How does prefix caching interact with continuous batching, and what are the memory management implications?

Prefix caching allows the system to reuse KV blocks for shared prompt prefixes, such as system prompts used across multiple requests. When integrated with continuous batching, these blocks must be reference-counted and reclaimed only when all sequences sharing the prefix have completed. Memory management relies on eviction policies like LRU or radix-tree-based approaches to determine the cache hit rate. For chatbot workloads involving long system prompts, the prefix cache hit rate is the primary factor driving effective throughput.