Each processor has its own cache directory and {TAIL ~ image directory} that duplicate {HEAD ~ each other non} atomically 
Each processor has its own cache directory and { TAIL ~ image directory } that duplicate { HEAD ~ each other non } atomically
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH