-format tracefile. It has four commandline parameters, the first is tracefile
-name, the second is process file, the third is a number (the number of cpu in the machine),
+format tracefile. It has several commandline parameters, the first is process file
+name, the second is a number (the number of cpu in the machine), the third is
+the first tracefile name(corresponding to the first cpu), the fourth is the
+second tracefile name(corresponding to the second cpu), the fifth is ...,