{TAIL ~ Each node} of the queue holds a reference to a task that may be concurrently performed by multiple thread execution units, but each on {HEAD ~ a different subset} of data 
{ TAIL ~ Each node } of the queue holds a reference to a task that may be concurrently performed by multiple thread execution units , but each on { HEAD ~ a different subset } of data
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 OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH