Operating system scheduling for efficient online self-test in robust systems

Very thorough online self-test is essential for overcoming major reliability challenges such as early-life failures and transistor aging in advanced technologies. This paper demonstrates the need for operating system (OS) support to efficiently orchestrate online self-test in future robust systems. Experimental data from an actual dual quad-core system demonstrate that, without software support, online self-test can significantly degrade performance of soft real-time and computation-intensive applications (by up to 190%), and can result in perceptible delays for interactive applications. To mitigate these problems, we develop OS scheduling techniques that are aware of online self-test, and schedule/migrate tasks in multi-core systems by taking into account the unavailability of one or more cores undergoing online self-test. These techniques eliminate any performance degradation and perceptible delays in soft real-time and interactive applications (otherwise introduced by online self-test), and significantly reduce the impact of online self-test on the performance of computation-intensive applications. Our techniques require minor modifications to existing OS schedulers, thereby enabling practical and efficient online self-test in real systems.