Vault 2017

Modern hard disk drives can achieve higher throughput for small IO accesses through queuing and scheduling optimizations within the device. Unfortunately, higher throughput for small IO comes at the cost of larger tail latencies. In this presentation, we will explore one option to improve tail latencies while minimizing the impact to throughput by leveraging iopriority information. I will discuss the recent patches that were merged in the Linux Kernel that enable SATA HDDs to leverage iopriority information. In addition, this presentation will cover how to use iopriority and provide some measured results.