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 */ 38 static 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 44 static int __init trace_sched_init(void) 45 { 46 for_each_kernel_tracepoint(fct, NULL); 47 return 0; 48 } 49 50 static void __exit trace_sched_exit(void) 51 { 52 } 53 54 module_init(trace_sched_init); 55 module_exit(trace_sched_exit); 56 57 MODULE_AUTHOR("Steven Rostedt"); 58 MODULE_DESCRIPTION("Custom scheduling events"); 59 MODULE_LICENSE("GPL"); 60