Dynamic and Application-Driven I-Cache Partitioning for Low-Power Embedded Multitasking

The abundance of wireless connectivity and the increased workload complexity have further underlined the importance of energy efficiency for modern embedded applications. The cache memory is a major contributor to the system power consumption, and as such is a primary target for energy reduction techniques. Recent advances in configurable cache architectures have enabled an entirely new set of approaches for application-driven energy- and cost-efficient cache resource utilization. We propose a run-time cross-layer specialization methodology, which leverages configurable cache architectures to achieve an energy- and performance-conscious adaptive mapping of instruction cache resources to tasks in dynamic multitasking workloads. Sizable leakage and dynamic power reductions are achieved with only a negligible and system-controlled performance impact. The methodology assumes no prior information regarding the dynamics and the structure of the workload. As the proposed dynamic cache partitioning alleviates the detrimental effects of cache interference, performance is maintained very close to the baseline case, while achieving 50%-70% reductions in dynamic and static leakage power for the on-chip instruction cache.