LEPA: Latency estimation-based page allocation for improving SSD performance

Modern solid state drives (SSDs) based on NAND Flash Memory (NFM) have multi-level parallel resources to enhance their I/O performance. The page allocation policy, which is responsible for allocating logical pages to physical parallel resources, directly affects the efficiency of SSD parallelism utilization. Traditionally, the load-balancing page allocation policy relies on the number of commands rather than their actual latency. However, this policy fails to effectively balance the execution latency skew among the various parallel units of SSD, leading to parallelism loss.