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Futhark explores efficient graph colouring without GPU execution

futhark-lang.org 7 min read Editor score 7/10

A sparse-Jacobian computation needs graph colouring, but its fast greedy distance-2 algorithm is inherently sequential; the post examines how to keep this work off the GPU. It illustrates trade-offs in parallel data-processing workloads.

What

Futhark's graph-colouring work combines sequential distance-2 colouring with massively parallel Jacobian computation.

How

The greedy colouring algorithm runs well on the sequential C backend but performs poorly on the GPU backend, where CPU code can trigger costly GPU-memory reads.

Why it matters

The example shows why engineers must account for memory placement and transfer overhead when mixing sequential and parallel workloads.

Read on futhark-lang.org → Lobsters

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