Dynamic partitioned scheduling of real-time tasks on ARM big.LITTLE architectures

This paper presents Big-LITTLE Constant Bandwidth Server (BL-CBS), a dynamic partitioning approach to schedule real-time task sets in an energy-efficient way on multi-core platforms based on the ARM big.LITTLE architecture. BL-CBS is designed as an on-line and adaptive scheduler, based on a push/pull architecture that is suitable to be incorporated in the current SCHED_DEADLINE code base in the Linux kernel. It employs a greedy heuristic to dynamically partition the real-time tasks among the big and LITTLE cores aiming to minimize the energy consumption and the migrations imposed on the running tasks. The new approach is validated through the open-source RT-Sim simulator, which has been extended integrating an energy model of the ODROID-XU3 board, fitting tightly the power consumption profiles for the big and LITTLE cores of the board. An extensive set of simulations have been run with randomly generated real-time task sets, leading to promising results.