Protective redundancy overhead reduction using instruction vulnerability factor
Due to modern technology trends, fault tolerance (FT) is acquiring an ever increasing research attention. To reduce the overhead introduced by the FT features, several techniques have been proposed. One of these techniques is Instruction-Level Fault Tolerance Configurability (ILCOFT). ILCOFT enables application developers to protect different instructions at varying degrees, devoting more resources to protect the most critical instructions, and saving resources by weakening protection of other instructions. It is, however, not trivial to assign a proper protection level for every instruction. This work introduces the notion of Instruction Vulnerability Factor (IVF), which evaluates how faults in every instruction affect the final application output. The IVF is computed off-line, and is then used by ILCOFT-enabled systems to assign the appropriate protection level to every instruction. IVF releases the programmer from the need to assign the necessary protection level to every instruction by hand. Experimental results demonstrate that IVF-based ILCOFT reduces the instruction duplication performance penalty by up to 77%, while the maximum output damage due to undetected faults does not exceed 0.6% of the total application output.
Published in: Proceedings of the 7th ACM international conference on Computing frontiers, 10.1145/1787275.1787342, Association for Computing Machinery (ACM)