Approximate Similarity-Aware Compression for Non-Volatile Main Memory  

作　　者：陈章玉 华宇 左鹏飞 孙园园 郭云程 Zhang-Yu Chen;Yu Hua;Peng-Fei Zuo;Yuan-Yuan Sun;Yun-Cheng Guo(Wuhan National Laboratory for Optoelectronics,School of Computer Science and Technology,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]Wuhan National Laboratory for Optoelectronics,School of Computer Science and Technology,Huazhong University of Science and Technology,Wuhan 430074,China

出　　处：《Journal of Computer Science & Technology》2024年第1期63-81,共19页计算机科学技术学报（英文版）

基　　金：This work was supported in part by the National Natural Science Foundation of China under Grant Nos.62125202 and U22B2022.

摘　　要：Image bitmaps,i.e.,data containing pixels and visual perception,have been widely used in emerging applica-tions for pixel operations while consuming lots of memory space and energy.Compared with legacy DRAM(dynamic ran-dom access memory),non-volatile memories(NVMs)are suitable for bitmap storage due to the salient features of high density and intrinsic durability.However,writing NVMs suffers from higher energy consumption and latency compared with read accesses.Existing precise or approximate compression schemes in NVM controllers show limited performance for bitmaps due to the irregular data patterns and variance in bitmaps.We observe the pixel-level similarity when writing bitmaps due to the analogous contents in adjacent pixels.By exploiting the pixel-level similarity,we propose SimCom,an approximate similarity-aware compression scheme in the NVM module controller,to efficiently compress data for each write access on-the-fly.The idea behind SimCom is to compress continuous similar words into the pairs of base words with runs.The storage costs for small runs are further mitigated by reusing the least significant bits of base words.SimCom adaptively selects an appropriate compression mode for various bitmap formats,thus achieving an efficient trade-off be-tween quality and memory performance.We implement SimCom on GEM5/zsim with NVMain and evaluate the perfor-mance with real-world image/video workloads.Our results demonstrate the efficacy and efficiency of our SimCom with an efficient quality-performance trade-off.

关 键 词：approximate computing data compression memory architecture non-volatile memory 

分 类 号：TP333[自动化与计算机技术—计算机系统结构]