一句话：提出 BCD 去重，通过压缩与去重结合利用缓存行间部分冗余，提升主存有效容量。
传统内存压缩与去重无法利用多个缓存行之间的部分数据冗余，限制了主存有效容量。本文提出 Base and Compressed Difference (BCD) 去重，将压缩与去重结合来编码缓存行间的部分匹配，并在现代存储层次中实现，对末级缓存（LLC）和主存数据同时压缩，仅需适度面积开销。实验在 SPEC2017、DaCapo、TPC-DS 和 TPC-H 上取得平均 1.94× 压缩比，比最佳先前工作高 48.4%；周期级仿真显示 SPEC2017 性能平均提升 2.7%，原因在于 LLC 有效容量增加。总体表明 BCD 能以很小性能开销显著提升主存容量。
In this paper, we identify new partial data redundancy among multiple cache lines that are not exploited by traditional memory compression or memory deduplication. We propose Base and Compressed Difference (BCD) deduplication that effectively utilizes the partial matches among cache lines through a novel combination of compression and deduplication to increase the effective capacity of main memory. Experimental results show that BCD achieves the average compression ratio of 1.94× for SPEC2017, DaCapo, TPC-DS, and TPC-H, which is 48.4% higher than the best prior work. We also present an efficient implementation of BCD in a modern memory hierarchy, which compresses data in both the last-level cache (LLC) and main memory with modest area overhead. Even with additional meta-data accesses and compression/deduplication operations, cycle-level simulations show that BCD improves the performance of the SPEC2017 benchmarks by 2.7% on average because it increases the effective capacity of the LLC. Overall, the results show that BCD can significantly increase the capacity of main memory with little performance overhead.
@inproceedings{paperbot6103,
title = {BCD deduplication: effective memory compression using partial cache-line deduplication},
author = {Sungbo Park and Ingab Kang and Yaebin Moon and Jung Ho Ahn and G. Edward Suh},
booktitle = {ASPLOS},
year = {2021},
doi = {10.1145/3445814.3446722}
}