fi_rxm(7) Libfabric Programmer's Manual
NAME
The RxM (RDM over MSG) Utility Provider
OVERVIEW
The RxM provider (ofi_rxm) is an utility provider that supports RDM endpoint emulated over MSG endpoint of a core provider.
REQUIREMENTS
RxM provider requires the core provider to support the following features:
-
MSG endpoints (FI_EP_MSG)
-
Shared receive contexts (FI_SHARED_CONTEXT)
-
RMA read/write (FI_RMA)
-
FI_OPT_CM_DATA_SIZE of atleast 24 bytes
SUPPORTED FEATURES
The RxM provider currently supports FI_MSG, FI_TAGGED and FI_RMA capabilities.
- Endpoint types
- The provider supports only FI_EP_RDM.
- Endpoint capabilities
- The following data transfer interface is supported: FI_MSG, FI_TAGGED, FI_RMA.
- Progress
- The RxM provider supports only FI_PROGRESS_MANUAL for now.
- Addressing Formats
- FI_SOCKADDR, FI_SOCKADDR_IN
- Memory Region
- FI_MR_VIRT_ADDR, FI_MR_ALLOCATED, FI_MR_PROV_KEY MR mode bits would be required from the app in case the core provider requires it.
LIMITATIONS
When using RxM provider, some limitations from the underlying MSG provider could also show up. Please refer to the corresponding MSG provider man pages to find about those limitations.
Unsupported features
RxM provider does not support the following features:
-
op_flags: FI_CLAIM, FI_PEEK, FI_FENCE.
-
FI_ATOMIC
-
Scalable endpoints
-
Shared contexts
-
FABRIC_DIRECT
-
Multi recv
-
Counters
-
FI_MR_SCALABLE
-
Authorization keys
-
Application error data buffers
-
Multicast
-
FI_ADDR_STR, FI_SYNC_ERR
-
Reporting unknown source addr data as part of completions
-
Triggered operations
-
fi_cq_sread, fi_cq_sreadfrom and fi_cq_signal calls.
Usage limitations
RxM provider should work fine for client - server programs like fabtests. Support for MPI, SHMEM and other applications is work in progress.
RUNTIME PARAMETERS
No runtime parameters are currently defined.