I usually switch between blas versions using sudo update-alternatives .... However, I need to get it to work without sudo. I have tried several options, but none seem to work.
I have the following FORTRAN code to test if I have successfully switched libraries
PROGRAM BLASTEST
IMPLICIT NONE
CALL MKL_Set_Num_Threads(1)
CALL openblas_set_num_threads(1)
END PROGRAM BLASTEST
I have intel MKL set as the preferred alternative, so when I compile using the following command, it results in an error that openblas_set_num_threads cannot be found.
gfortran -o test test.f -lblas
I have tried the following methods to get it to link with openblas instead, but it keeps linking with MKL:
Create a symbolic link from ~/.local/alternatives/libblas.so.3-x86_64-linux-gnu to /usr/lib/x86_64-linux-gnu/openblas/libblas.so.3 and add ~/.local/alternatives to LD_LIBRARY_PATH
Same method as before, but also add it to LIBRARY_PATH
Compile using the following command gfortran -o test test.f -L/usr/lib/x86_64-linux-gnu/openblas/libblas.so.3 -lblas
Any help would be greatly appreciated
Override BLAS with LD_LIBRARY_PATH
Set openblas before "Intel MKL Blas" in the search path:
The common method is simply to set "the preferred" first in the LD_LIBRARY_PATH when compiling :
export LD_LIBRARY_PATH=/usr/lib/x86_64-linux-gnu/openblas:$LD_LIBRARY_PATH && [other command]