samples/trace_events/trace-events-sample.c

   1 #include <linux/module.h>
   2 #include <linux/kthread.h>
   3
   4 /*
   5  * Any file that uses trace points, must include the header.
   6  * But only one file, must include the header by defining
   7  * CREATE_TRACE_POINTS first.  This will make the C code that
   8  * creates the handles for the trace points.
   9  */
  10 #define CREATE_TRACE_POINTS
  11 #include "trace-events-sample.h"
  12
  13
  14 static void simple_thread_func(int cnt)
  15 {
  16         set_current_state(TASK_INTERRUPTIBLE);
  17         schedule_timeout(HZ);
  18         trace_foo_bar("hello", cnt);
  19
  20         if (!(cnt % 10))
  21                 /* It is really important that I say "hi!" */
  22                 printk(KERN_EMERG "hi!\n");
  23 }
  24
  25 static int simple_thread(void *arg)
  26 {
  27         int cnt = 0;
  28
  29         while (!kthread_should_stop())
  30                 simple_thread_func(cnt++);
  31
  32         return 0;
  33 }
  34
  35 static struct task_struct *simple_tsk;
  36
  37 static int __init trace_event_init(void)
  38 {
  39         simple_tsk = kthread_run(simple_thread, NULL, "event-sample");
  40         if (IS_ERR(simple_tsk))
  41                 return -1;
  42
  43         return 0;
  44 }
  45
  46 static void __exit trace_event_exit(void)
  47 {
  48         kthread_stop(simple_tsk);
  49 }
  50
  51 module_init(trace_event_init);
  52 module_exit(trace_event_exit);
  53
  54 MODULE_AUTHOR("Steven Rostedt");
  55 MODULE_DESCRIPTION("trace-events-sample");
  56 MODULE_LICENSE("GPL");