PagedWeight is a system for efficient Mixture-of-Experts (MoE) LLM serving using dynamic, quality-aware weight quantization and intelligent memory management.
TL;DR
PagedWeight optimizes the serving of MoE LLMs by implementing a dynamic quantization strategy that adapts to runtime memory pressure. It balances hardware efficiency with model accuracy by monitoring expert routing statistics and prompt-specific sensitivities.
The PagedWeight system addresses the challenges of serving Mixture-of-Experts (MoE) Large Language Models by introducing a granular, quality-aware weight quantization framework. At its core, the system utilizes a 'weight page table' that manages linear-blocks at the level of individual experts and layer types. This allows for fine-grained control over bitwidth transitions, enabling the system to move weight pages between CPU and GPU memory based on real-time demand. The architecture is designed to mitigate the impact of quantization on model accuracy through a sophisticated runtime planner. This planner evaluates potential quantization actions by synthesizing three distinct data streams: offline global sensitivity scores, online routing statistics that identify 'hot' experts to prevent their degradation, and prompt residuals that provide input-specific corrections to accuracy estimates. By monitoring KV-cache pressure, the system can proactively trigger bitwidth reductions or weight offloading to maintain stability. When memory pressure is high, the planner uses a greedy selection process to meet target byte budgets while minimizing 'global damage' to the model's predictive capabilities. Ultimately, PagedWeight provides a robust mechanism for maintaining high throughput and low latency in LLM inference without sacrificing the structural integrity of the MoE architecture.
The paper introduces BadWAM, a framework for identifying and executing 'World-Action Drift Attacks' that exploit the desynchronization between a robot's predicted future and its executed actions.
TL;DR
Researchers have uncovered a critical vulnerability in World-Action Models (WAMs) where adversarial visual perturbations can decouple a robot's predicted future from its actual movements. This 'World-Action Drift Attack' allows an attacker to hijack robot actions while leaving the model's imagined future appearing visually plausible and safe.
The emergence of World-Action Models (WAMs) in robotics promises enhanced safety by allowing robots to predict and verify the consequences of their actions through 'imagined' futures. However, this research introduces 'BadWAM,' a framework that demonstrates how these models are susceptible to a unique class of adversarial attacks known as World-Action Drift Attacks. Unlike standard attacks that target classification accuracy, BadWAM exploits the interface between action generation and world prediction. The researchers identify two primary attack vectors: the 'action-only' attack, which focuses on maximizing task failure by driving the model toward incorrect controls, and the 'imagination-preserving' attack, a stealthier method where the robot continues to predict a plausible future even though its executed actions have been diverted from that path. Experimental results on the LIBERO and RoboTwin benchmarks reveal significant risks, with one attack reducing task success rates from over 96% to approximately 43%. The study concludes that because the model's predicted future remains visually consistent with a successful outcome, traditional safety mechanisms that rely on inspecting imagined trajectories may fail to detect these desynchronized, malicious actions.
The paper introduces On-Policy Delta Distillation (OPD2), a new reinforcement learning post-training method that uses the 'delta signal'—the difference between a teacher model and its base model—to more effectively transfer reasoning capabilities.
TL;DR
This research presents OPD2, a novel distillation technique that focuses on the learning trajectory of reasoning models by using a delta signal between teacher and base models. Experimental results prove it outperforms standard on-policy distillation across multiple complex reasoning domains.
The paper addresses the challenges in post-training Large Language Models (LLMs), specifically focusing on improving On-Policy Distillation (OPD). Traditional OPD methods attempt to make student models follow a teacher model's output distribution, but this often fails to isolate the specific reasoning capabilities acquired during the teacher's instruction tuning phase. To solve this, the authors propose On-Policy Delta Distillation (OPD2). The core innovation is the 'delta signal,' which is defined as the difference in probability between the reasoning-tuned teacher model and its original base model. By focusing on this delta, the student model learns the specific knowledge gains achieved during tuning rather than just mimicking the teacher's general linguistic style. To make this method computationally viable and stable, the researchers introduced two key reward design elements: 'centering,' which subtracts expected rewards to handle signal directionality, and 'joint conditioning' to address convergence issues. The effectiveness of OPD2 was tested using a mixed-domain training set covering Math, Science, and Code, evaluated against various model sizes including Qwen3 and Gemma-4. The empirical results demonstrate that OPD2 consistently outperforms conventional distillation methods across all tested benchmarks, providing a more efficient way to transfer complex reasoning abilities to smaller models.
The paper introduces Self Gradient Forcing (SGF), a new training strategy designed to improve long-form video extrapolation in autoregressive diffusion models by addressing the historical context-gradient gap.
TL;DR
The researchers present Self Gradient Forcing (SGF) to solve the lack of gradient flow in historical KV caches during autoregressive video generation. This method enables much more stable and consistent long-form video extrapolation without the massive memory overhead of full backpropagation.
In the field of autoregressive video diffusion, maintaining consistency over long durations is a significant challenge. Current 'Self Forcing' methods attempt to bridge the gap between training and inference by using self-generated histories, but they suffer from a 'historical context-gradient gap.' This occurs because the historical key-value (KV) cache is treated as frozen during future steps, meaning losses applied to new frames cannot supervise how the model originally wrote information into that cache. Consequently, visual elements like subject identity and background layout tend to drift or break during long rollouts. To solve this, the authors propose Self Gradient Forcing (SGF). SGF utilizes a two-pass training approach: the first pass performs a standard no-gradient rollout to record necessary states, and the second pass recomputes specific segments in parallel to allow gradients to flow back into the context-writing process. This allows for effective memory-writing supervision without the impossible computational burden of maintaining an entire serial autograd graph. Experimental results show that SGF drastically improves temporal stability and identity preservation, allowing models trained on very short 5-second clips to generate coherent videos lasting several minutes.
The paper introduces a new framework for evaluating and optimizing document set selection in RAG systems by moving beyond simple relevance to focus on inter-document interactions like redundancy and conflict.
TL;DR
This research presents a novel approach to document retrieval that prioritizes the holistic quality of document sets over individual document relevance. By introducing the SetwiseEvalKit benchmark and the Rubric4Setwise optimization method, the authors demonstrate how addressing redundancy and factual conflicts can significantly improve LLM generation performance.
In the evolving landscape of Retrieval-Augmented Generation (RAG), the focus of information retrieval is shifting from human browsing to providing context for Large Language Models (LLMs). The authors argue that traditional relevance-centric metrics, such as nDCG, are insufficient because they ignore how documents interact within a set. A collection of highly relevant documents can still be detrimental to an LLM if it contains redundant information, factual conflicts, or gaps in evidence. To address this, the paper proposes an 'evaluate-diagnante-optimize' framework. First, the authors present SetwiseEvalKit, a comprehensive benchmark featuring 28,000 high-quality evaluation rubrics across nine dimensions and three levels of granularity. Their analysis of 12 different rerankers shows that existing models perform poorly on cross-document coordination tasks, often failing to meet even 45% coverage of the new rubric dimensions. Second, they introduce Rubric4Setwise, a training-free method that utilizes these rubrics as signals for document selection. This approach optimizes for a balanced set of documents, effectively reducing context window waste and minimizing the need for additional search rounds. The results indicate that by optimizing for rubric-based criteria rather than just relevance, downstream generation quality is significantly enhanced.