OpenMP incompatible with LAPACK & BLAS routines

I've written a few c mex files and have called dsyev to find eigenvalues etc. I want to call this routine in parallel in a threaded loop. Everything compiles OK without warnings (using MS Visual Studio Prof. Edition 2005).

However, when I call it from Matlab it just crashes, without any error messages...

Anyone have any ideas?!?

Thanks in advance

Adam

[James Tursa]

Well, I think your title already says it. The LAPACK and BLAS libraries that ship with MATLAB are probably not thread-safe. However, many of the routines in these libraries are already multi-threaded, so I don't know how much speed up you would get even if they were thread-safe.

[Adam connolly]

OK thanks anyway. Thing is, I'm calling them on loads of little matrices which are built in a loop, so want the loop to run in parallel. Think maybe a rewrite in straight c or fortran may be the way forward!

[James Tursa]

I should have asked this before, but are you sure your C code for calling dsyev is correct (argument type, etc)? Can you run it in a single thread to verify that it is coded correctly?

[zhuanyi]

Hi Adam, do you have any update? I am facing the same problem.

[James Tursa]

@zhuanyi Can you open a new Question, and maybe include a minimal complete example that reproduces the problem?

Answer 1

[Jill Reese]

Running your original mex function within a MATLAB Parallel Computing Toolbox parfor loop might give you the parallelism you want.