Source: cccl_upstream/cub/cub/device/dispatch/dispatch_transform.cuh
Target: vllm/model_executor/layers/activation.py
CCCL system design applied:
- dispatch_transform.cuh CacheAsyncConfiguration: cache occupancy/config
results across calls to avoid recomputation
- Applied: cache output tensor when shape/dtype/device unchanged
- BI-V100 has no async allocator → cudaMalloc is synchronous → caching
avoids blocking the stream on every decode step
- spread_out_items_per_thread: dynamic tile adjustment for occupancy
→ we only cache for stable decode shapes, not variable prefill