Developer Reference

  • 2020 Update 2
  • 07/15/2020
  • Public Content

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 <installdir>/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.
This knob works if
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

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804