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added 2.6.29.6 aldebaran kernel
[nao-ulib.git] / kernel / 2.6.29.6-aldebaran-rt / kernel / trace / trace_functions_graph.c
blobe352d82845209e86a4b53ea71fd8e56d5639e9d8
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_data {
18 pid_t last_pid;
19 int depth;
20 };
21
22 #define TRACE_GRAPH_INDENT 2
23
24 /* Flag options */
25 #define TRACE_GRAPH_PRINT_OVERRUN 0x1
26 #define TRACE_GRAPH_PRINT_CPU 0x2
27 #define TRACE_GRAPH_PRINT_OVERHEAD 0x4
28 #define TRACE_GRAPH_PRINT_PROC 0x8
29 #define TRACE_GRAPH_PRINT_DURATION 0x10
30 #define TRACE_GRAPH_PRINT_ABS_TIME 0X20
31
32 static struct tracer_opt trace_opts[] = {
33 /* Display overruns? (for self-debug purpose) */
34 { TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) },
35 /* Display CPU ? */
36 { TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },
37 /* Display Overhead ? */
38 { TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },
39 /* Display proc name/pid */
40 { TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) },
41 /* Display duration of execution */
42 { TRACER_OPT(funcgraph-duration, TRACE_GRAPH_PRINT_DURATION) },
43 /* Display absolute time of an entry */
44 { TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) },
45 { } /* Empty entry */
46 };
47
48 static struct tracer_flags tracer_flags = {
49 /* Don't display overruns and proc by default */
50 .val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD |
51 TRACE_GRAPH_PRINT_DURATION,
52 .opts = trace_opts
53 };
54
55 /* pid on the last trace processed */
56
57
58 /* Add a function return address to the trace stack on thread info.*/
59 int
60 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth)
61 {
62 unsigned long long calltime;
63 int index;
64
65 if (!current->ret_stack)
66 return -EBUSY;
67
68 /* The return trace stack is full */
69 if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
70 atomic_inc(&current->trace_overrun);
71 return -EBUSY;
72 }
73
74 calltime = trace_clock_local();
75
76 index = ++current->curr_ret_stack;
77 barrier();
78 current->ret_stack[index].ret = ret;
79 current->ret_stack[index].func = func;
80 current->ret_stack[index].calltime = calltime;
81 current->ret_stack[index].subtime = 0;
82 *depth = index;
83
84 return 0;
85 }
86
87 /* Retrieve a function return address to the trace stack on thread info.*/
88 static void
89 ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret)
90 {
91 int index;
92
93 index = current->curr_ret_stack;
94
95 if (unlikely(index < 0)) {
96 ftrace_graph_stop();
97 WARN_ON(1);
98 /* Might as well panic, otherwise we have no where to go */
99 *ret = (unsigned long)panic;
100 return;
101 }
102
103 *ret = current->ret_stack[index].ret;
104 trace->func = current->ret_stack[index].func;
105 trace->calltime = current->ret_stack[index].calltime;
106 trace->overrun = atomic_read(&current->trace_overrun);
107 trace->depth = index;
108 }
109
110 /*
111 * Send the trace to the ring-buffer.
112 * @return the original return address.
113 */
114 unsigned long ftrace_return_to_handler(void)
115 {
116 struct ftrace_graph_ret trace;
117 unsigned long ret;
118
119 ftrace_pop_return_trace(&trace, &ret);
120 trace.rettime = trace_clock_local();
121 ftrace_graph_return(&trace);
122 barrier();
123 current->curr_ret_stack--;
124
125 if (unlikely(!ret)) {
126 ftrace_graph_stop();
127 WARN_ON(1);
128 /* Might as well panic. What else to do? */
129 ret = (unsigned long)panic;
130 }
131
132 return ret;
133 }
134
135 static int graph_trace_init(struct trace_array *tr)
136 {
137 int ret = register_ftrace_graph(&trace_graph_return,
138 &trace_graph_entry);
139 if (ret)
140 return ret;
141 tracing_start_cmdline_record();
142
143 return 0;
144 }
145
146 static void graph_trace_reset(struct trace_array *tr)
147 {
148 tracing_stop_cmdline_record();
149 unregister_ftrace_graph();
150 }
151
152 static inline int log10_cpu(int nb)
153 {
154 if (nb / 100)
155 return 3;
156 if (nb / 10)
157 return 2;
158 return 1;
159 }
160
161 static enum print_line_t
162 print_graph_cpu(struct trace_seq *s, int cpu)
163 {
164 int i;
165 int ret;
166 int log10_this = log10_cpu(cpu);
167 int log10_all = log10_cpu(cpumask_weight(cpu_online_mask));
168
169
170 /*
171 * Start with a space character - to make it stand out
172 * to the right a bit when trace output is pasted into
173 * email:
174 */
175 ret = trace_seq_printf(s, " ");
176
177 /*
178 * Tricky - we space the CPU field according to the max
179 * number of online CPUs. On a 2-cpu system it would take
180 * a maximum of 1 digit - on a 128 cpu system it would
181 * take up to 3 digits:
182 */
183 for (i = 0; i < log10_all - log10_this; i++) {
184 ret = trace_seq_printf(s, " ");
185 if (!ret)
186 return TRACE_TYPE_PARTIAL_LINE;
187 }
188 ret = trace_seq_printf(s, "%d) ", cpu);
189 if (!ret)
190 return TRACE_TYPE_PARTIAL_LINE;
191
192 return TRACE_TYPE_HANDLED;
193 }
194
195 #define TRACE_GRAPH_PROCINFO_LENGTH 14
196
197 static enum print_line_t
198 print_graph_proc(struct trace_seq *s, pid_t pid)
199 {
200 char comm[TASK_COMM_LEN];
201 /* sign + log10(MAX_INT) + '\0' */
202 char pid_str[11];
203 int spaces = 0;
204 int ret;
205 int len;
206 int i;
207
208 trace_find_cmdline(pid, comm);
209 comm[7] = '\0';
210 sprintf(pid_str, "%d", pid);
211
212 /* 1 stands for the "-" character */
213 len = strlen(comm) + strlen(pid_str) + 1;
214
215 if (len < TRACE_GRAPH_PROCINFO_LENGTH)
216 spaces = TRACE_GRAPH_PROCINFO_LENGTH - len;
217
218 /* First spaces to align center */
219 for (i = 0; i < spaces / 2; i++) {
220 ret = trace_seq_printf(s, " ");
221 if (!ret)
222 return TRACE_TYPE_PARTIAL_LINE;
223 }
224
225 ret = trace_seq_printf(s, "%s-%s", comm, pid_str);
226 if (!ret)
227 return TRACE_TYPE_PARTIAL_LINE;
228
229 /* Last spaces to align center */
230 for (i = 0; i < spaces - (spaces / 2); i++) {
231 ret = trace_seq_printf(s, " ");
232 if (!ret)
233 return TRACE_TYPE_PARTIAL_LINE;
234 }
235 return TRACE_TYPE_HANDLED;
236 }
237
238
239 /* If the pid changed since the last trace, output this event */
240 static enum print_line_t
241 verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
242 {
243 pid_t prev_pid;
244 pid_t *last_pid;
245 int ret;
246
247 if (!data)
248 return TRACE_TYPE_HANDLED;
249
250 last_pid = &(per_cpu_ptr(data, cpu)->last_pid);
251
252 if (*last_pid == pid)
253 return TRACE_TYPE_HANDLED;
254
255 prev_pid = *last_pid;
256 *last_pid = pid;
257
258 if (prev_pid == -1)
259 return TRACE_TYPE_HANDLED;
260 /*
261 * Context-switch trace line:
262
263 ------------------------------------------
264 | 1) migration/0--1 => sshd-1755
265 ------------------------------------------
266
267 */
268 ret = trace_seq_printf(s,
269 " ------------------------------------------\n");
270 if (!ret)
271 return TRACE_TYPE_PARTIAL_LINE;
272
273 ret = print_graph_cpu(s, cpu);
274 if (ret == TRACE_TYPE_PARTIAL_LINE)
275 return TRACE_TYPE_PARTIAL_LINE;
276
277 ret = print_graph_proc(s, prev_pid);
278 if (ret == TRACE_TYPE_PARTIAL_LINE)
279 return TRACE_TYPE_PARTIAL_LINE;
280
281 ret = trace_seq_printf(s, " => ");
282 if (!ret)
283 return TRACE_TYPE_PARTIAL_LINE;
284
285 ret = print_graph_proc(s, pid);
286 if (ret == TRACE_TYPE_PARTIAL_LINE)
287 return TRACE_TYPE_PARTIAL_LINE;
288
289 ret = trace_seq_printf(s,
290 "\n ------------------------------------------\n\n");
291 if (!ret)
292 return TRACE_TYPE_PARTIAL_LINE;
293
294 return TRACE_TYPE_HANDLED;
295 }
296
297 static struct ftrace_graph_ret_entry *
298 get_return_for_leaf(struct trace_iterator *iter,
299 struct ftrace_graph_ent_entry *curr)
300 {
301 struct ring_buffer_iter *ring_iter;
302 struct ring_buffer_event *event;
303 struct ftrace_graph_ret_entry *next;
304
305 ring_iter = iter->buffer_iter[iter->cpu];
306
307 /* First peek to compare current entry and the next one */
308 if (ring_iter)
309 event = ring_buffer_iter_peek(ring_iter, NULL);
310 else {
311 /* We need to consume the current entry to see the next one */
312 ring_buffer_consume(iter->tr->buffer, iter->cpu, NULL);
313 event = ring_buffer_peek(iter->tr->buffer, iter->cpu,
314 NULL);
315 }
316
317 if (!event)
318 return NULL;
319
320 next = ring_buffer_event_data(event);
321
322 if (next->ent.type != TRACE_GRAPH_RET)
323 return NULL;
324
325 if (curr->ent.pid != next->ent.pid ||
326 curr->graph_ent.func != next->ret.func)
327 return NULL;
328
329 /* this is a leaf, now advance the iterator */
330 if (ring_iter)
331 ring_buffer_read(ring_iter, NULL);
332
333 return next;
334 }
335
336 /* Signal a overhead of time execution to the output */
337 static int
338 print_graph_overhead(unsigned long long duration, struct trace_seq *s)
339 {
340 /* If duration disappear, we don't need anything */
341 if (!(tracer_flags.val & TRACE_GRAPH_PRINT_DURATION))
342 return 1;
343
344 /* Non nested entry or return */
345 if (duration == -1)
346 return trace_seq_printf(s, " ");
347
348 if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
349 /* Duration exceeded 100 msecs */
350 if (duration > 100000ULL)
351 return trace_seq_printf(s, "! ");
352
353 /* Duration exceeded 10 msecs */
354 if (duration > 10000ULL)
355 return trace_seq_printf(s, "+ ");
356 }
357
358 return trace_seq_printf(s, " ");
359 }
360
361 static int print_graph_abs_time(u64 t, struct trace_seq *s)
362 {
363 unsigned long usecs_rem;
364
365 usecs_rem = do_div(t, NSEC_PER_SEC);
366 usecs_rem /= 1000;
367
368 return trace_seq_printf(s, "%5lu.%06lu | ",
369 (unsigned long)t, usecs_rem);
370 }
371
372 static enum print_line_t
373 print_graph_irq(struct trace_iterator *iter, unsigned long addr,
374 enum trace_type type, int cpu, pid_t pid)
375 {
376 int ret;
377 struct trace_seq *s = &iter->seq;
378
379 if (addr < (unsigned long)__irqentry_text_start ||
380 addr >= (unsigned long)__irqentry_text_end)
381 return TRACE_TYPE_UNHANDLED;
382
383 /* Absolute time */
384 if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME) {
385 ret = print_graph_abs_time(iter->ts, s);
386 if (!ret)
387 return TRACE_TYPE_PARTIAL_LINE;
388 }
389
390 /* Cpu */
391 if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
392 ret = print_graph_cpu(s, cpu);
393 if (ret == TRACE_TYPE_PARTIAL_LINE)
394 return TRACE_TYPE_PARTIAL_LINE;
395 }
396 /* Proc */
397 if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
398 ret = print_graph_proc(s, pid);
399 if (ret == TRACE_TYPE_PARTIAL_LINE)
400 return TRACE_TYPE_PARTIAL_LINE;
401 ret = trace_seq_printf(s, " | ");
402 if (!ret)
403 return TRACE_TYPE_PARTIAL_LINE;
404 }
405
406 /* No overhead */
407 ret = print_graph_overhead(-1, s);
408 if (!ret)
409 return TRACE_TYPE_PARTIAL_LINE;
410
411 if (type == TRACE_GRAPH_ENT)
412 ret = trace_seq_printf(s, "==========>");
413 else
414 ret = trace_seq_printf(s, "<==========");
415
416 if (!ret)
417 return TRACE_TYPE_PARTIAL_LINE;
418
419 /* Don't close the duration column if haven't one */
420 if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION)
421 trace_seq_printf(s, " |");
422 ret = trace_seq_printf(s, "\n");
423
424 if (!ret)
425 return TRACE_TYPE_PARTIAL_LINE;
426 return TRACE_TYPE_HANDLED;
427 }
428
429 enum print_line_t
430 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
431 {
432 unsigned long nsecs_rem = do_div(duration, 1000);
433 /* log10(ULONG_MAX) + '\0' */
434 char msecs_str[21];
435 char nsecs_str[5];
436 int ret, len;
437 int i;
438
439 snprintf(msecs_str, sizeof(msecs_str), "%lu", (unsigned long) duration);
440
441 /* Print msecs */
442 ret = trace_seq_printf(s, "%s", msecs_str);
443 if (!ret)
444 return TRACE_TYPE_PARTIAL_LINE;
445
446 len = strlen(msecs_str);
447
448 /* Print nsecs (we don't want to exceed 7 numbers) */
449 if (len < 7) {
450 snprintf(nsecs_str, 8 - len, "%03lu", nsecs_rem);
451 ret = trace_seq_printf(s, ".%s", nsecs_str);
452 if (!ret)
453 return TRACE_TYPE_PARTIAL_LINE;
454 len += strlen(nsecs_str);
455 }
456
457 ret = trace_seq_printf(s, " us ");
458 if (!ret)
459 return TRACE_TYPE_PARTIAL_LINE;
460
461 /* Print remaining spaces to fit the row's width */
462 for (i = len; i < 7; i++) {
463 ret = trace_seq_printf(s, " ");
464 if (!ret)
465 return TRACE_TYPE_PARTIAL_LINE;
466 }
467 return TRACE_TYPE_HANDLED;
468 }
469
470 static enum print_line_t
471 print_graph_duration(unsigned long long duration, struct trace_seq *s)
472 {
473 int ret;
474
475 ret = trace_print_graph_duration(duration, s);
476 if (ret != TRACE_TYPE_HANDLED)
477 return ret;
478
479 ret = trace_seq_printf(s, "| ");
480 if (!ret)
481 return TRACE_TYPE_PARTIAL_LINE;
482
483 return TRACE_TYPE_HANDLED;
484 }
485
486 /* Case of a leaf function on its call entry */
487 static enum print_line_t
488 print_graph_entry_leaf(struct trace_iterator *iter,
489 struct ftrace_graph_ent_entry *entry,
490 struct ftrace_graph_ret_entry *ret_entry, struct trace_seq *s)
491 {
492 struct fgraph_data *data = iter->private;
493 struct ftrace_graph_ret *graph_ret;
494 struct ftrace_graph_ent *call;
495 unsigned long long duration;
496 int ret;
497 int i;
498
499 graph_ret = &ret_entry->ret;
500 call = &entry->graph_ent;
501 duration = graph_ret->rettime - graph_ret->calltime;
502
503 if (data) {
504 int cpu = iter->cpu;
505 int *depth = &(per_cpu_ptr(data, cpu)->depth);
506
507 /*
508 * Comments display at + 1 to depth. Since
509 * this is a leaf function, keep the comments
510 * equal to this depth.
511 */
512 *depth = call->depth - 1;
513 }
514
515 /* Overhead */
516 ret = print_graph_overhead(duration, s);
517 if (!ret)
518 return TRACE_TYPE_PARTIAL_LINE;
519
520 /* Duration */
521 if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) {
522 ret = print_graph_duration(duration, s);
523 if (ret == TRACE_TYPE_PARTIAL_LINE)
524 return TRACE_TYPE_PARTIAL_LINE;
525 }
526
527 /* Function */
528 for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
529 ret = trace_seq_printf(s, " ");
530 if (!ret)
531 return TRACE_TYPE_PARTIAL_LINE;
532 }
533
534 ret = seq_print_ip_sym(s, call->func, 0);
535 if (!ret)
536 return TRACE_TYPE_PARTIAL_LINE;
537
538 ret = trace_seq_printf(s, "();\n");
539 if (!ret)
540 return TRACE_TYPE_PARTIAL_LINE;
541
542 return TRACE_TYPE_HANDLED;
543 }
544
545 static enum print_line_t
546 print_graph_entry_nested(struct trace_iterator *iter,
547 struct ftrace_graph_ent_entry *entry,
548 struct trace_seq *s, int cpu)
549 {
550 struct ftrace_graph_ent *call = &entry->graph_ent;
551 struct fgraph_data *data = iter->private;
552 int ret;
553 int i;
554
555 if (data) {
556 int cpu = iter->cpu;
557 int *depth = &(per_cpu_ptr(data, cpu)->depth);
558
559 *depth = call->depth;
560 }
561
562 /* No overhead */
563 ret = print_graph_overhead(-1, s);
564 if (!ret)
565 return TRACE_TYPE_PARTIAL_LINE;
566
567 /* No time */
568 if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) {
569 ret = trace_seq_printf(s, " | ");
570 if (!ret)
571 return TRACE_TYPE_PARTIAL_LINE;
572 }
573
574 /* Function */
575 for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
576 ret = trace_seq_printf(s, " ");
577 if (!ret)
578 return TRACE_TYPE_PARTIAL_LINE;
579 }
580
581 ret = seq_print_ip_sym(s, call->func, 0);
582 if (!ret)
583 return TRACE_TYPE_PARTIAL_LINE;
584
585 ret = trace_seq_printf(s, "() {\n");
586 if (!ret)
587 return TRACE_TYPE_PARTIAL_LINE;
588
589 /*
590 * we already consumed the current entry to check the next one
591 * and see if this is a leaf.
592 */
593 return TRACE_TYPE_NO_CONSUME;
594 }
595
596 static enum print_line_t
597 print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
598 int type, unsigned long addr)
599 {
600 struct fgraph_data *data = iter->private;
601 struct trace_entry *ent = iter->ent;
602 int cpu = iter->cpu;
603 int ret;
604
605 /* Pid */
606 if (verif_pid(s, ent->pid, cpu, data) == TRACE_TYPE_PARTIAL_LINE)
607 return TRACE_TYPE_PARTIAL_LINE;
608
609 if (type) {
610 /* Interrupt */
611 ret = print_graph_irq(iter, addr, type, cpu, ent->pid);
612 if (ret == TRACE_TYPE_PARTIAL_LINE)
613 return TRACE_TYPE_PARTIAL_LINE;
614 }
615
616 /* Absolute time */
617 if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME) {
618 ret = print_graph_abs_time(iter->ts, s);
619 if (!ret)
620 return TRACE_TYPE_PARTIAL_LINE;
621 }
622
623 /* Cpu */
624 if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
625 ret = print_graph_cpu(s, cpu);
626 if (ret == TRACE_TYPE_PARTIAL_LINE)
627 return TRACE_TYPE_PARTIAL_LINE;
628 }
629
630 /* Proc */
631 if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
632 ret = print_graph_proc(s, ent->pid);
633 if (ret == TRACE_TYPE_PARTIAL_LINE)
634 return TRACE_TYPE_PARTIAL_LINE;
635
636 ret = trace_seq_printf(s, " | ");
637 if (!ret)
638 return TRACE_TYPE_PARTIAL_LINE;
639 }
640
641 return 0;
642 }
643
644 static enum print_line_t
645 print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
646 struct trace_iterator *iter)
647 {
648 int cpu = iter->cpu;
649 struct ftrace_graph_ent *call = &field->graph_ent;
650 struct ftrace_graph_ret_entry *leaf_ret;
651
652 if (print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func))
653 return TRACE_TYPE_PARTIAL_LINE;
654
655 leaf_ret = get_return_for_leaf(iter, field);
656 if (leaf_ret)
657 return print_graph_entry_leaf(iter, field, leaf_ret, s);
658 else
659 return print_graph_entry_nested(iter, field, s, cpu);
660
661 }
662
663 static enum print_line_t
664 print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
665 struct trace_entry *ent, struct trace_iterator *iter)
666 {
667 unsigned long long duration = trace->rettime - trace->calltime;
668 struct fgraph_data *data = iter->private;
669 pid_t pid = ent->pid;
670 int cpu = iter->cpu;
671 int ret;
672 int i;
673
674 if (data) {
675 int cpu = iter->cpu;
676 int *depth = &(per_cpu_ptr(data, cpu)->depth);
677
678 /*
679 * Comments display at + 1 to depth. This is the
680 * return from a function, we now want the comments
681 * to display at the same level of the bracket.
682 */
683 *depth = trace->depth - 1;
684 }
685
686 if (print_graph_prologue(iter, s, 0, 0))
687 return TRACE_TYPE_PARTIAL_LINE;
688
689 /* Overhead */
690 ret = print_graph_overhead(duration, s);
691 if (!ret)
692 return TRACE_TYPE_PARTIAL_LINE;
693
694 /* Duration */
695 if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) {
696 ret = print_graph_duration(duration, s);
697 if (ret == TRACE_TYPE_PARTIAL_LINE)
698 return TRACE_TYPE_PARTIAL_LINE;
699 }
700
701 /* Closing brace */
702 for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
703 ret = trace_seq_printf(s, " ");
704 if (!ret)
705 return TRACE_TYPE_PARTIAL_LINE;
706 }
707
708 ret = trace_seq_printf(s, "}\n");
709 if (!ret)
710 return TRACE_TYPE_PARTIAL_LINE;
711
712 /* Overrun */
713 if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) {
714 ret = trace_seq_printf(s, " (Overruns: %lu)\n",
715 trace->overrun);
716 if (!ret)
717 return TRACE_TYPE_PARTIAL_LINE;
718 }
719
720 ret = print_graph_irq(iter, trace->func, TRACE_GRAPH_RET, cpu, pid);
721 if (ret == TRACE_TYPE_PARTIAL_LINE)
722 return TRACE_TYPE_PARTIAL_LINE;
723
724 return TRACE_TYPE_HANDLED;
725 }
726
727 static enum print_line_t
728 print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
729 struct trace_iterator *iter)
730 {
731 unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
732 struct fgraph_data *data = iter->private;
733 struct trace_event *event;
734 int depth = 0;
735 int ret;
736 int i;
737
738 if (data)
739 depth = per_cpu_ptr(data, iter->cpu)->depth;
740
741 if (print_graph_prologue(iter, s, 0, 0))
742 return TRACE_TYPE_PARTIAL_LINE;
743
744 /* No overhead */
745 ret = print_graph_overhead(-1, s);
746 if (!ret)
747 return TRACE_TYPE_PARTIAL_LINE;
748
749 /* No time */
750 if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) {
751 ret = trace_seq_printf(s, " | ");
752 if (!ret)
753 return TRACE_TYPE_PARTIAL_LINE;
754 }
755
756 /* Indentation */
757 if (depth > 0)
758 for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++) {
759 ret = trace_seq_printf(s, " ");
760 if (!ret)
761 return TRACE_TYPE_PARTIAL_LINE;
762 }
763
764 /* The comment */
765 ret = trace_seq_printf(s, "/* ");
766 if (!ret)
767 return TRACE_TYPE_PARTIAL_LINE;
768
769 switch (iter->ent->type) {
770 case TRACE_BPRINT:
771 ret = trace_print_bprintk_msg_only(iter);
772 if (ret != TRACE_TYPE_HANDLED)
773 return ret;
774 break;
775 case TRACE_PRINT:
776 ret = trace_print_printk_msg_only(iter);
777 if (ret != TRACE_TYPE_HANDLED)
778 return ret;
779 break;
780 default:
781 event = ftrace_find_event(ent->type);
782 if (!event)
783 return TRACE_TYPE_UNHANDLED;
784
785 ret = event->trace(iter, sym_flags);
786 if (ret != TRACE_TYPE_HANDLED)
787 return ret;
788 }
789
790 /* Strip ending newline */
791 if (s->buffer[s->len - 1] == '\n') {
792 s->buffer[s->len - 1] = '\0';
793 s->len--;
794 }
795
796 ret = trace_seq_printf(s, " */\n");
797 if (!ret)
798 return TRACE_TYPE_PARTIAL_LINE;
799
800 return TRACE_TYPE_HANDLED;
801 }
802
803
804 enum print_line_t
805 print_graph_function(struct trace_iterator *iter)
806 {
807 struct trace_entry *entry = iter->ent;
808 struct trace_seq *s = &iter->seq;
809
810 switch (entry->type) {
811 case TRACE_GRAPH_ENT: {
812 struct ftrace_graph_ent_entry *field;
813 trace_assign_type(field, entry);
814 return print_graph_entry(field, s, iter);
815 }
816 case TRACE_GRAPH_RET: {
817 struct ftrace_graph_ret_entry *field;
818 trace_assign_type(field, entry);
819 return print_graph_return(&field->ret, s, entry, iter);
820 }
821 default:
822 return print_graph_comment(s, entry, iter);
823 }
824
825 return TRACE_TYPE_HANDLED;
826 }
827
828 static void print_graph_headers(struct seq_file *s)
829 {
830 /* 1st line */
831 seq_printf(s, "# ");
832 if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME)
833 seq_printf(s, " TIME ");
834 if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU)
835 seq_printf(s, "CPU");
836 if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC)
837 seq_printf(s, " TASK/PID ");
838 if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION)
839 seq_printf(s, " DURATION ");
840 seq_printf(s, " FUNCTION CALLS\n");
841
842 /* 2nd line */
843 seq_printf(s, "# ");
844 if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME)
845 seq_printf(s, " | ");
846 if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU)
847 seq_printf(s, "| ");
848 if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC)
849 seq_printf(s, " | | ");
850 if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION)
851 seq_printf(s, " | | ");
852 seq_printf(s, " | | | |\n");
853 }
854
855 static void graph_trace_open(struct trace_iterator *iter)
856 {
857 /* pid and depth on the last trace processed */
858 struct fgraph_data *data = alloc_percpu(struct fgraph_data);
859 int cpu;
860
861 if (!data)
862 pr_warning("function graph tracer: not enough memory\n");
863 else
864 for_each_possible_cpu(cpu) {
865 pid_t *pid = &(per_cpu_ptr(data, cpu)->last_pid);
866 int *depth = &(per_cpu_ptr(data, cpu)->depth);
867 *pid = -1;
868 *depth = 0;
869 }
870
871 iter->private = data;
872 }
873
874 static void graph_trace_close(struct trace_iterator *iter)
875 {
876 free_percpu(iter->private);
877 }
878
879 static struct tracer graph_trace __read_mostly = {
880 .name = "function_graph",
881 .open = graph_trace_open,
882 .close = graph_trace_close,
883 .wait_pipe = poll_wait_pipe,
884 .init = graph_trace_init,
885 .reset = graph_trace_reset,
886 .print_line = print_graph_function,
887 .print_header = print_graph_headers,
888 .flags = &tracer_flags,
889 #ifdef CONFIG_FTRACE_SELFTEST
890 .selftest = trace_selftest_startup_function_graph,
891 #endif
892 };
893
894 static __init int init_graph_trace(void)
895 {
896 return register_tracer(&graph_trace);
897 }
898
899 device_initcall(init_graph_trace);
Nao low-level kernelspace/userspace library that runs on our robots, Nao-Team HTWK