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 | ||
5389f6fa | 26 | static DEFINE_RAW_SPINLOCK(max_trace_lock); |
89b2f978 | 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 | |
25985edc | 83 | * and what happens together happens separately as well, so this doesn't |
81d68a96 SR |
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, | |
b848914c | 156 | .flags = FTRACE_OPS_FL_GLOBAL, |
81d68a96 | 157 | }; |
606576ce | 158 | #endif /* CONFIG_FUNCTION_TRACER */ |
81d68a96 | 159 | |
62b915f1 JO |
160 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
161 | static int irqsoff_set_flag(u32 old_flags, u32 bit, int set) | |
162 | { | |
163 | int cpu; | |
164 | ||
165 | if (!(bit & TRACE_DISPLAY_GRAPH)) | |
166 | return -EINVAL; | |
167 | ||
168 | if (!(is_graph() ^ set)) | |
169 | return 0; | |
170 | ||
171 | stop_irqsoff_tracer(irqsoff_trace, !set); | |
172 | ||
173 | for_each_possible_cpu(cpu) | |
174 | per_cpu(tracing_cpu, cpu) = 0; | |
175 | ||
176 | tracing_max_latency = 0; | |
177 | tracing_reset_online_cpus(irqsoff_trace); | |
178 | ||
179 | return start_irqsoff_tracer(irqsoff_trace, set); | |
180 | } | |
181 | ||
182 | static int irqsoff_graph_entry(struct ftrace_graph_ent *trace) | |
183 | { | |
184 | struct trace_array *tr = irqsoff_trace; | |
185 | struct trace_array_cpu *data; | |
186 | unsigned long flags; | |
62b915f1 | 187 | int ret; |
62b915f1 JO |
188 | int pc; |
189 | ||
5e6d2b9c | 190 | if (!func_prolog_dec(tr, &data, &flags)) |
62b915f1 JO |
191 | return 0; |
192 | ||
5e6d2b9c SR |
193 | pc = preempt_count(); |
194 | ret = __trace_graph_entry(tr, trace, flags, pc); | |
62b915f1 | 195 | atomic_dec(&data->disabled); |
5e6d2b9c | 196 | |
62b915f1 JO |
197 | return ret; |
198 | } | |
199 | ||
200 | static void irqsoff_graph_return(struct ftrace_graph_ret *trace) | |
201 | { | |
202 | struct trace_array *tr = irqsoff_trace; | |
203 | struct trace_array_cpu *data; | |
204 | unsigned long flags; | |
62b915f1 JO |
205 | int pc; |
206 | ||
5e6d2b9c | 207 | if (!func_prolog_dec(tr, &data, &flags)) |
62b915f1 JO |
208 | return; |
209 | ||
5e6d2b9c SR |
210 | pc = preempt_count(); |
211 | __trace_graph_return(tr, trace, flags, pc); | |
62b915f1 JO |
212 | atomic_dec(&data->disabled); |
213 | } | |
214 | ||
215 | static void irqsoff_trace_open(struct trace_iterator *iter) | |
216 | { | |
217 | if (is_graph()) | |
218 | graph_trace_open(iter); | |
219 | ||
220 | } | |
221 | ||
222 | static void irqsoff_trace_close(struct trace_iterator *iter) | |
223 | { | |
224 | if (iter->private) | |
225 | graph_trace_close(iter); | |
226 | } | |
227 | ||
228 | #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_CPU | \ | |
321e68b0 JO |
229 | TRACE_GRAPH_PRINT_PROC | \ |
230 | TRACE_GRAPH_PRINT_ABS_TIME | \ | |
231 | TRACE_GRAPH_PRINT_DURATION) | |
62b915f1 JO |
232 | |
233 | static enum print_line_t irqsoff_print_line(struct trace_iterator *iter) | |
234 | { | |
62b915f1 JO |
235 | /* |
236 | * In graph mode call the graph tracer output function, | |
237 | * otherwise go with the TRACE_FN event handler | |
238 | */ | |
239 | if (is_graph()) | |
0a772620 | 240 | return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS); |
62b915f1 JO |
241 | |
242 | return TRACE_TYPE_UNHANDLED; | |
243 | } | |
244 | ||
245 | static void irqsoff_print_header(struct seq_file *s) | |
246 | { | |
0a772620 JO |
247 | if (is_graph()) |
248 | print_graph_headers_flags(s, GRAPH_TRACER_FLAGS); | |
249 | else | |
62b915f1 JO |
250 | trace_default_header(s); |
251 | } | |
252 | ||
62b915f1 JO |
253 | static void |
254 | __trace_function(struct trace_array *tr, | |
255 | unsigned long ip, unsigned long parent_ip, | |
256 | unsigned long flags, int pc) | |
257 | { | |
0a772620 JO |
258 | if (is_graph()) |
259 | trace_graph_function(tr, ip, parent_ip, flags, pc); | |
260 | else | |
62b915f1 | 261 | trace_function(tr, ip, parent_ip, flags, pc); |
62b915f1 JO |
262 | } |
263 | ||
264 | #else | |
265 | #define __trace_function trace_function | |
266 | ||
267 | static int irqsoff_set_flag(u32 old_flags, u32 bit, int set) | |
268 | { | |
269 | return -EINVAL; | |
270 | } | |
271 | ||
272 | static int irqsoff_graph_entry(struct ftrace_graph_ent *trace) | |
273 | { | |
274 | return -1; | |
275 | } | |
276 | ||
277 | static enum print_line_t irqsoff_print_line(struct trace_iterator *iter) | |
278 | { | |
279 | return TRACE_TYPE_UNHANDLED; | |
280 | } | |
281 | ||
282 | static void irqsoff_graph_return(struct ftrace_graph_ret *trace) { } | |
62b915f1 JO |
283 | static void irqsoff_trace_open(struct trace_iterator *iter) { } |
284 | static void irqsoff_trace_close(struct trace_iterator *iter) { } | |
7e9a49ef JO |
285 | |
286 | #ifdef CONFIG_FUNCTION_TRACER | |
287 | static void irqsoff_print_header(struct seq_file *s) | |
288 | { | |
289 | trace_default_header(s); | |
290 | } | |
291 | #else | |
292 | static void irqsoff_print_header(struct seq_file *s) | |
293 | { | |
294 | trace_latency_header(s); | |
295 | } | |
296 | #endif /* CONFIG_FUNCTION_TRACER */ | |
62b915f1 JO |
297 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
298 | ||
81d68a96 SR |
299 | /* |
300 | * Should this new latency be reported/recorded? | |
301 | */ | |
e309b41d | 302 | static int report_latency(cycle_t delta) |
81d68a96 SR |
303 | { |
304 | if (tracing_thresh) { | |
305 | if (delta < tracing_thresh) | |
306 | return 0; | |
307 | } else { | |
308 | if (delta <= tracing_max_latency) | |
309 | return 0; | |
310 | } | |
311 | return 1; | |
312 | } | |
313 | ||
e309b41d | 314 | static void |
81d68a96 SR |
315 | check_critical_timing(struct trace_array *tr, |
316 | struct trace_array_cpu *data, | |
317 | unsigned long parent_ip, | |
318 | int cpu) | |
319 | { | |
89b2f978 | 320 | cycle_t T0, T1, delta; |
81d68a96 | 321 | unsigned long flags; |
38697053 | 322 | int pc; |
81d68a96 | 323 | |
81d68a96 | 324 | T0 = data->preempt_timestamp; |
750ed1a4 | 325 | T1 = ftrace_now(cpu); |
81d68a96 SR |
326 | delta = T1-T0; |
327 | ||
328 | local_save_flags(flags); | |
329 | ||
6450c1d3 SR |
330 | pc = preempt_count(); |
331 | ||
81d68a96 SR |
332 | if (!report_latency(delta)) |
333 | goto out; | |
334 | ||
5389f6fa | 335 | raw_spin_lock_irqsave(&max_trace_lock, flags); |
81d68a96 | 336 | |
89b2f978 SR |
337 | /* check if we are still the max latency */ |
338 | if (!report_latency(delta)) | |
339 | goto out_unlock; | |
340 | ||
62b915f1 | 341 | __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc); |
cc51a0fc SR |
342 | /* Skip 5 functions to get to the irq/preempt enable function */ |
343 | __trace_stack(tr, flags, 5, pc); | |
81d68a96 | 344 | |
81d68a96 | 345 | if (data->critical_sequence != max_sequence) |
89b2f978 | 346 | goto out_unlock; |
81d68a96 | 347 | |
81d68a96 SR |
348 | data->critical_end = parent_ip; |
349 | ||
b5130b1e CE |
350 | if (likely(!is_tracing_stopped())) { |
351 | tracing_max_latency = delta; | |
352 | update_max_tr_single(tr, current, cpu); | |
353 | } | |
81d68a96 | 354 | |
81d68a96 SR |
355 | max_sequence++; |
356 | ||
89b2f978 | 357 | out_unlock: |
5389f6fa | 358 | raw_spin_unlock_irqrestore(&max_trace_lock, flags); |
89b2f978 | 359 | |
81d68a96 SR |
360 | out: |
361 | data->critical_sequence = max_sequence; | |
750ed1a4 | 362 | data->preempt_timestamp = ftrace_now(cpu); |
62b915f1 | 363 | __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc); |
81d68a96 SR |
364 | } |
365 | ||
e309b41d | 366 | static inline void |
81d68a96 SR |
367 | start_critical_timing(unsigned long ip, unsigned long parent_ip) |
368 | { | |
369 | int cpu; | |
370 | struct trace_array *tr = irqsoff_trace; | |
371 | struct trace_array_cpu *data; | |
372 | unsigned long flags; | |
373 | ||
374 | if (likely(!tracer_enabled)) | |
375 | return; | |
376 | ||
c5f888ca SR |
377 | cpu = raw_smp_processor_id(); |
378 | ||
379 | if (per_cpu(tracing_cpu, cpu)) | |
6cd8a4bb SR |
380 | return; |
381 | ||
81d68a96 SR |
382 | data = tr->data[cpu]; |
383 | ||
c5f888ca | 384 | if (unlikely(!data) || atomic_read(&data->disabled)) |
81d68a96 SR |
385 | return; |
386 | ||
387 | atomic_inc(&data->disabled); | |
388 | ||
389 | data->critical_sequence = max_sequence; | |
750ed1a4 | 390 | data->preempt_timestamp = ftrace_now(cpu); |
6cd8a4bb | 391 | data->critical_start = parent_ip ? : ip; |
81d68a96 SR |
392 | |
393 | local_save_flags(flags); | |
6cd8a4bb | 394 | |
62b915f1 | 395 | __trace_function(tr, ip, parent_ip, flags, preempt_count()); |
81d68a96 | 396 | |
c5f888ca | 397 | per_cpu(tracing_cpu, cpu) = 1; |
6cd8a4bb | 398 | |
81d68a96 SR |
399 | atomic_dec(&data->disabled); |
400 | } | |
401 | ||
e309b41d | 402 | static inline void |
81d68a96 SR |
403 | stop_critical_timing(unsigned long ip, unsigned long parent_ip) |
404 | { | |
405 | int cpu; | |
406 | struct trace_array *tr = irqsoff_trace; | |
407 | struct trace_array_cpu *data; | |
408 | unsigned long flags; | |
409 | ||
c5f888ca | 410 | cpu = raw_smp_processor_id(); |
6cd8a4bb | 411 | /* Always clear the tracing cpu on stopping the trace */ |
c5f888ca SR |
412 | if (unlikely(per_cpu(tracing_cpu, cpu))) |
413 | per_cpu(tracing_cpu, cpu) = 0; | |
6cd8a4bb SR |
414 | else |
415 | return; | |
416 | ||
417 | if (!tracer_enabled) | |
81d68a96 SR |
418 | return; |
419 | ||
81d68a96 SR |
420 | data = tr->data[cpu]; |
421 | ||
3928a8a2 | 422 | if (unlikely(!data) || |
81d68a96 SR |
423 | !data->critical_start || atomic_read(&data->disabled)) |
424 | return; | |
425 | ||
426 | atomic_inc(&data->disabled); | |
c5f888ca | 427 | |
81d68a96 | 428 | local_save_flags(flags); |
62b915f1 | 429 | __trace_function(tr, ip, parent_ip, flags, preempt_count()); |
6cd8a4bb | 430 | check_critical_timing(tr, data, parent_ip ? : ip, cpu); |
81d68a96 SR |
431 | data->critical_start = 0; |
432 | atomic_dec(&data->disabled); | |
433 | } | |
434 | ||
6cd8a4bb | 435 | /* start and stop critical timings used to for stoppage (in idle) */ |
e309b41d | 436 | void start_critical_timings(void) |
81d68a96 | 437 | { |
6cd8a4bb | 438 | if (preempt_trace() || irq_trace()) |
81d68a96 SR |
439 | start_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
440 | } | |
1fe37104 | 441 | EXPORT_SYMBOL_GPL(start_critical_timings); |
81d68a96 | 442 | |
e309b41d | 443 | void stop_critical_timings(void) |
81d68a96 | 444 | { |
6cd8a4bb | 445 | if (preempt_trace() || irq_trace()) |
81d68a96 SR |
446 | stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
447 | } | |
1fe37104 | 448 | EXPORT_SYMBOL_GPL(stop_critical_timings); |
81d68a96 | 449 | |
6cd8a4bb | 450 | #ifdef CONFIG_IRQSOFF_TRACER |
81d68a96 | 451 | #ifdef CONFIG_PROVE_LOCKING |
e309b41d | 452 | void time_hardirqs_on(unsigned long a0, unsigned long a1) |
81d68a96 | 453 | { |
6cd8a4bb | 454 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
455 | stop_critical_timing(a0, a1); |
456 | } | |
457 | ||
e309b41d | 458 | void time_hardirqs_off(unsigned long a0, unsigned long a1) |
81d68a96 | 459 | { |
6cd8a4bb | 460 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
461 | start_critical_timing(a0, a1); |
462 | } | |
463 | ||
464 | #else /* !CONFIG_PROVE_LOCKING */ | |
465 | ||
466 | /* | |
467 | * Stubs: | |
468 | */ | |
469 | ||
81d68a96 SR |
470 | void trace_softirqs_on(unsigned long ip) |
471 | { | |
472 | } | |
473 | ||
474 | void trace_softirqs_off(unsigned long ip) | |
475 | { | |
476 | } | |
477 | ||
e309b41d | 478 | inline void print_irqtrace_events(struct task_struct *curr) |
81d68a96 SR |
479 | { |
480 | } | |
481 | ||
482 | /* | |
483 | * We are only interested in hardirq on/off events: | |
484 | */ | |
e309b41d | 485 | void trace_hardirqs_on(void) |
81d68a96 | 486 | { |
6cd8a4bb | 487 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
488 | stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
489 | } | |
490 | EXPORT_SYMBOL(trace_hardirqs_on); | |
491 | ||
e309b41d | 492 | void trace_hardirqs_off(void) |
81d68a96 | 493 | { |
6cd8a4bb | 494 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
495 | start_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
496 | } | |
497 | EXPORT_SYMBOL(trace_hardirqs_off); | |
498 | ||
e309b41d | 499 | void trace_hardirqs_on_caller(unsigned long caller_addr) |
81d68a96 | 500 | { |
6cd8a4bb | 501 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
502 | stop_critical_timing(CALLER_ADDR0, caller_addr); |
503 | } | |
504 | EXPORT_SYMBOL(trace_hardirqs_on_caller); | |
505 | ||
e309b41d | 506 | void trace_hardirqs_off_caller(unsigned long caller_addr) |
81d68a96 | 507 | { |
6cd8a4bb | 508 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
509 | start_critical_timing(CALLER_ADDR0, caller_addr); |
510 | } | |
511 | EXPORT_SYMBOL(trace_hardirqs_off_caller); | |
512 | ||
513 | #endif /* CONFIG_PROVE_LOCKING */ | |
6cd8a4bb SR |
514 | #endif /* CONFIG_IRQSOFF_TRACER */ |
515 | ||
516 | #ifdef CONFIG_PREEMPT_TRACER | |
e309b41d | 517 | void trace_preempt_on(unsigned long a0, unsigned long a1) |
6cd8a4bb | 518 | { |
e36de1de | 519 | if (preempt_trace() && !irq_trace()) |
1e01cb0c | 520 | stop_critical_timing(a0, a1); |
6cd8a4bb SR |
521 | } |
522 | ||
e309b41d | 523 | void trace_preempt_off(unsigned long a0, unsigned long a1) |
6cd8a4bb | 524 | { |
e36de1de | 525 | if (preempt_trace() && !irq_trace()) |
1e01cb0c | 526 | start_critical_timing(a0, a1); |
6cd8a4bb SR |
527 | } |
528 | #endif /* CONFIG_PREEMPT_TRACER */ | |
81d68a96 | 529 | |
62b915f1 | 530 | static int start_irqsoff_tracer(struct trace_array *tr, int graph) |
81d68a96 | 531 | { |
62b915f1 JO |
532 | int ret = 0; |
533 | ||
534 | if (!graph) | |
535 | ret = register_ftrace_function(&trace_ops); | |
536 | else | |
537 | ret = register_ftrace_graph(&irqsoff_graph_return, | |
538 | &irqsoff_graph_entry); | |
539 | ||
540 | if (!ret && tracing_is_enabled()) | |
9036990d | 541 | tracer_enabled = 1; |
94523e81 | 542 | else |
9036990d | 543 | tracer_enabled = 0; |
62b915f1 JO |
544 | |
545 | return ret; | |
81d68a96 SR |
546 | } |
547 | ||
62b915f1 | 548 | static void stop_irqsoff_tracer(struct trace_array *tr, int graph) |
81d68a96 | 549 | { |
81d68a96 | 550 | tracer_enabled = 0; |
62b915f1 JO |
551 | |
552 | if (!graph) | |
553 | unregister_ftrace_function(&trace_ops); | |
554 | else | |
555 | unregister_ftrace_graph(); | |
81d68a96 SR |
556 | } |
557 | ||
6cd8a4bb | 558 | static void __irqsoff_tracer_init(struct trace_array *tr) |
81d68a96 | 559 | { |
e9d25fe6 SR |
560 | save_lat_flag = trace_flags & TRACE_ITER_LATENCY_FMT; |
561 | trace_flags |= TRACE_ITER_LATENCY_FMT; | |
562 | ||
745b1626 | 563 | tracing_max_latency = 0; |
81d68a96 | 564 | irqsoff_trace = tr; |
c5f888ca | 565 | /* make sure that the tracer is visible */ |
81d68a96 | 566 | smp_wmb(); |
2f26ebd5 | 567 | tracing_reset_online_cpus(tr); |
62b915f1 JO |
568 | |
569 | if (start_irqsoff_tracer(tr, is_graph())) | |
570 | printk(KERN_ERR "failed to start irqsoff tracer\n"); | |
81d68a96 SR |
571 | } |
572 | ||
573 | static void irqsoff_tracer_reset(struct trace_array *tr) | |
574 | { | |
62b915f1 | 575 | stop_irqsoff_tracer(tr, is_graph()); |
e9d25fe6 SR |
576 | |
577 | if (!save_lat_flag) | |
578 | trace_flags &= ~TRACE_ITER_LATENCY_FMT; | |
81d68a96 SR |
579 | } |
580 | ||
9036990d SR |
581 | static void irqsoff_tracer_start(struct trace_array *tr) |
582 | { | |
9036990d | 583 | tracer_enabled = 1; |
9036990d SR |
584 | } |
585 | ||
586 | static void irqsoff_tracer_stop(struct trace_array *tr) | |
587 | { | |
588 | tracer_enabled = 0; | |
81d68a96 SR |
589 | } |
590 | ||
6cd8a4bb | 591 | #ifdef CONFIG_IRQSOFF_TRACER |
1c80025a | 592 | static int irqsoff_tracer_init(struct trace_array *tr) |
6cd8a4bb SR |
593 | { |
594 | trace_type = TRACER_IRQS_OFF; | |
595 | ||
596 | __irqsoff_tracer_init(tr); | |
1c80025a | 597 | return 0; |
6cd8a4bb | 598 | } |
81d68a96 SR |
599 | static struct tracer irqsoff_tracer __read_mostly = |
600 | { | |
601 | .name = "irqsoff", | |
602 | .init = irqsoff_tracer_init, | |
603 | .reset = irqsoff_tracer_reset, | |
9036990d SR |
604 | .start = irqsoff_tracer_start, |
605 | .stop = irqsoff_tracer_stop, | |
81d68a96 | 606 | .print_max = 1, |
62b915f1 JO |
607 | .print_header = irqsoff_print_header, |
608 | .print_line = irqsoff_print_line, | |
609 | .flags = &tracer_flags, | |
610 | .set_flag = irqsoff_set_flag, | |
60a11774 SR |
611 | #ifdef CONFIG_FTRACE_SELFTEST |
612 | .selftest = trace_selftest_startup_irqsoff, | |
613 | #endif | |
62b915f1 JO |
614 | .open = irqsoff_trace_open, |
615 | .close = irqsoff_trace_close, | |
ef710e10 | 616 | .use_max_tr = 1, |
81d68a96 | 617 | }; |
6cd8a4bb SR |
618 | # define register_irqsoff(trace) register_tracer(&trace) |
619 | #else | |
620 | # define register_irqsoff(trace) do { } while (0) | |
621 | #endif | |
622 | ||
623 | #ifdef CONFIG_PREEMPT_TRACER | |
1c80025a | 624 | static int preemptoff_tracer_init(struct trace_array *tr) |
6cd8a4bb SR |
625 | { |
626 | trace_type = TRACER_PREEMPT_OFF; | |
627 | ||
628 | __irqsoff_tracer_init(tr); | |
1c80025a | 629 | return 0; |
6cd8a4bb SR |
630 | } |
631 | ||
632 | static struct tracer preemptoff_tracer __read_mostly = | |
633 | { | |
634 | .name = "preemptoff", | |
635 | .init = preemptoff_tracer_init, | |
636 | .reset = irqsoff_tracer_reset, | |
9036990d SR |
637 | .start = irqsoff_tracer_start, |
638 | .stop = irqsoff_tracer_stop, | |
6cd8a4bb | 639 | .print_max = 1, |
62b915f1 JO |
640 | .print_header = irqsoff_print_header, |
641 | .print_line = irqsoff_print_line, | |
642 | .flags = &tracer_flags, | |
643 | .set_flag = irqsoff_set_flag, | |
60a11774 SR |
644 | #ifdef CONFIG_FTRACE_SELFTEST |
645 | .selftest = trace_selftest_startup_preemptoff, | |
646 | #endif | |
62b915f1 JO |
647 | .open = irqsoff_trace_open, |
648 | .close = irqsoff_trace_close, | |
ef710e10 | 649 | .use_max_tr = 1, |
6cd8a4bb SR |
650 | }; |
651 | # define register_preemptoff(trace) register_tracer(&trace) | |
652 | #else | |
653 | # define register_preemptoff(trace) do { } while (0) | |
654 | #endif | |
655 | ||
656 | #if defined(CONFIG_IRQSOFF_TRACER) && \ | |
657 | defined(CONFIG_PREEMPT_TRACER) | |
658 | ||
1c80025a | 659 | static int preemptirqsoff_tracer_init(struct trace_array *tr) |
6cd8a4bb SR |
660 | { |
661 | trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF; | |
662 | ||
663 | __irqsoff_tracer_init(tr); | |
1c80025a | 664 | return 0; |
6cd8a4bb SR |
665 | } |
666 | ||
667 | static struct tracer preemptirqsoff_tracer __read_mostly = | |
668 | { | |
669 | .name = "preemptirqsoff", | |
670 | .init = preemptirqsoff_tracer_init, | |
671 | .reset = irqsoff_tracer_reset, | |
9036990d SR |
672 | .start = irqsoff_tracer_start, |
673 | .stop = irqsoff_tracer_stop, | |
6cd8a4bb | 674 | .print_max = 1, |
62b915f1 JO |
675 | .print_header = irqsoff_print_header, |
676 | .print_line = irqsoff_print_line, | |
677 | .flags = &tracer_flags, | |
678 | .set_flag = irqsoff_set_flag, | |
60a11774 SR |
679 | #ifdef CONFIG_FTRACE_SELFTEST |
680 | .selftest = trace_selftest_startup_preemptirqsoff, | |
681 | #endif | |
62b915f1 JO |
682 | .open = irqsoff_trace_open, |
683 | .close = irqsoff_trace_close, | |
ef710e10 | 684 | .use_max_tr = 1, |
6cd8a4bb SR |
685 | }; |
686 | ||
687 | # define register_preemptirqsoff(trace) register_tracer(&trace) | |
688 | #else | |
689 | # define register_preemptirqsoff(trace) do { } while (0) | |
690 | #endif | |
81d68a96 SR |
691 | |
692 | __init static int init_irqsoff_tracer(void) | |
693 | { | |
6cd8a4bb SR |
694 | register_irqsoff(irqsoff_tracer); |
695 | register_preemptoff(preemptoff_tracer); | |
696 | register_preemptirqsoff(preemptirqsoff_tracer); | |
81d68a96 SR |
697 | |
698 | return 0; | |
699 | } | |
700 | device_initcall(init_irqsoff_tracer); |