A Smart Cache for a SmartNIC! Scaling End-Host Networking to 400Gbps and Beyond

•Virtual switches optimize performance by caching multi-table lookup traversals to single-table Megaflow cache, which SmartNICs offload directly to hardware •We present Gigaflow: a multi-table sub-traversal cache for SmartNICs, designed to capture a much larger rule space using the same cache size •Open vSwitch caches traversals into Megaflow and can't share sub-traversals among traffic, making the captured rule space proportional to cache size •By caching sub-traversals into a multi-table cache, we can capture 3 orders of magnitude more rule space, attain 51% higher cache hit rate, and 31% lower end-to-end packet latency, with manageable processing overhead