Jul 2026· ACM SIGOPS Operating Systems Review· Vol 60, pp. 41 - 49· 0 citations· 26 references
TL;DR
This work presents Oneiros, a dynamic remapping engine for multi-tenant LLM serving that dynamically repurposes GPU memory allocated for model parameters as KV cache capacity, enabling nonblocking, unidirectional parameter transfer.
Abstract
KV cache accelerates LLM inference by avoiding redundant computation, but its rapidly growing memory footprint makes GPU memory a primary bottleneck in modern serving systems. Recent approaches extend GPU memory using CPU memory through KV-cache swapping. However, because KV cache is continuously updated during decoding, swapping introduces substantial synchronization and bidirectional transfer overheads. We present Oneiros, a dynamic remapping engine for multi-tenant LLM serving. Oneiros is based on a simple observation: unlike KV cache, model parameters remain immutable during inference. Instead of swapping KV cache itself, Oneiros dynamically repurposes GPU memory allocated for model parameters as KV cache capacity, enabling nonblocking, unidirectional parameter transfer. This approach is particularly effective in multi-tenant environments, where memory allocated to inactive models can be reclaimed dynamically for active workloads. We implement Oneiros in vLLM and evaluate it on modern GH200 systems. Compared to vLLM, Oneiros reduces tail latency by up to 99.3% and improves throughput by up to 86.7%. Compared to KV-cache swapping approaches, Oneiros achieves substantially higher throughput by avoiding synchronization overheads during runtime memory extension. Source code of Oneiros is available at https://github.com/UT-SysML/Oneiros/1.
A bandwidth-oriented memory allocation mechanism, named AdaptiveKV, which is self-adaptive to CXL-enabled memory pools and KV cache offloading scales for LLM inference acceleration, and achieves a maximum speedup in LLM inference throughput compared to the state-of-the-art strategies.
Yibo Tang, Lizhou Wu, Yang Ou et al.· ACM Transactions on Architec...· 0 citations
OasisKV is presented, a memory-centric LLM inference system design that alleviates HBM capacity pressure by decoupling full KV-cache storage from HBM during LLM decoding and observes that future important tokens can be predicted accurately in advance using lookahead tokens drafted by speculative decoding (SD).
Can Xiao, Sukmin Cho, Junbong We et al.· 0 citations
Long-context, multi-turn, and agentic LLM workloads increasingly reuse previously processed context, making KV-cache reuse essential for reducing redundant computation. However, this reuse shifts the bottleneck to the memory tier that stores and serves reusable KV states at cluster scale. GPU HBM and host DRAM are too costly to scale to TB-scale shared context capacity, motivating remote tiers built from lower-cost, higher-capacity media. This paper presents HyMCache, a CXL memory rack for multi-turn LLM serving. We build the memory rack using cost-efficient CXL-hybrid memory (CXL-HM), which combines a small amount of in-device DRAM with large SSD-backed capacity behind a CXL interface. By exploiting the read-dominant, predictable, and append-only nature of multi-turn KV-cache access, HyMCache rethinks DRAM management within CXL-HM to efficiently support TB-scale SSD-backed KV reuse. It uses request-level prefix prefetching and opportunistic write buffering to stage latency-critical reads in device DRAM, enabling DRAM-scale KV-cache efficiency at SSD-level cost. We evaluate HyMCache on a real CXL-HM prototype under both single-aggregator and PD-disaggregated serving configurations. Under the same DRAM budget, HyMCache outperforms local LMCache by 3.0x in single-node serving and 1.45x in PD-disaggregated serving. Compared with 1 TB distributed-DRAM Mooncake, HyMCache incurs about 30% lower performance but uses 16x less DRAM.
Hakbeom Jang, Inho Song, Hoshik Kim et al.· 0 citations
This work proposes SAI, a mechanism that virtualizes shared memory into the L2 cache to improve GPU performance for AI applications and introduces an L2 cache management strategy that integrates associativity-based virtual page allocation and a replacement information table, reducing page-swapping overhead while preserving L2 cache performance.
Hanqing Li, Tiejun Li, Sheng Ma et al.· ACM Transactions on Design A...· 0 citations
Modern LSM-based KV stores reduce read amplification with two in-memory caches, namely a table cache for metadata such as index and Bloom-filter blocks, and a data cache for value blocks. These caches draw from a shared memory budget and are jointly exercised on the read path, so the metadata-data split is inherently coupled and end-to-end read latency can be non-monotonic in the allocation. Allocating more memory to one cache may improve its hit rate but evict blocks from the other, yielding hard-to-predict performance especially under dynamic workloads. Most systems therefore rely on fixed, ratio-based heuristics, which can be far from optimal. We present CoCache, a cooperative cache-management framework that continuously tunes the metadata-data cache split. CoCache combines lightweight online hotness tracking with a unified latency model that captures the coupled impact of metadata and data caching on the read path. Using these signals, CoCache efficiently searches candidate splits and applies the one with the lowest predicted latency, then re-optimizes as access patterns shift. We implement CoCache in RocksDB and evaluate it on synthetic, benchmark, and production-derived workloads. Compared to state-of-the-art baselines, CoCache improves cache hit rates by up to 1.56 × , increases read throughput by up to 1.43 × , and reduces read latency by up to 31.2%.
Haoting Tang, Wenzhe Zhu, Qingyang Zhang et al.· International Conference on...· 0 citations