Putting Faulty Cores to Work

Since the non-cache parts of a core are less regular, compared to on-chip caches, tolerating manufacturing defects in the processing core is a more challenging problem. Due to the lack of effective solutions, disabling non-functional cores is a common practice in industry, which results in a significant reduction in system throughput. Although a faulty core cannot be trusted to correctly execute programs, we observe that for most defects, when starting from a valid architectural state, execution traces on a defective core coarsely resemble those of fault-free executions. In light of this insight, we propose a robust and heterogeneous core coupling execution scheme, Necromancer, that exploits a functionally dead core to improve system throughput by supplying hints regarding high-level program behavior. We partition the cores in a CMP system into multiple groups in which each group shares a lightweight core that can be substantially accelerated using these execution hints from a faulty c...

• Type: Journal
• Year: 2010
• Where: MICRO
• Authors: Amin Ansari, Shuguang Feng, Shantanu Gupta, Scott A. Mahlke
• Keywords: Defective Core, Faulty Core, Hardware, MICRO 2010, Processing Core