Operating System Mechanisms for Many-Core Systems

Overwhelming heat and clocking considerations have led to the accelerating rise of multicore processors. The number of cores per chip is expected to increase rapidly in coming years. In fact, chips with 100 cores and prototypes with 128 cores are already available. As the number of cores increases, the scalability of the operating system(s) will become a major bottleneck, particularly for embedded real-time systems where both performance and predictability are critical. We propose a suite of real-time operating system extensions that will (a) significantly enhance their scalability by minimizing inter-core OS data sharing, (b) explicitly limit migration of real-time tasks across cores, (c) automatically split a small number of selected tasks across two proximate cores for maximizing schedulable utilization, (d) perform admission control and resource reservation to offer both spatial and temporal isolation across applications. A functioning prototype on a real-time operating system will showcase some of these capabilities.