Le Wednesday 28 July 2010 15:05:28, vous avez écrit : > I am confused. I thought all you wanted to do is report out the binding of > the process - yes? Are you trying to set the affinity bindings yourself? > > If the latter, then your script doesn't do anything that mpirun wouldn't > do, and doesn't do it as well. You would be far better off just adding > --bind-to-core to the mpirun cmd line.
"mpirun -h" says that it is the default, so there is not even something to do? I don't even have to add "--mca mpi_paffinity_alone 1" ? .Yves. > On Jul 28, 2010, at 6:37 AM, Yves Caniou wrote: > > 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-variab > >>>>le 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
