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