Blk-Tune: Blocking Parameter Auto-Tuning to Minimize Input-Output Traffic for Flash-Based Out-of-Core Stencil Computations

This paper proposes the auto-tuning system designed for flash-based out-of-core stencil computations. Blk-Tune is a runtime blocking parameter auto-tuning system that enables the use of flash memory as an extension of main memory. It incorporates automatic hardware information retrieval using Portable Hardware Locality and minimizes the amount of data transferred between the flash device and DRAM, which is the most dominant factor affecting the performance of out-of-core algorithms using flash. The use of explicit highly parallel asynchronous I/O to a flash device together with this auto-tuning system offers great advantages over the mmap method, in which a flash file is memory mapped. Blk-Tune allows users to easily achieve maximum performance of large-scale stencil computations in different hardware and application settings.