Le Wednesday 28 July 2010 11:34:13 Ralph Castain, vous avez écrit : > On Jul 27, 2010, at 11:18 PM, Yves Caniou wrote: > > Le Wednesday 28 July 2010 06:03:21 Nysal Jan, vous avez écrit : > >> OMPI_COMM_WORLD_RANK can be used to get the MPI rank. For other > >> environment variables - > >> http://www.open-mpi.org/faq/?category=running#mpi-environmental-variable > >>s > > > > Are processes affected to nodes sequentially, so that I can get the NODE > > number from $OMPI_COMM_WORLD_RANK modulo the number of proc per node? > > By default, yes. However, you can select alternative mapping methods. > > Or...you could just use the mpirun cmd line option to report the binding of > each process as it is started :-) > > Do "mpirun -h" to see all the options. The one you want is > --report-bindings
It reports to stderr, so the $OMPI_COMM_WORLD_RANK modulo the number of proc per nodes seems more appropriate for what I need, right? So is the following valid to put memory affinity? script.sh: MYRANK=$OMPI_COMM_WORLD_RANK MYVAL=$(expr $MYRANK / 4) NODE=$(expr $MYVAL % 4) numactl --cpunodebind=$NODE --membind=$NODE $@ mpiexec ./script.sh -n 128 myappli myparam > >> For processor affinity see this FAQ entry - > >> http://www.open-mpi.org/faq/?category=all#using-paffinity > > > > Thank you, but that's where I had the information that I put in my > > previous mail, so it doesn't answer to my question. > > Memory affinity is taken care of under-the-covers when paffinity is active. > No other options are required. Which is better: using this option, or the cmd line with numactl (if it works)? What is the difference? Tkx. .Yves. > > .Yves. > > > >> --Nysal > >> > >> On Wed, Jul 28, 2010 at 9:04 AM, Yves Caniou <yves.can...@ens-lyon.fr>wrote: > >>> Hi, > >>> > >>> I have some performance issue on a parallel machine composed of nodes > >>> of 16 procs each. The application is launched on multiple of 16 procs > >>> for given numbers of nodes. > >>> I was told by people using MX MPI with this machine to attach a script > >>> to mpiexec, which 'numactl' things, in order to make the execution > >>> performance stable. > >>> > >>> Looking on the faq (the oldest one is for OpenMPI v1.3?), I saw that > >>> maybe the > >>> solution would be for me to use the --mca mpi_paffinity_alone 1 > >>> > >>> Is that correct? -- BTW, I have both memory and processor affinity: > >>>> ompi_info | grep affinity > >>> > >>> MCA paffinity: linux (MCA v2.0, API v2.0, Component v1.4.2) > >>> MCA maffinity: first_use (MCA v2.0, API v2.0, Component > >>> v1.4.2) MCA maffinity: libnuma (MCA v2.0, API v2.0, Component v1.4.2) > >>> Does it handle memory too, or do I have to use another option like > >>> --mca mpi_maffinity 1? > >>> > >>> Still, I would like to test the numactl solution. Does OpenMPI provide > >>> an equivalent to $MXMPI_ID which gives at least gives the NODE on which > >>> a process is launched by OpenMPI, so that I can adapt the script that > >>> was given > >>> to me? > >>> > >>> Tkx. > >>> > >>> .Yves. > >>> _______________________________________________ > >>> users mailing list > >>> us...@open-mpi.org > >>> http://www.open-mpi.org/mailman/listinfo.cgi/users > > _______________________________________________ > > users mailing list > > us...@open-mpi.org > > http://www.open-mpi.org/mailman/listinfo.cgi/users
