Improved scheduler for multi-core many-core systems

Abstract

Over the years, presence of heterogeneous system has dominated the area of concurrent job execution. Heterogeneous system is the natural choice as it can be designed with the legacy system. Scheduling, on such systems, is an important activity as it affects the job execution characteristic. Heterogeneity introduces many challenges for the efficient job execution. Heterogeneity in core architecture introduces the possibility of heterogeneous memory architecture in many/multi core heterogeneous system. This makes it often impossible to determine for the same instruction if a high frequency core has low or high memory latency in comparison to the low frequency core and vice-versa. The work proposes an improved scheduler for such systems in which both core and memory are heterogeneous. It defines average effective time ($\hbox {AE}_\mathrm{t}$) as the base parameter for this purpose. Priorities of each thread (workload) and the core are dynamically generated using $\hbox {AE}_\mathrm{t}$ for effective mapping. Experimental results, on the benchmark data, reveal that the proposed scheduler performs much better in terms of cores utilization, speedup and efficiency in comparison to other similar models.