Blockers are responsible for blocking new request for a cache line until {HEAD ~ an outstanding request} for {TAIL ~ that cache line} has been serviced 
for
Blockers are responsible for blocking new request for a cache line until { HEAD ~ an outstanding request } for { TAIL ~ that cache line } has been serviced
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH