ConsistKV: Layer Adaptive KV Cache Compression via Cross Layer Consensus

Dongjie Xu, Kai Qian, Weijie Shi, Fenglei Jin, Jiajie Xu


Abstract
As LLMs process increasingly long contexts, the KV cache has become a major source of memory and bandwidth overhead during inference. Existing methods compress the KV cache by preserving attention sinks, recent tokens, or layer-local important tokens, but they rarely exploit how token importance is shared and specialized across layers. In this paper, we introduce ConsistKV, an adaptive KV cache compression method that exploits consensus in token importance across layers. For each layer, ConsistKV aggregates importance scores from neighboring layers to identify shared contextual anchors, while using residual local importance to preserve tokens that are salient to the current layer. It further estimates the cache demand of each layer from disagreement between layers and importance dispersion, enabling adaptive budget allocation under a fixed global cache budget. Experiments on LongBench show that ConsistKV achieves the highest average performance among evaluated KV cache compression baselines under the same cache budget.
Anthology ID:
2026.findings-emnlp.1793
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
38344–38355
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1793/
DOI:
Bibkey:
Cite (ACL):
Dongjie Xu, Kai Qian, Weijie Shi, Fenglei Jin, and Jiajie Xu. 2026. ConsistKV: Layer Adaptive KV Cache Compression via Cross Layer Consensus. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 38344–38355, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
ConsistKV: Layer Adaptive KV Cache Compression via Cross Layer Consensus (Xu et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1793.pdf