A method of operating a data processing system includes transmitting process information indicating that a first process is classified as a critical process or a non-critical process to a kernel area, wherein the process information is generated in an application area, and the application area and the kernel area define a host. When the first process is classified as a critical process based on the process information, a first fastpath write signal is provided, using the kernel area, to a memory system to perform a fastpath write operation of first data for performing the first process. When the first process is classified as a non-critical process, a first slowpath write signal is provided to the memory system to perform a slowpath write operation of the first data. The fastpath write operation has a higher write speed than the slowpath write operation.