Intel® MPI Library

Developer Reference for Windows* OS

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ID 768734
Date 10/31/2024
Public
Document Table of Contents
Document Table of Contents x
Developer Reference for Windows* OS
Developer Reference for Windows* OS x
Introduction Command Reference Environment Variable Reference Notices and Disclaimers
Introduction x
Introducing Intel® MPI Library Notational Conventions Related Information User Authorization
Command Reference x
Compiler Commands mpiexec.hydra cpuinfo impi_info
Compiler Commands x
Compilation Command Options
mpiexec.hydra x
Global Hydra Options Local Hydra Options
Environment Variable Reference x
Compilation Environment Variables Hydra Environment Variables I_MPI_ADJUST Family Environment Variables Tuning Environment Variables Main Thread Pinning Environment Variables for Fabrics Control Environment Variables for Memory Policy Control Other Environment Variables
Tuning Environment Variables x
Autotuning
Autotuning x
I_MPI_TUNING_AUTO Family Environment Variables
Main Thread Pinning x
Environment Variables for Main Thread Pinning Interoperability with OpenMP* API
Environment Variables for Fabrics Control x
Communication Fabrics Control Shared Memory Control OFI*-capable Network Fabrics Control I_MPI_OFI_DRECV I_MPI_OFI_MATCH_COMPLETE I_MPI_OFI_LIBRARY_INTERNAL Example I_MPI_OFI_TAG_DYNAMIC
Developer Reference for Windows* OS

OFI*-capable Network Fabrics Control

I_MPI_OFI_DRECV

Control the capability of the direct receive in the OFI fabric.

Syntax

I_MPI_OFI_DRECV=<arg>

Arguments

<arg> Binary indicator
enable | yes | on | 1 Enable direct receive. This is the default value
disable | no | off | 0 Disable direct receive

Description

Use the direct receive capability to block MPI_Recv calls only. Before using the direct receive capability, ensure that you use it for single-threaded MPI applications and check if you have selected OFI as the network fabric by setting I_MPI_FABRICS=ofi.

I_MPI_OFI_MATCH_COMPLETE

Control the capability of the match complete in the OFI fabric for all providers if applicable.

Syntax

I_MPI_OFI_MATCH_COMPLETE=<arg>

Arguments

<arg> Binary indicator
enable | yes | on | 1 Enable match complete if applicable. This is the default value
disable | no | off | 0 Disable match complete

I_MPI_OFI_LIBRARY_INTERNAL

Control the usage of libfabric* shipped with the Intel® MPI Library.

Syntax

I_MPI_OFI_LIBRARY_INTERNAL=<arg>

Arguments

<arg> Binary indicator
enable | yes | on | 1 Use libfabric from the Intel MPI Library
disable | no | off | 0 Do not use libfabric from the Intel MPI Library

Description

Set this environment variable to disable or enable usage of libfabric from the Intel MPI Library. The variable must be set before sourcing the vars.bat script.

Example

> set I_MPI_OFI_LIBRARY_INTERNAL=1
> call <installdir> \env\vars.bat

Setting this variable is equivalent to passing the -ofi_internal option to the vars.bat script.

For more information, refer to the Intel® MPI Library Developer Guide, section Libfabric* Support.

I_MPI_OFI_TAG_DYNAMIC

Enable dynamic tag partitioning.

Syntax

I_MPI_OFI_TAG_DYNAMIC=<arg>

Arguments

<arg> Binary indicator
enable | yes | on | 1 Enable automatic OFI tag partitioning
disable | no | off | 0 Use static OFI tag layout. This is the default value

Description

Set this environment variable to enable dynamic OFI Netmod tag partitioning based on the run configuration. You can use it to get larger MPI tag space or to improve scalability in large-scale runs.

Parent topic: Environment Variables for Fabrics Control
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