Commit | Line | Data |
---|---|---|
81d68a96 | 1 | /* |
73d8b8bc | 2 | * trace irqs off critical timings |
81d68a96 SR |
3 | * |
4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
5 | * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com> | |
6 | * | |
7 | * From code in the latency_tracer, that is: | |
8 | * | |
9 | * Copyright (C) 2004-2006 Ingo Molnar | |
10 | * Copyright (C) 2004 William Lee Irwin III | |
11 | */ | |
12 | #include <linux/kallsyms.h> | |
13 | #include <linux/debugfs.h> | |
14 | #include <linux/uaccess.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/ftrace.h> | |
17 | #include <linux/fs.h> | |
18 | ||
19 | #include "trace.h" | |
20 | ||
21 | static struct trace_array *irqsoff_trace __read_mostly; | |
22 | static int tracer_enabled __read_mostly; | |
23 | ||
6cd8a4bb SR |
24 | static DEFINE_PER_CPU(int, tracing_cpu); |
25 | ||
89b2f978 SR |
26 | static DEFINE_SPINLOCK(max_trace_lock); |
27 | ||
6cd8a4bb SR |
28 | enum { |
29 | TRACER_IRQS_OFF = (1 << 1), | |
30 | TRACER_PREEMPT_OFF = (1 << 2), | |
31 | }; | |
32 | ||
33 | static int trace_type __read_mostly; | |
34 | ||
e9d25fe6 SR |
35 | static int save_lat_flag; |
36 | ||
62b915f1 JO |
37 | static void stop_irqsoff_tracer(struct trace_array *tr, int graph); |
38 | static int start_irqsoff_tracer(struct trace_array *tr, int graph); | |
39 | ||
6cd8a4bb | 40 | #ifdef CONFIG_PREEMPT_TRACER |
e309b41d | 41 | static inline int |
6cd8a4bb SR |
42 | preempt_trace(void) |
43 | { | |
44 | return ((trace_type & TRACER_PREEMPT_OFF) && preempt_count()); | |
45 | } | |
46 | #else | |
47 | # define preempt_trace() (0) | |
48 | #endif | |
49 | ||
50 | #ifdef CONFIG_IRQSOFF_TRACER | |
e309b41d | 51 | static inline int |
6cd8a4bb SR |
52 | irq_trace(void) |
53 | { | |
54 | return ((trace_type & TRACER_IRQS_OFF) && | |
55 | irqs_disabled()); | |
56 | } | |
57 | #else | |
58 | # define irq_trace() (0) | |
59 | #endif | |
60 | ||
62b915f1 JO |
61 | #define TRACE_DISPLAY_GRAPH 1 |
62 | ||
63 | static struct tracer_opt trace_opts[] = { | |
64 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
65 | /* display latency trace as call graph */ | |
66 | { TRACER_OPT(display-graph, TRACE_DISPLAY_GRAPH) }, | |
67 | #endif | |
68 | { } /* Empty entry */ | |
69 | }; | |
70 | ||
71 | static struct tracer_flags tracer_flags = { | |
72 | .val = 0, | |
73 | .opts = trace_opts, | |
74 | }; | |
75 | ||
76 | #define is_graph() (tracer_flags.val & TRACE_DISPLAY_GRAPH) | |
77 | ||
81d68a96 SR |
78 | /* |
79 | * Sequence count - we record it when starting a measurement and | |
80 | * skip the latency if the sequence has changed - some other section | |
81 | * did a maximum and could disturb our measurement with serial console | |
82 | * printouts, etc. Truly coinciding maximum latencies should be rare | |
83 | * and what happens together happens separately as well, so this doesnt | |
84 | * decrease the validity of the maximum found: | |
85 | */ | |
86 | static __cacheline_aligned_in_smp unsigned long max_sequence; | |
87 | ||
606576ce | 88 | #ifdef CONFIG_FUNCTION_TRACER |
81d68a96 | 89 | /* |
5e6d2b9c SR |
90 | * Prologue for the preempt and irqs off function tracers. |
91 | * | |
92 | * Returns 1 if it is OK to continue, and data->disabled is | |
93 | * incremented. | |
94 | * 0 if the trace is to be ignored, and data->disabled | |
95 | * is kept the same. | |
96 | * | |
97 | * Note, this function is also used outside this ifdef but | |
98 | * inside the #ifdef of the function graph tracer below. | |
99 | * This is OK, since the function graph tracer is | |
100 | * dependent on the function tracer. | |
81d68a96 | 101 | */ |
5e6d2b9c SR |
102 | static int func_prolog_dec(struct trace_array *tr, |
103 | struct trace_array_cpu **data, | |
104 | unsigned long *flags) | |
81d68a96 | 105 | { |
81d68a96 SR |
106 | long disabled; |
107 | int cpu; | |
108 | ||
361943ad SR |
109 | /* |
110 | * Does not matter if we preempt. We test the flags | |
111 | * afterward, to see if irqs are disabled or not. | |
112 | * If we preempt and get a false positive, the flags | |
113 | * test will fail. | |
114 | */ | |
115 | cpu = raw_smp_processor_id(); | |
116 | if (likely(!per_cpu(tracing_cpu, cpu))) | |
5e6d2b9c | 117 | return 0; |
81d68a96 | 118 | |
5e6d2b9c | 119 | local_save_flags(*flags); |
361943ad | 120 | /* slight chance to get a false positive on tracing_cpu */ |
5e6d2b9c SR |
121 | if (!irqs_disabled_flags(*flags)) |
122 | return 0; | |
81d68a96 | 123 | |
5e6d2b9c SR |
124 | *data = tr->data[cpu]; |
125 | disabled = atomic_inc_return(&(*data)->disabled); | |
81d68a96 SR |
126 | |
127 | if (likely(disabled == 1)) | |
5e6d2b9c SR |
128 | return 1; |
129 | ||
130 | atomic_dec(&(*data)->disabled); | |
131 | ||
132 | return 0; | |
133 | } | |
134 | ||
135 | /* | |
136 | * irqsoff uses its own tracer function to keep the overhead down: | |
137 | */ | |
138 | static void | |
139 | irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip) | |
140 | { | |
141 | struct trace_array *tr = irqsoff_trace; | |
142 | struct trace_array_cpu *data; | |
143 | unsigned long flags; | |
144 | ||
145 | if (!func_prolog_dec(tr, &data, &flags)) | |
146 | return; | |
147 | ||
148 | trace_function(tr, ip, parent_ip, flags, preempt_count()); | |
81d68a96 SR |
149 | |
150 | atomic_dec(&data->disabled); | |
151 | } | |
152 | ||
153 | static struct ftrace_ops trace_ops __read_mostly = | |
154 | { | |
155 | .func = irqsoff_tracer_call, | |
156 | }; | |
606576ce | 157 | #endif /* CONFIG_FUNCTION_TRACER */ |
81d68a96 | 158 | |
62b915f1 JO |
159 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
160 | static int irqsoff_set_flag(u32 old_flags, u32 bit, int set) | |
161 | { | |
162 | int cpu; | |
163 | ||
164 | if (!(bit & TRACE_DISPLAY_GRAPH)) | |
165 | return -EINVAL; | |
166 | ||
167 | if (!(is_graph() ^ set)) | |
168 | return 0; | |
169 | ||
170 | stop_irqsoff_tracer(irqsoff_trace, !set); | |
171 | ||
172 | for_each_possible_cpu(cpu) | |
173 | per_cpu(tracing_cpu, cpu) = 0; | |
174 | ||
175 | tracing_max_latency = 0; | |
176 | tracing_reset_online_cpus(irqsoff_trace); | |
177 | ||
178 | return start_irqsoff_tracer(irqsoff_trace, set); | |
179 | } | |
180 | ||
181 | static int irqsoff_graph_entry(struct ftrace_graph_ent *trace) | |
182 | { | |
183 | struct trace_array *tr = irqsoff_trace; | |
184 | struct trace_array_cpu *data; | |
185 | unsigned long flags; | |
62b915f1 | 186 | int ret; |
62b915f1 JO |
187 | int pc; |
188 | ||
5e6d2b9c | 189 | if (!func_prolog_dec(tr, &data, &flags)) |
62b915f1 JO |
190 | return 0; |
191 | ||
5e6d2b9c SR |
192 | pc = preempt_count(); |
193 | ret = __trace_graph_entry(tr, trace, flags, pc); | |
62b915f1 | 194 | atomic_dec(&data->disabled); |
5e6d2b9c | 195 | |
62b915f1 JO |
196 | return ret; |
197 | } | |
198 | ||
199 | static void irqsoff_graph_return(struct ftrace_graph_ret *trace) | |
200 | { | |
201 | struct trace_array *tr = irqsoff_trace; | |
202 | struct trace_array_cpu *data; | |
203 | unsigned long flags; | |
62b915f1 JO |
204 | int pc; |
205 | ||
5e6d2b9c | 206 | if (!func_prolog_dec(tr, &data, &flags)) |
62b915f1 JO |
207 | return; |
208 | ||
5e6d2b9c SR |
209 | pc = preempt_count(); |
210 | __trace_graph_return(tr, trace, flags, pc); | |
62b915f1 JO |
211 | atomic_dec(&data->disabled); |
212 | } | |
213 | ||
214 | static void irqsoff_trace_open(struct trace_iterator *iter) | |
215 | { | |
216 | if (is_graph()) | |
217 | graph_trace_open(iter); | |
218 | ||
219 | } | |
220 | ||
221 | static void irqsoff_trace_close(struct trace_iterator *iter) | |
222 | { | |
223 | if (iter->private) | |
224 | graph_trace_close(iter); | |
225 | } | |
226 | ||
227 | #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_CPU | \ | |
228 | TRACE_GRAPH_PRINT_PROC) | |
229 | ||
230 | static enum print_line_t irqsoff_print_line(struct trace_iterator *iter) | |
231 | { | |
62b915f1 JO |
232 | /* |
233 | * In graph mode call the graph tracer output function, | |
234 | * otherwise go with the TRACE_FN event handler | |
235 | */ | |
236 | if (is_graph()) | |
0a772620 | 237 | return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS); |
62b915f1 JO |
238 | |
239 | return TRACE_TYPE_UNHANDLED; | |
240 | } | |
241 | ||
242 | static void irqsoff_print_header(struct seq_file *s) | |
243 | { | |
0a772620 JO |
244 | if (is_graph()) |
245 | print_graph_headers_flags(s, GRAPH_TRACER_FLAGS); | |
246 | else | |
62b915f1 JO |
247 | trace_default_header(s); |
248 | } | |
249 | ||
62b915f1 JO |
250 | static void |
251 | __trace_function(struct trace_array *tr, | |
252 | unsigned long ip, unsigned long parent_ip, | |
253 | unsigned long flags, int pc) | |
254 | { | |
0a772620 JO |
255 | if (is_graph()) |
256 | trace_graph_function(tr, ip, parent_ip, flags, pc); | |
257 | else | |
62b915f1 | 258 | trace_function(tr, ip, parent_ip, flags, pc); |
62b915f1 JO |
259 | } |
260 | ||
261 | #else | |
262 | #define __trace_function trace_function | |
263 | ||
264 | static int irqsoff_set_flag(u32 old_flags, u32 bit, int set) | |
265 | { | |
266 | return -EINVAL; | |
267 | } | |
268 | ||
269 | static int irqsoff_graph_entry(struct ftrace_graph_ent *trace) | |
270 | { | |
271 | return -1; | |
272 | } | |
273 | ||
274 | static enum print_line_t irqsoff_print_line(struct trace_iterator *iter) | |
275 | { | |
276 | return TRACE_TYPE_UNHANDLED; | |
277 | } | |
278 | ||
279 | static void irqsoff_graph_return(struct ftrace_graph_ret *trace) { } | |
280 | static void irqsoff_print_header(struct seq_file *s) { } | |
281 | static void irqsoff_trace_open(struct trace_iterator *iter) { } | |
282 | static void irqsoff_trace_close(struct trace_iterator *iter) { } | |
283 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
284 | ||
81d68a96 SR |
285 | /* |
286 | * Should this new latency be reported/recorded? | |
287 | */ | |
e309b41d | 288 | static int report_latency(cycle_t delta) |
81d68a96 SR |
289 | { |
290 | if (tracing_thresh) { | |
291 | if (delta < tracing_thresh) | |
292 | return 0; | |
293 | } else { | |
294 | if (delta <= tracing_max_latency) | |
295 | return 0; | |
296 | } | |
297 | return 1; | |
298 | } | |
299 | ||
e309b41d | 300 | static void |
81d68a96 SR |
301 | check_critical_timing(struct trace_array *tr, |
302 | struct trace_array_cpu *data, | |
303 | unsigned long parent_ip, | |
304 | int cpu) | |
305 | { | |
89b2f978 | 306 | cycle_t T0, T1, delta; |
81d68a96 | 307 | unsigned long flags; |
38697053 | 308 | int pc; |
81d68a96 | 309 | |
81d68a96 | 310 | T0 = data->preempt_timestamp; |
750ed1a4 | 311 | T1 = ftrace_now(cpu); |
81d68a96 SR |
312 | delta = T1-T0; |
313 | ||
314 | local_save_flags(flags); | |
315 | ||
6450c1d3 SR |
316 | pc = preempt_count(); |
317 | ||
81d68a96 SR |
318 | if (!report_latency(delta)) |
319 | goto out; | |
320 | ||
c7aafc54 | 321 | spin_lock_irqsave(&max_trace_lock, flags); |
81d68a96 | 322 | |
89b2f978 SR |
323 | /* check if we are still the max latency */ |
324 | if (!report_latency(delta)) | |
325 | goto out_unlock; | |
326 | ||
62b915f1 | 327 | __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc); |
cc51a0fc SR |
328 | /* Skip 5 functions to get to the irq/preempt enable function */ |
329 | __trace_stack(tr, flags, 5, pc); | |
81d68a96 | 330 | |
81d68a96 | 331 | if (data->critical_sequence != max_sequence) |
89b2f978 | 332 | goto out_unlock; |
81d68a96 | 333 | |
81d68a96 SR |
334 | data->critical_end = parent_ip; |
335 | ||
b5130b1e CE |
336 | if (likely(!is_tracing_stopped())) { |
337 | tracing_max_latency = delta; | |
338 | update_max_tr_single(tr, current, cpu); | |
339 | } | |
81d68a96 | 340 | |
81d68a96 SR |
341 | max_sequence++; |
342 | ||
89b2f978 | 343 | out_unlock: |
c7aafc54 | 344 | spin_unlock_irqrestore(&max_trace_lock, flags); |
89b2f978 | 345 | |
81d68a96 SR |
346 | out: |
347 | data->critical_sequence = max_sequence; | |
750ed1a4 | 348 | data->preempt_timestamp = ftrace_now(cpu); |
62b915f1 | 349 | __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc); |
81d68a96 SR |
350 | } |
351 | ||
e309b41d | 352 | static inline void |
81d68a96 SR |
353 | start_critical_timing(unsigned long ip, unsigned long parent_ip) |
354 | { | |
355 | int cpu; | |
356 | struct trace_array *tr = irqsoff_trace; | |
357 | struct trace_array_cpu *data; | |
358 | unsigned long flags; | |
359 | ||
360 | if (likely(!tracer_enabled)) | |
361 | return; | |
362 | ||
c5f888ca SR |
363 | cpu = raw_smp_processor_id(); |
364 | ||
365 | if (per_cpu(tracing_cpu, cpu)) | |
6cd8a4bb SR |
366 | return; |
367 | ||
81d68a96 SR |
368 | data = tr->data[cpu]; |
369 | ||
c5f888ca | 370 | if (unlikely(!data) || atomic_read(&data->disabled)) |
81d68a96 SR |
371 | return; |
372 | ||
373 | atomic_inc(&data->disabled); | |
374 | ||
375 | data->critical_sequence = max_sequence; | |
750ed1a4 | 376 | data->preempt_timestamp = ftrace_now(cpu); |
6cd8a4bb | 377 | data->critical_start = parent_ip ? : ip; |
81d68a96 SR |
378 | |
379 | local_save_flags(flags); | |
6cd8a4bb | 380 | |
62b915f1 | 381 | __trace_function(tr, ip, parent_ip, flags, preempt_count()); |
81d68a96 | 382 | |
c5f888ca | 383 | per_cpu(tracing_cpu, cpu) = 1; |
6cd8a4bb | 384 | |
81d68a96 SR |
385 | atomic_dec(&data->disabled); |
386 | } | |
387 | ||
e309b41d | 388 | static inline void |
81d68a96 SR |
389 | stop_critical_timing(unsigned long ip, unsigned long parent_ip) |
390 | { | |
391 | int cpu; | |
392 | struct trace_array *tr = irqsoff_trace; | |
393 | struct trace_array_cpu *data; | |
394 | unsigned long flags; | |
395 | ||
c5f888ca | 396 | cpu = raw_smp_processor_id(); |
6cd8a4bb | 397 | /* Always clear the tracing cpu on stopping the trace */ |
c5f888ca SR |
398 | if (unlikely(per_cpu(tracing_cpu, cpu))) |
399 | per_cpu(tracing_cpu, cpu) = 0; | |
6cd8a4bb SR |
400 | else |
401 | return; | |
402 | ||
403 | if (!tracer_enabled) | |
81d68a96 SR |
404 | return; |
405 | ||
81d68a96 SR |
406 | data = tr->data[cpu]; |
407 | ||
3928a8a2 | 408 | if (unlikely(!data) || |
81d68a96 SR |
409 | !data->critical_start || atomic_read(&data->disabled)) |
410 | return; | |
411 | ||
412 | atomic_inc(&data->disabled); | |
c5f888ca | 413 | |
81d68a96 | 414 | local_save_flags(flags); |
62b915f1 | 415 | __trace_function(tr, ip, parent_ip, flags, preempt_count()); |
6cd8a4bb | 416 | check_critical_timing(tr, data, parent_ip ? : ip, cpu); |
81d68a96 SR |
417 | data->critical_start = 0; |
418 | atomic_dec(&data->disabled); | |
419 | } | |
420 | ||
6cd8a4bb | 421 | /* start and stop critical timings used to for stoppage (in idle) */ |
e309b41d | 422 | void start_critical_timings(void) |
81d68a96 | 423 | { |
6cd8a4bb | 424 | if (preempt_trace() || irq_trace()) |
81d68a96 SR |
425 | start_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
426 | } | |
1fe37104 | 427 | EXPORT_SYMBOL_GPL(start_critical_timings); |
81d68a96 | 428 | |
e309b41d | 429 | void stop_critical_timings(void) |
81d68a96 | 430 | { |
6cd8a4bb | 431 | if (preempt_trace() || irq_trace()) |
81d68a96 SR |
432 | stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
433 | } | |
1fe37104 | 434 | EXPORT_SYMBOL_GPL(stop_critical_timings); |
81d68a96 | 435 | |
6cd8a4bb | 436 | #ifdef CONFIG_IRQSOFF_TRACER |
81d68a96 | 437 | #ifdef CONFIG_PROVE_LOCKING |
e309b41d | 438 | void time_hardirqs_on(unsigned long a0, unsigned long a1) |
81d68a96 | 439 | { |
6cd8a4bb | 440 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
441 | stop_critical_timing(a0, a1); |
442 | } | |
443 | ||
e309b41d | 444 | void time_hardirqs_off(unsigned long a0, unsigned long a1) |
81d68a96 | 445 | { |
6cd8a4bb | 446 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
447 | start_critical_timing(a0, a1); |
448 | } | |
449 | ||
450 | #else /* !CONFIG_PROVE_LOCKING */ | |
451 | ||
452 | /* | |
453 | * Stubs: | |
454 | */ | |
455 | ||
81d68a96 SR |
456 | void trace_softirqs_on(unsigned long ip) |
457 | { | |
458 | } | |
459 | ||
460 | void trace_softirqs_off(unsigned long ip) | |
461 | { | |
462 | } | |
463 | ||
e309b41d | 464 | inline void print_irqtrace_events(struct task_struct *curr) |
81d68a96 SR |
465 | { |
466 | } | |
467 | ||
468 | /* | |
469 | * We are only interested in hardirq on/off events: | |
470 | */ | |
e309b41d | 471 | void trace_hardirqs_on(void) |
81d68a96 | 472 | { |
6cd8a4bb | 473 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
474 | stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
475 | } | |
476 | EXPORT_SYMBOL(trace_hardirqs_on); | |
477 | ||
e309b41d | 478 | void trace_hardirqs_off(void) |
81d68a96 | 479 | { |
6cd8a4bb | 480 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
481 | start_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
482 | } | |
483 | EXPORT_SYMBOL(trace_hardirqs_off); | |
484 | ||
e309b41d | 485 | void trace_hardirqs_on_caller(unsigned long caller_addr) |
81d68a96 | 486 | { |
6cd8a4bb | 487 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
488 | stop_critical_timing(CALLER_ADDR0, caller_addr); |
489 | } | |
490 | EXPORT_SYMBOL(trace_hardirqs_on_caller); | |
491 | ||
e309b41d | 492 | void trace_hardirqs_off_caller(unsigned long caller_addr) |
81d68a96 | 493 | { |
6cd8a4bb | 494 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
495 | start_critical_timing(CALLER_ADDR0, caller_addr); |
496 | } | |
497 | EXPORT_SYMBOL(trace_hardirqs_off_caller); | |
498 | ||
499 | #endif /* CONFIG_PROVE_LOCKING */ | |
6cd8a4bb SR |
500 | #endif /* CONFIG_IRQSOFF_TRACER */ |
501 | ||
502 | #ifdef CONFIG_PREEMPT_TRACER | |
e309b41d | 503 | void trace_preempt_on(unsigned long a0, unsigned long a1) |
6cd8a4bb | 504 | { |
1e01cb0c SR |
505 | if (preempt_trace()) |
506 | stop_critical_timing(a0, a1); | |
6cd8a4bb SR |
507 | } |
508 | ||
e309b41d | 509 | void trace_preempt_off(unsigned long a0, unsigned long a1) |
6cd8a4bb | 510 | { |
1e01cb0c SR |
511 | if (preempt_trace()) |
512 | start_critical_timing(a0, a1); | |
6cd8a4bb SR |
513 | } |
514 | #endif /* CONFIG_PREEMPT_TRACER */ | |
81d68a96 | 515 | |
62b915f1 | 516 | static int start_irqsoff_tracer(struct trace_array *tr, int graph) |
81d68a96 | 517 | { |
62b915f1 JO |
518 | int ret = 0; |
519 | ||
520 | if (!graph) | |
521 | ret = register_ftrace_function(&trace_ops); | |
522 | else | |
523 | ret = register_ftrace_graph(&irqsoff_graph_return, | |
524 | &irqsoff_graph_entry); | |
525 | ||
526 | if (!ret && tracing_is_enabled()) | |
9036990d | 527 | tracer_enabled = 1; |
94523e81 | 528 | else |
9036990d | 529 | tracer_enabled = 0; |
62b915f1 JO |
530 | |
531 | return ret; | |
81d68a96 SR |
532 | } |
533 | ||
62b915f1 | 534 | static void stop_irqsoff_tracer(struct trace_array *tr, int graph) |
81d68a96 | 535 | { |
81d68a96 | 536 | tracer_enabled = 0; |
62b915f1 JO |
537 | |
538 | if (!graph) | |
539 | unregister_ftrace_function(&trace_ops); | |
540 | else | |
541 | unregister_ftrace_graph(); | |
81d68a96 SR |
542 | } |
543 | ||
6cd8a4bb | 544 | static void __irqsoff_tracer_init(struct trace_array *tr) |
81d68a96 | 545 | { |
e9d25fe6 SR |
546 | save_lat_flag = trace_flags & TRACE_ITER_LATENCY_FMT; |
547 | trace_flags |= TRACE_ITER_LATENCY_FMT; | |
548 | ||
745b1626 | 549 | tracing_max_latency = 0; |
81d68a96 | 550 | irqsoff_trace = tr; |
c5f888ca | 551 | /* make sure that the tracer is visible */ |
81d68a96 | 552 | smp_wmb(); |
2f26ebd5 | 553 | tracing_reset_online_cpus(tr); |
62b915f1 JO |
554 | |
555 | if (start_irqsoff_tracer(tr, is_graph())) | |
556 | printk(KERN_ERR "failed to start irqsoff tracer\n"); | |
81d68a96 SR |
557 | } |
558 | ||
559 | static void irqsoff_tracer_reset(struct trace_array *tr) | |
560 | { | |
62b915f1 | 561 | stop_irqsoff_tracer(tr, is_graph()); |
e9d25fe6 SR |
562 | |
563 | if (!save_lat_flag) | |
564 | trace_flags &= ~TRACE_ITER_LATENCY_FMT; | |
81d68a96 SR |
565 | } |
566 | ||
9036990d SR |
567 | static void irqsoff_tracer_start(struct trace_array *tr) |
568 | { | |
9036990d | 569 | tracer_enabled = 1; |
9036990d SR |
570 | } |
571 | ||
572 | static void irqsoff_tracer_stop(struct trace_array *tr) | |
573 | { | |
574 | tracer_enabled = 0; | |
81d68a96 SR |
575 | } |
576 | ||
6cd8a4bb | 577 | #ifdef CONFIG_IRQSOFF_TRACER |
1c80025a | 578 | static int irqsoff_tracer_init(struct trace_array *tr) |
6cd8a4bb SR |
579 | { |
580 | trace_type = TRACER_IRQS_OFF; | |
581 | ||
582 | __irqsoff_tracer_init(tr); | |
1c80025a | 583 | return 0; |
6cd8a4bb | 584 | } |
81d68a96 SR |
585 | static struct tracer irqsoff_tracer __read_mostly = |
586 | { | |
587 | .name = "irqsoff", | |
588 | .init = irqsoff_tracer_init, | |
589 | .reset = irqsoff_tracer_reset, | |
9036990d SR |
590 | .start = irqsoff_tracer_start, |
591 | .stop = irqsoff_tracer_stop, | |
81d68a96 | 592 | .print_max = 1, |
62b915f1 JO |
593 | .print_header = irqsoff_print_header, |
594 | .print_line = irqsoff_print_line, | |
595 | .flags = &tracer_flags, | |
596 | .set_flag = irqsoff_set_flag, | |
60a11774 SR |
597 | #ifdef CONFIG_FTRACE_SELFTEST |
598 | .selftest = trace_selftest_startup_irqsoff, | |
599 | #endif | |
62b915f1 JO |
600 | .open = irqsoff_trace_open, |
601 | .close = irqsoff_trace_close, | |
ef710e10 | 602 | .use_max_tr = 1, |
81d68a96 | 603 | }; |
6cd8a4bb SR |
604 | # define register_irqsoff(trace) register_tracer(&trace) |
605 | #else | |
606 | # define register_irqsoff(trace) do { } while (0) | |
607 | #endif | |
608 | ||
609 | #ifdef CONFIG_PREEMPT_TRACER | |
1c80025a | 610 | static int preemptoff_tracer_init(struct trace_array *tr) |
6cd8a4bb SR |
611 | { |
612 | trace_type = TRACER_PREEMPT_OFF; | |
613 | ||
614 | __irqsoff_tracer_init(tr); | |
1c80025a | 615 | return 0; |
6cd8a4bb SR |
616 | } |
617 | ||
618 | static struct tracer preemptoff_tracer __read_mostly = | |
619 | { | |
620 | .name = "preemptoff", | |
621 | .init = preemptoff_tracer_init, | |
622 | .reset = irqsoff_tracer_reset, | |
9036990d SR |
623 | .start = irqsoff_tracer_start, |
624 | .stop = irqsoff_tracer_stop, | |
6cd8a4bb | 625 | .print_max = 1, |
62b915f1 JO |
626 | .print_header = irqsoff_print_header, |
627 | .print_line = irqsoff_print_line, | |
628 | .flags = &tracer_flags, | |
629 | .set_flag = irqsoff_set_flag, | |
60a11774 SR |
630 | #ifdef CONFIG_FTRACE_SELFTEST |
631 | .selftest = trace_selftest_startup_preemptoff, | |
632 | #endif | |
62b915f1 JO |
633 | .open = irqsoff_trace_open, |
634 | .close = irqsoff_trace_close, | |
ef710e10 | 635 | .use_max_tr = 1, |
6cd8a4bb SR |
636 | }; |
637 | # define register_preemptoff(trace) register_tracer(&trace) | |
638 | #else | |
639 | # define register_preemptoff(trace) do { } while (0) | |
640 | #endif | |
641 | ||
642 | #if defined(CONFIG_IRQSOFF_TRACER) && \ | |
643 | defined(CONFIG_PREEMPT_TRACER) | |
644 | ||
1c80025a | 645 | static int preemptirqsoff_tracer_init(struct trace_array *tr) |
6cd8a4bb SR |
646 | { |
647 | trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF; | |
648 | ||
649 | __irqsoff_tracer_init(tr); | |
1c80025a | 650 | return 0; |
6cd8a4bb SR |
651 | } |
652 | ||
653 | static struct tracer preemptirqsoff_tracer __read_mostly = | |
654 | { | |
655 | .name = "preemptirqsoff", | |
656 | .init = preemptirqsoff_tracer_init, | |
657 | .reset = irqsoff_tracer_reset, | |
9036990d SR |
658 | .start = irqsoff_tracer_start, |
659 | .stop = irqsoff_tracer_stop, | |
6cd8a4bb | 660 | .print_max = 1, |
62b915f1 JO |
661 | .print_header = irqsoff_print_header, |
662 | .print_line = irqsoff_print_line, | |
663 | .flags = &tracer_flags, | |
664 | .set_flag = irqsoff_set_flag, | |
60a11774 SR |
665 | #ifdef CONFIG_FTRACE_SELFTEST |
666 | .selftest = trace_selftest_startup_preemptirqsoff, | |
667 | #endif | |
62b915f1 JO |
668 | .open = irqsoff_trace_open, |
669 | .close = irqsoff_trace_close, | |
ef710e10 | 670 | .use_max_tr = 1, |
6cd8a4bb SR |
671 | }; |
672 | ||
673 | # define register_preemptirqsoff(trace) register_tracer(&trace) | |
674 | #else | |
675 | # define register_preemptirqsoff(trace) do { } while (0) | |
676 | #endif | |
81d68a96 SR |
677 | |
678 | __init static int init_irqsoff_tracer(void) | |
679 | { | |
6cd8a4bb SR |
680 | register_irqsoff(irqsoff_tracer); |
681 | register_preemptoff(preemptoff_tracer); | |
682 | register_preemptirqsoff(preemptirqsoff_tracer); | |
81d68a96 SR |
683 | |
684 | return 0; | |
685 | } | |
686 | device_initcall(init_irqsoff_tracer); |