cross-layer-sparse-attention-with-shared-routing-362201e4·1 events·first seen Aliases: Cross-Layer Sparse Attention with Shared Routing, You Only Index Once: Cross-Layer Sparse Attention with Shared Routing
Researchers propose Cross-Layer Sparse Attention (CLSA), a method that builds on KV-sharing architectures (like YOCO) to share both the KV cache and the routing index across decoder layers. A single indexer computes token-level top-k selection once and reuses it across layers, reducing routing overhead while preserving fine-grained selectivity. Experiments on short- and long-context benchmarks show up to 7.6x decoding speedup and 17.1x overall throughput improvement at 128K context, addressing pre-filling, KV-cache storage, and decoding bottlenecks simultaneously.