Intel® Math Kernel Library 2018 Developer Reference - C
In some situations you may need to limit the number of threads that the DftiComputeForward and DftiComputeBackward functions use. For example, if more than one thread calls Intel MKL, it might be important that the thread calling these functions does not oversubscribe computing resources (CPU cores). Similarly, a known limit of the maximum number of threads to be used in computations might help the DftiCommitDescriptor function to select a more optimal computation method.
Set the parameter DFTI_THREAD_LIMIT as follows:
On an attempt to set a negative value, the DftiSetValue function returns an error and does not update the descriptor.
The value of the DFTI_THREAD_LIMIT configuration parameter returned by the DftiGetValue function is defined as follows:
Commit Status |
Value |
---|---|
Not committed |
The value of DFTI_THREAD_LIMIT set in a previous call to the DftiSetValue function or the default value |
Committed |
The upper limit on the number of threads used by the DftiComputeForward and DftiComputeBackward functions |
To better understand usage of the DFTI_THREAD_LIMIT configuration parameter, refer to the following example in your Intel MKL directory: