Adds a parallel warmup-gpu task that runs concurrently with
ensure-binary. The warmup pod is a tiny CPU-only alpine container
scheduled on the gpu-pool's nodeSelector — its presence triggers
cluster-autoscaler scale-up of the L40S pool. After a 30s sleep, the
warmup pod exits; the node enters Scaleway's scaledown grace window
(~10 min), so the train pod lands on a hot node without waiting for
autoscaler provisioning.
No GPU resource request on the warmup pod — that would serialise
warmup and train on the same GPU. nodeSelector + nvidia.com/gpu
toleration are sufficient to force placement on the L40S pool.
Expected savings: ~3-5 min per cold cluster submission. First run
(this session, alpha-perception-4vl7c) showed compile took 113s
(sccache warm) with serial GPU provisioning following; subsequent
submissions should overlap the two stages.
DAG topology:
ensure-binary ──┐
├──> train
warmup-gpu ────┘ (only depends on ensure-binary; warmup is
fire-and-forget infrastructure)
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
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