Intel® MPI Library Developer Reference for Linux* OS

ID 768732
Date 3/22/2024
Public

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Document Table of Contents

Environment Variables for Multi-EP

I_MPI_THREAD_SPLIT

Syntax

I_MPI_THREAD_SPLIT=<value>

Arguments

Value Binary Indicator
0 | no | off | disable Disable the MPI_THREAD_SPLIT model support. This is the default value.
1 | yes | on | enable Enable the MPI_THREAD_SPLIT model support.

Description

Use this environment variable to control the I_MPI_THREAD_SPLIT programming model.

For more information on MPI_THREAD_SPLIT, refer to the Intel® MPI Library Developer Guide, section MPI_THREAD_SPLIT Programming Model.

I_MPI_THREAD_RUNTIME

Syntax

I_MPI_THREAD_RUNTIME=<value>

Arguments

Value Thread Runtime
generic Enable runtime support (for example, pthreads, TBB). This is the default value if OpenMP* cannot be detected at runtime.
openmp Enable OpenMP runtime support. This is the default value if OpenMP is detected at runtime.

Description

Use this environment variable to control threading runtime support.

NOTE:
I_MPI_THREAD_SPLIT model support is enabled.

I_MPI_THREAD_MAX

Syntax

I_MPI_THREAD_MAX=<int>

Arguments

<int> The maximum number of threads per rank. The default value is omp_get_max_threads() if I_MPI_THREAD_RUNTIME is set to openmp. The value is 1 otherwise

Description

Use this environment variable to set the maximum number of threads to be used in each process concurrently.

I_MPI_THREAD_ID_KEY

Syntax

I_MPI_THREAD_ID_KEY=<string>

Arguments

<string> Define the MPI info object key. The default value is thread_id

Description

Use this environment variable to set the MPI info object key that is used to explicitly define the logical thread number thread_id.