fi_lpp(7)                      Libfabric v2.0.0                      fi_lpp(7)

NAME
       fi_lpp - The LPP Fabric Provider

OVERVIEW
       The LPP provider runs on FabreX PCIe networks.  FabreX provides high
       performance RDMA capabilities which form the foundation of the LPP
       provider.  Higher level primitives are implemented at the libfabric and
       LPP kernel module (KLPP) layers.

SUPPORTED FEATURES
       The LPP provider supports a subset of the libfabric API.  Key features
       include:

       Endpoint types
              LPP supports the FI_EP_RDM endpoint type with resource
              management.

       Endpoint capabilities
              LPP supports FI_MSG, FI_RMA, and FI_TAGGED message types.

       Additional capabilities
              LPP supports the additional features: FI_DIRECTED_RECV,
              FI_MULTI_RECV, FI_INJECT, FI_DELIVERY_COMPLETE

       Progress
              LPP currently supports only FI_PROGRESS_MANUAL.  Therefore user
              applications are required to poll for progress.

LIMITATIONS
       These features are unsupported: connection management, event queue,
       scalable endpoint, passive endpoint, shared receive context, atomics.

RUNTIME PARAMETERS
       The LPP provider checks for the following environment variables -

       FI_LPP_DISABLE_OSBYPASS
              A bool which disables direct userspace writes when set.  This
              can be used as a debugging aid, however it will degrade
              performance.

       FI_LPP_MAX_WR_OSBYPASS_SIZE
              Sets the maximum size for PIO when performing write RDMA
              transfers.  Transfers at or below this size will use CPU copy,
              while transfers above it will use a DMA engine.

       FI_LPP_MAX_RD_OSBYPASS_SIZE
              Sets the maximum size for PIO when performing read RDMA
              transfers.  Transfers at or below this size will use CPU copy,
              while transfers above it will use a DMA engine.

       FI_LPP_CQ_OVERCOMMIT
              A bool which allows operations to start that may overrun the CQ.
              Normally, when resource management is enabled, the LPP provider
              will attempt to throttle operations that might overrun the CQ.
              This parameter disables that behavior while leaving the
              remainder of the resource management features enabled.

       FI_LPP_DOMAIN_CLEANUP
              A bool which controls whether closing a domain with active
              resources will cause those resources to be automatically closed.
              If true (the default), the LPP provider will automatically close
              the resources.

       FI_LPP_SYSTEM_MEMCPY
              Use the memcpy implementation in the system libc rather than
              provider-specific memcpy.

SEE ALSO
       fabric(7), fi_provider(7), fi_getinfo(3)

AUTHORS
       OpenFabrics.

Libfabric Programmer's Manual     2024-12-11                         fi_lpp(7)