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bc0c38d1 SR |
1 | /* |
2 | * ring buffer based function tracer | |
3 | * | |
4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
5 | * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com> | |
6 | * | |
7 | * Originally taken from the RT patch by: | |
8 | * Arnaldo Carvalho de Melo <acme@redhat.com> | |
9 | * | |
10 | * Based on code from the latency_tracer, that is: | |
11 | * Copyright (C) 2004-2006 Ingo Molnar | |
12 | * Copyright (C) 2004 William Lee Irwin III | |
13 | */ | |
14 | #include <linux/utsrelease.h> | |
15 | #include <linux/kallsyms.h> | |
16 | #include <linux/seq_file.h> | |
17 | #include <linux/debugfs.h> | |
18 | #include <linux/hardirq.h> | |
19 | #include <linux/linkage.h> | |
20 | #include <linux/uaccess.h> | |
21 | #include <linux/ftrace.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/percpu.h> | |
24 | #include <linux/ctype.h> | |
25 | #include <linux/init.h> | |
26 | #include <linux/gfp.h> | |
27 | #include <linux/fs.h> | |
28 | ||
29 | #include "trace.h" | |
30 | ||
31 | unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX; | |
32 | unsigned long __read_mostly tracing_thresh; | |
33 | ||
34 | static long notrace | |
35 | ns2usecs(cycle_t nsec) | |
36 | { | |
37 | nsec += 500; | |
38 | do_div(nsec, 1000); | |
39 | return nsec; | |
40 | } | |
41 | ||
42 | static atomic_t tracer_counter; | |
43 | static struct trace_array global_trace; | |
44 | ||
45 | static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu); | |
46 | ||
47 | static struct trace_array max_tr; | |
48 | ||
49 | static DEFINE_PER_CPU(struct trace_array_cpu, max_data); | |
50 | ||
51 | static int tracer_enabled; | |
52 | static unsigned long trace_nr_entries = 4096UL; | |
53 | ||
54 | static struct tracer *trace_types __read_mostly; | |
55 | static struct tracer *current_trace __read_mostly; | |
56 | static int max_tracer_type_len; | |
57 | ||
58 | static DEFINE_MUTEX(trace_types_lock); | |
59 | ||
60 | static int __init set_nr_entries(char *str) | |
61 | { | |
62 | if (!str) | |
63 | return 0; | |
64 | trace_nr_entries = simple_strtoul(str, &str, 0); | |
65 | return 1; | |
66 | } | |
67 | __setup("trace_entries=", set_nr_entries); | |
68 | ||
69 | enum trace_type { | |
70 | __TRACE_FIRST_TYPE = 0, | |
71 | ||
72 | TRACE_FN, | |
73 | TRACE_CTX, | |
74 | ||
75 | __TRACE_LAST_TYPE | |
76 | }; | |
77 | ||
78 | enum trace_flag_type { | |
79 | TRACE_FLAG_IRQS_OFF = 0x01, | |
80 | TRACE_FLAG_NEED_RESCHED = 0x02, | |
81 | TRACE_FLAG_HARDIRQ = 0x04, | |
82 | TRACE_FLAG_SOFTIRQ = 0x08, | |
83 | }; | |
84 | ||
85 | enum trace_iterator_flags { | |
86 | TRACE_ITER_PRINT_PARENT = 0x01, | |
87 | TRACE_ITER_SYM_OFFSET = 0x02, | |
88 | TRACE_ITER_SYM_ADDR = 0x04, | |
89 | TRACE_ITER_VERBOSE = 0x08, | |
90 | }; | |
91 | ||
92 | #define TRACE_ITER_SYM_MASK \ | |
93 | (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR) | |
94 | ||
95 | /* These must match the bit postions above */ | |
96 | static const char *trace_options[] = { | |
97 | "print-parent", | |
98 | "sym-offset", | |
99 | "sym-addr", | |
100 | "verbose", | |
101 | NULL | |
102 | }; | |
103 | ||
104 | static unsigned trace_flags; | |
105 | ||
106 | ||
107 | /* | |
108 | * Copy the new maximum trace into the separate maximum-trace | |
109 | * structure. (this way the maximum trace is permanently saved, | |
110 | * for later retrieval via /debugfs/tracing/latency_trace) | |
111 | */ | |
112 | static void notrace | |
113 | __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
114 | { | |
115 | struct trace_array_cpu *data = tr->data[cpu]; | |
116 | ||
117 | max_tr.cpu = cpu; | |
118 | max_tr.time_start = data->preempt_timestamp; | |
119 | ||
120 | data = max_tr.data[cpu]; | |
121 | data->saved_latency = tracing_max_latency; | |
122 | ||
123 | memcpy(data->comm, tsk->comm, TASK_COMM_LEN); | |
124 | data->pid = tsk->pid; | |
125 | data->uid = tsk->uid; | |
126 | data->nice = tsk->static_prio - 20 - MAX_RT_PRIO; | |
127 | data->policy = tsk->policy; | |
128 | data->rt_priority = tsk->rt_priority; | |
129 | ||
130 | /* record this tasks comm */ | |
131 | tracing_record_cmdline(current); | |
132 | } | |
133 | ||
134 | notrace void | |
135 | update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
136 | { | |
137 | struct trace_array_cpu *data; | |
138 | void *save_trace; | |
139 | int i; | |
140 | ||
141 | /* clear out all the previous traces */ | |
142 | for_each_possible_cpu(i) { | |
143 | data = tr->data[i]; | |
144 | save_trace = max_tr.data[i]->trace; | |
145 | memcpy(max_tr.data[i], data, sizeof(*data)); | |
146 | data->trace = save_trace; | |
147 | } | |
148 | ||
149 | __update_max_tr(tr, tsk, cpu); | |
150 | } | |
151 | ||
152 | /** | |
153 | * update_max_tr_single - only copy one trace over, and reset the rest | |
154 | * @tr - tracer | |
155 | * @tsk - task with the latency | |
156 | * @cpu - the cpu of the buffer to copy. | |
157 | */ | |
158 | notrace void | |
159 | update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
160 | { | |
161 | struct trace_array_cpu *data = tr->data[cpu]; | |
162 | void *save_trace; | |
163 | int i; | |
164 | ||
165 | for_each_possible_cpu(i) | |
166 | tracing_reset(max_tr.data[i]); | |
167 | ||
168 | save_trace = max_tr.data[cpu]->trace; | |
169 | memcpy(max_tr.data[cpu], data, sizeof(*data)); | |
170 | data->trace = save_trace; | |
171 | ||
172 | __update_max_tr(tr, tsk, cpu); | |
173 | } | |
174 | ||
175 | int register_tracer(struct tracer *type) | |
176 | { | |
177 | struct tracer *t; | |
178 | int len; | |
179 | int ret = 0; | |
180 | ||
181 | if (!type->name) { | |
182 | pr_info("Tracer must have a name\n"); | |
183 | return -1; | |
184 | } | |
185 | ||
186 | mutex_lock(&trace_types_lock); | |
187 | for (t = trace_types; t; t = t->next) { | |
188 | if (strcmp(type->name, t->name) == 0) { | |
189 | /* already found */ | |
190 | pr_info("Trace %s already registered\n", | |
191 | type->name); | |
192 | ret = -1; | |
193 | goto out; | |
194 | } | |
195 | } | |
196 | ||
197 | type->next = trace_types; | |
198 | trace_types = type; | |
199 | len = strlen(type->name); | |
200 | if (len > max_tracer_type_len) | |
201 | max_tracer_type_len = len; | |
202 | out: | |
203 | mutex_unlock(&trace_types_lock); | |
204 | ||
205 | return ret; | |
206 | } | |
207 | ||
208 | void unregister_tracer(struct tracer *type) | |
209 | { | |
210 | struct tracer **t; | |
211 | int len; | |
212 | ||
213 | mutex_lock(&trace_types_lock); | |
214 | for (t = &trace_types; *t; t = &(*t)->next) { | |
215 | if (*t == type) | |
216 | goto found; | |
217 | } | |
218 | pr_info("Trace %s not registered\n", type->name); | |
219 | goto out; | |
220 | ||
221 | found: | |
222 | *t = (*t)->next; | |
223 | if (strlen(type->name) != max_tracer_type_len) | |
224 | goto out; | |
225 | ||
226 | max_tracer_type_len = 0; | |
227 | for (t = &trace_types; *t; t = &(*t)->next) { | |
228 | len = strlen((*t)->name); | |
229 | if (len > max_tracer_type_len) | |
230 | max_tracer_type_len = len; | |
231 | } | |
232 | out: | |
233 | mutex_unlock(&trace_types_lock); | |
234 | } | |
235 | ||
236 | void notrace tracing_reset(struct trace_array_cpu *data) | |
237 | { | |
238 | data->trace_idx = 0; | |
239 | atomic_set(&data->underrun, 0); | |
240 | } | |
241 | ||
242 | #ifdef CONFIG_FTRACE | |
243 | static void notrace | |
244 | function_trace_call(unsigned long ip, unsigned long parent_ip) | |
245 | { | |
246 | struct trace_array *tr = &global_trace; | |
247 | struct trace_array_cpu *data; | |
248 | unsigned long flags; | |
249 | long disabled; | |
250 | int cpu; | |
251 | ||
252 | if (unlikely(!tracer_enabled)) | |
253 | return; | |
254 | ||
255 | raw_local_irq_save(flags); | |
256 | cpu = raw_smp_processor_id(); | |
257 | data = tr->data[cpu]; | |
258 | disabled = atomic_inc_return(&data->disabled); | |
259 | ||
260 | if (likely(disabled == 1)) | |
261 | ftrace(tr, data, ip, parent_ip, flags); | |
262 | ||
263 | atomic_dec(&data->disabled); | |
264 | raw_local_irq_restore(flags); | |
265 | } | |
266 | ||
267 | static struct ftrace_ops trace_ops __read_mostly = | |
268 | { | |
269 | .func = function_trace_call, | |
270 | }; | |
271 | #endif | |
272 | ||
273 | notrace void tracing_start_function_trace(void) | |
274 | { | |
275 | register_ftrace_function(&trace_ops); | |
276 | } | |
277 | ||
278 | notrace void tracing_stop_function_trace(void) | |
279 | { | |
280 | unregister_ftrace_function(&trace_ops); | |
281 | } | |
282 | ||
283 | #define SAVED_CMDLINES 128 | |
284 | static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; | |
285 | static unsigned map_cmdline_to_pid[SAVED_CMDLINES]; | |
286 | static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN]; | |
287 | static int cmdline_idx; | |
288 | static DEFINE_SPINLOCK(trace_cmdline_lock); | |
289 | atomic_t trace_record_cmdline_disabled; | |
290 | ||
291 | static void trace_init_cmdlines(void) | |
292 | { | |
293 | memset(&map_pid_to_cmdline, -1, sizeof(map_pid_to_cmdline)); | |
294 | memset(&map_cmdline_to_pid, -1, sizeof(map_cmdline_to_pid)); | |
295 | cmdline_idx = 0; | |
296 | } | |
297 | ||
298 | notrace void trace_stop_cmdline_recording(void); | |
299 | ||
300 | static void notrace trace_save_cmdline(struct task_struct *tsk) | |
301 | { | |
302 | unsigned map; | |
303 | unsigned idx; | |
304 | ||
305 | if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT)) | |
306 | return; | |
307 | ||
308 | /* | |
309 | * It's not the end of the world if we don't get | |
310 | * the lock, but we also don't want to spin | |
311 | * nor do we want to disable interrupts, | |
312 | * so if we miss here, then better luck next time. | |
313 | */ | |
314 | if (!spin_trylock(&trace_cmdline_lock)) | |
315 | return; | |
316 | ||
317 | idx = map_pid_to_cmdline[tsk->pid]; | |
318 | if (idx >= SAVED_CMDLINES) { | |
319 | idx = (cmdline_idx + 1) % SAVED_CMDLINES; | |
320 | ||
321 | map = map_cmdline_to_pid[idx]; | |
322 | if (map <= PID_MAX_DEFAULT) | |
323 | map_pid_to_cmdline[map] = (unsigned)-1; | |
324 | ||
325 | map_pid_to_cmdline[tsk->pid] = idx; | |
326 | ||
327 | cmdline_idx = idx; | |
328 | } | |
329 | ||
330 | memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN); | |
331 | ||
332 | spin_unlock(&trace_cmdline_lock); | |
333 | } | |
334 | ||
335 | static notrace char *trace_find_cmdline(int pid) | |
336 | { | |
337 | char *cmdline = "<...>"; | |
338 | unsigned map; | |
339 | ||
340 | if (!pid) | |
341 | return "<idle>"; | |
342 | ||
343 | if (pid > PID_MAX_DEFAULT) | |
344 | goto out; | |
345 | ||
346 | map = map_pid_to_cmdline[pid]; | |
347 | if (map >= SAVED_CMDLINES) | |
348 | goto out; | |
349 | ||
350 | cmdline = saved_cmdlines[map]; | |
351 | ||
352 | out: | |
353 | return cmdline; | |
354 | } | |
355 | ||
356 | notrace void tracing_record_cmdline(struct task_struct *tsk) | |
357 | { | |
358 | if (atomic_read(&trace_record_cmdline_disabled)) | |
359 | return; | |
360 | ||
361 | trace_save_cmdline(tsk); | |
362 | } | |
363 | ||
364 | static inline notrace struct trace_entry * | |
365 | tracing_get_trace_entry(struct trace_array *tr, | |
366 | struct trace_array_cpu *data) | |
367 | { | |
368 | unsigned long idx, idx_next; | |
369 | struct trace_entry *entry; | |
370 | ||
371 | idx = data->trace_idx; | |
372 | idx_next = idx + 1; | |
373 | ||
374 | if (unlikely(idx_next >= tr->entries)) { | |
375 | atomic_inc(&data->underrun); | |
376 | idx_next = 0; | |
377 | } | |
378 | ||
379 | data->trace_idx = idx_next; | |
380 | ||
381 | if (unlikely(idx_next != 0 && atomic_read(&data->underrun))) | |
382 | atomic_inc(&data->underrun); | |
383 | ||
384 | entry = data->trace + idx * TRACE_ENTRY_SIZE; | |
385 | ||
386 | return entry; | |
387 | } | |
388 | ||
389 | static inline notrace void | |
390 | tracing_generic_entry_update(struct trace_entry *entry, | |
391 | unsigned long flags) | |
392 | { | |
393 | struct task_struct *tsk = current; | |
394 | unsigned long pc; | |
395 | ||
396 | pc = preempt_count(); | |
397 | ||
398 | entry->idx = atomic_inc_return(&tracer_counter); | |
399 | entry->preempt_count = pc & 0xff; | |
400 | entry->pid = tsk->pid; | |
401 | entry->t = now(raw_smp_processor_id()); | |
402 | entry->flags = (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | | |
403 | ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | | |
404 | ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | | |
405 | (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0); | |
406 | } | |
407 | ||
408 | notrace void | |
409 | ftrace(struct trace_array *tr, struct trace_array_cpu *data, | |
410 | unsigned long ip, unsigned long parent_ip, | |
411 | unsigned long flags) | |
412 | { | |
413 | struct trace_entry *entry; | |
414 | ||
415 | entry = tracing_get_trace_entry(tr, data); | |
416 | tracing_generic_entry_update(entry, flags); | |
417 | entry->type = TRACE_FN; | |
418 | entry->fn.ip = ip; | |
419 | entry->fn.parent_ip = parent_ip; | |
420 | } | |
421 | ||
422 | notrace void | |
423 | tracing_sched_switch_trace(struct trace_array *tr, | |
424 | struct trace_array_cpu *data, | |
425 | struct task_struct *prev, struct task_struct *next, | |
426 | unsigned long flags) | |
427 | { | |
428 | struct trace_entry *entry; | |
429 | ||
430 | entry = tracing_get_trace_entry(tr, data); | |
431 | tracing_generic_entry_update(entry, flags); | |
432 | entry->type = TRACE_CTX; | |
433 | entry->ctx.prev_pid = prev->pid; | |
434 | entry->ctx.prev_prio = prev->prio; | |
435 | entry->ctx.prev_state = prev->state; | |
436 | entry->ctx.next_pid = next->pid; | |
437 | entry->ctx.next_prio = next->prio; | |
438 | } | |
439 | ||
440 | enum trace_file_type { | |
441 | TRACE_FILE_LAT_FMT = 1, | |
442 | }; | |
443 | ||
444 | static struct trace_entry * | |
445 | trace_entry_idx(struct trace_array *tr, unsigned long idx, int cpu) | |
446 | { | |
447 | struct trace_entry *array = tr->data[cpu]->trace; | |
448 | unsigned long underrun; | |
449 | ||
450 | if (idx >= tr->entries) | |
451 | return NULL; | |
452 | ||
453 | underrun = atomic_read(&tr->data[cpu]->underrun); | |
454 | if (underrun) | |
455 | idx = ((underrun - 1) + idx) % tr->entries; | |
456 | else if (idx >= tr->data[cpu]->trace_idx) | |
457 | return NULL; | |
458 | ||
459 | return &array[idx]; | |
460 | } | |
461 | ||
462 | static struct notrace trace_entry * | |
463 | find_next_entry(struct trace_iterator *iter, int *ent_cpu) | |
464 | { | |
465 | struct trace_array *tr = iter->tr; | |
466 | struct trace_entry *ent, *next = NULL; | |
467 | int next_cpu = -1; | |
468 | int cpu; | |
469 | ||
470 | for_each_possible_cpu(cpu) { | |
471 | if (!tr->data[cpu]->trace) | |
472 | continue; | |
473 | ent = trace_entry_idx(tr, iter->next_idx[cpu], cpu); | |
474 | if (ent && | |
475 | (!next || (long)(next->idx - ent->idx) > 0)) { | |
476 | next = ent; | |
477 | next_cpu = cpu; | |
478 | } | |
479 | } | |
480 | ||
481 | if (ent_cpu) | |
482 | *ent_cpu = next_cpu; | |
483 | ||
484 | return next; | |
485 | } | |
486 | ||
487 | static void *find_next_entry_inc(struct trace_iterator *iter) | |
488 | { | |
489 | struct trace_entry *next; | |
490 | int next_cpu = -1; | |
491 | ||
492 | next = find_next_entry(iter, &next_cpu); | |
493 | ||
494 | if (next) { | |
495 | iter->next_idx[next_cpu]++; | |
496 | iter->idx++; | |
497 | } | |
498 | iter->ent = next; | |
499 | iter->cpu = next_cpu; | |
500 | ||
501 | return next ? iter : NULL; | |
502 | } | |
503 | ||
504 | static void notrace * | |
505 | s_next(struct seq_file *m, void *v, loff_t *pos) | |
506 | { | |
507 | struct trace_iterator *iter = m->private; | |
508 | void *ent; | |
509 | void *last_ent = iter->ent; | |
510 | int i = (int)*pos; | |
511 | ||
512 | (*pos)++; | |
513 | ||
514 | /* can't go backwards */ | |
515 | if (iter->idx > i) | |
516 | return NULL; | |
517 | ||
518 | if (iter->idx < 0) | |
519 | ent = find_next_entry_inc(iter); | |
520 | else | |
521 | ent = iter; | |
522 | ||
523 | while (ent && iter->idx < i) | |
524 | ent = find_next_entry_inc(iter); | |
525 | ||
526 | iter->pos = *pos; | |
527 | ||
528 | if (last_ent && !ent) | |
529 | seq_puts(m, "\n\nvim:ft=help\n"); | |
530 | ||
531 | return ent; | |
532 | } | |
533 | ||
534 | static void *s_start(struct seq_file *m, loff_t *pos) | |
535 | { | |
536 | struct trace_iterator *iter = m->private; | |
537 | void *p = NULL; | |
538 | loff_t l = 0; | |
539 | int i; | |
540 | ||
541 | mutex_lock(&trace_types_lock); | |
542 | ||
543 | if (!current_trace || current_trace != iter->trace) | |
544 | return NULL; | |
545 | ||
546 | atomic_inc(&trace_record_cmdline_disabled); | |
547 | ||
548 | /* let the tracer grab locks here if needed */ | |
549 | if (current_trace->start) | |
550 | current_trace->start(iter); | |
551 | ||
552 | if (*pos != iter->pos) { | |
553 | iter->ent = NULL; | |
554 | iter->cpu = 0; | |
555 | iter->idx = -1; | |
556 | ||
557 | for (i = 0; i < NR_CPUS; i++) | |
558 | iter->next_idx[i] = 0; | |
559 | ||
560 | for (p = iter; p && l < *pos; p = s_next(m, p, &l)) | |
561 | ; | |
562 | ||
563 | } else { | |
564 | l = *pos; | |
565 | p = s_next(m, p, &l); | |
566 | } | |
567 | ||
568 | return p; | |
569 | } | |
570 | ||
571 | static void s_stop(struct seq_file *m, void *p) | |
572 | { | |
573 | struct trace_iterator *iter = m->private; | |
574 | ||
575 | atomic_dec(&trace_record_cmdline_disabled); | |
576 | ||
577 | /* let the tracer release locks here if needed */ | |
578 | if (current_trace && current_trace == iter->trace && iter->trace->stop) | |
579 | iter->trace->stop(iter); | |
580 | ||
581 | mutex_unlock(&trace_types_lock); | |
582 | } | |
583 | ||
584 | static void | |
585 | seq_print_sym_short(struct seq_file *m, const char *fmt, unsigned long address) | |
586 | { | |
587 | #ifdef CONFIG_KALLSYMS | |
588 | char str[KSYM_SYMBOL_LEN]; | |
589 | ||
590 | kallsyms_lookup(address, NULL, NULL, NULL, str); | |
591 | ||
592 | seq_printf(m, fmt, str); | |
593 | #endif | |
594 | } | |
595 | ||
596 | static void | |
597 | seq_print_sym_offset(struct seq_file *m, const char *fmt, unsigned long address) | |
598 | { | |
599 | #ifdef CONFIG_KALLSYMS | |
600 | char str[KSYM_SYMBOL_LEN]; | |
601 | ||
602 | sprint_symbol(str, address); | |
603 | seq_printf(m, fmt, str); | |
604 | #endif | |
605 | } | |
606 | ||
607 | #ifndef CONFIG_64BIT | |
608 | # define IP_FMT "%08lx" | |
609 | #else | |
610 | # define IP_FMT "%016lx" | |
611 | #endif | |
612 | ||
613 | static void notrace | |
614 | seq_print_ip_sym(struct seq_file *m, unsigned long ip, unsigned long sym_flags) | |
615 | { | |
616 | if (!ip) { | |
617 | seq_printf(m, "0"); | |
618 | return; | |
619 | } | |
620 | ||
621 | if (sym_flags & TRACE_ITER_SYM_OFFSET) | |
622 | seq_print_sym_offset(m, "%s", ip); | |
623 | else | |
624 | seq_print_sym_short(m, "%s", ip); | |
625 | ||
626 | if (sym_flags & TRACE_ITER_SYM_ADDR) | |
627 | seq_printf(m, " <" IP_FMT ">", ip); | |
628 | } | |
629 | ||
630 | static void notrace print_lat_help_header(struct seq_file *m) | |
631 | { | |
632 | seq_puts(m, "# _------=> CPU# \n"); | |
633 | seq_puts(m, "# / _-----=> irqs-off \n"); | |
634 | seq_puts(m, "# | / _----=> need-resched \n"); | |
635 | seq_puts(m, "# || / _---=> hardirq/softirq \n"); | |
636 | seq_puts(m, "# ||| / _--=> preempt-depth \n"); | |
637 | seq_puts(m, "# |||| / \n"); | |
638 | seq_puts(m, "# ||||| delay \n"); | |
639 | seq_puts(m, "# cmd pid ||||| time | caller \n"); | |
640 | seq_puts(m, "# \\ / ||||| \\ | / \n"); | |
641 | } | |
642 | ||
643 | static void notrace print_func_help_header(struct seq_file *m) | |
644 | { | |
645 | seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); | |
646 | seq_puts(m, "# | | | | |\n"); | |
647 | } | |
648 | ||
649 | ||
650 | static void notrace | |
651 | print_trace_header(struct seq_file *m, struct trace_iterator *iter) | |
652 | { | |
653 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); | |
654 | struct trace_array *tr = iter->tr; | |
655 | struct trace_array_cpu *data = tr->data[tr->cpu]; | |
656 | struct tracer *type = current_trace; | |
657 | unsigned long underruns = 0; | |
658 | unsigned long underrun; | |
659 | unsigned long entries = 0; | |
660 | int cpu; | |
661 | const char *name = "preemption"; | |
662 | ||
663 | if (type) | |
664 | name = type->name; | |
665 | ||
666 | for_each_possible_cpu(cpu) { | |
667 | if (tr->data[cpu]->trace) { | |
668 | underrun = atomic_read(&tr->data[cpu]->underrun); | |
669 | if (underrun) { | |
670 | underruns += underrun; | |
671 | entries += tr->entries; | |
672 | } else | |
673 | entries += tr->data[cpu]->trace_idx; | |
674 | } | |
675 | } | |
676 | ||
677 | seq_printf(m, "%s latency trace v1.1.5 on %s\n", | |
678 | name, UTS_RELEASE); | |
679 | seq_puts(m, "-----------------------------------" | |
680 | "---------------------------------\n"); | |
681 | seq_printf(m, " latency: %lu us, #%lu/%lu, CPU#%d |" | |
682 | " (M:%s VP:%d, KP:%d, SP:%d HP:%d", | |
683 | data->saved_latency, | |
684 | entries, | |
685 | (entries + underruns), | |
686 | tr->cpu, | |
687 | #if defined(CONFIG_PREEMPT_NONE) | |
688 | "server", | |
689 | #elif defined(CONFIG_PREEMPT_VOLUNTARY) | |
690 | "desktop", | |
691 | #elif defined(CONFIG_PREEMPT_DESKTOP) | |
692 | "preempt", | |
693 | #else | |
694 | "unknown", | |
695 | #endif | |
696 | /* These are reserved for later use */ | |
697 | 0, 0, 0, 0); | |
698 | #ifdef CONFIG_SMP | |
699 | seq_printf(m, " #P:%d)\n", num_online_cpus()); | |
700 | #else | |
701 | seq_puts(m, ")\n"); | |
702 | #endif | |
703 | seq_puts(m, " -----------------\n"); | |
704 | seq_printf(m, " | task: %.16s-%d " | |
705 | "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n", | |
706 | data->comm, data->pid, data->uid, data->nice, | |
707 | data->policy, data->rt_priority); | |
708 | seq_puts(m, " -----------------\n"); | |
709 | ||
710 | if (data->critical_start) { | |
711 | seq_puts(m, " => started at: "); | |
712 | seq_print_ip_sym(m, data->critical_start, sym_flags); | |
713 | seq_puts(m, "\n => ended at: "); | |
714 | seq_print_ip_sym(m, data->critical_end, sym_flags); | |
715 | seq_puts(m, "\n"); | |
716 | } | |
717 | ||
718 | seq_puts(m, "\n"); | |
719 | } | |
720 | ||
721 | unsigned long nsecs_to_usecs(unsigned long nsecs) | |
722 | { | |
723 | return nsecs / 1000; | |
724 | } | |
725 | ||
726 | static void notrace | |
727 | lat_print_generic(struct seq_file *m, struct trace_entry *entry, int cpu) | |
728 | { | |
729 | int hardirq, softirq; | |
730 | char *comm; | |
731 | ||
732 | comm = trace_find_cmdline(entry->pid); | |
733 | ||
734 | seq_printf(m, "%8.8s-%-5d ", comm, entry->pid); | |
735 | seq_printf(m, "%d", cpu); | |
736 | seq_printf(m, "%c%c", | |
737 | (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.', | |
738 | ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.')); | |
739 | ||
740 | hardirq = entry->flags & TRACE_FLAG_HARDIRQ; | |
741 | softirq = entry->flags & TRACE_FLAG_SOFTIRQ; | |
742 | if (hardirq && softirq) | |
743 | seq_putc(m, 'H'); | |
744 | else { | |
745 | if (hardirq) | |
746 | seq_putc(m, 'h'); | |
747 | else { | |
748 | if (softirq) | |
749 | seq_putc(m, 's'); | |
750 | else | |
751 | seq_putc(m, '.'); | |
752 | } | |
753 | } | |
754 | ||
755 | if (entry->preempt_count) | |
756 | seq_printf(m, "%x", entry->preempt_count); | |
757 | else | |
758 | seq_puts(m, "."); | |
759 | } | |
760 | ||
761 | unsigned long preempt_mark_thresh = 100; | |
762 | ||
763 | static void notrace | |
764 | lat_print_timestamp(struct seq_file *m, unsigned long long abs_usecs, | |
765 | unsigned long rel_usecs) | |
766 | { | |
767 | seq_printf(m, " %4lldus", abs_usecs); | |
768 | if (rel_usecs > preempt_mark_thresh) | |
769 | seq_puts(m, "!: "); | |
770 | else if (rel_usecs > 1) | |
771 | seq_puts(m, "+: "); | |
772 | else | |
773 | seq_puts(m, " : "); | |
774 | } | |
775 | ||
776 | static const char state_to_char[] = TASK_STATE_TO_CHAR_STR; | |
777 | ||
778 | static void notrace | |
779 | print_lat_fmt(struct seq_file *m, struct trace_iterator *iter, | |
780 | unsigned int trace_idx, int cpu) | |
781 | { | |
782 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); | |
783 | struct trace_entry *next_entry = find_next_entry(iter, NULL); | |
784 | unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE); | |
785 | struct trace_entry *entry = iter->ent; | |
786 | unsigned long abs_usecs; | |
787 | unsigned long rel_usecs; | |
788 | char *comm; | |
789 | int S; | |
790 | ||
791 | if (!next_entry) | |
792 | next_entry = entry; | |
793 | rel_usecs = ns2usecs(next_entry->t - entry->t); | |
794 | abs_usecs = ns2usecs(entry->t - iter->tr->time_start); | |
795 | ||
796 | if (verbose) { | |
797 | comm = trace_find_cmdline(entry->pid); | |
798 | seq_printf(m, "%16s %5d %d %d %08x %08x [%08lx]" | |
799 | " %ld.%03ldms (+%ld.%03ldms): ", | |
800 | comm, | |
801 | entry->pid, cpu, entry->flags, | |
802 | entry->preempt_count, trace_idx, | |
803 | ns2usecs(entry->t), | |
804 | abs_usecs/1000, | |
805 | abs_usecs % 1000, rel_usecs/1000, rel_usecs % 1000); | |
806 | } else { | |
807 | lat_print_generic(m, entry, cpu); | |
808 | lat_print_timestamp(m, abs_usecs, rel_usecs); | |
809 | } | |
810 | switch (entry->type) { | |
811 | case TRACE_FN: | |
812 | seq_print_ip_sym(m, entry->fn.ip, sym_flags); | |
813 | seq_puts(m, " ("); | |
814 | seq_print_ip_sym(m, entry->fn.parent_ip, sym_flags); | |
815 | seq_puts(m, ")\n"); | |
816 | break; | |
817 | case TRACE_CTX: | |
818 | S = entry->ctx.prev_state < sizeof(state_to_char) ? | |
819 | state_to_char[entry->ctx.prev_state] : 'X'; | |
820 | comm = trace_find_cmdline(entry->ctx.next_pid); | |
821 | seq_printf(m, " %d:%d:%c --> %d:%d %s\n", | |
822 | entry->ctx.prev_pid, | |
823 | entry->ctx.prev_prio, | |
824 | S, | |
825 | entry->ctx.next_pid, | |
826 | entry->ctx.next_prio, | |
827 | comm); | |
828 | break; | |
829 | } | |
830 | } | |
831 | ||
832 | static void notrace | |
833 | print_trace_fmt(struct seq_file *m, struct trace_iterator *iter) | |
834 | { | |
835 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); | |
836 | struct trace_entry *entry = iter->ent; | |
837 | unsigned long usec_rem; | |
838 | unsigned long long t; | |
839 | unsigned long secs; | |
840 | char *comm; | |
841 | int S; | |
842 | ||
843 | comm = trace_find_cmdline(iter->ent->pid); | |
844 | ||
845 | t = ns2usecs(entry->t); | |
846 | usec_rem = do_div(t, 1000000ULL); | |
847 | secs = (unsigned long)t; | |
848 | ||
849 | seq_printf(m, "%16s-%-5d ", comm, entry->pid); | |
850 | seq_printf(m, "[%02d] ", iter->cpu); | |
851 | seq_printf(m, "%5lu.%06lu: ", secs, usec_rem); | |
852 | ||
853 | switch (entry->type) { | |
854 | case TRACE_FN: | |
855 | seq_print_ip_sym(m, entry->fn.ip, sym_flags); | |
856 | if ((sym_flags & TRACE_ITER_PRINT_PARENT) && | |
857 | entry->fn.parent_ip) { | |
858 | seq_printf(m, " <-"); | |
859 | seq_print_ip_sym(m, entry->fn.parent_ip, sym_flags); | |
860 | } | |
861 | break; | |
862 | case TRACE_CTX: | |
863 | S = entry->ctx.prev_state < sizeof(state_to_char) ? | |
864 | state_to_char[entry->ctx.prev_state] : 'X'; | |
865 | seq_printf(m, " %d:%d:%c ==> %d:%d\n", | |
866 | entry->ctx.prev_pid, | |
867 | entry->ctx.prev_prio, | |
868 | S, | |
869 | entry->ctx.next_pid, | |
870 | entry->ctx.next_prio); | |
871 | break; | |
872 | } | |
873 | seq_printf(m, "\n"); | |
874 | } | |
875 | ||
876 | static int trace_empty(struct trace_iterator *iter) | |
877 | { | |
878 | struct trace_array_cpu *data; | |
879 | int cpu; | |
880 | ||
881 | for_each_possible_cpu(cpu) { | |
882 | data = iter->tr->data[cpu]; | |
883 | ||
884 | if (data->trace && | |
885 | (data->trace_idx || | |
886 | atomic_read(&data->underrun))) | |
887 | return 0; | |
888 | } | |
889 | return 1; | |
890 | } | |
891 | ||
892 | static int s_show(struct seq_file *m, void *v) | |
893 | { | |
894 | struct trace_iterator *iter = v; | |
895 | ||
896 | if (iter->ent == NULL) { | |
897 | if (iter->tr) { | |
898 | seq_printf(m, "# tracer: %s\n", iter->trace->name); | |
899 | seq_puts(m, "#\n"); | |
900 | } | |
901 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) { | |
902 | /* print nothing if the buffers are empty */ | |
903 | if (trace_empty(iter)) | |
904 | return 0; | |
905 | print_trace_header(m, iter); | |
906 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
907 | print_lat_help_header(m); | |
908 | } else { | |
909 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
910 | print_func_help_header(m); | |
911 | } | |
912 | } else { | |
913 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) | |
914 | print_lat_fmt(m, iter, iter->idx, iter->cpu); | |
915 | else | |
916 | print_trace_fmt(m, iter); | |
917 | } | |
918 | ||
919 | return 0; | |
920 | } | |
921 | ||
922 | static struct seq_operations tracer_seq_ops = { | |
923 | .start = s_start, | |
924 | .next = s_next, | |
925 | .stop = s_stop, | |
926 | .show = s_show, | |
927 | }; | |
928 | ||
929 | static struct trace_iterator notrace * | |
930 | __tracing_open(struct inode *inode, struct file *file, int *ret) | |
931 | { | |
932 | struct trace_iterator *iter; | |
933 | ||
934 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
935 | if (!iter) { | |
936 | *ret = -ENOMEM; | |
937 | goto out; | |
938 | } | |
939 | ||
940 | mutex_lock(&trace_types_lock); | |
941 | if (current_trace && current_trace->print_max) | |
942 | iter->tr = &max_tr; | |
943 | else | |
944 | iter->tr = inode->i_private; | |
945 | iter->trace = current_trace; | |
946 | iter->pos = -1; | |
947 | ||
948 | /* TODO stop tracer */ | |
949 | *ret = seq_open(file, &tracer_seq_ops); | |
950 | if (!*ret) { | |
951 | struct seq_file *m = file->private_data; | |
952 | m->private = iter; | |
953 | ||
954 | /* stop the trace while dumping */ | |
955 | if (iter->tr->ctrl) | |
956 | tracer_enabled = 0; | |
957 | ||
958 | if (iter->trace && iter->trace->open) | |
959 | iter->trace->open(iter); | |
960 | } else { | |
961 | kfree(iter); | |
962 | iter = NULL; | |
963 | } | |
964 | mutex_unlock(&trace_types_lock); | |
965 | ||
966 | out: | |
967 | return iter; | |
968 | } | |
969 | ||
970 | int tracing_open_generic(struct inode *inode, struct file *filp) | |
971 | { | |
972 | filp->private_data = inode->i_private; | |
973 | return 0; | |
974 | } | |
975 | ||
976 | int tracing_release(struct inode *inode, struct file *file) | |
977 | { | |
978 | struct seq_file *m = (struct seq_file *)file->private_data; | |
979 | struct trace_iterator *iter = m->private; | |
980 | ||
981 | mutex_lock(&trace_types_lock); | |
982 | if (iter->trace && iter->trace->close) | |
983 | iter->trace->close(iter); | |
984 | ||
985 | /* reenable tracing if it was previously enabled */ | |
986 | if (iter->tr->ctrl) | |
987 | tracer_enabled = 1; | |
988 | mutex_unlock(&trace_types_lock); | |
989 | ||
990 | seq_release(inode, file); | |
991 | kfree(iter); | |
992 | return 0; | |
993 | } | |
994 | ||
995 | static int tracing_open(struct inode *inode, struct file *file) | |
996 | { | |
997 | int ret; | |
998 | ||
999 | __tracing_open(inode, file, &ret); | |
1000 | ||
1001 | return ret; | |
1002 | } | |
1003 | ||
1004 | static int tracing_lt_open(struct inode *inode, struct file *file) | |
1005 | { | |
1006 | struct trace_iterator *iter; | |
1007 | int ret; | |
1008 | ||
1009 | iter = __tracing_open(inode, file, &ret); | |
1010 | ||
1011 | if (!ret) | |
1012 | iter->iter_flags |= TRACE_FILE_LAT_FMT; | |
1013 | ||
1014 | return ret; | |
1015 | } | |
1016 | ||
1017 | ||
1018 | static void notrace * | |
1019 | t_next(struct seq_file *m, void *v, loff_t *pos) | |
1020 | { | |
1021 | struct tracer *t = m->private; | |
1022 | ||
1023 | (*pos)++; | |
1024 | ||
1025 | if (t) | |
1026 | t = t->next; | |
1027 | ||
1028 | m->private = t; | |
1029 | ||
1030 | return t; | |
1031 | } | |
1032 | ||
1033 | static void *t_start(struct seq_file *m, loff_t *pos) | |
1034 | { | |
1035 | struct tracer *t = m->private; | |
1036 | loff_t l = 0; | |
1037 | ||
1038 | mutex_lock(&trace_types_lock); | |
1039 | for (; t && l < *pos; t = t_next(m, t, &l)) | |
1040 | ; | |
1041 | ||
1042 | return t; | |
1043 | } | |
1044 | ||
1045 | static void t_stop(struct seq_file *m, void *p) | |
1046 | { | |
1047 | mutex_unlock(&trace_types_lock); | |
1048 | } | |
1049 | ||
1050 | static int t_show(struct seq_file *m, void *v) | |
1051 | { | |
1052 | struct tracer *t = v; | |
1053 | ||
1054 | if (!t) | |
1055 | return 0; | |
1056 | ||
1057 | seq_printf(m, "%s", t->name); | |
1058 | if (t->next) | |
1059 | seq_putc(m, ' '); | |
1060 | else | |
1061 | seq_putc(m, '\n'); | |
1062 | ||
1063 | return 0; | |
1064 | } | |
1065 | ||
1066 | static struct seq_operations show_traces_seq_ops = { | |
1067 | .start = t_start, | |
1068 | .next = t_next, | |
1069 | .stop = t_stop, | |
1070 | .show = t_show, | |
1071 | }; | |
1072 | ||
1073 | static int show_traces_open(struct inode *inode, struct file *file) | |
1074 | { | |
1075 | int ret; | |
1076 | ||
1077 | ret = seq_open(file, &show_traces_seq_ops); | |
1078 | if (!ret) { | |
1079 | struct seq_file *m = file->private_data; | |
1080 | m->private = trace_types; | |
1081 | } | |
1082 | ||
1083 | return ret; | |
1084 | } | |
1085 | ||
1086 | static struct file_operations tracing_fops = { | |
1087 | .open = tracing_open, | |
1088 | .read = seq_read, | |
1089 | .llseek = seq_lseek, | |
1090 | .release = tracing_release, | |
1091 | }; | |
1092 | ||
1093 | static struct file_operations tracing_lt_fops = { | |
1094 | .open = tracing_lt_open, | |
1095 | .read = seq_read, | |
1096 | .llseek = seq_lseek, | |
1097 | .release = tracing_release, | |
1098 | }; | |
1099 | ||
1100 | static struct file_operations show_traces_fops = { | |
1101 | .open = show_traces_open, | |
1102 | .read = seq_read, | |
1103 | .release = seq_release, | |
1104 | }; | |
1105 | ||
1106 | static ssize_t | |
1107 | tracing_iter_ctrl_read(struct file *filp, char __user *ubuf, | |
1108 | size_t cnt, loff_t *ppos) | |
1109 | { | |
1110 | char *buf; | |
1111 | int r = 0; | |
1112 | int len = 0; | |
1113 | int i; | |
1114 | ||
1115 | /* calulate max size */ | |
1116 | for (i = 0; trace_options[i]; i++) { | |
1117 | len += strlen(trace_options[i]); | |
1118 | len += 3; /* "no" and space */ | |
1119 | } | |
1120 | ||
1121 | /* +2 for \n and \0 */ | |
1122 | buf = kmalloc(len + 2, GFP_KERNEL); | |
1123 | if (!buf) | |
1124 | return -ENOMEM; | |
1125 | ||
1126 | for (i = 0; trace_options[i]; i++) { | |
1127 | if (trace_flags & (1 << i)) | |
1128 | r += sprintf(buf + r, "%s ", trace_options[i]); | |
1129 | else | |
1130 | r += sprintf(buf + r, "no%s ", trace_options[i]); | |
1131 | } | |
1132 | ||
1133 | r += sprintf(buf + r, "\n"); | |
1134 | WARN_ON(r >= len + 2); | |
1135 | ||
1136 | r = simple_read_from_buffer(ubuf, cnt, ppos, | |
1137 | buf, r); | |
1138 | ||
1139 | kfree(buf); | |
1140 | ||
1141 | return r; | |
1142 | } | |
1143 | ||
1144 | static ssize_t | |
1145 | tracing_iter_ctrl_write(struct file *filp, const char __user *ubuf, | |
1146 | size_t cnt, loff_t *ppos) | |
1147 | { | |
1148 | char buf[64]; | |
1149 | char *cmp = buf; | |
1150 | int neg = 0; | |
1151 | int i; | |
1152 | ||
1153 | if (cnt > 63) | |
1154 | cnt = 63; | |
1155 | ||
1156 | if (copy_from_user(&buf, ubuf, cnt)) | |
1157 | return -EFAULT; | |
1158 | ||
1159 | buf[cnt] = 0; | |
1160 | ||
1161 | if (strncmp(buf, "no", 2) == 0) { | |
1162 | neg = 1; | |
1163 | cmp += 2; | |
1164 | } | |
1165 | ||
1166 | for (i = 0; trace_options[i]; i++) { | |
1167 | int len = strlen(trace_options[i]); | |
1168 | ||
1169 | if (strncmp(cmp, trace_options[i], len) == 0) { | |
1170 | if (neg) | |
1171 | trace_flags &= ~(1 << i); | |
1172 | else | |
1173 | trace_flags |= (1 << i); | |
1174 | break; | |
1175 | } | |
1176 | } | |
1177 | ||
1178 | filp->f_pos += cnt; | |
1179 | ||
1180 | return cnt; | |
1181 | } | |
1182 | ||
1183 | static struct file_operations tracing_iter_fops = { | |
1184 | .open = tracing_open_generic, | |
1185 | .read = tracing_iter_ctrl_read, | |
1186 | .write = tracing_iter_ctrl_write, | |
1187 | }; | |
1188 | ||
1189 | static ssize_t | |
1190 | tracing_ctrl_read(struct file *filp, char __user *ubuf, | |
1191 | size_t cnt, loff_t *ppos) | |
1192 | { | |
1193 | struct trace_array *tr = filp->private_data; | |
1194 | char buf[64]; | |
1195 | int r; | |
1196 | ||
1197 | r = sprintf(buf, "%ld\n", tr->ctrl); | |
1198 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
1199 | buf, r); | |
1200 | } | |
1201 | ||
1202 | static ssize_t | |
1203 | tracing_ctrl_write(struct file *filp, const char __user *ubuf, | |
1204 | size_t cnt, loff_t *ppos) | |
1205 | { | |
1206 | struct trace_array *tr = filp->private_data; | |
1207 | long val; | |
1208 | char buf[64]; | |
1209 | ||
1210 | if (cnt > 63) | |
1211 | cnt = 63; | |
1212 | ||
1213 | if (copy_from_user(&buf, ubuf, cnt)) | |
1214 | return -EFAULT; | |
1215 | ||
1216 | buf[cnt] = 0; | |
1217 | ||
1218 | val = simple_strtoul(buf, NULL, 10); | |
1219 | ||
1220 | val = !!val; | |
1221 | ||
1222 | mutex_lock(&trace_types_lock); | |
1223 | if (tr->ctrl ^ val) { | |
1224 | if (val) | |
1225 | tracer_enabled = 1; | |
1226 | else | |
1227 | tracer_enabled = 0; | |
1228 | ||
1229 | tr->ctrl = val; | |
1230 | ||
1231 | if (current_trace && current_trace->ctrl_update) | |
1232 | current_trace->ctrl_update(tr); | |
1233 | } | |
1234 | mutex_unlock(&trace_types_lock); | |
1235 | ||
1236 | filp->f_pos += cnt; | |
1237 | ||
1238 | return cnt; | |
1239 | } | |
1240 | ||
1241 | static ssize_t | |
1242 | tracing_set_trace_read(struct file *filp, char __user *ubuf, | |
1243 | size_t cnt, loff_t *ppos) | |
1244 | { | |
1245 | char buf[max_tracer_type_len+2]; | |
1246 | int r; | |
1247 | ||
1248 | mutex_lock(&trace_types_lock); | |
1249 | if (current_trace) | |
1250 | r = sprintf(buf, "%s\n", current_trace->name); | |
1251 | else | |
1252 | r = sprintf(buf, "\n"); | |
1253 | mutex_unlock(&trace_types_lock); | |
1254 | ||
1255 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
1256 | buf, r); | |
1257 | } | |
1258 | ||
1259 | static ssize_t | |
1260 | tracing_set_trace_write(struct file *filp, const char __user *ubuf, | |
1261 | size_t cnt, loff_t *ppos) | |
1262 | { | |
1263 | struct trace_array *tr = &global_trace; | |
1264 | struct tracer *t; | |
1265 | char buf[max_tracer_type_len+1]; | |
1266 | int i; | |
1267 | ||
1268 | if (cnt > max_tracer_type_len) | |
1269 | cnt = max_tracer_type_len; | |
1270 | ||
1271 | if (copy_from_user(&buf, ubuf, cnt)) | |
1272 | return -EFAULT; | |
1273 | ||
1274 | buf[cnt] = 0; | |
1275 | ||
1276 | /* strip ending whitespace. */ | |
1277 | for (i = cnt - 1; i > 0 && isspace(buf[i]); i--) | |
1278 | buf[i] = 0; | |
1279 | ||
1280 | mutex_lock(&trace_types_lock); | |
1281 | for (t = trace_types; t; t = t->next) { | |
1282 | if (strcmp(t->name, buf) == 0) | |
1283 | break; | |
1284 | } | |
1285 | if (!t || t == current_trace) | |
1286 | goto out; | |
1287 | ||
1288 | if (current_trace && current_trace->reset) | |
1289 | current_trace->reset(tr); | |
1290 | ||
1291 | current_trace = t; | |
1292 | if (t->init) | |
1293 | t->init(tr); | |
1294 | ||
1295 | out: | |
1296 | mutex_unlock(&trace_types_lock); | |
1297 | ||
1298 | filp->f_pos += cnt; | |
1299 | ||
1300 | return cnt; | |
1301 | } | |
1302 | ||
1303 | static ssize_t | |
1304 | tracing_max_lat_read(struct file *filp, char __user *ubuf, | |
1305 | size_t cnt, loff_t *ppos) | |
1306 | { | |
1307 | unsigned long *ptr = filp->private_data; | |
1308 | char buf[64]; | |
1309 | int r; | |
1310 | ||
1311 | r = snprintf(buf, 64, "%ld\n", | |
1312 | *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr)); | |
1313 | if (r > 64) | |
1314 | r = 64; | |
1315 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
1316 | buf, r); | |
1317 | } | |
1318 | ||
1319 | static ssize_t | |
1320 | tracing_max_lat_write(struct file *filp, const char __user *ubuf, | |
1321 | size_t cnt, loff_t *ppos) | |
1322 | { | |
1323 | long *ptr = filp->private_data; | |
1324 | long val; | |
1325 | char buf[64]; | |
1326 | ||
1327 | if (cnt > 63) | |
1328 | cnt = 63; | |
1329 | ||
1330 | if (copy_from_user(&buf, ubuf, cnt)) | |
1331 | return -EFAULT; | |
1332 | ||
1333 | buf[cnt] = 0; | |
1334 | ||
1335 | val = simple_strtoul(buf, NULL, 10); | |
1336 | ||
1337 | *ptr = val * 1000; | |
1338 | ||
1339 | return cnt; | |
1340 | } | |
1341 | ||
1342 | static struct file_operations tracing_max_lat_fops = { | |
1343 | .open = tracing_open_generic, | |
1344 | .read = tracing_max_lat_read, | |
1345 | .write = tracing_max_lat_write, | |
1346 | }; | |
1347 | ||
1348 | static struct file_operations tracing_ctrl_fops = { | |
1349 | .open = tracing_open_generic, | |
1350 | .read = tracing_ctrl_read, | |
1351 | .write = tracing_ctrl_write, | |
1352 | }; | |
1353 | ||
1354 | static struct file_operations set_tracer_fops = { | |
1355 | .open = tracing_open_generic, | |
1356 | .read = tracing_set_trace_read, | |
1357 | .write = tracing_set_trace_write, | |
1358 | }; | |
1359 | ||
1360 | #ifdef CONFIG_DYNAMIC_FTRACE | |
1361 | ||
1362 | static ssize_t | |
1363 | tracing_read_long(struct file *filp, char __user *ubuf, | |
1364 | size_t cnt, loff_t *ppos) | |
1365 | { | |
1366 | unsigned long *p = filp->private_data; | |
1367 | char buf[64]; | |
1368 | int r; | |
1369 | ||
1370 | r = sprintf(buf, "%ld\n", *p); | |
1371 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
1372 | buf, r); | |
1373 | } | |
1374 | ||
1375 | static struct file_operations tracing_read_long_fops = { | |
1376 | .open = tracing_open_generic, | |
1377 | .read = tracing_read_long, | |
1378 | }; | |
1379 | #endif | |
1380 | ||
1381 | static struct dentry *d_tracer; | |
1382 | ||
1383 | struct dentry *tracing_init_dentry(void) | |
1384 | { | |
1385 | static int once; | |
1386 | ||
1387 | if (d_tracer) | |
1388 | return d_tracer; | |
1389 | ||
1390 | d_tracer = debugfs_create_dir("tracing", NULL); | |
1391 | ||
1392 | if (!d_tracer && !once) { | |
1393 | once = 1; | |
1394 | pr_warning("Could not create debugfs directory 'tracing'\n"); | |
1395 | return NULL; | |
1396 | } | |
1397 | ||
1398 | return d_tracer; | |
1399 | } | |
1400 | ||
1401 | static __init void tracer_init_debugfs(void) | |
1402 | { | |
1403 | struct dentry *d_tracer; | |
1404 | struct dentry *entry; | |
1405 | ||
1406 | d_tracer = tracing_init_dentry(); | |
1407 | ||
1408 | entry = debugfs_create_file("tracing_enabled", 0644, d_tracer, | |
1409 | &global_trace, &tracing_ctrl_fops); | |
1410 | if (!entry) | |
1411 | pr_warning("Could not create debugfs 'tracing_enabled' entry\n"); | |
1412 | ||
1413 | entry = debugfs_create_file("iter_ctrl", 0644, d_tracer, | |
1414 | NULL, &tracing_iter_fops); | |
1415 | if (!entry) | |
1416 | pr_warning("Could not create debugfs 'iter_ctrl' entry\n"); | |
1417 | ||
1418 | entry = debugfs_create_file("latency_trace", 0444, d_tracer, | |
1419 | &global_trace, &tracing_lt_fops); | |
1420 | if (!entry) | |
1421 | pr_warning("Could not create debugfs 'latency_trace' entry\n"); | |
1422 | ||
1423 | entry = debugfs_create_file("trace", 0444, d_tracer, | |
1424 | &global_trace, &tracing_fops); | |
1425 | if (!entry) | |
1426 | pr_warning("Could not create debugfs 'trace' entry\n"); | |
1427 | ||
1428 | entry = debugfs_create_file("available_tracers", 0444, d_tracer, | |
1429 | &global_trace, &show_traces_fops); | |
1430 | if (!entry) | |
1431 | pr_warning("Could not create debugfs 'trace' entry\n"); | |
1432 | ||
1433 | entry = debugfs_create_file("current_tracer", 0444, d_tracer, | |
1434 | &global_trace, &set_tracer_fops); | |
1435 | if (!entry) | |
1436 | pr_warning("Could not create debugfs 'trace' entry\n"); | |
1437 | ||
1438 | entry = debugfs_create_file("tracing_max_latency", 0644, d_tracer, | |
1439 | &tracing_max_latency, | |
1440 | &tracing_max_lat_fops); | |
1441 | if (!entry) | |
1442 | pr_warning("Could not create debugfs " | |
1443 | "'tracing_max_latency' entry\n"); | |
1444 | ||
1445 | entry = debugfs_create_file("tracing_thresh", 0644, d_tracer, | |
1446 | &tracing_thresh, &tracing_max_lat_fops); | |
1447 | if (!entry) | |
1448 | pr_warning("Could not create debugfs " | |
1449 | "'tracing_threash' entry\n"); | |
1450 | ||
1451 | #ifdef CONFIG_DYNAMIC_FTRACE | |
1452 | entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer, | |
1453 | &ftrace_update_tot_cnt, | |
1454 | &tracing_read_long_fops); | |
1455 | if (!entry) | |
1456 | pr_warning("Could not create debugfs " | |
1457 | "'dyn_ftrace_total_info' entry\n"); | |
1458 | #endif | |
1459 | } | |
1460 | ||
1461 | /* dummy trace to disable tracing */ | |
1462 | static struct tracer no_tracer __read_mostly = | |
1463 | { | |
1464 | .name = "none", | |
1465 | }; | |
1466 | ||
1467 | static inline notrace int page_order(const unsigned long size) | |
1468 | { | |
1469 | const unsigned long nr_pages = DIV_ROUND_UP(size, PAGE_SIZE); | |
1470 | return ilog2(roundup_pow_of_two(nr_pages)); | |
1471 | } | |
1472 | ||
1473 | __init static int tracer_alloc_buffers(void) | |
1474 | { | |
1475 | const int order = page_order(trace_nr_entries * TRACE_ENTRY_SIZE); | |
1476 | const unsigned long size = (1UL << order) << PAGE_SHIFT; | |
1477 | struct trace_entry *array; | |
1478 | int i; | |
1479 | ||
1480 | for_each_possible_cpu(i) { | |
1481 | global_trace.data[i] = &per_cpu(global_trace_cpu, i); | |
1482 | max_tr.data[i] = &per_cpu(max_data, i); | |
1483 | ||
1484 | array = (struct trace_entry *) | |
1485 | __get_free_pages(GFP_KERNEL, order); | |
1486 | if (array == NULL) { | |
1487 | printk(KERN_ERR "tracer: failed to allocate" | |
1488 | " %ld bytes for trace buffer!\n", size); | |
1489 | goto free_buffers; | |
1490 | } | |
1491 | global_trace.data[i]->trace = array; | |
1492 | ||
1493 | /* Only allocate if we are actually using the max trace */ | |
1494 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1495 | array = (struct trace_entry *) | |
1496 | __get_free_pages(GFP_KERNEL, order); | |
1497 | if (array == NULL) { | |
1498 | printk(KERN_ERR "wakeup tracer: failed to allocate" | |
1499 | " %ld bytes for trace buffer!\n", size); | |
1500 | goto free_buffers; | |
1501 | } | |
1502 | max_tr.data[i]->trace = array; | |
1503 | #endif | |
1504 | } | |
1505 | ||
1506 | /* | |
1507 | * Since we allocate by orders of pages, we may be able to | |
1508 | * round up a bit. | |
1509 | */ | |
1510 | global_trace.entries = size / TRACE_ENTRY_SIZE; | |
1511 | max_tr.entries = global_trace.entries; | |
1512 | ||
1513 | pr_info("tracer: %ld bytes allocated for %ld", | |
1514 | size, trace_nr_entries); | |
1515 | pr_info(" entries of %ld bytes\n", (long)TRACE_ENTRY_SIZE); | |
1516 | pr_info(" actual entries %ld\n", global_trace.entries); | |
1517 | ||
1518 | tracer_init_debugfs(); | |
1519 | ||
1520 | trace_init_cmdlines(); | |
1521 | ||
1522 | register_tracer(&no_tracer); | |
1523 | current_trace = &no_tracer; | |
1524 | ||
1525 | return 0; | |
1526 | ||
1527 | free_buffers: | |
1528 | for (i-- ; i >= 0; i--) { | |
1529 | struct trace_array_cpu *data = global_trace.data[i]; | |
1530 | ||
1531 | if (data && data->trace) { | |
1532 | free_pages((unsigned long)data->trace, order); | |
1533 | data->trace = NULL; | |
1534 | } | |
1535 | ||
1536 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1537 | data = max_tr.data[i]; | |
1538 | if (data && data->trace) { | |
1539 | free_pages((unsigned long)data->trace, order); | |
1540 | data->trace = NULL; | |
1541 | } | |
1542 | #endif | |
1543 | } | |
1544 | return -ENOMEM; | |
1545 | } | |
1546 | ||
1547 | device_initcall(tracer_alloc_buffers); |