1. A semiconductor memory module, comprising:a random access memory;
a nonvolatile memory;
a buffer memory; and
a controller configured to execute a reading operation on the buffer memory in response to an activation of a control signal,
wherein the controller is further configured to execute a flush operation of storing first data, which are stored in the random access memory, in the nonvolatile memory, according to a result of the reading operation executed on the buffer memory.