Sampling Dead Block Prediction for Last-Level Caches

Last-level caches (LLCs) are large structures with significant power requirements. They can be quite inefficient. On average, a cache block in a 2MB LRU-managed LLC is dead 86% of the time, i.e., it will not be referenced again before it is evicted. This paper introduces sampling dead block prediction, a technique that samples program counters (PCs) to determine when a cache block is likely to be dead. Rather than learning from accesses and evictions from every set in the cache, a sampling predictor keeps track of a small number of sets using partial tags. Sampling allows the predictor to use far less state than previous predictors to make predictions with superior accuracy. Dead block prediction can be used to drive a dead block replacement and bypass optimization. A sampling predictor can

• Type: Journal
• Year: 2010
• Where: MICRO
• Authors: Samira Manabi Khan, Yingying Tian, Daniel A. Jimenez
• Keywords: Cache Block, Dead Block, Dead Block Prediction, Hardware, MICRO 2010