Crate metrale_gpu_sys 

2026-09-26: Low-level bindings: the RDMA verbs C shim with its rail handshake and wire codecs, NCCL (feature nccl), NVML and cuFile loaded with dlopen, and NVTX ranges (feature nvtx).

verbs and railset are compiled only under cfg(metrale_rdma_verbs), which build.rs emits when it compiles the shim. env, handshake and wire are always compiled, so their tests run without rdma-core.

Owner: metrale-gpu-sys. Invariants: none beyond the types.

Re-exports

pub use wire::CacheServerParams;

pub use wire::MODE_TCP;

pub use wire::MODE_VERBS;

pub use wire::RemoteQp;

pub use wire::STATUS_ERR;

pub use wire::STATUS_OK;

pub use wire::VerbsClientParams;

pub use wire::VerbsServerParams;

Modules

cufile

2026-09-26: cuFile (GPUDirect Storage) entry points, resolved from libcufile with dlopen, so a binary starts on a host without the library and CuFile::load reports the failure instead. metrale-storage’s GDS probe and bench call them; docs/adr/0008-nvme-high-speed-swap.md records why the swap path does not use GDS on GB10.

env

2026-09-26: Environment lookups over a key list the caller passes: the RDMA clients read their device names, GID indices and depths through these. No key or fallback chain is fixed here.

handshake

2026-09-26: The client side of the rail handshake as byte functions over Read/Write that take QP identities as (qpn, psn, gid) tuples, so they need no Verbs. railset::RailSet calls them; tests/transcript_golden.rs drives them against a scripted peer.

nccl

2026-09-26: Raw NCCL bindings used by metrale-comm, plus the CUDA driver stream and event calls it needs. The function declarations follow the installed nccl.h (2.29.7); NcclConfig does not (see its doc).

nvml

2026-09-26: NVML (the NVIDIA management library), resolved with dlopen.

wire

2026-09-26: RDMA handshake wire codecs, used by the RDMA clients and re-exported by the storage peer daemons, so both ends share one codec.

Functions

verbs_enabled

2026-09-26: Whether build.rs compiled the verbs shim, i.e. whether cfg(metrale_rdma_verbs) is set. Always compiled, so tests can assert it (tests/verbs_probe.rs, metrale-storage’s rdma_verbs_probe_tests.rs).