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Commit | Line | Data |
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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> | |
4c11d7ae | 18 | #include <linux/pagemap.h> |
bc0c38d1 SR |
19 | #include <linux/hardirq.h> |
20 | #include <linux/linkage.h> | |
21 | #include <linux/uaccess.h> | |
22 | #include <linux/ftrace.h> | |
23 | #include <linux/module.h> | |
24 | #include <linux/percpu.h> | |
25 | #include <linux/ctype.h> | |
26 | #include <linux/init.h> | |
27 | #include <linux/gfp.h> | |
28 | #include <linux/fs.h> | |
29 | ||
30 | #include "trace.h" | |
31 | ||
32 | unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX; | |
33 | unsigned long __read_mostly tracing_thresh; | |
34 | ||
60a11774 SR |
35 | static int tracing_disabled = 1; |
36 | ||
bc0c38d1 SR |
37 | static long notrace |
38 | ns2usecs(cycle_t nsec) | |
39 | { | |
40 | nsec += 500; | |
41 | do_div(nsec, 1000); | |
42 | return nsec; | |
43 | } | |
44 | ||
45 | static atomic_t tracer_counter; | |
46 | static struct trace_array global_trace; | |
47 | ||
48 | static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu); | |
49 | ||
50 | static struct trace_array max_tr; | |
51 | ||
52 | static DEFINE_PER_CPU(struct trace_array_cpu, max_data); | |
53 | ||
54 | static int tracer_enabled; | |
4c11d7ae | 55 | static unsigned long trace_nr_entries = 16384UL; |
bc0c38d1 SR |
56 | |
57 | static struct tracer *trace_types __read_mostly; | |
58 | static struct tracer *current_trace __read_mostly; | |
59 | static int max_tracer_type_len; | |
60 | ||
61 | static DEFINE_MUTEX(trace_types_lock); | |
62 | ||
4c11d7ae SR |
63 | #define ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(struct trace_entry)) |
64 | ||
bc0c38d1 SR |
65 | static int __init set_nr_entries(char *str) |
66 | { | |
67 | if (!str) | |
68 | return 0; | |
69 | trace_nr_entries = simple_strtoul(str, &str, 0); | |
70 | return 1; | |
71 | } | |
72 | __setup("trace_entries=", set_nr_entries); | |
73 | ||
57f50be1 SR |
74 | unsigned long nsecs_to_usecs(unsigned long nsecs) |
75 | { | |
76 | return nsecs / 1000; | |
77 | } | |
78 | ||
bc0c38d1 SR |
79 | enum trace_type { |
80 | __TRACE_FIRST_TYPE = 0, | |
81 | ||
82 | TRACE_FN, | |
83 | TRACE_CTX, | |
84 | ||
85 | __TRACE_LAST_TYPE | |
86 | }; | |
87 | ||
88 | enum trace_flag_type { | |
89 | TRACE_FLAG_IRQS_OFF = 0x01, | |
90 | TRACE_FLAG_NEED_RESCHED = 0x02, | |
91 | TRACE_FLAG_HARDIRQ = 0x04, | |
92 | TRACE_FLAG_SOFTIRQ = 0x08, | |
93 | }; | |
94 | ||
95 | enum trace_iterator_flags { | |
96 | TRACE_ITER_PRINT_PARENT = 0x01, | |
97 | TRACE_ITER_SYM_OFFSET = 0x02, | |
98 | TRACE_ITER_SYM_ADDR = 0x04, | |
99 | TRACE_ITER_VERBOSE = 0x08, | |
100 | }; | |
101 | ||
102 | #define TRACE_ITER_SYM_MASK \ | |
103 | (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR) | |
104 | ||
105 | /* These must match the bit postions above */ | |
106 | static const char *trace_options[] = { | |
107 | "print-parent", | |
108 | "sym-offset", | |
109 | "sym-addr", | |
110 | "verbose", | |
111 | NULL | |
112 | }; | |
113 | ||
114 | static unsigned trace_flags; | |
115 | ||
4c11d7ae | 116 | static DEFINE_SPINLOCK(ftrace_max_lock); |
bc0c38d1 SR |
117 | |
118 | /* | |
119 | * Copy the new maximum trace into the separate maximum-trace | |
120 | * structure. (this way the maximum trace is permanently saved, | |
121 | * for later retrieval via /debugfs/tracing/latency_trace) | |
122 | */ | |
4e3c3333 | 123 | static notrace void |
bc0c38d1 SR |
124 | __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) |
125 | { | |
126 | struct trace_array_cpu *data = tr->data[cpu]; | |
127 | ||
128 | max_tr.cpu = cpu; | |
129 | max_tr.time_start = data->preempt_timestamp; | |
130 | ||
131 | data = max_tr.data[cpu]; | |
132 | data->saved_latency = tracing_max_latency; | |
133 | ||
134 | memcpy(data->comm, tsk->comm, TASK_COMM_LEN); | |
135 | data->pid = tsk->pid; | |
136 | data->uid = tsk->uid; | |
137 | data->nice = tsk->static_prio - 20 - MAX_RT_PRIO; | |
138 | data->policy = tsk->policy; | |
139 | data->rt_priority = tsk->rt_priority; | |
140 | ||
141 | /* record this tasks comm */ | |
142 | tracing_record_cmdline(current); | |
143 | } | |
144 | ||
c7aafc54 IM |
145 | void check_pages(struct trace_array_cpu *data) |
146 | { | |
147 | struct page *page, *tmp; | |
148 | ||
149 | BUG_ON(data->trace_pages.next->prev != &data->trace_pages); | |
150 | BUG_ON(data->trace_pages.prev->next != &data->trace_pages); | |
151 | ||
152 | list_for_each_entry_safe(page, tmp, &data->trace_pages, lru) { | |
153 | BUG_ON(page->lru.next->prev != &page->lru); | |
154 | BUG_ON(page->lru.prev->next != &page->lru); | |
155 | } | |
156 | } | |
157 | ||
158 | void *head_page(struct trace_array_cpu *data) | |
159 | { | |
160 | struct page *page; | |
161 | ||
162 | check_pages(data); | |
163 | if (list_empty(&data->trace_pages)) | |
164 | return NULL; | |
165 | ||
166 | page = list_entry(data->trace_pages.next, struct page, lru); | |
167 | BUG_ON(&page->lru == &data->trace_pages); | |
168 | ||
169 | return page_address(page); | |
170 | } | |
171 | ||
214023c3 SR |
172 | static notrace int |
173 | trace_seq_printf(struct trace_seq *s, const char *fmt, ...) | |
174 | { | |
175 | int len = (PAGE_SIZE - 1) - s->len; | |
176 | va_list ap; | |
177 | ||
178 | if (!len) | |
179 | return 0; | |
180 | ||
181 | va_start(ap, fmt); | |
182 | len = vsnprintf(s->buffer + s->len, len, fmt, ap); | |
183 | va_end(ap); | |
184 | ||
185 | s->len += len; | |
186 | ||
187 | return len; | |
188 | } | |
189 | ||
190 | static notrace int | |
191 | trace_seq_puts(struct trace_seq *s, const char *str) | |
192 | { | |
193 | int len = strlen(str); | |
194 | ||
195 | if (len > ((PAGE_SIZE - 1) - s->len)) | |
196 | len = (PAGE_SIZE - 1) - s->len; | |
197 | ||
198 | memcpy(s->buffer + s->len, str, len); | |
199 | s->len += len; | |
200 | ||
201 | return len; | |
202 | } | |
203 | ||
204 | static notrace int | |
205 | trace_seq_putc(struct trace_seq *s, unsigned char c) | |
206 | { | |
207 | if (s->len >= (PAGE_SIZE - 1)) | |
208 | return 0; | |
209 | ||
210 | s->buffer[s->len++] = c; | |
211 | ||
212 | return 1; | |
213 | } | |
214 | ||
215 | static notrace void | |
216 | trace_seq_reset(struct trace_seq *s) | |
217 | { | |
218 | s->len = 0; | |
219 | } | |
220 | ||
221 | static notrace void | |
222 | trace_print_seq(struct seq_file *m, struct trace_seq *s) | |
223 | { | |
224 | int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len; | |
225 | ||
226 | s->buffer[len] = 0; | |
227 | seq_puts(m, s->buffer); | |
228 | ||
229 | trace_seq_reset(s); | |
230 | } | |
231 | ||
c7aafc54 IM |
232 | notrace static void |
233 | flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2) | |
234 | { | |
235 | struct list_head flip_pages; | |
236 | ||
237 | INIT_LIST_HEAD(&flip_pages); | |
238 | ||
93a588f4 | 239 | memcpy(&tr1->trace_head_idx, &tr2->trace_head_idx, |
c7aafc54 | 240 | sizeof(struct trace_array_cpu) - |
93a588f4 | 241 | offsetof(struct trace_array_cpu, trace_head_idx)); |
c7aafc54 IM |
242 | |
243 | check_pages(tr1); | |
244 | check_pages(tr2); | |
245 | list_splice_init(&tr1->trace_pages, &flip_pages); | |
246 | list_splice_init(&tr2->trace_pages, &tr1->trace_pages); | |
247 | list_splice_init(&flip_pages, &tr2->trace_pages); | |
248 | BUG_ON(!list_empty(&flip_pages)); | |
249 | check_pages(tr1); | |
250 | check_pages(tr2); | |
251 | } | |
252 | ||
bc0c38d1 SR |
253 | notrace void |
254 | update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
255 | { | |
256 | struct trace_array_cpu *data; | |
bc0c38d1 SR |
257 | int i; |
258 | ||
4c11d7ae SR |
259 | WARN_ON_ONCE(!irqs_disabled()); |
260 | spin_lock(&ftrace_max_lock); | |
bc0c38d1 SR |
261 | /* clear out all the previous traces */ |
262 | for_each_possible_cpu(i) { | |
263 | data = tr->data[i]; | |
c7aafc54 | 264 | flip_trace(max_tr.data[i], data); |
89b2f978 | 265 | tracing_reset(data); |
bc0c38d1 SR |
266 | } |
267 | ||
268 | __update_max_tr(tr, tsk, cpu); | |
4c11d7ae | 269 | spin_unlock(&ftrace_max_lock); |
bc0c38d1 SR |
270 | } |
271 | ||
272 | /** | |
273 | * update_max_tr_single - only copy one trace over, and reset the rest | |
274 | * @tr - tracer | |
275 | * @tsk - task with the latency | |
276 | * @cpu - the cpu of the buffer to copy. | |
277 | */ | |
278 | notrace void | |
279 | update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
280 | { | |
281 | struct trace_array_cpu *data = tr->data[cpu]; | |
bc0c38d1 SR |
282 | int i; |
283 | ||
4c11d7ae SR |
284 | WARN_ON_ONCE(!irqs_disabled()); |
285 | spin_lock(&ftrace_max_lock); | |
bc0c38d1 SR |
286 | for_each_possible_cpu(i) |
287 | tracing_reset(max_tr.data[i]); | |
288 | ||
c7aafc54 | 289 | flip_trace(max_tr.data[cpu], data); |
89b2f978 | 290 | tracing_reset(data); |
bc0c38d1 SR |
291 | |
292 | __update_max_tr(tr, tsk, cpu); | |
4c11d7ae | 293 | spin_unlock(&ftrace_max_lock); |
bc0c38d1 SR |
294 | } |
295 | ||
296 | int register_tracer(struct tracer *type) | |
297 | { | |
298 | struct tracer *t; | |
299 | int len; | |
300 | int ret = 0; | |
301 | ||
302 | if (!type->name) { | |
303 | pr_info("Tracer must have a name\n"); | |
304 | return -1; | |
305 | } | |
306 | ||
307 | mutex_lock(&trace_types_lock); | |
308 | for (t = trace_types; t; t = t->next) { | |
309 | if (strcmp(type->name, t->name) == 0) { | |
310 | /* already found */ | |
311 | pr_info("Trace %s already registered\n", | |
312 | type->name); | |
313 | ret = -1; | |
314 | goto out; | |
315 | } | |
316 | } | |
317 | ||
60a11774 SR |
318 | #ifdef CONFIG_FTRACE_STARTUP_TEST |
319 | if (type->selftest) { | |
320 | struct tracer *saved_tracer = current_trace; | |
321 | struct trace_array_cpu *data; | |
322 | struct trace_array *tr = &global_trace; | |
323 | int saved_ctrl = tr->ctrl; | |
324 | int i; | |
325 | /* | |
326 | * Run a selftest on this tracer. | |
327 | * Here we reset the trace buffer, and set the current | |
328 | * tracer to be this tracer. The tracer can then run some | |
329 | * internal tracing to verify that everything is in order. | |
330 | * If we fail, we do not register this tracer. | |
331 | */ | |
332 | for_each_possible_cpu(i) { | |
60a11774 | 333 | data = tr->data[i]; |
c7aafc54 IM |
334 | if (!head_page(data)) |
335 | continue; | |
60a11774 SR |
336 | tracing_reset(data); |
337 | } | |
338 | current_trace = type; | |
339 | tr->ctrl = 0; | |
340 | /* the test is responsible for initializing and enabling */ | |
341 | pr_info("Testing tracer %s: ", type->name); | |
342 | ret = type->selftest(type, tr); | |
343 | /* the test is responsible for resetting too */ | |
344 | current_trace = saved_tracer; | |
345 | tr->ctrl = saved_ctrl; | |
346 | if (ret) { | |
347 | printk(KERN_CONT "FAILED!\n"); | |
348 | goto out; | |
349 | } | |
1d4db00a SR |
350 | /* Only reset on passing, to avoid touching corrupted buffers */ |
351 | for_each_possible_cpu(i) { | |
352 | data = tr->data[i]; | |
353 | if (!head_page(data)) | |
354 | continue; | |
355 | tracing_reset(data); | |
356 | } | |
60a11774 SR |
357 | printk(KERN_CONT "PASSED\n"); |
358 | } | |
359 | #endif | |
360 | ||
bc0c38d1 SR |
361 | type->next = trace_types; |
362 | trace_types = type; | |
363 | len = strlen(type->name); | |
364 | if (len > max_tracer_type_len) | |
365 | max_tracer_type_len = len; | |
60a11774 | 366 | |
bc0c38d1 SR |
367 | out: |
368 | mutex_unlock(&trace_types_lock); | |
369 | ||
370 | return ret; | |
371 | } | |
372 | ||
373 | void unregister_tracer(struct tracer *type) | |
374 | { | |
375 | struct tracer **t; | |
376 | int len; | |
377 | ||
378 | mutex_lock(&trace_types_lock); | |
379 | for (t = &trace_types; *t; t = &(*t)->next) { | |
380 | if (*t == type) | |
381 | goto found; | |
382 | } | |
383 | pr_info("Trace %s not registered\n", type->name); | |
384 | goto out; | |
385 | ||
386 | found: | |
387 | *t = (*t)->next; | |
388 | if (strlen(type->name) != max_tracer_type_len) | |
389 | goto out; | |
390 | ||
391 | max_tracer_type_len = 0; | |
392 | for (t = &trace_types; *t; t = &(*t)->next) { | |
393 | len = strlen((*t)->name); | |
394 | if (len > max_tracer_type_len) | |
395 | max_tracer_type_len = len; | |
396 | } | |
397 | out: | |
398 | mutex_unlock(&trace_types_lock); | |
399 | } | |
400 | ||
4e3c3333 | 401 | notrace void tracing_reset(struct trace_array_cpu *data) |
bc0c38d1 SR |
402 | { |
403 | data->trace_idx = 0; | |
93a588f4 SR |
404 | data->trace_head = data->trace_tail = head_page(data); |
405 | data->trace_head_idx = 0; | |
406 | data->trace_tail_idx = 0; | |
bc0c38d1 SR |
407 | } |
408 | ||
409 | #ifdef CONFIG_FTRACE | |
4e3c3333 | 410 | static notrace void |
bc0c38d1 SR |
411 | function_trace_call(unsigned long ip, unsigned long parent_ip) |
412 | { | |
413 | struct trace_array *tr = &global_trace; | |
414 | struct trace_array_cpu *data; | |
415 | unsigned long flags; | |
416 | long disabled; | |
417 | int cpu; | |
418 | ||
419 | if (unlikely(!tracer_enabled)) | |
420 | return; | |
421 | ||
18cef379 | 422 | local_irq_save(flags); |
bc0c38d1 SR |
423 | cpu = raw_smp_processor_id(); |
424 | data = tr->data[cpu]; | |
425 | disabled = atomic_inc_return(&data->disabled); | |
426 | ||
427 | if (likely(disabled == 1)) | |
428 | ftrace(tr, data, ip, parent_ip, flags); | |
429 | ||
430 | atomic_dec(&data->disabled); | |
18cef379 | 431 | local_irq_restore(flags); |
bc0c38d1 SR |
432 | } |
433 | ||
434 | static struct ftrace_ops trace_ops __read_mostly = | |
435 | { | |
436 | .func = function_trace_call, | |
437 | }; | |
438 | #endif | |
439 | ||
440 | notrace void tracing_start_function_trace(void) | |
441 | { | |
442 | register_ftrace_function(&trace_ops); | |
443 | } | |
444 | ||
445 | notrace void tracing_stop_function_trace(void) | |
446 | { | |
447 | unregister_ftrace_function(&trace_ops); | |
448 | } | |
449 | ||
450 | #define SAVED_CMDLINES 128 | |
451 | static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; | |
452 | static unsigned map_cmdline_to_pid[SAVED_CMDLINES]; | |
453 | static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN]; | |
454 | static int cmdline_idx; | |
455 | static DEFINE_SPINLOCK(trace_cmdline_lock); | |
456 | atomic_t trace_record_cmdline_disabled; | |
457 | ||
458 | static void trace_init_cmdlines(void) | |
459 | { | |
460 | memset(&map_pid_to_cmdline, -1, sizeof(map_pid_to_cmdline)); | |
461 | memset(&map_cmdline_to_pid, -1, sizeof(map_cmdline_to_pid)); | |
462 | cmdline_idx = 0; | |
463 | } | |
464 | ||
465 | notrace void trace_stop_cmdline_recording(void); | |
466 | ||
4e3c3333 | 467 | static notrace void trace_save_cmdline(struct task_struct *tsk) |
bc0c38d1 SR |
468 | { |
469 | unsigned map; | |
470 | unsigned idx; | |
471 | ||
472 | if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT)) | |
473 | return; | |
474 | ||
475 | /* | |
476 | * It's not the end of the world if we don't get | |
477 | * the lock, but we also don't want to spin | |
478 | * nor do we want to disable interrupts, | |
479 | * so if we miss here, then better luck next time. | |
480 | */ | |
481 | if (!spin_trylock(&trace_cmdline_lock)) | |
482 | return; | |
483 | ||
484 | idx = map_pid_to_cmdline[tsk->pid]; | |
485 | if (idx >= SAVED_CMDLINES) { | |
486 | idx = (cmdline_idx + 1) % SAVED_CMDLINES; | |
487 | ||
488 | map = map_cmdline_to_pid[idx]; | |
489 | if (map <= PID_MAX_DEFAULT) | |
490 | map_pid_to_cmdline[map] = (unsigned)-1; | |
491 | ||
492 | map_pid_to_cmdline[tsk->pid] = idx; | |
493 | ||
494 | cmdline_idx = idx; | |
495 | } | |
496 | ||
497 | memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN); | |
498 | ||
499 | spin_unlock(&trace_cmdline_lock); | |
500 | } | |
501 | ||
502 | static notrace char *trace_find_cmdline(int pid) | |
503 | { | |
504 | char *cmdline = "<...>"; | |
505 | unsigned map; | |
506 | ||
507 | if (!pid) | |
508 | return "<idle>"; | |
509 | ||
510 | if (pid > PID_MAX_DEFAULT) | |
511 | goto out; | |
512 | ||
513 | map = map_pid_to_cmdline[pid]; | |
514 | if (map >= SAVED_CMDLINES) | |
515 | goto out; | |
516 | ||
517 | cmdline = saved_cmdlines[map]; | |
518 | ||
519 | out: | |
520 | return cmdline; | |
521 | } | |
522 | ||
523 | notrace void tracing_record_cmdline(struct task_struct *tsk) | |
524 | { | |
525 | if (atomic_read(&trace_record_cmdline_disabled)) | |
526 | return; | |
527 | ||
528 | trace_save_cmdline(tsk); | |
529 | } | |
530 | ||
93a588f4 SR |
531 | static inline notrace struct list_head * |
532 | trace_next_list(struct trace_array_cpu *data, struct list_head *next) | |
533 | { | |
534 | /* | |
535 | * Roundrobin - but skip the head (which is not a real page): | |
536 | */ | |
537 | next = next->next; | |
538 | if (unlikely(next == &data->trace_pages)) | |
539 | next = next->next; | |
540 | BUG_ON(next == &data->trace_pages); | |
541 | ||
542 | return next; | |
543 | } | |
544 | ||
545 | static inline notrace void * | |
546 | trace_next_page(struct trace_array_cpu *data, void *addr) | |
547 | { | |
548 | struct list_head *next; | |
549 | struct page *page; | |
550 | ||
551 | page = virt_to_page(addr); | |
552 | ||
553 | next = trace_next_list(data, &page->lru); | |
554 | page = list_entry(next, struct page, lru); | |
555 | ||
556 | return page_address(page); | |
557 | } | |
558 | ||
bc0c38d1 | 559 | static inline notrace struct trace_entry * |
c7aafc54 | 560 | tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data) |
bc0c38d1 SR |
561 | { |
562 | unsigned long idx, idx_next; | |
563 | struct trace_entry *entry; | |
564 | ||
4c11d7ae | 565 | data->trace_idx++; |
93a588f4 | 566 | idx = data->trace_head_idx; |
bc0c38d1 SR |
567 | idx_next = idx + 1; |
568 | ||
c7aafc54 IM |
569 | BUG_ON(idx * TRACE_ENTRY_SIZE >= PAGE_SIZE); |
570 | ||
93a588f4 | 571 | entry = data->trace_head + idx * TRACE_ENTRY_SIZE; |
4c11d7ae SR |
572 | |
573 | if (unlikely(idx_next >= ENTRIES_PER_PAGE)) { | |
93a588f4 | 574 | data->trace_head = trace_next_page(data, data->trace_head); |
bc0c38d1 SR |
575 | idx_next = 0; |
576 | } | |
577 | ||
93a588f4 SR |
578 | if (data->trace_head == data->trace_tail && |
579 | idx_next == data->trace_tail_idx) { | |
580 | /* overrun */ | |
581 | data->trace_tail_idx++; | |
582 | if (data->trace_tail_idx >= ENTRIES_PER_PAGE) { | |
583 | data->trace_tail = | |
584 | trace_next_page(data, data->trace_tail); | |
585 | data->trace_tail_idx = 0; | |
586 | } | |
587 | } | |
588 | ||
589 | data->trace_head_idx = idx_next; | |
bc0c38d1 SR |
590 | |
591 | return entry; | |
592 | } | |
593 | ||
594 | static inline notrace void | |
c7aafc54 | 595 | tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags) |
bc0c38d1 SR |
596 | { |
597 | struct task_struct *tsk = current; | |
598 | unsigned long pc; | |
599 | ||
600 | pc = preempt_count(); | |
601 | ||
c7aafc54 IM |
602 | entry->idx = atomic_inc_return(&tracer_counter); |
603 | entry->preempt_count = pc & 0xff; | |
604 | entry->pid = tsk->pid; | |
605 | entry->t = now(raw_smp_processor_id()); | |
bc0c38d1 SR |
606 | entry->flags = (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | |
607 | ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | | |
608 | ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | | |
609 | (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0); | |
610 | } | |
611 | ||
612 | notrace void | |
613 | ftrace(struct trace_array *tr, struct trace_array_cpu *data, | |
c7aafc54 | 614 | unsigned long ip, unsigned long parent_ip, unsigned long flags) |
bc0c38d1 SR |
615 | { |
616 | struct trace_entry *entry; | |
617 | ||
c7aafc54 | 618 | entry = tracing_get_trace_entry(tr, data); |
bc0c38d1 | 619 | tracing_generic_entry_update(entry, flags); |
c7aafc54 IM |
620 | entry->type = TRACE_FN; |
621 | entry->fn.ip = ip; | |
622 | entry->fn.parent_ip = parent_ip; | |
bc0c38d1 SR |
623 | } |
624 | ||
625 | notrace void | |
626 | tracing_sched_switch_trace(struct trace_array *tr, | |
627 | struct trace_array_cpu *data, | |
628 | struct task_struct *prev, struct task_struct *next, | |
629 | unsigned long flags) | |
630 | { | |
631 | struct trace_entry *entry; | |
632 | ||
c7aafc54 | 633 | entry = tracing_get_trace_entry(tr, data); |
bc0c38d1 SR |
634 | tracing_generic_entry_update(entry, flags); |
635 | entry->type = TRACE_CTX; | |
636 | entry->ctx.prev_pid = prev->pid; | |
637 | entry->ctx.prev_prio = prev->prio; | |
638 | entry->ctx.prev_state = prev->state; | |
639 | entry->ctx.next_pid = next->pid; | |
640 | entry->ctx.next_prio = next->prio; | |
641 | } | |
642 | ||
643 | enum trace_file_type { | |
644 | TRACE_FILE_LAT_FMT = 1, | |
645 | }; | |
646 | ||
647 | static struct trace_entry * | |
4c11d7ae SR |
648 | trace_entry_idx(struct trace_array *tr, struct trace_array_cpu *data, |
649 | struct trace_iterator *iter, int cpu) | |
bc0c38d1 | 650 | { |
4c11d7ae SR |
651 | struct page *page; |
652 | struct trace_entry *array; | |
bc0c38d1 | 653 | |
4c11d7ae SR |
654 | if (iter->next_idx[cpu] >= tr->entries || |
655 | iter->next_idx[cpu] >= data->trace_idx) | |
bc0c38d1 SR |
656 | return NULL; |
657 | ||
4c11d7ae | 658 | if (!iter->next_page[cpu]) { |
93a588f4 SR |
659 | /* Initialize the iterator for this cpu trace buffer */ |
660 | WARN_ON(!data->trace_tail); | |
661 | page = virt_to_page(data->trace_tail); | |
662 | iter->next_page[cpu] = &page->lru; | |
663 | iter->next_page_idx[cpu] = data->trace_tail_idx; | |
4c11d7ae | 664 | } |
bc0c38d1 | 665 | |
4c11d7ae | 666 | page = list_entry(iter->next_page[cpu], struct page, lru); |
c7aafc54 IM |
667 | BUG_ON(&data->trace_pages == &page->lru); |
668 | ||
4c11d7ae SR |
669 | array = page_address(page); |
670 | ||
93a588f4 SR |
671 | /* Still possible to catch up to the tail */ |
672 | if (iter->next_idx[cpu] && array == data->trace_tail && | |
673 | iter->next_page_idx[cpu] == data->trace_tail_idx) | |
674 | return NULL; | |
675 | ||
676 | WARN_ON(iter->next_page_idx[cpu] >= ENTRIES_PER_PAGE); | |
4c11d7ae | 677 | return &array[iter->next_page_idx[cpu]]; |
bc0c38d1 SR |
678 | } |
679 | ||
680 | static struct notrace trace_entry * | |
681 | find_next_entry(struct trace_iterator *iter, int *ent_cpu) | |
682 | { | |
683 | struct trace_array *tr = iter->tr; | |
684 | struct trace_entry *ent, *next = NULL; | |
685 | int next_cpu = -1; | |
686 | int cpu; | |
687 | ||
688 | for_each_possible_cpu(cpu) { | |
c7aafc54 | 689 | if (!head_page(tr->data[cpu])) |
bc0c38d1 | 690 | continue; |
4c11d7ae | 691 | ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu); |
bc0c38d1 SR |
692 | if (ent && |
693 | (!next || (long)(next->idx - ent->idx) > 0)) { | |
694 | next = ent; | |
695 | next_cpu = cpu; | |
696 | } | |
697 | } | |
698 | ||
699 | if (ent_cpu) | |
700 | *ent_cpu = next_cpu; | |
701 | ||
702 | return next; | |
703 | } | |
704 | ||
705 | static void *find_next_entry_inc(struct trace_iterator *iter) | |
706 | { | |
707 | struct trace_entry *next; | |
708 | int next_cpu = -1; | |
709 | ||
710 | next = find_next_entry(iter, &next_cpu); | |
711 | ||
712 | if (next) { | |
bc0c38d1 | 713 | iter->idx++; |
4c11d7ae SR |
714 | iter->next_idx[next_cpu]++; |
715 | iter->next_page_idx[next_cpu]++; | |
4e3c3333 | 716 | |
4c11d7ae SR |
717 | if (iter->next_page_idx[next_cpu] >= ENTRIES_PER_PAGE) { |
718 | struct trace_array_cpu *data = iter->tr->data[next_cpu]; | |
719 | ||
720 | iter->next_page_idx[next_cpu] = 0; | |
721 | iter->next_page[next_cpu] = | |
93a588f4 SR |
722 | trace_next_list(data, iter->next_page[next_cpu]); |
723 | ||
4c11d7ae | 724 | } |
bc0c38d1 | 725 | } |
4e3c3333 IM |
726 | iter->prev_ent = iter->ent; |
727 | iter->prev_cpu = iter->cpu; | |
728 | ||
bc0c38d1 SR |
729 | iter->ent = next; |
730 | iter->cpu = next_cpu; | |
731 | ||
732 | return next ? iter : NULL; | |
733 | } | |
734 | ||
4e3c3333 | 735 | static notrace void *s_next(struct seq_file *m, void *v, loff_t *pos) |
bc0c38d1 SR |
736 | { |
737 | struct trace_iterator *iter = m->private; | |
bc0c38d1 SR |
738 | void *last_ent = iter->ent; |
739 | int i = (int)*pos; | |
4e3c3333 | 740 | void *ent; |
bc0c38d1 SR |
741 | |
742 | (*pos)++; | |
743 | ||
744 | /* can't go backwards */ | |
745 | if (iter->idx > i) | |
746 | return NULL; | |
747 | ||
748 | if (iter->idx < 0) | |
749 | ent = find_next_entry_inc(iter); | |
750 | else | |
751 | ent = iter; | |
752 | ||
753 | while (ent && iter->idx < i) | |
754 | ent = find_next_entry_inc(iter); | |
755 | ||
756 | iter->pos = *pos; | |
757 | ||
758 | if (last_ent && !ent) | |
759 | seq_puts(m, "\n\nvim:ft=help\n"); | |
760 | ||
761 | return ent; | |
762 | } | |
763 | ||
764 | static void *s_start(struct seq_file *m, loff_t *pos) | |
765 | { | |
766 | struct trace_iterator *iter = m->private; | |
767 | void *p = NULL; | |
768 | loff_t l = 0; | |
769 | int i; | |
770 | ||
771 | mutex_lock(&trace_types_lock); | |
772 | ||
773 | if (!current_trace || current_trace != iter->trace) | |
774 | return NULL; | |
775 | ||
776 | atomic_inc(&trace_record_cmdline_disabled); | |
777 | ||
778 | /* let the tracer grab locks here if needed */ | |
779 | if (current_trace->start) | |
780 | current_trace->start(iter); | |
781 | ||
782 | if (*pos != iter->pos) { | |
783 | iter->ent = NULL; | |
784 | iter->cpu = 0; | |
785 | iter->idx = -1; | |
4e3c3333 IM |
786 | iter->prev_ent = NULL; |
787 | iter->prev_cpu = -1; | |
bc0c38d1 | 788 | |
4c11d7ae | 789 | for_each_possible_cpu(i) { |
bc0c38d1 | 790 | iter->next_idx[i] = 0; |
4c11d7ae SR |
791 | iter->next_page[i] = NULL; |
792 | } | |
bc0c38d1 SR |
793 | |
794 | for (p = iter; p && l < *pos; p = s_next(m, p, &l)) | |
795 | ; | |
796 | ||
797 | } else { | |
4c11d7ae | 798 | l = *pos - 1; |
bc0c38d1 SR |
799 | p = s_next(m, p, &l); |
800 | } | |
801 | ||
802 | return p; | |
803 | } | |
804 | ||
805 | static void s_stop(struct seq_file *m, void *p) | |
806 | { | |
807 | struct trace_iterator *iter = m->private; | |
808 | ||
809 | atomic_dec(&trace_record_cmdline_disabled); | |
810 | ||
811 | /* let the tracer release locks here if needed */ | |
812 | if (current_trace && current_trace == iter->trace && iter->trace->stop) | |
813 | iter->trace->stop(iter); | |
814 | ||
815 | mutex_unlock(&trace_types_lock); | |
816 | } | |
817 | ||
818 | static void | |
214023c3 | 819 | seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address) |
bc0c38d1 SR |
820 | { |
821 | #ifdef CONFIG_KALLSYMS | |
822 | char str[KSYM_SYMBOL_LEN]; | |
823 | ||
824 | kallsyms_lookup(address, NULL, NULL, NULL, str); | |
825 | ||
214023c3 | 826 | trace_seq_printf(s, fmt, str); |
bc0c38d1 SR |
827 | #endif |
828 | } | |
829 | ||
830 | static void | |
214023c3 SR |
831 | seq_print_sym_offset(struct trace_seq *s, const char *fmt, |
832 | unsigned long address) | |
bc0c38d1 SR |
833 | { |
834 | #ifdef CONFIG_KALLSYMS | |
835 | char str[KSYM_SYMBOL_LEN]; | |
836 | ||
837 | sprint_symbol(str, address); | |
214023c3 | 838 | trace_seq_printf(s, fmt, str); |
bc0c38d1 SR |
839 | #endif |
840 | } | |
841 | ||
842 | #ifndef CONFIG_64BIT | |
843 | # define IP_FMT "%08lx" | |
844 | #else | |
845 | # define IP_FMT "%016lx" | |
846 | #endif | |
847 | ||
4e3c3333 | 848 | static notrace void |
214023c3 | 849 | seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags) |
bc0c38d1 SR |
850 | { |
851 | if (!ip) { | |
214023c3 | 852 | trace_seq_printf(s, "0"); |
bc0c38d1 SR |
853 | return; |
854 | } | |
855 | ||
856 | if (sym_flags & TRACE_ITER_SYM_OFFSET) | |
214023c3 | 857 | seq_print_sym_offset(s, "%s", ip); |
bc0c38d1 | 858 | else |
214023c3 | 859 | seq_print_sym_short(s, "%s", ip); |
bc0c38d1 SR |
860 | |
861 | if (sym_flags & TRACE_ITER_SYM_ADDR) | |
214023c3 | 862 | trace_seq_printf(s, " <" IP_FMT ">", ip); |
bc0c38d1 SR |
863 | } |
864 | ||
4e3c3333 | 865 | static notrace void print_lat_help_header(struct seq_file *m) |
bc0c38d1 SR |
866 | { |
867 | seq_puts(m, "# _------=> CPU# \n"); | |
868 | seq_puts(m, "# / _-----=> irqs-off \n"); | |
869 | seq_puts(m, "# | / _----=> need-resched \n"); | |
870 | seq_puts(m, "# || / _---=> hardirq/softirq \n"); | |
871 | seq_puts(m, "# ||| / _--=> preempt-depth \n"); | |
872 | seq_puts(m, "# |||| / \n"); | |
873 | seq_puts(m, "# ||||| delay \n"); | |
874 | seq_puts(m, "# cmd pid ||||| time | caller \n"); | |
875 | seq_puts(m, "# \\ / ||||| \\ | / \n"); | |
876 | } | |
877 | ||
4e3c3333 | 878 | static notrace void print_func_help_header(struct seq_file *m) |
bc0c38d1 SR |
879 | { |
880 | seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); | |
881 | seq_puts(m, "# | | | | |\n"); | |
882 | } | |
883 | ||
884 | ||
4e3c3333 | 885 | static notrace void |
bc0c38d1 SR |
886 | print_trace_header(struct seq_file *m, struct trace_iterator *iter) |
887 | { | |
888 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); | |
889 | struct trace_array *tr = iter->tr; | |
890 | struct trace_array_cpu *data = tr->data[tr->cpu]; | |
891 | struct tracer *type = current_trace; | |
4c11d7ae SR |
892 | unsigned long total = 0; |
893 | unsigned long entries = 0; | |
bc0c38d1 SR |
894 | int cpu; |
895 | const char *name = "preemption"; | |
896 | ||
897 | if (type) | |
898 | name = type->name; | |
899 | ||
900 | for_each_possible_cpu(cpu) { | |
c7aafc54 | 901 | if (head_page(tr->data[cpu])) { |
4c11d7ae SR |
902 | total += tr->data[cpu]->trace_idx; |
903 | if (tr->data[cpu]->trace_idx > tr->entries) | |
bc0c38d1 | 904 | entries += tr->entries; |
4c11d7ae | 905 | else |
bc0c38d1 SR |
906 | entries += tr->data[cpu]->trace_idx; |
907 | } | |
908 | } | |
909 | ||
910 | seq_printf(m, "%s latency trace v1.1.5 on %s\n", | |
911 | name, UTS_RELEASE); | |
912 | seq_puts(m, "-----------------------------------" | |
913 | "---------------------------------\n"); | |
914 | seq_printf(m, " latency: %lu us, #%lu/%lu, CPU#%d |" | |
915 | " (M:%s VP:%d, KP:%d, SP:%d HP:%d", | |
57f50be1 | 916 | nsecs_to_usecs(data->saved_latency), |
bc0c38d1 | 917 | entries, |
4c11d7ae | 918 | total, |
bc0c38d1 SR |
919 | tr->cpu, |
920 | #if defined(CONFIG_PREEMPT_NONE) | |
921 | "server", | |
922 | #elif defined(CONFIG_PREEMPT_VOLUNTARY) | |
923 | "desktop", | |
924 | #elif defined(CONFIG_PREEMPT_DESKTOP) | |
925 | "preempt", | |
926 | #else | |
927 | "unknown", | |
928 | #endif | |
929 | /* These are reserved for later use */ | |
930 | 0, 0, 0, 0); | |
931 | #ifdef CONFIG_SMP | |
932 | seq_printf(m, " #P:%d)\n", num_online_cpus()); | |
933 | #else | |
934 | seq_puts(m, ")\n"); | |
935 | #endif | |
936 | seq_puts(m, " -----------------\n"); | |
937 | seq_printf(m, " | task: %.16s-%d " | |
938 | "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n", | |
939 | data->comm, data->pid, data->uid, data->nice, | |
940 | data->policy, data->rt_priority); | |
941 | seq_puts(m, " -----------------\n"); | |
942 | ||
943 | if (data->critical_start) { | |
944 | seq_puts(m, " => started at: "); | |
214023c3 SR |
945 | seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags); |
946 | trace_print_seq(m, &iter->seq); | |
bc0c38d1 | 947 | seq_puts(m, "\n => ended at: "); |
214023c3 SR |
948 | seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags); |
949 | trace_print_seq(m, &iter->seq); | |
bc0c38d1 SR |
950 | seq_puts(m, "\n"); |
951 | } | |
952 | ||
953 | seq_puts(m, "\n"); | |
954 | } | |
955 | ||
4e3c3333 | 956 | static notrace void |
214023c3 | 957 | lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) |
bc0c38d1 SR |
958 | { |
959 | int hardirq, softirq; | |
960 | char *comm; | |
961 | ||
962 | comm = trace_find_cmdline(entry->pid); | |
963 | ||
214023c3 SR |
964 | trace_seq_printf(s, "%8.8s-%-5d ", comm, entry->pid); |
965 | trace_seq_printf(s, "%d", cpu); | |
966 | trace_seq_printf(s, "%c%c", | |
967 | (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.', | |
968 | ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.')); | |
bc0c38d1 SR |
969 | |
970 | hardirq = entry->flags & TRACE_FLAG_HARDIRQ; | |
971 | softirq = entry->flags & TRACE_FLAG_SOFTIRQ; | |
972 | if (hardirq && softirq) | |
214023c3 | 973 | trace_seq_putc(s, 'H'); |
bc0c38d1 SR |
974 | else { |
975 | if (hardirq) | |
214023c3 | 976 | trace_seq_putc(s, 'h'); |
bc0c38d1 SR |
977 | else { |
978 | if (softirq) | |
214023c3 | 979 | trace_seq_putc(s, 's'); |
bc0c38d1 | 980 | else |
214023c3 | 981 | trace_seq_putc(s, '.'); |
bc0c38d1 SR |
982 | } |
983 | } | |
984 | ||
985 | if (entry->preempt_count) | |
214023c3 | 986 | trace_seq_printf(s, "%x", entry->preempt_count); |
bc0c38d1 | 987 | else |
214023c3 | 988 | trace_seq_puts(s, "."); |
bc0c38d1 SR |
989 | } |
990 | ||
991 | unsigned long preempt_mark_thresh = 100; | |
992 | ||
4e3c3333 | 993 | static notrace void |
214023c3 | 994 | lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs, |
bc0c38d1 SR |
995 | unsigned long rel_usecs) |
996 | { | |
214023c3 | 997 | trace_seq_printf(s, " %4lldus", abs_usecs); |
bc0c38d1 | 998 | if (rel_usecs > preempt_mark_thresh) |
214023c3 | 999 | trace_seq_puts(s, "!: "); |
bc0c38d1 | 1000 | else if (rel_usecs > 1) |
214023c3 | 1001 | trace_seq_puts(s, "+: "); |
bc0c38d1 | 1002 | else |
214023c3 | 1003 | trace_seq_puts(s, " : "); |
bc0c38d1 SR |
1004 | } |
1005 | ||
1006 | static const char state_to_char[] = TASK_STATE_TO_CHAR_STR; | |
1007 | ||
4e3c3333 | 1008 | static notrace void |
214023c3 | 1009 | print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) |
bc0c38d1 | 1010 | { |
214023c3 | 1011 | struct trace_seq *s = &iter->seq; |
bc0c38d1 SR |
1012 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); |
1013 | struct trace_entry *next_entry = find_next_entry(iter, NULL); | |
1014 | unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE); | |
1015 | struct trace_entry *entry = iter->ent; | |
1016 | unsigned long abs_usecs; | |
1017 | unsigned long rel_usecs; | |
1018 | char *comm; | |
1019 | int S; | |
1020 | ||
1021 | if (!next_entry) | |
1022 | next_entry = entry; | |
1023 | rel_usecs = ns2usecs(next_entry->t - entry->t); | |
1024 | abs_usecs = ns2usecs(entry->t - iter->tr->time_start); | |
1025 | ||
1026 | if (verbose) { | |
1027 | comm = trace_find_cmdline(entry->pid); | |
214023c3 SR |
1028 | trace_seq_printf(s, "%16s %5d %d %d %08x %08x [%08lx]" |
1029 | " %ld.%03ldms (+%ld.%03ldms): ", | |
1030 | comm, | |
1031 | entry->pid, cpu, entry->flags, | |
1032 | entry->preempt_count, trace_idx, | |
1033 | ns2usecs(entry->t), | |
1034 | abs_usecs/1000, | |
1035 | abs_usecs % 1000, rel_usecs/1000, | |
1036 | rel_usecs % 1000); | |
bc0c38d1 | 1037 | } else { |
214023c3 SR |
1038 | lat_print_generic(s, entry, cpu); |
1039 | lat_print_timestamp(s, abs_usecs, rel_usecs); | |
bc0c38d1 SR |
1040 | } |
1041 | switch (entry->type) { | |
1042 | case TRACE_FN: | |
214023c3 SR |
1043 | seq_print_ip_sym(s, entry->fn.ip, sym_flags); |
1044 | trace_seq_puts(s, " ("); | |
1045 | seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags); | |
1046 | trace_seq_puts(s, ")\n"); | |
bc0c38d1 SR |
1047 | break; |
1048 | case TRACE_CTX: | |
1049 | S = entry->ctx.prev_state < sizeof(state_to_char) ? | |
1050 | state_to_char[entry->ctx.prev_state] : 'X'; | |
1051 | comm = trace_find_cmdline(entry->ctx.next_pid); | |
214023c3 SR |
1052 | trace_seq_printf(s, " %d:%d:%c --> %d:%d %s\n", |
1053 | entry->ctx.prev_pid, | |
1054 | entry->ctx.prev_prio, | |
1055 | S, | |
1056 | entry->ctx.next_pid, | |
1057 | entry->ctx.next_prio, | |
1058 | comm); | |
bc0c38d1 | 1059 | break; |
89b2f978 | 1060 | default: |
214023c3 | 1061 | trace_seq_printf(s, "Unknown type %d\n", entry->type); |
bc0c38d1 SR |
1062 | } |
1063 | } | |
1064 | ||
4e3c3333 IM |
1065 | static notrace void sync_time_offset(struct trace_iterator *iter) |
1066 | { | |
1067 | struct trace_array_cpu *prev_array, *array; | |
1068 | struct trace_entry *prev_entry, *entry; | |
1069 | cycle_t prev_t, t; | |
1070 | ||
1071 | entry = iter->ent; | |
1072 | prev_entry = iter->prev_ent; | |
1073 | if (!prev_entry) | |
1074 | return; | |
1075 | ||
1076 | prev_array = iter->tr->data[iter->prev_cpu]; | |
1077 | array = iter->tr->data[iter->cpu]; | |
1078 | ||
1079 | prev_t = prev_entry->t + prev_array->time_offset; | |
1080 | t = entry->t + array->time_offset; | |
1081 | ||
1082 | /* | |
1083 | * If time goes backwards we increase the offset of | |
1084 | * the current array, to not have observable time warps. | |
1085 | * This will quickly synchronize the time offsets of | |
1086 | * multiple CPUs: | |
1087 | */ | |
1088 | if (t < prev_t) | |
1089 | array->time_offset += prev_t - t; | |
1090 | } | |
1091 | ||
1092 | static notrace void | |
214023c3 | 1093 | print_trace_fmt(struct trace_iterator *iter) |
bc0c38d1 | 1094 | { |
214023c3 | 1095 | struct trace_seq *s = &iter->seq; |
bc0c38d1 | 1096 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); |
4e3c3333 | 1097 | struct trace_entry *entry; |
bc0c38d1 SR |
1098 | unsigned long usec_rem; |
1099 | unsigned long long t; | |
1100 | unsigned long secs; | |
1101 | char *comm; | |
1102 | int S; | |
1103 | ||
4e3c3333 IM |
1104 | sync_time_offset(iter); |
1105 | entry = iter->ent; | |
1106 | ||
bc0c38d1 SR |
1107 | comm = trace_find_cmdline(iter->ent->pid); |
1108 | ||
4e3c3333 | 1109 | t = ns2usecs(entry->t + iter->tr->data[iter->cpu]->time_offset); |
bc0c38d1 SR |
1110 | usec_rem = do_div(t, 1000000ULL); |
1111 | secs = (unsigned long)t; | |
1112 | ||
214023c3 SR |
1113 | trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid); |
1114 | trace_seq_printf(s, "[%02d] ", iter->cpu); | |
1115 | trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem); | |
bc0c38d1 SR |
1116 | |
1117 | switch (entry->type) { | |
1118 | case TRACE_FN: | |
214023c3 | 1119 | seq_print_ip_sym(s, entry->fn.ip, sym_flags); |
bc0c38d1 SR |
1120 | if ((sym_flags & TRACE_ITER_PRINT_PARENT) && |
1121 | entry->fn.parent_ip) { | |
214023c3 SR |
1122 | trace_seq_printf(s, " <-"); |
1123 | seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags); | |
bc0c38d1 | 1124 | } |
214023c3 | 1125 | trace_seq_printf(s, "\n"); |
bc0c38d1 SR |
1126 | break; |
1127 | case TRACE_CTX: | |
1128 | S = entry->ctx.prev_state < sizeof(state_to_char) ? | |
1129 | state_to_char[entry->ctx.prev_state] : 'X'; | |
214023c3 SR |
1130 | trace_seq_printf(s, " %d:%d:%c ==> %d:%d\n", |
1131 | entry->ctx.prev_pid, | |
1132 | entry->ctx.prev_prio, | |
1133 | S, | |
1134 | entry->ctx.next_pid, | |
1135 | entry->ctx.next_prio); | |
bc0c38d1 SR |
1136 | break; |
1137 | } | |
bc0c38d1 SR |
1138 | } |
1139 | ||
1140 | static int trace_empty(struct trace_iterator *iter) | |
1141 | { | |
1142 | struct trace_array_cpu *data; | |
1143 | int cpu; | |
1144 | ||
1145 | for_each_possible_cpu(cpu) { | |
1146 | data = iter->tr->data[cpu]; | |
1147 | ||
c7aafc54 | 1148 | if (head_page(data) && data->trace_idx) |
bc0c38d1 SR |
1149 | return 0; |
1150 | } | |
1151 | return 1; | |
1152 | } | |
1153 | ||
1154 | static int s_show(struct seq_file *m, void *v) | |
1155 | { | |
1156 | struct trace_iterator *iter = v; | |
1157 | ||
1158 | if (iter->ent == NULL) { | |
1159 | if (iter->tr) { | |
1160 | seq_printf(m, "# tracer: %s\n", iter->trace->name); | |
1161 | seq_puts(m, "#\n"); | |
1162 | } | |
1163 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) { | |
1164 | /* print nothing if the buffers are empty */ | |
1165 | if (trace_empty(iter)) | |
1166 | return 0; | |
1167 | print_trace_header(m, iter); | |
1168 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
1169 | print_lat_help_header(m); | |
1170 | } else { | |
1171 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
1172 | print_func_help_header(m); | |
1173 | } | |
1174 | } else { | |
1175 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) | |
214023c3 | 1176 | print_lat_fmt(iter, iter->idx, iter->cpu); |
bc0c38d1 | 1177 | else |
214023c3 SR |
1178 | print_trace_fmt(iter); |
1179 | trace_print_seq(m, &iter->seq); | |
bc0c38d1 SR |
1180 | } |
1181 | ||
1182 | return 0; | |
1183 | } | |
1184 | ||
1185 | static struct seq_operations tracer_seq_ops = { | |
1186 | .start = s_start, | |
1187 | .next = s_next, | |
1188 | .stop = s_stop, | |
1189 | .show = s_show, | |
1190 | }; | |
1191 | ||
1192 | static struct trace_iterator notrace * | |
1193 | __tracing_open(struct inode *inode, struct file *file, int *ret) | |
1194 | { | |
1195 | struct trace_iterator *iter; | |
1196 | ||
60a11774 SR |
1197 | if (tracing_disabled) { |
1198 | *ret = -ENODEV; | |
1199 | return NULL; | |
1200 | } | |
1201 | ||
bc0c38d1 SR |
1202 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1203 | if (!iter) { | |
1204 | *ret = -ENOMEM; | |
1205 | goto out; | |
1206 | } | |
1207 | ||
1208 | mutex_lock(&trace_types_lock); | |
1209 | if (current_trace && current_trace->print_max) | |
1210 | iter->tr = &max_tr; | |
1211 | else | |
1212 | iter->tr = inode->i_private; | |
1213 | iter->trace = current_trace; | |
1214 | iter->pos = -1; | |
1215 | ||
1216 | /* TODO stop tracer */ | |
1217 | *ret = seq_open(file, &tracer_seq_ops); | |
1218 | if (!*ret) { | |
1219 | struct seq_file *m = file->private_data; | |
1220 | m->private = iter; | |
1221 | ||
1222 | /* stop the trace while dumping */ | |
1223 | if (iter->tr->ctrl) | |
1224 | tracer_enabled = 0; | |
1225 | ||
1226 | if (iter->trace && iter->trace->open) | |
1227 | iter->trace->open(iter); | |
1228 | } else { | |
1229 | kfree(iter); | |
1230 | iter = NULL; | |
1231 | } | |
1232 | mutex_unlock(&trace_types_lock); | |
1233 | ||
1234 | out: | |
1235 | return iter; | |
1236 | } | |
1237 | ||
1238 | int tracing_open_generic(struct inode *inode, struct file *filp) | |
1239 | { | |
60a11774 SR |
1240 | if (tracing_disabled) |
1241 | return -ENODEV; | |
1242 | ||
bc0c38d1 SR |
1243 | filp->private_data = inode->i_private; |
1244 | return 0; | |
1245 | } | |
1246 | ||
1247 | int tracing_release(struct inode *inode, struct file *file) | |
1248 | { | |
1249 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1250 | struct trace_iterator *iter = m->private; | |
1251 | ||
1252 | mutex_lock(&trace_types_lock); | |
1253 | if (iter->trace && iter->trace->close) | |
1254 | iter->trace->close(iter); | |
1255 | ||
1256 | /* reenable tracing if it was previously enabled */ | |
1257 | if (iter->tr->ctrl) | |
1258 | tracer_enabled = 1; | |
1259 | mutex_unlock(&trace_types_lock); | |
1260 | ||
1261 | seq_release(inode, file); | |
1262 | kfree(iter); | |
1263 | return 0; | |
1264 | } | |
1265 | ||
1266 | static int tracing_open(struct inode *inode, struct file *file) | |
1267 | { | |
1268 | int ret; | |
1269 | ||
1270 | __tracing_open(inode, file, &ret); | |
1271 | ||
1272 | return ret; | |
1273 | } | |
1274 | ||
1275 | static int tracing_lt_open(struct inode *inode, struct file *file) | |
1276 | { | |
1277 | struct trace_iterator *iter; | |
1278 | int ret; | |
1279 | ||
1280 | iter = __tracing_open(inode, file, &ret); | |
1281 | ||
1282 | if (!ret) | |
1283 | iter->iter_flags |= TRACE_FILE_LAT_FMT; | |
1284 | ||
1285 | return ret; | |
1286 | } | |
1287 | ||
1288 | ||
4e3c3333 | 1289 | static notrace void * |
bc0c38d1 SR |
1290 | t_next(struct seq_file *m, void *v, loff_t *pos) |
1291 | { | |
1292 | struct tracer *t = m->private; | |
1293 | ||
1294 | (*pos)++; | |
1295 | ||
1296 | if (t) | |
1297 | t = t->next; | |
1298 | ||
1299 | m->private = t; | |
1300 | ||
1301 | return t; | |
1302 | } | |
1303 | ||
1304 | static void *t_start(struct seq_file *m, loff_t *pos) | |
1305 | { | |
1306 | struct tracer *t = m->private; | |
1307 | loff_t l = 0; | |
1308 | ||
1309 | mutex_lock(&trace_types_lock); | |
1310 | for (; t && l < *pos; t = t_next(m, t, &l)) | |
1311 | ; | |
1312 | ||
1313 | return t; | |
1314 | } | |
1315 | ||
1316 | static void t_stop(struct seq_file *m, void *p) | |
1317 | { | |
1318 | mutex_unlock(&trace_types_lock); | |
1319 | } | |
1320 | ||
1321 | static int t_show(struct seq_file *m, void *v) | |
1322 | { | |
1323 | struct tracer *t = v; | |
1324 | ||
1325 | if (!t) | |
1326 | return 0; | |
1327 | ||
1328 | seq_printf(m, "%s", t->name); | |
1329 | if (t->next) | |
1330 | seq_putc(m, ' '); | |
1331 | else | |
1332 | seq_putc(m, '\n'); | |
1333 | ||
1334 | return 0; | |
1335 | } | |
1336 | ||
1337 | static struct seq_operations show_traces_seq_ops = { | |
1338 | .start = t_start, | |
1339 | .next = t_next, | |
1340 | .stop = t_stop, | |
1341 | .show = t_show, | |
1342 | }; | |
1343 | ||
1344 | static int show_traces_open(struct inode *inode, struct file *file) | |
1345 | { | |
1346 | int ret; | |
1347 | ||
60a11774 SR |
1348 | if (tracing_disabled) |
1349 | return -ENODEV; | |
1350 | ||
bc0c38d1 SR |
1351 | ret = seq_open(file, &show_traces_seq_ops); |
1352 | if (!ret) { | |
1353 | struct seq_file *m = file->private_data; | |
1354 | m->private = trace_types; | |
1355 | } | |
1356 | ||
1357 | return ret; | |
1358 | } | |
1359 | ||
1360 | static struct file_operations tracing_fops = { | |
1361 | .open = tracing_open, | |
1362 | .read = seq_read, | |
1363 | .llseek = seq_lseek, | |
1364 | .release = tracing_release, | |
1365 | }; | |
1366 | ||
1367 | static struct file_operations tracing_lt_fops = { | |
1368 | .open = tracing_lt_open, | |
1369 | .read = seq_read, | |
1370 | .llseek = seq_lseek, | |
1371 | .release = tracing_release, | |
1372 | }; | |
1373 | ||
1374 | static struct file_operations show_traces_fops = { | |
1375 | .open = show_traces_open, | |
1376 | .read = seq_read, | |
1377 | .release = seq_release, | |
1378 | }; | |
1379 | ||
1380 | static ssize_t | |
1381 | tracing_iter_ctrl_read(struct file *filp, char __user *ubuf, | |
1382 | size_t cnt, loff_t *ppos) | |
1383 | { | |
1384 | char *buf; | |
1385 | int r = 0; | |
1386 | int len = 0; | |
1387 | int i; | |
1388 | ||
1389 | /* calulate max size */ | |
1390 | for (i = 0; trace_options[i]; i++) { | |
1391 | len += strlen(trace_options[i]); | |
1392 | len += 3; /* "no" and space */ | |
1393 | } | |
1394 | ||
1395 | /* +2 for \n and \0 */ | |
1396 | buf = kmalloc(len + 2, GFP_KERNEL); | |
1397 | if (!buf) | |
1398 | return -ENOMEM; | |
1399 | ||
1400 | for (i = 0; trace_options[i]; i++) { | |
1401 | if (trace_flags & (1 << i)) | |
1402 | r += sprintf(buf + r, "%s ", trace_options[i]); | |
1403 | else | |
1404 | r += sprintf(buf + r, "no%s ", trace_options[i]); | |
1405 | } | |
1406 | ||
1407 | r += sprintf(buf + r, "\n"); | |
1408 | WARN_ON(r >= len + 2); | |
1409 | ||
1410 | r = simple_read_from_buffer(ubuf, cnt, ppos, | |
1411 | buf, r); | |
1412 | ||
1413 | kfree(buf); | |
1414 | ||
1415 | return r; | |
1416 | } | |
1417 | ||
1418 | static ssize_t | |
1419 | tracing_iter_ctrl_write(struct file *filp, const char __user *ubuf, | |
1420 | size_t cnt, loff_t *ppos) | |
1421 | { | |
1422 | char buf[64]; | |
1423 | char *cmp = buf; | |
1424 | int neg = 0; | |
1425 | int i; | |
1426 | ||
1427 | if (cnt > 63) | |
1428 | cnt = 63; | |
1429 | ||
1430 | if (copy_from_user(&buf, ubuf, cnt)) | |
1431 | return -EFAULT; | |
1432 | ||
1433 | buf[cnt] = 0; | |
1434 | ||
1435 | if (strncmp(buf, "no", 2) == 0) { | |
1436 | neg = 1; | |
1437 | cmp += 2; | |
1438 | } | |
1439 | ||
1440 | for (i = 0; trace_options[i]; i++) { | |
1441 | int len = strlen(trace_options[i]); | |
1442 | ||
1443 | if (strncmp(cmp, trace_options[i], len) == 0) { | |
1444 | if (neg) | |
1445 | trace_flags &= ~(1 << i); | |
1446 | else | |
1447 | trace_flags |= (1 << i); | |
1448 | break; | |
1449 | } | |
1450 | } | |
1451 | ||
1452 | filp->f_pos += cnt; | |
1453 | ||
1454 | return cnt; | |
1455 | } | |
1456 | ||
1457 | static struct file_operations tracing_iter_fops = { | |
1458 | .open = tracing_open_generic, | |
1459 | .read = tracing_iter_ctrl_read, | |
1460 | .write = tracing_iter_ctrl_write, | |
1461 | }; | |
1462 | ||
7bd2f24c IM |
1463 | static const char readme_msg[] = |
1464 | "tracing mini-HOWTO:\n\n" | |
1465 | "# mkdir /debug\n" | |
1466 | "# mount -t debugfs nodev /debug\n\n" | |
1467 | "# cat /debug/tracing/available_tracers\n" | |
1468 | "wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none\n\n" | |
1469 | "# cat /debug/tracing/current_tracer\n" | |
1470 | "none\n" | |
1471 | "# echo sched_switch > /debug/tracing/current_tracer\n" | |
1472 | "# cat /debug/tracing/current_tracer\n" | |
1473 | "sched_switch\n" | |
1474 | "# cat /debug/tracing/iter_ctrl\n" | |
1475 | "noprint-parent nosym-offset nosym-addr noverbose\n" | |
1476 | "# echo print-parent > /debug/tracing/iter_ctrl\n" | |
1477 | "# echo 1 > /debug/tracing/tracing_enabled\n" | |
1478 | "# cat /debug/tracing/trace > /tmp/trace.txt\n" | |
1479 | "echo 0 > /debug/tracing/tracing_enabled\n" | |
1480 | ; | |
1481 | ||
1482 | static ssize_t | |
1483 | tracing_readme_read(struct file *filp, char __user *ubuf, | |
1484 | size_t cnt, loff_t *ppos) | |
1485 | { | |
1486 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
1487 | readme_msg, strlen(readme_msg)); | |
1488 | } | |
1489 | ||
1490 | static struct file_operations tracing_readme_fops = { | |
1491 | .open = tracing_open_generic, | |
1492 | .read = tracing_readme_read, | |
1493 | }; | |
1494 | ||
1495 | ||
bc0c38d1 SR |
1496 | static ssize_t |
1497 | tracing_ctrl_read(struct file *filp, char __user *ubuf, | |
1498 | size_t cnt, loff_t *ppos) | |
1499 | { | |
1500 | struct trace_array *tr = filp->private_data; | |
1501 | char buf[64]; | |
1502 | int r; | |
1503 | ||
1504 | r = sprintf(buf, "%ld\n", tr->ctrl); | |
4e3c3333 | 1505 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
1506 | } |
1507 | ||
1508 | static ssize_t | |
1509 | tracing_ctrl_write(struct file *filp, const char __user *ubuf, | |
1510 | size_t cnt, loff_t *ppos) | |
1511 | { | |
1512 | struct trace_array *tr = filp->private_data; | |
1513 | long val; | |
1514 | char buf[64]; | |
1515 | ||
1516 | if (cnt > 63) | |
1517 | cnt = 63; | |
1518 | ||
1519 | if (copy_from_user(&buf, ubuf, cnt)) | |
1520 | return -EFAULT; | |
1521 | ||
1522 | buf[cnt] = 0; | |
1523 | ||
1524 | val = simple_strtoul(buf, NULL, 10); | |
1525 | ||
1526 | val = !!val; | |
1527 | ||
1528 | mutex_lock(&trace_types_lock); | |
1529 | if (tr->ctrl ^ val) { | |
1530 | if (val) | |
1531 | tracer_enabled = 1; | |
1532 | else | |
1533 | tracer_enabled = 0; | |
1534 | ||
1535 | tr->ctrl = val; | |
1536 | ||
1537 | if (current_trace && current_trace->ctrl_update) | |
1538 | current_trace->ctrl_update(tr); | |
1539 | } | |
1540 | mutex_unlock(&trace_types_lock); | |
1541 | ||
1542 | filp->f_pos += cnt; | |
1543 | ||
1544 | return cnt; | |
1545 | } | |
1546 | ||
1547 | static ssize_t | |
1548 | tracing_set_trace_read(struct file *filp, char __user *ubuf, | |
1549 | size_t cnt, loff_t *ppos) | |
1550 | { | |
1551 | char buf[max_tracer_type_len+2]; | |
1552 | int r; | |
1553 | ||
1554 | mutex_lock(&trace_types_lock); | |
1555 | if (current_trace) | |
1556 | r = sprintf(buf, "%s\n", current_trace->name); | |
1557 | else | |
1558 | r = sprintf(buf, "\n"); | |
1559 | mutex_unlock(&trace_types_lock); | |
1560 | ||
1561 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
1562 | buf, r); | |
1563 | } | |
1564 | ||
1565 | static ssize_t | |
1566 | tracing_set_trace_write(struct file *filp, const char __user *ubuf, | |
1567 | size_t cnt, loff_t *ppos) | |
1568 | { | |
1569 | struct trace_array *tr = &global_trace; | |
1570 | struct tracer *t; | |
1571 | char buf[max_tracer_type_len+1]; | |
1572 | int i; | |
1573 | ||
1574 | if (cnt > max_tracer_type_len) | |
1575 | cnt = max_tracer_type_len; | |
1576 | ||
1577 | if (copy_from_user(&buf, ubuf, cnt)) | |
1578 | return -EFAULT; | |
1579 | ||
1580 | buf[cnt] = 0; | |
1581 | ||
1582 | /* strip ending whitespace. */ | |
1583 | for (i = cnt - 1; i > 0 && isspace(buf[i]); i--) | |
1584 | buf[i] = 0; | |
1585 | ||
1586 | mutex_lock(&trace_types_lock); | |
1587 | for (t = trace_types; t; t = t->next) { | |
1588 | if (strcmp(t->name, buf) == 0) | |
1589 | break; | |
1590 | } | |
1591 | if (!t || t == current_trace) | |
1592 | goto out; | |
1593 | ||
1594 | if (current_trace && current_trace->reset) | |
1595 | current_trace->reset(tr); | |
1596 | ||
1597 | current_trace = t; | |
1598 | if (t->init) | |
1599 | t->init(tr); | |
1600 | ||
1601 | out: | |
1602 | mutex_unlock(&trace_types_lock); | |
1603 | ||
1604 | filp->f_pos += cnt; | |
1605 | ||
1606 | return cnt; | |
1607 | } | |
1608 | ||
1609 | static ssize_t | |
1610 | tracing_max_lat_read(struct file *filp, char __user *ubuf, | |
1611 | size_t cnt, loff_t *ppos) | |
1612 | { | |
1613 | unsigned long *ptr = filp->private_data; | |
1614 | char buf[64]; | |
1615 | int r; | |
1616 | ||
1617 | r = snprintf(buf, 64, "%ld\n", | |
1618 | *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr)); | |
1619 | if (r > 64) | |
1620 | r = 64; | |
1621 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
1622 | buf, r); | |
1623 | } | |
1624 | ||
1625 | static ssize_t | |
1626 | tracing_max_lat_write(struct file *filp, const char __user *ubuf, | |
1627 | size_t cnt, loff_t *ppos) | |
1628 | { | |
1629 | long *ptr = filp->private_data; | |
1630 | long val; | |
1631 | char buf[64]; | |
1632 | ||
1633 | if (cnt > 63) | |
1634 | cnt = 63; | |
1635 | ||
1636 | if (copy_from_user(&buf, ubuf, cnt)) | |
1637 | return -EFAULT; | |
1638 | ||
1639 | buf[cnt] = 0; | |
1640 | ||
1641 | val = simple_strtoul(buf, NULL, 10); | |
1642 | ||
1643 | *ptr = val * 1000; | |
1644 | ||
1645 | return cnt; | |
1646 | } | |
1647 | ||
1648 | static struct file_operations tracing_max_lat_fops = { | |
1649 | .open = tracing_open_generic, | |
1650 | .read = tracing_max_lat_read, | |
1651 | .write = tracing_max_lat_write, | |
1652 | }; | |
1653 | ||
1654 | static struct file_operations tracing_ctrl_fops = { | |
1655 | .open = tracing_open_generic, | |
1656 | .read = tracing_ctrl_read, | |
1657 | .write = tracing_ctrl_write, | |
1658 | }; | |
1659 | ||
1660 | static struct file_operations set_tracer_fops = { | |
1661 | .open = tracing_open_generic, | |
1662 | .read = tracing_set_trace_read, | |
1663 | .write = tracing_set_trace_write, | |
1664 | }; | |
1665 | ||
1666 | #ifdef CONFIG_DYNAMIC_FTRACE | |
1667 | ||
1668 | static ssize_t | |
1669 | tracing_read_long(struct file *filp, char __user *ubuf, | |
1670 | size_t cnt, loff_t *ppos) | |
1671 | { | |
1672 | unsigned long *p = filp->private_data; | |
1673 | char buf[64]; | |
1674 | int r; | |
1675 | ||
1676 | r = sprintf(buf, "%ld\n", *p); | |
1677 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
1678 | buf, r); | |
1679 | } | |
1680 | ||
1681 | static struct file_operations tracing_read_long_fops = { | |
1682 | .open = tracing_open_generic, | |
1683 | .read = tracing_read_long, | |
1684 | }; | |
1685 | #endif | |
1686 | ||
1687 | static struct dentry *d_tracer; | |
1688 | ||
1689 | struct dentry *tracing_init_dentry(void) | |
1690 | { | |
1691 | static int once; | |
1692 | ||
1693 | if (d_tracer) | |
1694 | return d_tracer; | |
1695 | ||
1696 | d_tracer = debugfs_create_dir("tracing", NULL); | |
1697 | ||
1698 | if (!d_tracer && !once) { | |
1699 | once = 1; | |
1700 | pr_warning("Could not create debugfs directory 'tracing'\n"); | |
1701 | return NULL; | |
1702 | } | |
1703 | ||
1704 | return d_tracer; | |
1705 | } | |
1706 | ||
60a11774 SR |
1707 | #ifdef CONFIG_FTRACE_SELFTEST |
1708 | /* Let selftest have access to static functions in this file */ | |
1709 | #include "trace_selftest.c" | |
1710 | #endif | |
1711 | ||
bc0c38d1 SR |
1712 | static __init void tracer_init_debugfs(void) |
1713 | { | |
1714 | struct dentry *d_tracer; | |
1715 | struct dentry *entry; | |
1716 | ||
1717 | d_tracer = tracing_init_dentry(); | |
1718 | ||
1719 | entry = debugfs_create_file("tracing_enabled", 0644, d_tracer, | |
1720 | &global_trace, &tracing_ctrl_fops); | |
1721 | if (!entry) | |
1722 | pr_warning("Could not create debugfs 'tracing_enabled' entry\n"); | |
1723 | ||
1724 | entry = debugfs_create_file("iter_ctrl", 0644, d_tracer, | |
1725 | NULL, &tracing_iter_fops); | |
1726 | if (!entry) | |
1727 | pr_warning("Could not create debugfs 'iter_ctrl' entry\n"); | |
1728 | ||
1729 | entry = debugfs_create_file("latency_trace", 0444, d_tracer, | |
1730 | &global_trace, &tracing_lt_fops); | |
1731 | if (!entry) | |
1732 | pr_warning("Could not create debugfs 'latency_trace' entry\n"); | |
1733 | ||
1734 | entry = debugfs_create_file("trace", 0444, d_tracer, | |
1735 | &global_trace, &tracing_fops); | |
1736 | if (!entry) | |
1737 | pr_warning("Could not create debugfs 'trace' entry\n"); | |
1738 | ||
1739 | entry = debugfs_create_file("available_tracers", 0444, d_tracer, | |
1740 | &global_trace, &show_traces_fops); | |
1741 | if (!entry) | |
1742 | pr_warning("Could not create debugfs 'trace' entry\n"); | |
1743 | ||
1744 | entry = debugfs_create_file("current_tracer", 0444, d_tracer, | |
1745 | &global_trace, &set_tracer_fops); | |
1746 | if (!entry) | |
1747 | pr_warning("Could not create debugfs 'trace' entry\n"); | |
1748 | ||
1749 | entry = debugfs_create_file("tracing_max_latency", 0644, d_tracer, | |
1750 | &tracing_max_latency, | |
1751 | &tracing_max_lat_fops); | |
1752 | if (!entry) | |
1753 | pr_warning("Could not create debugfs " | |
1754 | "'tracing_max_latency' entry\n"); | |
1755 | ||
1756 | entry = debugfs_create_file("tracing_thresh", 0644, d_tracer, | |
1757 | &tracing_thresh, &tracing_max_lat_fops); | |
1758 | if (!entry) | |
1759 | pr_warning("Could not create debugfs " | |
1760 | "'tracing_threash' entry\n"); | |
7bd2f24c IM |
1761 | entry = debugfs_create_file("README", 0644, d_tracer, |
1762 | NULL, &tracing_readme_fops); | |
1763 | if (!entry) | |
1764 | pr_warning("Could not create debugfs 'README' entry\n"); | |
1765 | ||
bc0c38d1 SR |
1766 | |
1767 | #ifdef CONFIG_DYNAMIC_FTRACE | |
1768 | entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer, | |
1769 | &ftrace_update_tot_cnt, | |
1770 | &tracing_read_long_fops); | |
1771 | if (!entry) | |
1772 | pr_warning("Could not create debugfs " | |
1773 | "'dyn_ftrace_total_info' entry\n"); | |
1774 | #endif | |
1775 | } | |
1776 | ||
1777 | /* dummy trace to disable tracing */ | |
1778 | static struct tracer no_tracer __read_mostly = | |
1779 | { | |
1780 | .name = "none", | |
1781 | }; | |
1782 | ||
4c11d7ae | 1783 | static int trace_alloc_page(void) |
bc0c38d1 | 1784 | { |
4c11d7ae | 1785 | struct trace_array_cpu *data; |
4c11d7ae SR |
1786 | struct page *page, *tmp; |
1787 | LIST_HEAD(pages); | |
c7aafc54 | 1788 | void *array; |
4c11d7ae SR |
1789 | int i; |
1790 | ||
1791 | /* first allocate a page for each CPU */ | |
1792 | for_each_possible_cpu(i) { | |
1793 | array = (void *)__get_free_page(GFP_KERNEL); | |
1794 | if (array == NULL) { | |
1795 | printk(KERN_ERR "tracer: failed to allocate page" | |
1796 | "for trace buffer!\n"); | |
1797 | goto free_pages; | |
1798 | } | |
1799 | ||
1800 | page = virt_to_page(array); | |
1801 | list_add(&page->lru, &pages); | |
1802 | ||
1803 | /* Only allocate if we are actually using the max trace */ | |
1804 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1805 | array = (void *)__get_free_page(GFP_KERNEL); | |
1806 | if (array == NULL) { | |
1807 | printk(KERN_ERR "tracer: failed to allocate page" | |
1808 | "for trace buffer!\n"); | |
1809 | goto free_pages; | |
1810 | } | |
1811 | page = virt_to_page(array); | |
1812 | list_add(&page->lru, &pages); | |
1813 | #endif | |
1814 | } | |
1815 | ||
1816 | /* Now that we successfully allocate a page per CPU, add them */ | |
1817 | for_each_possible_cpu(i) { | |
1818 | data = global_trace.data[i]; | |
1819 | page = list_entry(pages.next, struct page, lru); | |
c7aafc54 | 1820 | list_del_init(&page->lru); |
4c11d7ae SR |
1821 | list_add_tail(&page->lru, &data->trace_pages); |
1822 | ClearPageLRU(page); | |
1823 | ||
1824 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1825 | data = max_tr.data[i]; | |
1826 | page = list_entry(pages.next, struct page, lru); | |
c7aafc54 | 1827 | list_del_init(&page->lru); |
4c11d7ae SR |
1828 | list_add_tail(&page->lru, &data->trace_pages); |
1829 | SetPageLRU(page); | |
1830 | #endif | |
1831 | } | |
1832 | global_trace.entries += ENTRIES_PER_PAGE; | |
1833 | ||
1834 | return 0; | |
1835 | ||
1836 | free_pages: | |
1837 | list_for_each_entry_safe(page, tmp, &pages, lru) { | |
c7aafc54 | 1838 | list_del_init(&page->lru); |
4c11d7ae SR |
1839 | __free_page(page); |
1840 | } | |
1841 | return -ENOMEM; | |
bc0c38d1 SR |
1842 | } |
1843 | ||
1844 | __init static int tracer_alloc_buffers(void) | |
1845 | { | |
4c11d7ae SR |
1846 | struct trace_array_cpu *data; |
1847 | void *array; | |
1848 | struct page *page; | |
1849 | int pages = 0; | |
60a11774 | 1850 | int ret = -ENOMEM; |
bc0c38d1 SR |
1851 | int i; |
1852 | ||
4c11d7ae | 1853 | /* Allocate the first page for all buffers */ |
bc0c38d1 | 1854 | for_each_possible_cpu(i) { |
4c11d7ae | 1855 | data = global_trace.data[i] = &per_cpu(global_trace_cpu, i); |
bc0c38d1 SR |
1856 | max_tr.data[i] = &per_cpu(max_data, i); |
1857 | ||
4c11d7ae | 1858 | array = (void *)__get_free_page(GFP_KERNEL); |
bc0c38d1 | 1859 | if (array == NULL) { |
4c11d7ae SR |
1860 | printk(KERN_ERR "tracer: failed to allocate page" |
1861 | "for trace buffer!\n"); | |
bc0c38d1 SR |
1862 | goto free_buffers; |
1863 | } | |
4c11d7ae SR |
1864 | |
1865 | /* set the array to the list */ | |
1866 | INIT_LIST_HEAD(&data->trace_pages); | |
1867 | page = virt_to_page(array); | |
1868 | list_add(&page->lru, &data->trace_pages); | |
1869 | /* use the LRU flag to differentiate the two buffers */ | |
1870 | ClearPageLRU(page); | |
bc0c38d1 SR |
1871 | |
1872 | /* Only allocate if we are actually using the max trace */ | |
1873 | #ifdef CONFIG_TRACER_MAX_TRACE | |
4c11d7ae | 1874 | array = (void *)__get_free_page(GFP_KERNEL); |
bc0c38d1 | 1875 | if (array == NULL) { |
4c11d7ae SR |
1876 | printk(KERN_ERR "tracer: failed to allocate page" |
1877 | "for trace buffer!\n"); | |
bc0c38d1 SR |
1878 | goto free_buffers; |
1879 | } | |
4c11d7ae SR |
1880 | |
1881 | INIT_LIST_HEAD(&max_tr.data[i]->trace_pages); | |
1882 | page = virt_to_page(array); | |
1883 | list_add(&page->lru, &max_tr.data[i]->trace_pages); | |
1884 | SetPageLRU(page); | |
bc0c38d1 SR |
1885 | #endif |
1886 | } | |
1887 | ||
1888 | /* | |
1889 | * Since we allocate by orders of pages, we may be able to | |
1890 | * round up a bit. | |
1891 | */ | |
4c11d7ae | 1892 | global_trace.entries = ENTRIES_PER_PAGE; |
4c11d7ae SR |
1893 | pages++; |
1894 | ||
1895 | while (global_trace.entries < trace_nr_entries) { | |
1896 | if (trace_alloc_page()) | |
1897 | break; | |
1898 | pages++; | |
1899 | } | |
89b2f978 | 1900 | max_tr.entries = global_trace.entries; |
bc0c38d1 | 1901 | |
4c11d7ae SR |
1902 | pr_info("tracer: %d pages allocated for %ld", |
1903 | pages, trace_nr_entries); | |
bc0c38d1 SR |
1904 | pr_info(" entries of %ld bytes\n", (long)TRACE_ENTRY_SIZE); |
1905 | pr_info(" actual entries %ld\n", global_trace.entries); | |
1906 | ||
1907 | tracer_init_debugfs(); | |
1908 | ||
1909 | trace_init_cmdlines(); | |
1910 | ||
1911 | register_tracer(&no_tracer); | |
1912 | current_trace = &no_tracer; | |
1913 | ||
60a11774 SR |
1914 | /* All seems OK, enable tracing */ |
1915 | tracing_disabled = 0; | |
1916 | ||
bc0c38d1 SR |
1917 | return 0; |
1918 | ||
1919 | free_buffers: | |
1920 | for (i-- ; i >= 0; i--) { | |
4c11d7ae | 1921 | struct page *page, *tmp; |
bc0c38d1 SR |
1922 | struct trace_array_cpu *data = global_trace.data[i]; |
1923 | ||
c7aafc54 | 1924 | if (data) { |
4c11d7ae SR |
1925 | list_for_each_entry_safe(page, tmp, |
1926 | &data->trace_pages, lru) { | |
c7aafc54 | 1927 | list_del_init(&page->lru); |
4c11d7ae SR |
1928 | __free_page(page); |
1929 | } | |
bc0c38d1 SR |
1930 | } |
1931 | ||
1932 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1933 | data = max_tr.data[i]; | |
c7aafc54 | 1934 | if (data) { |
4c11d7ae SR |
1935 | list_for_each_entry_safe(page, tmp, |
1936 | &data->trace_pages, lru) { | |
c7aafc54 | 1937 | list_del_init(&page->lru); |
4c11d7ae SR |
1938 | __free_page(page); |
1939 | } | |
bc0c38d1 SR |
1940 | } |
1941 | #endif | |
1942 | } | |
60a11774 | 1943 | return ret; |
bc0c38d1 SR |
1944 | } |
1945 | ||
60a11774 | 1946 | fs_initcall(tracer_alloc_buffers); |