In one embodiment, a virtual machine manager may use dynamic memory balancing and greedy ballooning to improve guest memory performance. A memory 130 may have a system memory page set with a system memory page set size associated with the virtual machine to support a guest memory page set of the virtual machine with a guest memory page set size. A processor 120 may instruct the virtual machine to execute a reduction of the guest memory page set size. The processor 120 may maintain the system memory page set size during the reduction.