Amnesic cache management for non-volatile memory

—One characteristic of non-volatile memory (NVM) is that, even though it supports non-volatility, its retention capability is limited. To handle this issue, previous studies have focused on refreshing or advanced error correction code (ECC). In this paper, we take a different approach that makes use of the limited retention capability to our advantage. Specifically, we employ NVM as a file cache and devise a new scheme called amnesic cache management (ACM). The scheme is motivated by our observation that most data in a cache are evicted within a short time period after they have been entered into the cache, implying that they can be written with the relaxed retention capability. This retention relaxation can enhance the overall cache performance in terms of latency and energy since the data retention capability is proportional to the write latency. In addition, to prevent the retention relaxation from degrading the hit ratio, we estimate the future reference intervals based on the ...

• Type: Journal
• Year: 2015
• Where: MSS
• Authors: Dongwoo Kang, Seungjae Baek, Jongmoo Choi, Donghee Lee, Sam H. Noh, Onur Mutlu
• Keywords: Hardware, MSS 2015