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linux/kernel/trace/trace_functions_graph.c
Frederic Weisbecker b91facc367 tracing/function-graph-tracer: handle the leaf functions from trace_pipe 
When one cats the trace file, the leaf functions are printed without brackets:

 function();

whereas in the trace_pipe file we'll see the following:

 function() {
 }

This is because the ring_buffer handling is not the same between those two files.
On the trace file, when an entry is printed, the iterator advanced and then we can
check the next entry.

There is no iterator with trace_pipe, the current entry to print has been peeked
and not consumed. So checking the next entry will still return the current one while
we don't consume it.

This patch introduces a new value for the output callbacks to ask the tracing
core to not consume the current entry after printing it.

We need it because we will have to consume the current entry ourself to check
the next one.

Now the trace_pipe is able to handle well the leaf functions.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-09 12:37:27 +01:00

776 lines
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/*
*
* Function graph tracer.
* Copyright (c) 2008-2009 Frederic Weisbecker <fweisbec@gmail.com>
* Mostly borrowed from function tracer which
* is Copyright (c) Steven Rostedt <srostedt@redhat.com>
*
*/
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/ftrace.h>
#include <linux/fs.h>
#include "trace.h"
#include "trace_output.h"
#define TRACE_GRAPH_INDENT 2
/* Flag options */
#define TRACE_GRAPH_PRINT_OVERRUN 0x1
#define TRACE_GRAPH_PRINT_CPU 0x2
#define TRACE_GRAPH_PRINT_OVERHEAD 0x4
#define TRACE_GRAPH_PRINT_PROC 0x8
#define TRACE_GRAPH_PRINT_DURATION 0x10
#define TRACE_GRAPH_PRINT_ABS_TIME 0X20
static struct tracer_opt trace_opts[] = {
/* Display overruns? (for self-debug purpose) */
{ TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) },
/* Display CPU ? */
{ TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },
/* Display Overhead ? */
{ TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },
/* Display proc name/pid */
{ TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) },
/* Display duration of execution */
{ TRACER_OPT(funcgraph-duration, TRACE_GRAPH_PRINT_DURATION) },
/* Display absolute time of an entry */
{ TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) },
{ } /* Empty entry */
};
static struct tracer_flags tracer_flags = {
/* Don't display overruns and proc by default */
.val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD |
TRACE_GRAPH_PRINT_DURATION,
.opts = trace_opts
};
/* pid on the last trace processed */
static int graph_trace_init(struct trace_array *tr)
{
int ret = register_ftrace_graph(&trace_graph_return,
&trace_graph_entry);
if (ret)
return ret;
tracing_start_cmdline_record();
return 0;
}
static void graph_trace_reset(struct trace_array *tr)
{
tracing_stop_cmdline_record();
unregister_ftrace_graph();
}
static inline int log10_cpu(int nb)
{
if (nb / 100)
return 3;
if (nb / 10)
return 2;
return 1;
}
static enum print_line_t
print_graph_cpu(struct trace_seq *s, int cpu)
{
int i;
int ret;
int log10_this = log10_cpu(cpu);
int log10_all = log10_cpu(cpumask_weight(cpu_online_mask));
/*
* Start with a space character - to make it stand out
* to the right a bit when trace output is pasted into
* email:
*/
ret = trace_seq_printf(s, " ");
/*
* Tricky - we space the CPU field according to the max
* number of online CPUs. On a 2-cpu system it would take
* a maximum of 1 digit - on a 128 cpu system it would
* take up to 3 digits:
*/
for (i = 0; i < log10_all - log10_this; i++) {
ret = trace_seq_printf(s, " ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
ret = trace_seq_printf(s, "%d) ", cpu);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
return TRACE_TYPE_HANDLED;
}
#define TRACE_GRAPH_PROCINFO_LENGTH 14
static enum print_line_t
print_graph_proc(struct trace_seq *s, pid_t pid)
{
int i;
int ret;
int len;
char comm[8];
int spaces = 0;
/* sign + log10(MAX_INT) + '\0' */
char pid_str[11];
strncpy(comm, trace_find_cmdline(pid), 7);
comm[7] = '\0';
sprintf(pid_str, "%d", pid);
/* 1 stands for the "-" character */
len = strlen(comm) + strlen(pid_str) + 1;
if (len < TRACE_GRAPH_PROCINFO_LENGTH)
spaces = TRACE_GRAPH_PROCINFO_LENGTH - len;
/* First spaces to align center */
for (i = 0; i < spaces / 2; i++) {
ret = trace_seq_printf(s, " ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
ret = trace_seq_printf(s, "%s-%s", comm, pid_str);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* Last spaces to align center */
for (i = 0; i < spaces - (spaces / 2); i++) {
ret = trace_seq_printf(s, " ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
return TRACE_TYPE_HANDLED;
}
/* If the pid changed since the last trace, output this event */
static enum print_line_t
verif_pid(struct trace_seq *s, pid_t pid, int cpu, pid_t *last_pids_cpu)
{
pid_t prev_pid;
pid_t *last_pid;
int ret;
if (!last_pids_cpu)
return TRACE_TYPE_HANDLED;
last_pid = per_cpu_ptr(last_pids_cpu, cpu);
if (*last_pid == pid)
return TRACE_TYPE_HANDLED;
prev_pid = *last_pid;
*last_pid = pid;
if (prev_pid == -1)
return TRACE_TYPE_HANDLED;
/*
* Context-switch trace line:
------------------------------------------
| 1) migration/0--1 => sshd-1755
------------------------------------------
*/
ret = trace_seq_printf(s,
" ------------------------------------------\n");
if (!ret)
TRACE_TYPE_PARTIAL_LINE;
ret = print_graph_cpu(s, cpu);
if (ret == TRACE_TYPE_PARTIAL_LINE)
TRACE_TYPE_PARTIAL_LINE;
ret = print_graph_proc(s, prev_pid);
if (ret == TRACE_TYPE_PARTIAL_LINE)
TRACE_TYPE_PARTIAL_LINE;
ret = trace_seq_printf(s, " => ");
if (!ret)
TRACE_TYPE_PARTIAL_LINE;
ret = print_graph_proc(s, pid);
if (ret == TRACE_TYPE_PARTIAL_LINE)
TRACE_TYPE_PARTIAL_LINE;
ret = trace_seq_printf(s,
"\n ------------------------------------------\n\n");
if (!ret)
TRACE_TYPE_PARTIAL_LINE;
return ret;
}
static struct ftrace_graph_ret_entry *
get_return_for_leaf(struct trace_iterator *iter,
struct ftrace_graph_ent_entry *curr)
{
struct ring_buffer_iter *ring_iter;
struct ring_buffer_event *event;
struct ftrace_graph_ret_entry *next;
ring_iter = iter->buffer_iter[iter->cpu];
/* First peek to compare current entry and the next one */
if (ring_iter)
event = ring_buffer_iter_peek(ring_iter, NULL);
else {
/* We need to consume the current entry to see the next one */
ring_buffer_consume(iter->tr->buffer, iter->cpu, NULL);
event = ring_buffer_peek(iter->tr->buffer, iter->cpu,
NULL);
}
if (!event)
return NULL;
next = ring_buffer_event_data(event);
if (next->ent.type != TRACE_GRAPH_RET)
return NULL;
if (curr->ent.pid != next->ent.pid ||
curr->graph_ent.func != next->ret.func)
return NULL;
/* this is a leaf, now advance the iterator */
if (ring_iter)
ring_buffer_read(ring_iter, NULL);
return next;
}
/* Signal a overhead of time execution to the output */
static int
print_graph_overhead(unsigned long long duration, struct trace_seq *s)
{
/* If duration disappear, we don't need anything */
if (!(tracer_flags.val & TRACE_GRAPH_PRINT_DURATION))
return 1;
/* Non nested entry or return */
if (duration == -1)
return trace_seq_printf(s, " ");
if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
/* Duration exceeded 100 msecs */
if (duration > 100000ULL)
return trace_seq_printf(s, "! ");
/* Duration exceeded 10 msecs */
if (duration > 10000ULL)
return trace_seq_printf(s, "+ ");
}
return trace_seq_printf(s, " ");
}
static enum print_line_t
print_graph_irq(struct trace_seq *s, unsigned long addr,
enum trace_type type, int cpu, pid_t pid)
{
int ret;
if (addr < (unsigned long)__irqentry_text_start ||
addr >= (unsigned long)__irqentry_text_end)
return TRACE_TYPE_UNHANDLED;
/* Cpu */
if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
ret = print_graph_cpu(s, cpu);
if (ret == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
}
/* Proc */
if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
ret = print_graph_proc(s, pid);
if (ret == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
ret = trace_seq_printf(s, " | ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
/* No overhead */
ret = print_graph_overhead(-1, s);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
if (type == TRACE_GRAPH_ENT)
ret = trace_seq_printf(s, "==========>");
else
ret = trace_seq_printf(s, "<==========");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* Don't close the duration column if haven't one */
if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION)
trace_seq_printf(s, " |");
ret = trace_seq_printf(s, "\n");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
return TRACE_TYPE_HANDLED;
}
static enum print_line_t
print_graph_duration(unsigned long long duration, struct trace_seq *s)
{
unsigned long nsecs_rem = do_div(duration, 1000);
/* log10(ULONG_MAX) + '\0' */
char msecs_str[21];
char nsecs_str[5];
int ret, len;
int i;
sprintf(msecs_str, "%lu", (unsigned long) duration);
/* Print msecs */
ret = trace_seq_printf(s, "%s", msecs_str);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
len = strlen(msecs_str);
/* Print nsecs (we don't want to exceed 7 numbers) */
if (len < 7) {
snprintf(nsecs_str, 8 - len, "%03lu", nsecs_rem);
ret = trace_seq_printf(s, ".%s", nsecs_str);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
len += strlen(nsecs_str);
}
ret = trace_seq_printf(s, " us ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* Print remaining spaces to fit the row's width */
for (i = len; i < 7; i++) {
ret = trace_seq_printf(s, " ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
ret = trace_seq_printf(s, "| ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
return TRACE_TYPE_HANDLED;
}
static int print_graph_abs_time(u64 t, struct trace_seq *s)
{
unsigned long usecs_rem;
usecs_rem = do_div(t, 1000000000);
usecs_rem /= 1000;
return trace_seq_printf(s, "%5lu.%06lu | ",
(unsigned long)t, usecs_rem);
}
/* Case of a leaf function on its call entry */
static enum print_line_t
print_graph_entry_leaf(struct trace_iterator *iter,
struct ftrace_graph_ent_entry *entry,
struct ftrace_graph_ret_entry *ret_entry, struct trace_seq *s)
{
struct ftrace_graph_ret *graph_ret;
struct ftrace_graph_ent *call;
unsigned long long duration;
int ret;
int i;
graph_ret = &ret_entry->ret;
call = &entry->graph_ent;
duration = graph_ret->rettime - graph_ret->calltime;
/* Overhead */
ret = print_graph_overhead(duration, s);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* Duration */
if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) {
ret = print_graph_duration(duration, s);
if (ret == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
}
/* Function */
for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
ret = trace_seq_printf(s, " ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
ret = seq_print_ip_sym(s, call->func, 0);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
ret = trace_seq_printf(s, "();\n");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
return TRACE_TYPE_HANDLED;
}
static enum print_line_t
print_graph_entry_nested(struct ftrace_graph_ent_entry *entry,
struct trace_seq *s, pid_t pid, int cpu)
{
int i;
int ret;
struct ftrace_graph_ent *call = &entry->graph_ent;
/* No overhead */
ret = print_graph_overhead(-1, s);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* No time */
if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) {
ret = trace_seq_printf(s, " | ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
/* Function */
for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
ret = trace_seq_printf(s, " ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
ret = seq_print_ip_sym(s, call->func, 0);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
ret = trace_seq_printf(s, "() {\n");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/*
* we already consumed the current entry to check the next one
* and see if this is a leaf.
*/
return TRACE_TYPE_NO_CONSUME;
}
static enum print_line_t
print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
struct trace_iterator *iter)
{
int ret;
int cpu = iter->cpu;
pid_t *last_entry = iter->private;
struct trace_entry *ent = iter->ent;
struct ftrace_graph_ent *call = &field->graph_ent;
struct ftrace_graph_ret_entry *leaf_ret;
/* Pid */
if (verif_pid(s, ent->pid, cpu, last_entry) == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
/* Interrupt */
ret = print_graph_irq(s, call->func, TRACE_GRAPH_ENT, cpu, ent->pid);
if (ret == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
/* Absolute time */
if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME) {
ret = print_graph_abs_time(iter->ts, s);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
/* Cpu */
if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
ret = print_graph_cpu(s, cpu);
if (ret == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
}
/* Proc */
if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
ret = print_graph_proc(s, ent->pid);
if (ret == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
ret = trace_seq_printf(s, " | ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
leaf_ret = get_return_for_leaf(iter, field);
if (leaf_ret)
return print_graph_entry_leaf(iter, field, leaf_ret, s);
else
return print_graph_entry_nested(field, s, iter->ent->pid, cpu);
}
static enum print_line_t
print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
struct trace_entry *ent, struct trace_iterator *iter)
{
int i;
int ret;
int cpu = iter->cpu;
pid_t *last_pid = iter->private;
unsigned long long duration = trace->rettime - trace->calltime;
/* Pid */
if (verif_pid(s, ent->pid, cpu, last_pid) == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
/* Absolute time */
if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME) {
ret = print_graph_abs_time(iter->ts, s);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
/* Cpu */
if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
ret = print_graph_cpu(s, cpu);
if (ret == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
}
/* Proc */
if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
ret = print_graph_proc(s, ent->pid);
if (ret == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
ret = trace_seq_printf(s, " | ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
/* Overhead */
ret = print_graph_overhead(duration, s);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* Duration */
if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) {
ret = print_graph_duration(duration, s);
if (ret == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
}
/* Closing brace */
for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
ret = trace_seq_printf(s, " ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
ret = trace_seq_printf(s, "}\n");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* Overrun */
if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) {
ret = trace_seq_printf(s, " (Overruns: %lu)\n",
trace->overrun);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
ret = print_graph_irq(s, trace->func, TRACE_GRAPH_RET, cpu, ent->pid);
if (ret == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
return TRACE_TYPE_HANDLED;
}
static enum print_line_t
print_graph_comment(struct print_entry *trace, struct trace_seq *s,
struct trace_entry *ent, struct trace_iterator *iter)
{
int i;
int ret;
int cpu = iter->cpu;
pid_t *last_pid = iter->private;
/* Absolute time */
if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME) {
ret = print_graph_abs_time(iter->ts, s);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
/* Pid */
if (verif_pid(s, ent->pid, cpu, last_pid) == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
/* Cpu */
if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
ret = print_graph_cpu(s, cpu);
if (ret == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
}
/* Proc */
if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
ret = print_graph_proc(s, ent->pid);
if (ret == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
ret = trace_seq_printf(s, " | ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
/* No overhead */
ret = print_graph_overhead(-1, s);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* No time */
if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) {
ret = trace_seq_printf(s, " | ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
/* Indentation */
if (trace->depth > 0)
for (i = 0; i < (trace->depth + 1) * TRACE_GRAPH_INDENT; i++) {
ret = trace_seq_printf(s, " ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
/* The comment */
ret = trace_seq_printf(s, "/* %s", trace->buf);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* Strip ending newline */
if (s->buffer[s->len - 1] == '\n') {
s->buffer[s->len - 1] = '\0';
s->len--;
}
ret = trace_seq_printf(s, " */\n");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
return TRACE_TYPE_HANDLED;
}
enum print_line_t
print_graph_function(struct trace_iterator *iter)
{
struct trace_seq *s = &iter->seq;
struct trace_entry *entry = iter->ent;
switch (entry->type) {
case TRACE_GRAPH_ENT: {
struct ftrace_graph_ent_entry *field;
trace_assign_type(field, entry);
return print_graph_entry(field, s, iter);
}
case TRACE_GRAPH_RET: {
struct ftrace_graph_ret_entry *field;
trace_assign_type(field, entry);
return print_graph_return(&field->ret, s, entry, iter);
}
case TRACE_PRINT: {
struct print_entry *field;
trace_assign_type(field, entry);
return print_graph_comment(field, s, entry, iter);
}
default:
return TRACE_TYPE_UNHANDLED;
}
}
static void print_graph_headers(struct seq_file *s)
{
/* 1st line */
seq_printf(s, "# ");
if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME)
seq_printf(s, " TIME ");
if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU)
seq_printf(s, "CPU");
if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC)
seq_printf(s, " TASK/PID ");
if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION)
seq_printf(s, " DURATION ");
seq_printf(s, " FUNCTION CALLS\n");
/* 2nd line */
seq_printf(s, "# ");
if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME)
seq_printf(s, " | ");
if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU)
seq_printf(s, "| ");
if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC)
seq_printf(s, " | | ");
if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION)
seq_printf(s, " | | ");
seq_printf(s, " | | | |\n");
}
static void graph_trace_open(struct trace_iterator *iter)
{
/* pid on the last trace processed */
pid_t *last_pid = alloc_percpu(pid_t);
int cpu;
if (!last_pid)
pr_warning("function graph tracer: not enough memory\n");
else
for_each_possible_cpu(cpu) {
pid_t *pid = per_cpu_ptr(last_pid, cpu);
*pid = -1;
}
iter->private = last_pid;
}
static void graph_trace_close(struct trace_iterator *iter)
{
percpu_free(iter->private);
}
static struct tracer graph_trace __read_mostly = {
.name = "function_graph",
.open = graph_trace_open,
.close = graph_trace_close,
.init = graph_trace_init,
.reset = graph_trace_reset,
.print_line = print_graph_function,
.print_header = print_graph_headers,
.flags = &tracer_flags,
#ifdef CONFIG_FTRACE_SELFTEST
.selftest = trace_selftest_startup_function_graph,
#endif
};
static __init int init_graph_trace(void)
{
return register_tracer(&graph_trace);
}
device_initcall(init_graph_trace);
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