Kindle: A Comprehensive Framework for Exploring OS-Architecture Interplay in Hybrid Memory Systems

Computers with hybrid memory can offer the benefits of both DRAM and NVM technologies, where NVM provides higher capacity and data persistence while DRAM offers better performance. One of the primary objectives in hybrid memory systems is to design mechanisms and policies to take advantage of the underlying memory technologies to improve overall system performance and explore new usage scenarios. This paper introduces an open-source framework, Kindle, based on gem5 and gemOS, to explore and prototype research ideas in hybrid memory systems crossing the hardware-software boundaries, and perform comprehensive empirical evaluation. Kindle provides mechanisms to realize process persistence in hybrid memory systems while facilitating analysis of different design challenges and alternatives. As an illustration, we compare two design choices to maintain the virtual to physical address translation information (in the page table) for achieving process persistence in Kindle. Moreover, we demonstrate the utility of Kindle by prototyping state-of-the-art research ideas for hybrid memory systems to show that new insights can be derived using the facilities provided in the proposed framework.