An Evaluation of the Linux Virtual Memory Manager to Determine Suitability for Runtime Variation of Memory

Systems that support virtual memory virtualize the available physical memory such that the applications running on them operate under the assumption that these systems have a larger amount of memory available than is actually present. The memory managers of these systems manage the virtual and the physical address spaces and are responsible for converting the virtual addresses used by the applications to the physical addresses used by the hardware. The memory managers assume that the amount of physical memory is constant and does not change during their period of operation. Some operating scenarios however, such as the power conservation mechanisms and virtual machine monitors, require the ability to vary the physical memory available at runtime, thereby making invalid the assumptions made by these memory managers. In this work we evaluate the suitability of the Linux Memory Manager, which assumes that the available physical memory is constant, for the purposes of varying the memory at run time. We have implemented an infrastructure over the Linux 2.6.11 kernel that enables the user to vary the physical memory available to the system. The availabl