PetscBLASSetNumThreads#

set the number of threads for calls to BLAS to use

Synopsis#

#include "petscsys.h"   
PetscErrorCode PetscBLASSetNumThreads(PetscInt nt)

Input Parameter#

  • nt - the number of threads

Options Database Key#

  • -blas_num_threads - set the number of threads when PETSc is initialized

Notes#

The environmental variables BLIS_NUM_THREADS, MKL_NUM_THREADS, or OPENBLAS_NUM_THREADS, OMP_NUM_THREADS may also affect the number of threads used depending on the BLAS libraries being used. A call to this function overwrites those values.

With the BLIS BLAS implementation one can use BLIS_THREAD_IMPL=pthread or BLIS_THREAD_IMPL=openmp to determine how BLIS implements the parallelism.

See Also#

PetscInitialize(), PetscBLASGetNumThreads()

Level#

intermediate

Location#

src/sys/objects/version.c

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