1. An apparatus, comprising: at least one processor for executing a processing of an application program; a main memory, comprising: an in-memory cache structure for normally temporarily storing data produced in said processing; and an in-memory storage structure outside said in-memory cache structure, for by-passing said in-memory cache structure for temporarily storing data under a predetermined condition; a sensor for detecting an amount of usage of said in-memory cache structure used to store data during said processing; and a controller for, upon a detection by said sensor that said amount of usage exceeds said predetermined threshold, controlling said processing so that said data produced in said processing is stored in said in-memory storage structure rather than in said in-memory cache structure.