Title
LLC-Guided Data Migration in Hybrid Memory Systems
Abstract
Although 3D-stacked DRAM offers substantially higher bandwidth than commodity DDR DIMMs, it cannot yet provide the necessary capacity to replace the bulk of the memory. A promising alternative is to use flat address space, hybrid memory systems of two or more levels, each exhibiting different performance characteristics. One such existing approach employs a near, high bandwidth 3D-stacked memory, placed on top of the processor die, combined with a far, commodity DDR memory, placed off-chip. Migrating data from the far to the near memory has significant performance potential, but also entails overheads, which may diminish migration benefits or even lead to performance degradation. This paper describes a new data migration scheme for hybrid memory systems that takes into account the above overheads and improves migration efficiency and effectiveness. It is based on the observation that migrating memory segments, which are (partly) present in the Last-Level Cache (LLC) introduces lower migration traffic. Our approach relies on the state of the LLC cachelines to predict future reuse and select memory segments for migration. Thereby, the segments are migrated when present (at least partly) in the LLC incurring lower cost. Our experiments confirm that our approach outperforms current state-of-the art migration designs improving system performance by 12.1% and reducing memory system dynamic energy by 13.2%.
Year
DOI
Venue
2019
10.1109/IPDPS.2019.00101
2019 IEEE International Parallel and Distributed Processing Symposium (IPDPS)
Keywords
Field
DocType
Memory Systems,Data Migration
Address space,Dram,DIMM,Reuse,Cache,Computer science,Bandwidth (signal processing),Distributed computing,Overhead (business),Data migration
Conference
ISSN
ISBN
Citations 
1530-2075
978-1-7281-1247-3
1
PageRank 
References 
Authors
0.35
19
4
Name
Order
Citations
PageRank
Evangelos Vasilakis182.48
Vassilis Papaefstathiou29713.71
Pedro Trancoso337743.79
Ioannis Sourdis445644.17