Developer Reference

  • 2021.1
  • 12/04/2020
  • Public Content
Contents

mkl_domain_set_num_threads

Specifies the number of OpenMP* threads for a particular function domain.

Syntax

int
mkl_domain_set_num_threads
(
int
nt
,
int
domain
);
Include Files
  • mkl.h
Input Parameters
Name
Type
Description
nt
int
nt
> 0 - The number of threads suggested by the user.
nt
= 0 - The default number of threads for the OpenMP run-time library.
nt
< 0 - Invalid value, which is ignored.
domain
int
The named constant that defines the targeted domain.
Description
This function specifies how many OpenMP threads a particular function domain of
Intel® oneAPI Math Kernel Library
should use. If this number is not set (default) or if it is set to zero in a call to this function,
Intel® oneAPI Math Kernel Library
uses the default number of threads for the OpenMP run-time library. The number of threads specified applies to the specified function domain on all execution threads except the threads where the number of threads is set withmkl_set_num_threads_local. For a list of supported values of the
domain
argument, see Table "Intel MKL Function Domains".
The number of threads specified is only a hint, and
Intel® oneAPI Math Kernel Library
may actually use a smaller number.
This function takes precedence over the
MKL_DOMAIN_NUM_THREADS
environment variable.
Return Values
Name
Type
Description
ierr
int
1 - Indicates no error, execution is successful.
0 - Indicates a failure, possibly because of invalid input parameters.

Example

#include "mkl.h" … mkl_domain_set_num_threads(4, MKL_DOMAIN_BLAS); my_compute_using_mkl_blas(); // Intel MKL BLAS functions use up to 4 threads my_compute_using_mkl_dft(); // Intel MKL FFT functions use the default number of threads

Product and Performance Information

1

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