Hello,
Folowing the article http://software.intel.com/en-us/articles/using-intel-mkl-in-gnu-octave to compile and link mkl libs with Octave.
After installing Octave I've checked with "ldd /usr/local/bin/octave" that all mkl libraries are correctly linked.
- Then export the environment variables to enable MIC automatic offload:
Following the documentacion Setting Environment Variables for Automatic Offload
export MKL_MIC_ENABLE=1
- Finally I've executed Octave and run a simple matrix multiplication (3000x3000 matrix size, using DGEMM in BLAS mkl libraries). Using micsmc tool, we can see that no coprocessor core it's working, so the automatic offload isn't doing properly .
To ensure that Octave is using mkl dgemm function I've debugged the execution of a simple matrix multiplication. And as expected the function is correctly called: Breakpoint 2, 0x00007ffff1d67980 in dgemm_ () from /opt/intel/parallel_studio_xe_2013_update3/composer_xe_2013.3.163/mkl/lib/intel64/libmkl_intel_lp64.so
But all the work is done in host processor and Xeon Phi coprocessor doesn't do anything.
I've perform one more test using an example dgemm program:
Using the dgemm example included in <install-dir>/Samples/en-US/mkl/tutorials.zip -> dgemm_example.c. I modified the code to call dgemm function instead of cblas_dgemm, after compiling and linking it with mkl libraries after a first test, debugging the application and with environment variable MKL_MIC_ENABLE set to 1 we can see the following line:
0x00007ffff77ad980 in dgemm_ () from /opt/intel/parallel_studio_xe_2013_update3/composer_xe_2013.3.163/mkl/lib/intel64/libmkl_intel_lp64.so
So the simple program dgemm_example.c is calling exactly the same mkl function of libmkl_intel_lp64.so mkl library. And the execution is being perform in the coprocessor with no problem!
Can you give me some support to help us to understand why automatic offload is not working in Octave?
Thanks for the help.