Developer Reference

Environment Variables for Multi-EP

This feature is supported for the
release_mt
and
debug_mt
library configurations only. To specify the configuration, run the following command:
$ source <
install-dir
>/bin/vars.sh release_mt

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.

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
. 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
.

Product and Performance Information

1

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