1. A multi-core processor system comprising: a plurality of cores configured to execute a plurality of tasks, respectively; and a plurality of caches configured to store data accessed by the cores when the cores execute the tasks, respectively, wherein a first core of the cores stores, when a priority of a task assigned to any one of the cores is greater than or equal to a given value, the data into a cache corresponding to the core before the core to which the task is assigned executes the task; and wherein the first core assigns, among tasks each of which has a priority greater than or equal to the given value, tasks that access identical data to an identical core of the cores.