On Wed, 4 Mar 2009, Lex Kemper wrote: LK> Out of curiosity, what behaviour do you see from MKL that it doesn't LK> obey OMP_NUM_THREADS? I ask, because that's what I'm using, and would LK> like to make sure it's behaving right.
lex, it doubt it is mkl that is to blame, but rather the mpirun script/wrapper not exporting environment variables to all tasks, even on remote nodes. if you have a good sysadmin running your machine her or she will have already set OMP_NUM_THREADS=1 in the default environment. with openmpi, for example, the environment is not exported unless explicitly set it via a flag. linking the sequential version of mkl (see mkl docs for) details, is the solution for paranoid people (like me). cheers, axel. LK> LK> Thanks, LK> LK> Lex Kemper LK> University of Florida LK> LK> Axel Kohlmeyer wrote: LK> > On Wed, 4 Mar 2009, JR Schmidt wrote: LK> > LK> > JRS> I had problems with MKL not obeyig OMP_NUM_THREADS. I found it was LK> > JRS> easier to simply link with the MKL serial (non-threaded) library, since LK> > JRS> that is what you want anyway. LK> > LK> > yes. but in carlo's case it _does_ work correctly. LK> > LK> > axel. LK> > LK> > JRS> > I tried to run the example01 with the following settings: LK> > JRS> > LK> > JRS> > OMP_NUM_THREADS=1 LK> > JRS> > mpiexec -n 8 LK> > JRS> > LK> > JRS> > The example is executed, but with a very long time. All 8 LK> > JRS> > CPUs are running LK> > JRS> > LK> > JRS> LK> > LK> _______________________________________________ LK> Pw_forum mailing list LK> Pw_forum at pwscf.org LK> http://www.democritos.it/mailman/listinfo/pw_forum LK> -- ======================================================================= Axel Kohlmeyer akohlmey at cmm.chem.upenn.edu http://www.cmm.upenn.edu Center for Molecular Modeling -- University of Pennsylvania Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323 tel: 1-215-898-1582, fax: 1-215-573-6233, office-tel: 1-215-898-5425 ======================================================================= If you make something idiot-proof, the universe creates a better idiot.
