Coordination between memory-saving mechanisms in computers that run virtual machines

A computer, comprising:

• a physical memory;
• and
• a Central Processing Unit (CPU), which is configured to run a hypervisor that allocates physical memory pages of the physical memory to a Virtual Machine (VM), to run in the VM a guest Operating System (OS), a virtual memory and a virtual storage device, wherein the guest OS maps the allocated physical memory pages to respective virtual memory pages, retains virtual memory pages that are frequently-accessed by the VM in the virtual memory, and swaps-out virtual memory pages that are rarely-accessed by the VM to the virtual storage, to select by the hypervisor one or more of the physical memory pages allocated to the VM, and to prevent the corresponding virtual memory pages from being swapped-out by the guest OS, by marking the corresponding virtual memory pages in the guest OS as accessed thus causing the guest OS to regard the corresponding virtual memory pages as frequently-accessed.

A computer software product, the product comprising a tangible non-transitory computer-readable medium in which program instructions are stored, which instructions, when read by a Central Processing Unit (CPU) of a computer, cause the processor to run a hypervisor that allocates physical memory pages of a physical memory of the computer to a Virtual Machine (VM), to run in the VM a guest Operating System (OS), a virtual memory and a virtual storage device, wherein the guest OS maps the allocated physical memory pages to respective virtual memory pages, retains virtual memory pages that are frequently-accessed by the VM in the virtual memory, and swaps-out virtual memory pages that are rarely-accessed by the VM to the virtual storage, to select by the hypervisor one or more of the physical memory pages allocated to the VM, and to prevent the corresponding virtual memory pages from being swapped-out by the guest OS, by marking the corresponding virtual memory pages in the guest OS as accessed thus causing the guest OS to regard the corresponding virtual memory pages as frequently-accessed.