Preliminary Analysis of a Write Reduction Method for Non-volatile Main Memory on Jikes RVM

Abstract

There are many researches and developments on byte accessible non-volatile memory (NVM). Byte accessible NVM can be used as not only storage but also main memory. Non-volatile main memory has two significant merits: reducing power consumption of main memory, flexible system standby and fast resume. However, NVM has bottlenecks in writing and limitation on the number of writing. To overcome this problem, there are some researches on hybrid memory architectures, which combine NVM and DRAM. On hybrid memory architectures, it needs to collect program characteristics of write access and allocate DRAM or NVM based on that characteristics. Previous works proposed to collect and allocate at hardware level or operating system level. At hardware or OS level, memory allocators can collect writing information of wide range of processes. However, they do not know contents of written data, thus they cannot allocate memory based on data characteristics. To solve this problem, we propose a method to obtain characteristics of writing and assign DRAM or NVM based on that information in previous work. The method applies write barrier of language runtimes to collect writing characteristics. This paper describes modification of our previous work and preliminary analysis for implementation the method on Jikes RVM.