1// SPDX-License-Identifier: GPL-2.0
2/*
3 * event tracer
4 *
5 * Copyright (C) 2022 Google Inc, Steven Rostedt <rostedt@goodmis.org>
6 */
7
8#define pr_fmt(fmt) fmt
9
10#include <linux/trace_events.h>
11#include <linux/version.h>
12#include <linux/module.h>
13#include <linux/sched.h>
14
15/*
16 * Must include the event header that the custom event will attach to,
17 * from the C file, and not in the custom header file.
18 */
19#include <trace/events/sched.h>
20
21/* Declare CREATE_CUSTOM_TRACE_EVENTS before including custom header */
22#define CREATE_CUSTOM_TRACE_EVENTS
23
24#include "trace_custom_sched.h"
25
26/*
27 * As the trace events are not exported to modules, the use of
28 * for_each_kernel_tracepoint() is needed to find the trace event
29 * to attach to. The fct() function below, is a callback that
30 * will be called for every event.
31 *
32 * Helper functions are created by the TRACE_CUSTOM_EVENT() macro
33 * update the event. Those are of the form:
34 *
35 *    trace_custom_event_<event>_update()
36 *
37 * Where <event> is the event to attach.
38 */
39static void fct(struct tracepoint *tp, void *priv)
40{
41	trace_custom_event_sched_switch_update(tp);
42	trace_custom_event_sched_waking_update(tp);
43}
44
45static int __init trace_sched_init(void)
46{
47	for_each_kernel_tracepoint(fct, NULL);
48	return 0;
49}
50
51static void __exit trace_sched_exit(void)
52{
53}
54
55module_init(trace_sched_init);
56module_exit(trace_sched_exit);
57
58MODULE_AUTHOR("Steven Rostedt");
59MODULE_DESCRIPTION("Custom scheduling events");
60MODULE_LICENSE("GPL");
61