一种避免页迁移的混合内存页管理策略

Hybrid Memory Page Management Strategy of Avoiding Page Migrations

相变存储器(Phase-change Memory,PCM)具有非易失性、能耗低、密度大等诸多优点,将成为下一代主流存储器.然而,相变存储器的写操作速度慢以及写次数有限的特征限制其立马替代现有主流的双倍速率同步动态随机存储器(DDR系列).为了发挥两种存储介质各自的优势,目前主要采用混合内存的体系结构,该结构不仅包括新型的相变存储器同时还包括传统的动态随机存储器.针对混合内存结构,数据划分变得尤为重要,目前大多数划分算法采用页面迁移作为保障效率和损耗的手段.但是迁移需要消耗大量的处理器资源,同时导致大量不必要的写相变存储器的操作,降低混合内存系统的性能和寿命.为了减少迁移操作带来的效率损失,本文提出一种避免页迁移的混合内存页管理策略(PMP)提高混合内存系统的性能和寿命.该策略最大的优势在于提出了一种基于虚拟内存页的访存行为特征分析方法,能够高效准确的获取各页的访存行为,所以在系统运行过程中避免因页分配错误导致的页迁移操作.实验表明本文提出的避免页迁移的混合内存页管理策略(PMP)能够有效的提高混合内存系统的性能和寿命.

Phase-change Memory( PCM) will become the next-generation mainstream storage for its advantages of non-volatility,low energy consumption,high density and so on. However,low write speed and limited write times of PCM will restrict it replace the existing mainstream memory Double Data Rate Synchronous Dynamic Random Access Memory( DDR SDRAM) instantly. In order to take both advantages of two memory mediums,the hybrid memory architecture is mainly used presently. This architecture includes both PCM and DRAM. For the hybrid memory architecture,data partitioning could be particularly important. At present,most partition algorithms adopt page migrations to guarantee efficiency. But page migrations consume processor resources and cause lots of unnecessary write operations to PCM which will reduce the performance of hybrid memory system as well as the system life. In order to reduce cost from migration,in this paper,we propose a hybrid memory page management strategy which avoids page migrations( PMP)to increase the performance of hybrid memory system as well as the system life. The most advantage of this strategy is the page allocation policy which is based on virtual memory pages. In this case,it will avoid page migration operations caused by page allocation errors.Experiments show the proposed PMP increased the performance of hybrid memory system as well as the system life efficiently.