Cooperative Memory Deduplication With Intel Data Streaming Accelerator

Memory deduplication plays a critical role in reducing memory consumption and the total cost of ownership (TCO) in hyperscalers, particularly as the advent of large language models imposes unprecedented demands on memory resources. However, conventional CPU-based memory deduplication can interfere with co-running applications, significantly impacting the performance of time-sensitive workloads. Intel introduced the on-chip Data Streaming Accelerator (DSA), providing high-performance data movement and transformation capabilities, including comparison and checksum calculation, which are heavily utilized in the deduplication. In this work, we enhance a widely-used kernel-space memory deduplication feature, Kernel Samepage Merging (ksm), by selectively offloading these operations to the DSA. Our evaluation demonstrates that CPU-based ksm can lead to 5.0–10.9× increase in the tail latency of co-running applications while DSA-based ksm limits the latency increase to just 1.6× while achieving comparable memory savings.