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 | |
6d49e352 | 10 | * Copyright (C) 2004 Nadia Yvette Chambers |
81d68a96 SR |
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 | |
2f5f6ad9 | 139 | irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 140 | struct ftrace_ops *op, struct pt_regs *pt_regs) |
5e6d2b9c SR |
141 | { |
142 | struct trace_array *tr = irqsoff_trace; | |
143 | struct trace_array_cpu *data; | |
144 | unsigned long flags; | |
145 | ||
146 | if (!func_prolog_dec(tr, &data, &flags)) | |
147 | return; | |
148 | ||
149 | trace_function(tr, ip, parent_ip, flags, preempt_count()); | |
81d68a96 SR |
150 | |
151 | atomic_dec(&data->disabled); | |
152 | } | |
153 | ||
154 | static struct ftrace_ops trace_ops __read_mostly = | |
155 | { | |
156 | .func = irqsoff_tracer_call, | |
4740974a | 157 | .flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE, |
81d68a96 | 158 | }; |
606576ce | 159 | #endif /* CONFIG_FUNCTION_TRACER */ |
81d68a96 | 160 | |
62b915f1 JO |
161 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
162 | static int irqsoff_set_flag(u32 old_flags, u32 bit, int set) | |
163 | { | |
164 | int cpu; | |
165 | ||
166 | if (!(bit & TRACE_DISPLAY_GRAPH)) | |
167 | return -EINVAL; | |
168 | ||
169 | if (!(is_graph() ^ set)) | |
170 | return 0; | |
171 | ||
172 | stop_irqsoff_tracer(irqsoff_trace, !set); | |
173 | ||
174 | for_each_possible_cpu(cpu) | |
175 | per_cpu(tracing_cpu, cpu) = 0; | |
176 | ||
177 | tracing_max_latency = 0; | |
178 | tracing_reset_online_cpus(irqsoff_trace); | |
179 | ||
180 | return start_irqsoff_tracer(irqsoff_trace, set); | |
181 | } | |
182 | ||
183 | static int irqsoff_graph_entry(struct ftrace_graph_ent *trace) | |
184 | { | |
185 | struct trace_array *tr = irqsoff_trace; | |
186 | struct trace_array_cpu *data; | |
187 | unsigned long flags; | |
62b915f1 | 188 | int ret; |
62b915f1 JO |
189 | int pc; |
190 | ||
5e6d2b9c | 191 | if (!func_prolog_dec(tr, &data, &flags)) |
62b915f1 JO |
192 | return 0; |
193 | ||
5e6d2b9c SR |
194 | pc = preempt_count(); |
195 | ret = __trace_graph_entry(tr, trace, flags, pc); | |
62b915f1 | 196 | atomic_dec(&data->disabled); |
5e6d2b9c | 197 | |
62b915f1 JO |
198 | return ret; |
199 | } | |
200 | ||
201 | static void irqsoff_graph_return(struct ftrace_graph_ret *trace) | |
202 | { | |
203 | struct trace_array *tr = irqsoff_trace; | |
204 | struct trace_array_cpu *data; | |
205 | unsigned long flags; | |
62b915f1 JO |
206 | int pc; |
207 | ||
5e6d2b9c | 208 | if (!func_prolog_dec(tr, &data, &flags)) |
62b915f1 JO |
209 | return; |
210 | ||
5e6d2b9c SR |
211 | pc = preempt_count(); |
212 | __trace_graph_return(tr, trace, flags, pc); | |
62b915f1 JO |
213 | atomic_dec(&data->disabled); |
214 | } | |
215 | ||
216 | static void irqsoff_trace_open(struct trace_iterator *iter) | |
217 | { | |
218 | if (is_graph()) | |
219 | graph_trace_open(iter); | |
220 | ||
221 | } | |
222 | ||
223 | static void irqsoff_trace_close(struct trace_iterator *iter) | |
224 | { | |
225 | if (iter->private) | |
226 | graph_trace_close(iter); | |
227 | } | |
228 | ||
229 | #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_CPU | \ | |
321e68b0 JO |
230 | TRACE_GRAPH_PRINT_PROC | \ |
231 | TRACE_GRAPH_PRINT_ABS_TIME | \ | |
232 | TRACE_GRAPH_PRINT_DURATION) | |
62b915f1 JO |
233 | |
234 | static enum print_line_t irqsoff_print_line(struct trace_iterator *iter) | |
235 | { | |
62b915f1 JO |
236 | /* |
237 | * In graph mode call the graph tracer output function, | |
238 | * otherwise go with the TRACE_FN event handler | |
239 | */ | |
240 | if (is_graph()) | |
0a772620 | 241 | return print_graph_function_flags(iter, GRAPH_TRACER_FLAGS); |
62b915f1 JO |
242 | |
243 | return TRACE_TYPE_UNHANDLED; | |
244 | } | |
245 | ||
246 | static void irqsoff_print_header(struct seq_file *s) | |
247 | { | |
0a772620 JO |
248 | if (is_graph()) |
249 | print_graph_headers_flags(s, GRAPH_TRACER_FLAGS); | |
250 | else | |
62b915f1 JO |
251 | trace_default_header(s); |
252 | } | |
253 | ||
62b915f1 JO |
254 | static void |
255 | __trace_function(struct trace_array *tr, | |
256 | unsigned long ip, unsigned long parent_ip, | |
257 | unsigned long flags, int pc) | |
258 | { | |
0a772620 JO |
259 | if (is_graph()) |
260 | trace_graph_function(tr, ip, parent_ip, flags, pc); | |
261 | else | |
62b915f1 | 262 | trace_function(tr, ip, parent_ip, flags, pc); |
62b915f1 JO |
263 | } |
264 | ||
265 | #else | |
266 | #define __trace_function trace_function | |
267 | ||
268 | static int irqsoff_set_flag(u32 old_flags, u32 bit, int set) | |
269 | { | |
270 | return -EINVAL; | |
271 | } | |
272 | ||
273 | static int irqsoff_graph_entry(struct ftrace_graph_ent *trace) | |
274 | { | |
275 | return -1; | |
276 | } | |
277 | ||
278 | static enum print_line_t irqsoff_print_line(struct trace_iterator *iter) | |
279 | { | |
280 | return TRACE_TYPE_UNHANDLED; | |
281 | } | |
282 | ||
283 | static void irqsoff_graph_return(struct ftrace_graph_ret *trace) { } | |
62b915f1 JO |
284 | static void irqsoff_trace_open(struct trace_iterator *iter) { } |
285 | static void irqsoff_trace_close(struct trace_iterator *iter) { } | |
7e9a49ef JO |
286 | |
287 | #ifdef CONFIG_FUNCTION_TRACER | |
288 | static void irqsoff_print_header(struct seq_file *s) | |
289 | { | |
290 | trace_default_header(s); | |
291 | } | |
292 | #else | |
293 | static void irqsoff_print_header(struct seq_file *s) | |
294 | { | |
295 | trace_latency_header(s); | |
296 | } | |
297 | #endif /* CONFIG_FUNCTION_TRACER */ | |
62b915f1 JO |
298 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
299 | ||
81d68a96 SR |
300 | /* |
301 | * Should this new latency be reported/recorded? | |
302 | */ | |
e309b41d | 303 | static int report_latency(cycle_t delta) |
81d68a96 SR |
304 | { |
305 | if (tracing_thresh) { | |
306 | if (delta < tracing_thresh) | |
307 | return 0; | |
308 | } else { | |
309 | if (delta <= tracing_max_latency) | |
310 | return 0; | |
311 | } | |
312 | return 1; | |
313 | } | |
314 | ||
e309b41d | 315 | static void |
81d68a96 SR |
316 | check_critical_timing(struct trace_array *tr, |
317 | struct trace_array_cpu *data, | |
318 | unsigned long parent_ip, | |
319 | int cpu) | |
320 | { | |
89b2f978 | 321 | cycle_t T0, T1, delta; |
81d68a96 | 322 | unsigned long flags; |
38697053 | 323 | int pc; |
81d68a96 | 324 | |
81d68a96 | 325 | T0 = data->preempt_timestamp; |
750ed1a4 | 326 | T1 = ftrace_now(cpu); |
81d68a96 SR |
327 | delta = T1-T0; |
328 | ||
329 | local_save_flags(flags); | |
330 | ||
6450c1d3 SR |
331 | pc = preempt_count(); |
332 | ||
81d68a96 SR |
333 | if (!report_latency(delta)) |
334 | goto out; | |
335 | ||
5389f6fa | 336 | raw_spin_lock_irqsave(&max_trace_lock, flags); |
81d68a96 | 337 | |
89b2f978 SR |
338 | /* check if we are still the max latency */ |
339 | if (!report_latency(delta)) | |
340 | goto out_unlock; | |
341 | ||
62b915f1 | 342 | __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc); |
cc51a0fc SR |
343 | /* Skip 5 functions to get to the irq/preempt enable function */ |
344 | __trace_stack(tr, flags, 5, pc); | |
81d68a96 | 345 | |
81d68a96 | 346 | if (data->critical_sequence != max_sequence) |
89b2f978 | 347 | goto out_unlock; |
81d68a96 | 348 | |
81d68a96 SR |
349 | data->critical_end = parent_ip; |
350 | ||
b5130b1e CE |
351 | if (likely(!is_tracing_stopped())) { |
352 | tracing_max_latency = delta; | |
353 | update_max_tr_single(tr, current, cpu); | |
354 | } | |
81d68a96 | 355 | |
81d68a96 SR |
356 | max_sequence++; |
357 | ||
89b2f978 | 358 | out_unlock: |
5389f6fa | 359 | raw_spin_unlock_irqrestore(&max_trace_lock, flags); |
89b2f978 | 360 | |
81d68a96 SR |
361 | out: |
362 | data->critical_sequence = max_sequence; | |
750ed1a4 | 363 | data->preempt_timestamp = ftrace_now(cpu); |
62b915f1 | 364 | __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc); |
81d68a96 SR |
365 | } |
366 | ||
e309b41d | 367 | static inline void |
81d68a96 SR |
368 | start_critical_timing(unsigned long ip, unsigned long parent_ip) |
369 | { | |
370 | int cpu; | |
371 | struct trace_array *tr = irqsoff_trace; | |
372 | struct trace_array_cpu *data; | |
373 | unsigned long flags; | |
374 | ||
375 | if (likely(!tracer_enabled)) | |
376 | return; | |
377 | ||
c5f888ca SR |
378 | cpu = raw_smp_processor_id(); |
379 | ||
380 | if (per_cpu(tracing_cpu, cpu)) | |
6cd8a4bb SR |
381 | return; |
382 | ||
81d68a96 SR |
383 | data = tr->data[cpu]; |
384 | ||
c5f888ca | 385 | if (unlikely(!data) || atomic_read(&data->disabled)) |
81d68a96 SR |
386 | return; |
387 | ||
388 | atomic_inc(&data->disabled); | |
389 | ||
390 | data->critical_sequence = max_sequence; | |
750ed1a4 | 391 | data->preempt_timestamp = ftrace_now(cpu); |
6cd8a4bb | 392 | data->critical_start = parent_ip ? : ip; |
81d68a96 SR |
393 | |
394 | local_save_flags(flags); | |
6cd8a4bb | 395 | |
62b915f1 | 396 | __trace_function(tr, ip, parent_ip, flags, preempt_count()); |
81d68a96 | 397 | |
c5f888ca | 398 | per_cpu(tracing_cpu, cpu) = 1; |
6cd8a4bb | 399 | |
81d68a96 SR |
400 | atomic_dec(&data->disabled); |
401 | } | |
402 | ||
e309b41d | 403 | static inline void |
81d68a96 SR |
404 | stop_critical_timing(unsigned long ip, unsigned long parent_ip) |
405 | { | |
406 | int cpu; | |
407 | struct trace_array *tr = irqsoff_trace; | |
408 | struct trace_array_cpu *data; | |
409 | unsigned long flags; | |
410 | ||
c5f888ca | 411 | cpu = raw_smp_processor_id(); |
6cd8a4bb | 412 | /* Always clear the tracing cpu on stopping the trace */ |
c5f888ca SR |
413 | if (unlikely(per_cpu(tracing_cpu, cpu))) |
414 | per_cpu(tracing_cpu, cpu) = 0; | |
6cd8a4bb SR |
415 | else |
416 | return; | |
417 | ||
418 | if (!tracer_enabled) | |
81d68a96 SR |
419 | return; |
420 | ||
81d68a96 SR |
421 | data = tr->data[cpu]; |
422 | ||
3928a8a2 | 423 | if (unlikely(!data) || |
81d68a96 SR |
424 | !data->critical_start || atomic_read(&data->disabled)) |
425 | return; | |
426 | ||
427 | atomic_inc(&data->disabled); | |
c5f888ca | 428 | |
81d68a96 | 429 | local_save_flags(flags); |
62b915f1 | 430 | __trace_function(tr, ip, parent_ip, flags, preempt_count()); |
6cd8a4bb | 431 | check_critical_timing(tr, data, parent_ip ? : ip, cpu); |
81d68a96 SR |
432 | data->critical_start = 0; |
433 | atomic_dec(&data->disabled); | |
434 | } | |
435 | ||
6cd8a4bb | 436 | /* start and stop critical timings used to for stoppage (in idle) */ |
e309b41d | 437 | void start_critical_timings(void) |
81d68a96 | 438 | { |
6cd8a4bb | 439 | if (preempt_trace() || irq_trace()) |
81d68a96 SR |
440 | start_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
441 | } | |
1fe37104 | 442 | EXPORT_SYMBOL_GPL(start_critical_timings); |
81d68a96 | 443 | |
e309b41d | 444 | void stop_critical_timings(void) |
81d68a96 | 445 | { |
6cd8a4bb | 446 | if (preempt_trace() || irq_trace()) |
81d68a96 SR |
447 | stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
448 | } | |
1fe37104 | 449 | EXPORT_SYMBOL_GPL(stop_critical_timings); |
81d68a96 | 450 | |
6cd8a4bb | 451 | #ifdef CONFIG_IRQSOFF_TRACER |
81d68a96 | 452 | #ifdef CONFIG_PROVE_LOCKING |
e309b41d | 453 | void time_hardirqs_on(unsigned long a0, unsigned long a1) |
81d68a96 | 454 | { |
6cd8a4bb | 455 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
456 | stop_critical_timing(a0, a1); |
457 | } | |
458 | ||
e309b41d | 459 | void time_hardirqs_off(unsigned long a0, unsigned long a1) |
81d68a96 | 460 | { |
6cd8a4bb | 461 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
462 | start_critical_timing(a0, a1); |
463 | } | |
464 | ||
465 | #else /* !CONFIG_PROVE_LOCKING */ | |
466 | ||
467 | /* | |
468 | * Stubs: | |
469 | */ | |
470 | ||
81d68a96 SR |
471 | void trace_softirqs_on(unsigned long ip) |
472 | { | |
473 | } | |
474 | ||
475 | void trace_softirqs_off(unsigned long ip) | |
476 | { | |
477 | } | |
478 | ||
e309b41d | 479 | inline void print_irqtrace_events(struct task_struct *curr) |
81d68a96 SR |
480 | { |
481 | } | |
482 | ||
483 | /* | |
484 | * We are only interested in hardirq on/off events: | |
485 | */ | |
e309b41d | 486 | void trace_hardirqs_on(void) |
81d68a96 | 487 | { |
6cd8a4bb | 488 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
489 | stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
490 | } | |
491 | EXPORT_SYMBOL(trace_hardirqs_on); | |
492 | ||
e309b41d | 493 | void trace_hardirqs_off(void) |
81d68a96 | 494 | { |
6cd8a4bb | 495 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
496 | start_critical_timing(CALLER_ADDR0, CALLER_ADDR1); |
497 | } | |
498 | EXPORT_SYMBOL(trace_hardirqs_off); | |
499 | ||
e309b41d | 500 | void trace_hardirqs_on_caller(unsigned long caller_addr) |
81d68a96 | 501 | { |
6cd8a4bb | 502 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
503 | stop_critical_timing(CALLER_ADDR0, caller_addr); |
504 | } | |
505 | EXPORT_SYMBOL(trace_hardirqs_on_caller); | |
506 | ||
e309b41d | 507 | void trace_hardirqs_off_caller(unsigned long caller_addr) |
81d68a96 | 508 | { |
6cd8a4bb | 509 | if (!preempt_trace() && irq_trace()) |
81d68a96 SR |
510 | start_critical_timing(CALLER_ADDR0, caller_addr); |
511 | } | |
512 | EXPORT_SYMBOL(trace_hardirqs_off_caller); | |
513 | ||
514 | #endif /* CONFIG_PROVE_LOCKING */ | |
6cd8a4bb SR |
515 | #endif /* CONFIG_IRQSOFF_TRACER */ |
516 | ||
517 | #ifdef CONFIG_PREEMPT_TRACER | |
e309b41d | 518 | void trace_preempt_on(unsigned long a0, unsigned long a1) |
6cd8a4bb | 519 | { |
e36de1de | 520 | if (preempt_trace() && !irq_trace()) |
1e01cb0c | 521 | stop_critical_timing(a0, a1); |
6cd8a4bb SR |
522 | } |
523 | ||
e309b41d | 524 | void trace_preempt_off(unsigned long a0, unsigned long a1) |
6cd8a4bb | 525 | { |
e36de1de | 526 | if (preempt_trace() && !irq_trace()) |
1e01cb0c | 527 | start_critical_timing(a0, a1); |
6cd8a4bb SR |
528 | } |
529 | #endif /* CONFIG_PREEMPT_TRACER */ | |
81d68a96 | 530 | |
62b915f1 | 531 | static int start_irqsoff_tracer(struct trace_array *tr, int graph) |
81d68a96 | 532 | { |
62b915f1 JO |
533 | int ret = 0; |
534 | ||
535 | if (!graph) | |
536 | ret = register_ftrace_function(&trace_ops); | |
537 | else | |
538 | ret = register_ftrace_graph(&irqsoff_graph_return, | |
539 | &irqsoff_graph_entry); | |
540 | ||
541 | if (!ret && tracing_is_enabled()) | |
9036990d | 542 | tracer_enabled = 1; |
94523e81 | 543 | else |
9036990d | 544 | tracer_enabled = 0; |
62b915f1 JO |
545 | |
546 | return ret; | |
81d68a96 SR |
547 | } |
548 | ||
62b915f1 | 549 | static void stop_irqsoff_tracer(struct trace_array *tr, int graph) |
81d68a96 | 550 | { |
81d68a96 | 551 | tracer_enabled = 0; |
62b915f1 JO |
552 | |
553 | if (!graph) | |
554 | unregister_ftrace_function(&trace_ops); | |
555 | else | |
556 | unregister_ftrace_graph(); | |
81d68a96 SR |
557 | } |
558 | ||
6cd8a4bb | 559 | static void __irqsoff_tracer_init(struct trace_array *tr) |
81d68a96 | 560 | { |
e9d25fe6 SR |
561 | save_lat_flag = trace_flags & TRACE_ITER_LATENCY_FMT; |
562 | trace_flags |= TRACE_ITER_LATENCY_FMT; | |
563 | ||
745b1626 | 564 | tracing_max_latency = 0; |
81d68a96 | 565 | irqsoff_trace = tr; |
c5f888ca | 566 | /* make sure that the tracer is visible */ |
81d68a96 | 567 | smp_wmb(); |
2f26ebd5 | 568 | tracing_reset_online_cpus(tr); |
62b915f1 JO |
569 | |
570 | if (start_irqsoff_tracer(tr, is_graph())) | |
571 | printk(KERN_ERR "failed to start irqsoff tracer\n"); | |
81d68a96 SR |
572 | } |
573 | ||
574 | static void irqsoff_tracer_reset(struct trace_array *tr) | |
575 | { | |
62b915f1 | 576 | stop_irqsoff_tracer(tr, is_graph()); |
e9d25fe6 SR |
577 | |
578 | if (!save_lat_flag) | |
579 | trace_flags &= ~TRACE_ITER_LATENCY_FMT; | |
81d68a96 SR |
580 | } |
581 | ||
9036990d SR |
582 | static void irqsoff_tracer_start(struct trace_array *tr) |
583 | { | |
9036990d | 584 | tracer_enabled = 1; |
9036990d SR |
585 | } |
586 | ||
587 | static void irqsoff_tracer_stop(struct trace_array *tr) | |
588 | { | |
589 | tracer_enabled = 0; | |
81d68a96 SR |
590 | } |
591 | ||
6cd8a4bb | 592 | #ifdef CONFIG_IRQSOFF_TRACER |
1c80025a | 593 | static int irqsoff_tracer_init(struct trace_array *tr) |
6cd8a4bb SR |
594 | { |
595 | trace_type = TRACER_IRQS_OFF; | |
596 | ||
597 | __irqsoff_tracer_init(tr); | |
1c80025a | 598 | return 0; |
6cd8a4bb | 599 | } |
81d68a96 SR |
600 | static struct tracer irqsoff_tracer __read_mostly = |
601 | { | |
602 | .name = "irqsoff", | |
603 | .init = irqsoff_tracer_init, | |
604 | .reset = irqsoff_tracer_reset, | |
9036990d SR |
605 | .start = irqsoff_tracer_start, |
606 | .stop = irqsoff_tracer_stop, | |
f43c738b | 607 | .print_max = true, |
62b915f1 JO |
608 | .print_header = irqsoff_print_header, |
609 | .print_line = irqsoff_print_line, | |
610 | .flags = &tracer_flags, | |
611 | .set_flag = irqsoff_set_flag, | |
60a11774 SR |
612 | #ifdef CONFIG_FTRACE_SELFTEST |
613 | .selftest = trace_selftest_startup_irqsoff, | |
614 | #endif | |
62b915f1 JO |
615 | .open = irqsoff_trace_open, |
616 | .close = irqsoff_trace_close, | |
f43c738b | 617 | .use_max_tr = true, |
81d68a96 | 618 | }; |
6cd8a4bb SR |
619 | # define register_irqsoff(trace) register_tracer(&trace) |
620 | #else | |
621 | # define register_irqsoff(trace) do { } while (0) | |
622 | #endif | |
623 | ||
624 | #ifdef CONFIG_PREEMPT_TRACER | |
1c80025a | 625 | static int preemptoff_tracer_init(struct trace_array *tr) |
6cd8a4bb SR |
626 | { |
627 | trace_type = TRACER_PREEMPT_OFF; | |
628 | ||
629 | __irqsoff_tracer_init(tr); | |
1c80025a | 630 | return 0; |
6cd8a4bb SR |
631 | } |
632 | ||
633 | static struct tracer preemptoff_tracer __read_mostly = | |
634 | { | |
635 | .name = "preemptoff", | |
636 | .init = preemptoff_tracer_init, | |
637 | .reset = irqsoff_tracer_reset, | |
9036990d SR |
638 | .start = irqsoff_tracer_start, |
639 | .stop = irqsoff_tracer_stop, | |
f43c738b | 640 | .print_max = true, |
62b915f1 JO |
641 | .print_header = irqsoff_print_header, |
642 | .print_line = irqsoff_print_line, | |
643 | .flags = &tracer_flags, | |
644 | .set_flag = irqsoff_set_flag, | |
60a11774 SR |
645 | #ifdef CONFIG_FTRACE_SELFTEST |
646 | .selftest = trace_selftest_startup_preemptoff, | |
647 | #endif | |
62b915f1 JO |
648 | .open = irqsoff_trace_open, |
649 | .close = irqsoff_trace_close, | |
f43c738b | 650 | .use_max_tr = true, |
6cd8a4bb SR |
651 | }; |
652 | # define register_preemptoff(trace) register_tracer(&trace) | |
653 | #else | |
654 | # define register_preemptoff(trace) do { } while (0) | |
655 | #endif | |
656 | ||
657 | #if defined(CONFIG_IRQSOFF_TRACER) && \ | |
658 | defined(CONFIG_PREEMPT_TRACER) | |
659 | ||
1c80025a | 660 | static int preemptirqsoff_tracer_init(struct trace_array *tr) |
6cd8a4bb SR |
661 | { |
662 | trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF; | |
663 | ||
664 | __irqsoff_tracer_init(tr); | |
1c80025a | 665 | return 0; |
6cd8a4bb SR |
666 | } |
667 | ||
668 | static struct tracer preemptirqsoff_tracer __read_mostly = | |
669 | { | |
670 | .name = "preemptirqsoff", | |
671 | .init = preemptirqsoff_tracer_init, | |
672 | .reset = irqsoff_tracer_reset, | |
9036990d SR |
673 | .start = irqsoff_tracer_start, |
674 | .stop = irqsoff_tracer_stop, | |
f43c738b | 675 | .print_max = true, |
62b915f1 JO |
676 | .print_header = irqsoff_print_header, |
677 | .print_line = irqsoff_print_line, | |
678 | .flags = &tracer_flags, | |
679 | .set_flag = irqsoff_set_flag, | |
60a11774 SR |
680 | #ifdef CONFIG_FTRACE_SELFTEST |
681 | .selftest = trace_selftest_startup_preemptirqsoff, | |
682 | #endif | |
62b915f1 JO |
683 | .open = irqsoff_trace_open, |
684 | .close = irqsoff_trace_close, | |
f43c738b | 685 | .use_max_tr = true, |
6cd8a4bb SR |
686 | }; |
687 | ||
688 | # define register_preemptirqsoff(trace) register_tracer(&trace) | |
689 | #else | |
690 | # define register_preemptirqsoff(trace) do { } while (0) | |
691 | #endif | |
81d68a96 SR |
692 | |
693 | __init static int init_irqsoff_tracer(void) | |
694 | { | |
6cd8a4bb SR |
695 | register_irqsoff(irqsoff_tracer); |
696 | register_preemptoff(preemptoff_tracer); | |
697 | register_preemptirqsoff(preemptirqsoff_tracer); | |
81d68a96 SR |
698 | |
699 | return 0; | |
700 | } | |
6f415672 | 701 | core_initcall(init_irqsoff_tracer); |