MultiAlloc:面向KV缓存量化的预算感知精度分配
MultiAlloc: Budget-Aware Precision Allocation for KV Cache Quantization
AI总结:
MultiAlloc是一种KV缓存量化的预算感知精度分配框架,通过离线分析实现层级与令牌级精度资源的自适应分配,在固定内存预算下优于多种现有KV缓存量化方法。
摘要:
键值(KV)缓存是大语言模型(LLM)推理过程中内存消耗的主要来源,尤其在长上下文和复杂推理场景下更为突出。现有的KV缓存量化方法已探索了不同的压缩粒度,包括层级精度调整和令牌级信息保留。然而在实际部署中,核心挑战不仅是压缩,而是如何在固定KV缓存内存预算下,将有限的量化资源分配给异构的精度保留策略。我们提出MultiAlloc,这是一种用于KV缓存量化的、由分析引导的精度分配框架,可自适应地在层级精度增强和令牌级保留之间分配有限的量化资源。MultiAlloc采用轻量级离线分析来表征层敏感性和令牌重要性,从而在固定内存约束下实现自适应精度分配。在分析得到的内存-精度权衡的引导下,它无需在线分配搜索即可自动推导有效的精度分配策略,并在推理过程中应用该策略。在推理和长上下文基准上进行的大量实验表明,MultiAlloc在匹配的内存预算下,相较于层级、令牌级以及近期的多粒度KV缓存量化方法,在Mistral、Llama、DeepSeek-Qwen和QwQ等多种模型上均实现了持续提升。
英文摘要:
The Key-Value (KV) cache constitutes a dominant source of memory consumption during large language model (LLM) inference, particularly in long-context and complex reasoning scenarios. Existing KV cache quantization methods have explored different compression granularities, including layer-wise precision adjustment and token-level information preservation. In practical deployment, however, the key challenge is not merely compression, but how to allocate limited quantization resources among heterogeneous precision preservation strategies under a fixed KV cache memory budget. We propose MultiAlloc, a profiling-guided precision allocation framework for KV cache quantization that adaptively distributes limited quantization resources between layer-wise precision enhancement and token-wise preservation. MultiAlloc employs lightweight offline profiling to characterize layer sensitivity and token importance, enabling adaptive precision allocation under a fixed memory constraint. Guided by the profiled memory--accuracy trade-off, it automatically derives an effective precision allocation strategy without online allocation search, and applies the resulting policy during inference. Extensive experiments on reasoning and long-context benchmarks demonstrate that MultiAlloc consistently improves over layer-wise, token-wise, and recent multi-granularity KV cache quantization methods under matched memory budgets across diverse models, including Mistral, Llama, DeepSeek-Qwen, and QwQ.
机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。