |
542181d3 SR |
63 | * Prologue for the wakeup function tracers. |
64 | * | |
65 | * Returns 1 if it is OK to continue, and preemption | |
66 | * is disabled and data->disabled is incremented. | |
67 | * 0 if the trace is to be ignored, and preemption | |
68 | * is not disabled and data->disabled is | |
69 | * kept the same. | |
70 | * | |
71 | * Note, this function is also used outside this ifdef but | |
72 | * inside the #ifdef of the function graph tracer below. | |
73 | * This is OK, since the function graph tracer is | |
74 | * dependent on the function tracer. | |
7e18d8e7 | 75 | */ |
542181d3 SR |
76 | static int |
77 | func_prolog_preempt_disable(struct trace_array *tr, | |
78 | struct trace_array_cpu **data, | |
79 | int *pc) | |
7e18d8e7 | 80 | { |
7e18d8e7 | 81 | long disabled; |
7e18d8e7 SR |
82 | int cpu; |
83 | ||
84 | if (likely(!wakeup_task)) | |
542181d3 | 85 | return 0; |
7e18d8e7 | 86 | |
542181d3 | 87 | *pc = preempt_count(); |
5168ae50 | 88 | preempt_disable_notrace(); |
7e18d8e7 SR |
89 | |
90 | cpu = raw_smp_processor_id(); | |
478142c3 SR |
91 | if (cpu != wakeup_current_cpu) |
92 | goto out_enable; | |
93 | ||
12883efb | 94 | *data = per_cpu_ptr(tr->trace_buffer.data, cpu); |
542181d3 | 95 | disabled = atomic_inc_return(&(*data)->disabled); |
7e18d8e7 SR |
96 | if (unlikely(disabled != 1)) |
97 | goto out; | |
98 | ||
542181d3 | 99 | return 1; |
7e18d8e7 | 100 | |
542181d3 SR |
101 | out: |
102 | atomic_dec(&(*data)->disabled); | |
7e18d8e7 | 103 | |
542181d3 SR |
104 | out_enable: |
105 | preempt_enable_notrace(); | |
106 | return 0; | |
107 | } | |
108 | ||
109 | /* | |
110 | * wakeup uses its own tracer function to keep the overhead down: | |
111 | */ | |
112 | static void | |
a1e2e31d SR |
113 | wakeup_tracer_call(unsigned long ip, unsigned long parent_ip, |
114 | struct ftrace_ops *op, struct pt_regs *pt_regs) | |
542181d3 SR |
115 | { |
116 | struct trace_array *tr = wakeup_trace; | |
117 | struct trace_array_cpu *data; | |
118 | unsigned long flags; | |
119 | int pc; | |
120 | ||
121 | if (!func_prolog_preempt_disable(tr, &data, &pc)) | |
122 | return; | |
123 | ||
124 | local_irq_save(flags); | |
125 | trace_function(tr, ip, parent_ip, flags, pc); | |
e59494f4 | 126 | local_irq_restore(flags); |
7e18d8e7 | 127 | |
7e18d8e7 | 128 | atomic_dec(&data->disabled); |
5168ae50 | 129 | preempt_enable_notrace(); |
7e18d8e7 | 130 | } |
7e40798f | 131 | #endif /* CONFIG_FUNCTION_TRACER */ |
7495a5be | 132 | |
4104d326 | 133 | static int register_wakeup_function(struct trace_array *tr, int graph, int set) |
7495a5be JO |
134 | { |
135 | int ret; | |
136 | ||
328df475 SRRH |
137 | /* 'set' is set if TRACE_ITER_FUNCTION is about to be set */ |
138 | if (function_enabled || (!set && !(trace_flags & TRACE_ITER_FUNCTION))) | |
139 | return 0; | |
140 | ||
141 | if (graph) | |
7495a5be JO |
142 | ret = register_ftrace_graph(&wakeup_graph_return, |
143 | &wakeup_graph_entry); | |
328df475 | 144 | else |
4104d326 | 145 | ret = register_ftrace_function(tr->ops); |
328df475 SRRH |
146 | |
147 | if (!ret) | |
148 | function_enabled = true; | |
149 | ||
150 | return ret; | |
151 | } | |
152 | ||
4104d326 | 153 | static void unregister_wakeup_function(struct trace_array *tr, int graph) |
328df475 SRRH |
154 | { |
155 | if (!function_enabled) | |
156 | return; | |
157 | ||
158 | if (graph) | |
159 | unregister_ftrace_graph(); | |
160 | else | |
4104d326 | 161 | unregister_ftrace_function(tr->ops); |
328df475 SRRH |
162 | |
163 | function_enabled = false; | |
164 | } | |
165 | ||
4104d326 | 166 | static void wakeup_function_set(struct trace_array *tr, int set) |
328df475 SRRH |
167 | { |
168 | if (set) | |
4104d326 | 169 | register_wakeup_function(tr, is_graph(), 1); |
328df475 | 170 | else |
4104d326 | 171 | unregister_wakeup_function(tr, is_graph()); |
328df475 SRRH |
172 | } |
173 | ||
bf6065b5 | 174 | static int wakeup_flag_changed(struct trace_array *tr, u32 mask, int set) |
328df475 | 175 | { |
bf6065b5 SRRH |
176 | struct tracer *tracer = tr->current_trace; |
177 | ||
328df475 | 178 | if (mask & TRACE_ITER_FUNCTION) |
4104d326 | 179 | wakeup_function_set(tr, set); |
328df475 SRRH |
180 | |
181 | return trace_keep_overwrite(tracer, mask, set); | |
182 | } | |
183 | ||
4104d326 | 184 | static int start_func_tracer(struct trace_array *tr, int graph) |
328df475 SRRH |
185 | { |
186 | int ret; | |
187 | ||
4104d326 | 188 | ret = register_wakeup_function(tr, graph, 0); |
7495a5be JO |
189 | |
190 | if (!ret && tracing_is_enabled()) | |
191 | tracer_enabled = 1; | |
192 | else | |
193 | tracer_enabled = 0; | |
194 | ||
195 | return ret; | |
196 | } | |
197 | ||
4104d326 | 198 | static void stop_func_tracer(struct trace_array *tr, int graph) |
7495a5be JO |
199 | { |
200 | tracer_enabled = 0; | |
201 | ||
4104d326 | 202 | unregister_wakeup_function(tr, graph); |
7495a5be JO |
203 | } |
204 | ||
7495a5be | 205 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
8c1a49ae SRRH |
206 | static int |
207 | wakeup_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set) | |
7495a5be JO |
208 | { |
209 | ||
210 | if (!(bit & TRACE_DISPLAY_GRAPH)) | |
211 | return -EINVAL; | |
212 | ||
213 | if (!(is_graph() ^ set)) | |
214 | return 0; | |
215 | ||
4104d326 | 216 | stop_func_tracer(tr, !set); |
7495a5be JO |
217 | |
218 | wakeup_reset(wakeup_trace); | |
6d9b3fa5 | 219 | tr->max_latency = 0; |
7495a5be | 220 | |
4104d326 | 221 | return start_func_tracer(tr, set); |
7495a5be JO |
222 | } |
223 | ||
224 | static int wakeup_graph_entry(struct ftrace_graph_ent *trace) | |
225 | { | |
226 | struct trace_array *tr = wakeup_trace; | |
227 | struct trace_array_cpu *data; | |
228 | unsigned long flags; | |
542181d3 | 229 | int pc, ret = 0; |
7495a5be | 230 | |
542181d3 | 231 | if (!func_prolog_preempt_disable(tr, &data, &pc)) |
7495a5be JO |
232 | return 0; |
233 | ||
7495a5be JO |
234 | local_save_flags(flags); |
235 | ret = __trace_graph_entry(tr, trace, flags, pc); | |
7495a5be | 236 | atomic_dec(&data->disabled); |
7495a5be | 237 | preempt_enable_notrace(); |
542181d3 | 238 | |
7495a5be JO |
239 | return ret; |
240 | } | |
241 | ||
242 | static void wakeup_graph_return(struct ftrace_graph_ret *trace) | |
243 | { | |
244 | struct trace_array *tr = wakeup_trace; | |
245 | struct trace_array_cpu *data; | |
246 | unsigned long flags; | |
542181d3 | 247 | int pc; |
7495a5be | 248 | |
542181d3 | 249 | if (!func_prolog_preempt_disable(tr, &data, &pc)) |
7495a5be JO |
250 | return; |
251 | ||
7495a5be JO |
252 | local_save_flags(flags); |
253 | __trace_graph_return(tr, trace, flags, pc); | |
7495a5be JO |
254 | atomic_dec(&data->disabled); |
255 | ||
7495a5be JO |
256 | preempt_enable_notrace(); |
257 | return; | |
258 | } | |
259 | ||
260 | static void wakeup_trace_open(struct trace_iterator *iter) | |
261 | { | |
262 | if (is_graph()) | |
263 | graph_trace_open(iter); | |
264 | } | |
265 | ||
266 | static void wakeup_trace_close(struct trace_iterator *iter) | |
267 | { | |
268 | if (iter->private) | |
269 | graph_trace_close(iter); | |
270 | } | |
271 | ||
321e68b0 JO |
272 | #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_PROC | \ |
273 | TRACE_GRAPH_PRINT_ABS_TIME | \ | |
274 | TRACE_GRAPH_PRINT_DURATION) | |
7495a5be JO |
275 | |
276 | static enum print_line_t wakeup_print_line(struct trace_iterator *iter) | |
277 | { | |
278 | /* | |
279 | * In graph mode call the graph tracer output function, | |
280 | * otherwise go with the TRACE_FN event handler | |
281 | */ | |
282 | if (is_graph()) | |
283 | return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS); | |
284 | ||
285 | return TRACE_TYPE_UNHANDLED; | |
286 | } | |
287 | ||
288 | static void wakeup_print_header(struct seq_file *s) | |
289 | { | |
290 | if (is_graph()) | |
291 | print_graph_headers_flags(s, GRAPH_TRACER_FLAGS); | |
292 | else | |
293 | trace_default_header(s); | |
294 | } | |
295 | ||
296 | static void | |
297 | __trace_function(struct trace_array *tr, | |
298 | unsigned long ip, unsigned long parent_ip, | |
299 | unsigned long flags, int pc) | |
300 | { | |
301 | if (is_graph()) | |
302 | trace_graph_function(tr, ip, parent_ip, flags, pc); | |
303 | else | |
304 | trace_function(tr, ip, parent_ip, flags, pc); | |
305 | } | |
306 | #else | |
307 | #define __trace_function trace_function | |
308 | ||
8c1a49ae SRRH |
309 | static int |
310 | wakeup_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set) | |
7495a5be JO |
311 | { |
312 | return -EINVAL; | |
313 | } | |
314 | ||
315 | static int wakeup_graph_entry(struct ftrace_graph_ent *trace) | |
316 | { | |
317 | return -1; | |
318 | } | |
319 | ||
320 | static enum print_line_t wakeup_print_line(struct trace_iterator *iter) | |
321 | { | |
322 | return TRACE_TYPE_UNHANDLED; | |
323 | } | |
324 | ||
325 | static void wakeup_graph_return(struct ftrace_graph_ret *trace) { } | |
7495a5be JO |
326 | static void wakeup_trace_open(struct trace_iterator *iter) { } |
327 | static void wakeup_trace_close(struct trace_iterator *iter) { } | |
7e9a49ef JO |
328 | |
329 | #ifdef CONFIG_FUNCTION_TRACER | |
330 | static void wakeup_print_header(struct seq_file *s) | |
331 | { | |
332 | trace_default_header(s); | |
333 | } | |
334 | #else | |
335 | static void wakeup_print_header(struct seq_file *s) | |
336 | { | |
337 | trace_latency_header(s); | |
338 | } | |
339 | #endif /* CONFIG_FUNCTION_TRACER */ | |
7495a5be JO |
340 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
341 | ||
352ad25a SR |
342 | /* |
343 | * Should this new latency be reported/recorded? | |
344 | */ | |
6d9b3fa5 | 345 | static int report_latency(struct trace_array *tr, cycle_t delta) |
352ad25a SR |
346 | { |
347 | if (tracing_thresh) { | |
348 | if (delta < tracing_thresh) | |
349 | return 0; | |
350 | } else { | |
6d9b3fa5 | 351 | if (delta <= tr->max_latency) |
352ad25a SR |
352 | return 0; |
353 | } | |
354 | return 1; | |
355 | } | |
356 | ||
38516ab5 SR |
357 | static void |
358 | probe_wakeup_migrate_task(void *ignore, struct task_struct *task, int cpu) | |
478142c3 SR |
359 | { |
360 | if (task != wakeup_task) | |
361 | return; | |
362 | ||
363 | wakeup_current_cpu = cpu; | |
364 | } | |
365 | ||
243f7610 SRRH |
366 | static void |
367 | tracing_sched_switch_trace(struct trace_array *tr, | |
368 | struct task_struct *prev, | |
369 | struct task_struct *next, | |
370 | unsigned long flags, int pc) | |
371 | { | |
372 | struct ftrace_event_call *call = &event_context_switch; | |
373 | struct ring_buffer *buffer = tr->trace_buffer.buffer; | |
374 | struct ring_buffer_event *event; | |
375 | struct ctx_switch_entry *entry; | |
376 | ||
377 | event = trace_buffer_lock_reserve(buffer, TRACE_CTX, | |
378 | sizeof(*entry), flags, pc); | |
379 | if (!event) | |
380 | return; | |
381 | entry = ring_buffer_event_data(event); | |
382 | entry->prev_pid = prev->pid; | |
383 | entry->prev_prio = prev->prio; | |
384 | entry->prev_state = prev->state; | |
385 | entry->next_pid = next->pid; | |
386 | entry->next_prio = next->prio; | |
387 | entry->next_state = next->state; | |
388 | entry->next_cpu = task_cpu(next); | |
389 | ||
390 | if (!call_filter_check_discard(call, entry, buffer, event)) | |
391 | trace_buffer_unlock_commit(buffer, event, flags, pc); | |
392 | } | |
393 | ||
394 | static void | |
395 | tracing_sched_wakeup_trace(struct trace_array *tr, | |
396 | struct task_struct *wakee, | |
397 | struct task_struct *curr, | |
398 | unsigned long flags, int pc) | |
399 | { | |
400 | struct ftrace_event_call *call = &event_wakeup; | |
401 | struct ring_buffer_event *event; | |
402 | struct ctx_switch_entry *entry; | |
403 | struct ring_buffer *buffer = tr->trace_buffer.buffer; | |
404 | ||
405 | event = trace_buffer_lock_reserve(buffer, TRACE_WAKE, | |
406 | sizeof(*entry), flags, pc); | |
407 | if (!event) | |
408 | return; | |
409 | entry = ring_buffer_event_data(event); | |
410 | entry->prev_pid = curr->pid; | |
411 | entry->prev_prio = curr->prio; | |
412 | entry->prev_state = curr->state; | |
413 | entry->next_pid = wakee->pid; | |
414 | entry->next_prio = wakee->prio; | |
415 | entry->next_state = wakee->state; | |
416 | entry->next_cpu = task_cpu(wakee); | |
417 | ||
418 | if (!call_filter_check_discard(call, entry, buffer, event)) | |
419 | trace_buffer_unlock_commit(buffer, event, flags, pc); | |
420 | } | |
421 | ||
5b82a1b0 | 422 | static void notrace |
38516ab5 SR |
423 | probe_wakeup_sched_switch(void *ignore, |
424 | struct task_struct *prev, struct task_struct *next) | |
352ad25a | 425 | { |
352ad25a SR |
426 | struct trace_array_cpu *data; |
427 | cycle_t T0, T1, delta; | |
428 | unsigned long flags; | |
429 | long disabled; | |
430 | int cpu; | |
38697053 | 431 | int pc; |
352ad25a | 432 | |
b07c3f19 MD |
433 | tracing_record_cmdline(prev); |
434 | ||
352ad25a SR |
435 | if (unlikely(!tracer_enabled)) |
436 | return; | |
437 | ||
438 | /* | |
439 | * When we start a new trace, we set wakeup_task to NULL | |
440 | * and then set tracer_enabled = 1. We want to make sure | |
441 | * that another CPU does not see the tracer_enabled = 1 | |
442 | * and the wakeup_task with an older task, that might | |
443 | * actually be the same as next. | |
444 | */ | |
445 | smp_rmb(); | |
446 | ||
447 | if (next != wakeup_task) | |
448 | return; | |
449 | ||
38697053 SR |
450 | pc = preempt_count(); |
451 | ||
352ad25a SR |
452 | /* disable local data, not wakeup_cpu data */ |
453 | cpu = raw_smp_processor_id(); | |
12883efb | 454 | disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); |
352ad25a SR |
455 | if (likely(disabled != 1)) |
456 | goto out; | |
457 | ||
e59494f4 | 458 | local_irq_save(flags); |
0199c4e6 | 459 | arch_spin_lock(&wakeup_lock); |
352ad25a SR |
460 | |
461 | /* We could race with grabbing wakeup_lock */ | |
462 | if (unlikely(!tracer_enabled || next != wakeup_task)) | |
463 | goto out_unlock; | |
464 | ||
9be24414 | 465 | /* The task we are waiting for is waking up */ |
12883efb | 466 | data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu); |
9be24414 | 467 | |
7495a5be | 468 | __trace_function(wakeup_trace, CALLER_ADDR0, CALLER_ADDR1, flags, pc); |
7be42151 | 469 | tracing_sched_switch_trace(wakeup_trace, prev, next, flags, pc); |
352ad25a | 470 | |
352ad25a | 471 | T0 = data->preempt_timestamp; |
750ed1a4 | 472 | T1 = ftrace_now(cpu); |
352ad25a SR |
473 | delta = T1-T0; |
474 | ||
6d9b3fa5 | 475 | if (!report_latency(wakeup_trace, delta)) |
352ad25a SR |
476 | goto out_unlock; |
477 | ||
b5130b1e | 478 | if (likely(!is_tracing_stopped())) { |
6d9b3fa5 | 479 | wakeup_trace->max_latency = delta; |
b5130b1e CE |
480 | update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu); |
481 | } | |
352ad25a | 482 | |
352ad25a | 483 | out_unlock: |
b07c3f19 | 484 | __wakeup_reset(wakeup_trace); |
0199c4e6 | 485 | arch_spin_unlock(&wakeup_lock); |
e59494f4 | 486 | local_irq_restore(flags); |
352ad25a | 487 | out: |
12883efb | 488 | atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); |
5b82a1b0 MD |
489 | } |
490 | ||
e309b41d | 491 | static void __wakeup_reset(struct trace_array *tr) |
352ad25a | 492 | { |
352ad25a SR |
493 | wakeup_cpu = -1; |
494 | wakeup_prio = -1; | |
af6ace76 | 495 | tracing_dl = 0; |
352ad25a SR |
496 | |
497 | if (wakeup_task) | |
498 | put_task_struct(wakeup_task); | |
499 | ||
500 | wakeup_task = NULL; | |
501 | } | |
502 | ||
e309b41d | 503 | static void wakeup_reset(struct trace_array *tr) |
352ad25a SR |
504 | { |
505 | unsigned long flags; | |
506 | ||
12883efb | 507 | tracing_reset_online_cpus(&tr->trace_buffer); |
2f26ebd5 | 508 | |
e59494f4 | 509 | local_irq_save(flags); |
0199c4e6 | 510 | arch_spin_lock(&wakeup_lock); |
352ad25a | 511 | __wakeup_reset(tr); |
0199c4e6 | 512 | arch_spin_unlock(&wakeup_lock); |
e59494f4 | 513 | local_irq_restore(flags); |
352ad25a SR |
514 | } |
515 | ||
e309b41d | 516 | static void |
38516ab5 | 517 | probe_wakeup(void *ignore, struct task_struct *p, int success) |
352ad25a | 518 | { |
f8ec1062 | 519 | struct trace_array_cpu *data; |
352ad25a SR |
520 | int cpu = smp_processor_id(); |
521 | unsigned long flags; | |
522 | long disabled; | |
38697053 | 523 | int pc; |
352ad25a | 524 | |
b07c3f19 MD |
525 | if (likely(!tracer_enabled)) |
526 | return; | |
527 | ||
528 | tracing_record_cmdline(p); | |
529 | tracing_record_cmdline(current); | |
530 | ||
af6ace76 DF |
531 | /* |
532 | * Semantic is like this: | |
533 | * - wakeup tracer handles all tasks in the system, independently | |
534 | * from their scheduling class; | |
535 | * - wakeup_rt tracer handles tasks belonging to sched_dl and | |
536 | * sched_rt class; | |
537 | * - wakeup_dl handles tasks belonging to sched_dl class only. | |
538 | */ | |
539 | if (tracing_dl || (wakeup_dl && !dl_task(p)) || | |
540 | (wakeup_rt && !dl_task(p) && !rt_task(p)) || | |
541 | (!dl_task(p) && (p->prio >= wakeup_prio || p->prio >= current->prio))) | |
352ad25a SR |
542 | return; |
543 | ||
38697053 | 544 | pc = preempt_count(); |
12883efb | 545 | disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); |
352ad25a SR |
546 | if (unlikely(disabled != 1)) |
547 | goto out; | |
548 | ||
549 | /* interrupts should be off from try_to_wake_up */ | |
0199c4e6 | 550 | arch_spin_lock(&wakeup_lock); |
352ad25a SR |
551 | |
552 | /* check for races. */ | |
af6ace76 DF |
553 | if (!tracer_enabled || tracing_dl || |
554 | (!dl_task(p) && p->prio >= wakeup_prio)) | |
352ad25a SR |
555 | goto out_locked; |
556 | ||
557 | /* reset the trace */ | |
b07c3f19 | 558 | __wakeup_reset(wakeup_trace); |
352ad25a SR |
559 | |
560 | wakeup_cpu = task_cpu(p); | |
478142c3 | 561 | wakeup_current_cpu = wakeup_cpu; |
352ad25a SR |
562 | wakeup_prio = p->prio; |
563 | ||
af6ace76 DF |
564 | /* |
565 | * Once you start tracing a -deadline task, don't bother tracing | |
566 | * another task until the first one wakes up. | |
567 | */ | |
568 | if (dl_task(p)) | |
569 | tracing_dl = 1; | |
570 | else | |
571 | tracing_dl = 0; | |
572 | ||
352ad25a SR |
573 | wakeup_task = p; |
574 | get_task_struct(wakeup_task); | |
575 | ||
576 | local_save_flags(flags); | |
577 | ||
12883efb | 578 | data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu); |
f8ec1062 | 579 | data->preempt_timestamp = ftrace_now(cpu); |
7be42151 | 580 | tracing_sched_wakeup_trace(wakeup_trace, p, current, flags, pc); |
301fd748 SR |
581 | |
582 | /* | |
583 | * We must be careful in using CALLER_ADDR2. But since wake_up | |
584 | * is not called by an assembly function (where as schedule is) | |
585 | * it should be safe to use it here. | |
586 | */ | |
7495a5be | 587 | __trace_function(wakeup_trace, CALLER_ADDR1, CALLER_ADDR2, flags, pc); |
352ad25a SR |
588 | |
589 | out_locked: | |
0199c4e6 | 590 | arch_spin_unlock(&wakeup_lock); |
352ad25a | 591 | out: |
12883efb | 592 | atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled); |
352ad25a SR |
593 | } |
594 | ||
e309b41d | 595 | static void start_wakeup_tracer(struct trace_array *tr) |
352ad25a | 596 | { |
5b82a1b0 MD |
597 | int ret; |
598 | ||
38516ab5 | 599 | ret = register_trace_sched_wakeup(probe_wakeup, NULL); |
5b82a1b0 | 600 | if (ret) { |
b07c3f19 | 601 | pr_info("wakeup trace: Couldn't activate tracepoint" |
5b82a1b0 MD |
602 | " probe to kernel_sched_wakeup\n"); |
603 | return; | |
604 | } | |
605 | ||
38516ab5 | 606 | ret = register_trace_sched_wakeup_new(probe_wakeup, NULL); |
5b82a1b0 | 607 | if (ret) { |
b07c3f19 | 608 | pr_info("wakeup trace: Couldn't activate tracepoint" |
5b82a1b0 MD |
609 | " probe to kernel_sched_wakeup_new\n"); |
610 | goto fail_deprobe; | |
611 | } | |
612 | ||
38516ab5 | 613 | ret = register_trace_sched_switch(probe_wakeup_sched_switch, NULL); |
5b82a1b0 | 614 | if (ret) { |
b07c3f19 | 615 | pr_info("sched trace: Couldn't activate tracepoint" |
73d8b8bc | 616 | " probe to kernel_sched_switch\n"); |
5b82a1b0 MD |
617 | goto fail_deprobe_wake_new; |
618 | } | |
619 | ||
38516ab5 | 620 | ret = register_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL); |
478142c3 SR |
621 | if (ret) { |
622 | pr_info("wakeup trace: Couldn't activate tracepoint" | |
623 | " probe to kernel_sched_migrate_task\n"); | |
624 | return; | |
625 | } | |
626 | ||
352ad25a SR |
627 | wakeup_reset(tr); |
628 | ||
629 | /* | |
630 | * Don't let the tracer_enabled = 1 show up before | |
631 | * the wakeup_task is reset. This may be overkill since | |
632 | * wakeup_reset does a spin_unlock after setting the | |
633 | * wakeup_task to NULL, but I want to be safe. | |
634 | * This is a slow path anyway. | |
635 | */ | |
636 | smp_wmb(); | |
637 | ||
4104d326 | 638 | if (start_func_tracer(tr, is_graph())) |
7495a5be | 639 | printk(KERN_ERR "failed to start wakeup tracer\n"); |
ad591240 | 640 | |
352ad25a | 641 | return; |
5b82a1b0 | 642 | fail_deprobe_wake_new: |
38516ab5 | 643 | unregister_trace_sched_wakeup_new(probe_wakeup, NULL); |
5b82a1b0 | 644 | fail_deprobe: |
38516ab5 | 645 | unregister_trace_sched_wakeup(probe_wakeup, NULL); |
352ad25a SR |
646 | } |
647 | ||
e309b41d | 648 | static void stop_wakeup_tracer(struct trace_array *tr) |
352ad25a SR |
649 | { |
650 | tracer_enabled = 0; | |
4104d326 | 651 | stop_func_tracer(tr, is_graph()); |
38516ab5 SR |
652 | unregister_trace_sched_switch(probe_wakeup_sched_switch, NULL); |
653 | unregister_trace_sched_wakeup_new(probe_wakeup, NULL); | |
654 | unregister_trace_sched_wakeup(probe_wakeup, NULL); | |
655 | unregister_trace_sched_migrate_task(probe_wakeup_migrate_task, NULL); | |
352ad25a SR |
656 | } |
657 | ||
65daaca7 SRRH |
658 | static bool wakeup_busy; |
659 | ||
3244351c | 660 | static int __wakeup_tracer_init(struct trace_array *tr) |
352ad25a | 661 | { |
613f04a0 SRRH |
662 | save_flags = trace_flags; |
663 | ||
664 | /* non overwrite screws up the latency tracers */ | |
2b6080f2 SR |
665 | set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1); |
666 | set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1); | |
e9d25fe6 | 667 | |
6d9b3fa5 | 668 | tr->max_latency = 0; |
352ad25a | 669 | wakeup_trace = tr; |
4104d326 | 670 | ftrace_init_array_ops(tr, wakeup_tracer_call); |
c76f0694 | 671 | start_wakeup_tracer(tr); |
65daaca7 SRRH |
672 | |
673 | wakeup_busy = true; | |
1c80025a | 674 | return 0; |
352ad25a SR |
675 | } |
676 | ||
3244351c SR |
677 | static int wakeup_tracer_init(struct trace_array *tr) |
678 | { | |
65daaca7 SRRH |
679 | if (wakeup_busy) |
680 | return -EBUSY; | |
681 | ||
af6ace76 | 682 | wakeup_dl = 0; |
3244351c SR |
683 | wakeup_rt = 0; |
684 | return __wakeup_tracer_init(tr); | |
685 | } | |
686 | ||
687 | static int wakeup_rt_tracer_init(struct trace_array *tr) | |
688 | { | |
65daaca7 SRRH |
689 | if (wakeup_busy) |
690 | return -EBUSY; | |
691 | ||
af6ace76 | 692 | wakeup_dl = 0; |
3244351c SR |
693 | wakeup_rt = 1; |
694 | return __wakeup_tracer_init(tr); | |
695 | } | |
696 | ||
af6ace76 DF |
697 | static int wakeup_dl_tracer_init(struct trace_array *tr) |
698 | { | |
65daaca7 SRRH |
699 | if (wakeup_busy) |
700 | return -EBUSY; | |
701 | ||
af6ace76 DF |
702 | wakeup_dl = 1; |
703 | wakeup_rt = 0; | |
704 | return __wakeup_tracer_init(tr); | |
705 | } | |
706 | ||
e309b41d | 707 | static void wakeup_tracer_reset(struct trace_array *tr) |
352ad25a | 708 | { |
613f04a0 SRRH |
709 | int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT; |
710 | int overwrite_flag = save_flags & TRACE_ITER_OVERWRITE; | |
711 | ||
c76f0694 SR |
712 | stop_wakeup_tracer(tr); |
713 | /* make sure we put back any tasks we are tracing */ | |
714 | wakeup_reset(tr); | |
e9d25fe6 | 715 | |
2b6080f2 SR |
716 | set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag); |
717 | set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag); | |
4104d326 | 718 | ftrace_reset_array_ops(tr); |
65daaca7 | 719 | wakeup_busy = false; |
352ad25a SR |
720 | } |
721 | ||
9036990d SR |
722 | static void wakeup_tracer_start(struct trace_array *tr) |
723 | { | |
724 | wakeup_reset(tr); | |
725 | tracer_enabled = 1; | |
9036990d SR |
726 | } |
727 | ||
728 | static void wakeup_tracer_stop(struct trace_array *tr) | |
729 | { | |
730 | tracer_enabled = 0; | |
352ad25a SR |
731 | } |
732 | ||
733 | static struct tracer wakeup_tracer __read_mostly = | |
734 | { | |
735 | .name = "wakeup", | |
736 | .init = wakeup_tracer_init, | |
737 | .reset = wakeup_tracer_reset, | |
9036990d SR |
738 | .start = wakeup_tracer_start, |
739 | .stop = wakeup_tracer_stop, | |
f43c738b | 740 | .print_max = true, |
7495a5be JO |
741 | .print_header = wakeup_print_header, |
742 | .print_line = wakeup_print_line, | |
743 | .flags = &tracer_flags, | |
744 | .set_flag = wakeup_set_flag, | |
328df475 | 745 | .flag_changed = wakeup_flag_changed, |
60a11774 SR |
746 | #ifdef CONFIG_FTRACE_SELFTEST |
747 | .selftest = trace_selftest_startup_wakeup, | |
748 | #endif | |
7495a5be JO |
749 | .open = wakeup_trace_open, |
750 | .close = wakeup_trace_close, | |
65daaca7 | 751 | .allow_instances = true, |
f43c738b | 752 | .use_max_tr = true, |
352ad25a SR |
753 | }; |
754 | ||
3244351c SR |
755 | static struct tracer wakeup_rt_tracer __read_mostly = |
756 | { | |
757 | .name = "wakeup_rt", | |
758 | .init = wakeup_rt_tracer_init, | |
759 | .reset = wakeup_tracer_reset, | |
760 | .start = wakeup_tracer_start, | |
761 | .stop = wakeup_tracer_stop, | |
f43c738b | 762 | .print_max = true, |
7495a5be JO |
763 | .print_header = wakeup_print_header, |
764 | .print_line = wakeup_print_line, | |
765 | .flags = &tracer_flags, | |
766 | .set_flag = wakeup_set_flag, | |
328df475 | 767 | .flag_changed = wakeup_flag_changed, |
3244351c SR |
768 | #ifdef CONFIG_FTRACE_SELFTEST |
769 | .selftest = trace_selftest_startup_wakeup, | |
770 | #endif | |
7495a5be JO |
771 | .open = wakeup_trace_open, |
772 | .close = wakeup_trace_close, | |
65daaca7 | 773 | .allow_instances = true, |
f43c738b | 774 | .use_max_tr = true, |
3244351c SR |
775 | }; |
776 | ||
af6ace76 DF |
777 | static struct tracer wakeup_dl_tracer __read_mostly = |
778 | { | |
779 | .name = "wakeup_dl", | |
780 | .init = wakeup_dl_tracer_init, | |
781 | .reset = wakeup_tracer_reset, | |
782 | .start = wakeup_tracer_start, | |
783 | .stop = wakeup_tracer_stop, | |
af6ace76 DF |
784 | .print_max = true, |
785 | .print_header = wakeup_print_header, | |
786 | .print_line = wakeup_print_line, | |
787 | .flags = &tracer_flags, | |
788 | .set_flag = wakeup_set_flag, | |
789 | .flag_changed = wakeup_flag_changed, | |
790 | #ifdef CONFIG_FTRACE_SELFTEST | |
791 | .selftest = trace_selftest_startup_wakeup, | |
792 | #endif | |
793 | .open = wakeup_trace_open, | |
794 | .close = wakeup_trace_close, | |
795 | .use_max_tr = true, | |
796 | }; | |
797 | ||
352ad25a SR |
798 | __init static int init_wakeup_tracer(void) |
799 | { | |
800 | int ret; | |
801 | ||
802 | ret = register_tracer(&wakeup_tracer); | |
803 | if (ret) | |
804 | return ret; | |
805 | ||
3244351c SR |
806 | ret = register_tracer(&wakeup_rt_tracer); |
807 | if (ret) | |
808 | return ret; | |
809 | ||
af6ace76 DF |
810 | ret = register_tracer(&wakeup_dl_tracer); |
811 | if (ret) | |
812 | return ret; | |
813 | ||
352ad25a SR |
814 | return 0; |
815 | } | |
6f415672 | 816 | core_initcall(init_wakeup_tracer); |