flashinfer.comm.probe_pcie_ipc_rank_topology

flashinfer.comm.probe_pcie_ipc_rank_topology(rank: int, device: device | None = None) → PcieIpcRankTopology

Probe whether this rank’s GPU shares a PCIe switch with any peer.

Never raises: any failure is recorded in probe_error and the decision layer treats an unknown topology conservatively.

Only the GPU this rank owns is probed against the other visible GPUs, so a job pinned to a subset of the machine describes that subset rather than the whole host. That matters on a mixed box where one island sits behind a switch and another does not.