FlowMM: Cross-Modal Information Flow Guided KV Cache Merging for Efficient Multimodal Context Inference

Kunxi Li, Yufan Xiong, Zhonghua Jiang, Yiyun Zhou, Zhaode Wang, Chengfei lv, Shengyu Zhang


Abstract
Traditional KV cache eviction strategies, which discard less critical KV-pairs based on attention scores, often degrade generation quality, causing context loss or hallucinations. Recent efforts shift toward KV merging, merging eviction tokens with retention tokens based on similarity. However, in multimodal scenarios, distributional differences across modality tokens and attentional biases in cross-modal interactions limit its effectiveness. This work introduces FlowMM, an adaptive framework for cross-modal information flow-guided multimodal KV cache merging. FlowMM leverages cross-modal information flow to dynamically apply layer-specific merging strategies, capturing modality-specific patterns while preserving contextual integrity. Furthermore, we introduce a sensitivity-adaptive token matching mechanism that jointly evaluates token similarity and task-critical sensitivity, merging low-risk tokens while safeguarding high-sensitivity ones. Extensive experiments across diverse leading MLLMs show that FlowMM reduces KV cache memory by 80% to 95% and decoding latency by 1.3-1.8×, while maintaining competitive task performance.
Anthology ID:
2026.emnlp-main.1116
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
25566–25575
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1116/
DOI:
Bibkey:
Cite (ACL):
Kunxi Li, Yufan Xiong, Zhonghua Jiang, Yiyun Zhou, Zhaode Wang, Chengfei lv, and Shengyu Zhang. 2026. FlowMM: Cross-Modal Information Flow Guided KV Cache Merging for Efficient Multimodal Context Inference. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 25566–25575, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
FlowMM: Cross-Modal Information Flow Guided KV Cache Merging for Efficient Multimodal Context Inference (Li et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1116.pdf