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ath9k_hw: make two initvals consto for the AR9001 family
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / trace / trace_functions_graph.c
blobe998a824e9db5480f7e9b43bb74f2856a1f1d921
1 /*
2 *
3 * Function graph tracer.
4 * Copyright (c) 2008-2009 Frederic Weisbecker <fweisbec@gmail.com>
5 * Mostly borrowed from function tracer which
6 * is Copyright (c) Steven Rostedt <srostedt@redhat.com>
7 *
8 */
9 #include <linux/debugfs.h>
10 #include <linux/uaccess.h>
11 #include <linux/ftrace.h>
12 #include <linux/fs.h>
13
14 #include "trace.h"
15 #include "trace_output.h"
16
17 struct fgraph_cpu_data {
18 pid_t last_pid;
19 int depth;
20 int ignore;
21 unsigned long enter_funcs[FTRACE_RETFUNC_DEPTH];
22 };
23
24 struct fgraph_data {
25 struct fgraph_cpu_data *cpu_data;
26
27 /* Place to preserve last processed entry. */
28 struct ftrace_graph_ent_entry ent;
29 struct ftrace_graph_ret_entry ret;
30 int failed;
31 int cpu;
32 };
33
34 #define TRACE_GRAPH_INDENT 2
35
36 /* Flag options */
37 #define TRACE_GRAPH_PRINT_OVERRUN 0x1
38 #define TRACE_GRAPH_PRINT_CPU 0x2
39 #define TRACE_GRAPH_PRINT_OVERHEAD 0x4
40 #define TRACE_GRAPH_PRINT_PROC 0x8
41 #define TRACE_GRAPH_PRINT_DURATION 0x10
42 #define TRACE_GRAPH_PRINT_ABS_TIME 0X20
43
44 static struct tracer_opt trace_opts[] = {
45 /* Display overruns? (for self-debug purpose) */
46 { TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) },
47 /* Display CPU ? */
48 { TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },
49 /* Display Overhead ? */
50 { TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },
51 /* Display proc name/pid */
52 { TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) },
53 /* Display duration of execution */
54 { TRACER_OPT(funcgraph-duration, TRACE_GRAPH_PRINT_DURATION) },
55 /* Display absolute time of an entry */
56 { TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) },
57 { } /* Empty entry */
58 };
59
60 static struct tracer_flags tracer_flags = {
61 /* Don't display overruns and proc by default */
62 .val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD |
63 TRACE_GRAPH_PRINT_DURATION,
64 .opts = trace_opts
65 };
66
67 static struct trace_array *graph_array;
68
69
70 /* Add a function return address to the trace stack on thread info.*/
71 int
72 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
73 unsigned long frame_pointer)
74 {
75 unsigned long long calltime;
76 int index;
77
78 if (!current->ret_stack)
79 return -EBUSY;
80
81 /*
82 * We must make sure the ret_stack is tested before we read
83 * anything else.
84 */
85 smp_rmb();
86
87 /* The return trace stack is full */
88 if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
89 atomic_inc(&current->trace_overrun);
90 return -EBUSY;
91 }
92
93 calltime = trace_clock_local();
94
95 index = ++current->curr_ret_stack;
96 barrier();
97 current->ret_stack[index].ret = ret;
98 current->ret_stack[index].func = func;
99 current->ret_stack[index].calltime = calltime;
100 current->ret_stack[index].subtime = 0;
101 current->ret_stack[index].fp = frame_pointer;
102 *depth = index;
103
104 return 0;
105 }
106
107 /* Retrieve a function return address to the trace stack on thread info.*/
108 static void
109 ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
110 unsigned long frame_pointer)
111 {
112 int index;
113
114 index = current->curr_ret_stack;
115
116 if (unlikely(index < 0)) {
117 ftrace_graph_stop();
118 WARN_ON(1);
119 /* Might as well panic, otherwise we have no where to go */
120 *ret = (unsigned long)panic;
121 return;
122 }
123
124 #ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST
125 /*
126 * The arch may choose to record the frame pointer used
127 * and check it here to make sure that it is what we expect it
128 * to be. If gcc does not set the place holder of the return
129 * address in the frame pointer, and does a copy instead, then
130 * the function graph trace will fail. This test detects this
131 * case.
132 *
133 * Currently, x86_32 with optimize for size (-Os) makes the latest
134 * gcc do the above.
135 */
136 if (unlikely(current->ret_stack[index].fp != frame_pointer)) {
137 ftrace_graph_stop();
138 WARN(1, "Bad frame pointer: expected %lx, received %lx\n"
139 " from func %ps return to %lx\n",
140 current->ret_stack[index].fp,
141 frame_pointer,
142 (void *)current->ret_stack[index].func,
143 current->ret_stack[index].ret);
144 *ret = (unsigned long)panic;
145 return;
146 }
147 #endif
148
149 *ret = current->ret_stack[index].ret;
150 trace->func = current->ret_stack[index].func;
151 trace->calltime = current->ret_stack[index].calltime;
152 trace->overrun = atomic_read(&current->trace_overrun);
153 trace->depth = index;
154 }
155
156 /*
157 * Send the trace to the ring-buffer.
158 * @return the original return address.
159 */
160 unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
161 {
162 struct ftrace_graph_ret trace;
163 unsigned long ret;
164
165 ftrace_pop_return_trace(&trace, &ret, frame_pointer);
166 trace.rettime = trace_clock_local();
167 ftrace_graph_return(&trace);
168 barrier();
169 current->curr_ret_stack--;
170
171 if (unlikely(!ret)) {
172 ftrace_graph_stop();
173 WARN_ON(1);
174 /* Might as well panic. What else to do? */
175 ret = (unsigned long)panic;
176 }
177
178 return ret;
179 }
180
181 static int __trace_graph_entry(struct trace_array *tr,
182 struct ftrace_graph_ent *trace,
183 unsigned long flags,
184 int pc)
185 {
186 struct ftrace_event_call *call = &event_funcgraph_entry;
187 struct ring_buffer_event *event;
188 struct ring_buffer *buffer = tr->buffer;
189 struct ftrace_graph_ent_entry *entry;
190
191 if (unlikely(__this_cpu_read(per_cpu_var(ftrace_cpu_disabled))))
192 return 0;
193
194 event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
195 sizeof(*entry), flags, pc);
196 if (!event)
197 return 0;
198 entry = ring_buffer_event_data(event);
199 entry->graph_ent = *trace;
200 if (!filter_current_check_discard(buffer, call, entry, event))
201 ring_buffer_unlock_commit(buffer, event);
202
203 return 1;
204 }
205
206 int trace_graph_entry(struct ftrace_graph_ent *trace)
207 {
208 struct trace_array *tr = graph_array;
209 struct trace_array_cpu *data;
210 unsigned long flags;
211 long disabled;
212 int ret;
213 int cpu;
214 int pc;
215
216 if (!ftrace_trace_task(current))
217 return 0;
218
219 /* trace it when it is-nested-in or is a function enabled. */
220 if (!(trace->depth || ftrace_graph_addr(trace->func)))
221 return 0;
222
223 local_irq_save(flags);
224 cpu = raw_smp_processor_id();
225 data = tr->data[cpu];
226 disabled = atomic_inc_return(&data->disabled);
227 if (likely(disabled == 1)) {
228 pc = preempt_count();
229 ret = __trace_graph_entry(tr, trace, flags, pc);
230 } else {
231 ret = 0;
232 }
233
234 atomic_dec(&data->disabled);
235 local_irq_restore(flags);
236
237 return ret;
238 }
239
240 static void __trace_graph_return(struct trace_array *tr,
241 struct ftrace_graph_ret *trace,
242 unsigned long flags,
243 int pc)
244 {
245 struct ftrace_event_call *call = &event_funcgraph_exit;
246 struct ring_buffer_event *event;
247 struct ring_buffer *buffer = tr->buffer;
248 struct ftrace_graph_ret_entry *entry;
249
250 if (unlikely(__this_cpu_read(per_cpu_var(ftrace_cpu_disabled))))
251 return;
252
253 event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
254 sizeof(*entry), flags, pc);
255 if (!event)
256 return;
257 entry = ring_buffer_event_data(event);
258 entry->ret = *trace;
259 if (!filter_current_check_discard(buffer, call, entry, event))
260 ring_buffer_unlock_commit(buffer, event);
261 }
262
263 void trace_graph_return(struct ftrace_graph_ret *trace)
264 {
265 struct trace_array *tr = graph_array;
266 struct trace_array_cpu *data;
267 unsigned long flags;
268 long disabled;
269 int cpu;
270 int pc;
271
272 local_irq_save(flags);
273 cpu = raw_smp_processor_id();
274 data = tr->data[cpu];
275 disabled = atomic_inc_return(&data->disabled);
276 if (likely(disabled == 1)) {
277 pc = preempt_count();
278 __trace_graph_return(tr, trace, flags, pc);
279 }
280 atomic_dec(&data->disabled);
281 local_irq_restore(flags);
282 }
283
284 void set_graph_array(struct trace_array *tr)
285 {
286 graph_array = tr;
287
288 /* Make graph_array visible before we start tracing */
289
290 smp_mb();
291 }
292
293 static int graph_trace_init(struct trace_array *tr)
294 {
295 int ret;
296
297 set_graph_array(tr);
298 ret = register_ftrace_graph(&trace_graph_return,
299 &trace_graph_entry);
300 if (ret)
301 return ret;
302 tracing_start_cmdline_record();
303
304 return 0;
305 }
306
307 static void graph_trace_reset(struct trace_array *tr)
308 {
309 tracing_stop_cmdline_record();
310 unregister_ftrace_graph();
311 }
312
313 static int max_bytes_for_cpu;
314
315 static enum print_line_t
316 print_graph_cpu(struct trace_seq *s, int cpu)
317 {
318 int ret;
319
320 /*
321 * Start with a space character - to make it stand out
322 * to the right a bit when trace output is pasted into
323 * email:
324 */
325 ret = trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu);
326 if (!ret)
327 return TRACE_TYPE_PARTIAL_LINE;
328
329 return TRACE_TYPE_HANDLED;
330 }
331
332 #define TRACE_GRAPH_PROCINFO_LENGTH 14
333
334 static enum print_line_t
335 print_graph_proc(struct trace_seq *s, pid_t pid)
336 {
337 char comm[TASK_COMM_LEN];
338 /* sign + log10(MAX_INT) + '\0' */
339 char pid_str[11];
340 int spaces = 0;
341 int ret;
342 int len;
343 int i;
344
345 trace_find_cmdline(pid, comm);
346 comm[7] = '\0';
347 sprintf(pid_str, "%d", pid);
348
349 /* 1 stands for the "-" character */
350 len = strlen(comm) + strlen(pid_str) + 1;
351
352 if (len < TRACE_GRAPH_PROCINFO_LENGTH)
353 spaces = TRACE_GRAPH_PROCINFO_LENGTH - len;
354
355 /* First spaces to align center */
356 for (i = 0; i < spaces / 2; i++) {
357 ret = trace_seq_printf(s, " ");
358 if (!ret)
359 return TRACE_TYPE_PARTIAL_LINE;
360 }
361
362 ret = trace_seq_printf(s, "%s-%s", comm, pid_str);
363 if (!ret)
364 return TRACE_TYPE_PARTIAL_LINE;
365
366 /* Last spaces to align center */
367 for (i = 0; i < spaces - (spaces / 2); i++) {
368 ret = trace_seq_printf(s, " ");
369 if (!ret)
370 return TRACE_TYPE_PARTIAL_LINE;
371 }
372 return TRACE_TYPE_HANDLED;
373 }
374
375
376 static enum print_line_t
377 print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
378 {
379 if (!trace_seq_putc(s, ' '))
380 return 0;
381
382 return trace_print_lat_fmt(s, entry);
383 }
384
385 /* If the pid changed since the last trace, output this event */
386 static enum print_line_t
387 verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
388 {
389 pid_t prev_pid;
390 pid_t *last_pid;
391 int ret;
392
393 if (!data)
394 return TRACE_TYPE_HANDLED;
395
396 last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
397
398 if (*last_pid == pid)
399 return TRACE_TYPE_HANDLED;
400
401 prev_pid = *last_pid;
402 *last_pid = pid;
403
404 if (prev_pid == -1)
405 return TRACE_TYPE_HANDLED;
406 /*
407 * Context-switch trace line:
408
409 ------------------------------------------
410 | 1) migration/0--1 => sshd-1755
411 ------------------------------------------
412
413 */
414 ret = trace_seq_printf(s,
415 " ------------------------------------------\n");
416 if (!ret)
417 return TRACE_TYPE_PARTIAL_LINE;
418
419 ret = print_graph_cpu(s, cpu);
420 if (ret == TRACE_TYPE_PARTIAL_LINE)
421 return TRACE_TYPE_PARTIAL_LINE;
422
423 ret = print_graph_proc(s, prev_pid);
424 if (ret == TRACE_TYPE_PARTIAL_LINE)
425 return TRACE_TYPE_PARTIAL_LINE;
426
427 ret = trace_seq_printf(s, " => ");
428 if (!ret)
429 return TRACE_TYPE_PARTIAL_LINE;
430
431 ret = print_graph_proc(s, pid);
432 if (ret == TRACE_TYPE_PARTIAL_LINE)
433 return TRACE_TYPE_PARTIAL_LINE;
434
435 ret = trace_seq_printf(s,
436 "\n ------------------------------------------\n\n");
437 if (!ret)
438 return TRACE_TYPE_PARTIAL_LINE;
439
440 return TRACE_TYPE_HANDLED;
441 }
442
443 static struct ftrace_graph_ret_entry *
444 get_return_for_leaf(struct trace_iterator *iter,
445 struct ftrace_graph_ent_entry *curr)
446 {
447 struct fgraph_data *data = iter->private;
448 struct ring_buffer_iter *ring_iter = NULL;
449 struct ring_buffer_event *event;
450 struct ftrace_graph_ret_entry *next;
451
452 /*
453 * If the previous output failed to write to the seq buffer,
454 * then we just reuse the data from before.
455 */
456 if (data && data->failed) {
457 curr = &data->ent;
458 next = &data->ret;
459 } else {
460
461 ring_iter = iter->buffer_iter[iter->cpu];
462
463 /* First peek to compare current entry and the next one */
464 if (ring_iter)
465 event = ring_buffer_iter_peek(ring_iter, NULL);
466 else {
467 /*
468 * We need to consume the current entry to see
469 * the next one.
470 */
471 ring_buffer_consume(iter->tr->buffer, iter->cpu, NULL);
472 event = ring_buffer_peek(iter->tr->buffer, iter->cpu,
473 NULL);
474 }
475
476 if (!event)
477 return NULL;
478
479 next = ring_buffer_event_data(event);
480
481 if (data) {
482 /*
483 * Save current and next entries for later reference
484 * if the output fails.
485 */
486 data->ent = *curr;
487 data->ret = *next;
488 }
489 }
490
491 if (next->ent.type != TRACE_GRAPH_RET)
492 return NULL;
493
494 if (curr->ent.pid != next->ent.pid ||
495 curr->graph_ent.func != next->ret.func)
496 return NULL;
497
498 /* this is a leaf, now advance the iterator */
499 if (ring_iter)
500 ring_buffer_read(ring_iter, NULL);
501
502 return next;
503 }
504
505 /* Signal a overhead of time execution to the output */
506 static int
507 print_graph_overhead(unsigned long long duration, struct trace_seq *s)
508 {
509 /* If duration disappear, we don't need anything */
510 if (!(tracer_flags.val & TRACE_GRAPH_PRINT_DURATION))
511 return 1;
512
513 /* Non nested entry or return */
514 if (duration == -1)
515 return trace_seq_printf(s, " ");
516
517 if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
518 /* Duration exceeded 100 msecs */
519 if (duration > 100000ULL)
520 return trace_seq_printf(s, "! ");
521
522 /* Duration exceeded 10 msecs */
523 if (duration > 10000ULL)
524 return trace_seq_printf(s, "+ ");
525 }
526
527 return trace_seq_printf(s, " ");
528 }
529
530 static int print_graph_abs_time(u64 t, struct trace_seq *s)
531 {
532 unsigned long usecs_rem;
533
534 usecs_rem = do_div(t, NSEC_PER_SEC);
535 usecs_rem /= 1000;
536
537 return trace_seq_printf(s, "%5lu.%06lu | ",
538 (unsigned long)t, usecs_rem);
539 }
540
541 static enum print_line_t
542 print_graph_irq(struct trace_iterator *iter, unsigned long addr,
543 enum trace_type type, int cpu, pid_t pid)
544 {
545 int ret;
546 struct trace_seq *s = &iter->seq;
547
548 if (addr < (unsigned long)__irqentry_text_start ||
549 addr >= (unsigned long)__irqentry_text_end)
550 return TRACE_TYPE_UNHANDLED;
551
552 /* Absolute time */
553 if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME) {
554 ret = print_graph_abs_time(iter->ts, s);
555 if (!ret)
556 return TRACE_TYPE_PARTIAL_LINE;
557 }
558
559 /* Cpu */
560 if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
561 ret = print_graph_cpu(s, cpu);
562 if (ret == TRACE_TYPE_PARTIAL_LINE)
563 return TRACE_TYPE_PARTIAL_LINE;
564 }
565
566 /* Proc */
567 if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
568 ret = print_graph_proc(s, pid);
569 if (ret == TRACE_TYPE_PARTIAL_LINE)
570 return TRACE_TYPE_PARTIAL_LINE;
571 ret = trace_seq_printf(s, " | ");
572 if (!ret)
573 return TRACE_TYPE_PARTIAL_LINE;
574 }
575
576 /* No overhead */
577 ret = print_graph_overhead(-1, s);
578 if (!ret)
579 return TRACE_TYPE_PARTIAL_LINE;
580
581 if (type == TRACE_GRAPH_ENT)
582 ret = trace_seq_printf(s, "==========>");
583 else
584 ret = trace_seq_printf(s, "<==========");
585
586 if (!ret)
587 return TRACE_TYPE_PARTIAL_LINE;
588
589 /* Don't close the duration column if haven't one */
590 if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION)
591 trace_seq_printf(s, " |");
592 ret = trace_seq_printf(s, "\n");
593
594 if (!ret)
595 return TRACE_TYPE_PARTIAL_LINE;
596 return TRACE_TYPE_HANDLED;
597 }
598
599 enum print_line_t
600 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
601 {
602 unsigned long nsecs_rem = do_div(duration, 1000);
603 /* log10(ULONG_MAX) + '\0' */
604 char msecs_str[21];
605 char nsecs_str[5];
606 int ret, len;
607 int i;
608
609 sprintf(msecs_str, "%lu", (unsigned long) duration);
610
611 /* Print msecs */
612 ret = trace_seq_printf(s, "%s", msecs_str);
613 if (!ret)
614 return TRACE_TYPE_PARTIAL_LINE;
615
616 len = strlen(msecs_str);
617
618 /* Print nsecs (we don't want to exceed 7 numbers) */
619 if (len < 7) {
620 snprintf(nsecs_str, 8 - len, "%03lu", nsecs_rem);
621 ret = trace_seq_printf(s, ".%s", nsecs_str);
622 if (!ret)
623 return TRACE_TYPE_PARTIAL_LINE;
624 len += strlen(nsecs_str);
625 }
626
627 ret = trace_seq_printf(s, " us ");
628 if (!ret)
629 return TRACE_TYPE_PARTIAL_LINE;
630
631 /* Print remaining spaces to fit the row's width */
632 for (i = len; i < 7; i++) {
633 ret = trace_seq_printf(s, " ");
634 if (!ret)
635 return TRACE_TYPE_PARTIAL_LINE;
636 }
637 return TRACE_TYPE_HANDLED;
638 }
639
640 static enum print_line_t
641 print_graph_duration(unsigned long long duration, struct trace_seq *s)
642 {
643 int ret;
644
645 ret = trace_print_graph_duration(duration, s);
646 if (ret != TRACE_TYPE_HANDLED)
647 return ret;
648
649 ret = trace_seq_printf(s, "| ");
650 if (!ret)
651 return TRACE_TYPE_PARTIAL_LINE;
652
653 return TRACE_TYPE_HANDLED;
654 }
655
656 /* Case of a leaf function on its call entry */
657 static enum print_line_t
658 print_graph_entry_leaf(struct trace_iterator *iter,
659 struct ftrace_graph_ent_entry *entry,
660 struct ftrace_graph_ret_entry *ret_entry, struct trace_seq *s)
661 {
662 struct fgraph_data *data = iter->private;
663 struct ftrace_graph_ret *graph_ret;
664 struct ftrace_graph_ent *call;
665 unsigned long long duration;
666 int ret;
667 int i;
668
669 graph_ret = &ret_entry->ret;
670 call = &entry->graph_ent;
671 duration = graph_ret->rettime - graph_ret->calltime;
672
673 if (data) {
674 struct fgraph_cpu_data *cpu_data;
675 int cpu = iter->cpu;
676
677 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
678
679 /*
680 * Comments display at + 1 to depth. Since
681 * this is a leaf function, keep the comments
682 * equal to this depth.
683 */
684 cpu_data->depth = call->depth - 1;
685
686 /* No need to keep this function around for this depth */
687 if (call->depth < FTRACE_RETFUNC_DEPTH)
688 cpu_data->enter_funcs[call->depth] = 0;
689 }
690
691 /* Overhead */
692 ret = print_graph_overhead(duration, s);
693 if (!ret)
694 return TRACE_TYPE_PARTIAL_LINE;
695
696 /* Duration */
697 if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) {
698 ret = print_graph_duration(duration, s);
699 if (ret == TRACE_TYPE_PARTIAL_LINE)
700 return TRACE_TYPE_PARTIAL_LINE;
701 }
702
703 /* Function */
704 for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
705 ret = trace_seq_printf(s, " ");
706 if (!ret)
707 return TRACE_TYPE_PARTIAL_LINE;
708 }
709
710 ret = trace_seq_printf(s, "%ps();\n", (void *)call->func);
711 if (!ret)
712 return TRACE_TYPE_PARTIAL_LINE;
713
714 return TRACE_TYPE_HANDLED;
715 }
716
717 static enum print_line_t
718 print_graph_entry_nested(struct trace_iterator *iter,
719 struct ftrace_graph_ent_entry *entry,
720 struct trace_seq *s, int cpu)
721 {
722 struct ftrace_graph_ent *call = &entry->graph_ent;
723 struct fgraph_data *data = iter->private;
724 int ret;
725 int i;
726
727 if (data) {
728 struct fgraph_cpu_data *cpu_data;
729 int cpu = iter->cpu;
730
731 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
732 cpu_data->depth = call->depth;
733
734 /* Save this function pointer to see if the exit matches */
735 if (call->depth < FTRACE_RETFUNC_DEPTH)
736 cpu_data->enter_funcs[call->depth] = call->func;
737 }
738
739 /* No overhead */
740 ret = print_graph_overhead(-1, s);
741 if (!ret)
742 return TRACE_TYPE_PARTIAL_LINE;
743
744 /* No time */
745 if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) {
746 ret = trace_seq_printf(s, " | ");
747 if (!ret)
748 return TRACE_TYPE_PARTIAL_LINE;
749 }
750
751 /* Function */
752 for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
753 ret = trace_seq_printf(s, " ");
754 if (!ret)
755 return TRACE_TYPE_PARTIAL_LINE;
756 }
757
758 ret = trace_seq_printf(s, "%ps() {\n", (void *)call->func);
759 if (!ret)
760 return TRACE_TYPE_PARTIAL_LINE;
761
762 /*
763 * we already consumed the current entry to check the next one
764 * and see if this is a leaf.
765 */
766 return TRACE_TYPE_NO_CONSUME;
767 }
768
769 static enum print_line_t
770 print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
771 int type, unsigned long addr)
772 {
773 struct fgraph_data *data = iter->private;
774 struct trace_entry *ent = iter->ent;
775 int cpu = iter->cpu;
776 int ret;
777
778 /* Pid */
779 if (verif_pid(s, ent->pid, cpu, data) == TRACE_TYPE_PARTIAL_LINE)
780 return TRACE_TYPE_PARTIAL_LINE;
781
782 if (type) {
783 /* Interrupt */
784 ret = print_graph_irq(iter, addr, type, cpu, ent->pid);
785 if (ret == TRACE_TYPE_PARTIAL_LINE)
786 return TRACE_TYPE_PARTIAL_LINE;
787 }
788
789 /* Absolute time */
790 if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME) {
791 ret = print_graph_abs_time(iter->ts, s);
792 if (!ret)
793 return TRACE_TYPE_PARTIAL_LINE;
794 }
795
796 /* Cpu */
797 if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
798 ret = print_graph_cpu(s, cpu);
799 if (ret == TRACE_TYPE_PARTIAL_LINE)
800 return TRACE_TYPE_PARTIAL_LINE;
801 }
802
803 /* Proc */
804 if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
805 ret = print_graph_proc(s, ent->pid);
806 if (ret == TRACE_TYPE_PARTIAL_LINE)
807 return TRACE_TYPE_PARTIAL_LINE;
808
809 ret = trace_seq_printf(s, " | ");
810 if (!ret)
811 return TRACE_TYPE_PARTIAL_LINE;
812 }
813
814 /* Latency format */
815 if (trace_flags & TRACE_ITER_LATENCY_FMT) {
816 ret = print_graph_lat_fmt(s, ent);
817 if (ret == TRACE_TYPE_PARTIAL_LINE)
818 return TRACE_TYPE_PARTIAL_LINE;
819 }
820
821 return 0;
822 }
823
824 static enum print_line_t
825 print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
826 struct trace_iterator *iter)
827 {
828 struct fgraph_data *data = iter->private;
829 struct ftrace_graph_ent *call = &field->graph_ent;
830 struct ftrace_graph_ret_entry *leaf_ret;
831 static enum print_line_t ret;
832 int cpu = iter->cpu;
833
834 if (print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func))
835 return TRACE_TYPE_PARTIAL_LINE;
836
837 leaf_ret = get_return_for_leaf(iter, field);
838 if (leaf_ret)
839 ret = print_graph_entry_leaf(iter, field, leaf_ret, s);
840 else
841 ret = print_graph_entry_nested(iter, field, s, cpu);
842
843 if (data) {
844 /*
845 * If we failed to write our output, then we need to make
846 * note of it. Because we already consumed our entry.
847 */
848 if (s->full) {
849 data->failed = 1;
850 data->cpu = cpu;
851 } else
852 data->failed = 0;
853 }
854
855 return ret;
856 }
857
858 static enum print_line_t
859 print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
860 struct trace_entry *ent, struct trace_iterator *iter)
861 {
862 unsigned long long duration = trace->rettime - trace->calltime;
863 struct fgraph_data *data = iter->private;
864 pid_t pid = ent->pid;
865 int cpu = iter->cpu;
866 int func_match = 1;
867 int ret;
868 int i;
869
870 if (data) {
871 struct fgraph_cpu_data *cpu_data;
872 int cpu = iter->cpu;
873
874 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
875
876 /*
877 * Comments display at + 1 to depth. This is the
878 * return from a function, we now want the comments
879 * to display at the same level of the bracket.
880 */
881 cpu_data->depth = trace->depth - 1;
882
883 if (trace->depth < FTRACE_RETFUNC_DEPTH) {
884 if (cpu_data->enter_funcs[trace->depth] != trace->func)
885 func_match = 0;
886 cpu_data->enter_funcs[trace->depth] = 0;
887 }
888 }
889
890 if (print_graph_prologue(iter, s, 0, 0))
891 return TRACE_TYPE_PARTIAL_LINE;
892
893 /* Overhead */
894 ret = print_graph_overhead(duration, s);
895 if (!ret)
896 return TRACE_TYPE_PARTIAL_LINE;
897
898 /* Duration */
899 if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) {
900 ret = print_graph_duration(duration, s);
901 if (ret == TRACE_TYPE_PARTIAL_LINE)
902 return TRACE_TYPE_PARTIAL_LINE;
903 }
904
905 /* Closing brace */
906 for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
907 ret = trace_seq_printf(s, " ");
908 if (!ret)
909 return TRACE_TYPE_PARTIAL_LINE;
910 }
911
912 /*
913 * If the return function does not have a matching entry,
914 * then the entry was lost. Instead of just printing
915 * the '}' and letting the user guess what function this
916 * belongs to, write out the function name.
917 */
918 if (func_match) {
919 ret = trace_seq_printf(s, "}\n");
920 if (!ret)
921 return TRACE_TYPE_PARTIAL_LINE;
922 } else {
923 ret = trace_seq_printf(s, "} (%ps)\n", (void *)trace->func);
924 if (!ret)
925 return TRACE_TYPE_PARTIAL_LINE;
926 }
927
928 /* Overrun */
929 if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) {
930 ret = trace_seq_printf(s, " (Overruns: %lu)\n",
931 trace->overrun);
932 if (!ret)
933 return TRACE_TYPE_PARTIAL_LINE;
934 }
935
936 ret = print_graph_irq(iter, trace->func, TRACE_GRAPH_RET, cpu, pid);
937 if (ret == TRACE_TYPE_PARTIAL_LINE)
938 return TRACE_TYPE_PARTIAL_LINE;
939
940 return TRACE_TYPE_HANDLED;
941 }
942
943 static enum print_line_t
944 print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
945 struct trace_iterator *iter)
946 {
947 unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
948 struct fgraph_data *data = iter->private;
949 struct trace_event *event;
950 int depth = 0;
951 int ret;
952 int i;
953
954 if (data)
955 depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth;
956
957 if (print_graph_prologue(iter, s, 0, 0))
958 return TRACE_TYPE_PARTIAL_LINE;
959
960 /* No overhead */
961 ret = print_graph_overhead(-1, s);
962 if (!ret)
963 return TRACE_TYPE_PARTIAL_LINE;
964
965 /* No time */
966 if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) {
967 ret = trace_seq_printf(s, " | ");
968 if (!ret)
969 return TRACE_TYPE_PARTIAL_LINE;
970 }
971
972 /* Indentation */
973 if (depth > 0)
974 for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++) {
975 ret = trace_seq_printf(s, " ");
976 if (!ret)
977 return TRACE_TYPE_PARTIAL_LINE;
978 }
979
980 /* The comment */
981 ret = trace_seq_printf(s, "/* ");
982 if (!ret)
983 return TRACE_TYPE_PARTIAL_LINE;
984
985 switch (iter->ent->type) {
986 case TRACE_BPRINT:
987 ret = trace_print_bprintk_msg_only(iter);
988 if (ret != TRACE_TYPE_HANDLED)
989 return ret;
990 break;
991 case TRACE_PRINT:
992 ret = trace_print_printk_msg_only(iter);
993 if (ret != TRACE_TYPE_HANDLED)
994 return ret;
995 break;
996 default:
997 event = ftrace_find_event(ent->type);
998 if (!event)
999 return TRACE_TYPE_UNHANDLED;
1000
1001 ret = event->trace(iter, sym_flags);
1002 if (ret != TRACE_TYPE_HANDLED)
1003 return ret;
1004 }
1005
1006 /* Strip ending newline */
1007 if (s->buffer[s->len - 1] == '\n') {
1008 s->buffer[s->len - 1] = '\0';
1009 s->len--;
1010 }
1011
1012 ret = trace_seq_printf(s, " */\n");
1013 if (!ret)
1014 return TRACE_TYPE_PARTIAL_LINE;
1015
1016 return TRACE_TYPE_HANDLED;
1017 }
1018
1019
1020 enum print_line_t
1021 print_graph_function(struct trace_iterator *iter)
1022 {
1023 struct ftrace_graph_ent_entry *field;
1024 struct fgraph_data *data = iter->private;
1025 struct trace_entry *entry = iter->ent;
1026 struct trace_seq *s = &iter->seq;
1027 int cpu = iter->cpu;
1028 int ret;
1029
1030 if (data && per_cpu_ptr(data->cpu_data, cpu)->ignore) {
1031 per_cpu_ptr(data->cpu_data, cpu)->ignore = 0;
1032 return TRACE_TYPE_HANDLED;
1033 }
1034
1035 /*
1036 * If the last output failed, there's a possibility we need
1037 * to print out the missing entry which would never go out.
1038 */
1039 if (data && data->failed) {
1040 field = &data->ent;
1041 iter->cpu = data->cpu;
1042 ret = print_graph_entry(field, s, iter);
1043 if (ret == TRACE_TYPE_HANDLED && iter->cpu != cpu) {
1044 per_cpu_ptr(data->cpu_data, iter->cpu)->ignore = 1;
1045 ret = TRACE_TYPE_NO_CONSUME;
1046 }
1047 iter->cpu = cpu;
1048 return ret;
1049 }
1050
1051 switch (entry->type) {
1052 case TRACE_GRAPH_ENT: {
1053 /*
1054 * print_graph_entry() may consume the current event,
1055 * thus @field may become invalid, so we need to save it.
1056 * sizeof(struct ftrace_graph_ent_entry) is very small,
1057 * it can be safely saved at the stack.
1058 */
1059 struct ftrace_graph_ent_entry saved;
1060 trace_assign_type(field, entry);
1061 saved = *field;
1062 return print_graph_entry(&saved, s, iter);
1063 }
1064 case TRACE_GRAPH_RET: {
1065 struct ftrace_graph_ret_entry *field;
1066 trace_assign_type(field, entry);
1067 return print_graph_return(&field->ret, s, entry, iter);
1068 }
1069 default:
1070 return print_graph_comment(s, entry, iter);
1071 }
1072
1073 return TRACE_TYPE_HANDLED;
1074 }
1075
1076 static void print_lat_header(struct seq_file *s)
1077 {
1078 static const char spaces[] = " " /* 16 spaces */
1079 " " /* 4 spaces */
1080 " "; /* 17 spaces */
1081 int size = 0;
1082
1083 if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME)
1084 size += 16;
1085 if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU)
1086 size += 4;
1087 if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC)
1088 size += 17;
1089
1090 seq_printf(s, "#%.*s _-----=> irqs-off \n", size, spaces);
1091 seq_printf(s, "#%.*s / _----=> need-resched \n", size, spaces);
1092 seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces);
1093 seq_printf(s, "#%.*s|| / _--=> preempt-depth \n", size, spaces);
1094 seq_printf(s, "#%.*s||| / _-=> lock-depth \n", size, spaces);
1095 seq_printf(s, "#%.*s|||| / \n", size, spaces);
1096 }
1097
1098 static void print_graph_headers(struct seq_file *s)
1099 {
1100 int lat = trace_flags & TRACE_ITER_LATENCY_FMT;
1101
1102 if (lat)
1103 print_lat_header(s);
1104
1105 /* 1st line */
1106 seq_printf(s, "#");
1107 if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME)
1108 seq_printf(s, " TIME ");
1109 if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU)
1110 seq_printf(s, " CPU");
1111 if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC)
1112 seq_printf(s, " TASK/PID ");
1113 if (lat)
1114 seq_printf(s, "|||||");
1115 if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION)
1116 seq_printf(s, " DURATION ");
1117 seq_printf(s, " FUNCTION CALLS\n");
1118
1119 /* 2nd line */
1120 seq_printf(s, "#");
1121 if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME)
1122 seq_printf(s, " | ");
1123 if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU)
1124 seq_printf(s, " | ");
1125 if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC)
1126 seq_printf(s, " | | ");
1127 if (lat)
1128 seq_printf(s, "|||||");
1129 if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION)
1130 seq_printf(s, " | | ");
1131 seq_printf(s, " | | | |\n");
1132 }
1133
1134 static void graph_trace_open(struct trace_iterator *iter)
1135 {
1136 /* pid and depth on the last trace processed */
1137 struct fgraph_data *data;
1138 int cpu;
1139
1140 iter->private = NULL;
1141
1142 data = kzalloc(sizeof(*data), GFP_KERNEL);
1143 if (!data)
1144 goto out_err;
1145
1146 data->cpu_data = alloc_percpu(struct fgraph_cpu_data);
1147 if (!data->cpu_data)
1148 goto out_err_free;
1149
1150 for_each_possible_cpu(cpu) {
1151 pid_t *pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
1152 int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
1153 int *ignore = &(per_cpu_ptr(data->cpu_data, cpu)->ignore);
1154 *pid = -1;
1155 *depth = 0;
1156 *ignore = 0;
1157 }
1158
1159 iter->private = data;
1160
1161 return;
1162
1163 out_err_free:
1164 kfree(data);
1165 out_err:
1166 pr_warning("function graph tracer: not enough memory\n");
1167 }
1168
1169 static void graph_trace_close(struct trace_iterator *iter)
1170 {
1171 struct fgraph_data *data = iter->private;
1172
1173 if (data) {
1174 free_percpu(data->cpu_data);
1175 kfree(data);
1176 }
1177 }
1178
1179 static struct tracer graph_trace __read_mostly = {
1180 .name = "function_graph",
1181 .open = graph_trace_open,
1182 .pipe_open = graph_trace_open,
1183 .close = graph_trace_close,
1184 .pipe_close = graph_trace_close,
1185 .wait_pipe = poll_wait_pipe,
1186 .init = graph_trace_init,
1187 .reset = graph_trace_reset,
1188 .print_line = print_graph_function,
1189 .print_header = print_graph_headers,
1190 .flags = &tracer_flags,
1191 #ifdef CONFIG_FTRACE_SELFTEST
1192 .selftest = trace_selftest_startup_function_graph,
1193 #endif
1194 };
1195
1196 static __init int init_graph_trace(void)
1197 {
1198 max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1);
1199
1200 return register_tracer(&graph_trace);
1201 }
1202
1203 device_initcall(init_graph_trace);
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree