Developer Reference

Environment Variables for Multi-EP

Intel® MPI Library Developer Guide for Windows*Linux* OS
This feature is supported for the
release_mt
and
debug_mt
library configurations only. To specify the configuration, run the following command:
$ source
<installdir>
/bin/vars.sh release_mt

PI_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.

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.
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
, 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
.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.