ScaleCache: A Scalable Page Cache for Multiple Solid-State Drives
Kiet Tuan Pham, Seokjoo Cho, Sangjin Lee, Lan Anh Nguyen, Hyeongi Yeo, Ipoom Jeong, Sungjin Lee, Nam Sung Kim, Yongseok Son · 2024
This paper presents a scalable page cache called ScaleCache for improving SSD scalability. Specifically, we first propose a concurrent data structure of page cache based on XArray (ccXArray) to enable access and update the page cache concurrently. Second, we introduce a direct page flush (dflush) which directly flushes pages to storage devices in a parallel and opportunistic manner. We implement ScaleCache with two techniques in the Linux kernel and evaluate it on a 64-core machine with eight NVMe SSDs. Our evaluations show that ScaleCache improves the performance of Linux file systems by up to 6.81× and 4.50× compared with the existing scheme and scalable scheme for multiple SSDs, respectively.