ParisKV: Fast and Drift-Robust KV-Cache Retrieval for Long-Context LLMs

Code

• github.com/amy-77/pariskv
  OfficialIn paper★ 0

Abstract

KV-cache retrieval is essential for long-context LLM inference, yet existing methods struggle with distribution drift and high latency at scale. We introduce ParisKV, a drift-robust, GPU-native KV-cache retrieval framework based on collision-based candidate selection, followed by a quantized inner-product reranking estimator. For million-token contexts, ParisKV supports CPU-offloaded KV caches via Unified Virtual Addressing (UVA), enabling on-demand top-k fetching with minimal overhead. ParisKV matches or outperforms full attention quality on long-input and long-generation benchmarks. It achieves state-of-the-art long-context decoding efficiency: it matches or exceeds full attention speed even at batch size 1 for long contexts, delivers up to 2.8 higher throughput within full attention's runnable range, and scales to million-token contexts where full attention runs out of memory. At million-token scale, ParisKV reduces decode latency by 17 and 44 compared to MagicPIG and PQCache, respectively, two state-of-the-art KV-cache Top-k retrieval baselines, code is available at https://github.com/amy-77/ParisKV/tree/main.

Reproductions