Hi Tim, it helps, up to four processes. But it has two drawbacks. 1) Using more cores/threads than the machine provides (so the actual over-subscription) is still not possible. 2) it still requires an additional command line argument.
What I'd like to see is that a call of mpirun with an arbitrary number of processes that just works without any other command line options. However, an environment variable would be acceptable. MPICH's (v3.3) mpirun of a plain installation with no further configure options (I think it uses the Hydra PM) just does what I want, but MPICH is not always an option ;-) Regards, Steffen On 16/04/2019 14.56, Tim Jim wrote: > Hi Steffen, > > I'm not sure if this will help you (I'm by far no expert) but the > mailing group pointed by to using: > mpirun --use-hwthread-cpus > > to solve something similar. > > Kind regards, > Tim > > > On Tue, 16 Apr 2019 at 19:01, Steffen Christgau > <christ...@cs.uni-potsdam.de <mailto:christ...@cs.uni-potsdam.de>> wrote: > > Hi everyone, > > on my 2 cores/4 threads development platform I want to start programs > via mpirun with over-subscription enabled by default. I have some > external packages which have tests that use more than 2 processes. They > all fail because Open MPI refuses them to run due to over-subscription. > I know that I can enable over-subscription with mpirun --oversubscribe > and that works well, but that would require to modify the packages' > autotools files or the generated Makefiles with I found hardly > convenient. > > I also tried two of the RMAPS MCA parameters: > > - rmaps_base_no_oversubscribe > - rmaps_base_oversubscribe > > (btw, are they redundant? Having two of them and one is the negation of > the other is quite confusing. The description in ompi_info reads quite > similar for the two.) > > $ mpirun --mca rmaps_base_no_oversubscribe 0 --mca > rmaps_base_oversubscribe 1 -n 4 hostname > -------------------------------------------------------------------------- > There are not enough slots available in the system to satisfy the 4 > slots that were requested by the application: > hostname > > Either request fewer slots for your application, or make more slots > available for use. > -------------------------------------------------------------------------- > > Setting the environment variables (OMPI_MCA_rmaps_...) did not help > either. The same goes or the FAQ [1]: > > $ cat > my-hostfile > localhost > $ mpirun -np 4 --hostfile my-hostfile hostname > -------------------------------------------------------------------------- > There are not enough slots available in the system to satisfy the 4 > slots... > > My Open MPI installation is a private build of version 4.0.0, configured > with nothing more than ./configure --prefix=/some/where > --enable-mpi-fortran > > How can I allow over-subscription by default? I am aware about > performance implications, but it's only used for testing and > development. I am not using a resource manager on that machine. > > Thanks in advance > > Regards, Steffen > > [1] https://www.open-mpi.org/faq/?category=running#oversubscribing > > _______________________________________________ > users mailing list > users@lists.open-mpi.org <mailto:users@lists.open-mpi.org> > https://lists.open-mpi.org/mailman/listinfo/users > > > > -- > > > > *Timothy Jim > */PhD Researcher in Aerospace/ > > Creative Flow Research Division, > Institute of Fluid Science, Tohoku University > > www.linkedin.com/in/timjim/ <http://www.linkedin.com/in/timjim/> > > > _______________________________________________ > users mailing list > users@lists.open-mpi.org > https://lists.open-mpi.org/mailman/listinfo/users > _______________________________________________ users mailing list users@lists.open-mpi.org https://lists.open-mpi.org/mailman/listinfo/users
