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