Preferably, after the earliest region is determined, the control portion updates at appropriate times the history information stored in the determined earliest region in accordance with progress of {HEAD ~ the constant procedure} before end or {TAIL ~ interruption} of the constant procedure in the input/output processing 
Preferably , after the earliest region is determined , the control portion updates at appropriate times the history information stored in the determined earliest region in accordance with progress of { HEAD ~ the constant procedure } before end or { TAIL ~ interruption } of the constant procedure in the input / output processing
OTH OTH OTH OTH OTH OTH OTH 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 REL OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH