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 | |
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) { } | |
283 | static void irqsoff_print_header(struct seq_file *s) { } | |
284 | static void irqsoff_trace_open(struct trace_iterator *iter) { } | |
285 | static void irqsoff_trace_close(struct trace_iterator *iter) { } | |
286 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
287 | ||
81d68a96 SR |
288 | /* |
289 | * Should this new latency be reported/recorded? | |
290 | */ | |
e309b41d | 291 | static int report_latency(cycle_t delta) |
81d68a96 SR |
292 | { |
293 | if (tracing_thresh) { | |
294 | if (delta < tracing_thresh) | |
295 | return 0; | |
296 | } else { | |
297 | if (delta <= tracing_max_latency) | |
298 | return 0; | |
299 | } | |
300 | return 1; | |
301 | } | |
302 | ||
e309b41d | 303 | static void |
81d68a96 SR |
304 | check_critical_timing(struct trace_array *tr, |
305 | struct trace_array_cpu *data, | |
306 | unsigned long parent_ip, | |
307 | int cpu) | |
308 | { | |
89b2f978 | 309 | cycle_t T0, T1, delta; |
81d68a96 | 310 | unsigned long flags; |
38697053 | 311 | int pc; |
81d68a96 | 312 | |
81d68a96 | 313 | T0 = data->preempt_timestamp; |
750ed1a4 | 314 | T1 = ftrace_now(cpu); |
81d68a96 SR |
315 | delta = T1-T0; |
316 | ||
317 | local_save_flags(flags); | |
318 | ||
6450c1d3 SR |
319 | pc = preempt_count(); |
320 | ||
81d68a96 SR |
321 | if (!report_latency(delta)) |
322 | goto out; | |
323 | ||
c7aafc54 | 324 | spin_lock_irqsave(&max_trace_lock, flags); |
81d68a96 | 325 | |
89b2f978 SR |
326 | /* check if we are still the max latency */ |
327 | if (!report_latency(delta)) | |
328 | goto out_unlock; | |
329 | ||
62b915f1 | 330 | __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc); |
cc51a0fc SR |
331 | /* Skip 5 functions to get to the irq/preempt enable function */ |
332 | __trace_stack(tr, flags, 5, pc); | |
81d68a96 | 333 | |
81d68a96 | 334 | if (data->critical_sequence != max_sequence) |
89b2f978 | 335 | goto out_unlock; |
81d68a96 | 336 | |
81d68a96 SR |
337 | data->critical_end = parent_ip; |
338 | ||
b5130b1e CE |
339 | if (likely(!is_tracing_stopped())) { |
340 | tracing_max_latency = delta; | |
341 | update_max_tr_single(tr, current, cpu); | |
342 | } | |
81d68a96 | 343 | |
81d68a96 SR |
344 | max_sequence++; |
345 | ||
89b2f978 | 346 | out_unlock: |
c7aafc54 | 347 | spin_unlock_irqrestore(&max_trace_lock, flags); |
89b2f978 | 348 | |
81d68a96 SR |
349 | out: |
350 | data->critical_sequence = max_sequence; | |
750ed1a4 | 351 | data->preempt_timestamp = ftrace_now(cpu); |
62b915f1 | 352 | __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc); |
81d68a96 SR |
353 | } |
354 | ||
e309b41d | 355 | static inline void |
81d68a96 SR |
356 | start_critical_timing(unsigned long ip, unsigned long parent_ip) |
357 | { | |
358 | int cpu; | |
359 | struct trace_array *tr = irqsoff_trace; | |
360 | struct trace_array_cpu *data; | |
361 | unsigned long flags; | |
362 | ||
363 | if (likely(!tracer_enabled)) | |
364 | return; | |
365 | ||
c5f888ca SR |
366 | cpu = raw_smp_processor_id(); |
367 | ||
368 | if (per_cpu(tracing_cpu, cpu)) | |
6cd8a4bb SR |
369 | return; |
370 | ||
81d68a96 SR |
371 | data = tr->data[cpu]; |
372 | ||
c5f888ca | 373 | if (unlikely(!data) || atomic_read(&data->disabled)) |
81d68a96 SR |
374 | return; |
375 | ||
376 | atomic_inc(&data->disabled); | |
377 | ||
378 | data->critical_sequence = max_sequence; | |
750ed1a4 | 379 | data->preempt_timestamp = ftrace_now(cpu); |
6cd8a4bb | 380 | data->critical_start = parent_ip ? : ip; |
81d68a96 SR |
381 | |
382 | local_save_flags(flags); | |
6cd8a4bb | 383 | |
62b915f1 | 384 | __trace_function(tr, ip, parent_ip, flags, preempt_count()); |
81d68a96 | 385 | |
c5f888ca | 386 | per_cpu(tracing_cpu, cpu) = 1; |
6cd8a4bb | 387 | |
81d68a96 SR |
388 | atomic_dec(&data->disabled); |
389 | } | |
390 | ||
e309b41d | 391 | static inline void |
81d68a96 SR |
392 | stop_critical_timing(unsigned long ip, unsigned long parent_ip) |
393 | { | |
394 | int cpu; | |
395 | struct trace_array *tr = irqsoff_trace; | |
396 | struct trace_array_cpu *data; | |
397 | unsigned long flags; | |
398 | ||
c5f888ca | 399 | cpu = raw_smp_processor_id(); |
6cd8a4bb | 400 | /* Always clear the tracing cpu on stopping the trace */ |
c5f888ca SR |
401 | if (unlikely(per_cpu(tracing_cpu, cpu))) |
402 | per_cpu(tracing_cpu, cpu) = 0; | |
6cd8a4bb SR |
403 | else |
404 | return; | |
405 | ||
406 | if (!tracer_enabled) | |
81d68a96 SR |
407 | return; |
408 | ||
81d68a96 SR |
409 | data = tr->data[cpu]; |
410 | ||
3928a8a2 | 411 | if (unlikely(!data) || |
81d68a96 SR |
412 | !data->critical_start || atomic_read(&data->disabled)) |
413 | return; | |
414 | ||
415 | atomic_inc(&data->disabled); | |
c5f888ca | 416 | |
81d68a96 | 417 | local_save_flags(flags); |
62b915f1 | 418 | __trace_function(tr, ip, parent_ip, flags, preempt_count()); |
6cd8a4bb | 419 | check_critical_timing(tr, data, parent_ip ? : ip, cpu); |
81d68a96 SR |
420 | data->critical_start = 0; |
421 | atomic_dec(&data->disabled); | |
422 | } | |
423 | ||
6cd8a4bb | 424 | /* start and stop critical timings used to for stoppage (in idle) */ |
e309b41d | 425 | void start_critical_timings(void) |
81d68a96 | 426 | { |
6cd8a4bb | 427 | if (preempt_trace() || irq_trace()) |
81d68a96 SR |
428 | start_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
429 | } | |
1fe37104 | 430 | EXPORT_SYMBOL_GPL(start_critical_timings); |
81d68a96 | 431 | |
e309b41d | 432 | void stop_critical_timings(void) |
81d68a96 | 433 | { |
6cd8a4bb | 434 | if (preempt_trace() || irq_trace()) |
81d68a96 SR |
435 | stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
436 | } | |
1fe37104 | 437 | EXPORT_SYMBOL_GPL(stop_critical_timings); |
81d68a96 | 438 | |
6cd8a4bb | 439 | #ifdef CONFIG_IRQSOFF_TRACER |
81d68a96 | 440 | #ifdef CONFIG_PROVE_LOCKING |
e309b41d | 441 | void time_hardirqs_on(unsigned long a0, unsigned long a1) |
81d68a96 | 442 | { |
6cd8a4bb | 443 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
444 | stop_critical_timing(a0, a1); |
445 | } | |
446 | ||
e309b41d | 447 | void time_hardirqs_off(unsigned long a0, unsigned long a1) |
81d68a96 | 448 | { |
6cd8a4bb | 449 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
450 | start_critical_timing(a0, a1); |
451 | } | |
452 | ||
453 | #else /* !CONFIG_PROVE_LOCKING */ | |
454 | ||
455 | /* | |
456 | * Stubs: | |
457 | */ | |
458 | ||
81d68a96 SR |
459 | void trace_softirqs_on(unsigned long ip) |
460 | { | |
461 | } | |
462 | ||
463 | void trace_softirqs_off(unsigned long ip) | |
464 | { | |
465 | } | |
466 | ||
e309b41d | 467 | inline void print_irqtrace_events(struct task_struct *curr) |
81d68a96 SR |
468 | { |
469 | } | |
470 | ||
471 | /* | |
472 | * We are only interested in hardirq on/off events: | |
473 | */ | |
e309b41d | 474 | void trace_hardirqs_on(void) |
81d68a96 | 475 | { |
6cd8a4bb | 476 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
477 | stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
478 | } | |
479 | EXPORT_SYMBOL(trace_hardirqs_on); | |
480 | ||
e309b41d | 481 | void trace_hardirqs_off(void) |
81d68a96 | 482 | { |
6cd8a4bb | 483 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
484 | start_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
485 | } | |
486 | EXPORT_SYMBOL(trace_hardirqs_off); | |
487 | ||
e309b41d | 488 | void trace_hardirqs_on_caller(unsigned long caller_addr) |
81d68a96 | 489 | { |
6cd8a4bb | 490 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
491 | stop_critical_timing(CALLER_ADDR0, caller_addr); |
492 | } | |
493 | EXPORT_SYMBOL(trace_hardirqs_on_caller); | |
494 | ||
e309b41d | 495 | void trace_hardirqs_off_caller(unsigned long caller_addr) |
81d68a96 | 496 | { |
6cd8a4bb | 497 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
498 | start_critical_timing(CALLER_ADDR0, caller_addr); |
499 | } | |
500 | EXPORT_SYMBOL(trace_hardirqs_off_caller); | |
501 | ||
502 | #endif /* CONFIG_PROVE_LOCKING */ | |
6cd8a4bb SR |
503 | #endif /* CONFIG_IRQSOFF_TRACER */ |
504 | ||
505 | #ifdef CONFIG_PREEMPT_TRACER | |
e309b41d | 506 | void trace_preempt_on(unsigned long a0, unsigned long a1) |
6cd8a4bb | 507 | { |
1e01cb0c SR |
508 | if (preempt_trace()) |
509 | stop_critical_timing(a0, a1); | |
6cd8a4bb SR |
510 | } |
511 | ||
e309b41d | 512 | void trace_preempt_off(unsigned long a0, unsigned long a1) |
6cd8a4bb | 513 | { |
1e01cb0c SR |
514 | if (preempt_trace()) |
515 | start_critical_timing(a0, a1); | |
6cd8a4bb SR |
516 | } |
517 | #endif /* CONFIG_PREEMPT_TRACER */ | |
81d68a96 | 518 | |
62b915f1 | 519 | static int start_irqsoff_tracer(struct trace_array *tr, int graph) |
81d68a96 | 520 | { |
62b915f1 JO |
521 | int ret = 0; |
522 | ||
523 | if (!graph) | |
524 | ret = register_ftrace_function(&trace_ops); | |
525 | else | |
526 | ret = register_ftrace_graph(&irqsoff_graph_return, | |
527 | &irqsoff_graph_entry); | |
528 | ||
529 | if (!ret && tracing_is_enabled()) | |
9036990d | 530 | tracer_enabled = 1; |
94523e81 | 531 | else |
9036990d | 532 | tracer_enabled = 0; |
62b915f1 JO |
533 | |
534 | return ret; | |
81d68a96 SR |
535 | } |
536 | ||
62b915f1 | 537 | static void stop_irqsoff_tracer(struct trace_array *tr, int graph) |
81d68a96 | 538 | { |
81d68a96 | 539 | tracer_enabled = 0; |
62b915f1 JO |
540 | |
541 | if (!graph) | |
542 | unregister_ftrace_function(&trace_ops); | |
543 | else | |
544 | unregister_ftrace_graph(); | |
81d68a96 SR |
545 | } |
546 | ||
6cd8a4bb | 547 | static void __irqsoff_tracer_init(struct trace_array *tr) |
81d68a96 | 548 | { |
e9d25fe6 SR |
549 | save_lat_flag = trace_flags & TRACE_ITER_LATENCY_FMT; |
550 | trace_flags |= TRACE_ITER_LATENCY_FMT; | |
551 | ||
745b1626 | 552 | tracing_max_latency = 0; |
81d68a96 | 553 | irqsoff_trace = tr; |
c5f888ca | 554 | /* make sure that the tracer is visible */ |
81d68a96 | 555 | smp_wmb(); |
2f26ebd5 | 556 | tracing_reset_online_cpus(tr); |
62b915f1 JO |
557 | |
558 | if (start_irqsoff_tracer(tr, is_graph())) | |
559 | printk(KERN_ERR "failed to start irqsoff tracer\n"); | |
81d68a96 SR |
560 | } |
561 | ||
562 | static void irqsoff_tracer_reset(struct trace_array *tr) | |
563 | { | |
62b915f1 | 564 | stop_irqsoff_tracer(tr, is_graph()); |
e9d25fe6 SR |
565 | |
566 | if (!save_lat_flag) | |
567 | trace_flags &= ~TRACE_ITER_LATENCY_FMT; | |
81d68a96 SR |
568 | } |
569 | ||
9036990d SR |
570 | static void irqsoff_tracer_start(struct trace_array *tr) |
571 | { | |
9036990d | 572 | tracer_enabled = 1; |
9036990d SR |
573 | } |
574 | ||
575 | static void irqsoff_tracer_stop(struct trace_array *tr) | |
576 | { | |
577 | tracer_enabled = 0; | |
81d68a96 SR |
578 | } |
579 | ||
6cd8a4bb | 580 | #ifdef CONFIG_IRQSOFF_TRACER |
1c80025a | 581 | static int irqsoff_tracer_init(struct trace_array *tr) |
6cd8a4bb SR |
582 | { |
583 | trace_type = TRACER_IRQS_OFF; | |
584 | ||
585 | __irqsoff_tracer_init(tr); | |
1c80025a | 586 | return 0; |
6cd8a4bb | 587 | } |
81d68a96 SR |
588 | static struct tracer irqsoff_tracer __read_mostly = |
589 | { | |
590 | .name = "irqsoff", | |
591 | .init = irqsoff_tracer_init, | |
592 | .reset = irqsoff_tracer_reset, | |
9036990d SR |
593 | .start = irqsoff_tracer_start, |
594 | .stop = irqsoff_tracer_stop, | |
81d68a96 | 595 | .print_max = 1, |
62b915f1 JO |
596 | .print_header = irqsoff_print_header, |
597 | .print_line = irqsoff_print_line, | |
598 | .flags = &tracer_flags, | |
599 | .set_flag = irqsoff_set_flag, | |
60a11774 SR |
600 | #ifdef CONFIG_FTRACE_SELFTEST |
601 | .selftest = trace_selftest_startup_irqsoff, | |
602 | #endif | |
62b915f1 JO |
603 | .open = irqsoff_trace_open, |
604 | .close = irqsoff_trace_close, | |
ef710e10 | 605 | .use_max_tr = 1, |
81d68a96 | 606 | }; |
6cd8a4bb SR |
607 | # define register_irqsoff(trace) register_tracer(&trace) |
608 | #else | |
609 | # define register_irqsoff(trace) do { } while (0) | |
610 | #endif | |
611 | ||
612 | #ifdef CONFIG_PREEMPT_TRACER | |
1c80025a | 613 | static int preemptoff_tracer_init(struct trace_array *tr) |
6cd8a4bb SR |
614 | { |
615 | trace_type = TRACER_PREEMPT_OFF; | |
616 | ||
617 | __irqsoff_tracer_init(tr); | |
1c80025a | 618 | return 0; |
6cd8a4bb SR |
619 | } |
620 | ||
621 | static struct tracer preemptoff_tracer __read_mostly = | |
622 | { | |
623 | .name = "preemptoff", | |
624 | .init = preemptoff_tracer_init, | |
625 | .reset = irqsoff_tracer_reset, | |
9036990d SR |
626 | .start = irqsoff_tracer_start, |
627 | .stop = irqsoff_tracer_stop, | |
6cd8a4bb | 628 | .print_max = 1, |
62b915f1 JO |
629 | .print_header = irqsoff_print_header, |
630 | .print_line = irqsoff_print_line, | |
631 | .flags = &tracer_flags, | |
632 | .set_flag = irqsoff_set_flag, | |
60a11774 SR |
633 | #ifdef CONFIG_FTRACE_SELFTEST |
634 | .selftest = trace_selftest_startup_preemptoff, | |
635 | #endif | |
62b915f1 JO |
636 | .open = irqsoff_trace_open, |
637 | .close = irqsoff_trace_close, | |
ef710e10 | 638 | .use_max_tr = 1, |
6cd8a4bb SR |
639 | }; |
640 | # define register_preemptoff(trace) register_tracer(&trace) | |
641 | #else | |
642 | # define register_preemptoff(trace) do { } while (0) | |
643 | #endif | |
644 | ||
645 | #if defined(CONFIG_IRQSOFF_TRACER) && \ | |
646 | defined(CONFIG_PREEMPT_TRACER) | |
647 | ||
1c80025a | 648 | static int preemptirqsoff_tracer_init(struct trace_array *tr) |
6cd8a4bb SR |
649 | { |
650 | trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF; | |
651 | ||
652 | __irqsoff_tracer_init(tr); | |
1c80025a | 653 | return 0; |
6cd8a4bb SR |
654 | } |
655 | ||
656 | static struct tracer preemptirqsoff_tracer __read_mostly = | |
657 | { | |
658 | .name = "preemptirqsoff", | |
659 | .init = preemptirqsoff_tracer_init, | |
660 | .reset = irqsoff_tracer_reset, | |
9036990d SR |
661 | .start = irqsoff_tracer_start, |
662 | .stop = irqsoff_tracer_stop, | |
6cd8a4bb | 663 | .print_max = 1, |
62b915f1 JO |
664 | .print_header = irqsoff_print_header, |
665 | .print_line = irqsoff_print_line, | |
666 | .flags = &tracer_flags, | |
667 | .set_flag = irqsoff_set_flag, | |
60a11774 SR |
668 | #ifdef CONFIG_FTRACE_SELFTEST |
669 | .selftest = trace_selftest_startup_preemptirqsoff, | |
670 | #endif | |
62b915f1 JO |
671 | .open = irqsoff_trace_open, |
672 | .close = irqsoff_trace_close, | |
ef710e10 | 673 | .use_max_tr = 1, |
6cd8a4bb SR |
674 | }; |
675 | ||
676 | # define register_preemptirqsoff(trace) register_tracer(&trace) | |
677 | #else | |
678 | # define register_preemptirqsoff(trace) do { } while (0) | |
679 | #endif | |
81d68a96 SR |
680 | |
681 | __init static int init_irqsoff_tracer(void) | |
682 | { | |
6cd8a4bb SR |
683 | register_irqsoff(irqsoff_tracer); |
684 | register_preemptoff(preemptoff_tracer); | |
685 | register_preemptirqsoff(preemptirqsoff_tracer); | |
81d68a96 SR |
686 | |
687 | return 0; | |
688 | } | |
689 | device_initcall(init_irqsoff_tracer); |