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