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 */ 39 static 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 45 static int __init trace_sched_init(void) 46 { 47 for_each_kernel_tracepoint(fct, NULL); 48 return 0; 49 } 50 51 static void __exit trace_sched_exit(void) 52 { 53 } 54 55 module_init(trace_sched_init); 56 module_exit(trace_sched_exit); 57 58 MODULE_AUTHOR("Steven Rostedt"); 59 MODULE_DESCRIPTION("Custom scheduling events"); 60 MODULE_LICENSE("GPL"); 61