Putting Faulty Cores to Work

Abstract

Abstract-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 core.

Improving GPU Robustness by making use of faulty parts

“…Most of these methods are accompanied by either high hardware overhead, performance penalties, or high power consumption. In [11] and [12], a functional CPU core in a traditional multi-core processor has been assisted by a faulty core to speed up the functional core. A 40% speed up over the baseline configuration could be achieved by using I-Cache Hints, D-Cache Hints, and Branch Prediction hints for a multicore CPU system.…”