Online testing of many-core systems in the Dark Silicon era

As the dark silicon era is about to embrace, it is not anymore possible to attain commensurate performance benefits by increasing the number of transistors due to thermal design power. Dark Silicon issue stresses that a fraction of silicon chip being able to switch in full frequency is dropping and designers will soon face the growing underutilization inherent in future technologies. On the other hand, by reducing the transistor size, susceptibility to internal defects drastically increases and large ranges of defects such as aging or transient faults will be shown up more frequently. In this paper, we propose an online test scheduling algorithm using software based self-test for dark silicon era to test dark cores while considering thermal design power of the system. As the dark area of the system is dynamic and reshapes at a runtime, the tested cores can be used by other applications in the near future. Empirical results show the effectiveness of the proposed algorithm in terms of applicability and fault coverage with a negligible negative impact on the system throughput.