Intel® Math Kernel Library 2019 Developer Reference - C

mkl_set_num_threads

Specifies the number of OpenMP* threads to use.

Syntax

void mkl_set_num_threads( int nt );

Include Files

Input Parameters

Name

Type

Description

nt

int

nt > 0 - The number of threads suggested by the user.

nt 0 - Invalid value, which is ignored.

Description

This function enables you to specify how many OpenMP threads Intel MKL should use for internal parallel regions. If this number is not set (default), Intel MKL functions use the default number of threads for the OpenMP run-time library. The specified number of threads applies:

The number specified is a hint, and Intel MKL may actually use a smaller number.

Note

This function takes precedence over the MKL_NUM_THREADS environment variable.

Example

#include "mkl.h"
…
mkl_set_num_threads(4);
my_compute_using_mkl();	// Intel MKL uses up to 4 OpenMP threads