Christophe, I can only test this on OS X 10.13.3 High Sierra, and it could differ from Maverick.
by default KA15-002:~ gilles$ ulimit -n 256 KA15-002:~ gilles$ ulimit -Hn unlimited but surprisingly, KA15-002:~ gilles$ ulimit -n unlimited -bash: ulimit: open files: cannot modify limit: Operation not permitted KA15-002:~ gilles$ ulimit -n 20000 -bash: ulimit: open files: cannot modify limit: Invalid argument and finally, a lower value works just fine. KA15-002:~ gilles$ ulimit -n 10000 as a consequence, opal_set_max_sys_limits fails in my environment. --oversubscribe is mandatory (since there are no 256 cores on my laptop), and then ulimit -n 10000; mpirun --oversubscribe -np 256 ./ring_c works just fine (fwiw, this is an example from Open MPI sources examples/ring_c.c) So first, I invite you to double check with ulimit -n that your system changes are effective. How did you build/install Open MPI ? The message seems to come from libevent, and Open MPI uses an embedded version of libevent. It is possible to use an external version at configure time. If you are using an external libevent, you might want to try rebuilding Open MPI with the embedded one. Cheers, Gilles On Wed, Feb 14, 2018 at 4:57 PM, Christophe Petit <christophe.peti...@gmail.com> wrote: > Hello, > > Using Open-Mpi 3.0 and following the tutorial on this link, I try to run a > MPI code under MacOS 10.9.5 (Mavericks) with a number of process equal to > 256 : the MPI code allocates for each process a 512x512 2D array, so it > requires 256*256kB = 64MB of total used memory. > > My MacOS has 16GB RAM and 8 cores, so it seems to be weird. > > For a number of process lower than 256 (I tried : np=2,4,8,16,32,64,128), > there is no problem, execution is good and I get expected results. > > But for np = 256, I get the following message which repeats itself : > > $ mpirun -np 256 ./explicitPar > > [warn] select: Invalid argument > [warn] select: Invalid argument > [warn] select: Invalid argument > ... > > I tried also to use -mca option by doing : > > $ mpirun -mca opal_set_max_sys_limits 1 -np 256 ./explicitPar > > But I get the same warning message. > > From this link cited above, I did : > > $ launchctl limit maxfiles > > maxfiles 65536 200000 > > Then, in root user, I created /etc/launchd.conf file and put into : > > limit maxfiles 65536 200000 > > I restarted the system for the new limits to take effect and type as normal > user : > > $ launchctl limit maxfiles > > maxfiles 65536 200000 > > But unfortunately, these modifications have no effects on the MPI function > "mpirun" with 256 processes and don't make disappear the warning above. > > On Linux platform, I can launch my MPI code with np = 256, without problem, > the issue is only happening on MacOS 10.9.5. > > I didn't get this issue with previous version of Open-MPI. > > Any idea ? Thanks > > > > _______________________________________________ > users mailing list > firstname.lastname@example.org > https://lists.open-mpi.org/mailman/listinfo/users _______________________________________________ users mailing list email@example.com https://lists.open-mpi.org/mailman/listinfo/users