arXiv Machine Learning

RW-TTT: Batched Serving for Request-Owned Test-Time Training State

RW‑TTT addresses the challenge of serving large language models (LLMs) that perform test‑time training (TTT) by reading and updating request‑owned state, such as fast weights or streaming learner state. The method tags each decoding step with its owner, version, and READ/WRITE effect, batches only compatible phases, and commits updates solely to the owning request, thereby avoiding state corruption. On a single GPU with eight fast‑weight InPlace‑TTT streams, RW‑TTT achieves 274.61 aggregate tokens per second—9.31× faster than sequential serving and 3.44× faster than per‑stream replicas—while maintaining correct behavior on the RULER long‑context benchmark.

arXiv AI
Oct 12

ReplaySSM: Cache SSM Inputs, Not State

ReplaySSM is a technique that redefines how state-space models (SSMs) handle their recurrent state by caching SSM inputs instead of the state itself. It unrolls the recurrence into a checkpoint plus a buffer of recent inputs, reducing state memory traffic by about half and enabling efficient speculative rollback. The method also allows separate precision levels for checkpoints, improving output accuracy while accelerating decoding in hybrid models such as Mamba-2 and Gated DeltaNet.

By Ze-Wei Liou, Harris Nover, Amey Naik, Andrii Skliar, Igor Shovkun, Ido Shahaf, Tri Dao
arXiv Machine Learning
3d ago

DualPace: Decoupled Scheduling and Cooperative GPU--CPU Decoding for LLM Serving

DualPace is an LLM serving runtime that decouples scheduling between a GPU engine and an AMX‑enabled CPU engine, allowing the CPU to independently batch and advance decodes while still cooperating with the GPU for dense stages. This design expands key‑value cache capacity into host memory and reduces bursty CPU progress, leading to significant throughput gains—up to 43.2 % over NEO and 90.6 % over vLLM—without increasing latency. The system also maintains low time‑to‑first‑token and supports higher request rates at comparable tail latency.

By YuXuan Lin, KeQiang Wu, Kingsum Chow
arXiv AI
Jun 2

Threshold-Based Exclusive Batching for LLM Inference

arXiv:2606. 00516v1 Announce Type: new Abstract: Mixed batching (MB)--interleaving prefill and decode in a single batch--has become the standard scheduling strategy for large language model (LLM) inference due to its efficiency in maximizing compute and memory utilization.

By Weifang Zhang, Yuzhou Nie, Bowen Pang, Guangrui Ma, Shining Wu
arXiv AI
Oct 9

Real Long-Term Memory for AI: A 50-Million-Token Window That Is Faster and Cheaper Than Recompute

The paper presents a memory layer called galahad-kv that stores the key-value state of a large language model’s context blocks (≈16,000 tokens each) on encrypted local NVMe disk, allowing byte‑exact retrieval without recomputation. On a single NVIDIA H100, the authors tested the system with Gemma 4 12B and 31B models over 50 million tokens of real public text, achieving 100 % successful reloads, 2.8×–4.3× faster loading than recomputation, and 8.8×–12.3× lower GPU energy usage while keeping GPU memory flat. The models answered long‑range factual queries with high accuracy (82 % for 12B, 98 % for 31B) and did not hallucinate, demonstrating that stored state can extend effective context without expanding the attention window.

By Sietse Schelpe