arXiv Machine Learning

EntroPrefill: Renyi-Guided Context Pruning with Conditional Stability Guarantees for Retrieval-Augmented Generation

EntroPrefill introduces a Renyi‑guided context pruning method for retrieval‑augmented generation, coupling a proposal mechanism with constraints on discarded attention mass. The approach includes a sink‑isolated, regularized head pooling strategy that balances specialization and worst‑head coverage, and derives a computable upper bound on token removal along with finite‑sample observer guarantees for adaptive pruning layers. The paper also establishes a conditional transformer perturbation bound with Lipschitz constants, a first‑token decision‑margin corollary, and a counterexample illustrating limits of shallow observations, while outlining a systems analysis that distinguishes query‑head unions, physical page allocation, and KV‑transfer payload to provide an arithmetic break‑even condition for pruning.

arXiv Machine Learning
Sep 23

Magnitude Profile Pruning: Calibration-Free Structured Attention Head Removal for Transformer Compression

Magnitude Profile Pruning introduces a training‑free, calibration‑free method for removing attention heads in Transformer models by statistically detecting outliers in weight row norms. Heads whose projection weights fall within the bulk of the distribution are pruned, while outlier heads are retained. Across several models, the MP‑G variant achieves superior perplexity at various sparsity levels and yields significant parameter and FLOP reductions without requiring forward passes, calibration data, or gradient computations.

By Kasun Dewage, Marianna Pensky, Heranga K. Rathnasekara, Suranadi De Silva
arXiv Machine Learning
Oct 15

Your Transformer Is Secretly Elastic

The paper presents a retraining‑free technique that transforms pre‑trained transformers into elastic models capable of adapting to any computational budget on the fly. By jointly ranking every MLP neuron and attention head on a common scale and applying soft pruning across multiple sparsity targets, the method achieves smooth performance degradation up to 60% sparsity while outperforming one‑shot baselines. Experiments on 27 vision and text transformer encoders show significant parameter reductions with minimal accuracy loss and notable throughput and latency gains on GPUs, all produced in minutes.

By Walter Simoncini, Dheeraj Varghese, Gertjan J. Burghouts, Cees G. M. Snoek
arXiv Machine Learning
Oct 5

Page-EntroKV: Hardware-Aligned, Entropy-Weighted KV-Cache Eviction under Grouped-Query Attention

Page-EntroKV is a new KV‑cache eviction framework designed for grouped‑query attention (GQA) in long‑context autoregressive language models. It pools token importance scores across query heads within each physical group using sink‑isolated Renyi‑2 entropy, then projects these pooled scores onto page frames and performs eviction at the hardware tuple level. The authors prove theoretical guarantees on union overhead, budget preservation, and needle‑retention, and demonstrate on a Qwen2.5‑1.5B‑Instruct pilot that Page‑EntroKV achieves exact union overhead control, eliminates sink masquerade, and retains 100% of critical tokens compared to mean‑pooling baselines.

By Inbasekaran S
arXiv AI
Sep 25

Near-Oracle KV Selection via Pre-hoc Sparsity for Long-Context Inference

The paper introduces Pre-hoc Sparsity (PrHS), a method that selects key-value (KV) cache entries before attention scoring to avoid posterior bias in large language model inference. By bounding mutual‑information loss through the dropped attention mass, PrHS offers explicit accuracy control and implements three orthogonal selectors across time, depth, and layer. Experiments on LLaMA and Mistral models show that PrHS cuts retrieval overhead by over 90%, achieves higher sparsity than HShare, and delivers significant speedups and reduced FLOPs on NVIDIA A100 GPUs while maintaining near‑dense accuracy.

By Yifei Gao, Lei Wang, Rong-Cheng Tu, Qixin Zhang, Jun Cheng, Dacheng Tao
arXiv Computation and Language
Oct 15

Joint Subspace Sparse Attention for Efficient Long-Context Decoding

Joint Subspace Sparse Attention (JSSA) is a new method that reduces KV‑cache traffic in long‑context LLM decoding by selecting tokens at the token level while preserving query–key structure. It learns a shared low‑dimensional query–key subspace through a tractable spectral solution and implements a gather‑free indexed‑attention kernel that supports per‑KV‑head selections. Across various attention architectures, JSSA maintains near full‑KV accuracy, avoids generation‑length inflation, and can achieve up to 6.43× decoding throughput on a single GPU for 128K context, even at 700B‑parameter scale.

By Jiwon Song, Yoongon Kim, Jae-Joon Kim