title: Transition from Wait queue to run queue
body: <p>When a process calls wait_event_interruptible the process goes to sleep(assuming the condition is satisfied and there are no pending signals) the scheduler removes the process from the run queue to the wait queue.
  When there is wake_up call how exactly and who removes the process from wait queue and keeps it in the run queue?</p>
  
  <p>Thaks</p>