Authors : Varahagiri Venkata Ramya, P.K. Manjunath and Anju S. Pillai
Abstract: The concept of context switching is extremely recognized in a multithreaded environment where different tasks are scheduled to run on a uni-core platform. However, in real time systems the overhead caused by the context switching is extremely crucial as missing the deadlines can cause serious hazards. This study addresses the overhead of context switching through hardware approach using ARM cortex M4 based TM 4 C123 GH 6 PM controller. The cortex M4 architecture provides a concept called tail chaining which can reduce the state that has to be saved and restored in the simultaneous occurrence of interrupts. The developed scheduler is capable of implementing both static and dynamic scheduling policies with reduced context switch overhead. The proposed scheduler implementation reduces the latency by reducing the context switch time to 6 clock cycles when compared to 46 clock cycles latency taken by a conventional real time operating system.
Varahagiri Venkata Ramya, P.K. Manjunath and Anju S. Pillai, 2017. Fast Context Switches: Interrupt Driven Scheduler for ARM Cortex Platforms. Journal of Engineering and Applied Sciences, 12: 8317-8322.