A memory management method in a virtualized computing environment is provided, in which a hypervisor implements at least a virtual machine (VM) over a host machine, wherein a guest operating system (OS) is executed over the VM and an application supporting memory management capabilities is executed over the guest OS. The method comprises invoking a first memory manager (java balloon) implemented by the application to deallocate memory allocated to the application for use by the hypervisor, in response to a request submitted by the hypervisor; and invoking a second memory manager (guest balloon) implemented over the guest operating system to deallocate memory allocated to the guest OS, in response to a request submitted by the hypervisor.