An Adaptive Task-Core Ratio Load Balancing Strategy for Multi-core Processors

Abstract

With the proliferation of multi-core processors in servers, desktops, game consoles, mobile phones and a magnitude of other embedded devices; the need to ensure effective utilization of the processing cores becomes essential. This calls for research and development emphasis for a well engineered operating systems load balancer for these multi-core processors. In this paper, an adaptive load balancing strategy is presented. The adaptive load balancer will trigger tasks migration based on the tasks to processing core ratio, as well as when a processing core becomes idle. In our work, we utilize LinSched, a Linux operating system scheduler simulator, to analyze the number of task migrations. The Linux operating system is representative of the whole spectrum of computing as it is used in supercomputers, servers, desktops, mobile phones and embedded devices. Results from the simulation show that unnecessary task migrations were eliminated whilst maintaining the load balancing function effectively, as compared to the default strategy employed by the Linux operating system. The overheads introduced by the adaptive load balancer were measure through implementing it in a Linux kernel and measurements were made using the hackbench scalability test. The implementation proves to have negligible effect on the scalability and we can conclude that it does not introduce overheads. From our research, it shows that the adaptive load balancer provides a scalable solution for a lower and more consistent triggering of task migrations.