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The increasing scale and complexity of large language models (LLMs) pose significant inference latency challenges, primarily due to their autoregressive decoding paradigm characterized by the sequential nature of next-token prediction. By…

Computation and Language · Computer Science 2025-08-15 Keyu Chen , Zhifeng Shen , Daohai Yu , Haoqian Wu , Wei Wen , Jianfeng He , Ruizhi Qiao , Xing Sun

The growing demand for large language models (LLMs) requires serving systems to handle many concurrent requests with diverse service level objectives (SLOs). This exacerbates head-of-line (HoL) blocking during the compute-intensive prefill…

Distributed, Parallel, and Cluster Computing · Computer Science 2026-02-19 Chia-chi Hsieh , Zan Zong , Xinyang Chen , Jianjiang Li , Jidong Zhai , Lijie Wen

Disaggregated LLM serving improves resource efficiency by separating the compute-intensive prefill phase from the latency-critical decode phase. However, this architecture introduces a fundamental bottleneck: key/value (KV) tensors…

Distributed, Parallel, and Cluster Computing · Computer Science 2025-12-23 Dongha Yoon , Younghoon Min , Hoshik Kim , Sam H. Noh , Jongryool Kim

Serving disaggregated large language models (LLMs) over tens of thousands of xPU devices (GPUs or NPUs) with reliable performance faces multiple challenges. 1) Ignoring the diversity (various prefixes and tidal requests), treating all the…

Diffusion large language models (dLLMs) generate text by iteratively denoising masked token sequences. Although dLLMs can predict all masked positions in parallel within each step, the large number of denoising iterations still makes…

Computation and Language · Computer Science 2026-05-18 Shengyin Sun , Yiming Li , Renxi Liu , Xinqi Li , Hui-Ling Zhen , Weizhe Lin , Chen Chen , Xianzhi Yu , Mingxuan Yuan , Chen Ma

Production vLLM fleets typically provision each instance for the worst-case context length, leading to substantial KV-cache over-allocation and under-utilized concurrency. In practice, 80-95% of requests are short, yet are served under…

Computation and Language · Computer Science 2026-04-10 Xunzhuo Liu , Bowei He , Xue Liu , Andy Luo , Haichen Zhang , Huamin Chen

Existing large language model (LLM) serving systems typically employ Prefill-Decode disaggregated architecture to prevent computational interference between the prefill and decode phases. However, in real-world LLM serving scenarios,…

Distributed, Parallel, and Cluster Computing · Computer Science 2025-11-07 Yu Wu , Tongxuan Liu , Yuting Zeng , Siyu Wu , Jun Xiong , Xianzhe Dong , Hailong Yang , Ke Zhang , Jing Li

Each request in LLM inference goes through two phases: compute-bound prefill and memory-bandwidth-bound decode. To improve GPU utilization, recent systems use hybrid batching that combines the prefill and decode phases of different requests…

Machine Learning · Computer Science 2025-02-18 Aditya K Kamath , Ramya Prabhu , Jayashree Mohan , Simon Peter , Ramachandran Ramjee , Ashish Panwar

Large language models (LLMs) have driven significant advancements across diverse NLP tasks, with long-context models gaining prominence for handling extended inputs. However, the expanding key-value (KV) cache size required by Transformer…

Machine Learning · Computer Science 2024-10-08 Lijie Yang , Zhihao Zhang , Zhuofu Chen , Zikun Li , Zhihao Jia

Transformer-based large language model (LLM) inference serving is now the backbone of many cloud services. LLM inference consists of a prefill phase and a decode phase. However, existing LLM deployment practices often overlook the distinct…

Distributed, Parallel, and Cluster Computing · Computer Science 2024-01-23 Cunchen Hu , Heyang Huang , Liangliang Xu , Xusheng Chen , Jiang Xu , Shuang Chen , Hao Feng , Chenxi Wang , Sa Wang , Yungang Bao , Ninghui Sun , Yizhou Shan

Context retrieval systems for LLM inference face a critical challenge: high retrieval latency creates a fundamental tension between waiting for complete context (poor time-to-first-token) and proceeding without it (reduced quality).…

Databases · Computer Science 2026-05-19 Rajveer Bachkaniwala , Chengqi Luo , Richard So , Divya Mahajan , Kexin Rong

Long-context inference in decoder-only language models is costly because long prompts are processed during Prefill, cached at every layer, and repeatedly attended to during autoregressive Decode. We introduce \emph{Shallow Prefill, dEEp…

Artificial Intelligence · Computer Science 2026-05-08 Jungsuk Oh , Hyeseo Jeon , Hyunjune Ji , Kyongmin Kong , Jay-Yoon Lee

Federated inference enhances LLM performance in edge computing through weighted averaging of distributed model predictions. However, autoregressive LLM inference requires frequent full-model forward passes across workers, severely limiting…

Signal Processing · Electrical Eng. & Systems 2026-04-29 Ce Zheng , Xinghan Wang , Jiahong Ning , Yuxuan Shi , Ning Huang , Tingting Yang

LLMs are widely adopted in production, pushing inference systems to their limits. Disaggregated LLM serving (e.g., PD separation and KV state disaggregation) improves scalability and cost efficiency, but it also turns KV into an explicit…

Distributed, Parallel, and Cluster Computing · Computer Science 2026-05-14 Zedong Liu , Xinyang Ma , Dejun Luo , Hairui Zhao , Bing Lu , Wenjing Huang , Yida Gu , Xingchen Liu , Zheng Wei , Jinyang Liu , Dingwen Tao , Guangming Tan

The performance of multi-turn, agentic LLM inference is increasingly dominated by KV-Cache storage I/O rather than computation. In prevalent disaggregated architectures, loading the massive KV-Cache from external storage creates a…

Distributed, Parallel, and Cluster Computing · Computer Science 2026-02-27 Yongtong Wu , Shaoyuan Chen , Yinmin Zhong , Rilin Huang , Yixuan Tan , Wentao Zhang , Liyue Zhang , Shangyan Zhou , Yuxuan Liu , Shunfeng Zhou , Mingxing Zhang , Xin Jin , Panpan Huang

Large language model (LLM) decoding involves generating a sequence of tokens based on a given context, where each token is predicted one at a time using the model's learned probabilities. The typical autoregressive decoding method requires…

Computation and Language · Computer Science 2024-08-20 Xukun Liu , Bowen Lei , Ruqi Zhang , Dongkuan Xu

Parallel decoding for diffusion LLMs (dLLMs) is difficult because each denoising step provides only token-wise marginal distributions, while unmasking multiple tokens simultaneously requires accounting for inter-token dependencies. We…

Machine Learning · Computer Science 2026-03-16 Bumjun Kim , Dongjae Jeon , Moongyu Jeon , Albert No

Multiple patterning lithography (MPL) is regarded as one of the most promising ways of overcoming the resolution limitations of conventional optical lithography due to the delay of next-generation lithography technology. As the feature size…

Artificial Intelligence · Computer Science 2023-03-28 Guojin Chen , Haoyu Yang , Bei Yu

Transformer-based large language models (LLMs) exhibit impressive performance in generative tasks but also introduce significant challenges in real-world serving due to inefficient use of the expensive, computation-optimized accelerators.…

Machine Learning · Computer Science 2025-04-11 Shaoyuan Chen , Wencong Xiao , Yutong Lin , Mingxing Zhang , Yingdi Shan , Jinlei Jiang , Kang Chen , Yongwei Wu

Speculative decoding (SD) accelerates large language model (LLM) inference by using a smaller draft model to propose multiple tokens that are verified by a larger target model in parallel. While prior work demonstrates substantial speedups…

Machine Learning · Computer Science 2026-05-15 Linghao Kong , Megan Flynn , Michael Peng , Nir Shavit , Mark Kurtz , Alexandre Marques