Embodiments of the present invention provide a method, system and computer program product for dynamic main memory reconfiguration in virtual memory management. In an embodiment of the invention, a method for dynamic main memory reconfiguration in virtual memory management can include receiving a memory access directive in a host computer, determining a low free space condition in a memory allocation to satisfy the memory access directive, augmenting the memory allocation with a mapping to additional memory in the host computer in lieu of page swapping in response to the low free space condition, and satisfying the memory access directive. Additionally, the method can include determining an excess free space condition in the memory allocation and removing from the memory allocation a selection of allocated memory in the host computer.