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/*
* ring buffer based function tracer
*
* Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
* Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
*
* Based on code from the latency_tracer, that is:
*
* Copyright (C) 2004-2006 Ingo Molnar
* Copyright (C) 2004 William Lee Irwin III
*/
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/ftrace.h>
#include <linux/fs.h>
#include "trace.h"
static void function_reset(struct trace_array *tr)
{
int cpu;
tr->time_start = ftrace_now(tr->cpu);
for_each_online_cpu(cpu)
tracing_reset(tr->data[cpu]);
}
static void start_function_trace(struct trace_array *tr)
{
function_reset(tr);
atomic_inc(&trace_record_cmdline_enabled);
tracing_start_function_trace();
}
static void stop_function_trace(struct trace_array *tr)
{
tracing_stop_function_trace();
atomic_dec(&trace_record_cmdline_enabled);
}
static void function_trace_init(struct trace_array *tr)
{
if (tr->ctrl)
start_function_trace(tr);
}
static void function_trace_reset(struct trace_array *tr)
{
if (tr->ctrl)
stop_function_trace(tr);
}
static void function_trace_ctrl_update(struct trace_array *tr)
{
if (tr->ctrl)
start_function_trace(tr);
else
stop_function_trace(tr);
}
static struct tracer function_trace __read_mostly =
{
.name = "ftrace",
.init = function_trace_init,
.reset = function_trace_reset,
.ctrl_update = function_trace_ctrl_update,
#ifdef CONFIG_FTRACE_SELFTEST
.selftest = trace_selftest_startup_function,
#endif
};
static __init int init_function_trace(void)
{
return register_tracer(&function_trace);
}
device_initcall(init_function_trace);
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