fsync-aware Multi-Buffer FTL for Improving the fsync Latency with Open-Channel SSDs

Abstract

Open-Channel SSDs are widely studied because of their advantages such as predictable latency, efficient data placement, and I/O scheduling. Currently, the Linux kernel includes pblk (The Physical Block Device), a host FTL that supports Open-Channel SSDs. In addition, there are recent studies that expand the single-threaded architecture of pblk to multi-threaded architecture: MT-FTL and QBLK. However, both pblk and recent studies were designed without considering fsync latency. However, since the fsync system call is performed synchronously, has a great effect on the performance of the system. In this paper, we propose FA-FTL, which is a host FTL considering fsync latency. Experiments show that FA-FTL is 141% higher than pblk and 119% higher than MT-FTL.