ftrace: introduce tracing_reset_online_cpus() helper
[linux-2.6] / kernel / trace / trace_functions.c
1 /*
2  * ring buffer based function tracer
3  *
4  * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
5  * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
6  *
7  * Based on code from the latency_tracer, that is:
8  *
9  *  Copyright (C) 2004-2006 Ingo Molnar
10  *  Copyright (C) 2004 William Lee Irwin III
11  */
12 #include <linux/debugfs.h>
13 #include <linux/uaccess.h>
14 #include <linux/ftrace.h>
15 #include <linux/fs.h>
16
17 #include "trace.h"
18
19 static void start_function_trace(struct trace_array *tr)
20 {
21         tr->cpu = get_cpu();
22         tracing_reset_online_cpus(tr);
23         put_cpu();
24
25         tracing_start_cmdline_record();
26         tracing_start_function_trace();
27 }
28
29 static void stop_function_trace(struct trace_array *tr)
30 {
31         tracing_stop_function_trace();
32         tracing_stop_cmdline_record();
33 }
34
35 static int function_trace_init(struct trace_array *tr)
36 {
37         start_function_trace(tr);
38         return 0;
39 }
40
41 static void function_trace_reset(struct trace_array *tr)
42 {
43         stop_function_trace(tr);
44 }
45
46 static void function_trace_start(struct trace_array *tr)
47 {
48         tracing_reset_online_cpus(tr);
49 }
50
51 static struct tracer function_trace __read_mostly =
52 {
53         .name        = "function",
54         .init        = function_trace_init,
55         .reset       = function_trace_reset,
56         .start       = function_trace_start,
57 #ifdef CONFIG_FTRACE_SELFTEST
58         .selftest    = trace_selftest_startup_function,
59 #endif
60 };
61
62 static __init int init_function_trace(void)
63 {
64         return register_tracer(&function_trace);
65 }
66
67 device_initcall(init_function_trace);