Rethinking Dead Block Prediction for Intermittent Computing

Existing dead block predictors have proven to be effective in reducing cache leakage power of conventional systems. However, prior work is significantly less effective in energy harvesting systems in that it does not take into account their unique characteristic, i.e., frequent power failure during program execution. Even if some cache blocks are predicted to be live, they may not be used due to their loss upon power failure. In response, this paper introduces EDBP, an extension to existing dead block predictors, to enhance their performance in various energy harvesting environments. EDBP can identify and deactivate those cache blocks that are not reused before upcoming power failure-though they are considered live by the existing predictor-thereby lowering cache leakage and preserving more energy for forward execution progress. Experimental results show that for 20 applications from Mediabench and MiBench, EDBP alone reduces total energy consumption by 6.5% and improves performance by 6.9% compared to the baseline with no dead block predictor. When combined with a conventional dead block predictor (Cache Decay), EDBP achieves 9.8% reduction in total energy consumption—approaching the theoretical minimum—and 11.9% performance improvement.