Abstract: One embodiment of the present invention provides a system for deleting objects from a memory in a computing device, wherein the memory includes both a volatile memory and a non-volatile memory that is writeable. During operation, the system receives a request to perform an object deletion operation, which locates and deletes unused objects from the memory. In response to this request, the system performs the object deletion operation by first performing a marking operation that marks objects that are reachable in the non-volatile memory. This marking operation does not directly mark the objects in the non-volatile memory, but instead marks data values in the volatile memory that are associated with the objects. In this way, unnecessary write operations to non-volatile memory are avoided. Next, the system performs a sweep operation that deletes unmarked objects from the non-volatile memory.