How to Steal CPU Idle Time When Synchronous I/O Mode Becomes Promising
Chun-Feng Wu, Yuan-Hao Chang, Ming-Chang Yang, Tei‐Wei Kuo · 2024
The advent of Ultra-Low-Latency storage devices has narrowed the performance gap between storage and CPU in computing platforms, facilitating synchronous I/O adoption. Yet, this approach introduces substantial busy waiting time and underutilizes computing units. To address this, we propose a light-weighted Idle-Time-Stealing (ITS) design. This involves a self-improving thread conducting prefetching for high-priority processes during synchronous I/O, and an I/O-waiting process continuing subsequent instruction executions when justifiable. Another thread, the self-sacrificing thread, proactively switches low-priority process I/O requests from synchronous to asynchronous mode, prioritizing high-priority executions. Experimental results demonstrate the effectiveness of our ITS design in reducing CPU idle time.