Re: Fwd: Perfromance problem running multiple copies of Octave on a multicore processor

[Mike Miller]

On Thu, Dec 10, 2015 at 23:37:58 +0000, Ian McCallion wrote:
> Regarding controlling the number of threads used by blas and lapack:
> -  I have looked for references to OMP_NUM_THREADS in documentation
> and found nothing.
> -  I have tried setting OMP_NUM_THREADS environment variable inside or
> outside octave to no effect.
> Have mechanisms for controlling the number of threads used by openMP
> been changed somewhere in Octave lapack blas and openMP?

No, it's via the environment variables documented for OpenBLAS, either
OMP_NUM_THREADS or OPENBLAS_NUM_THREADS.

I used

  >> setenv OMP_NUM_THREADS 1
  >> perf1(...)

to achieve the results I reported earlier.

-- 
mike