Jeff, I know Intel MPI (MPICH based) "just works" with Phi, but you need to do things like: mpirun –n 2 –host cpu host.exe : –n 4 –host mic0 mic.exe if you want to use the Phi for more than just kernel-offload (in which case they won't have/need an MPI rank). So, launch procs is PART of the problem, but certainty not all of it.
At least, unlike RR, the processing elements all share the same endianness! -Paul On Thu, May 2, 2013 at 6:28 PM, Jeff Squyres (jsquyres) <jsquy...@cisco.com>wrote: > I know the MPICH guys did a bunch of work to support the Phi's. I don't > know exactly what that means (I haven't read their docs about this stuff), > but I suspect that it's more than just launching MPI processes on them... > > > On May 2, 2013, at 8:54 PM, Paul Hargrove <phhargr...@lbl.gov> wrote: > > > Ralph, > > > > I am not an expert, by any means, but based on a presentation I heard 4 > hours ago: > > > > The Xeon and Phi instruction sets have a large intersection, but neither > is a subset of the other. > > In particular, Phi has its own SIMD instructions *instead* of Xeon's > MMX, SSEn, etc. > > There is also on CMPXCHG16B instruction on Phi, among others. > > So, there will need to be different binaries, or "fat" binaries that > branch based on CPU type. > > > > -Paul > > > > > > On Thu, May 2, 2013 at 5:47 PM, Ralph Castain <r...@open-mpi.org> wrote: > > > > On May 2, 2013, at 5:12 PM, Christopher Samuel <sam...@unimelb.edu.au> > wrote: > > > > > -----BEGIN PGP SIGNED MESSAGE----- > > > Hash: SHA1 > > > > > > Hi folks, > > > > > > The new system we're bringing up has 10 nodes with dual Xeon Phi MIC > > > cards, are there any plans to support them by launching MPI tasks > > > directly on the Phis themselves (rather than just as offload devices > > > for code on the hosts)? > > > > We had something similar at one time - I developed it for the Roadrunner > cluster so you could run MPI tasks on the GPUs. Worked well, but eventually > fell into disrepair due to lack of use. > > > > In this case, I suspect it will be much easier to do as the Phis appear > to be a lot more visible to the host than the GPU did on RR. Looking at the > documentation, the Phis just sit directly on the PCIe bus, so they should > look just like any other processor, and they are Xeon binary compatible - > so there is no issue with tracking which binary to run on which processor. > > > > Brice: do the Phis appear in the hwloc topology object? > > > > Chris: can you run lstopo on one of the nodes and send me the output > (off-list)? > > > > > > > > > > All the best, > > > Chris > > > - -- > > > Christopher Samuel Senior Systems Administrator > > > VLSCI - Victorian Life Sciences Computation Initiative > > > Email: sam...@unimelb.edu.au Phone: +61 (0)3 903 55545 > > > http://www.vlsci.org.au/ http://twitter.com/vlsci > > > > > > -----BEGIN PGP SIGNATURE----- > > > Version: GnuPG v1.4.11 (GNU/Linux) > > > Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ > > > > > > iEYEARECAAYFAlGDAPYACgkQO2KABBYQAh+y9ACfZ0SdqDuV7Euq3B0ANtxPhH1D > > > 3h4An1Zlhu2Ut+OFvbTa9xbLBkspwwPY > > > =TbIy > > > -----END PGP SIGNATURE----- > > > _______________________________________________ > > > devel mailing list > > > de...@open-mpi.org > > > http://www.open-mpi.org/mailman/listinfo.cgi/devel > > > > > > _______________________________________________ > > devel mailing list > > de...@open-mpi.org > > http://www.open-mpi.org/mailman/listinfo.cgi/devel > > > > > > > > -- > > Paul H. Hargrove phhargr...@lbl.gov > > Future Technologies Group > > Computer and Data Sciences Department Tel: +1-510-495-2352 > > Lawrence Berkeley National Laboratory Fax: +1-510-486-6900 > > _______________________________________________ > > devel mailing list > > de...@open-mpi.org > > http://www.open-mpi.org/mailman/listinfo.cgi/devel > > > -- > Jeff Squyres > jsquy...@cisco.com > For corporate legal information go to: > http://www.cisco.com/web/about/doing_business/legal/cri/ > > > _______________________________________________ > devel mailing list > de...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/devel > -- Paul H. Hargrove phhargr...@lbl.gov Future Technologies Group Computer and Data Sciences Department Tel: +1-510-495-2352 Lawrence Berkeley National Laboratory Fax: +1-510-486-6900
