Enhuai Liu

LoSA: Near-Lossless Sparse Attention for Training-Free Video Diffusion Acceleration

LoSA is a training-free sparse-attention method that fixes a retained-mass threshold of 99% rather than a sparsity ratio: it measures exact block attention masses at one early dense step, keeps, for each head and query block, the smallest key/value block set meeting the threshold, and reuses the frozen block indices for all remaining steps.