1. A method of extending a virtual address space of a process executed in an operating system where the virtual address space includes a plurality of virtual address ranges, the method comprising: selecting a virtual address range to be extended from among the plurality of virtual address ranges included in the virtual address space corresponding to the process and selecting a number of a plurality of extended virtual address ranges; to be generated with respect to the selected virtual address range; extending and thereby setting the virtual address space to a multi-virtual address space based on the selected virtual address range and the selected number of the plurality of extended virtual address ranges; and providing the multi-virtual address space to the process.