KVpop -- Key-Value Cache Compression with Predictive Online Pruning
This work addresses the substantial memory and bandwidth bottlenecks in autoregressive decoding caused by the linear growth of key-value (KV) cache with context length. Existing KV cache eviction methods rely on static heuristics or proxy scores that inadequately estimate each cache entry’s contribution to future token generation, often resulting in significant performance degradation. To overcome this limitation, the authors propose a supervised learning framework that directly optimizes KV cache eviction under a fixed budget by leveraging future attention targets as supervision signals. They further introduce a delayed memory scorer that implicitly guides online pruning using near-future context, eliminating the need for explicit computation of dense attention maps. Evaluated on Qwen3-4B and Qwen3-8B, the method retains 97%–98% of original model performance at aggressive compression rates of 75%–88%, substantially outperforming current baselines.