Duane Merrill (NVIDIA) - GPU Technology Conference

2) Poor load balancing within SIMD lanesProblem:Solution:Large variance in adjacency listsizesExacerbated by wide SIMD widthsCooperative neighbor expansionEnlist nearby threads to helpprocess each adjacency list inparallela) Bad: Serial expansion & processingt 1 t 3t 0 t 2b) Slightly better: Coarse warp-centric parallel expansion…t 0 t 1 t 2 t 3 t 4 t 5 t 31…t 32 t 33 t 34 t 35 t 36 t 37 t 63…t 64 t 65 t 66 t 67 t 68 t 69 t 95c) Best: Fine-grained parallel expansion (packed by prefix sum)t 0 t 1 t 2 t 3 t 4 t 531