The robustness of NUMA memory management

The study of operating systems level memory management policies for nonuniform memory access time (NUMA) shared memory multiprocessors is an area of active research. Previous results have suggested that the best policy choice often depends on the application under consideration, while others have reported that the best policy depends on the particular architecture. Since both observations have merit, we explore the concept of policy tuning on an application/architecture basis.We introduce a highly tunable dynamic page placement policy for NUMA multiprocessors, and address issues related to the tuning of that policy to different architectures and applications. Experimental data acquired from our DUnX operating system running on two different NUMA multiprocessors are used to evaluate the usefulness, importance, and ease of policy tuning.Our results indicate that while varying some of the parameters can have dramatic effects on performance, it is easy to select a set of default parameter settings that result in good performance for each of our test applications on both architectures. This apparent robustness of our parameterized policy raises the possibility of machine-independent memory management for NUMA-class machines.