If the queue structure indicates that {HEAD ~ the parent scheduler} is at {TAIL ~ a higher level} , the queue fetch logic ignores the absent intermediate scheduler levels, for example during scheduling, enqueue and dequeue operations 
If the queue structure indicates that { HEAD ~ the parent scheduler } is at { TAIL ~ a higher level } , the queue fetch logic ignores the absent intermediate scheduler levels , for example during scheduling , enqueue and dequeue operations
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH