Event measuring apparatus and method, computer readable record medium in which an event measuring program is stored, and computer system

摘要

An apparatus which can collect information for a long time or collect information on an entire memory space with a small hardware physical quantity while avoiding unnecessary overhead. The apparatus comprises a counting unit for counting the number of events having occurred in a processor or a computer system, a retaining unit for retaining a count value obtained by the counting unit, and a control unit for controlling writing of a count value into the retaining unit, wherein the control unit controls the writing so as to write a new count value obtained by the counting unit in said retaining unit while leaving a count value of a high degree of significance in the retaining unit. The apparatus is used to measure the number of events having occurred in the processor when the performance of the processor or the a computer system is measured or tuned.