We are creating timer through timer_create API using 
       clock_id as CLOCK_REALTIME, 
       event type as SIGEV_THREAD,
       and have registered some function for notification
We start this periodic timer with timeout value of 1 sec.
We have observed that most of times our function registered for notification is called after 1 sec. But sometimes our 
function registered for notification is not called for several seconds (like 8-10 seconds).

What could be the reasons for this ?