Soft2LM: Application Guided Heterogeneous Memory Management
Michael J. Giardino, Kshitij Doshi, Bonnie Heck Ferri · 2016
This paper introduces a software policy for memory management in heterogeneous memory systems in order to improve the trade-offs between performance and power consumption, while attempting to make the best use of different characteristics of the underlying memory technologies. In this policy, the operating system and the application co-schedule page management in order to make informed decisions about page allocation and migration. Software-Controlled 2- Level Memory (Soft2LM) is a hardware-agnostic approach for efficient usage of heterogeneous memory that allows for region-based allocations, migrations, and application advice. We include analysis of the access characteristics of the PARSEC 3.0 suite of benchmarks, both as motivation for software-guided intelligent page placement as well as for understanding where application advice can make a difference. Our evaluation running PARSEC on our Soft2LM Linux kernel shows an average 4.7x improvement over comparable RAMDISK- based swapping. Even when migrating 100 and 1000 pages per second between regions, Soft2LM performs comparably to a stock system with twice the available DRAM, showing a 1.8\% and 0.7\% improvement, respectively.