Expand description
DeploymentPlacementActor — picks nodes for new deployments. Doc §7.2.
Reads transport_kind() to decide whether the deployment needs a
GPU node (LocalGpu) or any egress-capable node
(RemoteNetwork { provider }). This actor operates at the
deployment → node level; once a node is chosen for a LocalGpu
deployment, the which-GPU-on-this-node decision is delegated to
the upstream rakka_accel::cuda::placement::PlacementActor (under the
local-gpu feature). Renamed from the doc’s plain PlacementActor
to make the abstraction-level distinction visible at the call site.
Without the local-gpu feature this actor still runs but the GPU
ordinals it returns are a naïve 0..gpus_per_replica slice — fine
for remote-only builds and for tests that don’t actually allocate
CUDA contexts. Operators wanting topology-aware GPU choice (NVLink
islands, MIG slicing, etc.) enable the feature and the
deployment-level placement starts asking the upstream actor for
per-node device choices.