1. A memory management method of managing a memory area of a memory used by a processor, the processor being connected to the memory that stores data accessed while a task is being executed, the memory management method comprising the steps of: dividing the memory area of the memory into a plurality of first size blocks; creating a plurality of second size blocks by further dividing at least one of the plurality of the first size blocks into a plurality of second size blocks each of which is an integer fraction of the first size blocks so that the second size blocks are assigned to a continuous area and the memory includes both of at least one of the plurality of first size blocks and the plurality of second size blocks; selecting one of the first size blocks and the second size blocks matching a size of the data accessed while the task is being executed; and storing the data accessed while the task is being executed in the selected block.