File I/O request

This line identifies the file request macro that caused a wait for I/O completion.

Under Heading This is Displayed
Name The DASD I/O macro function (GET, PUT, CHECK, etc.) that caused the wait.
Description The address of the macro (return address) in CSECT+offset format.
Percent of Time The percentage of the measurement interval time the step was waiting for completion of I/O for the indicated macro.