Not precisely correct. It depends on the environment. If there is a resource manager allocating nodes, or you provide a hostfile that specifies the number of slots on the nodes, or you use -host, then we default to no-oversubscribe.
If you provide a hostfile that doesn’t specify slots, then we use the number of cores we find on each node, and we allow oversubscription. What is being described sounds like more of a bug than an intended feature. I’d need to know more about it, though, to be sure. Can you tell me how you are specifying this cpuset? > On Sep 15, 2015, at 4:44 PM, Matt Thompson <fort...@gmail.com> wrote: > > Looking at the Open MPI 1.10.0 man page: > > https://www.open-mpi.org/doc/v1.10/man1/mpirun.1.php > <https://www.open-mpi.org/doc/v1.10/man1/mpirun.1.php> > > it looks like perhaps -oversubscribe (which was an option) is now the default > behavior. Instead we have: > > -nooversubscribe, --nooversubscribe > Do not oversubscribe any nodes; error (without starting any processes) if the > requested number of processes would cause oversubscription. This option > implicitly sets "max_slots" equal to the "slots" value for each node. > > It also looks like -map-by has a way to implement it as well (see man page). > > Thanks for letting me/us know about this. On a system of mine I sort of > depend on the -nooversubscribe behavior! > > Matt > > > > On Tue, Sep 15, 2015 at 11:17 AM, Patrick Begou > <patrick.be...@legi.grenoble-inp.fr > <mailto:patrick.be...@legi.grenoble-inp.fr>> wrote: > Hi, > > I'm runing OpenMPI 1.10.0 built with Intel 2015 compilers on a Bullx System. > I've some troubles with the bind-to core option when using cpuset. > If the cpuset is less than all the cores of a cpu (ex: 4 cores allowed on a 8 > cores cpus) OpenMPI 1.10.0 allows to overload these cores until the maximum > number of cores of the cpu. > With this config and because the cpuset only allows 4 cores, I can reach 2 > processes/core if I use: > > mpirun -np 8 --bind-to core my_application > > OpenMPI 1.7.3 doesn't show the problem with the same situation: > mpirun -np 8 --bind-to-core my_application > returns: > A request was made to bind to that would result in binding more > processes than cpus on a resource > and that's okay of course. > > > Is there a way to avoid this oveloading with OpenMPI 1.10.0 ? > > Thanks > > Patrick > > -- > =================================================================== > | Equipe M.O.S.T. | | > | Patrick BEGOU | mailto:patrick.be...@grenoble-inp.fr > <mailto:patrick.be...@grenoble-inp.fr> | > | LEGI | | > | BP 53 X | Tel 04 76 82 51 35 | > | 38041 GRENOBLE CEDEX | Fax 04 76 82 52 71 | > =================================================================== > > _______________________________________________ > users mailing list > us...@open-mpi.org <mailto:us...@open-mpi.org> > Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/users > <http://www.open-mpi.org/mailman/listinfo.cgi/users> > Link to this post: > http://www.open-mpi.org/community/lists/users/2015/09/27575.php > <http://www.open-mpi.org/community/lists/users/2015/09/27575.php> > > > > -- > Matt Thompson > Man Among Men > Fulcrum of History > _______________________________________________ > users mailing list > us...@open-mpi.org > Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/users > Link to this post: > http://www.open-mpi.org/community/lists/users/2015/09/27579.php
