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