Ubuntu Manpage: fi_lpp - The LPP Fabric Provider

Provided by: libfabric-dev_2.1.0-1.1_amd64

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_COM‐
              PLETE

       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, how‐
ever 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 manage‐
ment 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 fea‐
tures 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 re‐
sources.

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

AUTHORS