Shan Yu, University of California, Los Angeles; Yifan Qiao, University of California, Berkeley; Mingyuan Ma, Harvard University; Yangmin Li, Carnegie Mellon University; Shuo Yang, University of California, Berkeley; Xinyuan Tong, University of Edinburgh; Yang Wang, Intel; Zhiqiang Xie, Stanford University; Yuwei An, Carnegie Mellon University; Shiyi Cao, University of California, Berkeley; Ke Bao, LMSYS; Deepak Vij, Xiaoning Ding, and Yichen Wang, ByteDance; Qingda Lu, Alibaba Cloud; Zhong Wang, Tsinghua University; Gao Gao, Novita AI; Harry Xu and Junyi Shu, University of California, Los Angeles; Jiarong Xing, Rice University; Ying Sheng, University of California, Los Angeles
Inference providers must maintain availability for many LLMs, including low-volume but essential models, making resource efficiency increasingly important as token prices fall. Analysis of production traces reveals a dynamic bursty-group pattern in which sets of models become active together and shift over time; existing space- and time-sharing approaches lack principled mechanisms to adapt to this variability, forcing trade-offs between SLO adherence and efficiency. We observe that elastic memory allocation can unify spatial and temporal sharing. Based on this insight, we have developed Prism, a memory-centric LLM co-serving framework that applies memory ballooning to reclaim memory across models and support both forms of sharing under a single scheme. Prism’s balloon driver, referred to as kvcached, has been open-sourced at https://github.com/ovg-project/kvcached, and deployed in production environments across 10K+ GPUs.
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