root/kernel/trace/trace_functions.c

DEFINITIONS

1. function_reset
2. start_function_trace
3. stop_function_trace
4. function_trace_init
5. function_trace_reset
6. function_trace_ctrl_update
7. init_function_trace

/*
 * 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)
{
        tr->cpu = get_cpu();
        function_reset(tr);
        put_cpu();

        tracing_start_cmdline_record();
        tracing_start_function_trace();
}

static void stop_function_trace(struct trace_array *tr)
{
        tracing_stop_function_trace();
        tracing_stop_cmdline_record();
}

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);