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From: Arne Schneck <arne.schneck@math.uni-karlsruhe.de>
Newsgroups: comp.soft-sys.matlab
Subject: GOTO BLAS and multiple threads
Date: Tue, 12 Aug 2008 19:00:35 +0200
Organization: University of Karlsruhe, Germany
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Hi there,

I've been trying to use GOTO BLAS instead of the BLAS implementation that
comes with Matlab. The problem is that when I compile a C file (with mex)
that uses one of the BLAS routines from the GOTO library (dsyrk in my
case), it only uses 1 thread.

Things I've tried:
- Setting OMP_NUM_THREADS and GOTO_NUM_THREADS to 8 => GOTO BLAS still only
uses one thread when called from a C MEX file.
- When I call dsyrk from a little command-line C program (and not from a C
MEX file), it correctly uses 8 threads. (And then it's almost 3 times
faster than the standard MATLAB call A*A'!)
- Linking against mwblas => 8 threads used. Linking against goto => only 1
thread used.

Any idea how to get GOTO BLAS to use 8 threads?

Arne